Uniform Fill Research Articles

Shaping ability of novel nickel-titanium systems in printed primary molars.

Manual or mechanized instruments can be used for root canal preparation. Manual instrumentation using K-files is widely used in primary teeth, but there are many limitations. Mechanized root canal preparation can lead to easy access to all canals, decrease instrumentation time, and result in more funnel-shaped root canals, resulting in a more predictable uniform paste fill. This study aimed to evaluate the shaping ability and instrumentation time of VDW.ROTATE™ and EdgeTaper Platinum™ during the preparation of resin-printed primary molars. Hand K-files were used as a reference for comparison. Sixty-six resin-based maxillary second primary molars, obtained from extracted tooth cone-beam computed tomography (CBCT) image and printed on a three-dimensional printer, were divided into three groups: VDW.ROTATE™, EdgeTaper Platinum™, and K-files. The specimens were scanned using CBCT imaging before and after root canal preparation. Images were registered using a dedicated software, and changes (Δ) in the canal area, volume, and untouched canal surface were calculated. Instrumentation time was evaluated. Data were statistically analyzed using the SPSS program. There was no significant difference among the tested file systems for Δ canal volume and area (p > .05). VDW.ROTATE™, however, showed significantly lower untouched canal surface area than other systems in all roots (p < .001). The VDW.ROTATE™ was found to be significantly faster (6.47 ± 0.39 min) than EdgeTaper Platinum™ (7.71 ± 0.73 min) and K-files (8.22 ± 0.72 min), (p < .05). The shaping ability and the instrumentation time were directly influenced by the root canal instrumentation system used during the preparation of resin-printed primary molars, with VDW.ROTATE™ being the faster system and associated with the lower amount of untouched canal surface area.

Evaluating the applicability of conventional CPT-based liquefaction assessment procedures to reclaimed gravelly soils

Gravelly soils are not well represented in current semi-empirical liquefaction procedures, which raises the question of whether state-of-the-practice liquefaction evaluation methods based on sands are applicable to gravelly soils. This paper investigates the applicability of Cone Penetration Test liquefaction triggering and settlement evaluation procedures to case histories of well-graded reclaimed gravelly soil at CentrePort, New Zealand. Sensitivity studies of the liquefaction triggering analysis show the uncertainty in the cyclic demand is larger than the uncertainty in the cyclic resistance within a critical layer. However, the modelling uncertainty over the entire depth of the fill is larger for the cyclic resistance, which can vary by over 50% due to a single material-characterization parameter, i.e., the fines content or soil behavior type index. Sand-based procedures for evaluation of liquefaction-induced settlement are found to be generally applicable to well-graded gravels that have a dominant silty sand fraction in the soil matrix, though they can overestimate the relative density and therefore underestimate post-liquefaction settlement of gravelly soils. The paper emphasizes the importance of soil composition, dominant soil fraction of the soil matrix, and its effects on the soil packing, penetration resistance, and liquefaction resistance in the context of current semi-empirical liquefaction evaluation procedures. • CPT-based liquefaction procedures are applicable to some gravel-sand-silt mixtures • Soil composition and dominating soil fractions are key to liquefaction assessment • FS L is more sensitive to uncertainties in PGA than FC or I c • Use of a constant FC throughout seemingly uniform fill could be problematic • Sand-based methods overestimate D R and underestimate settlement of gravelly soils

Comparative Study on the Cooling Characteristics of Different Fill Layout Patterns on a Single Air Inlet Induced Draft Cooling Tower

To enhance the cooling capacity of a single air inlet induced draft cooling tower (SIDCT), the stepped fill layout pattern is proposed in this paper. A three-dimensional numerical model is established and validated by field measurement data. The cooling capacity of towers equipped with uniform fill and stepped fill is compared under various crosswind velocities (0 m/s–12 m/s) and crosswind angles (0°–180°). The results showed that the ventilation rate of the total tower with stepped fill is increased. Under the studied crosswind velocity and angle, the cooling capacity of the stepped fill tower is superior to the uniform fill tower. After using stepped fill, the mean drop of outlet water temperature rises by 0.29 °C, 0.27 °C, 0.17 °C, 0.10 °C, and 0.19 °C, corresponding to crosswind angles from 0° to 180°. The increment of cooling capacity is the maximum under the crosswind angles of 0° and 45° and is the minimum under the crosswind angles of 90° and 135°. The maximum increased value of N is 0.65 under the crosswind velocity of 4 m/s, 0.85 under 8 m/s, and 0.95 under 12 m/s.

