Line Groove Research Articles

Мицелна съвместимост на изолати от Phomopsis helianthi (Munt.- Cvet. еt al.)

In the present study, the genetic diversity of 30 isolates of the pathogen Phomopsis helianthi was studied using the mycelial compatibility groups (MCGs) method. Mycelial compatibility tests were carried out on two media - PDA + 80 µl/L and PSA +80 µl/L, with added colorant (Christmas red - Sly Commerce OOD) and without added colorant. The use of PDA medium was found to be inadvisable due to the indistinct dividing line (groove) in isolates having an incompatible phenotypic response. Based on the tests done, 416 combinations were carried out and the four types of reaction were observed- NC-N – incompatible with necrosis, NC-Gincompatible, mycelium do not approach with a pronounced distance between them, NC-DL- both lines (black) are spaced, C-compatible. Their percentage ratio is presented. Isolates are grouped into 20 MCGs, with two of the groups containing only one isolate due to their incompatibility. The remaining isolates were found to occur in more than one MCG. The isolates originating from the region of Ruse were marked with the greatest genetic diversity, and the isolates from the area of Karnobat with the least.

Relation between triple phase contact line and vapor groove width for enhancing thermal performance of a loop heat pipe evaporator

• The effects of changing vapor groove width of a porous wick and improving wettability of a LHP evaporator on heat transfer performances were evaluated experimentally and theoretically. • The micro-grooves processed on the heating plate improved heat transfer performances regardless of the vapor grooves width. • The micro-grooves increased heat transfer performances more greatly as the vapor grooves width increased. • Numerical model explained that the length of triple phase contact line has a great influence on the evaporative heat transfer coefficient. In this study, the effects of an increased evaporation area known as the triple-phase contact line (TPCL), of the porous wick and improved evaporator wettability on the loop heat pipe (LHP) heat transfer performance were evaluated experimentally and theoretically. An infrared camera and a microscope were used to observe the thermo-fluid behavior of porous wicks with different vapor grooves widths and evaporator heating plates with different inner wall structures in the experiment. The porous wick's vapor groove widths were 1.0 mm, 0.5 mm, and 0.2 mm. A normal heating plate and a micro-grooved heating plate were used as the evaporator case. As a result, it was clarified that processing the micro-grooves on the heating plate improved the evaporative heat transfer coefficient and maximum heat flux, regardless of the vapor grooves width of the porous wick. Furthermore, it was proposed that both of them increased significantly as the vapor grooves width increased. The thermal-hydraulic numerical model that predicted the heat transfer coefficients for each case was developed. The calculation results showed a significant increase in the heat transfer coefficient as the TPCL appearance rate, which expresses how much the TPCL appears in the micro-grooves, increased, and this increasing tendency was in good agreement with the experimental results. Furthermore, it was proposed that the TPCL appearance rate at a high heat flux was reduced as the vapor grooves width decreased. The results indicate a new promising approach for improving the heat transfer performance of LHP evaporators.

Micromachining of polymers using atmospheric pressure inductively coupled helium plasma localized by a scanning nanopipette probe microscope

We developed a local irradiation system for atmospheric pressure inductively coupled plasma (ICP) using a quartz capillary nozzle (nanopipette) with a sub-micrometer diameter tip aperture for fine processing of material surface. Using this system, a polymethyl methacrylate (PMMA) film coated on a glass substrate was etched at the micrometer scale. Fine etching was achieved by the ICP localized by the nanopipette precisely placed near the surface, using the positioning capability of a homemade scanning probe microscope. The locally etched surface of the PMMA film was confirmed by imaging immediately after the etching process by scanning the nanopipette. For quantitative evaluation, the topographical image of the same location of the surface was then acquired using an atomic force microscope. The etching rate of the ICP was 20 times higher than that of the low-frequency atmospheric pressure plasma jet. The depth of the etched holes increased with increasing applied power and irradiation time and decreasing irradiation distance. In addition, line groove patterning with sub-micrometer width was successfully achieved. The proposed system is expected to be used in various applications such as processing and repairing of microdevices.

Understanding the Role of Pattern Geometry on Nanofiltration Threshold Flux.

