Surface Structural Features Research Articles

Enhanced Flexibility of the Segmented Honey Bee Tongue with Hydrophobic Tongue Hairs.

Fibrous surfaces in nature have already exhibited excellent functions that are normally ascribed to the synergistic effects of special structures and material properties. The honey bee tongue, foraging liquid food in nature, has a unique segmented surface covered with dense hairs. Since honey bees are capable of using their tongue to adapt to possibly the broadest range of feeding environments to exploit every possible source of liquids, the surface properties of the tongue, especially the covering hairs, would likely represent an evolutionary optimization. In this paper, we show that their tongue hairs are stiff and hydrophobic, the latter of which is highly unexpected as the structure is designed for liquid capturing. We found that such hydrophobicity can prevent those stiff hairs from being adhered to the soft tongue surface, which could significantly enhance the deformability of the tongue when honey bees feed at various surfaces and promote their adaptability to different environments. These findings bridge the relationship between surface wettability and structural characteristics, which may shed new light on designing flexible microstructured fiber systems to transport viscous liquids.

An integrated approach to detect the structural setting of South Dyiur area, Central Western Desert, Egypt, via potential field data

The South Diyur exploration block of nearly 38,000 sq. km is located in the Farafra Oasis region in Egypt’s Western Desert. The North West-South East (NW-SE) trend is the regional structural surface features in the South Diyur District. The Bouguer gravity and magnetic data have been analyzed to provide new information about the tectonic setting and subsurface structures of the study area. The advanced filtering techniques were used to map structural as well as varying depths of the study area. The total intensity aeromagnetic map was first corrected by the application of the reduction to the pole technique (RTP). Then, the fast Fourier transform is applied on the gravity and magnetic maps to show the regional and residual sources and their depths, using the radial averaged power spectrum curve which divided into two segments; according to the slope, the maximum depth is 4,000 m that probably reflects the deep sources at this place. And the shallow sources (near-surface geological structures) showed depth of 600 m. The structure of the basement that influences the sedimentary cover thickness and the region’s hydrocarbon potentiality is interpreted as uplifts and basins resulted from parallel fault groups. It is found that there are strike slip faults trending NW-SE, regional faults divided the area into many blocks forming grabbens “Misawage graben and Dirrut basin” and horsts “Bahariya-Cairo uplift,” and the residual faults have many trends but the general trend from the rose diagram is west north west-east south east.

Kinetics of Interfacial Ion Transfer in Lithium-Ion Batteries: Mechanism Understanding and Improvement Strategies.

The development of high-rate lithium-ion batteries is required for automobile applications. To this end, internal resistances must be reduced, among which Li+ transfer resistance at electrode/electrolyte interfaces is known to be the largest. Hence, it is of urgent significance to understand the mechanism and kinetics of the interfacial Li+ transfer. This Spotlight on Applications presents recent progress in the analysis and mechanical understanding of interfacial Li+ transfer. First, we review the reported activation energies (Ea) at various solid/liquid interfaces. On this basis, the mechanism and rate-determining step of the interfacial Li+ transfer are discussed from the viewpoints of the desolvation of Li+, the nature of the solid electrolyte interphase (SEI), and the surface structural features of electrodes. After that, we introduce promising strategies to reduce the Ea, highlighting some specific cases that give remarkably low Ea. We also note the variations in frequency factors or pre-exponential factors (A) of the interfacial Li+ transfer, which are primarily dominated by the number of Li+ intercalation sites on electrode surfaces. The current understanding and improvement strategies of interfacial Li+ transfer kinetics presented herein will be a foundation for designing high-rate lithium-ion batteries.

Soil-ecological regional assignment of Middle Volga region forest-steppe zone

Middle Volga region has a variety of natural resources. In the modern world, the primary task is the competent and reasonable resources consumption. For more complete and rational use of territory natural resource potential, we will consider such important significant factors as relief, soils, agriculture, as well as erosion processes manifestation in their territories. On the territory of Middle Volga region, the main large uplands and low plains, as well as the large rivers valleys and lakes hollows, formed as a result of tectonic uplifts and earth’s crust submergence, experienced a different history. Here, the peculiarities of the geological structure, the different nature and intensity of tectonic movements, which determined different heights amplitudes, affected. In addition to erosion, other exogenous processes participated in their relief appearance formation: winding, sliding, soil leaching, subsidence, etc. As a result, surface structure features of Middle Volga region relief forms have developed.

