Miracle-dz/UniFAR-FTUs huggingface dataset:
Linear stability and transient behaviour of viscoelastic fluids in boundary layers

The linear stability analysis of Rivlin-Ericksen fluids of second order is investigated for boundary layer flows, where a semi-infinite wedge is placed symmetrically with respect to the flow direction. Second order fluids belong to a larger family of fluids called Order fluids, which is one of the first classes proposed to model departures from Newtonian behaviour. Second order fluids can represent non-zero normal stress differences, which is an essential feature of viscoelastic fluids. The linear stability properties are studied for both signs of the elasticity number K, which characterises the non-Newtonian response of the fluid. Stabilisation is observed for the temporal and spatial evolution of two-dimensional disturbances when K > 0, in terms of increase of critical Reynolds numbers and reduction of growth rates, whereas the flow is less stable when K < 0. By extending the analysis to three-dimensional disturbances, we show that a positive elasticity number K destabilises streamwise independent waves, while the opposite happens for K < 0. We show that, as for Newtonian fluids, the nonmodal amplification of streamwise independent disturbances is the most dangerous mechanism for transient energy growth which is enhanced when K > 0 and reduced when K < 0. A preliminary study of boundary layer flows of UCM, Oldroyd B, Phan-Thien Tanner and Giesekus fluids is performed. Asymptotic Suction Boundary Layer theory allows us to simplify the governing equations and obtain analytical solutions for the UCM and Oldroyd B models. The mean flow obtained can be used as a starting point for a modal and nonmodal linear stability analysis, following the analysis performed for second order models.
Fertilizer nitrogen loss via N2 emission from calcareous soil following basal urea application of winter wheat

ABSTRACT The ratio of nitrous oxide (N2O) to N2O plus nitrogen gas (N2) emitted from soils (N2O/(N2O+N2)) is regarded as a key parameter for estimating fertilizer nitrogen (N) loss via N2 emission at local, regional or global scales. However, reliable measurement of soil N2 emissions is still difficult in fertilized soil-crop systems. In this study, the N loss via N2 emission following basal urea application (with a dose of 150 kg N ha−1) to a calcareous soil cultivated with winter wheat was quantified using the helium-based gas-flow-soil-core technique. Emissions of N2 and N2O from sampled fresh soils were measured under simulated field soil temperature and oxygen conditions. Our observation performed on the first day after irrigation and rainfall events showed the highest N2 and N2O emissions, which amounted to approximately 11.8 and 3.8 μg N h−1 kg−1 dry soil, corresponding to 3304 and 1064 μg N m−2 h−1, respectively. The N2O/(N2O+N2) molar ratios within about 10 days following fertilization ranged from 0.07 to 0.25, which were much larger than those at the other time. During the one-month experimental period, the urea-N loss via emissions of N2, N2O, and N2+N2O was 1.6%, 0.6%, and 2.2%, respectively. Our study confirms that the widely applied acetylene-inhibition method substantially underestimates fertilizer N losses via N2 emissions from calcareous soils cultivated with winter wheat. Graphical Abstract
Physical Properties of Reduced Graphite Oxide Prepared via Chemical Reduction by Using Ammonia solution as a Reducing Agent

This research studied the synthesis of graphite oxide and reduced graphite oxide via a low- cost manufacturing method. The process started with the chemical oxidation of commercial graphite powder into graphite oxide by Staudenmaier’s method, followed by the chemical reduction of graphite oxide in ammonium hydroxide vapor. Subsequently, graphite oxide and reduced graphite oxide were assembled into a thin film, and microscale liquid droplets were placed into the film surface for measurement of wettability and contact angle. It is found that a graphite oxide sheet is hydrophilic while a reduced graphite oxide is hydrophobic with a contact angle equal to 120°C and 53°C respectively.
Insights into the Femtosecond to Nanosecond Charge Carrier Kinetics in Perovskite Materials for Solar Cells

