Influence of Al2O3 Content and Cooling Rate on Crystallization in Fe2O3–CaO–SiO2–Al2O3 Systems

Tae Jun Park,Joon Sung Choi,Dong Joon Min 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

The behavior of silico-ferrite of calcium and aluminum (SFCA) phases and the influence of sintered ore quality were investigatedusing a confocal laser scanning microscope to understand how the Al2O3content of iron ore affects the sintered orestructure and the crystallization behavior of SFCA in a Fe2O3–CaO–Al2O3–SiO2 pseudo-quaternary system. The experimentalresults were used to inform simulations of the heterogeneous dynamic behavior in response to the rapid temperature changesand various chemical compositions typically encountered in actual sintering processes. Increasing the Al2O3content in theFe2O3–CaO–Al2O3–SiO2 pseudo-quaternary system led to the hematite content decreasing, which affects the reducibilityof the sintered ore. The correlation between the creation of SFCA and the cooling effect associated with varying the Al2O3is discussed in detail.

Elevated TRAF2/6 expression in Parkinson's disease is caused by the loss of Parkin E3 ligase activity.

Chung, Ji-Yun,Park, Hee Ra,Lee, Su-Jin,Lee, Sun-Hye,Kim, Jin Sik,Jung, Youn-Sang,Hwang, Sang Hyun,Ha, Nam-Chul,Seol, Won-Gi,Lee, Jaewon,Park, Bum-Joon United States and Canadian Academy of Pathology [e 2013 Laboratory investigation Vol.93 No.6

<P>Parkinson's disease (PD) is the second leading neurodegenerative disease, and is known to be induced by environmental factors or genetic mutations. Among the verified genetic mutations of PD, Parkin, isolated from the PARK2 locus, shows an autosomal recessive inheritance pattern and is known to be an E3 ligase. However, the physiological target of Parkin and the molecular mechanism of Parkin-deficiency-induced PD have not been clearly demonstrated until now. It has recently been proposed that inflammation, suggesting as a causal factor for PD, is enhanced by Parkin deficiency. Thus, we examined the relationship between inflammation-related factors and Parkin. Here, we provide the evidence that Parkin suppresses inflammation and cytokine-induced cell death by promoting the proteasomal degradation of TRAF2/6 (TNF-α receptor-associated factor 2/6). Overexpression of Parkin can reduce the half-lives of TRAF2 and TRAF6, whereas si-Parkin can extend them. However, mutant Parkins did not alter the expression of TRAF2/6. Thus, loss of Parkin enhances sensitivity to TNF-α- or IL-1β-induced JNK activation and NF-κB activation. Indeed, si-Parkin-induced apoptosis is suppressed by the knockdown of TRAF6 or TRAF2. We also observed elevated expression levels of TRAF6 and a reduction of IκB in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced PD mouse model. Moreover, elevated expression levels or aggregation of TRAF6 were detected in approximately half of the human PD tissues (7/15 cases) and 2 cases, respectively. In addition, TRAF6 and Parkin expression levels show a reverse relationship in human PD tissues. Our results strongly suggest that the reduction of Parkin or overexpression of TRAF2/6 by chronic inflammation would be the reason for occurrence of PD.</P>

LNT를 통해 분석한 국립공원 탐방목적과 산행 윤리 의식의 상관성 : 내장산국립공원 백양사지구와 남창지구를 중심으로

최형철(Choi Hyung Chul),박재철(Park Jae Chul),노재현(Roh Jae Hyun),신상섭(Shin Sang Sup),허준(Huh Joon) 한국산림휴양학회 2010 한국산림휴양학회지 Vol.14 No.3

본 연구는 LNT 항목의 분석을 통해서 산행 목적과 산행윤리의식 사이의 차이를 규명하기 위하여 수행되었다. 이를 위해서, 내장산국립공원의 백양사지구와 남창지구를 사례로 연구를 수행하였다. 이를 통해 국립공원 방문목적에 따라서 윤리 의식이 유의한 차이가 있음을 확인할 수 있었다. 다시 말하면, 산행목적의 탐방객이 행락 목적의 탐방객보다 윤리 의식이 높은 것을 확인할 수 있었다. This study was performed to identify the difference between purpose and ethics consciousness of national park visit through analysis of LNT(Leave No Trace) items. For this, case study was performed in the Baekyangsa and Namchang district in Naejang national park. Study methods were questionnaire and statistic analyses. Through these, the difference of Ethics Consciousness of national park visit according to visit purpose of one was identified. In other words, it was identified that visitors for climbing purpose had higher than those for pleasure-making in Ethics Consciousness of National Park Visit.

