Application of a multiline material characterization method to inkjet printed electronics

Material characterization has become increasingly important with the adoption of simulation‐based workflow for microwave electronics design. This article focuses on the characterization of printable electronics materials using transmission‐line measurements and demonstrates the capability of the multiline characterization method to separate dielectric and conductor losses when line geometry and material properties vary between the lines. The effects of multiline algorithm, number of line standards, and methods for selecting optimal line lengths are demonstrated. Consistent characterization results are obtained from inkjet‐printed transmission lines on two different substrate materials. In addition, local conductor thickness variations are demonstrated as an effective way to decrease losses. Finally, the simulation‐based procedure for determining the material properties is outlined and applied to printable electronics characterization. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:177–183, 2014.     

Compatibilization of PP/elastomer/microsilica composites with functionalized polyolefins: Effect on microstructure and mechanical properties

The morphology and mechanical properties of polypropylene/elastomer/silica composites were investigated with the aim of improving stiffness and impact resistance. Two different types of silica were tested: Precipitated silica and polymer grade microsilica (silica fume). The composites were compatibilized with commercial polypropylene and polyethylene containing maleic anhydride functionality as a means of controlling their microstructure and ultimately their mechanical properties. Comparisons were made with surface coated silica and hydroxyl-functionalized copolymers prepared with metallocene catalysts. The effect of adding the polymeric compatibilizers was assessed by morphology studies, thermal analysis and mechanical testing. Significant improvements in impact strength were obtained by tailoring the microstructure of polypropylene/elastomer/microsilica composites. With introduction of PP-g-MAH as compatibilizer, stiffness was enhanced simultaneously with impact strength. DSC curves of crystallization provided evidence to support the formation of different microstructures.     

Considering Prework on Industrial Projects

Prefabrication, preassembly, modularization, and off-site fabrication, collectively termed as prework have become more viable with recent advances in design and information technologies. These construction methods offer a substantial opportunity to improve project performance when circumstances merit. Successful implementation of these methods on a particular project requires systematic analysis and early decision making based on specific factors of the project. This paper identifies those factors influencing decisions on the use of prework, and current industry practices for evaluating the applicability of prework on industrial projects. It then presents a decision framework to assist industry practitioners with evaluating the applicability of prework on their project, and describes a computerized tool to aid project teams in the decision-making process. The developed framework and tool are useful and effective in the decision-making process, and easy to use, as validated by practitioners in the industry.     

Accessing Context in Wearable Computers

We present an easy interaction technique for accessing location-based contextual data shown on a head-worn wearable computer display. Our technique, called Context Compass, is based on a regular compass metaphor. Each object belonging to the user’s current context is visualised on a linear compass shown on the screen. The object directly in front of the user is shown in the middle of the compass and can be activated. Whenever the user turns his or her head, the objects on the screen move accordingly. Therefore, an object can be selected by simply turning one’s head towards it. Context Compass consumes a minimal amount of screen space, making it ideal for usage with see-through head-worn displays. An initial pilot study, applying a newly developed usability method customised especially for Context Compass, revealed that Context Compass can be learned virtually immediately. Further, the method itself proved to be successful in evaluating techniques such as Context Compass.     

Carbonation of calcium-containing mineral and industrial by-products

The use of carbon dioxide (CO₂) and calcium-containing by-products from industrial activities is receiving increasing interest as a route to valuable carbonate materials while reducing CO₂ emissions and saving natural resources. In this work, wet-chemical experimental data was assessed, which involved the carbonation of three types of materials in aqueous solutions, namely, 1) wollastonite, a calcium silicate mineral, 2) steelmaking slag, a by-product of steel production, and 3) paper bottom ash (PBA) from waste paper incineration. Aims were to achieve either a high carbonation degree and/or a pure carbonate product with potential commercial value. Producing a pure precipitated calcium carbonate (PCC) material that may find use in paper industry products puts strong requirements on purity and brightness. The parameters investigated were particle size, CO₂ pressure, temperature, solid/liquid ratio, and the use of additives that affect the solubilities of CO₂ and/or calcium carbonate. Temperatures and pressures were varied up to 180°C and 4 MPa. Data obtained with the wollastinite mineral allowed for a comparison between natural resources and the industrial by-product materials, the latter typically being more reactive. With respect to temperature and pressure trends reported by others were largely confirmed, with temperatures above 150°C introducing thermodynamic limitations depending on CO₂ pressure. The influence of additives showed some promise, although costs may make recycling and reuse of additives a necessity for a large-scale process. When using steelmaking slag, magnetic separation may remove some iron-containing material from the process (although this is far from perfect), while the addition of bicarbonate supported the removal of phosphorous, aside from improving calcium extraction. The experiments with paper bottom ash (PBA) gave new data, showing that its reactivity resembles that of steelmaking slag, while its composition results in relatively pure carbonate product. Also, with PBA no additives were needed to achieve this.     

