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ABSTRACT In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble [...]

Background Sedation and analgesia scales promote a less-distressing experience in the intensive care unit and minimize complications for patients receiving mechanical ventilation. Obiectives To evaluate outcomes before and after introduction [...]

In this study, nanocomposites with binary elements of poly (ethylene-co-ethyl acrylate)/carbon nanotube (EEA/CNT) were prepared so that their thermal and electrical characteristics and morphology, not reported in any literature, could be measured. For the thermal characteristics, their thermal degradation and activation energy were measured by using the thermogram (TG) curve, which was obtained by a heating from 100 [degrees]C to 600 [degrees]C with a thermogravimetric analysis (TGA). In addition, after maintaining a thermal equilibrium at each temperature of 25 [degrees]C, 50 [degrees]C, 75 [degrees]C, 100 [degrees]C, 125 [degrees]C and 150 [degrees]C, their thermoluminescence was measured for 20 minutes. Then, the volume resistivity of EEA/CNT was measured by means of ASTM D991. Morphology of EEA/CNT was measured at 15 kV. First, with the TGA experiments, the thermal degradation temperatures of the specimens containing a CNT were found to shift to a higher temperature region, while activation energy values between 204 kJ/mol and 213 kJ/mol were obtained. Secondly, with the thermoluminescence experiment, the specimens containing a CNT were found to show a much smaller thermoluminescence than the specimens without a CNT. Thirdly, the volume resistivity was lowered as the CNT content increased, which is not enough to create a semiconductivity. This is thought to reveal that the melting blend method has a worse dispersibility than the solution method. Lastly, with the measurements of the fractured surfaces from the field emission scanning electron microscope (FESEM) experiment, it was observed that the CNT was dispersed in the form of many lumps as its content increased. Index Terms--EEA/CNT, activation energy, volume resistivity, morphology.

Ceramic seals are widely used in many severe applications such as in corrosive, high temperature and highly loaded situations especially in hot chemical water-based extreme environments for automobile water pumps. Presently, polymeric materials are used as the counter part for alumina ceramic seals to reduce the ceramic-to-ceramic wear. As a result, leaks are very commonly observed from water pump during services. Consequently, it is needed to improve the surface properties of the ceramic seals using a surface modification technique such as a thin film coating process to meet the increasing demand of more stability, more durability, and lower friction of coefficient in those extreme environments. To meet these challenges, we have applied DLC (diamond-like carbon) coatings on alumina using a PIID (plasma immersion ion deposition) technique intended for seal applications. The DLC-coated specimens were tested under a wide range of temperature conditions, from room temperature up to 400[degrees]C, using a high temperature pin-on-disk tribo-tester. After that, the wear-tested specimens were analyzed using SEM with EDS to characterize the worn surfaces. Morphological changes of the DLC coated surfaces before and after the wear tests were studied. Under certain deposition conditions DLC performed very well up to 400[degrees]C. However, under other conditions, DLC failed catastrophically. In this paper we will present the friction and wear characteristics of the DLC-coated alumina. Finally, we will discuss the failure mode of DLC coatings. [DOI: 10.1115/1.2345395] Keywords: diamond-like carbon coatings, high temperature wear and friction, plasma immersion ion deposition

In this paper, the epoxy elasticity factors were investigated by thermomechanical analysis (TMA), dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA) and field emission scanning electron microscope (FESEM) to improve toughness and reduce brittleness of existing epoxy resin. Dumbbell shaped specimens were made and tested at rates of 0, 20 and 35 parts per hundred resins (phr). TMA and DMTA temperatures ranged from -20 to 200[degrees]C and TGA ranged from 0 to 600[degrees]C. The glass transition temperature (Tg) of elastic epoxy was measured by thermal analysis. Also investigated were the thermal expansion coefficient (a), the high-temperature characteristics, modulus and the loss factor (Tan [delta]). We analyzed the structure using FESEM and have found elastomer particles (elastic-factors) in the elastic epoxy matrix. We have made elastic epoxy by adding elastomer particles to existing epoxy. Generally, the toughness of elastic epoxy can be improved by changing the structure of existing epoxy of poor impact-strength. In addition, we measured the permittivity and Tan [delta] for investigation of the electrical properties of elastic epoxy. The permittivity and Tan [delta] depend on the elastomer composition. Namely, the permittivity and Tan 6 increase according to the elastomer contents. For experimental analysis results, 20 phr was considered an excellent specimen. Index Terms--Elastic epoxy, high impact, high temperature, glass transition temperature, elastic-factor.

