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Highly aligned GO gel fibers are fabricated under high extensional flow for efficient nanofluidic transport of ion species., Colloidal dispersions with liquid crystallinity hold great promise for fabricating their superstructures. As an example, when graphene oxide (GO) sheets are assembled in the liquid crystalline state, they can turn into ordered macroscopic forms of GO such as fibers via the wet spinning process. Here, we report that by reinforcing intersheet interactions, GO liquid crystals (LCs) turn into mechanically robust hydrogels that can be readily drawn into highly aligned fibrillar structures. GO hydrogel fibers with highly aligned sheets (orientation factor, f = 0.71) exhibit more than twice the ionic conductivity compared to those with partially aligned structures (f = 0.01). The hierarchically interconnected two-dimensional nanochannels within these neatly aligned GOLC hydrogel fibers may facilitate controlled transport of charge carriers and could be potentially explored as cables for interconnecting biosystems and/or human-made devices.

Solar assisted heat pump system is the heat pump system using solar thermal energy as a heat source of evaporator of the heat pump and most of these systems have been used ordinary solar collector that can get a thermal energy only from solar radiation. Thus, the hybrid solar collector that has air to water heat exchanger of fin-and-tube type have been developed for obtaining thermal energy from not only solar radiation but also ambient air. It is the flat plate solar collector installed fin-and-tube heat exchanger beneath absorbing plate. Thus the thermal energy obtained from ambient air can be supplied to evaporator of heat pump when the solar radiation is not enough. At this time, heat exchange performance between air and circulated water is one of most important factor. Hence, in this study, heat exchange performance of hybrid solar collector and effect of parameters that affect heat exchange performance were investigated experimentally. As a result, heat transfer rate between air and water was shown from 180 W to 820 W and it was increased linearly with increment of temperature difference between inlet air and water. In case of effectiveness, it was shown from 0.5 to 0.6 and it was increased by decrement of air mass flow rate independently on temperature difference between inlet air and water. From these results, heat exchange performance of the collector is considered as a sufficient capacity for applying for heat pump system and it also could be confirmed that optimal operation condition of solar assisted heat pump system integrated with hybrid solar collector need to be established base on the relationship obtained from this research as a further study.

A hybrid solar collector, in this study, means the flat plate solar collector that has fin-and-tube heat exchanger beneath absorbing plate. It was focused on the combination with heat pump system. Solar thermal energy obtained from the collector can be used as a heat source of evaporator of heat pump, and the C.O.P. (coefficient of performance) of heat pump can be increased because of the increment of evaporating temperature. In case of this hybrid solar collector, different with traditional collector, it can get a thermal energy from ambient air for heating circulated water when the solar radiation is not enough. Hence, the collector can supply thermal energy to evaporator of heat pump using heated water by ambient air or solar energy selectively depending on the weather. So, in this study, thermal performance of this collector on daily operation was investigated with various flow rate of water experimentally for confirming how much solar energy can be obtained by this collector in winter. As a result, maximum thermal efficiency was shown from 55% to 62% enough to make hot water according to mass flow rate even the fin-and-tube heat exchanger was installed beneath absorbing plate instead of insulator of traditional flat plate solar collector and it was increased with increment of flow rate. But the overall heat loss coefficient also increased similar with thermal efficiency and from those efficiency curves, it was confirmed that the optimal operating condition need to be investigated in the further study before applying to heat pump system.

White spot syndrome virus (WSSV), an important shrimp pathogen that can affect both salt- and freshwater shrimp, has a high mortality rate that can reach up to 100% in 3-10 days. Therefore, we assessed the susceptibility of Macrobrachium nipponense (De Haan, 1849), a freshwater prawn native to Korea, to artificial WSSV infection. Although rearing in water containing WSSV-infected carcasses did not result in infection, M. nipponense was infected with WSSV after being fed a WSSV-containing diet, per os infection, or injection with the purified virus. In the feeding test, the first mortality was observed on the 7th day and cumulative mortality reached 30% by 3 weeks post-infection. After per os infection, experimental animals started dying on the second day and within 3 weeks mortality had reached 90%. In the injection test, the mortality was found to be dose-dependent. Prawn injected with 2.5 × 104, 900 and 80 copies/g body weight exhibited the first mortality at 1, 2 and 4 days post inoculation, with 100, 100 and 50% final mortality at 2, 10 and 12 days post inoculation, respectively. Histological observation revealed inclusion bodies in the gills, antennal glands and other tissues of ectodermal origin. Real-time polymerase chain reaction revealed the increase of viral titers, indicating viral replication in the inoculated host. This forms the first report of the experimental susceptibility of M. nipponense to WSSV.