The role of surface and electronic structure features of the CsTeMoO6 β-pyrochlore compound during the photooxidation dyes process

The surface features of CsTeMoO6 with β-pyrochlore structure have been investigated during adsorption and photocatalytic oxidation of methylene dye under visible light irradiation. The apparent quantum yields are 5.12•10−6 and 3.57•10−6 molecules/photons for MB and MO conversion. The refinement of the CsTeMoO6 electronic structure has been carried out by both transmittance and reflectance spectroscopy. The impurity defect absorbance bands in the visible light region have been found out into the wide band gap. Superoxide radicals have been detected as the main active radical species for oxidation, whereas hydroxyl radicals are not formed because of specific holes reaction. Features of surface interactions with cationic and anionic dyes have been studied. The abnormal high absorption capacity of methylene blue by CsTeMoO6 has been obtained. Cs atoms play important role for cationic dye oxidation, while anionic dye predominantly adsorbs and decomposes on the Te/Mo-atom surface centers. The phase stability and composition of catalyst powder have been confirmed by X-ray powder diffraction analysis and X-ray microanalysis. The surface composition and features have been investigated using X-ray photoelectron spectroscopy.

Synthesis of a castor oil-based quaternary ammonium surfactant and its application in the modification of attapulgite

Abstract Castor oil-based quaternary ammonium surfactant (COQA) was synthesized by an ester-exchange reaction of refined castor oil (CO) (raw material) with N,N-dimethyl ethanol amine followed by quaternization with epichlorohydrin (ECH). Its surface activity and structural features were determined. The critical micelle concentration (CMC) of the surfactant at 25 °C was 1.79 × 10−3 mol/L. The surface tension of an aqueous COQA solution at CMC was 38.19 mN/m. Subsequently, the synthesized COQA was used to modify attapulgite (ATP) by binding it to the surface of ATP. The change in the morphology of the modified-ATP (M-ATP) was attributed to the presence of the COQA bound to the surface of the rod-shaped crystals, although the crystal structure of the silicate did not change. Compared to ATP, the microstructure of the M-ATP was less rigid.

Soil Surface Micro-Topography by Structure-from-Motion Photogrammetry for Monitoring Density and Erosion Dynamics

Soil erosion is a major threat to soil fertility, food security and water resources. Besides a quantitative assessment of soil loss, the dynamics of erosion-affected arable soil surfaces still poses challenges regarding field methods and predictions because of scale-dependent and soil management-related complex soil-crop-atmosphere processes. The objective was to test a photogrammetric Structure-from-Motion (SfM) technique for the mm-scale mapping of the soil surface micro-topography that allows the monitoring without special equipment and with widely available cameras. The test was carried out in May 2018 on three plots of 1.5 m2 (upper-, middle-, and footslope) covering surface structural features (tractor wheel lane, seed rows) along a Maize-cultivated hillslope with a coarse-textured topsoil and a runoff monitoring station. The changes in mm-scaled surface micro-topography were derived from repeatedly photographed images of the same surface area during a 2-weeks period with two rain events. A freely available SfM-program (VisualSfM) and the QGIS software were used to generate 3D-models of the surface topography. Soil cores (100 cm3) were sampled to gravimetrically determine the topsoil bulk density. The micro-topographical changes resulting from rainfall–induced soil mass redistribution within the plots were determined from the differences in SfM maps before and after rain. The largest decrease in mean soil surface elevation and roughness was observed after rain for the middle slope plot and primarily in initially less compacted regions. The spatially-distributed intra-plot changes in soil mass at the mm-scale derived from the digital micro-topography models indicated that local depressions were filled with sediments from surrounding knolls during rainfall. The estimated mass loss determined with the SfM technique decreased, if core sample-based soil settlement was considered. The effect of changes in the soil bulk density could be described after calibration also with an empirical model suggested in the Root-Zone-Water-Quality-Model. Uncertainties in the presented plot-scale SfM-technique were due to geo-referencing and the numerical limitations in the freely available SfM-software. The photogrammetric technique provided valuable information on soil surface structure parameters such as surface roughness. The successful application of SfM with widely available cameras and freely available software might stimulate the monitoring of erosion in regions with limited accessibility.

