Background: Contact between implant material and bones must be strong and fast creation, to fulfill these properties appropriate surface modifications must apply on used implants. In this contribution; double surface modifications are applied on Ti-6Al-4V alloy to accelerate osseointegration. Materials and methods: Anodic process is utilized to create titania nanotubes (TNTs) on the screws made from Ti-6Al-4V alloy. These implants were coated with nano ZrO2 particles. Second modification was annealing anodized screws at 8000C, and implanted in tibiae of nine adult New Zealand white rabbits. Results: Physical and histological consequences of two surface modifications on Ti-6Al-4V alloy screws were studied. Scanning electron microscope (SEM) images shows inhomogeneous distribution of TNTs on screws surfaces. X-ray diffraction (XRD) patterns illustrate the covering of first group samples with ZrO2 and transformation of Ti to its oxide (Rutile phase) for second group. These pattern shows that TiO2 had higher crystallinity and larger grain size than ZrO2. Atomic Force Microscopy images (AFM) shows the increasing of roughness, grain size and internal diameter of TNTs after annealing process. Coated implant with ZrO2 at 4 month duration shows threads with newly Haversian canal feature. Annealed implant at same duration shows well developed threads, base of implant illustrates bone trabeculae filled the base of implant bed with active osteoblast cells. Conclusion: Modification of implant's surface produced an improvement of osseointegration in comparison to untreated one.
Background: Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by bilateral stenosis starting at the supraclinoid internal carotid artery (ICA), with the development of a collateral network of vessels. It is an established cause of stroke in the pediatric age group. Despite its increasing prevalence in various parts of the world, it remains largely underrecognized in the Middle East, particularly in Iraq. This is the first case of MMD in an Iraqi patient undergoing surgery. Case description: A 12-year-old boy presents with a 3-months history of progressive behavioural changes. MRI revealed diffuse infarcts of different ages. MRA and CT angiography revealed extensive asymmetrical steno-occlusive changes of t
... Show MoreRealizing robust interconnectivity in a rapidly changing network topology is a challenging issue. This problem is escalating with the existence of constrained devices in a vehicular environment. Several standards have been developed to support reliable communication between vehicular nodes as the IEEE 1609 WAVE stack. Mitigating the impact of security/mobility protocols on limited capability nodes is a crucial aspect. This paper examines the burden of maintaining authenticity service that associated with each handover process in a vehicular network. Accordingly, a network virtualization-based infrastructure is proposed which tackles the overhead of IEEE 1906 WAVE standard on constrained devices existed in vehicular network. The virtualized
... Show MoreIn this paper, a new class of nonconvex sets and functions called strongly -convex sets and strongly -convex functions are introduced. This class is considered as a natural extension of strongly -convex sets and functions introduced in the literature. Some basic and differentiability properties related to strongly -convex functions are discussed. As an application to optimization problems, some optimality properties of constrained optimization problems are proved. In these optimization problems, either the objective function or the inequality constraints functions are strongly -convex.
Let be a ring. Given two positive integers and , an module is said to be -presented, if there is an exact sequence of -modules with is -generated. A submodule of a right -module is said to be -pure in , if for every -Presented left -module the canonical map is a monomorphism. An -module has the -pure intersection property if the intersection of any two -pure submodules is again -pure. In this paper we give some characterizations, theorems and properties of modules with the -pure intersection property.
Crop yield prediction is a critical measurement, especially in the time when parts of the world are suffering from farming issues. Yield forecasting gives an alert regarding economic trading, food production monitoring, and global food security. This research was conducted to investigate whether active optical sensors could be utilized for potato (Solanum tuberosum L.) yield prediction at the mid.le of the growing season. Three potato cultivars (Russet Burbank, Superior, and Shepody) were planted and six rates of N (0, 56, 112, 168, 224, and 280 kg ha−1), ammonium sulfate, which was replaced by ammonium nitrate in the 2nd year, were applied on 11 sites in a randomized complete block design, with four replications. Normalized difference ve
... Show MoreIn this work we reported the synchronization delay in
semiconductor laser (SL) networks. The unidirectional
configurations between successive oscillators and the correlation
between them are achieved. The coupling strength is a control
parameter so when we increase coupling strength the dynamic of the
system has been change. In addition the time required to synchronize
network components (delay of synchronization) has been studied as
well. The synchronization delay has been increased by mean of
increasing the number of oscillators. Finally, explanation of the time
required to synchronize oscillators in the network at different
coupling strengths.
This research considers a proposed mechanism relying on frictional interactions between the grasped object and the gripper, thus attaining a case of self-locking condition for a tendon type robotic gripper. A mathematical model was derived for this proposed mechanism, upon which a special purpose apparatus was fabricated and tested. Both results, theoretically and experimentally, are in good agreement, showing that the weight of the grasped object played a major role in attaining the self-locking condition.
Plentiful of healthcare practice is based on a disease/treatment approach rather than a prevention one. That is, the predominant focus is on treating existing symptoms and conditions that bring the patient to healthcare setting. There is no doubt about the significance of this approach for acute conditions, but there is some question whether this is the most efficient and effective way of distributing healthcare for increasing number of diseases and limited resources.
The evidences from everywhere have showed the profound cost benefit of prevention in healthcare practice. Healthy community, therefore, is the ultimate aim in any health services planning. The priority of care giver is shifted now to promote health and prevent
... Show More