scholarly journals Extraction of Pigments from Microalgae and Cyanobacteria—A Review on Current Methodologies

2021 ◽  
Vol 11 (11) ◽  
pp. 5187
Author(s):  
Fernando Pagels ◽  
Ricardo N. Pereira ◽  
António A. Vicente ◽  
A. Catarina Guedes
Keyword(s):  
Ohmic Heating ◽  
Electric Pulse ◽  
World Market ◽  
Industrial Applications ◽  
Cell Disruption ◽  
Advantages And Disadvantages ◽  
Pigment Extraction ◽  
High Pressure Co2 ◽  
Pigment Type ◽  
Bioactive Potential

Pigments from microalgae and cyanobacteria have attracted great interest for industrial applications due to their bioactive potential and their natural product attributes. These pigments are usually sold as extracts, to overcome purification costs. The extraction of these compounds is based on cell disruption methodologies and chemical solubility of compounds. Different cell disruption methodologies have been used for pigment extraction, such as sonication, homogenization, high-pressure, CO2 supercritical fluid extraction, enzymatic extraction, and some other promising extraction methodologies such as ohmic heating and electric pulse technologies. The biggest constrain on pigment bioprocessing comes from the installation and operation costs; thus, fundamental and applied research are still needed to overcome such constrains and give the microalgae and cyanobacteria industry an opportunity in the world market. In this review, the main extraction methodologies will be discussed, taking into account the advantages and disadvantages for each kind of pigment, type of organism, cost, and final market.

scholarly journals ANALYSIS OF EXISTING METHODS FOR URANIUM-PLUTONIUM MIXED NITRIDE FUEL FAB-RICATION IN RUSSIA AND ABROAD

2020 ◽  
Vol 63 (6) ◽  
pp. 12-18
Author(s):  
Maxim S. Fedorov ◽  
Nikolay A. Baydakov ◽  
Alexander N. Zhiganov ◽  
Dmitry V. Zozulya
Keyword(s):  
High Voltage ◽  
Electric Pulse ◽  
Industrial Applications ◽  
Ceramic Technology ◽  
Laboratory Methods ◽  
Advantages And Disadvantages ◽  
Nitride Fuel ◽  
Powder Pressing ◽  
Uranium Nitride ◽  
Uranium Plutonium

This paper presents a review and a brief analysis of existing methods for producing mixed uranium nitride and plutonium, developed by both Russian and foreign scientists. The main parameters of the processes are considered, and their advantages and disadvantages are studied. Currently, the main areas of nitride fuel production are the metal hydride method and carbothermic reduction from the starting oxides. The methods are traditional ceramic technology. The starting products for the manufacture of nitride fuel powder can be either oxides (uranium dioxide and plutonium dioxide) or metals (uranium, plutonium and their alloys). To date, the technology for the manufacture of nitride fuel powder has not been finally selected. When considering existing methods, significant emphasis was placed on industrial applications and the simplicity of the hardware design processes. The laboratory methods are reflected in the work, which make it possible to simplify the process and reduce the costs of obtaining powders of mixed uranium and plutonium nitrides. However, they have significant difficulties in the technological implementation and low productivity of the processes. Of special interest among laboratory methods for producing mixed uranium and plutonium nitrides is the method of high-voltage electric pulse consolidation. This method allows sintering of tablets at the stage of powder pressing from mixed uranium and plutonium nitrides by passing a short high-voltage discharge with a power of several kW directly through the powder.

Modern pretreatment techniques for phytochemical extraction

2019 ◽  
Vol 49 (3) ◽  
pp. 441-454 ◽  
Author(s):  
Satakshi Aggarwal ◽  
Tanu Jain
Keyword(s):  
Ohmic Heating ◽  
Anthocyanin Content ◽  
Thermal Pretreatment ◽  
Content Type ◽  
Advantages And Disadvantages ◽  
Hybrid Approaches ◽  
Final Yield ◽  
Pre Treatment ◽  
Collective Information ◽  
Phytochemical Extraction

