High-Resolution Acoustic ILI: Introducing Triple-Threat Detection and Sizing in a Single Pass

Faster joins, self-joins and multi-way joins using join indices

Introduction: Successful and fast reperfusion with endovascular thrombectomy (EVT) improves outcomes in acute ischemic strokes due to large vessel occlusion (LVO). While complete reperfusion (mTICI 3) is the ideal target, multiple passes could prolong EVT and increase complications likelihood without improving clinical outcomes. We hypothesized that pts with a single pass mTICI2b would have similar good outcomes to those with multiple passes mTICI3 with a better safety profile. Methods: From the prospective multicenter cohort study of imaging selection (SELECT), EVT pts who achieved mTICI2b and mTICI3 were stratified into those with single pass vs multiple passes. Functional independence rates at 90 day mRS and safety (sICH, neuro-worsening and mortality) were compared between pts with single pass mTICI 2b and multiple passes mTICI 3. Results: Of 361 pts enrolled, 285 received EVT, of those 70 (25%) achieved mTICI 2b and 159 (56%) mTICI 3. 89 (31%) achieved mTICI 3 with single pass, 70 (25%) with multiple passes, 33 (12%) had mTICI 2b with a single pass and 37 (13%) with multiple passes. Baseline characteristics were similar between the two groups except for larger perfusion deficit (Tmax >6s) volume in pts with multiple passes mTICI3 55 (25, 99) cc vs first pass mTICI 2b 43 (4, 79), p=0.047). Functional independence rates were higher with single pass mTICI 2b as compared to multiple passes mTICI 3 (70% vs 56%, aOR=1.51, 95% CI=0.48-4.76, p=0.78), fig 1 but did not reach statistical significance. Multiple passes mTICI 3 was associated with numerically higher mortality (13% vs 3%, p=0.16) and Neuro-worsening (13% vs 3%, p=0.16) with similar sICH: 4% vs 3%, p=1.00 rates. Conclusion: Complete reperfusion with multiple passes did not confer better outcome rates than single pass mTICI 2b and was associated with worse safety profiles. These results suggest that in the absence of complete reperfusion on first attempt, a single pass mTICI 2b may be sufficient for a successful thrombectomy.

This study focuses on the effect of single pass (SP), double sided pass (DSP) and normal double pass (NDP) method on friction stir welding of aluminum AA6061. Two pieces of AA6061 alloy with thickness of 6 mm were friction stir welded by using conventional milling machine. The rotational speeds that were used in this study were 800 rpm, 1000 rpm and 1200 rpm, respectively. The welding speed is fixed to 100 mm/min. Microstructure observation of welded area was studied by using optical microscope. Tensile test and Vickers hardness test were used to evaluate the mechanical properties of this specimen. Mechanical property analysis results indicate that at low rotational speeds, defects such as surface lack of fill and tunneling in the welded area can be observed. Vickers hardness of specimens however did not vary much when rotational speed is varied. Welded specimens using single pass method shows higher tensile strength and hardness value compared to both double pass methods up to 180.61 MPa. Moreover, DSP showed better tensile test and hardness test compared to NDP method. The optimum parameters were found to be single pass method with 1200 rpm of rotational speed. Therefore economically sound to only perform SP method to obtain maximum tensile strength for AA6061 FSW with thickness of 6 mm.

