야간 악천후 시 발광형 차선 시인성 평가

박원일(Wonil Park),김용석(Yongseok Kim),박기수(Kisoo Park),이석기(Sukki Lee) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.12

야간 악천후의 도로 환경은 운전자가 안전한 주행환경을 유지하기에 많은 시각적 제약이 있다. 특히, 주행 차선의 시인성이 저하되면 차량이 차로를 이탈하고 교통사고가 발생하기도 한다. 일반적으로 차선에 유리알 비드(Bead)를 살포한 후 재귀반사 효과를 통해 차선의 시인성을 확보하고 있으나, 야간 및 악천후 시에는 효과가 적고 일정 시간이 경과하면 그 성능은 급격하게 저하된다. 따라서, 국내외에서는 야간 악천후 시 차선의 시인성을 확보하기 위해 발광형 차선을 개발하고 있다. 그러나 이에 대한 검증은 부족한 실정이며 특히, 운전자에게 가장 위험한 환경인 야간 악천후 환경에서의 성능 검증은 거의 전무하다. 따라서, 본 연구에서는 실규모의 야간 악천후 환경을 구현하고 다양한 외부 조명 조건에서 일반 차선 대비 발광형 차선의 성능을 휘도 값 비교를 통해 검증 하였다. 그 결과로 백색차선과 발광형 차선의 휘도 차이는 최대 4.65cd/㎡를 보였다. 또한, 발광형 차선은 백색차선 대비 악천후 시 휘도 감소율이 낮았으며, 외부조명이 전혀 없는 경우에도 일정 휘도 값을 보여 종합적으로 야간 악천후 시 백색차선 대비 높은 휘도 성능을 보였다. Driving at nighttime is a difficult task for drivers mainly due to visual restrictions. In particular, higher accident risk at nighttime compared to daytime explains this difficulty. Especially, a lowered visibility of pavement markings leads to run-off-the road accidents. A conventional pavement marking utilizing a glass bead with the retro-reflecting mechanism has been widely used in practice. However, the loss of a considerable portion of glass beads with time diminishes the visibility dramatically leading to serious problems. Recently, luminescent lane marking has been under development to overcome the problems associated with glass bead markings by fertilizing the physical property of the luminescent. However, the validation of visibility robustness of a luminescent lane under adverse weather conditions needs to be performed to derive its superiority over conventional markings. To this end, this study simulated real scale weather proving ground and tested the performance of a luminescent lane by measuring the luminance. The results suggested that the luminance difference between conventional and luminescent markings was 4.65 cd/㎡. In addition, luminescent markings showed higher performance in terms of reduction rate due to adverse weather. Under worst-case scenarios such as roads without lightings and vehicle headlights, luminescent markings provided higher luminance than pavement. Moreover, no difference was observed between conventional lane marking and a pavement background. It means that the safety margin was attained in the luminescent marking condition even under worst-case road-illuminated conditions.

Luminescent-center tuning for Ba₆Ca₃YAlSi₆O₂₄:Ce³⁺, Na⁺ orthosilicate phosphors

Yang, Sungjun,Shin, Tae Joo,Park, Sangmoon Elsevier 2019 Journal of alloys and compounds Vol.777 No.-

<P><B>Abstract</B></P> <P>Ce<SUP>3+</SUP> ion-doped Ba<SUB>6</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> phosphors with a charge-compensating Na<SUP>+</SUP> ion were prepared using a solid-state reaction. Ba<SUB>6</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> was structurally characterized using synchrotron X-ray powder diffraction. The emission wavelengths of Ce<SUP>3+</SUP> in different Ba<SUP>2+</SUP> and Ca<SUP>2+</SUP> sites with the distortion index of polyhedrons in the host lattice were calculated. The photoluminescence excitation and emission spectra of the Ce<SUP>3+</SUP>-activated phosphors were site-selectively monitored; furthermore, the emission quenching as a function of Ce<SUP>3+</SUP> content in the Ba<SUB>6-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> and Ba<SUB>6</SUB>Ca<SUB>3-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> (x = 0.01–0.4) was clearly distinguished at relatively high concentrations of the activator. The Gaussian components of the phosphors were exploited by using the Ce<SUP>3+</SUP> ion sites in the host lattice; in addition, the one and two luminescent centers for the Ba<SUB>6-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> and Ba<SUB>6</SUB>Ca<SUB>3-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> phosphors, respectively, were identified. The sites of the luminescent centers for the calculated Ba<SUB>6</SUB>Ca<SUB>3-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> composition was selectively tuned as the (BaCa)<SUB>9-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> lattice structure.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ba<SUB>6</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB>:Ce<SUP>3+</SUP>, Na<SUP>+</SUP> phosphors were prepared. </LI> <LI> New phase of the Ba<SUB>6</SUB>Ca<SUB>3</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> host was characterized. </LI> <LI> Single and double luminescent centers were identified. </LI> <LI> Ba<SUB>6</SUB>Ca<SUB>3-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB> was tuned as (BaCa)<SUB>9-2x</SUB>Ce<SUB>x</SUB>Na<SUB>x</SUB>YAlSi<SUB>6</SUB>O<SUB>24</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