In this work, we analyze a few simple methods that permit getting insight into the charge dynamics in methylammonium lead iodide (MAPbI3) perovskites, on the basis of femtosecond transient absorption and fluorescence studies. We show that proper determination of the charge population decay kinetics requires broad spectral integration of the long-wavelength bleach signal (∼760 nm) assigned to the band-filling effect, which can be realized, e.g., by band integral analysis. On the contrary, the kinetics related to a shorter-wavelength bleach band (∼480 nm) behave differently: a single-wavelength decay is sufficient to probe charge population. Moreover, both the shorter-wavelength excitation and higher pump pulse intensities result in significantly longer charge cooling times, which might be important in efficient hot carrier extraction. The validity of our previously proposed easy approach for the elimination of higher-order recombination rates is also discussed and confirmed in terms of proper estimation of.
Expanding Academic Writing: A Multilayered Exploration of What It Means To Belong

In this article, we explore the impact of rigid boundaries of what counts as academic writing and what is means to belong through the construction of a multilayered text that draws on the work of Patti Lather. Our layered writing engages with and documents the complexity of the writing process and the struggle of putting chaos into a static format that cohesively considers the multiplicity of knowing. This alternative format productively disrupts the status quo and honors an engagement with writing we would like to see embraced in the academy.
Effects of carboxymethylcellulose sodium on the morphology and properties of TKX-50, an insensitive high-energy explosive

ABSTRACT Dihydroxylammonium 5,5ʹ-bistetrazole-1,1ʹ-diolate (TKX-50) is an energetic ionic salt with excellent properties of low mechanical sensitivity, environment-friendliness, and low toxicity. It meets the requirement of high insensitivity for military high-energy explosives. However, the poor crystal habit of TKX-50 in most solvents, as well as its poor adhesive ability with conventional binders, has limited its application. In the present work, we report a novel strategy to improve the morphology and surface property of TKX-50 using an environmentally friendly anionic polyelectrolyte, carboxymethylcellulose sodium (CMC), by the anti-solvent method. The scanning electron microscope analysis indicates that the morphology of TKX-50 was greatly altered in the presence of CMC, resulting in TKX-50 granules with low aspect ratios. Molecular dynamics simulation was conducted to explore the mechanism of such morphological change. It was found that the combined action of ethanol and CMC promoted the growth of (110) and (011), while the (020) still dominated the crystal growth, resulting in the low aspect ratio of TKX-50. The effects of CMC coating on the particle size of TKX-50 and the interaction between CMC and TKX-50 were investigated with the focused beam reflectance measurement and particle video microscope. Further characterization suggested that the highest coating efficiency (R) could be obtained at the CMC content of 4% with which granular TKX-50 crystals were produced. The non-isothermal kinetic study revealed that the CMC coating also improved the thermal stability of TKX-50. Our work has provided a novel method to improve the properties of TKX-50 for its practical application.
Supplementary material to "Radiative Forcing by Light-Absorbing Particles in Snow in Northeastern China Retrieved from Satellite Observations"

Abstract. Light-absorbing particles (LAPs) deposited on snow can decrease snow albedo and affect climate through the snow-albedo radiative forcing. In this study, we use MODIS observations combined with a snow albedo model (SNICAR) and a radiative transfer model (SBDART) to retrieve the radiative forcing by LAPs in snow (RFLapsMODIS) across Northeastern China (NEC) in January–February from 2003 to 2017. RFLapsMODIS presents distinct spatial variability, with the minimum (22.3 W m−2) in western NEC and the maximum (64.6 W m−2) near industrial areas in central NEC. The regional mean RFLapsMODIS is ~ 45.1 ± 6.8 W m−2 in NEC. The positive (negative) uncertainties of retrieved RFLapsMODIS due to atmospheric correction range from 14 % to 57 % (−14 % to −47 %) and the uncertainty value basically decreased with the increased RFLapsMODIS. We attribute the variations of radiative forcing based on remote sensing and find that the spatial variance of RFLapsMODIS in NEC is 74.6 % due to LAPs, while 21.2 % and 4.2 % due to snow grain size, and solar zenith angle. Furthermore, based on multiple linear regression, the BC dry and wet deposition and snowfall could totally explain 81 % of the spatial variance of LAP contents, which confirms the reasonability of the spatial patterns of retrieved RFLapsMODIS in NEC. We validate RFLapsMODIS using in situ radiative forcing estimates. We find that the biases in RFLapsMODIS are negatively correlated with LAP concentrations and range from ~ 5 % to ~ 350 % in NEC.
Studies of the role of MAP kinase-activated protein kinase-5 (MK5) in reactive and reparative fibrosis in the murine heart

