Objective: This study evaluated the effect of immediate dentin sealing on the marginal adaptation of lithium disilicate overlays with three different types of resin-luting agents: preheated composite, dual-cure adhesive resin, and flowable composite. Materials and Methods: Forty-eight maxillary first premolars of similar size were prepared with a butt joint preparation design. The teeth were separated into two primary groups, each with twenty-four teeth: Group DDS: Delay dentin sealing (non-IDS) teeth were not treated. Group IDS: dentin sealing was applied immediately after teeth preparation. Each group was subsequently separated into three separate subgroups. Subgroups (DDS+Phc, IDS+Phc): cemented with preheated composite (Enamel plus HRi, Micerium, Italy), Subgroups (DDS+Dcrs, IDS+Dcrs): cemented with dual-cured resin cement (RelyX Ultimate, 3M ESPE, Germany) and Subgroups (DDS+Fc, IDS+Fc): Cemented with flowable composite (Filtek supreme flowable, 3M ESPE, USA). Using a digital microscope with a magnification of 230x, the marginal gap was measured before and after cementation at four different locations from each surface of the tooth, and the mean of measurements was calculated and analyzed statistically using the independent t-test, one-way ANOVA test, Bonferroni correction at a significance level of 0.05. Results: The samples that were immediately sealed with dentin bonding agent showed lower marginal gaps than delayed dentin sealing, both pre-and post-cementation for all subgroups, with a statistically significant difference (p < 0.01). The marginal gap was significantly lower in the IDS+Fc (48.888 ± 5.5 micro m) followed by the IDS+Dcrs group (53.612 ±5.8 micro m) and IDS+Phc (79.19 9±6.9 micro m) respectively, while the largest marginal gaps were observed in the DDS+Phc group (86.505 ± 5.4 micro m). Conclusion: Generally, the teeth with IDS showed better marginal adaptation than teeth without IDS. The marginal gap was smaller with flowable composite and dual-cure resin cement than with preheated composite.
Bioethanol produced from lignocellulose feedstock is a renewable substitute to declining fossil fuels. Pretreatment using ultrasound assisted alkaline was investigated to enhance the enzyme digestibility of waste paper. The pretreatment was conducted over a wide range of conditions including waste paper concentrations of 1-5%, reaction time of 10-30 min and temperatures of 30-70°C. The optimum conditions were 4 % substrate loading with 25 min treatment time at 60°C where maximum reducing sugar obtained was 1.89 g/L. Hydrolysis process was conducted with a crude cellulolytic enzymes produced by Cellulomonas uda (PTCC 1259).The maximum amount of sugar released and hydrolysis efficiency were 20.92 g/L and 78.4 %, respectively. Sugars
... Show MoreOften phenomena suffer from disturbances in their data as well as the difficulty of formulation, especially with a lack of clarity in the response, or the large number of essential differences plaguing the experimental units that have been taking this data from them. Thus emerged the need to include an estimation method implicit rating of these experimental units using the method of discrimination or create blocks for each item of these experimental units in the hope of controlling their responses and make it more homogeneous. Because of the development in the field of computers and taking the principle of the integration of sciences it has been found that modern algorithms used in the field of Computer Science genetic algorithm or ant colo
... Show MoreHyperpigmentation is the increase in the natural color of the skin. The purpose of this study is to evaluate the efficacy and safety of Q-Switched Nd:YAG (1064 & 532 nm) Laser in treatment of skin hyper pigmentation. This study was done in the research clinic of Institute of laser for postgraduate Studies/University of Baghdad from October 2008 to the end of January 2009. After clinical assessment of skin hyperpigmentation color, twenty six patients were divided according to their lesions. Eight Patients with freckles, seven patients with melasma, four patients with tattoo. Cases with tattoo, were subdivided into amateur tattoos two, professional tattoos one, and one traumatic tattoo. Four Patients with post inflammatory hyperpigment
... Show MoreThe ability of using aluminum filings which is locally solid waste was tested as a mono media in gravity rapid filter. The present study was conducted to evaluate the effect of variation of influent water turbidity (10, 20and 30 NTU); flow rate(30, 40, and 60 l/hr) and bed height (30and60)cm on the performance of aluminum filings filter media for 5 hours run time and compare it with the conventional sand filter. The results indicated that aluminum filings filter showed better performance than sand filter in the removal of turbidity and in the reduction of head loss. Results showed that the statistical model developed by the multiple linear regression was proved to be
valid, and it could be used to predict head loss in aluminum filings
Zigbee, which has the standard IEEE 802.15.4. It is advisable method to build wireless personal area network (WPAN) which demands a low power consumption that can be produced by Zigbee technique. Our paper gives measuring efficiency of Zigbee involving the Physical Layer (PL) and Media Access Control (MAC) sub-layer , which allow a simple interaction between the sensors. We model and simulate two different scenarios, in the first one, we tested the topological characteristics and performance of the IEEE802.15.4 standard in terms of throughput, node to node delay and figure of routers for three network layouts (Star, Mesh and Cluster Tree) using OPNET simulator. The second scenario investigates the self-healing feature on a mesh
... Show MoreAbstract
A two electrode immersion electrostatic lens used in the design
of an electron gun, with small aberration, has been designed using
the finite element method (FEM). By choosing the appropriate
geometrical shape of there electrodes the potential V(r,z) and the
axial potential distribution have been computed using the FEM to
solve Laplace's equation.
The trajectory of the electron beam and the optical properties of
this lens combination of electrodes have been computed under
different magnification conditions (Zero and infinite magnification
conditions) from studying the properties of the designed electron
gun can be supplied with Abeam current of 5.7*10-6 A , electron
gun with half acceptance
Toxoplasmosis is a widespread infection of great importance, and that the disease does not show any clinical specific signs . this study was performed on 200 patients with schizophrenia were collected from :Al-Rashad Teaching Hospitals and 100 healthy individuals, considered as control group, the samples were collected during the period of December 2012 until the end of February, 2013. Antibodies against T. gondii parasite in the serum were detected by using latex agglutination test (LAT) and showed a percentage of positive antibodies in schizophrenic patients and healthy individuals (control) 143(71.5%) and 45( 45%) respectively.While using Enzyme Linked Immunosorbent Assay (ELISA) the positive blood sera in LAT test of the schizophreni
... Show MoreThe -multiple mixing ratios of γ-transitions from levels of populated in the are calculated in the present work by using the a2-ratio methods. We used the experimental coefficient (a2) for two γ-transitions from the same initial state, the statistical tensor, which is related to the a2-coefficient would be the same for the two transitions. This method was used in a previous work for pure transitions or which can be considered pure. In these cases the multiple mixing ratios for the second transition ( ) equal zero, but in our work we applied this method for mixed γ-transitions and then the multiple mixing ratio ( ) is known for one transition. Then we calculate the ( ) value and versareversa. The weight average of the -values calcu
... Show MoreThe finishing operation of the electrochemical finishing technology (ECF) for tube of steel was investigated In this study. Experimental procedures included qualitative
and quantitative analyses for surface roughness and material removal. Qualitative analyses utilized finishing optimization of a specific specimen in various design and operating conditions; value of gap from 0.2 to 10mm, flow rate of electrolytes from 5 to 15liter/min, finishing time from 1 to 4min and the applied voltage from 6 to 12v, to find out the value of surface roughness and material removal at each electrochemical state. From the measured material removal for each process state was used to verify the relationship with finishing time of work piece. Electrochemi