Molecular weight distributions of tars produced by flash pyrolysis of coals

The molecular weight distributions of tars produced during flash pyrolysis of coal have been determined by a combination of gel permeation chromatography and vapour phase osmometry. Small particles (62–88 μm) of two high-volatile and one low-volatile bituminous coal, and a lignite have been pyrolysed at heating rates of ≈1000 K s^?1 at temperatures from 600 to 1300 K in a heated wire mesh apparatus. The molecular weight distributions range from ≈100 to 4000 and peak in the range from 250 to 750 in all cases. The evidence gathered on a softening bituminous coal clearly indicates a selective evaporation of light fractions of the metaplast.     

Programmatically defining the software footprint of sensor networks using the Android platform

Sensor networks are being used for an increasing number of applications ranging from environmental monitoring and precision agriculture to manufacturing and health care. By gathering data at unprecedented temporal and spatial granularity, sensor networks are revolutionizing these applications. Given the scale and complexity of these systems, they face a critical challenge in software Operations and Management, that is, installing, configuring, and updating thousands of software components in a heterogeneous sensor network. In this paper, we discuss automating and simplifying the process of defining the software environment on a sensor node running the Android platform. Android has significant share in the mobile phone market and runs on a broad range of devices including embedded platforms. This paper outlines the use of a new method for configuring embedded devices and sensor networks by drawing from techniques used for defining the software environment in data centers. We have also developed a software prototype to allow for a simple, reproducible, and flexible configuration of the Android software stack on a sensor node. Our exploratory research provides an insight into the use of modular configuration techniques in embedded devices and how they can be applied to the Android ecosystem. Copyright © 2013 John Wiley & Sons, Ltd.     

Adhesion Properties of Lightly Crosslinked Solvent-Swollen Polymer Gels

Polymer gels are crosslinked polymer networks, highly swollen with solvent. For practical gel applications adhesion to a wide range of substrates over a broad range of temperatures is desired. In this article the adhesive properties of two types of solvent-swollen elastomers were studied, utilizing a combination of tack, contact mechanics, and peel adhesion methods. The first gel was a crosslinked polybutadiene swollen with common polymer plasticizers, while the second was a commercially available silicone with high extractables content. Nominally, these solvent-swollen materials exhibit similar adhesive characteristics to nonsolvent swollen elastomers including: (1) an increase in tack adhesion energies with increasing pull-off rates and decreasing temperatures in the rubbery region, (2) qualitative correlation between the rheological loss tangent for the gel and the gel adhesion energy, (3) fibrillation and extension during adhesion testing for gels with a shear modulus value less than 10⁵ Pa in the plateau region, and (4) a decrease in the adhesion energy with increasing crosslink density. However, the presence of solvent in the elastomer can lead to solvent exclusion effects that degrade tack adhesion and must be considered for gel design in practical applications.     

A molecular dynamics study of the effects of branching characteristics of LDPE on its miscibility with HDPE

The effects of branching characteristics of low-density polyethylene (LDPE) on its melt miscibility with high-density polyethylene (HDPE) were studied using molecular simulation. In particular, molecular dynamics (MD) was applied to compute Hildebrand solubility parameters (δ) of models of HDPE and LDPE with different branch contents at five temperatures that are well above their melting temperatures. Values computed for δ agreed very well with experiment. The Flory-Huggins interaction parameters (χ) for blends of HDPE and different LDPE models were then calculated using the computed δ values. The level of branch content for LDPE above which the blends are immiscible and segregate in the melt was found to be around 30 branches/1000 long chain carbons at the chosen simulation temperatures. This value is significantly lower than that of butene-based linear low-density polyethylene (LLDPE) (40 branches/1000 carbons) in the blends with HDPE computed by one of the authors (polymer 2000; 41:8741). The major difference between LDPE and LLDPE models is that each modeled LDPE molecule has three long chains while each modeled LLDPE molecule had only one long chain. The present results together with those of the LLDPE/HDPE blends suggest that the long chain branching may have significant influence on the miscibility of polyethylene blends at elevated temperatures.     

Techniques for modelling and verifying railway interlockings

We describe a novel framework for modelling railway interlockings which has been developed in conjunction with railway engineers. The modelling language used is CSP \(||\) B. Beyond the modelling we present a variety of abstraction techniques which make the analysis of medium- to large-scale networks feasible. The paper notably introduces a covering technique that allows railway scheme plans to be decomposed into a set of smaller scheme plans. The finitisation and topological abstraction techniques are extended from previous work and are given formal foundations. All three techniques are applicable to other modelling frameworks besides CSP \(||\) B. Being able to apply abstractions and simplifications on the domain model before performing model checking is the key strength of our approach. We demonstrate the use of the framework on a real-life, medium-size scheme plan.     

