bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution of Thermal Bridge under the Opening in the Cladding by Means of Support Structure for a Doors Threshold Made of Thermal Insulation Composite Material
Authors: Pospíšil Tomáš , Pěnčík Jan , Matějka Libor , Matějka Libor , Kalužová Alena , Dostálová Darina
Published: December 2012

In the process of sustainable construction is the emphasis placed on saving energy, reducing use of natural resources, increase the life cycle of materials by recycling, etc. Rising energy prices put increasing emphasis of builders and investors to better solution of thermal bridges. Solution can be done using a conventional materials, but also advanced materials meet the requirement of a sustainable construction and a reducing consumption of natural resources and extending of the life cycle of material. An example of such material is the thermal insulation composite material. This new developed material with low coefficient of thermal conductivity below the value of 0.100 W/mK is made of recycled waste polymer and recycled filler in the form of granules from recycled glass. In the paper are compared two variants of solution of thermal bridge under the opening in the cladding. In the first variant a wooden door opening in the perimetral cladding is deposited on a support structure for a doors threshold made of a thermal insulation composite material. In the second variant is used a lower shaped brick block. The variants of different foundation of a wooden door opening are compared in terms of a lowest surface temperature and of a temperature factor of the inner surface fRsi and its critical value fRsi,cr according to ČSN 73 0540-2 and ČSN EN ISO 10211.
Study on Novel Structure of Potassium Borate Hydrate: K(H4B5O10)·2(H2O)
Authors: Liu Hai Xing , Jian Fang Fang , Wang Jing , Zeng Guang , Yue Hui Juan , Tai Xi Shi
Published: December 2012

Numerous stable complexes of boric acid with polyhydroxy compounds, including tartaric, salicylic, citric, malic, and other acids, are known. The structure of some compounds contains polyanion. In this paper, a novel potassium borate hydrate [K(H4B5O10) •2(H2O)] has been synthesized from a solution reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. Orthorhombic, Aba2. a = 11.0781(14) Å b = 11.1780(15) Å c = 9.0508(11) Å α=β=γ=90°. V= 1120.8(2) Å3. Z=4. Rgt = 0.0244, wRref = 0.0623. T= 298 K. The crystal packing is stabilized by O-H...O hydrogen bonds interaction and three dimensional framwork structure is formed. The work is originality and has a new crystallographic structure shape.
Molecular Dynamics Simulation of Microcrack Healing in Copper Nano-Plate
Authors: Wang Mei Fen , Du Guo Jun , Xia Dong Yu
Published: December 2012

The molecular dynamics method is used to simulate microcrack healing in copper nano-plate during heating. During microcrack healing, the tip of microcrack is blunted and deforms to round shape, the microcrack becomes smaller and smaller until it is healed through slip bands emitting from the pre-crack tip and expanding to the top and bottom of the copper nano-plate. The healing time is different in different temperature. The healing processes in different temperature present different slip bands for crack healing. When temperature is below 650K, the healing time decreases dramatically with temperature increase. When temperature is above 650K, the healing time decreases smoothly with temperature increase. The critical temperature of microcrack healing in copper nano-plate without pre-existing dislocations is about 400K.
Microstructures and Photoluminescence of a-Si:H/a-SiNx Multilayers Annealed at Different Temperature
Authors: Song Chao , Guo Yan Qing , Wang Xiang , Song Jie , Huang Rui
Published: December 2012

Series of a-Si:H/a-SiNx multilayers were prepared by very high frequency plasma enhanced chemical vapor deposition system. As-deposited samples were thermally annealed at the various temperatures. The effects of thermal annealing on the properties of luminescence were investigated. The photoluminescence intensity of the film annealed at 600 °C is found to be higher than that of the film without annealing. However, with further increasing the annealing temperature from 600 °C to 800 °C, the photoluminescence intensity of the film rapidly decreases. Fourier transform infrared spectroscopy and Raman-scattering spectroscopy were used to study the changes of the microstructures and bonding configurations. Based on the measurements of structural and bonding configurations, the improved photoluminescence intensity is attributed to the forming of radiative defect states caused by the effusion of hydrogen in the films.
Study on Stability Exponent Apparatus
Authors: Chen Ge Hua
Published: December 2012

The stability index apparatus is presented, which adopts electrochemical principle and microcontroller technology to determine the solution alkalinity of the circulating water processed by CaCO3. Base on it, this apparatus calculates the stability exponent to evaluate whether the measured water is stable, or existing the tendency of fouling or corrosion. The scaling and the corrosion of pipes and equipments are relieved by controlling the quality of the circulating water. This paper presents the new stability exponent apparatus with which the stability of the water quality can be determined accurately and provides the basis for controlling the water quality. The automatic control of water quality is realized by this apparatus with the cooperation of the dosing system, ensuring the circulating water piping to be safe and stable.
A Preparation Method of Diamond Specimens Using an Advanced FIB Microscopy for Micro and Nanoanalysis
Authors: Chen Yi Qing , Tang Feng Zai , Zhang Liang Chi
Published: December 2012

