797 research outputs found
Appraising the combustion of biogas for sustainable rural energy needs
This paper shows the combustion of biogas in rural households’ appliances. Biogas has been known since 1800s as an odourless and colourless gas with high combustion rate. Its use is beginning to gain ground in most developing countries like Nigeria due to its availability, ease of generation and environmental friendliness. Developing countries are characterized by poor infrastructural development, inadequate energy and water supply, poor health delivery system, etc. which hinders economic and social development. Most sources of rural households’ energy are firewood, animal dung, crop residue and kerosene which are associated with negative environmental impacts. The study was carried-out by articulation of past literatures on biogas combustion and consumption in household’s appliances and internal combustion engines. The study ascertains from the past studies high efficiency of biogas compared with natural gas and liquid petroleum gas (LPG) on stove-top burner, oven and two panel flue heater. It was observed that, biogas consumption is higher in all the appliances under investigation as compared to natural gas and LPG. The study recommended public enlightenment on biogas technology and its associate benefits to rural areas. The government and NGOs should encourage the application of this technology through financing of pilot projects in community leaders’ households which will extend to the populace. The technology should also be embraced because it is associated with environmental hygiene.Key words: Efficiency, hygiene, sustainability, developing countries, biogas
Trade finance in East Asia - potential responses to the shortfall
The crisis of 2008 saw many European banks reduce their provision of trade finance in East Asia. Notwithstanding the actions of the G20 and other bodies to redress this, a substantial shortfall in trade finance facilities in the region remains. This article explores the development of this shortfall, and analyses potential responses to it.
These responses range from some much-needed further revisions to the Basle III rules, to deepening of cross-border cooperation, creating a ring-fenced liquidity pool for trade finance, encouraging co-financing among the various providers of trade finance both private and public, and establishing a regional trade finance database. In addition, the article ponders the likelihood of China’s banks beginning to take a substantial role in providing trade finance to the region. Trade finance offers China’s banks a low risk means of expanding into international business, and offers China a way to provide the sort of important service to its region that regional leaders typically seek to provide.postprin
Trade Finance in East Asia: Potential Responses to the Shortfall
The crisis of 2008 saw many European banks reduce their provision of trade finance in East Asia. Notwithstanding the actions of the Group of Twenty and other bodies to redress this, a substantial shortfall in trade finance facilities in the region remains. This article explores the development of this shortfall and analyses potential responses to it. These responses range from some much needed further revisions to the Basel III rules, to the deepening of cross-border cooperation, creating a ring-fenced liquidity pool for trade finance, encouraging co-financing among the various providers of trade finance both private and public and establishing a regional trade finance database. In addition, the article ponders the likelihood of China’s banks beginning to take a substantial role in providing trade finance to the region. Trade finance offers China’s banks a low risk means of expanding into international business and offers China a way to provide the sort of important service to its region that regional leaders typically seek to provide.postprin
Perception of Hazards Associated with Cooking Fuel in Building Indoor Environment
This study assessed perception of hazards from cooking fuels in building indoor environment. One hundred questionnaires were randomly administered to selected households in high density settlement of Zaria metropolis with 96% response rate received. Results showed that females are dominant (83%) users of cooking fuels, kerosene (48.1%) and firewood (29.2%) are common types of cooking fuel use by the households. Factors that determine the use of these fuels are cost (28.2%) and types of stove (19.8%). Awareness level of associated hazards is high (62.5%) and frequency of health problems associated with pollutants (39.6%) is alarming. Opening of windows (47.9%) and isolation of cooking area from living area (42.7%) were the common control measures adopted. It is recommended that public enlightenment on health issues relating to indoor air pollution should be emphasized, as well as implementing codes for control of pollution in the indoor environment
Isolation and purification of Cu-free methanobactin from Methylosinus trichosporium OB3b
<p>Abstract</p> <p>Background</p> <p>The isolation of highly pure copper-free methanobactin is a prerequisite for the investigation of the biogeochemical functions of this chalkophore molecule produced by methane oxidizing bacteria. Here, we report a purification method for methanobactin from <it>Methylosinus trichosporium </it>OB3b cultures based on reversed-phase HPLC fractionation used in combination with a previously reported resin extraction. HPLC eluent fractions of the resin extracted product were collected and characterized with UV-vis, FT-IR, and C-1s NEXAFS spectroscopy, as well as with elemental analysis and ESI-MS.</p> <p>Results</p> <p>The results showed that numerous compounds other than methanobactin were present in the isolate obtained with resin extraction. Molar C/N ratios, mass spectrometry measurements, and UV-vis spectra indicated that methanobactin was only present in one of the HPLC fractions. On a mass basis, methanobactin carbon contributed only 32% to the total organic carbon isolated with resin extraction. Our spectroscopic results implied that besides methanobactin, the organic compounds in the resin extract comprised breakdown products of methanobactin as well as polysaccharide-like substances.</p> <p>Conclusion</p> <p>Our results demonstrate that a purification step is indispensable in addition to resin extraction in order to obtain pure methanobactin. The proposed HPLC purification procedure is suitable for semi-preparative work and provides copper-free methanobactin.</p
How large should whales be?
