• 제목/요약/키워드: Fourier transform

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A Study on the Identification of Animal Hair in Food (식품 중 동물 털 이물의 판별법 연구)

  • Lee, Jae-Hwang;Park, Young-Eun;Lim, Byung-Chul;Kim, Ju-Shin;Choi, Jong-Hyun;Kang, Tae Sun;Lee, Jin-Ha;Kwon, Kisung
    • Journal of Food Hygiene and Safety
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    • v.32 no.1
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    • pp.57-63
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    • 2017
  • Foreign materials with a variety of types and sizes are found in food; thus, extraordinary efforts and various analytical methods are required to identify the types of foreign materials and to find out accurate causes of how they unintentionally enter food. In this study, human, cow, pig, mouse, duck, goose, dog, and cat were chosen as various types of animal hairs because they can be frequently incorporated into food during its production or consumption step. We morphologically analyzed them using stereoscopic, optical, SUMP method, and scanning electron microscopes, showing differences in each type. In addition, X-ray fluorescence spectrometer (XRF) was used to analysis chemical compositions ($^{11}Na{\sim}^{92}U$, Mass%) of samples. As a result, we observed that mammalian hairs were mainly composed of sulfur. Organic compounds of samples were further analyzed by fourier transform infrared spectroscopy (FT-IR) that can compare spectra of given materials; however, this method did not show significant differences in each sample. In this study, we suggest a rapid method for the identification of the causes and types of foreign materials in food.

Kinetics and Mechanism of the Oxidation of Alcohols by C9H7NHCrO3Cl (C9H7NHCrO3Cl에 의한 알코올류의 산화반응에서 속도론과 메카니즘)

  • Park, Young-Cho;Kim, Young-Sik;Kim, Soo-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.378-384
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    • 2018
  • $C_9H_7NHCrO_3Cl$ was synthesized by reacting $C_9H_7NH$ with chromium (VI) trioxide. The structure of the product was characterized by FT-IR (Fourier transform infrared) spectroscopy and elemental analysis. The oxidation of benzyl alcohol by $C_9H_7NHCrO_3Cl$ in various solvents showed that the reactivity increased with increasing dielectric constant(${\varepsilon}$) in the following order: DMF (N,N'-dimethylformamide) > acetone > chloroform > cyclohexane. The oxidation of alcohols was examined by $C_9H_7NHCrO_3Cl$ in DMF. As a result, $C_9H_7NHCrO_3Cl$ was found to be an efficient oxidizing agent that converts benzyl alcohol, allyl alcohol, primary alcohols, and secondary alcohols to the corresponding aldehydes or ketones (75%-95%). The selective oxidation of alcohols was also examined by $C_9H_7NHCrO_3Cl$ in DMF. $C_9H_7NHCrO_3Cl$ was the selective oxidizing agent of benzyl, allyl and primary alcohol in the presence of secondary ones. In the presence of DMF with an acidic catalyst, such as $H_2SO_4$, $C_9H_7NHCrO_3Cl$ oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, and $m-NO_2$). Electron donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (${\rho}$) was -0.69 (308K). The observed experimental data were used to rationalize hydride ion transfer in the rate-determining step.

Manufacturing Techniques of a Backje Gilt-Bronze Cap from Bujang-ri Site in Seosan (서산 부장리 백제 금동관모의 제작기법 연구)

