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1
CHERNOV, N., R. MARKARIAN, and S. TROUBETZKOY. "Conditionally invariant measures for Anosov maps with small holes." Ergodic Theory and Dynamical Systems 18, no. 5 (October 1998): 1049–73. http://dx.doi.org/10.1017/s0143385798117492.
Повний текст джерелаАнотація:
We study Anosov diffeomorphisms on surfaces in which some small ‘holes’ are cut. The points that are mapped into those holes disappear and never return. We assume that the holes are arbitrary open domains with piecewise smooth boundary, and their sizes are small enough. The set of points whose trajectories never enter holes under the past iterations of the map is a Cantor-like union of unstable fibers. We establish the existence and uniqueness of a conditionally invariant measure on this set, whose conditional distributions on unstable fibers are smooth. This generalizes previous works by Pianigiani, Yorke, and others.
2
Singh, W. Sharatchandra, and C. K. Mukhopadhyay. "Detection of localised flaws in small-diameter carbon steel tubes using multi-NDE techniques." Insight - Non-Destructive Testing and Condition Monitoring 62, no. 11 (November 1, 2020): 649–55. http://dx.doi.org/10.1784/insi.2020.62.11.649.
Повний текст джерелаАнотація:
This paper proposes multi-NDE techniques for enhanced and reliable detection of localised defects or flaws in small-diameter (19.05 mm outer diameter (OD) and 2.77 mm wall thickness (WT)) low-carbon steel tubes. Multi-NDE techniques comprising magnetic flux leakage (MFL), remote field eddy current (RFEC) and the ultrasonic internal rotary inspection system (IRIS) are used to investigate the detectability and spatial resolution for the detection of localised flaws of different types and sizes, which simulate flaws generally formed in carbon steel tubes. The studies reveal that the MFL and IRIS techniques detect 0.55 mm-deep holes and notches while the RFEC technique detects 1.11 mm-deep holes and 0.55 mm-deep notches. The IRIS technique is capable of resolving axial and circumferential holes (1 mm diameter and 1.39 mm depth) of 2 mm hole-to-hole separation, while the MFL technique can resolve axial holes of 2 mm hole-to-hole separation but not circumferential holes. The RFEC technique can detect axial holes as a single hole but is unable to detect circumferential holes, resulting in no spatial resolution for the axial and circumferential holes. Compared to the MFL and RFEC signals, IRIS readily discerns the spatial extent of the flaws with the possibility of sizing from the images. The study also reveals that the resolution capability of the IRIS technique is influenced by the speed of the turbine rotation inside the tube.
3
Sun, W. J., Q. Q. Shi, S. Y. Fu, Z. Y. Pu, M. W. Dunlop, A. P. Walsh, Q. G. Zong, et al. "Cluster and TC-1 observation of magnetic holes in the plasma sheet." Annales Geophysicae 30, no. 3 (March 26, 2012): 583–95. http://dx.doi.org/10.5194/angeo-30-583-2012.
Повний текст джерелаАнотація:
Abstract. Magnetic holes with relatively small scale sizes, detected by Cluster and TC-1 in the magnetotail plasma sheet, are studied in this paper. It is found that these magnetic holes are spatial structures and they are not magnetic depressions generated by the flapping movement of the magnetotail current sheet. Most of the magnetic holes (93%) were observed during intervals with Bz larger than Bx, i.e. they are more likely to occur in a dipolarized magnetic field topology. Our results also suggest that the occurrence of these magnetic holes might have a close relationship with the dipolarization process. The magnetic holes typically have a scale size comparable to the local proton Larmor radius and are accompanied by an electron energy flux enhancement at a 90° pitch angle, which is quite different from the previously observed isotropic electron distributions inside magnetic holes in the plasma sheet. It is also shown that most of the magnetic holes occur in marginally mirror-stable environments. Whether the plasma sheet magnetic holes are generated by the mirror instability related to ions or not, however, is unknown. Comparison of ratios, scale sizes and propagation direction of magnetic holes detected by Cluster and TC-1, suggests that magnetic holes observed in the vicinity of the TC-1 orbit (~7–12 RE) are likely to be further developed than those observed by Cluster (~7–18 RE).
4
Hoáng, Viêt Há. "Homogenization of singularly perturbed Dirichlet problems in perforated domains." Proceedings of the Royal Society of Edinburgh: Section A Mathematics 130, no. 1 (February 2000): 35–51. http://dx.doi.org/10.1017/s0308210500000032.
Повний текст джерелаАнотація:
We study the singularly perturbed problem —εαΔuε + uε = f (α > 0) with the Dirichlet boundary condition in a perforated domain, in which the holes are distributed periodically with period 2ε throughout a fixed domain Ω. The asymptotic behaviour of uε when ε → 0, together with corrector results and error estimates in L2(Ω), are deduced for all sizes of holes. The behaviour of uε in is obtained for the cases where the size of holes is of order ε or is of a sufficiently smaller order. When the holes' size is of a sufficiently small order, as expected, uε has similar behaviour to that in the case of a non-varying domain.
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Bonnivard, Matthieu, Anne-Laure Dalibard, and David Gérard-Varet. "Computation of the effective slip of rough hydrophobic surfaces via homogenization." Mathematical Models and Methods in Applied Sciences 24, no. 11 (August 6, 2014): 2259–85. http://dx.doi.org/10.1142/s0218202514500201.
Повний текст джерелаАнотація:
We present a quantitative analysis of the effect of rough hydrophobic surfaces on viscous Newtonian flows. We use a model introduced by Ybert and coauthors in [Achieving large with superhydrophobic surfaces: Scaling laws for generic geometries, Phys. Fluids 19 (2007) 123601], in which the rough surface is replaced by a flat plane with alternating small areas of slip and no-slip. We investigate the averaged slip generated at the boundary, depending on the ratio between these areas. This problem reduces to the homogenization of a nonlocal system, involving the Dirichlet to Neumann map of the Stokes operator, in a domain with small holes. Pondering on the works of Allaire [Homogenization of the Navier–Stokes equations in open sets perforated with tiny holes. I. Abstract framework, a volume distribution of holes, Arch. Rational Mech. Anal. 113 (1990) 209–259; Homogenization of the Navier–Stokes equations in open sets perforated with tiny holes. II. Noncritical sizes of the holes for a volume distribution and a surface distribution of holes, Arch. Rational Mech. Anal. 113 (1990) 261–298]. We compute accurate scaling laws of the averaged slip for various types of roughness (riblets, patches). Numerical computations complete and confirm the analysis.
6
Marr, Charles W. "A Planting Template for Plug Flats." HortTechnology 1, no. 1 (October 1991): 120–21. http://dx.doi.org/10.21273/horttech.1.1.120.
Повний текст джерелаАнотація:
Seedlings are established in small growing containers to reduce cost of greenhouse space, while improving crop uniformity. These seedlings often are referred to as plugs. Vacuum seeders are used by larger growers to seed many flats per season (Bakos, 1983); however, individual growers, producing plants for their own use, may not be able to justify expensive seeding equipment. Several moderately priced vacuum seeders are available (Bartok, 1988). They consist of a metal tray with small drilled holes to hold the seed in place when a vacuum is applied to the tray from an external source. However, several problems with them exist. Seeds must be free of extraneous materials that might clog the small holes. A slight jarring of the plate, especially when the plate is turned upside down over the seed flat, may cause seeds to dislodge, resulting in unplanted cells in each flat. Also, different sizes of seeds and flats require completely different seeding plates and plate holders. A small grower may choose to seed flats by hand by placing seeds individually in each cell. This is feasible only for large-sized seeds or with pelleted seed. A simple, inexpensive, non-vacuum alternative design is presented and evaluated.
7
Sommers, Pacifica, Dorota L. Porazinska, John L. Darcy, Eli M. S. Gendron, Lara Vimercati, Adam J. Solon, and Steven K. Schmidt. "Microbial Species–Area Relationships in Antarctic Cryoconite Holes Depend on Productivity." Microorganisms 8, no. 11 (November 7, 2020): 1747. http://dx.doi.org/10.3390/microorganisms8111747.
Повний текст джерелаАнотація:
The island species–area relationship (ISAR) is a positive association between the number of species and the area of an isolated, island-like habitat. ISARs are ubiquitous across domains of life, yet the processes generating ISARs remain poorly understood, particularly for microbes. Larger and more productive islands are hypothesized to have more species because they support larger populations of each species and thus reduce the probability of stochastic extinctions in small population sizes. Here, we disentangled the effects of “island” size and productivity on the ISAR of Antarctic cryoconite holes. We compared the species richness of bacteria and microbial eukaryotes on two glaciers that differ in their productivity across varying hole sizes. We found that cryoconite holes on the more productive Canada Glacier gained more species with increasing hole area than holes on the less productive Taylor Glacier. Within each glacier, neither productivity nor community evenness explained additional variation in the ISAR. Our results are, therefore, consistent with productivity shaping microbial ISARs at broad scales. More comparisons of microbial ISARs across environments with limited confounding factors, such as cryoconite holes, and experimental manipulations within these systems will further contribute to our understanding of the processes shaping microbial biogeography.
