• Geomechanics and Engineering
• /
• 제24권4호
• /
• pp.337-348
• /
• 2021

Brillouin Optical Frequency Domain Analysis (BOFDA) is a distributed fiber optic sensing (DFOS) technique that has unique advantages for performance monitoring of piles. However, the complicated production process and harsh operating environment of offshore PHC pipe piles make it difficult to apply this method to pile load testing. In this study, sensing cables were successfully pre-installed into an offshore PHC pipe pile directly for the first time and the BOFDA technique was used for in-situ monitoring of the pile under axial load. High-resolution strain and internal force distributions along the pile were obtained by the BOFDA sensing system. A finite element analysis incorporating the Degradation and Hardening Hyperbolic Model (DHHM) was carried out to evaluate and predict the performance of the pile, which provides an improved insight into the offshore pile-soil interaction mechanism.

• Asian-Australasian Journal of Animal Sciences
• /
• 제11권6호
• /
• pp.673-679
• /
• 1998

The experiment was conducted to determine in situ rumen degradability of soybean meal (SM), fish meal (FM), sesame cake (SC) and Italian ryegrass hay (IRGH) and the effect of supplementing the above protein meals to IRGH on digestibility and balance of nutrients in three Saanen goats. For measuring the degradability, nylon bags containing each meal were incubated in the rumen of one fistulated dry cow for 3, 6, 12, 24, 36, and 48 hrs. Degradability revealed that SM protein was highly degradable in the rumen (99.1%), while FM protein was less degradable (76.8%) with SC protein being intermediate (91.2%) at 48 hrs of incubation (p < 0.01). Degradation rate of the potentially degradable fraction was estimated to be 12.12, 5.88 and 5.88%/hr for SM, FM and SC, respectively. In the metabolism trial, all goats were offered daily 900 g IRGH and one of the supplements, SM (100 g), FM (75 g) or SC (100 g). Intake of DM, OM, CP and GE was similar among diets. However, digestibility of OM for SC diet was significantly lower than that for diets supplemented with FM and SM (p < 0.10). Nitrogen (N) excreted in faeces (p < 0.05) and in urine (p < 0.10) was, respectively, higher and lower for SC diet than that for the other two diets. The same tendency was observed in energy losses in faeces (p < 0.10) and in urine (p < 0.05). There was no difference in energy loss in methane or in heat production among diets. Consequently, no significant difference was observed in N retention (2.13, 0.42 and -0.11 g/day for FM, SC and SM diet, respectively) or in energy retention (-1.49, -2.14 and -2.70 MJ/day for FM, SM and SC diet, respectively). These results showed that protein supplements affected the digestion of diets based on grass hay with 7.45% CP in DM in goats, although there was no significant influence on N or energy retention.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권6호
• /
• pp.802-806
• /
• 2005

The objective of this study was to determine the effects of processing method and rapeseed variety on ruminal and intestinal protein digestibility of rapeseed meal in steers. Intestinal amino acid digestibility was assessed with an in situ ruminal incubation and precision-fed rooster bioassay. In this experiment one traditional rapeseed meal sample (sample A, prepress extraction) and three double low rapeseed meal samples (sample B, prepress extraction, sample C, screw press and sample D, low temperature press) were placed in polyester bags(8 cm${\times}$12 cm) and suspended in the ventral rumen of steers for 16 h. The residues of in situ incubations were intubated to roosters. Total excreta were collected for 48 h after incubation and then desiccated and amino acid concentrations were determined. Results showed that in ruminal incubation the degradation rate of amino acid and crude protein was higher for traditional rapeseed meal sample A than for double low rapeseed meal sample B, but was much lower than for double low sample C and D. In the group of double low rapeseed meal samples, sample D processed by low temperature press had the highest degradation rate of amino acids in the rumen. For all amino acids, the digestibility of the residual protein as measured by the precision-fed rooster bioassay tended to be lower for sample B than for sample A, which had the same processing method with sample B, and in the group of double low rapeseed meals, sample B had similar digestibility of amino acid in residual protein to sample D and higher than that of sample C. However, although the total amino acid availability involving the digestibility of amino acids in the rumen and rooster bioassay of double low rapeseed meal sample D (low temperature press) was higher than those of the other three samples by 7 to 9 percent, there were no significant differences. Results indicated that processing method markedly affected ruminal and post ruminal amino acid digestibility of rapeseed meal when the temperature exceeded 110$^{\circ}C$. Rapeseed meal that had a high content of fiber was not suitable for dry heat treatment at higher temperatures or the amino acids digestibility in rumen and total availability of amino acids could be reduced. Results also suggested the variety of rapeseed meal had no significant effect on the digestibility and availability of amino acids.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
• /
• pp.79-83
• /
• 2001

