Deep Pores Research Articles

Hexagonal Enhanced Porous GaN with Delayed Integrated Pulse Electrochemical (iPEC) Etching

This present study investigates the effect of time delay (Td) on the formation of porous GaN (P-GaN) using integrated pulse electrochemical (iPEC) etching. Porous GaN (P-GaN) was formed by etching an N-type GaN wafer with a 4% KOH electrolyte for 60 minutes under an ultraviolet (UV) lamp at a current density of 80 mA/cm2. A Td of 120 minutes was applied before electrochemically etching the P-GaN sample. The top view image of the field emission scanning electron microscopy (FESEM) revealed a significant difference when a Td was applied. A dense and uniform hexagonal P-GaN was obtained from the Td iPEC sample, while the non-Td sample exhibited a multi-layered hexagonal porous structure with unfinished pore-etched areas. Higher porosity and deeper pores were observed in the Td sample. Intense high-resolution X-ray diffraction (HR-XRD) peak intensity was observed in the Td iPEC sample with a lower full width half maximum (FWHM), indicating that the sample had better crystallinity. The Raman spectra of the sample anodized with a Td exhibited higher Raman peak intensity and a slight shift to a higher frequency concerning as-grown GaN, indicating better crystallinity and a tensile stress relaxation of 0.24 GPa. Post etching, a blue shift of the photoluminescence (PL) peak, from 364 nm (as-grown GaN) to 363 nm (P-GaN), was observed, and a small PL peak started to form around 385 nm compared to the as-grown GaN due to the relaxation of the tensile stress, which modified the bandgap. The PL peak intensity of the Td sample was higher than the non-Td sample, indicating that the porosity and uniformity allowed more light interaction with the material, resulting in more efficient photon absorption and emission. The results indicated that potentially efficient optoelectronics devices can be fabricated on a P-GaN using a combination of electroless and electrochemical etching of the GaN epitaxial layer.

Electrochemical analysis of Yttrium chromate nanoparticles synthesized via green mediated combustion route

Yttrium Chromate (YCrO4) nanoparticles (YCNPs) were synthesized using a solution combustion method with a green extract (NeemLeaves extract as a reducing agent. The as-obtained NPs are allowed for calcination at 600 °C. The PXRD pattern showed Bragg reflections confirming the formation of a pure tetragonal phase of YC NPs belonging to the space group I 41/a m d:1. without impurity peaks. The surface morphology revealed smaller, irregularly sized, and shaped NPs with pores and hollows which is the characteristic of solution combustion synthesis. UV–visible spectroscopic analysis confirmed the various absorbance peaks. The energy band gap, determined from Wood and Tauc's plot, was 3.08 eV. FTIR analysis confirmed the presence of specific functional groups in the sample. Electrochemical analysis revealed a specific capacitance range of 61.52 to 40.18 F/g within the scan range of 10 mV/s to 50 mV/s which is due to Increasing scan rate reduces specific capacitance by limiting ion diffusion into deeper pores, favoring interaction with the surface, thus decreasing utilization of active sites and overall capacitance. Collectively, these findings suggest that YCNPs hold promise for practical applications in advanced energy storage devices.

Pore Size Distribution and Fractal Characteristics of Deep Coal in the Daning-Jixian Block on the Eastern Margin of the Ordos Basin.