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Fukagawa, Hitoshi, Toshiki Hirogaki, Keisuke Shimizu, and Kousuke Nishikawa. "Investigation of Decision Criteria for Abrasive Conditions in Multi-Small-Hole Drilling of CFRP by Blast Process." Advanced Materials Research 1136 (January 2016): 119–24. http://dx.doi.org/10.4028/www.scientific.net/amr.1136.119.
Повний текст джерелаАнотація:
Composite materials, such as CFRP, are hard-to-cut materials but useful for their specific strength. Usually creating small holes in them is done using drill tools, but tool abrasion occurs early, reducing quality, raising processing costs. Comparing drilling with other processing methods, it was revealed in a previous report that it was possible to effectively create large quantities of small holes using blasting [1]. However, such blast processing involves unknown mechanisms. In the present report, we investigated the material-removing mechanisms of blasting from the viewpoint of erosion abrasion, and looked into the most suitable method by changing hole sizes and processing conditions. The results revealed, relationships between abrasive particle size and hole accuracy or hole processing efficiency as well as the optimum abrasive combinations according to hole diameter.
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Niemz, Peter, Claus-Thomas Bues, and Steffen Herrmann. "Die Eignung von Schallgeschwindigkeit und Bohrwiderstand zur Beurteilung von simulierten Defekten in Fichtenholz | Use of sound velocity and drilling resistance to evaluate simulated defects in Norway spruce." Schweizerische Zeitschrift fur Forstwesen 153, no. 6 (June 1, 2002): 201–9. http://dx.doi.org/10.3188/szf.2002.0201.
Повний текст джерелаАнотація:
The influence of stem thickness and artificially made defects (drill holes and cracks of different sizes) was tested in spruce for sound velocity using two different instruments;an Impulshammer with 300 Hz and a BP 5 with 50 kHz). Comparative drilling resistance was measured with a Resistograph 1410, and we were able to identify very small defects.
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Cheng, Yu-qi, Wen-long Li, Cheng Jiang, Gang Wang, Wei Xu, and Qing-yu Peng. "A novel cooling hole inspection method for turbine blade using 3D reconstruction of stereo vision." Measurement Science and Technology 33, no. 1 (November 29, 2021): 015018. http://dx.doi.org/10.1088/1361-6501/ac39d0.
Повний текст джерелаАнотація:
Abstract Cooling holes (number 100 ∼ 200, diameter 0.3 ∼ 1.2 mm) are important heat dissipation structures of a turbine blade in aero-engine. Due to the small sizes and similar contours of cooling holes, it is difficult to extract and match their features by traditional stereo reconstruction methods. This paper proposes a novel cooling hole inspection method for turbine blades utilizing 3D reconstruction technique of stereo vision, which combines the stereo vision principle with the invariance of cross-ratio. The feature points of contours are extracted and matched by calculating two intersection points of circular contours and a line through the center points of adjacent cooling holes. Additionally, the 3D points corresponding to the feature points are reconstructed, by which, the diameters of cooling holes can be calculated successfully. Moreover, measurement experiments verify the effectiveness and accuracy of the proposed method. The experimental results show that the average errors of the standard circle ruler and tiny hole sample are within 0.05 mm, which satisfies the inspection requirement of cooling holes.
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Morrison, Malcolm J., and A. G. Xue. "The influence of seed size on soybean yield in short-season regions." Canadian Journal of Plant Science 87, no. 1 (January 1, 2007): 89–91. http://dx.doi.org/10.4141/p05-209.
Повний текст джерелаАнотація:
Two field experiments were done to determine if simple mechanical selection for seed size in soybean (Glycine max L. Merr.) could improve emergence and yield in short-season regions. Stacked screens with round holes 7.54, 7.14, 6.35 and 5.95 mm in diameter classified seeds into large, medium, small, and unscreened sizes. In exp. 1, small seeds resulted in lower yield than medium, large and unscreened seeds in two out of three cultivars, while in the third cultivar small seeds yielded less than the medium and large seed sizes, but were not significantly different from the unscreened size. In exp. 2, soil texture and seed size had a variable influence on seed emergence, which did not translate into consistent significant yield differences. Future research into mechanically removing small seeds from commercial seed lots is warranted in the short-season region. Key words: Seed size, soil texture, soybean, Glycine max L. Merr.
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Jiang, Xintong, Zhixiang Yin, and Hanbo Cui. "Wind Tunnel Tests of Wind-Induced Snow Distribution for Cubes with Holes." Advances in Civil Engineering 2019 (November 22, 2019): 1–12. http://dx.doi.org/10.1155/2019/4153481.
Повний текст джерелаАнотація:
The nonuniform distribution of snow around structures with holes is extremely unfavorable for structural safety, and the mechanism of wind-snow interaction between adjacent structures with holes needs to be explored. Therefore, a wind tunnel simulation was performed, in which quartz particles with an average particle size of 0.14 mm as snow particles were used, and cubes with dimensions of 100 mm × 100 mm × 100 mm each containing a hole with the size of 20 mm × 20 mm were employed as structures. Firstly, the quality of a small low-speed wind tunnel flow field was tested, and then the effects of hole orientation (hole located on the windward side, leeward side, and other vertical sides) and absence of holes on the surface of a single cube were studied. Furthermore, the effects of different hole locations (respectant position, opposite position, and dislocation) and relative spacing (50 mm, 100 mm, and 150 mm) on the surfaces of two cubes and the snow distribution around them were investigated. It was concluded that the presence and location of hole had a great influence on snow distribution around cubes. Snow distribution was favorable when hole was located on the other vertical sides of the test specimen. The most unfavorable snow distribution was obtained when the holes on the two-holed sides of the cubes were respectant with a maximum snow depth coefficient of 1.4. A significant difference was observed in the snow depths of two sides of cubes when holes were dislocated. When two holes were respectant, surrounding snow depth was decreased, and the maximum snow depth on model surface area was increased with the increase of spacing. Wind tunnel tests on holed cubes provided a reference for the prediction of snow load distribution of typical structures with holes.
13
Eigenmann, Bernd. "X-Ray Optics and Precision Requirements for Residual Stress Analyses with High Spatial Resolution." Advanced Materials Research 996 (August 2014): 228–33. http://dx.doi.org/10.4028/www.scientific.net/amr.996.228.
Повний текст джерелаАнотація:
In recent years, the demand for high spatial resolution in X-ray residual stress analysis has drastically increased. The locations of interest are frequently small foot radii of teeth of gears. Also the inner surface of holes or hollow cylinders in general with small diameter must be investigated after opening the cylindrical cavities. In resolving such measuring problems, significant progress has been made in reproducibly manufacturing and applying glass capillary X-ray optics. With focusing elliptical polycapillaries and conventional laboratory X-ray sources, spot sizes of few 10 μm can be realized at sufficiently intensities for residual stress analyses. However, glass capillary optics require refined alignment strategies which are completely different from those for conventional beam shaping optics. Moreover, the small spot sizes cannot be aligned and positioned on the sample surface by eye. Microscopy fixtures are required. Finally, measurements in small radii result in high precision requirements for the diffractometers as well as for the sample positioning in axes and directions which are significantly less relevant when measuring on plane surfaces. The specific requirements resulting from residual stress analyses with high spatial resolution using glass capillaries and small spot sizes at curved surfaces are described and discussed.
14
Olien, William C., C. P. Hegwood, and James M. Spiers. "Planting Methods Affect Early Growth and Root Distribution of Muscadine Vines." HortScience 28, no. 11 (November 1993): 1089–91. http://dx.doi.org/10.21273/hortsci.28.11.1089.
Повний текст джерелаАнотація:
Muscadine (Vitis rotundifolia Michx.) vineyards can be difficult to establish due to poor vine growth or survival during the first year after planting. Effects of the planting hole (five types), root manipulation (three levels), and peat amendment (0% and 50%) on first-year growth were studied at two sites with different soil types: a sandy loam (well-drained) and a silty loam (moderately well-drained). The planting hole had the major effect at both sites; large holes (25 liters) shoveled with straight or angled sides resulted in more shoot and root dry weight and greater total root length than auger holes (21 liters) or small shovel holes (10 liters). Vine response to planting in a subsoil slot 0.5 m deep × 6 m long was similar to that in large holes in sandy soil and small holes in heavier soil. Root manipulation treatments had little effect on vine establishment. Root pruning at planting, with or without root separation, did not increase vine dry weight relative to an undisturbed root ball in either soil type, but total root length was increased by root pruning in the heavier silty loam soil. Peat amendment increased total root length in the sandy soil but not in the silty loam soil.
