System-on-package: a broad perspective from system design to technology development

In this paper, we summarize and analyze main challenges towards system-on-package (SoP) integration with a broad perspective from system design to technology development. We see that the future SoP faces a main challenge of changed system architecture that will be different from today’s personal computer or PC-based systems. It is likely that communication-network based system architectures will be interesting to future SoP platforms. Second, we find that a major paradigm shift will occur in design methodology for SoP integration that emphasizes a coherent co-design of chip, package and system in a mixed signal environment and in combination with new issues such as virtual components integration. On the technology side, the major challenges will be power dissipation and system cooling, low-cost and thermal-matched high-density interconnect substrates, as well as low-cost passive components integration. Finally, we present some research examples that aim to cope with these new challenges on a strategic basis.     

Perceptual use of nonaccidental properties.

Reviews the literature about the nonaccidental properties (NAPs) cotermination, straightness, and parallelism to trace their historical roots, to list the properties that function as NAPs, and to discuss the psychological evidence for their detection and use. Four experiments are reviewed, and four are fully described that were designed to test the perceptual use of skewed symmetry, which results from orthographic projection of planar bilateral or mirror symmetry. Despite the large symmetry advantage obtained in all experiments, skewed symmetry is only perceived as bilateral symmetry-in-depth in cases of closed polygons or dot patterns with higher-order types of symmetry. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Critical evaluation of approaches for on-line batch process monitoring

Since the introduction of batch process monitoring using component models in 1992, different approaches for statistical batch process monitoring have been suggested in the literature. This is the first evaluation of five proposed approaches so far. The differences and similarities between the approaches are highlighted. The derivation of control charts for these approaches are discussed. A control chart should give a fast and reliable detection of disturbances in the process. These features are evaluated for each approach by means of two performance indices. First, the action signal time for various disturbed batches is tested. Secondly, the probability of a false warning in a control chart is computed. In order to evaluate the five approaches, five different data sets are studied: one simulation of a batch process, three batch processes obtained from industry and one laboratory spectral data set. The obtained results for the performance indices are summarised and discussed. Recommendations helpful for practical use are given.     

Chemistry of metapleural gland secretions of three attine ants,Atta sexdens rubropilosa,Atta cephalotes,andAcromyrmex octospinosus (Hymenoptera: Formicidae)

The chemical composition of the secretions of the metapleural glands of workers and soldiers of twoAtta species,Atta sexdens rubropilosa andA. cephalotes, and workers ofAcromyrmex octospinosus, has been studied. As indicated by infrared spectrometry and confirmed by the ninhydrin test, the secretions contain chiefly proteins. Of the volatile acidic portion, which is present as ionized salts, phenylacetic acid is the major component in workers and soldiers ofA. s. rubropilosa andA. cephalotes. BothAtta species also contain 3-hydroxydecanoic acid and its homolog as minor components together with indoleacetic acid. While there are qualitative similarities in the acidic composition in the secretions ofA. s. rubropilosa andA. cephalotes, they differ quantitatively. The secretion ofAcromyrmex octospinosus contains 3-hydroxydecanoic and indoleacetic acids, but lacks phenylacetic acid. The bactericidal and fungicidal actions of the three major substances have been confirmed.     

Influence of elastic and plastic anisotropy on the flow behavior in a duplex stainless steel

The load partitioning between two phases in a cold-rolled duplex stainless steel has been experimentally studied in situ by X-ray diffraction, for different loading directions. It was found that the load partitioning between the two phases is dependent on the loading direction. For loading in the rolling direction, both phases deform plastically to the same degree, while more plastic deformation occurs in the austenitic phase during loading in the transverse direction. For loading in the 45-deg direction, more plastic deformation occurs in the ferritic phase. The strong crystallographic texture in the ferritic phase makes the material anisotropic, with a higher stiffness and yield strength in the transverse direction compared to the rolling direction. The measured texture was used as input to theoretical predictions of both elastic and plastic anisotropy. The plastic anisotropy was predicted by assuming intragranular slip as the main deformation mechanism. The predicted anisotropic material properties were then used in finite-element simulations to study the flow behavior of the material in different directions. The predicted flow behavior was found to be in good agreement with the experimentally observed load partitioning between the phases for loading in the rolling and transverse directions. However, the yield strength of the ferritic phase during loading in the 45-deg direction was found to be lower than what was predicted. The reason for this is the difference in slip characteristics in different sample directions, because of the morphological texture.     

Unit cell structure of crystal polytypes in InAs and InSb nanowires

The atomic distances in hexagonal polytypes of III-V compound semiconductors differ from the values expected from simply a change of the stacking sequence of (111) lattice planes. While these changes were difficult to quantify so far, we accurately determine the lattice parameters of zinc blende, wurtzite, and 4H polytypes for InAs and InSb nanowires, using X-ray diffraction and transmission electron microscopy. The results are compared to density functional theory calculations. Experiment and theory show that the occurrence of hexagonal bilayers tends to stretch the distances of atomic layers parallel to the c axis and to reduce the in-plane distances compared to those in zinc blende. The change of the lattice parameters scales linearly with the hexagonality of the polytype, defined as the fraction of bilayers with hexagonal character within one unit cell.     

Joule Heating Induced Nonlinear Behavior in?the?Phase-Separated System (La0.73Bi0.27)0.67Ca0.33MnO3

A conduction mechanism has been investigated in the phase-separated compound (La_0.73Bi_0.27)_0.67Ca_0.33MnO₃ at various temperatures below and above the ferromagnetic-paramagnetic (FM-PM) transition temperature T _c . When a high current density applied, a strong nonlinear behavior with negative differential resistance (NDR) was observed. The application of an external magnetic field inhibits the appearance of NDR. Usually, the experiments strongly suggest that the electric field has an important effect on the nonlinear conduction behavior of the sample. However, our experiment shows that, instead of the electric field effect (that is electroresistance), the observed nonlinear behavior results mainly from the Joule heating effect. Thus, we should exercise extreme caution when interpreting the nonlinear conduction behavior of the phase-separated system.     

Use of endospore-forming bacteria as an active oxygen scavenger in plastic packaging materials

The incorporation of active oxygen scavengers in polymer packaging materials is essential to allow packaging of oxidation sensitive products. Opposed to the currently available chemical oxygen scavengers, systems based upon natural and biological components could have advantages towards consumer perception and sustainability. A modelsystem for a new oxygen scavenging poly(ethylene terephthalate) (PET) bottle is proposed using an endospore-forming bacteria genus Bacillus amyloliquefaciens as the active ingredient. Spores were incorporated in poly(ethylene terephthalate, 1,4-cyclohexane dimethanol) (PETG), an amorphous PET copolymer having a considerable lower processing temperature and higher moisture absorption compared to PET. To asses spore viability after incorporation, a method was optimized to extract spores from PETG using a chloroform/water mixture. Samples were also analyzed using a Live/Dead BacLight Bacterial Viability kit. It was shown that endospores were able to survive incorporation in PETG at 210 °C. Incorporated spores could actively consume oxygen for minimum 15 days, after an activation period of 1–2 days at 30 °C under high humidity conditions.

Industrial relevance

The study describes a modelsystem for the use of incorporated spores genus Bacillus amyloliquefaciens as an active oxygen scavenger in PET multilayer bottles using PETG as the middle layer material. Industrially, oxygen scavengers using incorporated viable spores as the active compound could have advantages towards consumer perception, recyclability, safety, material compatibility, production costs, … compared to currently available chemical oxygen scavengers.