Evaluation of efficient vehicular ad hoc networks based on a maximum distance routing algorithm

Traffic management at road intersections is a complex requirement that has been an important topic of research and discussion. Solutions have been primarily focused on using vehicular ad hoc networks (VANETs). Key issues in VANETs are high mobility, restriction of road setup, frequent topology variations, failed network links, and timely communication of data, which make the routing of packets to a particular destination problematic. To address these issues, a new dependable routing algorithm is proposed, which utilizes a wireless communication system between vehicles in urban vehicular networks. This routing is position-based, known as the maximum distance on-demand routing algorithm (MDORA). It aims to find an optimal route on a hop-by-hop basis based on the maximum distance toward the destination from the sender and sufficient communication lifetime, which guarantee the completion of the data transmission process. Moreover, communication overhead is minimized by finding the next hop and forwarding the packet directly to it without the need to discover the whole route first. A comparison is performed between MDORA and ad hoc on-demand distance vector (AODV) protocol in terms of throughput, packet delivery ratio, delay, and communication overhead. The outcome of the proposed algorithm is better than that of AODV

Enhancing the Optical Absorption and Interfacial Properties of BiVO4 with Ag3PO4 Nanoparticles for Efficient Water Splitting

Photoelectrochemical water splitting using semiconductor materials has emerged as a promising approach to produce hydrogen (H2) from renewable resources such as sunlight and water. In the present study, Ag3PO4 nanoparticles were electrodeposited on BiVO4 photoanodes for water splitting. A remarkable water oxidation photocurrent of 2.3 mA·cm–2 at 1.23 V versus reversible hydrogen electrode with ∼100% Faradaic efficiency was obtained, which constitutes a notable increase compared to the pristine BiVO4 photoanode. It is demonstrated that the enhancement of optical absorption (above-band gap absorbance) and the decrease of surface losses after the optimized deposition of Ag/Ag3PO4 nanoparticles are responsible for this notable performance. Remarkably, this heterostructure shows promising stability, demonstrating 25% decrease of photocurrent after 24 h continuous operation. This approach may open new avenues for technologically exploitable water oxidation photoanodes based on metal oxides

Prevalence, Clinical Features, and Radiological Features of Iraqi Patients with Ankylosing Spondylitis

Objective: To estimate  prevalence, clinical feature, radiological feature  of Iraqi patients with ankylosing spondylitis (AS) and  its  possible correlation with the disease activity and eye involvement.Patients and Method: A cross sectional study was conducted on 318 Iraqi patients with AS diagnosed according to the modified New York criteria. Clinical  evaluation (age , gender, symptom of AS, duration of the disease , presence of eye symptoms ,family history of AS, clinical assessment scoring of disease activity by bath ankylosing spondylitis disease activity Index  (BASDAI) as well as function by Bath ankylosing spondylitis functional index (BASFI) and radiological evaluation (Plain x-ray of sacroiliac joint , pelvic, dorso-lumbar spine and cervical spine as well as magnetic resonance imaging (MRI)   for  sacroiliac joint and spine were recorded for each patients, and  laboratory investigation (complete blood count , erythrocyte sedimentation rate(ESR) C-reactive protein (CRP), and human leucocyte antigen B 27 (HLA-B27) status were  tested using the standard serological method .Results: The prevalence rate of AS in the sample studied was 0.9 %, male was 90.6% with male to female ratio 9:1. The percentage of enthesiopathy   was 80.5% , axial arthritis was 68.2% and the peripheral arthritis was 13.8% . HLA-B27 was positive in 55%. Eye involvement was 23.6% and uveitis (all of the patients unilateral) 18.9%. There was significant association between eye manifestation with peripheral arthritis, high function class and severe disease activity but not with the sex, age, disease duration, family history of AS , HLA-B27 positive and extent  axial involvement  .Conclusions: Prevalence of AS in the sample studied was 0.9 % with male predominance, enthesiopathy was 80.5% , axial spondylitis 68.2%, peripheral arthritis 13.8%,  Eye involvement was 23.6%. .HLA-B27 was positive in 55%.There was significant association between eye manifestation with peripheral arthritis, high function class and severe disease activity. Keywords:-Iraq, Ankylosing spondylitis, Clinical feature, Radiological feature, HLA-B27

The planned sub-centres for riyadh city, a shift towards polycentric metropolitan development

Riyadh city, the capital of Saudi Arabia, will be transformed in the near future to a polycentric model which corresponds to the characteristic of modern cities. The city is now a monocentric, and its urban form was affected by the expansion of low-density residential areas. Riyadh has a population of just over four million inhabiting a developed land of nearly 1200 km2. The city was and will continue to be a focal point of attraction for migration, economic activities, and many key urban services. In February 2007, new regulations for the city new sub-centres were approved by the High Commission for the Development of Riyadh. This planned change for the city which is part of a polycentric metropolitan strategy tends to create new developments of sub-centres that could accommodate some key urban services outside the central business district as well as offering employment opportunities. This paper explores the reasons behind such changes, and the new regulations proposed for the planned sub-centres

