External Cone Research Articles

Non-local tug-of-war with noise for the geometric

This paper concerns the fractional ${\mathrm{\bf p}}$-Laplace operator $\Delta_{\mathrm{\bf p}}^s$ in non-divergence form, which has been introduced in [2]. For any ${\mathrm{\bf p}}\in [2,\infty)$ and $s\in (\frac{1}{2},1)$, we first define two families of non-local, non-linear averaging operators, parametrized by $\epsilon$ and defined for all bounded, Borel functions $u:\mathbb R^N\to \mathbb R$. We prove that $\Delta_{\mathrm{\bf p}}^s u(x)$ emerges as the $\epsilon^{2s}$-order coefficient in the expansion of the deviation of each $\epsilon$-average from the value $u(x)$, in the limit of the domain of averaging exhausting an appropriate cone in $\mathbb R^N$ at the rate $\epsilon\to 0$. Second, we consider the $\epsilon$-dynamic programming principles modeled on the first average, and show that their solutions converge uniformly as $\epsilon\to 0$, to viscosity solutions of the homogeneous non-local Dirichlet problem for $\Delta_{\mathrm{\bf p}}^s$, posed in a domain ${\mathcal{D}}$ satisfying the external cone condition and subject to bounded, uniformly continuous data on $\mathbb R^N\setminus {\mathcal{D}}$. Finally, we interpret such $\epsilon$-approximating solutions as values to the non-local Tug-of-War game with noise. In this game, players choose directions while the game position is updated randomly within the infinite cone that aligns with the specified direction, whose aperture angle depends on ${\mathrm{\bf p}}$ and $N$, and whose $\epsilon$-tip has been removed.

Determination of the resistance of the cylindrical­tubular drill for trenchless laying of underground communications

The determination of the total resistance to penetration of the annular drill into the soil is based on the concept of changing the elastic state of the soil during its compaction, which is defined by the compression modulus of soil deformation. This parameter comprises all the physical and mechanical properties of each type of soil and makes it possible to specify the laws of the normal pressure of penetration resistance acting on the surface of the conical and cylindrical parts of the working body. The proposed theoretical models of processes occurring during penetration of the annular drill into the soil give s an opportunity to determine the influence of the parameters on the resistance force for each working procedure, depending on the physical and mechanical properties of the soil. It has been found that the maximum length of the annular drill is determined for the conditions of soil movement (unplugged condition), which, for example, with a cylinder diameter of 28 mm, is 0.87 m, 1.04 m and 1.16 m respectively for sandy clay, semi-solid loam and tough clay. It is now clear that a 2-fold increase in the internal diameter leads to an increase in the core length of 1.75 times. It has been determined that the two-cone drill does not facilitate passage of soil through itself and it causes soil plugging as well as formation of soil plugs on the frontal planes, which leads to an increase in drag force. Therefore, to provide unplugged conditions during pipe jacking, the drill with a single external cone should be used. The obtained results of the work can be used to substantiate the rational parameters of the working equipment for creating a horizontal borehole in different types of soils.

Immediate loading over lower prosthesis in edentulous mandibles: comparison between two types of prosthetic connection

ABSTRACT Objective: This study evaluated two implant-abutment connection systems under immediate loading of lower prosthesis in edentulous mandibles. Methods: Seventy-two implants placed in 18 patients were analyzed. The parameters evaluated included probing depth, stability of implants and perimplant bone loss, which were measured immediately when installing the prosthesis and after 3 and 6 months. All data underwent statistical analysis (T-Test and ANOVA, 5% significance level). Results: Implants with Morse cone connections showed smaller, statistically significant probing depth values for all periods (0.68/1.19/1.31), when compared to the external hexagon connections (1.08/1.52/1.64). A statistically significant difference was observed between baseline, 3 months (p<0.01 for Morse cone; p<0.001 for external hexagon) and 6 months (p<0.001 for both connections). When periods were considered there was a statistically significant difference in Implant Stability Quotient ISQ values between baseline and 6 months for both prosthetic connections. Conclusion: Immediate loading of the lower prosthesis is a viable option for the treatment of edentulous mandibles and that the external hexagon or Morse cone connections do not interfere with the success of the implants in a short-term evaluation.

Effects of Shock Wave/Boundary-Layer Interaction on Performance and Stability of a Mixed-Compression Inlet

Experiments were conducted to study various kinds of shock wave/boundary layer interaction (SBLI) in an axisymmetric mixed-compression inlet. Further, some of the experimental findings were compared and verified by numerical solutions where possible. A classification of different types of SBLI relevant to the mixed-compression inlets is performed. Interactions of expelled normal shock wave/boundary-layer at subcritical and at buzz condition is investigated using Schlieren and shadowgraph flow visualization as well as unsteady pressure recordings. The data is further compared with the CFD prediction. Interactions of cowl lip reflected oblique shock and the terminal normal shock with the spike boundary-layer at both critical and supercritical operations that leads to shock trains and pseudo-shock phenomena are also studied. In this case numerical simulation results were used to illustrate the flow field. Experimental pressure recordings are used for validation and further discussion. The structure of SBLI flow in an inlet depends highly on the throttling value. For near critical throttling values, interaction of internal compression oblique shocks with boundary-layer and pseudo-shock phenomenon is dominant. Increasing the inlet back pressure pushes normal shock wave out of the inlet duct. Formation of lambda shock due to interaction of separated boundary-layer with normal shock wave is also investigated. The numerical and experimental results show that there exist different kinds of shock wave boundary-layer interactions relevant to the supersonic inlets. Each of these flow interaction phenomena has different effects on the stability and on the performance of the inlet. Interaction of terminal normal shock with internal duct boundary-layer causes pseudo-shock phenomenon that leads to increase of flow distortion and reduction of total pressure recovery. In addition interaction of normal shock wave with external cone boundary-layer causes buzz instability and degrades inlet performance.

Teflon-pad shaping process of circular metal blanks into quasi-cup specimens by theoretical and experimental methods

Teflon-pad shaping process of circular metal blanks into quasi-cup specimens is investigated by theoretical and experimental methods in the quasi-static condition. In the experiments, circular metal sheets are formed into the quasi-cup samples by compressing them between a Teflon-filled die and a rigid punch with desirable shape. To investigate influences of different parameters on the forming progress, 12 rigid punches with different dimensions, two blank material types of aluminum and galvanized iron, three blank thicknesses of 0.6, 1.1 and 1.5 mm, and two Teflon-fillers of PVC and polyurethane are used in several experimental tests. In the analytical part, theoretical deformation models of metal blank and Teflon-filler are introduced and based on energy method, energy absorptions by the blank and Teflon-filler are calculated to derive a theoretical formula for predicting total required energy of the forming process. For this purpose, several energy absorption mechanisms are considered in the blank and filler. Furthermore, predictions by theoretical equation are compared with the corresponding experimental tests to study the verity of the calculated formulas. Theoretical and experimental results illustrate change trend of forming energy with respect to blank thickness. Also, the performed forming tests show that when external cone angle of rigid punch with respect to the horizontal direction increases, forming energy increases nonlinearly; and when the depth of spherical part of rigid punch increases, the probability of rupture increases. Additionally, the experiments demonstrate that there is a direct relationship between the forming energy and flow stress of the blanks. Furthermore, experimental observations illustrate that forming energy of a certain blank with PVC Teflon-filler is higher than that of a similar specimen with polyurethane Teflon-filler; but, the probability of wrinkling decreases when PVC Teflon-pad is used as the filler; and it is advantage of PVC Teflon-filler with respect to polyurethane Teflon.

Research of a sleeve connection of the aircraft pipeline under the influence of dynamic loading

The article presents the results of analyzing the dynamic behavior of a prefabricated single-span pipeline with a tube connection on external cone under the influence of kinematic excitation. Five models of pipelines with different conjugation conditions in tube connection on external cone are described. The results have been obtained by using the finite element method and solving a contact problem of deformable body mechanics. At the first stage amplitude-frequency characteristics for the models of pipeline under consideration are constructed. The result shows the dependence of amplitude-frequency characteristics of the pipeline vibrations on the conjugation conditions in the collecting pipe connection. It was found in the process of research that the resonant frequency of the pipeline varies with introducing admissible gaps in the tube connection on external cone. This change may lead to a shift of the resonance frequency of the pipeline in the range of operating frequencies of the structure that may lead to the destruction of the pipeline. The article also reflects the influence of the external dynamic load on the distribution of contact pressure in the prefabricated tube connection on external cone while passing the resonance frequency. This distribution determines the tightness of connections.