A hybrid solar collector, in this study, means the flat plate solar collector that has a fin-and-tube heat exchanger combining with a heat pump system. This collector can get the thermal energy from the ambient air for heating the circulated water in the collector when solar radiation is not enough. Thus, this collector can supply thermal energy to evaporator of the heat pump using heated water. For a foundation design of this collector, the numerical analysis was conducted for confirming the heat gain of water by the ambient air according to the length and the installation angle of fins in the fin-and-tube heat exchanger of solar collector. As a result, much of heat gain of water was obtained on the higher fin length with 30o of installation angle, but the pressure drop of air side increased adversely with heat transfer rate. Thus an area goodness factor considering both heat transfer enhancement and pressure drop of air side was also investigated. As a result, 50 mm of the fin length with 0o of installation angle has a good heat transfer enhancement than that of the other installation conditions compare with increment of pressure drop. However, mostly, higher heat transfer rate was obtained when the area goodness factor was low. So, it is needed to be considered whether the condition, maximum value of area goodness factor satisfying the heat transfer rate, can be expected or not.

Alimentary tract duplications are uncommon congenital anomalies containing a normal gastrointestinal mucosa and smooth muscle layer. Intestinal duplication in the jejunum is rare, and any malignancy arising in the jejunal duplication is extremely rare. In this report, we present the first case of papillary adenocarcinoma arising in a tubular duplication of the jejunum. Coronal reformatted images from contrast-enhanced CT revealed a well-enhanced tubular mass in the distal jejunum with small bowel obstruction. There were multiple enlarged lymph nodes in the small bowel mesentery around the superior mesenteric artery. The typical macroscopic and histological findings were present.

BACKGROUND AND PURPOSE: There have been inconsistencies on the prognosis and controversies as to the proper management of acute basilar artery dissection. The aim of this study was to evaluate acute basilar artery dissection and its outcome after management. MATERIALS AND METHODS: A total of 21 patients (mean age, 53 years; range, 24–78 years) with acute basilar artery dissection were identified between January 2001 and October 2007. Clinical presentation, management, and outcomes were retrospectively evaluated. RESULTS: The patients presented with subarachnoid hemorrhage (n = 10), brain stem ischemia (n = 10), or stem compression sign (n = 1). Ruptured basilar artery dissections were treated by stent placement with coiling (n = 4), single stent placement (n = 3), or conservatively (n = 3). Of the patients treated with endovascular technique, 6 had favorable outcome (modified Rankin scale [mRS], 0–2) and the remaining patient, who was treated by single stent placement, died from rebleeding. All 3 conservatively managed patients experienced rebleeding, of whom 2 died and the other was moderately disabled. Unruptured basilar artery dissections were treated conservatively (n = 7) or by stent placement (n = 4). Of the patients with unruptured basilar artery dissection, 9 had favorable outcome and the remaining 2 patients, both of whom were conservatively managed, had poor outcome because of infarct progression. The group with the ruptured basilar artery dissection revealed a higher mortality rate than the group with the unruptured dissection (30% vs 0%). The group treated with endovascular means revealed more favorable outcome than the group that was treated with conservative measures (90.9% vs 50%). CONCLUSION: The ruptured basilar artery dissections were at high risk for rebleeding, resulting in a grave outcome. Stent placement with or without coiling may be considered to prevent rebleeding in ruptured basilar dissections and judiciously considered in unruptured dissections with signs of progressive brain stem ischemia.

The purpose of this study was to determine the optimal bolus dose of remifentanil required for the successful insertion of the laryngeal mask airway during propofol induction in children without a neuromuscular blocking agent. Twenty-six paediatric patients, aged 3-10 years, requiring anaesthesia for short ambulatory surgery were recruited. A predetermined bolus dose of remifentanil was injected over 30 s, followed by propofol 2.5 mg.kg(-1) over 10 s. The bolus dose of remifentanil was determined by a modified Dixon's up-and-down method, starting from 0.5 microg.kg(-1) (0.1 microg.kg(-1) as a step size). Laryngeal mask insertion was attempted 90 s after the end of remifentanil injection and the response of patients was classified as either 'movement' or 'no movement'. The bolus dose of remifentanil at which there was a 50% probability of successful laryngeal mask insertion (ED(50)) during induction with 2.5 mg.kg(-1) propofol was 0.56 (0.07) microg.kg(-1) in children without a neuromuscular blocking agent. From probit analysis, the ED(50) and ED(95) of remifentanil were 0.52 microg.kg(-1) (95% confidence limits, 0.42-0.62 microg.kg(-1)) and 0.71 microg.kg(-1) (95% confidence limits, 0.61-1.40 microg.kg(-1)), respectively.