Important breakthroughs have recently been achieved in deep coalbed methane (CBM) exploration and development in regions such as the eastern margin of the Ordos Basin, China. Investigating the development characteristics of various-scale pores in deep coalbeds is of great significance for resource assessment and selection of favorable zones for CBM exploration. Herein, six deep coal samples were selected from the Shanxi and Taiyuan Formations in the Daning-Jixian block on the eastern margin of the Ordos Basin. Low-pressure CO2/N2 adsorption (LP-CO2/N2GA) and high-pressure mercury intrusion (HPMI) methods were employed to analyze pore volume, specific surface area, and pore size distribution, thereby evaluating the full-scale pore characteristics. Furthermore, the fractal dimension characteristics of deep coal rock pores were elucidated, revealing the influence of pore structure, burial depth, and coal composition. The results indicate that micropores in deep coal rocks have the highest volume and specific surface area proportions, while mesopores have the smallest volume proportion, and macropores make the least contribution to the total specific surface area. The V-S, Frenkel-Halsey-Hill, and Sierpinski models were suitable for calculating the fractal dimensions of micropores, mesopores, and macropores with LP-CO2GA, LP-N2GA, and HPMI experimental data, respectively. Other than the relatively smaller mesopore fractal dimension of samples 20-8 and 20-10, the micropore, mesopore, and macropore fractal dimensions successively increased in the other four samples. The comprehensive fractal dimension, which exhibited a decreasing trend with increasing pore volume and specific surface area, was negatively correlated with burial depth, mineral and moisture contents, and ash and volatile component yields, while it was positively correlated with vitrinite and fixed carbon contents.

Characterization and fractal characteristics of nano-scale pore structure in shale gas reservoirs: a case study of the deep Longmaxi Formation, Zigong region, Southern Sichuan Basin, China

Taking the Longmaxi deep-marine shale gas reservoir in Zigong region as the research target, this paper aimed to characterize the nano-scale pore structure and investigate the reservoirs’ heterogeneity based on fractal theory. By conducting a series of experimental studies, mainly including TOC, XRD, gas adsorption (N2 and CH4), we were able to clarify the main controlling factors for the heterogeneity of deep shale pore structure. Our results indicated that the deep marine shale possessed a significant amount of organic matter, as the average TOC value is 3.68%. The XRD analysis results show that quartz and clay were the main mineral types, and the total content of these two minerals averaged 77.5%. Positive correlations were observed between TOC and quartz, while TOC decreases as the clay mineral increases, this discovery indicating that quartz is biogenic. Based on FHH (Frenkele-Halseye-Hill) method, by using the LTNA adsorption isotherms, we took relative pressure P/P0=0.5 as the boundary, then two separate fractal dimension were deduced, D1 and D2 represent the fractal characteristics of small and large pores, respectively. Our study revealed that both D1 and D2 demonstrated positive correlations with N2 adsorption pore volume and adsorption specific surface area, while negatively correlated with the adsorption average pore diameter. Moreover, the two fractal dimensions showed positive associations with TOC and quartz and negative associations with clay. Additionally, D1 and D2 also demonstrated a positive correlation with Langmuir volume. The presence of micropores was found to significantly influence the formation of an irregular pore structure in shale. As the pore size decreased, the adsorption specific surface area increased, resulting in a more intricate pore structure, and the fractal dimension of the pores elevated, ultimately. This intricate structure is beneficial for the accumulation of shale gas. These research findings offer valuable insights for the comprehensive assessment of deep shale gas, and enrich our knowledge of enrichment mechanisms in deep shale gas reservoirs.

Full-Scale Pore and Microfracture Characterization of Deep Coal Reservoirs: A Case Study of the Benxi Formation Coal in the Daning–Jixian Block, China