Formation of Multiphase Soft Metal from Compositing GaInSn and BiInSn Alloy Systems

Emerging functional room-temperature liquid metals generally include gallium-based and bismuth-based alloys. Their excellent electrical conductivity, thermal conductivity, flexibility, fluidity, and reflectivity can enable their application in many fields. However, there are quite a few problems that need to be solved before their application. For example, liquid metals are often difficult to adhere and diffuse on solid substrates due to their high surface tension and fluidity, which hinders the application and promotion. Herein, we report a method to develop multiphase soft metals from gallium- and bismuth-based alloys. Particularly, room-temperature multiphase soft metals of GaBiInSn alloys developed from Ga67In20.5Sn12.5 and Bi33.1In51.3Sn15.6 alloys via compositing, mixing, and heating treatment are first reported, which include the solid phase, liquid phase, and paste phase, respectively. The free metal alloy grains are dispersed in GaBiInSn alloys and transition constantly among different phases. More importantly, the structure, size, density, and other characteristics of free metal alloy grains can be modified by adjusting the mass ratio of each component. The surface morphology, structure, wettability, adhesion, work function, and photoelectric characteristics of multiphase soft metals can be controlled and optimized by controlling phase transition. As a result, the wettability of the obtained Ga50.25Bi8.28In28.2Sn13.27 is obviously improved (the contact angle decreased from 118.5° to 94°), with a high work function (4.75 eV), high reflectivity (78.14%), low electrical resistivity (2.94 × 10–7 Ω m). Meanwhile, several typical applications of the multiphase materials were demonstrated. The results of this work will offer a promising strategy to directly prepare liquid metal flexible electrodes on PI, PET, and silk, and also, the stability can be kept well under large deformation and curling conditions.

Utilization of metal or non-metal-based functional materials as efficient composites in cancer therapies.

There has been great progress in cancer treatment through traditional approaches, even though some of them are still trapped in relative complications such as certain side effects and prospective chances of full recovery. As a conventional method, the immunotherapy approach is regarded as an effective approach to cure cancer. It is mainly promoted by immune checkpoint blocking and adoptive cell therapy, which can utilize the human immune system to attack tumor cells and make them necrose completely or stop proliferating cancer cells. Currently however, immunotherapy shows limited success due to the limitation of real applicable cases of targeted tumor environments and immune systems. Considering the urgent need to construct suitable strategies towards cancer therapy, metallic materials can be used as delivery systems for immunotherapeutic agents in the human body. Metallic materials exhibit a high degree of specificity, effectiveness, diagnostic ability, imaging ability and therapeutic effects with different biomolecules or polymers, which is an effective option for cancer treatment. In addition, these modified metallic materials contain immune-modulators, which can activate immune cells to regulate tumor microenvironments and enhance anti-cancer immunity. Additionally, they can be used as adjuvants with immunomodulatory activities, or as carriers for molecular transport to specific targets, which results in the loading of specific ligands to facilitate specific uptake. Here, we provide an overview of the different types of metallic materials used as efficient composites in cancer immunotherapy. We elaborate on the advancements using metallic materials with functional agents as effective composites in synergistic cancer treatment. Some nonmetallic functional composites also appear as a common phenomenon. Ascribed to the design of the composites themselves, the materials' surface structural characteristics are introduced as the drug-loading substrate. The physical and chemical properties of the functional materials emphasize that further research is required to fully characterize their mechanism, showing appropriate relevance for material toxicology and biomedical applications.

Analysis of Spectroscopic, Morphological Characterization and Interaction of Dye Molecules for the Surface Modification of TiB2 Nanoparticles

