치즈와 치아건강 역할

윤여창,R.S. Patel,E. Renner,S. Singh 한국낙농학회 1992 韓國酪農學會誌 Vol.14 No.4

충치는 식품의 당질과 치아 플라그의 세균 사이의 상호작용의 결과이다. 플라그의 세균은 설탕과 같은 발효 가능한 당질을 유기산으로 분해한다. 이러한 산생성은 플라그의 pH를 저하시켜 충치가 시작되는데, pH 5.7 이상에서 치아는 안전하고 그 이하에서는 충치가 발생할 수 있다. 치즈는 다른 식품과 비교해서 충치효과의 가능성이 가장 적었다. 치즈가 충치효과가 적을 뿐 아니라 충치를 예방할 수 있는 가능성이 충분히 있다. 치즈에 풍부하게 존재하는 칼슘과 인이 이 과정에 작용하여 치아 건강에 탁월한 식품으로서 기능을 수행한다.

Biomolecule-entrapped SiO₂ nanoparticles for ultrafast green synthesis of silver nanoparticle–decorated hybrid nanostructures as effective catalysts

Otari, Sachin V.,Shinde, Vijay V.,Hui, Gao,Patel, Sanjay K.S.,Kalia, Vipin C.,Kim, In-Won,Lee, Jung-Kul Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.5

<P><B>Abstract</B></P> <P>Noble-metal hybrid nanostructures have gained tremendous attention due to their potential roles in biomedical and catalytic applications. In this study, for the synthesis of silver nanoparticles (Ag NPs)–silica (SiO<SUB>2</SUB>) NPs, a novel green chemistry approach was employed, in which green tea biomolecule–encapsulated SiO<SUB>2</SUB> nanostructures were used for the reduction of silver ions to produce hybrid nanostructures within 300 s. The high-resolution transmission electron microscopy (HrTEM) revealed the formation of uniform ultrafine spherical Ag NPs that were evenly distributed in the nanostructures. The formed nanohybrid structures showed efficient catalytic activity for the formation of derivatives of dihydroquinoline, and retained 91% of their reusability capacity, even after 5 repeated cycles. Hence, this work provides a novel synthesis method not only for the synthesis of biomolecule-entrapped SiO<SUB>2</SUB> nanostructures, but also for the rapid formation of catalytically active hybrid nanostructures.</P>

Improvement in methanol production by regulating the composition of synthetic gas mixture and raw biogas

Patel, S.K.S.,Mardina, P.,Kim, D.,Kim, S.Y.,Kalia, V.C.,Kim, I.W.,Lee, J.K. Elsevier Applied Science 2016 Bioresource technology Vol.218 No.-

Raw biogas can be an alternative feedstock to pure methane (CH<SUB>4</SUB>) for methanol production. In this investigation, we evaluated the methanol production potential of Methylosinus sporium from raw biogas originated from an anaerobic digester. Furthermore, the roles of different gases in methanol production were investigated using synthetic gas mixtures of CH<SUB>4</SUB>, carbon dioxide (CO<SUB>2</SUB>), and hydrogen (H<SUB>2</SUB>). Maximum methanol production was 5.13, 4.35, 6.28, 7.16, 0.38, and 0.36mM from raw biogas, CH<SUB>4</SUB>:CO<SUB>2</SUB>, CH<SUB>4</SUB>:H<SUB>2</SUB>, CH<SUB>4</SUB>:CO<SUB>2</SUB>:H<SUB>2</SUB>, CO<SUB>2</SUB>, and CO<SUB>2</SUB>:H<SUB>2</SUB>, respectively. Supplementation of H<SUB>2</SUB> into raw biogas increased methanol production up to 3.5-fold. Additionally, covalent immobilization of M. sporium on chitosan resulted in higher methanol production from raw biogas. This study provides a suitable approach to improve methanol production using low cost raw biogas as a feed containing high concentrations of H<SUB>2</SUB>S (0.13%). To our knowledge, this is the first report on methanol production from raw biogas, using immobilized cells of methanotrophs.

