bluuebunny/crossref_metadata_2025 huggingface dataset:
The Chrispin–Norman score in cystic fibrosis: doing away with the lateral view
Authors: Benden C. , Wallis C. , Owens C. M. , Ridout D. A. , Dinwiddie R.
Published: November 2005

The Chrispin–Norman chest radiograph scoring (CNS) system is widely used to assess respiratory disease progression in cystic fibrosis (CF). Frontal and lateral chest radiographs were performed. The present authors developed a modified CNS, which obviates the need for the lateral film. This study compares the original and the current authors' modified scoring system.

A total of 50 chest radiographs from CF children, taken between August and December 2003, were scored according to the original and modified CNS. Two observers scored all 50 chest radiographs, scoring in random order the frontal radiographs, and separately the frontal and lateral radiographs together.

There was no evidence of a difference between the methods for either observer, using the Bland and Altman 95% limits of agreement as follows: observer 1 (−2.0–1.9), and observer 2 (−1.77–2.2). No evidence of a difference between the observers for either method was found, comparing the 95% limits of agreement (−5.5–5.7) with the modified CNS (−5.6–6.4).

In conclusion, in terms of the final score, good agreement was found between the use of the original and modified Chrispin–Norman score. In addition, low inter-observer variability was shown for both methods. The use of the modified Chrispin–Norman chest radiograph scoring system to stage disease severity in cystic fibrosis removes the need for a lateral chest radiograph.
The role of post-transcriptional regulation in chemokine gene expression in inflammation and allergy
Authors: Fan J. , Heller N. M. , Gorospe M. , Atasoy U. , Stellato C.
Published: November 2005

The aim of this review is to discuss recent advances in the understanding of the regulation of chemokine expression occurring during chronic inflammatory conditions, such as allergic diseases. The focus will be on current data, which suggest that post-transcriptional regulation plays a larger role in chemokine gene regulation than previously recognised. In particular, a growing body of data indicates that mechanisms controlling mRNA stability may be relevant in determining, or maintaining, the increased levels of chemokine gene expression in this context. Such regulatory pathways may be important targets of novel anti-inflammatory strategies.
A 20-year follow-up study on chronic respiratory effects of exposure to cotton dust
Authors: Wang X-R. , Zhang H-X. , Sun B-X. , Dai H-L. , Hang J-Q. , Eisen E. A. , Wegman D. H. , Olenchock S. A. , Christiani D. C.
Published: November 2005

In order to evaluate chronic effects of long-term exposure to cotton dust on respiratory health, and the role of dust and endotoxin, longitudinal changes in lung function and respiratory symptoms were observed prospectively from 1981 to 2001 in 447 cotton textile workers, along with 472 silk textile controls.

The results from five surveys conducted over the 20-yr period are reported, including standardised questionnaires, pre- and post-shift spirometric measurements, work-area inhalable dust sample collections and airborne Gram-bacterial endotoxin analysis.

Cotton workers had more persistent respiratory symptoms and greater annual declines in forced expiratory volume in one second (FEV1) and forced vital capacity as compared with silk workers. After exposure cessation, in the final 5-yr period, the rate of FEV1decline tended to slow in nonsmoking males, but not in nonsmoking females. Workers who reported byssinotic symptoms more persistently suffered greater declines in FEV1. Chronic loss in lung function was more strongly associated with exposure to endotoxin than to dust.

In conclusion, the current study suggests that long-term exposure to cotton dust, in which airborne endotoxin appears to play an important role, results in substantial adverse chronic respiratory effects.
Control design to shape the stationary probability density function
Authors: Forbes Michael G. , Forbes J. Fraser , Guay Martin
Published: November 2005

This paper extends a regulatory controller synthesis technique that was previously introduced for first-order processes to higher-order processes. The target of the design is to find a feedback control law such that the multivariate stationary probability density function (PDF) for the closed-loop process reasonably approximates a preselected target PDF. With the idea already motivated and introduced in previous work, the focus of this paper is on dealing with the various complications that arise when the process dimension is greater than one. As in the previous case, the main idea of multivariate PDF-shaping is to reduce the integral equation that governs the relationship between process dynamics and stationary PDF to a set of algebraic equations. The proposed approach relies on parameterization of the feedback control law to simplify manipulation of the integral equation. Numerical simulations with an example process are used to demonstrate application of the technique.
Violent behaviour in schizophrenia
Authors: Vevera Jan , Hubbard Alan , Veselý Arnošt , Papežová Hana
Published: November 2005

Background

A number of studies have reported increased violence in patients with schizophrenia.

Aims

To determine the prevalence of violence among those with schizophrenia in samples from 1949, 1969, 1989 and 2000 in Prague (Czech Republic) and to examine trends in this behaviour.

Method

Records from 404 patients meeting DSM–IV criteria for schizophrenia were screened for violence (defined as 3 points on the Modified Overt Aggression Scale) from the first observed psychotic symptoms until the time of latest available information.

Results

Logistic regression revealed a marginally significant increase in violence only inthe 2000 cohort. Overall, violence was associated with schizophrenia in 41.8% of men and 32.7% of women, with no association between substance misuse and violence.

