Black Surface Research Articles

The Influence of Carbon Black Colloidal Properties on the Parameters of the Kraus Model.

The Payne Effect (also known as the Fletcher-Gent Effect) has a fundamental impact on the behavior of filled rubber composites and therefore must be considered during their design. This study investigates the influence of carbon black (CB) surface area and structure on the observed Payne Effect and builds on the existing models of Kraus and Ulmer to explain this phenomenon. Dynamic strain sweeps were carried out on natural rubber (NR) compounds containing eight different grades of CB at equivalent volume fractions. The loss and storage moduli were modeled according to the Kraus and Ulmer equations, using a curve optimization tool in SciPy. Subsequent regression analysis provided strong correlations between the fitting parameters and the CB structure and surface area. Using this regression analysis, this work provides further insight into the physical meaning behind the Kraus and Ulmer models, which are phenomenological in nature.

Morphological and Phylogenetic Analyses Reveal a New Species of Genus Monochaetia Belonging to the Family Sporocadaceae in Korea

The fungal strain belonging to the genus Monochaetia of the family Sporocadaceae was isolated from hairy long-horned toad beetle (Moechotypa diphysis) during the screening of microfungi associated with insects from Gangwon Province, Korea. The strain KNUF-6L2F produced white, light brown to dirty black surface, and olivaceous green colonies with the higher growth, while the closest strain M. ilicis KUMCC 15–0520T were light brown to brown, and M. schimae SAUCC 212201T light brown to brown toward center. The strain KNUF-6L2F produced shorter (5.7–14.0 μm) apical appendages than M. ilicis (6.0–24.0 μm), but similar to M. schimae (7.0–12.5 μm). Three median cells of KNUF-6L2F were light brown to olivaceous green, whereas brown and olivaceous cells were observed from M. ilicis and M. schimae, respectively. And the strain KNUF-6L2F produced larger conidiogenous cells than M. ilicis and M. schimae. Additionally, phylogenetic analyses based on molecular datasets of internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and β-tubulin (TUB2) genes corroborated the strain’s originality. Thus, the strain is different from other known Monochaetia species, according to molecular phylogeny and morophology, hence we suggested the new species Monochaetia mediana sp. nov. and provided a descriptive illustration.

Study on the Thermal Characteristics of Pavement Materials Using Polymer Binder (Polymer-Binder-Used Mixture)

Asphalt pavement accounts for ~87% of the overall pavement in Korea. However, owing to the black surface and extensive cover area, the ambient temperature rapidly increases, thereby contributing to the urban heat island effect. Therefore, pavement materials with modified porosity and pavement surface conditions have been developed; however, studies on the heat-related characteristic values of such pavement materials are insufficient. In this study, the thermal characteristics of pavement materials were evaluated with regard to the urban heat island effect. Test specimens such as WC-2 and PA-13, i.e., polymer-binder-used mixture, were compressed using a Gyratory Compactor. The thermal characteristics, i.e., thermal conductivity, specific heat capacity, thermal diffusivity, and thermal emissivity, were studied, and a heat accumulation test was performed. The water-permeable polyurethane concrete mixture (polymer-binder-used mixture) exhibited ~4% lower thermal emissivity than the conventional asphalt mixture, and according to the analysis of the change in thermal conductivity based on heat accumulation, it was confirmed that the rate of the heat energy transfer effect was ~20% slower than that of the asphalt mixture. The study results provide essential information for the analysis and design of energy harvesting and freeze-thaw pavement-related systems.

Coherent coupling between surface plasmons and localized surface plasmons in black phosphorus metamaterials

We propose a hybrid structure supporting electromagnetic coupling between black phosphorus surface plasmons (BPSP) mode and localized surface plasmons (BPLSP) mode theoretically. By dynamically controlling the carrier concentration of the black phosphorus strip, we show the coherent BPLSP-BPSP mode coupling. The coherent coupling can be described by using the coupled oscillator model, which shows a distinct Rabi splitting phenomena with frequency of 8.7 THz. The coherent coupling between BPLSP mode and BPSP mode also leads to the formation of multiple hybrid modes. In addition, we also explore the influence of structural parameters on coherent coupling. Our work may provide a reference for the interaction between different mode coupling.

