Youth Sports: Implementing Findings and Moving Forward with Research

This paper reviews the literature, outlines practical implications, and discusses future studies in youth sport researc h. The literature is discussed in light of three potential benefits of youth sport participation 1) physic al health, 2) psycho- social development, and 3) motor skills acquisition. The ultimate objective of youth sport programs is to consider all the benefits of youth sport participation rather than focusing on one or two at the cost of the other(s). It is suggested that researchers, s port administrators, coaches, and parents work together to promote sporting activities and programs that are more likely to enhance children’s physical health, psychosocia l development and lifelong recreational or elite sport participation.

The Economic Case for Electric Mining Equipment and Technical Considerations Relating to their Implementation

Underground hardrock mining can be very energy intensive and in large part this can be attributed to the power consumption of underground ventilation systems. In general, the power consumed by a mine’s ventilation system and its overall scale are closely related to the amount of diesel power in operation. This is because diesel exhaust is a major source of underground air pollution, including diesel particulate matter (DPM), NO2 and heat, and because regulations tie air volumes to diesel engines. Furthermore, assuming the size of airways remains constant, the power consumption of the main system increases exponentially with the volume of air supplied to the mine. Therefore large diesel fleets lead to increased energy consumption and can also necessitate large capital expenditures on ventilation infrastructure in order to manage power requirements. Meeting ventilation requirements for equipment in a heading can result in a similar scenario with the biggest pieces leading to higher energy consumption and potentially necessitating larger ventilation tubing and taller drifts. Depending on the climate where the mine is located, large volumes of air can have a third impact on ventilation costs if heating or cooling the air is necessary. Annual heating and cooling costs, as well as the cost of the associated infrastructure, are directly related to the volume of air sent underground. This thesis considers electric mining equipment as a means for reducing the intensity and cost of energy consumption at underground, hardrock mines. Potentially, electric equipment could greatly reduce the volume of air needed to ventilate an entire mine as well as individual headings because they do not emit many of the contaminants found in diesel exhaust and because regulations do not connect air volumes to electric motors. Because of the exponential relationship between power consumption and air volumes, this could greatly reduce the amount of power required for mine ventilation as well as the capital cost of ventilation infrastructure. As heating and cooling costs are also directly linked to air volumes, the cost and energy intensity of heating and cooling the air would also be significantly reduced. A further incentive is that powering equipment from the grid is substantially cheaper than fuelling them with diesel and can also produce far fewer GHGs. Therefore, by eliminating diesel from the underground workers will enjoy safer working conditions and operators and society at large will gain from a smaller impact on the environment. Despite their significant potential, in order to produce a credible economic assessment of electric mining equipment their impact on underground systems must be understood and considered in their evaluation. Accordingly, a good deal of this thesis reviews technical considerations related to the use of electric mining equipment, especially ones that impact the economics of their implementation. The goal of this thesis will then be to present the economic potential of implementing the equipment, as well as to outline the key inputs which are necessary to support an evaluation and to provide a model and an approach which can be used by others if the relevant information is available and acceptable assumptions can be made.

The Effects of Several Paper Characteristics and Application Methods on the Sublimation Rate of Cyclododecane

Cyclododecane (CDD) is a waxy, solid cyclic hydrocarbon (C12H24) that sublimes at room temperature and possesses strong hydrophobicity. In paper conservation CDD is used principally as a temporary fixative of water-soluble media during aqueous treatments. Hydrophobicity, ease of reversibility, low toxicity, and absence of residues are reasons often cited for its use over alternative materials although the latter two claims continue to be debated in the literature. The sublimation rate has important implications for treatment planning as well as health and safety considerations given the dearth of reliable information on its toxicity and exposure limits. This study examined how the rate of sublimation is affected by fiber type, sizing, and surface finish as well as delivery in the molten phase and as a saturated solution in low boiling petroleum ether. The effect of warming the paper prior to application was also evaluated. Sublimation was monitored using gravimetric analysis after which samples were tested for residues with gas chromatography-flame ionization detection (GC-FID) to confirm complete sublimation. Water absorbency tests were conducted to determine whether this property is fully reestablished. Results suggested that the sublimation rate of CDD is affected minimally by all of the paper characteristics and application methods examined in this study. The main factors influencing the rate appear to be the thickness and mass of the CDD over a given surface area as well as temperature and ventilation. The GC-FID results showed that most of the CDD sublimed within several days of its disappearance from the paper surface regardless of the application method. Minimal changes occurred in the water absorbency of the samples following complete sublimation.