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1
Holovko, V. "NANOMODIFICATION OF WELD METAL DENDRITE STRUCTURE." Deutsche internationale Zeitschrift für zeitgenössische Wissenschaft 48 (January 16, 2023): 41–46. https://doi.org/10.5281/zenodo.7541168.
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The shape of dendrite grains in low-alloy steel submerged-arc weld deposits has been examined; it is found that the dendrite grain morphology can be modified because of dispersed refractory inclusions inoculation in the weld pool. Influences of inoculated inclusions on dendrites grain size are also discussed. An increase in the dendrite size has been found to increases content of toughness ferrite structure in weld met
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Zhang, Jing, Zhou Yi Pang, Chi Chi Sun, Ning Liu, and Hong Mei Chen. "Effect of Strontium Modification on the Morphology of Primary Si in Hypereutectic Al-Si Alloys." Materials Science Forum 993 (May 2020): 12–21. http://dx.doi.org/10.4028/www.scientific.net/msf.993.12.
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In the present study, hypereutectic Al-Si alloys were modified by strontium and the effect of the strontium content and holding time on the morphology of primary Si was investigated. Primary Si is modified to imperfect octahedron with primary dendrites or secondary dendrites when the amount of Sr exceeds 0.04wt.%. With extending the holding time, there is no significant difference with the morphology of primary Si. However, the size of primary Si decreases remarkably when the holding time prolongs to 120min. Further analysis reveals that the Sr content has a considerable impact on the morphology of primary Si due to growth mechanism influence, while the modifying time mainly influences the size of primary Si.
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Maniara, Rafal, Leszek Adam Dobrzański, Jerry Sokolowski, Wojciech Kasprzak, and Witold T. Kierkus. "Influence of Cooling Rate on the Size of the Precipitates and Thermal Characteristic of Al-Si Cast Alloys." Advanced Materials Research 15-17 (February 2006): 59–64. http://dx.doi.org/10.4028/www.scientific.net/amr.15-17.59.
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In this work effect of cooling rate on the size of the grains, SDAS, β phases and thermal characteristic results of Al-Si cast alloys have been described. The solidification process was studied using the cooling and crystallization curve at cooling rate ranging from 0,1 °Cs-1 up to 1 °Cs-1. The main observation made from this work was that when cooling rate is increased the aluminum dendrites nucleation temperature and solid fraction at the dendrite coherency point increases, which implies that mass feeding is extended. In addition to that, it was observed that solidus temperature and size of the β phases decreases when cooling rate increases. Investigations were showed, that the thermal modification could be quantitatively assessed by analysis of the crystallization curve.
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Chen, Zhong Wei, Hai Fang Zhang, and Jiang Chao Zhao. "Electron Back Scattering Diffraction Analysis of A357 Alloy Modified by Sr." Advanced Materials Research 160-162 (November 2010): 831–35. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.831.
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Microstructure of A357 alloy modified by Sr has been investigated by the Electron Back Scattering Diffraction (EBSD) mapping technique using a Field Emission Gun Scanning Electron Microscopy (FEG-SEM). An appropriate sample preparation technique by ion milling was applied to obtain a sufficiently smooth surface for EBSD mapping. Results show that the eutectic morphology in microstructure of A357 alloy modified by Sr was changed to fine fibrous, and the grain size was refined. By comparing the orientation of the aluminum in the eutectic to that of the primary aluminum dendrites, the nucleation and growth mechanism of the eutectic solidification in A357 cast alloy was determined. The eutectic Si phase of the modified sample nucleates on the heterogeneous nuclei located in the region between primary α-Al dendrites and grows up, while the eutectic Si phase of the sample without modification nucleates on the primary α-Al dendrites and grows up.
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Promakhov, Vladimir, Marina Khmeleva, Ilya Zhukov, Vladimir Platov, Anton Khrustalyov, and Alexander Vorozhtsov. "Influence of Vibration Treatment and Modification of A356 Aluminum Alloy on Its Structure and Mechanical Properties." Metals 9, no. 1 (2019): 87. http://dx.doi.org/10.3390/met9010087.
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A series of casting experiments was conducted with A356 aluminum alloys by applying vibration treatment and using Al-TiB2 composite master alloys. The main vibration effects include the promotion of nucleation and a reduction in as-cast grain size. Using composite master alloys with titanium diboride microparticles allows further reduction in the average grain size to 140 µm. The reasons for this behavior are discussed in terms of the complex effect on the melt, considering the destruction of dendrites, and the presence of additional crystallization centers. Tensile tests were performed on the samples obtained during the vibration treatment and with titanium diboride particles. The tensile strength increased from 182 to 227 MPa after the vibration treatment for the alloys containing titanium diboride.
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Liu, Niu Can, Guang Sheng Kang, and Zhong Xia Liu. "Study on Microstructure and Impact Toughness of In Situ Mg2Si Particle Reinforced Al-Si Matrix Composites." Advanced Materials Research 557-559 (July 2012): 215–18. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.215.
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The microstructure and impact toughness of in-situ Mg2Si/Al-Si composites were studied in the different content of Sb. The results show that Sb can improve the microstructure and impact toughness of Mg2Si/Al-Si composites. When the content of Sb is 0.4%, the morphology of primary Mg2Si changes from dendrites to fine particles, the average size of Mg2Si particles is refined from 52μm to 25μm, and the impact toughness of the composites increases from 6.3572J/cm2 to 11.4394J/cm2. The improvement of impact toughness can be attributed to the fine-grain strengthening. However, excessive Sb is disadvantageous to the modification of the composites.
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Yang, Xiong, Shu Sen Wu, Shu Lin Lü, Liang Yan Hao, and Xiao Gang Fang. "Modification of LPSO Structure in Mg-Ni-Y Alloy with Strontium." Materials Science Forum 941 (December 2018): 869–74. http://dx.doi.org/10.4028/www.scientific.net/msf.941.869.
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Effects of Sr levels on microstructure of the LPSO structure-containing Mg98.5-xNi0.5Y1.0Srx(x=0, 0.05, 0.10, 0.20 at.%) alloy were studied by SEM/EDS and XRD. Without Sr addition, the Mg98.5Ni0.5Y1.0alloy consists of α-Mg and LPSO structure and the block LPSO structure is distributed along the grain boundary. After adding 0.05 at.% Sr element into Mg98.5Ni0.5Y1.0alloy, the amount of dendrites decreased. With the increase of Sr content, the size of α-Mg grains decreases firstly and then increases. Meanwhile, the LPSO structure is refined. The addition of Sr element also results in the obvious increment of the amount of lamellar structure, which stretched from the grain boundary to the matrix. The excessive Sr in high Sr-content alloys participates in the form of Mg-Ni-Y-Sr compound, which is distributed in the vicinity of LPSO structure. In addition, the Sr can also promote the formation of Ni-rich and Y-rich phases.
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Davoisne, Carine, Neelam Yadav, and Mathieu Morcrette. "Failure Modes in Sulfide-Based All Solid-State Batteries (ASSB) Investigated By Operando SEM." ECS Meeting Abstracts MA2023-02, no. 3 (2023): 474. http://dx.doi.org/10.1149/ma2023-023474mtgabs.
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Studies on solid state batteries (ASSB) which began back in 190’s has seen a tremendous growing interest for multiple reasons such as the safety and the ability to use the metallic anodes for enhancing the gravimetric energy density. However, it exists different issues linked with poor performance of the batteries, which could be the results of interfacial challenges such as poor ion transport, dendrite formation, electrochemical degradation and chemo-mechanical degradation[1]. Among the potential parameters impacting the cycling process, the influence of the particle size of solid electrolyte is not well studied. In this study, we focused on sulfide-based SEs particle size distribution and its impact on electrochemical performance by investigating from the morphological point of view via operando SEM. A batch of Argyrodite (Li6PS5Cl (LPSCl)) was sieved to obtain two batches of particles range (0,5-20µm and 50-150µm). The AASBs were prepared using the two particles size distribution while keeping the anode (lithium metal), cathode (MA: NMC) composite formation and the fabrication process constant. The different morphological and chemical evolutions were monitored in real time by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDX) to obtain a complete of the different modification throughout the battery components and their interfaces. To do so, a home-made electrochemical cell was developed to perform in-situ and operando cycling in the SEM. From the two particles sized distribution, the one with the large particles have better electrochemical performance. From morphological point of view at the cathode composite electrode, the formation of a cathode electrolyte interface is visible in the different batteries but is more developed in the case of small sized particles. In the solid electrolyte, the type of cracks differs with relatively strait feature for small particles and sinuous one for large one. At the anodic interface, a lost in contact between the SE separator and the lithium is observed and increased with the cycling process with a higher impact for the small particles (Figure 1.a and b). By investigating further, the formation of dendrites with different morphologies are visible at the anodic interfaces (Figure1.c). We categorized the observed changes into three modes: (i) electrical failure by the formation of lithium dendrites of different morphologies following the ES going up to short circuit in the case of small particles, (ii) mechanical failure by the formation of cracks in the electrolyte whose shape and propagation strongly depend on the distribution particles size and (iii) electrochemical failure with the formation of solid electrolyte interphases on the surface of the active material. The main obstacles for the use of lithium metal are related to the propagation of lithium dendrites and thus to the mechanical instability of solid electrolytes.
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Tiedje, Niels Skat, Jesper Henri Hattel, John A. Taylor, and Mark A. Easton. "Modelling Eutectic Growth in Unmodified and Modified Near-Eutectic Al-Si Alloy." Materials Science Forum 765 (July 2013): 160–64. http://dx.doi.org/10.4028/www.scientific.net/msf.765.160.
