THE STICKY ISSUES OF DRYING

Unconrolled agglomeration of particles and adhesion of the particulate mass to wall surfaces are common severe problems in many drying operations. This paper reviews the mechanisms of interparticle and particle-surface attraction as well as the theory and the existing tests for characterising powders in terms of internal strength, wall friction and adhesion. The usefulness of the information obtained from these tests in dryer design and operation is critically reviewed. The importance of powder stickiness in various types of dryers is discussed and established methods of combating the problem are presented Recommendations an made for further research in the area of powder cohesion and adhesion.     

Resilience-aware design of interconnected supply chain networks with application to water-energy nexus

The effects of natural disasters, pandemic-induced lockdowns, and other disruptions often cascade across networks. In this work, we use minimum cost of resilience (MCOR) and operation-based resilience metrics to quantify network performance against single-connectivity failures and identify critical connections in interconnected networks. MCOR corresponds to the minimum additional infrastructure investment that is required to achieve a certain level of resilience. To guarantee MCOR, we incorporate the metrics in a multi-scenario mixed-integer linear program (MILP) that accounts for resilience in the design phase of interconnected networks. The goal is to obtain optimal generation and transportation capacities with flexible operation under all single-connectivity disruption scenarios. We demonstrate the applicability of our resilience-aware framework on a water-energy nexus (WEN) example focusing on grass-root design and retrofitting. We further apply the framework to analyze a regional WEN and observe that it is possible to achieve “full” resilience in the expense of additional regional investments.     

Exploiting Varying Resource Requirements in Wavelet-based Applications in Dynamic Execution Environments

In the context of future dynamic applications, systems will exhibit unpredictably varying platform resource requirements. To deal with this, they will not only need to be programmable in terms of instruction set processors, but also at least partial reconfigurability will be required. In this context, it is important for applications to optimally exploit the memory hierarchy under varying memory availability. This article presents a mapping strategy for wavelet-based applications: depending on the encountered conditions, it switches to different memory optimized instantations or localizations, permitting up to 51% energy gains in memory accesses. Systematic and parameterized mapping guidelines indicate which localization should be selected when, for varying algorithmic wavelet parameters. The results have been formalized and generalized to be applicable to more general wavelet-based applications.     

A Bayesian nonparametric study of a dynamic nonlinear model

A Bayesian nonparametric approach to modeling a nonlinear dynamic model is presented. New techniques for sampling infinite mixture models are used. The inference procedure specifically in the case of the logistic model and when the nonparametric component is applied to the additive errors is demonstrated.     

Effect of Lactobacillus cultures on microbiological,chemical and odour changes during storage of rainbow trout fillets

The purpose of this study was to investigate the effect of applying two Lactobacillus protective cultures on microbiological, chemical and odour changes during storage of refrigerated vacuum‐packed rainbow trout (Oncorrynchus mykiss) fillets. Lactobacillus sakei CECT 4808 and Lb. curvatus CECT 904^T were inoculated individually or in combination into rainbow trout fillets. The samples were vacuum‐packed and stored at 4 ± 0.5 °C and were assessed during a 20‐day storage period for microbiological (Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria (LAB), H₂S‐producing bacteria, yeasts and moulds) and chemical (pH, total volatile basic nitrogen, lipid oxidation) parameters and off‐odour. Samples inoculated with Lb. sakei and with both strains had significantly (P≤0.05) lower counts of all microbiological spoilage indicator organisms (Enterobacteriaceae, Pseudomonas spp., H₂S‐producing bacteria, yeasts and moulds) than those inoculated with Lb. curvatus or the controls. All chemical parameters examined and off‐odour scores were also significantly (P≤0.05) improved in the samples inoculated with Lb. sakei or with both strains compared with those inoculated with Lb. curvatus or the controls. Lb. sakei generally showed a better preservative effect (P≤0.05) than the combination of strains. Inoculation with Lb. sakei CECT 4808 could provide an additional hurdle to improve shelf‐life of refrigerated vacuum‐packaged trout fillets, as inoculation with this strain resulted in extension of shelf‐life by 5 days. Furthermore, this strain showed some antioxidative ability, which could retard lipid oxidation in fish. Copyright © 2006 Society of Chemical Industry     

Spray Drying of Raisin Juice Concentrate

Raisin juice concentrate is a natural sweetener in syrup or paste form and it is produced from second-grade dry raisins by leaching them with water. Dried raisin juice, although is easier to handle and has more potential applications than the syrup, is not available in the market. In the present study, raisin juice powder was produced with a lab-scale spray dryer. The problem of stickiness in the drying chamber was overcome through the use of 21 DE, 12 DE, and 6 DE maltodextrins as drying aid agents. For each type of maltodextrin, the dryer operating conditions and the minimum concentration of maltodextrin in the feed, necessary for successful powder production, were determined. The maximum ratio of (raisin juice solids)/(maltodextrin solids) achieved was 67/33 and was made possible with the use of 6 DE maltodextrin. The inlet and outlet drying air temperatures were 110 and 77°C respectively, while the feed contained 40% w/w total solids. The physical and sensory properties of all powders produced were determined and found to be satisfactory, the only exception being their high hygroscopicity.     

Quecksilber in Fischen

European Food Research and Technology - Der Quecksilbergehalt von Fischen wurde bestimmt. Der Mittelwert von 1400 Bestimmungen zeigte, daß das Gesamtquecksilber der frischen Fischmuskulatur...     

Abhängigkeit der inneren Rückspannung von den Kriechbedingungen bei Reinkupfer und bei den Stählen X 6 CrNi 18 11 und X 8 CrNiMoNb 16 16

Am Beispiel der austenitischen Stähle X 8 CrNiMoNb 1616 und X 6 CrNi 1811 sowie des reinen Metalls SF-Cu, das aus Vergleichszwecken herangezogen wurde, ist die Abhängigkeit der quasi-stationären inneren Rückspannung bei Zeitstandbeanspruchung von den Kriechbedingungen untersucht worden. Die Messungen der inneren Rückspannungen erfolgten anhand von strain transient dip tests. Ermittelt wurden die Abhängigkeiten der quasi-stationären inneren Rückspannung im sekundären Kriech-bereich von der Lastspannung σ und der Temperatur T. Festgestellt wurde hierbei, daß mit zunehmender Lastspannung, bei konstanter Temperatur, die innere Rückspannung σ_i ebenfalls zunahm; das Verhältnis σ_i/σ nahm jedoch ab. Die Zunahme der Temperatur bei konstanter Spannung bewirkte hingegen eine deutliche Abnahme sowohl der inneren Rückspannung als auch des Verhältnisses σ_i/σ. Die stationäre Kriechgeschwindigkeit wurde als Funktion der effektiven Spannung σ_eff aufgefaßt. Bei allen Untersuchungswerkstoffen läßt sich diese Abhängigkeit durch eine Potenzfunktion der effektiven Spannung gut erfassen. Die effektiven Spannungsexponenten sind werkstoffabhängig. Als Näherung kann bei den technischen Werkstoffen der werkstoffunabhängige Exponent 4 herangezogen werden. Beim reinen Metall ist diese Näherung nicht zulässig. Ausgehend von der ermittelten Potenzfunktion wurde die Spannungsabhängigkeit der inneren Rückspannung formuliert. Hiermit wurden die experimentell ermittelten Zusammenhänge gut erfaßt.