Onset of Vortex Shedding and Hysteresis in Flow over Tandem Sharp-Edged Cylinders of Diverse Cross Sections

Numerical simulations are conducted to analyze flow characteristics around two tandem sharp-edged cylinders with cross sections of square (b*1 = 1) for the upstream cylinder and rectangle (b*2) for the downstream cylinder (b* = b/a, where a and b are the sides of cylinders). The study investigates the effects of Reynolds numbers (Re = 30 - 150), cross-sectional aspect ratios of the downstream cylinder (b*2 = 1 - 4), and scaled gap-spacing between cylinders (S* = 1 - 6) on the flow structure, onset of vortex shedding, hysteresis and aerodynamic parameters. The results reveal that increasing b2* suppresses the vortex shedding of the upstream cylinder, depending on S*. The suppression is attributed to the interference effect and the adhesion of the shear layers on the downstream cylinder. Three distinct time-mean flow patterns are identified based on the separation and reattachment of shear layers. The first flow pattern (I) exhibits parallel flow along the side faces of the upstream cylinder, while the separation bubbles associated with reattachment points are formed in flow pattern II on these faces. For pattern III, no reattachment point is observed and the separation bubbles cover the upstream cylinder' side faces. Additionally, two instantaneous flow patterns of extended-body and co-shedding are apperceived within the ranges of examined Re and S*. The behaviors of time-mean and varying forces as well as the vortex shedding frequency are correlated with the flow structures. The onset of vortex shedding and hysteresis dependence are discussed comprehensively. The results show that the critical Reynolds numbers for the onset of vortex shedding decrease from 128 to 50 with S* increasing from 1 to 6 (b*1 = 1 and b*2 = 4). The hysteresis limit is found within the range of 3.5 < S* < 4.5 for flow over two tandem cylinders (b*1 = 1 and b*2 = 4) at Re = 150

Closing the enforcement gap: The international criminal court and national authorities.

The disparity between norms and their enforcement is a recurrent theme in international law. An examination of theory and practice undertaken in the first part of the research reviews national, internationalised/hybrid and international judicial processes. This identifies both normative and structural weakness in the existent system for the enforcement of international criminal law. The second half of the study compares the relationship that is established between the International Criminal Court and national authorities with previous models to determine whether the Rome Statute promises heightened prospects for actual enforcement. The study suggests that the reliance of the ICC on the support of national authorities will result in a persistence of enforcement gaps in the compliance levels of States with their pre-existing duty to prosecute crimes; in the ability of the Court to secure enforcement of its requests and orders; and in the own Court's operational capacity. Evidence suggests, nonetheless, that the ICC is also helping to close enforcement gaps. At the national level, in particular, because of the Court's jurisdictional and admissibility regime, the ICC is altering incentive structures for national authorities and profoundly altering State behaviour. This has been driven primarily by the desire of States to limit admissibility challenges to domestic jurisdiction based on legislative inconsistencies or domestic inaction. The research shows that the successful closing of enforcement gaps will require the close and effective interaction of national and international jurisdictions. For the treaty signed in Rome is not just about a Court, it is about a system; a global system based on national States. Without national authorities, the ICC will be unable to act. But also conversely, without the catalytic presence of the ICC, it is unlikely that national authorities would be willing to act. As such, the ICC Statute acts as both a standard setting instrument and a compliance-inducing mechanism

Critical time of nitrogen application during panicle initiation on the yield of two Malaysia rice cultivars (Oryza sativa L.)

Nitrogen is the most limiting nutrient in rice production. N fertilizer is susceptible to losses when the time of application does not match with period of crop demand. A glasshouse experiment was conducted to determine the critical time of nitrogen fertilizer application at panicle initiation on grain yield of two Malaysian rice cultivars (MR219 and MR232). The experiment consisted of five N treatments applied each at 60 kg ha-1 at 45 (NI), 50 (N2), 55 (N3), 60 (N4) and 65 (N5) days after seeding (DAS) with five replications. Prior to this stage, a total of 75 kg N ha-1 was applied during vegetative growth stage (at 15 and 35 DAS). Plant physiological parameters such as height, SPAD value and LAI showed statistical difference among some treatments. Application of N also resulted in an increase in plant biomass. The results demonstrate that the split application of fertilizer N at PI stage (55 DAS) significantly increased percentage of filled grains, 1000-grain weight and total grain yield. Incorrect timing of N application (65 DAS) at P1 stage, drastically reduced rice yield to approximately 39% for MR2 19 and 17% for MR232. Farmers should be advised to apply N between 50 DAS and 55 DAS, even though application of N at 55 DAS was far better than 50 DAS in terms of yield parameters

