• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.525-525
• /
• 2013

Low temperature plasma diagnosis is one of the big issues in laboratory scale or processing industry. One of the most powerful techniques of plasma diagnostics is the use of the scattering of electromagnetic radiation from the plasma. Electron temperature and density are important parameters for understanding the information of plasmas in the plasma processing industry. Laser scattering experiments on plasma can provide a substantial amount of information about plasma parameters such as the electron density ne, the electron temperature Te, and the neutral density nn and temperature Tn. Thomson scattering spectroscopy is used several method, in accordance with detector type. Commonly, Thomson scattering is used several notch filter to separate expanded wavelength. Since using a spectrometer with surface relief grating or notch filter, the system of the measurement will be complicated and bigger. In this study, using VPHG (Volume Phase Holographic Grating) in order to install the simple and cheap system. VPHG has the advantage of the system installation, because it can be Transmission Type. The diffraction efficiency and dispersion angle of VPHG is higher than the surface relief grating relatively. For a wavelength and bandwidth selection, Using a slit or mask to select a rejection wavelength instead of notch filter.

• Animal Bioscience
• /
• v.34 no.12
• /
• pp.2003-2011
• /
• 2021

Objective: The aim of this study was to evaluate the effect of marinating turkey meat with buttermilk and acid whey on the technological traits and microbiological quality of the product. Methods: Slices of turkey meat muscles were marinated for 12 hours in buttermilk (n = 30), acid whey (n = 30) and comparatively, in lemon juice (n = 30). The control group (n = 30) consisted of unmarinated slices of turkey breast muscles. Physical parameters (pH, water holding capacity, colour L^*a^*b^*, shear force, weight loss) were assessed and quantitative and qualitative microbiological evaluation of raw and roasted products was performed. The microbiological parameters were determined as the total viable counts of mesophilic aerobic bacteria, of the Enterobacteriaceae family, and Pseudomonas spp. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Marinating turkey meat in buttermilk and whey compared to marinating in lemon juice and the control sample resulted in a higher (p<0.05) degree of yellow color saturation (b^*) and a reduction (p<0.05) in the number of mesophilic aerobic bacteria, Pseudomonas spp. and Enterobacteriaceae family as well as the number of identified mesophilic aerobic bacteria in both raw and roasted samples. The lowest (p<0.05) shear force values were found in products marinated in whey. Conclusion: The use of buttermilk and acid whey as a marinade for meat increases the microbiological safety of the product compared to marinating in lemon juice, while maintaining good technological features of the product.

• Current Optics and Photonics
• /
• v.7 no.6
• /
• pp.721-731
• /
• 2023

This paper studies various roughness parameters, besides waviness, texture, and nonlinear parameters of Bismarck brown Y (BBY)-doped Poly(methyl methacrylate) (PMMA) films based on the computed values of optical limiting (OL) threshold power and nonlinear refractive index. The films' morphology, grain size, and absorption spectra were investigated using atomic force microscopy in conjunction with ultraviolet-visible (UV-Vis) spectrophotometer. The particle size of the films ranged between 4.11-4.51 mm and polymer films showed good homogeneity and medium roughness, ranging from 1.11-4.58 mm. A polymer film's third-order nonlinear optical features were carried out using the Z-scan methodology. The measurements were obtained by a continuous wave produced from a solid-state laser with a 532 nm wavelength. According to the results, BBY has a nonlinear refractive index of 10^-6 cm²/W that is significantly negative and nonlinear. The optical limiting thresholds are roughly 10.29, 13.52, and 18.71 mW, respectively. The shift of nonlinear optical features with the film's concentration was found throughout the experiment Additionally, we found that the polymer samples have outstanding capabilities for restricting the amount of optical power that may be transmitted through them. We propose that these films have the potential to be used in a wide variety of optoelectronic applications, including optical photodetectors and optical switching.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.8
• /
• pp.632-637
• /
• 2010

The measurement of contact wire wear in electric railways is one of the key test parameters to increase speed and maintain safety in electric railways. Wear caused by continuous interaction between pantographs and contact wires has a negative effect on current collection quality and severely damaged contact wires might cause hazardous accidents. This paper introduces a non-contact optical-based contact wire wear measuring system that will replace conventional wear detecting methods conducted by maintenance vehicles or workers. The system is implemented by high-speed cameras that can collect images of contact wires during vehicle operation, a laser used to create images profile of the contact wire surface, and a computer used to process the collected images. The proposed system is designed to assist maintenance of overhead contact lines by creating geometrically plotted images of contact wires to detect contact wire wear during operation on conventional lines or high-speed lines.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.1
• /
• pp.35-46
• /
• 2004

