1,956 research outputs found

    Neem oil as biopesticides

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    Agricultural biotechnology is a wide logical method used to improve plants, animals, and microorganisms. The biotechnology cycle in the agricultural segment incorporates improving the harvests, living things, and microorganism's quality and resistibility by hereditary adjustment. Other than that, biotechnology in agriculture additionally known from the utilization of more secure natural sources to create an item that will be ready to ensure and build the creation of yields and domesticated animals, for example, manure and biopesticides. The World Health Organization (WHO) likewise had reported that the synthetic based pesticides would arrive at their constraints of utilization as it loses their adequacy after some time. This can be shown by the disclosure of pesticides obstruction bugs. The neem plant was accounted for as the top rundown spices that can possibly go about as a biopesticide; this is because of the presence of various dynamic mixes known as limonoids. The significant compound is the azadirachtin which assumes an essential job as bug sprays, and it executes the focused-on bugs by troubling their development and generative system. The neem oil biopesticides additionally are less harmful towards living beings and less contamination toward nature. In this way, the neem removed biopesticides are presently popularized and have been sold and utilized in different nations

    Modelling and simulation of biomass fast pyrolysis process: Kinetics, reactor, and condenser systems

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    The research focuses on understanding implementation of multi-scale modeling and simulation of biomass fast pyrolysis process. Lumped and detailed pyrolysis kinetic models are proposed based on experimental and literature data validation. The detailed kinetics is coupled with an engineering model of bubbling fluidized bed reactor to predict pyrolysis gas and bio-oil composition. A simulation strategy to fractionally condense major pyrolysis components into distinct chemical families is proposed using ASPENPlus

    Modeling and performance analysis of biomass fast pyrolysis in a solar-thermal reactor

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    Solar-thermal conversion of biomass through pyrolysis process is an alternative option to store energy in the form of liquid fuel, gas and bio-char. Fast pyrolysis is a highly endothermic process and essentially requires high heating rate and temperature >400 °C. This study presents a theoretical study on biomass fast pyrolysis in a solar-thermal reactor heated by a parabolic trough concentrator. The reactor is part of a novel closed loop pyrolysis-gasification process. A Eulerian-Eulerian flow model, with constitutive closure equation derived from the kinetic theory of granular flow and incorporating heat transfer, drying and pyrolysis reaction equations, was solved using ANSYS Fluent computational fluid dynamics (CFD) software. The highly endothermic pyrolysis was assumed to be satisfied by a constant solar heat flux concentrated on the reactor external wall. At the operating conditions considered, the reactor overall energy efficiency was found equal to 67.8% with the product consisting of 51.5% bio-oil, 43.7% char and 4.8% non-condensable gases. Performance analysis is presented to show the competitiveness of the proposed reactor in terms of thermal conversion efficiency and environmental impact. It is hoped that this study will contribute to the global effort on securing diverse and sustainable energy generation technologies

    Fully integrated microsystem for bacterial genotyping

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    Methods for bacterial detection and identification has garnered renewed interest in recent years due to the infections they may cause and the antimicrobial resistances they can develop, the potential for bioterrorism threats and possible contamination of food/water supplies. Therefore, the rapid, specific and accurate detection of pathogens is crucial for the prevention of pathogen-related disease outbreaks and facilitating disease management as well as the containment of suspected contaminated food and/or water supplies. In this dissertation an integrated modular-based microfluidic system composed of a fluidic cartridge and a control instrument has been developed for bacterial pathogen detection. The integrated system can directly carry out the entire molecular processing pipeline in a single disposable fluidic cartridge and can detect sequence variations in selected genes to allow for the identification of the bacterial species and even its strain. The unique aspect of this fluidic cartridge is its modular format with a task-specific module interconnected to a fluidic motherboard to permit the selection of a material appropriate for the given processing step(s). In addition, to minimize the amount of finishing steps for assembling the fluidic cartridge, many of the functional components were produced during the polymer molding step used to create the fluidic network. The operation of the fluidic cartridge was provided by electronic, mechanical, optical and hydraulic controls located off-chip and assembled into a small footprint instrument. The fluidic cartridge was capable of performing cell lysis, solidphase extraction of genomic DNA from the whole cell lysate, continuous flow PCR amplification of specific gene fragments, continuous flow ligase detection reaction to discriminate sequence variations and universal DNA array readout, which consisted of DNA probes patterned onto a planar polymer waveguide for evanescent excitation. The performance of the fluidic system was demonstrated through its successful application to the genetic detection of bacterial pathogens, such as Escherichia coli O157:H7, Salmonella, methicillin-resistant Staphylococcus aureus and multi-drug resistant Mycobacterium tuberculosis, which are major threats for global heath. The modular system, which could successfully identify several strains of bacteria in \u3c40 min with minimal human intervention and also perform strain identification, represents a significant contribution to pathogen detection

