COBOL to Java and Newspapers Still Get Delivered

This paper is an experience report on migrating an American newspaper company's business-critical IBM mainframe application to Linux servers by automatically translating the application's source code from COBOL to Java and converting the mainframe data store from VSAM KSDS files to an Oracle relational database. The mainframe application had supported daily home delivery of the newspaper since 1979. It was in need of modernization in order to increase interoperability and enable future convergence with newer enterprise systems as well as to reduce operating costs. Testing the modernized application proved to be the most vexing area of work. This paper explains the process that was employed to test functional equivalence between the legacy and modernized applications, the main testing challenges, and lessons learned after having operated and maintained the modernized application in production over the last eight months. The goal of delivering a functionally equivalent system was achieved, but problems remained to be solved related to new feature development, business domain knowledge transfer, and recruiting new software engineers to work on the modernized application.Comment: 4 pages, Accepted to be Published in: Proceedings of the 2018 IEEE International Conference on Software Maintenance and Evolution (ICSME), September 23-29, 2018, Madrid, Spai

Acyclic directed graphs based on residue curves for feasability analysis

Residue curve maps (RCMs) provide a rapid and graphical way to visualize the feasibility of separation, taking into account the azeotropic constraints and boundaries. Unfortunately, due to its graphical nature, they are mainly used for azeotropic ternary systems. RCM represents the composition column profiles for distillation units operated at infinite reflux flow rate. When checking the feasibility, the present paper proposes to use acyclic directed graphs since the column profile of compositions are not so relevant compared to the singular points joined by them

Energy consumption in sharp and non-sharp splits of ideal ternary mixtures

Most of the distillation processes deal with multicomponent mixtures, existing a great quantity of distillation sequences for this process. The sharp splits available for an ideal ternary mixture are the direct and the inverse distillation sequence scheme in which the compounds are separated in two different columns. There are nonsharp splits in which all the compounds are separated in a single distillation column that can incorporate a side column. Unfortunately, to choose non-sharp splits schemes, there is no heuristic that can provide information about the recommended cases, e.g. a single distillation column in which the intermediate boiling compound is collected by a side stream at the required purity or by other possibilities, such as the use of a side stripper or a side rectifier. The literature about this subject is very scarce, and many times when the non-sharp splits are used, no comparison with the sharp split alternatives is provided. Therefore, the cases for which the literature suggests the use of side columns are further studied, e.g. BTX (Benzene, Toluene, Xylene) mixtures separation. For many case studies, the results obtained show that the energy savings achieved, due to the use of side columns, are not significantly higher than the best sharp split process schemes. However, these results do not discard that for some other situations; the side column could be the most advantageous case. Usually, it is considered that when the desired purity of the main product in a stream is reached, the impurities proportion do not affect significantly the energy consumption, and for most of the systems, this is true. However, for a mixture with a molar composition of 10 % isopentane, 10 % pentane and 80 % hexane (mol), when split in the respective compounds at a purity of 95 % (mol), very different energy requirements are depicted depending on the proportion of isopentane and hexane, present in the pentane stream obtained in a direct sequence process . The rigorous simulation results illustrate that almost 60% of the energy required to separate the abovementioned mixture is saved when the pentane stream carries a mixture of isopentane and hexane. In addition, the environmental impact has been analyzed for each case studied, being reduced in the same way as the energy consumption doe

Hydration of cyclohexene to cyclohexanol in a hybrid reactive distillation with a side decanter

Nowadays, more than 1 Mt of cyclohexanol is produced each year by the direct hydration of cyclohexene according to the patented Asahi process proposed in 1990. The Asahi process involves a reactor and a separation system to recover the reactants back to the reactor and collect the pure product. The non-reacted water is recovered in a decanter and the non-reacted cyclohexene in a distillation column. Nowadays, many processes have been successfully intensified, combining several unit operations into a single unit providing savings in units, piping and often also in energy due to the synergies generated. Examples of these synergies are: the continuous removal of products push forward the reaction to total conversion overcoming the chemical equilibrium limitations; the catalyst placed in the rectifying section of the column becomes protected from heavy compounds that could poison or deactivate the catalyst; the enthalpy of reaction is directly used in the separation; the boiling point of the mixture avoids hot spots that could damage the catalyst, etc. Although its advantages, it is not widely used in the industry and further study on intensification providing further successful examples are required. The present study shows by rigorous simulation with Aspen Plus V9.0 that the Asahi process is a good candidate to be intensified in a single unit. The rigorous simulation results show that cyclohexanol is collected with a molar fraction purity of 0.9999 at the bottoms of a hybrid reactive distillation column with 11 equilibrium stages operated at total reflux, i.e. total conversion of reactants. The water is fed at the top to stage 1 and the cyclohexene on stage 3, both in equimolar flow rate. The catalyst is only placed in these three stages at the column top. A side stream from stage 6 is fed to a side decanter, where the aqueous phase is recycled to the column top (stage 1) and the organic phase to the next bottom stage, i.e. stage 7. As in the Asahi process, a great excess of water is present to push the reaction equilibrium forward. Hence, the molar ratio of water recycled vs feed to the system is of 125. The reboiler duty is 197 kJ/mol of cyclohexene, and the condenser duty is 564 kJ/mol cyclohexene due to the exothermic reaction. Therefore, a novel intensified process scheme for cyclohexene hydration is proposed

