• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.169-182
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• 2014

High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. U-Mo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

• Computers and Concrete
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• v.32 no.4
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• pp.351-363
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• 2023

Reducing the self-weight of reinforced concrete structures problem is discussed in this paper by using two types of self-weight reduction, the first is by using lightweight coarse aggregate (crushed brick) and the second is by using styropor block. Experimental and Numerical studies are conducted on (LWAC) lightweight aggregate reinforced concrete slabs, having styropor blocks with various sizes of blocks and the ratio of shear span to the effective depth (a/d). The experimental part included testing eleven lightweight concrete one-way simply supported slabs, comprising three as reference slabs (solid slabs) and eight as styropor block slabs (SBS) with a total reduction in cross-sectional area of (43.3% and 49.7%) were considered. The holes were formed by placing styropor at the ineffective concrete zones in resisting the tensile stresses. The length, width, and thickness of specimen dimensions were 1.1 m, 0.6 m, and 0.12 m respectively, except one specimen had a depth of 85 mm (which has a cross-sectional area equal to styropor block slab with a weight reduction of 49.7%). Two shear spans to effective depth ratios (a/d) of (3.125) for load case (A) and (a/d) of (2) for load case (B), (two-line monotonic loads) are considered. The test results showed under loading cases A and B (using minimum shear reinforcement and the reduction in cross-sectional area of styropor block slab by 29.1%) caused an increase in strength capacity by 60.4% and 54.6 % compared to the lightweight reference slab. Also, the best percentage of reduction in cross-sectional area is found to be 49.7%. Numerically, the computer program named (ANSYS) was used to study the behavior of these reinforced concrete slabs by using the finite element method. The results show acceptable agreement with the experimental test results. The average difference between experimental and numerical results is found to be (11.06%) in ultimate strength and (5.33%) in ultimate deflection.

• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.73-80
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• 2012

Nitrogen included in animal manure can be used as organic fertilizer if it is treated properly but it may cause serious air and water pollution without proper management. Significant amount of nitrogen losses happen in the form of ammonia when the manure staying in animal house and storage facilities and being composted and applied to the field. In order to maximize the manure nitrogen utilization, it is important to understand the mechanisms of nitrogen loss during the diverse manure handling and treatment procedures. The plant available nitrogen portion of total nitrogen in excreted manure was evaluated based on animal type, animal manure collection system, manure treatment process, and application method. About 27% of nitrogen included in excreted pig manure could be plant available if it is applied to the filed after composting process. The plant available nitrogen portion varies from 29% (surface application) to 54% (solid injection) based on application method of digestated piggery slurry. Plant can use 18% of manure nitrogen if the composted cattle and poultry manure applied to the field using surface application method. Manure treatment and application methods need to be carefully selected to control and utilize the manure nitrogen properly.

• Progress in Medical Physics
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• v.9 no.4
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• pp.267-276
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• 1998

Any detector inserted into a phantom should have such a geometry that it caused as small as possible perturbation of the electron fluence. Plane parallel chambers meet this requirement better than other chambers of configurations. IAEA protocol recommends the use of plane parallel chambers for this reason. However, the cylindrical chambers are widely used for convenient. The purpose of this study is to evaluate the absorbed dose due to the differences of four different dosimetry protocols such as IAEA protocol using cylindrical chamber, TG 21 protocol using cylindrical chamber, Markus protocol using plane parallel chamber, and TG 39 report for the calibration of plane parallel chamber in electron beams. Depth-ionization measurements for the electron beams of nominal energy 6, 9, 12, 15, and 18 MeV from Siemens accelerator with a 10$\times$10 cm$^2$ field size were made using a radiation field analyser with 0.125 cc ion chamber. Dosimetric measurements by IAEA and TG 21 protocol were made with a farmer type ionization chamber in solid water for each electron energy, respectively. Dosimetric measurements by Markus protocol were made with a plane parallel ionization chamber in solid water for each electron energy, respectively. The cavity-gas calibration factor for the plane parallel chamber was obtained with the use of 18 MeV electron beam as guided by TG 39 report. Dosimetric measurements by TG 39 were performed with a plane parallel ionization chamber in solid water for each electron energy, respectively. For all the energies and protocols, measurements were made along the central axis of the distance of 100 cm (SSD = 100 cm) with 10$\times$10 cm$^2$ field size at the depth of d$_{max}$ for each electron beam, respectively. In the case of 18 MeV, the discrepancy of 0.9 % between IAEA and TG 21 was found and the two protocols were agreed within 0.7 % for other energies. In the case of 18 MeV and 6 MeV, the discrepancies of $\pm$ 0.8 % between Markus and TG 39 was found, respectively and the two protocols were agreed within 0.5 % for other energies. Since the discrepancy of 1.6 % between cylindrical and plane parallel chamber was found for 18 MeV, it is suggested to get the calibration factor using other method as guided. by TG 39.9.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.35-44
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• 2007

