Angle Analysis Research Articles

Resistive ink based polarization and incident angle independent wideband absorber for RCS reduction at KU and K band

In this paper, a thin, single layered, wideband, polarization-insensitive, frequency selective surface absorber for radar cross section reduction (RCS) at KU and K bands has been studied analytically and experimentally. The lossy resistive patterns on unit cell is printed using resistive ink and arranged periodically over a low-cost metal-backed FR-4 dielectric substrate. Through appropriate design and optimization, the proposed absorber demonstrates above 90 % absorption for broadband ranging from 15 GHz to 26.6 GHz, with multi-absorption peaks at 15.7, 18.5, and 22.9 GHz. The structure shows a high absorptivity of 96.8 % in the KU band and 95.7 %, and 99.3 % in the K band at the above mentioned frequencies. A fractional bandwidth of 55.8 % has been obtained at the expense of a thickness of 0.0835 λ1 (λ1 being the wavelength associated with the lower absorbing frequency). The absorption mechanism has been described with the help of surface current distribution, induced electric field, and equivalent circuit. Further, for both TE and TM waves, analysis of various polarization angles and oblique incidence angles have been investigated. It shows polarization insensitivity to normal incidence and a stable response up to 60° for oblique incidence to TM wave. The proposed absorber’s novelty comes through its thin, single-layered structure with wide band response at the KU and K frequency bands via a unique resistive ink pattern on a low cost FR-4. A prototype of the absorber has been fabricated and measured results have been validated with simulated results. A proposed single layered, wideband, thin, polarization, and angular stable absorber using resistive ink is commercially viable for RCS reduction applications at the KU and K band.

Accurate and Robust Static Hydrophobic Contact Angle Measurements Using Machine Learning.

We present a machine learning (ML) approach to static contact angle measurement, trained on a large data set (>7.2 million) of half drop contours based on solutions to the Young-Laplace equation where the contact angle is known a priori (removing all sources of error from human input). The data set included the effects of surface roughness, gravity, the size of drop relative to the image, and reflections of the drop on the surface. The presented ML model (valid for contact angles >110°), in combination with a new automated image and contour processing approach, is shown to be more accurate than other methods when benchmarked against an experimental data set, with an estimated error of 1°. The ML model is also 2 orders of magnitude faster at predicting contact angles than Young-Laplace fitting (the current best practice approach). The accuracy and speed of the presented approach provides a viable pathway toward robust and reproducible high-throughput contact angle analysis. This approach, Conan-ML, is open-source and provided for the use and development of new approaches to goniometry.

Maltodextrin-modified graphene oxide composite membrane applied to the enantioseparation of amino acids

The separation of enantiomers using chiral membranes has garnered much research interest. In this study, the enantioseparation of amino acids using chiral membranes, namely graphene oxide-ethylenediamine-maltodextrin (GO-EDA-MD) and GO-EDA-hydroxypropyl-MD (GO-EDA-HP-MD), was evaluated. HP-MD and MD were investigated as chiral selectors due to their inherent chirality. Various characterization techniques, including atomic force microscopy, Fourier transform infrared spectrometry, field emission scanning electron microscopy, water contact angle analysis, tensile properties, and thermal gravimetric analysis were employed to analyze the membrane structures. The evaluation of enantioseparation performance was conducted by employing tryptophan, phenylalanine, and tyrosine enantiomers. Optimal conditions for enantiomer separation were achived using a GO-EDA-HP-MD chiral composite (1.75 wt%), a feed concentration of 10 mg/L for each enantiomer, a separation time of 15 min, and a membrane effective surface area of 1.0 cm2. Also, the bovine serum albumin rejection was 90.0 %, and the water flux reached 37.1 L m−2 h−1. The highest enantiomeric excess (ee.%) values were 46.33 %, 76.97 %, and 73.04 % for tryptophan, phenylalanine, and tyrosine, respectively. The impact of voltage on ee.% and substance flux was also explored. This membrane was able to separate enantiomers successfully.

