The durability of fly ash concrete in marine and softwater environments

Concrete is attacked by aggressive agents in the marine and softwater environments which reduce the durability of concrete. To help lessen the effect of this aggressive attack, fly ash concrete has been recommended for use in these environments. The lower permeability, increased chemical resistance and higher long-term strength of fly ash concrete are expected to improve the concrete durability. In this research the effect of fly ash was investigated with regard, initially to general concrete properties such as bleeding, early set, workability, mortar excess and compressive strength. Lethabo field 2 fly ash and Western Cape materials were used for this work. Having developed a wide range of concrete mixes, further investigation was done into specific concrete properties such as the effect of different curing regimes, water absorption, permeability and freeze-thaw resistance. These properties are considered to have an influence on concrete durability. Comparisons were made between the concrete properties of Lethabo field 2, Lethabo classified and Matla classified fly ash concrete. The three types of concrete were tested for compressive strength, sorptivity (rate of water absorption) and density. At the same time, fly ash and OPC concrete samples were exposed to the marine and softwater environment for up to 10 months. Marine exposure was done in the submerged, tidal and spray zones in Table Bay. Softwater exposure was done at Constantia Nek and Steenbras Water Treatment Plants. The performance of concrete in the various exposure conditions was measured by compressive strength, sorptivity and density tests. Fly ash improved many of the properties of concrete, with fly ash concrete having better workability, higher long-term strength, reduced bleeding, lower sorptivity and reduced permeability than similar OPC concrete. Some of the properties of concrete were however worsened by using fly ash. Fly ash concrete had longer setting times, reduced resistance to freezing and thawing and was more adversely affected by dry curing than similar OPC concrete. Lethabo field 2 fly ash concrete had higher compressive strength and lower sorptivity than either Lethabo classified or Matla classified fly ash concrete. The long-term performance of Lethabo classified and Matla classified fly ash concrete was better than that of Lethabo field 2 fly ash concrete, with regard to compressive strength development and sorptivity reduction. Fly ash concrete performed well in both the marine and softwater environments. After 10 months of exposure in either marine or softwater conditions, fly ash concrete had higher compressive strength and lower sorptivity than similar OPC concrete. The good performance of fly ash concrete in the marine and softwater environment confirmed the ability of fly ash to improve many of the important durability properties of concrete. From this medium-term durability investigation it was found that Lethabo field 2 fly ash improved the performance of concrete in marine and softwater environments while fly ash, in general, improved many of the durability properties of concrete

Sovereignty in Antarctica: The Anglo-Argentine Dispute

The purpose of this article is to examine the relevant arguments of Argentina and Great Britain and, in light of an analysis of the theories of territorial sovereignty and prior decisions, to suggest that, should the dispute be referred for decision to the International Court of Justice, Argentina has a formidable array of arguments at her disposal. It may be argued that the opportunity for decision by the Court is foreclosed by the existence of the Antarctic Treaty, that the issue of territorial sovereignty in Antarctica is moot. It is submitted, however, that the possibility of a Court determination is a substantial one for three significant reasons outlined in the paper

Reviewing Literature and Exploring Concept of Leadership for Learning to Organizational Values – HR Insights From Hospitality and Retail Industries in Hong Kong

Purpose: The aim of this study is to explore previous and latest literature, as well as examine the concept of leadership for learning to organizational values.   Theoretical framework: This theoretical framework tentatively projects effective leadership to the development of learning aligning with organizational values within an organization, it specifically focuses on hospitality and retailing from HR in Hong Kong. The framework includes the alignment of learning, learning culture, leadership, organizational values, and HR practices.   Design/methodology/approach: The concept of leadership for learning to organizational values were explored by literature with a matrix created, and tentatively formed 6 items for data collection from HR and related professionals, with 116 responses. Exploratory factor analysis was carried out by SPSS software.   Findings: With the factor loading required at least over 0.6 (the actual value of each item was higher than 0.8) as well as the scale over 0.9, the results showed those 6 items as one component of leadership for learning to organizational values.   Research, Practical & Social implications: The study practically implied the importance of leadership to employee, team and organizational learning. The allowed HR be more insightful in future practice and policy, regarding the association of learning, culture, organizational value as well as leadership.   Originality/value: The value of the study significantly explored the interconnection of learning, culture, leadership and organizational values in the specified Hong Kong’s context in hospitality and retailing. It would be potentially valuable for HRM practices and promotional organizational success in the future

The Effect of Tree Width on Thoracolumbar and Limb Kinematics, Saddle Pressure Distribution, and Thoracolumbar Dimensions in Sports Horses in Trot and Canter

