Efficient Use Of Materials Research Articles

Legal regulation of ecological tourism in Arctic

Ecological tourism is one of the current trends in development of Arctic. There are several reasons for this: popularity of ecological tourism among modern travelers in general and competitiveness of Arctic travel in a unique and diverse nature; profitability of ecological entrepreneurship; environmental, socio-economic and educational importance of ecological tourism for sustainable development of Arctic. Accordingly, the legal regulation of ecological tourism in Arctic should serve the purpose of ensuring preservation of human capital, protection and reproduction of natural complex of Arctic, efficient use of material, financial and human resources based on modern achievements in the field of ecology and tourism technologies. Entrepreneurial activity in the field of ecological tourism in Arctic is carried out simultaneously in the context of international cooperation and interaction of professional entrepreneurs with local population of Arctic. It is important to consider possible impact of nature protection tourism on lifestyle of people living in Arctic. Indigenous people should have the right to preserve traditional way of life and, at the same time, opportunity to develop modern forms of self-organization, self-regulation. Legal guarantees for development of ecological tourism in Arctic are state support measures federal legislation, state programs, state budget.

Material Efficiency of Housing in Times of Demographic Change – Evidence from Case Study Research into two German Municipalities

Housing and construction have a significant impact on the consumption of resources of any society. At the same time, on all policy levels strategy documents towards sustainable development highlight the importance of improvements in resource efficiency. Against this background, this contribution presents results of research on the impact of demographic trends and changing user preferences on the use of resources within the housing sector with a focus on construction materials. The material intensity of different types of housing (in particular detached homes vs. apartment buildings) are quantified under different development scenarios drawn on the basis of two medium sized German case study municipalities showing declining and stagnating population development. Among other, the results indicate that the per capita stock of construction materials within the housing sector remains either stable or may even increase despite a falling population. With respect to alternative development scenarios, our results show, that under the condition of a stable or growing population a shift of housing supply from single-family (detached) homes towards a higher share of multi-unit residential buildings can contribute to a more efficient use of materials. An interesting option under the condition of a declining population is the conversion of a potentially growing number of vacant single-family homes into smaller multi-unit/multi-purpose residential buildings since it can help to avoid vacancy and keep otherwise wasted resources in use.

Dynamic structural responses of long-span dome structures induced by tornadoes

Long-span dome structures are widely used for public assembly venues because of their large column-free space and efficient use of materials. When occupied by hundreds or even thousands of people, it would be devastating if they fail or collapse, which unfortunately happen frequently during extreme events, especially under tornadic winds. Although static effects of tornadoes on civil structures have been extensively studied, their dynamic impact has not been sufficiently investigated. In this study, non-stationary characteristics of tornadoes and their dynamic impact on a long-span dome structure are systematically investigated. In particular, the time-variant wind pressure on the dome surface induced by translating tornadoes with different intensities is characterized through Computational Fluid Dynamics simulations. The obtained wind pressure is then mapped onto the finite element model of the dome structure, and transient time-history analyses are conducted to characterize the tornado-induced dynamic responses. It is observed that non-stationary wind pressure and the induced dynamic structural responses are significant, when core radius of the tornado approaches the dome. Wind flow of EF4 and EF5 tornadoes is found to be more turbulent than EF2 and EF3 tornadoes, and hence larger and more rapid fluctuations of dynamic responses.

Cement Concrete Mixture Performance Characterization

The cementitious composite nature of concrete makes very diffi cult directly ascertaining each mixture-factors’ contribution to a given concrete mixture performance characteristics but also doubly diffi cult to accurately balance mutually exclusive requirements for performance (workability, strength, durability) and sustainability (the economic and effi cient use of materials) for mixture proportioning based on recipes of previously produced concretes. This study sought to quantify individual mixture-factors’ contribution to a given concrete mixture’s performance characteristics. Proposed multi-parametric exponential mixture-response models were fi tted to available test-performance data sets of HPC mixtures proportioned based on the best combined grade aggregate (minimum void) to generate mixture-strength and mixture-porosity development (age-mixture response relationships) profi les of HPC mixtures and deemed robust enough to yield reliable determination of mixture-response rate-parameters So, Sp, Si and Po, Pp, Pi as functions of mixture-factors that permitted reliable quantifi cation of contributions to HPC mixture performance of individual mixture-factors and optimization of mixture properties under study over the study domain. Mixture-response sensitivity analysis models (or mixture response trace plots) to allow construction of mixture-factor envelopes and ultimately optimized mixture-response models to facilitate selection of optimal mixture-factors and optimal tailoring of HPC mixture requirements to HPC mixture performance were developed and used to obtain optimized adapted HPC mixtures from available high performance concrete (HPC) mixture design recipes investigated in the study over the study domain. Adapted HPC mixture design recipes yielded alternative mixture compositions with improved performance and effi ciency characteristics with statistical performance metrics MAPE, NMBE and RMSE values of 7.6%,–3.7% and 6.5 MPa, respectively.

