A B S T R A C T R I~ S U M i ~The paper presents the results of a scientific research program focused on determining the effect of the fine particles content in granular stone materials on particular properties of the unstabilized base course. Grain-size distribution of a granular system was within the defined limits, and the percentage of fine particles (< 0.02 mm in diameter) ranged from 0 to 10% by mass. Two types of fine particles were tested, those of stone and clay origin. The specimens were compacted using five energy levels. Used lab. equipment was in compliance with the requirements of German (DIN) and Swiss (SNV) standards.The following characteristics were tested: -bearing capacity (CBR test) at optimum moisture content and after one freezing/thawing cycle -permeability (coefficient of permeability k).The obtained results were statistically analyzed and graphically presented. The most important outputs are:(a) Bearing capacity -within the research limits of 0 to 10% by mass, fine stone particles have positive effect and the bearing capacity increases, -fine clay particles content not higher than 5% by mass is acceptable; for higher percentages, the bearing capacity decreases.(b) Permeability -for fine stone particles content below 5% by mass permeability is still satisfactory; however, even a very small percentage of fine clay particles has an adverse impact on permeability.The conclusions are related to the tested materials and should be used as starting point for further investigation. Get article pre'sente les r&ultats d'un programme de recherche scientifique dont l'objet a cons#td a ddterminer l'influence des fines dam un mat&iau gmnuld sur certaines propridt& de la couche portante non li&. La granulomdtrie des mat&iaux a dt8 fix& dam les limites prescrites et la part destines (d'un diam&tre de 0,02 mm) a varid entre 0 et 10% en masse. Deux esp&es de fines ont dtd examin&s : le filler et l' argile. Les Ochantillons ont dt8 compact& en cinq degr&. Les appareils utih'se's dam les essais en laboratoire sont conformes aux normes allemandes (DIN) et suisses ($NV).Les propri&& suivantes ont ~t~ {tudi&s :
SUMMARY -Th ere are many false assumptions, both in the general population and among physicians, regarding the infl uence of radiation on pregnant patients and the fetus during diagnostic procedures, in spite of scientifi c facts based on studies. Th ese false assumptions are mostly based on the idea that every diagnostic procedure using ionizing radiation is a cause for serious concern and that artifi cial abortion as a possible solution might be considered. We analyzed data from counseling of pregnant patients exposed to ionizing radiation during diagnostic procedures in the Merkur University Hospital during a 4-year period. In this period, 26 patients presented for counseling after exposure to diagnostic ionizing radiation during pregnancy. Results showed most of these patients to have been exposed to radiation between the 2 nd and 3 rd week of gestation (36%), between the 4 th and 5 th week 32%, before the 2 nd week 24%, and after the 6 th week of gestation less than 8%. To provide reasonable estimate of fetal doses, Report No. 174 from the National Council on Radiation Protection and Measurements (NCRP) was used. Data from the Report include estimate of the fetal dose from direct and indirect exposures. Th e mean doses were up to 0.01 cGy in 46.2%, 0.01-0.15 cGy in 19.2%, 0.2-1 cGy in 26.9% and 1 cGy or more in 7.7% of patients. None of the counseled patients had medical indication for abortion, even though in a small percentage of patients abortion was a personal subjective decision. Considering that there are no Croatian guidelines for counseling patients exposed to ionizing radiation during pregnancy, it is recommended to use the International Commission on Radiological Protection guidelines in the management of pregnant patients exposed to ionizing radiation.
Objective The objective of the study was to assess the quality of root canal fillings of cases referred to endodontic surgery using preoperative radiographs and correlate it with endodontic surgery treatment decision. The objective was also to analyse clinical symptoms and size of periapical lesions on radiographs and correlate them with treatment decisions including non-surgical retreatment, endodontic surgery and extraction. Materials and Methods A questionnaire was composed to record the data. Eighty-six patients with 109 teeth, who were referred to endodontic surgery, participated in the research. The quality of root canal filling was assessed according to its homogeneity and filling length on digital radiographs. The data were analyzed using χ2-test and t-test. Results Of the teeth referred to endodontic surgery, 97.2% were treated by a general practice dentist, endodontic retreatment was attempted in 20.6%, and root canal filling was homogeneous and within 1 mm from the apex in 21.6%. Endodontic surgery, retreatment, extraction and no treatment were selected in 90.1%, 5.4%, 1.8% and 2.7% of the cases, respectively. Conclusions Low percentage of adequate root canal fillings and high percentage of endodontic surgery decisions suggest that there is a need to increase awareness of non-surgical retreatment options.
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