Colloidal fouling can be mitigated by membrane surface patterning. This contribution identifies the effect of different pattern geometries on fouling behavior. Nanoscale line-and-groove patterns with different feature sizes were applied by thermal embossing on commercial nanofiltration membranes. Threshold flux values of as-received, pressed, and patterned membranes were determined using constant flux, cross-flow filtration experiments. A previously derived combined intermediate pore blocking and cake filtration model was applied to the experimental data to determine threshold flux values. The threshold fluxes of all patterned membranes were higher than the as-received and pressed membranes. The pattern fraction ratio (PFR), defined as the quotient of line width and groove width, was used to analyze the relationship between threshold flux and pattern geometry quantitatively. Experimental work combined with computational fluid dynamics simulations showed that increasing the PFR leads to higher threshold flux. As the PFR increases, the percentage of vortex-forming area within the pattern grooves increases, and vortex-induced shielding increases. This study suggests that the PFR should be higher than 1 to produce patterned membranes with maximal threshold flux values. Knowledge generated in this study can be applied to other feature types to design patterned membranes for improved control over colloidal fouling.

Optimal design of a reflective diffraction grating scale with sine-trapezoidal groove for interferential optical encoders

Interferential optical encoders are promising nano-positioning sensors in precision manufacturing and metrology instrumentation. As measuring standard, the quality of diffraction grating scales primarily determines the performance of the interferential optical encoders. In this work, the optimal design and fabrication of a reflective diffraction grating scale with sine-trapezoidal groove is performed. Firstly, the requirement for diffraction characteristics of diffraction grating scales is specified by introducing the basic principle of interferential optical encoders. Sequentially, the critical requirements of the diffraction grating scales are further specified by theoretically investigating the influence of groove-profile parameters (i.e. line height, groove and ridge widths) and micro-defect parameters (i.e. surface roughness and line roughness) on the diffraction characteristics of diffraction grating scales. Finally, morphological parameter optimization of a diffraction grating scale with a pitch of 4 μm is performed, and the diffraction grating scale is fabricated and characterized. The characterization results indicate that the fabricated diffraction grating scale conforms well to the optimal design, and is ideal for application in interferential optical encoders.

Cutting performance of micro-textured WC/Co tools in the dry cutting of Ti-6Al-4V alloy

To further improve the cutting performance of WC/Co tools in the dry cutting of Ti-6Al-4V alloy. Experiments in dry cutting titanium alloy were carried out using micro-textured YG8 tools under different cutting speeds and depths. Three kinds of YG8 tools with the rake face machined with line groove, sinusoidal groove, and rhombic groove were adopted as the micro-texture YG8 tools. The cutting force, friction coefficient of the tool-chip contact zone, chip morphology, tool wear, and surface quality of machined titanium alloy were analyzed. The results show that the micro-textured tools can effectively reduce the wear area on the rake face and flank face, improve the wear form on the rake face, reduce the occurrence of oxidation wear, and improve the surface quality of machined Ti-6Al-4V alloy. Therefore, micro-textured tools can effectively improve cutting performance and prolong tool life. The existence of micro-texture on the tool surface has a certain influence on the tool performance. The line groove-textured tool has the best effect, followed by the sinusoidal and rhombic groove-textured tools.

Study on the Cutting Performance of Micro Textured Tools on Cutting Ti-6Al-4V Titanium Alloy.

Titanium alloys are widely used in various fields, but their machinability is poor because the chip would easily adhere to the tool surface during cutting, causing poor surface quality and tool wear. To improve the cutting performance of titanium alloy Ti-6Al-4V, experiments were conducted to investigate the effect of micro textured tool on the cutting performances. The cemented carbide tools whose rake faces were machined with line, rhombic, and sinusoidal groove textures with 10% area occupancy rates were adopted as the cutting tools. The effects of cutting depth and cutting speed on feed force and main cutting force were discussed based on experimental results. The results show that the cutting force produced by textured tools is less than that produced by non-textured tools. Under different cutting parameters, the best cutting performance can be obtained by using sinusoidal textured tools among the four types of tools. The wear of micro textured tools is significantly lower than that of non-textured tools, due to a continuous lubrication film between the chip and the rake face of the tool that can be produced because the micro texture can store and replenish lubricant. The surface roughness obtained using the textured tool is better than that using the non-textured tool. The surface roughness Ra can be reduced by 35.89% when using sinusoidal textured tools. This study is helpful for further improving the cutting performance of cemented carbide tools on titanium alloy and prolonging tool life.

