• Asian-Australasian Journal of Animal Sciences
• /
• v.7 no.4
• /
• pp.517-522
• /
• 1994

Three experiments were carried out to evaluate the fermentation process and subsequent nutritional quality of silage made from dried and fresh barley straw with and without the addition of wet brewers' grains. The treatments were: 1 kg of dried straw with 600 g of water but no wet brewers' grains (I - 0) as a control, and the same straw mixed with 2 kg (I - 2), 3 kg (I - 3), 4 kg (I - 4), or 5 kg (I - 5) of wet brewers' grains as treatments in Experiment I; and 2 kg of fresh straw without wet brewers' grains (II - 0) as a control, and the same fresh straw mixed with 2 kg (II - 1), 4 kg (II - 2), 6 kg (II - 3), or 8 kg (II - 4) of wet brewers' grains as treatments in Experiment II. Each material prepared was ensiled in 5 L (vinyl) bag silos, and the silos placed in a chamber of $21^{\circ}C$ for 10 (Exp. I) or 7 (Exp. II) months. The fermentation quality and nutritive value of the barley straw silages produced were markedly improved by mixing them with wet brewers' grains. Increasing levels of wet brewers' grains caused on increase in fermentation quality. The in vitro dry matter digestibility of silages was also increased by adding wet brewers' grains. Two semi scale pilot silages, experiment III, prepared from dried and fresh barley straw mixed with wet brewers' grains were fed to wether sheep. These silages, which contained 50% barley straw and 50% wet brewers' grains by dry weight, were moderate apparent digestibility and supplied of about 50% TDN and DCP.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.7
• /
• pp.1092-1100
• /
• 2010

Bacteria, fungi, and protozoa inhabiting the rumen, the largest chamber of the ruminants' stomach, release large quantities of hydrogen during the fermentation of carbohydrates. The hydrogen is used by coexisting methanogens to produce methane in energy-yielding processes. This work shows, for the first time, a fundamental possibility of using a hydrogen-rich fermentation gas produced by selected rumen ciliates to feed a low-temperature hydrogen fuel cell. A biohydrogen fuel cell (BHFC) was constructed consisting of (i) a bioreactor, in which a hydrogen-rich gas was produced from glucose by rumen ciliates, mainly of the Isotrichidae family, deprived of intra- and extracellular bacteria, methanogens, and fungi; and (ii) a chemical fuel cell of the polymer-electrolyte type (PEFC). The fuel cell was used as a tester of the technical applicability of the fermentation gas produced by the rumen ciliates for power generation. The average estimated hydrogen yield was ca. 1.15 mol $H_2$ per mole of fermented glucose. The BHFC performance was equal to the performance of the PEFC running on pure hydrogen. No fuel cell poisoning effects were detected. A maximum power density of $1.66\;kW/m^2$ (PEFC geometric area) was obtained at room temperature. The maximum volumetric power density was $128\;W/m^3$ but the coulombic efficiency was only ca. 3.8%. The configuration of the bioreactor limited the continuous operation time of this BHFC to ca. 14 h.

• Journal of Biomedical Engineering Research
• /
• v.31 no.3
• /
• pp.234-239
• /
• 2010

We have developed and reported several micro-spikes for minimally invasive biopsy. This paper presents a diagnosis protocol for micro-spike biopsy using paraffin-based tissue collecting tool. Using the proposed tissue collecting tool, which has a negative micro-spike structure in a porous chamber, the biopsied tissue in a micro-spike is effectively detached. The proposed diagnosis protocol prevents the loss of tissues in a paraffin embedding and sectioning process. Hence, it is compatible with conventional histopathology without additional reagents and processes. The gastro-intestinal tissue of a pig is biopsied in an in vivo environment, and then it is detached from a micro-spike using the paraffin-based tissue collecting tool. A histopathological photomicrograph of the detached tissue is acquired with the proposed diagnosis protocol. The acquired image offers clinical quality. This result shows that the paraffin-based tissue collecting tool is applicable to the medical practice.

• Progress in Superconductivity
• /
• v.10 no.2
• /
• pp.99-102
• /
• 2009

We report our development of the fabrication process of sub-micron scale $Al-AlO_x-Al$ tunnel junction by using electron-beam lithography and double-angle shadow evaporation technique. We used double-layer resist to construct a suspended bridge structure, and double-angle electron-beam evaporation to form a sub-micron scale overlapped junction. We adopted an e-beam insensitive resist as a bottom sacrificing layer. Tunnel barrier was formed by oxidation of the bottom aluminum layer between the bottom and top electrode deposition, which was done in a separate load-lock chamber. The junction resistance is designed and controlled to be 50 $\Omega$ to match the impedance of the transmission line. The junctions will be used in the broadband shot noise thermometry experiment, which will serve as a link between the electrical unit and the thermodynamic unit.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1996.06a
• /
• pp.422-448
• /
• 1996

Low-temperature epitaxial growth of Si and SiGe layers of Si is one of the important processes for the fabrication of the high-speed Si-based heterostructure devices such as heterojunction bipolar transistors. Low-temperature growth ensures the abrupt compositional and doping concentration profiles for future novel devices. Especially in SiGe epitaxy, low-temperature growth is a prerequisite for two-dimensional growth mode for the growth of thin, uniform layers. UHV-ECRCVD is a new growth technique for Si and SiGe epilayers and it is possible to grow epilayers at even lower temperatures than conventional CVD's. SiH and GeH and dopant gases are dissociated by an ECR plasma in an ultrahigh vacuum growth chamber. In situ hydrogen plasma cleaning of the Si native oxide before the epitaxial growth is successfully developed in UHV-ECRCVD. Structural quality of the epilayers are examined by reflection high energy electron diffraction, transmission electron microscopy, Nomarski microscope and atomic force microscope. Device-quality Si and SiGe epilayers are successfully grown at temperatures lower than 600℃ after proper optimization of process parameters such as temperature, total pressure, partial pressures of input gases, plasma power, and substrate dc bias. Dopant incorporation and activation for B in Si and SiGe are studied by secondary ion mass spectrometry and spreading resistance profilometry. Silicon p-n homojunction diodes are fabricated from in situ doped Si layers. I-V characteristics of the diodes shows that the ideality factor is 1.2, implying that the low-temperature silicon epilayers grown by UHV-ECRCVD is truly of device-quality.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.9
• /
• pp.799-804
• /
• 2007

