bluuebunny/crossref_metadata_2025 huggingface dataset:
An Electrochemical Impedance Spectroscopic Study of the Passive State on AISI 304 Stainless Steel
Authors: Fattah-alhosseini A. , Taheri Shoja S. , Heydari Zebardast B. , Mohamadian Samim P.
Published: February 2011

The passivity and protective nature of the passive films are essentially related to ionic and electronic transport processes, which are controlled by the optical and electronic properties of passive films. In this study, the electrochemical behavior of passive films anodically formed on AISI 304 stainless steel in sulfuric acid solution has been examined using electrochemical impedance spectroscopy. AISI 304 in sulphuric acid solution is characterized by high interfacial impedance, thereby illustrating its high corrosion resistance. Results showed that the interfacial impedance and the polarization resistance () initially increase with applied potential, within the low potential passive. However, at a sufficiently high potential passive ( V), the interfacial impedance and the polarization resistance decrease with increasing potential. An electrical equivalent circuit based on the impedance analysis, which describes the behavior of the passive film on stainless steel more satisfactorily than the proposed models, is presented.
Characterization and In Silico Analysis of Pregnancy-Associated Glycoprotein-1 Gene of Buffalo (Bubalus bubalis)
Authors: A. Jerome , Singh S. K. , Agarwal S. K. , Saini Mohini , Raut Ashwin
Published: February 2011

Pregnancy-Associated Glycoproteins (PAGs) are trophoblastic proteins belonging to the Aspartic proteinase family secreted by different placental cells of many mammalian species. They play a pivotal role in placentogenesis, foetomaternal unit remodeling, and implantation. The identification of the genes encoding those proteins will be helpful to unravel the intricate embryogenomic functions during pregnancy establishment. Considering importance of these proteins, the present study was undertaken to characterize the pregnancy associated glycoprotein-1 gene of buffalo. An 1181 base pairs buffalo Pregnancy-Associated Glycoprotein PAG-1 gene was PCR amplified from the RNA obtained from the fetal cotyledons. BLAST analysis of the buffalo PAG-1 sequence retrieved a total of 20 cattle, 5 goat, and 4 sheep PAG sequences, exhibiting more than 80% similarity. Buffalo PAG-1 gene contained an uninterrupted open reading frame of 1140 base pairs encoding 380 amino acids that possess a 15 amino acid signal peptide and mature peptide of 365 amino acids. The phylogenetic study of the buffalo PAG-1 gene revealed buffalo PAG-1 is more related to cattle, goat, and sheep PAG-1 sequences. By this study characterization of buffalo PAG-1 gene and its evolutionary relationship was deduced for the first time.
Hereditary Diffuse Gastric Cancer: Multidisciplinary Case Report with Review of the Literature
Authors: Wilcox Rebecca , Perpich Melody , Noffsinger Amy , Posner Mitchell C. , Cooper Kumarasen
Published: February 2011

Hereditary diffuse gastric cancer (HDGC) is a rare, inherited cancer syndrome with at least one fourth of HDGC patients having an autosomal dominantly inherited mutation of CDH1 (E-Cadherin). Penetrance is relatively high (70–80% lifetime risk for gastric cancer). It is important for pathologists to recognize the syndrome's phenotype in early gastric lesions: patchy intramucosal signet ring cells often associated with pagetoid spread. Due to the insidious nature of this lesion, surveillance is limited and currently prophylactic gastrectomy is an option chosen by many HDGC patients. We present a case report from a multidisciplinary team of authors with a review of the literature that includes the updated guidelines for CDH1 genetic testing.
Cardiorenal Syndrome Type 4—Cardiovascular Disease in Patients with Chronic Kidney Disease: Epidemiology, Pathogenesis, and Management
Authors: Pateinakis Panagiotis , Papagianni Aikaterini
Published: February 2011

The term cardiorenal syndrome refers to the interaction between the heart and the kidney in disease and encompasses five distinct types according to the initial site affected and the acute or chronic nature of the injury. Type 4, or chronic renocardiac syndrome, involves the features of chronic renal disease (CKD) leading to cardiovascular injury. There is sufficient epidemiologic evidence linking CKD with increased cardiovascular morbidity and mortality. The underlying pathophysiology goes beyond the highly prevalent traditional cardiovascular risk burden affecting renal patients. It involves CKD-related factors, which lead to cardiac and vascular pathology, mainly left ventricular hypertrophy, myocardial fibrosis, and vascular calcification. Risk management should consider both traditional and CKD-related factors, while therapeutic interventions, apart from appearing underutilized, still await further confirmation from large trials.
Three Patients with Viral Breakthrough during Pegylated Interferon Alpha-2b and Ribavirin Therapy: A Case Series
Authors: Kon Daigo , Goto Takashi , Miura Kouichi , Ohshima Shigetoshi , Shibuya Tomomi , Kataoka Ei , Sato Wataru , Dohmen Takahiro , Anezaki Yumiko , Ishii Hajime , Yamada Ikuhiro , Kamada Kentaro , Ohnishi Hirohide
Published: February 2011

Introduction

A viral breakthrough occurs when a patient achieves a response while on interferon (IFN) therapy and then loses the response despite continued IFN therapy. The cause of viral breakthroughs is not well understood. We encountered three cases with viral breakthrough during treatment with pegylated interferon (PEG-IFN) and ribavirin (RBV).

