Abstract
Several studies related to simplifying the modeling of pebble bed High-Temperature Reactor core (HTR) has been developed before. From some calculation on several MCNP models with a fueled ...pebble to dummy ratio 57:43, using a combination of several types of TRISO (TRi-structural ISOtropic particle fuel) unit and Pebble unit is modeled to achieve its first criticality. In this paper, some MCNP model that uses 27000 pebbles with a 57:43 ratio and 100% fueled pebble is created to be used on burnup calculation and to compare its k-eff and nuclide inventory. From this burnup calculation, it could be seen that SC (Simple Cubic) TRISO unit has faster calculation time followed by the HCP (Hexagonal Close Packed) TRISO unit and then the FCC (Face-Centered Cubic) TRISO unit. The BCC (Body-Centered Cubic) pebble unit had some consistent deviation from another pebble unit, and it still needs more study to know more about the reason behind it. It could be seen that if there are some dummy pebbles inside the reactor, then the deviation would be higher than if there is just fueled pebble inside the reactor. On the 57:43 ratio, the absolute average deviation of k-eff on burnup calculation is lower than 2% and 10% for nuclide inventory (mass). On 100% fueled pebble, it’s below 0.15% on k-eff absolute deviation and below 8% on nuclide inventory deviation.
Abstract
A 150MWt pebble bed high temperature reactor, called PeLUIt-150, is proposed as a solution for distributed energy demand including the electricity and various co-generation potentials. In ...current study an optimization of the design is performed. The optimization includes its optimum power density to have a compact core design including the height-to-diameter (H/d) ratio. As several computer codes is used in this study, PEBBED-THERMIX codes, comparison of results from different code is also discussed. Constrain of the design at current stage are the maximum fuel temperature under depressurized loss of forced cooling (DLOFC) accident which represent the passive performance of the core, and discharge burnup which represent the fuel utilization performance of the core. Current study achieves an optimized design with core diameter and height of 260 cm and 601.11cm, a total active core volume of 31.9 m
3
. The average power density is 4.7W/c m
3
with discharge burnup of 80.82MWd/Kg and the maximum fuel temperature after DLOFC is 1619.9°C.
The accumulation of plutonium produced by LWR operations causes public concern related to its radiotoxicity and proliferation issue. Therefore, there is some interest in developing various methods ...for consuming plutonium through plutonium incineration i.e., by utilising thorium-based nuclear fuel. Thorium-plutonium mixed oxide fuel (Thorium MOX) is an attractive option considered for plutonium incineration. The aim of the study is to investigate the neutronic characteristics of Thorium MOX fuel in VVER-1000 nuclear reactor fuel assemblies. The VVER-1000 Benchmark model was utilised in the present study. A series of calculations were performed with the MCNP6 code and the ENDF/B-VII library. The calculation results show that a proper increase in Pu content could increase
of ThMOX fuel, so it could have almost the same
with MOX fuel or increase Pu content when needed. It was also shown that Thorium MOX fuel assembly had more negative Doppler reactivity due to neutron capture by thorium (
Th). The moderator temperature coefficient was found to be more negative than the Doppler coefficient, and it could be concluded that replacing uranium with thorium could reduce the amount of plutonium produced while increasing plutonium consumption.
Bioflocculant is an extracellular biopolymer substance secreted naturally by microorganisms during their growth. It has piqued the interest of many researchers due to its biodegradability, nontoxic ...properties, and potential as a substitute for conventional flocculant where its usage may lead to environmental and health issues. In the present study, Aspergillus niger DWB was used to investigate the production and characterization of bioflocculant. The bioflocculant was produced by utilizing agricultural residue from the oil palm industry, oil palm empty fruit bunch (OPEFB) fiber as the carbon source. The effect of pH of the medium, as well as the inoculum size on the bioflocculant production, was examined. The maximum bioflocculant yield obtained after 48 h of fermentation was 9.48%/g substrate under tested condition. In addition, the bioflocculant produced showed a good flocculating rate in kaolin suspension at pH 6, within 15 min of retention time and using 4 ml of bioflocculant dosage. The functional group of the extracted bioflocculant was determined using Fourier-transform infrared (FTIR) spectroscopy, which revealed the presence of hydroxyl and carboxyl groups. These functional groups attributed to their flocculating abilities. The results obtained from this study suggested that the agricultural waste, OPEFB fiber can serve as a suitable solid substrate in the production of bioflocculant.