Optimizing sample illumination scanning for reflection and 4Pi tomographic diffractive microscopy

Tomographic diffractive microscopy (TDM) is increasingly gaining attention, owing to its high-resolution, label-free imaging capability. Fast acquisitions necessitate limiting the number of holograms to be recorded. Reconstructions then rely on optimal Fourier space filling to retain image quality and resolution, that is, they rely on optimal scanning of the tomographic illuminations. In this work, we theoretically study reflection TDM, and then the 4Pi TDM, a combination of transmission and reflection systems. Image simulations are conducted to determine optimal angular sweeping. We found that three-dimensional uniform scanning fills Fourier space the best for both reflection and 4Pi configurations, providing a better refractive index estimation for the observed sample.

Random model for radiation shielding calculation of particle reinforced metal matrix composites and its application

The work aimed to calculate the radiation biological shielding performance of particle reinforced metal matrix composite (PRMMCs) using more reasonable model instead of conventional Uniform Filling Model, also attempted to provide a basis for the radiation shielding optimal design of such materials. Firstly, RSA (Random Sequential Adsorption) Model and GRM (Grid Random Model) were established based on MATLAB and Monte Carlo Particle transport program MCNP, and then advantages and disadvantages of them were compared. Later, the influences of metal matrix type, particle (B4C) content, particle shape and particle shape parameters on the biological shielding performance of materials were calculated under different energy neutrons and different thickness shield using random models. Finally, the optimal aspect ratio of regular hexahedral B4C was calculated by Genetic Algorithm combined with MATLAB and MCNP. It indicated that GRM could be applied to radiation shielding calculation of PRMMCs.

One-dimensional theory and simulations of the dynamic Z-pinch

The dynamical formation of a Z-pinch in the strong-shock limit is studied in this paper using one-dimensional (1D) simulations of a two-temperature magnetohydrodynamic model. The classic 1D picture consists of three stages: run-in, reflected-shock, and expansion. The special case of a constant current I and uniform gas fill, which are approximate conditions of the pinch-formation stage in a dense plasma focus, is examined in detail. Time-profiles for the shock-front and piston positions during the run-in stage are compared with some of the commonly used 0D models from the literature. Some practical improvements to these models are presented here and it is shown that this model gives the best agreement with results from the simulations. Maximum compression of the plasma is achieved when the reflected shock from the axis meets the incoming current layer. The ratio of the plasma radius at this time with respect to its initial radius is found from the simulations to be rp/R≈1/8 using 5/3 for the adiabatic coefficient γ. The pressure and temperature of the compressed plasma are found to peak a short time after maximum compression due to the inability of the reflected shock to completely stagnate the incoming plasma driven by the converging current layer. The variation of the results with a finite dI/dt and for different values of γ is presented.

Contrastive analysis of cooling performance between a high-level water collecting cooling tower and a typical cooling tower

A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.

Impact mechanism of different fill layout patterns on the cooling performance of the wet cooling tower with water collecting devices

This paper deals with the impact mechanism of different fill layout patterns on the cooling performance of the wet cooling tower with water collecting devices (WCTWCD). A 3D numerical model for the WCTWCD is established and validated. The non-uniform layout fill for the WCTWCD is firstly proposed and analyzed. The differences of the performance parameters caused by the different fill layout patterns are studied. Studies in the paper indicate that the uniform layout fill is not the best layout pattern for the WCTWCD. The non-uniform layout fill can enhance the tower cooling performance in both windless and crosswind conditions. To evaluate the ventilation uniformity inside the tower the circumferential coefficient and the radial coefficient are proposed by the author. The air flow field in the tower with non-uniform layout fill is more stable and uniform. The coupling of the air flow field and the fill consumption in the tower with non-uniform layout fill is more reasonable. At last the comparison of the non-uniform layout fill between the conventional wet cooling tower (CWCT) and the WCTWCD is presented.

