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New papers that have been accepted for publication in the International Journal of Applied Ceramic Technology are posted to “Early View” on the Wiley website and can be read even before the issue is printed. Below are summaries of selected papers currently available via Early View.

All members of The American Ceramic Society receive free online access to ACT. To access any of the ACerS journals, or to become a member, visit www.ceramics.org.

	Joining of Sintered Silicon Carbide Ceramics Using Sodium Borosilicate Glass as the Solder Zhaohua Luo, Dongliang Jiang, Jingxian Zhang, Qingling Lin, Zhongming Chen and Zhengren Huang This team of researchers from the Shanghai Institute of Ceramics developed a sodium borosilicate glass powder (Si:B:Na molar ratio of 53:44:6) as a solder to join sintered SiC ceramics. The team reports that the coefficient of thermal expansion of the glass matches the SiC substrate well at low temperature and that the wettability of the solder on SiC substrate is excellent above 1150°C. The team also reports that good adhesion between the SiC substrate and solder layer was achieved. Image: Interface between the interlayer (right side) and SiC substrate (left side). Credit: ACT; Wiley.
	A Thermoanalytical Study of the Conversion of Amorphous Si-Ti-C-O Fibers to SiC Nathan S. Jacobson and Sara E. Kline Jacobson and Kline, NASA Glenn Research Center, studied the conversion of polytitanocarbosilane fibers to SiC from 1400°C to 1600°C using thermogravimetry, X-ray diffractometry and scanning electron microscopy. Their study suggests that a chemical reaction step is rate-limiting, there is conversion of an amorphous phase to crystalline SiC and there is development of internal porosity and large grains on the fiber surface. Image: Cross-section of LoxM fiber heat-treated at 1600 °C for 4h. The white dashed line delineates an inner core region with more porosity. Credit: ACT; Wiley.
	Tailoring the Relative Si3N4 and SiC Contents in Si3N4/SiC Nanopowders through Carbothermic Reduction and Nitridation of Silica Fume Jyothi Suri, Leon L. Shaw and Mahmoud F. Zawrah This team of researchers from the United States and Egypt reports that it has, for the first time, synthesized nanostructured Si3N4/SiC composite powders from waste silica fume using an integrated mechanical and thermal activation process. They conclude that the carbothermic reduction and nitridation temperature as well as the graphite concentration in the starting SiO2 + C mixture are the important parameters to obtain the nanopowders and control their crystal sizes (as small as 17 nanometers for SiC and 42 nanometers for Si3N4). Image: SEM images of graphite: (a) before and (b) after ball milling alone for 6 h. Credit: ACT; Wiley.
	Synthesis of Ceramic Bonded Carbon Using SiC-Coated Carbon Particles and Spark Plasma Sintering Masaharu Nakamura, Tetsuro Tojo, Makio Naito and Yoshinari Miyamoto These Japanese researchers used SiO powders and a chemical vapor reaction method to form a dense SiC coating on carbon particles by controlling atmosphere, temperature, time and SiO/C weight ratio. They used spark plasma sintering to sinter the SiC-coated carbon particles. They report that the product—called ceramic bonded carbon—can be easily joined to SiC ceramics using spark plasma sintering. Image: Photo of a SiC/CBC nut machined with an internal thread of 6 mm diameter and 0.75 mm pitch. Credit: ACT; Wiley.
	Effects and Control of Polymer-Converted Carbon Impurity in Synthesizing Continuous Boron Nitride Nanofibers by Electrospinning Yejun Qiu, Jie Yu, Jing Yin and Xiaosong Zhou This team of researchers from China reports that it introduced oxygen and ammonia gases simultaneously to effectively control and remove—by varying O2/NH3 ratio, temperature, time and gas flow rate—the carbon impurity that results from using a polymer as a thickener in the precursor solution method of preparing boron nitride nanofibers by electrospinning. Image: SEM images of as-spun B2O3/PVB (polyvinylbutyral) composite fibers prepared using different PVB concentrations. Credit: ACT; Wiley.
	Benefits of the LTCC Substrate Configuration with an Air-Gap for Realization of RF Inductor with High Q-Factor and SRF Goran J. Radosavljević, Andrea M. Marić, Walter Smetana and Ljiljana D. Živanov This research term from Austria and Serbia placed low-temperature cofired ceramic meander-type-structured inductors on various substrates with the placement of an air-gap beneath the inductor. The team reported that it achieved greater than 30-percent increase in quality factor and greater than 55-percent increase of operating frequency range width compared with inductors on standard substrate configurations. Image: (a) Measurement of set-up and calibration and (b) moment of measurement. Credit: ACT; Wiley.

