bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of laser cavity gaseous impurities on the performance of an industrial CO2 laser
Authors: Hsu C. R. , Albright C. E. , Khakhalev A.
Published: August 2012

Contamination in the cavities of high power industrial CO2 lasers is a cause of laser performance degradation. Such degradation can result in laser downtime and significant loss of productivity. The laser cavity gas supply can contribute to this contamination, but there is confusion about the level of gas impurity concentration which can cause a degradation process. The overall objective of this investigation was to study the effects of cavity gas contaminants on the performance of an industrial fast-axial-flow CO2 laser. A 3 kW fast-axial-flow CO2 laser operated for 2100 h prior to this investigation was employed in a series of gas contamination experiments. The operating power was selected as 1500 W. After cleaning the laser cavity, the absorptivities of output coupler and rear mirror were measured after laser operation using both ultra-high-purity laser cavity gases (99.999%) and premixed contaminated helium (100 ppm, 1000 ppm and 5000 ppm for C3H8, C2H4, CH4 and O2). The output powers were also measured. The results show that increased absorptivities in the output coupler were observed with both hydrocarbon and oxygen impurities compared to those with ultra-high-purity gases (99.999%). The increased absorptivities in the output coupler and rear mirror seem to correlate with the total carbon content in the laser cavity due to the gaseous hydrocarbon impurities. Deposition on the surfaces of corner mirrors were identified as carbon using energy dispersive electron spectroscopy analysis. Several flakes of deposited carbons were also identified on the surface of the NaCl window inside the resonator after operating the laser using 5000 ppm propane in helium. 1000 ppm oxygen in the laser gas mixture resulted in an increase of 1.4 % in the output power (4.8 % for 5000 ppm oxygen). 1000 ppm of propane resulted in a decrease of 17 % in the output power. A 44.8 % of power drop was observed when using 5000 ppm propane. The negative effect of contamination (especially hydrocarbon) on high power laser performance was demonstrated.
An iRGD Based Strategy to Study Electrochemically the Species Inside a Cell
Authors: Ning Limin , Li Xiaoxi , Ding Xiaorong , Yin Yongmei , Li Genxi
Published: August 2012

This paper reports a method for electrical communication between the inner part of cells and an electrode with the help of iRGD peptide. Due to the enhancement of the cell penetration caused by iRGD peptide, DNA molecules, previously modified on a gold electrode surface, can be easily transfected into the cells. At the same time, doxorubicin, an anticancer drug, can also be transfected into cells with high penetration. Consequently, doxorubicin binds to DNA chains through electrostatic interaction, and the redox reaction is transferred out of the cell across the cell membrane. As a result, this work may provide a novel way to get information from inside of cells.
Transfer of Labour Time on the World Market: Religious Sanctions and Economic Results
Authors: Sandemose Jørgen
Published: August 2012

This paper investigates the extent to which a term like “globalization”, especially in its sense of implying the existence of a system, or of dominant features favouring development towards some system, is adaptable to a theory of a world economy which is to take due notice of the structure of the exchange value of commodities on the world market. A leading idea is that religious outlooks, in the way they were conceptualized by Karl Marx, have a strong bearing upon the difference in labour intensities in countries contributing to the world market, and thereby upon the differences in international values and prices. These differences are expressed in a scale-based, rigid structure on the world market itself—a structure which gives us the fundamental reason why certain specific countries or areas may get steadily poorer in relative terms, while others may constantly get relatively richer through the same mechanism. Consequently, when (as it is done here) religion is taken to express the quintessence of the cultural level of societies, it can be said that the comparative study of religions gives us a key to the understanding of crucial economic differences between nations. The differences in question are primarily those prevailing between capitalist societies on the one hand, and non-capitalist, or what is here called patrimonial societies, on the other.
Investissement narcissique, figure du double et fantasme d'enfant meurtrier
Authors: Guittonneau Mireille
Published: August 2012

Dans certaines configurations familiales, la figure de double portée par l’enfant semble accomplir l’équivalent d’un meurtre psychique. Livrée à l’écoute de l’analyste, cette figure dévoile l’investissement narcissique qui la sous-tend. Elle fait également apparaître l’enjeu vital qui se joue pour ces parents. En effet, si cette figure du double leur permet d’évincer toute confrontation à une individuation ressentie comme menace, le meurtre psychique qu’elle semble réaliser a, lui, pour but de les préserver du fantasme d’un enfant meurtrier. En fait, ce fantasme déplace dans le futur le meurtre psychique qu’ils ont eux-mêmes subi dans leur enfance. Afin de se soustraire à la menace toujours à venir d’un tel meurtre, il faudrait donc le perpétrer au présent, sur la personne de l’enfant : la figure du double en serait le moyen.
Vitesse, déplacement et transparence des êtres fantomatiques et des personnes autistes
Authors: Lheureux-Davidse Chantal
Published: August 2012

