An Examination Of Time Use Patterns Influence On Academic Achievement Among African American And Hispanic Male High School Stude

The purpose of this investigation is to contribute to the body of knowledge in the area of effective time management skills among African American and Hispanic male student athletes and their academic achievement utilizing the Educational Longitudinal Study of 2002 (ELS: 2002) Base year thru the First follow-up database. The researcher has assessed indicators (socioeconomic status, time use patterns, sports participation, and race) within the construct of academic achievement among African American and Hispanic male high school student athletes. Their contribution to the main effects revealed that statistically significant differences exist between the non-sports participant and sports participant groups. After controlling for time spent completing mathematics homework and socioeconomic status, the findings revealed that time spent completing math homework was significantly related to academic achievement for African American and Hispanic male student athletes. Time spent watching television was not significantly related to academic achievement for African American and Hispanic male student athletes. For the variable time spent playing on the computer game, the analysis indicated that the detrimental effect of time spent playing video/computer games was the same for African American and Hispanic male student athletes. Finally, it is noteworthy that effective use of time (i.e., playing video games less) and sports participation positively influences academic achievement of African American and Hispanic males high school student athletes. Strategies were uncovered for possible future research among African American and Hispanic male student athletes to increase academic achievement levels

Energetic and environmental benefits of co-digestion of food waste and cattle slurry: a preliminary assessment

The research evaluated the feasibility of centralised pre-processing and pasteurisation of source-separated domestic food waste followed by transport to farms for anaerobic co-digestion with dairy cattle slurry. Data from long-term experiments on the co-digestion of these two substrates was used to predict gross energy yields; net yields were then derived from full system analysis using an energy modelling tool. The ratio of cattle slurry to food waste in the co-digestion was based on the nutrient requirements of the dairy farm and was modelled using both nitrogen and phosphorous as the limiting factor. The model was run for both medium-size and large farms in which the cattle were housed either all year round or for only 50% of the year. The results showed that the addition of food waste improved energy yields per digester unit volume, with a corresponding increased potential for improving farm income by as much as 50%. Data for dairy farms in the county of Hampshire UK, which has a low density of dairy cattle and a large population, was used as a stringent test case to verify the applicability of the concept. In this particular case the nutrient requirements of the larger farms could be satisfied, and further benefits were gained from the reduction in greenhouse gas emissions avoided through improved manure management and fertiliser imports. The results indicated that this approach offered major advantages in terms of resource conservation and pollution abatement when compared to either centralised anaerobic digestion of food waste or energy recovery from thermal treatmen

The dependence of the hydrogen sorption capacity of single-walled carbon nanotubes on the concentration of catalyst

The adsorption of hydrogen on single-walled carbon nanotubes was measured using micro-gravimetric nitrogen and hydrogen adsorption isotherms at 77 K for gas pressures of up to 1 bar (nitrogen) and 12 bar (hydrogen). Results show that surface area and hydrogen uptake depend on the concentration of the iron catalyst used for making the nanotubes. Langmuir fits to the hydrogen uptake curves clearly show two adsorption energies for each sample which we attribute to the groove site for the higher adsorption energy and to the convex tube surface for the lower energy. We also present calculations of the binding energy of hydrogen on these same sites on SWCNTs and confirm that the groove site has a significantly higher (radius-dependent) binding energy than the surface site, consistent with the experimental values. This suggests that the use of the Langmuir model is appropriate to the adsorption of H2 on activated carbons for the temperature and pressure range investigated and could be used as a rapid way of estimating the average tube radius in the sample

Greater functional aerobic capacity predicts more effective pain modulation in older adults

