Thermal stability evaluation of polypropylene protected with grafted amine

Summary Polypropylene containing a grafted amine as oxidation protector was subjected to γ-irradiation for the evaluation of thermal stability. Several formulations were prepared containing hindered amine, Sanduvor PR 31 (0.1, 0.2 and 0.3% w/w) and CaCO₃ (0.6% w/w). The stability assessment was carried out in air by oxygen uptake procedure under isothermal and isobaric conditions (165 °C and normal pressure, respectively). The exposure doses were placed in the range from 0 to 70 kGy. The changes appeared in the main kinetic parameters (oxidation induction time and oxidation rate) evaluated for thermal degradation of irradiated PP specimens are presented and the stability analysis is explained starting from the behaviour differences of various formulations of radiation processed polypropylene. On the low dose range, the drop in thermal stability of modified polypropylene films occurs more abrupt than it was observed for the samples irradiated at higher doses.     

Finding the Collineation between Two Projective Reconstructions

The problem of finding the collineation between two 3D projective reconstructions has been proved to be useful for a variety of tasks such as calibration of a stereo rig and 3D affine and/or Euclidean reconstruction. Moreover, such a collineation may well be viewed as a point transfer method between two image pairs with applications to visually guided robot control. Despite this potential, methods for properly estimating such a projective transformation have received little attention in the past. In this paper we describe linear, nonlinear, and robust methods for estimating this transformation. We test the numerical stability of these methods with respect to image noise, to the number of matched points, and as a function of the number of outliers. Finally, we devise a specialized technique for the case where 3D Euclidean coordinates are provided for a number of control points.     

A Boussinesq model for pressure and flow velocity waves in arterial segments

We derive a nonlinear model for the pressure and flow velocity wave propagation in an arterial segment. We then study the transmission and reflection of pulses at bifurcation. We observe a linear dependence of the transmitted speeds to the incoming speeds, and similarly for the reflected speeds. We propose a method for validating the numerical results obtained from this model against real data.     

Programs with lists are counter automata

We address the problem of verifying programs manipulating one-selector linked data structures. We propose and study in detail an application of counter automata as an accurate abstract model for this problem. We let control states of the counter automata correspond to abstract heap graphs where list segments without sharing are collapsed, and use counters to keep track of the number of elements in these segments. As a significant theoretical result, we show that the obtained counter automata are bisimilar to the original programs. Moreover, from a practical point of view, our translation allows one to apply efficient automatic analysis techniques and tools developed for counter automata (integer programs) in order to verify both safety as well as termination of list-manipulating programs. As another theoretical contribution, we prove that if the control of the generated counter automata does not contain nested loops (i.e., these automata are flat), both safety and termination are decidable for the original programs. Subsequently, we generalise our counter-automata-based model to keep track of ordering properties over lists storing ordered data. Finally, we show effectiveness of our approach by verifying automatically safety as well as termination of several sorting programs.     

Novel Tunnel‐Contact‐Controlled IGZO Thin‐Film Transistors with High Tolerance to Geometrical Variability

Thin insulating layers are used to modulate a depletion region at the source of a thin‐film transistor. Bottom contact, staggered‐electrode indium gallium zinc oxide transistors with a 3 nm Al₂O₃ layer between the semiconductor and Ni source/drain contacts, show behaviors typical of source‐gated transistors (SGTs): low saturation voltage (V_{D_SAT} ≈ 3 V), change in V_{D_SAT} with a gate voltage of only 0.12 V V^?1, and flat saturated output characteristics (small dependence of drain current on drain voltage). The transistors show high tolerance to geometry: the saturated current changes only 0.15× for 2–50 µm channels and 2× for 9‐45 µm source‐gate overlaps. A higher than expected (5×) increase in drain current for a 30 K change in temperature, similar to Schottky‐contact SGTs, underlines a more complex device operation than previously theorized. Optimization for increasing intrinsic gain and reducing temperature effects is discussed. These devices complete the portfolio of contact‐controlled transistors, comprising devices with Schottky contacts, bulk barrier, or heterojunctions, and now, tunneling insulating layers. The findings should also apply to nanowire transistors, leading to new low‐power, robust design approaches as large‐scale fabrication techniques with sub‐nanometer control mature.     

