Understanding hydrotropism: A chemical engineering perspective

The mechanism of root hydrotropism has been a mystery for many years, due to the complexity of the interactions between the external environment and plants themselves. To gain an engineering perspective, the time‐dependent hydrotropism of a single root has been modeled, initially using a two‐dimensional model. Based on the water and nutrient distribution in rhizosphere as computed with the conservation equations, together with a basic reaction‐kinetics‐type growth model and an intuitive root bending model, it has been found that the root already possesses the property of hydrotropism. For the first time, hydrotropism could be tracked by a process engineering model, which is a new idea based on chemical engineering concept, suggesting an alternative mechanism of hydrotropism. The effects of different initial root widths, lengths, and other growth/transport coefficients on root hydrotropism have then been explored. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1331–1346, 2016     

Advancements in droplet reactor systems represent new opportunities in chemical reactor engineering: A perspective

Traditional chemical reactors, such as batch reactors, continuous reactors, and semi-batch reactors, have been extensively studied and frequently act as central components of modern chemical plants. Recently, various advances in reaction times, surface-to-volume ratios, required amounts of reagents, and throughput have led to new directions in the design of miniaturized chemical reactors. In this Perspective, we provide an overview of the progress from traditional to miniaturized chemical reactors by summarizing the characteristics and applications of different types of reactors. Furthermore, we compare classical chemical reactors and miniaturized droplet reactors to highlight advancements in the design of droplet reactor systems based on open functional surfaces. Finally, we provide an outlook on the research directions of miniaturized droplet reactors.     

Implementation of the Italian school-work alternating programme within chemical engineering activities

This paper shows the implementation and the results of the application of the problem-based learning methodology within the framework of the school-work alternating programme (SWAP) in Italian High Schools. This methodology was articulated through five specific projects aimed at different student profiles inside a research group of Chemical Engineering at the University of Genoa (Italy).The proposed activities were aligned with the expected learning outcomes where creativity and originality were highly encouraged in order to promote lateral thinking. All the tasks were carried out in groups to boost team engagement and collaborative learning and used technological tools in specific problem-solving contexts.Students demonstrated positive attitudes towards the used technological tools, the collaborative work and the applied methodology. The great majority of the students showed satisfaction with the ICT tools and considered them as useful for their future career. The results also pointed out that participation and motivation were highly appreciated which was actually the basis of a successful implementation of the methodology.As a result of the exchange, students were able to promote their social and intellectual skills outside their usual comfort zone. At the same time, it constituted a public engagement opportunity for University as well as an important promotion tool towards society. Overall, the activities satisfied the main objectives of SWAP in terms of development of transversal competences and promotion of new technological skills and, more importantly, constituted an informative appreciated link between classroom lessons and, in this case, their immediate future as university students.     

On the possibility of using embedded electrodes for the measurement of dielectric properties in organic coatings

The present paper discusses the electric field distribution when an electric field is applied between two sensing electrodes embedded in an organic coating applied on metallic substrate. The results show that current lines tend to short-circuit throughout the metallic substrate and hence the measured impedance tends to approach that of the volume located below the electrodes plus the interfacial impedance. The results obtained from the numerical model have been verified by experimental measurements on organic coatings.     

On the rectification of measurement errors for complex chemical plants: Steady state analysis

An algorithmic approach is developed in the present work, which allows: (i) the classification of the measured and unmeasured process variables, (ii) The estimation of the desired unmeasured variables (using available measurements) in a complex chemical plant and (iii) the rectification of the process measurements. The method is very general and unlike the previous works it can be used in conjunction with linear and nonlinear mass and heat balances.The size of the estimation problem has been reduced significantly. Different algorithms are presented which permit the solution of special practical problems, and stochastic tests are proposed to check the consistency of the process data and detect gross measurement errors.Several examples demonstrate the developed algorithms and indicate the usefulness of the proposed approach, in classifying and estimating the processing variables and adjusting the process data through the utilization of mass and heat balances.     

