bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric 1,4-Addition of Arylboronic Acids to α,β-Unsaturated Aldehydes Catalyzed by a Chiral Diene–Rhodium Complex
Authors: Hayashi Tamio , Tokunaga Norihito , Okamoto Kazuhiro , Shintani Ryo
Published: September 2005

Asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated aldehydes proceeded in the presence of a rhodium catalyst (3 mol %) coordinated with a chiral diene ligand ((R,R)-Bn-bod*) to give the corresponding β-arylaldehydes with perfect 1,4-selectivity and with 88–97% enantioselectivity.
Fabrication of Metal Cadmium Nanowires by an Assistant Thermal Decomposition Method
Authors: Zhao Jian-wei , Ye Chang-hui , Fang Xiao-sheng , Yan Peng , Zhang Li-de
Published: September 2005

Using a simple assistant thermal decomposition method, metal cadmium nanowires were large-scale fabricated from CdS powders in an argon atmosphere. Investigation results demonstrate that the Cd nanowires have lengths of several microns and diameter of about 70–150 nm.
Confocal Laser Scanning Microscope Analysis of Antimony Porphyrin Chromophore Immobilized on Silica-gel Beads
Authors: Matsumoto Jin , Fuchikawa Tomokazu , Komiya Yasuhiro , Fueda Yoshiyuki , Matsumoto Tomoko , Shiragami Tsutomu , Yasuda Masahide
Published: September 2005

Dihydroxoantimony(V) tetraphenylporphyrin chromophore (SbTPP) was immobilized on 3-aminopropyl-silica gel (NH2–SiO2) by the reaction of dihydroxoantimony [4-(N-succinimidyloxycarbonyl)phenyl]triphenylporphyrin with NH2–SiO2. Spectroscopic analysis of the complex by confocal laser scanning microscope suggested the interaction of SbTPP with the residual amino group on SiO2. The photoreaction of the complex with Et2NH induced the demetallation.
Efficient Oxidation of Alkane with O2 and H2 by Eu–Ti–Pt Catalytic System
Authors: Yamanaka Ichiro , Gomi Toshikazu , Nabeta Takashi , Otsuka Kiyoshi
Published: September 2005

Alkane was efficiently oxidized to alcohol and ketone with O2 and H2 by EuCl3–TiO(acac)2–Pt/SiO2 catalytic system with very high H2-utilization efficiencies, 75% for adamantane and 60% for cyclohexane oxidations. ESR studies suggested that electrons originated in H2 effectively conducted to O2 through Pt, Eu3+/Eu2+, and Ti4+/Ti3+. Eu2+ and Ti3+ species reductively activated O2, generating active oxygen species.
Compression of Single Conjugated-polymer Nanoparticles with AFM Tips
Authors: Zhou Xingfei , Xu Hui , Fan Chunhai , Sun Jielin , Zhang Yi , Li Minqian , Shen Wenqing , Hu Jun
Published: September 2005

A water-soluble conjugated polymer, poly[lithium 5-methoxy-2-(4-sulfobutoxy)-1,4-phenylenevinylene] (MBL-PPV), spontaneously forms nanoparticles at flat mica surfaces. In this work, we manipulated single PPV nanoparticles with a modified version of AFM, our recently developed vibrating scanning polarization force microscopy (VSPFM). VSPFM provides a new way to obtain undistorted imaging of “soft” molecules at surfaces. We have demonstrated that we could stepwise compress a single PPV nanoparticle with an AFM tip and estimate its compression elasticity in a small force regime.
Estimating RNA editing efficiency of five editing sites in the serotonin 2C receptor by pyrosequencing
Authors: IWAMOTO KAZUYA , BUNDO MIKI , KATO TADAFUMI
Published: September 2005

Accumulating evidence suggests that altered RNA editing of the serotonin 2C receptor (HTR2C) is involved in the pathophysiology of mental disorders and the action of antidepressants. Estimating RNA editing of HTR2C in various samples is a first step to understanding its pathophysiological roles. Here, we developed a high-throughput quantification method of RNA editing efficiency by pyrosequencing. By optimizing the dispensation order, the RNA editing efficiency of all five RNA editing sites including consecutively ordered sites in HTR2C was obtained. More importantly, our method made it possible to determine the content of partial HTR2C isoforms, which enabled us to monitor possible functional changes of HTR2C. This method was validated in both oligonucleotide and RT-PCR product templates, and showed good correlation with conventional cloning-sequencing analysis. Our method could be a valuable tool in the rapid assessment of RNA editing status, including assessment of natural variations, alterations in disease tissues, and responses to drugs.
Competitive regulation of modular allosteric aptazymes by a small molecule and oligonucleotide effector
Authors: NAJAFI-SHOUSHTARI S. HANI , FAMULOK MICHAEL
Published: September 2005

