bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhetoric versus Reality
Authors: Caprioli Mary , Trumbore Peter F.
Published: September 2005

The term rogue statehas become part of the common language of American foreign policy, and the assumptions made by policy makers about the international conduct of these actors—that they represent aggressive threats to international peace and security—have become entrenched at the center of U.S. foreign and defense policies. The central assumption of rogue state aggressiveness, however, has not been empirically tested. This project fills that gap. The authors first identify those states that, since 1980, have consistently been described as rogues by policy makers, as well as other states that evince the objective characteristics said to qualify a state for rogue status. Whenthe authors examine these states'interstate conflict behavior as a group, they find that they are no more likely to become involved in militarized interstate disputes, no more likely to initiate militarized action, and no more likely to use force first than nonrogue states.
The Roles of Personality and Self-Defeating Behaviors in Self-Management Failure
Authors: Renn Robert W. , Allen David G. , Fedor Donald B. , Davis Walter D.
Published: September 2005

This article proposes an individual-level theoretical framework of self-management failure. First, the authors introduce six self-defeating behaviors (SDBs) to the organizational literature. Second, they explain how personality may predispose employees to engage in these SDBs. Third, they define self-management failure and analyze how each SDB can undermine standard setting, operating, and monitoring. Throughout their presentation of the framework, the authors offer several research propositions. Finally, they discuss both the practical and theoretical implications of the framework.
The Lack of Consensus About Strategic Consensus: Advancing Theory and Research
Authors: Kellermanns Franz W. , Walter Jorge , Lechner Christoph , Floyd Steven W.
Published: September 2005

The purpose of this article is to describe the theoretical and methodological reasons for the inconsistent findings on the value of strategic consensus. This analysis suggests the need for (a) definitions of consensus that align the locus and content of agreement with the study context and theoretical premises; (b) measures of consensus that take account of locus as well as differences in how the content of strategy is perceived by top-, middle-, and lower-level managers; (c) research designs wherein assumptions about the locus and content of consensus govern the choice of antecedents; and (d) more consistent use of moderators.
Active Vision in Parietal and Extrastriate Cortex
Authors: Merriam Elisha P. , Colby Carol L.
Published: September 2005

Vision is an active process. We do not see the world directly; rather, we construct a representation of it from sensory inputs in combination with internal, nonvisual signals. In the case of spatial perception, our representation of the visual scene must take into account our own movements. This allows us to perceive the world as stationary despite the constant eye movements that produce new images on the retina. How is this perceptual stability achieved? Our central hypothesis is that a corollary discharge of the eye movement command updates, or remaps, an internal representation when the eyes move. In support of this hypothesis, the authors review evidence that parietal cortex and extrastriate visual areas in both monkeys and humans participate in spatial updating. These findings shed new light on the neural circuitry involved in producing a stable and coherent perception of visual space.
Synapse-Glia Interactions at the Vertebrate Neuromuscular Junction
Authors: Feng Zhihua , Koirala Samir , Ko Chien-Ping
Published: September 2005

Glial cells are widely distributed throughout the nervous system, including at the chemical synapse. However, our knowledge of the role of glial cells at the synapse is rudimentary. Recent studies using a model synapse, the vertebrate neuromuscular junction (NMJ), have demonstrated that perisynaptic Schwann cells (PSCs), which are the glia juxtaposed to the nerve terminal at the NMJ, play active and essential roles in synaptic function, maintenance, and development. PSCs can respond to nerve activity by increasing intracellular calcium and are capable of modulating synaptic function in response to pharmacological manipulations. Studies using PSC ablation in vivo have shown that PSCs are essential for the long-term maintenance of synaptic structure and function at the adult NMJ. In vivo observations have also shown that PSCs guide presynaptic nerve terminal extension and dictate the pattern of innervation during synaptic regeneration and remodeling at adult NMJs. PSCs may also induce postsynaptic acetylcholine receptor aggregation. Furthermore, PSCs play an essential role in synaptic growth and maintenance during development of NMJs in vivo, and Schwann cell-derived factors can promote synaptogenesis and enhance synaptic transmission in tissue culture. These recent findings advance the emerging concept that glial cells help make bigger, stronger, and more stable synapses.
Psychostimulants, L-type Calcium Channels, Kinases, and Phosphatases
Authors: Rajadhyaksha Anjali M. , Kosofsky Barry E.
Published: September 2005

There is growing evidence for the role of voltage-gated L-type Ca2+ channels in mediating aspects of the addictive properties of psychostimulants. L-type Ca2+ channels activate Ca2+ second-messenger pathways that regulate protein phosphorylation and thereby activation of target gene expression. Here the authors will review recent progress in our understanding of L-type Ca2+ channel-activated signal transduction pathways that contribute to molecular neuroadaptations evident following acute and chronic exposures to psychostimulants.
Presenilins in the Developing, Adult, and Aging Cerebral Cortex
Authors: Wines-Samuelson Mary , Shen Jie
Published: September 2005

