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11.
In this research, the main purpose is to formulate a model to determine the optimum investment on port development from national investment prospective; on the other hand, costs and benefits are calculated from consumer and investor’s viewpoint. The formulated model is an integer-programming model. The emphasis is on how to formulate an investment optimization problem where cargo operation, investment costs, cargo-handling capacity, cargo transportation network, and the world maritime fleet constraints are included. Fuzzy numbers are used for cargo forecast study results. The output of the model is the type of design ships and design berths which are needed in each sub period, so that the port planner (the government) will find out the optimum development plan of port in each sub period when there is uncertainty in cargo handling forecast (fuzzy numbers).  相似文献   
12.
Dimethylmaleoyl (DMM) moiety has become an important amine protective group in sugar chemistry. We disclose herein that DMM-containing D-glucosamine analogues, because of their electrophilic nature, are prone to reactions with strong nucleophiles, such as hydrazine, resulting in a set of undesired side products that are difficult to detect, yet proved to be problematic for organic synthesis.  相似文献   
13.
<正>Two new eudesmane derivatives were isolated from the leaves and flowers of Verbesina virginica,along with the known 6-O-β-E -p-coumaroyl-4α-hydroxyeudesmane(1).Their structures were determined as 6-O-β-Z-p-coumaroyl-4α-hydroxyeudesmane(2) and 6-O-α-E-p-coumaroyl-1β-4α-dihydroxyeudesmane(3) by spectroscopic methods.  相似文献   
14.
Ferrofluid spin-up flow is studied within a sphere subjected to a uniform rotating magnetic field from two surrounding spherical coils carrying sinusoidally varying currents at right angles and 90° phase difference. Ultrasound velocimetry measurements in a full sphere of ferrofluid shows no measureable flow. There is significant bulk flow in a partially filled sphere (1-14 mm/s) of ferrofluid or a finite height cylinder of ferrofluid with no cover (1-4 mm/s) placed in the spherical coil apparatus. The flow is due to free surface effects and the non-uniform magnetic field associated with the shape demagnetizing effects. Flow is also observed in the fully filled ferrofluid sphere (1-20 mm/s) when the field is made non-uniform by adding a permanent magnet or a DC or AC excited small solenoidal coil. This confirms that a non-uniform magnetic field or a non-uniform distribution of magnetization due to a non-uniform magnetic field are causes of spin-up flow in ferrofluids with no free surface, while tangential magnetic surface stress contributes to flow in the presence of a free surface.Recent work has fitted velocity flow measurements of ferrofluid filled finite height cylinders with no free surface, subjected to uniform rotating magnetic fields, neglecting the container shape effects which cause non-uniform demagnetizing fields, and resulting in much larger non-physical effective values of spin viscosity η′∼10−8−10−12 N s than those obtained from theoretical spin diffusion analysis where η′≤10−18 N s. COMSOL Multiphysics finite element computer simulations of spherical geometry in a uniform rotating magnetic field using non-physically large experimental fit values of spin viscosity η′∼10−8−10−12 N s with a zero spin-velocity boundary condition at the outer wall predicts measureable flow, while simulations setting spin viscosity to zero (η=0) results in negligible flow, in agreement with the ultrasound velocimetry measurements. COMSOL simulations also confirm that a non-uniform rotating magnetic field or a uniform rotating magnetic field with a non-uniform distribution of magnetization due to an external magnet or a current carrying coil can drive a measureable flow in an infinitely long ferrofluid cylinder with zero spin viscosity (η=0).  相似文献   
15.
Four distinct elements a, b, c, and d of a poset form a diamond if \(a< b and \(a . A subset of a poset is diamond-free if no four elements of the subset form a diamond. Even in the Boolean lattices, finding the size of the largest diamond-free subset remains an open problem. In this paper, we consider the linear lattices—poset of subspaces of a finite dimensional vector space over a finite field of order q—and extend the results of Griggs et al. (J. Combin. Theory Ser. A 119(2):310–322, 2012) on the Boolean lattices, to prove that the number of elements of a diamond-free subset of a linear lattice can be no larger than \(2+\frac {1}{q+1}\) times the width of the lattice, so that this fraction tends to 2 as \(q \longrightarrow \infty \) . In addition, using an algebraic technique, we introduce so-called diamond matchings, and prove that for linear lattices of dimensions up to 5, the size of a largest diamond-free subset is equal to the sum of the largest two rank numbers of the lattice.  相似文献   
16.
