Search

The current study explores microbiologically influenced corrosion (MIC) of carbon steel API 5L X65 with and without the presence of sulfate-reducing bacteria (SRB) in CO_2 environments. The Electrochemical Impedance Spectroscopy (EIS), potentiodynamic polarisation and Field Emission Scanning Electron Microscopy (FESEM) techniques were employed to analyse the carbon steel’s corrosion behaviour. The R_p values from the EIS signify lower values denoting the steel’s greater corrosion rate. FESEM micrographs found a uniform corrosion on specimens without SRB whereas a pitting corrosion on specimens with SRB. The study concludes that SRB accelerate the corrosion progression due to MIC.

Microplastics, which comprise one of the omnipresent threats to human health, are diverse in shape and composition. Their negative impacts on human and ecosystem health provide ample incentive to design and execute strategies to trap and degrade diversely structured microplastics, especially from water. This work demonstrates the fabrication of single-component TiO2 superstructured microrobots to photo-trap and photo-fragment microplastics. In a single reaction, rod-like microrobots diverse in shape and with multiple trapping sites, are fabricated to exploit the asymmetry of the microrobotic system advantageous for propulsion. The microrobots work synergistically to photo-catalytically trap and fragment microplastics in water in a coordinated fashion. Hence, a microrobotic model of "unity in diversity" is demonstrated here for the phototrapping and photofragmentation of microplastics. During light irradiation and subsequent photocatalysis, the surface morphology of microrobots transformed into porous flower-like networks that trap microplastics for subsequent degradation. This reconfigurable microrobotic technology represents a significant step forward in the efforts to degrade microplastics.

Microplastics, which comprise one of the omnipresent threats to human health, are diverse in shape and composition. Their negative impacts on human and ecosystem health provide ample incentive to design and execute strategies to trap and degrade diversely structured microplastics, especially from water. This work demonstrates the fabrication of single-component TiO2 superstructured microrobots to photo-trap and photo-fragment microplastics. In a single reaction, rod-like microrobots diverse in shape and with multiple trapping sites, are fabricated to exploit the asymmetry of the microrobotic system advantageous for propulsion. The microrobots work synergistically to photo-catalytically trap and fragment microplastics in water in a coordinated fashion. Hence, a microrobotic model of "unity in diversity" is demonstrated here for the phototrapping and photofragmentation of microplastics. During light irradiation and subsequent photocatalysis, the surface morphology of microrobots transformed into porous flower-like networks that trap microplastics for subsequent degradation. This reconfigurable microrobotic technology represents a significant step forward in the efforts to degrade microplastics.

Silver oxide (AgO) thin films were prepared by using a cylindrical direct current reactive magnetron sputtering system at 10−5 torr initial pressure on BK7 glass substrate. Samples deposited for 3, 5 and 7 minutes. Surface characterization of AgO thin films in the nanometer scale can be accurately determined using the atomic force microscopy (AFM) and X-ray diffraction (XRD). The average roughness (Ravg), maximum peak to valley height (Rt) and root mean square (Rrms) roughness are used to analyze the surface morphology of AgO films. The linear optical absorption data were measured in the visible-near infrared spectral regions and the nonlinear refractive index (n2) of thin films is evaluated by the moiré deflectometery technique. The investigation indicates that, increase in AgO thickness leads to reduction in nonlinear refractive index., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., ImPhys/Menzel group

This manuscript reports the electrosynthesis of ammonia from nitrate catalysed Cu derived from Cu2O materials. Cu2O (111) and (100) preferential grain orientations were prepared through electrodeposition. Cu derived from Cu2O (111) is more active and selective for ammonia formation than Cu2O (100) derived Cu. The highest faradaic efficiency (FE) was achieved for both catalysts at −0.3 V vs RHE, with Cu derived from Cu2O (111) reaching up to 80 %. Additional measurements with quasi-in situ X-ray photoelectron spectroscopy and in situ Raman spectroscopy revealed that Cu0 is the active phase during the reaction. The stability of the catalysts was examined by ex situ methods such as SEM, XRD and ICP elemental analysis. The catalysts underwent severe morphological changes as a function of the applied potential and the reaction time, most likely due to the dissolution and redeposition of Cu. After 3 hours of reaction, the entire surface of the catalysts was reconstructed into nanoneedles. The FE after 3 hours remained higher for the Cu derived from Cu2O (111), suggesting that the activity is dependent on the initial structure and the different rates of dissolution and re-deposition.

The current study explores microbiologically influenced corrosion (MIC) of carbon steel API 5L X65 with and without the presence of sulfate-reducing bacteria (SRB) in CO_2 environments. The Electrochemical Impedance Spectroscopy (EIS), potentiodynamic polarisation and Field Emission Scanning Electron Microscopy (FESEM) techniques were employed to analyse the carbon steel’s corrosion behaviour. The R_p values from the EIS signify lower values denoting the steel’s greater corrosion rate. FESEM micrographs found a uniform corrosion on specimens without SRB whereas a pitting corrosion on specimens with SRB. The study concludes that SRB accelerate the corrosion progression due to MIC.

This manuscript reports the simultaneous electrodeposition of Cu and Rh from an aqueous nitrate solution. The early stages of nucleation and growth of the bimetallic layer were explored using techniques such as cyclic voltammetry and current transients. Non-dimensional Scharifker-Hills graphs showed the occurrence of diffusion-controlled three-dimensional nucleation and growth best described by the Volmer-Weber mechanism. Additionally, different ratios of Cu−Rh electrodes were synthesized by varying the potential of deposition and the Rh content in the deposition bath. Characterization techniques including electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy were employed to investigate the chemical composition and structure of the deposits. The results showed a higher amount of Cu2+ species in the layer than Cu+/Cu0 when a more negative potential was applied, and when Rh was present in high amounts in the deposition bath. The final morphology of the obtained material proved to be dependent on the deposition potentials and the Cu : Rh content, showing interdependency between the metals.

