Miracle-dz/UniFAR-FTUs huggingface dataset:
Improvement in C-V characteristics of Ge metal-oxide semiconductor capacitor by H2O2 incorporated HCl pretreatment

Electrical characteristics of high-κ∕Ge metal-oxide semiconductor (MOS) capacitors pretreated with HCl or HF solutions are investigated, including the effect of H2O2 incorporation. HCl treatment is more effective than HF treatment for decreasing equivalent oxide thickness. H2O2 incorporation into HCl solution leads to dramatic decrease in the capacitance at inversion side. We have confirmed that residual metal impurities are reduced below 1010atoms∕cm2 on the Ge surface after pretreatment with mixed solution of HCl and H2O2. We conclude that decrease in metal impurities at Ge surface is responsible for the superior C-V characteristic of Ge MOS capacitor.
Landfill methane oxidation response to vegetation, fertilization, and liming.

Landfills are the fourth largest global source and the largest US source (USDOE, 1997) of anthropogenic CH{sub 4} emissions. Since gram-for-gram, CH{sub 4} has 21 times the 100-yr global-warming potential of CO{sub 2} (USEPA, 1990). CH{sub 4} release into the atmosphere has important implications for global climate change. This study was conducted to evaluate the effects of vegetation, N fertilizers, and lime addition on landfill CH{sub 4} oxidation. Columns filled with compacted sandy loam and sparged with synthetic landfill gas were used to simulate a landfill cover. Grass-topped and bare-soil columns reduced inlet CH{sub 4} by 47 and 37%, respectively, at peak uptake; but the rate for both treatments was about 18% at steady state. Nitrate and NH{sub 4} amendments induced a more rapid onset of CH{sub 4} oxidation relative to KCl controls. However, at steady state, NH{sub 4} inhibited CH{sub 4} oxidation in bare columns but not in grassed columns. Nitrate addition produced no inhibitory effects. Lime addition to the soil consistently enhanced CH{sub 4} oxidation. In all treatments, CH{sub 4} consumption increased to a peak value, then declined to a lower steady-state value; and all gassed columns developed a pH gradient. Neither nutrient depletion nor protozoan grazing couldmore » explain the decline from peak oxidation levels. Ammonium applied to grassed cover soil can cause transient reductions in CH{sub 4} uptake, but there is no evidence that the inhibition persists. The ability of vegetation to mitigate NH{sub 4} inhibition indicates that results from bare-soil tests may not always generalize to vegetated landfill caps. « less
Studies in History and Philosophy of Modern Physics

Standard descriptions of thermodynamically reversible processes attribute contradictory properties to them: they are in equilibrium yet still change their state. Or they are comprised of non-equilibrium states that are so close to equilibrium that the difference does not matter. One cannot have states that both change and no not change at the same time. In place of this internally contradictory characterization, the term “thermodynamically reversible process” is here construed as a label for a set of real processes of change involving only non-equilibrium states. The properties usually attributed to a thermodynamically reversible process are recovered as the limiting properties of this set. No single process, that is, no system undergoing change, equilibrium or otherwise, carries those limiting properties. The paper concludes with an historical survey of characterizations of thermodynamically reversible processes and a critical analysis of their shortcomings. & 2016 Elsevier Ltd. All rights reserved. When citing this paper, please use the full journal title Studies in History and Philosophy of Modern Physics
Melt inclusion constraints on mantle carbon heterogeneity within an individual mantle plume and at the global scale