Rational design of potentiometric trace level ion sensors. A Ag+-selective electrode with a 100 ppt detection limit

Submicromolar to picomolar lower detection limits have recently been obtained with various polymer membrane ion-selective electrodes by minimizing biases due to ion fluxes through the membrane. For the best performance, the compositions of the membrane and inner solution should be optimized for each application. Given the number of parameters to be adjusted, it has been difficult to find the best parameters for a target sample. In this paper, a much simplified and more practical steady-state model of zero-current ion fluxes is derived, which is based on measurable parameters. The model allows one to predict achievable lower detection limits for a membrane with given selectivities. It can also be used to predict the optimal composition of the inner filling solution for the measurement of samples with a known, typical ionic background. Selectivity coefficients of monovalent and divalent analyte ions required for desired detection limits in drinking water are calculated. As an application of the proposed general recipe, a silver-selective electrode is developed on the basis of the ionophore O,O'-bis[2-(methylthio)ethyl]-tert-butylcalix[4]arene. With the predicted optimal composition of the inner electrolyte, its lower detection limit is found to be 10(-9) M or 100 ppt Ag+ with an ionic background of 10(-5) M LiNO3, which is very close to the expected value.     

Zn–Al–CO<Subscript>3</Subscript> layered double hydroxides prepared from a waste of hot-dip galvanizing process

Hot-dip galvanizing process is used worldwide to protect the steel or iron pieces from corrosion. This process is a large generator of waste, considered one of the so-called dirty industries. One of the important wastes, in terms of quantity, is zinc ash that contains a mixture of metallic zinc and zinc oxide with a total content of zinc between 70 and 90%. The aim of this study is the preparation and characterization of a series of Zn _R –Al–CO₃ (R?=?2–4) layered double hydroxides (LDH) by using as zinc precursor the zinc chloride obtained after hydrochloric acid leaching of fine-grained zinc ash. Results presented herein clearly demonstrated that characteristics of the synthesized samples are close to those of similar materials synthesized starting from analytical grade reagents. At the same time, it was observed that impurities existent in the zinc chloride solution prepared by zinc ash leaching (Pb, Fe, Ca), are found at traces in the synthesized LDH materials; therefore, they have no significant influence on the obtained LDH structure and properties. By this approach, several important benefits may be simultaneously achieved: (1) preventing the pollution associated with hot-dip galvanizing process wastes, (2) obtaining of valuable products with minimized costs, keeping in mind that LDH have multiple utilizations at industrial scale, (3) saving energy and material costs, and (4) increase of product competitiveness with respect to the circular economy.     

A personal mobile DRM manager for smartphones

In this paper we report on our experience in building the experimental Personal Digital Rights Manager for Motorola smartphones, an industry first.Digital Rights Management allows producers or owners of digital content to control the manner in which the content is consumed. This may range from simply preventing duplication to finer access policies such as restricting who can use the content, on what devices, and for how long. In most commercial DRM systems, the average end user plays the role of content consumer, using DRM protected content made available by a service. Here we present a personal digital rights system for mobile devices where the end user has the ability to place DRM protection and controls on his or her own personal content.We designed the personal DRM system to allow users of a mobile device to transparently define controls and generate licenses on custom content and securely transfer them to other mobile devices. A user is able to define and restrict the intended audience and ensure expiration of the content as desired. Compatible devices automatically detect each other and exchange credentials. The personal DRM system on each device safely enforces the content usage rules and also handles moving licenses between devices while preventing leakage of content. We implemented a prototype of our system on Motorola E680i smartphones.     

Anti-patterns for rule-based languages

Negation is intrinsic to human thinking and most of the time when searching for something, we base our patterns on both positive and negative conditions. This should be naturally reflected in software that provide pattern-based searches. We would like for example to specify that we search for white cars that are not station wagons, or that we search for a list of objects that does not contain two identical elements.     

Spatial Networks of Hybrid I/O Automata for Modeling Excitable Tissue

We propose a new biological framework, spatial networks of hybrid input/output automata (SNHIOA), for the efficient modeling and simulation of excitable-cell tissue. Within this framework, we view an excitable tissue as a network of interacting cells disposed according to a 2D spatial lattice, with the electrical behavior of a single cell modeled as a hybrid input/ouput automaton. To capture the phenomenon that the strength of communication between automata depends on their relative positions within the lattice, we introduce a new, weighted parallel composition operator to specify the influence of one automata over another.The purpose of the SNHIOA model is to efficiently capture the spatiotemporal behavior of wave propagation in 2D excitable media. To validate this claim, we show how SNHIOA can be used to model and capture different spatiotemporal behavior of wave propagation in 2D isotropic cardiac tissue, including normal planar wave propagation, spiral creation, the breakup of spirals into more complex (potentially lethal) spatiotemporal patterns, and the recovery of the tissue to the rest via defibrillation.