Synthesis of RE（OH）2Cl and REOCI （RE=Eu,Tb） nanostructures

Anisotropic structures, nanoneedles, and nanospindles of rare earth hydroxychloride （RE（OH）2Cl） and oxychloride （REOCl） （rare earth=Eu and Tb） were synthesized. The rare earth hydroxychloride nanostructures were formed via a thermally assisted hydrolysis of the rare-earth sesquioxide nanocrystals. The morphological evolution of the nanostructures was studied using high-resolution transmission electron microscopy and scanning electron microscopy, while the structural evolution was investigated using X-ray diffraction techniques. The thermal stability of the rare earth hydroxychlorides was investigated using thermogravimetric analysis. The rare earth oxychloride nanospindles were synthesized via a simple heat-treatment of rare earth hydroxychloride nanospindles.     

An automatic self-installation and calibration method for a 3D position sensing system using ultrasonics

This work addresses 3D position sensing systems that estimate the location of a wave source by triangulating its position based on the time-of-flights (TOFs) to various receivers fixed to an inertial frame of reference. Typical applications of such systems are finding the location of the transmitter that may be fixed to an autonomously guided vehicle (AGV) operating in an enclosed work environment, a robot end-effector, or virtual reality environments. These environments constitute a large working volume, and the receivers have to be fixed in this environment and their locations known exactly. This is a major source of problems in the installation/calibration stage since the receivers are usually distributed in space and finding their exact location entails using a separate 3D calibrating device which may or may not be as accurate as the location system itself. This paper presents a method to use the system itself to set up an inertial frame of reference and find out the locations of the receivers within this frame by simply using an accurate ID positioning system, e.g. an accurate ruler or a simple distance measuring system that uses ultrasonic or infrared sensors. The method entails moving the transmitter to known locations on a single plane, and using the TOFs to estimate the location of the receivers. A typical application would be that an AGV carries a set of receivers to a hazardous environment such as a nuclear power plant, places the receivers arbitrarily, carries out the self-installation/calibration procedure, maps out the environment, and begins to function autonomously, the whole procedure being done without human intervention or supervision.     

The effect of stabilization on the onset of neuromuscular block when assessed using accelerometry

Accelerometry is increasingly being used for neuromuscular monitoring. We sought to determine whether this system is sensitive to the period of stabilization of muscle twitch prior to the administration of neuromuscular relaxant. We recruited 20 patients. No premedication was given, and anesthesia was induced with propofol and alfentanil and maintained by a propofol infusion. An accelerometer was attached to each wrist. One of the ulnar nerves was stimulated for 20 min and the other for 3 min using a train-of-four pattern at 15-s intervals. Ten patients then received vecuronium 0.1 mg/kg and a subsequent 10 received atracurium 0.5 mg/kg. The time to onset of maximum block was recorded. The data collected was subjected to a paired t-test with P < 0.05 taken as significant. The mean onset times for patients who received vecuronium was 148.5s for the arms stabilized for 3 min and 151.5s for the arms stabilized for 20 min, and in those who received atracurium it was 138.0s and 130.5s, respectively. We conclude that there is no significant difference in the onset of neuromuscular block with either vecuronium or atracurium after stabilization periods of 3 or 20 min when assessed by accelerometry.     

Heating and cooling potential of an underground air-pipe system

The annual heating and cooling potential of an underground air-pipe system has been evaluated in terms of dimensionless parameters of the system. The effect of diurnal and annual variations of environmental parameters (solar radiation, ambient temperature and relative humidity) has been considered. The results are obtained for hot—dry, cold—dry and composite climatic conditions typified by the Jodhpur, Leh and Delhi climates respectively. The effect of suitable earth surface treatments on the thermal performances of the air-pipe system has also been analysed. For wet—shaded earth surface the cooling potential of a pipe of length 50 m and radius 10 cm at a depth 6 m in Jodhpur climate is found to be 4472 kW h, while for the Leh climate under glazed and blackened earth surface conditions the heating potential of such an air-pipe system is found to be 9097 kW h.     

Toxicity of aflatoxin B1 in broiler chicks and its reduction by activated charcoal

Lipoprotein (a) (Lp(a)) is a plasma lipoprotein of high atherogenicity and competes with plasminogen at the site of plasminogen receptors. It is known that diabetic patients show a hypercoagulable state which might contribute to diabetic vascular complications. In the present study, mean levels of plasma Lp(a) and parameters of coagulation and fibrinolysis such as thrombin-antithrombin III complex (TAT) and alpha 2 plasmin inhibitor-plasmin complex (alpha 2PIC) were elevated in diabetic patients with nephropathy compared to healthy controls. A significant positive correlation was observed between the plasma levels of Lp(a) and alpha 2PIC (p < 0.05). Plasma levels of alpha 2PIC showed a significant positive correlation with those of TAT in the diabetic group, while there was no significant correlation observed in the non-diabetic group. The present results suggest that factors of Lp(a) and coagulation-fibrinolytic systems interacted, contributing to vascular complications in diabetic patients with nephropathy.     

Differential scanning calorimetry studies on coal. 2. Hydrogenation of coals

Results of exothermic heats involved during hydrogenation of twenty U.S. raw coals of varying rank at 5 · 6 MPa (gauge) and temperatures up to 570 °C are reported. The heat evolved during hydrogenation up to 570 °C decreases with increase in coal rank. A part of the total heat released during hydrogenation of coals appears to be due to the exothermic reaction between H₂ and surface carbon-oxygen complexes removed during the reaction. The transition temperature, that is the temperature corresponding to the onset of exotherms, is markedly dependent on coal rank. A sharp increase in the transition temperature occurs for coals having a carbon content, on a dry-ash-free basis, in the 75–80% range. Demineralization of coals lower in rank than HVA bituminous decreases the heat of hydrogenation; in the case of higher-rank coals, exothermic heats increase upon demineralization. The presence of pyrite has a beneficial catalytic effect on coal hydrogenation.     

Mapping metal catalysts using synchrotron computed microtomography (CMT) and micro-X-ray fluorescence (μXRF)

Gas-to-liquids (GTL) is a viable pathway to synthesize clean fuels from natural gas. The continuing technological advances in natural gas conversion technology have led several companies to make investment in the Fischer–Tropsch (F–T) route to synthesize clean hydrocarbon fuels. But, a highly efficient gas conversion process to capitalize on remote natural gas fields still remains elusive. Heterogeneous catalyst assemblies are typically utilized in the GTL conversion reactions but an in-depth characterization of catalytic materials is needed to design the next-generation more efficient catalysts. Computed microtomography (CMT) and micro-X-ray fluorescence (XRF), techniques at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), are complementary methods that allow mapping of catalyst constituents. We describe here the experimental apparatus and give examples of utilization of these techniques in catalyst characterization in different processes. The potential of using CMT and XRF techniques for monitoring changes in the catalyst composition during F–T synthesis are discussed and an example based on the use of X-ray fluorescence imaging is presented.