Teaching engineering design: Can reading a textbook make a difference?

Teaching design is an integral part of most engineering curricula. Often, students are introduced to the engineering design process through a chapter in a textbook. Does this passive approach to teaching an active process aid the students' learning? An experiment was conducted to assess what students learn about the design process when they read a text. Here, 10 students enrolled in a freshman course were asked to read aloud from a freshmen engineering textbook. Half of the subjects read the text prior to solving three open-ended engineering design problems and the other half solved the same problems before they read the text. Both the subjects' process in solving the problems, as well as the quality of their solutions (the product), are assessed. Results show that subjects that read the text before they solved the three problems spent significantly more time solving the problems and were more sophisticated in their problem solving strategies. These subjects also scored better when judged on the quality of their approach to the problem (including the number of design criteria considered, communications, assumptions, and technical accuracy). However, these subjects did not score better on a quality measure of the final solution.     

Ethical motivations for green business and engineering

Corporate references to “sustainability” and the operative process of “green business” have become almost commonplace over the past decade. Companies not only seek to comply with environmental regulations, but many have discovered that techniques for reducing adverse environmental impact often have positive effects on corporate profitability as well. Such adoptions of green business and engineering practices are morally neutral because the driving forces behind them are legal and economic, but not ethical. In some instances, however, managers and engineers have undertaken green business initiatives with the notion of doing something positive for future humans and for the natural environment. In this paper we discuss the “green” driving forces behind moral decisions regarding the adoption of green engineering and business practices and conclude that most “green engineering” known to the public is simply good business practice. Only when engineering and business begin the “green engineering” program with the aim of reducing adverse impact on health or environment does “green engineering” become morally admirable.     

Agent-based features for CAD browsers to foster engineering collaboration over the Internet

For distributed engineers, CAD browsers are very good tools to collaborate asynchronously over the Internet. Support for synchronous collaboration is well researched and developed. However, for asynchronous collaboration systems, the research is very limited. The purpose of this study is to identify the major factors that affect the efficiency of engineering collaboration over the Internet using CAD browsers and design-agent-based features to support engineering collaboration. Activity coordination, collaboration awareness, and communication support were identified as the major factors for efficient engineering collaboration using CAD browsers. The agent-based features of Comment Status, Communication Agent, Team Member Information Enhancement, and Task Information Enhancement were designed to support communication, activity coordination, and collaboration awareness issues for engineering collaboration. A prototype of the CAD browser was designed. Three experiments were conducted to test the efficiency of the new proposed features in the agent system. The experimental results indicate that (a) the Comment Status feature reduced the missing rates of comments and comment processing time, (b) the Communication Agent reduced delay time in processing comments, and (c) the features of Team Member Information and Task Information Enhancement improved collaboration efficiency and subject satisfaction.     

Strategies for the chemical and biological functionalization of scaffolds for cardiac tissue engineering: a review

The development of biomaterials for cardiac tissue engineering (CTE) is challenging, primarily owing to the requirement of achieving a surface with favourable characteristics that enhances cell attachment and maturation. The biomaterial surface plays a crucial role as it forms the interface between the scaffold (or cardiac patch) and the cells. In the field of CTE, synthetic polymers (polyglycerol sebacate, polyethylene glycol, polyglycolic acid, poly-l-lactide, polyvinyl alcohol, polycaprolactone, polyurethanes and poly(N-isopropylacrylamide)) have been proven to exhibit suitable biodegradable and mechanical properties. Despite the fact that they show the required biocompatible behaviour, most synthetic polymers exhibit poor cell attachment capability. These synthetic polymers are mostly hydrophobic and lack cell recognition sites, limiting their application. Therefore, biofunctionalization of these biomaterials to enhance cell attachment and cell material interaction is being widely investigated. There are numerous approaches for functionalizing a material, which can be classified as mechanical, physical, chemical and biological. In this review, recent studies reported in the literature to functionalize scaffolds in the context of CTE, are discussed. Surface, morphological, chemical and biological modifications are introduced and the results of novel promising strategies and techniques are discussed.     

A bibliometric profile of top-scientists a case study in chemical engineering

We carefully selected a group of chemical engineering scientists internationally recognized as top-scientists in their field. A method has been developed to systematically compare bibliometric characteristics of these top-scientists with an average scientist in chemical engineering. This method also includes citation-analysis of books and proceedings. The results show a very clear bibliometric profile. First, top-scientists references are more numerous and, fourth, they concern more recent literature. Our fifth findings is that the journals used by top-scientists for their publications are representative for the field of chemical engineering as a whole. But they differ in specific aspects significantly from the average journal structure in chemical engineering: the published work of top-scientists is both general as well as more specialistic than the average work in chemical engineering.     