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SZYMCZAK, H., L. GENZEL, and A. WITTLIN. "BOUND SMALL POLARONS IN HIGH-Tc SUPERCONDUCTORS." International Journal of Modern Physics B 04, no. 07n08 (June 1990): 1369–78. http://dx.doi.org/10.1142/s0217979290000668.
Повний текст джерелаАнотація:
The thermal and acoustic anomalies in high-Tc superconductors are interpreted in terms of contributions arising from the tunneling motion of bound small polarons. The small polarons arise in YBa 2 Cu 3 O 7 oxides due to the localization of the holes on one of the four O 2− ions surrounding the Cu(2) site in the CuO2 plane. The optical absorption band located at 0.4 eV is explained as a light-induced transfer of holes between the equivalent O 2− sites. It is argued that the strong hole-lattice interaction is responsible for the enhanced oscillator strength of optical phonons in YBa 2 Cu 3 O 7.
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Stepanian, N. N. "Coronal Holes and Background Magnetic Fields on the Sun." International Astronomical Union Colloquium 144 (1994): 61–64. http://dx.doi.org/10.1017/s0252921100025008.
Повний текст джерелаАнотація:
AbstractSize, lifetime and rotational rate of coronal holes (CH) and their connection with background magnetic field (BMF) structures were studied on the base of Solar Geophysical Data (1977-1987).Mean sizes of CH are (1-3) × 1011cm, changing with solar cycle and latitude. Mean life time is 5 rotations. Only small part of CH has rigid rotation. Most of them show differential rotation. CH appear in structures of BMF with the sign of polar magnetic field of corresponding hemisphere about 5-10 rotations after polar field reversal. Rotation rates of CH and BMF near the solar equator are almost the same. Rotational rate of BMF falls with latitude faster than the CH rate. Rotation differential of CH changes with solar cycle, BMF has no such connection.These results speak about different nature of BMF and CH, and the different depth of their sources. The source of CH is located deeper than that of the background magnetic field.
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Lee, Heow Pueh, Sanjay Kumar, and Jie Wei Aow. "Proof-of-Concept Design for MPP Acoustic Absorbers with Elements of Art." Designs 5, no. 4 (November 16, 2021): 72. http://dx.doi.org/10.3390/designs5040072.
Повний текст джерелаАнотація:
A micro-perforated plate or panel (MPP) is a device used to absorb sound. It consists of a thin flat plate made from several different materials with small holes and a back cavity. Several reported modifications and enhancements to the original design of the MPP acoustic absorber were modified by the holes or the back-cavity shape and sizes following the original idea. The present study attempts to artistically beautify the MPP acoustic absorbers by incorporating dotted arts into the design of MPP. The perforation for micro-perforated panels could be dotted arts with a perforation size smaller than 1 mm for enhanced acoustic absorption performance in the form of various artistic designs. Small LED lights could be placed inside the acoustic chamber to create the color lights emanating from the perforations instead of dots with different colors. Several MPP incorporated artistic designs of dotted patterns were presented and their acoustic absorption performance was analyzed using impedance tube in this paper.
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Filipowicz, Michał, Piotr Wach, Kryspin Burdyński, Jerzy Michalski, and Zenon Komorek. "Gas nitriding of inner surfaces of deep holes." Inżynieria Powierzchni 23, no. 2 (August 16, 2018): 24–29. http://dx.doi.org/10.5604/01.3001.0012.2091.
Повний текст джерелаАнотація:
In industrial applications of thermo-chemical treatments, gas nitriding is a widespread method of nitriding. Machine parts and tools of various shapes and sizes are nitrided, including drills, cutters, dies, shafts, rings, bearing balls, etc. often characterized by a complicated shape. The nitrided layers should have a controlled thickness not only of the diffusion zone, but also the surface layer of iron nitrides to have good exploitation properties. With a properly prepared surface on low alloy steels, we obtain a uniform nitrided layer after nitriding. It may happen that the structure of the nitrided layer is heterogeneous or even completely lacking in the nitrided parts having a complicated shape, and especially thin inner openings, where it is difficult to properly prepare the surface. Therefore, the nitriding problem is not the external surface of the workpieces but the internal one. The aim of the work was to assess the possibility of nitriding deep holes with small diameter. The tests were carried out on cylindrical specimens of unalloyed and low-alloy steel with electro-bored and mechanically hollow through holes and blind holes. The quality of the obtained nitrided layers was evaluated by metallographic and hardness examinations.
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Yao, S. T., Q. Q. Shi, Z. Y. Li, X. G. Wang, A. M. Tian, W. J. Sun, M. Hamrin, et al. "Propagation of small size magnetic holes in the magnetospheric plasma sheet." Journal of Geophysical Research: Space Physics 121, no. 6 (June 2016): 5510–19. http://dx.doi.org/10.1002/2016ja022741.
Повний текст джерела
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Lobao, Mario. "Paper 09: Postage-Stamp Glenoid Fracture after Bankart Repair. How Many Anchors are Safe? - A Biomechanical Analysis." Orthopaedic Journal of Sports Medicine 10, no. 5_suppl3 (May 1, 2022): 2325967121S0054. http://dx.doi.org/10.1177/2325967121s00547.
Повний текст джерелаАнотація:
Objectives: Fractures of anterior glenoid rim, aka “Postage-Stamp” fractures, are potential complications of arthroscopic Bankart repairs that occur when a fracture line propagates through previous anchor sites producing a serrated edge. (Fig.1: A and J) Placing multiple anchors adjacent to glenoid rim in attempt to recreate the labral bumper was suggested to reduce the risk of recurrent dislocation after surgery, [Boileau et al 2006] as well as to create a stress riser that may predispose to fracture if another traumatic event may occur. This controlled laboratory study investigated the effect of increased number holes, and different types and sizes of suture anchors on the load necessary to create Postage-Stamp fractures. Our objective was to establish a safe number of anchors that could be inserted in the anterior glenoid rim without incurring in a substantially high risk of fracture. Hypothesis: Increasing the number of holes and anchors and their size would decrease forces necessary to break the anterior glenoid rim. Methods: We tested 46 synthetic scapulae with similar compressive strength and elastic modulus of human glenoid (4th gen. composite scapulae, Sawbones, Pacific Research Laboratories, USA) in a servohydraulic apparatus (Fig.1: B and H) following a previous published biomechanical model. [Farmer et al2014] A guide ensured holes were drilled and anchors were inserted in the same exact angle, depth and location for every specimen. (Fig.1: C to F) A metallic humeral head applied force to the anterior glenoid rim at 1mm/s until fracture occurred. (Fig. 1: G to K) Load-to-fracture of intact glenoid was compared to groups of drilling anchor holes (# 3,4,5,6 and 7) of different diameters (1.6mm and 3mm), and groups with anchors of different sizes and types (1.6mm all-suture and 3mm core anchors).(Fig.1: I to K) One-way ANOVA followed by Turkey post-hoc test compared groups to determine the number of holes necessary to weaken glenoids below 70% of intact value with a p value <0.005. Results: Intact glenoid mean load-to-fracture was 1,238 ± 74N. Drilling 3 to 7 holes of 1.6mm-diameter linearly reduced load to 93%, 89%, 74%, 56% and 52% of intact value respectively, while 3.0mm drill holes reduced load to 87%, 65%, 51%, and 40% respectively.(Fig.2) Directly comparing drill role sizes there were significant differences on the 4, 5 and 7 holes groups (p=0.045, 0.032 and 0.015, respectively), so that a glenoid could safely sustain up to 5 holes of 1.6mm, but no more than 3 holes of 3.0mm-diameter.(Fig.3) Inserting 1.6mm “all-suture” anchors in the 1.6mm-diameter holes did not change the load-to-fracture on the 4 or 5 holes groups (Fig.4A), indicating that the number of drill holes was the main determinant of anterior glenoid rim strength, so that the all-suture anchors did not act as stress risers. Thus, up to 5 “all-suture” 1.6mm anchor could be safely used on a Bankart repair. The 3.0mm “core” anchors increased the load-to-fracture when compared to the group with the same number of holes of the same diameter size. Despite 4 holes of 3.0mm-diameter decreased the load-to-fracture bellow the safety line of 70% of intact value, the group with 4 anchors of 3.0mm-diameter “core” anchors increased load-to-fracture to 85% of intact value (p=0.033).(Fig.4B) This stress shield effect of the 3.0mm core anchor was not noticed on the 5 anchors group, in which the overall strength of the construction was bellow the 70% of intact safety line. Conclusions: Our data call in that up to four 3.0mm “core” anchors or five 1.6mm-diameter “all-suture” anchors could be safely inserted in the anterior glenoid rim without incurring in increased risk of Postage-Stamp fracture. One should prefer small diameter anchors if more than 4 anchors were intended on a Bankart repair. This study contributed to important data about number, size and type of anchors that the anterior glenoid rim could safely sustain in order to avoid postage-stamp fracture in case a new traumatic dislocation episode occur after a Bankart repair, which is of clinical interest in high risk population preoperative planning and selection of implant size, type and number.
