• Transactions of Materials Processing
• /
• v.29 no.5
• /
• pp.265-271
• /
• 2020

The purpose of this paper is to analyze the numerical simulation accuracy according to the CFRP modeling method in the CFRP-Al alloy SPR (Self-Piercing Rivet) joint process. The mechanical properties of the CFRP, aluminum sheet are precisely obtained from the tensile test according to the loading direction. Additionally, the hardening curve of rivet was calculated from the inverse analysis of the machined rivet-ring compression test. For the CFRP-Al alloy SPR simulation, two kinds of the CFRP modeling methods were established based on the continuum and layer-by-layer approaches. The simulation results showed that the CFRP layer-by-layer modeling method can provide more reliable prediction shape of the fractured sheets and deformed rivet. This simulation technique can be used in evaluating the CFRP-Metal SPR performance and designing the SPR process conditions.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.305-305
• /
• 2011

표면 플라즈몬 공진(SPR) 현상을 이용한 광섬유 센서는 SPR 센서의 우수한 표면 민감도, 비표지 검출능 등의 특징은 유지하면서 측정시스템이 단순해지고 저렴하게 제작이 가능하며 원거리 검출에 유리하다는 장점으로 많은 연구가 진행되고 있다. 최근 스택 제어가 용이하고 민감도 또한 우수하다는 이유로 측면 연마형 센서 구조를 적용한 연구가 많이 이루어지고 있다. 본 연구에서는 기존 Kretchman형태의 SPR 센서의 분해능 향상을 위해 사용된 광도파로 구조를 측면 연마형 광파이버에 적용시켰다. 금속 층 / 유전체 층 / 금속 층으로 구성되어 있는 광도파로 구조와 Au 단일 층을 사용한 기존 구조에 대한 이론 전사모사를 진행하고 실물 소자를 제작하여 특성을 평가하였다. WCSPR 센서에서는 두 개의 반사율 dips이 나타난다. 하나는 단파장영역에서 나타나는 폭이 작은 형태이며 또 다른 하나는 장파장영역에서 나타나는 폭이 넓은 형태이다. 단파장에서의 dip은 입사각에 크게 영향을 받지 않기 때문에 Wavelength interrogation mode을 이용하는 광섬유 SPR센서에 적용할 경우 분해능이 향상될 것 이다. WCSPR 센서는 도파로의 유전체층에서 진행되는 모드를 이용하면 Self-referencing을 할 수 있다, 또한 유전체 층의 두께를 변화 시켜 중심파장의 위치를 조절할 수 있는 특징을 갖고 있다. 결과적으로 광도파로 구조를 광파이버에 적용시켜 기존 Au 단일 층 구조의 SPR 센서에 비해 좀 더 정확하고 광범위한 감지를 할 수 있다.

• Journal of Sensor Science and Technology
• /
• v.16 no.6
• /
• pp.401-406
• /
• 2007

In this paper, we fabricated the polymer waveguide type surface plasmon resonance (SPR) sensor using a white light source and optical spectrum analyzer (OSA). Fabricated sensor uses the principle of phase matching between evanescent wave and surface plasmon wave. According to the measuring result, the shift of resonance wavelength conducts the change of the refractive index. The proposed SPR sensor is expected to apply the integrated multichannel SPR sensor and the realtime monitoring system.

• International Journal of Aeronautical and Space Sciences
• /
• v.18 no.3
• /
• pp.414-424
• /
• 2017

This paper introduces an experimental device which can measure accurate aerodynamic forces without support interference in wide experimental region for wind tunnel test of micro aerial vehicles (MAVs). A stereo pattern recognition (SPR) method was introduced to a magnetic suspension and balance system (MSBS), which can eliminate support interference by levitating the experimental model, to establish wider experimental region; thereby MSBS-SPR integrated system was developed. The SPR method is non-contact, highly accurate three-dimensional position measurement method providing wide measurement range. To evaluate the system performance, a series of performance evaluations including SPR system measurement accuracy and 6 degrees of freedom (DOFs) position/attitude control of the MAV model were conducted. This newly developed system could control the MAV model rapidly and accurately within almost 60mm for translational DOFs and 40deg for rotational DOFs inside of $300{\times}300mm$ test section. In addition, a static wind tunnel test was conducted to verify the aerodynamic force measurement capability. It turned out that this system could accurately measure the aerodynamic forces in low Reynolds number, even for the weak forces which were hard to measure using typical balance system, without making any mechanical contact with the MAV model.

• Korean Journal of Microbiology
• /
• v.41 no.1
• /
• pp.87-92
• /
• 2005

Pronase, a protease produced for commercial purpose by Streptomyces griseus, was composed of serine protease, alkaline protease, aminopeptidase and carboxypeptidase complex, and it has been widely used as anti-inflammatory drugs for human therapy. In this study, we developed a new integration vector, pHJ101 derived from pSET152, containing strong promoter, ermE, to overexpress a certain protease gene. Specific PCR primers for cloning of sprA (a gene for S. griseus protease A) and sprB (a gene for S. griseus protease B) genes were designed from the basis of nucleotide sequence in databases and amplified by PCR. Plasmid pHJ201 and pHJ202 were constructed by inserting of amplified each gene in a vector pHJ101. S. griseus HA and S. griseus HB were respectively obtained by conjugal process of a parent strain, S. griseus IFO 13350 with the recombinant Escherichia coli harboring plasmid pHJ201 or pHJ202. When protease activity was measured in flask cultivation, produced protease levels of S. griseus HA and S. griseus HB increased about 5.3 times and 5 times, respectively, more than that of parent strain. And, the constructed integrating plasmid pHJ101 was applicable for overexpression of a certain gene in Streptomyces sp.

