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1
Yamshchikov, O. N., D. A. Markov, S. A. Emelyanov, K. P. Zvereva, and A. E. Bychkov. "Comparative analysis of modeled femoral fractures osteosynthesis stability." Kazan medical journal 95, no. 3 (June 15, 2014): 392–94. http://dx.doi.org/10.17816/kmj1522.
Повний текст джерелаАнотація:
Aim. To perform the comparative analysis of osteosynthesis stability in splintered fractures on the example of modeled fractures of femur with metalwork. Methods. Bone fragments fixation methods using internal fixators, blocking intramedullary nails, external fixation devices. Round wooden rod with external diameter of 35 mm, internal diameter of 25 mm, which was saw in the middle with two cuts directed at an angle of 45° to the rod axis to form the triangle fragment, was picked for femur model for the purpose of experiment. The stability of bone fragments fixation using plates with angle stability, pin- and nail-type external fixation devices and blocking intramedullary nails was assessed. To test the stability of the «bone-fixing device» complex, torsional test machine КМ-50-1 №66, power press П-10 №92, pull test machine Р-10 №1677 were used. Results. Compared to external fixation device, fixation using plates with angle stability was 6 times more stable at axial load and by 43.5% at lateral load. The stability of blocking intramedullary nail at axial load was higher compared to external fixation device. At rotary load, the stability of blocking intramedullary nail was 2 times lower compared to external fixation device. Conclusion. On a model of splintered double-lever femur fractures, fixation using plates with angle stability was the most stable fixation mode.
2
Jana, Sourita, Debasis Samanta, Mir Muhammad Fahad, Sellamuthu N. Jaisankar, and Hongdoo Kim. "Blocking and Deblocking of Diisocyanate to Synthesize Polyurethanes." Polymers 13, no. 17 (August 27, 2021): 2875. http://dx.doi.org/10.3390/polym13172875.
Повний текст джерелаАнотація:
Diisocyanates, particularly toluene diisocyanate (TDI), are useful for the preparation of various polyurethanes with specific applications as leather-like materials, adhesives and insoles, etc. Blocking agents can be used for the operational simplicity and to reduce the hazards of TDI. In this paper, we reported the use of 3-(4-bromo-phenyl)-1H-pyrazole to block toluene diisocyanate (TDI). FTIR, NMR, thermogravimetric analysis, contact angle analysis and differential scanning calorimetry (DSC) were used for the characterization. The effectiveness of the blocking was confirmed by spectroscopic techniques. The DSC thermogram showed that blocked adducts deblock at 240 °C, causing the regeneration of TDI, and causing the diisocyanates to react with polyols of different molecular weights, forming polyurethanes. The characterization of the polyurethanes was performed by infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry and a contact angle study.
3
Ma, Jun, Chenglong Wang, and Yangjun Xia. "Research on Analysis Method of Shading and Blocking of LFR Field." E3S Web of Conferences 118 (2019): 03041. http://dx.doi.org/10.1051/e3sconf/201911803041.
Повний текст джерелаАнотація:
Shading and blocking problem is the main element restricting efficiency of a LFR system. The traditional analysis methods often need to build the models by using SolTrace, which results in the low efficiency. According to characteristics of single axis tracking of the LFR field, a plane right-angle coordinate system was established, and coordinate equations of reflectors at any time were deduced. Lengths of shading and blocking were got by tracking sun rays which fell on the reflectors and reflected the receiver passing through the adjacent reflector endpoints at any time. Offset caused by the solar azimuth in the shading and blocking area was got by geometrical optics. And then, the shading and blocking efficiency could be calculated. For the Puerto Errado 1 solar thermal plant, the shading and blocking efficiencies on vernal equinox hardly changed; on summer solstice, they were smaller at sunrise and sunset, and gradually stable and close to the value of spring equinox with the increase of solar altitude angle; they were smaller on winter solstice and the change with time were larger. The results of the calculations were good agreement with the simulation dates of SolTrace, and validity of the method was proved.
4
Alazwari, Mashhour A., and Mohammad Reza Safaei. "Combination Effect of Baffle Arrangement and Hybrid Nanofluid on Thermal Performance of a Shell and Tube Heat Exchanger Using 3-D Homogeneous Mixture Model." Mathematics 9, no. 8 (April 16, 2021): 881. http://dx.doi.org/10.3390/math9080881.
Повний текст джерелаАнотація:
In this study, thermal performance and flow characteristics of a shell and tube heat exchanger equipped with various baffle angles were studied. The heat exchanger was operated with distilled water, and a hybrid nanofluid at three concentrations of 0.04% and 0.10% of GNP-Ag/water within Reynolds numbers ranged between 10,000 and 20,000. The thermophysical properties of nanofluid varied with temperature and nanoparticles’ concentration. The baffle angles were set at 45°, 90°, 135°, and 180°. Results showed that the calculated Nusselt number (Nu) could be improved by adding nanoparticles to the distilled water or increasing the fluid’s Reynolds number. At a low Re number, the Nu corresponding to baffle angle of 135° was very close to that recorded for the angle of 180°. At Re = 20,000, the Nu number was the highest (by 35% compared to the reference case), belonging to a baffle angle of 135°. Additionally, results related to friction factor and pressure drop showed that more locations with fluid blocking were observed by increasing the baffle angle, resulting in increased pressure drop value and friction. Finally, the temperature streamlines counter showed that the best baffle angle could be 135° in which maximum heat removal and the best thermal performance can be observed.
5
Kojima, Kazutoshi, Sachiko Ito, Junji Senzaki, and Hajime Okumura. "4H-SiC Homoepitaxial Growth on Vicinal-Off Angled Si-Face Substrate." Materials Science Forum 645-648 (April 2010): 99–102. http://dx.doi.org/10.4028/www.scientific.net/msf.645-648.99.
Повний текст джерелаАнотація:
We have carried out detailed investigations of 4H-SiC homoepitaxial growth on vicinal off-angled Si-face substrates. We found that the surface morphology of the substrate just after in-situ H2 etching was also affected by the value of the vicinal-off angle. Growth conditions consisting of a low C/Si ratio and a low growth temperature were effective in suppressing macro step bunching at the grown epilayer surface. We also demonstrated epitaxial growth without step bunching on a 2-inch 4H-SiC Si-face substrate with a vicinal off angle of 0.79o. Ni Schottky barrier diodes fabricated on an as-grown epilayer had a blocking voltage above 1000V and a leakage current of less than 5x10-7A/cm2. We also investigated the propagation of basal plane dislocation from the vicinal off angled substrate into the epitaxial layer.
6
Huang, Bing. "The Value and Application of Personalized Needle Modification in Percutaneous Infrazygomatic Radiofrequency in Isolated Maxillary Nerve Pain through the Foramen Rotundum." Pain Physician 4, no. 22;4 (July 11, 2019): 377–89. http://dx.doi.org/10.36076/ppj/2019.22.377.