MK5 is a serine/threonine kinase, originally identified as a p38 Regulated/Activated Protein Kinase (PRAK), activated by p38 MAPK and the atypical MAPKs ERK3 and ERK4. Although MK5 is expressed in the heart, its physiological function is just beginning to be studied. Herein, we studied the effects of chronic pressure overload induced by transverse aortic constriction (TAC) and the effects of myocardial infarction (MI) induced by permanent ligation of the left anterior descending coronary artery (LADL) in heterozygous mice for a functional knockout of MK5 (MK5). We also studied the role of MK5 in cardiac fibroblast function and in extracellular remodeling in healthy heart in vitro using MK5 wild type (MK5), haplodeficient (MK5), deficient (MK5), and siRNA-mediated knockdown (MK5-kd) fibroblasts. At twelve weeks of age, MK5 mice were smaller than age-matched wild-type littermates (MK5). Left ventricular end-diastolic diameter and systolic function were reduced in MK5 mice. Two weeks post-TAC, heart weight/tibia length ratios (HW/TL) were similarly and significantly increased in both MK5 and MK5 hearts. However, eight weeks post-TAC, HW/TL ratios were significantly lower in TAC-MK5 mice compared to TAC-MK5 mice. Thus, the progression of hypertrophy in response to chronic pressure overload was attenuated in MK5 hearts. Furthermore, two weeks of pressure overload induced increase in collagen type 1 α 1 (COL1A1) mRNA in MK5 mice and this increase was significantly attenuated in MK5 mice. As MK5 immunoreactivity was detected in cardiac fibroblasts but not myocytes, these findings suggest that MK5 within cardiac fibroblasts plays an important pro-fibrotic and pro-hypertrophic role in cardiac remodeling during chronic pressure overload. We then examined the effect of reduced MK5 expression on reparative fibrosis following MI. Mortality rates for MK5 and MK5 +/did not differ significantly over seven days post-MI. In contrast, mortality was higher in MK5 mice over twenty-one days. Systolic and diastolic functions were similarly impaired in both MK5 and MK5 mice post-MI. Scar area and scar collagen content were reduced in MK5 hearts eight days post-MI. Inflammatory cell infiltration was similar in both ligated groups whereas angiogenesis was
A new method to exfoliate Graphite oxide and application for synthesis Graphene by chemical method

 Mai Thanh Tam  Ha Thuc Chi Nhan  Ha Thuc Huy University of Science, VNU HCM (Received on March 20 th 2013, accepted on Jannuary 16 th 2015) ABSTRACT A new method to separate graphite oxide (GO) modified by polyethylene oxide (PEO) by the aid of ultrasonic radiation was developed. Modified GO (graphene oxide or single layer of graphite oxide) did not show not appear crystalline peak (d002) on the XRay and took the form of a single layer graphene oxide on the image AFM and TEM. The exfoliated graphene oxide was reduced (RGO) to graphene by the reducing agent system HI – Acetic acid (HI-AcOH). The sheet resistance of RGOHI-AcOH is about 120 Ω/sq in the form graphene paper. In addition, FTIR, UV-Vis and Raman spectra showed more clearly about characteristics of graphite oxide, graphene oxide and RGOHI-AcOH.
A highly efficient method for concentrating DNA from river water by combined coagulation and foam separation

ABSTRACT Both Escherichia coli and Enterococci were collected in foam within 7 min from 500 mL of bacteria-spiked water by coagulation and foam separation using ferric chloride and milk casein. These bacterial DNA isolated in the 100 µL of extract from the foam more than 87.5% recovery using the DNeasy PowerWater® Kit. To test this method with water from three natural rivers, 0.67–2.70 µg of DNA were concentrated in 100 µL of extract from 1,000 mL of river water. When the DNA extract was subjected to 16S rRNA gene sequencing analysis, information on the bacterial flora could be obtained.
Chitin Beads from Peneaus sp. Shells as
a Biosorbent for Methylene Blue Dye Removal

