Plastic deformation kinetics of fine-grained alumina

The plastic deformation kinetics of a commercial fine-grained alumina with ∼300 ppm MgO and grain sizes from 1.4 to 2.9 μm were determined in tension at 1475 °C to 1600 °C and strain rates from 10⁻⁵ to 10⁻³ s⁻¹, employing stress relaxation (SR) as the principal test mode. The constants in the Weertman-Dorn (W-D) equation were determined and had the following values: A=2.9±0.5×10⁹, n=2.2±0.1, p=1.9±0.1, Q=492±3 kJ/mole, and threshold stress σ ₀=0. These constants are in accord with grain boundary sliding (GBS) accommodated by dislocation glide and climb with Al³⁺ ion lattice diffusion as the rate-controlling mechanism.     

DIELS-ALDER Reaction with Styryl Derivatives of cyclo-hexenones,indazoles, benzisoxazoles and pyrazolines

The DIELS -ALDER reaction of 5-aryl-3-styryl-2-cyclohexenone derivatives 1 with N-aryl maleimide or maleic anhydride yields the adducts 4a–q and 5a–d . Hydrolysis of 4a or 5a gives the acid 6 . DIELS -ALDER reaction with 6-styryl indazoles 7 , benzisoxazoles 9 , and 3-styryl pyrazolines 11 gives the corresponding adducts 8, 10 , and 12 , respectively.     

Role of Lactic Acid in Corn Steeping and Its Relation with Starch Isolation

Corn grains were steeped in fresh SO₂ solution (300 ppm), old SO₂ solution (100 ppm, 0.55 g lactic acid per 100 ml) and fresh SO₂ with chemically pure lactic acid (100 ppm SO₂ + 0.55 g lactic acid per 100 ml). The water absorption rate in all trials using old SO₂ or low SO₂ with lactic acid in the first stage of the steeping process was higher. The solubilization and diffusion of protein was stronger in corn grains steeped completely in old SO₂ or low fresh SO₂ with lactic acid. Such treatments gave the highest starch recovery with lowest protein content in the isolated starch. The low starch content in hulls and fibers confirms the important role of lactic acid in presence of a low concentration of SO₂ (0.01%).     

Traffic management for TCP/IP over satellite ATM networks

Several Ka-band satellite systems have been proposed that will use ATM technology to seamlessly transport Internet traffic. The ATM UBR, GFR, and ABR service categories have been designed for data. However, several studies have reported poor TCP performance over satellite ATM networks. We describe techniques to improve TCP performance over satellite ATM networks. We first discuss the various design options available for TCP end systems, IP-ATM edge devices, as well as ATM switches for long-latency connections. We discuss buffer management policies, guaranteed rate services, and the virtual source/virtual destination option in ATM. We present a comparison of ATM service categories for TCP transport over satellite links. The main goal of this article is to discuss design and performance issues for the transport of TCP over UBR, GFR, and ABR services for satellite ATM networks     

17—QUANTITATIVE ANALYSES OF WEFT-KNITTED STRUCTURES PART IV: THE DETERMINATION OF THE MAGNITUDES OF B1, B2, AND B3 AND THE EXTENSION OF THE WORK TO GENERAL MULTI-COLOUR-JACQUARD STRUCTURES

The optimum design of experiment for the determination of the magnitudes of the component units of the weft-knitted jacquard structures, B ₁, B ₂, and B ₃, is discussed in detail. Some experimental results are reported. The prediction accuracy of using the technique of independent distinct units (IDU), by means of a suggested optimum experiment, proved to be very satisfactory in predicting the length of yarn of one design repeat of an arbitrary two-colour-jacquard example. The extension of the work to general multi-colour-jacquard structures is given.     

Synthesis of New Silicone-based Adducts to Functionalize Cotton Fabric

Silicon - New silicone based adducts were synthesized by reacting equimolar ratio of carbinol polydimethylsiloxane (CPDMS), 2,4-toluene diisocyanate (TDI) and polyethylene glycol (PEG, having a...     

Rheological Behavior of Some Polymeric Sizing Agents Alone and in Admixtures

Solutions of seven polymeric sizing agents, viz., four kinds of poly vinyl alcohols (PVAs), carboxy methyl starch (CMS), and sodium polyacrylate (PA) in addition to their binary mixtures, at a concentration of 10%–-were rheologically characterized at 80°C. It was found that: (1) all these solutions behaved as non-Newtonian shear thining fluids that displayed measurable thixotropic character, and (2) the apparent viscosity, at a constant shear rate, and the extent of thixotropy depended both on the kind of sizing agent and on the composition of the binary mixtures. The flow behavior index and the shear thining index of each solution, as deduced from the power law, were estimated, and hence the degree of pseudoplasticity and the flow properties of each solution were evaluated.     

Synthesis,characterization, and thermal stability of novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s bearing pendant groups and their corresponding poly(ether-amide-1,3,4-oxadiazole)s

Four novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s containing various pendant groups on their aromatic rings were synthesized from p-aminosalicylic acid hydrazide (PASH) with an equimolar amount of either 4,4′-(1,4-phenylenedioxy)dibenzoyl chloride (1a), 4,4′-(2,5-tolylenedioxy)dibenzoyl chloride (1b), 4,4′-(2-tert-butyl-1,4-phenylenedioxy)dibenzoyl chloride (1c), or 4,4′-(2,5-biphenylenedioxy)dibenzoyl chloride (1d) via a low temperature solution polycondensation reaction. A polyamide-hydrazide without the ether and pendant groups, poly[4-(terephthaloylamino)salicylic acid hydrazide, PTASH, is also investigated for comparison. It was synthesized from PASH and terephthaloyl chloride by the same synthetic route. The polymer intrinsic viscosities ranged from 4.5 to 2.47 dlg⁻¹ in N,N-dimethyl acetamide (DMAc) at 30 °C and decreased with the introduction of the ether and pendant groups into the polymer. All the polymers were soluble in DMAc, N,N-dimethyl formamide (DMF), and N-methyl-2-pyrrolidone (NMP) and their solutions could be cast into flexible films with good mechanical strengths. Further, they exhibited a great affinity to water sorption. Their solubility and hydrophilicity increased with introduction of the ether and pendant groups into the polymer. The prepared polymers could be thermally cyclodehydrated under nitrogen atmosphere into the corresponding poly(ether-amide-1,3,4-oxadiazole)s approximately in the region of 300–450 °C. The introduction of the flexibilizing ether linkages and the pendant groups into the polymer improves the solubility of the resulting poly(ether-amide-1,3,4-oxadiazole)s compared to poly(amide-1,3,4-oxadiazole) free from these groups.     

Real-time hardware acceleration of the trace transform

The trace transform is a novel algorithm that has been shown to be effective in a number of image recognition tasks. It is a generalisation of the Radon transform that has been widely used in image processing for decades. Its generality—allowing multiple functions to be used in the mapping—leads to an algorithm that can be tailored to specific applications. However, its computation complexity has been a barrier to its widespread adoption. By harnessing the heterogeneous resources on a modern FPGA, the algorithm is significantly accelerated. Here, a flexible system is developed that allows for a wide array of functionals to be computed without re-implementing the design. The system is fully scalable, such that the number and complexity of functionals does not affect the speed of the circuit. The heterogeneous resources of the FPGA platform are then used to develop a set of flexible functional blocks that can each implement a number of different mathematical functionals. The combined result of this design is a system that can compute the trace transform on a 256 × 256 pixel image at 26 fps, enabling real-time processing of captured video frames.