introduction: the aim of this study was to investigate the scanning electron microscope (sem) analysis of tooth surface irradiated by different parameters of er:yag laser. methods: 15 caries-free extracted human third molars were used in this study. the teeth were put into 5 groups for laser irradiation as follows: group 1 (power: 2.5 w, energy: 250 mj); group 2(power: 3 w, energy: 300 mj); gro...

purpose the aim of this study was to determine the effect of one night's sleep deprivation on anaerobic performance and reaction time of subjects in the morning of the following day. methods eighteen male college student athletes were studied twice in a balanced, randomized design. subjects were measured for peak power, mean power and reaction time. results the performance showed no significant...

map is the most important tool for cognizance in the field of geography and is the best instrument for presentation of geographic information. the study of ecology in general, which means the study of relationship between man and his environment, is only possible by means of maps. as a tool for ecology and manifestation of human sovereignty over environment, the map has served political power-h...

this paper presents a new method to reduce consumption power in flash adc in 65nm cmos technology. this method indicates a considerable reduction in consumption power, by removing comparators memories. the simulations used a frequency of 1 ghz, resulting in decreased consumption power by approximately 90% for different processing corners. in addition, in this paper the proposed method was desig...

using photovoltaic systems is gradually expanded by increasing energy demand. abundance and availability of this energy, has turned to one of the most important sources of renewable energy. unfortunately, photovoltaic systems have two big problems: first, those have very low energy conversion efficiency (in act between 12 and 42 percent under certain circumstances). second, the power produced b...

this paper compares the value relevance of book value and dividends versus book value and reported earnings. the main purpose of this study explains which of dividends, book value and earnings are more value relevance. thus, we have examined 98 firms of tehran stock exchange over a period 1377-1382. our methodology of examining the information content of various income statement and balance she...

Introduction: Proton therapy is a type of radiation treatment that it uses protons to treat cancer. Because of the protons’ unique ability to distribute the radiation dose more directly to the tumor, it minimizes the damage to nearby healthy tissues. The rate of energy loss by the ion in the target is called stopping power. The total stopping power is sum nuclear and electroni...