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The existing chemical index of alteration has a difficulty to evaluate the degree of weathering in biotite granites due to an assumption that K2O content decreases along with Na2O, CaO, and MgO. We found that relative K2O content increases during weathering of biotite granite, as it is retained within such rocks due to (1) the chemical and physical stability of K-feldspar and (2) the formation of illite via incorporation of K ions released from biotite. The calculated ranges of most chemical indexes for biotite granite weathering do not show a good correlation with the weathering grade except the CIW, WIP and V indexes. The range of the CIW, WIP and V indexes according to the weathering grade were very small, and thus small errors in whole-rock chemical analyses can produce large discrepancies in calculated values. Further, the WPI index is a relative weathering index that depends on the composition of a fresh standard sample and cannot be applied to determine the absolute degree of weathering in granites if no protolith is available. We suggest a new weathering index (BWI; Biotite weathering index) based on a decrease in the number of K ions in the interlayer site of biotite during weathering of granite. Newly calculated values show a much wider range than the CIW, WIP and V indexes with a good relationship with a weathering grade. Therefore, it is necessary to establish the new index for a detailed classification of weathering degree.

The multicomponent olivine cathode material, LiMn1/3Fe1/3Co1/3PO4, was prepared via a novel coprecipitation method of the mixed transition metal oxalate, Mn1/3Fe1/3Co1/3(C2O4)·2H2O. The stoichiometric ratio and distribution of transition metals in the oxalate, therefore, in the olivine product, was affected sensitively by the environments in the coprecipitation process, while they are the important factors in determining the electrochemical property of electrode materials with multiple transition metals. The effect of the pH, atmosphere, temperature, and aging time was investigated thoroughly with respect to the atomic ratio of transition metals, phase purity, and morphology of the mixed transition metal oxalate. The electrochemical activity of each transition metal in the olivine synthesized through this method clearly was enhanced as indicated in the cyclic voltammetry (CV) and galvanostatic charge/discharge measurement. Three distinctive contributions from Mn, Fe, and Co redox couples were detected rev...

The alkyl derivatives of boehmite were prepared by solvothermal reaction of aluminum isopropoxide in n-alcohols (ethanol, 1-butanol, 1-hexanol, 1-octanol and 1-dodecanol) and the products were recovered as aerogel/xerogel by the removal of the solvent at the end of reaction. Aerogel or xerogel can be obtained simply by using only a reaction vessel (autoclave) and the obtained products were composed of plate-like particles having a well-developed boehmite structure. The alumina powders obtained by calcination of these products had relatively large pore-volumes ranging from 1.35 to 2.56 cm3/g. Transformation into α-Al2O3 was retarded even after calcination at 1200 °C. The effect of n-alcohols used in the solvothermal reaction on the phase, morphology and pore-texture of the alumina samples are discussed.

In order to investigate the effects of the crystallite size on the photoluminescence (PL) properties of a phosphor, monodisperse spherical SiO 2 /Y 2 O 3 :Eu 3+ phosphor core/shell particles were synthesized. On the surface of the core particles prepared by the Stober method, the phosphor shell was continuously coated by a heterogeneous precipitation method. Because the growth of the crystallite was restricted by the shell thickness, the crystallite size could be successfully controlled at the same firing conditions. The PL intensity, the asymmetric ratio and thus the color purity were significantly decreased with the decrease of the crystallite size. In addition, the position of charge transfer band in the PL excitation spectrum was red-shifted with the decrease of the crystallite size.

The reaction of alumina isopropoxide (AIP) in straight-chain primary alcohols at high temperatures yields the alkyl derivatives of boehmite. Crystallinity of the alkyl derivatives of boehmite can be controlled by the feed ratio of AIP/alcohol. The alumina samples derived from the products having poor crystallinity had large pore-volumes (1.16–3.24 cm3/g).

In attempts to improve the performance of dissimilar joints between AZ31 Mg alloy and different Al alloys, solid state joining processes such as Magnetic Pulse Welding (MPW) and Friction Stir Welding (FSW) were applied for minimizing the formation of brittle intermetallic phases. MPW process has been concentrated mainly on round section tube to tube and tube to bar welds. Mg alloy AZ31 has been successfully welded to pure Al A1070 as well as to Al alloy A3003. Tensile test clearly showed the MPW welds were stronger than the weaker of the base metal so failure occurred in aluminum base metal. While FSW process for the dissimilar joint between AZ31B/A6061 alloys with a thickness of 2mm revealed optimum weldability under the conditions of travel speed of 0.8mm/sec and tool rotation speed of 850rpm. For the sound dissimilar joint, the maximum tensile strength of 179 MPa, which was about 80 % of the Mg base metal tensile strength, has been obtained.

