Tidal Turbine Generators

Recently, tidal stream turbines have become a preferable mode of harvesting tidal energy. The main issue for low utilization of tidal energy is the high levelized cost of energy (LCoE) from tidal stream turbines. A major reason for this is the high operation and maintenance costs for submerged installations. A possible way of minimizing the LCoE and improving the availability is to use a flooded (or a wetgap) generator rather than a conventional airgap generator. Inside flooded generators, the gap between the stator and rotor is filled with the seawater. This architecture has the potential to improve cooling and reduce reliance on ancillary systems (e.g., bilge system), thereby improving reliability. The chapter begins with a brief description of the generator systems used in current tidal stream turbines. The focus of the chapter is, however, to give a basic insight into the design aspects of the flooded generators, and compares it with the currently used sealed airgap generators in tidal turbine systems

An intact plant assay for estimating nitrogenase activity (C2H2 reduction) of sorghum and millet plants grown in pots

A non destructive assay for estimating nitrogenase activity (C2H2 reduction) of pot-grown sorghum and millet is described. Plants with intact shoots sustained more activity than plants whose tops were removed prior to the assay. with this technique individual plants can be assayed several times during their life cycle. C2H2 reduction was linear up to 16 h of incubation. More rapid diffusion of C2H2 was achieved by injection into the bottom of the pot than into the top of the pot. The equilibration of injected C2H2 in the gas phase of pots filled with sand and sand:FYM media was complete within 1 h. Significantly greater nitrogenase activity and growth of sorghum and millet occurred when plants were grown in a mixture of sand and farmyard manure (FYM) than when grown in vermiculite, soil or sand + soil medium. Nitrogenase activity and plant growth were greater in a mixture of sand with 2 and 3% FYM than with 0.5 and 1% FYM. Activity was higher when plants were incubated at 33°C and 40°C than at 27°C, and increased with increasing soil moisture. There were significant differences among 15 sorghum cultivars screened for associated nitrogenase activity

Reduced expression of PML predisposes to Paget's disease of bone by increasing osteoclast differentiation and bone resorption

Paget's disease of bone (PDB) is characterized by focal increases in bone remodelling. Genome-wide association studies identified a susceptibility locus for PDB tagged by rs5742915, which is located within the PML gene. Here, we have assessed the candidacy of PML as the predisposing gene for PDB at this locus. We found that the PDB-risk allele of rs5742915 was associated with lower PML expression and that PML expression in blood cells from individuals with PDB was lower than in controls. The differentiation, survival and resorptive activity of osteoclasts prepared from Pml-/- mice was increased compared with wild type. Furthermore, the inhibitory effect of IFN-γ on osteoclast formation from Pml-/- was significantly blunted compared with wild type. Bone nodule formation was also increased in osteoblasts from Pml-/- mice when compared with wild type. Although microCT analysis of trabecular bone showed no differences between Pml-/- mice and wild type, bone histomorphometry showed that Pml-/- mice had high bone turnover with increased indices of bone resorption and increased mineral apposition rate. These data indicate that reduced expression of PML predisposes an individual to PDB and identify PML as a novel regulator of bone metabolism. This article has an associated First Person interview with the first author of the paper

HbA1cmeasurement and relationship to incident stroke

Aims: To determine the proportion of people with diabetes who have Hb A1c measured, what proportion achieve an HbA1c level of < 58 mmol/mol (7.5%), the frequency of testing and if there was any change in HbA1c level in the year before and the year after an incident stroke. Methods: This study used the Secure Anonymised Information Linkage (SAIL) databank, which stores hospital data for the whole of Wales and ~65% of Welsh general practice records, to identify cases of stroke in patients with diabetes between 2000 and 2010. These were matched against patients with diabetes but without stroke disease. We assessed the frequency of HbA1c testing and change in HbA1c in the first year after stroke. Estimation was made of the proportion of patients achieving an HbA1c measurement ≤ 58 mmol/mol (7.5%). Results: There were 1741 patients with diabetes and stroke. Of these, 1173 (67.4%) had their HbA1c checked before their stroke and 1137 (65.3%) after their stroke. In the control group of 16 838 patients with diabetes but no stroke, 8413 (49.9%) and 9288 (55.1%) had their HbA1c checked before and after the case-matched stroke date, respectively. In patients with diabetes and stroke, HbA1c fell from 7.7 to 7.3% after their stroke ( P<0.001). Before the study, 55.0% of patients with stroke had an HbA1c ≥58 mmol/mol compared with 65.2% of control patients, these figures were 62.5% and 65.3% after the stroke. Conclusions: The frequency of diabetes testing was higher in patients who had experienced a stroke before and after their incident stroke compared with control patients but did not increase after their stroke. Glucose control improved significantly in the year after a stroke

