일반 가열 아스팔트 혼합물 생산 시 높은 온도로 이산화탄소 및 대기오염물질이 발생함으로써, 유럽 및 선진국들은 탄소배출 저감 이 가능한 중온 아스팔트(warm mix asphalt, WMA)를 사용하는 추세이다. 아스팔트 콘크리트의 생산온도를 낮출수록 이산화탄소 발생 량과 연료 소비량을 저감시킬 수 있어 중온 아스팔트 콘크리트에 대한 수요성은 증가하고 있으나 국내외로 중온 아스팔트 콘크리트의 생산온도는 120℃의 한계성을 극복하지 못하고 있는 실정으로 120℃ 이하의 생산기술을 확보하기 위해서는 기능성 개질재 제조기술 개발이 필요하다. 본 연구에서는 110±10℃의 생산온도에서 저온화 고분자형 개질재를 첨가하여 폴리머 개질 저온 아스팔트(Polymer Cool Mix Asphalt, PCMA)를 생산하였으며, PCMA 혼합물의 마샬안정도, 공극률, 동적안정도 및 인장강도비 등을 시험 평가하여 10년 이상의 공용 내구연한 확보를 확인하였다. 또한, 일반 가열 아스팔트 혼합물, 타사 중온화 첨가제를 적용한 아스팔트 혼합물 및 PCMA 혼합물의 비교평가를 실시하였으며 PCMA 혼합물의 피로균열지수(Cracking Tolerance Index) 및 노화계수(Aging Coefficient)가 비교적 매우 우수한 것으로 나타났다. 2024년 8월, 베트남 바리어붕따우성에서 PCMA 혼합물 생산 및 시공을 실시한 결과, 목표 생산온도인 110±10℃의 조건을 확보하였으며, 현장 포설시에도 특이사항 없이 시공이 완료되었다.

In this paper, the adsorption removal characteristic for 10 species of perfluoroalkyl and polyfluoroalkyl substances (PFAS) was investigated using GAC and modified GAC (GAC-Cu). After modification with Cu(II), the amount of copper was to 1.93 and 4.73 mg/g for GAC and GAC-Cu, respectively. The total amount of 10 species of PFAS per specific area was obtained to 0.548 and 0.612 ng/m2 for GAC and GAC-Cu, respectively. A series of batch test confirmed lower efficiency was observed with a smaller number of carbon chain length and the removal efficiency of PFCA (perfluoroalkyl carboxylic acids) was lower than that of PFSA (perfluoroalkyl sulfonic acids) with the same carbon chain length. Regarding the pH effect, the adsorption capacity was decreased with increase of pH due to the increase of electrostatic repulsion. According to pseudo first and second order (PFO and PSO) kinetic models, while the values of equilibrium uptake and time did not show significant difference, a difference in uptake was observed between 24-48h. Furthermore, based on correlation analysis, Log Kow and uptake have a high correlation with molecular weight (M.W.) and initial concentration, respectively. These results show that long-chain PFAS have higher removal efficiency due to their increased hydrophobicity.

Flexible electrodes, particularly paper electrodes modified with polypyrrole, have shown promise in energy-related applications. We have earlier demonstrated the usage of paper electrodes modified with polypyrrole as a flexible and suitable photoanode for photoelectrochemical water splitting (PEC). Further, modification of this electrode system with an appropriate tandem absorber system for solar fuel production is interesting in developing efficient photoanodes. In this study, we study the PEC performance of flexible polypyrrole-based paper photoanodes (PPy-PAs) by decorating them with rGO@Cu2Zn- SnS4 chalcopyrites (rGO@CZTS/PPy-PAs). The lower bandgap (~ 1.5 eV) of the rGO@CZTS/PPy-PAs system allows for efficient visible light absorption, substantially improving PEC water-splitting reactions. The rGO@CZTS/PPy-PAs exhibited an enhanced current density of ~ 13.2 mA/cm2 at 1.23 V vs RHE, ABPE of ~ 1.5%, and a hydrogen evolution rate of 177 μmoles/min/cm2. Overall, rGO@CZTS/PPy-PAs showed 2.1-fold, 1.1-fold, and 1.4-fold enhancement in photocurrent activity over PPy-PAs, CZTS/PPy-PAs, and rGO/PPy-PAs, respectively. The usability of rGO@CZTS/PPy-PAs is established in the form of stable photocurrent for more than 200 min. These findings open new possibilities for developing modified PPy PAs as flexible PEs for efficient solar-driven PEC devices and give directions on improving flexible PEs for flexible and efficient solar-driven PEC systems.

