Journal Staff

Keeping the fact in mind that different morphologies have strong influence on piezoelectric properties, ZnO NNs were synthesized on textile for harvesting piezoelectricity. Piezoelectric potential was captured from ZnO NNs grown on textile by using AFM in contact mode. Structural study was carried out by using FESEM, HRTEM and XRD techniques. The recorded output potential and current was more than 45 mV and 150 nA. The combination of ZnO NNs and textile can be used effectively for energy harvesting applications and the use of textile fabric can pave the way for cheap, flexible, wearable, washable and environment friendly nanodevices

THE COMPARATIVE DEPOSITIONAL HETEROGENEITY OF MANCHHAR FORMATION (SIWALIK GROUP), SOUTHERN INDUS BASIN, PAKISTAN

Present study is carried out for detailed description, distribution and interpretation of lithofacies and textural analysis of Manchhar Formation from Gaj River, Manchhar Lake and Lal Bagh Sections of Southern Indus Basin Pakistan. Four different clastic lithofacies are identified during present study, which are conglomeratic sandstone (Gt), shale (Fm), fine to coarse grain flat bedded sandstone (Sh) and fine to coarse grain trough cross-bedded sandstone (St). These Facies suggest that Manchhar Formation is deposited in the Beach to shallow agitated water and fluvial system. Twenty-nine (29) unconsolidated loose and friable sandstone samples were selected for textural analysis. Grain-size parameters such as mean, median, standard deviation, Skewness and Kurtosis were used for transport history, mode and hydrodynamic energy condition to recognize the depositional environment. Stewart Diagram shows deltaic/wave water process takes active role under the influence of wave process. Linear discriminant functions analysis show that the fluvial environment of deposition dominates and influences shallows water and beach environment. Passega diagram reveals that transport mode was rolling and suspension by the tractive current that shows the fluvio-deltaic to deltaic wave with the influence of wave depositional environment of Miocene-Pliocene (Neogene) Manchhar Formation

Synthesis, Characterization and Applications of Metal Oxide Nanostructures

The main objective of nanotechnology is to build self-powered nanosystems that are ultrasmall in size, exhibit super sensitivity, extraordinary multi functionality, and extremely low power consumption. As we all know that 21st century has brought two most important challenges for us. One is energy shortage and the other is global warming. Now to overcome these challenges, it is highly desirable to develop nanotechnology that harvests energy from the environment to fabricate self-power and low-carbon nanodevices. Therefore a self-power nanosystem that harvests its operating energy from the environment is an attractive proposition. This is also feasible for nanodevices owing to their extremely low power consumption. One advantageous approach towards harvesting energy from the environment is the utilization of semiconducting piezoelectric materials, which facilitate the conversion of mechanical energy into electrical energy. Among many piezoelectric materials ZnO has the rare attribute of possessing both piezoelectric and semiconducting properties. But most applications of ZnO utilize either the semiconducting or piezoelectric property, and now it’s time to fully employ the coupled semiconducting-piezoelectric properties to form  the basis for electromechanically coupled nanodevices. Since wurtzite zinc oxide (ZnO) is structurally noncentral symmetric and has the highest piezoelectric tensor among tetrahedrally bonded semiconductors, therefore it becomes a promising candidate for energy harvesting applications. ZnO is relatively biosafe and biocompatible as well, so it can be used at large scale without any harm to the living environment. The synthesis of another transition metal oxide known as Co3O4 is also important due to its potential usage in the material science, physics and chemistry fields. Co3O4 has been studied extensively due to low cost, low toxicity, the most naturally abundant, high surface area, good redox, easily tunable surface and structural properties. These significant properties enable Co3O4 fruitful for developing variety of nanodevices. Co3O4 nanostructures have been focused considerably in the past decade due to their high electro-chemical performance, which is essential for developing highly sensitive sensor devices. I started my work with the synthesis of ZnO nanostructures with a focus to improve the amount of harvested energy by utilizing oxygen plasma treatment. Then I grow ZnO nanorods on different flexible substrates, in order to observe the effect of substrate on the amount of harvested energy. After that I worked on understanding the mechanism and causes of variation in the resulting output potential generated from ZnO nanorods. My next target belongs to an innovative approach in which AFM tip decorated with ZnO nanorods was utilized to improve the output energy. Then I investigated Co3O4 nanostructures though the effect of anions and utilized one of the nanostructure to develop a fast and reliable pH sensor. Finally to take the advantage of higher degree of redox chemistry of NiCo0O4 compared to the single phase of nickel oxide and cobalt oxide, a sensitive glucose sensor is developed by immobilizing glucose oxidase. However, there were problems with the mechanical robustness, lifetime, output stability and environmental adaptability of such devices, therefore more work is going on to find out new ways and means in order to improve the performance of fabricated nanogenerators and sensors

