Reduced graphene oxide/ZnO composite : reusable adsorbent for pollutant management

Reduced graphene oxide (RGO) coated with ZnO nanoparticles (NPs) was synthesized by a self-assembly and in situ photoreduction method, and then their application for removing organic pollutant from water was investigated. The RGO@ZnO composite nanomaterial has unique structural features including well-dispersed NPs on the surface and dense NPs loading. This composite exhibited a greatly improved Rhodamine B (RhB) adsorption capacity and an improved photocatalytic activity for degrading RhB compared to neat ZnO NPs. These properties made RGO@ZnO reusable for pollutant adsorbent. The composite showed an excellent cycling performance for organic pollutant removal up to 99% recovery over several cycles via simulated sunlight irradiation.

Boron nitride nanosheets as improved and reusable substrates for gold nanoparticles enabled surface enhanced Raman spectroscopy.

Atomically thin boron nitride (BN) nanosheets have been found to be excellent substrates for noble metal particles enabled surface enhanced Raman spectroscopy (SERS), thanks to their good adsorption of aromatic molecules, high thermal stability and weak Raman scattering. Faceted gold (Au) nanoparticles have been synthesized on BN nanosheets using a simple but controllable and reproducible sputtering and annealing method. The size and density of the Au particles can be controlled by sputtering time, current and annealing temperature etc. Under the same sputtering and annealing conditions, the Au particles on BN of different thicknesses show various sizes because the surface diffusion coefficients of Au depend on the thickness of BN. Intriguingly, decorated with similar morphology and distribution of Au particles, BN nanosheets exhibit better Raman enhancements than silicon substrates as well as bulk BN crystals. Additionally, BN nanosheets show no noticeable SERS signal and hence cause no interference to the Raman signal of the analyte. The Au/BN substrates can be reused by heating in air to remove the adsorbed analyte without loss of SERS enhancement.

Photoredox catalysis of intramolecular cyclizations with a reusable silica-bound ruthenium complex

Photoredox catalysis with the use of a stable, reusable silica-bound chromophore was applied to the intramolecular cyclization of a series of 2-benzylidenehydrazinecarbothioamides to give 5-phenyl-1,3,4-thiadiazol-2-amines. The catalyst was readily prepared by carbodiimide-mediated coupling of commercially available amine-functionalized silica beads to a carboxylic acid functionalized ruthenium complex. The immobilized catalyst was readily removed from the reaction product by filtration and was used eight times without loss of catalytic activity. This simple, safe, and practical method is an attractive alternative to conventional procedures.

Generating reusable visual notations using model transformation

Visual notations are a key aspect of visual languages. They provide a direct mapping between the intended information and set of graphical symbols. Visual notations are most often implemented using the low level syntax of programming languages which is time consuming, error prone, difficult to maintain and hardly human-centric. In this paper we describe an alternative approach to generating visual notations using by-example model transformations. In our new approach, a semantic mapping between model and view is implemented using model transformations. The notations resulting from this approach can be reused by mapping varieties of input data to their model and can be composed into different visualizations. Our approach is implemented in the CONVErT framework and has been applied to many visualization examples. Three case studies for visualizing statistical charts, visualization of traffic data, and reuse of a Minard's map visualization's components, are presented in this paper. A detailed user study of our approach for reusing notations and generating visualizations has been provided. 80% of the participants in this user study agreed that the novel approach to visualization was easy and 87% stated that they quickly learned to use the tool support.

Generating reusable visual notations using model transformation

Visual notations are a key aspect of visual languages. They provide a direct mapping between the intended information and set of graphical symbols. Visual notations are most often implemented using the low level syntax of programming languages which is time consuming, error prone, difficult to maintain and hardly human-centric. In this paper we describe an alternative approach to generating visual notations using byexample model transformations. In our new approach, a semantic mapping between model and view is implemented using model transformations. The notations resulting from this approach can be reused by mapping varieties of input data to their model and can be composed into different visualisations. Our approach is implemented in the CONVErT framework and has been applied to many visualisation examples. Two case studies for visualising statistical charts and visualisation of traffic data are presented in this paper. A detailed user study of our approach for reusing notations and generating visualisations has been provided that shows good reusability and general acceptance of the novel approach.

