Effects of Magnetic Saturation on the Performance of Thyristor Commutatorless Motors

The ratings and the other constants of motors are designed within a magnetically saturated region. Studies of motors, however, have dealt with and have been limited to the problems in a linear region for the sake of simplicity. A basic study of the operating performance of commutatorless motors in the magnetically saturated region is presented here. The magnetic saturation is evaluated in terms of the permeance of a magnetic circuit. Digital simulation based on this basic study reveals the effects of the magnetic saturation on the static characteristics of the commutatorless motors. The theory established in this paper for the analysis of the effects of the magnetic saturation can successfully be applied to other kinds of motors as well as to commutatorless motors.     

Performance Analysis of Reassembly and Multiplexing Queueing with Long-Range-Dependent Input Traffic

This paper studies the impact of long-range-dependent (LRD) traffic on the performance of reassembly and multiplexing queueing. A queueing model characterizing the general reassembly and multiplexing operations performed in packet networks is developed and analyzed. The buffer overflow probabilities for both reassembly and multiplexing queues are derived by extending renewal analysis and Bene fluid queue analysis, respectively. Tight upper and lower bounds of the frame loss probabilities are also analyzed and obtained. Our analysis is not based on existing asymptotic methods, and it provides new insights regarding the practical impact of LRD traffic. For the reassembly queue, the results show that LRD traffic and conventional Markov traffic yield similar queueing behavior. For the multiplexing queue, the results show that the LRD traffic has a significant impact on the buffer requirement when the target loss probability is small, including for practical ranges of buffer size or maximum delay.     

Positive Emotion and Health: Going Beyond the Negative.

This study examined the relationships between positive emotions and health. Two positive emotions were considered, hope and curiosity, in conjunction with 3 physician-diagnosed disease outcomes: hypertension, diabetes mellitus, and respiratory tract infections. Medical data were abstracted over a 2-year period from 1,041 patient records from a multispecialty medical practice, and emotions were assessed through a mailed questionnaire. Across 3 disease outcomes, higher levels of hope were associated with a decreased likelihood of having or developing a disease. Higher levels of curiosity were also associated with decreased likelihood of hypertension and diabetes mellitus. Results suggest that positive emotion may play a protective role in the development of disease. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An ultrahigh‐definition display using the pixel‐offset method

Abstract— An ultrahigh‐definition display system quadrupling the horizontal and vertical resolution of HDTV has been developed. In order to obtain the ultrahigh definition, four LCD panels (red, green 1, green 2, and blue) are combined using the spatial pixel‐offset method. Therefore, only green images have an ultrahigh resolution of 4096 × 7680 pixels, while red and blue images have 2048 × 3840 pixels. The ultrahigh resolution was confirmed by subjective assessment testing. The scores of the test have the same tendencies as the SQRI values. The necessary accuracy of the convergence correction is calculated to be within 0.3 pixels by the modified s‐CIELAB method.     

Learning from Cluster Examples

Learning from cluster examples (LCE) is a hybrid task combining features of two common grouping tasks: learning from examples and clustering. In LCE, each training example is a partition of objects. The task is then to learn from a training set, a rule for partitioning unseen object sets. A general method for learning such partitioning rules is useful in any situation where explicit algorithms for deriving partitions are hard to formalize, while individual examples of correct partitions are easy to specify. In the past, clustering techniques have been applied to such problems, despite being essentially unsuited to the task. We present a technique that has qualitative advantages over standard clustering approaches. We demonstrate these advantages by applying our method to problems in two domains; one with dot patterns and one with more realistic vector-data images.     