Mutations in presenilins are the major cause of familial Alzheimer disease. The involvement of presenilins in the pathogenesis of Alzheimer disease, therefore, has been the subject of intense investigation during the past decade. Genetic analysis of phenotypes associated with presenilin mutations in invertebrate and vertebrate systems has greatly advanced our understanding of the in vivo functions of presenilins. In this review, the authors will summarize the current understanding of presenilin function, with an emphasis on the mammalian cerebral cortex. During development, presenilins play crucial roles in the maintenance of neural progenitor cell proliferation, the temporal control of neuronal differentiation, the survival of Cajal-Retzius neurons, and proper neuronal migration in the developing cerebral cortex. Analysis of presenilin function in the adult cerebral cortex has revealed essential roles for presenilins in synaptic plasticity, long-term memory, and neuronal survival. The authors will also discuss the molecular mechanisms through which presenilins may mediate these functions, including the Notch, CREB, and NMDA receptor-mediated signaling pathways. These diverse functions of presenilins in cortical development and function and neuronal survival have important implications for the pathogenesis of neurodegenerative dementia.
Why We Like to Call Ourselves Latinas
Authors: González Christina , Gándara Patricia
Published: September 2005

This article discusses the complex and subtle reasons why many people of Spanish-speaking ancestry—both Latin Americans and Spaniards—like to call themselves “Latinos.” Among other things, this word, coined by the Mediterranean countries to resist Anglo dominance in the 19th century, is currently being used by people of Spanish-speaking ancestry in the United States to express ethnic pride. Thus, the choice of the term “Latinos” over “Hispanics” moves the focus from a pan-ethnic, historical identity to contemporary struggles for equality and the racialization of people of Spanish-speaking ancestry in the United States.
Race-Related Stress and Sociocultural Orientation Among Latino Students During Their Transition Into a Predominately White, Highly Selective Institution
Authors: Lopez J. Derek
Published: September 2005

This longitudinal study examines minority status stress and socio-cultural orientation among Latino freshmen as they enter a predominately White, elite, private institution. The study finds Latino freshmen report experiencing racism. Students respond to racism by developing an alienated sociocultural orientation and beginning to see their Latino peers as a source of support.
To change or not to change: investigating the value of MCQ answer changing for Gulf Arab students
Authors: Al-Hamly Mashael , Coombe Christine
Published: September 2005

This study investigates whether the practice of answer changing on multiple-choice questions (MCQs) is beneficial to Gulf Arab students’ overall test performance. The proficiency exam used in this study is the Michigan English Language Institute College English Test - Grammar, Cloze, Vocabulary, Reading (MELICET-GCVR), which was developed using retired forms of the Michigan English Language Assessment Battery (MELAB). This exam was administered to 286 students at Kuwait University and Dubai Men’s College, Higher Colleges of Technology. Findings suggest that we should encourage students to change answers judiciously after they have scrutinized their original answers for more plausible alternatives. Most important, students should not be influenced by traditional perceptions that incorrectly malign answer changing. The effect of item difficulty as well as its impact on answer changing is also reported. Finally, information on the efficacy of one specific objective test strategy, that of changing answers, is disseminated.
A case with epilepsy, cognitive impairment, renal microangiopathy and high titres of anticentromere and anticardiolipin antibodies
Authors: Serelis J , Tektonidou M G , Skopouli F N
Published: September 2005

We report a case with epileptic seizures, cognitive dysfunction, livedo reticularis, renal microangiopathy, acute myocardial infarction and high titres of anticentromere antibodies (ACA) and IgG/IgM anticardiolipin antibodies. This is a rare association between primary antiphospholipid syndrome and ACA positivity that has not been reported so far in the literature.
Seronegative systemic lupus erythematosus: etiology of nephrotic syndrome and acute renal failure in early postpartum period
Authors: Ozdemir F N , Elsurer R , Akcay A , Ozdemir B H , Sezer S , Kuscu E , Haberal M
Published: September 2005

Systemic lupus erythematosus (SLE) is an autoimmune syndrome that occurs most commonly in women during their reproductive years. Nephritis is known to be one of the most serious complications of SLE. Lupus nephropathy is frequently associated with ANA and anti-dsDNA antibodies. Rarely, serological markers may be initially absent, and in many cases, they become positive after sometime.

We present a 28-year old, otherwise healthy female who admitted to our clinic with edema, hypertension, proteinuria and acute renal failure following her fourth delivery. Serum immunological markers were negative and renal biopsy showed histopathological changes consistent with systemic lupus erythematosus as the etiology of nephrotic syndrome. A dramatic therapeutic response was achieved by pulse steroid and cyclophosphamide treatment following oral steroid therapy.

In women with new onset nephrotic syndrome or renal function deterioration in postpartum period, even if the patient is asymptomatic or seronegative, it is crucial to exclude SLE for a rapid diagnosis and prompt treatment in the case of lupus nephritis. Renal biopsy is of diagnostic importance in such cases in which there is no other clinical, biochemical and serological evidence of the disease.
Anti-ribosomal P-protein and its role in psychiatric manifestations of systemic lupus erythematosus: myth or reality?
Authors: Ebert T , Chapman J , Shoenfeld Y
Published: September 2005

