Rheological study into the ageing process of high methoxyl pectin/sucrose aqueous gels

The ageing process of high methoxyl pectin (HMP)/sucrose gels was followed at different ageing temperatures by small amplitude oscillatory experiments. Dynamic mechanical measurements allowed the characterisation of the point at which the system undergoes the sol/gel transition. The HMP/sucrose system is extremely sensitive to temperature variation during ageing, especially in the lower temperature range. The viscoelastic behaviour through the gel point changes with the ageing temperature, probably due to variations in mobility of the pectin chains, and consequently, in the lifetime of junction zones. Weaker pectin networks are formed under thermal conditions unfavourable to the development of hydrophobic interactions. Gel time and elastic modulus have a complex dependence on temperature, which could be attributed to the different thermal behaviour of the intermolecular interactions that stabilise the nonpermanent cross links of these physical networks

Modelling uncertainty in decision making : fuzzy performance measures and fuzzy target

Decision making processes are based on performance measures that are compared with other performance measures values or with targets. Generally, the performance measure is only a number which do not consider the uncertainty associated with obtaining it such as measurement errors, precision and accuracy of measurement tools and subjective judgment. In this work, the uncertainty associated with performance measures is quantified through fuzzy numbers. The decision criterion is also represented by a fuzzy number. An indicator that considers both uncertainties in performance measure and decision criterion is developed. This indicator will help the decision maker once it quantifies the risk associated with the decision.Centro Algoritm

Quantification of uncertainty of performance measures using graph theory

In this paper, the graph theory is used to quantify the uncertainty generated in performance measures during the process of performance measurement. A graph is developed considering all the sources of uncertainty present in this process and their relationship. The permanent function of the matrix associated with the graph is used as the basis for determining an uncertainty index.This work was financed with FEDER Funds by Programa Operacional Fatores de Competitividade – COMPETE and by National Funds by FCT –Fundação para a Ciência e Tecnologia, Project: FCOMP-01-0124-FEDER-022674

On the characterisation of uncertainty in performance measurement systems

Performance measurement systems (PMSs) are receiving increasing attention from academics and practitioners particularly after the development of the Balanced Scorecard (BSC), and many PMSs are available nowadays. The hypothesis is that organisations need to reflect the uncertainty of its systems and contextual factors in their PMs to improve their models. This identification of uncertainty in PMS is the first step to reduce such uncertainty. This work provides a classification of uncertainty components that affect the quality of PMs

Data quality assessment in performance measurement

Data quality is a multi-dimensional concept and this research will explore its impact in performance measurement systems. Despite the large numbers of publications on the design of performance measurement systems (PMSs) and the definition of critical success factors to develop Performance Measures (PMs), from the data user perspective there are possibilities of finding data quality problems, that may have a negative impact in decision making. This work identifies and classifies uncertainty components of PMSs, and proposes a qualitative method for PMs’ quality assessment. Fuzzy numbers are used to represent PMs’ uncertainty and a method is proposed to calculate an indicator of the compliance between a PM and a target value that can serve as a risk indicator for the decision-maker.FEDER - Programa Operacional Fatores de Competitividade (COMPETE)Fundação para a Ciência e Tecnologia (FCT) - FCOMP-01-0124-FEDE

Efeito do ethephon na maturação pós-colheita de peras cultivar Princesinha.

Este trabalho objetivou avaliar o efeito de diferentes concentrações de ethephon em conjunto com diferentes tempos de armazenamento em temperatura controlada, na aceleração da 29 maturação de peras da cultivar princesinha

Diagnosis of quality problems in a small business

This article presents the results of a study conducted in a small textile company. The study aimed to characterize the state of quality management in the company highlighting weaknesses and areas for improvement. The methodology employed makes use of a set of tools for data collection and analysis such as interviews, flowcharts, diagrams of process analysis, defects registry matrix, Failure Modes and Effects Analysis (FMEA) and cause-effect matrix. Based on the gathered data, the company procedures in quality management and the production process performance are described and analyzed. Besides reflecting the quality state in the organization, the study also allowed to prioritize the elimination of causes that are responsible for poor performance.Fundação para a Ciência e a Tecnologia (FCT

Approach for preventive maintenance planning of machine tools

This paper addresses a common problem to manufacturing companies: the maintenance of machine tools and their components. Preventive maintenance has always been a great challenge for companies, due to the need of predicting failures or production shutdowns, which requires knowledge and resources. However, the planning of machine tools maintenance presents itself as an even more complex problem due to the distinct lifetimes of their components. Age-based preventive replacement and Block replacement models define optimal replacement intervals for one item based on associated maintenance costs. A machine tool can be seen as a serial system of components or items. The concepts of group technology and clustering can be used to group components together in order to define common preventive maintenance intervals and reduce the number of production stops. In the literature, some contributions are found. However, the defined groups are static as well as the preventive maintenance intervals. This paper presents a conceptual model for the definition of dynamic clusters and intervals. It also presents an application to record the inputs, data collected in real time, needed to group components and set up preventive maintenance intervals. The developed application is being implemented in a metalworking company.We would like to thank the companies that are involved in the project and express our appreciation for the commitment of the employees involved. This work has been supported by Norte 010247 FEDER 017833 – TechParts I&D