• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.587-592
• /
• 2002

A new digital correlator fur an airborne synthetic aperture radiometer was designed in order to replace the conventional analog correlator unit which will become very complicated while the number of channels is increasing. The digital correlator uses digital IQ demodulator instead of the intermediate frequency (IF) phase shifter to make the correlation processing performed digitally at base band instead of analogly at IF. This technique has been applied to the digital receiver in softradio. The down-converted IF signals from each pair of receiver channels become low rate base-band digital signals after under-sampled, Digitally Down-Converted (DDC), decimated and filtered by FIR filters. The digital signals are further processed by two digital multipliers (complex correlation), the products are integrated by the integrators and finally the outputs from the integrators compose of the real part and the imaginary part of a sample of the visibility function. This design is tested by comparing the results from digital correlators and that from analog correlators. They are agreed with each other very well. Due to the fact that the digital correlators are realized with the help of Analog-Digital Converter (ADC) chips and the FPGA technology, the realized volume, mass, power consumption and complexity turned out to be greatly reduced compared with that of the analog correlators. Simulations show that the resolution of ADC has an influence on the synthesized antenna patterns, but this can be neglected if more than 2bit is used.

• Parasites, Hosts and Diseases
• /
• 제53권5호
• /
• pp.641-645
• /
• 2015

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

• 공업화학
• /
• 제9권5호
• /
• pp.624-628
• /
• 1998

초임계 이산화탄소내에서 방향족 유기용매(BTX)를 0.5% $Pt/{\gamma}-Al_2O_3$ 촉매가 충전된 고정층 반응기를 이용하여 완전분해를 시도하였다. BTX의 전환율은 반응기 입구에서 유기용매의 농도와 초임계 이산화타소의 몰밀도에 의존하는데, 입구농도가 감소함에 따라 전환율은 크게 증가되었고, 일정한 입구농도에서 온도 증가에 따라 반응은 잘 진행되어 전환율이 증가됨을 알 수 있었다. 동일 온도에서 압력이 증가함에 따라 큰 전환율을 보임을 알 수 있었다. 또한 실험조건 $300^{\circ}C$, 204.1 atm에서 benzene은 98.5% 이상의 전환율로 거의 완전산화 되었고, toluene과 xylene의 전환율은 $350^{\circ}C$, 204.1 atm의 조건에서 각각 82.0, 76.5%로 나타났다. 부분산화에 의한 중간생성물의 크로마토그램을 확인한 결과 중간생성물은 benzaldehyde, phenol, benzenemethanol 등으로 확인되었다. 충분한 산화반응 조건하에서 BTX가 중간생성물 없이 환경에 크게 영향을 미치지 않는 $CO_2$와 $H_2O$의 분해생성물로 분해가 가능한 것으로 판단되었다.

• 한국축산식품학회지
• /
• 제30권2호
• /
• pp.171-178
• /
• 2010

The objective of this study was to compare the quality characteristics of chicken breast and thigh meat from North Korean native chickens (NKNC), South Korean native chickens (SKNC, woorimotdak), and commercial broilers (CB). NKNC thigh meat had a higher crude protein content than CB. In addition, the breasts of NKNC and CB had higher pH values than that of SKNC, but the cooking loss was higher in NKNC. The surface color of the breast and thigh meat of NKNC was darker and redder than that of SKNC and CB. The total collagen content of the breast and thigh muscles was the highest in NKNC, followed by SKNC and CB. A similar trend occurred with breast meat hardness. The content of arachidonic and docosahexaenoic acids was higher in both the breast and thigh muscles of NKNC than in those of the other groups, while the concentrations of linoleic and linolenic acids were higher only in thigh meat. Sensory evaluation did not show any differences among the three different strains of chicken except for the meat color. Sensory panelists preferred thigh meat from SKNC and CB to that of NKNC due to the strong dark color of the NKNC. Based on these results, NKNC had harder breasts based on texture, as well as a darker surface color and higher composition of long chain polyunsaturated fatty acids than CB. The quality characteristics of SKNC tested in this study were intermediate between NKNC and CB; however, SKNC may have a better chance of acceptance by Korean consumers due to the undesirable color of NKNC.

