Thin Layer Research Articles

Effect of shape and thermal conductivity of microstructured capillary-porous coatings on heat transfer during evaporation and boiling in thin horizontal liquid layers

Investigation results on heat transfer during evaporation and boiling in thin horizontal liquid layers on 2D modulated capillary-porous coatings with a sinusoidal profile in a wide range of relative pressures and layer heights are presented in this paper. Coatings were made on a 3D laser printer using the technology of additive selective laser sintering (SLS). One coating was made of bronze with a modulation wavelength equal to the Laplace constant of the working fluid and two coatings were made of stainless steel and bronze with a doubled wavelength. The experimental data obtained on the coatings were compared with each other and with the values obtained by evaporation and boiling of n-dodecane on a smooth surface under the same conditions. It is shown that in the region of low relative pressures in liquid layers with a height less than the Laplace constant, heat transfer intensification achieved on a sample made of a material with low thermal conductivity (stainless steel) was five times higher as compared to a smooth surface. In the range of relative pressures, when nucleate boiling was observed in the layers, the temperature difference reached on the bronze coatings was approximately 3–4 times less than on a smooth surface. The temperature difference for the stainless steel coating changed little with an increase in the heat flux. In pre-crisis conditions, the temperature difference during boiling on the stainless steel coating was less than on the bronze coatings in the entire range of relative pressures and layer heights. The highest critical heat fluxes were obtained on a bronze coating with a modulation wavelength equal to the Laplace constant.

Combined effect of cathodic potential and calcareous deposits on hydrogen evolution and permeation in Q460 steel

Cathodic protection is widely employed to prevent the corrosion of steel in marine environments. However, an inappropriate cathodic potential may lead to the generation of hydrogen and consequently induce cracking. Therefore, this study investigates the relationships between cathodic deposition potential, calcareous deposits, hydrogen evolution, and hydrogen permeation. Combining scanning electron microscopy, Raman spectroscopy, coupled focused ion beam lithography, and energy dispersive X-ray spectroscopy, it is observed that all calcareous deposits formed in artificial seawater at the potential range of −1.0 to −1.3 VSCE have calcium-rich inner and magnesium-rich outer layers, respectively. The thickness and compactness of each layer of the double-layer deposits vary with the cathodic deposition potential. Combining potentiodynamic polarization, hydrogen permeation experiments, and the morphology of calcareous deposits, we can find that the deposits formed at the cathodic deposition potential of −1.1 VSCE exhibit a thin inner layer and a condensed outer layer, which is effective in balancing hydrogen recombination and absorption, thus, inhibiting hydrogen entry. This study provides guidelines for the cathodic protection of steel materials in marine environments.

Insights Into Janus Interfaces with Ordered Micro/Nanostructures for Low‐Temperature Differential Evaporation

AbstractLow‐temperature differential evaporation constitutes a promising direction for energy‐saving desalination. Herein, a novel Janus interfacial structure with well‐ordered micro/nanopores is developed. Fabricated Janus interfacial structure can weak the water intermolecular forces and pump water to the hydrophilic–hydrophobic junction. Within well‐ordered nanochannels, the increased curvature of the meniscus increases the ratio of thin water layers, thereby enhancing microscale heat transfer at the heated walls; in addition, the smaller nanopores limit the development of microscale vortices at the liquid–gas interface and prevent back mixing of intermediate water at the interface, which possess the nanoscale effect on intensifying the interfacial evaporation. These effects are validated by theoretical and experimental studies. Optimized Janus (20 nm)95°/25° structure exhibits evaporation fluxes up to 2.4 kg m−2 h−1 at 45 °C (feed side)/25 °C (permeate side, ambient pressure), as the theoretical evaporation enthalpy is only 30% of that for direct evaporation. The unique Janus structure simultaneously inhibits salt accumulation and achieve self‐cleaning, thereby maintaining steady performance during 480 h of continuous desalination and 50 cycles of batch operation. This work highlights a promising structural design strategy for separation materials with specific micro/nanoscopic topologies to achieve high performance thermally driven desalination applications.

