One-step hydrothermal reduction method was used to prepare three-dimensional carbon fiber brush-based graphene–platinum (CFB/Pt–G) composites to improve the electrocatalytic oxygen reduction activity of cathode materials for seawater oxygen-dissolved battery. Characterization results show that the reduced graphene oxide of as-prepared graphene–platinum composite displays the few-layer folded structure. In addition, Pt nanoparticles with the polycrystalline structure dispplay a preferential growth along the crystal plane of (111) and are mainly distributed around the defect cavities of folded graphene. Electrochemical results show that the diffusion-limited current density of CFB/Pt–G composite tested with 1600 rpm/min in 3.5% NaCl solution reaches 5 mA/cm2, while that of CFB/G is only 2.64 mA/cm2. Battery discharge results show that the maximum volume power density of CFB/Pt–G–Mg battery with a stable open voltage of 1.73 V is 81 times as much as the commercial seawater battery SWB1200.

The development of graphene and graphene-like materials has been a breakthrough in the field of nanotechnology for its exceptional properties. It exhibits extraordinary properties owing to its unique, regular arrangement of carbon atoms in it. However, graphene is usually modified for specific applications, by introducing disorder in the system. Since disorders are ubiquitous during the synthesis of graphene and graphene-like materials, it is best to exploit the defects for tuning its exceptional properties for suitable device applications. Like in any material, the disorder can drastically affect the properties, and hence they are deliberately incorporated into the material. In this review, we discuss topics related to the creation and configuration of disorders in graphene such as corrugations, topological defects, vacancies, adatoms and sp3- defects. The effects of these disorders on the electrical, thermal, chemical and mechanical properties of graphene are analysed subsequently. Finally, we review earlier works on the modulation of structural defects in graphene for specific applications.

As a new nanostructure, a graphene is a compound of carbon atoms with a two-dimensional structure that has attracted the attention of many nanoscale researchers due to its novel physical and chemical properties. The presence of all graphene atoms in the surface and its unique electrical properties, as well as the ability to functionalize and combine with another nanomaterial, has introduced graphene as a new and suitable candidate material for gas sensing. Over the years, many researchers have turned their attention to carbon nanomaterial. The unique optical, mechanical, and electronic properties of these nanostructures have led them to use these nanomaterials to develop tiny devices, such as low-consumption sensors. Carbon nanomaterial poses a threat to another nanomaterial in terms of their use in gas sensors. This review article discusses the use of carbon nanoparticles and graphene in gas sensors, examines the nodes in the commercialization pathway of these compounds, and presents the latest achievements. Finally, the perspectives of the challenges and opportunities in the field of sensors based on carbon nanomaterial and graphene are examined.

Effect of sulfation processes on the physicochemical properties of ZrO2 and TiO2 nanoparticles were thoroughly investigated. SO4/ZrO2 and SO4/TiO2 catalysts were synthesized to identify the acidity character of each. The wet impregnation method of ZrO2 and TiO2 nanoparticles was employed using H2SO4 with various concentrations of 0.5, 0.75, and 1 M, followed by calcination at 400, 500, and 600 °C to obtain optimum conditions of the catalyst synthesis process. The highest total acidity was found when using 1 M SO4/ZrO2-500 and 1 M SO4/TiO2-500 catalysts, with total acidity values of 2.642 and 6.920 mmol/ g, respectively. Sulfation increases titania particles via agglomeration. In contrast, sulfation did not practically change the size of zirconia particles. The sulfation process causes color of both catalyst particles to brighten due to the presence of sulfate. There was a decrease in surface area and pore volume of catalysts after sulfation; the materials’ mesoporous structural properties were confirmed. The 1 M SO4/ZrO2 and 1 M SO4/TiO2 catalysts calcined at 500 °C are the best candidate heterogeneous acid catalysts synthesized in thus work.