This paper dealt with the acoustic detection of partial discharge(PD) in insulation oil for insulation diagnostics of oil immersed transformers. Electrode systems such as needle to plane, plane to plane, and floating were fabricated to simulate some defects in transformers. A wide band acoustic emission(AE) sensor with the frequency ranges of 100 kHz～1 MHz and a narrow band AE sensor with the resonant frequency of 140 kHz were used in the experiment. Also, a decoupler and an amplifier were designed to detect and amplify the acoustic signal only. The decoupler separates acoustic signal from DC source without any distortion, and the amplifier has the gain of 40 dB in frequency ranges of 11 kHz～4 MHz. In the experiment, frequency components and propagation characteristics of acoustic signal were analyzed, and an algorithm of positioning of PD occurrence by the time difference of arrival was proposed. From the results, the frequency components of the acoustic signal exist from 50 kHz to 200 kHz and the positioning error of PD calculated by three AE sensors was within 1%.Key Words : Acoustic detection, Partial discharge(PD), Oil immersed transf ormer, Insulation diagnostic, Frequency component, Positioning, Propagation

The in-depth study of the multicomponent effect on the structural and electrochemical properties of olivine cathodes is conducted using state-of-the-art first-principles calculations. The distribution of multiple transition metals in olivine structure alters local crystal structure and electronic structure, affecting its kinetic and thermodynamic properties. We find that local structure change, such as the reduced Jahn−Teller effect of Mn, significantly enhances both Li mobility and electron (polaron) conductivity when the redox Mn element neighbors Fe or Co. The unexpected one-phase Li insertion/extraction reaction of the multicomponent olivine cathode is explained with respect to the multiple interactions of M/Li or M/vacancy (M = transition metals). The redox potential of each transition metal also could shift as a result of charge redistribution and the relative energy change from the multiple M/Li interactions. Implications of multicomponent olivine as a useful strategy for tailoring the electrochemi...

This article examines the relation between the privatization of state-owned enterprises and the changes in their financial and operating performance through the case study of Korea Telecom (KT), which is the biggest telecommunications (telecom) company in Korea. The Korean government completed the privatization of KT in May 2002, arguing that it would help KT to improve its financial and operating performance, as well as contribute to the development of the telecom industry. This article presents the changes in KT's revenues, assets, net income margins, return on assets, real sales per employee, investments, and dividends to evaluate its financial and operating performance, as well as the impact of the privatization of KT on the Korean telecom industry over the pre- and post-privatization windows. ACCESS TO FULL TEXT

The electrochemical properties and phase stability of the multi-component olivine compound LiMn1/3Fe1/3Co1/3PO4 are studied experimentally and with first-principles calculation. The formation of a solid solution between LiMnPO4, LiFePO4, and LiCoPO4 at this composition is confirmed by XRD patterns and the calculated energy. The experimental and first-principle results indicate that there are three distinct regions in the electrochemical profile at quasi-open-circuit potentials of ∼3.5 V, ∼4.1 V, and ∼4.7 V, which are attributed to Fe3+/Fe2+, Mn3+/Mn2+, and Co3+/Co2+ redox couples, respectively. However, exceptionally large polarization is observed only for the region near 4.1 V of Mn3+/Mn2+ redox couples, implying an intrinsic charge transfer problem. An ex situ XRD study reveals that the reversible one-phase reaction of Li extraction/insertion mechanism prevails, unexpectedly, for all lithium compositions of LixMn1/3Fe1/3Co1/3PO4 (0 ≤ x ≤ 1) at room temperature. This is the first demonstration that the well-ordered, non-nanocrystalline (less than 1% Li–M disorder and a few hundred nanometer size particle) olivine electrode can be operated solely in a one-phase mode.

A solid solution of spinel (2/3)Li(Li1/3Ti5/3)O4–(1/3)Li(Ni1/2Ti3/2)O4 was prepared, and its structural/electrochemical properties were compared with Li(Li1/3Ti5/3)O4 to identify the effect of doping to the structural invariance of Li(Li1/3Ti5/3)O4. The solid solution retained the zero strain characteristic of Li(Li1/3Ti5/3)O4 during discharge/charge with an excellent cycle stability, while the rate capability was notably improved. However, a reversible broadening of the XRD peak was observed at the end of discharge, indicating some structural changes. XANES measurements showed that the oxidation state of Ti was +4 and that of Ni was +2 in the solid solution.

The alkyl derivatives of boehmite (alkoxyalumoxanes; AlO(OH)1−x (OR) x ) were synthesized by the reaction of aluminum triisopropoxide in straight-chain primary alcohols at 300 °C for 2 h in an autoclave. In the present work, pore structures of aluminas obtained by calcination of the alkyl derivatives of boehmite were examined. The alumina obtained from the ethyl derivative of boehmite had a broad pore-size distribution, while the pore-size of the alumina obtained from the dodecyl derivative of boehmite distributed in a narrow range in the mesopore region. The mode pore diameter of the latter alumina increased with the increase in calcination temperature (as-syn., 39 A; 600 °C, 54 A; 800 °C, 58 A; 1000 °C, 68 A), but narrow pore-size distribution was maintained even after calcination at high temperatures.