Повний текст джерелаАнотація:
Background: Percutaneous infrazygomatic radiofrequency (PIR) is a common approach used to block isolated maxillary nerve (V2) pain through the foramen rotundum (FR) in patients with trigeminal neuralgia (TN). Nevertheless, when using this method, there is a risk of accidental penetration of the superior orbital fissure (SOF) and the optic canal (OC) that may result in the injury of the vessels and nerves in that area, and in some severe cases may lead to blindness. According to the blocking of the external orifice of the FR and whether a curved needle was used, combined angle deviation from the path of percutaneous infrazygomatic approach, the FR to the SOF or the OC in the treatment of V2 pain, in which no research has reported the angle, we analyzed the value and application of personalized needle modification in PIR in isolated maxillary nerve pain through the FR. Objectives: The following study examined the relationship between the FR and the SOF, and analyzed the clinical significance of personalized needle modification in computed tomography (CT)-guided PIR ablation of the maxillary nerve through the FR in patients with TN. Study Design: Randomized, review, clinical research study. Setting: Department of Anesthesiology and Pain Medical Center, Jiaxing, China. Methods: Three-dimensional reconstruction was performed in 88 patients and 136 patients with PIR ablation in isolated maxillary nerve pain through the FR. According to the blocking of the external orifice of the FR and whether a curved needle was used, patients were divided into 4 groups: curvedneedle blocking group (CB), straight-needle blocking group (SB), straight needle no-blocking group (SN), and curved-needle no-blocking group (CN). Results: The results obtained revealed minimum H (shortest diameter of the FR) = 1.0 mm and minimum L (length of the FR tubes) = 3.7 mm. The distance between the external orifice of the FR and the SOF (FS) was 5.16 ± 1.33 mm. The angle A (between the radiofrequency needle and the sagittal plane) was 39 ± 3.95°; the angle between the canthomeatal line and the CT scan line (ACT) was 58.99 ± 6.23°; the puncture depth (LS) was 63.99 ± 4.24 mm; the deviation angle of the misplacement into the SOF (SAF) was 2.96 ± 0.71°; the deviation angle of the misplacement into the OC (OAF) was 4.95 ± 0.73°. In addition, the postoperative Numeric Rating Scale scores in the CB group were significantly lower compared with the SB group, whereas the probability of entering the SOF in the CB group was significantly lower compared with the SB group. The total number of punctures in the SN group was less than that in the CN group. Limitations: Additional clinical data should be collected to preserve the results in future work. Conclusions: The distance between the FR and the SOF or the OC was only few millimeters, and slight angle error could lead to the SOF and the OC. For patients with blockage in the path, the treatment of radiofrequency with personalized needle modification could improve the curative effect and reduce the risk of accidental SOF penetration. Key words: Trigeminal neuralgia, foramen rotundum, superior orbital fissure, radiofrequency, personalized needle modification
7
Wang, Shuo Liang, Yang Ming Liao, and Huang Chang Xie. "Fractured Reservoir Blocking Dosage Calculation Method." Applied Mechanics and Materials 268-270 (December 2012): 772–75. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.772.
Повний текст джерелаАнотація:
Fractured reservoir development process are often faced with the angle wells flooded serious and side wells don’t get the effect of water injection. In order to increase the water flooding sweep efficiency. Profile control plugging is a measure that is frequently used. Traditional plugging program design does not take into account the fluid loss, Program design of the blocking agent dosage is always small, the result is not satisfactory. In this paper, the classic percolation theory is used, seepage equation of the fracture system and matrix system is established, the blocking agent Filtrate analytical solution that considers the different reservoir properties and different blocking agent performance is obtained, that can be used to guide the design of profile control water plugging program and can calculate the best blocking agent dosage. Through the actual implementation of the effect, the proposed method can be more substantial increase in the effect of plugging.
8
Loane, R. F., and J. Silcox. "Hollow-cone illumination in simulated ADF STEM." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 124–25. http://dx.doi.org/10.1017/s0424820100152598.
Повний текст джерелаАнотація:
The overlap regions between CBED disks are a source of lattice fringe contrast in ADF STEM images of crystals. For sufficiently small lattice spacings, the Scherzer focus convergence angle is too small for the CBED disks to overlap, and the lattice is not visible. By increasing the convergence angle beyond the Scherzer angle to create an overlap region, and by using stationary phase defocus, smaller lattices can be imaged However, with larger convergence angles, lens aberrations spread the incident beam and small aperiodic structures, such as adatoms, become difficult to image. If the specimen Bragg angle is known, an annular objective aperture can be designed to pass the overlap regions of the incident beam, while blocking the central, non-overlap region which produces a large constant background. The annular probe size is minimized by choosing an annulus width and defocus which balance the spherical aberration across the annulus (close to stationary phase defocus). Simulations indicate hollow cone illumination may allow both adatoms and smaller lattices to be imaged simultaneously. This approach presumes knowledge of the specimen, and must be used in conjunction with standard methods for correct image interpretation. An incorrectly applied annulus will produce image artifacts.
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Boudghene Stambouli, Arslane, Rafik Benallal, Nourredine Oudini, Sidi Mohamed Mesli, and Rabah Tadjine. "Control of Dual Frequency Capacitively Coupled Plasma via blocking capacitor and phase angle." European Physical Journal Applied Physics 80, no. 1 (October 2017): 10802. http://dx.doi.org/10.1051/epjap/2017170180.
Повний текст джерела
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Oni, Oluwafemi E., Andrew G. Swanson, and Rudiren Pillay Carpanen. "Line Commutated Converter Response during Total and Partial De-Blocking of a Bipolar MTDC System." International Journal of Engineering Research in Africa 52 (January 2021): 49–61. http://dx.doi.org/10.4028/www.scientific.net/jera.52.49.
Повний текст джерелаАнотація:
This paper focuses on the fault blocking analysis and operational issues associated with MTDC systems incorporated in an AC network. The dynamic modelling of a line-commutated converter based bipolar multi-terminal direct current (LCC MTDC) system are shown, and the dynamic response of the converter during a DC converter fault is discussed. The converter controller design for both rectifiers and the inverters system was modelled for a realistic active power and extinction angle (γ) control with consideration to the VI characteristics of all the converter stations. An overall power controller was modelled for both converter pole. Two operational scenarios of converter fault were simulated using PSCAD EMTDC. The converter firing angle and extinction angle, as well as the voltage-dependent current order limiter, was monitored and plotted on a graph. Results show that the MTDC link became unstable during the full deblocking stage with a continuous occurrence of commutation failure. Furthermore, the results presented in this paper show that during partial converter de-blocking showed a favourable performance, as the power system remains stable and commutation failure of the MTDC system is prevented.
11
Chu, Wei Hua, Wen Gai, and Zheng Hua Gu. "Research on Movement Relationship and Multi-Axis Motion Control Strategy for the Big Attack Angle Device of the Low-Speed Wind Tunnel." Advanced Materials Research 945-949 (June 2014): 1517–23. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.1517.
Повний текст джерелаАнотація:
For the big angle attack device of 4m×3m low-speed wind tunnel, the attack angle device α change is realizes through the triangle link block organization, realizes angle of attack Alpha uniform speed revolving is a misalignment speed control process. In order to guarantee the blocking in realizes the angle of attack Alpha and in the angle of slide Beta pinpointing process, according to the request angular speed uniform speed rotation, and guaranteed that the model center does not deviate in the rotation process the wind tunnel center, this article, in the angle of attack Alpha organization, the angle of slide Beta organization, Y to the elevating mechanism, Z carry on the comprehensive mathematical analysis to the crosswise translation organization speed and the potential motion relations in the foundation, has conducted the deep research to the multiple spindle linkage speed and the position control method, finally uses the control hypothesized kingbolt, Alpha, Beta, y, the z organization position follow.
12
Xie, Xin, Majid Bigdeli Karimi, Sanwei Liu, Battushig Myanganbayar, and Carol Livermore. "Micro Motion Amplifiers for Compact Out-of-Plane Actuation." Micromachines 9, no. 7 (July 23, 2018): 365. http://dx.doi.org/10.3390/mi9070365.
Повний текст джерелаАнотація:
Small-scale, out-of-plane actuators can enable tactile interfaces; however, achieving sufficient actuator force and displacement can require larger actuators. In this work, 2-mm2 out-of-plane microactuators were created, and were demonstrated to output up to 6.3 µm of displacement and 16 mN of blocking force at 170 V. The actuators converted in-plane force and displacement from a piezoelectric extensional actuator into out-of-plane force and displacement using robust, microelectromechanical systems (MEMS)-enabled, half-scissor amplifiers. The microscissors employed two layers of lithographically patterned SU-8 epoxy microstructures, laminated with a thin film of structural polyimide and adhesive to form compact flexural hinges that enabled the actuators’ small area. The self-aligned manufacture minimized assembly error and fabrication complexity. The scissor design dominated the actuators’ performance, and the effects of varying scissor angle, flexure thickness, and adhesive type were characterized to optimize the actuators’ output. Reducing the microscissor angle yielded the highest actuator performance, as it maximized the amplification of the half-scissor’s displacement and minimized scissor deformation under externally applied loads. The actuators’ simultaneously large displacements and blocking forces for their size were quantified by a high displacement-blocking force product per unit area of up to 50 mN·µm/mm2. For a linear force–displacement relationship, this corresponds to a work done per unit area of 25 mN·µm/mm2.
