Wire ropes undergo a fretting fatigue condition when subjected to axial and bending loads. The fretting behavior of wires are classified as line contact and trellis point of contact. The experimental study on the fatigue of wire ropes indicates that most of the failure occurs due to high localized stresses at trellis point of contact. A continuum damage mechanics approach was previously proposed to estimate the fatigue life estimation of wire ropes. The approach majorly depends on the high value of localized stresses as well as the micro-slippage occurs at the contact region. Finite element approach has been used to study radial and axial distribution of stresses and displacement in order to clearly understand the evolution of stresses and existence of relative displacements between neighboring wires under various loading and frictional conditions. The relative movements of contacting wires are more when friction is not considered. In the presence of friction, the relative movement occurs at the boundaries of the contact region. The location of microslip in the presence of friction is backed by the experimental observation stating the crack is initiated at or the outer boundary of the contact spot. The existence of slip is due to different displacement of outer and central wires.
Implants are widely used in the human body for the replacement of affected bones. Fatigue failure is one of the serious concerns for implants. Therefore, understanding of the underlying mechanism leading to fatigue failure is important for the longevity of biomaterial implants. In this paper, the fracture toughness and fatigue crack growth of titanium alloy biomaterial Ti-27Nb has been experimentally investigated. The Ti-27Nb material is tested for fatigue crack growth in different environmental conditions representing the ambient and in vitro environments for 504 hours and 816 hours, respectively. Fractography of the tested specimen is conducted using Scanning Electron Microscope (SEM). The results of the fatigue crack growth propagation of the ambient and in vitro samples are similar in the Paris crack growth region. However, in the threshold region, the crack growth rate is higher for the Simulated Body Fluid (SBF) treated specimen. The fracture surface morphology of in vitro samples shows brittle fracture as compared to ambient specimens with significant plasticity and striations marks. It is proposed that a similar investigation may be conducted with specimens treated in SBF for prolonged periods to further ascertain the findings of this study.
Buffing dust, generated from tannery industries, is a source of air pollution in Pakistan. Valorization of the waste into another useful material is important to deal with the environmental pollution, while reducing waste disposal costs in landfills. To demonstrate its technological strength, this work fabricates a thermal insulation material made of plaster of Paris and the buffing dust (from tanning waste) in the form of a composite with superior mechanical properties and low thermal conductivity. Buffing dust with concentrations ranging from 5 to 20% (w/w) were loaded in the composite. The samples synthesized were made slurry of plaster of Paris, buffing dust, and water at ambient temperature. The physico-mechanical properties of composite were analyzed. It was found that the composite had better thermal insulation properties than the panels of the plaster of Paris. Its thermal conductivity was reduced to 15% after adding buffing dust (20% w/w). All the materials had physico-chemical properties like tensile strength (0.02 MPa and 0.06 MPa), density (700-400 kg/m3), water absorption (5.2-8.6%) and thermal conductivity (0.17000-0.09218 W/m-K). Thermogravimetric analysis showed that the material was thermally stable at temperatures ranging from 145 to 177 °C, while FT-IR results revealed that the composite contained O-H, N-H, and CO functional groups. SEM analysis displayed that the composite's homogeneity was reduced with low voids due to buffing dust addition, while EDX analysis showed that the composite contained 23.62% of S, 26.76% of Ca, 49.2% of O and 0.42% of C. This implies that buffing dust could be recycled to manufacture heat insulation materials for construction sector to reduce air pollution, while minimizing energy consumption. By integrating the buffing dust from tanning waste and the plaster of Paris as a composite for construction sector, this work promotes the recycling of unused waste, while saving public funds. Instead of paying landfill fees and polluting soil, the waste may be recycled at lower cost, while reducing environmental damage.
Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.
Textile wastewater laden with dyes has emerged as a source of water pollution. This possesses a challenge in its effective treatment using a single functional material. In respond to this technological constraint, this work presents multifunctional cotton fabrics (CFs) within a single, streamlined preparation process. This approach utilizes the adherence of Ag NPs (nanoparticles) using Si binder on the surface of CFs, resulting in Ag-coated CFs through a pad dry method. The prepared samples were characterized using scanning electron microscope-energy dispersive X-ray electroscopy (SEM-EDS), thermal gravimetric analysis (TGA), Fourier transformation infrared (FT-IR). It was found that the FT-IR spectra of Ag NPs-coated CFs had peaks appear at 3400, 2900, and 1200 cm-1, implying the stretching vibrations of O-H, C-H, and C-O, respectively. Based on the EDX analysis, the presence of C, O, and Ag related to the coated CFs were detected. After coating the CFs with varying concentrations of Ag NPs (1%, 2% and 3% (w/w)), they were used to remove dyes. Under the same concentration of 10 mg/L and optimized pH 7.5 and 2 h of reaction time, 3% (w/w) Ag-coated CFs exhibited a substantial MB degradation of 98 %, while removing 95% of methyl orange, 85% of rhodamine B, and 96% of Congo red, respectively, following 2 h of Vis exposure. Ag NPs had a strong absorption at 420 nm with 2.51 eV of energy band gap. Under UV irradiation, electrons excited and produced free radicals that promoted dyes photodegradation. The oxidation by-products included p-dihydroxybenzene and succinic acid. Spent Ag-coated CFs attained 98% of regeneration efficiency. The utilization of Ag-coated CFs as a photocatalyst facilitated treated effluents to meet the required discharge standard of lower than 1 mg/L mandated by national legislation. The integration of multifunctional CFs in the treatment system presents a new option for tackling water pollution due to dyes.
Biomolecules have been widely investigated as potential therapeutics for various diseases. However their use is limited due to rapid degradation and poor cellular uptake in vitro and in vivo. To address this issue, we synthesized a new nano-carrier system comprising of cholic acid-polyethylenimine (CA-PEI) copolymer micelles, via carbodiimide-mediated coupling for the efficient delivery of small interfering ribonucleic acid (siRNA) and bovine serum albumin (BSA) as model protein. The mean particle size of siRNA- or BSA-loaded CA-PEI micelles ranged from 100-150 nm, with zeta potentials of +3-+11 mV, respectively. Atomic force, transmission electron and field emission scanning electron microscopy demonstrated that the micelles exhibited excellent spherical morphology. No significant morphology or size changes were observed in the CA-PEI micelles after siRNA and BSA loading. CA-PEI micelles exhibited sustained release profile, the effective diffusion coefficients were successfully estimated using a mathematically-derived cylindrical diffusion model and the release data of siRNA and BSA closely fitted into this model. High siRNA and BSA binding and loading efficiencies (95% and 70%, respectively) were observed for CA-PEI micelles. Stability studies demonstrated that siRNA and BSA integrity was maintained after loading and release. The CA-PEI micelles were non cytotoxic to V79 and DLD-1 cells, as shown by alamarBlue and LIVE/DEAD cell viability assays. RT-PCR study revealed that siRNA-loaded CA-PEI micelles suppressed the mRNA for ABCB1 gene. These results revealed the promising potential of CA-PEI micelles as a stable, safe, and versatile nano-carrier for siRNA and the model protein delivery.
Renewable energy systems are vital for a sustainable future, where solid-state hydrogen storage can play a crucial role. Perovskite hydride materials have attracted the scientific community for hydrogen storage applications. The current work focuses on the theoretical study using density functional theory (DFT) to evaluate the characteristics of MgXH3 (X = Co, Cu, Ni) hydrides. The structural, vibrational, electronic, mechanical, thermodynamic, and hydrogen storage properties of these hydrides were investigated. The equilibrium lattice parameters were calculated using the Birch-Murnaghan equation of state-to-energy volume curves. The elastic constants (Cij) and relevant parameters, such as Born criteria, were calculated to confirm the mechanical stability of the hydrides. The Cauchy pressure (Cp) revealed brittle or ductile behavior. The outcomes of the Pugh ratio, Poisson ratio, and anisotropy were also calculated and discussed. The absence of negative lattice vibrational frequencies in phonon dispersion confirmed the lattice's dynamic stability. The heat capacity curves of thermodynamic properties revealed that hydrides can conduct thermal energy. The metallic character and ample interatomic distances of hydrides were confirmed by the band structure and population analysis, which confirmed that hydrides can conduct electrical energy and adsorb hydrogen. The density of state (DOS) and partial DOS unveiled the role of specific atoms in the DOS of the crystal. The calculated gravimetric hydrogen storage capacity of MgCoH3, MgCuH3, and MgNiH3 hydrides was 3.64, 3.32, and 3.49wt%, respectively. Our results provide a deeper understanding of its potential for hydrogen storage applications through a detailed analysis of MgXH3 (X = Co, Cu, Ni) perovskite hydride material.
Introduction: Breast cancer is a global health challenge with significant mortality, affecting millions worldwide. The current study is aimed at evaluating awareness and practices related to breast cancer screening, prevention, and treatment among the general public and physicians in Lahore, Pakistan, which has a significant incidence of breast cancer. Methodology: The current study adopted a cross-sectional study design conducted in Lahore, Pakistan, between March and August 2023, among 404 participants from the general public and 240 physicians. Data collection and evaluation involved the use of validated questionnaires, and both descriptive and inferential statistics were performed using SPSS Version 25. Result: In Lahore, Pakistan, breast cancer awareness among the public was low, with 80.2% unaware of its global prevalence, 65.3% believing not everyone is at risk, and only 42.1% recognizing symptoms. Females showed greater awareness (OR: 1.020, CI: 0.617-1.686, p = 0.002) and positive attitudes (OR: 2.711, CI: 1.478-6.478, p = 0.045), while the 18-29 age group had higher odds of positive practices (OR: 4.317, CI: 2.678-5.956, p = 0.004). Educational attainment significantly influences knowledge and attitudes. Only 13.9% practiced self-examination. Among physicians, 88.8% were confident in screenings, but patient fear (42.9%) and financial barriers (79.2%) hindered action. Physicians with FCPS qualifications had higher odds of awareness (OR: 1.550, CI: 1.130-2.117, p = 0.007), attitudes (OR: 1.500, CI: 1.050-2.150, p = 0.025), and practices (OR: 1.470, CI: 1.070-2.017, p = 0.020). Those with 11-20 years of experience also showed better awareness (OR: 1.400, CI: 1.050-1.868, p = 0.022) and attitudes (OR: 1.450, CI: 1.045-2.018, p = 0.029). Conclusion: In conclusion, breast cancer awareness among the general public is limited, highlighting the need for tailored education programs. Although most physicians show high awareness, challenges in patient communication and barriers, such as fear and financial constraints, must be addressed to improve screening uptake. These findings emphasize the importance of targeted interventions to enhance public awareness, screening practices, and physician-patient communication.