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Ultrafine particles

Qiubo Guo, Yifan Ma, Tingting Chen, Qiuying Xia, Mei Yang, Hui Xia, Yan Yu
Metal sulfides are promising anode materials for sodium-ion batteries due to their large specific capacities. The practical application of metal sulfides in sodium-ion batteries, however, are still limited due to their large volume expansion, poor cycling stability, and sluggish electrode kinetics. In this work, a unique two-dimensional heterostructure of CoSx (CoS and Co9S8) quantum dots embedded N/S-doped carbon nanosheets (CoSx@NSC) is prepared by a facile sol-gel method. The CoSx quantum dots are in-situ formed within ultrafine carbon nanosheets without further sulfidation, thus resulting in ultrafine CoSx particle size and embedded heterostructure...
November 17, 2017: ACS Nano
Tao Hengcong, Jingjing Ding, Chao Xie, Yunnan Gao, Jinliang Song, Zhenyu Sun
We demonstrate a facile and versatile method to grow Ru particles uniformly on pristine few-layer graphene (FLG) in supercritical diethylamine. In particular, a large number of Ru subnanometer clusters less than 1.0 nm were observed. The particle size can be tuned by manipulating the loading content of Ru and controlling the reaction temperature. The resulting Ru/FLG showed remarkably high activity, selectivity, and reusability towards the hydrogenation of levulinic acid to γ-valerolactone. This method is flexible, and can be extended to the synthesis of a variety of other ultrafine metal particles supported on FLG...
November 17, 2017: Nanotechnology
Thuy Chu-Van, Zoran Ristovski, Ali Mohammad Pourkhesalian, Thomas Rainey, Vikram Garaniya, Rouzbeh Abbassi, Sanaz Jahangiri, Hossein Enshaei, U-Shen Kam, Richard Kimball, Liping Yang, Ali Zare, Harry Bartlett, Richard J Brown
This study investigated particle and gaseous emission factors from a large cargo vessel for her whole voyage including at berth, manoeuvring and cruising. Quantification of these factors assists in minimising the uncertainty in the current methods of exhaust gas emission factor estimation. Engine performance and emissions from the main marine engine were measured on-board while the ship was manoeuvring and cruising at sea. Emissions of an auxiliary engine working at 55% of maximum continuous rating (MCR) were measured when the ship was at actual harbour stopovers...
November 13, 2017: Environmental Pollution
Xiuling Zhang, Na Wang, Longlong Geng, Junna Fu, Hui Hu, Dashuai Zhang, Baoyong Zhu, Jesse Carozza, Haixiang Han
Design and synthesis of low-cost catalysts with high activity and stability for hydrogenation reactions is an important research area of applied catalysis. In this work, we present a kind of ultrafine cobalt oxides encapsulated by N-doped carbon (donated as CoOx/CN) as efficient catalysts for hydrogenation of 4-nitrophenol (4-NP) process. The CoOx/CN was fabricated through a pyrolysis strategy using an N-containing metal-organic framework (Co-MOF) as precursor followed by a fine thermal-treatment. With an optimized pyrolysis temperature of 500 °C, the CoOx species present as ultrafine particles highly dispersed in the obtained catalyst (CoOx/CN-500)...
November 7, 2017: Journal of Colloid and Interface Science
Gianluigi De Falco, Chiara Colarusso, Michela Terlizzi, Ada Popolo, Michela Pecoraro, Mario Commodo, Patrizia Minutolo, Mariano Sirignano, Andrea D'Anna, Rita P Aquino, Aldo Pinto, Antonio Molino, Rosalinda Sorrentino
Chronic obstructive pulmonary disease (COPD) is considered the fourth-leading causes of death worldwide; COPD is caused by inhalation of noxious indoor and outdoor particles, especially cigarette smoke that represents the first risk factor for this respiratory disorder. To mimic the effects of particulate matter on COPD, we isolated peripheral blood mononuclear cells (PBMCs) and treated them with combustion-generated ultrafine particles (UFPs) obtained from two different fuel mixtures, namely, pure ethylene and a mixture of ethylene and dimethylfuran (the latter mimicking the combustion of biofuels)...
2017: Frontiers in Immunology
Nay Chi Nway, Yuji Fujitani, Seishiro Hirano, Ohn Mar, Tin-Tin Win-Shwe
Exposure to ambient air pollutants has been reported to have various adverse health impacts. Ambient particulate matter comprises primary particles released directly via engine exhaust and secondary organic aerosols (SOAs) formed from oxidative reactions of the ultrafine particle fraction of diesel exhaust (DE). Toll-like receptor 4 (TLR4) is well known to initiate the inflammatory cascade in the central nervous system. However, whether and how DE and DE-SOA exposure influences TLR4 signaling in the immature brain remains unclear...