Alleviation of soil acidity improves the performance of oil palm progenies planted on an acid Ultisol

Soil acidity is one of the main factors that limit profitable and sustained agricultural production. Oil palm (Elaeis guineensis Jacq.) is mainly planted in acidic soils. In the last years, there has been a stagnated yield and increases in disease incidence and severity worldwide that could be attributed in some extent to soil acidity. This study was conducted to determine the effects of soil acidity alleviation on oil palm seedlings. The effects of ground magnesium limestone or dolomite and magnesium carbonate (0, 1.1, 2.2, 3.3 and 4.4 t ha -1) applied to an Ultisol dominated by kaolinite (pH in water 4.4) were evaluated on selected morphological, physiological and nutritional characteristics of hybrid (Deli dura-AVROS pisifera) and clonal (clone 366) oil palm progenies under nursery conditions for 8 months. Increasing rates of ground magnesium limestone and magnesium carbonate showed a significant effect on improving soil pH and lowering exchangeable aluminium. The hybrid oil palm showed significant either linear or quadratic trends for most of the parameters evaluated, indicating that the best responses for morphological and physiological traits were achieved from 2.5 to 4.23 t ha -1 with ground magnesium limestone and 2.87 to 3.45 t ha -1 with magnesium carbonate. Positive effects of increasing rates of ground magnesium limestone and magnesium carbonate were observed on nitrogen and magnesium uptake. Aluminium concentration in the third frond decreased significantly with increasing ground magnesium limestone rate. A significant reduction of manganese uptake was also observed with increasing rates of both ameliorants. The clonal oil palm progeny exhibited a better performance on un-amended treatment. This may be explained by the significant higher root growth of this progeny. Soil acidity alleviation improved the oil palm seedling growth. These results are important for the oil palm industry and could be applied in the nursery stage as well as extended to the immature stage

Variations in oil palm (Elaeis guineensis Jacq.) progeny response to high aluminium concentrations in solution culture

Aluminium (Al) phytotoxicity is an important soil constraint that limits crop yield. The objectives of this study were to investigate how growth, physiology, nutrient content and organic acid concentration is affected by Al, and to assess the degree of Al tolerance in different oil palm progeny (OPP). Four OPPs [‘A’ (Angola dura × Angola dura), ‘B’ (Nigerian dura × Nigerian dura), ‘C’ (Deli dura × AVROS pisifera) and ‘D’ (Deli dura × Dumpy AVROS pisifera)] were grown in different Al concentrations (0, 100 and 200 μm) in aerated Hoagland solution, pH 4.4, for 80 days. We observed a severe reduction (57.5%) in shoot dry weight, and root tips were reduced by 46.5% in 200 μm Al. In ‘B’ and ‘C’, the majority of macro- and micronutrients in plants were reduced significantly by 200 μm Al, with Mg being lowered by more than 50% in roots and shoots. The 200 μm Al treatment resulted in a 56.50% reduction in total leaf area, a 20% reduction in net photosynthesis and a 17% reduction in SPAD chlorophyll value in the third leaf. Root tips (0–5 mm) showed a significant increase in oxalic acid content with increasing Al concentration (∼5.86-fold); progeny ‘A’ had the highest concentration of oxalic acid. There was a significant interaction between Al concentration × OPP on total leaf number, root volume, lateral root length, Mg and K in root and shoot tissues, and Ca and N in shoots. The OPPs could be ranked in their tolerance to Al as: ‘A’ > ‘D’ > ‘B’ > ‘C’

Aluminium speciation of amended acid tropical soil and its effects on plant root growth

Exchangeable and soluble soil aluminum (Al) is limiting plant growth in many soils worldwide. This study evaluated the effects of increasing rates of dolomite and magnesium carbonate (MgCO3) on Al3+, pH, dissolved organic carbon, cations, anions, and Al speciation on oil palm Deli dura × AVROS pisifera root growth. Dolomite and MgCO3 additions significantly raised linearly soil solution pH, magnesium (Mg2+), nitrate (NO3 −) and chlorine (Cl−) concentrations; exponentially decreased the activity of phytotoxic Al species [aluminum (Al3+), aluminum sulfate (Al2SO4), and aluminum fluoride (AlF3)]; and reduced manganese (Mn) concentration and activity. High activity of those species exponentially reduced root dry weight. Optimum oil palm growth was achieved at: <50 μM monomeric Al, < 30 μM Mn, and <0.20 unit of the ratio Al+Mn to calcium (Ca)+Mg. High activity of Al species and Mn in acidic soil solution cause significant reduction of the root growth. Soil acidity alleviation either with dolomite or MgCO3 mitigates the toxic effect of Al and Mn

Seedbank and Seedling Emergence Characteristics of Weeds in Ricefield Soils of the Muda Granary Area in North-west Peninsular Malaysia

Tlie experiment was conducted in the glasshouse of UPM from March 2003 to June 2004 to determine the soil seedbank in the ricefields ot\u27Muda rice granary area in Peninsular Malaysia. Six soil cores of 5 cm in diameter and 10 cm depth were sampled from each of 24 fields. All samples from each individual field were bulked and placed in plastic trays of 38 x 25 x 10 cm. Soil was moistened as required and emergence of weed seedlings were recorded over period of one year. After one year, remaining seeds were separated, removed and identified. The total seed bank was estimated at 1136.48 million/ha of which 62.35% (708.60 million seedlings ha"1) germinated within 12 months and 37.65% (427.88 million seeds ha"1) remained ungerminated. Total of 20 taxa were recognized. Based on importance value (I.V.) the five most dominant species in terms of emerged seedling were Fimbristylis miliacea, Leplochloa chinensis, LitJwigia hyssopifolia, Cyperus difformii and C. iria. Of the remaining seeds the five dominant species with decreasing trend in ranking were F. miliacea, Scirpus lateriflonis, Monochoria vagina/is, L. hyssopifolia and L. chinensis. Ranking of total seed reserves (seedlings+ remaining seeds) were similar to emerged seedling indicating that emerged seedlings reflect the actual weed flora in the Muda area. Among the dominant species F. miliacea accounted for 58.07% of emerged seedlings, 79.31% of remaining seeds and 66.07% of total seed bank. Total seedling emergence of all species was higher in the first observation in April 2003 and cumulative seedling emergence showed no clear peaks

A statistical model that predicts the length from the left subclavian artery to the celiac axis; towards accurate intra aortic balloon sizing

<p>Abstract</p> <p>Background</p> <p>Ideally the length of the Intraaortic balloon membrane (22-27.5 cm) should match to the distance from the left subclavian artery (LSA) to the celiac axis (CA), (LSA - CA). By being able to estimate this distance, better guidance regarding IABP sizing could be recommended.</p> <p>Methods</p> <p>Internal aortic lengths and demographic values were collected from a series of 40 cadavers during autopsy. External somatometric measurements were also obtained.</p> <p>There were 23 males and 17 females. The mean age was 73.1+/-13.11 years, weight 56.75+/-12.51 kg and the height 166+/-9.81 cm.</p> <p>Results</p> <p>Multiple regression analysis revealed the following predictor variables (R2 > 0.70) for estimating the length from LSA to CA: height (standardized coefficient (SRC) = 0.37, p = 0.004), age (SRC = 0.35, p < 0.001), sex (SRC = 0.21, p = 0.088) and the distance from the jugular notch to trans-pyloric plane (SRC = 0.61, p < 0.001).</p> <p>Recommendations: If LSA-CA < 21.9 cm use 34 cc IABP & if LSA-CA > 26.3 cm use 50 cc IABP. However if LSA-CA = 21.9- 26.3 cm use 40 cc, but be aware that it could be "aortic length-balloon membrane length" mismatching.</p> <p>Conclusions</p> <p>Routinely, IABP size selection is being dictated by the patient's height. Inevitably, this leads to pitfalls. We reported a mathematical model of accurate intraaortic balloon sizing, which is easy to be applied and has a high predictive value.</p

Pesticide free coating for papaya (Carica papaya 'Eksotika II')

Mature green stage (Index 2) papaya (Carica papaya L. ‘Eksotika II’) fruits were treated either with 2.5% calcium chloride infiltration, 0.75% chitosan coating, calcium infiltration at 2.5% then subsequently chitosan coating at 0.75% or with distilled water as the control. The fruits were then stored at 13±1°C for up to five weeks. Calcium infiltration was effective in maintaining the firmness and weight loss of the fruits. Firmness was 2.7 fold higher than the control and water loss was about 3% less. However, the chitosan coating had less effect on maintaining firmness (only 1.7 fold higher firmness) but had more effect in preventing weight loss resulting in 5.6% less weight loss. The chitosan coating treatment markedly slowed the ripening of papaya as shown by their reduced weight loss, delayed changes in their external colour (which is normally closely correlated with the internal colour) and other quality aspects. However, when calcium infiltration was combined with chitosan coating, this treatment further extended the storage life up to five weeks with better retention of fruits firmness and water loss control compared to the single treatments