Dental casts come into direct contact with impression materials and other items that are contaminated by saliva and blood from a patient's mouth, leaving the casts susceptible to cross-contamination. The disinfectant solutions of the impression materials cause various adverse reactions. Therefore, disinfection of dental casts may be effective in preventing cross infection. This study was carried out to evaluate the surface hardness, dimensional accuracy, reproduction of details and surface porosity of type III, type IV and type IV extra hard dental stone after immersion in and spray by using SOLO and Sodium hypochlorite disinfectant solutions. Materials and methods: 240 Stone samples were prepared in rubber rings, A total of 60 test block were prepared for each test (surface hardness, dimensional accuracy, reproduction of details and surface porosity).the samples were divided into three groups (20 for each type of stone) type (III, IV, IV extra hard); SOLO and Sodium hypochlorite disinfectant by 2 methods (immersion and spray) were used in each test. Results: the results of dimensional accuracy, reproduction of details, surface hardness and surface porosity revealed no significant difference for all types of tested stone samples after immersion or spraying in SOLO and NaOCl except the surface hardness of type IV extra hard showed significant difference after spray with SOLO and the surface porosity of type IV extra hard showed significant difference after immersed in both SOLO and NaOCl solutions. Conclusions: Based on the results of this study immersion in and spray by using SOLO and NaOCl disinfectant solutions produced no adverse effect on dimensional accuracy, reproduction of details, surface hardness and surface porosity for type III, type IV dental stone and for type IV extra hard dental stone except for the surface hardness for type IV extra hard when sprayed with SOLO and the surface porosity when type IV extra hard stone immersed in the SOLO and NaOCl solutions.
In this work, measurements of activity concentration of naturally occurring radioactive materials (NORM) isotopes and their related hazard indices for several materials such as crude oil, sludge and water in Ahdeb oil fields in Waste governorate using high pure germanium coaxial detection technique. The average values for crude oil samples were174.72Bq/l, 43.46Bq/l, 355.07Bq/l, 264.21Bq/l, 122.52nGy/h, 0.7138, 1.1861, 0.601 mSv/y, 0.1503mSv/y and 1.8361 for Ra-226, Ac-228, K-40, Ra eq, D, H-external and H-internal respectively. According to the results; the ratio between 238U to 232Th was 4, which represents the natural ratio in the crust earth; therefore, one can be strongly suggested that the geo-stricture of the
... Show MoreData <span>transmission in orthogonal frequency division multiplexing (OFDM) system needs source and channel coding, the transmitted data suffers from the bad effect of large peak to average power ratio (PAPR). Source code and channel codes can be joined using different joined codes. Variable length error correcting code (VLEC) is one of these joined codes. VLEC is used in mat lab simulation for image transmission in OFDM system, different VLEC code length is used and compared to find that the PAPR decreased with increasing the code length. Several techniques are used and compared for PAPR reduction. The PAPR of OFDM signal is measured for image coding with VLEC and compared with image coded by Huffman source coding and Bose-
... Show MoreNew trends in teaching and learning theory are considered a theoretical axis
from which came the background that depends on any source, or practice sample or
teaching plane, accuracy and simplicity prevent the development of the teaching
process. Many attempts have come to scene to illuminate the teaching background,
but they have not exceed those remarkable patterns and methods. Thus, the
appearance of the teaching theory have been hindered.
This led to the need for research and development in the field of teaching to
find out a specific teaching theory according to the modern trends and concepts.
Teaching is regarded a humanitarian process which aims at helping those who
want to acquire knowledge, since teach
The research is a special case of semantics modern Iraqi art, especially with regard to the art of sculpture, and the exact Nasba sculpture, has included research, four chapters on whale1. The first chapter: which consisted of:A. The research problem.B. The importance of research.C. Find goal.H. Find borders.Kh. Determine the terms.2. Chapter II: The theoretical framework: which consisted ofA. The first topic: sculptured configuration.B. The second topic:1. The first axis: contemporary Iraqi sculpture.2. The second axis: the sculptor Jawad Salim.3. The third axis: Mohammed sculptor debateC. Theoretical framework indicators.D. Previous studies.3. Chapter III: proceedings: which included:A. Find community.B. The research sample.C. Research
... Show MoreThe complexation between folic acid and a typical polyaromatic hydrocarbon, fluorene, was investigated using FTIR and UV spectra. Appearance of a new IR band at 2401cm−1 demonstrates that NH2–C=N moiety on pterin ring in folic acid is protonated when fluorene is introduced. The emergence of two charge transfer bands at 217 nm and 278 nm in UV difference spectra shows the presence of π-π complexation between folic acid and fluorene. These experiments confirm that fluorene could combine with the pterin ring of folic acid through π-π donor–acceptor interaction and induce the protonation process in folic acid upon strengthening electron accepting ability of pterin ring. The results suggest that complexatio
... Show MoreConstruction contractors usually undertake multiple construction projects simultaneously. Such a situation involves sharing different types of resources, including monetary, equipment, and manpower, which may become a major challenge in many cases. In this study, the financial aspects of working on multiple projects at a time are addressed and investigated. The study considers dealing with financial shortages by proposing a multi-project scheduling optimization model for profit maximization, while minimizing the total project duration. Optimization genetic algorithm and finance-based scheduling are used to produce feasible schedules that balance the finance of activities at any time w
Countries are developing the spatial development of their societies through the projects that they undertake in various ways, and this development may be cause great impact on the environment, which also depend on the type of development, whether industrial, agricultural, or service and after the problems that occurred as a result of development on the environment, most of the countries currently did to legislating laws Environmental and some other procedures before granting environmental approvals for the purpose of establishing spatial development projects. One of the most important of these laws and regulations is Environmental impact assessment (EIA). The environmental impact asse
Perchloroethylene (PERC) is commonly used as a dry-cleaning solvent, it is attributed to many deleterious effects in the biological system. The study aimed to investigate the harmful effect associated with PERC exposure among dry-cleaning workers. The study was carried out on 58 adults in two groups. PERC-exposed group; include thirty-two male dry-cleaning workers using PERC as a dry-cleaning solvent and twenty-six healthy non-exposed subjects. History of PERC exposure, use of personal protection equipment (PPE), safety measurement of the exposed group was recorded. Blood sample was taken from each participant for measurement of hematological markers, liver and kidney function tests. The results showed that 28.1% of the workers were usin
... Show MoreThe undetected error probability is an important measure to assess the communication reliability provided by any error coding scheme. Two error coding schemes namely, Joint crosstalk avoidance and Triple Error Correction (JTEC) and JTEC with Simultaneous Quadruple Error Detection (JTEC-SQED), provide both crosstalk reduction and multi-bit error correction/detection features. The available undetected error probability model yields an upper bound value which does not give accurate estimation on the reliability provided. This paper presents an improved mathematical model to estimate the undetected error probability of these two joint coding schemes. According to the decoding algorithm the errors are classified into patterns and their decoding
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