Enhancing photovoltaic performance through interfacial Engineering: A comparative analysis of bismuth iodide (BiI3) and Cs2BiAgI6 as interlayer materials in the design of perovskite solar cells

In this study, solar cell capacitance simulator (SCAPS) was employed to investigate the impact of bismuth iodide (BiI3) and Cs2BiAgI6on the performance of perovskite solar cell. We analyze the influence of charge carrier mobility on perovskite,IL thickness and effect of series and shunt resistance on the behavior of the cell.Results show that adding a thin layer at the interface between the Perovskite active layer and HTL effectively improve hole extraction by defect passivation,which in turn improve device performance in comparison to a common reference design. Our findings reveal that the structure with Cs2BiAgI6 was more efficient where the optimum configuration was (PSi/CuO/Cs2BiAgI6/perovskite/ ZnO) with power conversion efficiency(PCE) of 19.82 %, Fill Factor (FF) of 68,04 %, open circuit voltage (Voc)of 1,438 V and, Short circuit current (Jsc) of 20,2519 mA. cm − 2. Levelized cost of electricity (LCOE) of PSCs was estimated using the compute unit costs, it was found to be 4.41 US cents / kWh with a lifetime of ten years,below then the cost of conventional PSC devices.

Development of a 2D Network of Zinc Organophosphate with an 8-Membered Ring Core Having Corrosion Resistance Properties.

A 2D framework, i.e., zinc organophosphate [Zn(tmbiph)(solv)]2 (tmbiphH4 = tetramethyl-[1,1'-biphenyl]-4,4'-diyl bis(dihydrogen phosphate); solv = 2H2O) with an eight-membered ring core has been developed. The hierarchical and rational design of the zinc organophosphate has been achieved by carefully designing an organic bisphosphate ligand with two phosphate monoester groups connected through extended aromatic rings with methyl groups at ortho positions. The development of the 2D network does not require any ancillary ligand due to participating two phosphate groups in the coordination. The molecular structure of the zinc phosphate material was determined using single-crystal X-ray diffraction technique. The corresponding Co and Cu organophosphate materials have also been obtained using the same synthetic method; however, these compounds could not be confirmed structurally due to nondiffractive crystal quality. The structure of zinc organophosphate obtained through single-crystal X-ray diffraction has also been supported by theoretical calculations using density function theory. Furthermore, the zinc organophosphate material has been employed as an corrosion inhibitor for mild steel. The effect of the zinc phosphate framework on mild steel in 1 M HCl was investigated using polarization and electrochemical impedance spectroscopy. This study suggests that such phosphate inhibitors can be employed in the form of a thin protective layer on the electrode surface.

Deflection and control of the mixing region in membraneless vanadium micro redox flow batteries: Modeling and experimental validation

Membraneless micro redox flow batteries operate within the laminar flow regime to mitigate the convective mixing between catholyte and anolyte. The absence of an ion-exchange membrane reduces manufacturing costs and overall cell resistance, thereby enhancing battery performance. However, it also poses a new challenge: the precise control of the thin mixing layer established between the two co-flowing electrolytes. Undesired displacements of the mixing region lead to increased crossover losses and significant liquid transfer between tanks. This work addresses the deflection of the mixing region under varying flow conditions, considering electrolyte viscosity variations due to the changes in the local state of charge arising during battery operation. This is achieved through a combination of mathematical analysis, numerical simulations, and experimental results. The conservation equations and non-dimensional parameters governing the problem are first written and discussed. The model is then integrated numerically incorporating different inlet and outlet boundary conditions to simulate the effect of various flow control strategies. Next, the numerical results are validated against experimental realizations of the flow. Finally, three case studies are presented and discussed. This work highlights the relevance of variable viscosity in the operation of co-laminar membraneless micro redox flow batteries, and proposes for the first time feasible control methods to mitigate undesired disturbances in the hydraulic circuit, thereby minimizing crossover losses.

