Liquid phase exfoliation of natural graphite is an industrially effective solution for graphene preparation. However, many countries have identified natural graphite as a strategic resource and restricted its mining. In this report, we used abundant and readily available needle coke (NC) as a graphene exfoliation precursor and sodium carboxymethyl cellulose (CMC) as a dispersant to prepare a sandwich structured conductive graphitized NC nanosheets (GNCNs) by liquid phase exfoliation, freeze-drying and high-temperature graphitization, in which a graphene layer is sandwiched between two thin CMC layers. CMC could increase the liquid absorption and retention ability of the conductive agent and improve the migration rate of lithium ions. The highly ordered graphene layer could accelerate the transmission of electrons. The GNCNs with 0.4 wt% CMC addition showed good rate performance (144.6 mAh g− 1 at 5 C) and high cycle stability (96.2% after 200 cycles at 1 C) for LiFePO4 (LFP) battery. The traditional Super-P (SP) conductive agent exhibited low-rate performance (113.9 mAh g− 1 at 5 C) and cycle performance (89.9% after 200 cycles at 1 C). This study offers a novel approach to selecting graphene precursors and has promising applications for conductive additives in high-performance LFP batteries.
2008년 미국에서 시작된 글로벌 금융위기로부터 시작된 자유주의 질 서 위기는 미국 패권 쇠퇴의 서막을 알렸고, 2010년 유로존 위기, 그리 고 Covid-19 대유행은 이를 서방 전체의 위기 심화로 만들었다. 따라서 중국의 부상은 미국 패권질서에 균열을 내며 ‘신냉전’ 국제질서를 형성시 키고, 러시아의 우크라이나 공습으로 이어지며 이는 실질화 되고 있다. 무엇보다 EU의 취약점인 군사안보 분야에 대한 강한 도전이라는 점에서 ‘서방’의 위기감은 공유되고 있다. 본 연구는 이러한 대외적 변화와 이에 대응하기 위한 EU의 안보정책과 그 전망에 대해서 살펴보았다. 그동안 경제적 우위에 기댄 대안 규범(시민)권력을 안보적 층위에서 고려해 온 EU의 군사안보가 정부간주의로 보완해 왔으나, 영국의 이탈과 NATO의 방치로 군사안보 공백을 어떻게 유인해 낼 것인가 하는 점은 향후 국제 질서를 가늠한데 요소라는 점에서 중요하다. 특히, EU가 NATO를 매개 로 인도태평양, 동아시아로 이어지는 군사적 횡단 연합 전선에서 어떤 역할을 맡게 될 것인지 하는 지점은 주요하게 살펴봐야 할 부분이다.
최근 신체활동에 대해 인식하는 센서와 그 제품군에 대한 관심 및 수요가 증가하고 있다. 특히 유연하고 연신이 가능하 며 사용자의 생체신호를 감지할 수 있는 웨어러블 소재에 대한 개발이 주목받고 있다. 본 연구에서는 소수성 소재에 Micro Needle을 통해 미세 구멍을 형성한 후 SWCNT 분산용액에 대한 함침 효율을 향상시키는 실험을 수행하였다. 본 연구에서 는 구멍을 뚫지 않은 소재를 대조(control) 군으로 함침을 진행, 비교 분석하였다. 센서의 전기전도도를 평가하기 위해 Strain UTM (Universal Testing Machine, UTM, Dacell)과 저항을 측정하는 멀티미터(Keysight)를 이용해 센서를 인장했 을 때의 센서의 전기전도도를 측정하였다. 또한 센서의 내구성을 평가하기 위해 시료별로 500회 인장을 진행한 후에 센서 의 전기전도도를 평가하였다. 그 결과 Needling을 한 센서의 전기전도성이 Needling을 하지 않은 센서에 비해 최소 16배 이상 뛰어남을 알 수 있었다. 또한 센서의 초기 저항에 비해 게이지 팩터도 우수해 센서로서 좋은 성능을 확인할 수 있었다. 이를 통해 친수성 소재에 비해 물성이 뛰어나지만, 높은 표면장력 때문에 함침 효율이 좋지 않았던 소수성 소재의 함침 효율을 높여 신체의 움직임을 더 효과적으로 감지하고 내구성과 활용 가능성이 뛰어난 센서를 제작했다.
