Background: To investigate the effect of different types of storage media on enamel surface microstructure of avulsed teeth by using atomic force microscope.Materials and methods : Twelve teeth blocks from freshly extracted premolars for orthodontic treatment were selected . The study samples were divided into three groups according to type of storage media :A-egg white , B- probiotic yogurt , and C-bovine milk . All the samples were examined for changes in surface roughness and surface granularity distribution using atomic force microscope, at two periods: baseline, and after 8 hours of immersing in the three types of storage media. Results: Milk group had showed a significant increase in the mean of the roughness values at the test period, while the egg white and the probiotic yogurt groups showed decrease in the surface roughness at the test period. No significant changes was found in the grain size of enamel surface of the avulsed tooth in any types of three storage media at eight hours interval. The use of egg white and probiotic yogurt to store the samples may be beneficial in that they contain various ions and proteins that fill up enamel valleys, while the longer periods of milk exposure encourage the bacteria to continue fermenting lactose, resulting in continual acid generation and increased demineralization. Conclusion : Milk group demonstrated the highest roughness values, while the egg white group demonstrated the lowest roughness values of the teeth. No significant changes in the grain size of enamel surface of the tested teeth in any types of three storage media at eight hours interval .
Background: This study aimed to compare the surface microhardness (MH) and mineral content of white spot lesions(WSLs) after using bioactive glass (BAG)casein phosphopep-tides-amorphous calcium phosphate(CPP-ACP),and nanohydroxyapatite(Nano-HAP) under pHcycling. Material and method:18 sound maxillary first premolar were used for the study.10 were selected for the vickers microhardness test, For Energy-dispersive X-ray spectroscopy analysis (EDX), the remaining 8 premolar teeth were used, 40 sections of enamel blocks (Four from each tooth) were produced from the middle part of the buccal and palatal surfaces of teeth for MH test while 48 sections of enamel blocks (Six from each tooth) were produced for EDX analysis. Enamel slabs were
... Show MoreMost reinforced concrete (RC) structures are constructed with square/rectangular columns. The cross-section size of these types of columns is much larger than the thickness of their partitions. Therefore, parts of these columns are protruded out of the partitions. The emergence of columns edges out of the walls has some disadvantages. This limitation is difficult to be overcome with square or rectangular columns. To solve this problem, new types of RC columns called specially shaped reinforced concrete (SSRC) columns have been used as hidden columns. Besides, the use of SSRC columns provides many structural and architectural advantages as compared with rectangular columns. Therefore, this study was conducted to explain the structura
... Show MoreThe current research illustrates experimentally the effect of series and parallel connection (Z-I Configurations) of flat plate water solar collectors array on the thermal performance of closed loop solar heating system. The study includes the effect of changing the water flow rate on the thermal efficiency. The results show that, the collector's efficiency in series connection is higher than the parallel connection within flow rate level less than (100) ℓ/hr. Moreover, the collector efficiency in parallel connection of (I-Configurations) is more than the (Z- Configurations) with increasing the water flow rate .The maximum daily efficiency for parallel (I-Configurations) and (Z- Configurations) are (55%) and (51%) at w
... Show MoreAbstract
The objective of this research is to analyze the relationship between the strategic planning for human resources and career path, and I have tested Search the Ministry of Health and some health centers headquarters in the Karkh district, that is applied in sample Consist of (45) Deputy Director, Head of Depts, Departmental Manager, and health center Manager.
Find interested in studying the two subjects are important and vital, at the level of organizations at the present time, namely the strategic planning of human resources and career path. To achieve the objectives of the research was designed Qusestionnair (31) items to collect Primary data. and collected t
... Show MoreThe present research was conducted to synthesis Y-Zeolite by sol-gel technique using MWCNT (multiwalled carbon nanotubes) as crystallization medium to get a narrow range of particle size distribution with small average size compared with ordinary methods. The phase pattern, chemical structure, particle size, and surface area were detected by XRD, FTIR, BET and AFM, respectively. Results shown that the average size of Zeolite with and without using MWCNT were (92.39) nm and (55.17) nm respectively .Particle size range reduced from (150-55) nm to (130-30) nm. The surface area enhanced to be (558) m2/g with slightly large pore volume (0.231) km3/g was obtained. Meanwhile, degree of crystallization decrease
... Show MoreThe aim of this study is to estimate the parameters and reliability function for kumaraswamy distribution of this two positive parameter (a,b > 0), which is a continuous probability that has many characterstics with the beta distribution with extra advantages.
The shape of the function for this distribution and the most important characterstics are explained and estimated the two parameter (a,b) and the reliability function for this distribution by using the maximum likelihood method (MLE) and Bayes methods. simulation experiments are conducts to explain the behaviour of the estimation methods for different sizes depending on the mean squared error criterion the results show that the Bayes is bet
... Show MoreIn this paper, some Bayes estimators of the reliability function of Gompertz distribution have been derived based on generalized weighted loss function. In order to get a best understanding of the behaviour of Bayesian estimators, a non-informative prior as well as an informative prior represented by exponential distribution is considered. Monte-Carlo simulation have been employed to compare the performance of different estimates for the reliability function of Gompertz distribution based on Integrated mean squared errors. It was found that Bayes estimators with exponential prior information under the generalized weighted loss function were generally better than the estimators based o
The factorial analysis method consider a advanced statistical way concern in different ways like physical education field and the purpose to analyze the results that we want to test it or measure or for knowing the dimensions of some correlations between common variables that formed the phenomenon in less number of factors that effect on explanation , so we must depend use the self consistent that achieved for reaching that basic request. The goal of this search that depending on techntion of self consistent degree guessing for choosing perfect way from different methods for (orthogonal & oblique) kinds in physical education factor studies and we select some of references for ( master & doctoral) and also the scientific magazine and confere
... Show Moredifferent ?? ? injury ? This study aims to knowing the affect of embargo on cancer tutors in Iraq according to different body systems , In addition, this '?0 kinds study aims at knowing t^e categories ages that can be mostly injured by the cancer Egression analysis and descriptive statistics( median and frequency tables). ^?^???? have been used to achieve these two aims .This study includes ah the seventy cancer s Iraq from 1980-1998 and the data have been from the Ministry of Health / ?? tumors Iraqicancer board administration / central registry. The results of this study are emale productive? : Embargo has affected the ten different body systems as .? central nervous system and opthamamology , Hematology ,Respiratory ? system system , mal
... Show MoreCO2 geo-storage efficiency is strongly influenced by the wettability of the CO2-brine-mineral system. With decreasing water-wetness, both, structural and residual trapping capacities are substantially reduced. This constitutes a serious limitation for CO2 storage particularly in oil-wet formations (which are CO2-wet). To overcome this, we treated CO2-wet calcite surfaces with nanofluids (nanoparticles dispersed in base fluid) and found that the systems turned strongly water-wet state, indicating a significant wettability alteration and thus a drastic improvement in storage potential. We thus conclude that CO2 storage capacity can be significantly enhanced by nanofluid priming.