944 research outputs found
Proceedings of the African Diaspora Conference on Sustainable Development
The authors urge the Western donor organizations to facilitate and support the take up of such more sustainable models
Block Analysis for the Calculation of Dynamic and Static Length Scales in Glass-Forming Liquids
We present {\it block analysis}, an efficient method to perform finite-size
scaling for obtaining the length scale of dynamic heterogeneity and the
point-to-set length scale for generic glass-forming liquids. This method
involves considering blocks of varying sizes embedded in a system of a fixed
(large) size. The length scale associated with dynamic heterogeneity is
obtained from a finite-size scaling analysis of the dependence of the
four-point dynamic susceptibility on the block size. The block size dependence
of the variance of the -relaxation time yields the static point-to-set
length scale. The values of the obtained length scales agree quantitatively
with those obtained from other conventional methods. This method provides an
efficient experimental tool for studying the growth of length scales in systems
such as colloidal glasses for which performing finite-size scaling by carrying
out experiments for varying system sizes may not be feasible.Comment: 5 pages, 3 figure
W-Band GaAs HEMT MMIC Subharmonically Pumped Diode Mixers with 20 GHz IF Bandwidth
Two subharmonically pumped (SHP) diode mixers are designed for wideband W-band RF frequencies, fixed LO frequency operation. These mixers are fabricated on a 4-mil substrate using 0.1- µµµµm GaAs MMIC process. Both simulation and test results show that the mixers are with 12.25 and 11.75 dB average conversion losses, respectively. Both mixers have IF bandwidth wider than 20 GHz. The conversion loss flatness of the symmetric circuit is within ±1.25 dB. To our knowledge, these are the state-of-the-art result on low-conversion-loss wideband MMIC SHP diode mixers
Glass Transition in Supercooled Liquids with Medium Range Crystalline Order
The origins of rapid dynamical slow down in glass forming liquids in the
growth of static length scales, possibly associated with identifiable
structural ordering, is a much debated issue. Growth of medium range
crystalline order (MRCO) has been observed in various model systems to be
associated with glassy behaviour. Such observations raise the question about
the eventual state reached by a glass former, if allowed to relax for
sufficiently long times. Is a slowly growing crystalline order responsible for
slow dynamics? Are the molecular mechanisms for glass transition in liquids
with and without MRCO the same? If yes, glass formers with MRCO provide a
paradigm for understanding glassy behaviour generically. If not, systems with
MRCO form a new class of glass forming materials whose molecular mechanism for
slow dynamics may be easier to understand in terms of growing crystalline
order, and should be approached in that manner, even while they will not
provide generic insights. In this study we perform extensive molecular dynamics
simulations of a number of glass forming liquids in two dimensions and show
that the static and dynamic properties of glasses with MRCO are different from
other glass forming liquids with no predominant local order. We also resolve an
important issue regarding the so-called Point-to-set method for determining
static length scales, and demonstrate it to be a robust, order agnostic, method
for determining static correlation lengths in glass formers
GIS-based locational analysis of petrol filling stations in Kaduna Metropolis
Location of environmental sensitive commercial and service activities in densely populated urban areas are guided by planning principles and standards, expressed in either structure plans or land use development plans. There has been an upsurge of filling stations within Kaduna metropolis thereby raising the questions about their certified locations. This study analysed the location of filling stations in Kaduna Metropolis against the physical planning standards set by Department of Petroleum Resource (DPR) and Kaduna Urban Planning and Development Agency (KASUPDA). Names and addresses of the filling stations were obtained from the Department of Petroleum Resource (DPR) Kaduna. Global Positioning System (GPS) Garmin 78s map was used to capture the locations of the filling stations. The findings revealed that there are 228 filling stations located along the 26 roads in the study area, of which 74% are owned by independent marketers, 18% owned by Major Marketers and 8% owned by the NNPC. There is significant correlation between the number of filling stations and the road hierarchy. However, 86% of the filling stations did not meet the minimum distance of 100 meter from the health care facilities. 84% did not meet the criteria of 400 meter minimum distance to other stations where located on same road side. The research recommends that the regulatory agencies should take appropriate measures to ensure that filling stations operators comply with the standards.Keywords: GIS, Analysis, Petrol, Filling Station, DPR, Kaduna metropoli
Cyber Security: Detection of Malicious Insiders for the Financial Benefit of Côte d\u27Ivoire
According to ‘Croissance Afrique’, a local magazine, the annual economic impact of cybercrime in Cote d\u27Ivoire is estimated to be 10 million dollars per year (2022). Furthermore, cybercrime is a costly issue in Cote d’Ivoire and the country is included in the list of countries with poor cyber security. Cybercrime affects not only the country but also has a worldwide impact. Improving cyber security will have a positive economic impact on the country
Geographical information system application in site suitability analysis for hostel development in Ahmadu Bello University, Zaria
This paper investigates the application of GIS in site selection analysis with the aim of selecting the most suitable site for developing a new hostel block within the ABU Samaru campus space. To achieve this, a spot-5 image of ABU Zaria Samaru campus was used to bring out the land use and land cover of the area so as to determine the available and suitable spaces. The study created weight maps for each factor and a digital elevation model was created to determine aspect and slope. This study identified seven vacant sites in ABU Samaru campus, which were ranked based on the suitability factors of; distance to roads, distance to academic areas, the presence of existing hostel facilities, distance from gullies, distance from water bodies and the size of the area. This study recommends the space by the North Gate that extends to just behind quarter 3, the space between drama village and staff school and the space and the space between the school gym and NUGA gate as highly suitable, very suitable and suitable respectively in descending order.Key words: ABU Zaria, GIS, site suitability, site selection, hostel
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