Performance of Recalibrated Equations for the Estimation of Daily Reference Evapotranspiration

An accurate estimation of reference evapotranspiration (ET₀) is of paramount importance for many studies such as hydrologic water balance, irrigation system design and management, crop yield simulation, and water resources planning and management. In the present study, Blaney-Criddle, Jensen-Haise and Hargreaves (temperature based), Priestley-Taylor, Radiation and Makkink (radiation based) and, Pan Evaporation and Christiansen (pan evaporation based) methods have been evaluated and recalibrated with respect to FAO-56 Penman-Monteith method for estimating daily ET₀ in the semi-arid Tirupati, Nellore, Rajahmundry, Anakapalli and Rajendranagar sites of Andhra Pradesh, India. Recalibrated Blaney-Criddle (temperature based), Radiation (Radiation based) and Christiansen (Pan evaporation based) methods showed a satisfactory performance at the sites. Further, recalibrated Blaney- Criddle method showed relatively better performance than Radiation and Christiansen methods in the daily ET₀ estimation. Recalibrated Blaney- Criddle method may therefore be adopted at the sites selected for the present study and also at the sites with similar climatic conditions for satisfactory daily ET₀ estimation.     

Structural,optical and electrochemical properties of TiO2 nanoparticles synthesized using medicinal plant leaf extract

The flower like TiO₂ nanoparticles have been identified as potential electrode material for efficient next generation electrochemical energy storage devices. The present work reports, a novel green approach to synthesize high surface area TiO₂ nanoparticles using medicinal plant leaf extracts namely Ocimum Tenuiflorum Plant and Calotropis Gigantea Plant. The TiO₂ nanoparticles synthesized using Calotropis Gigantea plant confirmed rutile phase from X-ray powder diffraction and Raman spectra. The fourier transform infrared spectroscopy spectra of the sample indicate the presence of TiO₂ vibrational bonds. The field emission scanning electron microscopy images revealed that the flower like shape of nano-granules with an average granule size of 200 nm. The presence of Ti and O elements qualitatively confirmed using energy dispersive spectroscopy spectra, which shows the good stoichiometry in the sample. The flower like shapes with nano petals were further disclosed with the help of high resolution transmission electron microscopy. The corresponding optical band gap was observed to be 3.0 eV. The electrochemical investigations of the sample exhibited a high specific capacitance of 224 F g^-1 at 0.5 A g^-1 with 71% of capacitive retention after 5000 cycles.     

Design of two by three element fractal tree antenna array for WLAN and WiFi applications

For more antenna miniaturization, novel fractal tree geometry designed for 5 iterations using rectangular and triangular patches that allow decrease in the resonance frequency without occupying more space. Impedance Matching can be improved without changing the main beam direction or current distribution to five iterations with branching half angle of 60 degrees. The antenna fed by a Coaxial or probe feed to improve the narrow bandwidth of Fractal Antenna. The proposed antenna achieves a bandwidth of 31.5% for 10 dB return loss, covering the frequency range 2.4–3.6 GHz for WLAN and WiFi applications. The antenna gain of the fractal element is about 3 dBi. Array is designed to increase the gain and radiation energy. Arrays are configured at operating frequency of 2.4 GHz by using six elements to enhance the gain up to 11 dBi. The obtained gain and frequency are suitable for WLAN and WiFi applications.     

Numerical study of heat transfer in a wall of vertically perforated bricks: influence of assembly method

Vertically perforated bricks were developed with the view to building environmentally friendly houses since they make insulating materials unnecessary. Indeed, walls can be constructed without any other materials than clay and mortar. Furthermore, they offer better mechanical properties than horizontally perforated ones. However, heat transfer in this geometry, and particularly the influence of the assembly method, is not totally known. In this numerical study, we propose to verify that convection heat transfer is negligible in the perforations. This condition is necessary to increase the thermal resistance of the brick. We then show that a masonry bedded on several strips does not penalize the thermal performance of the wall. A particular study of the ruptures concludes that the convection present in these regions is a local phenomenon preferable to the thermal bridges caused by continuous mortar joints.     

Solid self microemulsification of Atorvastatin using hydrophilic carriers: a design

Context: Atorvastatin has a limited advantage to formulate oral dosage forms.

Objective: To enhance the solubility of Atorvastatin and to design the suitable solid self-microemulsifying drug delivery systems (S-SMEDDS)

Materials and methods: The clear and transparent self-microemulsifying drug delivery system (SMEDDS) were formulated using coconut oil and isopropyl myristate as lipid phases; Tween 80 as surfactant; PEG 400 and glycerin as co-surfactant at 2:1, 3:1, 1:2 and 1:3 ratio. The pseudo ternary phase diagrams were constructed to identify the microemulsion region. The SMEDDS were evaluated for zeta potential, poly dispersity index, globule size, pH, viscosity and drug release. The solid SMEDDS were developed by employing adsorption and melt granulation methods. The S-SMEDDS were evaluated for micromeritics, morphology, solid state property, reconstitution ability, drug release and stability.

