Evaluation of polyesters from renewable resources as alternatives to the current fossil-based polymers. Phase transitions of poly(butylene 2,5-furan-dicarboxylate)

Poly(butylene 2,5-furan dicarboxylate) (PBF) is an alipharomatic polyester that can be prepared using monomers derived from renewable resources such as 2,5-furan dicarboxylic acid and 1,4-butanediol. In the present work the thermal behavior of PBF was studied. Multiple melting was observed during heating traces of samples isothermally crystallized from the melt using differential scanning calorimetry (DSC). The wide angle X-ray diffraction (WAXD) patterns did not reveal the presence of a second crystal population, or a crystal transition upon heating. DSC study showed that the phenomena are closely related to recrystallization. Temperature modulated DSC (TMDSC) tests indeed evidenced enhanced recrystallization. The equilibrium melting point was estimated to be 184.5 °C using the linear Hoffman–Weeks extrapolation. The heat of fusion of the pure crystalline polymer was found equal to 129 J/g or (27.35 kJ/mol), a little lower than that of PBT. The Lauritzen–Hoffman secondary nucleation theory was used and the surface energy values and the work of chain folding were found to be comparable to those of PBT, but quite lower than those of poly(ethylene terephthalate) (PET). The non-isothermal crystallization on cooling and the cold-crystallization of quenched samples were also studied. Condensed spherulites were observed on isothermal crystallization under large supercoolings by using polarized optical microscopy (POM), while the spherulites turned to ring-banded morphology at higher temperatures. In every case the nucleation density was high.     

Ein Modell zur Berechnung des Verformungsverhaltens von horizontal hochzyklisch beanspruchten Pfählen

A model for the behavior of horizontally high‐cycle loaded piles For the prediction of the deformation for long or intermediate long piles under lateral high cycle load, embedded in non‐cohesive soil, a simplified engineering model for drained conditions is developed based on the high cycle accumulation (HCA) model of Niemunis , Wichtmann and Triantafyllidis [1]. The monotonic soil deformation under static load is approximated by elastic springs, placed around the pile, whereas the accumulation of soil deformations under cyclic loading is modelled by viscous dashpots (cyclic creep) according to the HCA model. In most instances this contemplation is physically validated by element tests. In conjunction with the pile the spring‐dashpot elements represent an elastically embedded beam system. Two versions of the model with a two‐sided arrangement of springs and dashpots on the Lee‐ and Luv‐side and a one‐sided arrangement only on the Lee‐side will be presented. The pile displacement prediction of the model is compared with the results obtained by existing engineering models already known in the literature and the solution of a 3‐D‐finite element simulation with the HCA model.     

Mutagenicity and polycyclic aromatic hydrocarbons analysis of ambient airborne particles collected in Athens, Greece

Samples of airborne particulates from the Athens atmosphere were examined for mutagenicity and various polycyclic aromatic hydrocarbons (PAH). Extracts induced linear, dose-related increases in TA98 His+ revertants in the Ames/Salmonella assay and contained average benzo[a]pyrene (BaP) levels of 3.9 ng/m3 of air. The levels of revertants/m3 of the samples showed a linear relation to their BaP and benzo[b]-(BbF) + benzo[k]-fluoranthene (BkF) concentrations and were higher in areas with dense traffic than in industrial areas. It is suggested that the atmosphere of Athens favours the formation of secondary direct-acting mutagens due to the oxidation and nitration of PAH by ozone and nitrogen oxides, which are more abundant in the late spring months.     

The ARM Cortex-A8 Microprocessor IEEE Std 1500 Wrapper

This article describes the test wrapper implementation of a popular embedded microprocessor, along with an automated approach for verifying the wrapper's compliance to the standard.     

An interfacing circuit for piezoresistive pressure sensors with frequency output

An interfacing circuit for piezoresistive pressure sensors based on the CMOS operational floating amplifier in a current conveyor configuration is presented. The main advantages of the proposed circuit include the use of only two piezoresistors with high common-mode rejection ratio, using an instrumentation amplifier based on a second-generation current conveyor (CCII) and temperature compensation. The circuit has frequency output proportional to the applied pressure with high linearity and temperature dependence less than 150ppm°C^?1. Experimental results, using the interfacing circuit and a commercial silicon pressure sensor, are included to demonstrate its performance.     

