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Sept 5, 2022

A Comparative Study on the Ferrofluid Flow Models with Regards to the Behavior of A Ferrofluid Based Curved Rough Porous Circular Squeeze Film with Slip Velocity

This investigation plans to introduce a correlation among all the three magnetic fluid flow models (Neuringer-Rosensweig’s model, Shliomis’s model, Jenkins’s model) with regards to the conduct of a ferrofluid based curved rough porous circular squeeze film with slip velocity. The Beavers and Joseph's slip velocity has been invoked to assess the impact of slip velocity. Further, the stochastic model of Christensen and Tonder has been utilized to contemplate the impact of surface roughness. The load bearing capacity of the bearing system is found from the pressure distribution which is derived from the related stochastically averaged Reynolds type equation. The graphical portrayals guarantee that Shliomis model might be favoured for preparation of the bearing system with improved life period. However, for lower to moderate values of slip Neuringer-Rosensweig model might be considered. Morever, when the slip is at least the Jenkin's model might be deployed when the roughness is at reduced level.

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May 20, 2024

Integrative geography—Current issues in theory and practice (on the example of the Georgian geographical school)

The article discusses the essence of integrative geography and its importance for the theory and practice of geographical science. Such areas of integrative geography are characterized, the development of which will further increase the importance of applied geographical science. They include teaching about cultural landscape and historical landscape (part of landscape studies), geoecological expertise and environmental impact assessment (part of geographic ecology), geographic archeology and ecological culture (part of historical geography), landscape management and landscape services (part of landscape planning), and tourism—Assessment and planning of recreational resources (part of recreational geography).

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Feb 9, 2018

The Belt and Road Initiative: Maximizing benefits, managing risks—A computable general equilibrium approach

Using a Global Trade Analysis Project (GTAP) model, and China as the base for analytical comparison, this paper shows that there are significant economic benefits to China and the participating countries along all six Belt and Road Initiative (BRI) economic corridors. However, to maximize these benefits, the social and environmental risks need to be well managed. The analysis shows a clear sequencing in terms of priority corridors. Two corridors have minimal investments and immediate returns, two corridors have significant investments with huge returns, and two corridors have high investments with lower returns. Overall, the paper demonstrates that to ensure the sustainability of any BRI corridor development, there is a need to consider its costs and benefits from the economic, social and environmental perspectives.

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May 14, 2024

Assessing the rheological properties of bio modified asphalt cement

The production of asphalt cement binder in Iraq is conducted through the distillation of crude oil. The byproduct of such distillation is asphalt cement, which does not practice any further processing. Further processing of the binder is considered vital to controlling its physical properties and chemical composition. The implementation of bio-modifiers before using such asphalt cement binder for paving work is a sound practice to enhance its sustainability and reserve the required rheological properties. In the present study, the asphalt cement binder was modified by the implementation of extender oil (used diesel engine oil) and scrap tire rubber. The aim of this work is to improve and provide a sustainable and proper rheological quality of the binder for paving work. Various percentages of scrap tire rubber and extender oil have been tried to optimize the modifiers that can exhibit a suitable control on the required rheological properties of the asphalt binder, such as the stiffness modulus, its temperature susceptibility in terms of penetration index, and penetration viscosity number, and the temperature of the equivalent stiffness of the binder. The stiffness of asphalt cement binder was digested in hot, moderate, and cold environments. It was observed that the implementation of extender oil was able to reduce the penetration index (PI) by 36.3%, 54.5%, and 27.2% when 15%, 10%, and 5% of extender oil by weight of the mixture were added, respectively, to the control binder. The addition of scrap tire rubber to the binder-oil mixture was able to reduce the PI by up to 10% of the rubber content and exhibited further control over the temperature susceptibility of the binder. It can be revealed that the extender oil increases the negative values of penetration viscosity number (PVN), while the scrap tire rubber can improve the PVN of the binder. When a high percentage of extender oil (15%) is implemented, the stiffness of the binder declines by 50%, 90%, and 75% when the testing temperature changes from 4 to 25, and 60 ℃, respectively. It was concluded that the inclusion of 15% scrap tire rubber and 15% extender oil in the asphalt cement binder produced by Qayarah oil refinery is recommended to provide a sustainable binder for pavement, control its temperature susceptibility, and provide a binder that is less susceptible to pavement distress.

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Jan 22, 2008

Topographic evaluation of sacroiliac joints by magnetic resonance imaging in patients with axial spondyloarthritis

Objective: To evaluate the imaging features of spondyloarthritis on magnetic resonance imaging (MRI) of the sacroiliac (SI) joints in terms of topography (in thirds) and affected margin, since this aspect is rarely addressed in the literature. Methods: Cross-sectional study with MRI (1.5 T) evaluation of the SI in 16 patients with diagnosis of axial spondyloarthritis regarding the presence of acute (subchondral bone edema, enthesitis, synovitis and capsulitis) and chronic changes (erosions, subchondral bone sclerosis, bone bridging and fatty replacement), performed by two radiologists, blinded to clinical data. MRI findings were correlated with clinical data including age, disease duration, medications, HLA-B27, BASDAI, ASDAS-VHS and ASDAS-PCR, BASMI, BASFI, and mSASSS. Results: Bone edema pattern and erosions showed predominance in the upper third of SI (p = 0.050, p = 0.0014, respectively). There was a correlation between the time of disease and structural changes by affected third (p = 0.028-0.037), as well as the presence of bone bridges with BASMI (p = 0.028) and mSASSS (p = 0.014). Patients with osteitis of the lower third had higher ASDAS values (ESRV: p = 0.011 and CRP: p = 0.017). Conclusion: Chronic inflammatory changes and the pattern of bone edema predominated in the upper third of the SI, but there was also concomitant involvement of the middle or lower thirds of the joint. The localization of involvement in the upper third of the SI was insufficient to differentiate between degeneration and inflammation.