Graphene-based materials modified with transition metals, and their potential utilization as hydrogen storage devices, are extensively studied in the last decades. Despite this widespread interest, a comprehensive understanding of the intricate interplay between graphene-based transition metal systems and H2 molecules remains incomplete. Beyond fundamental H2 adsorption, the activation of H2 molecule, crucial for catalytic reactions and hydrogenation processes, may occur on the transition metal center. In this study, binding modes of H2 molecules on the circumcoronene (CC) decorated with Cr or Fe atoms are investigated using the DFT methods. Side-on (η2-dihydrogen bond), end-on and dissociation modes of H2 binding are explored for high (HS) and low (LS) spin states. Spin state energetics, reaction energies, QTAIM and DOS analysis are considered. Our findings revealed that CC decorated with Cr (CC-Cr) emerges as a promising material for H2 storage, with the capacity to store up to three H2 molecules on a single Cr atom. End-on interaction in HS is preferred for the first two H2 molecules bound to CC-Cr, while the side-on LS is favored for three H2 molecules. In contrast, CC decorated with Fe (CC-Fe) demonstrates the capability to activate H2 through H–H bond cleavage, a process unaffected by the presence of other H2 molecules in the vicinity of the Fe atom, exclusively favoring the HS state. In summary, our study sheds light on the intriguing binding and activation properties of H2 molecules on graphene-based transition metal systems, offering valuable insights into their potential applications in hydrogen storage and catalysis.

Industrial activities that utilize nuclear technology can cause radioactive contamination in the ecosystems. In particular, cesium (Cs) has problems, such as neurological diseases, when it is exposed and accumulated in the bodies of animals, plants, and humans for a long time. Therefore, the development of simple and economical adsorbents for Cs removal is required. In this study, the surface of petroleum residue pitch was modified using NaClO and it was used to remove Cs from an aqueous solution. Batch experiments and characterization of the modified adsorbent were performed to determine the adsorption mechanism between the adsorbent and Cs. From these results, chemical and monolayer adsorption were found to occur at the carboxyl groups on the adsorbent surface, along with a cation exchange reaction occurred due to the sodium ions on the surface. Through this modification process, the total acidity, including phenolic, lactonic and carboxylic functional groups, was improved to 1.563 mmol/g and the maximum adsorption capacity of Cs for the modified adsorbent was 65.8 mg/g.

In this study, the aromatic carbon content of epoxy resin (EP) increased via carbon tar pitch (CTP) modification, and the CTP occurred self-polymerization reaction. The carboxyl and hydroxyl groups of CTP and the hydroxyl and carboxyl groups of EP occurred chemical cross-linking reaction. CTP and graphitization treatment promoted EP CF carbon crystal growth. The graphitization degree of pure EP CF and 40 wt% CTP modified EP CF are 8.42% and 44.21%, respectively. With the increase CTP content, the cell size, ligament junction and density of graphitization modified EP CF gradually increased, while the number of pores and cells gradually decreased. The cell size, ligament junction size and density of 40 wt% CTP modified graphitization EP CF increased to 1200 μm, 280 μm and 0.5033 g/cm3, respectively. EP CF exhibits entangling carbon ribbon and isotropic amorphous carbon. The 40 wt% CTP modified EP CF is composed of evenly distributed amorphous resin carbon and graphite domain CTP carbon. The graphitization modified EP CF improved electrical conductivity, and the electrical conductivity of 40 wt% CTP modified EP CF is 126.6 S/m. The compressive strength can be decided by EP carbon strength and its char yield, and graphitization 40 wt% CTP modified EP CF reached 4.9 MPa. This study provides some basis for preparation and application of CTP modified EP CF.

Graphene-modified melamine sponges (RGO-MSs) were prepared, as adsorbents with photothermal conversion ability, utilizing solar energy to achieve heavy oil temperature rise, viscosity reduction, and efficient adsorption recovery of highly viscous oil. The RGO-MSs were prepared through a simple impregnation method. The photothermal performance and heavy oil adsorption performances of RGO-MSs with different densities and thicknesses were observed. It was found that as the density increases, the thermal conductivity of RGO-MS increases too, leading to the increase of the average oil absorption rate. The reduction of thickness is beneficial to improving of the adsorption rate. The prepared RGO-MS with a density of 21.5 mg/cm−3 and a height of 1 cm (RGO-MS-3-1) shows excellent mechanical properties and fatigue resistance. Cyclic adsorption–desorption of RGO-MS-3-1 was achieved through extrusion/ ethanol washing. After 10 cycles of reuse through extrusion, the adsorption capacity decreased from 52.90 to 50.02 g g− 1, with a loss of 5.4%. The material was then washed with petroleum ether and ethanol in turn. Its adsorption capacity can restored to 98.8% of the initial value, showing a promising application prospect on heavy oil leakage treatment. The easily prepared RGO-MS exhibits excellent light absorption and photothermal oil adsorption properties, providing a good solution for the problem of heavy oil leakage at sea.

