Powdered metal parts and components may be carburized successfully in a vacuum furnace by combining carburizing technology VacCarb™ with a hi-tech control system. This approach is different from traditional carburizing methods, because vacuum carburizing is a non-equilibrium process. It is not possible to set the carbon potential as in a traditional carburizing atmosphere and control its composition in order to obtain a desired carburized case. This paper presents test results that demonstrate that vacuum carburizing system VacCarb™ carburized P.M. materials faster than traditional steel with acceptable results. In the experiments conducted, PM samples with the lowest density and open porosity showed a dramatic increase in the surface carbon content up to 2.5%C and a 3 times deeper case. Currently the boost-diffusion technique is applied to control the surface carbon content and distribution in the case. In the first boost step, the flow of the carburizing gas has to be sufficient to saturate the austenite, while avoiding soot deposition and formation of massive carbides. To accomplish this goal, the proper gas flow rate has to be calculated. In the case of P.M. parts, more carbon can be absorbed by the part’s surface because of the additional internal surface area created by pores present in the carburized case. This amount will depend on the density of the part, the densification grade of the surface layer and the stage of the surface – “as machined” or “as sintered”. It is believed that enhanced gas diffusion after initial evacuation of the P.M. parts leads to faster carburization from within the pores, especially when pores are open – surface “as sintered” and interconnected – low density. A serious problem with vacuum carburizing is delivery of the carbon in a uniform manner to the work pieces. This led to the development of the different methods of carburizing gas circulation such as the pulse/pump method or the pulse/pause technique applied in SECO/WARWICK’s VacCarb™ Technology. In both cases, each pressure change may deliver fresh carburizing atmosphere into the pores and leads to faster carburization from within the pores. Since today’s control of vacuum carburizing is based largely on empirical results, presented experiments may lead to better understanding and improved control of the process.
This study was carried out to comparison of the contents of general and mineral components between the original sample and water extract in each part of omija. The content of Carbohydrate was highest in endocarps, and that the crude protein and crude lipid in seeds. The contents of K and Mn in the fruits, endocarps, and seeds were all higher than those of the other cations. The content of K and Zn in endocarps were three to four times as much as those of seeds. and the content of Na, Ca, and Cu in endocarps were 1.5 to 1.75 times of seeds. Mineral contents by water extract in each part were ordered as K, Mg, Ca, and Fe. As the percentage of each ion in water extract on the basis of original sample, Fe was the highest ratio of behavior, and Mn was lowest.
Background : Recently, there have been dynamic researches conducted on stevia as natural sweetener subtitute for sugar, However, Researches related to harvest period and parts of plant in stevia are few. Therefore, this study was conducted to select optimum harvest time and parts by measuring the natural sweeteners contents and analyzing antioxidant materials and activity according to harvest times, parts of plant. Methods and Results : Stevia was cultivated in plastic house, The leaves were harvested from April to October and the stem were only harvest in July and September. Stevia leaves and stems were extracted using high temperature and pressure extraction: Dried stevia leaves of 5g were added by 100ml of distilled water equivalent to 20 times of dry weight, and the mixture were extracted by autoclave at 121℃ for 15min. The contents of Rebaudioside A and Stevioside of stevia leaves harvested from April to October showed a tendency to increase gradually from July to October as the temperature increased, but the contents of rebaudioside A and stevioside decreased slightly in August due to excessively high temperature. The extraction yield of stevia leaves were highest in October and September, and there was no significant difference in the other period. In the stevia stems, the extraction yield was lower than that of stevia leaves in general regardless of harvest time. Total phenolic contents and flavonoid contents according to harvest time showed little difference among treatment. Conclution : stevia leaves were better than stevia stems regarding the use of rebaudioside A and stevioside as natural sweeteners. Also, it was confirmed that the stevia leaves of July, September and October, except for the high temperature period of August, had superior in quality and quantity.