Case presentation

The three cases were all late virological responders. They did not express anti-IFN alpha-2b antibodies after PEG-IFN and RBV therapy. We analyzed amino acid substitutions of core 70, core 91, and interferon sensitivity-determining region (ISDR), which significantly influence sustained virological response (SVR). Their amino acid substitutions of core 91 were mutant in two cases. Amino acid substitutions of ISDR were wild pattern in two cases. PEG-IFN adherence was above 80% in three cases, and RBV adherence was below 80% in two cases.

Conclusion

During PEG-IFN and RBV therapy, we should watch for viral breakthrough in late virological responders with mutant type of amino acid substitutions of core 91, wild pattern of amino acid substitution of ISDR, and decrease of RBV adherence. Viral breakthrough is an important problem in PEG-IFN and RBV therapy for chronic hepatitis C. Therefore, it should be investigated more thoroughly in more cases.
Ceftobiprole: An Emerging Therapeutic Option for Resistant and Complicated Infections
Authors: Reygaert Wanda C.
Published: February 2011

Ceftobiprole is a new parenterally administered fifth generation cephalosporin which has been shown to have antimicrobial activity against a broad range of bacteria, and specifically against methicillin-resistant Staphylococcus aureus (MRSA) in complicated skin and skin structure infections (cSSSIs), with a cure rate non-inferior to vancomycin and ceftazidime. It has increased stability against β-lactamases and an increased affinity for PBP2’ in MRSA strains. Ceftobiprole has shown a low tendency to select for resistance, and because it is excreted mainly in the urine, a low potential for adverse drug interactions. It has been shown to cause few mild to moderate adverse effects in patients. The broad-spectrum of activity makes it an excellent choice for initial monotherapy in cSSSIs. There is also promise for use in all types of pneumonia, and synergistic possibilities with aminoglycoside and fluoroquinolone drugs. It is awaiting final approval by the FDA.
Long-Acting Injectable naltrexone for the Management of patients with Opioid Dependence
Authors: Kjome Kimberly L. , Moeller F. Gerard
Published: February 2011

Opioid dependence is a condition with serious clinical ramifications. Treatment has focused on detoxification, agonist therapy with methadone or buprenorphine, or remission maintenance with the opioid antagonist, naltrexone. Treatment with oral naltrexone has been limited by poor treatment adherence and relapse. Studies with long-acting formulations have shown increased treatment adherence. Extended-release injectable naltrexone has been used for the treatment of alcohol dependence, and has recently received an indication for treatment of opioid dependence from the US Food and Drug Administration. Dosing occurs once monthly and existing data with long-acting naltrexone supports efficacy of treatment for opioid dependence; however published data is sparse. Treatment with long-acting naltrexone should be monitored for hepatotoxicity, and patients should be made aware of increased risk of overdose with administration of opioids during and immediately after discontinuation of long-acting naltrexone.
Probucol Attenuates Cyclophosphamide‐induced Oxidative Apoptosis, p53 and Bax Signal Expression in Rat Cardiac Tissues
Authors: Asiri Yousif A.
Published: February 2011

Cyclophosphamide (CP) is a widely used drug in cancer chemotherapy and immunosuppression, which could cause toxicity of the normal cells due to its toxic metabolites. Probucol, a cholesterol‐lowering drug, acts as potential inhibitor of DNA damage and shows to protect against doxorubicin‐induced cardiomyopathy by enhancing the endogenous antioxidant system including glutathione peroxidase, catalase and superoxide dismutase. This study examined the possible protective effects of probucol, a lipid‐lowering compound with strong antioxidant properties, against CPinduced cardiotoxicity. This objective could be achieved through studying the gene expression‐based on the possible protective effects of probucol against CP‐induced cardiac failure in rats. Adult male Wistar albino rats were assigned into four treatment groups: Animals in the first (control) and second (probucol) groups were injected intraperitoneally with corn oil and probucol (61 mg/kg/day), respectively, for two weeks. Animals in the third (CP) and fourth (probucol plus CP) groups were injected with the same doses of corn oil and probucol (61 mg/kg/day), respectively, for one week before and one week after a single dose of CP (200 mg/kg, I.P.). The p53, Bax, Bcl2 and oxidative genes signal expression were measured by real time PCR. CP‐induced cardiotoxicity was clearly observed by a significant increase in serum creatine phosphokinase isoenzyme (CK‐MB) (117%), lactate dehydrogenase (LDH) (64%), free (69%) and esterified cholesterol (42%) and triglyceride (69%) compared to control group. In cardiac tissues, CP significantly increases the mRNA expression levels of apoptotic genes, p53 with two‐fold and Bax with 1.6‐fold, and decreases the anti‐apoptotic gene Bcl2 with 0.5‐fold. Moreover, CP caused downregulation of antioxidant genes, glutathione peroxidase, catalase, and superoxide dismutase and increased the lipid peroxidation and decreased adenosine triphosphate (ATP) (40%) and ATP/ADP (44%) in cardiac tissues. Probucol pretreatment not only counteracted significantly the CP‐induced increase in cardiac enzymes and apoptosis but also induced a significant increase in mRNA expression of antioxidant enzymes and improved ATP, ATP/ADP, glutathione (GSH) in cardiac tissues. In conclusion, data from the present study suggest that probucol prevents the development of CP‐induced cardiotoxicity by a mechanism related, at least in part, to its ability to increase mRNA expression of antioxidant genes and to decrease apoptosis in cardiac tissues with the consequent improvement in mitochondrial oxidative phosphorylation and energy production.
Aspartyl‐(asparaginyl) β‐Hydroxylase, Hypoxia‐Inducible Factor‐1α and Notch Cross‐Talk in Regulating Neuronal Motility
Authors: Lawton Margot , Tong Ming , Gundogan Fusun , Wands Jack R. , de la Monte Suzanne M.
Published: February 2011

