Herein, the edges in carbon materials were quantitatively evaluated by summing the amount of hydrogen and the amount of functional groups without hydrogen in the material. The amount of hydrogen in the carbon material was quantitated via temperature-programmed oxidation (TPO) under an oxygen atmosphere, whereas the amount of functional groups was determined via temperature-programmed desorption (TPD) of the sample under an inert atmosphere. Consequently, the amount of edges in exfoliated carbon fibers prepared from polyacrylonitrile (PAN) (referred to as PAN-1000) was 9.4 mmol g−1. In addition, Ketjen Black (KB) and activated carbon (AC) had edge content of 1.3 and 3.6 mmol g−1, respectively. Because the total amount of functional groups of PAN-1000, KB and AC were estimated to be 8.18, 0.082 and 1.02 mmol g−1 via TPD, the total amount of edges and oxygen-containing functional groups of each sample could be quantified. The difference between amount of edges and the amount of functional groups is speculated to correspond to the amount of edges terminated with hydrogen. This study revealed that detailed information about the edges such as their proportion terminated with oxygen-containing functional groups, the species and amount of oxygen-containing functional groups via a combination of TPO and TPD.

In this technology development, we have developed an automation system after developing a material rotation mixing process so that the manual process of sound absorbing materials can be supplied in quantities. After setting up 5kgf supply of the fused acoustic material, the setting value of 5kg was automatically supplied to the molded frame to reach the quantification supply. In the process of producing noise goods between floors, the automatic compression system was developed, which was a manual operation of three persons, and the production of one person was allowed, and the production of 200 sound absorbers per day, It has improved to 450. Quantitative supply unit was developed to reach 50.7mm for target 50±3mm based on the sound absorption product thickness indication, reducing the defect rate to less.

Most structures require high reliability to ensure safety and soundness. The materials used for these structures are not only defective in the manufacturing process and construction process, but also cause generation and progress of defects due to operation of various complex use environments. In order to improve the reliability of the structure, it is very important to detect and estimate the defect size. The method of evaluating these defects without damaging the structure is a non-destructive method. In this paper, an aluminum probe of AC potential drop(ACPD) method is applied to the evaluation of two-dimensional artificial defects in ferromagnetic materials. Since the potential drop of the defect end is larger than that of the sound area, the defect can be detected and its position can be clearly confirmed, and the potential drops are changed according to the depth of the defect. The potential drop ratio (Vjmax/Vs) of the defective area has a large value for the defect. The relationship between the potential drop ratio (Vjmax/Vs) of 10 kHz and the defect depth can reduce the error in predicting the depth.

Tungsten carbide (WC) hard materials are used in various industries and possess a superior hardness compared to other hard materials. They have particularly high melting points, high strength, and abrasion resistance. Accordingly, tungsten carbide hard materials are used for wear-resistant tools, cutting tools, machining tools, and other tooling materials. In this study, the WC-5wt.%Co, Fe, Ni hard materials are densified using the horizontal ball milled WC-Co, WC-Fe, and WC-Ni powders by a spark plasma sintering process. The WC-5Co, WC-5Fe, and WC-5Ni hard materials are almost completely densified with a relative density of up to 99.6% after simultaneous application of a pressure of 60 MPa and an electric current for about 15 min without any significant change in the grain size. The average grain size of WC-5Co, WC-5Fe, and WC-5Ni that was produced through SPS was about 0.421, 0.779, and 0.429 μm, respectively. The hardness and fracture toughness of the dense WC-5Co, WC-5Fe, WC-5Ni hard materials were also investigated.

