Interactions in blends of dendronized polymeric nanocomposites with some common drugs

Poly(diethylaminoethyl methacrylamide) (PEAM), a dendronized polymer, was synthesized according to classical procedures. Monomers and polymers were characterized by spectroscopic measurements. The results obtained were in agreement with the expected chemical structure. The phase behavior of blends of PEAM with diclofenac (DCF), ibuprofen (IBU) , and paracetamol (PCM) were studied by different experimental techniques. FT‐IR, UV‐Vis, DSC , and TGA measurements suggested important interactions between the blended components. Thermogravimetric analysis (TGA) indicated the temperature at which the dendronized polymer released a small molecule. AFM measurements and molecular dynamics (MD) simulations were used to better understand the nature of the interactions and to estimate the distance between the components of the blends to explain the interaction involved. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42450.     

Tunable mechanical properties of core‐shell polymers of poly(hexyl methacrylate) and poly(methyl methacrylate) by semicontinuous heterophase polymerization

The synthesis of core/shell polymers with tunable mechanical properties made of poly(hexyl methacrylate) (PHeMA) and poly(methyl methacrylate) (PMMA) by a two‐stage semicontinuous heterophase polymerization, is presented here. This polymerization technique is characterized by employing low surfactant concentrations to produce large polymer‐to‐surfactant ratios. In this process, monomer is added in a continuous low rate to achieve monomer starved conditions, allowing to control particle size (usually smaller than 50 nm). To modulate the mechanical properties, the weight ratio of core/shell polymers are varied from 10/90 to 90/10 for direct and reverse compositions, respectively. Conversion was followed gravimetrically; nanoparticles were characterized with quasi‐elastic light scattering, IR spectroscopy, differential scanning calorimetry, transmission electron microscopy, and mechanical tests (tensile and hardness). Highly stable latex formed of nanoparticles, with high conversions are obtained. Tensile tests show that the mechanical properties can be tuned according to core/shell composition, mainly in the system formed by PMMA/PHeMA. These results are explained in terms of core‐and‐shell polymers location, composition and hardness. As expected, an increment in concentration of PMMA produces a more rigid material independently of its position. POLYM. ENG. SCI., 59:365–371, 2019. © 2018 Society of Plastics Engineers     

An overview of the enzyme potential in bioenergy‐producing biorefineries

Biorefineries are considered as an integrative thinking that focuses on the possibility of obtaining as many added‐value products as technically and economically feasible. However, in practice most biorefineries comprise only enzymatic or chemical pretreatment followed by biofuel generation. The drop in oil prices may menace the development of this young industry, as has happened before in history. This has become a fundamental reason for which the biofuel industry should not consider only biofuels production, but enzyme and non‐fuel based chemicals as well. Hence, this work aims at overviewing the most important enzymes involved in biotechnological processes and to describe their role in biorefineries. Bioethanol, biogas and biodiesel biorefineries are overviewed, along with the integrated and industrial types. Finally separation and purification processes in biorefineries are discussed. © 2016 Society of Chemical Industry     

Stability analysis of interconnected power systems coupled withmarket dynamics

The use of market mechanisms to determine generation dispatch, and the natural tendency to seek improved economic efficiency through rapid market updates, raises a critical issue. As the frequency of market-based dispatch updates increases, there will inevitably be interaction between the dynamics of markets determining the generator dispatch commands, and the physical response of generators and network interconnections. This paper examines questions of stability in such coupled systems by means of numeric tests using various market update models, (including detailed generator/turbine/governor dynamics) for the New England 39 bus test system. The results highlight the nature of potential instabilities and show the interaction modes between physical and market quantities through eigen-analysis. Understanding of potential modes of instability in such coupled systems is crucial both for designing suitable rules for power markets, and for designing physical generator controls that are compatible with market-based dispatch     

Reliability Estimation for Accelerated Life Tests Based on a Cox Proportional Hazard Model with Error Effect

In this paper, a Cox proportional hazard model with error effect applied on the study of an accelerated life test is investigated. Statistical inference under Bayesian methods by using the Markov chain Monte Carlo techniques is performed in order to estimate the parameters involved in the model and predict reliability in an accelerated life testing. The proposed model is applied to the analysis of the knock sensor failure time data in which some observations in the data are censored. The failure times at a constant stress level are assumed to be from a Weibull distribution. The analysis of the failure time data from an accelerated life test is used for the posterior estimation of parameters and prediction of the reliability function as well as the comparisons with the classical results from the maximum likelihood estimation. Copyright © 2017 John Wiley & Sons, Ltd.     