Results: The micro formulations formed with particle size of 25?nm had shown a 3-folds rise in drug release. The solid SMEDDS had reconstituted to a good microemulsion rapidly in 1–3?min, with a release of 94.62% at the end of 30?min and behaved as immediate releasing capsules. Their shelf-life was found to be 1.3 years.

Discussion: The 1:3 ratio SMEDDS had shown more drug release owing to their less particle size. The solid SMEDDS had shown an increased dissolution profiles than atorvastatin. The solid state of the drug had changed in formulation inferring their enhanced solubility.

Conclusion: The solid form of atorvastatin liquid SMEDDS had been formulated successfully with enhanced shelf life and solubility.     

Comparative study on dielectric behavior in fresh and aged Na0.5Bi0.5(Ti,Fe,W)O3 thin films

Na_0.5Bi_0.5(Ti_0.90Fe_0.02W_0.08)O₃ (NBTFW) thin film was deposited on the ITO/glass substrate by chemical solution deposition. Microstructure, insulating and dielectric performances were measured and compared in fresh and aged samples. Both samples crystallize into phase-pure perovskite structures and possess smooth surfaces without any cracks. Lower leakage current density and relative dielectric constant can be obtained in aged NBTFW film compared to those for fresh one. At low voltage or high frequency, the fresh film exhibits a typical butterfly pattern of normalized dielectric constant–electric field curve, while the aged film shows an abnormal characteristic with two normal double–peaks shape. The related aging mechanism is discussed to be associated with the realignment of ${\mathrm{V}}_{\mathrm{O}}^{\cdot \cdot }-{\mathrm{Fe}}_{\mathrm{Ti}}^{\prime }$ defect dipoles along the spontaneous polarization via the migration of mobile oxygen vacancies.     

Preparation and characterization of manganese oxide/CNT composites as supercapacitive materials

Manganese oxide was synthesized and dispersed on carbon nanotube (CNT) matrix by thermally decomposing manganese nitrates. CNTs used in this paper were grown directly on graphite disk by chemical vapor deposition technique. The capacitive behavior of manganese oxide/CNT composites was investigated by cyclic voltammetry and galvanostatic charge–discharge method in 1 M Na₂SO₄ aqueous solutions. When the loading mass of MnO₂ is 36.9 μg cm^− 2, the specific capacitance of manganese oxide/CNT composite (based on MnO₂) at the charge–discharge current density of 1 mA cm^− 2 equals 568 F g^− 1. Additionally, excellent charge–discharge cycle stability (ca. 88% value of specific capacitance remained after 2500 charge–discharge cycles) and power characteristics of the manganese oxide/CNT composite electrode can be observed. The effect of loading mass of MnO₂ on specific capacitance of the electrode has also been investigated.     

Biosynthesis of titanium dioxide nanoparticles using bacterium Bacillus subtilis

The present study reports a low-cost, new material, eco-friendly and reproducible microbes Bacillus subtilis mediated biosynthesis of TiO₂ nanoparticles. Titanium dioxide nanoparticles synthesized from titanium as a precursor, using the bacterium, B. subtilis. The synthesized nanoparticles were characterized and confirmed as TiO₂ nanoparticles by using the UV spectroscopy, XRD, FTIR, AFM and SEM analysis. The morphological characteristics were found to be spherical, oval in shape, individual nanoparticles as well as a few aggregates having the size of 66–77 nm. The XRD shows the crystallographic plane of anatase of TiO₂ nanoparticles, indicating that nanoparticles structure dominantly correspond to anatase crystalline titanium dioxide.     

Extensions of the dynamic programming method in the deterministic and stochastic assembly-line balancing problems

The dynamic programming method which minimizes the number of stations for a given cycle time is extended here to solve two variants of the assembly-line balancing problem. The extended method minimizes cycle time for a given number of stations or, more generally, computes all nondominated pairs of cycle time and number of stations. The method is also applied to the stochastic case where minimizing critical cycle time, the number of stations and maximizing confidence level is desired.     

Facile synthesis of pseudocapacitive Mn3O4 nanoparticles for high-performance supercapacitor

In this work, a facile method to produce the ultrafine (4–14 nm) and mixed valence Mn₃O₄ nanoparticles from low-cost MnSiO₃ (manganese silicate) particles were introduced. The best NaOH concentration in hydrothermal treatment has been determined after a series of experiments. Also, the as-synthesized Mn₃O₄ material with good specific capacitance has been investigated attentively at a high mass loading (∼3 mg cm⁻²). The particles size and the pore size distribution is found to be refined and optimized, respectively. This increased the crystallinity and the capacitive contribution in the energy process. Thereby improving the rate capability and cycling stability, which result in significant improvement of specific capacitance (401 F g⁻¹ at 10 mV s⁻¹). The aqueous asymmetric supercapacitor device AC//Mn₃O₄ with a stable working voltage window up to 2.0 V has been fabricated, and it is found to have an energy density of 40.2 W h kg⁻¹ at 500 W kg⁻¹ power density. This could sustain 5000 cycles galvanostatic charge/discharge with 96.9% retention.