Modelling the Vulcanization Reaction of Devulcanized Rubber

The generation of scrap tires/rubber is increasing annually and thus there is a need for a safer and more efficient method of disposal or reuse of this rubber. As the direct disposal (burning/ land filling) of scrap rubber has harmful effects on the environment, recycling and reusing is given great consideration. For reusing, scarp rubber can be devulcanized and used in many applications. Some methods for devulcanization of rubber have been developed and devulcanized rubber can be blended with virgin rubber and re-cured. However, the curing behavior of devulcanized rubber will vary compared to that of virgin rubber so it would be helpful if a proper model could be obtained in order to characterize and optimize the curing properties of devulcanized rubber with respect to the curatives added. The main objective of this study is to characterize the vulcanization reaction of devulcanized rubber by using a kinetic model which will help in predicting the kinetics of vulcanization with change in temperature and the amount of curatives added. Also, it will help to obtain a better understanding of the relationship between curing behavior and properties of devulcanized rubber. It may further help in minimizing the time required for choosing the appropriate cure system for compounds involving devulcanized rubber. This study involves fitting the cure kinetic reaction model on differential scanning calorimetry (DSC) data. Vulcanization is an exothermic process in which the energy released during the reaction is assumed to be proportional to the bonds formed and thus can be related to the degree of vulcanization. DSC records this heat released which is later used to calculate the reaction rate and degree of cure. As vulcanization is a chemical process, its simulation involves characterization of kinetic parameters. Experiments have been done using 7 different samples of devulcanized rubber which vary in curative composition. Those samples have been tested using DSC at different temperature scanning rates and a kinetic model was used to fit the DSC data and to determine the kinetic model parameters. The Kissinger model along with the Arrhenius equation was used to determine the vulcanization activation energy and the Kamal-Sourour model was used to fit the data obtained from DSC through non-linear least square techniques and estimate the rest of the parameters. To have a comparison between virgin rubber and devulcanized rubber, natural rubber samples with similar formulations have been mixed and tested in the same way. Also, to further investigate the cure kinetics of devulcanized rubber, blends of virgin rubber (tire tread compound) with different amounts of devulcanized rubber were analyzed in similar ways

Does Entrepreneur Gender Matter for Entrepreneurial Motivation: Answers from Micro Small and Medium Enterprises (MSMEs) of Assam

With regard to SGD-5, this study attempts to examine the association between entrepreneur’s gender and their entrepreneurial motivation and to discover if entrepreneur’s gender influences the motivation. The study further tries to see if entrepreneurial motivation varies on the grounds of entrepreneur’s gender. Based on a qualitative approach, the study uses interview data of 320 MSME entrepreneurs from Assam, India. Two hypotheses—there is no association between entrepreneur’s gender and the entrepreneurial motivation (H01) and there is no significant difference between the mean rank of male and female entrepreneurs with respect to their motivational factors (H02)—are postulated and tested using Chi-Square and Mann Whitney test respectively. The Chi-Square and Cramer’s V test findings corroborate a strong, positive, and significant association between (H01) entrepreneur’s gender and their entrepreneurial motivations and further the Mann Whitney analysis acknowledged that motivational factors significantly vary across entrepreneur’s gender (H02) refuting the earlier studies. Due to society’s gender perceptions, the relationship between entrepreneurial motivations and entrepreneurship differs between males and females. Men are relatively more drawn towards entrepreneurship than women. Male entrepreneurs are largely the outcome of force (46.9%), create (26.9%), and chance (26.3%) while females are of chance (55.6%), force (30.6%), and create (13.8%) motivational factors. From a policy perspective, female empowering policies should be of two-fold viz., first to economically strengthen them and second to spread awareness about their legal rights

Sustainable development goals and ending ECC as a public health crisis

Early Childhood Caries (ECC) remains a global issue despite numerous advancements in research and interventional approaches. Nearly, 530 million children suffer from untreated dental caries of primary teeth. The consequences of such untreated dental caries not only limit the child's chewing and eating abilities but also, significantly impact the child's overall growth. Research has demonstrated that ECC is associated with nearly 123 risk factors. ECC has also been associated with local pain, infections, abscesses, and sleep pattern. Furthermore, it can affect the child's emotional status and decrease their ability to learn or perform their usual activities. In high-income countries, dental care continues to endorse a “current treatment-based approach” that involves high-technology, interventionist, and specialized approaches. While such approaches provide immediate benefit at an individual level, it fails to intercept the underlying causes of the disease at large. In low-income and middle-income countries (LMICs), the “current treatment approach” often remains limited, unaffordable, and unsuitable for the majority of the population. Rather, dentistry needs to focus on “sustainable goals” and integrate dental care with the mainstream healthcare system and primary care services. Dental care systems should promote “early first dental visits,” when the child is 1 year of age or when the first tooth arrives. The serious shortages of appropriately trained oral healthcare personnel in certain regions of the world, lack of appropriate technologies and isolation of oral health services from the health system, and limited adoption of prevention and oral health promotion can pose as critical barriers. The oral health care systems must focus on three major keystones to combat the burden of ECC−1. Essential oral health services are integrated into healthcare in every country ensuring the availability of appropriate healthcare accessible and available globally, 2. Integrating oral and general healthcare to effectively prevent and manage oral disease and improve oral health, 3. Collaborating with a wide range of health workers to deliver sustainable oral health care tailored to cater to the oral health care needs of local communities