Systemic lupus erythematosus (SLE) is an autoimmune disease that may involve the central nervous system (CNS) resulting in neuropsychiatric manifestations. The associated psychiatric disorders include depression, psychosis, mood disorders, anxiety, cognitive dysfunction, and delirium/encephalopathy. Several autoantibodies may play a role in the pathogenesis of psychiatric complications of SLE, particularly antibodies against ribosomal P-proteins (anti-P) and possibly antibodies against endothelial cells (AECA). The reported prevalence of anti-P is highly variable in SLE patients and is dependent on different ethnic backgrounds, sensitivity and specificity of the assays employed for autoantibody detection, and the time at which sera were analysed in relation to the clinical event. Controversial data exist on the association of anti-P with psychiatric manifestations of SLE. These autoantibodies have been suggested to be specific markers of the psychiatric manifestations of SLE, particularly of the psychosis and depression, and the antibody level varied with the clinical activity of the disease. Some studies have confirmed the hypothesis of an association of anti-P antibodies with psychiatric manifestations of neuropsychiatric SLE (NPSLE) while others have disputed this relationship. This review summarizes the recent studies about relationship between anti-P antibodies and psychiatric manifestation of SLE.
Cyclophosphamide for lupus during pregnancy
Authors: Clowse M EB , Magder L , Petri M
Published: September 2005

Severe systemic lupus erythematosus often requires the use of cyclophosphamide in women of reproductive age. As cyclophosphamide is generally avoided during pregnancy because of its teratogenic risk, its impact on fetal survival is poorly understood. This is a case series of lupus patients exposed to cyclophosphamide during pregnancy. We reviewed pregnancies in patients with lupus seen at a large university hospital between October 1986 and September 2003. The pregnancies were evaluated prospectively for cyclophosphamide exposure, lupus activity, and fetal outcome. Comparison was made between pregnancies with severe lupus requiring cyclophosphamide and those that did not. We identified four pregnancies with cyclophosphamide exposure. Two pregnancies were inadvertently exposed to cyclophosphamide early in the first trimester; both resulted in first trimester miscarriages. Two patients were administered cyclophosphamide for severe lupus nephritis and thrombocytopenia during the second trimester. Soon after the administration of cyclophosphamide, both pregnancies ended with fetal demise. Pregnancies exposed to cyclophosphamide for severe lupus flare resulted in a higher rate of fetal losses than pregnancies with severe lupus but not requiring the drug (100% versus 31.25%). In conclusion we present four pregnancies exposed to cyclphosphamide, each ending with pregnancy loss. Based on our experience, the survival of the fetus is strongly in doubt when cyclophosphamide is required to treat lupus in the mother.
Modulation of intra-pulmonary TGF-b expression by mycophenolate mofetil in lupus prone MRL/lpr mice
Authors: Guo H , Leung J CK , Chan L YY , Lui S L , Tsang A WL , Lai K N
Published: September 2005

We investigated the expression profile of inflammatory cytokines in the lung of lupus-prone MRL/lpr mice and evaluated the therapeutic potential of mycophenolate mofetil (MMF) in reducing pulmonary cytokines in active lupus. Eight-week old female MRL/lpr mice ( n = 20) were treated with MMF in vehicle by oral gavage. Disease control MRL/lpr mice ( n = 30) or normal control MRL mice ( n = 20) received vehicle alone. The mice were sacrificed after eight or 12 weeks of treatment. Gene expression and protein synthesis of IL-1β, MCP-1 and TGF-β1 in lung tissues were determined. We found an increase in the gene expression of IL-1β, MCP-1 and TGF-β1 in lung tissues of untreated MRL/lpr mice compared with MRL mice at either 16 weeks or 20 weeks of age. MMF treatment significantly prolonged the survival of MRL/lpr mice, down-regulated the gene expression of IL-1β, MCP-1 and TGF-β1 in lung tissues at the end of eight or 12 weeks of treatment. Protein synthesis of TGF-b1 was decreased following eight weeks of MMF treatment. We conclude that MMF treatment can reduce the TGF-b1 gene expression and protein synthesis in lung tissues of lupus-prone mice. Our findings provide experimental data suggesting a beneficial potential of MMF therapy in pulmonary involvement of lupus.
A Novel Route to the Synthesis of α-Arylselenosubstituted Carbonyl Compounds and Nitriles
Authors: Beletskaya Irina , Sigeev Alexander , Peregudov Alexander , Petrovskii Pavel
Published: September 2005

Activated alkyl halides such as α-halocarbonyl compounds and α-halonitriles easily react with tributyltin arylselenides both in fluoride-mediated reaction and without any additives. The former protocol gives corresponding selenides under the mild conditions in near quantitative yields.
Generalization of the Projection Space Improves the SAC-SD (symmetry-adapted cluster-singles and doubles) Method in Bond-breaking Systems
Authors: Hasegawa Jun-ya , Nakatsuji Hiroshi
Published: September 2005

The equation for nonvariational SAC-SD method has been generalized to have multireference projection space. The results show significant improvements in the description of the potential curves especially in the bond-breaking region.
Nonphotochemical Synthesis of a Base-free Silyl(silylene)iron Complex and Its Reaction with CO: Another Direct Evidence for Reversible 1,2- and 1,3-Group Migrations
Authors: Hashimoto Hisako , Matsuda Akihisa , Tobita Hiromi
Published: September 2005

A base-free silyl(silylene)iron complex 1, which had been originally synthesized by a photochemical method, was prepared in higher yield by a newly developed thermal method. Reaction of this silyl(silylene)iron complex 1 with CO at 80 °C cleanly produced a mixture of two isomeric disilanyliron complexes 6 and 6′ via 1,3-group migrations followed by 1,2-silyl migration. Oppositely, each of disilanyl complexes 6 and 6′ reproduced the silyl(silylene)iron complex 1 with a release of CO almost quantitatively at room temperature by irradiation with a fluorescent lamp.
The Cactus-like Organic-grafted Silica Balls as the Supporter of TiO2 Photocatalyst
Authors: Xu Yao , Cui Yanxia , Wu Dong , Sun Yu Han
Published: September 2005

