Low-intensity Emission Research Articles

Effects of light exposure on human ultra-weak photon emission: Preliminary findings for a pioneering control tool in cosmetics

Currently, the cosmetic industry is developing several treatments based on the use of lights with different wavelengths for anti-ageing strategies and facial rejuvenation. Some lights have been proven to be beneficial for our skincare, but their actual effects require an in-depth analysis.Ultra-weak photon emission (UPE) is a spontaneous, low intensity emission from all living systems produced as a consequence of metabolic reactions (e.g., oxidative metabolism, cell division, photosynthesis, or carcinogenesis). However, it can also be induced by several factors, such as light exposure, wounds, thermal shock, and other stress elements. Thus, measuring human biophotonic emission can open new horizons to explore the real benefits of light therapies, particularly regarding the direct relationship between light exposure and free radicals, such as reactive oxygen species (ROS), which are the main cause of UPE.In this study, the ultra-weak photon emission from a sample of ten human beings after exposure to different lights was studied using red and green lights (artificially produced by an RGB LED lamp) and natural light (directly received from the sun), aiming to assess the UPE changes when directly focusing these types of lights on the skin. Hence, this technique could be proposed as a pioneering control tool in cosmetics, principally with phototherapies.Our preliminary results showed that the UPE response after light stimulation differed when a person was exposed to artificial lights compared to sunlight. Besides, there were relevant variations between women and men that should be deeply examined in further investigations by increasing the number of participating subjects in this experience. Furthermore, it was serendipitously discovered that the presence of certain unusual elements in our body, such as using hyaluronic acid fillers and having white hair (natural or dyed), could change the UPE intensity of our skin.

Highly emissive pyrrolo[1,2-a]quinoxaline based narrow band fluorescent sensors for detection of nitroaromatics and their application in spot paper test

In the modern day, explosive detection is essential to public safety, and fluorescent small molecules have gained popularity for their quick and accurate detection. Herein, we present the design and synthesis of a series of pyrrolo[1,2-a]quinoxaline-based conjugated small organic fluorophores (PQ-Ph-OH, PQ-Ph-NMe, PQ-Ph-OMe, PQ-Ph-Me, and PQ-Ph-CN) as fluorescence-based sensors for explosive molecules. The sensor molecules were synthesized in good to excellent yields using a dehomologative functionalization strategy. They exhibited excellent photophysical characteristics, which was tunable based on the substituent on the phenyl linker at position 3. DFT studies showed that the pyrroloquinoxaline moiety could act as an on-demand electron donor or acceptor, depending on the phenyl substituent. The molecules also exhibited solid state emission due to twisted geometry around the CC single bond between the heterocyclic scaffold and the phenyl derivative. This resulted in low band intense emission for the synthesized molecules. In the presence of electron-deficient nitroaromatic explosives, all the fluorophores showed excellent fluorescence quenching. Detection limits in the range of 10−4 M were obtained for all the fluorophores. Stern-Volmer plots show high values of binding constants, indicating good interaction between the fluorophores and the explosive molecules. The mechanism of sensing was confirmed by UV-PL spectral overlap and fluorescence lifetime measurements, which suggest a static quenching based on the formation of a ground state complex. Owing to solid state emissions in some of the derivatives, the synthesized molecules were applied to paper strips for spot detection of explosive molecules.

The Impact of Industrial Added Value on Energy Consumption and Carbon Dioxide Emissions: A Case Study of China

China, as the world’s largest energy consumer, is faced with the growing pressure of carbon emission reduction. Promoting the sustainable transformation of the economy and society has become a major concern for all sectors of society. This paper assesses the potential impacts of industrial added value on energy consumption and carbon dioxide (CO2) emissions from 2010 to 2020 in China using a multi-objective, linear programming model. The results show that when the industrial energy consumption is 3695.17 Mtce and the industrial CO2 emission is 9364.16 Mt, the goal of energy saving and emission reduction can be achieved. This corresponds to an annual average growth rate limit of industrial added value of 7.8%. In addition, we find that when the annual average growth rate of industrial added value is greater than 9.9%, changes in the annual average growth rate of industrial added value have no impact on economic development. However, industrial energy consumption intensity and industrial carbon emission intensity decrease with the increase in the annual average growth rate of sub-sectors. This study proposes that energy conservation, emission reduction, and a realization of the sustainable transformation of industry scheme need to be achieved by the Chinese government in order to to continue to promote the development of several sectors with low industrial energy consumption intensity and low industrial carbon emission intensity through policy implications.