Les représentations que nous nous faisons des fantômes nous éclairent sur les états flottants des personnes peu habitées dans leur corps et peu investies dans les relations en direct. Chez des personnes absorbées par un deuil ou dans des cas de dépression, ou chez des personnes en retrait autistique, la perception de mouvements trop rapides ou imprévisibles et des déplacements dans l’espace provoquent parfois des angoisses spatiales conséquentes qui ne les rendent plus disponibles à la relation. Afin qu’une identification et qu’une rencontre soient possibles, l’accordage du thérapeute à leur rythme souvent très lent et délicat ainsi que les commentaires sur les vécus internes peuvent réguler des vécus trop intenses ou clivés aux niveaux tant sensoriel et émotionnel que relationnel. Chez des personnes comme transparentes qui ne peuvent encore se manifester, les réactions se font d’abord en différé avant qu’elles soient en synchronie.
L'apport freudien sur les névroses de guerre : un nouage entre théorie, clinique et éthique
Authors: Sokolowsky Laura , Maleval Jean-Claude
Published: August 2012

La prise en compte des traumatismes de la Première Guerre mondiale constitua un moment charnière dans l’histoire de la psychanalyse. L’étude des névroses traumatiques en temps de guerre eut des répercussions au niveau de la théorie psychanalytique et des conséquences au niveau de la politique freudienne au début des années 1920. Cette catégorie clinique permit à Freud d’aborder autrement le phénomène de la répétition, comme répétition du déplaisir, et de jeter les bases d’un nouveau dualisme pulsionnel. Elle le mena aussi à formuler des avancées de la théorie psychanalytique de l’angoisse, du narcissisme et de l’identification. Freud fut appelé comme expert devant une commission du parlement autrichien, chargée d’examiner les plaintes d’anciens soldats qui avaient été traités par le biais de traitements corporels à visée punitive. Il dut se prononcer sur le cas exemplaire du lieutenant Kauders. Ce soldat, atteint de symptômes post-traumatiques, fut suspecté de simulation et hospitalisé dans la clinique du professeur Wagner-Jauregg afin d’y être traité par le procédé électrique, alors couramment employé. Dans le cadre de son expertise, Freud prit la défense du lieutenant en affirmant la dimension psychique du trauma. Il souligna que l’application thérapeutique de la psychanalyse sur une large échelle était justifiée, les expériences menées par ses élèves auprès des soldats traumatisés l’ayant déjà prouvé. Le développement d’institutions psychanalytiques, sur le modèle de la policlinique de Berlin, fondée en février 1920, constitua la toile de fond de cette argumentation et la visée politique d’une psychanalyse pour tous.
Crise sanitaire et tendances de la mortalité par cause en Biélorussie (1965-2008)
Authors: Grigoriev Pavel
Published: August 2012

L’évolution de la mortalité biélorusse a fait couler beaucoup moins d’encre que celles d’autres pays de l’ex-URSS. Jusqu’à récemment, l’indisponibilité de données détaillées sur les causes de décès était un obstacle majeur à la recherche sur la mortalité dans ce pays. Cet article vise deux objectifs principaux. Le premier est la reconstruction de séries continues de décès par cause de 1965 à nos jours. Le second est l’analyse des séries ainsi obtenues pour prendre la mesure des principaux changements intervenus durant cette période. L’analyse porte sur les données originales de décès par cause. Le problème de discontinuité des séries annuelles provoquées par les révisions successives de la classification des maladies et causes de décès a été résolu grâce à une méthode de reclassement a posteriori des données anciennes. Cela permet de disposer désormais de séries de décès par cause à définition constante et de les mettre à disposition de la communauté scientifique internationale. Cette étude montre à quel point les tendances de la mortalité biélorusse sont défavorables depuis près d’un demi-siècle, principalement pour les hommes. Les maladies cardiovasculaires et les morts violentes liées à l’abus d’alcool sont les caractéristiques majeures de la dégradation de la santé publique, dont la dynamique à long terme est à la base d’une crise sanitaire chronique.
CD28–B7 Interaction Modulates Short- and Long-Lived Plasma Cell Function
Authors: Njau Modesta N. , Kim Jin Hyang , Chappell Craig P. , Ravindran Rajesh , Thomas Leela , Pulendran Bali , Jacob Joshy
Published: August 2012

The interaction of CD28, which is constitutively expressed on T cells, with B7.1/B7.2 expressed on APCs is critical for T cell activation. CD28 is also expressed on murine and human plasma cells but its function on these cells remains unclear. There are two types of plasma cells: short-lived ones that appear in the secondary lymphoid tissue shortly after Ag exposure, and long-lived plasma cells that mainly reside in the bone marrow. We demonstrate that CD28-deficient murine short- and long-lived plasma cells produce significantly higher levels of Abs than do their wild-type counterparts. This was owing to both increased frequencies of plasma cells as well as increased Ab production per plasma cell. Plasma cells also express the ligand for CD28, B7.1, and B7.2. Surprisingly, deficiency of B7.1 and B7.2 in B cells also led to higher Ab levels, analogous to Cd28−/− plasma cells. Collectively, our results suggest that the CD28–B7 interaction operates as a key modulator of plasma cell function.
Modeling SOA formation from the oxidation of intermediate volatility n-alkanes
Authors: Aumont B. , Valorso R. , Mouchel-Vallon C. , Camredon M. , Lee-Taylor J. , Madronich S.
Published: August 2012