신안산 손바닥선인장의 수분함량은 열매 71.18%, 줄기 74.85%로 나타났고, 조단백질 함량은 줄기가 3.48%로 높았으며, 조섬유 또한 줄기가 2.58%로 열매 1.54%보다 높은 함량을 보였고, 조회분, 조지방은 열매와 줄기 모두 비슷한 함량을 보였다. 신안산 손바닥선인장의 유리당은 fructose, glucose, sucrose으로 구성되어 있었으며 maltose는 소량 검출되었고, 유기산은 tartaric acid, malic acid
본 연구는 뿌리를 저근백피라는 한방생약재로 사용하는 가죽나무(Ailanthus altissima)의 뿌리와 줄기 그리고 잎을 기능성 식품을 개발하기 위한 연구의 일환으로 영양정분과 생리활성 물질의 함유량을 측정하였다. 일반성분을 분석한 결과 뿌리에는 조회분(9.20%)과 조단백질(7.86%)이 많았으며, 잎에는 조단백질(11.36%) 그리고 줄기에서는 탄수화물(81.74%)의 함유량이 비교적 높았다. 수용성 단백질은 잎에서 9,839.52 mg%
작약의 이용성을 높이기 위해 작약의 종 및 품종, 생육시기, 식물체 부위별 성분의 함량 분포와 변화를 HPLC를 이 용하여 분석한 결과를 요약하면 다음과 같다. 작약의 종 및 품종간 성분의 함량 분포는 야생작약(P. japonica M., P. obovata M., P. anomala L.) 보다는 재배작약(태백작약, 의성작약)에서 전반적으로 함량이 더 높았고, 성분별 분포는 paeonifloin, methyl gallate, astragalin, kaempferol 순으로 높았으며 methyl gallate 는 의성작약에서 0.45%로 가장 높았다. 식물체 부위별 함량 분포는 methyl gallate는 꽃잎에서 1.79%로 가장 높았으며 잎에는 0.56% 함유하였고, 뿌리에는 0.01%로서 소량 분포하였다. Astragalin 은 꽃잎과 잎에서 높았고, 작약의 지표 성분인 paeoniflorin 은 뿌리에서 2.52%로 가장 높았으며 잎에도 1.09%나 함유하여 이용 가치가 매우 높다고 사료된다. 생육시기별 함량 분포는 생육초기인 4월에 가장 높았고 생육 후기로 갈수록 감소하는 경향이므로 잎과 줄기를 이용하려면 뿌리 수확직전인 8~9 월이 적기라고 생각된다.
한국산 작두콩을 부위별(종자, 자엽, 껍질, 깍지, 잎, 줄기 및 뿌리)로 구분하여 화학성분을 분석한 결과는 다음과 같다. 작두콩의 부위별 일반성분 중 총당과 조단백질은 다른 부위에 비해 자엽에서 높게 나타났으며, 무기성분은 뿌리에서 칼륨, 잎에서는 칼슘의 함량이 높게 나타났으며, 유기산은 잎의 경우 oxalic acid가 2.556 mg%, 깍지는 citric acid가 573 mg%로 가장 높았다. 유리당은 껍질에서 sucrose가 3.80%
To furnish basic data about the utilization of Korean loquat as flood, this experiment was conducted. Nutritional components in leaves, fruit excluded seed, flesh and seed of Korean loquat were analyzed as follows : moisture 48.7%, 87.8%, 88.3% and 59.5% ; total sugar 1.57%, 7.21%, 7.36% and 2.41% ; crude protein 5.23%, 1.61%, 1.44% and 4.31% in each portion, respectively. The highest mineral contents of loquat leaves, fruit excluded seed, flesh and seed were Ca 2,458ppm, K 661ppm, 654ppm and 1,528ppm, and water soluble vitamins such as ascorbic acid, thiamin and pyridoxine were confirmed in different pares of Korean loquat, the contents of those were high thiamin 5.86mg% in leaves and ascorbic acid 1.l0mg%, 1.26mg% and 4.90mg% in fruit excluded seed flesh and seed, respectively. The contents of free sugars were high sucrose 0.87%, glucose 0.62%, 0.6475 and rhamnose 0.20%, and major organic acid were detected oxalic acid 1,693.70mg%, malic acid 201.70mg%, 207.60mg% and citric acid 55.70mg% in each portion, respectively. Free amino acid were identified 21, 14, 14 and 16 kinds of leaves, fruit excluded seed, flesh and seed, respectively and their contents in each portion were highest glutamic acid 280.22mg%, proline 35.l0mg%, glutamic acid 56.96mg% and sarcosine 230.24mg%, respectively. Volatile components were identified 25 and 11 kinds of leaves and flesh and their contents were highest d-nerolidol 28.70ppm, hexadecanoic acid 16.67ppm, respectively.