The determination of element speciation in environmentally important materials is often critical for understanding (i) the threat to human health posed by a specific element, and (ii) the means to minimize the environmental impact of an element during processing or in waste disposal after processing. In this overview, the use of X-ray Absorption Fine Structure (XAFS) spectroscopy is described for speciation determinations of specific elements in complex solid materials of importance to various environmental and energy issues, viz. coal combustion byproducts (ash), carbon-based sorbents for mercury capture from combustion flue gases, and airborne fine particulate matter (PM). Among the topics discussed are: the occurrence of hexavalent chromium and other potentially hazardous elemental oxidation states in coal combustion ash ; the role of chlorine, sulfur, etc., in the sorption of mercury from flue gases on carbon-based sorbents; and the occurrence of various elements such as sulfur, chromium, arsenic, halogens, etc., in National Institute of Standards and Technology (NIST) Urban and Diesel particulate matter standard reference materials, SRM 1648 and SRM 1650, respectively.

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The desirable characteristics of activated carbons for gas-storage applica tions are: (1) high microporosity (pores smaller than 2 nm) ; and (2) high sorbent packing density, i.e., low voidage in the storage container (e.g., the use of mono lithic sorbent elements). A cyclic chemisorption-desorption char activation tech nique was used to maximize micropore formation and minimize mesoporosity. Several carbons were prepared at different degrees of burn-off, and the BET surface areas were found to be up to 2000 m²/g. The carbons were prepared in the form of powders and pellets to demonstrate that the future use of shaped mono lithic elements can lead to the reduction of voidage in the storage container by up to 40%. The adsorption isotherms of the produced carbons showed high microporosity and no appreciable mesoporosity, even at high burn-offs. The advantage of using the cyclic chemisorption-desorption char activation technique over the traditional steady-state gasification was experimentally demonstrated. The paper also discusses the evolution of sorbent microporosity as a function of carbon burn-off and the duration of the chemisorption step. Preliminary data on hydrogen-storage capacity are also reported.

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Briquettes for heating or cooking are often made by pressing a blend of various chars. Desirable briquette properties include ease of ignition, minimal odors, high heat and long burning time. Lignite char contributes high heat and long burning but is often mixed with wood char to improve the ease of ignition. A thermogravimetric procedure was developed to measure the ignition proper ties of various lignite and wood char samples. Chars were collected at several points in the charring process or produced in the laboratory. Charring temper ature, time and length of aging of the char in air were important factors in the final char ignition properties. Char ignition temperature correlated well with the hydrogen content of the char.

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Catalytic hydrogenation of naphthalene and dibenzothiophene through a water gas shift reaction (CO+H₂→CO₂+H₂) in supercritical water (SCW) is studied. Experiments were conducted with NiMo/Al₂O₃ at 673 K and 30-32 MPa, in various atmospheres (H₂-SCW, CO-SCW, CO₂-H₂-SCW etc.), by using a tube bomb reactor. The results show that higher conversion of naphthalene was obtained in CO-SCW and in CO₂-H₂-SCW than in H₂-SCW. These results cleary indicate that the water-gas shift reaction in SCW produces species which have higher hydrogenationg reactivity than H₂ gas in SCW. Partial oxidation of hexylbenzene and n-hexadecane in SCW were also studied. At low water density (0-0.16g/cm³), CO₂ Was the main product. However, with increasing water density (up to 0.52g/cm³), the CO₂ ratio tended to decrease while the CO and H₂ ratios increased.

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Fog/cloud and rain water was collected at the mountainside of Hachiman tai range and rain water was also collected at Akita City. The various ion concentrations (H⁺, Cl^-, SO₄^2-, NO^3-, Na⁺, NH₄⁺, K⁺, Ca²⁺, Mg²⁺) of these sam ples were analyzed, and the droplet size and the wind direction were measured for each fog sample. The fog at Hachimantai range had a very high total ion concentration, and was considerably acidified by nss (non sea-salt)-SO₄^2- and NO₃^-, in comparison with the rain at Akita and Onuma (Hachimantai range). There were some fog and rain samples whose chemical components in insoluble substance, which were analyzed by PIXE analysis, were similar to that of Kosa from China. As the fog droplet size increased, the ion concentration decreased, and the slope of plots of the concentration versus the droplet size was different from each other. From the negative slope of the plots, we can conclude that the fog samples in this work were in the size interval I (unactivated or freshly-activated) for the droplet growth.

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The extraction yield of coal in N-methyl-2-pyrrolidinone (NMP)-CS₂ mixed solvents was greatly increased from 60% to 85% by adding a small amount of tetracyanoethylene (TCNE). The mechanism of TCNE interaction with coal to increase the coal extraction yield in solvent was investigated based on the spectrum properties of TCNE in NMP. It was found that TCNE does not exist as a neutral molecule in extraction solvent. Instead, TCNE forms 1, 1, 2, 3, 3-pentacyanopropenide anion in NMP. The 1, 1, 2, 3, 3-pentacyanopropenide anion might be responsible for the coal solubility increase.

