본 실험은 Dendrobium nobile 계통의 교잡종인 'Hamana Lake Dream' X 'No. 55' 유묘의 기내삽목 시 증 식 및 생육에 알맞은 배지와 배양조건을 구명하고자 실시하였다. Hyponex배지보다 MS배지에서 생장이 잘되었는데 MS배지에 활성탄을 0.1과 1.0g/L 수준에서 첨가했을 때 줄기수와 엽장, 근수, 생체중이 양호 하였으나 2.0g/L이상에서는 감소하였으나 통계적 유의성은 없었다. MS배지에 agar, sucrose, peptone, gelite 를 농도별로 첨가한 실험에서는 agar 5g/L 첨가 시 줄기 길이와 엽폭, 생체중의 값이 높았고, 절간장과 근수는 sucrose 40g/L을 첨가했을 때 효과적이었다. 또한 줄기수와 엽수는 peptone 1g/L에서 효과적이었으 나 gelite는 모든 농도에서 대조구에 비해 저조하였다. 기내삽목 시 배양온도는 28℃가 알맞았고 동일한 온도조건에서는 MS배지가 Hyponex배지보다 더 효과적이었다. 또한 sucrose 농도별 실험에서는 28℃에서 40 g/L를 첨가하는 것이 좋았다.

In 450mm wafers production environment for next generation Fab, one of the most significant features is the adoption of full automation to the whole manufacturing processes involved. The full automation system will prevent the workers from intervening the manufacturing processes as much as possible and increase the importance of each individual wafer noticeably, and thus require a more robust scheduling system for entire semiconductor manufacturing processes. The scheduling system for 450mm wafers production also should be capable of monitoring the status of each individual wafer and collecting useful Fab data in real time. In this study, we first analysis of cluster tool in 450mm wafers production environment, and then propose a real-time scheduling algorithm based on timetabling algorithm.

Recently, one-dimensional semiconducting nanomaterials have attracted considerable interest for their potential as building blocks for fabricating various nanodevices. Among these semiconducting nanomaterials,, SnO2 nanostructures including nanowires, nanorods, nanobelts, and nanotubes were successfully synthesized and their electrochemical properties were evaluated. Although SnO2 nanowires and nanobelts exhibit fascinating gas sensing characteristics, there are still significant difficulties in using them for device applications. The crucial problem is the alignment of the nanowires. Each nanowire should be attached on each die using arduous e-beam or photolithography, which is quite an undesirable process in terms of mass production in the current semiconductor industry. In this study, a simple process for making sensitive SnO2 nanowire-based gas sensors by using a standard semiconducting fabrication process was studied. The nanowires were aligned in-situ during nanowire synthesis by thermal CVD process and a nanowire network structure between the electrodes was obtained. The SnO2 nanowire network was floated upon the Si substrate by separating an Au catalyst between the electrodes. As the electric current is transported along the networks of the nanowires, not along the surface layer on the substrate, the gas sensitivities could be maximized in this networked and floated structure. By varying the nanowire density and the distance between the electrodes, several types of nanowire network were fabricated. The NO2 gas sensitivity was 30~200 when the NO2 concentration was 5~20ppm. The response time was ca. 30~110 sec.

We investigated the NO gas sensing characteristics of ZnO-carbon nanotube (ZnO-CNT) layered composites fabricated by coaxial coating of single-walled CNTs with a thin layer of 1 wt% Al-doped ZnO using rf magnetron sputtering deposition. Morphological studies clearly revealed that the ZnO appeared to form beadshaped crystalline nanoparticles with an average diameter as small as 30 nm, attaching to the surface of the nanotubes. It was found that the NO gas sensing properties of the ZnO-CNT layered composites were dramatically improved over Al-doped ZnO thin films. It is reasoned from these observations that an increase in the surface-to-volume ratio associated with the numerous ZnO “nanobeads” on the surface of the CNTs results in the enhancement of the NO gas sensing properties. The ZnO-CNT layered composite sensors exhibited a maximum sensitivity of 13.7 to 2 ppm NO gas at a temperature of 200˚C and a low NO gas detection limit of 0.2 ppm in dry air.

We investigated the effects of Co doping on the NO gas sensing characteristics of ZnO-carbon nanotube (ZnO-CNT) layered composites fabricated by coaxial coating of single-walled CNTs with ZnO using pulsed laser deposition. Structural examinations clearly confirmed a distinct nanostructure of the CNTs coated with ZnO nanoparticles of an average diameter as small as 10 nm and showed little influence of doping 1 at.% Co into ZnO on the morphology of the ZnO-CNT composites. It was found from the gas sensing measurements that 1 at.% Co doping into ZnO gave rise to a significant improvement in the response of the ZnO-CNT composite sensor to NO gas exposure. In particular, the Co-doped ZnO-CNT composite sensor shows a highly sensitive and fast response to NO gas at relatively low temperatures and even at low NO concentrations. The observed significant improvement of the NO gas sensing properties is attributed to an increase in the specific surface area and the role as a catalyst of the doped Co elements. These results suggest that Co-doped ZnOCNT composites are suitable for use as practical high-performance NO gas sensors.