Conclusions

The violence rate found in our sample is expected to remain stable over time under stable conditions. Substance misuse is not the leading cause of violence among those with schizophrenia.
Processes of disengagement and engagement in assertive outreach patients: qualitative study
Authors: Priebe Stefan , Watts Jay , Chase Mike , Matanov Aleksandra
Published: November 2005

Background

Assertive outreach has been established to care for ‘difficult to engage’ patients, yet little is known about how patients experience their disengagement with mainstream services and later engagement with outreach teams.

Aims

To explore the views of disengagement and engagement held by patients of assertive outreach teams.

Method

In-depth interviews were conducted with 40 purposefully selected patients and analysed using components of both thematic analysis and grounded theory.

Results

Patients reported a desire to be independent, a poor therapeutic relationship and a loss of control due to medication effects as most important for disengagement. Time and commitment of staff, social support and engagement without a focus on medication, and a partnership model of the therapeutic relationship were most relevant for engagement.

Conclusions

The findings underline the importance of a comprehensive care model, committed staff with sufficient time, and a focus on relationship issues in dealing with ‘ifficultto engage'patients.
Experience of caring for someone with anorexia nervosa: qualitative study
Authors: Whitney Jenna , Murray Joanna , Gavan Kay , Todd Gill , Whitaker Wendy , Treasure Janet
Published: November 2005

Background

Caring for someone with anorexia nervosa is distressing.

Aims

To gain a detailed understanding of carers' illness models and caregiving experiences.

Method

Qualitative analysis and computerised text analysis were conducted on narratives written by parents as part of a family intervention at a specialist in-patient unit (20 mothers, 20 fathers)

Results

Themes concerned illness perceptions, impact on the family and carers' emotional, cognitive and behavioural responses towards the illness. Parents perceived anorexia nervosa to be chronic and disabling. Carers blamed themselves as contributing to the illness and perceived themselves as helpless in promoting recovery. Mothers illustrated an intense emotional response, whereas fathers produced a more cognitive and detached account.

Conclusions

Part of the distress in living with anorexia nervosa may be explained by unhelpful assumptions and maladaptive responses to the illness. Training parents in skills to manage the illness may improve outcome by reducing interpersonal maintaining factors.
Mortality and suicide after non-fatal self-poisoning: 16-year outcome study
Authors: Owens David , Wood Christopher , Greenwood Darren C. , Hughes Tom , Dennis Michael
Published: November 2005

Background

Suicide reduction is government strategy in many countries. We need to quantify the connection between non-fatal self-poisoning and eventual suicide.

Aims

To determine mortality after an episode of self-poisoning and to identify predictors of death by any cause or by suicide.

Method

A retrospective single-group cohort study was undertaken with 976 consecutive patients attending a large accident and emergency unit in 1985–1986 after non-fatal self-poisoning. Information about deaths was determined from the Office for National Statistics.

Results

Of the original patients, 94% were traced 16 years later; 17% had died, 3.5% by probable suicide. Subsequent suicide was related to numerous factors evident at the time of the episode of self-poisoning but, when examined for their independent effects, only the severity of the self-poisoning episode and relevant previous history seemed important.

Conclusions

Patients attending a general hospital after self-poisoning all require good basic assessment and care responsive to their needs. Attempts to reduce the huge excess of suicide subsequent to self-harm are not likely to achieve much if they are based on the identification of subgroups through ‘risk assessment’
The Postgraduate Medical Education and Training Board (PMETB) goes live
Authors: Brown Nick
Published: November 2005

The Postgraduate Education and Training Board (PMETB) was established by the General and Specialist Medical Practice (Education and Qualifications) Order, approved by parliament on 4 April 2003 to develop a single, unifying framework for postgraduate medical education and training across the UK. The Order placed a duty on the Board to establish, maintain and develop standards and requirements relating to all aspects of postgraduate medical education and training in the UK.
Temozolomide in Combination With Interferon-Alfa Versus Temozolomide Alone in Patients With Advanced Metastatic Melanoma: A Randomized, Phase III, Multicenter Study from the Dermatologic Cooperative Oncology Group
Authors: Kaufmann Roland , Spieth Konstanze , Leiter Ulrike , Mauch Cornelia , von den Driesch Peter , Vogt Thomas , Linse Ruthild , Tilgen Wolfgang , Schadendorf Dirk , Becker Jürgen C. , Sebastian Günther , Krengel Sven , Kretschmer Lutz , Garbe Claus , Dummer Reinhard
Published: November 2005

Purpose

Temozolomide (TMZ) has shown efficacy in metastatic melanoma equal to that of dacarbazine (DTIC), the standard chemotherapeutic agent for melanoma. As the combination with interferon-alfa (IFN-α) appears superior to single-agent DTIC regarding response rates, the purpose of this study was to compare TMZ alone and TMZ plus IFN-α in terms of objective response (OR), overall survival, and safety in a prospective, randomized, multicenter trial.

Patients and Methods

Two hundred ninety-four patients with untreated stage IV metastatic melanoma (American Joint Committee on Cancer staging system) were randomly assigned to receive either oral TMZ alone (200 mg/m2/day; days 1 through 5 every 28 days) or in combination with subcutaneous IFN-α (5 MU/m2; days 1, 3, and 5 every week).