The behavior of spray emanating from an injector to be employed in a liquid-propellant thrust chamber is investigated by optical measurement techniques. The injector has eight holes, each of which has 30 cant angle from the center-axis with the diameter of 0.406 mm. In order to examine an atomization process according to the spray-generation conditions and the evolution along spray downstream, variational features in the velocity and size of droplets obtained through Dual-mode Phase Doppler An 799emometry (DPDA) are delineated and discussed together with instantaneous plane images captured by using Nd:Yag laser sheet beam. A categorization of spray-flow regime representing the atomization and turbulent nature is made through evaluating the non-dimensional parameters, i.e., Reynolds number and Weber number based upon the theoretical injection velocity. These qualitative and quantitative data of spray breakup will be a firm basis for the design of brand-new thruster

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.93-98
• /
• 2007

The air velocity flowing in inner combustion chamber of SCramjet is supersonic and the time of its stay is very short as a few milliseconds. Within this short time, fuel injection， air-fuel mixing, and combustion process should be accomplished. Several methods are suggested for mixing enhancement. Among these, cavity is selected to study for mixing characteristics. The numerical simulation is performed in the case of freestream Mach number of 2.5 and cavity located in front of fuel jet injection. 3 different sized cavities of the same length-height ratio were used in order to recognize the effect about cavity size. Also, the case without cavity was analyzed to find the effect of cavity. Used code compared with the result of experiment under identical conditions and it was verified. Through this comparison and verification, mixing enhancement by cavity size could be confirmed.

• Applied Chemistry for Engineering
• /
• v.29 no.4
• /
• pp.425-431
• /
• 2018

Composite particles of porous silica and cerium oxide nanoparticles blocking UV/blue light were prepared through a dry coating process. Various composite particles were prepared by varying conditions such as the mixing ratio of cerium oxide and silica, and the chamber rotating speed of mechano fusion system. The surface morphology of the composite particles was observed with SEM and the composition was analyzed using X-ray fluorescence (XRF). When the cerium oxide/silica composite particles were dispersed in water, the transparency and dispersion stability of the colloidal solution were improved. In addition, the fluidity and spreadability of the particle powder were enhanced by making composite particles. These results show that cerium oxide/silica composite particles can be used as functional cosmetic ingredients for UV/blue light protection.

• Progress in Superconductivity
• /
• v.5 no.2
• /
• pp.105-108
• /
• 2004

We have studied effects of in-situ annealing on the fabrication of superconducting MgB$_2$ thin films prepared by rf magnetron co-sputtering. The Films were deposited on A1$_2$O$_3$ (1102) substrates at room temperature by using Mg and B targets. To trap remnant $O_2$ gas in the chamber, we used 20 mtorr Af sputter-gas balanced with 5 mol % of H$_2$ gas. To enhance adhesion to the substrate a thin layer of B was deposited prior to the codeposition of Mg and B. After completion of the film deposition, an additional Mg layer was deposited on top to compensate for Mg loss during the subsequent in-situ annealing. We have investigated the effects of two most important annealing parameters that are the Mg-to-B composition ratio and the annealing temperature. The range of the Mg-to-B composition ratio was from 0.42 to 0.85, and that of the annealing temperature was 500 $^{\circ}C$∼750 $^{\circ}C$. The Best result was obtained for the composition ratio of about 10% Mg excess from the stoichiometry and the annealing temperature of 700 $^{\circ}C$. Based on these results, we obtained films with T$_{c}$ : 36.5 K by further refining the fabrication process.s.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.15 no.4
• /
• pp.229-233
• /
• 2015

Background: Although water chambers are often used as surrogate blood-warming devices to facilitate rapid warming of red blood cells (RBCs), these cells may be damaged if overheated. Moreover, filtered and irradiated RBCs may be damaged during the warming process, resulting in excessive hemolysis and extracellular potassium release. Methods: Using hand-held syringes, each unit of irradiated and leukocyte-filtered RBCs was rapidly passed through a water chamber set to different temperatures (baseline before blood warming, $50^{\circ}C$, $60^{\circ}C$, and $70^{\circ}C$). The resulting plasma potassium and free hemoglobin levels were then measured. Results: Warming RBCs to $60^{\circ}C$ and $70^{\circ}C$ induced significant increases in free hemoglobin (median [interquartile ranges] = 60.5 mg/dl [34.9-101.4] and 570.2 mg/dl [115.6-2289.7], respectively). Potassium levels after warming to $70^{\circ}C$ ($31.4{\pm}7.6mEq/L$) were significantly higher compared with baseline ($29.7{\pm}7.1mEq/L$; P = 0.029). Potassium levels were significantly correlated with storage duration after warming to $50^{\circ}C$ and $60^{\circ}C$ (r = 0.450 and P = 0.001; r = 0.351 and P = 0.015, respectively). Conclusions: Rapid warming of irradiated leukoreduced RBCs to $50^{\circ}C$ may not further increase the extracellular release of hemoglobin or potassium. However, irradiated leukoreduced RBCs that have been in storage for long periods of time and contain higher levels of potassium should be infused with caution.