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Yao, Xingyou. "Experimental Investigation and Load Capacity of Slender Cold-Formed Lipped Channel Sections with Holes in Compression." Advances in Civil Engineering 2021 (July 10, 2021): 1–18. http://dx.doi.org/10.1155/2021/6658099.
Повний текст джерелаАнотація:
The use of cold-formed steel (CFS) channels with circular or rectangular web holes is becoming increasingly popular in building structures. However, such holes can result in sections becoming more susceptible to buckle and display lower load-carrying capacities. This paper presents a total of 42 axial compression tests of CFS lipped channel slender columns with and without circular and rectangular web holes, including different hole sizes and cross sections. The test results show that the axial members with a small ratio of width to thickness were governed by global buckling, while the members with a large ratio of width to thickness were controlled by the interaction of local, distortional, and global buckling. The axial strength decreased maximum by 20.48% and 22.98% for the member with circular holes and rectangular holes, compared to a member without a web hole. Then, a nonlinear elastoplastic finite element model (FEM) was developed, and the analysis results showed good agreement with the test results. The validated FE model was used to conduct a parametric study involving 36 FEMs to investigate the effects of column slenderness, dimension of the hole, and the number of holes on the axial strength of such channels. Furthermore, the formulas to predict the global buckling coefficient and the effective area were modified for such sections with holes by using the verified FEM. Finally, the tests and parametric study results were compared against the design strengths calculated in accordance with the developed method. The comparison results show that the proposed design method closely predicts the axial capacity of CFS channels with circular or rectangular web holes.
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Uzer, Gökçer, Nuh Mehmet Elmadağ, Fatih Yıldız, Yunus Güzel, and Olgu Enis Tok. "Increasing number of small hole diameter microfracture compared with traditional microfracture in same size cartilage defects and effect of HA based aselluler scaffold. An animal study." Orthopaedic Journal of Sports Medicine 5, no. 2_suppl2 (February 1, 2017): 2325967117S0008. http://dx.doi.org/10.1177/2325967117s00081.
Повний текст джерелаАнотація:
Purpose: The purpose of this study is small hole microfracure method comparing with traditional microfracture method and investigation of effect of HA based acellular matrix scaffold on microfracture area. Materials-Methods: 21 Twenty-one New Zealand white rabbits were used for the in vitro portion of this study, bilateral knee joint from the same rabbit were same technic. An articular cartilage defect was established in the femoral trochlear groove about 5 mm. Control group was established alone microfracture (MF). 6 groups were formed in this study and each group has 3 rabbits and their six knees. In 3 groups were applied different number of small diameter hole microfracture (4,5,6 small holes microfracture respectively)and the other 3 groups were applied different number of small diameter hole microfracture (4,5,6 small holes micro fracture respectively added HA based acellular matrix scaffold in the same size ostechondral lesion. The regenerated tissues were harvested for gross morphology, histology at 12 weeks postoperatively. Results: Cartilage were regenerated, maintaining a constant thickness of cartilage. MF group has worse Wakitani scores than 6 small diameter holes mıcrofracture groups(group 6 and group 7) in either parameter of the score. (p=0,043, p=0,016) Matrix addition did not contribute to healing. (p=1,000) Conclusions: Increasing number of the small diameter holes microfracture (minimum %15 of defect size) improves cartilage repair compared with traditional MF in the same size ostechondral lesion. Also small diameter holes microfracture combined with HA-based AM implantation didn’t result in improved quality of the regenerated cartilage tissue.
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XIAO, MUFEI, NIKIFOR RAKOV, and LYDIA ALVAREZ. "THEORETICAL AND EXPERIMENTAL STUDY ON OPTICAL NEAR AND FAR FIELD TRANSMISSION OF THIN METALLIC FILMS WITH RANDOMLY DISTRIBUTED SUBWAVELENGTH HOLES." International Journal of Modern Physics B 20, no. 07 (March 20, 2006): 841–52. http://dx.doi.org/10.1142/s0217979206033528.
Повний текст джерелаАнотація:
We present theoretical calculations of the optical transmission through subwavelength apertures in a conducting screen of finite thickness. The results are employed to study the origin of the enhanced transmission observed in experiments where randomly distributed small holes of various subwavelength sizes are fabricated in a thin gold film. In the wavelength spectrum from 350 nm to 650 nm, a number of strongly enhanced transmission peaks are observed. These transmission peaks can only be observed in the near field. We discuss the experimental results in the light of the model calculations.
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Marshall, Madeline A., Yueying Ni, Tiziana Di Matteo, J. Stuart B. Wyithe, Stephen Wilkins, Rupert A. C. Croft, and Jussi K. Kuusisto. "The host galaxies of z = 7 quasars: predictions from the BlueTides simulation." Monthly Notices of the Royal Astronomical Society 499, no. 3 (October 5, 2020): 3819–36. http://dx.doi.org/10.1093/mnras/staa2982.
Повний текст джерелаАнотація:
ABSTRACT We examine the properties of the host galaxies of $z=7$ quasars using the large volume, cosmological hydrodynamical simulation BlueTides. We find that the 10 most massive black holes and the 191 quasars in the simulation (with $M_{\textrm{UV,AGN}}\lt M_{\textrm{UV,host}}$) are hosted by massive galaxies with stellar masses $\log (M_\ast /\, {\rm M}_{\odot })=10.8\pm 0.2$, and $10.2\pm 0.4$, which have large star formation rates of $513_{-351}^{+1225}\, {\rm M}_{\odot }/\rm {yr}$ and $191_{-120}^{+288}\, {\rm M}_{\odot }/\rm {yr}$, respectively. The hosts of the most massive black holes and quasars in BlueTides are generally bulge-dominated, with bulge-to-total mass ratio $B/T\simeq 0.85\pm 0.1$; however, their morphologies are not biased relative to the overall $z=7$ galaxy sample. We find that the hosts of the most massive black holes and quasars are compact, with half-mass radii $R_{0.5}=0.41_{-0.14}^{+0.18}$ kpc and $0.40_{-0.09}^{+0.11}$ kpc, respectively; galaxies with similar masses and luminosities have a wider range of sizes with a larger median value, $R_{0.5}=0.71_{-0.25}^{+0.28}$ kpc. We make mock James Webb Space Telescope (JWST) images of these quasars and their host galaxies. We find that distinguishing the host from the quasar emission will be possible but still challenging with JWST, due to the small sizes of quasar hosts. We find that quasar samples are biased tracers of the intrinsic black hole–stellar mass relation, following a relation that is 0.2 dex higher than that of the full galaxy sample. Finally, we find that the most massive black holes and quasars are more likely to be found in denser environments than the typical $M_{\textrm{BH}}\gt 10^{6.5}\, {\rm M}_{\odot }$ black hole, indicating that minor mergers play at least some role in growing black holes in the early Universe.
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de Sá, Bruno Costa Martins, Augusto Ricardo Andrighetto, Sergio Rocha Bernardes, and Rodrigo Tiossi. "Fracture Strength of Standard and Small Diameter Prosthetic Abutments for Full-Arch Implant-Supported Restorations." Journal of Oral Implantology 43, no. 3 (June 1, 2017): 175–79. http://dx.doi.org/10.1563/aaid-joi-d-16-00108.