Accelerator scientists have high demands on photocathodes possessing high quantum efficiency (QE) and long operational lifetime. p-GaN, as a new photocathode type, gained recently more and more interest because of its ability to form a negative electron affinity (NEA) surface. Being activated with a thin layer of cesium, p-GaN:Cs photocathodes promise higher QE and better stability than the known photocathodes. In our study, p-GaN samples grown on sapphire or silicon were wet chemically cleaned and transferred into an ultra-high vacuum (UHV) chamber, where they underwent a subsequent thermal cleaning. The cleaned p-GaN samples were activated with cesium to obtain p-GaN:Cs photocathodes and their performance was monitored in respect to their quality, especially their QE and storage lifetime. The surface topography and morphology were examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM) in combination with energy dispersive x-ray (EDX) spectroscopy. We have shown that p-GaN could be efficiently reactivated with cesium for several times. This paper compares systematically the influence of wet chemical cleaning as well as thermal cleaning at various temperatures on the QE, storage lifetime and surface morphology of p-GaN. As expected, the cleaning influences strongly the cathodes’ quality. We show that high QE and long storage lifetime are achievable at lower cleaning temperatures in our UHV chamber.

Origin-files zur Darstellung von thermischen Reinigung, Aktivierung und Quanteneffizienz-Überwachung von GaN Fotokathoden SEM Bilder als .tif Dateien EDX Spektren als Exel-files zur Darstellung von EDX Analysen AFM Orginal Bilder die mit dem Programm Gwiddion geöffnet werden können

One of the primary difficulties in treating patients with genetic syndromes is diagnosing their condition. Many syndromes are associated with characteristic facial features that can be imaged and utilized by computer-assisted diagnosis systems. In this work, we develop a novel 3D facial surface modeling approach with the objective of maximizing diagnostic model interpretability within a flexible deep learning framework. Therefore, an invertible normalizing flow architecture is introduced to enable both inferential and generative tasks in a unified and efficient manner. The proposed model can be used (1) to infer syndrome diagnosis and other demographic variables given a 3D facial surface scan and (2) to explain model inferences to non-technical users via multiple interpretability mechanisms. The model was trained and evaluated on more than 4700 facial surface scans from subjects with 47 different syndromes. For the challenging task of predicting syndrome diagnosis given a new 3D facial surface scan, age, and sex of a subject, the model achieves a competitive overall top-1 accuracy of 71%, and a mean sensitivity of 43% across all syndrome classes. We believe that invertible models such as the one presented in this work can achieve competitive inferential performance while greatly increasing model interpretability in the domain of medical diagnosis.

Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.

Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.

Hexagonal boron nitride has already been proven to serve as a decent substrate for high quality epitaxial growth of several 2D materials, such as graphene, MoSe2, MoS2 or WSe2. Here, we present for the first time the molecular beam epitaxy growth of MoTe2 on atomically smooth hexagonal boron nitride (hBN) substrate. Occurrence of MoTe2 in various crystalline phases such as distorted octahedral 1T' phase with semimetal properties or hexagonal 2H phase with semiconducting properties opens a possibility of realization of crystal -phase homostructures with tunable properties. Atomic force microscopy studies of MoTe2 grown in a single monolayer regime enable us to observe impact of growth conditions on formation of various structures: flat grains, net of one-dimensional structures, quasi continuous monolayers with bilayer contribution. Comparison of the distribution of the thickness with Poisson distribution shows that tested growth conditions favorite formation of grains with monolayer thickness. The diffusion constant of MoTe2 grown on hBN can reach order of 10-6 cm2/s for typical growth conditions. Raman spectroscopy results suggest a coexistence of various phases with domination of 2H MoTe2 for samples grown at lower temperatures. XPS measurements confirm the stoichiometry of MoTe2.

Ti-6Al-4V is one of the widely used load-bearing implant materials due to its unique set of combinatorial properties such as biocompatibility and enhanced mechanical properties. However, after being implanted, these biomaterials can trigger difficulties in patients due to infections mainly caused by bacterial adhesion. Their good corrosion performance is mainly explained by the formation of a dense and passive oxide layer on their surface. Nevertheless, this oxide film alone does not have enough surface characteristics like bioactivity, antimicrobial activity, corrosion resistance, osseointegration, roughness, biocompatibility, fatigue, and wear to provide good performance for biomedical applications. For that reason, others surface modifications on these alloys are required. In that direction, the surface modification of plasma electrolytic oxidation (PEO) is of great interest given its low cost and environmentally friendly nature. PEO had been widely studied on Ti-6Al-4V alloys, especially on substrates made by conventional manufacturing like forged. However, currently, most implants are manufactured by additive manufacturing techniques (electron beam melting, selective laser melting) and the effect of PEO on substrates manufactured by these techniques has not been completely studied, especially by the electron beam melting technique. In this work, the morphology, chemical composition, and phase composition of the PEO coatings on substrates manufactured by the EBM technique were analyzed by Scanning Electron Microscopy (SEM) with energy-dispersive x-ray spectroscopy (EDS) and X-ray diffraction (XRD). PEO coatings characteristics like thicknesses, pore sizes, and layer homogeneity along the built direction of the printed part and its transversal direction were measured with the purpose to evaluate the effect of the anisotropic of printed substrates over the PEO layer growth. For comparative analysis, PEO coatings on the forged substrates were evaluated to analyze t

In the quest for decreasing fuel consumption and resulting gas emissions in the aeronautic sector, lightweight materials such as Carbon Fiber Reinforced Polymers (CFRPs) and Ti-6Al-4V alloys are being used. These materials, with excellent weight-to-strength ratios, are widely used for structural applications in aircraft manufacturing. To date, several studies have been published showing that the use of metalworking fluids (MWFs), special tool geometries, or advanced machining techniques is required to ensure a surface quality that meets aerospace component standards. Conventional MWFs pose a number of environmental and worker health hazards and also degrade the mechanical properties of CFRPs due to water absorption in the composite. Therefore, a transition to more environmentally friendly cooling/lubrication techniques that prevent moisture problems in the composite is needed. This research shows that lubricated LCO2 is a viable option to improve the quality of drilled CFRP and titanium aerospace components compared to dry machining, while maintaining clean work areas. The results show that the best combination of tool geometry and cooling conditions for machining both materials is drilling with Brad point drills and lubricated LCO2. Drilling under these conditions resulted in a 90 % improvement in fiber pull-out volume compared to dry machined CFRP holes. In addition, a 33 % reduction in burr height and a 15 % improvement in surface roughness were observed compared to dry drilling of titanium.

