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651.
The stereoscopic molecular tagging velocimetry (SMTV) technique is used to obtain the multiple point measurement of an instantaneous
three-component velocity field inside the cylinder of an internal combustion (IC) engine assembly. A novel image processing
technique is implemented to obtain the velocity data. The technique has the advantage that it eliminates the geometric details
required to obtain the three components of the velocity field. The procedure involves two major steps: (i) calibration process
and (ii) data acquisition and reduction. Cycle-to-cycle variations of the three-component velocity field and out-of-plane
vorticity are presented inside an engine cylinder. Preliminary results show that cycle-to-cycle variations are more prominent
in the velocity component perpendicular to the tumble plane, as opposed to the in-plane components. Such new insights will
help better understand the details of these flows and further improve CFD models for IC engines. 相似文献
652.
Inverse dynamics of a general model of a spherical star-triangle (SST) parallel manipulator (Enferadi and Akbarzadeh Tootoonchi,
Robotica 27:663–676, 2009) is the subject of this paper. This manipulator is of type 3-RRP, has good accuracy and relatively a large workspace which
is free of singularities (Enferadi and Akbarzadeh Tootoonchi, Robotica, Revised paper, 2009). First, inverse kinematics utilizing the angle axis representation is solved. Next, velocity and acceleration analysis as
well as link Jacobian matrices are obtained in invariant form. Finally, a systematic approach based on the principle of virtual
work and the concept of link Jacobian matrices is presented. This method allows elimination of constraint forces and moments
at the passive joints from motion equations. It is shown that the dynamics of the manipulator can be reduced to solving a
system of three linear equations with three unknowns. Moreover, a computational algorithm for solving the inverse dynamics
is developed. Two examples with different trajectories for the moving spherical platform are presented and motor torques are
obtained. Results are verified using a commercial dynamics modeling package. 相似文献
653.
Javad Azizian Mohammad R. Mohammadizadeh Ali A. Mohammadi Ali R. Karimi Fatemeh Teimouri 《Heteroatom Chemistry》2007,18(1):16-18
A novel one‐pot procedure for preparation of some new condensed pyrido[2,3‐d]pyrimidine(1H,3H)‐2,4‐diones based on condensation of ninhydrin, alkyl cyanoacetate, and 6‐aminouracil derivatives has been reported. The reactions were carried out in refluxed ethanol and were completed in less than 2 h. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:16–18, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20242 相似文献
654.
Azizian J Mohammadi AA Karimi AR Mohammadizadeh MR 《The Journal of organic chemistry》2005,70(1):350-352
KAl(SO(4))(2).12H(2)O is found to catalyze efficiently the stereoselective one-pot three-component cyclocondensation of homophthalic anhydride, aldehydes, and amines under mild conditions to afford the corresponding cis-isoquinolonic acids in good yields. 相似文献
655.
This study reports the development of a production scheduling system for the integrated management of production in large-scale, high-volume electronic assembly lines. The development of the system incorporates control and planning considerations by addressing the interaction of various subsystems. Stochastic and deterministic aspects of the problem environment are appropriately handled via relevant simulation and analytic models. By effecting a hierarchical breakdown of the problem environment, the system produces information used in practical decision making for production planning and scheduling. Procedures used encompass and address considerations for management of work-in-process, optimization of the various subsystems' performance, minimization of setup time effect, and inventory carrying costs. 相似文献
656.
M. Javad Paknejad Farrokh Nasri John F. Affisco 《Mathematical Methods of Operations Research》1996,43(3):389-401
Recently, a framework for analyzing investment decisions as they relate to setup cost reduction in two stage production processes has appeared in the literature. Closed form results were developed for the case of logarithmic investment function. This paper extends the results to the case of power investment function. We present an algorithm for calculating the optimal values of the decision variables. A numerical example is utilized to reveal some interesting aspects of this system. 相似文献
657.
658.
Rahmani Ali Reza Poormohammadi Ali Zamani Fahime Tahmasebi Birgani Yaser Jorfi Sahand Gholizadeh Sepideh Mohammadi Mohammad Javad Almasi Halime 《Research on Chemical Intermediates》2018,44(9):5501-5519
Research on Chemical Intermediates - Due to its high toxicity, phenol is classified as a priority. In this paper, the removal of phenol from aqueous solutions was investigated using EDTA and... 相似文献
659.
This work reports the preparation of molecularly imprinted polymer (MIP) particles for selective extraction and determination of selenium ions from aqueous media. Polymerization was achieved in a glass tube containing SeO2, o-phenylenediamine, 2-vinylpyridine (VP), ethyleneglycoldimethacrylate (EDMA), 2,2′-azobisisobutyronitrile (AIBN). The polymer block obtained was ground and sieved (55-75 μm) and the Se-o-phenylenediamine complex was removed from polymer particles by leaching with 2 M of HCl, which leaves a cavity in the polymer particles. The polymer particles both prior to and after leaching have been characterized by IR and thermogravimetric (TG) studies. The effect of different parameters, such as pH, extraction time, type and least amount of eluent for elution of complex from polymer were evaluated. Extraction efficiencies >99% were obtained by elution of the polymers with 15 mL of methanol-acetonitrile mixture (1:2, v/v). The limit of detection of the proposed method followed by hydride generation atomic absorption spectroscopy (HG-AAS) was found to be 3.3 μg L−1 and a dynamic linear range (DLR) of 10-200 μg L−1 was obtained. The relative standard deviations (R.S.D.s) at 30.0 μg L−1 of Se were below than 8.1%. The influence of various cationic interferences on percent recovery of complex was studied. The method was applied to the recovery and determination of selenium in different real samples. 相似文献
660.
Seyyed Javad Sabounchei Hassan Nemattalab 《Journal of organometallic chemistry》2007,692(24):5440-5446
Reaction of phosphorus ylides of the type X-C6H4-COCHPAr3 (X = Cl and NO2; Ar = phenyl and p-tolyl) with Hg(NO3)2 · H2O in equimolar ratios using methanol as solvent are reported. X-ray crystal structure analysis of [Hg(ClC6H4C(O)CHPPh3)(NO3)(μ-NO3)]n · (DMSO)n shows that the 1:1 complex adopts the noncentrosymmetric polymeric structure in the solid state with NO-3 anion bridges. Variation of temperature or concentration in a 31P NMR study indicates that the disappearance of satellites, due to coupling to 199Hg, occurs at increasing temperature or decreasing concentration. 相似文献