Geometry and Mechanics

IASS-IACM 2008 Session: Geometry and Mechanics -- Session Organizers: Kai-Uwe BLETZINGER (TU Munich), Fehmi CIRAK (University of Cambridge) -- Keynote Lecture: "Modeling and computation of patient-specific vascular fluid-structure interaction using Isogeometric Analysis" by Yuri BAZILEVS , Victor M. CALO, Thomas J. R. HUGHES (University of Texas at Austin), Yongie ZHANG (Carnegie Mellon University) -- Keynote Lecture: "Optimal shapes of mechanically motivated surfaces" by Kai-Uwe BLETZINGER , Matthias FIRL, Johannes LINHARD, Roland WUCHNER (TU Munich) -- "Subdivision shells for nonsmooth and branching geometries" by Quan LONG, Fehmi CIRAK (University of Cambridge) -- "Water landing analyses with explicit finite element method" by John T. WANG (NASA Langley Research Center) -- "On a geometrically exact contact description for shells: From linear approximations for shells to high-order FEM" by Alexander KONYUKHOV, Karl SCHWEIZERHOF (University of Karlsruhe

Environmental Sustainability of Current Waste Management Practices

The Special Issue on ‘Environmental Sustainability of Current Waste Management Practices’ was a part of the section ‘Environmental Sustainability and Applications’ of the journal ‘Sustainability’ [...

Environmental Sustainability of Current Waste Management Practices

The Special Issue on ‘Environmental Sustainability of Current Waste Management Practices’ was a part of the section ‘Environmental Sustainability and Applications’ of the journal ‘Sustainability’ [...

An Overview of Dental Solid Waste Management and Associated Environmental Impacts: A Materials Perspective

Dental healthcare plays an important role in the overall health of individuals, and the sector is rapidly growing around the world due to increases in population, healthcare facilities, and improved access for economically weaker sections of society. Dental procedures and oral care generate a significant amount of biomedical waste that should be managed in an environmentally safe and sustainable manner. An overview is presented of the current status of dental solid waste management with a focus on waste composition from traditional and emerging dental treatments, new-generation dental materials, waste treatment procedures, and current options. Dental waste can be broadly divided into three categories: infectious waste, non-infectious waste, and domestic-type waste. Infectious waste contains materials contaminated with blood or other infectious mouth fluids, amalgam, and sharps, whereas non-infectious dental waste is devoid of human fluid contamination but can be potentially toxic due to the presence of amalgams, acids, metal dust, resins, etc. Suspended particulates in dental wastewater are another likely source of contamination. Appropriate segregation of this waste is essential for containing infections during waste processing. New-generation dental materials, such as nanomaterials, resin-based composites, and ceramics, are finding increasing applications in a variety of dental procedures as antimicrobial, restorative, and therapeutic agents. While incineration and landfilling have been used for processing traditional dental waste, the presence of novel materials in dental waste raises several additional concerns. Novel single/multistage recycling approaches need to be developed for dental waste towards resource recovery, thus minimizing incineration and landfilling to the extent possible

An Overview on Solid Waste Generation and Management: Current Status in Chile

The widespread generation of, ever increasing volumes of and the sustainable management of solid wastes are global issues of great concern. Due to wide variations in composition and associated complexities, significant efforts are required for their collection, processing and environmentally safe disposal in a cost effective manner. An overview of solid wastes is presented in this article with a specific focus on municipal solid wastes and industrial waste from the iron/steelmaking and aluminium industries. Key waste issues such as its sources, compositions, volumes, the factors affecting waste generation and waste processing are first discussed, followed by a further discussion regarding recycling, resource recovery, disposal and the associated environmental impacts. In a special case study, waste generation and management in Chile is presented in greater detail. Detailed information is provided on government initiatives and legislation for integrated solid waste management and its movement towards a circular economy. Measures include regulations on waste management framework which concerns the transboundary movements of hazardous wastes, persistent organic pollutants, the closure of mining activities and installations and restrictions on plastics disposal. With Chile being world’s largest producer of copper, significant efforts for mining waste management, its infrastructure and procedures are being put in place to reduce the environmental impact of the mining sector and its associated waste generation

Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective

Managing red mud (RM), a solid waste byproduct of the alumina recovery process, is a serious ecological and environmental issue. With ~150 million tons/year of RM being generated globally, nearly 4.6 billion tons of RM are presently stored in vast waste reserves. RM can be a valuable resource of metals, minor elements, and rare earth elements. The suitability of RM as a low-grade iron resource was assessed in this study. The utilization of RM as a material resource in several commercial, industrial operations was briefly reviewed. Key features of iron recovery techniques, such as magnetic separation, carbothermal reduction, smelting reduction, acid leaching, and hydrothermal techniques were presented. RMs from different parts of the globe including India, China, Greece, Italy, France, and Russia were examined for their iron recovery potential. Data on RM composition, iron recovery, techniques, and yields was presented. The composition range of RMs examined were: Fe2O3: 28.3–63.2 wt.%; Al2O3: 6.9–26.53 wt.%; SiO2: 2.3–22.0 wt.%; Na2O: 0.27–13.44 wt.%; CaO: 0.26–23.8 wt.%; Al2O3/SiO2: 0.3–4.6. Even with a high alumina content and high Al2O3/SiO2 ratios, it was possible to recover iron in all cases, showing the significant potential of RM as a secondary resource of low-grade iron

Spark Plasma Sintering of Cobalt Powders in Conjunction with High Energy Mechanical Treatment and Nanomodification

Spark plasma sintering (SPS) investigations were carried out on three sets of Co specimens: untreated, high energy mechanically (HEMT) pre-treated, and nanomodified powders. The microstructure, density, and mechanical properties of sintered pellets were investigated as a function of various pre-treatments and sintering temperatures (700–1000 °C). Fine-grained sinters were obtained for pre-treated Co powders; nano-additives tended to inhibit grain growth by reinforcing particles at grain boundaries and limiting grain-boundary movement. High degree of compaction was also achieved with relative densities of sintered Co pellets ranging between 95.2% and 99.6%. A direct co-relation was observed between the mechanical properties and densities of sintered Co pellets. For a comparable sinter quality, sintering temperatures for pre-treated powders were lower by 100 °C as compared to untreated powders. Highest values of bending strength (1997 MPa), microhardness (305 MPa), and relative density (99.6%) were observed for nanomodified HEMT and SPS processed Co pellets, sintered at 700 °C

Sorbent Based on Polyvinyl Butyral and Potassium Polytitanate for Purifying Wastewater from Heavy Metal Ions

Currently, the rapid development of industry leads to an increase in negative anthropogenic impacts on the environment, including water ecosystems. This circumstance entails toughening environmental standards and, in particular, requirements for the content of pollutants in wastewater. As a result, developing technical and cost-effective ways for wastewater purification becomes relevant. This study is devoted to the development of a novel composite sorbent, based on polyvinyl butyral and potassium polytitanate, designed to purify water from heavy metal ions. The co-deposition of a mixture based on a polymer solution and a filler suspension was used to obtain a composite material. In this work, the influence of the deposition conditions on the structure and properties of the resulting composites was studied, as well as the optimal ratio of components, including solvent, precipitant, polymer binder, and filler, were established. In the course of this study on the sorption properties of the developed composite materials using various sorption models, the sorption capacity of the obtained material, the sorption mechanism, and the limiting stage of the sorption process were determined. The developed sorbent can be suitably used in the wastewater treatment systems of galvanic industries, enterprises producing chemical current sources, and in other areas

Advances in Thermo-Electrochemical (TEC) Cell Performances for Harvesting Low-Grade Heat Energy: A Review

Thermo-electrochemical cells (also known as thermocells, TECs) represent a promising technology for harvesting and exploiting low-grade waste heat (2+/3+, with great opportunities for further development in both aqueous and non-aqueous solvents. New thermoelectric applications in the field include wearable and portable electronic devices in the health and performance-monitoring sectors; using body heat as a continuous energy source, thermoelectrics are being employed for long-term, continuous powering of these devices. Energy storage in the form of micro supercapacitors and in lithium ion batteries is another emerging application. Current thermocells still face challenges of low power density, conversion efficiency and stability issues. For waste-heat conversion (WHC) to partially replace fossil fuels as an alternative energy source, power generation needs to be commercially viable and cost-effective. Achieving greater power density and operations at higher temperatures will require extensive research and significant developments in the field