Aspartyl‐(Asparaginyl)‐β‐Hydroxylase (AAH ) promotes cell motility by hydroxylating Notch. Insulin and insulin‐like growth factor, type 1 (IGF‐I) stimulate AAH through Erk MAP K and phosphoinositol‐3‐kinase‐Akt (PI3K‐Akt). However, hypoxia/oxidative stress may also regulate AAH . Hypoxia‐inducible factor‐1alpha (HIF‐1α) regulates cell migration, signals through Notch, and is regulated by hypoxia/oxidative stress, insulin/IGF signaling and factor inhibiting HIF‐1α (FIH) hydroxylation. To examine cross‐talk between HIF‐1α and AAH , we measured AAH , Notch‐1, Jagged‐1, FIH, HIF‐1α, HIF‐1β and the hairy and enhancer of split 1 (HE S‐1) transcription factor expression and directional motility in primitive neuroectodermal tumor 2 (PNET2) human neuronal cells that were exposed to H2O2 or transfected with short interfering RNA duplexes (siRNA) targeting AAH , Notch‐1 or HIF‐1α. We found that: (1) AAH , HIF‐1α and neuronal migration were stimulated by H2O2; (2) si‐HIF‐1α reduced AAH expression and cell motility; (3) si‐AAH inhibited Notch and cell migration, but not HIF‐1α and (4) si‐Notch‐1 increased FIH and inhibited HIF‐1α. These findings suggest that AAH and HIF‐1α crosstalk within a hydroxylation‐regulated signaling pathway that may be transiently driven by oxidative stress and chronically regulated by insulin/IGF signaling.
The vulnerable living order: human rights and the environment in a critical and philosophical perspective
Authors: Grear Anna
Published: February 2011

One of the problems encountered in bringing the discourses of human rights and environment together concerns the philosophical foundations lying beneath certain closures of liberal (legal) theory. Linking a destructive mind/body split to the destructive relationship between ‘humanity’ and the ‘environment’, the author argues that a critical analysis of legal anthropomorphism reveals a fundamental failure of representation at its heart, in so far as the ‘human being’ qua ‘human being’ is not fully included in it. On further analysis human beings can be seen to be functionally united with non-human animals and the environment in a form of conceptual exclusion linked to certain violences of capitalism. The author reflects upon the thought of Merleau-Ponty, offering it as a basis for an alternative philosophical lens through which to understand the relationship between human rights and the environment, one uniting them in the ontological vulnerability of the living order itself. Human beings, in this light, are not the hyper-rational subjects of liberal legal theory acting upon an objectified, exploitable ‘nature’. We are, rather, part of a living tissue of interconnection bearing profound implications for ethics, epistemology and legal theory.
A numerical study of mountain waves in the upper troposphere and lower stratosphere
Authors: Mahalov A. , Moustaoui M. , Grubišić V.
Published: February 2011

Abstract. A numerical study of mountain waves in the Upper Troposphere and Lower Stratosphere (UTLS) is presented for two Intensive Observational Periods (IOPs) of the Terrain-induced Rotor Experiment (T-REX). The simulations use the Weather Research and Forecasting (WRF) model and a microscale model that is driven by the finest WRF nest. During IOP8, the simulation results reveal presence of perturbations with short wavelengths in zones of strong vertical wind shear in the UTLS that cause a reversal of momentum fluxes. The spectral properties of these perturbations and the attendant vertical profiles of heat and momentum fluxes show strong divergence near the tropopause indicating that they are generated by shear instability along shear lines locally induced by the primary mountain wave originating from the lower troposphere. This is further confirmed by results of an idealized simulation initialized with the temperature and wind profiles obtained from the microscale model. For IOP6, we analyse distributions of O3 and CO observed in aircraft measurements. These show small scale fluctuations with amplitudes and phases that vary along the path of the flight. Comparison between these fluctuations and the observed vertical velocity show that the behavior of these short fluctuations is due not only to the vertical motion, but also to the local mean vertical gradients where the waves evolve, which are modulated by larger variations. The microscale model simulation results shows favorable agreement with in situ radiosonde and aircraft observations. The high vertical resolution offered by the microscale model is found to be critical for resolution of smaller scale processes such as formation of inversion layer associated with trapped lee waves in the troposphere, and propagating mountain waves in the lower stratosphere.
Iodine monoxide at a clean marine coastal site: observations of high frequency variations and inhomogeneous distributions
Authors: Commane R. , Seitz K. , Bale C. S. E. , Bloss W. J. , Buxmann J. , Ingham T. , Platt U. , Pöhler D. , Heard D. E.
Published: February 2011

