Efficiency assessment for a small heliostat solar concentration plant

Summary In this paper, a small non-imaging focusing heliostat is presented, and an analytical model for assessing its performance is described. The main novelty of the system lies in the tracking mechanism and the mirror mount, which are based on off-the-shelf components and allow a good trade-off between accuracy and costs. The concentrator mirrors are moved by this two-axis tracking machinery to reflect the sun's rays onto a fixed target, the dimensions of which can be varied to suit the user's needs. A prototype plant to be located in central Italy was designed and simulated with a ray-tracing algorithm, and it comprises 90 heliostats for a total reflective area of 7.5 m2. The reflected solar rays are tracked taking the mechanical positioning errors of the tracking system into account. The total flux of radiation energy hitting the target was determined, and intensity distribution maps were drawn. Simulations showed that the system's optical efficiency can exceed 90% in summer, despite the tracking errors, mainly because of the smaller distance between the heliostats and the receiver. The solar concentration ratio over a receiver of 250 mm in diameter reached 80 suns with a very good uniformity. Over a 400-mm receiver, the concentrated radiation was less uniform, and the solar concentration ratio reached 50 suns, with a higher optical efficiency and collected solar radiation. The present concentration ratio is still suitable for many applications ranging from the electric power production, industrial process heat, and solar cooling. Copyright © 2014 John Wiley & Sons, Ltd

A EMPRESA PRIVADA COMO LOCAL SÓCIOOCUPACIONAL DO ASSISTENTE SOCIAL: REFLEXÕES ACERCA DA RESPONSABILIDADE SOCIAL

O presente artigo é resultado dos estudos realizados na disciplina de Oficina de Empresa no curso de Serviço Social das Faculdades Integradas “Antônio Eufrásio de Toledo” de Presidente Prudente – São Paulo. A presente pesquisa tem como objetivo realizar uma discussão sobre a atuação do assistente social na empresa privada capitalista, destacando a trajetória da profissão e sua atuação neste local sócioocupacional. E, ainda, realizar reflexões acerca da responsabilidade social neste local de atuação, fazendo um resgate histórico desta atividade dentro da empresa. Para concretizar este objetivo, utilizou-se pesquisa bibliográfica e eletrônica direcionadas ao tema. O método utilizado nesta pesquisa é o dialético, sendo assim, a teoria crítica

A EMPRESA PRIVADA COMO LOCAL SÓCIOOCUPACIONAL DO ASSISTENTE SOCIAL: REFLEXÕES ACERCA DA RESPONSABILIDADE SOCIAL

O presente artigo é resultado dos estudos realizados na disciplina de Oficina de Empresa no curso de Serviço Social das Faculdades Integradas “Antônio Eufrásio de Toledo” de Presidente Prudente – São Paulo. A presente pesquisa tem como objetivo realizar uma discussão sobre a atuação do assistente social na empresa privada capitalista, destacando a trajetória da profissão e sua atuação neste local sócioocupacional. E, ainda, realizar reflexões acerca da responsabilidade social neste local de atuação, fazendo um resgate histórico desta atividade dentro da empresa. Para concretizar este objetivo, utilizou-se pesquisa bibliográfica e eletrônica direcionadas ao tema. O método utilizado nesta pesquisa é o dialético, sendo assim, a teoria crítica

Numb Is an Endocytic Protein

Numb is a protein that in Drosophila determines cell fate as a result of its asymmetric partitioning at mitosis. The function of Numb has been linked to its ability to bind and to biologically antagonize Notch, a membrane receptor that also specifies cell fate. The biochemical mechanisms underlying the action of Numb, however, are still largely unknown. The wide pattern of expression of Numb suggests a general function in cellular homeostasis that could be additional to, or part of, its action in fate determination. Such a function could be endocytosis, as suggested by the interaction of Numb with Eps15, a component of the endocytic machinery. Here, we demonstrate that Numb is an endocytic protein. We found that Numb localizes to endocytic organelles and is cotrafficked with internalizing receptors. Moreover, it associates with the appendage domain of α adaptin, a subunit of AP2, a major component of clathrin-coated pits. Finally, fragments of Numb act as dominant negatives on both constitutive and ligand-regulated receptor-mediated internalization, suggesting a general role for Numb in the endocytic process

Loss of negative regulation by Numb over Notch is relevant to human breast carcinogenesis

The biological antagonism between Notch and Numb controls the proliferative/differentiative balance in development and homeostasis. Although altered Notch signaling has been linked to human diseases, including cancer, evidence for a substantial involvement of Notch in human tumors has remained elusive. Here, we show that Numb-mediated control on Notch signaling is lost in ∼50% of human mammary carcinomas, due to specific Numb ubiquitination and proteasomal degradation. Mechanistically, Numb operates as an oncosuppressor, as its ectopic expression in Numb-negative, but not in Numb-positive, tumor cells inhibits proliferation. Increased Notch signaling is observed in Numb-negative tumors, but reverts to basal levels after enforced expression of Numb. Conversely, Numb silencing increases Notch signaling in normal breast cells and in Numb-positive breast tumors. Finally, growth suppression of Numb-negative, but not Numb-positive, breast tumors can be achieved by pharmacological inhibition of Notch. Thus, the Numb/Notch biological antagonism is relevant to the homeostasis of the normal mammary parenchyma and its subversion contributes to human mammary carcinogenesis

Alterations in the α2 δ ligand, thrombospondin-1, in a rat model of spontaneous absence epilepsy and in patients with idiopathic/genetic generalized epilepsies