Повний текст джерелаАнотація:
This study tested the fracture strength of prosthetic abutments with different sizes and combinations to support a 5-implant milled framework with distal extension. Prosthetic abutments with different dimensions (4.8-mm diameter mini conical abutment and 3.5-mm diameter microconical abutment) were screwed to 5 threaded implants. The following groups were divided (n = 3): G1 with 5 miniconical abutments (standard size), G2 with 5 microconical abutments (small sized), G3 with a combination of 3 small sized abutments and 2 standard sized abutments, and G4 with a combination of 2 small sized abutments and 3 standard sized abutments. Standardized titanium frameworks for full-arch fixed dental prosthesis were milled with equidistant holes for each of the 5 implants and abutments. A loading point was selected at 18 mm away from both distal implants. A universal testing system was used for the fracture strength tests and load was applied at a crosshead speed of 0.5 mm/min on the previously described loading points until component fracture. Mean fracture strength for each group was statistically compared (α = 0.05). Prosthetic screws were the only fractured components for all tested groups. Mean fracture strength was: G1, 1130.22 N; G2, 1031.36 N; G3, 757.9 N; and G4 792.03 N (P < .05). All prosthetic abutments and combinations that were tested provide adequate fracture strength for clinical use. However, the combination of standard and small diameter abutments leads to lower fracture strength compared with when only standard sized prosthetic abutments were used, irrespective of the abutment diameter (4.8- or 3.5-mm).
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Davydov, Vladimir, Aleksandr Nikitenko, Mihail Gimadeev, and Vera Berkun. "IMPROVING THE EFFICIENCY OF MILLING HOLES WITH A SMALL-SIZED TOOL IN THE CONDITIONS OF AUTOMATED PRODUCTION." Bulletin of Bryansk state technical university 2021, no. 10 (October 14, 2021): 13–21. http://dx.doi.org/10.30987/1999-8775-2021-10-13-21.
Повний текст джерелаАнотація:
The purpose of the paper. In order to solve the problems of increasing the efficiency of machining operations of small diameter holes by milling, the optimal range of cutting modes and helix pitch for the machining strategy with helical interpolation is established. The reduction of labor intensity and costs of hole machining when treating holes in alloyed corrosion-resistant steels is experimentally confirmed.
Research methods. In this paper, the issues of machining blind holes by helical interpolation milling with end cylindrical carbide cutters of relatively small dimensions in parts made of 12X18N10T alloy are considered. The features of this machining are availability of significant axial and radial components of the cutting forces with relatively low tool strength. This leads to the fact that a key factor of the tool failure is its mechanical failure, the cause of which is an increase in cutting forces due to the edge of the cutter being chipped.
Research results and novelty. It has been experimentally proved that the most rational machining parameters to ensure the specified accuracy and surface quality of the machined holes when using a strategy of helical interpolation milling will be the choice of the helix pitch p = 0.2 mm, the feed range F = 0.075-0.11 mm /tooth, which corresponds to the minute feeds of the milling center 450-675 mm/min.
Conclusions. The optimal range of cutting modes is found in the feed range from 450 to 675 mm/min, with a helical interpolation pitch of 0.2 mm. The accuracy and roughness of the holes obtained by milling with end mills with a diameter of 3 mm for steel 12X18N10T is evaluated.
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Abdukodyrova, Malokhat, Maria Radkevich, Kamila Shipilova, and Abdusamin Gapirov. "Sizes of the actively aerated zone and methods of the jet aerator calculation." E3S Web of Conferences 264 (2021): 01020. http://dx.doi.org/10.1051/e3sconf/202126401020.
Повний текст джерелаАнотація:
The possibilities of using jet aeration for biological wastewater treatment in small facilities were considered in the article. In shallow depth reservoirs, studies were carried out to change the sizes of the actively aerated zone with a decrease in the height of the liquid layer in the reservoir. The research was conducted for jet aerators with nozzles of the "keyway" type holes. It was established that a decrease in the relative depth of the reservoir makes it possible to increase the share of the beneficial use of the reservoir volume. This suggests that jet aeration will be most effective for reservoirs of relatively shallow depth. Based on the research results, a method for calculating a jet aerator was proposed, which makes it possible to evaluate the necessary parameters of the aerator based on the determination of the volumetric mass transfer coefficient.
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Nomura, Mitsuyoshi, Yong Bo Wu, Tsunemoto Kuriyagawa, Takahiro Kawashima, and Takayuki Shibata. "Study of Ultrasonically Assisted Internal Grinding of Small Holes: Effect of Grain Size of cBN Grinding Wheel." Advanced Materials Research 83-86 (December 2009): 1002–8. http://dx.doi.org/10.4028/www.scientific.net/amr.83-86.1002.
Повний текст джерелаАнотація:
This study aims to develop an ultrasonically assisted grinding technology for precision internal grinding of a small hole measuring several millimeters in diameter, such as those formed in a fuel injector for an automotive engine. In a previous work, an experimental apparatus mainly composed of an ultrasonic vibration spindle was designed and constructed, and grinding experiments were carried out. The previous investigation found that applying ultrasonic vibration to the wheel decreased the normal and tangential grinding forces, respectively, and improved the surface roughness in surface grinding. The purpose of this paper is to examine the effect of ultrasonic vibration on grinding force and surface roughness in internal grinding when the grain sizes of small cBN grinding wheel are changed. The experimental results indicate that applying ultrasonic vibration to the wheel decreases the normal and tangential grinding forces by more than 83 % and 80 %, respectively, and improves the surface roughness by as much as 62 % while the wheel grain size is changed. In addition, over the range of grinding conditions employed in this paper, the grain size as small as 3 µm can be used in ultrasonically assisted internal grinding.
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Bennett, Marylyn Hoy. "The SEM in present-day semiconductor FABS." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 778–79. http://dx.doi.org/10.1017/s0424820100149726.
Повний текст джерелаАнотація:
Computers, cars, HDTV, and microwave ovens: what great modern conveniences! Why do these marvels of technology work the way they do? The Scanning Electron Microscope has a lot to do with it. For the last decade, the shrinking geometries of integrated circuits have necessitated the use of the Scanning Electron Microscope (SEM) for inspection and metrology. The current device feature sizes in production are as small as 0.5μm, and current feature sizes under development are 0.25μm or smaller. The semiconductor industry depends on the SEM to tell us if our processes, whether production or developmental, are correct. Neither leading edge fabs nor developmental fabs could function very well without the SEM.The uses of the SEM are many and varied, both inside and outside the fab. Inside the fab, there are many inspection steps to be performed. Although the optical microscope is still a viable option for, and is still routinely used for, in-line wafer inspection, the SEM is indispensable for inspection (Fig. 1) of small geometries such as 0.35μm lines and spaces and 0.5μm contact holes.
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Hong, Cuiyue, and Xinping Zhang. "Optically processed microlens array for single-beam lithography of plasmonic structures." Nanophotonics 7, no. 11 (September 18, 2018): 1819–25. http://dx.doi.org/10.1515/nanoph-2018-0091.
Повний текст джерелаАнотація:
AbstractA 2D dielectric grating produced by photolithography was employed as a microlens array (MLA), which was based on a smooth surface and a shape that may be defined roughly as a hemisphere of each lattice. Such a 2D MLA can focus an incident ultraviolet light beam into a matrix of light spots, which were estimated to be as small as 500 nm in diameter. Using a thin layer of photoresist (PR) to record the pattern of the focusing spots, we achieved an approximately inversed structure of periodically arranged holes in PR in submicron sizes. Filling these holes with gold using chemically synthesized colloidal gold nanoparticles produced a plasmonic grating consisting of gold nanoparticles larger than 580 nm in average diameter. Localized surface plasmon resonance in both first and second orders was observed, which was verified by the spectroscopic response and theoretical simulations. MLA can be thus repeatedly used as a master to produce plasmonic photonic structures with high reproducibility.
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Slătineanu, Laurenţiu, Margareta Coteaţă, Hans Peter Schulze, Oana Dodun, Irina Besliu, and Lorelei Gherman. "Small Diameter External Cylindrical Surfaces Obtained by Ram Electrical Discharge Machining." Key Engineering Materials 611-612 (May 2014): 650–55. http://dx.doi.org/10.4028/www.scientific.net/kem.611-612.650.
Повний текст джерелаАнотація:
Electrical discharge machining uses the pulse electrical discharges generated between the closest asperities existing on the workpiece surface and the active surface of the tool electrode in dielectric fluid. Essentially, some distinct electrical discharge machining schemas could be used in order to obtain cylindrical external surfaces; within this research, one preferred a machining schema based on the use of a cooper plate in which there were small diameter holes, by taking into consideration the existence of a ram electrical discharge machine. The results of the machining process analysis were presented. A thin copper was considered to be used as tool electrode, in order to diminish the spurious electrical discharges, able to generate shape errors of the machined surface. Some experimental researches were developed by changing the sizes of the process input parameters. As output factors, the test piece and tool electrode masses decreases were considered. Power type empirical mathematical models were determined, in order to highlight the influence exerted by the pulse on time, off time and machining process duration on the output parameters values.