This paper reports the specimen preparation using an advanced dual beam focused ion beam (FIB) technique for bulk polycrystalline diamond (PCD) composites after dynamic friction polishing (DFP). The technique adapted allows for precisely processing diamond materials at the specific polishing track sites of PCD surface, from which large cross-sectional specimens for SEM/EDS/Raman microanalysis could be successfully created. In addition, an in-situ lift-out method was developed to prepare the site-specific HRTEM specimens which were thin enough for imaging the atomic lattice of diamond and for conducting EELS analysis.
In Situ Polymerization and Photophysical Properties of Poly(p-phenylene Benzobisoxazole)/Nano-Sized TiO2 Fibers
Authors: Wang Hu , Liu Ji Ping
Published: December 2012

Poly (p-phenylene benzobisoxazole)/Nano-sized titanium dioxide (PBO/TiO2) composites with different TiO2compositions were prepared through in situ polymerization and the fibers had been successfully spun via dry-jet wet spinning technique. PBO/TiO2composite fibers were characterized by FTIR spectroscopy, Ubbelohde capillary viscometer, TG analyses and so on. Mechanical property of the fibers was investigated before and after UV accelerated aging which being exposed under ultraviolet radiation for up to 100 hours. Results showed that the molecular weight of PBO in the Nano composites was less declined with low content of TiO2; the thermal degradation temperature of PBO/TiO2fibers were at less 10°C higher than that of pure PBO fiber in the atmosphere of N2; The pure PBO had a large deterioration in mechanical properties, and in the initial exposure time tensile strength of fibers dropped slowly after TiO2adding in. From these results, the nano-TiO2had good UV-aging shielding efficiency for PBO fiber.
Preparation of Poly(γ-Glutamic Acid)/Montmorillonite Superabsorbent Nanocomposite
Authors: Wang Xu Man , Zhang Cai Ning
Published: December 2012

Montmorillonite (MMT) was applied as the modifying agent, polyethylene glycol bisglycidyl ether as crosslinking agent, Poly(γ-glutamic acid)/montmorillonite (γ-PGA/MMT) superabsorbent nanocomposite was prepared. The effects of crosslinking agent mass, MMT contents and reaction temperature on the saline water absorbency of the superabsorbent nanocomposites were studied. The experimental results demonstrated that the saline water absorbency of γ-PGA/MMT nanocomposites increased with the increasing of crosslinking agent mass firstly and decreased when the crosslinking agent mass was higher than 0.6g. The saline water absorbency of γ-PGA/MMT nanocomposites increased with the MMT contents up to 7% and decreased as the MMT contents further increased. Moreover, the saline water absorbency of γ-PGA/MMT nanocomposites increased with the reaction temperature firstly, and then decreased when the reaction temperature was higher than 50°C.
Microstructure and Melting Behavior of Rapid Solidified Au-Ag-Ge Alloy
Authors: Cui Da Tian , Liu Wen Hui , Liu Long Fei
Published: December 2012

Rapid solidified Au-Ag-Ge alloy was prepared by the melt spinning method，microstructure and melting behavior of the rapid solidified alloy was investigated by means of SEM, TEM and DSC. DSC results show that liquid temperature of the rapid solidified alloy is about 3～4°C lower than that of the alloy ingot, melting interval is also smaller. Minimum size of 40nm nanocrystalline has formed when the cooling rate is 1.293×106K/sec. Metastable supersaturated precipitated Ge-rich phases have been found at the grain boundaries, a structure mutation was found in the thickness direction of the rapid solidified alloy. Meanwhile, due to the stabilization transition of the supersaturated precipitated phase of the rapid solidified alloy, an exothermic peak has formed in the DSC curve, temperature of the exothermic peak becomes much lower when the cooling rate increases.
Influence of Electrolyte Plasma Treatment on Structure, Phase Composition and Microhardness of Steel Р6М5
Authors: Skakov Mazhin , Rakhadilov Bauyrzhan , Sheffler Michael
Published: December 2012

Microhardness of nitrated and carbonitriding in electrolyte plasma steel Р6М5 surface layers are investigated in the research. It shows perspectiveness of the cutting tool electrolyte-plasma treatment technology. Operating conditions for the technology realization are defined. It was also indicated the desired content of components in saturating mixtures by nitriding and carbonitriding. Comparative research of structure, phase composition of fast-cutting P6M5 steel modified surface layers after electrolyte plasma treatment was carried out by scanning-electron and light microscopy, and X-ray structure analysis methods. The way of electrolytic plasma nitriding in cathodic mode, to provide fast-cutting steels which allows for modification the surface and high kinetic efficiency the process diffusion saturation. It was established that as a result of nitriding and nitrocarburizing in plasma electrolyte has been a significant increase in microhardness in the surface layers of steel Р6M5.
Solving Permutation Flow Shop Scheduling Problems with Job Idle Time in between Two Machines
Authors: Baskar A. , Xavior Anthony M.
Published: December 2012

Finding an optimal sequence in terms of total completion time for processing ‘n’ jobs in ‘m’ processing centers in the shop floor is an important job for a shop floor supervisor. The problem is NP hard as the total number of sequences is (n!) for a permutation flow shop scheduling problem. Starting from Johnson’s Algorithm, many classical Heuristics were proposed in earlier days. After the invention of evolutionary algorithms and Meta Heuristics, finding an optimal sequence becomes comparatively easier. This paper deals with improving one such performance parameter, the make span, in a Permutation Flow Shop Scheduling problem in case of job idle times (though machines are available, jobs are not) observed in between two machines. The case of three machines, n jobs has been analyzed using the well known Taillard bench mark problems by coding in MATLAB R2008a and a new procedure has been proposed.
Research on a Strategy-Oriented Energy Saving and Emission Reduction Performance Management System of the Party and Government Leaders of Counties and Municipalities
Authors: Zhou Jing Kun , Duan Zhong Xian , Yu Bing Cai
Published: December 2012