Reprint of: Education of chemical engineering in Spain: A global picture

The general framework of the Chemical Engineering studies in Spain includes the Bachelor's Degree (4 years), Master's Degree (the most common duration is 1.5 years) and Doctorate (3-4 years). In 2008, the Conference of Directors and Deans of Chemical Engineering (CODDIQ) was constituted with the main objective of promoting and improving the quality of Chemical Engineering studies in Spain. Currently, Faculties and Schools of 29 Spanish universities are members of CODDIQ. An analysis of the most characteristic indicators provides a representative radiography of the Chemical Engineering Studies in Spain, whose most outstanding data are: (i) 7,396 undergraduate students, 1,014 Master students and 556 PhD students, (ii) according to the gender profile of undergraduates and graduates, the percentage of women is similar to that of men, while for faculty staff, the percentage of women is 43% and 46% for Associate and Assistant Professor (respectively) and 23% for the category of Full Professor category; (iii) after completing the Bachelor studies, most of them continue their training in the MSc in Chemical Engineering, (iv) the employability after obtaining the Master's degree is very high (>75%), which in the case of PhDs is close to 100%. The studies of Chemical Engineering in Spain have a very direct relationship with society, especially in the chemical, environmental, biotechnological and energy fields. The companies that collaborate in the training of future professionals are distributed throughout the national territory, which allows a strong connection with the socioeconomic environment.     

Ozone Solubility in Aqueous Solutions of NaCl,Na2SO4, and K2SO4: Application of the Weisenberger-Schumpe Model for Description of Regularities and Calculation of the Ozone Molar Absorption Coefficient

The ozone solubility in aqueous solutions of salts, NaCl (up to 5 М) and Na₂SO₄ (up to 2 М) and their mixtures, was studied. The results are adequately described by the semi-empirical model proposed by Weisenberger and Schumpe for calculation of the solubilities of atmospheric gases in concentrated solutions of electrolytes. By comparing the data obtained experimentally and calculated in terms of the Weisenberger and Schumpe model, the ozone molar absorption coefficient was found to be ε = 2860 ± 200 M^?1 cm^?1 at 260 nm.     

Hydrogen evolution reaction on Ni-P alloys: The internal stress and the activities of electrodes

The hydrogen evolution reaction (HER) was studied on Ni-P electrodes prepared by electrodeposition at temperatures varying from 23 °C to 65 °C. The activities for the HER of the electrodes first decreased slowly with the increasing temperature of the Ni-P preparation. A sudden decrease in the HER activity occurred on the electrode prepared at 65 °C. Similar dependence was found for the variation of the amounts of absorbed hydrogen with the electrodeposition temperature of the Ni-P electrodes. The behavior of Ni-P electrodes prepared from Ni-P powders was quite different. (Ni-P powder was prepared by peeling off the Ni-P layer and by milling the leaves of the Ni-P alloy in a vibrating ball mill.) The Ni-P powder electrodes displayed little activity independently of the temperature of the Ni-P powder preparation. It was followed from the results that the high activity for the HER of the layer Ni-P electrodes prepared at T ≤ 53 °C was caused by the internal stress in the layer. The stress originated during the electrodeposition of the Ni-P layer by co-deposited and absorbed hydrogen.     

化学工业多尺度融合的智能制造模式——互联化工

化工过程通过物质和能量的可控转化和传递来实现化工产品制备,具有多相性、非线性、非平衡、多尺度和多时空域等特性,化工行业智能制造发展的关键是实现多尺度条件下的互联协同与过程高效。一方面,化工过程多尺度互联机制的认识和调控是化工过程系统的安全可靠运行的关键;另一方面,实现化工过程多尺度下的互联、融合与协同是化工产业绿色发展的路径。鉴于此,本文提出了化学工业面向多尺度融合的智能制造模式——互联化工,给出了“互联化工”的概念、目标、特点和架构,并讨论了互联化工的相关关键技术,包括化学工业多层级的信息物理系统、云制造,以及全生命周期的安全管理技术、耦合互锁机制下的动态安全监控与决策模型、基于区块链的互联化工数据安全技术。     