Purpose Modern thermal and non-thermal pretreatment techniques, namely, enzymatic treatment, gas phase plasma treatment and ohmic heating have become more pronounced over conventional techniques for enhanced coloured phytochemicals (pigments) extraction. Presently, numbers of pretreatment techniques are available with some unique feature. It is difficult to choose best pretreatment method to be employed for phytochemicals extraction from different sources. Therefore, this paper aims to discuss different modern pretreatment techniques for extraction with their potential results over conventional techniques. Design/methodology/approach Research and review articles targeting to the thermal and non-thermal pretreatment techniques were collected from Google Scholar. The required information has been tabulated and discussed which included qualities of modern pretreatment techniques over conventional techniques, phytochemical extraction and best pretreatment methods for optimized results. Findings Every pre-treatment has its own advantages and disadvantages for a particular phytochemical and its extraction from various sources. Enzymes can be used in combinations to enhance final yield like extraction of carotenoids (pectinase, cellulase and hemicellulase) from chillies and lycopene (pectinase and cellulase) from tomato. Utilization of each method depends upon many factors such as source of pigment, cost and energy consumption. CO2 pretreatment gives good results for carotenoid extraction from algae sources. Ohmic heating can yield high anthocyanin content. Modifications in conventional blanching has reduced final waste and improvised the properties of pigment. Originality/value This study comprises collective information regarding modern pre-treatment for extraction over conventional pre-treatments. The study also covers future trends and certain new hybrid approaches which are still less flourished.

The United States Navy “Standard Day” for Marine Gas Turbines

2017 ◽  
Author(s):  
John Hartranft ◽  
Bruce Thompson ◽  
Dan Groghan
Keyword(s):  
United States ◽  
Gas Turbine ◽  
United States Navy ◽  
Gas Turbines ◽  
The United States ◽  
Industrial Applications ◽  
Jet Engines ◽  
Jet Engine ◽  
Advantages And Disadvantages ◽  
Power Capability

Following the successful development of aircraft jet engines during World War II (WWII), the United States Navy began exploring the advantages of gas turbine engines for ship and boat propulsion. Early development soon focused on aircraft derivative (aero derivative) gas turbines for use in the United States Navy (USN) Fleet rather than engines developed specifically for marine and industrial applications due to poor results from a few of the early marine and industrial developments. Some of the new commercial jet engine powered aircraft that had emerged at the time were the Boeing 707 and the Douglas DC-8. It was from these early aircraft engine successes (both commercial and military) that engine cores such as the JT4-FT4 and others became available for USN ship and boat programs. The task of adapting the jet engine to the marine environment turned out to be a substantial task because USN ships were operated in a completely different environment than that of aircraft which caused different forms of turbine corrosion than that seen in aircraft jet engines. Furthermore, shipboard engines were expected to perform tens of thousands of hours before overhaul compared with a few thousand hours mean time between overhaul usually experienced in aircraft applications. To address the concerns of shipboard applications, standards were created for marine gas turbine shipboard qualification and installation. One of those standards was the development of a USN Standard Day for gas turbines. This paper addresses the topic of a Navy Standard Day as it relates to the introduction of marine gas turbines into the United States Navy Fleet and why it differs from other rating approaches. Lastly, this paper will address examples of issues encountered with early requirements and whether current requirements for the Navy Standard Day should be changed. Concerning other rating approaches, the paper will also address the issue of using an International Organization for Standardization, that is, an International Standard Day. It is important to address an ISO STD DAY because many original equipment manufacturers and commercial operators prefer to rate their aero derivative gas turbines based on an ISO STD DAY with no losses. The argument is that the ISO approach fully utilizes the power capability of the engine. This paper will discuss the advantages and disadvantages of the ISO STD DAY approach and how the USN STD DAY approach has benefitted the USN. For the future, with the advance of engine controllers and electronics, utilizing some of the features of an ISO STD DAY approach may be possible while maintaining the advantages of the USN STD DAY.

On the Performances Investigation of Different Surface Mounted Permanent Magnet Machines

2015 ◽  
Vol 6 (3) ◽  
pp. 509
Author(s):  
Mansouri Ali ◽  
Msaddek Hejra ◽  
Trabelsi Hafedh
Keyword(s):  
Permanent Magnet ◽  
Main Idea ◽  
Industrial Applications ◽  
Permanent Magnet Machines ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Output Torque ◽  
Iron Losses ◽  
Outer Rotor ◽  
Current Loading

