Demonstration of Solar Heating and Cooling System using Sorption Integrated Solar Thermal Collectors

Producing cost-competitive small and medium-sized solar cooling systems is currently a significant challenge. Due to system complexity, extensive engineering, design and equipment costs; the installation costs of solar thermal cooling systems are prohibitively high. In efforts to overcome these limitations, a novel sorption heat pump module has been developed and directly integrated into a solar thermal collector. The module comprises a fully encapsulated sorption tube containing hygroscopic salt sorbent and water as a refrigerant, sealed under vacuum with no moving parts. A 5.6m2 aperture area outdoor laboratory-scale system of sorption module integrated solar collectors was installed in Stockholm, Sweden and evaluated under constant re-cooling and chilled fluid return temperatures in order to assess collector performance. Measured average solar cooling COP was 0.19 with average cooling powers between 120 and 200 Wm-2 collector aperture area. It was observed that average collector cooling power is constant at daily insolation levels above 3.6 kWhm-2 with the cooling energy produced being proportional to solar insolation. For full evaluation of an integrated sorption collector solar heating and cooling system, under the umbrella of a European Union project for technological innovation, a 180 m2 large-scale demonstration system has been installed in Karlstad, Sweden. Results from the installation commissioned in summer 2014 with non-optimised control strategies showed average electrical COP of 10.6 and average cooling powers between 140 and 250 Wm-2 collector aperture area. Optimisation of control strategies, heat transfer fluid flows through the collectors and electrical COP will be carried out in autumn 2014.

Evaluation of a thermally driven heat pump for solar heating and cooling applications

Exploiting solar energy technology for both heating and cooling purposes has the potential of meeting an appreciable portion of the energy demand in buildings throughout the year. By developing an integrated, multi-purpose solar energy system, that can operate all twelve months of the year, a high utilisation factor can be achieved which translates to more economical systems. However, there are still some techno-economic barriers to the general commercialisation and market penetration of such technologies. These are associated with high system and installation costs, significant system complexity, and lack of knowledge of system implementation and expected performance. A sorption heat pump module that can be integrated directly into a solar thermal collector has thus been developed in order to tackle the aforementioned market barriers. This has been designed for the development of cost-effective pre-engineered solar energy system kits that can provide both heating and cooling. This thesis summarises the characterisation studies of the operation of individual sorption modules, sorption module integrated solar collectors and a full solar heating and cooling system employing sorption module integrated collectors. Key performance indicators for the individual sorption modules showed cooling delivery for 6 hours at an average power of 40 W and a temperature lift of 21°C. Upon integration of the sorption modules into a solar collector, measured solar radiation energy to cooling energy conversion efficiencies (solar cooling COP) were between 0.10 and 0.25 with average cooling powers between 90 and 200 W/m2 collector aperture area. Further investigations of the sorption module integrated collectors implementation in a full solar heating and cooling system yielded electrical cooling COP ranging from 1.7 to 12.6 with an average of 10.6 for the test period. Additionally, simulations were performed to determine system energy and cost saving potential for various system sizes over a full year of operation for a 140 m2 single-family dwelling located in Madrid, Spain. Simulations yielded an annual solar fraction of 42% and potential cost savings of €386 per annum for a solar heating and cooling installation employing 20m2 of sorption integrated collectors.

Estratégias de inovação e mudança organizacional: o Programa de Racionalização e competitividade da Caixa Econômica Federal

A presente dissertação tem por objetivo identificar - por meio do estudo de caso da implantação do PRC - Programa de Racionalização e Competitividade na Caixa Econômica Federal - se existem padrões de respostas e soluções organizacionais que possam ensejar um modelo básico de inovação e mudança organizacional tipicamente brasileiro. Considerando que o turbulento ambiente empresarial brasileiro desenvolveu empresas altamente adaptáveis às provocações ambientais por meio de diversos modelos de gestão de mudança organizacional, o presente estudo num primeiro momento faz uma revisão da literatura sobre o tema. Em seguida, descreve o contexto e os diversos modelos de gestão experimentados pela CAIXA, no período de 1989 a 1998, visando registrar e sistematizar informações que poderão permitir que se vislumbre, ao longo do tempo, traços comuns que possam caracterizar esse típico modelo de inovação e mudança organizacional brasileiro. Os resultados obtidos da pesquisa de campo, respaldados pelo exame bibliográfico, permitiu concluir que o processo de mudança experimentado pela organização em virtude da implementação do programa foi despertado tanto por variáveis do contexto interno quanto do contexto externo, com semelhante intensidade. Adicionalmente, pode-se concluir que houve mais facilidade da organização em lidar com as perspectivas estratégica, estrutural e humana, e mais dificuldade em lidar com as perspectivas tecnológica, cultural e política. Confirma-se, portanto, que algumas perspectivas do processo de mudança experimentado pela CAIXA denotaram práticas de inovação organizacional e que, entretanto, outras perspectivas não puderam ser reproduzidas de modo confiável, em uma escala significativa a custos razoáveis.