The evolution and distribution of species body sizes for terrestrial mammals
is well-explained by a macroevolutionary tradeoff between short-term selective
advantages and long-term extinction risks from increased species body size,
unfolding above the 2g minimum size induced by thermoregulation in air. Here,
we consider whether this same tradeoff, formalized as a constrained
convection-reaction-diffusion system, can also explain the sizes of fully
aquatic mammals, which have not previously been considered. By replacing the
terrestrial minimum with a pelagic one, at roughly 7000g, the terrestrial
mammal tradeoff model accurately predicts, with no tunable parameters, the
observed body masses of all extant cetacean species, including the 175,000,000g
Blue Whale. This strong agreement between theory and data suggests that a
universal macroevolutionary tradeoff governs body size evolution for all
mammals, regardless of their habitat. The dramatic sizes of cetaceans can thus
be attributed mainly to the increased convective heat loss is water, which
shifts the species size distribution upward and pushes its right tail into
ranges inaccessible to terrestrial mammals. Under this macroevolutionary
tradeoff, the largest expected species occurs where the rate at which
smaller-bodied species move up into large-bodied niches approximately equals
the rate at which extinction removes them.Comment: 7 pages, 3 figures, 2 data table
Cytomegalovirus Infection of the Cervix Detected By Cytology and Histology: A Report of Five Cases
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72846/1/j.1365-2303.1993.tb00094.x.pd
How citation boosts promote scientific paradigm shifts and Nobel Prizes
Nobel Prizes are commonly seen to be among the most prestigious achievements
of our times. Based on mining several million citations, we quantitatively
analyze the processes driving paradigm shifts in science. We find that
groundbreaking discoveries of Nobel Prize Laureates and other famous scientists
are not only acknowledged by many citations of their landmark papers.
Surprisingly, they also boost the citation rates of their previous
publications. Given that innovations must outcompete the rich-gets-richer
effect for scientific citations, it turns out that they can make their way only
through citation cascades. A quantitative analysis reveals how and why they
happen. Science appears to behave like a self-organized critical system, in
which citation cascades of all sizes occur, from continuous scientific progress
all the way up to scientific revolutions, which change the way we see our
world. Measuring the "boosting effect" of landmark papers, our analysis reveals
how new ideas and new players can make their way and finally triumph in a world
dominated by established paradigms. The underlying "boost factor" is also
useful to discover scientific breakthroughs and talents much earlier than
through classical citation analysis, which by now has become a widespread
method to measure scientific excellence, influencing scientific careers and the
distribution of research funds. Our findings reveal patterns of collective
social behavior, which are also interesting from an attention economics
perspective. Understanding the origin of scientific authority may therefore
ultimately help to explain, how social influence comes about and why the value
of goods depends so strongly on the attention they attract.Comment: 6 pages, 6 figure
Do oral aluminium phosphate binders cause accumulation of aluminium to toxic levels?
<p>Abstract</p> <p>Background</p> <p>Aluminium (Al) toxicity was frequent in the 1980s in patients ingesting Al containing phosphate binders (Alucaps) whilst having HD using water potentially contaminated with Al. The aim of this study was to determine the risk of Al toxicity in HD patients receiving Alucaps but never exposed to contaminated dialysate water.</p> <p>Methods</p> <p>HD patients only treated with Reverse Osmosis(RO) treated dialysis water with either current or past exposure to Alucaps were given standardised DFO tests. Post-DFO serum Al level > 3.0 μmol/L was defined to indicate toxic loads based on previous bone biopsy studies.</p> <p>Results</p> <p>39 patients (34 anuric) were studied. Mean dose of Alucap was 3.5 capsules/d over 23.0 months. Pre-DFO Al levels were > 1.0 μmol/L in only 2 patients and none were > 3.0 μmol/L. No patients had a post DFO Al levels > 3.0 μmol/L. There were no correlations between the serum Al concentrations (pre-, post- or the incremental rise after DFO administration) and the total amount of Al ingested.</p> <p>No patients had unexplained EPO resistance or biochemical evidence of adynamic bone.</p> <p>Conclusions</p> <p>Although this is a small study, oral aluminium exposure was considerable. Yet no patients undergoing HD with RO treated water had evidence of Al toxicity despite doses equivalent to 3.5 capsules of Alucap for 2 years. The relationship between the DFO-Al results and the total amount of Al ingested was weak (R<sup>2 </sup>= 0.07) and not statistically significant. In an era of financial prudence, and in view of the recognised risk of excess calcium loading in dialysis patients, perhaps we should re-evaluate the risk of using Al-based phosphate binders in HD patients who remain uric.</p
Considering the role of cognitive control in expert performance
© 2014, Springer Science+Business Media Dordrecht. Dreyfus and Dreyfus’ (1986) influential phenomenological analysis of skill acquisition proposes that expert performance is guided by non-cognitive responses which are fast, effortless and apparently intuitive in nature. Although this model has been criticised (e.g., by Breivik Journal of Philosophy of Sport, 34, 116–134 2007, Journal of the Philosophy of Sport, 40, 85–106 2013; Eriksen 2010; Montero Inquiry:An interdisciplinary Journal of Philosophy, 53, 105–122 2010; Montero and Evans 2011) for over-emphasising the role that intuition plays in facilitating skilled performance, it does recognise that on occasions (e.g., when performance goes awry for some reason) a form of ‘detached deliberative rationality’ may be used by experts to improve their performance. However, Dreyfus and Dreyfus (1986) see no role for calculative problem solving or deliberation (i.e., drawing on rules or mental representations) when performance is going well. In the current paper, we draw on empirical evidence, insights from athletes, and phenomenological description to argue that ‘continuous improvement’ (i.e., the phenomenon whereby certain skilled performers appear to be capable of increasing their proficiency even though they are already experts; Toner and Moran 2014) among experts is mediated by cognitive (or executive) control in three distinct sporting situations (i.e., in training, during pre-performance routines, and while engaged in on-line skill execution). We conclude by arguing that Sutton et al. Journal of the British Society for Phenomenology, 42, 78–103 (2011) ‘applying intelligence to the reflexes’ (AIR) approach may help to elucidate the process by which expert performers achieve continuous improvement through analytical/mindful behaviour during training and competition
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