Abstract. The chemical mechanism leading to SOA formation and ageing is expected to be a multigenerational process, i.e. a successive formation of organic compounds with higher oxidation degree and lower vapor pressure. This process is here investigated with the explicit oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere). Gas phase oxidation schemes are generated for the C8–C24 series of n-alkanes. Simulations are conducted to explore the time evolution of organic compounds and the behavior of secondary organic aerosol (SOA) formation for various preexisting organic aerosol concentration (COA). As expected, simulation results show that (i) SOA yield increases with the carbon chain length of the parent hydrocarbon, (ii) SOA yield decreases with decreasing COA, (iii) SOA production rates increase with increasing COA and (iv) the number of oxidation steps (i.e. generations) needed to describe SOA formation and evolution grows when COA decreases. The simulated oxidative trajectories are examined in a two dimensional space defined by the mean carbon oxidation state and the volatility. Most SOA contributors are not oxidized enough to be categorized as highly oxygenated organic aerosols (OOA) but reduced enough to be categorized as hydrocarbon like organic aerosols (HOA), suggesting that OOA may underestimate SOA. Results show that the model is unable to produce highly oxygenated aerosols (OOA) with large yields. The limitations of the model are discussed.
Impact of the modal aerosol scheme GLOMAP-mode on aerosol forcing in the Hadley Centre Global Environmental Model
Authors: Bellouin N. , Mann G. W. , Woodhouse M. T. , Johnson C. , Carslaw K. S. , Dalvi M.
Published: August 2012

Abstract. The Hadley Centre Global Environmental Model (HadGEM) includes two aerosol schemes: the Coupled Large-scale Aerosol Simulator for Studies in Climate (CLASSIC), and the new Global Model of Aerosol Processes (GLOMAP-mode). GLOMAP-mode is a modal aerosol microphysics scheme that simulates not only aerosol mass but also aerosol number, represents internally-mixed particles, and includes aerosol microphysical processes such as nucleation. In this study, both schemes provide hindcast simulations of natural and anthropogenic aerosol species for the period 2000–2006. HadGEM simulations using GLOMAP-mode compare better than CLASSIC against a data-assimilated aerosol re-analysis and aerosol ground-based observations. GLOMAP-mode sulphate aerosol residence time is two days longer than CLASSIC sulphate aerosols, whereas black carbon residence time is much shorter. As a result, CLASSIC underestimates aerosol optical depths in continental regions of the Northern Hemisphere and likely overestimates absorption in remote regions. Aerosol direct and first indirect radiative forcings are computed from simulations of aerosols with emissions for the year 1850 and 2000. In 1850, GLOMAP-mode predicts lower aerosol optical depths and higher cloud droplet number concentrations than CLASSIC. Consequently, simulated clouds are much less susceptible to natural and anthropogenic aerosol changes when the microphysical scheme is used. In particular, the response of cloud condensation nuclei to an increase in dimethyl sulphide emissions becomes a factor of four smaller. The combined effect of different 1850 baselines, residence times, and cloud susceptibilities, leads to substantial differences in the aerosol forcings simulated by the two schemes. GLOMAP-mode finds a present-day direct aerosol forcing of −0.49 W m−2 on a global average, 72% stronger than the corresponding forcing from CLASSIC. This difference is compensated by changes in first indirect aerosol forcing: the forcing of −1.17 W m−2 obtained with GLOMAP-mode is 20% weaker than with CLASSIC. Results suggest that mass-based schemes such as CLASSIC lack the necessary sophistication to provide realistic input to aerosol-cloud interaction schemes. Furthermore, the importance of the 1850 baseline highlights how model skill in predicting present-day aerosol does not guarantee reliable forcing estimates. Those findings suggest that the more complex representation of aerosol processes in microphysical schemes improves the fidelity of simulated aerosol forcings.
Complexity versus simplicity: an example of groundwater model ranking with the Akaike Information Criterion
Authors: Engelhardt I. , De Aguinaga J. G. , Mikat H. , Schüth C. , Lenz O. , Liedl R.
Published: August 2012

Abstract. A groundwater model characterized by a lack of field data to estimate hydraulic model parameters and boundary conditions combined with many piezometric head observations was investigated concerning model uncertainty. Different conceptual models with a stepwise increase from 0 to 30 adjustable parameters were calibrated using PEST. Residuals, sensitivities, the Akaike Information Criterion (AIC), and the likelihood of each model were computed. As expected, residuals and standard errors decreased with an increasing amount of adjustable model parameters. However, the model with only 15 adjusted parameters was evaluated by AIC as the best option with a likelihood of 98%, while the uncalibrated model obtained the worst AIC value. Computing of the AIC yielded the most important information to assess the model likelihood. Comparing only residuals of different conceptual models was less valuable and would result in an overparameterization of the conceptual model approach. Sensitivities of piezometric heads were highest for the model with five adjustable parameters reflecting also changes of extracted groundwater volumes. With increasing amount of adjustable parameters piezometric heads became less sensitive for the model calibration and changes of pumping rates were no longer displayed by the sensitivity coefficients. Therefore, when too many model parameters were adjusted, these parameters lost their impact on the model results. Additionally, using only sedimentological data to derive hydraulic parameters resulted in a large bias between measured and simulated groundwater level.
Hydro-meteorological evaluation of a convection-permitting ensemble prediction system for Mediterranean heavy precipitating events
Authors: Vié B. , Molinié G. , Nuissier O. , Vincendon B. , Ducrocq V. , Bouttier F. , Richard E.
Published: August 2012