Results

Two hundred eighty-two patients were eligible for an intent-to-treat analysis, 271 patients were treated per protocol. In the TMZ + IFN-α arm, 33 (24.1%) of 137 patients responded to therapy (partial or complete remission) whereas in the monotherapy arm, in 18 (13.4%) of 134 patients, a response was evident. Thus, the response rate was significantly higher in the combination arm (P = .036). Median survival time was 8.4 months for patients treated with TMZ (95% CI, 7.07 to 9.27) and 9.7 months for those treated with the combination (95% CI, 8.26 to 11.18; P = .16). Dose modifications and interval prolongations due to hematologic toxicity were significantly more frequent in the TMZ + IFN-α arm (P < .001).

Conclusion

In metastatic melanoma treatment with TMZ + IFN-α leads to a significantly superior OR rate compared to treatment with TMZ alone, which did not translate into prolonged survival in our study population.
Risk-Adapted Management for Patients With Clinical Stage I Seminoma: The Second Spanish Germ Cell Cancer Cooperative Group Study
Authors: Aparicio Jorge , Germà José R. , del Muro Xavier García , Maroto Pablo , Arranz José A. , Sáenz Alberto , Barnadas Agustín , Dorca Joan , Gumà Josep , Olmos David , Bastús Romá , Carles Joan , Almenar Daniel , Sánchez Miguel , Paz-Ares Luis , Satrústegui Juan J. , Mellado Begoña , Balil Ana , López-Brea Marta , Sánchez Alfredo
Published: November 2005

Purpose

To assess the efficacy of a risk-adapted treatment policy for patients with stage I seminoma by using universally accepted risk criteria.

Patients and Methods

Between 1999 and 2003, 314 patients with clinical stage I seminoma after orchiectomy were prospectively included. One hundred patients (31.8%) presented no risk factors and were managed with surveillance. In contrast, 131 patients (41.7%) had tumors larger than 4 cm, 33 patients (10.5%) had rete testis involvement, and 50 patients (15.9%) had both risk factors. All the latter received two courses of adjuvant carboplatin.

Results

Chemotherapy was well tolerated, as only 17 patients (7.9%) presented grade 3 to 4 toxicity. Relapses were observed in six patients (6.0%) on surveillance and in seven patients (3.3%) treated with carboplatin (0.8% of tumors larger than 4 cm, 9.1% of those involving the rete testis, and 6.0% of patients with both risk criteria). All were located at the retroperitoneum, except for one at the spermatic cord. Median tumor size was 25 mm (range, 11 to 70 mm), and median time to relapse was 9 months (range, 4 to 28 months). All patients were rendered disease-free with chemotherapy (etoposide plus cisplatin). Median follow-up was 34 months (range, 12 to 72 months). The actuarial 5-year disease-free survival rate was 93.4% for patients on surveillance and 96.2% for patients treated with adjuvant chemotherapy. Overall 5-year survival was 100%.

Conclusion

Adjuvant carboplatin is effective in reducing the relapse rate in patients with stage I seminoma and risk factors. A risk-adapted strategy is safe and feasible and should be considered an alternative to systematic approaches, such as irradiation, chemotherapy, or surveillance.
Kinetics of Response to Long-Term Treatment Combining Pentoxifylline and Tocopherol in Patients With Superficial Radiation-Induced Fibrosis
Authors: Delanian Sylvie , Porcher Raphaël , Rudant Jérémie , Lefaix Jean-Louis
Published: November 2005

Purpose

Significant regression of radiation (RT) -induced fibrosis (RIF) has been achieved after treatment combining pentoxifylline (PTX) and alpha-tocopherol (vitE). In this study, we focus on the maximum response, how long it takes to achieve response, and changes after treatment discontinuation.

Patients and Methods

Measurable superficial RIF was assessed in patients treated by RT for breast cancer in a long-treatment (24 to 48 months) PTX-vitE (LPE) group of 37 patients (47 RIFs) and in a short-treatment (6 to 12 months) PTX-vitE (SPE) group of seven patients (eight RIFs). Between April 1995 and April 2000, women were treated with a daily combination of PTX (800 mg) and VitE (1,000 IU).

Results

Combined PTX-vitE was continuously effective and resulted in exponential RIF surface area regression (−46% for LPE and −68% for SPE at 6 months, −58% for LPE and −69% for SPE at 12 months, −63% for LPE and −62% for SPE at 18 months, and −68% for LPE at 24 and 36 months). The mean estimated maximal treatment effect was 68% RIF surface area regression. The mean time to this effect was 24 months and was shorter (16 months) in more recent RIF (< 6 years since RT) than in older RIF (28 months; P = .0003). Symptom severity (Subjective Objective Medical Management and Analytic Evaluation score) was halved in both groups. After treatment discontinuation, mean RIF surface area at 1 year had increased by +40% in the SPE group (rebound) and +8.5% in the LPE group.

Conclusion

Under combined PTX-vitE treatment, RIF regression was exponential, with a two-thirds maximum response after a mean of 2 years. There was a risk of a rebound effect if treatment was too short. Long treatment (≥ 3 years) is recommended in patients with severe RIF.
Colorectal Cancer Surveillance: 2005 Update of an American Society of Clinical Oncology Practice Guideline
Authors: Desch Christopher E. , Benson Al B. , Somerfield Mark R. , Flynn Patrick J. , Krause Carol , Loprinzi Charles L. , Minsky Bruce D. , Pfister David G. , Virgo Katherine S. , Petrelli Nicholas J.
Published: November 2005

Purpose

To update the 2000 American Society of Clinical Oncology guideline on colorectal cancer surveillance.

