Miracle-dz/UniFAR-FTUs huggingface dataset:
A new SOI high-voltage device with a step-thickness drift region and its analytical model for the electric field and breakdown voltage

A new SOI high-voltage device with a step-thickness drift region (ST SOI) and its analytical model for the two-dimension electric field distribution and the breakdown voltage are proposed. The electric field in the drift region is modulated and that of the buried layer is enhanced by the variable thickness SOI layer, thereby resulting in the enhancement of the breakdown voltage. Based on the Poisson equation, the expression for the two-dimension electric field distribution is presented taking the modulation effect into account, from which the RESURF (REduced SURface Field) condition and the approximate but explicit expression for the maximal breakdown voltage are derived. The analytical model can explain the effects of the device parameters, such as the step height and the step length of the SOI layer, the doping concentration and the buried oxide thickness, on the electric field distribution and the breakdown voltage. The validity of this model is demonstrated by a comparison with numerical simulations. Improvement on both the breakdown voltage and the on-resistance (Ron) for the ST SOI is obtained due to the variable thickness SOI layer.
A general and efficient method for the synthesis of silyl-protected arenethiols from aryl halides or triflates

An improved palladium-catalyzed synthesis of silyl-protected arenethiols has been developed. This method is particularly useful because of its experimental simplicity, high generality and high level of functional group toleration. The first synthesis of enantiomerically pure [2.2]paracyclophane-4-thiol was realized employing this method.
Totalsynthese von (±)‐2,2‐Diethyl‐3‐methyl‐ und (±)‐2,2‐Diethyl‐3,6‐dimethyl‐6‐(phenoxyacetamido)penam‐3‐carbonsäure

Die im Titel genannten Verbindungen 4I und 4k wurden (als Kaliumsalze 4I' bzw. 4k') ausgehend von 5,5-Diethyl-4-methyl-2-thiazolin-4-carbonsaure-benzylester (3a) dargestellt. — An mehreren Beispielen wird die Synthese von 2-Thiazolin-4-carbonsaure-benzylestern (Typ 3) aus Thioketonen 2 und 2-metallierten 2-Isocyanalkansaureestern 1b und d beschrieben. Synthesis of (±)-2,2-Diethyl-3-methyl- and (±)-2,2-Diethyl-3,6-dimethyl-6-(phenoxyacetamido)-penam-3-carboxylic acid The title compounds 4I and 4k were synthesized as the potassium salts 4I', 4k' starting from benzyl 4-methyl-2-thiazolinecarboxylate (3a). — The preparation of several benzyl 2-thiazoline-4-carboxylates (type 3) from thioketones 2 and 2-metalated benzyl 2-isocyanoalkanecarboxylates 1b, d is described.
Synthesis and characterization of anionic graft copolymers containing poly(ethylene oxide) grafts

Anionic graft copolymers were synthesized through grafting of poly(ethylene glycol) monomethyl ether (MPEG) onto terpolymers containing succicinic anhydride groups. The backbone polymers were prepared through radical terpolymerization of maleic anhydride, styrene, and one of the following monomers: methyl methacrylate, ethylhexyl methacrylate, and diethyl fumarate. MPEG of different molecular weights were grafted onto the backbone through reactions with the cyclic anhydride groups. In this reaction one carboxylic acid group is formed together with each ester bond. The molecular weights of MPEG were found to influence the rate of the grafting reaction and the final degree of conversion. The graft copolymers were characterized by IR, GPC, and IH-NMR. Thermal properties were examined by DSC. Graft copolymers containing 50% w/w of MPEG 2000 grafts were found to be almost completely amorphous, presumably because of crosslinking, and hydrogen bonding between carboxylic acid groups in the backbone and the ether oxygens in MPEG grafts. (Less)
Solution properties of mobility control polymers

The solution properties of xanthan gum are presented for application in Pennsylvania oil sands of low permeability. A precise low-shear capillary viscometer has been designed to evaluate the solutions prepared by orifice and propellar blending. Relative molecular weights as a result of mechanical degradation have been obtained from intrinsic viscosity measurements. The effects of salt content, polymer concentration, temperature, mechanical degradation, and shear rate on viscosity are discussed. (31 refs.)
Enthalpy of Fusion of Indium: A Certified Reference Material for Differential Scanning Calorimetry†

