Energy and thermodynamical study of a small innovative compressed air energy storage system (micro-CAES)

There is a growing interest in the electrical energy storage system, due to the high penetration of the energy produced by renewable sources, the possibility of leveling the absorption peak of the electric network (peak shaving) and the advantage of separating the production phase from the exertion phase (time shift). Compressed air energy storage systems (CAES) are one of the most promising technologies of this field, because they are characterized by a high reliability, low environmental impact and a remarkable energy density. The main disadvantage of big systems is that they depend on geological formations which are necessary to the storage. The micro-CAES system, with a rigid storage vessel, guarantees a high portability of the system and a higher adaptability even with distributed or stand-alone energy productions. This article carries out a thermodynamical and energy analysis of the micro-CAES system, a result of the mathematical model created in a Matlab/Simulink® environment. New ideas will be discussed, as the one concerning the quasi-isothermal compression/expansion, through the exertion of a biphasic mixture, that will increase the total system efficiency and enable a combined production of electric, thermal and refrigeration energies. This is something promising for the development of an experimental devic

Does size matter? Effects of small vs. large pitch small-sided game training on speed and endurance in collegiate soccer players

The aim of this study was to compare the training effect of small-sided games (SSGs) played using large (SSG-L) and small (SSG-S) area per player (ApP) on speed and endurance in college soccer players. Twenty male NCAA division 1 soccer players were randomly assigned to 2 experimental training groups: SSG-L (n = 10), or SSG-S (n = 10). During the 4-week intervention, both groups performed 3 sets of 4-8 minutes of 5 vs 5 SSGs using either a large (300m2; SSG-L) or small (75m2; SSG-S) ApP. Pre- and post-training, players completed linear sprint (20- and 40-m sprint), repeated sprint, and aerobic endurance tests. Following the intervention, both groups exhibited improvements in 20-m, 40-m, and maximum sprinting speed (all p 0.05, g = 0.04 –0.29). No differences or interaction effects in repeat-sprint ability were found for either group (p > 0.05). A decline in maximal aerobic speed occurred in SSG-S (p = 0.010, g = 0.60) whilst no change was reported for SSG-L. Following the intervention, anaerobic speed reserve was lower for SSG-L versus SSG-S (p = 0.013; g = -0.23). No further between-group differences were reported at either time-point. These results suggest that SSGs played with small ApP may not be adequate to maintain aerobic fitness

Limits of Copyright Protection in Contemporary Nigeria: Re-Examining the Relevance of the Nigerian Copyright Act in Today’s Digital and Computer Age

Since the beginning of the 20th century, the world has witnessed astronomical advancement in scientific and technological innovations which have changed the face of modern society, leading many thinkers to term this present civilization ‘the jet age’. This technological advancement has had enormous impact on the world’s legal systems, disrupting traditional modes of protection of intellectual property, and has left the law completely in a state of flux, due to the ever changing forms of innovations; such as computers including palmtops and hitech phones, satellite and cable receivers/signals, facsimile transmissions and the perpetually growing internet. In Nigeria, the Copyright Act purports to protect intellectual property including digital innovations. Notwithstanding, the country remains the largest piracy destination and market in the world. This article examines the Nigerian Copyright Act with the view of identifying the inadequacies which account for the inability of the Act to accord adequate protection to digital inventions in the country. Attention is particularly paid to the problem of the skeletal nature of the Act with respect to the rights of innovators of digital technology and other shrewd and manifests ambiguities and contradictions contained in it. This article also reveals the technological shortcomings which have made it possible for infringers of digital inventions to assail the technology with impunity, and therefore make it impossible for our Copyright Act to live up to its mandate. Thus, in the fight against piracy and copyright infringements of digital innovations, this article strongly recommends extralegal measures, such as administrative, social, judicial and technological, to tame the tide of an otherwise purely socio-legal problem. If we never do anything which has not been done before, we shall never get anywhere, the law will stand still whilst the rest of the world goes on and that will be bad for both