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GILCHRIST, JAMES E., ULYSSES S. RHEA, ROGER W. DICKERSON, and JEPTHA E. CAMPBELL. "Helium Leak Test for Micron-Sized Holes in Canned Foods." Journal of Food Protection 48, no. 10 (October 1, 1985): 856–60. http://dx.doi.org/10.4315/0362-028x-48.10.856.
Повний текст джерелаАнотація:
A helium leak test for canned foods was developed to provide a more sensitive method than existing ones and to reduce dependence on operator judgment for detecting leaking cans. The test forced helium through holes into cans filled with foods. Can headspace gas was sampled, and the helium content was measured by gas chromatography. An approximately linear (r = 0.81) relationship existed between the helium content of the headspace and the hole size in the can. The method detected holes as small as 1 μm in diameter (the smallest hole tested). Measurements of direct holes and dented seam holes in metal cans indicated that most holes tested smaller upon retesting. However, some seam openings did become larger. Some holes closed completely, probably as a result of clogging by particles. Cans with direct holes of known size were processed in a canning retort, and the cooling water was inoculated with ca. 106 bacteria/ml. Cans with holes greater than 5 μm became contaminated as exhibited by gas production during incubation at 37°C. The described helium test was compared with two modified conventional leak tests. When comparing cans with direct holes of known size, there was no difference between the methods. However, when comparing cans with leaks caused by dented seams, the helium test was found to be the most sensitive method for detecting leaks in cans of food. In order of their sensitivity, the tests for leaking cans were the helium test, the modified fluorescent dye test, and the modified vacuum test.
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Mitrus, Sławomir. "Acorn Ants May Create and Use Two Entrances to the Nest Cavity." Insects 12, no. 10 (October 6, 2021): 912. http://dx.doi.org/10.3390/insects12100912.
Повний текст джерелаАнотація:
Many ant species construct large nests that are inhabited by numerous workers, but other species dwell in ready-for-use cavities and live in small colonies. Ants of the genus Temnothorax inhabit small cavities, e.g., in acorns, twigs, and under rocks. Although a preference for nest sites with a narrower entrance is known, recent studies have shown that they also use cavities with wider entrances and may modify the size of such entrances. As good cavities for nest sites are a limited resource, the possibility to modify a potential nest site, including a reduction in the size of the hole, should be a favorable matter for the ants. Through field and laboratory experiments, I studied the acorn ant Temnothorax crassispinus. Observations showed that they readily inhabited imperfect cavities and, if necessary, modified the holes to such cavities. If they had to repair a nest site, they sometimes created a second entrance; there was no difference in the sizes of the entrances. In the field, for entrance modification or blocking an unnecessary hole, the acorn ants used soil, grains of sand, and parts of plants. In the laboratory, the ant colonies showed no preference for nest sites with one entrance vs. a nest cavity with two entrances. The results of this study showed that even such small ant colonies could use nest sites with multiple entrances; however, the effect of the presence of more than one entrance on the behavior of the ants is unknown.
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Byers, R. E., D. H. Carbaugh, and L. D. Combs. "162 The Influence of Root Restriction on Flowering, Fruiting, Tree Growth, Yields, and Fruit Quality of Apple Trees." HortScience 35, no. 3 (June 2000): 418A—418. http://dx.doi.org/10.21273/hortsci.35.3.418a.
Повний текст джерелаАнотація:
`Fuji'/MM.111, `Pink Lady'/M.7A, and `Summerfield'/M.7A apple trees were planted in several types of individual root restrictive bags in the field in 1995. Bags were made of Knit and Woven fabrics, Galvanize hardware cloth (6.4 cm) with various holes sizes and of different bag volumes. The bags confined the development of large roots to within the bag. Roots that penetrated the bag resulted in root branching and large root inhibition. As the roots enlarged, roots penetrating the bags were restricted in diameter by the fabric hole size. Roots enlarged to some degree on both sides of the fabric holes but were not killed by girdling within the first few years. Root restriction bags decreased trunk caliper, shoot growth, pruning weights, number of cuts per tree, increased flowering, fruit numbers, and weight per tree. Fruit firmness, soluble solids and color was increased and starch was lower than the nonbagged controls. In cage and tank trials pine and/or meadow voles easily penetrated all of the fabric and polypropylene bags within 24 h, except for the galvanized hardware cloth (6.4 cm). Susceptibility of each material to vole damage was tested by placement of an apple inside a small bag of each. Root restriction bags seemed to be a viable alternative to dwarfing rootstocks for control of tree size, early flowering, and early fruiting.
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Younes, M. F., Y. K. Younes, M. El-Madah, I. M. Ibrahim, and E. H. El-Dannanh. "An experimental investigation of hydrodynamic damping due to vertical baffle arrangements in a rectangular tank." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 221, no. 3 (August 13, 2007): 115–23. http://dx.doi.org/10.1243/14750902jeme59.
Повний текст джерелаАнотація:
The present work is concerned with an experimental study of the hydrodynamic damping provided by using vertical baffles in partially filled rectangular tanks. The damping ratio is evaluated for different vertical baffle dimensions, shapes, numbers, and arrangements. A small-scale test rig consisting of a partially filled rectangular tank with a pendulum suspension is designed and constructed to measure the transient responses of the system. The baffles are fitted to attenuate the lateral motion of the liquid slosh. Lower mounted and upper mounted vertical baffles of different heights and numbers are tested. Lower mounted vertical baffles with holes of different sizes and numbers are considered. Finally, the effect of a combination between upper, lower, and holed vertical baffles on the system damping is investigated. The results show that the size and location of the vertical baffles significantly influence the hydrodynamic damping. In general, the damping ratio increases as the tip of the lower mounted baffle plate is close to the liquid free surface and the location of the plate is close to the centre of the tank. Increasing the baffle numbers increases the damping ratio. The upper mounted vertical baffles are more suitable for a chargeable tank. The twin side upper mounted baffles and centre-holed lower mounted baffle arrangements give a maximum damping ratio.
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Matsui, Kenta, Hirokazu Matsumoto, Satoru Takahashi, and Kiyoshi Takamasu. "New Non-Contact Measurement of Small inside-Diameter Using Tandem Low-Coherence Interferometer and Optical Fiber Devices." Key Engineering Materials 523-524 (November 2012): 871–76. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.871.
Повний текст джерелаАнотація:
Recently, manufacturing techniques of small-scale products have been improved. As a result, precise measurement is required of small inside diameters, for example, of engine nozzles. However, an in situ measurement and measurement system for small-sized products has yet to be fully established. In this research, a contactless technique to measure small inside diameters is proposed. This new method uses tandem low-coherence interferometry and an optical fiber cut at an angle of 45°. This optical fiber is up to 30 μm in diameter and is used as a probe. Our objective is to measure holes as small as 50-μm inside diameter with an accuracy of 100 nm. In the present paper, we report on the measurement principle, calculate the measurement uncertainty and show that experimental measurements can be obtained of small-size holes up to 300-μm inside diameter with an accuracy of 100 nm.
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Schmeltzer, D. "PAIRING OF HOLES INDUCED BY MAGNETIC INTERACTIONS." International Journal of Modern Physics B 02, no. 05 (October 1988): 803–10. http://dx.doi.org/10.1142/s0217979288000627.
Повний текст джерелаАнотація:
We consider a planar Hubbard model with three sites per primitive cell. This model is mapped into a magnetic Hamiltonian. The charged holes interact via the magnetic interaction. The effect of this interaction is to create a magnetic background for the holes. Defining new quasi-particles we find that the many-body interaction becomes attractive and gives rise to conventional superconductivity. At large hole concentrations the critical temperature is determined by the antiferromagnetic exchange between copper-copper. In addition, the Increase of hole concentration reduces the exchange coupling which vanishes at some critical values. At small hole concentrations the critical temperature is determined by the Bose Einstein condensation temperature.
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EBLEN, B. SHAWN, MARK O. WALDERHAUG, SHARON EDELSON-MAMMEL, STUART J. CHIRTEL, ANTONIO DE JESUS, ROBERT I. MERKER, ROBERT L. BUCHANAN, and ARTHUR J. MILLER. "Potential for Internalization, Growth, and Survival of Salmonella and Escherichia coli O157:H7 in Oranges." Journal of Food Protection 67, no. 8 (August 1, 2004): 1578–84. http://dx.doi.org/10.4315/0362-028x-67.8.1578.