An adiabatic calorimeter was used to measure the enthalpy of fusion of a sample of high-purity bismuth. The new value of the enthalpy of fusion was determined to be ΔfusH = (53.146 ± 0.082) J·g-1, where the uncertainty corresponded to a 95% confidence interval. The temperature of fusion of this sample was found not to differ with previous accurate determinations within the accuracy of the fusion-temperature determination made in the present study. A comparison with some other enthalpy of fusion determinations is made.
Copolymerization of 2-Ethylhexyl Acrylate and D-Limonene

The bulk free radical copolymerization of D-limonene and 2-ethylhexyl acrylate (EHA) was conducted at 80°C using benzoyl peroxide (BPO) as initiator. Low conversion experiments were conducted to estimate the copolymer reactivity ratios. The reactivity ratios r1 = 6.896 and r2 = 0.032 (1 = EHA, 2 = d-limonene) were obtained using a non-linear, error-in-variables method with the RREVM computer program. High conversion experiments were performed and revealed that a degradative chain transfer mechanism for D-limonene dominated the polymerization. GRAPHICAL ABSTRACT
Trifluoroacetic Acid as an Efficient Catalyst for the Room Temperature Synthesis of 2-Aryl-1-arylmethyl-1H-1,3-benzimidazoles in Aqueous Media

Trifluoroacetic acid (TFA) is introduced as a commercially available, inexpensive and effective catalyst for the selective and eco-compatible synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles via condensation reaction of o-phenylenediamine derivatives and aromatic aldehydes in ethanol/water at room temperature.
Light upconversion by triplet–triplet annihilation in diphenylanthracene-based copolymers

Low-power light upconversion by triplet–triplet annihilation (TTA-UC) was only recently achieved in glassy materials. Here, a new strategy based on covalent tethering of diphenylanthracene (DPA) emitters to a polymeric backbone is reported. The design aims to optimize the efficiency of this photophysical process in glassy polymeric materials by increasing the emitter content. To that end, DPA molecules were covalently attached to a methacrylate-type monomer and further copolymerized with methylmethacrylate (MMA). Green-to-blue (543 to 440 nm) upconversion was observed at power densities as low as 32 mW cm−2 in films prepared by solution casting and compression molding (co)polymers containing 8–72 wt% of DPA and palladium octaethyl porphyrin (PdOEP) as a sensitizer (0.03–0.7 wt%). The upconversion intensity was studied as a function of DPA and PdOEP contents and the results suggest that upconversion is optimal for DPA and PdOEP weight fractions of 34 and 0.05 wt% respectively.
Grand-Canonical Monte Carlo and Molecular-Dynamics Simulations of Carbon-Dioxide and Carbon-Monoxide Adsorption in Zeolitic Imidazolate Framework Materials

The nature of guest binding sites and selectivity in the zeolitic imidazolate framework (ZIF) 68 and 69 structures are studied by grand-canonical Monte Carlo and molecular-dynamics simulations. We have used the force field of Liu and co-workers to simulate CO2 and CO adsorption isotherms in the ZIF 68 and 69 structures at 273 K for pressures up to 1 atm. The experimental CO2 adsorption isotherms are reproduced with good accuracy, but the same force-field protocol overestimates the CO adsorption isotherms. In addition to the total guest adsorption in the unit cell of the ZIF structures from the adsorption isotherms, we determined the relative distribution of the guests in the pores and channels. The nature and number of the binding sites in the channels and pores are determined from the guest probability distributions in the ZIF structures. We find that the CO2 molecules associate strongly with the benzene rings of the benzimidazolate anion. The binding energies in the pores and channels for different numb.
Impact of embryo biopsy stage on implantation potential in thalassemias: a propensity score matching study