    Intensification of chemical looping processes by catalyst assistance and combination

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    Chemical looping can be considered a technology platform, which refers to one common basic concept that can be used for various applications. Compared with a traditional catalytic process, the chemical looping concept allows fuels’ conversion and products’ separation without extra processes. In addition, the chemical looping technology has another major advantage: combinability, which enables the integration of different reactions into one process, leading to intensification. This review collects various important state-of-the-art examples, such as integration of chemical looping and catalytic processes. Hereby, we demonstrate that chemical looping can in principle be implemented for any catalytic reaction or at least assist in existing processes, provided that the targeted functional group is transferrable by means of suitable carriers

    Automated advanced calibration and optimization of thermochemical models applied to biomass gasification and pyrolysis

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    This paper presents a methodology that combines physicochemical modeling with advanced statistical analysis algorithms as an efficient workflow, which is then applied to the optimization and design of biomass pyrolysis and gasification processes. The goal was to develop an automated flexible approach for the analyses and optimization of such processes. The approach presented here can also be directly applied to other biomass conversion processes and, in general, to all those processes for which a parametrized model is available. A flexible physicochemical model of the process is initially formulated. Within this model, a hierarchy of sensitive model parameters and input variables (process conditions) is identified, which are then automatically adjusted to calibrate the model and to optimize the process. Through the numerical solution of the underlying mathematical model of the process, we can understand how species concentrations and the thermodynamic conditions within the reactor evolve for the two processes studied. The flexibility offered by the ability to control any model parameter is critical in enabling optimization of both efficiency of the process as well as its emissions. It allows users to design and operate feedstock-flexible pyrolysis and gasification processes, accurately control product characteristics, and minimize the formation of unwanted byproducts (e.g., tar in biomass gasification processes) by exploiting various productivity-enhancing simulation techniques, such as parameter estimation, computational surrogate (reduced order model) generation, uncertainty propagation, and multi-response optimization

    The Kuramoto model: A simple paradigm for synchronization phenomena

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    Synchronization phenomena in large populations of interacting elements are the subject of intense research efforts in physical, biological, chemical, and social systems. A successful approach to the problem of synchronization consists of modeling each member of the population as a phase oscillator. In this review, synchronization is analyzed in one of the most representative models of coupled phase oscillators, the Kuramoto model. A rigorous mathematical treatment, specific numerical methods, and many variations and extensions of the original model that have appeared in the last few years are presented. Relevant applications of the model in different contexts are also included

    A Unified Research Data Infrastructure for Catalysis Research – Challenges and Concepts

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    Modern research methods produce large amounts of scientifically valuable data. Tools to process and analyze such data have advanced rapidly. Yet, access to large amounts of high‐quality data remains limited in many fields, including catalysis research. Implementing the concept of FAIR data (Findable, Accessible, Interoperable, Reusable) in the catalysis community would improve this situation dramatically. The German NFDI initiative (National Research Data Infrastructure) aims to create a unique research data infrastructure covering all scientific disciplines. One of the consortia, NFDI4Cat, proposes a concept that serves all aspects and fields of catalysis research. We present a perspective on the challenging path ahead. Starting out from the current state, research needs are identified. A vision for a integrating all research data along the catalysis value chain, from molecule to chemical process, is developed. Respective core development topics are discussed, including ontologies, metadata, required infrastructure, IP, and the embedding into research community. This Concept paper aims to inspire not only researchers in the catalysis field, but to spark similar efforts also in other disciplines and on an international level.DFG, 441926934, NFDI4Cat – NFDI für Wissenschaften mit Bezug zur Katalys

    Development of stable oxygen carrier materials for chemical looping processes : a review

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    This review aims to give more understanding of the selection and development of oxygen carrier materials for chemical looping. Chemical looping, a rising star in chemical technologies, is capable of low CO2 emissions with applications in the production of energy and chemicals. A key issue in the further development of chemical looping processes and its introduction to the industry is the selection and further development of an appropriate oxygen carrier (OC) material. This solid oxygen carrier material supplies the stoichiometric oxygen needed for the various chemical processes. Its reactivity, cost, toxicity, thermal stability, attrition resistance, and chemical stability are critical selection criteria for developing suitable oxygen carrier materials. To develop oxygen carriers with optimal properties and long-term stability, one must consider the employed reactor configuration and the aim of the chemical looping process, as well as the thermodynamic properties of the active phases, their interaction with the used support material, long-term stability, internal ionic migration, and the advantages and limits of the employed synthesis methods. This review, therefore, aims to give more understanding into all aforementioned aspects to facilitate further research and development of chemical looping technology
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