Biodegradation of rocket propellant waste, ammonium perchlorate

The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides

A survey on enhancing grid flexibility through bidirectional interactive electric vehicle operations

Smart grids (SG) constitute a revolutionary concept within the energy sector, enabling the establishment of a bidirectional communication infrastructure. This infrastructure significantly improves control, efficiency, and overall service quality in power systems. The study provides an in-depth survey on the classification of EVs, including both plug-in and non-plug-in EVs, and the integration process of V2G, including bidirectional power flow analysis. Moreover, various control strategies for EV integration are explored, ranging from centralized and decentralized to hierarchical control structures. Further, the research thoroughly examines the potential benefits of EV integration and addresses associated challenges, such as battery degradation, infrastructure requirements, cybersecurity and communication issues, grid congestion, and consumer behavior. The study goes beyond theoretical exploration and offers a comprehensive simulation analysis. This analysis leverages the storage capabilities of EVs to provide grid support services. A real-time dynamic dispatch strategy is formulated to integrate EVs into the automatic generation control of multi-energy systems. The findings demonstrate that EVs can effectively mitigate forecasting errors in a power network heavily reliant on wind energy sources. Consequently, the storage capabilities of EVs contribute to enhancing grid flexibility in managing the intermittency of renewable energy resources

Variations in Denitrification and Ventilation Within the Arabian Sea Oxygen Minimum Zone During the Holocene

The continental slope of India is exposed to an intense perennial oxygen minimum zone (OMZ) supporting pelagic denitrification. Sediments that are presently in contact with the lower boundary of the denitrification zone indicate marked changes in the intermediate and bottom waters ventilation of OMZ during the past 9,500 years. The δ15N of sediment suggests that the OMZ waters were less ventilated during the early Holocene (between 9.5 and 8.5 ka BP) resulting in intensified denitrifying conditions with an average δ15N value of 7.8‰, while at the same time stable Mo isotope composition (average δ98Mo of -0.02‰) indicates that the bottom waters that were in contact with the sediments were better oxygenated. By the mid-Holocene OMZ became more oxygenated suppressing denitrification (average δ15N of 6.2‰), while bottom waters gradually became less oxygenated (average δ98Mo of 1.7‰). The mid-Holocene reduction in denitrification coincided with a global decrease in atmospheric N2O as inferred from ice core records, which is consistent with a decreased contribution from the Arabian Sea. Since ~5.5 ka BP OMZ waters have again been undergoing progressive deoxygenation accompanied by increasing denitrification

Co-pyrolysis of Rice Husk with Underutilized Biomass Species: A Sustainable Route for Production of Precursors for Fuels and Valuable Chemicals

In this study, co-pyrolysis of rice husk with underutilized biomass, Napier grass and sago waste was carried out in a fixed bed reactor at 600 �C, 30 �C/min and 5 L/min nitrogen flowrate. Two-phase bio-oil (organic and aqueous) was collected and characterized using standard analytical techniques. 34.13–45.55 wt% total boil-oil yield was recorded using assorted biomass compared to pure risk husk biomass with 31.51 wt% yield. The organic phase consist mainly benzene derivatives with higher proportion in the oil from the co-pyrolysis process relative to the organic phase from the pyrolysis of the individual biomass while the aqueous phase in all cases was predominantly water, acids, ketones, aldehydes, sugars and traces of phenolics. This study has demonstrated a good approach towards increasing valorization of rice husk in a single reaction step for the production of high grade bio-oil, which can be transformed into fuel and valuable chemicals

Ghost-free braneworld bigravity

We consider a generalisation of the DGP model, by adding a second brane with localised curvature, and allowing for a bulk cosmological constant and brane tensions. We study radion and graviton fluctuations in detail, enabling us to check for ghosts and tachyons. By tuning our parameters accordingly, we find bigravity models that are free from ghosts and tachyons. These models will lead to large distance modifications of gravity that could be observable in the near future.Comment: Dedicated to the memory of Ian Kogan. Version to appear in Classical and Quantum Gravit

Factors influencing the approaches to studying of preclinical and clinical students and postgraduate trainees

