Commercially pure titanium (cpTi) is widely used as dental implant material although it was found that titanium exhibited high modulus of elasticity and the lower corrosion tendency in oral environment. Niobium(Nb) was chosen for this study as an alternative to cpTi implant material due to its bioinert behavior and good elastic modulus and moderate cost in addition to corrosion resistance. This study was done to evaluate the effect of biomimetic coating on the surface properties of the commercially pure titanium and niobium implants by in vitro and in vivo experiments. The in vitro study was involved etching the samples of each material in HCl then soaking in 10M NaOH aqueous solution. These samples were then immersed in a 5 times concentrated simulated body fluid for 14 days. Scanning Electron Microscope, Energy Dispersive X-ray, and X-Ray Diffraction tests were done to analyze surface changes. The in vivo study was done by the implantation of screw-shaped implants (two from each material, uncoated and the other was biomimetically coated) in the tibias of New Zealand rabbits. After 2 and 4 weeks of healing period, 20 rabbits were sacrificed for each period. A removal torque was done for ten animals in each group, whereas the other ten were used for histological testing and histomorphometric analysis with optical microscope.The in vitro experiments showed that the use of 14 days immersion in a concentrated simulated body fluid produced a layer of calcium phosphate on metal surfaces. The removal torque values and new bone formation were increased significantly in Nb than Ti, in coated than uncoated screws, and in 4 weeks than 2 weeks healing periods. The Nb implants had better biomechanical and biological properties than the commercially pure titanium implants and can be used as an alternative dental implant.
ملخص البحث باللغة الإنجليزية
The concept of the phenomenon of nuns: an analytical ideological study
Dr. Samia bint Yassin Al-Badri
Department of Islamic Doctrine & Contemporary Ideologies
College of Shariʿah & Islamic Studies
Qassim University
The study of concepts is one of the main pillars of doctrinal studies, in order to understand the formation of the concept, and to understand its contexts in religious sources, in order to be systematically criticized; So, this research came with the title:
The concept of the phenomenon of nuns, an analytical doctrinal study
The study concluded with resu
... Show MoreAn experimental study is made here to investigate the discharge coefficient for contracted rectangular Sharp crested weirs. Three Models are used, each with different weir width to flume width ratios (0.333, 0.5, and 0.666). The experimental work is conducted in a standard flume with high-precision head and flow measuring devices. Results are used to find a dimensionless equation for the discharge coefficient variation with geometrical, flow, and fluid properties. These are the ratio of the total head to the weir height, the ratio of the contracted weir width to the flume width, the ratio of the total head to the contracted width, and Reynolds and Weber numbers. Results show that the relationship between the discharge co
... Show MoreAbstract
Electrical magnate was designed and constructed, the optimum Magnetic flux and the effect of time on the physical properties of the alkaline (magnetic water) produced from the bottled drinking water [the total dissolved solids (TDS) or the electrical conductivity, and pH] were studied, to simulate ZamZam water in Mekka Saudi Arabia. Also, the efficiency of magnetic field from this designed electrical magnate in decreasing the TDS of sea water (of 1500 ppm NaCl Content), to convert it to water suitable for irrigation (TDS<1000 ppm) was investigated in this work.The results show that the magnetic flux from our designed electrical magnate in the range of (0.013- 0.08) Tesla and 30 minut
... Show MoreGod urged to read the Holy Qur’an and to ponder it is commanded, and the Most High said: That they ponder over His verses and that those with insights remember ().
And this book that God Almighty sent down to the heart of His Prophet, peace and blessings be upon him, is as clear as the sun and the moon.
It is a book of guidance and the constitution of a nation that is the best nation brought forth for mankind, and God has taken care of its preservation as He said: We have sent down the Remembrance, and we are its guardians.
This has been chosen for this topic (Luqman's commandments to his son) for what we see today in our time and society from the loss of morals and values and the neglect of parents to their chi
Abstract
This research attempt to explain the essential aspects of one important model in management of Bank risks , that is (stress testing) , which increase the concentrate on it resulting the negative affects of Global financial crisis that it accuar in 2008 to study the application possibilities in iraqian banks to enhancing the safety and financial soundness Becuase the classical tools in Risk management don’t give clear image on Banks ability in facing risks, hence the Basel committee on Banking supervision focusing in agreement of Basel 2,3 on stress testing when it doing the internal capital adequacy assessment process (ICAAP) .
To achieving the reseach obje
... Show MoreThe 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
... Show MorePolymer additives binder system provides many properties useful in thermal energy storage (TES) then developed the efficient energy storage materials and green strength bodies system.
This paper studies the thermal energy storage property for polyvinyl alcohol (PVOH) / paraffin wax (WPw) blends. To enhance paraffin wax thermal conductivity, PVOH as a material which high conductivity was employed. A fixed weight of Paraffin wax was dispersed with PVOH heterogeneously at different additive weights ratios of PVOH/Pw (50/50, 67/33, 75/25, and 80/20) wt. ratio respectively. The composite material was prepared using wetted pressing method.
Both base materials (polyvinyl alcohol and paraffin wax) were scanned using differential
... Show MoreIt is often needed to have circuits that can display the decimal representation of a binary number and specifically in this paper on a 7-segment display. In this paper a circuit that can display the decimal equivalent of an n-bit binary number is designed and it’s behavior is described using Verilog Hardware Descriptive Language (HDL). This HDL program is then used to configure an FPGA to implement the designed circuit.
The study was carried out in order to evaluate clinically and laboratory cachectic animals suffering from anemia. Animal examined were 50 cow and calf. The study include clinical, hemato and biochemical test for accurate diagnosis of cachexia in cows and calves . Blood smears were conducted for detection of blood parasites , fecal examination for gastrointestinal parasites and Different parameters were applied for classification of cachexia , depending on bony projection specially ribs and pelvic and generalized muscular atrophy. However , The study revealed an incidence of cachexia and anemia of blood parasites was including Theileria, Anaplasma, gastrointestinal parasites, ten cases were shown foreign body syndrome while other tens wer
... Show MoreAfter its 35-year occupation of Japan and the US occupation, Korea has set its sights on a long-term goal of building its country and establishing its foundations, unobtrusive and unchecked by the problems and wars that have stood in the way of its goal, surpassing all odds and achieving the best results. The most powerful Asian and global economies, which gained the respect of the world and its appreciation of the experience has become referred to as boys