The dynamics of single droplets in a bounded shear flow is experimentally and numerically investigated for blends that contain one viscoelastic component. Results are presented for systems with a viscosity ratio of 1.5 and a Deborah number for the viscoelastic phase of 1. The numerical algorithm is a volume-of-fluid method for tracking the placement of the two liquids. First, we demonstrate the validation of the code with an existing boundary integral method and with experimental data for confined systems containing Newtonian components. This is followed by numerical simulations and experimental data for the combined effect of geometrical confinement and component viscoelasticity on the droplet dynamics after startup of shear flow at a moderate capillary number. The viscoelastic liquids are Boger fluids, which are modeled with the Oldroyd-B constitutive model and the Giesekus model. Confinement substantially increases the viscoelastic stresses and the elongation rates in and around the droplet. We show that the latter can be dramatic for the use of the Oldroyd-B model in confined systems with viscoelastic components. A sensitivity analysis for the choice of the model parameters in the Giesekus constitutive equation is presented.  相似文献   
17.
In prostate cancer, hormone therapy via leuprolide acetate drug (LUP) is used to lower the level of testosterone down to castration level to effectively control the development of prostate cancer. The objective of this study was to evaluate the effective parameters in degradation and controlled release of an injectable in situ formed polymeric implant, loaded with leuprolide acetate, in order to achieve an optimum formulation for sustained drug release for 90 days with minimum burst release. The main problem associating with such implants is their high burst release. Designing an injectable implant with sustained and minimum burst release has thus become an attractive challenge in drug delivery field. Effects of type of poly(lactic‐co‐glycolic acid) 75:25 copolymers (RG752, RG756) and addition of nano‐hydroxyapatite (HA) particles on degradation rates of the implants and release profiles were examined in vitro and in vivo in a rabbit animal model. Results showed that implants containing polymers with higher molecular weights had significantly lower weight loss and molecular weight reduction. Adding nanoparticles of hydroxyapatite into poly(lactic‐co‐glycolic acid) implants caused further reduction in degradation rates, leading to a more sustained drug release in vivo, with reduced burst release. Different conventional kinetic models were applied to drug release and degradation data. The degradation data fit well to the first‐order degradation model. Higuchi model was the best kinetic release model fitted to the experimental in vitro release data. This study led to an optimum formulation (RG756:RG752 3:1 + 5% HA) with sustained leuprolide release and testosterone suppression over a 90‐day period with significant decrease of burst release phase (50%, p < 0.001) compared with the conventional Eligard formulation. The histopathology test showed that the formulated implant had no effects of toxicity or tissue necrosis in organs of the animal model. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   
18.
In this paper, a new optimization method has been proposed for accident prediction non-linear models. This has been achieved by eliminating the Hessian matrix from the equation of optimal pace length in the gradient vector method. One advantage is that it is independent of the starting point in optimization processes and it provides convergence at the highest top as well. This method has been tested on an accident prediction model and its preference over the gradient vector method has been proven.  相似文献   
19.
Ultrasound-assisted headspace solid-phase microextraction (UA-HS-SPME) coupled to gas chromatography–mass spectrometry (GC–MS) has been used for analysis of volatile compounds in dry Tagetes minuta L. The highest extraction efficiency was achieved with a 100-μm polydimethylsiloxane (PDMS) fiber. Different experimental conditions, for example, type of fiber coating, sonication time, extraction time and temperature, and desorption time, were investigated. Thirty compounds were identified by use of this UA-HS-SPME–GC–MS method. Comparison of the method with the commonly used hydrodistillation (HD) method showed that the proposed method is simpler, needs much less sample, requires shorter extraction time and lower temperature, has high trapping ability, and extracts more volatile and thermally sensitive compounds. The major components identified by use of the method were e-ocimenone (10.3%), cis-β-ocimene (4.8%), α-terpinolene (8.4%), trans-caryophyllene (19.7%), germacrene-d (10.0%), and camphor (3.6%).  相似文献   
20.
The chromone and flavonoid alkaloids represent an unusual group of structurally diverse secondary metabolites, derived from the convergence of multiple biosynthetic pathways that are widely distributed through the plant and animal kingdoms. Many of them have been discovered through bioassay-guided chemical investigations of traditional medicines, suggesting potential therapeutic significance. Their unique structures and varied pharmacological activities may provide important new leads for the discovery of drugs with novel mechanisms of action. Potential therapeutic indications are as diverse as cancer and viral infections, inflammation and immunomodulation, neurological and psychiatric conditions, and diabetes.  相似文献   
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