Stress-concentration factors for multiple semielliptical notches in beams under pure bending

Uniformly spaced semielliptical notches in rectangular beams under pure bending are examined photoelastically. Minimum stress-concentration factors, produced by multiple elliptical notching of beams, are obtained for wide ranges of notch width, semiminor elliptical axis, notch depth, notch pitch and depth of beam. In particular, the geometries of the optimum elliptical notch producing the least stress concentration are obtained for a practical range of parameters. Stress-concentration factors for beams with multiple semi-elliptical notches are compared to those for beams with single semielliptical notches and to those for beams with semicircular notches. The maximum reduction of stress-concentration factor for beams with multiple semielliptical notches is to approximately 37 percent of the stress-concentration factor for beams with single semielliptical notches. Within the range of parameters investigated, the stress-concentration factor for beams with multiple semielliptical notches was 15 to 37 percent less than that for multiple semicircular notches.     

Application of a DPC for PMD Compensation in Environmental Perturbed Transmission System

Polarization mode dispersion (PMD) compensation is presented on environmental perturbed fiber-optical transmission system in this paper. We achieve a dynamic polarization controller (DPC) to feedback control the PMD, successfully.     

Effects of geometrical characteristics of surface roughness on droplet wetting

Surface roughness is known to alter the wettability on a solid substrate. In general, either Wenzel or Cassie-Baxter theory is adopted to describe the apparent contact angle. Following the minimum free energy pathway associated with the imbibition process, we have derived a generalized expression for the apparent contact angle on a textured surface and the liquid-gas contact area within the groove that plays a key role. Depending on the geometrical characteristics of the grooves, the surface wetting falls into three regimes: (i) single stable state which is either Wenzel (completely wetted roughness) or Cassie-Baxter (completely nonwetted roughness) state, (ii) two stable states (Wenzel and Cassie-Baxter) separated by an energy barrier, and (iii) single stable state with partially wetted roughness. The sufficient condition for each regime is derived and several groove geometries are given to show the free energy path. Alteration in the geometric parameters may lead to the wetting crossover. We also show that the Cassie-Baxter can occur at a hydrophilic surface for particular pore shapes.     

Effects of multivalent salt addition on effective charge of dilute colloidal solutions

The effective charge Z* is often invoked to account for the accumulation of counterions near the colloid with intrinsic charge Z. Although the ion concentrations c(i) are not uniform in the solution due to the presence of the charged particle, their chemical potentials are uniform everywhere. Thus, on the basis of ion chemical potential, effective ion concentrations c(i)*, which can be experimentally measured by potentiometry, are defined with the pure salt solution as the reference state. The effective charge associated with the charged particle can then be determined by the global electroneutrality condition. Monte Carlo simulations are performed in a spherical Wigner-Seitz cell to obtain the effective charge of the colloid. In terms of the charge ratio alpha=Z*/Z, the effects of added salt concentration, counterion valency, and particle charge are examined. The effective charge declines with increasing salt concentration and the multivalent salt is much more efficient in reducing the effective charge of the colloidal solution. Moreover, the extent of effective charge reduction is decreased with increasing intrinsic charge for a given concentration of added salt. Those results are qualitatively consistent with experimental observations by electrophoresis.     

Effects of surfactant micelles on viscosity and conductivity of poly(ethylene glycol) solutions

The neutral polymer-micelle interaction is investigated for various surfactants by viscometry and electrical conductometry. In order to exclude the well-known necklace scenario, we consider aqueous solutions of low molecular weight poly(ethylene glycol) (2-20)x10(3), whose radial size is comparable to or smaller than micelles. The single-tail surfactants consist of anionic, cationic, and nonionic head groups. It is found that the viscosity of the polymer solution may be increased several times by micelles if weak attraction between a polymer segment and a surfactant exists, epsilon相似文献   

Confidence estimation for tolerance intervals

The post-data performances of normal tolerance intervals are studied. Under a robust Bayesian predictive scheme, we establish the ordering and bounds of the confidence estimators. It is found that the nominal confidence coefficient tends to be extreme yet coincides with the limiting Bayes estimators in some scenarios. A remark on the choice of beta priors is also given.     

Analysing consumer segments to budget for loyalty and promotion programmes and maximize market share

This paper seeks to provide a framework and benchmark for the allocation of marketing budget between promotion and loyalty programmes using an approach that combines a Markov-type market share model and the Lagrange multiplier method to maximize market share. The Lagrange multiplier method, that takes into account the market share and the loyalty effect observable in preceding periods along with the estimated promotional effects, permits the allocation to be optimized and future market share to be maximized. Then, loyalty-based consumer segment are used to explain why the budgeting exercise can achieve the maximization objective. To this end, the study uses consumer panel data concerning three categories, namely, adult milk powder, shampoo, and detergent. It extends previous research on loyalty-based segmentation by focusing on the budget allocation between the two options of loyalty enhancement and promotion programming. A Budget Allocation Grid for Loyalty-based Segmentation is proposed as an aid to understand budget allocation between loyalty and promotion programmes based on the relative sizes of exclusive-loyalty and variety-seeking segments.     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general procedure was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones by reaction of 3-formylchromone with aroylhydrazines, transformation of the corresponding acylhydrazones into 1,3-dipoles by the action of bromine in the presence of sodium acetate, and intramolecular ring closure.     

A Green BODIPY‐Based,Super‐Fluorogenic,Protein‐Specific Labelling Agent

We report the development of YC23, a novel green BODIPY‐based dimaleimide derivative that undergoes a fluorogenic addition reaction (FlARe) with a genetically encodable peptide tag (dC10α) that can be fused to a protein of interest (POI). We also demonstrate the application of this reaction for the fluorogenic labelling of a specific POI in bacterial lysate and in living mammalian cells.     

Improvement of productivity of yeast cell with a novel airlift loop reactor

Applied Biochemistry and Biotechnology - Two different strains of baker’s yeast are cultivated using a fed-batch process with a novel airlift loop reactor. The reactor can be operated not...