Tissue-Specific Natural Synthesis of Galanthaminein Zephyranthes Species and Its Accumulation in Different In Vitro-Grown Organs Following Methyl Jasmonate Treatment

Galanthamine is an immensely valuable alkaloid exhibiting anti-cancer and antiviral activity. The cultivation of plant tissues in in vitro conditions is a good source for the synthesis and enrichment of secondary metabolites of commercial interest. In this study, the Amaryllidaceae alkaloid galanthamine was quantified in three Zephyranthes species, such as Zephyranthes candida, Zephyranthes grandiflora, and Zephyranthes citrina, and the impact of the methyl jasmonate (MJ) signaling molecule on galanthamine accumulation was monitored in in vitro-derived plant tissues. This is the first ever study of the MJ-regulated accumulation of galanthamine in in vitro-grown Zephyranthes tissues. Shoot regeneration was obtained in all three Zephyranthes species on Murashige and Skoog (MS) medium containing 2.0 mgL−1benzylaminopurine (BAP) + 0.5 mgL−1 naphthalene acetic acid (NAA). The regenerated shoots were rooted on a medium containing 2.0 mgL−1 indole butyric acid (IBA). A GC-MS study of Zephyranthes extracts revealed the presence of 34 phyto-compounds of varied levels with therapeutic activities against diseases. The galanthamine content was quantified in plant parts of the three Zephyranthes species using high-performance thin layer chromatography (HPTLC); the maximum was found in Z. candida bulb (2.41 µg g−1 dry wt.), followed by Z. grandiflora (2.13 µg g−1 dry wt.), and then Z. citrina (2.02 µg g−1 dry wt.). The galanthamine content showed bulb > leaf > root source order. The in vitro-generated plantlets were treated with different MJ concentrations, and the galanthamine yield was measured in bulb, leaf, and root tissues. The highest galanthamine content was recorded in bulbs of Z. candida (3.97 µg g−1 dry wt.) treated with 150 µM MJ, showing an increase of 64.73% compared to the control. This accumulation may be attributed to MJ-induced stress, highlighting the potential commercial synthesis of galanthamine in vitro.

Multi-wavelength and broadband plasmonic switching with V-shaped plasmonic nanostructures on a VO2 coated plasmonic substrate

In this paper, periodic arrays of identical V-shaped gold nanostructures and variable V-shaped gold nanostructures are designed on top of a gold-coated silicon dioxide (SiO2) substrate with a thin spacer layer of vanadium dioxide (VO2) to realize multi-wavelength and broadband plasmonic switches, respectively. The periodic array of identical V-shaped nanostructures (IVNSs) with small inter-particle separation leads to coupled interactions of the elementary plasmons of a V-shaped nanostructure (VNS), resulting in a hybridized plasmon response with two longitudinal plasmonic modes in the reflectance spectra of the proposed switches when the incident light is polarized in the x-direction. The x-direction is oriented along the axis that joins the V-junctions of all VNSs in one unit cell of the periodic array. On exposure to temperature, electric field, or optical stimulus, the VO2 layer transforms from its monoclinic semiconducting state to its rutile metallic state, leading to an overall change in the reflectance spectra obtained from the proposed nanostructures and resulting in an efficient multi-wavelength switching action. Finite difference time domain modelling is employed to demonstrate that an extinction ratio (ER) >12 dB at two wavelengths can be achieved by employing the proposed switches based on periodic arrays of IVNSs. Further, plasmonic switches based on variable V-shaped nanostructures—i.e. multiple VNSs with variable arm lengths in one unit cell of a periodic array—are proposed for broadband switching. In the broadband operation mode, we report an ER >5 dB over an operational wavelength range >1400 nm in the near-IR spectral range spanning over all optical communication bands, i.e. the O, E, S, C, L and U bands. Further, it is also demonstrated that the wavelength of operation for these switches can be tuned by varying the geometrical parameters of the proposed switches. These switches have the potential to be employed in communication networks where ultrasmall and ultrafast switches with multi-wavelength operation or switching over a wide operational bandwidth are inevitably required.