Fidelidade e governança corporativa em cooperativas: um estudo empírico com as cooperativas paulistas

Cláusulas de fidelidade e políticas de fidelização são elementos comuns nos debates sobre como intensificar o comprometimento dos associados com sua cooperativa. A literatura acadêmica já apresentou diversos fatores que podem influenciar o comprometimento/fidelidade dos associados. Entretanto, poucas respostas foram dadas quanto à influência que o desenho institucional da cooperativa pode ter no comprometimento ou na fidelidade dos seus associados. Por meio das informações disponíveis no banco de dados do PDICOOPs – que conta com dados em formato de painel para os anos de 1989, 1992 e 2000 -, esta dissertação avalia empiricamente os determinantes do comprometimento dos associados com a cooperativa, tendo como foco os efeitos dos custos e benefícios da ação coletiva, propósito da organização cooperativa. Adicionalmente, esta dissertação investiga se o nível de comprometimento dos associados tem efeitos sobre o desempenho da cooperativa.

Future cenario planning in Brazilian logistics and transportation sector

Nas últimas décadas o setor de logística passou por grandes transformações pelo mundo. Assim, a eficiência do sistema logístico é importante para o crescimento econômico, a diversificação, redução dos custos operacionais e da pobreza. Segundo o Banco Mundial, o Brasil tornou-se uma das maiores economias do mundo, mas os custos logísticos elevados colocam em risco esse crescimento. Estes custos são em grande parte o resultado de diferenças em infraestrutura de cada região, juntamente com os encargos do setor rodoviário, que corresponde por 60% do total do transporte de carga do país. Entretanto, a logística brasileira está às portas de uma nova revolução, em práticas de negócios e eficiência, e também na qualidade e disponibilidade da infraestrutura de transportes e comunicações, e novos projetos e práticas para superar a situação. O objetivo deste estudo não é analisar o presente e as atuais tendências de logística do Brasil e do setor de transporte, mas sim modelar possíveis cenários futuros para os próximos anos. Em outras palavras, este trabalho mostra diferentes possibilidades de como o setor de logística e transporte poderá ser no futuro. Para isso, este trabalho irá utilizar a metodologia de cenários prospectivos e entrevistas com especialistas relacionados da área.

How to indirectly assess transaction costs to evaluate market integration: evidence from the international ethanol market

Mercados são instituições criadas para facilitar uma atividade de comercialização. Isto é possível porque um mercado é constituído por instituições que foram desenhadas para reduzir os custos de transação associados a este processo de troca. A partir dessas duas ideias, esta tese possui três objetivos principais. (i) Analisar por que a literatura de análise de cointegração tem mensurado estes custos de forma imprecisa. A principal razão é certa confusão entre os conceitos de custos de transação, de transporte e de comercialização. (ii) Propor um procedimento para mensurar indiretamente os custos de transação de mercado variáveis combinando os modelos de cointegração com mudança de regime e a estrutura teórica oferecidas pela Nova Economia Institucional. Este procedimento é aplicado para quantificar quanto custa comercializar etanol no mercado internacional usando suas atuais instituições. (iii) Por fim, usando os mesmos modelos e a mesma estrutura teórica, esta dissertação contesta a hipótese de que já existe um mercado internacional de etanol bem desenvolvido, tal qual a literatura tem assumido. De forma semelhante, também é avaliada a hipótese de que a remoção das barreiras comerciais norte-americanas para o etanol brasileiro seria uma condição suficiente para o desenvolvimento deste mercado internacional. Os testes aplicados rejeitam ambas as hipóteses.

Uma análise econômica das mudanças regulatórias no setor de petróleo no Brasil

Esta dissertação analisa o marco regulatório brasileiro do petróleo e gás sob a ótica da Teoria Econômica e faz uma comparação entre o regime de concessão, instituído pela Lei 9.478/97, e o de partilha de produção, adotado após a descoberta do Présal através da Lei 12.351/10. As características do modelo de concessão brasileiro são revistas assim como os resultados obtidos no setor de Exploração e Produção ao longo dos últimos quinze anos. O estudo faz uma abordagem sucinta sobre a descoberta do Pré-sal que ocasionou a alteração do marco regulatório pelo governo brasileiro. Os problemas relacionados à incerteza, poder de incentivo dos contratos, assim como as falhas de mercado relacionadas à assimetria de informação, externalidade e especificidade dos ativos são analisados para ambos os regimes. Ao longo do estudo também são abordadas questões de ordem prática como a insegurança jurídica, o papel da agência reguladora e a mudança do perfil das empresas interessadas em investir no país.

Labor legislation and the size of informal sector in Brazil

This paper studies the increase in the rate of informal workers in the Brazilian economy that occurred between 1985 and 1999. We develop an overlapping generations model with incomplete markets in which agents are ex-post heterogeneous. We calibrate it to match some features of the Brazilian economy for 1985. We conduct a policy experiment which reproduces the 1988 constitution reforms that increased the retirement benefits and labor costs in the formal sector. We show that these reforms can explain the increase in informal labor. Then, we conduct a policy experiment and analyze its impact on the Brazilian economy.