Sealing capability of implant-abutment junction under cyclic loading: a toluidine blue in vitro study.

The aim of the present in vitro study was to evaluate the leakage observed in external hexagon (EH) and cone Morse (CM) tapered implant-abutment connections, using toluidine blue. A total of 60 implants, 30 with a screw-retained EH abutment and 30 with a CM taper internal connection, were used. Toluidine blue was placed into the deepest portion of the internal compartment of the 2 different implant systems, and cyclic loading was applied for each group as follows: 10 samples underwent 1 × 10(6) loading cycles, 10 samples underwent 3 × 10(6) cyclic loading and the least 10 samples underwent 6 × 10(6) cyclic loading. No significant differences between the EH and CM groups were detected when the lowest loading cycles were applied (p = 0.2624), while differences were found when the samples were loaded with 3 x 10(6) and 6 x 10(6) cycles (p = 0.00124), with significantly lower toluidine leakage in CM group. In conclusion, the results of the present in vitro study demonstrated that flow of the toluidine blue to the external portion of the implant-abutment assembly occurred in both types of implant-abutment connections, with very different percentages. Indeed, the CM taper internal connection seems to be more resistant to the leakage of dyes when compared with EH connections.

THE EFFECT OF FLASH BOILING ON THE ATOMIZATION PERFORMANCE OF GASOLINE DIRECT INJECTION MULTISTREAM INJECTORS

In this work the effect of flash boiling on liquid breakup and atomization is first reviewed and then described in detail for the sprays produced by two high-pressure multistream gasoline direct injectors. They were operated at 120 and 200 bar pressure with a fuel injection duration of 0.8 ms into subatmospheric pressures between 1 and 0.1 bar and four temperatures between 20 and 100°C. The sprays were injected into an optically accessed chamber whose temperature and pressure were independently controlled to recreate the conditions found in an engine likely to cause flash boiling. Shadowgraph imaging with a single-shot charge-coupled device camera was applied to obtain images of the spray morphology under a matrix of the above conditions. The interaction between spray streams is particularly complex under flash boiling conditions being a function of the nature of the fuel and the geometry of the injector. In this investigation, three different fuels, regular RON-95 gasoline and single components fuels, n-heptane and iso-octane, were used with two different injectors, one with a 60 degree and the other with a 90 degree nominal external cone angle. In total, five variables were investigated: fuel pressure, ambient pressure, ambient temperature, fuel composition, and injector geometry. Once processed, the recorded images allowed measurement of spray tip penetration and cone angle. Qualitative data on the change in shape of the spray were also available. The results showed that flash boiling has potential to reduce droplet diameters and improve fuel vaporization; however, the associated change in spray shape must be taken into account to avoid problems with spray impingement.

Ultra-Precision Turning Technology of Gold Cone in Fast Ignition

Fast Ignition (FI) attracts much attention owing to its advantages. The fabrication of fast ignition targets is one of the key technologies in FI study. Based on the single point diamond turning (SPDT) technology, Diamond post-turning method is adopted in this paper for the fabrication of gold cone. It not only helps to reduce the end-effect of cone mandrel and consequently improve the coaxiality of internal and external cone surface, but also helps to improve the quality of cone surface and the wall thickness consistency. Besides, the processing parameter of diamond post-turning is experimentally studied in this paper for its effect on the cone surface roughness. According to results, the cone surface roughness is Ra 9.21nm, the wall thickness consistency is 3μm and the cone end surface roughness is Ra5.72nm。

Design and Realisation of a Triple Gas Cladding Head for High-power Active Fibre Lasers

This paper addresses the study, design and realisation of a gas cladding head specifically designed for high-power active fibre lasers. The new cladding head has a coaxial architecture and is able to manage three different gases with three different roles in the coaxial cones. From the central cone to the external cone, the roles of the three gases are as follows:-The first gas (inner gas) is used to protect the focusing lens and control the atmosphere of the molten pool in the cladding to protect and change the final cladding proprieties,-The second gas (central gas) is the powder feeder, and-The last gas (outer gas) is used to shield the work area and increase the process efficiency (to avoid wasting the powder).The new laser cladding head is specifically designed to emphasise the active fibre laser characteristics, such as the small divergence of the fibre beam. The new triple gas head was tested in a long experiment in which the cladding of worn dies used in a hot stamping process for automotive components was repaired. The laser source used in the experiment was an IPG Photonics act ive fibre laser (1000-W maximum power, 400-micron delivery fibre). The die was made of H13 steel and had considerable dimensions (approximately 450x300x150 mm3). The worn features of the dies were previously milled, and the cavities were filled via laser cladding with Stellite 21.