The effects of microbial feedstuff additives on feed conversion rate and physical and chemical characteristics of excreta in growing pigs were investigated. Three different products (A, B and C) were compared. Microbial population tests showed B contained higher numbers of total bacteria, Lactobacillus spp. and yeasts. The amylase activity of B was also higher than that of A and C. The daily feed intake rates fer control, A, B and C were 2.06, 2.13, 2.17 and 2.34 kg, respectively. Pigs feed product C had the highest liveweight gain(2.89 kg). However, the results of feed conversion rate were not significantly different between treatments. Amount of faces excreted for control, A, B and C was 1.18, 1,19, 1.23 and 1.32 kg, respectively. Urine volume for control, A, B, and C was 1.91, 1.80, 2.19 and 2.31 kg respectively. Moisture content, T-N, $P_2O_5$ and $K_2O$ in pig manure were not significantly different between treatments. The range of BOD values was 63,453 to $73,758mg/\ell$ for faeces, and 5,678 to $7,428mg/\ell$, for urine. SS values of solid and liquid excreta ranged from 142,200 to 176,000 and from 710 to $1,025mg/\ell$, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.2
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• pp.49-53
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• 2017

We study on the change of electrical properties of two-dimensional (2D) $SnSe_2$ materials with respect to Cl doping as $SnSe_{1.994}Cl_{0.006}$ under a high temperature condition. (300~450 K) By the simple solid-state reaction method, non-and Cl-doped 2D $SnSe_2$ materials are successfully synthesized with negligible impurities as confirmed by X-ray diffraction. From the temperature dependence of resistivity, it is observed that the conduction mechanism is changed from hopping to degenerate conduction with Cl doping. By Hall effect measurement, an increase on electron carrier concentration from ${\sim}7{\times}10^{16}$ to ${\sim}3{\times}10^{18}cm^{-3}$ with Cl doping verifies that Cl is an effective electron donor which results in the encouraged carrier concentration. Detailed analysis for temperature dependent Hall mobility reveals that the electrical transports in high temperature regime are governed by the grain boundary-controlled mechanism for non-doped $SnSe_2$, which is effectively suppressed by Cl-doping as entering metallic transport regime.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.2
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• pp.123-129
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• 2010

Purpose: The purpose of this study was to evaluate dosimetric characteristics of Optically stimulated luminescent dosimeters (OSLD) for dosimetry Materials and Methods: InLight/OSL $NanoDot^{TM}$ dosimeters was used including $Inlight^{TM}MicroStar$ Reader, Solid Water Phantom, and Linear accelerator ($TRYLOGY^{(R)}$) OSLDs were placed at a Dmax in a solid water phantom and were irradiated with 100 cGy of 6 MV X-rays. Most irradiations were carried out using an SSD set up 100 cm, $10{\times}10\;cm^2$ field and 300 MU/min. The time dependence were measured at 10 minute intervals. The dose dependence were measured from 50 cGy to 600 cGy. The energy dependence was measured for nominal photon beam energies of 6, 15 MV and electron beam energies of 4-20 MeV. The dose rate dependence were also measured for dose rates of 100-1,000 MU/min. Finally, the PDD was measured by OSLDs and Ion-chamber. Results: The reproducibility of OSLD according to the Time flow was evaluated within ${\pm}2.5%$. The result of Linearity of OSLD, the dose was increased linearly up to about the 300 cGy and increased supralinearly above the 300 cGy. Energy and dose rate dependence of the response of OSL detectors were evaluated within ${\pm}2%$ and ${\pm}3%$. $PDD_{10}$ and PDD20 which were measured by OSLD was 66.7%, 38.4% and $PDD_{10}$ and $PDD_{20}$ which were measured by Ion-chamber was 66.6%, 38.3% Conclusion: As a result of analyzing characteration of OSLD, OSLD was evaluated within ${\pm}3%$ according to the change of the time, enregy and dose rate. The $PDD_{10}$ and $PDD_{20}$ are measured by OSLD and ion-chamber were evaluated within 0.3%. The OSL response is linear with a dose in the range 50~300 cGy. It was possible to repeat measurement many times and progress of the measurement of reading is easy. So the stability of the system and linear dose response relationship make it a good for dosimetry.

• Archives of design research
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• no.18
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• pp.25-34
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• 1996

Industrial design development methods and processes have changed in accordance with Industrial Information Age. These days, problems are created by existing methods and evaluation of design value , all problems concerned with time and finances sitaution have been made a subject of discussion. Development of design processes have been changed by the development of problem recognition and solving tools, and dpsign tpchnulugy havp hppn replaced by computer technology,Thus. software design processes linking thoughtware to hardware are used in the solution of design problems with many parts. In this study, 3D Modeling samples are presented, 3D Modeling can realise ' Ideas' to '3Dimentional Virtual Ohjects'. These effect and value are anle to decisively influence the process of design problem conference-ebealuation-solution.Proxesses of actual modeling and rendering are made as follows. By compusition of simple 20 drawings and shaping them into 30 objects, 30 solid models can be made. To prssent effectivley, we can make a sample model by varying camera views,light sourses,materials and colours etc. This sample is evaluated by various cumposition, methods and PERT(Program Evaluation and Review Technique). This cuncrete sample (tentative plan)is changed within the CAD SYSTEM by design evaluation, and then converted to flowchart of mass productive conception through refined data. So, that tentative plan can be conformed to design desire actuillly, to the utmost degree. Finally, this design process can be proposed as il new method in cuntrast with current methods. The aim of this study is to suggest effective evaluation methods of design outcome among many evaluating elements.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.272-279
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• 2012

