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961.
A desirability function method for optimizing mean and variability of multiple responses using a posterior preference articulation approach
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Dong‐Hee Lee In‐Jun Jeong Kwang‐Jae Kim 《Quality and Reliability Engineering International》2018,34(3):360-376
A desirability function approach has been widely used in multi‐response optimization due to its simplicity. Most of the existing desirability function‐based methods assume that the variability of the response variables is stable; thus, they focus mainly on the optimization of the mean of multiple responses. However, this stable variability assumption often does not apply in practical situations; thus, the quality of the product or process can be severely degraded due to the high variability of multiple responses. In this regard, we propose a new desirability function method to simultaneously optimize both the mean and variability of multiple responses. In particular, the proposed method uses a posterior preference articulation approach, which has an advantage in investigating tradeoffs between the mean and variability of multiple responses. It is expected that process engineers can use this method to better understand the tradeoffs, thereby obtaining a satisfactory compromise solution. 相似文献
962.
Development of Dual‐Pore Coexisting Branched Silica Nanoparticles for Efficient Gene–Chemo Cancer Therapy
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Jong‐Hwan Lee Seounghun Kang Minchul Ahn Hongje Jang Dal‐Hee Min 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(7)
Various strategies for combination therapy to overcome current limitations in cancer therapy have been actively investigated. Among them, simultaneous delivery of multiple drugs is a subject of high interest due to anticipated synergistic effect, but there have been difficulties in designing and developing effective nanomaterials for this purpose. In this work, dual‐pore coexisting hybrid porous silica nanoparticles are developed through Volmer–Weber growth pathway for efficient co‐delivery of gene and anticancer drug. Based on the different pore sizes (2–3 and 40–45 nm) and surface modifications of the core and branch domains, loading and controlled release of gene and drug are achieved by appropriate strategies for each environment. With excellent loading capacity and low cytotoxicity of the present platform, the combinational cancer therapy is successfully demonstrated against human cervical cancer cell line. Through a series of quantitative analyses, the excellent gene–chemo combinational therapeutic efficiency is successfully demonstrated. It is expected that the present nanoparticle will be applicable to various biomedical fields that require co‐delivery of small molecule and nucleic acid. 相似文献
963.
Asymmetric Fullerene Nanosurfactant: Interface Engineering for Automatic Molecular Alignments
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Dae‐Yoon Kim Sang‐A Lee Soeun Kim Changwoon Nah Seung Hee Lee Kwang‐Un Jeong 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(1)
Since the molecular self‐assembly of nanomaterials is sensitive to their surface properties, the molecular packing structure on the surface is essential to build the desired chemical and physical properties of nanomaterials. Here, a new nanosurfactant is proposed for the automatic construction of macroscopic surface alignment layer for liquid crystal (LC) molecules. An asymmetric nanosurfactant (C60NS) consisted of mesogenic cyanobiphenyl moieties with flexible alkyl chains and a [60]fullerene nanoatom is newly designed and precisely synthesized. The C60NS directly introduced in the anisotropic LC medium is self‐assembled into the monolayered protrusions on the surface because of its amphiphilic nature originated by asymmetrically programmed structural motif of LC‐favoring moieties and LC‐repelling groups. The monolayered protrusions constructed by the phase‐separation and self‐assembly of asymmetric C60NS nanosurfactant in the anisotropic LC media amplify and transfer the molecular orientational order from surface to bulk, and finally create the automatic vertical molecular alignment on the macroscopic length scale. The asymmetric C60NS nanosurfactant and its self‐assembly described herein can offer the direct guideline of interface engineering for the automatic molecular alignments. 相似文献
964.
Lee Jin Hee Lee Hack-Keun Chun Dong Hyun Choi Hyunkyung Rhim Geun Bae Youn Min Hye Jeong Heondo Kang Shin Wook Yang Jung-Il Jung Heon Kim Chul Sung Park Ji Chan 《Nano Research》2019,12(10):2568-2575
Nano Research - Iron-based nanoparticles with uniform and high particle dispersion, which are supported on carbon structures, have been used for various applications. However, their preparation... 相似文献
965.
Seung-Min Lee Wonchul Choi Junsoo Kim Taekwang Kim Jaewoo Lee Sol Yee Im Jung Yoon Kwon Sunae Seo Mincheol Shin Seung Eon Moon 《International Journal of Thermophysics》2017,38(12):176
On Si and sapphire substrates, 6–45 nm thick films of atomic layer-deposited Al\(_{2}\)O\(_{3}\) were grown. The thermal conductivity of ALD films has been determined from a linear relation between film thickness and thermal resistance measured by the 3\(\omega \) method. ALD films on Si and sapphire showed almost same thermal conductivity in the temperature range of 50–350 K. Residual thermal resistance was also obtained by extrapolation of the linear fit and was modeled as a sum of the thermal boundary resistances at heater–film and film–substrate interfaces. The total thermal resistance addenda for films on sapphire was close to independently measured thermal boundary resistance of heater–sapphire interface. From the result, it was deduced that the thermal boundary resistance at ALD Al\(_{2}\)O\(_{3}\)–sapphire interface was much lower than that of heater–film. By contrast, the films on Si showed significantly larger thermal boundary resistance than films on sapphire. Data of \(< 30\) nm films on Si were excluded because an AC coupling of electrical heating voltage to semiconductive Si complicated the relation between 3\(\omega \) voltage and temperature. 相似文献
966.