Cactus-like organic-grafted silica balls synthesized by m-XDI, APTES, and PDMS was used as supporter of anatase TiO2 to improve the separation of TiO2 photocatalyst.
Estimating kidney function in adults using formulae
Authors: Lamb Edmund J , Tomson Charles RV , Roderick Paul J
Published: September 2005

With increasing emphasis on the earlier detection and management of chronic kidney disease (CKD), estimation of the glomerular filtration rate (GFR) has assumed greater importance. It is accepted that use of serum creatinine concentration alone as a marker of kidney function is inadequate; in particular, it has a poor sensitivity for detecting CKD. International recommendations favour the reporting of creatinine-based estimates of GFR using formulae which also take into account age, gender and other variables that affect the relationship between serum creatinine and GFR: in particular, the four-variable formula derived from the Modification of Diet in Renal Disease study (4-v MDRD) is increasingly being used. We have reviewed the literature supporting the use of this formula compared with the well-established Cockcroft and Gault formula. Overall, evidence supports the use of the 4-v MDRD formula as an improved estimate of GFR in people with moderate/advanced CKD. Neither formula performs well in people with normal and mildly reduced kidney function. However, there remain significant problems with this approach and areas where further research is required. In particular, the widespread adoption of estimated GFR reporting has refocused attention on the limitations of creatinine measurement and highlighted clinical situations in which the formulae are inadequate.
A review of troponin assay performance in Wales: can the same (method-dependent) decision limits be used in different sites?
Authors: Thomas MA , Singh GK , Williams EJ , McDowell IFW , Tovey JA , Wayte AMO
Published: September 2005

An audit of troponin measurement protocols in use in Wales showed significant variations in practice with no consensus on analytical methods, or in the selection of a decision limit for the diagnosis of myocardial damage. Peer review data on assay imprecision at concentrations approaching the analytical limit of detection are lacking. The objective of the study was to establish clinically relevant precision profiles for the troponin methods used throughout Wales, which could be used to develop a standardized approach to the selection of a decision limit. A series of five pools of human serum spiked with troponin I-T complex were prepared and stored at -7°C until despatch. Five sets of each pool were dispatched to all Welsh laboratories and stored at -20°C until analysis. The analysis protocol consisted of two replicates of each pool per batch, and two batches per day for five days ( n=20). All the laboratories performed all the measurements in the same week. The lowest concentration providing a 10% coefficient of variation (CV) was 0.02 µg/L for the Roche method and 0.11 µg/L for the Beckman AccuTnI. The lowest concentrations that could be distinguishable from the 99th percentile reference limit were 0.02 µg/L for the Roche method and 0.07 µg/L for the Beckman AccuTnI. Current methods do not achieve the 10% CV at the 99th percentile reference limit proposed by the European Society of Cardiology. Use of the lowest concentration that can be reliably distinguished from the 99th percentile reference limit offers a novel alternative decision limit, which provides a slightly lower concentration than at the 10% CV but maintaining confidence in the assay that false-positive rates will be minimized.
Drug-induced acute autoimmune hepatitis during combination therapy with atorvastatin and ezetimibe
Authors: van Heyningen Charles
Published: September 2005

A case is presented of a patient who developed acute hepatitis during cholesterol-lowering treatment with atorvastatin and ezetimibe. Further investigations reveal a probable drug-induced autoimmune hepatitis, and ezetimibe is considered to be the most likely causal agent. This case is the first report of an autoimmune hepatitis associated with ezetimibe therapy.
Alternative Conditions for a Well-Behaved Travel Time Model
Authors: Carey Malachy , Ge Y. E.
Published: September 2005

The travel time τ(t) on a link has often been treated in dynamic traffic assignment (DTA) as a function of the number of vehicles x(t) on the link, that is, τ(t) = f(x(t)). In earlier papers, bounds on the gradient of this travel time function f(x) have been introduced to ensure that the model, and in particular the exit times and outflows, have various desirable properties, including a first-in-first-out (FIFO) property. These gradient conditions can be restrictive, because most commonly used travel time functions do not satisfy the conditions for all inflow rates. However, in this paper we extend the earlier results to show that the same properties (including FIFO) can be achieved by instead assuming f(x) is convex, convex about a point, or has certain weaker properties that are satisfied by most travel time functions f(x) proposed or used in practice. These results hold under the conditions in which the travel time function τ(t) = f(x(t)) has generally been applied in the DTA literature, that is, with each link being homogeneous (uniform capacity along the link) and without obstructions or traffic lights. In that case, even if f(x) does not satisfy the above gradient condition, the range in which it is violated is not attainable and hence cannot cause a problem.
Multiobjective Path Finding in Stochastic Dynamic Networks, with Application to Routing Hazardous Materials Shipments
Authors: Chang Tsung-Sheng , Nozick Linda K. , Turnquist Mark A.
Published: September 2005