An infinite plate weakened by doubly distributing cracks is studied in this paper. Two loading cases, the remote tension and the remote shear stresses, are assumed. Analysis is performed for a cracked cell cut from the infinite plate. It is found that the eigenfunction expansion variational method is efficient to solve the problem. The stress intensity factor, the T-stress, and the elastic response are evaluated. The cracked plate can be equivalent to an orthotropic medium without cracks. The equivalent elastic constants are presented. [DOI: 10.1115/1.1458558]

The interaction between a screw dislocation and a finite crack in an unbounded piezoelectric medium is studied in the framework of linear piezoelectric theory. A straight screw dislocation with the Burgers vector, which is normal to the isotropic basal plane, positioned around the tip of a finite crack is considered. In addition to having a discontinuous electric potential across the slip plane, the dislocation is assumed to be subjected to a line force and a line charge at the core. The explicit solution is derived by means of complex variable and conformal mapping methods. All field variables such as stress, strain, electric field, electric displacement near the crack tip, and the forces on a screw dislocation, the field intensity factors, and the energy release rate are determined under the combined out-of-plane mechanical and in-plane electrical loads. Also, the effects of screw dislocation and electrical loads are numerically analyzed. [DOI: 10.1115/1.1427692]

This paper presents summaries of the activities of six research active power engineering educators which were presented in a panel session of the same name at the IEEE Power Engineering Society Winter Meeting on February 3, 1997 in New York City. Each of the panelists discusses how research results are incorporated into courses and how students benefit from this approach. Keywords: engineering education, curriculum development

Previous studies have reported the inhibitory effect of electrical acupuncture (EAP) on basal gastric acid secretion but the mechanism of this inhibition has not been investigated. Herein, dogs were given an amino acid meal 15 minutes after the start of acupuncture. Gastric emptying and acidity were measured before and after the meal. The results revealed a reduction in gastric emptying and acidity, indicating the inhibition of gastric acid secretion. Plasma levels of somatostatin, cholecystokinin and secretin were also markedly reduced. These results suggest that inhibition by EAP occurs via the release of inhibitory hormones.

Examination of the influence of endogenous secretion of gastric acid secretion and emptying in dogs using a dye dilution technique shows that secretin acts as a physiological regulator of gastric emptying and acid output after a liquid amino acid meal. Radioimmunoassays help determine the amount of plasma secretin and gastrin, and the administration of antisecretin serum cancels the increase of plasma secretin, but increases plasma gastrin, gastric emptying and acid output. Inhibition of gastric release partly mediates the secretin-induced effects.

Examination of the action of insulin on exocrine pancreatic release in isolated, vascularly perfused rat pancreas reveals that a paracrine or local action of insulin is required for the insulin-induced exocrine pancreatic secretion. The action of insulin on pancreatic exocrine secretion also involves the influence of insulin on the secretion of endogenous antisomatostatin serum. A combined treatment of antisomatostatin serum and anti-insulin serum induce enhanced pancreatic secretion by increasing endogenous secretion in rats.