식품 제조업체에서 식품 내에서 발생하는 곤충관련이물의 저감화를 위하여 과자류, 면류, 캔디류에서의 곤충관련이 물 클레임 발생 상황을 2010년부터 2018년까지 약 9년간 1481건의 곤충관련이물 클레임을 현물, 사진 등을 통하여 조사하였다. 과자류에서는 분류학적으로는 딱정벌레목, 생태학적으로는 저장해충류가 높은 빈도를 보였으며, 발생유 형으로는 치사성충의 빈도가 가장 높게 나타났다. 또한, 면류, 캔디류에서는 분류학적으로는 나비목, 생태학적으로는 저장해충류가 가장 높은 빈도를 차지하였으며, 발생유형으로는 치사성충의 빈도가 가장 높게 나타났다. 모든 식품유형 에서 공통적으로 곤충이물은 유통, 소비 단계에서 주로 유입되는 것으로 조사되었다.

2017년부터 2018년까지 전북지역 오디 생산용 뽕나무에 발생하는 주요 해충의 발생 양상과 유기농업자재에 의한 뽕나무이 방제 효과를 조사하였다. 부안과 익산지역을 중심으로 수확 전 발생하는 주요 해충은 뽕나무이, 미국흰불나방, 뽕나무명나방, 노린재류, 꽃매미 6종이었으며 수확 후에는 미국흰불나방, 뽕나무명나방, 총채벌레, 미국선녀벌레, 노린재류 등 5종이 발생하였다. 또한 오디 생산용 뽕나무 재배시 가장 문제가 되는 병해충인 균핵병과 뽕나무이를 동시에 친환경적으로 관리하기 위해서는 데리스 추출물(데리스 90%) 250배와 황토유황 500배를 혼합하여 처리하는 것이 방제효과 97.6%로 효과적이었다. 선발된 유기농업자재에 효과적인 처리시기는 4월 상·중순이며, 7일 간격으로 3회 방제하면 94% 이상의 방제효과가 있고 약해도 발생하지 않아 유기농업자재를 이용한 뽕나무이의 친환경방제가 가능할 것으로 판단되었다.

As concerns about the pursuit of well-being culture and interest in safe food has increased and demand for organic agricultural products are increasing. This study was conducted to investigate the occurrence pattern of diseases and pests and to select effective organic materials for control of diseases and pests in organic watermelon. The watermelon was damaged by diseases and pests such as Didymella bryoniae, Podosphaera xanthii, Aphis gossypii, Tetranychus urticae, thrips, Spodoptera exigua, and Spodoptera litura. Among them, powdery mildew and cotton aphid are major disease and pest in organic watermelon. The occurrence of powdery mildew and cotton aphid initiated in the middle of May in Chungju and Eumseong. The control efficacy for eleven organic materials against powdery mildew was evaluated. As the results, the symptoms of plant disease were effectively reduced by more than 85% in the treatments of materials such as sodium bicarbonate 80% and sulfur 80%. The treatment of TFM-6 (insect repellent 2%+paraffin oil 68%) and TFM-7(cinnamomum ext. 10%+derris ext. 20% + citranella oil 30%) showed by more than 80% in control efficiency against cotton aphid. Tstudy was supported by the research project of RDA.(Project No.: PJ0125302018)

목적 : 재질이 다른 두 종류의 한달 착용 실리콘하이드로겔 렌즈를 착용 기간에 따라 렌즈 전면의 NITBUT와 자각적 증상을 비교하였다. 방법 : Samfilcon A와 Comfilcon A 렌즈를 32명(평균 23.5±2.92세, 여: 24명, 남: 8명)의 오른쪽 눈과 왼쪽 눈에 각각 착용하고, 대상자에게 3회 방문 (첫째 날 3시간 후, 1일 및 1주일 렌즈 착용 9시간 후)을 요청한 후, 고대비도(100%)와 저대비도(10%) 시력표를 이용한 시력검사와 Keratograph 5M (Oculus, Germany)을 사용하 여 렌즈 전면의 non-invasive tear breakup time (NITBUT)를 측정하였다. 콘택트렌즈와 관련 있는 자각적 증상은 5개 항목(불편함, 건조감, 시력 변화, 눈 감고 싶음, 렌즈 제거하고 싶음)으로 설문지 작성을 하도록 하였다. 결과 : 밝은 조명상태에서 검사한 고대비시력과 저대비시력, 그리고 렌즈 전면의 NITBUT는 Samfilcon A와 Comfilcon A 사이에서 유의한 차이가 나타나지 않았고, 각각의 렌즈 착용 7일 동안 시력과 NITBUT 변화에서도 의미 있는 차이는 없었다. 콘택트렌즈 착용과 관련된 5개 항목의 자각적 증상의 상대적 발생빈도는 모든 항목에서 유의한 차 이가 없었고, 렌즈에 대한 선호도에서도 두 렌즈 착용자들의 반응은 통계적으로 차이가 없었다(각각, 40.6%, 37.5%). 결론 : 이 연구는 Samfilcon A와 Comfilcon A사이에서 pre-lens NITBUT와 자각적 증상에 대한 비슷한 임상 결과를 보여준다. 두 실리콘하이드로겔 렌즈는 제조사와 렌즈 재질이 다름에도 불구하고 렌즈 착용자들 사이에 서 두 렌즈의 차이점은 발견할 수 없었다.