Dehydration of bioethanol using novel polysulfone (PSF)/nonionic surfactants hybrid membranes

This study focuses on developing a novel polysulfone (PSF) dense hybrid membrane modified with nonionic surfactants, Tween 20 (T20) and Triton X-100 (X100), for improved pervaporation (PV) dehydration of bioethanol. The modified membranes were then examined for their ethanol dehydration performance, microscopy and spectroscopy characteristics, surface charge, mechanical and roughness properties, crystallinity structure, differential scanning calorimetry (DSC), swelling, and contact angle (CA) analysis. The free volume structure of the membranes was assessed using positron annihilation lifetime spectroscopy (PALS) and Doppler broadening spectroscopy (DBS). A significant discovery from this analysis was the semi antiplasticizing effect observed when surfactants were added to the PV membranes. The PV results revealed that incorporating 0.5 wt% T20 into PSF significantly improved the total flux and PSI of PSF/T20 to 226.35 g/m2 h and 46578 g/m2 h, respectively. Similarly, the total flux and PSI of hybrid membranes containing X100 increased to 110.19 g/m2 h and 43680 g/m2 h. Consequently, the developed PSF/T20 membranes demonstrated more significant potential for bioethanol dehydration compared to PSF/X100 membranes.

Effects on dentin nanomechanical properties, cell viability and dentin wettability of a novel plant-derived biomodification monomer

ObjectivesTo evaluate the effects of dentin biomodification agents (Proanthocyanidin (PAC), Cardol (CD) and Cardol-methacrylate (CDMA) on dentin hydrophilicity by contact angle measurement, viability of dental pulp stem cells (DPSCs) and nanomechanical properties of the hybrid layer (HL). MethodsCDMA monomer was synthesized from cardol through methacrylic acid esterification. Human extracted third molars were used for all experiments. For nanomechanical tests, specimens were divided in four groups according to the primer solutions (CD, CDMA, PAC and control) were applied before adhesive and composite coating. Nanomechanical properties of the HL were analyzed by nanoindentation test using a Berkovich probe in a nanoindenter. Wettability test was performed on dentin surfaces after 1 min biomodification and measured by contact angle analysis. Cytotoxicity was assessed by a MTT assay with DPSCs after 48 and 72 h. Data were analyzed with Student's t test or Two-way ANOVA and Tukey HSD test (p < 0.05). ResultsCD and CDMA solutions achieved greater hydrophobicity and increased the water-surface contact angles when compared to PAC and control groups (p < 0.05). PAC group showed a greater reduction of elastic modulus in nanoindentation experiments when compared to CD and CDMA groups (p < 0.05) after 4 months of aging. CD inhibited cell proliferation compared to all further materials (p < 0.05), whilst CDMA and PAC indicated no cell cytotoxicity to human DPSCs. SignificanceCardol-methacrylate provided significantly higher hydrophobicity to dentin and demonstrated remarkable potential as collagen crosslinking, attaining the lowest decrease of HL’s mechanical properties. Furthermore, such monomer did not affect pulp cytotoxicity, thereby highlighting promising feasibility for clinical applications.

The anti-fouling and mechanism of Fe3O4@PVDF catalytic membrane in-situ coupling Fenton oxidation for organic pollutants removal

Polyvinylidene fluoride (PVDF) membrane is a promising technique for deep treatment of organic wastewater. However, the unavoidable membrane contamination greatly restrictions its field of application. Herein, we successfully prepared Fe3O4@PVDF membrane with excellent anti-fouling and catalytic ability by non-solvent induced phase inversion method. Meanwhile, Fe3O4@PVDF membrane was characterized by SEM, XRD, FTIR, Water contact Angle and membrane aperture analyzer. The properties of separation and anti-fouling were also evaluated by cross flow filtration of humic acid (HA). Compare with pristine membrane, the pure water flux, rejection rate and FRR respectively increase from 556.81 L m-2 h−1, 65.42 %, 68.26 % to 656.96 L m-2 h−1, 99.64 %, 90.17 % under in-situ Fenton reaction condition. In addition, further mechanistic insights by XDLVO theory, 3D-EEM and EPR verified that high anti-fouling mainly attribute to excellent hydrophilicity of Fe3O4@PVDF and in-situ degradation of HA by OH and 1O2· This work provides insights for improving the separation properties and anti-fouling properties of PVDF membrane in the field of treatment organic wastewater.

Enhancing Esthetics in Direct Dental Resin Composite: Investigating Surface Roughness and Color Stability.

