Secured macro/micro-mobility protocol for multi-hop cellular IP

A Multi-hop Cellular IP (MCIP) network differentiates global and local domains in terms of macro/micro-mobility in heterogeneous multi-hop communication. However, a MCIP network is vulnerable to various attacks and compromises during macro/micro-mobility processes in an adversarial environment. Existing MCIP protocol does not provide macro/micro-mobility security protection for mobile stations. In this paper, we introduce and evaluate a secure macro/micro-mobility protocol (SM³P). In the proposed SM³P, mobile IP security has been extended for supporting macro-mobility across local domains through the process of multi-hop registration and authentication. In a MCIP local domain, a certificate-based authentication achieves the effective routing and micro-mobility protection from a range of potential security threats. Our evaluation and simulation demonstrates the effectiveness of the SM³P.     

Über die Addition von Nitrosylhydrogensulfat an Olefine

On the Addition of Nitrosyl Hydrogen Sulphate to Olefins By the addition of nitrosyl hydrogen sulphate to trisubstituted olefins in liquid sulphur dioxide as solvent the corresponding α-sulphatooximes may be obtained. The sulphato oximes are relatively unstable. They react with basic nucleophiles with substitution of the sulphato group; this reaction obviously proceeds according to an elimination-addition mechanism through nitrosoolefins as short-lived intermediates. In the presence of sulphuric acid and of saturated lower hydrocarbons nitrosyl hydrogen sulphate reacts with trisubstituted and asymmetrically disubstituted olefins, and after hydrolysis with water or with aqueous ammonia or aqueous sodium hydroxide the corresponding α-hydroxy oximes are obtained in good yields. By the reaction of the non-substituted cycloolefins the corresponding α-acetoxy oximes can be prepared in moderate yields.     

Renewable Source Based Non-biodegradable Polyurethane Coatings from Polyesteramide Prepared in One-Pot Using Oleic Acid

The highlight of the work was the preparation of polyesteramide in a one-pot reaction which avoids isolation of diethanol amide as it is normally required in polyesteramide preparation. In the present work, oleic acid was reacted with diethanol amine resulting in diethanol amide which further reacted with phthalic anhydride in the same reaction vessel without isolation and purification. Therefore the reaction is a one-pot, time-saving and cost-effective method as it requires minimum solvent and processing steps. In addition to this, the fatty acid used was a single fatty acid (oleic acid) that provides selective physico- chemical and anticorrosive properties for the resin. FT-IR and ¹H-NMR spectroscopic studies confirmed the structure of the polyesteramide. End group analysis and molecular weight were used to calculate the stoichiometric balance of the NCO/OH ratio in the preparation of polyurethane. The prepared resin was converted to polyurethane coatings by reacting with toluene diisocyanate and methylene diphenyl diisocyanate. Thermal stability, physico-chemical and coating properties of the polyurethane coatings were investigated. The polyurethane prepared showed a non-biodegradable nature so that it is of commercial interest and value for applications in various fields. Study of coatings was also carried out for properties like adhesion, impact resistance, pencil hardness and the bending test.     

Natural convection in a porous medium at high rayleigh numbers — application of prandtl's analogy

The problem of natural convection heat transfer from an isothermal vertical cylinder to a saturated porous medium is solved by the integral method making use of one-seventh profiles for velocity and temperature variation in the boundary layer. Prandtl's analogy is used to obtain the wall heat transfer coefficients. The results obtained for Rayleigh numbers greater than 10⁹ and Prandtl numbers 4 and 0.12 are compared with experimental data from literature show satisfactory agreement. Also an approximate closed form solution is presented for the case of a flat wall to predict local Nusselt numbers.     

Impact of Implicit Feedback Channel in Cooperative Relay Networks

In a multi-node network, cooperation among nodes is an effective means to enhance coverage and potentially increase the capacity. For such systems, schemes based on incremental relaying have great potential to improve the spectral efficiency by adapting the transmission to time varying channel conditions. The performance enhancement brought about by the presence of relays in such incremental relaying based cooperative systems is dependent on the level of cooperation (based on the relay information quality) and on coordination among the nodes. Coordination is achieved through the use of feedback channels, which incurs significant bandwidth penalty and brings down the spectral efficiency. In order to mitigate this, one can exploit an implicit feedback channel available due to broadcast nature of relay transmissions. Instead of using dedicated feedback channels, the implicit feedback channel is used to measure the relay information quality. Based on this information, the transmitter (source/relay) for the additional coded (redundancy) bits is determined. Such a mechanism enhances the reliability as it ensures the availability of correct information at the destination node for decoding. This paper studies the impact of such an implicit feedback channel by employing powerful codes which exhibit inherent incremental redundancy features, such as rate-compatible codes (rate-compatible punctured convolutional (RCPC) codes and punctured low-density parity-check (LDPC) codes) and rateless codes (Luby Transform (LT) codes). Theoretical analyses of the proposed scheme are presented, and supported with results from extensive simulation studies.     