13
Ji, Juanjuan, Yecai Guo, Lanfang Zhang, and Lihua Zhang. "3D Variable Coefficient KdV Equation and Atmospheric Dipole Blocking." Advances in Meteorology 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/4329475.
Повний текст джерелаАнотація:
A (2 + 1)-dimensional variable coefficient Korteweg-de Vries (3D VCKdV) equation is first derived in this paper by means of introducing 2-dimensional space and time slow-varying variables and the multiple-level approximation method from the well-known barotropic and quasi-geostrophic potential vorticity equation without dissipation. The exact analytical solution of the 3D VCKdV equation is obtained successfully by making use of CK’s direct method and the standard Zakharov–Kuznetsov equation. By some arbitrary functions and the analytical solution, a dipole blocking evolution process with twelve days’ lifetime is described, and the result illustrates that the central axis of the dipole is no longer perpendicular to the vertical direction but has a certain angle to vertical direction. The comparisons with the previous researches and Urals dipole blocking event demonstrate that 3D VCKdV equation is more suitable for describing the complex atmospheric blocking phenomenon.
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Kojima, Kazutoshi, Satchiko Ito, Akiyo Nagata та Hajime Okumura. "Improvement of Homoepitaxial Layer Quality Grown on 4H-SiС Si-Face Substrate Lower than 1 Degree Off Angle". Materials Science Forum 717-720 (травень 2012): 141–44. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.141.
Повний текст джерелаАнотація:
In this study, we struck a balance between specular surface morphology and polytype homogeneity on an epitaxial layer grown on 4H-SiC Si-face substrate with off angle less than 1degree by controlling the C/Si ratio with the SiH4 flow rate. Schottky barrier diodes fabricated on a grown epitaxial layer exhibited a blocking of voltage over 1000 V and an n value of less than 1.1 with a high yield of more than 80%. A substrate with a low off angle was found to have an advantage as regareds the stress that generates the interfacial dislocations at the epitaxial layer/substrate interface during the epitaxial growth process.
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Xu, Qi Lei, Gong You Tang, Hai Lin Liu, Shao Ting Ge, and Xue Yang. "Radom Intermediate Points Based Path Planning in Unknown Environment." Applied Mechanics and Materials 325-326 (June 2013): 1688–91. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.1688.
Повний текст джерелаАнотація:
This paper presents RandomBug, a novel real-time path planning algorithm, for an autonomous mobile agent in completely unknown environment. According to this algorithm, all the planned paths are described and stored in the form of vectors. When the agent moves along the planned paths, it only considers the rotation angle and the movement distance in a single direction. The algorithm combines range sensor data with a safety radius to determine the blocking obstacles and calculate the shorter path by choosing the random intermediate points. When there is obstacle blocking in the current path, the intermediate points will be calculated randomly and the planned path will be regenerated by inserting the selected random intermediate points. Simulation results are given to show the effectiveness of the proposed algorithm.
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Guan, Xin, Zhenwu Ma, Chunju Wang, Haidong He, Yuanjing Zhang, Xinwei Wang, and Weiwei Zhang. "Analytical Model for Springback Prediction of CuZn20 Foil Considering Size Effects: Weakening versus Strengthening." Materials 13, no. 21 (November 2, 2020): 4929. http://dx.doi.org/10.3390/ma13214929.
Повний текст джерелаАнотація:
The prediction of springback angle for ultra-thin metallic sheets becomes extremely difficult with the existence of size effects. In this study, size effects on the springback behavior of CuZn20 foils are investigated by experiments and analytical methods. The experimental results reveal that the springback angle first decreases gradually and then increases markedly with the decrease of foil thickness, which cannot be analyzed by current theoretical models. Then, an analytical model based on the Taylor-based nonlocal theory of plasticity is developed, in which the drastic increases of both the proportion of surface grains and the strain gradient are taken into account. Moreover, the influence of strain gradient is modified by the grain-boundary blocking factor. The calculation results show that the springback angle of foils is determined by the intrinsic competition between the decrement angle caused by surface grains and the increment angle caused by the strain gradient. Besides, the relative error of predicted springback angle by the model is less than 15%, which means that the developed model is very useful for improving the quality of micro sheet parts with high accuracy of springback prediction.
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Naik, Saurabh, Gabriel Malgaresi, Zhenjiang You, and Pavel Bedrikovetsky. "Well productivity enhancement by applying nanofluids for wettability alteration." APPEA Journal 58, no. 1 (2018): 121. http://dx.doi.org/10.1071/aj17149.
Повний текст джерелаАнотація:
Water blocking is a frequent cause for gas productivity decline in unconventional and conventional fields. It is a result of the capillary end effect near the wellbore vicinity. It creates significant formation damage and decreases gas well productivity. The alteration of the rock wettability by nanofluids is an effective way to reduce water blockage and enhance gas production. Presently, several types of surfactants and nanofluids are used in the industry for contact angle alteration. In this study, we developed an analytical model and analysed the sensitivity to several parameters. After the treatment, the porous medium in the well vicinity (or along the core) will have a stepwise constant contact angle profile. We derive analytical models for compressible steady-state two-phase linear and axi-symmetric flows, accounting for the piecewise-constant contact angle and contact-angle-dependent capillary pressure and relative permeability. The modelling reveals a complex interplay between the competing effects of compressibility, viscous and capillary forces, which influence the optimal contact angle for treatment. The optimal contact angle for treatment will depend on the initial wettability of the formation, the water cut and the capillary-viscous ratio.
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Suvalyan, M. A. "Treatment of comminuted diaphyseal fractures of the femur using closed blocking intramedullary osteosynthesis." N.N. Priorov Journal of Traumatology and Orthopedics 9, no. 1 (February 2, 2022): 40–44. http://dx.doi.org/10.17816/vto97095.
Повний текст джерелаАнотація:
During 1996-2000 at the Department of Urgent Traumatology of Loco-Motor System (Scientific Research Institute of Emergency Care named after N.V. Sklifosovskiy) intramedullar osteosynthesis using AO/ASIF blocked pin was performed in 20 patients with comminuted femur fractures (21 fractures). This method gives stabile fixation of fragments that allows to stand up and walk using crutches on 5-10 days after operation. Mean term of load bearing restoration and moving extremity function was 4.5 months. One patient had delayed fragments consolidation. No complications such as suppuration, extremity shortening, angle and rotation deformity were observed.
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Yi, X. S., S. L. Yu, W. X. Shi, S. Wang, L. M. Jin, N. Sun, C. Ma, and L. P. Sun. "Separation of oil/water emulsion using nano-particle (TiO2/Al2O3) modified PVDF ultrafiltration membranes and evaluation of fouling mechanism." Water Science and Technology 67, no. 3 (February 1, 2013): 477–84. http://dx.doi.org/10.2166/wst.2012.565.
Повний текст джерелаАнотація:
In the present study, nano-sized TiO2/Al2O3 modified polyvinylidene fluoride (PVDF) membranes (MM) were fabricated and then utilized for oil/water emulsion separation. The results showed that, compared with PVDF membrane (OM), the contact angle of MM decreased and hydrophilicity increased. The ultrafiltration (UF) of oil in water emulsions with transmembrane pressure (TMP) increasing results in a sharp fall in relative flux with time. The cake filtration models did not always predict the performance over the complete range of filtration times very well. In the initial 30 min, all the four cake models can simulate this UF process to a certain extent, and the suitability was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However, they were no longer adapted well with UF time extent to 60 min, but only cake filtration (R2 = 0.9535) maintained a high adaptability. Surface and cross-sectional morphology of the membrane was investigated by SEM to make an advanced certificate of this UF mechanism.
