Flavouring of imitation cheese with enzyme-modified cheeses (EMCs): Sensory impact and measurement of aroma active short chain fatty acids (SCFAs)

Enzyme-modified cheeses (EMCs) are used to impart flavour to imitation cheese products. Cheeses (pH 6 or 5.5) were formulated with 5% w/w EMC, having low, medium or high levels of lipolysis and were examined by a sensory panel. Free fatty acid analyses were performed using SPME/GC. The flavour profile of the flavoured cheeses was affected by EMC composition and pH of the cheese base. Cheeses at a pH of 6.0, flavoured with low lipolysis EMCs, were described as ‘bland’. Lowering the pH of the cheese matrix to 5.5 appeared to increase the flavour intensity of the cheese flavoured with low lipolysis EMC and panellists ranked this cheese the highest, describing its flavour as ‘well-balanced and ‘cheesy’. This study shows that the flavours of imitation cheeses are influenced by the level of lipolysis of the EMCs used to flavour them and also by the pH of the cheese base.     

New Stainless Steel Solutions as Economic Alternatives to Classical 1.4301 Austenitic Grades

In the recent situation of a historically high nickel price, austenitic stainless steels, such as 1.4301, became too expensive compared to their actual technical value in many applications. This paper presents two new stainless steel grades developed by ArcelorMittal to replace 1.4301. The first one is a 20%Cr ferritic grade. The second one is a low‐Ni Cu‐bearing austenitic grade. The choices in the compositions are described as a function of the technical requirements, economical target and the production process limitations. The final properties are discussed as a function of the composition and compared with 1.4301 and other existing stainless steels. Finally, the complementarities of these two new grades are highlighted in regard to the different application markets considered.     

Hard combinators

Hard Interaction systems can be presented as graph relabeling with a handshake mechanism that provide local synchronization. We present a particular one with only four symbols and seven rules that can be used to simulate all the other hard interaction systems.     

Al-Cr-O thin films as an efficient hydrogen barrier

Thin Al-Cr-O films are proposed as hydrogen permeation barriers. Layers of a few microns in thickness are able to suppress hydrogen permeability by a factor of 2000 to 3500 at temperatures of 700 °C, as has been found in our gas phase permeation experiments. We attribute this excellent efficiency to a dense layer morphology and the possible (pre)-formation of solid solutions in corundum-type structure. These films are deposited by pulsed arc evaporation in a batch-type production system at substrate temperatures of 550 °C.     

Signal probability for reliability evaluation of logic circuits

As integrated circuits scale down into nanometer dimensions, a great reduction on the reliability of combinational blocks is expected. This way, the susceptibility of circuits to intermittent and transient faults is becoming a key parameter in the evaluation of logic circuits, and fast and accurate ways of reliability analysis must be developed. This paper presents a reliability analysis methodology based on signal probability, which is of straightforward application and can be easily integrated in the design flow. The proposed methodology computes circuit’s signal reliability as a function of its logical masking capabilities, concerning multiple simultaneous faults occurrence.     

Fault diagnosis as an aid to process machine reliability

Identification of the reasons for failures of process plant machines is the first step in obtaining increased reliability. Weibull analysis of the service life obtained from maintenance records requires a minimum of only five incidents and provides an insight into the failure mechanism. Two examples are given where Weibull analysis of maintenance records helped identify the cause of failure and was instrumental in achieving enhanced reliability of process plant machines.     

Coordination mechanisms for decentralized parallel systems

On resource sharing platforms, the execution of the jobs submitted by users is usually controlled by a centralized global scheduler. It determines efficient schedules regarding some common objective function that all organizations agree with (for instance, maximizing the utilization of the entire platform). However, in practice, each organization is mostly interested in the performance obtained for its own jobs. We study the price that the collectivity must pay in order to allow independence to selfish, self‐governing organizations, so they can choose the best schedules for their own jobs. In other words, we are interested in analyzing the costs on the global performance inflicted by the decentralization of scheduling policies. We present a game‐theoretic model for the problem and the associated coordination mechanisms developed to reduce the cost of the decentralization of the decision‐making process. The main contribution is to show (in theory and practice) how to devise pure Nash equilibria configurations for every instance of the problem and to prove that the price paid by the collectivity depends on the local scheduling policy and on the characteristics of the workload executed on such platforms. Copyright © 2014 John Wiley & Sons, Ltd.     

Hydrolytic stability of toluene diisocyanate and polymeric methylenediphenyl diisocyanate based polyureas under environmental conditions

Polyureas were prepared by reacting toluene diisocyanate (TDI) or polymeric methylenediphenyl diisocyanate (PMDI) with water under prolonged vigorous mixing at room temperature. Hydrolytic degradation of these (powdered) TDI- and PMDI-based polyureas was studied by measuring the rates of formation of free toluenediamine (TDA) or methylenedianiline (MDA) in water as a function of time by utilizing HPLC. The heterogeneous hydrolysis reactions were carried out in glass reaction tubes under nitrogen with initial polyurea loadings of 2 g/L in deionized water or buffer solution. In the case of TDI-polyurea, concentrations of free 2,4- and 2,6-toluenediamine in water were measured after hydrolysis at 120, 140, and 160 degrees C. The hydrolysis of PMDI-polyurea was carried out at 150, 160, and 170 degrees C, and concentrations of 2,4'-methylenedianiline (2,4'-MDA), 4,4'-methylenedianiline (4,4'-MDA), and 2,4-bis(p-aminobenzyl)aniline were measured. In both cases the rate of formation of diamine was well represented by both a pseudo-first-order reaction and a zero-order reaction. The temperature dependence of rate constants fit Arrhenius behavior. The half-time for hydrolysis of TDI-polyurea at 25 degrees C was calculated to range from about 18,000 to 300,000 years and that of PMDI-polyurea was estimated to range from about 110,000 to 12 million years, depending on the kinetic assumptions made. The half-times for hydrolysis at buffered pH levels of 4, 7, and 9 were within a factor of 2 of those in deionized water. These results are of importance in understanding the fate of polyureas formed in the event of a release of TDI or PMDI into the environment.     

Simultaneous optimization of the mechanical properties of postconsumer natural fiber/plastic composites: Phase compatibilization and quality/cost ratio

In this work, a simultaneous optimization by phase compatibilization of four mechanical proprieties (flexural and tensile moduli, impact strength, and tensile stress at yield) of natural fiber/plastic composites was performed with respect to raw materials cost. In particular, a recycled resin of postconsumer origin (blend of high density polyethylene and polypropylene) with flax fibers was extruded with an additives package: a coupling agent (maleic anhydride grafted polypropylene) and an impact modifier (maleic anhydride grafted ethylene octene metallocene copolymer) to improve the interface between each phase. Then, the compounds were injection molded and tested. The analysis was performed according to a Box‐Behnken experimental design to study the effect of fiber concentration, total additives concentration, and impact modifier fraction in the additives package. The optimization process required three steps: to model the relationships between mechanical properties and selected factors by a multiple linear regression analysis, to identify the potentially optimum conditions using the desirability function approach (Derringer–Suich and Ch'ng et al.), and to determine the best composite composition (optimum condition) by a comparative analysis of the material quality/cost ratios. POLYM. COMPOS., 35:730–746, 2014. © 2013 Society of Plastics Engineers