Synthesis, Characterization and Applications of Metal Oxide Nanostructures

The main objective of nanotechnology is to build self-powered nanosystems that are ultrasmall in size, exhibit super sensitivity, extraordinary multi functionality, and extremely low power consumption. As we all know that 21st century has brought two most important challenges for us. One is energy shortage and the other is global warming. Now to overcome these challenges, it is highly desirable to develop nanotechnology that harvests energy from the environment to fabricate self-power and low-carbon nanodevices. Therefore a self-power nanosystem that harvests its operating energy from the environment is an attractive proposition. This is also feasible for nanodevices owing to their extremely low power consumption. One advantageous approach towards harvesting energy from the environment is the utilization of semiconducting piezoelectric materials, which facilitate the conversion of mechanical energy into electrical energy. Among many piezoelectric materials ZnO has the rare attribute of possessing both piezoelectric and semiconducting properties. But most applications of ZnO utilize either the semiconducting or piezoelectric property, and now it’s time to fully employ the coupled semiconducting-piezoelectric properties to form  the basis for electromechanically coupled nanodevices. Since wurtzite zinc oxide (ZnO) is structurally noncentral symmetric and has the highest piezoelectric tensor among tetrahedrally bonded semiconductors, therefore it becomes a promising candidate for energy harvesting applications. ZnO is relatively biosafe and biocompatible as well, so it can be used at large scale without any harm to the living environment. The synthesis of another transition metal oxide known as Co3O4 is also important due to its potential usage in the material science, physics and chemistry fields. Co3O4 has been studied extensively due to low cost, low toxicity, the most naturally abundant, high surface area, good redox, easily tunable surface and structural properties. These significant properties enable Co3O4 fruitful for developing variety of nanodevices. Co3O4 nanostructures have been focused considerably in the past decade due to their high electro-chemical performance, which is essential for developing highly sensitive sensor devices. I started my work with the synthesis of ZnO nanostructures with a focus to improve the amount of harvested energy by utilizing oxygen plasma treatment. Then I grow ZnO nanorods on different flexible substrates, in order to observe the effect of substrate on the amount of harvested energy. After that I worked on understanding the mechanism and causes of variation in the resulting output potential generated from ZnO nanorods. My next target belongs to an innovative approach in which AFM tip decorated with ZnO nanorods was utilized to improve the output energy. Then I investigated Co3O4 nanostructures though the effect of anions and utilized one of the nanostructure to develop a fast and reliable pH sensor. Finally to take the advantage of higher degree of redox chemistry of NiCo0O4 compared to the single phase of nickel oxide and cobalt oxide, a sensitive glucose sensor is developed by immobilizing glucose oxidase. However, there were problems with the mechanical robustness, lifetime, output stability and environmental adaptability of such devices, therefore more work is going on to find out new ways and means in order to improve the performance of fabricated nanogenerators and sensors

Effect of Post Growth Annealing on the Structural and Electrical Properties of ZnO/CuO Composite Nanostructures

In the present work, ZnO/CuO composite nanostructures have been grown on fluorine doped tin oxide coated glass substrate by aqueous chemical growth method. To observe the effect of post growth annealing (500°C, 1 min) on the structural properties of ZnO nanorods scanning electron microscope and X-ray diffraction techniques have been utilized. SEM images of post growth annealed (post growth annealed) sample reveal that the average diameter of ZnO NRs has considerably increased in comparison with as grown sample. Moreover after post growth annealing the ZnO NRs showed more clearly hexagonal wurtzite structure. Beside this the NRs are also uniform and well aligned with a high aspect ratio of $~10$. In XRD pattern the strongly intense (002) peak of the post growth annealing sample suggest that the crystal quality of the NRs have also been improved significantly. Since the structural improvement have a significant impact on charge transport properties as well, therefore the effect of post growth annealed has also been investigated by the electrical characterization of ZnO/CuO based heterojunction. The current-voltage measurements of the post growth annealed sample showed improvement in the current in comparison with as grown sample. The impedance study has also confirmed that the post growth annealed has influence on the electrical properties. The presented post growth annealed heterojunction of ZnO/CuO may have space in applications like sensors and oxide based diodes in the devices fabrication