Mechanism of a green graphene oxide reduction with reusable potassium carbonate

 A green method for the deoxygenation of graphene oxide (GO) was developed using K2CO3 as a reusable reduction agent. The size and thickness of the reduced GO are less than 1 μm and around 0.85 nm, respectively. Carbon dioxide is the only byproduct during this process. The reduction mechanism of the graphene oxide includes two reduction steps. On the one hand, ionic oxygen generated from the electrochemical reaction between hydroxyl ions and oxygen in the presence of K2CO3 reacts with carbonyl groups attached to the GO layers at 50°C. On the other hand, ionic oxygen attacks hydroxyl and epoxide groups, which become carbonyl groups and then are converted to carbon dioxide by K2CO3 at 90°C. These oxygenous groups are finally converted to CO2 from graphene layers, leading to the formation of graphene sheets. Headspace solid-phase microextraction and gas chromatography-mass spectrometry detected the existence of n-dodecanal and 4-ethylbenzoic acid cyclopentyl ester during the reduction, suggesting that oxygen functional groups on the GO layers are not only aligned, but randomly dispersed in some areas based on the proposed mechanism.

Analysis of stakeholder concerns with a view to avoid organisational conflict in B2B systems

In recent years there has been a remarkable increase in information exchange between organizations due to changes in market structures and new forms of business relationships. The increase in the volume of business-to-business (B2B) transactions has contributed significantly to the expanding need for electronic systems that could effectively support communication between collaborating organizations. Examples of such collaborating systems include those that offer various types of business-to-business services, e.g. electronic commerce, electronic procurement systems, electronic links between legacy systems, or outsourced systems providing data processing services via electronic media. Development and running of B2B electronic systems has not been problem free. One of the most intractable issues found in B2B systems is the prevalence of inter-organisational conflict reported to exist and persists between the participants of interorganisational electronic networks. There have been very few attempts, however, to prescribe any practical method of detecting the antecedents of such conflict early in B2B development to facilitate smooth construction and the subsequent operation of B2B services. The research reported in this paper focuses on the identification and analysis of antecedent conflict in a joint process involving different organizations in a B2B venture. The proposed method involves identification of domain stakeholders, capturing and packaging their views and concerns into a reusable form, and the application of captured domain experience in B2B systems development. The concepts and methods introduced in this paper have been illustrated with examples drawn from our study of six web-enabled payroll systems.

Sharing and reuse of web developers experience

Development of commercial web systems is laborious, lengthy and costly. This is partly due to the fact that the methods of their development can hardly cope with the complexity of provided services. Such services may need to be distributed and collaborative, require sophisticated software architecture, be rich in form, content and interactivity, and have a wide range of potentially casual users. While web development methodologies are slowly emerging from research methodologies, their adoption is far from wide-spread. To improve this situation, the authors propose an approach based on the observed practices of professional web developers, who openly share and reuse their web development experience, while guarding their development workproducts. To this end, we suggest to enhance web development methods, by collecting problem-solving experience of web developers, packaging it into a reusable form, and providing a navigable decision structure assisting developers in identifying proven expert solutions suitable for a given problem context.

Waste production simulation for building deconstruction projects

The recently erected concept of building deconstruction has significantly promoted building components and materials reuse and recycling where building is carefully dismantled into reusable parts. Current research and practices of building deconstruction mainly focus on issues of process before and during the deconstruction such as hazardous material detection, deconstruction design and deconstruction technology. The issues after the deconstruction project are rarely considered. Waste reuse and recycling are enabled through deconstruction yet not practically achieved, and especially the demands of waste building components and materials are hard to appear and match the actual waste production in a building deconstruction project. To deal with this awkward situation, the waste production needs to be conducted in a demand-oriented way. It needs to be thoughtfully planned and scheduled prior to the physical deconstruction as an essential portion of deconstruction project planning and scheduling. Furthermore, the relationship between waste production and structural characteristics of the building creates a serious consideration affecting a deconstruction plan. As a result, a waste production simulation will facilitate waste reuse and recycling in a deconstruction project. It serves as a crucial section of deconstruction planning and design. This research aims to describe the concept of waste production simulation and investigate various management and technical aspects of waste production simulation for building deconstruction projects.

Integrated optimization system for high pressure die casting processes

High pressure die casting (HPDC) is a versatile process for producing engineered metal parts by forcing molten metal under high pressure into reusable steel dies. However there are a large number of attributes involved which contribute to the complexity of the process. A novel integrated approach is developed to optimize the high pressure die casting processes. The die temperature profiles will be studied with infrared thermograph technology and the internal cooling system will be optimized to provide even cooling to the components and the die. The heat stored in the die and the components is studied with image processing. Based on the geometrical profile of the components, cooling channels can be redesigned to improve the cooling efficiency while the cooling time is reduced. This will not only significantly improve the quality of the castings but also improve the productivity of the process.

