Miracle-dz/UniFAR-FTUs huggingface dataset:
One-Dimensional Gas Flow Analysis of the Intake and Exhaust System of a Single Cylinder Diesel Engine

In order to design a diesel engine system and to predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. Gas flow analysis in a three-dimensional (3D) format needs a high-resolution workstation and an enormous amount of time for analysis. Calculation using the method of characteristics (MOC), which is a gas flow analysis in a one-dimensional (1D) format, has a fast calculation time and can be analyzed with a low-resolution workstation. However, there is a problem with poor accuracy in certain areas. It was assumed that the reason was that 1D could not implement the shape. The error that occurs in the shape of the bent pipe used in the intake and exhaust ports of the diesel engine was analyzed and to find a solution to the low accuracy, the results of the experiment and 1D analysis were compared. The discharge coefficient was calculated using the average mass flow rate, and as a result of applying it, the accuracy was improved for the maximum negative pressure by 0.56–1.93% and the maximum pressure by 3.11–7.86% among the intake pipe pressure results. The difference in phase of the exhaust pipe pressure did not improve. It is considered as a limitation of 1D analysis that does not improve even by applying the discharge coefficient. In the future, we intend to implement a bent pipe that cannot be realized in 1D using a 3D format and to prepare a method to supplement the reliability by using 1D–3D coupling.
A critical comparison of MINDO/3, MNDO, AM1, and PM3 for a model problem: Carbon clusters C2‐C10. An ad hoc reparametrization of MNDO well suited for the accurate prediction of their spectroscopic constants

Dissociation energies and potential energy surface features for the carbon clusters C2 to C10 are compared with ab initio or experimental results for the semiempirical methods MINDO/3, MNDO, AM1, and PM3. Quite surprisingly, MINDO/3 gives a rather good account of the various structures and electronic states, unlike the other three methods. MINDO/3 tends towards systematic overestimates of binding energies, the other methods to systematic gross underestimates. Reparametrization of the diatomic parameters α, βs, and βp for exact reproduction of the experimental data for C3 results in much improved values for binding energies, but fails to correct the state splittings. Also reparametrizing Uss, Upp, ζs, and ζp to reproduce the ab initio linear‐rhombic energy difference in C4 results in a much improved description of the other states. For the linear structures, computed harmonic frequencies with the latter parameters are in surprisingly good agreement with experimental or correlated ab initio data, where available; experimental values are consistently overestimated by about 40 cm−1. Other results are comparable in quality to good ab initio treatments. The experimental IR bands at 2128 and 1892 cm−1, formerly assigned to C9, should be reassigned to linear C7. The intense 1997 cm−1 feature almost certainly belongs to C9; bands at 1952 and 1197 cm−1 both belong to linear C6. Tentative assignments of bands in the 1600–1850 cm−1 region to various cyclic structures of C6, C8, and C10 have been made. As such, this suggests a new and promising procedure for the theoretical study of large molecules in general, and of large clusters in particular.
Fractal analysis of electrical trees

Recently, fractal characteristics in pattern formation have been attracting much attention. A number of books and papers have been published on the fractal analysis of random patterns or structures occurring in nature. The geometrical patterns of dielectric breakdown, which include lightning, surface discharges and electrical trees, are known to be of a fractal nature. Their fractal patterns can be analyzed numerically using fractal dimensions. In this paper, a survey of the fractal analysis of electrical trees, both in experiment and in computer simulation, is given. Several methods for estimating the fractal dimension are summarized. The stochastic models for discharge patterns based on computer simulation are also summarized. Fractal analysis of real electrical trees in polymeric insulating materials is reviewed. For the experimental tree patterns, the fractal analysis of the projected 2-D and the reconstructed 3-D patterns is presented.
Raman and infrared spectroscopic studies of the uranyl ion: the symmetric stretching frequency, force constants, and bond lengths

