Integrated Temperature Sensors for On-Line Thermal Monitoring of Microelectronic Structures

Built-in temperature sensors increase the system reliability by predicting eventual faults caused by excessive chip temperatures. In this paper, simple and efficient built-in temperature sensors for the on-line thermal monitoring of microelectronics structures are introduced. The proposed temperature sensors produce a signal oscillating at a frequency proportional to the temperature of the microelectronics structure and therefore they are compatible to the oscillation-test method. The oscillation-test method is a low-cost and robust test method for mixed-signal integrated circuits based on transforming the circuit under test (CUT) to an oscillator. This paper presents the design and detailed characteristics of the sensors proposed based on the CMOS 1.2 µm technology parameters of Mitel S.C.C. Extensive post-layout simulations show that the oscillation frequency is very sensitive to temperature variations. The sensors proposed require very small power dissipation and silicon area.     

Shape‐memory bioresorbable terpolymer composite with antirestenotic drug

Shape‐memory polymers (SMPs) that combine shape‐memory, biodegradability, and controlled drug release properties are very promising for medical and pharmaceutical application. Moreover, incorporation of antirestenotic drug into SMP biodegradable stent seems to be an interesting solution because of possibility to combine the mechanical support that provides stent and also drug elution. The aim of our study was to analyze the effect of incorporation of sirolimus into poly(l ‐lactide‐co‐glycolide‐co‐trimethylene carbonate) on physicochemical and mechanical properties, degradation, and shape‐memory effect of the terpolymer. For this purpose, sirolimus was incorporated into the terpolymer by injection molding method. It has been demonstrated that drug‐free terpolymer after injection molding characterized insignificant changes in terpolymer composition. Degradation of materials during processing was not observed. Incorporation of drug molecules did not change shape‐memory properties of terpolymer. ¹H‐ and ¹³C‐NMR spectra of poly(lactide‐co‐glycolide‐co‐trimethylene carbonate) confirmed that changes during degradation were similar for terpolymer and terpolymer with sirolimus. Sustained and regular release of sirolimus was observed. The developed material presents potential for biomedical and pharmaceutical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41902.     

Crosstalk among Calcium ATPases: PMCA,SERCA and SPCA in Mental Diseases

Calcium in mammalian neurons is essential for developmental processes, neurotransmitter release, apoptosis, and signal transduction. Incorrectly processed Ca²⁺ signal is well-known to trigger a cascade of events leading to altered response to variety of stimuli and persistent accumulation of pathological changes at the molecular level. To counterbalance potentially detrimental consequences of Ca²⁺, neurons are equipped with sophisticated mechanisms that function to keep its concentration in a tightly regulated range. Calcium pumps belonging to the P-type family of ATPases: plasma membrane Ca²⁺-ATPase (PMCA), sarco/endoplasmic Ca²⁺-ATPase (SERCA) and secretory pathway Ca²⁺-ATPase (SPCA) are considered efficient line of defense against abnormal Ca²⁺ rises. However, their role is not limited only to Ca²⁺ transport, as they present tissue-specific functionality and unique sensitive to the regulation by the main calcium signal decoding protein—calmodulin (CaM). Based on the available literature, in this review we analyze the contribution of these three types of Ca²⁺-ATPases to neuropathology, with a special emphasis on mental diseases.     

Molecular and Cytogenetic Analysis of rDNA Evolution in Crepis Sensu Lato

Although Crepis was the first model plant group in which chromosomal changes were considered to play an important role in speciation, their chromosome structure and evolution have been barely investigated using molecular cytogenetic methods. The aim of the study was to provide a better understanding of the patterns and directions of Crepis chromosome evolution, using comparative analyses of rDNA loci number and localisation. The chromosome base number and chromosomal organisation of 5S and 35S rDNA loci were analysed in the phylogenetic background for 39 species of Crepis, which represent the evolutionary lineages of Crepis sensu stricto and Lagoseris, including Lapsana communis. The phylogenetic relationships among all the species were inferred from nrITS and newly obtained 5S rDNA NTS sequences. Despite high variations in rDNA loci chromosomal organisation, most species had a chromosome with both rDNA loci within the same (usually short) chromosomal arm. The comparative analyses revealed several independent rDNA loci number gains and loci repositioning that accompanied diversification and speciation in Crepis. Some of the changes in rDNA loci patterns were reconstructed for the same evolutionary lineages as descending dysploidy.     