Polymeric organogel as an effective approach for eradication of heavy metal ions As,Pb, Cd,and Cr from the surface of groundwater through adsorption stratagem

Excess metal pollutant has affected and caused serious havoc in the lives of terrestrial as well as aquatic beings. The core of this work revolves around eradicating highly toxic heavy metal ions from underground water systems using a cost-effective, high removal efficiency polymeric adsorbent capable of adsorbing and removing ionic metals whose backbone is composed of a bio-degradable polymer, polyvinyl alcohol. The obtained adsorbent was characterized using FT-IR, HNMR, and P-XRD. Morphological studies were carried out using SEM. Detection and adsorption of metal ions were performed using SEM–EDX and AAS; wherein the adsorbent was found to remove nearly 80% of arsenic ions, 70.5% and 70.7% for lead and chromium ions while 60.7% for cadmium ions, respectively. Further, the kinetics of adsorption along with intraparticle diffusion studies were also performed to determine the mechanism alongside observing the isothermal influence of the sorbent. The adsorption capacity was seen to be highest in arsenic at around 570.42 mg g⁻¹ thus acting as a potential and effective adsorbent for the removal of heavy metal ions from groundwater.     

T–T–T behaviour of bioactive glasses 1–98 and 13–93

In this work crystallization kinetics of bioactive glasses 1–98 and 13–93 are discussed. Within a certain temperature–time window these glasses can be hot worked into various products without interfering with crystallization. The crystallization was studied isothermally by heating glass plates at different temperatures for different times. Phases in the samples were studied through XRD and SEM analyses. The nucleation-like curves and crystallization characteristics were measured with DTA. The temperature of maximum nucleation was measured for glass 1–98 at 725 °C and for 13–93 at 700 °C. The activation energy of crystallization of both glasses was 280 kJ/mol. The Johnson–Mehl–Avrami exponent and the SEM micrographs of the samples suggested surface crystallization. The primary crystalline phase was wollastonite. The growth rate of the crystallized surface layer was 1 order of magnitude higher in the plates of 1–98 than in 13–93. The results can be utilized to optimize the parameters in hot-working of the glasses.     

Safety and immunogenicity of a combined diphtheria-tetanus-acellular pertussis-inactivated polio vaccine-Haemophilus influenzae type b vaccine administered at 2-4-6-13 or 3-5-12 months of age

METHODS: In an open randomized study we compared the safety and immunogenicity of two schedules for priming and booster vaccinations of infants. A pentavalent combination vaccine, including a lyophilized Haemophilus influenzae type b-tetanus toxoid conjugate vaccine reconstituted with a liquid diphtheria, tetanus, acellular pertussis (pertussis toxoid and filamentous hemagglutinin) and inactivated polio vaccine (DTaP-IPV/Act-HIB; Pasteur Mérieux Connaught, Lyon, France) was administered to 236 Swedish infants either at 2, 4 and 6 months or at 3 and 5 months, and a booster dose was administered 7 months after the last primary dose. Adverse events were monitored by diaries for 3 days after each vaccination and by questions at the ensuing visits. Antibodies against the different vaccine components were analyzed after the primary series of vaccinations, before and after the booster injections. RESULTS: There were no serious adverse reactions, and the rates of febrile events and local reactions were low in both groups. The three dose primary schedule induced higher geometricmean concentrations for all antigens than did the two dose schedule, but there were no differences between the groups in proportions with protective antibody titers against diphtheria, tetanus, Hib and polio or in proportions with certain defined levels of pertussis antibodies. Prebooster results showed a similar pattern, with the exception that the group primed with three injections showed higher proportions of infants with detectable antibodies against polio-virus types 1 and 3. After booster vaccinations there were no differences between the two schedules in geometric mean or in proportions with antibodies above defined antibody concentrations, indicating effective priming from both primary series of vaccinations. Conclusion. The combined vaccine DTaP-IPV/ Act-HIB vaccine was equally safe and immunogenic when administered according to both time schedules studied.