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Peace Driving: Case Studies of Wi-Fi Usage
Get PDFWireless networking technologies, under the umbrella of the IEEE 802.11 suite of standards and commonly referred to as Wi-Fi, is now commonplace technology in both the home and office. In this work, we present the results of studies into wireless networking uptake and security within two town communities in the UK. Our work concentrates on the geographical positioning of wireless access points (APs) and the security measures used to protect these liberating technologies from unwanted misuse, often referred to as war driving, we employ the title peace driving, for wireless networking surveying which aims to address security issues in wi-fi networks. The results from our study show significant uptake of wireless networking in both the residential and business areas surveyed. The number of access points present in some residential areas is large, and given the relatively small distances between access points there is undoubtedly traffic which is crossing private boundaries. These findings are corroborated across both the communities which were studied. We suggest that similar sized and constituent communities are representative of others in the UK and find similar trends between the two studied as part of this work
Type-D personality mechanisms of effect: The role of health-related behavior and social support
No full textObjective
To (a) investigate the prevalence of type-D personality (the conjoint effects of negative affectivity and social inhibition) in a healthy British and Irish population; (b) to test the influence of type-D on health-related behavior, and (c) to determine if these relationships are explained by neuroticism.
Methods
A cross-sectional design was employed; 1012 healthy young adults (225 males, 787 females, mean age 20.5 years) from the United Kingdom and Ireland completed measures of type-D personality, health behaviors, social support, and neuroticism.
Results
The prevalence of type-D was found to be 38.5%, significantly higher than that reported in other European countries. In addition, type-D individuals reported performing significantly fewer health-related behaviors and lower levels of social support than non-type-D individuals. These relationships remained significant after controlling for neuroticism.
Conclusion
These findings provide new evidence on type-D and suggest a role for health-related behavior in explaining the link between type-D and poor clinical prognosis in cardiac patients
New starches: Physicochemical properties of sweetsop (Annona squamosa) and soursop (Annona muricata) starches
Get PDFStarch from the fruits of sweetsop (Anonna squamosa) and soursop (Anonna muricata) were isolated and purified and the fat, ash, phosphorus and protein contents measured. The amount of amylose present was determined spectrophotometrically and found to be very similar ( 19%) for both starches. Scanning electron microscopy showed very small indented and spherical granules from both with an average granule size of 4.84 μm and 4.72 μm, respectively. The physicochemical properties, namely the swelling power, solubility, pasting characteristics, paste clarity and freeze–thaw stability were studied to assess the functionality of the starch pastes as hydrocolloids. The sweetsop starch showed higher swelling power and solubility compared to soursop starch and had a lower gelatinization temperature indicating a weaker granular structure. Sweetsop starch exhibited a lower pasting temperature, higher viscosity peak, higher viscosity breakdown and lower setback, higher paste clarity and freeze–thaw stability compared to soursop starch. The low gelatinization temperature and high freeze thaw stability of sweetsop starch are comparable to that of waxy corn. The properties of sweetsop indicate that it has potential for application as a thickener in frozen foods
Supercritical chemical fluid deposition of high quality compound semiconductors
No full textThe main advantage of deposition from supercritical fluids over conventional CVD is the ability to fill high aspect ratio templates. Deposition of metals, indirect semiconductors and insulators into templates with dimensions down to 3 nm has been demonstrated by others, with no apparent pore blocking. In this paper we present a demonstration that it is also possible to deposit high quality, luminescent compound semiconductor films from supercritical CO2 or CO2/hexane mixtures. Depositions of CdS and III-V materials such as InP have been achieved through careful optimisation of precursor chemistry, reactor geometry and deposition conditions, supported by detailed measurements of the semiconductor film propertie
Computation of specific absorption rate in the human body due to base-station antennas using a hybrid formulation
Get PDFA procedure for computational dosimetry to verify safety standards compliance of mobile communications base stations is presented. Compared with the traditional power density method, a procedure based on more rigorous physics was devised, requiring computation or measurement of the specific absorption rate (SAR) within the biological tissue of a person at an arbitrary distance. This uses a hybrid methd of moments/finite difference time domain(MoM/FDTD) numerical method in order to determine the field or SAR distribution in complex penetrable media, without the computational penalties that would result from a wholly FDTD simulation. It is shown that the transmitted power allowed by the more precise SAR method is, in many cases, between two and five times greater than that allowed by standards implementing the power flux density method