poster abstractEndogenous pain inhibitory and facilitory function deteriorates with age, potentially placing older adults at greater risk for chronic pain. Prior research shows that self-reported physical activity predicts endogenous pain inhibitory capacity and facilitation of pain on quantitative sensory tests (QST) in healthy adults. Purpose: To investigate whether functional aerobic capacity and lower extremity strength in older adults cross-sectionally predicts pain sensitivity, pain inhibition following isometric exercise, and facilitation of pain during heat pain temporal summation (TS) tests. Methods: 42 subjects (10 male, 32 female, age=67.5±5.1) completed the 6-minute walk test (6MWT), 30-second chair stand test, and several QSTs. QSTs included: 1) Pain ratings (0-100 scale) during the submersion of the hand in a cold water bath (CWB), 2) heat pain threshold tests, 3) the amount of pain reduction following submaximal isometric exercise, and 4) degree of pain facilitation during temporal summation tests conducted at 44, 46, and 48°C. Responses on the QSTs were analyzed using hierarchical linear regression with meters on 6MWT and number of chair stands as final predictors. Results: After controlling for demographic and psychological factors, aerobic capacity on 6MWT significantly predicted CWB pain ratings (R2 change= 22.5%, Beta= -0.491), pain facilitation during TS trials at 44°C (R2 change= 16.7%, Beta= -0.446), and the amount of pain reduction following isometric exercise (R2 change= 20.7%, Beta= 0.393). All other analyses were not significant (P>0.05). Conclusions: Older adults exhibiting greater functional aerobic capacity displayed reduced cold pain sensitivity, reduced pain facilitory function, and increased pain inhibition following exercise. These findings suggest that increased aerobic fitness in older adults may be associated with more effective endogenous modulation of pain. This study was funded by the IUPUI School of PETM Faculty Research Opportunity Grant

Field experiments on solar geoengineering: report of a workshop exploring a representative research portfolio

We summarize a portfolio of possible field experiments on solar radiation management (SRM) and related technologies. The portfolio is intended to support analysis of potential field research related to SRM including discussions about the overall merit and risk of such research as well as mechanisms for governing such research and assessments of observational needs. The proposals were generated with contributions from leading researchers at a workshop held in March 2014 at which the proposals were critically reviewed. The proposed research dealt with three major classes of SRM proposals: marine cloud brightening, stratospheric aerosols and cirrus cloud manipulation. The proposals are summarized here along with an analysis exploring variables such as space and time scale, risk and radiative forcing. Possible gaps, biases and cross-cutting considerations are discussed. Finally, suggestions for plausible next steps in the development of a systematic research programme are presented

The kinetics of steam gasification of South African coals.

Thesis (Ph.D.)-University of Natal, Durban, 1990.The prime objective of a current research project at the University of Natal is to develop a novel autothermal fluidised bed coal gasifier which is capable of efficiently producing synthesis quality gas (rich in hydrogen and carbon monoxide) from discard of duff coal resources using air and steam as the reactant gases. The development of this gasifier was initially motivated to utilise the ever increasing supply of discard coal in South Africa which represents a significant potential source of energy and currently poses severe environmental pollution hazards caused by spontaneous combustion and wind erosion of the discard coal dumps. Recently, however, the gasifier has been considered for the conversion of more general coal resources in an Integrated Coal Gasification Combined Cycle process (IGCC) for the production of electricity. The knowledge of the kinetics of steam gasification of local coal resources is of vital importance to the design of this gasifier. However, no such kinetic data are available of which the author is aware. This thesis presents the following contributions to the overall knowledge of the gasifier (a) The development of a micro reactor to measure the rate of reaction of the steam gasification of coal-char at temperatures of up to l000oC and pressures up to 5 bar absolute; (b) Kinetic studies using the microreactor on the steam gasification of coal-chars derived from Bosjesspruit and Transvaal Navigation coal samples. The following principal results were obtained with Bosjesspruit coal-char : The rate of steam-char gasification is very sensitive to variations in the temperature of reaction in the range 840°C to 920°C. Neither the rate of steam-char gasification nor the product gas composition are affected by the steam partial pressure in the range 1.8 to 4.8 bar absolute; The concentrations of the H2 and CH4 components of the product gas stream rapidly approached their respective equilibrium compositions, whereas the concentrations of CO and CO2 gradually approach their respective equilibrium compositions during gasification at a rate which is typical of the stoichiometry of the Boudouard reaction. The average product gas composition is independent of the temperature of reaction in the range 840°C to 920°C and is approximately 49% H2, 32% CO, 17% CO2 and 2% CH4 on a molar basis; The steam gasification kinetic data are well described by a fundamental Arrhenius-type volumetric reaction model at (c) temperatures of up to 920°C. The value of the activation energy for the reaction is 146 kJ/gmol, which indicates that the gasification kinetics are controlled by the rates of the chemical reactions (ie. C + H2O = CO + H2 and C + CO2 = 2CO) at temperatures up to 920o C; There are no major differences between the kinetics measured for Bosjesspruit coal-char and those reported in the literature for foreign coal-chars. The experimental results obtained for the steam gasification of char derived from Transvaal Navigation coal show that the concentrations of both the Hz and the CH4 in the product gas stream rapidly attain their respective equilibrium values and remain approximately constant throughout gasification, whereas the concentrations of CO and CO2 gradually approach their respective equilibrium values during the course of gasification and almost attain equilibrium concentrations as the conversion of carbon nears completion. The rate of steam gasification of this char is therefore also controlled by the rate of the Boudouard reaction. The mathematical development of a steady-state, one-dimensional compartment model of the gasifier. The model is also presented in the form of a Fortran 77 computer program which is designed to run on a personal computer. The program is capable of simultaneously solving the overall material and energy balances of the gasifier to a tolerance of l% within 15 minutes when using a microprocessor which operates at 10 Mhz. (d) The gasifier simulation program is currently being used in the design of a pilot scale gasifier which is intended to demonstrate the capability of the process on a continous basis of operation. (e) Experimentation on the air-steam gasification of Bosjesspruit coal using a mini-pilot scale gasifier. These experiments have successfully demonstrated the feasibility of the production of a gas stream which is rich in hydrogen and carbon monoxide. The composition of the product gas stream compares well with the predictions of the simulation model of the gasifier

