Local Damage of Plain and Reinforced Concrete Targets under Impact Load

In the present study, simplified models for calculating the penetration depth, scabbing, and perforation thicknesses for concrete targets have been proposed. These models consider the dynamic strain rate effect in the estimation of penetration parameters. The results of proposed model have been compared with the experimental data

Sustainability Practices and Supply Chain Resilience in the Development of a Circular Economy: A Study of Nigeria

Sustainable Supply Chain Management has become an essential portion of business strategy for almost all sectors. However, not so much is understood about the wider effects of sustainability practices on the ability of the SC to endure disruptions. The aim of this study was therefore to scrutinize the effect of sustainability practices on supply chain resilience in the development of a circular economy in Nigeria. This study was steered within the horizon of qualitative method with a philosophical research paradigm of constructivism. The study used twenty-one (21) Consumer Goods Firm in Nigeria as population and sample. Primary data was explored using key informant interview. Thematic analysis was used to analyze the data collected. The study reveals that sustainability practices contribute to supply chain resilience in the development of a circular economy. The research concluded that, cradle to cradle practice, environmental sustainability, economic sustainability, and social sustainability play a major role in ensuring resiliency of consumer goods firms’ supply chains especially in developing a circular economy. The outcome of this research is expected to lead to the development of a circular economy in Nigeria. The study will be of significance to Nigerian government, consumer goods companies, practitioners, regulatory bodies, and researchers

Can One See the Number of Colors?

We formulate the standard model with an arbitrary number of colors N_c. The cancellation of Witten's global SU(2)_L anomaly requires N_c to be odd, while the cancellation of triangle anomalies determines the consistent N_c-dependent values of the quark charges. In this theory, the width of the neutral pion decay into two photons is not proportional to (N_c)^2. In fact, in the case of a single generation and hence for two quark flavors (N_f = 2), N_c does not appear explicitly in the low-energy effective theory of the standard model. Hence, contrary to common lore, it is impossible to see the number of colors in low-energy experiments with just pions and photons. For N_f > 2, on the other hand, N_c explicitly enters the chiral Lagrangian as the quantized prefactor of the Wess-Zumino-Witten term, but the contribution of this term to photon-pion vertices is completely canceled by the N_c-dependent part of a Goldstone-Wilczek term. However, the width of the eta decay into pi^+ pi^- gamma survives the cancellation and is indeed proportional to (N_c)^2. By detecting the emerging photon, this process thus allows one to literally see N_c for N_f > 2.Comment: 24 pages, no figures, Late

A model study of surface state on optical bandgap of silicon nanowires

A theoretical approach is carried out to study the role of surface state in silicon nanowires. The influences of size and surface passivation on the bandgap energy and photoluminescence spectra of silicon nanowires with diameter between 4 to 12nm are examined. It is observed that visible PL in silicon nanowires is due to quantum confinement and surface passivation. But the energy recombination of electron and holes in the quantum confined nanostructures is responsible for the visible PL. In this work, models from quantum bandgap and photoluminescence intensity are adopted to explain the size dependent surface luminescence. Investigation show that the nanowires of smaller size with surface impurities revealed higher bandgap energy. Oxygenated surface is found to have higher energy than hydrogenated surface. The features of PL spectra of Si nanowires suggest that these models are significant for understanding the mechanism of visible PL from SINWs.Keywords: Photoluminescence, Surface State, Band gap, Quantum Confinemen

Biosynthesis, characterization and antimicrobial study of silver nanoparticles (agNPs)

In this paper, biological synthesis of silver nanoparticles (AgNPs) using Syzygium guineenses stem extract with 1mM, 2mM and 3mM AgNO3 concentrations has been presented. The plant extract was prepared with distilled water. The characterization and morphological composition of the synthesized AgNPs were determined by UV-visible spectroscopy and SEM respectively, while FTIR analysis was performed to identify the presence of the possible functional groups in the synthesized nano particles. It was observed from the UV and SEM analyses that the particles formed have diameters in the range of 23.5nm - 89.3nm, which is the range of nanoparticle size. Antibacterial test was carried out on the sample with six pathogenic microbes (Methicillin Resistant Staphylococus aureas, Vancomycin Resistant Entrococci, Staphylococcus aureas, Bacillus sublitis, Escherichia coli, and Pseudomonas aeruginosa) to ascertain the antimicrobial activity of the synthesized AgNPs. Both the characterization and antimicrobial activity test were very successful and could lead to significant economic viability, as well as being environmentally friendly for treatment of some infectious diseases.Keywords: Syzygium guineenses, Green Chemistry, Spectroscopy, Optoelectronics, Biomedical Sensor