This article describes a strategy-oriented energy saving and emission reduction performance management system model of the Party and government leaders of counties and municipalities (hereinafter referred to as "the Leaders") consisting of a strategic formulation sub-system of the government of counties and municipalities, a strategy-oriented energy saving and emission reduction performance evaluation entity design sub-system of the Leaders, a strategy-oriented energy saving and emission reduction performance evaluation indicator selection sub-system of the Leaders, a strategy-oriented dynamic circle sub-system of important parts of energy saving and emission reduction performance management of the Leaders, and a strategy-oriented energy saving and emission reduction performance management guarantee sub-system, and give a brief description of main contents and establishment process of every sub-system
Design of Low-Speed Spindle Running on Air Bearings Used on Rotary Viscometer
Authors: Yao Ying Xue , Wang Hong Bo , Zhou Liang
Published: December 2012

A low-speed spindle running on air bearings is presented, it is used on rotary viscometer based on velocity attenuation of rotating cylinder. Principle of spindle is introduced, it is composed of a low speed motor and an air bearing. The low speed motor is a coupling of two motors. Design of the spindle shows the structure of it. Materials of the spindle are selected. The spindle is machined and operation process of it shows it is suitable for driving part of rotary viscometer based on velocity attenuation of rotating cylinder.
The Study on the Ineffective Mechanism of Aluminum Alloy Spot Welding Electrode
Authors: Yu Hui Yong , Zhou Hui Lin , Liu Dan , Hu Jun Hua
Published: December 2012

This study explored the electrode excessive burning reason caused by aluminum resistance spot welding and proposed a new electrode failure mechanism. The test shows that the oxide film of aluminum alloy workpieces causes the contact of non-uniform points between electrode and workpieces and instantaneously leads to a local explosion when setting up an electric circuit, bringing about the plastic deformation of the electrode surface in the local area, which will in turn exacerbate the contact of non-uniform points between electrode and workpieces so as to result in the serious burnout of electrodes under the interaction between local explosions and Cu-Al alloying. Cu-Al alloying and brittle material on the electrode surface caused by the contact of non-uniform points will firstly detach from the surface of electrode under the tearing force of mechanical , so that the electrode surface becomes more uneven.
Effect of Titanium Oxide on Phase Transformation for Low Alloy High Strength Steel Welds
Authors: Chen Cui Xin , Peng Hui Fen , Zhao Pu , Li Yuan Yuan , Yan Liang
Published: December 2012

Aimed at improving mechanical properties of high strength low alloy steel welds, oxides with high melting point and high stability were added into steel liquid. By thermodynamics calculation and thermal simulating technology, phase transformation characteristics of low alloy steel weld with TiO2addition were investigated. The results showed that TiO2added in welds led to the decrease of phase transformation temperature and the wideness of γ→α transformation temperature range. The starting and finishing transformation temperature of ferrite respectively dropped about 311K and 486K on the cooling condition of 373K/s. Moreover, the complex inclusions of TiOx-MnO-SiO2-MnS with spherical shape and 0.67μm mean size formed in weld metal. In addition, only acicular ferrite existed in the titanium oxide added welds. So it was concluded that titanium oxide can effectively be used to control phase transformation and then achieve fine and favorable microstructure.
Effects of Cold Deformation on Precipitation in Fe-18Cr-12Mn-0.48N High-Nitrogen Austenitic Stainless Steel
Authors: Shi Feng , Li Xiao Wu , Qi Yang , Liu Chun Ming
Published: December 2012

The precipitation behaviors were investigated during isothermally aging at 700°C and 800°C after cold compressed by 30% in thickness in Fe-18Cr-12Mn-0.48N high-nitrogen austenitic stainless steel by using optical microscopy (OM), laser scanning confocal microscopy (LSCM) and transmission electron microscopy (TEM). The results show that precipitation morphology in cold-deformed sample is the same as non-cold-deformed sample, which also displays discontinuous cellular way. Cold deformation accelerates the precipitation of M2N phase. The precipitation occurs at not only grain boundaries but also twin grain boundaries in the experimental steel. In cold-deformed sample, besides the long-strip M2N precipitates, intermetallic phase-σ phase owning bct structure and lattice parameters of a=0.8800nm and c=0.4544nm were observed along grain boundaries and inside the grain.
Overview on Developed Functional Plasma Sprayed Coatings on Glass and Glass Ceramic Substrates
Authors: Floristán Miriam , Killinger Andreas , Gadow Rainer
Published: December 2012

