6,886 research outputs found
Inflation in Supersymmetric SU(5)
We analyze the adjoint field inflation in supersymmetric (SUSY) SU(5) model.
In minimal SUSY SU(5) hybrid inflation monopoles are produced at the end of
inflation. We therefore explore the non-minimal model of inflation based on
SUSY SU(5), like shifted hybrid, which provides a natural solution for the
monopole problem. We find that the supergravity corrections with non-minimal
Kahler potential are crucial to realize the central value of the scalar
spectral index n_s ~ 0.96 consistent with the seven year WMAP data. The tensor
to scalar ratio r is quite small, taking on values r < 10^{-5}. Due to
R-symmetry massless SU(3) octet and SU(2) triplet Higgs bosons are present and
could spoil for gauge coupling unification. To keep gauge coupling unification
intact, light vector-like particles are added which are expected to be observed
at LHC.Comment: 16 page
New Lie group of transformation for the non-Newtonian fluid flow narrating differential equations
In this endeavour, a new Lie point of transformation for the fluid flow narrating differential equations are proposed. For this purpose a non-Newtonian fluid named tangent hyperbolic fluid is considered towards the flat surface in a magnetized flow field. In addition, equation of concentration admits the role of chemically reactive species. A mathematical model in terms of the coupled PDE’s is constructed. Lie group of analysis is implemented to yield the new Lie point of transformation for tangent hyperbolic fluid flow narrating differential equations when the heat and mass transfer individualities are considered. The resultant system of PDE’s is reduced into system of ODE’s via obtained set of transformation. The self-coded computational scheme is accomplished and the outcomes are reported by way of graphs. It is noticed that tangent hyperbolic fluid velocity, temperature and concentration is decreasing function of magnetic field parameter, Prandtl number and chemical reaction parameter respectively
The Effects of Two Teachers’ Instructional Methods on Students’ Learning Outcomes in Chemistry in Selected Senior Secondary School in Kaduna Metropolis, Nigeria
The study investigated the effect of teachers’ instructional methods on students learning outcomes in selected senior secondary school in Kaduna, Nigeria Two instructional methods (Demonstration and Lecture) were used on target population of one thousand nine hundred and eleven (1,911) senior secondary (S.S. II) Science Students. The sample consist of 100 Students randomly drawn from two co-educational senior secondary schools within Kaduna North LGA. The students were divided in to two groups: The experimental group and the control group of 50 students each based on a categorization test to ascertain the equivalence of the group. The pretest-posttest quasi-experimental control group design was adapted. The students in the experimental group were exposed to Demonstration Method, while those in the Control group were exposed to the lecture instructional strategy for a period of three weeks. The instrument developed and validated for data collection was Chemical Bonding Performance Test (CBPT). Four research questions were stated and four null hypotheses were tested. The data collected were analyzed using mean, standard deviation, t-test and ANOVA at 0.05 level of significance. The major findings from the study shows that there is significant difference in learning outcome on students exposed to demonstration and lecture strategies used to teach chemistry (tcal = 0.774 >tcrit = 0.443 and Fcal = 0.771 > Fcrit = 0.710 at P<0.05) and there is no significant difference in the academic performance of both male and female students exposed to demonstration instruction in teaching chemistry (tcal = 0.177 < tcrit = 0.861 and Fcal = 0.728 < Fcrit = 0.781 at P<0.05) . Findings from present study suggest that Chemistry teachers should incorporate demonstration method for teaching at senior secondary school level so as to enhance academic performance and also Curriculum planners should recommend and ensure demonstration method is used for teaching chemistry at senior secondary school among others. Keywords: Chemistry, learning outcome, gender, demonstration and lecture instructional strategie
Regional travel-time residual studies and station correction from 1-D velocity models for some stations around Peninsular Malaysia and Singapore
We have investigated the average P-wave travel-time residuals for some stations around Southern Thailand, Peninsular Malaysia and Singapore at regional distances. Six years (January, 2010–December, 2015) record of events from central and northern Sumatra was obtained from the digital seismic archives of Integrated Research Institute for Seismology (IRIS). The criteria used for the data selection are designed to be above the magnitude of mb 4.5, depth less than 200 km and an epicentral distance shorter than 1000 km. Within this window a total number of 152 earthquakes were obtained. Furthermore, data were filtered based on the clarity of the seismic phases that are manually picked. A total of 1088 P-wave arrivals and 962 S-wave arrivals were hand-picked from 10 seismic stations around the Peninsula. Three stations