On A New Weighted Exponential Distribution: Theory and Application

A new two-parameter weighted exponential distribution which has more mild algebraic properties than the existing weighted exponential distribution was studied. Explicit expressions for some of its basic statistical properties including moments, reliability analysis, quantile function and order statistics were derived. Its parameters were estimated using the method of maximum likelihood estimation. The new probability model was applied to four real data sets to assess its flexibility over the existing weighted exponential distributio

Effects of a Customized Professionalism Educational Intervention on Physical Therapists’ Knowledge and Attributes of Professionalism

Purpose: There is a growing call around the world to include professionalism in the entry-level education of physical therapists and to teach professionalism as a continuing education professional development workshop for practicing physical therapists. Unfortunately, there is currently no empirical evidence to support the use of didactic instruction to effectuate a change in the knowledge and attributes of professionalism. This study evaluated the effects of a customized professionalism educational intervention on physical therapists’ knowledge and attributes of professionalism. Methods: A quasi-experimental research was conducted among 47 Nigerian physical therapists (Mean age = 41 ± 10.1 years). The educational intervention consisted of a 3-hour classroom lecture and five case studies on professionalism. The impact of the intervention was evaluated by a Professionalism Inventory that assesses the level of knowledge and attributes of professionalism - clinical competence, a spirit of inquiry, accountability, autonomy, advocacy, innovation and visionary, collegiality and collaboration, and ethics and value. Results: Post intervention, the physical therapist\u27s aggregate knowledge of professionalism score improved significantly from 69% to 77% performance level (t = 2.340; p \u3c 0.05). On the contrary, there was no significant difference in the aggregate attributes of professionalism score following the intervention (t = 1.396, p \u3e 0.05). Although the improvement observed in the aggregate attributes of professionalism score was not statistically significant, when the effects of the intervention were examined on the attributes of professionalism subscales, the results revealed that clinical competence, accountability, autonomy, innovation and visionary, and collaborating and collegiality improved significantly (p \u3c 0.05). The intervention was of small practical significance (Cohen d = .34 and .20 for knowledge and attributes of professionalism scores, respectively). Conclusions: It was inferred from the findings that a three-hour classroom instruction consisting of lectures and case studies presentation could improve the knowledge of professionalism of practicing physical therapists. A longer instructional period vis-à-vis mentoring and role modelling in the classroom may be needed to effectuate a practical change in professionalism

On A New Weighted Exponential Distribution: Theory and Application

A new two-parameter weighted exponential distribution which has more mild algebraic properties than the existing weighted exponential distribution was studied. Explicit expressions for some of its basic statistical properties including moments, reliability analysis, quantile function and order statistics were derived. Its parameters were estimated using the method of maximum likelihood estimation. The new probability model was applied to four real data sets to assess its flexibility over the existing weighted exponential distributio

The Weibull-Exponential Distribution: Its Properties and Applications

A three parameter probability model, the so called Weibull-exponential distribution was proposed using the Weibull Generalized family of distributions. Some important models in the literature were found to be sub models of the new model. Explicit expressions for some of its basic mathematical properties like moments, moment generating function, reliability analysis, limiting behavior and order statistics were derived. The method of maximum likelihood estimation was proposed in estimating its parameters and real life applications were provided to illustrate its flexibility and potentiality over the exponential distribution

Isolation and Characterization of Steroids from Petroleum Ether Extract of Stem Bark of Parinari curatellifolia Planch ex. Benth (Chrysobalanaceae)

In our search for biologically active compounds, three steroids have been isolated from the stem bark of Parinari curatellifolia through series of column chromatography. Compound C1, C2 and C3 where characterized as ?-sitosterol (22,23-dihydrostigmasterol), stigmast-4-en-3-one and stigmasterol, respectively, on the basis of 1D-NMR (1HNMR, 13CNMR and DEPT-135), 2D-NMR (HSQC, HMBC, 1H-1H COSY,  1H-1H NOESY), mass spectroscopy (MS) and IR spectroscopy. These compounds are reported for the first time as constituents in Parinari curatellifolia. Keywords: Parinari curatellifolia, ?-sitosterol, stigmast-4-en-3-one and stigmastero