Dielectric properties of BiFeO3 ceramics obtained from mechanochemically synthesized nanopowders

Dielectric behaviour of BiFeO₃ ceramics, obtained by hot-pressing of nanopowders produced by mechanochemical synthesis from Bi₂O₃ and Fe₂O₃ oxides (weight ratio 2:1), was studied in the temperature range 125?C575?K. The ceramics was found to exhibit step-like dielectric response ??*(T) with high permittivity values, similar to the behaviour of materials with giant dielectric permittivity. Three overlapping relaxation processes contribute to the dielectric response: i) relaxation in the low-temperature range (220?C420?K), characterized by activation energy of 0.4?eV, ii) relaxation in the temperature range 320?C520?K with activation energy of 1.0?eV and iii) broad dielectric anomaly in the vicinity of 420?K, which disappears after 1?h annealing at 775?K. The low-temperature relaxation is ascribed to the carrier hopping process between Fe²⁺ and Fe³⁺ ions. The presence of mixed valence of the Fe ions was proved by X-ray photoelectron spectroscopy. Dielectric relaxation in the middle-temperature range is considered as a result of grain boundary effect and internal barrier layers related to Bi₂₅FeO₄₀ phase as verified by X-ray diffraction. The high-temperature dielectric anomaly we relate to short-range hopping of ordered oxygen vacancies.     

Hydrogen production from propane in Rh-impregnated metallic microchannel reactors and alumina foams

Rh-impregnated alumina foams and metallic microchannel reactors have been studied for production of hydrogen-rich syngas through short contact time catalytic partial oxidation (POX) and oxidative steam reforming (OSR) of propane. Effects of temperature and residence time have been compared for the two catalytic systems. Temperature profiles obtained along the central axis were valuable in understanding the different behaviour of the reactor systems. Gas phase ignition occurs in front of the metallic monolith at furnace temperatures above 700 °C, leading to lower hydrogen selectivity. Lowering the residence time below 10 ms for the microchannel monolith increases the syngas selectivity. This probably due to quenching of the gas phase reactions at high linear gas velocity, and suggests that microchannel reactors have potential for isolating kinetic effects and minimising gas phase contributions. The Rh/Al₂O₃ foam systems show higher initial syngas selectivity than the Rh-impregnated microchannel reactors, but deactivate rapidly upon temperature cycling, especially when steam is added as a reactant.     

Estimation of earthworks execution time cost by means of artificial neural networks

The paper presents a methodology for determining earthworks execution time and cost. The accurate determination of the productivity of machines working in sets is a major problem in earthworks execution planning. Earthworks are conducted in random condition and so the parameter values achieved during their realization have a random character. Using an existing database based on measurements carried out on a construction site, an artificial neural network was built. The latter was used to predict productivity for selected sets of machines and to calculate the task execution time and cost. The obtained set of results allows one to select the machinery set optimum with regard to earthworks execution cost or time.     

Does standardization have a negative impact on working conditions?

The aim of this article was to contribute to the discussion about whether standardization has a positive or negative impact on working conditions. The case studies of organizations certified to the quality management standard ISO 9000 served as the empirical base. The article shows that there is no clear and obvious answer about the impact of standardization on working conditions. The consequences for working conditions depend on many variables and may differ considerably from organization to organization. Three primary variables influencing the outcomes for working conditions were identified and discussed: (1) content of the standard, (2) the standardization process, and (3) the degree of standardization. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 383–394, 2007.     

A critical examination of the sodium dodecyl sulfate (SDS) sedimentation test for wheat meals

Sedimentation tests have long been used to characterise wheat flours and meals with the aim of predicting processing and end‐product qualities. However, the use of the sodium dodecyl sulfate (SDS) sedimentation test for durum wheat (AACC International Approved Method 56–70) has not been characterised for hexaploid wheat varieties with a diverse range of protein quality and quantity. This paper reports the variation associated with important method parameters: sample weight, SDS concentration, technician, grinder and screen aperture (particle size). Sedimentation volumes were recorded every 5 min for 30 min and expressed as specific volume, i.e. sediment volume in mL g^?1 meal. Ten diverse hexaploid wheat samples of markedly different protein quality and quantity were examined. The SDS sedimentation assay was shown to be highly robust and reproducible, with ANOVA (analysis of variance) model R² values greater than 0.98 (individual time points). The procedure delineated soft and hard hexaploid wheat samples based on a combination of protein quantity and quality. Sample weight (if corrected to unit weight basis), recording time of at least 10 min, SDS stock concentration of at least 10 g L^?1 (final), grinder type and screen aperture were minor sources of variation in SDS sedimentation volume relative to the effects due to differences among wheat samples. Interactions among ANOVA model terms were of relatively minor importance. Published in 2007 by This article is a US Government work and is in the public domain in the USA.