New feasible quarantine disinfestation using ethyl formate for termites and ants on imported lumber

Kim Dong bin,Kim Kyung won,박민구,Roh Gwang Hyun,Cha Dong H.,Lee Byung ho 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.4

The interception of exotic ants and termites from stone and lumber imported into Korea is on the rise, including Solenopsis invicta. Currently, a relatively long exposure (24 h) of methyl bromide (MB) fumigation is the only practical disinfestation option for exotic ants and termites on imported stone and lumber. In this study, ethyl formate (EF) wase evaluated as a potential MB alternative to disinfest ants and termites in imported lumber, with a focus on S. invicta. As S. invicta is not established in Korea, we first determined whether Reticulitermes speratus, established in Korea, could be considered as an EF surrogate of S. invicta. From 1 h EF fumigation trials, workers of S. invicta were more sensitive to EF than those of R. speratus based on lethal concentration × time causing 99% mortality (LCt 99% ), supporting that R. speratus can be used as an EF surrogate of S. invicta. When R. speratus workers were further fumigated with EF for 4 h at four different temperatures, LCt 99% values for R. speratus workers were 108.00, 63.31, 77.24, and 67.24 g h/m 3 at 2, 5, 13, and 23 ◦ C, respectively. From scale-up (0.65 m 3 ) and commercial scale (76.4 m 3 ) trials containing two infestation-prone lumber species, lauan (Shorea spp.) and acacia (Acacia spp.), 140 g/m 3 EF at >5 ◦ C for 4 h resulted in the complete control of R. speratus workers, suggesting that 140 g/m 3 4 h-EF-fumigation may be applicable as a potential MB-alternative treatment for disinfestation of invasive S. invicta on imported lumber.

Ethyl formate fumigation for postharvest disinfestation of tropical commodities

Dong H. Cha,Bong-su Kim,Taehyung Kwon,Min-Goo Park,Byung Ho Lee 한국응용곤충학회 2022 한국응용곤충학회 학술대회논문집 Vol.2022 No.10

Chemical ecology and low dose postharvest fumigation as components of a systems approach for quarantine security

Dong H. Cha 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

Effective phytosanitary fumigation can prevent the introduction of exotic insects into new areas where they become pests. Traditionally Probit 9 level control (99.9968%) was considered as a stand-alone quarantine treatment. However, unacceptable phytotoxic damage often associated with high-dose treatment to realize Probit 9 level control of a large number of pests has often restricted its practical application. Therefore, quarantine security is being achieved for some commodities using a “systems approach”, where quarantine pests are cumulatively reduced to acceptable levels using independent, pre- and postharvest measures that comprise a systems that effectively mitigate the pest. Preharvest reductions in population through the study and application of chemical ecology involving insect behavior modifying chemicals can be an integral part of systems approach. This results in low pest prevalence prior to end point treatment, where pests may be effectively controlled using a less-than-Probit 9 level, low-dose treatment. In this talk, I discuss the chemical ecology of invasive quarantine pests including Drosophila suzukii and its perspective in the effective end point fumigation treatment using ethyl formate.

Chemical ecology and low dose postharvest fumigation as components of a systems approach for quarantine security

Dong H. Cha 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

An Effective and Efficient Button Layout of a Smartwatch for Standing and Walking

Dong Yeong Jeong,Sung H. Han,Hojun Cha 대한인간공학회 2016 대한인간공학회 학술대회논문집 Vol.2016 No.06

The aim of this study is to investigate the user’s touch task performance of a smartwatch with various button layouts and mobility conditions. Since a smartwatch has a touch-based screen, interactions occur on the screen. However, the screen sizes are relatively smaller than those of other mobile devices. It makes users difficult to touch buttons especially in the walking conditions because body movements disturb users to interact with smartwatches. The appropriate button size and spacing should be considered for comfortable interactions. In this study, task performance time, error rate, and overall satisfaction were measured in an experiment. Participants conducted touch tasks in various conditions of mobility (standing and walking) and button layouts; 5 kinds of button size (3㎜, 4.5㎜, 6㎜, 7.5㎜, and 9㎜) and 3 conditions of button spacing (0㎜, 3㎜, and 6㎜). The numbers (1, 2, and 3) were randomly shown on the three buttons each. Participants touched the three buttons in the numerical order. The results showed that task performance times were shorter in the standing condition, large button sizes and spacing than walking condition, small button sizes and spacing each. The button spacing becomes sensitive to the task performance time when the button size is small. Error rates were lower in the standing condition and large button sizes than walking condition and small button sizes each. Especially, the error rates rapidly dropped when the button size becomes greater than 6㎜. The overall satisfactions were higher when participants stand, button sizes and spacing are large. A large button needs to be provided to the users when they walk. When the button should be designed small, the large spacing can be considered. The button size should be greater than 6mm for the high touch task accuracy.

