Background: The daily cleaning routine of the silicone maxillofacial prostheses by the patient may cause some alteration in the materials properties. The purpose of the present study was to investigate the effect of different disinfection procedures on some properties of silicon dioxide reinforced Cosmesil M511 HTV maxillofacial silicone. Materials and Methods: One hundred and sixty (160) specimens were prepared by mixing 5% SiO2 nano particles and 0.5% intrinsic cream color into the silicone polymer according to manufacturer's instructions. Specimens were divided into 4 groups according to the performed test (tear strength, surface hardness, surface roughness and color) with 40 specimens each. Each group was further subdivided according to the disinfection procedure conducted (control, microwave exposure, neutral soap and 4% chlorhexidine gluconate). Measurements for tear strength were done using universal testing machine. Surface hardness test was carried out with a Shore A Durometer. Surface roughness was analyzed with a portable digital Profilometer. Color change was established with a Spectrophotometer. After the initial testing, all specimens were submitted to disinfection procedure 3 times a week for 60 days. Measurements were repeated and data were statistically analyzed using one-way ANOVA followed by Fisher's LSD or Games-Howell test. Results: Spectrophotometer results showed non-significant decrease in the light absorbance of all experimental groups after disinfection, indicating a strong integration between the nano filler and the polymeric chains, which was not broken during the disinfection procedure. Highly-significant increase in Shore A hardness was recorded, while the decrease in surface roughness was highly significant in all experimental groups. Tear strength reduced significantly after disinfection in all experimental groups. Conclusion: Disinfection seemed to cause different amount of alteration in all of the tested properties of silicone. High color stability is expected in this type of maxillofacial silicone after disinfection.Although microwave exposure had increased the hardness of the material, it is considered a satisfactory disinfection procedure since it caused the least effect on the tear strength and surface roughness of the material. Therefore, microwave exposure is recommended for the disinfection of maxillofacial silicone prostheses.
Seeds of barley ( Hordeum vulgare L.) plant var. California Marriout were soaked in solutions of calcium sulphate and calcium chloride at different concentrations (0.5%,1.0%,5.0%) for different periods of time(3,6,12) h with continuous aeration . Seeds were planted in petridishs. Seedling of some treatment were transferred to the solution culture. The nutrient solution used was that of Arnon and Hoagland but at 1:10 strength. Different concentrations of NaCl were used in the nutrient solution (100,150, 200) m M . Unsoaked seeds and soaked in distilled water were used for comparison . Salt stress tolerance was evaluated by different morphological parameters. Results showed that the adverse effect of saline stress were reduced by so
... Show MoreThe present research includes the effect of different concentrations of NaCl on some biological aspects (longevity, growth and molting) of Acanthocyclops bicuspidatus (Copepoda; Cyclopoida). The results showed a decrease of longevity with the increase of salt concentrations. The lowest mean of male′s longevity was 6.8 day in the 2ppt concen. compared with the control treatment 34.2 day, The lowest mean of female′s longevity was 5.1 day in the 2ppt concen. compared with the control treatment 30.1 day. The mean growth for males was lower than the mean growth of females. In males the lowest m
... Show MoreThe effect of gamma rays on males and females ofCallasobruchus maculatus and Trogoderma granarium which were irradiated as 1-3 days old adults was investigated. The results revealed that the percent egg hatch for both pests was zero ,and average number of egg (34.2,21.5) for both pests respectively where their males where irradiated with 0.18 kGy and mated with unirradiated females. While the percent of egg hatch and the average number of egg (zero,21,3) respectively when the females where irradiated with 0.18 and 0.15 kGy and mated to unirradiated males for C. maculatus and T. granarium respectively. Furthermore, the results showed that the percent of eggs hatch and average number of egg was ( zero,22.7) for C. maculatus when both sexes i
... Show MoreThe experiment was carried out in the green house of, Biology Department of ,College of
Education , Ibn Al-Haitham , Baghdad University. For growth season 2008-2009 via planting
seeds of three genotypes of barley cultivars Baraka , Becson and Baraka x Forest ,to study the
effect of different concentrations of NaCl (o , 50 ,100 , 150 , 200 ) mM.L on some
growth parameters such as fresh and dry weight of shoot and elements plants the experiment
carried out by using completely randomized design applied with four replicates . Data were
statistically analyzed by using least significant differenceat0.05probabilitylevel.
The results showed that an increase in NaCl salt concentrations from 0 to 200mM.L
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Abstract The present work aims to study the performance of reinforced compacted clay soil by sand columns stabilized with sodium silicate to obtain more solid columns than the surrounding soil. The experimental work was carried out by using a lab model to evaluate the performance of both the floating and end bearing sand columns. The results showed that the improvement ratio for the soil reinforced with sand columns stabilized with sodium silicate reached 390% for the type of floating columns and 438% for end bearing columns.
Flame thermal spray technique has been used to produce a cermets composite coating based on powders of ceramic oxides (
AhOJ) reinforced by mineral powders as bonding material ( Ni - AI ) at different rates on Inconel substrates , after preparing it by grit blasting.
After completing the best parameters of coating such as distance of spraying , surface roughness and angle of spraying , the tests of porosity , hardness , microstructure and thermal cycling have been made.
The experimental results show that all properties of coating were effected after heat treatment. The best value of heat treatmen t is at (I 000°C) for (l.Shr) in which the &
... Show MoreIn this paper, we will introduce and study the concept of nano perfect mappings by using the definition of nano continuous mapping and nano closed mapping, study the relationship between them, and discuss them with many related theories and results. The k-space and its relationship with nano-perfect mapping are also defined.
Abstract. The purpose of this work is to introduce and investigate new concepts of mappings namely nano paracompactmappings, nano locally limited, nano h-locally limited and finally nano-perfect in nano topology by using nano-closed sets. As well as, the relation between these concepts of mappings have been study in nano topology. Additionally, the nano topology groups of the types and advances results which are introduces in this work are very vital. We also presented the type of nano Lindeloff mappings, and the relations of them was introduce and discussed with several characteristics related it. Nano morphism also introduce.
Abstract. Nano-continuous mappings have a wide range of applications in pure and applied sciences. This paper aims to study and investigate new types of mappings, namely nano-para-compact, completely nano-regular, nano-para-perfect, and countably nano-para-perfect mappings in nano-topological spaces using nano-open sets. We introduce several properties and basic characterizations related to these mappings, which are essential for proving our main results. Additionally, we discuss the relationships among these types of mappings in nano-topological spaces. We also introduce the concept of nano-Ti-mapping, where i = 0, 1, 2, nano-neighborhood separated, and nano-functionally separated, along with various other definitions. We explore the relat
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