This paper dealt with the disinfection performance by Ultra-Violet Light Emitting Diode (UV LED) for a phytoplankton as a basic study for the development of a low-energy consumption ballast water treatment system. UV LEDs having peak wavelength of 255nm, 265nm and 280nm were used in the experiment. UV LED modules with driving circuit were fabricated, and optical and electrical characteristics of them were analyzed. The disinfection performance for phytoplankton depending on the UV wavelength was evaluated by comparing the number of phytoplankton before and after the UV treatments. The experimental result showed that the highest disinfection wavelength for the phytoplankton was 265nm.

Yb2+ ion doped Ba5(PO4)3Cl phosphor was synthesized by solid state reaction. Four distinct absorption bands were observed in the Ultraviolet (UV) light region due to the electronic transitions of Yb2+ ion from 1S0 ground state to 2F5/2(t2g), 2F5/2(eg), 2F7/2(t2g), and 2F7/2(eg) excited states. The main emission wavelength of the phosphor was around 630 nm. The optimized Yb2+ ion concentration was 0.2 mol% (λexc. = 400 nm). The calculated critical distance was about 8.729 A and the concentration quenching was observed above 0.2 mol% due to the electric dipole–dipole interaction.

In this paper, the safety for passengers of composite car-body against lightning strikes was analyzed by the application of an impulse generator which can produce impulse current up to 50 kA with 8/ waveform. Potential difference on inside surface of the car-body was measured as a safety parameter for the passengers against lightning strikes. The potential difference between 20 em distant was 175 V at 37.67 kA, and it corresponds to 875 V between 1 m distant. The amount of charge flowing a passenger at 100 kA impulse current can be estimated to . This is much less than the limit amount of charge for human body, which is presented by Koeppen and Osypka.

In this study, the characteristics of granular activated carbon (GAC) supported metal was investigated in an area influenced by flame discharge and temperature variation during irradiating microwave. The modified GAC was formulated by impregnating metal hydroxides of nickel (Ni/GAC), barium (Ba/GAC), copper (Cu/GAC), zinc (Zn/GAC), cobalt (Co/GAC) and lanthanum (La/GAC). Ba/GAC was selected as it showed lack of spark discharge and temperature increasing aspects. Comparison of adsorption and desorption amount of GAC and Ba/GAC showed that adsorption and desorption rate of the GAC were higher than those of Ba/GAC. The results show that the presence of barium can decrease adsorption/desorption rate because of plugging pore of GAC. Toluene regeneration rate of Ba/GAC was better than that of GAC due to barium loading. Finally, GAC with barium can be controled a rapid increasing temperature and spark discharge, increased the regeneration rate of toluene during desorption by irradiating microwave.

The concept of a spectacle as an element of urban landscape is demonstrated by the relationship between the idea of sensible urban experiences and the surface of architecture. The face of architecture can go beyond visual experiences and create surfaces that communicate images by expressing a spectacle. In other words, the installations and surface finishes of architecture make it possible for us to use architecture as a tool for experiential marketing. This study was conducted in order to understand the spectacle phenomenologically as a means of expression in urban consumer space that constantly changes according to the development of the media in urban consumer spaces, and according to the changes of visual perception. In addition, the spectacle is seen as a surface element of architecture that creates urban landscapes. The purpose of this study is to examine how rhetorical expressions of spectacles are used as strategic tools to merchandize architecture as a component of urban landscapes. In conclusion, the authors discuss what roles spectacles play in consumer spaces in order to determine the representative characteristics of surfaces in an attempt to understand architectural surfaces of contemporary urban landscapes as a phenomenon of perceptive communication.

The influence of steel fiber volume on the tension softening behavior in steel fiber-reinforced ultra high strength concrete was investigated. Three-point bending test (TPBT) with notched beams was performed and inverse analysis method by Uchida et al. was adopted to obtain the tension softening behaviors from the results of TPBT. It could be found that the intial stiffness was constant regardless of steel fiber volume, the increase of steel fiber volume fraction made the tensile strength higher, but all of the curves converged on an asymptote with a crack width. It was proposed the equation of softening curve expressed by combination of plastic behavior part and exponential descending behavior part considering the steel fiber volume fraction and w0, which is corresponding to the maximum crack width of plastic area. Thereafter, the crack propagation analysis using finite element method with smeared crack model was also carried out and it was confirmed that the proposed equation had a good agreement with the experimental results.

Solvothermal oxidation of gallium metal in various organic solvents at 300 °C under the autogenous vapor pressure of the solvents was examined. The reaction of gallium metal in 1-butanol or 2-methoxy-ethanol at 300 °C did not proceed and unreacted gallium metal was recovered even with prolonged reaction time. On the other hand, gallium metal reacted in aminoalcohols such as 2-aminoethanol, 2-methylaminoethanol, 2,2′-iminodiethanol and 2,2′,2″-nitrilotriethanol yielding γ-Ga 2 O 3 . The product obtained by this reaction has a relatively large crystallite size as compared with γ-Ga 2 O 3 prepared by the conventional method.

