Performance Evaluation of a Medium-temperature Solar Cooling Plant

AbstractSolar cooling plants represent today an interesting solution for air conditioning and primary energy savings. However, the plant configurations are still on development and the different solutions are tested in pilot plants. In this paper, a study on a possible high-efficiency configuration has been conducted. This solar cooling plant is based on a linear parabolic collectors solar field operating at 160- 180°C and coupled with a double effect absorption chiller. This solution could lead to an energy performance near to the DEC technology but with lower investment costs. A numerical model in TRNSYS has been developed in order to evaluate the performance and the possibility to build a pilot plant in the RSE experimental area. Thanks to the model, the system design process was studied and were identified the most important parameters (area of the solar field, nominal power of the absorption chillers, and volumes of the heat storage). The way how these parameters affect the overall performance of the plant has been investigated and a sizing procedure for solar cooling plant with a nominal refrigeration power of 20 – 45kW was developed. A building in the RSE area was chosen and the procedure has been applied in order to design a dedicated solar cooling plant

Kinetic and chemorheological modeling of thermosetting polyurethanes obtained from an epoxidized soybean oil polyol crosslinked with glycerin

Thermosetting polyurethanes were obtained using an aromatic isocyanate and a hydrophobic polyol formulation obtained from epoxidized soybean oil (ESO) crosslinked with glycerin. A systematic DSC analysis of the effect of catalyst type, crosslinker concentration, isocyanate index and ESO crystallization on the cure kinetics was conducted. The combination of a stannic catalyst at 0.2 wt.\% and glycerin at 20 wt.\% produced a cure kinetics governed by autocatalytic heat flow where vitrification played a key role in the formation of chemical bonds. The evolution of Tg as a function of conversion, which followed Di-Benedetto{\'}s predictions, supported the hypothesis that vitrification was a preponderant phenomenon during cure. The ESO crystallization had a melting endotherm centered at 35{\deg}C, affecting substantially the availability of reactive hydroxide groups. Dynamic Mechanical Analysis (DMA) of a post-cured sample revealed a Tg centered at 220{\deg}C, whereas quasi-static flexural mechanical tests revealed a flexural modulus of 2.14 GPa and a flexural strength of 99.4 MPa. Rheological experiments using a rheometer at isothermal conditions supported the hypothesis that vitrification played a key role in the evolution of apparent viscosity. A master model using Kim-Macosko equations was obtained for the proposed formulation

Plasma metalloproteinase activity is enhanced in the euglobulin fraction of breast and lung cancer patients

Matrix metalloproteinases (MMP) have been implicated in tumor invasion and metastasis. We verified, by gelatin zymography, MMP activity in the euglobulin plasma fraction of 82 healthy controls, 66 patients with benign diseases and 149 patients with breast, lung, colon or brain cancer. The euglobulin fractions assayed showed 4 gelatinolytic bands of 62, 92, 120 and 200 kDa. The median (Md) value for 92 kDa-MMP activity was significantly increased in breast (Md 1.34 arbitrary units [AU]/ml plasma, range 0.0–7.2) and lung cancer patients (Md 1.43 AU/ml, range 0.0–3.6) compared with the controls (Md 0.48 AU/ml, range 0.0–1.8). Patients with colon cancer or gliomas presented values of MMP-9 similar to those of the healthy population. Multivariate analysis indicated that plasma MMP-9 activity was not predicted by the known clinicopathological parameters such as age, stage, tumor size, number of positive lymph nodes, histologic grade, histologic type, nuclear grade or mitotic index. Lung cancer patients also presented high values of MMP-9 (Md 1.43, range 0.0–3.6 [n = 26]), without association with tumor stage or histologic type. The levels of 92 kDa-MMP activity in the plasma euglobulin fraction could be a potentially useful tumor marker in breast and lung cancer.Fil: Farias, Eduardo Francisco. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ranuncolo, Stella Maris. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cresta Morgado, Carlos. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Specterman, Sergio. Hospital Italiano; ArgentinaFil: Armanasco, Eduardo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología ; ArgentinaFil: Varela, Mirta. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lastiri, José. Hospital Italiano; ArgentinaFil: Pallotta, María Guadalupe. Hospital Italiano; ArgentinaFil: Bal, Elisa Dora. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Puricelli, Lydia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentin

Effetto di chitinasi e taumatina di vite sulla germinabilità di spore fungine

Following the attack of pathogens plants activate various defense mechanisms. Among these is known the accumulation of pathogenesis proteins(PR-proteins). The most expressed in Vitis are the chitinases, with 13 isoforms and responsible for the degradation of the fungal cell wall, and the "thaumatin-like-proteins", proteins that alter the functionality of the cell membrane and of which five types are known. The accumulation of these proteins is increasing during maturation. Guignardia Bidwell, agent of black rot is a major of fungal pathogens of the grapevine, which can affect the leaves, young shoots and above all the clusters in the early stages

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