Microalgal Biomass Generation via Electroflotation: A Cost-Effective Dewatering Technology

Microalgae are an excellent source of bioactive compounds for the production of a wide range of vital consumer products in the biofuel, pharmaceutical, food, cosmetics, and agricultural industries, in addition to huge upstream benefits relating to carbon dioxide biosequestration and wastewater treatment. However, energy-efficient, cost-effective, and scalable microalgal technologies for commercial-scale applications are limited, and this has significantly impacted the full-scale implementation of microalgal biosystems for bioproduct development, phycoremediation, and biorefinery applications. Microalgae culture dewatering continues to be a major challenge to large-scale biomass generation, and this is primarily due to the low cell densities of microalgal cultures and the small hydrodynamic size of microalgal cells. With such biophysical characteristics, energy-intensive solid–liquid separation processes such as centrifugation and filtration are generally used for continuous generation of biomass in large-scale settings, making dewatering a major contributor to the microalgae bioprocess economics. This article analyzes the potential of electroflotation as a cost-effective dewatering process that can be integrated into microalgae bioprocesses for continuous biomass production. Electroflotation hinges on the generation of fine bubbles at the surface of an electrode system to entrain microalgal particulates to the surface. A modification of electroflotation, which combines electrocoagulation to catalyze the coalescence of microalgae cells before gaseous entrainment, is also discussed. A technoeconomic appraisal of the prospects of electroflotation compared with other dewatering technologies is presented.

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A Computational Survey of Semiconductors for Power Electronics

10.26434/chemrxiv.8126879 ◽

2019 ◽

Author(s):

Prashun Gorai ◽

Robert McKinney ◽

Nancy Haegel ◽

Andriy Zakutayev ◽

Vladan Stevanovic

Keyword(s):

Thermal Conductivity ◽

Power Electronics ◽

Figure Of Merit ◽

Large Scale ◽

Lattice Thermal Conductivity ◽

Consumer Products ◽

Breakdown Field ◽

Experimental Investigations ◽

Wide Range ◽

Screening Parameter

Power electronics (PE) are used to control and convert electrical energy in a wide range of applications from consumer products to large-scale industrial equipment. While Si-based power devices account for the vast majority of the market, wide band gap semiconductors such as SiC, GaN, and Ga2O3 are starting to gain ground. However, these emerging materials face challenges due to either non-negligible defect densities, or high synthesis and processing costs, or poor thermal properties. Here, we report on a broad computational survey aimed to identify promising materials for future power electronic devices beyond SiC, GaN, and Ga2O3. We consider 863 oxides, sulfides, nitrides, carbides, silicides, and borides that are reported in the crystallographic database and exhibit finite calculated band gaps. We utilize ab initio methods in conjunction with models for intrinsic carrier mobility, and critical breakdown field to compute the widely used Baliga figure of merit. We also compute the lattice thermal conductivity as a screening parameter. In addition to correctly identifying known PE materials, our survey has revealed a number of promising candidates exhibiting the desirable combination of high figure of merit and high lattice thermal conductivity, which we propose for further experimental investigations.

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Enterprise Crowdsourcing Platform to Improve HR Workflow

Management of the personnel and intellectual resources in Russia ◽

10.12737/2305-7807-2020-5-8 ◽

2020 ◽

Vol 9 (5) ◽

pp. 5-8 ◽

Cited By ~ 1

Author(s):

G. Zuev

Keyword(s):

Large Scale ◽

Best Practice ◽

Cost Effective ◽

Hr Management ◽

Practical Project ◽

Effective Manner ◽

Wide Range ◽

Hr Managers ◽

Short Time ◽

Small Parts

Crowdsourcing technologies may solve a wide range of business issues: improve efficiency of HR management, increase customer loyalty and maximize economic efficiency of whole enterprise. The recent years best practice has shown how crowdsourcing is gaining particular relevance of human resource management, allowing HR managers to resolve organization relevant problems in quick and cost-effective manner. Important advantage of crowdsourcing сomes from his main ability: decomposition of tasks into small parts and the ability to perform it’s remotely, via Internet. Thanks to this, not only large corporations, but also small and medium-sized businesses can execute a large-scale projects in a short time. This article discusses the main approaches and principles of practical project management via crowdsourcing platforms, using as the example “Beorg Smart Vision” solution.

