scholarly journals Red Light Variation an Effective Alternative to Regulate Biomass and Lipid Profiles in Phaeodactylum tricornutum

2020 ◽  
Vol 10 (7) ◽  
pp. 2531
Author(s):  
Nikunj Sharma ◽  
Gabriel Fleurent ◽  
Fatima Awwad ◽  
Michael Cheng ◽  
Fatma Meddeb-Mouelhi ◽  
...  
Keyword(s):  
Lipid Content ◽  
Phaeodactylum Tricornutum ◽  
Low Cost ◽  
Red Light ◽  
Total Biomass ◽  
Light Shift ◽  
Growth Phases ◽  
Metabolic Functions ◽  
Photosynthetic Organism ◽  
Different Temperatures

Marine water diatom Phaeodactylum tricornutum is a photosynthetic organism that is known to respond to the changing light environment and adapt to different temperatures to prevent photoinhibition and maintain its metabolic functions. The objective of the present study was to test whether light shift variations in different growth phases impact the growth and lipid metabolism of P. tricornutum. Thus, we investigated R exposure in different growth phases to find the most effective light shift condition. The results showed that substituting white light (W) by red light (R) under autotrophic conditions, a condition called red shift (RS), increased biomass and lipid content compared to levels found under continuous W or R exposure alone. We observed an increase by 2-fold biomass and 2.3-fold lipid content in RS as compared to W. No significant change was observed in the morphology of lipid droplets, but the fatty acid (FA) composition was altered. Specifically, polyunsaturated FAs were increased, whereas monounsaturated FAs decreased in P. tricornutum grown in RS compared to W control. Therefore, we propose that a light shift during the beginning of the stationary phase is a low-cost cultivation strategy to boost the total biomass and lipids in P. tricornutum.

scholarly journals Superior Degradation Performance of Nanoporous Copper Catalysts on Methyl Orange

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 913
Author(s):  
Jinyi Wang ◽  
Sen Yang
Keyword(s):  
Activation Energy ◽  
Methyl Orange ◽  
High Efficiency ◽  
Low Cost ◽  
Degradation Process ◽  
Copper Catalysts ◽  
Reaction Rate Constant ◽  
Nanoporous Structure ◽  
Intra Particle Diffusion ◽  
Different Temperatures

The development of low-cost and high-efficiency catalysts for wastewater treatment is of great significance. Herein, nanoporous Cu/Cu2O catalysts were synthesized from MnCu, MnCuNi, and MnCuAl with similar ligament size through one-step dealloying. Meanwhile, the comparisons of three catalysts in performing methyl orange degradation were investigated. One of the catalysts possessed a degradation efficiency as high as 7.67 mg·g−1·min−1. With good linear fitting by the pseudo-first-order model, the reaction rate constant was evaluated. In order to better understand the degradation process, the adsorption behavior was considered, and it was divided into three stages based on the intra-particle diffusion model. Three different temperatures were applied to explore the activation energy of the degradation. As a photocatalytic agent, the nanoporous structure of Cu/Cu2O possessed a large surface area and it also had low activation energy, which were beneficial to the excellent degradation performance.

Direct Writing on Paper Substrate to Prepare Silver Electrode Structures for Flexible Sensors

2021 ◽  
Vol 21 (12) ◽  
pp. 6048-6053
Author(s):  
Qi Wang ◽  
Mingwei Li ◽  
Yao Xie ◽  
Yun Ou ◽  
Weiping Zhou
Keyword(s):  
Low Cost ◽  
Rapid Development ◽  
Silver Electrode ◽  
Silver Nanostructures ◽  
Direct Writing ◽  
Paper Substrate ◽  
Electronic Products ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Writing Technology

With the rapid development of the electronics industry, electronic products based on silicon and glass substrates electronic products will gradually be unable to meet the rising demand. Flexibility, environmental protection, and low costs are important for the development of electronic products. In this study, an efficient and low-cost method for preparing silver electrode structures by direct writing on paper has been demonstrated. Based on this method, a flexible paper-based sensor was prepared. The liquid printing ink used mainly comprises a precursor liquid without pre-prepared nanomaterials. The precursor liquid is transparent with good fluidity. Simple direct writing technology was used to write on the paper substrate using the precursor ink. When the direct-writing paper substrate was subsequently heated, silver nanostructures precipitated from the precursor liquid ink onto the paper substrate. The effect of different temperatures on the formation of the silver nanostructures and the influence of different direct writing processes on the structures were studied. Finally, a paper-based flexible sensor was prepared for finger-bending signal detection. The method is simple to operate and low in cost and can be used for the preparation of environment-friendly paper-based devices.

scholarly journals Optimum Multilayer-Graphene-Montmorillonite Composites From Sugar for Thermosolar Coatings Formulations