Abstract. The first in situ point observations of iodine monoxide (IO) at a clean marine site were made using a laser-induced fluorescence instrument deployed at Mace Head, Ireland in August 2007. IO mixing ratios of up to 49.8 pptv (1 s) were observed at day-time low tide, well in excess of previous observed spatially-averaged maxima. A strong anti-correlation of IO with tide height was evident and the high time resolution of the observations showed IO peaked in the hour after low tide. The temporal delay in IO peak compared to low tide has not been observed previously but coincides with the time of peak aerosol number previously observed at Mace Head. A long path-differential optical absorption spectroscopy instrument (with a 2 × 6.8 km folded path across Roundstone Bay) was also based at the site for 3 days during the point measurement observation period. Both instruments show similar temporal trends but the point measurements of IO are a factor of ~6–10 times greater than the spatially averaged IO mixing ratios, providing empirical evidence of the presence of inhomogeneities in the IO mixing ratio near the intertidal region.
Deriving the effect of wind speed on clean maritime aerosol optical properties using the A-Train satellites
Authors: Kiliyanpilakkil V. P. , Meskhidze N.
Published: February 2011

Abstract. Relationship between "clean marine" aerosol optical properties and ocean surface wind speed is explored using remotely sensed data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on board the AQUA satellite. Detailed data analyses are carried out over 15 regions selected to be representative of different areas of the global ocean for the time period from June 2006 to June 2010. Based on remotely sensed optical properties the CALIPSO algorithm is capable of discriminating "clean marine" aerosols from other types often present over the ocean (such as urban/industrial pollution, desert dust and biomass burning). The global mean optical depth of "clean marine" aerosol at 532 nm (AOD532) is found to be 0.052 ± 0.038. The mean layer integrated volume depolarization ratio of marine aerosols is 0.016 ± 0.012, the value representative of sea salt crystals. Integrated attenuated backscatter and color ratio of marine aerosols at 532 nm were obtained to be 0.003 ± 0.002 sr−1 and 0.530 ± 0.149, respectively. A logistic regression between AOD532 and 10-meter surface wind speed (U10) revealed three distinct regions. For surface winds lower than 4 m s−1, the mean CALIPSO-derived AOD532 is found to be 0.02 ± 0.003 with little dependency on the surface wind speed. For surface winds from 4 m s−1 to 12 m s−1, representing the dominant fraction of all available data, marine aerosol optical depth is linearly correlated with the U10, with a slope of 0.0062 s m−1. In this intermediate wind speed region, the AOD532 vs. U10 regression derived here is comparable to previously reported relationships. At very high wind speed values (U10 > 18 m s−1), the AOD532-wind speed relationship showed a tendency toward leveling off, suggesting the existence of some maximum value for maritime AOD. Results of our calculations suggest that considerable improvements to both optical properties of marine aerosols and their production mechanisms can be achieved by discriminating "clean marine" aerosols (or sea salt particles) from all other types of aerosols present over the ocean.
Multi-methodical realisation of Austrian climate maps for 1971–2000
Authors: Hiebl J. , Reisenhofer S. , Auer I. , Böhm R. , Schöner W.
Published: February 2011

Abstract. Constantly changing climate, the availability of a higher resolved digital elevation model and further development of geostatistical interpolation methods gave reason for updating the most frequently demanded climate maps out of the Austrian digital climate atlas from 1961–1990 to 1971–2000. To achieve a station density as high as possible, data from eleven national and foreign institutes were collected and gap-filled. According to the climate parameter, different geostatistical interpolation methods (including regionalised multilinear regressions, geographically weighted regressions and curve fitting to base parameter) were applied. The resultant 17 grids concern 30-year-means of air temperature, precipitation and snow parameters as well as derived indices. They are now available for a variety of scientific and planning purposes.
Instrument of collection of data for the attendance to the aged one in the of health the family program
Authors: Porto Maria Luiza Lucena , Nóbrega Maria Miriam Lima
Published: February 2011

