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Effect of solidification cooling rate on microstructure and tribology characteristics of Zn-4si alloy

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 362-373页

作者： F.Akbari M.Golkaram s.Beyrami G.shirazi k.Mantashloo R.Taghiabadi M.saghafi Yazdi I.Ansarian Department of Metallurgy and Material science Imam Khomeini International University(IKIU)Qazvin ***Iran

The main objective of this work was to modify the microstructure and enhance the tribological properties of a new Zn-4si al-loy through a high solidification cooling rate(sCR).According to the results,by increasing the sCR from 2.0 to 59.5℃/s the average size of primary si particles and that of the grains reduced from 76.1 and 3780μm to less than about 14.6 and 460μm,***-ing the sCR also enhanced the microstructural homogeneity,decreased the porosity content(by 50%),and increased the matrix hardness(by 36%).These microstructural changes enhanced the tribological *** instance,under the applied pressure of 0.5 MPa,an in-crease in the sCR from 2.0 to 59.5℃/s decreased the wear rate and the average friction coefficient of the alloy by 57%and 23%,*** wear mechanism was also changed from the severe delamination,adhesion,and abrasion in the slowly-cooled alloy to the mild tribolayer delamination/abrasion in the high-cooling-rate-solidified sample.

关键词： zinc-silicon alloy primary silicon solidification cooling rate tribology sliding wear

Cybersecurity system to Detect Phishing Attack and Possible Classification of spam and smishing sMs Using Deep Learning Algorithm

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Journal of Harbin Institute of Technology(New series) 2024年

作者： k Gowri s Brindha Department of Computer science， st.Peters Institute of Higher Education And Research Department of Computer science and Application， st.Peters Institute of Higher Education And Research

Phishing threats， especially those sent via sMs (known as smishing)， are a big worry in the digital world. so better ways are needed to fight against phishing because cybercriminals.k.ep changing their tactics. This study aims to make the online systems safer by using advanced technology called deep learning ， specifically a method called the AlexNet-LsTM algorithm， to sort out smishing messages effectively. Phishing vulnerability depends on different things such as age， gender， how much time someone spends online， and how stressed they are. In this study， deep learning is used to find sMs threats， and different types of text-based attacks are figured out by using the AlexNet-LsTM algorithm. To evaluate the superiority of this new method and how well it performs， it is compared with traditional methods such as logistic regression， random forest， and support vector machine. The results show a big improvement in accuracy， up to 99.6%， proving the efficacy of deep learning to make the online systems safer against various tricky attacks.

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Organic-inorganic hybrid materials and architectures in optoelectronic devices: Recent advancements

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ChemPhysMater

ChemPhysMater 2024年第3期3卷 252-272页

作者： M.Arya s.Heera P.Meenu k.G.Deepa Department of Physics University of KeralaThiruvananthapuram 695581India Department of Nanoscience and Nanotechnology University of KeralaThiruvananthapuram 695581India

Organic-inorganic hybrids are next-generation materials for use in high-performance optoelectronic devices owing to their adaptabilities in terms of design and *** article reviews the application of hybrid materials and layers in several widely used optoelectronic devices,i.e.,light amplification by stimulated emission of radiation(LAsER),solar cells,and light-emitting diodes(LEDs).The effects of the incorporation of inorganic particles on photostability and optical gain are analyzed in the first section with reference to dye and perovskite ***,the strategies used in blending inorganic nanostructures into organic solar cells and bulk heterojunctions are *** use of various organic layers as electron-and hole-transport materials in si heterojunction solar cells is reviewed in ***,the benefits of the presence of organic components in quantum-dot-and perovskite-based LEDs are derived from the *** integration of organic and inorganic components with optimal interfaces and morphologies is a challenge in developing hybrid materials with improved efficiencies.