Development of an automated DNA purification module using a micro-fabricated pillar chip

We present a fully automated DNA purification module comprised of a micro-fabricated chip and sequential injection analysis system that is designed for use within autonomous instruments that continuously monitor the environment for the presence of biological threat agents. The chip has an elliptical flow channel containing a bed (3.5 × 3.5 mm) of silica-coated pillars with height, width and center-to-center spacing of 200, 15, and 30 µm, respectively, which provides a relatively large surface area (ca. 3 cm²) for DNA capture in the presence of chaotropic agents. We have characterized the effect of various fluidic parameters on extraction performance, including sample input volume, capture flow rate, and elution volume. The flow-through design made the pillar chip completely reusable; carryover was eliminated by flushing lines with sodium hypochlorite and deionized water between assays. A mass balance was conducted to determine the fate of input DNA not recovered in the eluent. The device was capable of purifying and recovering Bacillus anthracis genomic DNA (input masses from 0.32 to 320 pg) from spiked environmental aerosol samples, for subsequent analysis using polymerase chain reaction-based assays.

Application of hermeneutics to studying an experience mining process

In this paper we investigate an approach to eliciting practitioners’ problem-solving experience across an application domain. The approach is based on a well-known ‘pattern mining’ process which commonly results in a collection of sharable and reusable ‘design patterns’. While pattern mining has been recognised to work effectively in numerous domains, its main problem is the degree of technical proficiency that few domain practitioners are prepared to master. In our approach to pattern mining, patterns are induced indirectly from designers’ experience, as determined by analysing their past projects, the problems encountered and solutions applied in problem rectification. Through the cycles of hermeneutic revisions, the pattern mining process has been refined and ultimately its deficiencies addressed. The hermeneutic method used in the study has been clearly shown in the paper and illustrated with examples drawn from the multimedia domain. The resulting approach to experience elicitation provided opportunities for active participation of multimedia practitioners in capturing and sharing their design experience.

A SOA-driven business intelligence architecture

A business intelligence architecture comprises of different unique components to collect, transform, analyze and present the structured and unstructured raw data in simple formats to assist decision makers in making timely decisions. The introduction of service-oriented architecture (SOA) enables reusable services which are accessible over a network on demand. However, there is still a lack of academic literatures on the business intelligence architecture with service-oriented concept. Based upon various references on BI architectures from major vendors, a novel BI architecture that is built on service-oriented concept is presented and described in this paper. The proposed service-oriented architecture enables enterprises to deploy a more agile, flexible, cheaper, reusable, reliable and responsive BI applications in supporting decision making process.

Highly selective and sensitive DNA assay based on electrocatalytic oxidation of ferrocene bearing zinc(II)-cyclen complexes with diethylamine

A highly selective and sensitive electrochemical biosensor has been developed that detects DNA hybridization by employing the electrocatalytic activity of ferrocene (Fc) bearing cyclen complexes (cyclen = 1,4,7,10-tetraazacyclododecane, Fc[Zn(cyclen)H2O]2(ClO4)4 (R1), Fc(cyclen)2 (R2), Fc[Zn(cyclen)H2O](ClO4)2 (R3), and Fc(cyclen) (R4)). A sandwich-type approach, which involves hybridization of a target probe hybridized with the preimmobilized thiolated capture probe attached to a gold electrode, is employed to fabricate a DNA duplex layer. Electrochemical signals are generated by voltammetric interrogation of a Fc bearing Zn−cyclen complexes that selectively and quantitatively binds to the duplex layers through strong chelation between the cyclen complexes and particular nucleobases within the DNA sequence. Chelate formation between R1 or R3 and thymine bases leads to the perturbation of base-pair (A−T) stacking in the duplex structure, which greatly diminishes the yield of DNA-mediated charge transport and displays a marked selectivity to the presence of the target DNA sequence. Coupling the redox chemistry of the surface-bound Fc bearing Zn−cyclen complex and dimethylamine provides an electrocatalytic pathway that increases sensitivity of the assay and allows the 100 fM target DNA sequence to be detected. Excellent selectivity against even single-base sequence mismatches is achieved, and the DNA sensor is stable and reusable.