Stealth echolocation in aerial hawking bats reflects a substrate gleaning ancestry

Predator-prey co-evolution can escalate into an evolutionary arms race.1 Examples of insect countermeasures to bat echolocation are well-known,2 but presumptive direct counter strategies in bats to insect anti-bat tactics are rare. The emission of very low-intensity calls by the hawking Barbastella barbastellus to circumvent high-frequency moth hearing is the most convincing countermeasure known.2,3 However, we demonstrate that stealth echolocation did not evolve through a high-intensity aerial hawking ancestor becoming quiet as previously hypothesized2,3,4 but from a gleaning ancestor transitioning into an obligate aerial hawker. Our ancestral state reconstructions show that the Plecotini ancestor likely gleaned prey using low-intensity calls typical of gleaning bats and that this ability-and associated traits-was subsequently lost in the barbastelle lineage. Barbastelles did not, however, revert to the oral, high-intensity call emission that other hawking bats use but retained the low-intensity nasal emission of closely related gleaning plecotines despite an extremely limited echolocation range. We further show that barbastelles continue to emit low-intensity calls even under adverse noise conditions and do not broaden the echolocation beam during the terminal buzz, unlike other vespertilionids attacking airborne prey.5,6 Together, our results suggest that barbastelles' echolocation is subject to morphological constraints prohibiting higher call amplitudes and beam broadening in the terminal buzz. We suggest that an abundance of eared prey allowed the co-opting and maintenance of low-intensity, nasal echolocation in today's obligate hawking barbastelle and that this unique foraging behavior7 persists because barbastelles remain a rare, acoustically inconspicuous predator to eared moths. VIDEO ABSTRACT.

RadioAstron discovery of a mini-cocoon around the restarted parsec-scale jet in 3C 84

We present RadioAstron space-based very long baseline interferometry (VLBI) observations of the nearby radio galaxy 3C 84 (NGC 1275) at the centre of the Perseus cluster. The observations were carried out during a perigee passage of the Spektr-R spacecraft on September 21–22, 2013 and involved a global array of 24 ground radio telescopes observing at 5 GHz and 22 GHz, together with the Space Radio Telescope (SRT). Furthermore, the Very Long Baseline Array (VLBA) and the phased Very Large Array (VLA) observed the source quasi-simultaneously at 15 GHz and 43 GHz. Fringes between the ground array and the SRT were detected on baseline lengths up to 8.1 times the Earth’s diameter, providing unprecedented resolution for 3C 84 at these wavelengths. We note that the corresponding fringe spacing is 125 μas at 5 GHz and 27 μas at 22 GHz. Our space-VLBI images reveal a previously unseen sub-structure inside the compact ∼1 pc long jet that was ejected about ten years earlier. In the 5 GHz image, we detected, for the first time, low-intensity emission from a cocoon-like structure around the restarted jet. Our results suggest that the increased power of the young jet is inflating a bubble of hot plasma as it carves its way through the ambient medium of the central region of the galaxy. Here, we estimate the minimum energy stored in the mini-cocoon, along with its pressure, volume, expansion speed, and the ratio of heavy particles to relativistic electrons, as well as the density of the ambient medium. About half of the energy delivered by the jet is dumped into the mini-cocoon and the quasi-spherical shape of the bubble suggests that this energy may be transferred to a significantly larger volume of the interstellar medium than what would be accomplished by the well-collimated jet on its own. The pressure of the hot mini-cocoon also provides a natural explanation for the almost cylindrical jet profile seen in the 22 GHz RadioAstron image.