The hairpin ribozyme can catalyze the cleavage of RNA substrates by employing its conformational flexibility. To form a catalytic complex, the two domains A and B of the hairpin-ribozyme complex must interact with one another in a folding step called docking. We have constructed hairpin ribozyme variants harboring an aptamer sequence that can be allosterically induced by flavin mononucleotide (FMN). Domains A and B are separated by distinct bridge sequences that communicate the formation of the FMN-aptamer complex to domains A and B, facilitating their docking. In the presence of a short oligonucleotide that is complementary to the aptamer, catalytic activity of the ribozyme is completely abolished, due to the formation of an extended conformer that cannot perform catalysis. However, in the presence of the small molecule effector FMN, the inhibitory effect of the oligonucleotide is competitively neutralized and the ribozyme is activated 150-fold. We thus have established a new principle for the regulation of ribozyme catalysis in which two regulatory factors (an oligonucleotide and a small molecule) that switch the ribozyme’s activity in opposite directions compete for the same binding site in the aptamer domain.
Maximizing Accuracy of Shared Databases when Concealing Sensitive Patterns
Authors: Menon Syam , Sarkar Sumit , Mukherjee Shibnath
Published: September 2005

The sharing of databases either within or across organizations raises the possibility of unintentionally revealing sensitive relationships contained in them. Recent advances in data-mining technology have increased the chances of such disclosure. Consequently, firms that share their databases might choose to hide these sensitive relationships prior to sharing. Ideally, the approach used to hide relationships should be impervious to as many data-mining techniques as possible, while minimizing the resulting distortion to the database. This paper focuses on frequent item sets, the identification of which forms a critical initial step in a variety of data-mining tasks. It presents an optimal approach for hiding sensitive item sets, while keeping the number of modified transactions to a minimum. The approach is particularly attractive as it easily handles databases with millions of transactions. Results from extensive tests conducted on publicly available real data and data generated using IBM’s synthetic data generator indicate that the approach presented is very effective, optimally solving problems involving millions of transactions in a few seconds.
IT Human Resource Management Configurations and IT Turnover: Theoretical Synthesis and Empirical Analysis
Authors: Ferratt Thomas W. , Agarwal Ritu , Brown Carol V. , Moore Jo Ellen
Published: September 2005

Increasingly, scholars and practitioners acknowledge that information technology (IT) human capital is a strategic resource and that its effective management represents a significant organizational capability. We use configurational theory to examine organizational practices related to the management of IT human capital. In contrast to much prior work in IT human resource management (HRM) that is focused at the individual level, our inquiry is focused at the organizational level of analysis. Building on strategic human resource management (SHRM) research in general and research on the management of IT professionals in particular, we examine the broad question: Are different configurations of IT HRM practices associated with different IT staff turnover rates? A multidimensional view of IT HRM practices is presented, based on prior IT and SHRM literature. We formalize hypotheses regarding the relationship of turnover with configurations of IT HRM practices grounded in prior theory and empirical research. Based on survey responses from 106 organizations, IT HRM dimensions and configurations are derived and the hypotheses are tested. A five-configuration solution, obtained via cluster analysis, includes two contrasting configurations consistent with two archetypes found in the prior literature. Specifically, the configuration with a human capital focus has lower turnover than the task-focused configuration, providing support for our first hypothesis. Although the hypothesis on intermediate configurations and their relationship with turnover is not supported, we discover and interpret three additional configurations that embody patterns of practices with unique emphases. Theoretical and practical implications of the findings are discussed.
Editorial Notes
Authors: Sambamurthy Vallabh
Published: September 2005

This editorial announces a new special issue calling for research on the interplay between digital and social networks. Today, both digital and social networks play a crucial role in the structure and conduct of economic activity. Therefore, ISR seeks to foster research on this important topic. We also note with sadness the passing of a valued member of the information systems community, a great colleague, and a former member of the editorial board of the journal. Finally, a new senior editor is introduced.
A Semidefinite Programming Approach to Optimal-Moment Bounds for Convex Classes of Distributions
Authors: Popescu Ioana
Published: September 2005

We provide an optimization framework for computing optimal upper and lower bounds on functional expectations of distributions with special properties, given moment constraints. Bertsimas and Popescu (Optimal inequalities in probability theory: a convex optimization approach. SIAM J. Optim. 2004. Forthcoming) have already shown how to obtain optimal moment inequalities for arbitrary distributions via semidefinite programming. These bounds are not sharp if the underlying distributions possess additional structural properties, including symmetry, unimodality, convexity, or smoothness. For convex distribution classes that are in some sense generated by an appropriate parametric family, we use conic duality to show how optimal moment bounds can be efficiently computed as semidefinite programs. In particular, we obtain generalizations of Chebyshev’s inequality for symmetric and unimodal distributions and provide numerical calculations to compare these bounds, given higher-order moments. We also extend these results for multivariate distributions.
Optimal Investments for Robust Utility Functionals in Complete Market Models
Authors: Schied Alexander
Published: September 2005

This paper introduces a systematic approach to the problem of maximizing the robust utility of the terminal wealth of an admissible strategy in a general complete market model, where the robust utility functional is defined by a set 𝒬 of probability measures. Our main result shows that this problem can often be reduced to determining a “least favorable” measure Q0 ∈ 𝒬, which is universal in the sense that it does not depend on the particular utility function. The robust problem is thus equivalent to a standard utility-maximization problem with respect to the “subjective” probability measure Q0. By using the Huber-Strassen theorem from robust statistics, it is shown that Q0 always exists if 𝒬 is the σ-core of a 2-alternating capacity. Besides other examples, we also discuss the problem of robust utility maximization with uncertain drift in a Black-Scholes market and the case of “weak information.”
Error Bounds for Degenerate Cone Inclusion Problems
Authors: He Yiran , Sun Jie
Published: September 2005