Dental restorations must replicate the natural appearance of teeth while ensuring biocompatibility and durability. This study evaluated the surface characteristics and color stability of three dental composites-Herculite Ultra XRV, G-ænial A'CHORD, and Omnichroma-exposed to acidic beverages (red wine, black coffee, and Coca-Cola). Sixty disk-shaped specimens were prepared, polished, and immersed in these beverages. Surface roughness was assessed using profilometry and SEM analysis, hydrophobicity via contact angle analysis, and surface charge through streaming potential measurements. Color stability was evaluated using a spectrophotometer, and the pH levels of the solutions were recorded. Results showed that Herculite Ultra XRV had the highest mean contact angle (79.46° ± 6.52), indicating superior hydrophobicity, while Omnichroma had the lowest (64.94° ± 3.08), indicating more hydrophilicity. Significant color changes were observed, especially in black coffee, with ∆E values indicating notable discoloration. The acidic pH of the solutions increased surface roughness and color changes. Statistical analyses confirmed significant increases in surface roughness and color change for all composites, with the nanohybrid resin composite showing the greatest variability. These findings highlight the need for dental restorative materials with enhanced resistance to acidic environments to improve the longevity and esthetics of dental treatments.

Morphometric Analysis of Glenopolar Angle of the Scapula in Indian Population.

The glenopolar angle (GPA),usually ranges from 30° to 45°. GPA measures the tilt of the plane of the glenoid cavity in relation tothe axis of the body of the scapula passing from the superior pole of the glenoid cavity to the inferior angle of the scapula.It is essential to assess the results of surgeries for dislocated shoulders. Worse long-term outcomes can arise from glenoid misalignment in scapular neck fractures. When evaluating prognosis and planning therapy for shoulder injuries including scapular fractures, GPA assessment is essential. Still, there is a dearth of data on the normal range of GPA and its contributing elements, which calls for more study. The purpose of this study is to determine typical GPA values by utilizing radiographs and a sizable sample of scapular bone specimens. In this study, the GPA was assessed in 50 chest radiographs of anteroposterior (AP) view and Neer's view of individuals as well as 100 dried scapulae of any gender. The mean GPA obtained using the various methods was then statistically compared. All scapulae had an average GPA of 42.6°. Twenty-ninescapulae had GPA observations higher than 45°, with an average of 47.2°. Twenty-seven scapulae had GPA measurements below 40°, averaging 37.3°.Right-sided 62 scapulae with an average GPA of 43.1°were present. Thirty-eight of left-side scapulae had a GPA of 41.7° on average. It was determined that the 1.6° mean difference in GPA between the two groups was not statistically significant. The Kolmogorov-Smirnov test verified that the GPA data had a normal distribution. The homogeneity of variances across various measuring techniques was confirmed using Levene's test. The average GPA measured using the dry scapula approach was 42.6°, the average GPA measured using the AP view was 39.8°, and the average GPA measured using the Neer I view was 42.3°. The GPA means from these three approaches differed considerably (p=0.0014) according to a one-way Analysis of Variance (ANOVA). Fisher's least significant difference post hoc testing showed thatthe scapular bone specimens and the Neer I view revealed significantly higher GPA values than AP shoulder radiographs.The GPA values obtained from the osteological group and the Neer I perspective had a mean difference of 0.21°, which was practically identical and suggested that there was no statistically significant difference between these approaches. In order to diagnose and treat a variety of shoulder joint diseases, this study estimates the normal values of scapular GPA. Furthermore, it offers support for improved implant design in the context of Indian shoulder joint replacement and repair.Using every measurement technique, the GPA values on the right and left sides did not differ significantly.GPA results from various measuring methods varied significantly, which emphasizes the significance of methodological consistency in clinical and research settings.

Improving membrane distillation performance by Fe(II) activated sodium percarbonate oxidation during the treatment of shale gas produced water

Membrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.54 % and 54.52 %, respectively. The hydrophobic fraction decreased from 52.75 % in raw SGPW to 37.70 % and 27.20 % for SPC and Fe(II)/SPC, respectively, and the MD normalized flux increased from 0.19 in treating raw SGPW to 0.65 and 0.81, respectively. The superiority of SPC oxidation in reducing the deposited membrane foulants and restoring membrane properties was further confirmed through scanning electron microscopy observation, attenuated total reflection fourier transform infrared, water contact angle and surface tension analyses of fouled membranes. Correlation analysis revealed that hydrophobic/hydrophilic matters and fluorescent organics in SGPW took a crucial role in MD fouling. The mechanism of MD fouling mitigation by Fe(II)/SPC oxidation was attributed to the decrease in concentrations and hydrophobicity of organic by synergistic oxidation, coagulation and adsorption.

