Search

Objectives In this study, the removal efficiency of micropollutants in the biological activated carbon (BAC) process was investigated, and a method for improving the removal efficiency of micropollutants in the BAC process of water treatment plants was proposed. Methods Dibromo-methylparaben (Br2-MP) was selected as the target micropollutant. Batch and lab-scale column experiments were conducted to evaluate the removal efficiencies of Br2-MP in the conventional BAC process and the BAC with enhanced biofilm properties by the addition of phosphorus (P) and hydrogen peroxide (H2O2). Biodegradation kinetics were evaluated using results from batch and lab scale column experiments. Results and Discussion As a result of comparing the removal efficiency of Br2-MP in a batch experiment with the same biomass concentrations (2.0±0.2×107 cells), the biodegradation rate constant (kbio) of the enhanced BAC process was found to be 1.2 times higher than that of the conventional BAC process due to its higher biological activity (enhanced BAC: 3.4±0.3 mg·C/g·hr, conventional BAC: 2.9±0.4 mg·C/g·hr). Comparison of removal efficiencies of Br2-MP in batch experiments with the same wet weight of BAC (1 g) showed that the biodegradation rate constant (kbio) of the enhanced BAC process was 1.9 times higher than that of conventional BAC process due to higher biomass (enhanced BAC: 3.5±0.4 µg·ATP/g·GAC, conventional BAC: 2.3±0.2 µg·ATP/g·GAC). Through the batch experiments, the enhanced BAC process was efficient in removing Br2-MP via increasing both biomass concentrations and activity of attached microorganisms. Lab-scale column experiments conducted under different water temperatures (5 and 25℃) and empty bed contact time (EBCT: 5-40 min) conditions showed higher removal efficiency of Br2-MP in the enhanced BAC process than the conventional BAC process throughout the entire period of operation. In particular, the removal efficiency of Br2-MP between the enhanced and conventional BAC processes showed significant differences at low temperature (5℃) and short EBCT (5 min). At 5℃ and 25℃, the kbio of the conventional BAC process was 0.0229 min-1 and 0.0612 min-1, respectively, and the kbio of the enhanced BAC process was 0.0470 min-1 and 0.1421 min-1, respectively, These results showed that the enhanced BAC process had two times higher biodegradability of Br2-MP than the conventional BAC process. These results showed a similar trend to the results from the batch experiment. In an experiments simulating the impact of frequent EBCT changes during summer, the enhanced BAC process maintained a relatively stable removal efficiency of Br2-MP compared to the conventional BAC process. Conclusion The enhanced BAC process showed superior biodegradation of micropollutant compared to the conventional BAC process. Considering economic costs (e.g., costs of adding phosphate and hydrogen peroxide) and water quality, it appears to be an efficient alternative to operate the enhanced BAC process intermittently, limited to cases where EBCT is shortened, such as summer, or when water temperature is low, such as in winter.

In this review, we introduce recently developed plasma-based approaches for depositing and treating piezoelectric nanoparticles (NPs) and piezoelectric polymer films for nanogenerator (NG) and sensor applications. We also present the properties and an overview of recently synthesized or modified piezoelectric materials on piezoelectric polymers to highlight the existing challenges and future directions of plasma methods under vacuum, low pressure, and ambient air conditions. The various plasma processes involved in piezoelectric NGs and sensors, including plasma-based vapor deposition, dielectric barrier discharge, and surface modification, are introduced and summarized for controlling various surface properties (etching, roughening, crosslinking, functionalization, and crystallinity).