Recommendations

Based on results from three independently reported meta-analyses of randomized controlled trials that compared low-intensity and high-intensity programs of colorectal cancer surveillance, and on recent analyses of data from major clinical trials in colon and rectal cancer, the Panel recommends annual computed tomography (CT) of the chest and abdomen for 3 years after primary therapy for patients who are at higher risk of recurrence and who could be candidates for curative-intent surgery; pelvic CT scan for rectal cancer surveillance, especially for patients with several poor prognostic factors, including those who have not been treated with radiation; colonoscopy at 3 years after operative treatment, and, if results are normal, every 5 years thereafter; flexible proctosigmoidoscopy every 6 months for 5 years for rectal cancer patients who have not been treated with pelvic radiation; history and physical examination every 3 to 6 months for the first 3 years, every 6 months during years 4 and 5, and subsequently at the discretion of the physician; and carcinoembryonic antigen every 3 months postoperatively for at least 3 years after diagnosis, if the patient is a candidate for surgery or systemic therapy. Chest x-rays, CBCs, and liver function tests are not recommended, and molecular or cellular markers should not influence the surveillance strategy based on available evidence.
Some Statistical Aspects of X-Ray Fluorescence Spectrometry
Authors: Horton William S.
Published: November 2005

A simple derivation of the probability distribution function for the time to accumulate a preset number of counts is outlined. The result is applied to X-ray fluorescence spectrometry in order to estimate the expected precision of the various measures of quantity of an element. Examples are given to show how the results may be used as a practical guide in this field of analytical chemistry.
Correlations of Alkybenzene Structures with Mass Spectra
Authors: Meyerson Seymour
Published: November 2005

Correlations of alkylbenzene structures with mass spectra show clearly that structural features determine the products of dissociation by electron impact. The most-abundant ions derive from cleavage of bonds β to the benzene ring. Increase in length of side-chains promotes: (a) decomposition of the parent ion, (b) cleavage of carbon-carbon bonds in competition with carbon-hydrogen bonds, (c) cleavage of β bonds in competition with a bonds, and (d) hydrogen migration accompanying bond cleavage. Side-chain branching, number, and position on the benzene ring help fix the product distribution. The factors that govern dissociation of alkylbenzenes apply broadly to the dissociation of other arenes and related heterocyclic compounds. A scheme for the identification of alkylbenzenes, based upon the correlations, has proved effective in analyzing samples that did not yield readily to other techniques.
“Infrared Spectra of Steroids. II. The Influence of the Solvent on Carbonyl Frequency Correlations”
Authors: Tarpley William , Vitiello Cecelia
Published: November 2005

The influence of solvents on frequencies of the carbonyl absorption bands in the infrared spectra of 56 steroids has been investigated with a double beam spectrophotometer. Good agreement was obtained with data previously published for the characteristic frequencies in carbon disulfide for similar types of ketosteroids. The carbonyl absorption maxima in chloroform and methylene bromide were displaced toward lower frequencies by about 2–17 cm−1 from their frequencies in carbon disulfide or carbon tetrachloride. The magnitude of the shift depended upon the location and type of carbonyl group. Additional dispalcement of the order of 1–19 cm−1 was found in bromoform solution. In mineral oil spectra, considerable variation in frequencies were observed for a particular carbonyl group at the same position in different steroid molecules. The absorption maxima of two Δ5-7-ketosteroids are reported for the first time to be at the same position as those of Δ4-3-ketosteroids. A new interaction of the 3 a, 9a-epoxides with the 11 carbonyl group has been suggested. While Δ4-3-ketosteroids could not be distinguished from Δ9-12-ketosteroids in carbon disulfide or carbon tetrachloride, the absorption maxima were at sufficiently different frequencies in chloroform or methylene bromide. In a series of four ketones with the carbonyl group at different positions along the side chain, it was observed that the 24 and 25 carbonyl absorption bands were closer to those of simple aliphatic ketones than the 20 and 22 ketones. A similar shift to higher frequencies as the chain length was increased was observed for three steroid acids. When the ketonic absorption band was very close to that of an acetate, broadening of the latter band in chloroform, methylene bromide and bromoform resulted in poor resolution.
The Analysis of Overlapping Spectral Absorption Bands by Derivative Spectrophotometry
Authors: Giese Arthur T. , French C. Stacy
Published: November 2005

In the measurement of absorption spectra, it is difficult to detect low intensity bands overlapped by bands of higher intensity. Their detection is greatly facilitated by measuring the first derivative of the transmission curve with respect to wavelength. A machine is under development in this laboratory to plot this derivative. A graphical study is here made of the behavior of the derivative curves for overlapping absorption bands of differing heights, widths and separation intervals and the derivatives are compared with the corresponding extinction and percent transmission curves. The curves here presented are intended as illustrations of the possibilities inherent in derivative spectrophotometry and for the identification of extinction or transmission curve types from measured derivatives.
The Spectrochemical Determination of Argon in Air
Authors: Lee Ted
Published: November 2005

A spectrochemical procedure to determine the ratio of the concentration of argon in a sample slightly different from air to the concentration of argon in air was developed using an electrodeless discharge tube and a 22-foot direct-reading optical spectrometer. A precision of ±0.43% at the 95% confidence level was obtained for a single determination made in 1 minute.