In this study, the physical and sensorial properties of the meat analog were studied for the purpose of improving sensory preference and mimicking animal meat. The meat analog was made with different types of liquid materials such as oil, water, lecithin, polysorbate 80, or the emulsion of these components. At the aspect of density, the sample mixed with oil was higher than the sample mixed with water. Cooking loss value was higher at the sample with water than the sample with oil and this was the result opposite to the liquid holding capacity analysis. Also, texture profile analysis result showed that the samples with medium chain triglycerides (MCT) oil only showed the highest values in all attributes except for adhesiveness. Principal component analysis was carried out to analyze sensorial properties and it showed that the overall acceptance was high when the juiciness and softness increased. This result was highly related with the addition of emulsion. Therefore, emulsion technology can be a good candidate for improving the quality of meat analog and for mimicking the taste of animal meat.

High performance lithium-ion batteries (LIBs) have attracted considerable attention as essential energy sources for high-technology electrical devices such as electrical vehicles, unmanned drones, uninterruptible power supply, and artificial intelligence robots because of their high energy density (150-250 Wh/kg), long lifetime (> 500 cycles), low toxicity, and low memory effects. Of the high-performance LIB components, cathode materials have a significant effect on the capacity, lifetime, energy density, power density, and operating conditions of high-performance LIBs. This is because cathode materials have limitations with respect to a lower specific capacity and cycling stability as compared to anode materials. In addition, cathode materials present difficulties when used with LIBs in electric vehicles because of their poor rate performance. Therefore, this study summarizes the structural and electrochemical properties of cathode materials for LIBs used in electric vehicles. In addition, we consider unique strategies to improve their structural and electrochemical properties.

본 연구는 광화문 월대로 사용된 석재를 대상으로 암석학적 연구를 활용한 석재공급지를 추정하기 위해 수행되었다. 월대는 2010년에 일부 구간이 다시 복원된 것으로 원부재인 담홍색 화강암과 신석재인 회백색 화강암이 사용되었다. 석재공급지 추정을 위해 북한산과 수락산의 지질조사를 수행하였으며 채취한 시료는 모두 담홍색 화강암과 유사한 특징을 보였다. 전암대자율은 북한산에 비해 수락산의 값이 크고 암석의 색에서 부분적인 차이를 보이지만 수락산이 상대적으로 선명한 담홍색을 띤다. 수락산은 월대에 사용된 원부재와 비슷한 암석기재적 특징, 전암대자율, 역사적 사료 그리고 야외조사 시 발견된 채석흔적 등을 통해 최종 복원용 석재공급지로 판단된다. 물성시험 결과, 월대 원부재는 풍 화로 인해 147 MPa로 다소 낮은 수치를 보이며 석재공급지로 생각되는 수락산은 244 MPa 높은 값을 보여 안정성까지 확보되어 양질의 석재로 사용 가능하다. 수락산 일대는 주거지역이 일부 포함 되어 있어 행정적인 문제, 자연파괴, 인근 주민 생활권 침해가 발생하여 채석활동은 어렵다. 또 다른 대안으로 QAP조성, 광물조직, 암색 등의 암석학적특징 및 물리적 특성까지 유사한 중-조립질 담홍색화강암의 포천 창수석과 영중석을 제안할 수 있다.