Robust MPC for tracking zone regions based on nominal predictions

This paper deals with the problem of robust tracking of target sets using a model predictive control (MPC) law. Real industries applications often require a control strategy in which some system outputs are controlled within specified ranges or zones (zone control), while some others variables – possibly including input variables – are steered to fixed target or setpoint. From a theoretical point of view, the control objective of this kind of problem can be seen as a target set (in the output space) instead of a target point, since inside the zones there are no preferences between one point or another. This problem is particularly interesting in case of additive disturbances which might push the outputs out of the zones. In this work, a stable robust MPC formulation for constrained linear systems, based on nominal predictions is presented. The main features of this controller are the use of nominal predictions, restricted constraints and the concept of distance from a point to a set as offset cost function. The controller ensures both recursive feasibility and local optimality. The properties of the controller are shown in a simulation test, in which we consider a subsystem of an industrial FCC system.     

Improving the Security of Downloadable Java Applications With Static Analysis

Today, most middle-end mobile phones embed a Java runtime environment that can execute programs downloaded on the network by the user. This new functionality creates great opportunities for new services but also brings the full range of risks that existed on the personal computer to the phone.Telecommunication operators are the last warrant of the quality of the software downloaded by their customers and might sign the applications they trust. Unfortunately they have little evidence to check the quality of the contents of the jammed bytecode they receive from developers. The traditional evaluation process relies mostly on the manual testing of the software on actual terminals. But this is not adapted for security properties.MATOS (Midlet Analysis TOol Suite) is a static analysis tool that checks the possible values passed to some identified methods directly on the compiled application. It is used by the test teams of the mobile operator Orange to check what kind of connections are opened by MIDP applications. We will present the security requirements we want to check, how MATOS helps to ensure them and how the necessary analysis are performed using a combination of (rather) well-known analysis techniques.     

AGENT-BASED SIMULATION FOR BORDER CROSSING MODELING

The aim of this study is to build a computational model to simulate border crossing. Since the 19th century, many theories have been applied to the study of international migration phenomena. These theories cover sociological, economical, and cultural aspects. All the theories aim at estimating the magnitude of population movements. Multi-Agent Systems (MAS) are presented as a new methodological approach to model and foresee the process of migration. This article discusses how legal aspects can also be treated from a computational point of view. When a migrant reaches the border checkpoint, he/she must deal with the legislation of the destination country, which is applied by the border security police. This interaction at the microlevel between the migrant and the border agent is based on the definition of a behavioral model that includes the migrant's profile, the border officer's profile, and the legislation that rules the border crossing. With this model, the effects at the macrolevel of new policies (which are usually difficult to predict) can be estimated. Changes in legislation or in strictness in applying the existing law at certain borders can influence migration trends; for example, the choice of route. This study presents the main features of the computational model that has been developed to recreate the border-crossing scenario in a Multi-Agent System.     

Effect of temperature on the aerobic degradation of vitamin C in citric fruit juices

By means of the method of the 2,4-dinitrophenylhydrazine the total ascorbic acid content in lima, lemon, tangerine and grapefruit juices, fresh and kept at four temperatures and different times, was determined. It was confirmed that in all the cases, the aerobic degradation of ascorbic acid follows a kinetic first order and that the values of the reaction rate are different between species and even between varieties of lemon and tangerine. The values of the equation terms are reported, and examples of application given. Within a range from 20 degrees to 92 degrees C, the effect of temperature on the velocity of the ascorbic acid degradation is described satisfactorily following the Arrhenius equation, in accordance with which, the corresponding values of activation energy are calculated to compare them with other published values. With the simple application of the method, in two steps, and considering that the L-ascorbic acid and the L-dehydroascorbic acid are predominant, the results can be used to calculate the vitamin C losses in citric fruit juices, indicated when they are processed by traditional thermal treatments.