Comparison between Measured and Model ( LBLand BRE) Predicted Infiltration Rates for a Passive Solar Test Cell

The pressurization technique is applied to the test cell at the JRC, Ispra, and important parameters for the LBL and BRE air infiltration models are calculated. The predictions of these models are compared with the tracer gas (SF₆) measurements. The differences between measured and predicted values of the air infiltration rates axe quite large. When the model parameters calculated from the tracer gas measurements are used, both models predict infiltration rates in good agreement with the field measurements. This means the physical models are acceptable but there is a need to refine the procedure for determination of model parameters.     

GLYCOLYTIC POTENTIAL IN SEMIMEMBRANOSUS MUSCLE OF ITALIAN LARGE WHITE PIGS

The objective of this study was to determine the distribution of glycolytic potential (GP) and its relationships with meat pH and the estimated breeding values (EBVs) of some traits in Italian Large White pigs. GP was determined on samples taken from the semimembranosus muscle at 120 min postmortem. Values of GP were normally distributed around a mean value of µmol/g 103.5  ±  23.0. Increasing GP was associated with decreasing pH at 2 and 24 h postmortem. A nonlinear relationship was found between GP and pH_u. GP also showed no relationship with the EBVs of daily gain and feed : gain ratio and a weak relationship with EBVs of carcass traits such as backfat thickness and lean cut weight. The positive but weak correlation between GP and EBV of ham weight loss during the first salting period may suggest a potential risk of using meat with high GP in dry-cured ham production.

PRACTICAL APPLICATIONS

Glycolytic potential is considered to be a determinant parameter for pork quality, especially when the meat is going to be processed. A better knowledge of its variation and its relationship with other valuable traits in vivo and postmortem is important in a breed such as the Italian Large White, largely used in the production of heavy pigs destined to produce meat for seasoned products. Data reported here on the variation of GP could suggest to breeder association the need to control this parameter in selection programs irrespectively to the presence of the RN^- negative allele, as the relationship of GP with processing losses could hinder dry-cured ham producers.     

Ownership Structures in Network Industries when the Rationality of Regulators is Bounded

This paper analyses the implication for allocative efficiencyof diffrent ownership structures of vertically related industriesin a simple game-theoretic setting. The upstream sector is monoplizedand regulated, while the downstream sector is imperfectly competitive.Regulation is imperfect in that the regulatory authority suffersfrom bounded rationality, and is not able to enforce optimalregulation. We consider both bomogenous and differentiated compositegoods. It generally turns out that when the regulator's enforcementcapabilities are limited, preventing the upstream monoplistfrom entering the downstream industry is socially undesirableunless the independent downstream rival enjoys a substantialproduction cost advantage. This holds true in spiteof the downstreamindustry is socially undesirable, unless the independent downstreamrival enjoys a substantial production cost advantage. This holdstrue in spite of the incentiveof the vertically integrated monopolistto manipulate accounts in order to raise the costs of the downstreamrival. Such reasoning especially applies when composite goodsare close substitures for one another.     

Factors influencing the service-like thermomechanical fatigue test cycle endurance of 1% CrMoV rotor steel

Service‐like thermomechanical fatigue tests have been performed in order to characterize the endurance of 1% CrMoV rotor steel under such transient thermal conditions. The key features of these tests are low strain rates (≤10^?5 s^?1) and longer hold periods. In all testpieces, ratcheting with progressive section reduction is observed in the central portion of the gauge length accompanied by local amplification of the strain range. The finite‐element‐based analysis of this phenomenon allows the measured endurances to be rationalized with those determined from isothermal tests. Post‐test inspection has revealed the development of two concurrent damaging mechanisms in the testpieces: (i) fatigue at the surface and (ii) creep in the interior. Different methods of damage calculation for creep–fatigue interaction are applied and compared in their predictive capabilities.     

SCHEDULING OF CONTINUOUS PARALLEL LINES IN THE EVAPORATION SECTION OF SUGAR PLANTS

Cost reduction in sugar industries can be achieved just by adjusting and optimizing structures and/or key process variables to assure maximum use of the sugar formed in the field. The evaporation section is the critical stage for efficient management of water and energy resources. Thus, the selected case study addresses the optimization of the operation of continuous evaporation units working in parallel and presenting a decrease of in efficiency with time. The problem was solved through mathematical programming that obtained optimum values for the operating variables. Therefore, it was necessary to mathematically formulate the optimization problem and to model the operations under study. A mixed integer nonlinear programming model (MINLP) was used in order to meet the targets. Also, a technical objective function with economical background was developed. The industrial implementation required as well the conception and development of a user-friendly decision-making tool to facilitate the routine work and to allow plant managers to check, accept, and put into practice the solution proposed. The application of the presented strategies to an industrial case study demonstrates the efficiency and potential of the approach adopted.     

Computer-based Automation and the Governance of Vertical Transactions

The purpose of this paper is to analyse the impact of computer-basedproduction technologies on firms' choice of governance modefor vertical transactions. We argue that in the long run diffusionof the new technologies should lead to a wider use of arm'slength relationships with suppliers of increasingly standardizedintermediate goods. In the early stage of diffusion, however,vertical transactions should tend to be internalized under bierarcbicalcontrol. In any case, network configurations based on subcontractingare negatively affected. Evidence supporting these argumentsis provided through a ‘laboratory’ study of make-or-buydecisions made by 100 adopter firms in the Italian metalworkingindustry.