High quality colloidal GdVO₄:Yb,Er upconversion nanoparticles synthesized via a protected calcination process for versatile applications

Liang, Yanjie,Noh, Hyeon Mi,Xue, Junpeng,Choi, Haeyoung,Park, Sung Heum,Choi, Byung Chun,Kim, Jung Hwan,Jeong, Jung Hyun Elsevier 2017 Materials & Design Vol.130 No.-

<P><B>Abstract</B></P> <P>GdVO<SUB>4</SUB>:Yb,Er upconversion nanoparticles with high crystallinity and water dispersibility have been synthesized by a facile hydrothermal approach followed by a protected calcination treatment. The crude GdVO<SUB>4</SUB>:Yb,Er nanoparticles obtained by hydrothermal approach show cubic morphology with a diameter of about 45nm. A layer of SiO<SUB>2</SUB> was coated on the surface of nanoparticles to avoid particles growth and aggregation during thermal treatment. After the dissolution of SiO<SUB>2</SUB> layer by chemical etching in aqueous NaOH solution, the as-prepared highly crystalline GdVO<SUB>4</SUB>:Yb,Er nanoparticles not only maintain their nanostructure properties but show high chemical stability and good water dispersibility. Intense green upconversion luminescence is achieved under the 980nm laser diode excitation. The approach reported here can be “borrowed” to guide the synthesis of other oxide-based luminescent nanoparticles and will access their suitability for many technologically important applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High quality colloidal GdVO<SUB>4</SUB>:Yb,Er nanoparticles were synthesized by a protected calcination process. </LI> <LI> The obtained high crystallinity nanoparticles show excellent chemical stability, good water dispersibility and strong upconversion luminescence. </LI> <LI> The protected calcination approach can be extended to synthesize other luminescent oxide nanoparticles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Colloidal GdVO₄:Eu³⁺@SiO₂ nanocrystals for highly selective and sensitive detection of Cu²⁺ ions

Liang, Yanjie,Noh, Hyeon Mi,Park, Sung Heum,Choi, Byung Chun,Jeong, Jung Hyun Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.433 No.-

<P><B>Abstract</B></P> <P>Nowadays, in view of health and safety demands, the controlled design of selective and sensitive sensors for Cu<SUP>2+</SUP> detection is of considerable importance. Therefore, we construct herein core-shell colloidal GdVO<SUB>4</SUB>:Eu<SUP>3+</SUP>@SiO<SUB>2</SUB> nanocrystals (NCs) as optical sensor for the detection of Cu<SUP>2+</SUP>, which were synthesized by a facile hydrothermal reaction and encapsulated with a uniform layer of ultrathin silica through a sol-gel strategy. The NCs present strong red emission due to energy transfer from VO<SUB>4</SUB> <SUP>3−</SUP> groups to Eu<SUP>3+</SUP> when exciting with ultraviolet (UV) light. This intense red emission from Eu<SUP>3+</SUP> could be selectively quenched in the presence of Cu<SUP>2+</SUP> in comparison to other metal ions and the limit of detection is as low as 80nM in aqueous solution. It is revealed that the spectral overlap between the emission band of NCs and the absorption of Cu<SUP>2+</SUP> accounts for this intriguing luminescence behavior. The detection ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA) with the recovery of almost 100% of the original luminescence. The luminescence quenching and recovery processes can be performed repeatedly with good sensing ability. These remarkable performances allow the colloidal GdVO<SUB>4</SUB>:Eu<SUP>3+</SUP>@SiO<SUB>2</SUB> NCs a promising fluorescence chemosensor for detecting Cu<SUP>2+</SUP> ions in aqueous solution.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Core-shell colloidal GdVO<SUB>4</SUB>:Eu<SUP>3+</SUP>@SiO<SUB>2</SUB> nanocrystals were fabricated. </LI> <LI> Intense red emission from these nanocrystals could be selectively quenched by Cu<SUP>2+</SUP>. </LI> <LI> The limit of detection for Cu<SUP>2+</SUP> is as low as 80nM in aqueous solution. </LI> <LI> The detection ability is highly reversible by the addition of EDTA. </LI> <LI> The luminescence quenching and recovery processes can be repeated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Recent Progress in Luminescent Lanthanide Complexes for Advanced Photonics Applications