Systematic Review of Clinical Practice Guidelines for Oral Health in Children With Cleft Lip and Palate

OBJECTIVE: Clinical practice guidelines (CPGs) exist to present recommendations and policies aimed at optimizing the oral health of children and adolescents born with cleft lip and/or palate. The aim of this review is to identify and assess the scope, quality, adequacy, and consistency of CPGs related to oral health in children and adolescents with clefts, along with reporting any differences and shortcomings. METHODS: A systematic review of the literature of CPGs following Preferred Reporting Items for Systematic Reviews guidelines was conducted. Assessment of selected CPGs was performed using the Appraisal of Guidelines for Research & Evaluation II methodological quality instrument. RESULTS: Only 7 CPGs fulfilled the criteria. Of these, 4 were from the American Cleft Palate-Craniofacial Association, and 1 each from the American Academy of Pediatrics, the Academy of Breastfeeding Medicine, and the American Academy of Pediatric Dentistry. The lowest overall mean scores were in the domain “Rigor of Development” (mean 29.58%, SD 17.11), revealing lower quality in methodology of the guideline. The domain “Clarity of Presentation” (mean 73.80%, SD 7.87) revealed the best score. CONCLUSIONS: Our review results reveal a lack of integrated high-quality CPGs that can be used as universal guidelines by health workers in a range of disciplines for improving oral health in children and adolescents with cleft problems

Comparative Evaluation of In-vitro Bioefficacy of Microbial Bioagents and Novel Chemical Compounds against Fusarium oxysporum f.sp. Cubense

The Assam and North-eastern regions of India recognized as diverse repositories of wild and cultivated banana cultivars, confront a significant threat to banana varieties, Malbhog due to Fusarium wilt disease caused by Fusarium oxysporum f.sp. cubense (Foc). This study investigates the in-vitro bioefficacy of indigenous bioagents and new-generation chemical compounds against Foc to develop an integrated module subsequently, in line with the worldwide pursuit of environmentally conscientious and high-performance agricultural practices.In this study, four bioagents viz., Bacillus vallismortis, Bacillus amyloliquefaciens, Trichoderma harzianum, and Talaromyces pinophilus were screened in-vitro against Foc revealed the highest efficacy of B. vallismortis with 68.22 % mycelial growth inhibition of Foc followed by B. amyloliquifaciens with (60.05%) and the least inhibition was exhibited by T.pinophilus with (50.05%).To identify new generation chemical compounds, namely Propiconazole, Azoxystrobin, Tebuconazole + Trifloxystrobin were tested with a standard check Carbendazim wherein all the chemicals significantly inhibited the mycelial growth of the pathogen over control with Tebuconazole + Trifloxystrobin combination fungicide showing highest percent inhibition of 94% at 0.1% concentration followed by Carbendazim at 0.1%. Our study has identified potential microbial strains and chemical fungicides which can be further explored for the development and exploration of bio-fungicide and chemical fungicide-based biointensive integrated management of Fusarium wilt menace in malbhog banana in the region

Geographical variation in COVID-19 cases, prevalence, recovery and fatality rate by phase of national Lockdown in India, March 14-May 29, 2020

Background: since the COVID-19 pandemic hit Indian states at varying speed, it is crucial to investigate the geographical pattern in COVID-19. We analyzed the geographical pattern of COVID-19 prevalence and mortality by the phase of national lockdown in India.Method: using publicly available compiled data on COVID-19, we estimated the trends in new cases, period-prevalence rate (PPR), case recovery rate (CRR), and case fatality ratio (CFR) at national, state and district level.Findings: the age and sex are missing for more than 60 percent of the COVID-19 patients. There is an exponential increase in COVID-19 cases both at national and sub-national levels. The COVID-19 infected has jumped about 235 times (from 567 cases in the pre-lockdown period to 1,33,669 in the fourth lockdown); the average daily new cases have increased from 57 in the first lockdown to 6,482 in the fourth lockdown; the average daily recovered persons from 4 to 3,819; the average daily death from 1 to 163. From first to the third lockdown, PPR (0.04 to 5.94), CRR (7.05 to 30.35) and CFR (1.76 to 1.89) have consistently escalated. At state-level, the maximum number of COVID-19 cases is found in the states of Maharashtra, Tamil Nadu, Delhi, and Gujarat contributing 66.75 percent of total cases. Whereas no cases found in some states, Kerela is the only state flattening the COVID-19 curve. The PPR is found to be highest in Delhi, followed by Maharastra. The highest recovery rate is observed in Kerala, till second lockdown; and in Andhra Pradesh in third lockdown. The highest case fatality ratio in the fourth lockdown is observed in Gujarat and Telangana. A few districts viz. like Mumbai (96.7); Chennai (63.66) and Ahmedabad (62.04) have the highest infection rate per 100 thousand population. Spatial analysis shows that clusters in Konkan coast especially in Maharashtra (Palghar, Mumbai, Thane and Pune); southern part from Tamil Nadu (Chennai, Chengalpattu and Thiruvallur), and the northern part of Jammu & Kashmir (Anantnag, Kulgam) are hot-spots for COVID-19 infection while central, northern and north-eastern regions of India are the cold-spots.Conclusion: India has been experiencing a rapid increase of COVID-19 cases since the second lockdown phase. There is huge geographical variation in COVID-19 pandemic with a concentration in some major cities and states while disaggregated data at local levels allows understanding geographical disparity of the pandemic, the lack of age-sex information of the COVID-19 patients forbids to investigate the individual pattern of COVID-19 burden