Based on many previous studies, this study reviewed the effects of needle-free intradermal injection (NFI) on the prevention of the incidence of lesions at the injection site in pork from pigs vaccinated with the foot-and-mouth disease vaccine, the reduction of the vaccine dose, the stress-relief of vaccination, and the reduction of farm worker-related injuries. The vaccine and drugs injected with the NFI pass through the tissue and are widely dispersed along the path of least resistance, resulting in a vastly dispersed, spider-web-like distribution of the medication and absorbed quickly. In addition, since NFI is inoculated into the dermal layer where immune cells are abundantly distributed, even a small amount of vaccination shows an antibody-forming effect similar to that of the conventional needle intramuscular injection. NFI is a method suitable for animal welfare because the vaccine or drug is widely dispersed over the inoculation site and causes less pain or stress than the needle intramuscular injection. Use of NFI system for the vaccination and drug delivery improves work efficiency in farms and reduces the incidence of musculoskeletal disorders in farm workers. In the future, it is judged that in-depth studies are needed on the effect of improving productivity and reducing the dose of antibiotics through NFI.
This study compared the immune responses, stress relief and weight gains of needle or needle-free intramuscular and needle-free intradermal vaccination in pigs. When the same amount of a foot-and-mouth disease (FMD) vaccine was administered to pigs, antibody titers at 4 weeks after the 1st and 2nd FMD vaccination were not significantly different between the needle (IM-S) and needle-free (NM-P250) intramuscularly vaccinated groups, but the weight gain of NM-P250 was significantly increased compared to that of IM-S at 8 weeks after the 2nd FMD vaccination (p<0.05). In addition, serum cortisol concentrations of NM-P250 were considerably decreased compared to those of IM-S on the 5th and 7th day after the 1st and 2nd FMD vaccination (p<0.05). However, the antibody titers of IM-S vaccinated with 2 mL of FMD vaccine were significantly increased compared to those of the needle-free intradermal vaccinated group with 0.5 mL of FMD vaccine at 4 weeks after the 1st and 2nd FMD vaccination (p<0.05). In conclusion, the needle-free intramuscular injection for the FMD vaccination can be chosen for weight gain and stress relief in pigs.
This study tried to develop Jinmal dasik using pine nuts leaf powder with antibacterial and antioxidant properties. After preparing the Jinmal dasik in proportions of 0%, 2%, 4%, 6%, and 8% by varying the ratio of pine needle powder, the moisture, color, physical properties, antioxidant properties and sensory quality were measured. Except for the 8% Jinmal dasik, the L value of chromaticity significantly decreased as the amount of pine needle powder increased (p<0.001). In addition, the value significantly decreased with increased density (p<0.001). Based on our physical properties evaluation results, the hardness, cohesiveness, and elasticity decreased significantly as the amount of pine needle powder increased (p<0.001), but adhesion and chewiness increased significantly with an increase in the amount of pine needle powder (p<0.001). Total polyphenol content was significantly increased except for the 8% Jinmal dasik (p<0.001). DPPH and ABTS also increased significantly as the amount of pine needle powder increased (p<0.001). Our sensory evaluation, showed the 2% Jinmal dasik to have the highest degree of preference, however, there was no significant difference among the proportion groups (p=0.053).
초음파 내시경 검사는 내시경 선단에 달린 초음파 탐지자를 이용하여 위장관 내에서 초음파를 이용하여 주변 장기를 관찰하는 검사다. 초음파 내시경을 이용하면 췌장을 고해상도로 실시간 관찰하면서 병소에 대한 조직 검사가 가능하다. 초음파 내시경 유도하 조직 검사는 지난 20여 년간 초음파 내시경 및 세침의 발전과 해부학적 구조의 이해 및 내시경을 통한 조직 검사 술기 등의 발전으로 췌장 질환에 대한 기본적인 비수술적 조직 검사가 되었다. 본고에서는 최근에 발표된 유럽 및 국내 가이드라인에서 언급하고 있는 내시경 초음파 유도하 조직 검사의 췌장 병변에서의 활용 기준과 다양한 종류의 조직 세침의 특성에 따른 선택, rapid on site evaluation, stylet 및 음압의 사용, fanning technique 등 검사에서 고려할 사항 및 조직 검체 처리 방법, 합병증 및 교육에 대해서 간략히 기술하였다.
Although fine-needle aspiration biopsy (FNAB) has been widely accepted as a valuable tool for differential diagnosis of head and neck tumors, the diagnostic value of FNAB in the management of salivary gland tumors has been questioned. This case report presents a patient with mucoepidermoid carcinoma of parotid gland diagnosed as pleomorphic adenoma by FNAB and discusses the pitfalls in the diagnosis of malignant salivary gland tumors.
