Study variate, auxiliary variate, mean squared error, efficiency,

We consider a class of ratio-product estimators for estimating a finite population mean. The asymptotically optimum estimator in the class is identified, along with its approximate mean-square error.This estimator requires prior knowledge of the parameter C D ρC y =C x , where ρ is the correlation coefficient between the study variate y and the auxiliary variate x, and C y and C x are coefficients of variation of y and x respectively. If C is unknown in advance, then it can be replaced by its consistent estimateĈ, with the resulting estimator known as an 'estimator based on the estimating optimum'. It is shown that, to the first order of approximation, both estimators have the same mean-square error, and that they are generally more efficient than the usual ratio and product estimators.

Continuous light can be used as a tool to understand the diurnal rhythm of plants and it can also be used to increase the plant production. In the present research, we aimed to investigate the photosynthetic performance of V. radiata under continuous light as compared with the plants grown under normal light duration. Chlorophyll a fluorescence transient (OJIP test) technique was used to understand the effect on various stages of photosynthesis and their consequences under continuous light condition. Various Chl a Fluorescence kinetic parameters such as Specific energy fluxes (per Q A -reducing PSII reaction center (RC)) (ABS /RC; TR 0 /RC; ET 0 /RC; DI 0 /RC), phenomenological fluxes, leaf model, (ABS/CSm; TR/CSm; ETo/CSm), Quantum yields and efficiencies (φPo; φEo; Ψo) and Performance index (PI abs ) was extracted and analysed in our investigation. Conclusively, our study has revealed that continuous light alters the photosynthetic performance of V. radiata at a different point but also improve plant productivity.

This paper presents exponential ratio and product estimators for estimating finite population mean using auxiliary information in double sampling and analyzes their properties. These estimators are compared for their precision with simple mean per unit, usual double sampling ratio and product estimators. An empirical study is also carried out to judge the merits of the suggested estimators.

In the present work, we demonstrated the biosynthesis of silver nanoparticles (AgNPs) by highly stable, economic and eco-friendly method using leaf extract of Terminalia arjuna (T. arjuna) and employing as a catalyst for the degradation of methyl orange (MO), methylene blue (MB), congo red (CR) and 4- nitrophenol (4-NP). The biosynthesis of AgNPs was visually validated through the appearance of reddish-brown color and further confirmed by the UV-spectra at 418 nm. The TEM and FE-SEM studies revealed the spherical shape of particles with size ranged between 10–50 nm. Face centered cubic crystalline nature of AgNPs was proved by XRD analysis. The negative value of zeta potential (−21.7) indicated the stability of AgNPs and elemental composition was confirmed by EDS. FT-IR analysis revealed the functional groups present in the plant extract trigger the biosynthesis of AgNPs. The AgNPs exhibited strong degradation of MO (86.68%), MB (93.60%), CR (92.20%) and 4NP (88.80%) by completing the reduction reaction within 20 min. The reaction kinetics followed the pseudo-first-order and displayed k-values (rate constant) 0.166 min−1, 0.138 min−1, 0.182 min−1 and 0.142 min−1 for MO, MB, CR and 4-NP respectively. This study showed an efficient, feasible and reproducible method for the biosynthesis of eco-friendly, cheap and long-time stable AgNPs and their application as potent catalysts against the degradation of hazardous dyes.