For diverse applications in optical, electronic and consumer industries, the use of glass and glass ceramics as substrates for functional coatings is becoming of outstanding interest in order to develop advanced composites. Atmospheric Plasma Spraying (APS) is an adequate technology for the deposition of a wide variety of materials on glasses. Glass and glass ceramics are characterised by their specific thermo physical properties like low or even negative CTE, low heat conductivity and high dimensional stability. Consequently, modified production processes in comparison to the established coating operations on metal surfaces are required regarding the substrate activation methods or a more accurate heat transfer guidance to the substrate by optimized robot trajectories. This paper aims to give an overview of the investigations carried out at the IMTCCC for the development of plasma sprayed layer composites on borosilicate glass and glass ceramic substrates.
Recent Studies on Coating of some Magnesium Alloys; Anodizing, Electroless Coating and Hot Press Cladding
Authors: El Mahallawy Nahed , Harhash Mohamed
Published: December 2012

In the present study, coating of some magnesium alloys including AZ31 and AZ91 were studied using different techniques namely anodizing, electroless and hot press cladding. AZ91 alloy was coated using anodizing process using three types of environmental friendly electrolytes; the first based on sodium silicate, the second based on sodium hydroxide-boric acid-borax and the third on sodium silicate-potassium hydroxide-sodium carbonate-sodium tetra borate. Characterization of the anodizing layer was achieved by determination of surface morphology, microstructure, phase analysis, coat thickness, adhesion and corrosion resistance. It was found that the anodic film thickness increases with increasing the current density, anodizing voltage and deposition time until the deposition stops due to the formation of a thick anodic film. The range of the anodic film thickness is 28 42 µm.Optimization of the anodizing conditions - current density and deposition time was determined for each electrolyte. A corrosion efficiency ranging from 94% to 97% was reached; the highest value corresponding to the third electrolyte. Another study is the electroless Ni plating technique with zinc pre-treatment applied on several magnesium alloys and the effect of pre-treatment and post heat treatment on the coat characteristics. The surface morphology, surface roughness, thickness of the layer, EDX analysis, adhesion, hardness and corrosion resistance are covered in this part. The electroless layer thickness is about 6 µm. The results showed good bond quality of the coat maintaining good corrosion behaviour of electroless Ni-P based on potentiodynamic polarization tests in chloride solution where it was improved after heat treatment process. On the other hand, AZ31 was covered by a commercial pure aluminum sheet by hot pressing. The influence of the applied pressure, holding time and temperature on the bond characteristics was studied. The experimental investigation has revealed a good bond quality due to the effective mutual diffusion of Mg and Al. The phase analysis resulted in the formation of two equilibrium phases namely; Mg17Al12and Mg2Al3. The corrosion resistance of AZ31 is enhanced as a results of this process by 98.6%. Further points will be covered.Keywords: Magnesium alloys; Coating; Anodizing; Electroless; Hot press cladding; environmental friendly electrolytes; corrosion
The Risk of Pattern Collapse for Structures in Future Logic Devices
Authors: Sankarapandian M. , Peethala B. , Canaperi D. , Peter Daniel , Engesser Philipp , Okorn-Schmidt Harald
Published: December 2012

Pattern collapse has long been known in photoresist patterning where the resist patterns merge or collapse during rinsing and drying steps [. The forces responsible for this collapse were identified as capillary forces during the drying process. Structures such as titanium nitride DRAM cylinders [ and silicon Flash shallow trench isolation (STI) lines have also been observed to be pattern collapse sensitive due to increase in aspect ratio of the features. Micro-electromechanical systems (MEMS) devices also show a similar phenomenon, but on a larger length scale, and is referred to as stiction [. For the technology nodes <14 nm, back-end-of-line (BEOL) low-k structures are also on the verge to show pattern collapse behavior. Whether a structure is sensitive to pattern collapse or not depends on several parameters, which will be analyzed in this paper.
Removing W Polymer Residue from BEOL Structures Using DSP+ (Dilute Sulfuric-Peroxide-HF) Mixture – A Case Study
Authors: Lee Hun Hee , Yun Min Sang , Lee Hyun Wook , Park Jin Goo
Published: December 2012

As the feature size of semiconductor device shrinks continuously, various high-K metals for 3-D structures have been applied to improve the device performance, such as high speed and low power consumption. Metal gate fabrication requires the removal of metal and polymer residues after etching process without causing any undesired etching and corrosion of metals. The conventional sulfuric-peroxide mixture (SPM) has many disadvantages like the corrosion of metals, environmental issues etc., DSP+(dilute sulfuric-peroxide-HF mixture) chemical is currently used for the removal of post etch residues on device surface, to replace the conventional SPM cleaning [. Due to the increased usage of metal gate in devices in recent times, the application of DSP+chemicals for cleaning processes also increases [.
Single Bubble Cleaning and Vortex Flow
Authors: Reuter F. , Mettin Robert , Lippert A. , Holsteyns F. , Okorn-Schmidt H.
Published: December 2012

Ultrasonic cleaning is a well proven technique in many industrial, laboratory and even household applications. It is known that cavitation bubbles can induce fast microscale flows and thus are responsible for cleaning and even corrosion [1,2]. Nevertheless there are numerous effects that can have a potential role in cleaning processes, as the behavior of an acoustic bubble is very complex: radial oscillations, surface oscillations, leading sometimes to the disintegration of a bubble, collapses, rebounds and subsequently shockwaves, liquid jets and vortex flows can be observed. But as bubbles in sound fields typically appear in a random fashion and in complicated interactions, it is very hard to identify the processes and their effects with respect to cleaning. To isolate the various ongoing processes and to study them in detail, single cavitation bubbles and their interaction with a surface are examined in this work. The single bubbles are of sizes around 500 μm in radius and are produced by a pulsed laser that is focused into water, which allows creating bubbles of a repeatable size at a defined position.
Megasonic Cleaning to Remove Nano-Dimensional Contaminants from Wafer Surfaces: An Analytical Study
Authors: Nagarajan R. , Jain S. , Prabhudesai M.A. , Khanolkar A. , Reddy M.P. , Kumar M.S. , Vetrimurugan R. , Sundin P. , Thottathil S. , Goodson M.J.
Published: December 2012