Although Magnetic Pulse Welding(MPW) is not a recently developed technique, it has gained the attention of the automotive industry. MPW has become an accepted welding process because it enables the joining of similar, and dissimilar materials, with a very short cycle time, without the need for filler metal and gases. In this study, the effect of the stand-off distance on the weld strength has been investigated. The compressive strength of the MPW joints was evaluated using UTM. The interface of weld, IMC composition and morpology were studied by SEM and EDS. It was concluded that the stand-off distance and the voltage are the main parameters influencing the strength of weld. In case of too high stand-off distance, it influenced harmful effect because of the resistance of deformation.

The object of this paper is to acquire the data related to insulation evaluation of hybrid vehicle traction motors. We made a comparative analysis on Insulation Resistance (IR), Dielectric Absorption Ratio (DAR), and Polarization Index (PI) of the motor stators. The experiment was carried out according to IEEE Std. 43 and IEC 60085-1 for insulation resistance test standard of rotating machinery. Test voltage of 500 V was applied between a phase and the enclosure. The IR and the DAR of used motors were lower than those of new ones. The DAR and the PI were and , respectively and the result did not meet the recommendation basis 2 for insulation level H. From the experimental results, we could prepare parameters and basis for insulation evaluation of the traction motor stator by the comparative analysis of short-time insulation resistance changes, DAR and PI.

Resor House can be considered significant since it provides a meaningful clue to understanding the changes in Mies′ conception of architectural space, particularly the relationship between the inte...

Individual vehicle information, especially, vehicle classification data play a key role in Advanced Traffic Management and Information Systems (ATMIS). In inductive loop and piezo-sensor fusion systems, traffic data such as the vehicle length and the distance between axles are used for vehicle classification. However, classification errors often occur in distinguishing passenger cars from small trucks and in distinguishing medium-sized trucks from small trucks. It is mainly attributed to the fact that they are similar in lengths and have similar inter-axle distances. To improve the performance in vehicle classification, we develop a new algorithm using a fuzzy logic. Vehicle weight and speed are used as the inputs to the fuzzy logic block. The output of the fuzzy logic block is a weighting factor to modify the calculated vehicle length. Experimental results show that the developed algorithm significantly improves the classification performance.

In past decades, the themal inkjet (TIJ) printer has been widely used as one of the most well-known digital printing technology due to its low cost, and high printing quality. Since the printing speed of TIJ printers are much slower than that of laser printers, however, there has been intensive efforts to raise the printing speed of TIJ printers. One of the most plausible methods to raise the printing speed of TIJ printers is to adopt a page-wide array TIJ printhead. To accomplish this goal, the high efficiency inkjet heating resistor should be developed to settle the high power consumption problem of a page-wide array TIJ printhead. Recently, it was reported that atomic layer deposited RuO2-TiO2 heating resistor has many attractive properties for using it as a heating resistor such as appropriate resistivity range with a sufficiently low temperature coefficient of resistance (TCR) values and high oxidation resistance even at high temperatures. In this study, we investigated IrO2-TiO2 thin film resistor prepared by atomic layer deposition method. Similar to RuO2, IrO2 also have low resistivity and good oxygen diffusion barrier properties. Compare to Ru, the volatile phases of Ir form at above 1000°C, and no phase transformations are known in the temperature range from 4.2 to 1000K, which means that IrO2 remain more stable than RuO2 at higher annealing temperatures. The six samples were prepared and labeled as A: (IrO2)0.33-(TiO2)0.67, B: (IrO2)0.56-(TiO2)0.44, C: (IrO2)0.64(TiO2)0.36, D: (IrO2)0.72-(TiO2)0.28, and E: (IrO2)0.78(TiO2)0.22, respectively. These samples were prepared by adopting an adequate super-cycle for IrO2-TiO2 ALD, which is composed of IrO2 and TiO2 subcycle. Figure 1 shows the resistivities of the IrO2-TiO2 thin films with respect to the IrO2 intermixing ratio. At IrO2 intermixing ratios less than 0.5, the film resistivity was increased drastically with decreases in the IrO2 intermixing ratio. At IrO2-TiO2 thin films with IrO2 intermixing ratios over 0.5, however, film resistivity did not undergo a steeper rate of change with increasing IrO2 intermixing ratio. For IrO2 intermixing ratios in the range 0.55 0.78, the resistivity of the films can be controlled from 1500 to 356.7 ·cm, corresponding to appropriate resistivities for heating resistor application. The behavior of film resistivities is very similar to that of RuO2-TiO2, in which the resistivities are initially very high due to the high contents of highly resistive TiO2 and decrease gradually as the intermixing ratio of conductive oxide, RuO2 increases. With appropriate intermixing ratios (Sample C and E), the IrO2-TiO2 thin films showed lower absolute values of TCR values than TaN0.8336.1ppm/K). Compared to other systems, IrO2-TiO2 system has very small solubility above 600°C . Since their resistivities can be changed by solid solutions, therefore, the effect of O2 annealing on the resistivities of IrO2-TiO2 films were investigated, as shown in Figure 2. Though some solubility of TiO2 in IrO2 exist, the change in resistivities of IrO2-TiO2 films was below 10%. Therefore, it can be concluded that IrO2-TiO2 films can be also used as a heating resistor material.

