Pillar Side Research Articles

Denture Induced Submandibular Hematoma in a Patient on Warfarin

A 79-year-old lady, who was taking warfarin, presented to the Emergency Department with a painless anterior neck swelling, which was associated with hoarseness of voice, odynophagia, and shortness of breath. She first noticed the swelling after she removed her dentures in the evening. On examination, she had an increased respiratory rate. There was a large submandibular swelling at the anterior side of her neck. Upon mouth opening, there was a hematoma at the base of her tongue, which extended to both sides of the tonsillar pillars. The patient was intubated with a video laryngoscope due to her worsening respiratory distress. Intravenous vitamin K and fresh frozen plasma were given immediately. The patient was admitted to the ICU for ventilation and observation. The hematoma subsided after 2 days and she was discharged well.

Differential Expression of Ca2+-buffering Protein Calretinin in Cochlear Afferent Fibers: A Possible Link to Vulnerability to Traumatic Noise.

The synaptic contacts of cochlear afferent fibers (CAFs) with inner hair cells (IHCs) are spatially segregated according to their firing properties. CAFs also exhibit spatially segregated vulnerabilities to noise. The CAF fibers contacting the modiolar side of IHCs tend to be more vulnerable. Noise vulnerability is thought to be due to the absence of neuroprotective mechanisms in the modiolar side contacting CAFs. In this study, we investigated whether the expression of neuroprotective Ca2+-buffering proteins is spatially segregated in CAFs. The expression patterns of calretinin, parvalbumin, and calbindin were examined in rat CAFs using immunolabeling. Calretinin-rich fibers, which made up ~50% of the neurofilament (NF)-positive fibers, took the pillar side course and contacted all IHC sides. NF-positive and calretinin-poor fibers took the modiolar side pathway and contacted the modiolar side of IHCs. Both fiber categories juxtaposed the C-terminal binding protein 2 (CtBP2) puncta and were contacted by synaptophysin puncta. These results indicated that the calretinin-poor fibers, like the calretinin-rich ones, were afferent fibers and probably formed functional efferent synapses. However, the other Ca2+-buffering proteins did not exhibit CAF subgroup specificity. Most CAFs near IHCs were parvalbumin-positive. Only the pillar-side half of parvalbumin-positive fibers coexpressed calretinin. Calbindin was not detected in any nerve fibers near IHCs. Taken together, of the Ca2+-buffering proteins examined, only calretinin exhibited spatial segregation at IHC-CAF synapses. The absence of calretinin in modiolar-side CAFs might be related to the noise vulnerability of the fibers.

Analysis of Rock Burst Risk of Roadway in Lower Seam “Knife Handle” Type Isolated Working Face

In order to determine the influence degree of the main factors in the rock burst risk of the lower seam of the “Knife handle” type isolated coal face rail roadway. In this text, the methods of theoretical analysis, numerical simulation and field measurement are mainly used to study the stress distribution laws during the working face is extending, front abutment pressure and plastic zone of isolated coal pillar, variation of surrounding rock pressure and roadway deformation laws of ore pillar under the isolated coal pillar before and during mining of working face. The results show that two stress concentration areas are formed at the edge of the isolated coal pillar when the working face is not retreating mining, and the stress concentration degree of the upper seam goafs near the 1304 working face is greater. As far as the change of vertical displacement during mining is concerned, the convergence of the rail haulage gateway that its side is much larger than the roof-to-floor, and the deformation near the coal pillar side is larger than that on the side of the isolated pillar, and the maximum displacement deformation is 11 m in front of the coal wall; the rock movement during the advancing of working face is very irregular, and the distance is within 20–40 m front and back the variable face, and the abutment pressure and displacement deformation of the rail haulage gateway change a lot. The value change is obvious and the pressure is intense. Therefore, the distance of advance support is at least 40 m. It is necessary to strengthen the support in the range of 20 m.

