Nanotechnology: Giga game for soils

Research on colloidal properties of soils, especially of its clay and decayed organic matter components are pillars of edifice of soil science. The colloids control almost all soil reactions, but their behavior is controlled by dilution, change in pH, ion exchange, accretion of bases and many other processes, some of which are natural, while many others are anthropogenic. The anthropogenic manipulation of soils is the foundation of agrarian civilization, but spread into managed-forest, and urban ecosystems with time. In the twentieth century, great breakthroughs have been achieved in order to make soils more productive and responsive to environmental challenges. Historically, soil science as a discipline showed enormous capacity to absorb scientific advancement made in kindred disciplines into its body of knowledge. The X-ray diffraction and electron microscopic studies on clay particles in the last century exhibited nanoscale nature of the particles in all three dimensions. Therefore, it was but natural that clay and organic matter components of soils would be of primary concern to nanotechnology regardless of the field of activity – from physics to medicine. The added advantages of clay were their role in genesis of life on earth, and in evolutionary diversification of Neoproterozoic life forms. It was no wonder that many authors believe that nanoscience and nanotechnology sprouted from clay mineralogy and crystallography. Richard Feynman in his lecture, “There's plenty of room at the bottom: An invitation to enter a new field of physics” in 1959 envisioned that solid state materials, of which clay is a part, would be of great interest to nanotechnology.
 
Nanofabrication involving clay is a distinct field, because it departs from the conventional field of nanotechnology (e.g., nanoelectronics, nanomaterials), and is far more challenging than conventional application fields (e.g., cell phone, computer, sensors, cloths, and other industrial products). This is because: (a) clay is an interface of the physical world and the world of life, and (b) soil is the central domain of geosphere, biosphere, atmosphere, and hydrosphere, and therefore, soil scientists have the responsibility to support life and protect the environment. For nanofabrication involving clays, methods followed in industry (like melting materials at a high temperature to segregate atoms / ions at plasma state) cannot be copied. It is no hindrance, because the system obeys the laws of ion exchange, adsorption-desorption, aggregation-dispersion, solubility-dissolution to name a few. The most vital yardstick is that the system has to be capable of releasing nutrient ions in plant-available forms. One of the key modules of nanofabrication is manipulation of bonds, which is a common phenomenon in soils. Clays have both covalent and ionic bonds; a feature unique for developing a passive control system for a nutrient supply mechanism. There are enormous numbers of examples in soils, where bonds are changed from one form to another through isomorphous substitution or insertion of small ions, or by the use of organic compounds (for masking of van der Waal’s force). Nanotechnology in the clay system does not promise a control system that we experience in electrical machines, or in satellites, or in chemical reactors. But, it has to be a knowledge-based passive system, and for sure, it is going to create millions of rhizospheres in an acre of land to support the growth of millions of plants for a crop; a breakthrough to place agriculture into the new millennium. 
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Nanotechnology in Agriculture: Propagating, Perpetuating, and Protecting Life

Natural agricultural production is an open system, both energy and matters are exchanged freely in this system involving interactions of geosphere (especially pedosphere), biosphere, and atmosphere. Agriculture provides crops for food and industry, fiber, fuel, auto-fuel and drugs. On one hand it faces ever escalating food prices and farmer’s suicides, and on the other hand input use efficiency is low. Present agricultural practices have made harvests toxic, mother’s milk a poison, and breathing-air venom. In this background, nanotechnology brings new hope. Nanotechnology is an interdisciplinary venture-field that converge science, engineering, and agriculture and food systems into one. The Environmental Protection Agency of the US has defined nanotechnology as the understanding and control of matter at dimensions of roughly 1-100 nm, where unique physical properties make novel applications possible. The triple problems of agriculture – over-dependence on supplementary irrigation, vulnerability to climate, and poor input and energy conversion to products – can be solved by using nanotechnology, provided agricultural scientists seek a chance to try and cooperate with scientists of kindred disciplines. Nanotechnology is new to agriculture; a ventured field of less than a decade old. But, already success has been achieved for manufacturing nano-pesticides and nano-fertilizer, in disease elimination in poultry, in food packaging, use of agricultural waste, nanosensors, precision agricultural practices, and in livestock and fisheries. Nanotechnology holds the potential to revolutionize agriculture and food systems in the areas of nano-fertilizers, pesticide career, microfluidics, BioMEMS, nucleic acid bioengineering, smart treatment delivery systems, nanobioprocessing, bioanalytical nanosensors, nanomaterials, bioselective surfaces, environmental processing, pathogen detection, plant/animal production, biosecurity, molecular and cellular biology, protection of the environment through the reduction and conversion of agricultural materials into valuable products, design and development of new nanocatalysts to convert vegetable oils into biobased fuels and biodegradable industrial solvents, and in controlled ecological life support system, to name a few

