Geophysical investigations of a geothermal anomaly at Wadi Ghadir, eastern Egypt

During regional heat flow studies a geothermal anomaly was discovered approximately 2 km from the Red Sea coast at Wadi Ghadir, in the Red Sea Hills of Eastern Egypt. A temperature gradient of 55 C/km was measured in a 150 m drillhole at this location, indicating a heat flow of approximately 175 mw/sqm, approximately four times the regional background heat flow for Egypt. Gravity and magnetic data were collected along Wadi Ghadir, and combined with offshore gravity data, to investigate the source of the thermal anomaly. Magnetic anomalies in the profile do not coincide with the thermal anomaly, but were observed to correlate with outcrops of basic rocks. Other regional heat flow and gravity data indicate that the transition from continental to oceanic type lithosphere occurs close to the Red Sea margin, and that the regional thermal anomaly is possibly related to the formation of the Red Sea

Using negative velocity feedback controller to reduce the vibration of a suspended cable

The system of suspended cable with mixed excitation forces is controlled in this paper by using negative linear velocity feedback controller. The equations of motion of this system contain quadratic and cubic nonlinearities. The multiple scale perturbation technique is applied to determine the response of the nonlinear system near the simultaneous sub-harmonic and combined resonance case of this system. The stability of the obtained numerical solution is investigated using frequency response equations. The effect of different parameters on the vibrating system are investigated and reported

Optimising surface roughness and density in titanium fabrication via laser powder bed fusion

The Ti6Al4V alloy has many advantages, such as being lightweight, formal, and resistant to corrosion. This makes it highly desirable for various applications, especially in the aerospace industry. Laser Powder Bed Fusion (LPBF) is a technique that allows for the production of detailed and unique parts with great flexibility in design. However, there are challenges when it comes to achieving high-quality surfaces and porosity formation in the material, which limits the wider use of LPBF. To tackle these challenges, this study uses statistical techniques called Design of Experiments (DoE) and Analysis of Variance (ANOVA) to investigate and optimise the process parameters of LPBF for making Ti6Al4V components with improved density and surface finish. The parameters examined in this study are laser power, laser scan speed, and hatch space. The optimisation study results show that using specific laser settings, like a laser power of 175 W, a laser scan speed of 1914 mm/s, and a hatch space of 53 µm, produces Ti6Al4V parts with a high relative density of 99.54% and low top and side surface roughness of 2.6 µm and 4.3 µm, respectively. This promising outcome demonstrates the practicality of optimising Ti6Al4V and other metal materials for a wide range of applications, thereby overcoming existing limitations and further expanding the potential of LPBF while minimising inherent process issues

Homing and reparative effect of intra-articular injection of autologus mesenchymal stem cells in osteoarthritic animal model

<p>Abstract</p> <p>Background</p> <p>This work aimed to study the homing evidence and the reparative effect of mesenchymal stem cells (MSCs) in the healing process of induced osteoarthritis in experimental animal model (donkeys).</p> <p>Methods</p> <p>Twenty-seven donkeys were equally divided into 3 groups based on the observation period after induction of arthritis (3, 6 and 9 weeks) to achieve different degrees of osteoarthritis. Each group was subdivided into three subgroups of three animals each based on the follow-up period (1, 2 and 6 months) after treatment. The induction was done through intra-articular (IA) injection of 2 ml of Amphotericin-B in both carpal joints. MSCs were harvested in a separate procedure, labeled with green fluorescent protein (GFP) using monster GFP vector and suspended in hyaluronic acid for IA injection. Treatment approaches consisted of cell-treatment using MSCs suspended in 3 ml of hyaluronic acid (HA) for the right carpal joint; and using the same amount of (HA) but without MSCs for the left contralateral carpal joint to serve as a control. Animals were assessed clinically and radiologically before and after treatment. Synovial fluid was also evaluated. Histopathologically; articular cartilage structural changes, reduction of articular cartilage matrix staining, osteophyte formation, and subchondral bone plate thickening were graded. Data was summarized using median and percentile for scores of histopathologic grading. Comparison between groups was done using non-parametric Mann Whitney test.</p> <p>Results</p> <p>The reparative effect of MSCs was significant both clinically and radiologically in all treated groups (P < 0.05) compared to the control groups. Fluorescence microscopy of sections of the cell-treated joints of all animals indicated that the GFP-transduced injected cells have participated effectively in the reparative process of the damaged articular surface and have integrated within the existing articular cartilage. The cells were associated with the surface of the cartilage and, were also detected in the interior.</p> <p>Conclusions</p> <p>Homing was confirmed by the incorporation of injected GFP-labeled MSCs within the repaired newly formed cartilage. Significant recovery proves that the use of IA injection of autologous MSCs is a viable and a practical option for treating different degrees of osteoarthritis.</p

Hybrid finite element–smoothed particle hydrodynamics modelling for optimizing cutting parameters in CFRP composites

