EROSION RATE OF RESERVOIR DEPOSIT AS REVEALED BY LABORATORY EXPERIMENT

The construction of dams and reservoirs in a river can give significant impacts on its flow of water and sediment, and can cause long-term morphological changes on the river. Reservoir sedimentation can reduce a reservoir’s effective flood control volume, and in some severe cases can cause overtopping during floods. Sediment deposition against a dam can reduce its stability, and affect the operation of low-level outlet works, gates, and valves. The abrasive action of sediment particles can roughen the surface of release facilities and can cause cavitations and vibration. Sedimentation can also affect a reservoir’s water quality, and reduce its flood control, water supply, hydropower, and recreation benefits. Consequently, taking sedimentation into consideration not only in the planning and design, but also in the operation and maintenance of a dam and reservoir is important. Keywords: Erosion rate, reservoir deposit, shear stress

A site-specific standard for comparing dynamic solar ultraviolet protection characteristics of established tree canopies

A standardised procedure for making fair and comparable assessments of the ultraviolet protection of an established tree canopy that takes into account canopy movement and the changing position of the sun is presented for use by government, planning, and environmental health authorities. The technique utilises video image capture and replaces the need for measurement by ultraviolet radiometers for surveying shade quality characteristics of trees growing in public parks, playgrounds and urban settings. The technique improves upon tree shade assessments that may be based upon single measurements of the ultraviolet irradiance observed from a fixed point of view. The presented technique demonstrates how intelligent shade audits can be conducted without the need for specialist equipment, enabling the calculation of the Shade Protection Index (SPI) and Ultraviolet Protection Factor (UPF) for any discreet time interval and over a full calendar year

Extending the scope of microscopic solvability: Combination of the Kruskal-Segur method with Zauderer decomposition

Successful applications of the Kruskal-Segur approach to interfacial pattern formation have remained limited due to the necessity of an integral formulation of the problem. This excludes nonlinear bulk equations, rendering convection intractable. Combining the method with Zauderer's asymptotic decomposition scheme, we are able to strongly extend its scope of applicability and solve selection problems based on free boundary formulations in terms of partial differential equations alone. To demonstrate the technique, we give the first analytic solution of the problem of velocity selection for dendritic growth in a forced potential flow.Comment: Submitted to Europhys. Letters, No figures, 5 page

Traitements d'effluents issus de l'industrie de la pêche par un procédé de coagulation/floculation

La présente étude porte sur le traitement physico-chimique d'un effluent industriel chargé d'encre de seiche issu de l'industrie de conditionnement des produits de la pêche. Différentes combinaisons de coagulant -floculant ont été étudiées. Le sulfate d'aluminium (SA), divers polyélectrolytes et certains adjuvants pulvérulents ont été utilisés. L'efficacité du traitement par coagulation-floculation a été analysée en suivant l'évolution de la turbidité et de la DCO résiduelle du surnageant.Les résultats de cette étude ont révélé qu'à pH 6-7, l'addition de SA à une concentration supérieure à 1000 mg.l-1 entraîne la coagulation des particules d'encre de seiche. L'addition d'un polyélectrolyte en association avec le SA permet de réduire la concentration requise en SA à environ 300 mg.l-1, tout en améliorant l'efficacité du processus de coagulation-floculation. Le recours à un adjuvant pulvérulent en combinaison avec le SA et un polyélectrolyte accroît notablement les performances du traitement et permet d'obtenir un effluent ayant une turbidité résiduelle de 7 NTU.The aim of this work was to compare the efficiency of a coagulation-flocculation process using different systems individually or in combination. The waste water used was an industrial cuttlefish effluent principally composed of colloidal particles from the cuttlefish. The initial turbidity and chemical oxygen demand were approximately 700 NTU and 22,000 mg×L-1 respectively. Two parameters were used to assess the process efficiency: the residual turbidity and the chemical oxygen demand (COD) of the supernatant.Three systems were investigated: aluminium sulphate (SA), polyelectrolytes and a ternary combination of SA-polyelectrolyte and colloidal microparticle adjuvant. Results demonstrated that at pH 6-7, SA caused some coagulation of the suspension, but the dosage required (about 1000 mg×L-1) far exceeded those conventionally used in water treatment. As a consequence, an appreciable amount of SA, which was above the authorised limits, remained in the supernatant. Indeed, adsorption isotherm measurements revealed that at pH 6.5-7 the residual proportion of SA attained was about 20%. The addition of polyelectrolytes in combination with SA allowed reduction of the SA dosage to 150 mg×L-1. Amongst the polymers tested, the cationic polymer was the most efficient. The ability to bring about flocculation was positively related to the molecular weight, which is in agreement with a bridging flocculation mechanism. Starch, a natural, low-cost polymer was also an efficient flocculent even though it is a non-charged polymer. The ability of starch to bring about a flocculation action was explained by its relatively low solubility, which leads to some aggregation of macromolecular chains that act as anchoring sites for the coagulated ink particles. With this system, a double treatment in the presence of 150 mg×L-1 SA and 25 mg×L-1 polydiallyldimethylammonium chloride (PDMAC) or starch lead to a supernatant with a turbidity and COD of 150 NTU and 5500 mg×L-1 respectively.The third part of our study was concerned with the effect of the addition of an insoluble microparticle adjuvant in combination with SA and polyelectrolytes. Different components were investigated, but among them only colloidal silica and MgO bring about a significant enhancement of the flocculation process. This effect was explained by a bridging mechanism in which the adjuvant microparticles act as sites that favour the anchoring of the coagulated ink particles. Using a triple treatment in the presence of 150 mg×L-1 SA, 25 mg×L-1 PDMAC and 0.75 g×L-1 MgO removed about 95 % of the ink particles. The supernatant obtained was characterised by a low turbidity value (about 7 NTU) and a COD value about 2000 mg×L-1