Повний текст джерелаАнотація:
Internalization potential, survival, and growth of human pathogens within oranges were investigated in a series of laboratory experiments. Submerging oranges into dye solutions at various temperature differentials was used to assess internalization potential. Conditions in which dye internalization was observed were further studied by applying Escherichia coli O157: H7 or Salmonella onto the stem scar, subjecting the oranges to a temperature differential, juicing, and measuring numbers of pathogens in the resulting juice. Pathogens for growth and survival studies were applied to or injected into simulated peel punctures. Oranges with small peel holes of selected sizes were also placed into solutions containing these pathogens. Bacterial survival was also evaluated in orange juice at 4 and 24°C. Oranges internalized pathogens at a frequency of 2.5 to 3.0%, which mirrored dye internalization frequency (3.3%). Pathogens were internalized at an uptake level of 0.1 to 0.01% of the challenge applied. Bacteria grew within oranges at 24°C, but not at 4°C. Thirty-one percent of oranges with 0.91-mm surface holes showed pathogen uptake, whereas 2% of oranges with 0.68-mm holes showed pathogen uptake. Pathogens added to fresh orange juice and incubated at 24°C declined 1 log CFU/ml within 3 days. These results suggest that internalization, survival, and growth of human bacterial pathogens can occur within oranges intended for producing unpasteurized juice.
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Bikbova, Guzel, Toshiyuki Oshitari, Takayuki Baba, Shuichi Yamamoto, and Keisuke Mori. "Pathogenesis and Management of Macular Hole: Review of Current Advances." Journal of Ophthalmology 2019 (May 2, 2019): 1–7. http://dx.doi.org/10.1155/2019/3467381.
Повний текст джерелаАнотація:
Macular hole has been believed to be a disorder of vitreomacular interface, which forms as a result of abnormal vitreous traction from incomplete vitreous detachment. However, our recent studies demonstrated that dynamic forces, caused by mobile posterior cortical vitreous with fluid currents, exist already at early stages of macular hole development. Therefore, in eyes with flexible vitreous, the contributions of tractional forces due to vitreous shrinkage are unlikely. These facts indicate that in the development of idiopathic macular holes, there is a greater contribution of dynamic forces than has been previously reported. This review also evaluates the recent findings in the assessment of the idiopathic macular holes and the recent therapeutic strategies for optimal management. Inner limiting membrane is considered to improve anatomical closure rate; however, it is still questionable if peeling is necessary in holes less than 250 µm. There are plenty of publications indicating that in the management of small and medium size hole (less than 400 µm), use of long-lasting gas and face-down position is not always required; however, it may be necessary for the treatment of large holes. Ocriplasmin and expansile gas had been reported to be successful for management of small- and medium-sized holes and vitreomacular attachment.
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Sosorev, Andrey Yu. "Walking around Ribosomal Small Subunit: A Possible “Tourist Map” for Electron Holes." Molecules 26, no. 18 (September 9, 2021): 5479. http://dx.doi.org/10.3390/molecules26185479.
Повний текст джерелаАнотація:
Despite several decades of research, the physics underlying translation—protein synthesis at the ribosome—remains poorly studied. For instance, the mechanism coordinating various events occurring in distant parts of the ribosome is unknown. Very recently, we suggested that this allosteric mechanism could be based on the transport of electric charges (electron holes) along RNA molecules and localization of these charges in the functionally important areas; this assumption was justified using tRNA as an example. In this study, we turn to the ribosome and show computationally that holes can also efficiently migrate within the whole ribosomal small subunit (SSU). The potential sites of charge localization in SSU are revealed, and it is shown that most of them are located in the functionally important areas of the ribosome—intersubunit bridges, Fe4S4 cluster, and the pivot linking the SSU head to its body. As a result, we suppose that hole localization within the SSU can affect intersubunit rotation (ratcheting) and SSU head swiveling, in agreement with the scenario of electronic coordination of ribosome operation. We anticipate that our findings will improve the understanding of the translation process and advance molecular biology and medicine.
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Zhao, Jin Fang, Li Yang Xie, Jian Zhong Liu, and Qun Zhao. "Modified Analytical Method for Stress Intensity Factor Calculation of Infinite MSD Plate Containing Multiple Holes." Advanced Materials Research 118-120 (June 2010): 269–73. http://dx.doi.org/10.4028/www.scientific.net/amr.118-120.269.
Повний текст джерелаАнотація:
Multiple site damage (MSD) is the occurrence of small fatigue cracks at several sites within aging aircraft structures. Focusing on this typical structure, an analytical method for calculating the stress intensity factor (SIF) of an infinite plate containing multiple holes was introduced in this paper. The properties of complex variable functions are used to evaluate the stress function. The approximate superposition method is applied to solve SIF problems on multiple holes. Some numerical examples of radial cracks appearing at the boundary of two circular holes are examined by this method. By comparing the analytical and finite analysis results it was realized that the analytical results are accurate and reliable. This modified analytical method is easier to apply than traditional analytical method and can provide SIF solutions for an infinite plate containing multiple holes.
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Goedbloed, Hans, and Rony Keppens. "The Super-Alfvénic Rotational Instability in Accretion Disks about Black Holes." Astrophysical Journal Supplement Series 259, no. 2 (April 1, 2022): 65. http://dx.doi.org/10.3847/1538-4365/ac573c.
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Abstract The theory of instability of accretion disks about black holes, neutron stars, or protoplanets is revisited by means of the recent method of the Spectral Web. The cylindrical accretion disk differential equation is shown to be governed by the forward and backward Doppler-shifted continuous Alfvén spectra Ω A ± ≡ m Ω ± ω A , where ω A is the static Alfvén frequency. It is crucial to take nonaxisymmetry (m ≠ 0) and super-Alfvénic rotation of the Doppler frames (∣mΩ∣ ≫ ∣ω A∣) into account. The continua Ω A + and Ω A − then overlap, ejecting a plethora of super-Alfvénic rotational instabilities (SARIs). In-depth analysis for small inhomogeneity shows that the two Alfvén singularities reduce the extent of the modes to sizes much smaller than the width of the accretion disk. Generalization for large inhomogeneity leads to the completely unprecedented result that, for mode numbers ∣k∣ ≫ ∣m∣, any complex ω in a wide neighborhood of the real axis is an approximate “eigenvalue.” The difference with genuine eigenmodes is that the amount of complementary energy to excite the modes is tiny, ∣W com∣ ≤ c, with c the machine accuracy of the computation. This yields a multitude of two-dimensional continua of quasi-discrete modes: quasi-continuum SARIs. We conjecture that the onset of 3D turbulence in magnetized accretion disks is governed not by the excitation of discrete axisymmetric magnetorotational instabilities but by the excitation of modes from these two-dimensional continua of quasi-discrete nonaxisymmetric SARIs.
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Barišić, S., and I. Batistić. "STRONG ELECTRON-PHONON COUPLING AND THE ORTHORHOMBIC TO TETRAGONAL TRANSITION IN La2CuO4." International Journal of Modern Physics B 02, no. 05 (October 1988): 827–36. http://dx.doi.org/10.1142/s0217979288000640.
Повний текст джерелаАнотація:
It is proposed that the main contribution to the electron-photon coupling in ionic metals arises from the deformation induced variation of the crystal field on the ionic sites which are involved in conduction. The latter are assumed here to be the oxygen sites in the CuO 2 planes of the layered metal oxides. The coupling of holes on those sites to the tilting mode of the La 2 CuO 4 lattice is investigated in detail. Although the coupling is quadratic in small tilting displacement the large value of the corresponding coupling constant explains the destabilization of the tilted (orthorhombic) La 2 CuO 4 lattice on increasing the hole concentration. It is shown that the holes are suppressing the tilt locally, creating the regions of the tetragonal please, as observed recently in the photogeneration experiments. The stability of the corresponding small polarons (tiltons) is discussed in detail.
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Ribas, Guilherme C., Albert L. Rhoton, Oswaldo R. Cruz, and David Peace. "Suboccipital burr holes and craniectomies." Neurosurgical Focus 19, no. 2 (August 2005): 1–12. http://dx.doi.org/10.3171/foc.2005.19.2.2.
