• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.5
• /
• pp.415-422
• /
• 2015

Ballscrews are important motion transfer and positioning units of industrial machinery and precision machines. Positioning accuracy of the feed drive system depends upon axial stiffness of ballscrew systems. As the nut stiffness depends upon preload and operating conditions, analytical modeling of the stiffness is performed through the contact and body deformation analysis. For accurate contact analysis, the contact angle variation between balls and grooves is incorporated in the developed model. To verify the developed mathematical stiffness model, experiments are conducted on the test-rig. Through the uncertainty analysis according to GUM (Guide to the expression of Uncertainty in Measurement), it is confirmed that the formulated stiffness model has over 85% estimation accuracy. After constructing the ballscrew DB, a quick turnaround system for the nut stiffness estimation has been developed in this research.

• The Plant Pathology Journal
• /
• v.32 no.3
• /
• pp.209-215
• /
• 2016

In this study, the treatment of pistachio nuts by Bacillus subtilis UTBSP1, a promising isolate to degrade aflatoxin B1 (AFB1), caused to reduce the growth of Aspergillus flavus R5 and AFB1 content on pistachio nuts. Fluorescence probes revealed that the cell free supernatant fluid from UTBSP1 affects spore viability considerably. Using high-performance liquid chromatographic (HPLC) method, 10 fractions were separated and collected from methanol extract of cell free supernatant fluid. Two fractions showed inhibition zones against A. flavus. Mass spectrometric analysis of the both antifungal fractions revealed a high similarity between these anti-A. flavus compounds and cyclic-lipopeptides of surfactin, and fengycin families. Coproduction of surfactin and fengycin acted in a synergistic manner and consequently caused a strong antifungal activity against A. flavus R5. There was a positive significant correlation between the reduction of A. flavus growth and the reduction of AFB1 contamination on pistachio nut by UTBSP1. The results indicated that fengycin and surfactin-producing B. subtilis UTBSP1 can potentially reduce A. flavus growth and AFB1 content in pistachio nut.

• Mass Spectrometry Letters
• /
• v.5 no.4
• /
• pp.115-119
• /
• 2014

The Brazil nut (Bertholletia excelsa - Lecythidaceae) is considered a product with high economic value, being a food widely appreciated for its nutritional qualities. Although previous studies have reported the biochemical composition of Brazil nut oil, the knowledge regarding the phospholipid composition exhibits a disagreement: the composition of fatty acids present in the structures of phospholipids is reported as being different from the composition of the free fatty acids present in the oil. In this work, solid phase extraction (SPE) was employed to provide a fast extraction of the phospholipids from Brazil nuts, in order to compare the phospholipid profile of the in nature nuts and their fatty acids precursor present in the oil. The major phospholipids were characterized by mass spectrometry approach. Their fragmentation pattern through direct infusion electrospray ionization ion-trap tandem mass spectrometry ($ESI-IT-MS^2$) proved to be useful to unequivocal characterization of these substances. High resolution (HR) experiments through ESI using a quadruple time of flight mass spectrometry (QTOF) system were performed to reinforce the identifications.

• Korean Journal of Food Science and Technology
• /
• v.13 no.1
• /
• pp.1-5
• /
• 1981

Free and total amino acids of Korean hazel nut (Corylus heterophylla Fisch. var. Japonica koidz.) were identified by amino acid autoanalyzer (Technicon PNC-1 type). The results indicate that among 16 kinds of all free amino acids contained in hazel nut, arginine was the richest, and then came glutamic acid, proline, alanine, tyrosine and valine in that order. From the total amino acids which were closely related with the nutritional valuation, arginine was in the richest amount and then came with glutamic acid, proline, leucine, aspartic acid and valine.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.911-915
• /
• 2014

Pyrotechnic devices are widely used for space appendages. However, a cube satellite requirements do not permit the use of explosive pyrotechnic device. A nichrome burn wire release has typically been used for holding and release of deployable appendages of the cube satellite due to its simplicity and low cost. However, relatively low mechanical constraint force and system complexity for application of multi-deployable systems are disadvantages of the conventional mechanism. To overcome these drawbacks, we have developed a segmented nut type holding and release mechanism based on the nichrome burn wire release. The great advantages of the mechanism are much lower shock level and larger constraint force than the conventional mechanism using pyro. Flight model for on-orbit verification was developed and verified through release function test, vibration test and thermal vacuum test.

• Journal of Sasang Constitutional Medicine
• /
• v.14 no.3
• /
• pp.174-180
• /
• 2002

The jaundice means hyperbilirubinemia that it happens bilirubin is contained for much in the blood for the disorder of formation and evaluation about bilirubin. The dry nut is one of the representative medicine which made use of Tae eum in bokchang bujong byung(태음인의 복창부종병) and that is marked use of removing the obstruction of tae eum in, by removing the damping heat(습열) and that is to depend on not the circle of medicine but the food The diet cure of a dry nut might be profound in meaning because the jaundice, the disorder of liver and gall, can be considered in relation to Tae eum in bokchang bujong byung(태음인의 복창부종병) I make a report in the basis of the reliably remedial value about application of a diet cure that a dry not is used to the patient coming to my hospital for the jaundice of ruing his health in eating and drinking