Smartphone IMU Sensors for Human Identification through Hip Joint Angle Analysis.

Gait monitoring using hip joint angles offers a promising approach for person identification, leveraging the capabilities of smartphone inertial measurement units (IMUs). This study investigates the use of smartphone IMUs to extract hip joint angles for distinguishing individuals based on their gait patterns. The data were collected from 10 healthy subjects (8 males, 2 females) walking on a treadmill at 4 km/h for 10 min. A sensor fusion technique that combined accelerometer, gyroscope, and magnetometer data was used to derive meaningful hip joint angles. We employed various machine learning algorithms within the WEKA environment to classify subjects based on their hip joint pattern and achieved a classification accuracy of 88.9%. Our findings demonstrate the feasibility of using hip joint angles for person identification, providing a baseline for future research in gait analysis for biometric applications. This work underscores the potential of smartphone-based gait analysis in personal identification systems.

Synchronous analysis of ankle coronal plane tilt angle and peripheral associated muscle load in semi-squat landing of paratroopers

Objective: To investigate the relationship between ankle stability and associated muscle load around the ankle and the effect of a parachute ankle brace (PAB) on ankle inversion and associated muscle load around the ankle during landing through the simulated paratrooper semi-squat landing field experiment. Methods: In August 2021, 37 male paratroopers were randomly selected as the study objects to perform parachute landing training in the semi-squat posture on the 1.5 m and 2.0 m jump platforms with or without PAB, respectively. The coronal plane tilt angle of ankle joint and the percentage of maximum voluntary contraction (MVC%) of associated muscles around ankle joint during the process were measured and correlation analysis was conducted. And the effect of wearing PAB on the coronal plane tilt angle of ankle joint and the associated muscles around the ankle joint was analyzed. Results: During the semi-squat landing, the MVC% of the tibialis anterior muscle, lateral gastrocnemius muscle and peroneus longus muscle were positively correlated with the ankle coronal plane tilt angle in paratroopers wearing and without wearing PAB, and the correlations were statistically significant (P<0.05). At the same height, compared with those without PAB, the coronal plane tilt angle of the ankle joint decreased during semi-squat landing in paratroopers PAB, and the differences were statistically significant (P<0.05). At the landing moment of the same height, compared with those without PAB, the MVC% of lateral gastrocnemius muscle decreased and the MVC% of peroneus longus muscle increased in paratroopers wearing PAB, and the differences were statistically significant (P<0.05). After the landing moment until the standing stage (100-200 ms) at 1.5 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the differences were statistically significant (P<0.05). In the post-standing stage (200 ms) at 2.0 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the difference was statistically significant (P<0.05) . Conclusion: Wearing PAB can reduce the ankle coronal plane tilt angle, improve ankle stability, reduce the muscle load of the lateral gastrocnemius muscle at the moment of landing, and reduce the load of the tibialis anterior muscle after landing, but increase the peroneus longus muscle load at the moment of landing.

Functionalised carbon nanotube thin film nanocomposite membranes: A comparison study on the role of backbone monomers and hydraulic pressure on membrane's performance and fouling

Thin film nanocomposite (TFN) reverse osmosis (RO) and nanofiltration (NF) membranes have attracted considerable attention for industrial applications in recent years. Among recent nanomaterials used in the fabrication of TFN membranes, carbon nanotubes (CNTs) have gained significant interest due to their unique structure (e.g., tubular shape, mechanical strength, porosity, etc.). Here, the effects of multi-walled carbon nanotubes (MWCNTs) with different functional groups as one of the well proven nanchannel structures and their interaction with two typical monomers, MPD and PIP, were thoroughly investigated. All fabricated membranes were analysed using SEM, FTIR, AFM and contact angle analyzer. Pressure variation significantly affected the performance of membranes over 24 hours of testing. The membranes incorporated with polypyrrole (PPy) modified MWCNTs showed promising results with nearly 37 % and 99 % water flux improvement for the TFN-RO and NF membranes, respectively, compared to the bare (unmodified) TFC RO/NF membranes. Specifically, the water flux of the RO OX-MWCNTs-PPy membrane increased from 18.9 to 25.5 L.m−2.h−1, while the NF OX-MWCNTs-PPy membrane's water flux rose from 45.2 to 90.1 L.m−2.h−1. The salt rejection of RO and NF remained relatively high, with over 90 % salt rejection against NaCl and Na2SO4 for RO and NF membranes. The NF OX-MWCNTs-PPy membrane exhibited a 98.2 % rejection rate for Na2SO4, and the RO OX-MWCNTs-PPy membrane showed around a 98.8 % rejection rate for NaCl. The TFN membranes showed less fouling tendency compared to the TFC membranes. In general, the integration of MWCNTs with various functional groups significantly enhanced the water flux and salt rejection properties of these membranes. Specifically, the modified membranes showed considerable improvements in water flux and maintained high salt rejection rates. Additionally, the interaction between MWCNTs and PIP monomers in TFN-NF membranes exhibited a stronger affinity compared to MPD monomers in TFN-RO membranes, indicating a more promising performance for NF applications. The findings suggest that TFN-NF membranes incorporating MWCNTs hold great promise for future industrial use, offering enhanced performance and reduced fouling rates.

