Designing a Production Line to Maximize Profit

The relationship between profitability and efficiency in a production line is discussed at length for the continuous production model. We prove that a solution which maximizes efficiency will not necessarily maximize profit. Several useful relationships between profitability and efficiency are developed which can greatly enhance computational efficiency. A solution procedure is developed which will determine the optimal number of work stations by maximizing an assumed profit function. An example is provided to illustrate these relationships and the entire solution procedure.     

Glucuronidation of N-hydroxy heterocyclic amines by human and rat liver microsomes

The food-borne carcinogenic and mutagenic heterocyclic aromatic amines undergo bioactivation to the corresponding N-hydroxy (OH)-arylamines and the subsequent N-glucuronidation of these metabolites is regarded as an important detoxification reaction. In this study, the rates of glucuronidation for the N-OH derivatives of 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) by liver microsomal glucuronosyltransferase were compared to that of the proximate human urinary bladder carcinogen, N-OH-aminobiphenyl (N-OH-ABP) and the proximate rat colon carcinogen N-OH-3,2'-dimethyl-4-amino-biphenyl (N-OH-DMABP). Human liver microsomes catalyzed the uridine 5'-diphosphoglucuronic acid (UDPGA)-dependent glucuroidation of N-OH-IQ, N-OH-PhIP, N-OH-Glu-P-1 and N-OH-MeIQx at rates of 59%, 42%, 35% and 27%, respectively, of that measured for N-OH-ABP (11.5 nmol/min/mg). Rat liver microsomes also catalyzed the UDPGA-dependent glucuronidation of N-OH-PhIP, N-OH-Glu-P-1 and N-OH-IQ at rates of 30%, 20% and 10%, respectively of that measured for N-OH-DMABP (11.2 nmol/min/mg); activity towards N-OH-MeIQx was not detected. Two glucuronide(s) of N-OH-PhIP, designated I and II, were separated by HPLC. Conjugate II was found to be chromatographically and spectrally identical with a previously reported major biliary metabolite of PhIP in the rat, while conjugate I was identical with a major urinary metabolite of PhIP in the dog. Hepatic microsomes from rat, dog and human were found to catalyze the formation of both conjugates. The rat preferentially formed conjugate II (I to II ratio of 1:15), while the dog and human formed higher relative amounts of conjugate I (I to II ratio of 2.5:1.0 and 1.3:1.0 respectively). Fast atom bombardment mass spectrometry of conjugates I and II gave the corresponding molecular ions and showed nearly identical primary spectra. However, collision-induced spectra were distinct and were consistent with the identity of conjugates I and II as structural isomers. Moreover, the UV spectrum of conjugate I exhibited a lambda max at 317 nm and was essentially identical to that of N-OH-PhIP, while conjugate II was markedly different with a lambda max of 331 nm. Both conjugates were stable in 0.1 N HCl and were resistant to hydrolysis by rat, dog and human liver microsomal beta-glucuronidases.(ABSTRACT TRUNCATED AT 400 WORDS)     

Component commonality effects on inventory costs

In this paper we study the effects of increasing component commonality for a single-period model. A two-product, two-level configuration under a general component cost structure is considered. The economic implications of replacing different products' components by common components are analyzed. We develop optimal solutions for the Commonality and Non-Commonality (Basic) Models and provide bounds on the total savings resulting from using commonality. We demonstrate, under general and specific component cost structures, that some forms of commonality may not always be a preferred strategy. Furthermore, we present conditions under which commonality should not be used. Finally, an extension to the two-product multicomponent model is provided.     

Pickup (critical) velocity of particles

This work presents experimental results on pickup velocity (critical velocity) measurements for a variety of particulate solids. The present experiments together with previously published experiments of a number of researchers encompass about 100 measurements of 24 materials for a wide range of particle sizes, shapes and densities. Based on the experimental results, three zones are defined by establishing simple relationships between the Reynolds and Archimedes numbers. The empirical relationships were further modified by taking into account the pipe diameter and particle shape (sphericity). The three-zone model was shown to reasonably correlate to Geldart's classification groups.     

Inhomogeneous State of the Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> Doped with Manganese

Basing on electron spin resonance (ESR) data for Bi₂Te₃ doped by Mn ions we argue that this compound can be inhomogeneous and consists of two components with the different structures. Its main phase Bi _2?x Mn _x Te ₃ is intertwined with the microscopical inclusions of MnBi phase. The integral volume of these intermetal clusters is less than 1 % but nevertheless they exert the serious impact on the dynamic magnetic properties of the entire system. These inclusions are ferromagnetic with the Curie temperature of 630 K, while the main bulk phase Bi _2?x Mn _x Te ₃ has x= 0.05 orders at T _c= 10 K (qualitatively this twophase picture is valid not only for this given x). Below this temperature two ferromagnetic phases coexist. Since the integral spontaneous polarization in MnBi phase is averaged out due to its random orientations in different clusters the time-reversal symmetry of Bi ₂Te ₃ doped by Mn ions is violated only at the low-temperature ferromagnetic transition.     

Practical voting rules with partial information

Voting is an essential mechanism that allows multiple agents to reach a joint decision. The joint decision, representing a function over the preferences of all agents, is the winner among all possible (candidate) decisions. To compute the winning candidate, previous work has typically assumed that voters send their complete set of preferences for computation, and in fact this has been shown to be required in the worst case. However, in practice, it may be infeasible for all agents to send a complete set of preferences due to communication limitations and willingness to keep as much information private as possible. The goal of this paper is to empirically evaluate algorithms to reduce communication on various sets of experiments. Accordingly, we propose an iterative algorithm that allows the agents to send only part of their preferences, incrementally. Experiments with simulated and real-world data show that this algorithm results in an average of 35% savings in communications, while guaranteeing that the actual winning candidate is revealed. A second algorithm applies a greedy heuristic to save up to 90% of communications. While this heuristic algorithm cannot guarantee that a true winning candidate is found, we show that in practice, close approximations are obtained.