Metallization of interdigitated back contacts for Si-based solar cells (IBC), where both the n- and p-contacts are processed on the rear side of the device, currently requires costly and labor-intensive masking, photolithography, and/or screen printing approaches, which are difficult for scale-up to high-throughput high-volume manufacturing. Electrodeposition (ED) offers a low cost, scalable, and selective approach for IBC metallization, but is potentially complicated by the close geometry of the contacts and the need for simultaneous plating to both contacts to achieve high processing throughput. Direct laser patterning of a thin seed metal film offers a fast single-step process for defining contact areas, reducing both device handling and chemical use, and allows simple variation of contact design to implement external electrical connections for ED, as well as rapid testing of alternative pattern dimensions and the subsequent effects on device performance. A simple and flexible direct laser scribing approach for processing of IBCs through patterning of thin Ni seed layers prior to Cu electroplating will be presented.IBC patterns were laser-scribed on blanket evaporated Ni seed layers on a-SiNx:H-coated textured-Si wafers (Ni/a-SiNx:H/Si) prior to plating. Patterning was carried out at optimum laser powers to achieve electrical isolation of the Ni contacts. Pattern designs, with 12 mm long n- and p-fingers of 400 and 1200 µm in width, respectively, were fabricated to include tabs for external contacting for ED (Fig. 1a). Contact patterns were prepared using either double-pass-focused or single-pass-defocused laser conditions during ablation. Samples processed with either single (Fig. 1b) or double (Fig. 1c) laser passes show well-defined ~100 µm cuts, however, those patterned with the latter condition showed a ~20 µm laser-induced trench along the center of all scribe lines, due to overlap of the beam paths, and which was not observed for patterns processed with a single pass. Plating conditions from acidified CuSO4-based baths were optimized for deposit reproducibility, uniformity, and adhesion on substrates of non-patterned thin evaporated Ni seed layers on 150 µm textured-Si wafers. Films of growth rate ~0.1 µm/min were achieved, with contact resistance (RC) ~5 mΩ.cm2, and excellent adhesion, enduring pull tests of >5 N where the Si wafer broke before any peeling of the Cu layer.With plating to laser-patterned IBC substrates, significant Cu features grow from the edges of the laser cuts (Fig. 1d), eventually shorting the fingers and leading to unwanted deposition outside of the contact areas. Shorting was not observed with plating to IBC Ni seed patterns that had been evaporated through a shadow mask, suggesting residual conductive phases in the scribes are responsible for the growth of the shorts. Brief chemical etches were carried out after scribing to remove residues and, following Cu plating, etched samples showed attenuated growths into the laser scribes with the contacts remaining electrically isolated. However, for single laser pass samples, ~40 µm wide parasitically-plated Cu stripes (Fig. 1e) were observed along the center of the laser cuts throughout the scribed pattern. Energy-dispersive x-ray spectroscopy (EDS) mapping confirmed the stripe consists of discrete Cu islands, isolated from the growing layer, that eventually coalesce during plating (Fig. 1f). This Cu-stripe feature was not observed for double laser pass samples, indicating differences in properties of the scribes with the different laser patterning conditions.The formation of the Cu-stripe is postulated to be the result of laser ablation and chemical etch damage to the insulating a-SiNx:H layer that opens pinholes to the more conductive c-Si wafer (Fig. 1g). These higher conductivity points produce localized conduits of enhanced current density, sufficient to nucleate Cu, and allow subsequent rapid growth of islands. In contrast, with plating to double pass processed samples, the more extensive laser damage to the a-SiNx:H layer exposes a significantly larger area of the Si wafer, which results in lower current densities insufficient to nucleate Cu. These observed effects of damage to both underlying layers and to growth habits of subsequent films, highlight the need for careful optimization and control of laser conditions during fabrication of photovoltaic devices.Front-junction Si-based solar cells with Al back contacts were etched and re-contacted with ED Cu to IBC-patterned Ni seed layers that had been evaporated through a shadow mask. Device performance showed little change, maintaining ~18% efficiency, with decreased device series resistance through improved RC. These results confirm ED Cu as a feasible and industrially-relevant approach for processing high quality metal contacts for Si-based solar cells. Figure 1

Carbon monoxide (CO) inhalation is the leading cause of poison-related deaths in the United States. CO binds to hemoglobin (Hb), displaces oxygen, and reduces oxygen delivery to tissues. The optimal treatment for CO poisoning in patients with normal lung function is the administration of hyperbaric oxygen (HBO). However, hyperbaric chambers are only available in medical centers with specialized equipment, resulting in delayed therapy. Visible light dissociates CO from Hb with minimal effect on oxygen binding. In a previous study, we combined a membrane oxygenator with phototherapy at 623 nm to produce a "mini" photo-ECMO (extracorporeal membrane oxygenation) device, which improved CO elimination and survival in CO-poisoned rats. The objective of this study was to develop a larger photo-ECMO device ("maxi" photo-ECMO) and to test its ability to remove CO from a porcine model of CO poisoning. The "maxi" photo-ECMO device and the photo-ECMO system (six maxi photo-ECMO devices assembled in parallel), were tested in an in vitro circuit of CO poisoning. To assess the ability of the photo-ECMO device and the photo-ECMO system to remove CO from CO-poisoned blood in vitro, the half-life of COHb (COHb-t1/2 ), as well as the percent COHb reduction in a single blood pass through the device, were assessed. In the in vivo studies, we assessed the COHb-t1/2 in a CO-poisoned pig under three conditions: (1) While the pig breathed 100% oxygen through the endotracheal tube; (2) while the pig was connected to the photo-ECMO system with no light exposure; and (3) while the pig was connected to the photo-ECMO system, which was exposed to red light. The photo-ECMO device was able to fully oxygenate the blood after a single pass through the device. Compared to ventilation with 100% oxygen alone, illumination with red light together with 100% oxygen was twice as efficient in removing CO from blood. Changes in gas flow rates did not alter CO elimination in one pass through the device. Increases in irradiance up to 214 mW/cm2 were associated with an increased rate of CO elimination. The photo-ECMO device was effective over a range of blood flow rates and with higher blood flow rates, more CO was eliminated. A photo-ECMO system composed of six photo-ECMO devices removed CO faster from CO-poisoned blood than a single photo-ECMO device. In a CO-poisoned pig, the photo-ECMO system increased the rate of CO elimination without significantly increasing the animal's body temperature or causing hemodynamic instability. In this study, we developed a photo-ECMO system and demonstrated its ability to remove CO from CO-poisoned 45-kg pigs. Technical modifications of the photo-ECMO system, including the development of a compact, portable device, will permit treatment of patients with CO poisoning at the scene of their poisoning, during transit to a local emergency room, and in hospitals that lack HBO facilities.

