Improvement of the electrochemical properties of V_3O_7ㆍH_2O nanobelts for Li battery application through synthesis of V_3O_7@C core-shell nanostructured composites

Yifu Zhang,Min Zhou,Meijuan Fan,Chi Huang,Chongxue Chen,Yuliang Cao,Houbin Li,Xinghai Liu 한국물리학회 2011 Current Applied Physics Vol.11 No.5

V_3O_7ㆍH_2O@C core-shell structured composites have been successfully synthesized using V_3O_7ㆍH_2O nanobelts as the cores and glucose as the source of carbon in the presence of sodium lauryl sulfate (SDS). The as-obtained V_3O_7ㆍH_2O@C core-shell materials were characterized by X-ray powder diffraction (XRD),transmission electron microscopy (TEM), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectrum. The thickness of the carbon shell can be controlled by the hydrothermal reaction time and the quantity of glucose. The surfactants have great influence on fabricating V_3O_7ㆍH_2O@C core-shell composites, which have been discussed in detail. V_3O_7@C composites were subsequently obtained through thermal treatment with V_3O_7ㆍH_2O@C. The electrochemical properties of V_3O_7@C core-shell composites were studied, indicating that the discharge capacity is still 151.2 mAh/g after 45 cycles, which is better than that of pure V_3O_7ㆍH_2O nanobelts.

Fabrication of heterostructured vanadium modified g-C3N4/TiO2 hybrid photocatalyst for improved photocatalytic performance under visible light exposure and antibacterial activities

Shanmugam Vignesh,Sanjeevamuthu Suganthi,Jeyaperumal Kalyana Sundar,Vairamuthu Raj 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.76 No.-

Improving visible-light active photocatalytic performance of the heterostructured g-C3N4-V-TiO2 (g-C3N4-Vanadium-TiO2) hybrid catalyst has been synthesized via facile calcination and ultrasonicdispersion facilitated hydrothermal techniques were considered. The phase composition, morphology,surface area, chemical structure as well as optical properties were systematically characterized. HR-TEMimages were exposed good crystallinity of g-C3N4-10% V-TiO2 nanocomposite (size~35–40 nm) with VTiO2porous discrete on g-C3N4 nanosheets. Too occurred in high pore volume and large surface area(91.5 m2 g 1) of g-C3N4-10% V-TiO2 hybrid catalyst compared than pristine g-C3N4. The 10% g-C3N4-V-TiO2photocatalyst shows substantial photocatalytic activity, 5.7 and 4.8 times higher that pristine g-C3N4nanosheets and TiO2 under visible light with the degradation efficiency over 99.5% for 60 min. Besides,the recycling test specified that the g-C3N4-10% V-TiO2 photocatalyst had admirable stability up to 5sequential cycles. The trapping assessments which authorize that OH radicals and h+ plays an activerole in the degradation process and the separation of photoinduced charges transversely theheterostructure boundary reserved electron-hole recombination they were good agree with PL studies. Moreover, g-C3N4-10% V-TiO2 composite catalyst show high catalytic antibacterial activity againstEscherichia coli (G ) and the Staphylococcus aureus (G+) bacteria.

LM3V 모델을 이용한 질소 순환 모의 및 적용성 평가

하림 ( Rim Ha ),박민지 ( Min-ji Park ),김경현 ( Kyung-hyun Kim ),이준우 ( Jun-woo Lee ),김성준 ( Seong-joon Kim ) 한국농공학회 2013 한국농공학회 학술대회초록집 Vol.2013 No.-

Interactions between the terrestrial carbon (C) and nitrogen (N) cycles shape the response of ecosystems to global change. The limitation of ecosystem C storage due to N availability, and the response of N₂O emissions to environmental conditions and N addition have been intensively studied. The global anthropogenic changes in C and N cycles call for modeling tools that are able to address and quantify essential interactions between N, C, and climate in terrestrial ecosystems. Recently, a growing number of global land surface models provide a means to scale ecological understanding of the nitrogen cycle to regional and global scales with the ultimate aim to investigate the magnitude of nitrogen cycling effects on global biogeochemistry, as well as their indirect consequences for biogeophysical land-atmosphere interactions. In this study, LM3V land surface model was applied within a prognostic N cycle for applicability in South Korea. LM3V was developed by the Princeton-Geophysical Fluid Dynamic Laboratory (GFDL). The model captures mechanisms essential for N cycling and their feedbacks on C cycling : N limitation of plant productivity, the N dependence of C decomposition and stabilization in soils, removal of available N by competing sinks, ecosystem losses that include dissolved organic and volatile N, and ecosystem inputs through biological N fixation. The model also captures many essential characteristics of C-N interactions and is capable of broadly recreating spatial and temporal variations in N and C dynamics. The introduced N dynamics improve the model's short-term NPP response to step changes in CO₂.