<table border="1" cellspacing="0" cellpadding="0" width="593"><tbody><tr><td width="387" valign="top"><p>In recent years, permanent magnet machines have become a common choice in many industrial applications. Therefore, several structures have been developed, and the choice of a topology designed for a specified application requires the knowledge of the advantages and disadvantages of different topologies. The present work deals with the evaluation of the performances of different radial flux surface-mounted permanent magnet motors designed for an electric vehicle motor application. The objective of this survey is to show the effect of the rotor position (inner or outer) and the magnets segmentation on the machine output torque and iron losses. In this context, four machines with: (i) inner rotor, (ii) inner rotor segmented magnets, (iii) outer rotor and (iv) outer rotor segmented magnets have been designed and studied. All these machines have the same geometrical dimensions and current loading. The main idea is to develop a machine with smoothness torque, lower torque ondulation, lower iron losses, and which is mechanically robust. Firstly, the output torque of the different structure is computed. Secondly, by means of an improved analytical model coupled with 2 dimensional transient finite element analysis (FEA), the machines iron losses are predicted.</p></td></tr></tbody></table>

scholarly journals Insights into Mapping Solutions Based on OPC UA Information Model Applied to the Industry 4.0 Asset Administration Shell

Computers ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 28 ◽  
Author(s):  
Salvatore Cavalieri ◽  
Marco Giuseppe Salafia
Keyword(s):  
Industry 4.0 ◽  
Manufacturing Systems ◽  
Industrial Revolution ◽  
Information Model ◽  
Industrial Applications ◽  
Reference Architecture ◽  
Architecture Model ◽  
Open Platform ◽  
Advantages And Disadvantages ◽  
The One

In the context of Industry 4.0, lot of effort is being put to achieve interoperability among industrial applications. As the definition and adoption of communication standards are of paramount importance for the realization of interoperability, during the last few years different organizations have developed reference architectures to align standards in the context of the fourth industrial revolution. One of the main examples is the reference architecture model for Industry 4.0, which defines the asset administration shell as the corner stone of the interoperability between applications managing manufacturing systems. Inside Industry 4.0 there is also so much interest behind the standard open platform communications unified architecture (OPC UA), which is listed as the one recommendation for realizing the communication layer of the reference architecture model. The contribution of this paper is to give some insights behind modelling techniques that should be adopted during the definition of OPC UA Information Model exposing information of the very recent metamodel defined for the asset administration shell. All the general rationales and solutions here provided are compared with the current OPC UA-based existing representation of asset administration shell provided by literature. Specifically, differences will be pointed out giving to the reader advantages and disadvantages behind each solution.

scholarly journals Transformerless Multilevel Voltage-Source Inverter Topology Comparative Study for PV Systems

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3261 ◽  
Author(s):  
Adyr A. Estévez-Bén ◽  
Alfredo Alvarez-Diazcomas ◽  
Juvenal Rodríguez-Reséndiz
Keyword(s):  
Leakage Current ◽  
Clean Energy ◽  
Industrial Applications ◽  
Renewable Energies ◽  
International Standards ◽  
Voltage Source ◽  
Switching Frequency ◽  
Multilevel Inverters ◽  
Pv Systems ◽  
Advantages And Disadvantages

At present, renewable energies represent 25% of the global power generation capacity. The increase in clean energy facilities is mainly due to the high levels of pollution generated by the burning of fossil fuels to satisfy the growing electricity demand. The global capacity of generating electricity from solar energy has experienced a significant increase, reaching 505 GW in 2018. Today, multilevel inverters are used in PV systems to convert direct current into alternating current. However, the use of multilevel inverters in renewable energies applications presents different challenges; for example, grid-connected systems use a transformer to avoid the presence of leakage currents. The grid-connected systems must meet at least two international standards analyzed in this work: VDE 0126-1-1 and VDE-AR-N 4105, which establish a maximum leakage current of 300 mA and harmonic distortion maximum of 5%. Previously, DC/AC converters have been studied in different industrial applications. The state-of-the-art presented in the work is due to the growing need for a greater use of clean energy and the use of inverters as an interface between these technologies and the grid. Also, the paper presents a comparative analysis of the main multilevel inverter voltage-source topologies used in transformerless PV systems. In each scheme, the advantages and disadvantages are presented, as well as the main challenges. In addition, current trends in grid-connected systems using these schemes are discussed. Finally, a comparative table based on input voltage, switching frequency, output levels, control strategy used, efficiency, and leakage current is shown.

Natural pigment extraction from five filamentous fungi for industrial applications and dyeing of leather

2010 ◽  
Vol 79 (2) ◽  
pp. 262-268 ◽  
Author(s):  
Palanivel Velmurugan ◽  
Seralathan Kamala-Kannan ◽  
Vellingiri Balachandar ◽  
Perumalsamy Lakshmanaperumalsamy ◽  
Jong-Chan Chae ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Industrial Applications ◽  
Natural Pigment ◽  
Pigment Extraction

Enzymatic synthesis of kojic acid esters and their potential industrial applications

2013 ◽  
Vol 67 (6) ◽  
Author(s):  
Ahmad Lajis ◽  
Mahiran Basri ◽  
Rosfarizan Mohamad ◽  
Muhajir Hamid ◽  
Siti Ashari ◽  
...  
Keyword(s):  
Kojic Acid ◽  
Biological Activities ◽  
Immobilized Lipase ◽  
Industrial Applications ◽  
Enzyme Loading ◽  
Initial Water ◽  
Advantages And Disadvantages ◽  
Anti Oxidant ◽  
Acyl Donors ◽  
Acid Esters

AbstractIn this paper, enzymatic methods for the synthesis of 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one (kojic acid) esters are reviewed. Important process parameters related to the synthesis of kojic acid esters such as the type of immobilized lipase, solvent, temperature, initial water activity, water content, pH, metal salts, enzyme loading, substrates mole ratio, and acyl donors are highlighted and discussed. The properties of kojic acid esters related to their solubility, stability, cytotoxicity, depigmenting activity, tyrosinase inhibitory, metal-chelating, anti-oxidant, and other biological activities are also highlighted. At present, kojic acid and its esters are widely used in cosmetic and skin health industries as skin whitening agents. The advantages and disadvantages of various kojic acid esters are compared and possible industrial applications of these derivatives are also discussed.

scholarly journals Linear and Nonlinear Schemes Applied to Pitch Control of Wind Turbines

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hua Geng ◽  
Geng Yang
Keyword(s):  
Controller Design ◽  
Industrial Applications ◽  
Pitch Control ◽  
Advantages And Disadvantages ◽  
Wind Energy Conversion Systems ◽  
Energy Conversion Systems ◽  
Linear And Nonlinear ◽  
Nonlinear Schemes ◽  
Nonlinear Feature ◽  
Digital Processor

Linear controllers have been employed in industrial applications for many years, but sometimes they are noneffective on the system with nonlinear characteristics. This paper discusses the structure, performance, implementation cost, advantages, and disadvantages of different linear and nonlinear schemes applied to the pitch control of the wind energy conversion systems (WECSs). The linear controller has the simplest structure and is easily understood by the engineers and thus is widely accepted by the industry. In contrast, nonlinear schemes are more complicated, but they can provide better performance. Although nonlinear algorithms can be implemented in a powerful digital processor nowadays, they need time to be accepted by the industry and their reliability needs to be verified in the commercial products. More information about the system nonlinear feature is helpful to simplify the controller design. However, nonlinear schemes independent of the system model are more robust to the uncertainties or deviations of the system parameters.

scholarly journals Construction of modern and high-tech agricultural temporary vegetable storehouses

2020 ◽  
pp. 1-1
Author(s):  
Vladislav Ushakov ◽  
Artem Subbotin ◽  
Dmitry Lisin
Keyword(s):  
Agricultural Production ◽  
Negative Impact ◽  
World Market ◽  
High Tech ◽  
Winter Period ◽  
Agricultural Industry ◽  
Advantages And Disadvantages ◽  
The World ◽  
Quality Of Products

Introduction. This article addresses the question of existing problems of development of construction industry in agriculture. Outdated old construction technologies and building structures give a reason for optimization and introduction of modern technologies in agricultural production. The outdated technologies of agricultural construction have a negative impact on the position of agricultural industry in the world stage of trade and economy of countries, while optimization and inevitable modernization of agricultural production and construction allow securing a foothold in the world market. Aspiration to take the lead in the world market is one of the most important tasks of agricultural industry. The agricultural industry also plays an oversize role in human life and the health, efficiency, development and activity of citizens depend directly on the quality of products delivered to the shop windows. This scope of research of this article is a comparison of traditional, temporary, field vegetable storehouses operating in winter time with modern technology of construction of these facilities in terms of technology, efficiency, environmental friendliness, mobility, availability, functionality and profitability. Materials and methods. In the course of this work, the following research methods were used: familiarization with the relevant statutes and regulations related to the study area, comparison of traditional and modern methods of vegetable storage in the field environment during the winter period and identification of the main advantages and disadvantages. Results. The positive and negative sides of the design and methods of construction of modern and traditional outdated technology have been revealed, as well as optimization of construction solutions necessary to ensure conditions for maintaining the quality of products in due form. Conclusions. Modern construction concepts and development of agricultural construction is an important area that allows provoking the trend of economic growth of countries, to take a leading position in the world market, to improve the quality of life of citizens, to improve the ecological system of the area and develop business activities.

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