Automation of data processing of the results of the chemical experiment on modeling the production of synthetic rubber using Microsoft Excel

The article presents an approach to the processing of chemical experiment’s data using a Microsoft Excel software. Instead of storing the experiment data in text files, it is proposed to use a Microsoft Excel file of a certain structure. A macro has been developed to automate the process of transferring data from text files to a common file. The described approach can be applied when solving problems accompanied by storing a large amount of statistical data, which can be obtained as a result of natural or computational experiments. The macro has been tested on the data of a laboratory and numerical experiment on the synthesis of a styrene-butadiene copolymer. This copolymer is formed as a result of carrying out the process of copolymerization in continuous mode in a cascade of continuous stirred tank reactors. The results of the experiment are the characteristics of the formed product for each reactor of the cascade at the end of each hour of process modeling. Transferring data into a single file of a certain structure allows you to graphically present the results of the experiment and facilitates further analysis of the characteristics of the product being studied, depending on the formulation and process conditions.

A Study of Cold Roll Forming Technology and Peak Strain Behavior of Asymmetric Corrugated Channels

The peak strain (PS) of sheet metal highly affects the process design and the quality of roll formed product. Different from the traditional roll forming technology (RFT) that all the cross section contours of the product are rolled simultaneously, a symmetric RFT is developed with respect to the corrugated channels under the study to avoid defects like tearing, twist and redundant deformations. The behaviors of their peak strains are subsequently simulated with Finite Element (FE), and the effects of three factors of the rolling speed, friction coefficient and the bending angle of roll are analyzed, respectively. Finally, both the rationality of RFT and the accuracy of final rolled product are verified by experiments. Results show that for two roll forming channels at the same time, even under the equal bending angles and the pressures of rolls, their maximum peak strains are also distinguished for their different channel widths. The maximum PS of the narrow channel is significantly larger than that of the wide, and the closer to the middle channel, the greater the PS of the narrow channel, which is on the right of bending angle of the trough. Moreover, the maximum PS is dominant by the friction coefficient and bending angle of the first forming pass. This can provide a reference in the design of RFT and improving the quality of the final rolled corrugated channels.

STUDY OF MOLECULAR CHARACTERISTICS OF THE PRODUCT OF ISOPRENE POLYMERIZATION ON A NEODYMIUM-CONTAINING CATALYTIC SYSTEM BASED ON MODELING BY THE MONTE-CARLO METHOD

В статье предложен алгоритм моделирования периодического процесса полимеризации, основанный на методе Монте-Карло. Апробация алгоритма осуществляется на примере процесса растворной полимеризации изопрена в присутствии каталитической системы на основе хлорида неодима, лежащей в основе промышленного производства изопренового синтетического каучука. В основе алгоритма лежит имитация роста каждой макромолекулы формируемого полимера и ее отслеживание. Построенная модель позволяет исследовать молекулярно-массовые характеристики полимера в зависимости от конверсии мономеров, проводить расчет молекулярно-массового распределения получаемого продукта в любой момент времени ведения процесса. На основе предложенного алгоритма разработан программный продукт для прогнозирования изменения характеристик образующегося полимера в динамике. The article proposes an algorithm for modeling a batch process of polymerization based on the Monte Carlo method. The algorithm is tested on the process of solution polymerization of isoprene in the presence of a catalytic system based on neodymium chloride. This process underlies the industrial production of isoprene synthetic rubber. The algorithm is based on the imitation of the growth of each macromolecule of the formed polymer and tracking the processes occurring with it. The constructed model makes it possible to study the molecular weight characteristics of the polymer depending on the conversion of monomers, to calculate the molecular weight distribution of the formed product at any time during the process. Based on the proposed algorithm, a software product has been developed for predicting changes in the characteristics of the formed polymer in dynamics.

Single-Step Shear-Based Deformation Processing of Electrical Conductor Wires

Commercial electrical conductor wires are currently produced from aluminum alloys by multi-step deformation processing involving rolling and drawing. These processes typically require 10 to 20 steps of deformation, since the plastic strain or reduction that can be imposed in a single step is limited by material workability and process mechanics. Here, we demonstrate a fundamentally different, single-step approach to produce flat wire aluminum products using machining-based deformation that also ensures adequate material workability in the formed product. Two process routes are proposed: (1) chip formation by free-machining (FM), with a post-machining, light drawing reduction (<20%) to achieve desired finish and (2) constrained chip formation by large strain extrusion machining (LSEM). Using commercially pure aluminum conductor alloys (Al 1100 and EC1350) as representative material systems, we demonstrate key features of the machining-based processing, including (a) single-step processing to achieve flat wire geometries, (b) surface finish (Ra = 0.2 to 1.0 μm) comparable to that of commercial wire products made by drawing/rolling, (c) deformation control independent of wire size, and (d) hardness increases of 50–150% over that of annealed wires, while retaining high electrical conductivity (>56% IACS). The wire microstructure, which can also be varied via the large-strain deformation parameters, is correlated with mechanical and electrical properties. Implications for commercial manufacture of flat wire products are discussed.

Movable Die and Loading Path Design in Tube Hydroforming of Irregular Bellows

Manufacturing of irregular bellows with small corner radii and sharp angles is a challenge in tube hydroforming processes. Design of movable dies with an appropriate loading path is an alternative solution to obtain products with required geometrical and dimensional specifications. In this paper, a tube hydroforming process using a novel movable die design is developed to decrease the internal pressure and the maximal thinning ratio in the formed product. Two kinds of feeding types are proposed to make the maximal thinning ratio in the formed bellows as small as possible. A finite element simulation software “DEFORM 3D” is used to analyze the plastic deformation of the tube within the die cavity using the proposed movable die design. Forming windows for sound products using different feeding types are also investigated. Finally, tube hydroforming experiments of irregular bellows are conducted and experimental thickness distributions of the products are compared with the simulation results to validate the analytical modeling with the proposed movable die concept.