<p>Abstract</p> <p>Background</p> <p>Students can be classified into three categories depending on their approaches to studying; namely, deep approach (DA), strategic approach (SA) and surface apathetic or superficial approach (SAA). The aim of this study was to identify factors affecting the approaches to studying among Sri Lankan medical undergraduates and post graduate trainees and to analyze the change in the pattern of study skills with time and experience.</p> <p>Method</p> <p>Pre-clinical and clinical students of the Faculty of Medicine, University of Colombo and postgraduate trainees in Surgery at the National Hospital of Sri Lanka were invited to complete the Approaches and Study Skills Inventory for Students (ASSIST) questionnaire.</p> <p>Results</p> <p>A total of 187 pre clinical (M: F = 96:91), 124 clinical (M: F = 61:63) and 53 post graduate trainees (M: F = 50:3) participated in the study. Approaches of male and female students were similar. SA was significantly affected by age among the preclinical students (p = 0.01), but not in other groups. Among pre-clinical students, males preferred a teacher who supported understanding (p = 0.04) but females preferred a passive transmission of information (p < 0.001). This, too, was not visible among other groups. A linear regression performed on group (batch), gender, island rank at GCE Advance Level (AL) examination, self appraisal score and the preference scores of type of teacher only managed to explain 35% or less of variance observed for each approach in individual groups.</p> <p>Conclusion</p> <p>Different factors affect the approach to studying in different groups but these explain only a small fraction of the variance observed.</p

Islamic Monetary Economics: Insights from the Literature

This chapter reviews critical early literature of Islamic monetary economics. The prohibition of Riba has imposed challenges on Islamic economists to come up with the viable alternatives to achieve Islamic monetary policy goals. Our extensive review of theoretical and empirical literature indicates that equity based profit- and loss-sharing instruments have been proposed for conducting open market operations in an interest-free economy. Theoretically, the central bank can achieve desired goals by controlling money supply and profit-sharing ratios. The findings from empirical literature suggest that money demand tend to be more stable in an interest-free economy. Whether monetary transmission works through Islamic banking channel is controversial, but the literature is growing. These findings are not surprising as majority Muslim countries lack sustainable and equitable economic growth. Moreover, these countries suffer from higher inflation and unemployment with little or no monetary freedom due to fixed exchange rate regime, shallow financial markets and strict capital control

Synthesis, Characterization, and Biological Properties of Iron Oxide Nanoparticles Synthesized from Apis mellifera Honey

Green approaches for nanoparticle synthesis have emerged as biocompatible, economical, and environment-friendly alternatives to counteract the menace of microbial drug resistance. Recently, the utilization of honey as a green source to synthesize Fe2O3-NPs has been introduced, but its antibacterial activity against one of the opportunistic MDR pathogens, Klebsiella pneumoniae, has not been explored. Therefore, this study employed Apis mellifera honey as a reducing and capping agent for the synthesis of iron oxide nanoparticles (Fe2O3-NPs). Subsequent to the characterization of nanoparticles, their antibacterial, antioxidant, and anti-inflammatory properties were appraised. In UV-Vis spectroscopic analysis, the absorption band ascribed to the SPR peak was observed at 350 nm. XRD analysis confirmed the crystalline nature of Fe2O3-NPs, and the crystal size was deduced to be 36.2 nm. Elemental analysis by EDX validated the presence of iron coupled with oxygen in the nanoparticle composition. In ICP-MS, the highest concentration was of iron (87.15 ppm), followed by sodium (1.49 ppm) and other trace elements (&lt;1 ppm). VSM analysis revealed weak magnetic properties of Fe2O3-NPs. Morphological properties of Fe2O3-NPs revealed by SEM demonstrated that their average size range was 100–150 nm with a non-uniform spherical shape. The antibacterial activity of Fe2O3-NPs was ascertained against 30 clinical isolates of Klebsiella pneumoniae, with the largest inhibition zone recorded being 10 mm. The MIC value for Fe2O3-NPs was 30 µg/mL. However, when mingled with three selected antibiotics, Fe2O3-NPs did not affect any antibacterial activity. Momentous antioxidant (IC50 = 22 µg/mL) and anti-inflammatory (IC50 = 70 µg/mL) activities of Fe2O3-NPs were discerned in comparison with the standard at various concentrations. Consequently, honey-mediated Fe2O3-NP synthesis may serve as a substitute for orthodox antimicrobial drugs and may be explored for prospective biomedical applications. © 2023 by the authors.Princess Nourah Bint Abdulrahman University, PNU: PNURSP2023R108This research project was supported by the Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2023R108), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia

Observations of trace gases and aerosols over the Indian Ocean during the monsoon transition period

Characteristics of trace gases (O3, CO, CO2, CH4 and N2O) and aerosols (particle size of 2.5 micron) were studied over the Arabian Sea, equatorial Indian Ocean and southwest part of the Bay of Bengal during the monsoon transition period (October-November, 2004). Flow of pollutants is expected from south and southeast Asia during the monsoonal transition period due to the patterns of wind flow which are different from the monsoon period. This is the first detailed report on aerosols and trace gases during the sampled period as the earlier Bay of Bengal Experiment (BOBMEX), Arabian Sea Monsoon Experiment (ARMEX) and Indian Ocean Experiments (INDOEX) were during monsoon seasons. The significant observations during the transition period include: (i) low ozone concentration of the order of 5 ppbv around the equator, (ii) high concentrations of CO2, CH4 and N2O and (iii) variations in PM2.5 of 5-20&#956;g/m3