ABSTRACTStudy of the methodological type that had as objective the construction and validation of an instrument of collection of data for the attendance to the aged one in the Health of the Family Program, anchored in the Theory of the Basic Needs of the Human Beings of Horta. For construction of instrument, used it literature specialized of area of nursing gerontology/geriatric, for identification of manifestations of necessities human beings basic in aged, that they had been submitted the content validation, to nurses of the area, being used in the construction of the instruments alone the manifestations that had presented weighed mean ³0.80. In the choice of the format and structure of the instrument, opted if for the use of the evaluation functionary, cognitive evaluation, evaluation of the partner-familiar situation and the evaluation of the basic necessities of care of the aged one. Descriptors: nursing; basic need; care; aged; aging.RESUMOEstudo do tipo metodológico que teve como objetivo a construção e validação de um instrumento de coleta de dados para o atendimento ao idoso cadastrado no Programa de Saúde da Família, ancorado na Teoria das Necessidades Humanas Básicas de Horta. Na construção do instrumento, utilizou-se a literatura especializada da área de enfermagem gerontogeriátrica, e para a identificação das manifestações das necessidades humanas básicas no idoso, estas foram submetidas à validação de conteúdo, por enfermeiras da área, sendo utilizada na construção do instrumento só as manifestações que apresentaram média ponderada ³0.80. Na escolha do formato e estrutura do instrumento, optou-se pela utilização da avaliação funcional, avaliação cognitiva, avaliação da situação sócio-familiar e a avaliação das necessidades básicas de cuidado do idoso. Descritores: enfermagem; necessidade básica; cuidado; idoso; envelhecimento.RESUMENEstudio de tipo metodológico que tuvo como objetivo la construcción y la validación de un instrumento de recolección de datos para la atención de ancianos en el Programa de Salud de la Familia, basado en la teoría de las Necesidades Humanas Básicas de Horta. Para la construcción del instrumento, fue utilizada la literatura especializada del área de enfermería gerontología/geriátrica, para la identificación de manifestaciones de las necesidades humanas básicas en el anciano; estas fueron sometidas a la validación de contenido, por enfermeras del área, siendo utilizada en la construcción del instrumento solamente las manifestaciones que presentaron media ponderada ³0.80.  En la elección del formato y de la estructura del instrumento, se optó por la utilización de la evaluación funcional, la evaluación cognoscitiva, la evaluación de la situación socio-familiar y la evaluación de las necesidades básicas del cuidado del anciano. Descriptores: enfermería; necesidad básica; cuidado; anciano; envejeciendo.
Aging of Stretched Rubber
Authors: Kelly Arthur , Taylor Bert S. , Jones Webster N.
Published: February 2011

Sunlight aging under tension of many compounds including the following has been investigated: tire tread shoe upper, tube stocks, golf ball thread, jar rubber, solid tire, bathing cap stock, channel rubber. With some of these stocks the sunlight aging as been compared with unstretched samples by Geer oven, Bierer bomb, and ultra-violet light methods. The stretching of the test strips accelerates deterioration in sunlight, ultra-violet light, and Geer oven. Stretched samples have not yet been tested in the Bierer bomb. The rate of deterioration was not proportional to the degree of stretch in any of the stocks in the early stages of exposure. In sunlight there is a critical elongation for each stock at which the deterioration progresses more rapidly than at any other in the early stages of aging. No direct relationship was found between the results of sunlight aging and the other methods employed. Stretched strips aged in ultra-violet light were found to give softer stress-strain curves than the unaged samples, whereas sunlight aging under the same conditions stiffens the stress-strain curve.
Activity of Certain Aryl-Substituted Biguanides as Accelerators of Vulcanization
Authors: Smith G. B. L. , Weiss A. J.
Published: February 2011

Aryl-substituted biguanides are rubber vulcanization accelerators of moderate activity. The relation between the chemical constitution of the substituted radicals and the activity of the biguanides is, in general, about the same as found by other investigators for other types of accelerators. α-o-Tolylbiguanide has a fairly great activity in certain commercial rubber stocks.
Conversion of Rubber into Thermoplastic Products with Properties Similar to Gutta-Percha, Balata, and Shellac. II—Chemistry of the Reaction
Authors: Fisher Harry L. , McColm Eugene M.
Published: February 2011

The shellac-like products formed by the action of organic sulfonic acids on rubber have been studied chiefly. After purification the chief constituent is found to be a hydrocarbon with the same empirical formula as that of rubber, C5H8, and it is 55 to 60 per cent as unsaturated as the rubber hydrocarbon. Addition products of hydrogen chloride and hydrogen bromide have been prepared. Vulcanization with sulfur gives a maximum combined-sulfur content of about 21 per cent, corresponding to 57 per cent unsaturation as compared with rubber. Oxidation, hydrogenation, bromination, nitration, etc., have also been studied. The purified hydrocarbon is white and is completely soluble in the rubber solvents and insoluble in alcohol, acetone, etc. It is much more stable toward heat than rubber. The gutta-percha and balata types are only partially soluble, but analyses, yields, etc., indicate that they consist of similar isomeric hydrocarbons.
Methods for the Purification of Rubber Hydrocarbons
Authors: Pummerer Rudolf , Miedel Hermann
Published: February 2011

The various methods which have been used for preparing the rubber hydrocarbon in a pure state are discussed critically. The authors show that Harries' method of acetone extraction and precipitation of the rubber from benzene solution gives a product which still contains a small proportion of protein and sugars. Fractional precipitation gives a better product, but it is not entirely free from nitrogen. Purification with methyl alcoholic potash removes all the nitrogen, but the last traces of the alkali are difficult to remove. The diffusion method is then described. This gives an analytically pure rubber hydrocarbon. In scientific investigations of rubber, many research workers have heretofore given too little attention to the obvious problem of isolating in a pure state the rubber hydrocarbon, or perhaps the several hydrocarbons in the natural raw product: It is timely to gather together and evaluate the various methods useful for this purpose.
Effect of High vs. Low Sulfur in Vulcanizing Reclaim
Authors: Cartlidge R. E. , Snyder H. L.
Published: February 2011

