FACTORS AFFECTING THE THICKNESS OF REPLACEMENT LAYER ON MEDIUM CLAY

Soil replacement is a common technique that can be used to increase the soil bearing capacity and reduce the expected settlement. The thickness of replacement layer depends on many factors such as: the applied stress, original soil properties, material of replacement layer and the cost of foundation works. However, until now the practical thickness of replacement is usually selected based on soil experts’ experience. This study proposed an optimization model to assist geotechnical engineers in predicting the optimum thickness and material type of replacement layer that satisfy the main design requirements, i.e. bearing capacity, consolidation settlement and cost considerations at the same time. The Evolutionary solving method that uses a variety of genetic algorithm and local search methods was used to solve the research problem. Furthermore, the effect of the thickness and properties of clay layer and the depth of ground water table on determining optimum type and thickness of replacement soil were investigated. The study evaluated the relationship between the replacement layer thickness and the total direct cost of foundation works and found that, the notion of increasing replacement thickness to decrease cost limitlessly was not viable and an optimal thickness was usually achieved.

QUESTIONS ON OPTIMUM DEVELOPMENT OF COMPLEX FOR MULTI-POINT CONTROL AND EVALUATION OF CONTAMINATION OF WATER BASINS POLLUTED BY WASTE WATER OF MINING AND PROCESSING PLANTS

The paper is devoted to questions on optimum development of complex for control and evaluation of contamination of water basins used for collection of industrial waste water. The purpose of the paper is development of scientific-methodical basics for development of measuring system for control and evaluation of contamination of natural water basins with heavy metals using method of attenuation of irradiation of dissolved organic matters excited by external irradiation. The task on optimization of operational regime of measuring complex for control and evaluation of contamination of natural water basins by waste water of large scale point type polluter of environment with heavy metals. The known model of Shtern-Volmer is used as a basis which assumes non-linear relationship between formed complex and fluorescent irradiations attenuation degree. It is noted that potential possibilities of Shtern-Volmers model are used not fully till now. So that in known researches the water objects polluted by several same sources are mainly researched. It is shown that Shtern-Volmer model is also applicable for analysis and estimation of pollution of water basins by single strong polluter that is mining and processing plants. For analysis the suggested special parameter, inversely proportional to concentration of heavy metals in water is used. Integration of this parameter on all possible values of heavy metals concentration and imposition of special limitation condition on the searched for function of dependence of attenuated part of fluorescent irradiation on maximum concentration of heavy metals make it possible to formulate and solve the task on searching of optimum type of this function providing for the optimum regime of operation of the complex.

SIFAT DAN KARAKTERISTIK CAMPURAN BETON MENGGUNAKAN BATU PECAH DAN BATU GULI DARI SUNGAI BINJAI

Concrete is a construction material consisting of a mixture of cement, aggregate, water and with or without admixture if needed. Coarse aggregate and fine aggregate serve as the main filler of concrete as well as reinforcement, while the cement and water mixtured serves as a binder between materials. To find out and study the behavior of each of these concrete constituents, it is necessary to know the characteristics of the materials made as constituents of the concrete. This study was conducted with the aim of comparing the most optimum type of coarse aggregate used and the comparison of the use of cement for coarse aggregate of crushed stone and coarse aggregate of gully originating from North Sumatera area, namely from the Wampu River in Binjai City as a concrete mixture to see its effect on compressive strength of concrete at the same concrete characteristics namely f’c 25 MPa. The results of the normal concrete mix design are obtained by using coarse aggregate of crushed stone and coarse aggregate of boulder in different amounts of cement. The coarse aggregate of crushed stone requires more cement with the amount of cement 411.1 kg/m3 than the coarse aggregate of gum with the amount of cement 388.9 kg/cm3.

The optimum model determination of porous barriers in high-speed tracks

In the railway industry, safety is an essential factor that has been modified by all societies and railroad managers. Against the background of increasing speed of rolling stock, risk factors such as cross wind and train stability have received more extensive attention. In this study, the porous wind barriers that are widely used in this industry have been surveyed. Also, to decrease the harmful effects of crosswind, the work attempts to find an optimum porous barrier design. This numerical simulation was based on a modern computational fluid dynamic in microscopic space model called the Lattice Boltzmann Method. Also, to find the optimum type of barrier design, the Multi-Objective Genetic Algorithm had been used. Two aspects of barrier design, including the porosity levels and distance between barriers, have been studied and, finally, a candidate design proposed for the barriers. It was found that porousity levels up to 15% have a positive effect in reducing the lift force coefficient, but beyond that it has a negative effect. On the other hand, increasing the porosity level leads to a decrease in the drag coefficient. The velocity vectors, velocity counter, vorticity, and turbulence intensity of the flow field around the model plotted for the candidate barrier.