A methodology for screening of microalgae as a decision making tool for energy and green chemical process applications

The increasing interest for biotechnological use of microalgae demands a methodology for selection of species suitable to support the development of technologies based on the use of such non-conventional renewable raw material, i.e., green industrial applications. The vast and expanding collection of experimental data on both cell growth and biomass composition available in the literature can be used to reduce the cost of the experimental investigations required to support process engineering and optimization. Selecting the appropriate organism requires extracting useful information from such data, a cumbersome task since various multidisciplinary factors must be considered. This paper presents a computer-aided methodology for selecting appropriate algal species given an energy or green chemical process application employing microalgae as a renewable raw material. The approach is “system oriented”, based on biomass composition and chemical processing of the biomass downstream of the CO₂ biofixation and harvesting operations. Quantitative performance results are supported by professional process simulation. Besides comparison of a set of species performances, the proposed methodology also allows the discrimination among distinct algal compositions resulting from different growth conditions for a given species. Furthermore, three categories of screening metrics are proposed to be maximized by the decision making procedure in order to elicit the relevant information. To demonstrate the potential of the proposed methodology, a databank of both biochemical and elemental compositions of microalgal biomass was used in three green applications: Assessment of biomass heating value; production of syngas by gasification of the biomass; and production of Bio-H₂. Within the accuracy of the databank employed to illustrate the procedure, the methodology selected Botryococcus braunii and Isochrysis galbana as potential promising candidates, for the three examined applications.     

A review of US EPA and FDA requirements for electronic records, electronic signatures, and electronic submissions.

Both the United States Environmental Protection Agency (EPA) and the U.S. Food and Drug Administration (FDA) have issued regulatory documents that address the issues and requirements concerning electronic reporting to the Agencies. EPA has published two comprehensive and useful electronic data interchange (EDI) guidelines: 1) the EPA Electronic Data Interchange (EDI) Implementation Guideline, Draft of September 23, 1994 and October 18, 1994 that is available at the following EPA web site address: www.epa.gov/oppeedi1/guidelines/general.pdf and 2) the Interim Final Notice, Filing of Electronic Reports via Electronic Data Interchange, September 4, 1996, Federal Register Notice [FRL-5601-4, Volume 61, Number 172, page 46684], also available at: www.epa.gov/oppeedi1/edipoli.htm. The FDA has published a guidance document titled, "Guidance for Industry, Computerized Systems Used in Clinical Trials, April 1999" that is available at FDA's web site: www.fda.gov/ora/compliance_ref/bimo/ffinalcct.++ +htm. FDA's guidance document addresses a number of issues for electronic records that are applicable to all areas of GLP compliance. Another FDA document presently under development is titled, "Electronic Standards for the Transmission of Regulatory Information (ESTRI) Gateway." The ESTRI document defines strategic plans for electronic submissions to FDA. FDA has published a guidance document in this area titled, "Guidance for Industry: Providing Regulatory Submissions in Electronic Format--General Considerations, January 1999." This guidance document is available at: www.fda.gov/cder/guidance/index.htm. FDA has also published an important final rule applicable to all electronic records and signatures that is part of the U.S. Title 21 Code of Federal Regulations (CFR), Part 11, titled, "FDA's Final Rule, Electronic Records; Electronic Signatures, effective August 20, 1997." This FDA ruling is discussed below and is available at: www.fda.gov/cder/esig/index.htm.     

ATRP and ROMP: Modular chemical tools for advanced macromolecular engineering

Well-defined graft copolymers were synthesized through the combination of two highly controlled polymerizations, ATRP (Atom Transfer Radical Polymerization) and ROMP (Ring-Opening Metathesis Polymerization). Synthesis of α-cyclobutenyl polystyrene-b-poly(tert-butyl acrylate) macromonomers was first performed by ATRP from an original initiator. ROMP of these macromonomers using Grubb’s generation II catalyst ((IMesH₂)(Cy₃P)RuCl₂(CHPh)) has allowed to synthesize well-defined graft copolymers with a polybutadiene backbone and polystyrene-b-poly(tert-butylacrylate) grafts. α-Cyclobutenyl polystyrene-b-poly(acrylic acid) macromonomers were prepared by acidolysis. An amphiphilic water-soluble α-cyclobutenyl polystyrene-b-poly(acrylic acid) macromonomer has been successfully employed as stabilizer in emulsion polymerization of styrene.     

