• Title/Summary/Keyword: gNB

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Rheological properties of arabinogalactan solutions isolated from the legumes (콩류 아라비노갈락탄 용액의 유변학적 성질)

  • Kim, Kyeong Yee;Kim, Choon Young
    • Korean Journal of Food Science and Technology
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    • v.51 no.4
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    • pp.330-335
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    • 2019
  • The aim of this study was to investigate the rheological properties of arabinogalactans (AGs) solution isolated from moth bean (MB), navy bean (NB), and soybean (SB) including monosaccharide compositions, intrinsic viscosity, steady shear and dynamic shear rheological properties. The major monosaccharides in MB, NB, and SB were arabinose (64.8, 51.4, and 42.6%) and galactose (13.4, 19.6, and 46.2%). The yield stresses for 5% (w/v) NB and 2.5% (w/v) SB solutions were assessed as 2.10 Pa and 1.98 Pa, respectively, but in case of MB solution, it was observed to be negligible. While 5% MB solution showed rheopectic property, 5% NB and SB solutions showed thixotropic properties. As a result of frequency sweep experiment, the G' values in 2.5% MB and NB were larger than the G" value showed but 2.5% SB exhibited G" value greater than G'. These results would be useful for future application as a food additive in the food industry.

A Cellular Broadcast Service Based on NB-IoT (NB-IoT 기반의 재난문자 서비스)

  • Byun, Yoon-Kwan;Chang, Sekchin
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2020.07a
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    • pp.481-482
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    • 2020
  • 다양한 재난경보 전달 매체 중 재난문자 서비스는 재난 발생 시 재난 지역과 관련된 대국민 대상으로 재난경보를 빠르고 신뢰성 있게 전송할 수 있는 보편 매체이다. 현재 국내 재난문자 서비스는 2G/4G 셀룰러 환경에서 셀룰러 이동 단말기에 재난문자를 전송한다. 특히 4G 이상의 셀룰러 시스템은 재난문자 전송을 위하여 SIB를 이용한다. 그러나 현 재난문자 서비스는 셀룰러 이동 단말기만 수신이 가능한 한계를 보인다. 재난경보 수신의 성공률을 높이기 위하여 다양한 수신 단말기의 재난문자 서비스 지원이 필수적이다. 현재 NB-IoT는 4G 셀룰러 환경을 기반으로 광범위한 지역에 저전력 서비스를 제공한다. 본 논문에서는 NB-IoT가 재난문자 수신을 위하여 필요한 프로토콜 규격과 NB-IoT 기반의 재난문자 서비스를 위한 네트워크 구조를 제시한다.

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Production of Conjugated Linoleic Acid by Lactobacillus acidophilus Isolated from Breast-Fed Infants (모유 섭취 신생아 유래 Lactobacillus acidophilus에 의한 Conjugated Linoleic Acid 생성)

  • Park, Jeong-Gyu;Song, Won-Ho;Hong, Sung-Moon;Kim, Cherl-Hyun
    • Food Science of Animal Resources
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    • v.28 no.5
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    • pp.580-586
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    • 2008
  • Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds. These conjugated dienes were found to be responsible for many biological properties related to health. The objective of this study was to evaluate the production of cis-9, trans-11 CLA by Lactobacillus acidophilus isolated from breast-fed infants. Nine different cultures were tested for their ability to produce cis-9, trans-11 CLA from free linoleic acid in MRS broth and 8% reconstituted skim milk medium supplemented with linoleic acid at $37^{\circ}C$ for 48 hr. cis-9, trans-11 CLA was not detected or detected in very small amount when cell pellets of strains grown in MRS broth and 8% reconstituted skim milk supplemented with linoleic acid of $200{\mu}g/mL$. However, free cis-9, trans-11 CLA was produced in both media. It appeared that 8% reconstituted skim milk produced more cis-9, trans-11 CLA than MRS broth. L. acidophilus NB 203 and NB 209 produced more cis-9, trans-11 CLA than other tested cultures. The inhibitory effects of supplemented linoleic acid on the growth of L. acidophilus NB 203 and NB 209 were not detected up to $3,000{\mu}g/mL$ linoleic acid addition during the growth at $37^{\circ}C$ for 48 h. The production of cis-9, trans-11 CLA by these two L. acidophilus strains increased in the logarithmic growth phase until 24 hr incubation. Under this experimental condition, the best yield of CLA isomers for L. acidophilus NB 203 and NB 209 could be obtained from medium supplemented with $500{\mu}g/mL$ linoleic acid at $37^{\circ}C$ after 24 hr of incubation. These results indicate that the use of lactic acid bacteria producing free CLA in fermented dairy products may have potential health or nutritional benefits.