This paper estimated the influence of volume of steel fiber on the tensile softening behavior in Ultra High Performance Concrete. Tensile softening curves were obtained from Three-Point Bending Test(TPBT) with notched beam. Inverse analysis method by Uchida et al. was introduced to obtain the tensile softening behaviors from the results of TPBT. We could find out that the increase of volume fraction of steel fiber makes the tensile strength higher but all of the curves converged on an asymptote with crack width. We proposed the equation of softening curve expressed by combination of plastic area and exponential descending area considering the volume fraction of steel fiber and ω0, which is corresponding to the maximum crack width of plastic area. We also carried out the crack propagation analysis using finite element method with smeared crack model and confirmed that the proposed equation had a good agreement with the experimental results.

Silica fume constitutes an element of extreme importance in improving the strength and fluidity of UHPC. The adopted amount of silica fume generally is generally exceeding 25% of cement in weight but the influence of this amount on the properties of UHPC is still remaining as a domain to be investigated. Accordingly, this paper investigates the effects of the amount of silica fume on the mechanical characteristics of the fluidity, compressive strength, elastic modulus and flexural strength and on the micro structure of UHPC by means of SEM and MIP. Results revealed that adequate amount of silica fume is improving the fluidity and strength. MIP tests demonstrated that such improvement is brought by the increase of hydrates due to the pozzolan reaction and the effective densification inside concrete due to the filler. It seemed also that similar mechanical characteristics can be obtained for a volumetric ratio to cement ranging between 10 and 25%.

The fibers alignment in steel fiber reinforced high strength concrete (SFR-HSC) has naturally significant influence on the mechanical properties of concrete. Fiber-reinforced concrete being manufactured by means various kinds of specimen shape and diversified filling methods and directions, these variables are likely to produce effect on the fibers alignment leading to large differences in its mechanical properties. This study intended to evaluate the effect of placing and flow direction not only on the fibers alignment but also on the tensile behavior of SFR-HSC. Section analysis using photographic shooting was adopted to investigate the fiber alignment and revealed considerable difference in the fiber alignment according to the placing and flow direction. The best alignment appears to be achieved when placing is done in the direction of the flexural tensile stress and the alignment was change with the flow distance although the same flow direction. Such placing and flow direction produce little difference in the first cracking strength but significant discrepancy up to 50% in the ultimate tensile strength.

The solvothermal reaction of aluminum isopropoxide in 1-decanol yielded the decyl derivative of boehmite [AlO(OH) (1− X ) (OC 10 H 21 ) X ]. This product belongs to a class of intercalation compounds where the guest moieties are covalently bonded to the host inorganic (boehmite) layers. In this work, the alkyl chains in the boehmite layers were partially removed by heat treatment in an He flow. X-ray diffraction (XRD), thermogravimeter (TG), and N 2 adsorption measurement showed that the voids surrounded by the alkyl chains were generated by the heat treatment. When the decyl derivative of boehmite was heated at 310 °C for 3 h in the He flow, the voids had the largest volume, but prolonged heat treatment resulted in partial collapse of the boehmite layers causing a smaller void volume.

Purpose: It is known that cyclooxygenase (COX)-2 expression is increased in Barrett’s esophagus and esophageal adenocarcinomas. We studied COX-2 expression and the effect sulindac has on the genesis of Barrett’s esophagus and adenocarcinoma in rats undergoing esophagogastroduodenal anastomosis (EGDA). Materials and Methods: Fifty-one rats were divided into a control group (n = 27), a 500 ppm sulindac-treated group (n = 15) and 1000 ppm sulindac-treated group (n = 9). Randomly selected rats were killed by diethyl ether inhalation at 20 and 40 weeks after surgery. Results: At 40 weeks, rats treated with 1000 ppm sulindac showed narrower esophageal diameter and milder inflammation than the control rats. At 40 weeks, the incidence of Barrett’s esophagus was similar between control and sulindac-treated groups, but the incidence of adenocarcinoma was significantly lower in the 1000 ppm sulindac-treated group than either the control or 500 ppm sulindac-treated groups. COX-2 was significantly increased in the lower esophagus of control rats killed at 40 weeks. Cyclin D1 expression was negligible in the sulindactreated group compared with the control group. Conclusion: We suggest that the chemopreventive effect of sulindac is related to decreased COX-2 and cyclin D1 expression, which may be influenced by reduced inflammation.