Synthesis and Evaluation of Soy Fatty Acid Ester Estolides as Bioplasticizers in Poly(Vinyl Chloride)

Plasticizers are nonvolatile organic liquids that impart flexibility to polymers. Due to environmental, health, and safety reasons, the industry is looking for bioplasticizers to replace petroleum-derived phthalates. To fulfill this need, soy fatty acid ester estolides were synthesized, characterized, and evaluated as phthalate replacements. Soybean oil was transesterified with methanol or glycerol to form lower molecular weight fatty acid esters that were epoxidized and ring opened with acetic acid and acetylated to give the final products. Ring opening and acetylation of the epoxidized oleic acid esters gave acyclic acetate fatty acid ester estolides, whereas the polyunsaturated fatty acid esters, linoleate, and linolenate gave cyclic tetrahydrofuran derivatives and cross-linked higher molecular weight materials. The cyclization mechanism to form the tetrahydrofuran derivatives was postulated. Soy fatty acid ester estolides were compounded with formulated poly(vinyl chloride), (PVC) and tested for their functional properties. The physical and functional properties of the new bioplasticizers were compared with commercial plasticizers. The elasticity of PVC compounded with experimental plasticizers and commercial phthalates was comparable. PVC compounded with fatty acid methyl ester estolide showed lower glass transition temperature and similar tensile properties compared to PVC compounded with the commercial phthalate. PVC compounded with the glyceryl fatty acid ester estolide showed a higher glass transition temperature, higher tensile properties compared to PVC compounded with the commercial phthalate.     

Used lubricating oil regeneration by various solvent extraction techniques

The used lubricating oil regeneration using extraction technique has been widely known as one of the cheapest and most competent processes. The best performance of solvent was shown by R-11 as the lowest percent oil losses, followed by CFC-113, MEK, 1-butanol, and 2-propanol. This performance sequence could be also evaluated by method of solubility parameter difference (E_s) using Hildebrand and Peng–Robinson EoS approaches. The effectiveness of extraction parameters was also studied. The percent oil losses decreased with the extraction temperature. The values of optimum ratio of solvent to oil obtained by the E_s method gave reasonable results compared to the experimental method.     

Journalists as Crowdsourcerers: Responding to Crisis by Reporting with a Crowd

Widespread adoption of new information communication technologies (ICTs) is disrupting traditional models of news production and distribution. In this rapidly changing media landscape, the role of the journalist is evolving. Our research examines how professional journalists within a rural community impacted by Hurricane Irene successfully negotiated a new role for themselves, transforming their journalistic practice to serve in a new capacity as leaders of an online volunteer community. We describe an emergent organization of media professionals, citizen journalists, online volunteers, and collaborating journalistic institutions that provided real-time event coverage. In this rural context, where communications infrastructure is relatively uneven, this ad hoc effort bridged gaps in ICT infrastructure to unite its audience. In this paper, we introduce a new perspective for characterizing these information-sharing activities: the “human powered mesh network” extends the concept of a mesh network to include human actors in the movement of information. Our analysis shows how journalists played a key role in this network, and facilitated the movement of information to those who needed it. These findings also note a contrast between how HCI researchers are designing crowdsourcing platforms for news production and how crowdsourcing efforts are forming during disaster events, suggesting an alternative approach to designing for emergent collaborations in this context.     

Synthesis and Functional Evaluation of Soy Fatty Acid Methyl Ester Ketals as Bioplasticizers

A facile synthesis of the soy fatty acid methyl ester ketal has been accomplished using acetone in the presence of catalytic anhydrous ferric chloride starting from commercially available soy biodiesel (soy fatty acid methyl ester) after evaluating various synthetic procedures. The soy ketal product was fully characterized by nuclear magnetic resonance, infra-red and chromatography. The physical and analytical properties of soy ketal as determined by thermogravimetric analysis, viscosity acid and saponification values are acceptable for plasticizer applications. Soy ketal was compounded with polyvinyl chloride for evaluation of plasticizer properties such as efficiency, gelation, viscosity, volatility, thickening/aging behavior and stability. The thickening and aging behaviors of the soy ketal bioplasticizer are better than those of petroleum-based plasticizers such as diisononyl phthalate and diisononyl-cyclohexane dicarboxylate, but they need improvement in the areas of thermal stability and water extractability.     

Is P-Wave Velocity an Indicator of Saturation in Sand with Viscous Pore Fluid?

It is commonly assumed that within inundated sand the Skempton B value and P-wave velocity decrease with decrease in saturation. In centrifuge tests a common saturation procedure is to inundate the specimen with carbon dioxide while under a vacuum and then slowly introduce the viscous pore fluid. The B value and related saturation is difficult to measure in centrifuge models and P-wave velocity—saturation correlations have been used for this purpose. A laboratory emulation of centrifuge saturation procedures was made using a triaxial cell with top and bottom bender elements and a viscous methyl cellulose–water pore fluid. Contrary to expectations, the laboratory tests showed high P-wave velocities indicative of full saturation when B values were low. Numerical modeling of the laboratory tests indicated that if air bubbles within the pore fluid are numerous and closely spaced then there is a good correlation between saturation, B value, and P-wave velocity. However if the air bubbles are larger and only present in some of the pores then the P-wave velocity is not a good indicator of B value and average saturation. The laboratory tests also showed that placing the specimen under backpressure for several days increased saturation and related B values. It is suggested that this common laboratory procedure should be considered for saturating centrifuge test specimens.