In this article, we present a novel electronic nose fabrication process based on highly programmable anodic aluminum oxide (AAO) nanoarchitectonics and ultrasonic spray pyrolysis (USP) deposition. Featuring an ultralow manufacturing cost, the deposited material’s morphology can be accurately controlled with fabricated general-purpose AAO template. Compared with nonstandard lithography-based template fabrication method, the need of complicated Bosch etching process and its associated complex process parameter tuning is eliminated. As a result, the cost-effective mass production of 3-D nanotemplate-based material and devices can be enabled. In addition, the target material’s limited coverage and time efficiency issues widely existing in the previous deposition methods are well-addressed by our customized USP deposition, especially for the 3-D nanotemplate with large surface-to-volume ratio, leading to significantly improved gas-sensing performance. Moreover, the proposed fabrication recipe, together with the adopted gas recognition algorithms based on linear discriminant analysis (LDA), is validated based on the reported extensive measurement results for five gas biomarkers widely exploited for patients’ exhaled gas-sensing and recognition applications. This shows great potential for the early disease diagnose of diabetes, breast cancer, acute lung injury, colon diseases, lung cancer, and so on. IEEE

Potholes are one of the most common forms of road damage, which can severely affect driving comfort, road safety, and vehicle condition. Pothole detection is typically performed by either structural engineers or certified inspectors. However, this task is not only hazardous for the personnel but also extremely time consuming. This article presents an efficient pothole detection algorithm based on road disparity map estimation and segmentation. We first incorporate the stereo rig roll angle into shifting distance calculation to generalize perspective transformation. The road disparities are then efficiently estimated using semiglobal matching. A disparity map transformation algorithm is then performed to better distinguish the damaged road areas. Subsequently, we utilize simple linear iterative clustering to group the transformed disparities into a collection of superpixels. The potholes are finally detected by finding the superpixels, whose intensities are lower than an adaptively determined threshold. The proposed algorithm is implemented on an NVIDIA RTX 2080 Ti GPU in CUDA. The experimental results demonstrate that our proposed road pothole detection algorithm achieves state-of-the-art accuracy and efficiency.

OBJECTIVE: To investigate cardiac activation maps estimated using electrocardiographic imaging and to find methods reducing line-of-block (LoB) artifacts, while preserving real LoBs.METHODS: Body surface potentials were computed for 137 simulated ventricular excitations. Subsequently, the inverse problem was solved to obtain extracellular potentials (EP) and transmembrane voltages (TMV). From these, activation times (AT) were estimated using four methods and compared to the ground truth. This process was evaluated with two cardiac mesh resolutions. Factors contributing to LoB artifacts were identified by analyzing the impact of spatial and temporal smoothing on the morphology of source signals.RESULTS: AT estimation using a spatiotemporal derivative performed better than using a temporal derivative. Compared to deflection-based AT estimation, correlation-based methods were less prone to LoB artifacts but performed worse in identifying real LoBs. Temporal smoothing could eliminate artifacts for TMVs but not for EPs, which could be linked to their temporal morphology. TMVs led to more accurate ATs on the septum than EPs. Mesh resolution had a negligible effect on inverse reconstructions, but small distances were important for cross-correlation-based estimation of AT delays.CONCLUSION: LoB artifacts are mainly caused by the inherent spatial smoothing effect of the inverse reconstruction. Among the configurations evaluated, only deflection-based AT estimation in combination with TMVs and strong temporal smoothing can prevent LoB artifacts, while preserving real LoBs.SIGNIFICANCE: Regions of slow conduction are of considerable clinical interest and LoB artifacts observed in non-invasive ATs can lead to misinterpretations. We addressed this problem by identifying factors causing such artifacts and methods to reduce them.

Hydrogenation of polycrystalline silicon (poly-Si) passivating contacts is crucial for maximizing their passivation performance. This work presents the application of Al2O3 prepared by atomic layer deposition as a hydrogenating capping layer. Several important questions related to this application of Al2O3 are addressed by comparing results from Al2O3 single layers, SiNx single layers, and Al2O3/SiNx double layers to different poly-Si types. We investigate the effect of the Al2O3 thickness, the poly-Si thickness, the poly-Si doping type, and the postdeposition annealing treatment on the passivation quality of poly-Si passivating contacts. Especially, the Al2O3/SiNx stack greatly enhances the passivation quality of both n+ and p+ doped as well as intrinsic poly-Si layers. The Al2O3 layer thickness is crucial for the single-layer approach, whereas the Al2O3/SiNx stack is less sensitive to the thickness of the Al2O3 layer. A thicker Al2O3 layer is needed for effectively hydrogenating p+ compared to n+ poly-Si passivating contact. The capping layers can hydrogenate poly-Si layers with thicknesses up to at least 600 nm. The hydrogenation-enhanced passivation for n+ poly-Si is found to be more thermally stable in comparison to p+ poly-Si. These results provide guidelines on the use of Al2O3 capping layers for poly-Si contacts to significantly improve their passivation performance.

