Effect of Sm Doping on Structural and Dielectric Properties of CoFe2O4 Ferrite

Samarium doped cobalt ferrite, CoSmxFe2 – xO4 in which x varies as 0.0, 0.1, 0.3 and 0.5 were synthesized by conventional solid state reaction method. The impact of samarium doping on structural and dielectric properties is studied. The phase formation is confirmed by using XRD technique. The reflection peak broadening increases with increase in Sm concentration. The grain size is calculated by using scanning electron microscope image. The variation in dielectric constant (ɛʼ) and dielectric loss (tanδ) as a function of frequency in the range 20 Hz to 1 MHz is studied. The dielectric constant is enhanced with increase in Sm concentration and decreases with increase in frequency

Thermodynamic analysis of EMISE-Water as a working pair for absorption refrigeration system

In this paper, thermodynamic analysis of novel ionic liquid 1 Ethyl-3-methylimidazolium ethyl sulphate (EMISE) as absorbent and water as green refrigerant for absorption refrigeration system (ARS) is performed. Thermodynamics excess properties like excess Gibbs free energy (GE), excess enthalpy (hE) and equilibrium Duhring's plot (P-T-x1) of EMISE-H2O binary mixture are assessed using non-random two liquid (NRTL) activity coefficient model for composition x1 of 0.45-1. The performance of single effect ARS with SHE are mathematically modeled and simulated by applying first and second laws (exergy analysis) of thermodynamics. Simulated results of ARS are compared with other widely used working fluids and revealed higher COP of 0.66 for EMISE-H2O in comparison to NH3-H2O but lower than LiBr-H2O. In addition, the deviation in the COP and ECOP with the generator temperatures are compared for the evaporation temperature of 5, 10, 15 C. Result showed noticeable difference between the optimum generator temperature based on COP and ECOP. This indicates the exergy analysis is used for evaluation of ARS and selection of heat source supply temperature obtained from waste heat and renewable solar energy.Scopu

Experimental Investigation of Isothermal Vapor-Liquid Equilibrium and Estimation of Excess Thermodynamic Properties (hE) of CHO2K-H2O from 278.15 to 423.15 K

In this paper, vapor liquid equilibrium (VLE) of a binary mixture, potassium formate-water (CHO2K-H2O), was measured experimentally using a dynamic moving type VLE setup in the temperature range of 313.15 to 393.15 K. Overall, large vapor pressure data points generated for the mole fraction of CHO2K from 0.023 to 0.461 and the solution temperature up to 423.15 K were used to correlate the local composition-based activity coefficient model (NRTL model). The data obtained via the thermodynamic model fitting shows good agreement with the experimental VLE data with overall average relative deviation of 2.15% and root-mean-square deviation of 0.25%. The obtained results further indicate that the binary mixture exhibits a negative deviation from the Raoult's law, which is an important characteristic of the working fluid used for a heat-activated vapor absorption system (VAS). Therefore, the CHO2K-H2O mixture can be considered as an alternative working pair that will overcome the limitations allied to the crystallization and corrosion of the commercial working fluids mainly lithium bromide-water (LiBr-H2O). The fitted nonrandom two-liquid model was further utilized to determine the excess thermodynamic properties, solution enthalpy, solution entropy, and equilibrium P-T-x (Duhring) plot.G.D.T. gratefully acknowledge the British Petroleum (BP) International, UK, for providing fellowship during his Ph.D. research work.Scopu

Understanding ethanol hydrogen abstraction mechanism on CuNi catalyst

In this work we report the synthesis of copper oxide nanoparticles using solution combustion synthesis. These nanopowders are used as catalyst in ethanol decomposition reaction for hydrogen production. In situ study of ethanol decomposition has been conducted in FTIR using DRIFTS reactor at temperature of 50°C and 400°C over the reduced catalyst obtained after passing H2 at 300°C for one hour. XRD, SEM and TEM analysis were conducted to identify the phase and morphology of catalyst before and after reaction.Qatar Foundation;Qatar National Research Fund;Qatar UniversityScopu

Understanding ethanol hydrogen abstraction mechanism on CuNi catalyst

In this work we report the synthesis of copper oxide nanoparticles using solution combustion synthesis. These nanopowders are used as catalyst in ethanol decomposition reaction for hydrogen production. In situ study of ethanol decomposition has been conducted in FTIR using DRIFTS reactor at temperature of 50°C and 400°C over the reduced catalyst obtained after passing H2 at 300°C for one hour. XRD, SEM and TEM analysis were conducted to identify the phase and morphology of catalyst before and after reaction.Qatar Foundation;Qatar National Research Fund;Qatar UniversityScopu

Study of reaction mechanism in solution combustion synthesis of transition metals

In this paper, we investigate the reaction mechanism followed during the solution combustion synthesis of transition metals (Cu, Ni and Co) and their alloys. Metal nitrates were mixed with a choice of fuel (glycine, and urea) and mixed in deionized water to get a homogeneous mixture of solution with uniform properties. The solution thus obtained is heated to initiate the highly exothermic combustion reaction resulting in the synthesis of metals/metal-oxides. TGA-DTA analysis of the reactants (metal-nitrates, fuel, and cellulose) along with the XRD of the final products obtained helped in deducing the reaction mechanism.Scopu

High-throughput root phenotyping : opportunities and challenges for the adaptation of arid and semi arid crops to future climates

Emerging constraints associated with climate change are posing an increasing threat to crop yields. In the arid and semiarid regions of Africa, crop failure, due to extreme events such as drought, is predicted to cause major food security issues. Root traits can improve crop resilience to drought and poor soil conditions by increasing the crop's ability to acquire water and soil nutrients. However, selection based on root traits in agronomically meaningful contexts poses practical challenges. In fact, phenotyping represents a major bottleneck for root traits breeding, with trade-offs between precision and throughput. In this chapter, we will describe advances in low- and high-throughput root observation and sampling methods that can be easily deployed to measure root traits in field conditions. We will further describe a high-throughput root phenotyping pipeline that has recently been implemented to phenotype root architectural and anatomical traits in pearl millet grown in West African Sahelian conditions. These new methods can facilitate the selection of next generation crops with improved root systems that are more adapted to future climates