Stochastic inventory system with lead time flexibility: offered by a manufacturer/transporter

This paper studies lead time flexibility in a two-stage continuous review supply chain in which the retailer uses the (R, Q) inventory system: when his inventory position reaches R, the retailer places orders with size Q to the manufacturer, who uses a transportation provider to deliver them with different lead time options. According to the contract, the manufacturer is able to expedite or postpone the delivery if the retailer makes such a request. Hence, the retailer has the flexibility to modify the lead time by using the most up-to-date demand information. The optimal lead time policy is found to be a threshold-type policy. The sensitivity analysis also shows that R is much more sensitive to the change of lead time than Q, and thus, the paper is primarily focused on finding optimal R. We also provide a cost approximation which yields unimodal cost in R. Furthermore, we analyze the order crossing problem and derive an upper bound for the probability of order crossing. Finally, we conduct an extensive sensitivity analysis to illustrate the effects of lead time flexibility on supply chain performance and discuss the managerial insights.     

A probabilistic evolution approach trilogy, part 3: temporal variation of state variable expectation values from Liouville equation perspective

This is the third and therefore the final part of a trilogy on probabilistic evolution approach. The work presented here focuses on the probabilistic evolution determination for the state variables of a many particle system from classical mechanical point of view. Probabilistic evolution involves the expected value evolutions for all natural number Kronecker powers of the state variables, positions and momenta. We use the phase space distribution of the Liouville equation perspective to construct the expected values of the state variables’ Kronecker powers to define unknown temporal functions. The infinite number homogeneous linear ODEs with an infinite constant coefficient matrix are constructed by following the same steps as in the previous two works on quantum mechanics. The only difference is in the definitions of the expected values here. We also focus on a system of many harmonic oscillators to illustrate the block triangularity.     

Constancy maximization based weight optimization in high dimensional model representation for multivariate functions

High Dimensional Model Representation (HDMR) method is a technique that represents a multivariate function in terms of less-variate functions. Even though the method has a finite expansion, to determine the components of this expansion is very expensive due to integration based natures of the components. Hence, the HDMR expansion is generally truncated at certain multivariance level and such approximations are produced to represent the given multivariate function approximately. The weight function selection becomes an important issue for the HDMR based applications when it is desired to give different importances to function values at different points. An appropriately chosen weight function may increase the quality of the approximation incredibly. This work aims at a multivariate weight function optimization to obtain high quality approximations through the HDMR method to represent multivariate functions. The proposed optimization considers constancy measurer maximization which produces a quadratic vector equation to be solved. Another contribution of this work is to use a recently developed method, fluctuation free integration, with HDMR, to solve this equation easily. This work is an extension of a previous work about weight optimization in HDMR for univariate functions.     

A fluctuation removal based univariate integration over prescribed nodes: certain important aspects of one node fluctuation free integration

This work aims at the evaluation of a univariate integral whose integrand except the weight function is assumed to be analytic inside a region containing the integration interval as an interior line in the complex plane of the independent variable. The method developed here is based on the idea of fluctuation removal which is the basic root of fluctuation free integration and Gauss quadratures. To this end, first, weight function generating subspaces are constructed. Then various possibilities to use a true weight function in the integration are discussed. All analyses here are for one node integration although higher order fluctuation removal possibilities are also restrictedly discussed. Certain illustrative applications are also distributed in side the sections to support the ideas of the work.     

A novel class of compounds: synthesis of 5,5′-carbonyl-bis(5,6-dihydro-4H-furo- and thieno-[2,3-c]pyrrol-4-ones)

We hereby report the first synthesis of novel class of compounds, 5,5′-carbonyl-bis(5,6-dihydro-4H-thieno- and furo-[2,3-c]pyrrol-4-one starting from methyl 2-(2-methoxy-2-oxoethyl) thiophene- and furan-3-carboxylate, respectively. The ester functionalities connected to methylene group were regiospecifically converted to the desired monoacyl azides. Curtius rearrangement of acyl azides followed by hydrolysis of the formed isocyanates gave the symmetrical urea derivatives. Cyclization of the ester groups provided the target compounds.     