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A numerical model that describes solidification of primary aluminium grains and nucleation and growth of eutectic cells is used to analyse the solidification of an Al-12.5wt% Si alloy. Nucleation of eutectic cells is modelled using an Oldfield-type nucleation model where the number of nuclei in the melt is determined by the amount of active nuclei and the local undercooling from the surface to the centre of a plate casting. Eutectic grains are modelled as spheres growing between the dendrites. The growth velocity of the eutectic cells is a function of undercooling. Experimentally determined growth parameters from the literature that depend on the type of modification (unmodified, Na-modified or Sr-modified) are used to describe differences in growth of the alloys. Modelling results are compared with solidification experiments where an Al-12.5wt%Si alloy was cast in unmodified, Na modified and Sr modified forms. The model confirms experimental observations of how modification and alloy composition influence nucleation, growth and finally the size of eutectic cells in the alloys. Modelling results are used to explain how cooling conditions in the casting act together with the nuclei density in the liquid and the growth velocity of the eutectic cells to determine the size and distribution of eutectic cells in the solidified material.
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Ma, Dou Qin, Jing Pei Xie, and Wen Yan Wang. "Effect of Modification on Mechanical Behavior of ZA303 under High Temperature." Materials Science Forum 704-705 (December 2011): 1079–82. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.1079.
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In this paper , by SEM、EDS、XRD and Shimadzu AG-I250KN precision universal testing machine , the metallurgical structure, fracture appearance, the mechanical properties of the ZA303 under high temperature were systematically studied .The results shows that :The microstructure of ZA303 at room temperature are : α phase + (α＋η) eutectoid + ε phase + η phase. After adding modifying elements B、Ti in ZA303：the microstructure of the alloy is from gross dendrites to uniform equiaxed grains , the quantity, morphology and distribution of the (α + η) have greatly change: the quantity of (α + η) is less, from a continuous network to intermittent block, and its end become blunt, or even cylindrical horn and dispersed distribution; on the grain boundary, the size of ε phase become smaller and dispersed distribution, the number of mesh ε phase reduced but intermittent strips increased; adding B、Ti have a good effect of restraining Al element segregation，so the foundry defects decreased obviously. In the range of experimental temperature, the increase of ductility is large while the tensile strength is small: at the same time, the mechanical performances stability is better than that without modification.
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Jing, Qing Xiu, Geng Feng Deng, and Yong Liang. "Modification Microstructures in In Situ Mg2Si Reinforced Al-Si Alloy Composites." Advanced Materials Research 139-141 (October 2010): 718–22. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.718.
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Effects of several different additions on microstructures in in-situ Mg2Si/A1-Si composites were investigated. The results show that rare earth elements have a selective modification effect on eutectic Mg2Si and Si structures. Al-Ti-B modifier should be introduced appropriately more into the composite, so as to effectively refine primary α-Al grains. As (SrCl2+RE) added increases from 0.4wt% to 2.0wt%, morphology of primary Mg2Si in a 12.0Mg2Si/A1-7.6Si composite is changed from polyhedron (or octahedron) to more irregular polyhedron with a size decrease from about 21μm to 6μm, while eutectic Mg2Si is changed from coarse dendrites to dispersed slim fibers. (RE+Al-P) can improve microstructures and tensile strength of a 7.9Mg2Si/A1-7.8Si composite; after modified by 0.8wt% (RE+Al-P), fracture surface of the composite is changed from cleavage to a mixed mode.
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M. Idriss, A. N., and S. Mridha. "Microstructure of TIG Melted Composite Coating on Steel Produced Using 1.0 and 1.5 mg/mm2 TiC at an Energy Input of 2640 J/mm." Advanced Materials Research 576 (October 2012): 467–70. http://dx.doi.org/10.4028/www.scientific.net/amr.576.467.
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Surface modification by reinforcing ceramic particulates can give protection against wear and corrosion of metal. In this work, two different amounts of TiC powder of nominal size 45 to 100 µm were embedded on AISI 4340 steel surfaces by melting under a Tungsten Inert Gas (TIG) welding torch with an energy input of 2640 J/mm. The microstructure, geometry and hardness of the single track composite layers were investigated. The resolidified melt tracks were hemispherical in shape. With increasing TiC content, the melt dimensions reduced a little but the microstructure had a remarkable change. The track with 1.5 mg/mm2 TiC gave more un-melted TiC, partially melted TiC and agglomeration of ceramic particulates while the 1.0 mg/mm2 track dissolved most TiC particulates and precipitated carbides in the form of dendrite, globular and flower type particles; dendrites are almost absent in the 1.5 mg/mm2 track. A reduced TiC addition created more fluid melt which accelerated dissolution of TiC and that caused more carbide precipitation in the 1.0 mg/mm2 track compared to that with 1.5 mg/mm2 track. The 1.0 mg/mm2 track produced lower hardness of 1065 Hv compared to 1350 Hv for the 1.5 mg/mm2 track.
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Khorram, Ali, and Morteza Taheri. "Surface modification of IN713 LC superalloy with Metco 204NS by laser surface alloying." Laser Physics 32, no. 10 (2022): 106001. http://dx.doi.org/10.1088/1555-6611/ac8fe5.
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Abstract Ceramics are one of the best engineering materials for coating gas turbine blades. In this study, the Metco204NS ceramic coating (Zr2O + 8%Y2O3) was applied by the laser surface alloying (LSA) method on IN713 LC nickel-based superalloy. To influence the heat input on the structure of the ceramic coating and its substrate, and as well as the rejuvenated zone (RZ), different variables were used in LSA. The results showed that with an increase in heat input by the laser, the sensitivity to liquation cracks in the heat affected zone and solidification cracks in the RZ decreases. The most important reason for this was the increase in backfilling by the molten metal due to its high fluidity. However, with increasing heat input, the hardness increased due to the reduction of the distance between the dendrites. Solidification rate (R) and temperature gradient (G) were identified as the most important microstructure controlling factors in the RZ. So, with increasing the heat input and thus decreasing G and R, the tendency of the structure to change from cellular to columnar and then equiaxed increased. The uniform and homogeneous coating of Metco 204NS significantly increased the wear resistance of IN713 LC superalloy. The higher hardness and wear resistance of melted Metco 204NS coating material relative to the RZ and the base metal was due to the presence of very hard Zr2O and Y2O3 particles in Metco 204NS and the reduction of grain size.
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Fracchia, Elisa, Federico Simone Gobber, and Mario Rosso. "Effects of Casting-Additives on the Microstructure Evolution of Hypoeutectic Aluminium-Silicon Alloys." Metals 10, no. 5 (2020): 618. http://dx.doi.org/10.3390/met10050618.
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Since the industries are called to produce environmentally friendly products, the research is moving toward new improved materials. In this panorama, aluminium alloys find applications for a large range of products. In the automotive, as well as in the aerospace, sector, aluminium alloys are largely adopted, thanks to their high specific properties and their light weight. Moreover, common casting techniques permit us to realize complex high-quality components. These components may be realized by using casting techniques adopting casting-additives, such as modifiers or refiners. In this work, the effect of refining and modification was studied in terms of microstructural evolution of the intermetallic phases in two aluminium-silicon alloys (EN AC 45300 and EN AC 43500). Microstructures were analyzed through micro-hardness measures, and we found a reduction in the standard deviation of the hardness with the addition of additives. Furthermore, secondary dendrites arms spacings (SDAS) were measured, evidencing a decrease in SDAS by adding casting additives. A strong correlation was found between the adding of additives and the possibility of containing the size of the silicon and of all the intermetallic phases opening up to the possibility of tailoring the microstructures.
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Takashima, Kai, Manabu Kodama, and Shuichiro Hirai. "Performance Improvement of Lithium Metal Anode All-Solid-State Batteries By High-Speed Blowing of Abrasive Grains." ECS Meeting Abstracts MA2022-02, no. 4 (2022): 481. http://dx.doi.org/10.1149/ma2022-024481mtgabs.
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All-solid-state lithium metal batteries (ASSLiMBs) are one of the candidates for a next-generation automotive battery. In particular, oxide-based SEs have relatively high electrochemical stability against lithium metal. Thus, ASSLiMB with oxide SE is expected to be long life and high energy density battery. Poor contact between the lithium metal and oxide SE is an issue to realize ASSLiMB with oxide SE. This poor contact causes high overvoltage at the SE-Li interface, and lithium dendrite grows into the SE, and it reaches to the cathode, then causing a short circuit at high-speed charging that exceeds critical current density (CCD). Several methods (e.g., thin-film insertion method, interface structure modification methods) are proposed to suppress the interface resistance and enhance the CCD; however, more low interface resistance and high CCD is required to achieve high-speed charging by ASSLiMB with oxide SE. In this study, we propose a thin surface structure control method by shot peening (S.P.) to suppress the interface resistance and increase the CCD of ASSLiMB with oxide SE. S.P. is a surface treatment method by blowing abrasive grains with high-pressure air. S.P. has the effect of imparting an uneven surface and compressive residual stresses to the surface. The uneven shape is expected to increase the interfacial stress and improve the contact property as the SE bites into the Li. The compressive residual stresses suppress crack initiation on the SE surface. It has been reported that Li dendrites grow with cracks, and suppression of cracks is expected to improve CCD . The S.P. has above two effects that can improve the lithium metal anode performance, so, we investigated the influence of the S.P. on the lithium metal anode performance. We also investigated the influence of the grain size on the electrode performance because the size of the surface roughness and the compressive residual stresses can be changed by the change of the grain size used in S.P. Pellets of oxide SE (Li6.25Ga0.25La3Zr2O12) synthesized by the solid phase reaction method were processed by S.P. with abrasive grain of Al2O3 powder. After the S.P., the surface of the pellet is coated with gold by gold sputtering. Three experiments with three abrasive gain sizes (50 µm,100 µm,300 µm) and the SE without S.P. were carried out to check the influence of the S.P.. Li metal was attached to both sides of the SE layer to construct a symmetric cell, and CCD measurements and electrochemical impedance spectroscopy measurements were performed. Surface characteristics were measured by surface three-dimensional scanning electron microscopy (surface 3DSEM) and indentation. Fig. 1 shows the CCD and interfaces resistance without S.P. and S.P. using each abrasive grain. As shown in the figure, higher CCD and low interface resistance are achieved for the samples with S.P. with 50 µm, and 100 µm grain size than non S.P. processed samples. On the other hand, the CCD of S.P. with 300 µm grain is almost the same as the non S.P. processed samples and the interface resistance is high. These results indicate that the S.P. can improve electrode performance, and there is an optimum S.P. grain size. From indentation, the fracture toughness of S.P. processed samples were higher than a sample without S.P., and the fracture toughness increased with increasing in grain diameter. This increase in fracture toughness may have suppressed the growth of Li dendrites into the SE, leading to an increase in CCD. The surface 3DSEM showed that the S.P. creates an uneven pattern on the SE pellet and the structure size is several µm. The structure size increases with the increase in the abrasive grain size. This unevenness improves the contact between SE and Li and suppresses the interface resistance. This interface resistance suppression depends on the structure size, and the lowest interface resistance is achieved for the S.P. with the smallest grain size of 50 µm. As a result of the balance between high compressive residual stress by small size grain and the low interface resistance by large size grain, the highest CCD is obtained by middle size grain of 100 µm. This study shows that S.P. can decrease the interfacial resistance of ASSLiMB and improve CCD. The unevenness caused by S.P. is on the order of several micrometers, and it can be said that S.P. can be applied to separators thinner than 100 micrometers. Figure 1
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Poudel, Dhruba P., and Richard T. Taylor. "Thiol-Ene Click-Inspired Late-Stage Modification of Long-Chain Polyurethane Dendrimers." Reactions 3, no. 1 (2021): 12–29. http://dx.doi.org/10.3390/reactions3010002.
