Water Demand and Salinity

The fresh water constitute only 3% of the total water on earth out of which underground water constitute 29 and <1% is in the form of lakes and rivers on the earth surface. Considering the rapidly increasing human population and demand for diverse food items crop production must increase substantially. At the same time arable land and good quality irrigation water resources are being depleted at faster rate particularly in the arid, semi-arid and tropical regions. Over the years the salinization of soil and water has steadily increased due to various causes and the increase in food production has essentially depends on this degrading resources. Since the balance between water demand and water availability has reached critical level in many regions of the world a sustainable approach to water resources and salinity management has become imperative. This chapter highlights global water resources, its demand and supply, salinity and its causes, effect of climate change and its management for sustainable use

Nano–bio interaction between human immunoglobulin G and nontoxic, near-infrared emitting water-borne silicon quantum dot micelles

In recent years, the field of nanomaterials has exponentially expanded with versatile biological applications. However, one of the roadblocks to their clinical translation is the critical knowledge gap about how the nanomaterials interact with the biological microenvironment (nano–bio interactions). When nanomaterials are used as drug carriers or contrast agents for biological imaging, the nano–bio interaction-mediated protein conformational changes and misfolding could lead to disease-related molecular alterations and/or cell death. Here, we studied the conformation changes of human immunoglobulin G (IgG) upon interaction with silicon quantum dots functionalized with 1-decene, Pluronic-F127 (SiQD-De/F127 micelles) using UV-visible, fluorescence steady state and excited state kinetics, circular dichroism, and molecular modeling. Decene monolayer terminated SiQDs are accumulated inside the Pluronic F127 shells to form SiQD-De/F127 micelles and were shown to bind strongly with IgG. In addition, biological evaluation studies in cell lines (HeLa, Fibroblast) and medaka fish (eggs and larvae) showed enhanced uptake and minimal cytotoxicity. Our results substantiate that engineered QDs obviating the protein conformational changes could have adept bioefficacy

Semiconductor-Metal Nano-Floret Hybrid Structures by Self-Processing Synthesis

We present a synthetic strategy that takes advantage of the inherent asymmetry exhibited by semiconductor nanowires prepared by Au-catalyzed chemical vapor deposition (CVD). The metal–semiconductor junction is used for activating etch, deposition, and modification steps localized to the tip area using a wet-chemistry approach. The hybrid nanostructures obtained for the coinage metals Cu, Ag, and Au resemble the morphology of grass flowers, termed here Nanofloret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell cap. The synthetic method is used to prepare hybrid nanostructures in one step by triggering a programmable cascade of events that is autonomously executed, termed self-processing synthesis. The synthesis progression was monitored by ex situ transmission electron microscopy (TEM), in situ scanning transmission electron microscopy (STEM) and inductively coupled plasma mass spectrometry (ICP-MS) analyses to study the mechanistic reaction details of the various processes taking place during the synthesis. Our results indicate that the synthesis involves distinct processing steps including localized oxide etch, metal deposition, and process termination. Control over the deposition and etching processes is demonstrated by several parameters: (i) etchant concentration (water), (ii) SiGe alloy composition, (iii) reducing agent, (iv) metal redox potential, and (v) addition of surfactants for controlling the deposited metal grain size. The NF structures exhibit broad plasmonic absorption that is utilized for demonstrating surface-enhanced Raman scattering (SERS) of thiophenol monolayer. The new type of nanostructures feature a metallic nanoshell directly coupled to the crystalline semiconductor NW showing broad plasmonic absorption

Polymer membrane stabilized gold nanostructures modified electrode and its application in nitric oxide detection

Nafion polymer/gold nanostructures film that can be utilized as a proficient electrochemical sensor for nitric oxide was prepared by an electrochemical process, forming the gold nanostructures (Au<SUB>nano</SUB>) through infiltration into a Nafion (Nf) matrix preassembled on an electrode. The formation of gold nanostructures was monitored by the in situ spectroelectrochemical method. The in situ absorption spectra of Au<SUB>nano</SUB> showed systematic and uniform formation of gold nanostructures at the Nafion (Nf-Au<SUB>nano</SUB>)-modified electrode. The electrochemically formed Nf-Au<SUB>nano</SUB> was characterized by UV-visible spectroscopy, X-ray diffraction, scanning electron microscope, transmission electron microscope, and electrochemical techniques. The surface plasmon absorption spectra recorded for the wet and dry Nf-Au<SUB>nano</SUB> composite film showed the interaction between the gold nanostructures and the swelled polymer matrix. The longitudinal surface plasmon band and the TEM images observed for the Nf-Au<SUB>nano</SUB> showed the formation of nanorod-like and Y-shaped gold nanostructures in the Nafion matrix. In addition to the nanoparticles, the edge-to-edge interactions lead to the formation of 1D assembly. The electrical communication between the gold nanostructures embedded in the Nafion film improved the electrocatalytic properties of the modified electrode toward NO detection. The Nf-Au<SUB>nano</SUB> electrode showed excellent sensitivity for NO detection with the experimental detection limit of 1 nM. The present Nf-Au<SUB>nano</SUB> electrode is very simple to fabricate and is stable, sensitive, and reproducible

Electrochemical and in situ spectroelectrochemical studies on the gold nanoparticles co-deposited with cobalt hexacyanoferrate modified electrode and its application in sensor