New approach for deacidification and consolidation of bone artifacts

Acidic conditions affect the archaeological bone in the burial and in uncontrolled display and storage environment or due to improper restoration processes. Accordingly, bones become weak and fragile. This study aims to evaluate nano calcium propionate and nano styrene butyl acrylate (used for the first time in the treatment of bones) at different concentrations for deacidification and consolidation of fragile bones. New bone samples were prepared. Artificial accelerated aging (acid and heat) was applied to prepare aged untreated samples. Deacidification and consolidation processes using the materials mentioned above were applied. The analytical techniques used were transmission electron microscope (TEM) and thermal gravimetric analysis (TGA) were used for morphological and thermal stability investigation for the prepared nano styrene butyl acrylate copolymer and its calcium propionate nonocomposites, a digital microscope and scanning electron microscope (SEM) for investigation of the surface morphology, pH value measurement, change of color measurement, attenuated total reflection—Fourier transform infrared spectroscopy (ATR/FTIR), contact angle (wettability), and X-ray diffraction analysis for measurement of bone crystallinity. The results proved that acid-heat aging affected bone properties such as changes in surface morphology and color, decrease in pH value, and contact angle. Bone samples became more crystalline, and the chemical composition of bone was also affected. The treatment of aged untreated bone samples with the materials used in this study improved their properties, such as increasing the pH value and contact angle. The surface morphology, color change, and crystallinity of bone improved and became more stable.

Nano/microgroove zirconium‐doped lanthanum oxide film with self‐aligned molecules for liquid crystal device application

Herein, we propose a brush‐coated zirconium‐doped lanthanum oxide (ZrLaO) film as a liquid crystal (LC) alignment layer. The film‐curing temperature was adjusted to 70, 150, and 230°C. Polarized optical microscopy and pre‐tilt angle analysis confirmed that there was uniform and homogeneous LC alignment on the 230°C cured ZrLaO film. Atomic force microscopy revealed that the surface had a nano/microgroove structure, which was caused by the shear stress generated by the brush‐coating process. This structure induced the uniform LC alignment. X‐ray photoelectron spectroscopy verified that the ZrLaO film was well‐formed on a glass substrate. The ZrLaO film displayed hydrophilic characteristics, and its surface energy increased as the film‐curing temperature increased. The ZrLaO alignment layer displayed suitable optical transmittance for LC device applications. The ZrLaO layer‐based twisted‐nematic LC cell exhibited more stable switching properties and better threshold voltage characteristics than conventional polyimide layers. Therefore, we expect that this brush‐coated ZrLaO layer will be a suitable LC alignment layer for LC device applications.

Synthesis of a novel polymer and design of carboxylate-terminated hyperbranched PEI-incorporated PVDF membranes for efficient oil-in-water emulsion separation