The adsorption potential of chitin, a polysaccharide found in the exoskeleton of shrimp, was evaluated using methylene blue cationic dye. Batch adsorption studies were done using a column by optimized bed height of 22.2 cm and retention time of 90 min. The alginate:chitin ratio was taken as 1:07 with 80 mgl-1initial dye concentration, and pH was maintained at 8. There was 90% adsorption of dye. Langmuir and Freundlich isotherms were studied along with the adsorption kinetics. The plots indicated that the data fitted Langmuir isotherm. The R2 is greater for pseudo second-order kinetics and Weber and Morris’ model on intra particle diffusion best fit this adsorption by chitin.
An Experimental Investigation of Pristine Barite Adsorption on Sodium Oleate and Sodium Palmitate

Characterization of the pristine barite mineral was established using a scanning electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Barite was applied for sodium oleate and sodium palmitate adsorption in aqueous solutions. Equilibrium adsorption data were fitted into two adsorption isotherms, three kinetic models and thermodynamic study. The concentration of the ion and pH in the solution proved to be a controlling factor in the adsorption process. Sodium oleate and sodium palmitate soaps adsorbed strongly onto the barite mineral at pH 9 and a temperature of 293k. They result was affected by the high bulk density and chemical resistance nature of barite indicated by successive increase in dosage amount. The effect of concentration and time typically gave a C-type adsorption isotherm. Adsorptive isotherm showed that sodium palmitate adsorption over natural barite was better described by the Langmuir adsorption isotherm while oleate desorption gave a good fitting with Freundlich isotherm. The adsorptive kinetics of sodium palmitate fitted well into pseudo 1 st order and 2nd order kinetics. Intra particle diffusion was not the rate-determining step. Thermodynamic study showed a physio-sorption that was exothermic. Hence the findings showed that pristine barite absorbs at optimum pH and temperature of 9 and 293K.
A Modified Method for Synthesis of Pyridoxylhistamine

In the course of the investigation in our laboratory on the reaction mechanism of pig kidney histaminase, an enzyme-substrate intermediate has been stabilized by reduction with sodium borohydride. To elucidate the binding site of the substrate to the enzyme, the reduced histaminase-histamine complex was hydrolyzed. The hydrolyzate was applied to electrophoresis and existence of pyridoxylhistamine II was confirmed. " The pyridoxylhistamine used as an authentic sample was
Modulating the immune response for in situ cardiovascular tissue engineering

• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers.
Differences in leaf pigments content and stomatadistribution across eight Hevea species

Photosynthesis is very important to plants in order to produce their own food. The study of this process involves wide range of field including morphology, physiology, and biochemical studies. In this study the analysis of leaf pigments content including chlorophyll and anthocyanin content and stomata distribution that directly and indirectly involve in photosiynthesis were conducted. Eight Hevea species that are H. brasiliensis, H. camargoana, H. guinensis, H. benthamiana, H. rigidifolia, H. nitida, H. spruceana, and H. pauciflora were analyzed. Between these eight species, H. brasiliensis has the highest chlorophyll content while H. rigidifolia with the lowest chlorophyll content. Meanwhile, the anthocyanin content was found to be the highest in H. guinensis (36.747 mg/L) and lowest in H. camagoana (15.1 mg/L). Stomata distribution that directly involves in gas exchange during photosynthesis was found to be high in H. camargoana (190.55/mm2) and low in H. rigidifolia (92.25/mm2). As a conclusion, this study can be used as a guideline to indicate the physiological state and functional of the plant leaves as a result from analysis of chlorophyll and anthocyanin content and also the distribution of stomato.
Proton Conductivity of Composite Polyelectrolyte Membranes with Metal‐Organic Frameworks for Fuel Cell Applications

The study of proton conductivity processes has gained intensive attention in the past decades due to their potential applications in chemical sensors, electrochemical devices, and energy generation. The scientific community has focused its efforts on the development of high‐performing polymeric membranes as proton exchange membranes (PEMs) for fuel cell (FC) applications. In particular, high conductivity at different humidity and temperature and enhanced chemical and mechanical stability under operative conditions are considered the main goals to be reached. The design of mixed‐matrix membranes (MMMs) based on conductive polymers and inorganic fillers is an approach commonly used for achieving materials with improved conductive and mechanical properties. In the last five years, the use of metal‐organic frameworks (MOFs) as fillers for conductive MMMs has rapidly grown for their intrinsic stability and structural versatility. The recent progress around the proton conductivity of MOF based composite membranes on PEMs for FC applications is critically reviewed.
An old oxovanadium(IV) complex of N-(salicylidene)sulfanilamide: theoretical validity of experimental observations