SU-GG-T-50: Evaluating Source Constancy from the Xoft Electronic Brachytherapy System

Purpose: The Xoft Axxent 50 kVp electronic brachytherapy source is currently used to treat a variety of clinical sites including endometrial carcinoma (single‐channel HDR cylinder), accelerated partial breast irradiation (single‐channel HDR balloon), and surface lesions (external cone applicator). Unlike conventional linac‐based dosimetrycontrol systems, the 50 kVp x‐ray source is not monitored during treatment, raising the question of source output stability as a function of absolute dose rate and the spatial constancy of the x‐ray emission. This study evaluates the constancy of the Xoft Axxent 50 kVp electronic brachytherapy source using a pinpoint ion chamber and EBT2 GafChromic film. Materials and Methods: A 0.015 cm3 pinpoint ion chamber was used to verify the constancy of source output during pre‐treatment quality assurance checks using a lucite phantom. The phantom is designed to accept a single channel Xoft applicator and a chamber verification plug. A standard treatment plan was developed to verify source output from a single 50 second dwell position. EBT2 GafChromic film was also used to verify the spatial constancy of a coronal dose plane anterior to the source channel. Results: A total of 37 independent quality assurance measurements were performed using 7 different Xoft sources. The mean pinpoint chamber reading was 10.34 nC with a relative standard error of 2.5%. The ratio of the maximum and minimum chamber reading versus the mean was 1.06 and 0.96, respectively. In comparison, the Xoft on‐board well chamber measures a relative standard error of <1% for the pre‐treatment air‐kerma strength. Conclusions: The output from the Xoft electronic brachytherapy source was monitored using a pinpoint ion chamber during pre‐treatment quality assurance checks. The relative standard error of 37 independent ion chamber readings was 2.5% indicating a relatively stable output across multiple x‐ray tubes in a clinical setting. Research sponsored by the Xoft Corporation.

Sex identification and biomass reconstruction from the cuttlebone of Sepia officinalis

Significant differences were found between males and females in the fragmocone, external cone and widths of the cuttlebone in Sepia officinalis caught in the small-scale trap fishery off Gran Canaria Island (Spain). It is suggested that: (a) differences may depend on morphological adaptations of females for egg laying; (b) cuttlebones represent over 50% of the total cuttlefish caught (which is unrecorded in the fishery); and (c) the relationships between several morphometric measures of the cuttlebone and the mantle length and wet weight may allow more accurate biomass estimations of this species in the fishery.

Theory of diffuse X-ray scattering from an epitaxial layer with quantum rings

A theory of diffuse X-ray scattering from a crystalline layer containing quantum rings (QRs) randomly distributed in lateral directions has been developed. The QR is modeled by a truncated cone with a crater that has the shape of an embedded inverted truncated cone. Reciprocal-space maps of the scattering intensity distribution are obtained by numerical calculations for epitaxial layers containing QRs of various shapes. It is established that the angular distribution of the diffuse scattering significantly depends on the slope of the external cone generatrix, as well as on the crater shape and dimensions.