To obtain the optimum results in curing compounded stocks containing whole tire reclaim, a minimum of 2.0 and a maximum of 2.5 per cent sulfur are required. This range of sulfur content, based on the total weight of reclaim in the compound besides the 4 per cent added for curing the crude rubber present, gives the flattest and longest curing range in conjunction with the highest physical qualities. Three per cent of sulfur on the straight reclaim-sulfur mix gives the maximum physical properties.
The Mercury Vapor Arc Lamp: Its Uses in a Rubber Factory
Authors: Nagle P. G.
Published: February 2011

Ultra-violet light has recently been brought very prominently into public notice owing to its successful application by the medical profession to the cures of various ailments, and skin diseases in particular; there are, however, many possibilities of its increased application to various industries. First noticed some 200 years ago, actinic rays were found to produce certain chemical changes in many substances, particularly silver salts; and the artificial production of light containing these rays became a matter of some little importance. Earlier sources for their production were burning magnesium, incandescent calcium oxides, the electric arc between carbon poles, the iron arc, tungsten arc, aluminium and silica arc, etc. In 1901 a mercury vapor lamp was produced, depending upon the formation of an arc between two columns of mercury in an exhausted glass tube. This lamp, while giving a certain amount of ultra-violet light, lost much of its actinic value owing to the absorption of the greater part of these rays by the glass of the tube, and the main use of the lamp was as a convenient source of monochromatic green light. The substitution of a quartz tube for glass was found to allow a vastly greater amount of ultra-violet light to be transmitted. A great improvement has since been obtained by the production of a lamp giving an arc between mercury columns at ordinary atmospheric pressure. Such a lamp was used in obtaining information which is incorporated in this paper; the actual lamp being a Kelvin Bottomley and Baird “fugitometer,” working at 460 volts d. c. The spectrum given by mercury vapor is dependent upon the temperature and nature of the arc, and this must be borne in mind in any attempt at comparative results where different lamps have been used.
Factors in Supply and Use of Cooling Water
Authors: Shoaff Paul S.
Published: February 2011

WE OF the rubber industry are naturally interested in water mainly as a cooling agent. We are concerned with its source, the quantities regularly available and the temperature at which it is supplied. A reference to the requirements of the Goodyear factories in Akron indicates how important a factor it is. The two plants must be supplied with over 20,000,000 gallons of water per day exclusive of the amount taken from the city mains for special purposes. Approximately 13,250,000 gallons of this volume are used for cooling mills, internal mixers, calendars and tubing machines. The greater proportion of this is recovered and with the addition of fresh water is employed for cooling heaters, in the reclaiming plant and for various services throughout the factories. When the day's cycle has been completed, more than 13,000,000 gallons of warm water are returned to their principal source, the Little Cuyahoga River. In the cooler seasons all of the 13,250,000 gallons of cooling water come from the impounded waters of the river, which is fed largely by Wingfoot Lake and partly by Springfield Lake. During the summer the daily supply is a mixture of deep well water and the necessary balance from the river.
Effect of Various Types of Carbon Black on Certain Physical Properties of Rubber Compounds
Authors: Beaver D. J. , Keller T. P.
Published: February 2011

The data presented herein show that in general the presence of oxygen on carbon black retards the rate of vulcanization in direct proportion to the amount of oxygen present and also decreases the maximum physical properties obtainable with a given amount of accelerator. The aging data show that the presence of this oxygen on the black increases the rate of aging as the amount of oxygen increases, but not in direct proportion to the per cent of this oxygen present. It can be concluded, therefore, that compounds which contain a small amount of oxygen, such as thermatomic, G black, or acetylene black, will give better aging stocks than compounds containing higher amounts of oxygen such as lampblack and standard channel blacks. No correlation could be found between the acetone extract, iodine adsorption, or oil adsorption, and the effect of these blacks on the rate of cure or aging.
The Isomerization of Rubber to Cyclorubber under the Influence of High Tension Alternating Currents
Authors: Fromandi Guido
Published: February 2011

Chemical transformations by means of high tension alternating currents, accompanied by the activation of oxygen were investigated extensively toward the end of the last century by de Hemptinne, who studied the behavior of a large number of chemical substances and systems under the influence of these discharges. These transformations are in general characterized by the fact that the discharge causes deep seated changes in the molecular structure of the substances, principally organic, on which it acts. The chemistry of some, indeed most, of the reactions produced by the silent electric discharge in liquid and solid systems has never been definitely explained, particularly when these reactions are accompanied by a complete destruction of the molecule. In the so-called “Voltol” oil process, the oil becomes more viscous when treated by the silent discharge and becomes a valuable lubricant, well known in the automotive market today. This product led to a thoróugh knowledge of the process and to a confirmation of Nernst's theory, according to which the increase in viscosity is due to a displacement of the intramolecular bonds caused by the impact of ions and electrons, resulting in the formation of polymerization products of high molecular weight. The discharge is produced in a rarified atmosphere of hydrogen, and due to the alternating field the ions and electrons in the gaseous layer undergo such acceleration that they increase markedly in numbers by impact. Because of their great kinetic energy the effect on the liquid molecules is exceptionally violent. The molecules split off hydrogen, which, because of its atomic, highly active form immediately becomes attached to the unsaturated bonds, forming saturated compounds. This is true of saturated as well as unsaturated compounds used as the substances to be treated, the mechanism of the reaction being characterized by the following general equation:
Some Observations with Ultra-Accelerators
Authors: Cummings A. D. , Simmons H. E.
Published: February 2011

