Quality evaluation of carbonaceous industrial by-products and its effect on properties of autoclave aerated concrete

Quality evaluation of carbonaceous industrial by-products and its effect on properties of autoclave aerated concrete / E. V. Fomina [et al.] // IOP Conf. Series: Materials Science and Engineering. - 2018. - Vol.327. - 042033.. Argillite is a carbonaceous industrial by-product that is a potential source in environmentally friendly and source-saving construction industry. In this research, chemical and mineral composition as well as particle size distribution of argillite were studied and used to develop autoclave aerated concrete as partial substitute of quartz sand. Effect of the argillite as a mineral admixture in autoclave aerated concrete was investigated in terms of compressive and tensile strength, density, heat conductivity etc. The obtained results demonstrated an efficiency of argillite as an energy-saving material in autoclave construction composite

Fungi in Flux | Designing Regenerative Materials and Products with Mycelium

As the world grapples with the escalating crisis of climate threats and environmental degradation, this research delves into the synergistic potential of design and biology, developing safe and sustainable materials for applications in prototyping, furniture and interior design. Harnessing the power of a unique organism - fungi, the study proposes an accessible, efficient, and resilient material resource system. It utilizes local waste streams and mycelium (the vegetative part of fungi) to grow functional structures. An experimental and small-scale protocol is modeled by testing bio-fabrication and bio-printing methods. The composites\u27 performance qualities and characteristics are evaluated through mechanical testing and a survey of experiential attributes. A series of workshops introduced participants to the creative possibilities of integrating myco-materials into their practice, leading to insights and possibilities in new processes and products. To foster a deeper understanding of sustainability, the carbon footprint and ecological impact of these materials are examined. Envisioning a paradigm shift in industrial ecology, the proposed ideas reduce dependence on non-biodegradable, toxic, and harmful materials. With the principles of biology and design, this work hopes to transcend the trajectory of conventional materials - particularly plastics, and move toward a regenerative future

Valorization of phosphogypsum in cement-based materials: limits and potential in eco-efficient construction

Phosphogypsum (PG) is a type of synthetic gypsum generated during the production of phosphoric acid. Each ton of phosphoric acid generates 5 tons of phosphogypsum. This industrial process has caused significant environmental problems worldwide. After an extensive literature review, it was possible to verify that both sedimentary and igneous PG can be used as in materials building components. The use of PG up to 50% meets the limits required for index I, with a radioactivity equivalent to radio-226 and a concentration of radon-222. The data found on bricks (0,11-0,41 Bq m-2 h-1) and plate (0,16-0,41 Bq m-2 h -1) show a lower exhalation rate. It is also found that calcination contributes to the reduction of PG impurities and to the of mechanical strength increase. Mortars and concretes produced with PG-based cementitious systems cementitious systems based on PG achieve high strength (60 MPa, 70 MPa, 80 MPa) and meet the technical feasibility criteria of European standards EN 998-1, EN 998-2, EN 13813, Eurocode 1992 and the American standard ASTM C270. The setting time is influenced by the mineral phase of the PG. It is concluded that cementitious materials produced from phosphogypsum are technically viable and achieve a satisfactory performance. It is possible to advance the following lines: PG-based concrete with high performance, PG-based hydration cement, stabilized mortar, PG-based concrete with high workability and studies about chloride ingress, carbonation, sulfate attack and acid attack in PG-based concrete

An Enhancement of the Properties of Cellulose Nanofibril Composites for Biomedical Applications

The use of plastics has increased significantly within the past few years. The versatile properties within this material set have enabled them to be adopted into many different industries. They tend to possess excellent vapor and liquid barrier properties, adjustable mechanical properties, and can be designed for specific heating and electrical applications. One specific industry that has capitalized on plastics is the medical industry. Since the COVID-19 pandemic, a class of subset plastic materials, single-use plastics, have been utilized. These single-use devices are typically used for a short time and quickly discarded. These items can range from masks to gloves and even IV bags. While these materials possess properties that are ideal for their design, they are over-engineered for their purpose. They are generally used within 24 hours but are sometimes designed to last 100s years. Not only that, but they are difficult to dispose of. Incineration can release greenhouse gases into the air, mechanical degradation can produce microplastics, and landfilling is a temporary solution that will create future complications. Therefore, alternative single-use plastic materials must be designed to possess properties similar to current ones but can naturally degrade in a much shorter period. Cellulose nanofibrils (CNF) emerge as a crucial solution to the single-use plastic problem in the medical industry. Among the many biodegradable materials under research, CNF\u27s sustainability, biocompatibility, and biodegradability make it a compelling candidate for biomedical research. Its unique geometric and surface properties make it chemically and mechanically versatile, including hydrophilicity, high mechanical strength, and moderate porosity in bulk formulations. These properties have led to extensive research into the potential of dense CNF-based solid composites in healthcare-related applications, from disposable surgical tools to resorbable implants. The urgency of finding a solution to the single-use plastic problem in the medical industry cannot be overstated, and CNF offers a promising path forward. Despite significant progress and even some commercial interest, several key unknowns remain that must be addressed to fully realize the potential of CNF as an alternative to single-use plastics in the medical industry. The rehydration and degradability of CNF when introduced to water are current complications within the material. One potential method is to use a crosslinking agent within the CNF to address this. More potential complications are the low dispersion of minerals throughout the material and low cell viability. To overcome this, an enhanced dispersion method of a biological mineral into CNF will be designed and tested. This will alleviate the current lack of mineral dispersion while also expanding the cell viability of the material. Bioglass will also be added to CNF to explore further and enhance the cell viability of CNF while attempting to retain the desired mechanical properties of the dried material. Finally, adapting a standard metal fabrication process will try to reduce the overall internal strain that CNF naturally possesses. This ongoing research and experimentation demonstrate the commitment to creating a more desired and suitable alternative product to medical-grade plastics