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Impresión 3D como Herramienta Didáctica para la Enseñanza de Algunos Conceptos de Ingeniería y Diseño

Ingeniería ◽

10.14483/23448393.12248 ◽

2018 ◽

Vol 23 (1) ◽

pp. 70 ◽

Cited By ~ 1

Author(s):

Edwin Blasnilo Rua Ramirez ◽

Fernando Jimenez Diaz ◽

German Andres Gutierrez Arias ◽

Nelson Iván Villamizar

Keyword(s):

Teaching And Learning ◽

Mechanical Engineering ◽

Large Scale ◽

Low Cost ◽

Cost Effective ◽

3D Printer ◽

Course Grades ◽

Wide Range ◽

Technical Specifications ◽

Future Work

Context: 3D printing can be used for a wide range of tasks such as the design and testing of prototypes and finished products in a shorter time. In mechanical engineering, prototype designs are continuously generated in academic class activities and final coursework projects by students and teachers. However, students show limitations while understanding the abstract concepts represented with such designs.Method: Firstly, a large scale 3D printer with improved technical specifications compared to traditional market options and similar price, was fabricated. By means of free software and hardware tools and easy-to-obtain alternative manufacturing materials, it was possible to decrease its manufacturing and operating costs. Then a set of study cases utilising the 3D printer in three different subject classes were designed and tested with two cohorts of students of Mechanical Engineering programme.Results: It was feasible to fabricate a cost-effective and practical 3D printer for constructing prototypes and pieces that benefit teaching and learning concepts in engineering and design areas. The experiments carried out in three subjects of engineering courses with second-year students, showed a similar trend of improving the average course grades, as it was observed in two cohorts in different terms.Conclusions: This type of low cost 3D printer obtained academic advantages as a didactic tool for the learning process in engineering and design subjects. Future work will consider applying this tool to other courses and subjects to further evaluate its convenience and effectivity.

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Prospects of Microalgae for Biomaterial Production and Environmental Applications at Biorefineries

Sustainability ◽

10.3390/su13063063 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3063

Author(s):

Lourdes Orejuela-Escobar ◽

Arleth Gualle ◽

Valeria Ochoa-Herrera ◽

George P. Philippidis

Keyword(s):

Heavy Metal ◽

Value Added ◽

Chemical Compounds ◽

Environmental Applications ◽

Current Status ◽

Microalgal Biomass ◽

Comprehensive Review ◽

Wide Range ◽

Agricultural Industries ◽

Adsorptive Properties

Microalgae are increasingly viewed as renewable biological resources for a wide range of chemical compounds that can be used as or transformed into biomaterials through biorefining to foster the bioeconomy of the future. Besides the well-established biofuel potential of microalgae, key microalgal bioactive compounds, such as lipids, proteins, polysaccharides, pigments, vitamins, and polyphenols, possess a wide range of biomedical and nutritional attributes. Hence, microalgae can find value-added applications in the nutraceutical, pharmaceutical, cosmetics, personal care, animal food, and agricultural industries. Microalgal biomass can be processed into biomaterials for use in dyes, paints, bioplastics, biopolymers, and nanoparticles, or as hydrochar and biochar in solid fuel cells and soil amendments. Equally important is the use of microalgae in environmental applications, where they can serve in heavy metal bioremediation, wastewater treatment, and carbon sequestration thanks to their nutrient uptake and adsorptive properties. The present article provides a comprehensive review of microalgae specifically focused on biomaterial production and environmental applications in an effort to assess their current status and spur further deployment into the commercial arena.

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Growth Kinetic Model for Microalgae Cultivation in Open Raceway Ponds: A System Dynamics Tool

Environmental and Climate Technologies ◽

10.2478/rtuect-2021-0100 ◽

2021 ◽

Vol 25 (1) ◽

pp. 1317-1336

Author(s):

Francesco Romagnoli ◽

Anton Rayan Priyasad Perera Weerasuriya-Arachchige ◽

Riccardo Paoli ◽

Maksims Feofilovs ◽

Baiba Ievina

Keyword(s):

