• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.437-440
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• 1998

We studied phosphorus doping effect on the epitaxial growth of $Si_{1-x}Ge_{x}$ film with high Ge fraction on Si substates at 550.deg. C by LPCVD. In a low $Ph_{3}$ partial pressure region such as below 1.25 mPa, the phosphorus dopant concentration increased linearly with increasing $PH_{3}$ partial pressure while the deposition rate and the Ge fraction were constant. In a higher $PH_{3}$ partial pressure region, the phosphorus dopant concentration and the deposition rate decreased, while the Ge fraction slightly increased. The deposition arate and the Ge fraction increased with increasing $GeH_{4}$ partial pressure while the phophours dopant concentration decreased. But the increasing rate of Ge fraction with incrasing $PH_{3}$ partial pressure was reduced at a high $GeH_{4}$ partial pressure. According to test results, it suggests that high surface coverage of phosphorus atoms suppress both the $SiH_{4}$ adsorption/reasction and the $GeH_{4}$ adsorption/reaction on the surfaces, and the effect is more stronger on $SiH_{4}$ than on $GeH_{4}$. In a higher $PH_{3}$ partial pressure region, the epitaxial growth is largely controlled by surface coverage effect of phosphorus atoms. The phosphorus surface coverage was slimited at a high $GeH_{4}$ partial pressure because adsorbed Ge atoms effectively suppresses the adsorption of phosphorus atoms.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.59-65
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• 2005

A phosphate recovery system from artificial wastewater was developed using a completely mixed phosphorus crystallization reactor, in which powdered converter slag was used as a seeding crystal. In preliminary test, the optimal pH range for meta-stable hydroxyapatite crystallization for high phosphorus concentration was observed to be 6.0 to 7.0, which was different from the conventionally known pH range (8.0~9.5) for effective crystallization in relatively low phosphorus concentration less than 5 mg/L. The average phosphorus removal efficiency in a lab-scaled completely mixed crystallization system for artificial wastewater with about 100 mg/L of average $PO_4-P$ concentration was shown to be 60.9% for 40 days of lapsed time. XRD analysis exhibited that crystalline of hydroxyapatite formed on the surface of seed crystal, which was also observed in SEM analysis. In EDS mapping analysis, composition mole ratio (=Ca/P) of the crystalline was found to be 1.78, indicating the crystalline on the surface of seed crystal is likely to be hydroxyapatite. Particle size distribution analysis showed that average size of seed crystal increased from $28{\mu}m$ up to $50{\mu}m$, suggesting that phosphorus recycling from wastewater with high phosphorus concentration can be successfully obtained by using the phosphorus crystallization recovery system.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.197-202
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• 1999

Three barrows weighing 45.0 kg, fitted with simple T-cannulas in both the duodenum and terminal ileum, were assigned to diets in a $3{\times}3$ Latin Square design experiment to determine the effect of two calcium levels (0.8% vs 0.4%) on phytase activity and nutrient balance in growing pigs. The control diet contained 0.8% calcium, with no added inorganic phosphorus (0.45% total phosphorus) and no added phytase. The two additional experimental diets contained microbial phytase (750 phytase units/kg) and supplied either 0.8% or 0.4% calcium. With added microbial phytase, ileal and total tract digestibility of rotal phosphorus were improved by 20.9 and 13.8 percentage units, respectively (p=0.01). The apparent duodenal and ileal digestibility of phytate phosphorus were increased by 51.8 and 49.7 percentage units (p=0.01). Lowering dietary calcium in the presence of microbial phytase increased the digestibility of phytate phosphorus by an additional 10.9 (p=0.001) and 5.7 percentage units for duodenal and ileal digestibility, respectively. Supplementation with microbial phytase significantly reduced fecal excretion of nitrogen and phosphorus and increased the percentage of these nutrients retained by the pig. Lowering dietary calcium further increased the percentage of dietary phosphorus retained. Overall, reducing dietary calcium appeared to increase the effectiveness of added microbial phytase in degrading phytate phosphorus. As a result, care should be taken to avoid high levels of dietary calcium when supplementing swine diets with microbial phytase.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.916-921
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• 2009

This study was aimed to both enhance the fluoride removal and to reduce the phosphorus removal in treating semiconductor wastewater using $Ca(OH)_2$ at low pH so as to facilitate struvite crystallization reaction. The struvite crystallization could be introduced after fluoride removal by retaining the phosphorus source. As the results, the method applied in this study achieved high fluoride removal efficiency (about 91%) with retardation of phosphorus removal at pH 4, compared to conventional methods where the removal of fluoride and phosphorus were done at pH 11. Therefore, the fluoride removal at low pH would contribute to the enhancement of nitrogen and phosphorus removals in a consecutive struvite crystallization reactor. Treatment of semiconductor wastewater at low pH using $Ca(OH)_2$ also had lower (about 20%) water content of precipitated sludge compared to conventional method. As the molar ratio of Ca to F increased the removal efficiencies of fluoride and phosphorus increased. Although the amount of seed dosage didn't affect the removal of fluoride and phosphorus, its increase reduced the water content of precipitated matter. Finally, considering consecutive struvite reaction, the optimum condition for the removal of fluoride and phosphorus was as follow: pH: 4, the molar ratio of Ca:F: 1:1.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.896-903
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• 2019

