Catalysts for polyimide foams from aromatic isocyanates and aromatic dianhydrides

Polyimide foam products having greatly improved burn-through and flame-spread resistance are prepared by the reaction of aromatic polyisocyanates with aromatic dianhydrides in the presence of metallic salts of octoic acid. The salts, for example stannous octoate, ferric octoate and aluminum octoate, favor the formation of imide linkages at the expense of other possible reactions

. The Effect of Ethical Leadership on the Work Performance of Employees

The study aimed to determine the effect of ethical leadership on the individual work performance of employees. To deepen the concept of the study and establish theories of the study, literature was reviewed. The study used a descriptive assessment and correlational research design. The population of the study was all the employees of the Divine Word College of Laoag and the data were gathered through research questionnaires. To analyze the data, the weighted mean and Pearson r correlation was used. The results suggest that ethical leadership is significantly correlated with the task performance and counterproductive work behavior and no correlation with the contextual performance

How do Fermi liquids get heavy and die?

We discuss non-Fermi liquid and quantum critical behavior in heavy fermion materials, focussing on the mechanism by which the electron mass appears to diverge at the quantum critical point. We ask whether the basic mechanism for the transformation involves electron diffraction off a quantum critical spin density wave, or whether a break-down in the composite nature of the heavy electron takes place at the quantum critical point. We show that the Hall constant changes continously in the first scenario, but may ``jump'' discontinuously at a quantum critical point where the composite character of the electron quasiparticles changes.Comment: Revised version with many new references added. To appear as a topical review in Journal of Physics: Condensed Matter Physics. Two column version http://www.physics.rutgers.edu/~coleman/online/questions.ps.g

8.2 ka event North Sea hydrography determined by bivalve shell stable isotope geochemistry

This is the final version. Available on open access from Nature Research via the DOI in this recordThe abrupt 8.2 ka cold event has been widely described from Greenland and North Atlantic records. However, its expression in shelf seas is poorly documented, and the temporal resolution of most marine records is inadequate to precisely determine the chronology of major events. A robust hydrographical reconstruction can provide an insight on climatic reaction times to perturbations to the Atlantic Meridional Overturning Circulation. Here we present an annually-resolved temperature and water column stratification reconstruction based on stable isotope geochemistry of Arctica islandica shells from the Fladen Ground (northern North Sea) temporally coherent with Greenland ice core records. Our age model is based on a growth increment chronology obtained from four radiometrically-dated shells covering the 8290–8100 cal BP interval. Our results indicate that a sudden sea level rise (SSLR) event-driven column stratification occurred between ages 8320–8220 cal BP. Thirty years later, cold conditions inhibited water column stratification but an eventual incursion of sub-Arctic waters into the North Sea re-established density-driven stratification. The water temperatures reached their minimum of ~3.7 °C 55 years after the SSLR. Intermittently-mixed conditions were later established when the sub-Arctic waters receded.Natural Environment Research Council (NERC)European Union FP

Simultaneous Embeddings with Few Bends and Crossings

A simultaneous embedding with fixed edges (SEFE) of two planar graphs $R$ and $B$ is a pair of plane drawings of $R$ and $B$ that coincide when restricted to the common vertices and edges of $R$ and $B$. We show that whenever $R$ and $B$ admit a SEFE, they also admit a SEFE in which every edge is a polygonal curve with few bends and every pair of edges has few crossings. Specifically: (1) if $R$ and $B$ are trees then one bend per edge and four crossings per edge pair suffice (and one bend per edge is sometimes necessary), (2) if $R$ is a planar graph and $B$ is a tree then six bends per edge and eight crossings per edge pair suffice, and (3) if $R$ and $B$ are planar graphs then six bends per edge and sixteen crossings per edge pair suffice. Our results improve on a paper by Grilli et al. (GD'14), which proves that nine bends per edge suffice, and on a paper by Chan et al. (GD'14), which proves that twenty-four crossings per edge pair suffice.Comment: Full version of the paper "Simultaneous Embeddings with Few Bends and Crossings" accepted at GD '1

Theories of non-Fermi liquid behavior in heavy fermions

I review our incomplete understanding of non-Fermi liquid behavior in heavy fermion systems at a quantum critical point. General considerations suggest that critical antiferromagnetic fluctuations do not destroy the Fermi surface by scattering the heavy electrons- but by actually breaking up the internal structure of the heavy fermion. I contrast the weak, and strong-coupling view of the quantum phase transition, emphasizing puzzles and questions that recent experiments raise.Comment: Overview talk, SCES Paris 1998. References to Sachdev and Ye adde

The death of gold in early Visayan societies

There is a scanty amount of literature about gold of Philippine societies in the last one thousand years. Much of what we know about the people’s use of the metal comes from ethnographic and ethnohistoric sources. More so, the literature becomes even scantier when we delve deeper into how early Filipinos viewed their use of gold. Hence, the paper tries to survey vast sources of information in order to elucidate the reasons behind the apparent use of gold in death and burial practices of the early inhabitants of the Philippine archipelago, especially of the early Visayan societies. Indeed, burial sites comprise most of the archaeological sources in the area; thus, the study also concerns itself with how mortuary analyses through archaeological methodologies and inferences, could provide concrete evidences for these accounts. Focusing on the early Filipinos’ concepts of death, dying and the afterlife, the paper argues that gold, as a distinct material, is deemed important in this stage of people’s life. The paper introduces the concept of object-soul, an animist explanation why certain materials were buried together with the dead. However, beyond the consideration of nature spirits in such perspective, the study argues that material objects in Visayan death and burial, like gold, were conceived as having soul, thus undergo the same separation and transition that happens to the deceased. Not with standing that there were prevailing justifications on the use of gold in death and burial during the protohistoric period in the Philippines, and that this deliberate use was predominantly attributed to consensual spiritualism, the persevering question of why is there a limited archaeological evidence of gold in burials still posits a problem a problem