1,561 research outputs found
Canonical-grandcanonical ensemble in-equivalence in Fermi systems?
I discuss the effects of fermionic condensation in systems of constant
density of states. I show that the condensation leads to a correction of the
chemical potential and of the Fermi distribution in canonical Fermi systems at
low temperatures. This implies that the canonical and grandcanonical ensembles
are not equivalent even for Fermi systems.Comment: 4 pages and 1 figur
Fluctuations of the Fermi condensate in ideal gases
We calculate numerically and analytically the fluctuations of the fermionic
condensate and of the number of particles above the condensate for systems of
constant density of states. We compare the canonical fluctuations, obtained
from the equivalent Bose condensate fluctuation, with the grandcanonical
fermionic calculation. The fluctuations of the condensate are almost the same
in the two ensembles, with a small correction comming from the total particle
number fluctuation in the grandcanonical ensemble. On the other hand the number
of particles above the condensate and its fluctuation is insensitive to the
choice of ensemble.Comment: 10 pages with 3 figs. IOP styl
Exploring student perspectives on the extended program
Abstract: Many students find the transition from high school to university difficult specifically in engineering. It has been established that there is a gap in mathematics ability between high school and university. Internationally the high school curricula focuses on increasing access to tertiary institutions. Many of these curricula teach superficial learning to high school students. At University level deep learning is required. Students who do not meet entry requirements for engineering first year have the option to enter an extended program. This paper explores whether the extended program offered at the University of Johannesburg for mechanical and industrial engineering students is perceived as beneficial. A survey was conducted on first and second year students that started their qualification with the extended program. The results were statistically analysed. Information from the Higher Education Management Information System (HEMIS) system was used to compare performance of students who completed the extended program and those in the mainstream. Based on the research it seems that the extended program does benefit students
Universal behaviour of ideal and interacting quantum gases in two dimensions
I discuss ideal and interacting quantum gases obeying general fractional
exclusion statistics. For systems with constant density of single-particle
states, described in the mean field approximation, the entropy depends neither
on the microscopic exclusion statistics, nor on the interaction. Such systems
are called {\em thermodynamically equivalent} and I show that the microscopic
reason for this equivalence is a one-to-one correspondence between the excited
states of these systems. This provides a method, different from the
bosonisation technique, to transform between systems of different exclusion
statistics. In the last section the macroscopic aspects of this method are
discussed.
In Appendix A I calculate the fluctuation of the ground state population of a
condensed Bose gas in grandcanonical ensemble and mean field approximation,
while in Appendix B I show a situation where although the system exhibits
fractional exclusion properties on microscopic energy intervals, a rigorous
calculation of the population of single particle states reveals a condensation
phenomenon. This also implies a malfunction of the usual and simplified
calculation technique of the most probable statistical distributions.Comment: About 14 journal pages, with 1 figure. Changes: Body of paper: same
content, with slight rephrasing. Apendices are new. In the original
submission I just mentioned the condensation, which is now detailed in
Appendix B. They were intended for a separate paper. Reason for changes:
rejection from Phys. Rev. Lett., resubmission to J. Phys. A: Math. Ge
Malignant tumor with different localisation after klatskin tumor succesfully resected
Institutul Clinic Fundeni, Clinica Chirurgie Generală și Transplant Hepatic “Dan Setlacec”, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Prezentare de caz: tumora Klatskin IIIb rezecată cu evoluția postoperatorie bună, diagnosticat la 3 ani cu tumoră gastrică.Case report: IIIb Klatskin tumor successfully resected with good postoperative outcome is diagnosed 3 years later with a gastric tumor
Dependable workflow management system for smart farms
Smart Farming is a new and emerging domain representing the application of modern technologies into agriculture, leading to a revolution of this classic domain. CLUeFARM is a web platform in the domain of smart farming which main purpose is to help farmers to easily manage and supervise their farms from any device connected to the Internet, offering some useful services. Cloud technologies evolved a lot in recent years and based on this growth, microservices are more and more used. If for the server side, the scalability and reusability are solved in high proportion by microservices, on the client side of web applications, there was no independent solution until the recent emergence of web components. They can be seen as the microservices of the front-end. Microservices and web components are usually used isolated one of each other. This paper proposes and presents the functionality and implementation of a dependable workflow management service by using an end-to-end microservices approach
