N-alkylthioureacadmium (II) complexes as novel precursors for the synthesis of CdS nanoparticles

The cadmium(II) complexes of thiourea and N-alkylthioureas (with alkyl group methyl or ethyl) have been used as precursors for the preparation of TOPO-capped CdS nanoparticles. The precursors are air-stable, easy to prepare and inexpensive. These compounds decompose cleanly to give good quality crystalline materials. The nanoparticles obtained showed quantum confinement effects in their optical spectra and close-to-band-edge emission in luminescence experiments. The broad diffraction patterns and the diffuse rings observed in the SAED patterns are typical of nanometric particles. The TEM images showed agglomerates of needle-like plates of particles. The presence of a strong phosphorus peak in the EDAX spectra is indicative of TOPO bound to the surface.     

A multidimensional scaling analysis of vowel discrimination in humans and monkeys

Multidimensional scaling (MDS) was used to compare perceptual maps for 10 synthetic English vowels in humans and Old World monkeys (Macaca fuscata and Cercopithecus albogularis). Subjects discriminated among the vowels using a repeating background procedure, and reaction times were submitted to an MDS analysis to derive measures of perceive similarity. The dimensions that emerged related to the frequencies of the first (F1), second (F2), and third (F3) formants. Human data indicated a good match to previous MDS studies using rating procedures or confusion matrices: The dominant dimension mapped onto vowel F2, the phonetically most important formant, and the second and third dimensions mapped onto F1 and F3, respectively. For monkeys, equal weightings occurred for F1 and F2, and F3 was not clearly represented. Monkey sensitivity to the formants appeared to relate to formant amplitudes. If monkeys are giving an accurate representation of the psychoacoustic relations among the formants, then our human results suggest that species-specific mechanisms, reflecting the salience of the phonetic feature of advancement, may contribute to vowel coding in humans.     

A clinicopathological study of infections in burn patients and importance of biopsy

Malignant peritoneal mesothelioma is a rare disease. The most frequent initial symptoms are abdominal pain, anorexia, marked weight loss and ascites. Clinical presentation as fever of unknown origin is exceptional. We report three cases diagnosed over a period of twenty years, two cases as fever of unknown origin and the third as prolonged fever. Three patients died within two months after diagnosis and prolonged fever was the clinical manifestation at the onset of the disease. It is important to take malignant peritoneal mesothelioma in the differential diagnosis of fever unknown origin.     

Surface orientation from texture: isotropy or homogeneity (or both)?

We examine two models for human perception of shape from texture, based on two assumptions about the surface texture: isotropy and homogeneity. Observers made orientation judgments on planar textured surfaces. Surface textures were either isotropic or anisotropically stretched or compressed. If subjects used an isotropy assumption, they would make biased orientation estimates for the anisotropic textures. In some conditions some observers showed no bias for the anisotropic textures relative to the isotropic textures. In general, even when the observers showed bias, the biases were significantly less than those predicted if the observer used only deviation from isotropy as a cue. Observers appear to use both the deviation from isotropy and a texture gradient or affine texture distortion cue for shape from texture.     

Developing architectural platforms: a disciplined approach

The Mescal project brings a formalized, disciplined methodology to the design of programmable platform-based systems, enabling the exploration of a wide array of architectures and a correct-by-construction path to implementation.     

A k-step predictive scheme for speed control of dieseldriven power plants

An adaptive speed control scheme for diesel prime movers is presented. Diesel prime movers are characterized by nonlinear, time-varying parameters including a nonlinear input dead-time variation that introduces an unknown delay between the injection of fuel and the production of engine torque. Such plants are difficult to control by conventional proportional-integral (PI) controllers. It is shown that by assuming the existence of an additional system time constant, an explicit estimate of the plant parameters and dead-time may be obtained. The algorithm converges rapidly. The resulting predictor can be used to set up a k-step ahead predictive controller. Studies that compare the performance of the adaptive scheme to that of a fixed, tuned, PI controller are presented. The algorithm is shown to be flexible enough to operate under a wide range of droop settings and is equally applicable to various operating conditions     

Water-Energy Nexus in Resource-poor Economies: The Indian Experience

The paper examines the nature of water-energy interactions at the level of end users in an economy where the demand for both water and energy exceeds the available supplies of these resources. The paper attempts an assessment of the nature of coping strategies adopted by individuals to deal with shortages/uncertainties/unreliability in the availability of water and energy per se and in inter-linked activities, and to provide indicative estimates of the cost of the prevailing supply scenario. The paper also examines the nature of policy interventions that could help in moving towards bridging the gap between the demand and supply of water and energy, especially in inter-linked activities. The scope of the paper is confined to the agricultural/irrigation and urban water supply sectors. Attempts at bridging the gap between demand and supply of both the resources call for both short-run and long-run solutions. A favourable policy environment, improved management of utilities, better organization and methods of existing infrastructure, metering of consumption, charging of rational tariffs for these services, larger investments in the creation of new capacities and a more active role of the private sector could to a large extent help in narrowing the gap and making the water and energy sectors more sustainable in the long run.