Data Descriptor : Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

Cloud condensation nuclei (CCN) number concentrations alongside with submicrometer particle number size distributions and particle chemical composition have been measured at atmospheric observatories of the Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS) as well as other international sites over multiple years. Here, harmonized data records from 11 observatories are summarized, spanning 98,677 instrument hours for CCN data, 157,880 for particle number size distributions, and 70,817 for chemical composition data. The observatories represent nine different environments, e.g., Arctic, Atlantic, Pacific and Mediterranean maritime, boreal forest, or high alpine atmospheric conditions. This is a unique collection of aerosol particle properties most relevant for studying aerosol-cloud interactions which constitute the largest uncertainty in anthropogenic radiative forcing of the climate. The dataset is appropriate for comprehensive aerosol characterization (e.g., closure studies of CCN), model-measurement intercomparison and satellite retrieval method evaluation, among others. Data have been acquired and processed following international recommendations for quality assurance and have undergone multiple stages of quality assessment.Peer reviewe

Potential modulation reflectance of passivated type 304 stainless steel in sulfuric acid solution

Potential modulation reflectance (PMR) was applied to passivated type 304 stainless steel covered by a passive oxide film in 0.1 mol dm^[-3] sulfuric acid solution. The ellipsometry measurements showed that the passive oxide film was 1.0 nm thick at the beginning of passivation at 0.1 V vs. Ag/AgCl and increased to 1.8 nm with potential at 0.9 V in the transpassive region. Under positive bias, the signal intensity of PMR was proportional to the capacitance of the space charge formed in the n-type semiconducting passive oxide. The Mott-Schottky type plot was applicable to PMR as well as capacitance. From the plots the oxide film was found to behave as an n-type semiconducting layer. A threshold photon energy of 2.4 eV in the PMR-wavelength relation may correspond to the optical absorption edge of the passive oxide

Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures

In order to clarify the adsorption behavior of cationic surfactants on the air/aqueous electrolyte solution surface, we derived the theoretical equation for the surface tension. The equation includes the electrical work required for charging the air/water surface and the work attributable to the configurational entropy in the adsorbed film. By fitting the equation to the experimental data, we determined the binding constant between adsorbed surfactant ion and counterion, and found that the bromide ions, rather than the chloride ions, are preferentially adsorbed by the air/water surface. Furthermore, it was suggested that the contribution of configurational entropy to the surface tension is predominant in the presence of electrolytes because of the increase in the surface density of surfactant molecules associated with decreasing the repulsive interaction between their hydrophilic groups

Simple and Rapid Conductive Preparation of Wet Biological Samples for SEM Observation: Use of an Asymmetrical Choline-like Room Temperature Ionic Liquid as a Visualizing Agent

In this study, we prepared a hydrophilic, choline-like room temperature ionic liquid (RTIL), and investigated its use as an electroconductive pretreatment for scanning electron microscopy (SEM) investigations of wet biological samples. Wet biological samples generally require pretreatment before SEM observation because of their properties. Conventional pretreatment methods consist of multiple tedious steps that take from several hours, to a day or more. In contrast, our pretreatment only requires the samples to be immersed in an RTIL. This gives the sample suitable electroconductivity for SEM analysis, which can then be carried outperformed rapidly. In addition, samples pretreated with RTILs can remain wet even in the vacuum chamber of SEM. This property allows morphological observation of wet biological samples in "a life-like manner" because our method avoids the chemical fixation, dehydrogation and drying processes required by conventional pretreatment. Moreover, some samples can be successfully visualized after pretreatment using RTILs without dilution. These results suggest that this method can allow simple and rapid conductive pretreatment of wet biological and insulating samples without optimizing their concentrations

Analysis of Polymer Layers on Red Blood Cell Surfaces with Soft Particle Models

International audienc