Oral application of L-menthol in the heat: From pleasure to performance

When menthol is applied to the oral cavity it presents with a familiar refreshing sensation and cooling mint flavour. This may be deemed hedonic in some individuals, but may cause irritation in others. This variation in response is likely dependent upon trigeminal sensitivity toward cold stimuli, suggesting a need for a menthol solution that can be easily personalised. Menthol’s characteristics can also be enhanced by matching colour to qualitative outcomes; a factor which can easily be manipulated by practitioners working in athletic or occupational settings to potentially enhance intervention efficacy. This presentation will outline the efficacy of oral menthol application for improving time trial performance to date, either via swilling or via co-ingestion with other cooling strategies, with an emphasis upon how menthol can be applied in ecologically valid scenarios. Situations in which performance is not expected to be enhanced will also be discussed. An updated model by which menthol may prove hedonic, satiate thirst and affect ventilation will also be presented, with the potential performance implications of these findings discussed and modelled. Qualitative reflections from athletes that have implemented menthol mouth swilling in competition, training and maximal exercise will also be included

The effectiveness of orally applied L-menthol on exercise performance in the heat

During exercise in the heat, increasing thermal load leads to thermo-behavioural adjustments in exercise performance, due to greater perceptual and physiological strain. Behavioural reductions in exercise intensity in the heat are initially mediated via rises in skin temperature, which alter thermal perception (comfort and sensation) and later by rises in core temperature, which increase cardiovascular strain and perceived exertion. Therefore, thermoregulation may be ordered and dependant on the magnitude, timing and/or prioritisation of afferent signals. Non-thermal cooling via L-menthol has been shown to enhance exercise performance in the early and latter stages when delivered orally at a concentration of 0.01%. Indeed, during periods of progressive thermal stress, imposed by the combination of maximal exercise and environmental heat and humidity, L-menthol has been shown to offer an immediate cooling stimulus thus extending exercise capacity. However, repeated administration of L-menthol during exercise in the heat, as thermal load increases, is unable to recover a decline in work rate. Therefore, it is unclear whether the potency of L-menthol is sustained upon frequent application and what strategies are needed in both sporting and occupational settings to optimise its effectiveness. In this part of the symposium we will consider oral delivery of L-menthol and its potential for reducing an individual’s perception of heat stress with associated effects on exercise tolerance in the heat. We will also examine the frequency of use, optimal concentration, timing and novelty of L-menthol in a sporting and occupational context

An Analysis of the Percentage Distribution of Municipal and Rural School District Maintenance Funds for Selected Years of the Ten-Year Period, 1938-1948

It is the purpose of this study (1) to present and analyze the percentage distribution of the municipal and rural school district maintenance funds for the school years 1938-1939, 1941-1942, 1944-1945, and 1947-1928 for the following major classifications of current expense; a. general control, b. instruction, c. operation of the school plant, d. maintenance and fixed charges, and e. auxiliary and coordinate activities; (2) to determine the costs per pupil in average daily attendance for each of the above mentioned classifications of current expense for municipal and rural school districts for the stated years; and (3) to determine and compare the trends in the percentage distribution for the municipal and rural school district funds for the ten-year period, 1938-1948

Costs of hauling bulk milk from farm to plant

Also available online.Digitized 2007 AES

Experimental investigation on the dynamic response of RC flat slabs after a sudden column loss

To prevent disproportionate collapse under an extreme loading event, a sudden column loss scenario is often used to ensure the structure has suitable robustness. This study aims to investigate experimentally the dynamic response of reinforced concrete flat slabs after a sudden column loss. Seven 1/3 scale reinforced concrete flat slabs were tested under static load increases or dynamic column removal cases with different supports removed. Reaction forces and deflections were recorded throughout, along with reinforcement strains and concrete cracking patterns. During dynamic tests, a high speed camera was used to capture the dynamic motion. The experiments demonstrated that flat slabs, in general, are able to redistribute their loading effectively after a column loss. Although large levels of damage were observed, collapse due to flexural failure did not occur. However, punching shear was shown to be an issue due to the additional vertical loading on the adjacent supports. The inclusion of continuous bottom reinforcement through a column did not significantly improve the capacity, as the new load path is not primarily through the removed column location. The results also indicate that the dynamic effects due to a sudden column loss can be significant as deflections of up to 1.5 times the static case were measured within the elastic range. It is also shown that the Dynamic Amplification Factor (DAF) reduces when nonlinear damaging effects are included, which implies conventional code-based design methods for flat slab structures may be over conservative. Additionally, the increase in material strength due the strain rates is not viewed to be significant

Warpage issues in large area mould embedding technologies

The need for higher communications speed, heterogeneous integration and further miniaturisation have increased demand in developing new 3D integrated packaging technologies which include wafer-level moulding and chip-to-wafer interconnections . Wafer-level moulding refers to the embedding of multiple chips or heterogeneous systems on the wafer scale. This can be achieved through a relatively new technology consisting of thermal compression moulding of granular or liquid epoxy moulding compounds. Experimental measurements from compression moulding on 8” blank wafers have shown an unexpected tendency to warp into a cylindrical-shape following cooling from the moulding temperature to room temperature. Wafer warpage occurs primarily as a result of a mismatch between the coefficient of thermal expansion of the resin compound and the Si wafer. This paper will delve into possible causes of such asymmetric warpage related to mould, dimensional and material characteristics using finite element (FE) software (ANSYS Mechanical). The FE model of the resin on wafer deposition will be validated against the measurement results and will be used to deduce appropriate guidelines for low warpage wafer encapsulation.peer-reviewe

Dynamic column loss analysis of reinforced concrete flat slabs

The sudden column loss idealisation is a useful design tool to assess structures for progressive collapse. As such an event is a dynamic problem, suitable account must be taken of these effects. This can either be achieved by a full dynamic analysis of the structure or a simplified static approach, with correction factors for the dynamic influence. This study aims to investigate the response of Reinforced Concrete (RC) flat slab structures after a column loss using experimentally validated Finite Element (FE) models. The nonlinear dynamic response of a structure after such an event is considered, including the redistribution of loads and displacement profile. These results are then compared to equivalent static cases in order to determine the Dynamic Amplification Factor (DAF). For the range of structures considered, the DAF was calculated as between 1.39 and 1.62 for displacements, with lower factors associated with a higher nonlinear response or slower column removal. Additionally, the shear forces in remaining columns may exceed 200% of their fully supported condition, with a different associated DAF. The effects of increasing the tensile strength of concrete due to high strain rates are also considered. Typical Dynamic Increase Factors (DIFs) based on the strain rates were up to 1.23, however, this only applied for a short time period, and in a limited area. Therefore, such effects do not significantly influence the response