Bortezomib (BTZ) and dasatinib (DA) are two substantial anti-cancer agents with side effects on the human body. In this research, we fabricated a novel electrochemical sensor modified by CuFe2O4/ SmVO4 nanocomposite and 1-ethyl-3-methylimidazolium chloride (1E3MC) as an ionic liquid (IL) ( CuFe2O4/SmVO4/IL/CPE) for coinciding investigation of BTZ and DA for the first time. The CuFe2O4/ SmVO4 synthesized were determined and certified through field-emission scanning electron microscopy (FE-SEM), energy diffraction X-ray (EDX), and X-ray diffraction (XRD). The capability of the sensor was investigated by different electrochemical techniques such as cyclic voltammetry (CV), chronoamperometry (CHA), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The attained data showed that the oxidation signal of bortezomib and dasatinib promoted as an innovative electrochemical sensor. After optimization of the conditions using this sensor at pH 7.0, the oxidation signal of bortezomib and dasatinib showed to be linear with drug concentrations in the range of 0.09–90 μM and 100–500 μM with a detection limit of 5.4 nM and 7.0 μM, respectively, using differential pulse voltammetry method. The values of D and electro-transfer coefficient (α) achieved 2.5 × 10− 5 cm2 s− 1 and 0.99, respectively. The proposed electrochemical sensor exhibited acceptable selectivity and sensitivity for simultaneous detection of bortezomib and dasatinib in pharmaceutical and biological samples.

Regulatory Guide (RG) 1.60 presents the response spectra for the seismic design, especially for the safe shutdown earthquake (SSE), of nuclear power plants. This guide is applicable to a two-step process involving the issuance of construction permits and operating licenses (10 CFR Part 50) as well as the issuance of combined construction and operating licenses (COLs), early site permits (ESPs), and standard plant design certifications (10 CFR Part 52) [1]. New reactor designs, however, require modified design response spectra (MDRS) by broadening the high-frequency range from design response spectra (DRS) in RG 1.60. In order to generate artificial time histories to meet the acceptable criteria described in NUREG-0800 [2], it9s necessary to develop the power spectral density of the MDRS. In this paper, we generate the artificial earthquake time histories of the MDRS for further research.

Sulforaphane is a naturally occurring active substance found in vegetables that is known for its potential in preventing and treating cancer. This compound has demonstrated promising effects in inhibiting the growth of various types of cancer, including esophageal, lung, colon, breast, and liver cancer. However, its instability towards pH and heat limits its application in the medical and food industries. To address this challenge, novel drug delivery systems have been developed to improve the stability and efficacy of sulforaphane, making it a more suitable candidate for clinical use in cancer research. In this study, nanocomposite materials were prepared using multi-walled carbon nanotubes (MWCNTs) and chitosan (CS) as base materials, with polydopamine (PDA) acting as a bridge material. The synthesized composite materials were used as drug carriers for the release of sulforaphane. The results of the study showed that the drug loading increased with an increase in the concentration of sulforaphane, indicating that the nanocomposite materials were effective in delivering and releasing the drug. Moreover, a positive correlation was observed between the drug loading and the thickness of the PDA layer. These findings suggest that the use of MWCNTs, CS, and PDA in the development of drug delivery systems can enhance the stability and efficacy of sulforaphane, potentially leading to improved cancer treatment outcomes.

교통량이 증가하고 교량과 같은 특수구조물에 아스팔트 포장이 시공되는 사례가 증가함에 따라 일반적으로 사용되는 아스팔트보다 높은 성능을 가진 아스팔트에 대한 수요가 증가하고 있다. 일반 아스팔트 혼합물은 내구연한이 지나면 재생첨가제 등을 사용하여 다 시 도로포장재료로서 재활용할 수 있는 방안이 마련되어 있으나, 개질 아스팔트가 사용된 폐아스팔트 혼합물은 매립재로 사용하는 것 이외에는 별다른 대안이 없는 실정이다. 이에 본 연구에서는 국토부 지침에 규정된 재활용 아스팔트 혼합물 배합설계법을 적용하여 개질 폐아스팔트 혼합물을 재활용할 수 있는지를 검토해보고자 하였다. 이를 위해 개질 아스팔트를 활용하여 혼합물을 제작하였으며, 현장에서 수거되는 폐아스팔트 혼합물의 노화상태를 모사하기 위해 AASHTO R 30을 참고하여 강제 노화를 실시하였다. 노화 및 추출 과정에서 아스팔트의 물성 변화를 확인하기 위해 절대점도, DSR, MSCR 시험을 실시하였다. 시험결과, 추출 후 바인더의 절대점도는 감소하였으나 G*(복합전단계수)와 δ(위상각)은 증가하는 경향을 보였다. 소성변형 저항성을 확인하기 위해 MSCR(다중 응력 크리프 및 회복) 시험을 실시한 결과,  이 2배 가까이 증가하여 소성변형 저항성이 감소한 것을 확인할 수 있었다. 이러한 결과는 추출시 사용 되는 용매가 개질첨가제를 추출하지 못하여 기인한 결과로 판단된다. 따라서 개질 폐아스팔트 혼합물을 재활용하기 위해서는 기존과 는 다른 별도의 배합설계법이 개발되어야 할 것으로 판단되었다.

