Critical Flow Method: A New Reliability Allocation Approach for a Thermonuclear System

In the present work, starting from well‐known methodologies, a new reliability allocation method [critical flow method (CFM)] has been proposed. We focused on the most important conventional methods and discussed their limitations in order to motivate the current research. The results show the main common problem of the most conventional reliability allocation methods: they are developed for complex systems with series configurations but not for series–parallel ones. The consequence is an increase of the required units' reliability (series configuration) in order to guarantee the reliability system target. Actually, the design and manufacturing of a subsystem with an extremely low failure rate would consume a considerable amount of economic resources. The proposed method can solve the shortcomings of the conventional methods with a new reliability approach useful to series–parallel configurations in order to obtain an important cost saving. The CFM has been applied to a liquid nitrogen cooling installation in a thermonuclear system, with many series–parallel configurations in order to guarantee the whole safety system. The proposed technique can be applied to working complex systems, and, in general, in the design phase of new installations. By comparing the CFM application results with real parameters, the new technique has been validated. The computational results clearly demonstrate the advantages of the proposed method. In particular, by applying the method to series–parallel configurations, it allocates failure rates higher than conventional methods, with a component cost reduction. Copyright © 2015 John Wiley & Sons, Ltd.     

A model and software architecture for MMORPG traffic generation based on player behavior

In this paper we present a software architecture for traffic generation based on application level player behavior in Massively Multiplayer Online Role-Playing Games (MMORPGs). We have performed measurements of network traffic for each of the previously defined action categories for MMORPGs (Trading, Questing, Dungeons, Raiding, Player versus Player Combat, and Uncategorized), as well as measurements of application level player behavior in terms of listed action categories. Based on the obtained datasets we have created network traffic models for each action category and player behavior models with focus on hourly and daily trends. Network traffic models are implemented in Distributed Internet Traffic Generator and verified through comparison with the real traffic. Player behavior models explore number of active players, session duration, as well as lengths and probability of session segments (i.e., parts of the session consisting of only one category of player actions). We propose an architecture which enables scalable, behavior-driven traffic generation and implement it in a laboratory testbed. In order to achieve scalability of the system, we use Linux Containers as a virtualization technique. The resulting implementation can generate hundreds of MMORPG streams on a single PC. As a case study we used Activision Blizzard’s World of Warcraft.     

Existence of states on quantum structures

Orthomodular lattices occurred as generalized event structures in the models of probability for quantum mechanics. Here we contribute to the question of existence of states (=probability measures) on orthomodular lattices. We prove that known techniques do not allow to find examples with less than 19 blocks (=maximal Boolean subalgebras). This bound is achieved by the example by Mayet [R. Mayet, Personal communication, 1993]. Although we do not finally exclude the existence of other techniques breaking this bound, existence of smaller examples is highly unexpected.     

Testing-based translation validation of generated code in the context of IEC 61508

Production code generation with Model-Based Design has successfully replaced manual coding across various industries and application domains. Furthermore, code generated from executable graphical models is increasingly being deployed in high-integrity embedded applications. To validate the model-to-code translation process, generated software components and its precursory stages (i.e. models) should be subjected to an appropriate combination of quality assurance measures. For high-integrity applications, compliance with safety standards such as IEC 61508 needs to be demonstrated as well.     

Toward enhanced hydrogen production in a catalytic naphtha reforming process

Environmental regulations imposed on transport fuels, especially specifications on sulfur and nitrogen content, generally boost hydrogen requirements in refining industries. The catalytic naphtha reformer (CNR) process is one of the major sources of hydrogen in naphtha refinery, thus improving its hydrogen production would be of great importance for refining industries. Close examination of the reaction kinetics of CNR processes has identified temperature, hydrogen concentration and catalyst activity as key variables affecting the process's performance. In this paper, a new reactor concept is developed that better exploits these process variables. The proposed membrane moving-bed reactor promises to significantly outperform the conventional continuous catalyst regenerative (CCR) design. A case study identifies improvements of 23.6 mol% in hydrogen production, 18.8 mol% in aromatics production. Moreover, the reformate yield was found to increase by 10.6 wt%, while the production of light gases decreases to a value of 18.6 wt%.     

