• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.390-397
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• 2010

Residual solvents in foods are defined as organic volatile chemicals used or produced in manufacturing of extracts or additives, or functional foods. The solvents are not completely eliminated by practical manufacturing techniques and they also may become contaminated by solvents from packing, transportation or storage in warehouses. Because residual solvents have no nutritional value but may be hazardous to human health, there is a need to remove them from the final products or reduce their amounts to below acceptable levels. The purpose of this study was to develop and evaluate an analytical method for the screening of residual solvents in health functional foods. Furthermore, the aim of this study was to constitute a reasonable management system based on the current state of the market and case studies of foreign countries. Eleven volatile solvents such as MeOH, EtOH, trichloroethylene and hexane were separated depending on their column properties, temp. and time using Gas Chromatography (GC). After determining the GC conditions, a sample preparation method using HSS (Head Space Sampling) was developed. From the results, a method for analyzing residual solvents in health functional foods was developed considering matrix effect and interference from the sample obtained from the solution of solvents-free health functional foods spiked with 11 standards solutions. Validation test using the developed GC/HSS/MS (Mass Spectrometry) method was followed by tests for precision, accuracy, recovery, linearity and adequate sensitivity. Finally, examination of 104 samples grouped in suits was performed by the developed HSS/GC/MS for screening the solvents. The 11 solvents were isolated from health functional foods based on vapor pressure difference, and followed by separation within 15 minutes in a single run. The limt of detection (LOD), limit of quantification (LOQ), recovery and coefficient of variation (C.V.) of these compounds determined by the HSS/GC/MS were found to be 0.1 pg/mL, 0.1-125 pg/g, 51.0-104.6%, and less than 15%, respectively. Using the developed HSS/GC/MS method, residual solvent from 16 out of 104 health functional products were detected as a EtOH. This method therefore seems t o be a valuable extension ofanalytical method for the identification of residual solvents in health functional food.

• Analytical Science and Technology
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• v.25 no.5
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• pp.292-299
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• 2012

GC/MS has been utilized for many applications due to great resolution and reproducibility, which made it possible to build up the database of mass spectrum, while HS-SPME has the advantage of solventfree extraction of volatile compounds. The combination of these two methods, HS-SPME GC/MS, enabled many scientific applications with various possibilities. In this study, the analysis of trail pheromone excreted from live Camponotus japonicus with the feature of solvent-free extraction was carried out and the optimization for this analysis was performed. The major compounds detected were n-decane, n-undecane, and n-tridecane. Optimization for the best detection of these hydrocarbons was processed in the point of SPME parameter (selection of fiber, extraction temperature, extraction time, etc.). The advantage of the analysis of live sample is to analyze phenomenon right after it is excreted by ants. But the experimental process has restriction of extraction temperature and time because of the analysis of live ants. Establishing the process of HS-SPME GC/MS applied to live samples shown in this study can be a breakthrough for the ecofriendly and ethical research of live things.

• Science of Emotion and Sensibility
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• v.9 no.2
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• pp.93-100
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• 2006

This paper aims at the development and clinical evaluation of the wireless gyro-mouse system. The wireless gyro-mouse system is a computer interface with gyro-sensor and wireless communication, for the patients with upper-extremity disabled from the traffic accident or stroke to use the computer software i.e. internet browser. In the development, we focused on, firstly, to make the system wireless for the patients to manipulate the mouse easily even on the bed or wheelchair, secondly, to insert the gyro-sensor into a headband for easy don-and-doff and aesthetic appearance, thirdly, to devise a click switch in case of $C5{\sim}C6$ patients and a head nodding detection in case of C4 patients for sending click message to computer operating system. We performed evaluation experiment for patients with upper-extremities disabled from spinal cord injury. The results show that the displacement error of the cursor position against the target position during linear (vertical/horizontal) movement manipulation decreased with trial number. The click rate per minute also increased with trial number. This indicates the developed wireless gyro-mouse system would be more useful to the patients with repetitive use.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.359-365
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• 2003

Headspace solid-phase microextraction(HS-SPME) was used to isolate the off-flavor volatile compounds, which are formed during the oxidation of porcine liver and unsaturated fatty acids in porcine liver induced by iron. Three fibers for HS-SPME method development were tested, and the polydimethylsiloxane/divinylbenzene(PDMS/DVB) fiber was selected as providing the best detection of analyzed compounds. In the oxidized arachidonic acid, the major compounds identified were hexanal, 1-octen-3-one(metallic), (Z)-4-heptenal, (E)-2-octenal, 1-octen-3-ol(mushroom), (Z)-2-nonenal (cardboard-like), and (E,E)-2,4-decadienal(fatty, oily). In the oxidized linolenic acid, the major ones were (E,E)-2,4-heptadienal(fishy), (E,E)-3,5-octadien-2-one and (E,Z)-2,6-nonadienal. Moreover, those of th oxidized porcine liver with iron were hexanal, 1-octen-3-one, (Z)-4-heptenal, (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal. These results showed that the fishy and metallic off-flavor in porcine liver were due to the oxidation of unsaturated fatty acids in porcine liver.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.85-98
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• 2009

