Slurry, Solution and Speciation Analysis By Inductively Coupled Plasma Atomic Emission Spectrometry

Inductively coupled plasma atomic emission spectrometry has been investigated for solution, slurry and speciation analysis. It has been shown that it is possible to optimise a simultaneous multielement analysis for slurry and solution samples using solid state detection and optimisation algorithms. A range of certified reference materials have been analysed using optimum conditions and results were in good agreement with certified values. Slurry nebulisation has been used for the first time in the analysis of NIST SRM Total Diet' and carbon black samples. Both radially and axially viewed ICP spectrometers were used in these studies. Modifications of the mass transport efficiency of solutions and slurries through the sample introduction system was illustrated upon EIE addition. The transport phenomenon was found to be dependent on the matrix element and not on the analyte of interest. A decrease in transport efficiency was found to be related to the mass of the EIE added. Solution and slurry atom and ion line intensity ratios obtained from an axially viewed ICP were used to illustrate emission enhancement when Mg was used as the thermometric species of interest. Enhancement was found to be spatially dependent and the energy transfer processes governing excitation were modified upon EIE addition. The magnitude of the enhancement effects for solutions and slurries differed, once transport effects had been negated, and this was attributed to variations in atomisation efficiency. A radially viewed ICP spectrometer was also used to monitor the effect of ElEs on solutions and slurries. The Abel integral technique was used to transform lateral profiles and Fe atom line ratios were calculated. 'Real' enhancement effects were apparent upon EIE addition when transport effects had again been negated. The plasma excitation temperature was used as a physical marker to determine the effect of EIE addition on solutions and slurries of Fe. The variation in Texc upon EIE addition was small but showed an increasing trend from Li to Cs. Radially obtained values of Texc were lower than literature values whereas preliminary values obtained axially compared well. It has been demonstrated that transient signal data may be obtained from an array-based spectrometer for speciation studies. The feasibility of reverse phase and size exclusion HPLC-ICP-AES has been demonstrated for the separation of a selection of organosilicon species of various molecular weights. Detection limits were in the range 0.1 to 5 ug ml-1 for a radially viewed plasma. The use of axial viewing when aspirating organic solvents as part of the mobile phase yields higher limits of detection owing to the noise that is measured.The Perkin-Elmer Corp. 761 Main Ave.. Nonwalk, CT 06897, US

Hot Topics on the Web Strategies for Research

Some of the pitfalls of research on the Web are highlighted and exacerbated when the type of research being done is for "hot," controversial, or debatable topics. Who to trust, where to find the information, and how to determine what is reliable are all questions that will present themselves. However, the resources available on the Web are well suited for addressing many of the challenges of hot topic research. Finding points of view for obscure and well-known advocacy groups, finding the most current legislation on an issue, and finding recent events related to the issue are all actually enhanced and made easier by researching a topic on the Web. Knowing the pitfalls and benefits from the outset can make using the Web much more profitable for hot topics research. By using appropriate sites for topic identification, you can quickly build a useful collection of core sites. By knowing where to identify federal and state legislation, you can determine the state of current policy on a topic. And certainly, the Web is most likely to help with timely news and insight on advocacy groups that might provide no—or hard-to-find—printed materials on their positions. The following strategies and sources will facilitate efficient use of the Web for hot topics research that results in a full, well-informed view of the topic

Alternate metabolism during the dauer stage of the nematode Caenorhabditis elegans

When environmental conditions are unsuitable to support nematode reproduction, Caenorhabditis elegans arrests development before the onset of sexual maturity and specialised âdauerâ larvae, adapted for dispersal, and extended diapause are formed. Dauer larvae do not feed and their metabolism is dependent on internal food reserves. Adult worms which express defects in the insulin/insulin-like growth factor receptor DAF-2 also display enhanced longevity. Whole genome mRNA expression profiling has demonstrated that C. elegans dauer larvae and daf-2 adults have similar transcription profiles for a cohort of longevity genes. Important components of this enhanced longevity system are the a-crystallin family of small heat shock proteins, anti-ROS defence systems, increased activity of cellular detoxification processes and possibly also increased chromatin stability and decreased protein turnover. Anaerobic fermentation pathways are upregulated in dauer larvae, while long-lived daf-2 adults appear to have normal oxidative metabolism. Anabolic pathways are down regulated in dauer larvae (and possibly in daf-2 adults as well), and energy consumption appears to be diverted to enhanced cellular maintenance and detoxification processes in both systems

Learning Objects for Library Instruction

This presentation was given at the Spring Workshop of the Academic Library Association of Ohio (ALAO) Instruction Interest Group on April 23, 2004. It discusses theory of learning objects and provides examples of learning object repositories. Techniques and software useful for building interactive learning objects, such as simulations, games, guided tasks (action mazes and Web Quests) are described. Evaluation of learning objects and use of the National Learning Infrastructure Initiative (NLII) observation tool are also covered. A workshop activity and a resource list are included

Online Searching Skills: Development of an Inventory to Assess Self-Efficacy

Final revised version of article and the instrument.An instrument measuring online searching self-efficacy beliefs was developed. Several hypotheses related to self-efficacy and performance on assignments were tested. Students' efficacy beliefs rose significantly after an online course, and were related to good performance on assignments. The instrument may be used to measure changes in student attitudes after instruction

A Game-Based Multimedia Approach to Library Orientation

The Ohio State University Libraries Instruction Office, in collaboration with the Office of First Year Experience, created an innovative series of casual, interactive online games (matching, puzzles, crossword, multiple guess) to orient incoming freshmen to library resources. This presentation, given at the LOEX 2007 Conference in San Diego, California (May 2007), discusses the design and development process