Ultrathin Carbon Textures Produced on Machined Surfaces in an Integrated Finishing Process Using Microabrasive Films

This study presents research into the unique method of depositing carbon layers onto processed surfaces, during finishing with abrasive films, on a global basis. The authors of this article are holders of the patent for this method. What makes this technology outstanding is that it integrates processes, whereby micro-finishing and the deposition of a carbon layer onto freshly exposed surface fragments is achieved simultaneously, in a single process. Among the main advantages accruable from this process is the reduction of surface irregularities, while the deposition of a carbon layer is achieved simultaneously. Ultrathin graphite layers can be widely used in conditions where other methods of reducing the coefficient of friction are not possible, such as in regard to micromechanisms. This article illustrates the application of carbon coating, end on, on a surface processed with abrasive film, containing intergranular spaces, saturated with graphite. Thin carbon layers were obtained on two substrates that did not contain carbon in their initial composition: soda–lime glass and a tin–bronze alloy. It was performed through microscopic examinations of the produced surface, roughness analyses of these surfaces, and analysis of the chemical compositions determined by two methods, namely EDS and GDOES, proving the existence of the coatings. The aim of this paper is to prove the possibility and efficiency of using graphite-impregnated lapping films in the deposition process of carbon films, with improved surface smoothness, durability, and wear resistance. The produced coatings will be tested in regard to their operational properties in further research. The authors underline the potential of this method to revolutionize surface treatment processes, due to the significant advantages it offers across various industries.

The use of amines as steel corrosion inhibitors in butanol-gasoline blends

Butanol is an interesting component used for blending gasoline fuels. However, the polar nature of butanol allows the solubility of water and ionic compounds in butanol-gasoline blends (BGBs) making them aggressive to mild steel. Amines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentaamine, morpholine, piperazine, and hexamethylenediamine, were tested as corrosion inhibitors for mild steel in BGBs. Additionally, the influence of the acetic acid and sodium chloride concentrations on the inhibition efficiency was examined. Electrochemical impedance spectroscopy andpotentiodynamic polarization were employed for the measurements, complemented by static immersion testing and an XPS surface analysis. The highest inhibition efficiency was demonstrated for diethylenetriamine, triethylenetetramine, andhexamethylenediamine, achieving a value of 95 % or more at aconcentration of 100 mg/L. The formation of ionic pairs involving protonated amines andchlorides was also confirmed. The XPS analysis revealed a very thin passive layer of iron oxides, which may form in the presence of amines, protecting mild steel in BGBs.

Millimeter wave negative refractive index metamaterial antenna array

In this paper, a novel negative refractive index metamaterial (NIM) is developed and characterized. The proposed metamaterial exhibits negative effective permittivity (εeffe) and negative effective permeability (µeffe) at millimeter wave frequency of 28 GHz. This attractive feature is utilized to enhance the gain of a microstrip patch antenna (MPA). Two thin layers of 5 × 5 subwavelength unit cell array of NIM are placed above a single MPA to enhance the gain of the antenna. Each unit cell has an area of 3.4 × 3.4 mm2. A gain increase of 7.9 dBi has been observed when using the proposed NIM as a superstrate. Furthermore, the NIM array is placed over a 2 × 2 array of MPAs with four ports to demonstrate versatility of the metamaterial. The total size of the 2 × 2 antenna array system with N-MTM is about 61.1 × 34 × 16mm3 (5.71λ × 3.18λ × 1.5λ, where λ is the free-space wavelength at 28 GHz). The measurement result indicate that the maximum gain of the antenna array is 13.5dBi. A gain enhancement of 7.55 dB in E-Plane and 7.25 dB in H-Plane at the resonant frequency of 28 GHz is obtained. The proposed antenna structure is suitable for 5G millimeter wave communications, in particular, for possible implementation in future millimeter wave access points and cellular base stations.