Error bounds for cone inclusion problems in Banach spaces are established under conditions weaker than Robinson’s constraint qualification. The results allow the cone to be more general than the origin and therefore also generalize a classical error bound result concerning equality-constrained sets in optimization. Applications in finite-dimensional differentiable inequalities and in tangent cones are discussed.
An Alternative Algorithm for Counting Lattice Points in a Convex Polytope
Authors: Lasserre Jean B. , Zeron Eduardo S.
Published: September 2005

We provide an alternative algorithm for counting lattice points in the convex polytope {x ∈ ℝn ∣ Ax = b, x ≥ 0}. It is based on an exact (tractable) formula for the case A ∈ ℤm×(m+1) that we repeatedly use for the general case A ∈ ℤm×n.
The Scenario Generation Algorithm for Multistage Stochastic Linear Programming
Authors: Casey Michael S. , Sen Suvrajeet
Published: September 2005

A multistage stochastic linear program (MSLP) is a model of sequential stochastic optimization where the objective and constraints are linear. When any of the random variables used in the MSLP are continuous, the problem is infinite dimensional. To numerically tackle such a problem, we usually replace it with a finite-dimensional approximation. Even when all the random variables have finite support, the problem is often computationally intractable and must be approximated by a problem of smaller dimension. One of the primary challenges in the field of stochastic programming deals with discovering effective ways to evaluate the importance of scenarios and to use that information to trim the scenario tree in such a way that the solution to the smaller optimization problem is not much different from the problem stated with the original tree. The scenario generation (SG) algorithm proposed in this paper is a finite-element method that addresses this problem for the class of MSLP with random right-hand sides.
Exponential Lower Bounds on the Lengths of Some Classes of Branch-and-Cut Proofs
Authors: Dash Sanjeeb
Published: September 2005

We examine the complexity of branch-and-cut proofs in the context of 0-1 integer programs. We establish an exponential lower bound on the length of branch-and-cut proofs that use 0-1 branching and lift-and-project cuts (called simple disjunctive cuts by some authors), Gomory-Chvátal cuts, and cuts arising from the N0 matrix-cut operator of Lovász and Schrijver. A consequence of the lower-bound result in this paper is that branch-and-cut methods of the type described above have exponential running time in the worst case.
Convergence of Successive Approximation Methods with Parameter Target Sets
Authors: Levy Adam B.
Published: September 2005

Successive approximation methods appear throughout numerical optimization, where a solution to an optimization problem is sought as the limit of solutions to a succession of simpler approximation problems. Such methods include essentially any standard penalty method, barrier method, trust region method, augmented Lagrangian method, or sequential quadratic programming (SQP) method, as well as many other methods. The approximation problems on which a successive approximation method is based typically depend on parameters, in which case the performance of the method is related to the corresponding sequence of parameters. For many successive approximation methods, the sequence of parameters might need only approach some parameter target set for the method to have nice convergence properties. Successive approximation methods could be analyzed as examples of a generic inclusion solving method from Levy [23] because the solutions to the approximation problems satisfy necessary optimality inclusions. However, the inclusion solving method from Levy [23] was developed for single-parameter target points. In this paper, we extend the results from Levy [23] to allow parameter target sets and apply these results to the convergence analysis of successive approximation methods. We focus on two important convergence issues: (1) the rate of convergence of the iterates generated by a successive approximation method and (2) the validity of the limit as a solution to the original problem. An augmented Lagrangian method allowing quite general parameter updating is explored in detail to illustrate how the framework presented here can expose interesting new alternatives for numerical optimization.
An Investigation into Merseyside General Dental Practitioners’ Interest in Primary Care Research, Their Views on Research and Their Training Needs
Authors: Palmer Nikolaus OA , Grieveson Brian
Published: September 2005

Objectives

The aims of this investigation were to evaluate the interests of primary care dental practitioners within the Mersey Postgraduate Deanery in research and their views on research, their experience and research training needs.

Method

A questionnaire was sent to all practitioners in the Mersey Deanery asking for views on dental research, whether they had been involved in any research projects or had any research training, and whether they would be interested in research training and being part of a primary dental care research network.

Results

A total of 192 practitioners from the 1120 in the Mersey Deanery expressed an interest in being involved in primary care research. Most believed that primary care research was very important in providing a stronger evidence-base in dentistry and improved quality of dental care. Over 50% of respondents were interested in collaborative research, provided that their income and time could be protected and it was part of the normal working day. Almost 25% had some research experience and a number had undergone research training, ranging from informal training to part of a degree.

