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Hybrid energy harvesting systems for self-powered sustainable water purification by harnessing ambient energy

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Frontiers of Environmental Science & Engineering 2023年第10期17卷 1-16页

作者： Zhengyang Huo Young jun kim Yuying Chen Tianyang Song Yang Yang Qingbin Yuan Sang Woo kim School of Environment and Natural Resources Renmin University of ChinaBeijing 100872China School of Advanced Materials Science and Engineering Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Institute of Scientific and Technical Information of China Beijing 100038China

The development of self-powered water purification technologies for decentralized applications is crucial for ensuring the provision of drinking water in resource-limited regions. The elimination of the dependence on external energy inputs and the attainment of self-powered status significantly expands the applicability of the treatment system in real-world scenarios. Hybrid energy harvesters, which convert multiple ambient energies simultaneously, show the potential to drive self-powered water purification facilities under fluctuating actual conditions. Here, we propose recent advancements in hybrid energy systems that simultaneously harvest various ambient energies (e.g., photo irradiation, flow kinetic, thermal, and vibration) to drive water purification processes. The mechanisms of various energy harvesters and point-of-use water purification treatments are first outlined. Then we summarize the hybrid energy harvesters that can drive water purification treatment. These hybrid energy harvesters are based on the mechanisms of mechanical and photovoltaic, mechanical and thermal, and thermal and photovoltaic effects. This review provides a comprehensive understanding of the potential for advancing beyond the current state-of-the-art of hybrid energy harvester-driven water treatment processes. Future endeavors should focus on improving catalyst efficiency and developing sustainable hybrid energy harvesters to drive self-powered treatments under unstable conditions (e.g., fluctuating temperatures and humidity).

关键词： Piezocatalysis Solar energy Waste heat Decentralized water treatment Point-of-use Nanogenerator

Controlling a lithium surface with an alkyl halide nucleophile exchange

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Journal of Energy Chemistry 2021年第11期30卷 617-626,I0015页

作者： jung-Hun Lee Thuy Hoai Linh Vuong Soo Min Hwang Jae-Hun kim Young-jun kim SKKU Advanced Institute of Nanotechnology(SAINT) Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Nano Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea School of Materials Science and Engineering Kookmin UniversitySeoul 02707Republic of Korea

Despite its high theoretical energy density, lithium metal faces huge challenges in its implementation as an anode for Li secondary batteries because of its uncontrollable dendritic growth and large volume change during plating/stripping processes. These geometric changes cause degradation in a cell’s cycle life and performance and can lead to short-circuits and explosions. Here, we report a new approach to producing a LiF-rich phase on the lithium anode surface by employing a “bi-phase” separator. We fabricated it by coating polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) onto a cellulose separator. The coverage of coating was adjusted by varying its concentration in the coating solution. The combination of cellulose and PVDF-HFP produced a LiF-rich solid-electrolyte interphase layer on the Li metal surface via an alkyl halide nucleophile exchange in contact with the bi-phase separator during plating. Symmetric cell tests show that the bi-phase separator extends the cycle life by more than 300 h, with overpotentials of less than 100 mV under plating/stripping at 2 mA cm^(−2) for a capacity of 2 mAh cm^(−2). The formation mechanism of the LiF-rich phase is suggested from spectroscopic analyses.

关键词： Li metal anode PVDF-HFP Cellulose LiF Phase inversion

Endoscopic mucosal resection of early gastric cancer: Experiences in Korea

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World Journal of Gastroenterology 2007年第27期13卷 3657-3661页

作者： jun Haeng Lee Jae J kim Department of Medicine Samsung Medical Center Sungkyunkwan University School of Medicine Seoul South Korea

Endoscopic mucosal resection （EMR） has been established as one of the treatment options for early gastric cancer （EGC）. However, there are many uncertain areas such as indications of EIR, best treatment methods, management of complications and follow-up methods after the procedure. Host studies on this topic have been carried out by researchers in Japan. In Korea, gastric cancer is the most common malignant disease, and the second leading cause of cancer death. In these days, EIR for EGC is widely performed in many centers in Korea. In this review, we will provide an overview of the bechniques and outcomes of EIR in Korea.