Consideration of material efficiency in a learning factory

Abstract Due to steadily rising energy and raw material prices, material and energy costs are a key competitive factor for companies. The conscious and efficient use of material and energy resources can lead to high savings without large investments. By means of the shortage of resources and the high cost of materials of manufacturing companies, a material efficiency training was developed at the Lower Saxony Learning Factory for Resource Efficiency (NiFaR). The research identified a variety of approaches to increase material efficiency at the level of product development and production. Cross-sectional technologies to increase resource efficiency are well known. However, there is still a large deficit in the general understanding of the process. Therefore, the newly created training to increase material efficiency places special emphasis on lean management and process analysis. The participants learn the way from lean production to material efficient production. The course contents are modular and versatile. In addition to basic knowledge on waste prevention, the focus is still on sustainability, production technologies and the optimization of processes in order to make all processes as material efficient as possible. The theoretical content is taught using practical model examples in the production environment based on a real product.

Growth and Fabrication of High‐Quality Single Nanowire Devices with Radial p‐i‐n Junctions

Nanowires (NWs) with radial p-i-n junction have advantages, such as large junction area and small influence from the surface states, which can lead to highly efficient material use and good device quantum efficiency. However, it is difficult to make high-quality core-shell NW devices, especially single NW devices. Here, the key factors during the growth and fabrication process that influence the quality of single core-shell p-i-n NW devices are studied using GaAs(P) NW photovoltaics as an example. By p-doping and annealing, good ohmic contact is achieved on NWs with a diameter as small as 50-60 nm. Single NW photovoltaics are subsequently developed and a record fill factor of 80.5% is shown. These results bring valuable information for making single NW devices, which can further benefit the development of high-density integration circuits.

(Invited) Bioinspired Materials that can Sense and Adapt to Mechanical Loadings and Damages

Nature provides numerous examples of advanced materials with remarkable properties. Inspired by natural systems, there have been active efforts to understand design principles of natural materials and to synthesize bioinspired materials with outstanding properties. We have been inspired by natural structural materials with outstanding mechanical properties such as bone, coral reef, and wood that can adapt to their surrounding environment. For instance, bone can control mineral quantity proportional to the amount of stress from its sensing and mineral synthesis control mechanism. It becomes stronger in locations subjected to the higher mechanical loads, and vice versa. This leads to the formation of mechanically efficient structures for optimal biomechanical and energy-efficient performance. However, it has been a challenge for making synthetic materials that sense change of loading conditions and damage and change their structures and properties to adapt to new conditions. Moreover, materials degrade over time due to fatigue and damages accelerate the degradation rate, resulting in reduction in the lifetime of the materials and increase of the maintenance costs. If materials can repair damages, we can have more efficient use of materials with reduced associated costs. Synthesizing materials that can sense and adapt to mechanical loading and repair damages, can help us to use materials for a broad range of loading conditions with extended lifetime and reduced costs. To address the challenge, we are inspired by previous findings that bones are formed by mineralization of organic scaffolds using ions from blood. We report a material system that triggers mineral synthesis from simulated body fluids onto organic scaffolds upon mechanical loadings and/or damages so that the material can modulate its mechanical properties to adapt to loadings and regenerate upon damages. For example, we observed ~40% increase in the modulus of the material upon periodic loadings for 3 days. We also observed that the material could self-repair damages generated by removing ~5 μm thick minerals from the matrix, in 7 days. In addition, we demonstrate a simple way of making functionally graded material based on stress distribution within a material that results in graded deposition of minerals. We envision that our findings can open new strategies for making synthetic materials with self-adaptable mechanical properties and self-repair capability as well as tuning material properties on-demand.

