• The Bulletin of The Korean Astronomical Society
• /
• v.25 no.2
• /
• pp.110-110
• /
• 2000

• Bulletin of the Korean Space Science Society
• /
• 2000.10a
• /
• pp.110-110
• /
• 2000

No Abstract, See Full Text

• Korean journal of food and cookery science
• /
• v.10 no.2
• /
• pp.138-141
• /
• 1994

Whole, peeled sweetpotatoes were subjected to four different processes: 15 min microwave heating followed by 15 min baking (1), 90 min baking (2), 15 min microwave heating (3), and 15 min boiling followed by 15 min microwave heating (4). Samples of green and cured roots were used in the study. Scanning electron photomicrographs revealed that cured roots contained larger numbers of starch granules in the parenchyma cells than green roots, most of them compounded. The starch in cooked green roots was gelatinized while for cured roots it was mostly hydrolyzed into dextrins and sugars. Starch in process (3) roots was mostly gelatinized while in process (1) and process (2) roots gelatinized starch appeared in little quantity, thus it was primarily converted to dextrins and sugars. The process (4) resulted in little conversion of starch. The process (1) product resulted in a similar product to the process (2) product.

• Journal of the Korean Ceramic Society
• /
• v.35 no.5
• /
• pp.465-471
• /
• 1998

Lead titanate(PT) and lead magnesium niobate(PMN) ceramic powders were prepared by microwave hy-drothermal method using teflon bomb. Raw materials were Pb(NO3)2 and TiO2 for lead titanate and Pb(NO3)2 Nb2O5 and Mg(NO)3.6H2O for PMN with NaOH as mineralizer in both cases. in lead titanate synthsis rate of microwave hydrothermal method was faster three times than one f conventional hydrothermal methods In lead magnesium niobate synthsis the mixture of perovskite and pyrochlore phases was obtained by single step technique and the PMN was not obtained by double step technique due to low temperature limitation of teflon bomb.

• Culinary science and hospitality research
• /
• v.5 no.2
• /
• pp.193-210
• /
• 1999

This article try to show the results from three cooking methods of a steak in 150 g by way of roasting cooking, braising cooking, microwave cooking. I observed the cooking time, standing time and post processing temperature rice of three steaks coming to 70 $^{\circ}C$ by means of roasing, braising and microwave, respectively, The results are shown in the followings: It is shown that Microwave cooking takes the shortest cooking time and the longest standing time in each cooking intervals and also shows the high level of losses and that of drip losses as well. It is concluded that there are not much differences among the ingredients of steaks cooked in three methods but the steak cooked in microwave cooking method is shown to be low in fat containment of it.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.4
• /
• pp.954-957
• /
• 1999

The changes in L ascorbic acid content by processing treatments; gamma irradiation, heating and microwave were investigated using high performance liquid chromatography. The content of L ascorbic acid in standard solutions and citrus fruits decreased from 27.4 to 44.9% and from 6.9 to 21.9%, re spectively, by gamma irradiation doses in the range of 1 to 10 kGy. By heating treatments, L ascorbic acids in standard solutions and citrus fruits were destroyed 22.5 to 36.8% and 4.5 to 18.1%, respectively. By microwave treatment, L ascorbic acid content also decreased from 23.1 to 47.4% and from 6.5 to 22.6%, respectively.

• Korean Journal of Metals and Materials
• /
• v.50 no.5
• /
• pp.389-393
• /
• 2012

Improvement in microwave absorbance has been investigated by insertion of a periodic air cavity in rubber composites filled with magnetic powders. A mixture of $Co_2Z$ hexagonal ferrite and Fe powders were used as the absorbent fillers in silicone rubber matrix. The complex permeability and complex permittivity of the magnetic composites were measured by reflection/transmission technique. In the grid-type magnetic absorbers, the equivalent permeability (${\mu}_{eq}$) and permittivity (${\varepsilon}_{eq}$) are calculated as a function of air volume rate (K) on the basis of effective medium theory. Reduction in the material parameters (especially, dielectric permittivity and magnetic loss) has been estimated with the increase of K. Plotting the ${\mu}_{eq}$ and ${\varepsilon}_{eq}$ on the solution map of wave-impedance matching, wide bandwidth microwave absorbance has been predicted in the magnetic composites with an optimum value of K.

