Industrial research departments and chemical engineering institutes have begun to adopt additive manufacturing technologies, such as stereolithography for producing special types of reactors for ...continuous production. Microreactors have been widely used to improve the mass and heat transfer processes between immiscible liquid-liquid phases, but with the disadvantage of requiring sophisticated technology for their manufacture. In this paper, an approach for producing millireactors by stereolithography and rapid optimization of millireactor design with circular cross-section is presented.
Transesterification of vegetable oils with alcohols is widely used method for biodiesel synthesis, generally taking place in a batch reactor. Microreactors due to their short residence times and high biodiesel yields are currently being explored for continuous production, but have disadvantages in low production volumes and high pressure drops. To overcome above-mentioned problems, millireactors with channel diameters from 1.5 mm to 3.5 mm were produced in order to investigate the impact of channel dimensions on conversion of sunflower oil to fatty acid methyl esters (FAME). Transesterification reaction of sunflower oil using methanol with addition of KOH base catalyst to FAME was monitored by Fourier-transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance.
Results show that millireactors with smaller channel dimensions and processes with higher temperatures at certain residence times can be used to achieve better biodiesel yield in much shorter time than batch reactors. In addition, continuous way of FAME production in millireactors is presented. Production in millireactors provided an improvement when compared to microreactors because they have low pressure drops and higher production volumes.
•Enhanced recovery and CO2 retention are studied in a high CO2 content gas reservoir•Later EGR start results in higher CO2 retention•Optimal CO2 injection duration during CO2-Enhanced Gas Recovery is ...around one year•Depending on the chosen timing for CO2 injection, EGR can be carbon-negative
Benefits of CO2 injection into a gas-condensate reservoir were examined based on a real-field data. The observed natural gas reservoir has high content of CO2, therefore it is desirable to inject the produced CO2 back to the reservoir in order to reduce the emissions at the natural gas processing plant and possibly increase hydrocarbon production. Simulation was made as to compare hydrocarbons production with and without CO2 injection. Since the CO2 source is the reservoir itself, CO2 injection is limited by the produced gas quantities. Investments in low-risk projects on already producing natural gas fields can be feasible compared to investments in completely new and high-risk/high-gain projects, as the highest storability, and additional recovery of hydrocarbon part of the gas is achieved near the end of production. As in late production periods the process can be carbon-negative, i.e., more CO2 is injected than produced, such an enhanced gas recovery scheme can be considered as an advantageous preliminary step before converting the reservoir to CO2 storage facility.
Background
Patients with hematological diseases are polytransfused and often immunocompromised, therefore susceptible to transfusion reactions (TR). This study aims to document the incidence of TRs ...in adult hematological patients and assess the effect of changes in the production of blood components and transfusion practice on their occurrence.
Study design and methods
Retrospective observational analysis of TRs reported from 1993 to 2019 was performed. For the analysis of the effect of changes on the incidence of TRs, the evaluated time was divided into two periods: the 1st period before the introduction of changes in production, when leukoreduced blood components were used only selectively, and the 2nd period, when semi‐automated method of production and universal leukoreduction was introduced.
Results
The decrease in the incidence of TRs was observed for both red blood cell (RBC) and platelet concentrate (PC) transfusions in the 2nd period. Since platelet additive solution has been used, a further decrease in the incidence was reported. The decrease in incidence was also observed for delayed hemolytic/serological transfusion reactions and for transfusion‐transmitted bacterial infections. Four cases of incorrect blood transfusions were uniquely related to the hematological patients, caused by antigen loss and transfusion ordering after ABO‐incompatible hematopoietic stem cell transplantation.
Discussion
Our results provided evidence that the introduction of tools offered by modern transfusion medicine: universal leukodepletion, plasma replacement with additive solutions, sensitive laboratory techniques, prophylactic antigen matching policy, informatization, and automatization, decreased the incidence of TRs and improved transfusion safety.
The paper discusses the presentation of real estate in the balance sheet, its valuation, posting, write-off from business books in accordance with International Accounting Standards. Tangible assets, ...consisting of property, plant, equipment and various types of inventories, represent the most significant property category among all users of public revenues. According to international accounting standards, it should be presented in the balance sheet according to the value that is based on market prices of the same or similar property. Therefore, the property is periodically revalued and at the end of each accounting period it is checked whether the carrying amount deviates from the amount that would be received by the sale. Property, plant and equipment are the most significant part of total state assets and are differentiated in the balance sheet from other items at high values.
Aditivnom proizvodnjom moguće je izraditi proizvode složene geometrije koje konvencionalnim tehnikama poput tokarenja i glodanja nije moguće izraditi. Primjenom proizvodnje rastaljenim filamentom – ...FFF (engl. Fused Filament Fabrication) i stereolitografije – SLA (engl. Stereolithography) moguće je izraditi složene unutarnje strukture, tankostijene dijelove (milikanale) kao i dijelove unutar dijelova (pregrade).
Cilj ovoga rada bio je ispitati mogućnosti 3D ispisa na uređajima Zortrax M200 (FFF) i Formlabs Form 2 (SLA) u svrhu izrade funkcionalnih milireaktora s unutarnjim pregradama.
Kako bi se istražio utjecaj dimenzija milikanala na reakciju, ali i demonstrirala funkcionalnost cijelog sustava, u milireaktorima s pregradama je provedena sinteza FAME-a (engl. Fatty Acid Methyl Esters) transesterifikacijom suncokretovog ulja pomoću metanola uz dodatak baznog katalizatora KOH.
Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna .
The subject of this paper is an analysis of sports insurance options in the Republic of Serbia. Given the importance of sport in modern society, which manifests itself through its educational effects ...and the great capital it brings, the principle of freedom to play sports is at its peak. Injuries and illnesses of athletes are becoming more and more frequent as they face increasing demands and challenges. It is obvious that every year, day by day, more and more demands are placed on athletes and the exposure to injuries is increasing. The primary purpose of sports insurance is to provide economic protection to insured individuals (athletes, coaches, referees) and legal entities (sports organizations, federations, clubs) from the negative consequences of injury to athletes and the loss of income that athletes earn, but also their clubs in the case of a club competition, which occurs when the risk is realized, that is, the insured event occurs.
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