Direct Equations for Hydraulic Jump Elements in Rectangular Horizontal Channel

Many problems in the design of stilling basins require a knowledge of various elements of a hydraulic jump with known values such as discharge intensity and the energy loss in the jump. Even for a simple case of a rectangular horizontal channel the solutions of equations involve tedious methods of trial and error. In this paper, direct explicit empirical equations for prejump and postjump depths and specific energies in a rectangular horizontal channel have been developed. These present forms of equations for hydraulic jump elements having very high accuracy and are applicable for a very wide range of values of discharge intensity and head loss without any limitations in comparison to other methods attempted so far.     

Fortran IV program to compute apparent resistivity of a perfectly conducting sphere buried in a half-space

A FORTRAN IV program is presented that computes apparent resistivity of a perfectly conducting sphere buried in a half-space at any depth and for any electrode configuration. The program is based on solution of the problem by the method of images.     

Optical characteristics of Eu(III) doped MSiO<Subscript>3</Subscript> (M = Mg,Ca, Sr and Ba) nanomaterials for white light emitting applications

A series of Eu(III) doped MSiO₃ (M = Mg, Ca, Sr and Ba) nanomaterials of high color purity were prepared using sol–gel technique at 950 °C. Samples were further reheated at 1050 and 1150 °C for 1 h in muffle furnace to study the effect of temperature on the structural aspects and optical characteristic of prepared materials. X-ray diffraction study was used to know the crystal structure of synthesized silicate phosphors. All the prepared materials existed in the single phase and dopant ion have no influence on the crystal structure of host materials. Under 395 nm excitation, photoluminescence emission spectra of silicate materials showed the characteristic red emission in 610–615 nm region due to the electric dipole (⁵D₀ → ⁷F₂) transition of europium(III) ion. Color coordinate values of these materials were located in the red region of Commission Internationale de I’Eclairage triangle. Fourier transform infra red spectroscopic studies were used to know the structure and bonding present in these phosphors. Transmission electron microscopic confirmed that the particle size of prepared nanomaterials exist in the nano range. The results suggested that these red emitting phosphors could be useful for generation of white-light emitting diode applications.     

Laboratory evaluation of four rodenticides admixed in a cereal-based bait against commensal rat, Rattus rattus (L.) (Rodentia : Muridae : Murinae)

The bio-efficacy of a cereal-based bait formulated with two acute rodenticides, fluoroacetamide and zinc phosphide and two second generation anticoagulants, bromodialone and difethialone at different concentrations was evaluated against laboratory-bred wild type rats, Rattus rattus. Bait containing 2% fluoroacetamide and incorporating edible green colour 0.025% and human feeding deterrent denatonium benzoate 0.001% produced complete mortality in 6 d and was considered to be the most effective.     

Sulphidation studies of Fe—15Cr—4Al alloy in H2—H2S environment at 850°C

The sulphidation behaviour of Fe—15Cr—4Al alloy has been investigated under low sulphur vapour pressure of 10^?9 to 10^?3 atm in the temperature range of 700–1000°C. Distinct changes in sulphide scale morphology were observed with the increase of partial vapour pressure of sulphur (ps₂). Triplex and duplex sulphide layers were observed at higher and lower ps₂ respectively. Parabolic rate constants of sulphidation of this alloy are strongly dependent on ps₂ and activation energies of the order of 83,6 kJ/mole suggesting diffusion of iron as a rate controlling step.     

Heat-Resistant,Robust, and Hydrophilic Separators Based on Regenerated Cellulose for Advanced Supercapacitors

Separators in supercapacitors (SCs) typically suffer from defects of low mechanical property, limited ion transport, and electrolyte wettability, and poor thermal stability, impeding the development of SCs. Herein, high-performance regenerated cellulose (RC) based separators are designed that are fabricated by effective hydrolytic etching of inorganic CaCO₃ nanoparticles from a filled RC membrane. The as-prepared RC separator displays excellent comprehensive performances such as higher tensile strength (75.83 MPa) and thermal stability (200 °C), which is superior to commercial polypropylene-based separator (Celgard 2500) and sufficient to maintain their structural integrity even at temperatures in excess of 200 °C. Benefiting from its hydrophilicity, high porosity, and outstanding electrolyte uptake rate (208.5%), the RC separator exhibits rapid transport and permeability of ions, which is 2.5× higher than that of the commercial nonwoven polypropylene separator (NKK -MPF30AC-100) validated by electrochemical tests in the 1.0 m Na₂SO₄ electrolyte. Results show that porous RC separator with unique advantages of superior electrolyte wettability, mechanical robustness, and high thermal stability, is a promising separator for SCs with high-performance and safety.     

Microstructure and Polarization Studies on Interlayer Free La0.65Sr0.3Co0.2Fe0.8O3–δ Cathodes Fabricated on Yttria Stabilized Zirconia by Solution Precursor Plasma Spraying

Nano‐structured cathodes of La_0.65Sr_0.3Co_0.2Fe_0.8O_3–δ (LSCF) are fabricated by solution precursor plasma spraying (SPPS) on yttria stabilized zirconia (YSZ) electrolytes (LSCF‐SPPS‐YSZ). Phase pure LSCF is obtained at all plasma power. Performances of LSCF‐SPPS‐YSZ cathodes are compared with conventionally prepared LSCF cathodes on YSZ (LSCF‐C‐YSZ) and gadolinium doped ceria (GDC) (LSCF‐C‐GDC) electrolytes. High R_p is observed in the LSCF‐C‐YSZ (∼42 Ohm cm² at 700 °C) followed by LSCF‐C‐GDC (R_p ∼ 1.5 Ohm cm² at 700 °C) cathodes. Performance of the LSCF‐SPPS‐YSZ cathodes (R_p ∼ 0.1 Ohm cm² at 700 °C) is found to be even superior to the performance of LSCF‐C‐GDC cathodes. High performance in LSCF‐SPPS‐YSZ cathodes is attributed to its nano‐structure and absence of any interfacial insulating phase which may be attributed to the low temperature at the interaction point of LSCF and YSZ and low interaction time between LSCF and YSZ during SPPS process. In the time scale of 100 h, no change in the polarization resistances is observed at 750 °C. Based on the literature and from the present studies it can be stated that SOFC with YSZ electrolyte and LSCF‐SPPS‐YSZ cathode can be operated at 750 °C for a longer duration of time and good performance can probably be achieved.