关键词： Endoscopic mucosal resection Early gastric cancer Indication Complication Prognosis

Obturator hernia-a rare etiology of lateral thigh pain:A case report

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World Journal of Clinical Cases 2021年第34期9卷 10728-10732页

作者： jun Young kim Min Cheol Chang Department of Physical Medicine and Rehabilitation College of MedicineYeungnam UniversityTaegu 705-717South Korea

BACKGROUND Lateral thigh pain is a common complaint in patients visiting a pain ***,we describe the case of a patient with lateral thigh pain caused by an obturator *** SUMMARY An 83-year-old woman visited the emergency room with suddenly aggravated right lateral thigh *** resonance imaging of the thigh revealed no abnormal findings in the lateral thigh ***,an obturator hernia between the pectineus and obturator externus muscles was observed by *** computed tomography revealed a herniated small bowel with an incarceration point at the right obturator canal and a dilated loop of the small bowel *** of the right inguinal region revealed a distended bowel loop in the right pectineus *** Our report provides clinicians with information that an obturator hernia can cause lateral thigh pain.

关键词： Obturator hernia Pain Magnetic resonance image Computed tomography Ultrasonography Case report

Understanding secondary phase inclusion and composition variations in the microstructure design of n-type Bi_(2)Te_(3) alloys via selective dissolution of KCl

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Journal of Advanced Ceramics 2023年第12期12卷 2360-2370页

作者： Gwang Min Park Seunghyeok Lee jun-Yun Kang Seung-Hyub Baek Heesuk kim Jin-Sang kim Seong Keun kim KU-KIST Graduate School of Converging Science and Technology Korea UniversitySeoul 02841Republic of Korea Electronic Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Department of Materials Science and Chemical Engineering Hanyang UniversityAnsan 15588Republic of Korea Ferrous Alloy Department Korea Institute of Materials ScienceChangwon 51508Republic of Korea Soft Hybrid Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju 55324Republic of Korea

This study investigated the effects of KCl treatment on microstructure and thermoelectric properties of n-type Bi_(2)Te_(2.7)Se_(0.3)(BTS)thermoelectric *** innovative KCl treatment was originally intended to introduce nanopores through selective dissolution of KCl from a mixture of thermoelectric materials and ***,it unexpectedly induced substantial variations in material composition and microstructure during the subsequent spark plasma sintering(SPS)*** groups adsorbed on the powder surface during the dissolution resulted in the emergence of a Bi_(2)TeO_(5) secondary phase within the BTS matrix after the SPS process at 450℃.The concentration of Bi_(2)TeO_(5) increased with an increase in the KCl ***,a remarkable grain growth occurred at low KCl concentrations,likely due to the liquid-phase formation in a Te-rich composition during ***,excessive Bi_(2)TeO_(5) at higher KCl concentrations hindered grain *** variations in the microstructure had complex effects on electrical properties:The TeBi antisite defects increased the electron concentration,and Bi_(2)TeO_(5) reduced electron ***,the lattice thermal conductivity decreased due to the presence of Bi_(2)TeO_(5),from 0.8 W·m^(−1)·K^(−1) at 298 K for the pristine BTS to 0.6 W·m^(−1)·K^(−1) at 298 K for BTS treated with 1 wt%*** insights allowed precise adjustments of the electrical and thermal conductivities,leading to an enhancement in the maximum value of figure-of-merit(ZT)from 0.76 to 0.96 through the selective dissolution of KCl *** believe that our observations potentially enable advances in thermoelectric materials by engineering microstructures.