Megasonic cleaning traditionally refers to use of acoustic fields in the 800 kHz 1 MHz range to remove contaminants adhered to surfaces immersed in liquid media. However, even fields driven by frequencies in the > 400 kHz regime exhibit virtually all characteristics of conventional megasonics. These include: unidirectional pumped flow of liquid (acoustic streaming) normal to the transducer, at velocities that scale as square of frequency; and, a near-absence of cavitational phenomena associated with ultrasonic cleaning. For the latter reason, megasonic cleaning is preferred over ultrasonics when attempting to remove contaminants from delicate, fragile, erodible or feature-rich surfaces. Silicon wafer cleaning in semiconductor manufacturing, integrated circuit cleaning, and printed circuit board cleaning have utilized megasonics (with appropriate chemistry) for several decades. The megasonic frequency offers the additional benefit of a very thin boundary layer over the immersed surface, which effectively exposes even sub-micron and nanodimensional particles to the flow of the cleaning liquid.
Development of a Integrated Dry/Wet Hybrid Cleaning System
Authors: Lee Jong Seok , Choi Geun Min , Jung Ji Nok , Lee Dong Duk , Hur Gin Yung , Lee Jai Ho , Chi Che Hyuk , Gimm Dae Hee
Published: December 2012

With scaling of ULSI devices, the process temperatures are continuously lowered. The oxide films, which were deposited at low temperature, show fast etching rates during wet etching compared to high temperature films. Also, the etch rates differ largely from other film deposition conditions. In order to overcome these etch rate differences during surface preparation, dry cleaning processes had been introduced where the etch selectivity of the soft oxide films to the thermal oxide are very similar, regardless of the film deposition conditions and the deposition temperature.
Frictional Analysis of PVA Brush for Post CMP Cleaning: Effects of Rotation Speed, Compression Distance, and Fluid Viscosity
Authors: Fujiwara Takashi , Sanada Toshiyuki , Fukunaga Akira , Hiyama Hirokuni
Published: December 2012

Chemical mechanical polishing (CMP) is widely used in the surface planarization process of semiconductor fabrication. The planarization process produces a large amount of surface residue that must be removed before the next process is initiated. Typically, a combination of roll-and pen-type polyvinyl acetal (PVA) brushes is used for removing such contaminants. In the subsequent 450-mm wafer processing step, PVA brush cleaning is a viable candidate for post-CMP cleaning. However, given that the mechanisms of nanoscale particle cleaning are still under investigation [1-, the designs and operating conditions for brush cleaning are determined by trial and error. In this study, as a first step toward understanding the cleaning mechanisms, the tribological contact condition of the PVA roll brush (i.e., hydrodynamic, mixed, or boundary lubrication) is considered by measuring the frictional coefficients. In particular, the effects of rotation speed, compression distance, brush length, and fluid viscosity on the friction force are investigated.
A New Retention Method for Sub-10 nm Liquid Filtration Using Fluorescent CdSe QDs
Authors: Liu Su Wen , Zhang Hai Zheng
Published: December 2012

As advances are made in the lithographic patterning process and critical defect size continues to shrink, new filters are required to remove particles in the sub-10 nm size range. Membrane filtration separates unwanted particles from a fluid by retaining particles on the membrane surface and pores, in much the same manner as a sieve. One key parameter of membrane performance is pore size, usually expressed as pore diameter. However, for nanofiltration, especially for the membranes whose pore size measures under 30 nm, manufacturers may use different methods to rate the membranes pore. Considering the different chemical structures of membranes, the vast combination of materials, and the methods of manufacturing, it is highly unlikely that a universal method can be used for all combinations.
Evaluation of High-Speed Linear Air-Knife Based Wafer Dryer
Authors: Tamaddon Amir Hossein , Belmiloud Naser , Doumen Geert , Struyf Herbert , Mertens Paul W. , Heyns Marc M.
Published: December 2012

With the downscaling of devices, due to device geometry shrinkage, the total number of cleaning steps has increased dramatically. As a result, the number of drying cycles after cleaning has increased as well. As the device shrinks with the integration density increase, it is noteworthy that a perfect drying efficiency is mandatory to obtain a high performance device [. Basically, the mechanism of wafer drying in semiconductor industry can be explained as: first reducing the amount of liquid on the wafer surface by mechanical forces. There are some approaches for removing the liquid such as spinning, high pressure gas blowing by nozzle or air-jet, vertical withdrawal from the liquid bath, using surface gradient tension and so on [2]. Second: if the mechanical forces in the liquid removal part are not sufficient for drying and some droplets or a thin liquid layer remain on the wafer surface, complete drying will be achieved by evaporation of the remaining layer on the wafer. After this evaporation step, known as state transformation, the wafers will be completely dried. Evaporation of the remaining liquid layer is the main mechanism for generating drying defects (watermarks, residues, particles, and etc.)[3]. In this study, we propose a new methodology for semiconductor wafer drying based on a high-pressure gas flow. In comparison to conventional drying tools, the new drying set up combines high speed drying (wafer drying time down to 2 sec at 150mm.s-1) and a low number of added drying defects.
X-Ray Induced Depth Profiling of Ion Implantations into Various Semiconductor Materials
Authors: Hönicke Philipp , Müller Matthias , Beckhoff Burkhard
Published: December 2012