Porous basalt aggregate is commonly used in roadbed engineering, but its application in concrete has rarely been studied. This paper studies the application of porous basalt in concrete. Porous basalt aggregate is assessed for its effects on mechanical strength and durability of prepared C50 concrete; because it has a hole structure, porous basalt aggregate is known for its porosity, and porous basalt aggregates can be made full of water through changing the content of saturated basalt; after full-water condition is achieved in porous basalt aggregate mixture of C50 concrete, we discuss its mechanical properties and durability. The effects of C50 concrete prepared with basalt aggregate on the compressive strength, water absorption, and electric flux of concrete specimens of different ages were studied through experiments, and the effects of different replacement rates of saturated porous basalt aggregate on the properties of concrete were also studied. The results show that porous basalt aggregate can be prepared as C50 concrete. For early saturated porous basalt aggregate concrete, its compressive strength decreases with the increase of the replacement rate of saturated aggregate; this occurs up to concrete curing at 28 d, when the replacement rate of saturated basalt aggregate is greater than or equal to 40 %. The compressive strength of concrete increases with the increase of the replacement rate of saturated aggregate. The 28 d electric flux decreases with the increase of the replacement rate of saturated aggregate, indicating that saturated porous basalt aggregate can improve the chloride ion permeability resistance of concrete in later stages.

To investigate the domestic seed production potential of Italian ryegrass, it was sown in autumn in the southern region and harvested in the spring of the following year to investigate the productivity and quality of seeds and straw. Italian ryegrass (Lolium multiflorum Lam.) ‘GreenCall’ variety was sown in Jinju, Gyeongnam in the fall of 2020 with three seeding rates (20, 30 and 40 kg/ha). The experiment was arranged consisted of a randomized block design with three replications. The ryegrass was sown on October 17, 2020, and the harvest was on May 31, about 60 days from the heading stage. The heading stage of Italian ryegrass was April 28, and there was no difference among treatments. Plant height was significantly shorter in the 40 kg/ha seeding treatment group, and there was no significant difference in the remaining treatments. The resistance of lodging, disease, and cold did not show significant differences among treatments. Spike length and number of seeds per spike were highest at 20 kg/ha seeding amount, and there was no difference in the remaining treatments. The seed yield was the highest at 1,956 kg/ha in the 20 kg/ha seeding rate, and there was no difference in the 30 and 40 kg/ha seeding rates. The dry matter content of seeds and straws was 45.60 and 41.83% on average, and there was no significant difference among treatments. The amount of remaining straw after seed harvesting was found to be 7,689 kg/ha on average on a dry basis, and it was high in the 40 kg/ha sowing area, but there was no significant difference among treatments. According to the above results, it was found that it is most advantageous to sow at 20 kg/ha when producing Italian ryegrass seeds through autumn sowing in the southern region.

목적 : 중국의 옵토메트리(optomerty) 관련 제도를 조사하고 분석하였으며, 중국 안경사 제도의 새로운 변화 와 발전을 고찰하고자 하였다. 방법 : 중국의 옵토메트리(optometry) 관련 정보를 중국학술정보원(China National Knowledge Infrastructure, 中國知网), 중국안광협회(China Optometric and Optical Association, COOA), 바이두(Baidu), 중국인민공 화국교육부(Ministry of Education of the People's Republic of China) 및 학술연구정보서비스(RISS)를 통해 검색하고 수집하였다. 결과 : 중국의 옵토메트리스트(optometrist)는 안경 험광원(5등급) 및 정배공(4등급)으로 구분되며, 등급별로 업무 범위와 시험제도가 나뉜 것으로 나타났다. 시험내용은 국가인력자원보장부가 규정한 안경 험광원 및 정배공 시험제도를 따르고 있다. 안경 험광원 및 정배공 직업 자격의 규정이 시대적인 변화에 따라 ‘자격평가용’에서 ‘기능 등급인정용’으로 바뀌었으며, 핵심적 변화로 주최기관 또한 정부에서 관련 업계 내의 권위와 공신력을 갖추고 사 회적 인지도가 비교적 높은 민간기관으로 바뀐 것으로 나타났다. 결론 : 중국의 옵토메트리(optometry) 제도는 주최가 정부에서 민간기관으로 변화되었으며, 직종에 따라 업무, 등급 및 시험방법을 명확하게 구분하고 있다. 하지만 통일된 국가시험이 없고, 표준화 과정을 거치지 않아 평가에 일관성이 부족하다. 향후 중국 안경 시장의 큰 수요를 충족시키고 전문성을 강화하기 위해서 현행 제도를 엄격하 게 관리할 필요가 있다고 판단된다.