The Earth’s mantle holds more carbon than its oceans, atmosphere and continents combined, yet the distribution of carbon within the mantle remains uncertain. Global variations in the carbon content of the depleted mantle have been inferred from carbon-trace element systematics of ultra-depleted mid-ocean ridge glasses and melt inclusions, though the origin of mantle carbon variability remains uncertain. A variety of observations suggest that the mantle plumes underlying ocean islands have high bulk carbon contents, but the characterisation of individual mantle plume components has not been possible. We supplement the existing melt inclusion data from Iceland with four new datasets, significantly en- hancing the spatial and geochemical coverage. Within the combined dataset there is significant variation in melt inclusion CO2/Ba ratio, which is tightly correlated with trace element enrichment. The trends in CO2/Ba–Ba space displayed by our new data coincide with the same trends in data compiled from global ocean islands and mid-ocean ridges, forming a global array. The overall structure of the global CO2/Ba array is not a property of the source, instead controlled by CO2 degassing before melt inclusion entrapment, and CO2 loss by decrepitation following inclusion entrapment. The position of melt inclusion datasets within the global array allows us to filter out inclusions likely to have undergone decrepitation. Providing earlier CO2 degassing and magma mixing have not destroyed the mantle signal, the remaining inclusions may preserve mantle CO2/Ba values. Using the observed covariation of the filtered CO2/Ba ratio with radiogenic isotope tracers of mantle source, we find CO2 concentrations in the Icelandic depleted mantle of 102+53 -27 ppmw, typical of mantle underlying the mid-ocean ridge system, and high CO concentrations of 2.2+3.8 -1.5 wt% associated with the high 3He/4He component of the Iceland plume. However, source and process are difficult to deconvolve for the eruptions most sensitive to enriched, or recycled, mantle components; the presently available data is consistent with recycled material being either enriched or depleted in carbon. Extending our approach globally, we find no systematic variation in CO2/Ba or CO2/Nb with enrichment (in the absence of a primordial mantle contribution). The lack of global co-variation suggests mechanisms recycling CO2 from the surface into the convecting mantle are decoupled from those recycling most trace elements. However, the variation of CO2/Nb with Ba/Nb suggests Ba may behave similarly to CO2 during recycling.
Au nanoparticle templated synthesis of pNIPAm nanogels

We have explored a synthetic route toward poly(N-isopropylacrylamide) (pNIPAm) nanogels by growing a pNIPAm shell onto a metal nanoparticle seed. Nuclei compatible with precipitation polymerization of thermoresponsive polymers were formed by adsorption of NH2-terminated pNIPAm on Au nanoparticles. The adsorbed pNIPAm layer, when heated above the LCST, collapses onto the Au nanoparticle surface. This polymer layer thus serves as a hydrophobic nucleus for growing pNIPAm oligoradicals during polymer synthesis, resulting in the formation of a pNIPAm shell. Etching of the Au core from the polymer-coated particles with KCN results in hollow hydrogel nanoparticles. The rate of Au core etching as studied by the decrease in Au nanoparticle plasmon absorbance was shown to depend on polymer shell composition, shell thickness, and the thermosensitivity of the polymer. Efficient quenching of fluorophores incorporated in the polymer shell by the core Au nanoparticles was observed; however, the shell fluorescence was re.
Capacitance-voltage characteristics of organic thin-film transistors

We have fabricated pentacene-based thin film field-effect transistors and analyzed quasi-static current and capacitance measurements as a function of gate bias. The latter provides an independent and accurate estimation of the threshold voltage, an important device parameter that cannot be extracted unambiguously from the I-V measurements. The C-V characteristics of the transistors were furthermore characterized using impedance spectroscopy as a function of frequency and gate bias for the zero drain bias case. We model the impedance data with a simple transmission line equivalent circuit and find that the frequency dependence of the capacitance and phase can be described adequately from the channel conductance, as determined from quasi static current-voltage measurements, and the geometrical values of the channel and source/drain to gate electrode overlap capacitances.
Donor and Acceptor Levels in Semiconducting Transition Metal Dichalcogenides

Density functional theory calculations are used to show that it is possible to dope semiconducting transition-metal dichalcogenides (TMD) such as MoS${}_{2}$ and WS${}_{2}$ with electrons and/or holes either by chemical substitution or by adsorption on the sulfur layer. Notably, the activation energies of lithium and phosphorus, a shallow donor and a shallow acceptor, respectively, are smaller than 0.1 eV. Substitutional halogens are also proposed as alternative donors adequate for different temperature regimes. All dopants proposed result in very little lattice relaxation and, hence, are expected to lead to minor scattering of the charge carriers. Doped MoS${}_{2}$ and WS${}_{2}$ monolayers are extrinsic in a much wider temperature range than 3D semiconductors, making them superior for high temperature electronic and optoelectronic applications.
Reaction network and kinetics of propane oxydehydrogenation over nickel cobalt molybdate