Estimation of 137Cs Distribution and Recovery Using Various Types of Sorbents in the Black Sea Surface Layer

Monitoring 137Cs in seawater is necessary for the timely detection of radioactive contamination. The possibility of sorption and the sorption efficiency of 137Cs from seawater were studied for the first time during several cruises of the R/V (research vessel) Professor Vodyanitsky using various types of sorbents based on transition metal ferrocyanides (Anfezh, Niket, Uniket, FSS, FD-M, FIC, Termoxid 35, NKF-C) and zirconium phosphate (Termoxid 3A). The influence of the seawater flow rate and volume of the sorbent used for the recovery of 137Cs was estimated. The ferrocyanide sorbents Niket, Uniket, Termoxid 35, and FIC showed the best sorption efficiency (60–100%) at a seawater flow rate of 2–4 column volumes per minute. The data obtained during three cruises on the R/V Professor Vodyanitsky were analyzed. A detailed (28 sampling points) spatial distribution of 137Cs in the Black Sea along the southern coast of Crimea was studied using the sorbents that showed the best characteristics. An increase in 137Cs activity in the study area was not found, and the average activity was 9.01 ± 0.87 Bq/m3.

Building integrated photovoltaic powered wireless drone charging system

The future of urban drone-based transportation and delivery depends upon the efficient operation of its charging infrastructure. Working against gravity draws substantial energy from the drone’s battery, requiring frequent recharging. Currently, battery swapping is the most preferred method for drone charging. Charging multiple drones using the wired charging method has complications such as untangling, tripping over problems, wear and tear, and requires human intervention. This limits the drones from becoming fully autonomous and self-sufficient. To address these problems, an innovative Building Integrated Photovoltaic (BIPV) structure with wireless drone charging capabilities is designed to optimize the usage of rooftop space for multi-drone landings and utilize the wall space for efficient Photovoltaic (PV) based charging. This study compares the charging output from five PV panel mountings: a rooftop panel, a vertical PV panel, a 30° inclined PV panel, an inclined PV panel with a black reflective surface, and an inclined PV panel with a white reflective surface. The 30° inclined PV panel charges the 12.6 V/5.2 Ah drone’s LiPo battery in 31.29 min compared to vertically placed panels, which take 36.9 min. PV panel with a black reflective surface yields 10.09 % more energy compared to a white reflective surface PV panel. The output of the 30° inclined PV panel is connected to the wireless charging system, which transfers 120 W across a vertical displacement of 0–10 mm with an efficiency of 95.70 %.

Monitoring Black Sea environmental changes from space: New products for altimetry, ocean colour and salinity. Potentialities and requirements for a dedicated in-situ observing system

In this paper, satellite products developed during the Earth Observation for Science and Innovation in the Black Sea (EO4SIBS) ESA project are presented. Ocean colour, sea level anomaly and sea surface salinity datasets are produced for the last decade and validated with regional in-situ observations. New data processing is tested to appropriately tackle the Black Sea’s particular configuration and geophysical characteristics. For altimetry, the full rate (20Hz) altimeter measurements from Cryosat-2 and Sentinel-3A are processed to deliver a 5Hz along-track product. This product is combined with existing 1Hz product to produce gridded datasets for the sea level anomaly, mean dynamic topography, geostrophic currents. This new set of altimetry gridded products offers a better definition of the main Black Sea current, a more accurate reconstruction and characterization of eddies structure, in particular, in coastal areas, and improves the observable wavelength by a factor of 1.6. The EO4SIBS sea surface salinity from SMOS is the first satellite product for salinity in the Black Sea. Specific data treatments are applied to remedy the issue of land-sea and radio frequency interference contamination and to adapt the dielectric constant model to the low salinity and cold waters of the Black Sea. The quality of the SMOS products is assessed and shows a significant improvement from Level-2 to Level -3 and Level-4 products. Level-4 products accuracy is 0.4-0.6 psu, a comparable value to that in the Mediterranean Sea. On average SMOS sea surface salinity is lower than salinity measured by Argo floats, with a larger error in the eastern basin. The adequacy of SMOS SSS to reproduce the spatial characteristics of the Black Sea surface salinity and, in particular, plume patterns is analyzed. For ocean colour, chlorophyll-a, turbidity and suspended particulate materials are proposed using regional calibrated algorithms and satellite data provided by OLCI sensor onboard Sentinel-3 mission. The seasonal cycle of ocean colour products is described and a water classification scheme is proposed. The development of these three types of products has suffered from important in-situ data gaps that hinder a sound calibration of the algorithms and a proper assessment of the datasets quality. We propose recommendations for improving the in-situ observing system that will support the development of satellite products.

