Modification of colorimetric method based digital soil test kit for determination of macronutrients in oil palm plantation

It is the need of time that oil palm farmers must perform the spatially planned soil analysis to know about the fertilizer sufficient and deficient zones of land.Colorimetric method is a suitable and fast solution of soil analysis for NPK determination using the digital soil test kit.NPK determination procedure with a digital soil test kit was undefined for oil palm.Furthermore,the digital soil test kit determines the passage of light through an opaque medium of soil solution with a specified reagent.Therefore,environmental light may interfere leading to wrong results of NPK measurement.Likewise,this equipment was non-incorporable with the controller of any VRT fertilizer applicator.In this research,these issues were addressed and the NPK measurement procedure was defined for oil palm plantation by modifying the‘soil to water’ratio in sample soil solution with an optimum environmental light range of 18-23 W/m^(2).‘Soil to water’ratios were found for nitrogen,phosphorus and potassium as 0.31 to 5.00,1.00 to 5.00 and 4.50 to 5.00,respectively to fit the requirement of NPK for oil palm in the prescribed range of the equipment.Validation study of modified digital soil test kit showed that 91.7%N,89.6%P and 93.8%K results of modified digital soil test kit were matched with analytical laboratory method.Thus,the reliability of NPK results using digital soil test kit was enhanced,making the kit incorporable with the controller of variable rate fertilizer applicator through remote monitoring based data acquisition system.The outcome of this research can be used in the development of an IoT network data fusion for dynamic assessment of the NPK variation in the soil and nutrient management in oil palm plantations.

A Turn-On Fluorescence Chemosensor for Cyanide in Aqueous Media Based on a Nucleophilic Addition Reaction

We synthesized a new cyanide （CN-） chemosensor CX based on a nucleophilic addition reaction prompted by cyanide ion, which could be used for highly selective and sensitive fluorescence turn-on detection of cyanide in aqueous media. The CX showed selective fluorescence recognition for CN-, the miscellaneous competitive anions （F-, Cl-, Br-, I-, AcO-, H2PO4, HSO4, ClO4, S2-, PO4^3-, CO3^2- and SCN- ） did not lead to any significant interference. The detection limit of the sensor towards CN is 1.15 × 10^-7 mol.L- 1. The sensor has been successfully applied to estimate the cyanide ion in seeds of cherries. Test strips based on CX were fabricated, which could be used as a convenient and efficient CN test kit to detect CN in aqueous solution for ＂in-the-field＂ measurement.

Addition of surfactants to Low Salinity Waterflooding in microfluidics system to increase oil recovery

This study was conducted to investigate the phenomenon of oil removal from inside pores using a self-designed microfluidic test kit.An artificial micromodel chip as a representation of porous rocks has been created with a uniform pore structure design and made of PMMA(Polymethyl Methacrylate)material.The micromodel chip has a porosity of 27.8%as well as a permeability of 2.7 Darcy.By using the microfluidic test kit,this study has investigated how low salinity water(LSW)injection with MgCl_(2)divalent ions and the addition of anionic surfactant,linear alkylbenzene sulfonate mixed with nonionic surfactants,nonylphenol ethoxylate(NP-10)affects to oil recovery.The injection of LSW and surfactant solution was carried out with different injection stages,injection rates and surfactant solutions con-centrations.Visual images during the injection process are recorded for analysis,which is the advantage of dynamic testing using this microfluidic test kit over conventional coreflooding.From this study,it is indicated that the selection of ions contained in LSW affects the success of LSW injection.Reducing the surfactant injection rate from 50 mL/min to 20 mL/min can increase the oil recovery from 1.27%to 4.29%.Oil recovery was also higher on surfactant injection which resulted in lower interfacial tension of the system based on the calculation of interfacial tension obtained from the Chun-Huh and Ghosh equations from the Winsor test.From all injection scenarios carried out in this study,the highest increase in oil recovery of 26.87%OOIP was obtained by injecting surfactant solutions directly in the secondary stage without prior LSW injection.