Sustainable GQDs for potential application in engineering using corn powder as green precursor

Abstract

An alternative way to produce Graphene Quantum Dots (GQDs) economically is proposed in this study where corn powder was used as a green precursor to fabricate GQDs in a hassle less one-step route. These GQDs showed a stable, size-dependent in aqueous solution. The size of GQDs obtained from this work is approximately measure from 0.21 to 5.20?nm. The XRD patterns showed a broad peak at 22?Å. Furthermore, the UV-vis absorption spectrum has a broad peak around the range of 250–350?nm which is ascribed to the typical absorption of n-π* transition of the carbonyl groups. The said sample also exhibited bright green photoluminescence under an UV light. The Raman spectra displayed a D band around 1375?cm^?1 and G band around 1578?cm^?1. The performed analysis confirms that the GQDs by this method has a similar result compared to the other methods. This suggests that corn powder as a precursor can be used to fabricate GQDs in a simplistic and environment-friendly way for potential application in sensors, very large scale integration and energy generation technology.     

Throughput/inventory dollar-days: TOC-based measures for supply chain collaboration

As the semiconductor industry moves away from vertical integration, performance measures play an increasingly important role to ensure effective collaboration. This paper demonstrates that the theory of constraints (TOC)-based measures, Throughput and Inventory Dollar-Days (T/IDD), induce autonomous supply chain (SC) links to function as a synergistic whole and thereby, improve the performance of the whole SC network significantly. We model an SC network of a well-known TOC case study using discrete event simulation and discuss managerial implications of these measures via a set of scenarios. The scenarios explain how these measures – without sharing sensitive financial data – allow members of an SC network to monitor both the effectiveness (TDD) and efficiency (IDD) of SC members and lead them to create win-win solutions following well-known TOC-based planning and control concepts. We conclude this paper by discussing some limitations of the proposed research and provide directions for future theoretical research.     

Of green monkeys and failed affordances: A case study of a mechanical engineering design course

This article reports on an ethnographic study of a mechanical engineering design class. The findings are based on participant observation of one student design team of three students as they designed, tested and built an engineered solution to a problem over a period of ten weeks. The paper describes the curricular efforts to provide social and material affordances both for learning and doing design, and the failure of students on the observed team to take up those affordances. It offers explanations for failure within a framework of conflicting classroom views and pedagogic issues. It discusses the implications of the observed student behavior for design education in general, and mechanical engineering design, in particular.     

Chitosan-collagen/organomontmorillonite scaffold for bone tissue engineering

A novel composite scaffold based on chitosan-collagen/organomontmo-rillonite (CS-COL/OMMT) was prepared to improve swelling ratio, biodegradation ratio, biomineralization and mechanical properties for use in tissue engineering applications. In order to expend the basal spacing, montmorillonite (MMT) was modified with sodium dodecyl sulfate (SDS) and was characterized by XRD, TGA and FTIR. The results indicated that the anionic surfactants entered into interlayer of MMT and the basal spacing of MMT was expanded to 3.85 nm. The prepared composite scaffolds were characterized by FTIR, XRD and SEM. The swelling ratio, biodegradation ratio and mechanical properties of composite scaffolds were also studied. The results demonstrated that the scaffold decreased swelling ratio, degradation ratio and improved mechanical and biomineralization properties because of OMMT.     

Electrospun chitosan/hydroxyapatite nanofibers for bone tissue engineering

Chitosan (CS) nanofibers were prepared by an electrospinning technique and then treated with simulated body fluid (SBF) to encourage hydroxyapatite (HA) formation on their surface. The CS/HA nanofibers were subjected to scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy, and X-ray diffraction (XRD) to confirm HA formation as well as determine the morphology of the nanofibrous scaffolds. The SEM image indicated that the distribution of HA on the CS nanofibers was homogeneous. The results from EDS and XRD indicated that HA was formed on the nanofibrous surfaces after 6-day incubation in the SBF. The calcium/phosphorus ratio of deposited HA was close to that of natural bone. To determine biocompatibility, the CS/HA scaffolds were applied to the culture of rat osteosarcoma cell lines (UMR-106). The cell densities on the CS/HA nanofibers were higher than those on the CS nanofibers, the CS/HA film, and the CS film, indicating that cell proliferation on CS/HA nanofibers was enhanced. Moreover, the early osteogenic differentiation on CS/HA was also more significant, due to the differences in chemical composition and the surface area of CS/HA nanofibers. The biocompatibility and the cell affinity were enhanced using the CS/HA nanofibers. This indicates that electrospun CS/HA scaffolds would be a potential material in bone tissue engineering.     