In comparison with edge-emitting lasers(EELs), predicting the output power and slope efficiency of Vertical-Cavity Surface-Emitting Lasers(VCSELs) is very difficult due to the absorption loss in DBR layers. However, by using transfer matrix method(TMM), we've made possible to calculate such parameters of multi-layer structures like VCSELs. In this paper, we've calculated the threshold gain, threshold current and slope efficiency through the methodology based on TMM. Also TMM is the way of customizing the VCSEL structure for the desired threshold current and slope efficiency by changing the number of DBR mirror layers.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.4
• /
• pp.569-577
• /
• 2018

In this paper, with the aid of information which is included within data, preprocessing algorithm-based black plastic classifier is designed. The slope and area of spectrum obtained by using laser induced breakdown spectroscopy(LIBS) are analyzed for each material and its ensuing information is applied as the input data of the proposed classifier. The slope is represented by the rate of change of wavelength and intensity. Also, the area is calculated by the wavelength of the spectrum peak where the material property of chemical elements such as carbon and hydrogen appears. Using informations such as slope and area, input data of the proposed classifier is constructed. In the preprocessing part of the classifier, Principal Component Analysis(PCA) and fuzzy transform are used for dimensional reduction from high dimensional input variables to low dimensional input variables. Characteristic analysis of the materials as well as the processing speed of the classifier is improved. In the condition part, FCM clustering is applied and linear function is used as connection weight in the conclusion part. By means of Particle Swarm Optimization(PSO), parameters such as the number of clusters, fuzzification coefficient and the number of input variables are optimized. To demonstrate the superiority of classification performance, classification rate is compared by using WEKA 3.8 data mining software which contains various classifiers such as Naivebayes, SVM and Multilayer perceptron.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.2
• /
• pp.158-165
• /
• 2008

The carbon dioxide properties change sharply near the critical or pseudo-critical point in the heat transfer processes. The reduction in turbulent, convective heat transfer parameters observed in some supercritical data and in experiments with common gases can be due to property variation, acceleration, buoyancy or combinations of these phenomena, depending on the conditions of the applications. In this study, the measurement for the secondary flow driven by buoyancy was carried out on the supercritical carbon dioxide turbulent flows in the different boundary condition with the constant mass flow rate. The available measuring techniques were used to clarify the behaviour of any supercritical fluid. Laser Doppler Velocimeter (LDV) and a special device was used to measure the secondary velocity and turbulent characteristics of the supercritical flows.

• Korean Journal of Optics and Photonics
• /
• v.20 no.1
• /
• pp.41-47
• /
• 2009

We report the spectral characteristics of Multimode Interferometer (MMI)-coupled semicondoctor square ring resonators. The epitaxial layers of the proposed semiconductor ring resonator consists of $1.55{\mu}m$ GaInAsP-InP multiple quantum wells. The lasing characteristics were observed by varying the structure parameters of the MMI-coupled square ring resonators. It is concluded that the MMI-coupled scheme selects a single spectral lasing mode in the double square ring cavities.

• Korean Journal of Optics and Photonics
• /
• v.8 no.4
• /
• pp.260-266
• /
• 1997

Holographic optical elements for polarization separation (HPS) are fabricated in a dichromated gelatin(DCG) thin film of 7${\mu}{\textrm}{m}$ thickness. The polarization properties of HPS is characterized by measuring diffraction efficiency with several physical parameters like exposure time, incident angle and read-out polarization angles. The experimental data are compared with theoretical results based on Kogelnik's coupled wave theory, which shows good agreement. It is also found that the HPS element has a very high extinction ratio of polarization over 500:1 for S and P polarizations, respectively, with He-Ne laser wavelength. We also propose an optical switch optical interconnects by using HPS elements.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.45-46
• /
• 2003

A process control system has been developed for measurement and characterization of the nanofiber web qualities. The nano-fiber information system (NAFIS) developed consists of a measurement device and an analysis algorithm, which are a microscope-laser sensor fusion system and a process information system, respectively. It has been found that NAFIS is so successful in detecting irregularities of pore and diameter that the resulting product has been quitely under control even at the high production rate. Pore distribution, fiber diameter and mass uniformity have been readily measured and analyzed by integrating the non-contact measurement technology and the random function-based time domain signal/image processing algorithm. Qualifies of the nano-fiber webs have been revealed in a way that the statistical parameters for the characteristics above are calculated and stored in a certain interval along with the time-specific information. Quality matrix, scale of homogeneity is easily obtained through the easy-to-use GUI information. Finally, ANFIS has been evaluated both for the real-time measurement and analysis, and for the process monitoring.