Effect of surface properties of activated carbons on surfactant adsorption kinetics

This research investigates the adsorption properties of three activated carbons (AC) derived from coconut, coal, and wood origin. A linear relationship exists between the number of water molecules adsorbed onto each AC and the oxygen content determined elemental analysis and XPS. An inverse linear relationship exists between the plateau amount of dodecanoic acid anionic surfactant and the oxygen content on the surface of ACs. The surface charge on each AC’s surface had a linear relationship with the plateau amount of dodecanoic acid. A plug-flow heterogeneous surface diffusion model (PFHSDM) for a fixed-bed adsorption process was developed to describe the adsorption kinetics in a fixed-bed column. The model represents axially dispersed plug-flow, external mass transfer, adsorption equilibrium on the fluid-particle interface, and intraparticle diffusion. The larger molecular dimension of the dodecanoic acid as a more hydrophobic entity than octanoic acid led to a faster external mass transfer rate but a slower surface diffusion rate as estimated from the PFHSDM. The interaction between the organic moiety of surfactant and the AC surface chemistry such as surface oxygen content and surface charge contributes to the adsorption performance in both to the adsorption equilibrium and kinetics.     

Blessing or curse? Proteomics in granzyme research

Granzymes (gzms) are a group of serine proteases that play an important role in innate and adaptive immunity, blood coagulation, apoptosis, and inflammation, but are also connected to atherosclerosis, diabetes, cardiovascular and inflammatory lung diseases, cancer, and sepsis. Humans have five gzms (gzms A, B, H, K, and M), which differ in their substrate specificity. It is widely accepted that they are delivered from cytotoxic lymphocytes via perforin into the cytoplasm of target cells where they initiate cell death, modulate cytokine signaling, or inactivate pathogen proteins. However, more recent evidence indicates gzms also act extracellularly in noncytotoxic processes. Proteomic approaches are directed at mapping gzm cleavage specificity, identifying substrates, and unraveling the (patho-) physiological role of these proteases. These studies have refined our understanding of gzm species specificity, and collectively uncovered an enormous number of new substrates. However, with the exception of a very few human gzmB substrates supported by independent data (Bid, DNA-PK, PARP, ICAD, and procaspase 7), it is presently unclear which are physiologically relevant. This review aims to summarize and analyze the different proteomic approaches used and discuss both their convincing and controversial outcomes.     

Crown ether-metal “sandwiches” as linking mechanisms in assembled nanoparticle films

Crown ether ligands attached to monolayer-protected clusters (MPCs) were assembled as films and the linking mechanism between the crown ether–metal ion–crown ether bridges between nanoparticles was examined. Thicker films exhibited a red shift in the absorbance maximum for the surface plasmon band which was attributed to the increasing aggregation and cross linking within the film. Quantized double layer charging peaks suggest that film growth is selective toward a specific core size or exchange rate, either of which affect the number of potential linking ligands in the periphery of the MPCs. Multi-layer growth of films was only achieved with metal ions capable of coordinating within the cavity of the 15-crown-5 ether. Our exchange reaction parameters are in stark contrast to other types of MPC film assemblies.     

Making sense of sentences in schizophrenia: Electrophysiological evidence for abnormal interactions between semantic and syntactic processing.

Event-related potentials to critical verbs were measured as patients with schizophrenia and healthy controls read sentences word by word. Relative to their preceding context, critical verbs were (a) congruous, (b) incongruous and semantically unrelated to individual preceding words (pragmatic-semantic violations), (c) incongruous but semantically related to individual preceding words (animacy-semantic violations), or (d) syntactically anomalous. The N400 was modulated normally in patients, suggesting that semantic integration between individual words within sentences was normal in schizophrenia. The amplitude of the P600 to both syntactic and animacy-semantic violations was reduced in patients relative to controls. The authors suggest that, in schizophrenia, an abnormality in combining semantic and syntactic information online to build up propositional meaning leaves sentence processing to be primarily driven by semantic relationships between individual words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mixed Reality-Based Visualization Interfaces for Architecture, Engineering, and Construction Industry

Varied computing devices and automated sensors will enable new human-computer interface paradigms for interacting with digitally managed project information. The writers therefore propose the development of Mixed Reality (MR)-based computer interfaces, and especially Augmented Reality systems, for the architecture, engineering, and construction industry and describe the technologies and principles for applying such computer interfaces to support all phases of the constructed facility project life cycle. An Augmented Reality computer-aided drawing prototype is described as an experimental platform to study the human factors issues in interacting with Augmented Reality three-dimensional digital design models. Two critical research needs are cited for realizing effective Augmented Reality systems: (1) human factors research for development of visualization tools to enhance design comprehension and support collaborative work, and (2) the development of a technology infrastructure for “augmented” control and inspection interfaces to directly access digital project plan and site information that may be spatially referenced and displayed in the field. Research should be geared to advance knowledge regarding spatial cognition, human–computer interfaces, and computer-mediated human-to-human interactions, and it should address application of MR to all phases of the project life cycle.