درخت حوزه‌های تخصصی

This research investigated the effect of insomnia caused by military guarding on motor performance and salivary cortisol and testosterone concentration. Some 24 male active-duty soldiers were randomly selected and placed in two groups, insomnia, and control. Insomnia consisted of two hours of guarding with military equipment, two hours of on-call, and two hours of sleep, which started at 4:00 PM and lasted until 6:00 AM the next day. Agility, balance, and reaction time were measured as indicators of motor performance. Saliva samples were collected in the morning two days before, in the morning after applying insomnia, and after measuring motor performance. The results showed that agility performance in the insomnia group was weaker than in the control group. The balance performance of the insomnia group did not differ significantly from the control group. The reaction time in the experimental group was slower when compared to the control group. Although the reaction time was affected significantly, the findings of this research showed that salivary cortisol and testosterone concentration, as well as agility and balance, are not affected by this amount/type of sleep deprivation.

Soil is among the cheapest and most available materials found in the human living environment. Seeking refuge in the heart of earth and benefitting from soil’s thermal property, based on experience, is a strategy employed in the past across some regions. Also the passive systems are amongst the cheapest methods of providing heating and cooling demands of the buildings. These systems experience the lowest impact of environmental degradation while increasing the energy efficiency of the building through decreasing heat gain and loss. The idea of the earth-sheltered buildings is amongst the passive construction that has been embraced by the architects. An earth-sheltered building, as a passive idea, can guarantee, extensively, the reduction of energy consumption and provides the required conditions for thermal comfort. The present study discusses and investigates the thermal performance of earth-sheltered residential buildings in Yazd city of Iran. To predict this type of constructional thermal behavior, subsequent to field and library studies, thermal simulation was employed using Energy Plus software. Energy Plus software is able to simulate the envelopes adjacent to soil. The simulation process is conducted through depth changing of the soil surrounding the sample, assuming its thermal properties are constant. Considering to the results, by increasing the depth of sheltering in amount of soil, its energy consumption saving will increase. In this situation annual temperature fluctuation decreases 50% and it saves about 67% of energy consumption. In addition the most hours set on thermal comfort zone. This subject adds 50 more days to annual Earth-Sheltered acceptable thermal comfort conditions. Moreover due to investigating of the building orientation as an effective element for energy consumption, south orientation is specified as the best position for energy reduction in Earth-Sheltered.