Removal of 2,4-dichlorophenoxyacetic Acid by Calcined Zn–Al–Zr Layered Double Hydroxide

The adsorption equilibrium, kinetics, and thermodynamics of removal of 2,4-dichlorophenoxy-acetic acid (2,4-D) from aqueous solutions by a calcined Zn–Al layered double hydroxide incorporated with Zr4+ were studied with respect to time, temperature, pH, and initial 2,4-D concentration. Zr4+ incorporation into the LDH was used to enhance 2,4-D uptake by creating higher positive charges and surface/layer modification of the adsorbent. The LDH was capable of removing up to 98% of 2,4-D from 5 to 400 ppm aqueous at adsorbent dosages of 500 and 5000 mg L−1. The adsorption was described by a Langmuir-type isotherm. The percentage 2,4-D removed was directly proportional to the adsorbent dosage and was optimized with 8% Zr4+ ion content, relative to the total metals (Zr4+ + Al3+ + Zn2+). Selected mass transfer and kinetic models were applied to the experimental data to examine uptake mechanism. The boundary layer and intra-particle diffusion played important roles in the adsorption mechanisms of 2,4-D, and the kinetics followed a pseudo-second order kinetic model with an enthalpy, ΔHads of −27.7 ± 0.9 kJ mol−1. Regeneration studies showed a 6% reduction in 2,4-D uptake capacity over six adsorption–desorption cycles when exposed to an analyte concentration of 100 ppm

School practitioners’ perceptions of the pre-service teacher education practicum: a comparative study

The importance of strong school-university partnerships in bridging the so-called theory- practice gap in pre-service teacher education has been well established in the literature. The experiences of pre-service teachers during practicum have in particular been shown to be enhanced where there are strong links between the two educational sectors. This paper draws from research conducted in two diverse Australian pre-service teacher education programs to evaluate factors that are perceived to profoundly impact on the professional experiences of pre-service teachers during practicum. The particular focus of this paper is the beliefs and experiences of school practitioners and university staff members regarding the efficacy of the practicum in enabling students to enact theory in practice. A mixed methods approach was adopted for both studies, one of which was located in an urban university in Tasmania, the other in a regional university in Queensland. Findings generated from the comparative study of both programs revealed some differences but predominantly a number of similarities between the perceptions of the two samples of school practitioners and university staff members towards practicum. Three key findings are presented and discussed in this paper

FINANCIAL CHARACTERISTICS OF REFRIGERATED FOOD PRODUCTS TRUCKING FIRMS IN THE U.S.

This study provides an overview of the financial characteristics of U. S. refrigerated food products trucking firms as a group and by regions. The analytical tools used for evaluating the financial assessment of the industry were several commonly used liquidity, profitability, and solvency ratios. One of the results reveals that the pre-tax income-to-gross revenue ratio, a measure of profitability, for the firms as a group averaged 0.01. This value means that one-cent of every dollar earned in services ("sales") was available to pay taxes and distribute profits.Agribusiness,

AN ANALYSIS OF MAJOR POULTRY PRODUCTS TRADERS IN WORLD MARKETS

This study evaluates the competitiveness of the United States and other major exporters of poultry products in world markets. The analytical technique used to measure the competitiveness of the major traders was the shift-share analysis model. One of the results from this study reveals that chicken meat exports from the U.S. relative to the countries in the world increased by 1,613,861 metric tons in time period 1985-95.International Relations/Trade,

\u27Global’ is not just ‘out there’ but also ‘right here’: expectations and experiences in internationalised and globalised higher education

This paper reports on a study that took a cross-disciplinary and cross-institutional approach to investigate postgraduate student expectations and experiences in internationalised and globalised higher education. The researchers drew on Giddens’ theory of structuration1. They explored the way samples of specialist medicine trainees in the UK and pre-service teacher education students in Australia identify and make meaning of their circumstances in an era that is increasingly characterised by greater internationalisation of the student body and more globalised curricula. In this paper, we discuss some of the tensions students reported encountering, and propose several ways in which such tensions might be counteracted

Building academic resilience: A longitudinal study of Master of Teaching students’ perceptions of written feedback on high stakes assessment

This paper reports on a two-year study of tertiary education students&rsquo; perceptions of written feedback on assessment. Contextualised in a regional Australian university and drawing on a cohort of Master of Teaching pre-service teachers, a survey approach was used to collect data from participants in both years of their graduate-level entry program. The paper contributes to the emerging body of literature on students&rsquo; perceptions of written feedback on assessment by discussing four themes that emerged from the study. It concludes with a number of recommendations for teacher educators to enhance current feedback practices.<br /

Using appreciative inquiry to frame the appraisal of an Australian initial teacher education program

This paper reports on a study that investigated the process and outcomes of using Appreciative Inquiry (AI) in an Australian initial teacher education (ITE) program review. The aim of the study, which drew on a sample of teaching staff involved in this Master of Teaching program, was to gain an understanding of the extent to which the application of the AI framework can be used effectively in the review of ITE programs. AI promotes collegial reflective practice and the generation of positive resolutions and thus aligned with the purposes of the review that were to foster collaboration, strengthen staff morale and, subsequently, build a stronger program for students. This paper provides a perceptual account of the AI review process as reported by the facilitators and a sample of review participants, and contributes to international literature in the areas of ITE program appraisal, organisational reform and Appreciative Inquiry

How school and university supervising staff perceive the pre-service teacher education practicum: A comparative study

This paper reports on research conducted in two Australian universities to evaluate factors that are perceived to significantly impact on the professional experiences of pre-service teachers during practicum. Contextualised within teacher education programs in an urban university in Tasmania and a regional university in Queensland, the particular focus of this paper is the beliefs and experiences of school and university supervising staff members regarding the efficacy of the practicum in enabling students to integrate into practice the knowledge and skills they have acquired in their university coursework. Findings generated from the comparative analysis of both mixed methods studies revealed some differences but predominantly a number of similarities between the perceptions of the two samples of school practitioners and university staff members towards practicum. Three key findings are presented and discussed in this paper