3D lattice Boltzmann investigation of nucleation sites and dropwise-to-filmwise transition in the presence of a non-condensable gas on a biomimetic surface

Condensation in the presence of non-condensable gas on a biomimetic pillared subcooled surface with hybrid wettability (with hydrophilic top and hydrophobic side and bottom) is investigated using a newly developed 3D multi-component multiphase lattice Boltzmann model. Three preferred nucleation sites with different surface wettability contrasts are found: (i) at the corner of side and bottom hydrophobic surface; (ii) at the center of the bottom hydrophobic surface, and (iii) on the top hydrophilic surface of the pillar. Influencing factors, such as pillar geometrical parameters, subcooling degree and non-condensable gas concentration, on dropwise-to-filmwise condensation transition are examined. For dropwise condensation on a top hydrophilic pillar surface, the droplet undergoes a two-stage growth pattern from “changing contact line” to “constant contact line”. Non-condensable gas is found to aggregate near the condensing interface in the vapor phase and at corners of pillar side surface and bottom surface. Increasing pillar width or pillar height (with other geometric parameters remained unchanged), as well as decreasing degree of wall subcooling or non-condensable gas concentration, can delay transition from dropwise to filmwise condensation.

Asymmetrical Support Technology for Dynamic Pressure Roadway: A Case Study from Guotun Coal Mine in China

To form a kind of support technology that was universally applicable to all kinds of dynamic pressure roadways, This paper proposes asymmetrical support technology for dynamic pressure roadway. Firstly, the asymmetry characteristics of surrounding rock structure and stress distribution in dynamic pressure roadway were analyzed. The mechanism of asymmetric support technology for dynamic pressure roadway was preliminarily explored. Taking the 1303 dynamic pressure roadway in Guotun Coal Mine as the engineering background, the coal pillar width and support parameter were determined by numerical simulation and theoretical analysis. In the asymmetric support scheme, the roof bolts and the side bolts are respectively Φ20 × 2200 and Φ20 × 2000 mm, the spacing-discharge distance of roof bolts, coal pillar side bolts and coal body side bolts are respectively 800 × 900, 600 × 900 and 800 × 900 mm. Through field observation, the overall deformation of roadway surrounding rock supported by the asymmetric support scheme was not large and the deformation of the roof, coal pillar side and coal body side were basically equal. So, this asymmetric support technology can effectively control the deformation of surrounding rock in dynamic pressure roadway.

The influence of low-energy helium plasma on bubble formation in micro-engineered tungsten

Four different types of micro-engineered tungsten surfaces were exposed to low energy helium plasma, with a planar surface as control. These samples include two surfaces covered with uniform W-coated rhenium micro-pillars; one with cylindrical pillars 1 μm in diameter and 25 μm in height, and one with dendritic conical pillars 4–10 μm in diameter and 20 μm in height. Additionally, two samples with reticulated open-cell foam geometry, one at 45 pores per inch (PPI), and the other at 80 PPI were fabricated with Chemical Vapor Deposition (CVD). The samples were exposed to helium plasma at 30–100 eV ion energy, 823–1123 K temperature, and 5 × 1025 - 2 × 1026 m−2 ion fluence. It is shown that the formation of nanometer-scale tendrils (fuzz) on micro-engineered W surfaces is greatly reduced as compared to planar surfaces. This is attributed to more significant ion backscattering and the increased effective surface area that intercept incident ions in micro-engineered W. A 20% decrease in the average ion incident angle on pillar type surfaces leads to ∼30% decrease in bubble size, down to 30 nm in diameter. W fuzz was found to be absent from pillar sides due to high ion backscattering rates from pillar sides. In foam samples, 28% higher PPI is observed to have 24.7%–36.7% taller fuzz, and 17.0%–25.0% larger subsurface bubbles. These are found to be an order of magnitude smaller than those found in planar surfaces of similar environment. The helium bubble density was found to increase with ion energy in pillars, roughly from 8.2% to 48.4%, and to increase with increasing PPI, from 36.4% to 116.2%, and with bubble concentrations up to 9.1 × 1021 m−3. Geometric shadowing effects in or near surface ligaments are observed in all foam samples, with near absence of helium bubbles or fuzz in deeper layers of the foam.