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Bàrbara Micó-Vicent ◽  
María López ◽  
Azucena Bello ◽  
Noelia Martínez ◽  
Francisco Martínez-Verdú
Keyword(s):  
Working Conditions ◽  
Low Cost ◽  
Multilayer Graphene ◽  
Optimum Conditions ◽  
Laminar Structure ◽  
Solar Absorptance ◽  
Solar Plant ◽  
Different Temperatures ◽  
Complex Deposition ◽  
Deposition Techniques

Solar thermal coatings are designed to achieve the highest incident solar flux into the receiver of a tower solar plant. These materials are subjected to extreme working conditions of temperature and solar concentrated radiation. Much effort is being made to develop a durable and high absorptive coating that can provide an excellent solar to heat conversion efficiency. Complex deposition techniques (PVD, CVD, electrodeposition, etc.) are developed and tested to achieve solar selectivity. High solar absorptance paints are an alternative technique, that is, easy to apply and implement in the field. In paint, pigments are the compound that provides high absorptance values, whose stability impacts the durability of optical properties. The search for new selective solar pigments for solar receivers is a promising route to improve the efficiency of this technology. In this work, novel nanocomposites were synthesized from low-cost organic materials such as table sugar. Promising results were obtained when intercalated and calcined in the laminar structure of montmorillonite, a type of smectite clay. The pigments were tested in a paint format on metallic coupons at different temperatures to obtain absorptivities above 96% of absorptance after 24 h at 700  °C. Further experiments are still needed to obtain optimum conditions to maximize the coating's absorptivity and durability at high temperature.

scholarly journals Performance Analysis of V2V and V2I LiFi Communication Systems in Traffic Lights

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Gerardo Hernandez-Oregon ◽  
Mario E. Rivero-Angeles ◽  
Juan C. Chimal-Eguía ◽  
Arturo Campos-Fentanes ◽  
Jorge G. Jimenez-Gallardo ◽  
...  
Keyword(s):  
Mobile Communications ◽  
Communication Systems ◽  
Vehicular Networks ◽  
Low Cost ◽  
Red Light ◽  
Green Light ◽  
Mathematical Expression ◽  
Traffic Light ◽  
Safe Driving ◽  
Traffic Lights

Vehicular networks is a key technology for efficiently communicating both user’s devices and cars for timely information regarding safe driving conditions and entertaining applications like social media, video streaming, and gaming services, among others. In view of this, mobile communications making use of cellular resources may not be an efficient and cost-effective alternative. In this context, the implementation of light-fidelity (LiFi) in vehicular communications could be a low-cost, high-data-rate, and efficient-bandwidth usage solution. In this work, we propose a mathematical analysis to study the average throughput in a road intersection equipped with a traffic light that operates as a server, which is assumed to have LiFi communication links with the front lights of the vehicles waiting for the green light. We further assume that the front vehicle (the car next to the traffic light) is able to communicate to the car immediately behind it by using its own tail lights and the front lights of such vehicle, and so on and so forth. The behavior of the road junction is modeled by a Markov chain, applying the Queueing theory with an M/M/1 system in order to obtain the average queue length. Then, Little’s theorem is applied to calculate the average waiting delay when the red light is present in the traffic light. Finally, the mathematical expression of the data throughput is derived.

Localized Corrosion of UNS A95052 Aluminum Alloy for Application in Multi-Effect Desalinator Plants

CORROSION ◽  
10.5006/2815 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 1023-1032
Author(s):  
Dannisa R. Chalfoun ◽  
Mariano A. Kappes ◽  
Mauricio Chocrón ◽  
Raul B. Rebak
Keyword(s):  
Aluminum Alloy ◽  
Crevice Corrosion ◽  
Low Cost ◽  
Localized Corrosion ◽  
Complete Evaluation ◽  
Electrochemical Tests ◽  
Metal Plates ◽  
Different Temperatures ◽  
Partially Occluded ◽  
Desalination Plants

Aluminum alloy UNS A95052 (AA5052) is very attractive for desalination applications because of its good corrosion resistance in seawater at temperatures up to 125°C, low cost, good thermal conductivity, and non-toxicity of its corrosion products. The pitting corrosion potential, Epit, and the pit repassivation potential, Er,pit, of AA5052 were measured in deaerated 65,000 ppm sodium chloride (NaCl) solutions at 30°C, 60°C, and 85°C. Epit decreased with temperature, in accord with literature results. Er,pit was a function of anodic charge passed during pit growth stage. A complete evaluation of suitability of this alloy from a corrosion perspective requires also studies of crevice corrosion at different temperatures, considering that multi-plate designs of desalinators have metal plates in contact with rubber gaskets and seals. Cyclic potentiodynamic polarization was used to estimate crevice repassivation potentials, Er,crev, at 30°C, 60°C, and 85°C, in specimens with an attached rubber O-ring as a crevice former. This crevice former simulated the partially occluded geometry expected in desalination plants. Stable crevice corrosion potentials, Ecrev, were similar to Epit, and, when polarized to a similar anodic charge density, Er,crev were similar to Er,pit. Based on this result, from a corrosion perspective, the presence of crevices in the desalination plant is not expected to present an additional risk during operation of the plant. Electrochemical tests were also performed in saturated AlCl3 solutions to explain the results using Galvele’s localized acidification model.

