Performance enhancement of ammonia-fueled engine by using dissociation catalyst for hydrogen generation

The effect of combustion of hydrogen generated by an ammonia dissociation catalyst on engine performance and exhaust emissions in a spark-ignition engine using ammonia-gasoline was investigated. An ammonia dissociation catalyst coated with 2% ruthenium on 3.175-mm alumina pellets were used in order to analyze the effect of the catalyst as an ammonia cracker to decompose ammonia into hydrogen and nitrogen. Results show that combustion of hydrogen generated by an ammonia dissociation catalyst resulted in improved engine performance and reduced exhaust emissions. The conversion rate of ammonia into hydrogen was affected by the flow rate of ammonia, and the catalyst was very effective at low to medium flow rates, resulting in significantly increased engine power and decreased fuel consumption. With the use of the catalyst, emissions of CO, HC, NH₃ and NOx were reduced considerably. Overall, it was demonstrated the ammonia dissociation catalyst can enable ammonia to be used as a hydrogen carrier for use in internal combustion engines effectively.     

Solution-processable graphene linked to 3,5-dinitrobenzoyl as an electron acceptor in organic bulk heterojunction photovoltaic devices

3,5-Dinitrobenzoyl chloride was covalently linked to graphene oxide (GO) nanosheets prepared by a modified Hummers’ method, using ethylenediamine as a spacer. The linkage of the GO with the small molecule was confirmed by spectroscopic (e.g., Fourier transform infrared, Raman) and microscopic analyses. The resultant GO-ethylene-dinitro-benzoyl (GO-EDNB) consists of a controlled scale of different graphene structures and is highly dispersable in common organic solvents. The GO-EDNB was used as the electron acceptor material in poly-(3-hexylthiophene) (P3HT) bulk heterojunction photovoltaic devices to significantly improve the performance, yielding a power conversion efficiency improvement of two orders and one order of magnitude compared with the pristine P3HT and the P3HT-GO devices respectively.     

Vascularized bone flaps versus nonvascularized bone grafts for mandibular reconstruction: an outcome analysis of primary bony union and endosseous implant success

We present a patient with a lesion of the mesial frontal cortex, including the supplementary motor areas bilaterally, who on clinical examination revealed no spontaneous movements, although neurophysiological examination indicated integrity of the corticospinal tract to thenar and tibialis anterior muscles bilaterally. The patient was alert, speech was hesitant, and he was able to move his hands only on command. The role of the supplementary motor areas in planning, setting, and execution of skillful voluntary movements has been previously established by direct cortical electrical stimulation and studies of regional cerebral blood flow. The findings in our patient support the role of the supplementary motor areas in initiating movements. The presence of motor evoked potentials after acute insults to the brain is considered to be associated with a good functional outcome. This is in contrast to our patient who did not show improvement in motor performance, despite preserved motor evoked potentials. Hence, in the case of bilateral lesions to the supplementary motor areas sparing the corticospinal tract, the presence of motor evoked potentials may not predict functional recovery.     

Reduced state correlations of the enskog modulus for gases and liquids

The Enskog modulus, bρ x, has been subjected to a generalized treatment to develop reduced state correlations for nonpolar and polar substances that exhibit hydrogen bonding. These correlations present relationships between 1 + bρx and ρ_R, the reduced density. For nonpolar substances, the PVT data of argon, nitrogen, methane, ethane, and carbon dioxide were used for the development of these relationships, which were found to depend on z_c, the critical compressibility factor. PVT data for ammonia, methyl alcohol, and water yielded a different correlation, which is applicable to polar substances which exhibit hydrogen bonding. These relationships were found to depend on the parameter, β = (T_b-T_m)/M, which quantitatively describes the extent of hydrogen bonding for polar compounds.     

Effect of Surface Electrode Number on Estimates of Cardiac Dipole Moment

This study reports on the errors in the calculation of a heart dipole introduced by deleting individual electrode contributions to a surface potential map. The potential at 150 points on each of 6 normal children was available at several instants of the QRS cycle. Although it was impossible to test all possible sets of deleted points, or all possible methods of compensatory weighting of the residual points, the results indicate that a number of electrodes at least as great as 100 is required to produce consistent relative errors of less than 15 percent, if surface potential integration is employed in determining the heart's total dipole moment.     

Antidepressant drugs appear to enhance cocaine-induced toxicity.

It has been shown that cocaine-induced convulsions and lethality appear to be mediated by serotonin and dopamine neurotransmission, respectively. However, many antidepressants considered for treatment of cocaine addiction target these monoamine systems and may thus amplify these toxic effects during relapse. In this study, the authors assessed whether pretreatment with antidepressants influences cocaine-induced toxicity in mice as well as the potency of these medications at cocaine-binding sites previously shown to be associated with cocaine toxicity. Overall, selective serotonin reuptake inhibitors (SSRIs) facilitated cocaine-induced convulsions but not lethality. Dopamine uptake inhibition facilitated cocaine-induced lethality, but not convulsion. The SSRI sertraline enhanced neither convulsions nor lethality and may be unique due to its high affinity for sigma receptors. These results have important implications for safe and effective addiction treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reliability of RF MEMS switches due to charging effects and their circuital modelling

The reliability of RF MEMS switches is typically reduced by charging effects occurring in the dielectrics. The aim of this paper is to discuss these effects, and to propose analytical and equivalent circuit models which account for most of the physical contributions present in the structure.     

A Classical MCMC Approach to the Estimation of Limited Dependent Variable Models of Time Series

Estimating limited dependent variable time series models through standard extremum methods can be a daunting computational task because of the need for integration of high order multiple integrals and/or numerical optimization of difficult objective functions. This paper proposes a classical Markov Chain Monte Carlo (MCMC) estimation technique with data augmentation that overcomes both of these problems. The asymptotic properties of the proposed estimator are discussed. Furthermore, a practical and flexible algorithmic framework for this class of models is proposed and is illustrated using simulated data, thus also offering some insight into the small-sample biases of such estimators. Finally, the proposed framework is used to estimate a dynamic, discrete-choice monetary policy reaction function for the United States during the Greenspan years.