Abstract. An assessment of the performance of different convection-permitting ensemble prediction systems (EPSs) is performed, with a focus on Heavy Precipitating Events (HPEs). The convective-scale EPS configuration includes perturbations of lateral boundary conditions (LBCs) by using a global ensemble to provide LBCs, initial conditions (ICs) through an ensemble data assimilation technique and perturbations of microphysical parameterisations to account for part of model errors. A probabilistic evaluation is conducted over an 18-day period. A clear improvement is found when uncertainties on LBCs and ICs are considered together, but the chosen microphysical perturbations have no significant impact on probabilistic scores. Innovative evaluation processes for three HPE case studies are implemented. First, maxima diagrams provide a multi-scale analysis of intense rainfall. Second, an hydrological evaluation is performed through the computation of discharge forecasts using hourly ensemble precipitation forecasts as an input. All ensembles behave similarly, but differences are found highlighting the impact of microphysical perturbations on HPEs forecasts, especially for cases involving complex small-scale processes.
Review Article: "The Lagrangian description of aperiodic flows: a case study of the Kuroshio Current"
Authors: Mendoza C. , Mancho A. M.
Published: August 2012

Abstract. This article reviews several recently developed Lagrangian tools and shows how their combined use succeeds in obtaining a detailed description of purely advective transport events in general aperiodic flows. In particular, because of the climate impact of ocean transport processes, we illustrate a 2-D application on altimeter data sets over the area of the Kuroshio Current, although the proposed techniques are general and applicable to arbitrary time dependent aperiodic flows. The first challenge for describing transport in aperiodical time dependent flows is obtaining a representation of the phase portrait where the most relevant dynamical features may be identified. areas that are related to confinement regions. This representation is accomplished by using global Lagrangian descriptors that when applied for instance to the altimeter data sets retrieve over the ocean surface a phase portrait where the geometry of interconnected dynamical systems is visible. The phase portrait picture is essential because it evinces which transport routes are acting on the whole flow. Once these routes are roughly recognised, it is possible to complete a detailed description by the direct computation of the finite time stable and unstable manifolds of special hyperbolic trajectories that act as organising centres of the flow.
Poemas de Federico Mayor Zaragoza
Authors: Zaragoza Federico Mayor
Published: August 2012

DOI: http://dx.doi.org/10.5377/cultura.v17i54.769 Cultura de Paz Año 17 No 54 49-51
Short-Term Therapy with Rosiglitazone, a PPAR-γAgonist, Improves Metabolic Profile and Vascular Function in Nonobese Lean Wistar Rats
Authors: Naderali Mohammad M. , Itua Imose , Abubakari Abdul-Razak , Naderali Ebrahim K.
Published: August 2012

A number of preclinical and clinical studies have reported blood-pressure-lowering benefits of thiazolidinediones in diabetic subjects and animal models of diabetes. This study was designed to further elucidate vascular effects of rosiglitazone, on healthy nonobese, lean animals. Adult male Wistar rats were randomized and assigned to control and rosiglitazone-treated groups and were dosed daily with either vehicle or rosiglitazone (10 mg kg−1day−1) by oral gavage for 5 days. Compared with control group, rosiglitazone treatment significantly reduced plasma levels of triglycerides (>240%) and nonesterified free fatty acids (>268%) (both,P<0.001). There were no changes in vascular contractility to KCl or noradrenaline between two groups. However, rosiglitazone therapy improved carbamylcholine-induced vasorelaxation (93±3% versus control78±2,P<0.01) an effect which was abolished by L-NAME. There was no difference in sodium nitroprusside-induced vasorelaxation between the control and rosiglitazone-treated animals. These results indicate that short-term rosiglitazone therapy improves both metabolic profile and vascular function in lean rats. The vascular effect of rosiglitazone appears to be mediated by alteration in NO production possibly by activation of endothelial PPARγ. This increased NO production together with improved lipid profile may explain mechanism(s) of blood-pressure-lowering effects of thiazolidinediones on both human and experimental animals.
Trends in Industrial Toxicology
Authors: Bingham Eula , Cohrssen Barbara
Published: August 2012

The information in industrial toxicology that is produced by industry, government, or academia has changed greatly in emphasis and direction in the past 10 years. Carcinogenesis still remains of greatest importance in industrial toxicology and is based on human studies, environmental studies and epidemiology data. However, in the past, research was generated from the data and information obtained from industrial health departments. Now, most of the research is being done in university laboratories and these laboratories are looking at the mechanisms of action of specific chemicals. The revolution in genetics and specifically in mapping the human genome has greatly affected toxicologic research.