Conclusions

A number of GDPs in the Mersey Deanery are interested in primary care research. With appropriate training, support and recognition within the new Personal Dental Services (PDS) contracts, there is a golden opportunity for more primary care dentists to participate in research. This, in time, will add to the evidence base in dentistry and should improve patient care.
Darbepoetin Alfa Therapeutic Interchange Protocol for Anemia in Dialysis
Authors: Brophy Donald F , Ripley Elizabeth BD , Kockler Denise R , Lee Seina , Proeschel Lori A
Published: September 2005

BACKGROUND

Erythropoiesis-stimulating proteins, such as erythropoietin alfa and darbepoetin alfa, have positively impacted anemia management. These medications improve patient outcomes and quality of life. Their costs, however, remain a major barrier for health systems.

OBJECTIVE

To evaluate the development, implementation, and cost-effectiveness of an inpatient therapeutic interchange protocol for erythropoiesis-stimulating proteins at a large, tertiary care, university-affiliated health system.

METHODS

Virginia Commonwealth University Health System (VCUHS) developed and implemented a therapeutic interchange program to convert therapy for all inpatients undergoing dialysis from erythropoietin alfa to darbepoetin alfa for treatment of chronic kidney disease–related anemia. An evaluation of the economic impact of this program on drug expenditures over a fiscal quarter (2003) was conducted using historical comparator data (2002).

RESULTS

Preliminary evaluation of the program demonstrated cost-savings and reduced drug utilization of erythropoiesis-stimulating proteins in hospitalized dialysis patients. For the first quarter of 2003 compared with the first quarter of 2002, VCUHS realized a cost-savings of nearly $10 000, which was related to the program's aggressive screening procedure. When these data were normalized for equal numbers of patients in each group receiving one of the drugs, the actual cost-savings was over $2000. These cost-savings are largely due to reduced utilization of these expensive biotechnology products with implementation of a dosing protocol.

CONCLUSIONS

VCUHS has successfully developed and implemented a darbepoetin alfa therapeutic interchange protocol for hospitalized dialysis patients. This has translated into reduced use of erythropoiesis-stimulating proteins, resulting in cost-savings for the health system.
On the Selection of Analysis Lines in Atomic Absorption Spectrometry
Authors: Parsons M. L. , Smith B. W. , McElfresh P. M.
Published: September 2005

A comprehensive study of theoretical atomic absorbances has been made for most analytically useful elements, the only exceptions being the rare earths. These data have been compared with experimentally determined atomic absorbances in many cases. The importance of the low lying energy levels has been emphasized as well as the need for better atomic transition probability data.

The choice of analysis line is discussed from both the theoretical and experimental points of view, and tables of relative atomic absorbances are given with their temperature variations where appropriate.
Considerations for Infrared Ultramicrosampling
Authors: Griffiths Peter R. , Block Frank
Published: September 2005

Factors determining the sensitivity of infrared microsampling are discussed. Experiments are described to explain the sample loss that occurs during the preparation of KBr microdisks using organic molecules of fairly low volatility. The principal loss in these experiments happens because of evaporation of the sample while the mixture with KBr is being transferred to the die. If solvent had to be evaporated from the sample prior to preparing the disk, the main loss would occur during this step. It is suggested that the use of dilute solutions in small volume will lead to greater potential sensitivity than the microdisk technique, even though cells of greater cross sectional area may have to be used.
General Notation for Polarized Raman Scattering from Gases, Liquids, and Single Crystals
Authors: Swanson Basil I.
Published: September 2005

A completely general notation for polarized Raman scattering from gases, solutions, liquids, and single crystals is presented. This notation can be used to describe scattering from single crystals where more general crystallographic directions are employed. Scattering experiments where nonpolarized incident light is used, or where both polarization components of scattered light are observed, can also be labeled. Single crystal scattering efficiencies are discussed in terms of the generalized notation.
Interpretation of Infrared Spectra Using Pattern Recognition Techniques
Authors: Liddell Robert W. , Jurs Peter C.
Published: September 2005

The pattern recognition technique utilizing adaptive binary pattern classifiers has been applied to the interpretation of infrared spectra. The binary pattern classifiers have been trained to determine the chemical classes of x-y digitized infrared spectra. High predictive abilities have been obtained in classifying unknown spectra. A new training procedure for binary pattern classifiers has been developed, and it has been used to classify ir spectra into chemical classes. Pattern classifiers trained in the conventional way and by the new procedure have been used in conjunction with feature selection, and it is shown that a small fraction of the data is necessary to classify these infrared spectra successfully into chemical classes.
Quantitative Evaluation of Degree of Internal Standardization in X-ray Fluorescence Analysis Using Scattered X-rays
Authors: Taylor D. L. , Andermann G.
Published: September 2005

The “degree of internal standardization” for the scattered radiation method of compensation for matrix effects in x-ray fluorescence analysis is defined as the closeness of agreement between the results of analyses of specimens containing identical concentrations of analyte but with differing over-all elemental constituencies. The definition is derived in mathematical terms and is applied to experimental data of analyses of calcium in aqueous solutions containing different dissolved substances as matrix variants. The matrix compensation effectiveness of various wavelengths of scattered radiation can be clearly indicated. Interpretation of the results in terms of basic spectroscopic parameters is offered.
High Resolution Atomic Absorption Spectrometry with a Scanning Fabry-Perot Interferometer
Authors: Veillon Claude , Merchant Philip
Published: September 2005