We describe a method for finding nondominated paths for multiple routing objectives in networks where the routing attributes are uncertain, and the probability distributions that describe those attributes vary by time of day. This problem is particularly important in routing and scheduling of shipments of very hazardous materials. Our method extends and integrates the work of several previous authors, resulting in a new algorithm that propagates means and variances of the uncertain attributes along paths and compares partial paths that arrive at a given node within a user-specified time window. The comparison uses an approximate stochastic dominance criterion. We illustrate the effects of changing primary parameters of the algorithm using a small test network, and we show how the nondominated solution set achieved is larger than the set that would be identified if the uncertainty in routing attributes were ignored. We then demonstrate how the algorithm creates an effective solution set in a case study using a large network.
2004 Transportation Science and Logistics Section Dissertation Prize Competition
Authors: Snyder Lawrence , Figliozzi Miguel , Casello Jeffrey Michael , Chang Elaine J. , Chin Chi-Nan , Crittin Frank , Garrow Laurie , Goncalves Paulo , Huisman Dennis , Jin Wenlong , Kang Laura Sumi , Li Zongzhi , Logghe Steven , Peeters Leon , Stier-Moses Nicolas E. , Xiao Weihua
Published: September 2005

The Transportation Science and Logistics (TSL) Section Dissertation Prize Competition is the oldest and most prestigious competition for doctoral dissertations in the transportation science and logistics area. The 2004 TSL dissertation prize committee consisted of Professor Ravi Ahuja (University of Florida), Professor Amy Cohn (Michigan University), Professor Randy Hall (University of Southern California), Professor Mark Hickman (Arizona University), and Professor Patrick Jaillet (Massachusetts Institute of Technology).

Eligible doctoral dissertations were those completed and submitted between June 1, 2003, and May 31, 2004, in the general area of transportation science and logistics. To be considered, a dissertation had to be nominated by the thesis supervisor. This year we received 16 nominations. In addition to the large number of submissions, the quality of the theses was outstanding. I would like to extend my sincere thanks to the committee members for the time, effort, and professionalism they devoted to the difficult task of judging these entries. The awards were announced at the 2004 INFORMS Meeting in Denver.

It is important to remember that submissions to the TSL Dissertation Prize Competition are already distinguished by the fact that they have been nominated for the award. Each makes a unique and valuable contribution to transportation science and logistics, and all entrants and their advisors deserve warmest congratulations.
The Use of Free-Energy Minimization for Calculating β Factors and Equilibrium Compositions in Flame Spectroscopy
Authors: Wittenberg G. K. , Haun D. V. , Parsons M. L.
Published: September 2005

A method is presented for calculating the equilibrium composition in a flame system. The method utilizes a computer program based on the minimization of free energy in the model system. Calculations were made of β values (the free-atom fraction) for 17 elements in the nitrous oxide/acetylene flame and for 15 elements in the air/acetylene flame. Special investigations were made with aluminum in the nitrous oxide/acetylene flame to study the effects of varying flame stoichiometry, matrix elements, and ion formation on the equilibrium composition of the flame system. Applications of the method are discussed.
Information in Spectra of Collision-Broadened Absorption Lines
Authors: Niple E. , Shaw J. H.
Published: September 2005

A mathematical model is introduced for experiments which yield spectra of isolated, collision-broadened absorption lines. A nonlinear design analysis is then performed on the model to identify the optimum experimental conditions. The information in the spectra is split into components associated with each of the unknown parameters to be estimated from the spectra. By exploring the variation of these components it is shown that spectra with line center transmittances of 0.25 are nearly optimum for measuring the line position, the Lorentz width α, the instrument resolution H, and the product of line intensity and absorber amount. The trade off between signal/noise ratio and resolution is investigated for several different resolution-dependent noise levels. The analysis shows that when signal/noise ratio is proportional to the square root of the ratio of resolution and Lorentz width, a single optimum resolution and line center transmittance combination of H/α ≅ 1.5 and 0.28, respectively, exists.
Energy-Dispersive X-ray Spectrometric Analysis of NBS Standard Reference Material 1571 Orchard Leaves after Oxidation and Borate Fusion
Authors: Kuehner E. C. , Pella P. A.
Published: September 2005

An automated borate fusion procedure was investigated as a sample preparation method, after removal of organic matter, for the analysis of seven elements in NBS Standard Reference Material 1571 Orchard Leaves by energy-dispersive x-ray spectrometry. A 2.0 g sample was pretreated by oxidation with H2SO4—HNO3 acid mixture and the residue was fused with 6.5 g of lithium tetraborate in the conventional manner. Relative errors on the order of 2 to 10% were obtained for K, Ca, Fe, Mn, Zn, and Pb.
The Infrared Spectra of Some 1-(2-Thienyl)-3- and -4-Thiaalkanes
Authors: Foster Norman G. , Bonner Bernice B. , Higgins Robert W.
Published: September 2005

The infrared spectra of six 1-(2-thienyl)-3-thiaalkanes and seven 1-(2-thienyl)-4-thiaalkanes (molecular weights from 186 to 270) were obtained for the 4000 to 400 cm−1 range. These spectra are compared with spectra of other thiophene ring compounds substituted in the 2-position for their characteristic absorption bands. The spectra agree with other spectra as to the major absorption band around 680 cm−1 and the 2-substitution overtone pattern. A method of distinguishing between the two groups of compounds from moderate peaks in the 600 to 500 cm−1 (KBr) region is shown. Interference from the 2-alkylthiophenes and the 1-(2-thienyl)-1-thiaalkanes does not occur.
Assignment of the Carbon-Hydrogen Stretching and Bending Vibrations of Poly(Methyl Methacrylate) by Selective Deuteration
Authors: Dirlikov Stoil K. , Koenig Jack L.
Published: September 2005