Autofocus for inverse synthetic aperture radar (ISAR) imaging
Get PDFAutofocus is a key step of inverse synthetic aperture radar (ISAR) imaging. In this paper four new approaches to autofocussing based on the application of beamforming and subspace concepts to ISAR imaging are developed. Their relations to maximum likelihood (ML) estimation are identified. A common feature of these techniques is the estimation of the complex vector formed by the exponential function of phase rather than phase itself so that phase unwrapping is obviated. The Cramer Rao lower bound (CRLB) of the estimated complex vector corresponding to translational motion and the CRLB of the estimated distance between two scatterers are derived. The results of processing simulated and real data confirm the validity of proposed approaches
Characterization of the Surface-Active Components of Sugar Beet Pectin and the Hydrodynamic Thickness of the Adsorbed Pectin Layer
No full textThe fraction of sugar beet pectin (SBP) adsorbed onto limonene oil droplets during emulsification has been isolated, and its chemical and physicochemical characteristics have been determined. While the SBP sample itself was found to contain 2.67 and 1.06% protein and ferulic acid, respectively, the adsorbed fraction contained 11.10% protein and 2.16% ferulic acid. The adsorbed fraction was also found to have a higher degree of acetylation, notably at the C2 position on the galacturonic acid residues, and was also found to contain a higher proportion of neutral sugars, which are present in the ramified side chains of the pectin molecules. The thickness of the layer of SBP adsorbed onto polystyrene latex particles was studied by dynamic light scattering and was found to increase with increasing surface coverage. It was found to have a value of 140 nm at plateau coverage, which closely corresponded to the hydrodynamic diameter of the pectin chains. The adsorbed layer thickness was found to be sensitive to pH and the presence of electrolyte. The thickness at a surface coverage of 20 mg/m2 in the absence of electrolyte at pH 4 was 107 nm and at pH 8.8 was 70 nm, while at pH 4 in the presence of 10 mM NaCl the thickness was found to be 70 nm. It was concluded that the SBP molecules form multilayers at the surface due to electrostatic interaction between the positively charged protein moieties and the galacturonic acid residues. The removal of calcium from the SBP had no effect on the adsorbed layer thickness; hence, multilayer formation due to calcium ion cross-linking was considered unlikely
Managing the Bursty Nature of Packet Traffic using the BPTraSha Algorithm
Get PDFThe rapid development of network technologies has widened the scope of Internet applications and, in turn, increased both Internet traffic and the need for its accurate measurement, modelling and control. Various researchers have reported that traffic measurements demonstrate considerable burstiness on several time scales, with properties of self-similarity. The self-similar nature of this data traffic may exhibit spikiness and burstiness on large scales with such behaviour being caused by strong dependence characteristics in data: that is, large values tend to come in clusters and clusters of clusters and so on. Several studies have shown that TCP, the dominant network (Internet) transport protocol, contributes to the propagation of self-similarity. Bursty traffic can affect the Quality of Service of all traffic on the network by introducing inconsistent latency. It is easier to manage the workloads under less bursty (i.e. smoother) conditions. In this paper, we examine the use of a novel algorithm, the Bursty Packet Traffic Shaper (BPTraSha), for traffic shaping, which can smooth out the traffic burstiness. Experimental results show that this approach allows significant traffic control by smoothing the incoming traffic. BPTraSha can be implemented on the distribution router buffer so that the traffic’s bursty nature can be modified before it is transmitted over the core network
A novel synthetic route to metal-polymer nanocomposites by in situ suspension and bulk polymerizations
No full textA novel strategy to synthesize hybrid metal–polymer nanocomposites has been achieved based on in situ free radical suspension and bulk polymerization techniques. An organometallic precursor complex is dissolved in a liquid monomer phase prior to polymerization, where upon the precursor molecules are immobilized inside the polymer matrix during its formation. In a separate step, metal nanoparticles are then formed by H₂-assisted reduction of the precursor in the polymer product in supercritical carbon dioxide (scCO₂). The synthesized nanocomposites were characterized by GPC, TGA, SEM and TEM. It is shown that the metal nanoparticles are uniformly distributed inside the polymer matrix and the inclusion of the metal precursor has no significant influence on the polymerization process. The current work represents a simple and universal way to prepare a variety of metal–polymer nanocomposite functional materials
Moving beyond the limits of language: autobiographical narrative in animation shorts
Get PDFThe paper examines five animated shorts by different artists which explore autobiographical themes. The main areas under analysis are the themes themselves, narrative structures, visualisation and the motivation for each artist in making their film. A particular concern is whether therapeutic benefit has resulted for the artist both in terms of the animation production process and in the potential of the films to communicate a personal truth