Hydrothermal Growth of Zinc Oxide (ZnO) Nanorods (NRs) on Screen Printed IDEs for pH Measurement Application

There is considerable interest in nanostructured materials with interdigitated electrodes (IDEs) platforms to detect and monitor the level of various ions in numerous applications. Herein, we report the design and fabrication of IDEs based pH sensor by using hydrothermal growth of ZnO nanorods (NRs). A four-step deposition of ZnO seed layer followed by a hydrothermal treatment lead to the heavily ordered ZnO NRs patterns on the screen printed IDEs. The structural, chemical compositional and electrical properties of the NRs were investigated and examined by using field emission scanning electron microscopy (FeSEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) technique and Keithley 4200 semiconductor characterization system respectively. The sensor capacitance and pH were found to be inversely proportional at a working frequency of 1 kHz. The sensor displayed sensitivity of 1.06 nF/pH in the range of pH 4−10

Image encryption based on permutation-substitution using chaotic map and Latin Square Image Cipher

In this paper we presented a image encryption based on permutation-substitution using chaotic map and Latin square image cipher. The proposed method consists of permutation and substitution process. In permutation process, plain image is permuted according to chaotic sequence generated using chaotic map. In substitution process, based on secrete key of 256 bit generate a Latin Square Image Cipher (LSIC) and this LSIC is used as key image and perform XOR operation between permuted image and key image. The proposed method can applied to any plain image with unequal width and height as well and also resist statistical attack, differential attack. Experiments carried out for different images of different sizes. The proposed method possesses large key space to resist brute force attack

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Not AvailableThe effect of cow-urine and bio-fertilizers based fertigation schedule was studied at varying levels of drip irrigation on various cucumber parameters in a naturally ventilated polyhouse during summer season. The experiment was conducted in a randomized block design with 11 treatments and 3 replication comprising of two drip irrigation levels viz., I2(IW/CPE= 0.4) and I4 (IW/CPE = 0.8), five fertigation levels and one farmers’ practice. The total soluble solids (TSS) were numerically higher in irrigation level I2 than in I4. The yield was statistically higher in different treatments compared to farmers’ practice (4.47 kg m-2). The gross return and B: C ratio were highest in treatment F2I4 (where F2 is 100 % of recommended NPK doses (1/3rd N and full P, K applied as basal and 2/3rdN through fertigation + Azotobacter + PSB) and 5% cow-urine) and were lowest under farmers’ practice. However, the irrigation levels didn’t influence the marketable yield. The overall results indicated that combined application of bio-fertilizers and fertilizers has positive effect on yield, growth and quality parameter due to addition of nutrients and saving of at least 50 % of water and hence can be exploited as a sustainable approach under integrated nutrient management.Not Availabl

Disposable pH sensor on paper using screen-printed graphene-carbon ink modified zinc oxide nanoparticles

Estimation of pH is vital to assess the biochemical and biological processes in a wide variety of applications ranging from water to soil, health, and environment monitoring. This work reports a screen-printed flexible and disposable pH sensor using the impedimetric method. The pH sensor was fabricated by screen printing Graphene-Carbon modified Zinc Oxide based active layer on a paper substrate and shows nearly three orders of change in impedance magnitude in the pH range of 2 – 9. The sensor was carefully designed using COMSOL® Multiphysics software to understand the influence of electrode geometry and the electrical potential developed across the structure. The developed sensor was used for pH monitoring of soil and exhibited high sensitivity of 5.27 kΩ /pH (2-8) with a correlation coefficient (R 2 ) of 0.99. Finally, an IoT-enabled smart pH detection system was implemented for continuous pH monitoring for potential application in digital agriculture. The outcome demonstrates that the presented flexible and disposable pH sensor could open new opportunities for monitoring of water, product process, human health, and chemical (or bio) reactions even using small volumes of samples

Impact of Analyte pH on the Sensitivity of Screen-Printed Flexible Ammonium Sensor

This work reports the impact of analyte pH conditions on the sensitivity of the Ammonium (NH4+) sensor. The NH4+ sensor was developed by screen printing an IDE structure and subsequently modified with multiwalled carbon nanotube (MWCNT) and Zinc Oxide (ZnO) nanocomposite active layer on a fiber epoxy substrate. The sensor impedance response was studied for the varying NH4+ analyte pH levels, and device sensitivity was found to decrease with increased analyte pH concentrations (pH 4 - pH 9). The maximum impedance of the sensor operated at pH 4 was ~ 10.5% higher when performed at pH 9. The outcome demonstrates that the presented study could open new opportunities to develop highly sensitive nutrient sensors based on tuning of the analyte pH conditions. Alternately the study highlights the need for maintaining analyte pH conditions for the stable and reliable response of the flexible ammonium sensor