These trends and developments are presented, as well how the government agencies have become the sources of much of the new toxicologic information that is available. The toxicologic information provided by these volumes will be useful providing the global workplace with the necessary data for keeping workers healthy.
Regulations and Guidelines for Toxic Exposures in the Workplace
Authors: Monforton Celeste
Published: August 2012

Occupational diseases can serve as the sentinel warnings about the hazards of toxic substances. Regulations and guidelines to control workers' exposure to toxic substances have been influenced by larger social forces, which may have enhanced or impeded the degree of protection provided. Toxicological and epidemiological research and technological developments provide the rationale and the methodologies used to develop legislation, regulations, and guidelines to reduce occupational exposure to toxins. Most regulations and standards for worker protection have training requirements to increase employees' understanding of workplace hazards. These complement the engineering and administrative controls implemented by the affected employers. In the U.S., many industries fall under the authority of the Occupational Safety and Health Administration, but some are also required to comply with worker‐safety regulations issued by other agencies, such as the Environmental Protection Agency, Nuclear Regulatory Commission or Department of Transportation. A brief description of workplace standards and occupational exposure limits for selected countries are presented.
Alicyclic Hydrocarbons
Authors: Baxter C. Stuart
Published: August 2012

The alicyclic hydrocarbons include the cycloalkanes, also calledcycloparaffins,cyclanes, andnaphthenes, and the cycloalkenes, also known ascycloolefinsandcyclenes, and their alkyl and alkenyl derivatives. Some of these derivatives occur naturally in plants and are commonly known asterpenes. Other compounds can be isolated from crude petroleum refinery distillates or catalytically cracked petroleum products. Cycloalkanes are extensively used to produce reformed aromatics and as solvents or synthesis intermediates. Some physical properties of the cycloalkanes are given.

Cyclopropane and cyclobutane are gases and have been used as anesthetics. Cyclopentane and higher members are liquids with low acute and chronic toxicity overall, but still able to induce many toxic responses characteristic of lipophilic compounds, including central nervous system (CNS) depression, dizziness, and headache. For cyclohexane and higher analogs, the margin of safety between CNS depression and death is very narrow and symptomatically barely recognizable. Following ingestion or inhalation, cycloalkanes are exhaled in unchanged form or rapidly metabolized into water‐soluble metabolites, usually glucuronides. Exposure of humans and laboratory animals to high concentrations may cause excitement, loss of equilibrium, stupor, and coma, but rarely death. Oral administration of high doses to animals has additionally resulted in severe diarrhea, vascular collapse, and heart, lung, liver, and brain degeneration. Cycloparaffins and cycloalkenes are also ocular and dermal irritants since, as lipophilic agents, they defat the skin. In many cases, they are also skin sensitizers; their sensitizing activity increases with the number of double bonds. The liquid members up to cyclooctane, and to a lesser extent cyclododecane, are aspiration hazards.

The cyclic olefins are more highly reactive than their paraffin counterparts. They contribute to photochemical smog by reacting with ozone and other small molecular or ionic species. Selected physical properties are given. In C4–C7cycloalkenes, toxicity increases with molecular weight. Cycladienes and polyenes appear to possess increasingly irritant, toxic, and sensitizing properties, peaking somewhat higher for cycladienes than for monocyclic alkenes. The aspiration hazard also appears higher for the cycloalkenes than the cycloalkanes.
Cyanides and Nitriles
Authors: Kopras Elizabeth J.
Published: August 2012

Cyanides are among the most acutely toxic of all industrial chemicals and are produced in large quantities and used in many different applications. However, they cause few serious accidents or deaths. This is partly because the wordcyanideis synonymous with a highly poisonous substance and a certain amount of care in handling is thereby ensured. The cyanides and nitriles are a disparate group of substances characterized by the presence of a cyanide (CN) group in their molecular structure. The cyanide group consists of a carbon bonded to a nitrogen. In those cases where the cyanide group is readily available, toxicity is likely to have similarity to hydrogen cyanide (HCN). The chemical and physical characteristics of the compound will affect the potential availability of the cyanide group and therefore, the hazards associated with different chemical species.

For purposes of the toxicologist, cyanides and nitriles can be classified into groups based on their common properties. Group 1, inorganic cyanides, includes hydrogen cyanide, cyanogen, and simple salts such as sodium, potassium, calcium, and ammonium cyanide of hydrogen cyanide that dissociate readily to release CN−1ions. Group 2 includes halogenated compounds such as cyanogen chloride or bromide. Group 3 comprises simple and complex salts such as cobalt cyanide trihydrate, cupric and cuprous cyanide, silver cyanide, and ferricyanide and ferrocyanide salts of hydrogen cyanide that do not dissociate readily to release CN−1ions. Group 4, organic cyanides, includes cyanide glycosides produced by plants such as amygdalin and linamarin. Group 5, nitriles, have a general structure R‐CNO, and include compounds such as acetonitrile (methyl cyanide), acrylonitrile, and isobutyronitrile.
Saturated Halogenated Aliphatic Hydrocarbons Two to Four Carbons
Authors: Reid Jon B. , Muianga Custodio V.
Published: August 2012

This chapter relies extensively on information provided in earlier editions. Several online databases were utilized in searching for recent information in preparing the chapter. These included NTP (National Toxicology Program), IRIS (Integrated Risk Information Service), and the ATSDR (Agency for Toxic Substances and Disease Registry) websites. Most recent information was sought through MEDLINE and when possible the original articles were reviewed. Debatably, IRIS was considered to be the last word with regard to cancer. Many of the compounds have been recently reviewed by the ATSDR and are reported in their toxicological profiles. Recent reviews were utilized in preparing this chapter. In addition, theNIOSH Pocket Guide to Chemical Hazardsand the ACGIH'sTLV's® for Chemical Substances and Physical Agents: 2011(CD) were utilized.
Unsaturated Halogenated Hydrocarbons
Authors: Belpoggi Fiorella , Chiozzotto D. , Lauriola M.
Published: August 2012