최근 살진균제는 세계 식량 안보에 없어서는 안될 필수 요소이며, 그 사용량은 증가하고 있다. 살진균제는 직접적 또는 간접적으로 곤충에 영 향을 미쳐 유전자 및 분자 수준의 변화를 일으킨다. 곤충은 다양한 해독 매커니즘을 통해 살진균제를 포함한 농약으로부터 유발되는 활성산소 (ROS) 독성을 제거한다. 본 연구는 살진균제 캡탄의 비치명적 투여량(0.2, 2, and 20 μg/μL)을 주입 후 갈색거저리의 유충에서 해독효소의 mRNA 발현량을 분석했다. 갈색거저리의 전사체 분석을 통해 해독 매커니즘 관련 유전자인 퍼옥시다제(POX), 카탈라제(CAT), 슈퍼옥사이드 디스뮤타제(SOD) 및 글루타티온-S-트랜스퍼라제(GST)를 발굴하였다. 처리 24시간 후 TmPOX5 mRNA가 유의하게 증가한 것으로 나타났다. 처리 3 시간 후 TmSOD4의 mRNA가 유사하게 증가하였다. 또한 2 μg/μL 처리 24시간 후 TmCAT2의 mRNA 가 유의하게 증가하였다. 캡탄 노출 후 TmGST1 및 TmGST3의 mRNA 발현량도 증가하였다. 결론적으로, TmPOX5 및 TmSOD4 유전자는 갈색거저리에서 캡탄 노출에 대한 바이오마커 또는 생체이물 센서로 작용할 수 있음을 시사한다.

진드기는 박테리아, 바이러스, 원생동물 및 균류를 포함한 다양한 병원체를 전달할 수 있는 감염병매개체이다. 진드기는 불리한 환경조건에 서도 생존할 수 있는 능력이 있으며, 흡혈이 필수적인 절지동물의 진화적 산물로써 비흡혈 기간이 장기간 지속되는 경우에도 생존이 가능하다. 특 히, 높은 온도와 낮은 습도 환경에서도 견딜 수 있는 수분 조절 메커니즘과 내열성의 생리적 특징은 진드기가 전 세계적으로 분포하도록 한 중요한 요인이다. 진드기의 침샘, 말피기관, 후장 그리고 뇌를 포함하는 여러 기관이 관여하는 물과 이온의 획득 및 배출은 복합적인 메커니즘에 의해 조절 된다. 진드기가 수분을 확보하는 주요 경로는 흡혈과정 또는 공기 중 수증기를 직접 포집하는 방식이며, 이와 더불어 진드기가 자연조건에서 맺힌 물방울을 직접 마시며 수분을 보충한다는 것이 최근 본 연구진의 연구를 통해 밝혀졌다. 물방울에서 획득된 수분은 진드기 침샘의 포도상 부위(유형 I) 또는 중장을 통해 체내로 흡수된다는 것이 형광물질 추적을 통해 확인되었다. 이 연구 결과는 진드기 방제 및 병원체 전파 억제를 위한 전략 개발에 새로운 방향을 제시하였다. 본 종설에서는 진드기 방제를 위한 잠재적 표적인 진드기의 수분조절 및 표피 배설의 생리적 메커니즘을 종합적으로 다 룬다.

Fluorescent nanostructures based on carbon, or carbon dots, are attracting much attention and interest because of their diverse properties which can be applied in several fields of knowledge, such as optics, biomedicine, environmental research, among others. Such properties are in part, derived from its intrinsic luminescence from tunable functional groups. In this work, we produced carbon nanodots (CND) using agro-industrial residues, such as Lolium perenne and malt bagasse. The methods used were conventional hydrothermal syntheses and microwave-assisted hydrothermal synthesis. To the best of our knowledge, this is the first time that carbon dots synthesized from this ryegrass type are reported. The synthesis methods were one step (no catalyst, base, or acid were added for passivation), and the functional groups responsible for the luminescence and high solubility in water were identified by infrared spectroscopy, being mainly C=O, C–OH, C–N, and N–H. According to our theoretical studies, the C=O group introduced a new energy level for electronic transitions that can affect the emission properties. Fluorescence images of osteoblasts using CNDs were acquired and their chelating property towards Pb2+ and Cr6+ detection was tested.