scholarly journals Biomass and lipid induction strategies in microalgae for biofuel production and other applications

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Hossein Alishah Aratboni ◽  
Nahid Rafiei ◽  
Raul Garcia-Granados ◽  
Abbas Alemzadeh ◽  
José Rubén Morones-Ramírez
Keyword(s):  
Lipid Content ◽  
Large Scale ◽  
Fossil Fuels ◽  
Low Cost ◽  
Lipid Production ◽  
Arable Land ◽  
Economic Cost ◽  
Biofuel Production ◽  
Scale Production ◽  
Microalgae Biomass

Abstract The use of fossil fuels has been strongly related to critical problems currently affecting society, such as: global warming, global greenhouse effects and pollution. These problems have affected the homeostasis of living organisms worldwide at an alarming rate. Due to this, it is imperative to look for alternatives to the use of fossil fuels and one of the relevant substitutes are biofuels. There are different types of biofuels (categories and generations) that have been previously explored, but recently, the use of microalgae has been strongly considered for the production of biofuels since they present a series of advantages over other biofuel production sources: (a) they don’t need arable land to grow and therefore do not compete with food crops (like biofuels produced from corn, sugar cane and other plants) and; (b) they exhibit rapid biomass production containing high oil contents, at least 15 to 20 times higher than land based oleaginous crops. Hence, these unicellular photosynthetic microorganisms have received great attention from researches to use them in the large-scale production of biofuels. However, one disadvantage of using microalgae is the high economic cost due to the low-yields of lipid content in the microalgae biomass. Thus, development of different methods to enhance microalgae biomass, as well as lipid content in the microalgae cells, would lead to the development of a sustainable low-cost process to produce biofuels. Within the last 10 years, many studies have reported different methods and strategies to induce lipid production to obtain higher lipid accumulation in the biomass of microalgae cells; however, there is not a comprehensive review in the literature that highlights, compares and discusses these strategies. Here, we review these strategies which include modulating light intensity in cultures, controlling and varying CO2 levels and temperature, inducing nutrient starvation in the culture, the implementation of stress by incorporating heavy metal or inducing a high salinity condition, and the use of metabolic and genetic engineering techniques coupled with nanotechnology.

scholarly journals Sustainable Organic Dyes from Winemaking Lees for Photoelectrochemical Dye-Sensitized Solar Cells

2020 ◽  
Vol 10 (6) ◽  
pp. 2149
Author(s):  
Manuel Meneghetti ◽  
Aldo Talon ◽  
Elti Cattaruzza ◽  
Emilio Celotti ◽  
Elisabetta Bellantuono ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Cost Effective ◽  
Simulated Solar Light ◽  
Dye Sensitized ◽  
Different Temperatures ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400–600 °C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.

Effects of different lipid contents on growth of earthworms and the products during vermicomposting

2019 ◽  
Vol 37 (9) ◽  
pp. 934-940 ◽  
Author(s):  
Zexuan Wu ◽  
Bangyi Yin ◽  
Xu Song ◽  
Qi Zhao
Keyword(s):  
Lipid Content ◽  
Low Cost ◽  
Nitrifying Bacteria ◽  
Available Phosphorus ◽  
Negative Effects ◽  
Kitchen Waste ◽  
Lipid Contents ◽  
High Lipid ◽  
Carbon Nitrogen Ratio ◽  
Chemical Characters

In China, the production of kitchen waste was more than 97 million tons per year in 2016. The high lipid content of kitchen waste makes it hard to degrade. Vermicomposting is a kind of low-cost biotechnology through the combination of earthworms and microbes, which could be considered in converting kitchen waste to valuable products. However, the effect of the lipid in kitchen waste on earthworms and composting is not known yet. The objective of this study was to analyze the effects of lipid on vermicomposting and to derive the most suitable lipid content in vermicomposting. In our study, kitchen waste with four different lipid contents was prepared: 0% (A), 5% (B), 10% (C) and 15% (D). The earthworm growth and chemical characters of substrates were measured at the interim (14 days) and the end (28 days) of vermicomposting. Our results showed that the high content of lipid had negative effects on growth of earthworms and products in vermicomposting. The kitchen waste with lower lipid content could be better composted by earthworms. The average body weight of the earthworm increased by 9% in treatment A. Total nitrogen, available phosphorus, available potassium and nitrate nitrogen of treatment A with 0% (measured value: 5%) lipid content were significantly higher than those in other treatments. Meanwhile, treatment A had the lowest carbon/nitrogen ratio which might be due to hindrances in the breathing and activities of earthworms. The high content of lipid makes growth of aerobic bacteria such as nitrifying bacteria difficult.

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