Two new species of Hymenochaetaceae from tropical Asia and America.

Two new species in Hymenochaetaceae, Fulvifomes acaciae and Pyrrhoderma nigra, are illustrated and described from tropical Asia and America based on morphology and phylogenetic analyses. F. acaciae is characterized by perennial, pileate, and woody hard basidiomata when fresh; ash gray to dark gray, encrusted, concentrically sulcate, and irregularly cracked pileal surface; circular pores of 7-8 per mm with entire dissepiments; a dimitic hyphal system in trama and context; absence of setal element and presence of cystidioles; and broadly ellipsoid, yellowish brown, thick-walled, and smooth basidiospores measuring 5-6 μm × 4-5 μm. P. nigra is characterized by perennial and resupinate basidiomata with dark gray to almost black pore surface when fresh; small and circular pores of 7-9 per mm, a monomitic hyphal system with generative hyphae simple septate, hyphoid setae dominant in subiculum but not in tube trama, and absence of cystidia; and ellipsoid, hyaline, thin-walled basidiospores measuring 4-5 μm × 3-3.6 μm. The differences between the new species and morphologically similar and phylogenetically related species are discussed. Keys to Fulvifomes and Pyrrhoderma have also been provided.

Physisporinus yunnanensis sp. nov. (Polyporales, Basidiomycota) from Southern China

A wood-inhabiting fungal species, Physisporinus yunnanensis is proposed based on a combination of morphological features and molecular evidence. Physisporinus yunnanensis is characterized by annual, resupinate, bone-hard basidiomata with an olivaceous to black pore surface, a monomitic hyphal system, presence of hyphoid cystidia at dissepiment edge and subglobose, smooth basidiospores measuring as 4–5.5 × 3.5–5 µm, and causing a white rot. The phylogenetic analyses based on molecular data of ITS+nLSU sequences showed that P. yunnanensis is sister to P. furcatus with high support (100% BS, 100% BP, 1.00 BPP). Both morphological characteristics and molecular phylogenetic analyses confirmed the placement of the new species in Physisporinus.

A modified kapok fiber based phase change composite for highly-efficient solar-thermal conversion

Phase change material (PCM) has attracted considerable attention as thermal energy management technology for thermal storage. However, the low thermal conductivity and poor solar-thermal conversion performance severely limit their further practical applications. Herein, we successfully design a novel form-stable polyethylene glycol (PEG)-kapok fiber (KF)@Ti3C2Tx nanosheets phase change composite with favorable thermal conductivity (0.630 W/mK) and outstanding solar-thermal conversion efficiency (98.49%). The Ti3C2Tx on KF could offer more thermally conductive channels, thus greatly improve the thermal conductivity of PEG PCM. The strong solar absorption of Ti3C2Tx and the black surface of the composite conjointly resulted in the highly efficient solar-thermal conversion procedure. When the as-prepared composite exposed to sunlight, the surface temperature could reach over 90 °C in just 10 min. This work could not only exhibit the great potential of PEG-KF@Ti3C2Tx in thermal energy management, but also provide a new and efficient way for high solar-thermal conversion.

Self-Sustained Programmable Hygroelectronic Interfaces for Humidity-Regulated Hierarchical Information Encryption and Display.