Nonlinear dynamic buckling of laminated angle-ply composite spherical caps

Gupta, S.S.,Patel, B.P.,Ganapathi, M. Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.15 No.4

This paper deals with nonlinear asymmetric dynamic buckling of clamped laminated angle-ply composite spherical shells under suddenly applied pressure loads. The formulation is based on first-order shear deformation theory and Lagrange's equation of motion. The nonlinearity due to finite deformation of the shell considering von Karman's assumptions is included in the formulation. The buckling loads are obtained through dynamic response history using Newmark's numerical integration scheme coupled with a Newton-Raphson iteration technique. An axisymmetric curved shell element is used to investigate the dynamic characteristics of the spherical caps. The pressure value beyond which the maximum average displacement response shows significant growth rate in the time history of the shell structure is considered as critical dynamic load. Detailed numerical results are presented to highlight the influence of ply-angle, shell geometric parameter and asymmetric mode on the critical load of spherical caps.

Nanoparticles in Biological Hydrogen Production: An Overview

Patel, Sanjay K. S.,Lee, Jung-Kul,Kalia, Vipin C. Springer-Verlag 2018 Indian journal of microbiology Vol.58 No.1

<P>Biological hydrogen (H-2) production enhancement through the use of nanoparticles (NPs) supplement in the media is being recognized as a promising approach. The NPs, including those of metal and metal oxides have shown a significant improvement in the BHP. A number of organisms as pure or mixed cultures can produce H-2 in presence of NPs from pure sugars and biowaste as a feed. However, their H-2 production efficiencies have been found to vary significantly with the type of NPs and their concentration. In this review article, the potential role of NPs in the enhancement of H-2 production has been assessed in dark- and photo-fermentative organisms using sugars and biowaste materials as feed. Further, the integrative approaches for commercial applications of NPs in BHP have been discussed.</P>

Enhancement of methanol production from synthetic gas mixture by Methylosinus sporium through covalent immobilization

Patel, S.K.S.,Selvaraj, C.,Mardina, P.,Jeong, J.H.,Kalia, V.C.,Kang, Y.C.,Lee, J.K. Applied Science Publishers 2016 APPLIED ENERGY Vol.171 No.-

<P>Both methane (CH4) and carbon dioxide (CO2) are major greenhouse gases (GHGs); hence, effective processes are required for their conversion into useful products. CH4 is used by a few groups of methanotrophs to produce methanol. However, to achieve economical and sustainable CH4 reduction strategies, additional strains are needed that can exploit natural CH4 feed stocks. In this study, we evaluated methanol production by Methylosinus sporium from CH4 and synthetic gas. The optimum pH, temperature, incubation period, substrate, reaction volume to headspace ratio, and phosphate buffer concentration were determined to be 6.8, 30 C, 24 h, 50% CH4, 1:5, and 100 mM (with 20 mM MgC12 [a methanol dehydrogenase inhibitor]), respectively. Optimization of the production conditions and process parameters significantly improved methanol production from 0.86 mM to 5.80 mM. Covalent immobilization of M. sporium on Chitosan significantly improved the stability and reusability for up to 6 cycles of reuse under batch culture conditions. The immobilized cells utilized a synthetic gas mixture containing CH4, CO2, and hydrogen (at a ratio of 6:3:1) more efficiently than free cells, with a maximum methanol production of 6.12 mM. This is the first report of high methanol production by M. sporium covalently immobilized on a solid support from a synthetic gas mixture. Utilization of cost-effective feedstocks derived from natural resources will be an economical and environmentally friendly way to reduce the harmful effects of GHGs. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Inelastic stability analysis of high strength rectangular concrete-filled steel tubular slender beam-columns

Patel, Vipulkumar Ishavarbhai,Liang, Qing Quan,Hadi, Muhammad N.S. Techno-Press 2012 Interaction and multiscale mechanics Vol.5 No.2

There is relatively little numerical study on the behavior of eccentrically loaded high strength rectangular concrete-filled steel tubular (CFST) slender beam-columns with large depth-to-thickness ratios, which may undergo local and global buckling. This paper presents a multiscale numerical model for simulating the interaction local and global buckling behavior of high strength thin-walled rectangular CFST slender beam-columns under eccentric loading. The effects of progressive local buckling are taken into account in the mesoscale model based on fiber element formulations. Computational algorithms based on the M$\ddot{u}$ller's method are developed to obtain complete load-deflection responses of CFST slender beam-columns at the macroscale level. Performance indices are proposed to quantify the performance of CFST slender beam-columns. The accuracy of the multiscale numerical model is examined by comparisons of computer solutions with existing experimental results. The numerical model is utilized to investigate the effects of concrete compressive strength, depth-to-thickness ratio, loading eccentricity ratio and column slenderness ratio on the performance indices. The multiscale numerical model is shown to be accurate and efficient for predicting the interaction buckling behavior of high strength thin-walled CFST slender beam-columns.