Effect of oxidation on transformation and deformation behavior was investigated in Ni-Ti alloy by comparing the as-oxidized specimen and the polished one. Ti's preferable reaction with oxygen results in the compounds such as Ni3Ti and Ni4Ti3, and the Ni-rich region between matrix and oxide. Martensitic transformation did not take place in the Ni-rich region due to the high Ni content while R phase transformation temperature decreased significantly. Oxidation deteriorated the superelasticity due to the formation of the compound as well as the Ni-rich region in which slip deformation occurs instead of induction of martensite.

This work is related to a SMA coil spring which shows perfect recovery and greater recovery force. When tension spring of common metals is fabricated, 'initial tension' can be provided by minus pitch winding. The initial tension is the force for tension springs to contract further in closed state. If a SMA spring has the initial tension, perfect recovery is expected with a greater recovery force. However, the initial tension cannot be given to SMA coils in the conventional way, since heat treatment for shape setting eliminates the tension generated by the minus pitch winding. We have developed a new method of supplying the initial tension to SMA springs by changing coil orientation after the shape setting treatment. In this paper, some examples are introduced that a perfect recovery with a greater force, though permanent deformation is involved in the deformation, can be attained by the initial tension.

Background and Objectives Twenty haemophiliacs were diagnosed as infected with human immunodeficiency virus 1 (HIV-1), 1 to 2 years after exposure to clotting factor 9 manufactured in Korea, beginning in early 1990. This study assessed the genetic relationships between viruses found in plasma donors and haemophiliacs. Materials and Methods Sequencing of the nef and pol genes of viruses from infected haemophiliacs, plasma donors whose plasma was used in domestic clotting factor manufacture, haemophiliacs infected outside Korea, and local controls were determined by nested polymerase chain reactions and direct DNA sequencing. Phylogenetic analysis was used to investigate the relationships among the sequences. Results Both plasma donors and the haemophiliacs were infected with a subclade of subtype B that is a founder effect lineage in Korea. Conclusion Our data indicate that HIV-1 transmission to 20 haemophiliacs occurred through intravenous injection of Korean-made clotting factor. Summary A clotting factor made in Korea from blood from cash-paid donors infected at least 20 haemophiliacs with HIV-1 subtype B.

In this work, a new method of measuring volume fraction of e martensite formed both by cooling and deformation using volume change and endothermic heat on e → γ transformation, respectively. The variation in the amount of e with grain size is determined for an Fe-21Mn alloy, and its influence on shape memory effect is investigated. As grain size increases, the amount of e martensite forming on cooling increases. However, with a decrease in grain size, more e is induced by deformation, improving shape memory effect.

This paper presents the identification of rotor support dynamic parameters. The final dynamical system equation using the Lagrange method is underdetermined; therefore, another set of equations is derived using same system equation with different rotating speed. Combining these two equation sets, an overdetermined algebraic equation is obtained, and the solution of the system equation can be obtained using the least squares method. The sensitivity analysis is performed to extract the optimized solution, which is considered to be insensitive to inherent measurement errors. The trigonometric terms of experimentally obtained orbit shapes can be utilized for analysis at varying rotor speeds after discussing the possibility of the proposed method. The accuracy of the proposed method is compared with estimated simulation parameters, and experimental results for the rotor rig are compared with previous known data.

Importance of alternative energy has been increasing due to environmental issues and lack of fossil fuels. In addition, heating cost that occupies from 30 to of the total production cost in the protected cultivation sector in Korea needs to be reduced for profitability and global competition. But, study on geothermal energy to solve these problems has not been activated for Korean protected cultivation. This study was conducted to develop an optimized geothermal exchange system through fundamental test of heat transfer characteristics in soil such as thermal diffusivity, changes in soil temperature during heating and cooling operations, and restorations of soil temperature after the heater was fumed off, These issues were investigated using computer simulation for different depths. The simulated characteristics were evaluated through controlled tests. Simulated characteristics of heat transfer in the soil at different depths showed a reasonable agreement with the results of the controlled tests. All of computer simulation and controlled tests, soil temperatures changed at 10cm and 20cm distance from pipe. but don`t change at more than 30cm distance. It means that distances of heat transfer of the soil ranged from 20 to 30cm a day. Based on these results, the optimum spacing between adjacent heat exchange pipes and the pitch were selected as 50 and 40cm, respectively.

