The proposed changes to the definitions of the ampere and kilogram will benefit electrical metrology. Currently, the kilogram is defined by an artifact that may be changing in mass over time. The ampere relies on fixed values of the Josephson and von Klitzing constants. Reducing the uncertainties of these fundamental units will improve measurements. The kilogram will be redefined in terms of the Planck constant via a watt balance. This will increase the uncertainty of disseminating the kilogram standard but not impact most industrial mass measurements.
Electron Diffusion and Phonon Drag Thermopower in Silicon NanowiresAI Publications
The field of thermoelectric research has undergone a renaissance and boom in the fast two decades, largely fueled by the prospect of engineering electronic and phononic properties in nanostructures, among which semiconductor nanowires (NWs) have served both as an important platform to investigate fundamental thermoelectric transport phenomena and as a promising route for high thermoelectric performance for device applications. In this report we theoretical studied the carrier diffusion and phonon-drag contribution to thermoelectric performance of silicon nanowires and compared with the existing experimental data. We observed a good agreement between theoretical data and experimental observations in the overall temperature range from 50 – 350 K. Electron diffusion thermopower is found to be dominant mechanism in the low temperature range and shows linear dependence with temperature.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Electron Diffusion and Phonon Drag Thermopower in Silicon NanowiresAI Publications
The field of thermoelectric research has undergone a renaissance and boom in the fast two decades, largely fueled by the prospect of engineering electronic and phononic properties in nanostructures, among which semiconductor nanowires (NWs) have served both as an important platform to investigate fundamental thermoelectric transport phenomena and as a promising route for high thermoelectric performance for device applications. In this report we theoretical studied the carrier diffusion and phonon-drag contribution to thermoelectric performance of silicon nanowires and compared with the existing experimental data. We observed a good agreement between theoretical data and experimental observations in the overall temperature range from 50 – 350 K. Electron diffusion thermopower is found to be dominant mechanism in the low temperature range and shows linear dependence with temperature.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Pion Form Factor Contribution in Vacuum Polarization corrections for 1s energ...IOSRJAP
The 1푠 energy level vacuum polarization correctionsof pionic hydrogen atom induced by a potential including form factor are compared with those obtained by using pion point potential. Without form factor of nucleus and pion the correction increases very slowly for low Z atoms and increases fastly for higher Z. The finite size of the nucleus increases the correction with Z in case of exponential distribution, while in case of Gaussian distribution the increase is lower. For Fermi distribution there is a fast increase at low values of Z and faslty decreases with higher values of Z. The effect of form factor of pion on the correction is very clear for low Z nuclei and then becomes nearly constant for higher values Z.
This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300841u
Determination of Excited-State Energies and Dynamics in the B Band of the Bacterial Reaction Center with 2D Electronic Spectroscopy
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Quantum Dot-sensitized Solar Cells: A ReviewjournalBEEI
Quantum dot-sensitized solar cell (QDSSC) has an analogous structure and working principle to the dye sensitizer solar cell (DSSC). It has drawn great attention due to its unique features, like multiple exciton generation (MEG), simple fabrication and low cost. The power conversion efficiency (PCE) of QDSSC is lower than that of DSSC. To increase the PCE of QDSSC, it is required to develop new types of working electrodes, sensitizers, counter electrodes and electrolytes. This review highlights recent developments in QDSSCs and their key components, including the photoanode, sensitizer, electrolyte and counter electrode.
This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300541t
Tracking of Proton Transfer Reaction in Supercooled RNA Nucleoside
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Pion Form Factor Contribution in Vacuum Polarization corrections for 1s energ...IOSRJAP
The 1푠 energy level vacuum polarization correctionsof pionic hydrogen atom induced by a potential including form factor are compared with those obtained by using pion point potential. Without form factor of nucleus and pion the correction increases very slowly for low Z atoms and increases fastly for higher Z. The finite size of the nucleus increases the correction with Z in case of exponential distribution, while in case of Gaussian distribution the increase is lower. For Fermi distribution there is a fast increase at low values of Z and faslty decreases with higher values of Z. The effect of form factor of pion on the correction is very clear for low Z nuclei and then becomes nearly constant for higher values Z.