The emerging moisture-driven energy generation (MEG) technology opens up new possibilities for humidity-responsive materials, devices, and interdisciplinary opportunities in fields like information security. However, such potential remains untapped. Here, an original MEG structure with a hygroionic energy-conversion route by selective coating of ionic hygroscopic hydrogels on a carbon black surface is reported. The hygroionic route features a process in which the scavenged energy is stored in the electrical double layers formed at the interfaces between the ionic hydrogel and the carbon nanoparticles. The resultant electrical field developed across the hydrogel-coated wet carbon and the rest of the dry carbon area is thus durably lasted. Based on this unique structure, hygroelectronic information interfaces (HEII) for humidity-regulated information encryption and displayare put forward by devising hydrogel patterns on a carbon platform. Further by tuning the hygroscopicity of the ionic hydrogels and incorporating encoding methods (e.g., Morse code), it is demonstrated that the HEII platform is programmable to carry different information in certain humidity ranges. Unlike those conventional anti-counterfeiting methods that optically reveal the hidden information once the required stimulus is provided, the new HEII serves as a hierarchical solution for high-security encryption and display.

Adsorption of aromatic molecules on a black phosphorene surface: a first-principles study

The adsorption of several aromatic molecules on a black phosphorene surface was studied using density functional theory.

THE UTILITY OF METAGENOMIC DATA FOR THE BLACK SEA ECOLOGICAL STATUS ASSESSMENT

According to Marine Strategy Framework Directive the assessment of marine ecosystems’ environmental status is performed with 11 Descriptors, which are based on biological, physical and chemical parameters. The biological indexes are calculated based on taxonomic structure and distribution of eukaryotic communities. Meanwhile, bacterioplankton is sensitive to anthropogenic impact and is thus a promising indicator of aquatic environment status. We have tested the utility of ecological pressure index (Pi) calculated with chemical data and bacterial community-based index (microgAMBI) for the assessment of Black sea waters ecological status. According to our estimations Pi varied depending on the chemical data used for its calculation, which indicates the necessity of using a wide range of xenobiotics in complex ecological status assessment. MicrogAMBI indicated that the Black sea surface waters can be characterized by “good” environmental status. “Moderate”, “poor” and “bad” ecological status was shown for 3 stations, yet there were no significant region-specific differences between the shelf zone and the open water. Actinomycetales, Halomonadaceae and Shewanella relative abundance was associated with higher microgAMBI estimations and respectively with worse ecological status. Meanwhile, positive correlation was found between Synechococcus, Acidimicrobiaceae, Pelagibacteraceae, Rhodobacteraceae, Microbacteriaceae, Polaribacter, Rhodothermaceae and Chloroflexi abundance and “good” ecological status. Microbial metagenomic data is promising for the complex assessmnet of Black sea waters ecological status, however, more research is needed to validate this approach. The development of metagenomic databases will contribite to increase in precision of microgAMBI calculation and subsequent ecological status analysis.

Phylogenetic Analyses and Morphological Studies Reveal Four New Species of Phellodon (Bankeraceae, Thelephorales) from China.

Phellodon is a genus of ectomycorrhizal fungi with important ecological roles and exploitable biological activities. In this study, four new species of Phellodon, P. caesius, P. henanensis, P. concentricus and P. subgriseofuscus, are described from China based on morphological characters and molecular evidence. The phylogenetic analyses of Phellodon were carried out based on the ITS + nLSU gene regions and the combined sequence dataset of ITS + nLSU + nSSU + RPB1 + RPB2 gene regions. Phellodon caesius is characterized by its dark bluish-grey, dark grey to black grey pileus, ash grey to dark bluish-grey spines, and the presence of both simple septa and clamp connections on generative hyphae of stipe. Phellodon concentricus is characterized by its zonate pileal surface, dark grey context in pileus, and spongy basidiomata. Phellodon henanensis is characterized by its ash grey, light vinaceous grey to light brown pileal surface, thin context in pileus, and the presence of both simple septa and clamp connections on generative hyphae of spines. Phellodon subgriseofuscus is characterized by its fuscous to black pileal surface, white to light brown spines, and vinaceous grey context. Illustrated descriptions and the ecological habits of the novel species are provided.