The pore-fracture structure of deep coal reservoirs is highly important for evaluating, exploring, and developing coalbed methane (CBM) resources. This study considers three coal samples from the DJ57 well in the Benxi Formation in the Daning–Jixian block on the eastern margin of the Ordos Basin as the research object. Based on the coal quality parameters of the coal samples, field emission scanning electron microscopy (FE-SEM), gas adsorption experiments, high-pressure mercury intrusion porosimetry (MIP), and microcomputed tomography (micro-CT) scanning were used to quantitatively characterize the nanoscale pores and microscale fractures in deep coal reservoirs and to evaluate the pore-fracture structure at different scales. The results reveal that the pore types in the Benxi Formation coal samples are diverse and include mainly organic matter (OM) pores, inorganic pores (intraparticle and interparticle pores), and microfractures. The organic pores are diverse in shape and mainly exhibit round, oval, and wedge shapes, while the microfractures exhibit slender stripes or serrated curves. The multiscale quantitative characterization of deep coal reservoir pores and fractures is based on a variety of pore characterization methods, and the pore and fracture volume distributions are mainly U-shaped, revealing the coexistence of micropores and microfractures. The volumes of micropores (0.3–2 nm), mesopores (2–50 nm), macropores (50 nm to 10 μm), and microfractures (>10 μm) account for 78.00%, 6.78%, 2.08%, and 13.14%, respectively, of the total pore volume (PV). Based on a full-scale pore-fracture splicing calculation, the total permeability of the Benxi Formation coal samples ranges from 5.77 to 28.22 mD. The observation results indicate that the microfractures are connected to each other, forming a network structure with strong connectivity. The microfractures are mainly associated with pore diameters>100 μm, accounting for approximately 95% of the total permeability. Moreover, micropores in deep coal reservoirs provide a large space for CBM adsorption, and microfractures enhance the seepage capacity of CBM.

New insights into estimating the cementation exponent of the tight and deep carbonate pore systems via rigorous numerical strategies

One of the main constituents of any reservoir characterization is an accurate forecast of water saturation, which is highly dependent upon the cementation exponent. Even though there have been a lot of studies, the most common correlations depend on total porosity. This means that they do not work as well in heterogeneous carbonate reservoirs, especially tight formations with total porosities less than 10%. This study aims to develop accurate and universal models for estimating the cementation exponent in deep and tight carbonate pore systems located in West Asia. Two heuristic algorithms, including the radial basis function neural network optimized by ant colony optimization (RBFNN-ACO) and gene expression programming (GEP), were employed to calculate the cementation exponent. To do this, we prepared a databank incorporating cementation exponents, total porosity, and various pore types. Then, the databank is classified into the test subset (for model prediction checking) and the train subset (for model construction). The reliability of the new recommended models is inspected by applying several statistical quality measures associated with graphical analyses. So, the consequences of the modeling disclose the large precision of the above-mentioned RBFNN-ACO, GEP Model-I, and GEP Model-II by average absolute percentage relative deviations (AAPRD%) of 6.28%, 6.39%, and 7.45%, respectively. Based on the outliers analysis, nearly 95% of the databank and model estimations are, respectively, valid and reliable. Additionally, the three input variables, including moldic porosity (with a + 70% impact value), non-fabric-selective dissolution (connected) porosity (with a -30% impact value), and interparticle porosity (with a -23% impact value), exhibit the main affecting parameters on the cementation exponent. Comparing current results with traditional literature correlations demonstrates the supremacy of the RBFNN-ACO model (AAPRD = 6.28% and root mean squared error (RMSE) = 0.17) over the examined literature correlations such as Borai’s equation (AAPRD = 12.30% and RMSE = 0.41). In addition, RBFNN-ACO can give better results than Borai’s Eqn. for tight (porosity less than 10%) and deep carbonate samples.

Deep Sandstone Reservoir Characteristics and Pore Structure Classification Based on Fractal Theory: A Case Study of the Bayingobi Formation in Guaizihu Sag, Yin'e Basin.

