Jong-Hyeong Kim

Production of Endoglucanase, Beta-glucosidase and Xylanase by Bacillus licheniformis Grown on Minimal Nutrient Medium Containing Agriculture Residues

Bacillus licheniformis was grown in minimal nutrient medium containing 1% (w/v) of distillers dried grain with soluble (DDGS), palm kernel meal (PKM), wheat bran (WB) or copra meal (CM), and the enzyme activity of endoglucanase, β-glucosidase, xylanase and reducing sugars was measured to investigate a possibility of using cost-effective agricultural residues in producing cellulolytic and hemicellulolytic enzymes. The CM gave the highest endoglucanase activity of 0.68 units/mL among added substrates at 48 h. CM yielded the highest titres of 0.58 units/ml of β-glucosidase, compared to 0.33, 0.23, and 0.16 units/mL by PKM, WB, and DDGS, respectively, at 72 h. Xylanase production was the highest (0.34 units/mL) when CM was added. The supernatant from fermentation of CM had the highest reducing sugars than other additional substrates at all intervals (0.10, 0.12, 0.10, and 0.11 mg/mL respectively). It is concluded that Bacillus licheniformis is capable of producing multiple cellulo- and hemicellololytic enzymes for bioethanol production using cost-effective agricultural residues, especially CM, as a sole nutrient source.

Hemato-biochemical and Cortisol Profile of Holstein Growing-calves Supplemented with Vitamin C during Summer Season.

Effect of vitamin C (VC) on biochemical, hematological and cortisol profile of growing Holstein calves during summer was investigated. Eighteen calves between 14 and 16 weeks of age were divided equally into two groups. One group received a diet supplemented with VC (20 g/d) for 60 days, while other non-supplemented diet fed group served as a control (CON). The temperature humidity index (THI) was recorded and computed during the experiment. From days 0 to 60, the THI exceeded 70. Blood samples were collected from the jugular vein of each calf at days 0, 15, 30, 45 and 60. Serum albumin and total protein decreased (p<0.05) in CON and VC calves with age. Serum glutamic-oxaloacetic transaminase concentrations were not affected by treatments. Serum creatinine, albumin and glutamic-pyruvic transaminase concentrations were higher in calves in the VC group than the CON group. While red blood cells, hemoglobin and hematocrit were lower (p<0.05) in VC calves, mean corpuscular volume, mean corpuscular hemoglobin, red blood cell distribution width and mean platelet volume were higher (p<0.05) in these VC supplemented calves. Leukocyte parameters including white blood cells and full term for lymphocytes were not affected by the treatments. Also, serum cortisol was not affected by treatments. At day 15, 30 and 45, the total VC in plasma was higher (p<0.05) in calves fed with VC. In conclusion, serum cortisols were not affected by plasma VC concentration, while some blood parameters were positively influenced in calves fed with VC.

Analysis of the laser transmission rate of silicon (Si) applied to flip-chip bonding

The present study explored a flip-chip packaging method where transmission bonding is performed using the laser beam transmission rate of Si, the main material of flip chips. Here, the transmission of Si by a laser beam using laser wavelength in the IR domain (1,064 nm) was demonstrated through experiments. Further experiments were then conducted where the results were applied to actual flip chip bonding. The mechanical properties of the flip-chip solder joints were analyzed through experiments, and the degree of thermal effect was analyzed through simulation. The results showed that, in flip chip bonding, laser transmission bonding was advantageous in mechanical, thermal, and temporal terms relative to conventional bonding (thermo-compression).

Development of 3-D shapes estimation by using single X-ray image

X-ray images are heavily affected by noise which makes normal image processing not workable. This paper suggested a new method to identify the primary 3-D shape of an embedded object and its pose by using only single X-ray image. The image feature consists of corner points and edge/intersection lines of adjacent surfaces. The intensity of an X-ray image is attenuated exponentially with increasing the penetration thickness. The main finding is to model a precise exponential relationship to fit the variation of X-ray image intensity. It applied a least-square-method to the X-ray projection image and effectively extracted edges and intersection lines from the noise of X-ray image.

A study on optimization design of Ultrasonic Bonding Machine

Our life has many electronic products and its use getting increase sharply in the future. For this reason, importance of semiconductors packaging technology with small size, multi function has been a steady increase every day. So flip chip interconnection technology to satisfy the requirements is realized very important technology by many researchers and various study of the flip chip interconnection technologies such as process and technology of bonding, bumping and UBM process etc. are going on actively. The technology of bonding is classified into bonding process as thermo compression bonding, ultrasonic bonding and laser bonding. In this paper flip chip bonding machine using ultrasonic bonding process technology is developed. The bonding machine which can bond gold to gold and gold to aluminum using 40 kHz ultrasonic. The machine is semi auto ultrasonic flip chip bonding machine. It consists of three units: 1. Bonding head unit of accurate structure for reliability 2. Panel stage unit of accurate actuator structure for velocity and force control 3. Align Camera unit consist of 2 CCD camera module and mirror type for align of COG.

Edge extraction in X-ray image based on COD of materials

We have performed a single X-ray image extract of three-dimensional shape information (edges and vertex) by using characteristics of a specific material with a specific size (thickness). We have used that fact that the intensity distribution X-ray images decreases around edge areas in the form of exponential function and used the least square method and the coefficient of determination value to extract edges. Here we could infer the effect of the penetration rate of X-ray on the coefficient of determination value according to the kind of material (Zn, Ti, A, and Si) and that the penetration rate and the coefficient of determination value are inversely proportional. We could also conclude the effect of the penetration rate of X-ray on the coefficient of determination value according to the size of the material (5, 10, 15mm) differs and the size and the coefficient of determination value are proportional.

Sensor system for linear defect tracking by using cone-shaped laser beam

A sensor system that measures the 3D data of the object after projecting the cone shaped beam to the object of measurement to create a round mark and receiving this image through camera, was studied. This sensor system, when attached to a robot, will enable diverse application works, and in this study, such was proved by displaying the tracking work for the defect fabricated randomly.

Detection of shape error through solder bump edge extraction of flip-chip by using exponential approximation function

As the technology of semi-conductor chip progresses to pursue high density and high speed, flip-chip technology recently has played a successful role to overcome technological limit of the existent gold wire bonding technology made a connection with outside terminal. Flip-chip is systemically different to the existent chip that transfers electrical signal by connecting wires to the chip externally. Because the interior connecting part of flip-chip is hidden into an invisible region between a die and a PCB, it is indispensable for preparing cut or sliced chips to observe inner joint parts. Therefore, this work embodied nondestructive inspection system that can examine the bonding part of flip-chip without damage of chip using an X-ray system. Using an attenuation characteristic of X-ray (the intensity after transmitting an X-ray), it could do monitoring the shape of solder bumps without damaging the chip. The suggested inspection method can effectively extract the edge of solder bumps from an X-ray image by using the exponential approximation for the intensity of transmitting an X-ray and detect inside bad bonding parts utilizing information about shape. The embodied inspection system is applied to evaluate actual bonded flip-chip.