Snowmelt Simulation

The rapid growth in recent years of a variety of demands upon available water resources has lead to an increasing interest in more fundamental approaches to the science of hydrology. Accompanying this growth has been a need for an increased understanding of the snowmelt process. A completely adequate description of the entire physical process of snowmelt under all conditions is not yet available. The complex interrelated and variable nature of the snowmelt processes that occur simultaneously complicate the problem. A preliminary mathematical model of the snowmelt process has been developed in which processes such as pack settlement rates and energy flow in the pack by means of both conduction and liquid movement are considered. Factors such as an temperature, surface albedo, and degree and direction of slope are also included. A temperature criterion is applied to predict the form of precipitation input (snow or rain) to the model. Equations of the various processes are synthesized into a dynamic model of the total system by means of an electronic analog computer. This computer was utilized primarily because of its ability to (1) perform repetitive operations at very high speeds and (2) solve directly the several time-dependent partial differential equations included in the model. Field data from snow laboraties operated by the Corps of Engineers and highly instrumented watersheds of the Agricultural Research Service are being used to test and verify the model. Inital results have indicated close agreement between observed and computed results. Sensitivity studies have been conducted, and work is continuing to further test and improve the model

Hybrid Computer Simulation of the Accumulation and Melt Processes in a Snowpack

This study represents the first phase of an investigation to develop an operational simulation model of the point snowmelt process based on a time increment of one day or less. Mathematical relationships for various phenomena involved in the snowmelt process were proposed and tested. These relationships were combined into a model which is applicable to any geographic locations by determining appropriate constants for certain relationships. The model was synthesized on a hybrid computer and calibrated using field data from the Central Sierra Snow Laboratory. It was then tested with data from other well instrumented locations. Sensitivity tests were also conducted to study the relative effects of the various basic parameters and functions upon the melting process. Initial tests of the model proved encouraging and suggested merit in perusing a proposed subsequent phase of the project to incorporate the watershed runoff hydrographs resulting from a melting snowpack will be simulated

Increasing On-Task Behavior Using Teacher Attention Delivered on a Fixed-Time Schedule

The effectiveness of fixed-time delivery of attention to increase the on-task behavior of 2 students in general education was examined. The teacher in this study provided attention to students on a 5-min fixed-time schedule and responded to students in her typical manner between cued intervals. An ABAB withdrawal design was used to test the effects of the intervention. The results of this study indicate that a fixed-time schedule of attention was effective in increasing students’ on-task behavior and decreasing their off-task behavior. Implications of the study for research and practice are discussed