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The construction of well-defined polyurethane dendrimers is challenging due to the high reactivity of externally added or in situ formed isocyanates leading to the formation of side products. With a primary focus of dendrimer research being the interaction of the periphery and the core, we report the synthesis of a common polyurethane dendron, which allows for the late-stage variation of both the periphery and the core. The periphery can be varied simply by installing a clickable unit in the dendron and then attaching to the core and vice-versa. Thus, a common dendron allows for varying periphery and core in the final two steps. To accomplish this, a protecting group-free, one-pot multicomponent Curtius reaction was utilized to afford a robust and versatile AB2 type polyurethane dendron employing commercially available simple molecules: 5-hydroxyisophthalic acid, 11-bromoundecanol, and 4-penten-1-ol. Subsequent late-stage modifications of either dendrons or dendrimers via a thiol-ene click reaction gave surface-functionalized alternating aromatic-aliphatic polyurethane homodendrimers to generation-three (G3). The dendrons and the dendrimers were characterized by NMR, mass spectrometry, and FT-IR analysis. A bifunctional AB2 type dendritic monomer demonstrated this approach’s versatility that can either undergo a thiol-ene click or attachment to the core. This approach enables the incorporation of functionalities at the periphery and the core that may not withstand the dendrimer growth for the synthesis of polyurethane dendrimers and other dendritic macromolecules.
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Parashar, Ashish K., Preeti Patel, Arun K. Gupta, Neetesh K. Jain, and Balak Das Kurmi. "Synthesis, Characterization and in vivo Evaluation of PEGylated PPI Dendrimer for Safe and Prolonged Delivery of Insulin." Drug Delivery Letters 9, no. 3 (2019): 248–63. http://dx.doi.org/10.2174/2210303109666190401231920.
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Background: The present study was aimed at developing and exploring the use of PEGylated Poly (propyleneimine) dendrimers for the delivery of an anti-diabetic drug, insulin. Methods: For this study, 4.0G PPI dendrimer was synthesized by successive Michael addition and exhaustive amidation reactions, using ethylenediamine as the core and acrylonitrile as the propagating agent. Two different activated PEG moieties were employed for PEGylation of PPI dendrimers. Various physicochemical and physiological parameters UV, IR, NMR, TEM, DSC, drug entrapment, drug release, hemolytic toxicity and blood glucose level studies of both PEGylated and non- PEGylated dendritic systems were determined and compared. Results: PEGylation of PPI dendrimers caused increased solubilization of insulin in the dendritic framework as well as in PEG layers, reduced drug release and hemolytic toxicity as well as increased therapeutic efficacy with reduced side effects of insulin. These systems were found to be suitable for sustained delivery of insulin by in vitro and blood glucose-level studies in albino rats, without producing any significant hematological disturbances. Conclusion: Thus, surface modification of PPI dendrimers with PEG molecules has been found to be a suitable approach to utilize it as a safe and effective nano-carrier for drug delivery.
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Amjad, A. M. "DENDRIMERS IN ANTICANCER TARGETED DRUG DELIVERY: ACCOMPLISHMENTS, CHALLENGES AND DIRECTIONS FOR FUTURE." Pharmacy & Pharmacology 9, no. 1 (2021): 4–16. http://dx.doi.org/10.19163/2307-9266-2021-9-1-4-16.
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Dendrimers are nanoparticles with unique features including globular 3D shape and nanometer size. The availability of numerous terminal functional groups and modifiable surface engineering permit modification of dendrimer surface with several therapeutic agents, diagnostic moieties and targeting substances.The aim. To enlighten the readers regarding design, development, limitations, challenges and future directions regarding anticancer bio-dendrimers.Materials and methods. The data base was represented by such systems as Medline, Cochrane Central Register of Controlled Trials, Scopus, Web of Science Core Collection, PubMed. gov, Google-Academy. A search was carried out for the following keywords and combinations: Polypropylene imine (PPI); Poly-L-lysine (PLL); polyamidoamine (PAMAM); cancer; drug delivery; dendrimers.Results. High encapsulation of drug and effective passive targeting are also among their therapeutic uses. Herein, we have described latest developments in chemotherapeutic delivery of drugs by dendrimers. For the most part, the potential and efficacy of dendrimers are anticipated to have considerable progressive effect on drug targeting and delivery.Conclusion. The newest discoveries have shown that the dendritic nanocarriers have many unique features that endorse more research and development.
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Galenko, Petr, Mikhail Krivilyov, and Konstantin Emelyanov. "Bifurcations in a structure of a free-growing dendrite during solidification of a binary system." Izvestiya VUZ. Applied Nonlinear Dynamics 7, no. 2-3 (1999): 122–36. http://dx.doi.org/10.18500/0869-6632-1999-7-2-122-136.
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Using a model of local nonequilibrium solidification of supercooled binary system the dynamics of a motion of the liquid—solid interface having dendritic structure is investigated. The morphological spectrum of side—branch surface of a free—growing dendrite is defined. The modification of dendritic structure is considered in an association with two controlling parameters: an initial undercooling and position from the tip of dendrite which is define local undercooling at the phase interface. Due to the values of these parameters the interface can become unstable, periodic, and bifurcate with doubling, trebling of the period and so on.
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Schwindt, Peter C., and Wayne E. Crill. "Modification of Current Transmitted From Apical Dendrite to Soma by Blockade of Voltage- and Ca2+-Dependent Conductances in Rat Neocortical Pyramidal Neurons." Journal of Neurophysiology 78, no. 1 (1997): 187–98. http://dx.doi.org/10.1152/jn.1997.78.1.187.
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Schwindt, Peter C. and Wayne E. Crill. Modification of current transmitted from apical dendrite to soma by blockade of voltage- and Ca2+-dependent conductances in rat neocortical pyramidal neurons. J. Neurophysiol. 78: 187–198, 1997. The axial current transmitted to the soma during the long-lasting iontophoresis of glutamate at a distal site on the apical dendrite was measured by somatic voltage clamp of rat neocortical pyramidal neurons. Evidence for voltage- and Ca2+-gated channels in the apical dendrite was sought by examining the modification of this transmitted current resulting from the alteration of membrane potential and the application of channel-blocking agents. After N-methyl-d-aspartate receptor blockade, iontophoresis of glutamate on the soma evoked a current whose amplitude decreased linearly with depolarization to an extrapolated reversal potential near 0 mV. Under the same conditions, glutamate iontophoresis on the apical dendrite 241–537 μm from the soma resulted in a transmitted axial current that increased with depolarization over the same range of membrane potential (about −90 to −40 mV). Current transmitted from dendrite to soma was thus amplified during depolarization from resting potential (about −70 mV) and attenuated during hyperpolarization. After Ca2+ influx was blocked to eliminate Ca2+-dependent K+ currents, application of 10 mM tetraethylammonium chloride (TEA) altered the amplitude and voltage dependence of the transmitted current in a manner consistent with the reduction of dendritic voltage-gated K+ current. We conclude that dendritic, TEA-sensitive, voltage-gated K+ channels can be activated by tonic dendritic depolarization. The most prominent effects of blocking Ca2+ influx resembled those elicited by TEA application, suggesting that these effects were caused predominantly by blockade of a dendritic Ca2+-dependent K+ current. When cells were impaled with microelectrodes containing ethylene glycol-bis(β-amino-ethyl ether)- N,N′,N′-tetraacetic acid to prevent a rise in intracellular Ca2+ concentration, blockade of Ca2+ influx altered the tonic transmitted current in different manner consistent with the blockade of a inward dendritic current carried by high-threshold-activated Ca2+ channels. We conclude that the primary effect of Ca2+ influx during tonic dendritic depolarization is the activation of a dendritic Ca2+-dependent K+ current. The hyperpolarizing attenuation of transmitted current was unaffected by blocking all known voltage-gated inward currents except the hyperpolarization-activated cation current ( I h). Extracellular Cs+ (3 mM) reversibly abolished both the hyperpolarizing attenuation of transmitted current and I h measured at the soma. We conclude that activation of I h by hyperpolarization of the proximal apical dendrite would cause less axial current to arrive at the soma from a distal site than in a passive dendrite. Several functional implications of dendritic K+ and I h channels are discussed.