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LEE, J. A., O. R. BURGGRAF, and A. T. CONLISK. "On the impulsive blocking of a vortex–jet." Journal of Fluid Mechanics 369 (August 25, 1998): 301–31. http://dx.doi.org/10.1017/s0022112098001815.
Повний текст джерелаАнотація:
In this paper we consider the flow field within and around a vortex as it ‘collides’ with a thin plate at a right angle to its axis of rotation. We show that based solely on inviscid flow theory, vorticity in the core of the vortex is redistributed significantly. The main cause of this redistribution is the presence of axial flow within the vortex; we call this vortical structure which contains axial flow a vortex–jet. In this work we show that when the axial velocity within the vortex is toward the plate, vorticity is redistributed radially outward from the core resulting in a significant reduction in the axial vorticity there; the vortex is said to ‘bulge’ reflecting an increase in the nominal vortex core radius. A by-product of this interaction is that the suction peak amplitude caused by the presence of the vortex rapidly decreases and the pressure soon returns to a quasi-steady distribution. On the other hand, when the axial velocity within the vortex is directed away from the surface, the suction peak persists and the vortex core radius decreases. The numerical results were validated by comparison with an analytical solution for a sinusoidal vortex jet. Analytical solutions were also derived for the initial and final states of a pure jet; the numerical results are strongly supported by the analysis. In addition, all of these results are consistent with experiments, and their relevance to the interaction between a tip vortex and a helicopter airframe is also discussed.
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Xu, Qi-lei. "RandomBug: Novel Path Planning Algorithm in Unknown Environment." Open Electrical & Electronic Engineering Journal 8, no. 1 (December 31, 2014): 252–57. http://dx.doi.org/10.2174/1874129001408010252.
Повний текст джерелаАнотація:
This paper presents a novel real-time path planning algorithm for an autonomous mobile agent in completely unknown environment. In this algorithm, all the planned paths are described and stored in the form of vectors in the algorithm. Only the rotation angle and the movement distance in a single direction are considered when the autonomous moves along the planned paths. The algorithm combines range sensor data with a safety radius, which determines the blocking obstacles and calculates a shorter path by choosing the random intermediate points. These random intermediate points are be generated when blocking obstacles exist in the current path. Then the optimal intermediate points are selected and inserted into the current path to regenerate a new planned path. Simulation results are shown that the proposed algorithm is effective.
22
Tian, Aifen, Xixi Wang, Yue Sun, Xinrong Zhang, Hongyan Wang, and Liang Yang. "Preparation and performance analysis of Pt-IPMC for driving bionic tulip." Journal of Advanced Dielectrics 11, no. 04 (July 26, 2021): 2150017. http://dx.doi.org/10.1142/s2010135x2150017x.
Повний текст джерелаАнотація:
Based on the biological characteristics of tulip, the low driving voltage and fast response of ionic polymer metal composite (IPMC), we analyzed the fabrication, morphology and performance of the platinum IPMC (Pt-IPMC) and selected the right IPMC for driving bionic tulip. The preparation and performance of IPMC was analyzed first in this paper such as blocking force, output displacement and bending angle of IPMC under the different directed current voltage (DC). The optimal IPMC sample size and driving voltage were selected based on tulip blooming angles and the strain energy density of IPMC, which completed the blooming process of bionic tulip. The feasibility of IPMC used in driving bionic field was fully proved in this paper, which laid a foundation for the application of IPMC in driving biomimetic biological robots.
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Jiang, Qingfang. "Precipitation over Concave Terrain." Journal of the Atmospheric Sciences 63, no. 9 (September 1, 2006): 2269–88. http://dx.doi.org/10.1175/jas3761.1.
Повний текст джерелаАнотація:
Abstract Many topographic barriers are comprised of a series of concave or convex ridges that modulate the intensity and distribution of precipitation over mountainous areas. In this model-based idealized study, stratiform precipitation associated with stratified moist airflow past idealized concave ridges is investigated with a focus on windward blocking, flow confluence, and the associated precipitation enhancement. It is found that flow confluence and precipitation enhancement by a concave ridge are controlled by the nondimensional ridge height M (M = Nmhm/U, where Nm is the moist buoyancy frequency, hm is the maximum ridge height, and U is the wind speed), based on which three dynamical regimes can be defined. In the linear regime (M < 0.4), a flow confluence zone is present over the upwind slope of the ridge vertex, where precipitation is significantly enhanced. The precipitation enhancement is due to the additional updraft driven by the horizontal flow convergence with a considerable contribution from lateral confluence. In the blocking regime (0.4 < M < Mc), the area and intensity of the flow confluence zone decrease with increasing mountain height due to low-level blocking. The critical nondimensional ridge height (Mc) for windward flow stagnation decreases with increasing concave angle. In the two regimes, flow confluence and precipitation enhancement are more pronounced for concave ridges with a longer cross-stream dimension or a larger concave angle. In the flow reversal regime (M > Mc), no steady state can be achieved and the precipitation enhancement at the vertex is absent. In addition, the flow confluence and precipitation enhancement upstream of a concave ridge are sensitive to the presence of a relative gap or peak at the vertex, the earth’s rotation, and the incident wind. The relevant dynamics has been examined.
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Pogna, Eva A. A., Xianchong Miao, Driele von Dreifus, Thonimar V. Alencar, Marcus V. O. Moutinho, Pedro Venezuela, Cristian Manzoni, Minbiao Ji, Giulio Cerullo, and Ana Maria de Paula. "Angle-tunable intersubband photoabsorption and enhanced photobleaching in twisted bilayer graphene." Nano Research 14, no. 8 (January 16, 2021): 2797–804. http://dx.doi.org/10.1007/s12274-021-3288-0.
Повний текст джерелаАнотація:
AbstractVan der Waals heterostructures obtained by artificially stacking two-dimensional crystals represent the frontier of material engineering, demonstrating properties superior to those of the starting materials. Fine control of the interlayer twist angle has opened new possibilities for tailoring the optoelectronic properties of these heterostructures. Twisted bilayer graphene with a strong interlayer coupling is a prototype of twisted heterostructure inheriting the intriguing electronic properties of graphene. Understanding the effects of the twist angle on its out-of-equilibrium optical properties is crucial for devising optoelectronic applications. With this aim, we here combine excitation-resolved hot photoluminescence with femtosecond transient absorption microscopy. The hot charge carrier distribution induced by photo-excitation results in peaked absorption bleaching and photo-induced absorption bands, both with pronounced twist angle dependence. Theoretical simulations of the electronic band structure and of the joint density of states enable to assign these bands to the blocking of interband transitions at the van Hove singularities and to photo-activated intersubband transitions. The tens of picoseconds relaxation dynamics of the observed bands is attributed to the angle-dependence of electron and phonon heat capacities of twisted bilayer graphene.
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Masumoto, Keiko, Kazutoshi Kojima, and Hajime Okumura. "The Growth of 3-Inch 4H-SiC Si-Face Epitaxial Wafer with Vicinal Off-Angle." Materials Science Forum 740-742 (January 2013): 193–96. http://dx.doi.org/10.4028/www.scientific.net/msf.740-742.193.