•Aspergillus niger DWB was investigated for the production of bioflocculant using oil palm empty fruit bunch fiber.•Under optimized conditions, the maximum bioflocculant yield obtained is 9.48%/g substrate.•The bioflocculant showed a good flocculating rate (60.55%) in kaolin suspension at pH 6, within 15 min of retention time and using 4 ml of bioflocculant dosage.•FTIR spectroscopy revealed the presence of hydroxyl and carboxyl groups which attributed to flocculating abilities.•OPEFB fiber can serve as a suitable solid substrate for the production of bioflocculant.
Abstract
Physiological conditions were one factors that can affect the growth of cattle. The study aimed to determine the physiological responses of several beef cattle breeds that are reared in Beef ...Cattle Research Station (BCRS), Grati District, Pasuruan Regency, East Java Indonesia, was carried out by measure temperature, humidity, Temperature Humidity Index (THI), rectal temperature, respiration frequency, body temperature, Head Tolerance Coefficient (HTC) and heart rate of 159 cows consisting of Bali, Madura, Jabres, Galekan, Rambon, Peranakan Ongole (PO), Belgian Blue x PO cross, PO x Bali cross (POBA) which were observed during 4 months in pens. Data were analysed descriptively. The result of the study were ambient temperature and relative humidity of the pen ranged from 25-34.12°C and 54.88-84.27%, THI ranged from 74.92-84.97, body temperature ranged from 35.06-38.53°C, respiration frequency ranged from 20-54 times/minute, HTC ranged from 1.81-3.34, and heart rate ranged from 65-92 times/minute. It was concluded that several breeds of beef cattle in BCRS have mild to severe heat stress, high heat tolerance, respiration rate and heart rate. This condition does not cause production problem in several beef cattle, but in BB x PO cross it has potential to low productivity.
This paper is focusing on strength and water absorption properties of lightweight concrete brick containing Expanded Polystyrene (EPS) and Palm Oil Fuel Ash (POFA) as partial replacement materials of ...fine aggregates and cement respectively. EPS has been chosen as lightweight aggregates material due to its characteristic which is extremely light. Meanwhile, POFA has been chosen as cement replacement due to the cementitious characteristic which could act as the binder in the concrete mixture. The replacement percentage of EPS is 0%, 20%, 30%, 40% and 50% whilst the replacement percentage of POFA is 0%, 5%, 10%, 15%, 20% and 25%. The brick properties that have been investigated in this study are density, water absorption and compressive strength. Based on the experimental results, the density and compressive strength of the brick is decreased as the percentage of the replacement increased. Meanwhile, for water absorption, it was found that the percentage of water absorption of brick was increased as the percentage of POFA increased, and it was decreased as the percentage of EPS increased. Based on the findings, the properties obtained has satisfied the requirement where the brick density for lightweight should be less than 1680 kg/m3 and the strength for load bearing and non-load bearing brick is 11.7 MPa and 3.45 MPa for each individual unit. Meanwhile, for water absorption, the percentage of water absorption of brick should be less than 12% 1,2. From this study, it was found that, the replacement of sand and cement by EPS and POFA give significant impact towards density, strength and water absorption performance of concrete brick.
The purpose of the study was to identify and describe the translation techniques, methods and ideologies used in translating Arabic cartoon subtitles Muhsin and Mahasin versions of the Youtube ...channel SFH channel and describe the quality of the translation as the impact of the techniques, methods, and ideologies applied, in terms of accuracy, acceptance and ,readability. This research uses qualitative approaches using qualitative descriptive methods. Included in the study data are Arabic video subtitles Muhsin and Mahasin, while the data sources are muhsin videos and Mahasin link versions https://youtu.be/PZ3DPvdvVdI. The data collection technique used is scriptwriting. After the data collection process, analysis is also carried out. The findings of the study showed that there are six kinds of translation techniques. Based on the dominant techniques that occur, translators tend to use communicative translation methods and domestication as their ideology. Then, the impact of the application of translation techniques, methods and ideologies on the quality of translation as a whole has accuracy, acceptance, and readability. This shows the quality of good translation.
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