Reaction kinetics and a proposed mechanism for the oxydehydrogenation of propane over Ni0.5Co0. 5MoO4/SiO2are described. The reaction pathway proceeds by propane oxydehydrogenation yielding propylene as the exclusive primary product. The propylene thus formed oxidizes further primarily to acrolein, which oxides still further to waste products CO and CO2, and acrylic acid. The relative rate of acrolein formation from propylene is 3.5 times that of propylene formation from propane, the rate of COxformation from acrolein is 13 times that of acrolein formation from propylene, and the rate of COxformation from acrolein is 46 times that of propylene formation from propane. Kinetic isolation of intermediates is therefore imperative for the recovery of practical amounts of useful products, and might be achievable through dioxygen limitation in the feed or utilization of cocatalysts to produce more stable intermediates. The selective oxidation of propane to propylene and propylene to acrolein are both zero order in oxygen and first order in hydrocarbon (propane and propylene, respectively). Deep oxidation of propane (to CO and CO2) is half order in oxygen and first order in propane, while deep oxidation of propylene exhibits Langmuir type dependence on hydrocarbon and is half order in oxygen. Propane/propylene competition experiments reveal that propylene competes for the same metal oxide sites on which propane activation occurs. Their respective effectivenesses are of the same order of magnitude, with propylene being favored by a factor of 2.3 at equimolar concentration. These results are consistent with a direct pathway (i.e., surface mediated reaction) for the formation of useful products from both propane and propylene, and consecutive overoxidation of sorbed intermediates leading to deep oxidation. Kinetic isotope effects for both propane (kH/kD)C°3=1.7) and propylene ((kH/kD)C3==1.9) activation reveal methylene hydrogen abstraction and allylic hydrogen abstraction, respectively to be the rate determining steps.
Lubricating oils based on chemically modified vegetable oils

Vegetable oils are a type of easily biodegradable ester-type lubricant derived from renewable resources. Their importance, from the environmental view-point, is evident, especially in loss lubrication, hydraulic systems with increased risk of damage, etc. They are characterised by good lubricity and good anticorrosion and temprature-viscosity properties. Some disadvantages, particularly low thermal oxidation stability and poor cold flow behaviour, can be mitigated by structural modifications. In this study, possible substitutions of the alcohal part of triacylglycerols as well as changes in acyl unsaturated chains are discussed. Attention is paid particularly to the epoxidising of double bonds in acyls resulting in the formation of oxirane rings. By opening these in the presence of hydrogen donors, it is possible to obtain new derivatives and polyfunctional compounds that are acceptable as environmentally friendly lubricants.
Sodium chloride sensing by using a near-field microwave microprobe

The authors observed the NaCl concentration of solutions using a near-field microwave microprobe (NFMM). Instead of the usual technique, they take advantage of the noncontact evaluation capabilities of a NFMM. A NFMM with a high Q dielectric resonator allows observation of small variations of the permittivity due to changes in the NaCl concentration. By measuring the reflection coefficient S11, they could observe the concentration of NaCl. The measured signal-to-noise was about 53dB and the minimum detectible signal was about 0.005dB∕(mg∕ml). In order to determine the probe selectivity, they measured a mixture solution of NaCl and glucose.
Fermi liquid breakdown and evidence for superconductivity in YFe2Ge2

In the d‐electron system YFe2Ge2, an unusually high and temperature dependent Sommerfeld ratio of the specific heat capacity C /T ∼ 100 mJ/(mol K2) and an anomalous power law temperature dependence of the electrical resistivity ρ≃ρ0+AT3/2 signal Fermi liquid breakdown, probably connected to a close‐by quantum critical point. Full resistive transitions and DC diamagnetic screening fractions of up to 80% suggest that pure samples of YFe2Ge2 superconduct below 1.8 K. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
FRAP and FCS studies of self-diffusion and mutual diffusion in entangled DNA solutions