Production and Quality Assessment of a Smoked Tuna (Euthynnus affinis) Product

ABSTRACT: The sensory, instrumental, and chemical profile of a smoked tuna product comparable and competitive to smoked turkey and pork was studied, based on four experimental factors. Despite their different brining times, all brined, sliced portions of tuna were assessed by panelists as quite acceptable products in terms of firmness, juiciness, color, and saltiness. Protein denaturation seemed to be affected by the brining time. Lipid oxidation seemed quite extensive; the ratio of C22:6n-3/C16:0 was decreased at 15% and 20%. Histamine content was between 3.7 mg/ 100 g and 7.5 mg/100 g. After 3 mo in refrigeration, the aerobic bacteria was 19.10⁵ to 250.10⁶ in contrast to the unprocessed samples at 28.10⁵.     

Low cholesterol along with inflammation predicts morbidity and mortality in hemodialysis patients

Low and not high cholesterol seems to predict high mortality in hemodialysis (HD) patients. The confirmation of this reverse epidemiology as well as its possible interconnection with the increased inflammatory activity observed in this population is being explored in the present study. A group of 136 HD patients was prospectively studied for 2 years, and cardiovascular disease (CVD) as well as all-cause mortality and morbidity were recorded. Baseline lipid profile, inflammatory status, and patients' characteristics were studied as potential survival and hospitalization predictors. During the 24-month follow-up, 21 deaths (52.4% due to CVD) and 38 hospitalizations (55.3% due to CVD) were recorded. In multivariate Cox regression analysis, decreased interleukin-10 (IL-10) and decreased total serum cholesterol (TChol) were the only independent predictors of CVD mortality while C-reactive protein and decreased TChol predicted all-cause mortality. Interleukin-10 at baseline was 11.29 ± 21.49 vs. 5.51 ± 4.57 pg/mL (P<0.018) and TChol 167.37 ± 47.84 vs.122.04 ± 26.48 mg/dL (P<0.000) in survivors vs. nonsurvivors from CVD, while C-reactive protein at baseline was 9.37 ± 11.54 vs. 23.15 ± 18.76 mg/L (P<0.000) and TChol 169.26 ± 46.42 vs. 133.26 ± 46.33 mg/dL (P<0.003) in survivors vs. nonsurvivors from any cause of death. Using the same method of statistical analysis, IL-6 and decreased soluble gp130 (sgp130)—an antagonist of IL-6 action—were found to be the only independent prognostic factors for hospitalization due to CVD while decreased soluble gp130 remained the sole predictor of hospitalization due to any cause. In conclusion, reverse epidemiology regarding cholesterol is confirmed in the present study. Furthermore, inflammatory activity also predicts, independently of or in conjunction with low-cholesterol, CVD and all-cause morbidity and mortality in HD patients.     

Noise optimised charge-sensitive CMOS amplifier for capacitive radiation detectors

A low-voltage, low-noise, charge-sensitive preamplifier (CSA) for particle tracking using a silicon strip detector was designed. The preamplifier was optimised in terms of the total output noise performance using a noise minimisation technique based on the MOSFET noise small signal equivalent circuit and readout front-end noise optimisation criteria valid in the strong inversion region. The preamplifier was designed and fabricated in a 0.35 m CMOS process by Austria Mikro Systeme for a specific silicon strip detector of 2 pF capacitance for X-ray spectroscopy. The circuit exhibits satisfactory performance compatible to the specific low-energy radiation detection application. Particularly, the CSA provides an equivalent noise charge of 254 e⁺13.5+e^-/pF, consumes 165 muW and achieves an output conversion gain equal to 2.81 mV/fC and a linearity <0.57 . Analysis is supported by extensive measurement results confirming the circuit characteristics and their flexibility to be used in a variety of readout applications.     

Design of voltage-mode and current-mode computational circuits using floating-gate MOS transistors

In this paper, we present voltage-mode and current-mode computational circuits using floating-gate MOS (FGMOS) transistors, operating in saturation region. The circuits are designed using two FGMOS basic-cells, each one formed by three floating-gate transistors with common source. The first basic cell is connected in voltage mode, while the second one is connected in current-mode configuration in order to implement voltage and current-mode circuits, respectively. Using the basic FGMOS cells, voltage and current squarers, four-quadrant multipliers and a current square rooter are designed. Mismatches and distortion analysis for the proposed circuits have been elaborated. The most important advantages are, rail-to-rail dynamic input range, low distortion and ability for either differential or single-ended input signals. Simulation results demonstrate the feasibility and the accuracy of the circuits.