Kim, Hwan-Kyu,Oh, Jae-Buem,Baek, Nam-Seob,Roh, Soo-Gyun,Nah, Min-Kook,Kim, Yong-Hee Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.2

We have designed and developed novel luminescent lanthanide complexes for advanced photonics applications. Lanthanide(III) ions (Ln$^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins and naphthalenes. The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to Ln$^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of Ln$^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent Ln$^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent Ln$^{3+}$ complexes, yielding novel Ln(III)-cored dendrimer complex. The novel Ln(III)-cored dendrimer complex has much higher PL intensity than the corresponding simple complex, due to the efficient site-isolation effect. In this article, we will deal with recent progress in the synthesis and photophysical studies of inert and stable luminescent Ln$^{3+}$ complexes for advanced photonics applications. Also, our review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to Ln$^{3+}$ ions with Ln(III)-chelated prototype complexes.

Luminescent Lanthanide Complexes for Advanced Photonics Applications

Eom, Yu Kyung,Ryu, Jung Ho,Kim, Hwan Kyu Korean Society of Photoscience 2012 Rapid communication in photoscience Vol.1 No.1

Luminescent lanthanide complexes have been overviewed for advanced photonics applications. Lanthanide(III) ions ($Ln^{3+}$) were encapsulated by the luminescent ligands such as metalloporphyrins, naphthalenes, anthracene, push-pull diketone derivatives and boron dipyrromethene(bodipy). The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to $Ln^{3+}$ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of $Ln^{3+}$ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent $Ln^{3+}$ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent $Ln^{3+}$ complexes, yielding novel $Ln^{3+}$-cored dendrimer complex such as metalloporphyrins, naphthalenes, and anthracenes bearing the Fr$\acute{e}$chet aryl-ether dendrons, namely, ($Er^{3+}-[Gn-Pt-Por]_3$ (terpy), $Er^{3+}-[Gn-Naph]_3$(terpy) and $Er^{3+}-[Gn-An]_3$(terpy)). These complexs showed much stronger near-IR emission bands at 1530 nm, originated from the 4f-4f electronic transition of the first excited state ($^4I_{13/2}$) to the ground state ($^4I_{15/2}$) of the partially filled 4f shell. A significant decrease in the fluorescence of metalloporphyrins, naphthalenes and anthracene ligand were accompanied by a strong increase in the near IR emission of the $Ln^{3+}$ ions. The near IR emission intensities of $Ln^{3+}$ ions in the lanthanide(III)-encapsulated dendrimer complexes were dramatically enhanced with increasing the generation number (n) of dendrons, due to the site-isolation and the light-harvesting(LH) effects. Furthermore, it was first attempted to distinguish between the site-isolation and the light-harvesting effects in the present complexes. In this review, synthesis and photophysical studies of inert and stable luminescent $Ln^{3+}$ complexes will be dealt for the advanced photonics applications. Also, the review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to $Ln^{3+}$ ions with $Ln^{3+}$-chelated prototype complexes.

Recent Progress in Luminescent Lanthanide Complexes for Advanced Photonics Applications

Hwan Kyu Kim*,Jae Buem Oh,Nam Seob Baek,Soo-Gyun Roh,Min-Kook Nah,Yong Hee Kim 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.2

We have designed and developed novel luminescent lanthanide complexes for advanced photonics applications. Lanthanide(III) ions (Ln3+) were encapsulated by the luminescent ligands such as metalloporphyrins and naphthalenes. The energy levels of the luminescent ligands were tailored to maintain the effective energy transfer process from luminescent ligands to Ln3+ ions for getting a higher optical amplification gain. Also, key parameters for emission enhancement and efficient energy transfer pathways for the sensitization of Ln3+ ions by luminescent ligands were investigated. Furthermore, to enhance the optophysical properties of novel luminescent Ln3+ complexes, aryl ether-functionalized dendrons as photon antennas have been incorporated into luminescent Ln3+ complexes, yielding novel Ln(III)-cored dendrimer complex. The novel Ln(III)-cored dendrimer complex has much higher PL intensity than the corresponding simple complex, due to the efficient site-isolation effect. In this article, we will deal with recent progress in the synthesis and photophysical studies of inert and stable luminescent Ln3+ complexes for advanced photonics applications. Also, our review will include the exploratory investigation of the key parameters for emission enhancement and the effective energy transfer pathways from luminescent ligands to Ln3+ ions with Ln(III)-chelated prototype complexes.