대형 할인매장 주차장 이용만족도의 영향요인 분석

임준범 ( Joon Bum Lim ),이수범 ( Soo Beom Lee ),성정곤 ( Jung Gon Sung ),박준태 ( Jun Tae Park ) 한국안전학회(구 한국산업안전학회) 2012 한국안전학회지 Vol.27 No.4

This research has analyzed factors affecting customers` satisfaction when they use parking lots of big retailers so that, in case of constructing, operating or managing such retailers, proper measures can be come up with. The analysis has been implemented on the basis of survey, and influence factors including entry/exit lamp, parking cars`` traffic flow, parking type, pedestrians`` movement after parking and safety. Parking lot users`` satisfaction has been analyzed by using the Structural Equation Modelling and, as a result of it, in case of a detached or single building, pedestrians movement flow after parking contributed the most to the users`` satisfaction, while, in case of multipurpose complex, parking cars traffic flow has the most influential factor. It is interpreted that users of a single building put a bigger emphasis on entry to the shop and their way back to the parked area after their shopping while customers of multipurpose complex might have various purposes of visiting the place and there are relatively more cars so that they put more emphasis on traffic counterflow, other cars and pedestrians.

Unbalanced ZCP Compensation Method for Position Sensorless BLDC Motor

Park, Joon Sung,Lee, Ki-Doek,Lee, Sung Gu,Kim, Won-Ho Institute of Electrical and Electronics Engineers 2019 IEEE transactions on power electronics Vol.34 No.4

<P>This letter presents a position sensorless control method of brushless dc (BLDC) motors considering unbalanced zero-crossing detection of back electromotive force (back EMF). The zero-crossing point (ZCP) of back EMF voltage is detected by comparing the dc-link voltage with the back EMF voltage. The unbalanced ZCP detection is caused by the dc-link voltage drop, dc-link offset voltage, and a motor having asymmetric back EMFs. Because the sensorless BLDC motor control is based on unbalanced ZCP detection, issues with torque ripple and current ripple may be increased. Therefore, sensorless operation with unbalanced ZCP detection may be unstable. In this study, an improved sensorless control method based on a simple compensation algorithm using ZCP signals is proposed. Using the proposed control method, balanced commutation instants can be obtained and the benefits of high-performance operation of BLDC motors can be accomplished. Through application of the proposed method, the effectiveness of the proposed method was experimentally verified.</P>

Polyphenolic compounds from Korean <i>Lonicera japonica</i> Thunb. induces apoptosis via AKT and caspase cascade activation in A549 cells

Park, Kwang Il,Park, Hyeonsoo,Nagappan, Arulkumar,Hong, Gyeong Eun,Yumnam, Silvia,Lee, Ho Jeong,Kim, Eun Hee,Lee, Won Sup,Shin, Sung Chul,Kim, Jin A,Lee, Sang Joon,Ma, Jin Yeul,Min, Taesun,Heo, Jeong D.A. Spandidos 2017 Oncology letters Vol.13 No.4

<P><I>Lonicera japonica</I> Thunb. (<I>L. japonica</I> T.) has historically been used in Korean herbal medicine due to its anticancer and protective effects on the respiratory system. In the present study, the polyphenolic compounds in <I>L. japonica</I> T. were investigated using high-performance liquid chromatography coupled with tandem mass spectrometry, and its anticancer effects on A549 non-small-cell lung cancer cells were studied. Polyphenolic compounds potentially inhibit A549 cells in a dose-dependent manner. Flow cytometry and western blot analysis demonstrated that polyphenolic compounds induce apoptosis by regulating the protein expression levels of caspases, poly-(ADP-ribose) polymerase and the B-cell lymphoma-2-associated X-protein/B-cell lymphoma-extra large ratio. Furthermore, polyphenolic compounds inhibited mitochondrial membrane potential activity. Caspase-3 activity was increased in a dose-dependent manner and polyphenolic compounds inhibited the activation of protein kinase B by dephosphorylation. These results suggest that polyphenolic compounds in A549 cells indicate the anticancer activity through the induction of apoptosis.</P>

Acid-Base and Spectroscopic Properties of 1,4-Benzodiazepines in Sodium Dodecyl Sulfate Micellar Solutions

Joon Woo Park,Hye Sung Cho Korean Chemical Society 1990 Bulletin of the Korean Chemical Society Vol.11 No.1

Acid-base equilibria and spectroscopic properties of diazepam and chlorodiazepoxide were investigated in sodium dodecyl sulfate (SDS) micellar solutions as functions of pH. The results were compared with the behaviors in homogeneous aqueous media. The presence of SDS increased the $pK_a$ of chlorodiazepoxide to 6.3 from 4.7, while it has little effect on the $pK_a$ of diazepam. The acidic protonated form of diazepam was moderately fluorescent when the solution was excited at 350 nm, and emissnion intensity of the species was enhanced about 5 fold by the presence of SDS. On the other hand, the acidic solution of chlorodiazepoxide was non-fluorescent, but the neutral solution of the compound was fluorescent upon excitation at 350 nm. The emission peak of the neutral chlorodiazepoxide shifted to shorter wavelength region without significant change in the emission intensity upon the addition of SDS. Procedures for assay of the individual drugs from their mixture by the use of SDS micelle were discussed.