A method of relative precisions to obtain optimum adjustments of the equipment is described. This method was used to determine the optimum discharge tube pressure and the optimum entrance slit width.
A Rotating Electrode for Spectrographic Analysis of Metallic Samples
Authors: Dotson Clifford L.
Published: November 2005

A rotating electrode for the spectrographic analysis of metallic samples is described in detail. The method uses cast disc samples 2 1/2 inches in diameter from one-fourth to one-half inch thick. Samples are rotated in a plane perpendicular to the primary slit of the spectrograph at speeds up to five R.P.M. The method of supporting the sample necessitates machining only one surface of the sample to provide both the supporting and sparking surfaces and assures a constant analytical gap distance during rotation. Analytical results are given for the determination of tin and aluminum in zinc and are statistically analyzed for precision by the rotating and conventional methods of analysis. Excitation conditions, line pairs and rotational speeds are given for the analysis of aluminum (.07–.2%), lead (.3–1.5%), iron (.005–1.5%) and tin (.2–2.0%) in zinc.
Universal Spectrographic Method for the Analysis of Iron and Steel
Authors: Weisberger Sol , Pristera Frank , Reese Earle F.
Published: November 2005

A universal spectrographic method has been developed for the determination of the following elements in iron and steel: Silicon, Manganese, Nickel, Chromium, Cobalt, Molybdenum, Titanium, Niobium (Columbium), Vanadium, Aluminum, Copper, Silver, Lead and Tin. The method has proven itself highly satisfactory in classifying or characterizing samples of iron or steel. It is universal in that it can be applied to any sample of 0.010 gram or larger irrespective of size, shape or previous history.
A Spectrographic Technique for the Determination of Gallium in Micro Samples
Authors: Murt E. M.
Published: November 2005

A spectrographic technique to enhance the sensitivity of gallium determination in micro samples of indium-gallium alloys is described. Use of a helium atmosphere effectively reduces cyanogen band interference with the most sensitive gallium lines, 4172 1A and 4033.0A.
Recording Infrared Spectra for Quantitative Analysis
Authors: Perry John A. , Bain George H. , Traver Ward B.
Published: November 2005

Potential speed in acquisition of data, intrinsic wavelength reproducibility, and permanence make recorded spectra desirable sources of quantitative data. To permit using the Perkin-Elmer Moodel 21 spectrophotometer for quantitative work, optimum operating conditions for recording infrared spectra have been determined in a statistical study. Slits should be set as wide as consistent with analytical requirements but short of causing pen oscillation. Zero transmittance should be set with the help of a transmission reference, such as a screen. Suppression value and mode of slit operation do not significantly affect error. With these procedures, spectra can be recorded with a precision of 0.25% transmittance.
Some Applications of the Micro-Volume Technique to Emission Spectrochemistry and Metallurgy
Authors: Hurwitz J. K.
Published: November 2005

To obtain the necessary data required for the study of segregation and diffusion phenomena in metals and alloys, a rapid quantitative technique has been developed. In this technique, the specimen is moved over a spark discharge while the photographic plate is lowered so that each point in the spectrum corresponds approximately to the analysis of a point on the specimen. A theory has been developed which takes into consideration the measurable instrumental variables and which predicts quantitatively the observed intensities in the spectrum when a region of rapidly changing composition is traversed. The practical significance of these variables is indicated. An example of the analysis of segregates is given, and an outline of the method to be applied to specimens in which diffusion has occurred is described. From an investigation of the sparking-off effect in the spectrochemistry of zinc-base alloys, a procedure was evolved by which this effect can be eliminated.
Use of Commercial Sheet for Spectrochemical Analysis
Authors: Slavin Morris
Published: November 2005

Based on several years' experience, the substitution of commercial sheet film for glass plates is advocated for spectrochemical purposes. Advantages of sheet film are freedom from breakage, ease of cutting and filing, and ability to photograph wide spectral regions in one piece. Commercial emulsions are more uniformly coated and are much more free from blemishes. Holders for glass plates can be used for film with no structural changes. A list of available emulsions which can be used in place of spectroscopic plates is presented.
Spectrochemical Analysis by Means of the D.C. Carbon Arc
Authors: Addink N. W. H. , Dikhoff J. A. M. , Schipper C. , Witmer A. , Groot T.
Published: November 2005

A complete description of the constant temperature arc method of quantitative analysis which has been developed in Eindhoven is given, with tables of the empirically determined K-values reported so that they can be checked in other laboratories. The method consists of completely volatilizing 5 mg. of a powdered sample in a shallow anodic crater of a carbon arc, with the addition of materials to modify the rate of volatilization if required. The line intensities are calibrated and corrections are made by comparison with selected Fe lines, originating from a “standard light source” so as to get comparable analytical results; the calculations required are illustrated by several examples, which indicate the relative accuracy of the method to be approximately 10%.
Factors Influencing Characteristic Vibrational Frequencies of Molecules: Intramolecular Effects
Authors: Lord R. C. , Miller Foil A.
Published: November 2005