Crosslinked polyethylene (XLPE) insulation is widely used in power cables because of its excellent properties. Due to the remoteness of end users, the energy is generally transported over long distances. These cables cross various areas being sometimes exposed to different environmental stresses that affect their performance and increase their degradation. While most published literatures are limited to laboratory scales, this article uniquely deals with a multiscale analysis of a 30 months naturally weathered XLPE samples in two harsh environments. The first site is a marine environment with high humidity level, sea salt content in the air, seasonal variation of temperature, and concomitant radiation doses. The second one is a desert environment characterized by extremely high temperatures, which reached 50 °C during summer, coupled with thermal cycling and large solar radiation doses with UV rays of high energy wavelengths. Modifications in the XLPE insulation characteristics due to weathering were studied using different experimental techniques. The testing matrices included dielectric and mechanical characterization, scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and differential scanning calorimetry (DSC) measurements on fresh and weathered XLPE insulation samples. It is found that the degradation rate was faster in the arid desert climate compared with the coastal one. Furthermore, correlation mechanisms between the obtained results are discussed in order to better understand the weathering degradations.

Hydrogenation of polycrystalline silicon (poly-Si) passivating contacts is crucial for maximizing their passivation performance. This work presents the application of Al2O3 prepared by atomic layer deposition as a hydrogenating capping layer. Several important questions related to this application of Al2O3 are addressed by comparing results from Al2O3 single layers, SiNx single layers, and Al2O3/SiNx double layers to different poly-Si types. We investigate the effect of the Al2O3 thickness, the poly-Si thickness, the poly-Si doping type, and the postdeposition annealing treatment on the passivation quality of poly-Si passivating contacts. Especially, the Al2O3/SiNx stack greatly enhances the passivation quality of both n+ and p+ doped as well as intrinsic poly-Si layers. The Al2O3 layer thickness is crucial for the single-layer approach, whereas the Al2O3/SiNx stack is less sensitive to the thickness of the Al2O3 layer. A thicker Al2O3 layer is needed for effectively hydrogenating p+ compared to n+ poly-Si passivating contact. The capping layers can hydrogenate poly-Si layers with thicknesses up to at least 600 nm. The hydrogenation-enhanced passivation for n+ poly-Si is found to be more thermally stable in comparison to p+ poly-Si. These results provide guidelines on the use of Al2O3 capping layers for poly-Si contacts to significantly improve their passivation performance.

Films prepared from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymers produced by Aneurinibacillus sp. H1 using an automatic film applicator were homogeneous and had a defined thickness, which allowed a detailed study of physicochemical properties. Their properties were compared with those of a poly (3-hydroxybutyrate) homopolymer film prepared by the same procedure, which proved to be significantly more crystalline by DSC and XRD. Structural differences between samples had a major impact on their properties. With increasing 4-hydroxybutyrate content, the ductility and release rate of the model hydrophilic active ingredient increased significantly. Other observed properties, such as the release of the hydrophobic active substance, the contact angle with water and ethylene glycol, or the surface morphology and roughness, were also affected by the composition. The identified properties predetermine these copolymers for wide use in areas such as biomedicine or smart biodegradable packaging for food or cosmetics. The big advantage is the possibility of fine-tuning properties simply by changing the fermentation conditions.

Films prepared from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymers produced by Aneurinibacillus sp. H1 using an automatic film applicator were homogeneous and had a defined thickness, which allowed a detailed study of physicochemical properties. Their properties were compared with those of a poly (3-hydroxybutyrate) homopolymer film prepared by the same procedure, which proved to be significantly more crystalline by DSC and XRD. Structural differences between samples had a major impact on their properties. With increasing 4-hydroxybutyrate content, the ductility and release rate of the model hydrophilic active ingredient increased significantly. Other observed properties, such as the release of the hydrophobic active substance, the contact angle with water and ethylene glycol, or the surface morphology and roughness, were also affected by the composition. The identified properties predetermine these copolymers for wide use in areas such as biomedicine or smart biodegradable packaging for food or cosmetics. The big advantage is the possibility of fine-tuning properties simply by changing the fermentation conditions.

OBJECTIVE: To investigate cardiac activation maps estimated using electrocardiographic imaging and to find methods reducing line-of-block (LoB) artifacts, while preserving real LoBs.METHODS: Body surface potentials were computed for 137 simulated ventricular excitations. Subsequently, the inverse problem was solved to obtain extracellular potentials (EP) and transmembrane voltages (TMV). From these, activation times (AT) were estimated using four methods and compared to the ground truth. This process was evaluated with two cardiac mesh resolutions. Factors contributing to LoB artifacts were identified by analyzing the impact of spatial and temporal smoothing on the morphology of source signals.RESULTS: AT estimation using a spatiotemporal derivative performed better than using a temporal derivative. Compared to deflection-based AT estimation, correlation-based methods were less prone to LoB artifacts but performed worse in identifying real LoBs. Temporal smoothing could eliminate artifacts for TMVs but not for EPs, which could be linked to their temporal morphology. TMVs led to more accurate ATs on the septum than EPs. Mesh resolution had a negligible effect on inverse reconstructions, but small distances were important for cross-correlation-based estimation of AT delays.CONCLUSION: LoB artifacts are mainly caused by the inherent spatial smoothing effect of the inverse reconstruction. Among the configurations evaluated, only deflection-based AT estimation in combination with TMVs and strong temporal smoothing can prevent LoB artifacts, while preserving real LoBs.SIGNIFICANCE: Regions of slow conduction are of considerable clinical interest and LoB artifacts observed in non-invasive ATs can lead to misinterpretations. We addressed this problem by identifying factors causing such artifacts and methods to reduce them.