• International Journal of Computer Science & Network Security
• /
• v.22 no.1
• /
• pp.121-128
• /
• 2022

There are much processing techniques of microwave circuits, whose dimensions are small compared to the wavelength, but the disadvantage is that they cannot be directly applied to circuits working at high and/or low frequencies. In this article, we will consider the bond graph approach as a tool for analyzing and understanding the behavior of microwave circuits, and to show how basic circuit and network concepts can be extended to handle many microwaves analysis and design problems of practical interest. This behavior revealed in the scattering matrix filter, and which will be operated from its reduced bond graph model. So, we propose in this paper, a new application of bond graph approach jointly with the scattering bond graph for a high frequency study.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.218.1-218.1
• /
• 2014

In order to measure the absolute plasma density, various probes are proposed and investigated and microwave probes are widely used for its advantages (Insensitivity to thin non-conducting material deposited by processing plasmas, High reliability, Simple process for determination of plasma density, no complicate assumptions and so forth). There are representative microwave probes such as the cutoff probe, the hairpin probe, the impedance probe, the absorption probe and the plasma transmission probe. These probes utilize the microwave interactions with the plasma-sheath and inserted structure (probe), but frequency range used by each probe and specific mechanisms for determining the plasma density for each probe are different. In the recent studies, behaviors of each microwave probe with respect to the plasma parameters of the plasma density, the pressure (the collision frequency), and the sheath width is abundant and reasonably investigated, whereas relative diagnostic characteristics of the probes by a comparative study is insufficient in spite of importance for comprehensive applications of the probes. However, experimental comparative study suffers from spatially different plasma characteristics in the same discharge chamber, a low-reproducibility of ignited plasma for an uncertainty in external discharge parameters (the power, the pressure, the flow rate and so forth), impossibility of independently control of the density, the pressure, and the sheath width as well as expensive and complicate experimental setup. In this paper, various microwave probes are simulated by finite-different time-domain simulation and the error between the input plasma density in FDTD simulations and the measured that by the unique microwave spectrums of each probe is obtained under possible conditions of plasma density, pressure, and sheath width for general low-temperature plasmas. This result shows that the each probe has an optimum applicable plasma condition and reliability of plasma density measurement using the microwave probes can be improved by the complementary use of each probe.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.3
• /
• pp.390-397
• /
• 2022

The use of microwaves as the energy source for synthesis and sintering of ceramics offers substantial advantages compared to conventional gas-fired and electric resistance furnaces. Benefits include much shorter processing times and reaching the sintering temperature more quickly, resulting in superior final product quality. Most oxide ceramics poorly interact with microwave irradiation at low temperatures; thus, a more complex setup including a susceptor is needed, which makes the whole process very complicated. This investigation pursued a new approach, which enabled us to use microwave irradiation directly in poorly coupled oxides. In many solid-state electrochemical devices, the support is either metal or can be reduced to metal. Metal powders in the support can act as an internal susceptor and heat the entire cell. Then sufficient interaction of microwave irradiation and ceramic material can occur as the sample temperature increases. This microwave heating and exothermic reaction of oxidation of the support can sinter the ceramic very efficiently without any external susceptor. In this study, yttria stabilized zirconia (YSZ) and a Ni-YSZ cermet support were used as an example. The cermet was used as the support, and a YSZ electrolyte was coated and sintered directly using microwave irradiation without the use of any susceptor. The results were compared to a similar cell prepared using a conventional electric furnace. The leakage test and full cell power measurement results revealed a fully leak-free electrolyte. Scanning electron microscopy and density measurements show that microwave sintered samples have lower open porosity in the electrode support than conventional heat treatment. This technique offers an efficient way to directly use microwave irradiation to sinter thin film ceramics without a susceptor.