Investigation of para-sulfonatocalix[n]arenes [n = 6, 8] as potential chelates for 230U

International audienceLiterature reports of the efficacy of para-sulfonatocalix[6]- and calix[8]-arenes as U(VI) complexants indicated that they might be useful for in vivo chelation of the novel therapeutic alhpa-emitter 230U. We have studied the complexation of U(VI) with para-sulfonatocalix[6]arene and para-sulfonatocalix[8]arene by time resolved laser induced fluorescence spectroscopy and using competition methods with Chelex resin and 4-(2-pyridylazo)resorcinol in simplified and in biological media. New thermodynamic parameters describing the stability of U(VI)-para-sulfonatocalix[n]arene [n = 6, 8] complexes were obtained. Although the interactions are strong, the complexes do not exhibit sufficient stability to compete with carbonate ions and serum proteins for complexation of U(VI) under physiological conditions

Effect of Copper, Manganese and Zinc With Antioxidant Vitamins on Pulse Rate and Lipid Profile of Salt-Loaded Albino Rats

Hypertension and dyslipidemia are associated with oxidative stress and are major causes of cardiovascular diseases amounting to 30% of global death rate. The effect of antioxidants supplementation on pulse rate and lipid profile in salt-loaded albino rats were investigated using a randomized control study with 30 albino rats divided into 5 experimental groups of 6 rats each. Groups 1 and 2 were normal untreated and salt-induced untreated respectively. Groups 3-5 were treated with Vitamins (A, C and E) with Cu, Mn and Zn respectively. Hypertension and dyslipidemia were induced using Salt-loading method (8% NaCl) for a period of five (5) weeks where Group 1 received normal rat feed and Groups 2-5 received salt-loaded diet. The heart rate of the rats was measured before and after the salt loading and dyslipidaemia was assessed at the end of the experiment. The results indicated that salt loading induced significant increase (

Pattern of panic-buying and its psychosocial correlates among Pakistani adults during COVID-19 pandemic

Background: As the COVID-19 pandemic rages on, one bizarre yet ubiquitous human behavior has resurfaced. Globally, people have engaged in panic buying and hoarding (PBH). This irrational practice of panic buying is driven by deficient, manipulated news amid COVID-19 crisis.Methods: A cross-sectional study was conducted with Pakistani adults (≤18 years). Data was collected through an anonymous self-reported online survey from 17th April 2020 (0800 hours) through 20th April 2020 (2200 hours) via social media platforms. The survey consisted of sociodemographic characteristics, questions regarding food/essential supplies PBH and its psychosocial correlates- attitudes about COVID-19 severity (CA), values related to social responsibility (SR), social trust (ST), and self-interest (SI). Data was entered and analyzed using IBM Statistical package for social sciences (SPSS) version 20.Results: There were 786 participants in the survey; 59% were females. Mean age was 26.6±7.6 years. Mean PBH score was 2.31±0.85 (range: 1-5). Overall, 28.4% hoarded supplies a few times or more and 47% agreed to have bought more food/essential supplies due to COVID-19. Correlation analysis showed a 12.3% positive correlation of PBH with ST and 8.5% positive correlation with SI (p<0.05). In the multivariate regression model, PBH showed a statistically significant (p<0.05) positive impact on ST and SI.Conclusions: More than one-fourth of the individuals indulged in panic buying and hoarding during the COVID-19 in Pakistan. Fear of contracting the virus and uncertainty about the duration of lockdown was the common reasons behind PBH. Social trust and self-interest were significant psychosocial contributors to hoarding behavior.