Nanoparticles of titanium diboride (TiB2) coated with a conductive polymer and subjected to an oxidizing agent was carried out in this research. TiB2 nanoparticles coated with polypyrrole (PPy) were studied using XRD and TEM techniques. Nitrogen adsorption and desorption properties of nanoparticles are covered with modified polypyrrole to understand better the surface zone, structural features, and pore geometries of the nanoparticles. The water‐based hazardous anionic Congo red (CR) dye was removed using polypyrrole‐coated titanium diboride (PPy@TiB2) nanoparticles. Numerous cutting‐edge experimental techniques, including FTIR, FE‐SEM, EDXS, and element mapping analysis, were used to confirm the CR color’s adhesion to the PPy@TiB2 nanoadsorbent study. While conducting batch experiments, coated TiB2 nanoadsorbents with polypyrrole enhanced the adsorption behaviour. One of the factors evaluated in the adsorption tests was pH; another was contact time, and a third was dose. At pH = 4, 98.75% of Congo red dye was detached using 60 mg of PPy‐coated TiB2 nanoadsorbent. Several sorption‐desorption cycles were performed on this nanoadsorbent to determine its reusability. An excellent adsorption capacity for water treatment is reported in PPy‐coated TiB2 nanoadsorbent.

Surface morphology and structural characteristics of rice husk, its biochar and vermicompost

Surface morphology and structural characteristics of rice husk, its biochar and vermicompost

Radioactive mineralization detection using remote sensing and airborne gamma-ray spectrometry at Wadi Al-Miyah area, Central Eastern Desert, Egypt

Band rationing, principal component analysis (PCA) and decorrelation stretch (DS) techniques of Landsat-8 with Sentinel-2 data successfully used in the discrimination of the lithological units and the surface structure features of Wadi Al-Miyah area in the Central Eastern Desert of Egypt. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were processed to identify the hydrothermal mineralized alteration zones related to the radioactive minerals. Airborne gamma-ray spectrometry (AGRS) has been used to determine the naturally occurring radioactive anomalous zones such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh) and to follow their spatial distribution in Wadi Al-Miyah area. The analysis of AGRS data revealed that, the study area owns a wide range of radioelement concentrations ranging from 15.5 to 98.4 μR/h, 5.9–37.1 ppm, 17.2–95.4 ppm, and 0.53%-10.29% of total count (TC), (eU), (eTh), and (K), respectively. The interpretation of the Radioelements Composite Image (RCI) successfully delineated the enrichment zones with radioelement concentrations within the alkali feldspar granite, biotite-muscovite schist, granodiorite and the hydrothermal alteration areas within the diorite of Gabal Al- Bakriyah. The results concluded that the integrated remote sensing and airborne AGRS data are promising in detecting the potential areas enriched with K, eU and eTh.

Spinning disc photoreactor based visible-light-driven Ag/Ag2O/TiO2 heterojunction photocatalyst film toward the degradation of amoxicillin

The presence of antibiotics in waste and drinking water is causing increasing concern around the world, thereby an advanced sustainable technology needs to be developed to eliminate the antibiotics from water resources. Hence, an efficient spinning disc photoreactor (SDPR) equipped with visible light-activated Ag/Ag2O/TiO2 heterostructure thin film photocatalyst was assessed for the degradation of amoxicillin (AMX) as a typical antibiotic. The surface morphology, optoelectronic and structural features of Ag/Ag2O/TiO2 heterojunction were characterized by TEM, BET, mott Schottky, FESEM, EDS, AFM, XRD, UV–Vis-DRS, and contact angle measurements. Results confirm that Ag and Ag2O have a significant effect on the photocharge carrier separation and transfer of the as-developed photocatalyst system. The operative variables including illumination time, rotational speed, solution flow rate, aeration rate, pH, and initial AMX concentration were optimized by CCD. The results displayed the maximum AMX photodegradation (97.91%) could be achieved at optimal conditions involving illumination time of 80 min, a rotational speed of 225 rpm, the solution flow rate of 0.6 L/min, aeration rate of 20 L/min, pH = 6, and initial AMX concentration of 20 mg/L. Interestingly, more than 79% COD and 64% TOC were removed under optimum conditions during 80 min illumination time, respectively. Active species tests confirmed the dominant role of ·OH and ·O2− in AMX degradation. finally, the XRD pattern confirmed that the reusability assessments of the heterojunction film could successfully retain its stability for six consecutive photocatalytic degradation runs. This work demonstrates the feasibility of utilizing visible-light-driven thin-film photocatalysts in spinning disc photoreactors in treating the tenacious antibiotic pollutants.