October 26, 2017: Neurotoxicology
Wonsik Choi, Dilhara Ranasinghe, J R DeShazo, Jae-Jin Kim, Suzanne E Paulson
Epidemiological studies have shown that exposure to traffic-related pollutants increases incidence of adverse health outcomes. Transit users in cities across the globe commonly spend 15-45 min or more waiting at transit stops each day, often at locations with high levels of pollution from traffic. Here, we investigate the characteristics of concentration profiles of ultrafine particles (UFP) with 5 m spatial resolution across intersections, to determine the best place to site transit stops to minimize exposures...
October 26, 2017: Environmental Pollution
Anna Gasperazzo, Paolo Toffanin, Francesca Larese Filon
BACKGROUND: Green coffee workers can develop allergic symptoms due to green coffee beans (GCB) or to castor bean (CB) that can contaminate sacks used for the transportation. Data are limited in literature and a previous study performed in Trieste demonstrated allergic symptoms in 14.3% of dockworkers handling GCB. OBJECTIVES: To evaluate symptoms and exposure to GCB ultrafine particles in Trieste dockworkers. METHODS: Workers involved in GCB sacks transportation, storage and opening were asked to fill out a questionnaire on allergic respiratory symptoms...
October 27, 2017: La Medicina del Lavoro
Carolyn Klocke, Joshua L Allen, Marissa Sobolewski, Jason L Blum, Judith T Zelikoff, Deborah A Cory-Slechta
Accumulating studies indicate that the brain is a direct target of air pollution exposure during the fetal period. We have previously demonstrated that exposure to concentrated ambient particles (CAPs) during gestation produces ventriculomegaly, periventricular hypermyelination, and enlargement of the corpus callosum (CC) during postnatal development in mice. This study aimed to further characterize the cellular basis of the observed hypermyelination and determine if this outcome, among other effects, persisted as the brain matured...
October 24, 2017: Neurotoxicology
Klara Slezakova, Cátia Peixoto, Marta Oliveira, Cristina Delerue-Matos, Maria do Carmo Pereira, Simone Morais
Fitness centres (FC) represent a unique indoor microenvironment. Exercising on regular basis provides countless health benefits and improves overall well-being, but if these facilities have poor indoor air quality, the respective exercisers might be subjected to some adverse risks. Considering the limited existent data, this work aimed to evaluate particulate pollution (PM10, PM2.5, and ultrafine particles - UFP) in indoor air of FC and to estimate the respective risks for occupants (both staff and exercising subjects)...
October 23, 2017: Environmental Pollution
Han-Jae Shin, Hyun Gi Cho, Chang Kyun Park, Ki Hong Park, Heung Bin Lim
Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity...
October 2017: Toxicological Research
Meihua Bi, Yanan Hao, Jiameng Zhang, Ming Lei, Ke Bi
Polymer nanocomposites are a promising substitute for energy-storage dielectric materials in pulsed power systems. A barium titanate/polyvinylidenefluoride (BT/PVDF) nanocomposite is one of the most widely studied composite systems due to its comprehensive excellent dielectric properties. As the dielectric response of nanocomposites depends strongly on the size of the fillers, in this study, BT/PVDF nanocomposites with 92.3 nm, 17.8 nm and 5.9 nm BT particle fillers are fabricated to reveal the particle size effect of the fillers on the energy storage performance of the polymer nanocomposites...
November 2, 2017: Nanoscale
Akeem O Lawal
Diesel exhaust particles (DEP) are an important component of air particulate matter, generated from the incomplete combustion of fossil fuel in diesel engines. Several epidemiological and experimental data have shown the ability of DEP to induce oxidative stress and pro-inflammatory response as mechanisms in macrophage activation and dysfunction. Macrophages are very important to immunity and immune response due to their ability to phagocyte microbes and parasites. They also respond to toxic chemicals, such as DEP, in the environment and studies have shown that their functions may be impaired by their exposure to DEP...
October 19, 2017: Inflammation
Kyung In Baek, René R Sevag Packard, Jeffrey J Hsu, Arian Saffari, Zhao Ma, Anh Phuong Luu, Andrew Pietersen, Hilary Yen, Bin Ren, Yichen Ding, Constantinos Sioutas, Rongsong Li, Tzung K Hsiai
AIMS: Redox active ultrafine particles (UFP, d < 0.2 μm) promote vascular oxidative stress and atherosclerosis. Notch signaling is intimately involved in vascular homeostasis, in which forkhead box O1 (FOXO1) acts as a co-activator of the Notch activation complex. We elucidated the importance of FOXO1/Notch transcriptional activation complex to restore vascular regeneration after UFP exposure. RESULTS: In a zebrafish model of tail injury and repair, transgenic Tg(fli1:GFP) embryos developed vascular regeneration at 3 days post amputation (dpa), whereas UFP exposure impaired regeneration (p < 0...