In order to prevent early distress in asphalt pavement and save on subsequent operational and maintenance costs, modifying asphalt is an effective approach. Styrene–butadiene–styrene (SBS) block copolymers, due to their excellent physicochemical properties, have become a mature and widely used asphalt modifier. Carbon nanotubes (CNTs) possess advantages such as a large specific surface area and high modulus, which, when incorporated into asphalt, can enhance its deformation resistance. To analyze the effect of incorporating CNTs on SBS-modified asphalt (SBS-A), this study analyzed the influence of different CNT concentrations on the high and low-temperature performance and aging properties of SBS-A through penetration, softening point, ductility, dynamic shear rheometry, and short-term aging tests. The optimal CNT concentration was determined to be 1.0%. Furthermore, the changes in the modified asphalt during the aging process were analyzed using infrared spectroscopy.

Background: Effective trunk stabilization has been a cornerstone in physiotherapy, particularly for individuals with lower back issues. While bridging exercises were traditionally employed for this purpose, there has been a growing interest in their modified versions to optimize therapeutic benefits. Objectives: To investigated the differential effects of traditional and modified bridging exercises, particularly when varying leg support and integrating abduction maneuvers during sling-assisted exercises, on trunk muscle responsiveness. Design: Cross-Sectional study. Methods: A group of twenty participants was subjected to three exercise protocols: Bilateral Limb Bridging (BLB), Single Limb Bridging (SLB), and Single Limb Bridging combined with Hip Abduction (SLBHA). Using Surface Electromyography (EMG), the study captured the activation patterns of the Internal Oblique (IO), Erector Spinae (ES), and Multifidus (MF) muscles. Statistical analysis was conducted using the Kruskal-Wallis test, with post-hoc examination for detailed insights. For data consistency, normalization was executed based on Maximum Voluntary Isometric Contractions, and EMG data interpretation was conducted using the RMS technique. Results: The most prominent variations in muscle activation were identified in the IO muscles on both sides. The left IO displayed marked activation disparities between BLB vs. SLB and SLB vs. SLBHA. Analogous observations were made for the right IO when comparing BLB to SLBHA and BLB to SLB. Conversely, ES and MF muscle activations remained consistent across the different exercises. Conclusion: Modified bridge exercises with sling-assisted leg supports with abduction can selectively activate IO muscles, with a noticeable asymmetrical effect favoring the left side.

In this study, we investigate the impact of Isophorone diisocyanate functionalized graphene oxide (IPDI-GO) on the flame retardancy of rigid polyurethane foam (RPUF). IPDI-GO was synthesized and introduced into the RPUF matrix. The flame retardancy of RPUF was significantly enhanced by the incorporation of IPDI-GO, as evidenced by a reduction in peak heat release rate (PHRR) by 25% and total smoke production (TSP) by 15% in comparison to pure RPUF when IPDI-GO was incorporated at 3 wt%. Scanning electron microscopy (SEM) revealed that IPDI-GO contributed to the formation of a compact, continuous char layer on the RPUF surface. This study underscores the potential of IPDI-GO as a promising flame retardant additive for RPUF.

Dimethyl silicone oil is widely used due to its excellent thermal stability and good wetting properties. In this study, a series of thermal conductive materials was prepared by physically blending and chemically loading graphene as a thermal conductive filler into dimethyl silicone oil, and their thermal conductivity and tribological properties were investigated. The thermal conductivity of the composites was tested by a thermal conductivity meter and a thermal imaging camera, while the tribological properties of the composites were evaluated using a CSM friction and wear tester. The results showed that both thermal conductivity and tribological properties were improved to a certain extent. The particle size and amount of graphene had a significant influence on the thermal conductivity. For graphene with a single particle size, the thermal conductivity increased with increasing graphene content. The friction coefficient under dry friction conditions was significantly reduced by adding graphene to the silicone oil, as revealed by the friction and wear test.