This study evaluated the effect of saddle tree width on thoracolumbar and limb kinematics, saddle pressure distribution, and thoracolumbar epaxial musculature dimensions. Correctly fitted saddles were fitted by a Society of Master Saddler Qualified Saddle Fitter in fourteen sports horses (mean ± SD age 12 ± 8.77 years, height 1.65 ± 0.94 m), and were altered to one width fitting wider and narrower. Horses were equipped with skin markers, inertial measurement units, and a pressure mat beneath the saddle. Differences in saddle pressure distribution, as well as limb and thoracolumbosacral kinematics between saddle widths were investigated using a general linear model with Bonferroni adjusted alpha (p ≤ 0.05). Compared with the correct saddle width, in trot, in the wide saddle, an 8.5% increase in peak pressures was found in the cranial region of the saddle (p = 0.003), a 14% reduction in thoracolumbar dimensions at T13 (p = 0.02), and a 6% decrease in the T13 range of motion in the mediolateral direction (p = 0.02). In the narrow saddle, a 14% increase in peak pressures was found in the caudal region of the saddle (p = 0.01), an 8% decrease in the range of motion of T13 in the mediolateral direction (p = 0.004), and a 6% decrease in the vertical direction (p = 0.004) of T13. Compared with the correct saddle width, in canter, in the wide saddle, axial rotation decreased by 1% at T5 (p = 0.03) with an 5% increase at T13 (p = 0.04) and a 5% increase at L3 (p = 0.03). Peak pressures increased by 4% (p = 0.002) in the cranial region of the wide saddle. Altering the saddle fit had an effect on thoracolumbar kinematics and saddle pressure distribution; hence, correct saddle fit is essential to provide unhindered locomotion

The Role of Corrosion Inhibitors in Maintaining Concrete Durability; 15 Years Experience in New Zealand and around the World

The last thirty years have seen a growing demand for increased durability of concrete repairs. This period has seen improvements in the understanding of the causes of concrete deterioration, improvements in concrete repair products and in repair specifications (Tanner et al, 2012). The period has also seen development of advanced rehabilitation and protection methods such as corrosion inhibitors. Corrosion inhibitors for the construction industry were first developed in the 1950’s and a considerable volume of research has been undertaken by academic institutions and industry to quantify their effectiveness and limitations. This paper reviews some of these studies and the performance of repairs on the Scarborough Clock Tower near Christchurch. It concludes that corrosion inhibitors can be a good approach to adopt for providing cost effective improvements in concrete durability for concrete suffering from chloride and carbonation induced reinforcement corrosion

Relationship between saddle and rider kinematics, horse locomotion and thoracolumbar pressures in sound horses

Reason for performing the study: Saddle fit is considered to be a crucial factor for the health and performance of horses, yet there is a paucity of scientific data. Objective: To determine the relationship between saddle and rider kinematics, horse locomotion and thoracolumbar pressures in sound horses. Method: Seven horses with asymmetric saddle position were tested before and after correction of the saddle positioning asymmetry. Kinematic and kinetic data were collected using motion capture, inertial sensors and a pressure mapping system. Data of horses showing saddle roll to the right were normalised to represent saddle roll to the left. Results: When comparing saddle roll with saddle correction in trot, this study found that once the saddle had been corrected on the rein with saddle roll to the outside (here: right rein) there was an increase in outside front fetlock hyperextension (P=0.02) and inside hind fetlock hyperextension (P≤0.05); there was a reduction in peak pressures after saddle correction under the inside portion of the panel in trot (P≤0.05) and canter (P=0.04), riders showed increased thoracic side bend (lean) on the contralateral side to the direction of saddle roll (P=0.02). Conclusion: The presence of saddle roll creates changes in fetlock hyperextension and hence likely force production, increased peak pressures beneath the panel on the contralateral side to the direction of saddle roll and affects rider position, with the rider leaning in the opposite direction to saddle roll likely in order to optimise balance

An exploration of the use of technology in primary school physical education

Technology is one of the fastest growing areas of the global economy and it is recognised as having a major influence on the world's health through its integration in education (Miniwatts Marketing Group, 2010). Technology too is at the heart of the Scottish Curriculum for Excellence and schools are expected to integrate it both to enhance learning and teaching across each subject area, and to further the technological development of today's young 'digital natives' (Prensky, 2001). This paper seeks to explore the effectiveness of current technology and current use of technology in a quality primary school physical education (PE) through the exploration of two main issues: (1) what constitutes a quality PE experience? (2) in what ways does the use of technology influence the quality of the physical education experience? A study of the literature will identify the key features of a quality physical education and the key features will then be examined in context by conducting three case studies of different technologies in Scottish primary school physical education. Each case study is analysed individually; there are three significant correlations that emerged across all studies: -Technology increases intrinsic motivation -Technology increases pupils' development of social and emotional skills -The pedagogical approach to lessons using technology might be influenced by teacher confidence and competence