This paper is concerned with the intramolecular factors which make a characteristic group frequency vary slightly from one type of compound to another. The factors which are discussed with numerous examples include atomic mass, mechanical coupling, symmetry, electronegativity, conjugation and bond-angle strain.
Flame-Photometric Determination of Dissolved Solids in Water
Authors: Marsh Grace E.
Published: November 2005

The flame photometer has been successfully applied to the direct determination of 30 to 45 p.p.m. calcium, 5 to 15 p p.m. magnesium, 5 to 20 p.p.m. sodium, and 1 to 2 p.p.m. iron in water. Because iron and magnesium determinations are affected by the presence of calcium and sodium, calibration standards were prepared to contain different amounts or one ion in the presence of fixed amounts of the other three. Based on repetitive analyses of three synthetic and three natural samples, repeatability is about 0.1 p.p.m. when an oxy-acetylene flame is used. No sample preparation is needed and a complete analysis takes 30 minutes
Spectrographic Determination of Palladium in Doré Metal
Authors: Tomingas Nicolas , Cooper W. Charles
Published: November 2005

A convenient spectrographic procedure for the determination of small amounts of palladium in Dore metal containing varying amounts of copper and gold is described. Copper in excess of 0.4% produced a marked enhancement of the palladium and silver line intensities, thereby prohibiting the use of a single working curve. A number of working curves were prepared, each corresponding to a definite copper concentration and, in the analysis of a Doré metal sample, the copper-silver intensity ratio served to indicate the position of the proper working curve The influence of gold was significant only when its concentration exceeded 9% The procedure was employed to determine 45 to 800 ppm. of palladium in Doré metal and very much smaller concentrations of palladium (down to 0 05 ppm. in a 3 assay-ton sample) in ores, copper concentrates, blister copper and other metallurgical products.
Analytical Curves in Isotopic Spectral Analysis
Authors: Striganov A. R.
Published: November 2005

It is found that for heavy elements, in the absence of self-absorption, a simple proportionality exists between the relative intensity of spectral lines belonging to different isotopes and the relative concentration of the isotopes. In the case of the lighter elements a simple proportionality is distorted by the different Doppler broadening of the measured lines and as a result of differences between physical properties of the isotopes. In order to establish the character of the relation between line intensity and concentration, the analytical curves were constructed using standard isotopic mixtures of uraniom and hydrogen. Some of the mixtures (U235 + U238) consisted of isotopes whose physical properties were approximately equal, the others (H2 + D2) of isotopes with notably different properties. When consideration was given to background in the spectrum and superposition of isotopic lines, the experimental results were found to be consistent with the derived equation. Thus, in the case of isotopic spectral analysis for obtaining the desired results, it is necessary to standardize the method with the purpose of establishing the character of the dependence between the quantities I1/I2 and C1/C2. The true dependence between these quantities, even in the absence of self-absorption, may be strongly distorted by the mutual superposition of comparative lines and by the background of the spectrum.
The Determination of Parts per Million of Iron in Adipic Acid by Ultraviolet Absorption
Authors: Seeber Richard E. , White Robert G. , Ferber Kelvin H.
Published: November 2005

The near ultraviolet absorption of the FeCl3 complex affords a convenient means of determining iron in adipic acid in the range 0.25–15 ppm

The use of a predominantly alcoholic solvent system obviates the necessity of carefully controlling chloride ion concentration.

Oxidation with H2O2 assures that all the iron is present in the ferric state.

The method may be extended to other alcohol soluble substances having sufficient transparency in the near ultraviolet.

High purity adipic acid (hexanedioic acid) must contain less than 3 ppm iron. Analysis for iron at this level by conventional colorimetric methods is not entirely satisfactory. The preliminary ashing of the sample is time consuming and there is an inherent lack of precision due to a high reagent blank.

Since adipic acid contains no chromophores which might give rise to near ultraviolet absorption, a direct spectrophotometric determination of iron was suggested in view of the intense absorbance of iron ion complexes.
Atomic Collision Processes Occurring in Gas Discharges
Authors: Biondi Manfred A.
Published: November 2005

Some atomic collision processes which influence the emission of radiation from gas discharge sources are discussed briefly The processes are divided into the following categories (1) Excitation of an atom by electron impact, (a) direct (from the ground state) and (b) indirect (from an excited state); (2) Collisions between excited atoms; (3) Transfer of excitation, and (4) Electron-ion recombination The relative importance of these reactions is discussed and possible consequences with regard to spectrochemical analyses are considered.
The Adaptation of a Commercial Double-Beam Infrared Spectrophotometer for Use with a Grating
Authors: Mattraw H. C. , Landis F. P.
Published: November 2005