The algal blooms in stagnant streams and lakes have caused many problems. Excessive algae leads to disturbance of ecosystem and overload of water treatment processes. Therefore, phosphorus(P), source of algal blooms, should be controlled. In this study, a filtration trench has been developed to convert dissolved phosphorus into hydroxyapatite(HAP) so that it could be crystallized on the surface of ‘phosphorus removal granular material’; and residual particulate phosphorus could be removed by additional precipitation and filtration. The front and rear parts of filtration trench consisted of ‘phosphorus removal granular material contact bed’ and ‘limestone filtration bed’, respectively. As a result of the column test using phosphorus removal granular material and limestone serially, PO4-P was removed more than 90% when EBCT(empty bed contact time) of the contact bed was over 20 minutes; and T-P represented 60% of removal efficiency when total EBCT was over 1.5 hours. The results of column tests to figure out the sedimentation characteristics showed that more than 90% of particulate phosphorus could be removed within 24 hours. It was necessary to optimize the filtration part in order to increase removal efficiency of T-P additionally. Also, it was confirmed through the simulation of Visual MINTEQ that most of particulate phosphorus in the column tests is the form of HAP. Based on the results of the study, it could be suggested that the design parameters are over 0.5 hour of EBCT for phosphorus removal granular material contact bed and over 1.5 hours of EBCT for limestone filtration bed.

In this study, a multifunctional ophthalmic lens material with an electromagnetic shielding effect, high oxygen permeability, and high water content is tested, and its applicability is evaluated. Metal oxide nanoparticles are applied to the ophthalmic lens material for vision correction to shield harmful electromagnetic waves; the pyridine group is used to improve the antibacterial effect; and silicone substituted with urethane and acrylate is employed to increase the oxygen permeability and water content. In addition, multifunctional tinted ophthalmic lens materials are studied using lens materials with an excellent antibacterial effect (2,6-difluoropyridine, 2-fluoro-4-pyridinecarboxylic acid) and functional (UV protection, high wettability) lens materials (2,4-dihydroxy benzophenone, 2-hydroxy-4-(methacryloyloxy)benzophenone). To solve problems such as air bubbles generated during the polymerization process for the manufacturing and turbidity of the lens surface, polymerization conditions in which the defect rate is minimized are determined. The results show that the polymerization temperature and time are most appropriate when they are 110 oC and 40 minutes, respectively. The optimum injection amount of the polymerization solution is 350 ms. The turbid phenomenon that appears in lens processing is improved by 10 to 95% according to the test time and conditions.

The purpose of this study is to enhance heat insulation effect and to decrease fire hazard by attaching aluminum foil to expanded polystyrene, which is mainly used for insulating materials, to have fire retardant. The result of the test confirmed that the insulating materials, expanded polystyrene of 10 kg/m3 and 14 kg/m3 of density attached aluminum foil on both sides, showed 12%, 14% of improved heat transfer coefficient respectively compared to existing expanded polystyrene of the same density. Besides, they met all the standards for the testing of heat release and gas hazard. On the other hand, the one made of general expanded polystyrene could not meet the standards of the heat release test and the gas hazard test.

Graphene is a single atomic layer of carbon atoms, and has exceptional electrical, mechanical, and optical characteristics. It has been broadly utilized in the fields of material science, physics, chemistry, device fabrication, information, and biology. In this review paper, we briefly investigate the ideas, structure, characteristics, and fabrication techniques for graphene applications in lithium ion batteries (LIBs). In LIBs, a constant three-dimensional (3D) conductive system can adequately enhance the transportation of electrons and ions of the electrode material. The use of 3D graphene and graphene-expansion electrode materials can significantly upgrade LIBs characteristics to give higher electric conductivity, greater capacity, and good stability. This review demonstrates several recent advances in graphenecontaining LIB electrode materials, and addresses probable trends into the future.