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which electrical power is not available. The average solar radiation power is in Korea. In this study, the experimental system of the water pump driven by the radiation energy were designed, assembled, tested and analyzed fur realizing the solar powered water pump. Energy conversion ken radiation energy to mechanical energy by using n-pentane as operating material was done and the water pumping cycles were able to be continued. The quantity of the water pumped per cycle ranged from 2 L to 10 L depending on the level of the valve open area far the vapour supply. The average quantity was about 4,366 cc. The thermal efficiency was about . The pressure level of the n-pentane vapour in flash tank was about and that in the water tank was . The pressure in the condenser during cycles was maintained as about 70 kPa. The condensation of the n-pentane vapour in the water tank was increased with the cycles even though the internal and external insulation were done. Air tank performance was better with increasing of the water piston displacement and the water could be pumped with the water piston displacement becoming higher than 6,500 cc.

Phase field simulations of the microstructural evolution of the intermetallic compound (IMC) layer formed during isothermal soldering reactions between Sn-Cu solder alloys and a Cu substrate are presented. The simulation accounts for the fast grain boundary (GB) diffusion in the IMC layer, the concurrent IMC grain coarsening along with the IMC layer growth, and the dissolution of Cu from the substrate and IMC layer. The simulation results support the previous suggestions that the growth kinetics of the IMC layer during soldering is predominantly governed by the fast GB diffusion and the concurrent coarsening rate of the IMC grains. The IMC grain coarsening is initiated by a competitive growth of the IMC grains at the solder/IMC interface. It is also shown that the dissolution of Cu into an unsaturated solder reduces the coarsening rate of the IMC grains, consequently decreasing the temporal growth exponent of the IMC layer.

Background: Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models. Aim: Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model. Methods: Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1. the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed. Results: After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis. but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection. Conclusion: The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research. and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Knitted textile fabrics are usually produced on weft knitting machines. The basic mechanism of the machines to convert textile yarn into knitted fabric is called a latch needle cam system. A rigid-body model with five bodies is set up to analyse the motion of the needle of the latch needle cam system. The force element is modelled as a spring damper element between the needle butt and each virtual body on the cam curves. The spring constant is obtained from the cam angle, the friction coefficient and the stiffness of the needle. Numerical examples are given to show the path of the needle butt and the forces between the needle and the cams. For various rotational speeds of the cylinder, the maximum vertical and horizontal forces are obtained.

The South Korea Plateau is a complex of ridges, seamount chains, troughs and a basin. Detailed analysis of 12 019 line-km Chirp (2–7-kHz) subbottom profiles from the South Korea Plateau and the eastern continental slope of Korea reveals a distinctive zonal distribution of echo types depending systematically on seafloor morphology. Pelagites/hemipelagites (type I-2) and basement highs (type III-1) prevail on the ridge summits, seamount chains and the upper to middle part of the eastern continental slope of Korea, and are commonly bounded downslope by creeps (type III-3) and slides/slumps (type IV-1) that occur extensively over the entire slope areas of the ridges, seamount chains and eastern continental slope. The mass-movement deposits change downslope to debrites and turbidites (types II, III-2, IV-2 and IV-3) in the troughs and Onnuri Basin, suggesting successive downslope evolution from slide and slump to debris flow and turbidity current. The voluminous creeps, slides and slumps over the entire slope areas of the plateau and eastern continental slope, deeper than 300 m in water depth, were most likely generated by frequent seismic shakings.