Gold nanoparticles (Aunano) co-deposited with cobalt hexacyanoferrate (CoHCF) modified electrode was prepared by electrodeposition on glassy carbon electrode (represented as GC/Aunano~CoHCF) and characterized. The surface morphology of the modified electrode was studied by AFM and the electrochemical properties were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The co-deposition of Aunano with CoHCF improved the electrochemical behavior of the Aunano~CoHCF modified electrode when compared to CoHCF modified electrode. The in-situ spectroelectrochemical changes of Aunano~CoHCF modified electrode was studied to understand the redox switching of CoHCF in the presence of Aunano. The in-situ spectral study showed that the codeposited Aunano with CoHCF acted as nanoelectrode and improved the electron transfer and redox switching processes when compared to CoHCF modified electrode. An enhanced electrocatalytic oxidation of hydrogen peroxide (H2O2) was observed at the GC/Aunano~CoHCF electrode with an onset potential of 0.5 V when compared to GC/CoHCF electrode. The poly Au electrode did not show a similar oxidation peak for H2O2 oxidation. The Aunano co-deposited with CoHCF (GC/Aunano~CoHCF) significantly enhanced the electrocatalytic property of CoHCF. The amperometric detection of H2O2 was studied at the CoHCF modified electrode in the presence and absence of Aunano and poly Au electrode. The GC/Aunano~CoHCF electrode showed fast sensing response and lower detection limit for H2O2 when compared to GC/CoHCF and poly Au electrode. The electrochemical, in situ spectroelectrochemical and electrocatalytic properties of Aunano co-deposited with CoHCF clearly showed that the GC/Aunano~CoHCF electrode could be used as an electrochemical sensor

Electroless synthesis of multibranched gold nanostructures encapsulated by poly(o-phenylenediamine) in Nafion

Multibranched gold (Au) nanocomposite materials encapsulated by poly(o-phenylenediamine) (PoPD) (Au@PoPD) were synthesized in a Nafion polymer film through the electroless synthetic route. The micro-heterogeneous structured Nafion film acted as a reaction vessel and as the template for the formation of Au@PoPD nanocomposite materials leading to the formation of highly uniform distribution of high density of the polymer-gold nanocomposite material. The formation of Au@PoPD nanomaterials at the GP/Nf surface was scrutinized by recording in situ absorption spectra and was characterized. The formation of the (1 1 1) plane of gold was dominant at the Au@PoPD nanocomposite. The ratio of the benzenoid and quinoid units of the PoPD (ca. 1.65) observed for the Au@PoPD confirmed that the micro-heterogeneous structure of Nf film acted as a reaction vessel and as template for the formation of Au@PoPD nanocomposite material. Both PoPD and Au at the Au@PoPD nanocomposite showed electrochemical activities at the GC/Nf-Au@PoPD modified electrode. The electrocatalytic activity of the GC/Nf-Au@PoPD modified electrode was studied for oxygen reduction reaction (ORR)

Not Available

Not AvailableThe fresh water constitute only 3% of the total water on earth out of which underground water constitute 29 and <1% is in the form of lakes and rivers on the earth surface. Considering the rapidly increasing human population and demand for diverse food items crop production must increase substantially. At the same time arable land and good quality irrigation water resources are being depleted at faster rate particularly in the arid, semi-arid and tropical regions. Over the years the salinization of soil and water has steadily increased due to various causes and the increase in food production has essentially depends on this degrading resources. Since the balance between water demand and water availability has reached critical level in many regions of the world a sustainable approach to water resources and salinity management has become imperative. This chapter highlights global water resources, its demand and supply, salinity and its causes, effect of climate change and its management for sustainable use.Not Availabl

Not Available

Not AvailableThe fresh water constitute only 3% of the total water on earth out of which underground water constitute 29 and <1% is in the form of lakes and rivers on the earth surface. Considering the rapidly increasing human population and demand for diverse food items crop production must increase substantially. At the same time arable land and good quality irrigation water resources are being depleted at faster rate particularly in the arid, semi-arid and tropical regions. Over the years the salinization of soil and water has steadily increased due to various causes and the increase in food production has essentially depends on this degrading resources. Since the balance between water demand and water availability has reached critical level in many regions of the world a sustainable approach to water resources and salinity management has become imperative. This chapter highlights global water resources, its demand and supply, salinity and its causes, effect of climate change and its management for sustainable use.Not Availabl

Mitigation of Abiotic and Biotic Stress Using Plant Growth Regulators in Rice

Split plot design experiments were conducted to assess the performance of growth regulating compounds for mitigating moisture stress and the incidence of Brown Plant Hopper (BPH) in rice. The main plot treatments (4) comprised moisture stress free control (M1), moisture stress during panicle initiation stage alone (M2), moisture stress during flowering stage alone (M3), and moisture stress during both panicle initiation and flowering stages (M4). The sub-plot treatments (5) were foliar application of growth regulating compounds including chlormequat chloride at 200 ppm (S1), mepiquat chloride at 200 ppm (S2), brassinolide at 0.1 ppm (S3), pink pigmented facultative methylotrophs (PPFM) at 1% (S4), and no spray control (S5). The reduced plant growth attributes were registered under moisture stress at both panicle initiation and flowering stages. The spraying of 1% PPFM during the flowering or both at panicle initiation and flowering stages led to better performance than the other treatments. Also, spraying 1% PPFM brought down the population of BPH to a considerable level during both years of experiments. This suggests that spraying 1% PPFM in the post-flowering stage helps to mitigate the ill effect the moisture stress and BPH incidence