Study on dielectric properties of gel polymer electrolyte based on PVA-K2CO3 composites

The advance of gel polymer electrolyte (GPEs) based on conducting salt-polymer has been a subject of concern recently due to their significant applications. This work presents a study of dielectric properties of GPE based on polyvinyl alcohol (PVA) and potassium carbonate (K2CO3) (PVA-K2CO3) electrolyte for electrochemical applications. The electrolyte material was synthesized by mixing a conducting salt (K2CO3) with PVA in different proportions (from 10 - 50 wt. %) in order to study the effect of the salt on the dielectric properties of the electrolyte. The synthesized GPE was characterized using X-ray powder diffraction (XRD) to study electrolyte's crystal phase. Both complex permittivity and complex modulus formalism (dielectric behaviour) of the electrolyte were analysed through electrochemical impedance spectroscopy (EIS). The characterization result shows that the peak intensity of the PVA is significantly reduced with the increase of K2CO3 wt.%. which could be attributed to the decrease of PVA crystallinity which can enlarge the amorphous region of the polymer due to the strong plasticizing effect of the salt. High values of complex permittivity (dielectric constant and dielectric loss) were observed at low frequencies, which increased with increasing temperature, indicating an increase in conductivity. From the real part of electric modulus, the material is featured to be highly capacitive. Based on the asymmetrical peak shape of the imaginary part of electric modulus, the non-Debye type relaxation is predicted. Straight-line graphs were observed from the frequency dependency of loss tangent (tan 6), showing no single relaxation process is present

Unveiling the effects of nickel loading on methane dry reforming: Perspectives from Ni/fibrous Zeolite-Y catalysts

The development of new technologies that employ greenhouse gases, such as CO2 and CH4, is becoming more important in the fight against global warming. Catalytic methane dry reforming (MDR) is one straightforward way to reduce CO2 and CH4. In this study, the influence of nickel (Ni) loading on the catalytic performance of fibrous zeolite-Y catalysts (Ni/FHY) for MDR was explored. The study involved the synthesis and testing of Ni/FHY with varying Ni loadings (1 wt% to 10 wt%). The results demonstrate that the metal loading significantly affects the catalysts' performance through metal-support interaction. The catalytic activity showed that the performance of FHY increased with optimum metal loading of 5 wt% where the CO2 conversion increased to 90.3% from 82.2%, and CH4 conversion to 94.2% from 79.6%. The findings suggest that the 5 wt% optimal Ni loading showed the critical role of the metal-support interaction in shaping catalytic properties. Hence, this work provides insights into catalyst optimization for sustainable industrial processes, highlights the importance of the synergistic metal-support interaction, and provides insights into the relationship between Ni content and catalytic behavior. Thus, it offers a basis for optimizing catalysts in MDR and contributes to the advancement of sustainable industrial processes

A concise review on surface and structural modification of porous zeolite scaffold for enhanced hydrogen storage

Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical properties. Nevertheless, the storage capacity of the unmodified zeolites has been rather unsatisfactory (0.224%–1.082% (mass)) compared to its modified counterpart. Thus, the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites, with studies exploring surface modifications through physical and chemical treatments, as well as the integration of various active metals. The enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals, resulting in increased storage capacity through interactions with the charge density of these aluminosilicates. Therefore, there is a great demand to critically review their role such as well-defined topology, pore structure, good thermal stability, and tunable hydrophilicity in enhanced hydrogen storage. This article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen storage. Some of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent, like pressure, structure, and morphology were studied, and examined. Then, future perspectives, recommendations, and directions for modified zeolites were discussed

Dependence of the optical constant parameters of p-toluene sulfonic acid-doped polyaniline and its composites on dispersion solvents

The optical constants of Para-Toluene sulfonic acid-doped polyaniline (PANI), PANIchitosan composites, PANI-reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide dispersed in diluted p-toluene sulfonic acid (PTSA) solution and N-Methyl-2-Pyrrolidone (NMP) solvent have been evaluated and compared. The optical constant values were extracted from the absorbance spectra of thin layers of the respective samples. The potential utilization of the materials as the active sensing materials of surface plasmon resonance biosensors has also been assessed in terms of the estimated value of the penetration depth through a dielectric medium. The results show a reasonable dependence of the optical constant parameters on the solvent type. Higher real part refractive index (n) and real part complex dielectric permittivity (ε’) values were observed for the samples prepared using PTSA solution, while higher optical conductivity values were observed for the NMP-based samples due to their relatively higher imaginary part refractive index (k) and imaginary part complex dielectric permittivity (ε″) values. In addition, NMP-based samples show improvement in terms of the penetration depth through a dielectric medium by around 9.5, 1.6, 4.4 and 2.9 times compared to PTSA-based samples for the PANI, PANI-chitosan, PANI-RGO and the ternary composites, respectively. Based on these, it is concluded that preparation of these materials using different dispersion solvents could produce materials of different optical properties. Thus, the variation of the dispersion solvent will allow the flexible utilization of the PANI and the composites for diverse applications