A 60 line/mm Bausch and Lomb grating has been installed in a Baird Infrared Spectrophotometer in place of all prisms to cover the 2 to 26 micron range of the instrument No changes were made in the optical system for the 2 to 10 micron region. To avoid overlapping of higher orders on the longer wave length first order spectrum, one small mirror was replaced by a crystal of MgO An alternate method, referred to as negative filtering, is presented for the elimination of overlapping orders and may be used with the double-beam instruments. The existing scanning equipment was used with the following modifications. (1), a mechanical linkage was tied to the existing Littrow mirror drive to rotate the grating and (2), new cams were substituted for the prism cams to provide linear wave length scans with the grating. One cam covers 6 microns of any region of the spectrum before resetting the grating, while the second cam can be used to obtain four times the dispersion of the first cam.
A New Density Function Based on the Poisson Distribution for the Characteristic Curve and Linear at Very Low Densities
Authors: Arrak Arno
Published: November 2005

It is suggested that densitometric data be represented in terms of the density function

[Formula: see text]

which differs from the corresponding Seidel (Baker-Sampson) function2 by the addition of the constant δ Use of log ω has distinct advantages if density measurements have to be made in the toe part of the H and D curve The constant δ bears a definite relationship to the inertia threshold The fact that the existence of the inertia threshold can be taken into account considerably improves the linearity of the function at very low densities Relationship of the suggested density function to the characteristic curve based upon a Poisson distribution is discussed and a practical formula for calculating approximate values of δ will be given. Linearization of the H and D curve is possible down to densities where deviations from Beer's law for reduced silver set in, and except for such photometric effects the new characteristic curve can be extrapolated down to inertia threshold Although use of log ω instead of simple density or the Seidel density may be cumbersome in routine applications, it should become an important tool to the research man using the toe part of the H and D curve for measurment of densities.
Three New Spectrophotometers
Authors: Lüscher E.
Published: November 2005

Spectrophotometers are being used more frequently and for more applications in industrial and research laboratories. Therefore it becomes more important to build various spectrophotometers for specialized applications. This presentation describes three new commercial spectrophotometers, an interference filter colorimeter (range 400 to 700 mμ), a prism spectrophotometer (range 300 to 750 mμ) and a silica prism – glass prism – grating spectrophotometer (range 210 to 5000 mμ).
The Effect of Absorption on the Characteristic Curve of Thick Emulsions
Authors: Arrak Arno
Published: November 2005

A general theorem is presented which makes it possible to express the probability of a certain fraction of grains of an emulsion of finite thickness d becoming developable as a result of an exposure E, provided that the emulsion absorbs light exponentially according to beer's law, and provided also that a power series expression is available for the probability of a single grain becoming developable as a result of the same exposure The theorem allows testing of the relation between exposure and developability of grains without the necessity of grain counts on single grain layer emulsions. It is applied to the specific case of the Poisson distribution of exposure to obtain a power series representation for the Poisson distribution to exposure in thick emulsions. The consequences of this formula are to be worked out in a future paper. The usefulness of the theorem is not restricted to the absorption of light quanta only, for it applies to any particles whatsoever which are absorbed according to Beer's law in a medium where photochemical or nuclear reactions are produced by the bombarding radiation
Suppression of Cyanogen Bands for the Spectrographic Analysis of Erbium Oxide
Authors: Hammaker E. M. , Pope G. W. , Ishida Y. G. , Wagner W. F.
Published: November 2005

The suppression of cyanogen bands from direct current arc spectra by using atmospheres of argon, helium, and carbon dioxide, and binary mixtures of these gases with oxygen has been investigated. Analytical working curves for the determination of dysprosium, thulium, and holmium in erbium oxide have been prepared from spectra of samples arced in an atmosphere of 80% argon – 20% oxygen. Cyanogen bands were eliminated to permit the use of sensitive lines in these regions; background intensity was also reduced.
Spectrographic Determination of Scandium, Yttrium, and the Rare Earths in Thorium
Authors: Faris J. P.
Published: November 2005

A spectrographic procedure for the determination of scandium, yttrium, and the rare earths in thorium is described. These elements were separated from thorium dissolved in nitric acid using Dowex 1 anion resin and subsequently analyzed by the Copper Spark Method. Quantitative recoveries of known amounts added to thorium were obtained for Sc, Y, Ce, Sm, Eu, Gd, Dy, Er, and Yb. The values for lanthanum averaged about 90% of the amount added.
Polyethylene Capillary Tubes as Micro Liquid Cells for Infrared Spectroscopy
Authors: Molnar W. S. , Yarborough V. A.
Published: November 2005

A novel and simple technique for obtaining infrared spectra of microgram quantities of liquid samples is described. The minute liquid sample is enclosed within a micro capillary tube of polyethylene and the spectrum is recorded with a commercial infrared microspectrometer. A modified cold-trap used with the polyethylene micro-capillaries for sampling minute amounts of liquids eluted from gas chromatographic equipment is also described.
The Spectrographic Analysis of Zircaloys
Authors: Wheat J. Allen
Published: November 2005

Tin, iron, chromium and nickel can be determined as alloying constituents in Zircaloys by the point-to-plane spark method of spectrographic analysis. Under appropriate conditions this method can be applied to the analysis of rolled sheet and thin-walled tubing as well as to the analysis of masssive blocks Coefficients of variation are four per cent for tin, chromium and nickel, and six per cent for iron.
Recent Developments in NBS Spectrographic Standard Samples of Iron-Base Alloys
Authors: Michaelis Robert E.
Published: November 2005