Methodology of Uniform Filling Control for Vacuum Casting

Aiming at solving the problem that results from flow instability two-component materials, uneven density and thus affects the product quality in constant pressure casting stage. Based for theory of polymer materials and hydrodynamic, establishing mathematic model of filling stage and proposing a uniform filling strategy through analysis of geometric characteristics of different mold, set pressure regulation curve in order to ensure uniform filling and stable flow for two-component materials in pressure casting stage. The experiment shows that the proposed method can actually ensure uniform filling, but also eliminate the product defects such as insufficient injection and burr, thus presenting a feasible solution to the problem of flow instability two-component materials and uneven density.

Analysis of coupled-bunch instabilities for the NSLS-II storage ring with a 500 MHz 7-cell PETRA-III cavity

The NSLS-II storage ring is designed to operate with superconducting RF-cavities with the aim to store an average current of 500mA distributed in 1080 bunches, with a gap in the uniform filling for ion clearing. At the early stage of the commissioning (phase 1), characterized by a bare lattice without damping wigglers and without Landau cavities, a normal conducting 7-cell PETRA-III RF-cavity structure has been installed with the goal to store an average current of 25mA. In this paper we discuss our analysis of coupled-bunch instabilities driven by the Higher Order Modes (HOMs) of the 7-cell PETRA-III RF-cavity. As a cure of the instabilities, we apply a well-known scheme based on a proper detuning of the HOMs frequencies based upon cavity temperature change, and the use of the beneficial effect of the slow head–tail damping at positive chromaticity to increase the transverse coupled-bunch instability thresholds. In addition, we discuss measurements of coupled-bunch instabilities observed during the phase 1 commissioning of the NSLS-II storage ring. In our analysis we rely, in the longitudinal case, on the theory of coupled-bunch instability for uniform fillings, while in the transverse case we complement our studies with numerical simulations with OASIS, a novel parallel particle tracking code for self-consistent simulations of collective effects driven by short and long-range wakefields.

Agricultural image target segmentation based on fuzzy set

Target objects are direct characteristics of image description, but there are significant limitations, including the image being sensitive to changes in global illumination, etc., which lead to lack direct descriptive ability for objects in an image. Image target segmentation is one of the primary image processing operations, which means it is the first operation of the processing of an image. For the segmentation of a target area from the image, there are two kinds of existing methods. One method is to manually remove the obstructions to be a uniform color fill or outline its contours; and another way is to use the shortest path algorithm or the expansion of biology technique to extract optimal edges. For an image with unclear target boundaries and background, it is very necessary to eliminate the interfering information by transforming the interference information into fuzzy sets. In this paper, to solve the complex background images and the image target segmentation error, considering the dominance on image processing of fuzzy sets, the maximum fuzzy correlation criterion is proposed. Image is converted to a fuzzy domain, and then the maximum fuzzy correlation criterion is calculated. It is important to optimize the image maximum fuzzy membership function. Finally, experiment on leaf and fruit agricultural images, the results show that more edge details can be detected by fuzzy sets.

New Media for 1-pass Printing Applications

PageWide technology is an inkjet breakthrough that dramatically increases printing speed. The speed increases comes with some integration challenges. All of the ink is laid down in a single pass, so there is heightened sensitivity to missing nozzles, aerodynamics, and ink flux. Media is a key enabler for delivering customer requirements. In the CAD and GIS market, productivity is critical. With speeds up to 10x traditional inkjet, drytime and handleability are risk areas. HP's ColorPro technology enables excellent print quality with high Kod and saturated color, but with less ink. This helps both dry time and cost per copy. In the retail graphics and posters market, large uniform area fills are required, which is a challenge for 1-pass page-wide technology. HP's Production Poster technology has specially developed coating that tunes the dot size to deliver vibrant colors, while helping to hide missing nozzles, eliminating printing defects, and improving handleability. The result is a complete system where the ink, printer and media work together to deliver print quality at speeds not achievable with scanning inkjet technology.

Laser beam profile modulation for microstructure control in laser cladding of an NiCrBSi alloy

A circular laser beam with a variable intensity profile was used to investigate the effects of beam intensity profile shaping on the microstructure formation within laser clad layers of an NiCrBSi type corrosion and wear resistant alloy. The raw beam profile output of a high power, fibre delivered laser was manipulated using a variable beam profile modulator. The beam profiles generated took the form of a focussed annular ring with a uniform intensity central fill. The relative intensities of the annular ring and central fill were varied by an adjustment of the optical elements in the variable beam profile modulator. Three of the generated beam profiles were used in the laser cladding of single track deposits of an NiCrBSi based corrosion and wear resistant alloy on Cr5 steel. The microstructure throughout the laser clad layers was examined using XRD, SEM and EDS. It was found that the variations in the scale and distribution of hard phases in the microstructure through the depth of the clad layer can be controlled by varying the laser beam profile. Using a traditional top-hat type beam profile, the microstructure varied from very coarse in the lower part of the clad layer to fine in the upper part. Creating beam profiles with a preferentially greater intensity at the outer edge than at the centre allowed clad layers to be produced with greater microstructural homogeneity throughout the depth of the layer and encouraged the growth of comparatively larger hard dendrite phases near the surface of the clad layer.