In order to compare the barrier properties of Ta-N/Si(001) with those of Ta-N/Ta/Si(001), we studied structural properties of films grown by RF magnetron sputtering with various $Ar/N_2$ ratios. To evaluate the barrier properties, the samples were annealed in a vacuum chamber. Ex-situ x-ray scattering measurements were done using an in-house x-ray system. With increasing nitrogen ratio in Ta-N/Si(001), the barrier property of Ta-N/Si(001) was enhanced, finally failed at $750^{\circ}C$ due to the crystallization and silicide formation. Compared with Ta-N/Si(001), Ta-N/Ta/Si(001) forms silicides at $650^{\circ}C$. However it does not crystallize even at $750^{\circ}C$. With increasing nitrogen composition in Ta-N/Ta/Si(001), the formation of tantalum silicide was reduced and the surface roughness was improved. To observe the surface morphology of Ta-N/Ta/Si(001) during annealing, we performed an in-situ x-ray scattering experiment using synchrotron radiation of the 5C2 at Pohang Light Source(PLS). Addition of Ta layer between Ta-N and Si(001) improved the surface morphology and reduced the surface degradation at high temperatures. In addition, increasing $N_2/Ar$ flow ratio reduced the formation of tantalum silicide and enhanced the barrier properties.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권5호
• /
• pp.633-637
• /
• 2004

The experiment of silage for preservation of fresh Italian ryegrass (Lolium multiflorum) was carried out to examine whether the fermentation quality and microbial degradation in the rumen can be altered by the treatment of amino acids fermentation byproduct (AFB). The plant was ensiled for 40 days with 4 treatments of different ratios of AFB and sugarcane molasses (SCM) mixture. The treatment 2 (T2, AFB:SCM=100:0) and treatment 3 (T3, AFB:SCM=40:60) silages showed higher (p<0.05) concentrations of lactic acids, lower (p<0.05) pH and dry matter (DM) losses than the Control (T1, none additive) and treatment (T4, AFB:SCM=0:100) silages. The treatments 2 and 3 contained higher (p<0.05) DM and crude protein contents in silages compared to treatments 1 and 4 silages. The NDF, ADF and cellulose contents were also lower (p<0.05) in T2, T3 and T4 silages than T1 silage and fresh material before ensiled. The in situ rumen DM, NDF, ADF, hemicellulose and cellulose degradability was also higher (p<0.05) in T2, T3 and T4 silages than T1 silage, while the highest improvement was achieved with addition of AFB:SCM at level of 40:60 at ensiling. The result in this study indicates that the addition of AFB and SCM additives improved the silage fermentation and cell wall degradability of Italian ryegrass silage.

• 한국강구조학회 논문집
• /
• 제16권4호통권71호
• /
• pp.415-423
• /
• 2004

옥외 강구조물의 중요 소재인 무도장 내후성강의 장기 내식성을 평가하기 위해 우선 9년 이상 산업대기와 전원대기에 폭로된 본 강판 및 비교재 일반강판 시편의 천향면에 대해 중성의 인공우수에 침적시켜 전기화학적 부식전위, 임피던스 및 동전위 양분극 곡선으로 측정 및 그 결과를 고찰하였다. 산업대기 및 전원대기에 천향면으로 폭로된 내후성강 표면에는 부동태적인 안정화 녹층이 발달하였으며, 산업대기 폭로 표면의 인공우수에서의 부식속도는 $3{{\mu}m}/y$로 측정되어 우수한 내후내식 녹층으로 덮혀 있었다. 지속적으로 인공우수에 침적시키면 모든 시편 녹층은 점진적으로 열화되어 모재 철분의 양극산화용해 율속의 부식으로 진전됨을 나타내었다. 내후성 합금성분은 이런 부식의 진전을 지연시키고 있었다. 장기 내식성을 잘 평가하기 위해서는 9년보다 훨씬 장기간 대기폭로된 강재표면과 해당 대기 응축수 모사 수용액을 이용한 전기화학적 측정이 필요하다. 특히 본 측정방법들은 강재 표면의 원하는 부위와 폭로시간대에 거의 비파괴적으로 부식상황과 녹층의 상태와 정량적인 부식속도를 직접 바로 측정할 수 있게 하므로 강재를 사용한 교량, 탑, 건축물 등의 강구조물의 표면에 전기화학적 cell을 구성하고 이동측정기를 사용하면 강구조물의 내후 내식성을 현장즉시 측정 및 평가를 효과적으로 가능하게 할 수 있다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제28권1호
• /
• pp.15-24
• /
• 2023