Effects of V on the Formation of Ti-Nb-V Cabonitrides and Mechanical Properties in Low Carbon HSLA Steels (저탄소.저합금강의 Ti-Nb-V 복합 탄질화물 형성 및 기계적 특성에 미치는 V 첨가의 효과)

  • Kang, J.S.;Kim, D.J.;Park, C.G.
    • Transactions of Materials Processing
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    • v.15 no.8 s.89
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    • pp.581-585
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    • 2006
  • Effects of V on both the formation of Ti-Nb-V carbonitrides and mechanical properties of Ti-Nb bearing low carbon HSLA steels were investigated. Hot rolling process was simulated by using Gleeble 3500 system with the steels containing three different levels of V ($0{\sim}0.1wt.%$). Vanadium precipitated as Ti-Nb-V carbonitrides at austenite region but it did not precipitate as VC during austenite to acicular ferrite or bainitic ferrite phase transformation. As V content increased, the amount of Nb precipitates was decreased but the average size of Ti-Nb-V carbonitrides was increased due to larger diffusivity of V than that of Nb. Coarsened Ti-Nb-V carbonitrides could act as heterogeneous nucleation site during ${\gamma}{\rightarrow}{\alpha}$ phase transformation, thus, acicular ferrite transformation was promoted as V content increased, resulting in increase of upper shelf energy.

The Effects of Nitrogen on Microstructure and Magnetic Properties of Nanocrystalline Fe-Nb-B-N Thin Films (나노결정구조 Fe-Nb-B-N 박막의 미세구조 및 자기적 특성)

  • 박진영;서수정;노태환;김광윤;김종열;김희중
    • Journal of the Korean Magnetics Society
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    • v.7 no.5
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    • pp.250-257
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    • 1997
  • The microstructure and magnetic properties of Fe-Nb-B-N thin film alloys, which produced by rf magnetron sputtering method in $Ar+N_2$ mixed gas atmosphere, were investigated. The $Fe_{70}Nb_{14}B_{11}N_5$ films, annealed at 59$0^{\circ}C$, exhibit soft magnetic properties: $4{\pi}M_s=16.5kG$ , $H_c=0.13Oe$ and ${\mu}_{eff}$ (1~10 MHz)=5, 000. The frequency stability of the Fe-Nb-B-N films has also been found to be good up to 10 MHz. The Fe-Nb-B-N thin film alloys annealed at 59$0^{\circ}C$ consist of three phase; fine crystalline $\alpha$-Fe phase with grain size of about 5~10 nm, Nb-B rich amorphous phase and Nb-nitride precipitates with the size of less than 3 nm. Annealed Fe-Nb-B films have two phases; $\alpha$-Fe grains with the size of about 10 nm and Nb-B rich amorphous phase. The addition of N decreased $\alpha$-Fe grain size due to the precipitation of NbN. The good magnetic properties of the Fe-Nb-B-N film alloys are due to fine $\alpha$-Fe grains resulting from the precipitation of NbN.

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Synthesis and Electrochemical Properties of FexNbS2/C Composites as an Anode Material for Li Secondary Batteries

  • Kim, Yunjung;Kim, Jae-Hun
    • Corrosion Science and Technology
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    • v.21 no.4
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    • pp.250-257
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    • 2022
  • Transition metal sulfide materials have emerged as a new anode material for Li secondary batteries owing to their high capacity and rate capability facilitated by fast Li-ion transport through the layered structure. Among these materials, niobium disulfide (NbS2) has attracted much attention with its high electrical conductivity and high theoretical capacity (683 mAh g-1). In this study, we propose a facile synthesis of FexNbS2/C composite via simple ball milling and heat treatment. The starting materials of FeS and Nb were reacted in the first milling step and transformed into an Fe-Nb-S composite. In the second milling step, activated carbon was incorporated and the sulfide was crystallized into FexNbS2 by heat treatment. The prepared materials were characterized by X-ray diffraction, electron spectroscopies, and X-ray photoelectron spectroscopy. The electrochemical test results reveal that the synthesized FexNbS2/C composite electrode demonstrates a high reversible capacity of more than 600 mAh g-1, stable cycling stability, and excellent rate performance for Li-ion battery anodes.