The continuing shrinking of the component dimensions in ULSI technology requires junction depths in the 20-nm regime and below to avoid leakage currents. These ultra shallow dopant distributions can be formed by ultra-low energy (ULE) ion implantation. However, accurate measurement techniques for ultra-shallow dopant profiles are required in order to characterize ULE implantation and the necessary rapid thermal annealing (RTA) processes.
Removal of UV Cured Resin Using Hybrid Cleaning Method
Authors: Kim Min Su , Kang Bong Kyun , Kim Jae Kwan , Lee Byung Kyu , Park Jin Goo
Published: December 2012

Ultraviolet based nanoimprint lithography (UV-NIL) technology is widely used in nanosized fine pattern transfer. NIL, which uses low pressure and low temperature, makes it possible to fabricate 3-dimensional pattern [. So, UV-NIL is one of the techniques with great potential as a new manufacturing process. But, UV-NIL process uses an expensive quartz substrate for transmission of UV light. Therefore, quartz substrate needs to be recycled to reduce the manufacturing cost. Usually, UV-NIL uses UV curable resins, whose chemical bonding and structure could be altered during UV light exposure which would result in crosslinking between the polymers. This UV cured resin with cross-linked structure is very hard to remove from the quartz substrate [. Conventionally, UV cured resin is removed by treating with sulfuric acid-hydrogen peroxide mixture (SPM) followed by ammonium hydroxide-hydrogen peroxide mixture (APM). One of the major drawbacks in using SPM-based treatment is the chemical haze formation and particle contamination on the quartz substrate [. Thus, an alternative cleaning composition will be of interest.
Surface Charge and Interface State Density on Silicon Substrates after Ozone Based Wet-Chemical Oxidation and Hydrogen-Termination
Authors: Angermann Heike , Wolke Klaus , Gottschalk Christiane , Moldovan Anamaria , Roczen Maurizio , Fittkau Jens , Zimmer Martin , Rentsch Jochen
Published: December 2012

For more than 20 years, the application of ozone dissolved in pure deionised water (DIW-O3) has been investigated for wafer-cleaning and resist stripping applications in the semiconductor industry [, , ]. To reduce chemical consumption and disposal costs as well as to improve cleaning efficiency, DIW-O3 is used in semiconductor wet cleaning processes as an alternative to traditional sulphuric acid peroxide (H2SO4/H2O2) [] and RCA [] cleans. Silicon solar cell fabrication includes multiple wet cleaning steps involving large amounts of chemicals. In Si substrate manufacturing the wet-chemical oxidation of substrate surface is used mainly for three purposes: (i) the removal of surface contamination and surface micro-roughness by different cleaning and smoothing procedures in H2O2 containing solutions (RCA I and RCA II) [5], in H2SO4/H2O2 [4], (ii) the preparation of hydrophilic surfaces for subsequent layer deposition [,] and (iii) the fabrication of thin oxide layers []. Chemical consumption could be reduced by replacing some of these chemicals with a mixture of pure deionised water with dissolved ozone for cleaning and surface conditioning. The kinetics of wet-chemical oxidation in DIW-O3 were recently investigated by ellipsometrical measurements of oxide thicknesses (ox>) [3,6,7], by SPV-measurements [7,], by contact angle measurements as well as by quasi-steady-state photo conductance (QSSPC) measurements [7].
Improved Surface Cleaning by In Situ Hydrogen Plasma for Amorphous/Crystalline Silicon Heterojunction Solar Cells
Authors: Granata Stefano Nicola , Bearda Twan , Dross Frederic , Gordon Ivan , Poortmans Jef , Mertens Robert P.
Published: December 2012

In future, thin wafers (< 100µm) will be employed in silicon heterojunction solar cell to decrease modules cost-per-Watt-Peak. However, in order to maintain excellent cell efficiency a higher device surface/volume ratio will demand stricter requirements on surface passivation. In this frame, the status of the crystalline surface (c-Si) prior to amorphous silicon (a-Si:H(i)) plasma deposition (PECVD) plays an important role: the c-Si chemical termination influences the quality of the interface layer a-Si:H(i)/c-Si, and affect the open circuit voltage (Voc). Previous studies have shown that smooth and fully hydrogenated c-Si surface [ lead to best quality heterojunction. These surfaces can be obtained by different wet cleaning procedures, usually terminated by an immersion in diluted HF. However, after this step, the wafer surface is highly reactive and can re-oxidize rapidly: contaminants presents in air can be adsorbed and affect wafer passivation [. For this reason, in-situ Hydrogen (H2) plasma cleaning prior to a-Si:H(i) deposition might be an interesting option to decrease the amount of contaminant on the surface. However, the experimental window is extremely narrow, since phenomena like epitaxial growth and ion-bombardment damage can easily occur [[ and worsen the surface passivation operated by a-Si:H(i) layers. In this contribution, we present an in-situ H2 plasma clean and show a decrease of Oxygen and Carbon on wafer surface after a short time (<10 sec), without detrimental effects on the subsequent passivation.
Chemical Control of Surfaces: From Fundamental Understanding to Practical Application
Authors: Hines Melissa A.
Published: December 2012

