This paper has been carried out the forming analysis, die stress analysis, and relevant tests for the straightness improvement of hollow shafts with blocktooth. Hollow forward extrusion is a process that a material in a die is pressed with a punch and the material is formed into the same direction through the gap of a mandrel and a bottom die. For an asymmetric shaped product, due to the difference of reduction ratios of the cross sections in its extruding, a phenomenon that the product bends from the difference of the flow speed comes to occur. As applying the key to the mandrel has a uniform flow speed, bending problem was solved. These were processed using Deform-3D as a finite-element analysis program. Analysis was compared with the experiment. Keyway height of the mandrel has been confirmed that the straightness best when it comes 0.1mm. These study are expected to be available as fundamental data in die design necessary for the manufacture of asymmetric goods in the future.

본 연구는 산국 생균제가 비육후기 거세한우의 성장율과 육질에 미치는 효과를 조사하기 실시하였다. 거세한우 15두(565±17kg)를 시험구별 개시체중이 유사하도록 산국 생균제 무첨가구(CON), 농후사료의 0.2% 첨가구(LCB) 및 0.4% 첨가구(HCB)에 각 5두씩을 배치하고 150일간 사양시험을 실시하였다. 농후사료와 조사료를 8:2의 비율로 설정하고 생체중의 약 2.5%를 오전(8시)과 오후(5시)로 나누어 급여하였다. 미네랄 블록과 음수는 자유로이 섭취할 수 있도록 하였다. 사양시험 종료 후에는 모든 공시동물은 도축하여 도체특성을 조사하고 등심육을 채취하여 육질분석에 이용하였다. 개시체중과 종료체중은 처리구간 차이가 없었으나, 일당증체량, 사료섭취량 및 사료효율은 산국 생균제를 급여한 모든 시험구에서 대조구에 비해 개선되었다(p<0.05). 분 중 황화수소와 암모니아 가스는 시험구간 차이가 없었다. 신선육 관능평가에서 등심육의 육색은 산국 생균제를 급여한 시험구가 개선되었으나(p<0.05), 등심육의 물리화학적 특성과 기타 신선육 관능평가는 시험구간 차이가 없었다. 등심육의 지방산 조성은 산국 생균제를 급여한 시험구에서 C14:0과 C18:0 함량이 증가하였으며(p<0.05), HCB 시험구에서 C18:2n-6와 polyunsaturated fatty acid 함량은 HCB 시험구에서 가장 높게 나타났다(p<0.05). 따라서 비육후기 거세한우에 산국 생균제를 0.4% 수준으로 급여하는 것은 사료효율 개선, 육색 및 등심육 지방산 품질개선에 유리할 것으로 사료된다.

The objective of this study was to know the in vitro effects of supplemental anthelmintic plant extracts on the inhibition of protozoa for reducing methane production in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The plant extracts (Lonicera japonica, Zanthoxylum piperitum, Pyrethrum, Torreya nucifera, Ruta graveolens) known to have anthelmintic effect were added to the in vitro fermentation bottles containing the rumen fluid and medium. The rumen protozoal population was depressed by the addition of Pyrethrum, Torreya nucifera and Ruta graveolens. The methane production was also significantly (p<0.05)reduced by addition of Pyrethrum (2.20 ml/g DM), Torreya nucifera (2.36 ml/g DM) and Ruta graveolens (2.20 ml/g DM). The microbial growth in the treatments of Ruta graveolens or anthoxylum piperitum was the greatest after 12 h and 24 h incubations, respectively. The results of this study indicated that anthelmintic plant extracts appeared to reduce methane production by inhibition of ruminal protozoa related with the methanogens living endosymbiotic in protozoal cells.