ALTHOUGH much has been done on accelerators, in such a vast field there is always room for additional work, particularly if, as Whitby predicts, ultra-accelerators will be the main class used in course of time. This investigation was started with the following points in view: (1) to prepare several thiuramdisulfides and related compounds; (2) to note their relative behavior when used as accelerators; and, if possible, deduce some explanation for the mode of action of the class or for the behavior of some particular compound, or gain additional evidence for any existing theories. The relative inactivity of thiurams derived from primary amines has been mentioned but no explanation published. Evidence is presented to show that decomposition of the compound into hydrogen sulfide and a mustard oil takes place so quickly at the temperatures used that there is not time for the generation of much active accelerator. It was found that tetramethylthiurammonosulfide plus sulfur equivalent to the difference in sulfur content between it and the disulfide gave a cure in a rubber-zinc oxide mix practically equivalent to that given by the disulfide alone. This indicates that zinc dimethyldithiocarbamate may be the active accelerating agent.
Organic Rubber Colors
Authors: Naunton W. J. S.
Published: February 2011

DYESTUFFS are divided into about twelve main groups according to their method of manufacture; thus we have the sulfur colors, which are made by fusing together various organic compounds with sulfur and sodium sulfide, the azo colors in which the intermediates are coupled together by means of the diazo reaction, and so on. Most of the organic dyestuffs may be regarded as salts in which either the colored organic base is combined with a colorless inorganic acid (basic dyes) or the colored organic acid is combined with a colorless inorganic base (acid dyes). This salt formation has in most cases rendered the color soluble in water. In the absence of salt-forming groups in the colored compounds, or when their action is insufficiently potent, the resulting substances are sufficiently insoluble in water to be of direct use in the rubber industry; examples of such pigments are monolite yellow and monolite red. A consideration will be made of the method of employing the water soluble dye-stuffs, which are far more numerous than the insoluble ones, in the coloring of rubber. The obvious way is to convert them where possible into lakes or insoluble colored compounds. The two most important processes of lake making are (1) precipitating an insoluble salt of the soluble dyestuff upon a suitable white pigment, known as the “lake-base” and (2) employing a mineral earth which absorbs certain dyes from aqueous solution.
Rubber as it is Revealed by X-Rays
Authors: Clark George L.
Published: February 2011

THE beginning of the year of 1929 seems to be a logical time for considering critically the status of knowledge concerning the fundamental structure of rubber. Of all the contributions by various methods to the problem, those which have come as a result of the application of X-ray diffraction methods may be considered the most unique and perhaps most important in the past few years. It was known previous to 1925 that when rubber is strongly stretched it becomes warm, its specific gravity increases and it becomes doubly refracting. The name of J. R. Katz has become renowned throughout the world as a result of the experiment which he performed of causing a fine beam of X-rays to pass through a specimen of stretched rubber behind which was placed a photographic film. This experiment was one of those fortunate accidents which appear frequently in the history of science, but on the other hand, it was the result of clear thinking, rational deduction, and a keen appreciation of the possibilities of application of X-rays to the examination of the ultimate structure of materials.
Measuring Temperatures of Calender Rolls
Authors: Keltner L. R.
Published: February 2011

IT has only been within recent years that the importance of knowing the exact conditions under which rubber is processed has been appreciated. This is especially true of the calendering operation. For many years a calender man's experience was the only assurance one had of producing properly processed material. Demand for greater uniformity of product now necessitates more uniformly processed materials. The ultimate outcome of these demands was the setting up of a definite set of mixing and calendering specifications. It is readily recognized that a calendering specification would not be complete without some reference to the calender roll temperature. The effect of heat on rubber processing cannot be discussed here but it should be stated that it is of tremendous importance. The need for a roll temperature measuring device thus presented itself and various types of instruments have been experimented with. Early experiments were made in a crude manner by attaching the hot junction of a thermo-couple to a small 1-inch square brass plate which was mounted on a yard stick. This stick was used as a lever and a cross bar from the calender housing as a fulcrum. After the brass plate had been placed at the desired spot on the roll, pressure was applied by pulling up on the end of the stick opposite the junction. Data obtained were satisfactory but the apparatus. had no practical application in production. Other experiments along the same line were carried out later.
X-Ray Contributions to the Problem of Polymerization
Authors: Clark George L.
Published: February 2011

It may be readily admitted that x-ray studies of the problem of polymerization are only in their beginning. Some complexities—as, for example, small unit cell dimensions— have been added, but in general a real contribution has already been made as a basis for further advances, which will come as knowledge of interpretation increases and as experimental technic improves.
Report of the Raw Rubber Specifications Committee
Authors: Spear Ellwood B. , Boggs C. R. , Simmons H. E. , Trumbull H. L. , Shepard N. A.
Published: February 2011

