Computed structures of polyimides model compounds

Using a semi-empirical approach, a computer study was made of 8 model compounds of polyimides. The compounds represent subunits from which NASA Langley Research Center has successfully synthesized polymers for aerospace high performance material application, including one of the most promising, LARC-TPI polymer. Three-dimensional graphic display as well as important molecular structure data pertaining to these 8 compounds are obtained

Implantable RF-coiled chip packaging

In this paper, we present an embedded chip integration technology that utilizes silicon housings and flexible parylene radio frequency (RF) coils. As a demonstration of this technology, a flexible parylene RF coil has been integrated with an RF identification (RFID) chip. The coil has an inductance of 16 μH, with two layers of metal completely encapsulated in parylene-C. The functionality of the embedded chip is verified using an RFID reader module. Accelerated-lifetime soak testing has been performed in saline, and the results show that the silicon chip is well protected and the lifetime of our parylene-encapsulated RF coil at 37 °C is more than 20 years

Improved Semantic Representations From Tree-Structured Long Short-Term Memory Networks

Because of their superior ability to preserve sequence information over time, Long Short-Term Memory (LSTM) networks, a type of recurrent neural network with a more complex computational unit, have obtained strong results on a variety of sequence modeling tasks. The only underlying LSTM structure that has been explored so far is a linear chain. However, natural language exhibits syntactic properties that would naturally combine words to phrases. We introduce the Tree-LSTM, a generalization of LSTMs to tree-structured network topologies. Tree-LSTMs outperform all existing systems and strong LSTM baselines on two tasks: predicting the semantic relatedness of two sentences (SemEval 2014, Task 1) and sentiment classification (Stanford Sentiment Treebank).Comment: Accepted for publication at ACL 201

Environmental effects of the Manganui ski field, Mt Taranaki/Egmont

During May 2012, the environmental effects of the Manganui ski field were examined. Permanent quadrats first established in 1974 to monitor vegetation changes were re-measured, vegetation mapping was conducted, modifications to ground form and drainage were identified, soil compaction was examined, and stream water from the ski field catchment was tested for nutrient enrichment. This report focusses primarily on the lower Manganui ski field, as the upper Manganui ski field consists mostly of unmodified herbfield or gravelfield, protected by a sufficient snow base over the winter months. The lower Manganui ski field has a long history of modification spanning from the early 1900s. Vegetation types mapped on the lower field included unmown tussockfield, mown tussock-herbfield, shrubland and exotics. The re-measurement of vegetation in permanent quadrats on the lower field suggests that since the last re-measurement in 1994, several exotic species have increased in cover, including Carex ovalis, Poa annua, and Agrostis capillaris (percentage cover increases of up to 46.6%, 42.0% and 20.7% respectively). Vegetation mapping and historic photographs indicate that the lower ski field sits within the elevational belt of shrubland vegetation, little of which remains due to regular mowing conducted on the field since 1947. Shrubs which have been largely excluded from the field through mowing include Brachyglottis elaeagnifolius, Hebe odora, Ozothamnus vauvilliersii, Dracophyllum filifolium, Pseudopanax colensoi, Raukaua simplex and Hebe stricta var. egmontiana. Areas of the ski field dominated by exotic vegetation were predominantly associated with historic culvert construction and rock dynamiting. Compaction by machinery was confined to the sensitive mossfield area at the base of the lower field

Complete gradient-LC-ESI system on a chip for protein analysis

This paper presents the first fully integrated gradient-elution liquid chromatography-electrospray ionization (LC-ESI) system on a chip. This chip integrates a pair of high-pressure gradient pumps, a sample injection pump, a passive mixer, a packed separation column, and an ESI nozzle. We also present the successful on-chip separation of protein digests by reverse phase (RP)-LC coupled with on-line mass spectrometer (MS) analysis

Was the Federal Reserve Fettered? Devaluation Expectations in the 1932 Monetary Expansion

A key question about the Great Depression is whether expansionary monetary policy in the United States would have led to a loss of confidence in the U. S. commitment to the gold standard. This paper uses the $1 billion expansionary open market operation undertaken in the spring of 1932 as a crucial case study of the link between monetary expansion and expectations of devaluation. Data on forward exchange rates are used to measure expectations of devaluation during this episode. We find little evidence that the large monetary expansion led investors to believe that the United States would devalue. The financial press and the records of the Federal Reserve also show little evidence of expectations of devaluation or fear of a speculative attack. We find that a flawed model of the effects of monetary policy and conflict among the twelve Federal Reserve banks, rather than concern about the gold standard, led the Federal Reserve to suspend the expansionary policy in the summer of 1932.

Spinon-Holon binding in t−Jt-J model

Using a phenomenological model, we discuss the consequences of spinon-holon binding in the U(1) slave-boson approach to $t-J$ model. Within a small $x$ ($x=$ hole concentration) expansion, we show that spinon-holon binding produces a pseudo-gap normal state with a segmented Fermi surface and the superconducting state is formed by opening an "additional" d-wave gap on the segmented Fermi surface. The d-wave gap merge with the pseudo-gap smoothly as temperature $T\to0$. The quasi-particles in the superconducting state are coupled to external electromagnetic field with a coupling constant of order $x^{\gamma}$ where $0\leq\gamma\leq1/2$, depending on the strength of the effective spinon-holon binding potential.Comment: 9 pages, 3 figure

RESTAURANT AND SUPERMARKET LOBSTER PRICE PERCEPTIONS, RESPONSES, AND STRATEGIES

Consumer/Household Economics, Demand and Price Analysis,

Vegetation dieback as a proxy for temperature within a wet pyroclastic density current: A novel experiment and observations from the 6th of August 2012 Tongariro eruption

The 6th of August 2012 eruption of Te Maari (Mt Tongariro, New Zealand) generated wet pyroclastic density currents (PDCs) which caused widespread dieback of vegetation (singed, brown foliage) in their path. An absence of significant charcoal formation suggests that PDC temperatures were mostly below 250 °C. Textural evidence for liquid water being present in the matrices during emplacement (vesicles) suggests that temperatures were b100 °C. We determined a probable minimum PDC temperature using an experiment replicating the critical temperatures required to induce foliar browning in seven species affected by the eruption. In locations where all species exhibited browned foliage (or were defoliated), temperatures were probably ≥64 °C assuming a PDC duration of 60 s. In the more distal areas, where only the most susceptible species were browned while others remained healthy and unaffected, temperatures were probably around 51–58 °C. These results have relevance to volcanic hazard mitigation and risk assessment, especially on the popular Tongariro Alpine Crossing

An upper bound on the total inelastic cross-section as a function of the total cross-section

Recently Andr\'e Martin has proved a rigorous upper bound on the inelastic cross-section $\sigma_{inel}$ at high energy which is one-fourth of the known Froissart-Martin-Lukaszuk upper bound on $\sigma_{tot}$. Here we obtain an upper bound on $\sigma_{inel}$ in terms of $\sigma_{tot}$ and show that the Martin bound on $\sigma_{inel}$ is improved significantly with this added information.Comment: 4 page