Polyvinylidene fluoride (PVDF) membranes utilizing ultrafiltration (UF) and microfiltration (MF) configurations have widely been used in many separation processes, including oil/water emulsions. Recently, there have been tremendous research interests in designing PVDF membranes on their structural-property relations as well as high separation performances. Herein we report the synthesis of a novel carboxylate-terminated hyperbranched polyethylenimine (CHPEI) using a facile three-step one-pot strategy to enhance the characteristics of PVDF membranes for oil/water emulsion separation. The first step involved the production of one amide and one carboxylate functional group per maleic anhydride molecule on the outer surface of polyethylenimine (PEI). The second step involved producing two additional carboxylate groups via amine-based Michael addition of alkenes using aspartic acid dimethyl ester hydrochloride, followed by basic hydrolysis. CHPEI-n-PVDF membranes having various CHPEI contents are further fabricated by a phase-inversion process, obtaining as free-stable flat-sheet membranes. The synthesized polymer and membranes were thoroughly characterized by FTIR and 1H NMR, SEM, EDX, mapping, AFM, and contact angle analysis. The incorporation of CHPEI into PVDF positively enhanced the hydrophilicity, and the WCA was significantly reduced from 80.6° to 59.5°. The maximum permeation flux was obtained using CHPEI-3-PVDF membranes, which was 200 % more than that obtained using pristine PVDF. The CHPEI-2-PVDF membranes exhibited a rejection performance of >99 % for separating oil-in-water emulsions. The incorporation of CHPEI into PVDF significantly improved the antifouling characteristics of the membranes. After 5 h of operation in separating oil-in-water emulsions, the flux recoveries of CHPEI-2-PVDF and CHPEI-3-PVDF were found to be 92 % and 97 %, respectively. CHPEI has demonstrated a considerable positive influence in improving the PVDF membrane’s performance, making it an excellent candidate for oily wastewater treatment because of its high rejection performance and excellent flux recovery ratio.

Electromagnetic analysis of the ITER wide angle viewing system components with a simplified approach

An electromagnetic (EM) analysis of the Optical Hinge (OH) and Optical Relay Unit (ORU) has been performed for the validation of their Final Designs. OH and ORU are reflective optical systems, being the starting ex-vessel components of the ITER diagnostic Wide Angle Viewing System (WAVS). These two components share a support structure, attached in turn to the Interspace Support Structure (ISS).The methodology for the realization of the EM analyses for components in fusion devices is not standardized. The choice of the method highly depends on the goals of the study, on the required accuracy of results and on the available resources. A methodology to perform the EM analysis has been developed and validated. In the EM analysis, the arising EM forces have been calculated with a finite element 3D model, and the results obtained were used for the successive structural analysis.The publication presents the methodology developed, its implementation to the OHORU components, the results obtained for the validation of their Final Designs and additional studies for the methodology validation.

Chitosan electrolyte hydrogel with low ice adhesion properties

Icephobic materials can prevent or reduce ice formation, e.g. by ensuring easy detachment, a desirable property for those applications where ice accumulation is critical to human safety. Herein, we develop a chitosan electrolyte hydrogel to create a bio-based surface with low ice adhesion. The chitosan electrolyte hydrogel is physically crosslinked and infused with salted water at concentrations from 4.5 to 30 g/L, including that of seawater (23 g/L). Depending on salt content in the hydrogel, we could obtain very low ice adhesion down to 140 kPa (at – 10°C). We hypothesize that the chitosan electrolyte hydrogel exploits the colligative properties of water avoiding the ice nucleation at the ice-hydrogel interface. To confirm the hypothesis, we investigate the chitosan electrolyte hydrogel structure by contact angles analysis, DSC, TGA, FTIR, XRD, and by rheometry for mechanical properties. We quantify the presence of non-freezing water, which creates a lubricating liquid water layer at the ice-hydrogel interface, affecting the ice detachment mechanism and lowering ice adhesion. In conclusion, the proposed chitosan electrolyte hydrogel presents a bio-based and cost-efficient strategy for ice detachment across various icing scenarios for systems operating in humid marine environments, such as offshore platforms and ships.

Deep eutectic solvent engineered GO/ZrO2 nanofiller for mixed matrix membranes: An efficient hydrogen gas separation

AbstractThis study explores fabrication and characterization of mixed matrix membranes (MMMs) for gas separation, employing a cost‐effective solution casting method. Polycarbonate (PC) and polystyrene (PS) blends are combined with graphene oxide (GO) and zirconium dioxide (ZrO2) nanofillers, with and without a deep eutectic solvent (DES) obtained through hydrogen bond exchange. Various MMMs compositions (2–20 wt%) are systematically examined using diverse characterization techniques, including differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, porosity determination, and water contact angle analysis. The MMMs exhibit enhanced gas permeability and selectivity, surpassing conventional membrane materials. Notably, H2 gas permeability reaches outstanding levels, with the composition PC/PS‐DES‐GO/ZrO2 at 20 wt% (PBC20‐IV) demonstrating the highest value of 86.32 Barrer. This superior performance is attributed to the unique properties of ZrO2, increased sorption capacity of GO, and enhanced thermal stability due to DES. Permeability data for CO2, N2, O2, and CH4 also show significant values, aligning with the observed trends in H2 permeability. Robeson's plot for the H2/CO2 gas pair surpasses the 2008 upper bound, placing the MMMs in a novel category for gas separation membranes. The incorporation of DES‐modified nanofiller blend composites presents a promising strategy for the potential production of pure hydrogen.