Two fluorescence techniques, fluorescence recovery after photobleaching and fluorescence correlation spectroscopy, have been used to monitor respectively self-diffusion and mutual diffusion in entangled phage X DNA solutions. Ethidium monoazide, which binds covalently to the DNA, and ethidium bromide, a noncovalently bound intercalator, were the fluorescent labels. For the DNA concentration regime examined, 17 pg/mL I c 5 305 pg/mL, it was found that the mutual-diffusion coefficient increases markedly with concentration, i.e., D, 0: co,65-co,83. The self-diffusion coefficient, on the other hand, decreases by about 50% as the DNA concentration is increased from 40 to 300 pg/mL. The data presented here are in qualitative agreement with a body of theoretical work and with results obtained in recent light scattering studies of self-diffusion and mutual diffusion in interacting DNA solutions. The FCS data also support Phillies's prediction that a mutual-diffusion coefficient is extracted from an FCS experiment if essentially all the macromolecules in the system are fluorescently labeled.
Molecular Dynamics Study of Liquid Water

A sample of water, consisting of 216 rigid molecules at mass density 1 gm/cm3, has been simulated by computer using the molecular dynamics technique. The system evolves in time by the laws of classical dynamics, subject to an effective pair potential that incorporates the principal structural effects of many‐body interactions in real water. Both static structural properties and the kinetic behavior have been examined in considerable detail for a dynamics ``run'' at nominal temperature 34.3°C. In those few cases where direct comparisons with experiment can be made, agreement is moderately good; a simple energy rescaling of the potential (using the factor 1.06) however improves the closeness of agreement considerably. A sequence of stereoscopic pictures of the system's intermediate configurations reinforces conclusions inferred from the various ``run'' averages: (a) The liquid structure consists of a highly strained random hydrogen‐bond network which bears little structural resemblance to known aqueous crys.
Temperature dependent relaxation and recombination dynamics of the hydrated electron

The ultrafast solvation and recombination dynamics of the hydrated electron generated by two-photon ionization of water at 4.65 eV is studied by transient absorption spectroscopy as a function of temperature in the range from 277 K to 355 K. The part of the spectral blue shift which is observed in the absorption spectrum of the hydrated electron after 1 ps is purely continuous and is accurately described by the well known analytical expression for the temperature dependent absorption spectrum of the ground state hydrated electron. This indicates that thermal relaxation or more likely solvation of the hydrated electron predominantly causes the blue shift. The survival probability of the hydrated electron shows a strong temperature dependence, which is satisfactory explained by the temperature dependent mobility and reaction rates of the species involved in the recombination. This implies that the average initial separation between the hydrated electron and the ionization site of 〈r0〉=1.0±0.1 nm does not de.
A screening protocol for bioremediation of contaminated soil

A bioremediation treatability protocol for soil is presented which can provide feasibility study and remedial action engineers maximum information with respect to the viability and efficiency of bioremediation. The protocol, divided into two main phases, progressively evaluates the viability of biodegradation and the requirements for optimization of the process once implemented. Chemical and microbiological baseline conditions and the potential for contaminant degradation are assessed during Phase I screening. During Phase II the endpoint achievable and kinetics of the biodegradation reactions can be established with pan and slurry reactor tests for ex-situ systems or column tests for in-situ systems. Models are reviewed which can predict the rate of removal of organic constituents, and these data in conjunction with the Phase I and II may be used to estimate the potential time required to achieve cleanup standards, assess the relative importance of biological versus chemical removal mechanisms, and compare expected performance of alternative bioremediation methods. 45 refs., 4 figs., 4 tabs.
Hemispheric Difference of Regional Brain Function Exists in Patients With Acute Stroke in Different Cerebral Hemispheres: A Resting-State fMRI Study