Desenvolvimento de técnicas de produção de Codium tomentosum em substratos artificiais

ds, due to their chemical composition, which exhibit multiple bioactive health effects and high potential to be used in many industries. Codium tomentosum is a green and perennial macroalgae, which can reproduce itself by sexual and asexual reproduction. This alga reveals high potential to be used in cosmetics and directly on human’s diet due to its nutritional composition and content in bioactive compounds. Inserted in an IMTA (Integrated Multitrophic Aquaculture) system, the aim of this work consists on the evaluation of the cultivation potential of Codium tomentosum attached to different types of substratum, colonization methods and different mediums. Five trials were made in order to determine key aspects of Codium tomentosum cultivation attached to the substrates, to evaluate and optimize the cultivation of C. tomentosum fixed on artificial substrates, in contrast to the freefloating method currently used at ALGAplus. In the first two trials, the substrates were submitted to colonization methods with a certain density. In the last three trials, the substrates were also submitted to both colonization methods with different density, kept in the maternity with controlled conditions and then transferred to the exterior, to an earth pond or to an artificial tank. In the first and second trials, the substrates tested were rope, plastic web, brick, rough rock, and tile using a passive seeding method with low density. However, it was not possible to cultivate Codium attached to them. After those results, the substrates used were changed to substrates already tested to cultivate other algae species attached to them, kuralon line. In this third trial, this was the substrate tested using a passive seeding method with medium density. Again, it was not possible to cultivate Codium. After this result, the density was increased to high values and another method of seeding, aspersion, was tested along the passive seeding method on kuralon line and biodegradable stripes. In the fourth trial, the Codium started to grow but when were transferred to the outside tanks got contaminated by other algae. With these results, another trial was performed using kuralon line where the density was maintained and in the second step of the cultivation the substrates were transferred to an artificial tank. In this trial, the cultivation of Codium attached to the substrates was achieved when subjected to the aspersion method. According to the results of the five trials made, the substrate used with the best results was the kuralon line, the best density was high and the best colonization method was the aspersion method.Nas últimas décadas, tem havido um interesse crescente nas algas marinhas, devido à sua composição química, que pode ter múltiplos efeitos bioativos para a saúde e alto potencial para uso em muitas indústrias. Codium tomentosum é uma macroalga verde e perene, que se pode reproduzir sexuadamente e assexuadamente. Esta alga revela alto potencial para ser utilizada em cosméticos e diretamente na dieta humana devido à sua composição nutricional e conteúdo em compostos bioativos. Inserido num sistema AMTI (Aquacultura Multi-Trófica Integrada), o objetivo deste trabalho consiste na avaliação do cultivo de Codium tomentosum ligado a diferentes tipos de substrato, meios de cultivo e métodos de colonização. Foram feitos cinco ensaios com o intuito de avaliar e otimizar o cultivo fixo em substratos artificiais de Codium tomentosum, ao contrário do método “freefloating“ utilizado atualmente na empresa ALGAplus. Nos dois primeiros ensaios, os substratos foram submetidos ao método passivo de colonização com densidades diferentes de alga. Nos últimos três ensaios, os substratos foram submetidos a dois métodos de colonização (método passivo e método de aspersão) com diferentes densidades, mantidos na maternidade em condições controladas e depois transferidos para o exterior, para um tanque de terra ou para um tanque artificial. Os dois primeiros ensaios foram feitos usando o método passivo com materiais reutilizados, como corda, rede de plástico, tijolo, rocha e telha, utilizando soluções de Codium com densidades diferentes. No entanto não foi possível cultivar Codium anexado a nenhum dos substratos testados. Após estes resultados, os substratos utilizados foram trocados por substratos já testados para o cultivo de outras espécies de algas, o fio kuralon. Assim no terceiro ensaio, foi testado este substrato pelo método de submersão com densidade média. Também neste ensaio não foi possível cultivar Codium. No ensaio seguinte a densidade foi duplicada para uma densidade alta e outro método de colonização (aspersão) foi testado juntamente com o método de submersão em fio kuralon e tiras biodegradáveis. Neste ensaio, no início a alga começou a crescer, mas depois de transferidos para o tanque de terra ficaram contaminados por outras algas. Com esses resultados, no ensaio seguinte a densidade foi mantida, mas foi feita apenas em fio kuralon e na segunda etapa do cultivo os substratos foram transferidos para o exterior, mas para um tanque artificial. No último ensaio, foi conseguido o cultivo de Codium anexado ao fio kuralon quando submetido ao método de aspersão. De acordo com os resultados dos ensaios realizados, o substrato utilizado com melhores resultados foi o fio kuralon com uma densidade inicial alta e o melhor método de colonização é o método de aspersãoMestrado em Biotecnologi