This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300841u
Determination of Excited-State Energies and Dynamics in the B Band of the Bacterial Reaction Center with 2D Electronic Spectroscopy
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Quantum Dot-sensitized Solar Cells: A ReviewjournalBEEI
Quantum dot-sensitized solar cell (QDSSC) has an analogous structure and working principle to the dye sensitizer solar cell (DSSC). It has drawn great attention due to its unique features, like multiple exciton generation (MEG), simple fabrication and low cost. The power conversion efficiency (PCE) of QDSSC is lower than that of DSSC. To increase the PCE of QDSSC, it is required to develop new types of working electrodes, sensitizers, counter electrodes and electrolytes. This review highlights recent developments in QDSSCs and their key components, including the photoanode, sensitizer, electrolyte and counter electrode.
This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300541t
Tracking of Proton Transfer Reaction in Supercooled RNA Nucleoside
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Big Bang–Big Crunch Optimization Algorithm for the Maximum Power Point Track...IJMER
This paper presents an intelligent control method for the maximum power point tracking (MPPT) of a
photovoltaic system under variable temperature and irradiance conditions. The Big Bang–Big Crunch (BB–BC)
optimization algorithm is a new optimization method that relies on the Big Bang and Big Crunch theory, one of the
theories of the evolution of the universe. In this paper, a Big Bang–Big Crunch algorithm is presented to meet the
maximum power operating point whatever the climatic conditions are from simulation results, it has been found that
BB–BC method is highly competitive for its better convergence performance.
Computer simulations of realistic ion channel structures have always been challenging and
a subject of rigorous study. Simulations based on continuum electrostatics have proven to
be computationally cheap and reasonably accurate in predicting a channel’s behavior. In
this paper we discuss the use of a device simulator, SILVACO, to build a solid-state model for
KcsA channel and study its steady-state response. SILVACO is a well-established program,
typically used by electrical engineers to simulate the process flow and electrical characteristics
of solid-state devices. By employing this simulation program, we have presented an
alternative computing platform for performing ion channel simulations, besides the known
methods of writing codes in programming languages. With the ease of varying the different
parameters in the channel’s vestibule and the ability of incorporating surface charges,
we have shown the wide-ranging possibilities of using a device simulator for ion channel
simulations. Our simulated results closely agree with the experimental data, validating our
model.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Fuel Cell Impedance Model Parameters Optimization using a Genetic Algorithm Yayah Zakaria
The objective of this paper is the PEM fuel cell impedance model parameters identification. This work is a part of a larger work which is the diagnosis of the fuel cell which deals with the optimization and the parameters identification of the impedance complex model of the Nexa Ballard 1200 PEM fuel cell. The method used for the identification is a sample genetic algorithm and the proposed impedance model is based on electric parameters, which will be found from a sweeping of well determined frequency bands. In fact, the frequency spectrum is divided into bands according to the behavior of the fuel cell. So, this work is considered a first in the field of impedance spectroscopy So, this work is considered a first in the field of impedance spectroscopy. Indeed, the identification using genetic algorithm requires experimental measures of the fuel cell impedance to optimize and identify the impedance model parameters values. This method is characterized by a good precision compared to the numeric methods. The obtained results prove the effectiveness of this approach.
Fuel Cell Impedance Model Parameters Optimization using a Genetic AlgorithmIJECEIAES
The objective of this paper is the PEM fuel cell impedance model parameters identification. This work is a part of a larger work which is the diagnosis of the fuel cell which deals with the optimization and the parameters identification of the impedance complex model of the Nexa Ballard 1200 W PEM fuel cell. The method used for the identification is a sample genetic algorithm and the proposed impedance model is based on electric parameters, which will be found from a sweeping of well determined frequency bands. In fact, the frequency spectrum is divided into bands according to the behavior of the fuel cell. So, this work is considered a first in the field of impedance spectroscopy So, this work is considered a first in the field of impedance spectroscopy. Indeed, the identification using genetic algorithm requires experimental measures of the fuel cell impedance to optimize and identify the impedance model parameters values. This method is characterized by a good precision compared to the numeric methods. The obtained results prove the effectiveness of this approach.
Dr Ilya Budovsky presented a seminar titled "The Evolution of the Metric System: From Precious Lumps of Metal to Constants of Nature" as part of the SMART Seminar Series on 1st November 2018.
More information:
https://news.eis.uow.edu.au/event/the-evolution-of-the-metric-system-from-precious-lumps-of-metal-to-constants-of-nature/
Keep updated with future events: http://www.uoweis.co/events/category/smart-infrastructure-facility/
The Effect of RF Power on ion current and sheath current by electrical circui...irjes
Plasma is very important in the development of technology as it is applied in many electronic devices
such as global positioning system (GPS). In addition, fusion and process of plasma requires important elements,
namely, the electron energy distribution. However, plasma glow is a relatively new research field in physics.