A stable, piezoelectric scanning Fabry-Perot interferometer is used in conjunction with a conventional grating monochromator to obtain an over-all spectral bandwidth of 0.013 Å with moderate light-gathering power. A multilayer dielectric reflective coating is used for atomic absorption measurements with a continuum source in the 3200 to 3600 Å region. Results for Cu and Ag show that sensitivities obtained are the same as those obtained with line sources. Profiles of the 3247 Å copper and 3383 Å silver resonance lines were obtained, and the half-widths reported.
Quantitative Elemental Analysis of Art Objects by Energy-Dispersive X-ray Fluorescence Spectroscopy
Authors: Hanson Victor F.
Published: September 2005

Techniques have been developed for the analysis of glass and metal objects for up to 35 elements in a few minutes for aiding the curator in determining the authenticity of many museum objects. No samples are removed nor are the objects altered by the measurements. Trace elements present as impurities in older pieces and absent in modern forgeries as well as the major constituents can be measured with accuracies at least as high as wet chemical and spectrographic methods generally employed in museum laboratories. Tables of instrument response to 71 elements presented together with empirical corrections for matrix effects permit direct calculations of weight percentages within 20% of all the elements present. Employment of reference standards and the use of the principal element as an “internal standard” improve this accuracy to better than 1% of the major elements present. Charts of “peak heights” of the various spectral lines of each element plotted as a function of energy permit a rapid determination of the most probable elements that are present in a spectrum. It also aids in selecting peaks that are free of interference from other elements. Tables of peak heights and energies of the peaks of 71 elements listed in order of atomic number indicate where the spectral peaks of the various elements will be found and what their relative intensity is. Procedures are described for determining weight percent of 15 or more elements in metal and 30 or more in glass objects from spectral data. Examples of analytical results are given for typical museum objects and specially prepared samples.
V, Cr, Mn, Fe, and Ni in TiO2: Determination by Peak Switching Spark-Source Mass Spectroscopy
Authors: Beveridge Richard L.
Published: September 2005

Spark-source mass spectrometry using the peak switching mode of electrical detection has been used for the quantitative analysis of V, Cr, Mn, Fe, and Ni in titanium dioxide pigments. Standards of differing histories form linear calibration curves down to 0.4 ppm when a source coldfinger was used to condense hydrocarbon species. An over-all relative standard deviation of 12.7% was obtained for V, Cr, Mn, Fe, and Ni in the TiO2 standards.
Raman Spectroscopy of Some Polymers and Copolymers of Styrene, Butadiene, and Methylmethacrylate
Authors: Sloane Howard J. , Bramston-Cook Randall
Published: September 2005

The application of Raman spectroscopy to polymeric systems is discussed. Experimental factors, including sample preparation, are reviewed. In particular, a three-component polymer is quantitatively analyzed, and Raman methods are shown to yield information not available from infrared alone.
The Determination of Calcium, Magnesium, Copper, and Iron in Airborne Particulates over the Chicago Metropolitan Area
Authors: Hoschler Margaret E. , Kanabrocki E. L. , Moore Carl E. , Hattori Donald M.
Published: September 2005

Samples of air particulates were collected at 21 sampling stations in Chicago and a northern suburb, on 4 April 1968. These samples were analyzed for Ca, Mg, Fe, and Cu by atomic absorption spectroscopy, and the data collected were compared to similar air pollution studies in several other widely scattered parts of the world.
A New Dual Wave-Length Spectrophotometer
Authors: Woodriff Ray , Shrader Douglas
Published: September 2005

The design, construction, specifications, and operation of a new dual wave-length spectrophotometer are presented. The instrument utilizes only one fixed grating and mobile exit slits with photomultiplier light sensors. Two wave lengths can be monitored and both channels may be scanned, simultaneously and independently. The spectrophotometer has been integrated into an atomic absorption system which includes a Woodriff furnace and Ithaco dual channel lock-in amplifier. The two channels may be used separately (A and B) or may be ratioed (A/B). Calibration curves were obtained for Ag and Pb. Results are given for the determination of Ag in a complex water sample requiring background correction using the ratio (A/B) mode and for the simultaneous determination of Ag and Pb in synthetic samples using the two separate channel (A and B) mode.
The Determination of All Detectable Elements in the Aquatic Plants of Linsley Pond and Cedar Lake (North Branford, Connecticut) by X-Ray Emission and Optical Emission Spectroscopy
Authors: Cowgill Ursula M.
Published: September 2005

A method, employing optical and x-ray emission, is described for the determination of all detectable elements in aquatic plants growing in the littoral zone of two lakes in Connecticut. The pondweed and the hornwort accumulate As. Comparative data are presented for the determination of this element by atomic absorption and x-ray emission. The chemical composition of some plants is shown as well as the distribution of the rare earths in various portions of the yellow water lily.
Effect of Medium on the Intensity of Infrared Absorption Bands
Authors: Nasser M. I.
Published: September 2005