Objectives The objective of this study is to investigate characteristics about removal of dissolved organic matter (DOM) and its fraction for improving operation efficiency in an advanced water treatment plant. Methods The monitoring of water quality was conducted at five processes such as raw water, pre-oxidation, after sedimentation, post-ozonation, after biological activated carbon (BAC) from July 2020 to August 2021 in advanced water treatment process (AWTP) supplying 180,000m3/day. The concentration of DOC (dissolved organic carbon) and number of algae were monitored and LC-OCD was used to fractionate DOC to four species, biopolymer (BP), humic substance (HS), building blocks (BB), and low molecular weights (LMWs). Results and Discussion The characteristics of raw water showed that the concentration of DOC and the number of algae increased with an increase in water temperature. The portion of BP and HS significantly increased at low and high water temperature, respectively, while BB and LMWs maintained the similar portion. The removal efficiency of DOC in the AWTP was achieved at 59% with each species of BP, HS, BB, and LMWs obtaining removal efficiency of 87%, 65%, 26%, and 52%, respectively. Coagulation/sedimentation/filtration showed removal efficiency of 84%, 56%, 20%, and 18% for BP, HS, BB, and LMWs, respectively, corresponding to their molecular weight. The effect of post-ozonation would be negligible except for BP. In BAC, removal efficiency of 49% and 12% were obtained for LMWs and BB (low molecular weight, respectively. As a result, the BP portion significantly decreased due to high removal efficiency, while BB portion was increased in the final treated water compared to raw water. Conclusion Most of DOM was removed in coagulation/sedimentation/filtration and BAC, whereas oxidation process such as pre-chlorination, pre-ozonation and post-oxidation did not have an effect on DOM removal. In coagulation/sedimentation/filtration, 84% and 54% of the BP and HS were removed, while BAC removed 49% and 12% of LMWs and BB, respectively. It has been recommended to improve the removal efficiency of BB, which obtained the lowest removal efficiency in AWTP, and to enhance the removal efficiency of LMWs in BAC to inhibit microbial regrowth in the distribution system.

Purpose To measure changes in health knowledge, health attitudes, and health promotion behaviors of the elderly in rural communities after using the Story Telling Problem Based Learning program facilitated by students in a nursing course. Methods A quasi-experimental study using a non-equivalent control group: 72 students sampled from the nursing discipline were divided into experimental (n=36) and control groups (n=36). The ST-PBL program was provided to the older rural people in the experimental group for six weeks. Results Data were analyzed using the SPSS/WIN 21.0. After the application of the ST-PBL program, the participants in the experimental group showed a significant increase in health knowledge and health promotion behavior. Conclusion The participants in the experimental group demonstrated positive changes in health knowledge, health attitudes, and health promotion behaviours. The use of an approach such as the ST-PBL program can promote uptake of self-care behaviors within the elderly with chronic diseases living in rural areas.

Objectives:The correlation between the organic material removal ability of the enhanced BAC process injected by the phosphate (PO4-P) and/or hydrogen peroxide (H2O2) and attached bacterial community was evaluated. Methods:As pilot plant for the purification of raw water downstream of Nakdong river, 4 acrylic columns with an inner diameter of 20 cm and a height of 250 cm were operated at an empty bed contact time of 20 minutes. The four BAC columns are as followed; conventional BAC (control-BAC), enhanced BAC with phosphorus (PO4-P+BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), and enhanced BAC with phosphorus and hydrogen peroxide (PO4-P+H2O2+BAC). 0.01 mg/L of PO4-P and 1 mg/L of H2O2 were added in influent in the enhanced BAC, respectively. After 18 months of operation, activated carbon was collected from the top of each BAC column and 16S rRNA amplicon sequence analysis was performed. Results and Discussion:The long-term addition of PO4-P and H2O2 contributes the increase of biomass and activity of attached bacteria, respectively. In the attached bacterial community of conventional and enhanced process, Proteobacteria phylum is the most dominant specie and both α-Proteobacteria class and β-Proteobacteria class are also highly present. Each enhanced BAC exhibits very high bacterial community similarity based on the composition of various genera but it is completely different with conventional BAC. In particular, Bradyrhizobium, Sphingomonas, Methylobacterium, Sphingobium, Belnapia, Burkholderia, Polaromonas, and Desulfuromonas, which have excellent metabolism functions for a wide range of organic substrates, are highly dominated in the enhanced BAC process. The concentration of Biodegradable Dissolved Organic Carbon (BDOC) is obtained close to 0.15 mg/L for conventional BAC and less than 0.15 mg/L for enhanced BAC process, respectively. In general, the higher BDOC concentration can result in reducing biostability in water supply and distribution system when the residual chlorine concentration does not meet requirements. As result, less than 0.15 mg/L BDOC accomplished by PO4-P and H2O2 enhances the biostability. Conclusions:Compared to the conventional BAC process, the biomass and activity of attached bacteria and the ratio of the organization composition of the bacteria insides (genus) are considerably higher in the enhanced BAC process. These results achieve higher water quality and improve biostability.

