How to give the gift of hospitality. Great customer service

Whether it takes the form of greeting customers with a smile, redressing a diner's grievance or conducting special kitchen tours, providing customer service has become the number-one priority in foodservices coast to coast. Operators share tips & training methods that are helping staffs provide the hospitable services today's customers are demanding.     

Concurrent reachability games

We consider concurrent two-player games with reachability objectives. In such games, at each round, player 1 and player 2 independently and simultaneously choose moves, and the two choices determine the next state of the game. The objective of player 1 is to reach a set of target states; the objective of player 2 is to prevent this. These are zero-sum games, and the reachability objective is one of the most basic objectives: determining the set of states from which player 1 can win the game is a fundamental problem in control theory and system verification. There are three types of winning states, according to the degree of certainty with which player 1 can reach the target. From type-1 states, player 1 has a deterministic strategy to always reach the target. From type-2 states, player 1 has a randomized strategy to reach the target with probability 1. From type-3 states, player 1 has for every real ε>0$\epsilon >0$ a randomized strategy to reach the target with probability greater than 1−ε$1-\epsilon$. We show that for finite state spaces, all three sets of winning states can be computed in polynomial time: type-1 states in linear time, and type-2 and type-3 states in quadratic time. The algorithms to compute the three sets of winning states also enable the construction of the winning and spoiling strategies.     

Surfactants for producing low interfacial tensions: II. Linear alkylbenzenesulfonates with additional alkyl substituents

The synthesis and low interfacial tension behavior of a variety of di- and trialkylbenzenesulfonates are described. The benzene ring carries one major alkyl substituent, consisting of a linear chain eight to sixteen carbon atoms long, and one or two additional methyl, ethyl, propyl, i-propyl, butyl, or t-butyl groups. The addition of these extra groups causes the low interfacial tensions to shift to higher molecular weight alkanes when compared to the parent linear alkylbenzenesulfonate. Surfactants in these structural classes can give very low interfacial tensions against those alkanes which best model the behavior of crude oils, but this is influenced by the number and type of the short alkyl substituents. These surfactant structures are more attractive from the point of view of tertiary oil recovery than linear alkylbenzenesulfonates.     

A reduced adsorption isotherm for surfactant mixtures

The adsorption of surfactants of similar structure on mineral oxide surfaces can be described by a single adsorption isotherm when plotted against reduced concentration. The total adsorption of mixtures of these surfactants and the adsorption of each individual surfactant in the mixture can be estimated from this reduced adsorption isotherm. No mixture data are required for this calculation. The method of calculating the reduced concentration for pure surfactants and surfactant mixtures is discussed. Adsorption data of three isomerically pure alkylbenzene sulfonates and binary mixtures of these surfactants on alumina and kaolinite is used to illustrate this correlation.     

Hydroxyapatite/Mesoporous Graphene/Single‐Walled Carbon Nanotubes Freestanding Flexible Hybrid Membranes for Regenerative Medicine

Freestanding flexible membranes based on biocompatible calcium phosphates are of great interest in regenerative medicine. Here, the authors report the first synthesis of well‐aligned biomimetic hexagonal bars of hydroxyapatite (HAp) on flexible, freestanding mesoporous graphene/single‐walled carbon nanotubes (MG/SWCNT) hybrid membranes. The chemical composition and surface morphology of the HAp coating resemble those of biological apatite. Nitrogen doping and oxygen plasma etching of the MG/SWCNT membranes increase the density of nucleation sites and yield more uniform coatings. This novel membrane favors the attachment and proliferation of human fetal osteoblast (hFOB) osteoprogenitor cells. When soaked in simulated body fluid, enhanced in vitro biomineralization occurs on the hybrid membranes. This hybrid membrane holds great promise in biomedical applications such as patches and strips for spine fusion, bone repair, and restoration of tooth enamel.     

Production of active recombinant human chymase from a construct containing the enterokinase cleavage site of trypsinogen in place of the native propeptide sequence

Human chymase, a chymotrypsin-like proteinase found in mast cells, was produced in an enzymatically active recombinant form. The protein was expressed in Escherichia coli as part of an insoluble fusion protein which was solubilized and renatured. The structure of the fusion protein was NH2-ubiquitin-enterokinase cleavage site-chymase-COOH. The enterokinase cleavage site of trypsinogen replaced the native propeptide sequence of chymase, allowing for activation by a readily available proteinase (enterokinase) of known specificity. Characterization of refolded-activated recombinant chymase with substrates and inhibitors demonstrated properties identical to that of the native proteinase isolated from skin.     

Fairness and hyperfairness in multi-party interactions

Summary In this paper, a new fairness notion is proposed for languages withmulti-party interactions as the sole interprocess synchronization and communication primitive. The main advantage of this fairness notion is the elimination of starvation occurring solely due to race conditions (i.e., ordering of independent actions). Also, this is the first fairness notion for such languages which is fully adequate with respect to the criteria presented in [2]. The paper defines the notion, proves its properties, and presents examples of its usefulness. Orna Grumberg received her B.Sc. degree, M.Sc. and Ph.D. in the Computer Science Department at the Technion—Israel Institute of Technology. Since 1984 she is a faculty member in the Computer Science Department at the Technion. Her research interests include verification of distributed systems, computer-aided verification, model checking, temporal logics and automata. Paul Attie received a B.A. degree in engineering science from the University of Oxford, and an M.Sc. degree in computer science from the University of London. Since 1986, Paul has been with the Microelectronics and Computer Technology Corporation, where he is currently a member of technical staff. He is also a candidate for the Ph.D. in computer science degree at the University of Texas at Austin. His research interests include temporal logic, fairness, algebraic process theory, formal semantics, and concurrent program verification.The photograph and autobiography of Dr. Nissim Francez were published in Volume 2, Issue No. 4, 1988 on page 226     

Process analysis of a reactor-separator system: Enzymic degradation of polymeric substrates

The analysis deals with an integrated system in which enzymic de-polymerization of a macromolecular substrate and concomitant separation of the reaction products take place. The enzyme is immobilized within a packed-bed reactor and products are separated by ultrafiltration. A compartmental model was set up and used to simulate the performance of the system in terms of yield, purity, and productivity of the monomer obtained, and as a function of the system operating mode (batch or continuous), recirculation ratio, enzyme mode of action (preferred attack or exo-type), and initial polymer concentration. Results, calculated using the analytical model, are in good agreement with our experimental findings concerning the depolymerization of inulin by exo-inulinase. Future applications include engineering design of the system and optimization of its operational parameters.