The tau-p inversion algorithm is widely employed to generate starting models with most computer programs, which implement refraction tomography. This algorithm emphasises the vertical resolution of many layers, and as a result, it frequently fails to detect even large lateral variations in seismic velocities, such as the decreases which are indicative of shear zones. This study demonstrates the failure of the tau-p inversion algorithm to detect or define a major shear zone which is 50m or 10 stations wide. Furthermore, the majority of refraction tomography programs parameterise the seismic velocities within each layer with vertical velocity gradients. By contrast, the Generalized Reciprocal Method (GRM) inversion algorithms emphasise the lateral resolution of individual layers. This study demonstrates the successful detection and definition of the 50m wide shear zone with the GRM inversion algorithms. The existence of the shear zone is confirmed by a 2D analysis of the head wave amplitudes and by numerous closely spaced orthogonal seismic profiles carried out as part of a later 3D refraction investigation. Furthermore, an analysis of the shot record amplitudes indicates that a reversal in the seismic velocities, rather than vertical velocity gradients, occurs in the weathered layers. The major conclusion reached in this study is that while all seismic refraction operations should aim to provide as accurate depth estimates as is practical, those which emphasise the lateral resolution of individual layers generate more useful results for geotechnical and environmental applications. The advantages of the improved lateral resolution are obtained with 2D traverses in which the structural features can be recognised from the magnitudes of the variations in the seismic velocities. Furthermore, the spatial patterns obtained with 3D investigations facilitate the recognition of structural features such as faults which do not display any intrinsic variation or 'signature' in seismic velocities.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.12-20
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• 2004

In this paper, the detection of 1 g and 10 g averaged SAR on human head caused by PCS/IMT-2000 handhold phones is analyzed and discussed. Planar structured Single-Semi-disc MPA and double-Semi-disc MPA is designed and resonance characteristics with variety of design parameters are analyzed. As a result, 2.0 ㎓ center frequency, at the bandwidth of single-semi-disc MPA and double-semi-disc MPA are 15.5 ％ and 31 ％, respectively. And monopole antenna with W4 length is designed and compared with double-semi-disc MPA in SARs. The SARs caused by double-semi-disc MPA on folder type handset are 0.811 W/kg and 0.507 W/kg and are about 32.7 ％ lower than monopole-1.206 W/kg and 0.7552 W/kg. While the radiation pattern of the monopole antenna is symmetrical, that of planar structured antenna is asymmetrical and SAR caused by double-semi-disc MPA is less than SAR by the monopole antenna.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.91-94
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• 2012

This study was conducted to develop an algorithm for determination of abnormal body temperature in piglets through skin and core temperature database at normal condition. 5 piglets (mean BW : 46 kg) were employed for the experiment. They were adapted in the individual metabolism cage set at $22.5{\pm}2.0^{\circ}C$ of room temperature for 2 weeks before the measurement of body temperature. Ear, neck, head and subcutaneous neck temperature (as core temperature) of piglets were measured for every 1 minute during 30 consecutive days through 1mm k-type thermocouple wire and NI-devices (National Instruments Corporation, Austin, Texas, USA). Body temperature data were accumulated and integrated into the 1 day unit. Change of daily mean skin and core body temperatures in piglets were lowest at around 06:00, highest at around 14:00 and gradually decreased until the day after 06:00. Each skin temperatures were varied with the measuring site and largely depended on the room temperature changes. Established database of skin and core body temperature in piglets through this study can be applied to develop an algorithm for monitoring and determining the abnormal condition of animal by using radio frequency identification.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.483-490
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• 2012

