• Title/Summary/Keyword: energy-free

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A CRITICAL NOTE ON THE CONCEPT OF THE CONVENTIONAL INTEGRAL ELECTRIC POWER METERING (기존의 적산전력계측 개념의 새로운 평가)

  • Oh, Hung-Kuk
    • Proceedings of the KIEE Conference
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    • 2001.04a
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    • pp.171-173
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    • 2001
  • Conventional potential concept does not allow different currents before and after the electric load. Experimental examples in case of bioloads show a lot of different currents before and after the bioload, which means that the true potential concept is not the conventional concept from Coulomb attraction energy but the new concept from Gibb's free energy. Gibb's free energy is a kind of potential heat energies and also they are rotating electromagnetic waves. We might think that electric current is not a flow of electrons but a flow of rotating electromagnetic waves, which induces electrons' vibrations. A new measuring method for integral electrical power is suggested for the new Gibb's free energy concept.

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Conformational Analysis of Sulfonylureas : Acetohexamide and Tolazamide (Sulfonylurea 유도체들의 구조분석 : Acetohexamide와 Tolazamide)

  • 정우태;강기롱;이성희
    • YAKHAK HOEJI
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    • v.39 no.3
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    • pp.329-336
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    • 1995
  • Conformational free energy calculations using an empirical potential function and a hydration shell model(program CONBIO) were carried out on hypoglycemic agent acetohexamide and tolazamide in the unhydrated and hydrated states. The initial geometry of sulfonylureas was obtained from X-ray crystallographieal data and homologous molecular fragments. In both states, the feasible conformations were obtained from the calculations of conformational energy, conformational entropy, and hydration free energy by varying all the torsion angles of the molecules. From the calculation results, it is known that the conformations] entropy is the major contribution to stabflize the low-free-energy conformations of two sulfonylureas in both states. But, in hydrated state, the hydration does not directly affect each conformations. The intramolecular hydrogen bonding of sulfonylurea hydrogen and 7-membered nitrogen appeared to the conformations of tolazamide in both states. It is thought that the hydrogen bonding decrease steric hindrance on the receptor binding direction. The substitution of alicyclic or N-heterocyclic ring than that of carbons chain of urea moiety may be properly interaction between sulfonylureas and the putative pancreatic receptor.

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Continuous Cell-Free Protein Synthesis Using Glycolytic Intermediates as Energy Sources

  • Kim, Ho-Cheol;Kim, Tae-Wan;Park, Chang-Gil;Oh, In-Seok;Park, Kyung-Moon;Kim, Dong-Myung
    • Journal of Microbiology and Biotechnology
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    • v.18 no.5
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    • pp.885-888
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    • 2008
  • In this work, we demonstrate that glycolytic intermediates can serve as efficient energy sources to regenerate ATP during continuous-exchange cell-free (CECF) protein synthesis reactions. Through the use of an optimal energy source, approximately 10 mg/ml of protein was generated from a CECF protein synthesis reaction at greatly reduced reagent costs. Compared with the conventional reactions utilizing phosphoenol pyruvate as an energy source, the described method yields 10-fold higher productivity per unit reagent cost, making the techniques of CECF protein synthesis a more realistic alternative for rapid protein production.

Energy Dissipation of Water Flow over a Drop

  • Lee, Jiyong;Lim, Yosup;Jang, Jinhee;Kang, Seokkoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.375-379
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    • 2016
  • Recently derived energy dissipation equation by Chamani(2008) and the profile function of the free overfall by Marchi(1993) were verified with present experiment data. The experiment was conducted in hydraulic laboratory, Hanyang University where the flume is 7m long and 0.44m wide, and the height of the drop structure is 0.205m. Water depth and free overfall profile data were collected using an ultra sonic distance sensor and photographic images. The time-averaged water depth data and the free overfall profile were analyzed to examine the energy dissipation pattern over the drop structure

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The Dark Energy Research Using Type Ia Supernovae in the GMT Era: The Evolution-Free and Dust-Free Test

  • Kim, Young-Lo;Kang, Yijung;Lim, Dongwook;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.59.2-59.2
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    • 2013
  • The luminosity evolution of Type Ia supernova (SN Ia) and dust extinction play major roles in the systematic uncertainties in the SN cosmology. In order to overcome these obstacles, here we propose to use GMT-GMACS to take spectra for early-type host-galaxies of SNe Ia in the redshift range between 0.2 and 1.0. This high-redshift sample will be taken from Dark Energy Survey (DES), which expects more than 200 early-type hosts at this redshift range. They will be compared with nearby early-type hosts, for which we are now obtaining low-resolution spectra. We will select host-galaxies of same population age range for both nearby and high-redshift samples to reduce the possible evolution effect. Since we are dealing with early-type galaxies, our test is also less affected by dust extinction. We expect that our evolution-free and dust-free dark energy test will provide more robust results on the nature of dark energy.