Inbound open innovative strategies and eco-innovation in the Spanish food and beverage industry

The main purpose of this paper is to analyse the influence of open innovation strategies on eco-innovation by accounting for type of innovation (product vs. process) and novelty degree (radical vs. incremental) in the context of the Spanish food and beverage manufacturing industry over the period 2008–2014. We find that the breadth of external knowledge sources has a positive effect on firms’ adoption of most eco-innovations. However, the depth of these sources is only significant for process, product, and incremental eco-innovations related to a more efficient use of materials and energy, but not for radical ones. Moreover, our analysis confirms the presence of path dependence and the influence of both market demand and regulatory factors on adoption in general. Nevertheless, important differences with respect to the influence of embodied R&D, non-embodied R&D, training, external R&D, and cooperation on each type of eco-innovation are highlighted while controlling for past eco-innovation behaviour, size, and age of the firm.

Effect of Carbon Nanotube on Mechanical Properties of Hybrid Polymer Matrix Nano Composites at Different Weight Percentages

The necessity of efficient use of Materials is being observed strongly because of diminishing resources in the present times. The recent theoretical and experimental investigations indicate that Composite material has properties suitable for applications in many fields. Due to high specific strength and specific stiffness, fiber-reinforced composites have become attractive structural materials for majority of engineering applications, which demands materials with high strength to weight ratio for the best results. The mechanical behaviours were investigated experimentally for two systems of glass fiber reinforced epoxy composites with carbon Nanotube (CNTs) and without CNTs. An experimental campaign which involves 2 layers laminates were conducted in this study. A manufacturing process using hand lay-up method assisted by ultrasonic vibration was used to produce glass fiber-reinforced laminates with the epoxy matrix and with the CNT based epoxy matrix.

Manufacturing of carbide tools by Selective Laser Melting

Application fields of electrical discharge machining (EDM) are limited due to given process conditions. When producing structures of high aspect ratios or using multi-axis machining, removed particles assemble at the machining zone, leading to process instabilities and increasing tool wear. A promising approach to improve EDM process conditions is the utilization of flushing channels in the tool electrode. However, with increasing complexity of the electrode geometry and the local integration of the mentioned flushing channels, conventional electrode manufacturing reaches its limitations. By applying Selective Laser Melting (SLM), these limitations are eliminated. An additional benefit is the efficient use of material during SLM, where nearly no waste is produced, because remaining powder can be used for the next SLM-process. The appropriate integration of flushing channels, even for complicated electrode geometries, improves process conditions during EDM in a variety of applications, leading to a higher material removal rate VW and reduced tool wear ϑ compared to machining without flushing. Additionally, the number of required tool electrodes can be reduced, as SLM enables an efficient integration and miniaturization of all features in a single electrode, what results in a far more sustainable process chain. Of particular interest in the field of EDM is carbide. Because of its wear resistance and stability, it is an ideal electrode material, which is commonly applied in µEDM. Tungsten carbide-cobalt is representative for this group of materials, which is already used in tool manufacturing. Several tests show a general suitability of carbide tool electrodes made by SLM for EDM-processing. However, the SLM process parameters and the composition of the carbide-cobalt show significant impact to the EDM results. A lower proportion of cobalt leads to reduced material removal rates, whereas the level of tool wear remains at a similar level. In order to benefit from the advantages of additive manufactured carbide tool electrodes, this investigation aims at decreasing waste of material and the number of required tool electrodes.

Recent Developments in Nanomaterials for Geotechnical and Geoenvironmental Engineering

Nanotechnology has provided enormous benefits to the industrial and developed world. Most fields of knowledge have been tapping, using, and applying the advantages of nanotechnology to improve systems and living standards. This cannot be said for civil engineering and construction particularly geotechnical engineering. Actually, soil mechanics have been involved with nano scale dimensions and materials for a very long time, i.e. before the term nanotechnology and nanomaterials were coined. From the basic clay structure and the water molecules which give rise to soil plasticity/cohesiveness, geotechnical engineers were exposed to these phenomena since the early days of the subject. Currently, developments in nanotechnology and nanomaterials in geotechnical engineering has been limited to its use as an improvement and clean-up materials. Recent results have shown that the use of a small amount of nanomaterials (<1% of dry weight of the original soil) have resulted in significant change and improvement in soil properties. This is important since efficient use of materials is one of the facets of sustainability related to prolonging the life of our depleting natural resources. Experiences with nano-soil, nano-clay, nano-silica, nano-alumina, nano-magnesium, carbon nanotube and nanofibers, and nano-lime will all be discussed with respect to its use in soil improvement and soil remediation.