Questions on Technological Optimization of Centralized Flaring of Associated Hydrocarbon Gas from Sources with Different Methane Concentration

The method of technological optimization of associated hydrocarbon gas centralized flaring from sources with different methane concentration is suggested. The technological scheme of centralized flaring is composed. The relevant optimization task is formulated and solved solution of which make it possible to obtain the optimum type interrelation between methane concentration in associated gas and wind speed. As a result of carried out optimization the optimum order for functioning of composed technological scheme of centralized flaring of associated gas is recommended.

Reduksi Torium Pada Limbah Cair Pengolahan Monasit Menggunakan Resin Penukar Anion

ABSTRAK Dampak dari pemisahan logam tanah jarang pada monasit adalah limbah cair yang mengandung unsur radioaktif torium yang berbahaya bagi lingkungan dan makhluk hidup. Metode standar dalam pemisahan torium dari limbah cair adalah dengan menggunakan resin penukar anion. Penelitian ini bertujuan untuk mengetahui jenis resin penukar anion, massa resin, dan waktu kontak yang optimum untuk menurunkan kadar torium dalam limbah cair monasit. Hasil menunjukkan bahwa laju penukaran optimum terjadi pada resin Amberlite IRA402 dengan waktu kontak 60 menit dan massa 1 gram yaitu sebesar 57,7%. Sementara itu, pada resin Tulsion A23, laju penukaran optimum sebesar 50,7% terjadi pada waktu kontak 50 menit dan massa resin 1 gram. Uji statistik menunjukkan tidak ada perbedaan nyata pada variasi jenis resin dan waktu kontak yang menunjukkan nilai signifikan >0,05. Pada waktu yang sama, terdapat perbedaan nyata pada variasi massa resin dengan hasil nilai signifikan <0,05. Uji Duncan menyatakan massa resin kecil (0,25 dan 0,5 gram) cocok untuk Tulsion A23 dan massa resin besar (0,75 dan1 gram) cocok untuk resin Amberlite IRA402.ABSTRACT The effect of separating rare earths from monazite is wastewater containing the radioactive element thorium which is harmful to the environment and living things. A standard method of separating thorium from wastewater is with anion-exchange resin. This study determines the optimum type of anion-exchange resin, resin weight, and contact time to reduce thorium levels in monazite wastewater. The results showed that the optimum exchange rate that occurred in Amberlite IRA402 resin is 57.7%, at 60 minutes and 1 gram. Meanwhile, the optimum exchange rate for Tulsion A23 resin is 50.7%, at 50 minutes and 1 gram. The statistical test showed that there was no significant difference in the resin type and contact time variation, which showed a considerable value >0.05. At the same time there was a substantial difference in resin mass variation with a significant value <0.05. The Duncan test stated that lighter resin masses (0.25 and 0.5 gram) are suitable for Tulsion A23 and heavier resin masses (0.75 and 1 gram) are ideal for Amberlite IRA402.

Macroevolutionary patterns of body plan canalization in euarthropods

Reconstructing patterns of macroevolution has become a central endeavor in paleobiology, because it offers insight into evolutionary models shaping the history of life. As the most diverse and abundant animals since the Cambrian period, arthropods provide copious data to elucidate the emergence of body plans in metazoan lineages. However, information provided by fossils on the tempo and mode of this phenomenon has lacked a recent synthesis. Here, I investigate macroevolutionary patterns of morphological evolution in Euarthropoda using a combined extinct and extant dataset optimized for multivariate analyses. Overall ordination patterns between the main morphogroups are consistent with another, independently coded, extant-only dataset providing molecular and morphological rates of evolution. Based on a “deep split” phylogenetic framework, total-group Mandibulata and Arachnomorpha emerge as directional morphoanatomical lineages, with basal fossil morphogroups showing heterogeneously spread-out occupations of the morphospace. In addition to a more homogeneous morphological variation, new morphogroups arose by successive reductions of translation distances; this pattern was interrupted only by terrestrialization events and the origin of pancrustaceans. A displaced optimum type of model is proposed to explain the fast assembly of canalized body plans during the Cambrian, with basal fossil morphogroups fitting intermediate fitness peaks in a moving adaptive landscape. Given time constraints imposed by the paleontological evidence, and owing to the interplay between canalization and modularity, as well as a decoupling between molecular and morphological rates, the rise of euarthropods would support the view that the swiftness of the Cambrian explosion was mostly associated with the buildup of genetic regulatory networks.