This paper develops an optimization approach using the modal performance measure for the selection of Power System Stabilizer parameters in multi-machine power systems. The goal of the optimization problem is to damp out the sustained low frequency oscillations in the outputs of a linearized power system. Thus, the modal performance measure optimization problem is to select a set of PSS parameters so that the area under the envelop of the oscillatory output response will be minimum. This paper also considers bounded and unbounded PSS parameters and compares the effects of bounds on the end results. Furthermore, this work also shows that the performance measure is not a convex function in the PSS parameters. That is, there exist many local minima and possibly a global minimum. Single-machine infinite-bus and two-machine three-bus power systems are used to show the effectiveness of the proposed work.

This paper presents a new method to solve the problem of economic power dispatch with piecewise quadratic cost function using the Hopfield neural network. Traditionally one convex cost function for each generator is assumed. However, it is more realistic to represent the cost function as a piecewise quadratic function rather than one convex function. In this study, multiple intersecting cost functions are used for each unit. Through case studies, we have shown the possibility of the application of the Hopfield neural network to the ELD problem with general nonconvex cost functions. The proposed approach is much simpler and the results are very close to those of the numerical method.

In this technical note, results are presented from a series of laboratory experiments involving the enhancement of hydraulic conductivity of clayey sands using ultrasonic excitation. An increase in hydraulic conductivity was observed in all the tests with a maximum being reached after about 8 to 10 min of excitation. Grain-size distribution analyses of the soils conducted before and after ultrasonic treatment indicated that particles smaller than 0.04 mm were mobilized by ultrasonics, and that particles in the size range of 0.04 mm to 1 mm were subjected to fracturing. Some practical implications of these results are discussed in terms of technical and economic feasibility of in situ implementation of ultrasonics.

The vibrational modes of gold film nanostructures fused on quartz substrates were investigated using picosecond ultrasonic techniques. The results showed that the nanostructures featured arrays of stripes and dots with lateral repeat distance as small as 2000 angstroms. The main damping mechanism was attributed to the effects of energy loss by elastic radiation into the substrate.

This paper describes the intelligent distributed controls research laboratory (IDCRL) in the College of Engineering at the Pennsylvania State University (PSU). The center-piece of equipment is a modern distributed microprocessor-based control system which is interfaced to real-time simulations of power plant processes. Research into implementation issues of hierarchical and distributed control for large-scale power plant systems are now more fully explored at the university level. The microprocessor-based control system has also been interfaced to the PSU TRIGA nuclear research reactor and enables research in optimal, robust, intelligent, and other advanced control techniques for nuclear power plants.

An efficient algorithm detecting the presence of a fetal QRS complex is presented. The proposed fetal QRS detection method computes the averaged magnitude of the difference between the fetal ECG signal and the reference signal to detect the fetal QRS event. The detected fetal QRS complexes are exponentially averaged to generate the template signal which can track the slowly varying shape of the fetal ECG signal. As an effort to obtain improved detection performances, two approaches of normalizing the fetal ECG signal and the template are considered.

This paper reports on the measured dielectric constants of leaves of two tropical crops, namely rubber and oil palm, as a function of moisture content at X-band. Using a microcomputer-based automated system consisting of a Wiltron scalar network analyzer and a slotted waveguide, the measurements are done based on the waveguide thin sheet technique. Theoretical values from the dual-dispersion model by Ulaby and El-Rayes [13] and from the simple dielectric theory of Fung and Fung [2] are compared with the experimental data. The model from Ulaby and El-Rayes is found to be able to give good estimates of the dielectric constants for the two types of leaf samples at X-band.

A low-temperature photoluminescence spectrum of unintentionally doped GaN in the photon energy range between 3.0 and 3.46 eV showed a series of sharp intense peaks. Most of these peaks were attributed to excitons bound to unidentified structural and surface defects.

A detailed contactless electroreflectance study of the interband excitonic transitions on both the Ga and N faces of a 200-mum-thick freestanding hydride-vapor-phase-epitaxy grown wurtzite GaN sample with low defect concentration in the temperature range of 20 and 300 K are performed. The analysis of the temperature dependence of the broadening function of excitons A and B indicate that GaN exhibits a very large exciton-phonon coupling.