Interfacial reaction and failure mechanism of Cu/Ni/SnAg1.8/Cu flip chip Cu pillar bump under thermoelectric stresses

Micro-interconnection copper pillar bumps are being widely used in the packaging areas of memory chip and high performance computer due to their high density, good conductivity and low noise. Studying the interfacial behavior of copper pillar bump is of great significance for understanding its failure mechanism and microstructure evolution in order to improve the reliability of flip chip package. The thermoelectric stress test, in-situ monitor, infrared thermography test, and microstructure analysis method are employed to study the interfacial reaction, life distribution, failure mechanism and their effect factors of Cu/Ni/SnAg1.8/Cu flip chip copper pillar interconnects under 9 groups of thermoelectric stresses including 2104-3104 A/cm2 and 100-150℃. Under thermoelectric stresses, the interfacial reaction of Cu pillar can be divided into three stages:Cu6Sn5 growth and Sn solder exhaustion; the Cu6Sn5 phase transformation, exhaustion and the Cu3Sn phase growth; voids formation and crack propagation. The rate of Cu6Sn5 phase transforming into Cu3Sn phase is positively correlated with the current density. There are four kinds of failure modes including Cu pad consumption, solder complete consumption and transformation into Cu3Sn, Ni plating layer erosion and strip voids. An obvious polar effect is observed during the dissolution of Cu pads on the substrate side and the Ni layer on the Cu pillar side. When Cu pad is located at the cathode, the direction of electron flow is the same as that of the heat flow, and it can accelerate the consumption of Cu pad and the growth of Cu3Sn. When Ni layer serves as the cathode, the electron flow can enhance the consumption of Ni layer. Under 150℃ and 2.5104 A/cm2, the local Ni barrier layer is eroded after 2.5 h, which results in the transformation of Cu pillar on the Ni side into (Cux, Niy)6Sn5 and Cu3Sn alloy. The life of Cu pillar interconnection complies well to the 2-parameter Weibull distribution with a shape parameter of 7.78, which is a typical characteristic of cumulative wear-out failure. The results show that the intermitallic growth behavior and failure mechanism at Cu pillar interconnects are significantly accelerated and changed under thermoelectric stresses compared with the scenario under the single high temperature stress.

Surrounding rock control of gob-side entry driving with narrow coal pillar and roadway side sealing technology in Yangliu Coal Mine

Gob-side entry driving can increase coal recovery ratio, and it is implied in many coal mines. Based on geological condition of 10416 working face tailentry in Yangliu Coal Mine, the surrounding rock deformation characteristics of gob-side entry driving with narrow coal pillar is analysed, reasonable size of coal pillar and reasonable roadway excavation time after mining are achieved. Surrounding rock control technology and effective roadway side sealing technology are proposed and are taken into field practice. The results showed that a safer and more efficient mining of working face can be achieved. In addition, results of this paper also have important theoretical significance and valuable reference for surrounding rock control technology of gob-side entry driving with narrow coal pillar under special geological condition.

Dynamics of Microscale Liquid Propagation in Micropillar Arrays.

Understanding the dynamics of microscale liquid propagation in micropillar arrays can lead to significant enhancement in macroscopic propagation modeling. Such a phenomenon is fairly complicated, and a fundamental understanding is lacking. The aim here is to estimate three main parameters in liquid propagation, capillary pressure, average liquid height, and contact angle on the pillar side, through modeling and experimental validation. We show that the capillary pressure is not constant during liquid propagation, and the average capillary pressure is evaluated using its maximum and minimum values. The average liquid height influences the permeability of such a structure, which is challenging to determine as a result of the complicated three-dimensional (3D) meniscus shape. A simple physical model is provided in this paper to predict the average liquid height with less than 7% error. The contact angle on the micropillar side, which has considerable impact on the capillary pressure and the average liquid height, has been debated for a long time. We propose a model to predict this contact angle and validate it against experimental values in the literature. Our findings also indicate that the microscopic motion of the liquid front is significantly affected by the ratio of the pillar height to edge-to-edge spacing, and a correlation is provided for quantification. The proposed models are able to predict the droplet spreading dynamics and estimate spreading distance and time reasonably.