A glassy carbon electrode modified with a composite consisting of electrodeposited chitosan and carboxylated multi-walled carbon nanotubes (e-CS/MWCNTs/GCE) was used as a working electrode for simultaneous determination of dopamine (DA), serotonin (5-HT) and melatonin (MT), which were related to circadian rhythms. The electrochemical characterizations of the working electrode were carried out via electrochemical impedance spectroscopy and chronocoulometry. It was found that electrochemical modification method, that was cyclic voltammetry, may can cause continuous CS polymerization on MWCNTs surface to form a dense membrane with more active sites on the electrode, and the electrochemically active surface area of e-CS/MWCNTs/GCE obtained was about 7 times that of GCE. The electrochemical behaviour of DA, 5-HT and MT on working electrode were carried out via differential pulse voltammetry and cyclic voltammetry. The results showed that e-CS/MWCNTs/GCE solved the problem that the bare electrode could not detect three substances simultaneously, and can catalyze oxidation potential difference as low as 0.17 V of two substances reaction at the same time, indicating very good electrocatalytic activity. By optimizing the detection conditions, the sensor showed a good linear response to DA, 5-HT and MT in the range of 20-1000 μmol/L, 9-1000 μmol/L and 20-1000 μmol/L, and the detection limits were 12 μmol/L, 10 μmol/L and 22 μmol/L (S/N = 3), respectively. In addition, the proposed sensor was successfully applied to the simultaneous detection of DA, 5-HT and MT in human saliva samples.

In the present study, an innovative electrochemical sensing platform was established for sensitive detection of NO2 —. This sensor was developed using CoFe alloy encapsulated in nitrogen-doped carbon nanocubes (named as CoFe@NC-NCS), synthesized through the calcination of polydopamine-coated CoFe Prussian-blue analogues (CoFe-PBA@PDA). The morphological and electrochemical characterization reveals that the CoFe@NC-NCS possesses high electrocatalytic activity for electrochemical quantitation of NO2 —, ascribed to the huge surface area and plentiful active positions, benefiting from the porous, hollow, and core–shell structure of CoFe@NC-NCS. Under the optimal conditions, CoFe@NC-NCS/GCE possessed remarkable sensing performance for NO2 — with wide liner ranges and a detection limit of 0.015 μM. NO2 — recovery experiments in real samples exhibited recoveries in the range of 98.8–103.5%. Hence, the CoFe@NC-NCS shows great promise for the construction of electrochemical sensor with more potential application.

PURPOSES : This study was conducted to evaluate the physical properties of the RAP 50 asphalt mixture containing polymer modified rejuvenator and warm-mix additive to improve the recycling rate of RAP and reduce CO2 emission. METHODS : Mix design of Polymer Modified Warm-mix Asphalt Mixture(RAP 50), and Hot Mix Asphalt Mixture(RAP 30) were produced and the properties of asphalt mixture such as Marshall Stability, ITS, Deformation Strength, TSR, and Dynamic Stability were compared between the two asphalt mixtures. RESULTS : The RAP 50 asphalt mixture showed superior or similar performances compared to the RAP 30 asphalt mixture in all the tests conducted. The results of the Marshall stability and dynamic stability in particular were 13,045N and 3,826 pass/mm, which were 11.37% and 76.7% greater than the RAP 30 asphalt mixture, which indicated that high plastic deformation resistance may be expected. CONCLUSIONS : The results obtained from laboratory tests on the two types of mixtures indicated that the use of polymer modified rejuvenator and warm-mix additive not only allows to increase the proportion of RAP but also improves its properties under lower temperature condition than RAP 30 asphalt mixture. Additionally, it was confirmed that plastic deformation resistance was high and moisture resistance and crack resistance were improved for a RAP 50 asphalt mixture.

This study established optimal cookie conditions by varying the amount of modified starch treated with octenyl succinic anhydride (OSA). It also investigated the quality and digestion characteristics of the cookies produced. The moisture content increased as the amount of OSA-modified starch added to the cookies increased. As for cookie color brightness, the redness and yellowness decreased as the OSA-modified starch content increased. The spread factor and hardness of the cookies showed the most similar results for control and OSA: 20%. As the amount of OSA-modified starch added to cookies increased, RS tended to increase. It was found that OSA-modified starch cannot easily replace wheat flour completely and that the optimal amount of OSA-modified starch added to cookies is 20%. OSA-modified starch can be used not only as a cookie but also as a low-calorie food ingredient.