Повний текст джерелаАнотація:
We grew epitaxial layers on 3-inch epitaxial wafers with a vicinal off-angle, using a horizontal hot-wall chemical vapor deposition system that had a reactor capacity of 3 x 150 mm. Uniformity (σ/mean) of thickness and carrier concentration as small as 1.7% and 5.6%, respectively, were successfully obtained. We succeeded in decreasing triangular surface defects and polytype inclusions by increasing the growth temperature and lowering the C/Si ratio. In addition, I-V characteristics of Schottky barrier diodes on an epitaxial layer showed that a high blocking voltage of 960 V and a low leakage current of less than 1 x 10-6 A/cm2 were obtained with a yield of 78%.
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Amuedo, K. C., B. R. Williams, J. D. Flood, and A. L. Johns. "STOVL Hot Gas Ingestion Control Technology." Journal of Engineering for Gas Turbines and Power 113, no. 1 (January 1, 1991): 68–74. http://dx.doi.org/10.1115/1.2906532.
Повний текст джерелаАнотація:
A comprehensive wind tunnel test program was conducted to evaluate control of Hot Gas Ingestion (HGI) on a 9.2 percent scale model of the McDonnell Aircraft Company model 279-3C advanced Short Takeoff and Vertical Landing (STOVL) configuration. The test was conducted in the NASA-Lewis Research Center 9 ft by 15 ft Low Speed Wind Tunnel during the summer of 1987. Initial tests defined baseline HGI levels as determined by engine face temperature rise and temperature distortion. Subsequent testing was conducted to evaluate HGI control parametrically using Lift Improvement Devices (LIDs), forward nozzle splay angle, a combination of LIDs and forward nozzle splay angle, and main inlet blocking. The results from this test program demonstrate that HGI can be effectively controlled and that HGI is not a barrier to STOVL aircraft development.
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Wang, Jinwei, Wei Huang, Xiangyang Luo, Yun-Qing Shi, and Sunil Kr Jha. "Detecting Non-Aligned Double JPEG Compression Based on Amplitude-Angle Feature." ACM Transactions on Multimedia Computing, Communications, and Applications 17, no. 4 (November 30, 2021): 1–18. http://dx.doi.org/10.1145/3464388.
Повний текст джерелаАнотація:
Due to the popularity of JPEG format images in recent years, JPEG images will inevitably involve image editing operation. Thus, some tramped images will leave tracks of Non-aligned double JPEG ( NA-DJPEG ) compression. By detecting the presence of NA-DJPEG compression, one can verify whether a given JPEG image has been tampered with. However, only few methods can identify NA-DJPEG compressed images in the case that the primary quality factor is greater than the secondary quality factor. To address this challenging task, this article proposes a novel feature extraction scheme based optimized pixel difference ( OPD ), which is a new measure for blocking artifacts. Firstly, three color channels (RGB) of a reconstructed image generated by decompressing a given JPEG color image are mapped into spherical coordinates to calculate amplitude and two angles (azimuth and zenith). Then, 16 histograms of OPD along the horizontal and vertical directions are calculated in the amplitude and two angles, respectively. Finally, a set of features formed by arranging the bin values of these histograms is used for binary classification. Experiments demonstrate the effectiveness of the proposed method, and the results show that it significantly outperforms the existing typical methods in the mentioned task.
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Xu, Jiangtao, SX Jiang, Linghui Peng, Yuxiang Wang, Songmin Shang, Dagang Miao, and Ronghui Guo. "AgNps-PVA–coated woven cotton fabric: Preparation, water repellency, shielding properties and antibacterial activity." Journal of Industrial Textiles 48, no. 10 (March 20, 2018): 1545–65. http://dx.doi.org/10.1177/1528083718764908.
Повний текст джерелаАнотація:
Nowadays, there is a large demand for smart textiles by consumers. Smart textiles have different functions, and can provide comfort, safety and protection. In this study, electro-conductive woven cotton fabric is prepared in two steps. The cotton fabric samples are first impregnated and padded with a polyvinyl alcohol solution of 5% for multiple cycles (1, 3, 5 and 7 cycles) and dried. Then, silver nanoparticles are deposited onto the fabric through magnetron sputtering technology. The coated samples are examined using a Fourier transform infrared spectrometer, scanning electron microscope and X-ray diffractometer. The ultraviolet blocking, infrared reflection, electromagnetic shielding, and antibacterial properties are evaluated, as well as the contact angle, light transmittance and electrical conductivity. The results show that a polyvinyl alcohol film is successfully formed and the cotton fabric fibers are stuck together through hydrogen bonds. The light transmittance is increased after the polyvinyl alcohol pretreatment. After undergoing seven cycles of coating with polyvinyl alcohol, the silver nanoparticles-coated samples show large contact angle of 127.6°, excellent ultraviolet blocking property, a high infrared reflectivity of 30%, electrical resistivity of 1.46 × 10–6 Ω·m, electromagnetic interference shielding effectiveness of −20 dB and antibacterial efficacy of >99.5%. Compared to the untreated and silver-coated cotton without impregnation of polyvinyl alcohol, the silver nanoparticles–polyvinyl alcohol-coated cotton fabric sample has excellent performance, which makes it a promising textile with a multitude of protective properties.
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Tsuchida, Hidekazu, Toshiyuki Miyanagi, Isaho Kamata, Tomonori Nakamura, Kunikaza Izumi, Koji Nakayama, R. Ishii, Katsunori Asano, and Yoshitaka Sugawara. "Investigation of Basal Plane Dislocations in the 4H-SiC Epilayers Grown on {0001} Substrates." Materials Science Forum 483-485 (May 2005): 97–100. http://dx.doi.org/10.4028/www.scientific.net/msf.483-485.97.
Повний текст джерелаАнотація:
In this paper, we investigated the density of basal plane dislocations (BPDs) in 4H-SiC epilayers grown on (0001) and (000-1). Re-polishing of the substrate surface, in-situ H2 etching and off-cut angle were found to influence the propagation of BPDs into the epilayers. The epitaxial growth on (000-1) substrates yields a relatively low density of BPDs compared to growth on (0001). The electrical characteristics of pn diodes were also investigated, and the suppressed forward degradation and high-voltage blocking performance were obtained in the use of the (000-1) epilayers.
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Li, Gui Xian, Bang Qing Deng, De Fu Liu, and Fan Zhang. "Study on the Control of Industrial Dust from Alumina Production Process." Applied Mechanics and Materials 737 (March 2015): 599–602. http://dx.doi.org/10.4028/www.scientific.net/amm.737.599.
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The dust from industrial process does harm to the human health, the equipments and environment. Based on the comparison between bag filter and electrostatic precipitator, bag filter was used to control the dust from the industrial process with the filter cloth of polypropylene fiber needled felt. During run time, the filtration rate should be less than 1.59m/min and the pressure of the draught fan should be 3100Pa with the wind speed in the range of 22m/s to 24m/s, which eliminated the dust formation. And the size of dust hood should be heightened and lengthened in order to decrease dust escape and the cone angle of the dust hood should be more than 60°. In additon, in order to prevent the blocking of the ash unloading device, the best angle of the ash discharging pipe should be 60°. The dust collection system run well for five years and the collection efficiency was more than 99.0%, which created the benefits of environment, economics and society.
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Yang, Huiyu, Yaling Wang, Keshuai Liu, Xin Liu, Fengxiang Chen, and Weilin Xu. "Facile fabrication of ultraviolet-protective silk fabrics via atomic layer deposition of TiO2 with subsequent polyvinylsilsesquioxane modification." Textile Research Journal 89, no. 17 (December 2018): 3529–38. http://dx.doi.org/10.1177/0040517518813626.
Повний текст джерелаАнотація:
To develop ultraviolet (UV) light-protective silk fabrics (SFs), a conformal nanoscale TiO2 coating was deposited using an atomic layer deposition (ALD) method, and polyvinylsilsesquioxanes (PVSs) were further coated onto the SFs to enhance their hydrophobicity and UV light-resistance. Scanning electron microscopy and atomic force microscopy revealed hierarchical microstructures and nanostructures of the TiO2 coatings, which were primarily responsible for the increase of the water contact angle from approximately 0 to 120° after the ALD process. A high mean square surface roughness of 76.325 nm also accounted for this improved water contact angle. Furthermore, TiO2-coated SFs modified with low surface energy PVSs exhibited enhanced hydrophobic properties. More importantly, both the UV-blocking and yellowing-resistance of the SFs were improved without any significant change to the luster of the SFs. The ease and simplicity of this fabrication method makes it applicable to the preparation of multifunctional textiles with both good water repellency and UV-resistance.