Traveling Theta Waves along the Entire Septotemporal Axis of the Hippocampus

Patel, J.,Fujisawa, S.,Berenyi, A.,Royer, S.,Buzsaki, G. Cell Press 2012 Neuron Vol.75 No.3

A topographical relationship exists between the hippocampus-entorhinal cortex and the neocortex. However, it is not known how these anatomical connections are utilized during information exchange and behavior. We recorded theta oscillations along the entire extent of the septotemporal axis of the hippocampal CA1 pyramidal layer. While the frequency of theta oscillation remained same along the entire long axis, the amplitude and coherence between recording sites decreased from dorsal to ventral hippocampus (VH). Theta phase shifted monotonically with distance along the longitudinal axis, reaching ~180<SUP>o</SUP> between the septal and temporal poles. The majority of concurrently recorded units were phase-locked to the local field theta at all dorsoventral segments. The power of VH theta had only a weak correlation with locomotion velocity, and its amplitude varied largely independently from theta in the dorsal part. Thus, theta oscillations can temporally combine or segregate neocortical representations along the septotemporal axis of the hippocampus.

Development of a Triggering Arrangement For the KALI-30GW MARX Generator

S. Mitra,T. S. Kolge,Ritu Agarwal,P. C. Saroj,Ankur Patel,K. Senthil,Vishnu Sharma,S. V. Tewari,Archana Sharma,K. C. Mittal 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.4

This paper reports the design methodology and implementation experiments for a solid-statebasedtriggering arrangement for the MARX generator of the KALI-30GW (1 MV, 30 kA, 80 ns)pulsed power system. The 15-stage bipolar MARX generator of the KALI-30GW system is triggeredusing a trigatron-type spark gap. An insulated-gate bipolar-transistor (IGBT)-based trigger supplyis used to trigger the first spark gap, and the next two spark gaps are triggered by using internallygeneratedtrigger pulses. Optically-isolated arrangements are provided for a human interface. Theentire assembly was tested with a dummy copper sulphate load, and an excellent triggering rangeof 7 − 12 kV was achieved. The circuit diagram, analysis and experimental results of the triggeringarrangement are presented in the paper.

Final report on APMP supplementary comparison P1-APMP.EM.RF-S3: APMP comparison of 50 ohm coaxial mismatches

Patel, Kamlesh,Negi, P S,Swarup, Ram,Kim, Jeong Hwan,Kang, Jin-Seob,Chow, Michael W K,Tsui, C M,Dressler, Erik,Shay, Wen-Tron,Li, Hua,Shan, Yueyan Springer-Verlag 2012 METROLOGIA -BERLIN- Vol.49 No.-

<P>A measurement comparison of complex reflection coefficient has been carried out among six national metrology laboratories in coaxial system at frequencies of 50 MHz, 2 GHz, 10 GHz and 18 GHz. Three 50 Ω coaxial mismatches (voltage standing wave ratios 1.2, 1.5 and 2.0) in 7 mm connectors have been measured for their complex reflection coefficients in the magnitude and phase form. The six laboratories participated are NPL India, KRISS Korea, SCL Hong Kong, CMS ITRI Taiwan, NMC Singapore and CSIR-NML South Africa (now NMISA). The National Physical Laboratory (India) acted as the pilot laboratory for the comparison. Good agreement between the values provided by the participating laboratories has been observed: the degrees of equivalence for all the values reported, with respect to the reference value and between pairs of laboratories, are less than their associated uncertainties, at a level of confidence of 95%.</P><P>Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.</P><P>The final report has been peer-reviewed and approved for publication by APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>