Banks, liquidity crises and economic growth

How do the liquidity functions of banks affect investment and growth at different stages of economic development? How do financial fragility and the costs of banking crises evolve with the level of wealth of countries? We analyze these issues using an overlapping generations growth model where agents, who experience idiosyncratic liquidity shocks, can invest in a liquid storage technology or in a partially illiquid Cobb Douglas technology. By pooling liquidity risk, banks play a growth enhancing role in reducing inefficient liquidation of long term projects, but they may face liquidity crises associated with severe output losses. We show that middle income economies may find optimal to be exposed to liquidity crises, while poor and rich economies have more incentives to develop a fully covered banking system. Therefore, middle income economies could experience banking crises in the process of their development and, as they get richer, they eventually converge to a financially safe long run steady state. Finally, the model replicates the empirical fact of higher costs of banking crises for middle income economies.

Demand expectations and the timing of stimulus policies

This paper proposes a simple macroeconomic model with staggered investment decisions. The model captures the dynamic coordination problem arising from demand externalities and fixed costs of investment. In times of low economic activity, a firm faces low demand and hence has less incentives for investing, which reinforces firms’ expectations of low demand. In the unique equilibrium of the model, demand expectations are pinned down by fundamentals and history. Owing to the beliefs that arise in equilibrium, there is no special reason for stimulus at times of low economic activity.

Main problems with the taxation of civil society organizations in Brazil: certifications and impact on payroll

The objective of this paper is to identify and analyze the main problems in the taxation—regarding both taxes themselves and compliance costs of taxation—of civil society organizations in Brazil. This study is qualitative descriptive research. A multiple case study with 26 organizations was performed. The results show that the problems mainly affect organizations with lower revenue and that do not work in the areas of education, health or social care. The main problems involve the taxation of the payroll and the difficulties related to obtaining and maintaining certifications. The study concludes with suggestions for the improvement of the regulatory framework.

Large scale laboratory cultures of Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance and economic indicators of a large scale fish farming in Mato Grosso, Brazil

Performance and economic indicators of a large scale fish farm that produces round fish, located in Mato Grosso State, Brazil, were evaluated. The 130.8 ha-water surface area was distributed in 30 ponds. Average total production costs and the following economic indicators were calculated: gross income (GI), gross margin (GM), gross margin index (GMI), profitability index (PI) and profit (P) for the farm as a whole and for ten ponds individually. Production performance indicators were also obtained, such as: production cycle (PC), apparent feed conversion (FC), average biomass storage (ABS), survival index (SI) and final average weight (FAW). The average costs to produce an average 2.971 kg.ha-1 per year were: R$ 2.43, R$ 0.72 and R$ 3.15 as average variable, fixed and total costs, respectively. Gross margin and profit per year per hectare of water surface were R$ 2,316.91 and R$ 180.98, respectively. The individual evaluation of the ponds showed that the best pond performance was obtained for PI 38%, FC 1.7, ABS 0.980 kg.m-2, TS 56%, FAW 1.873 kg with PC of 12.3 months. The worst PI was obtained for the pond that displayed losses of 138%, FC 2.6, ABS 0.110 kg.m-2, SI 16% and FAW 1.811 kg. However, large scale production of round-fish in farms is economically feasible. The studied farm displays favorable conditions to improve performance and economic indicators, but it is necessary to reproduce the breeding techniques and performance indicators achieved in few ponds to the entire farm.

Comparative analysis between a CAD model design and physical models obtained by manufacturing additive technologies using optical scan

This article presents a detailed study of the application of different additive manufacturing technologies (sintering process, three-dimensional printing, extrusion and stereolithographic process), in the design process of a complex geometry model and its moving parts. The fabrication sequence was evaluated in terms of pre-processing conditions (model generation and model STL SLI), generation strategy and physical model post-processing operations. Dimensional verification of the obtained models was undertook by projecting structured light (optical scan), a relatively new technology of main importance for metrology and reverse engineering. Studies were done in certain manufacturing time and production costs, which allowed the definition of an more comprehensive evaluation matrix of additive technologies.

APPLICATION of THE HAZARD ANALYSIS and CRITICAL CONTROL POINT (HACCP) SYSTEM on THE MUSHROOM PROCESSING LINE FOR FRESH CONSUMPTION

The Hazard Analysis and Critical Control Point (HACCP) is a preventive system that intends to guarantee the safety and harmlessness of food. It improves the quality of products as it eliminates possible defects during the process, and saves costs by practically eliminating final product inspection. This work describes the typical hazards encountered on the mushroom processing line for fresh consumption. Throughout the process, only the reception stage of mushrooms has been considered a critical control point (CCP). The main hazards at this stage were: the presence of unauthorised phytosanitary products; larger doses of such products than those permitted; the presence of pathogenic bacteria or thermo-stable enterotoxins. Putting into practice such knowledge would provide any industry that processes mushrooms for fresh consumption with a self-control HACCP-based system for its own productions.