The paper presents an extensive study of the solvent effect upon the intensity of ir absorption bands. Because of the special importance of the (X—H) bonds =C, O, H), this study is restricted to the (N—H) and the (O—H) bonds of diphenylamine and α-naphthol, respectively. An easy way to calculate the integrated intensity directly from the record chart, saving much time and effort and avoiding a source of appreciable error, has been developed. The determination of the intensity in the gas phase ( Ag) is difficult. An extrapolation method for determining ( Ag) is presented. The values found are:

[Formula: see text]

It is also found that the absolute solvent interactions play an important role in the intensity variation.
A Quantitative Method for Infrared Spectroscopy of Surface Species
Authors: Ahmed A. , Gallei E.
Published: September 2005

A quantitative method for studying surface species by infrared spectroscopy has been described. The solid particles are not subjected to high pressures or contacted with any extraneous substance during sample preparation. The method is quantified by using the solid substrate as an internal standard. Reproducibility measurements on surface concentration of trimethylchlorosilane adsorbed on silica gel and Aerosil gave 3.29 and 3.49% standard errors, respectively. Quantitative measurement of surface hydroxyl groups in open systems is also described.
Synthetic Sulfide Standards for Quantitative Emission Spectrographic Analysis
Authors: Mays R. E. , Czamanske G. K. , Heropoulos Chris
Published: September 2005

An emission spectrographic method for the determination of minor elements occurring in natural sulfides has been developed. This method involves the use of complex crystalline standards, synthesized at elevated temperatures, that contain within their lattices the minor elements of interest. Results of the present study are based on the incorporation of Cd, Co, In, Mn, and Ni into a ZnS base and of Ag, As, Bi, Cd, Hg, Sb, Se, and Te in part into each of two portions of a PbS base. The procedure used for the synthesis is that commonly employed for such studies, that is, reaction at elevated temperatures (300 to 1000°C) within evacuated silica tubes. Comparison of analytical curves generated by these standards with curves based on oxide standards shows that erroneously high values may be obtained when oxide standards are used. This error is especially evident for cadmium. Results for minor elements in sulfide minerals by this method agree with results obtained by other methods.
Atomization Chambers for Atomic Absorption Spectrochemical Analysis: A Review
Authors: Woodriff Ray
Published: September 2005

Four types of atomization chambers for atomic absorption are reviewed. Advantages and disadvantages of each are considered. The effects of chamber dimensions and sample introduction system are considered in relation to accuracy, sensitivity, and convenience. Relative sensitivity is more significant for real samples than absolute sensitivity. When peak heights are measured, the relative sensitivity is proportional to the atomizer chamber length. When peak area is measured, the relative sensitivity is proportional to the third power of the atomizer chamber length.

Matrix materials in general affect the accuracy of determinations by changing the rate or time of atomization. Matrix effects are less serious with long tight tubes than they are for tubes with openings near the center.
A New Method for Homogenizing Powder Mixtures and One Solution to the Problem of Variable Matrices Commonly Found in Lake Muds
Authors: Cowgill Ursula M.
Published: September 2005

A new method is described, employing acetone and a sonicator, for the procurement of a homogeneous mixture of lake mud and graphite suitable for optical emission analysis. The effects of variable matrices are masked by use of a mixture of 2 parts graphite to 1 part CaF2. The elements studied in these variable matrices were Be, Hg, Bi, Sn, Co, B, Na, Mo, V, Ag, Li, and Cd. The percent standard deviations obtained on replicate analyses are extremely small.
Nuclear Magnetic Resonance Studies of Ethyl N-Substituted Carbamates
Authors: Soignet D. M. , Boudreaux G. J. , Berni R. J. , Benerito R. R.
Published: September 2005

Nuclear magnetic resonance studies showed that ethyl N-substituted carbamates are present as single isomers in either deuterated chloroform or dimethylsulfoxide solvents. The thioncarbamates exist as cis-trans isomer mixtures. The polar and resonance character of the substituent affects the shielding and thus the chemical shift of the amide proton.
Measuring Line Centers from Digitally Recorded Spectra Using a Minicomputer
Authors: Hurlock S. C. , Hanratty J. R.
Published: September 2005

A system is described for determining spectral positions from high resolution infrared spectra which have been recorded in digital form on magnetic tape. The system employs a minicomputer located in the laboratory and line centers are determined by an interactive procedure in which the operator makes judgments based on information displayed on the CRT screen of the computer. This information consists of the spectrum, a reflection of a local section of the spectrum at a vertical line through the center of the screen, a plot of the difference between the spectrum and its reflection, and the square of the area under the difference curve. Very high accuracy is demonstrated for locating the centers of single lines as well as the centers of the components of incompletely resolved double lines. Determinations of spectral positions (wavenumber calibration) parallel operations that were previously performed as batch jobs by a much larger computer. Spectral positions are determined by standard methods of calibration of interference fringes and interpolation.
The Physical Basis for Analysis of the Depth of Absorbing Species Using Internal Reflection Spectroscopy
Authors: Tompkins Harland G.
Published: September 2005

