Comprehensive Study of Zr-Doped Ni-Rich Cathode Materials Upon Lithiation and Co-Precipitation Synthesis Steps.

Ni-rich layered oxides LiNi1-x-yMnxCoyO2 (NMC811, x = 0.1 and y = 0.1) are considered promising cathode materials in lithium-ion batteries (LiBs) due to their high energy density. However, those suffer a severe capacity loss upon cycling at high delithiated states. The loss of performance over time can be retarded by Zr doping. Herein, a small amount of Zr is added to NMC811 material via two alternative pathways: during the formation of the transition metal (TM) hydroxide precursor at the co-precipitation step (0.1%-Zr-cp) and during the lithiation at the solid-state synthesis step (0.1%-Zr-ss). In this work, the crystallographic Zr uptake in both 0.1%-Zr-ss and 0.1%-Zr-cp is determined and quantified through synchrotron X-ray diffraction and X-ray absorption spectroscopy. We prove that the inclusion of Zr in the TM site for 0.1%-Zr-cp leads to an improvement of both specific capacity (156 vs 149 mAh/g) and capacity retention (85 vs 82%) upon 100 cycles compared to 0.1%-Zr-ss where the Zr does not diffuse into the active material and forms only an extra phase separated from the NMC811 particles.

Optical and thermoelectric properties of new Janus ZnMN2 (M = Ge, Sn, Si and N = S, Se, Te) monolayers: a first-principles study.

Thermoelectric materials have received great interest because they directly tap into the vast reserves of currently underused thermal energy, in an environmentally friendly manner. In this work, we investigated the electronic, optical and thermoelectric properties of novel ZnMN2 (M = Ge, Sn, Si and N = S, Se, Te) monolayers by performing density functional theory calculations. The dynamic and thermal stabilities of ZnMN2 (M = Ge, Sn, Si and N = S, Se, Te) monolayers were confirmed by their phonon band structures and ab initio molecular dynamics (AIMD) simulations, which showed that all the studied monolayers are stable. Calculated electronic band structures showed that ZnSiTe2, ZnGeSe2, and ZnSnTe2 have a direct band gap, while the remaining monolayers have an indirect band gap. Optical properties in terms of the imaginary part of the dielectric function have also been investigated, which showed that all the first excitonic peaks lie in the visible region. Transport coefficients, such as the Seebeck coefficient (S), electrical conductivity (σ) and power factor (PF) were calculated using the Boltzmann theory and plotted against chemical potential. The results demonstrated that the peak values of the p-type region for the PF are greater than those of the n-type region. Notably, ZnSiTe2 exhibits a large PF due to its smaller Seebeck coefficient and higher electrical conductivity compared to ZnSnS2, indicating that it is a promising candidate for thermoelectric applications. Our findings reveal that ZnMN2 (M = Ge, Sn, Si and N = S, Se, Te) monolayers open up new possibilities for optoelectronics and thermoelectric device applications.

Scalable Precursor-Assisted Synthesis of a High Voltage LiNiyCo1-yPO4 Cathode for Li-Ion Batteries.

A solid-solution cathode of LiCoPO4-LiNiPO4 was investigated as a potential candidate for use with the Li4Ti5O12 (LTO) anode in Li-ion batteries. A pre-synthesized nickel-cobalt hydroxide precursor is mixed with lithium and phosphate sources by wet ball milling, which results in the final product, LiNiyCo1-yPO4 (LNCP) by subsequent heat treatment. Crystal structure and morphology of the product were analyzed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Its XRD patterns show that LNCP is primarily a single-phase compound and has olivine-type XRD patterns similar to its parent compounds, LiCoPO4 and LiNiPO4. Synchrotron X-ray absorption spectroscopy (XAS) analysis, however, indicates that Ni doping in LiCoPO4 is unfavorable because Ni2+ is not actively involved in the electrochemical reaction. Consequently, it reduces the charge storage capability of the LNCP cathode. Additionally, ex situ XRD analysis of cycled electrodes confirms the formation of the electrochemically inactive rock salt-type NiO phase. The discharge capacity of the LNCP cathode is entirely associated with the Co3+/Co2+ redox couple. The electrochemical evaluation demonstrated that the LNCP cathode paired with the LTO anode produced a 3.12 V battery with an energy density of 184 Wh kg-1 based on the cathode mass.

Oxygen Reduction Reaction Activity in Non-Precious Single-Atom (M-N/C) Catalysts-Contribution of Metal and Carbon/Nitrogen Framework-Based Sites.

