Search results for "EFFICIENT"
showing 10 items of 1603 documents
Influence of temperature on mass transfer in an incomplete trapping single hollow fibre supported liquid membrane extraction of triazole fungicides.
2008
The influence of temperature in a single hollow fibre supported liquid membrane extraction of triazole fungicides with a stagnant acceptor phase was investigated. The mass transfer parameters such as diffusion coefficient, flux and apparent viscosity were determined at temperature ranging from 278 K to 313 K. Increase in temperature led to an increase in diffusion coefficient and flux. The apparent viscosity also decreased with an increase in temperature. The degree of trapping in the acceptor phase influenced the mass transfer at higher temperature. At lower temperature, the transport of analytes from the donor solution through the donor-membrane interface and through the membrane mainly a…
Adsorption and desorption surface dynamics of gaseous adsorbate on silicate-1 by molecular dynamics simulation
2013
The dynamics of adsorption and desorption of gaseous molecules on the external surface of a crystal and a membrane of zeolite silicate-1 is investigated by molecular dynamics simulation. The gases ...
Direct arylation of heteroaromatic compounds with congested, functionalised aryl bromides at low palladium/triphosphane catalyst loading.
2011
International audience; A new ferrocenyl triphosphane ligand associated to palladium was found to be an efficient catalyst for the direct coupling of highly congested, functionalised aryl bromides with a variety of heteroarenes. These coupling reactions can generally be performed by using a low-loading (0.1-0.5 mol%) of the catalyst. The present protocol tolerates important and useful functional groups, which allows for further elaboration into more sophisticated heterocyclic molecules. The straightforward arylation of heteroaromatic compounds with congested ortho-substituted aryl bromides may permit further convergent syntheses of diverse ligands, biologically active molecules and molecula…
STUDY REGARDING THE MARKOWITZ MODEL OF PORTFOLIO SELECTION
2015
The Markowitz model was introduced through the work of Harry Markowitz (1952) and analyzes the risk and the rentability of a diversified portfolio of securities. In our research, we want to use the Markowitz model in order to identify the structure of the optimal portfolio of risky assets, in other words the efficient portofolio. The study, conducted on three romanian companies from the construction sector, listed on the Bucharest Stock Exchange, leads to the conclusion that the portfolio is illegitimate, so it is necessary to sell the securities of the companies in the absence, procedure known as short sell.
Asymptotic theory of resonant tunneling in quantum waveguides of variable cross-section
2008
Halkaisijaltaan muunnellun kvanttiaaltojohtimen kapenemat toimivat tehokkaina potentiaalivalleina elektronin pitkittäissuuntaiselle liikkeelle. Kaksi kapenemaa muodostaa kvanttiresonaattorin, jossa resonoiva tunnelointi voi tapahtua. Tämä tarkoittaa sitä, että elektronit, joiden energia on lähellä resonanssia, läpäisevät resonaattorin todennäköisyydellä lähellä yhtä.Sarafanov kuvailee väitöskirjassaan asymptoottisesti elektroniaallon etenemistä kvanttiaaltojohtimessa, jossa on kaksi kapenemaa. Aaltoluvun k oletetaan olevan ensimmäisen ja toisen kynnysluvun välissä, jolloin vain sisään tuleva ja poismenevä aalto voivat edetä jokaisessa aaltojohtimen päässä äärettömyydessä. Väitöskirjassa esi…
The Development and Precision of a Custom-Made Skitester
2021
In the sport of cross-country skiing, equipment has a direct influence on results. Ski teams do extensive testing of different ski base grinds and products on a yearly basis. To achieve reliable results, the quality of methods used for testing skis needs to be taken in to account in addition to factors including the physical characteristics of testing personnel and changes in weather conditions. The aim of this study was to introduce a custom-made skitester, that was developed for testing skis on real snow, in laboratory conditions, and to evaluate its precision. The current skitester is capable of glide testing both classic and skate skis as well as kick simulation for the testing of grip …
A delay model valid in all the regions of operation of the MOS transistor for the energy-efficient design of MCML gates
2013
This paper presents a novel delay model for MCML circuits valid in all the regions of operation of the MOS transistor, i.e., weak inversion (sub-threshold), moderate inversion (near-threshold) and strong inversion. The proposed delay model was employed to develop an automated methodology for the energy-efficient design of such circuits. The tradeoff that can be realized between energy and delay was investigated. Experiments were performed using different technologies to understand the impact of technology scaling on that tradeoff too. Major results of this study are as follows. In a circuit designed for minimum energy consumption, the minimum energy point occurs in the near-threshold region…
kLa MEASUREMENT IN BIOREACTORS
2010
For accurately measuring kLa in bioreactors the dynamic pressure method (DPM) was introduced by Linek et al. (1993). In this work a simplified version of the same method is discussed. With respect to the original DPM, the simplified version greatly simplifies data treatment. In fact final constant slope observable in the usual semi-log diagram of residual driving force versus time may be simply corrected to obtain the real kLa value with negligible inaccuracy. Experimental data obtained on a lab-size stirred tank reactor confirm all model predictions, including the feature that the adoption of large pressure changes may lead to a better accuracy.
Internal heat gain from different light sources in the building lighting systems
2017
EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and t…
Leading agritourism facilities along Nearly Zero Energy paths: proposal of an easy-to-use evaluation method
2020
The tourist sector, despite the present severe constraints imposed by the sanitary emergence, can be considered as an important component of almost all countries’ economies. In Italy agriturism, in particular, has been experiences a continuously rising trend in recent years. Clearly, such great interest towards these businesses also calls for a deep attention by an energy point of view, in sight of an energy efficiency improvement, hence a lowering of the pressure that such facilities exert to the natural environment. On the other hand, the European Union has been engaged, for a long time, in awarding the tourist accommodations environmental excellence brands, like the EU Ecolabel. Unfortun…