There has not been found any previous study on the electric plasma modeling. Thus, this study was aimed to
study plasma modeling especially to find out what was the difference in the number of density and the
temperature of the electron in the plasma glow before and after heated and to discover how was the distribution
of electron and ion in the plasma. This research was conducted at Brawijaya University, Malang, Indonesia in
the Faculty of Science. This exploration began in the middle of June 2013. The data collection and data analysis
were done during a year around until August 2014. In this research, characteristics of plasma were studied to
build model of plasma. It utilized MATLAB dialect program examination framework which result in the
distribution of temperature and current density. The findings show that there has been a large increase in the
number of U, U2 with power, while figures of U1 is stable until middle of curve and then decrease as u but u2
after increase at point then stable. The differences appearing are probably due to the simplifying assumptions
considered in the present model. There was a curve between current in sheath and plasma. And time and sheath
current increased in the beginning then decreased before they experienced another increase.
Proposed changes to the definition of the ampere and the kilogram and their influence in electrical and mass measurements
1. Proposed changes to the definition of the ampere and the kilogram and
their influence in electrical and mass measurements
Héctor Laiz
Instituto Nacional de Tecnología Industrial (INTI), Buenos Aires, Argentina, laiz@inti.gob.ar
Abstract: The proposed redefinition of four base units
of the International System of Units (Si) has produced an 2. THE KILOGRAM
exiting scientific debate. The electrical metrology
Although the international prototype has served science
community will benefit from the reduction of the
uncertainty of fundamental measurements related to the SI. and technology during more than one century it has some
inherent limitations. It can be damage, destroyed, it collects
This presentation analyses the alternatives to the dirt from the ambient, and it may change its mass. Its seems
definitions and their impact on electrical and mass that its mass may be changing with respect to the ensemble
metrology. of Pt-Ir standards of about the same age 50 µg per century,
or even more [3].
Keywords: International System of Units. Fundamental
Constants. 3. THE AMPERE
The current definition of the ampere is: the ampere is
1. INTRODUCTION that constant current which, if maintained in two straight
parallel conductors of infinite length, of negligible circular
The International System of Units is a coherent system cross-section, and placed 1 metre apart in vacuum, would
built with base and derived units. The base units are a choice produce between these conductors a force equal to 2 x 10–7
of seven well-defined units which by convention are newton per metre of length [1]. In the past, its direct
regarded as dimensionally independent: the metre, the realization with current balances led to uncertainties of
kilogram, the second, the ampere, the kelvin, the mole, and about 1·10-6. An alternative way with lower uncertainties for
the candela. Derived units are those formed by combining the realization of the SI-ampere is by means of the voltage
base units according to the algebraic relations linking the balance [4] and the Thomsom-Lampard capacitor [5] or the
corresponding quantities [1]. The definition of a base unit is watt balance [6]. The advent of two quantum macroscopic
drawn up so that it is unique and provides a theoretical basis effects, the Josephson and the Quantum Hall Effects, allows
upon which the most accurate and reproducible for the generation of reference voltage an resistance with
measurements can be made. The search for definitions of the high reproducibility, although not in terms of the ampere
units based on invariant of nature is as ancient as human definition, but in terms of the Josephson constant, K J =2e/h
technical activities. The unit of length based on the pharaoh and the von Klitzing constant R K =h/e2. To take full practical
elbow or based on one meridian of the earth are examples of advantage of this two experiments in 1990 the CGPM
that dream [2]. Nowadays we search for definitions of the assigned by convention fixed values to K J and R K , based on
units that relay on fixed values of fundamental constants of all available data from voltage balances, watt balances,
nature. In the definition of the metre, such a fundamental Thomsom-Lampard capacitors and other experiments [7].
constant is the speed of light in vacuum, c o . Another
constant is the permeability of vacuum, µ o , fixed in the
definition of the ampere. Among the seven base units the
definition of the kilogram is the one that is still based on an 4. DRAWBACKS OF THE CURRENT SITUATION
artifact, the international prototype kept at the BIPM in As a consequence of the current definitions of the base
Sèvres, near Paris. Nevertheless, because of the way they are units we face the following problems:
defined, three other base units relay on the definition of the
kilogram, namely the ampere, the mole and the candela. a. The mass of the prototype of the kilogram may be
Therefore, any uncertainty in the definition of the kilogram changing, but its value is fixed by definition.
propagates into these units. Moreover, it is only accessible at the BIPM.
b. We have a practical electrical system of units
“outside de SI”.