  • Chung, Kwang Yong;Lee, Su Hee;Kim, Gyongtaek
    • MUNHWAJAE Korean Journal of Cultural Heritage Studies
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    • v.39
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    • pp.243-280
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    • 2006
  • At the Bujang-ri Site, Seosan, South Chungcheong Province, around 220 archaeological features, including semi-subterranean houses and pits of Bronze Age and semi-subterranean houses, pits, and burials of Baekje period had been identified and investigated. In Particular, mound burials No. 5 of 13 of Baekje mound burials yielding a gilt-bronze cap along with other valuable artifacts drew international scholarly attention. The gilt-bronze cap from the mound burial No. 5 is a significant archaeological data not only in the study of Baekje archaeology but also in the study of international affairs and exchange at that time. At the time of exposure, the gilt-bronze cap was already broken into a number of pieces and seriously damaged by corrosion, and hardening and urethane foam were necessary in the process of collecting its pieces. Ahead of main conservational treatments on cap, X-ray photograph and CT(computerizes tomography) were taken in order to examine interior structure of the cap and to decide appropriate treatments. In the five layers identified in the profile of cap, a textile layer was set between a metal and a layerof bark of paper birch for avoiding direct contact of the metal and the bark of paper birch. Analyses were executed for examining textile layer and a layer of fibroid material. According to microscopic analysis, while the textile layer consisted of the simplest plain fabric with one fold among three kinds of textile structures, the layer of fibroid material was mixed with two or three kinds of fibers. A comparative analysis with standard sample using FT-IR (Fourier Transform Infrared Spectroscopy) announced that both textiles and fabrics were hemp. Analysis of kind of the paper birch resulted in barks of paper birch with 15 fold. A metallographic microscope, SEM, and WDS were used for the analysis of microscopic structures of plated metal pieces. While amalgam plating was treated as a plating method, the thickness of the plated layer, a barometer of plating technique, was ranged from $1.72{\mu}m$ to $8.67{\mu}m$. The degree of purity of gold (Au) used in plating was 98% in average, and less than 1% of silver (Ag) was included.

Chemical Structure of Ozonized Waste Cooking Oil and Wood Bonding Strengths of Reaction Products with pMD (오존 처리한 폐식용유의 화학구조와 pMDI로 제조한 접착제의 목재 접착강도)

  • Kang, Chan-Young;Lee, Eung-Su;Ryu, Jae-Yun;Lee, Hyun-Jong;Seo, Jun-Won;Park, Heon
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.4
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    • pp.316-322
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    • 2010
  • The research attempted to develop a wood adhesive based on waste cooking oil, using ozonification technology for the chemical structure modification. The waste cooking oil (WCO) was reacted with $O_3$ for different times; 1 h, 2 h, and 3 h. The chemical structure modifications of the ozonized WCOs were examined by Fourier transform Infrared (FT-IR) spectrum. The FT-IR spectrum of WCO had an absorbance peak at 3,010 $cm^{-1}$ that was the characteristic peak of the unsaturated double bonds. As ozone treatment time increased, the peak of the double bond was disappeared and carboxyl peak appeared at 1,700 $cm^{-1}$. Especially, the double bond of 3 hrs-ozonized WCO was vanished almost. In results of the dry bonding strengths of the 3 hrs-ozonized WCO mixed with polymeric methylene diphenyl diisocyanate (pMDI) were the strengths of weight ratio of 3hrs-ozonized WCO : pMDI, 1 : 0.5, 8.08 kgf/$cm^2$, 1 : 0.75, 9.53 kgf/$cm^2$ 1 : 1, 44.16 kgf/$cm^2$, 1 : 2, 58.08 kgf/$cm^2$, 1 : 3, 61.41 kgf/$cm^2$, and 1 : 4, 46.95 kgf/$cm^2$. Therefore, it was found that the optimum equivalent ratio was formed at the ratio of 1 : 2 or 1 : 3. Under wetting the bonding strength of 1 : 3 ratio was appeared higher than that of 1 : 2 ratio, while the results obtained from hot-water and cyclic boiling shear test were similar.

Characterization of SEI layer for Surface Modified Cathode of Lithium Secondary Battery Depending on Electrolyte Additives (전해질 첨가제에 따른 graphite 음극의 SEI분석 및 전기 화학적 특성 고찰)