关键词： thermoelectric materials Bi_(2)Te_(3) Bi_(2)TeO_(5) grain growth n-type KCl

BIOCOMPATIBILITY OF A PDMS-COATED MICRO-DEVICE:BLADDER VOLUME MONITORING SENSOR

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Chinese Journal of Polymer Science 2012年第2期30卷 242-249页

作者： Dong Sup Lee Su Jin kim jun Ho Sohn In Gul kim Sae Woong kim Dong Wan Sohn Jong Hyun kim Bumkyoo Choi Department of Urology St.Vincent's HospitalCollege of Medicinethe Catholic University of KoreaSuwonKorea Department of Urology Seoul St.Mary's HospitalCollege of Medicinethe Catholic University of KoreaSeoulKorea Department of Urology Yeouido St.Mary's HospitalCollege of Medicinethe Catholic University of KoreaSeoulKorea Department of Mechanical Engineering Sogang UniversitySeoulKorea

We evaluated the biocompatibility of a dimethylpolysiloxane-coated micro-device which had been designed for monitoring real-time bladder volume in previous studies. The extract assay with dimethylpolysiloxane which had been used for coating the micro-device to measure the bladder volume was performed as an in vitro cytotoxicity test. For in vivo biocompatibility testing, the inflammatory responses around the implantation site of the micro-device in subcutaneous tissue of rat were assessed by light microscope with H＆E stain and fluorescence microscope with ED1 stain and von Willebrand factor stain. The averages of cell viability in dimethylpolysiloxane group were 84.6% and 82.3% at 24 h and 72 h incubation, respectively. The qualitative evaluations with light and fluorescence microscope revealed that the inflammatory changes peaked during 2 weeks but almost disappeared at 4 weeks after implantation of devices. The quantitative evaluations for granulation layer formation and neovascularization showed that the thickness of the layer in dimethylpolysiloxane group peaked during 2 weeks but it came to be stabilized at 4 weeks as thin as at 2 weeks in control group, and the frequency of neovascularization was higher in dimethylpolysiloxane group than in control group but it was not increased with time. The dimethylpolysiloxane-coated micro-device is thought be a reliable bio-medical device.

关键词： Dimethylpolysiloxane Devices Biocompatibility testing.

Surface plasmon enhancement of photoluminescence in photo-chemically synthesized graphene quantum dot and Au nanosphere

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Nano Research 2016年第6期9卷 1866-1875页

作者： Byeongho Park Sun jun kim Ji Soo Sohn Min Sik Nam Shinill Kang Seong Chan jun School of Mechanical Engineering Yonsei University 50 Yonsei-ro Seodaemun-gu Seou1120-749 Republic of Korea

Graphene quantum dots （GQDs） are promising candidates for potential applications such as novel optoelectronic devices and bio-imaging. However, insufficient light absorption to exhibit their intriguing characteristics. The strong confinement of light caused by the Au nanoparticles as an antenna can considerably boost the light absorption. With the assistance of ultraviolet irradiation, we prepared bluish-green luminescent nanospheres by the hybridiza- tion of GQD and Au nanoparticles （GQD/Au）. These nanospheres showed a photoluminescence quantum yield of up to 26.9%. The GQD/Au nanospheres were synthesized using a solution of GQDs and HAuC14 by a photochemical method with the reduction of GQDs and the formation of metallic Au. The GQDs and Au nanopartides self-assembled and aggregated into nanospheres via aurophilicity and hydrogen bonding interactions. The average size of the GQD/Au nanospheres was found to be in the range of 150-170 nm, which is much larger than that of the pristine GQDs （4-7 nm）. The GQD/Au nanospheres exhibited an absorption band at 541 nm, which indicates the presence of Au in the nanospheres. The typical absorbance features of GQDs were observed near 236 and 303 nrn. The photoluminescence characteristics were investigated using the excitation and emission spectra. The GQD/Au nanospheres exhibited two emission peaks at 468 and 529 nm in the visible range. The green fluorescent peak located at 529 nm was newly generated by the hybridization. The GQD/Au nanospheres showed an emission efficiency which was two times more than that of the intrinsic GQDs. The reason for this increase was the surface plasmon resonance from the Au particles, which improved the fluorescence property of the resulting nanospheres. These nanospheres can be perceived as outstanding candidates for applications such as displays, optoelectronic devices, and imaging of the biological samples with high emission intensity.

