Background: with the advent of new postmaterial in dentistry, it has become important to measure fitness of post restoration along the horizontal plane of the root space.This study aimed to measure and compare, the cement film thickness of conventional zinc phosphate cement in micrometer between the post and root dentin along horizontal plane at different post space regions (coronal, middle and apical) of four types of posts, by using stereomicroscopy. Material and methods: Thirty-two extracted human maxillary canines, mandibular canines and maxillary central incisors (n=32) were instrumented with ProTaper system files (hand use) and obturated with gutta-percha for ProTaper and AH26® root canal sealer. After 24hrs of incubation at 37ºC, post space was prepared using FRC Postec® plus drills no.3 and ER Cera reamer size 70, creating 10 mm deep post space. The prepared samples were then randomly divided into four main groups (8 samples each) according to the type of post used (Group A: fabricated cast metal post), (Group B: fabricated zirconia post), (Group C: prefabricated glass fiber reinforced composite post), (Group D: prefabricated zirconia post). After cementation and incubation period of 24hrs, each root was sectioned horizontally into 3 discs (2mm in thickness) at the coronal, middle and apical regions of the root space. The cement thickness between post and root dentine was measured (in µm) by using a stereomicroscope. Results: The results of this study showed that the lowest mean of cement thickness was in group C (35.28?m), followed by group A (78.12?m) and group D (81.9?m), and all three groups demonstrated acceptable cement thickness, while group B produced unacceptable cement thickness (127.34?m). One way ANOVA test revealed a statistically highly significant difference for the cement thickness among four post types used within each region of the root. Conclusions: the root region and type of post system have an effect on cement thickness along post space.
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In all process industries, the process variables like flow, pressure, level, concentration
and temperature are the main parameters that need to be controlled in both set point
and load changes.
A control system of propylene glycol production in a non isothermal (CSTR) was
developed in this work where the dynamic and control system based on basic mass
and energy balance were carried out.
Inlet concentration and temperature are the two disturbances, while the inlet
volumetric flow rate and the coolant temperature are the two manipulations. The
objective is to maintain constant temperature and concentration within the CSTR.
A dynamic model for non isothermal CSTR is described by a first order plus dead
time (FO
The main objective of this research is to design and select a composite plate to be used in fabricating wing skins of light unman air vehicle (UAV). The mechanical properties, weight and cost are the basis criteria of this selection. The fiber volume fraction, fillers and type of fiber with three levels for each were considered to optimize the composite plate selection. Finite element method was used to investigate the stress distribution on the wing at cruise flight condition in addition to estimate the maximum stress. An experiments plan has been designed to get the data on the basis of Taguchi technique. The most effective parameters at the process to be find out by employing L9
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Objective: The study aims at evaluating the psychological support and discharge plan from the hospital provided by nurses for woman undergone hysterectomy.
Methodology: The study uses descriptive design and non-probability (convenient) sample which is consisted of (40) nurses from (8) teaching hospitals in the City of Baghdad within the maternity wards. The study is carried out from 11 November 2020 to 27 June 2021. A observational tool is developed to evaluate the psychological support and the discharge plan after surgery. Content validity and internal consistency reliability are determined through pilot study. Data are collected through the use of the questionnaire and data are analyzed through the use of descriptive and inferentia
In order to evaluate the performance of introduced varieties of maize and test them under different levels of plant density, and to determine which of the introduced varieties give a high yield and at what plant density, a field experiment was carried out at Station A in the Department of Field Crops- College of Agricultural Engineering Sciences - University of Baghdad- Jadiriyah, for the fall season 2021, the RCBD design was used with four replications, in a split plot arrangement, the three plant densities (50.000, 70.000, and 90.000 Plant s ha-1) were the main plates, while the varieties represented the secondary factor, which is six varieties of maize, class 2 = 5783 DKC, Class 3 = 6315 DKC, Class 4= 6590 DKC, whic
... Show MoreThe aim of this investigation is to study the rote of alkaline phosphatase in mammogenesis and lactogenesis. A total of fortyfemalealbino rats were used and divided according to their physiological states into four groups [ten rats each]. From each deeply ether anesthetized rat, the mammary gland was removed, fixed, quenched in liquid nitrogen and sectioned using SLEE cryostat. The sections were employed for routine haematoxylin and eosin stain and alkaline phosphatase demonstration using the calcium–cobalt method. The obvious finding in the mammary glands of pregnant rat was the presence of thick black rings indicating strong alkaline phosphatase activityaround the basal part of the secretory epithelium of the alveoli. In lactating mamma
... Show MorePurpose: Studying the activity of acid phosphatase, which is the marker of lysosomal activity in the mammary glands of rats at different stages of the physiological maturation [virgih, pregnancy, lactation and Post lactation] Methods: Forty, female, albino rats were used in this study. They were divided into four groups according to their physiological states [virgin, pregnancy, lactation and post lactation]. The mammary glands, after suitable fixation and sectioning, were employed for routine haematoxylin and eosin stain and for acid phosphatase demonstration Results: Acid phosphatase activity was weakly diffuse in the secretory tubules of virgin rats, the diffuse and granular activity of this enzyme was increased during pregnancy in the s
... Show MoreThis paper reports test results and describes a numerical investigation of the effectiveness of using carbon fibre reinforced polymer (CFRP) fabrics for strengthening concrete cylinders that have been undamaged and damaged due to heating under preload. The purpose of this research was to investigate whether there is any difference in the performance of CFRP-wrapped cylinders if the wrapping is done under preload, and those for which neither heating, cooling nor wrapping was done under preload. The cylinders were exposed to 30% of maximum load at ambient temperature during heating and cooling before being wrapped under preload. Of 18 Ø 100 × 200 mm identical cylinders, 6 were left as control samples without heating, 12 were exposed t
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