The evaluation of the antioxidant activity of selected Eryngium species based on thin-layer chromatography fingerprints using chemometric tools

The purpose of the study was to confirm the utility of multivariate technique to predict antioxidant activity of selected Eryngium extracts based on chromatographic data. Five Eryngium species were analyzed using Thin Layer Chromatography (TLC) with silica gel to obtain their fingerprints. The highest relative content of quercitrin (marker) was observed for E. giganteum. The chemical similarity between extracts was evaluated by Principal Component Analysis (PCA) and Hierachical Cluster Analysis (HCA), and the results confirm the similarity between the same three E. planum from various natural sites. The total phenolic content with Folin–Ciocalteu reagent and antioxidant activity with DPPH reagent by spectrophotometry were determined, and the highest content of phenolics (concentration of gallic acid, mg⋅mL−1) was obtained for E. campestre, E. amethystinum and E. planum T. The highest antioxidant activity (concentration of gallic acid and inhibition %) were obtained for E. planum T. and E. amethystinum, while the lowest was obtained for E. planum Dębówka. High value of correlation coefficient between TLC and spectrophotometric data using Partial Least Squares Regression (PLS) confirms the usefulness of statistical method for the predicting the biological activity. In conclusion, the chromatographic and chemometric methods were suitable for prediction of antioxidant activity.

23.81%-Efficiency Flexible Inverted Perovskite Solar Cells with Enhanced Stability and Flexibility via a Lewis Base Passivation.

Lewis base molecules bind the undercoordinated lead atoms at interfaces and grain boundaries, leading to the high efficiency and stability of flexible perovskite solar cells (PSCs). We demonstrated a highly efficient, stable, and flexible PSC via interface passivation using a Lewis base of tri(o-tolyl)phosphine (TTP). It not only induced an intimate interface contact and a complete deposition of the perovskite thin layers on hole transport layers (HTLs) but also led to a better perovskite with a raised crystallinity, fewer defects, and a better morphology, including fewer gullies, high uniformity, and low roughness. Furthermore, the TTP treatments induced a good alignment of energy levels among the perovskites, HTLs, and C60. The resultant flexible inverted PSCs exhibited a high power conversion efficiency (PCE) of 23.81%, which is one of the highest PCEs among these flexible inverted PSCs. Moreover, the optimized flexible PSCs exhibited high storage stability, superior operation stability, and enhanced mechanical flexibility. This study presents an effective method to substantially raise the PCE, stability, and mechanical flexibility of the flexible inverted perovskite photovoltaics.

PH controllably induced PPTA/PEMs composite nanofiltration membranes for long-term acid-resistant separation

In this study, we deposited polyelectrolyte multilayers (PEMs) on Poly (p-phenylene terephthamide) (PPTA) ultrafiltration (UF) substrates with strong polyelectrolytes (PEs): polystyrene sulfonic acid (PSS) and poly (diallyldimethylammonium chloride) (PDADMAC). The growth pattern of PEMs was shifted from linear to exponential by changing substrate potential, which was attributed to synergism and antagonism of dispersion of PEs on hydrophilic substrates and electrostatic interaction between PEs and substrates. Eventually, PEMs of layer-dominated and pore-dominated regimes were successfully obtained. We focused on the transition from the pore-dominated to the layer-dominated regime of PEMs. The PEMs nanofiltration (NF) membranes in this situation showed a better separation performance due to the together work of the interface and in-pore energy barriers. The retention rate of Na2SO4 and MgSO4 was 98 % and 91 %. The eosin Y retention rate was 99.9 % and only declined 2 % after 100 h. The hindered deposition of pore-dominated regimes led to denser and thinner layers, which achieved long-term acid resistance. It maintained a stable salt retention after 185 h cross-filtration of 0.1 M H2SO4 feed solution. The performance of PEMs NF membrane was improved from a new perspective, and excellent acid-resistant nanofiltration membranes were obtained, which are expected to be used to treat industrial acidic wastewater.

The Interaction and Lift-Off Forces of an Atomic Force Microscope Tip from Single Fibers Extracted from Protective Clothing Fabric.