A persulfate(PS)/sulfidated microscale zero-valent iron(S-mZVI) system was tested for treating a soil contaminated with phenol. Sulfidation of bare mZVI was conducted using a mechanochemical process utilizing a ball mill in order to improve persulfate activation capacity and stability of unmodified mZVI. The synthesized S-mZVI performed markedly better than the bare mZVI in activating PS. The optimum molar ratio of sulfur to mZVI was around 0.12. In the soil slurry experiments, a very rapid and complete removal of phenol was observed at the optimum molar ratios of PS to S-mZVI of 2:1 and PS to phenol of 16:1. The phenol removal efficiencies decreased as the water content of the slurries decreased. This was believed to be due to increased soil oxidant demand as the amount of soil was increased as relative to the water content. To evaluate the field applicability of the process, slurry experiments adopting high soil contents were carried out that simulated in-situ soil mixing conditions. These experiments resulted in substantially compromised degradation efficiencies of 54.3% and 43.8% within 4 hours. The current study generally shows that the PS/S-mZVI process has a potential to be developed into a remediation technology for soils contaminated with organics.

• 농업과학연구
• /
• 제39권3호
• /
• pp.407-412
• /
• 2012

Soil texture has an important influence on agriculture such as crop selection, movement of nutrient and water, soil electrical conductivity, and crop growth. Conventionally, soil texture has been determined in the laboratory using pipette and hydrometer methods requiring significant amount of time, labor, and cost. Recently, in-situ soil texture classification systems using optical diffuse reflectometry or mechanical resistance have been reported, especially for precision agriculture that needs more data than conventional agriculture. This paper is a part of overall research to develop an in-situ soil texture classification system using image processing. Issues investigated in this study were effects of sensor travel speed and light source and intensity on image quality. When travel speed of image sensor increased from 0 to 10 mm/s, travel distance and number of pixel were increased to 3.30 mm and 9.4, respectively. This travel distances were not negligible even at a speed of 2 mm/s (i.e., 0.66 mm and 1.4), and image degradation was significant. Tests for effects of illumination intensity showed that 7 to 11 Lux seemed a good condition minimizing shade and reflection. When soil water content increased, illumination intensity should be greater to compensate decrease in brightness. Results of the paper would be useful for construction, test, and application of the sensor.

• 한국환경농학회지
• /
• 제29권4호
• /
• pp.388-395
• /
• 2010

미생물을 이용한 인삼 재배지 내 잔류 tolclofos-methyl의 효과적 분해를 목적으로, tolclofos-methyl에 대한 분해능을 보이는 미생물을 선발하였다. 선발된 미생물은 16S rDNA 염기서열분석을 통하여 Sphingomonas 속으로 동정되었다. 선발 미생물 Sphingomonas sp. 224는 1/10 농도의 LB 배지에 함유된 20 mg/L 농도의 tolclofos-methyl을 배양 72시간 이내에 95% 이상 분해하는 것으로 확인되었다. 또한 이 미생물이 tolclofos-methyl을 분해하여 얻어지는 산물로 2,6-dichloro-4-methyl phenol이 확인됨에 따라 미생물이 생산하는 가수분해 효소에 의한 분해 경로를 가지는 것으로 추정되었다. Tolclofos-methyl 분해 미생물 Sphingomonas sp. 224를 인삼경작지 토양에 처리하여 이들 토양에 잔류되어 있는 tolclofos-methyl에 대한 분해능을 확인 한 결과, 20 mg/Kg 농도의 토양 잔류 tolclofos-methyl에 대하여 14일 이내에 약 50%의 분해력을 보이는 것으로 확인되었다. 이것은 단일 미생물을 이용한 배지 및 토양 내 tolclofosmethyl의 생분해 효과를 처음으로 확인한 연구 결과이다.

• 한국재료학회지
• /
• 제3권2호
• /
• pp.151-157
• /
• 1993

In situ on-axis rf magnetron sputtering 방법으로 $Y_1$B$a_2$C${u_4}\;{_2O_x}$의 비화학 양론적인 타게트를 사용하여 $T_c$, $_{zero}$/-88.2K, ${\Delta}{T_c}$, <1.5K의 고온초전도 박막을 제조하고, 활성이온식각법으로 이 박막을 patterning하여 그 특성을 조사하였다. 제조된 패턴은 깨끗한 경계면을 가지고 있음이 관찰되었으며, 패턴 폭이 5${\mu}$m에서 2${\mu}$m로 좁아짐에 따라 임계온도와 임계전류밀도의 특성저하가 나타났으나, 그 저하폭이 크지 않아 소자로서 응용하기에 충분한 특성을 가지고 있음을 확인하였다. 한편 RIE방법에 의하여 미크론 이하의 선폭 제조가능성을 확인하였다.