Effects of early and late-dry season fires on mortality, dispersal and breeding of malimbe Malimbus scutatus in the Southern Guinea savannah

Inappropriate use of fire in the guinea savannah is one of the main processes threatening its biodiversity and despite its importance in shaping savannah, it remains poorly understood how the frequency, seasonality and intensity of the fire interact to influence the activities of bird species. While species adversely affected by fire have been documented, empirical studies that seek to identify the ecological mechanisms that underpin this decline are rare. This paper examined the effects of early- and late-dry season fires and a control on the mortality, dispersal and breeding of malimbe Malimbus scutatus in Ikwe Wildlife Park and also tested whether the early fire area became a refuge after the late fire. None of the fire treatment caused any increase in mortality. Individuals relocated short distances to unburnt habitat following both fires. Some birds use the early fire area after the late fire. Mayfield (1975) method of estimations of daily egg-survival probability showed no difference (P > 0.05) among the treatments, whereas the daily probability of nestling survival was significantly lower in the late fire area. Results suggested that the reproductive output of malimbe was low following latedry season fire, and this is the main mechanism that explains their decline. This study provides support for the idea of using early-dry season prescribed burning to limit the effect of late-dry season fire on malimbe.Keywords: inappropriate use, threatening, biodiversity, seasonality, poorly understood, nestling survival

The pin diode as a microwave modulator

This paper is concerned with a brief theoretical presentation of actual modulating circuits and discussion of their operation and results obtained

Agitacja na rzecz kontroli zasobów w delcie Nigru. Rozumienie zasad dotyczących własności rzeczy na gruncie common law w zakresie zarządzania i kontroli zasobami ropy naftowej w Nigerii

The agitation for resource control in Nigeria’s Niger Delta region has frequently snowballed into violence and militancy. Although the demand for resource control borders on the transfer of ownership and management and control of the processes of exploitation of crude oil found abundantly in the region, the exact parametres of the demand are not defined by the agitators. This paper examined the various variants of resource control demanded by the different groups of agitators in the Niger Delta. It particularly argued that the common law private property ownership principles of Cuius est solum, eius est usque ad coelum et ad inferos, and Quic quid plantatur solo, solo cedit be adopted to transfer ownership of natural resources, including crude oil to the indigenous inhabitants of the oil rich Niger Delta region in line with the principles of true federalism. The paper recommended the restructure of the Nigerian federal system to devolve more powers to the states and repeal of certain existing laws that inhibit the rights of the people to own land and natural resources beneath those lands, which belong to them, their ancestors and children yet unborn.Agitacja na rzecz kontroli zasobów w regionie delty Nigru w Nigerii często przeradza się w przemoc i wojnę. Chociaż postulat kontroli zasobów łączy się z kwestiami przeniesienia własności oraz zarządzania i kontroli procesów wydobycia ropy naftowej występującej w dużych ilościach w regionie, dokładne parametry tych żądań nie zostały określone przez agitatorów. W niniejszym artykule analizie poddano różne warianty kontroli zasobów, której domagają się różne grupy agitatorów w delcie Nigru. W szczególności podkreślono, że zasady dotyczące własności prywatnej, wynikające z common law: Cuius est solum, eius est usque ad coelum et ad inferos oraz Quiquid plantatur solo, solo cedit, powinny zostać zastosowane do przenoszenia własności zasobów naturalnych, w tym ropy naftowej, na rdzennych mieszkańców bogatego w ropę regionu delty Nigru, zgodnie z zasadami prawdziwego federalizmu. Autorzy zalecają restrukturyzację nigeryjskiego systemu federalnego w kierunku przekazania większych uprawnień stanom i uchylenia niektórych istniejących praw, które ograniczają prawa ludzi do własności ziemi i zasobów naturalnych znajdujących się pod powierzchnią gruntów należących do nich, ich przodków i jeszcze nienarodzonych dzieci