• Journal of Soil and Groundwater Environment
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• v.23 no.2
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• pp.23-29
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• 2018

This study explored secondary effects of the residual hydrofluoric acid (HF) after a hypothetical acid spill accident by investigating the long-term dissolution of minerals and leaching of pre-existing arsenic (As) from two soil samples (i.e., KBS and KBM) through batch and column experiments. An increase in the HF concentration in both soil samples resulted in a dramatic increase in the release of major cations, especially Si. However, the amounts of mineral dissolved were dependent on the soil type and mineral characteristics. Compared to the KBM soil, relatively more Ca, Mg and Si were dissolved from the KBS soil. The column experiment showed that the long-term dissolution rates of the minerals are closely associated with the acid buffering capacity of the two soils. The KBM soil had relatively higher effluent pH values compared to the KBS soil. Also, more As was leached from the KBM soil, with a more amorphous hydrous oxide-bound As fraction. These results suggest that the potential of heavy metal leaching by the residual acid after an acid spill will be influenced by heavy metal speciation and mineral structure in the affected soil.

• Clinical and Experimental Pediatrics
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• v.64 no.9
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• pp.473-479
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• 2021

Background: Malnutrition has a high incidence among pediatric surgical patients and contributes to increased risks of postoperative complications and extended hospital stays. Purpose: The present study aimed to determine the influence of preoperative nutritional status on the postoperative outcomes of pediatric patients who underwent elective gastrointestinal (GI) surgery. Methods: This prospective observational study was conducted at Cairo University Specialized Pediatric Hospital. According to the designated inclusion criteria, 75 surgical cases of both sexes were included. A structured questionnaire was developed and administered. This questionnaire included 3 main sections: demographic data and nutritional status parameters at admission and discharge. Pre- and postoperative nutritional statuses were compared. Results: According to both the subjective global nutritional assessment and STRONGKIDS score Questioner, more than 60% of patients in the upper GI patient group were at risk of malnutrition. Wasting status was most common in the upper GI patient group (67%; vs. 39.1% in the lower GI group). Underweight status was more common in the hepatobiliary and upper GI patient groups (nearly 50% for each group) than in the lower GI group (30.4%). On the other hand, stunted patients had a higher incidence of complications and a prolonged hospital stay (P=0.003 and P=0.037, respectively), while underweight lower GI patients experienced a prolonged hospital stay (P=0.02). A higher proportion of patients with preoperative anemia than those without preoperative anemia required a blood transfusion (P=0.003). Conclusion: Nutritional assessment is a crucial component of pediatric surgical patient management. Both underweight and wasting statuses were more common among hepatobiliary and upper GI patients. Postoperative complications and a long hospital stay were more common among stunted patients.

• Journal of Trauma and Injury
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• v.34 no.3
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• pp.155-161
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• 2021

Purpose: The coronavirus disease 2019 (COVID-19) pandemic has necessitated a redistribution of resources to meet hospitals' service needs. This study investigated the impact of COVID-19 on a regional trauma center in South Korea. Methods: We retrospectively reviewed cases of polytrauma at a single regional trauma center in South Korea between January 20 and September 30, 2020 (the COVID-19 period) and compared them to cases reported during the same time frame (January 20 to September 30) between 2016 and 2019 (the pre-COVID-19 period). The primary outcome was in-hospital mortality, and secondary outcomes included the number of daily admissions, hospital length of stay (LOS), and intensive care unit (ICU) LOS. Results: The mean number of daily admissions decreased by 15% during the COVID-19 period (4.0±2.0 vs. 4.7±2.2, p=0.010). There was no difference in mechanisms of injury between the two periods. For patients admitted during the COVID-19 period, the hospital LOS was significantly shorter (10 days [interquartile range (IQR) 4-19 days] vs. 16 days [IQR 8-28 days], p<0.001); however, no significant differences in ICU LOS and mortality were found. Conclusions: The observations at Regional Trauma Center, Pusan National University Hospital corroborate anecdotal reports that there has been a decline in the number of patients admitted to hospitals during the COVID-19 period. In addition, patients admitted during the COVID-19 pandemic had a significantly shorter hospital LOS than those admitted before the COVID-19 pandemic. These preliminary data warrant validation in larger, multi-center studies.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.135-144
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• 2021