November 17, 2017: Antioxidants & Redox Signaling
M Vasyanovich, M Y A Mostafa, M Zhukovsky
Cascade impactors based on inertial deposition of aerosols are widely used to determine the size distribution of radioactive aerosols. However, there are situations where radioactive aerosols are represented by particles with a diameter of 1-5 nm. In this case, ultrafine aerosols can be deposited on impactor cascades by diffusion mechanism. The influence of ultrafine aerosols (1-5 nm) on the response of three different types of cascade impactors was studied. It was shown that the diffusion deposition of ultrafine aerosols can distort the response of the cascade impactor...
September 19, 2017: Radiation Protection Dosimetry
K Skubacz, S Chalupnik, P Urban, M Wysocka
The article presents the advantages of the radon chamber with volume of 17 m3, that belongs to Silesian Centre for Environmental Radioactivity and its applicability for calibration of equipment designed to measure the radon concentration and its short-lived decay products. The chamber can be operated under controlled conditions in the range from -20 to 60°C and relative humidity from 20 to 90%. There is also discussed the influence of aerosol concentration and their size distribution on the calibration results...
September 23, 2017: Radiation Protection Dosimetry
Vicki Stone, Mark R Miller, Martin J D Clift, Alison Elder, Nicholas L Mills, Peter Møller, Roel P F Schins, Ulla Vogel, Wolfgang G Kreyling, Keld Alstrup Jensen, Thomas A J Kuhlbusch, Per E Schwarze, Peter Hoet, Antonio Pietroiusti, Andrea De Vizcaya-Ruiz, Armelle Baeza-Squiban, João Paulo Teixeira, C Lang Tran, Flemming R Cassee
BACKGROUND: A rich body of literature exists that has demonstrated adverse human health effects following exposure to ambient air particulate matter (PM), and there is strong support for an important role of ultrafine (nanosized) particles. At present, relatively few human health or epidemiology data exist for engineered nanomaterials (NMs) despite clear parallels in their physicochemical properties and biological actions in in vitro models. OBJECTIVES: NMs are available with a range of physicochemical characteristics, which allows a more systematic toxicological analysis...
October 10, 2017: Environmental Health Perspectives
Georg Strasser, Stefan Hiebaum, Manfred Neuberger
Mass concentrations PM10, PM2.5, PM1, particle number concentrations of ultrafine particles and lung deposited surface area were measured during commutes with a subway, tram, bus, car and bicycle in Vienna for the first time. Obtained data were examined for significant differences in personal exposure when using various transport modalities along similar routes. Mean PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to buses. Mean PM10, PM2.5 and PM1 mass concentrations were significantly higher in the subway when compared to cars using low ventilation settings...
October 9, 2017: Wiener Klinische Wochenschrift
Fengxia Li, Jürgen Schnelle-Kreis, Josef Cyrys, Erwin Karg, Jianwei Gu, Gülcin Abbaszade, Jürgen Orasche, Annette Peters, Ralf Zimmermann
To investigate the organic composition and their sources of very fine atmospheric particulate matter (PM), size-segregated PM was sampled using rotating drum impactor (RDI) in series with a sequential filter sampler in Augsburg, Germany, from April 2014 to February 2015. Organic speciation analysis and organic carbon/elemental carbon (OC/EC) analysis was performed for the smallest size fraction PM0.36 (PM<360nm). Different OC fractions were determined by thermal optical EC/OC analyzer, and OC2, OC3 and OC4 refer to OC fractions that were derived at 280, 480 and 580°C, respectively...
February 15, 2018: Science of the Total Environment
Matthew P Vannucci, William W Nazaroff
Personal care products (PCP) might be a source of ultrafine particle exposure for users owing to the reaction of ozone with terpene ingredients. The near-person emissions associated with PCP may contribute to exposures that would not be properly accounted for with indoor microenvironmental measurements. To better understand this issue, screening experiments were conducted with 91 PCP to detect the occurrence of ultrafine particle production from exposure to common indoor levels of ozone (23 ± 2 ppb). Twelve products generated measurable particle emissions; quantification experiments were performed for these to determine total particle production and peak particle production rate...
November 7, 2017: Environmental Science & Technology
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