Abstract Sulfa drug Schiff base complexes of oxovanadium are counted among highly significant molecular scaffolds of industrial and medicinal relevance. In order to present a theoretical validation of our earlier reported complex of this sort herein, a comparative experimental theoretical investigation of N-(salicylidene)sulfanilamide Schiff base and its oxovanadium(IV) complex, [VO(sal-snm)2(H2O)] based on density functional theory calculations using the B3LYP as functional and 6-31++G(d,p) (for ligand)/LANL2DZ (for Vanadium) basis set is being reported. The calculated vibrational frequencies have been compared with experimental FT-IR spectra of the selected compounds. The Molecular geometry optimizations, frontier orbital analysis, hyperpolarizability calculations and molecular electrostatic surface potential (MESP) topologies of the title compounds have been sought in this work. From the molecular geometrical optimization of the oxovanadium(IV) complex a suitable octahedral structure has been confirmed. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecules. The Non-linear optical properties encompassing the applicability of electric dipole moment (μ), polarizability (α), mean polarizability (Δα) and hyperpolarizability (β0) values have been evaluated through quantum chemical calculations. Graphical Abstract
MoO3 films grown on polycrystalline Cu: Morphological, structural, and electronic properties

In this work, the authors investigated MoO3 films with thickness between 30 nm and 1 μm grown at room temperature by solid phase deposition on polycrystalline Cu substrates. Atomic force microscopy, scanning electron microscopy, and scanning tunneling microscopy revealed the presence of a homogenous MoO3 film with a “grainlike” morphology, while Raman spectroscopy showed an amorphous character of the film. Nanoindentation measurements evidenced a coating hardness and stiffness comparable with the copper substrate ones, while Auger electron spectroscopy, x-ray absorption spectroscopy, and secondary electron spectroscopy displayed a pure MoO3 stoichiometry and a work function ΦMoO3 = 6.5 eV, 1.8 eV higher than that of the Cu substrate. MoO3 films of thickness between 30 and 300 nm evidenced a metallic behavior, whereas for higher thickness, the resistance–temperature curves showed a semiconducting character.In this work, the authors investigated MoO3 films with thickness between 30 nm and 1 μm grown at room temperature by solid phase deposition on polycrystalline Cu substrates. Atomic force microscopy, scanning electron microscopy, and scanning tunneling microscopy revealed the presence of a homogenous MoO3 film with a “grainlike” morphology, while Raman spectroscopy showed an amorphous character of the film. Nanoindentation measurements evidenced a coating hardness and stiffness comparable with the copper substrate ones, while Auger electron spectroscopy, x-ray absorption spectroscopy, and secondary electron spectroscopy displayed a pure MoO3 stoichiometry and a work function ΦMoO3 = 6.5 eV, 1.8 eV higher than that of the Cu substrate. MoO3 films of thickness between 30 and 300 nm evidenced a metallic behavior, whereas for higher thickness, the resistance–temperature curves showed a semiconducting character.
Interaction of Beryllium Oxide with Hydrogen Plasma

Beryllium is considered a candidate material for the first wall of nuclear fusion plasma devices, e.g. ITER. For this application, the interaction of beryllium oxide with a D/T plasma is important with respect to beryllium as oxygen getter. Since it is not yet fully clear if and how much oxide will develop during operation, we investigated the interaction of beryllium samples with hydrogen plasma. Oxide layer thicknesses were measured by sputter depth profiling, using a high resolution Auger electron microscope. Exposure of beryllium samples with native oxide layers and pre-oxidized samples to hydrogen plasma resulted in an oxide layer of similar thickness, suggesting the development of an equilibrium state during exposure. In order to determine the relation between equilibrium oxide layer thickness and oxygen concentration in the plasma, the samples were exposed to hydrogen plasma with various additions of water vapour. The water vapour concentration was monitored with a quadrupol mass spectrometer. The experiments so far suggest that higher water vapour concentration results in a higher oxide layer thickness, as would be expected, and that oxide layer formation takes place down to a water vapour concentration of at least 3·10 -6 . An operation of beryllium liners as a non-evaporable getter (NEG) is therefore not to be expected. Getter activity linked to the transport of beryllium from the liner to some deposition areas is however possible.