발광해파리의 조형성을 응용한 의상디자인 연구 - 축광소재를 중심으로 -

박나영,박선희 한국니트디자인학회 2010 패션과 니트 Vol.8 No.1

In modern society, people take interests more and more in new materials stronger than the existing fibers and having new functions. In this study, the author recognized the importance of these new materials to graft luminescent material, a new material having luminescent factor, on luminescent jellyfish having newly and independent modeling among the animals having luminescent factor. The purpose of this study is to suggest the convergence of inspiration for the aesthetical value through developing more integrated and independent works, grafting luminescent material on luminescent jellyfish. Together with this, the author tried to prove its scientific factors and improve the access as artistic aspect. Also, the author found aesthetic factors from scientific new material to enhance its value of design and to prove that extend its possibility to broader, art and science are not different concept each other and covering each other's area.

주행 시뮬레이션을 이용한 자체 발광형 노면표시 효과평가

김지원,오흥운 한국도로학회 2023 한국도로학회논문집 Vol.25 No.1

PURPOSES : The purpose of this study is to evaluate the effectiveness of self-luminescent road markings using driving simulation. METHODS : In this study, a driving simulation was conducted to evaluate the effectiveness of self-luminescent road markings. The details of this study are as follows. Highway sections were categorized as tunnels, tunnel approaches, bridges, merging areas, mainlines, and curbs. The luminance of the existing road markings was collected through field measurements. The luminance of the self-luminescent road markings was collected through experimental measurements. The luminance of the road markings is converted into a brightness ratio to be applied to the driving simulation. Road facilities at night were visualized during the driving simulation. Driving simulation was tested by 30 participants. Each participant rated the visibility perception of both the road markings ahead of 90 m with a 5-point scale. The log data generated from the driving simulation tests were analyzed. RESULTS : The luminance of the existing road markings and self-luminescent road markings was measured. The luminance of the existing and lab-based road markings was converted into a brightness ratio. The road facilities of highway sections were investigated for driving simulations. The driving simulation was tested by 30 participants. Visibility perception ratings and log data from the driving simulation were analyzed. The average of visibility point increased from 1.01 to 4.63 when self-luminescent road markings were added to the existing road markings. The average speed also increased when self-luminescent road markings were added to existing road markings. CONCLUSIONS : In conclusion, self-luminescent road markings can improve the visibility of road markings and driving speed, particularly in highway sections where driving speed decreases owing to low visibility.

Measurement of Human Cytochrome P450 Enzyme Induction Based on Mesalazine and Mosapride Citrate Treatments Using a Luminescent Assay

( Young-hoon Kim ),( Young-ji Bae ),( Hyung Soo Kim ),( Hey-jin Cha ),( Jae-suk Yun ),( Ji-soon Shin ),( Won-keun Seong ),( Yong-moon Lee ),( Kyoung-moon Han ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.5

Drug metabolism mostly occurs in the liver. Cytochrome P450 (CYP) is a drug-metabolizing enzyme that is responsible for many important drug metabolism reactions. Recently, the US FDA and EU EMA have suggested that CYP enzyme induction can be measured by both enzymatic activity and mRNA expression. However, these experiments are time-consuming and their interassay variability can lead to misinterpretations of the results. To resolve these problems and establish a more powerful method to measure CYP induction, we determined CYP induction by using luminescent assay. Luminescent CYP assays link CYP enzyme activity to firefly luciferase luminescence technology. In this study, we measured the induction of CYP isozymes (1A2, 2B6, 2C9, and 3A4) in cryopreserved human hepatocytes (HMC424, 478, and 493) using a luminometer. We then examined the potential induction abilities (unknown so far) of mesalazine, a drug for colitis, and mosapride citrate, which is used as an antispasmodic drug. The results showed that mesalazine promotes CYP2B6 and 3A4 activities, while mosapride citrate promotes CYP1A2, 2B6, and 3A4 activities. Luminescent CYP assays offer rapid and safe advantages over LC-MS/MS and qRT-PCR methods. Furthermore, luminescent CYP assays decrease the interference between the optical properties of the test compound and the CYP substrates. Therefore, luminescent CYP assays are less labor intensive, rapid, and can be used as robust tools for high-throughput CYP screening during early drug discovery.