The paper focuses on deep oil and gas resources in the Bayingobi Formation of Guaizihu Sag in the Yin'e Basin. Previous studies overlooked the differences between the pores and throats, mainly focusing on pore analysis. This work aims to analyze the pore structure and petrophysical properties of the reservoir using various methods. The study utilized the constant velocity mercury intrusion method to quantify pores and throats separately. Scanning electron microscopy and casting thin section techniques characterize the pore and throat morphology. The analysis compares the pore structures in reservoirs with different petrophysical properties. Additionally, pore and throat types are classified based on fractal dimensions, and factors influencing their development are discussed. Results reveal feldspar lithic sandstone as the predominant rock type with a low compositional maturity. The sandstone reservoirs exhibit low porosity (10.23%) and ultralow permeability (0.99 mD). Primary reservoir pore spaces include intergranular pores, dissolution pores, and microfractures. Pore radius averages at 195.32 μm, while throat radius is 3.76 μm. Pore structures are categorized as micropore small-throat, small-pore small-throat, and large-pore coarse-throat types. The study area generally exhibits a high pore-to-throat ratio, impacting reservoir petrophysical properties significantly. Pore development is primarily influenced by early diagenesis, organic acid dissolution, and hydrocarbon filling. Weak compaction and cementation transformations provide a material and spatial basis for the subsequent dissolution. The presence of thick organic-rich mudstone above and below the reservoir contributes to organic acid dissolution and hydrocarbon filling.

Deep learning-based pore network generation: Numerical insights into pore geometry effects on microstructural fluid flow behaviors of unconventional resources

Pore-scale transport behaviors and mechanisms of rock reservoirs are still not well understood to increase unconventional resource production. This work mainly focuses on proposing a deep learning-based method to rapidly construct optimal pore network with different pore types, and deeply analyze its effects on pore-scale transport behaviors and mechanisms. The pore-scale variables reservoir evaluation indexes are defined to quantitatively evaluate pore geometry effects on the properties and production of rock reservoirs. The two-phase displacement simulations in pore network are conducted to study microstructural flow behaviors and transport mechanisms. Results suggest that the deep learning-based digital labeling algorithm (DL-DLA) has excellent abilities to rapidly construct pore network with errors less than 5%, compared with the classical algorithms. Square pores and circle throats are suggested as the optimal pore network assembly, considering the fluid phase drainage efficiency and production rate. The microstructural transport mechanisms are concluded as the pore-throat drainage, pore-filling, fluid phase mixing and fluid phase equilibrium processes. The novel theoretical relation between fluid phase drainage and microscopic production indexes provides effective tools to estimate rock reservoir production with errors all less than 10%, which are helpful for the technique developments to increase the production of unconventional resources in rock reservoirs.

Hydrochemical Characteristics, Controlling Factors and Strontium Enrichment Sources of Groundwater in the Northwest Plain of Shandong Province, China

To elucidate the hydrochemical characteristics, controlling factors, sources and mechanisms of strontium ion enrichment in groundwater in the northwest plain of Shandong Province, China, 88 groundwater samples were collected, including 51 shallow pore groundwater samples, 29 deep pore groundwater samples and 8 karst groundwater samples. The hydrochemical characteristics of the different types of groundwater were quite different. The karst groundwater samples were all fresh water with a single hydrochemical type, either HCO3-Ca or HCO3-Ca·Mg. The deep pore groundwater samples were mainly brackish water, and the shallow pore groundwater samples were brackish water–salt water, which has complex hydrochemical types. The hydrochemical characteristics of all the types of groundwater were controlled by mineral dissolution and active positive cation exchange. In shallow pore groundwater, deep pore groundwater and karst groundwater, the dissolution of silicate, evaporite and carbonate minerals dominated the hydrogeochemical process. The strontium in groundwater was derived from the dissolution of minerals with strontium isomorphism. The average contents of strontium in shallow, deep and karst groundwater were 1.59 mg/L, 0.58 mg/L and 0.50 mg/L, respectively. The strontium in shallow pore groundwater was mainly derived from the enrichment of groundwater runoff, and its sources are abundant, with silicic rock being the main source. The deep pore groundwater mainly derived from the evaporative minerals containing strontium, and the karst water mainly derived from carbonate rock dissolution with similar characteristics.