关键词： graphene quantum dot gold nanosphere photoluminescence UV irradiation

Virtual Reality-Based Random Dot Kinematogram

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Computers, Materials & Continua 2021年第9期68卷 4205-4213页

作者： jun Ma Hyo-jung kim Ji-Soo kim Eek-Sung Lee Min Hong Department of Software Convergence Soonchunhyang UniversityAsan31538Korea Research Administration Team Seoul National University Bundang HospitalSeongnam13620Korea Dizziness Center Clinical Neuroscience CenterDepartment of NeurologySeoul National University Bundang HospitalSeongnam13620Korea Department of Neurology Seoul National University College of MedicineSeoul03080Korea Department of Neurology College of MedicineSoonchunhyang UniversityBucheon14584Korea Department of Computer Software Engineering Soonchunhyang UniversityAsan31538Korea

This research implements a random dot kinematogram(RDK)using virtual reality(VR)and analyzes the results based on normal *** motion perception is one of visual functions localized to a specific cortical area,the human motion perception area(human analogue for the middle temporal/middle superior temporal area)located in the parieto–occipito–temporal junction of the human *** RDK measures visual motion perception *** stimuli in conventional RDK methods are presented using a monitor screen,so these devices require a spacious dark room for installation and ***,VR technology has been implemented in different medical *** test method proposed in this study include a VR-based RDK that can independently measure human motion perception abilities without any spatial constraints via a VR head-mounted ***,the VR-based RDK was implemented,and the visual perception abilities of the normal subjects were measured based on varying *** both screen-and VR-based RDK tests,the easier the stimulus is,the higher the correct answer rate and the shorter the reaction *** significant differences in coherence thresholds were observed between the two test *** VRbased RDK proposed in this study can be used as a diagnosis tool for visual motion perception and neurodegenerative disorders affecting the posterior region of the brain.

关键词： Random dot kinematogram virtual reality visual psychophysics diagnostic device

Intrauterine midgut volvulus without malrotation:Diagnosis from the 'coffee bean sign'

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World Journal of Gastroenterology 2008年第9期14卷 1456-1458页

作者： jun Seok Park Seong Jae Cha Beom Gyu kim Yong Seok kim Yoo Shin Choi In Taik Chang Gwang jun kim Woo Seok Lee Gi Hyeon kim Department of Surgery College of MedicineChung-Ang University Seoul 156-755Korea Department of Obstetrics and Gynecology College of Medicine Chung-Ang UniversityKorea Department of Radiology College of Medicine Chung-Ang University Seoul 156-755Korea

Fetal midgut volvulus is quite rare, and most cases are associated with abnormalities of intestinal rotation or fixation. We report a case of midgut volvulus without malrotation, associated with a meconium pellet, during the gestation period. This 2.79 kg, 33-wk infant was born via a spontaneous vaginal delivery caused by preterm labor. Prenatal ultrasound showed dilated bowel loops with the appearance of a 'coffee bean sign'. This patient had an unusual presentation with a distended abdomen showing skin discoloration. An emergency laparotomy revealed a midgut volvulus and a twisted small bowel, caused by complicated meconium ileus. Such nonspecific prenatal radiological signs and a low index of suspicion of a volvulus during gestation might delay appropriate surgical management and result in ischemic necrosis of the bowel. Preterm labor, specific prenatal sonographic findings (for example, the coffee bean sign) and bluish discoloration of the abdominal wall could suggest intrauterine midgut volvulus requiring prompt surgical intervention.

关键词： Midgut volvulus Coffee bean sign Meconium ileus