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

BIODIESEL PRODUCTION FROM RUBBER SEEDS {Hevea Brasiliensis) BY IN-SITU TRANSESTERIFICATION METHOD

Biodiesel is mono-alkyl esters ofvegetable oils (both edible and non-edible) oranimal fats. There are two basic methods in which biodiesel can be produced. Firstly, by means of transesterifying oil or fat with an alcohol assisted with an acid or alkali catalyst. Secondly, it can be produced through in-situ transesterification method where the raw material (seeds) can be made to react directly with an alcohol in the present of catalyst. The environmentally friendly nature of biodiesel has made it an attractive alternative that can beused as a renewable fuel in the existing engines. The main objective for this thesis is the production of biodiesel by in-situ transesterification (direct transesterification) method from the seed of rubber tree using KOH as a catalyst. The influence of reaction time, seed sizes, reaction temperature, seed to methanol mass ratio, and seed to catalyst mass ratio on the FAME yield was investigated

OPTIMIZATION OF ELECTROSPUN POLYMER ELECTROLYTE BASED ON PVA-K2CO3-SIO2-CELLULOSE COMPOSITE FOR IMPROVED ELECTROCHEMICAL PROPERTIES

Recent development in portable electronics has promoted a growing demand for high performing energy storage systems. One of the most important component that provide charge carriers in any energy storage devices is electrolyte. The electrolyte is very vital providing ionic conductivity and permitting charge on electrodes within the system. Among the electrolytes explored, gel polymer electrolytes (GPE) are essential due to their safety record. However, low ionic conductivity and potential window are the main obstacle restricting their daily application. In this study, an un plasticized and plasticized GPE materials based on polyvinyl alcohol (PVA), salt (K2CO3) and plasticizer (SiO2) with improved ionic conductivity and potential window were explored. The optimum electrochemical performance was exhibited by plasticized GPE sample with 15 wt.% SiO2 (PKS15), having optimum ionic conductivity of 3.25 × 10–4 and 7.86 × 103 mScm1 at ambient temperature and at 373.15 K, respectively, and potential window of 3.35 V

MEDIATION ROLE OF SOCIAL MEDIA ADOPTION ON THE ORGANIZATIONAL INNOVATIVENESS AND SMEs PERFORMANCE IN NORTH-WESTERN NIGERIA

The study seeks to examine the relationship between organizational innovativeness and SME performance and the mediating effect of social media adoption.  Statistical analyses were based on the data collected, through a survey questionnaire from 396 SMEs in North western Nigeria. The Partial Least Square (PLS) method was used to investigate the relationship between the study variables. The study found that the direct impact of organizational innovativeness is not significantly correlated with SME performance, social media is significant in mediating the relationship between organizational innovativeness and the SME's performance and context-specific nature necessitates tailoring strategies based on industry-specific conditions, market characteristics, and technological landscapes. The study concluded that organizational innovativeness exhibited relatively modest effects on SME performance, and social media adoption as a mediator unveiled a statistically significant relationship, highlighting the pivotal role of social media in influencing SME performance within the context of organizational innovation. Finally, the study recommends that SMEs should emphasize the incorporation of social media platforms as integral components of innovation strategies within SMEs, consider holistic approaches that incorporate diverse elements such as social media adoption to enhance the effectiveness of innovation strategies and encourage SMEs to invest in technological adoption beyond traditional innovation practices

Effect of different aqueous extracts of garlic on some electrolytes and urea levels in rats

Studies on the effect of fresh and dried aqueous extracts of garlic (cold and hot) on Na+, K+, Cl-, HCO3- and urea levels of rats were carried-out. Animals were divided into 5 groups of 5 rats each. Groups I and II were treated with fresh cold and hot extract respectively, while groups III and IV received dried cold and hot extract respectively. Group V served as untreated control. Treatment was by oral administration at 100mg/kg body weight for seven consecutive days. Analysis of the results showed significant (P 0.05). The extracts appeared to have no effect on urea level when compared with the control group. The decrease observed in these electrolytes monitored were more with fresh cold extract than with others. The results therefore suggest that fresh cold garlic extract may be useful in the management of electrolyte related disorders. Key words: Garlic; Electrolytes; Urea Journal of Pharmacy and Bioresources Vol. 2 (1) 2004: 1-