Evaluation of Genetic Diversity Based on Microsatellites and Phytochemical Markers of Core Collection of Cymbopogon winterianus Jowitt Germplasm

Cymbopogon winterianus Jowitt is an industrially important crop due to its value in the aromatic, perfumery and pharmaceutical industries. In this study, 72 accessions of C. winterianus were selected for molecular diversity analysis using SSR markers. It revealed a total of 65 polymorphic alleles showing an average of 68.10% polymorphism. The best SSR primer with competency in discriminating the germplasm was 3CM0506 with PIC (0.69), MI (0.69) and Rp (3.12). Genetic variation was studied between Assam, Manipur, Meghalaya and Arunachal Pradesh populations. A dendrogram based on the Neighbour-Joining Method showed clustering of germplasm on the collection site. A total of six relevant genetic populations were identified through a structure harvester software analysis. Moreover, a dendrogram based on similarity, complete linkage and Euclidean distance was also elucidated differentiating the genotypes with respect to the major phytochemical constituents of the essential oil. GC-FID and GC-MS analyses of the essential oil of the 72 germplasms revealed citronellal content from 2.58–51.45%, citronellol from 0.00–26.39% and geraniol from 0.00–41.15%. This is the first molecular diversity report with 72 accessions of C. winterianus collected from the NE region using 28 SSR primers as well as their diversity based on phytochemical markers. This diversity computation will help with acquisition of the knowledge and relationship among each individual accession leading to the development of improved and essential oil component-rich cultivars

Anti-endothelial cell antibody rich sera from rheumatic heart disease patients induces proinflammatory phenotype and methylation alteration in endothelial cells

Rheumatic heart disease (RHD) is a major cause of cardiovascular morbidity and mortality in developing nations like India. RHD commonly affects the mitral valve which is lined by a single layer of endothelial cells (ECs). The role of ECs in mitral valve damage during RHD is not well elucidated. In here, anti-endothelial cell antibody from RHD patients has been used to stimulate the ECs (HUVECs and HMVECs). ECs proinflammatory phenotype with increased expression of TNFα, IL-6, IL-8, IFNγ, IL-1β, ICAM1, VCAM1, E-selectin, laminin B, and vimentin was documented in both ECs. The promoter hypomethylation of various key inflammatory cytokines (TNFα, IL-6, and IL-8), integrin (ICAM1) associated with leukocyte transendothelial migration, and extracellular matrix genes (vimentin, and laminin) were also observed. Further, the in-vitro data was in accordance with ex-vivo observations which correlated significantly with the etiological factors such as smoking, socioeconomic status, and housing. Thus, the study sheds light on the role of ECs in RHD which is a step forward in the elucidation of disease pathogenesis. Keywords: Anti-Endothelial cell antibodies, DNA methylation, Endothelial cells, Inflammation, Rheumatic heart diseas

Performance analysis of dual stator six‐phase embedded‐pole permanent magnet synchronous motor for electric vehicle application

Abstract The motive of this study is to analyse the characteristics of a novel dual‐stator embedded‐pole six‐phase permanent magnet synchronous motor for the application of electric vehicles. A comparative analysis of two separate motor topologies, namely, dual stator embedded‐pole six‐phase permanent magnet synchronous motor and single stator single rotor surface‐mounted permanent magnet synchronous motor, is accomplished to illustrate the performance superiority of the proposed motor. Furthermore, for optimal designing of the proposed motor, a design methodology has also been presented. For the above application, the motor should retain high torque density (HTD) and high reliability. In this regard, a novel H‐Shaped flux barrier is introduced in the rotor portion, which fulfils the requirement of HTD. Moreover, the availability of two sets of the stator winding enhances the performance efficiency and ensures the proposed motor's more significant fault‐tolerating ability of the motor. For performance evaluation, the Finite Element Method analysis is chosen, as it gives appropriate and precise results. From the above analysis, it is concluded that the HTD and the proposed motor's dynamic performance are better than the above‐mentioned conventional motor