ZIF-8-based oxygen reduction reaction catalyst prepared from one-pot and stepwise ion- and liquid-assisted grinding modified with tris-1,10-phenanthroline iron (II) perchlorate

In this study, a one-pot ion- and liquid-assisted grinding (ILAG) synthesis of ZIF-8-based catalysts was proposed and compared with a conventional stepwise synthesis to determine an appropriate method for proton exchange membrane fuel cells (PEMFCs). The performance characteristics of one-pot- and stepwise-synthesis catalysts were measured by various physicochemical and electrochemical characterization methods. In lab-scale production, the material cost of the one-pot-synthesis catalyst was seven times lower than that of the stepwise-synthesis catalyst. The surface structural characteristics of the one-pot- and stepwise-synthesis catalysts were identical, and the two catalysts showed similar onset potentials that were close to that of a Pt/C. However, based on PEMFC tests, the maximum power density of the one-pot-synthesis catalyst was lower than that of the stepwise-synthesis catalyst owing to the smaller micropore area of one-pot-synthesis catalyst. Nonetheless, the difference between maximum power densities was only 9.6% despite the large disparity in the material cost. Thus, the proposed one-pot-synthesis catalyst can be recommended as a promising non-platinum group metal (PGM) catalyst, but further research to improve its micropore area and performance is required.

Impact of Pre-Patterned Structures on Features of Laser-Induced Periodic Surface Structures.

The efficiency of light coupling to surface plasmon polariton (SPP) represents a very important issue in plasmonics and laser fabrication of topographies in various solids. To illustrate the role of pre-patterned surfaces and impact of laser polarisation in the excitation of electromagnetic modes and periodic pattern formation, Nickel surfaces are irradiated with femtosecond laser pulses of polarisation perpendicular or parallel to the orientation of the pre-pattern ridges. Experimental results indicate that for polarisation parallel to the ridges, laser induced periodic surface structures (LIPSS) are formed perpendicularly to the pre-pattern with a frequency that is independent of the distance between the ridges and periodicities close to the wavelength of the excited SPP. By contrast, for polarisation perpendicular to the pre-pattern, the periodicities of the LIPSS are closely correlated to the distance between the ridges for pre-pattern distance larger than the laser wavelength. The experimental observations are interpreted through a multi-scale physical model in which the impact of the interference of the electromagnetic modes is revealed.

Conical third harmonic generation from volume nanogratings induced by filamentation of femtosecond pulses in transparent bulk materials

We report on observations of conical third harmonic emission that emerges during supercontinuum generation produced by self-focusing and filamentation of high (20-200 kHz) repetition rate 180 fs, 1035 nm pulses from an amplified Yb:KGW laser in various nonlinear crystals and glasses: YAG, sapphire, YLF, LiF, CaF2, MgF2, LiSAF, fused silica and BK-7 glass. We show that conical third harmonic generation is a phase-matched four-wave mixing process, where noncollinear phase matching is achieved by means of reciprocal lattice vector, inversely proportional to the period of nanograting, which is inscribed by femtosecond filament in the volume of nonlinear material. The existence of a particular period required to phase match conical third harmonic generation was indirectly verified by investigations of periodicity features of high and low spatial frequency laser-induced periodic surface structures, in which matter is reorganized in a similar fashion.

SWCNTs/phthalocyanine polymer composite derived nitrogen self-doped graphene-like carbon for high-performance supercapacitors electrodes

Advanced carbon with great surface properties and structural features has been regarded as the valuable electrodes materials of high-performance supercapacitors. Herein, the SWCNTs/phthalocyanine polymer composite derived self-nitrogen-doped graphene-like porous carbon (SPCM) are synthesized via a simple solution blending and mechanical stirring. Because of the π-π interaction between metal-free phthalocyanine polymer and SWCNTs at the interface, the phthalocyanine polymer grows along the framework of the SWCNTs, resulting in the phthalocyanine polymer is pyrolyzed to form a graphene -like layered structure. In addition, the phthalocyanine polymer has the intrinsic characteristics of nitrogen-rich, thus the SPCM obtained pyridinic-N, pyrrolic-N, and graphitic-N functional groups derived from self-nitrogen-doping, which contribute to the increased electronic conductivity and surface electrochemically active sites of SPCM. Finally, the SPCM as electrode show an ultrahigh specific capacitance of 228 F g−1 at 1 A g−1 and excellent stability (retaining 93% of the capacitance after 2000 cycles).

