Experimental evidence of parametric decay processes in the variable specific impulse magnetoplasma rocket (VASIMR) helicon plasma source

Decay waves have been observed in the megahertz range in the helium plasma generated by the variable specific impulse magnetoplasma rocket magnetoplasma thruster. They are measured using one of the tips of a triple probe connected to a 50 Ω input of a spectrum analyzer via a dc block (a small capacitor). The maximum amplitude of all waves is in the center of the plasma and does not appear correlated to the radial electron density or temperature profiles. The waves seem to be generated close to the helicon antenna that was 91 cm “upstream” from the measuring Langmuir probe. A possible explanation is parametric decay of the large amplitude helicon wave that also generates the plasma.This project was proudly supported by the International Science Linkages programme established under the Australian Government’s innovation statement Backing Australia’s Ability

Triplet Exciton Generation in Bulk-Heterojunction Solar Cells based on Endohedral Fullerenes

Organic bulk-heterojunctions (BHJ) and solar cells containing the trimetallic nitride endohedral fullerene 1-[3-(2-ethyl)hexoxy carbonyl]propyl-1-phenyl-Lu3N@C80 (Lu3N@C80-PCBEH) show an open circuit voltage (VOC) 0.3 V higher than similar devices with [6,6]-phenyl-C[61]-butyric acid methyl ester (PC61BM). To fully exploit the potential of this acceptor molecule with respect to the power conversion efficiency (PCE) of solar cells, the short circuit current (JSC) should be improved to become competitive with the state of the art solar cells. Here, we address factors influencing the JSC in blends containing the high voltage absorber Lu3N@C80-PCBEH in view of both photogeneration but also transport and extraction of charge carriers. We apply optical, charge carrier extraction, morphology, and spin-sensitive techniques. In blends containing Lu3N@C80-PCBEH, we found 2 times weaker photoluminescence quenching, remainders of interchain excitons, and, most remarkably, triplet excitons formed on the polymer chain, which were absent in the reference P3HT:PC61BM blends. We show that electron back transfer to the triplet state along with the lower exciton dissociation yield due to intramolecular charge transfer in Lu3N@C80-PCBEH are responsible for the reduced photocurrent

Monitoring the Phenolic and Terpenic Profile of Olives, Olive Oils and By-Products throughout the Production Process

Olive oil is a food of great importance in the Mediterranean diet and culture. However, during its production, the olive oil industry generates a large amount of waste by-products that can be an important source of bioactive compounds, such as phenolic compounds and terpenes, revalorizing them in the context of the circular economy. Therefore, it is of great interest to study the distribution and abundance of these bioactive compounds in the different by-products. This research is a screening focused on phytochemical analysis, with particular emphasis on the identification and quantification of the phenolic and terpenic fractions. Both the main products of the olive industry (olives, olive paste and produced oil) and the by-products generated throughout the oil production process (leaf, “alpeorujo”, liquid and solid residues generated during decanting commonly named “borras” and washing water) were analyzed. For this purpose, different optimized extraction procedures were performed for each matrix, followed by high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC-ESI-TOF/MS) analysis. Although no phenolic alcohols were quantified in the leaf and the presence of secoiridoids was low, this by-product was notable for its flavonoid (720 ± 20 μg/g) and terpene (5000 ± 300 μg/g) contents. “Alpeorujo” presented a complete profile of compounds of interest, being abundant in phenolic alcohols (900 ± 100 μg/g), secoiridoids (4500 ± 500 μg/g) and terpenes (1200 ± 100 μg/g), among others. On the other hand, while the solid residue of the borras was the most abundant in phenolic alcohols (3700 ± 200 μg/g) and secoiridoids (680 ± 20 μg/g), the liquid fraction of this waste was notable for its content of elenolic acid derivatives (1700 ± 100 μg/mL) and phenolic alcohols (3000 ± 300 μg/mL). Furthermore, to our knowledge, this is the first time that the terpene content of this by-product has been monitored, demonstrating that it is an important source of these compounds, especially maslinic acid (120 ± 20 μg/g). Finally, the phytochemical content in wash water was lower than expected, and only elenolic acid derivatives were detected (6 ± 1 μg/mL). The results highlighted the potential of the olive by-products as possible alternative sources of a wide variety of olive bioactive compounds for their revalorization into value-added products

FORMULATION OF THE HEAT CONDUCTION EQUATION FOR HETEROGENEOUS MEDIA WITH MULTIPLE SPATIAL SCALES USING REITERATED HOMOGENIZATION