Objectives:The purpose of this study was to suggest a more efficient operation condition for the BAC(biological activated carbon) process by evaluating the change in the concentration of biopolymers in the effluent of the BAC process and the head loss of the BAC filter layer according to phosphate (PO4-P) and hydrogen peroxide (H2O2) input. Methods:During the experiment period (Feb. to Aug. 2020), the O3 dosage was fixed at 1 mg･O3/mg･DOC. Four columns with an inner diameter of 20 cm and a height of 250 cm were prepared. Empty bed contact time (EBCT) was fixed at 20 minutes and backwash was performed once a week. The four BAC columns are conventional BAC(control-BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), enhanced BAC with phosphate (PO4-P+BAC), and enhanced BAC with phosphate and hydrogen peroxide together (PO4-P+H2O2+BAC). In the case of enhanced BAC with PO4-P added, PO4-P was added with a concentration of 0.010 mg/L in the influent, and in BAC with H2O2, H2O2 was added with a concentration of 1 mg/L to the influent. Results and Discussion:According to the change of water temperature, the average head loss in control-BAC was 4.4 (25~28℃)~7.7 cm(8~12℃). In addition, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC were 3.9~5.8 cm, 2.5~3.5 cm, and 2.6~3.5 cm, respectively. The head loss was reduced by the input of PO4-P and H2O2. During the low water temperature period, in control-BAC, the effluent biopolymers (BP) concentration was higher than the influent concentration, indicating that a large amount of EPS (extracellular polymeric substances) was produced and released from the attached biofilm. In PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC processes, the BP concentration ratio (Cout/Cin) was about 36~57% lower than that of the control-BAC during the low water temperature period. The BP concentration ratio was high when the water temperature (8~12℃) was low, and the BP concentration ratio gradually decreased as the water temperature increased. These results were very similar to those of the head loss change in the control-BAC process and the enhanced BAC process, and the BP concentration ratio and the head loss showed a very high correlation (r2=0.82~0.87). To evaluate the stability of the biofilm during the operation period, the total cell counts (TCC) in BAC treated waters were investigated. In control-BAC, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC process, the average TCC was 46.8×106 cells, 30.3×106 cells, 21.8×106 cells, and 18.8×106 cells, respectively. Compared to the control-BAC, it was found to be 35~60% lower in the enhanced BAC processes. In addition, live cell count (LCC) ratio (LCC/TCC) was 0.84~0.89 in the enhanced BAC processes compared to 0.53 in the control-BAC. These results indicate that the biofilm stability of the enhanced BAC processes is higher than that of control-BAC. Conclusions:During the experiment, compared to the conventional BAC process, the enhanced BAC processes in which PO4-P and H2O2 were added showed a clear effect of reducing the head loss. In particular, the effect of reducing the head loss was higher when H2O2 was added than when PO4-P was added. A rapid head loss increase occurred in the conventional BAC process compared to the enhanced BAC processes in the low water temperature season is the result of the production of large amounts of EPS in the attached biofilm. The input of PO4-P or H2O2 reduces the head loss by improving the stability of the attached biofilm and reducing EPS production.

