• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.2
• /
• pp.250-257
• /
• 2011

An experiment was conducted to determine the effects of different mycotoxin adsorbents including esterified glucomannan (EGM), hydrated sodium calcium aluminosilicate (HSCAS) and compound mycotoxin adsorbent (CMA) on performance, blood parameters, and liver pathological changes in broilers fed mold-contaminated feed. Two hundred and forty 10-day-old broilers were randomly assigned to one of the five dietary treatments including: i) control diet; ii) mold-contaminated diet; iii) moldcontaminated diet+0.05% EGM; iv) mold-contaminated diet+0.2% HSCAS; v) mold-contaminated diet+0.1% CMA. At 35-days-old, blood and liver tissue samples were collected for analysis. 0.1% CMA improved ADG and ADFI during 10-42 d compared to the moldcontaminated group (p<0.05). The mold-contaminated diet increased total white blood cell (WBC) number, haemoglobin (Hgb) concentration, hematocrit (Hct) level, serum aspartate aminotransferase (AST) and ${\gamma}$-glutamyl transferase (GGT) activities, and decreased red blood cell (RBC) number and serum globulin (GLB) and urea nitrogen (BUN) concentrations (p<0.05). The three mycotoxin adsorbents alleviated the alteration of RBC, WBC, Hgb and AST caused by the mold-contaminated diet. Furthermore, 0.1% CMA increased GLB concentration and decreased Hct level and GGT activity (p<0.05). Liver superoxide dismutase (SOD) activity was reduced, and myeloperoxidase (MPO) activity was increased by the mold-contaminated diet (p<0.05). Both EGM and HSCAS prevented the increase of MPO activity (p<0.05). Liver lesion, including severe vacuolar degeneration of hepatocytes, was observed in chicks fed the mold-contaminated diet. 0.05% EGM prevented these effects except for biliary hyperplasia and mild vacuolar degeneration. 0.2% HSCAS showed medium vacuolar degeneration of hepatocytes. Liver of broilers fed 0.1% CMA revealed a mild vacuolar degeneration. These results indicate that a mold-contaminated diet results in adverse effects on blood parameters and liver morphology. 0.05% EGM and 0.2% HSCAS partially alleviated the adverse effects. However, 0.1% CMA almost completely ameliorated the adverse effects.

• Design & Manufacturing
• /
• v.14 no.3
• /
• pp.8-16
• /
• 2020

In this study, the vibration signal of the mold was measured and analyzed to monitoring the process time and characteristics during injection molding. A 5 inch light guide plate mold was used to injection molding and the vibration signal was measured by MPU6050 acceleration sensor module attached the surface of fixed mold base. Conditions except for injection speed and packing pressure were set to the same value and the change of the vibration signal of the mold according to injection speed and packing pressure was analyzed. As a result, the vibration signal had a large change at three points: "Injection start", "V/P switchover", and "Packing end". The time difference between "injection start" and "V/P switchover" means the injection time in the injection molding process, and the time difference between "V/P switchover" and "Packing end" means the packing time. When the injection time and packing time obtained from the vibration signal of the mold are compared with the time recorded in the injection molding machine, the error of the injection time was 2.19±0.69% and the error of the packing time was 1.39±0.83%, which was the same level as the actual value. Additionally, the amplitude at the time of "injection start" increased as the injection speed increased. In "V/P switchover", the amplitude tended to be proportional to the pressure difference between the maximum injection pressure and the packing pressure and the amplitude at the "packing end" tended to the pressure difference between the packing pressure and the back pressure. Therefore, based on the result of this study, the injection time and packing time of each cycle can be monitored by measuring the vibration signal of the mold. Also, it was confirmed that the level and trend of process variables such as the injection speed, maximum injection pressure, and packing pressure can be evaluated as the change of the mold vibration during injection molding.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.7
• /
• pp.561-567
• /
• 2014

Precision injection mold is an essential element in order to manufacture small and precision plastic lenses used for phone camera. There are many critical factors to meet the requested specifications of high quality plastic lenses. One of the main issues to realize high quality is minimizing decenter value, which becomes more critical as pixel numbers increases. This study suggests the method to minimize decenter value by modifying ejecting structure of the mold. Decenter value of injection-molded lens decreased to 1 ${\mu}m$ level from 5 ${\mu}m$ by applying suggested ejecting method. Also, we also developed BIS (Built-in Sensor) based smart mold system, which has pressure and temperature sensors inside of the mold. Pressure and temperature profiles from cavities are obtained and can be used for deduction of optimal injection molding condition, filling imbalance evaluation, status monitoring of injection molding and prediction of lens quality.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1073-1077
• /
• 2003

This study aims to investigate the fabrication process of nano silicon mold using electron beam lithography (EBL) to generate the nanometer level patterns by nano-imprinting technology. the nano-patterned mold including 100mm pattern size has been fabricated by EBL with different doses ranged from 22 to 38 ${\mu}C/cm^2$ on silicon using the conventional polymethylmetharcylate(PMMA) resist. The silicon mold is fabricated with various patterns such as circles, rectangles, crosses, oblique lines and mixed forms, The effect of dosage on pattern density in EBL is discussed based on SEM (Scannning Electron Microscopy) analysis of fabricated molds. The mold surface is modified by hydrophobic fluorocarbon (FC) thin films to avoid the stiction during nano-imprinting process.