Lanthanum-loaded peanut shell biochar prepared via one-step pyrolysis method for phosphorus removal and immobilization

ABSTRACT Phosphorus (P) is a nutrient element triggering eutrophication. Therefore, the removal of excess phosphorus has become an emergent demand. In this study, lanthanum-loaded biochar (La-BC) was prepared via a simple one-step pyrolysis method. Its surface properties and structural characteristics were analyzed by SEM, XRD, FTIR and pHpzc. The phosphate removal by the La-BC was systematically investigated in batch mode. Results showed that the phosphorus adsorption obeyed the pseudo-second-order model and Langmuir isotherm. The calculated maximum adsorption capacities were 31.94, 33.06 and 33.98 mg/g at 25, 35 and 45°C, respectively. Except for SO4 2− and CO3 2−, phosphate adsorption by the La-BC showed strong anti-interference to coexisting ions. For real water samples, the phosphate concentrations in the effluents were below 0.02 mg/L after treatment. The P loaded the La-BC was difficult to be desorbed, suggesting that the La-BC was not only a P-capping agent but also a P-immobilizing agent. More interestingly, a large number of stable LaPO4 nanofibers were formed on the La-BC surface via the reaction between the dissolved phosphate anions and La(OH)3 loaded on the adsorbent. Their intertwining facilitated the formation of the floc, which was conducive to the solid–liquid separation. Hence, the developed La-BC can be used as a potential adsorbent for natural waterbody remediation.

Aeromagnetic and digital elevation model constraints on the structural framework of southern margin of the Middle Niger Basin, Nigeria

High resolution aeromagnetic anomaly and topographic data using enhancement filtering techniques have resulted in better understanding of the nature of structures at the margins of the Middle Niger Basin. Due to the lack of structural data, the gold deposits within the margins of the Middle Niger Basin were variably excavated, leading to land degradation. The newly-produced structural map highly constrained the mineralization, which makes the study area and its periphery safe for gold exploration. Structural map has been produced from the integration of derivative maps to assess the pattern of surface and subsurface structural features within the studied area. The structural map unravels structural features with major and minor structural trends, in addition to a prominent crustal partitioning, characterized by the Ifewara shear zone. These structural features correlate very well with known gold mineralized locations and also predict new zones for structurally controlled gold and associated mineralization. The structural patterns are directly related with tectonic episodes in the basement. In fact, the Ifewara shear zone appears more pronounced on the total gradient and 3-D Euler deconvolution maps, which reveal various lineaments within the shear zone. The topographic maps (digital elevation model) clearly shows the surface morphology of the region under study while the resulting shaded-relief map reveal the continuity of the deduced magnetic lineaments that coincide with the valleys of River Niger which exploits zones of weakness from the lineaments. The results suggest high sensitivity of fluvial network to deduced lineaments with possible significant implication for alluvial gold mineralization.

Impact of Compression Force on Mechanical, Textural, Release and Chewing Perception Properties of Compressible Medicated Chewing Gums.

Medicated chewing gums (MCGs) represent a beneficial platform for realizing drugs intended for dental prophylaxis and treatment. The present study aimed to investigate the impact of compression force on the mechanical, textural, release, and chewing perception characteristics of compressible MCGs with the combination of lysozyme hydrochloride (LH) and ascorbic acid (AsA). Four batches of MCGs were obtained on a laboratory single-punch tablet machine applying different forces, i.e., 5, 7, 10, and 15 kN, and evaluated by their geometrical parameters, mechanical resistance, surface and internal structure characteristics, texture profile, release behavior, and perception attributes during mastication. It was found that increasing compression force slightly affected resistance to crushing and friability of MCGs, but resulted in surface smoothing and formation of a thicker layer with highly compacted particle arrangement. According to the texture analysis, increasing compression force led to harder and more adhesive gums, indicating possible difficulties in chewing and, therefore, impairment of their consumer properties. Lower compression forces were also found to be preferable in terms of better drug release from the obtained chewing gums. The volunteers’ assessment showed that an increase of compression force led to significantly raising the initial hardness and crumbliness as well as to decreasing the rate of the integral gum mass formation during mastication, which may negatively affect perceptive sensations when using MCGs. Based on the results obtained, the optimal compressing force was selected to be 7 kN, which allows obtaining MCGs with good organoleptic, mechanical, textural, and release properties.