Boundary Lubricated Tribology of an Aluminium-Silicon Alloy Sliding Against Steel

We have slid steel pins on aluminium-silicon alloy discs in the boundary lubrication regime in the presence of one drop of oil. We have explored the effect of base oil and additivated engine oil on friction and wear and analyzed the data in terms of the formation of a mechanically mixed layer at the interface and the corrosive action of additive addition.     

Urban air quality in the Asian region

Over the past decade, member states of the Regional Co-operation Agreement (RCA), an intergovernmental agreement for the East Asia and Pacific region under the auspices of the IAEA with the assistance of international organizations and financial institutions such as the World Bank and the Asian Development Bank, have started to set in place policies and legislation for air pollution abatement. To support planning and evaluate the effectiveness of control programs, data are needed that characterizes urban air quality. The focus of this measurement program describe in this report is on size segregated particulate air pollution. Such airborne particulate matter can have a significant impact on human health and urban visibility. These data provide the input to receptor models that may permit the mitigation of these impacts by identification and quantitative apportionment of the particle sources. The aim of this report is to provide an overview of the measurements of concentrations and composition of particulate air pollution in two size fractions across the participating countries. For many of the large cities in this region, the measured particulate matter concentrations are greater than air quality standards or guidelines that have been adopted in developed countries.     

Comments on "On Determining Cluster Size of Randomly Deployed Heterogeneous WSNs"

See ibid., vol.12, no.4, p.232-4 (2008) by Sevgi and Kocyigit. This comment points out one inaccurate equation and one erroneous figure. The correct equation and figure are provided.     

Microbial uptake of diesel oil sorbed on soil and oil spill clean‐up sorbents

Sorbent effects in the microbial uptake of diesel oil were determined for black cotton soil (BCS) and two oil spill clean‐up sorbents, ie peat sorb and spill sorb. Biodegradation studies were conducted in mass transfer limited batch slurry microcosms using microorganisms capable of direct interfacial uptake of diesel oil. Under identical loading conditions, the amounts of diesel oil initially loaded on the various sorbents were 178, 288 and 649 mg g^?1 for BCS, spill sorb and peat sorb, respectively. Total biodegradation of sorbed diesel was comparable for all the sorbents (45–52 mg), however, the biodegradation rates were significantly different. Peat sorb demonstrated a distinct initial lag phase, the biodegradation rate in spill sorb was initially slower, whereas biodegradation at a high rate commenced immediately for BCS. The maximum biodegradation rates observed for BCS, spill sorb and peat sorb microcosms were 7.9, 5, and 2.9 mg day^?1, respectively. Thus, the maximum biodegradation rate increased as the diesel oil loading decreased. Our results indicate that spill clean‐up sorbents have greater bioavailability limitations compared with soils and this is linked with their significantly higher loading capacity and internal porosity. Copyright © 2005 Society of Chemical Industry     

Creep Behavior of Metal Fiber-PPE Composites and Effect of Test Surroundings

The effect of environment on creep behavior of Poly-Phenylene Ether (PPE) composites with stainless steel fiber was investigated in this research. The results of creep behavior of PPE composites, carried out both in air and oil surroundings at elevated temperatures, show very good agreement with the Arrhenius reciprocation law of time-temperature. It was, however, observed that there was comparatively greater departure from good superposition in the creep compliance curve for oil surroundings in long period creep. The minute changes in activation energy for creep phenomena in different surroundings were observed. The effect of fiber volume fraction on creep behavior was also studied. In addition, a brief investigation of the effect of physical aging was done, with the results clearly showing that smoothness in the creep compliance master curve depends on the degree of physical aging of the matrix resin.     