Spectral stacking of radio-interferometric data

Context. Mapping molecular line emission beyond the bright low-J CO transitions is still challenging in extragalactic studies, even with the latest generation of (sub-)millimetre interferometers, such as ALMA and NOEMA. Aims. We summarise and test a spectral stacking method that has been used in the literature to recover low-intensity molecular line emission, such as HCN(1−0), HCO+(1−0), and even fainter lines in external galaxies. The goal is to study the capabilities and limitations of the stacking technique when applied to imaged interferometric observations. Methods. The core idea of spectral stacking is to align spectra of the low S/N spectral lines to a known velocity field calculated from a higher S/N line expected to share the kinematics of the fainter line (e.g. CO(1−0) or 21 cm emission). Then these aligned spectra can be coherently averaged to produce potentially high S/N spectral stacks. Here we used imaged simulated interferometric and total power observations at different S/N levels, based on real CO observations. Results. For the combined interferometric and total power data, we find that the spectral stacking technique is capable of recovering the integrated intensities even at low S/N levels across most of the region where the high S/N prior is detected. However, when stacking interferometer-only data for low S/N emission, the stacks can miss up to 50% of the emission from the fainter line. Conclusions. A key result of this analysis is that the spectral stacking method is able to recover the true mean line intensities in low S/N cubes and to accurately measure the statistical significance of the recovered lines. To facilitate the application of this technique we provide a public Python package, called PYSTACKER.

Red-to-Near-Infrared Emitting PyrrolylBODIPY Dyes: Synthesis, Photophysical Properties and Bioimaging Application.

Near-infrared (NIR) fluorophores with characteristics such as deep tissue penetration, minimal damage to the biological samples, and low background interference, are highly sought-after materials for in vivo and deep-tissue fluorescence imaging. Herein, series of 3-pyrrolylBODIPY derivatives and 3,5-dipyrrolylBODIPY derivatives have been prepared by a facile regioselective nucleophilic aromatic substitution reaction (SN Ar) on 3,5-halogenated BODIPY derivatives (3,5-dibromo or 2,3,5,6-tetrachloroBODIPYs) with pyrroles. The installation of a pyrrolic unit onto the 3-position of the BODIPY chromophore leads to a dramatic red shift of both the absorption (up to 160 nm) and the emission (up to 260 nm) in these resultant 3-pyrrolylBODIPYs with respect to that of the BODIPY chromophore. Their further 5-positional functionalization provides a facile way to fine tune their photophysical properties, and these resulting dipyrrolylBODIPYs and functionalized pyrrolylBODIPYs show strong absorption in the deep red-to-NIR regions (595-684 nm) and intense NIR fluorescence emission (650-715 nm) in dichloromethane. To demonstrate the applicability of these functionalized pyrrolylBODIPYs as NIR fluorescent probes for cell imaging, pyrrolylBODIPY 6 a containing mitochondrion-targeting butyltriphenylphosphonium cationic species was also prepared. It selectively localized in mitochondria of HeLa cells, with low cytotoxicity and intense deep red fluorescence emission.

A tunable photo-electric co-excited point electron source: low-intensity excitation emission and structure-modulated spectrum-selection.

The development of a point electron source requires an efficient excitation mode with low energy consumption, flexible tunability, and high performance. In particular for traditional electron emission cathode materials, it is necessary to expand the function of this aspect to meet application demands in many emerging fields. In this study, we propose a photo-electric co-excited scheme to drive a tungsten (W) needle nano-cold-cathode. The developed W needle cathode has been demonstrated to show electron emission performance with a narrow energy spread of 0.76 eV and a high brightness of 4 × 109 A m-2 sr-1 V-1. This could be achieved through low-intensity co-excitation, including an electrostatic field below ∼0.5 V μm-1 and a laser intensity at ∼10 W cm-2 level. Based on this co-excitation, the electron emission further exhibited a tunable property relative to the intrinsic properties of the incident light, such as optical frequency and polarization, which is shown to be directly modulated by the structure of the W needle nano-cold-cathode. This work provides a choice to achieve tunable, miniaturized and integrated vacuum micro- and nano-electronic devices.