Investigation of tribological performance of micro-groove textured cemented carbide surfaces

ABSTRACT Three kinds of grooved textures with different geometric patterns were prepared on cemented carbide tool surfaces. Finite element software FLUENT was used to simulate and analyse the fluid pressure of lubricants on the different micro-groove textured surfaces. Friction and wear experiments of titanium alloy balls and cemented carbides were carried out to investigate the tribological properties. The results show that the friction coefficient of the line groove textured surface is the smallest under dry friction conditions. Moreover, the friction coefficient of the sinusoidal groove textured surface is the smallest under fluid lubricated conditions. Experimental results show that lubrication of the grooved textured surfaces is consistent with the numerical simulation results. The main friction reduction mechanism of textures involves reducing the contact area of friction pairs and capturing debris under unlubricated conditions and supplying lubrication to form a continuous lubrication film and producing a dynamic pressure effect under fluid lubricated conditions.

ENSANCHAMIENTO DE UN SURCO SUPERFICIAL EN HIELO PURO

In this work the evolution of the width of a line (groove) traced on the surface of a sample of bi-crystalline ice, by means of a metallic sheet, in a direction almost orthogonal to the grain edge (BG) was studied. To perform the measurements, the sample of ice submerged in ultrapure silicone oil was maintained at -5 ºC to prevent evaporation from occurring and isolate the effect of surface diffusion in this way. Photographs of the groove were periodically taken, approximately for 100 hours, using a camera coupled to an optical microscope. From these images the evolution of the line width was studied. Finally, the ice self-diffusion coefficient was determined at -5 ºC.

Arrangement of self-assembled ZnO-NiO nanostructures using topographical templates towards oxide directed self-assembly

Self-assembled oxide composite nanostructures offer novel functionalities and three-dimensional architectures, such as vertical pillars and matrix structures. One of the challenges in this field is to precisely control the positional arrangement of oxide pillars embedded in a matrix. Here, we report on an early proof-of-concept demonstration for positioning and arranging self-assembled NiO pillars in a ZnO matrix. SrTiO3 templates with artificial line groove patterns were fabricated by nanoimprint lithography (NIL). High-density NiO pillars were observed on both sides of the template line edges as well as a single array of NiO pillars in the middle of each line groove for a 90 nm line width. This simple technique provides a path towards the development of nanoscale design and applications for memory devices.Self-assembled oxide composite nanostructures offer novel functionalities and three-dimensional architectures, such as vertical pillars and matrix structures. One of the challenges in this field is to precisely control the positional arrangement of oxide pillars embedded in a matrix. Here, we report on an early proof-of-concept demonstration for positioning and arranging self-assembled NiO pillars in a ZnO matrix. SrTiO3 templates with artificial line groove patterns were fabricated by nanoimprint lithography (NIL). High-density NiO pillars were observed on both sides of the template line edges as well as a single array of NiO pillars in the middle of each line groove for a 90 nm line width. This simple technique provides a path towards the development of nanoscale design and applications for memory devices.

ACrassigyrinus-like jaw from the Tournaisian (Early Mississippian) of Scotland

ABSTRACTThe early tetrapodCrassigyrinus scoticuswas a large aquatic predator from the mid Carboniferous (late Viséan or early Serpukovian) of Scotland, around 330 My in age. There are five main specimens with cranial remains: an articulated skeleton; two incomplete skulls; and two lower jaws.Crassigyrinusretains several apparently primitive features of the palatal dentition and lower jaw, and its phylogenetic position is disputed. A partial lower jaw resembling that ofCrassigyrinuswas discovered at Burnmouth in the Borders region of Scotland. The horizon in which it was found is dated as late Tournaisian, CM palynozone, around 350 My in age. Though it lacks dentition, the jaw preserves much of the postsplenial, angular and surangular, whose appearance externally and internally is almost identical to that ofC. scoticus. Internally, the jaw shows a similarly limited extent of the suturing between the splenial series and the prearticular, a primitive condition. Externally, the type and distribution of dermal ornamentation closely matches that ofC. scoticus, as does the deeply excavated and marginally positioned lateral line groove. As well as external and internal features, all specimens ofC. scoticusare of similar skull size, though the Burnmouth jaw is somewhat smaller. If correctly attributable toCrassigyrinus, this specimen extends the existence of the genus by approximately 20 million years towards the base of the Carboniferous.