Purpose : The purpose of this study was to investigate the effect of 2 weeks of backward walking exercise (BWE) on cervical angle and gait parameters in college students with forward head posture. Methods : Fifteen subjects participated in the experiment. All the participants had a craniovertebral angle (CVA) of 55 degrees or less. The purpose of the study was explained to all the subjects prior to participation, and volunteered to take part in the study. A camera capable of taking pictures of the lateral plane was installed at a distance of 1.5 meters from each subject. Images of forward head posture were obtained before and after performing the BWE, and the CVA and craniorotational angle (CRA) were compared pre- versus post exercise. Foot pressure and gait parameters (step length of left and right, stride length, stance of left and right, swing of left and right, step time of left and right, and stride time) were measured using a rehabilitation treadmill. The subjects performed the BWE for 2 weeks. The exercise program consisted of a 5-minute warm-up exercise, 20-minute main exercise, and 5-minute cool-down exercise. In the main exercise, the treadmill speed was set to 2.4 km/h in the first week and 3.4 km/h in the second week. A paired t test was used to compare the CVA and CRA and gait parameters before and after the exercise. Results : Comparison of the CVA and CRA before and after the BWE revealed a significant difference post exercise, with a marked improvement in forward head posture after the exercise (p<.05). Conclusion : Based on the results of this study, the BWE is considered to be an effective exercise for the forward head posture. Also, additional research is needed to shed light on the impact of the BWE on gait parameters.

• The Journal of Korean Physical Therapy
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• v.33 no.2
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• pp.53-61
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• 2021

Purpose: This study examined the impacts of action observational physical training related to stair walking on the stair walking ability and self-efficacy of chronic stroke patients. Methods: This study was conducted on 24 chronic stroke patients, who were assigned randomly to an action observational physical training group (12 persons) and a landscape observation physical training group (12 persons). To the action-observational physical training group, five videos related to stair walking were presented, and after observing them, physical training was carried out. The landscape observation physical training group observed the videos consisting of landscape, where there were no humans and animals, and then underwent physical training. This study measured the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius to examine the muscle activity of the lower limb. A timed up and go and step test was performed to examine the balance ability, and a timed stair test was conducted to examine their stair walking ability. A self-efficacy scale was measured to examine the degree of their confidence of performing stair walking. The assessment was conducted three times in total: pre-, post-, and follow-up surveys. Results: As a result of this study, the action observational physical training group significant improvement after the intervention than in the landscape observation physical training group. Moreover, the follow-up study four weeks after the intervention showed significant improvements in the action observational physical training group (p<0.05). Conclusion: These results show that the action observational physical training had a positive impact on the stair walking ability and self-efficacy of chronic stroke patients.

• Fisheries and Aquatic Sciences
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• v.22 no.6
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• pp.12.1-12.8
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• 2019

Background: Wild fish populations stock is continuously diminishing in the Indo-Ganges river basin, and the population status of most fishes is unidentified. The identification of the population status and the conservation of commercially important and endemic wild fish populations in this region are crucial for the management. The aim of this paper was to identify the population status of Cirrhinus reba, a promising aquaculture but vulnerable species in the Indo-Ganges river basin in Bangladesh. Methods: C. reba samples were collected from four isolated populations of the Brahmaputra (n = 30), the Padma (33), the Karatoya (31), and the Jamuna Rivers (30) in Bangladesh, and the population status was evaluated using morphometric and landmark comparisons. Data were analyzed with the Kruskal-Wallis test, univariate analysis, discriminant function analysis, and the formation of a dendrogram. Results: Three meristic characters (Pectoral fin rays, caudal fin rays, scale in lateral lines), four morphometric characters (head length, pre-orbital length, post-orbital length, maximum body depth), and truss measurement (4-7) were significantly different among the stocks. The step-wise discriminant function analysis retained 15 variables from morphometric and landmark measurements that significantly differentiated the populations based on the constructed DFI and DFII. Discriminate function analysis also showed that 91.2% of the original groups were classified into their correct samples. The cluster analysis of Euclidean distances placed the Jamuna population in one cluster and the Brahmaputra, the Padma, and the Karatoya populations in the second one. Conclusion : Morphological differences among the stock were probably due to different ancestral origin. This is the first report about population status of C. reba in their natural habitat of the Indian subcontinent. Further genetic studies and the evaluation of environmental impact on C. reba populations in Bangladesh are suggested to support our findings.

