Papers by Keyword: Sedimentation

Abstract: Novel reactive technique has been employed in synthesis of 7075 Al matrix composites, and effect of TiB₂ particles on sedimentation and microstructure of 7075 Al Alloy in near liquidus was investigated. Researchers have shown that 4.5%TiB₂/7075 composites had the smallest grains and the minimum liquidus and solidus temperatures in 7075 Al matrix composites. 4.5%TiB₂/7075 composites holding for 21 hours appeared stratification phenomenon, the globular grains were 61μm and 214μm, 250μm and 283μm with the increase of holding time respectively. The microstructures evolution of TiB₂ /7075 composites holding for different time at 635°C was a two-stage mechanism that the globular grains was formed firstly and secondly sedimentation and layering were began after a period of time of Ostwald ripening. The globular grain continued to increase during the settling process.

Abstract: It is proposed to use light pressure forces to form nanostructures in a transparent nanosuspension. We have discussed the theoretical model of formation of crystal from nanoparticles on a bottom of cuvette by using the laser effect in liquid. It was received the steady-state solution of one-dimensional task of the light induced mass transfer as depending on intensity of laser beam.

Abstract: Coastal dynamics and stability becomes the distinctive characteristics in northern coastal at Bangkalan. Coastal morphology are dominated by beach sloping, substrate, and hydrooceanographics factors. One of the indicators was suspended sediment fluctuations. This study aims to know the shoreline changes use indicator suspended sediment and image overlay analysis. The research was conducted in April 2015 in the northern and western coastal region of Bangkalan. The main material in this study was suspended sediment samples and the substrates were taken at 28 points, and the image data of Landsat TM 1994 and 2014. Analysis of sediment suspension is using gravimetric method and substrate analysis using ASTM method. Data analyzed at the Laboratory of Marine Science, Trunojoyo University. The result shows in the northern and western coast at Bangkalan regency is dominated by sand and mud as well as a mixture both of them, the coastal waters are dynamic. The distribution of suspended sediment are relatively diverse in all locations with a range of 25-190 mg/L and can be used as an early indication of shoreline changes as a result of erosion and sedimentation. Landsat TM image analysis using 1994-2014 showed almost all areas in the northern and western coastal at Bangkalan regency are both abrasion and sedimentation.

Abstract: The development of the power sector is required to consider not only the environmental factors but also the economic and security factors. Management of electrical energy in Indonesia faced a major problem because of the shortage of energy production demand continues to increase 7.1% annually and the energy production is also very depending on fossil energy sources which dominate 85% of the total power generation. This condition will lead to increasing gas emissions in greenhouse by 78.01 million tons per year. Evaluation of existing plants with a dynamic model of the system will be a consideration for the sustainability of hydropower operation. The simulation results of the Sutami HEPP show more economical and more eco-friendly than fossil energy-based power plant. It is important to build and maintain a HEPP in Indonesia today, due to the potential based on these considerations, the capacity and the reduction of greenhouse gas emissions.

Abstract: A variety of industrial minerals, such as kaolinite, feldspars, and etc., have been used as solid raw materials in the geopolymerization technology. The illite-containing raw material in this study was obtained by the use of sedimentation method. Clay and dust fractions was subjected to the treatment with NaOH alkaline solution and afterwards treated at different temperatures. Results obtained by X-ray diffraction, Scanning electron microscopy, nitrogen adsorption method confirmed the usability of Liepas deposit homogenized gray and red clays for possible realization of geopolymer method.

Abstract: The study of the sedimentation of particulate materials is of interest in several industrial processes, such as in the design and optimization of operating conditions of thickeners and during the operational stages of drilling oil wells. In this context, this work aims to study the sedimentation of particles in viscous Newtonian fluids. For the tests, aqueous solutions of glycerol were used in the volumetric concentration of 80% and 92%. The suspensions were prepared using sand with the size range of 150-212 μm. The settling of particles was studied by using a nondestructive technique based upon the measurement of gamma-ray attenuation for achieving the local concentration of solids. The results showed that the sedimentation velocity of particles was changed significantly with increasing fluid viscosity. Moreover, the dynamic behavior of the particles settling in both glycerol solutions showed similar, with two regions of varying concentration of solids very defined: one in which the solids concentration remained constant until the transition from descending clarified interface; and the other in which the concentration remained constant until the formation of sediment.

Abstract: The control action of palaeogeomorphology to sedimentation is a hotspot of research in recent years, especially in the analysis of oil and gas basin. This paper is based on the history and present of palaeogeomorphology research and summarizes the recovery method of palaeogeomorphology. In the work of recover palaeogeomorphology, recovery of denuded thickness is one of the most important steps. Principles and the applicability of each method are analyzed, such as depositional rate, vitrinite reflectance and so on.

Abstract: Nanofluids are colloidal suspensions of nanoparticles in a base fluid which are mainly used as modern heat transfer fluids. The applications of nanofluids include electronic cooling systems, direct absorption solar collectors, magnetic smart fluids and in biomedical treatments. The success of these applications depends on stability of nanofluid. In the present work TiO₂ nanofluids have been synthesized by two step technique .The nanoparticle of TiO₂ are prepared by sol gel and characterized by XRD, SEM and UV. The sedimentation of prepared nanofluid is observed by the gravity sedimentation method and transmitted intensity is recorded by a photo detector. A profile between the transmitted intensity and distance of nanofluid from laser source is obtained which shows the potential application of nanofluid as optical sensors for detecting stability of nanofluid.

Abstract: This paper presents the general features about the stability of emulsions and modeling particle sedimentation process at the flow of water-oil emulsion (WOE) through a horizontal pipe. Are presented a plant and the methodology for determining the stability of WOE, and finally the experimental results that validates the theoretical equations and particle sedimentation model along the pipeline.

Abstract: Located at the exit of the last gorge of the middle reaches of the Yellow River, the Xiaolangdi Multipurpose Dam Project occupies a critical position in controlling both runoff and sediment of the River. typical tributary Zhenshui is the biggest tributary of Xiaolangdi Reservoir and its original storage capacity is 1.767 billion m³.This paper shows the process of the longitudinal profile of tributary Zhenshui,which faces the serious sediment bar growth at its mouth. Discussion is processed to show the possibility.