VIII Semetro. João Pessoa, PB, Brazil, June 17 – 19, 2009
2. c. The uncertainty given to many fundamental REFERENCES
constants of nature is rather high, due to de null [1] BIPM, “The international System of Units 8th
uncertainty given to the mass of the international edition”(Sevres, France: Bureau International des Poids et
prototype [8]. Measures) www.bipm.org, 2006.
The improvement in the accuracy on some fundamental [2] Valdés J, “Features and Future of the International System
experiments, mainly the watt balance, stimulated the CIPM of Units,” Advances in Imaging and Electron Physics vol
138, ed P Hawkes (New York: Academic) pp 251-320,
to ask its Consultative Committees to study the possibility of
2003.
having a fundamental constant based definition of the [3] Davis R, “The Si unit of mass”, Metrologia, 40 299-305,
kilogram. This decision open and exiting scientific debate 2003.
[2, 8, 9]. [4] Funk T and Sienknecht V, Determination of the volt with
the improved PTB voltage balance,” IEEE Trans. Instrum.
5. IMPACT ON ELECTRICAL MEASUREMENTS Meas., 40 158-161, 1991.
[5] Jeffery A et al, Determination of the von Klitzing constant
Following the inquire of the CIPM, the Consultative and the fine-structure constant through a comparison of the
Committee for Electricity and Magnetism proposed that the quantized Hall resistance and the ohm derived from the
SI be changed by adopting fixed values of the elementary NIST calculable capacitor, Metrologia 35, No 2 (April
charge e and Planck constant h, and that this decision be 1998) 83-96, 1998.
taken in the near future, for example in 2011, provided that [6] Robinson I, “Towards the Redefinition of the Kilogram:
Measurement of Plank´s Constant Using Watt balances,”
adequate agreement is achieved among independent
IEEE Trans. Instrum. Meas., 58 942-948, 2009.
experiments [10]. It also recommends that the ampere be [7] Quinn T, “News from the BIPM”, Metrologia, 26 69-74,
defined, for example, as follows: “The ampere is the 1989.
electrical current equivalent to the flow of exactly 1/(1.602 [8] Mills I. et al, “Redefinition of the kilograma: a decision
176 53 × 10−19)elementary charges per second.” It follows whose time has come,” Metrologia, 2005, 42 71-80, 2005.
that this definition fixes the elementary charge as exactly [9] Becker P et al, “Considerations on future definitions of the
1.602 176 53 × 10−19 A·s. This proposal would give values kilogram, the mole and other units,” Metrologia, 1-14,
without uncertainty to K J and R K , binging electrical units 2007.
back to the SI. [10] CCEM, 2007. RECOMMENDATION E1: Proposed
changes to the International System of Units (SI), ”(Sevres,
The forthcoming change in the SI will not only deal with
France: Bureau International des Poids et Measures)
the ampere and the kilogram but will also include the www.bipm.org
Kelvin, by fixing the value of the Boltzmann constant, and [11] Mills I. et al, “Redefinition of the kilograma, ampere,
the mole, by fixing the value of the Avogadro constant [11]. kelvin and mole: a proposed approach to implementing
CIPM recommendation 1 (C1-2005),” Metrologia, 43 227-
246, 2006.
6. IMPACT ON MASS MEASUREMETS [12] OIML R111 Weights of classes E1, E2, F1, F2, M1, M1-2,
M2, M2-3 and M3. Part 1: Metrological and technical
requirements, International Organization of Legal
According to the proposed changes in the definition of Metrology, http://www.oiml.org/publications/
the units the prototype of the kilogram should be calibrated
with a watt balance in terms of the Plank constant.
Nowadays, the best available watt balance has an
uncertainty of 4·10-8 [6]. This value is 2.5 times the
uncertainty given today by the BIPM for the calibration
kilogram standards made stainless steel. This increase in the
uncertainty will increase the uncertainty in the dissemination
of the national standards to multiples and submultiples but it
will be negligible at the level of E1 standards [12].
7. CONCLUSIONS
The forthcoming change in the definition of the ampere,
the kilogram, the mole and the kelvin, will reduce the
uncertainty of measurements and fundamental constants,
related to the new SI, in many fields of science and
technology. It will increase the uncertainty of mass
measurements at the highest level, but with no impact in
legal and industrial mass measurements.
Attention should be paid in the new definitions to keep
the SI as a widely understandable system, in which
definitions of base units reflect the concept of the related
base quantity.
VIII Semetro. João Pessoa, PB, Brazil, June 17 – 19, 2009