Institutions and Commitment

The thrust of this paper is that to understand the roles institutionsplay in society, a deep analysis of opportunism and its implicationsis necessary. For that purpose, a transactions costs-cum-positivepolitical theory approach is developed, with a focus on therole of institutions and their implications for regulatory commitment.A major issue is restraining political opportunism. Countriesthat have succeeded in developing a healthy private sector arethose that have developed institutions that restrain governmentaldecision-making. But such restraining is itself a politicalchoice. Countries with electoral and legislative systems thatbring about decentralized government have stronger chances ofdeveloping equilibria where government discretion is restrained.     

EFFECT OF INTERMITTENT WARMING AND MODIFIED ATMOSPHERE PACKAGING ON COLOR DEVELOPMENT OF PEACHES

Peaches (Prunus persica L. Batsch cv. ‘Paraguayo’) at firm-breaker stage of maturity were stored at 0.5 C for 3 weeks. Intermittent warming (IW) for 1 day at 20C every 6 days of cold storage at 0.5C, modified atmosphere packaging (MAP) generated by 42 μm oriented polypropylene bags, and a combination of MAP and IW were applied. Changes in skin and flesh color (measured by CIELAB parameters and Chroma and Hue angle color indices) during normal postharvest ripening at 20C, during cold storage and after 3 days of post-storage ripening were studied. For commercial purposes, IW led to the same color level being reached as was found in normal postharvest ripened fruits. In contrast, the high carbon dioxide and low oxygen generated by MAP alone or combined with IW delayed color development even during post-storage ripening. Ground color measured by hue angle was the best index for monitoring color evolution during ripening and storage.     

Evaluation of Gelation and Solubility of Bovine Plasma Protein Isolates

Gelation and solubility of bovine plasma protein isolates prepared from liquid plasma using different acids (HCl, H₃PO₄, H₂SO₄) and bases (NaOH, Na₂CO₃) were evaluated and compared to commercial plasma. Protein recovery was over 90%. Solubility at 1% (w/v) was low in pH range 4.0 to 5.5 but similar to commerical plasma in pp range 5.5 to 8.0 (p < 0.01). All isolates gelled at a concentration o 6.0%. Only isolate H₃PO₄-Na₂CO₃ and commercial plasma gelled at a minimum concentration of 4.0%. This concentration decreased to 2.4% for the same isolate when 0.025M Ca⁺⁺ ion was added.     

SOLAR CONTROL RESEARCH ACTIVITIES UNDERTAKEN IN THE FRAMEWORK OF PASCOOL

The Solar Control Subtask group activities were aimed at defining and validating an innovative combined procedure to model and experimentally characterize external shading devices. The objectives were pursued throughout joined activities on detailed and simplified modelling, pilot experiments and testing

The modelling was developed with some important innovative features, like three-dimensional characterization, actual representation of solar radiation and solar-optical properties, coupling of thermal performance Environment/Shading device/Glazing, actual film coefficients. It was based on the outcomes from specific experiments conducted in laboratory (solar-optical properties), in PASLINK test cells (film coefficients on glazing and shading device) and in a two-axis tracking bench equipped with a solar transmittance measurement apparatus properly developed. This outdoor testing allows to measure the average value of diffuse and angular direct solar transmittance of the non-homogeneous shading assembly with an accuracy better than ± 5%

Finally, on the basis of the above results an innovative procedure based on a combined modelling/testing activity for the full characterization of the devices (parameters of shortwave radiation, long-wave radiation and convective exchanges) was set up and validated. The validation was successfully performed on five widespread shading components (retractable Venetian blind with metallic tilting slats, shulter with wooden tilting slats, fixed slats system, sunbreaker with movable vertical fins, roller blind). Furthermore, a preliminary procedure for daylighting performance evaluation of the shading device was defined and tested.     

Dynamical variable structure systems approach to switched capacitor circuit models

A new model, of a dynamic nature, is proposed for the basic analysis of switched capacitor circuits. The model represents a significant conceptual departure from the traditional frequency-dependent equivalent resistor model. Using Filippov's concept of solution for systems governed by right-hand side discontinuous differential equations, such as those regulated by a pulse-width modulation control strategy, a general and more realistic dynamical model is proposed for switched capacitor circuits. The traditional model is easily rederived and reinterpreted as the outcome of a sequential singular perturbation procedure carried on an idealized version of the proposed dynamical model.     

PRESSURE DROP and FRICTION FACTOR IN HELICAL HEAT EXCHANGERS UNDER NONISOTHERMAL and TURBULENT FLOW CONDITIONS1

This study involved the determination of pressure drop and friction factor (f) in helical heat exchangers under turbulent flow conditions. the experiments were conducted in helical heat exchangers, with coils of two different curvatures ratios (d/D = 0.114 and 0.078) at various flow rates (9.46 × 10^?5 ‐ 6.31 × 10^?4 m³/s) and end‐point temperatures (20, 93.3, 121, 149C). the computed friction factor (f) in the helical heat exchanger was compared to published correlations, and it was found that the experimental data was in good agreement with them. In addition, correlations to determine pressure drop based on the Reynolds number, curvature ratio, and temperature were developed.