Atomic force microscope caliper for critical dimension measurements of micro and nanostructures through sidewall scanning

A novel atomic force microscope (AFM) dual-probe caliper for critical dimension (CD) metrology has been developed. The caliper is equipped with two facing tilted optical fiber probes (OFPs) wherein each can be used independently to scan either sidewall of micro and nanostructures. The OFP tip with length up to 500μm (aspect ratio 10:1, apex diameter ⩾10nm) has unique features of scanning deep trenches and imaging sidewalls of relatively high steps with exclusive profiling possibilities. The caliper arms–OFPs can be accurately aligned with a well calibrated opening distance. The line width, line edge roughness, line width roughness, groove width and CD angles can be measured through serial scan of adjacent or opposite sidewalls with each probe. Capabilities of the presented AFM caliper have been validated through experimental CD measurement results of comb microstructures and AFM calibration grating TGZ3.

J2220203 超精密切削加工を利用した金属ナノドットアレイの効率的製造法の検討

Metal nano-dot array, consisting of a glass substrate and metal dots arranged on it, has the property of localized surface plasmon resonance and it's expected to be applied to optical devices or biosensors. For fabrication of such minute structures EBL and FIB are not always suitable due to their high facility cost, low throughput and stringency of processes. In order to fabricate nano-dot array more simply and efficiently, the authors propose its fabrication metod utilizing ultra precision machining. 1 μm-pitch line & space groove pattern and lattice groove pattern are made on a soda glass and quartz glass substrates by ultra precision machining with diamond tool. After gold coating on the substrates and annealing them, gold nano-dots aggregate and their alignments are controlled by the groove pattern.

Effect of Brake Pad Design On Friction and Wear with Hard Particle Present

Brake pad and disc design are important factors in ensuring excellent brake performance. But, particles from the environment can easily enter and interrupt the braking process and reduce braking performance. Friction depends on the design and surface properties of the pad and the disc. Wear happens in the brake system as the pad and disc try to withstand the braking force during the braking process. An experiment using brake dynamometer is done in order to determine the design effects on friction and wear when hard particle are present during the braking process. The test used three different brake pad designs under medium sliding load condition. It is found that Design 2 with a middle line groove provides better and stable brake torque and friction performance compared to Design 1 and Design 3. Design 2 also gavethe smallestweight loss inthe wear analysis of the pad.

The calculation, fabrication and verification of diffraction grating based on laser beam splitters employing a white light scatterometry technique

In this work we present an application of polarized white light transmission and reflection measurements as well as simulation results for the analysis of diffractive optical elements, i.e. two port beam splitters for visible wavelength range lasers. A different pitch of 2, 4μm and a line height of 400–800nm phase diffraction gratings were fabricated in fused quartz substrates employing contact lithography and plasma chemical etching. Line heights of the beam splitters targeted for 405–633nm wavelength lasers were selected according to a straightforward analytical method. The resulting beam splitters were analyzed performing angular polarized white light reflection and transmission spectra measurements illuminating an 0.7cm2 area of the sample. Varying the surface profile in the “PCGrate” and “GSolver” simulation software and comparing the estimated transmission and reflection spectra with the experimental ones we have deduced the actual profiles of the structures. The assessed geometrical parameters of the profile, i.e. line height, groove and ridge widths correspond to the ones obtained when employing scanning electron and atomic force microscopy. The proposed modeling and validation method appeared to be an appropriate tool in the control of production of beam splitters possessing more than 60% diffraction efficiencies.

Experimental Investigation of Mechanical Characteristics of Parallel Polygonal Line Groove Multilayer Winding Drum

The characteristics and mechanism of parallel polygonal line groove multilayer winding drum were investigated by an experimental approach. Strain-electricity method was used to test the stress of the cylinder body and the end plates of the drum. Experimental results show that the distribution of the axial bending stress on cylinder body is symmetric in the radial symmetry section. The largest axial bending stress appears in the symmetry plane; however the minimum stress is in the sections close to the end plates on both sides. The axial bending stress of the cylinder body is found to grow with the number of layers wrapped around the drum increasing, while the increment of the stress decreases. When the layer number of the wire rope increases from 4 to 5, the increment of the stress is less than 3 [MPa].