The widespread use of engineered nanoparticles (ENPs) poses a potential health hazard to humans, especially to those involved in either nanoparticle manufacturing or the usage and assembly of a final product. In this study, we performed systematic force vs distance experiments (F(z)) using an atomic force microscope (AFM) on fibers commonly used in street clothing and protective laboratory clothing to better characterize the relevant interaction forces between engineered nanoparticles (ENPs) and the contacted fabric fibers. The intent of this study is to identify those factors that influence the interaction of ENPs with fabrics with an aim to improve the efficacy of protective clothing against ENP exposure and mitigate potential health risks. A ∼14 nm diameter AFM SiOx tip (with nanoscale radius of curvature) is considered as an effective oxide ENP. Features present (or absent) in a well-executed F(z) AFM experiment provide a fingerprint that distinguishes the relevant forces and interaction mechanisms in play. Measurements of F(z) as a function of relative humidity were also performed to assess the importance of thin surface water layers in binding nanometer-size oxide ENPs to a fabric fiber. The F(z) data indicate the dominant mechanism for adhesion of the oxide tip to the various fabric fibers (cotton, Tyvek (HD polyethylene), polypropylene, and polyester) can be attributed to a van der Waals interaction. The analysis provides no evidence for long-range electrostatic forces or capillary-induced adhesion of the AFM tip to the fibers studied.

Effects of Al2O3 Rear Interface Passivation on the Performance of Bifacial Kesterite‐Based Solar Cells with Fluorine‐Doped Tin Dioxide Back Contact

Herein, ultrathin Al2O3 is investigated as a rear interface passivation layer for kesterite solar cells with F:SnO2 (FTO) back contact for potential performance improvement. On the passivation layer, a thin Mo layer is deposited to improve the FTO's ohmicity. Further, NaF is evaporated on the copper zinc tin sulfide (CZTS) precursors to create openings at the passivation layer and achieve Na‐induced benefits in the absorber. The CZTS absorbers deposited directly on the Al2O3‐coated FTO peel off, while those with Mo interlayer do not. For pure sulfide kesterite devices, the Al2O3 layer reduces the short‐circuit current density (JSC), resulting in poor device efficiency. On the other hand, significantly higher JSC is realized for mixed sulfide and selenide kesterite devices with Al2O3 passivation layer, with the current density–voltage curve suggesting a reduced barrier height at the rear interface. As a result, the efficiency is improved from 1.5% for devices without Al2O3 to 4.6% for those with Al2O3. Likewise, improved external quantum efficiency response is observed in the devices with passivation layer for backside and frontside illumination. Therefore, contribution of Al2O3 passivation layer to the performance of kesterite‐based solar cells is evident from the results of this study.

New data and insights on the secondary glass workshop of Comacchio (Italy): MgO contents, steatite crucibles and alternatives to recycling

This study introduces a collection of 33 glass samples, encompassing production indicators (blocks, fluidity tests, drops, cuts and wastes) and finished products (mainly goblets and probably a lamp) dating to the second half of the 7th century, except for a single more recent specimen (12th-14th). Additionally, a fragment was taken from a crucible bearing a thin layer of glass inside it. This new collection complements the investigation of glass materials from the Comacchio workshop previously analysed by Bertini et al. (2020).Measurements were performed using scanning electron microscopy, electron microprobe, laser ablation inductively coupled plasma mass spectroscopy on all samples and Sr–Nd isotopic analyses on 5 blocks.The results showed how the entire collection can be classified as natron-based silica-soda-lime glass and that the high MgO contents frequently observed are due to contamination with the steatite crucible. Contextually, the hypothesis of using plant ash-based glass mixed with natron-based glass formulated in the previous literature seems to have run out, along with the use of plant ash-based glass itself, further weakened by the very low representativeness of this latter type of glass on the site.The technological investigation further elucidated that recycling may not singularly account for the Comacchio glass technology. Discernible correlations may suggest the introduction of different types of metals, indicating a specialised control over the production process. Notably, the preference for green–blue glass emerges as a distinctive hallmark, underscoring the deliberate pursuit of a specific aesthetic taste.Lastly, the provenance analysis showed that over three-quarters of production was based on semi-finished products from Egypt, while only the remaining quarter came from the Levantine coast.