How Do Innovation-Driven Policies Help Sports Firms Sustain Growth? The Mediating Role of R&D Investment

The sports industry features low energy intensity and low emissions through which it has played an important role in realizing sustainable development. This study aims to examine the driving factors that help sports firms improve their innovation development and sustain growth. Using a panel of 95 sports firms listed on the New Third Board in China from 2015 to 2021 with 582 observations, this study evaluated the effect of innovation-driven policies on sports firms’ long-term growth, measured by market value, and the mediating effect of R&D investment on this relationship. The results showed that innovation subsidies and the deduction of R&D expenses can effectively encourage sports firms’ engagement in innovation development and finally help improve the firms’ market value. Furthermore, we found that the effect of R&D subsidies on sports firms’ market values increases with firm size. This study provides new insights into the literature on the long-term growth of sports firms by showing that policy support for sports firms’ innovation activities enables them to invest more resources into research and development activities, which finally reinforce their potential of long-term growth. Furthermore, the findings provide practical suggestions for policymakers on enhancing the development of the sports industry and helping sports firms sustain growth.

Novel “naked eye” chromofluorogenic azomethine imine chemosensors for the detection of F−, CN−, AcO− and H2PO4− anions

Novel “naked eye” chromofluorogenic chemosensors for biologically important anions F−, CN−, AcO− and H2PO4− based on 5-chloro-2-hydroxy- (1), 3,5-dichloro-2-hydroxy- (2) and 3-bromo-2-hydroxy-5-methoxybenzylidene (3) azomethine imines were synthesized. Their structure and sensing properties were studied using 1Н, COSY, 13С, HSQC, HMBC and 15N NMR, UV-Vis/fluorescence spectroscopy, X-ray diffraction analysis and DFT calculations. Compounds 1-3 exhibit low-intensity emission at 537–574 nm with an anomalous Stokes shift of 7830–8420 cm−1. In the presence of F−, CN−, AcO− and H2PO4− ions, this emission is completely quenched and a new intense fluorescence appears at 540–590 nm with values of the relative enhancement in fluorescence intensity (I/I0) 15-79 (F−) and 10-137 (CN−). Simultaneously “naked-eye” chromogenic effect is observed with a color change from pale yellow to intense yellow or orange. These spectral responses were attributed to the OH…An− bonding up to the deprotonation. The association constants found for fluoride anion are 5.5 × 108 M−2 (1), 1.3 × 103 M−1 (2) and 5.3 × 108 M−2 (3), and to cyanide anion - 2.8 × 103 M−1 (1), 2.0 × 103 M−1 (2) and 2.8 × 103 M−1 (3). UV-Vis limits of detection for the F− ion are 2.0–6.0 μM (1), and for the CN− ion – 1.0-2.0 μM.

Effect of inert ambient annealing on structural and defect characteristics of coaxial N-CNTs@ZnO nanotubes coated by atomic layer deposition

The structure and intrinsic defects of ZnO determine the photogeneration of electron-hole pairs. The control of these characteristics allows for improving the activity of photocatalytic nanostructures. The intrinsic defects of ZnO atomic layer deposited around carbon nanotubes, coaxial N-CNT@ZnO, and its evolution after annealing in a nitrogen atmosphere are studied. TEM showed that the coaxial N-CNT@ZnO structure is preserved up to 500 °C; some damage is seen at 600 and 700 °C. Raman and XPS reveal a low surface defect concentration for as-grown ZnO, increasing to a maximum for the 600 °C annealed sample. Cathodoluminescence shows a broad low-intensity green emission associated with oxygen vacancies of ZnO. The surface defects improved the photocatalytic degradation of amaranth dye, however, damage to the coaxial structure lowers the catalytic activity.