• Geosciences Journal
• /
• 제22권6호
• /
• pp.975-987
• /
• 2018

Stable isotope ratios of $^{18}O/^{16}O$ and $^{13}C/^{12}C$ and rare earth elements geochemistry of the Upper Triassic carbonates from the Baluti Formation in Kurdistan Region of Northern Iraq were studied in two areas, Sararu and Sarki. The aim of the study is to quantify the possible diagenetic processes that postdated deposition and the paleoenvironment of the Baluti Formation. The replacement products of the skeletal grains by selective dissolution and neomorphism probably by meteoric water preserved the original marine isotopic signatures possibly due to the closed system. The petrographic study revealed the existence of foraminifers, echinoderms, gastropods, crinoids, nodosaria and ostracods as major framework constituents. The carbonates have micritic matrix with microsparite and sparry calcite filling the pores and voids. The range and average values for twelve carbonate rocks of ${\delta}^{18}O$ and ${\delta}^{13}C$ in Sararu section were -5.3‰ to -3.16‰ (-4.12‰) and -2.94‰ to -0.96‰ (-1.75‰), respectively; while the corresponding values for the Sarki section were -3.69‰ to -0.39‰ (-2.08‰) and -5.34‰ to -2.70‰ (-4.02‰), respectively. The bivariate plot of ${\delta}^{18}O$ and ${\delta}^{13}C$ suggests that most of these carbonates are warm-water skeletons and have meteoric cement. The average ${\Sigma}REE$ content and Eu-anomaly of the carbonates of Sararu sections were 44.26 ppm and 1.03, respectively, corresponding to 22.30 ppm and 0.93 for the Sarki section. The normalized patterns for the carbonate rocks exhibit: (1) non-seawater-like REE patterns, (2) positive Gd anomalies (average = 1.112 for Sararu and 1.114 for Sarki), (3) super chondritic Y/Ho ratio is 31.48 for Sararu and 31.73 for Sarki which are less than the value of seawater. The presence of sparry calcite cement, negative $^{13}C$ and $^{18}O$ isotope values, the positive Eu anomaly in the REE patterns (particularly for Sararu), eliminated Ce anomaly ($Ce/Ce^{\ast}$: 0.916-1.167, average = 0.994 and 0.950-1.010, average = 0.964, respectively), and Er/Nd values propose that these carbonates have undergone meteoric diagenesis. The REE patterns suggest that the terrigenous materials of the Baluti were derived from felsic to intermediate rocks.

• 자연과학논문집
• /
• 제1권
• /
• pp.47-59
• /
• 1987

티타닐 옥살산 바륨 사 수화물(BaTiO($$C_2$$O_4$)_2$ $4H_2$O) 의 분해반응을 열중량 분석법 (TG), 미분 열중량 분석법 (DTG) 그리고 시차 열분석법 (DTA) 를 이용하여 반응기구를 조사 하였다. 중간 생성물과 생성기체는 적외선 분광법과 X-ray회절법을 이용하여 확인하였다. 열분해 과정은 탈수 과정을 포함하여 5단계 분해과정으로 진행하였으며 1단계 분해과정은 탈수과정이며 일부 옥살산기의 분해과정이 함께 일어나게 된다. 2단계 분해과정에서는 1/2몰의 일산화 탄소가 방출되었다. 옥살산기의 분해는 $260~460^{\circ}C$의 온도범위에서 완전히 일어나고 분해하는 시료의 중간체에 자유로운 이산화 탄소기를 가지는 탄산화물을 생성하게 된다. 중간 생성체인 탄산화물의 최종분해는 $650~750^{\circ}C$에서 일어나며 티탄산 바륨 ($BaTiO_3$)이 생성된다.