Objectives Thrombospondins, which are known to interact with the α2δ subunit of voltage-sensitive calcium channels to stimulate the formation of excitatory synapses, have recently been implicated in the process of epileptogenesis. No studies have been so far performed on thrombospondins in models of absence epilepsy. We examined whether expression of the gene encoding for thrombospondin-1 was altered in the brain of WAG/Rij rats, which model absence epilepsy in humans. In addition, we examined the frequency of genetic variants of THBS1 in a large cohort of children affected by idiopathic/genetic generalized epilepsies (IGE/GGEs). Methods We measured the transcripts of thrombospondin-1 and α2δ subunit, and protein levels of α2δ, Rab3A, and the vesicular glutamate transporter, VGLUT1, in the somatosensory cortex and ventrobasal thalamus of presymptomatic and symptomatic WAG/Rij rats and in two control strains by real-time polymerase chain reaction (PCR) and immunoblotting. We examined the genetic variants of THBS1 and CACNA2D1 in two independent cohorts of patients affected by IGE/GGE recruited through the Genetic Commission of the Italian League Against Epilepsy (LICE) and the EuroEPINOMICS-CoGIE Consortium. Results Thrombospondin-1 messenger RNA (mRNA) levels were largely reduced in the ventrobasal thalamus of both presymptomatic and symptomatic WAG/Rij rats, whereas levels in the somatosensory cortex were unchanged. VGLUT1 protein levels were also reduced in the ventrobasal thalamus of WAG/Rij rats. Genetic variants of THBS1 were significantly more frequent in patients affected by IGE/GGE than in nonepileptic controls, whereas the frequency of CACNA2D1 was unchanged. Significance These findings suggest that thrombospondin-1 may have a role in the pathogenesis of IGE/GGEs

Use of Stirling cryocoolers in small-scale LNG plants: opportunities and critical issues

Nowadays an increasing numbers of small-scale LNG projects are arising in the world beside very big plants in the Asia Pacific area. In Europe a new regulatory framework is preparing the ground for the design and construction of many distributed LNG plants, with an increasing interest on micro-scale plants with production below 40TPD. In a LNG storage tank, because of the inevitably heat incomes from the ambient part of boil-off gas is generated. Especially in small-scale plants and in storage facilities, boil-off phenomena are very important and several methods are currently adopted to minimize the boil-off and re-liquefy the vaporized natural gas. Among the different technologies to carry out this process, Stirling engines used as cryocoolers prove to have a very interesting potential because they are able to achieve temperatures well below the liquefaction of the natural gas thus assuring the continuous re-liquefaction of the boil-off or the subcooling of the natural gas. In this work, the authors first analyse the most critical aspects related to the thermodynamic and operation of the LNG plants and storage that give rise to the boiloff phenomena and then evaluate the potential for the adoption of Stirling cycle cryocoolers. In particular, two small-scale LNG storage tanks with capacity of 1’500 m3 and 10’000 m3 have been considered. Despite the BOG from loading and unloading of the tanks has not been taken into account, the analysis has proved that StirLNG-4 and StirLNG-16 cryocoolers respectively are able to manage the generated BOG. Hence, the analysis has shown that commercially available Stirling cycle cryocoolers could be used to re-liquify the BOG generated in small-scale LNG plants thus enlarging the potential market of these machines

A EMPRESA PRIVADA COMO LOCAL SÓCIOOCUPACIONAL DO ASSISTENTE SOCIAL: REFLEXÕES ACERCA DA RESPONSABILIDADE SOCIAL

This article is the result of studies conducted in the discipline of Workshop Company in the course of Social Service of Integrated Schools "Antônio Eufrásio de Toledo" Presidente Prudente - São Paulo. This research aims to conduct a discussion on the role of social worker in private capitalist enterprise, highlighting the history of the profession and its socio-occupational activity in this location. And also, to reflect on the social responsibility at the place of work, doing a historical restoration of this activity within the company. To achieve this goal, we used bibliographic and electronic research directed to the topic. The method used in this research is dialectical, thus being critical theory

Analysis of the expression and activity of nitric oxide synthase from marine photosynthetic microorganisms

Nitric oxide (NO) functions as a signaling molecule in many biological processes in species belonging to all kingdoms of life. In animal cells, NO is synthesized primarily by NO synthase (NOS), an enzyme that catalyze the NADPH-dependent oxidation of l -arginine to NO and l -citrulline. Three NOS isoforms have been identifi ed, the constitutive neuronal NOS (nNOS) and endothelial NOS (eNOS) and one inducible (iNOS). Plant NO synthesis is complex and is a matter of ongoing investigation and debate. Despite evidence of an Arg-dependent pathway for NO synthesis in plants, no plant NOS homologs to animal forms have been identifi ed to date. In plants, there is also evidence for a nitrate-dependent mechanism of NO synthesis, catalyzed by cytosolic nitrate reductase. The existence of a NOS enzyme in the plant kingdom, from the tiny single-celled green alga Ostreococcus tauri was reported in 2010. O. tauri shares a common ancestor with higher plants and is considered to be part of an early diverging class within the green plant lineage. In this chapter we describe detailed protocols to study the expression and characterization of the enzymatic activity of NOS from O. tauri. The most used methods for the characterization of a canonical NOS are the analysis of spectral properties of the oxyferrous complex in the heme domain, the oxyhemoglobin (oxyHb) and citrulline assays and the NADPH oxidation for in vitro analysis of its activity or the use of fl uorescent probes and Griess assay for in vivo NO determination. We further discuss the advantages and drawbacks of each method. Finally, we remark factors associated to the measurement of NOS activity in photosynthetic organisms that can generate misunderstandings in the interpretation of results.Fil: Foresi, Noelia Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Correa Aragunde, Maria Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Santolini, Jerome. Centre National de la Recherche Scientifique; Francia. iBiTec-S; FranciaFil: Lamattina, Lorenzo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentin