bluuebunny/crossref_metadata_2025_split huggingface dataset:
Method for the determination of cadmium and its inorganic compounds in workplace air using ICP mass spectrometry after acid digestion [Air Monitoring Methods, 2017]
Authors: Timm K. , Brock T.H. , Hebisch R. , Hartwig A. ,   MAK Commission
Published: October 2017

Abstract

This analytical procedure is a validated measurement method for the determination of cadmium and its inorganic compounds in workplace air averaged over the sampling period after personal or stationary sampling. Sampling is performed by drawing a defined volume of air through a membrane filter located in the sampling head (GSP and FSP) of the sampling device using a suitable flow‐regulated pump. The flow rate is set to 10 L/min with a recommended air sample volume of 1200 L. The collected cadmium is prepared by unpressurised acid digestion and analysed by means of mass spectrometry with inductively coupled plasma (ICP‐MS). The quantitative determination is based on a calibration function obtained by means of an equidistant 10‐point calibration. The absolute limit of quantification (LOQ) is 0.1 µg/L and the relative LOQ is 0.007 µg/m
3
based on an air sample volume of approx. 1.2 m
3
. The mean recovery is 102% and the expanded uncertainty for cadmium in inhalable dusts is approx. 19% and approx. 26% in respirable dusts.

Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working group “Air Analyses” of the Permanent Senate Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
1‐Chlor‐2,3‐epoxypropan (Epichlorhydrin) [BAT Value Documentation in German language, 2017]
Authors: Göen T. , Bader M. , Drexler H. , Hartwig A. ,   MAK Commission
Published: October 2017

AbstractThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated EKA (exposure equivalents for carcinogenic substances) for epichlorohydrin (CAS‐No 106‐89‐8) in 2017. Available publications are described in detail.In rodents, epichlorohydrin induces malignant lymphomas, hyperplasias, forestomach papillomas and carcinomas, subcutaneous fibromas and lung and pituitary tumours. Epichlorohydrin was classified in category 2 for carcinogenic substances. The substance can easily pass through the skin, so biological monitoring is indicated for a valid individual risk assessment.In several biomonitoring studies the mercapturic acids derivatives N‐acetyl‐S‐(3‐chloro‐2‐hydroxypropyl)‐L‐cysteine (CHPMA) and N‐acetyl‐S‐(2,3‐dihydroxypropyl)‐L‐cysteine (DHPMA) in urine as well as the hemoglobin adducts N‐(3‐chloro‐2‐hydroxypropyl)valine and N‐(2,3‐dihydroxypropyl)valine are suggested as biomarkers after epichlorohydrin exposure. Validated analytical procedures for their quantification are available. Data of a correlation of epichlorohydrin in the air and the CHPMA‐excretion in urine were considered for the evaluation of exposure equivalents for carcinogenic substances. Sampling time is at the end of exposure or end of shift and after long term exposure at the end of the shift after several shifts.
Beryllium und seine anorganischen Verbindungen – Bestimmung von Beryllium in Urin mittels Atomabsorptionsspektrometrie [Biomonitoring Methods in German language, 2017]
Authors: Paul R. , Budnik L.T. , Göen T. , Hartwig A. ,   MAK Commission
Published: October 2017

AbstractThe working group „Analyses in Biological Materials“ of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the present biomonitoring method.This procedure describes a method for the determination of beryllium in urine by means of atomic absorption spectrometry using the graphite furnace technique with a pyrolytically coated graphite tube and Zeeman background correction. The acidified samples are homogenized and injected into the graphite tube without further sample preparation using an autosampler. Magnesium nitrate is used as a matrix modifier. After drying, pyrolysis and atomization, the absorbance is measured at 234.9 nm. The beryllium concentration is quantified using either a calibration curve (method I) or the standard addition method (method II).The method was extensively validated and the reliability data were confirmed by independent laboratories, which have established and cross‐checked the whole procedure.
Triethanolamine [MAK Value Documentation, 2010]
Authors: Hartwig A. ,   MAK Commission
Published: October 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated triethanolamine [
102‐71‐6
], considering all toxicological endpoints. Available publications and unpublished study reports are described in detail.