Syn-Eruptive Processes During the January–February 2019 Ash-Rich Emissions Cycle at Mt. Etna (Italy): Implications for Petrological Monitoring of Volcanic Ash

Low-intensity emission of volcanic ash represents the most frequent eruptive activity worldwide, spanning the whole range of magma compositions, from basalts to rhyolites. The associated ash component is typically characterized by heterogeneous texture and chemical composition, leading to misinterpretation of the role of syn-eruptive processes, such as cooling and degassing during magma ascent or even magma fragmentation. Despite their low intensity, the ash emission eruptions can be continuous for enough time to create problems to health and life networks of the communities all around the volcano. The lack of geophysical and/or geochemical precursor signals makes the petrological monitoring of the emitted ash the only instrument we have to understand the leading mechanisms and their evolution. Formation of low-level plumes related to ash-rich emissions has increasingly become a common eruptive scenario at Mt. Etna (Italy). In January–February 2019, an eruptive cycle of ash-rich emissions started. The onset of this activity was preceded on 24 December 2018 by a powerful Strombolian-like eruption from a fissure opened at the base of the New Southeast Crater. A lava flow from the same fissure and an ash-rich plume, 8–9 km high a.s.l., from the crater Bocca Nuova occurred concurrently. After about 4 weeks of intra-crater strombolian-like activity and strong vent degassing at summit craters, starting from 23 January 2019, at least four episodes of ash-rich emissions were recorded, mainly issued from the Northeast Crater. The episodes were spaced in time every 4–13 days, each lasting about 3–4 days, with the most intense phases of few hours. They formed weak plumes, up to 1 km high above the crater, that were rapidly dispersed toward different directions by dominant winds and recorded up to a distance of 30 km from the vent. By combining observations on the deposits with data on textural and chemical features of the ash components, we were able to discriminate between clasts originated from different crater sources and suggest an interpretive model for syn-eruptive processes and their evolution. Data indicate the occurrence of scarce (<10 vol.%) fresh juvenile material, including at least four groups of clasts with marked differences in microlite content and number density, and matrix glasses and minerals composition. Moreover, a large amount of non-juvenile clasts has been recognized, particularly abundant at the beginning of each episode. We propose that the low amount of juvenile ash results from episodic fast ascent of small magma batches from shallow reservoirs, traveling within a slow rising magma column subjected to cooling, degassing, and crystallization. The large number of non-juvenile clasts deriving from the thick crater infill of variably sealed or thermally altered material at the top of the magma column is suggested to contribute to the ash generation. The presence of a massive, granular crater infilling accumulating in the vent area may contribute to buffer the different geophysical signals associated with the active magma fragmentation process during the low-energy ash eruptions, as already evidenced at other volcanoes.

Ultra-wide bandgap β-Ga2O3 films: Optical, phonon, and temperature response properties

Optical and phonon interactions of Ga2O3 thin films with nanocrystalline morphology were studied at extreme temperatures. The films were grown using a sputtering technique and analyzed via temperature response transmission, Raman scattering, and high-resolution deep-UV photoluminescence (PL). Raman modes indicated that the structure corresponds to the β-phase. The optical-gap at the range of 77–620 K exhibited a redshift of ∼200 meV, with a temperature coefficient of ∼0.4 meV/K. The optical-gap at room-temperature is 4.85 eV. The electron–phonon interaction model at that temperature range pointed to a low energy phonon, ∼31 meV, that is involved in the thermal properties of the optical-gap. Detailed Urbach energy analysis indicated that defects are the dominant mechanism controlling the band-edge characteristics even at an elevated temperature regime where phonon dominance is usually expected. Defects are attributed to the disordered forms of graphite that were detected via Raman scattering and to the granular morphology of the film. A deep-UV laser with an above-bandgap exaction line of 5.1 eV was employed to map the PL of the films. The highly resolved spectra, even at room-temperature, show a strong emission of ∼3.56 eV attributed to self-trapped holes (STHs). The STH is discussed and modeled in terms of the self-trapped exciton. Moreover, a very distinct but low-intensity emission was found at 4.85 eV that agrees with the value of the optical-gap and is attributed to bandgap recombination. The intensity ratio between the STH and that of the bandgap was found to be 6:1.