  • Lee, Sung Jin;Cha, Eun Hee;Lim, Soo A
    • Journal of the Korean Electrochemical Society
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    • v.19 no.3
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    • pp.69-79
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    • 2016
  • Lithium ion battery with high energy density is expanding its application area to electric automobile and electricity storage field beyond existing portable electric devices. Such expansion of an application field is demanding higher characteristic and stable long life characteristic of an anode material, the natural graphite that became commercialized in lithium ion battery. This thesis produced cathode by using natural graphite anode material, analyzed creation of the cathode SEI film created due to initial reaction by using electrolyte additives, VC (vinylene carbonate), VEC (vinyl ethylene carbonate), and FEC (fluoroethylene carbonate), and considered correlation with the accompanying electrochemical transformation. This study compared and analyzed the SEI film variation of natural graphite cathode according to the electrolyte additive with SEI that is formed at the time of initial filling and cathode of $60^{\circ}C$ life characteristic. At the time of initial filling, the profile showed changes due to the SEI formation, and SEI was formed in No-Additive in approximately 0.9 V through EVS, but for VC, VEC, and FEC, the formation reaction was created above 1 V. In $60^{\circ}C$ lifespan characteristic evaluation, the initial efficiency was highest in No-Additive and showed high contents percentage, but when cycle was progressed, the capacity maintenance rate decreased more than VC and FEC as the capacity and efficiency at the time of filling decreased, and VEC showed lowest performance in efficiency and capacity maintenance rate. Changes of SEI could not be verified through SEM, but it was identified that as the cycle of SEI ingredients was progressed through FT-IR, ingredients of Alkyl carbonate ($RCO_2Li$) affiliation of the $2850-2900cm^{-1}$ was maintained more solidly and the resistance increased as cycle was progressed through EIS, and specially, it was identified that the resistance due to No-Additive and SEI of VEC became very significant. Continuous loss of additives was verified through GC-MS, and the loss of additives from partial decomposition and remodeling of SEI formed the non-uniform surface of SEI and is judged to be the increase of resistance.

Effect of Acrylic Acid on the Physical Properties of UV-cured Coating Films for Metal Coating (금속코팅용 광경화 코팅필름의 물성에 대한 아크릴산(Acrylic acid)의 영향)

  • Seo, Jong-Chul;Choi, Jun-Suk;Jang, Eui-Sung;Seo, Kwang-Won;Han, Hak-Soo
    • Korean Chemical Engineering Research
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    • v.49 no.1
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    • pp.75-82
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    • 2011
  • Five different composition UV-cured poly(urethane acrylate-co-acrylic acid) (PU-co-AA) films have been prepared by reacting isophorone diisocyanate(IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), and different weight ratio trimethylolpropane triacrylate(TMPTA) and acrylic acid(AA) as diluents, and characterized using a Fourier transform infrared spectroscopy(FT-IR). The adhesion properties onto the stainless steel, morphology, mechanical hardness, and electrical property of UV-cured PU-co-AA films were investigated as a function of acrylic acid(AA) content. All the PU-co-AA films are structure-less and the molecular ordering and packing density decreased with increasing content of AA due to the flexible structure and -COOH side chains in AA. The crosscut test showed that PU-co-AA films without AA and with low content of AA showed 0% adhesion(0B) and the adhesion of PU-co-AA films in the range of 40-50% AA increased dramatically as the content of AA increases. The pull-off measurements showed that the adhesion force of PU-co-AA films to stainless steel substrate varied from 6 to 31 kgf /$cm^2$ and increased linearly with increasing AA content. The mechanical hardness also decreased as the content of AA increases. This may come from relatively linear and flexible structure in AA and low crystallinity in PU-co-AA films with higher content of AA. The higher AA-containing PU-co-AA films showed higher dielectric constant due to the increase of polarization by introducing AA monomer. In conclusion, the physical properties of UV-cured PU-co-AA films are strongly dependent upon the content of AA and the incorporation of AA in polyurethane acrylate is very useful way to increase the adhesion strength of UV-curable polymers on the stainless steel substrate.

