Abstract: The use of indirect, all-ceramic restorations has grown in popularity among dentists. Studies have demonstrated that for indirect ceramic restorations to be effective over time, cement and ceramic must be bonded in a stable manner. Chemical, mechanical, and laser irradiation are among the methods used to precondition ceramic surfaces in order to increase bond strength.The objective of the study: This study was performed to investigate the roughness values and surface topography of lithium disilicate glass-ceramic treated with conventional methods and different Er,Cr:YSGG, and fractional CO2 laser conditioning parameters.Material and methods: Sixty samples of lithium disilicate glass-ceramic were divided as follows: 1- (n = 10) untreated; 2- (n = 10) Hydrofluoric acid etched; 3- (n = 10) conditioned by Er,Cr: YSGG laser at (7 W, 25 Hz, 50/50% Water/Air, pulse duration 60 us, irradiation time 2 min); 4- (n = 10) conditioned by Er,Cr:YSGG laser at (5 W, 25 Hz, 50/50% Water/Air, pulse duration 60 us, irradiation time 2 min); 5- (n = 10) conditioned by fractional CO2 laser at (power 8 W, pulse duration 10 ms); 6- (n = 10) conditioned by fractional CO2 laser at (power 6 W, pulse duration 10 ms). Then evaluated by: Profilometer, and scanning electron microscopy.Results: The highest roughness values were found in CO2 laser power 8 W treated samples, followed by Er,Cr:YSGG laser power 7W treated samples. The hydrofluoric acid-etched samples showed roughness values comparable to those of CO2 laser-irradiated samples with a power of 6 W. The untreated sample showed the smoothest surface with the lowest roughness value.Conclusion: The application of Er,Cr:YSGG, fractional CO2 lasers enhances the surface roughness of lithium disilicate samples positively, showing the promised results of using these parameters in bonding procedures.
Corruption has become the subject of great interest, and the subject of research and scrutiny in recent years, because of its penetration in all fields of life, whether these fields are political, economic, social, and administrative. It is one of the biggest challenges and problems that are facing communities. Therefore, this study is focused on the evaluation of measures implementing the national strategy to combat corruption in Iraq.
This study was launched, first because of its intellectual dimensions to ensure a conceptual presentation of the strategy and operational management in general with a special focus on the processes of implementation and control str
... Show MoreThe research of three-based financial indicators to create value for shareholders, have been identified research problem in a number of the questions revolved around the extent to which it can express its based performance metrics to create value for the essence and the reality of the surveyed enterprises performance, Can the departments surveyed companies to choose the scale or the most harmonizing index and an expression of the actual performance of the company, has the goal of research is to diagnose the strengths and weaknesses in the performance of the surveyed enterprises through the use of a number of based on the concept of creating economic value and the search for the most suitable indicator to the reality of the perfor
... Show Moreنظرة عامة: تُعرَّف المادة أو العامل الذي يمكن أن يؤثر على الحمض النووي أو الكروموسومات على أنه سم جيني. قد يؤدي تلف الحمض النووي في الخلية الجسدية إلى حدوث طفرة جسدية ، والتي قد تحفز التحول الخبيث ، في حين أن الضرر الذي يلحق بالخلية الجرثومية قد يؤدي إلى تغيير خاصية وراثية (طفرة في السلالة الجرثومية) (سرطان). أحد الأحماض الدهنية الأحادية غير المشبعة الأحادية غير الأساسية هو حمض البالميتوليك. بعد حمض الأوليك
... Show MoreObjectives: The study involving 20 SARS CoV patients found that elevated microRNA levels, specifically miR-23a overexpression and miR-195-F1gene downregulation, could serve as potential diagnostic factors for COVID-19 infections, potentially aiding in early detection. Materials and Methods: 20 patients suffered from coronavirus (SARS CoV) (Patient group) and ten samples of healthy persons (control group). The blood sample was collected from the patients who attended Al-Zafaraniyah General Hospital, Fatima-Alzahra Hospital, and Al-Yarmook Teaching Hospital in Baghdad City. Nasopharyngeal and oropharyngeal swabs for each patient were taken simultaneously and added immediately into viral transport media (VTM). The microRNAs in the seru