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2010 impact factor and other metrics demonstrate long term value of ACerS publications.

Most participants in the scholarly publishing process take a keen interest in the journal impact factor, a yearly metric issued by Thomson Reuters. The 2010 IFs were just released and the news for ACerS journals is very good.

Of the three journals the American Ceramic Society publishes through its partner, Wiley—Journal of the American Ceramic Society, International Journal of Applied Ceramic Technology and International Journal of Applied Glass Science—JACerS and ACT are ranked in the top ten in the category Materials Science - Ceramics. The JACerS IF increased an impressive 11.5 percent over its 2009 value.

The JACerS IF is 2.167, the second highest for journals in the ceramic materials category. The ACT IF suffered some, dropping to 1.28 from its 2009 level of 1.627, but was still high enough to rank it in the top ten ceramics journals. IJAGS is too young to have an IF calculation. The Journal of the European Ceramic Society had the highest 2010 IF, experiencing an increase to 2.574 from its 2009 IF of 2.09.

What is the “impact factor?”

The IF is just one of the metrics used in the Journal Citation Reports that Thomson Reuters publishes yearly, and is probably its most visible metric. IF metrics were developed by the now-defunct Institute for Scientific Information, which has been absorbed into the Thomson Reuters organization.

In a general sense, the IF is a measure of the influence and relevance of a journal. The ISI formula¬¬-sometimes called the 2-year IF-is:

IF = Number of current year citations to the journal articles published in the two years prior/Number of articles published in the journal in the two years prior.

Therefore, the 2010 IF numerator is the number of citations (in any journal) during 2010 to articles published by the journal in 2008 and 2009. The denominator is the total number of articles published by the journal in 2008 and 2009. In 2010, JACerS articles from 2008-09 were cited 2815 times, and the number of articles published in 2008-09 was 1299, giving the IF of 2.167.

IF is a useful metric, but it is important not to overemphasize it.

JACerS senior journal editor, David Green said in an email communication, “Impact factor can be influenced by several extrinsic factors. For example, the rate of publication can influence IF. As an exaggeration, it would inflate the IF if all papers were published in January rather than spread through the year.” He also noted that papers published online before print can influence IF.

Also, because it is a ratio, it is informative to look at metrics other than just the IF. (An oceanographer might ask, which is more impactful: a tall, skinny wave or a squat, wide wave?)

The simplest of metrics is the number of citations per year. This number does not contribute to the IF because it covers all years and does not separate out the two-year-prior base of citations used in the IF calculation. But, it does give some “order of magnitude” perspective that can inform IF interpretations. For ceramic journals, JACerS is ranked first by a large margin, with over 29,000 citations in 2010. The closest competitor is the Journal of Non-Crystalline Solids (19, 500 cites; IF 1.483) followed by the J. Eur. Ceram. Soc. (12,600 cites).

Another metric is the “Immediacy Index,” which is the average number of times an article is cited in the year it is published. This year the J. Eur. Ceram. Soc. had the highest II of ceramics journals and JACerS the second highest. Similar to IF, it can be affected by extrinsic factors like the timing of publications, early online publication, etc.

While IF and II are indicators respectively of recent and very short term interest in a journal’s articles, the long term value of a journal’s articles is even more important.

There are two metrics that indicate the effectiveness of journal editors at selecting high quality articles: the “5-year IF” and the “Cited Half-life.” The 5-IF is the same as the 2-year IF but captures the relevance of a journal’s articles over the longer time span. It helps normalize the effects of things that can skew the importance of the literature, like trendy science and “funding flashes.” On this metric, JACerS ranks first with a 5-IF of 2.37, followed by J. Eur. Ceram. Soc. at 2.265.

Finally, the “Cited Half-life” measures the median age of articles cited in the current JCR year, that is, the long-term relevance of articles and the level of fundamental scholarship that the journal offers. In the field of ceramics, JACerS and Phys. Chem. Glasses-B lead with a CHL of over 10 years. Green says, “A large Cited Half-life shows the fundamental nature of JACerS articles, as they will be referred to for many years.”

