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101.
I. Gallego 《CIRP Annals》2007,56(1):347-352
Centerless grinding productivity is largely limited by three types of instabilities: chatter, geometric lobing and workpiece rotation problems. Regardless of its negative effect in manufacturing plants, no functional tool has been developed to set up the process, because it involves the simultaneous resolution of several coupled problems. In this paper, new simulation techniques are described to determine instability-free configurations, making it possible to guarantee that the final workpiece profile is round. With this information and taking into account other process restrictions, like system static stiffness and workpiece tolerance, the optimal grinding cycle is designed. These results have been implemented into an intelligent tool to assist the application of this research in industrial environments. 相似文献
102.
Fuzzy modeling has been widely applied as a powerful methodology for the identification of nonlinear systems from process measurements. In particular, the design of black‐box approaches based on fuzzy models has been recognized as an alternative to mathematical methods. This article deals with the application of modeling and identification techniques for obtaining two fuzzy models of a solar domestic hot water system. The models have been generated in order to estimate the energy supplied by a thermal solar system and the output temperature of the water, respectively. The methods have been applied by using only the experimental input/output data taken from the process. © 2002 Wiley Periodicals, Inc. 相似文献
103.
Lizhen Chen Lars Klemeyer Mingbo Ruan Xin Liu Stefan Werner Weilin Xu Andrea Koeppen Robert Bücker Marta Gallego Gonzalez Dorota Koziej Wolfgang J. Parak Indranath Chakraborty 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(19):2206772
Nanozymes are nanomaterials with biocatalytic properties under physiological conditions and are one class of artificial enzymes to overcome the high cost and low stability of natural enzymes. However, surface ligands on nanomaterials will decrease the catalytic activity of the nanozymes by blocking the active sites. To address this limitation, ligand-free PtAg nanoclusters (NCs) are synthesized and applied as nanozymes for various enzyme-mimicking reactions. By taking advantage of the mutual interaction of zeolitic imidazolate frameworks (ZIF-8) and Pt precursors, a good dispersion of PtAg bimetal NCs with a diameter of 1.78 ± 0.1 nm is achieved with ZIF-8 as a template. The incorporation of PtAgNCs in the voids of ZIF-8 is confirmed with structural analysis using the atomic pair-distribution function and powder X-ray diffraction. Importantly, the PtAgNCs present good catalytic activity for various enzyme-mimicking reactions, including peroxidase-/catalase- and oxidase-like reactions. Further, this work compares the catalytic activity between PtAg NCs and PtAg nanoparticles with different compositions and finds that these two nanozymes present a converse dependency of Ag-loading on their activity. This study contributes to the field of nanozymes and presents a potential option to prepare ligand-free bimetal biocatalysts with sizes in the nanocluster regime. 相似文献
104.
F.?Pe?a S.?Cárdenas M.?Gallego M.?ValcárcelEmail author 《Journal of the American Oil Chemists' Society》2003,80(6):613-618
Hexane is used to extract edible oils from oleaginous seeds. The detection of hexane in orujo oil is mandatory, as its presence
in the final product may negatively affect human health. Headspace-GC is the technique of choice for determining residual
solvent in foods. In the present work, a new instrument based on the headspace principle and mass spectrometric detection
without chromatographic separation, ChemSensor, is proposed for the direct screening of orujo oil to determine residual hexane.
This instrument provided an overall response, corresponding to the volatiles profile, including that of hexane, which could
not be directly discriminated. By selecting the m/z values corresponding to n-hexane (major component of commercial hexane), the selectivity of the method was good enough to determine residual hexane
in the range of 2.0–65 μg mL−1 (corresponding to 2.3–75.6 mg of hexane per kg of oil) with high precision. The detection limit achieved (0.7 mg per kg of
oil) was lower than the maximum residual limit established by the European Union (5 mg per kg of oil). Two multivariate techniques,
partial least squares and principal components regression (PCR), were compared with univariate regression; PCR provided the
best results. 相似文献
105.