Integrating Building Functions into Massive External Walls

Well into the twentieth century, brick and stone were the materials used. Bricklaying and stonemasonry were the construction technologies employed for the exterior walls of virtually all major structures. However, with the rise in quality of life, the massive walls alone became incapable of fulfilling all the developed needs. Adjacent systems and layers had then to be attached to the massive layer. Nowadays, the external wall is usually composed of a layered construction. Each external wall function is usually represented by a separate layer or system. The massive layer of the wall is usually responsible for the load-bearing function. Traditional massive external walls vary in terms of their external appearance, their composition and attached layers. However, their design and construction process is usually a repeated process. It is a linear process where each discipline is concerned with a separate layer or system. These disciplines usually take their tasks away and bring them back to be re-integrated in a layered manner. New massive technologies with additional function have recently become available. Such technologies can provide the external wall with other functions in addition to its load-bearing function. The purpose of this research is to map the changes required to the traditional design and construction process when massive technologies with additional function are applied in external walls. Moreover, the research aims at assessing the performance of massive solutions with additional function when compared to traditional solutions in two different contexts, the Netherlands and Egypt. Through the analysis of different additional function technologies in external walls, a guidance scheme for different stakeholders is generated. It shows the expected process changes as related to the product level and customization level. Moreover, the research concludes that the performance of additional insulating technologies, and specifically Autoclaved Aerated Concrete can provide a better construction compared to the traditional external wall construction of the Netherlands and Egypt

Technologies for Beneficial Microorganisms Inocula Used as Biofertilizers

The increasing need for environmentaly friendly agricultural practices is driving the use of fertilizers based on beneficial microorganisms. The latter belong to a wide array of genera, classes, and phyla, ranging from bacteria to yeasts and fungi, which can support plant nutrition with different mechanisms. Moreover, studies on the interactions between plant, soil, and the different microorganisms are shedding light on their interrelationships thus providing new possible ways to exploit them for agricultural purposes. However, even though the inoculation of plants with these microorganisms is a well-known practice, the formulation of inocula with a reliable and consistent effect under field conditions is still a bottleneck for their wider use. The choice of the technology for inocula production and of the carrier for the formulation is key to their successful application. This paper focuses on how inoculation issues can be approached to improve the performance of beneficial microorganisms used as a tool for enhancing plant growth and yield

Toward the development of robust self-healing concrete using vegetative microorganisms

textRobust self-healing concrete, which requires less maintenance and repair throughout its service life than ordinary concrete, can be used for the development of sustainable infrastructure. Li and Herbert stated that a true robust self-healing concrete should meet six critical robustness criteria; the self-healing mechanism should 1. possess a long shelf life comparable to the service life of the structure; 2. be pervasive throughout the material; 3. exhibit good quality as indicated by the percentage of recovery provided; 4. be reliable; 5. be versatile in various environmental conditions; 6. be repeatable over the service life of the structure; Although many approaches can be used to promote self-healing in cement-based materials, use of biomineralization (the process by which organisms stimulate the formation of minerals) for this purpose has generated considerable interest. Previous research on biomineralization, specifically microbial-induced calcium carbonate precipitation, suggested that this process can improve durability and remediate cracks in concrete. This thesis presents the results of a multifaceted research program undertaken to evaluate the robustness of microbial concrete containing vegetative Sporosarcina pasteurii. Specifically, the criteria of versatility and quality were assessed. Versatility was evaluated by examining the influence of environmental factors on the polymorph selection process of calcium carbonate precipitated due to the activity of S. pasteurii, and it was determined that calcium concentration and overall ionic strength impacted morphology as did pH and substrate mineralogy. Another aspect of versatility that was addressed was the ability of vegetative S. pasteurii to remain viable and metabolically active when subjected to harsh conditions that might occur inside concrete including heat, high pH, and nutrient depletion. Quality was assessed by comparing properties of biogenic calcium carbonate and synthetic calcium carbonate, and it was determined that the former exhibited greater kinetic and thermodynamic stability than the latter. Quality was further examined by determining the ability of biomineralization to heal flexural cracks in mortar and provide strength recovery. Finally, the chemical constituents of the growth medium for S. pasteurii were optimized to mitigate severe retardation in cement hydration kinetics that has been observed when vegetative bacteria suspended in growth medium are added to cement, which improved the feasibility of microbial concrete.Civil, Architectural, and Environmental Engineerin