Carbon-fibre-reinforced plastic (CFRP) is increasingly being used in various applications including aerospace, automotive, wind energy, sports, and robotics, which makes the precision modelling of its machining operations a critical research area. However, the classic finite element modelling (FEM) approach has limitations in capturing the complexity of machining, particularly with regard to the interaction between the fibre–matrix interface and the cutting edge. To overcome this limitation, a hybrid approach that integrates smoothed particle hydrodynamics (SPHs) with FEM was developed and tested in this study. The hybrid FEM-SPH approach was compared with the classic FEM approach and validated with experimental measurements that took into account the cutting tool’s round edge. The results showed that the hybrid FEM-SPH approach outperformed the classic FEM approach in predicting the thrust force and bounce back of CFRP machining due to the integrated cohesive model and the element conversion after failure in the developed approach. The accurate representation of the fibre–matrix interface in the FEM-SPH approach resulted in predicting precise chip formation in terms of direction and morphology. Nonetheless, the computing time of the FEM-SPH approach is higher than the classic FEM. The developed hybrid FEM-SPH model is promising for improving the accuracy of simulation in machining processes, combining the benefits of both techniques

Spirulina Ameliorates Oxidative Damage and Inflammation in Rotenone-Induced Neurotoxicity in Male Mice

Background: Rotenone, a chemical compound produced naturally by leguminous plants, has conventionally been used as a pesticide by blocking the uptake of oxygen by body cells. Our study aimed to investigate the effect of spirulina on oxidative damage, inflammation, and neurotoxicity in male mice treated by rotenone.Methods: The experimental animals were divided into 5 groups. Group (I) served as control that received Dimethyl Sulfoxide (DMSO); Group (II) mice treated with rotenone (1.5 mg/kg, s.c.3 times per week); Group (III) mice received rotenone/L-dopa (25 mg/kg, P.O. daily); Group (IV) and Group (V) mice were treated with rotenone/spirulina (200 and 400 mg/kg, P.O. daily) respectively for two weeks.Results: Rotenone-treated mice indicated impaired motor coordination and activity in wire hanging, wood walking, open field, and stair tests. Furthermore, rotenone treatment caused elevation in striatal levels of Malondialdehyde (MDA), Nitric Oxide (NO), Tumor Necrosis Factor (TNF-α), Interleukin -1 beta (IL-1β), and caspase 3 and decrement in Bcl-2; dopamine and Glutathione (GSH) levels. Moreover, severe neuronal degeneration, striatal DNA fragmentation, and increased striatal 8-OHdG levels and MTH1 expression in the rotenone group. Additionally, spirulina treatment prevented rotenone-induced motor deficits striatal DNA fragmentation and demonstrated good restoration of the substantial neurons with reservation of the typical dark appearance. Besides, rotenone-induced biochemical changes were ameliorated by spirulina treatment as dopamine, Bcl-2, and GSH levels were increased, and striatal MDA, TNF-α, IL-1β, and caspase 3 levels were decreased.Conclusion: Natural products like spirulina could reverse rotenone-induced neurotoxicity in male mice due to their anti-inflammatory and antioxidant properties

GRIDKIT: Pluggable overlay networks for Grid computing

A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks

Chip formation and orthogonal cutting optimisation of unidirectional carbon fibre composites

This study presents a thorough experimental investigation utilising the design of experiments and analysis of variance (ANOVA) to examine the impact of machining process parameters on chip formation mechanisms, machining forces, workpiece surface integrity, and damage resulting from the orthogonal cutting of unidirectional CFRP. The study identified the mechanisms behind chip formation and found it to significantly impact the workpiece orientation of fibre and the tool’s cutting angle, resulting in increased fibre bounceback at larger fibre orientation angles and when using smaller rake angle tools. Increasing the depth of cut and fibre orientation angle results in an increased damage depth, while using higher rake angles reduces it. An analytical model based on response surface analysis for predicting machining forces, damage, surface roughness, and bounceback was also developed. The ANOVA results indicate that fibre orientation is the most significant factor in machining CFRP, while cutting speed is insignificant. Increasing fibre orientation angle and depth leads to deeper damage, while larger tool rake angles re-duce damage. Machining workpieces with 0° fibre orientation angle results in the least subsurface damage, and surface roughness is unaffected by the tool rake angle for fibre orientations between 0° to 90° but worsens for angles greater than 90°. Optimisation of cutting parameters were subsequently optimised to improve machined workpiece surface quality and reduce forces. The experimental results showed that negative rake angle and cutting at moderately low speeds (366 mm/min) is the optimal conditions for machining laminates with a fibre angle of θ = 45°. On the other hand, for composite materials with fibre angles of θ = 90° and θ = 135°, it is recommended to use a high positive rake angle and cutting speeds

Using negative velocity feedback controller to reduce the vibration of a suspended cable

The system of suspended cable with mixed excitation forces is controlled in this paper by using negative linear velocity feedback controller. The equations of motion of this system contain quadratic and cubic nonlinearities. The multiple scale perturbation technique is applied to determine the response of the nonlinear system near the simultaneous sub-harmonic and combined resonance case of this system. The stability of the obtained numerical solution is investigated using frequency response equations. The effect of different parameters on the vibrating system are investigated and reported