Core Stabilization With the Lumbar Extension Exercise in Low Back Pain

Dong-koog Noh,Young-joo Cha,Dae-hun Kim,Joshua (Sung) H. You 한국전문물리치료학회 2018 한국전문물리치료학회지 Vol.25 No.4

Background: We developed a novel integrative lumbar stabilization technique that combines lumbar extension (LE) exercise with abdominal drawing-in maneuver (ADIM) to ameliorate low back pain (LBP) associated with neuromuscular imbalance and instability, based on the collective evidence of contemporary spinal rehabilitation. Objects: The specific aim of the present study was to investigate the effects of LE exercise with and without ADIM on core muscle strength, lumbar spinal instability, and pain, as well as functional characteristics in individuals with LBP using advanced radiographic imaging techniques. Methods: patients with mechanical LBP (N = 40, 6 males; 35.1±7.6 years) were recruited and randomly assigned either to the combined LE and ADIM (experimental group) or the LE alone (control group). Outcome measures included the visual analog scale, the modified Oswestry Disability Index, muscle strength imbalance (MSI), and radiographic imaging. The lumbar intervertebral displacement (LID), intervertebral (IV) and total lumbar extension (TLE) angles were calculated to evaluate the lumbar segmental instability. Results: The experimental group showed significant differences in the L3-L4, L5-S1 LIDs, L4-L5 and L5-S1 IV angles, and TLE angle as compared to the controls (p<.05). Immediate pain reduction and muscle strength imbalance ratio were significantly different between the groups (p<.05). Conclusion: These results suggest that the addition of ADIM significantly increased lumbar spinal stabilization in individuals with LBP, thereby reducing pain associated with functional lumbar flexion during daily activities.

연구원 활동 : 발표논문요약 ; < 화학공학분야 >

(H . T . Jang),(W . S . Cha),(Dong Sup Doh) 고려대학교 공학기술연구소 1996 생산기술연구소보 Vol.3 No.-

A Combustion Instability Analysis of a Model Gas Turbine Combustor by the Transfer Matrix Method

Dong Jin Cha,Jay H. Kim,Yong Jin Joo 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

Combustion instability is a major issue in design of gas turbine combustors for efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and the change in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict selfexcited combustion instability of gas turbine combustors, a new stability analysis method based on the transfer matrix method is developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use the advantages of not only the transfer matrix method but also well-established classic control theories. The approach is applied to a simple gas turbine combustion system to demonstrate the validity and effectiveness of the approach.

Catalytic transfer hydrogenation of ethyl levulinate to γ-valerolactone over zirconium-based metal–organic frameworks

Valekar, Anil H.,Cho, Kyung-Ho,Chitale, Sachin K.,Hong, Do-Young,Cha, Ga-Young,Lee, U-Hwang,Hwang, Dong Won,Serre, Christian,Chang, Jong-San,Hwang, Young Kyu The Royal Society of Chemistry 2016 GREEN CHEMISTRY Vol.18 No.16

<P>A series of highly crystalline, porous, zirconium-based metal-organic frameworks (Zr-MOFs) with different ligand functionalities and porosities were applied for catalytic transfer hydrogenation of ethyl levulinate (EL) to form gamma-valerolactone (GVL), using isopropanol as a hydrogen donor. The roles of the ligand functionality and the metal center of the Zr-MOFs were identified and reaction parameters optimized, for selective production of GVL. The maximum yield of GVL (up to 92.7%) was achieved in 2 h at 200 degrees C with UiO-66(Zr). Interestingly, zirconium trimesate (MOF-808) emerged as the most suitable candidate, with the highest GVL formation rate (94.4 mu mol g(-1) min(-1)) among the catalysts tested at 130 degrees C. It was also found to be effective in conversion of EL to GVL in an open system using the solvent refluxing method. Both the catalysts (UiO-66(Zr) and MOF-808) were recycled at least five times under their specified reaction conditions without a notable change in catalytic activity and product selectivity. Fresh and recycled catalysts were characterized in detail using X-ray powder diffraction (XRD), N-2 adsorption-desorption, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) in order to understand the stability and structural changes that occurred in the catalysts. Finally, a plausible reaction mechanism was presented on the basis of active sites present in catalysts confirmed by characterization results.</P>

Circulating TNF receptors predict cardiovascular disease in patients with chronic kidney disease

Bae, Eunjin,Cha, Ran-Hui,Kim, Yong C.,An, Jung N.,Kim, Dong K.,Yoo, Kyung D.,Lee, Su M.,Kim, Myoung-Hee,Park, Jung T.,Kang, Shin-Wook,Park, Jae Y.,Lim, Chun S.,Kim, Yon S.,Yang, Seung H.,Lee, Jung P. Williams & Wilkins Co 2017 Medicine Vol.96 No.19

<P>We prospectively recruited 984 patients with CKD from 11 centers between 2006 and 2012. The levels of cTNFR1 and cTNFR2 were determined by performing an enzyme-linked immunosorbent assay. During the mean follow-up period of 4 years, 36 patients experienced a CVD event. The median serum concentrations of cTNFR1 and cTNFR2 were 2703.4 (225.6-13,057.7) and 5661.0 (634.9-30,599.6) pg/mL, respectively, and the cTNFR1 level was closely correlated with the cTNFR2 level (r=0.86, P < .0001). The urinary protein-to-creatinine ratio (UPCR) and estimated glomerular filtration rate (eGFR) were significantly correlated with the cTNFR2 level (r=0.21 for UPCR, r=-0.67 for eGFR; P<.001 for all). Similar correlations were observed for serum cTNFR1 (r=0.21 for UPCR, r=-0.75 for eGFR; P < .001 for all). In the Cox proportional hazard analyses, cTNFR1 (hazard ratio [HR] 2.506, 95% confidence interval [CI] 1.186-5.295, P=.016) and cTNFR2 (HR4.156, 95% CI 1.913-9.030, P < .001) predictedCVDrisk even after adjustment for clinical covariates, such as UPCR, eGFR, and high-sensitivity C-reactive protein. cTNFR1 and 2 are associated with CVD and other risk factors in CKD, independently of eGFR and UPCR. Furthermore, cTNFRs could be relevant predictors of CVD in CKD patients.</P>