Flapping-wing robots (so-called ornithopters) are a promising type of platform to perform efficient winged flight and interaction with the environment. However, the control of such vehicles is challenging due to their under-actuated morphology to meet lightweight requirements. Consequently, the flight control of flapping-wing robots is predominantly handled by the tail. Most ornithopters feature a tail with two degrees of freedom but the configuration choice is often arbitrary and without in-depth study. In this paper, we propose a thorough analysis of the design and in-flight performance for three tails. Their design and manufacturing methods are presented, with an emphasis on low weight, which is critical in ornithopters. The aerodynamics of the tails is analyzed through CFD simulations and their performance compared experimentally. The advantages and performance metrics of each configuration are discussed based on flight data. Two types of 3D flight tests were carried out: aggressive heading maneuvers and level turns. The results show that an inverted V-tail outperforms the others regarding maneuverability and stability. From the three configurations, only the inverted V-Tail can perform an aggressive stable banked level turn with a radius of 3.7 m at a turning rate of 1.6 rad/s. This research work describes the impact of the tail configuration choice on the performance of bird-scale flapping-wing robots.

Flapping-wing robots (so-called ornithopters) are a promising type of platform to perform efficient winged flight and interaction with the environment. However, the control of such vehicles is challenging due to their under-actuated morphology to meet lightweight requirements. Consequently, the flight control of flapping-wing robots is predominantly handled by the tail. Most ornithopters feature a tail with two degrees of freedom but the configuration choice is often arbitrary and without in-depth study. In this paper, we propose a thorough analysis of the design and in-flight performance for three tails. Their design and manufacturing methods are presented, with an emphasis on low weight, which is critical in ornithopters. The aerodynamics of the tails is analyzed through CFD simulations and their performance compared experimentally. The advantages and performance metrics of each configuration are discussed based on flight data. Two types of 3D flight tests were carried out: aggressive heading maneuvers and level turns. The results show that an inverted V-tail outperforms the others regarding maneuverability and stability. From the three configurations, only the inverted V-Tail can perform an aggressive stable banked level turn with a radius of 3.7 m at a turning rate of 1.6 rad/s. This research work describes the impact of the tail configuration choice on the performance of bird-scale flapping-wing robots.

Healthcare-associated infections (HCAI) is a serious public health problem that results in the death of 8,000-12000 Canadians each year. Besides antibacterial, antifungal, and antiviral therapies, one potential strategy for breaking the chain of HCAI transmission is via the modification of frequently touched surfaces with antibacterial characteristics, called Antibacterial touched surfaces. This is particularly so, given that most pathogenic microbes survive on frequently touched surfaces including doorknobs, over bed tables and countertops, for days, weeks and even months. Thus, frequently touched surfaces can become reservoirs for subsequent direct and indirect cross contamination events. However, problems associated with existing antibacterial coatings such as lack of durability, uncontrolled release of antibacterial agents, lack of standardized testing protocols and antibacterial resistance issues, have necessitated the need for a novel and durable antibacterial surfaces, in addition to appropriate cleaning regime for decontamination of frequently touched surfaces. In this research project, surfaces of AA6061-T6 aluminum alloy (Al-Mg-Si alloy) have been transformed into durable antibacterial surface via four different novel strategies. The first strategy consists of fabrication of superhydrophobic silver-polymethylhydrosiloxane (Ag-PMHS) modified aluminum surface by anodization of aluminum, which provides nano-rough, porous, and stable oxide of aluminum, followed by modification with Ag-PMHS nanocomposites, which delivers a second degree of nanorough patterns from the presence of Ag nanoparticles (Ag-NPs), as well as renders the surface superhydrophobic due to the passivation of low surface energy PMHS. Ag-NPs were used to ensure longevity of antibacterial properties even after eventual possible loss of superhydrophobicity in the long-term. These surfaces presented a bacterial adhesion reduction of 99.0 %, 99.5 %, and 99.3 % for the bacteria of interest, namely

In the present study, controllable microwave sintering was applied to prepare partially stabilised zirconia ceramics with enhanced phase composition and a more uniform structure. To reveal the phase interface properties and structural changes of PSZ ceramics during the microwave sintering process, XRD, FT-IR, Raman, and SEM characterisations were utilised. XRD analysis and Raman analysis demonstrated that the increase of sintering temperature promoted the martensite conversion. However, prolonging duration time was unconducive to the retention of the stable phase. Additionally, the FT-IR characteristic peak movement caused by the reversible phase martensite transformation was observed. Furthermore, SEM analysis found that microwave treatment improved the grain size and structure distribution of the as-received MgO-PSZ sample. This work constructed a controllable technical prototype of preparing PSZ ceramics via microwave sintering, which can provide a theoretical basis and experimental basis for further industrial production.

Flapping-wing robots (so-called ornithopters) are a promising type of platform to perform efficient winged flight and interaction with the environment. However, the control of such vehicles is challenging due to their under-actuated morphology to meet lightweight requirements. Consequently, the flight control of flapping-wing robots is predominantly handled by the tail. Most ornithopters feature a tail with two degrees of freedom but the configuration choice is often arbitrary and without in-depth study. In this paper, we propose a thorough analysis of the design and in-flight performance for three tails. Their design and manufacturing methods are presented, with an emphasis on low weight, which is critical in ornithopters. The aerodynamics of the tails is analyzed through CFD simulations and their performance compared experimentally. The advantages and performance metrics of each configuration are discussed based on flight data. Two types of 3D flight tests were carried out: aggressive heading maneuvers and level turns. The results show that an inverted V-tail outperforms the others regarding maneuverability and stability. From the three configurations, only the inverted V-Tail can perform an aggressive stable banked level turn with a radius of 3.7 m at a turning rate of 1.6 rad/s. This research work describes the impact of the tail configuration choice on the performance of bird-scale flapping-wing robots.