Stress analysis of functionally graded rotating discs: analytical and numerical solutions

This study deals with stress analysis of annular rotating discs made of functionally graded materials(FGMs).Elasticity modulus and density of the discs are assumed to vary radially according to a power law function,but the material is of constant Poisson’s ratio.A gradient parameter n is chosen between 0 and 1.0.When n = 0,the disc becomes a homogeneous isotropic material.Tangential and radial stress distributions and displacements on the disc are investigated for various gradient parameters n by means of the diverse elasticity modulus and density by using analytical and numerical solutions.Finally,a homogenous tangential stress distribution and the lowest radial stresses along the radius of a rotating disc are approximately obtained for the gradient parameter n = 1.0 compared with the homogeneous,isotropic case n = 0.This means that a disc made of FGMs has the capability of higher angular rotations compared with the homogeneous isotropic disc.     

Synthesis and characterization of poly{2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole} and its copolymer with EDOT

A pyrrole-functionalized monomer 2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole (PyPhPy) was synthesized. The structure of monomer was investigated by Nuclear Magnetic Resonance (¹H NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The chemical polymerization of PyPhPy (CPyPhPy) was realized using FeCl₃ as the oxidant. The electrochemical oxidative polymerization of polymer P(PyPhPy) and its copolymer with 3,4-ethylenedioxythiophene poly(2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole-co-3,4-ethylenedioxythiophene) [P(PyPhPy-co-EDOT)] were achieved via potentiodynamic method by using NaClO₄/LiClO₄ as the supporting electrolyte in CH₃CN. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), UV-Visible spectrophotometry (UV-Vis) and thermogravimetry analyses (TGA). Electrical conductivity of CPyPhPy, P(PyPhPy), and P(PyPhPyco-EDOT) were measured by four-probe technique.     

DFT, FT-Raman and FT-IR investigations of 5-o-tolyl-2-pentene

FT-IR and Raman spectra of 5-o-tolyl-2-pentene (OTP) have been experimentally reported in the region of 4000-10 cm(-1) and 4000-100 cm(-1), respectively. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of cis and trans isomers of OTP (C12H16) have been theoretically examined by means of B3LYP hybrid density functional theory (DFT) method together with 6-31G(d) and 6-31++G(d,p) basis sets. Furthermore, reliable vibrational assignments have made on the basis of potential energy distribution (PED) calculated. Comparison between the experimental and theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for predicting vibrational wavenumbers and trans isomer is supposed to be the most stable form of OTP molecule.     

Synthesis and In-Vitro Antimicrobial Activity of Novel Aminophosphinic Acids Containing Cyclobutane and 1,3-Thiazole

Abstract

The compounds {[4-(3-methyl-3-aryl(mesityl-phenyl-tetralino)cyclobutyl)-1,3-thiazol-2-yl]amino}(aryl)methyl-phosphinic acids 2a–l were prepared by condensation of 2-amino-4-(3-aryl(mesityl-phenyl-tetralino)-3-methylcyclobutyl) thiazoles 1a–c with various aromatic aldehydes and hypophosphorous acid through a one-pot reaction. The characterizations of these compounds were obtained by elemental analyses, infrared (IR) spectra, and ¹H, ¹³C, and ³¹P NMR (nuclear magnetic resonance) techniques. The synthesized compounds were tested in vitro against one Gram-positive and two Gram-negative bacterial strains, one mycobacterial strain, and a fungus Candida albicans. Compound 2f showed significant activity against Staphylococcus aureus, whereas the others had no remarkable activity on this strain. Compound 2g was found to be more active than the others against Mycobacterium fortuitum at an MIC (minimum inhibitory concentration) value of 32 μg/mL. The antibacterial and antifungal activities of 2a–l were also compared with various standard drugs.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Biological Activities. Table S1. Figures S1–S6.]

GRAPHICAL ABSTRACT