Objectives: In this study, we compared the properties of the attached biofilm with the ability to remove biodegradable dissolved organic carbon (BDOC) in the conventional BAC (biologically activated carbon) process and the enhanced BAC process with phosphorus and hydrogen peroxide added. The enhanced BAC process was designed to increase the operational efficiency of the old O3/BAC process by evaluating the applicability of large-scale water treatment facilities located downstream of the Nakdong River. Method: The granular activated carbon which was used for 2 years in the O3/BAC process in the water treatment plant located downstream of the Nakdong River was used in this experiment. During the experiment period, the ozone dosage was fixed at 1 mg･O3/mg･DOC. Four acrylic columns with an inner diameter of 20 cm and a height of 250 cm were prepared. Empty bed contact time (EBCT) was fixed at 20 minutes and backwash was performed once a week. The four BAC columns are conventional BAC (control-BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), enhanced BAC with phosphorus (PO4-P+BAC), and enhanced BAC with phosphorus and hydrogen peroxide together (PO4-P+H2O2+BAC). In the case of enhanced BAC with PO4-P added, PO4-P was added with a concentration of 0.010 mg/L in the influent, and in BAC with H2O2, H2O2 was added with a concentration of 1 mg/L to the influent. Results and Discussion: As a result of evaluating the recovery ability of the damaged biofilm, there was no difference in the biomass recovery rate in the H2O2+BAC compared to the control-BAC, but the biomass was rapidly recovered in the PO4-P+BAC. Considered the biomass and activity of the attached biofilm after the ability to remove organic substances reached a steady state, the biomass and activity in the entire filter layer of the PO4-P+BAC increased by 20 to 86% and 7 to 14%, respectively, compared to the control-BAC. In the H2O2+BAC, only the activity increased by 3~11% and In the PO4-P+H2O2+BAC, biomass and activity were high, about 27 to 87% and 8 to 20%, respectively. In the H2O2+BAC, the BDOC removal rate was higher than the control-BAC by 20%, and in the PO4-P+BAC, the BDOC removal rate increased by more than 100%. Detached total cell counts (TCC) in the control-BAC effluent was 41.7×106 cells/mL on average, and in the H2O2+BAC, TCC was reduced by 49% compared to control-BAC and decreased by 67% and 85% in the PO4-P+BAC and the PO4-P+H2O2+BAC effluent. It means the biofilm of the enhanced BAC process was evaluated more stably than control-BAC. Conclusions: The biomass and the activity of the attached biofilm in the BAC process, are one of the important factors that determine the ability to remove contaminants. The enhanced BAC process combined PO4-P with H2O2 was very effective in enhancing the biomass and the activity of the attached biofilm. The PO4-P added enhanced BAC was more effective in terms of biomass, BDOC removal rate, and biofilm stability than the H2O2 added enhanced BAC. The enhanced BAC combined PO4-P with H2O2 showed a slight increase additional efficiency compared to the PO4-P added BAC.

Objectives The purpose of this study was to verify the effectiveness of the CPBL (Creative Problem Based Learning) model on nursing students’ communication skills, resolving (problem-solving) skills and empathy ability. Methodology A quasi-experimental study using a non-equivalent control group: 72 students sampled from the nursing discipline were divided into experimental (n=36) and control groups (n-36). The CPBL program offering was provided to the experimental group for 8 weeks. Data were analyzed with the SPSS /WIN 21.0 program. Results After the application of CPBL model the experimental group showed a significant increase in their abilities in communication, resolving and empathy. Conclusion Stimulus material in CPBL model led to learning outcomes consistent with improved nursing students’ ability in communication, resolving and empathy.

Despite the clinical relevance of necrotizing enterocolitis (NEC), it remains difficult to predict which preterm infants are more likely to develop NEC. Contrary to the neonatal risk factors for the development of NEC, little information is available regarding maternal (prenatal) risk factors. We aimed to identify maternal risk factors associated with the subsequent development of NEC in very preterm infants and to determine whether the placental inflammatory lesions were related to the NEC. Methods: This retrospective cohort study examined newborns born at