Background: Downregulation of TGF-β receptors is implicated in colon cancer development. Inactivation of either of the two transmembrane serine/threonine kinases, TGF-β1 types I/II receptors, is now implicated in carcinogenesis, especially gastrointestinal carcinogenesis. Methods: We generated transgenic mice, called pS2–dnRII or ITF–dnRII, of which the dominant negative mutant of the TGF-β type II receptor was expressed under the control of tissue-specific promoters, the pS2 promoter for stomach and ITF for intestine. They were either infected with H.pylori (ATCC 43504 strain, CagA+ and VacA+) or administered with azoxymethane to determine the significance of loss of TGF-β signalling in gastrointestinal carcinogenesis. Results: Gastric adenocarcinoma developed in pS2–dnRII mice, whereas only chronic active gastritis was noted in wild-type littermates after 36 weeks of H.pylori infection. Mice lacking in TGF-β signalling specifically in the stomach showed a significantly higher proliferation cell nuclear antigen-labelling index when infected with H.pylori than wild-type littermates (P

The most important parameter for TV application of LCD is a fast switching time for the display of moving image. To achieve faster switching time, the novel LC single materials with large dielectric anisotropies (16∼20), high clearing temperatures (195.5 ∼ 237.4 °C), broad nematic ranges (up to 169.9 °C) and high birefringence (0.254–0.2200) were developed. KUR‐series LC mixtures blended these single materials having significantly higher clearing temperatures and dielectric anisotropy values compared with conventional LC mixture. Especially, their clearing temperatures are 10∼30 °C higher than their host mixture. These LC mixtures showing about 10ms of high‐speed switching time in TV/Monitor of TFT LCD, is short enough to be addressed in a single time frame of 60Hz (16.7 ms). The threshold voltage V th, was low enough to operate at a driving voltage of 5 V. The VHR values were found to be high enough for TFT‐LCD in wide temperature range. Our novel LC mixtures are suitable materials for the inclu...

This paper is concerned with the design and implementation of a magnetic damper system to reduce the vibration of a suspension system actively. A cylindrical-type electromagnetic actuator with a permanent magnet is analysed and an effective controller design is made. An accurate force analysis is carried out for the given system. An accurate transfer function for the total system is determined by experimental data using an error minimization method. For experiments, a simple suspension structure system is utilized, in which a magnetic damper composed of a permanent magnet and digital controller is attached. In order to drive the system, a bipolar power amplifier of the voltage control type is utilized. A stable and high speed control board is used to implement digital control logic for the given system. This paper shows that the magnetic damper system using a phase lead controller is excellent in reducing the vibration of a one-degree-of-freedom suspension system.

A new antireflective coating (ARC), amorphous carbon (C-ARC), substituted for inorganic ARC (SiON) is gaining attention in dynamic random access memory processing as devices scale down, requiring more fine control of submicron (

Semi-flexible copolyimides with various alkyl chain lengths (BTDA-ODA/CnMPD PIs) were newly synthesized in N-methyl-2-pyrrolidone from benzophenonetetracarboxylic dianhydride, 4,4′-oxydiphenylene diamine, and 3,5-diaminobenzoyl n-alkanoates. The films were rubbed with varying rubbing densities, and on the rubbed surface the alignment behavior of a nematic liquid-crystal (LC) was examined. LCs were always aligned along the rubbing direction either homogeneously or homeotropically, depending on the side chain length as well as the rubbing density. The results inform that flexible n-alkyl side groups in the copolyimide play a critical role to align LCs on the surface, and their role is strongly dependent on its length. In addition, thermal, optical, and dielectric properties were investigated.

Single crystalline and crack free potassium lithium niobate (KLN) single crystals with low Li content were grown by the Czochralski method. The crystal composition can be written as K 2.60 Li 1.17 Nb 5.44 O 15 (=K 2.95 Li 1.33 Nb 6.17 O 17 ) which contain relatively fewer Li ions than ferroelectric K 3 Li 2 Nb 5 O 15 crystals. All experimental results show that the deficiency of the Li ions in the KLN crystals strongly influences their physical properties. Especially, the as-grown crystals do not indicate any signature for a ferroelectric phase transition in contrast to the ferroelectric K 3 Li 2 Nb 5 O 15 crystals. However, due to ionic conduction, the temperature dependence of the dielectric constant of such KLN-2 crystals show a broad anomaly near 300°C. In addition, the existence of proton defects can be revealed by infrared absorption spectroscopy near 3500 cm -1 in as-grown crystals.

Fluoro-isothiocyanated three-ring and two-ring liquid crystal compounds has been synthesized. They showed remarkably high nematic-isotropic transition temperature, wide nematic temperature range, high dielectric and optical anisotropy, as well as a high-voltage holding ratio of 98 %, rating them suitable for AM-LCD applications.