A hybrid algorithm for the synthesis of computer-generated holograms

  • Nguyen The Anh;An Jun Won;Choe Jae Gwang;Kim Nam
    • Proceedings of the Optical Society of Korea Conference
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    • pp.60-61
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    • 2003
  • A new approach to reduce the computation time of genetic algorithm (GA) for making binary phase holograms is described. Synthesized holograms having diffraction efficiency of 75.8% and uniformity of 5.8% are proven in computer simulation and experimentally demonstrated. Recently, computer-generated holograms (CGHs) having high diffraction efficiency and flexibility of design have been widely developed in many applications such as optical information processing, optical computing, optical interconnection, etc. Among proposed optimization methods, GA has become popular due to its capability of reaching nearly global. However, there exits a drawback to consider when we use the genetic algorithm. It is the large amount of computation time to construct desired holograms. One of the major reasons that the GA' s operation may be time intensive results from the expense of computing the cost function that must Fourier transform the parameters encoded on the hologram into the fitness value. In trying to remedy this drawback, Artificial Neural Network (ANN) has been put forward, allowing CGHs to be created easily and quickly (1), but the quality of reconstructed images is not high enough to use in applications of high preciseness. For that, we are in attempt to find a new approach of combiningthe good properties and performance of both the GA and ANN to make CGHs of high diffraction efficiency in a short time. The optimization of CGH using the genetic algorithm is merely a process of iteration, including selection, crossover, and mutation operators [2]. It is worth noting that the evaluation of the cost function with the aim of selecting better holograms plays an important role in the implementation of the GA. However, this evaluation process wastes much time for Fourier transforming the encoded parameters on the hologram into the value to be solved. Depending on the speed of computer, this process can even last up to ten minutes. It will be more effective if instead of merely generating random holograms in the initial process, a set of approximately desired holograms is employed. By doing so, the initial population will contain less trial holograms equivalent to the reduction of the computation time of GA's. Accordingly, a hybrid algorithm that utilizes a trained neural network to initiate the GA's procedure is proposed. Consequently, the initial population contains less random holograms and is compensated by approximately desired holograms. Figure 1 is the flowchart of the hybrid algorithm in comparison with the classical GA. The procedure of synthesizing a hologram on computer is divided into two steps. First the simulation of holograms based on ANN method [1] to acquire approximately desired holograms is carried. With a teaching data set of 9 characters obtained from the classical GA, the number of layer is 3, the number of hidden node is 100, learning rate is 0.3, and momentum is 0.5, the artificial neural network trained enables us to attain the approximately desired holograms, which are fairly good agreement with what we suggested in the theory. The second step, effect of several parameters on the operation of the hybrid algorithm is investigated. In principle, the operation of the hybrid algorithm and GA are the same except the modification of the initial step. Hence, the verified results in Ref [2] of the parameters such as the probability of crossover and mutation, the tournament size, and the crossover block size are remained unchanged, beside of the reduced population size. The reconstructed image of 76.4% diffraction efficiency and 5.4% uniformity is achieved when the population size is 30, the iteration number is 2000, the probability of crossover is 0.75, and the probability of mutation is 0.001. A comparison between the hybrid algorithm and GA in term of diffraction efficiency and computation time is also evaluated as shown in Fig. 2. With a 66.7% reduction in computation time and a 2% increase in diffraction efficiency compared to the GA method, the hybrid algorithm demonstrates its efficient performance. In the optical experiment, the phase holograms were displayed on a programmable phase modulator (model XGA). Figures 3 are pictures of diffracted patterns of the letter "0" from the holograms generated using the hybrid algorithm. Diffraction efficiency of 75.8% and uniformity of 5.8% are measured. We see that the simulation and experiment results are fairly good agreement with each other. In this paper, Genetic Algorithm and Neural Network have been successfully combined in designing CGHs. This method gives a significant reduction in computation time compared to the GA method while still allowing holograms of high diffraction efficiency and uniformity to be achieved. This work was supported by No.mOl-2001-000-00324-0 (2002)) from the Korea Science & Engineering Foundation.

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Estimation of cremation temperature on Baekje human bones from Seoul Seokchon-dong Ancient Tomb No.1 using XRD and FT-IR analysis (XRD와 FT-IR을 이용한 백제시대 옛사람 뼈의 화장(火葬) 온도 추정 - 서울 석촌동 고분군 1호 매장의례부 출토 옛사람 뼈를 중심으로 -)