Eight new ingot iron and low-alloy steel spectrographic standards, which are certified for 17 elements, including carbon and phosphorus, recently have been made available by the National Bureau of Standards. The standards are in the form of rods 7/32 in. in diameter and 4 in. long, and disks 1 ¼ in. in diameter and ¾ in. thick. The compositions of these standards are given in a table. Also shown in tables are the final certificate values for two groups of stainless steel spectrographic standards issued several years ago but which have had several elements added to the original certificates. Standard samples for x-ray fluorescence analysis of stainless steel (six standards) and tool steel (six standards) have been provided in the form of disks 1 ¼ in in diameter and ¼ in. thick
A Routine Flame-Photometric Determination of Organic Chloride
Authors: Marsh Grace E.
Published: November 2005

The flame photometer has been successfully applied to the quantitative determination of 0.1% to 1.0% of organic chloride. Copper is added to the sample and the copper chloride emission band at 436 mμ is measured. The method is much faster than the chemical method, and precision is as good when the qualitative composition of the sample is known.
Quantitative Spectrochemical Methods of Broad Applicability
Authors: Jaycox Edwin K.
Published: November 2005

One important factor restricting the applications of the emission spectrograph to the quantitative analysis of any and all kinds of materials has been the limited availability of suitable analyzed standard samples in some required areas of analysis. Techniques are described wherein available standard samples are used in combination with synthetic laboratory-made standards and spectroscopic buffers These methods utilize a single set of three to six standards for the analysis of each class of alloys For example, one set of standards is used for the analysis of lead-base, lead-tin-base (solders) and tin-base alloys; and in like manner a single set of standards for each of copper-base, aluminum-base, zinc-base, and magnesium-base alloys, and for ceramics.

The availability of standard samples, their usefulness, and their limitations are discussed Data are presented to indicate the precision and accuracy of the methods as applied to various base materials.
Efficient Continuous A.C. Arc
Authors: Rozsa J. T. , Uguccini O. W.
Published: November 2005

While d.c. arc excitation has been conventional for many types of analysis, the erratic volatilization characteristics have always demanded rigidly standardized methods and an unnecessarily high amount of preliminary development. A high amperage a c. arc ( Sustaining Arc) has been developed for maximum output at high electrical efficiency. The unit exhibits the greatest improvement for heavy or refractory elements. In general, background is reduced up to 20%, sensitivity improved by 10 to 30%, and reproducibility enhanced by 30 to 100% over a wide range of materials encountered in a commercial laboratory.
KBr Disk Technique for Infrared Microanalysis with Freeze Drying of Samples Soluble in Organic Solvents but Insoluble in Water
Authors: Schwarz H. P. , Childs R. C. , Dreisbach L. , Mastrangelo S. V. , Kleschick A.
Published: November 2005

The potassium bromide disk technique has been adapted for quantitative microanalysis of compounds which are soluble in organic solvents, but insoluble in water. The principal improvements of the technique comprise exclusive use of freeze drying for preparation of suspensions of samples in solid potassium bromide, avoidance of contamination during the sample preparation, and lubrication of the die with graphite The present experimental data indicate that the disk technique can be used for quantitative infrared microanalysis of binary mixtures of complex organic compounds.
A Method for the Determination of Trace Impurities
Authors: Pittwell L. R.
Published: November 2005

Traces of impurity may be determined by solution of the sample followed by complete coprecipitation with a carrier under conditions such that the original matrix is not precipitated The impurity is then determined by d c. arc spectroscopy, using the carrier as internal standard The method is of use for the determination of traces too low for normal methods, and for the analysis of trace standards for conventional metallic sample methods where no purely chemical method exists.
A Mathematical Method of Comparing Spectrochemical Results
Authors: Strasheim A. , Keddy R. J.
Published: November 2005

A mathematical method is described for comparing spectrochemical results, by calculating and comparing the areas of the contour ellipses which surround the points of density scatter diagrams. By employing this comparison method, it was found that, when using lithium carbonate as a buffer for plant ash analysis, the best results are obtained when the arc is burned with a surrounding air stream, as first suggested by Stallwood, but with a constant current generator used as the energy source.
Enhanced Precision in the Quantometric Determination of Phosphorus in Low-Alloyed Steels
Authors: Lounamaa Niilo
Published: November 2005

By the use of both a constant exposure time and a reference line in quantometric analysis, a high precision can be attained despite a disadvantageous line-to-background ratio. Phosphorus contents in the range from 0.01 to 0.07 per cent in steels can be determined with a coefficient of variation of 2 to 4 percent
An Infrared Spectrophotometer for the Organic Chemist
Authors: Van Williams Zandt
Published: November 2005

In the last decade there has been tremendous growth in the application of both infrared and ultraviolet spectrometry by the organic chemist. In each case, single-beam instruments appeared first, to be followed by the more versatile double-beam spectrophotometers. Because of the simplicity of ultraviolet spectrometry, both instruments are used in this field. In the infrared, however, the requirements are such that the double-beam instrument displaced the single-beam type even though it was more expensive. Because of this cost, infrared use has been limited to larger sites using central group, specialized personnel and the equipment has not been available to the chemist at the bench

In order to meet the chemist's need directly, there has been developed an inexpensive, reliable, double-beam infrared spectrophotometer The significance of this development to the chemist is described and illustrated.