On the localization and composition of BK channel pore gate: Selectivity filter vs. lipid occlusion of deep pore

On the localization and composition of BK channel pore gate: Selectivity filter vs. lipid occlusion of deep pore

Development of in-Situ Methods for Solution ALD

We have proposed and demonstrated a novel thin film deposition technique by transferring the principles of atomic layer deposition (ALD), known with gaseous precursors, towards precursors dissolved in a liquid.1,2 'Solution ALD'(sALD) shares the fundamental properties of standard ‘gas ALD’ (gALD), specially the self-limiting growth and the ability to coat conformally deep pores. It has been already shown that it is possible to transfer standard reactions from gALD to sALD such as oxides and sulfides deposition. However, sALD also offers novel opportunities such as overcoming the need for volatile and thermally robust precursors, offering the possibility to grow materials that cannot be obtained by gALD and using mild conditions which allow the growth on sensitive substrates. Recently we extended the understanding of the nucleation of selected materials grown by sALD such as CuSCN, TiO2 and SnSx. The study of the nucleation process relies on, first the identification of the absorbed chemical species at the surface by in-situ infra-red spectroscopy, second the ability to determine the type of interaction of the precursor with the surface by ex-situ solid state nuclear magnetic resonance (NMR) and third the evolution of nuclei formation with in-situ x-ray reflectometry (XRR) and atomic force microscopy. We developed the necessary instrumentation to obtain measurement compatible in liquid environment for each in-situ method. Form IR we can identify the phase preferential phase that is obtained as well as the defects formation for extremely thin films and NMR shows the chemical bonding of precursors at an early stage. Additionally, the AFM and XRR investigations are needed to follow the evolution of the nuclei size and their distribution of a surface as well as the nuclei density of each half cycle.The extension of the knowledge on the reaction mechanism in sALD process appears to be crucial to design next reactions and to understand later on the properties of the layers obtained with sALD. Wu, D. Döhler, M. Barr, E Oks,M. Wolf, L. Santinacci and J. Bachmann, Nano Lett. 2015, 15, 6379 Fichtner, Y. Wu, J. Hitzenberger, T. Drewello and J. Bachmann, ECS J. Solid State Sci. Technol. 2017,6, N171

Characterization of porous starch produced from edible canna (Canna edulis Kerr.) via enzymatic hydrolysis using thermostable α-amylase and glucoamylase

Porous starch (PS) with high surface areas can enhance functional properties, thereby expanding its application. The purpose of this study was to determine the effect of different types and concentrations of amylolytic enzymes on the physical, chemical, and functional characteristics of edible canna PS. Canna edulis Kerr. starch (5 g) was added with an enzyme (AM, GA or mixed) in a specific buffer, incubated at 60 °C for 8 h, then dried at 40 °C for 48 h. SEM displayed that AM, GA and mixed produced large & shallow, small & deep pores, and large & deep pores, respectively. Starch hydrolyzed by 75 U/g GA exhibited the highest swelling power and WAC (96.69 %). PS mixed had the highest solubility and MB adsorption capacity. The highest OAC of 111.21% was presented by the starch hydrolyzed by 100 U/g AM. PS could be applied as the encapsulation agents of nutrients or pigment carriers.

Study on the scale-forming mechanism of magnesium phosphate by polyepoxysuccinic acid based on solution conductivity method

PurposeThis study aims to investigate the influence of polyepoxysuccinic acid sodium (PESA), a green antiscalant, on the nucleation, crystallization and precipitation of magnesium phosphate.Design/methodology/approachThe conductivity method was used to investigate the maximum relative supersaturation of magnesium phosphate across various PESA dosages. Subsequently, a magnesium phosphate scale was prepared using the static scale inhibition method (GB/T16632-1996) and then analyzed via scanning electron microscopy.FindingsThe findings showed that PESA extends the induction period of magnesium phosphate crystallization, reduces crystal growth rate and elevates the solution’s relative supersaturation. Notably, PESA exerts a low dosage effect on inhibition of the magnesium phosphate scale, with the optimal dosage identified at 10 mL. Scanning electron microscopy revealed that PESA dispenses a dispersing effect on the magnesium phosphate scale, generating numerous concave, convex and deeper pores on the scale particles’ surface, and thereby significantly enhancing the surface area, especially when using an antiscalant with variable dosages.Originality/valueThis study sheds new light on the impact of PESA, a green antiscalant, on the crystallization and precipitation of magnesium phosphate, thus paving the way for the development of enhanced and eco-friendly scale inhibition strategies in future applications.

