Green Synthesis of Silver Nanoparticles from Cis-Bixin and Cis-Norbixin: Potential Application for Fuel Desulfurisation

Green methods have been actively pursued in recent years as an efficient, inexpensive and environmentally safe approach for nanoparticle formation over the conventional chemical methods. Nanoparticle mediated adsorptive desulfurisation has been considered as an alternative, ecofriendly approach for fuel desulfurisation. Fuel desulfurisation is indispensible due to the fact that the combustion of fuels containing sulfur compounds release sulfur oxide compounds into environment and engenders devastating consequences on the chemistry of atmosphere. The present investigation devoted to the possibility of green synthesis of silver nanoparticles (AgNPs) using cis-bixin and cis-norbixin carotenoids as reducing and stabilising agents and the possibility of synthesised nanoparticles for removal of sulfur compounds in fuel. Cis-bixin was extracted from the pericarp of the seeds of Achiote (Bixaorellana) tree and cis-norbixin was synthesised from cis-bixin. The synthesized AgNPs from both carotenoids were characterised using UV-Visible spectroscopic technique for Surface Plasmon Resonance and absorbance peaks were obtained at 391 nm for cis-bixin and 405 nm for cis-norbixin AgNPs. The effect of temperature, pH, ionic strength of AgNO3 solution, time and stability of the formed AgNPs under electrolytic conditions were studied using UV-Visible spectroscopy and results revealed that the room temperature was paragon for optimum synthesis and AgNPs were stable in slightly acidic, neutral and slightly basic pHs and in different concentrations of NaCl (upto 0.2 M for cis-bixin and upto 0.3 M for cisnorbixin AgNPs). Synthesised AgNPs were used to investigate the fuel desulfurisation potential by using commercial kerosene as testing fuel material. For the comparative purposes NaBH4 reduced AgNPs were used. The adsorption of sulfur compounds in oil medium onto surface of AgNPs in aqueous medium produce self-assembled sulfur compounds adsorbed AgNP layer (interfacial material) on the oil/aqueous interface. The potential of the synthesised AgNPs for desulfurisation of kerosene was confirmed by analysing the sulfur content in each kerosene sample and formed interfacial material through X-Ray Fluorescence (XRF) spectroscopy. The formed interfacial material was further characterised through FTIR spectroscopy. The XRF results revealed that the AgNPs synthesised from cis-norbixin has the highest capability to reduce considerable amount of sulfur in kerosene compared to the other synthesised AgNPs. This study reports the possibility of rapid green synthesis of AgNPs form cis-bixin and norbixin under room temperature and feasible pH conditions followed by the capability for desulfurisation of fuel.Keywords: Green synthesis, Silver nanoparticles, Cis-Bixin, Cis-Norbixin, Fuel desulfurisatio

Presenteeism and Its Conceptualization: A Literature Review

Abstract Presenteeism is a comparatively new phenomenon in the study of occupational behaviors which evolved throughout the past few decades. Increasing interest in managing presenteeism effectively emerged as a new source of competitive advantage in current organizations. With definitional confusion, the most scholarly conception of presenteeism involves the employee’s attending to work while being ill. However, the definition has been more recently extended to include other conditions and events that limit productivity. Now focus is moving from single dimension to multiple dimensions of presenteeism. Accordingly, this conceptual paper traces the development of interest in presenteeism with consideration of its various conceptualizations which are important theoretically and practically. The paper may be useful to those who are interested in understanding the concept of presenteeism for future research studies. Key Words: Conceptualization, Presenteeism, Sickness Presenteeis

On the diffusion of lattice matched InGaAs/InP microstructures

Copyright (2003) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in F. Bollet et al., J. Appl. Phys. 93, 3881 (2003) and may be found at http://link.aip.org/link/?jap/93/388

A Study of the Removal Characteristics of Cu (II) Ions from Aqueous Solutions By a Low-Cost Adsorbent

Heavy metal pollution has become one of the most critical environmental problemsthroughout the world today, since they persist in the environment without degradation.Present study explores the feasibility of using Jak wood sawdust as a low cost adsorbent, forthe removal of Cu(II) ions from aqueous solutions. Batch mode process was carried out toinvestigate the effect of contact time, initial metal concentration, particle size, pH andtemperature with the dosage of 0.500 g sawdust treated with 0.1% sodium hydroxide.Maximum adsorption for Cu(II) was observed at pH 7 having the particle size 107-150 μm.Percentage removal of Cu(II) increased when temperature was varied from 20 C to 70 C.Langmuir, Freundlich and D-R isotherms were obtained at 30±0.2 C. Applicability ofpseudo-first order, pseudo-second order, intra-particle diffusion and liquid-film diffusionkinetic models were investigated at 30±0.2 C. Cu(II) removal by Jack wood sawdust obeyedpseudo-second order kinetic model, Langmuir and D-R isotherms. Maximum removalcapacity obtained from Langmuir and D-R isotherms are 6.26 and 5.51 mg g-1 respectively.Thermodynamic parameters ΔG, ΔS and ΔH obtained for the removal was (-) 8,52 kJmol-1and 0.2 kJmol-1K-1 respectively indicating the removal process is favourable andspontaneous. IR analysis of sawdust before and after the removal of Cu(II) was carried out toidentify the possible functional groups responsible for the removal and significant changes inthe intensities of functional groups of metal loaded sawdust was observed with shifts inpositions of some peaks. This research can be considered as a demonstration of using a wastematerial (sawdust) having a low economic value to solve an environmental problem such asdecontamination of industrial effluents.Keywords: Jak wood sawdust, Copper remova

