Effects of captan on the growth and cellulase production of Aspergillus aculeatus and Botryodiplodia theobromae

The effects of captan on the production of mycelia and cellulolytic enzymes of Aspergillus aculeatus and Botryodiplodia theobromae were investigated in culture. There was decrease in mycelia of both fungi with increase in captan concentration in ppm. No fungal growth was recorded at 400 ppm. Captan at 10–50 ppm at 25 and 30 °C induced both fungi to produce more mycelia than in control cultures. The effect of captan concentration on the production of cellulases showed a decrease in quantity with increase in concentration. At 400 ppm no cellulase was produced by both fungi. There was a general decrease in cellulase production with increase in temperature either in control or experimental cultures. In cultures incorporated with captan, the cellulolytic activities of A. aculeatus (at 10 ppm) and B. theobromae (at 10 ppm, 50 ppm) were found to be relatively high.     

Amylase activities and cyanide tolerance of five cassava tuber spoilage molds

Studies on the amylase activities and tolerance to cyanide by five spoilage molds of cassava tuber were carried out. None of the test fungi grew in 0.1 g/ml concentration of potassium cyanide while only Aspergillus aculeatus and A. niger grew in 0.05 g/ml. Except for B. theobromae, all the other four molds synthesised amylases on the 2nd day of incubation. Highest amylase activities by the molds were recorded between pH 6–7 and at 25°C. The molds degraded satisfactorily the raw starch and protein contents of the blended cassava tuber pulp. Total reducing sugars were detected in large quantities from the mold deteriorated cassava tuber.     

Sustainability indicators for the assessment of nuclear power

Electricity supplies an increasing share of the world’s total energy demand and that contribution is set to increase. At the same time, there is increasing socio-political will to mitigate impacts of climate change as well as to improve energy security. This, in combination with the desire to ensure social and economic prosperity, creates a pressing need to consider the sustainability implications of future electricity generation. However, approaches to sustainability assessment differ greatly in their scope and methodology as currently there is no standardised approach. With this in mind, this paper reviews sustainability indicators that have previously been used to assess energy options and proposes a new sustainability assessment methodology based on a life cycle approach. In total, 43 indicators are proposed, addressing the techno-economic, environmental and social sustainability issues associated with energy systems. The framework has been developed primarily to address concerns associated with nuclear power in the UK, but is applicable to other energy technologies as well as to other countries.     

Nuclear renaissance,public perception and design criteria: An exploratory review

There is currently an international drive to build new nuclear power plants, bringing about what is being termed a “nuclear renaissance”. However, the public perception of nuclear energy has historically been, and continues to be, a key issue, particularly in light of the Fukushima nuclear incident. This paper discusses the disparity between perceived and calculated risks based on the last four decades of research into risk perception. The leading psychological and sociological theories, Psychometric Paradigm and Cultural Theory, respectively, are critically reviewed. The authors then argue that a new nuclear-build policy that promotes a broader approach to design incorporating a wider range of stakeholder inputs, including that of the lay public, may provide a means for reducing the perceived risk of a nuclear plant. Further research towards such a new approach to design is proposed, based on integrating expert and lay stakeholder inputs and taking into account broader socio-cultural factors whilst maintaining the necessary emphasis on safety, technological development, economics and environmental sustainability.     

Light aversion in mice depends on nonimage-forming irradiance detection.

Detection of light in the eye underlies image-forming vision, but also regulates adaptive responses in physiology and behavior. Typically these adaptive responses do not involve image-forming vision, but depend on a relatively absolute measure of brightness (nonimage-forming irradiance detection). The goal of this study was to further understand how image-forming vision and nonimage-forming irradiance detection contribute to the effects of light on behavior. Three light dependent behaviors were assessed in wild-type, Rpe65-/- and rd1 mice. In Rpe65-/- mice, nonimage-forming irradiance detection is severely attenuated, but rod based visual acuity is relatively preserved. In rd1 mice visual acuity is nonrecordable, but nonimage-forming responses are less severely attenuated than Rpe65-/-. Positive masking, an image-forming vision dependent increase in wheel running, was absent in rd1 and restricted to higher irradiances in Rpe65-/-. Negative masking, a suppression of wheel running sensitivity with nonimage-forming irradiance detection input, was increased in rd1, but reduced in Rpe65-/- mice. By contrast, light aversion, an avoidance of brightly lit areas, was abolished in both Rpe65-/- and rd1. This shows that image-forming vision is not sufficient for light aversion, suggesting nonimage-forming irradiance detection motivates this behavior. Further, the differing effects of disease suggest that negative masking and light aversion are distinct responses with specialized nonimage-forming irradiance detection pathways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Power generation scenarios for Nigeria: An environmental and cost assessment