Analisis Pertumbuhan Ekonomi dan Kemiskinan di Indonesia

Economic growth and poverty is an important indicator to see the success of a country's development. This study aims to determine and analyze the two-way influence between economic growth and poverty in Indonesia: (1) The effect of unemployment, poverty, investments and economic growth. (2) The effect of investment, life expectancy, literacy, and length of education, and economic growth on poverty.This study uses panel data or pooled time-series crossection using time series data from the years 2005-2009, and the crossection is that there are 33 provinces in Indonesia. The method used is descriptive and econometric analysis using a model of simultaneous equations (simultaneous equations models) with two-stage least squares method (Two-Stage Least Square 2SLS) using Indirect Least Square (ILS). The results showed that there is a two-way interplay between economic growth and poverty. Significant effect on economic growth in poverty reduction, especially in rural areas there are many pockets of poverty. the opposite of poverty is also a significant effect on economic growth. Through improved access to capital, quality of education (literacy and increased length of education) and health (increased life expectancy) of the poor can increase their productivity in the attempt during the period 2000-2009. The unemployment rate, and significant investment on economic growth. Furthermore, investments in domestic and foreign investments, life expectancy, literacy and school longer a significant effect on the number of poor. Based on these findings the policy the government should do is spur economic growth through the expansion of investment especially in agriculture (agribusiness and agro-industries) in rural areas where many poor people depend. Recommended to the government in order to spur economic growth in urban areas in order to prioritize employment in which informal sector in general the poor do business. Whereas in rural areas run projects that are capital - intensive investment to open up employment opportunities, especially in the agricultural sector. Furthermore, it also advised the government both at central and regional levels through the state budget and regional budgets in order to further enhance the percentage of budget allocation on health and education to improve the quality of human resources of Indonesia's population. In order to improve the quality of human resources in Indonesia suggested that the government should also continue to run the program compulsory 9 (nine) years, and scholarships for children from poor families to achieve to improve the quality of their children

Model Makroekonomi Tahun 2000 - Tahun 2010

ABSRACT This study aims to analyze and find out (1) the influence of consumption, investment, government spending, exports and imports to GDP in Indonesia, (2) the influence of disposable income and deposit rates on consumption in Indonesia, (3) the influence of interest rates on investment, GDP , and the rate of investment in Indonesia, (4) the influence of exchange rate and U.S. GDP to exports in Indonesia, and (5) the influence of exchange rate and GDP to imports in Indonesia. This study uses a macroeconomic model developed by Keynes with a simultaneous equation model analysis with Two Stages Least Squared method (TSLS) from the first quarter of 2000 - the first quarter of 2010. The study concluded that (1) consumption, investment, government spending, exports and imports significantly affect the GDP in Indonesia. (2) have a significant disposable income on consumption in Indonesia. (3) the investment rate, GDP, and significantly influence the rate of investment in Indonesia. (4) exchange rate and the GDP of the United States have a significant effect on exports in Indonesia, and (5) exchange rate and GDP have a significant effect on imports in Indonesia