We examine the performance of a number of single-atom M-N/C electrocatalysts with a common structure in order to deconvolute the activity of the framework N/C support from the metal M-N4 sites in M-N/Cs. The formation of the N/C framework with coordinating nitrogen sites is performed using zinc as a templating agent. After the formation of the electrically conducting carbon-nitrogen metal-coordinating network, we (trans)metalate with different metals producing a range of different catalysts (Fe-N/C, Co-N/C, Ni-N/C, Sn-N/C, Sb-N/C, and Bi-N/C) without the formation of any metal particles. In these materials, the structure of the carbon/nitrogen framework remains unchanged-only the coordinated metal is substituted. We assess the performance of the subsequent catalysts in acid, near-neutral, and alkaline environments toward the oxygen reduction reaction (ORR) and ascribe and quantify the performance to a combination of metal site activity and activity of the carbon/nitrogen framework. The ORR activity of the carbon/nitrogen framework is about 1000-fold higher in alkaline than it is in acid, suggesting a change in mechanism. At 0.80 VRHE, only Fe and Co contribute ORR activity significantly beyond that provided by the carbon/nitrogen framework at all pH values studied. In acid and near-neutral pH values (pH 0.3 and 5.2, respectively), Fe shows a 30-fold improvement and Co shows a 5-fold improvement, whereas in alkaline pH (pH 13), both Fe and Co show a 7-fold improvement beyond the baseline framework activity. The site density of the single metal atom sites is estimated using the nitrite adsorption and stripping method. This method allows us to deconvolute the framework sites and metal-based active sites. The framework site density of catalysts is estimated as 7.8 × 1018 sites g-1. The metal M-N4 site densities in Fe-N/C and Co-N/C are 9.4 × 1018 sites-1 and 4.8 × 1018 sites g-1, respectively.

The Relationship between Energy Consumption, CO2 Emissions, Economic Growth, and Health Indicators.

The health and wellness of people through life expectancy, mortality rate improvement, and sustaining the productivity of labor contributes a lot to national income. Infrastructure development consumes energy and releases carbon dioxide at different stages of the construction process. The current study explores the nexus between CO2 emission, energy consumption, mortality, life expectancy, and GDP in the top five carbon-emitting countries by using time series data from 1975 to 2015. The study used a cointegration technique to find the long- and short-run relationships between study variables. The study also used a structural break test to identify the break time. The results of the correlation matrix show strong positive correlation between CO2 emissions and energy consumption. It also reflects a weak correlation with mortality and life expectancy in Japan and Russia. The results of the ADF test indicated that the series are stationary at first difference and provided evidence to use Johansen cointegration test for long- and short-run relationships between independent series. Vector error correction term and ECT method are used to find long-run relationships between cointegrated series and adjustment parameters. For the structural breaks of health indicators and energy consumption study, we used the Gregory Hanson structural break. Mortality rate and life expectancy rate of China, U.S., Russia, India, and Japan show relevant policy changes with economic policies of each country.

MoO3@MoS2 Core-Shell Structured Hybrid Anode Materials for Lithium-Ion Batteries.

We explore a phase engineering strategy to improve the electrochemical performance of transition metal sulfides (TMSs) in anode materials for lithium-ion batteries (LIBs). A one-pot hydrothermal approach has been employed to synthesize MoS2 nanostructures. MoS2 and MoO3 phases can be readily controlled by straightforward calcination in the (200-300) °C temperature range. An optimized temperature of 250 °C yields a phase-engineered MoO3@MoS2 hybrid, while 200 and 300 °C produce single MoS2 and MoO3 phases. When tested in LIBs anode, the optimized MoO3@MoS2 hybrid outperforms the pristine MoS2 and MoO3 counterparts. With above 99% Coulombic efficiency (CE), the hybrid anode retains its capacity of 564 mAh g-1 after 100 cycles, and maintains a capacity of 278 mAh g-1 at 700 mA g-1 current density. These favorable characteristics are attributed to the formation of MoO3 passivation surface layer on MoS2 and reactive interfaces between the two phases, which facilitate the Li-ion insertion/extraction, successively improving MoO3@MoS2 anode performance.

Efficacy of Probiotics in Management of Celiac Disease.