The C—H stretching and C—H bending vibrations of the methylene, α-methyl, and ester methyl groups of poly(methyl methacrylate) are discussed and assigned on the basis of the infrared spectra of its three deuterated derivatives: PMMA—CD3—OCD3, PMMA—CD2—OCD3, and PMMA—CD2—CD3. The digital analog of PMMA is obtained by coaddition of the Fourier transform infrared spectra of the deuterated PMMA derivatives. The experimental and digital PMMA spectra are compared in the regions of the C—H stretching and C—H bending vibrations: the agreement in frequency is excellent and the relative intensities are practically the same in the C—H stretching vibrations region. However, their relative intensities strongly differ in the C—H bending region.
Line Broadening and Radiative Recombination Background Interferences in Inductively Coupled Plasma-Atomic Emission Spectroscopy
Authors: Larson G. F. , Fassel V. A.
Published: September 2005

Spectral line broadening and radiative electron-ion recombination processes may make significant contributions to the total spectral background level when inductively coupled plasma excitation sources are observed with spectrometers having low stray light levels. These background contributions are more easily identified in inductively coupled plasma discharges because of their stable background level and by the fact that net analyte line intensities are affected to such a small degree by changes in the concentration of concomitants. The wings of collisionally broadened lines may produce significant background changes at wavelengths removed 10 nm from the parent line center. For some elements such as Mg, linear Stark-broadened lines produced spectral background at unexpectedly large displacements from the line center. The radiative Al ion-electron recombination continuum produces a greater than tenfold increase in the background from ∼210 down to 193 nm at Al solution concentration of 2500 μg/ml. Thus, a solution containing only 250 μg/ml of Al will cause an ∼100% increase in the background level below 210 nm over that measured when deionized water is nebulized into the plasma.
Calcium Isotope Effects in Atomic Absorption
Authors: Nash C. P. , Rock P. A. , Silberman D. , Fisher G. L.
Published: September 2005

Measurements are reported for the absorption of the 422.7 nm line of a natural-abundance calcium hollow cathode lamp by solutions of 40Ca, 44Ca, and 48Ca at 0.5 to 3.0 ppm levels in 0.06 M HCl (aqueous) when aspirated into air-acetylene and nitrous oxide-acetylene flames. In the case of the air-acetylene flame the relative absorptions per mole of calcium in solution were 1.00, 1.11, and 1.08 for the 40, 44, and 48 isotopes, respectively. With the nitrous oxide-acetylene flame similar experiments gave ratios of 1.00, 1.08, and 1.06 in the same order. These results may be rationalized with a model that considers the simultaneous effects of isotope shifting, Lorentz broadening and shifting, and Doppler broadening of the calcium resonance line in the flame. With the air-acetylene flame, solutions that also contained 5000 ppm of Sr as SrCl2 gave relative absorbances for the 40, 44, and 48 calcium isotopes of 1.00, 1.04, and 1.10. Flame-atomic-distribution studies lead to the conclusion that in the presence of 5000 ppm of Sr, calcium kinetic isotope effects are also important.
Determination of Antimony in Lead-Antimony Alloys by Atomic Absorption Spectroscopy Using Indium as an Internal Standard
Authors: Kramer Gary W.
Published: September 2005

A rapid, precise analytical method has been developed by the United States Department of the Interior, Bureau of Mines, for the determination of antimony in lead-antimony alloys. The alloy (0.10 to 30.0 wt.% Sb) is rapidly dissolved in a 10% volume nitric acid solution containing ∼5 g of tartaric acid. Antimony is determined by atomic absorption using indium as an internal standard. The relative standard deviation for this internal standard method, based on the analysis of three National Bureau of Standards (NBS) Standard Reference Materials, is approximately 0.50%; an improvement over conventional atomic absorption and a volumetric method by a factor of 5 to 8. The internal standard procedure gives values that are in better agreement with the NBS certified values than analyses using the alternative methods. Analytical time required is less than 30 min.
Examination of the Spectral Efficiency of an Echelle Grating Monochromator
Authors: Zander Andrew T. , Keliher Peter N.
Published: September 2005

The spectral efficiency of an echelle grating monochromator has been examined. The frequently cited advantage that “echelles are blazed at all wavelengths” is observed to be a result of the periodic character of the echelle efficiency as compared with the continually decreasing efficiency from the blaze wavelength for conventional gratings. The periodic character of the echelle efficiency may be also a disadvantage, particularly when regions near the ends of the orders are utilized, since the efficiency may drop significantly below the theoretical decrease of 50%. An awareness of the efficiency character of the echelle grating monochromator should facilitate the choice of wavelength region in which to work
Retrieval of Information from an Absorption Spectrum
Authors: Lin C. L. , Niple E. , Shaw J. H. , Calvert J. G.
Published: September 2005

Information about the pressure, temperature, and amount of gas in a sample and the spectral resolution of its absorption spectrum is obtained by nonlinear least squares analysis of the spectrum and sets of absorption coefficients derived from appropriate reference spectra of the absorber. Spectra of N2O are analyzed to demonstrate the technique.
Measurement of the Near-Infrared Spectra of H2O-SiOH-Bearing Siliceous Materials at High Pressures
Authors: Langer Klaus , Luck Werner A. P. , Schrems Otto
Published: September 2005