Unsteady‐ and steady‐state gas permeation through active packaging walls

Steady‐ and unsteady‐state gas permeation rates through packaging walls containing active (scavenger) materials are determined as functions of the system's physical parameters and the scavenger load. With the simplifying assumptions of constant scavenger concentration and first‐order reaction kinetics, steady‐state analysis shows that there is a minimum quantity of scavenger that must be added to the packaging wall if any reduction of gas permeation is to be achieved. Unsteady‐state studies have established the dependence of the time needed to reach stationary behaviour on the system's physical parameters. Copyright © 2007 John Wiley & Sons, Ltd.     

Economic feasibility assessment of rice straw utilization for electricity generating through combustion in Thailand

The economic feasibility of biomass based combustion projects of various capacities to generate electricity from rice straw is evaluated for Thailand. For an assumed lifespan of 20 years, rice straw-fueled combustion facilities would generate Net Present Values (NPV) of −3.15, 0.94, 2.96, 9.33, and 18.79 million USD for projected 5, 8, 10, 15, and 20 MW_e plants, respectively. Examining the effects of scale on the cost of generated electricity (COE) over the considered range of capacities indicates that COE varies from 0.0676 USD/kWh at 20 MW_e to 0.0899 USD/kWh at 5 MW_e. By scaling up the power plants, the variations of the financial parameters, namely NPV values, become less sensitive to the critical variables. As an example, if the fuel price, selling price of electricity, and the plant factor change by +36% (31.0 USD/t), −16% (0.0758 USD/kWh), and −14% (5650 h/yr), respectively, the largest scale project is still appealing for investment. Nevertheless, to ensure a secure fuel supply, smaller scale power plants, i.e., 8 and 10 MW_e may be more practicable. A further sensitivity analysis is discussed in terms of the financial feasibility of the projects (i.e., NPV ? 0), and the investment appraisal condition (here, Internal Rate of Return or IRR ? 11%).     

Treatment with Edoxaban Attenuates Acute Stroke Severity in Mice by Reducing Blood–Brain Barrier Damage and Inflammation

Patients with atrial fibrillation and previous ischemic stroke (IS) are at increased risk of cerebrovascular events despite anticoagulation. In these patients, treatment with non-vitamin K oral anticoagulants (NOAC) such as edoxaban reduced the probability and severity of further IS without increasing the risk of major bleeding. However, the detailed protective mechanism of edoxaban has not yet been investigated in a model of ischemia/reperfusion injury. Therefore, in the current study we aimed to assess in a clinically relevant setting whether treatment with edoxaban attenuates stroke severity, and whether edoxaban has an impact on the local cerebral inflammatory response and blood–brain barrier (BBB) function after experimental IS in mice. Focal cerebral ischemia was induced by transient middle cerebral artery occlusion in male mice receiving edoxaban, phenprocoumon or vehicle. Infarct volumes, functional outcome and the occurrence of intracerebral hemorrhage were assessed. BBB damage and the extent of local inflammatory response were determined. Treatment with edoxaban significantly reduced infarct volumes and improved neurological outcome and BBB function on day 1 and attenuated brain tissue inflammation. In summary, our study provides evidence that edoxaban might exert its protective effect in human IS by modulating different key steps of IS pathophysiology, but further studies are warranted.     

Studies on the biological effects of ozone: 6. Production of transforming growth factor 1 by human blood after ozone treatment

After exposing human whole blood from normal volunteers to ozone concentrations ranging from 22 to 156 micrograms/ml, we have shown that, upon incubation of up to 8 hours, there is a significant release of transforming growth factor beta (TGF-beta 1). In comparison to TGF-beta 1, TGF-beta 2 production is not influenced by ozone concentrations. In line with our previous findings it appears that blood, in the presence of heparin and 5mM Ca,2+ allows a consistent production of tumor necrosis factor a (TNF alpha) and the release of low and non-hazardous levels of free hemoglobin. These data support the contention that autohemotherapy performed after treating blood with ozone followed by reinfusion into the donor, may represent a valuable therapeutic approach for achieving immunoregulatory effects.