STOCHASTIC MODELING OF LIVING/CONTROLLED COPOLYMERIZATIONS IN TUBULAR REACTORS WITH LATERAL FEED

It is known the controlled microstructure polymers production increase in continuous reactors due to all industrial advantages that this type of operation presents. In this paper, the synthesis via Nitroxide-Mediated Polymerization (NMP) of copolymers based on styrene and methyl methacrylate accomplished in a tubular reactor with lateral feed is modeled by Kinect Monte Carlo (kMC). This reactional configuration aims the copolymers production with originals microstructure and applications. There were obtained all the microstructural properties distributions of the synthesized material at interest and the conversion values, Polydispersity Index (PDI) and chains average molar mass are compared to experimental data. The conversion presented minimum and maximum deviation in the module of 0.61 and -21.85%, respectively. For the PDI and the molar mass, there were obtained minimum and maximum errors of 0.72%, 1.50%, -23.10% and 1.77%, respectively. It was verified that the formed product differed from the expected one in experiments. There were found copolymers of polystyrene-b-poly(methyl styrene-rand-methacrylate), not being found any region that presented composition gradient through the chains, differently than it had been foreseen in the experimental synthesis, results that show the relevance of a stochastic simulation in the process to make decisions in the context of polymer reaction engineering.

Development of a TAPE-Agar Liquid Gel Bandage

In this study, a liquid gel bandage for wound treatment was synthesized using a combination of tannic acid and polyethylene glycol (TAPE). Agar was added as a stabilizer based on the physical properties of the formed product. Ethanol was chosen as solvent based on the resulting drying rate and mixing consistency. The liquid bandage was characterized in terms of its drying, adhesion, and swelling. Also, its antimicrobial and cytotoxic properties were evaluated. The final formulation had a drying time of 5 minutes, a T-peel adhesion yield point of 591.6 Pa, and a swelling ratio of 64%. The gel was also observed to be anti-microbial towards both S. aureus and E. coli, as well as exhibiting cytotoxic effects. Overall, the gel proved to have comparable properties to previously studied liquid bandages yet can be produced at a significantly lower cost.

Quantifying and Qualifying Alloys Based on Level of Homogenization: A U-10Mo Alloy Case Study

Homogenization heat treatment is performed to attain uniformity in microstructure which is helpful to achieve the desired workability and microstructure in final products and, eventually, to gain predictive and consistent performance. Fabrication of low-enriched uranium alloys with 10 wt% molybdenum (U-10Mo) fuel plates involves multiple thermomechanical processing steps. It is well known that the molybdenum homogeneity in the final formed product affects the performance in the nuclear reactor. To ensure uniform homogenization, a statistical method is proposed to quantify and characterize the molybdenum concentration variation in U-10Mo fuel plates by analyzing the molybdenum concentration measurement data from scanning electron microscopy energy dispersive spectroscopy line-scan. Statistical tolerance intervals (TI) are employed to determine the qualification of the U-10Mo fuel plate. We formulate an argument for the minimum number of independent samples to define fuel plate qualification if no molybdenum measurement data are available in advance and demonstrate that the given TI requirements can be equivalently reduced to a sample variance criterion in this application. The outcome of the statistical analysis can be used to optimize casting design and eventually increase productivity and reduce fabrication costs. The statistical strategy developed in this paper can be implemented for other applications especially in the field of material manufacturing to assess qualification requirements and monitor and improve the process design.

Synthesis, Structural Confirmation, and Biosynthesis of 22-OH-PD1n-3 DPA

PD1n-3 DPA belongs to the protectin family of specialized pro-resolving lipid mediators. The protectins are endogenously formed mediators that display potent anti-inflammatory properties and pro-resolving bioactivities and have attracted interest in drug discovery. However, few studies have been reported of the secondary metabolism of the protectins. To investigate the metabolic formation of the putative C22 mono-hydroxylated product, coined 22-OH-PD1n-3 DPA, a stereoselective synthesis was performed. LC/MS-MS data of synthetic 22-OH-PD1n-3 DPA matched the data for the biosynthetic formed product. Cellular studies revealed that 22-OH-PD1n-3 DPA is formed from n-3 docosapentaenoic acid in human serum, and we confirmed that 22-OH-PD1n-3 DPA is a secondary metabolite produced by ω-oxidation of PD1n-3 DPA in human neutrophils and in human monocytes. The results reported are of interest for enabling future structure–activity relationship studies and provide useful molecular insight of the metabolism of the protectin class of specialized pro-resolving mediators.

Mandrel-Free Hot-Spinning of 17-4 PH Truncated Cone

Forming experiments were carried out using 17-4 PH plates with 490 mm dia. × 5 mm thick and 7 mm thick. A truncated cone with 30 degrees wall angle was formed at 600 °C and 850 °C by using mandrel-free hot-spinning. The material properties and shape accuracy of the formed product were investigated with as-formed products and products subjected to a solution and aging treatment. It was found that the mandrel-free hot-spinning is able to form 17-4 PH plate into truncated cone. From the viewpoint of the forming accuracy and material properties of formed product, mandrel-free hot-spinning can be applied to 17-4 PH plate by forming at a temperature above 850 °C followed by an appropriate solution and aging treatment. In addition, it was confirmed that the deformation behavior of the formed product shows the same tendency as the deformation behavior of the Ti-6Al-4V alloy plate.