Purpose Though it is very important obtaining exact data about patients’ voiding patterns for managing voiding dysfunction, actual practice is very difficult and cumbersome. In this study, data about urination time and interval measured by smart band device on patients’ wrist were collected and analyzed to resolve the clinical arguments about the efficacy of voiding diary. By developing a smart band based algorithm for recognition of complex and serial pattern of motion, this study aimed to explore the feasibility of measurement the urination time and intervals for voiding dysfunction management. Methods We designed a device capable of recognizing urination time and intervals based on specific postures of the patient and consistent changes in posture. These motion data were obtained by a smart band worn on the wrist. An algorithm that recognizes the repetitive and common 3-step behavior for urination (forward movement, urination, backward movement) was devised based on the movement and tilt angle data collected from a 3-axis accelerometer. The sequence of body movements during voiding has consistent temporal characteristics, so we used a recurrent neural network and long short-term memory based framework to analyze the sequential data and to recognize urination time. Real-time data were acquired from the smart band, and for data corresponding to a certain duration, the value of the signals was calculated and then compared with the set analysis model to calculate the time of urination. A comparative study was conducted between real voiding and device-detected voiding to assess the performance of the proposed recognition technology. Results The accuracy of the algorithm was calculated based on clinical guidelines established by urologists. The accuracy of this detecting device was high (up to 94.2%), proving the robustness of the proposed algorithm. Conclusions This urination behavior recognition technology showed high accuracy and could be applied in clinical settings to characterize patients’ voiding patterns. As wearable devices are developed and generalized, algorithms detecting consistent sequential body movement patterns reflecting specific physiologic behavior might be a new methodology for studying human physiologic behavior.

ObjectivesAn official guideline must be prepared for legalizing the doctor-patient telemedicine system based on the evaluations of the ongoing telemedicine demonstration project performed by the Korean government. In this study, critical items of the Korean telemedicine guideline are suggested based on the guidelines of developed countries.MethodsTo investigate the telemedicine guidelines of developed countries, a keyword of 'telemedicine guidelines' was used for Google search to find out US, Australian, and Japanese guidelines. The common items included in two or more of the followings were screened: US Core Operational Guidelines for Telehealth Services Involving Provider-Patient Interactions, the Australian New South Wales (NSW) Agency for Clinical Innovation Guidelines for the use of Telehealth for Clinical and Non Clinical Settings in NSW, and the Japanese Guidelines for the practice of home telemedicine.ResultsA total of 22 common items of the following four domains, which could be used for the Korean guideline were screened: the common features in overall considerations (6 items), the common features in clinical considerations (6 items), the common features in technical considerations (5 items), and the common features in privacy considerations (5 items). These 22 items were suggested as the critical items of the Korean telemedicine guideline.ConclusionsThe screened 22 items of the telemedicine guideline must be further organized for details. Additional studies and professional opinions on the telemedicine cases and on the guidelines of developed countries are required to establish the Korean guideline in the near future.

This study investigated on the effects of adding mechanically deboned chicken meat (MDCM) hydrolysates on the quality properties of imitation fish paste (IFP) during storage. IFP was prepared from Alaska Pollack, spent laying hens surimi and protein hydrolysates which were enzymatically extracted from MDCM. The study was designed as a 3×4 factorial design with three MDCM hydrolysate content groups (0%, 0.4%, and 0.8%) and four storage times (0, 2, 4, and 6 weeks). Addition of MDCM hydrolysates increased crude fat content but lowered water content (p

ObjectivesTo manage a patient's blood pressure and recovery, and to reduce unnecessary hospital visits after heart surgery, we developed and established a telecare service.MethodsWe established and test-operated the system that enabled biometric data to be measured and monitored at home, and directed connections to the video consultation with monitoring personnel and medical staff when abnormal symptoms were detected.ResultsAs a result of using the telecare service with patients discharged from the hospital after undergoing heart surgery, the patients were mostly satisfied with the service and use of the equipment, and some patients wanted to actually receive the service continuously along with a device which could be more easily used.ConclusionsTelecare services are greatly needed for patients discharged after heart surgery for a certain period of time. A model should be developed which provides devices necessary for each disease in package form and customizes the content and services in one package.