Miracle-dz/UniFAR-FTUs huggingface dataset:
A new organic modifier for anti-stiction

The chemical and mechanical characteristics of a new surface modifier, dialkyldichloromethylsilane (DDMS, CH/sub 3/)/sub 2/SiCl/sub 2/, for stiction-free polysilicon surfaces are reported. The main strategy is to replace the conventional monoalkyl-trichlorosilane (MTS, RSiCl/sub 3/) such as octadecyltrichlorosilane (ODTS) or 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) with dichlorodisilane (DDS, R/sub 2/SiCl/sub 2/) with two short chains, especially DDMS. DDMS, with shorter chains in aprotic media, rapidly deposits on the chemically oxidized polysilicon surface at room temperature and successfully prevents long cantilevers 3 mm in length from in-use as well as release stiction. DDMS-modified polysilicon surfaces exhibit satisfactory hydrophobicity, long term stability and thermal stability, which are comparable to those of FDTS. DDMS as an alternative to FDTS and ODTS provides a few valuable advantages; ease in handling and storage of the solution, low temperature-dependence and low cost. In addition to the new modifier molecule, the simplified process of direct release right after washing the modified surface with isooctane was proposed to cut the processing time.
Synthesis of monodispersed Pt nanoparticles on plasma processed carbon nanotubes for methanol electro-oxidation reaction

Plasma-treated multi-walled carbon nanotubes (MWCNTs) have been used as a substrate for the deposition of Pt nanoparticles. These Pt nanoparticles deposited on MWCNTs showed a higher catalytic activity in a methanol electro-oxidation reaction even with a lower amount of precious metal catalyst used. The higher catalytic activity is attributed to less damage of the carbon nanotubes during plasma treatment. It also shows that direct contact between metal nanoparticles and carbon nanotubes can improve the performance of composites.
The dynamics of formation of HCl products from the reaction of Cl atoms with methanol, ethanol and dimethyl ether

The dynamics of ground state Cl(2P3/2) atom reactions with methanol, methanol-d1, ethanol, and dimethyl ether have been studied both experimentally and theoretically. The reactions were photoinitiated by 355 nm photolysis of Cl2 to produce monoenergetic Cl(2P3/2) atoms that react with ground electronic state organic molecules under single collision conditions. The rotational quantum state population distributions of the nascent HCl(ν′) products were probed by 2+1 resonance-enhanced multiphoton ionization in a time-of-flight mass spectrometer. Nascent HCl(ν′=0) products from reaction of Cl atoms with methanol, methanol-d1 (CH3OD), ethanol, and dimethyl ether, at mean collision energies in the range of 5.6–6.7 kcal/mol, exhibit distributions of population over rotational levels that all peak at J′=3–5. The average rotational energies of the HCl(ν′=0) products for the respective reactions are 〈Erot〉=330±29, 300±24, 340±24, and 256±17 cm−1 (1σ uncertainties). Ab initio calculations were performed in order to .
Surface-Active cis-Pinonic Acid in Atmospheric Droplets: A Molecular Dynamics Study

Water vapor in the atmosphere can condensate and form cloud droplets when there is a certain amount of humidity and a presence of cloud condensation nuclei, and organic solutes called surfactants can significantly lower the surface tension of water — one of the parameters determining cloud droplet population. We here present a molecular dynamics study of the behavior of cis-pinonic acid, a commonly found organic compound in cloud condensation nuclei, and its effect on the surface tension of water clusters. Specifically, the decrease in surface tension is found to depend on not only the concentration of the organic compound but also the droplet size due to the spontaneous assembly of the surfactant molecules on the droplet surface. This leads to the conclusion that the partitioning of the surfactant between the bulk and surface plays an important role in the behavior of atmospheric aerosol particles and thus in their availability for cloud formation.
Propagation of electrical tree structures in solid polymeric insulation