Objective: To investigate the impact of biopsy stage on implantation potential of frozen-warmed blastocysts in pre-implantation genetic testing (PGT) cycles for those with thalassemias.Design: Retrospective paired cohort study using propensity score matching (PSM). A time-to-event analysis of Fine-Gray’s analysis was used to compare cumulative live birth rate (CLBR). Setting: Single university-affiliated center . Patient(s): A total of 439 PGT couples were included who underwent PGT for thalassemias between 2015 and 2017.Intervention(s): Two biopsy strategies were evaluated; cleavage-stage biopsy (CB) and blastocyst-stage biopsy (BB). Main Outcome Measure(s): Implantation rate and CLBR.Result(s): A total of 202 ovum pick-up (OPU) cycles from Group CB and 237 OPU cycles from Group BB were included. PSM was conducted for two groups covering characteristics on the OPU cycle and the first frozen-warmed blastocyst transfer (FWBT) cycle , resulting in 140 matched pairs. The implantation rate was significantly lower in the CB group (41.0%, 30.3%, 20.4% in 1st, 2nd and 3rd FWBT cycle respectively, weighted mean 34.2%) than those in the BB group (51.8%, 43.5%, and 40.5% (weighted mean 48.1%), respectively; at P = 0.044, 0.047, 0.039). This was a 28.9% relative reduction ( P = 0.002). The CLBR across three FWBT cycles was significantly higher in the BB group compared with the CB group (80.0% vs. 62.1%, P = 0.032), while the likelihood of LBR was 1.21-fold higher after regression adjustment. Conclusion(s): Cleavage-stage biopsy may partially affect the implantation potential and CLBRs of frozen-warmed blastocysts, compared with blastocyst stage biopsy.
Atomic Structure of Buried InAs Sub-Monolayer Depositions in GaAs

The atomic structure of sub-monolayer depositions fabricated by an alternating deposition of 0.5 monolayer InAs and 16 monolayer GaAs is revealed by cross-sectional scanning tunneling microscopy. The resulting InAs-rich structures are about 5 nm wide and laterally separated from each other by about 2 nm, yielding a very high density above 1012 cm-2. The InAs-rich material is not only found within the deposition layer, but remarkably segregated with a segregation coefficient R∼0.7 over several monolayers along the growth direction. A similar segregation coefficient is found in the case of only 4 monolayer GaAs spacer thickness, revealing a more general growth mechanism for sub-monolayer depositions.
EXPERIMENTAL STUDIES ON HEAT TRANSFER AND FRICTION FACTOR CHARACTERISTICS OF TURBULENT FLOW THROUGH A CIRCULAR TUBE FITTED WITH RIGHT AND LEFT HELICAL SCREW-TAPE INSERTS

Experimental investigation on heat transfer and friction factor characteristics of a circular tube fitted with right–left helical screw inserts of equal and unequal length of different twist ratios is presented. The experimental data obtained were compared with those obtained from plain tube published data. The heat transfer enhancement for right–left helical screw inserts is higher than that for straight helical twist for a given twist ratio. The effect of right–left twist length on heat transfer augmentation is presented. The empirical relations for Nusselt number, friction factor relating Reynolds number, twist ratio, and right–left twist distance were formed and found to fit the experimental data within 10% and 20% for Nusselt number and friction factor respectively. Performance evaluation analysis was made, and the performance ratio of more than one was obtained, indicating that the proposed twist inserts can be used effectively for heat transfer augmentation without any loss in pumping power.
Immunoassay for CEA using the novel probe-labeled Ag nanoparticles based on surface-enhanced Raman scattering

In this study, we report the Ag nanoparticles aggregated in the process of the labeling that use the crystal violet as the Raman probe. After this process- immune nanoparticles aggregate with high SERS sensitivity and biological specificity are created. We track and characterize the preparation by employing UV-Vi absorption spectra, Transmission Electron Microscope (TEM) and SERS spectra. With the increase of crystal violet, the aggregate of the Ag nanoparticles also increase, while the intensity of absorption peaks decrease. When the concentration of crystal violet reaches 1.0×10-4 mol/L, new peaks were found in the long wavelengths, and with the increase of the crystal violet, the intensity of the new peaks increase as well. We observe from the TEM, that with the increase of crystal violet, the aggregation degree of the Ag nanoparticles also increase and then they unite together. The SERS activity of the aggregates was directly related to the aggregation degree. Detecting the SERS activity of Ag NPs aggregates labeled with different amount of crystal violet, we found that with the increase of the crystal violet, the SERS signals of NPs aggregates enhanced. However, when the amount of crystal violet exceeded 25μL in 1mL colloidal silver, the Ag NPs occurred agglomeration and thereafter the next preparation of immune-label aggregates was hindered. Whereas, the probe labelled with 12μL crystal violet exhibited a better stability, stronger SERS activity and higher biological specificity, and it may accomplish a highly efficient SERS-based immunoassay. This immune probe was applied for detecting the expression of carcinoembryonic antigen (CEA) in the colon cancer tissue slice. Results show that appropriate immune aggregates labelled with optimum quantity of crystal violet present high stability, strong SERS activity and good immune specificity, which are expected to be applied in the analysis of the protein expression in the tissue section and promising for developing into a clinical tool for diagnosis.
Mapping fire effects on ash and soil properties. Current knowledge and future perspectives.