Quantitative Characterization of Adhesion Work on Shale Surfaces and Discussion on the Influence of Roughness Based on Atomic Force Microscopy (AFM).

Adhesion is an intrinsic property of rocks and liquids. Investigating the factors contributing to its formation and the mechanisms governing its action is crucial for elucidating the adhesion work between solids and liquids. The adhesion work, serving as a parameter that characterizes the energy changes during the solid-liquid contact process, is a vital tool for probing this phenomenon. However, conventional measurements of the adhesion work are significantly influenced by surface roughness and fail to differentiate local variations in the adhesion performance. This limitation obscures our understanding of the primary adsorption sites and mechanisms between solids and liquids, posing significant challenges to the study of rock surface properties. In this study, in conjunction with scanning electron microscopy and contact angle analyses, we elucidated for the first time the locations where voids form during the solid-liquid contact process, the lithological composition of rough areas, and their impact on the adhesion work between water/oil and the surfaces. Additionally, employing atomic force microscopy (AFM), we examined the variations in water/oil-solid adhesion work across different characteristic regions, thereby characterizing the overall hydrophilic/hydrophobic properties of the rock core. Specific conclusions are as follows: (1) A negative correlation exists between roughness and the contact angle adhesion work, with heterogeneity impeding liquid-rock contact; (2) By comparing the strength of water-solid/oil-solid adhesion work within localized areas, we delineated the adhesion work characteristics of samples and their primary generation sites, with oil-solid adhesion work in target blocks predominantly originating from quartz, clay minerals, and organic matter; (3) The influence of pore throat development on the overall adhesion work of samples was clarified, demonstrating that an increase in the proportion of internal rock pores enhances the surface oil-solid adhesion work; (4) A dimensionless wetting index I was established to mitigate the impact of roughness on the expression of adhesion work, exhibiting a strong correlation with traditional evaluation methods.

Evaluating inter- and intraobserver reliability in radiographic determination of wrist alignment following scaphoid excision and four-corner arthrodesis

BackgroundFour-corner arthrodesis is commonly performed for advanced collapse patterns of wrist arthritis. Reduction of the capitolunate (CL) angle during four-corner fusion is crucial to allow for the greatest radiocarpal joint arc of motion. Previous studies demonstrate variable inter- and intraobserver reliability of measuring the CL angle. However, in a four-corner fusion, hardware implementation and scaphoid excision can complicate carpal alignment measurements. The purpose of this study is to investigate inter- and intraobserver reliability of measuring carpal alignment parameters following scaphoid excision and four-corner arthrodesis. MethodsThree fellowship-trained orthopaedic hand surgeons evaluated 30 posteroanterior and lateral radiographs of wrists after scaphoid excision and four-corner fusion. Radiographic evaluation included analysis of the radiolunate angle (RL), CL angle, lunate posture, carpal height, carpal height ratio, hardware impingement, and arthrodesis technique. Intraclass correlation coefficients (ICCs) and kappa values were used to evaluate reliability of radiographic measurements. ResultsRL and CL angles demonstrated very good inter- (ICCs: 0.657 and 0.693, respectively) and intraobserver agreement (ICCs: 0.576 to 0.924 and 0.596 to 0.811, respectively). Hardware impingement metrics by dorsal prominence and radiocarpal prominence had excellent interobserver reliability of 0.821 and 0.803, respectively. ICC values for arthrodesis technique were equal to 1.00. The inter- and intraobserver ICC values for the number of screws/staples used were in excellent agreement ranging from 0.910 to 1.000. ConclusionsOur study demonstrated favorable intra- and interobserver reliability at assessing carpal alignment following scaphoid excision and four-corner arthrodesis and these metrics potentially could be used in future research to evaluate long-term surgical outcomes. Level of evidenceLevel III, retrospective cohort study.