In the early days of the microelectronics industry, it became clear that even trace contaminants could have detrimental impact on the electronic properties of fabricated devices. This realization led to the development of the so-called RCA clean for silicon surfaces [], which uses sequential baths in basic and acidic hydrogen peroxide solutions, now known as SCA-1 and SCA-2, to oxidize organic materials, remove particulates, and bind metallic impurities. The detailed characterization of this process as well as its simplicity and economic viability soon led to its widespread industrial adoption. Although the RCA clean includes an optional etch in dilute HF between the two cleaning solutions to remove the native oxide layer, the overall process results in an extremely clean but electronically defectiveoxide-terminatedand thus extremely hydrophilic silicon surface, which we now know is quite rough on an atomic scale [].
Spatial Patterns of Malaria Reported Deaths in Yunnan Province, China
Authors: Bi Yan , Hu Wenbiao , Yang Henling , Zhou Xiao-Nong , Yu Weiwei , Guo Yuming , Tong Shilu
Published: December 2012

Malaria has been a heavy social and health burden in the remote and poor areas in southern China. Analyses of malaria epidemic patterns can uncover important features of malaria transmission. This study identified spatial clusters, seasonal patterns, and geographic variations of malaria deaths at a county level in Yunnan, China, during 1991–2010. A discrete Poisson model was used to identify purely spatial clusters of malaria deaths. Logistic regression analysis was performed to detect changes in geographic patterns. The results show that malaria mortality had declined in Yunnan over the study period and the most likely spatial clusters (relative risk [RR] = 23.03–32.06, P < 0.001) of malaria deaths were identified in western Yunnan along the China–Myanmar border. The highest risk of malaria deaths occurred in autumn (RR = 58.91, P < 0.001) and summer (RR = 31.91, P < 0.001). The results suggested that the geographic distribution of malaria deaths was significantly changed with longitude, which indicated there was decreased mortality of malaria in eastern areas over the last two decades, although there was no significant change in latitude during the same period. Public health interventions should target populations in western Yunnan along border areas, especially focusing on floating populations crossing international borders.
Review of Most Important Biomedical Databases for Searching of Biomedical Scientific Literature
Authors: Masic Izet , Ferhatovica Asima
Published: December 2012

We are living in the time of displossion of medical scientific information. Only in PubMed/MedLine, one of the largest host of scientific biomedical literature is indexed in almost 5,000 scientific biomedical journals. Each scientific paper is recorded in data written by rules recommended by several scientific associations and institutions. Databases can contain information about the author(s) and his/their published scientific works or results of research/investigation, including bibliographic data, abstract or full text of the paper. The databases are collecting and processing the best scientific and professional papers, or reviews and case reports published in scientific and professional journals or other publications. The reliability and quality of information guarantees producers of databases. Most important databases are located in famous university/academic centers like Bethesda [National Library Medicine (NLM)], Philadelphia (ISI), Amsterdam (Elsevier), Ipswitch (EBSCO), Geneva (WHO), Moscow (RAS), Shiraz [Islamic World Science Citation Center (ISC)], Warsaw [Index Copernicus (IC)]. Author of this review article shortly described most important online databases of biomedical literature today which will be usefull for scientists or other medical professionals.

How to cite this article

Masic I. Review of Most Important Biomedical Databases for Searching of Biomedical Scientific Literature. Donald School J Ultrasound Obstet Gynecol 2012;6(4):343-361.
Three-dimensional/Four-dimensional Sonography moved Prenatal Diagnosis of Fetal Anomalies from the Second to the First Trimester of Pregnancy
Authors: Pooh Ritsuko K
Published: December 2012

The introduction of three-dimensional (3D)/four-dimensional (4D) sonography with high-frequency transvaginal transducer has resulted in remarkable progress in ultrasonographic visualization of early embryos and fetuses and development of new fields of 3D sonoembryology. With the proper use of this new diagnostic modality and with experienced examiner, both structural and functional development in the first trimester of gestation can be assessed more objectively and reliable.

Indeed, new technology moved embryology from postmortem studies to the in vivo environment. Furthermore, there are good reasons to believe that 3D/4D sonography moved prenatal diagnosis of fetal abnormalities from the second to the first trimester of pregnancy. We will try to illustrate it with the number of convincing figures.