(1) Environmental Management Center, Mykolas Romeris University, Ateities g. 20, LT-08303 Vilnius, Lithuania. (paulo@mruni.eu), (2) Soil Erosion and Degradation Research Group, Department of Geography, University of Valencia, Valencia, Spain.artemio. cerda@uv.es / www.soilerosion. eu. , (3) Department of Physical Geography and Geoecology, National Taras Shevchenko University: Acad. Glushkova avenue, 2 Kyiv, Ukraine
Preparation and characterization of multifunctional maleimide macromonomers and their cured resins

Multifunctional compounds with pendent and terminal maleimide groups were prepared through the reaction of 4-maleimidobenzoic acid and 5-maleimidoisophthalic acid with diglycidyl ether of bisphenol A. The ratios of the pendent maleimide groups to the terminal maleimide groups in the obtained compounds were varied to tailor the chain length and properties of the maleimide compounds. The maleimide group ratios, determined from differential scanning calorimetry, showed good coincidence with the values calculated from the charged monomer amounts. The good solubility and low softening points of the maleimide compounds indicated their good processability. High glass-transition temperatures (220 °C) were observed for the cured resins because of the relatively high crosslinking density. The curing reaction, thermal stability, and degradation behavior of the resins were also studied with differential scanning calorimetry and thermogravimetric analysis.
Sol−Gel Template Synthesis of Semiconductor Oxide Micro- and Nanostructures

The template method for synthesizing nanostructures involves the synthesis of the desired material within the pores of a nanoporous membrane or other solid. Our work has involved using porous alumina and polymeric filter membranes as the templates. Fibrils or tubules of the desired material are formed within each pore of the template membrane. A number of synthetic methods have been used to synthesize these nanostructures. This paper reviews sol−gel template synthesis: the use of sol−gel chemistry to synthesize semiconductor oxide micro- and nanostructures within the pores of micro- and nanoporous membranes. For example, TiO2 nanotubules and nanofibers of the anatase form have been synthesized. The high surface area offered by these TiO2 nanostructures has been used for photodecomposition of salicylic acid in sunlight. Enzyme immobilization by stannous bridges inside the TiO2 tubes has also been studied. In addition, V2O5 fibrous electrode materials have been prepared by this method and Li intercalation .
A statistical interpretation of rotation and translation functions in reciprocal space

Rotation and translation functions in reciprocal space, commonly used to find the orientation of a known molecular fragment and/or its position in the unit cell, are all identical or closely related to the function Q(R,t) = 〈|Eh|2|Ehp(R,t)|2〉h, where |Eh| is the observed normalized structure factor and Ehp(R,t) is the normalized structure factor for the partial structure, calculated for orientation R and position t. In this paper, this function is derived from statistical considerations without referring to a Patterson synthesis. From the centrosymmetric and noncentrosymmetric probability density functions, Q(R,t) = 1 + 2p2 and Q(R,t) = 1 + p2 are obtained, respectively, where p2 is the fraction of atoms (scattering power) that has been placed in the correct orientation and position in the unit cell. Alternative search functions, for instance using |Eh|4 instead of |Eh|2, are discussed.
Quality control of Harpagophytum procumbens products using High Pressure Liquid Chromatography-Diode Array Detection (HPLC-DAD)

Iridoid and phenylethanoid glycosides were used as compounds to monitor the quality of Devil’s Claw ( Harpagophytum procumbens ) based products in this investigation. A HPLC-DAD method was developed for the determination of the phenylethanoid glycoside isoacteoside and the iridoid glycoside harpagoside in commercially available Devil’s Claw products. The limits of detection (LOD) obtained were 1.08 μg/ml for harpagoside and 1.70 μg/ml for isoacteoside. Limits of quantification (LOQ) of harpagoside and isoacteoside were 3.59 μg/ml and 5.65 μg/ml respectively. The harpagoside and isoacteoside contents in the ethanol extracts of the commercial products were found to be in the range of 2.2 % - 3.9 % and 0.22 % - 0.50 % respectively. Keywords: Harpagophytum procumbens , phenylethanoid glycosides, iridoid glycosides, harpagoside, HPLC-DAD profiles
ELECTROSTATIC SHAPE SEPARATION OF FLAKE MICA FROM PEGMATITES