Objective The objective of this study was to interpret any rule of probiotics in the management of celiac disease and apply the results to improve the quality of life of patients with celiac disease if the result comes in favor of probiotics. Materials and methods It was a cross-sectional study conducted in the gastroenterology unit of Nishtar Medical University, Multan. A total of 170 children with celiac disease were enrolled in the study and divided into two groups (A and B) using a computer-generated table of random numbers. Group A was given only a gluten-free diet, while group B was given probiotics and a gluten-free diet. The efficacy of probiotics was measured in terms of reduction in stool frequency at the end of the 28 days of treatment. The data was recorded on the datasheet for every individual, and the statical analysis was performed using the Chi-square test. The patients were fully explained about the research purpose, and written consent was taken from them. Results The efficacy of probiotics in children with celiac disease was compared in both groups. Results showed a marked reduction in the frequency of stools to less than half, i.e., 90.59% (n=77) in group B and 63.53% (n=54) in group A. The Chi-Square test resulted in a p-value of 0.000027 showing a significant difference in both groups. Conclusion Probiotics are found to be highly efficient in terms of reduction in diarrhea in celiac disease. Probiotics will improve not only quality of life but also play an essential role in managing celiac disease.

New O3-Type Layer-Structured Na0.80[Fe0.40Co0.40Ti0.20]O2 Cathode Material for Rechargeable Sodium-Ion Batteries.

Herein, we formulated a new O3-type layered Na0.80[Fe0.40Co0.40Ti0.20]O2 (NFCTO) cathode material for sodium-ion batteries (SIBs) using a double-substitution concept of Co in the parent NaFe0.5Co0.5O2, having the general formula Na1-x[Fe0.5-x/2Co0.5-x/2M4+x]O2 (M4+ = tetravalent ions). The NFCTO electrode delivers a first discharge capacity of 108 mAhg-1 with 80% discharge capacity retention after 50 cycles. Notably, the first charge-discharge profile shows asymmetric yet reversible redox reactions. Such asymmetric redox reactions and electrochemical properties of the NFCTO electrode were correlated with the phase transition behavior and charge compensation reaction using synchrotron-based in situ XRD and ex situ X-ray absorption spectroscopy. This study provides an exciting opportunity to explore the interplay between the rich chemistry of Na1-x[Fe0.5-x/2Co0.5-x/2M4+x]O2 and sodium storage properties, which may lead to the development of new cathode materials for SIBs.

Development of a highly active FeNC catalyst with the preferential formation of atomic iron sites for oxygen reduction in alkaline and acidic electrolytes.

Nitrogen-doped porous carbons containing atomically dispersed iron are prime candidates for substituting platinum-based catalysts for oxygen reduction reaction (ORR) in fuel cells. These carbon catalysts are classically synthesizedviacomplicated routes involving multiple heat-treatment steps to form the desired Fe-Nx sites. We herein developed a highly active FeNC catalyst comprising of exclusive Fe-Nx sites by a simplified solid-state synthesis protocol involving only a single heat-treatment. Imidazole is pyrolyzed in the presence of an inorganic salt-melt resulting in highly porous carbon sheets decorated with abundant Fe-Nx centers, which yielded a high density of electrochemically accessible active sites (1.36 × 1019 sites g-1) as determined by the in situ nitrite stripping technique. The optimized catalyst delivered a remarkable ORR activity with a half-wave potential (E1/2) of 0.905 VRHE in alkaline electrolyte surpassing the benchmark Pt catalyst by 55 mV. In acidic electrolyte, an E1/2 of 0.760 VRHE is achieved at a low loading level (0.29 mg cm-2). In PEMFC tests, a current density of 2.3 mA cm-2 is achieved at 0.90 ViR-free under H2-O2 conditions, reflecting high kinetic activity of the optimized catalyst.

Mixed convection stagnation point flow of the blood based hybrid nanofluid around a rotating sphere.

In this new world of fluid technologies, hybrid nanofluid has become a productive subject of research among scientists for its potential thermal features and abilities, which provides an excellent result as compared to nanofluids in growing the rate of heat transport. Our purpose here is to introduce the substantial influences of magnetic field on 2D, time-dependent and stagnation point inviscid flow of couple stress hybrid nanofluid around a rotating sphere with base fluid is pure blood, [Formula: see text] as the nanoparticles. To translate the governing system of partial differential equations and the boundary conditions relevant for computation, some suitable transformations are implemented. To obtain the analytical estimations for the corresponding system of differential expression, the innovative Optimal Homotopy Analysis Method is used. The characteristics of hybrid nanofluid flow patterns, including temperature, velocity and concentration profiles are simulated and analyzed in detail due to the variation in the evolving variables. Detailed research is also performed to investigate the influences of relevant constraints on the rates, momentum and heat transport for both [Formula: see text] and [Formula: see text]. One of the many outcomes of this analysis, it is observed that increasing the magnetic factor will decelerate the hybrid nanofluid flow velocity and improve the temperature profile. It may also be demonstrated that by increasing the Brownian motion factor, significant improvement can be made in the concentration field of hybrid nanofluid. The increase in the nanoparticle volume fraction from 0.01 to 0.02 in the case of the hybrid nanofluid enhances the thermal conductivity from 5.8 to 11.947% and for the same value of the nanoparticle volume fraction in the case of nanofluid enhance the thermal conductivity from 2.576 to 5.197%.

