Dissipation in Compressible MHD Turbulence

We report results of a three dimensional, high resolution (up to 512^3) numerical investigation of supersonic compressible magnetohydrodynamic turbulence. We consider both forced and decaying turbulence. The model parameters are appropriate to conditions found in Galactic molecular clouds. We find that the dissipation time of turbulence is of order the flow crossing time or smaller, even in the presence of strong magnetic fields. About half the dissipation occurs in shocks. Weak magnetic fields are amplified and tangled by the turbulence, while strong fields remain well ordered.Comment: 5 pages, 3 Postscript figures, LaTeX, accepted by Ap.J.Let

Design and Implementation of a Microprocessor Based Temperature Controller With Real Time Display

The objective of the project was to automate and control temperature for a server room. The system is allowed entry of a desired room temperature within a prescribed range and to exhibit overshoot and steady-state temperature error of less than 1 degree displaying the value in real time. The details of the design developed, based on a PIC18F452 microcontroller are described. Time, cost and energy are saved by delivering power efficiently using this system. It can be applied in industries, auditoriums, green house buildings, server rooms and nuclear facilities. It is shown that the solution requires broad knowledge drawn from several engineering disciplines including electrical, mechanical, and control systems engineering. Keywords: Temperature, Sensor, Display, Control, Microcontroller, Real Time

The Influence of Aid and Income on Persistence at a Small Private College

In the 1990s, many private institutions gave up the practice of making need-blind admission decisions and stopped aiding students to the full extent of their need

Anti-inflammatory activity and accelerated stability studies of crude extract syrup of Cannabis sativa

Purpose: To formulate Cannabis sativa-based syrup and investigate its anti-inflammatory potential and the stability of the formulation under stress conditions.Methods: The syrup was prepared using different combinations of crude C. sativa resin, propylene glycol, aspartame, sucrose, sodium metabisulphite (SMBs) and ethylenediaminetetraacetic acid (EDTA). The stability of the formulations was determined under accelerated temperature conditions. The anti-inflammatory activity of the resin and different formulations were evaluated by the egg albumin induced paw edema model in rats. Biochemical assay was determined by Reitman and Frankel colorimetric assay method while hematological assay was evaluated by standard protocols.Results: EDTA-containing syrup (CE) was the most stable with estimated shelf-life of 2204 days (K25ºC, 4.78 x 10-5/day). Higher propylene glycol levels significantly improved anti-inflammatory activity compared to those containing a lower amount. All the formulations showed anti-inflammatory activity higher than the crude resin with a dose-dependent inhibition of paw edema compared with the control. There was no significant difference (p < 0.05) between the serum glutamate-oxaloacetate transaminase (SGOT, 13.821 ± 0.190 - 16.008 ± 1.012), serum glutamate-pyruvate transaminase (SGPT, 19.241 ± 1.027 - 22.901 ± 1.093) and urea (9.812 ± 0.252 - 10.054 ± 0.252) levels of the treated and 16.856 ± 1.053, 24.960 ± 0.101 and 10.654 ± 0.925 units/L of the control animals respectively. With the exception of eosinophil that disappeared from the blood in the third week, all the hematological parameters showed a gradual increase in lymphocytes, neutrophils, monocytes, packed cell volume (PCV), white and red blood cell counts in the third week compared to control.Conclusion: Formulation of C. sativa as syrup using efficient carriers improves the pharmacological activity of the crude extract. SMBs and EDTA significantly enhance the stability of the syrup with no observable biochemical and hematological changes in treated animalsKeywords: Cannabis sativa, Syrup, Anti-inflammatory, Stability, Hematologica

The Allocation of a Shared Resource Within an Organization

Many resources such as supercomputers, legal advisors, and university classrooms are shared by many members of an organization. When the supply of shared resources is limited, conflict usually results between contending demanders. If these conflicts can be adequately resolved, then value is created for the organization. In this paper we use the methodology of applied mechanism design to examine alternative processes for the resolution of such conflicts for a particular class of scheduling problems. We construct a laboratory environment, within which we evaluate the outcomes of various allocation mechanisms. In particular, we are able to measure efficiency, the value attained by the resulting allocations as a percentage of the maximum possible value. Our choice of environment and parameters is guided by a specific application, the allocation of time on NASA's Deep Space Network, but the results also provide insights relevant to other scheduling and allocation applications. We find (1) experienced user committees using decision support algorithms produce reasonably efficient allocations in lower conflict situations but perform badly when there is a high level of conflict between demanders, (2) there is a mechanism, called the Adaptive User Selection Mechanism (AUSM) which charges users for time, which yields high efficiencies in high conflict situations but because of the prices paid, the net surplus available to the users is less than that resulting from the inefficient user committee (a reason why users may not appreciate "market solutions" to organization problems) and (3) there is a modification of AUSM in which tokens, or internal money, replaces real money, which results in highly efficient allocations without extracting any of the users' surplus. Although the distribution of surplus is still an issue, the significant increase in efficiency provides users with a strong incentive to replace inefficient user committees with the more efficient AUSM

Simulation of phosphorus implantation into silicon with a single-parameter electronic stopping power model

We simulate dopant profiles for phosphorus implantation into silicon using a new model for electronic stopping power. In this model, the electronic stopping power is factorized into a globally averaged effective charge Z1*, and a local charge density dependent electronic stopping power for a proton. There is only a single adjustable parameter in the model, namely the one electron radius rs0 which controls Z1*. By fine tuning this parameter, we obtain excellent agreement between simulated dopant profiles and the SIMS data over a wide range of energies for the channeling case. Our work provides a further example of implant species, in addition to boron and arsenic, to verify the validity of the electronic stopping power model and to illustrate its generality for studies of physical processes involving electronic stopping.Comment: 11 pages, 7 figures. See http://bifrost.lanl.gov/~reed

