Searching for cavities of various densities in the Earth's crust with a low-energy electron-antineutrino beta-beam

We propose searching for deep underground cavities of different densities in the Earth's crust using a long-baseline electron-antineutrino disappearance experiment, realized through a low-energy beta-beam with highly-enhanced luminosity. We focus on four cases: cavities with densities close to that of water, iron-banded formations, heavier mineral deposits, and regions of abnormal charge accumulation that have been posited to appear prior to the occurrence of an intense earthquake. The sensitivity to identify cavities attains confidence levels higher than $3\sigma$ and $5\sigma$ for exposures times of 3 months and 1.5 years, respectively, and cavity densities below 1 g cm$^{-3}$ or above 5 g cm$^{-3}$, with widths greater than 200 km. We reconstruct the cavity density, width, and position, assuming one of them known while keeping the other two free. We obtain large allowed regions that improve as the cavity density differs more from the Earth's mean density. Furthermore, we demonstrate that knowledge of the cavity density is important to obtain O(10%) error on the width. Finally, we introduce an observable to quantify the presence of a cavity by changing the orientation of the electron-antineutrino beam, with which we are able to identify the presence of a cavity at the $2\sigma$ to $5\sigma$ C.L.Comment: 7 pages, 5 figures; matches published versio

Interface-Induced Plasmon Nonhomogeneity in Nanostructured Metal-Dielectric Planar Metamaterial

Transformations of the electronic structure in thin silver layers in metal-dielectric (TiAlN/Ag) multilayer nanocomposite were investigated by a set of electron spectroscopy techniques. Localization of the electronic states in the valence band and reduction of electron concentration in the conduction band was observed. This led to decreasing metallic properties of silver in the thin films. A critical layer thickness of 23.5 nm associated with the development of quantum effects was determined by X-ray photoelectron spectroscopy. Scanning Auger electron microscopy of characteristic energy losses provided images of plasmon localization in the Ag layers. The nonuniformity of plasmon intensities distribution near the metal-nitride interfaces was assessed experimentally

Elucidating the Performance Limitations of Alkaline Electrolyte Membrane Electrolysis: Dominance of Anion Concentration in Membrane Electrode Assembly

Anion exchange membrane water electrolyzers (AEMWEs) offer a cost-effective technology for producing green hydrogen. Here, an AEMWE with atmospheric plasma spray non-precious metal electrodes was tested in 0.1 to 1.0 M KOH solution, correlating performance with KOH concentration systematically. The highest cell performance was achieved at 1.0 M KOH (ca. 0.4 A cm−2 at 1.80 V), which was close to a traditional alkaline electrolysis cell with ≈6.0 M KOH. The cell exhibited 0.13 V improvement in the performance in 0.30 M KOH compared with 0.10 M KOH at 0.5 A cm−2. However, this improvement becomes more limited when further increasing the KOH concentration. Electrochemical impedance and numerical simulation results show that the ohmic resistance from the membrane was the most notable limiting factor to operate in low KOH concentration and the most sensitive to the changes in KOH concentration at 0.5 A cm−2. It is suggested that the effect of activation loss is more dominant at lower current densities; however, the ohmic loss is the most limiting factor at higher current densities, which is a current range of interest for industrial applications

Coulomb explosion sputtering of selectively oxidized Si

We have studied multiply charged Arq+ ion induced potential sputtering of a unique system comprising of coexisting Silicon and Silicon oxide surfaces. Such surfaces are produced by oblique angle oxygen ion bombardment on Si(100), where ripple structures are formed and one side of each ripple gets more oxidized. It is observed that higher the potential energy of Arq+ ion, higher the sputtering yield of the non conducting (oxide) side of the ripple as compared to the semiconducting side. The results are explained in terms of Coulomb explosion model where potential sputtering depends on the conductivity of the ion impact sites.Comment: 9 pages and 3 figure

Non-target approach for the determination of novel micropollutants in wastewater using liquid chromatography quadrupole-time of flight mass spectrometry (LC-QTOF-MS)

Wastewaters contain a very large list of micropollutants and transformation products of environmental concern. All these (mostly) synthetic organic chemicals enter the wastewater treatment plants (WWTP) with influents and due to incomplete or zero removal are released in the aquatic environment. Thus, the study of the fate of the emerging pollutants and their transformation products in WWTPs is of paramount environmental importance and can also provide valuable information related to consumption trends. Target screening procedures are limited to a small fraction of these substances, due to the inability to obtain standards for all that substances and the ignorance of the existence of many of them. Recent advances in high resolution mass spectrometry (HRMS) have opened up new windows of opportunity in the field of complex samples analysis. Suspect screening, with suspected substances based on prior information but with no reference standard, is a powerful tool which allows a large increment in the number of compounds to be evaluated. However, in most cases many of the peaks showing greater intensity not correspond to substances included in the target and suspect screening lists. These substances are potentially relevant, due to their high concentration, and their identification is environmentally important. Nevertheless, full identification of unknown compounds is often difficult and there is no guarantee of a successful outcome. The aim of the present work is the development and application of a workflow for the tentative identification of relevant unknown substances (not detected in the previously applied target and suspect methods) using liquid chromatography quadrupole-time-of-flight mass spectrometry (LC–QToF-MS)