Techniques for measuring OH-combination bands of water and other OH-group bearing solid or liquid materials in the near-infrared (6000 to 4000 cm−1) at high pressures by means of a modified diamond anvil cell, adapted to a single beam micro-spectrometer, have been developed and applied to opals, i.e., minerals in the system SiO2-H2O containing relatively high amounts of water and SiOH. Liquid embedding, using the gasket technique and poly-fluoro-carbon oils as embedding liquids, which provide a hydrostatic pressure environment at least up to 50 kbar, is applied for solid materials. The high pressure near-infrared spectra of gel-like, spherulitic opal-AG show a strong relative decrease of the high energy components of the complex (v1 + v2)H2O-band system at around 5200 cm−1 in favor of the low energy components of this band system. This is tentatively interpreted as due to an increase of fully hydrogen bonded water at the expense of water in which only one OH-group is H-bonded. The corresponding effect in opal-AN with a glass-like continuous SiO4/2-tetrahedral network is much smaller.
Spectroscopic Investigations of Mono-Substituted Acetic Acids
Authors: Ray W. J. , Katon J. E. , Krause P. F.
Published: September 2005

Measurement of a number of characteristic spectroscopic features of a series of mono-substituted acetic acids has been performed. Selected infrared, near infrared, ultraviolet, Raman, and nuclear magnetic resonance data are presented. Attempts have been made to correlate these data with the pKa values and Taft sigma constants. Correlation coefficients have been calculated, and their values are discussed in terms of various specific structural features.
Raman Study on Glasses and Crystalline Compounds in the System K3AsO4-KAsO3
Authors: Verweij H.
Published: September 2005

Raman and IR spectra of the crystalline compounds α-K3AsO4 K4As2O7, K5As3O10, and γ-KAsO3 are given together with tentative assignments in terms of symmetrical and antisymmetrical As—O− and As—O—As bond-stretching and bond-bending vibrations. Comparison of the Raman spectra of crystalline arsenates with those of vitreous arsenates, stabilized with Al2O3, in the composition region KAsO3-K4As2O7 is used to deduce the molecular structure of these glasses. It appears that in the glasses chains of AsO4 tetrahedra are present.
A Stable Pulsed Hollow Cathode Power Supply
Authors: Dewalt Frederic G. , Amend John R. , Woodriff Ray
Published: September 2005

A circuit for a stable pulsed hollow cathode power supply is described. The long term current stability of this power supply is shown to have a relative standard deviation of ±0.0082%. This power supply has been used to replace the optical chopper in conventional atomic absorption systems using lock-in amplifier type data acquisition.
Matrix Isolation Microsampling Procedures in Quantitative Fourier Transform Infrared Spectrometry
Authors: Hembree Doyle M. , Hinton E. Ray , Kemmerer Richard R. , Mamantov Gleb , Wehry E. L.
Published: September 2005

Techniques for microsampling in infrared spectroscopy by matrix isolation are described. In the matrix isolation of liquid or solid compounds, the sample is vaporized and then diluted with a large excess of a matrix gas; the resulting gaseous mixture is deposited on a cold surface for spectroscopic examination as a solid. Detailed descriptions of the apparatus and procedures employed in the preparation of matrix-isolated samples for qualitative and quantitative analyses by Fourier transform infrared spectrometry are presented. Systems for “microsampling” (detection limits for specific compounds ∼0.5 to 1 μg) and “ultramicrosampling” (detection limits ∼50 to 100 ng) matrix isolation spectroscopy are described. Detection limits and Beer's law behavior for polycyclic aromatic hydrocarbons microsampled by matrix isolation are discussed. The advantages of matrix isolation as a technique for qualitative and quantitative infrared analysis of microsamples are itemized.
Mass Spectral Analysis of Rice Leaves
Authors: Ramaswamy K. , Perumal R. , Pandurangan S. V.
Published: September 2005

Mass spectral analysis of the mineral constituents of the flag leaves of some varieties of rice, Ponni, IR-26, IRRI-50, and TKM-6, which are highly resistant to the brown spot disease Cercospora oryzae and Kanchi, Karuna, Kannagi, and Co-25, which are highly susceptible to the same disease, was carried out. The elements present in the flag leaves of the rice varieties were classified into major elements viz., Si, K, Ca, P, and Mg and microelements viz., B, Na, Al, Cl, Cr, Fe, Mn, Co, Cu, Zn, As, Br, Rb, Sr, Mo, Ag, Ba, and Pb. It is found that the amount of Fe, Ca, Sr, Pb, and Ag is greater in susceptible varieties while the quantity of K is low in these samples.
The Quantitative Analysis of Absorption Spectra
Authors: Lin C. L. , Niple E. , Shaw J. H. , Calvert J. G.
Published: September 2005

Methods of estimating the information in an absorption spectrum concerning the amount of absorber are presented. The analysis allows a single value of the absorber amount and its standard deviation to be obtained when a wide region of the spectrum is analyzed. An empirical method of reducing the errors caused by departures from Beer's Law is demonstrated to improve the results of the analysis of synthetic spectra of N2O.
Induction-Coupled Plasma Determination of Ag, Au, Bi, Cd, Cu, Pb, and Zn in Geologic Materials Using a Selective Extraction Technique—Preliminary Investigation
Authors: Motooka J. M. , Mosier E. L. , Sutley S. J. , Viets J. G.
Published: September 2005