A Review of Forecasting Techniques

This work examines recent publications in forecasting in various fields, these include: wind power forecasting; electricity load forecasting; crude oil price forecasting; gold price forecasting energy price forecasting etc. In this review, categorization of the processes involve in forecasting are divided into four major steps namely: input features selection; data pre-processing; forecast model development and performance evaluation. The various methods involve are discussed in order to provide the overall view about possible options for development of forecasting system. It is intended that the classification of the steps into small categories with definitions of terms and discussion of evolving techniques will provide guidance for future forecasting sytem designers

Tin (II) Chloride a Suitable Wetting agent for AA1200 - SiC Composites

SiC reinforced Aluminum samples were produced by stir casting of liquid AA 1200 aluminum alloy at 600-650 ºC casting temperature. 83µm SiC particles were rinsed in 10g/l, 20g/l and 30g/l molar concentration of Sncl2 through cleaning times of 0, 60, 120, and 180 minutes. Some cast samples were tested for mechanical properties and some were subjected to heat treatment before testing. The SnCl2 rinsed SiC reinforced aluminum exhibited higher yield strength, hardness, stiffness and elongation which increases with cleaning concentration and time up to 120 minutes, compared to composite with untreated SiC. However, the impact energy resistance decreases with cleaning concentration and time. The improved properties were attributed to good wettability and mechanical adhesion at the fiber-matrix interface. Quenching and annealing the composite samples further improve the tensile/yield strengths, elongation, stiffness, hardness similar to those of the as-cast samples

Tin (II) Chloride a Suitable Wetting agent for AA1200 - SiC Composites

SiC reinforced Aluminum samples were produced by stir casting of liquid AA 1200 aluminum alloy at 600-650 ºC casting temperature. 83µm SiC particles were rinsed in 10g/l, 20g/l and 30g/l molar concentration of Sncl2 through cleaning times of 0, 60, 120, and 180 minutes. Some cast samples were tested for mechanical properties and some were subjected to heat treatment before testing. The SnCl2 rinsed SiC reinforced aluminum exhibited higher yield strength, hardness, stiffness and elongation which increases with cleaning concentration and time up to 120 minutes, compared to composite with untreated SiC. However, the impact energy resistance decreases with cleaning concentration and time. The improved properties were attributed to good wettability and mechanical adhesion at the fiber-matrix interface. Quenching and annealing the composite samples further improve the tensile/yield strengths, elongation, stiffness, hardness similar to those of the as-cast samples

Tin (II) Chloride a Suitable Wetting agent for AA1200 - SiC Composites

SiC reinforced Aluminum samples were produced by stir casting of liquid AA 1200 aluminum alloy at 600-650 ºC casting temperature. 83µm SiC particles were rinsed in 10g/l, 20g/l and 30g/l molar concentration of Sncl2 through cleaning times of 0, 60, 120, and 180 minutes. Some cast samples were tested for mechanical properties and some were subjected to heat treatment before testing. The SnCl2 rinsed SiC reinforced aluminum exhibited higher yield strength, hardness, stiffness and elongation which increases with cleaning concentration and time up to 120 minutes, compared to composite with untreated SiC. However, the impact energy resistance decreases with cleaning concentration and time. The improved properties were attributed to good wettability and mechanical adhesion at the fiber-matrix interface. Quenching and annealing the composite samples further improve the tensile/yield strengths, elongation, stiffness, hardness similar to those of the as-cast samples

Using the jet stream for sustainable airship and balloon transportation of cargo and hydrogen

© 2019 The Author(s) The maritime shipping sector is a major contributor to CO2 emissions and this figure is expected to rise in coming decades. With the intent of reducing emissions from this sector, this research proposes the utilization of the jet stream to transport a combination of cargo and hydrogen, using airships or balloons at altitudes of 10–20 km. The jet streams flow in the mid-latitudes predominantly in a west–east direction, reaching an average wind speed of 165 km/h. Using this combination of high wind speeds and reliable direction, hydrogen-filled airships or balloons could carry hydrogen with a lower fuel requirement and shorter travel time compared to conventional shipping. Jet streams at different altitudes in the atmosphere were used to identify the most appropriate circular routes for global airship travel. Round-the-world trips would take 16 days in the Northern Hemisphere and 14 in the Southern Hemisphere. Hydrogen transport via the jet stream, due to its lower energy consumption and shorter cargo delivery time, access to cities far from the coast, could be a competitive alternative to maritime shipping and liquefied hydrogen tankers in the development of a sustainable future hydrogen economy