Objective: Qianbei-Pockmarked goats are affected by a disorder locally referred to as 'Ruanguzheng Disorder', which is characterized by emaciation, lameness, muscular relaxation, stiffness of the extremities, and abnormal curvatures of the long bones. Our objective was to determine the relationship between the disorder and phosphorus deficiency. Methods: Tissue samples were collected from affected and healthy animals, while soil and herbage samples were collected from affected and healthy pastures. Biochemical parameters were determined using an automatic biochemical analyzer (OLYMPUS AU 640, Olympus Optical Co., Tokyo, Japan). Mineral contents in soil, forage, and tissue were determined using a Perkin-Elmer AAS5000 atomic absorption spectrophotometer (Perkin-Elmer, Norwalk, CT, USA). Results: The results showed that phosphorus contents in herbages from affected pastures were markedly lower than those from healthy areas (p<0.01), and the ratio of calcium to phosphorus in the affected herbages was 12.93:1. The phosphorus contents of wool, blood, tooth, and bone from affected animals were also markedly lower than those from healthy animals (p<0.01). Serum phosphorus values in affected animals were much lower than those in healthy animals, while serum alkaline phosphatase values from affected animals were markedly higher than those from healthy animals (p<0.01). Inorganic phosphorus values from affected animals were approximately half of that in the control group. Supplementation of disodium hydrogen phosphate prevented and cured the disorder. Conclusion: This study demonstrates that Ruanguzheng disorder in Qianbei-Pockmarked goats is primarily caused by phosphorus deficiencies in herbage due to fenced pastures and natural habitat fragmentation.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.89-95
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• 2006

This study was conducted to improve an effect of phosphorus removal using FNR(Ferrous Nutrient Removal) process which had iron precipitation reactor and to analyze the iron corrosion. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. In this study, The removal efficiency of phosphorus increased with an increase voltage in iron precipitation reactor. The distance of 15mm between the two iron bed in each tests influence the concentration of remaining phosphorus most. The extensive surface area of iron bed is the more removes the phosphorus. In this test the $400\;cm^2$ of surface area was proved to be the most removal efficient.

• Korean Journal of Poultry Science
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• v.23 no.4
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• pp.169-175
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• 1996

An experiment was conducted with male broiler chicks to determine the effect of different dietary phosphorus sources and evaluate the biological availability of phosphorus sources. The biological availability of phosphorus from dicalcium phosphate (DCP) was used as a reference standard (100%) compared to defluorinate phosphate (DFP). DCP and DFP was supplemented to a corn-soy basal diet at levels of 0.05, 0.15, 0.25, 0.35%. Each of 24 pens of 10 male broiler chicks with three replications was used for three weeks. The results indicated that weight gain, feed in-take, feed efficiency, nonphytic phosphorus (NPP) and tibia ash were significantly different among treatments. Dietary supplemental phosphorus of DFP improved weight gain, NPP intake and feed efficiency consistently, whereas supplements of DCP did not show consistent increase. Regression equations was used for the availability of DPP compared with DCP when percent bone ash was a function of total phosphorus in the diet. The percent (%) bone ash of DFP groups compared to that of DCP groups showed a value of 59.98% as a slope ratio. DFP indicated lower biological availability compared to DCP, but it's dietary supplementation tended to increase bone ash and maximize the growth of young broiler chicks.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.122.1-122.1
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• 2011

Phosphorus is known to pile-up at the silicon surface when it is thermally oxidized. A thin layer, about 40nm thick from the silicon surface, is created containing more phosphorus than the bulk of the emitter. This layer has a gaussian profile with the peak at the surface of the silicon. In this study the pile-up effect was studied if this layer can act as a front surface field for solar cells. The effect was also tested if its high dose of phosphorus at the silicon surface can lower the contact resistance with the front metal contact. P-type wafers were first doped with phosphorus to create an n-type emitter. The doping was done using either a furnace or ion implantation. The wafers were then oxidized using dry thermal oxidation. The effect of the pile-up as a front surface field was checked by measuring the minority carrier lifetime using a QSSPC. The contact resistance of the wafers were also measured to see if the pile-up effect can lower the series resistance.

• Journal of Powder Materials
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• v.27 no.1
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• pp.31-36
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• 2020

Phosphorus is an element that plays many important roles in powder metallurgy as an alloy element. The purpose of this study is to investigate the influence of phosphorus addition on the microstructures and mechanical properties of sintered low-alloy steel. The sintered low-alloy steels Fe-0.6%C-3.89%Ni-1.95%Cu-1.40%Mo-xP (x=0, 0.05, 0.10, 0.15, 0.20%) were manufactured by compacting at 700 MPa, sintering in H₂-N₂ at 1260 ℃, rapid cooling, and low-temperature tempering in Ar at 160 ℃. The microstructure, pore, density, hardness, and transverse rupture strength (TRS) of the sintered low-alloy steels were evaluated. The hardness increased as the phosphorus content increased, whereas the density and TRS showed maximum values when the content of P was 0.05%. Based on microstructure observation, the phase of the microstructure changed from bainite to martensite as the content of phosphorus is increased. Hence, the most appropriate addition of phosphorus in this study was 0.05%.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.468-473
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• 2010

The purpose of this study is to derive the correlation between the Specific Phosphorus Release Rate (SPRR), Specific Phosphorus Uptake Rate (SPUR) and Specific Oxygen Uptake Rate (SOUR) at various Sludge Retention Time (SRT) condition in the A/O process. The laboratory scale reactor was operated on various SRT (10 day, 20 day, 30 day, 40 day). In this study, the SPRR, SPUR and SOUR tended to decrease with the SRT increase. Empirical equations was be obtained $y=4.54E-006x^2+0.0007x-0.0315$, $R^2=0.925$ (SOUR vs. SPRR) and $y=3.22E-006x^2+0.0004x-0.0173$, $R^2=0.928$ (SOUR vs. SPUR) from the relationship between SRT, SPRR and SPUR and SOUR. Therefore, the anaerobic tank design based on the research result such as SPRR, SPUR of a phosphorus design and SOUR would be possible.