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Results 141-150 of 187 (Search time: 0.005 seconds).
  • Authors: Nué, Charline Le; Gallo, Santiago Corujeira; Vahid, Alireza;  Advisor: -;  Co-Author: - (2023)

    High-chromium cast irons are an essential class of wear-resistant materials commonly used for wear-resistant applications in the mining and steel industries. There is ongoing debate on the secondary carbide types and their formation sequences during heat treatment. This work examines the microstructural evolution during destabilization treatment of a hypoeutectic high-chromium cast iron containing 2.2 wt pct C and 16.5 wt pct Cr. Starting from an inhomogeneous as-cast microstructure consisting of ~ 28 pct M7C3 eutectic carbide and a mixed matrix of martensite and retained austenite, destabilization treatments resulted in the establishment of near homogeneous structure with a near equilibrium level of carbon concentration in the matrix, which fully transformed to martensite upon cool...

  • Authors: Dong, Min; Liu, Ying; Liu, Biao;  Advisor: -;  Co-Author: - (2023)

    Glioma is the most common malignant tumor of the brain and enhancing the efficacy of chemotherapy in glioma is critical for improving patients’ prognosis. In this study, a glioma-targeting drug delivery system is constructed using biodegradable periodic mesoporous organosilica nanoparticles (PMO) that are modified with lactoferrin (Lf) ligands. The obtained PMO is doped with thioether groups and can be degraded in the high concentration of glutathione in tumor cells. The surface area and pore volume of PMO are 772 cm2/g and 0.98 cm3/g, respectively and the loading capacity of doxorubicin (Dox) is as high as 20%. The results of the confocal laser scanning microscope show that the uptake of PMO-Lf@Dox by C6 cells is higher than PMO@Dox.

  • Authors: Durán, A.; Reguera, E.; Mendivil, L. F.;  Advisor: -;  Co-Author: - (2023)

    In recent years, raising investigation activity in entropy-stabilized ceramic oxides has been driven by their innovative approach to designing a thermodynamically stable multi-element system, which provides a new focus on investigating complex functional materials. Especially, complex and singular physical properties of orthochromite have generated rising research in recent years. Of this family, the PrCrO3, DyCrO3, and HoCrO3 systems are particularly interesting since, below Néel temperature (TN), they present negative magnetization in the ZFC mode. Here, we have employed this approach and designed a medium-entropy (MECs) Pr1/3Dy1/3Ho1/3CrO3 (PDH) ceramic to study not only whether the magnetic characteristics prevail, but also the state of optical and dielectric properties of this ...

  • Authors: Xing, Xinyue; Zeng, Yuying; Zhong, Wanqing;  Advisor: -;  Co-Author: - (2023)

    Engineering nanotherapeutics have been extensively studied for cancer therapy. However, the therapeutic efficacy is still severely restricted by biophysiological barriers and intracellular accumulation. Although the biomimetic nanoparticles have improved the former issue, there is almost no breakthrough in researches of intracellular transport. Herein, we proposed a NIR-responsive nuclear-targeted hybrid membrane biomimetic Prussian blue drug-loading nanotherapeutics (PB@DN@M).

  • Authors: Egels, G.; Bussmann, M.; Benito, S.;  Advisor: -;  Co-Author: - (2023)

    In this study, the deformation-induced α-martensite formation in AISI 304L steel was investigated in the temperature range between 75 °C and − 196 °C in the light of the temperature-dependence of hydrogen embrittlement phenomena. For this purpose, tensile tests with in-situ and ex-situ magnetic measurement of the α-martensite volume content as a function of plastic strain were carried out. In addition, a theoretical assessment of the temperature-dependence of the austenite stability was undertaken, evaluating chemical and non-chemical driving force contributions to the martensitic γ → α transformation as proposed by Ghosh and Olson.

  • Authors: Iwasaki, Yuichi; Takeshita, Kazutaka M.; Ueda, Koji;  Advisor: -;  Co-Author: - (2023)

    Estimation of a species sensitivity distribution (SSD) by fitting a statistical distribution to ecotoxicity data is a promising approach to deriving “safe” concentrations for microplastics. However, most existing SSDs do not quantitatively consider the diverse characteristics of microplastics, such as particle size and shape. To address this issue, based on 38 mass-based chronic no observed effect concentrations (NOECs) obtained from a recently created database, we estimated SSDs that quantitatively consider the influences of three types of microplastic characteristics (particle length, shape, and polymer type) and habitat of the test species (freshwater vs. marine) by using Bayesian modeling.

  • Authors: Khalifa, Zaki S.; Mohamed, S. H.;  Advisor: -;  Co-Author: - (2023)

    SnxSb20Se80−x bulk glasses were prepared using the well-known melt quenching technique, where x was taken as 7.5 at.%, 9.5 at.%, 11.5 at.% and 13 at.%. X-ray diffraction (XRD) and differential scanning calorimetery (DSC) were used to monitor the crystallinity and transition temperatures, respectively. XRD examinations showed that the 7.5 at.% and 9.5 at.% compositions were purely amorphous, while the other two compositions exhibited a crystalline structure. DSC thermograms demonstrated that 7.5 at.% and 9.5 at.% alloys had a single crystallization peak, whereas for the 11.5 at.% and 13 at.% alloys, two exothermic peaks and three peaks appeared.

  • Authors: Ludwig, Andreas; Mogeritsch, Johann;  Advisor: -;  Co-Author: - (2023)

    Herein, in a microgravity campaign onboard the International Space Station, peritectic coupled growth (PCG) is studied by solidifying alloys of the peritectic transparent organic system TRIS–NPG under purely diffusive conditions. The experiment reveals that the formation of PCG begins with coagulated lateral bands comprising the peritectic phase at temperatures below the peritectic one. After reaching the growth front of the pro-peritectic phase, growth competition between both solid phases occurs such that the patches of the pro-peritectic phase, lamellae, and fibers/rods grow in the stated order, coupled with the peritectic phase. As the entire solidification process occurs during the initial transient stage, the diffusion coupling between the two solid phases is weak.

  • Authors: Bracker, Gwendolyn P.; Hyers, Robert W.;  Advisor: -;  Co-Author: - (2023)

    In oscillating drop experiments, surface oscillations in a molten sample are captured and analyzed to determine the surface tension and viscosity of a melt without the need to contact the liquid sample. In electromagnetic levitation, surface oscillations are initiated using an excitation pulse in the electromagnetic field. The variation in the electromagnetic force field drives rapid acceleration in the melt while also changing the flow pattern. During the quasi-static flow conditions prior to the excitation pulse, the flow displays a “positioner-dominated” flow pattern with 4 recirculation loops in the sample hemisphere. However, the accelerating flow of the excitation pulse transitions into a “heater-dominated flow” pattern in which there are only 2 recirculation loops in the samp...

  • Authors: Ma, Xidong; Zhang, Yukun; Li, Yan;  Advisor: -;  Co-Author: - (2023)

    s the material product of socialist construction activities, the socialist built heritage (SBH) represents socialist-era achievements and has unique cultural value. However, political controversy and inadequate conservation awareness have produced an unprecedented crisis. The aim of this study was to draw worldwide attention to the value of SBH to promote future conservation. Taking the socialist country of China as a representative example, the spatial distribution and spatial–temporal evolution of SBH during the Socialist Revolution and Construction Period (1949–1978) were explored using GIS analysis tools from typological and holistic perspectives. A geographic detector was also applied to reveal the driving factors that affected the distribution. The results indicate that (1) fr...