Miscibility behavior of blend of polyesteramides of linseed oil and dehydrated castor oil with poly(methacrylic acid)

Blending of two polymers in solution is a simple and cost‐effective technique to improve upon the physical and mechanical properties of the component polymers through synergism. To obtain maximum synergy in their properties, the component polymers should be miscible with each other on molecular scale. Polymer blends of complex physicomechanical properties are being actively investigated. Poly(methacrylic acid) (PMAA), a commercial polymer, yields transparent, hard, brittle, and water‐sensitive films. It has been blended with natural polymers like dextran, collagen, and gelatin to obtain films with improved physical and mechanical characteristics. Polyesteramides, which are easily synthesized from vegetable seeds oil, a sustainable resource, have found application in surface coatings. These oligomeric products do not make free standing films in the ambient condition. The polyesteramides from vegetable seeds oil can be used to obtain blend with PMMA of improved mechanical and water absorption properties. In this study, linseed oil polyesteramide (LOPEA) and dehydrated castor oil polyesteramide (DCPEA), the source oils with different unsaturation in their fatty acid chains, were blended with PMAA through mixing in solution in the ratio DCPEA/LOPEA: PMAA as 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, and 20/80. In the first instance, the miscibility of the two components was investigated in solution by viscosity and ultrasonic measurements and in solid phase through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Moisture absorption by the blend was also studied. DCPEA and LOPEA show immiscibility with PMAA in solution phase while LOPEA with more unsaturation in the fatty acid chain of the oil was found more immiscible than DCPEA. DCPEA shows a narrow miscibility window in the solid phase while LOPEA was found immiscible with PMAA in the solid phase too. Uptake of moisture was found to be markedly reduced in the blends of DCPEA/LOPEA with PMAA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1367–1374, 2007:     

Inhibitory Effect of Monoterpenes on Response of Pityogenes bidentatus to Aggregation Pheromone Released by Piezoelectric Sprayer for Precision Release of Semiochemicals

A piezoelectric sprayer for dispensing semiochemicals was developed and used for a field test of bark beetle semiochemicals. The sprayer consists of a geared pump that pushes a syringe slowly to dispense semiochemicals in solvents through a microtube to a glass micropipet fixed to a piezoelectric high-frequency vibrator. The frequency is adjusted via a function generator to about 120 kHz until the harmonic properties of the glass micropipet, drawn by an electrophysiological pipet puller, cause vibrations that atomize the solvent from the micropipet tip. The sprayer, syringe, pump, function generator, and power supply were hung on one arm of a rotating trap pair (traps 6 m apart) that was slowly rotated at 2 revolutions per hour (rph) to even out the position effects on trap catches. The aggregation pheromone components of Pityogenes bidentatus, grandisol and cis-verbenol, were released by standard tube dispensers in one trap and compared to the release of similar amounts by the sprayer in the other trap. No significant differences in catch were observed. No effect of the solvent hexane on aggregation could be observed. The trap pair also caught approximately equal numbers of bark beetles when the baits were identical. The release of (+)and (–)--pinene, (+)-3-carene, and terpinolene, monoterpenes of host Scotch pine, Pinus sylvestris, at increasing rates from 0.01 to 10 log-equivalents in decadic steps (each at 0.1–100 g/min) resulted in decreasing responses to aggregation pheromone (only 9% at highest rate). Inhibition by the individual monoterpenes tested at the 100 g/min rate was significant for (+)and (–)--pinene and terpinolene (12, 13, and 15% of control, respectively). The inhibition by the host Scotch pine monoterpenes may allow P. bidentatus to avoid resistant trees that release large amounts of toxic monoterpenes in their resin and instead colonize dying and diseased limbs or slash, the usual host substrate. The piezoelectric sprayer should prove generally useful to dispense precise amounts of semiochemicals in field and laboratory experiments.     

Speech enhancement with an adaptive Wiener filter

This paper proposes an adaptive Wiener filtering method for speech enhancement. This method depends on the adaptation of the filter transfer function from sample to sample based on the speech signal statistics; the local mean and the local variance. It is implemented in the time domain rather than in the frequency domain to accommodate for the time-varying nature of the speech signals. The proposed method is compared to the traditional frequency-domain Wiener filtering, spectral subtraction and wavelet denoising methods using different speech quality metrics. The simulation results reveal the superiority of the proposed Wiener filtering method in the case of Additive White Gaussian Noise (AWGN) as well as colored noise.     

Characterization of Pheromone Blend for Grapevine Moth, Lobesia botrana by Using Flight Track Recording

The behavioral responses of Lobesia botrana males to calling females, pheromone gland extracts, and synthetic sex pheromones were recorded in a wind tunnel. Gland extracts and synthetic pheromones were released from a pheromone evaporator. The numbers of males reaching the source and their flight tracks in response to calling females and pheromone gland extracts were compared to those of synthetic blends. Upwind flights to natural sex pheromone were straighter and faster than to a three-component blend of (E)-7,(Z)-9-dodecadienyl acetate (E7,Z9–12:Ac), (E)-7,(Z)-9-dodecadien-1-ol (E7,Z9–12:OH), and (Z)-9-docecenyl acetate (Z9–12:Ac) (100:20:5). The optimum ratio of E7,Z9–12:OH and Z9–12:Ac to E7,Z9–12:Ac was found to be 5% and 1%, respectively. An additional seven compounds identified in the sex pheromone gland were investigated for their biological activity. Two unsaturated acetates, i.e., (E)-9-dodecenyl acetate (E9–12:Ac) and 11-dodecenyl acetate (11–12:Ac), increased the number of males reaching the source as well as straightness, linear velocity, and decreased the track angle of upwind flight. Optimum response was obtained by releasing 10 pg/min E7,Z9–12:Ac in a mixture with 0.5 pg/min E7,Z9–12:OH, 0.1 pg/min Z9–12:Ac, 0.1 pg/min E9– 12:Ac and 1 pg/min 11-12–Ac. The saturated acetates previously identified in the female glands were biologically inactive.     