Ornamental plants for the phytoremediation of heavy metals: Present knowledge and future perspectives.

Environmental matrices are polluted with the plethora of contaminants, and among these, the concerns related to heavy metals (HMs) are also included. Due to the low cost in a long-term application and environmental friendliness, the use of biological remediation has gained significant attention in recent decades. The use of ornamental plants (OPs) in the field of phytoremediation is scarcely reported, and the impacts of HMs on OPs have also not been investigated in great depth. The OPs mediated HMs remediation can simultaneously remove contaminants and bring improvement in aesthetics of the site. The biomass of OPs produced after such activities can be used and sold as pot plants, cut flowers, essential oils, perfumes, air fresheners production, metal phytomining, and feedstock in silk production. The OPs also present a lower risk of HMs bioaccumulation compared to crop plants. This review focuses on the current knowledge of HMs toxicity to OPs, their applicability advantages, methods to improve the tolerance of OPs with incremented HMs uptake, challenges in the field, and future application perspectives. The case studies realted to practical application of OPs, from China, Iran, India, Oman, Pakistan, and Turkey, were also discussed. This work fetches the inter-disciplinary features and understanding for the sustainable treatment of HMs in a new novel way, to which no previous review has focused.

Relationship between knowledge on COVID-19 and psychological distress among students living in quarantine: an email survey.

Psychological distress is a generic term which refers to "feeling of emotional strain" that affects our normal mental and physical functioning. The aim of this study is to investigate the psychological distress perceived by the Pakistani students living in quarantine and to determine risk and protective factors, including knowledge of COVD-19, among this population. It is a descriptive cross-sectional study conducted from February to May 2020. Students enrolled at different colleges and universities of Pakistan participated in this survey. One-way analysis of variance (ANOVA) is computed for comparing knowledge scores of participants having different levels of psychological distress. A total of 937 participants completed the survey questionnaire, with slightly more male respondents (60.6%) than female (39.4%). The average age of survey participants is 22.0 years (SD = 3.01), with majority (76.2%) belonging to urban areas. The mean COVID-19 knowledge score is 8.91 (SD = 1.69, range: 1-12), suggesting an overall 74.25% precision rate for this knowledge test for individual participant. The participants scored least knowledge regarding the disease transmission, showing a percentage correctness of only 40%. Majority of the participants (57.3%) are likely to be well, while others (42.7%) have shown symptoms of mental distress. The analysis reveals that participants with moderate mental distress (M = 8.81, SD = 2.37) and those with severe mental distress (M = 8.75, SD = 2.69) scored lower than participants who were likely to be well (M = 9.49, SD = 1.71). Our study concludes that a higher knowledge base regarding the disease will help to mitigate distress levels. Our study suggests that in order to deal with this pandemic effectively, the knowledge regarding COVID-19 should be properly conveyed to general public. It is need of the hour to address mental issues of the population aggressively along with providing awareness about COVID-19.

Does the prevailing Indian agricultural ecosystem cause carbon dioxide emission? A consent towards risk reduction.

Recently, due to the increasing concentration of carbon dioxide emissions in the atmosphere, the global environment has changed dramatically. As a result, climate change, global warming, and environmental degradation-like issues have been raised. Presumably, human beings, as well as the agricultural ecosystem, become most vulnerable to these issues. In this context, the study focuses on the nexus between Indian's agricultural ecosystem and carbon dioxide emission. For the purpose of this study, annual time series data over the time span from 1990 to 2014 was used. The modern techniques, for instance, Johansen, ARDL, and Granger causality, were employed. The Johansen test and ARDL model suggest that carbon dioxide emissions and agricultural ecosystems are co-integrated. In the short run, the ARDL model suggests that a 1% increase in biomass-burned crop residues, total pesticides, and stock of livestock would increase carbon dioxide emissions by 0.26, 0.3, and 6.58% respectively. The residual diagnostics tests suggest that the ARDL model is stable, reliable, and credible in the present form. The results of the granger causality show that a unidirectional causality was found between carbon dioxide and total heads of livestock, all animal manure applied to the soil, agricultural technology, and total pesticide used in the agricultural sector. In contrast, bidirectional causality was found between the production of biomass-burned crop residues and carbon dioxide emission. Therefore, it is suggested that the government should take preemptive action to reduce the risk of environmental pollution and degradation through synchronized strategies particularly by reducing the amount of biomass-burned crop residues and usage of total pesticides in the country.