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Chuaqui, T. R. C., M. W. D. Nielsen, J. Colton, R. Butler, and A. T. Rhead. "Effects of ply angle and blocking on open-hole tensile strength of composite laminates: A design and certification perspective." Composites Part B: Engineering 207 (February 2021): 108582. http://dx.doi.org/10.1016/j.compositesb.2020.108582.
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Gallaghar, Nicole J., Steve Provost, and Lewis A. Bizo. "A jump to the left and a step to the right: A test of two accounts of peak shift." Psychological Record 70, no. 1 (December 24, 2019): 11–20. http://dx.doi.org/10.1007/s40732-019-00366-1.
Повний текст джерелаАнотація:
Abstract“Peak Shift” usually occurs following intradimensional-discrimination training and involves a shift of the peak of the generalization gradient away from the original discriminative stimulus (S+) in a direction away from an S-. Two theoretical accounts of peak shift, the gradient interaction theory (GIT) and adaptation level theory (ALT), were compared. The effects of asymmetric test stimuli and the impact of instructions to participants for them to treat stimuli as members of categories on generalization gradients were investigated. In Experiment 1, the relation between peak shifts obtained when an extended asymmetric set of test stimuli was employed and the occurrence of categorization of the stimuli involved was investigated in four separate conditions. Two involved temporal discrimination, one involved line-angle discrimination, and one involved a compound line-angle and temporal cue discrimination. If participants treated the stimuli as belonging to discrete categories, such as hands-on a clock, rather than as being on continuous dimensions then responding to the compound cue was expected to result in attenuation of blocking of a peak shift. However, the peak shift obtained to the three cue types were the same. In Experiment 2, an independent group of participants was given explicit instructions to treat the line angles as if they were the hands of a clock face and this eliminated peak shift. The results from the present experiments support an ALT interpretation, although the peak shifts were significantly smaller in magnitude than predicted by this account.
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Ungureanu, Costel, and Costel Iulian Mocanu. "Influence of the hydrofoil inclination angle at free surface flow around junctions." Analele Universităţii "Dunărea de Jos" din Galaţi. Fascicula XI, Construcţii navale/ Annals of "Dunărea de Jos" of Galati, Fascicle XI, Shipbuilding 43 (December 15, 2020): 103–8. http://dx.doi.org/10.35219/annugalshipbuilding.2020.43.13.
Повний текст джерелаАнотація:
"Free surface flow is a hydrodynamic problem with a seemingly simple geometric configuration but with a flow topology complicated by the pressure gradient due to the presence of the obstacle, the interaction between the boundary layer and the free surface, turbulence, breaking waves, surface tension effects between water and air. As the ship appendages become more and more used and larger in size, the general understanding of the flow field around the appendages and the junction between them and the hull is a topical issue for naval hydrodynamics. When flowing with a boundary layer, when the streamlines meet a bluff body mounted on a solid flat or curved surface, detachments appear in front of it due to the blocking effect. As a result, vortex structures develop in the fluid, also called horseshoe vortices, the current being one with a completely three-dimensional character, complicated by the interactions between the boundary layer and the vortex structures thus generated. Despite the importance of the topic, the literature records the lack of coherent methods for investigating free surface flow around junctions, the lack of consistent studies on the influence of the inclination of the profile mounted on the body. As a result, this paper aims to systematically study the influence of profile inclination in respect to the support plate."
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Takei, Yoshiaki. "Techniques Used in Performing Handspring and Salto Forward Tucked in Gymnastic Vaulting." International Journal of Sport Biomechanics 4, no. 3 (August 1988): 260–81. http://dx.doi.org/10.1123/ijsb.4.3.260.
Повний текст джерелаАнотація:
The purpose of this study was to determine the mechanical factors that govern success in the performance of the handspring and salto forward tucked vault. The subjects were the 41 all-around gymnasts participating in the 1986 USA Gymnastics Championships. A motion-picture camera placed with its optical axis at right angles to the runway was used to record the performances of the subjects. Significant correlations indicated that the horizontal velocity at takeoff from the board was an important determinant for successful results, and also that the more the gymnast’s focus was on horse contact or blocking and the more vertical the direction of his effort at takeoff into the postflight, the better the final result. Quite unexpectedly, significant correlations revealed that the greater the relative height of takeoff from the horse and the less the height of CG at landing on the mat, the greater the points awarded by the judges. These relationships were almost entirely a consequence of the landing angle. Rationale for these findings were based on close observations of the filmed performances and the correlational analyses.
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Xue, Chao Hua, Wei Yin, Shun Tian Jia, and Jian Zhong Ma. "UV-Durable Superhydrophobic Textiles with UV-Shielding Property by Coating Fibers with ZnO/SiO2 Core/Shell Particles." Advanced Materials Research 441 (January 2012): 351–55. http://dx.doi.org/10.4028/www.scientific.net/amr.441.351.
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ZnO/SiO2 core/shell particles were fabricated and coated on poly (ethylene terephthalate) (PET) textiles, followed by hydrophobization with hexadecyltrimethoxysilane, to achieve superdrophobic surfaces with UV-shielding property. Transmission electron microscopy (TEM) was employed to reveal the fabrication of ZnO/SiO2 core/shell particles. Scanning electron microscopy (SEM) was conducted to investigate the surface morphologies of the textile and the coating of the fibers. UV-Vis spectrophotometry and contact angle measurement indicated that the incorporation of ZnO onto fibers imparted UV-blocking property to the textile surface, while the coating of SiO2 shell on ZnO made the superhydrophobicity of the as-treated PET textile surface UV-durable.
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LARSEN, AMY E., DAVID G. GRIER, and THOMAS C. HALSEY. "SCALING IN THE FREQUENCY-DEPENDENT ADMITTANCE OF ELECTRODEPOSITED FRACTAL ELECTRODES." Fractals 02, no. 02 (June 1994): 191–99. http://dx.doi.org/10.1142/s0218348x94000181.
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We describe measurements of the complex admittance of the interface between a class of fractal electrodes and electrolytic solutions over the frequency range 100 Hz to 40 kHz. The electrodes are grown by the diffusion-limited electrodeposition of copper from aqueous solution and have fractal dimensions comparable to those obtained for computer simulations of the diffusion-limited aggregation model, Df = 2.5. The admittance measured at various stages of the electrodeposit's growth displays constant phase angle (CPA) scaling with frequency. This behavior appears to have its origins in the disordered geometry of the system, although our measurements do not agree with the scaling predictions of theories for fractal blocking electrodes.
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CHEN, Z. Y., X. P. GUO, and Q. ZHANG. "ADSORPTION BEHAVIOR OF DODECYLAMINE AND ITS EFFECT ON THE WETTABILITY AND CORROSION OF CARBON STEEL." Surface Review and Letters 13, no. 01 (February 2006): 57–61. http://dx.doi.org/10.1142/s0218625x06007901.
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The adsorption behavior of dodecylamine and its effect on the wettability and corrosion of carbon steel in hydrochloric acid solution were studied. Polarization data suggest that inhibition of carbon steel corrosion is due to geometric blocking effect of adsorbed dodecylamine molecules on the metal surface, which leads to the formation of a monolayer on the metal. Phase images measured by tapping-mode atomic force microscopy (AFM) reveal different properties of the surface with and without various concentrations of dodecylamine. AFM force–distance curves indicate that sample surface exhibits adhesion characteristic after the adsorption of dodecylamine. Contact angle measurements show that dodecylamine reduces surface wettability obviously.