The symmetric stretching frequency of the uranyl ion has been measured for some uranyl compounds with the use of Raman excitation. The symmetric and asymmetric stretching frequencies have been used in the calculation of stretching and interaction force constants from which have been derived an estimate of the uranium–oxygen bond lengths by use of Badger's rule. These bond lengths are in good agreement with the few crystallographic data available. Previous calculations of force constants have ignored interaction constants, and bond-length determinations have relied upon an estimate of the bending frequency of the uranyl ion or upon force constants derived from the asymmetric stretching frequency only. The present measurements confirm that the uranyl ion is linear or very nearly so. The overtone and combination bands of some uranyl nitrate complexes have been re-investigated.
THREE-DIMENSIONAL QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP AND COMPARATIVE MOLECULAR FIELD ANALYSIS OF CYP450 ENZYME SYSTEM INHIBITORS

"cytochrome P450" family of enzymes are present in every cell and are responsible for biotransformation of drugs from active to inactive metabolites that are readily excreted by the body. , the rapid metabolism of certain drugs by the CYP450 enzyme system can markedly alter their pharmacokinetic (PK) profile and can result in sub-therapeutic plasma levels of those drugs over time. To understand the ligand structural requirements and to enhance inhibitory potency for new ligands against CYP-450 enzyme system, 3D– QSAR comparative molecular field analysis (CoMFA) study was carried out on a series of 2-[3-(4-fluorobenzyl)-5-pyridin-4-yl-1H-pyrazol-1-yl] derivatives, as selective CYP450 enzyme system inhibitors. Comparative molecular field analysis (CoMFA) QSAR models were computed with Sybyl 6.7v. The developed model gave leave–one–out (LOO) cross–validated correlation coefficient q2 value of 0.844, non–cross–validated correlation coefficient r2 value of 0.992, and the predicted correlation coefficient r2 pred was found to be 0.781. The QSAR model gave satisfactory statistical results in terms of q2 and r2 values. The CoMFA model provided the most significant correlation of steric and electrostatic fields with biological activities. The information derived from this study provides a tool for guiding further structural modification to obtain selective inhibitors of CYP450.
Palladium Nanoparticles as Efficient Catalysts for Suzuki Cross-Coupling Reactions

In this Perspective, we discuss some of the most significant aspects in the development of nanosized catalysts for Suzuki cross-coupling reactions. Thus, the effect of the size and shape of Pd nanoparticles on the catalytic activity, together with their stability, recycling ability, and the influence of different reaction parameters, will be brought up for consideration. Furthermore, a comprehensive discussion on the homogeneous or heterogeneous nature of the mechanism for Pd-catalyzed carbon–carbon bond-forming reactions will be conducted. Understanding where the active sites are and how the reaction takes place at those sites is the key for the design of new and more effective nanocatalysts.
Synthesis and structures of helical and meso-helical coordination polymers directed by the conformation restriction of flexible/angular pyridine-containing ligands

Six coordination polymers, {[Ni(L1)2(H2O)2]·(H2O)4}n (1), {[Co(L1)2(H2O)2]·(H2O)4}n (2), [Co(L2)2]n (3), {[Hg3(L3)2Cl6]·(CH3OH)4·(H2O)2}n (4), {[Hg3(L3)2I6]·(H2O)3}n (5) and {[Zn3(L3)2Cl6]·(CH3OH)2·(H2O)4}n (6) (L1 = 3,5-bis(4-pyridylmethoxy)benzoate, L2 = 3,5-bis(3-pyridylmethoxy)benzoate, L3 = pyridin-4-ylmethyl-3,5-bis(pyridin-4-ylmethoxy)benzoate were synthesized under hydrothermal (solvothermal) conditions and structurally determined by single-crystal X-ray diffraction. 1 and 2 are isomorphous, exhibiting a double helical chain, in which L1 acts as a bidentate ligand to bridge two metal ions using the monodentate carboxylate group and one pyridyl arm. In complex 3, each L2 performs as a tridentate ligand using the chelating carboxylate group and one pyridyl arm to link two metal ions, forming a 2-D homochiral layer in which neighbouring helical chains with the same chirality are interlinked through metal ions. Complexes 4, 5 and 6 are constructed from ligand L3, which acts as a tridentate ligand to bridge three metal ions via three pyridyl arms. 4 and 5 are 1-D meso-helical chains but 6 is a zigzag chain. In 4, each HgCl2 connects with two L3 to form a helical subunit; neighbouring subunits are in opposite helicity and mediated by two other HgCl2 to form a chair-shaped conformation and this is extended into a double-chain network. 5 contains a helical half-a-turn reversal, which is constructed with two L3 linking two HgI2, showing a shell-like conformation. Complex 6 also contains shell-like conformations similar to those in 5, but it is a zigzag chain. The results indicate that the flexible/angular ligands can adopt different conformations, while the conformation restriction of flexible/angular ligands, together with the coordination preferences of the metal centers, plays a critical role in the construction of these novel coordination polymers.
Modified embedded-atom method calculation for the Ni–W system