• Carbon letters
• /
• v.9 no.3
• /
• pp.188-194
• /
• 2008

Porous carbon materials synthesized from various plant derived precursors i.e. seeds of [Castor (Ricinus communis), Soap nut (Sapindus sp.), Cashew-nut (Semecarpus anacardium), Jack fruit (Artocarpus heterophyllus), Safflower (Carthamus tinctorius), Ambadi (Crotolaria juncea), Neem (Azadirachta indica), Bitter Almond (Prunus amygdalus), Sesamum (Sisamum indicum), Date-palm (Phoenix dactylifera),Canola (Brassica napus), Sunflower (Helianthus annulus)] and fibrous materials from [Corn stem- (Zea mays), Rice straw (Oryza sativa), Bamboo (Bombax bambusa) and Coconut fibers (Cocos nucifera)] were screened to make supercapacitor in 5M KOH solution. Carbon material obtained from Jack fruit seeds (92.0 F/g), Rice straw (83.0 F/g), Soap nut seeds (54.0 F/g), Castor seeds (44.34 F/g) and Bamboo (40.0 F/g) gave high capacitance value as compared to others. The magnitude of capacitance value was found to be inversely proportional to the scan rate of measurement. It is suggested that carbon material should possess large surface area and small pore size to get better value of capacitor. Moreover, the structure of carbon materials should be such that majority of pores are in the plane parallel to the plane of electrode and surface is fluffy like cotton ball.

• Nuclear Engineering and Technology
• /
• v.55 no.8
• /
• pp.2905-2918
• /
• 2023

The valve assembly used in nuclear power plants is important safety-related equipment. In the new standard, the physical attributes are measured using a valve diagnosis test, which is used in the expansion to other non-tested valves using a quantitative test-basis methodology. With a motor-operated actuator, the state of stem's lubrication is related to physical attributes such as the stem factor and the friction coefficient. This study analyzed the numerical transient of fluid and solid lubrication with a squeeze film effect due to the loading rate on the stem and the stem nut using the experimental data. The differential equation that governs the motion mechanism of the stem and stem nut is established and analyzed. The flow rate, the fluid and the solid contact forces are calculated with the friction coefficient. Finally, we found that a change in the friction coefficient results from a change of the shear force in the solid contact mode during the interchange process between the solid contact mode and the fluid contact mode. The qualitative understanding of the squeeze film effect is expanded quantitatively for forces, thread surface distance, velocity, and acceleration, with consideration of the metal solid contact and fluid contact.

• Weed & Turfgrass Science
• /
• v.2 no.1
• /
• pp.30-37
• /
• 2013

The objective of this research was to understand herbicidal activity of essential oils isolated from leaves of pine (Pinus densiflora), nut pine (Pinus koraiensis), larch (Larix kaempferi) and khingan fir (Abies nephrolepsis) in Korea. In a seed bioassay, essential oils of nut pine, larch and khingan fir inhibited the growth of rapeseed (Brassica napus) seedlings by 50% at 4,766, 1,865, $5,934{\mu}g\;ml^{-1}$, respectively, however, that of pine did not show any herbicidal effect. In a green house experiment, fall panicum, Southern crabgrass, sorghum, barnyardgrass, quackgrass, black nightshade, Indian jointvetch, velvet leaf, and Japanese morningglory were controlled in 24 hours by the foliar application of 10% essential oils from pine, nut pine, larch and khingan fir. The treated plant parts showed burndown effect, however, new shoots appeared 3 days after treatment. Results of GC-MS analysis showed that essential oils from pine, nut pine, larch and khingan fir contained 16, 25, 25, and 16 compounds, respectively, with hydrocarbons, alcohols, ketones, and esters. The major compounds of the essential oils were 3-carene, bornyl acetate, camphene, limonene, ${\alpha}$-pinene, ${\beta}$-pinene and ${\beta}$-phellandrene.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.2
• /
• pp.165-172
• /
• 2015

The objective of this study was to investigate the antioxidant and antiobesity activities of various color resources extracted from natural plants such as, clove, persimmon, gall nut, amur cork, gardenia, safflower, and annatto. Total phenolic content was the highest in gall nut extract (2,441.45 mg/kg) followed by clove extract (1,346.48 mg/kg). DPPH, and ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP) were also higher in gall nut extract. ${\alpha}$-Glucosidase inhibitory activity ($IC_{50}$) was highest in persimmon extract ($22.83{\mu}g/mL$) followed by gall nut extract. ${\alpha}$-Amylase and lipase inhibitory activities were also higher in persimmon extract (49.45% and 61.01%, respectively). Lipid accumulation in 3T3-L1 cells was lower in persimmon, clove, and annatto extracts (81.54%, 83.36%, and 85.70% at $20{\mu}g/mL$, respectively). Triglyceride content in 3T3-L1 cells was lowest in clove extract (66.11%) followed by persimmon extract (88.88%). The results of this study suggest that gall nut extract has the highest antioxidant activity, whereas persimmon and clove extract show the antiobesity activities by inhibition of digestive enzymes and fat accumulation in 3T3-L1 cells. These extracts are useful materials for the development of antioxidant and antiobesity functional foods.