Shou-Cang Shen Wai Kiong Ng Jun Hu Kumaran Letchmanan Junwei Ng Reginald Beng Hee Tan 《Advanced Powder Technology》2017,28(5):1316-1324
To improve the dissolution properties of poorly water soluble active pharmaceutical ingredients (APIs), a solvent-free melt-absorption process was applied to directly load the APIs into mesoporous SBA-15 silica powder as an amorphous solid dispersion. Two model compounds, poorly aqueous soluble ibuprofen (IBU) and fenofibrate (FEN), were individually mixed with SBA-15 powder and heated above their respective melting points. Upon cooling, the physicochemical and solid-state properties of the solid dispersions were investigated by N2 adsorption, DSC, XRD, SEM and solid-state NMR. The molten API was found to be absorbed into the pores, confined within the nano-channels of SBA-15, and re-solidified to an amorphous solid dispersion. Due to the amorphous properties, the APIs showed a significant enhancement in dissolution rate as compared with the untreated crystalline APIs. Although the amorphous forms were not at thermodynamic equilibrium, the APIs exhibited excellent solid-state physical stability even under accelerated stress conditions. In comparison with APIs loaded using a co-spray drying process (previous work), the melt-absorption process required no organic solvent, produced powders with a coarser size distribution and more desirable flow properties. This solvent-free direct melt-absorption process can be used to formulate a wide range of poorly soluble drugs to be amorphous solid dispersions. 相似文献
967.
968.
The Effect of Coating Process and Additives on EVA Coated Tyvek® for Gas Sterilizable Medical Packaging Applications
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Hyok Kwon Dowan Kim Kang‐dae Lee Jongchul Seo Hwal‐Jong Lee 《Packaging Technology and Science》2017,30(5):195-208
Tyvek®, as an ethylene oxide (EtO) gas sterile medical packaging material with a high‐gas permeation and serving as an excellent microbial barrier, must be coated with heat‐sealable adhesives to thermally seal various plastic packaging trays or films. Tyvek® sheet coated with heat‐sealable adhesives must have both porous structure and good sealing strength to various substrates. In this study, an acid pre‐coating method was distinctively introduced to minimize reactions between the blowing agent and acid during mixing, to resultantly generate ethyl vinyl acetate (EVA) layers with porous structure on Tyvek® sheets. To determine the feasibility of applying the as‐prepared coated Tyvek® as a sterile medical packaging material, we investigated the properties of the coating solution and coated Tyvek® as a function of process and additive composition. Finally, EtO gas sterilization tests were performed, and property changes in the coated Tyvek® were investigated. Properties of the coated Tyvek® were strongly dependent on the pre‐coating process and the composition of various additives. Pre‐coating with citric acid led to less of a reaction between citric acid and ammonium carbonate as a blowing agent during mixing and resulted in both good seal strength and air permeation for the coated Tyvek® sheets. The coated Tyvek® sheets, composed of a water‐based EVA emulsion solution with various additives, were not affected by the EtO sterilization process and yielded good resistance to humidity, EtO gas and vacuum cycles. The coated Tyvek® sheets prepared by applying an acid pre‐coating may be a promising candidate for gas sterilizable medical device packaging materials. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
969.
Micron-sized porous composite particles composed of CeO2 and SiO2 nanoparticles were prepared for a UV absorption application by an aerosol spray-drying process from as-prepared CeO2 nanoparticles, commercial SiO2, and a polystyrene latex template. The morphology, structure crystallinity and pore size distribution of the as-prepared porous CeO2SiO2 composite particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Barrett-Joyner-Halenda (BJH) method, respectively. The porous CeO2SiO2 composite particles, with diameters of approximately 10 μm, showed a spherical morphology. As the contents of CeO2 in the precursor was increased from 0.25 wt% to 1.5 wt%, we observed a change in the morphology of the composite particles from compactly packed porous particles to loosely packed porous particles. The as-prepared CeO2SiO2 composite particles were composed of meso- and macropores in the range of 3–200 nm. The effect of the CeO2 content on the porous composite particles in terms of the UV absorption properties was also investigated by UV-visible spectroscopy. When the content of CeO2 exceeded 0.75 wt% in the precursor, the particles showed higher UV absorption values compared to those of commercial TiO2 nanoparticles. The as-prepared porous CeO2SiO2 composite particles can therefore be promising materials given their high UV absorption value. 相似文献
970.
Interface Control of Ferroelectricity in an SrRuO3/BaTiO3/SrRuO3 Capacitor and its Critical Thickness
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Yeong Jae Shin Yoonkoo Kim Sung‐Jin Kang Ho‐Hyun Nahm Pattukkannu Murugavel Jeong Rae Kim Myung Rae Cho Lingfei Wang Sang Mo Yang Jong‐Gul Yoon Jin‐Seok Chung Miyoung Kim Hua Zhou Seo Hyoung Chang Tae Won Noh 《Advanced materials (Deerfield Beach, Fla.)》2017,29(19)
The atomic‐scale synthesis of artificial oxide heterostructures offers new opportunities to create novel states that do not occur in nature. The main challenge related to synthesizing these structures is obtaining atomically sharp interfaces with designed termination sequences. In this study, it is demonstrated that the oxygen pressure during growth plays an important role in controlling the interfacial terminations of SrRuO3/BaTiO3/SrRuO3 (SRO/BTO/SRO) ferroelectric (FE) capacitors. The SRO/BTO/SRO heterostructures are grown by a pulsed laser deposition method. The top SRO/BTO interface, grown at high (around 150 mTorr), usually exhibits a mixture of RuO2–BaO and SrO–TiO2 terminations. By reducing , the authors obtain atomically sharp SRO/BTO top interfaces with uniform SrO–TiO2 termination. Using capacitor devices with symmetric and uniform interfacial termination, it is demonstrated for the first time that the FE critical thickness can reach the theoretical limit of 3.5 unit cells. 相似文献