Internal reflection spectroscopy is discussed for a nonuniform distribution of an absorbing species. Although some distributions cannot experimentally be distinguished from others, if one assumes a distribution, information about depth and concentration can be obtained by making measurements at several angles of incidence. A practical method is proposed and demonstrated for obtaining thickness and concentration for an assumed step profile.
Application of X-ray Photoelectron Spectroscopy to the Study of Fiberglass Surfaces
Authors: Nichols Gary D. , Hercules David M. , Peek Roy C. , Vaughan Dennis J.
Published: September 2005

The application of x-ray photoelectron spectroscopy (ESCA) to the study of fiberglass surfaces is reported. Qualitatively, ESCA has been used to show the change in concentration of elements at the surface when fiberglass is subjected to heat and/or acid treatment. Diffusion of calcium to the surface as a function of temperature has been studied. Similarly, leaching of aluminum by acid as a function of pH is reported. The ability of ESCA to detect organic functional groups attached to fiberglass surfaces has been demonstrated for nitrogen and sulfur. Fiberglass coated with organic groups having chelating properties has been shown to extract metals from solution. It has also been demonstrated that ESCA can follow reactions of organic functional groups on glass surfaces, namely sulfonation of an amine.
A New Radio-Frequency Electrodeless Discharge Cell for Studying the Emission Spectra of Organic Molecules
Authors: Runser Dennis J. , Frank C. W.
Published: September 2005

A radio-frequency electrodeless discharge cell for studying the emission spectra of organic molecules is described. This medium pressure source is stable and reproducible with and without sampling it is also self-initiating. Pressure, power, and flow rate studies as well as “gas temperature” measurements were made. Low and medium resolution spectra of aromatic and nonaromatic chlorinated hydrocarbons and chlorinated pesticides are discussed. A qualitative internal wavelength standard is also described.
Sputtering Studies Using the Matrix Isolation Technique
Authors: Green David W. , Gruen Dieter M. , Schreiner Felix , Lerner Jerome L.
Published: September 2005

The application of the matrix isolation technique to the study of the sputtering process is reported. Equations are derived which relate the experimentally measured absorbance data to the sputtering yield. These equations are applied to data from the sputtering of Nb metal by 50 keV rare gas ions. Relative sputtering yields obtained in this manner are in good agreement with sputtering yields obtained by weight loss measurements. The potential of the technique for studies of both physical and chemical sputtering and for the determination of oscillator strengths is discussed.
A Method for Analysis of Plant Tissue by Direct Reading Spark Emission Spectroscopy
Authors: Chaplin M. H. , Dixon A. R.
Published: September 2005

A procedure was developed for the rapid quantitative determination of K, P, Ca, Mg, Mn, Fe, Cu, B, and Zn content in plant tissue by direct reading emission spectrometry using spark excitation and the rotating disc electrode technique. Aliquots of standard reference material, ground to pass a 40 mesh screen, are weighed into high form porcelain crucibles and ashed at 450°C for 6 h. Five milliliters of an internal standard-buffer solution (0.2% cobalt and 0.5% lithium in 1 N HCl) are added to the remaining ash. The resulting solution is subjected to a 30-sec burn on the spectrometer, and the intensity ratios for each element are recorded. Known concentrations ( X) and intensity ratio units ( Y) are entered into a stepwise regression computer program, and the linear, quadratic, and cubic regressions of Y on X are determined. Sample values are entered as Y into the appropriate regression equation which is then solved for X. If quadratic or cubic regression equations are used, the program will select the appropriate root. Relative standard deviations for samples determined over a several-day period generally were less than 10%.
An Examination of the Uniqueness of Gaussian and Lorentzian Profiles
Authors: Baruya A. , Maddams W. F.
Published: September 2005

The conditions under which Gaussian and Lorentzian peaks may meaningfully be fitted in terms of two subcomponent bands have been examined. It is shown that good fits are possible for a wide range of relative intensities and half-widths, given that the separation of the two component peaks is limited. In the case of the Lorentzian profile, of particular interest because infrared and Raman bands approximate to this shape, fits significantly better than the limit imposed by experimental errors are obtained for separation less than about 40% of the half-width. The practical implications of these results for the curve fitting of overlapping peaks are considered; in most practical situations Gaussian and Lorentzian profiles are unique and curve fitting may be undertaken.
High Temperature Infrared Spectroscopy of Adsorbed Species during Catalytic Reaction
Authors: Amenomiya Y.
Published: September 2005

A reaction system and a high temperature cell have been developed for the infrared spectroscopy of surface species during catalytic reaction. The reaction system was a closed circulation apparatus operated by a bellows pump, and the temperature of catalyst in the cell could be varied over a wide range from —195 to 700°C. Thus, formate ion was detected on an alumina catalyst during the water gas shift reaction between 300 and 500°C. Also, the combination of the infrared spectroscopy with the temperature-programed desorption of adsorbed species made it possible to measure the amount of the formate ion on the catalyst.
A Computer-Controlled Photon Counting Spectrometer for Rapidly Scanning Low Light Level Spectra
Authors: Niemczyk T. M. , Ettinger D. G.
Published: September 2005