The expanding need for multielement analysis at submicrogram levels in geologic materials has prompted an increased interest in inductively coupled plasma spectrometry. No other analytical procedure simultaneously exhibits, to the same degree, the operating characteristics of excellent precision and accuracy, low limits of detection, dynamic concentration ranges in addition to eliminating or at least reducing, interelemental and matrix effects. The experimental and operating parameters are described for the analyses of trace metals found in the organic phase following a rapid and efficient extraction technique. Direct spectral interferences, matrix and interelemental effects caused by major elements in geologic materials are effectively eliminated and sensitivity is increased by concentrating the trace metals in the organic phase. Aluminum, calcium, iron, potassium, magnesium, manganese, and sodium are among the major elements eliminated; and trace elements (Ag, Au, Bi, Cd, Cu, Pb, and Zn) critical to a mineral evaluation, some of which have insufficient detection limits by plasma analyses, are enhanced to a more precise detection level.
An X-Ray Photoelectron Spectroscopic Study of Copper Chromite Catalysts
Authors: Schreifels J. A. , Rodero A. , Swartz W. E.
Published: September 2005

A series of copper chromite catalysts have been studied by x-ray photoelectron spectroscopy. The data indicate that in the as-received form the copper is present as a mixture of Cu(OH)2 and CuO. After calcination at 500 °C only CuO is present. The chromium is present as Cr+3 and Cr+4 when no promoter is added. When a BaO promoter is added, the Cr+6 is stabilized. Calcination at 500°C for varying periods of time alter the relative amounts of Cr+3 and Cr+6 on the catalytic surface. In addition, the relative amounts of the various oxidation states are a function of calcination temperature. At a calcination temperature of 240°C a Cr+5 surface species is reproducibly observed in one of the catalysts.
Interferences in the Determination of Titanium in Silicate Rocks and Venezuelan Laterites by Atomic Absorption Spectroscopy
Authors: La Brecque J. J.
Published: September 2005

A method to overcome the numerous interferences present for the determination of titanium in Venezuelan laterites and bauxites has been adopted. The technique is based on dissolving the sample in the HF-H3BO3 matrix. The advantages of using this system are discussed. After the sample is decomposed in this system, 1 part of 2000 ppm of Al, Si, and Fe in the same system is added to 9 parts of the decomposition solution. The atomic absorption determination is employed using the conventional standard curve method for the 364.3 nm line. A comparison of this method with x-ray fluorescence and colorimetry is given in search of one method for routine batch determinations. Interference studies of aluminium, silicon, and iron, the common major elements in Venezuelan laterites and bauxites, conclude that both aluminum and iron greatly affect the absorption signal for titanium. The proposed method, as well as x-ray fluorescence and colorimetry, was applied to standard reference rocks and a preliminary profile of Venezuelan laterites (ferrugineous bauxites).
Characteristics of a “High Solids” Nebulizer for Flame Atomic Absorption Spectrometry
Authors: Fry R. C. , Denton M. B.
Published: September 2005

Studies are presented to characterize a new nebulizer developed for direct atomic absorption analysis of extremely complex clinical and environmental materials. Important parameters are described concerning the design and performance of “high solids” spectrochemical nebulizers based on the Babington principle. A new simplified design is presented and mechanisms of undesirable sample wastage are considered. Data are presented concerning the effect of impaction on conventional and “high solids” aerosol generation.
Hydride Preconcentration for Inductively Coupled Plasma Optical Emission Spectrometry
Authors: Fry R. C. , Denton M. B. , Windsor D. L. , Northway S. J.
Published: September 2005

Studies are presented describing an improved application of the NaBH4 reduction of soluble arsenite to form arsine as a preconcentration approach for ultra-trace level arsenic determination by inductively coupled plasma optical emission spectrometry. Specialized analyte introduction techniques are described for elimination of reaction by-products that would normally extinguish a medium power plasma discharge. An approach is presented to minimize the need for background correction and facilitate a superior arsenic detection limit (≤0.03 ng/ml) in a relatively inexpensive 1.2 kW inductively coupled plasma system.
Library Retrieval of Infrared Spectra Based on Detailed Intensity Information
Authors: Rasmussen G. T. , Isenhour T. L.
Published: September 2005

Infrared spectral searches which rely on detailed intensity information and those based on peak position information are compared using a library of 500 reference spectra. Spectra with detailed intensity information are encoded with absorbance values for 200 resolution increments spanning the range from 4000 to 200 cm−1. Three different distance metrics are evaluated for searches using intensity information, and the effects of selecting data from limited regions of the infrared spectrum are examined.
Factor Analysis Applied to Fourier Transform Infrared Spectra
Authors: Antoon Mitchell K. , D'Esposito Louis , Koenig Jack L.
Published: September 2005

The feasibility of applying the methods of factor analysis to Fourier transform infrared spectra is examined. The method is designed to determine the number of components contributing to a spectral region. The technique has been applied to a model system consisting of solutions of p−, o−, and m-xylenes. The method has also been used for calculating the number of independently absorbing species in several polymer systems. Spectral requirements and the general applicability of factor analysis are also discussed.