A review of the contributions of P. Raj Bishnoi to chemical engineering

This paper provides a review of Professor Bishnoi's research contributions in the broad discipline of chemical engineering. Prof. Bishnoi has been a dedicated mentor, collaborator, innovator, and outstanding researcher. He has had a most productive and illustrious career, spanning more than four decades in both academia and industry. He is among the top 50 most-published authors of the The Canadian Journal of Chemical Engineering. He initiated a most successful and renowned research group at the University of Calgary, which was dedicated to the understanding of thermodynamics and kinetics related to the formation and decomposition of gas hydrates as well as the chemical engineering process design and simulation. As a tribute to Prof. Bishnoi's numerous scientific and engineering contributions and innovations, this review highlights his academic and research accomplishments, which included the training of several doctoral degree students, master's degree students, and postdoctoral scholars and research associates. In this paper, we have divided Prof. Bishnoi's research contributions into three broad areas, namely, chemical thermodynamics of hydrocarbon systems, process development and simulation, and thermodynamics and kinetics of the formation and decomposition of gas hydrates.     

Evaluation of the biomass fractionation capability of the ultrafiltration permeate: A learning project for chemical engineering students

This paper presents a 6-month integrated learning project, suitable for chemical engineering students in their last academic course (4 years bachelor). Within the Department of Chemical and Environmental Engineering at the University of the Basque Country (UPV-EHU), the performance of the project was established offering to the students the possibility of developing practical aspects studies in order to introduce them to the engineering profession. The general goals of the project have been to develop basic competences, such as the capability of finding and synthesizing the available information, the active participation in a team work, the improvement of the communications (oral and written) skill, the time management, the problem identification, strategy raising, the autonomy, in summary, to improve the students’ performance in multitask problem solving using a team work approach. The proposed educational objectives were achieved. The participant students were positive when asked whether, overall, the development of this project was “worth the effort” indicating as the most important benefit the developing of considerable indepth understanding and expertise in their work field.     

化学工程在低碳发展转型中的关键作用探讨——从物质资源利用与碳排放关联的视角

当前物质资源利用模式迫切需要向低碳发展转型。化学工程的科研人员及流程工业领域的利益相关者,有必要以资源利用模式的系统视角,重新审视物质资源利用与碳排放的复杂关系。基于本研究团队近年来对资源效率模式及低碳转型的研究成果,结合国内外相关研究进展,针对化学工程与低碳转型发展的关系进行深入分析,总结提出三个主要观点：（1）低碳转型中提升资源效率与碳减排存在正向协同,即物质资源利用与碳排放存在强关联,需要提升资源效率促进低碳发展转型;（2）低碳转型中碳减排和物质资源利用存在反向协同,低碳转型将拉动大量物质资源需求,需要通过技术创新和发展循环经济来对冲;（3）气候目标下化石资源利用模式将发生深刻变革,化石资源将更多地发挥“材料属性”而不是“能源属性”;“可持续的能源”和“可持续的碳源”将成为低碳流程工业的未来发展方向。化学工程作为研究物质资源转化的核心学科,将在人类向低碳社会过渡中发挥重要的和不可替代的作用。     

风险管理视角下的化工企业内部控制浅析

随着市场经济的不断进步和发展,我国的企业也面对着更加广阔的市场,参与了更广泛的竞争,化工企业也不例外。全球化背景下,在提高企业竞争力的同时,加强企业的风险管理,提高企业的内部控制水平,促进企业的健康有序发展十分必要。     

On the modeling of phase and chemical equilibria by equations of state for systems containing supercritical components and ionic species