Heterogeneous media with multiple spatial scales are finding increased importance in engineering. An example might be a large scale, otherwise homogeneous medium filled with dispersed small-scale particles that form aggregate structures at an intermediate scale. The objective in this paper is to formulate the strong-form Fourier heat conduction equation for such media using the method of reiterated homogenization. The phases are assumed to have a perfect thermal contact at the interface. The ratio of two successive length scales of the medium is a constant small parameter ε. The method is an up-scaling procedure that writes the temperature field as an asymptotic multiple-scale expansion in powers of the small parameter ε . The technique leads to two pairs of local and homogenized equations, linked by effective coefficients. In this manner the medium behavior at the smallest scales is seen to affect the macroscale behavior, which is the main interest in engineering. To facilitate the physical understanding of the formulation, an analytical solution is obtained for the heat conduction equation in a functionally graded material (FGM). The approach presented here may serve as a basis for future efforts to numerically compute effective properties of heterogeneous media with multiple spatial scales

Sum-Frequency Generation Spectroscopy of Aqueous Interfaces: The Role of Depth and Its Impact on Spectral Interpretation

Vibrational sum-frequency generation (SFG) has become a dominant technique in the study of molecular interfaces owing to its capabilities for molecular recognition and specificity to anisotropic structure. Nevertheless, one crucial and influential aspect of the interfacial structure, namely, its inherent three-dimensional, depth-dependent nature, cannot be obtained through conventional SFG measurements. Furthermore, not only has this depth information been so far experimentally inaccessible through SFG, the simple existence of extended anisotropic depth also complicates the analysis and interpretation of any obtained spectra. In this Perspective, we analyze the role of depth-dependent structural anisotropy in second-order vibrational spectroscopy and explore various possibilities for how the desired depth information can be experimentally attained. Using aqueous interfaces as an important and widespread example system, we highlight the prevalence of such spatially extended depth profiles, demonstrate how signals from these regions can cause significant spectral distortions, and show the entanglement between experimental parameters with the overall nonlinear response. Finally, we evaluate recently developed measurement concepts that can yield depth information, emphasizing their particular strengths, and provide an outlook for future studies employing these methodologies for the vital elucidation of depth-dependent interfacial structure

Localization and Broadband Follow-Up of the Gravitational-Wave Transient GW150914

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser InterferometerGravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimatesof the time, significance, and sky location of the event were shared with 63 teams of observers covering radio,optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter wedescribe the low-latency analysis of the GW data and present the sky localization of the first observed compactbinary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-rayCoordinates Network circulars, giving an overview of the participating facilities, the GW sky localizationcoverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger,there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadbandcampaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broadcapabilities of the transient astronomy community and the observing strategies that have been developed to pursueneutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-upcampaign are being disseminated in papers by the individual teams

SeDeM Diagram: A New Expert System for the Formulation of Drugs in Solid Form

The SeDeM expert system is a methodology which is applied in preformulation and formulation studies of medicines specifically in solid dosage forms. This system informs on the physical profile of powdered substances (APIs and excipients) used to formulate drugs (Suñé et al, 2005; García et al, 2010; Aguilar et al, 2009). By determining whether powders (API or excipient) are suitable for direct compression, the SeDeM profile will inform about the advantages and gaps of those powdered substance to be used in direct compression, so the system informs on whether the direct compression method is appropriate (e.g.. wet granulation should be applied before compression). The characterization of powdered substances by SeDeM facilitates the identification of the characteristics that require amendment in order to obtain tablets by direct compression. This system thus provides information that will ensure the robust design of the formulation in the final product. This new method is based on the selection and application of several parameters that the formulation must fulfill to ensure a successful tablet elaborated by direct compression..

An Innovative Approach for The Integration of Proteomics and Metabolomics Data In Severe Septic Shock Patients Stratified for Mortality

In this work, we examined plasma metabolome, proteome and clinical features in patients with severe septic shock enrolled in the multicenter ALBIOS study. The objective was to identify changes in the levels of metabolites involved in septic shock progression and to integrate this information with the variation occurring in proteins and clinical data. Mass spectrometry-based targeted metabolomics and untargeted proteomics allowed us to quantify absolute metabolites concentration and relative proteins abundance. We computed the ratio D7/D1 to take into account their variation from day 1 (D1) to day 7 (D7) after shock diagnosis. Patients were divided into two groups according to 28-day mortality. Three different elastic net logistic regression models were built: one on metabolites only, one on metabolites and proteins and one to integrate metabolomics and proteomics data with clinical parameters. Linear discriminant analysis and Partial least squares Discriminant Analysis were also implemented. All the obtained models correctly classified the observations in the testing set. By looking at the variable importance (VIP) and the selected features, the integration of metabolomics with proteomics data showed the importance of circulating lipids and coagulation cascade in septic shock progression, thus capturing a further layer of biological information complementary to metabolomics information