Operation of Circuit Breakers: Data and Analysis
[EN] An attempt has been made for the analysis on Circuit breakers (CBs) this paper. First, the types and arcing phenomenon of Oil and SF6 Circuit breakers were briefly discussed. However, various CBs were analyzed in terms of certain outage frequencies and reliability indices to ascertain the most reliable CB. This was possible using data collected from the 33kV Transmission Company of Nigeria (TCN) New Haven, Enugu. After the analysis, Emene Industrial CB had the highest value of availability of 0.9999 and the lowest tripping report while Ezillo had the highest failure rate of 0.1032.The authors are immensely grateful for the financial support from “African Centre of Excellence (ACE-SPED) University of Nigeria, Nsukka” to enable us to achieve the research (Muncho J. Mbunwe et al., 2019-2021).Madueme, VC.; Mbunwe, MJ.; Madueme, TC.; Ahmad, MA.; Anghel Drugarin, CV. (2021). Operation of Circuit Breakers: Data and Analysis. Multidisciplinary Journal for Education, Social and Technological Sciences. 8(2):60-73. https://doi.org/10.4995/muse.2021.12406OJS607382Anyaka, B.O. (2012). Reliability and Maintainability of Power System [Lecture Note]. http://engineering.unn.edu.ngCircuit globe, (n.d.). Circuit breaker, Retrieved June 10, 2017, from open source:- http://circuitglobe.com/circuit-breaker.htmlElectrical concepts, Circuit breaker and Arc Phenomenon, (n.d.). Retrieved June 10, 2017, from open source: http://electricalbaba.com/circuit-breaker-and-arc-phenomenon/Electrical Systems, (n.d.). Retrieved June 10, 2017, from open source: http://skm-eleksys.com/2012/02/sf6-circuit-breaker-working.htmlKezunovic, M. Ren, Z. Latisko, G. Sevcik, D.R. Lucey, J.S. Cook, W.E. and Koch, E.A. (2005). Automated Monitoring and Analysis of Circuit Breaker Operation, IEEE Transactions on Power Delivery, 20(3), p. 1910. https://doi.org/10.1109/TPWRD.2005.848466Pinnekamp, F. (2007). The circuit breaker: a showcase of industrial product development, Transmission group R&D and technology, ABB, Switzerland, p.31. https://new.abb.com/docs/default-source/technology/brosch%C3%BCre-chchrc2017final-einseitig-(002).pdf?sfvrsn=e3f37d14_2Saxena, S. Singh, A. Ali, M. Gandhi, K. (2012). Various Types of Circuit Breakers used in Power System for Smooth Working of the Transmission Line, MIT International Journal of Electrical and Instrumentation Engineering, 2(2), p. 106. https://www.semanticscholar.org/paper/06918326da2b2ac6fd80620d88961b68554b72edSuwanasri, T. Hlaing, M.T. and Suwanasri, C. (2014). Failure Rate Analysis of Power Circuit Breaker in High Voltage Substation, GMSARN International Journal, 8(1), 1-6. http://gmsarnjournal.com/home/journal-vol/journal-vol-8-no-1/Transmission Company of Nigeria. (2016). Tripping reports April - June 2016 [Unpublished Raw data]. New Haven, Enugu, Nigeria. https://www.tcn.org.ng/page_history.phpMuncho J. Mbunwe, M. Ayaz Ahmad, Syed Khalid Mustafa. (2020). An effective energy saving design strategy to maximize the use of electricity, J. Math. Comput. Sci., 10(5), 1808-1833, https://doi.org/10.28919/jmcs/4775Mbunwe Muncho J., Ezema Ejiofor E., Ngwu Anene A., C V Anghel Drugarin, M. Rehan Ajmal, M Ayaz Ahmad. (2021). Characterization of three phase solid state VAR compensation scheme in three phase pulse width modulation voltage source inverter, Journal of Physics: Conference Series, Vol. 1781, 012034, https://doi.org/10.1088/1742-6596/1781/1/012034M. Ayaz Ahmad, Irina Tvoroshenko, Jalal Hasan Baker, Vyacheslav Lyashenko. (2019). Modeling the Structure of Intellectual Means of Decision-Making Using a System Oriented NFO Approach, International Journal of Emerging Trends in Engineering Research , Vol. 7(11), 460-465. https://doi.org/10.30534/ijeter/2019/107112019Mykhailo Kopot, M. Ayaz Ahmad, Vyacheslav Lyashenko, Syed Khalid Mustafa. (2020). Prospects for Creating Sub-Millimeter Magnetrons, International Journal of Advanced Trends in Computer Science and Engineering, Vol. 9(4), 6184-6188. https://doi.org/10.30534/ijatcse/2020/294942020M. Ayaz Ahmad, Irina Tvoroshenko, Jalal Hasan Baker, Vyacheslav Lyashenko. (2019). Computational Complexity of the Accessory Function Setting Mechanism in Fuzzy Intellectual Systems, International Journal of Advanced Trends in Computer Science and Engineering, Vol. 8(5), 2370-2377. https://doi.org/10.30534/ijatcse/2019/77852019Muncho J. Mbunwe, Udochukwu B. Akuru, Hilary U. Ezea, Ogbonnaya I. Okoro, M. Ayaz Ahmad. (2020). Some Aspects of Future Energy Generation in Using of Solar Power Satellites, Int. J. Anal. Appl., 18 (1), 117-128. https://doi.org/10.28924/2291-8639-18-2020-11
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