An R-curve formula for ultra high performance cementitious composites is derived in this paper. The fracture mechanics based on R-curve is used to predict the load-deflection relation of ultra high performance cementitious composites. The reductions of stress intensity factor and CTOD by steel fiber reinforcement are assumed as conforming linear distribution along crack propagation. The effective numbers of steel fiber on unit area based uniform distribution is used here. Results of the theoretical predictions show a good agreement with test results of three point bending beam of UHPCC. The modified R-curve formula for UHPCC can be a reference for future study of fracture performances of UHPCC.

Direct uniaxial tension test of ultra high performance cementitious composites I shape specimens have been investigated in this paper. A nonlinear analytical model based on continuum damage mechanics is developed to characterize tensile stress-strain constitutive response of UHPCC. Basic governing equations of damage evolution and material constitutive relation are established considering random damage which conforms to a modified Weibull type distribution proposed in this paper. Calculation suggests that Weibull distribution can describe damage evolution of UHPCC and predict the constitutive relation and damage evolution equation.

Wide-ranging costs of laparoscopic surgery (LAP) are associated with variations in the experience levels of surgeons. There is no available report on the changes of economic outcomes relative to the LAP learning curve in the treatment of colorectal cancer. In the present study, we have compared changes in economic outcomes according to the LAP learning curve with the economic outcomes of open surgery (OS) for rectosigmoid cancer. A total of 197 patients with rectosigmoid cancer were included in this analysis; 116 received LAP and 81 received OS. Scatter of operative times demonstrated an early learning period of 37 cases in LAP. The following outcomes were compared between LAP and OS during the early learning period and experienced periods; operating room (OR) costs, OR-related hospital profit, total hospital charge, and patient payment. During the median interval of two periods according to the laparoscopic surgery learning curve, there was an inflation rate of about 10% on the medical charges such as operation, radiology, laboratory, and admission fee. Operating room costs were significantly higher after LAP during the two periods, but the median difference between LAP and OS decreased during the experienced period ($3,055 to $1,850). With increasing operative experience in LAP, the OR-related hospital deficit improved (−$1,072 to−$840). Total hospital charges were significantly higher for LAP than for OS in the early learning period (p 0.05). During the experienced period, patients paid a lower surcharge for LAP ($1,885–$1,118). Total hospital charges for laparoscopic surgery were substantially higher than those of open surgery during the early learning period, but become similar during the experienced period. The shortening of the learning period is a critical factor for achieving cost-effective laparoscopic surgery.

New multimedia services over the cellular/WLAN overlay networks require different Quality of Service (QoS). Therefore, efficient network management system is necessary in order to provide QoS sensitive multimedia services while enhancing network performance. In this paper, we propose a new online network management scheme that implements bandwidth reservation, congestion and transmission control strategies. Our online approach to network management exhibits dynamic adaptability, flexibility, and responsiveness to the current traffic conditions in multimedia overlay networks. Simulation results indicate the superior performance of our proposed scheme to strike the appropriate performance balance between contradictory QoS requirements under widely varying diverse traffic loads.

To compare the economic outcomes of laparoscopic surgery (LAP) with those of open surgery (OS) for colorectal cancer.We compared operating room (OR) costs, OR hospital-profits, total hospital charges, and payments made for 67 consecutive patients who underwent either OS (n = 41) or LAP (n = 26) for colorectal cancer.The operating time was longer in the LAP group (P0.001), but the hospital stay was shorter (P0.001). OR costs were higher in the LAP group, which was primarily attributed to the higher costs of consumables (LAP 1441, OS 575 dollars; P0.001) and the longer operating time (LAP 215 min, OS 155 min; P0.001). Total hospital charges were also higher after LAP (LAP 5017 dollars, OS 4093 dollars; P0.001). Patients paid more after LAP (P0.001), but there was no significant difference between the two groups in National Health Insurance Corporation payments.Laparoscopic surgery is less cost-effective than OS for colorectal cancer. The higher costs of consumables and the longer operating time associated with LAP must be addressed to make LAP more cost-effective.

Imidazolium ionic side-group-containing fluorene-based conjugated polyelectrolytes (CPEs) with different π-conjugated structures, poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (F8im-Br) and poly[(9,9-bis(8'-(3″-methyl-1″-imidazolium)octyl)-2,7-fluorene)-alt-(benzo(2,1,3)thiadiazol-4,8-diyl) dibromide (F8imBT-Br), are synthesized and utilized as an electron injection layer (EIL) in green-emitting F8BT polymer light-emitting diodes (PLEDs). Both CPE EIL devices significantly outperform Ca cathode devices; 17.9 cd A(-1) (at 3.8 V) and 16.6 lm W(-1) (at 3.0 V) for F8imBT-Br devices, 11.1 cd A(-1) (at 4.2 V) and 9.1 lm W(-1) (at 3.4 V) for F8im-Br devices, and 7.2 cd A(-1) (at 3.6 V) and 7.0 lm W(-1) (at 3.0 V) for Ca devices. Importantly, unlike the F8im-Br EIL devices, F8imBT-Br PLEDs exhibit much faster electroluminescence turn-on times (