Evaluating the Rheo-electric Performance of Aqueous Suspensions of Oxidized Carbon Black

HypothesisThe macroscopic properties of carbon black suspensions are primarily determined by the agglomerate microstructure built of primary aggregates. Conferring colloidal stability in aqueous carbon black suspensions should thus have a drastic impact on their viscosity and conductivity. ExperimentsCarbon black was treated with strong acids following a wet oxidation procedure. An analysis of the resulting particle surface chemistry and electrophoretic mobility was performed in evaluating colloidal stability. Changes in suspension microstructure due to oxidation were observed using small-angle X-ray scattering. Utilizing rheo-electric measurements, the evolution of the viscosity and conductivity of the carbon black suspensions as a function of shear rate and carbon content was thoroughly studied. FindingsThe carboxyl groups installed on the carbon black surface through oxidation increased the surface charge density and enhanced repulsive interactions. Electrostatic stability inhibited the formation of the large-scale agglomerates in favor of the stable primary aggregates in suspension. While shear thinning, suspension conductivities were found to be weakly dependent on the shear intensity regardless of the carbon content. Most importantly, aqueous carbon black suspensions formulated from electrostatically repulsive primary aggregates displayed a smaller rise in conductivity with carbon content compared to those formulated from attractive agglomerates.

Adsorption of 2,4-D and MCPA Herbicides on Carbon Black Modified with Hydrogen Peroxide and Aminopropyltriethoxysilane.

The carbon black N-220 surface was subjected to modification through H2O2 oxidation and deposition of aminopropyltriethoxysilane. The pristine (CB-NM) and modified materials (CB-Ox and CB-APTES) were characterized by N2 adsorption−desorption isotherms, scanning electron microscopy, energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetry, and FTIR spectroscopy. Carbon black samples were applied as adsorbents for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) herbicides from aqueous solutions. The influence of their surface properties on adsorption efficiency was analyzed and discussed. The results showed that the adsorption of the herbicides was pH-dependent, and the most favorable adsorption was observed in an acidic environment. The experimental data best fit pseudo-second-order and Langmuir models for kinetic and equilibrium data, respectively. The adsorption rate of both the herbicides increased in the order of CB-APTES < CB-Ox < CB-NM and was closely correlated with the mesopore volume of the carbon blacks. The monolayer adsorption capacities were found to be 0.138, 0.340, and 0.124 mmol/g for the adsorption of 2,4-D and 0.181, 0.348, and 0.139 mmol/g for the adsorption of MCPA on CB-NM, CB-APTES, and CB-Ox, respectively. The results showed that the surface chemistry of the adsorbent plays a more important role than its porous structure. Both herbicides were preferably adsorbed on APTES-modified carbon black and were adsorbed the worst on oxidized carbon black (CB-APTES > CB-NM > CB-Ox).

Characterizing formation mechanisms of secondary aerosols on black carbon in a megacity in South China

Refractory black carbon (rBC) aerosols emitted from incomplete combustion are important climate forcers. Understanding the chemical characteristics and evolution of rBC-related components is particularly crucial to assess rBC environmental impacts. Here, we explored the chemical components of rBC in Shenzhen, China, using a soot-particle aerosol mass spectrometer (SP-AMS). The observations showed that the rBC coating was mainly composed of secondary aerosols with an average mass contribution of 84.7 %. Among them, secondary organic coating occupied ∼57.7 % of the total coating mass. Exploration of the relationship between secondary organic aerosol (SOA) coating and Ox (=NO2 + O3, an indicator of the extent of photochemical processing) showed that SOA coating was generated mainly through photochemical oxidation during the day. Similarly, sulfate coating, with a small mass fraction of 0.9 %, was also dominated by photochemical oxidation. In contrast, nitrate coating responded positively to ambient relative humidity, especially at night, indicating that it was driven by heterogeneous reactions. In addition, the increased ratio of nitrate on rBC to bulk nitrate at night suggested that black carbon surface could facilitate nocturnal nitrate formation.

