Investigating the effects of cement and cement kiln dust as a filler on the mechanical properties of cold bituminous emulsion mixtures

The application of cold mixes is lagging behind in the research field, which is quite obvious in a developing country. Furthermore, cold mixes have more economic and environmental advantages than hot mixes. This is the principal motivation for the present research, which aims to improve the mechanical properties of cold mix asphalt. Ordinary Portland cement (OPC) and cement kiln dust (CKD) were used as filler in cold bituminous emulsion mixtures (CBEMs) to compare the obtained results with those for CBEMs with conventional limestone. Indirect Tensile Stiffness Modulus (ITSM), fatigue, and resistance to rutting tests were used in the comparison. The experimental results showed that CBEMs with CKD and OPC had comparative mechanical properties to CBEMs with limestone and hot mix asphalt of the same grading and materials. Thus, this research introduces a new cold mix with CKD or OPC, which is able to meet more than the mechanical characteristics' requirements, reduce costs, and provide environmental benefits. © IAEME Publication

Dynamic Analysis Of A Novel Manpowered Transportation Vehicle With High Mechanical Efficiency

This paper evaluates the dynamics of a novel manpowered transportation vehicle. The vehicle has a novel mechanism that maximizes the mechanical input work and utilizes the weight of the rider for propulsion. The rider applies reciprocating stepping linear forces to drive chain and ratchet mechanism. The later transfer the reciprocating motion into a unidirectional rotational motion at the rear wheel to propel the vehicle. We analyzed the dynamics of the driving and transmission mechanism and derived the equations of motion, at first. Then, we evaluated the performance of the vehicle. Results show significant advantages of the novel driving mechanism

Ethyl 1-(4-methyl­phen­yl)-5-phenyl-4-phenyl­sulfon­yl-1H-pyrazole-3-carboxyl­ate

The title compound, C25H22N2O4S, features a tetra-substituted pyrazole ring. The dihedral angles formed between the five-membered ring (r.m.s. deviation = 0.007 Å) and the N- and C-bound phenyl rings are 48.10 (7) and 72.01 (7) °, respectively, indicating that the planes through the residues are significantly twisted from the plane through the heterocycle. The ester-CO2 group is also twisted out of this plane, with an O—C—C—N torsion angle of −29.04 (11)°. The sulfonyl-O atoms lie to one side of the pyrazole plane and the sulfonyl­phenyl ring to the other. The dihedral angle between the two ring planes is 70.63 (7) °. Supra­molecular arrays are formed in the crystal structure sustained by C—H⋯O and C—H⋯π(pyrazole) inter­actions and methyl-C—H⋯π(N-bound benzene) contacts

Application of PSO to Design UPFC-based Stabilizers

Today, power demand grows rapidly and expansion in transmission and generation is restricted with the limited availability of resources and the strict environmental constraints. Consequently, power systems are today much more loaded than before. In addition, interconnection between remotely located power systems turned out to be a common practice. These give rise to low frequency oscillations in the range of 0.1-3.0 Hz. If not well damped, these oscillations may keep growing in magnitude until loss of synchronism results. Power system stabilizers (PSSs) have been used in the last few decades to serve the purpose of enhancing power system damping to low frequency oscillations. PSSs have proved to be efficient in performing their assigned tasks. The objective of this chapter is to investigate the potential of particle swarm optimization as a tool in designing UPFC-based stabilizers to improve power system transient stability. To estimate the controllability of each of the UPFC control signals on the electromechanical modes, singular value decomposition is employed. The problem of designing all the UPFCbased stabilizers individually is formulated as an optimization problem. Particle swarm optimizer is utilized to search for the optimum stabilizer parameter settings that optimize a given objective function. Coordinated design of the different stabilizers is also carried out by finding the best parameter settings for more than one stabilizer at a given operating condition in a coordinated manner

Histological, immunohistochemical and ultrastructural study of secondary compressed spinal cord injury in a rat model

Introduction. Spinal cord injury (SCI) is a life-disrupting condition in which the first few days are the most critical. Secondary conditions remain the main causes of death for people with SCI. The response of different cell types to SCI and their role at different times in the progression of secondary degeneration are not well understood. The aim of this study was to study the histopathological changes of compressed spinal cord injury (CSCI) in a rat model. Material and methods. Forty adult male Sprague-Dawley rats were divided into four groups. In group I, the rats were left without any surgical intervention (control). In group II, the rats were subjected to laminectomy without spinal cord compression (sham-operated). In group III, the rats were sacrificed one day after CSCI. In group IV, the rats were sacrificed seven days after CSCI. The light microscopy was employed to study the morphology using H&E, osmic acid staining and immunohistochemistry to detect glial fibrillary acidic protein (GFAP). The electron microscopy was applied for ultrastructure study. Results. Histopathological examination of the posterior funiculus of the white matter revealed minute hemorrhages and localized necrotic areas on day 1, which transformed to areas of cavitation and fibrinoid necrosis surrounded by a demarcating rim of numerous astrocytes by day 7. The mean percentage of area of GFAP expression increased significantly by day 7. Osmic acid staining revealed swollen nerve fibers after one day, while numerous fibers had been lost by day 7. An ultrastructure study revealed swollen redundant thinned myelin and myelin splitting, as well as degeneration of axoplasm on day 1. On day 7, layers of the myelin sheath were folded and wrinkled with partial or complete demyelination areas. The myelin lamellae were disorganized and loose. The G-ratio was significantly greater on day 1 than day 7 after CSCI. Conclusions. In the rat model of CSCI details of the progressive spinal cord injury can be analyzed by morphological methods and may be helpful in the identification of the onset and type of clinical intervention