Exploratory scenarios for the power sector in Nigeria are analysed in this paper using possible pathways within the Nigerian context and then compared against the Government's power expansion plan in the short to medium term. They include two fossil-fuel (FF and CCGT) and two sustainable-development-driven scenarios (SD1 and SD2). The results from the FF scenarios indicate this is the preferred outcome if the aim is to expand electricity access at the lowest capital costs. However, the annual costs and environmental impacts increase significantly as a consequence. The SD1 scenario, characterised by increased penetration of renewables, leads to a reduction of a wide range of environmental impacts while increasing the annual costs slightly. The SD2 scenario, also with an increased share of renewables, is preferred if the aim is to reduce GHG emissions; however, this comes at an increased annual cost. Both the SD1 and SD2 scenarios also show significant increases in the capital investment compared to the Government's plans. These results can be used to help inform future policy in the Nigerian electricity sector by showing explicitly the range of possible trade-offs between environmental impacts and economic costs both in the short and long terms.     

Modelling the surface adsorption of methane on carbon nanostructures

Methane (CH₄) adsorption is investigated on both graphite and in the region between two aligned single-walled carbon nanotubes, which we refer to as the groove site. We exploit the Lennard–Jones potential function and the continuous approximation to determine surface binding energies between a single CH₄ molecule and graphite and between a single CH₄ and two aligned single-walled carbon nanotubes. Our modelling indicates that for a CH₄ molecule interacting with graphite, the binding energy of the system is minimized when the CH₄ carbon is 3.83 Å above the surface of the graphitic carbon, while the binding energy of the CH₄–groove site system is minimized when the CH₄ carbon is 5.17 Å away from the common axis shared by the two aligned single-walled carbon nanotubes. Our results confirm the current view that for larger groove sites, CH₄ molecules in grooves are likely to move towards the outer surfaces of one of the single-walled carbon nanotubes. Our results are computationally efficient and are in good agreement with experiments and molecular dynamics simulations, and show that CH₄ adsorption on graphite and groove surfaces is more favourable at lower temperatures and higher pressures.     

Studies on nutritional requirements of the. latent phase of Ceratocystis paradoxa — the pineapple soft rot pathogen in Nigeria

The investigations on the nutritional requirements of the latent phase of Ceratocystis paradoxa causing ripe pineapple fruit rots were studied. The glucose, total protein and calcium ions levels were higher in ripe fruits than in unripe fruits. However, the ascorbic acid content was lower in the ripe fruits. All the carbon and nitrogenous compounds tested supported the growth of the fungus with D-glucose and casein hydrolysate providing the best carbon and nitrogenous sources respectively. The boiled extracts of unripe fruit rind at 60 °C and 80 °C were inhibitory to conidia germination. The carbohydrate and nitrogenous infusions at 1 % and 3 % induced unripe pineapple fruit rots of C. paradoxa. All the infusions at 10% concentrations were inhibitory to the development of the fungal pathogen.     

Entropy generation minimization on electromagnetohydrodynamic radiative Casson nanofluid flow over a melting Riga plate

Minimizing entropy generation is a technique that helps improve the effectiveness of real processes by studying the associated irreversibility of system performance of nanofluid. This study examines the entropy generation analysis of electromagnetohydrodynamic radiative Casson flow induced by a stretching Riga plate in a non-Darcian porous medium under the influence of internal energy change, Arrhenius activation energy, chemical reaction, and melting heat transfer. The thermophysical features of the fluid are assumed constant in most of the literature. However, this current research bridges this gap by considering viscosity, conductivity, and diffusivity as temperature-dependent variables. Also, the exponential decaying Grinberg term is used as a resistive force in this investigation due to the electromagnetic properties of the Riga plate in the momentum conservation equation. Some suitable dimensionless variables are introduced to remodel the transport equations into unitless ones and then solved numerically by employing Galerkin Weighted Residual Method. Analyses reveal that the Casson parameter declines the fluid velocity, while the existence of the melting parameter has the opposite effect. Also, this article includes some future recommendations.     

Lipolytic activities of two strains of Aspergillus aculeatus associated with the spoilage of two food sources

The production of extracellular lipolytic enzymes by 2 strains of Aspergillus aculearus associated with the deterioration of peanuts and a marketed margarine in Nigeria and the effects of temperature and pH on the activities of the enzymes were investigated. Lipolytic enzymes were detected within 2 days of incubation at 35 °C in 4 out of 6 natural oils and in 3 out of 4 synthetic glycerides used irrespective of strain type. The lipolytic enzymes of both strains hydrolysed both natural oils and synthetic glycerides to free fatty acids. There was correlation between the mycelium produced to the quantity of free fatty acids produced in medium within the first 8 days of incubation. There was a general increase in mycelium production with increase in incubation period. The enzyme activities were at peak at 30-35 °C and at pH 6-7.