This chapter contains details on 12 unsaturated halogenated hydrocarbons. The considered chemicals are 1,3‐dichloropropene,cis‐ andtrans‐1,2‐dichloroethylene, dichloroacetylene, allyl chloride, hexachlorobutadiene, β‐chloropropene, vinylidene chloride, vinyl chloride, vinyl bromide, vinyl fluoride, trichloroethylene, and tetrachloroethylene. These compounds are used as fumigants, pesticides, solvents, and chemical intermediates. This chapter follows the outline determined for compounds and includes physical and chemical properties, production and use, exposure assessment, toxic effects (experimental animal and epidemiology studies), standards, regulations, and guidelines, and studies on environmental impact.
Aliphatic Carboxylic Acids: Saturated
Authors: Szilagyi Maria
Published: August 2012

Aliphatic carboxylic acids include a very wide range of chemicals that perform a diverse range of industrial functions. Many occur naturally and serve an important function in nutrition, and others are intermediates in normal biochemical processes. This chapter is limited to a discussion of the saturated aliphatic mono‐ and polycarboxylic acids. Because of the wide range of uses, the differing circumstances of isolation and often the complexity of structure, many organic acids are described by a variety of names. In this chapter, the names used in the text are usually the trivial or most common names; alternative names are given for reference. A current systematic or Chemical Abstracts acid name is given in the tables that describe physicochemical properties. The commercial and industrial importance of this class of compounds is indicated by recent production figures: formic acid has a production volume in excess of 1 billion lb/year, acetic acid has a production volume in the region of 3.3 billion lb/year, acrylic acid in excess of 1 billion lb/year, and propionic acid on the order of 100 million lb/year. Esters and salts of organic acids are also produced in large volumes.

In general, serious physiological concerns for humans do not arise from the acids discussed in this chapter. Occasionally, concerns have been reported for individual acids, but usually with very high experimental or accidental exposures. The low level of concern associated with most of these acids is attested to by many members of this class that are used as food additives, flavoring agents, and stabilizers, or as food materials. The primary adverse effect of exposure to aliphatic carboxylic acids is usually acute arising from their primary irritant effects on skin, eyes, and mucous membranes, particularly of the short‐chain acids. As the molecular weight increases and the water solubility decreases, the irritating capacity of a carboxylic acid generally decreases. In addition, skin sensitization is quite rare with the aliphatic carboxylic acids.
Esters of Carbonic and Orthocarbonic Acid, Organic Phosphorous, Monocarboxylic Halogenated Acids, Haloalcohols, and Organic Silicon
Authors: Toscano William A. , Coleman Kelly P.
Published: August 2012

This chapter covers (1) esters of carbonic and orthocarbonic acid, (2) esters of organic phosphorous compounds, (3) esters of monocarboxylic halogenated acids, alkanols, or haloalcohols, and (4) organic silicon esters. Other classes of esters are summarized in Chapters 57 and 58. Refer to the Introduction in Chapter 57 for a more detailed overview of general properties of esters.

Unfortunately, as shown in the two prior chapters, mainly fragmented toxicological evaluations are available for esters. Most of these esters are characterized by low toxicity. Indeed, as expressed in Chapter 57, lethal dose (e.g., LD50) values are frequently difficult or impractical to measure. Localized dermal irritation is one common effect characteristic of exposures to most organic solvents. Few esters are readily absorbed, but there are exceptions, such as tri‐o‐cresyl phosphate (TOCP). Several of the halogenated derivatives, such as ethylchloro‐ and ethylbromo‐, are potent lacrimators. Ethyl fluoroacetate and fluoroacetic acid exhibit about the same mode of action, which may indicate that the acetate is rapidly hydrolyzed and metabolized in the mammalian system. The unsaturated carbonates are also associated with high lacrimatory activity.

TOCP is an example of an ester that can cause neuropathy in a variety of animal species. The initial weakness and paralysis are normally reversible in early stages, but repeated or massive assaults result in demyelination of the nerve fibers. The mechanism of action is not yet certain, but it appears to involve phosphorylation of proteins. Only selected phosphates exhibit neuropathic effects, including diisopropyl fluorophosphorate andN,N′‐diisopropyl phosphorodiamidic fluoride.

As was expressed in Chapter 57, industrial hygiene evaluation of esters involves collecting and analyzing air samples to determine their airborne concentrations. Published industrial hygiene air sampling and analytical methods, however, are unavailable for most esters. In relation, there are few occupational exposure and biological limits. A list of ester compounds covered in this chapter that have industrial hygiene sampling and analytical methods are presented here along with their respective occupational exposure limits, established by the American Conference of Governmental Industrial Hygienists (ACGIH), the Occupational Safety and Health Administration (OSHA), and the National Institute for Occupational Safety and Health (NIOSH). As stated in Chapter 57, since sampling and analytical methods and occupational exposure limits are subject to periodic revision, the reader is encouraged to refer to current publications of ACGIH, OSHA, and NIOSH.
Glycols
Authors: Cavender Finis L.
Published: August 2012

Glycols or diols are hydrocarbons that have two hydroxyl groups attached to separate carbons in an aliphatic chain or alicyclic ring. They are used as antifreeze agents, heat transfer agents, deicing agents, cryoprotectants, humectants, solvent carriers, chemical intermediates, components of polymers and resins, and vehicles in a number of chemical formulations including cosmetic and pharmaceutical preparations. They vary from slightly viscous liquids to waxy solids, are soluble in water, alcohols, and ketones, and are insoluble in hydrocarbons.