The enclosed laser ablation of multiple stacks of laminated, metallised polymer

Single pass and double-pass friction stir processing was carried out on commercially pure aluminium at a rotation speed of 640 rpm and traverse speed of 150 mm/min and a detailed electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) analysis was carried out to understand the microstructure developed. The grain size was refined substantially after the first pass whereas there was no significant change in the grain size after the second pass. This indicates that the final grain size after friction stir processing does not depend on the starting grain size. The equiaxed fine grains were formed by dynamic recrystallization process as revealed by EBSD analysis. TEM observations showed banded contrast across the grain boundaries indicating grain boundaries to be in equilibrium. Free dislocations observed inside grains after the first pass were well arranged into subgrain boundaries after the second pass. EBSD also revealed some variation in microstructural features such as grain size, texture index, grain orientation spread and grain average misorientation across the surface and also in the cross section of the stir zone both after single and double pass.

This paper presents the preliminary results of experiments designed to mimic typical machining and thermal processing practices for aerospace titanium alloys. The most significant finding is that multiple side mill passes result in lower magnitude compressive stresses than a single side pass, which suggests that successive interactions with the milling tool serves to relieve residual stresses at the surface. The most likely mechanism for this is that Ti exhibits significant springback during machining, and multiple tool passes essentially remove the “springback” layer. Each successive removal of material allows stress relaxation in the remaining surface layer. By contrast, with only a single pass, surface residual stresses did not sufficiently relax.

Welding is the most commonly used and one of the most important material-joining processes widely used in industries. Low carbon steel plates with thickness 8 mm and above with 45° V and 60° V single pass and multipass weld geometry are widely used in fabrication of pressure vessels and other components. The residual stress developed due to welding is largely depends on the distribution of heat in weldment. In present work, experimental work has been carried out to find out the temperature distribution during welding of the above weld geometry with single pass and double pass welding on 8 mm thick plates. Non-linear transient thermal analysis has been also performed using commercially available finite element code ANSYS. ‘Tsai’ model is used for modeling heat input in ANSYS. Temperature curves obtained from analysis have been validated with experimental temperature data. The temperature distribution curves obtained from experiments and from numerical simulations are presented in the study. This temperature data can be used as an input for residual stress calculation in any Finite Element Analysis software like ANSYS, ABAQUS and SYSWELD etc. Also from this data, the better weld geometry can be selected for same amount of heat input and thickness.

Fluoride removal from waters by Donnan dialysis

The main paradigm for clustering evolving data streams in the last 10 years has been to divide the clustering process into an online phase that computes and stores detailed statistics about the data in micro-clusters and an offline phase that queries micro-cluster statistics and returns desired clustering structures. The argument for two-phase algorithms is that they support evolving data streams and temporal multi-scale analysis, which single pass algorithms do not. In this paper, we describe a single pass fully online trellis-based algorithm, named ClusTrel, designed for centroid-based clustering that supports evolving data streams and generates clustering structures right after a new point is processed. The performance of ClusTrel is assessed and compared to state of the art algorithms for clustering of data streams showing similar performance with smaller memory footprint.