Ready-to-eat chicken breasts were packaged in a multilayer, gas-tight tray with top film and various quality changes were investigated during the 24 wk of storage at $10^{\circ}C$. Over the storage period, total aerobes, mesophilic aerobic and anaerobic spore formers, and Clostridium spp. were not detected above 1.0 log CFU/g (detection limit). The residual oxygen ratio in the head space of tray and pH values tended to decrease with storage time, namely from initial values of 5.7% and 6.56 to 3.3% and 6.34 at week 24, respectively. Thiobarbituric acid reactive substances and volatile basic nitrogen values increased from 0.52 mg malonaldehyde (MA)/kg and 2.1 mg/100 g initially, to 3.70 mg MA/kg and 39.9 mg/100 g at week 24, respectively. In terms of the change in meat color during storage, the samples showed a slight increasing trend of CIE $a^*$, $b^*$, and ${\Delta}E$ values over the storage period until week 24 (p<0.05). The change in brine color showed a similar trend with meat of which Hunter $b^*$ and ${\Delta}E$ values increased slightly during storage during 24 wk (p<0.05). The values for the transmittance degree of brine in the samples tended to decrease. Moreover, values for the absorbance degree tended to increase with storage time until week 24. The sensory scores for color, texture, odour, and flavour were evaluated below 5.0 (marketability level) after 24 wk of storage. Based on this sensory evaluation, it could be concluded that retorted RTE chicken breast could remain marketable for at least 20 wk at $10^{\circ}C$.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.67-67
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• 2003

It is crucial to minimize setup errors of a cancer treatment machine using a high energy and to perform precise radiation therapy. Usually, port film has been used for verifying errors. The Korea Cancer Center Hospital (KCCH) has manufactured digital electronic portal imaging device (EPID) system to verify treatment machine errors as a Quality Assurance (Q.A) tool. This EPID was consisted of a metal/fluorescent screen, 45$^{\circ}$ mirror, a camera and an image grabber and could display the portal image with near real time KIRAMS has also made the acrylic phantom that has lead line of 1mm width for ligh/radiation field congruence verification and reference points phantom for using as an isocenter on portal image. We acquired portal images of 10$\times$10cm field size with this phantom by EPID and portal film rotating treatment head by 0.3$^{\circ}$, 0.6$^{\circ}$ and 0.9$^{\circ}$. To check field size, we acquired portal images with 18$\times$18cm, 19$\times$19cm and 20$\times$20cm field size with collimator angle 0$^{\circ}$ and 0.5$^{\circ}$ individually. We have performed Flatness comparison by displaying the line intensity from EPID and film images. The 0.6$^{\circ}$ shift of collimator angle was easily observed by edge detection of irradiated field size on EPID image. To the extent of one pixel (0.76mm) difference could be detected. We also have measured field size by finding optimal threshold value, finding isocenter, finding field edge and gauging distance between isocenter and edge. This EPID system could be used as a Q.A tool for checking field size, light/radiation congruence and flatness with a developed video based EPID.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.140-147
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• 1985

Seventy four Holstein heifers were randomly assigned over three trials to PRID-7+PG-6 and Synchromate B-9 regimens to synchronize estrus cycle for embryo transfer. Sexual behaviors; moounting, standing, orientation, chin-resting, sniffing, licking, rubbing and butting, vaginal swelling and mucus discharge were observed between 06-08, 12-14 and 18-20 h on 1st day and 00-02, 06-08, 12-14 and 18-20 h on 2nd day after removal of hormones. Synchromate-B treatment (81.6%) showed higher synchronized estrus rate than PRID treatment (77.8%) during observation period. Standing estrus was observed within 74 h after PG injection in PRID and within 52 h after removal of implant in Synchromate-B. About 68% of heifers in PRID and 74% of heifers in Synchromate-B showed standing estrus between 0-14 h on 2nd day after removal of the hormones. Synchromate-B resulted in a tighter synchrony of standing estrus than PRID. Incidence of average mounting and standing per head during observation period was 22.3 and 16.6 in PRID and 28.1 and 13.6 in Synchromate-B. The PRID showed peak in active mounting at 18-20 h on 1st day, however, the Synchromate-B showed at 0-2 h on 2nd day after removal of hormone. Active standing was shown between 18 h on 1st day to 20h on 2nd day in PRID, however, between 0-14 h on 2nd day after removal of hormone is Synchromate-B. There was slight difference in pattern of active mounting and standing during estrus between PRID and Synchromate-B. Conception rate of synchronized heifers transferred with fresh and frozen embryos by non-surgical and surgical methods was higher in synchromate-B (62.5%) than in PRID (38.5%). Chin-resting showed highest incidence among 6 sexual behavioral components in the both treatments. Synchromate-B showed higher incidence of chin-resting (16.6) than PRID (10.7). Synchromate-B group showed also higher incidence of orientation, sniffing and butting than PRID group. Synchromate-B resulted in more active sexual behaviors than PRID. The pattern of incidence of chin-resting, licking and butting was almost symmetrical in PRID with their peak values at 6-8 h on 2nd day, however in Synchromate-B chin-resting and sniffing was symmetrical with their peak values at 12-14 h on 2nd day after removal of hormone. There was tendency to increase vaginal swelling according to time passage of synchronized estrus in the both treatments. Incidence of mucus discharge in Synchromate-B was slightly higher than in PRID. Twenty to 40% was false negative in conception rate by tall painting before re-estrus day as judged by rectal palpation.