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Zhou, Yijie, Yong Qian, Senyi Wu, Xiaowen Zhong, Jinhao Huang, and Xueqing Qiu. "Incorporation of nano lignin reverse micelles on the transparency, UV-blocking and rheological properties of high-density polyethylene films." Holzforschung 74, no. 5 (May 26, 2020): 513–21. http://dx.doi.org/10.1515/hf-2019-0091.
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AbstractAiming to improve the poor miscibility between lignin and non-polar materials, alkali lignin (AL) was self-assembled into lignin reverse micelles (LRM) and blended with high-density polyethylene (HDPE) to fabricate composite films. The particle size of AL increased from 3.5 nm to 130 nm after forming LRM, showing a uniform spherical morphology. The water droplet contact angle increased from 54° to 89°. Optimal and rheological analysis revealed that composite films exhibited good transparency, ultraviolet (UV)-blocking performance and low viscoelasticity after adding the nano LRM. Under the optimal dosage of 5 wt% LRM, the composite film can screen 93% UV rays, and the apparent viscosities, complex viscosities, storage and loss modulus of the mixture were the lowest. Atomic force microscopy (AFM) was used to investigate the molecular interactions between lignin and HDPE. The average adhesion force between LRM and HDPE in dry air was 1.07 mN m−1, while that between AL and HDPE was 0.77 mN m−1. AFM experiments fundamentally demonstrated better compatibility between LRM and HDPE, which was beneficial for the improvement of UV-blocking, rheological properties, as well as their processability of LRM/HDPE films.
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Jurak, Sarah F., Emil F. Jurak, Md Nizam Uddin, and Ramazan Asmatulu. "Functional Superhydrophobic Coating Systems for Possible Corrosion Mitigation." International Journal of Automation Technology 14, no. 2 (March 5, 2020): 148–58. http://dx.doi.org/10.20965/ijat.2020.p0148.
Повний текст джерелаАнотація:
Because of their repellent, corrosion-mitigating, anti-icing, and self-cleaning properties, superhydrophobic coatings have numerous applications from windshields to textiles. A superhydrophobic coating is defined as one having a water contact angle (WCA) greater than 150° with a surface sliding angle less than 10°, and very low hysteresis between the advancing and receding angles. Its surface exhibits the so-called “lotus leaf effect,” whereby water bounces and balls up on contact. Here, water droplets run off readily, taking along dirt and dust for a self-cleaning effect that keeps the surface dry. The chemical composition of a surface affects the WCA, which can rise to 120°, but to achieve a WCA greater than 150°, which is considered superhydrophobic, an additional micro- and nanostructural component is needed. This functional hierarchical micro- and nanomorphology is exhibited in nature by plants and insects. A superhydrophobic coating on metallic substrates promises to provide corrosion mitigation by blocking oxygen and electrolytes, which are needed for the initiation of corrosion at the surface and interface. The methods used for preparing functional superhydrophobic coatings include sol-gel processing, layer-by-layer assembly, etching, lithography, chemical and electrochemical depositions, chemical vapor deposition, electrospinning, hydrothermal synthesis, and one-pot reactions. In this work, some research studies conducted to develop robust and durable superhydrophobic coatings are discussed in detail and analyzed for possible corrosion mitigation on the surfaces of metals and alloys. Scientists, engineers, students, and other participants in automotive, aircraft, energy, defense, electronics, and other industries will benefit greatly from this work.
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Uddin, Md Zulhash, Masashi Watanabe, Hirofusa Shirai, and Toshihiro Hirai. "Creeping and Novel Huge Bending of Plasticized PVC." Journal of Robotics and Mechatronics 14, no. 2 (April 20, 2002): 118–23. http://dx.doi.org/10.20965/jrm.2002.p0118.
Повний текст джерелаАнотація:
We actuated poly(vinyl chloride) (PVC) gel by applying a do field, and found localized creeping deformation, which induced swift, huge bending like a joint. The bending angle reached ca.150° at maximum at the field of 1000 V mm-1 with the velocity of ca. 90° s-1. The electric current was very small and in the range of 68 nA cm-2 . The mechanism of reversible, marked bending was studied using blocking and contact electrodes. The gel consisted of PVC and dioctyl phthalate (DOP), and was free of electrolytes. The concept is simple and applicable to conventional polymer materials. It could serve for developing new classes of soft and durable mechanically functional materials.
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Müllertz, Olivia, Jette Jacobsen, Jacob P. Thyssen, Anna Horwitz, and Miriam Kolko. "Betaxolol Ophthalmic Solution as Alternative Treatment for Patients with Timolol Allergy: A Case Report." Reports — Medical Cases, Images, and Videos 3, no. 3 (July 30, 2020): 21. http://dx.doi.org/10.3390/reports3030021.
Повний текст джерелаАнотація:
Background: To establish if an allergy towards all β-blockers, as a group, should be assumed, if an allergic reaction is observed while using one specific β-blocking agent. Case presentation: The non-selective β-blocker timolol caused a severe allergic ocular reaction in a non-atopic patient with advanced primary open-angle glaucoma. Results: A patch test confirmed timolol allergy. No allergic reaction to other anti-glaucomatous topical drugs was observed, and treatment with the selective β-blocker betaxolol was successfully initiated. Conclusion: Allergy to the non-selective β-blocker timolol does not necessarily predict allergy to the selective β-blocker betaxolol, and betaxolol should therefore not be excluded as an alternative treatment.
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Xu, Jin, Justin Varghese, Giuseppe Portale, Alessandro Longo, Jamo Momand, Ali Syari’ati, Jeroen A. Heuver, et al. "Chemical Solution Deposition of Ordered 2D Arrays of Room-Temperature Ferrimagnetic Cobalt Ferrite Nanodots." Polymers 11, no. 10 (September 30, 2019): 1598. http://dx.doi.org/10.3390/polym11101598.
Повний текст джерелаАнотація:
Over the past decades, the development of nano-scale electronic devices and high-density memory storage media has raised the demand for low-cost fabrication methods of two-dimensional (2D) arrays of magnetic nanostructures. Here, we present a chemical solution deposition methodology to produce 2D arrays of cobalt ferrite (CFO) nanodots on Si substrates. Using thin films of four different self-assembled block copolymers as templates, ordered arrays of nanodots with four different characteristic dimensions were fabricated. The dot sizes and their long-range arrangement were studied with scanning electron microscopy (SEM) and grazing incident small-angle X-ray scattering (GISAXS). The structural evolution during UV/ozone treatment and the following thermal annealing was investigated through monitoring the atomic arrangement with X-ray absorption fine structure spectroscopy (EXAFS) and checking the morphology at each preparation step. The preparation method presented here obtains array types that exhibit thicknesses less than 10 nm and blocking temperatures above room temperature (e.g., 312 K for 20 nm diameter dots). Control over the average dot size allows observing an increase of the blocking temperature with increasing dot diameter. The nanodots present promising properties for room temperature data storage, especially if a better control over their size distribution will be achieved in the future.
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Zhao, Yang, Di Xu, Jiazheng Sheng, Qinglong Meng, Dezhi Wu, Lingyun Wang, Jingjing Xiao, Wenlong Lv, Qinnan Chen, and Daoheng Sun. "Biomimetic Beetle-Inspired Flapping Air Vehicle Actuated by Ionic Polymer-Metal Composite Actuator." Applied Bionics and Biomechanics 2018 (2018): 1–7. http://dx.doi.org/10.1155/2018/3091579.
Повний текст джерелаАнотація:
During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities, such as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by combining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was compared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement and flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping displacement of the wing and the support reaction force were measured under different frequency by experiments. The experimental results indicate that the high voltage and low frequency would get large flapping displacement.