AS INTIMATED in a previous report of the Committee presented at the St. Louis meeting in April, 1928, a temporary procedure was adopted in order to ascertain whether or not the five laboratories represented on the Committee could obtain reasonably comparable stress-strain relationships using the same batch of rubber. A complete report is appended in which the procedure is outlined and the results of each laboratory are given in considerable detail. After careful deliberations the Committee has concluded that the testing of raw rubber is not in a very satisfactory state. It therefore makes the following recommendations: (1) The testing of raw rubber should be made the subject of thorough investigations. (2) The work should be undertaken by a Physical Testing Committee, preferably under the jurisdiction of the Rubber Division of the American Chemical Society.
Some Practical Aspects of Rubber Evaluation
Authors: Dinsmore R. P.
Published: February 2011

In various papers, published in the past three years, E. C. Zimmerman and the writer have made references to the variability of crude rubber as determined by the properties of vulcanized compounds of various types. We were, I believe, the first to point out the chief stumbling block in the way of establishing a standard test formula for evaluating crude rubber, namely the variation in both quality and rate of cure produced by curing the same rubber with different curing agents. At the outset we were confronted with difficulties which resulted from a deplorable lack of standardization of rubber testing methods, and more specifically from a lack of agreement as to the proper way to select comparable cures. Indeed, it is obvious that these drawbacks have been among the major causes for lack of correlation of available data on the subject. We have stressed the importance of considering those properties of the vulcanizate which are reflected in the performance of the finished product, and have stated our objections to many of the popular criteria, such as “slope,” tensile product, tensile, and coefficient of vulcanization. We had concluded that aging should be the chief criterion of best technical cure. Accelerated age tests cannot be relied upon for comparison of different mixes, but experience has shown that for lightly loaded mixes hand tear is a reliable method of fixing the best aging cure. With this as a means of selecting the time of cure, the quality was studied by comparing the stiffness of the stress-strain curve at best cure. Later, in a paper on acceleration classification, if was shown that these conclusions might properly be modified when dealing with loaded mixes. Here the cures, as selected by hand tear and by maximum, tensile product, were in substantial agreement, except in the case of non-accelerated stocks.
The Nature of Vulcanization Part IV
Authors: Stevens H. P. , Stevens W. H.
Published: February 2011

(1) At low temperatures by means of accelerators it is possible to produce vulcanites containing “combined sulfur” considerably in excess of that required for the formula C5H8S. Such vulcanites may be obtained by vulcanizing at 100° with a variety of ultra-accelerators with and without zinc oxide as an activator. If zinc oxide or a zinc salt is used the excess coefficient cannot be explained by the presence of the zinc sulfide in the vulcanite. (2) The amount of sulfur combined with the rubber, given sufficient heating and presence of accelerator, is mainly dependent on the excess of sulfur present. (3) Extraction of the vulcanite with hydrochloric acid-ether mixture removes a part of the “combined” sulfur. A considerable amount is removed when the amount of combined sulfur is very large, but even then the amount of sulfur remaining is considerably in excess of that required by the formula C5H8S. (4) Vulcanization at low temperatures in solution in accordance with Whitby's procedure with the aid of accelerators also yields vulcanites with coefficients in excess of that required for the formula C5H8S. (5) The result of vulcanization at low temperatures is approximately the same, whether the rubber contains all the protein and serum ingredients, the usual proportion, or very little. (6) Extraction of sulfur from vulcanite with hot acetone vapor is not complete after 1210 hrs. (7) Having regard to the hydrogen sulfide and other volatile sulfur compounds evolved in appreciable quantities during vulcanization, it is evident that part of the combined sulfur results from substitution of hydrogen by sulfur. This substituted product is decomposed by the hydrochloric acid-ether mixture. It may not be possible to decompose the whole in this manner. Consequently, any “combined” sulfur in excess of that required by the formula C5H8S may result from substitution in the molecule.
Effect of Antioxidants in Typical Rubber Stocks
Authors: Reed Marion C.
Published: February 2011

The results of these tests show that antioxidants are of value in stocks which become hot in service, such as bus tubes, belt frictions, and heavy truck tire treads. It is believed that aging at 90° C., both in air and in an inert gas free from oxygen, will be of assistance in separating the factors of oxidation and overcure in designing rubber compounds for resistance to heat.
A New Flexing Machine for Rubber
Authors: Torrance Philip M. , Peterson Lester C.
Published: February 2011

TREAD cracking is one of the most annoying problems occupying the attention of rubber chemists at the present time. While there is no doubt that tread design and the construction of the tire as a whole have great influence in producing this phenomenon, the nature of the tread compound itself is a very important factor. A real need has been felt in the industry for a laboratory flexing machine which would rapidly and inexpensively give results comparable to those obtained in road tests in order to study the effect that variations in compounding have upon this type of failure. The authors have developed a simple machine which it was felt might be of interest in this connection. Illustrations 1 and 2 are front and side-view photographs of this machine. It consists of a rotor disk one inch thick keyed to the shaft of a 1/4 h.p. induction motor and radially slotted about its periphery to take twelve samples. Around this is a steel ring placed off center in relation to the rotor. The test samples are mold-cured slabs of rubber 1 inch wide, 1 1/8 inches long, and 3/16-inch thick, having two semi-circular grooves molded across their width. When placed in a slot of the rotor, a test piece is held in place by a tightly-fitting cylindrical steel pin which fits in one of the semi-circular grooves in the test piece and in a similar groove cut in the wall of the slot.