Juan Gallego Ana María Rodríguez-Alloza Felice Giuliani 《Mechanics of Time-Dependent Materials》2016,20(3):389-403
Warm mix asphalt (WMA) is a new research topic in the field of road pavement materials. This technology allows lower energy consumption and greenhouse gas (GHG) emissions by reducing compaction and placement temperatures of the asphalt mixtures. However, this technology is still under study, and the influence of the WMA additives has yet to be investigated thoroughly and clearly identified, especially in the case of crumb rubber modified (CRM) binders.In order to study the effect that different types and quantities of organic waxes have on the high and intermediate temperature properties of 15 % and 20 % CRM binders, a dynamic shear rheometer (DSR) was used. Using Black diagrams, the rheological behaviour of the binders for the defined range of test temperature and frequency are summarised in a single diagram. In this way, a preliminary evaluation of the rheological behaviour in the extended domain of time and temperature can be attained as well as the effectiveness of the time–temperature superposition principle (TTSP) on the materials under study. Creep tests were also performed in order to evaluate the differences regarding mechanical response due to the addition of rubber and WMA additives, and particularly the ability to recover the strain at high temperatures.The results of this study reveal that these binders do not conform to the Time Temperature Superposition Principle (TTSP) and their rheological behaviour is strongly affected by the interaction of waxes and bituminous matrix and thus generally exhibited a higher elasticity compared to the corresponding control binder. The creep test results carried out proved the enhancement of elasticity and the resistance to permanent deformation produced by the addition of waxes. The WMA additives significantly lower the maximum deformation when compared to the control binders and slightly increased their elastic recovery. 相似文献
106.
Controllable Large‐Scale Transfection of Primary Mammalian Cardiomyocytes on a Nanochannel Array Platform 下载免费PDF全文
Lingqian Chang Daniel Gallego‐Perez Chi‐Ling Chiang Paul Bertani Tairong Kuang Yan Sheng Feng Chen Zhou Chen Junfeng Shi Hao Yang Xiaomeng Huang Veysi Malkoc Wu Lu Ly James Lee 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(43):5971-5980
While electroporation has been widely used as a physical method for gene transfection in vitro and in vivo, its application in gene therapy of cardiovascular cells remains challenging. Due to the high concentration of ion‐transport proteins in the sarcolemma, conventional electroporation of primary cardiomyocytes tends to cause ion‐channel activation and abnormal ion flux, resulting in low transfection efficiency and high mortality. In this work, a high‐throughput nanoelectroporation technique based on a nanochannel array platform is reported, which enables massively parallel delivery of genetic cargo (microRNA, plasmids) into mouse primary cardiomyocytes in a controllable, highly efficient, and benign manner. A simple “dipping‐trap” approach was implemented to precisely position a large number of cells on the nanoelectroporation platform. With dosage control, our device precisely titrates the level of miR‐29, a potential therapeutic agent for cardiac fibrosis, and determines the minimum concentration of miR‐29 causing side effects in mouse primary cardiomyocytes. Moreover, the dose‐dependent effect of miR‐29 on mitochondrial potential and homeostasis is monitored. Altogether, our nanochannel array platform provides efficient trapping and transfection of primary mouse cardiomyocyte, which can improve the quality control for future microRNA therapy in heart diseases. 相似文献
107.
Centerless grinding is a high precision manufacturing process commonly applied to the mass production of many industrial components. However, workpiece roundness is critically affected by geometric lobing and no practical tool has been developed to solve the problem in throughfeed working mode. Based on simulation methods previously applied to plunge grinding, a new software tool has been developed in this work. The software determines the optimal working configuration and can be used to reduce set-up time and improve three important features: 1) Precision, as the roundness error is rapidly corrected at the optimal configuration. 2) Productivity, since the workpiece stock can be significantly reduced. 3) Stability, because the process is less sensitive to the original roundness error of the workpiece. 相似文献
108.
109.
J. Lpez R. Navarro J.M. Gallego F. Parres S. Ferrndiz 《Engineering Failure Analysis》2009,16(7):2217-2223
In the injection molding process defective pieces are sometimes detected, showing weak points which break easily. In this work, the possible causes of these failure points are evaluated. Thermal analysis techniques were applied to the material to better understand the degradation that takes place with relation to the transformation process. Simulations were made to determine the possible causes of deterioration and at the same time reproduce the effects of this fragility. The creation of the weak points was simulated and their origins were determined. 相似文献
110.
G Dudziak S Zeng EG Berger RG Gallego JP Kamerling U Kragl C Wandrey 《Canadian Metallurgical Quarterly》1998,8(18):2595-2598
beta-Galactosidase from bovine testes was used in a one pot reaction together with a recombinant beta-1,6-GlcNAc transferase for the synthesis of GlcNAc(beta 1-6)GalNAc(alpha 1-OBn) (core 6-Bn). The galactosidase, which reversibly links galactose via a (beta 1-3) linkage to N-acetylgalactosamine, provides the substrate for the GlcNAc transferase in situ. The synthesis was carried out with a yield > 90%. 相似文献