• Korean Journal of Poultry Science
• /
• v.15 no.4
• /
• pp.269-275
• /
• 1988

The effect of mold inhibitor was determined in the commercial rations which had two different protein levels(18% and 12% ) and two different particle sizes(80% of the particles in the ration less than 1.19mm and 40% of the particles in the ration less than 1.1mm). After 40 days storage of the rations treated and not treated with the mold inhibitor the nutritional change of the experimental diets with 18% and 12% protein levels, the growth performance of chicks, and the weight of internal organs fed the 18% protein diet were observed as the criteria of this research The fat level and carotene content in the two diets with 18% and 12% protein level each were significantly (P＜0.05) decreased when the diets were not treated by the mold inhibitor. Even if mold inhibitor was mixed in the diet, the fat content in the diet which had 40% of the particles in the ration less than 1.19mm tended to be decreased, especially, in the diet with a 12% protein level. The carotene content in the diet treated with mold inhibitor which had 40% of the particles in the ration less than 1.19mm also tended to be decreased in both diets (18% protein and 12% protein). Feed types$\times$particle size interaction was significant for the fat content (P＜0.05) and for the carotene content (P＜0.05). The amount of crude protein and ADF was not significantly (P＞0.05) changed after 40 days storage. There was a significant decrease (P＜0.05) in total body weight gain and total feed intake observed in chicks fed the untreated diet with 40% of the particles in the ration less than 1.19mm. Feed conversion was significantly (P＜0.05) depressed in the chicks fed the untreated diet of both particle sizes. Particle size$\times$types of feed interaction in feed conversion was significant (P＜0.05). Relative sizes of the liver, pancreas and spleen were not affected significantly (P＞0.05) by the treatments.

• Korean Journal of Poultry Science
• /
• v.15 no.4
• /
• pp.261-268
• /
• 1988

The effect of two particle size ranges (80% of the particles in the ration less than 1.19mm ; and 40% of the particles in the ration less than 1.1mm) and two different levels of protein (18% and 12% ) on the activity of mold inhibitors in commercial ration was determined by measuring mold count, CO$30^{\circ}C$ production and aflatoxin concentration. A commercial fungistat was mixed in the treated diets at the level of 0.1% (W/W). Two types of experimental diets (18% & 12% protein) which contained 12.6 and 12.7% moisture content each were stored under the forced air humidifier at 85% humidity and a controlled-temperature of 29＋1$30^{\circ}C$ for 5 to 40 days. Mold count and CO$30^{\circ}C$ levels in the feed treated with mold inhibitor were significantly higher (P＜0.05 and P＜0.01 respectively) when 40% of the ration's particle size was<1.19mm. The different protein levels in the ration treated with mold inhibitor did not have a significant effect (P＞0.05) on the mold count and $CO_2$ production. Protein level $\times$ particle size range interaction on the $CO_2$ production was significant (P＜0.05). Aflatoxin production in the experimental diet with mold inhibitor was significantly (P＜0.05) affected by the levels of protein and the different particle size ranges. The interaction of protein levels and particle size ranges on the aflatoxin production was significant (P＜0.05) at 40 days of storage.

• Journal of the Korean Society of Industry Convergence
• /
• v.21 no.1
• /
• pp.1-8
• /
• 2018

The purpose of this study is to develop a high-strength, high-toughness, thin-walled aluminum shock absorber housing product by applying a high vacuum die casting method to improve internal gas defect and formability. The analysis program dedicated for the casting was used because it was too costly and time-consuming to adopt the gating system design. The final casting plan was designed based on the flow pattern of the material filled into the mold and the result of air pressure and air pocket after the material was completely filled in the mold. Gaty shape was designed as a split type. The runner was designed to have the same shape as the initial inlet curve of the cavity, and the flow of the molten metal was prevented from turbulent flow. The most favorable results were obtained when the injection speed was $V_2=4.0m/s$. Defects on pores were reduced by applying high vacuum level inside the mold.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.9
• /
• pp.1-8
• /
• 2020

In this study, the optimal design of the multi-cavity mold layout and packing pressure for the automobile TCU connector cover is determined based on the injection molding analysis and the desirability function method for multi-characteristic optimization. The design characteristics to be optimized are the warpage and sink marks of the product, the scrap of the feed system, and the clamping force. The optimal design is determined by performing injection molding analysis and desirability analysis for design alternatives defined by a complete combination of five mold layouts and six-level packing pressure. The optimal design shows that the desirability values for individual characteristics are quite high and balanced, and the resulting values of individual characteristics are satisfactorily low.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2006.05a
• /
• pp.269-272
• /
• 2006

Surface contacts between mold and target should be in parallel for the imprinting mechanism. However, the size of contacting area makes it difficult for both mating surfaces to be in all contact because of precision level of the imprinting machine and the waviness of mold and target. The gripping force for both mold and target with the vacuum chuck is also major effect to interrupt the full contact, which must be avoided in imprinting mechanism. In this study, the preliminary study for the causes of non-uniformity of contacting surfaces such as mold and target is performed with $470{\times}370mm^2$ LCD panel size.

• Design & Manufacturing
• /
• v.14 no.4
• /
• pp.52-57
• /
• 2020

In this study attempted to prevent defects due to blow holes among defects of sand casting products. It was intended to reduce the defect rate by reducing the blow hole of the inner surface. Currently, expectations and requirements for the quality level of non-ferrous aluminum casting in the casting industry are increasing. In addition, the shape is complex and the shrinkage precision is required. Among them, the test prototype is expensive to manufacture the mold, and the production time is also long, and the product is manufactured by sand casting. At this time, the highest defect rates are defects caused by shrinkage defects, surface defects, and blow holes.. At this study, the manufacturing time was shortened by using the shape of the fluid movement path in advance. Also, it is possible to reduce defects due to blow holes.