a two-dimensional single particle finite element model was used to examine the effects of particle fragmental pattern on the average molecular weights, polymerization rate and particle overheating in heterogeneous ziegler-natta olefin polymerization. a two-site catalyst kinetic mechanism was employed together with a dynamic two-dimensional molecular species in diffusion-reaction equation. the i...

We propose a local heating method via molecular dynamic simulation to investigate the charge transport efficiency along a polypeptide chain in the gas phase. In the protein charge transfer process, the carbonyl groups next to a Cα-hinge collide with each other. Within a critical contact distance between O–O atoms, charge starts to transfer otherwise the charge being at rest. This is termed a bi...

In this paper we develop an approach for planning under time and resource uncertainty with task dependencies. We follow the line of research described by (Bresina et al., 2002), overcoming limitations of existing approaches: they only handle simple time constraints and assume a simple model of durations and resources’ uncertainty.In many domains, such as space applications (rovers, satellites),...

A 14-bit 200MS/s current-steering DAC with a novel digital calibration technique called dynamic-mismatch mapping (DMM) is presented. Compared to traditional static-mismatch mapping and dynamic element matching, DMM reduces the nonlinearities caused by both amplitude and timing errors, without noise penalty. This 0.14μm CMOS DAC achieves a state-of-the-art performance of SFDR>78dBc, IM3<-83dBc a...

w       ater born poly(styrene-butyl acrylate)/clay nanocomposite latexes were synthesized by a novel initiating system of activators generated by   electron transfer (aget) in a system of atom transfer radical polymerization   (atrp). initially, the clay was swelled in a mixture of styrene, butyl acrylate,   and hexadecane. the mixture was then sonicated to obtain a stable miniemulsion. to   s...

A new method is proposed for correctly modeling the long range interaction between a fluid and a bounding wall in atomistic simulations. This method incorporates the molecular structure of the solid substrate while allowing for a finite interaction cutoff by making a proper estimation of long range correction for the fluid-wall interaction. The method is then applied to a molecular dynamic simu...

We derive a lower bound for the staang levels required to meet a projected load in a retail service facility. We model the queueing system as a Markovian process with non-homogeneous Poisson arrivals. Motivated by an application from the postal services, we assume that the arrival rate is piecewise constant over the time horizon and retain such transient eeects as build-up in the system. The op...

Human immunodeficiency virus type 1 (HIV-1) protease inhibitors comprise an important class of drugs used in HIV treatments. However, mutations of protease genes accelerated by low fidelity of reverse transcriptase yield drug resistant mutants of reduced affinities for the inhibitors. This problem is considered to be a serious barrier against HIV treatment for the foreseeable future. In this st...