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The Molecular Modeling of Novel Inhibitors of Protein Tyrosine Phosphatase 1B Based on Catechol by MD and MM-GB (PB)/SA Calculations

  • Kocakaya, Safak Ozhan
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1769-1776
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    • 2014
  • Binding modes of a series of catechol derivatives such as protein tyrosine phosphatase 1B (PTP1B) inhibitors were identified by molecular modeling techniques. Docking, molecular dynamics simulations and free energy calculations were employed to determine the modes of these new inhibitors. Binding free energies were calculated by involving different energy components using the Molecular Mechanics-Poisson-Boltzmann Surface Area and Generalized Born Surface Area methods. Relatively larger binding energies were obtained for the catechol derivatives compared to one of the PTP1B inhibitors already in use. The Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) free energy decomposition analysis indicated that the hydroxyl functional groups and biphenyl ring system had favorable interactions with Met258, Tyr46, Gln262 and Phe182 residues of PTP1B. The results of hydrogen bound analysis indicated that catechol derivatives, in addition to hydrogen bonding interactions, Val49, Ile219, Gln266, Asp181 and amino acid residues of PTP1B are responsible for governing the inhibitor potency of the compounds. The information generated from the present study should be useful for the design of more potent PTP1B inhibitors as anti-diabetic agents.

Operation of Battery Energy Storage System for Governor Free and its Effect (주파수추종 운전 적용을 위한 BESS의 운용 방법 및 효과)

  • Cho, Sung-Min;Jang, Byung-Hoon;Yoon, Yong-Bum;Jeon, Woong-Jae;Kim, Chulwoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.16-22
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    • 2015
  • As the development of Battery Energy Storage System(BESS) and the increasing of intermittent energy sources like wind power and photovoltaic, the application of BESS in load frequency control is considered as an effective method. To evaluate the effectiveness of BESS application in frequency control, we defined a governor free model of BESS to conduct dynamic simulation. Using the BESS dynamic model, we implemented the power system dynamic model including steam, gas and hydro turbine generators. In this paper we study the control performance of BESS in primary frequency control. The effect of BESS speed regulation rate and response time on governor free operation is investigated. In addition, we compared BESS from steam turbine generator in view point of frequency regulation.

Free axial vibration of cracked axially functionally graded nanoscale rods incorporating surface effect

  • Nazemnezhad, Reza;Shokrollahi, Hassan
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.449-462
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    • 2020
  • This work aims to study effects of the crack and the surface energy on the free longitudinal vibration of axially functionally graded nanorods. The surface energy parameters considered are the surface stress, the surface density, and the surface Lamé constants. The cracked nanorod is modelled by dividing it into two parts connected by a linear spring in which its stiffness is related to the crack severity. The surface and bulk material properties are considered to vary in the length direction according to the power law distribution. Hamilton's principle is implemented to derive the governing equation of motion and boundary conditions. Considering the surface stress causes that the derived governing equation of motion becomes non-homogeneous while this was not the case in works that only the surface density and the surface Lamé constants were considered. To extract the frequencies of nanorod, firstly the non-homogeneous governing equation is converted to a homogeneous one using an appropriate change of variable, and then for clamped-clamped and clamped-free boundary conditions the governing equation is solved using the harmonic differential quadrature method. Since the present work considers effects of all the surface energy parameters, it can be claimed that this is a comprehensive work in this regard.

Improved Adhesion of Solar Cell Cover Glass with Surface-Flourinated Coating Using Atmospheric Pressure Plasma Treatment (상압 플라즈마 표면처리를 통한 태양광모듈 커버글라스와 불소계 코팅의 응착력 향상)

  • Kim, Taehyeon;Park, Woosang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.4
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    • pp.244-248
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    • 2018
  • We propose a method for improving the reliability of a solar cell by applying a fluorinated surface coating to protect the cell from the outdoor environment using an atmospheric pressure plasma (APP) treatment. An APP source is operated by radio frequency (RF) power, Ar gas, and $O_2gas$. APP treatment can remove organic contaminants from the surface and improve other surface properties such as the surface free energy. We determined the optimal APP parameters to maximize the surface free energy by using the dyne pen test. Then we used the scratch test in order to confirm the correlation between the APP parameters and the surface properties by measuring the surface free energy and adhesive characteristics of the coating. Consequently, an increase in the surface free energy of the cover glass caused an improvement in the adhesion between the coating layer and the cover glass. After treatment, adhesion between the coating and cover glass was improved by 35%.

Application of differential transformation method for free vibration analysis of wind turbine

  • Bozdogan, Kanat Burak;Maleki, Farshid Khosravi
    • Wind and Structures
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    • v.32 no.1
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    • pp.11-17
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    • 2021
  • In recent years, there has been a tendency towards renewable energy sources considering the damages caused by non-renewable energy resources to nature and humans. One of the renewable energy sources is wind and energy is obtained with the help of wind turbines. To determine the behavior of wind turbines under earthquake loads, dynamic characteristics are required. In this study, the differential transformation method is proposed to determine the free vibration analysis of wind turbines with a variable cross-section. The wind turbine is modeled as an equivalent variable continuous flexural beam and blade weight is considered as a point mass at the top of the structures. The differential equation representing the free vibration of the wind turbine is transformed into an algebraic equation with the help of differential transformation method and the angular frequencies and the mode shapes of the wind turbine are obtained by the help of the differential transformation method. In the study, a sample taken from the literature was solved with the presented method and the suitability of the method was investigated. The same wind turbine example also modeled by finite element modelling software, ABAQUS. Results of the finite element model and differential transformation method are compared with each other and the results are in good agreement.