Fabrication of zinc oxide nanoneedles on conductive textile for harvesting piezoelectric potential

Keeping the fact in mind that different morphologies have strong influence on piezoelectric properties, ZnO NNs were synthesized on textile for harvesting piezoelectricity. Piezoelectric potential was captured from ZnO NNs grown on textile by using AFM in contact mode. Structural study was carried out by using FESEM, HRTEM and XRD techniques. The recorded output potential and current was more than 45 mV and 150 nA. The combination of ZnO NNs and textile can be used effectively for energy harvesting applications and the use of textile fabric can pave the way for cheap, flexible, wearable, washable and environment friendly nanodevices

Effect of anions on the morphology of Co3O4 nanostructures grown by hydrothermal method and their pH sensing application

A fast, reliable, accurate, precise and sensitive pH sensor device is highly demanding for the monitoring of pH in biological, clinical and food industry samples. In this research work, the effect of anions on the morphology of cobalt oxide (Co3O4) nanostructures is investigated using low temperature chemical approach for the growth. Different anions have shown visible effect on the morphology of Co3O4 nanostructures. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy techniques were used for the material characterization. This study has shown highly dense, uniform and good crystal quality of fabricated Co3O4 nanostructures. The nanostructures obtained from the cobalt chloride were used for the development of potentiometric pH sensor electrode. The pH sensor electrode showed excellent linearity and close to Nernstian response for the pH range of 3-13 with a sensitivity of -58.45 mV/pH. Moreover, the proposed sensor showed a fast response time of 53 s, and acceptable reducibility and repeatability. The highly sensitive and a fast time response of the proposed sensor device indicate its potential application for the monitoring of pH from real samples including biological fluids

The fabrication of white light-emitting diodes using the n-ZnO/NiO/p-GaN heterojunction with enhanced luminescence

Cheap and efficient white light-emitting diodes (LEDs) are of great interest due to the energy crisis all over the world. Herein, we have developed heterojunction LEDs based on the well-aligned ZnO nanorods and nanotubes on the p-type GaN with the insertion of the NiO buffer layer that showed enhancement in the light emission. Scanning electron microscopy have well demonstrated the arrays of the ZnO nanorods and the proper etching into the nanotubes. X-ray diffraction study describes the wurtzite crystal structure array of ZnO nanorods with the involvement of GaN at the (002) peak. The cathodoluminescence spectra represent strong and broad visible emission peaks compared to the UV emission and a weak peak at 425 nm which is originated from GaN. Electroluminescence study has shown highly improved luminescence response for the LEDs fabricated with NiO buffer layer compared to that without NiO layer. Introducing a sandwich-thin layer of NiO between the n-type ZnO and the p-type GaN will possibly block the injection of electrons from the ZnO to the GaN. Moreover, the presence of NiO buffer layer might create the confinement effect

Why We Hate Politics

Winner of the 2008 W J M Mackenzie Book Prize Politics was once a term with an array of broadly positive connotations, associated with public scrutiny, deliberation and accountability. Yet today it is an increasingly dirty word, typically synonymous with duplicity, corruption, inefficiency and undue interference in matters both public and private. How has this come to pass? Why do we hate politics and politicians so much? How pervasive is the contemporary condition of political disaffection? And what is politics anyway? In this lively and original work, Colin Hay provides a series of innovative and provocative answers to these questions. He begins by tracing the origins and development of the current climate of political disenchantment across a broad range of established democracies. Far from revealing a rising tide of apathy, however, he shows that a significant proportion of those who have withdrawn from formal politics are engaged in other modes of political activity. He goes on to develop and defend a broad and inclusive conception of politics and the political that is far less formal, less state–centric and less narrowly governmental than in most conventional accounts. By demonstrating how our expectations of politics and the political realities we witness are shaped decisively by the assumptions about human nature that we project onto political actors, Hay provides a powerful and highly distinctive account of contemporary political disenchantment. Why We Hate Politics will be essential reading for all those troubled by the contemporary political condition of the established democracies