Batch foaming of chain extended PLA with supercritical CO2: Influence of the rheological properties and the process parameters on the cellular structure

This study has been dedicated to the foaming of modified poly (lactic acid) with supercritical CO₂. The first part of this work consisted in a rheological modification of neat PLA through chain extension. Improvement of the melt viscosity and elasticity has been achieved by the use of an epoxy additive during a reactive extrusion process. Rheological characterizations confirmed an increase of the melt strength due to this chain extension process. Foaming was then performed on the neat and modified PLAs using a batch process with supercritical CO₂ as blowing agent. The investigation of the foaming temperature revealed an enlarged processing window for modified PLAs compared to neat PLA. Depending on the foaming parameters, foams with a cellular structure ranging from macro scale to micro scale have been obtained. A concomitant effect of the CO₂-plasticization and the crystallisation on the melt rheology could explain this wide range of cellular morphologies.     

A New Sorbent for Selective Separation of Metal: Polyethylenimine Methylenephosphonic Acid

Abstract

A new sorbent, the polyethylenimine methylenephosphonic acid (PEIMPA), was synthesized from commercially available polyethylenimine. After characterization by (¹H, ¹³C, ³¹P) NMR, elementary analysis, UV/VIS and FTIR, the new ion exchange polymer PEIMPA has been investigated in liquid – solid extraction of a mixture of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II), and Zn(II) cations from a mineral residue of zinc ore dissolved in nitric acid. The selectivity of this polymer was studied as a function of pH. PEIMPA can sorb much higher amounts of Fe ion than Cd, Co, Cu, Ni, Pb, and Zn ions. The recovery of Fe(III) is almost quantitative. Because of this remarkable affinity, the PEIMPA resin has the potential for application in several fields. Further studies of the polymer are in progress.     

A new approach for $$H_{\infty }$$ H ∞ deconvolution filtering of 2D systems described by the Fornasini–Marchesini and discrete moments

Pattern Analysis and Applications - This study proposes a new approach of $$H_{\infty }$$ deconvolution filtering of 2D system described by Fornasini–Marchesini model and Tchebichef moments....     

Dispersion of multi-walled carbon nanotubes in biodegradable poly(butylene succinate) matrix

This communication describes the preparation, characterization and properties of biodegradable poly(butylene succinate) (PBS)/multi-walled carbon nanotubes (MWCNTs) nanocomposite. Nanocomposite was prepared by melt-blending in a batch mixer and the amount of MWCNTs loading was 3 wt%. State of dispersion-distribution of the MWCNTs in the PBS matrix was examined by scanning and transmission electron microscopic observations that revealed homogeneous distribution of stacked MWCNTs in PBS matrix. The investigation of the thermomechanical behavior was performed by dynamic mechanical thermal analysis. Results demonstrated substantial enhancement in the mechanical properties of PBS, for example, at room temperature, storage flexural modulus increased from 0.64 GPa for pure PBS to 1.2 GPa for the nanocomposite, an increase of about 88% in the value of the elastic modulus. The tensile modulus and thermal stability of PBS were moderately improved after nanocomposite preparation with 3 wt% of MWCNTs, while electrical conductivity of neat PBS dramatically increased after nanocomposite formation. For example, the in plane conductivity increased from 5.8 x 10(-9) S/cm for neat PBS to 4.4 x 10(-3) for nanocomposite, an increase of 10(6) fold in value of the electrical conductivity.     

FutureHome: An integrated construction automation approach

This article presents the results of the FutureHome project, the first global project in the construction industry that introduces the ICA concept. The design, planning, and onsite robotization stages of house-building construction have been presented. The main advantage introduced by FutureHome is the integration of the three stages under common data and concept. The article focuses on the architectural design of residential houses and office buildings by using prefabricated modules. The design takes into account the prefabrication and onsite assembly. For efficient construction, a global planning strategy has been developed that integrates the prefabrication, transportation, and onsite processes. Finally, the robotized crane for the assembly of big 3-D modules with small tolerances is presented. The control strategy for adequate assembly with the reduction of positioning errors, rotation errors, and swinging of the modules, has been developed and tested     

Extending TINA with Secure On-Line Accounting Services

Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of the current centralized service control and service data model in an IN (Intelligent Network). It is becoming increasingly clear that the future sophisticated telecommunication services, e.g., multimedia, and multi-party conferencing, breaking away from the traditional telephony call model will need the solutions for rapid and efficient introduction, deployment, operations, and management.In this paper, we discuss accounting features and requirements, as well as security services in the TINA management context. We will introduce and present an implementation of a model for a security management, based on secure objects, cryptography and certificate distribution. In order to provide secure services, secure objects that have security functionality, such as authentication and access control, have been defined. Secure objects in our model are CORBA objects. The security domain is also called SBS (Security Base Server), provides security services and has an SMIB (Security Management Information Base) that contains security policies, cryptographic algorithms, and other relevant information. A prototype has been implemented and some experimental results are presented.     

CONTROL OF ALUMINUM ROLLING MILLS

The aluminum rolling mills suffer from the presence of large time-delay-to-time-constant ratios. Conventional proportional-integral-derivative (PID) controllers and their variants do not provide adequate performance when used to control these types of processes. Advanced control strategies are needed. The Smith predictor (SP) is a relatively simple control scheme that is used for time delay compensation. In this paper, the SP has been used to control a rolling mill, and its performance has been compared with that obtained from a conventional proportional plus integral (PI) controller. In addition, the sensitivity of the SP to modeling errors and changing plant conditions was investigated. As expected, it was found that, for the perfect model case, the SP provides superior performance as compared to the classical PI. The superiority of the SP is maintained as long as the modeling errors are not too large. The PI algorithm is much more robust than the SP control scheme.     

Supervised nonlinear spectral unmixing using a postnonlinear mixing model for hyperspectral imagery

This paper presents a nonlinear mixing model for hyperspectral image unmixing. The proposed model assumes that the pixel reflectances are nonlinear functions of pure spectral components contaminated by an additive white Gaussian noise. These nonlinear functions are approximated using polynomial functions leading to a polynomial postnonlinear mixing model. A Bayesian algorithm and optimization methods are proposed to estimate the parameters involved in the model. The performance of the unmixing strategies is evaluated by simulations conducted on synthetic and real data.     

Chemical Composition,Physical Properties,and the Oxidative Stability of Oil Bodies Extracted From Argania spinosa

Oil bodies (OB) were extracted from argan kernels using an aqueous extraction method. The composition of OB revealed its lipid profile, which had a high content of stearic and palmitic acid. Besides, evidence suggested an association between OB and tocopherols. The physical properties of argan OB (AOB) showed that their size was around 1.9 μm and the ζ‐potential went from +17.7 mV at pH 2.0 to ?32.25 mV at pH 8, with an isoelectric point around pH 5.1. OB were stable and small at pH 2.0, 7.0, and 8.0 but large near the pI. Additionally, AOB were stable against aggregation/coalescence even in high salt concentrations, and also against thermal processing (95 °C) with only a change in their interfacial properties. AOB emulsion showed interesting oxidative stability at different storage temperatures and heat treatment. Heat treatment and storage at low temperature preserved oleosins from degradation by the endogenous enzyme, and H‐oleosin 15 kDa resisted hydrolyzation even at a high storage temperature for 2 weeks.