3GPP2 C.S0024-A v.2.0 표준을 적용한 CDMA2000 1x EV-DO 보안 계층 설계 및 구현

양종원(Jongwon Yang),조진만(Jinman Cho),이태훈(TaeHoon Lee),서창호(Changho Seo) 한국정보보호학회 2008 정보보호학회논문지 Vol.18 No.1

CDMA2000 1x EV-DO 에서의 보안 계층은 현재 3GPP2를 통해 표준화 규격(C.S0024-A v2.0)을 완성해 나가고 있는 중이다. 이에 따라 CDMA2000 1x EV-DO 환경의 AT(Access Terminal)와 AN(Access Network) 간 전송되는 데이터에 대한 보안 기능을 적용하기 위하여 표준 문서에 명시된 보안 계층 구현에 필요한 보안 장치가 요구되고 있다. 본 논문은 3GPP2의 C.S0024-A v2.0 표준을 준용한 CDMA2000 1x EV-DO 보안계층 설계 및 구현을 통해 AT와 AN간의 안전하고 빠른 데이터 전송 및 다양한 플랫폼 환경에 적용 가능한 보안계층 시스템을 실제 적용했다. In security layer in the CDMA2000 1x EV-DO, a standard - C.S0024-a v2.0 is being accomplished under the project of 3GPP2(3rd Generation Partnership Project2). Therefore, a security device is needed to implement the security layer which is defined on the standard document for data transfer security between AT(Access Terminal) and AN(Access Network) on CDMA2000 1x EV-DO environment. This paper realizes the security layer system that can make safe and fast transfer of data between AT and AN. It could be applied to various platform environments by designing and implementing the Security Layer in the CDMA2000 1x EV-DO Security Layer to which applies C.S0024-A v2.0 of 3GPP2.

하이브리드 V2X 통신시스템의 응용서비스 성능 평가를 위한 시나리오 설계 및 분석 연구

이성훈,이창교,변상봉,조수현,조현규 한국정보통신학회 2019 한국정보통신학회논문지 Vol.23 No.4

The convergence of the automotive industry and the ICT technology can be broadly divided into the commercial service sector and the Cooperative-ITS (C-ITS) service sector. The C-ITS service sector is using V2X communication technology as a field that aims to provide safer transportation, more green and efficient transportation, and more predictable and productive mobility. The recent convergence of self-driving cars and connected cars requires high data rates, low transmission delays, and low transmission error rates. Interest in comparison of performance between WAVE and C-V2X (LTE-V2X, 5G-V2X) has been amplified and application services by communication technology are being studied. In this paper, we design the application performance evaluation method of Hybrid V2X communication system and confirm that the decrease of packet error rate (PER) performance is caused by the increase of communication distance, not the vehicle speed. 자동차산업과 ICT 기술의 융합 분야는 크게 상용서비스 분야와 Cooperative–ITS (C-ITS) 서비스 분야로 나뉠 수 있다. C-ITS 서비스 분야는 더 안전한 운송, 더 친환경적이고 효율적인 교통, 및 더 예측가능하고 생산적인 이동성을 제공하는 것을 목표로 하는 분야로서 V2X 통신기술이 사용되고 있다. 최근 이슈가 되고 있는 자율주행자동차와 커넥티드 카의 융합을 위해서는 높은 데이터 전송율과 낮은 전송 지연, 그리고, 낮은 전송 오류율을 요구한다. 이를 위하여 최근의 WAVE와 C-V2X (LTE-V2X, 5G-V2X) 성능 비교에 관심이 증폭되고 있으며, 통신 기술별 응용서비스들이 연구되고 있다. 본 논문에서 하이브리드 V2X 통신시스템의 응용서비스 성능평가 방법에 대해 설계하였고, 패킷에러율(PER) 성능의 감소는 차량속도가 아닌 통신 거리의 증가에 의해 발생하는 것으로 보이는 결과 등을 확인하였다.