Deep pore grafting modification for PVDF membrane by supercritical carbon dioxide in combination with ultraviolet irradiation to improve permselectivity and oil/water separation performance

In order to enhance PVDF membrane’s permselectivity to oil and water during oil-water separation process, an efficient strategy that combining supercritical carbon dioxide technology (scCO2) and ultraviolet (UV) irradiation was proposed to change the wettability of PVDF membrane. The grafting of -COOH groups on PVDF membrane surface was demonstrated by FTIR-ATR, XPS and SEM. Deep pore grafting of acrylic acid in membrane pore interior was confirmed by establishing force models and corresponding wettability test. The results showed that permeate flux of deep pore modified membrane was 69.64Lm-2 h-1, which was 17.23% and 7.44% higher than that of unmodified membrane and surface modified membrane respectively. Interestingly, when reaction temperature not reached 40℃, some modified membranes were impermeable to water although they had good surface hydrophilicity, which was closely related to the critical point state of supercritical fluid mixture system.

Healing of keyhole porosity by means of defocused laser beam remelting: Operando observation by X-ray imaging and acoustic emission-based detection

One of the remaining challenges in Laser Powder Bed Fusion (LPBF) of metals is the control of the formation of keyhole pores, resulting from a local excessive energy input during processing. Such defects can lead to degraded mechanical properties and are typically detected and/or removed after the process through non-destructive quality-inspection procedures and porosity-removal treatments. Monitoring and controlling the formation of defects during the LPBF process can allow circumventing such time-consuming and costly post-process stages. This paper develops a new approach to perform in-situ healing of deep keyhole pores, using a positively defocused laser beam with finely tuned laser remelting process parameters. Synchrotron radiographic images of the process zone are acquired during laser remelting. The use of operando imaging enables the visualization of pore removal during processing, and unveils the effect of various remelting conditions on the healing efficiency. The acoustic signals generated during laser remelting are recorded using a high-sensitivity optical microphone, and analyzed in parallel with the X-ray images, allowing the acoustic signature of defect healing to be identified. The present paper demonstrates for the first time that an airborne acoustic sensor can be used to monitor the healing of keyhole pores during LPBF.

Spatial Distribution and Factors Influencing the Various Forms of Iron in Alluvial–Lacustrine Clayey Aquitard

The compression release of pore water in clayey aquitards has a significant impact on groundwater quality. Iron is an active variable element that mediates biochemical reactions in groundwater systems, but its transformation mechanisms in clayey aquitards remain unclear. The sediment and pore water samples from the shallow clayey aquitard (thickness = ~20 m) in the Chen Lake area of China were collected in three boreholes. The spatial distribution and influencing factors of Fe occurrence in the aquitard were revealed using hierarchical extraction, statistical analysis, and simulation calculations. The results indicate that the background value of alluvial–lacustrine sediments primarily affects the Fe concentration of clayey sediments. The dissimilatory reduction in free Fe oxide was the main source of Fe ions in pore water, resulting in a major percentage of Fe2+ in the total Fe concentration (0.07−5.91 mg/L). The abundant organic matter in organic-rich clay promoted a dissimilatory reduction in Fe (III) oxides, while the Fe concentrations of sediment and pore water were lower in the sand-rich stratum because of its weak adsorption capacity. The impact of human reclamation activities on the aquitard was mainly concentrated in the shallow layer (>−3 m), resulting in water drainage and O2 and CO2 input, which induced the crystallization of poorly crystalline Fe oxides. The input of reactive organic matter from reclaimed crops promoted the dissimilatory reduction in Fe oxides and the enrichment of Fe in deep pore water. The copious Fe2+ in deep stratum pore water tended to interact with CO32− and S2− to form coprecipitation with Fe (II). The concentrations of As, Cr, Sr, Zn, and Mn in pore water followed a similar variation trend to the Fe ion concentration, and their release could be attributed to the reduction dissolution of sediment Fe (III) oxides.