Nanomaterials: Look at the Earth

Nanotechnology promises to be the greatest technological breakthrough in history, doing for our control of matter what computers did for our control of information. The origins of nanoscience can be traced to clay mineralogy and crystallography when it was discovered that clay minerals were crystalline and of micrometer size. The unit cell dimensions of clay minerals are in nanometer scale in all three axes (x, y, and z). The advantages of clays are: (i) their ordered arrangements, (ii) their large adsorption capacity, (iii) their shielding against sunlight (ultraviolet radiation), (iv) their ability to concentrate organic chemicals, and (v) their ability to serve as polymerization templates. Clay minerals in nanoforms played a catalytic role in the synthesis of the ribosome in RNA that led to genesis of life on Earth. The history of Earth suggests that the late Precambrian oxygenation led to the inception of a ‘clay mineral factory’ that triggered the radical evolutionary diversification of Neoproterozoic life due to enhanced burial of organic carbon. High activity clays protected organic matter from reoxygenation, allowing a corresponding quantity of O2 to accumulate in the environment. The inseparable association of clays with lifeforms makes them most desirable in manufacturing nanoparticles. Clays have been extensively used in industry, but as concern for environmental sustainability grows, clay minerals find new takers from all conceivable forms of industries. Nanotechnology literature is flooded with clay-polymers for their possible use in high strength material manufacturing, for ecological life support systems, removal of contaminants from water and wastes, and as catalysts in chemical reactions to reduce energy consumption

Clays: Colloidal Properties in Nanodomain

The ever-growing application of clays in nanotechnology rests on fundamental principles of colloid chemistry. They make soils as nature’s great electrostatic chemical reactor. Highly anisotropic and often irregular particle shape, broad particle size distribution, different types of charges within the unit cells, heterogeneity of layer charges, pronounced CEC, dis-articulation and flexibility of layers, and different modes of aggregation make clays different from other colloidal materials. Their inseparable association with the genesis of life on Earth and evolutionary diversification of Neoproterozoic life is a safety-belt of nanotechnology. 

Nanotechnology promises to be the greatest technological breakthrough in history, doing for our control of matter what computers did for our control of information. The origins of nanoscience can be traced to clay mineralogy and crystallography when it was discovered that clay minerals were crystalline and of micrometer size. The unit cell dimensions of clay minerals are in nanometer scale in all three axes (x, y, and z). The advantages of clays are: (i) their ordered arrangements, (ii) their large adsorption capacity, (iii) their shielding against sunlight (ultraviolet radiation), (iv) their ability to concentrate organic chemicals, and (v) their ability to serve as polymerization templates. Clays protected organic matter from reoxygenation during the late Precambrian period, allowing a corresponding quantity of O2 to accumulate in the environment. The inseparable association of clays with lifeforms makes them most desirable in manufacturing nanoparticles. Clays have been extensively used in industry, but as concern for environmental sustainability grows, clay minerals find new takers from all conceivable forms of industries. Nanotechnology literature is flooded with clay-polymers for their possible use in high strength material manufacturing, for ecological life support system, removal of contaminants from water and wastes, and as catalysts in chemical reactions to reduce energy consumption. 
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Nanoscience and Nano-Technology: Cracking Prodigal Farming

Nano-science coupled with nano-technology has emerged as possible cost-cutting measure to prodigal farming and environmental clean-up operations. It has ushered as a new interdisciplinary field by converging various science disciplines, and is highly relevant to agricultural and food systems. Environmental Protection Agency of USA defined nanotechnology as the understanding and control of matter at dimensions of roughly 1-100 nm, where unique physical properties make novel applications possible. By this definition all soil-clays, many chemicals derived from soil organic matter (SOM), several soil microorganisms fall into this category. Apart from native soil-materials, many new nanotech products are entering into soil system, some of which are used for agricultural production and some others for many other purposes.