Improving Lithium-Ion Half-/Full-Cell Performance of WO3 -Protected SnO2 Core-Shell Nanoarchitectures.

Anodes derived from SnO2 offer a greater specific capacity comparative to graphitic carbon in lithium-ion batteries (LIBs); hence, it is imperative to find a simple but effective approach for the fabrication of SnO2 . The intelligent surfacing of transition metal oxides is one of the favorite strategies to dramatically boost cycling efficiency, and currently most work is primarily aimed at coating and/or compositing with carbon-based materials. Such coating materials, however, face major challenges, including tedious processing and low capacity. This study successfully reports a new and simple WO3 coating to produce a core-shell structure on the surface of SnO2 . The empty space permitted natural expansion for the SnO2 nanostructures, retaining a higher specific capacity for over 100 cycles that did not appear in the pristine SnO2 without WO3 shell. Using WO3 -protected SnO2 nanoparticles as anode, a coin half-cell battery was designed with Li-foil as counter-electrode. Furthermore, the anode was paired with commercial LiFePO4 as cathode for a coin-type full cell and tested for lithium storage performance. The WO3 shell proved to be an effective and strong enhancer for both current rate and specific capacity of SnO2 nanoarchitectures; additionally, an enhancement of cyclic stability was achieved. The findings demonstrate that the WO3 can be used for the improvement of cyclic characteristics of other metal oxide materials as a new coating material.

Manure storage operations mitigate nutrient losses and their products can sustain soil fertility and enhance wheat productivity.

Livestock manure is a valuable source of nutrients for plants. However, poor handling practices during storage resulted in nutrient losses from the manure and decrement in its nitrogen (N) fertilizer value. We explored the influence of divergent storage methods on manure chemical composition, carbon (C) and N losses to the environment as well as fertilizer value of storage products after their application to the wheat. Fresh buffalo manure (FM) was subjected to different storage operations for a period of ∼6 months, (i) fermentation by covering with a plastic sheet (CM) (ii) placed under the roof (RM) (iii) heap was unturned (SM) to remain stacked at an open space and (iv) manure heap turned monthly (TM) to make compost. During storage, 8, 24, 45 and 46% of the initial Ntotal was lost from CM, RM, SM, and TM, respectively. The respective C losses from these treatments were 16, 34, 47 and 44% of the initial C content. After stored manures application to the wheat crop, mineral N in the soil remained 27% higher in CM (14.1 vs. 11.1 kg ha-1) and 3% (10.8 vs. 11.1 kg ha-1) lower in SM compared to FM treatment. In contrast, microbial biomass C and N was 35 (509 vs.782 mg C kg-1 soil) and 25% (278 vs.370 mg N kg-1 soil) lower in CM than FM treatment, respectively indicating lower N immobilization of CM in the soil. These findings could result in the highest grain yield (5166 kg ha-1) and N uptake (117 kg ha-1) in CM and the lowest in SM treatments (3105 and 61 kg ha-1, respectively). Similarly, wheat crop recovered 44, 15 and 13% N from CM, TM and SM, respectively. Hence, management operations play a critical role in conserving N during storage phase and after stored manure application to the field. Among the studied operations, storing animal manure under an impermeable plastic sheet is a much better and cheaper option for decreasing N losses during storage and improving wheat yield when incorporated into the soil. Therefore, by adopting this manure storage technique, farmers can improve the agro-environmental value of animal manure in Pakistan.

Pilot scale intensification of rubber seed (Hevea brasiliensis) oil via chemical interesterification using hydrodynamic cavitation technology.

Chemical interesterification of rubber seed oil has been investigated for four different designed orifice devices in a pilot scale hydrodynamic cavitation (HC) system. Upstream pressure within 1-3.5bar induced cavities to intensify the process. An optimal orifice plate geometry was considered as plate with 1mm dia hole having 21 holes at 3bar inlet pressure. The optimisation results of interesterification were revealed by response surface methodology; methyl acetate to oil molar ratio of 14:1, catalyst amount of 0.75wt.% and reaction time of 20min at 50°C. HC is compared to mechanical stirring (MS) at optimised values. The reaction rate constant and the frequency factor of HC were 3.4-fold shorter and 3.2-fold higher than MS. The interesterified product was characterised by following EN 14214 and ASTM D 6751 international standards.