Comment on "On the negative value of dielectric permittivity of the water surface layer" [Appl. Phys. Lett. 83, 4506 (2003)]

The recent interpretation of the positive resonance frequency shift in dielectric resonators loaded by water is reviewed. Instead of the invoked negative dielectric constant of water surface layer, it is demonstrated that the experimental results are fully reproduced by taking into account the dielectric losses of the sample.Comment: PDF Acrobat 4.0 file, 2 pages, 2 figures, submitted to Appl. Phys. Let

EMU Ag-Zn battery wet-life extension test

The Extravehicular Mobility Unit (EMU) silver/zinc (Ag/Zn) battery is an 11 cell battery of approximately 30 AH. The Ag/Zn battery is comprised of two 4-cell monoblocks and one 3-cell monoblock. A discussion of a wet-life extension test performed on the battery is given in viewgraph form

TanDEM-X High Resolution DEMs and Their Applications to Flow Modeling

Lava flow modeling can be a powerful tool in hazard assessments; however, the ability to produce accurate models is usually limited by a lack of high resolution, up-to-date Digital Elevation Models (DEMs). This is especially obvious in places such as Kilauea Volcano (Hawaii), where active lava flows frequently alter the terrain. In this study, we use a new technique to create high resolution DEMs on Kilauea using synthetic aperture radar (SAR) data from the TanDEM-X (TDX) satellite. We convert raw TDX SAR data into a geocoded DEM using GAMMA software [Werner et al., 2000]. This process can be completed in several hours and permits creation of updated DEMs as soon as new TDX data are available. To test the DEMs, we use the Harris and Rowland [2001] FLOWGO lava flow model combined with the Favalli et al. [2005] DOWNFLOW model to simulate the 3-15 August 2011 eruption on Kilauea\u27s East Rift Zone. Results were compared with simulations using the older, lower resolution 2000 SRTM DEM of Hawaii. Effusion rates used in the model are derived from MODIS thermal infrared satellite imagery. FLOWGO simulations using the TDX DEM produced a single flow line that matched the August 2011 flow almost perfectly, but could not recreate the entire flow field due to the relatively high DEM noise level. The issues with short model flow lengths can be resolved by filtering noise from the DEM. Model simulations using the outdated SRTM DEM produced a flow field that followed a different trajectory to that observed. Numerous lava flows have been emplaced at Kilauea since the creation of the SRTM DEM, leading the model to project flow lines in areas that have since been covered by fresh lava flows. These results show that DEMs can quickly become outdated on active volcanoes, but our new technique offers the potential to produce accurate, updated DEMs for modeling lava flow hazards

Effects of Energy-Based Therapies on Postoperative Recovery: An Integrative Review of the Literature

Associated with health care reform, there has been a growing interest among healthcare professionals regarding use of energy-based therapies as a complementary therapeutic intervention. The purpose of this integrative literature review was to examine the impact of energy-based therapies (i.e. healing touch, reiki, therapeutic touch) on patients’ postoperative recovery. The methodology included identifying appropriate peer-reviewed, English-language research articles on the topic area that were published between 2006 to 2018. Following a search in select data bases, articles focusing on the topic were critiqued, analyzed and synthesized by the researcher. Consistent and inconsistent findings along with gaps in the literature are noted. In general, the research supported positive postoperative recovery outcomes when energy-based therapies were included along with standard postoperative nursing care. This theses highlights implication for nursing practice, education, and policy and identifies study limitations. Given that research is limited on this topic area, additional studies are needed to establish supporting evidence to ascertain the effects of energy-based therapies when used as a complementary postoperative intervention

Wide-range optical studies on various single-walled carbon nanotubes: the origin of the low-energy gap

We present wide-range (3 meV - 6 eV) optical studies on freestanding transparent carbon nanotube films, made from nanotubes with different diameter distributions. In the far-infrared region, we found a low-energy gap in all samples investigated. By a detailed analysis we determined the average diameters of both the semiconducting and metallic species from the near infrared/visible features of the spectra. Having thus established the dependence of the gap value on the mean diameter, we find that the frequency of the low energy gap is increasing with increasing curvature. Our results strongly support the explanation of the low-frequency feature as arising from a curvature-induced gap instead of effective medium effects. Comparing our results with other theoretical and experimental low-energy gap values, we find that optical measurements yield a systematically lower gap than tunneling spectroscopy and DFT calculations, the difference increasing with decreasing diameter. This difference can be assigned to electron-hole interactions.Comment: 9 pages, 8 figures, to be published in Physical Review B, supplemental material attached v2: Figures 1, 7 and 8 replaced, minor changes to text; v3: Figures 3, 4 and 5 replaced, minor changes to tex

Computer simulation of low-energy excitations in amorphous silicon with voids

We use empirical molecular dynamics technique to study the low-energy vibrations in a large 4096 atom model for pure amorphous silicon and a set of models with voids of different size based on it. Numerical vibrational eigenvalues and eigenvectors for our models are obtained by exact diagonalization of their dynamical matrices. Our calculations show that localized low-energy vibrational excitations of rather complex structure are present in amorphous silicon models with voids. According to their spatial localization patterns we make an attempt to classify these excitations as modes associated with the void and "mixed" modes associated with the interaction of the void with strained regions of silicon network.Comment: Was presented at ICAMS18 conference, Snowbird UT, August 1999. Submitted to J. of Non-Cryst. Solid

Magneto-optical behaviour of EuIn_2P_2

We report results of a magneto-optical investigation of the Zintl-phase compound EuIn$_2$P$_2$. The compound orders magnetically at $T_C$=24 K and exhibits concomitant large magnetoresistance effects. For $T\le$50 K and increasing magnetic fields we observe a transfer of spectral weight in $\sigma_1(\omega)$ from energies above 1 eV into the low-energy metallic component as well as into a mid-infrared signal centered at about 600 cm$^{-1}$. This latter absorption is reminiscent to what has been seen in a large variety of so-called Kondo materials and ascribed to excitations across the hybridization gap. The observed gain of Drude weight upon increasing magnetic field suggests an enhancement of the itinerant charge-carrier concentration due to the increasing magnetization, a phenomenon that was previously observed in other compounds which exhibit colossal magnetoresistive effects.Comment: 13 pages, 4 figure

Light Quasiparticles Dominate Electronic Transport in Molecular Crystal Field-Effect Transistors

We report on an infrared spectroscopy study of mobile holes in the accumulation layer of organic field-effect transistors based on rubrene single crystals. Our data indicate that both transport and infrared properties of these transistors at room temperature are governed by light quasiparticles in molecular orbital bands with the effective masses m* comparable to free electron mass. Furthermore, the m* values inferred from our experiments are in agreement with those determined from band structure calculations. These findings reveal no evidence for prominent polaronic effects, which is at variance with the common beliefs of polaron formation in molecular solids.Comment: 4 pages, 4 figure