• Journal of the Korean Society of Safety
• /
• v.29 no.4
• /
• pp.9-14
• /
• 2014

Self-piercing riveting(SPR) is a mechanical fastening technique which is put pressure on the rivet for joining the sheets. Unlike a spot welding, SPR joining does not make the harmful gas and $CO_2$ and needs less energy consumption. In this study, static and fatigue tests were conducted using tensile-shear specimens with Al-5052 plates for evaluation of fatigue strength of the SPR joints. During SPR joining process for the specimen, using the current sheet thickness and a rivet, the optimal applied punching force was found to be 21 kN. And, the maximum static strength of the specimen produced at the optimal punching force was 3430 N. During the fatigue tests for the specimens, interface failure mode occurred on the top substrate close to the rivet head in the most high-loading range region, but on the bottom substrate close to the rivet tail in the low -loading range region. There was a relationship between applied load amplitude $P_{amp}$ and lifetime of cycle N for the tensile-shear, $P_{amp}=3395.5{\times}N^{-0.078}$. Using the stress-strain curve of the Al-5052 from tensile test, the simulations for fatigue specimens have been carried out using the implicit finite element code ABAQUS. The relation between von-Mises equivalent stress amplitude and number of cycles was found to be ${\sigma}_{eq}=514.7{\times}N^{-0.033}$.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.4
• /
• pp.364-369
• /
• 2002

Streptomyces shows a eukaryotic characteristic that vegetative cell can grow into mycelial form and has morphological and physiological differentiation at a certain period during its life cycle. Streptomyces has been used for the production of many biologically active compounds, such as antibiotics and pronase. Production of second metabolites and differentiation of the vegetative cell share the certain period of its lift cycle. Therefore, second metabolites may affect the differentiation of the vegetative cell. One of the microbial hormone, called A-factor, regulates the production of second metabolites, sporulation and differentiation of the cells. Streptomyces griseus produces streptomycin as well as many different kinds of proteinase. As mentioned, period of proteinases production overlaps with the period of differentiation of the vegetative cells. Protease may play a important role for the differentiation of the cells. In this paper, function of the SGPD gene cloned from S. griseus IFO 13350 tested whether it affects for the differentiation of A-factor mutated S. griseus HH1 and S. griseus IFO13350. pWHM3 and pWHM3-sprD plasmid was transformed into S. griseus HH1 and S. griseus IFO13350. Chymotrypsin activity of the cultured medium of the transformants with pWHM3-sprD plasmid didn't show any change with that of the transformants with plasmid only. The transformants with pWHM3-sprD plasmid didn't show the increase of the production of actinorhodin as well as morphological change in S. griseus IFO 13350 and HH1, as well. The promoter sequences of the SGPA and SGPB gene which encode chymotrypsin-like protease, were compared with that of SGPD gene. Regulatory mechanism of gene expression of proteinase genes will be studied for the development of high production system for protease as well as the function of the proteases.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.11
• /
• pp.1595-1600
• /
• 2011

Sugarcane press residue (SPR), a byproduct from the sugar industry was evaluated for it's nutrient and energetic quality in broilers and layers. The composition of SPR included (% DM): CP-11.76 (methionine-2.21, cystine-1.05, lysine-4.85, threonine-5.48% of CP), EE-7.87 (palmitic acid-30.3, stearic acid-4.1, oleic aicd-17.2, linoleic acid-38.0, linolenic acid-5.4% of EE), CF-10.08, TA-21.08 (Ca-3.87, P-1.10, Mg-0.95%, Fe-3500, Mn-284, Zn-113, Cu-61.5, Co-5.0 ppm and AIA-4.93%) and NFE-48.35% indicating that SPR is a valuable source of both organic and inorganic nutrients for poultry. The metabolic trials revealed the average ME of SPR as 749, 842 and 1,270 kcal/kg, respectively in broilers and 844, 936 and 1,031 kcal/kg in layers, at 10, 20 and 30% inclusion levels, respectively. Further, the fortification of SPR incorporated diets with biotechnological products viz., lipid utilizing agents (lipase and lecithin) or NSP degrading enzymes and their combination did not improve the ME content of such diets.

• Journal of Life Science
• /
• v.13 no.1
• /
• pp.99-104
• /
• 2003

Aromatic compounds are of major concern among environmental pollutants due to their toxicity and persistence. To monitor aromatic compounds in a real time with a better sensitivity, a new method of SPR (surface plasmon resonance) based on DNA chip (Biacore 3000) was developed here. It is thought that CapR regulatory protein as a complex with phenol, could bind to their corresponding promoter, Po. Biotinylated DNA oligomers for the promoter was synthesized by PCR and coupled onto streptoavidin-linked CM5-chip. CapR regulatory proteins were purified after cloning their genes in pET21a (+) vector and expressing proteins. The interaction was assessed by the system where the regulatory proteins flowed with or without phenol through the cells of DNA chip. CapR regulatory protein even in the presence of phenol had no response to its promoter, Po, suggesting that other factor(s) might be required for the activation of Po promoter. The present work reveals a promising possibility of the SPR-based DNA chip in monitoring specific environmental pollutants in a real time.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.8
• /
• pp.568-574
• /
• 2015

The present study was conducted by using stereo pattern recognition method(SPR method) to measure the displacement and vibration of an airplane wing in flight condition. A SPR based measurement system was developed using two visible light stereo cameras. The visible light stereo images were processed to obtain marker points by adaptive threshold method and marker filtering technique. The marker points were used to reconstruct 3D point, displacement, and vibration data. The SPR system was installed on F-16 fighter. The wing displacement and vibration were measured in flight condition. Therefore, this paper presents a possibility that SPR based measurement system using visible light stereo camera can be very useful for measuring displacement and vibration of an airplane in flight condition.