• Korean Journal of Microbiology
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• v.25 no.2
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• pp.129-136
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• 1987

Nitrogen fixing activity associated with 40 varieties of rice was assayed at heading stage by an in situ acetylene reduction method. The in situ acetylene reduction activity and population of nitrogen fixing bacteria obtained on nitrogen-free malate medium for Azospirillum spp. enrichment showed positive correlation. Six Azospirillum spp. with high nitrogenase activity were isolated from the rice roots, from which five spp. were identified as A. lipoferum and one was A. brasilense. The physiological characteristics of the six Azospirillum isolates, that is, carbon source utilization, biotin requirement, antibiotic resistance, indole acetic acid excretion, plasmid profile and protein patterns were compared.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.537-542
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• 2002

A study was conducted to evaluate the nutritive potential value of different aquatic plants: duckweed (Lemna trisulaca), duckweed (Lemna perpusila), azolla (Azolla pinnata) and water-hyacinth (Eichhornia crassipes) from Bangladesh. A wide variability in protein, mineral composition, gas production, microbial protein synthesis, rumen degradable nitrogen and in situ dry matter and crude protein degradability were recorded among species. Crude protein content ranged from 139 to 330 g/kg dry matter (DM). All species were relatively high in Ca, P, Na, content and very rich in K, Fe, Mg, Mn, Cu and Zn concentration. The rate of gas production was highest in azolla and lowest in water-hyacinth. A similar trend was observed with in situ DM degradability. Crude protein degradability was highest in duckweed. Microbial protein formation at 24 h incubation ranged from 38.6-47.2 mg and in vitro rumen degradable nitrogen between 31.5 and 48.4%. Based on the present findings it is concluded that aquatic species have potential as supplementary diet to livestock.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.14-21
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• 2010

Ge is one of the attractive channel materials for the next generation high speed metal oxide semiconductor field effect transistors (MOSFETs) due to its higher carrier mobility than Si. But the absence of a chemically stable thermal oxide has been the main obstacle hindering the use of Ge channels in MOS devices. Especially, the fabrication of gate oxide on Ge with high quality interface is essential requirement. In this study, $HfO_xN_y$ thin films were prepared by plasma-enhanced atomic layer deposition on Ge substrate. The nitrogen was incorporated in situ during PE-ALD by using the mixture of nitrogen and oxygen plasma as a reactant. The effects of nitrogen to oxygen gas ratio were studied focusing on the improvements on the electrical and interface properties. When the nitrogen to oxygen gas flow ratio was 1, we obtained good quality with 10% EOT reduction. Additional analysis techniques including X-ray photoemission spectroscopy and high resolution transmission electron microscopy were used for chemical and microstructural analysis.

• Advances in nano research
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• v.9 no.1
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• pp.25-32
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• 2020

In this work, we report the use of caffeine as an alternative source of nitrogen to successfully dope graphene (quaternary 400.6 eV and pyridinic at 398 eV according XPS), as well as the growth of silver nanowires (in-situ) in the surface of nitrogen doped graphene (NG) sheets. We used the improved graphene oxide method (IGO), chemical reduction of graphene oxide (GOx), and impregnation with caffeine as source of nitrogen for doping and subsequently, silver nanowires (NW) grow in the surface by the reduction of silver salts in the presence of NG, achieving a numerous of growth of NW in the graphene sheets. As supporting experimental evidence, the samples were analyzed using conventional characterization techniques: SEM-EDX, XRD, FT-IR, micro RAMAN, TEM, and XPS.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.558-566
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• 2018

The objective of the study was to determine nutrition regime and limitation in the Boryeng Reservoir where there's a water tunnel between Geum River and the reservoir. Evaluation was conducted through in situ algal bioassay experiments (in situ ABEs) using the cubitainer setting in the reservoirs. For in situ ABEs, we compared and analyzed variations in chlorophyll-a (CHL-a) and phosphorus concentrations in Boryeong Reservoir before and after the water tunnel construction. We then analyzed the nutrient effects on the reservoir. Analysis for nitrogen and phosphorus was done in the three locations of the reservoir and two locations of the ABEs. The in situ ABEs results showed that phosphorous and Nitrogen, the primary limiting nutrient regulating the algal biomass was not limited in the system. The treatments of phosphorus or simultaneous treatments of N+P showed greater algal growth than in the control of nitrate-treatments, indicating a phosphorus deficiency on the phytoplankton growth in the system. The water from the Geum River had 5 times higher total phosphorus (TP) than the water in the reservoir. Efficient management is required as pumping of the river water from Geum River may accelerate the eutrophication of the reservoir.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1249-1251
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• 1998