关键词： Optoelectronics Hybrid material Device performance Photostability Advantages

Influence of Formulation and Hot-Pressing Conditions on the Performance of Bio-Based Molasses Adhesive for Plywood

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Journal of Renewable Materials 2024年第8期12卷 1383-1397页

作者： sutiawan J. syahfitri A. kusumah s.s. Hermawan D. sari R.k. Hakim L. Mardawati E. Lubis M.A.R. Research Center for Biomass and Bioproducts National Research and Innovation Agency Cibinong 16911 Indonesia Forest Product Department Faculty of Forestry and Environment IPB University Bogor 16680 Indonesia Department of Forest Products Faculty of Forestry Universitas Sumatera Utara Medan 20155 Indonesia Research Collaboration Center for Biomass and Biorefinery BRIN and Universitas Padjadjaran Bandung 40600 Indonesia Department of Agro-Industrial Technology Universitas Padjadjaran Bandung 40600 Indonesia

Molasses can serve as a natural adhesive for plywood and particleboard. However, several disadvantages remain, including lower dimensional stability and low bonding strength compared to other adhesives. Therefore, modifications are needed to use molasses as an adhesive for plywood. This research aims to improve bio-based molasses (MO) adhesive for plywood using citric acid (CA) adhesive. In addition, this research aims to analyze the effect of adding citric acid and to investigate the optimum hot-pressing temperature to produce the best quality plywood. In the first stage, the molasses and citric acid were combined in a ratio of 100:0, 75:25, 50:50, 25:75, 0:100 w/w%. Then, the second stage focuses on analyzing the influences of pressing temperature based on an optimum first stage. The research demonstrated that the addition of CA altered the gelation time, solid content, visc-osity, and pH of the molasses adhesives. In addition, the thermal properties of molasses adhesives were changed after mixing with citric acid. These phenomena indicate changes in characteristics, such as the curing of adhesive. Overall, the characteristics of plywood showed a steady improvement as the CA ratio increased but revealed a significant decline for the 25:75 MO-CA ratio. By raising the pressing temperature from 180°C to 200°C, the quality of plywood was effectively improved. The plywood that was bonded using adhesives with a 50:50 MO-CA ratio exhibited superior mechanical properties and improved dimensional stability compared to the plywood bonded solely with MO. Furthermore, the optimal mechanical and physical properties resulted in plywood bonded with a 50:50 MO-CA ratio when subjected to a pressing temperature of 200°C. The Thermal and FTIR measurements revealed that CA established ester bonds with both the MO and wood veneers. In conclusion, the mechanical characteristics of plywood were improved, while maintaining its excellent dimensional stability. © 2024 The Authors.

关键词： Citric acid composite molasses plywood pressing temperature

Effects of sr^(2+) substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第2期21卷 175-180页

作者： Arvind kumar s.k. Mishra Research and Technology Development Centre Sharda University

This study described the structural, dielectric, and piezoelectric behavior of Pb1-xsrx[（Zr0.52Ti0.48）0.95（Mn1/3Nb2/3）0.05]O3 ceramics （PsZT-PMN, x=0, 0.025, 0.050, and 0.075）, prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a sr2＋-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary （MPB）. Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients （d33） value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the sr2＋concentration increases in the PZT-PMN ceramics.

关键词： ceramic materials strontium substitution structural properties dielectric properties piezoelectricity

The autophagy protein Atg9 functions in glia and contributes to parkinsonian symptoms in a Drosophila model of Parkinson’s disease

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Neural Regeneration Research 2024年第5期19卷 1150-1155页

作者： shuanglong Yi Linfang Wang Margaret s.Ho shiping Zhang school of Life science and Technology ShanghaiTech UniversityShanghaiChina College of Life sciences University of Chinese Academy of SciencesBeijingChina

Parkinson’s disease is a progressive neurodegenerative disease characterized by motor deficits,dopaminergic neuron loss,and brain accumulation ofα-synuclein aggregates called Lewy *** in protein degradation pathways,such as autophagy,has been demonstrated in neurons as a critical mechanism for eliminating protein aggregates in Parkinson’s ***,it is less well understood how protein aggregates are eliminated in glia,the other cell type in the *** the present study,we show that autophagy-related gene 9(Atg9),the only transmembrane protein in the autophagy machinery,is highly expressed in Drosophila glia from adult *** from immunostaining and live cell imaging analysis reveal that a portion of Atg9 localizes to the trans-Golgi network,autophagosomes,and lysosomes in ***9 is persistently in contact with these *** glial atg9 reduces the number of omegasomes and autophagosomes,and impairs autophagic substrate *** suggests that glial Atg9 participates in the early steps of autophagy,and hence the control of autophagic ***,loss of glial atg9 induces parkinsonian symptoms in Drosophila including progressive loss of dopaminergic neurons,locomotion deficits,and glial *** findings identify a functional role of Atg9 in glial autophagy and establish a potential link between glial autophagy and Parkinson’s *** results may provide new insights on the underlying mechanism of Parkinson’s disease.