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Easton, Mark, John F. Grandfield, David H. StJohn, and Barbara Rinderer. "The Effect of Grain Refinement and Cooling Rate on the Hot Tearing of Wrought Aluminium Alloys." Materials Science Forum 519-521 (July 2006): 1675–80. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.1675.
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Using modifications to the Rappaz-Drezet-Gremaud hot tearing model, and using empirical equations developed for grain size and dendrite arm spacing (DAS) on the addition of grain refiner for a range of cooling rates, the effect of grain refinement and cooling rate on hot tearing susceptibility has been analysed. It was found that grain refinement decreased the grain size and made the grain morphology more globular. Therefore refining the grain size of an equiaxed dendritic grain decreased the hot tearing susceptibility. However, when the alloy was grain refined such that globular grain morphologies where obtained, further grain refinement increased the hot tearing susceptibility. Increasing the cooling decreased the grain size and made the grain morphology more dendritic and therefore increased the likelihood of hot tearing. The effect was particularly strong for equiaxed dendritic grain morphologies; hence grain refinement is increasingly important at high cooling rates to obtain more globular grain morphologies to reduce the hot tearing susceptibility.
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Шарипзянова, Г. Х., Ж. В. Еремеева, Р. А. В. Турлуев, Е. А. Гусева, and Ю. И. Карлина. "EFFECT OF MODIFYING ADDITIVES OF DYSPROSIUM TITANATE ON THE STRUCTURE OF SILUMIN AK12." Metallurg, no. 4 (April 29, 2024): 87–92. http://dx.doi.org/10.52351/00260827_2024_4_87.
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В настоящее время силумины, являющиеся алюминиевыми сплавами, наиболее широко используются в машиностроении, строительных конструкциях и других отраслях промышленности. Применение силуминов часто ограничено из-за наличия в них крупнокристаллических структур, таких как дендриты α-Al, игольчатые кристаллы эвтектического Si и интерметаллидных фаз. Проведен значительный объем работ по изучению влияния различных добавок и их взаимосвязи с микроструктурой и механическими свойствами в Fe-содержащих интерметаллидных фазах (Al–Si–Fe и Al–Si–Fe–Mn). Однако исследование влияния различных добавок на морфологию Fe-содержащих фаз в промышленных Al–Si сплавах остается актуальным. Исследовано влияние малых добавок титаната диспрозия (0,01; 0,05; 0,1; 0,5 масс. %) на морфологию и локализацию Fe-содержащих интерметаллидных фаз. Введение 0,01 масс. % титаната диспрозия приводит к переходу β-фазы, имеющей игольчатую форму, в α-фазу в форме более компактных блоков и полиэдрических кристаллов, с уменьшением размеров α-фазы более чем в 2 раза. При введении 0,05; 0,1 и 0,5 масс. % титаната диспрозия модификация α- и β-фаз сохраняется, а размер фаз уменьшается в среднем в 1,5 раза. После введения титаната диспрозия во всех модифицированных сплавах частицы θ-Al2Cu растворяются, а Cu концентрируется/локализуется в Fe-содержащих интерметаллидных фазах. Повышение предела прочности в сплавах АК12 после введения 0,05–0,5 масс. % титаната диспрозия обусловлено уменьшением размеров α- и β-фаз. Изменение модификации Fe-содержащих интерметаллидных фаз с β-фазы на α-фазу при введении 0,1 масс. % титаната диспрозия приводит к снижению предела прочности и относительного удлинения. Оптимальна добавка вольфрама в количестве 0,1 масс. %, так как приводит к оптимальному соотношению между структурой и механическими свойствами. Предел прочности и относительное удлинение увеличиваются в среднем на 23%. Currently silumins, which are aluminum alloys, are most widely used in mechanical engineering, building structures and other industries. The use of silumins is often limited due to the presence of large-crystalline structures in them, such as α-Al dendrites, needle crystals of eutectic Si and intermetallic phases. A significant amount of work has been carried out to study the effect of various additives and their relationship with the microstructure and mechanical properties in Fe-containing intermetallic phases (Al–Si–Fe and Al–Si–Fe–Mn). However, studies of the effect of various additives on the morphology of Fe-containing phases in industrial Al–Si alloys remain relevant. The effect of small additives of dysprosium titanate (0.01, 0.05, 0.1, 0.5 wt. %) on morphology and localization of Fe-containing intermetallic phases. Introduction 0.01 wt. % of dysprosium titanate leads to the transition of the needle-shaped β-phase into the α-phase in the form of more compact blocks and polyhedral crystals, with a decrease in the size of the α-phase by more than 2 times. With the introduction of 0.05, 0.1 and 0.5 wt. % dysprosium titanate modification of α- and β-phases is preserved, and the size of the phases decreases by an average of 1.5 times. After the introduction of dysprosium titanate in all modified alloys, θ-Al2Cu particles are dissolved, and Cu is concentrated/localized in Fe-containing intermetallic phases. Increasing the tensile strength in AK12 alloys after the introduction of 0.05–05 wt. % of dysprosium titanate is caused by a decrease in the size of α- and β-phases. Modification of Fe-containing intermetallic phases from the β-phase to the α-phase with the introduction of 0.1 wt. % of dysprosium titanate leads to a decrease in tensile strength and elongation. The optimum is the addition of tungsten in the amount of 0.1 wt. %, as it leads to an optimal ratio between the structure and mechanical properties. Tensile strength and elongation increase by an average of 23%.
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Kim, Junghwan, Kihwan Kwon, Kwanghyun Kim, Seungmin Han, Patrick Joohyun Kim, and Junghyun Choi. "Size Effect of a Piezoelectric Material as a Separator Coating Layer for Suppressing Dendritic Li Growth in Li Metal Batteries." Nanomaterials 13, no. 1 (2022): 90. http://dx.doi.org/10.3390/nano13010090.
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Li metal has been intensively investigated as a next-generation rechargeable battery anode. However, its practical application as the anode material is hindered by the deposition of dendritic Li. To suppress dendritic Li growth, introducing a modified separator is considered an effective strategy since it promotes a uniform Li ion flux and strengthens thermal and mechanical stability. Herein, we present a strategy for the surface modification of separator, which involves coating the separator with a piezoelectric material (PM). The PM-coated separator shows higher thermal resistance than the pristine separator, and its modified surface properties enable the homogeneous regulation of the Li-ion flux when the separator is punctured by Li dendrite. Furthermore, PM was synthesized in different solvents via solvothermal method to explore the size effect. This strategy would be helpful to overcome the intrinsic Li metal anode problems.
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Kim, Artem Eduardovich, Ludmila Jurievna Dobosh, and Valeri Mikhailovich Golod. "Filtration Permeability of Dendritic Structure in Condition of Diffusion-Capillary Coalescence of Secondary Side Branches." Key Engineering Materials 822 (September 2019): 23–29. http://dx.doi.org/10.4028/www.scientific.net/kem.822.23.
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The problem state of computer analysis of shrinkage defects in castings is analysed based on a review of theoretical and experimental studies the filtration permeability of solidifying alloys. It is shown that the use of the dimensionless permeability coefficient and its modification by introducing various corrections to the Karman-Kozeni equation, obtained for the stationary morphology of non-intersecting filtration channels, is inapplicable for the conditions of continuous change of their geometry during formation of dendrite structure. A computer model of the permeability for the mesoscale ensemble of secondary dendritic branches under the conditions of their diffusion-capillary coalescence is developed. Based on the thermodynamic apparatus and solidification modeling the influence of composition of Al-Cu-Mg alloys and heat removal velocity on the permeability coefficient under the evolution of the dendritic structure is analysed.
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Sunaina, Chaurasiya. "Dendrimer as drug delivery tool." Abstracts of International Conferences & Meetings (AICM) 1, no. 4 (2021): 14. https://doi.org/10.5281/zenodo.5149897.
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<strong>Introduction: </strong>Dendrimers, are the three-dimensional, hyperbranched globular novel nano-polymeric system. The physiochemical characteristic of dendrimers as nanoscopic size, high degree of branching, aqueous solubility, biocompatibility, and great versatility structural modification attract the attention of researchers to apply as a platform for the transport of bioactive molecules and enhances the solubility of hydrophobic active drugs. In addition, the availability of multiple functional groups at the periphery and cavities in the interior and the control over the dendrimers’ properties during their synthesis render them promising agents to use in several applications which makes them more promised amongst the available polymers (1, 2). <strong>Methods:</strong> Dendrimers are commonly developed by a divergent method or a convergent method. The divergent approach begins from a multifunction core molecule i.e., from core to the surface and in convergent methods initiates with surface to core possessing one reactive and two dormant groups. It gives the F-1 (first generation) dendrimer. The periphery of the developed molecule is activated for conjugation with more monomers (1). <strong>Results & Discussion:</strong> The analytical techniques are generally used to confirm the chemical composition, polydispersity, morphology, shape, homogeneity, reaction rate. molecular weights, scattering techniques, conjugation, structural deformities, and purity of dendrimers. These analyses include spectroscopic techniques, scattering methods, microscopic methods, electrical methods, chromatographic techniques, and physical or rheological properties analysis (4). <strong>Conclusions: </strong>The applications of dendrimers have been explored in a variety of fields such as drug delivery, gene delivery, imaging, diagnosis and photodynamic therapy. The terminal functionalities of dendrimers provide a platform for conjugation of the drug and targeting moieties as drug delivery tools. Furthermore, their coating with ligand(s) may reduce their toxic side effects and other biological obstacles in targeting potent ingredients to the targeted site(s) of interest with their controlled release effectively. The varied characteristics make dendrimers a great choice for diverse applications (2,3). <strong>Keywords: </strong><em>Dendrimers, biocompatibility, drug-delivery, toxicity, targeting moieties</em> <strong>References</strong> Kesharwani P, Jain K, Jain NK. Dendrimer as Nanocarrier for Drug Delivery. Prog. Polym. Sci. 2014;39(2):268-307. Santos A, Veiga F, Figueiras A. Dendrimers as Pharmaceutical Excipients: Synthesis, Properties, Toxicity and Biomedical Applications. Materials. 2020;13(1):65. Sandoval-Yañez C, Castro-Rodriguez C. Dendrimers: Amazing Platforms for Bioactive Molecule Delivery Systems. Materials. 2020;13(3):570. Caminade, A. M., Laurent, R., & Majoral, J. P. (2005). Characterization of dendrimers. <em>Advanced drug delivery reviews</em>, <em>57</em>(15), 2130-2146.
