• Transactions of the Korean hydrogen and new energy society
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• v.31 no.6
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• pp.614-621
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• 2020

Recently, as the fine dust is increased and the emission regulations of diesel engines are strengthened, interest in diesel soot filtration devices is rapidly increased. In particular, there is a demand for technology development for higher efficiency of diesel exhaust gas after-treatment devices. As part of this, many studies conducted to increase the exhaust gas treatment efficiency by improving the flow uniformity of the exhaust gas in the DPF and reducing the pressure drop between the inlet and outlet of disel particle filter (DPF). In this study, computational fluid dynamics (CFD) simulation was performed when exhaust gas flows into the canning reduction device equipped with a 13" asymmetric DPF in order to maintain the flow uniformity in the diesel exhaust system and reduce the pressure. In particular, a study was conducted to find the geometry with the smallest pressure drop and the highest flow uniformity by simulating the DPF I/O ratio, exhaust gas temperature, inlet-outlet pressure and flow uniformity according to the geometry and hole size of distributor.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.114-121
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• 2023

During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.5
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• pp.721-738
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• 2015

This research analyzed emergency foods in Korea during the Japanese occupation through the food literature of that era, and attempted to determine the cultural history of food through recorded contents of emergency foods literature. The examination was mainly conducted on the basis of the four excerpts within the emergency foods literature of the Japanese occupation: "Emergency plants of the Joseon", "Wild Fruits and Plants of the Joseon", "Guhwangginam", and "Emergency Plants and How to Eat of the Joseon". After a thorough examination, each of the excerpts had unique data regarding amounts of ingredients, such as Namuls, trees, grain, and beans. "Emergency Plants of the Joseon" listed 142 Namuls, 54 trees,"Wild Fruits and Plants of the Joseon" listed 32 Namuls, 29 trees, "Guhwangginam" 4 grains, 205 Namuls, 84 trees, "Emergency Plants and How to Eat of the Joseon" listed five grain, three beans, 37 Namuls, and eight trees. Emergency foods literature demonstrated the utilization of various wild and edible plants as excellent ingredients for meals. Additionally, changes in traditional cooking methods using sugar, preservation through canning, and frying substantiate the subtle influence of foreign influence on Korean food. Perhaps the carefully structured components of the Korean food can be interpreted as a direct result of a scientific approach. It can be argued that creative application of methods ingredients, approach, of emergency foods is necessary to this modern age.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.17-21
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• 1971

The effect of EDTA or BHA pretreatment upon the color preservation of canned surf clam meat during canning and storage was studied. The steamed surf clam meat was soaked in BHA solution, $0.1\%$ BHA in $5\%$ salt solution, or EDTA solution, $0.5\%\;Na_2$ EDTA in $5\%$ salt solution, for 30 minutes. The pretreated surf clam meat was packed in a round enameled can that is 223.2 ml by volume and sterilized for 75 minutes at $110^{\circ}C$. The canned products were stored for one year at room temperature. The EDTA treatment of surf clam meat appeared effective on color preservation during processing. After three month storage, the samples showed little color change comparing with those right after processing. After one year storage, EDTA or BHA treated samples showed better color preservation as compared with control.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.1
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• pp.12-17
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• 2014

The cooling of precooked skipjack Katsuwonus pelamis is a critical thermal process in tuna canning because it affects the quality and yield of the canned tuna, as well as productivity. The combined method of vacuum cooling followed by water spraying (VC-WS) was investigated to increase cooling rates, and prevent loss of yield of the precooked tuna during vacuum cooling. For VC-WS, the precooked skipjack was cooled to $30^{\circ}C$ by vacuum at 31 mmHg and then wetted by spraying water for 2 min. The effects of VC-WS on cooling times, cooling loss, color, texture and lipid oxidation of the precooked tuna were compared with conventional spray cooling (SC).The cooling times for precooked skipjack from $75^{\circ}C-30^{\circ}C$ were 11 min for VC-WS and 145 min for SC. The cooling losses were 1.7 % for VC-WS and 1.6 % for SC. Peroxide and thiobarbituric acid (TBA) values of VC-WS were lower than those of SC. The loin of the VC-WS-treated skipjack was brighter and harder than the SC loin, as indicated by higher lightness and hardness values. Based on these results, we believe that the VC-WS process could compensate for the cooling loss of vacuum cooling and minimize changes in quality that occur during cooling of precooked skipjack tuna.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.115-120
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• 1974

Secondary amines are known as one of the precursors of nitrosamines which are potent carcinogenic compounds of man and animals. Nitrosamines are formed when both secondary amines and nitrite are present. The nitrites are occurred naturally in vegetables, fruits and many others, and frequently used in fish product as a color fixative or a preservative. In this paper, to know the formation of nitrosamines in fish meat, the changes of dimethylamine (DMA) content during the heat treatment such as drying, roasting and fish cake processing are discussed. The results showed that generally DMA increased considerably during heat processing. During drying, DMA in cuttle fish increased 16 times higher, while in Alaska pollack doubled than the fresh. In the roasted mackerel, the DMA content appeared 6 times higher than the fresh, while 9 times higher in canning. In fish cake from yellow corvenia, DMA increased 4 times higher than the fresh. On the contrary diethylamine and diphenylamine were not found in this experiment.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.18-25
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• 1990