Dielectric and electro-optic properties of phenyl ester FLC mixture have been studied in detail. Dielectric relatation spectroscopy was used to study the molecular dynamics and dipolar ordering. In the SmA* phase, this is accompanied by a sharp increase in the dielectric strength Δes on approaching Tc. At such high frequency (2 MHz) Δe is usually negative in the SmC* and SmA* phase. In the N* phase, at lower frequencies, Δe had a weakly positive value. In the SmC* phase, δe is positive and its maximum value is less than 0.1. The dielectric biaxiality is discussed as an order parameter of the tilted smectic phase. It is verified that if the tilt angle increases according to θ ∝ (TC − T)β, the biaxiality increases according to δe ∝ (TC − T)2β. A critical exponent for θ and δe are 0.27 and 0.54, respectively. The rotational viscosity γθ for soft mode is of 10 Nsec/m2 in the SmA* phase. The activation energy for the rotational dynamics of Goldstone mode is estimated to be 1.4 eV from an Arrhenius plot. Optical response time is of about 50 μs at room temperature in SmC* phase, and is on the order of 10 μs in the N* phase and almost independent of the applied field.

An efficient process for the preparation of poly(3-hydroxybutyrate) (PHB) microspheres with a narrow size distribution was developed. PHB was produced by a fed-batch culture of Ralstonia eutropha using fructose syrup as the sole carbon source. After autoclaving the bacteria, PHB granules, which accumulated in the cells, were isolated by a detergent/hypochlorite treatment and then spray-dried to obtain the microspheres. The diameters of the PHB microspheres ranged from 0.6 to 1.1 μm and the weight-average molecular weights were approximately 50 000 with polydispersity indexes of 5.0. The microspheres had a porous internal structure with an average porosity value of 72% and efficiently blocked UV light shorter than 220 nm. When isosorbide dinitrate was used as a model drug, the optimal drug loading concentration of the microspheres for controllable retardation was 3% (w/w). Almost 80% of the loaded drug (3%, w/w) was released within 12 h with typical sustained drug release behaviors.

An optically pumped caesium-beam frequency standard (known as the KRISS-1) has been constructed at the Korea Research Institute of Standards and Science (KRISS) and the first measurements of long-term frequency stability have been made. Two methods were used to make the frequency standard immune to variations in the environmental temperature: an F = 4 → F' = 3 (σ + π)-polarized laser was used as a pumping source, and the difference between two sequential error signals was used as a feedback signal in the digital servo loop. A frequency stability of σy(τ) = 2.5 × 10-14 at τ = 105 s for a temperature variation of 4 °C was achieved with the KRISS-1.

A multiple harmonic balance method is presented in this paper for obtaining the aperiodic steady-state solution of a piecewise-linear system. As the method utilizes general and systematic computational procedures, it can be applied to analyze the multi-tone or combination-tone responses for the higher dimensional nonlinear systems such as rotors. Moreover, it is capable of informing the stability of the obtained solution using Floquet theory. To demonstrate the systematic approach of the new method, the almost periodic forced vibration of an articulated loading platform (ALP) with a piecewise-linear stiffness is computed as an example.

High-resolution (Chirp, 2–7 kHz) reflection profiles in the Ulleung Basin (35–37°N) made it possible to classify the uppermost (ca. 50–70 m thick) sedimentary sequence into eleven discrete echo types. They are either (1) distinct (Echo Types IA, IB, IC, ID, IE, and IF), (2) indistinct (Echo Types IIA, IIB, and IIC), (3) hyperbolic (Echo Type III), or (4) combined (Echo Type IV).

The enthalpy of mixing of liquid AlMgZn ternary liquid alloys was determined in the temperature range between 883 and 933 K using a high temperature mixing calorimeter. An association model is used to calculate the thermodynamic mixing functions of the ternary alloys based on the thermodynamic properties of the binary bordering systems. The calculated values of the enthalpy of mixing show a good agreement with measured values within the range of experimental accuracy. The presence of additional ternary interactions or ternary associates in the liquid state could not be observed.

Summary form only given. Electromagnetic pulse (EMP) can be delivered to electronic equipment in two ways. One is through the application of radiated fields, and the other is through conduction along cables and wires. In this study, a high-voltage pulse generator using a spiral Blumlein Pulse Forming Line (PFL) was developed for the test of EMP effect by radiation and conduction. For the conduction test, a spiral strip Blumlein PFL with transformer oil is employed to generate high voltage (>300 kV) and long duration (50~ ns) pulse. The pulse shape of the experimental result matched well with computer simulation. High power ultrawide band pulse for the radiation test was generated by combining a tem horn antenna with the high voltage generator. The peak-to-peak value of electric field intensity of a radiated pulse is approximately 53 kV/m at a distance of 10 m away from the antenna. The pulse generation system will be used for the examination of effects of the electric fields and conducted pulse on the operation of electronic devices.