We measure the electrical performance and stability of indium tin zinc oxide (ITZO) thin-film transistors (TFTs), respectively, covered with a passivation layer (PVL) of aluminum oxide (Al2O3) or scandium oxide (Sc2O3) prepared by pulsed laser deposition (PLD). The devices with the Sc2O3 PVL exhibit both satisfactory electrical performance and stability with a field effect mobility of 16.4 cm2/Vs, threshold voltage of 1.0 V, subthreshold swing of 0.09 V/decade, and especially, a minimum threshold voltage shift of 0.7 and-1.6 V under negative bias temperature stress (NBTS) and positive bias temperature stress (PBTS), respectively. This may be attributable to the suppression of oxygen vacancy formation and excellent capacity to protect the channel from environmental effects. Although the devices with the Al2O3 PVL show similar electrical performance, their stability is worse than that of the devices with Sc2O3. This shows the excellent potential of Sc2O3 thin films as a PVL. © 2021 IEEE

With a goal of delay and power reduction in global buses, an air-gap technology for upper-layer interconnect is introduced. The fabrication process is discussed, utilizing h-BN as an air-gap capping layer to enable large voids. The suitability of an air-gap technology for integration into the upper-layer back-end-of-line (BEOL) interconnect is evaluated in terms of the void ratio to the adjacent-line spacing. Electrical measurements show that adjacent-line capacitance is reduced by 50%. Mechanical reliability is ensured by Young's modulus above BEOL requirement. Moisture uptake into air gaps is prevented using a hydrophobic capping layer. The integration of air gaps in global buses results in a 41% and 60% reduction in delay and crosstalk in the worst case switching scenario, based on parameters in the 14-nm technology node. It allows a 72% reduction in the energy-delay product with optimally designed repeaters. For the same delay, power consumption in an air-gapped global bus is reduced by requiring 4x fewer repeaters.

The sol-gel synthesis process is a versatile method used to produce a wide diversity of materials and is being increasingly used as a surface modification method to alter porosity, wettability, catalytic activity, biocompatibility and corrosion performance of underlying substrates. Silane sol–gel films deposited on aluminium and aluminium alloys have been widely studied as chemical conversion coatings and as coupling agent between the substrate and organic layers. This study set out to investigate the effect of the surface chemical treatment prior to sol-gel application on the interfacial adhesion properties of a hybrid sol-gel film. Different surface pre-treatments, including two abrasive treatments and three chemical surface pre-treatments were used and their effect on surface chemistry and surface roughness was assessed. Surfaces were characterized by scanning electron microscopy, x-ray photoelectron spectroscopy, roughness measurements and static contact angles. Cerium nitrate loaded hybrid sol-gel films were deposited and adhesion on commercially pure aluminium was evaluated using pull-off testing. Statistical analysis revealed that, although highest adhesion values were obtained on rougher surfaces, the strongest correlation exists between the surface hydroxyl fraction and adhesion strength., Team Arjan Mol, Team Yaiza Gonzalez Garcia

Surface morphology of adherends is an important factor to take into consideration when studying and improving the performance of an adhesive bonded joint. In this study, the adhesion performance three different surface morphologies of Selective Laser Melted (SLM) Ti6Al4V was studied. The three surface morphologies were created by manufacturing the adherends with different build directions (0, 45 and 90°). Scanning electron microscopy and laser confocal microscopy were used to assess the obtained morphology and roughness of the printed surface areas to be bonded. Those surfaces were subjected to 40 min of UV/Ozone treatment to remove organic contamination traces on the surface which lead to a reduced apparent contact angle and improved adhesive strength. The samples printed at 45°, which showed the highest surface roughness, presented the best adhesive performance during the tensile tests. The addition of sol-gel AC-120 and corrosion inhibition water-based primer BR 6747-1 showed an effective improvement in aging behaviour after 6 weeks of salt spray exposure., Structural Integrity & Composites, Adhesion Institute

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools.

Flapping-wing robots (so-called ornithopters) are a promising type of platform to perform efficient winged flight and interaction with the environment. However, the control of such vehicles is challenging due to their under-actuated morphology to meet lightweight requirements. Consequently, the flight control of flapping-wing robots is predominantly handled by the tail. Most ornithopters feature a tail with two degrees of freedom but the configuration choice is often arbitrary and without in-depth study. In this paper, we propose a thorough analysis of the design and in-flight performance for three tails. Their design and manufacturing methods are presented, with an emphasis on low weight, which is critical in ornithopters. The aerodynamics of the tails is analyzed through CFD simulations and their performance compared experimentally. The advantages and performance metrics of each configuration are discussed based on flight data. Two types of 3D flight tests were carried out: aggressive heading maneuvers and level turns. The results show that an inverted V-tail outperforms the others regarding maneuverability and stability. From the three configurations, only the inverted V-Tail can perform an aggressive stable banked level turn with a radius of 3.7 m at a turning rate of 1.6 rad/s. This research work describes the impact of the tail configuration choice on the performance of bird-scale flapping-wing robots.

Flapping-wing robots (so-called ornithopters) are a promising type of platform to perform efficient winged flight and interaction with the environment. However, the control of such vehicles is challenging due to their under-actuated morphology to meet lightweight requirements. Consequently, the flight control of flapping-wing robots is predominantly handled by the tail. Most ornithopters feature a tail with two degrees of freedom but the configuration choice is often arbitrary and without in-depth study. In this paper, we propose a thorough analysis of the design and in-flight performance for three tails. Their design and manufacturing methods are presented, with an emphasis on low weight, which is critical in ornithopters. The aerodynamics of the tails is analyzed through CFD simulations and their performance compared experimentally. The advantages and performance metrics of each configuration are discussed based on flight data. Two types of 3D flight tests were carried out: aggressive heading maneuvers and level turns. The results show that an inverted V-tail outperforms the others regarding maneuverability and stability. From the three configurations, only the inverted V-Tail can perform an aggressive stable banked level turn with a radius of 3.7 m at a turning rate of 1.6 rad/s. This research work describes the impact of the tail configuration choice on the performance of bird-scale flapping-wing robots.