A semi-empirical interatomic potential of the Ni–W system was developed using a modified embedded-atom method (MEAM) formalism including second-nearest-neighbor interactions. The cross potential was determined by fitting physical properties of tetragonal Ni4W available in the literature. The MEAM potential was used to predict phase stabilities, lattice constants, and bulk moduli of nonequilibrium and equilibrium phases in the Ni–W system. The results were in good agreement with experimental information or first-principles calculation.
Fibrillar Structure in Aqueous Methylcellulose Solutions and Gels

The fibrillar structure of aqueous methylcellulose (MC) gels was probed using a combination of small-angle neutron scattering (SANS), ultra-small-angle neutron scattering (USANS), and cryogenic transmission electron microscopy (cryo-TEM). The effect of molecular weight (Mw) and concentration on the gel structure was explored. The fibrillar morphology was consistently observed at elevated temperatures (≥70 °C), independent of concentration and Mw. Moreover, the fibril dimensions extracted from SANS by fitting to a scattering function for semiflexible cylinders with disperse radii revealed that the fibril diameter of ca. 14 ± 1 nm is constant for a mass fraction range of 0.01%–3.79% and for all Mw investigated (49–530 kg/mol). Comparison of the measured SANS curves with predicted scattering traces revealed that at 70 °C the fibrils contain an average volume fraction of 40% polymer. Taking linear combinations of low temperature (solution state) and high temperature (gel state) SANS traces, the progression of.
The role of Donnan effect in kraft cooking liquor impregnation and hot water extraction of wood

Abstract In this article, a phenomenological model is proposed for alkali impregnation and hot water extraction of wood. Elementary reaction kinetics, ion exchange (IE) equilibrium, and mass transfer rates are considered in the model. IE is a consequence of the dissociation of the covalently bound uronic acid and phenolic groups in the wood fiber wall (FW). Due to this effect, the molality of cations is higher in the FW liquid than in the liquid external to the FW, whereas the opposite is true for anions. For the development of kinetic models under the participation of hydroxyl and hydrogen ions, the estimation of their molalities in these two liquid phases is crucial because of their ubiquitous presence in chemical reactions. This study applies a recently developed physicochemical modeling environment in which alkali impregnation and hot water extraction processes are considered. The simulations revealed that the IE effect is significant and affects the chemical reaction kinetics in both processes in focus. Furthermore, the IE effect does not remain constant but varies as a function of treatment time.
Implementation of remotely operated vehicle for direct inspection of reactor pressure vessel and other water-filled infrastructure

To reduce the irradiation exposure time of inspection personnel inspecting the reactor pressure vessel and other water-filled infrastructure during overhaul period, a remotely operated vehicle (ROV) is developed to help monitor the underwater environment and salvage small parts like bolts and nuts in the reactor pool and other water-filled infrastructure of the nuclear power plants. It is designed to be compact, light and radiation resistant. The depth control strategy based on fuzzy proportion integration differentiation is proposed for the ROV to suspend at any depth of the reactor pool. And the integrated navigation algorithm based on the Kalman filter fuses data from sensors, including sonar, depth gauge, three-axis accelerometer, three-axis gyroscope and three-axis magnetometer. Radiation testing has been conducted to verify ROV's ability to work in the reactor pool and other water-filled infrastructure under the environment of high irradiation. Eventually, field experiment was conducted in the reactor simulation pool of the Daya Bay Nuclear Power Plant, and the result verifies the effectiveness of the depth control algorithm, the integrated navigation algorithm and also the leak tightness of the ROV.
An extension of the canonical ensemble molecular dynamics method

The canonical ensemble molecular dynamics method proposed by Nose (1984, Molec. Phys., 52, 255 and 1984, J. chem. Phys., 81, 511) is extended to include more than one temperature control variable. This extension makes it possible to control temperatures of different degrees of freedom (e.g. translation and molecular rotation) separately.
DEVELOPMENT AND IN VITRO EVALUATION OF GASTRORETENTIVE HIGH DENSITY TABLET OF PROPAFENONE HCL