ACT’s cited half-life is 4.3 years, impressive because 2010 was only its seventh year of publication.

Factors other than metrics should be considered by scientists when they are deciding where to submit papers, and Green recommends taking a broad view, “For example, they should consider whether the review process is fair, thorough and adds value to their papers.” He suggests authors ask themselves, “Was the submission process friendly? Are the published figures of high quality with the appropriate resolution? Is the text clear and understandable? Are the articles in the journal based on fundamental science that incorporates the Scientific Method? Are the articles published rapidly and do they describe new discoveries? Does the journal have a global reach?”

The Thomson Reuters website has in-depth information about IF and other metrics that go into the Journal Citation Reports.

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ACerS’ publishing partner Wiley is making a limited number of free article downloads from their comprehensive Online Library (each valued at $30) available to members on a monthly basis. Because the number of downloads is limited, ACerS is inviting each member to one free download per month while response to the new program is assessed. Articles may be downloaded from any Wiley content area.

To access articles, log into the ACerS website (ceramics.org), click on Knowledge Center > ACerS/Wiley Download Direct > Access the ACerS/Wiley Download Direct Program. Select a topic, search for an article, view the abstract to make sure it’s the right article, and click on the pdf or html link. Or click here to get started.

It’s yours for free!   

Clicking on the pdf or html link does constitute a download, so reviewing the abstract before download is recommended.

Remember, one article download per month, per member. If you need more than one article, contact Marcia Stout at mstout@ceramics.org to see if additional downloads are available.

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Houses in Thailand typically have steep roofs and may benefit from new, cooler ceramic tile pigment. Credit: Wikipedia.

A two-degree temperature drop in room temperature may not sound like a lot, but it can make a huge difference in a nation’s aggregate energy costs and investments. This is particularly true in a warm climate nation with many ceramic tile rooftops and a developing economy, such as Thailand. The (relatively) easy solution is to use a white TiO₂-based pigment, which has a high near-infrared reflectance (87%). The problem is that not everyone likes white roofs. White isn’t a huge problem for flat roof that can’t be seen, but getting widespread adoption of white tiles for pitched roofs visible from below can be a problem for aesthetic and cultural reasons.

But, as reported on in ACerS’ International Journal of Applied Ceramic Technology (doi:10.1111/j.1744-7402.2010.02599.x), there is now a green color alternative to white for roof tiles. A new paper in ACT discusses the discovery by a trio of Thai ceramic reseachers investigating “cool materials” (a generic term for building materials that make use of pigments that have high near-infrared solar reflectance or low NIR solar absorptance) of a green-hued, heat-blocking alternative to white-glazed tiles.

The group, working out of King Mongkut’s University of Technology and Suratthani Rajabhat University, started with a chromium oxide pigment base, which by itself has a medium-high NIR reflectance (50-57%). In Thailand, where steep, tinted roofs are preferred, Cr₂O₃ is of interest not only because of its reflectance but also ceramic glazes containing it can provide shades of green, which, tend to be dull and dark.

To see if some brighter colors and more reflective compositions are possible, the researchers added varying amounts of TiO₂, Al₂O₃ and V₂O₅ to the Cr₂O₃ and synthesized a test group of 39 different compositions. These compositions were then calcined and formed into test disks, whereupon their reflectance was measured using a UV–Vis–NIR spectrophotometer.

As it turned out, one particular sample — “S9″ — composed of (by weight percent) 80% Cr₂O₃, 4% TiO₂, 14% Al₂O₃ and 2% V₂O₅ stands out because it has a NIR solar reflectance of 82.8%, i.e., close to the reflectance of TiO₂.

To test the S9 sample under more realistic conditions, the group constructed two identical test “houses” built so that heat could only penetrate through the roof tops. One house was covered with 50 pieces of S9-glazed ceramic roof tile. For control purposes, the other house was roofed similarly, but with tiles glazed with a commercially available green pigment. Reflectance and temperature measurements were then recorded over a five-day summer period.

As expected, they found the NIR reflectance of S9-coated tiles was relatively high, 76.3%, compared to the control-coated tiles (65.7%).

In regard to the thermal tests, temperatures were taken at three locations within each house. They found that the house with the S9-coated tiles stayed cooler than the control house by about 2°C across the three measured positions.

The group’s work was supported by several institutions and governmental agencies, including the Energy Policy and Planning Office, Ministry of Energy; the Commission on Higher Education under the Strategic Scholarships for Frontier Research Networks for Thai Doctoral Degree Program; and National Research University.