Adsorption behavior of serum proteins on anodized titanium is driven by surface nanomorphology.

Protein adsorption behavior can play a critical role in defining the outcome of a material by affecting the subsequent in vivo response to it. To date, the effect of surface properties on protein adsorption behavior has been mainly focused on surface chemistry, but research on the effect of nanoscale surface topography remains limited. In this study, the adsorption behavior of human serum albumin, immunoglobulin G, and fibrinogen in terms of the adsorbed amount and conformational changes were investigated on bare and anodized titanium (Ti) samples (40 and 60 V applied voltages). While the surface chemistry, RMS surface roughness, and arithmetic surface roughness of the anodized samples were similar, they had distinctly different nanomorphologies identified by atomic force microscopy and scanning electron microscopy, and the surface statistical parameters, surface skewness Ssk and kurtosis Sku. The Feret pore size distribution was more uniform on the 60 V sample, and surface nanostructures were more symmetrical with higher peaks and deeper pores. On the other hand, the 40 V sample surface presented a nonuniform pore size distribution and asymmetrical surface nanostructures with lower peaks and shallower pores. The amount of surface-adsorbed protein increased on the sample surfaces in the order of Ti < 40 V < 60 V with the predominant factor affecting the amount of surface-adsorbed protein being the increased surface area attained by pore formation. The secondary structure of all adsorbed proteins deviated from that of their native counterparts. While comparing the secondary structure components of proteins on anodized surfaces, it was observed that all three proteins retained more of their secondary structure composition on the surface with more uniform and symmetrical nanofeatures than the surface having asymmetrical nanostructures. Our results suggest that the nanomorphology of the peaks and outer walls of the nanotubes can significantly influence the conformation of adsorbed serum proteins, even for surfaces having similar roughness values.

Importance of nanorobots in pharma and medical field

Machines built at the molecular level (referred to as "nanomachines") may be utilized to treat the human body of its numerous diseases. Nanorobotics is the science of building machines or robots at or near the scale of a nanometre (10-9 meters). Nanomedicine is the term used to describe this application of nanotechnology to the field of medicine. Future-looking uses for nanotechnology include minuscule robots that can build other machines, navigate inside the body to distribute drugs, or do microsurgery. Chemists are discovering how to use protein dynamics to power micro and nano size machines using catalytic processes, drawing inspiration from the biological motors of live cells. The toolkit for nanorobots includes items like a cavity for storing medication, probes, blades, and chisels to remove plaque and obstructions, microwave emitters, and ultrasonic signal generators to destroy cancerous cells, two electrodes generating an electric current, heating the cell up until it dies, powerful lasers could burn away harmful material like arterial plaque. A cream incorporating nanorobots that remove the proper amount of dead skin, remove excess oils, add missing oils, apply the right amounts of natural moisturizing ingredients, and even accomplish the elusive objective of "deep pore cleaning" may be utilized to treat skin problems. Other uses include the treatment of gout, kidney stones, gouty arthritis, parasite elimination, cancer treatment, and arteriosclerosis treatment.