Experiments are described which demonstrate the feasibility of degrading antimisting kerosene (AMK) in a single pass with a system consisting of an axial piston pump from a TF30 engine and a needle valve The per formance of the degraded AMK was evaluated with full scale aircraft filters (JT8D and CF6), a T63 combustor and laboratory scale tests for filtration and mist ignition At room temperature and higher it was found that AMK could be degraded to perform like Jet A in a single pass with modest power expenditure However, at low temperatures the power requirement increases substantially

Stainless steel is a widely used material in various industries such as aerospace, chemical processing and transportation. Tungsten Inert Gas (TIG) or Gas Tungsten Arc Welding (GTAW) process is extensively used for joining thin sections of stainless steel. However, it is not useful in joining thick sections in a single pass. Activated TIG (A-TIG) significantly increases weld penetration up to 1.5– 4 times in a single pass. Because of its deep penetration ability, A-TIG is the focus of research amongst the researchers. This article reports the mechanisms associated with A-TIG, effects of various weld parameters on weld bead geometry and optimization techniques to optimize the process variable of the A-TIG welding process. The present work also analyzes the consequence of activated fluxes on microstructure and mechanical properties of A-TIG weld metal. Along with this, recent developments in the TIG welding process have been discussed. The study concludes that the A-TIG welding process enhances the weld penetration to a great extent, but a high amount of slug gets deposited on the weld surface. This drawback can be overcome by novel variants of the A-TIG welding process such as Flux Bounded TIG (FB-TIG) and Flux Zone TIG (FZ-TIG) welding processes which enhance the future scope of research.

The authors have examined proper welding condition which enclosed good weld beads in terms of welding appearance for full penetration welding. For CO2 laser welding of large output, it is generally known that porosity may occur in the weld bead when a deep penetration welding in single pass is performed in the ambient atmosphere. Welding defects mainly including porosity also occur more frequently with increase of plate thickness even though in the case of using proper welding condition.In order to spread laser welding generally, porosity is one of the most important problems to be solved. It is thought that formation mechanism of porosity is expressed as follows. Bubbles are generated mainly at the bottom of keyhole, which are trapped in molten metal during floating up and remain as porosity in metal.In this context, to reduce welding defects in welded bead, the authors paid attention to the following two conceptions; the first is that long heat input time would enable to delay beginning of molten metal solidification; the second is that molten metal could be fluidified smoothly by changing direction of recoil pressure. The authors adopted use of twin spot condensing system and improvement for the radiation angle of laser to test piece to accomplish these conception. Twin spot welding was the method of welding with two spot lasers which were condensed two laser beams which were divided from an uncondensed laser beam so that heat input increased in spite of decrease of penetration depth. Forehand welding was performed using a method of inclined laser radiation so that molten metal could be fluidified smoothly by changing direction of recoil pressure.In this report, the authors discuss in detail the prevention of welding defects which are generated by mainly porosity for thick plates.The authors have examined proper welding condition which enclosed good weld beads in terms of welding appearance for full penetration welding. For CO2 laser welding of large output, it is generally known that porosity may occur in the weld bead when a deep penetration welding in single pass is performed in the ambient atmosphere. Welding defects mainly including porosity also occur more frequently with increase of plate thickness even though in the case of using proper welding condition.In order to spread laser welding generally, porosity is one of the most important problems to be solved. It is thought that formation mechanism of porosity is expressed as follows. Bubbles are generated mainly at the bottom of keyhole, which are trapped in molten metal during floating up and remain as porosity in metal.In this context, to reduce welding defects in welded bead, the authors paid attention to the following two conceptions; the first is that long heat input time would enable to delay beginning of molten metal ...

Homogeneous high aspect ratio cellulose nanofibrils (CNFs) were prepared from Laminaria hyperborea (LH) seaweed cellulose without any initial mechanical, biological or chemical pre-treatments. Fourier-transform infrared spectrophotometry revealed that LH cellulose was of the cellulose Iα allomorph, typical of algal cellulose. Compared with wood derived CNF, significant enhancements in crystallinity, viscoelastic properties, water retention values (WRV) and morphological characteristics were identified with a single pass at 1 wt. % cellulose content through a high-pressure homogeniser. Further mechanical fibrillation did not lead to appreciable improvements in material properties that would justify the added energy consumption, which at a single pass is at least a factor of 10 lower than with wood cellulose processing. Good quality CNFs with little compromise in material properties were also obtainable at 2–3 wt. % cellulose contents as identified from viscoelastic analysis, WRV and morphological analysis. LHCNFs also showed good thermal stability, which in summary presents a multifunctional high value cellulose nanomaterial that can find application in various fields.Graphic abstract