The XYZ 3-dimensional thermal conductivities of the C/C up to 2000 °C were measured by a laser flash method. Carbon fiberreinforced carbon composites (C/C) were generally developed for aerospace missions due to their excellent thermal resistivity at ultrahigh temperature. C/C must endure harsh environments such as thousands of degrees Celsius without degradation of its mechanical properties. To solve this problem, among the passive thermal protection system, we suggest a method of conducting more heat through the mono-axial direction, which resulted in ease of the thermal rise in the heat receiving part. For example, the X-43A flight applied unbalanced C/C (UCC) with different carbon fiber orientation ratios according to the XY direction in the leading edge part. To investigate the difference in thermal conductivity between unbalanced C/C (UCC) and balanced C/C (BCC), unbalanced and balanced preforms were prepared by a needle punching process, and then they were densified by pitch infiltration and a carbonization process. We compared and analyzed the effects of unbalanced C/C(UCC) and balanced C/C (BCC) structures on the thermal conductivity. We also designed the “rule of mixtures” equation for calculating thermal conductivities of each C/C using reported data of carbon fiber and graphite matrix. Our calculations of thermal conductivity ratio match the ratio of real data.
Wire arc additive manufacturing (WAAM) is being considered as a technology to replace the conventional manufacturing process of titanium alloys. However, coarse β grains, which can extend through several deposited materials, result in strong textures and anisotropy. As a solution, we study the plastic deformation effects of ultrasonic needle peening (UNP) on the microstructure. UNP treated materials deform plastically and the dislocation density increases. Fine α+α' grains with low aspect ratio are observed in the UNP treated specimens. UNP treated WAAM Ti-6Al-4V alloys have higher strength and lower elongation than those characteristics of WAAM Ti-6Al-4V alloys. Due to UNP treatment, the z-axis directional specimens exhibit a greater effect of reducing elongation than do the x-axis directional specimens. The UNP treatment produces fine grains in proportion to the number of times UNP is performed, thereby increasing strength. UNP processes produce a large number of dislocations in the WAAM Ti-6Al-4V alloys, with the most dislocations being formed at the surface.
The porous carbons with high specific surface area and excellent electrochemical properties were prepared using three types of green needle coke as raw materials. Electrochemical performances of the porous carbons derived from different microstructure green needle coke were investigated. The XRD and Raman spectra demonstrated that the content of the ordered carbon microcrystals were decreased and the content of amorphous and cross-linked structure were increased in the porous carbons with comparison to the raw materials. The results of N2 adsorption–desorption analysis verified that the content of ordered microcrystalline structure in the raw materials evidently influence the specific surface area and pore size distribution of the porous carbons. The porous carbon with 1665 m2 g−1 specific surface area and 2.89 nm average pore size has shown that the specific capacitance was 288 F g−1 at the current density 1 A g−1. Furthermore, the capacity retention was 94.93% and the Coulombic efficiency was 92.87% after 5000 charge/discharge cycles.
본 논문에서는 Needle-punched C/SiC 복합재료 해석을 위한 효율적인 멀티스케일 해석기법을 소개한다. 기존 Needle-punching으 로 인해 복잡한 미소구조를 갖는 NP 복합재료는 기존의 제안된 복합재료 멀티스케일 기법으로 물성을 계산하는 것은 한계가 있어 왔다. 이를 극복하기 위해 micro-CT 이미지 촬영을 통해 NP 복합재료의 미소구조를 면밀히 파악할 수 있었고, 이미지 프로세싱을 바탕으로 실제구조와 직접적으로 대응할 수 있는 3D high fidelity 모델을 구축하였다. 또한 유한요소해석에 맞춰 요소크기를 조절할 수 있는 sub-region processing 소개를 바탕으로 효율적인 유한요소해석을 수행하였다. NP 복합재료의 미소구조 거동뿐만 아니라, macro-scale 구조해석의 적용을 위해 subcell 모델링을 제안하였다. Needle-punching에 의한 Z축 NP 섬유의 규칙적인 간격을 이용하여 모델링을 수행할 수 있었다. 제안한 두 종류의 모델은 균질화 기법을 이용하여 등가거동 및 등가물성을 파악하였으며, 추가적인 실험 결과와의 비교를 통해 검증을 수행하였다.