We measure the electrical performance and stability of indium tin zinc oxide (ITZO) thin-film transistors (TFTs), respectively, covered with a passivation layer (PVL) of aluminum oxide (Al₂O₃) or scandium oxide (Sc₂O₃) prepared by pulsed laser deposition (PLD). The devices with the Sc₂O₃ PVL exhibit both satisfactory electrical performance and stability with a field effect mobility of 16.4 cm²/Vs, threshold voltage of 1.0 V, subthreshold swing of 0.09 V/decade, and especially, a minimum threshold voltage shift of 0.7 and -1.6 V under negative bias temperature stress (NBTS) and positive bias temperature stress (PBTS), respectively. This may be attributable to the suppression of oxygen vacancy formation and excellent capacity to protect the channel from environmental effects. Although the devices with the Al₂O₃ PVL show similar electrical performance, their stability is worse than that of the devices with Sc₂O₃. This shows the excellent potential of Sc₂O₃ thin films as a PVL. IEEE

Potholes are one of the most common forms of road damage, which can severely affect driving comfort, road safety, and vehicle condition. Pothole detection is typically performed by either structural engineers or certified inspectors. However, this task is not only hazardous for the personnel but also extremely time consuming. This article presents an efficient pothole detection algorithm based on road disparity map estimation and segmentation. We first incorporate the stereo rig roll angle into shifting distance calculation to generalize perspective transformation. The road disparities are then efficiently estimated using semiglobal matching. A disparity map transformation algorithm is then performed to better distinguish the damaged road areas. Subsequently, we utilize simple linear iterative clustering to group the transformed disparities into a collection of superpixels. The potholes are finally detected by finding the superpixels, whose intensities are lower than an adaptively determined threshold. The proposed algorithm is implemented on an NVIDIA RTX 2080 Ti GPU in CUDA. The experimental results demonstrate that our proposed road pothole detection algorithm achieves state-of-the-art accuracy and efficiency. IEEE

The sol-gel synthesis process is a versatile method used to produce a wide diversity of materials and is being increasingly used as a surface modification method to alter porosity, wettability, catalytic activity, biocompatibility and corrosion performance of underlying substrates. Silane sol–gel films deposited on aluminium and aluminium alloys have been widely studied as chemical conversion coatings and as coupling agent between the substrate and organic layers. This study set out to investigate the effect of the surface chemical treatment prior to sol-gel application on the interfacial adhesion properties of a hybrid sol-gel film. Different surface pre-treatments, including two abrasive treatments and three chemical surface pre-treatments were used and their effect on surface chemistry and surface roughness was assessed. Surfaces were characterized by scanning electron microscopy, x-ray photoelectron spectroscopy, roughness measurements and static contact angles. Cerium nitrate loaded hybrid sol-gel films were deposited and adhesion on commercially pure aluminium was evaluated using pull-off testing. Statistical analysis revealed that, although highest adhesion values were obtained on rougher surfaces, the strongest correlation exists between the surface hydroxyl fraction and adhesion strength., Team Arjan Mol, Team Yaiza Gonzalez Garcia

Роботу виконано на 81 сторінці, вона містить 3 розділи, 32 ілюстрації, 3 таблиці, і 28 джерел в переліку посилань. Об’єктом дослідження є мікрорельєфна морфологія поверхні напівпровідників. Предметом дослідження є оптичні і фотоелектричні характеристики анізотропно труєної поверхні напівпровідників. Метою роботи є аналіз мікроморфології поверхні напівпровідників для вивчення її впливу на оптичні характеристики. У першому розділі були вивчені основні положення формування мікрорельєфу напівпровідників IV групи і сполук AIII BV за допомогою анізотропного травлення. У другому розділі розглянуто оптичні характеристики мікрорельєфу анізотропно труєних поверхонь. У третьому розділі досліджено характеристики фотопровідності напівпровідників з мікрорельєфною поверхнею., The work is done on 81 pages, it contains 3 sections, 32 illustrations, 3 tables, and 28 references in the list of references. The object of research is the moth-eye morphology of the semiconductor surface. The subject of research is the optical and photoelectric properties of anisotropically etched semiconductor surfaces. The aim of this work is to analyze the micromorphology of the semiconductor surface to study its effect on optical characteristics. In the first chapter, the main provisions of the formation of the microrelief of group IV semiconductors and AIII BV compounds using anisotropic etching were studied. In the second section, the optical characteristics of the microrelief of anisotropically etched surfaces are considered. In the third section, the characteristics of the photoconductivity of semiconductors with a moth-eye surface are investigated.

Познавање површинске структуре вишекомпонентних II–VI полупроводника и утицаја дуготрајног излагања ваздуху на њу значајно је у технолошком и научном смислу. Резултати добијени у овом раду омогућавају боље разумевање процеса на површини испитиваних система (оксидација, сегрегација и миграција елемената), који су уско повезани са њиховим површинским својствима. Метода фотоелектронске спектроскопије рендгенским зрачењем (XPS) је указала на различит састав испитиваних површина, одступање од стехиометријског састава, али и неуниформност састава по дубини узорака на бази CdTe и ZnTe. Због слабо израженог хемијског помераја линија Cd и Zn у XPS спектру, за одређивање хемијских веза које ови елементи граде, у Тези је успешно примењен нови приступ за моделовање Ожеових линија. Одступање од стехиометријског састава може бити последица површинске морфологије, те је овај утицај детаљно размотрен, али је пре свега последица неуниформности састава испитиваних површина по дубини. Површинске концентрације елемената добијене рутинским приступом квантитативној анализи XPS резултата (коришћењем фактора осетљивости) послужиле су за праћење њихове међузависности и једноставну процену површинског састава, а показано је и да постоји компетиција процеса оксидације и адсорпције угљоводоника на површини. Ипак, да би се одредио састав специфичне површинске структуре узорака, која није униформна по дубини те примена фактора осетљивости није могућа, у оквиру ове Тезе је развијен модел који полази од „првих принципа“. Применом модела, уз сазнања која је пружила опсежна анализа XPS и Ожеових спектара, утврђен је тачан састав узорака. Одређене су хемијске фазе присутне у свакој од уочене три површинске области – запреминска област, оксидни слој и слој нечистоћа, и процењена је дебљина површинских слојева узорака., Understanding of the multicomponent II–VI semiconductors surface structure and influence of long term air exposure on it, is a very important question in both, scientific and technological manner. Results presented in this dissertation offers better insight into surface processes of investigated systems (oxydation, segregation and migration of elements), which are closely related to their surface properties. X–ray photoelectron spectroscopy (XPS) reveals different surface structures, variations in stoichiometry and in–depth non–uniform structure of examined samples based on CdTe and ZnTe. Due to poor chemical peak shifts of Cd and Zn lines in XPS spectrum, for chemical bond identification of these elements, the new approach for modeling Auger lines was successfully applied here. Deviation from stoichiometry composition can be a consequence of surface morphology and this influence was considered in detail, but is certainly attributed to non–uniform structure of surfaces in depth. Relative concentrations of elements detected at the surfaces of investigated samples obtained using standard quantitative analysis approach in XPS (using atomic sensitivity factors) served to monitor their correlation and evaluation of surface structure. Furthermore, competiton of two surface processes, oxydation and hydrocarbons adsorption, is established. The model based on first principles is developed in this dissertation, in order to determine the specific surface structure of samples, where using of atomic sensitivity factors is not possible. Application of this model, followed by additional results provided by XPS and Auger spectrum analysis, enables determination of exact in–depth sample structures. Chemical bonds present in each of the three surface areas – bulk, oxide and contamination layer, were determined. Samples surface layers thicknesses were also evaluated.