Objective To explore the different compensatory mechanisms of brain function between the patients with brain dysfunction after acute ischemic stroke (AIS) in the dominant hemisphere and the non-dominant hemisphere based on Resting-state Functional Magnetic Resonance Imaging (Rs-fMRI). Methods In this trial, 15 healthy subjects (HS) were used as blank controls. In total, 30 hemiplegic patients with middle cerebral artery acute infarction of different dominant hemispheres were divided into the dominant hemisphere group (DH) and the non-dominant hemisphere group (NDH), scanned by a 3.0 T MRI scanner, to obtain the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) and compare the differences. Results Compared with the HS, increased ALFF values in the brain areas, such as the bilateral midbrain, were observed in DH. Meanwhile decreased ReHo values in the brain areas, such as the right postcentral gyrus (BA3), were also observed. Enhanced ALFF values in the brain areas, such as the left BA6, and enhanced ReHo values in the brain areas, such as the left precuneus, were observed in the NDH. The ALFF and ReHo values of the right BA9 and precentral gyrus were both increased. Compared with DH, the NDH group showed lower ALFF values in the left supplementary motor area and lower ReHo values in the right BA10. Conclusion After acute infarction in the middle cerebral artery of the dominant hemisphere, a compensation mechanism is triggered in brain areas of the ipsilateral cortex regulating motor-related pathways, while some brain areas related to cognition, sensation, and motor in the contralateral cortex are suppressed, and the connection with the peripheral brain regions is weakened. After acute infarction in the middle cerebral artery of the non-dominant hemisphere, compensatory activation appears in motor control-related brain areas of the dominant hemisphere. After acute middle cerebral artery infarction in the dominant hemisphere, compared with the non-dominant hemisphere, functional specificity in the bilateral supplementary motor area weakens. After acute middle cerebral artery infarction in different hemispheres, there are hemispheric differences in the compensatory mechanism of brain function.
Shape-Controlled Synthesis of Single-Crystalline Fe2O3 Hollow Nanocrystals and Their Tunable Optical Properties

Single-crystalline α-Fe2O3 hollow nanocrystals from nanotube to nanoring have been successfully synthesized by a facile hydrothermal method. Size and shape control of the hollow nanocrystals is achieved by simple adjustments of reactants’ concentration and molar ratio without any surfactant assistance. The steady absorption spectra indicate a size-dependent blue shift of these hollow nanocrystals. The femtosecond optically heterodyne optical Kerr effect measurements show that the sample that has the smallest diameter possesses the largest third-order nonlinear optical susceptibility. This is ascribed to the remarkably enhanced local electric field in the small particle in accord with finite-difference time-domain simulations. These results reveal that both size and shape of these hollow nanocrystals have significant contributions to their optical response.
Ammonium Oxidation in Mixed-population Biofilms Determined with the Use of Microelectrodes and in situ Hybridization.

Ammonium oxidation in wastewater biofilms grown on rotating biological contactors (RBCs) was investigated by using microelectrodes and fluorescent in situ hybridization (FISH) technique. The density of ammonia-oxidizers which formed dense cell cluster was about 5 times higher in the innermost biofilm than in the middle and surface of the biofilm. Due to the presence of ammonia-oxidizers throughout the biofilm, ammonium oxidation zone was expanded with increasing in oxygen penetration depth, which consequently resulted in an increase of the overall ammonium flux into the biofilm. Specific ammonium oxidation rate was dependent upon the density of ammonia-oxidizers. Although more ammonia-oxidizers were detected in the innermost layer, they might be in the dormant state and not contribute ammonium oxidation during the RBC operation because of substrate transport limitation. Furthermore, the fraction of O2 consumption for nitrification to total O2 consumption was in the range of 35% -53% in a medium with ammonium as the sole electron donor, indicating the biofilm consumed a significant amount of oxygen for other than nitrification. It implied that heterotrophs would grow and outcompete nitrifiers in biofilms even though there was no organic carbon source in the medium. In conclusion, the combination of microelectrode measurements and FISH technique made it possible to relate the spatial organization of ammonia-oxidizers with their in situ ammonium oxidation rates in biofilms, which obviously providing more insight into the nitrification process in wastewater biofilm systems.
The Location of Complex Molecules in G34.3 + 0.2: Further Evidence for Grain-Surface Chemistry

In order to determine the location of the complex molecules CH3OH, CH2CHCN, HCOOCH3, CH3CH2CN, CH3CH2OH, and CH3OCH3 and in the G34.3 + 0.2 star-forming complex, BIMA Array observations of transitions near 104 and 107 GHz were carried out with 13″ × 8″ resolution. One site of complex molecule emission was detected. This core is located near the cometary H II region G34.3 + 0.2 C. The proximity of this core containing complex species to an ultracompact H II region is quite similar to the Sgr B2(N) core. This similarity suggests that, as appears to be the case in Sgr B2(N), a nearby, newly-formed massive star has evaporated grain mantles, releasing large amounts of complex species into the gas phase.