New data and insights on the secondary glass workshop of Comacchio (Italy): MgO contents, steatite crucibles and alternatives to recycling

This study introduces a collection of 33 glass samples, encompassing production indicators (blocks, fluidity tests, drops, cuts and wastes) and finished products (mainly goblets and probably a lamp) dating to the second half of the 7th century, except for a single more recent specimen (12th-14th). Additionally, a fragment was taken from a crucible bearing a thin layer of glass inside it. This new collection complements the investigation of glass materials from the Comacchio workshop previously analysed by Bertini et al. (2020).Measurements were performed using scanning electron microscopy, electron microprobe, laser ablation inductively coupled plasma mass spectroscopy on all samples and Sr–Nd isotopic analyses on 5 blocks.The results showed how the entire collection can be classified as natron-based silica-soda-lime glass and that the high MgO contents frequently observed are due to contamination with the steatite crucible. Contextually, the hypothesis of using plant ash-based glass mixed with natron-based glass formulated in the previous literature seems to have run out, along with the use of plant ash-based glass itself, further weakened by the very low representativeness of this latter type of glass on the site.The technological investigation further elucidated that recycling may not singularly account for the Comacchio glass technology. Discernible correlations may suggest the introduction of different types of metals, indicating a specialised control over the production process. Notably, the preference for green–blue glass emerges as a distinctive hallmark, underscoring the deliberate pursuit of a specific aesthetic taste.Lastly, the provenance analysis showed that over three-quarters of production was based on semi-finished products from Egypt, while only the remaining quarter came from the Levantine coast.

Custom fabricated three-dimensional printed surgical guide for trephine bur in autogenous bone graft: A technique report.

This technique presents a workflow that designs the custom surgical guide to cover a trephine bur using simple slicer software and three-dimensional (3D) printing to perform the semilunar technique. This method in autogenous bone grafting surgery harvests a thin layer of cortical bone in the donor site with a trephine bur. Its biologically favorable, round shape can be used as a shell to reconstruct the ridge with a 3D contour acceptable for future implant placement. A 78-year-old female patient required vertical and horizontal bone grafting for future implant placement due to the infection caused by the vertically fractured root of a premolar. The patient's cone beam computed tomography (CBCT) file was translated into a standard tessellation language (STL) file, and recipient and donor site models were created. Simulated surgery was done using the software first to detect any possible complications during surgery. The trephine bur planned for use in surgery was measured in necessary dimensions, and the values were added to create a guide for surgery in slicer software. Then, it was 3D-printed with a stereolithography (SLA) printer. After testing the fit of the guide, it was further tested on a fused filament fabrication (FFF) printed donor site model to check if the desired shape and size of the plate were acquired after harvest. Then, the plates were used for model surgery on the recipient site model. After no issues from the previous steps, the final patient surgery was approved and completed with success. This technique utilizes the SLA printing method to create the custom surgical guide for a trephine bur without using commercially available products. Moreover, it could be tested on FFF 3D-printed anatomical models to ensure its validity. With this innovative technique, clinicians can efficiently perform a semilunar technique, facilitating the surgery and improving patient care.

A Study of the EH36 Surface Sediment Layer under Joint Protection from Seawater Electrolysis Antifouling and Impressed Current Cathode Protection (ICCP) in a Marine Environment

A joint protection device for seawater electrolysis antifouling and ICCP was constructed, and comparative experiments were conducted to study the composition of the EH36 surface deposition layer under joint protection in a marine environment. Surface morphology analysis, energy-dispersive spectroscopy (EDS) imaging analysis, and X-ray diffraction (XRD) composition analysis were performed on the surface deposition layers of the experimental samples. The experimental results showed that under joint protection, a sedimentary layer was rapidly formed on the surface of EH36 to isolate the seawater medium, and this layer was mainly composed of Mg(OH)2 and a small amount of CaCO3. There was no corrosion on the surface of the EH36 substrate. When only ICCP was used, a relatively thin layer of calcium magnesium was deposited on the surface of EH36. Marine fouling organisms adhere to the surface of calcium and magnesium sedimentary layers and the EH36 substrate, and their attachment affects the formation of calcium and magnesium sedimentary layers. Moreover, marine fouling organisms cause corrosion on the surface of the EH36 substrate. The joint protection of seawater electrolysis antifouling and ICCP can simultaneously prevent electrochemical corrosion and marine biological fouling corrosion on the surface of EH36.