Compressive Stress-Strain Relationships of Two Puffed Cereals in Bulk

The compressive stress-strain relationships of two puffed cereals, rice and corn based, in bulk were determined using a Universal Testing Machine. The general sigmoid shape of the relationship could be described by a four parameter empirical model originally developed for cellular solids. Jaggedness could be expressed in terms of an apparent fractal dimension and/or the mean magnitude of the power spectrum determined using the Fast Fourier Transform. Both measures as well as a particular parameter of the empirical model were sensitive indicators of the changes in the stress-strain relationships resulting from exposure to different relative humidities. Although the stress strain relationship, especially of dry samples, had an irregular, irreprodu-cible shape, the magnitude of the two roughness measures was highly reproducible.     

Advanced Capillary Structures for High Performance Heat Pipes

High performance heat pipes are widely used for the thermal control of electronic devices. Concerning heat transport limitations, typical wick or capillary structures show advantages in some aspects and disadvantages in others. An advanced capillary structure was developed with high thermal effectiveness, low axial pressure drop, high capillary pressure, and a high boiling limit. It combines open minichannels with open microchannels that are manufactured perpendicular on top of the minichannels. The heat transfer coefficient in the evaporator zone, which is a characteristic value for the thermal effectiveness, was up to 3.3 times higher compared to a similar structure without microchannels. A model that combines micro- and macroscopic phenomena was developed. It predicts the heat transfer coefficient with quite good accuracy as long as the microchannels are at least 300 μm.     

Fiscal-period-based service level constraints and safety stock requirements†

This paper deals with service level constraints which are defined over a fiscal period. Fiscal-period-based service level constraints are considerably more complex than their lead-time counterparts and result in significantly different safety stock requirements. Thus, a confusion between a lead-time and fiscal-period perspective can result in substantial financial consequences and is therefore of managerial relevance. Although no generalizations are possible from the limited results presented, further computational experience suggests that the findings reported hold over a wide range of situations.     

A RESEARCH NOTE COMPRESSIVE STRESS-STRAIN RELATIONSHIPS of AGGLOMERATED INSTANT COFFEE1

Shallow beds (3–9 mm) of two commercial agglomerated spray dried instant coffees were compressed using a Universal testing machine. the stress-stress relationships had the sigmoid shape characteristic of cellular solids and could be described by a four parameter model originally developed for solid foams. the magnitude of the model parameters was less sensitive to the relative humidity level at storage in the range of 11–65% than to the bed's thickness. the jaggedness of the stress-strain relationship is a manifestation of the particles brittleness and crumbliness and it is considerably reduced when they are plasticized, as a result of moisture uptake, for example. the degree of jaggedness, determined in the normalized (dimensionless) stress-strain relationships, could be qualified and compared in terms of an apparent (“natural”) fractal dimension. It was calculated from the linear region of the corresponding Richardson plots using the “blanket” algorithm. This apparent fractal dimension, however, was only a relative measure of jaggedness, since both the scales and resolution of the mechanical signatures were arbitrarily selected. the jaggedness of the individual agglomerates signatures could not be directly inferred from those of their assemblies, primarily because the effects of averaging and the bed's cushioning could not be separated.     

AAV-based gene therapy approaches for genetic forms of tauopathies and related neurogenetic disorders

Tauopathies comprise a spectrum of genetic and sporadic neurodegenerative diseases mainly characterized by the presence of hyperphosphorylated TAU protein aggregations in neurons or glia. Gene therapy, in particular adeno-associated virus (AAV)-based, is an effective medical approach for difficult-to-treat genetic diseases for which there are no convincing traditional therapies, such as tauopathies. Employing AAV-based gene therapy to treat, in particular, genetic tauopathies has many potential therapeutic benefits, but also drawbacks which need to be addressed in order to successfully and efficiently adapt this still unconventional therapy for the various types of tauopathies. In this Viewpoint, we briefly introduce some potentially treatable tauopathies, classify them according to their etiology, and discuss the potential advantages and possible problems of AAV-based gene therapy. Finally, we outline a future vision for the application of this promising therapeutic approach for genetic and sporadic tauopathies.     

Occurrence based service-level constraints during a fiscal period

An occurrence-based service-level constraint, defined over a fiscal period, is introduced. This service-level constraint measures the actual number of stockout episodes and restricts it to a managerially acceptable level. It is shown that the solution to the emerging chance-constrained inventory problem is independent of the type and parameters of the demand distribution. The approach is demonstrated and its managerial implications, in particular with respect to reorder points, are discussed.