Nano-science (also nanotechnology) has found applications in controlling release of nitrogen, characterization of soil minerals, studies of weathering of soil minerals and soil development, micro-morphology of soils, nature of soil rhizosphere, nutrient ion transport in soil-plant system, emission of dusts and aerosols from agricultural soil and their nature, zeoponics, and precision water farming. In its stride, nanotechnology converges soil mineralogy with imaging techniques, artificial intelligence, and encompass bio molecules and polymers with microscopic atoms and molecules, and macroscopic properties (thermodynamics) with microscopic properties (kinetics, wave theory, uncertainty principles, etc.), to name a few. 

Some of the examples include clinoloptolite and other zeolite based substrates, and Fe-, Mn-, and Cu- substituted synthetic hydroxyapatites that have made it possible to grow crops in space stations and at Antarctica. This has eliminated costs of repeated launching of space crafts. A disturbing fact is that the fertilizer use efficiency is 20-50 percent for nitrogen, and 10-25 percent for phosphorus (<1% for rock phosphate in alkaline calcareous soils). With nano-fertilizers emerging as alternatives to conventional fertilizers, build ups of nutrients in soils and thereby eutrophication and drinking water contamination may be eliminated. In fact, nano-technology has opened up new opportunities to improve nutrient use efficiency and minimize costs of environmental protection. It has helped to divulge to recent findings that plant roots and microorganisms can directly lift nutrient ions from solid phase of minerals (that includes so-called susceptible (i.e., easily weatherable, as well as non-susceptible minerals)

Data-Driven Robust Optimization for Energy-Aware and Safe Navigation of Electric Vehicles

In this paper, we simultaneously tackle the problem of energy optimal and safe navigation of electric vehicles in a data-driven robust optimization framework. We consider a dynamic model of the electric vehicle which includes kinematic variables in both inertial and body coordinate systems in order to capture both longitudinal and lateral motion as well as state-of-energy of the battery. We leverage past data of obstacle motion to construct a future occupancy set with probabilistic guarantees, and formulate robust collision avoidance constraints with respect to such an occupancy set using convex programming duality. Consequently, we present the finite horizon optimal control problem subject to robust collision avoidance constraints while penalizing resulting energy consumption. Finally, we show the effectiveness of the proposed approach in reducing energy consumption and ensuring safe navigation via extensive simulations involving curved roads and multiple obstacles

Effect of Refrigerant Charge, Compressor Speed and Air Flow Through the Evaporator on the Performance of an Automotive Air Conditioning System

During last few decades research on Automotive Air Conditioning System (AACS) reached a milestone in terms of comfort, safety and economy. However investigation on system performance due to AACS’s variable operating conditions is limited. The performance of any AACS mostly depends on compressor speed, blower speed, refrigerant charge level and ambient condition. However, the combined effect of these parameters on the performance of AACS could be non-intuitive. Reduction in compressor speed and blower speed reduces the cooling capacity. Again, higher blower speed induces large volume of fresh air inside the cabin, which requires more compression work to maintain the same comfort level. Further the best performance of the system is achieved at an optimum charge level which is not independent of the other operating conditions. Therefore, it is essential to assess the performance of AACS for a wide combination of operating variables so that the range of optimum operating zone can be identified. With this purpose, an off board test bench has been developed for evaluating the performance of an automotive air conditioning system. The facility consists of the mechanical hardware used in an automobile along with a large number of additional sensors and a standalone control system that mimics the operations in a car. The experiments were carried out with varying compressor and blower speed along with a variable refrigerant charge for a given ambient condition. Total sixty set of experiments were conducted at 200, 300, 400, 500 and 600 g of refrigerant charge level. In each charge level the speed of the compressor was fixed at 1000, 1300, 1600 and 1900 rpm by using a variable frequency drive. Again in each compressor speed, the blower speed of the evaporator was selected at three different set points. The cooling capacity, compression work and COP of the system are reported in this paper over this wide operating range. It is observed that with the increase in compressor speed, cooling capacity and compression work increases along with a decrease in the COP of the system. The results indicate that the AACS could operate over a wide range of charge levels, 15% below to 15% above the design value without any significant impact on its performance. Beyond this range, the performance of the system was found to be strongly dependent upon the charge level. The degree of superheat at the evaporator outlet and degree of subcooling at the condenser outlet were shown to be significantly dependent on the level of refrigerant charge. Though the system performance depends on the speed of both the compressor and the blower, the effect of the latter on the refrigeration cycle is only marginal. The optimum operating condition with compressor and blower speed along with refrigerant charge level has also been identified