Surface morphology of adherends is an important factor to take into consideration when studying and improving the performance of an adhesive bonded joint. In this study, the adhesion performance three different surface morphologies of Selective Laser Melted (SLM) Ti6Al4V was studied. The three surface morphologies were created by manufacturing the adherends with different build directions (0, 45 and 90°). Scanning electron microscopy and laser confocal microscopy were used to assess the obtained morphology and roughness of the printed surface areas to be bonded. Those surfaces were subjected to 40 min of UV/Ozone treatment to remove organic contamination traces on the surface which lead to a reduced apparent contact angle and improved adhesive strength. The samples printed at 45°, which showed the highest surface roughness, presented the best adhesive performance during the tensile tests. The addition of sol-gel AC-120 and corrosion inhibition water-based primer BR 6747-1 showed an effective improvement in aging behaviour after 6 weeks of salt spray exposure., Structural Integrity & Composites, Adhesion Institute

Potholes are one of the most common forms of road damage, which can severely affect driving comfort, road safety, and vehicle condition. Pothole detection is typically performed by either structural engineers or certified inspectors. However, this task is not only hazardous for the personnel but also extremely time consuming. This article presents an efficient pothole detection algorithm based on road disparity map estimation and segmentation. We first incorporate the stereo rig roll angle into shifting distance calculation to generalize perspective transformation. The road disparities are then efficiently estimated using semiglobal matching. A disparity map transformation algorithm is then performed to better distinguish the damaged road areas. Subsequently, we utilize simple linear iterative clustering to group the transformed disparities into a collection of superpixels. The potholes are finally detected by finding the superpixels, whose intensities are lower than an adaptively determined threshold. The proposed algorithm is implemented on an NVIDIA RTX 2080 Ti GPU in CUDA. The experimental results demonstrate that our proposed road pothole detection algorithm achieves state-of-the-art accuracy and efficiency. IEEE

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools.

Membrane electrode assemblies are developed by incorporating gas diffusion layers (GDL) to improve the lower and higher relative humidity performance of proton exchange membrane fuel cells (PEMFCs). In the present study, gas diffusion layer samples containing microporous layers, are fabricated using carbon paper substrate, PUREBLACK® carbon powder and polyethylene glycol as pore forming agent. The GDLs are studied in single cell fuel cell, to evaluate the effect of porosity of the micro-porous layer on the performance at different operating relative humidity conditions and compared with commercial GDLs. Scanning electron microscopy and contact angle measurements indicate crack-free surface morphology and hydrophobic characteristics of the PUREBLACK® based GDLs, respectively. By varying the wt. % of PEG, fuel cell performance is evaluated under relative humidity conditions of 60 and 100% using H2/O2 and H2/Air at 70 °C and the durability is also evaluated for the GDL samples without and with 30% PEG. The fuel cell performance of the GDL with 30% pore forming agent (with a pore volume of 1.72 cc.g−1) exhibited higher performance (444 and 432 mW cm−2 at 60 and 100% RH conditions, respectively using H2 and air) compared to that without pore forming agent (436 and 397 mW cm−2)., QC 20210319

A kind of energy crops (Arundo donax) was selected to investigate effects of pyrolysis heating rate (PHR) on char structure and CO2 gasification reactivity. The gasification reactivity and microstructure of char obtained at various PHR were explored. Besides, the surface morphology, microcrystalline and aromatic structure of bio-chars were analyzed via scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. The results reveal that the main thermal decomposition of Arundo donax occurs in the range of 180 °C - 570 °C. The surface of chars obtained at rapid pyrolysis appears to be rougher than that under slow pyrolysis. Rapid pyrolysis results in high temperature gradient inside and outside the particles, leading to condensation of free radical fragments in a short time. The bio-char obtained at rapid heating rate has more structural defects and imperfections of the carbon crystallites. Besides, the crystallization size, graphitization and aromatization degree decrease of bio-char were inhibited as the PHR increased. In addition, some H2O-soluble K was volatilized with the increase of heating rate, and a small part was converted to NH4Ac-soluble K during pyrolysis. Therefore, the gasification reactivity of chars obtained from rapid pyrolysis rate was higher than that from the low pyrolysis rate, which was associated with the formation of alkali metal distribution and micro-areas structure evolution in the bio-chars., QC 20210319

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools., QC 20210301

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools.

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools.

This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools.