Background: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time. The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundred sixty sapphire brackets. The brackets were divided according to bonding materials into three groups each group consist of one hundred twenty brackets, then each subgroup farther subdivided into four groups according to the material they were immersed (distilled water, black tea, Pepsi and cigarette smoke) with thirty brackets each, then Each group with ten brackets farther subdivided according to time interval of immersion in each media into three groups one day, seven days and fourteen days at 37°C in the incubator.A UV-Visible spectrophotometer (Shimadzu, UV -1800) was used to perform a light absorption test. Results: ANOVA and LSD post Hoc tests were used to identify the significant effects of the staining materials at a significance level P ≤ 0.05.It was found that the immersion time gradually influenced the color stability of the adhesive materials with sapphire brackets with the highest activity observed at fourteen days interval. The brackets bonded with Resilience light cure adhesive are the most type affected by staining materials, then followed by the brackets bonded with Transbond and finally the brackets bonded with Enlight light cure adhesive. For the staining materials it was found that the cigarette smoke is the most powerful staining material, followed by tea and finally pepsi. Conclusions: From the above result we can conclude that the type of adhesive must take in consideration when the esthetic brackets have been used.
Most tubes are made from butyl rubbers, but certain types, such as giant tubes, are based on natural rubber because very high green strength is required when handling the uncured compound. By using blends of natural rubber (NR) and brominated butyl rubber (BIIR), it is possible to maintain high green strength in the uncured compound and improve impermeability and heat resistance of the cured tube. The best formulations are obtained in the presence of 50 phr of (BIIR) to achieve desired mechanical properties. Improved impermeability was obtained by using 50 and 75 phr of (BIIR) rubber in compounds. Blending of brominated butyl rubber (BIIR) with natural rubber (NR) enhances air retention with acceptable sacrifices in green strength.
... Show MoreIn this paper, an adaptive polynomial compression technique is introduced of hard and soft thresholding of transformed residual image that efficiently exploited both the spatial and frequency domains, where the technique starts by applying the polynomial coding in the spatial domain and then followed by the frequency domain of discrete wavelet transform (DWT) that utilized to decompose the residual image of hard and soft thresholding base. The results showed the improvement of adaptive techniques compared to the traditional polynomial coding technique.
A principal problem of any internet user is the increasing number of spam, which became a great problem today. Therefore, spam filtering has become a research fo-cus that attracts the attention of several security researchers and practitioners. Spam filtering can be viewed as a two-class classification problem. To this end, this paper proposes a spam filtering approach based on Possibilistic c-Means (PCM) algorithm and weighted distance coined as (WFCM) that can efficiently distinguish between spam and legitimate email messages. The objective of the formulated fuzzy problem is to construct two fuzzy clusters: spam and email clusters. The weight assignment is set by information gain algorithm. Experimental results on spam based benchmark
... Show MoreImplementing smart community engagement should consider careful planning and collaboration with numerous stakeholders, including the community. The technology and program must be designed to frame its purpose and should link back to specific goals of implementing smart community engagement. Digital services do not guarantee a smart engagement between the community and the local government. This is the case for the Kubang Pasu local government where several online services have been provided in their attempt to implement the smart community concept. However, understanding on the preferences of features and requirements of existing web-based systems and the impact of these systems is lacking. Therefore, a perception study needs to be condu
... Show More
(2)
(1)
The rapid development of automation industries and technologies has shown incredible prospects for transforming our homes into a smart home automation system, which are more secure than a simple home. This paper proposes a home application based on voice and text called the Automated Control and Monitoring System (ASCM). This application can be utilized by both normal and vision-impaired people by using with a mobile phone.
The application allows users to send voice commands through Google Assistant installed on Android to control the appliances. They can also have complete monitoring by logging onto the ThingSpeak dashboard, which displays a device status indicator and sends alert messages in the event of dang
... Show More
(1)
(2)
This research aimed to examine the effect of concentration of dyes stuff, contact time, temperature and ratio of adsorbent weight in (gm) to volume of solution in (ml) on the percentage removal. Two dyes were used; direct blue 6 and direct yellow and the adsorbent was the maize cob. Batch experiments were performed by contacting different weights of adsorbent with 50 ml of solution of desired concentration with continuous stirring at various temperatures. The percentage of removal was calculated and the maximum percentage of removal was 80%. And as the concentration of solution, contact time, temperature and the ratio of adsorbent to volume of solution increase the percentage of removal increase.
Intelligent Transportation Systems (ITS) have been developed to improve the efficiency and safety of road transport by using new technologies for communication. Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) are a subset of ITS widely used to solve different issues associated with transportation in cities. Road traffic congestion is still the most significant problem that causes important economic and productivity damages, as well as increasing environmental effects. This paper introduces an early traffic congestion alert system in a vehicular network, using the internet of things (IoT) and fuzzy logic, for optimizing the traffic and increasing the flow. The proposed system detects critical driving conditions, or any emerge
... Show More
(7)
(6)
In this paper, the behavior of structural concrete linear bar members was studied using numerical model implemented in a computer program written in MATLAB. The numerical model is based on the modified version of the procedure developed by Oukaili. The model is based on real stress-strain diagrams of concrete and steel and their secant modulus of elasticity at different loading stages. The behavior presented by normal force-axial strain and bending moment-curvature relationships is studied by calculating the secant sectional stiffness of the member. Based on secant methods, this methodology can be easily implemented using an iterative procedure to solve non-linear equations. A comparison between numerical and experimental data, illustrated
... Show More
Background: Chronic hepatitis B virus (HBV) infection is a common health problem that has a worldwide distribution. Apart from the direct effect of the virus on the liver, there are many extrahepatic manifestations among which the probable effect on bone turnover associated with low bone mineral density (BMD). Objectives: This study aimed to determine the association between treated and untreated chronic HBV infection with BMD. Methods: This is a cross-sectional study which included a total of 48 patients with chronic HBV (28 patients treated with tenofovir-disoproxil-fumarate [TDF] antiviral drug and 20 patients have not yet started treatment). Other age- and sex-matched 30 apparently healthy individuals were recruited to represent the hea
... Show More
The apoptotic activity of methionine γ- lyase from Pseudomonas putida on cancer cell lines was indicated by measuring the concentration of cytochrome c in the supernatants of cell lines. The result revealed high concentration of cytochrome c in the supernatants of cancer cell lines (RD, AMGM and AMN3) respectively while the concentration of anti-apoptotic protein (Bcl-2) was very low.