Recent Developments in Nanomaterials for Geotechnical and Geoenvironmental Engineering

Nanotechnology has provided enormous benefits to the industrial and developed world. Most fields of knowledge have been tapping, using, and applying the advantages of nanotechnology to improve systems and living standards. This cannot be said for civil engineering and construction particularly geotechnical engineering. Actually, soil mechanics have been involved with nano scale dimensions and materials for a very long time, i.e. before the term nanotechnology and nanomaterials were coined. From the basic clay structure and the water molecules which give rise to soil plasticity/cohesiveness, geotechnical engineers were exposed to these phenomena since the early days of the subject. Currently, developments in nanotechnology and nanomaterials in geotechnical engineering has been limited to its use as an improvement and clean-up materials. Recent results have shown that the use of a small amount of nanomaterials (<1% of dry weight of the original soil) have resulted in significant change and improvement in soil properties. This is important since efficient use of materials is one of the facets of sustainability related to prolonging the life of our depleting natural resources. Experiences with nano-soil, nano-clay, nano-silica, nano-alumina, nano-magnesium, carbon nanotube and nanofibers, and nano-lime will all be discussed with respect to its use in soil improvement and soil remediation.

Factors affecting the rural domestic waste generation

The current study was carried out to evaluate the quantity and quality of rural domestic waste generation and to identify the factors affecting it in rural areas of Khodabandeh county in Zanjan Province, Iran. Waste samplings consisted of 318 rural households in 11 villages. In order to evaluate the quality and quantity of the rural domestic waste, waste production was classified into 12 groups and 2 main groups of organic waste and solid waste. Moreover, kriging interpolation technique in ARC-GIS software was used to evaluate the spatial distribution of the generated domestic waste and ultimately multiple regression analysis was used to evaluate the factors affecting the generation of domestic waste. The results of this study showed that the average waste generated by each person was 0.588 kilograms per day. with the share of organic waste generated by each person being 0.409 kilograms per day and the share of solid waste generated by each person being 0.179 kilograms per day. The results from spatial distribution of waste generation showed a certain pattern in three groups and a higher rate of waste generation in the northern and northwestern parts, especially in the subdistrict. The results of multiple regression analysis showed that the households’ income, assets, age, and personal attitude are respectively the most important variables affecting waste generation. The housholds’ attitude and indigenous knowledge on efficient use of materials are also the key factors which can help reducing waste generation.

Shear strength of concrete interfaces with infra‐lightweight and foam concrete

Ceiling and floor slabs made of horizontal layers of regular and lightweight concrete could lead to an efficient use of materials. In this context, the bond between the different types of concrete is of particular importance. This paper shows the shear strength and failure mode of unreinforced concrete interfaces with high‐quality, lightweight concretes in dependence of different interface roughness. To achieve this, a regular and a structural lightweight concrete were bonded to an infra‐lightweight and a foam concrete. Small‐scale shear specimens consisting of five layers were manufactured and loaded to investigate their shear behavior as a whole. Both concrete and interface failures were detected in dependence of interface roughness and the type of core layer concrete. Additionally, it is shown that the observed behavior can be satisfactorily reproduced by a finite‐element model using the material parameters of concrete standard tests. The experimental and numerical investigations provide clearly defined interface parameters to design efficient load‐bearing slabs made of different concrete layers.

Perovskite and Organic Solar Cells Fabricated by Inkjet Printing: Progress and Prospects

AbstractInkjet printing (IJP) technology, adapted from home and office printing, has proven to be an essential research tool and industrial manufacturing technique in a wide range of printed electronic technologies, including optoelectronics. Its primary advantage over other deposition methods is the low‐cost and maskless on‐demand patterning, which offers unmatched freedom‐of‐design. Additional benefits include the efficient use of materials, contactless high‐resolution deposition, and scalability, enabling rapid translation of learning from small‐scale, laboratory‐based research into large‐scale industrial roll‐to‐roll manufacturing. In the development of organic solar cells (OSCs), IJP has enabled the printing of many of the multiple functional layers which comprise the complete cell as part of an additive printing scheme. Although IJP is only recently employed in perovskite solar cell (PeSC) fabrication, it is already showing great promise and is anticipated to find broader application with this class of materials. As OSCs and PeSCs share many common functional materials and device architectures, this review presents a progress report on the IJP of OSCs and PeSCs in order to facilitate knowledge transfer between the two technologies, with critical analyses of the challenges and opportunities also presented.

