As agroindústrias familiar rural surgem a partir de sonhos empreendedores ou como forma de agregar valor para melhorar a renda. Esta pesquisa teve como objetivo analisar a viabilidade econômica e o ...custo de produção de um empreendimento agroindustrial familiar da região Central de Rondônia. Para tal, elaborou-se um instrumental, tendo como base o princípio da ferramenta FOFA, fez-se oficinas participativas e análise de materiais secundários. O custo da construção representou 36,9%. Já aquisição dos equipamentos e veículo utilitário representou 49,9% dos investimentos. Já o principal item do custo variável é o leite, principal matéria prima com 22,7%. Neste sentido, para produzir um litro de leite pasteurizado, o custo fixo de R$ 0,41, o variável de R$ 2,67 totalizando R$ 3,08 que gera um prejuízo de 6,5%, pois é comercializando à R$ 2,88. Já o iogurte, tem custo fixo de R$ 0,44, o variável de R$ 4,30 totalizando R$ 4,74 que gera um lucro de 43,5%, pois é comercializando à R$ 6,80. Conclui-se que a agroindústria é de pequeno porte, com pequena escala de produção, atendendo o mercado local, com parâmetros rígidos de controle sanitário, de acordo com o PROVE/RO e a produção se dá com uso de tecnologias. Quanto à gestão, encontram-se dificuldades em controlar os custos de produção. Diante disso, fica evidente que a produção agroindustrial necessita de gestão profissionalizada, ou seja, os produtores devem buscar formação para melhor controle de sua atividade, otimizando os recursos de modo a garantir a sustentabilidade do empreendimento.
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CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy ...on a large scale. This promising technology can be achieved in a one-step excitation system using a single photocatalyst or
via
a Z-scheme process based on a pair of photocatalysts. Ideally, such photocatalysis will proceed with charge separation and transport unaffected by recombination and trapping, and surface catalytic processes will not involve undesirable reactions. This review summarizes the basics of overall water splitting
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both one-step excitation and Z-scheme processes, with a focus on standard methods of determining photocatalytic performance. Various surface engineering strategies applied to photocatalysts, such as cocatalyst loading, surface morphology control, surface modification and surface phase junctions, have been developed to allow efficient one-step excitation overall water splitting. In addition, numerous visible-light-responsive photocatalysts have been successfully utilized as H
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-evolution or O
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-evolution photocatalysts in Z-scheme overall water splitting. Prototype particulate immobilization systems with photocatalytic performances comparable to or drastically higher than those of particle suspension systems suggest the exciting possibility of the large-scale production of low-cost renewable solar hydrogen.
Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale.
The existing literature on the construction costs of nuclear power reactors has focused almost exclusively on trends in construction costs in only two countries, the United States and France, and ...during two decades, the 1970s and 1980s. These analyses, Koomey and Hultman (2007); Grubler (2010), and Escobar-Rangel and Lévêque (2015), study only 26% of reactors built globally between 1960 and 2010, providing an incomplete picture of the economic evolution of nuclear power construction. This study curates historical reactor-specific overnight construction cost (OCC) data that broaden the scope of study substantially, covering the full cost history for 349 reactors in the US, France, Canada, West Germany, Japan, India, and South Korea, encompassing 58% of all reactors built globally. We find that trends in costs have varied significantly in magnitude and in structure by era, country, and experience. In contrast to the rapid cost escalation that characterized nuclear construction in the United States, we find evidence of much milder cost escalation in many countries, including absolute cost declines in some countries and specific eras. Our new findings suggest that there is no inherent cost escalation trend associated with nuclear technology.
•Comprehensive analysis of nuclear power construction cost experience.•Coverage for early and recent reactors in seven countries.•International comparisons and re-evaluation of learning.•Cost trends vary by country and era; some experience cost stability or decline.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
We show how to build a multiscale entanglement renormalization ansatz (MERA) representation of the ground state of a many-body Hamiltonian H by applying the recently proposed tensor network ...renormalization G. Evenbly and G. Vidal, Phys. Rev. Lett. 115, 180405 (2015) to the Euclidean time evolution operator e(-βH) for infinite β. This approach bypasses the costly energy minimization of previous MERA algorithms and, when applied to finite inverse temperature β, produces a MERA representation of a thermal Gibbs state. Our construction endows tensor network renormalization with a renormalization group flow in the space of wave functions and Hamiltonians (and not merely in the more abstract space of tensors) and extends the MERA formalism to classical statistical systems.