A method of optimizing the scan time of a spectrometer based on the signal level is discussed and its implementation in a computer-controlled photon counting spectrometer is presented. Previous implementations of signal-dependent methods have been useful when the spectra being measured contain only regions where a measurable signal exists. This problem has been eliminated by taking advantage of the ability of the computer to make a decision. Data are presented showing how the use of an “intelligent” instrument, such as that described here, can increase the efficiency of any experiment.
Internal Reflectance Spectroscopy of Reacted Surfaces: Fluorinated Polyethylene and Polypropylene
Authors: Blackwell C. S. , Degen P. J. , Osterholtz F. D.
Published: September 2005

The measurement of the depth of reaction of F2 into the surface of polyethylene and polypropylene is reported. The roughness of the reacted surface has required the development of a novel three-layer, coated sample and subsequent theoretical analysis and analytical techniques. The results with polypropylene can be confirmed by visible reflectance fringes; however, in polyethylene the three-layer method is, at present, the only easy way to measure the extent of fluorine modification of the polymer surface. The extent of fluorination was found to be proportional to the time of exposure to F2 gas and to increase with elevation of the sample temperature.
Microprocessor-Controlled Data Acquisition System for Pulsed Laser Spectroscopy
Authors: Ritz G. Patrick , Wallan David J. , Morris Michael D.
Published: September 2005

Pulsed laser systems produce spectroscopic signals with large shot-to-shot variations, short durations, and low duty cycles. The most satisfactory signal processing system is gated integration, with pulse averaging and ratioing to a reference signal. We describe a system based on commercially available modular integrators and a hobbyist microcomputer which performs the averaging and ratioing digitally. System performance is equal to or better than that of fully analog systems, while the cost is low and construction is straightforward.
Noise Amplification and Resolution Improvement in Deconvolution of Experimental Spectra
Authors: Balslev I. , Larsen J. E. , Larsen S.
Published: September 2005

Digital deconvolution of instrumentally broadened spectra is characterized by an improvement of resolution and an amplification of noise. By noise simulation we have studied the relation between these properties when the deconvolution interval is bounded by regions with negligible influence of instrumental broadening. These boundary conditions lead to a relevant reduction of noise amplification for rectangular and triangular convolution functions, but have less practical interest for bell-shaped convolution functions.
Absorbance Compensation Technique in the Analytical Laboratory
Authors: Manocha A. S. , Montgomery R. M.
Published: September 2005

Modern Fourier transform infrared instruments, which are designed around a laser calibrated wavelength determination, make it possible to obtain high quality absorbance subtracted infrared spectra. This technique coupled with solvent variations can provide unambiguous characterization of mixtures. The use of the absorbance subtraction procedure in identification, comparison (quality control), and surface effects is illustrated by several examples.
A New, Accurate Method for the Measurement of Rise Velocities in Laminar Flames
Authors: Boss Charles B. , Hieftje Gary M.
Published: September 2005

A novel technique is introduced for the measurement of rise velocities of hot, laminar flames. The new technique is straightforward to implement, rapid to employ, and more accurate than previous methods based on the observation of moving heated particles. In the method, tiny individual droplets of a solution containing alkali or alkaline earth elements are repetitively introduced into the flame to be examined. The small cloud of atomic vapor which is produced upon atomization of a droplet is then monitored photometrically as it passes two well-defined points in the flame. Knowledge of the distance between the points and measurement of the time required for the atoms to traverse it thus enables the flame velocity to be calculated. Conveniently, velocity measurements with this technique are localized in the flame, thereby permitting spatial variations in flame velocity to be examined. Moreover, the negligible mass of the moving, measured atom cloud eliminates error otherwise caused by gravitational attraction and its decelerating effect. The utility of this new technique is demonstrated through the measurement of localized velocities in a laminar, air-acetylene flame.
Optimization of Pulsing Conditions for Hollow Cathode Lamps for Atomic Fluorescence Spectrometry
Authors: Wolfe Terry C. , Vickers Thomas J.
Published: September 2005

The effect of pulsing conditions on hollow cathode lamp output, on the intensity of atomic fluorescence excited, and on atomic fluorescence detection limits has been examined for a number of commercial sealed lamps. Optimization must be carried out on an individual lamp basis. Maximum integrated intensity is obtained by minimizing the dc current through the lamp and making the duty factor as large as possible within the limit set by the maximum allowed average current through the lamp. Integrated intensity is largely independent of pulse width and depends only to a small extent on peak current. For the range of operating conditions considered in this study, the effect on atomic fluorescence of line broadening due to pulsing at high peak currents was small.
Measurement of Electron Temperatures in the Hollow Cathode Discharge
Authors: Mehs D. M. , Niemczyk T. M.
Published: September 2005

A system has been designed which will rapidly and conveniently measure the electron temperature in a hollow cathode discharge. The measurement system is based on the floating double probe technique. Preliminary results obtained with this system indicate that the electron temperature depends on lamp current, fill gas pressure, and cathode material. These results are compared to those found in the literature for low pressure, microwave, and radiofrequency discharges. The electron temperatures measured in the three types of discharges have similar values, but the different discharges show strikingly different dependences on plasma composition.