• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.418-428
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• 2007

Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.86-88
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• 2001

An experiment was conducted to determine how broiler performance, feces and litter concentration of N can be maintained and whether NH3 gas concentration can be reduced with reducing dietary CP, adding ALUM(AL2(SO4)3.14H20) in litter and supplementing with amino acid and vitamin D in feed. The experiment was divided into a starter period(1 to 21d) and grower period(22 to 42d), each having three different CP with 90 birds per treatment of 3 replications. The CP treatments consisted of a mean CP of 23.0(control 71), 20.4 (72) and 18.0 (73) % for starter and 21.0(control 71),19.3 (72) and 17.0 (73) % for grower, respectively, but with similar amino acid levels as the control. Alum was mixed in each treatment except control treatment with 200g in kilogram litter(rice bran) weight. Results suggested that reducing CP below control in the diets fed during 3wks and 6wks slightly increased feed gain and slightly decreased feed intake and weight gain. However, there were no significant difference among treatments. Reducing CP caused NH3 gas concentration to decline by 74.8 - 80.9% when Alum was mixed in litter(P < 0.05). Litter N concentration did not show any difference(P > 0.05) among treatments. These results suggest that dietary manipulation with adding Alum in litter show for significant reducing NH3 gas concentration while maintaining acceptable Production performance from broiler.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.426-437
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• 2005

Statement of problem : Although zirconium oxide ceramics are more and more commonly used in restorative dentistry, for many clinical applications only limited data can be found in the literature. However it is quite clear that hydrofluoric acid etching is impossible with zirconia ceramics. Therefore, other bonding techniques are required in order to lute these materials adhesively. Purpose : The purpose or this study was to evaluate the effects of surface treatments on shear bond strengths between two resin cements and a zirconia ceramic. Materials and methods : Experimental industrially manufactured yttrium-oxide-partially-stabilized zirconia ceramic discs (Adens, Korea) were used for this study. The ceramic specimens divided into five experimental groups and a control group (as received). Five surface treatments were studied 1) sandblasting with 110$\mu$m $Al_2O_3$ at 3 bars pressure 13 seconds at a distance of 10 mm, 2) flame-treated with the Silano-Pen for 5 $s/cm^3$, 3) grinding with a diamond bur. 4) sandblasting + Silano-Pen treatment, 5) diamond bur preparation + Silano-Pen treatment. Acrylic plastic tube (5 mm in height and 3 mm in diameter) were filled with composite to fabricate composite cylinders The composite cylinders were bonded to the ceramic specimens with either Superbond C&B or Panavia F resin luting agents. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed 1mm/min; the maximum load at fracture was recorded. Sheat bond strength data were analyzed with oneway analysis of variance and Tukey HSD tests (P<.05). Treated ceramic surfaces and fracture surfaces after shear testing were examined morphologically using scanning electron microscope. Results: Ceramic surface treatment with Silano-Pen after sandblasting improved the bond strength of Superbond C&B resin cement. Supevbond C& B resin cement at Silano-Pen aiker sandblasting($27.4{\pm}3.8MPa$) showed statistically higher shear bond strength than the others. Conclusion: Within the limitation of this study, Superbond C& &B resin cement are suitable for cementation of zirconia ceramics and flame-treated with the Silano-Pen after sandblasting is required to enhance the bond strength.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.149-157
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• 2005

PFC(Perfluorocarbon) decontamination process is one of best methods to remove hot particulate adhered at inside surface of hot cell and surface of equipment in hot cell. It was necessary to develop a particulate filtration equipment to reuse PFC solution used on PFC decontamination due to its high cost and to minimize the volume of second wastewater. Contamination characteristics of hot particulate were investigated and then a filtration process was presented to remove hot particulate in PFC solution generated through PFC decontamination process. The removal efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic(Al$_{2}$O$_{3}$ filter showed more than 95$\%$. The removal efficiency of PVDF filter was a little lower than those of other kiters at same pressure(3psi). A ceramic filter showed a higher removal efficiency with other filters, while a little lower flux rate than other filters. Due to inorganic composition, a ceramic filter was highly stable against radio nuclides in comparison with PVDF and PP membrane, which generate H$_{2}$ gas in e-radioactivity atmosphere. Therefore, the adoption of ceramic filter is estimated to be suitable for the real nitration process.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.243-248
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• 1996

To find out the oxidation process of potential acid sulfate soil(PASS) along with time. the PASS were treated with lime and ammonia water to adjust soil pH in laboratory column condition. pH range of PASS showed 6.5 to 7.5. however, complete oxidized PASS by $H_2O_2$ showed 2.1 to 2.5. After pilling the PASS under the natural condition. oxidation occured slowly from surface of the pilled soil. The oxidation of PASS proceeded slowly when the soil was in submerged condition. but quickly in dried condition. The content of sulfide-sulfur in PASS sharply decreased after exposing to the air and the decreasing rate was greater in dried than in submerged condition. The content of sulfate-sulfur continuously decreased in submerged condition. but increased in dried condition. Contents of $Fe^{+{+}}$ and $Al^{+{+}}$ in PASS were generally increased with time and the increasing rate was greater in submerged than in dried condition. Liming to PASS was slowly acting to pH change and ammonia water caused fast pH change within a short period of time. The contents of sulfate-sulfur and exchangeable aluminum in drainage water decreased with time and the contents of sulfide-sulfur and ferrous iron were increased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.411-416
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• 2020