KAAACI Allergic Rhinitis Guidelines: Part 2. Update in Non-pharmacological Management

Park Do-Yang,Lee Yong Ju,Kim Dong-Kyu,Kim Soo Whan,Yang Hyeon-Jong,Kim Do Hyun,Jun Young Joon,Park Sang Chul,Kim Bong-Seong,Yang Song-I,Lee Il Hwan,Kim Minji,Ryu Gwanghui,강성윤,Kim Mi-Ae,이상민,Kim Hyun-Ju 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.2

Allergic rhinitis is the most common chronic disease worldwide. Various upper airway symptoms lower quality of life, and due to the recurrent symptoms, multiple treatments are usually attempted rather than one definitive treatment. There are alternatives to medical (medication-based) and non-medical treatments. A guideline is needed to understand allergic rhinitis and develop an appropriate treatment plan. We have developed guidelines for medical treatment based on previous reports. The current guidelines herein are associated with the “KAAACI Evidence-Based Guidelines for Allergic Rhinitis in Korea, Part 1: Update in pharmacotherapy” in which we aimed to provide evidence-based recommendations for the medical treatment of allergic rhinitis. Part 2 focuses on non-pharmacological management, including allergen-specific immunotherapy, subcutaneous or sublingual immunotherapy, nasal saline irrigation, environmental management strategies, companion animal management, and nasal turbinate surgery. The evidence to support the treatment efficacy, safety, and selection has been systematically reviewed. However, larger controlled studies are needed to elevate the level of evidence to select rational non-medical therapeutic options for patients with allergic rhinitis.

Nondestructive Evaluation of Rayleigh Pitch-Catch Contact Ultrasound Waves on Impacted-Damaged Composites

Park, Je Woong,Yang, In Young,Im, Kwang Hee,Hsu, David K.,Song, Sung Jin,Kim, Hak Joon,Cho, Young Tae Trans Tech Publications, Ltd. 2007 Materials science forum Vol.566 No.-

<P>In particular, CFRP (carbon fiber reinforced plastics) composite materials have found wide applicability because of their inherent design flexibility and improved material properties. CFRP composites were manufactured from uni-direction prepreg sheet in this paper. However, impacted composite structures have 50-75% less strength than undamaged structures. It is desirable to perform nondestructive evaluation to assess material properties and part defect in order to ensure product quality and structural integrity of CFRP. In this work, a CFRP composite material was nondestructively characterized and a pitch-catch technique was developed to measure impacteddamaged area using an automated-data acquisition system. Also one-sided mode was performed to scan defect both manual contact measurement and an immersion tank. It is found a pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composite, including fiber orientation, low level porosity, ply waviness, and cracks. The paper describes the depth of the sampling volume with the head-to-head miniature Rayleigh probes and also ultrasonic C-scan images are acquired experimentally using one-sided measurement and a conventional scanner.</P>

On Improving Parallelized Network Coding with Dynamic Partitioning

Park, K,Joon-Sang Park,Ro, W W IEEE 2010 IEEE transactions on parallel and distributed syst Vol.21 No.11

<P>In this paper, we investigate parallel implementation techniques for network coding. It is known that network coding is useful for both wired and wireless networks and it also mitigates peer/piece selection problems in P2P file sharing systems. However, due to the decoding complexity of network coding, there have been concerns about adoption of network coding in practical network systems and to improve the decoding performance, the exploitation of parallelism has been proposed previously. In this paper, we argue that naive parallelization strategies of network coding may result in unbalanced workload distribution, and thus, limiting performance improvements. We further argue that a higher performance enhancement can be achieved through balanced partitioning methods in parallelized network coding and propose new parallelization techniques for network coding. Our experiments show that on a quad-core processor system, proposed algorithms exhibit up to 5.69 speedup which is better than the linear speedup with the influence of additional cache. Moreover, on an octal-core system, our algorithms even achieve speedup of 8.46 compared to a sequential network coding and 43.3 percent faster than an existing parallelized technique using 1 Mbytes data with 1,024 \times 1,024 coefficient matrix size.</P>