By the way, for Oak Ridge National Lab’s Building Envelopes Program (a.k.a., “Roofs and Walls”) has many resources and calculators for researchers and consumers related to “developing technologies that improve energy efficiency and environmental compatibility of residential and commercial buildings.”

As a final note, it should be pointed out that while the benefits of cool roof technologies vary depending on geographic location among other things, they are not necessarily only of interest to nations and people living in topical or semitropical regions. While the addition of insulation may be more cost effective in many cooler climes, even New York City seems to have a fairly robust effort called NYC°CoolRoofs (and is part of the “100 Cool Cities Global Initiative”).

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Ann Arbor-based Adaptive Materials Inc, a specialist in making microtubular solid oxide fuel cells, announced yesterday that it has won $3 million in new funding through Michigan’s Centers of Energy Excellence Program.

AMI, until now, has focused most of its efforts on military uses for its SOFCs, such as soldier-worn units, power sources for unmanned vehicles and field uses. The company has both 50- and 250-watt SOFCs that can be fuel with off-the-shelf propane and butane canisters.

While AMI’s business plan has always mentioned applications in the recreational vehicles, boating and medical devices markets, the reality is that it has been easier for military customers to justify the relatively high costs of these portable power devices.

However, a press release from AMI notes that, “The company will use the funding to support the commercialization of its fuel cells within the consumer leisure market.”

AMI may be on to something. It has always struck me that there is some pretty strong logic behind developing small SOFC products whose form factor incorporates safe, cheap and easy to find fuel cartridges. Generations of campers, for example, have grown up using portable stoves and lamps that use these small gas canisters.

Michelle Crumm, AMI chief business officer, says, “Funding from COEE provides the extra boost we need to break into the consumer market and deliver a truly game-changing technology. . . By focusing our technology on readily-available fuels, Adaptive Materials solved a problem associated with fuel cells: Consumers could certainly find need for a fuel cell, but no fuel to actually sustain the unit.”

Presumably, AMI will use the funds to continue to drive down the production costs of making their SOFCs. The company uses a unique co-extrusion method to form its microtubular SOFCs. Earlier this year, in the pages of ACerS’ International Journal of Applied Ceramic Technology, the University of Birmingham’s (U.K.) Kevin Kendall praised recent developments in microtubular SOFC science and applications:

Significant progress is being made in the development of microtubular SOFCs. Since its invention in the early 1990s, information about its benefits has been disseminated, leading to the start-up of several companies interested in applications from laptop power supplies to combined heat and power to transport and APUs.

Plastic extrusion is the main method for producing microtubular cells. This is an economic process, which can lead to high-quality ceramics with good strength and Weibull modulus. Co-extrusion is also a promising possibility that could produce one-step processing of cells.

A key benefit of microtubular SOFC is the increased power density, inversely proportional to diameter. Power densities of 1 kW/L are possible but the number of cell connections rises with the square of power density and could become the limiting factor. Thermal shock resistance of microtubes is many orders of magnitude better than that of planar SOFCs. Ramp rates of 8000 K/min are possible.

Aaron Crumm, Adaptive Materials’ chief visionary officer and co-founder, along with John W. Halloran, published an excellent paper in ACerS’ Journal of the American Ceramic Society back in 1998 about innovative methods to micromanufacture complex ceramic–metal structures:

These structures are fabricated by multiple pass co-extrusion of a feedrod comprised of several powder-filled thermoplastic compounds. The compounds contain either ceramic, metal or fugitive powders. To illustrate the capabilities of microfabrication, a demonstration part containing lead manganese niobate-lead titanate ceramic and silver palladium was fabricated. The final part was microconfigured, with a fenestrated structure containing 3110 repeat units per square centimeter. The repeat unit feature sizes were 15 and 5 µm for the ceramic and electrode, respectively. Microfabrication by co-extrusion is proposed as a fabrication technique for the production of smart structures and materials.

Illustration from Crumm and Halloran paper. Credit: JACerS

The COEE program, administered by the Michigan Economic Development Corp., supports the development, growth and sustainability of alternative energy sectors throughout the state. The COEE program focuses on where the state has competitive advantages in areas of the workforce, intellectual property and natural resources but where funding is required to overcome technical and supply-chain hurdles that could prevent or stall the commercialization process.

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