Modeling of continuous self‐classifying spiral jet mills part 1: Model structure and validation using mill experiments

The objective of this work is to develop a milling model for a continuous self‐classifying spiral air jet mill. Its foundation is a population balance model with selection and breakage distribution functions that have been related to a minimal number of mill‐dependent and powder‐dependent parameters. Initially, experimentation is required to determine the mill‐dependent parameters for a specific mill, by milling a “base” powder at multiple operating conditions. Powder‐dependent parameters can be determined from either mill experiments or from material characterization measurements that require small amounts of powder (presented in Part 2). Ultimately, the milling model presented successfully predicts the product particle size using as inputs the feed particle‐size distribution and mill operating conditions. Three crystalline powders, sodium bicarbonate, lactose monohydrate, and sucrose, have been used to test the proposed milling model. © 2014 American Institute of Chemical Engineers AIChE J 60: 4086–4095, 2014     

Particulate polycyclic aromatic hydrocarbons and n-alkanes in recycled paper processing operations

The aliphatic and polycyclic aromatic fractions of dust collected in the vicinity of recycled paper processing operations were analyzed using gas chromatography/mass spectrometry. Total measured dust concentration (up to 8.73+/-2.02 mg/m3) fluctuated substantially in the different steps of paper manufacture. This was attributed to the type of the operation such as, the release of fibers and particles during paper cutting and the use of reactive chemicals and excessive water under high temperature and pressure during the bleaching and the water rinsing/drying step. Particulate polycyclic aromatic hydrocarbons (PAHs) (from fluorene to benzo[ghi]perylene with mean concentrations from 3.8+/-0.5 to 41.4+/-0.4 ng/m3) and the unresolved mixture of branched, cyclic and unsaturated hydrocarbons (UCM) were measured in all samples while, n-alkanes from n-C20 to n-C27, were only observed in cutting and packaging areas (from 180.6+/-18.9 to 4297.9+/-794.9 ng/m3). The profile of occupational PAHs in bleaching and treatment of contaminated recycled raw paper was comparable to that observed for anthropogenic activities. The values of molecular diagnostic ratios indicated the contribution of oil residues and emissions from worklifts and other equipment used for pulp and paper handling. Total benzo[a]pyrene-equivalent (BaP) concentrations of particulate PAHs (varied from 323 up to 1104 pg/m3), provided evidence that workers were exposed to high quantities of PAHs as compared with exposures to urban air and other indoor settings, posing long-term threat to their health.     

Applying Total Quality Management in an Interdisciplinary Engineering Course

A Process Engineering certificate program has been developed and conducted utilizing the talents of members from five different engineering departments. Now in its third year, the success of this 12-credit “megacourse” is due in large part to the use of Total Quality Management (TQM) principles and methods in the development and teaching of the course. Students benefit by learning TQM, by seeing it applied, and from an overall improved course.     

Modeling Robot “Psycho-Physical” State and Reactions – A New Option in Human–Robot Communication Part 1: Concept and Background

Man–machine communication had been recognized a long time ago as a significant issue in the implementation of automation. It influences the machine effectiveness through direct costs for operator training and through more or less comfortable working conditions. The solution for the increased effectiveness might be found in user-friendly human–machine interface. In robotics, the question of communication and its user-friendliness is becoming even more significant. It is no longer satisfactory that a communication can be called human–machine interface, since one must see robots as future collaborators, service workers, and probably personal helpers. So, a new way of communication is needed. This paper starts from the fact that a variety of unconventional ways of communication is being explored: speech communication, handwriting, and facial mimicry. Speech recognition and generation, apart from its potentially strong impact to human–robot interface, is out of the scope of this study, and the same holds for handwriting. The facial mimicry and the wider field of robot emotion lead to a new way of communication that can be called gestural language. We may say that our research matches such a wide notion. However, there is an important specificity of our approach. Previous works in this field looked at facial and gestural expressions of emotions and messages as actually voluntary activities. They were induced by some situations, but such situations had to be recognized after which the appropriate preprogrammed reaction followed. Thus, some expert system or other artificial intelligence system were applied. The current study explores the conditional reactions that are chemically based. Human psycho-physical states like fear, stress and especially fatigue follow from complex chemical processes. Such states cannot be voluntarily controlled. They are not expressed through some specific mimicry or body movement, but they influence all movements. Any motion intended to accomplish some task will be changed, thus sending a message to the neighborhood. This change can be observed, and so the message is received. For processes of this kind and their resembling, we prefer using the term modeling psycho-physical states. Among various states interesting for application in robots, the present study concentrates on fatigue, which is a good example for the initial research. The first part of the paper explains the concept and the background, while the second part provides numerical justification.     

Development of sodium propionate-based deep eutectic solvents for polyphenol extraction from onion solid wastes

Clean Technologies and Environmental Policy - The objective of the study presented herein was the optimisation of onion solid waste (OSW) polyphenol extraction, using sodium propionate-based deep...     

The structure and complexity of Nash equilibria for a selfish routing game

In this work, we study the combinatorial structure and the computational complexity of Nash equilibria for a certain game that models selfish routing over a network consisting of m$m$ parallel links. We assume a collection of n$n$ users, each employing a mixed strategy, which is a probability distribution over links, to control the routing of her own traffic. In a Nash equilibrium, each user selfishly routes her traffic on those links that minimize her expected latency cost, given the network congestion caused by the other users. The social cost of a Nash equilibrium is the expectation, over all random choices of the users, of the maximum, over all links, latency through a link.     

Design, Implementation and Validation of an Open Source IP-PBX/VoIP Gateway Multi-Core SoC

The telephony world is consistently moving to the transmission of voice through packet networks, so as to unify data and voice and to enable the provisioning of new services in a less costly manner. Service providers are offloading the task of converting analog voice to VoIP to the end-points. In this paper we present an IP-PBX/VoIP Gateway system based on a single, multi-core SoC that performs all the required processing. The system targets the low density market of home gateways and SME IP-PBXs, where cost is the main factor. We prove it is feasible to implement a 4-channel IP-PBX/VoIP gateway on a SoC based purely on both software and hardware provided by the open-source community, reducing both upfront and final product costs thus allowing new players into the market. The highly configurable design allows the integration of multiple embedded cores in the same die increasing channel density while reducing clock cycles per channel. The idea of using one or more open-source embedded cores can be extended to many different applications requiring moderate DSP performance, resulting in a “DSP-free”, low-cost system, with minimal design effort.     

VIPSec defined

Secure end-to-end information exchange is a constant challenge in electronic communications. Novel security architectures and approaches are proposed constantly, to be followed by announcements of sophisticated attack methods that compromise them, while other more sophisticated attack methods never see the daylight.The traditional approach for securing the communication between two peers is through the use of secret key encryption combined with a public key approach for exchanging the common secret key to be used by the end-peers. The public key part of the communication is based on a trusted authority for providing the public keys, a service provided through a public key infrastructure (PKI). Public key infrastructures are vulnerable to man in the middle attacks, among other approaches that compromise their integrity. A fake certification authority (CA) or a malicious/compromised network between the user and the CA are typical weaknesses. There has been a lot of work for providing robust PKI; the proposed solutions are fairly demanding on network resources, hence public key solutions are not the security approach of choice in several applications that require light weight solutions.In this article we present voice interactive personalized Security (VIPSec) protocol, which is a protocol for media path key exchange to securely establish a session symmetric key for ensuring end-to-end secure communication, where it is possible to have biometric based authentication, exploiting the nature of the application; voice communication is the typical example that we use as our paradigm for describing the method.