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Janaszewska, Lazniewska, Trzepiński, Marcinkowska, and Klajnert-Maculewicz. "Cytotoxicity of Dendrimers." Biomolecules 9, no. 8 (2019): 330. http://dx.doi.org/10.3390/biom9080330.
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Drug delivery systems are molecular platforms in which an active compound is packed into or loaded on a biocompatible nanoparticle. Such a solution improves the activity of the applied drug or decreases its side effects. Dendrimers are promising molecular platforms for drug delivery due to their unique properties. These macromolecules are known for their defined size, shape, and molecular weight, as well as their monodispersity, the presence of the void space, tailorable structure, internalization by cells, selectivity toward cells and intracellular components, protection of guest molecules, and controllable release of the cargo. Dendrimers were tested as carriers of various molecules and, simultaneously, their toxicity was examined using different cell lines. It was discovered that, in general, dendrimer cytotoxicity depended on the generation, the number of surface groups, and the nature of terminal moieties (anionic, neutral, or cationic). Higher cytotoxicity occurred for higher-generation dendrimers and for dendrimers with positive charges on the surface. In order to decrease the cytotoxicity of dendrimers, scientists started to introduce different chemical modifications on the periphery of the nanomolecule. Dendrimers grafted with polyethylene glycol (PEG), acetyl groups, carbohydrates, and other moieties did not affect cell viability, or did so only slightly, while still maintaining other advantageous properties. Dendrimers clearly have great potential for wide utilization as drug and gene carriers. Moreover, some dendrimers have biological properties per se, being anti-fungal, anti-bacterial, or toxic to cancer cells without affecting normal cells. Therefore, intrinsic cytotoxicity is a comprehensive problem and should be considered individually depending on the potential destination of the nanoparticle.
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Muslimov, Ilham Aliagaevich, Volker Nimmrich, Alejandro Ivan Hernandez, Andrew Tcherepanov, Todd Charlton Sacktor та Henri Tiedge. "Dendritic Transport and Localization of Protein Kinase Mζ mRNA". Journal of Biological Chemistry 279, № 50 (2004): 52613–22. http://dx.doi.org/10.1074/jbc.m409240200.
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Protein kinase Mζ (PKMζ) is an atypical protein kinase C isoform that has been implicated in the protein synthesis-dependent maintenance of long term potentiation and memory storage in the brain. Synapse-associated kinases are uniquely positioned to promote enduring consolidation of structural and functional modifications at the synapse, provided that kinase mRNA is available on site for local input-specific translation. We now report that the mRNA encoding PKMζ is rapidly transported and specifically localized to synaptodendritic neuronal domains. Transport of PKMζ mRNA is specified by two cis-acting dendritic targeting elements (Mζ DTEs). Mζ DTE1, located at the interface of the 5′-untranslated region and the open reading frame, directs somato-dendritic export of the mRNA. Mζ DTE2, in contrast, is located in the 3′-untranslated region and is required for delivery of the mRNA to distal dendritic segments. Colocalization with translational repressor BC1 RNA in hippocampal dendrites suggests that PKMζ mRNA may be subject to translational control in local domains. Dendritic localization of PKMζ mRNA provides a molecular basis for the functional integration of synaptic signal transduction and translational control pathways.
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Kim, Youngkwon, Beum Jin Park, Ji-Sang Yu, and Kyusoon Shin. "Polysiloxane-Coated PI Nonwoven Separators with Higher Thermal and Electrochemical Stability for Lithium Ion Battery Application." ECS Meeting Abstracts MA2023-02, no. 2 (2023): 336. http://dx.doi.org/10.1149/ma2023-022336mtgabs.
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Polyolefin separators are widely used for most of commercial application owing to their excellent mechanical properties, electrical insulation, and internal porous structures. The raw polyolefin materials have economic viability and possess facile mechanical extension suitable for processing as a film [1]. However, the inherent thermal property of polyolefin inevitably results in the severe thermal deformation of the separators upon the elevation of LiB temperature that has been pointed out as a major cause of fire in LiBs with the possibility of short circuits caused by lithium dendrites [2]. There have been trials to secure cycle characteristics by preventing LiB separators from shrinkage. But, even the coated polyolefin separator couldn’t have thermal stability at high temperatures above 180 oC, since the polyolefin was the base film material. Many studies have been performed to achieve high temperature stability with engineering plastics, including polyimide (PI) [1]. As PI has superior thermal stability, it has been widely applied as nonwoven separators. PI nonwoven fabric separators exhibit stability usually above 200 oC. As PI nonwoven separators have also high ionic conductivity and good electrolyte wettability, it is therefore expected to show excellent rate capability and cyclability [3]. Despite those advantages, however, PI nonwoven separators still have several issues to resolve before application of them to LiBs. One of the problems is the existence of large pores [4]. Pores over a certain size is thought to render particles in cathode active materials pass through or Li dendrites penetrate upon overcharging. Then, it can result in leakage current and internal short circuit eventually. Various studies such as particle-coating or ceramic-coating have been studied in order to figure out this problem [26]. Other than pore-size distribution or existence of large pores, it must be the electrochemical stability of PI nonwoven separator and the electrochemical cell performance with the separator at high voltage that needs to be studied and examined for the potential application to LiBs [3]. In accordance with the strong demand on high power LiB development, study on the electrochemical resistance of materials and components is highly required [5]. As PI has polar chemical structure in contrast to non-polar chemical structure of polyolefin, it would be worthy to investigate the electrochemical nature and stability under high current or high voltage. In this study, a PI nonwoven separator is modified by coating of polysiloxane to improve its electrochemical stability and properties as well as its porous structure. As the coated PI nonwoven separator should be stable up to 200 oC due to the robust PI frame and the modification via polysilicon-coating is rather simple, the feasibility of this chemical approach is demonstrated and studied including its electrochemical behaviors. Ionic conductivity, electrolyte wettability, and gas permeability of the modified separator is also examined as a set of tests for LiB application. It was electrochemically stable during LSV even at 5 V vs Li+/Li. The polysiloxane-coating maintains or improves the excellent thermal and electrical stability of the PI nonwoven separators. The full cell test demonstrated that the polysiloxane-coating enabled a cyclability of 98.6% after 100 cycles, while the PI nonwoven could not be charged due to an internal short circuit. [1] H. Lee, M. Yanilmaz, O. Toprakci, K. Fu, X. Zhang, A review of recent developments in membrane separators for rechargeable lithium-ion batteries, Energy Environ. Sci, 7, 2014, 3857. [2] X. Zhang, E. Sahraei, K. Wang, Li-ion Battery Separators, Mechanical Integrity and Failure Mechanisms Leading to Soft and Hard Internal Shorts, Sci. Rep., 6, 2016, 32578. [3] Z. Lu, F. Sui, Y. Miao, G. Liu, C. Li, W. Dong, J. Cui, T. Liu, J. Wu, C. Yang, Polyimide separators for rechargeable batteries, J. Energy Chem., 58, 2021, 170. [4] G. Dong, B. Liu, G. Sun, G. Tian, S. Qi, D. Wu, TiO2 nanoshell@polyimide nanofiber membrane prepared via a surface-alkaline-etching and in-situ complexation-hydrolysis strategy for advanced and safe LIB separator, J. Membr. Sci., 577, 2019, 249. [5] Y. Xiang, J. Li, J. Lei, D. Liu, Z. Xie, D. Qu, K. Li, T. Deng, H. Tang, Advanced Separators for Lithium-Ion and Lithium-Sulfur Batteries: A Review of Recent Progress, ChemSusChem, 9, 2016, 1. Figure 1
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Gao, Xiujie, Fei Wang, Yibo Xing, et al. "Modification of Cu-Based Current Collectors and Their Application in High-Performance Zn Metal Anode: A Review." Coatings 14, no. 10 (2024): 1300. http://dx.doi.org/10.3390/coatings14101300.
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Zinc-based batteries (ZBBs) have proven to be tremendously plausible for large-scale electrochemical energy storage applications due to their merits of desirable safety, low-cost, and low environmental impact. Nevertheless, the zinc metal anodes in ZBBs still suffer from many issues, including dendrite growth, hydrogen evolution reactions (HERs), corrosion, passivation, and other types of undesirable side reactions, which severely hinder practical application. The modification of Cu-based current collectors (CCs) has proven to be an efficient method to regulate zinc deposition and prevent dendritic growth, thereby improving the Coulombic efficiency (CE) and lifespan of batteries (e.g., up to 99.977% of CE over 6900 cycles after modification), which is an emerging research topic in recent years. In this review, we provide a systematic overview of the modification of copper-based CCs and their application in zinc metal anodes. The relationships between their modification strategies, nano-micro-structures, and electrochemical performance are systematically reviewed. Ultimately, their promising prospects for future development are also proposed. We hope that this review could contribute to the design of copper-based CCs for zinc-based batteries and facilitate their practical application.
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SZYMAŃSKI, PAWEŁ, MAGDALENA MARKOWICZ, and ELŻBIETA MIKICIUK-OLASIK. "NANOTECHNOLOGY IN PHARMACEUTICAL AND BIOMEDICAL APPLICATIONS: DENDRIMERS." Nano 06, no. 06 (2011): 509–39. http://dx.doi.org/10.1142/s1793292011002871.