A secure and improved multi server authentication protocol using fuzzy commitment

Multimedia Tools and Applications - The advancement in communication and computation technologies has paved a way for connecting large number of heterogeneous devices to offer specified services....     

Light weight model for intra mode selection in HEVC

Multimedia Tools and Applications - The High Efficiency Video Coding (HEVC) efficiently reduces the size of the multimedia contents, but at the cost of high computation complexity. In order to make...     

Optical properties of amorphous Ge28-xSe72Sbx thin films

Bulk glasses of formal composition Ge_28−xSe₇₂Sb_x with 0≤x≤28 were prepared by applying the quench technique. The optical transmission spectra—using a melt were measured in the range from 200 to 1200 nm for Ge_28−xSe₇₂Sb_x films which are prepared by thermal evaporation technique. A simple, straightforward procedure suggested by Swanepoel, which is based on the use of interference fringes, has been applied to calculate the film thickness. On other hand the driving absorption coefficient (α), consequently the band tail width E_e and the optical band gap have been estimated. The real (ε′) and imaginary parts (ε″) of the dielectric constant have been determined and the optical band gap can also be calculated as a function of imaginary part (ε″). The dispersion parameters such as E₀(single-oscillator energy), E_d (dispersive energy) and M₋₁, M₋₃ (moments) were discussed in terms of the single-oscillator Wemple–DiDomenico model.     

A secure biometric based multi-server authentication scheme for social multimedia networks

Social networking is one of the major source of massive data. Such data is not only difficult to store, manipulate and maintain but it’s open access makes it security prone. Therefore, robust and efficient authentication should be devised to make it invincible against the known security attacks. Moreover, social networking services are intrinsically multi-server environments, therefore compatible and suitable authentication should be designed accordingly. Sundry authentication protocols are being utilized at the moment and many of them are designed for single server architecture. This type of remote architecture resists each user to get itself register with each server if multiple servers are employed to offer online social services. Recently multi-server architecture for authentication has replaced the single server architecture, and it enable users to register once and procure services from multiple servers. A short time ago, Lu et al. presented two authentication schemes based on three factors. Furthermore, both Lu et al.’s schemes are designed for multi-server architecture. Lu et al. claimed the schemes to be invincible against the known attacks. However, this paper shows that one of the Lu et al.’s scheme is susceptible to user anonymity violation and impersonation attacks, whereas Lu et al.’s second scheme is susceptible to user impersonation attack. Therefore an enhanced scheme is introduced in this paper. The proposed scheme is more robust than subsisting schemes. The proposed scheme is thoroughly verified and validated with formal and informal security discussion, and through the popular automated tool ProVerif. The in-depth analysis affirms that proposed scheme is lightweight in terms of computations while attaining mutual authentication and is invincible against the known attacks, hence is more suitable for automated big data analysis for social multimedia networking environments.     

Nonlinear stability,excitation and soliton solutions in electrified dispersive systems

A weakly nonlinear theory of wave propagation in two superposed dielectric fluids in the presence of a horizontal electric field is investigated in (2+1)-dimensions. The equation governing the evolution of the amplitude of the progressive waves is obtained in the form of a two-dimensional nonlinear Schrödinger equation. A three-wave resonant interaction for nonlinear excitations created from electrohydrodynamic capillary-gravity waves is observed to be possible in a dispersive medium with a self-focusing cubic nonlinearity. Under suitable conditions, the nonlinear envelope equations for the resonant interaction are derived by using multiple scales and inverse scattering methods, and an explicit three-wave soliton solution is discussed. Both the dynamic properties and the modulational instability of finite amplitude electrohydrodynamic wave are studied for the cubic nonlinear Schrödinger equation by means of linearized stability analysis and the nonlinear interaction coefficient. We show that the trajectories in phase space exhibit different behavior with the increase of nonlinear perturbations, and we determine the electric field and wavenumber ranges at which the original point is elliptic or hyperbolic, respectively. It is found also that the presence of the electric field in the equation modifies the nature of wave stability and soliton structures, and that the amplitude and width of the soliton are decreased and increased, respectively, when the electric field value increases.     

A supply network-modelling system for a small- to medium-sized manufacturing company

During the late 1990s and early 2000s, the profile of global manufacturing has experienced many changes. There is anecdotal evidence that many western manufacturing companies have chosen to expand their manufacturing base across geographical boundaries. The common reasons sited for these ventures are to exploit less expensive labour markets, to establish a presence in expanding markets and in response to the threat of new competition. Whilst a global manufacturing base can prove to have many cost and sales benefits, there are also many disadvantages. Logistics operations can often increase in complexity leading to higher reliance on planning and effective interpretation of demand data. In response, systems modelling has remerged as a fertile research area after many years. Many modelling and simulation techniques have been developed, but these have had very limited practical success. The authors have identified that majority of these simulation techniques rely upon a detailed market structure being known, when this is rarely the case. This paper describes the outcome of a research project to develop of a pragmatic set of tools to gather, assess and verify supply chain structure data. A hybrid collection of technologies are utilised to assist these operations and to build a dynamic supply network model.