Dielectric permittivity in the x-ray region (original) (raw)
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Dielectric Relaxation in Por-Si Layers at Low Frequencies
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Siberian Journal of Physics, 2014
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Издательство «Фəн» Казань, Татарстан Главный редактор Член-корреспондент АН РТ Ф.Ш. Хузин Заместители главного редактора: доктор исторических наук А.Г. Ситдиков доктор исторических наук Ю.А. Зеленеев Ответственный секретарь-кандидат ветеринарных наук Г.Ш. Асылгараева Редакционный совет: Р.С. Хакимоввице-президент АН РТ (Казань, Россия) (председатель) Х.А. Амирхановчлен-корреспондент РАН, доктор исторических наук, профессор (Махачкала, Россия) И. Бальдауфдоктор наук, профессор (Берлин, Германия) П. Георгиевдоктор наук, доцент (Шумен, Болгария) Е.П. Казаковдоктор исторических наук (Казань, Россия) Н.Н. Крадинчлен-корреспондент РАН, доктор исторических наук, профессор (Владивосток, Россия) А. Тюрк-PhD (Будапешт, Венгрия) И. Фодордоктор исторических наук, профессор (Будапешт, Венгрия) В.Л. Янинакадемик РАН, доктор исторических наук профессор (Москва, Россия) Редакционная коллегия: А.А. Выборнов-доктор исторических наук, профессор (Самара, Россия) М.Ш. Галимова-кандидат исторических наук (Казань, Россия) Р.Д. Голдина-доктор исторических наук, профессор (Ижевск, Россия) И.Л. Измайлов-кандидат исторических наук (Казань, Россия) С.В. Кузьминых-кандидат исторических наук (Москва, Россия) А.Е. Леонтьев-доктор исторических наук (Москва, Россия) Т.Б. Никитина-доктор исторических наук (Йошкар-Ола, Россия) Ответственный за выпуск: Б.Л. Хамидуллинкандидат исторических наук (Казань, Россия)
Fire Hazards Caused by Dielectric Permittivity – Evaluation of Pine Needles Moisture Content
2015
Aim: To carry out an evaluation of pine needles moisture content, an important factor which contributes to fire hazards as a result of dielectric properties. Such an evaluation facilitates a speedy diagnosis of a fire hazard in pine forests An analysis was performed on the impact of physical and chemical properties of pine needles on the potential fire hazard Introduction: Moisture content of pine needles has an impact on properties associated with fire hazards. Traditional moisture determining methods consume much time and require specialist pre-calibrated measuring instruments and techniques. Therefore, the article proposes a method of evaluating pine needles moisture content, based on dielectric permittivity principles, expressed by the capacitance of a capacitor containing pine needles located between its plates. Project and methods: Experimental studies of dry pine needles were performed in a laboratory. Pine needles were stored at the constant air temperature of 20 ± 1°С and relative humidity of 46 ± 2% until uniform moisture content was achieved. Subsequently, the pine needles were dried for 2 hours, in an oven, at a temperature of 100 ± 5°C. The moisture content of pine needles was determined for each day of research by weighing , using laboratory scales. The dielectric permittivity of pine needles was evaluated with the aid of a flat capacitor, by placing a specified number of pine needles between its plates. This capacitor was connected to a capacitance measuring device . Statistical analysis methods and corresponding software were used for data processing. Results: Dielectric permittivity changes were mapped using changes to the capacitor’s capacitance, with pine needles located between its plates. Identified the dependence relationships between moisture content of pine needles and drying time, as well as capacitance of the capacitor containing pine needles and drying time. Capacitance is proportional to dielectric permittivity, therefore, dielectric permittivity falls in parallel with a decrease in moisture content. Using regression analysis, linear and polynomial trends were identified , describing the dependence relationship between moisture content of needles and capacitance. Direct quantification of dielectric permittivity of pine needles is complicated by the presence of air among pine needles located between plates. Therefore diagnosis of a fire hazard should be performed using capacitance of a capacitor with pine needles between its plates rather than dielectric permittivity. Conclusions: Evaluation of pine needles moisture content, with pines located between the plates of a capacitor, has an impact on the capacitor’s capacity, which facilitates a speedy prediction of fire hazard levels.