... Show MoreEncryption of data is translating data to another shape or symbol which enables people only with an access to the secret key or a password that can read it. The data which are encrypted are generally referred to as cipher text, while data which are unencrypted are known plain text. Entropy can be used as a measure which gives the number of bits that are needed for coding the data of an image. As the values of pixel within an image are dispensed through further gray-levels, the entropy increases. The aim of this research is to compare between CAST-128 with proposed adaptive key and RSA encryption methods for video frames to determine the more accurate method with highest entropy. The first method is achieved by applying the "CAST-128" and
... Show MoreThispaperpresentsthesynthesisandstudyofsomenewmixed-liagnd complexescontainingtowaminoacids[Alanine(Ala)andphenylalanine(phe)]withsome metals .Theresultsproductswerefoundtobesolidcrystallinecomplexeswhichhave been characterized by using (FT-IR,UV-Vis) spectra , melting point, elemental analysis (C.H.N) , molar conductivity and solubiltyThe proposed structure of the complexes using program , chem office 3D(2000) .The general formula have been given for the prepared complexes :[M(A-H)(phe-H)]M(II): Hg , Mn ,Co , Ni , Cu ) , Zn , Cd(II) .Ala = Alanine acid = C3H7NO2Phe = phenylalanine = C9H11NO2
A low speed open circuit wind tunnel has been designed, manufactured and constructed at theMechanical Engineering Department at Baghdad University - College of Engineering. The work is one ofthe pioneer projects adapted by the R & D Office at the Iraqi MOHESR. The present paper describes thefirst part of the work; that is the design calculations, simulation and construction. It will be followed by asecond part that describes testing and calibration of the tunnel. The proposed wind tunnel has a testsection with cross sectional area of (0.7 x 0.7 m2) and length of (1.5 m). The maximum speed is about (70m/s) with empty test section. The contraction ratio is (8.16). Three screens are used to minimize flowdisturbances in the test sec
... Show MoreThis paper presents the synthesis and study of some new mixed-liagnd complexes containing tow amino acids[Alanine(Ala) and phenylalanine (phe)] with some metals . The results products were found to be solid crystalline complexes which have been characterized by using (FT-IR,UV-Vis) spectra , melting point, elemental analysis (C.H.N) , molar conductivity and solubilty The proposed structure of the complexes using program , chem office 3D(2000) . The general formula have been given for the prepared complexes : [M(A-H)(phe-H)] M(II): Hg , Mn ,Co , Ni , Cu ) , Zn , Cd(II) . Ala = Alanine acid = C3H7NO2 Phe = phenylalanine = C9H11NO2
A low speed open circuit wind tunnel has been designed, manufactured and constructed at the Mechanical Engineering Department at Baghdad University - College of Engineering. The work is one of the pioneer projects adapted by the R & D Office at the Iraqi MOHESR. The present paper describes the first part of the work; that is the design calculations, simulation and construction. It will be followed by a second part that describes testing and calibration of the tunnel. The proposed wind tunnel has a test section with cross sectional area of (0.7 x 0.7 m2) and length of (1.5 m). The maximum speed is about (70 m/s) with empty test section. The contraction ratio is (8.16). Three screens are used to minimize flow disturbances in the test section.
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The factor that keeps society from collapsing and regressing to chaos, violence, and lawbreaking is to stick to the human moral principles and criteria of moral behavior that prevent the spread of corruption and crime to the extent that law becomes devoid of activity and loss its dot errant power in front of chaos. The role of moral behavior is to motivate individuals to respect the general laws in dealing with others. Because of the dissemination of odd behavior patterns within our society, the social links are been badly affected and it's urgent for educational institutions to perform their duty in working on spreading awareness about moral values and avoid deviant directions and socially threatening t
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