Tailored TiO2 nanorod arrays for dye sensitized solar cell applications

A TiO2 layer using titanium (IV) butoxide on fluorine doped tin oxide (FTO) substrate is used as a seed layer for the growth of TiO2 nanorod arrays (TRA). TRAs with length of ∼1 to 2 μm were grown on seed layer (SL) by two step method. In the first step TiO2 SLs were deposited by sol-gel assisted spin coating method and the second step involved the typical hydrothermal technique to grow rutile TRAs. Most of the TRAs grown on FTO substrate without SL were randomly oriented and TRAs with 0.025 M SL was oriented vertically from the substrate. Whereas TRAs grown on 0.05 M SL showed hierarchical nanoflower clusters composed of a bunch of TRAs as petals blooming from the core. The XRD pattern showed all the three TRAs to be crystallized in a tetragonal rutile phase. Photo luminescence spectra revealed that the TRAs on 0.05 M SL have comparatively low intense blue emission band, predicting the suppressed electron-hole recombination rate. The power conversion efficiency of the dye sensitized solar cell (DSSC) with TRAs grown on 0.05 M SL was recorded as 3.18%, which is 3 times greater than that without SL and 1.6 times greater than that with 0.025M SL in our observations.

Anomalous Hα Emission Line Profile Detected at the Center of DDO 53

Abstract We present the detection of a very broad (FWHM = 670 ± 17 km s−1), low-intensity Hα emission line component near the center of DDO 53, a star-forming dwarf irregular galaxy located in the M81 group. The broad component is found at the base of a bright and narrow (FWHM = 38 ± 2 km s−1) component. Using WIYN/Sparsepak optical spectroscopy of the region in addition to multiwavelength archival data, we evaluate the plausibility of several candidate sources, and find that stellar winds from embedded young stars are the most likely origin. However, this result is surprising for such a faint H ii region.

Aerosol measurements with laser-induced breakdown spectroscopy and conditional analysis

The methodology referred as to Conditional Analysis for sampling of aerosols was first evaluated and verified, and then revisited to include the possible case where the analyte emission intensities are affected by low particle sampling rates, and low-intensity analyte emission lines are observed in the single-shot spectra. Calcium-bearing aerosol streams with a Ca mass concentration from 36.3 to 182.5 μg/m3 and 3.6 and 18.2 μg/m3 were generated and analyzed with a LIBS probe that employed a 28.3-mJ laser beam and sampled the aerosol flow at 5 Hz. Average relative errors of 16.0 and 18.4% were obtained for each concentration range with the use of Conditional Analysis. A modified version of Conditional Analysis was developed by involving the experimental particle sampling rates in an earlier stage of the overall calibration and analyte determination. With such approach a general reduction of the relative errors was obtained, and an average relative error of 10.7% was obtained for 4 test samples prepared independently. A minimum detectable mass of approximately 8 fg was calculated using the LIBS models of discrete particle sampling; and the Ca limit of detection was determined as 0.45 μg/m3 (0.3 ppb) based on calibration curves.

1-Oxo-1H-phenalene-2,3-dicarbonitrile Based Sensor for Selective Detection of Cyanide ions in Industrial Waste

A phenalenedicarbonitrile (1-oxo-1H-phenalene-2,3-dicarbonitrile) based probe 3 has been synthesized by following oxidative nucleophilic substitution of aromatic hydrogen reaction (SNArH) also called green reaction. Probe 3 is found to be selective towards detection of cyanide (CN−) ions even in the presence of other anions. It originally gives pink color in H2O-CH3CN (1:9, v/v) and is found to be non-emissive when observed under Ultraviolet (UV) lamp. Upon adding of CN− ions to solution of probe 3 (20 µM, H2O-CH3CN (1:9, v/v)) the pink color of probe 3 is bleached out and bright yellow emission is attained when observed under UV-lamp. The colorimetric changes are also accompanied by spectral changes. The absorption and low-intensity emission maximum of probe 3 have been observed at 527 nm and 567 nm, respectively but upon adding CN−, the absorption at 527 nm is quenched with formation of new band at 454 nm whereas enhancement in emission band at 567 nm is observed. Probe 3 shows strong binding for CN− ions and binding constant is calculated to be 1.1 × 104 M−1 through fluorescence titration profile and can detect CN− as low as 5.5 × 10−8 M. Binding mechanism of CN− with probe 3 is analyzed through infra-red spectroscopy and proton NMR titration, which reveals that CN− ions attack chemodosimetrically on -C=O of probe 3 to form cyanohydrin. Probe 3 is also used for detection of CN− in industrial waste water. The spectral changes of probe 3 in presence of a specific ion have been used to design a 1-to-2 decoder.