Construction of N-doped mesoporous carbon via micelle-induced chitosan for enhancing capacitive storage

Poor rate performance of traditional porous carbon originating from slow ion transport in deep and tortuous pore structures seriously limits its practical application in the field of capacitive storage. In this regard, a novel N-doped mesoporous carbon with excellent rate performance is fabricated through micellar induced chitosan self-assembly, followed by carbonization and activation. The resultant N-doped porous carbon exhibits high specific surface area of 1130 m2 g−1 and interconnected mesoporous structure, which offers short electron and ion transfer pathways improved wettability, and meanwhile provides sufficient interfacial active sites, and enhanced capacity of ion adsorption. These unique advantages endow the prepared porous carbon with a superior capacitance of 287 F g−1 at 1 A g−1 as well as an outstanding rate performance of 189 F g−1 at 10 A g−1 under 10 mg cm−2 in aqueous supercapacitor. Impressively, the assembled Zn-ion hybrid capacitor device achieves an energy density of 121.95 Wh kg−1 at 900 W kg−1 and maintains 65.25 Wh kg−1 at 18000 W kg−1. Meanwhile, this device also achieves excellent cycle stability. This research provides a cost-effective strategy for the construction of carbon-based materials in high-rate energy storage.

Ecosystem recovery after the Early Jurassic T-OAE in the Châabet El Attaris section of the Tunisian Atlas

The flooding of the Pliensbachian shelf of the North-South Axis of Central Tunisia during the early Toarcian favoured the development of organic-rich facies in the most subsiding areas, such as that represented by the Châabet El Attaris section. The lower Toarcian strata in this section is represented by organic matter-rich sediments (dark laminated marls with low carbonate content) and the negative carbon isotope excursion (CIE) of the Jenkyns Event. The relatively high TOC values, increase of redox sensitive elements, and the absence of benthic organisms confirm the adverse conditions for life at the sea floor (suboxic to anoxic conditions) during the polymorphum Biozone and lower part of the levisoni Biozone. This indicates that the Jenkyns Event is expressed in this setting as the so-called Toarcian Oceanic Anoxic Event (T-OAE). The diversity and abundance of the calcareous nannoplankton was very low during the early Toarcian.After the T-OAE, the decrease in TOC and the low values of the geochemical redox proxies indicate a re‑oxygenation of the bottom waters, parallel with an increase of the carbonate content of the facies. After the negative CIE, the record of benthic macroinvertebrates (such as brachiopods, bivalves, ophiuroids and echinoids) and trace fossils (Zoophycos, Thalassinoides, Planolites, Chondrites, and locally Trichichnus) confirms the re‑oxygenation of the sea floor with increased diversity and abundance from the upper levisoni Biozone and bifrons Biozone. Benthic foraminifera colonization of the sea floor is evidenced by assemblages dominated by infaunal taxa, specially opportunist forms, such as Lenticulina, and progressive increase of diversity and abundance that confirms oxic pore-waters from the levisoni-bifrons biozone boundary. Planktic organisms attest to a progressive recovery of environmental conditions in the photic zone with increasing diversity and abundance of calcareous nannoplankton and radiolarians from the uppermost part of the levisoni Biozone and the bifrons Biozone. A first pulse after the negative CIE is represented by placoliths of the genus Lotharingius (shallow dweller) interpreted as a renewed input of nutrients to surface waters. The subsequent dominance of muroliths, especially of Crepidolithus crassus (a deep dweller), suggests a successive restoration of the deep-photic zone communities. These observations point towards enhanced oxygen availability in deep waters and pore waters due to improved basin ventilation.Taphonomic features of foraminifera pointing to dissolution in the bifrons Biozone are related to a lowered pH below the redox boundary within the sediment. In the same way, the presence of ferruginous moulds of microfossils (gastropods, bivalves, brachiopods, foraminifera, sponge spicules and radiolarians) with framboidal texture, actually preserved as goethite but originally pyrite, confirm the presence of reducing conditions within the sediment below the redox boundary. The record of Trichichnus confirms the reducing conditions in the deepest infaunal environments during the bifrons Biozone and is consistent with the development of pyrite moulds of microfossils early in the diagenesis.