Paralytic Shellfish Poison (PSP) is mainly produced by marine dinoflagellates such as Protogonyaulax sp. and Pyrodinium sp.. The PSP was known to be accumulated in digestive gland of shellfish as result of feeding toxic dinoflagellates. PSP illness when occurs when one eats PSP intoxicated shellfish. Therefore PSP is becoming as serious problem in food hygiene and shellfish cultivation industry. The purpose of this study was to develop detoxification method for utilization of PSP intoxicated sea mussel and prevent from PSP illness. The PSP was extracted with 0.1 N HCl solution from the submitted sea mussel, then the toxicity was measured by mouse assay according to Official Methods of Analysis of the Association of Official Analytical Chemists. No detoxification effect was observed by adding extracted juice of garlic and ginger. When the sea mussel homogenate was heated at various temperatures, the PSP toxicity was not changed significantly at below $70^{\circ}C$ for 60 minutes but it was decreased as the heating temperature was increased. For example, when the sea mussel homogenate was heated at 100, $121^{\circ}C$ for 10 minutes, the toxicity was decreased about 67 and 90%, respectively. When the sea mussel containing 645 $\mu$g PSP per 100g of edible meat was processed according to general shellfish canning procedure, the toxicity was decreased as the level of PSP undetected by mouse assay.

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.17-33
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• 1990

The purpose of this study was to evaluate the fracture toughness of dental composite resins and to investigate the filler factor affecting the fracture behaviour on which the degree of fracture toughness depends. Six kinds of commercially available composite resin;, including two of each macrofilled, microfilled, and hybrid type were used for this study, The plane strain fracture toughness ($K_{10}$) was determined by three-point bending test using the single edge notch specimen according to the ASTM-E399. The specimens were fabricated with visible light curing or self curing of each composite resin previously inserted into a metal mold, and three-point bending test was conducted with cross-head speed of 0.1mm/min following a day's storage of the specimens in $37^{\circ}C$ distilled water. The filler volume fractions were determined by the standard ashing test according to the ISO-4049. Acoustic Emission(AE), a nondestructive testing method detecting the elastic wave released from the localized sources In material under a certain stress, was detected during three-point bending test and its analyzed data was compared with, canning electron fractographs of each specimen. The results were as follows : 1. The filler content of composite resin material was found to be highest in the hybrid type followed by the macrofilled type, and the microfilled type. 2. It was found that the value of plane strain fracture toughness of composite resin material was in the range from 0.69 MPa$\sqrt{m}$ to 1 46 MPa$\sqrt{m}$ and highest In the macrofilled type followed by the hybrid type, and the microfilled type. 3. The consequence of Acoustic Emission analysis revealed that the plane strain fracture toughness increased according as the count of Acoustic Emission events increased. 4. The higher the plane strain fracture toughness became, the higher degree of surface roughness and irregularity the fractographs demonstrated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.893-899
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• 1996

The studies on the detoxification of paralytic shellfish poison (PSP)-infested blue mussels, Mytilus edulis and oyster, Crassostrea gigas were performed for using of available processing resource. Toxic blue mussel and oysters from Nampo in Masan Bay, Hachong in Koje Bay and Woepori in Koje were used for experimental samples. The toxicity of low toxic blue mussel $(A,\;84{\mu}g/100g;\;B,\;166{\mu}g/100g;\;C,\;295{\mu}g/l00g;\;D,\;557{\mu}g/100g)$ and oyster $(740{\mu}g/100g)$ were reduced below the regulation limit of PSP $(80{\mu}g/100g)$ or undetected level by mouse bioassay after boiling at $98^{\circ}C$ for 10 min and retorting at $115^{\circ}C$ for 70 min, while the toxicity of high toxic blue mussel $(E,\;8,760{\mu}g/100g)$ remained beyond the regulation limit after boiling and retorting at same condition. These results suggested that the regulation limit of PSP could be level up from $(80{\mu}g/100g)$ to about $160{\mu}g/100g$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.287-295
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• 1996

To fulfill the requirements for establishing processes of canning low-acid foods, canned tuna packed in cottonseed oil (CTCO) sterilized at $110^{\circ}C$ for varying $F_0-values$ was subjected to microbial, sensory and chemical analyses. The investigation included the long-term quality stability of those products stored at $5^{\circ}C,\;25^{\circ}C\;and\;50^{\circ}C$ for 120 days. Longer sterilization $(F_0>5.18min)$ caused no remarkable changes in pH, amino nitrogen content, TBA value, POV and sensory scores of the CTCOs during storage at all experimental temperatures. But the sterilizing with $Fe\leq5.18min$ resulted generally poor quality in all experimental analyses. Consequently, $F_0-value$ 6.0 min may be applicable to sterilization of CTCO for long-term storage stability.