Display-wide influences on figure–ground perception: The case of symmetry

Past research has demonstrated that convex regions are increasingly likely to be perceived as figures as the number of alternating convex and concave regions in test displays increases. This region-number effect depends on both a small preexisting preference for convex over concave objects and the presence of scene characteristics (i.e., uniform fill) that allow the integration of the concave regions into a background object/surface. These factors work together to enable the percept of convex objects in front of a background. We investigated whether region-number effects generalize to another property, symmetry, whose effectiveness as a figure property has been debated. Observers reported which regions they perceived as figures in black-and-white displays with alternating symmetric/asymmetric regions. In Experiments 1 and 2, the displays had articulated outer borders that preserved the symmetry/asymmetry of the outermost regions. Region-number effects were not observed, although symmetric regions were perceived as figures more often than chance. We hypothesized that the articulated outer borders prevented fitting a background interpretation to the asymmetric regions. In Experiment 3, we used straight-edge framelike outer borders and observed region-number effects for symmetry equivalent to those observed for convexity. These results (1) show that display-wide information affects figure assignment at a border, (2) extend the evidence indicating that the ability to fit background as well as foreground interpretations is critical in figure assignment, (3) reveal that symmetry and convexity are equally effective figure cues and, (4) demonstrate that symmetry serves as a figural property only when it is close to fixation.

The Role of Symbol Form and Legend Design in Proportional Point Symbolised Maps: An Experimental Study in Thematic Map Design

Point symbols are the most commonly used proportional symbols in thematic mapping. Traditionally two types of symbols have been in use in this category proportional squares and circles. These studies have reported malfunctioning of these symbol forms in terms of the errors reflected in response outputs of the magnitudes both in absolute and relative modes when these are read from the symbols placed in map environments. This malfunctioning of the symbol among other factors was ascribed to the type and design of symbol form and the legend provided on these maps. This paper examines the deficiencies in symbol form design of proportional circles and squares together with the existing design practices of legend design. An effort will also be made to improve symbol form by (1) adding (a) uniform gray area fills (b) graded gray area fills in the open circle and square form together with (2) an improvement in legend deign and its organisation. These design improvements will be tested experimentally by measuring the resulting improvements in terms of both efficiency and effectiveness of visual information processing. The experimental results have shown enhancements in both efficiency and effectiveness in information processing from maps due to proposed design improvement.

A Note on the Uniform Filling Property and Strong Irreducibility

Various separation properties of shift spaces have been defined in the literature. In Boyle et al. (Trans. Am. Math. Soc. 362:4617, 2010), several were put into a chain of strict implications, leaving one open question: Is the uniform filling property (UFP) a strictly weaker condition than strong irreducibility (SI)? We given an example to show that it is, and we show that UFP and SI are equivalent for two-dimensional square filling shifts of finite type.

Injection molding analysis of a needle cover — Optimum filling for gate location design

Injection molding is one of the most popular manufacturing methods for the cost-effective mass production of the plastic parts. Filling analysis of the molten polymer provides useful information to investigate the process conditions to ensure successful replication. To validate appropriate gate location for a NEEDLE COVER, flow fronts and flow stresses for four different gating options and three different design options are analyzed and compared to the field results. Based on the results, the optimum gate location for the minimum flow stresses and uniform fill patterns appears to be at gate 3. Thus it also provides minimum possibility of part warpage throughout PORT HOUSING and NEEDLE HOUSING. The results of analysis on the increased wall thickness, lower melt temperature, and longer injection time indicated that higher melt temperatures were recommended to achieve successful molding. Injecting the polymer at a longer time (1.2 second) leads to a significant increase in flow stresses throughout the part and the increase of wall thickness achieve successful replication of the parts.

