Cathodic Limiting Current Density in Copper Electrolysis

Maru, Yoichi,Ito, Shigeharu,Oyama, Shin,Kondo, Yoshio 대한금속재료학회(대한금속학회) 1971 대한금속·재료학회지 Vol.9 No.3

In the electrode position on the vertical plate cathode immersed in an unstirred electrolyte, a concentration boundary film is formed along the cathode surface and the cathodic limiting current density is determined by the transfer rate of copper ion through the film. Moreover, the decrease of copper ion concentration in this film causes an upward natural convective flow of electrolyte along the surface and the average cathodic limiting current density is expressed by equation (6). The effects of copper ion concentration in the bulk electrolyte and of the height of the cathode on the cathodic limiting current density can be interpreted by this equation. The natural convective flow becomes turbulent when the Reynolds number concerning the film thickness exceeds 200 and the experimental results were summarized by an equation composed of dimensionless numbers of Sh, Sc and Gr. The apparent activation energy of diffusion of copper ion in the electrolyte was estimated at 4.8 ㎉/㏖.

Feasibility of Gastric Cancer Surgery at Low Volume Hospitals

Maru Kim,박종경,김성근,최승혜,윤상섭,이성 대한위암학회 2010 Journal of gastric cancer Vol.10 No.4

Purpose: Most gastric cancer patients undergo operations at large tertiary hospitals in Korea. However, some patients are treated at low volume hospitals. We investigated patient outcomes after gastric surgery at a secondary hospital and compared with outcomes of large volume centers. Materials and Methods: We included 184 patients who underwent gastric surgery for gastric cancer at our hospital from January 2003 to December 2008. We conducted a retrospective study and evaluated the clinicopathological characteristics, clinical outcomes and survival rate of patients. Results: Mean age was 61.7 years old. Male to female ratio was 2.2 : 1. Proportion of early gastric cancer was 38.6% and that of advanced gastric cancer was 61.4%. The 5 year overall survival rate of 184 patients was 66.3%. The overall survival rate was significantly lower for people over 62 years old. The morbidity rate and mortality at our hospital were 10.3% and 0.5%, respectively. Conclusions: The overall survival rate, morbidity and mortality were similar to those of the previous reports from Korea. Treatment of gastric cancer at a secondary hospital is feasible and safe. Standardization of operations and management of gastric cancer patients of the Korean Gastric Cancer Association is the most important factor to achieve these outcomes.

Closed Thoracotomy : Tips & Pitfalls

Maru Kim 대한외과학회 2021 대한외과학회 학술대회 초록집 Vol.2021 No.11

Management of Trauma Related Hernia

Maru Kim 대한외과학회 2021 대한외과학회 학술대회 초록집 Vol.2021 No.11

The Relationship between Temperature Patterns and Urban Morfometri in the Jakarta City, Indonesia

Maru, Rosmini,Ahmad, Shaharuddin Korean Society for Atmospheric Environment 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.2

Sky View Factor (SVF) is one of the urban morfometri parameters that impact on the Urban Heat Island (UHI). SVF analisys was conducted in the city of Jakarta to investigate the relationship between urban temperature with urban morfometri. Jakarta City is the most populous city in the world that has a surrounding area $66,152km^2$ and the total population around 23 million people. The population of the city is the sixth highest in the world today. SVF measurements done by taking pictures at the six stations that have different morphological characteristics namely (1) the narrow streets Apartment Cempaka Mas (JS ITC), (2) the width of the road Apartment Cempaka Mas (JL ITC), (3) in front of Colleges Kanisius (DKK), (4) in front of office Journalist of Indonesia (DKWI), (5) Utan Kayu (UK), and (6) Tambun (TB). SVF value is obtained from the photgraphic image. Taking pictures at the location using a Nikon D90 camera with a Nikon Fisheye Nikkor 10.5 mm 1 : 2.8 G ED, further processed through a global mapper program. Therefore, the SVF derived from the six stations that vary 0.21 to 0.78. Temperature measurement is done during daylight hours from 06:00 am to 18:00 pm during the Western Part of Indonesia (WIB). Measurements performed at three different times, namely working days (HK) regular holidays (HCB) national holidays (HCN). The results showed that the highest average temperature of $33.32^{\circ}C$, occurring at UK station (SVF=0.45) at the time of HCB. Meanwhile, the average low temperature of $31.22^{\circ}C$ occurred at JLITC station (SVF=0.42). The two-time occurred on ordinary holidays. Maximum temperature of $38.4^{\circ}C$ occurred in Utan Kayu station (SFV=0.45) that occurred at 11.00 hrs, normal holidays. Furthermore minimum temperature 24.5 occurred at Tambun station (SVF=0.78) at 06.00 hrs in the morning at the usual holidays and national holidays. In general, the results showed that areas with large SVF has a lower temperature compared with areas with smaller SVF. Though, are not the only factors that matter, but this research may show that an increase in temperature in the city of Jakarta. Therefore, it is necessary to mitigate the serious from the government or society.

Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

Maru Park,조중현,조성기,최진,Chun-Hwey Kim,박장현,임홍서,최영준,문홍규,배영호,Sun-youp Park,Ji-Hye Kim,Dong-Goo Roh,Hyun-Jung Jang,Young-Sik Park,정민지 한국우주과학회 2015 Journal of Astronomy and Space Sciences Vol.32 No.4

By using the Optical Wide-field Patrol (OWL) network developed by the Korea Astronomy and Space Science Institute (KASI) we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), and Oukaïmeden (Morocco). The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO). These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150) for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE) from the Joint Space Operation Center (JSpOC). Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

Temporary Closure for Sternotomy in Patient with Massive Transfusion Might Be Lethal

( Maru Kim ),( Joongsuck Kim ),( Sung Jeep Kim ),( Hang Joo Cho ) 대한외상학회 2017 大韓外傷學會誌 Vol.30 No.1

A 58-year-old male visited our emergency room for multiple traumas from explosion. On initial evaluation, hemopneumoperitoneum with liver laceration (grade 4) and colon perforation was identified. Hemopericardium with cardiac tamponade was also identified. Shrapnel was detected in the right ventricle. Damage control surgery was planned due to condition of hypotension. In operation room, control over bleeding was achieved after sternotomy, pericardiotomy, and laparotomy. Massive transfusion was done during operation. After gauze packing, operation was terminated with temporary closure (TC). Sanguineous fluid was drained profusely. Disseminated intravascular coagulopathy was confirmed through laboratory findings. No extravasation was discovered at hepatic angiogram. On re-operation, there was no active bleeding but oozing from sternotomy site was identified. Bone bleeding was impossible to control. Finally, reoperation was ended after gauze packing and TC all over again. The patient could survive for only a day after re-operation. [ J Trauma Inj 2017; 30: 12-15 ]

Hydronephrosis during Conservative Treatment for a Renal Injury Patient

( Maru Kim ),( Joongsuck Kim ),( Sung Jeep Kim ),( Hang Joo Cho ) 대한외상학회 2017 大韓外傷學會誌 Vol.30 No.2

A 21-year-old male visited our emergency room. He could not remember the mechanism of injury. He was found beside a motorcycle. Initial vital sign was stable. Observation and conservative treatment were planned at the intensive care unit (ICU). On the third day at ICU, he complained sudden flank pain. It was colicky and hard to control. Without the pain, he had no specific symptom, sign, or laboratory findings. On computed tomography, renal pelvis was filled with hematoma which induced hydronephrosis. Double-J catheter and percutaneous nephrostomy was implemented by an intervention radiologist. Hematome in the renal pelvis was aspirated during the procedure. Symptom of the patient was subsided after the procedure. He was discharged without specific complications. [ J Trauma Inj 2017; 30: 47-50 ]

A GEE approach for the semiparametric accelerated lifetime model with multivariate interval-censored data

Maru Kim,Sangbum Choi 한국통계학회 2023 Communications for statistical applications and me Vol.30 No.4

Effect of surgical timing and outcomes for appendicitis severity

Maru Kim,Sung Jeep Kim,Hang Joo Cho 대한외과학회 2016 Annals of Surgical Treatment and Research(ASRT) Vol.91 No.2

Purpose: This study was aimed to evaluate the effect of time of surgery for acute appendicitis on surgical outcomes to optimize the timing of appendectomies. Methods: Medical records of patients who underwent an appendectomy were reviewed to obtain data on time of symptom onset, time of hospital presentation, and start times of surgery. Surgical findings were used to define appendicitis as either uncomplicated or complicated. The uncomplicated group included patients with simple, focal, or suppurative appendicitis, and the complicated group included patients with gangrenous, perforated appendicitis or periappendiceal abscess formation. The 2 groups were analyzed by age, sex, and time. Results: A total of 192 patients were analyzed. The mean time from symptom onset to start of operation showed a significant difference between both groups (1,652.9 minutes vs. 3,383.8 minutes, P < 0.001). The mean time from hospital visit to start of operation showed no difference between both groups (398.7 minutes vs. 402.0 minutes, P = 0.895). Operating within 24 hours of symptom onset had a relative risk of 1.738 (95% confidence interval, 1.319–2.425) for complications. Operating more than 36 hours after symptom onset was associated with an increased risk of postoperative ileus and a longer hospital stay. Conclusion: Complicated appendicitis is associated with a delay in surgery from symptom onset rather than a delay at hospital arrival. Surgeons should take into account the time from symptom onset when deciding on the timing of appendectomy. We recommend that appendectomy be performed within 36 hours from symptom onset.