Improvement of Continuous Lateral Surface Mining Method for Coal Extraction from Closed Mines’ Pillars

The presented paper deals with a continuous lateral method of closed mines' coal pillars surface mining and its advantages in land intensity, dust emissions, maximizing coal extraction, and overburden transporting costs. While inclined and steep coal seam strata in the pillars are widely exploited with land-and-cost intensive deepening longitudinal mining method, this article substantiates the choice of modification of block-and-layer continuous lateral mining method for different kinds of coal deposits. The aim of the study is to specify the modifications of the method proposed, define the stages of their carrying out, and emphasize the advantages over deepening longitudinal method of coal pillars surface mining. The basic principle of the proposed continuous lateral method of mining the coal pillars is limiting the final depth of quarry by the vertical height of the first floor of the underground mine workings. The continuous lateral mining method is detailed in the article in three modifications (for development coal seams strata of high and medium thickness, as well as distanced separate coal seams), which advantages are low land intensity and dust emission from the dump. Attention is also paid to the economic benefits of the block-and-layer continuous lateral method of mining coal pillars of closed mines, whereby the overburden transporting costs can be significantly reduced, while limitations of the proposed mining method concern specific sites of closed mines that make up a small part of the coal pillars extracted by surface mining today.

Multi-Sensor Analysis of a Weak and Long-Lasting Volcanic Plume Emission

Volcanic emissions are a well-known hazard that can have serious impacts on local populations and aviation operations. Whereas several remote sensing observations detect high-intensity explosive eruptions, few studies focus on low intensity and long-lasting volcanic emissions. In this work, we have managed to fully characterize those events by analyzing the volcanic plume produced on the last day of the 2018 Christmas eruption at Mt. Etna, in Italy. We combined data from a visible calibrated camera, a multi-wavelength elastic/Raman Lidar system, from SEVIRI (EUMETSAT-MSG) and MODIS (NASA-Terra/Aqua) satellites and, for the first time, data from an automatic sun-photometer of the aerosol robotic network (AERONET). Results show that the volcanic plume height, ranging between 4.5 and 6 km at the source, decreased by about 0.5 km after 25 km. Moreover, the volcanic plume was detectable by the satellites up to a distance of about 400 km and contained very fine particles with a mean effective radius of about 7 µm. In some time intervals, volcanic ash mass concentration values were around the aviation safety thresholds of 2 × 10−3 g m−3. Of note, Lidar observations show two main stratifications of about 0.25 km, which were not observed at the volcanic source. The presence of the double stratification could have important implications on satellite retrievals, which usually consider only one plume layer. This work gives new details on the main features of volcanic plumes produced during low intensity and long-lasting volcanic plume emissions.

Effect of Low-Intensity Blue Light Emission on Physicochemical Properties of Blood Erythrocytes in Rats under Diabetes Mellitus Conditions

Abstract—The physicochemical characteristics of erythrocyte membranes from the peripheral whole blood of rats and the erythrocytes washed with physiological solution, using the method of acid hemolysis, under diabetes mellitus conditions and against the therapy based on low-intensity blue light emission in the visible light range have been studied. The use of low-intensity light therapy (LILT) led to a decrease in the resistance of erythrocyte membranes to the action of acid hemolytic in the control group animals. Under diabetes conditions, LILT prolonged total hemolysis and reduced the count of hemolysed erythrocytes relative to the indices in the group of animals with DM. No expressed hypoglycemic effect due to the LILT was observed in sick animals, and the content of glycolysed hemoglobin tended to decrease.