Full textAbstract:
Nanotechnology, a separate field of knowledge since 1980s, involves utilization of nanomaterials not only in electronics and catalysis, but also in biomedical research including drug delivery, bioimaging, biomedical-diagnostics and tissue engineering. Multidisciplinary of this science has led to the development of different areas of technology and might contribute to innovations that will, as a final consequence, help humanity. Dendrimers are large and complex molecules that are characterized by well-defined nanoscale architecture, monodispersity and structural versatility. These highly interesting polymers consist of three elements: core, branches and peripheral groups. There is a wide variety of potential applications of dendritic polymers. One of the most promising is utilization of polyamidoamine (PAMAM) dendrimers as drug delivery devices. Among pharmaceuticals that have been connected with different types of dendrimers are nonsteroidal anti-inflammatory drugs (NSAIDs), anticancer drugs and other. Dendrimers application as drug carriers improves pharmacokinetic properties of drug particles, decreases drugs' side effects and, by possibility of surface modification with different ligands, enables to target specific tissues and tumor cells. Dendrimers might be also utilized as devices for delivery of genetic material and contrast agents for magnetic resonance imaging (MRI).
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Teruel-Juanes, R., B. Pascual-Jose, R. Graf, J. Reina, M. Giamberini, and A. Ribes-Greus. "Effect of Dendritic Side Groups on the Mobility of Modified Poly(epichlorohydrin) Copolymers." Polymers 13, no. 12 (2021): 1961. http://dx.doi.org/10.3390/polym13121961.
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The macromolecular dynamics of dendronized copolymer membranes (PECHs), obtained by chemical modification of poly(epichlorohydrin) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy] benzoate, was investigated. In response to a thermal treatment during membrane preparation, these copolymers show an ability to change their shape, achieve orientation, and slightly crystallize, which was also observed by CP-MAS NMR, XRD, and DSC. The phenomenon was deeply analyzed by dielectric thermal analysis. The dielectric spectra show the influence of several factors such as the number of dendritic side groups, the orientation, their self-assembling dendrons, and the molecular mobility. The dielectric spectra present a sub-Tg dielectric relaxation, labelled as γ, associated with the mobility of the benzyloxy substituent of the dendritic group. This mobility is not related to the percentage of these lateral chains but is somewhat hindered by the orientation of the dendritic groups. Unlike other less complex polymers, the crystallization was dismantled before the appearance of the glass transition (αTg). Only after that, clearing transition (αClear) can be observed. The PECHs were flexible and offered a high free volume, despite presenting a high degree of modifications. However, the molecular mobility is not independent in each phase and the self-assembling dendrons can be eventually fine-tuned according to the percentage of grafted groups.
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Chang, Shu Jui, Hsi Chen, and Nae-Lih (Nick) Wu. "Industry-Level Safety Enhancement of High-Energy Li-Ion Batteries Via Material-Level Surface Modification." ECS Meeting Abstracts MA2024-02, no. 7 (2024): 807. https://doi.org/10.1149/ma2024-027807mtgabs.
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Developing high-energy-density lithium-ion batteries (LIBs) to meet the needs of electric vehicles (EVs) and sustainable energy storage applications brings more safety issues simultaneously. On the anode side, graphite has the advantages of a high abundance and low lithiation electrochemical potential, which reduces the cost of LIBs and brings higher energy. However, graphite is vulnerable to the plating of metallic Li dendrite, which could easily arise from over-lithiation due to heterogeneity in the anode electrode or fast charging. Li dendritic deposits could penetrate through the separator to trigger cell short-circuit and eventually thermal runaway. On the cathode side, the Ni-rich layered oxide cathodes' high surface reactivity and low oxygen lattice stability lower the thermal stability. Moreover, it is easy to release oxygen during the charging and discharging, providing the negative electrode with abundant combustion accelerant and accelerating thermal runaway. An effective and efficient strategy to mitigate the abovementioned problems is to apply an artificial solid-electrolyte-interphase (A-SEI) coating on both the anode and cathode to alleviate the surface-side reactions. This study focuses on enhancing the safety of LIB full cells by modifying the properties and stability of the SEI on the anode and cathode electrodes. A polymeric artificial SEI coating for the anode improves electrode performance and effectively suppresses native SEI and Lithium dendrite formation. Meanwhile, a composite coating for the cathode simultaneously enhances cycle stability and thermal stability due to the altered thermal decomposition pathway of an NCM811 cathode. In this study, we will explain the electrochemical performance of using artificial SEI and the prevention mechanism of thermal runaways and verify the high safety of the modified full cells through nail penetration testing.
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Fracchia, Elisa, Federico Simone Gobber, and Mario Rosso. "Effect of Alloying Elements on the Sr Modification of Al-Si Cast Alloys." Metals 11, no. 2 (2021): 342. http://dx.doi.org/10.3390/met11020342.
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Strontium-based modifier alloys are commonly adopted to modify the eutectic silicon in aluminum-silicon casting alloys by changing the silicon shape from an acicular to a spherical form. Usually, the modifier alloy necessary to properly change the silicon shape depends on the silicon content, but the alloying elements’ content may have an influence. The AlSr10 master alloy’s modifying effect was studied on four Al-Si alloys through the characterization of microstructural and mechanical properties (micro-hardness and impact tests). The experimental results obtained on gravity cast samples highlighted the interdependence in the modification of silicon between the Si content and the alloying elements. After modification, a higher microstructural homogeneity characterized by a reduction of up to 22.8% in the size of intermetallics was observed, with a generalized reduction in secondary dendritic arm spacing. The presence of iron-based polygonal-shaped intermetallics negatively affects Sr modification; coarser silicon particles tend to grow close to α-Fe. The presence of casting defects such as bifilm reduces Sr modification’s beneficial effects, and little increase in absorbed impact energy is observed in this work.
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Çolak, M., and D. Dışpınar. "Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy." Archives of Foundry Engineering 17, no. 4 (2017): 35–42. http://dx.doi.org/10.1515/afe-2017-0127.
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AbstractGrain refining and modification are common foundry practice for improving properties of cast Al-Si alloys. In general, these types of treatments provide better fluidity, decreased porosity, higher yield strength and ductility. However, in practice, there are still some discrepancies on the reproducibility of the results from grain refining and effect of the refiner’s additions. Several factors include the fading effect of grain refinement and modifiers, inhomogeneous dendritic structure and non-uniform eutectic modification. In this study, standard ALCAN test was used by considering Taguchi’s experimental design techniques to evaluate grain refinement and modification efficiency. The effects of five casting parameters on the grain size have been investigated for A357 casting alloy. The results showed that the addition of the grain refiner was the most effective factor on the grain size. It was found that holding time, casting temperature, alloy type and modification with Sr were less effective over grain refinement.
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Lu, Yi, Shengping Wen, Wu Wei, et al. "The Synergistic Refinement and Modification of Al-7Si Alloys Caused by Trace Er and B." Metals 15, no. 4 (2025): 413. https://doi.org/10.3390/met15040413.
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In this investigation, it was found that the co-addition of Er and B causes both the modification and refinement of the Al-7Si alloy. The B element mainly forms a small amount of the AlB2 phase within the alloy, which can be used as a nucleation site for grains during casting, so the addition of B can significantly reduce the grain size of the Al-7Si alloy. However, the number density of AlB2 phase is too low, so its effect on improving the eutectic Si size and reducing the secondary dendrite arm spacing (SDAS) is not significant. The addition of 0.1 wt% Er can form a large amount of Al3Er phase within the alloy, which mainly serves as a nucleation site for eutectic Si during casting, so the addition of Er can significantly reduce the SDAS, eutectic Si size and morphology of Al-7Si alloys. However, due to the existence of a certain degree of mismatch between the Al matrix and the Al3Er phase, the relative grain refinement effect of Al3Er is not significant. In addition to this, we also observe the enrichment of Er at eutectic Si, which suggests that Er can interact with Si and thus inhibit the growth of eutectic Si. Therefore, Er can modulate eutectic Si through the Al3Er phase and the enrichment of Er. The co-addition of Er and B to Al-7Si alloys has better refining and modification effects than the addition of Er or B alone, mainly due to the modification effect of the Er element and the refining effect of the AlB2 phase. Unlike the Er-containing alloys, where the Al3Er phase plays a modifying role, the modification of the co-addition Er and B alloys is mainly caused by the enrichment of Er within the alloy.
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Nguyen, Bach, Nguyen Tran, et al. "Partial Surface Modification of Low Generation Polyamidoamine Dendrimers: Gaining Insight into their Potential for Improved Carboplatin Delivery." Biomolecules 9, no. 6 (2019): 214. http://dx.doi.org/10.3390/biom9060214.
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Carboplatin (CAR) is a second generation platinum-based compound emerging as one of the most widely used anticancer drugs to treat a variety of tumors. In an attempt to address its dose-limiting toxicity and fast renal clearance, several delivery systems (DDSs) have been developed for CAR. However, unsuitable size range and low loading capacity may limit their potential applications. In this study, PAMAM G3.0 dendrimer was prepared and partially surface modified with methoxypolyethylene glycol (mPEG) for the delivery of CAR. The CAR/PAMAM G3.0@mPEG was successfully obtained with a desirable size range and high entrapment efficiency, improving the limitations of previous CAR-loaded DDSs. Cytocompatibility of PAMAM G3.0@mPEG was also examined, indicating that the system could be safely used. Notably, an in vitro release test and cell viability assays against HeLa, A549, and MCF7 cell lines indicated that CAR/PAMAM G3.0@mPEG could provide a sustained release of CAR while fully retaining its bioactivity to suppress the proliferation of cancer cells. These obtained results provide insights into the potential of PAMAM G3.0@mPEG dendrimer as an efficient delivery system for the delivery of a drug that has strong side effects and fast renal clearance like CAR, which could be a promising approach for cancer treatment.
