This article critically examines the use of factorial and response surface methodology in modern experimental design and optimization. A survey of important screening and optimization techniques in ...the literature since 2000 are presented. Current applications in biological, environmental and pharmaceutical analysis, food technology and industrial-related processes are examined.
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"Drawing on the experience and knowledge of a practicing professional, this book provides a comprehensive introduction and practical guide to the development, optimization, and application of ...artificial neural networks (ANNs) in modern environmental and biological analysis. Based on our knowledge of the functioning human brain, ANNs serve as a modern paradigm for computing. Presenting basic principles of ANNs together with simulated biological and environmental data sets and real applications in the field, this volume helps scientists comprehend the power of the ANN model to explain physical concepts and demonstrate complex natural processes"--
"The cornerstones of research into prospective tools of artificial intelligence originate from knowledge of the functioning brain. Like most transforming scientific endeavors, this field-- once viewed with speculation and doubt--has had profound impacts in helping investigators elucidate complex biological, chemical, and environmental processes. Such efforts have been catalyzed by the upsurge in computational power and availability, with the co-evolution of software, algorithms, and methodologies contributing significantly to this momentum. Whether or not the computational power of such techniques is sufficient for the design and construction of truly intelligent neural systems is of continued debate. In writing Artificial Neural Networks in Biological and Environmental Analysis, my aim was to provide in-depth and timely perspectives on the fundamental, technological, and applied aspects of computational neural networks. By presenting basic principles of neural networks together with real applications in the field, I seek to stimulate communication and partnership among scientists in the fields as diverse as biology, chemistry, mathematics, medicine, and environmental science. This interdisciplinary discourse is essential not only for the success of independent and collaborative research and teaching programs, but also for the continued acquiescence of the use of neural network tools in scientific inquiry"--
Little is known about the prebiotic mechanisms that initiated the bioavailability of phosphorus, an element essential to life. A better understanding of phosphorus speciation in modern earth ...environments representative of early earth may help to elucidate the origins of bioavailable phosphorus. This paper presents the first quantitative measurements of phosphite in a pristine geothermal pool representative of early earth. Phosphite and phosphate were initially identified and quantified in geothermal pool and stream samples at Hot Creek Gorge near Mammoth Lakes, California, using suppressed conductivity ion chromatography. Results confirmed the presence of 0.06 ± 0.02 μM of phosphite and 0.05 ± 0.01 μM of phosphate in a geothermal pool. In the stream, phosphite concentrations were below detection limit (0.04 μM) and phosphate was measured at 1.06 ± 0.36 μM. The presence of phosphite in the geothermal pool was confirmed using both chemical oxidation and ion chromatography/mass spectrometry.
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Neural network computing demonstrates advanced analytical problem solving abilities to meet the demands of modern chemical research. (To listen to a podcast about this article, please go to the ...Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html .).
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Use chemometric techniques to develop optimum separation conditions for capillary electrophoreses For all its advantages, capillary electrophoresis (CE) also carries significant disadvantages for the ...researcher. Offering a unique blend of information from authors active in a variety of developments of chemometrics in CE, Chemometric Methods in Capillary Electrophoresis presents modern chemometric methods as an alternative to help alleviate the problems commonly encountered during routine analysis and method development. Focusing on current chemometric methods utilized in CE endeavours by research-active experts in the field, the book begins with a thorough introduction to CE and chemometric-related concepts and the need for modern chemometric methods in CE. Part 1 discusses differing types of screening designs and response surface methodology¿in an¿application based format Part 2 includes vital discussion on various exploratory data analysis, prediction, and classification techniques utilized in CE-related studies Part 3 provides practical information on modelling quantitative structure relationships Part 4 explores transformation techniques, in particular fundamental studies and applications of cross-correlation and Hadamard Transform Electrophoresis Showing how chemometric methods are applied in a wide array of applications including biological, medical, pharmaceutical, food, forensic, and environmental science, Chemometric Methods in Capillary Electrophoresis is not only highly significant to capillary electrophoresis-based endeavours, but instructive for investigators active in other areas of separation science who could benefit from its informative content.
A current problem in microfluidics is that poly(dimethylsiloxane) (PDMS), used to fabricate many microfluidic devices, is not compatible with most organic solvents. Fluorinated compounds are more ...chemically robust than PDMS but, historically, it has been nearly impossible to construct valves out of them by multilayer soft lithography (MSL) due to the difficulty of bonding layers made of "non-stick" fluoropolymers necessary to create traditional microfluidic valves. With our new three-dimensional (3D) valve design we can fabricate microfluidic devices from fluorinated compounds in a single monolithic layer that is resistant to most organic solvents with minimal swelling. This paper describes the design and development of 3D microfluidic valves by molding of a perfluoropolyether, termed Sifel, onto printed wax molds. The fabrication of Sifel-based microfluidic devices using this technique has great potential in chemical synthesis and analysis.
The swarm intelligence (SI) computing paradigm has proven itself as a comprehensive means of solving complicated analytical chemistry problems by emulating biologically-inspired processes. As global ...optimum search metaheuristics, associated algorithms have been widely used in training neural networks, function optimization, prediction and classification, and in a variety of process-based analytical applications. The goal of this review is to provide readers with critical insight into the utility of swarm intelligence tools as methods for solving complex chemical problems. Consideration will be given to algorithm development, ease of implementation and model performance, detailing subsequent influences on a number of application areas in the analytical, bioanalytical and detection sciences.
The aim of this paper was to examine historical physico-chemical water quality parameters (1990–1997) in the River Frome, East Stoke (NGR SY867868), in order to show both annual and seasonal ...(monthly) trends. EpCO
2 (defined as the partial pressure of CO
2 in natural water divided by the equilibrium partial pressure of CO
2) levels ranged from mean values of 6.32±0.41 in spring/summer to 7.86±1.17 in autumn/winter. A decreasing trend in mean annual EpCO
2 was also observed, with a high of 9.61 in 1990 and a low of 5.22 in 1996. The variations were attributed to changes in pH, which showed an inverse relationship with river discharge (
r
2=0.47). Both pH and EpCO
2 levels were strongly linked to biological activity with increases caused by primary productivity. Filterable reactive phosphorus (FRP) and total phosphorus (TP) concentrations correlated with river discharge. The results showed that the majority of the phosphorus load was transported during storm events, which agrees with results from an export coefficient model predicting phosphorus loading in the Frome catchment. Recent River Frome monitoring campaigns using an in situ flow-injection (FI)-based monitor were in agreement with phosphorus concentration and related physico-chemical trends observed during historical sampling and laboratory analysis.
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Electrostatic complexes containing a cationic conjugated oligoelectrolyte (COE) and fluorescein (FAM)-labeled single-stranded DNA (ssDNA) serve as the basis for identifying various bacteria. The ...approach involves the preparation of five COE/ssDNA x -FAM electrostatic complexes, which differ in the ssDNA composition and which provide different photoluminescence (PL) spectra as a result of different degrees of energy transfer efficiency from the COE to FAM. Changes in the PL spectra upon addition of the bacteria can be quantified, and the differential response from the five ssDNAs gives rise to a multicomponent array response that allows identification of the microorganism under investigation.
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