An ocean buoy, UBIM, deployed during the spring transition from February and May, 2010 reveals for the first time highly-resolved temporal variation of biochemical properties of the upper layer of the Ulleung Basin in the southwestern East/Japan Sea. Meteorological data shows the typical spring transition occurred during the mooring period, weakening of wind speed, increase in shortwave radiation, and change in total heat flux from net cooling to net heating. Power spectrum of chlorophyll fluorescence (CF) peaks at semidiurnal tidal, near-inertial, diurnal, and subtidal frequencies. The diurnal variation of CF is characterized by high CF during the daytime and low CF at night. Dissolved oxygen and CF are correlated with high (low) dissolved oxygen accompanied by high (low) CF, indicating the dissolved oxygen is mainly determined by biological activities. The time series measurement captured the onset of subsurface spring bloom at 30 m, and collocated temperature and current data gives an insight into a mechanism that triggers the onset of the spring bloom not documented so far. The entire mooring period can be divided into pre-bloom period from the beginning of the mooring to early April, and bloom period afterwards. Mean CF values during the pre-bloom and bloom periods are 0.9 μg L−1 and 1.9 μg L−1, respectively. Mean mixed layer depth (MLD) shoaled from 22 m during the pre-bloom period to 15 m during the bloom period. Despite of the increase in shortwave radiation, average PAR values at 20 m show lower value during the bloom period as compared to that during the pre-bloom period. Low-frequency modulation of MLD ranging from 10 m to 53 m during the entire mooring period is mainly determined by shoaling and deepening of isothermal (isopycnal) depths. Temperature structure in the upper 110 m is characterized by alternating uplifting and lowering of isotherms, which is caused by the placement of the mooring site on the cold (cyclonic) or warm side of the frontal jet, the East Korean Warm Current. The frontal variability is thought to be due to the low-frequency path variatio of the East Korean Warm Current. The occurrence of the spring bloom at 30 m is concomitant with the appearance of colder East Sea Intermediate Water (ESIW) at buoy UBIM that results in the subsurface cooling and the shoaling of isotherms to the shallower depth levels than those occurred during the pre-bloom period. It is suggested that the springtime spreading of the ESIW is one of the important factors that triggers the onset of subsurface spring bloom below the mixed layer. The time lag between the peaks of CF and the occurrence of the shallowest isothermal depths is about several days, which appears to be the timescale for the growth of phytoplankton.

An obstacle to broader implementation of aluminum alloys in transportation industries is the superior formability of less costly steel alloys. Enormous potential benefits in mass reduction for fuel economy improvements with light weight, nonferrous alloys have stimulated novel approaches to forming complex aluminum components. In this paper, planar anisotropy of the new Al50552 alloy containing a calcium(Ca)-based compound, which is so-called Eco Al5052, was evaluated experimentally. The planar anisotropy was then modeled with three plane stress yield criteria of different complexity and theory bases, i.e., Hill’48, Yld89 and Yld2000. The results indicate that different yield models distinctly affect the interpolation accuracy of the planar anisotropic behaviors. Yld2000 criterion exhibit better agreement with experimental data than those from Hill’48 and Yld89 criteria since it has great extensibility due to the larger number of the mechanical parameters incorporated.

Using isotope-resolved, two sector field mass spectrometric techniques we have identified and investigated quantitatively the energetics and kinetics (in particular the kinetic energy release, KER) of the spontaneous decay reactions C60–2m z+ → C60-2m-p(z-1)+ + Cp + with m = 0 or 1, z ranging from 3 to 6 and p = 2 and 4. The obtained KER results are not compatible with the properties expected for a single-step fissioning reaction as described by the liquid drop model. Therefore the present data had to be interpreted by a different fragmentation mechanism. This novel reaction sequence, termed auto charge transfer (ACT) reaction, is initiated by the statistically driven neutral C2 (or C4) evaporation followed by an electron transfer process from the receding C2 (or C4) fragment to the remaining highly-charged fullerene ion thereby leading finally to the two charged reaction products observed in the exit channel of the decay reaction. Moreover, in the case that a C2 + loss from C60z+ is occurring in...