The Role of Δ(1232)\Delta(1232) in Two-pion Exchange Three-nucleon Potential

In this paper we have studied the two-pion exchange three-nucleon potential $(2\pi E-3NP)$ using an approximate $SU(2) \times SU(2)$ chiral symmetry of the strong interaction. The off-shell pion-nucleon scattering amplitudes obtained from the Weinberg Lagangian are supplemented with contributions from the well-known $\sigma$-term and the $\Delta(1232)$ exchange. It is the role of the $\Delta$-resonance in $2\pi E-3NP$, which we have investigated in detail in the framework of the Lagrangian field theory. The $\Delta$-contribution is quite appreciable and, more significantly, it is dependent on a parameter Z which is arbitrary but has the empirical bounds $|Z| \leq 1/2$. We find that the $\Delta$-contribution to the important parameters of the $2\pi E-3NP$ depends on the choice of a value for Z, although the correction to the binding energy of triton is not expected to be very sensitive to the variation of Z within its bounds.Comment: 14 pages, LaTe

Psychosocial Consequences of Intensive Internet Use among Undergraduates of Universities in Ilorin Metropolis

This study was carried out to investigate the psychosocial consequences of intensive internet use among undergraduate of universities in Ilorin metropolis, Kwara State. This study sought to determine the psychosocial consequences of intensive internet use on the basis on gender, age, level of study and marital status (University of Ilorin and AL-HIKMAH University) universities within Ilorin metropolis. A self-developed questionnaire tagged questionnaire on psychosocial consequences of intensive internet use (PCIIU) was used to collect data from the respondents for the study. Five research hypotheses were formulated and tested at 0.05 alpha level of significance, data collected were analyzed through analysis of variance (ANOVA). The study revealed that psychosocial consequences of intensive internet use are establishing using new relationship with fellow online users; incur more financial cost on internet; spending more time online than going out with others and there was significant gender difference in the psychosocial consequences of intensive internet use among undergraduate students of universities in Ilorin metropolis base on age, level, gender and marital status. Therefore, the following recommendations were made that counsellors should develop strategies to handle internet addiction among the youth and counsellor should encourage the formation of club that will promote safe and responsible internet use among students (peer counselling) and school administrators, teachers and school counsellors should work collaboratively to identify and assist students with or prone to internet addiction before it will have devastating consequences on the addicts and the society at large

Distribution of soil fractions and location of soil bacteria in a vertisol under cultivation and perennial grass

Effects of soil management on soil characteristics were investigated on the rhizosphere (RPP) and the non-rhizosphere (NRPP) siol of a re-grass vertisol under #Digitaria decumbens and in the soil under continuous cultivation (CC). A low energy technique allowed to separate eight size and density fractions, including macro- and micro-aggregates while preserving soil bacteria. Organic C and N, microbial biomass C and the number of total bacteria (AODC) and of #Azospirillum brasilense and their distribution were determined in soil fractions isolated from the CC, NRPP and RPP soils. Soil macroaggregates (>2000 micrometers) were similarly predomminant in the NRPP and RPP soils when the dispersible clay size fraction (2000 micrometers) and from the root fraction, not from the finer separates. The proportion of organic C as microbial biomass C revealed the low turnover of microbial C in the PP situations, especially in the clay size fraction of the NRPP soil. A common shift of AODC toward the finer separates from planted soils (CC and RPP) revealed the influence of living plants on the distribution of soil bacteria. The relative abundance of #A. brasilense showed the presence of the active roots of #Digitaria in the macroaggregates and their contact with the dispersible clay size fraction of the rhizosphere soil. (Résumé d'auteur

Analysis of genetic diversity in mango (Mangifera indica L.) using isozymetic polymorphism

The isozymetic study was designed for assessing the genetic diversity among the selected mango cultivars/genotype available in Bangladesh. All the isozymes, used in the present study showed polymorphism for mango. A total of 25 different electrophoretic zymotypes were observed for three isozymes studied. Glutamate oxaloacetate transaminase, malate dehydrogenase and peroxidase analysis possessed 8, 10 and 7 zymotypes, respectively, and genotypes were grouped into different electrophoretic zymotypes which indicated higher level of genetic diversity of mango. For glutamate oxaloacetate transminase, G6 was the most common zymotypes whereas G3, G5, and G8 were found in few cases. Similarly, M8 and M6 in malate dehydrogenase as well as P6 and P5 in peroxidase were found more frequent while other zymotypes in both isozymes were less frequent. Frequency was very few for one zymotype in all cases of three isozymes such as, G8, M10 and P7. Cluster analysis through UPGMA dendogram using isozymes electrophoretic pattern provided strong information about existence of variability among the genotypes of mango. Based on Euclidean distance, a dendogram was constructed using banding pattern of 60 mango genotypes developed through three isozymes activities. The dendogram showed eight major clusters designated as I, II, III, IV, V, VI, VII and VIII. The results generated with isoenzyme will be helpful in improvement as well as may guide us in designing strategies that maximize the utility of genetic resources.Key words: Polymorphism, isozyme, mango, genetic diversity, variety