Copper nanoparticles (CuNPs) are considered of great importance due to their high catalytic and antimicrobial activities. This study focuses on the preparation and characterization of CuNPs, and on their antibacterial/antifungal activities. A copper salt (copper sulfate pentahydrate) as precursor, starch as stabilizing agent, and ascorbic acid as reducing agent were used to fabricate CuNPs. The resulting product was characterized via different techniques such as X-ray diffractrometry (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning electron microscopy (SEM) to confirm its characteristic properties. Employing the Scherrer formula, the mean crystallite sizes of copper (Cu) and cuprous oxide (Cu2O) nanocrystals were found to be 29.21 and 25.33 nm, respectively, as measured from the main X-ray diffraction peaks. The functional groups present in the resulting CuNPs were confirmed by FTIR. In addition, the engineered CuNPs showed antibacterial and antifungal activity against tested pathogenic bacterial and fungal strains.

In this article, Pb2Ba1.7Sr0.3Ca2Cu3O10+δ superconductor material was synthesized using conventional solid-state reaction method. X-ray diffraction (XRD) analysis demonstrated one dominant phase 2223 and some impurities in the product powder. The strongest peaks in the XRD pattern were successfully indexed assuming a pseudo-tetragonal cell with lattice constants of a = 3.732, b = 3.733 and c = 14.75 Å for a Pb-Based compound. The crystallite size and lattice strain between the layers of the studied compound were estimated using several methods, namely the Scherrer, Williamson-Hall (W.H), sizestrain plot (SSP) and Halder Wagner (H.W) approach. The values of crystallite size, calculated by Scherrer, W.H, SSP and H.W methods, were 89.4540774, 86.658638, 87.7555823 and 85.470086 Å, respectively. Moreover, the lattice strain values obtained by W.H, SSP and H.W methods were 0.0063240, 0.006325 and 0.006, respectively. It was noted that all crystallite size results are consistent; however, the best method is the size-strain plot because it gave a value of R2 approaching one. Furthermore, degree of crystallites was calculated and found to be 59.003321%. Resistivity analysis suggests zero-resistance, which is typical of superconducting materials at critical temperature. Four-probe technique was utilized to measure the critical temperature at onset Tc(onset), zero resistivity Tc(off set), and transition (width ΔT), corresponding to temperatures of 128 K, 116 K, and 12 K, respectively.

The mercury ion ( Hg2+) is regarded as one of the toxic cations that is extremely harmful and dangerous to human health and the environment. With this growing awareness, it is imperative that facile and rapid sensing systems developed for the detection of Hg2+. Due to excellent sensitivity and selectivity, graphene quantum dots (GQDs), a zero-dimensional carbon nanomaterial, are attracting the attention of researchers as promising candidates as fluorescent probes for Hg2+ detection. This study aimed at conducting an in-depth review of recent advances into GQD-based materials as fluorescent probes in Hg2+ sensing. This systematic review was carried out by covering three main databases, namely, Scopus and Science Direct as the dominant databases, followed by Google Scholar as the supporting database. GQD-based materials encompassing bare GQDs, N-GQDs, B, N-GQDs, N, S-GQDs, N, K-GQDs, RhB-GQDs, Cys-GQDs, PEHA-GQD-DPA, Gly-GQDs, Mn(II)-NGQDs, NH2– Ru@ SiO2- NGQDs and FA-GQDs were discussed thoroughly with regard to their synthesis strategies, along with their potential application in the detection of Hg2+. The doping of heteroatoms is envisaged to enhance the quantum yield and selectivity of bare GQDs. This review might unlock a wide range of opportunities for the application of various GQD-based materials as an adaptable, feasible and scalable approach to the detection of Hg2+.