Efficient and Stable Routing Algorithm Based on User Mobility and Node Density in Urban Vehicular Network

Vehicular ad hoc networks (VANETs) are considered an emerging technology in the industrial and educational fields. This technology is essential in the deployment of the intelligent transportation system, which is targeted to improve safety and efficiency of traffic. The implementation of VANETs can be effectively executed by transmitting data among vehicles with the use of multiple hops. However, the intrinsic characteristics of VANETs, such as its dynamic network topology and intermittent connectivity, limit data delivery. One particular challenge of this network is the possibility that the contributing node may only remain in the network for a limited time. Hence, to prevent data loss from that node, the information must reach the destination node via multi-hop routing techniques. An appropriate, efficient, and stable routing algorithm must be developed for various VANET applications to address the issues of dynamic topology and intermittent connectivity. Therefore, this paper proposes a novel routing algorithm called efficient and stable routing algorithm based on user mobility and node density (ESRA-MD). The proposed algorithm can adapt to significant changes that may occur in the urban vehicular environment. This algorithm works by selecting an optimal route on the basis of hop count and link duration for delivering data from source to destination, thereby satisfying various quality of service considerations. The validity of the proposed algorithm is investigated by its comparison with ARP-QD protocol, which works on the mechanism of optimal route finding in VANETs in urban environments. Simulation results reveal that the proposed ESRA-MD algorithm shows remarkable improvement in terms of delivery ratio, delivery delay, and communication overhead

Synthesis and Characterizations of Titanium Tungstosilicate and Tungstophosphate Mesoporous Materials

The work reports a development approach for the synthesis of novel multi-components mesoporous materials of titanium tungstate (meso-TiW) titanium tungstosilicate (meso-TiWSi) and tungstophosphate (meso-TiWP) mixed oxides that have high surface area and ordered mesoporous structures at nanometer length scale. Using the solvent evaporation-induced self-assembly (EISA) new oxides of bi- and tri-component of meso-TiW, meso-TiWSi and meso-TiWP oxides with different compositions and porosity were achieved. The physicochemical properties of the mesoporous oxides were characterized by X-ray diffraction, BET surface area analyzer, scanning, and transmission electron microscopes. Subject to the oxide composition, the obtained meso-TiW, meso-TiWSi and meso-TiWP exhibits high surface area, ordered 2D hexagonal mesostructured with order channels extended over a large area. The produced meso-TiW, meso-TiWSi, and meso-TiWP adsorbents exhibit good adsorption efficiency for the removal of Pb(II), Cd(II) and Hg(II) ions from water solution due to the presence of high surface area and accessibility of surface active sites. The adsorption efficiency of these mesoporous oxide reaches up to 95% and is found to be dependent contact time and adsorbents dose. The synthesis strategy is particularly advantageous for the production of new complex (multi-component) inorganic mesoporous materials that might have an application in the field of environmental, catalysis or energy storage and production

Registries in rheumatological and musculoskeletal conditions. Paediatric Behçet's disease: an international cohort study of 110 patients. One-year follow-up data

Objective. To set-up an international cohort of patients suspected with Behçet's disease (BD). The cohort is aimed at defining an algorithm for definition of the disease in children. Methods. International experts have defined the inclusion criteria as follows: recurrent oral aphthosis (ROA) plus one of following—genital ulceration, erythema nodosum, folliculitis, pustulous/acneiform lesions, positive pathergy test, uveitis, venous/arterial thrombosis and family history of BD. Onset of disease is <16 years, disease duration is ≤3 years, future follow-up duration is ≥4 years and informed consent is obtained. The expert committee has classified the included patients into: definite paediatric BD (PED-BD), probable PED-BD and no PED-BD. Statistical analysis is performed to compare the three groups of patients. Centres document their patients into a single database. Results. At January 2010, 110 patients (56 males/54 females) have been included. Mean age at first symptom: 8.1 years (median 8.2 years). At inclusion, 38% had only one symptom associated with ROA, 31% had two and 31% had three or more symptoms. A total of 106 first evaluations have been done. Seventeen patients underwent the first-year evaluation, and 36 had no new symptoms, 12 had one and 9 had two. Experts have examined 48 files and classified 30 as definite and 18 as probable. Twenty-six patients classified as definite fulfilled the International Study Group criteria. Seventeen patients classified as probable did not meet the international criteria. Conclusion. The expert committee has classified the majority of patients in the BD group although they presented with few symptoms independently of BD classification criteri