They have low vapor pressures; therefore inhalation of vapors and aerosols is of little concern unless they are heated, agitated, or sprayed. They have little or no odor; thus only their irritancy at high concentrations is a warning property.

Because of the irritant properties and the potential for central nervous system (CNS) depression at high concentrations, the occupational exposure limit (OEL) for glycols is generally set as a ceiling limit. The chemical and physical properties of several of the more common glycols are given.
Synthetic Polymers—Olefin, Diene Elastomers, and Vinyl Halides
Authors: Walker Bailus , Stokes Lynette D.
Published: August 2012

The present chapter discusses polymers of olefin, elastomers, and vinyl halides. Olefin fibers (polypropylene and polyethylene) are products of the polymerization of propylene and ethylene gases and show resistance to moisture and chemicals. Elastomer is a polymer with properties of elasticity. It has been reported that ethylene‐propylene elastomers generally have low toxicity. Some of these polymers have received FDA approval for pharmaceutical applications. It has been found that synthetic rubber–any type of artificially made polymer material that exhibits elastomeric behavior–is of primary concern in terms of use or application. Vinyl halides are any alkenes with at least one halide substituent bonded directly to one of the unsaturated carbons. They are easily polymerized and copolymerized with various materials such as acrylonitrile, vinyl acetate, and styrene, to form pliable, lightweight plastics or thermoplastic resins that have characteristics such as increased resistance to water, oils, and solvents, plus other distinctive properties Several reports address worker health problems associated with these polymers and recommend the standards for their workplace practice.
Polyurethanes, Miscellaneous Organic Polymers, and Silicones
Authors: Cragg Steven T.
Published: August 2012

The toxicity of the polymers discussed in this chapter may be attributed generally to the residual monomers, catalysts, and other additives present rather than the polymerper se. The cured polymer itself may be of high molecular weight and, consequently, more or less toxicologically inert. Carefully manufactured, highly refined polymers contain few residual toxic chemicals. However, some of the polymers discussed in this chapter, at least in some applications, go through an intermediate stage consisting of “prepolymers” (sometimes referred to as oligomers or resins) that react further to achieve their final, cured form. These may have high levels of monomers or additives that could present an exposure hazard to workers.
Organic Sulfur Compounds
Authors: Shertzer Howard G.
Published: August 2012

Sulfur‐containing materials are widespread in the environment and are essential for survival of mammals and other species. Methyl and ethyl mercaptans are extremely important in fundamental biological processes such as a source of sulfur or carbon fragments in mammalian biosynthetic pathways. Sulfur‐containing chemicals have toxic properties which may be attributed generally to their chemical, physical and biochemical properties, including their ability to react with heavy metals. The chemicals have been grouped according to chemical classes, with a major focus on mercaptans (also called thiols or sulfhydryls), sulfides, chemicals with both sulfur and oxygen atoms (sulfoxides, sulfones, sulfonates, and sulfonyl chlorides), miscellaneous groups (thiophenes and benzothiazoles), and sulfur mustards. The physical and chemical properties, exposure assessment, regulations and standards have been reviewed extensively.
Noise and Ultrasound
Authors: Clark William W. , Cox Jerome R.
Published: August 2012

Noise is America's most widespread nuisance. But excessive noise is more than just a nuisance. Day and night, at home or at work or play, excessive noise exposures annoy individuals, produce stress, impair our ability to communicate, interfere with work and play activities, and, in high enough doses, produce permanent damage to the auditory system that can lead to significant hearing loss.

Although annoyance caused by noise affects all of us to some degree, this chapter describes the effects of excessive noise on our ability to hear, and on the effects of ultrasonic stimulation on tissue. The chapter is organized in four sections. In the first, consideration is given to the physical characteristics of sound and the measurement of noise exposure. The second section considers the effects of excessive noise exposure within the range of human hearing, approximately 20 Hz to 20 kHz. In the third section, a review of the effects of infrasonic exposure (<20 Hz) is provided. And, finally, the last section reviews the effects of exposure to ultrasound (20 kHz to 20 μHz) on humans.

Engineers and scientists are concerned with sound as an energy that can be measured and quantified; no consideration is usually given to whether the sound can be perceived by humans or not. However, hearing health professionals are usually concerned about theeffectsof sound on humans: what and how we hear, what sounds please us, what sounds annoy us, what sounds interfere with our ability to communicate with each other and impair our productivity and work safety, and what sounds can be damaging to our hearing. These effects require different measures than “simple” quantitative descriptions of acoustic energy, and often are expressed in perceptual terms, like “loudness” or “pitch.”
Radio‐Frequency and Microwave Radiation
Authors: Hitchcock R. Timothy
Published: August 2012

Radio‐frequency radiation (RFR) is a type of nonionizing electromagnetic energy. Electromagnetic energy is the propagation of energy by time‐varying electric and magnetic fields. The fields are described by three vector quantities: electric‐field strength, magnetic‐field strength, and propagation vector. Typically, electric and magnetic fields are characterized at right angles to one another and to the direction of motion of the radiation, which is defined by the propagation vector.