일상적인 화학제품들의 사용량이 증가함에 따라 사용되었던 염료 폐기물 처리 또한 중요한 환경 적인 문제로 대두되었다. 이러한 염료폐기물은 광촉매를 이용하여 분해시킬 수 있는데, 졸-겔 기술을 활용 하면 매우 비용 효율적으로 광촉매를 합성할 수 있다. 졸-겔 기술은 나노스케일의 막 형성에도 상당히 유 용하며 간단하게 다층구조를 형성할 수도 있다. 본 연구에서는 다양한 염료 분해에 효과가 있는 산화아연 (ZnO) 이용하여 다중 회전도포 방법으로 다층구조(3층, 5층)를 가진 ZnO 막을 형성하였다. 성능비교를 위해 단일 회전도포 방법에 의한 단층구조를 가진 ZnO 막을 대조군으로 준비하였다. X선 회절분석기 및 에너지 분산 X선 분광계를 이용하여 ZnO의 구조 및 원소분석을 수행하였고, 주사전자현미경을 통해 나노 선같은 표면형상을 관찰할 수 있었다. 추가적으로 UV-Vis 분광광도계를 활용하여 자외선의 흡수도를 측정 하였다. 5층구조를 가진 ZnO 막이 단층 구조를 가진 ZnO 막에 비해 모의 메틸렌 블루를 49% 더 많이 분해하였다. 결론적으로, 다층구조를 가진 ZnO 는 메틸렌블루 염료를 더욱 효과적으로 분해하는 광촉매로 써 유용하다는 알 수 있었다.

Carbon xerogels (CXs) with three-dimensional (3D) structure, unusual surface, physical, electrical and mechanical properties and their electrically conductive polymer polypyrrole (PPy) composites were synthesized as electrode materials for supercapacitors. The effect of different resorcinol/formaldehyde (R/C) ratios, whether solvent exchange with or without acetone and polypyrrole addition on the physicochemical (FTIR, XRD, BET, SEM and TGA) and electrochemical properties (CV, 1000 cycles) of the synthesized materials were investigated. It was observed that the R/C ratio and the solvent exchange process prior to drying affect the specific surface areas and the pore size distributions, thereby positively affecting the specific capacitance. PPy film thickness was observed to be effective in the specific capacitance of the electrode in PPy composite synthesis. Among the synthesized materials, the highest specific capacitance values belong to polypyrrole/carbon xerogel composites. As a result of the analysis and calculations, it was found that the highest specific capacitance belongs to CX2/PPy composite with 599 Fg− 1 at 5 mVs− 1. CX2/PPy composite has been found to have a capacitance retention rate of 80.30% at the end of 1000 cycles.

Green synthesis of graphene using leaf extracts as sustainable reducing and capping agents is a thrust area of research owing to its simplicity, eco-friendly nature and the ease of access to graphene. Moringa (Moringa oleifera Lam) plant is widely cultivated in India owing to its important medicinal and nutritional values. Inspired by these reports, herein we report a simple, green and economic synthesis of graphene, Moringa leaf extract employed reduced graphene oxide (MRGO) with excellent dye removal efficiencies. The MRGO is prepared by refluxing a mixture of aqueous dispersion of graphene oxide and Moringa leaf extract for 10 h. Further, we elucidated the role of synthesized MRGO in the removal of methylene blue (MB) and rhodamine B (RB) dyes through the sonochemical method. This as-synthesized material exhibited excellent dye removal efficiencies of about 93% and 87% against MB and RB dyes, respectively. Graphene with huge surface area expedited the better adsorption of dye molecules, thus, facilitated the better removal of the latter. Therefore, the superior dye removal efficiencies of MRGO were attributed to its adsorption capacity. This cost-effective synthetic approach of MRGO nanomaterial has a great potential for the innovative applications in water purification technology and find its place in further industrialization.

Anion assisted [4 + 2] cycloaddition reaction via indolo[2,3]-dienolate by reacting 1,2-dimethylindole-3-carboxaldehyde with aromatic nitriles using lithium diisopropylamide in terahydrofuran, a facile and convenient regiospecific route designed and developed for the synthesis of γ-carbolines.