Two alternative theoretical approaches to electrical tree propagation exist. Stochastic models attribute tree structures to random probabilistic factors, whereas in the discharge-avalanche model mechanism-driven field fluctuations are responsible. Here we review the predictions of these approaches in the light of the available experimental evidence. It is shown that both models give the fractal structures and the form of structure distribution observed experimentally. The width of the distribution functions predicted are, however, less than those found experimentally. The quantitative formulation available to the physical model also enables it to reproduce several other features of tree propagation such as voltage dependence, growth laws, and discharge behavior patterns. This is not possible in the stochastic approach without mechanistic assumptions which are difficult to relate to the stochastic process. The connection between the discharge-avalanche model and deterministic chaos is explored. Experimental evidence is presented supporting the contention that the electrical treeing phenomenon is the result of a deterministic breakdown mechanism operating in a chaotic regime at fields lower than those required for runaway breakdown. Space-charge deposition and re-arrangement is proposed as the physical origin of the chaotic field fluctuations. Tree shapes are shown to be related to the variation in the fluctuation range available as the tree grows in accord with the predictions of the discharge-avalanche model.
Hydrophilication of Activated Carbon by Impregnating Silica into Pores

A new hydrophilic method for achieving a high-performance adsorbent by impregnating silica into pores of activated carbon has been proposed. In the process, silica-gel was synthesized in the pores of activated carbon after inserting a sodium silicate solution into the pores. Three types of activated carbon were tested to produce hydrophilic activated carbon and to investigate the hydrophilicity by measuring the adsorption isotherms of water vapor and pore structure characteristics. The proposed method worked effectively for adding hydrophilicity to activated carbon, since all of adsorption isotherms of the material treated with this method shifted to a lower region of water vapor pressure than that of the raw material. The shift to a lower relative pressure of adsorption isotherm was maximum when the concentration of sodium silicate solution was 1 mass%.
Palladium-, ligand-, and solvent-free synthesis of ynones by the coupling of acyl chlorides and terminal alkynes in the presence of a reusable copper nanoparticle catalyst

Supported copper nanoparticles are utilized for the first time as a highly efficient and reusable catalyst in the coupling of acyl chlorides and terminal alkynes to prepare various ynones. The reaction is carried out under palladium-, ligand-, and solvent-free conditions. The catalyst can be simply recovered and reused several times without significant loss in catalytic activity.
Thermodynamics and kinetics of phase transformations in the Fe-N-C system

The control of the nitriding/nitrocarburizing process involves both the knowledge of the thermodynamics prescribing the gas-solid and solid-solid phase equilibria of the Fe-N and Fe-N-C systems and kinetics governing the (multicomponent) diffusion of each component in the solid phases formed during the heat treatment. Although nitriding and nitrocarburizing have been widely investigated a fundamental knowledge about the thermodynamics and kinetics, in particular in the Fe-N-C system is still lacking. For that reason the present work is focused on (i) the thermodynamics and kinetics of phase transformations in the Fe-N-C system and (ii) the thermodynamics of the gamma’ phase in the Fe-N system. Die Kontrolle von Nitrier- und Nitrocarburierprozessen beinhaltet die Kenntniss der Thermodynamik, welche die gas-fest sowie die fest-fest Phasengleichgewichte im System Fe-N-C und Fe-N vorgibt, als auch der Kinetik, welche die (mehrkomponentige) Diffusion in jeder einzelnen Phase des Festkorpers bestimmt. Obwohl Nitrier- und Nitrocarburierenprozesse bereits intensiv untersucht wurden, mangelt es immernoch am allgemeinen Verstandnis der zugrundeliegenden thermodynamischen und kinetischen Vorgange, insbesondere im System Fe-N-C. Aus diesem Grund liegt der Schwerpunkt dieser Arbeit auf (i) der Thermodynamik und Kinetik von Phasenumwandlungen im System Fe-N-C und (ii) der Thermodynamik der gamma' Phase im System Fe-N.
Modeling the role of organic compounds in aerosol formation and cloud droplet activation