A novel scheme for reception using an active microstrip antenna

An unique aspect of the injection-locked active microstrip antenna incorporating a Gunn diode, i.e., the variation of the device current within the lock band, is exploited for the demodulation of an FM microwave signal. A simple experimental arrangement has been presented to demonstrate the demodulation performance of the receiver even in a multichannel environment. Using two such separate antennas as transmitter and receiver, a two-way short-range communication system has been demonstrated that may be suited for certain commercial and military applications     

Association of DOA Estimation From Two ULAs

In this paper, we consider the problem of associating estimated direction-of-arrival (DOA) angles of multiple targets using two uniform linear arrays (ULAs) of sensors. It is categorized as a multisource information aggregation problem, in which we devise our algorithm in the following two steps: (1) Estimate two sets of DOA angles from two ULAs, respectively, and (2) associate estimated DOA angles with the targets. Note, however, that the primary focus of this paper is the second step, i.e., association of DOA angles with the corresponding targets, whereas for the first step, we use the well-known improved polynomial rooting method. Generally speaking, if there are q targets, we have q! possible association pairs, among which, there is only one set corresponding to the correct association. Since target signals must be correlated in the observations of two ULAs, we can determine how to associate the DOA angles computed from step 1 by evaluating the covariance matrix of the data received at the two ULAs. The algorithm is effective, robust, and accurate in classifying the DOA angles into the correct association.     

A water‐dispersible conducting nanocomposite from suspension polymerisation of thiophene in presence of N‐vinylcarbazole

The polymerisation of a mixture of thiophene and N‐vinylcarbazole was achieved in aqueous suspension in the presence of nanodimensional alumina and FeCl₃ as oxidant. The resultant composite was found to contain both polythiophene (PTP) and poly(N‐vinylcarbazole) (PNVC) components even after reflux in benzene, which would remove any PNVC homopolymer. The presence of the individual polymer components was endorsed by FTIR spectroscopic analyses. Thermogravimetric analyses showed that the overall stabilities of the composite and the corresponding homopolymers were in the order: PTP–Al₂O₃ > PTP > PTP–PNVC–Al₂O₃ > PNVC. Differential thermal analyses studies showed the manifestation of two different exotherms corresponding to the presence of two different polymeric constituents in the PTP–PNVC–Al₂O₃ composite. Differential scanning calorimetry studies revealed two glass‐transition temperatures (T_g) suggesting the presence of two polymeric moieties in the PTP–PNVC composite. Scanning electron micrographs of the PTP–Al₂O₃ and PTP–PNVC–Al₂O₃ composites showed distinctive morphological patterns. Transmission electron microscopic images of the composite revealed that the average particle size varied between 20 and 80 nm. DC conductivities of the composites were of the order of 10^?6 S cm^?1. Copyright © 2003 Society of Chemical Industry     

USCSH: An Active Intelligent Assistance System

This paper describes the knowledge sources and methods of knowledge acquisition for USCSH (University of South Carolina SHell). USCSH is an active intelligent assistance system for Unix. The system operates in two modes, the active mode and the intelligent mode. In the active mode USCSH monitors the user's interactions with the system, and at appropriate times makes suggestions on how the user may better utilize the system to perform tasks. In the intelligent mode the system accepts questions in natural language and responds to them, taking into consideration the ability of the user and the context of the question.     

A model to predict climate-change impact on fish catch in the world oceans

Water temperature plays a very important role in fish production. The assessment of the impact of water-temperature changes on fish catches in world fishery is essential for the sustainable management of world fishery resources. Fish catch includes different species, but using information analysis, it is shown that total fish catch can be used without significant loss of information about the dynamic properties of the system. A new method for the forecasting of the fish catch of the major fishing areas in the world's oceans under global climate change (temperature) has been developed. This method predicts the tendency (increase or decrease) for fish catch, with quantitative predictor's power, if the temperature is known. This method has been applied to the Indian Ocean to assess the climate-change impact on fish catch. Based on the temperatures predicted using the CLIMate-BiospheRE model for the years 2000-2100, a decrease of fish catch in the Indian Ocean, with the confidence of the predictor's power at /spl ges/ 90%, has been predicted.