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Peng, Linghui, Ronghui Guo, Jianwu Lan, Shouxiang Jiang, Zhouyi Zhang, and Jiangtao Xu. "Preparation and characterization of copper-coated polyester fabric pretreated with laser by magnetron sputtering." Journal of Industrial Textiles 48, no. 2 (October 16, 2017): 482–93. http://dx.doi.org/10.1177/1528083717736101.
Повний текст джерелаАнотація:
Laser treatment is a high-efficiency coating process with many advantages of stable performance, convenient operation and environmental friendly. In this study, an efficient method for the pretreatment of polyester fabric, based on exposure to the output from a CO2 laser, is investigated. Polyester fabrics were treated by laser and then copper films were coated on the surface of treated polyester fabrics by magnetron sputtering method. Copper-coated polyester fabrics were characterized by XRD and SEM. Contact angle, heat generation and electrical conductivity of copper coated polyester fabric were tested. The electrical conductivity, UPF value and contact angle of copper-coated polyester fabric with pretreatment of 6.5 W lasers are 0.239 Ω/sq, 147.4, and 128.5°, respectively. The temperature of copper-coated fabric can be kept at 25.8℃ using only 5 V. The results suggest that the copper-coated polyester fabric with pretreatment of laser has excellent electrical conductive property, hydrophobicity, UV blocking, and heat generation properties. The adhesion strength between copper coating and fibers is improved after laser treatment. Laser can be potentially used in pretreatment of fabrics before coating in the future.
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Panchenko, S. P., Ye V. Yatsun, Ye O. Zemska, and M. L. Holovakha. "Influence of the angle of inclination of the load vector on the strength of the biodegradable screw for blocking intramedullary osteosynthesis." Bulletin of Prydniprovs’ka State Academy of Civil Engineering and Architecture, no. 3 (June 25, 2019): 77–86. http://dx.doi.org/10.30838/j.bpsacea.2312.040719.78.467.
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Gerber, Marius. "The interaction of deep-water gravity waves and an annular current: linear theory." Journal of Fluid Mechanics 248 (March 1993): 153–72. http://dx.doi.org/10.1017/s0022112093000722.
Повний текст джерелаАнотація:
The interaction of linear, steady, axisymmetric deep-water gravity waves with preexisting large-scale annular currents has been investigated. Waves originating inside the annulus as well as waves approaching the annulus from the outside were studied. Exact linear ray solutions were obtained and involve two non-dimensional parameters, a radius-angle parameter and a velocity parameter. For opposing currents the linear solutions also allow the derivation of radii at which the waves are blocked, reflected at a linear caustic or stopped by the current. Various examples of rays interacting with an annular current are presented to illustrate aspects of the solutions obtained. In particular, the behaviour of the ray solutions at blocking, reflection and stopping is investigated. Linear ray theory is shown to fail at caustics and caustic solutions are briefly discussed.
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Chen, Yu, Zhuoxiong Zeng, and Haoyuan Wang. "Combustion Turbulence Flow in the Advanced Vortex Combustor with Built-In Obstacles." International Journal of Aerospace Engineering 2021 (September 1, 2021): 1–22. http://dx.doi.org/10.1155/2021/7410747.
Повний текст джерелаАнотація:
To obtain the advanced vortex combustor (AVC) and its optimal structure parameters in light of built-in obstacles, numerical simulation was performed. This research shows that inclined struts have optimal structural parameters with inclination angle α = 30 ° and blocking ratio BR = 12 %, while guide vane and its optimal structural parameter have three layers, which are a / B = 0.1 , b / h = 0.4 , and c / L = 0.2 , respectively; blunt body has the biggest height of H 1 / B 1 = 2 / 3 . According to these statistics, the research studies how inlet factors affect turbulence flow in combustion. The research finds increases in inlet velocity and flow resistance are in positive correlation. As inlet temperature increases, the flow resistance decreases. From field synergy theory, inlet factor has different effect on the heat transfer performance.
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Dranyaev, S. B., M. N. Chatkin, and S. M. Koryavin. "Modeling the operation of a screw L-shaped knife of a tiller." Traktory i sel hozmashiny 84, no. 7 (July 15, 2017): 13–19. http://dx.doi.org/10.17816/0321-4443-66315.
Повний текст джерелаАнотація:
During the operation, standard L-shaped knives are exposed to various loads. The shape of the L-shaped knife blades does not meet the requirement of performing sliding cutting, which leads to an increase in the energy intensity of milling the soil. To ensure optimal cutting conditions without weed-covering and knife blocking, it is necessary that in any section of the blade (in the plane of rotation) the angle of its setting у (cutting) is constant. Therefore, the blade of the knife should be made on a screw line, which will ensure its smooth entry and sliding cutting when moving in the soil. The purpose of the study is to improve the quality and reduce the energy consumption of soil cultivation by selecting a rational angle for installing the blade and optimizing the parameters of the screwed L-shaped cutter blades. To study the work and the loading process of the screw L-shaped cutter knife, the finite element method was used from the APM FEM application library of the KOMPAS-3D system. The design of the knife was broken into elements to show their movements and deformations through the displacements of the boundary points (knots) of the element, then the nodal displacements, deformations and stresses were determined. In the course of the study, the dependence of the values of linear displacements and stress values was studied depending on the angle of installation of the knife blade (у = 35° ... 60°). The results of the study showed that as the angle of the blade was increased to у = 60 °, the total linear displacements decreased by 18 % reaching 0,6978 mm, compared to у = 35 ° (0,8455 mm) at a maximum load of 2000 N. The knife with an installation angle у = 60° has safety factor values higher than a knife with у = 35° for all load stages (500, 1000, 1500 and 2000 N). The screw knife with a large installation angle is most suitable for milling soil with slip, which is typical for sod processing. As a result of the research it was proposed to use knives with a screw working surface for milling the soil with high quality.
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Movsisyan, A. B., N. G. Glazko, A. Yu Brezhnev, and A. V. Kuroyedov. "Effect of intravitreal injections on the progression and prognosis of primary open-angle glaucoma." Russian Journal of Clinical Ophthalmology 21, no. 4 (2021): 227–34. http://dx.doi.org/10.32364/2311-7729-2021-21-4-227-234.
Повний текст джерелаАнотація:
Intravitreal injections (IVI) have revolutionized management strategies for many disorders, e.g., age-related macular degeneration (AMD), diabetic macular edema, retinal vein occlusion, choroidal inflammatory diseases, and pathologic myopia. Over the last two decades, exponential growth in the rate of IVIs has been seen worldwide. Primary therapeutic modalities include the courses of periodic injections to achieve and maintain the desired effect. Studies on the effects and neuroprotective role of vascular endothelial growth factor (VEGF) and agents blocking its action in various organs and tissues on the retina have demonstrated some differences in the outcomes and their interpretation which potentially affect IVI management strategy and treatment efficacy. Understanding the results and ocular changes in response to therapy (particularly in patients with glaucoma) requires special attention. A predicted increase in life expectancy and the number of patients with glaucoma suggests that the number of patients with several eye diseases who require IVIs will inevitably increase. In addition, some studies evaluate glaucoma progression after IVIs. Considering a lack of relevant data on long-term adverse effects on IOP level and cup area, and improvement of visual functions, IVIs are regarded as a safe treatment modality in patients with primary open-angle glaucoma (POAG) and ocular comorbidities that require IVIs. Keywords: intravitreal injections, glaucoma, vascular endothelial growth factor, retinal ganglionic cells, retinal nerve fiber layer, intraocular pressure, optical coherence tomography, optic disc. For citation: Movsisyan A.B., Glazko N.G., Brezhnev A.Yu., Kuroyedov A.V. Effect of intravitreal injections on the progression and prognosis of primary open-angle glaucoma. Russian Journal of Clinical Ophthalmology. 2021;21(4):227–234 (in Russ.). DOI: 10.32364/2311-7729-2021- 21-4-227-234.