In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction had reached the equilibrium, and was subsequently fed to the test rig equipped with a single zeolite membrane purchased from Pervatech B.V. Results show a significant conversion increase as a result of water removal by pervaporation. Compared to distillation no addition of organics is necessary to efficiently remove water above the azeotrope. Nevertheless, some limitations and issues which call for optimisation are pointed out. A simple numerical model is proposed to support design and sizing of the pervaporation system. Various modes of integrated system operation are also briefly discussed.
Scientists around the world agree that nowadays, science is facing severe challenges like poor peer-review system, replicability crisis, or locked science behind paywalls. The National Science Center addresses at least some of them by introducing procedures that promote integrity, ethics, social responsibility, transparency, and openness in science.
The manufacture and consumption of market products show ever growing trends, and this means not only the supply and demand volume but also, to a higher and higher extent, searching for new products distinguishable from the variety of products on the market. Thus, it is necessary to find methods of functional, logical and structural combination of the so far existing engineering applications like CAx, RP/RT/RE, PDM/TDM, PPC/ERP, CE/SE and RDBMS techniques. A new challenge imposed on manufacturers by the competitive market is the so-called “product customization”, i.e. attending to an individual customer’s requirements in the features of a series manufactured product. The general objective of customisation is to elaborate features of a product, manufacturing processes, documentation and production organisation in such a way that the product’s individual features meet the customer’s requirements and its manufacturing process, price and service do not stray from series manufactured products.
Various trading strategies have been proposed that use estimates of the Hurst coefficient, which is an indicator of long-range dependence, for the calculation of buy and sell signals. This paper introduces frequency-domain tests for long-range dependence which do, in contrast to conventional procedures, not assume that the number of used periodogram ordinates grow with the length of the time series. These tests are applied to series of gold price returns and stock index returns in a rolling analysis. The results suggest that there is no long-range dependence, indicating that trading strategies based on fractal dynamics have no sound statistical basis.
Research focused on integration of machine operators with information ﬂow in manufacturing process according to Industry 4.0 requirements are presented in this paper. A special IT system connecting together machine operators, machine control, process and machine monitoring with companywide IT systems is developed. It is an answer on manufacture of airplane industry requirements. The main aim of the system presented in the article is full automation of information ﬂow between a management level represented by Integrated Management IT System and manufacturing process level. From the management level an information about particular orders are taken, back an on-line information about manufacturing process and manufactured parts are given. System allows automatic identiﬁcation of tasks for machine operator and particular currently machined part. Operator can verify information about process and tasks. System allows on-line analyzing process data. It is based on information from machining acquired: machine operator, process and machine monitoring systems and measurement devices handled by operator. Process data is integrated with related order as a history of particular manufactured part. System allows for measurement data analysis based on Statistical Process Control algorithm dedicated for short batches. It supports operator in process control. Measurement data are integrated with order data as a part of history of manufactured product. Finally a conception of Cyber-Physical Systems applying in integrated Shop Floor Control and Monitoring systems is presented and discussed.