Effect of electron beam radiation on the performance of biodegradable Bionolle-jute composite

To study the radiation effect on the physical, thermal, mechanical and degradable properties of biodegradable polymer Bionolle (chemosynthetic polyester poly(1,4-butylene succinate)), Bionolle films prepared by compression molding process and were irradiated with electron beam (EB) radiation of different doses. Gel content was found to increase with increase of radiation dose. Tensile strength of Bionolle was enhanced when Bionolle film was exposed under 20 kGy radiation. The loss of tensile strength of both unirradiated and irradiated Bionolle is 70% and 8% due to thermal aging at 70°C for 30 days. Both irradiated and unirradiated films of Bionolle were subjected to different degradation test in compost (soil burial), enzyme and storage degradation both in outdoor and indoors conditions. The loss of weight due to soil (compost) degradation test decreased with increase of radiation dose. The loss of weights of irradiated samples were found to be very less within the first three months of compost degradation. After 120 days, tensile strength of the Bionolle films irradiated at 20 kGy and 100 kGy were 68 MPa and 40 MPa, respectively, compared to the value (30 MPa) of the unirradiated Bionolle samples. Loss of tensile strength of irradiated Bionolle due to storage degradation like in roof, ground and indoors was minimum compared to unirradiated Bionolle. The weight loss due to enzymatic degradation was found to be decreased with increase of radiation dose. The tensile strength of jute reinforced Bionolle composites (23 wt.-% jute content) irradiated at 20 kGy was found to be higher (22%) than that of an unirradiated composite.     

Solid‐state characterization and the thermal properties of stereoregular poly(vinyl chloride) prepared by urea clathrate polymerization

The solid‐state characterization of highly stereoregular poly(vinyl chloride) (PVC) prepared by urea clathrate polymerization was carried out by using various instrumental analyses. The structural differences of PVC appeared most remarkably in solubility to organic solvents, IR, WAXD, and solid‐state ¹³C‐NMR spectra. The value of the glass transition temperature (T_g) was about 90°C, not as high as expected, although its detection was quite difficult. The thermal stability was poor, as evidenced by the easy discoloration of this polymer by heat treatment, which was related to the absence of a termination reaction. Dynamic ESR spectra in the solid state clearly indicate that the radical formation occurs at such a low temperature as 160°C in the initial degradation stage. The degradation characteristics of urea clathrate PVC were critically discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2820–2825, 1999     

Hydrogel coating of RVNRL film by electron‐beam irradiation

The tackiness properties of radiation‐vulcanized natural rubber latex (RVNRL) film surfaces coated by various monomers were investigated in order to define the suitable hydrogels which reduce the tackiness of the film. In this context, different types of monomers, namely, N‐vinyl‐2‐pyrrolidone (NVP), N,N‐dimethylaminoethylamide (DMAEA), acrylic acid (AAc), n‐butyl acrylate (n‐BA), and 2‐hydroxyethyl methacrylate (HEMA) as well as the monomer mixtures were tried with varying degrees of success. Coating the RVNRL film with 80% HEMA/20% n‐BA by irradiation at 80 kGy using a low‐energy electron beam gave a remarkable reduction in the surface tackiness of the RVNRL film. Several other attempts were made such as priming the RVNRL film with acid and aluminum sulfate prior to coating, mixing the aluminum sulfate into the monomer mixtures, and dipping the partially wet RVNRL film into the monomer to enhance the wettability of the monomers with the film. The photomicrographs taken illustrate that the decrease in tackiness with the coating is due to the increase of the surface roughness at an 80‐kGy irradiation dose. The studies also revealed that the reduction in the contact angle and the increase in water absorption of the RVNRL film after irradiation are due to the formation of the hydrogel layer. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1421–1428, 1999     

Crosslinking of cis-1,4-polyisoprene rubber by electron beam irradiation

Various unsaturated polyfunctional monomers were kneaded into cis-1,4-polyisoprene containing fillers under 80°C and then irradiated using an electron beam accelerator to prepare vulcanized rubber with good quality. Results showed that 2G (diethyleneglycol dimethacrylate) is the best sensitizer. The optimal tensile strength of vulcanized IR was obtained by using 14 phr 2G and irradiated to 180 kGy. Compared with the sulfur vulcanizate, greater values of tensile strength, elongation at break, and 100% stress were found with the radiation-cured IR. Their Young's modulus and tan σ were similar. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 113–116, 1997