186 research outputs found
Assessment of Students Performances in Biology: Implication for Measurements and Evaluation of Learning
Scienceeducation is believed to be a vital tool for individual and societal development at large. The persistent low levels of students' achievement in sciences at the various public examinations in Nigeria have continued to draw the attention of major stakeholders in education. This study examined academic achievement of Senior Secondary School students in biology and gender difference in students' achievement was examined. Ex-post facto design of descriptive research was adopted for the study. A proforma was used to collect data from a sample of two hundred (200) students, selected using stratified random sampling procedure from the Science secondary schools in Kano state Nigeria. The data collected were the students' performances in biology achievement tests. The data were analysed using descriptive statistics and independent-sample t-test. Overall results showed that the test internal consistency reliability is low and unsatisfactory; the students performed below average (M=47.02, SD=16.493 (47%). Similarly, gender difference exists in biology performance with another significant difference between performance of urban and rural school students. The study concludes that, biology test used in Kano state qualifying examinations to assess students potential ability in biology is not a reliable measurement tool and that, academic performance of students in biology is unsatisfactory and evidence of differential performance between gender and schools locations. The implication for measurements and evaluation of learning as well as recommendations has been discussed
Web-based Billing and Collection System for a Municipal Water and Services Unit
Web-Based Billing and Collection System for a Municipal Water and Services Unit is a system that sought to address the problem of a municipal water unit. Using the technology, meter reading will be paperless. It can be accessible through the Internet; end-users and water consumers/customers could connect and performtransactions enabling them to become efficient on their daily tasks whether in the office or at home. The head of the unit can make overall viewing of the status of daily transactions and can be viewed using desktop, laptop computers and android mobile devices connected to the internet. The water consumers/customers mayreceive email and short messaging system showing their current water consumption and water bill. Added/unique features such as graphical chart showing regular water consumptions on the end-users and consumers/customers dashboard as well as on their billing statements are provided. On the level of satisfaction of the respondents on the features of the proposed billing and collection system; result show that efficiencyearned the highest weighted mean (4.43) interpreted as âsatisfiedâ. Functionality posed weighted arithmetic mean (4.33) verbally interpreted as âsatisfiedâ. Portability and reliability followed next. On the level of acceptance of the proposed billing and collection system; respondentsâ acceptance according to consumer accounts updating gauged at 4.35 weighted arithmetic mean with verbal interpretation of âacceptableâ.Auto-reminding the consumers for bills due for payment posed a 4.37 weighted arithmetic mean and was also âacceptableâ. According to billing statement printing and free format report generation, respondents recorded 4.45 weighted arithmetic mean and interpreted as âacceptableâ.
Keywords: billing system, ewater, municipal water, web-based billing, collection system
Spin-torque resonance due to diffusive dynamics at a surface of topological insulator
We investigate spin-orbit torques on magnetization in an insulating
ferromagnetic (FM) layer that is brought into a close proximity to a
topological insulator (TI). In addition to the well-known field-like spin-orbit
torque, we identify an anisotropic anti-damping-like spin-orbit torque that
originates in a diffusive motion of conduction electrons. This diffusive torque
is vanishing in the limit of zero momentum (i. e. for spatially homogeneous
electric field or current), but may, nevertheless, have a strong effect on
spin-torque resonance at finite frequency provided external field is neither
parallel nor perpendicular to the TI surface. The required electric field
configuration can be created by a grated top gate.Comment: 10 page main text, 3 figure
Animal Identification and Records Monitoring Tool using RFID (AIRMTR)
This study was conducted to design, develop and initially implement the Animal Identification and Records Monitoring Tool using RFID. Specifically, it identified the problems encountered in conducting Manual Tagging for Animal Clinic; the appropriate features of the tool that can be developed to address the problems encountered, and the respondentsâ level of acceptance of the user toward the developed tool in termsof functionality, reliability, usability, and performance. The research used the qualitative-quantitative research method that utilized a researcher-made questionnaire and interview questions. The respondents of the studywere one (1) Animal Care Specialist representative, one (1) Pretty Paws representative, five (5) veterinarian representatives and eighty (80) pet owners from different places. The problems encountered in conducting tagging for animal clinic were traditional animal tag may cause death to some animals; animal diseases and injuries by animal tagging; duplication and confusion in using animal tagging; and difficulty in maintainingrecords of vaccination, medication health check-ups using animal tagging. The appropriate features of the tool that can be developed to address the problems encountered were: RFID can make the process of animal tagging faster and easier; and online scheduling and identification of pets in pet clinics are more convenient to use for both pet owners and veterinarians rather than the manual process. The respondentsâ ratings for Animal Identification and Record Monitoring Tool using RFID were highly acceptable in terms of functionality (4.62); reliability (4.52); usability (4.68); and performance (4.59). The government agencies may suggest that animals should be tagged using the developed system for monitoring purposes. Further research on Internet controlleddevices may be conducted other than stand-alone offline software programs. This study may also be developed considering the following features: UHF as a tracking device for animals; individual registered users to make page where the client can edit, rate and price; displaying hex value using LCD; access to the shopâs system to bevalidated; contraction number of the project with logo and clinicâs validation.
