Papers by Keyword: Distribution

Abstract: Over time, the increase in population is directly proportional to the increase in water demand, this will cause problems in the future, namely the water crisis. In the Malikussaleh University medical building, clean water distribution planning is the main focus of the research. With the increase in the number of students from year to year, the demand for water is also increasing. To find out how much water is needed for each user of the building. From the results of the calculation analysis, the total water demand per day is 2,910 liters / day. The maximum water demand in the building occurs in period II (08.00-16.00) WIB which is 2,328 liters/8 hours or 0.000080833m3 /s. In this study, it is assisted by the EPANET 2.0 software program, from the results of the EPANET 2.0 software simulation, it shows that the distribution of water flowing through the pipe from the tank to the point of discharge is normal, there are some minor water losses at the intersection / branching of the pipe caused by the friction of water in the pipe, turns and valves. The highest water velocity occurs from the pump point to the tank which is 4.65 m/s.

Abstract: Crystal size disribution is a parameter used to indicate the quality of sugar crystals obtained from the crystallization process. The better the crystal size distribution, the better the quality of the sugar crystals produced. The good quality of sugar crystals has an impact on the easier separation process that will occur in the centrifugal machine and can reduce sugar loss both in the centrifugal machine and in the sugar grader. The purpose of this study is to determine the effect of the number of sugar seeds, the quality of the mother liquor and the length of time used in the crystallization process on the quality of white sugar crystals produced in the Batch Vacuum Pan and to obtain the best interaction from several levels used for each factor, which can be used as a reference for producing sugar products that have crystal size distribution values according to the desired standard. Each treatment was carried out twice. Observations were made on material characteristics (brix, pol, and purity) and product sugar characteristics (average crystal size and coefficient of variation of crystal size). Measurement of the characteristics of sugar using a sieving (granulometer) which is then calculated using the ICUMSA GS2-37 method. The influence of factor’s main effect and interaction were analyzed using analysis of variance at the level of p value ≤ 0.05. Further tests for each factor’s main effect and interaction with p values ≤ 0.05 were carried out using the Duncan Multiple Range Test (DMRT). The best distribution of sugar crystal size was obtained from the interaction of sugar seed factors with levels of 3 m³, 5 m³, or 10 m³ which interacted with the quality factor of mother liquor (fine liquor + 0 m3 molasses), and 2 hours of cooking time, Where the results of the interaction of this factor produce a percentage of sugar with a size larger than 0.8 mm as much as 80%.

Abstract: The carbon inclusions in SiC bulk crystals were studied by using optical microscope. The carbon inclusions were classified into three types, namely Type Ⅰ (100~1000 μm), Type Ⅱ (20~50 μm), Type Ⅲ (~5 μm) carbon inclusions based on their different morphologies. In addition, the evolution of these three type carbon inclusions with crystal growth process was traced. It was found that the number of Type Ⅰ and Type Ⅱ carbon inclusions showed declined tendency with crystal growth, while the number of Type Ⅲ carbon inclusions exhibited less dependence on crystal growth. Furthermore, the formation mechanism of carbon inclusions was clarified. This study would give out a better understanding of carbon inclusions, thus contribute to reducing or eliminating carbon inclusions in SiC crystals.

Abstract: Mixing of nano-sized powders with soils (macro-sized powders) is a noteworthy issue for geotechnical projects. Thus, this study examined the horizontal ball mill mixing of nano-copper oxide with kaolinite. Ball milling parameters (rotation speed, weight ratio of balls to powder and milling time) of the planetary ball milling were optimized for proper mixing of nano-copper oxide and kaolinite powder. Results showed that increase in mixing time decreased the agglomeration of nano-copper powders and kaolinite and increased the homogeneity of nano-copper powder with kaolinite particles. The quality of mixing was assessed through intensity and scale of segregation using concentration data obtained through energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. It was observed through these two tests that, increase in ball milling time after 6 hours resulted in grain size reduction. Field emission scanning electron microscopy analysis showed that nano-coppers were regularly found on the surface of kaolinite particles after 6 hrs. of horizontal milling at 4:1 ratio of balls to powder mixture. Furthermore, 24 hrs. mixing resulted in grinding of kaolinite particles and hence their size was reduced. Particle size analysis confirmed these results, as the highest size span value of 3.417 was observed after 6 hrs. milling with speed of 200 rpm.