2-(1H-1,3-Benzodiazol-2-ylsulfan­yl)-1-(4-chloro­phen­yl)ethanone

The mol­ecule in the structure of the title compound, C15H11ClN2OS, displays two planar residues [r.m.s. deviation = 0.014 Å for the benzimidazole residue, and the ketone group is co-planar with the benzene ring to which it is attached forming a O—C—C—C torsion angle of −173.18 (14) °] linked at the S atom. The overall shape is based on a twisted V, the dihedral angle formed between the two planes being 82.4 (2) °. The amine-H atom is bifurcated, forming N—H⋯O and N—H⋯S hydrogen bonds leading to dimeric aggregates. These are linked into a supra­molecular chain along the c axis via C—H⋯π hydrogen bonds. Chains form layers in the ab plane being connected along the c axis via weak π–π inter­actions [3.9578 (8) Å] formed between centrosymmetrically related chloro-substituted benzene rings

Influence of Different Decontamination Approaches on Bone Substitute Adhesion to Peri-Implantitis Affected Implant Surfaces: An SEM Proof of Principle Study

Background: During healing, clot blended graft materials may retract away from implant surfaces creating microgaps that compromise re-osseointegration. The present study aimed to evaluate different surface decontamination materials’ effect on adhesion of the graft materials to peri-implantitis affected parts, a factor that can resist clot blended graft retraction improving re-osseointegration. Methods: Eighteen peri-implantitis affected implants diagnosed as hopeless and designated for removal contributed in this prospective, masked trial. Samples were randomly distributed into three groups, each of six implants. Group one (G1) was coated with hydroxyapatite of a micro particle size of 250 to 1000 µm after saline surface decontamination for two minutes. Group two (G2) peri-implantitis affected parts were treated with the graft material following two minutes of chlorhexidine gluconate 0.12% (CHX) surface treatment. Group three (G3) implants were coated with the graft material after citric acid (CA) (pH = 1) surface conditioning for two minutes. Implants in all groups were agitated in phosphate-buffered saline (PBS) by using an automatic tissue processor agitator for three minutes. Implants were prepared for surface scanning evaluation. Results: Scanning electron microscopy (SEM) observation of G1 saline treated control implants were devoid of bone particles adherent to peri-implantitis affected surfaces. The surface area covered by grafted particles in G2 was statistically higher than that of G1 (P<0.01). Group three (CA-treated) showed nearly complete coverage of peri-implantitis affected parts by the graft material covering 88.8% of examined surface areas which was statistically higher than that of G2 (P<0.05). Conclusion: Citric acid implant surface conditioning could improve implant re-osseointegration through enhancement of the graft adhesion to the implant surface. Smear layer barrier effect seemed to be the most important factor that compromised graft adhesion to preri-implantitis affected parts of the implant surfaces

Design and Fabrication a W-Shape Form Dual-Band Flexible Antenna For Biomedical Applications

This study suggests a dual band flexible antenna for use at 900 and 2450 MHz. With a footprint of 0.23 o, 0.120 o, and 0.0007 o, where o is the lowest resonance wavelength, the antenna is relatively tiny. The antenna is built from a straightforward geometrical structure consisting of a W-shaped serpentine structure supplied by a microstrip line and a partial ground plane utilizing the Defected Ground Structure (DGS) technology in order to achieve wide operational bandwidth. In order to boost resonance, an additional capacitor was inserted between the slots, creating a portable dual-band antenna. Several performance metrics\u27 findings and the ones that had been measured were compared. The antenna\u27s potential for rigid and flexible electronics is increased by its good size, bandwidth, gain, and radiation pattern

Simultaneous Stabilization Of Power System Using UPFC-Based Controllers

This article studies the use of robust UPFC-based stabilizers to damp low frequency oscillations. The potential of the UPFC-based stabilizers to enhance the dynamic stability is evaluated by singular value decomposition. Particle swarm optimization technique is used to optimize the parameters of each stabilizer, first individually, then concurrently. To ensure the robustness of the proposed stabilizers, the design process considers a wide range of operating conditions. The effectiveness of the proposed controllers is verified through several linear and nonlinear analysis techniques. These techniques prove that the coordinated design of UPFC-based stabilizers is superior over any of the individual designs

Simultaneous Stabilization Of Power System Using UPFC-Based Controllers

This article studies the use of robust UPFC-based stabilizers to damp low frequency oscillations. The potential of the UPFC-based stabilizers to enhance the dynamic stability is evaluated by singular value decomposition. Particle swarm optimization technique is used to optimize the parameters of each stabilizer, first individually, then concurrently. To ensure the robustness of the proposed stabilizers, the design process considers a wide range of operating conditions. The effectiveness of the proposed controllers is verified through several linear and nonlinear analysis techniques. These techniques prove that the coordinated design of UPFC-based stabilizers is superior over any of the individual designs