Beyond the Special and General Relativity Theories. The Micro-quanta Paradigm

Despite the arbitrary postulate of empty space (which was as arbitrary as the old aether), Albert Einstein obtained through the conceptually powerful postulate of the constancy of light velocity in any reference system, the relativistic equations of motion. The kinematic basis of Special relativity was responsible of several physical paradoxes that accompanied the growing reliability of SR along the XX century. Conversely, in the Micro-quanta paradigm the particle dynamics is directly derived in dynamical conditions from Compton's collisions between particles and the isotropic flux fo of micro-waves filling the space with speed c and energy Eo. When considering the proper Doppler function for waves incident forwards and behind any moving particle, the balance between the two opposite momenta gives the momentum predicted by SR and defines also the rest-mass mi of the particle, which results (equivalence mass-energy) to the energy mic2 = NiEo, where Ni = (si to fo) is the number of quanta colliding simultaneously with the particle during the interaction time to. In the M-Q paradigm the uniform flux fills everywhere the space, so particles “measure” their effective velocity through the momentum of Compton's collisions. The old inertial frames of reference become unnecessary. Any particle moving uniformly in strait-line is shown to collide with micro-quanta without receiving any net force (Principle of inertia). When the particle velocity is not constant and uniform during the interaction time, the local energy density 'o = foEo/c gives rise to the inertial forces. Since two particles immersed in the quantum flux always show mutual shielding, they feel a pushing force which is recognised to be the gravitational force. Thus, the concept of “gravitational mass” is discarded. This inevitably requires to re-examine the fundamentals of General relativity which appears inadequate to explain the recent observations of the accelerating universe achieved through the Ia supernovae measurements. Even the Strong nucleonic force and the Weak force on electrons at very short distances are shown to originate from mutual shielding in the M-Q paradigm. Despite micro-quanta are very small, they do not lose the fundamental characteristics of the quantum waves. The very little quantum energy Eo= hono is coupled to a very little action constant and a very small quantum wavelength lo (of the order of the Planck’s length), so that the number of quanta simultaneously incident on a nucleon is about Nn »1050. This explains why the inertial forces were for three centuries (from Newton up to Einstein) believed to originate from the continuum of space and time, instead of from physical objects.

Molding of C-FRP Plate with Using Induction Heating

Recently, the market for composite materials is dominated by small and medium series production and prototyping [1]. And the VaRTM (Vacuum assisted Resin Transfer Moldings) process is thought to be low cost composite fabrication technique [2]. The preforms in VaRTM are placed on one–side mold and they are sealed by a flexible vacuum bag [3]. The resin is infused into dry fabric formed on a mold near product shape under vacuum pressure and cured in an oven. In general, part defects often arise during the mold filling stage of the process, where a resin is drawn into performs through the use of vacuum. Uniform fill of resin and complete fiber saturation are required for fabricating high quality products [5]. So the resin flow control is extremely required. To solve these problems and short time fabrication, this article investigates the new molding process of C-FRP plate with using the combination of induction heating for quick heating and vacuuming method. To control of the volume fraction easily and to achieve homogeneous impregnation, thermoplastic resin sheet was chosen instead of liquid type. And the C-FRP in a size of 120mm*120mm and the thickness is 6.6mm was able to fabricate by this method.

Evaluation of soil state from SBP and CPT: A case history

The cone pressuremeter test (CPT) is widely used to determine the in situ “state” of cohesionless soils. However, although the CPT is simple, inexpensive, and accurate the subsequent interpretation contains substantial uncertainties even with modern approaches. Self-bored pressuremeters (SBP) have the opposite attributes. Obtaining good SBP data is difficult in sands, but the subsequent evaluation can be rather precise. This paper compares estimates of the in situ state parameter, ψ, from CPT and SBP tests carried out in a uniform hydraulic fill. This case history is unusual in that (i) the fill was well controlled and uniform, (ii) comprehensive laboratory strength data exists, (iii) the CPT was calibrated for the fill in a large chamber, and (iv) good SBP data exist. These SBP and CPT tests are independently analyzed using a calibrated critical state model implemented in a large strain finite element code. The effects of ageing and fabric are considered. The resulting most probable in situ state parameters for the fill from the CPT are close to those derived from the SBP. Although not proof of accuracy (validation) of either test, since ground truth is not known, the results lend support to the adequacy of the interpretation methodology used for both. Further improvements are discussed.