On-Farm Nutrient Balance Studies in the Dry Zone of Myanmar

On-farm experiments to study soil fertility depletion—one of the biophysical factors limiting crop production—were conducted in six villages of central Myanmar during 1997 to 1999. Systematic socioeconomic surveys and analysis of socioeconomic and crop production factors aided the selection of farmers. Topsoil mineral nitrogen content at the start of the cropping season was high (10–25 mg N kg−1). Available phosphorous was around the threshold level for most crops, but exchangeable potassium was low. The predominant continuous cropping system of sole groundnut was on average positive for P (0.24 kg ha−1 y−1) and K (7.05 kg ha−1 y−1) and negative for N (−32.4 kg ha−1 y−1). A negative balance for N in the groundnut/pigeonpea (−58 kg ha−1 y−1) and mung bean/pigeonpea (−56 kg ha−1 y−1) intercropping systems was noted. The nutrient balances were positive in early sesame—late sesame (29 kg N ha−1 y−1, 8 kg P ha−1 y−1, 33 kg K ha−1 y−1) and early sesame/pigeonpea (8 kg N ha−1 y−1, 15 kg P h−1 y−1, 44 kg K ha−1 y−1) production systems while sole sorghum system resulted in positive balance for N (23.8 kg ha−1 y−1) and negative balance for K (−3.8 kg ha−1 y−1)

Opportunities to Increase Water Productivity in Agriculture with Special Reference to Africa and South Asia. Stockholm Environment Institute, Project Report - 2009

Our primary goal in this paper is to describe how improvements in water and land management can increase the productivity of water in agriculture, which, broadly defined, means getting more value or benefit from the volume of water used to produce crops, fish, forests and livestock (Kijne et al., 2003). We begin by reviewing water scarcity and water productivity at the global level. We then describe ten Key Messages regarding efforts to improve water productivity in agriculture, with emphasis on Africa and South Asia

Weed management role in increasing crop yield and doubling rice farmers’ income in India - An analysis

India produces 24.8% of world rice by standing first in area (43.9 million ha) and second in production (106.5 million tons) globally. Rice plays vital role in Indian food security as it is staple food for two thirds of Indians supplying 33% of food energy.Rice productivity and production are to be increased to meet the demands of increasing population. Indian rice farmers are constrained by escalating farming cost and depleting income. The rice productivity in India is low (2.4 t/ ha) due to wide range of environmental conditions and ways it is grown and the biological and physical constraints that prevail. Among biological constraints weeds are major causing yield losses of 10 to 100% depending on method of rice establishment, associated weeds, cultural practices adopted, environmental and other associated factors (Rao and Nagamani 2010, Rao et al. 2015). Thus any effort involving improvement in food grain production to meet current and future food demands and double the farmers’ income must involve rice and weed management. The objective of the present analysis is to assess weed management role in attaining higher crop production and to double the income of rice farmers in India

ADHD presenting as recurrent epistaxis: a case report

Epistaxis is an important otorhinolaryngological emergency, which usually has an apparent etiology, frequently local trauma in children. Here we present a case report wherein the epistaxis was recalcitrant, and proved to have a psychiatric disorder as an underlying basis. The child was diagnosed with Attention Deficit/Hyperactivity Disorder, hyperactive type, which led to trauma to nasal mucosa due to frequent and uncontrolled nose picking. Treatment with atomoxetine controlled the patient's symptoms and led to a remission of epistaxis