Electrostatic shape separation was considered to be an adequate technique for processing a particulate mixture of flake mica and isometric granules of feldspar and quartz. The authors carried out extensive laboratory experiments to concentrate flake muscovite from a pegmatitic product with content of 50 to 65% of mica. Prior to electroseparation, the granular material was dried and vibrating screens were employed to obtain two fractions:
Discovering multicore micelles: insights into the self-assembly of linear ABC terpolymers in midblock-selective solvents

Using self-consistent field calculations, multicore micelles, such as the double-stranded superhelix, were discovered from the solution-state self-assembly of linear ABC terpolymers consisting of a solvophilic midblock and two mutually incompatible solvophobic endblocks. The multicore micelles were formed when the A and C endblocks self-associated into multiple incompatible solvophobic cores that were subdivided alternately by solvophilic B domains, thereby constructing hierarchical packing. The structures emerged depended on the relative lengths of the blocks and the solubility of the midblocks. According to the calculation results, diagrams of the observed structures as a function of the block length and midblock solubility were constructed. The results obtained can enrich our existing knowledge of the hierarchical assembly of copolymers and provide useful information for mimicking complex biological systems.
A molecular simulation study of commensurate–incommensurate adsorption of n-alkanes in cobalt formate frameworks

The channels of the cobalt formate frameworks consist of one-dimensional channels that have a zig-zag configuration. Propane (C3) has a length that commensurates with the channel segment length; longer n-alkanes such as n-butane (nC4), n-pentane (nC5) and n-hexane (nC6) have conformations that straddle two channel segments. Configurational-bias Monte Carlo (CBMC) simulations show that the adsorption strength of C3 is higher than that of n-butane (nC4) and n-pentane (nC5); this unusual hierarchy is a direct consequence of the commensurate–incommensurate adsorption. CBMC simulations also reveal the possibility of separating C3–nC6, C3–nC4, nC4–nC6 and nC4–nC5 liquid mixtures for which the adsorbed phase contains predominantly the shorter alkane. Molecular dynamics simulations show that the hierarchy of self-diffusivities is non-monotonic and is the mirror image of the hierarchy of adsorption strengths.
A análise por injeção sequencial (SIA): vinte anos em uma perspectiva brasileira

The year of 2010 marks the 20th anniversary of the development of Sequential Injection Analysis (SIA) by Ruzicka and Marshall. Considered the second generation of the flow injection methods, this article briefly describes the history, the basic principles of the technique and reviews all papers developed by Brazilian scientists aiming the divulgation of this automation technique in Analytical Chemistry.
Carbon Nanotubes and Spheres Produced by Modified Ferrocene Pyrolysis

Single-wall carbon nanotubes (SWCNTs) and well-aligned thin multiwall carbon nanotubes (MWCNTs) were successfully synthesized via pyrolysis of a powder mixture of ferrocene and anthracene or 9,10-dibromoanthracene. It is shown that the size of the MWCNTs can be tuned just by changing the ratio of ferrocene/anthracene in the mixture. A lower ratio resulted in low-diameter MWCNTs containing up to five graphene layers only; a high ratio has led to thick MWCNTs with more than 25 layers. Furthermore, there are two extreme cases, the pyrolysis of powders at a low ratio of 1:7 that gives rise to carbon nanospheres and the pyrolysis of pure ferrocene in a H2 flow that mainly gives rise to metal nanoparticles. When powder mixtures of ferrocene and 9,10-dibromoanthracene are pyrolyzed, both SWCNTs and spherical carbon-coated iron nanoparticles are obtained.
Spectrophotometric measurement of the vapour-liquid equilibria of (sulphur dioxide + water)

Abstract A new experimental technique based on spectrophotometric measurements is presented for the study of vapour-liquid equilibrium for (sulphur dioxide + water). The in situ analysis of the vapour phase is performed with the help of a diode array UV–Vis. spectrophotometer equipped with silica fibre light guides. Experimental results for the equilibrium partial pressures of (sulphur dioxide + water) at low SO 2 concentrations are compared with existing literature values. The liquid phase has been analysed independently using ion chromatography and confirms the vapour phase measurements. The results favour a value of 0.0139 at T = 298.15 K for the equilibrium constant for the first dissociation reaction of hydrated SO 2 . In addition to the in situ analysis of the gas phase, a method is established for the spectrophotometric analysis of the dissolved molecular sulphur dioxide.