Transformative Potentials of E-governance: The intrinsic role of Information and Communication Technology in Reinvigorating Public Service Delivery in Nigeria

Proffering solutions to developmental issues such as poverty, unemployment, high costs of governance and poor service delivery among others require changes to government processes through the use of information and communication technologies (ICT). This paper examines the transformative potentials of e- governance vis-à-vis the intrinsic role of information and communication technology (ICT) in reinvigorating public service delivery in Nigeria. To accomplish the objective of this paper, systematic review of literature on these issues was presented and discussed. The paper deliberated that e-governance is more than just the visibility of government website on the internet. In other words, e-governance relates to restructuring the state’s administrative procedure and in ensuring that the government is more transparent, and service-oriented. Remarkably, public service delivery in Nigeria has been adjudged to be poor, and fall short of expectations of citizen. As a result it has become a theme of mockery because of its rigidity and after many years of effort in implementing reforms in public service, it costs too much to delivers very little, and the level of achievement is not sufficiently responsive and accountable. The paper concludes that public services reinforce the social contract between states and citizens and, as such, serve as indicator of wellbeing of the society. Therefore, for Nigeria to make progress; there is need to strengthening public service delivery via ICT. The paper recommends that effort should be intensified to ensure that e-governance bridge the digital divide through training and by adapting technologies that is accessible to all user groups

Molecular epidemiology of human rhinovirus infections in Kilifi, coastal Kenya

This study reports pediatric surveillance over 3 years for human rhinovirus (HRV) at the District Hospital of Kilifi, coastal Kenya. Nasopharyngeal samples were collected from children presenting at outpatient clinic with no signs of acute respiratory infection, or with signs of upper respiratory tract infection, and from children admitted to the hospital with lower respiratory tract infection. Samples were screened by real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and classified further to species by nucleotide sequencing of the VP4/VP2 junction. Of 441 HRV positives by real-time RT-PCR, 332 were classified to species, with 47% (155) being HRV-A, 5% (18) HRV-B, and 48% (159) HRV-C. There was no clear seasonal pattern of occurrence for any species. The species were present in similar proportions in the inpatient and outpatient sample sets, and no significant association between species distribution and the severity of lower respiratory tract infection in the inpatients could be determined. HRV sequence analysis revealed multiple but separate clusters in circulation particularly for HRV-A and HRV-C. Most HRV-C clusters were distinct from reference sequences downloaded from GenBank. In contrast, most HRV-A and HRV-B sequences clustered with either known serotypes or strains from elsewhere within Africa and other regions of the world. This first molecular epidemiological study of HRV in the region defines species distribution in accord with reports from elsewhere in the world, shows considerable strain diversity and does not identify an association between any species and disease severity

Effects of Variety, Spacing and Nitrogen Application on Chickpea (Cicer arietinum) Growth and Yield in Embu County, Kenya

Chickpea is a pulse crop that is rich in proteins and helps in fulfilling the requirement of protein for vegetarian people thus yield maximization needed. This study aimed to determine the effects of spacing, nitrogen rates, and their interactive effects on the growth and productivity of the selected chickpea varieties. Field experiments were conducted at Mwea, Kenya between 2017 and 2018 involving four varieties (Saina K, Mwanza 2, Chaina I and Chaina III) at a spacing of 50x10cm, 50x20cm, and 50x30cm, and starter nitrogen-fertilizer application rates 0kg, 30kg, 60kg, and 90kg ha-1. A split-split plot design arranged in a 4x3x4 layout was used in the current study. Data related to plant height, biomass, grain yield, and harvest index were collected and subjected to statistical analysis by GLM in SAS 9.4 computer software. Variations occurred in measured traits like the height of crops (34.81-38.00cm), biomass yield (3.31 - 8.08t ha-1), seed yield (0.14 to 1.9t ha-1), and percent harvest index (5 - 45%) was reported. Mwanza 2 expressed the highest plant height, biomass, and grain yield. The highest plant biomass was obtained under 50x10cm spacing, while the highest grain yield weight was reported under 50x30cm spacing x 60kg N ha-1. From the results of the study, it can be concluded that the highest enhanced growth and productivity of chickpea were realized at interactions of Mwanza 2x50x10cmx90kg ha-1 nitrogen rate in the study area

Addendum: "The Dynamics of M15: Observations of the Velocity Dispersion Profile and Fokker-Planck Models" (ApJ, 481, 267 [1997])

It has recently come to our attention that there are axis scale errors in three of the figures of Dull et al. (1997, hereafter D97). D97 presented Fokker-Planck models for the collapsed-core globular cluster M15 that include a dense, centrally concentrated population of neutron stars and massive white dwarfs, but do not include a central black hole. In this Addendum, we present corrected versions of Figures 9, 10, and 12, and an expanded version of Figure 6. This latter figure, which shows the full run of the velocity dispersion profile, indicates that the D97 model predictions are in good agreement with the moderately rising HST-STIS velocity dispersion profile for M15 reported by Gerssen et al. (2002, astro-ph/0209315). Thus, a central black hole is not required to fit the new STIS velocity measurements, provided that there is a sufficient population of neutron stars and massive white dwarfs. This conclusion is consistent with the findings of Gerssen et al. (2002, astro-ph/0210158), based on a reapplication of their Jeans equation analysis using the corrected mass-to-light profile (Figure 12) for the D97 models.Comment: 4 pages, 4 figures, submitted to Ap