A short history of the early scientific developments related to the optical emission lines of hydrogen is presented. These were crucial to the development of the quantum theory. Balmer's empirical formula was an important milestone. Rydberg and others provided additional work, especially for higher atomic numbers. However, it remained for Bohr to provide the physical reasoning.
Nov 1, 2008
By:
Volker Thomsen
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A short history of the early scientific developments related to the optical emission lines of hydrogen is presented. These were crucial to the development of the quantum theory. Balmer's empirical formula was an important milestone. Rydberg and others provided additional work, especially for higher atomic numbers. However, it remained for Bohr to provide the physical reasoning.
Jul 1, 2008
By:
Volker Thomsen
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Volker Thomsen takes a look at the impact that the discovery of X-rays by Wilhelm Röntgen in 1895 has had on the world.
May 1, 2008
By:
Steve Wilbur
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While inductively coupled plasma-mass spectrometry (ICP-MS) is capable of part-per-quadrillion (ppq) detection limits under ideal conditions, most applications do not require this level of sensitivity and do not justify the cost associated with achieving it. Practical sensitivity in ICP-MS is determined not by instrument signal-to-noise ratio, but rather by controlling interferences and matrix effects in real samples. Understanding the sources of these effects and their management is critical in determining the most practical way to achieve specific data quality objectives.
Apr 1, 2008
By:
Kenneth Neubauer
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Speciation analysis has grown rapidly and has expanded to a variety of markets, including environmental, clinical, food, nutraceutical, and bioanalytical. This growth has resulted from the realization that knowing the total amount of an element does not always provide adequate information for assessing health and environmental effects, but knowing which form of the element is present presents a much more comprehensive picture.
Mar 1, 2006
By:
Jordan Valley AR, Inc.
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Simple, fast, and reliable on-site hydraulic oil analysis should be an integral part of any preventative maintenance program. Since the majority of machine failures are contamination related, it is important to analyze the hydraulic fluid to monitor equipment condition and identify machine wear. Significant cost savings can result from early identification of machine failure, oil quality, handling and other problems. Oil analysis can detect changes in oil quality, contamination, wear and chemical differences. Benefits of this information include prolonged equipment life, reduced equipment downtime, and reduced overall maintenance costs. In addition, plants can increase intervals between oil changes, thus reducing waste oil, maintenance, and oil purchase costs.
Mar 1, 2006
By:
Thanos Pantazis, Amptek, Inc.
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The RoHS/WEEE directive requires the electronics industry to certify that products comply with maximum concentration amounts of particular elements and compounds (Cr VI, Pb, Cd, Hg, Br PBB/PBDE) by July 2006. Instrumentation must be developed to perform the certification.