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Sim, Hui-Tae, Myungkeun Oh, Ye-Eun Park, et al. "Li Metal Surface Modification to Stabilize Lithium-Argyrodite Interface for Sulfide-Based All-Solid-State Lithium Metal Batteries." ECS Meeting Abstracts MA2024-02, no. 8 (2024): 1214. https://doi.org/10.1149/ma2024-0281214mtgabs.
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Since the commercialization of lithium-ion batteries, they have faced limitation in safety and energy density. All-solid-state lithium metal batteries (ASSLMBs) can be a solution to address these issues. Among many types of solid electrolytes, sulfide-based solid electrolytes have been attracted great attention because of their high ion conductivity and ductile property. However, many researchers have reported that the interface between lithium metal and solid electrolyte is highly unstable. The lithium dendrite growth can be also occurred in the ASSLMBs by voids, cracks, grain boundaries in solid electrolyte and side reactions between lithium metal and solid electrolyte. Therefore, it is imperative to develop a protective layer that can suppress lithium dendrites and side reactions. In our work, we removed native resistive surface layer formed on pristine lithium metal and reconstructed solid electrolyte interphases (SEI) with uniform, ion-conductive and excellent physical properties by dipping solution containing lithium nitrate in nitromethane and dimethoxyethane. The modified lithium metal is denoted as Li@NDL (lithium @ nitromethane-dimethoxyethane-lithium nitrate). We confirmed that nitromethane reacted with LiOH and Li2O on native surface of lithium to form Li3N and organic layer, which enhanced ionic conductivity and mechanical strength. The symmetric lithium cell with Li@NDL increased critical current density to 2.8 mA cm-2 and exhibited outstanding cycling stability without short circuit over 1000 hours. ASSLMB comprising Li@NDL anode and 4 mAh cm-2 NCM composite cathode maintained 80% retention after 200th cycles at 0.5 C, demonstrating our work can provide a novel surface modification of lithium metal for ASSLMBs.
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Rzychoń, Tomasz, and Radosław Janik. "The Influence of Calcium on the Primary Mg2Si Phase in the Hypereutectic Mg-Si Alloys." Solid State Phenomena 229 (April 2015): 71–76. http://dx.doi.org/10.4028/www.scientific.net/ssp.229.71.
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The microstructure of Mg-5Si alloy consists of the primary coarse Mg2Si phase, α-Mg solid solution and eutectic α-Mg + Mg2Si, in which eutectic Mg2Si phase solidifies in the form of Chinese script particles. When 0.2 wt.% of Ca was added to the Mg-5Si alloy the size of primary Mg2Si phase remained unchanged. The modification effect of calcium on the primary Mg2Si phase was effective only in the Mg-5Si-0.5Ca alloy. The morphology of the primary Mg2Si phase is changed from the coarse dendrite shape to polyhedral shape and the size of primary crystals is significantly reduced. The addition of 0.6 wt.% Ca to Mg-7Si alloy did not cause the modification of primary Mg2Si phase.
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Prіgunova, А. G., Y. A. Zhydkov, V. D. Babiuk, L. K. Shenevidko, and T. G. Tsir. "Management the structure and properties of cast aluminum alloy AM4.5Kd (VAL10) by modification with fine crystalline ligatures." Metaloznavstvo ta obrobka metalìv 103, no. 3 (2022): 3–17. http://dx.doi.org/10.15407/mom2022.03.003.
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To management the structure, mechanical and operational properties of the high-strength cast aluminum alloy АМ4.5Кд (ВАЛ10), the work uses a modification method based on the principle of structural inheritance, using rapidly cooled (Vcool. ≥ 10^5 °С/s) fine-crystal ligatures AlTi5 and AlZr10, and as well as ligatures of the chemical composition of the base alloy with nanoscale size of intermetallics and Alα crystals. Studies have shown that the introduction of fine-crystalline additives into the melt leads to a transition from a dendritic to a non-dendritic structure, a significant decrease in the size of the crystals of the Alα solid solution, and an increase in its degree of supersaturation. The microstructure becomes more uniform - the difference between the maximum and minimum size of the grains decreases. The most effective reduction of the grain size and the transition from dendritic to non-dendritic structure of the aluminum solid solution at increased cooling rates occurs when alloying with fine-crystal AlTi5 ligature introduced into the melt in terms of pure titanium 0.05-0.15 wt. %. We must think that the main factor of modification by rapidly cooled ligatures is the introduction of a large number of additional crystallization centers into the melt. After T6 heat treatment, the highest strength of AM4.5Kd alloy (VAL10) is achieved when modified with AlZr10 ligature, in particular, with a mass fraction of zirconium of 0.25%. Probably, this is mainly due to the expansion of the region of the solid solution of copper and zirconium in aluminum during high-speed cooling and its subsequent disintegration during heat treatment with the release of strengthening nano-sized CuAl2 and Al3Zr phases. Tribological studies of AM4.5Kd alloy (VAL10) were carried out. The alloy modified with fine crystal ligature of the base alloy composition in the amount of 12 wt.% has the highest wear resistance. Keywords: fine crystal ligatures, AM4.5Kd (VAL10), modification, microstructure, strength, wear resistance.
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Zenze, Mkhuseli, Aliscia Daniels, and Moganavelli Singh. "Dendrimers as Modifiers of Inorganic Nanoparticles for Therapeutic Delivery in Cancer." Pharmaceutics 15, no. 2 (2023): 398. http://dx.doi.org/10.3390/pharmaceutics15020398.
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The formulation of nanoscale systems with well-defined sizes and shapes is of great interest in applications such as drug and gene delivery, diagnostics and imaging. Dendrimers are polymers that have attracted interest due to their size, shape, branching length, amine density, and surface functionalities. These unique characteristics of dendrimers set them apart from other polymers, their ability to modify nanoparticles (NPs) for biomedical applications. Dendrimers are spherical with multiple layers over their central core, each representing a generation. Their amphiphilic nature and hollow structure allow for the incorporation of multiple drugs or genes, in addition to enabling easy surface modification with cellular receptor-targeting moieties to ensure site-specific delivery of therapeutics. Dendrimers are employed in chemotherapeutic applications for the delivery of anticancer drugs. There are many inorganic NPs currently being investigated for cancer therapy, each with their own unique biological, chemical, and physical properties. To favor biomedical applications, inorganic NPs require suitable polymers to ensure stability, biodegradability and target specificity. The success of dendrimers is dependent on their unique structure, good bioavailability and stability. In this review, we describe the properties of dendrimers and their use as modifiers of inorganic NPs for enhanced therapeutic delivery. Herein, we review the significant developments in this area from 2015 to 2022. Databases including Web of Science, Scopus, Google Scholar, Science Direct, BioMed Central (BMC), and PubMed were searched for articles using dendrimers, inorganic nanoparticles and cancer as keywords.
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Chen, Diantao, Jiawei Zhang, Qian Liu, Fan Wang, Xin Liu, and Minghua Chen. "The Introduction of a BaTiO3 Polarized Coating as an Interface Modification Strategy for Zinc-Ion Batteries: A Theoretical Study." International Journal of Molecular Sciences 25, no. 20 (2024): 11172. http://dx.doi.org/10.3390/ijms252011172.
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Aqueous zinc-ion batteries (AZIBs) have become a promising and cost-effective alternative to lithium-ion batteries due to their low cost, high energy, and high safety. However, dendrite growth, hydrogen evolution reactions (HERs), and corrosion significantly restrict the performance and scalability of AZIBs. We propose the introduction of a BaTiO3 (BTO) piezoelectric polarized coating as an interface modification strategy for ZIBs. The low surface energy of the BTO (110) crystal plane ensures its thermodynamic preference during crystal growth in experimental processes and exhibits very low reactivity toward oxidation and corrosion. Calculations of interlayer coupling mechanisms reveal a stable junction between BTO (110) and Zn (002), ensuring system stability. Furthermore, the BTO (110) coating also effectively inhibits HERs. Diffusion kinetics studies of Zn ions demonstrate that BTO effectively suppresses the dendrite growth of Zn due to its piezoelectric effect, ensuring uniform zinc deposition. Our work proposes the introduction of a piezoelectric material coating into AZIBs for interface modification, which provides an important theoretical perspective for the mechanism of inhibiting dendrite growth and side reactions in AZIBs.
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Song, Wenru, Hwai-Loong Kong, Heather Carpenter, et al. "Dendritic Cells Genetically Modified with an Adenovirus Vector Encoding the cDNA for a Model Antigen Induce Protective and Therapeutic Antitumor Immunity." Journal of Experimental Medicine 186, no. 8 (1997): 1247–56. http://dx.doi.org/10.1084/jem.186.8.1247.
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Dendritic cells (DCs) are potent antigen-presenting cells that play a critical role in the initiation of antitumor immune responses. In this study, we show that genetic modifications of a murine epidermis-derived DC line and primary bone marrow–derived DCs to express a model antigen β-galactosidase (βgal) can be achieved through the use of a replication-deficient, recombinant adenovirus vector, and that the modified DCs are capable of eliciting antigen-specific, MHC-restricted CTL responses. Importantly, using a murine metastatic lung tumor model with syngeneic colon carcinoma cells expressing βgal, we show that immunization of mice with the genetically modified DC line or bone marrow DCs confers potent protection against a lethal tumor challenge, as well as suppression of preestablished tumors, resulting in a significant survival advantage. We conclude that genetic modification of DCs to express antigens that are also expressed in tumors can lead to antigen-specific, antitumor killer cells, with a concomitant resistance to tumor challenge and a decrease in the size of existing tumors.
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Li, Dongdong, Yuan Gao, Chuan Xie, and Zijian Zheng. "Au-coated carbon fabric as Janus current collector for dendrite-free flexible lithium metal anode and battery." Applied Physics Reviews 9, no. 1 (2022): 011424. http://dx.doi.org/10.1063/5.0083830.
