Wednesday, April 29, 2009

materials sciences, Metallurgy and Metallography

Total Results: 14105
Mechanical Behaviour of an Aluminium Alloy With Fusible Grain Boundaries
92
Authors: B. Baudelet; M. C. Dang; F. Bordeaux; INSTITUT NATIONAL POLYTECHNIQUE DE GRENOBLE (FRANCE)

7000 SERIES Al alloy was shown to have a liquid grain boundary, the extent and distribution of which depended on the thermal history of the material. If T was less than 477 C (melting temperature of the boundary), the solid material displayed classical mechanical behavior. At T greater than 477 C, it was observed that the liquid grain boundary influenced the mechanical behavior of the alloy. At higher strain rates ...
Creep Fracture Mechanisms in Single Crystal Superalloys
92
Authors: S. H. Ai; V. Lupinc; M. Maldini; ACADEMIA SINICA SHENYANG (CHINA) INST OF METAL RESEARCH

Using constant load creep tests, the creep fracture mechanisms of single crystal superalloys CMSX-2, SRR 99 and RR 2000 were studied. Crystals having orientations within 12 degrees of were tested in air between 750- 1000 C. It was shown that creep cracks always initiated at carbides in alloys containing a higher carbon level and at casting pores. Crack propagation occurred anisotropically along the crystallographic planes perpendicular to the applied load ...
High Temperature Tensile Deformation of a Nitrided Fe-1%V Alloy
92
Authors: A. Sakir Bor; MIDDLE EAST TECHNICAL UNIV ANKARA (TURKEY) DEPT OF METALLURGICAL ENGINEERING

A nominally pure Fe-1V alloy with less than 0.01% total impurities, and with homogeneously distributed vanadium nitride precipitates which had been formed by gas nitriding, was used to determine the relations governing the hot tensile deformation behavior. The true stress-strain at various temperatures from 673 to 1073K and strain rates 10-2 to 10-4/s for the alloys are reported. Temperature and strain rate dependence of the strength coefficient, K, obeyed an ...
Superplastic Behavior at High Strain Rates of a Mechanically Alloyed Al- Mg-Li Alloy
92
Authors: K. Higashi; T. Okada; T. Mukai; S. Tanimura; OSAKA PREFECTURE UNIV SAKAI (JAPAN) DEPT OF MECHANICAL ENGINEERING

The possible mechanisms of high strain rate superplasticity were analyzed by studying the tensile behavior of thin rolled sheet specimens of mechanically alloyed IN905XL with ultrafine grained structure (400nm in mean size) at various strain rates and temperatures. Strain rate sensitivity increased from 0.3 to 0.5 with increasing temperature.

articles

Atomic Absorption Spectrophotometer AAS –21

[PDF] Atomic Absorption Spectrophotometer AAS –21 - [ Terjemahkan laman ini ]
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FEATURES:
Innovated rich oxygen air-acetylene flame analysis technique:
The patented flame analysis technique adopting rich oxygen air-acetylene flame as the substitution for nitrous oxide-acetylene flame for high temperature element analyses, such as Ca, Al, Ba, W, Mo, Ti, V, etc. Flame temperature is continuously adjustable between 2300-2950 with makes it possible to choose the best atomization temperature for different elements. It features easy operation, low analysis cost and wide flame AAS analytical range. Rich oxygen flame will not pollute the environment and is not harmful to human bodies. It's break-through in flame AAS analysis Integrated flame/graphite furnace atomization system, changeable with flame emission burner;
• Automatically controlled changeover of the integrated flame and graphite furnace atomizer
featuring easy operation and time saving eliminates human labor
• A flame emission burner head can be installed to perform flame emission analysis to akali
metais as K, Na etc.
Accurate fully automated control system
• Automatic 6-lamp turret, automatic adjustment of lamp current and optimization of light beam
position
• Automatic wavelength scanning and peak picking
• Automatic spectral bandwidth changing
• Automatic changeover between flame and graphite furnace operation, automatic optimization
of position parameters, automatic ignition and automatic gas flow setting

Saturday, April 18, 2009

Baseline geochemical data for stream sediment and surface water

[PDF] Baseline analytical data for stream sediment and surface water ... - [ Terjemahkan laman ini ]
Jenis Berkas: PDF/Adobe Acrobat - Versi HTMLspectrophotometry following the method of O'Leary and Meier (1996). ... Co, Cr, Cu, Fe, Ga, Ge, La, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Pd, Pt, Sb, Sc, Sn, Sr, Th, Ti, V, W,. Y, Zn, and Zr. This method is designated ES in Table 2 and in the data ... This is particularly true for the major elements Al, Ca, Fe, K, Mg, ...

INTRODUCTION
During a 3-week period in the summer of 1996, the U.S. Geological Survey conducted a reconnaissance baseline geochemical study in central Idaho. Areas covered include Panther Creek, the Middle Fork of the Salmon River from Boundary Creek to the mouth, and the Main
Salmon River from North Fork to Corn Creek (Fig. 1). Stream sediment samples were collected
at all sample sites. Filtered and unfiltered stream water samples were collected at most sample
sites. The purpose of the baseline study was to establish a “geochemical snapshot” of the area,
as a datum for monitoring future change in the geochemical landscape, whether natural or human-induced. Events that could change the geochemical landscape include, but are not limited to, mining, flood, landslide, wildfire, or resource extraction activities. In the summer of 2000, there were numerous large wildfires in central Idaho. In particular, the Clear Creek (206,000 acres; 83,370 hectares), Little Pistol (74,000 acres; 29,950 hectares), and Shellrock (64,000 acres; 25,900 hectares) fires swept across much of the area that was sampled. Thus, these data represent a pre-fire baseline geochemical dataset. A 2001 post-fire study is planned and will involve re-sampling of the pre-fire baseline sites, to allow for pre- and post-fire comparison. Sampling was conducted from July 8-28, 1996. Weather during this period was warm and precipitation sparse. Only one rain event occurred during the sampling period—a brief rain storm on the evening of July 16, with about ¼” (0.64 cm) of total precipitation. River levels were lower than normal for this time of year because of lower-than-normal precipitation during
the previous winter and spring. The study area lies within the Salmon River Mountains, and much of the area— particularly along the Middle Fork of the Salmon River—lies within the Frank Church-River of No Return Wilderness (Fig. 1). Topographic relief is high. Peaks at the heads of drainages commonly have elevations above 9000 ft (2740 m), while river-level elevations are typically several thousand feet lower, ranging from around 5700 ft (1740 m) at Boundary Creek on the Middle Fork of the Salmon River, to less than 3000 ft (914 m) at Corn Creek on the Main
Salmon River. Terrain ranges from rugged, steep peaks, ridges, and cirques at higher elevations,
through tree-covered mountains and meadows at intermediate elevations, to steep, narrow, heavily vegetated canyons at lower elevations. Climatic conditions vary from warm summer days with frequent thunderstorms to cold winter days with heavy snowfall accumulations. Access to the Panther Creek basin is by U.S. Forest Service gravel roads 030 from North Fork, Idaho, and 055, which runs along Panther Creek. Access to the Main Salmon River from North Fork to Corn Creek is by U.S. Highway 93 and U.S. Forest Service gravel road 030, which runs along the Main Salmon, ending at Corn Creek, and by raft or jet boat. Access to the Middle Fork of the Salmon River is exclusively by oar-powered raft or pack trail.

OVERVIEW OF ENVIRONMENTAL ANALYSIS


A. INTRODUCTION
1. Environmental Analysis
Environmental analysis, as used in these notes, is the chemical (or physical) characterization of some component of the natural or engineered environment. One may speak of four facets to environmental analysis:
1. Analytical Methods
2. Sampling Protocol
3. Quality Control
4. Data Analysis
The first, analytical methods, is what one most commonly associates with chemical analysis of the environment. It is the recipe or set of laboratory procedures one follows in order to obtain a signal that can be related to the concentration of the analyte. Analytical methods are presented in Chapters XV-XXII, and grouped according to the instrument or apparatus used. The second facet, sampling protocol, is sometimes trivial, yet sometimes very important and complex. Sampling is the means by which a subset of the environmental matrix of interest is selected, stored and transported to the laboratory for analysis (Chapter XIII). Then, quality control, is a set of procedures which are intended to warn the analyst when his/her analytical method is not working properly (Chapter XII). Some of these procedures may be implicitly writted into the analytical method. Finally, data analysis, is required to place the analytical results into the framework of a numerical value with uncertainty. Statistical theory plays an important role in this process, and this subject is treated in Chapter XXIII.
2. Analytical Methods

supplemental Material and Method

[PDF] Figure Legends - [ Terjemahkan laman ini ]
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Aliquots were then analyzed for Ag, Al, As, Ba, Be, Ca, Cd, Co,. Cr, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sr, Te, Ti, V, Y, Zn, and Zr ...


Supplemental Materials and Methods
SWCNT particles
Commercially manufactured raw SWCNT made by the Arc method in specifically designed chambers was obtained through collaboration with the National Institute of Standards and Technology (NIST, Gaithersburg, MD. The SE grade SWCNT manufactured by CarboLex was reported to have a purity of 70-90% and contained catalyst impurities encapsulated in carbon shells (Carbolex Inc., Broomall, PA). Some amorphous carbon was also found on the outer surfaces of the ropes. The SWCNT were heated by the manufacturer to 2,800° C in an argon atmosphere using a graphite furnace to improve structural integrity and to remove polyaromatic hydrocarbons and a significant amount of iron. The individual SWCNT are self-assembled into a rope bundle structure. SWCNT manufactured by this method are reported to have an average diameter of 1.4 nm with lengths of 2-5 μm.

Monday, April 6, 2009

GMELIN, Handbook of Inorganic and Organometallic Chemistry

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system, or Mn, Fe, Co, Ni, as well as a nonmetal element. Concludes the series on the purely ...... compounds, as well as detection and determination, conclude the ..... Ca, Mg, B, Al, Ga, In, Tl, Si, Ge, Sn, and Pb. Contains the formula ...... covered contain Sb, Bi, Zn, Hg, Al, Ti, Zr, Hf, Th, Sn, Pb, V, Ta, Cr, ...
ublib.buffalo.edu/libraries/asl/guides/Gmelin-Complete-Catalog.pdf - Halaman sejenis

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