scholarly journals Study of the Potential Uses of Hydrochar from Grape Pomace and Walnut Shells Generated from Hydrothermal Carbonization as an Alternative for the Revalorization of Agri-Waste in Chile

2021 ◽  
Vol 13 (22) ◽  
pp. 12600
Author(s):  
René A. Garrido ◽  
Camila Lagos ◽  
Carolina Luna ◽  
Jaime Sánchez ◽  
Georgina Díaz
Keyword(s):  
Organic Waste ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Grape Pomace ◽  
Walnut Shells ◽  
Decomposition Processes ◽  
Potential Applications ◽  
Potential Benefits ◽  
Reaction Severity ◽  
Significant Attention

A myriad of resources and efforts have been devoted to assessing the possibilities of using locally sourced biomass to produce energy, reduce CO2 emissions, and, in turn, lower dependance on petroleum. Grape pomace (GP) and walnut shells (WS) are organic waste generated in Chile. Within the last decade, the potential benefits and application of biomass have received significant attention, both in terms of producing functionalized carbon materials, and the various potential applications in the field of energy storage and environmental protection. The proposed research motivation is on the development of carbonous materials through thermal decomposition processes. Few researchers have addressed the idea of developing a multipurpose carbonaceous matrix from hydrochar, and there remains a need for an efficient method to obtain hydrochar specially from grape pomace. Hence, the general objective of this research is to study the potential of grape pomace and walnut shells treated with hydrothermal carbonization (HTC) as an alternative low-cost and efficient carbonous matrix. Proximate and elemental analysis was determined to distinguish the nature of the feedstock along with the hydrochar produced. Yield and reaction severity were also studied to study the impacts of temperature and residence time for both feedstocks. Successful results from the proposed work have broad applications for increasing the sustainability biomass applications, contributing to a positive economic impact.

scholarly journals Hydrothermal Carbonization of Organic Waste and Biomass: A Review on Process, Reactor, and Plant Modeling

2020 ◽  
Author(s):  
Giulia Ischia ◽  
Luca Fiori
Keyword(s):  
Organic Waste ◽  
Review Paper ◽  
Recent Literature ◽  
State Of The Art ◽  
Hydrothermal Carbonization ◽  
Residual Biomass ◽  
Current State ◽  
Potential Applications ◽  
Intrinsic Complexity ◽  
Context Models

Abstract Hydrothermal carbonization (HTC) is an emerging path to give a new life to organic waste and residual biomass. Fulfilling the principles of the circular economy, through HTC “unpleasant” organics can be transformed into useful materials and possibly energy carriers. The potential applications of HTC are tremendous and the recent literature is full of investigations. In this context, models capable to predict, simulate and optimize the HTC process, reactors, and plants are engineering tools that can significantly shift HTC research towards innovation by boosting the development of novel enterprises based on HTC technology. This review paper addresses such key-issue: where do we stand regarding the development of these tools? The literature presents many and simplified models to describe the reaction kinetics, some dealing with the process simulation, while few focused on the heart of an HTC system, the reactor. Statistical investigations and some life cycle assessment analyses also appear in the current state of the art. This work examines and analyzes these predicting tools, highlighting their potentialities and limits. Overall, the current models suffer from many aspects, from the lack of data to the intrinsic complexity of HTC reactions and HTC systems. Therefore, the emphasis is given to what is still necessary to make the HTC process duly simulated and therefore implementable on an industrial scale with sufficient predictive margins. Graphic Abstract

Wurtzite CZTS nanocrystals and phase evolution to kesterite thin film for solar energy harvesting

2015 ◽  
Vol 17 (30) ◽  
pp. 19777-19788 ◽  
Author(s):  
Uma V. Ghorpade ◽  
Mahesh P. Suryawanshi ◽  
Seung Wook Shin ◽  
Chang Woo Hong ◽  
Inyoung Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Phase Evolution ◽  
Tin Sulfide ◽  
Copper Zinc Tin Sulfide ◽  
Solar Energy Harvesting ◽  
Potential Applications ◽  
Copper Zinc ◽  
Significant Attention ◽  
Czts Nanocrystals

A quaternary indium- and gallium-free kesterite (KS)-based compound, copper zinc tin sulfide (Cu2ZnSnS4, CZTS), has received significant attention for its potential applications in low cost and sustainable solar cells.

scholarly journals Characterization and comparison of walnut shells-based activated carbons and their adsorptive properties

2020 ◽  
Vol 38 (9-10) ◽  
pp. 450-463
Author(s):  
Xiya Li ◽  
Jieqiong Qiu ◽  
Yiqi Hu ◽  
Xiaoyuan Ren ◽  
Lu He ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Low Cost ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Hydrothermal Carbonization ◽  
Bet Surface Area ◽  
Activation Process ◽  
Walnut Shells ◽  
Adsorption Desorption

The production of low-cost biologically activated carbons (BACs) is urgent need of environmental protection and ecological sustainability. Hence, walnut shells were treated by traditional pyrolysis, direct KOH impregnation and combined activation composed of hydrothermal carbonization and two-step H3PO4- and pyrolysis-activation process to obtain porous carbon with high adsorption capacity. It was found that the best adsorption capacity for iodine and organic dye methylene blue (MB) can be obtained using the KOH impregnation at impregnation ratio of 1:1 or combined activation comprising of 2 h H3PO4 activation and 1 h pyrolysis activation at 1000°C. The produced KOH, H3PO4/pyrolysis activated BACs at the optimum conditions are superior to that of commercial ACs, 9.4 and 1.3 times for MB removal, 4 and 4.5 times for iodine number respectively. Characterization results demonstrated their porous structure with very good textural properties such as high BET surface area (1689.1 m2/g, 1545.3 m2/g) and high total pore volume (0.94 cm3/g, 0.96 cm3/g). The N2 adsorption-desorption isotherm of H3PO4/pyrolysis activated hydrochar suggested the co-existence of micro and meso-pores. Moreover, they are more effective for the removal of Fe(III) and Cr(VI) from aqueous solution than the commercial AC, suggesting a promising application in the field of water treatment.

scholarly journals Cross-Subject EEG-Based Emotion Recognition through Neural Networks with Stratified Normalization

2020 ◽  
Author(s):  
Javier Fdez ◽  
Nicholas Guttenberg ◽  
Olaf Witkowski ◽  
Antoine Pasquali
Keyword(s):  
Neural Networks ◽  
Low Cost ◽  
Model Performance ◽  
Good Deal ