Synthesis And Characterisation Of CdxZn1–xS Nanocomposites

CdxZn1 – xS nanoparticles have been synthesized using hydrothermal method. Structural characterization was done by XRD where the lattice structure gradually changes from hexagonal to cubic with increasing percentage of Zn inCdxZn1 – xS nanoparticles. Optical spectroscopy provided evidence that the absorption edges of those nanoparticles can be varied from blue to UV. The nanoparticles exhibit emission peaks that shift to shorter wavelength with increasing percentage of Zn in the compounds CdxZn1 – xS. The control of the composition of CdxZn1 – xS nanoparticles may lead the development of ideal materials for short wavelength diode laser applications. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/951

A System Dynamics Approach for Hospital Waste Management in a City in a Developing Country: The Case of Nablus, Palestine

Hospitals and health centers provide a variety of healthcare services and normally generate hazardous waste as well as general waste. General waste has a similar nature to that of municipal solid waste and therefore could be disposed of in municipal landfills. However, hazardous waste poses risks to public health, unless it is properly managed. The hospital waste management system encompasses many factors, i.e., number of beds, number of employees, level of service, population, birth rate, fertility rate, and not in my back yard (NIMBY) syndrome. Therefore, this management system requires a comprehensive analysis to determine the role of each factor and its influence on the whole system. In this research, a hospital waste management simulation model is presented based on the system dynamics technique to determine the interaction among these factors in the system using a software package, ithink. This model is used to estimate waste segregation as this is important in the hospital waste management system to minimize risk to public health. Real data has been obtained from a case study of the city of Nablus, Palestine to validate the model. The model exhibits wastes generated from three types of hospitals (private, charitable, and government) by considering the number of both inpatients and outpatients depending on the population of the city under study. The model also offers the facility to compare the total waste generated among these different types of hospitals and anticipate and predict the future generated waste both infectious and non-infectious and the treatment cost incurred

A comprehensive review of 3D printing techniques for biomaterial-based scaffold fabrication in bone tissue engineering

Three-dimensional (3D) printing technology is developing as a dominant tool for biomedical engineering by supporting 3D cell culture within compound 3D biomimetic buildings. Biomaterial and Tissue engineering has developed as a favorable alternative method in the treatment of bones, teeth, and organs. This paper summarizes the current research status and attention of the 3D biomaterials scaffolds in bone tissue engineering applications. Several 3D scaffolds fabricated from several types of biodegradable materials have been established. The crucial topics of 3D printing techniques are recognized and deliberated with the future improvement of innovative biomaterials. There has been a prompt development in the applications of 3D printing in engineering customized implants, drug delivery devices, prostheses, and 3D scaffolds for regenerative medicine and tissue engineering. Medical 3D printing technologies are classified into the following categories: Fused Deposition Modeling (FDM), Extrusion-based 3D bioprinting, Selective Laser Sintering (SLS)/Selective Laser melting (SLM), Electron Beam Manufacturing (EBM), Stereolithography (SLA) and Digital Light Processing (DLP) printing techniques, and their clinical applications, different types of biomaterials currently used by researchers, and key limitations are discussed in detail. In Addition, the most advanced and commonly used metals, bioceramics, polymers, and composites in tissue engineering are briefly reviewed as well

3D-printed Biphasic Calcium Phosphate Scaffold to augment cytocompatibility evaluation for load-bearing implant applications

In this work, we developed and analyzed a biphasic calcium phosphate (BCP) bioceramic for bone regeneration using stereolithography (SLA). The SLA method is a promising additive manufacturing (AM) technique capable of creating BCp parts with high accuracy and efficiency. However, the ceramic suspension used in SLA exhibits significantly higher viscosity and is not environmentally friendly. Therefore, adequate preparation of a suspension with low viscosity and high solid loading is essential. In this paper, we optimized the effects of surfactant doses and solid loading on the BCp slurry, and initially examined the process parameters of photocuring, debinding, and sintering. The utilization of 9 wt % Disperbyk (BYK) with a 40 vol % loading of BCp bioceramics exhibited a reasonably low viscosity of 8.9 mPa·s at a shear level of 46.5 s−1. Functional and structural analyses confirmed that BCp was retained after photocuring and subsequent treatment, which were incorporated into the BYK dispersion. The 3D printed objects with different sintered temperatures, specifically at 1100 °C, 1200 °C, and 1300 °C, were further optimized. Additionally, the surface roughness, porosity, and mechanical properties of BCp green parts were systematically investigated. Most importantly, in vitro analysis of cell attachment, differentiation, and red alizarin analysis could support the application of bone regeneration

Controlled degradation and kinetics response in calcium silicate doped with sodium alginate/functionalized multi-walled carbon nanotube composite 3D scaffolds for cartilage regeneration

Development of bio-mimetic scaffolds with controlled degradation is a key research area in cartilage regeneration. Therefore, novel scaffold composites and favorable techniques to fabricate essential 3D scaffolds are crucial. In this investigation, we achieved controlled biodegradation of composite scaffolds by incorporating calcium silicate (CS) into sodium alginate (SA)/functionalized with multi-walled carbon nanotubes (f-MWCNT). The SA/f-MWCNT and scaffolds with various amounts of CS (5, 10, and 15%) were shown to enhance scaffold properties. We conducted analyses of the composites using X-ray diffraction and scanning electron microscopy. The findings indicated that CS was successfully loaded onto SA/f-MWCNT, and after inclusion the CS crystal structure remained unaltered. We also evaluated the composites using differential scanning calorimetry, and we determined the mechanical strength, swelling, porosity, degradation, and pH properties. The 15% CS-SA/f-MWCNT scaffolds demonstrated improved mechanical properties, controlled degradation and swelling ratio, increased material density, and strengthened bonds that resulted in a more compact structure and better control of porosity. Furthermore, kinetic investigations of the composite scaffolds to potentially absorb water could be accurately modeled using the pseudo-first-order, pseudo-second-order, Elovich, and diffusion kinetic models. The gradual water absorption rate observed in 15% CS-SA/f-MWCNT could be attributed to controlled intraparticle and micropore diffusion. Further biocompatibility studies showed that the scaffold encouraged chondrocyte attachment, spreading, and division. Additionally, collagen deposition and biomineralization of the 15% CS-SA/f-MWCNT scaffolds were slightly higher compared to the SA/f-MWCNT, 5% CS-SA/f-MWCNT, and 10% CS-SA/f-MWCNT scaffolds. The results indicated that the 15% CS-SA/f-MWCNT fabricated scaffolds are the most suitable for cartilage regeneration

Electrophoretic bilayer deposition of zirconia and reinforced bioglass system on Ti6Al4V for implant applications: An in vitro investigation

The physical, chemical and biological properties of the bioglass reinforced yttria-stabilized composite layer on Ti6Al4V titanium substrates were investigated. The Ti6Al4V substrate was deposited with yttria stabilized zirconia - YSZ as the base layer of thickness approximate to 4-5 mu m, to inhibit metal ion leach out from the substrate and bioglass zirconia reinforced composite as the second layer of thickness approximate to 15 mu m, which would react with surrounding bone tissue to enhance bone formation and implant fixation. The deposition of these two layers on the substrate was carried out using the most viable electrophoretic deposition (EPD) technique. Biocompatible yttria-stabilized zirconia (YSZ) in the form of nano-particles and sol gel derived bioglass in the form of micro-particles were chosen as precursors for coating. The coatings were vacuum sintered at 900 degrees C for 3 h. The biocompatibility and corrosion resistance property were studied in osteoblast cell culture and in simulated body fluid (SBF) respectively. Analysis showed that the zirconia reinforced bioglass bilayer system promoted significant bioactivity, and it exhibited a better corrosion resistance property and elevated mechanical strength under load bearing conditions in comparison with the monolayer YSZ coating on Ti6Al4V implant surface. (C) 2013 Elsevier B.V. All rights reserved

Dynamics of Heat Transfer Analysis of Convective-Radiative Fins with Variable Thermal Conductivity and Heat Generation: Differential Transformation Method

The study of convective heat transfer in differently shaped fins with radiation, internal heat generation and variable thermal conductivity was considered. The energy equation of the model was converted into the dimensionless form by adopting the proper variables, which was later solved using the differential transformation method. The impact of the parameters on the thermal performance, efficiency and heat transfer of the fins was analyzed graphically and also by performing thermal analysis on the fins. It was noticed that there was a significant effect on the thermal performance of the fins with different shapes, and also the heat transfer rate of the fin increased for improved values of the internal heat generation and radiation parameters. The exponential profile showed better results than other profiles, and the results obtained were supported by thermal analysis using ANSYS software