A technique of modeling of phase and chemical equilibria by equations of state for systems containing supercritical components and ionic species is considered. Attention is focused on the structure of equation of states with inclusion of non-electrolyte and electrostatic contributions. A hole quasichemical model was applied to illustrate the technique and to show how an EOS can be modified for systems with chemical reactions and electrostatic interactions in the liquid phase. The concentration dependency of the density and dielectric permittivity was taken into account in describing the electrostatic contribution that is required for thermodynamic consistency of the results of modeling. A method of assessing the appropriate relationships for mixtures containing supercritical components is suggested, alongside with the way to estimate the “true” composition of mixtures where ionic species are formed due to chemical reactions. The raised questions are discussed with respect to the following systems: solutions of acid gases in water-alkanolamine mixtures and water-ammonia-carbon dioxide system in a broad interval of temperatures and pressures.     

Student Peer Assessment: A research study in a level III core course of the bachelor chemical engineering program

A study of anonymous student peer marking in a level III (third year) core course of the bachelor chemical engineering has shown that there was no significant difference (p > 0.05) in the average marks awarded by student assessors who had idealized solutions of the lecturer compared with those who did not; although more students with solutions (84%) completed the peer task than those without (69%). Students in a cohort of 64 (21 females, 43 males) were randomly assigned as a student-pair and tasked to mark each other's solutions to three numeric-type problems out of a possible 50, but only one student had idealized solutions. In 49 valid responses, 27 with and 22 without solutions, the maximum mark awarded by any assessor was 49 and the maximum awarded by the tutor was 50. The overall mean grade over the three problems was 14.3 for those with solutions and 14.5 without. The overall mean grade of the experienced tutor was 14.6. Despite this agreement in mean marking there were notable differences between student assessors and tutor marks in particular cases. The problems required stage calculations with reflux and column efficiencies; each had the marks indicated to be awarded for all sub-sections. Granularity in grades for both student assessors and tutor was a 1/2. There was no evidence of student collusion in marking. Independent survey results showed more than 3/4 of all student assessors highly valued this learning experience and that it stimulated interest in the course material. Students without solutions however were marginally less likely to want to have peer assessment in other courses (p = 0.095).     

A preliminary study on the effectiveness of inquiry-based activities for addressing misconceptions of undergraduate engineering students

This paper presents results from a preliminary study of the effectiveness of using inquiry-based activities to address misconceptions held by undergraduate engineering students in heat transfer and thermodynamics. These targeted misconception areas were identified previously as both important and difficult for students to master by a panel of engineering educators. Five separate inquiry-based activities (two physical experiments and three computer simulations) were developed and tested for their effectiveness at producing conceptual change during a 4-year study. Students’ conceptual change was assessed with concept inventories used in a pre-test–post-test design. The research examined students’ ability to answer conceptual questions both directly coupled with the developed activity and questions that required students to apply the targeted concept in new contexts. These assessments were done both immediately after the activity and 10 weeks later. Students’ performance generally improved in all areas, suggesting that the activities were effective for promoting conceptual change.     

Cooperative WebLab in chemical engineering between France and Brazil: Validation of the methodology

A WebLab is an experiment operated remotely via Internet. Besides the strictly technical aspects of such an experiment, which may contribute to the learning of Chemical Engineering fundamentals, there is also important feedback when teams of students of two different countries are working together: the WebLab becomes an intercultural experience, enhancing the communication skills of the students. A WebLab between Universidade Federal de São Carlos (DEQ/UFSCar) and the Ecole Nationale Supérieure d’Ingénieurs en Arts Chimiques et Technologiques (ENSIACET) is presented in this work. A mass transfer experiment in a bench scale reactor (stirred and aerated) had to be studied by mixed teams, thus emulating challenges that will be common in future working environments. In order to perform the experiment, students in Brazil and in France were put into groups. The students had to make decisions about the procedure for executing the experiments. All the students were able to control the equipment, no matter where they were physically. Students communicated using video conference software. The students’ and teachers’ opinions of this experience were very positive. This methodology is an important contribution to the education of engineers in a world integrated by modern communication technologies.