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51.
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《Calphad》2021
Decades of scientific work dedicated to the investigation of phase diagrams gave significant benefit to industry and science. After all those years of phase diagram investigation still there is missing information about phase diagram of some ternary systems. One of those systems is Cu-Ge-Pb. It is known importance of Cu-based alloys and Ge-based alloys in electro industry. Since such combination is not tested before this work will provide information about phase diagram of ternary Cu-Ge-Pb system. In this work ternary Cu-Ge-Pb system has been tested experimentally and analytically by using Calphad model. Two isothermal sections at 600 and 400 °C and three vertical sections are experimentally tested and results were compared with calculated corresponding phase diagrams. None of the ternary compound and large solubility of third element in binary compound is not confirmed. Liquidus projection, invariant reaction and scheme of invariant reaction are presented. Scheil and Lever simulation of solid phases for Cu80Ge10Pb10 alloy were calculated. 相似文献
53.
Tomasz Osmałek Bartłomiej Milanowski Anna Froelich Mirosław Szybowicz Wojciech Białowąs Marcin Kapela 《Drug development and industrial pharmacy》2017,43(8):1314-1329
The aim of the presented work was to design, formulate and evaluate the properties of low-acyl gellan macro beads with the potential application as carriers for oral delivery of meloxicam (MLX) in the prophylaxis of colorectal cancer. The beads were obtained by means of ionotropic gelation technique. Calcium chloride (1.0%, 9.0?×?10?2 M) was used as the cross-linking agent. Nine different polymer, drug and surfactant (Tween®80) mixtures were used for production of the beads. The quantitative compositions of the mixtures were generated with the application of the Design of Experiments (DoE) modulus from the STATISTICA Software. The prepared formulations revealed 7.2–27.0% of drug loading and 29.2–50.7% drug encapsulation efficiency. It turned out that 0.5% amount of gellan gum in the mixtures was not sufficient to obtain spherical beads. The morphology and surface of the dried beads were analyzed by SEM. Raman spectra confirmed that MLX did not undergo structural changes during production of the beads. The swelling behavior and degradation of the beads were evaluated in three simulated gastrointestinal fluids at different pH (1.2; 4.5; 6.8). The MLX in vitro release studies were conducted on USP apparatus IV, working in the open loop mode. The obtained results showed that MLX release from the dried beads was pH-dependent. The formulations obtained from mixtures containing 1.0 and 1.5% of gellan may be considered as oral dosage forms for MLX, intended to omit the stomach and release the drug in the distal parts of the gastrointestinal tract. 相似文献
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In the hardware-in-loop simulation of aero-engine control system where the real fuel regulator is engaged, it's crucial to measure the real-time flow rate. In view of this, a flow meter with high precision and fast response is important. In this paper, modeling and experiments are conducted to verify the dynamic characteristics of a turbine flow meter (TFM). For the modeling part, driving torque and resistance torques are analyzed to derive the kinetic equation of TFM. Simulation with the kinetic equation shows good dynamic performance of TFM. In experiments, a workbench is designed to generate step-type flow and sine-type flow for identification in time domain and frequency domain. Results show that the settling time for TFM is no more than 100 ms and its band-with is over 4.61 Hz. Compared with the settling time of a main fuel valve and the band-width of a main fuel control loop, that is, 1.2 s and 2 Hz respectively, TFM is considered to be adaptive to measure the fuel of aero-engine. 相似文献
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Theodore Spyropoulos 《Architectural Design》2009,79(6):82-87
Over the last four decades, the onset of computation has enabled architects and designers to employ generative patterns in their exploration of emergent social, material and spatial systems. Theodore Spyropoulos provides an overview of the field and discusses how it has been developed by the Design Research Lab (DRL) at the Architectural Association into an ‘Adaptive Ecologies’ agenda. In the context of parametric urbanism, the DRL has explored models of living through behavioural patterns found in nature, examining the role of the singular and the collective. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
58.
Mohammad A. Rakib John R. Grace Said S.E.H. Elnashaie 《Journal of power sources》2010,195(17):5749-3129
n-Heptane served as a model compound to study steam reforming of naphtha as an alternative feedstock to natural gas for production of pure hydrogen in a fluidized bed membrane reactor. Selective removal of hydrogen using Pd77Ag23 membrane panels shifted the equilibrium-limited reactions to greater conversion of the hydrocarbons and lower yields of methane, an intermediate product. Experiments were conducted with no membranes, with one membrane panel, and with six panels along the height of the reactor to understand the performance improvement due to hydrogen removal in a reactor where catalyst particles were fluidized. Results indicate that a fluidized bed membrane reactor (FBMR) can provide a compact reformer for pure hydrogen production from a liquid hydrocarbon feedstock at moderate temperatures (475-550 °C). Under the experimental conditions investigated, the maximum achieved yield of pure hydrogen was 14.7 moles of pure hydrogen per mole of heptane fed. 相似文献
59.
W. Wongsuwan 《国际可持续能源杂志》2013,32(2):69-86
The design and applicability of solar water heating systems requires a satisfactory prediction of collector outlet water temperature and the useful energy delivered over a wide range of climatic conditions. Transient system simulation program is extensively used for this purpose, and recently artificial neural networks have also been considered. This article presents the results of a study carried out to compare the performance prediction by these two methods in a tropical location under different climatic conditions. Experimental collector outlet temperature, storage tank temperatures and the useful energy values were compared with the results of the simulation by these two methods. Hourly and daily values under different conditions were also compared. Details of the experimental set up and observations, the modeling procedure used and the statistical measures to compare the capabilities of the two methods under clear, partly cloudy, and cloudy conditions have been described. The prediction of both the methods are found to be good for both hourly and daily estimations, and the specific requirements for satisfactory performance prediction of each of the methods have been detailed. 相似文献
60.
A technique for empirical optimisation is presented in which a sequence of experimental designs each in the form of a regular or irregular simplex is used, each simplex having all vertices but one in common with the preceding simplex, and being completed by one new point. Reasons for the choice of design are outlined, and a formal procedure given. The performance of the technique in the presence and absence of error is studied and it is shown (a) that in the presence of error the rate of advance is inversely proportional to the error standard deviation, so that replication of observations is not beneficial, and (b) that the “efficiency” of the technique appears to increase in direct proportion to the number of factors investigated. It is also noted that, since the direction of movement from each simplex is dependent solely on the ranking of the observations, the technique may be used even in circumstances when a response cannot be quantitatively assessed. Attention is drawn to the ease with which second-order designs having the minimum number of experimental points may be derived from a regular simplex, and a fitting procedure which avoids a direct matrix inversion is suggested. In a brief appendix one or two new rotatable designs derivable from a simplex are noted. 相似文献