In recent years, interest in halal authentication from the domestic food and cosmetics field has been growing for advances into the overseas halal market. For halal authentication, the product must not contain haram ingredients derived from pig, dog, human, GMO, etc. In this study, the presence of haram ingredients in plant extracts (carrot, oyster mushroom, and pine needle) treated with papain and bromelain and cosmetics (mask pack and cream) containing these extracts were analyzed by PCR to confirm whether these cosmetics were suitable for halal authentication. Detection limits of the PCR method that specifically detected template DNA of human, pig, dog, and GMO were 1.29×103, 1.14×103, 1.24×102 and 2.02×103 copies/tube, respectively. PCR was not inhibited by the plant extracts or cosmetic ingredients. Results of PCR for the plant extracts or cosmetics containing these extracts were all negative. This PCR method could be used to rapidly identify the presence of haram ingredients in raw materials or final products during the manufacturing process of food and cosmetics.
내시경 초음파 유도 가는 바늘 생검은 췌담도 질환의 진단 영역에서 잘 알려진 안전한 시술이다. 심각한 천공, 췌장염, 출혈, 감염의 합병증은 드물게 보고되고 있다. 시술 후에 발생한 지연성 출혈의 보고는 매우 드물고, 시술 후 가성 동맥류으로 인한 지연성 출혈의 보고는 저자가 알기로는 없는 것으로 알고 있다. 저자는 췌장의 고형성 병변에 대한 내시경 초음파 가는 바늘 생검 후에 발생한 위십이지장 동맥 가성 동맥류로 인한 지연성 출혈을 보고한다. 68세 남자 환자가 췌장두부에 15 mm 가량의 종양으로 시술 10일 후에 흑색변을 주소로 재방문 하였다. 당시 복부 전산화단층촬영을 시행하였고, 2 cm 가량의 조영증강의 둥근 병변이 췌장의 두부에서 확인되었고, 조직 검사 결과는 악성을 시사하지 않았다. 환자에게 추가 검사를 위하여 입원을 권유하였으나 거부하였다. 12일 후에 환자는 반복되는 흑색변을 주소로 응급실에 재방문하였다. 혈관조 영술에서 위십이지장동맥 가성동맥류 소견 및 코일 색전술을 시행한 후 성공적으로 지혈하였다. 환자는 유문 보존 췌십이지장 절제술을 받았고, 병기는 IIB 췌장암으로 진단되었다.
Needle-like NiO protecting layers on NiCrAl alloy foam, used as support for hydrogen production, are introduced through electroplated Ni and subsequent microwave annealing. To improve the stability of the NiCrAl alloy foam, oxygen concentration of microwave annealing to form a needle-like NiO layer with good chemical stability and corrosion resistance is controlled in a range of 20 and 50 %. As the oxygen concentration increases to 50 %, needle-like NiO forms a dense coating layer on the NiCrAl alloy foam; this layer formation can be attributed to accelerated growth of the (200) plane. In addition, the increased oxygen concentration causes increased NiO/Ni ratio of the resultant coating layer on NiCrAl alloy foam due to improved rate of the oxidation reaction. As a result, the introduction of dense needle-like NiO layers formed at 50 % oxygen concentration improves the chemical stability of the NiCrAl alloy foam by protecting the direct electrochemical reaction between the electrolyte and the foam. Thus, needle-like NiO can be proposed as a superb protecting layer to improve the chemical stability of NiCrAl alloy form.
Physical and electrochemical qualities were analyzed after KOH activation of a direct methanol fuel cell using needle coke as anode supporter. The results of research on support loaded with platinum-ruthenium suggest that an activated KOH needle coke container has the lowest onset potential and the highest degree of catalyst activity among all commercial catalysts. Through an analysis of the CO stripping voltammetry, we found that KOH activated catalysis showed a 21% higher electrochemical active surface area (ECSA), with a value of 31.37 m2/g, than the ECSA of deactivated catalyst (25.82 m2/g). The latter figure was 15% higher than the value of one specific commercial catalyst (TEC86E86).
c-Fos is known to related to synaptic plasticity and apoptosis in damage from ischemia or external injury. The purpose of this study was to investigate whether needle electrode electrical stimulation(NEES) is effective in increasing the number of c-Fos response cells and c-Fos expression in striatum after global ischemia in rats. There were no treatment and occlusion in the control group, global ischemia(GI) group were no treatment after carotid artery occlusion, and needle electrode electrical stimulation(NEES) group were treated with NEES after GI induced. The number of striatum c-Fos response cells and c-Fos protein expression significantly decreased in the NEES group compared to the GI group after 12, 24, 48 hours. The results of the present study suggest that NEES is ineffective in improving global ischemia in rats and may also be ineffective in the globally ischemic human brain.