• The Journal of Korean Association of Computer Education
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• v.22 no.1
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• pp.79-86
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• 2019

This study examines the impact of modular robot programming education on middle school informatics curriculum learning motivation. For this purpose, the experiment was conducted with a experimental group of 25 people and a control group of 25 people, and modular robot programming education and learning motivation test were used as research tools. As a result of processing the results of the learning motivation test paper with the independent sample t-test and the paired t-test, the experimental group had 9.36 points higher learning motivation than the control group and 15.44 points higher than the pre-test. In particular, it significantly affected the improvement of all the sub-components of the learning motivation, and among them, it greatly affected the enhancement of attention, relevance and satisfaction. In conclusion, it can be seen that modular robot programming education has a positive effect on improving students' motivation to learn the informatics curriculum.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.125-131
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• 2018

Some propellants in a liquid rocket engine are burned in the pre-burner of a staged combustion cycle engine, resulting hot gas drives the turbine. The burned gas passing through the turbine is supplied to the combustor at high temperature and pressure. The form of the gas can be fuel rich or oxidizer rich dependent upon the mixture ratio or the engine scheme. When the cycle works at oxidizer-rich condition, the metal pipes composing the engine can be ignited or even exploded by an impact of very a small particle. In this study, we developed the powder combination and processes for an anti-oxidation coating through the analysis of various coating materials.

• Atmosphere
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• v.29 no.3
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• pp.241-255
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• 2019

Bias correction (BC) and quality control (QC) are essential steps for the proper use of satellite observations in data assimilation (DA) system. BC should be calculated over quality controlled observation. And also QC should be performed for bias corrected observation. In the Korea Institute of Atmospheric Prediction Systems (KIAPS) Package for Observation Processing (KPOP), we adopted an adaptive BC method that calculates the BC coefficients with background at the analysis time rather than using static BC coefficients. In this study, we have developed an iterative QC-BC method for Advanced Microwave Sounding Unit-A (AMSU-A) to reduce the negative feedback from the interaction between BC and QC. The new iterative QC-BC is evaluated in the KIAPS 3-dimensional variational (3DVAR) DA cycle for January 2016. The iterative QC-BC method for AMSU-A shows globally significant benefits for error reduction of the temperature. The positive impacts for the temperature were predominant at latitudes of $30^{\circ}{\sim}90^{\circ}$ of both hemispheres. Moreover, the background warm bias across the troposphere is decreased. Even though AMSU-A is mainly designed for atmospheric temperature sounding, the improvement of AMSU-A pre-processing module has a positive impact on the wind component over latitudes of $30^{\circ}S$ near upper-troposphere, respectively. Consequently, the 3-day-forecast-accuracy is improved about 1% for temperature and zonal wind in the troposphere.

• Journal of The Korean Association of Information Education
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• v.23 no.4
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• pp.283-292
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• 2019

In this study, an unplugged education method which focuses on the data visualization training was applied to third grade students of an elementary school and analyzed its impact on enhancing their computational thinking. The analysis was conducted on 60 elementary school teachers and 124 third grade students and the unplugged education program based on the data visualization procedure was developed. The education program developed was carried out with 24 third grade students for 36 hours over six days. The effect of the program applied was analyzed through the pre-to-post comparison performed with perceptive strength test and creativity test in order to examine the enhancement in computational thinking. According to the analysis result, the unplugged education method which focuses on the data visualization training has significant effect on the 'computational perception' and 'creativity' of third grade students.