In order to effectively treat livestock wastewater in constructed wetlands by natural purification method, removal velocities of pollutants under different injection methods in constructed wetlands were investigated. The removal velocities of chemical oxygen demand (COD), suspended solid (SS), T-N and T-P by continuous injection method were slightly rapid than those by intermittent injection method in full-scale livestock wastewater treatment plant. The removal velocity (K; $day^{-1}$) of COD by continuous injection method was $0.38\;d^{-1}$ for $1^{st}$ bed, $0.13\;d^{-1}$ for $2^{nd}$ bed, $0.17\;d^{-1}$ for $3^{rd}$ bed, $0.05\;d^{-1}$ for $4^{th}$ bed and $0.17\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of COD in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.210\;d^{-1}$, $0.086\;d^{-1}$, $0.222\;d^{-1}$, $0.053\;d^{-1}$ and $0.137\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of SS by continuous injection method was $0.750\;d^{-1}$ for $1^{st}$ bed, $0.108\;d^{-1}$ for $2^{nd}$ bed, $0.120\;d^{-1}$ for $3^{rd}$ bed, $0.086\;d^{-1}$ for $4^{th}$ bed and $0.292\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of SS in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.485\;d^{-1}$, $0.056\;d^{-1}$, $0.174\;d^{-1}$, $0.081\;d^{-1}$ and $0.227\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of T-N by continuous injection method was $0.361\;d^{-1}$ for $1^{st}$ bed, $0.121\;d^{-1}$ for $2^{nd}$ bed, $109\;d^{-1}$ for $3^{rd}$ bed, $0.047\;d^{-1}$ for $4^{th}$ bed and $0.155\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of T-N in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.235\;d^{-1}$, $0.071\;d^{-1}$, $0.171\;d^{-1}$, $0.058\;d^{-1}$ and $0.126\;d^{-1}$, respectively. The removal velocity (K; $day^{-1}$) of T-P by continuous injection method was $0.803\;d^{-1}$ for $1^{st}$ bed, $0.084\;d^{-1}$ for $2^{nd}$ bed, $0.076\;d^{-1}$ for $3^{rd}$ bed, $0.118\;d^{-1}$ for $4^{th}$ bed and $0.301\;d^{-1}$ for $5^{th}$ bed. The removal velocities (K; $day^{-1}$) of T-P in $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$ and $5^{th}$ beds by intermittent injection method were $0.572\;d^{-1}$, $0.049\;d^{-1}$, $0.090\;d^{-1}$, $0.112\;d^{-1}$ and $0.222\;d^{-1}$, respectively.

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.49-54
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• 2011

Animal manure is produced annually 43.7 million tonnes in Korea. Among them, about 85.6 % are used as compost or liquid fertilizer to the agricultural land. The animal manure can be effectively utilized by mixing with organic byproducts that result in generation of biogas from anaerobic co-digestion process. This study aimed to optimize the content of total solid materials (TS) and determine the effect of organic byproduct on the co-digestion process. Prior to the byproduct treatments, determination of proper content of TS was conducted by controlling at 5 or 10 %. For the byproduct treatments, swine manure without adding the byproduct was used for control treatment, and swine manure mixed with either corn silage or kitchen waste was used for other treatments. Volume of biomethane ($CH_4$) generated from digested materials was quantified before and after byproduct treatments. In result, a 1.4-fold higher biomethane, about 0.556 L/$L{\cdot}d$, was produced when the content of TS was controlled at 10 %, compared at 5 %, about 0.389 L/$L{\cdot}d$. When the swine manure was mixed with the corn silage or kitchen waste, a two-fold higher biomethane was produced, about 1.theand 1.0heL/$L{\cdot}d$, respectively, compared to the control treatment. Biogas production from organic dry matter (odm) was a3, 362eand 2h6 L/kg odm${\cdot}$d for control, corn silage, and kitchen waste treatment, respectively. The lower biogas production in the treatment of kitchen waste than that of corn silage is associated with its relatively high odm contents. The methane concentration during the whole process ranged from 40 at the beginning to 70 % at the end of process for both the control and kitchen waste treatments, and ranged from 52 to 70 % for the corn silage treatment. Hydrogen sulfide ($H_2S$) concentration ranged between 350 and 500 ppm. All the integrated results indicate that addition of organic byproduct into animal manure can double the generation of biogas from anaerobic fermentation process.