IPM, KUM, and KOM from Peninsular Malaysia, four stations BTDF, NTU, BESC and KAPK from Singapore and three stations SURA, SRIT and SKLT located in the southern part of Thailand are used. Station NTU was chosen as the Ref. station because it recorded the large number of events. Travel-times were calculated using three 1-D models (Preliminary Ref. Earth Model PREM (Dziewonski and Anderson, 1981, IASP91, and Lienert et al., 1986) and an adopted two-point ray tracing algorithm. For the three models, we corroborate our calculated travel-times with the results from the use of TAUP travel-time calculation software. Relative to station NTU, our results show that the average P wave travel-time residual for PREM model ranges from −0.16 to 0.45 s for BESC and IPM respectively. For IASP91 model, the average residual ranges from −0.25 to 0.24 s for SRIT and SKLT respectively, and ranges from −0.22 to 0.30 s for KAPK and IPM respectively for Lienert et al. (1986) model. Generally, most stations have slightly positive residuals relative to station NTU. These corrections reflect the difference between actual and estimated model velocities along ray paths to stations and can compensate for heterogeneous velocity structure near individual stations. The computed average travel-time residuals can reduce errors attributable to station correction in the inversion of hypocentral parameters around the Peninsula. Due to the heterogeneity occasioned by the numerous fault systems, a better 1-D velocity model for the Peninsula is desired for more reliable hypocentral inversion and other seismic investigations
Adiabatic passage and ensemble control of quantum systems
This paper considers population transfer between eigenstates of a finite
quantum ladder controlled by a classical electric field. Using an appropriate
change of variables, we show that this setting can be set in the framework of
adiabatic passage, which is known to facilitate ensemble control of quantum
systems. Building on this insight, we present a mathematical proof of
robustness for a control protocol -- chirped pulse -- practiced by
experimentalists to drive an ensemble of quantum systems from the ground state
to the most excited state. We then propose new adiabatic control protocols
using a single chirped and amplitude shaped pulse, to robustly perform any
permutation of eigenstate populations, on an ensemble of systems with badly
known coupling strengths. Such adiabatic control protocols are illustrated by
simulations achieving all 24 permutations for a 4-level ladder
Evaluation Study of Boundary and Depth of the Soil Structure for Geotechnical Site Investigation using MASW
This study reviews the correlation between the experimental Rayleigh dispersion curve and the Vp & Vs ground model versus depth. Six samples of stations A , B , C , D , E and F were used in the experiment.The geophone spacing used was set 1 m and total length of each line was 23 m. The result shows positive significance (best fit) of R2 that ranges from 0.80 to 0.90. The fk (frequency-wave number method) dispersion curves analysis confirmed that the soil structure investigated is divided into three zones: (1) Unsaturated soil zone (clay soil), in which the layer is dominated by soil with typically alluvial clayey silt and sand. The Vp ranges from 240 m/s to 255 m/s at a depth of 2 to 8 m. (2) The intermediate zone (stiff soil), in which the layer is dominated by sand, silt, clayey sand, sandy clay and clay of low plasticity. This structure is interpreted as partially saturated soil zone, the soil is typically very dense. It contains soft rock typically fill with cobble, sand, slight gravel and highly weathered at depth of 18 to 30 m with Vp of 255 to 300 m/s. (3) Saturated soil zone at a depth of 8 to 18 m with Vp of 300 to 390 m/s. There is a very good agreement between wave-number (k) and phase velocity (Vw) produced. Both the two parameters shows similar pattern in the topsoil and subsurface layer, which constitute boundary field of soil structure. Moreover, relationship between phase velocity versus wave-length shows best fit of model from inversion with measured value (observed) in implementation of the boundary and depth of each layer
Increasing Performance through Assessed Training (A Human Recourse Management Strategy)
This research finds out the way of increasing employee’s performance through training. There are many organizations which give their workers training but do not get any enhancement in their performance. Performances of a worker are directly correlated with his/her capabilities and know how to do the job. This study develops a strategy for improving the capabilities of workers which leads to increase their performance. The research proposes that just after an organization want to increase the performance of its workers, it must find out the area where they have weaknesses. After finding out the weaknesses, organizations have to assess how that weakness should be made solved. In the third stage they have to give specific training their weaknesses. This will enhance the capabilities of workers and their performance will be increased. Keywords: Weakness, Weakness needs Assessments, Training and Performanc
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