A novel Propafenone HCl gastric-resident tablet was developed. A controlled release matrix tablet was prepared by using various controlled release polymers i.e. HPMC E5 and HPMC K100M. Pharmaceutical zinc oxide powder was used as a density-increasing agent. The formulations were evaluated for pharmacopoeial quality control tests and all the physical parameters evaluated were within the acceptable limits. Prepared high density tablet showed density up to 1.63 gm/cm3 which is higher than the gastric fluid. Also it shows good dimensional stability till the 12 h. In vitro release study shows the good drug release up to the 12 h. Stability studies were carried out on the optimized formulation for period of 3 months at 400c / 75%RH. Finally it was observed that there was no change in physiochemical and physical properties as well as in drug release profile even after storage at 45 °C and 75 % for three months. Zinc oxide increases the system density, making the system resident in stomach to prolong the drug delivery time in absorption zone.
Hollow‐cathode‐enhanced magnetron sputtering

A hollow cathode arc electron source has been added to a conventional planar magnetron sputtering system to form a triode magnetron. The hollow cathode source was chosen in place of a filament for high emission current at low energy, lifetime, and ease of operation in high magnetic fields and reactive gases. The electrons emitted from the hollow cathode produced additional gas ionization, resulting in a denser plasma at constant voltage. Up to 60% of the hollow cathode emission current could be directly coupled into the discharge current of the magnetron. Increases in the discharge current and the deposition rate of up to 10× were recorded over the conventional magnetron at the same voltage. The hollow cathode enhanced magnetron discharges were also capable of high current operation at voltages down to 20 V, which is below the sputter threshold. The pressure of operation could also be reduced significantly, and the magnetron could be operated at full power as low as 5×10−5 Torr in argon.
FORMATION OF EXTENDED DEFECTS IN LiF IRRADIATED WITH 3He AND 4He IONS I. Manika1, R.Zabels1, J.Maniks1, K.Schwartz2, R. Grants1, T.Krasta1, A.Kuzmins1

Influence of the irradiation with 13.5 MeV 3He and 5MeV 4He ions on the micro-structure and mechanical properties of LiF single crystals was studied. The depth profiles of nanoindentation, dislocation mobility, selective chemical etching and photoluminescence served for the characterization of damage. Strong ion-induced increase of hardness and decrease in dislocation mobility at the stage of track overlapping due to accumulation of dislocations and other extended defects was observed. At high fluences (1015 ions/cm2) the hardness saturates at about 3.5 GPa (twofold increase in comparison to a virgin crystal) thus confirming high efficiency of light projectiles in modifications of structure and properties. The depth profiles of hardness indicate on a notable contribution of elastic collision mechanism in the damage production at the end-ofrange region. The effects of ion-induced increase of hardness and decrease of dislocation mobility are observed also beyond the ion range and possible mechanisms of such damage are discussed. Highlights  The depth profiles of damage in LiF irradiated with 3He and 4He ions were studied.  High-fluence irradiation creates dislocation-rich structure and induces strong hardening.  Changes of LiF structure and properties were observed also beyond the ion range.  Mechanisms of damage beyond the ion range are discussed.
Preparation of antibodies and development of enzyme-linked immunosorbent assay for nonylphenol

Polyclonal rabbit antibodies against nonylphenol (NP), the main product of nonionic surfactants destruction, were obtained and applied for immunoenzyme assay (ELISA). Two approaches to immunogen synthesis were compared. The first was direct coupling of a mixture of NP isomers to the carrier protein by Mannich reaction. The second was formation of amide bonds between 7-(p-hydroxyphenyl)heptanoic acid (HHA), a linear carboxylated analog of NP, and the carrier protein. Anti-HHA antibodies showed a low affinity to technical NP, whereas with Mannich synthesis it was possible to generate antibodies specific to branched NP molecules. An indirect competitive ELISA was developed based on the anti-NP antibodies. The detection limit of the analysis is 10 ng/mL, with a total duration of around 3 h. The developed ELISA can be applied for group-specific determination of nonionic surfactants and their toxic metabolites. The possibility of NP detection in environmental water matrices using the proposed ELISA without loss of sensitivity is explored.
Synthesis, antimicrobial potential and toxicological activities of Ni(II) complex of mefloquine hydrochloride

