Search results for "CONDENSATION"
showing 10 items of 468 documents
Frequent ultrafine particle formation and growth in Canadian Arctic marine and coastal environments
2017
The source strength and capability of aerosol particles in the Arctic to act as cloud condensation nuclei have important implications for understanding the indirect aerosol–cloud effect within the polar climate system. It has been shown in several Arctic regions that ultrafine particle (UFP) formation and growth is a key contributor to aerosol number concentrations during the summer. This study uses aerosol number size distribution measurements from shipboard expeditions aboard the research icebreaker CCGS Amundsen in the summers of 2014 and 2016 throughout the Canadian Arctic to gain a deeper understanding of the drivers of UFP formation and growth within this marine boundary layer. UFP nu…
Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker <i>Amundsen</i> from …
2016
Abstract. Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols) campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned dist…
Microwave-Assisted Synthesis of New Selenazole Derivatives with Antiproliferative Activity
2013
New aryl-hydrazinyl-1,3-selenazole and aroyl-hydrazonyl-1,3-selenazoles were synthesized via Hantzsch type condensation reactions of selenosemicarbazides with α-halogenocarbonyl derivatives, under classical versus microwave heating conditions. Excellent yields and shorter reaction times were obtained under irradiation conditions. The structures of the synthesized compounds were assigned based on spectroscopic data (FT-IR, 1 H-NMR), MS and elemental analysis. Selenazole derivatives were screened for their anti-proliferative effects against two leukemia cell lines (CCRF-CEM and HL60) and three carcinoma cell lines (MDA-MB231, HCT116 and U87MG).
An Overview of the Hypogene Caves of Sicily
2017
Karst in Sicily develops in both Messinian gypsum and Mesozoic or Tertiary limestone rocks. Caves are also found in the basalts of Mount Etna. Except for some rare cases, until recently most caves developed in limestone were considered to be of epigenetic origin. The discovery of gypsum in some of these caves, and especially detailed morphological studies, have allowed defining a hypogenic origin for a dozen of caves up to now. In some of these, the hypogenic evidences are very clear, while others remain in doubt because of the widespread presence of well-developed condensation-corrosion morphologies not necessarily related to hydrothermal fluids. This paper reports the present knowledge of…
DNA condensation with spermine dendrimers: interactions in solution, charge inversion, and morphology control
2011
In this report, we characterize the formation of structured condensates of 884 base pair, double stranded DNA and spin-labeled, second generation dendrons (SL-G2) that are spermine-based and cationic using continuous wave electron paramagnetic resonance spectroscopy (CW EPR) and transmission electron microscopy (TEM). The electrostatic interaction between DNA and SL-G2 in solution leads to condensation of DNA into densely packed structures. At a particular charge ratio of 2.3 (cationic charges/anionic charges), the structures appear as thick rod-like condensates of parallelly ordered, stretched DNA and SL-G2. Depending on the concentration of DNA, the charge ratio and the ionic strength, wh…
L'impact méconnu des chauves-souris et du guano dans l'évolution morphologique tardive des cavernes
2016
The little known impact of bats and bat guano in the late stages of cave morphogenesis. Bats are considered as symbolic caves inhabitants. The colonies, sometimes huge, may occupy caves through long periods. Large guano deposits were accumulated. Some have been mined for phosphates, either by hand or at the industrial scale. Bats impact is triple: breathing releases CO2, urine is corrosive, and guano mineralization releases acids (carbonic, nitric, sulfuric, and phosphoric). Such aggressive compounds have an effect on carbonate rock and flowstones, either by direct ground corrosion at the contact of the guano, or by condensation-corrosion on walls and ceilings. The speleogenetic impact of t…
ChemInform Abstract: Dialkylimidazolium Dimethyl Phosphates as Solvents and Catalysts for the Knoevenagel Condensation Reaction.
2014
Knoevenagel condensation between benzaldehyde and ethyl cyanoacetate in the presence of an equimolar amount of 1,3-dialkylimidazolium dimethyl phosphate ionic liquids is investigated.
Finite Size Effects in Thin Film Simulations
2003
Phase transitions in thin films are discussed, with an emphasis on Ising-type systems (liquid-gas transition in slit-like pores, unmixing transition in thin films, orderdisorder transitions on thin magnetic films, etc.) The typical simulation geometry then is a L xL x D system, where at the low confining L x L surfaces appropriate boundary “fields” are applied, while in the lateral directions periodic boundary conditions are used. In the z-direction normal to the film, the order parameter always is inhomogeneous, due to the boundary “fields” at the confining surfaces. When one varies the temperature T from the region of the bulk disordered phase to a temperature below the critical temperatu…
The droplet evaporation/condensation transition in a finite volume
2003
A fluid in the NVT ensemble at T less than the critical temperature T_c and rho = N/V somewhat in excess of rho_coex (density of the saturated gas in the gas-liquid transition) is considered. For V->infinity, a macroscopic liquid droplet coexists with surrounding saturated gas according to the lever rule. For finite V, droplets can only exist if they exceed a minimum size. A (rounded) first order transition of the system occurs when the droplet evaporates into the supersaturated gas.Simulation evidence for this transition is given for a Lennard-Jones model and interpreted by a phenomenological theory. At the transition, the chemical potential difference mu_t-mu_coex scales like L^(-d/(d+…
Insights into the production of upgraded biofuels using Mg-loaded mesoporous ZSM-5 zeolites
2020
9 figures, 6 tables.-- Supplementary information available.-- https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html