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Additive manufacturing is a recent trend in production processes owing to its many benefits. It can be defined as the process of producing parts through the deposition of material in a layer-by-layer ...fashion. It has been a topic of intense study and review by many researchers. In this work, a comprehensive review pertaining to additive manufacturing has been accomplished. The evolution of additive manufacturing as a prominent technology and its various phases are discussed. The importance of part orientation, build time estimation, and cost computation has also been reviewed. The remarkable aspect of this work is the identification of problems associated with different additive manufacturing methods. Because of the imperfections in additive manufacturing, its hybridization with other methods, such as subtractive manufacturing, has been emphasized. This review will help readers understand the different aspects of additive manufacturing and explore new avenues for future research.
A vision is presented on 3D printing with concrete, considering technical, economic and environmental aspects. Although several showcases of 3D printed concrete structures are available worldwide, ...many challenges remain at the technical and processing level. Currently available high-performance cement-based materials cannot be directly 3D printed, because of inadequate rheological and stiffening properties. Active rheology control (ARC) and active stiffening control (ASC) will provide new ways of extending the material palette for 3D printing applications. From an economic point of view, digitally manufactured concrete (DFC) will induce changes in the stakeholders as well as in the cost structure. Although it is currently too ambitious to quantitatively present the cost structure, DFC presents many potential opportunities to increase cost-effectiveness of construction processes. The environmental impact of 3D printing with concrete has to be seen in relation to the shape complexity of the structure. Implementing structural optimization as well as functional hybridization as design strategies allows the use of material only where is structurally or functionally needed. This design optimization increases shape complexity, but also reduces material use in DFC. As a result, it is expected that for structures with the same functionality, DFC will environmentally perform better over the entire service life in comparison with conventionally produced concrete structures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides constitutes one of the most powerful and atom economical methods for the enantioselective construction of pyrrolidines. This ...article highlights the recent developments in this area, with special focus on contributions improving the structural scope at the dipolarophile and azomethine ylide partners.
The problem of providing privacy, in the private information retrieval (PIR) sense, to users requesting data from a distributed storage system (DSS), is considered. The DSS is coded by an ...<inline-formula> <tex-math notation="LaTeX">(n,k,d) </tex-math></inline-formula> maximum distance separable code to store the data reliably on unreliable storage nodes. Some of these nodes can be spies which report to a third party, such as an oppressive regime, which data is being requested by the user. An information theoretic PIR scheme ensures that a user can satisfy its request while revealing no information on which data is being requested to the nodes. A user can trivially achieve PIR by downloading all the data in the DSS. However, this is not a feasible solution due to its high communication cost. We construct PIR schemes with low download communication cost. When there is <inline-formula> <tex-math notation="LaTeX">b=1 </tex-math></inline-formula> spy node in the DSS, in other words, no collusion between the nodes, we construct PIR schemes with download cost <inline-formula> <tex-math notation="LaTeX">\frac {1}{1-R} </tex-math></inline-formula> per unit of requested data (<inline-formula> <tex-math notation="LaTeX">R=k/n </tex-math></inline-formula> is the code rate), achieving the information theoretic limit for linear schemes. The proposed schemes are universal since they depend on the code rate, but not on the generator matrix of the code. Also, if <inline-formula> <tex-math notation="LaTeX">b\leq n-\delta k </tex-math></inline-formula> nodes collude, with <inline-formula> <tex-math notation="LaTeX">\delta =\lfloor {\frac {n-b}{k}}\rfloor </tex-math></inline-formula>, we construct linear PIR schemes with download cost <inline-formula> <tex-math notation="LaTeX">\frac {b+\delta k}{\delta } </tex-math></inline-formula>.
An oxidant-free dehydrogenative sulfonylation of α-methyl-styrene derivatives was developed for the construction of allylic sulfones by using eosin Y as a photosensitizer in conjunction with a ...cobaloxime catalyst. The process features a low-cost metal catalyst and atom economy, which provides an appealing strategy for future synthetic chemistry.
Earth orbiting satellites come in a wide range of shapes and sizes to meet a diverse variety of uses and applications. Large satellites with masses over 1000 kg support high-resolution remote sensing ...of the Earth, high bandwidth communications services, and world-class scientific studies but take lengthy developments and are costly to build and launch. The advent of commercially available, high-volume, and hence low-cost microelectronics has enabled a different approach through miniaturization. This results in physically far smaller satellites that dramatically reduce timescales and costs and that are able to provide operational and commercially viable services. This paper charts the evolution and rise of small satellites from being an early curiosity with limited utility through to the present where small satellites are a key element of modern space capabilities.
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