Oxygen Chemisorption of NbC(111) Surface Studied by High-Resolution Electron Energy Loss and Ultraviolet Photoelectron Spectroscopy (고분해능 전자에너지손실 및 자외선광전자 분광법을 이용한 NbC(111)면의 산소흡착 연구)

  • Hwang, Yeon;Park, Soon-Ja;Aizawa, Takashi;Hayami, Wataru;Otani, Shigeki;Ishizawa, Yoshio
    • Korean Journal of Materials Research
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    • v.2 no.4
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    • pp.279-284
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    • 1992
  • Oxygen adsorption on the single crystal NbC(111) surface was studied by high-resolution electron energy loss and ultraviolet photoelectron spectroscopy. On the NbC(111) surface, oxygen molecules as well as oxygen atoms were adsorbed. Oxygen atoms were located at the 3-fold hollow site of the NbC(111) surface with the frequency of 548c$m^{-1}$. It was found that oxygen molecules had vibrational frequency of 968c$m^{-1}$which was much lower than that of the free oxygen molecule. Also the work function of the NbC(111) surface has increased by adsorption of oxygen molecule. These suggest electron tranfer from the NbC(111) substrate to the 2p${pi}_g$ substrate of the oxygen molecule.

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Cooperative Priority-based Resource Allocation Scheduling Scheme for D2D Communications Underlaying 5G Cellular Networks (5G 셀룰러 네트워크 하의 D2D통신을 위한 협력적 우선순위 기반의 자원할당 스케줄링)

  • Lee, Chong-Deuk
    • Journal of Digital Convergence
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    • v.18 no.10
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    • pp.225-232
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    • 2020
  • The underlaying communication scheme in 5G cellular network is a very promising resource sharing scheme, and it is an effective scheme for improving service performance of 5G and reducing communication load between a cellular link and a device to device (D2D) link. This paper proposes the algorithm to minimize the resource interference that occurs when performing 5G-based multi-class service on gNB(gNodeB) and the cooperative priority-based resource allocation scheduling scheme (CPRAS) to maximize 5G communication service according to the analyzed control conditions of interference. The proposed CPRAS optimizes communication resources for each device, and it optimizes resource allocation according to the service request required for 5G communication and the current state of the network. In addition, the proposed scheme provides a function to guarantee giga-class service by minimizing resource interference between a cellular link and a D2D link in gNB. The simulation results show that the proposed scheme is better system performance than the Pure cellular and Force cellular schemes. In particular, the higher the priority and the higher the cooperative relationship between UE(User Equipment), the proposed scheme shows the more effective control of the resource interference.

Electrical Characteristics of $Nb/Al-AlO_x/Nb$ Tunnel Junction fabricated with $I_c$ Values in the Range of $28 A/cm^2~ 940 A/cm^2$ ($28 A/cm^2~ 940 A/cm^2$의 임계전류밀도 범위로 제작된 $Nb/Al-AlO_x/Nb$ 터널접합의 전기적 특성)

  • 홍현권;김규태;박세일;김구현;남두우
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.4-7
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    • 2002
  • Samples of $Nb/Al-AlO_x/Nb$ tunnel junction with the size of $50 ${\mu}{\textrm}{m}$ {\times} 50 ${\mu}{\textrm}{m}$$ were fabricated by using self-aligning and reactive ion etching technique In the high quality samples, the $V_m$ value (the product of the critical current and subgap resistance measured at 2 mV) was 34 mV at the critical current density of $J_c: 500 A/cm^2 and the V_g$ value (the gap voltage) was 2.8 mV. For the higher $J_c$ sample, voltage fluctuation at the gap voltage was observed. The $V_m and J_c$ values for this sample were 8 mV and 900 A/cm$^2$, respectively. Also, the relationship between critical current density $J_c$ and specific normal conductance $G_s$ of the junctions with $J_c$ in the range of 28 A/cm$^2$~940 A/cm$^2$was investigated.

Fabrication and Magnetic Process of 13Cr-1.5Nb-Fe Stainless Sensors (13Cr-1.5Nb-Fe 스텐레스 센서재료의 제조 및 연자기특성)

  • 윤성호;김택기;조용수
    • Journal of the Korean Magnetics Society
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    • v.8 no.3
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    • pp.125-130
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    • 1998
  • 13Cr-1.5Nb-Fe alloy powder was fabricated by water atomization method, and ring-shape specimen of this composition was fabricated by oil press, and then sintered in the vacuum furnace. Powder shape, size distribution, composition (C, N, O, S) analysis and saturation magnetization of as-prepared 13Cr-1.5Nb-Fe alloy powder were investigated. Ac permeability and power loss was measured after forming and sintering process. Saturation magnetization and contents of oxygen of the alloy powder is160 emu/g and about 6000 ppm, respectively. 50 % volume fraction indicate particle size of 70$\mu$m. The ac permeability of sintered specimen increases with increasing sintering temperature and forming pressure. The power loss is 107 W/cc at sintering temperature of 1200 $^{\circ}C$, 12 ton/$\textrm{cm}^2$ forming pressure, and 20 KHz. It is the lowest among the prepared specimen.

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