The two-dimensional (2D) growth of cubic-structured (silicon) Si nanosheets (SiNSs) was investigated. Freestanding, single-crystalline SiNSs with a thickness of 5–20 nm were grown on various Si substrates under an atmospheric chemical vapor deposition process. Systematic investigation indicated that a diffusion-limited aggregation (DLA) environment that leads to dendritic growth in directions at the initial stage is essential for 2D growth. The kinetic aspects under DLA environments that ascribe to the dendritic and 2D growth were discussed. Under the more dilute conditions made by addition of Ar to the flow of H2, the SiNSs grew epitaxially on the substrates with periodic arrangement at a specific angle depending on the orientation of the substrate. It reveals that SiNSs always grew two dimensionally with exposing (111) surfaces. That is thermodynamically favorable. Electronic supplementary material The online version of this article (doi:10.1186/s11671-015-1138-2) contains supplementary material, which is available to authorized users.

Mixed-anion oxyfluorides (i.e., FeOxF2-x) are an appealing alternative to pure fluorides as high-capacity cathodes in lithium batteries, with enhanced cyclability via oxygen substitution. However, it is still unclear how the mixed anions impact the local phase transformation and structural stability of oxyfluorides during cycling due to the complexity of electrochemical reactions, involving both lithium intercalation and conversion. Herein, we investigated the local chemical and structural ordering in FeO0.7F1.3 at length scales spanning from single particles to the bulk electrode, via a combination of electron spectrum-imaging, magnetization, electrochemistry, and synchrotron X-ray measurements. The FeO0.7F1.3 nanoparticles retain a FeF2-like rutile structure but chemically heterogeneous, with an F-rich core covered by thin O-rich shell. Upon lithiation the O-rich rutile phase is transformed into Li-Fe-O(-F) rocksalt that has high lattice coherency with converted metallic Fe, a feature that may facilitate the local electronic and ionic transport. The O-rich rocksalt is highly stable over lithiation/delithiation and thus advantageous to maintain the integrity of the particle, and due to its predominant distribution on the surface, it is expected to prevent the catalytic interaction of Fe with electrolyte. Our findings of the structural origin of cycling stability in oxyfluorides may provide insights into developing viable high-energy electrodes for lithium batteries.

Graphene has been studied for various applications due to its excellent properties. Graphene film fabrication from solutions of graphene oxide (GO) have attracted considerable attention because these procedures are suitable for mass production. GO, however, is an insulator and therefore a reduction process is required to make the GO film conductive. These reduction procedures require chemical reducing agents or high temperature annealing. Herein, we report a novel direct and simple reduction procedure of GO by silicon, which is the most widely used material in the electronics industry. In this study, we also used silicon nanosheets (SiNSs) as reducing agents for GO. The reducing effect of silicon was confirmed by various characterization methods. Furthermore, the silicon wafer was also used as a reducing template to create a reduced GO (rGO) film on a silicon substrate. By this process, a pure rGO film can be formed without the impurities that normally come from chemical reducing agents. This is an easy and environmentally friendly method to prepare large scale graphene films on Si substrates.

BackgroundYoung people living with long term conditions are vulnerable to health service disengagement. This endangers their long term health. Studies report requests for digital forms of communication – email, text, social media – with their health care team. Digital clinical communication is troublesome for the UK NHS.AimIn this article we aim to present the research protocol for evaluating the impacts and outcomes of digital clinical communications for young people living with long term conditions and provide critical analysis of their use, monitoring and evaluation by NHS providers (LYNC study: Long term conditions, Young people, Networked Communications).MethodsThe research involves: (a) patient and public involvement activities with 16–24 year olds with and without long term health conditions; (b) six literature reviews; (c) case studies – the main empirical part of the study – and (d) synthesis and a consensus meeting. Case studies use a mixed methods design. Interviews and non-participant observation of practitioners and patients communicating in up to 20 specialist clinical settings will be combined with data, aggregated at the case level (non-identifiable patient data) on a range of clinical outcomes meaningful within the case and across cases. We will describe the use of digital clinical communication from the perspective of patients, clinical staff, support staff and managers, interviewing up to 15 young people and 15 staff per case study. Outcome data includes emergency admissions, A&E attendance and DNA (did not attend) rates. Case studies will be analysed to understand impacts of digital clinical communication on patient health outcomes, health care costs and consumption, ethics and patient safety.

A precise readout circuit with novel zero-g offset calibration for a high-end MEMS accelerometer is proposed. On-chip coarse and fine trimming in the readout circuit can reduce the wide range of zero-g offset to a few mg of a high-end MEMS accelerometer's zero-g offset accuracy. The readout circuit is fabricated in a 0.18um 1P4M CMOS process and consumes 900μW from a single 3.3-V supply.

This paper presents a study to analyze and modify the Islamic star pattern using digital algorithm, introducing a method to efficiently modify and control classical geometric patterns through experiments and applications of computer algorithms. This will help to overcome the gap between the closeness of classical geometric patterns and the influx of design by digital technology and to lay out a foundation for efficiency and flexibility in developing future designs and material fabrication by promoting better understanding of the various methods for controlling geometric patterns.