We have studied the properties of $GaAs_{0.35}P_{0.65}$ epitaxial films on the GaP according to doping of $NH_3$ gas using VPE method by CVD. The efficiency of $GaAs_{0.35}P_{0.65}$ epitaxial films found to be greatly enhanced by the according of nitrogen doping. The diodes were fabricated by means of Zn diffusion into vapor grown $GaAs_{0.35}P_{0.65}$ epitaxial films doped with N and Te. The effects of nitrogen doping on carrier density of epitaxial films, PL wavelength and the power out, forward voltage of diodes are discussed. In the end, The effect of electrical and optical properties is influenced by the deep level and deep level density of nitrogen doping.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.383-390
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• 2008

Recently, the interests on economical nitrogen removal from wastewater are growing. As a method of the novel nitrogen removal technology, nitrogen removal via nitrite pathway by selective inhibition of free ammonia and free nitrous acid on nitrite oxidizing bacteria have been intensively studied. The inhibition effects of free ammonia and free nitrous acid are low when domestic wastewater is used, however, because of its relatively lower nitrogen concentration than the wastewater from industry and landfill, etc. In this study, a sequencing batch reactor (SBR) is proposed for nitrogen removal to investigate the effect of the low nitrogen concentration on nitrite accumulation. Nitrification efficiency reached almost 100% during the aerobic cycle and the maximum specific nitrification rate ($V_{max,nit}$) reached $17.8mg\;NH_4{^+}-N/g\;MLVSS{\bullet}h$. During the anoxic cycle, average denitrification efficiency reached 87% and the maximum specific denitrification rate ($V_{max,den}$) reached $9.8mg\;NO_3{^-}-N/g\;MLVSS{\bullet}h$. From the analysis the main reason of nitrite accumulation in the SBR was free nitrous acid rather than free ammonia. Nitrite accumulation increased with the decrease of organic content in the wastewater and the mechanism is not well understood yet. From the result of fluorescent in situ hybridization, the distribution of nitrite oxidizing bacteria was in equilibrium with ammonium oxidizing bacteria when nitrite accumulation did not occur.

• Journal of the Korean institute of surface engineering
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• v.34 no.3
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• pp.258-263
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• 2001

Siloxane thin films were fabricated on a silicon wafer by spin-coating using a siloxane solution made by the sol-gel process. Fluorine was doped using$ CF_4$ plasma treatment. The film was then annealed in-situ state in the nitrogen atmosphere. In order to examine the influence of annealing and fluorine doping on the siloxane thin film, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used and the dielectric constant was determined by the high-frequency capacitance-voltage method. Stable siloxane films could be obtained by in-situ annealing in a nitrogen atmosphere after $CF_4$ plasma treatment, and the dielectric value of the film was $\varepsilon$ 2.5.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.182.1-182
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• 1998

No Abstract, See Full Text

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.4
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• pp.395-401
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• 2013

In-situ optical emission spectroscopy (OES) is employed for leak detection in plasma etching system. A misprocessing is reported for significantly reduced silicon etch rate with chlorine gas, and OES is used as a supplementary sensor to analyze the gas phase species that reside in the process chamber. Potential cause of misprocessing reaches to chamber O-ring wear out, MFC leaks, and/or leak at gas delivery line, and experiments are performed to funnel down the potential of the cause. While monitoring the plasma chemistry of the process chamber using OES, the emission trace for nitrogen species is observed at the chlorine gas supply. No trace of nitrogen species is found in other than chlorine gas supply, and we found that the amount of chlorine gas is slightly fluctuating. We successfully found the root cause of the reported misprocessing which may jeopardize the quality of thin film processing. Based on a quantitative analysis of the amount of nitrogen observed in the chamber, we conclude that the source of the leak is the fitting of the chlorine mass flow controller with the amount of around 2-5 sccm.