3,085 research outputs found
Recyclable Architecture: Prefabricated and Recyclable Typologies
Buildings are being demolished without taking into the account the waste generated, and the housing shortage problem is getting more critical as cities are growing and the demand for built space and the use of resources are increasing. Architectural projects have been using prefabrication and modular systems to solve these problems. However, there is an absence of structures that can be disassembled and reused when the structure’s life ran its course. This paper presents three building prototypes of new recyclable architectural typologies: (i) a Slab prototype designed as a shelf structure where wooden housing modules can be plugged in and out, (ii) a Tower prototype allowing for an easy change of layout and use of different floors and (iii) a Demountable prototype characterized by the entire demountability of the building. These typologies combine modularity, flexibility, and disassembling to address the increasing demands for multi-use, re-usable and resource-efficient constructions. Design, drawings, plans, and 3D models are developed, tested and analyzed as a part of the research. The results show that the implementation of the recyclable architectural concept at the first design stage is feasible and realistic, and ensures the adaptation through time, increases life span, usability and the material reusability, while avoiding demolition, which in turn reduces the construction waste and, consequently, the CO2 emissions
Recyclable Architecture: Prefabricated and Recyclable Typologies
Buildings are being demolished without taking into the account the waste generated, and
the housing shortage problem is getting more critical as cities are growing and the demand for built
space and the use of resources are increasing. Architectural projects have been using prefabrication
and modular systems to solve these problems. However, there is an absence of structures that can
be disassembled and reused when the structure’s life ran its course. This paper presents three
building prototypes of new recyclable architectural typologies: (i) a Slab prototype designed as a
shelf structure where wooden housing modules can be plugged in and out, (ii) a Tower prototype
allowing for an easy change of layout and use of different floors and (iii) a Demountable prototype
characterized by the entire demountability of the building. These typologies combine modularity,
flexibility, and disassembling to address the increasing demands for multi‐use, re‐usable and
resource‐efficient constructions. Design, drawings, plans, and 3D models are developed, tested and
analyzed as a part of the research. The results show that the implementation of the recyclable
architectural concept at the first design stage is feasible and realistic, and ensures the adaptation
through time, increases life span, usability and the material reusability, while avoiding demolition,
which in turn reduces the construction waste and, consequently, the CO2 emissions
Determination of solids circulation rate through magnetic tracer tests
The present work proposes the determination of solids circulation rate in a freely circulating fluidized bed cold model by using a method that performs quantitative detection of fluid-dynamically similar ferromagnetic tracer particles (1). The method has already been proven for determination of particles residence time distribution with encouraging results (2). The method is based on inductance changes of a coil by effect of changes in the concentration of ferromagnetic particles in its core (Fig. 1). There is a direct correspondence between measured inductance and proportion of ferromagnetic material in the coil’s core. The tracer particles are fluid-dynamically consistent, the injection and sensing methods are non-invasive, the inductance signal has a high resolution and the measurement is performed continuously.
A cold flow model of a dual circulating fluidized bed (3) has been used to test the idea. The precise location of injection and sensing devices is presented in Fig. 2; this is the configuration proposed for the determination of the global circulation rate. A tracer injection pulse is assumed to be a perfect Dirac-delta function, and the response signal is measured at the outlet of the loop seal. These two signals are processed to determine the normalized residence time distribution curve, E(t), of the particles when flowing thought the loop seal (Eq. 1). Considering that the density of the bulk of particles is constant, for the mean residence time, Eq. 2 is valid. Eq. 3. indicates the variance of E(t), it is, the degree of dispersion around the mean.
Under the assumption that the loop seal is maintained at conditions of minimum fluidization, regardless of the circulation rate and the conditions inside the reactors, the pressure difference is given by Eq. 4, which in turn allows the correlation between global circulation rate and mean residence time as shown in Eq. 5. At higher circulation rates and/or high accumulation of solids in the downcomer, the fluidization conditions might diverge from minimum fluidization, and the pressure drop per length unit might vary. This variation is proportional to the change in the variance of the residence time distribution curve, and can be quantified.