Characterization of Clean after Photoresist Removal from Wafers with Copper Pillars with Lead-Free Solder Caps

Opportunities for developing new and enabling packaging schemes are being pursued as part of device improvement strategies for electronic products. Processes such as embedded technologies in wafer level packaging and 3-D chip architecture schemes open up opportunities for realization of a variety of package configurations. As a result, there are many opportunities to impact both device performance and the processes used to create them. In the area of electroplated solder applications, there has been widespread adoption of copper pillar bumps with lead free solder caps. Solder wetting of only the copper pillars after reflow confines the spread of the solder cap in the x,y plane enabling tighter pitch layouts, while the smaller solder cap still improves the robustness of the interconnection. However, as more data is gathered using this process, one area of growing interest is the characterization of polymer photoresist residue on the side walls of plated copper pillars with lead-free solder caps. As has been seen with other processes including for example, redistribution line (RDL) cleaning processes, cleaning challenges have increased in tighter pitch applications. In RDL, cleaning challenges were increased as cleaning processes that were once taken for granted were now being applied to wafers with 10μm line/space and tighter pitches. Analogies can be found in the tight pitch copper pillar cleans. Typical characterization techniques such as optical microscopy have been used traditionally in the industry as a post process inspection method. Advantages such as ease of use, fast throughput, automated tooling, use of filters to highlight certain defect types, and the ability to non-destructively inspect whole wafers have all contributed to its success in the field. With tighter pitch copper pillar applications, inspection using optical microscopy is challenged in an extreme and it is possible to inspect a clean copper pillar wafer and not see photoresist residue on the copper side walls. This paper will describe wet cleaning processes used today for copper pillar cleans, with special focus on characterization of the Cu pillar and solder side walls. Examples using several different photoresists and copper and solder configurations will be examined. Samples with differing copper/solder bump heights and pitches will be discussed. Cleaning and compatibility results will be shown.

Flooded Two-Phase Flow Dynamics and Heat Transfer With Engineered Wettability on Microstructured Surfaces

Due to excessive droplet feeding, a period of flooding occurs as part of a typical droplet based thermal management cycle. The conventional superhydrophilic surface, which is designed for thin film evaporation because of its highly wettable character, has a limited improvement on the thermal performance during the flooded condition. This paper investigates microstructures which combine micropillars and four engineered wettability patterns to improve the heat dissipation rate during flooding. Using the transient, 3D volume-of-fluid (VOF) model, the bubble behaviors of growth, coalescence, and departure are analyzed within different microstructures and the effects of pillar height and wettability patterns on the thermal performance are discussed. The wettability gradient patched on the pillar's side is demonstrated to promote the bubble's upward movement due to the contact angle difference between the upper and lower interfaces. However, insufficient pulling force results in large bubbles being pinned at the pillar tops, which forms a vapor blanket, and consequently decreases the heat transfer coefficient. When only a patch of hydrophobic material is present on the pillar top, effective pulling forces can be developed to help bubbles in the lower level depart from the pillar forest, since bubble merging between them generates most of the power required to pull the bubbles to the surface. The simulation results, including heat source temperatures and heat transfer coefficients, indicate that a patch of hydrophobic material on the pillar top works best out of all of the cases studied.

A Giant Pleomorphic Adenoma of the Palatine Arch in a 75-Year-Old Man: A Case Report with Review of Literature

ABSTRACT Pleomorphic adenoma (PA) is the most common benign tumor of the salivary glands and has both epithelial and mesenchymal tissues. It most commonly arises from the parotid or submandibular glands. Rarely, it arises from the minor salivary glands. We report here a case of pleomorphic adenoma arising from the soft palate and both sides of anterior tonsillar pillars in a 75-year-old man. This patient was presenting painless slow growing large swelling in the soft palate over 20 years causing mechanical obstruction of airway and food. The entire tumor mass was excised along with overlying mucosa. How to cite this article Swain SK, Sahu MC, Tripathy R. A Giant Pleomorphic Adenoma of the Palatine Arch in a 75-Year-Old Man: A Case Report with Review of Literature. Int J Head Neck Surg 2015;6(1):23-25.