본 연구는 미생물 첨가가 느타리버섯 폐배지의 영양소 함량, 발효특성 및 미생물상에 미치는 영향을 조사하기 위해 수행하였다. 시험은 느타리버섯 폐배지에 미생물 무첨가구(CON), 고초균 첨가구 (Bacillus subtilis 2⨯1010 cfu/g; BS), 유산균 첨가구(Lactobacillus plantarum 2⨯1010 cfu/g; LP) 및 혼합균 첨가구(Bacillus subtilis : Lactobacillus plantarum = 1:1; BL)로 4 시험구를 설정하고 6일간 발효시켰다. 발효 직후 0, 1, 2, 4 및 6일에 시료를 채취하여 분석에 이용하였다. 발효 6일후 조단백질과 조지방 함량은 BS구에서 가장 높았다(P<0.05). NDF 함량은 LP구와 BL구에서, ADF 함량은 미생물을 첨가한 모든 시험구에서 높은(P<0.05) 반면, in vitro 건물소화율은 CON구가 높았다 (P<0.05). Lactate와 propionate 함량은 CON구와 BS구가 타 시험구에 비해 높았다(P<0.05). 한편 발효 0일에 유산균 함량은 BS구와 LP구에서 높았으며(P<0.05), 발효 1일에 유산균 함량은 LP구에서, 고초균 함량은 BL구에서 각각 높았다(P<0.05). 발효 2일에 lactate와 propionate 함량은 LP구와 BL구에서 타 시험구에 비해 높았다(P<0.05). 이상에서와 같이 BS 첨가는 발효과정 중 유기산 생성량 개선에는 유리하나 건물소화율에는 부정적인 영향을 미칠 것으로 사료된다.

Withthe increasing trend of global trades and protection of agro-ecosystem in importing and exporting countries against quarantine pest, quarantine and pre-shipment(QPS) fumigation in perishable commodities is now more important to maintain postharvest quality until delivering to end user not just eradiation of quarantine pest. However, there are limited use of MB fumigation on export fruits and vegetables due to phytotoxic damages of fumigated one. VapormateTM, alternative to methyl bromide(MB), a gas formulation of ethyl formate(EF) with carbon dioxide, is commercially in use for imported fruits fumigation such as bananas and lemon. Herein, based on previous preliminary studies, scale-up and commercial scale fumigation of ethyl formate is presented for promising export paprika and tomato. Efficacy of ethyl formate was described in terms of concentration × time (CT) products to Myzus persicae for paprika and Bemisia tabaci for tomato.

Since Montreal protocol in1989 designated MB(methyl bromide) as ozone depleting chemicals, IPPC(International Plant Protection Convention) has adopted replacing the MB with alternative chemical and reducing the rate of MB use in plant quarantine in 2008. Pineapples are one of the most frequently fumigated imported fruit with MB in Korea. However, there was no technically available replacement. Therefore, we evaluated phosphine(PH3) fumigation as alternative to MB in applying pineapples. In the preliminary test, PH3 gas in 12L desicators to calculate ranged to 0.1 from 2g/m3 was tested at 2 and 24hr exposure to target pest, citrus mealy bug(CMB, Planococcus citri). All different of stage of CMB was shown 100% mortality when 2g/m3 of PH3 applied for 24hrs at 8℃. To confirm studies designed in 0.5m3 fumigation chamber, all egg, nymph and adult stages of CMB was killed completely and there wasn’t any phytotoxic and quality damages on pineapples for 2 weeks post-fumigation periods at 8℃. In terms of commercial use, further commercial research will need to be carry out in cooperation with importers and fumigators.

Beef marbling is known as one of the most important beef-quality traits in Korea. It is likely that marbling derived from fatty acids, mainly propionate, is mediated by rumen. Recently micro-agents were studied to enhance marbling, although many parts of that were digested in rumen. Therefore, this study was conducted to screen candidate materials to effect on beef quality with in vitro ruminal incubation. The materials such as saponin, chitosan, Zn compounds (4), vitamin C sources (2), Korean herb cocktail and garlic sources (2) were added to rumen fluid to 1.25% of substrate volume at 0 and 24 h incubation time. Total gas production in intact vitamin C source increased but that in all Zn compounds decreased (P＜0.05). Total gas production in Zn sulfate compound less decreased than in other Zn sources. Propionate in Zn sulfate increased than the other candidate compounds at all incubation time (P＜0.05). Experiment two was conducted to clarified effect of additives such as vitamin C sources (2), garlic lyophilized, Korea herb cocktail and Zn sulfate were supplemented with 2.5% volume at the 0, 3, 6, 12 and 24 h incubation time. Total gas in Zn sulfate was lower than any other treatments. Propionate in garlic, herb and Zn sulfate appeared to be lower than control and vitamin C sources at all incubation time, although significant difference was not observed in total VFA among control and all treatment. This study suggested that micro-agent might be used to improve beef quality with minute level.