Повний текст джерелаАнотація:
Object The goal of this study was to delimit the external cranial projection of the transverse and sigmoid sinuses, and to establish initial strategic systematized burr hole sites for lateral infratentorial suboccipital approaches based on external cranial landmarks particularly related to the lambdoid, occipitomastoid, and parietomastoid sutures. Methods The external cranial projection of the transverse and sigmoid sinuses was studied through their external outlining obtained with the aid of multiple small perforations made from inside to outside along the inner margins of the sinuses of 50 paired temporoparietooccipital regions in 25 dried adult human skulls. The burr hole placement was studied by evaluating the supratentorial, over-the-sinuses, and infratentorial components of 1-cm-diameter openings made at strategic sites identified in the initial part of the study, which was performed in another 50 paired temporoparietooccipital regions. The asterion and the midpoint of the inion–asterion line were found to be particularly related to the inferior half of the transverse sinus; the transverse and sigmoid sinuses' transition occurs 1 cm anteriorly to the asterion across the parietomastoid suture, and the most superior part of the sigmoid sinus is located anteriorly to the occipitomastoid suture, with its posterior margin crossing this suture posteriorly to the most superior aspect of the mastoid process, which is located at the most superior level of the mastoid notch. Burr holes made at the midpoint of the inion–asterion line, at the asterion, 1 cm anterior to the asterion, just inferiorly to the parietomastoid suture, and over the occipitomastoid suture at the most superior level of the mastoid notch are appropriate to expose the inferior half of the transverse sinus at its midpoint, the inferior half of the transverse sinus at its most lateral aspect, the transverse and sigmoid sinuses' transition, and the posterior margin of the basal aspect of the sigmoid sinus, respectively. Conclusions These findings allow an estimation of the transverse and sigmoid sinuses' external cranial projection. The asterion and the most posterior part of the parietomastoid suture constitute a suitable initial burr hole site at which to perform an upper or asterional suboccipital craniectomy to expose the superior aspect of the cerebellopontine angle (CPA). The occipitomastoid suture at the most superior aspect of the mastoid notch constitutes an adequate initial burr hole site at which to perform a basal suboccipital craniectomy to expose the lower portion of the CPA. The sites can be used together as initial burr hole sites to perform wide suboccipital exposures, because they already constitute natural infratentorial lateral limits.
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Irwin, A. J., and P. M. Render. "The influence of simulated missile warhead fragment damage on the aerodynamic characteristics of two-dimensional wings." Aeronautical Journal 117, no. 1194 (August 2013): 823–37. http://dx.doi.org/10.1017/s0001924000008472.
Повний текст джерелаАнотація:
AbstractThe paper describes a method of representing damage on a wing due to multiple warhead fragments, and investigates two of the key variables: fragment impact density and hole diameter. The aerodynamic effects of the damage were quantified by wind-tunnel tests on a two-dimensional wing at a Reynolds number of 5 × 105. The wing was of hollow construction with leading and trailing-edge spars. In all of the cases tested, simulated fragment damage resulted in significant lift losses, drag increases and pitching moment changes. Increasing fragment density or hole size resulted in greater effects. To a first order approximation, both lift and drag increments at a given incidence were related to the percentage wing area removed. Surface flow visualisation showed that low fragment densities and small damage sizes resulted in a complex flow structure on the surface of the wing. This was made up of boundary-layer growth between the damage holes, attached wakes from the forward damage holes and separated surface flow over the rear of the wing. For these cases, individual hole patterns showed similar flow mechanisms to those seen for larger scale gunfire damage cases. Increased fragment density and hole size resulted in upper surface flow separation at the first row of holes. Behind this separation, the flow was attached and consisted of the combined wakes from the forward damage holes. Investigations into the influence of internal model structure indicated that trends in coefficient changes were similar for both hollow and solid wings. However, the magnitudes of the effects were found to be smaller for hollow wings than for solid wings.
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Boyd, Michael C., Paul Steinbok, and Peter L. Cooperberg. "Intraoperative Localization of Intracranial Lesions with Real Time Ultrasound." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 12, no. 1 (February 1985): 31–34. http://dx.doi.org/10.1017/s0317167100046540.
Повний текст джерелаАнотація:
ABSTRACT:High resolution ultrasound has been used intraoperatively on forty-five patients with various intracranial lesions. The technique is quickly and easily carried out under sterile conditions in the operating room. Successful localization of both primary and metastatic tumors of various sizes, depths and consistencies have been made prior to extirpation or biopsy. Several of the biopsies were done through small burr holes. Arteriovenous malformations, abscesses, bone fragments from trauma, gliotic epileptic foci and ventricles for shunt placement have been readily found. No significant complications have been encountered. A new technique for localizing superficial lesions is described. An overall reduction in operating time and unnecessary trauma to the patient has resulted from more accurate intraoperative localization of intracranial lesions with real time ultrasound.
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Sookhaki, Saeed, Sedigheh Sina, Mehrnoosh Karimipourfard, Mehrosadat Alavi, and Fereshteh Khodadadi Shoushtari. "DESIGN AND FABRICATION OF A PEDIATRIC THYROID PHANTOM FOR USE IN RADIO-IODINE UPTAKE MEASUREMENT, IMAGE QUALITY CONTROL AND DOSIMETRY." Radiation Protection Dosimetry 198, no. 4 (March 2022): 238–45. http://dx.doi.org/10.1093/rpd/ncac027.
Повний текст джерелаАнотація:
Abstract Estimating internal contamination from 131I for children in nuclear accidents is a crucial subject in the radiation protection field. Throughout this paper, an urgent and simple method was proposed for measuring 131I inside the pediatric thyroid gland by constructing a neck and thyroid phantom. For this purpose, CT scan images of healthy child’s thyroids were obtained, and the sizes of different parts were determined by a 3D slicer image processing software. Girls with the body surface area between 0.95 and 1.05 were involved in this study. The fabricated phantom is composed of 5 cylindrical slabs of 2-cm thickness, and several small holes were constructed for TLD dosemeters near the thyroid gland and all other parts of the neck. The phantom was constructed utilizing a 3D printer with acrylonitrile butadiene styrene plastic. The thyroid phantom was filled with radioiodine-131, and calibration curves were plotted for contamination estimation. A nodular thyroid phantom was also constructed. The nodular phantom or the resolution phantom has 4 removable parts containing cylindrical holes with diameters of 3, 6, 9 and 12 mm. These holes on the thyroid glands can be filled with different activities of radionuclides to serve as hot and cold spots for quality control of nuclear medicine images. The results show that the designed phantom is applicable in different fields such as nuclear image quality and resolution tests, dosimetry and iodine thyroid uptake estimation in nuclear medicine departments, and nuclear emergency monitoring.
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Woukeng, Jean Louis. "Σ-convergence of nonlinear monotone operators in perforated domains with holes of small size". Applications of Mathematics 54, № 6 (8 листопада 2009): 465–89. http://dx.doi.org/10.1007/s10492-009-0030-8.
Повний текст джерела
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Ford, H. C., Z. I. Tsvetanov, L. Ferrarese, and W. Jaffe. "9.1. HST detections of massive black holes in the centers of galaxies." Symposium - International Astronomical Union 184 (1998): 377–84. http://dx.doi.org/10.1017/s0074180900085284.
Повний текст джерелаАнотація:
After correcting spherical aberration in the Hubble Space Telescope in 1993, the central masses of galaxies can be measured with a resolution 5 to 10 times better than can be achieved at the best terrestrial sites. This improvement in resolution is decisive for detecting the gravitational signature of massive black holes in galaxy nuclei. The discovery of small (r ~ 100–200 pc) rotating gaseous and stellar disks in the centers of many early-type galaxies provides a new and efficient means for measuring the central potentials of galaxies. Concomitantly, VLBI observations of H2O masers in the nuclei of NGC 4258 and NGC 1068 revealed exquisite Keplerian rotation curves around massive black holes at radii as small as 0.1 pc. Recent terrestrial K-band measurements of the proper motions of stars in the cluster at the center of the galaxy provide irrefutable evidence for a black hole with a mass of 2.7 × 106M⊙. At the time of this symposium, the presence of central massive black holes has been established in 12 galaxies. The evidence suggests that there are massive black holes in the centers of all AGNs and in most, if not all, nucleated galaxies. The present data show at best a weak correlation between black hole mass and bulge luminosity.
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Chen, Wen-Shan, Chien-Min Cheng, Da-Huei Lee, Chun-Lin Ciou, Wei-Syun Sin, and Guang-Yuan Cai. "Small-Size Meandered Loop Antenna for WLAN Dongle Devices." International Journal of Antennas and Propagation 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/897654.
Повний текст джерелаАнотація:
This paper proposes a loop-type USB dongle antenna, which is fabricated on a 1.6 mm thick FR-4 substrate for WLAN band systems. The front side of substrate consists of a 50-ohm coaxial line and a multiarm monopole antenna, while the back side has a meandered loop antenna connected to the ground by two via holes. The meandered loop resonates half-wavelength mode at about 2.4 GHz and its higher modes. The higher modes excited by the multiarm monopole form the 5.2 GHz frequency band. The bandwidth of the antenna covers the IEEE802.11 a/b/g WLAN applications. The overall dimensions of the antenna of 30 × 13.75 × 1.6 mm3with an antenna area of 7.5 × 13.75 mm2and a planar structure are exactly suitable for applying in dongle devices. The measured results of radiation patterns, antenna gain, and radiation efficiency are also proposed and discussed in the paper.