無導坑の超近接トンネルの掘削時挙動に関する研究

In order to clarify the behavior of closely spaced twin tunnels without center pillar during excavation, analysis on the field measurement data obtained at closely spaced twin tunnels construction sites and numerical analysis using 3D and 2D finite different code were carried out. The results show that the influence of the second tunnel excavation on the first tunnel appears mainly as the increase of the sectional forces in support structure at the sidewall on the second tunnel side with the rapid change of the stress in the soil pillar. The load acting on the support structure of both tunnels at the soil pillar side varies depending on the distance between two tunnels, overburden height and deformation modulus of ground, and the support structure may support a load up to full overburden weight in some cases. 併設トンネルの離隔距離をほとんど確保しない超近接トンネルを無導坑で掘削した時の挙動を明らかにするため，これまでに得られている施工時の計測結果の分析を行った．さらに，数値解析により後進坑の切羽通過時における中間地山の応力変化と先進坑の挙動との関係，土被り，離隔距離，地山の変形係数が支保工に作用する荷重に及ぼす影響について検討を行った．その結果，後進坑の掘削による影響は，先進坑の中間地山側の側壁部に大きく現れること，後進坑の切羽通過時には中間地山の応力が急激に変化し，先進坑の断面力が大きく増加すること．中間地山側の支保工に作用する荷重は，土被り，離隔距離，地山の変形係数の影響を大きく受け，支保工に全土被り荷重が作用する場合があることが明らかとなった．

Parallel pathways at the auditory periphery

We should consider the possibility that Low- and High- spontaneous rate (SR) auditory nerve fibers (ANFs) [1] constitute two different parallel pathways at the auditory periphery. The present study used a computational model of the auditory periphery [2] to demonstrate that Low- and High- SR ANFs have contrasting response properties. Anatomical studies suggest that Low- and High- SR ANF types have separate innervation sites (Figure ​(Figure1A)1A) on the same inner hair cell; lower-SR fibers synapse on the modiolar side and high-SR fibers synapse on the pillar side [3]. My hypothesis, prior to modeling the tuning curves (Figure ​(Figure1B),1B), was that Low Spontaneous Rate (Low-SR) fibers have a higher threshold for simulation and thus will have demonstrably sharper frequency selectivity than High-SR fibers. The results of the simulation support this framework; Low-SR ANFs were shown to have sharper frequency tuning (Figure ​(Figure1B)1B) than High-SR ANFs throughout a range of characteristic frequencies (CFs). While Low-SR ANFs have sharper frequency selectivity (Figure ​(Figure1B),1B), High-SR ANFs have finer temporal resolution, as the rate of change of the mean firing rate in High-SR ANFs was well above that of Low-SR fibers in the simulation (Figure ​(Figure1C).1C). It would seem that Low-SR and Medium-SR fibers (i.e. Lower-SR fibers) are optimized for “place theory” frequency coding and High-SR fibers are optimized for “volley-theory” synchronous phase locking. Future modeling efforts might maintain the integrity of these two parallel pathways, optimized for fine spectral (Lower-SR) and fine temporal (High-SR) resolution, by separating rather than summing their respective outputs. Figure 1 Innervation sites (A), tuning curves (B) and temporal response properties for Low- and High- SR ANFs

Sophisticated process for a spin-torque device fabricated from a pillar containing two different ferromagnetic materials separated by a non-magnetic layer

Since several years, devices allowing for spin manipulation in ferromagnetic layers are the subject of intensive research (e.g., Ralph and Stiles (2008) [1]). A pillar with sub-micrometer dimensions fabricated from a stack of various materials containing two or more ferromagnetic layers separated with a spacer very often serves as a core of devices suitable for investigation of spin torque phenomena. Here we describe a reliable fabrication process for such pillars emphasizing precautions which have to be taken to protect pillar side walls from surface conductivity thereby increasing the percentage of the structures revealing magnetic field/current induced switching events.

