Effect of acid dissolution on the mineral matrix and organic matter of Zefa EFE oil shale

Kerogen of the Israeli Zefa oil shale was isolated and the changes which occur in the initial organic matter during the removal of the inorganic matrix were investigated. Benzene-methanol extraction dissolved the bitumens, hydrochloric acid and hydrofluoric acid dissolution removed the carbonate and silicate minerals and lithium aluminium hydride treatment destroyed pyrite mineral which was unaffected by the attack of acids. X-ray diffractograms and FTIR spectra of the original oil shale and its demineralized products were measured. Benzene-methanol extraction of the oil shale increased the resolution of peaks in the X-ray diffractograms X-ray diffractograms and FTIR spectra indicated the presence of calcite, α-quartz, kaolinite, illite and pyrite in the mineral matrix of the shale. Hydrochloric and hydrofluoric acid dissolution did not cause hydrolysis and oxidation of the organic matter. Lithium aluminium hydride treatment reduced the carbonyl functionalities to newly formed hydroxyl groups, therefore the kerogen isolated seemed to have a chemical composition different from that of the original oil shale.     

Coscheduling based on runtime identification of activity working sets

This paper introduces a method for runtime identification of sets of interacting activities (“working sets”) with the purpose ofcoscheduling them, i.e., scheduling them so that all the activities in the set execute simultaneously on distinct processors. The identification is done by monitoring access rates to shared communication objects: activities that access the same objects at a high rate thereby interact frequently, and therefore would benefit from coscheduling. Simulation results show that coscheduling with our runtime identification scheme can give better performance than uncoordinated scheduling based on a single global activity queue. The finer-grained the interactions among the activities in a working set, the better the performance differential. Moreover, coscheduling based on automatic runtime identification achieves about the same performance as coscheduling based on manual identification of working sets by the programmer.     

Fiberoptic circuit network design under reliability constraints

A general mathematical model for a network design problem with reliability constraints and a revised formulation which seems particularly appropriate for fiber-optics networks is presented. Upper and lower bounding procedures based on continuous relaxations of this modified formulation are described. Preliminary computational results are reported. Limited computational results indicate a good performance of the algorithm, producing a gap between lower and upper bounds that is sufficiently small for a branch-and-bound procedure to be applicable     

Experience with using the Parallel Workloads Archive

Science is based upon observation. The scientific study of complex computer systems should therefore be based on observation of how they are used in practice, as opposed to how they are assumed to be used or how they were designed to be used. In particular, detailed workload logs from real computer systems are invaluable for research on performance evaluation and for designing new systems.     

Thermally-Induced Changes in Bonding Properties of C60 on Si(100)-2×1 Surfaces

The co-adsorption of pre- and post-annealed C₆₀ molecules on Si(100)-2×1 surfaces has been investigated using scanning tunneling microscopy in ultrahigh vacuum. The images reveal that the adsorption characteristics of the post-annealed adsorbates are different from their pre-annealed counterparts. The post-annealed C₆₀ molecules bond either to the top of the dimer rows or to the missing dimer defects, while the pre-annealed molecules predominantly occupy the four-dimer sites in the troughs. The apparent size and height of post-annealed C₆₀ molecules are smaller than those of the pre-annealed ones. Our observations suggest that the post-annealed C₆₀ molecules are chemisorbed on the surface, because the molecules covalently bond to Si atoms during the sample annealing. In contrast, the adsorption of the pre-annealed C₆₀ molecules can be explained by a dipole-induced-dipole interaction between the molecules and the Si(100) surface, i.e., physisorption.     

How programmers read regular code: a controlled experiment using eye tracking

Regular code, which includes repetitions of the same basic pattern, has been shown to have an effect on code comprehension: a regular function can be just as easy to comprehend as a non-regular one with the same functionality, despite being significantly longer and including more control constructs. It has been speculated that this effect is due to leveraging the understanding of the first instances to ease the understanding of repeated instances of the pattern. To verify and quantify this effect, we use eye tracking to measure the time and effort spent reading and understanding regular code. The experimental subjects were 18 students and 2 faculty members. The results are that time and effort invested in the initial code segments are indeed much larger than those spent on the later ones, and the decay in effort can be modeled by an exponential model. This shows that syntactic code complexity metrics (such as LOC and MCC) need to be made context-sensitive, e.g. by giving reduced weight to repeated segments according to their place in the sequence. However, it is not the case that repeated code segments are actually read more and more quickly. Rather, initial code segments receive more focus and are looked at more times, while later ones may be only skimmed. Further, a few recurring reading patterns have been identified, which together indicate that in general code reading is far from being purely linear, and exhibits significant variability across experimental subjects.     

WORDS AS CLASSIFIERS OF DOCUMENTS ACCORDING TO THEIR HISTORICAL PERIOD AND THE ETHNIC ORIGIN OF THEIR AUTHORS

The mere presence of information does not insure that it is understood. The information has to be processed in order that information could be used to perform work. In this report, the concept of “processing potential” has been presented. The term “knowledge” has been introduced as the processing potential. Using the concept of the processing potential, a specific relationship between knowledge and the dissipation function is proposed. The formulation suggested here is consistent with the formulations used Tor other physical phenomenon.     

Interorganizational transfer of knowledge: an analysis of patentcitations of a defense firm

It is argued that although technology is considered to be a strategic asset for an organization, interplay in technology among organizations is necessary. Technology may be considered a bank which organizations both contribute to and draw from. Such interactions among organizations in technology follow different patterns. Some preliminary results from a study that aims at addressing this issue are presented. Using patent-citation data, it is shown that the benefits to participating firms change with industry type, organization class, and country of origin