Radiation may be described by frequency, wavelength, and photon energy. RFR is nonionizing because the photon energy in this spectral region is not sufficient to ionize matter. However, by convention, RFR is described by frequency. Frequency is the number of wave cycles that pass a point in space in a second (s), and the unit is the hertz (Hz). Sometimes, the interaction of RF energy with matter is described by the wavelength, which is the length of one complete wave cycle.

For the purposes of this chapter, the boundaries of the RF spectral region are 3 kilohertz (kHz) to 300 gigahertz (GHz). Usually, microwave radiation is considered a subset of RFR; however, an alternate convention treats radiowave and microwave radiation as two spectral regions.

Sources of RFR are both natural and man‐made. Natural sources include terrestrial and extraterrestrial sources, and even the human body. Major man‐made sources are shown reviews are available. The source that has most consistently demonstrated the potential for overexposure during normal use is the unshielded dielectric heater (also called plastic sealers). Induction heaters have demonstrated the potential for overexposures to the magnetic field. Certain maintenance activities associated with broadcasting and radar have the potential for overexposure.

This chapter surveys the effect of long‐term studies, ocular effects, behavioral effects, reproductive and developmental effects, and cancer. For the interested reader, reviews of biological effects are available.
Metalworking Fluids (
MWF
)
Authors: Mirer Franklin E.
Published: August 2012

The present chapter summarizes metalworking fluid (MWF). MWF is the term also used for fluids used in various processes and operation for the manufacture of engines, transmissions, and chassis parts. There are two general categories and four major types of MWF. The characteristics and composition of fluids, as well as technological details of application have been reviewed. The experimental evidence suggests that several agents known to be present in MWF have been classified as carcinogenic. Studies also identified the associations of both straight oil and water‐reduced MWF with several respiratory diseases. NIOSH and the OSHA Metalworking Fluids Standards Advisory Committee have reviewed the health hazards and protective measures.
Microstructure and Magnetic Properties of FeNiCuMnTiSnx High Entropy Alloys
Authors: Liu Liang , Zhu Jian Bo , Li Jian Chen , Jiang Qing
Published: August 2012

FeNiCuMnTiSnx multicomponent alloys (x = 0, 0.05, 0.1, 0.5, and 1 where x denotes the adding amount in atomic percentage when other elements are taken as 1) are prepared by an arc furnace. The results show that the crystal structure of FeNiCuMnTiSnx alloys transforms from mixed intermetallic compounds to a single crystal structure (zinc blende structure) with the increasing of Sn content. The magnetization of the FeNiCuMnTiSnx alloys gradually increases from 0.34 to 15.8 emu · g−1 with the increasing x, the magnetic transformation undergoes from the paramagnetism (x = 0, 0.05, 0.1) to superparamagnetism (x = 0.5) finally to soft magnetism (x = 1) at room temperature. We use computer simulation and find that the magnetism of alloys appears when Fe atoms replace Ni atoms.
On the Estimation of True Hall–Petch Constants and Their Role on the Superposition Law Exponent in Al Alloys
Authors: Thangaraju Shanmugasundaram , Heilmaier Martin , Murty Budaraju Srinivasa , Vadlamani Subramanya Sarma
Published: August 2012

Hall–Petch (HP) relation and the superposition of different strengthening mechanisms in different aluminum alloys with grain sizes in the range of 50 nm–70 µm were analyzed. HP parameters as high as σ0 ≈ 200 MPa and kHP ≈ 0.14 MPa m1/2 were observed when the HP relation was fitted directly using the experimentally measured yield strength values. In contrast, considering only the grain size strengthening (by subtracting other strengthening contributions), HP constants of σ0 ≈ 10 MPa and kHP ≈ 0.06 MPa m1/2 were obtained over wide range of grain sizes for the case of a linear superposition of the various strengthening mechanisms present. This is in excellent accord with the values obtained for pure Al justifying the chosen superposition exponent of n equal unity for the different alloys investigated.
Syntactic Iron Foams – On Deformation Mechanisms and Strain‐Rate Dependence of Compressive Properties
Authors: Peroni Lorenzo , Scapin Martina , Avalle Massimiliano , Weise Jörg , Lehmhus Dirk , Baumeister Joachim , Busse Matthias
Published: August 2012

Syntactic iron foams are produced by metal injection moulding from pure Fe powder and two grades of commercial glass microspheres. Mechanical performance of samples containing 5/10/13 wt% of microspheres is compared to unfilled reference material properties at strain‐rates covering 6 orders of magnitude, including Split Hopkinson Pressure Bar (SHPB) experiments. Complex mechanical behavior including strengthening effects of microspheres leading to a plateau strength level which is nearly independent of porosity as well as strain‐rate sensitivity of compressive properties are observed. Typical plateau onset stress levels exceed equivalent characteristics of most comparable cellular metallic materials, reaching between approximately 220 and 270 MPa under quasi‐static conditions, depending on amount and type of added microspheres. A qualitative explanation of significant events in the deformation sequence as reflected in the stress–strain‐curve is offered and discussed in the context of existing studies on syntactic foams. A course for further investigations to verify this hypothesis is suggested.