Abstract: Heat removal from nuclear reactor core has been one of the major Engineering considerations in the construction of nuclear power plant. At the center of this consideration is the nuclear fuel pellet whose burning efficiency determines the rate of heat transfer to the coolant. This research, focuses on the study of temperature distribution of solid fuel, temperature distribution of annular fuel with external cooling and the temperature distribution of annular fuel with internal and external cooling. We analyzed the different distribution and made a conclusion on the possibility of improving temperature management of Nuclear fuel rod, by designing fuel pellets based on this geometrical and thermal Analysis. To date, a lot of studies has been done on the thermal and geometrical properties of Nuclear fuel pellet, it is observed that annular fuel pellet with simulteneous internal and external cooling can achieve better temperature distribution which leads to high linear heat generation rate, thus generating more power in the design [1]. It has also been observed that annular fuel pellets has low fission gas release [10]. In large LOCA, the peak cladding temperature of annular fuel is about 600 which is significantly less than that of solid fuel (920 ), this is due to the fact that annular fuel cladding has lower initial temperature and the thinner annular fuel can be cooled more efficiently than the solid fuel. One of drawbacks of annular fuel technology is “the fuel gap conductance assymmetry” which is caused by outward thermal expansion, it has a potential effect on the MDNBR (Minimum Departure from Nucleate Boiling Ratio), which is the minimum ratio of the critical to actual heat flux found in the core [10]. In this model, we used the ceramic fuel pellet of UO₂ as our case study. All the parameters in this model are assumed parameters of UO₂. The Heat Transfer tool (ANSYS APDL) was used to validate the Analytical Model of this research.

Abstract: An ability of reinforced concrete slabs to distribute concentrated load in transverse direction is an important property for their verification. Several methods for the assessment of transverse distribution (effective width) were proposed but they were not incorporated in the current standards. This paper deals with an experimental analysis of the effective width for shear verification of slabs subjected to concentrated load. Shear resistance of the slab specimens subjected to concentrated load obtained from tests has been compared with resistance of the slab strips loaded by uniform shear. Based on this check, the effective width has been evaluated. Experimental results were also compared with results of models introduced in relevant standards.

Abstract: The polycarbonate (PC) screw cap part had cracking problem during storage, which mechanism needed to be studied. The effect of mechanical processing on the intrinsic stress and its distribution in PC screw cap part was investigated in the paper. The analytical results indicated that the round pieces cut from polycarbonate bar had certain intrinsic stress residue from processing course, which decreased obviously after de-stress heat treatment. Mechanical processing also led to obviously increased intrinsic stress in screw cap part, which could be decreased obviously by another de-stress heat treatment. But the heat treatment increased the aging degree and cracking probability for polycarbonate screw cap part, and was not suggested to carry out on screw cap. Based on the experimental results, some suggestions were also given to lower the intrinsic stress in screw cap.

Abstract: Wonorejo waters have a significant value, both economically and socially. One of ecosystem that have close relationships with Wonorejo waters is Estuary. Temperature and salinity have role in water circulation, where the water circulation have impact to some organism distribution and pollutant dispersion. The purpose of this study is to investigate the characteristic of temperature and salinity distribution in Wonorejo Estuary body’s water. Furthermore, it can be used for determining the type of Wonorejo Estuary. The observation has been done at Wonorejo Estuary in August 2015 to measure the vertical and horizontal temperature and salinity distribution. The measurement of temperature and salinity used Conductivity, Salinity, Temperature tool by YSI. The result show that commonly the temperature and salinity vertical profile are almost similar from surface layer until the bottom layer. But they have trend where the salinity increase, while the temperature decrease to the water depth. There is no thermocline layer due to the shallow water area, it is so from the upper layer until the bottom layer still influenced by dragforce and the vertical mixing between fresh water and sea water occurs. The horizontal temperature distribution in the open sea surface tend to zonation, which is not depend to longitudinal position. The salinity value in each depth are not change obviously indicate that there is a vertical well mixed between fresh water and sea water.

Abstract: The paper describes the method and results of laboratory tests with several types of demountable contact joints and operation tests at functional power industry facilities. The contacts without protective coating are compared with contacts with the protective light-alloy-based coating applied according to the authors’ technology. It is demonstrated that the technology is applicable in real electric equipment operation conditions.

Abstract: The paper analyzes a technology allowing the improvement of such performance characteristics of contact joints as reliability and operating economy, with demountable contact joints taken as an example. The performance characteristics are improved through applying protective metal coatings based on low-melting alloys on the contact members working surfaces. The paper describes the process of alloys selection as well as the development in the technology of the material application onto the contact members.