• 한국축산식품학회지
• /
• 제39권1호
• /
• pp.139-150
• /
• 2019

This study aimed to determine the suitable point of sale and consumption of different quality grade (QG) Hanwoo short loin during aging period, based on physicochemical, sensory, and microbiological quality. Short loins obtained from the carcasses of 13 Hanwoo steers and 2 bulls with 5 different QGs (1++, 1+, 1, 2, and 3) were analyzed over 28 d. QG and aging time had significant effect on water holding capacity, color, shear force, total volatile basic nitrogen (TVBN) content, and sensory traits. Higher QG groups generally exhibited a lower shear force, nucleotide content, and water holding capacity, and higher $L^*$, $a^*$, and $b^*$ values. Acceptable tenderness (shear force <5.4 kg) in QG 1++, 1+, 1, and 2 was achieved on days 7, 14, 16, and 18, respectively, and QG 3 showed a shear force of 6.8 kg, even after 28 d. Regardless of QG, TVBN content below threshold levels (20-30 mg%) was observed throughout the 28 d aging period, while total plate counts above 7 Log CFU/g were seen at 21 d. In conclusion, it is recommended that Hanwoo beef with QG 1++, 1+, and intermediate QG (1 and 2) should be sold or consumed between 7 and 21, 14 and 21, 16 and 21 d, respectively. Beef with QG 3 should be sold or consumed within 21 d, based on microbial growth, even though it has not achieved desirable tenderness. For this reason, an additional tenderizing process is recommended before this beef is ready for consumption.

• Advances in Computational Design
• /
• 제4권2호
• /
• pp.119-139
• /
• 2019

Planning and management building projects should tackle the coordination of works and the management of limited spaces, traffic and supplies. Activities cannot be performed without the resources available and resources cannot be used beyond the capacity of workplaces. Otherwise, workspace congestion will negatively affect the flow of works. Better on-site management allows for substantial productivity improvements and cost savings. The procurement system should be able to manage a wider variety of materials and products of the required quality in order to have less stock, in less time, using less space, with less investment and avoiding multiple storage stations. The objective of this paper is to demonstrate the advantages of using the Chronographic modeling, by combining spatiotemporal technical scheduling with the 4D simulations, the Last Planner System and the Takt-time when modeling the construction of building projects. This paper work toward the aforementioned goal by examining the impact that material flow has on site occupancy. The proposed spatiotemporal model promotes efficient site use, defines optimal site-occupancy and workforce-rotation rates, minimizes intermediate stocks, and ensures a suitable procurement process. This paper study the material flow on the site and consider horizontal and vertical paths, traffic flows and appropriate means of transportation to ensure fluidity and safety. This paper contributes to the existing body of knowledge by linking execution and supply to the spatial and temporal aspects. The methodology compare the performance and procurement processes for the proposed Chronographic model with the Gantt-Precedence diagram. Two examples are presented to demonstrate the benefits of the proposed model and to validate the related concepts. This validation is designed to test the model's graphical ability to simulate construction and procurement.

• 한국가스학회지
• /
• 제25권6호
• /
• pp.29-34
• /
• 2021

제약회사에서 제조하는 의약품의 원재료에 인화성물질이 종종 존재한다. 이런 경우 과량의 인화성 물질을 투입하여 중간체를 만들고 반응에 참여하지 않은 인화성물질을 여과 및 건조단계를 통하여 제거하는 공정을 거치게 된다. 또한, 여과 공정에서 분리된 인화성 액체가 여액받이 통에 스플래쉬 필링 형태로 쌓이게 된다. 이런 경우 인화성 액체의 증기 및 미스트가 생성되어 폭발 하한 값, 최소점화에너지가 더욱 낮아지게 되며 복합 대전이 발생하여 화재·폭발의 위험이 증대된다. 본 연구에서는 최근의 제약회사 여과공정 중 발생한 화재 사고를 분석하여, 화재 폭발 사고를 방지하기 위한 방안으로 질소 공급설비 설치, 용량 개선, 도전성 여과포 및 정전기 축적 방지대책 등을 제시하고자 한다.

• Nuclear Engineering and Technology
• /
• 제53권7호
• /
• pp.2289-2294
• /
• 2021

In the present study, an original spark plasma sintering-reactive synthesis (SPS-RS) method for minerallike ceramic materials based on SrAl₂Si₂O₈ feldspar-like skeleton structure was used for the first time, promising solid-state matrices for reliable immobilization of high-energy ⁹⁰Sr. The method is based on the "in-situ" reaction of a mixture of SrO, Al₂O₃ and SiO₂ oxides when heated by a unipolar pulsed current under compacting pressure. The phase and elemental composition structure were studied. The dynamics of the consolidation of the reaction mixture of oxides was studied in the range of 900-1200 ℃. The study found the temperature of the high-speed (minutes) SPS-RS formation of single-phase SrAl₂Si₂O₈ composition ceramic in the absence of intermediate reaction products with a relative density of up to 99.2% and compressive strength up to 145 MPa and a strontium leaching rate of 10^-4g/cm²·day.