초기결과 3D C-SiC 복합재료의 마찰ㆍ마모특성에 관한 연구

김윤철(Yun Cheol Kim),김기정(Ki Jung Kim),장호(Ho Jang),박홍식(Hong Sik Park) 한국트라이볼로지학회 2005 한국트라이볼로지학회 학술대회 Vol.2005 No.11

The friction and wear properties between a 3D C-SiC composite disc and various materials were investigated. A pin on disc type friction tester was employed to assess friction characteristics of 3D C-SiC composite. The friction and wear tests of the 3D C-SiC disc were carried out in the range of extremely Jow speed using Al₂O₃, SiC and steel balls. A steel disc was also tested to compare with the case of the 3D C-SiC disc. The results showed that the friction force - v properties of Al₂O₃ and SiC balls were more stable than the steel ball in the case of the C-SiC disc. The friction properties of the steel disc showed negative friction force - v relations for all cases. In the wear tests, the steel ball .iad poor wear resistance for both discs. In particular, the wear amount of the C-SiC/steel contact was larger than the steel/steel contact. Al₂O₃, and SiC balls showed better wear resistance than the steel ball. Torque variation as a function of time shows different tendencies for various friction pairs.

SiO$_2$/Si$_3$N$_4$ 이중 박막의 C-V 특성

Hong, Nung-Pyo,Hong, Jin-Woong The Korean Institute of Electrical Engineers 2003 전기학회논문지C Vol.52 No.10

The double layers of $SiO_2$/$Si_3$$N_4$ have superior charge storage stability than a single layer of $SiO_2$. Many researchers are very interested in the charge storage mechanism of $SiO_2$/$Si_3$$N_4$ [1,2]. In this paper, the electrical characteristics of thermal oxide and atmospheric pressure chemical vapor deposition (APCVD) of $Si_4$$N_4$ have been investigated and explained using high frequency capacitance-voltage measurements. Additionally, this paper will describe capacitance-voltage characteristics for double layers of $SiO_2$/$Si_4$$N_4$ by "Athena", a semiconductor device simulation tool created by Silvaco, Inc.vaco, Inc.

고주파 마그네트론 스퍼터링에 의한 $SrTiO_3$ 캐패시터 박막의 온도 의존성

오금곤,이우선,김남오,김재민,이병성,김상용,Oh, Gum-Kon,Lee, Woo-Sun,Kim, Nam-Oh,Kim, Jai-Min,Lee, Byung-Sung,Kim, Sang-Yong 대한전기학회 1999 전기학회논문지C Vol.48 No.6

The $SrTiO_3$ thin films were prepared on Ag/TiN-coated and p-type bare Si(100) substrates by r.f. magnetron sputtering deposition technique. The electrical properties of the deposited films were investigated, which controlling deposition parameters such as substrate temperature and film thickness. The electrical properties ofthe $SrTiO_3$ films were measured using the capacitance-voltage(C-V) technique. The thickness dependence of the electrical properties of the $SrTiO_3$ films was analyzed of the connection with the films in series. The substrate affected the crystal structure and texture characteristics of the $SrTiO_3$ films. The resistivity of the film, sandwiched between Al and Ag films was measured, as a function of the temperature.

C-V2X 차량단말기 제품의 OmniAir 국제인증 평가방법에 대한 연구

Hyunsoon Lee,Kwangjoo Choi 한국ITS학회 2023 한국ITS학회 학술대회 Vol.2023 No.4

This text describes the evaluation method for Cellular Vehicle-to-Everything (C-V2X) On-Board Unit (OBU) products to obtain Omniair certification, an international certificiation organization. The evaluation method mainly includes physical layer tests, protocol tests, and actual vehicle driving tests for wireless communication. For this evaluation method, the test environment, test procedures, and test results are described for the Certification Operating Council (COC) test standard specified by Omniair.

Design, synthesis and ¹H NMR study of C_3v-symmetric anion receptors with urethane-NH as recognition group

Park, J.O.,Sahoo, S.K.,Choi, H.J. Pergamon 2016 Spectrochimica acta. Part A, Molecular and biomole Vol.153 No.-

<P>C-3v-Symmetric anion receptors 3 and 4 with urethane groups were synthesized by using trindane triol as tripodal molecular framework. In H-1 NMR titration study, the receptors showed noticeable downfield shift/disappearance of the urethane-NH peak in presence of H2PO4- and F- due to the host-guest complexation occurred through multiple hydrogen bonding and/or the deprotonation of urethane-NH groups. Other tested anions such as Cl-, Br-, HSO4-, and NO3- showed either no or negligible chemical shift of the urethane groups. The deprotonation event in 4 allowed selective detection of F- by perceptible color change from colorless to yellowish-red with the appearance of a new charge transfer absorption band at 450 nm. (C) 2015 Elsevier B.V. All rights reserved.</P>