PEAKTRAMS: An automated computational approach for the simultaneous detection of features in reverse phase and hilic hrms screening

Comparison of chromatograms obtained in reserved phase (RP) liquid chromatography and hydrophilic interaction liquid chromatography (HILIC) can provide valuable information for the identification and confirmation of suspect and non-target compounds. The plausibility of the obtained chromatographic retention times (RTs) in both modes as well as the ψomparison of the MS/MS spectra are strong points to be considered. This work presents the development of a novel automatic approach for the identification of common peaks between RP and HILIC chromatograms. The core of the program is written in R-project while a simple and user friendly graphical user interface (GUI) was built in JAVA. The first step consists of the introduction of the target chromatograms of the same sample (one obtained by RP and one by HILIC) plus the corresponding blank chromatograms. Blank subtraction was performed first using an algorithm to find in each scan the common m/z features (with a given mass accuracy). This algorithm also considers the RTs (a tolerance interval is applied), so the subtraction takes place even with slight drifts in the RTs between target and blank chromatograms. After blank subtraction, two different lists are obtained with the detected peaks in both RP and HILIC modes. Subsequently, m/z values are compared and matches are listed. The developed workflow was validated with solvent standards and with spiked wastewater samples with a mixture of compounds with a wide range of physicochemical properties. Successful results were obtained for 26 out of the 27 evaluated substances, allowing the recording of the corresponding RTs in both RP and HILIC mode

Identification of unknowns in real wastewater through the application of a LC-QTOF-MS based workflow

Wastewater contains a high number of organic micropollutants and transformation products of environmental concern. Recent approaches, combining methodologies based on target and suspect screening (for suspected substances based on prior information but with no reference standard) are important for the comprehensive characterization of environmental samples. Nevertheless, samples still contain many chromatographic peaks which do not correspond to substances included in target and suspect screening lists. These substances may be potentially relevant (e.g. due to their concentration or potential effects) and thus the identification of selected non-targets is important. However, full identification of unknown compounds is often difficult and there is no guarantee of a successful outcome. The aim of this work is to show some specific examples on the identification of unknown compounds in real wastewater (collected from the WWTP of Athens). Identifications were conducted using a developed integrated workflow based on LC–QToF-MS to detect formerly unknown organic contaminants in wastewater

Studies on the mouldability of structural foams in hybrid moulds

In the context of the research project Hybridmould 21, studies on the mouldability of structural foams using hybrid moulds have been carried out. Hybrid injection moulds are an increasingly considered alternative for prototype series or short production runs of large dimension parts. In this solution for injection moulds the moulding elements (blocks or other inserts) are manufactured in alternative metallic materials or in synthetic materials typically using rapid prototyping techniques. Structural foams, known since the 70s, are moulded by injection moulding without using the high pressures typically used in injection moulding. The formation of the structural foam results from the dispersed gaseous phase, which derives from the expansion of a chemical blowing agent usually compounded in a compatible masterbatch. In this project various thermoplastics and thermosets were used, namely, PP, ABS and PUR, us-ing a hybrid mould instrumented for the monitoring of temperature, pressure and expansion force. The mould-ing block was manufactured by vacuum casting of an epoxy composite. In this paper are mainly discussed the results obtained on liquid injection moulding polyurethane resins in the hybrid mould.QREN contract 2010/013307 – Project Hybridmould 2

A Nexafs Study of Nitric Oxide Layers Adsorbed from a nitrite Solution onto a Pt(111) Surface

NO molecules adsorbed on a Pt(111) surface from dipping in an acidic nitrite solution are studied by near edge X-ray absorption fine structure spectroscopy (NEXAFS), X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) techniques. LEED patterns and STM images show that no long range ordered structures are formed after NO adsorption on a Pt(111) surface. Although the total NO coverage is very low, spectroscopic features in N K-edge and O K-edge absorption spectra have been singled out and related to the different species induced by this preparation method. From these measurements it is concluded that the NO molecule is adsorbed trough the N atom in an upright conformation. The maximum saturation coverage is about 0.3 monolayers, and although nitric oxide is the major component, nitrite and nitrogen species are slightly co-adsorbed on the surface. The results obtained from this study are compared with those previously reported in the literature for NO adsorbed on Pt(111) under UHV conditions