关键词： Atg9 autophagy glia Parkinson’s disease

In vivo and in vitro study of resorbable magnesium wires for medical implants:Mg purity,surface quality,Zn alloying and polymer coating

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Journal of Magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： k.Tesar J.Luňácková M.Jex M.Žaloudková R.Vrbová M.Bartoš P.klein L.Vištejnová J.Dušková E.Filová Z.sucharda M.steinerová s.Habr k.Balík A.singh Department of Materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental Medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon Materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for structural Materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

Magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of Mg-based *** low-alloyed Mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure Mg,commercially pure Mg,Mg-0.15Zn,Mg-0.4Zn and Mg-1Zn was ***,Mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed Mg-induced osteogenesis,polymer-coated Mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： Magnesium Resorbable Mg wire Mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

Therapeutic methods for diarrhea in children

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World Journal of Gastroenterology 2000年第4期6卷 497-500页

作者： s.k. Bhattacharya Director National Institute of Cholera and Enteric DiseasesP-33CIT Road.Scheme XMBeliaghataCalcutta 700010INDIA

DEFINITIONAcute diarrhoea is defined as passage of loose or waterystools at least three times in a 24 h *** loosestools contain blood,it is called bloody diarrhoea(dysentery).It is the consistency of the stools which ismost important rather than the ***-fed babiesoften pass'pasty'stools frequently which is not *** raother can often tell accurately whether child hasdiarrhoea or not.

关键词： diarrhea infantile/therapy dehydration antibiotics infusion intravenous water-electrolyte balance antidiarrheals nutritional requirements

Isolation of Microcrystalline Cellulose from Wood and Fabrication of Polylactic Acid (PLA) Based Green Biocomposites

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Journal of Renewable Materials 2024年第8期12卷 1455-1474页

作者： s.k.r s.M. Nagarajan R. selvakumar P. Oluwarotimi I.s. krishnan k. Mohammad F. shaik M.R. Ayrilmis N. Department of Mechanical Engineering Kalasalingam Academy of Research and Education Krishnankoil 626126 India Department of Mechanical Engineering SSM Institute of Engineering and Technology Dindigul 624002 India Department of Engineering Centre for Engineering Research School of Physics Engineering and Computer Science University of Hertfordshire Hatfield AL10 9AB United Kingdom INTI International University Persiaran Perdana BBN Nilai 71800 Malaysia Department of Chemistry College of Science King Saud University P.O. Box 2455 Riyadh 11451 Saudi Arabia Department of Wood Mechanics and Technology Faculty of Forestry Istanbul University–Cerrahpasa Bahcekoy Sariyer Istanbul 34473 Turkey

An innovative microcrystalline cellulose (MCC) natural fibre powder-reinforced PLA biocomposite was investigated using the hand lay-up technique. The polymer matrix composite (PMC) samples were prepared by varying the weight percentages (wt.%) of both PLA matrix and MCC reinforcement: pure PLA/100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 wt.%, respectively. From the results obtained, MCC powder, with its impressive aspect ratio, proved to be an ideal reinforcement for the PLA, exhibiting exceptional mechanical properties. It was evident that the 80:20 wt.% biocomposite sample exhibited the maximum improvement in the tensile, flexural, notched impact, compressive strength and hardness by 28.85%, 20.00%, 91.66%, 21.53% and 35.82%, respectively compared to the pure PLA sample. similarly, during the thermogravimetric analysis (TGA), the same 80:20 wt.% biocomposite sample showed a minimum weight loss of 20% at 400°C, among others. The morphological study using Field Emission scanning Electron Microscopy (FE-sEM) revealed that the uniform distribution of cellulose reinforcement in the PLA matrix actively improved the mechanical properties of the biocomposites, especially the optimal 80:20 wt.% sample. Importantly, it was evident that the optimal PLA/cellulose biocomposite sample could be a suitable and alternative sustainable, environmentally friendly and biodegradable material for semi/structural applications, replacing synthetic and traditional components. © 2024 The Authors.

关键词： biocomposite characterizations environmental pollution FEsEM micro crystalline cellulose Polylactic acid