Atmospheric aerosols are responsible for the formation of cloud droplets by acting as nuclei onto which cloud droplets are formed. This thesis investigates influences of organic compounds on the activation of cloud droplets and the growth of nanometersized thermodynamically stable clusters (TSCs) to sizes in which they can act as nuclei for cloud droplets. Both theoretical analyses and numerical simulations were conducted to identify properties of organic compounds that make them important regarding the considered processes. The obtained results suggest that water-soluble organic compounds are able to influence the cloud droplet formation both by increasing the solute mass of nuclei and by reducing their surface tension. In contrast to compounds totally soluble in water, slightly-soluble compounds have clearly a smaller effect on the number of cloud droplets formed during an air updraft. Due to a strong curvature of TSCs and nanometer-sized particles, organic compounds that might be responsible for aerosol formation at continental boundary layers could not be pinpointed in spite of an extensive search. In order to find such organic compounds, more emphasis should be put on experiments that focus on identifying atmospheric organic compounds that either 1) have a extremely low vapour pressure, or 2) react rapidly in the gas-liquid interface of TSCs or particles such that lowvolatile reaction products are formed.
Nucleation and growth of YBa_2Cu_3O_x on SrTiO_3 and CeO_2 by a BaF_2 postdeposition reaction process

The nucleation and growth of the c -axis-aligned Yba_2Cu_3O_ x on SrTiO_3 and CeO_2, from precursor films, were studied by examining quenched and fully processed specimens using transmission electron microscopy techniques. The precursor films, a stoichiometric mixture of fine-grained Y, Cu, and BaF_2, were deposited using physical vapor deposition methods. An Y-Ba oxy-fluoride formed from the precursor contributed to the nucleation of Yba_2Cu_3O_ x , while a liquid layer between the unreacted precursor and the Yba_2Cu_3O_ x layer played an important role in the growth of Yba_2Cu_3O_ x . However, the process of nucleation of Yba_2Cu_3O_ x on SrTiO_3 and CeO_2 were significantly different.
Diffusion and Stress Coupling Effect during Oxidation at High Temperature

We report the diffusion and stress coupling effect during oxidation. An analytical model is developed for the stress and diffusion coupling effect based on equilibrium relationship and diffusion equation considering for the stress effect. Compressive stress will generate during the oxidation due to the growth strain. This growth stress can modify the diffusion coefficient; therefore, the oxidation kinetics is also affected. The coupling effect reduces both the oxidation rate and the stress. The proposed model is applied to predict the oxidation evolution for SiC and its consistence with the experimental data demonstrates the theoretical analysis.
Biorefining of marine macroalgal biomass for production of biofuel and commodity chemicals

The large scale production of marine macroalgae, mainly for human consumption, has given rise to their consideration as a non-lignocellulosic feedstock for the production of renewable fuels. However, making biofuel economical from algal biomass requires the co-production of additional useful biochemical components that are unique to algae and that have a proven market value. A viable and sustainable biorefining technology that maximizes the utilisation of feedstock for the production of chemicals along with fuel is, therefore, indispensable. Here, we for the first time demonstrate a tractable integrated process that facilitates sequential extraction of the major components of red algal biomass as commodity products such as pigments, lipid, agar, minerals and energy dense substrate (cellulose). The computed yield data from small-scale biorefinery trials suggest that a ton of fresh biomass supplies several valuable extracts: 0.3–0.7 kg of R-phycoerythrin (R-PE), 0.1–0.3 kg of R-phycocyanin (R-PC), 1.2–4.8 kg of lipids, 28.4–94.4 kg of agar, 4.4–41.9 kg of cellulose and 3.1–3.6 kiloliters of mineral solution. The enzymatic hydrolysis and fermentation of cellulose thus obtained would yield 1.8–17.4 kg of ethanol. A distinct advantage of this process over direct extraction is the improved quality of agar (gel strength higher by 1.5–3 fold) without alkali and acid pretreatment of sample, the elimination of residue and the reduction by up to 85% in chemicals usage in cellulose extraction. The findings reported in this study forms the basis for starting new ocean-based bio-industries minimizing the dependence on the terrestrial resources for food, feed, energy and chemicals.
Influence of Shaping on Pd and Pt/TiO2 Catalysts in Total Oxidation of VOCs

The catalytic performance of a commercial TiO2 was investigated towards the total oxidation of toluene. A variety of two titania supports was used in this work, shaped (pellets) and non-shaped (powder) materials. 0.5wt% Pd or Pt were impregnated onto both types of titania supports using the wet impregnation method. A decrease in the surface area of the obtained catalysts was noticed after the catalytic test, although it was still much higher than that of classical titania supports. The catalysts were tested in the total oxidation of toluene, and a major decrease in activity was noticed for Pt impregnated “shaped” supports.
A two-stage procedure for determining unsaturated hydraulic characteristics using a syringe pump and outflow observations