This paper concerns the theoretical research of shear failure load of steel fiber reinforced ultra high performance cement composites (SFR-UHPCC) beam. Based on test investigation, an analytical model of prestressed SFR-UHPCC beam is constituted. Two formulae of ultimate failure load, i.e. the upper bound and the lower bound of shear loading capacity, all have been obtained according to the limit analysis of concrete plasticity. In the process of upper bound analysis, uniform distribution of steel fiber has been assumed, and virtual work induced by steel fiber has been divided into two parts, i.e. pulling-out virtual work and debonding virtual work. Five coefficients are introduced considering some defects. Twelve SFR-UHPCC beams with three kinds of shear span ratio i.e. 2.7, 5.6 and 8.5 are tested and compared with the results from the proposed equations.

We reported aqueous solutions of poly(caprolactone-b-ethylene glycol-b-caprolactone) (PCL−PEG−PCL) that underwent sol−gel−sol transition as the temperature increased (Macromolecules 2005, 38, 5260−5265). However, when the triblock copolymer aqueous solution (20 wt %), initially as a sol phase, was left at room temperature (20 °C), it turned into an opaque gel in 1 h. The crystallization of the PCL−PEG−PCL triblock copolymer in water was suggested to be responsible for such a kinetic aspect of the phase transition. In addition, PEG/PCL multiblock copolymers were synthesized by coupling the triblock copolymers using terephthaloyl chloride. Even though both PCL−PEG−PCL triblock and PEG/PCL multiblock copolymer aqueous solutions (20 wt %) instantaneously undergo a sol-to-gel transition upon injection into 37 °C water and their thermogels show a maximum modulus at around body temperature (35−42 °C), the multiblock copolymer shows a pronounced sol phase stability at room temperature. The fundamental difference ...

A microaccelerometer with highly reliable, wafer-level packaged MEMS sensing element and fully differential, continuous time, low noise, BiCMOS interface circuit is fabricated. The MEMS sensing element is fabricated on a (111)-oriented SOI wafer by using the SBM (Sacrificial/Bulk Micromachining) process. To protect the silicon structure of the sensing element and enhance the reliability, a wafer level hermetic packaging process is performed by using a silicon-glass anodic bonding process. The interface circuit is fabricated using 0.8 µm BiCMOS process. The capacitance change of the MEMS sensing element is amplified by the continuous-time, fully-differential transconductance input amplifier. A chopper-stabilization architecture is adopted to reduce low-frequency noise including 1/f noise. The fabricated microaccelerometer has the total noise equivalent acceleration of 0.89 µg/√Hz, the bias instability of 490 µg, the input range of ±10 g, and the output nonlinearity of ±0.5 %FSO.

Bandwidth is an extremely valuable and scarce resource in a wireless network. Therefore, efficient bandwidth management is necessary in order to provide high qualify service to users with different requirements in a multimedia wireless/mobile network. In this paper, we propose an on-line bandwidth reservation algorithm that adjusts bandwidth reservations adaptively based on existing network conditions. The most important contribution of our work is an adaptive algorithm that is able to resolve conflicting performance criteria - bandwidth utilization, call dropping and call blocking probabilities. Our algorithm is quite flexible, is responsive to current traffic conditions in cellular networks, and tries to strike the appropriate performance balance between contradictory requirements for QoS sensitive multimedia services.

A simulation model of vibratory capacitive microgyroscope and its driving loop is designed using SPICE. The vibratory microgyroscope is basically microelectromechanical system; therefore the simulation model should be expressed mechanical and electrical properties. To modelling the microgyroscope, the Analog Behavioral Model is used. In order to design a driving loop of vibratory microgyrosope, the the Barkhausen criteria is considered. The co-simulation of MEMS sensing element and its interface circuit is performed. The SPICE simulation model of the vibratory microgyrocope is designed, and the driving loop of the microgyroscope is simulated using the designed simulation model. The simulation results demonstrate the validity of the designed model and its interface circuit

Transition metal fluorides are an appealing alternative to conventional intercalation compounds for use as cathodes in next-generation lithium batteries due to their extremely high capacity (3–4 times greater than the current state-of-the-art). However, issues related to reversibility, energy efficiency and kinetics prevent their practical application. Here we report on the synthesis, structural and electrochemical properties of ternary metal fluorides (M1yM21-yFx: M1, M2=Fe, Cu), which may overcome these issues. By substituting Cu into the Fe lattice, forming the solid–solution CuyFe1-yF2, reversible Cu and Fe redox reactions are achieved with surprisingly small hysteresis (, Transition metal fluorides have high theoretical specific capacities as cathodes for lithium ion batteries, but low working potentials and poor energy efficiency limit their practical applications. Here, the authors report a group of ternary metal fluorides, which may overcome these problems.