Application of eco-efficiency in the assessment of raw materials consumed by university restaurants in Brazil: A case study

The production of meals for collectivity is an important activity of the services segment. The concept of eco-efficiency prioritizes more efficient use of materials and energy, thus combining economic and environmental performance. The objective of this study was to propose and apply a procedure to measure and evaluate environmental performance under the eco-efficiency approach for the food production segment. The procedure was applied in five university restaurants of a Brazilian federal public university that served more than 1.5 million meals in 2012. Calculations for assessing eco-efficiency contemplated the inputs used considering the supply of energy in kilocalories and the financial figures for the environmental impacts in which the variables were selected from the water footprint and the amount of waste generated from food used. So far the concept of eco-efficiency was not applied to the food production segment to collectivities. Thus, this study is to contribute and fill that gap.

Material flow analysis of the residential building stock at the city of Rio de Janeiro

The extensive use of materials in building stocks contributes to the scarcity of natural resources and impacts from construction and demolition waste (CDW). Therefore, the concern with the efficient use of materials and CDW management made several countries conducted mapping, analysis and performance improvement in activities related to CDW using Material Flow Analysis (MFA). The city of Rio de Janeiro had a high urban development and building stock growth from the beginning of the last century, in which the amount of material consumed has not been documented. This study presents an MFA approach to assess the materials in-use and further flows of CDW from the residential building stock in the city of Rio de Janeiro. The material in-use was estimated from the extrapolation of the Material Intensities (MI) per different building types to the total constructed area in this city considering land occupation. The building types were modelled from the designs of typical buildings in Brazil. An analysis of urban development supported the estimation of buildings age and their remaining lifetime while national standards supported the time of replacement of building elements during the use phase. Results show that the stock in 2010 had about 78,828,770t of building material with MI between 2.58 and 0.74 t/m2; concrete and aggregates have the higher MI. The Use phase of the buildings will move about 9,807,690t of materials until 2090. These findings support further environmental impacts assessments and decision-making for planning CDW management and strategies for the efficient use of materials.

Airbus approach for F&DT stress justification of Additive Manufacturing parts

Additive Manufacturing (AM) is rapidly expanding in aviation due to the advantages it offers compared to conventional manufacturing routes. It allows the production of geometry optimized complex parts with an efficient use of material. However, in order to design reliable parts using this novel manufacturing route, the changes it involves in material properties, defects and shape of parts need to be understood. This paper presents an industrial structural analysis approach applied by AIRBUS to justify newly introduced AM parts on aircraft. Some areas for future development and improvement are also presented.

Dynamics effects on a wooden footbridge

The timber is the current trend for the construction of many footbridges because of many reasons as price, aesthetics and ecology. Most of these structures are designed using simple static models and massive elements. However, there are implemented more complicated constructions including suspended footbridge in Přibor in Czech Republic. This construction with efficient use of material is more susceptible to dynamic effect. The article describes monitoring of dynamics effects at the construction with result of installation dynamics dampers.

TYPES OF STEEL AND CONCRETE COMPOSITE CABLE SPACE FRAMES

Purpose. Modern terms of the construction generate the need to find new structures, including roof systems that would meet modern requirements. An important aspect in finding constructive solutions for new structures is the use of reliable and advanced materials. Considering this, the decision to develop the new space structures to a wide implementation in practice of domestic and foreign construction are relevant and perspective direction of building structures development. Methodology. Given the results of previously conducted theoretical research of existing types of space roof structures find promising areas of improvement or creation of new structures that should be devoid of weaknesses and imperfections of analogs and they should have an economic effect through rational use of materials. Findings. Types of steel and concrete composite cable space frames and structural features of its elements are developed and considered. The steel and concrete composite cable space frame is a completely new kind of space structure system that has the original structural concept and it was designed to cover large-span industrial and public buildings. The basic elements of that structure system are modular element of the bottom chord and space steel and concrete composite module that consists of tubular rods and reinforced concrete slab. All modular elements are made in the factory. With bottom chord modular elements and space steel and concrete composite modules can be assembled three types of longitudinal elements. It is the beam element, arched element and hanging element. Also with the modules can be assembled various structure system and their combinations. Number of space steel and concrete composite modules and bottom chord modular elements, which is needed to collect steel and concrete composite cable space frames, is determined by calculation and optimal designing. Recommended dimensions of the modular elements of the steel and concrete composite cable space frames are presented. Originality. The new efficient construction roofs that appointment for covering large-span buildings were developed by the author. Practical value. Developed steel and concrete composite grid-gable roofs are designed for industrial and civil construction. Applications of developed designs for the construction of large-span covering objects provides a significant economic benefit through the efficient use of materials.