How to cite this article

Pooh RK, Kurjak A. Three-dimensional/ Four-dimensional Sonography moved Prenatal Diagnosis of Fetal Anomalies from the Second to the First Trimester of Pregnancy. Donald School J Ultrasound Obstet Gynecol 2012;6(4):376-390.
Pulse Oximetry and Breathing Training1
Authors: Gilbert Christopher
Published: December 2012

Small pulse oximeters have become widely available and can be useful for noninvasive monitoring of blood oxygen saturation by nonmedical personnel. When training control of breathing, an oximeter helps to reassure clients who hyperventilate that their oxygenation is adequate, offsetting their perception that they are not getting enough air. Low saturation may indicate a medical condition that impairs oxygen absorption. In that case, hyperventilation is a biological compensation that should not be tampered with.
Development and Regeneration in the Endocrine Pancreas
Authors: Mansouri Ahmed
Published: December 2012

The pancreas is composed of two compartments that deliver digestive enzymes and endocrine hormones to control the blood sugar level. The endocrine pancreas consists of functional units organized into cell clusters called islets of Langerhans where insulin-producing cells are found in the core and surrounded by glucagon-, somatostatin-, pancreatic polypeptide-, and ghrelin-producing cells. Diabetes is a devastating disease provoked by the depletion or malfunction of insulin-producing beta-cells in the endocrine pancreas. The side effects of diabetes are multiple, including cardiovascular, neuropathological, and kidney diseases. The analyses of transgenic and knockout mice gave major insights into the molecular mechanisms controlling endocrine pancreas genesis. Moreover, the study of animal models of pancreas injury revealed that the pancreas has the propensity to undergo regeneration and opened new avenues to develop novel therapeutic approaches for the treatment of diabetes. Thus, beside self-replication of preexisting insulin-producing cells, several potential cell sources in the adult pancreas were suggested to contribute to beta-cell regeneration, including acinar, intraislet, and duct epithelia. However, regeneration in the adult endocrine pancreas is still under controversial debate.
The Pak4 Protein Kinase in Breast Cancer
Authors: Minden Audrey
Published: December 2012

Paks4, along with Paks5, and 6 are members of the group B family of p21-activated kinases (Paks). The Paks play multiple different roles in controlling cell morphology, cell growth, proliferation, and signaling. Pak4 has essential roles in embryonic development (Qu et al., 2003), but in adults high levels of Pak4 are frequently associated with cancer. Pak4 has been implicated in several types of cancer (Wells and Jones, 2010; Eswaran et al., 2009; Liu et al., 2008; and Liu et al., 2010) and it is strongly linked to breast cancer (Liu et al., 2008; Liu et al. 2010; Yu et al., 2009; Rafn et al., 2012; and So et al., 2012). Breast tumors and breast cancer cell lines frequently have high levels of Pak4 (Liu et al., 2008), and overexpression of Pak4 in mammary epithelial cells leads to tumorigenesis in mice (Liu et al., 2010). This paper summarizes the current work on the role of Pak4 in breast cancer.
Comportamento do Consumidor Soteropolitano: Uma Abordagem Quantitativa para Análise dos Grupos de Referência e Atributos Decisivos na Compra de Refrigerantes
Authors: Marques Erica Ferreira , Neiva Tamara Moreira da Silva
Published: December 2012

Em levantamento realizado pelo IBGE (2010), a regio Nordeste configurou como o menor consumo per capita de refrigerante se comparado as demais regies do pas; e o estado da Bahia ficou em 6 lugar dentre os estados nordestinos. Assim, Salvador (BA) est no ranking das capitais que menos consome esse tipo de bebida. Segundo Souki; Christino e Pereira (2005), apesar da importncia econmica da indstria de refrigerantes no Brasil, a reviso da literatura mostra que so raras as incurses cientficas sobre o comportamento dos consumidores de tais produtos, fazendo com que tal tema ainda permanea pouco conhecido. A partir disso, o presente estudo desenvolveu-se com o objetivo de conhecer e caracterizar o comportamento de compra do consumidor soteropolitano de refrigerantes, identificando seus hbitos de consumo e decises que so tomadas no momento da compra do produto, os grupos de referncia, e os atributos considerados importantes para a sua deciso de compra. Para tanto, foi realizado um levantamento do tipo survey, de natureza descritiva, com variveis quantitativas, totalizando 429 entrevistas pessoais em diferentes bairros de Salvador, em locais com grande fluxo de pessoas, como instituies de ensino e espaos pblicos. Verificou-se que a maior parte dos entrevistados escolhe qual refrigerante comprar com base em suas experincias. No entanto, observou-se a influncia de alguns grupos de referncia no processo de compra do produto ao relacionar com algumas variveis de segmentao. Em relao aos atributos do refrigerante, constatou-se que o sabor, a marca e o preo so os atributos considerados mais decisivos pelos entrevistados em sua deciso de compra. DOI: 10.5585/remark.v11i3.2383
Design and Analysis of a Wall-Climbing Robot Based on a Mechanism Utilizing Hook-Like Claws
Authors: Xu Fengyu , Wang Xingsong , Jiang Guoping
Published: December 2012

Wall-climbing robots have extensive applications, however, no effective adhesion system has been designed for robots deployed in high-altitude, rough concrete buildings that are subjected to large wind loads and vibrations. This paper proposes a new suction method based on a mechanism utilizing hook-like claws and presents the design of a robot system for inspecting rough concrete walls. We present a method for describing the degree of concrete surface roughness. To study the stress imposed on the hook-like claws, we propose two types of mechanical models for the interactions between sharp claws and microprotuberances. The design method for the tips of the sharp claws is then established. Finally, an 8-foot wall-climbing robot based on a mechanism utilizing hook-like claws is designed and laboratory experiments on a man-made concrete wall are conducted. The results indicate that the low-cost system endows the robot with enhanced climbing stability and satisfies the inspection requirements for tower constructed by water brush stone or bricks.