Heparinized hydroxyapatite/collagen three-dimensional scaffolds for tissue engineering

Currently, in bone tissue engineering research, the development of appropriate biomaterials for the regeneration of bony tissues is a major concern. Bone tissue is composed of a structural protein, collagen type I, on which calcium phosphate crystals are enclosed. For tissue engineering, one of the most applied strategies consists on the development and application of three dimensional porous scaffolds with similar composition to the bone. In this way, they can provide a physical support for cell attachment, proliferation, nutrient transport and new bone tissue infiltration. Hydroxyapatite is a calcium phosphate with a similar composition of bone and widely applied in several medical/dentistry fields. Therefore, in this study, hydroxyapatite three dimensional porous scaffolds were produced using the polymer replication method. Next, the porous scaffolds were homogeneously coated with a film of collagen type I by applying vacuum force. Yet, due to collagen degradability properties, it was necessary to perform an adequate crosslinking method. As a result, N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) was employed as an efficient and non-toxic crosslinking method in this research. The composites were characterized by means of SEM, DSC and TNBS. Furthermore, heparin was incorporated in order to accomplish sustained delivery of a growth factor of interest namely, bone morphogenetic proteins (BMP-2). BMP-2 binding and release of non-heparinized and heparinized scaffolds was evaluated at specific time points. The incorporation of heparin leads to a reduced initial burst phase when compared to the non heparinized materials. The results show a beneficial effect with the incorporation of heparin and its potential as a localized drug delivery system for the sustained release of growth factors.     

Low-temperature,chemical vapor deposition of thin-layer pyrolytic carbon coatings derived from camphor as a green precursor

Camphor, C₁₀H₁₆O, as a natural and renewable carbon precursor, can be pyrolyzed to pyrolytic carbon (PyC; pyrocarbon) with significant industrial applications from conducting electrodes to biomedical implant coatings. Here, a simple but controllable chemical vapor deposition setup, operating at low temperatures (650–800 °C) in nitrogen atmosphere at ambient pressure in the absence of catalyst, was used. According to XRD and Raman spectroscopy, nanocrystalline thin PyC films were obtained at this temperature range without a significant change in L _c and d ₀₀₂ values. When the deposition temperature increased from 700 to 800 °C, L _a and crystallinity percentage values were increased from 2.40 nm and 73.16% to 4.15 nm to 87.58%, respectively. SEM and AFM analyses showed smooth (Ra ≈ 1 nm) and shiny surface for the thin films with 10–500-nm range thickness. The films were hydrophilic on surface (water contact angle ≈ 72.45°) with surface free energy of ≈ 41 mN/m. Young’s modulus, hardness and friction coefficient of the thin PyC coatings were calculated using nanoindentation technique as ≈ 29.9, 3.5 GPa and 0.09, respectively. Resistivity of the films was 2.21 × 10^?5 Ωm, so it can be anticipated to repel the blood cells. Cytocompatibility screening in direct contact mode and in vitro biocompatibility findings supported cyto- and hemocompatible properties for the PyC specimens synthesized from camphor.     

Materials engineering for a better global environment

The role of materials engineering including ceramics technology for a better global environment is discussed. Present global environmental issues will be solved by resourceful energy technology and waste management under a minimum pollution of environment. The materials technology will play an important role to mitigate the global environmental issues. Research program on future energy technology and waste management should be considered according to a condition of domestic and/or international regulation. Energy saving and domestic waste management including pollution prevention of atmosphere, water and soil are near term research areas. Medium and long term research areas are non-fossil energy technology and global waste management including removal and/or reuse of greenhouse gas CO₂ and nuclear waste management. To mitigate future global environmental issues, traditional materials technology should be reconstructed to build environment benign materials technology which could provide minimum environmental load.     

Preparation and characterization of a novel COL/BC composite for potential tissue engineering scaffolds

This paper describes the biosynthesis of a novel collagen-bacterial cellulose (COL/BC) composite by adding collagen to the culture medium of Acetobacter xylinum. The morphology of COL/BC composite was observed by SEM and TEM and compared with pristine BC. The composite was further characterized by FTIR and XRD. It is found that the structure of BC network changes when collagen is present in the nutrient medium. Further work is underway to gain insights into the mechanisms governing the experimental phenomena.