Blood-seeking horseflies prefer vessel-imitating temperature gradients on host-mimicking targets: Experimental corroboration of a new explanation of the visual unattractiveness of zebras to tabanids

Several hypotheses tried to explain the advantages of zebra stripes. According to the most recent explanation, since the borderlines of sunlit white and black stripes can hamper thermal vessel detection by blood-seeking female horseflies, striped host animals are unattractive to these parasites which prefer hosts with a homogeneous coat, on which the temperature gradients above blood vessels can be detected more easily. This hypothesis has been tested in a field experiment with horseflies walking on a grey barrel with thin black stripes which were slightly warmer than their grey surroundings in sunshine, while in shade both areas had practically the same temperature. To eliminate the multiple (optical and thermal) cues of this test target, we repeated this experiment with improved test surfaces: we attracted horseflies by water- or host-imitating homogeneous black test surfaces, beneath which a heatable wire ran. When heated, this invisible and mechanically impalpable wire imitated thermally the slightly warmer subsurface blood vessels, otherwise it was thermally imperceptible. We measured the times spent by landed and walking horseflies on the test surface parts with and without underlying heated or unheated wire. We found that walking female and male horseflies had no preference for any (wired or wireless) area of the water-imitating horizontal plane test surface on the ground, independent of the temperature (heated or unheated) of the underlying wire. These horseflies looked for water, rather than a host. On the other hand, in the case of host-imitating test surfaces, female horseflies preferred the thin surface regions above the wire only if it was heated and thus warmer than its surroundings. This behaviour can be explained exclusively with the higher temperature of the wire given the lack of other sensorial cues. Our results prove the thermal vessel recognition of female horseflies and support the idea that sunlit zebra stripes impede the thermal detection of a host‘s vessels by blood-seeking horseflies, the consequence of which is the visual (non-thermal) unattractiveness of zebras to horseflies.

Carbon black/electrolyte interface study by electromagnetic and electrochemical techniques in γAl2O3/poly(vinylidene fluoride)/carbon black composite materials: Application for lithium-ion batteries

This work aims at better understanding the interactions existing between the liquid electrolyte and the solid composite electrode in a Li-ion battery. We substituted the common active material (e.g. LiNi1/3Mn1/3Co1/3O2 or LiFePO4) by an insulating (inactive) γ-Al2O3 compound in order to detect and evidence the interaction between the carbon black electronic additive and the liquid electrolyte. Our study presents the characterization of charge (electrons and ions) transport at different scales by combining a high-frequency analysis performed by broadband dielectric spectroscopy (BDS, up to 1010 Hz), along with a low-frequency analysis performed by electrochemical impedance spectroscopy (EIS, down to 10−3 Hz). Two carbon black materials with two different specific surface areas (80 m2.g−1 and 65 m2.g−1, respectively) were studied. The electronic percolation threshold and the kinetics of impregnation of the hierarchical composite electrode by the liquid electrolyte have been determined with respect to the carbon black content. The significant influence of the adsorbtion of ions at the carbon black surface on the electrons transport is particularly highlighted and explained.

Potent and biostable inhibitors of the main protease of SARS-CoV-2

Potent and biostable inhibitors of the main protease (Mpro) of SARS-CoV-2 were designed and synthesized based on an active hit compound 5h (2). Our strategy was based not only on the introduction of fluorine atoms into the inhibitor molecule for an increase of binding affinity for the pocket of Mpro and cell membrane permeability but also on the replacement of the digestible amide bond by a surrogate structure to increase the biostability of the compounds. Compound 3 is highly potent and blocks SARS-CoV-2 infection invitro without a viral breakthrough. The derivatives, which contain a thioamide surrogate in the P2-P1 amide bond of these compounds (2 and 3), showed remarkably preferable pharmacokinetics in mice compared with the corresponding parent compounds. These data show that compounds 3 and its biostable derivative 4 are potential drugs for treating COVID-19 and that replacement of the digestible amide bond by its thioamide surrogate structure is an effective method.