The structural invisibility of outsiders: the role of migrant labour in the meat-processing industry

This article examines the role of migrant workers in meat-processing factories in the UK. Drawing on materials from mixed methods research in a number of case study towns across Wales, we explore the structural and spatial processes that position migrant workers as outsiders. While state policy and immigration controls are often presented as a way of protecting migrant workers from work-based exploitation and ensuring jobs for British workers, our research highlights that the situation ‘on the ground’ is more complex. We argue that ‘self-exploitation’ among the migrant workforce is linked to the strategies of employers and the organisation of work, and that hyper-flexible work patterns have reinforced the spatial and social invisibilities of migrant workers in this sector. While this creates problems for migrant workers, we conclude that it is beneficial to supermarkets looking to supply consumers with the regular supply of cheap food to which they have become accustomed

The contribution of gestational age, area deprivation and mother's country of birth to ethnic variations in infant mortality in England and Wales: A national cohort study using routinely collected data

OBJECTIVES: We aimed to describe ethnic variations in infant mortality and explore the contribution of area deprivation, mother's country of birth, and prematurity to these variations. METHODS: We analyzed routine birth and death data on singleton live births (gestational age≥22 weeks) in England and Wales, 2006-2012. Infant mortality by ethnic group was analyzed using logistic regression with adjustment for sociodemographic characteristics and gestational age. RESULTS: In the 4,634,932 births analyzed, crude infant mortality rates were higher in Pakistani, Black Caribbean, Black African, and Bangladeshi infants (6.92, 6.00, 5.17 and 4.40 per 1,000 live births, respectively vs. 2.87 in White British infants). Adjustment for maternal sociodemographic characteristics changed the results little. Further adjustment for gestational age strongly attenuated the risk in Black Caribbean (OR 1.02, 95% CI 0.89-1.17) and Black African infants (1.17, 1.06-1.29) but not in Pakistani (2.32, 2.15-2.50), Bangladeshi (1.47, 1.28-1.69), and Indian infants (1.24, 1.11-1.38). Ethnic variations in infant mortality differed significantly between term and preterm infants. At term, South Asian groups had higher risks which cannot be explained by sociodemographic characteristics. In preterm infants, adjustment for degree of prematurity (<28, 28-31, 32-33, 34-36 weeks) fully explained increased risks in Black but not Pakistani and Bangladeshi infants. Sensitivity analyses with further adjustment for small for gestational age, or excluding deaths due to congenital anomalies did not fully explain the excess risk in South Asian groups. CONCLUSIONS: Higher infant mortality in South Asian and Black infants does not appear to be explained by sociodemographic characteristics. Higher proportions of very premature infants appear to explain increased risks in Black infants but not in South Asian groups. Strategies targeting the prevention and management of preterm birth in Black groups and suboptimal birthweight and modifiable risk factors for congenital anomalies in South Asian groups might help reduce ethnic inequalities in infant mortality

Bacteria mediated silver nanoparticles: comparison as potent antibiofilm agents

Introduction: Biosynthesized silver nanoparticles (AgNPs) have good antimicrobial properties comparable to chemically synthesized silver nanoparticles. Further, they have good potential as antibiofilm agents.Methods: AgNPs were synthesized from Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923) and Acinetobacter baumannii (confirmed clinical isolate) and physically characterized by several techniques. The antibiofilm activity of the AgNPs against biofilms of P. aeruginosa, S. aureus and C. albicans was studied using crystal violet assay. Biofilms were formed in 96-well polystyrene plates and treated with biosynthesized AgNPs for 24 and 48 h.Results: AgNPs synthesized by all bacteria except S. aureus mediated AgNPs displayed 50% biofilm inhibition at AgNP concentrations between 1.98 - 0.225 mg/ml. S. aureus mediated AgNPs showed 50% biofilm inhibition only against S. aureus biofilm. Scanning Electron microscopic images indicated that biosynthesized AgNPs were able to decrease surface coverage of biofilms and to reduce the extracellular matrix causing morphological changes in biofilms noticeably.Conclusion: This study reports the antibiofilm activity of bacteria mediated AgNPs. This is the first report on antibiofilm activity of AgNPs synthesized by Acinetobacter baumannii and also as a comparison of antibiofilm activity of several bacteria mediated AgNPs. According to the results, low dosages of green AgNPs can be applied in treating drug-resistant microbial infections in a cost effective manner. In conclusion, the bacterial synthesized AgNPs have antibiofilm activity and good stability suggesting its usefulness as economic and environmental friendly antibiofilm agents.</p

The Sri Lankan twin registry biobank: South Asia's first twin biobank

Introduction: Biobanks are a valuable resource for creating advancements in science through cutting-edge omics research. Twin research methods allow us to understand the degree to which genetics and environmental factors contribute to health outcomes. Methods: The Sri Lankan Twin Registry biobank (SLTR-b) was established in 2015 as part of Colombo Twin and Singleton Follow-up Study. Venous blood and urine were collected from twins and comparative sample of singletons for clinical investigations and biobanking. Results: The SLTR-b currently houses 3369 DNA and serum samples. Biobank specimens are linked to longitudinal questionnaire data, clinical investigations, anthropometric measurements, and other data. Discussion: The SLTR-b aims to address gaps in health and genetics research. It will provide opportunities for academic collaborations, local and international, and capacity building of future research leaders in twin and omics research. This paper provides a cohort profile of the SLTR-b and its linked data, and an overview of the strategies used for biobanking