System Dynamics ◽

Large Scale ◽

Industrial Sector ◽

Microalgae Cultivation ◽

Algae Biomass ◽

Open Raceway Pond ◽

Raceway Pond ◽

Microalgae Culture ◽

Wide Range ◽

Raceway Ponds

Abstract Microalgae culture has the potential to play an essential role in the application of circular economy principles. Microalgae cultivation allows utilizing industrial side-waste streams while ensuring biomass for a wide range of applications in the industrial sector. Specifically, cultivation in outdoor open raceway ponds are a preferred solution due to low costs, ease of operation and large-scale application. However, the economic viability of the cultivation system largely depends on the amount of biomass produced, the technology implemented and the microalgae species and strains. For this purpose, screening of numerous physical, chemical, and environmental factors affecting microalgae growth must be performed before implementing large-scale microalgae cultivation systems. Furthermore, to obtain the highest biomass yield, the design and operating parameters for open raceway pond cultivation must be investigated in depth. Therefore, this study proposes a kinetic growth model for microalgae cultivation in open raceway ponds based on System Dynamics modelling approach. The proposed model aims at overcoming the major problems of existing growth evaluation tools such as separate assessment of different parameters, high complexity, time consumption and other challenges. The proposed system dynamics model proves to be a simple yet powerful tool for modelling the behaviour of algae biomass in an open raceway pond.

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Airborne environmental DNA for terrestrial vertebrate community monitoring

10.1101/2021.07.16.452634 ◽

2021 ◽

Author(s):

Christina Lynggaard ◽

Mads Frost Bertelsen ◽

Casper V. Jensen ◽

Matthew S. Johnson ◽

Tobias Guldberg Froslev ◽

...

Keyword(s):

Large Scale ◽

Environmental Dna ◽

Cost Effective ◽

Monitoring Methods ◽

Natural Ecosystems ◽

Terrestrial Vertebrate ◽

Detection Failure ◽

Routine Monitoring ◽

Community Monitoring ◽

Wide Range

Assessing and studying the distribution, ecology, diversity and movements of species is key in understanding environmental and anthropogenic effects on natural ecosystems. Although environmental DNA is rapidly becoming the tool of choice to assess biodiversity there are few eDNA sample types that effectively capture terrestrial vertebrate diversity and those that do can be laborious to collect, require special permits and contain PCR inhibitory substances, which can lead to detection failure. Thus there is an urgent need for novel environmental DNA approaches for efficient and cost-effective large-scale routine monitoring of terrestrial vertebrate diversity. Here we show that DNA metabarcoding of airborne environmental DNA filtered from air can be used to detect a wide range of local vertebrate taxa. We filtered air at three localities in Copenhagen Zoo, detecting mammal, bird, amphibian and reptile species present in the zoo or its immediate surroundings. Our study demonstrates that airDNA has the capacity to complement and extend existing terrestrial vertebrate monitoring methods and could form the cornerstone of programs to assess and monitor terrestrial communities, for example in future global next generation biomonitoring frameworks.

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Inference of Chromosome-Length Haplotypes Using Genomic Data of Three or a Few More Single Gametes

Molecular Biology and Evolution ◽

10.1093/molbev/msaa176 ◽

2020 ◽

Vol 37 (12) ◽

pp. 3684-3698 ◽

Cited By ~ 1

Author(s):

Ruidong Li ◽

Han Qu ◽

Jinfeng Chen ◽

Shibo Wang ◽

John M Chater ◽

...

Keyword(s):

Large Scale ◽

Low Cost ◽

Genomic Data ◽

Cost Effective ◽

R Package ◽

Chromosome Length ◽

Sequencing Data ◽

Experimental Phasing ◽

Wide Range ◽

Haplotype Data

Abstract Compared with genomic data of individual markers, haplotype data provide higher resolution for DNA variants, advancing our knowledge in genetics and evolution. Although many computational and experimental phasing methods have been developed for analyzing diploid genomes, it remains challenging to reconstruct chromosome-scale haplotypes at low cost, which constrains the utility of this valuable genetic resource. Gamete cells, the natural packaging of haploid complements, are ideal materials for phasing entire chromosomes because the majority of the haplotypic allele combinations has been preserved. Therefore, compared with the current diploid-based phasing methods, using haploid genomic data of single gametes may substantially reduce the complexity in inferring the donor’s chromosomal haplotypes. In this study, we developed the first easy-to-use R package, Hapi, for inferring chromosome-length haplotypes of individual diploid genomes with only a few gametes. Hapi outperformed other phasing methods when analyzing both simulated and real single gamete cell sequencing data sets. The results also suggested that chromosome-scale haplotypes may be inferred by using as few as three gametes, which has pushed the boundary to its possible limit. The single gamete cell sequencing technology allied with the cost-effective Hapi method will make large-scale haplotype-based genetic studies feasible and affordable, promoting the use of haplotype data in a wide range of research.