A fast two-stage methodology for determining unsaturated flow characteristics is presented. The procedure builds on direct measurement of the retention characteristic using a syringe pump technique, combined with inverse estimation of the hydraulic conductivity characteristic based on one-step outflow experiments. The direct measurements are obtained with a commercial syringe pump, which continuously withdraws fluid from a soil sample at a very low and accurate flow rate, thus providing the water content in the soil sample. The retention curve is then established by simultaneously monitoring the capillary pressure. The measured retention curves were compared with those obtained by static methods and found to agree closely. Subsequently, a transient outflow experiment is carried out on the same soil sample, in the same apparatus, and the information is obtained on a time-scale of days. The one-step outflow data and the independently measured retention data are included in the objective function of a traditional least-squares minimization routine, providing unique estimates of the unsaturated hydraulic characteristics by means of numerical inversion of Richards equation. As opposed to what is often assumed in practical applications, we found it necessary to allow the exponent (γ) of van Genuchten's hydraulic conductivity expression to vary to obtain satisfactory estimates. Optimized hydraulic conductivity estimates were ultimately compared with directly measured values, and visual agreement was quite satisfactory. However, we encountered numerical instabilities of the optimization code used (SFIT), a flaw that may constitute a potential problem when using this code for the optimization.
Production of novel biodiesel from transesterification over KF-modified Ca–Al hydrotalcite catalyst

A series of KF-modified Ca–Al hydrotalcite (xKF/HTL-M) solid base catalysts was prepared in methanol, and characterized by thermogravimetry analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and carbon dioxide temperature-programmed desorption (CO2-TPD). The catalytic activity was investigated in the transesterification of ethylene glycol monomethyl ether (EGME) with methyl laurate (ML) to produce a novel biodiesel of ethylene glycol monomethyl ether monolaurate (EGMEML). The effect of the mass content of KF and the main reaction parameters such as EGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of EGMEML were examined. The results indicate that a new phase of KCaF3 formed in xKF/HTL-M, and acted as the main active sites for the transesterification. In addition, xKF/HTL-M has excellent catalytic performance in the production of EGMEML. The highest yield of 97.7% was obtained over 24.7KF/HTL-M at EGME/ML molar ratio of 3.0, catalyst amount of 5 wt%, and reaction time of 4 h at 120 °C. Moreover, the catalyst displays a good stability and reutilization. A satisfactory yield of 90% was obtained after use for five consecutive cycles without significant deactivation. Finally, the activation energy (Ea) of the reaction of EGME with ML over 24.7KF/HTL-M was obtained as 27.11 kJ mol−1.
Collective electron effects of O2− in potassium superoxide

A temperature variation study of dc conductivity, magnetic susceptibility, and ESR on powdered potassium superoxide has been carried out. Also reported is a room temperature measurement of the electronic absorption spectrum. We find that at temperatures above the structural phase transition temperature Tc (193.5°K) reported by Carter and Templeton, the susceptibility is given by χ = c/(T + ϑ) with ϑ ∼ 250°K. Below Tc, χ = c′/(T + ϑ) with ϑ′ ∼ 18°K. There is no magnetic ordering down to liquid nitrogen temperature. ESR spectra shows two distinct lines above Tc. The broad line is Lorenzian in shape with a width at half‐maximum of about 700 G. The narrow line has a width of 25 G and the area under this resonance is 10−4 times that under the broad one. The broad line splits into two below Tc. The number of spins contributing to the broad resonance has a temperature dependence which is qualitatively similar to that of the susceptibility. The narrow ESR line persists through the phase transition. At temperature.
Developmental loss of oligodendrocytes exacerbates adult CNS demyelination