Energy-Scape Web-Based Application is an Effective Tool to Overcome the Basic Knowledge of Architects Toward Renewable Energy Properties

In last few years, research on renewables were shifted from integrating renewable energy (RE) with buildings into integrating renewable energy (RE) within urban environment due to the large occupies of urban areas in comparing to the building foot print. Urban areas such as urban landscape areas have a great potential in generating huge amount of energy that could satisfy the needs of urban neighbor-hoods. The presented research identify the properties of a new elements called Energy-scape elements (ESE) that integrates RE devices with urban landscape el-ements. This research focuses on analyzing the efficiency of web-based applica-tion called “Energy-scape software” (ESS) and compare its efficiency with Ener-gy-scape database (ESD) through a qualitative method. The research concludes that Energy-scape software (ESS) application is an effective tool for implement-ing Energy-scape elements (ESE) and it overcome the basic knowledge of archi-tects and landscape designers toward renewable properties. Moreover, it identi-fies the optimum type and location of Energy-scape elements (ESE) within a spe-cific project, and it calculates the impact of using Energy-scape elements (ESE) in term of energy-savings.

Pengaruh penambahan Ion Logam Natrium, Kalium, Magnesium, Kalsium pada biokonversi tepung jagung (Zea Mays L.) oleh Ragi Endomycopsis Fibuligera menjadi Senyawa Prebiotik

In this study made prebiotic from bioconversion of corn flour (Zea mays L.) by yeast Endomycopsis fibuligera as an alternative substitute for antibiotics. In this study, the addition of Na+, K+, Ca2+, and Mg2+ ions aimed to determine the optimum type and concentration of metal in prebiotic and testing the effect of prebiotic compounds produced on broiler weight gain. The analysis carried out included: reducing sugars, α-amylase and glucoamylase enzyme activity, protein content and cell biomass. To determine the existence of a significant effect, the analysis was carried out on broiler body weight given prebiotic compounds which were added to optimum metal ions and which were given prebiotic compounds without the addition of metal ions. The results showed that the addition of optimum metal ions was obtained on Ca2+ ions with a concentration of 0.25%, where the reducing sugar content of 0.600 mg / mL, the activity of the enzyme α-amylase and glucoamylase 0.519 and 0.287 units / mL, protein content 2.724 mg / mL, cell biomass 10.8933 mg / mL, from observations and statistical tests carried out by giving prebotic compounds by adding metal ions and giving prebiotic compounds without adding metal ions influence broiler weight gain with an average weight difference of 261 grams or 15% on day 30.

Questions on utilization of different height balloon sources of optical radiation for calibration of network of ground microtelescopes for tracking of orbital satellites

One of ways to increase accuracy of ground tracking of orbital satellites is high accuracy calibration of network of microtelescopes used for this purpose. To attain high accuracy utilization of stable laser sources of radiation is most expedient. To install such sources the balloon platforms mounted at some height are practiced. But utilization of only one fixed height of all sources for calibration could lead to insufficient value of signal/noise ratio due to unpredictable atmospheric events. At the same time utilization of sources with different spectral characteristics can complicate the required methodic for analysis. Authors suggest utilization of same type lasers and carrying out of calibration using platforms installed at different heights. Nonapparent function of dependence of laser beams divergence on height of balloon installation is considered for analysis. Some integrated limitation is imposed on this function. It is assumed that number of microtelescopes receiving optical radiation of one source linearly depends on height of the source. It is required to find out the optimum type of suggested non-apparent function upon which target functional composed as sum of all calibration signals could reach maximum. Utilization of such property of target functional for checking up of carried out calibration procedure is suggested. Providing for the required type of suggested non-apparent function is technically resolvable task because the beam divergence is controlled parameter and height of platform can be measured with sufficient accuracy.