  • YU, Jia;PARK, Serin;SHIN, Jiyoung
    • MUNHWAJAE Korean Journal of Cultural Heritage Studies
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    • v.54 no.3
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    • pp.228-241
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    • 2021
  • Cremated archaeological bones provide crucial information to unravel the details of ancient cremation events and funeral culture. The research on cremated bones to date has been mainly focused on extracting archaeological information in Korea. Recently, the techniques of physical anthropology have been applied to obtain biological information and cremation temperatures for individuals. This study analyzed human remains excavated from Seoul Seokchon-dong Ancient Tombs and determined whether there were human cremations as well as the estimated cremation temperatures. There was no trace of fire in the pits where cremated bones were found; therefore, it is assumed that they were deposited with the artifacts. In this study, four samples were selected according to the surface color of the bones, and X-ray diffraction analysis (XRD) and Fourier-transformed infrared spectroscopy (FT-IR) were used for analysis. All four of the Seokchon-dong cremated bones were found, based on the crystallization index of X-ray diffraction analysis, to have experienced cremation above the temperature of 700℃. Infrared spectroscopy results indicated that the four bones from Seokchon-dong were cremated at temperatures above 700℃ and below 1,000℃. IR peaks were observed at 700℃, whereas no changes were found when bones experienced more than 1000℃. We assume that the cremated people in the Seokchon-dong Tombs were people of high-status because cremation at such a high temperature at that period required much effort. Here we present significant evidence of the cremation status and temperature of archaeological human bones on the basis of XRD and FT-IR, allowing for the restoration of the cremation events and funeral culture in archaeological sites.

IR Study on the Adsorption of Carbon Monoxide on Silica Supported Ruthenium-Nickel Alloy (실리카 지지 루테늄-니켈 합금에 있어서 일산화탄소의 흡착에 관한 IR 연구)

  • Park, Sang-Youn;Yoon, Dong-Wook
    • Applied Chemistry for Engineering
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    • v.17 no.4
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    • pp.349-356
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    • 2006
  • We have investigated adsorption and desorption properties of CO adsorption on silica supported Ru/Ni alloys at various Ru/Ni mole content ratio as well as CO partial pressures using Fourier transform infrared spectrometer (FT-IR). For Ru-$SiO_{2}$ sample, four bands were observed at $2080.0cm^{-1}$, $2021.0{\sim}2030.7cm^{-1}$, $1778.9{\sim}1799.3cm^{-1}$, $1623.8cm^{-1}$ on adsorption and three bands were observed at $2138.7cm^{-1}$, $2069.3cm^{-1}$, $1988.3{\sim}2030.7cm^{-1}$ on vacumn desorption. For Ni-$SiO_{2}$ sample, four bands were observed at $2057.7cm^{-1}$, $2019.1{\sim}2040.3cm^{-1}$, $1862.9{\sim}1868.7cm^{-1}$, $1625.7cm^{-1}$ on adsorption and two bands were observed at $2009.5{\sim}2040.3cm^{-1}$, $1828.4{\sim}1868.7cm^{-1}$ on vacumn desorption. These absorption bands correspond with those of the previous reports approximately. For Ru/Ni(9/1, 8/2, 7/3, 6/4, 5/5; mole content ratio)-$SiO_{2}$ samples, three bands were observed at $2001.8{\sim}2057.7cm^{-1}$, $1812.8{\sim}1926.5cm^{-1}$, $1623.8{\sim}1625.7cm^{-1}$ on adsorption and three bands were observed at $2140.6cm^{-1}$, $2073.1cm^{-1}$, $1969.0{\sim}2057.7cm^{-1}$ on vacumn desorption. The spectrum pattern observed for Ru/Ni-$SiO_{2}$ sample at 9/1 Ru/Ni mole content ratio on CO adsorption and on vacumn desorption is almost like the spectrum pattern observed for Ru-$SiO_{2}$ sample. But the spectrum patterns observed for Ru/Ni-$SiO_{2}$ samples under 8/2 Ru/Ni mole content ratio on CO adsorption and vacumn desorption are almost like the pattern observed for $Ni-SiO_{2}$ sample. It may be suggested surfaces of alloy clusters on the Ru/Ni-$SiO_{2}$ samples contain more Ni components than the mole content ratio of the sample considering the above phenomena. With Ru/Ni-$SiO_{2}$ samples the absorption band shifts may be ascribed to variations of surface concentration, strain variation due to atomic size difference, variation of bonding energy and electronic densities, and changes of surface geometries according to surface concentration variation. Studies for CO adsorption on Ru/Ni alloy cluster surface by LEED and Auger spectroscopy, interation between Ru/Ni alloy cluster and $SiO_{2}$, and MO calculation for the system would be needed to look into the phenomena.