Background Multiple sclerosis (MS), a neurodegenerative autoimmune disease characterized by loss of oligodendrocytes and myelin in the brain and spinal cord, results in localized functional deficits. Several risk factors have been associated with MS, however none can fully explain an enhanced susceptibility. Epidemiological data, based on geographical prevalence studies suggest susceptibility is established early in life and frequently long before disease diagnosis implicating developmental events influence adult disease progression. Here we test the hypothesis that loss of mature oligodendrocytes during postnatal development results in enhanced susceptibility to an adult demyelinating insult. Methods A transgenic mouse model was utilized to specifically induce apoptosis in a subset of mature oligodendrocytes (MBP-iCP9) during the first 2 postnatal weeks followed by either a local LPC spinal cord injection or the induction of EAE in the adult. Immunostaining, immunoblotting, behavioral testing, and electron microscopy were utilized to examine the differences between groups. Results We show that during development, oligodendrocyte apoptosis results in transient reductions in myelination and functional deficits that recover after 10-14 days. Compared to animals in which oligodendrocyte development was unperturbed, animals subjected to postnatal oligodendrocyte ablation showed delayed recovery from an LPC lesion. Unexpectedly, the induction and severity of EAE was not significantly altered in animals following oligodendrocyte ablation even though there was a substantial increase in spinal cord tissue damage and CNS inflammation. It is currently unclear why these changes are not reflected in enhanced functional deficits. Conclusions These observations suggest that developmental loss of oligodendrocytes results in long lasting tissue changes that alter its capacity for repair in the adult.
Properties of NMDA receptors in the rat basal ganglia.

Native subtypes of NMDA receptors with distinct developmental and anatomical distribution are present in the brain. Knowledge of their function and pharmacology greatly helps in understanding the involvement of NMDA receptors in physiological and pathological processes in the central nervous system. Multiple patch-clamping methods were carried out in my experiments. First, the single-channel properties of native NMDA receptors were studied in outside-out patches excised from neuronal cell bodies in substantia nigra pars compacta (SNc) and subthalamic nucleus (STN) from 7-day old rats. The steady state channel activations produced by NMDA (100 nM or 200 uM) and glycine (10 uM) were studied at -60 mV. The results showed that both large and small conductance channels are present on STN and SNc neurons. These large conductance NMDA channels from SNc and STN display a high ifenprodil sensitivity, suggesting NR2B-containing NMDA receptors are present on SNc and STN neurons. In addition, direct transition analysis suggests that the small conductance channels may be due to NR2D-containing NMDA receptors. Second, whole-cell patch-clamp recording of bath application-induced NMDA receptor-mediated currents (Inmda) in dopaminergic neurons of SNc in brain slices from P7 rats was used to characterize the ifenprodil inhibition and voltage-dependence of Mg2+ block of NMDA receptors. The NMDA-induced whole-cell currents were evoked by NMDA (10 uM or 200 uM) and glycine (10 pM). There are two main findings from the whole-cell experiments. (1) The NMDA-induced whole-cell currents display a high ifenprodil sensitivity, suggesting the presence of NR2B-containing NMDA receptors on P7 rat SNc neurons. (2) The combined application of Mg2+ and ifenprodil reduced the voltage-dependent Mg2+ block, which is consistent with recombinant NR2D-containing NMDA receptors that have a lower affinity for Mg2+. This suggests that NR2D-containing NMDA receptors are present in P7 rat SNc. Third, in order to evaluate the deactivation kinetics of extrasynaptic NMDARs, outside-out patches containing multiple channels were obtained from P7 rat dopaminergic neurons of SNc and stimulated with a brief synaptic-like (l-4ms) pulse of ImM glutamate. The results suggested that the triheteromeric NR1-NR2B-NR2D rather than diheteromeric NR1-NR2D NMDA receptors are present on extrasynaptic sites of SNc neurons. In addition, in order to investigate voltage-dependent Mg2+ block and memantine block, several channel block models were developed to evaluate multiple Mg2+ effects on native NMDA receptors and competition between Mg2+ and memantine for block of NMDAR channels.
LARGE EDDY SIMULATION OF TURBULENT PREMIXED COMBUSTION USING A MARKER FIELD

Abstract A new laminar flamelet model is presented for Large Eddy Simulation (LES) of premixed turbulent combustion. The model uses a marker field S + to capture the flame. Compared to previous work on marker fields, a modification was introduced to simplify the boundary conditions. Although the scalar S + is smooth in space, it allows describing steep flame fronts. The S + equation captures the laminar or turbulent flame propagation via a reactive diffusive balance. The present LES model was used to simulate a turbulent premixed flame stabilized behind a sudden expansion. The LES predictions agree well with available experimental data in term of reproducing the time averaged velocity field as well as for capturing the flame dynamics and flame response to a perturbation.