A Heuristic for extractive agent flow rate in extractive distillation

Distillation is the most widely used separation process for liquids separation in the industry. Even when the volatilities of the mixture are not favorable, then enhanced distillation is used. Extractive distillation is the enhanced distillation most widely used that consists in introducing a large flow rate of a third compound called extractive agent with a high boiling point that it is collected at the column bottoms and recovered in another column and reused again. Some heuristics are available for distillation column design, e.g. the optimum reflux is around 1.2 to 1.35 times the minimum reflux (or 1.1-1.2 times for refrigerated systems). Unfortunately, there is not a similar heuristic to determine the optimum extractive agent flow rate. Based on a literature review of rigorous simulations of extractive distillation processes, a heuristic is proposed that indicates that the optimum extractive distillation flow rate is which provides a Distillation Sequence Efficiency at 78 % of its maximum value. The maximum value is calculated assuming infinite flow rate of extractive agent. The Distillation Sequence Efficiency is a shortcut method available for distillation columns sequencing

Surrogate model for carbon dioxide equilibrium absorption using aqueous monoethanolamine

A novel surrogate model useful for designing CO2 absorption columns is provided to describe the vapour-liquid equilibrium of CO2 in a flue gas or biogas and aqueous monoethanolamine (MEA). The surrogate model is adjusted with experimental data and compared with dedicated software for electrolyte mixtures, i.e. OLI®. The assessment of CO2 partial pressure is conducted at different MEA concentrations, temperatures and loading of CO2/ MEA in the liquid phase. The OLI® model is in good agreement with the experimental data when MEA concentration is between 15 to 30 % wt, as well as for high MEA concentrations (between 45 and 60 % wt) at 60 °C. However, for temperatures above 80 °C, the model is in agreement with experimental data only when the load of CO2 in the liquid phase exceeds the range from 0.25 to 0.30 (usual industrial operating range is from 0.2 to 0.4). A point not addressed in experimental data in literature is the presence of MEA in the vapour phase, which overcomes the recommended values from health safety point of view at 100 °C. The presence of MEA in biogas could produce NOx. The influence of inert gas (CH4) on the equilibrium is considered to check the model suitability for biogas enrichment. The novel surrogate model provides a good regression of all the experimental data in the operating region and it is validated using Pareto diagrams

Assessing Tourists’ Preferences for Recreational Trips in National and Natural Parks as a Premise for Long-Term Sustainable Management Plans

Sustainable tourism management plans rely on relevant and consistent information about factors that can influence the decision to visit a protected area. This paper uses the choice experiment method to investigate tourists’ preferences with regard to recreational trip characteristics in national and natural parks in Romania. An on-site survey questionnaire was administered to visitors. The multinomial logit model was employed to investigate the preference orderings of the identified groups of recreational users. Overall, results indicate that tourists gain benefits after visiting the parks. Main preference differences were found for information sources and location of campsites. Visitors who stated that the park was the main trip destination were willing to have access to more information sources, the marks on trails being insufficient. Camping is preferred only in organized places, expressing the concern for environmental protection. The results of this study have management implications, highlighting the importance of assessing tourists’ preferences as a foundation for developing sustainable tourism strategies

Immission assessment inside an industrial ventilated room using CFD

Nowadays the ventilation design of enclosed spaces is still based on the number of air renewals per hour. This coarse approach was developed in the past but nowadays is a fast and simple computational exercise to determine where and when the Threshold Limit Value (TLV) is surpassed. A rather superficial Computer Fluid Dynamics (CFD) analysis is able to provide insights that are useful to propose measures to keep the pollutants concentrations at safe levels. As illustrative example, the contaminants' level inside a factory is simulated, both in steady and unsteady state, for risk and health assessment to determine the contaminant levels reached as consequence of the normal operation or in case of a sudden release. The case study is based on an example related to the ventilation of a printing factory for which there are field measurements available in literature. Two pollutants are emitted separately; one continuously during operation and the other only sporadically during cleaning. A good agreement is obtained between the simulations and previous field measurements. This case is an example that a design fulfilling the legislation according to the air renewals tabulated can surpass the threshold limit value in practice. The main conclusion is that the legislation should be based on CFD results instead of general tabulated values, as in some cases the ventilation could be too oversized and in others may result insufficient

Electrical behavior of multi-walled carbon nanotube network embedded in amorphous silicon nitride

The electrical behavior of multi-walled carbon nanotube network embedded in amorphous silicon nitride is studied by measuring the voltage and temperature dependences of the current. The microstructure of the network is investigated by cross-sectional transmission electron microscopy. The multi-walled carbon nanotube network has an uniform spatial extension in the silicon nitride matrix. The current-voltage and resistance-temperature characteristics are both linear, proving the metallic behavior of the network. The I-V curves present oscillations that are further analyzed by computing the conductance-voltage characteristics. The conductance presents minima and maxima that appear at the same voltage for both bias polarities, at both 20 and 298 K, and that are not periodic. These oscillations are interpreted as due to percolation processes. The voltage percolation thresholds are identified with the conductance minima

TAME -a Quantum Mechanics Study of the Reaction Mechanism for Methoxylation of Isoamylenes

The present paper describes the quantum mechanics study regarding a tertiary-alkyl methyl ether synthesis mechanism. As octane number boosters, ethers such as TAME (2-methoxy-2-methylbutane) represent a solution for increasing the amount of oxygen in gasolines and for decreasing their isoamylenes content, for more environmentally-friendly fuels. The quantum mechanics modeling targeted the elucidation of the isoamylenes methoxylation mechanism, defining the transition states involved in the reaction of 2-methyl-2-butene (2M2B) with methanol, using benzenesulfonic acid to simulate cation-exchange resins catalytic involvement