Role of Actin Cytoskeletal Structure for Cell Migration on Micro-Structured Surfaces

Cell migratory behavior is known to be remarkably affected by the interaction with the surface topography at multiple scales, ranging from nanometers to tens of micrometers. Here, our aim is to clarify the interaction between cells and micrometer scale topography based on the role of actin cytoskeletal structure. We fabricated silicon microstructured surfaces with microgrooves of various sizes, and characterized the behavior of cells moving from the flat surface to the grooved surface. The intersecting grooves with a size that allow a cell to experience multiple grooves absorbed cells with a higher angle of approach, and repelled cells with a lower angle of approach. Similarly, the single line groove showed a tendency to repel cells with a lower angle of approach and absorb cells with a higher angle of approach. However, the tendency with the single line groove was less clear than that with the intersecting grooves. The result indicates that the intersecting grooves had a better discrimination performance of the angle of approach of the cells than a single line groove. The mechanism of this motility-based filtering is supposed to be primarily explained based on the lamellar dragging effect by the preferential lamellar protrusion into the grooves due to the mechanical restriction provided by the actin cytoskeleton. If the lamellar dragging effect is sufficiently high, the cells are absorbed by the grooved surface. In contrast, if the dragging effect is not enough to draw the cell body into the grooves, the cells are repelled by the grooved surface. This study provides a framework to tailor the microgrooved surface control of cell migration by using microgrooves.

A new Placoderm fish (Acanthothoraci) from the Early Devonian Jauf Formation (Saudi Arabia)

An exceptionally well-preserved new acanthothoracid (placoderm fish) presenting complete endocranium and skull roof, from Saudi Arabia (Qasr Limestone Member, Jauf Formation), Early Devonian in age, is described as Arabosteus variabilis n. gen., n. sp. Compared to other Acanthothoraci, the new taxon exhibits a skull roof variable in its dermal plate distribution (e.g., a supernumerary plate: the posterior central plate) and sensory line pattern. Even the different specimens of this taxon show such variability between them. Arabosteus variabilis n. gen., n. sp. enlarges the scope of our knowledge of Acanthothoraci and Placodermi in general. Traditionally, the Arthrodira, one of the historically earliest described groups, provide the standard reference model for the placoderm skull roof pattern. The interpretation of the acanthothoracid skull roof pattern of the Saudi taxon from an arthrodiran model and the establishment of homologies is impossible to resolve unless based on prior assumptions (e.g., hypothesis of fragmentation or fusion for the paranuchal plate complex). The lateral line system of A. variabilis n. gen., n. sp. is unstable (e.g., presence or absence of the postmarginal sensory line canal) making it ambiguous to define bone homology and terminology. Consequently spatial distribution of skull roof plates has been retained for such a task with a minimal reference to the instable features of the sensory line groove distribution.

Robotic Coloanal Anastomosis with or without Intersphincteric Resection for Low Rectal Cancer: Starting with the Perianal Approach Followed by Robotic Procedure

Background Coloanal anastomosis (CAA)/intersphincteric resection (ISR) is a promising method of sphincter-preserving surgery for very low rectal cancer. Recently, a robotic system has been attempted in CAA/ISR. By means of a robotic system, an excellent stereoscopic view may be obtained with high illumination, and adequate traction and countertraction can be easily performed in a narrow pelvis using the Endowrist function. During robotic CAA/ISR, although the robotic system is necessary to perform pelvic dissection that comes before the perianal approach, the huge robotic arms located in the low abdominal region could interfere with comfortable perianal dissection for the surgeon. Therefore, the robotic system has to be withdrawn and then set up again above the patient’s abdomen, which is time-consuming. Moreover, this process also makes it difficult to maintain the aseptic circumstance of the robotic system. To address this problem, it is necessary to change the sequence of the procedure.

Control of highly migratory cells by microstructured surface based on transient change in cell behavior

Cell migration control techniques have been proposed for cells with relatively low migratory activity, based on static analyses performed with cells that attain a temporally homogenous state after being exposed to a cell guiding stimulus. To elucidate new functions of substrate topography, we investigated the transient change in the behavior of highly migratory cells coming from a flat surface to a grooved surface on a silicon substrate covered with SiO 2. A single line groove (1.5 μm in width, 20 μm in depth) and intersecting grooves (1.5 μm in width, 5 μm in spacing, 20 μm in depth) functioned as an effective cell repellent. In the case of wider grooves, a single line groove (4 μm in width; 20 μm in width) had no specified function. In contrast, intersecting grooves (4 μm in width, 5 μm in spacing) functioned as a trap for the cells. Our findings yield a new design concept of cell repelling and trapping surfaces which are applicable to cell guiding methods and single or multiple cell confinement on cell culture substrates, and thus may contribute to development of more advanced biomaterials.