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Metabolic engineering of Saccharomyces cerevisiae for overproduction of triacylglycerols
Triacylglycerols (TAGs) are valuable versatile compounds that can be used as metabolites for nutrition and health, as well as feedstocks for biofuel production. Although Saccharomyces cerevisiae is the favored microbial cell factory for industrial production of biochemicals, it does not produce large amounts of lipids and TAGs comprise only ~1% of its cell dry weight. Here, we engineered S. cerevisiae to reorient its metabolism for overproduction of TAGs, by regulating lipid droplet associated-proteins involved in TAG synthesis and hydrolysis. We implemented a push-and-pull strategy by overexpressing genes encoding a deregulated acetyl-CoA carboxylase, ACC1S659A/S1157A (ACC1**), as well as the last two steps of TAG formation: phosphatidic phosphatase (PAH1) and diacylglycerol acyltransferase (DGA1), ultimately leading to 129 mg∙gCDW−1 of TAGs. Disruption of TAG lipase genes TGL3, TGL4, TGL5 and sterol acyltransferase gene ARE1 increased the TAG content to 218 mg∙gCDW−1. Further disruption of the beta-oxidation by deletion of POX1, as well as glycerol-3-phosphate utilization through deletion of GUT2, did not affect TAGs levels. Finally, disruption of the peroxisomal fatty acyl-CoA transporter PXA1 led to accumulation of 254 mg∙gCDW−1. The TAG levels achieved here are the highest titer reported in S. cerevisiae, reaching 27.4% of the maximum theoretical yield in minimal medium with 2% glucose. This work shows the potential of using an industrially established and robust yeast species for high level lipid production
Rational gRNA design based on transcription factor binding data
The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system has become a standard tool in many genome engineering endeavors. The endonuclease-deficient version of Cas9 (dCas9) is also a powerful programmable tool for gene regulation. In this study, we made use of Saccharomyces cerevisiae transcription factor (TF) binding data to obtain a better understanding of the interplay between TF binding and binding of dCas9 fused to an activator domain, VPR. More specifically, we targeted dCas9-VPR toward binding sites of Gcr1-Gcr2 and Tye7 present in several promoters of genes encoding enzymes engaged in the central carbon metabolism. From our data, we observed an upregulation of gene expression when dCas9-VPR was targeted next to a TF binding motif, whereas a downregulation or no change was observed when dCas9 was bound on a TF motif. This suggests a steric competition between dCas9 and the specific TF. Integrating TF binding data, therefore, proved to be useful for designing guide RNAs for CRISPR interference or CRISPR activation applications
New records and range extension of a Brazilian Amazon white-sand endemic species: Roraimaea aurantiaca Struwe, S.Nilsson & V.A.Albert (Gentianaceae)
Roraimaea aurantiaca Struwe, S.Nilsson & V.A.Albert, a white-sand endemic species, was previously known from only two specimens collected in Roraima state, Brazil. Our new field collections and re-identified herbarium specimens expand this species’ distribution and include the first records from the Brazilian state of Amazonas. Based on this effort, we present a distribution map, preliminary conservation status of Endangered, the first photographs of living plants, and an updated morphological description. This study aggregates new information on the flora of the northern Amazon Basin, in addition to discussing conservation of R. aurantiaca
Advancing biotechnology with CRISPR/Cas9: recent applications and patent landscape
Clustered regularly interspaced short palindromic repeats (CRISPR) is poised to become one of the key scientific discoveries of the twenty-first century. Originating from prokaryotic and archaeal immune systems to counter phage invasions, CRISPR-based applications have been tailored for manipulating a broad range of living organisms. From the different elucidated types of CRISPR mechanisms, the type II system adapted from Streptococcus pyogenes has been the most exploited as a tool for genome engineering and gene regulation. In this review, we describe the different applications of CRISPR/Cas9 technology in the industrial biotechnology field. Next, we detail the current status of the patent landscape, highlighting its exploitation through different companies, and conclude with future perspectives of this technology
ENERGIA FOTOVOLTAICA- APLICAÇÃO SISTEMA ON GRID EM RESIDÊNCIA
The theme deals with the power generation system through sunlight. The work presents the explanation of terms used in electrical engineering that are used in the photovoltaic system. It also contains data on the increase of this power generation system over the years in Brazil, as well as provides information on how this system is installed, the types of installations that can be made (ongrid (grid-tie) or offgrid) and the types of inverters that can be used. Finally, an example of the actual application of an ongrid photovoltaic system, installed in a residence using a micro inverter, is presented.El tema trata sobre el sistema de generación de energía a través de la luz solar. El trabajo presenta la explicación de los términos utilizados en ingeniería eléctrica que se utilizan en el sistema fotovoltaico. También contiene datos sobre el aumento de este sistema de generación de energía a lo largo de los años en Brasil, así como proporciona información sobre cómo se instala este sistema, los tipos de instalaciones que se pueden realizar (ongrid (grid-tie) o offgrid) y los tipos de inversores que se pueden utilizar. Finalmente, se presenta un ejemplo de la aplicación real de un sistema fotovoltaico ongrid, instalado en una residencia utilizando un micro inversor.O tema trata sobre o sistema de geração de energia através da luz solar. O trabalho apresenta a explicação de termos utilizados na engenharia elétrica que são utilizados no sistema fotovoltaico. Além disso contém dados sobre o aumento desse sistema de geração de energia ao longo dos anos no Brasil, bem como fornece informações de como é feita a instalação deste sistema, os tipos de instalações que podem ser feitas (ongrid (grid-tie) ou offgrid) e os tipos de inversores que podem ser utilizados. Por fim é apresentado um exemplo de aplicação real de um sistema fotovoltaico ongrid, instalado em uma residência utilizando um micro inversor.O tema trata sobre o sistema de geração de energia através da luz solar. O trabalho apresenta a explicação de termos utilizados na engenharia elétrica que são utilizados no sistema fotovoltaico. Além disso contém dados sobre o aumento desse sistema de geração de energia ao longo dos anos no Brasil, bem como fornece informações de como é feita a instalação deste sistema, os tipos de instalações que podem ser feitas (ongrid (grid-tie) ou offgrid) e os tipos de inversores que podem ser utilizados. Por fim é apresentado um exemplo de aplicação real de um sistema fotovoltaico ongrid, instalado em uma residência utilizando um micro inversor
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