본 연구는 옥수수 재배지에서 경운방법과 가축분뇨의 시용이 사료용 옥수수의 생산성 및 질소의 용탈에 미치는 영향을 알아보기 위하여 국립축산과학원 초지사료과 시험포장(천안)에서 lysimeter를 이용하여 2008년 4월부터 8월까지 실시하였다. 시험구 배치는 분할구배치법으로 경운방법(경운과 무경운)을 주구로 하였으며, 가축분뇨의 종류(화학비료, 우분퇴비 및 돈분퇴비)를 세구로 하였다. 가축분뇨의 시용은 화학비료구는 표준시용량(N-)으로 200, 150 및

A field experiment was conducted to develop a no-herbicide cropping system of high protein forage. The first crop of winter ㏊bit Italian ryegrass sown in early-April produced DM yield of 4.5t/㏊ (crude protein content: 13.5%) in mid-June and the succeeding crop of soybean no-till planted into ryegrass produced DM yield of 5.1t/㏊ (crude protein content: 19.7%) in Late-October. In this cropping system, the ryegrass remained in vegetative phase during all cropping season and formed dense sod. This sod functioned as living mulch and suppressed weeds without herbicide application both during ryegrass and soybean cropping. Though the soybean germinated under the canopy of regrowing ryegrass sod, its growth was scarcely depressed by the canopy s㏊de because the seedling of soybean appeared above the canopy of sod in a few days. Contrariwise, the ryegrass was gradually shaded by the soybean and ㏊d died before October harvest. The degree of weed suppression by the ryegrass living mulch varied with seeding rate of ryegrass or weed pressure in the field. The optimum seeding rate to suppress weed was 50㎏/㏊ in the field with low or medium weed pressure and was 80 ㎏/㏊ in the field with high weed pressure.

Nitric oxide (NO) acts as an intracellular messenger at the physiological level but can be cytotoxic at high concentrations. The cells within periodontal tissues, such as gingival and periodontal fibroblasts, contain nitric oxide syntheses and produce high concentrations of NO when exposed to bacterial lipopolysaccharides and cytokines. However, the cellular mechanisms underlying NO-induced cytotoxicity in periodontal tissues are unclear at present. In our current study, we examined the NO-induced cytotoxic mechanisms in human gingival fibroblasts (HGF). Cell viability and the levels of reactive oxygen species (ROS) were determined using a MTT assay and a fluorescent spectrometer, respectively. The morphological changes in the cells were examined by Diff-Quick staining. Expression of the Bcl-2 family and Fas was determined by RT-PCR or western blotting. The activity of caspase-3, -8 and -9 was assessed using a spectrophotometer. Sodium nitroprusside (SNP), a NO donor, decreased the cell viability of the HGF cells in a dose- and time-dependent manner. SNP enhanced the production of ROS, which was ameliorated by NAC, a free radical scavenger. ODQ, a soluble guanylate cyclase inhibitor, did not block the SNP-induced decrease in cell viability. SNP also caused apoptotic morphological changes, including cell shrinkage, chromatin condensation, and DNA fragmentation. The expression of Bax, a member of the proapoptotic Bcl-2 family, was upregulated in the SNP-treated HGF cells, whereas the expression of Bcl-2, a member of the anti-apoptotic Bcl-2 family, was downregulated. SNP augmented the release of cytochrome c from the mitochondria into the cytosol and enhanced the activity of caspase-8, -9, and -3. SNP also upregulated Fas, a component of the death receptor assembly. These results suggest that NO induces apoptosis in human gingival fibroblast via ROS and the Bcl-2 family through both mitochondrial- and death receptor-mediated pathways. Our data also indicate that the cyclic GMP pathway is not involved in NO-induced apoptosis.

본 연구는 딸기 배양액의 NO3-N와 NH4-N의 비율을 달리하여 '장희(章姬)' 딸기의 생육, 수량 및 과실의 품질, 그리고 양이온 흡수에 미치는 영향을 알아보고자 수행하였다. NO3-N와 NH4-N의 비율은 5.5:0, 4.0:1.5, 3.0:2.5me·L-1로 조절하였다. 실험기간 동안 배양액내의 NH4-N의 비율이 높아질수록 pH가 낮았으며, EC는 전 실험기간 동안 0.8~1.0dS·m-1로 4월 이후에 5.5:0 처리구가 다른 처리구보다 약간 낮았으나 그 외에는 처리구 간에 유의한 차이를 나타내지 않았다. NO3-N:NH4-N를 3.0:2.5로 NH4-N의 비율을 높여도 양이온의 흡수에 길항증상이 나타나지 않았다. 딸기의 엽병장과 엽폭은 NO3-N의 단독 처리구 보다 NO3-N:NH4-N이 4.0:1.5와 3.0:2.5인 처리구에서 더 길어졌다. NO3-N:NH4-N이 4.0:1.5와 3.0:2.5 처리구 간에는 유의한 차이가 없었다. 과장, 과경, 과중, 당도는 NO3-N와 NH4-N비율 차이에 따른 통계적인 유의차가 인정되지 않았다. 주당 과실 수량은 NO3-N:NH4-N 4.0:1.5의 처리구에서 가장 낮았으며, 나머지 두 처리간에는 유의한 차이가 없었다. 실험 기간 동안 이상과는 전혀 발생하지 않았다.

The NO gas sensing properties of ZnO-carbon nanotube (ZnO-CNT) composites fabricated by the coaxial coating of single-walled CNTs with ZnO were investigated using pulsed laser deposition. Upon examination, the morphology and crystallinity of the ZnO-CNT composites showed that CNTs were uniformly coated with polycrystalline ZnO with a grain size as small as 5-10 nm. Gas sensing measurements clearly indicated a remarkable enhancement of the sensitivity of ZnO-CNT composites for NO gas compared to that of ZnO films while maintaining the strong sensing stability of the composites, properties that CNT-based sensing materials do not have. The enhanced gas sensing properties of the ZnO-CNT composites are attributed to an increase in the surface adsorption area of the ZnO layer via the coating by CNTs of a high surface-to-volume ratio structure. These results suggest that the ZnO-CNT composite is a promising template for novel solid-state semiconducting gas sensors.