Keywords: Animal Identification, Manual Tagging, RFI
From <i>extractive</i> to <i>transformative</i> industries:paths for linkages and diversification for resource-driven development
Dynamic simulation of the THAI heavy oil recovery process
Toe-to-Heel Air Injection (THAI) is a variant of conventional In-Situ Combustion (ISC) that uses a horizontal production well to recover mobilised partially upgraded heavy oil. It has a number of advantages over other heavy oil recovery techniques such as high recovery potential. However, existing models are unable to predict the effect of the most important operational parameters, such as fuel availability and produced oxygen concentration, which will give rise to unsafe designs. Therefore, we have developed a new model that accurately predicts dynamic conditions in the reservoir and also is easily scalable to investigate different field scenarios. The model used a three component direct conversion cracking kinetics scheme, which does not depend on the stoichiometry of the products and, thus, reduces the extent of uncertainty in the simulation results as the number of unknowns is reduced. The oil production rate and cumulative oil produced were well predicted, with the latter deviating from the experimental value by only 4%. The improved ability of the model to emulate real process dynamics meant it also accurately predicted when the oxygen was first produced, thereby enabling a more accurate assessment to be made of when it would be safe to shut-in the process, prior to oxygen breakthrough occurring. The increasing trend in produced oxygen concentration following a step change in the injected oxygen rate by 33 % was closely replicated by the model. The new simulations have now elucidated the mechanism of oxygen production during the later stages of the experiment. The model has allowed limits to be placed on the air injection rates that ensure stability of operation. Unlike previous models, the new simulations have provided better quantitative prediction of fuel laydown, which is a key phenomenon that determines whether, or not, successful operation of the THAI process can be achieved. The new model has also shown that, for completely stable operation, the combustion zone must be restricted to the upper portion of the sand pack, which can be achieved by using higher producer back pressure
Selection Rules for One- and Two-Photon Absorption by Excitons in Carbon Nanotubes
Recent optical absorption/emission experiments showed that the lower energy
optical transitions in carbon nanotubes are excitonic in nature, as predicted
by theory. These experiments were based on the symmetry aspects of free
electron-hole states and bound excitonic states. The present work shows,
however, that group theory does not predict the selection rules needed to
explain the two photon experiments. We obtain the symmetries and selection
rules for the optical transitions of excitons in single-wall carbon nanotubes
within the approach of the group of the wavevector, thus providing important
information for the interpretation of theoretical and experimental optical
spectra of these materials.Comment: 4 pages, 1 figure, 1 tabl
Muon Collider
Both e+e- and {\mu}+{\mu}- colliders have been proposed as possible
candidates for a lepton collider to complement and extend the reach of the
Large Hadron Collider (LHC) at CERN. The physics program that could be pursued
by a new lepton collider (e+e- or {\mu}+{\mu}-) with sufficient luminosity
would include understanding the mechanism behind mass generation and
electroweak symmetry breaking; searching for, and possibly discovering,
supersymmetric particles; and hunting for signs of extra spacetime dimensions
and quantum gravity. However, the appropriate energy reach for such a collider
is currently unknown, and will only be determined following initial physics
results at the LHC. It is entirely possible that such results will indicate
that a lepton collider with a collision energy well in excess of 1 TeV will be
required to illuminate the physics uncovered at LHC. Such a requirement would
require consideration of muons as the lepton of choice for such a collider.Comment: v.2., 6 pp. To appear in the 2nd edition of the book Elementary
Particles, Landolt-Boernstein Series published by Springer. arXiv admin note:
text overlap with arXiv:physics/9901022 by other autho
Optical-phonon resonances with saddle-point excitons in twisted-bilayer graphene
Twisted-bilayer graphene (tBLG) exhibits van Hove singularities in the
density of states that can be tuned by changing the twisting angle . A
-defined tBLG has been produced and characterized with optical
reflectivity and resonance Raman scattering. The -engineered optical
response is shown to be consistent with persistent saddle-point excitons.
Separate resonances with Stokes and anti-Stokes Raman scattering components can
be achieved due to the sharpness of the two-dimensional saddle-point excitons,
similar to what has been previously observed for one-dimensional carbon
nanotubes. The excitation power dependence for the Stokes and anti-Stokes
emissions indicate that the two processes are correlated and that they share
the same phonon.Comment: 5 pages, 6 figure
Status of Muon Collider Research and Development and Future Plans
The status of the research on muon colliders is discussed and plans are
outlined for future theoretical and experimental studies. Besides continued
work on the parameters of a 3-4 and 0.5 TeV center-of-mass (CoM) energy
collider, many studies are now concentrating on a machine near 0.1 TeV (CoM)
that could be a factory for the s-channel production of Higgs particles. We
discuss the research on the various components in such muon colliders, starting
from the proton accelerator needed to generate pions from a heavy-Z target and
proceeding through the phase rotation and decay ()
channel, muon cooling, acceleration, storage in a collider ring and the
collider detector. We also present theoretical and experimental R & D plans for
the next several years that should lead to a better understanding of the design
and feasibility issues for all of the components. This report is an update of
the progress on the R & D since the Feasibility Study of Muon Colliders
presented at the Snowmass'96 Workshop [R. B. Palmer, A. Sessler and A.
Tollestrup, Proceedings of the 1996 DPF/DPB Summer Study on High-Energy Physics
(Stanford Linear Accelerator Center, Menlo Park, CA, 1997)].Comment: 95 pages, 75 figures. Submitted to Physical Review Special Topics,
Accelerators and Beam
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