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Composite lithium metal anodes with three-dimensional (3D) conductive fabric present great potential to be used in high-energy-density flexible batteries for next-generation wearable electronics. However, lithium dendrites at the top of the fabric anode increase the risk of separator piercing and, therefore, cause a high possibility of short circuits, especially when undergoing large mechanical deformation. To ensure the safe application of the flexible lithium metal batteries, we herein propose a 3D Janus current collector by a simple modification of the bottom side of carbon fabric (CF) with a lithiophilic Au layer to construct highly flexible, stable, and safe Li metal anodes. The Janus Au layer can guide an orientated deposition of Li to the bottom of the CF. The lithium dendrite problem can be largely alleviated due to the lithium-free interface between the anode and separator, and meanwhile, the porous upper skeleton of the CF also provides large space to buffer the volume expansion of lithium metal. The resulting composite lithium metal anode exhibits a significant improvement in the life cycle (∼two fold) compared to the traditional top deposition of lithium metal. More importantly, assembled full batteries using the Janus anode structure exhibit high stability and safety during severe mechanical deformation, indicating the opportunity of the orientated deposition strategy to be used in future flexible and wearable electronics.
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Wang, Yixian, and David Mitlin. "Mechanical Milling - Induced Microstructure Changes in Argyrodite Lpscl Solid-State Electrolyte Critically Affect Electrochemical Stability." ECS Meeting Abstracts MA2024-02, no. 8 (2024): 1241. https://doi.org/10.1149/ma2024-0281241mtgabs.
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In the early stages of sulfide solid-state electrolyte (SSE) research, sulfides like Li6PS5Cl (LPSCl) were primarily synthesized in laboratories using fine precursors such as Li2S, LiCl, and P2S5, employing meticulous synthetic procedures involving milling and sintering. This approach resulted in grams of as-synthesized SSE materials with a uniform particle size distribution and well-controlled morphology. Consequently, large-scale synthesis methods for LPSCl SSE have been developed, leading to the availability of commercial LPSCl SSE. Nonetheless, compared to lab-scale synthesis, commercial production of LPSCl SSE often yields a wide range of particle sizes and particle distributions. In-depth understanding is needed regarding how microstructural features such as the average particle size and distribution, and pore size and distribution, affect the compressed SSE's electrochemical performance. In this presentation, we investigate mechanical milling – induced microstructure changes of LPSCl SSE and their influence on electrochemical performance. Planetary mechanical milling in wet media (m-xylene) is employed to alter commercial LPSCl powder. Quantitative stereology demonstrates how extended milling progressively refines grain and pore size/distribution, increases compact density, and geometrically smoothens the SSE-Li interface. Microstructure, in turn, profoundly influences electrochemical behavior. It is shown that an optimized SSE microstructure enables state-of-the-art electrochemical performance without the need for any artificial SEI layers or other secondary modifications. Combined cryogenic focused ion beam (cryo-FIB) and X-ray photoelectron spectroscopy (XPS) demonstrate that milled microstructures promote uniform early-stage electrodeposition on foil collectors and stabilize solid electrolyte interphase (SEI) reactivity. For the first time, short-circuiting Li metal dendrite is directly identified, employing 1.5 mm diameter "mini" symmetrical cell and cryo-FIB. Site-specific analysis highlights that the lithium metal dendrite has the following features: a) a sheet-like morphology with branching sections; b) traverses the compact intergranularly, moving around large grains rather than through them; c) fills the interparticle voids and reacts with the contacting SSE to form reduction decomposition products, i.e. the dendrite is surrounded by an SEI. Figure 1
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Tao, Jin. "Study of Modification Mechanism of Ultrafine Silica Modified by PAMAM." Applied Mechanics and Materials 217-219 (November 2012): 252–55. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.252.
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Ultrafine silicon dioxide were modified by -NH2-teminated poly(amido-amine) (PAMAM) dendrimers to improve their dispersibility in the coatings. The modification mechanism was studied through density functional theory (DFT) in the gas phase. Virous initial configurations of ion bound to PAMAM were established to investigate the structures and the energetics of the complexes. Two stable conformers are found: types A ( is bound to the amine site) and C ( is bound to the amide site). Types A and C indicate the chemical bond formation of Si-N and Si-O, respectively.
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Gao, Zhi Guo. "Numerical Analysis of Stray Grain Formation during Laser Welding Nickel-Based Single-Crystal Superalloy Part II: Multicomponent Dendrite Growth." Materials Science Forum 1033 (June 2021): 31–39. http://dx.doi.org/10.4028/www.scientific.net/msf.1033.31.
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Multicomponent dendrite growth is theoretically predicted to optimize solidification cracking susceptibility during ternary Ni-Cr-Al nickel-based single-crystal superalloy weld pool solidification. The distribution of dendrite trunk spacing along the weld pool solidification interface is clearly symmetrical about the weld pool centerline in beneficial (001)/[100] welding configuration. The distribution of dendrite trunk spacing along the weld pool solidification interface is crystallography-dependent asymmetrical from bottom to top surface of the weld pool in detrimental (001)/[110] welding configuration. The smaller heat input is used, the finer dendrite trunk spacing is kinetically promoted by less solute enrichment and narrower constitutional undercooling ahead of solid/liquid interface with mitigation of metallurgical contributing factors for solidification cracking and vice versa. Vulnerable [100] dendrite growth region is predominantly suppressed and epitaxial [001] dendrite growth region is favored to spontaneously facilitate single-crystal columnar dendrite growth and reduce microstructure anomalies with further reduction of heat input. Optimum low heat input (both lower laser power and higher welding speed) with (001)/[100] welding configuration is the most favorable one to avoid nucleation and growth of stray grain formation, minimize both dendrite trunk spacing and solidification cracking susceptibility potential, improve resistance to solidification cracking, and ameliorate weldability and weld integrity through microstructure modification instead of inappropriate high heat input (both higher laser power and slower welding speed) with (001)/[110] welding configuration. The dendrite trunk spacing in the [100] dendrite growth region on the right side of the weld pool is considerably coarser and grows faster than that within the [010] dendrite growth region of the left side in the (001)/[110] welding configuration to deteriorate weldability, although the welding conditions are the same on the either side. Furthermore, the alternative mechanism of crystallography-dependent solidification cracking as consequence of asymmetrical microstructure development and diffusion-controlled dendrite growth of γ phase is therefore proposed. The theoretical predictions are comparable with experiment results. The reliable model is also useful for welding conditions optimization for crack-free laser processing.
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Gao, Yue, Xiao Sang, Yifan Chen, et al. "Polydopamine modification electrospun polyacrylonitrile fibrous membrane with decreased pore size and dendrite mitigation for lithium ion battery." Journal of Materials Science 55, no. 8 (2019): 3549–60. http://dx.doi.org/10.1007/s10853-019-04218-9.
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Rajković, Nemanja, Bojana Krstonošić, and Nebojša Milošević. "Box-Counting Method of 2D Neuronal Image: Method Modification and Quantitative Analysis Demonstrated on Images from the Monkey and Human Brain." Computational and Mathematical Methods in Medicine 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/8967902.
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This study calls attention to the difference between traditional box-counting method and its modification. The appropriate scaling factor, influence on image size and resolution, and image rotation, as well as different image presentation, are showed on the sample of asymmetrical neurons from the monkey dentate nucleus. The standard BC method and its modification were evaluated on the sample of 2D neuronal images from the human neostriatum. In addition, three box dimensions (which estimate the space-filling property, the shape, complexity, and the irregularity of dendritic tree) were used to evaluate differences in the morphology of type III aspiny neurons between two parts of the neostriatum.
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Cho, Hoon, Byoung Soo Lee, and Hyung Ho Jo. "Modification of A3003 Alloy for Development of High Toughness Al Alloy Tube." Materials Science Forum 546-549 (May 2007): 615–18. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.615.
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The strength of aluminum alloys was improved by a severe deformation process while the decrease of elongation leads to the defect. Modification of A3003 alloy was attempted in order to develop a high strength and high formability Al alloy tube for the application of air-conditioning systems in transportation, such as passenger planes and automobiles. An A3003 alloy was modified by Ti addition, grain refiner. As a result of modification, the modified A3003 alloy was able to suitably satisfy the mechanical strength requirements, including elongation. Grain size and secondary dendrite arm spacing of A3003 alloy decreased by as much as 50 % by Ti addition. The finer grains were uniformly distributed in the modified A3003 alloy billet. The yield strength of the modified A3003 alloy was improved by 30 % without decreasing elongation.
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Han, Ruihui, Dewen Zhang, Jie Sheng, Guangcheng Zhu, Ziheng Wang, and Deyang Dong. "Characterization of LDPE and SiO2/LDPE AC Dendritic Growth after Tensile Stressing." Journal of Physics: Conference Series 3008, no. 1 (2025): 012040. https://doi.org/10.1088/1742-6596/3008/1/012040.
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Abstract Large-length power cables inevitably generate residual mechanical stress in the insulation layer during the manufacturing and laying process, especially during the production of factory joints. This paper addresses the AC dendrite initiation, growth influence, mechanism of action, and improvement mechanism of low-density polyethylene (LDPE) and SiO2/LDPE after the action of tensile stress. The crystalline morphology was observed by scanning electron microscope (SEM), and the results showed that the unstretched LDPE has an obvious spherical crystal structure and the diameter of the spherical crystal is about 3~5 μm, the spherical crystal structure of SiO2/LDPE composite material is looser, and the size of the spherical crystal is about 1~2 μm. After stressing, the spherical crystal structure of the LDPE material has an obvious orientation change, and the diameter of the spherical crystal along the long axis of stress direction reaches 8 μm, compared with that of LDPE after stretching. The diameter of the spherical crystal along the long axis of the stress direction reaches 8 μm, and the SiO2/LDPE spherical crystal structure is more stable. The AC dendrite characterization test showed that the growth direction of the dendrite and the stress direction showed an orthogonal relationship, and the transverse extension ratio of the dendrite before and after modification by nano-SiO2 was about 11.5:7 when the parallel stress needle was inserted, and the transverse extension range of the dendrite was reduced.