HYDRODYNAMIC CHARACTERISTICS APPLIED IN DETERMINATION OF THE NEW INLET PORT???S ANGLE FROM A CENTRIFUGAL BLOOD PUMP

A new blood pump is in final phase of clinical evaluation in Institute Dante Pazzanese of Cardiology (IDPC) in Sao Paulo, Brazil. This pump, called Spiral Pump because its spiral thread impeller, was designed to provide the Extracorporeal Circulation (ECC). This system is very reliable but has some inconveniences like limited durability and blood leakage that turn it unviable to be applied as Left Ventricle Assist Device (LVAD). A stainless steel shaft and two ball bearings separated by a plastic spacer hold the SP’s impeller. There is a seal made of silicone rubber to avoid the contact between the blood and the pump’s internal parts. To overcome these problems, many research groups adopted a completely sealless pivot bearing system in their pumps. The pump’s inlet port is located on the top of the external cone. Thinking in build new generations of centrifugal blood pumps that can be used as LVAD, the present work considers studying an inlet port to substitute the original one that is located on the same space used by the top bearing. We compared the hydrodynamic performance of three different inlet design configurations, following the thread orientation, against the thread orientation and neutral. After the three pumps’ performance curves were plotted, the inlet port that shows better values of flow versus pressure head was the configuration that follows the thread orientation. In future works, we will study the mechanical hemolysis to apply this design on SP project. COMPARISON OF CAVITATION INTENSITY BETWEEN TTK-CHITRA AND BJORK-SHILEY MONOSTRUT MECHANICAL HEART VALVES Bryan P Fritz, Keefe B Manning, Varun Reddy, Christopher M Haggerty, Luke H Herbertson, Arnold A Fontaine, Steven Deutsch. Department of Bioengineering, The Pennsylvania State University, University Park, PA.

Determination of the parameters of vector OOE phase matching in LiNbO3

Regularities in changes in the dimension of the ring of the second-harmonic radiation upon the rotation of a LiNbO3 sample have been studied experimentally and confirmed by calculations for the case of vector ooe phase matching. It is shown that the angle δ of the external cone of the second-harmonic radiation in the case of vector ooe phase matching can be determined from the change in the ring dimension upon the rotation of an arbitrarily oriented crystal, provided that second-harmonic radiation is observed.

Some approximation theorems

The general theme of this note is illustrated by the following theorem:Theorem 1.Suppose K is a compact set in the complex plane and 0belongs to the boundary ∂K. Let A(K) denote the space of all functions f on K such that f is holo morphic in a neighborhood of K and f(0) = 0.Also for any givenpositive integer m, let A(m, K) denote the space of all f such that f is holomorphic in a neighborhood of K and f(0) =f′(0) = ... =f(m)(0) = 0.Then A(m, K) is dense in A(K) under the supre mum norm on K provided that there exists a sector W = reiθ; 0≤r≤ δ,α≤ θ≤ βsuch that W ∩ K = 0. (This is the well- known Poincare’s external cone condition). We present various generalizations of this result in the context of higher dimensions replacing holomorphic with harmonic.

Development of Method of Determination of Li/Nb Ratio in LiNbO 3 Crystals

Experimental study confirmed by the calculations is performed for the angular dependences of the size of the ring of second harmonic (SH) radiation at vector OOE-synchronism during rotation of the niobate lithium crystal sample. The possibility to determine the angle of the SH radiation external cone from the observation of changing the size of ring of the SH radiation and from the offset of the ring center from the incident beam during the crystal rotation is shown. The value of this angle is used for determination of the Li/Nb ratio in the crystals.

Repeated eigenvectors and the numerical range of self-adjoint quadratic operator polynomials

LetL(λ) be a self-adjoint quadratic operator polynomial on a Hilbert space with numerical rangeW(L). The main concern of this paper is with properties of eigenvalues on ∂W(L). The investigation requires a careful discussion of repeated eigenvectors of more general operator polynomials. It is shown that, in the self-adjoint quadratic case, non-real eigenvalues on ∂W(L) are semisimple and (in a sense to be defined) they are normal. Also, for any eigenvalue at a point on ∂W(L) where an external cone property is satisfied, the partial multiplicities cannot exceed two.

Jack pine cone quality and cache sizes of red squirrels in southern New Brunswick, Canada

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.

Three types of GABA-immunoreactive cone horizontal cells in teleost retina.

Peroxidase-anti-peroxidase immunocytochemistry, applied on serial semithin epoxy resin sections, was used to examine the localization of endogenous GABA in horizontal cells in the retina of a marine teleost, the dragonet (Callionymus lyra L.). The immunostaining shows that not only the external H1 cone horizontal cells label with antibodies against GABA, but also the H2 and H3 cone horizontal cells in the inner nuclear layer. The distribution of the H1 cells corresponds to that of the single cones. They are square-patterned and in the dorsal retina their density equals 20,000 cells/mm2. The estimated density of the immunostained H2 and the H3 cells in the dorsal retina is 9500 and 1300 cells/mm2, respectively. The H2 and H3 cells are not geometrically arranged, but nearest-neighbor analysis shows that these horizontal cell types do have a very regular disposition. We suggest that GABA is the likely neurotransmitter substance used by all cone horizontal cell types in teleost retina.