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In order to investigate thermoplasticity of coals during heating, heat-treated coals were extracted with carbon disulfide-N-methyl-2-pyrrolidinone (CS₂-NMP) mixed solvent at room temperature. The highest extraction yields obtained for each coal heat-treated from 390-430°C had a linear relationship with its maximum fluidity measured by Gieseler plastometry. The amount of pyridine insoluble components of CS₂-NMP mixed solvent extract was also proportional to Gieseler maximum fluidity, suggesting that coal fluidity is affected by the presence of the heavier components. Dynamic viscoelastic measurement using a rheometer was applied to coal during heating. Elastic (G') and viscous (G'') moduli, and tan δ in which δ is a phase delay of a stress to a strain applied to a coal pellet were determined at 300-550°C. The temperatures corresponding to softening, maximum fluidity state, and resolidification of coals could be estimated from a maximum or minimum of G' and G'' observed at G' or G''- temperature profiles, and they are in fair agreement with those measured by Gieseler plastometry for the coals used. Tan a also gave a maximum near maximum fluidity temperatures estimated from G' and G''.

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Desulfurization behavior was followed in rapid pyrolysis of coals with the use of free-fall reactor under a nitrogen stream at a terminal temperature of 1253 K. The extent of organic sulfur removal from solid phase ranging from 33% to 90% did not correlate well with carbon content and aromatic carbon fraction of parent coals. XANES analysis for density-separated samples indicated that lower density group had higher content of organic sulfur including thermally decomposable sulfide. Thermally stable thiophenic sulfur was observed in the higher density group as a major form of organic sulfur. A good correlation was obtained between the extent of organic sulfur removal and aromatic carbon fraction for the density separated samples.

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The principle and analysis of sulfur K-edge X-ray absorption near edge structure (XANES) spectroscopy for structure determination of organic sulfur species in coals are reviewed. A third derivative method of the sulfur K-edge XANES spectra is compared with a least-squares method using the same Argonne Premium Coal Samples. The sulfur forms in raw, thermal treated and desulfurized coals by several treatment (bioprocessing, chemical treatment, and rapid pyrolysis) are determined. The applicability and usefulness of high-resolution sulfur XANES spectroscopy is demonstrated for direct, nondestructive and quantitative determination of the nature of organic sulfur in coal.

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The effects of vibrating grinding and calcination on the structure and reactivity of Kalabsha kaolinite have been studied by means of XRD, IR, DTA and BET surface area. Leaching experiments on ground and calcinated samples were carried out using 20% HC1 for aluminum extraction.
In the earliest stages of grinding the partial destructive of stacking kaolinite layers is occurred. These changes are associated with increase in surface area due to formation of fine grains with great number of boundaries. Further grinding or calcination lead to a deterioration of kaolinite structure. A Signif icant increase of surface area is observed, starting from 18m²/g for original sample to reach maximum value 42m²/g at 120 min. grinding time and 30m²/g at 300°C for calcination.
The extraction of aluminum after 30 min. leaching time is about 97.52% for the ground kaolinite at 240 min. grinding time and about 93.47% for calci nated kaolinite at about 550°C.

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Unidirectional solidification experiments of hypoeutectic, eutectic and hypereutectic high chromium white cast irons were conducted to clarify their deformation behavior at elevated temperatures. The relation between the microstructure and the high temperature strength was studied at temperatures reaching up to 1073K. The volume fraction of the precipitated carbide in theiron strongly depends on its chemical composition. The eutectic iron shows the highest strength within the whole temperature range. The eutectic iron shows approximately the same hardness and higher compressive strength compared with the hypereutectic iron in spite of a much a smaller carbide volume fraction than that of hypereutectic iron. The hypoeutectic iron shows a large amount of plastic deformation, while the eutectic and hypereutectic irons show very little plastic strain during deformation due to the presence of more brit tle carbides. The rule of mixtures holds for the hypoeutectic and eutectic irons but does not hold for the hypereutectic iron.

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Nickel (II) hydroxide intercalated montmorillonite containing different nickel content were oxidized with sodium hypochlorite. The structural change as well as change in electrical property has been occurred during oxidation. In this reaction, nickel (II) hydroxide layers were converted into conducting nickel oxyhydroxide layers. Two layered phases with different basal spacing were obtained. The first phase has a basal spacing of 1.25 nm, which appeared in the lower nickel content region below three nickel atoms per O₂₀(OH)₄ aluminosilicate unit. This phase showed an apparent dielectric character. The second phase has an expanded basal spacing of 1.96 nm in the higher nickel content region. In this region, the composites showed an apparent electric conductivity in the order from 10^-7 to 10^-3 Scm^-1, depending on the nickel content. These results suggested that insulator/conductor nano layered composites were synthesized through oxidation reaction. The temperature dependence of the electrical conductivity showed the semicomductive behavior.

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The musical instrument manufacturing industry uses an unusual variety of special materials to create products with the particular qualities sought by performers and their audiences. Whether the instruments appear to be as simple as drums, or as obviously complex as an electronic organ, the materials specified for their manufacture are usually the result of years of research, testing and development. Often, highly-specific materials are critical for the quality performance and marketability of a particular instrument.
There are several facets to the problem of producing high-quality guitars, relatively complex instruments to manufacture and market within a range of tolerable costs: Obtaining special or exotic woods, plating metal components, painting and lacquering, and manufacturing a large range of string choices. All of these activities provide problems related to the environment, materials availability and selection, engineering and artistic design, and manufacturing that are in the domain of metallurgical and materials engineers.
To provide some depth to this paper, however, the writer focuses on creative efforts to assure the present and longer-term availability of special and exotic woods from environmentally-sensitive regions. In particular, reasons are out lined why special or exotic woods are critical materials for making guitars, and the functions of the successful SmartWood^CM program are outlined as important practical ways to help provide and maintain their supply.

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