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A Computational Survey of Semiconductors for Power Electronics

10.26434/chemrxiv.8126879.v1 ◽

2019 ◽

Author(s):

Prashun Gorai ◽

Robert McKinney ◽

Nancy Haegel ◽

Andriy Zakutayev ◽

Vladan Stevanovic

Keyword(s):

Thermal Conductivity ◽

Power Electronics ◽

Figure Of Merit ◽

Large Scale ◽

Lattice Thermal Conductivity ◽

Consumer Products ◽

Breakdown Field ◽

Experimental Investigations ◽

Wide Range ◽

Screening Parameter

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Large-Scale Retrieval of Coloured Dissolved Organic Matter in Northern Lakes Using Sentinel-2 Data

Remote Sensing ◽

10.3390/rs12010157 ◽

2020 ◽

Vol 12 (1) ◽

pp. 157 ◽

Cited By ~ 2

Author(s):

Enass Said. Al-Kharusi ◽

David E. Tenenbaum ◽

Abdulhakim M. Abdi ◽

Tiit Kutser ◽

Jan Karlsson ◽

...

Keyword(s):

Water Quality ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Large Scale ◽

Cost Effective ◽

Water Quality Parameter ◽

Power Relationship ◽

Wide Range ◽

Band Ratios ◽

Sentinel 2A

Owing to the significant societal value of inland water resources, there is a need for cost-effective monitoring of water quality on large scales. We tested the suitability of the recently launched Sentinel-2A to monitor a key water quality parameter, coloured dissolved organic matter (CDOM), in various types of lakes in northern Sweden. Values of a(420)CDOM (CDOM absorption at 420 nm wavelength) were obtained by analyzing water samples from 46 lakes in five districts across Sweden within an area of approximately 800 km2. We evaluated the relationships between a(420)CDOM and band ratios derived from Sentinel-2A Level-1C and Level-2A products. The band ratios B2/B3 (460 nm/560 nm) and B3/B5 (560 nm/705 nm) showed poor relationships with a(420)CDOM in Level-1C and 2A data both before and after the removal of outliers. However, there was a slightly stronger power relationship between the atmospherically-corrected B3/B4 ratio and a(420)CDOM (R2 = 0.28, n = 46), and this relationship was further improved (R2 = 0.65, n = 41) by removing observations affected by light haze and cirrus clouds. This study covered a wide range of lakes in different landscape settings and demonstrates the broad applicability of a(420)CDOM retrieval algorithms based on the B3/B4 ratio derived from Sentinel-2A.

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Harvesting of Microalgae by Flocculation

Fermentation ◽

10.3390/fermentation4040093 ◽

2018 ◽

Vol 4 (4) ◽

pp. 93 ◽

Cited By ~ 30

Author(s):

Irena Branyikova ◽

Gita Prochazkova ◽

Tomas Potocar ◽

Zuzana Jezkova ◽

Tomas Branyik

Keyword(s):

Large Scale ◽

Production Systems ◽

Cost Effective ◽

Scale Production ◽

Surface Charges ◽

Microalgal Biomass ◽

Chemical Surface ◽

Large Scale Production ◽

Negative Surface ◽

Production Technologies

Due to increasing demands for microalgal biomass and products originating from microalgae, large-scale production systems are necessary. However, current microalgal production technologies are not cost-effective and are hindered by various bottlenecks, one of which is the harvesting of microalgal biomass. Cell separation is difficult because of the low sedimentation velocity of microalgae, their colloidal character with repelling negative surface charges, and low biomass concentrations in culture broths; therefore, large volumes need to be processed in order to concentrate the cells. Flocculation is considered to be one of the most suitable methods for harvesting microalgal biomass. This article provides an overview of flocculation methods suitable for microalgal harvesting, their mechanisms, advantages and drawbacks. Special attention is paid to the role of surface charge in the mechanism of flocculation. The novelty of the review lies in the interconnection between the context of technological applications and physico-chemical surface phenomena.

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