After single application, triethanolamine was not found to have any relevant irritation potential for the skin or mucous membranes. The systemic toxicity of triethanolamine via all routes of exposure is low. A 28‐day inhalation study in rats with aerosol exposure revealed a LOAEC of 20 mg/m
3
for inflammation of the larynx, the most sensitive toxicological end point. A benchmark calculation for focal laryngeal inflammation yielded a BMDL of 14.8 mg/m
3
for male rats and 14.1 mg/m
3
for female rats and the maximum concentration at the work place (MAK value) is set at 5 mg/m
3
which also provides protection from systemic effects caused by triethanolamine.

Since the critical effect is local, Peak Limitation Category I is designated, with an excursion factor of 4 because the effects on the larynx were observed only after prolonged exposure to 20 mg/m
3
and triethanolamine had, if at all, a very low acute irritative potency.

There are no conclusive studies on developmental toxicity available. Triethanolamine is therefore classified in Pregnancy Risk Group D.
Triethanolamine is not genotoxic in vitro or in vivo; there is no evidence of germ cell mutagenicity. Oral and dermal studies in rats and mice yielded no evidence of a carcinogenic potential.
Skin contact is not expected to contribute significantly to systemic toxicity.
The sensitizing potency of triethanolamine is only very slight. Triethanolamine has therefore not been designated with “Sh” or “Sa” (for substances which cause sensitization of the skin or airways).
Triethanolamine [MAK Value Documentation, 2016]
Authors: Hartwig A. ,   MAK Commission
Published: October 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of triethanolamine [
102‐71‐6
], considering the endpoints respiratory tract irritation and developmental toxicity.

Critical effect of triethanolamine is respiratory tract irritation (focal larynx inflammation). The previous MAK value of 5 mg/m
3
is based on 5‐day and 28‐day aerosol studies in rats with a LOAEC of 20 mg/m
3
. A benchmark calculation gives a BMDL05 of 14,1 mg/m
3
. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. Based on this approach, a concentration of 4,7 mg/m
3
for the work place air can be calculated from this BMDL05. Therefore the MAK value of 5 mg/m
3
is retained.

As local effects are critical, Peak Limitation Category I is retained. At an excursion factor of 2, the allowable maximum concentration is still below the BMDL05.
NOAEL for fetotoxicity are 300 mg/kg bw and day in rats and 1125 mg/kg body weight and day in mice . Teratogenicity was not tested. Nevertheless, because the calculated margins between NOAEL and MAK value are very high, and alkylamines lack teratogenicity, there is no reason to fear damage to the embryo or foetus when the MAK value is observed. Therefore, triethanolamine is assigned to Pregnancy Risk Group C.
Diazinon [MAK Value Documentation, 2015]
Authors: Hartwig A. ,   MAK Commission
Published: October 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated diazinon [
333‐41‐5
] considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. The critical effect of diazinon is inhibition of the acetylcholinesterase (AChE) at the cholinergic synapses which is measured as AChE activity in erythrocytes and brain. A reduction to 70 and 80% of their respective activities prior to exposure is regarded as adverse. The corresponding NOAELs in subchronic or chronic feeding studies in rats, dogs and monkeys are 0.3, 0.75 and 0.17 mg/kg body weight and day, which are scaled to concentrations of 0.6, 4.5 and 0.7 mg/m
3
, respectively. Taking into account a possible enhancement of the effects over time, the maximum concentration at the workplace (MAK value) of 0.1 mg/m
3
for the inhalable fraction is confirmed. The MAK value is also supported by a 3‐week inhalation study in rats with a NOAEC of 0.46 mg/m
3
.

Since a systemic effect is critical, Peak Limitation Category II is retained. The renal elimination half‐life of the dialkyl phosphate metabolites of diazinon in humans is about 2 hours, so that the corresponding excursion factor of 2 is confirmed.
The NOAELs for developmental toxicity are 1.9 mg/kg body weight and day for rats and 100 mg/kg body weight and day for rabbits. As developmental neurotoxicity is induced only at higher doses, the offspring are less sensitive to the inhibition of AChE than the dams, and the margins between the calculated concentrations without effects and the MAK value are sufficiently large, the classification of diazinon in Pregnancy Risk Group C is retained.
Diazinon is not considered to be genotoxic, and therefore not regarded as a germ cell mutagen. In studies not reaching the maximum tolerated dose, diazinon is not carcinogenic in rats and mice. Skin contact is expected to contribute significantly to systemic toxicity, and diazinon remains designated with an “H”. Limited data in animals do not show a skin sensitizing potential.
Arsenic and its inorganic compounds (with the exception of arsine) [MAK Value Documentation, 2015]
Authors: Bader M. , Hartwig A. ,   MAK Commission
Published: October 2017

AbstractThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the data available for absorption through the skin for arsenic [7440‐38‐2] and its inorganic compounds including gallium arsenide [1303‐00‐0]. Available publications are described in detail.Dermal penetration has been demonstrated for pentavalent arsenic compounds, and it can also be assumed for trivalent arsenic compounds. The extent of skin penetration depends on the solubility of the substance. Arsenic and its inorganic compounds are classified in Category 1 for Carcinogenic Substances and in Category 3 A for Germ Cell Mutagens. No MAK value (maximum concentration at the workplace) could be established. No safe concentration range can therefore be estimated, so that an increased carcinogenic or genotoxic risk should be assumed even for low amounts absorbed percutaneously. Therefore, inorganic arsenic compounds, with the exception of arsenic itself and gallium arsenide, which are both very poorly soluble in water, are designated with an “H” (for substances that can be absorbed through the skin in toxicologically relevant amounts).
Barium sulfate (respirable fraction) [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: October 2017

Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated barium sulfate [
7727‐43‐7
]. Barium sulfate is a biopersistent granular dust. Therefore, the respirable fraction of barium sulfate dust has been classified in Carcinogen Category 4 and a MAK value of 0.3 mg/m³ × material density was established for the respirable fraction in analogy to the other biopersistent granular dusts. This classification is based on animal data that showed increased tumor incidences in rats exposed to biopersistent granular dusts in the high dose range. These tumors are regarded to be a consequence of the inflammatory mechanism of action, for which thresholds can be defined. Direct genotoxic effects appear to be of subordinate relevance for the carcinogenicity of biopersistent granular dusts. In analogy to biopersistent granular dusts the Peak Limitation Category II was established for barium sulfate with an excursion factor of 8. Since barium sulfate is not systemically distributed and accumulates only locally in the lungs, no developmental effects due to this dust are expected to occur at the MAK value of 0.3 mg/m³ × material density (respirable, R‐fraction). Barium sulfate has accordingly been classified in Pregnancy Risk Group C. Barium sulfate is not designated with either “Sa” or “Sh” or “H”.
Connected cruise control with delayed feedback and disturbance: An adaptive dynamic programming approach
Authors: Huang Mengzhe , Gao Weinan , Jiang Zhong‐Ping 
Published: October 2017

SummaryThis paper studies the connected cruise control problem for a platoon of human‐operated and autonomous vehicles. The autonomous vehicles can receive motional data, ie, headway and velocity information from other vehicles by wireless vehicle‐to‐vehicle communication. The use of wireless communications in information exchange between vehicles inevitably causes input delay in the platooning system. Meanwhile, unpredictable behaviors of the leading vehicle constitute exogenous disturbance for the system. An adaptive optimal control problem with input delay and disturbance is formulated, and a novel data‐driven control solution is proposed such that each vehicle in the platoon can achieve safe distance and desired velocity. By adopting an adaptive dynamic programming technique with sampled‐data system theory, a data‐driven adaptive optimal control approach is proposed for autonomous vehicles by the learning strategies of policy iteration without the accurate knowledge of the dynamics of all human drivers and vehicles. The efficacy of the proposed controller is substantiated by rigorous analysis and validated by simulation results in different scenarios.
High Mobility WS2 Transistors Realized by Multilayer Graphene Electrodes and Application to High Responsivity Flexible Photodetectors
Authors: Aji Adha Sukma , Solís‐Fernández Pablo , Ji Hyun Goo , Fukuda Kenjiro , Ago Hiroki 
Published: October 2017

AbstractThe electrical contact is one of the main issues preventing semiconducting 2D materials to fulfill their potential in electronic and optoelectronic devices. To overcome this problem, a new approach is developed here that uses chemical vapor deposition grown multilayer graphene (MLG) sheets as flexible electrodes for WS2 field‐effect transistors. The gate‐tunable Fermi level, van der Waals interaction with the WS2, and the high electrical conductivity of MLG significantly improve the overall performance of the devices. The carrier mobility of single‐layer WS2 increases about a tenfold (50 cm2 V−1 s−1 at room temperature) by replacing conventional Ti/Au metal electrodes (5 cm2 V−1 s−1) with the MLG electrodes. Further, by replacing the conventional SiO2 substrate with a thin (1 µm) parylene‐C flexible film as insulator, flexible WS2 photodetectors that are able to sustain multiple bending stress tests without significant performance degradation are realized. The flexible photodetectors exhibited extraordinarily high gate‐tunable photoresponsivities, reaching values of 4500 A W−1, and with very short (<2 ms) response time. The work of the heterostacked structure combining WS2, graphene, and the very thin polymer film will find applications in various flexible electronics, such as wearable high‐performance optoelectronics devices.
Calcium Phosphate–Collagen Scaffold with Aligned Pore Channels for Enhanced Osteochondral Regeneration
Authors: Seong Yun‐Jeong , Kang In‐Gu , Song Eun‐Ho , Kim Hyoun‐Ee , Jeong Seol‐Ha 
Published: October 2017

AbstractThis study reports the development of a bilayered scaffold with aligned channels produced via a sequential coextrusion and unidirectional freezing process to facilitate upward bone‐marrow stem‐cell migration. The biomimetic scaffold with collagen and biphasic calcium phosphate (BCP) layers is successfully fabricated with matching of the cartilage and bone layers. The aligned structure results in an enhancement of the compressive strength, and the channels enable tight anchoring of the collagen layers on the BCP scaffolds compared with a randomly structured porous scaffold. An in vitro evaluation demonstrates that the aligned channels guide the cells to attach on the surface in highly stretched shapes and migrate upward faster than the random structure. In addition, in vivo assessment reveals that the aligned channels yield superior osteochondral tissue regeneration compared with the random structure. Moreover, the channel diameter greatly affects the tissue regeneration, and the scaffold with a channel diameter of ≈270 µm exhibits the optimal regeneration because of sufficient nutrient supply and adequate tissue ingrowth. These findings indicate that the introduction of aligned channels to a bilayered scaffold provides an effective approach for osteochondral tissue regeneration.
Nanoscale Manipulation of Spinel Lithium Nickel Manganese Oxide Surface by Multisite Ti Occupation as High‐Performance Cathode
Authors: Xiao Biwei , Liu Hanshuo , Liu Jian , Sun Qian , Wang Biqiong , Kaliyappan Karthikeyan , Zhao Yang , Banis Mohammad Norouzi , Liu Yulong , Li Ruying , Sham Tsun‐Kong , Botton Gianluigi A. , Cai Mei , Sun Xueliang 
Published: October 2017

AbstractA novel two‐step surface modification method that includes atomic layer deposition (ALD) of TiO2 followed by post‐annealing treatment on spinel LiNi0.5Mn1.5O4 (LNMO) cathode material is developed to optimize the performance. The performance improvement can be attributed to the formation of a TiMn2O4 (TMO)‐like spinel phase resulting from the reaction of TiO2 with the surface LNMO. The Ti incorporation into the tetrahedral sites helps to combat the impedance growth that stems from continuous irreversible structural transition. The TMO‐like spinel phase also alleviates the electrolyte decomposition during electrochemical cycling. 25 ALD cycles of TiO2 growth are found to be the optimized parameter toward capacity, Coulombic efficiency, stability, and rate capability enhancement. A detailed understanding of this surface modification mechanism has been demonstrated. This work provides a new insight into the atomic‐scale surface structural modification using ALD and post‐treatment, which is of great importance for the future design of cathode materials.
Recent Progress on Antimonene: A New Bidimensional Material
Authors: Ares Pablo , Palacios Juan José , Abellán Gonzalo , Gómez‐Herrero Julio , Zamora Félix 
Published: October 2017

AbstractAntimonene, defined in sensu stricto as a single layer of antimony atoms, is recently the focus of numerous theoretical works predicting a variety of interesting properties and is quickly attracting the attention of the scientific community. However, what places antimonene in a different category from other 2D crystals is its strong spin–orbit coupling and a drastic evolution of its properties from the monolayer to the few‐layer system. The recent isolation of this novel 2D material pushes the interest for antimonene even further. Here, a review of both theoretical predictions and experimental results is compiled. First, an account of the calculations anticipating an electronic band structure suitable for optoelectronics and thermoelectric applications in monolayer form and a topological semimetal in few‐layer form is given. Second, the different approaches to produce antimonene—mechanical and liquid phase exfoliation, and epitaxial growth methods—are reviewed. In addition, this work also reports the main characterization techniques used to study this exotic material. This review provides insights for further exploring the appealing properties of antimonene and puts forward the opportunities and challenges for future applications from (opto)electronic device fabrication to biomedicine.
Efficient Photoelectrochemical O2 and CO Production Using BiVO4 Water Oxidation Photoanode and CO2 Reduction Au Nanoparticle Cathode Prepared by In Situ Deposition from Au3+ Containing Solution
Authors: Zahran Zaki N. , Mohamed Eman A. , Haleem Ashraf Abdel , Naruta Yoshinori 
Published: October 2017

AbstractThe cathodic polarization of various conducting electrodes in a CO2‐saturated DMF/5% H2O solution containing AuCl3 (DMF = N,N‐dimethylformamide) results in in situ deposition of a highly selective and efficient CO2 to CO conversion Au nanoparticle electrocatalyst. These electrodes include glassy carbon, fluorine doped tin oxide (FTO), and Au plate. The efficiency of the Au nanoparticles is enhanced by introducing 1‐ethyl‐3‐methylimidazolium trifluoromethanesulfonate ionic liquid (EMI OTf IL, 10%) to the AuCl3‐containing DMF/5% H2O deposition solution. In addition to the simplicity and novelty of the preparation method, the resultant in situ deposited Au nanoparticle cathode shows superior activity and selectivity for CO2 to CO conversion compared to Au nanoparticles prepared by other techniques. Moreover, the in situ deposited Au nanoparticle electrode is used as a cathode in an n‐type photoelectrochemical cell with a water oxidation BiVO4 photoanode modified with three‐layer water oxidation catalysts [FTO/EMI BiVO4/FeOOH/NiOOH/Co(bpy‐P)2, bpy‐P = 2,2′‐bipyridine‐4,4′‐diphosphonic acid] to achieve efficient solar‐assisted CO and O2 production with 0.78% solar to CO conversion efficiency. The resultant 0.78% efficiency is the highest efficiency obtained toward CO2 to CO conversion in PEC devices without any use of photovoltaic cell as a tandem.
Identifying the Cause of Rupture of Li‐Ion Batteries during Thermal Runaway
Authors: Finegan Donal P. , Darcy Eric , Keyser Matthew , Tjaden Bernhard , Heenan Thomas M. M. , Jervis Rhodri , Bailey Josh J. , Vo Nghia T. , Magdysyuk Oxana V. , Drakopoulos Michael , Di Michiel Marco , Rack Alexander , Hinds Gareth , Brett Dan J. L. , Shearing Paul R. 
Published: October 2017

AbstractAs the energy density of lithium‐ion cells and batteries increases, controlling the outcomes of thermal runaway becomes more challenging. If the high rate of gas generation during thermal runaway is not adequately vented, commercial cell designs can rupture and explode, presenting serious safety concerns. Here, ultra‐high‐speed synchrotron X‐ray imaging is used at >20 000 frames per second to characterize the venting processes of six different 18650 cell designs undergoing thermal runaway. For the first time, the mechanisms that lead to the most catastrophic type of cell failure, rupture, and explosion are identified and elucidated in detail. The practical application of the technique is highlighted by evaluating a novel 18650 cell design with a second vent at the base, which is shown to avoid the critical stages that lead to rupture. The insights yielded in this study shed new light on battery failure and are expected to guide the development of safer commercial cell designs.