Transition metal complex of Ni(II) with mefloquine hydrochloride (antimalaria drug) was synthesized using a template method. Chemical analysis including conductivity measurements and spectroscopic studies were used to propose the geometry and mode of binding of the ligand to metal ion. From analytical data, the stoichiometry of the complex has been found to be 1:1. Infrared spectral data also suggest that the ligand (mefloquine hydrochloride) behaves as a tridentate ligand with N:N:O donor sequence towards the metal ion. The complex generally showed octahedral coordinate geometry. Molar conductance of 10-2 mol dm-3 methanol solution of the complex indicated non-electrolytic nature of metal complex. It also revealed that the ligand anions were covalently bonded to the complex. In vivoevaluation of antimalarial studies of the metal complex shows greater activities when compared to the free ligand. Mefloquine and its metal complex increased significantly (p < 0.05) serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) and significantly reduced these enzymes in the liver and kidney when compared to the control. This revealed that both mefloquine and its metal complex might show toxicity particularly on the liver and kidney with the metal complex group being mild. Key words: Transition metal, antimicrobial, antimalarial drug, complexation, toxicological studies.
Reduced surface defects of organometallic perovskite by thermal annealing for highly efficient perovskite solar cells

The surface defects of the organometallic perovskite play an important role in the photovoltaic performance of solar cells, which depress the conversion efficiency and cause photocurrent hysteresis. As a key step in fabricating perovskite solar cells, the heating step possibly modifies the surface defects, which in turn leads to the modified device performance. In this context, the surface defects of the organometallic perovskite (CH3NH3PbI3) and their modification by thermal annealing are investigated. It is revealed that the surface defects create electron traps which can be reduced by thermal annealing. Consequently, the perovskite solar cells exhibit improved conversion efficiency from 10.9% to 17.1% with the thermal annealing temperature of the perovskite increasing from 60 °C to 130 °C. The photocurrent hysteresis of the solar cells is also subdued. This work provides further insights into the function of thermal annealing by modifying surface defects, which also favors the exploration of the perovskite solar cells with high-efficiency and eliminated photocurrent hysteresis.
Design and Synthesis of Nucleoproline Amino Acids for the Straightforward Preparation of Chiral and Conformationally Constrained Nucleopeptides

A straightforward synthesis of orthogonally protected nucleoproline (Nup) amino acids and their coupling to oligomers are described. A key step is the attachment of alkynylated nucleobases to Fmoc-protected 4-azidoproline (Fmoc-Azp-OH) by a Cu-catalyzed 1,3-dipolar cycloaddition (‘click reaction’). The developed protocol allows preparation of the nucleoprolines in scales of >30 g. Solid-phase peptide synthesis proved to be straightforward with these Nup amino acids. The resulting oligonucleoproline peptides adopt defined helices, are very well H2O soluble, and show comparable cell-penetrating properties as recently reported α-nucleoalanine peptides.
Microbubble efficiency during fast boiling growth

The microboiling in confined spaces is characterized through bubble area measurements for enclosed small planar heaters ( 41 µm x 45 µm). A laser visualization technique is used to measure the bubble area viewed from above. The bubbles are generated in deionized water by heating pulses of power inputs (2.6-3.7 W) and total energy releases (8.6-13.9 µJ). The bubble lifecycle lasts for 10 µs - 16 µs. Direct observations of bubble area show a rapid bubble film growth followed by a volumetric growth, subsequent collapse, and bubble regrowth. The bubble vapor pressure, generated mechanical power, and bubble efficiencies at different energy and heating rate conditions were calculated using a hemispherical cap model for the bubble. The two characteristic lengths r 1 and r 2 of the hemispherical cap relate the extent of the film and the volumetric growth. The effective radius of the bubble as viewed from above was fitted with a linear growth rate during the film growth phase. As the bubble reached the maximum area, the effective radius of the volume was approximated by either a linear radial growth rate, t, or a square root growth rate, t 1/2 . Using this model pressure calculations result in values up to 400x10 3 Pa and conversion efficiency to mechanical work up to 0.20%