Detecting incipient cavitation by assessing low frequency acceleration and analysis of CMC

Cavitation is a common phenomenon in a fluid circuit especially wherever local pressure is lower than fluid saturated pressure. The cavitation negatively affects a fluid system and structure in different ways: i.e. erosion, flow rate reduction, noise and vibration. In order to diminish cavitation, adding some nanomaterials seem to be applicable in different ways. This research aims at assessing the effects of CMC (Carboxy methyl cellulose) additives on incipient cavitation by analyzing the resultant change in low frequency acceleration. Furthermore, this study attempts to examine the accuracy of low frequency acceleration for detecting incipient cavitation.     

Polyethylene-based nanocomposite: Structure and properties of poly(vinyl alcohol)/organofunctionalized Mg-doped fluorapatite hybrid

We report here the production and characterization of polymer nanocomposites (NC)s containing nanoceramics of organofunctionalized Mg-doped fluorapatite (MDFA) in a poly(vinyl alcohol) matrix. First, the MDFA materials were functionalized with N-trimellitylimido-L-leucine modifier through ultrasonic irradiation. The numerous experimental techniques like Fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis were applied to characterize the prepared materials. Thermal analysis of the obtained NCs showed an increase in thermal stability of the NCs when compared to the neat macromolecule.     

Preparation and evaluation of a new neurotensin analog labeled with 99mTc for targeted imaging of neurotensin receptor positive tumors

Neurotensin receptors are overexpressed in several human tumors and can be targets for tumors diagnosis and therapy. In this study, a new neurotensin analogue was labeled with ^99mTc via HYNIC and tricine/EDDA as coligands and investigated further. [HYNIC⁰, Gly⁷, Lys⁹, d-Tyr¹¹]-Neurotensin (7–13) was synthesized using a standard Fmoc strategy. Labeling with ^99mTc was performed at 100 °C for 10 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide was checked in the presence of humane serum at 37 °C up to 24 h. The receptor bound internalization and externalization rates were studied in neurotensin receptor expressing HT-29 cells. Biodistribution of radiopeptide was studied in nude mice bearing HT-29 tumor. Labeling yield of 98.6 ± 0.54 % (n = 3) was obtained corresponding to a specific activity of 81 MBq/nmol. Peptide conjugate showed good stability in the presence of human serum. The radioligand showed specific internalization into HT-29 cells (12.43 ± 0.52 % at 4 h). In biodistribution studies, a receptor-specific uptake was observed in neurotensin receptor positive organs so that after 1 h the uptakes in mouse intestine and tumor were 0.87 ± 0.16 and 0.63 ± 0.12 % ID/g respectively.     

[DBU][Ac]-catalyzed mild preparation of 6-amino-4-aryl-5-cyano-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole derivatives

We report a new, one-pot, efficient, four-component condensation of hydrazine hydrate, ethyl acetoacetate, arylaldehydes, and malononitrile in the presence of a reusable weakly basic ionic liquid, 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium acetate, as catalyst, for synthesis of 6-amino-4-aryl-5-cyano-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole derivatives under solvent-free conditions at room temperature. The method has several advantages, for example good yields, short reaction times, and simple work-up procedure.     

Total transparency of a two-moving-magnetized-plasma-layer structure

In the present Letter the transparency of a two-moving-magnetized-plasma-layer structure irradiated by an electromagnetic wave is investigated theoretically and its resonant conditions are determined. Here, the direction of the external magnetic field is normal to the plasma surface and two layers move with different velocities parallel to the interface. The effects of the external magnetic field, speed of plasma layers and the magnitude of the wave number component on transparency are simulated. These investigations for S-polarized and P-polarized electromagnetic waves have been done separately.     

Electrical properties and conduction mechanisms in La2/3Ca1/3MnO3 thin films prepared by pulsed laser deposition on different substrates

Perovskite manganite La_2/3Ca_1/3MnO₃ thin films were directly grown on MgO(100), Si(100) and glass substrates by pulsed laser deposition. From the XRD patterns, the films are found to be polycrystalline, single-phase orthorhombic. The metal–insulator transition temperature is 209 K for LCMO/MgO, 266 K for LCMO/Si and 231 K for film deposited on the glass substrate. The conduction mechanism in these films is investigated in different temperature regimes. Low-temperature resistivity data below the phase transition temperature (T _P) have been fitted with the relation \( \rho = \rho_{0} + \rho_{2} T^{2} + \rho_{4.5} T^{4.5} \) , indicating that the electron–electron scattering affects the conduction of these materials. The high-temperature resistivity data (T > T _P) were explained using variable-range hopping (VRH) and small-polaron hopping (SPH) models. Debye temperature values are 548 K for LCMO/Cg, 568 K for LCMO/Si and 508 K for LCMO/MgO thin films. In all thin films, the best fitting in the range of VRH is found for 3D dimension. The density of states near the Fermi level N (E _F) for LCMO/MgO is lower due to the prominent role of the grain boundary in LCMO/MgO and increase in bending of Mn–O–Mn bond angle, which decreases the double exchange coupling of Mn³⁺–O²–Mn⁴⁺ and in turn makes the LCMO/MgO sample less conducting as compared to the other films.     

Binodal curve measurements for (water + propionic acid + dichloromethane) ternary system by cloud point method

The binodal (solubility) curves and tie line data for ternary systems of (water + propionic acid + dichloromethane) at 91.3 kPa and T = (277.15, 284.15, and 294.15) K are reported. The binodal curve results were determined by cloud point measurements method. A simple titration method has been used for determining of the concentration of propionic acid in the both liquid phases at equilibrium. The results obtained were successfully correlated with the UNIQUAC activity coefficient model. The deviations between experimental and calculated compositions in both phases for the ternary system using this model are reported. The partition coefficients of propionic acid and the selectivity factor of dichloromethane for extracting of propionic acid from water were calculated and are reported. The phase diagrams for the ternary system studied including both the experimental and correlated tie lines are presented.