An optical arrangement has been set inside a photo-spectrometer to measure the reflectance of IR optics materials in mid IR range. The optical arrangement consists of equally spaced 4 gold coated full reflecting mirrors with the incidence angle of 45°. Baseline beam intensity I_B has been measured while the beam proceeds through the 4 mirrors. Reflectance of a mirror has been estimated from the I_B. And the beam intensity I_S with the specimen in the optical path has been measured with the 4th mirror replaced with the specimen. Reflectance of the specimen has been estimated from the value of I_S/I_B. Then the estimated reflectance has been put in Fresnel equation relating reflectance and refractive index(RI) to estimate the RI of the material. Measurement has been made for sapphire, germanium, magnesium fluoride, and zinc sulfide. The estimated RI of the materials are closely matching with reference data and the maximum difference less than 2% over the wavelength range 3-5㎛ for all materials tested. As an FT-IR photo-spectrometer with a broadband wavelength infrared light source is used, this method has the advantage of measuring the refractive index at multiple wavelengths in a single measurement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.553-560
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• 2021

In this study, cement clinker using a pure sample and clinker using 7% coal ash were sintered at a temperature of 1050~1500℃. Changes in the content of cement minerals and changes in microstructure by sintering temperature were reviewed. The application of coal ash as a raw material for cement clinker was applicable as a source of Al₂O₃ and SiO₂. At a sintering temperature of 1350℃ or higher, the cement clinker applied with coal ash showed the same level of mineral content as compared to the cement clinker applied with pure raw material. The microstructure also showed a similar state, confirming that coal ash can be used as a raw material for cement. In XRD-Reitveld analysis, a maximum amount of Belite was produced at 1250℃. The conversion from Belite to Alite was observed from 1350℃. From 1350℃, the interstitial phase and the mineral phase presumed to be alite were distinguished. It was clearly distinguished from 1400℃. As the sintering temperature increased, the shape and boundary of the crystal phase became clear, and the size of the crystal phase was also increased.

• Journal of Powder Materials
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• v.16 no.6
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• pp.431-437
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• 2009

Various inorganic fillers improve the thermal conductivity and physical properties of organic products. Alumina has been used a representative filler in the heat radiation sheet for the heat radiation of electric device. The high filling rate of alumina increases the thermal conductivity and properties of products. We successfully developed the spherical alumina by flame fusion process using the oxygen burner with LPG fuel. In the high temperature flame (2500$\sim$3000$^{\circ}C$) of oxygen burner, sprayed powders were melting and then rotated by carrier gas. This surface melting and rotation process made spherical alumina. Especially effects of chemical composition and particle size of stating materials on the melting behavior of starting materials in the flame and spheroidization ratio were investigated. As a result, spheroidization ratio of boehmite and aluminum hydroxide with endothermic reaction of dehydration process was lower than that of the sintered alumina without dehydration reaction.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4347-4351
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• 2012

Background: Breast cancer is the most common cancer of women and the principal cause of death in middle aged women. The objective of this study was to describe the trend of breast cancer and its management in Aden and adjacent south-eastern governorates of Yemen during the last 20 years. Patients and Methods: This is a retrospective analysis of previous studies on patients with breast cancer in Aden and adjacent south-eastern governorates, Yemen (January 1989 through December 2007). The studied variables were: sex, age, time and type of presentation, disease stage, pathological types and the performed surgical treatment. The sources of information were the treatment registry of Aden health office, archives of Al-Gamhouria teaching hospital; major referral and other public and private hospitals in Aden and Aden Cancer Registry. Results: The total number of patients was 476, 99% being females. The age range was 19-88 years. The most affected age was 30-50 years (60.5%), 95% presenting after one month of having breast symptoms. Forty-five percent presented with signs of advanced local disease, while 59.2% had palpable axillary lymph nodes on presentation. Early breast cancer (stages I-II) occurred in 47%, and late breast cancer (stages III-IV) in 51.5%. Invasive ductal carcinoma was the commonest pathology (89.3%). The main surgical treatment was mastectomy (modified radical mastectomy (50%). Conclusion: Breast cancer is predominantly a disease of young with late presentation and advanced disease. Improving health awareness and earlier diagnosis of the disease by health education, encouraging breast self-examination, and providing the mammography equipment and mammary clinics in hospitals are recommended. Establishment of oncology and radiotherapy centers in Aden is a necessity.

• Journal of Astronomy and Space Sciences
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• v.36 no.4
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• pp.265-281
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• 2019

We present new BVRI light curves of UY UMa with no O'Connell effect and a flat bottom secondary eclipse. Light curve synthesis with the Wilson-Devinney code gives a new solution, which is quite different from the previous study: UY UMa is an A-subtype over-contact binary with a small mass ratio of q = 0.21, a high inclination of 81°.4, a small temperature difference of ΔT=18°, a large fill-out factor of f = 0.61, and a third light of approximately 10% of the total systemic light. The absolute dimensions were newly determined. Seventeen new times of minimum light have been calculated from our observations. The period study indicates that the orbital period has intricately varied in a secular period increase in which two cyclical terms with periods of 12^y.0 and 46^y.3 are superposed. The secular period increase was interpreted to be due to a conservative mass transfer of 2.68 × 10^-8 M_⊙/yr from the less massive to the more massive star. The cyclical components are discussed in terms of double-light time contributions from two additional bound stars. The statistical relations of Yang & Qian (2015) among the physical parameters of 45 deep, low mass ratio contact binaries were revisited by using the physical parameters of UY UMa and 25 Kepler contact binaries provided by Şenavci et al. (2016).