811 自動車のピラー縦渦とミラー剥離渦の相互干渉

811 自動車のピラー縦渦とミラー剥離渦の相互干渉

Transition from Cassie to impaled state during drop impact on groove-textured solid surfaces

Liquid drops impacted on textured surfaces undergo a transition from the Cassie state characterized by the presence of air pockets inside the roughness valleys below the drop to an impaled state with at least one of the roughness valleys filled with drop liquid. This occurs when the drop impact velocity exceeds a particular value referred to as the critical impact velocity. The present study investigates such a transition process during water drop impact on surfaces textured with unidirectional parallel grooves referred to as groove-textured surfaces. The process of liquid impalement into a groove in the vicinity of drop impact through de-pinning of the three-phase contact line (TPCL) beneath the drop as well as the critical impact velocity were identified experimentally from high speed video recordings of water drop impact on six different groove-textured surfaces made from intrinsically hydrophilic (stainless steel) as well as intrinsically hydrophobic (PDMS and rough aluminum) materials. The surface energy of various 2-D configurations of liquid-vapor interface beneath the drop near the drop impact point was theoretically investigated to identify the locally stable configurations and establish a pathway for the liquid impalement process. A force balance analysis performed on the liquid-vapor interface configuration just prior to TPCL de-pinning provided an expression for the critical drop impact velocity, Uo,cr, beyond which the drop state transitions from the Cassie to an impaled state. The theoretical model predicts that Uo,cr increases with the increase in pillar side angle, α, and intrinsic hydrophobicity whereas it decreases with the increase in groove top width, w, of the groove-textured surface. The quantitative predictions of the theoretical model were found to show good agreement with the experimental measurements of Uo,cr plotted against the surface texture geometry factor in our model, {tan(α/2)/w}(0.5).

Observation of water condensate on hydrophobic micro textured surfaces

We visually observed that a dropwise condensation occurred initially and later changed into a filmwise condensation on hydrophobic textured surface at atmosphere pressure condition. It was observed that the condensate nucleated on the pillar side walls of the micro structure and the bottom wall adhered to the walls and would not be lifted to form a spherical water droplet using environmental scanning electron microscope.

Failure laws of narrow pillar and asymmetric control technique of gob-side entry driving in island coal face

In allusion to the problems of complex stress distribution in the surrounding rock and deformation failure laws, as well as the difficulty in roadway supporting of the gob-side entry driving in the island coal face, 2107 face in Chengjiao Colliery is researched as an engineering case. Through physical mechanical test of rock, theoretical and numerical simulation analyses of rock, the analysis model of the roadway overlying strata structure was established, and its parameters quantified. To reveal the deformation law of the surrounding rock, the stability of the overlying strata structure was studied before, during and after the roadway driving. According to the field conditions, the stress distribution in coal pillar was quantified, and the surrounding rock deformation feature studied with different widths of the pillars in gob-side entry driving. Finally, the pillar width of 4m was considered as the most reasonable. The research results show that there is great difference in support conditions among roadway roof, entity coal side and narrow pillar side. Besides, the asymmetric control technique for support of the surrounding rock was proposed. The asymmetric control technique was proved to be reasonable by field monitoring, support by bolt-net, steel ladder and steel wire truss used in narrow pillar side.

Multi-step ion beam etching of sub-30 nm magnetic tunnel junctions for reducing leakage and MgO barrier damage

We have demonstrated the fabrication of sub 30 nm magnetic tunnel junctions (MTJs) with perpendicular magnetic anisotropy. The multi-step ion beam etching (IBE) process performed for 18 min between 45° and 30°, at 500 V combined ion supply voltage, resulted in a 55 nm tall MTJ with 28 nm diameter. We used a negative tone electron beam resist as the hard mask, which maintained its lateral dimension during the IBE, allowing almost vertical pillar side profiles. The measurement results showed a tunnel magneto-resistance ratio of 13% at 1 kΩ junction resistance. With further optimization in IBE energy and multi-step etching process, it will be possible to fabricate perpendicularly oriented MTJs for future sub 30 nm non-volatile magnetic memory applications.