Nanoscale color control of TiO2 films with embedded Au nanoparticles

Article in pressWe demonstrate an efficient nanoscale control of the optical properties of TiO2 films by tuning the Surface Plasmon Resonance (SPR) in the embedded Au nanoparticles. The films were grown by reactive magnetron sputtering. SPR tuning was achieved by different annealings, which affected the shape and size of the Au nanoparticles, and also the phase of the dielectric matrix. These changes promoted the variations on the optical properties. As shown by the modeling of the effective dielectric function of the TiO2/Au in the SPR region, the variation of their optical absorption spectra correlates with morphological changes.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/70037/2006

Exploitable options for curbing the danger of SARS-CoV-2 in Africa

Background: It is understood that coronavirus is highly mutated, in December, 2019 a new strain of coronavirus emerged which originated in Wuhan, from seafood. The pathogen was named novel coronavirus, while the disease it causes is known as Covid-19, the 2019 coronavirus disease. Bat is the major reservoir host of the virus. By putting bats in touch with other mammals will promote viral spillovers, which is a dominant condition for SARS-CoV-2, while also the effect of climate anomalies on food scarcity, behavioral flexibility, and bat immune modulation is likely to increase the risk of disease emergence. Over 34 million Covid-19 cases were registered between 31st of December 2019 and October 1st 2020 with Africa reporting about 1.4 million cases in this period. Aim: This review was design to highlight possible options that can be exploited in curbing the Covid-19 menace in Africa. Method: We reviewed articles from online databases for relevant documents written in English language. These includes NCBI, PubMed and Google scholar. We included both original and review papers that provided information on current SARS-CoV-2 trends and meta-analysis in Africa and globally. Results: Of the 15 articles selected from the 128 available citations, approximately 40 million people worldwide have been diagnosed with SARS-CoV-2, while only 1.4 million people in Africa have been confirmed to be positive for the virus as of October 1, 2020, although the prevalence in Africa is low in relative to other continents. However, most African nations do not have the economy to buy the vaccines that are accessible. The availability of phytoterapeutic agents, on the other hand, would provide a cost-effective way to tackle the Covid-19 threat in Africa. Conclusion: Cell lines adaptation in vaccine production, proteomic analysis of the viralhost interactomes, treatment approaches using natural occurring compounds, which will provide cost effective options to low-income countries can be adopted to curb the menace of Covid-19 in Africa

Simulation of High Conversion Efficiency and Open-circuit Voltages Of {\alpha}-si/poly-silicon Solar Cell

The P+ {\alpha}-Si /N+ polycrystalline solar cell is molded using the AMPS-1D device simulator to explore the new high efficiency thin film poly-silicon solar cell. In order to analyze the characteristics of this device and the thickness of N+ poly-silicon, we consider the impurity concentration in the N+ poly-silicon layer and the work function of transparent conductive oxide (TCO) in front contact in the calculation. The thickness of N+ poly-silicon has little impact on the device when the thickness varies from 20 {\mu}m to 300 {\mu}m. The effects of impurity concentration in polycrystalline are analyzed. The conclusion is drawn that the open-circuit voltage (Voc) of P+ {\alpha}-Si /N+ polycrystalline solar cell is very high, reaching 752 mV, and the conversion efficiency reaches 9.44%. Therefore, based on the above optimum parameters the study on the device formed by P+ {\alpha}-Si/N+ poly-silicon is significant in exploring the high efficiency poly-silicon solar cell.Comment: 8 pages 6figures, 1 table

Tuning of the surface plasmon resonance in TiO2/Au thin films grown by magnetron sputtering : the effect of thermal annealing

Nanocomposites consisting of a dielectric matrix, such as TiO2, with embedded noble metal nanoparticles (NPs) possess specific optical properties due to the surface plasmon resonance (SPR) effect, interesting for several applications. The aim of this work is to demonstrate that these properties are sensitive to the nanostructure of magnetron-sputtered TiO2/Au thin films, which can be tuned by annealing. We study the role of the shape and size distribution of the NPs, as well as the influence of the crystallinity and phase composition of the host matrix on the optical response of the films. All these characteristics can be modified by vacuum annealing treatments of the deposited films. A theoretical interpretation and modeling of the experimental results obtained is presented. The model involves a modified Maxwell-Garnett approach for the effective dielectric function of the composite (describing the SPR effect) and the transfer matrix formalism for multilayer optics. Input data are based on the experimental information obtained from the detailed structural characterization of the films. It is shown that the annealing treatments can be used for controlling the optical properties of the composite films, making them attractive for decorative coatings.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/70037/200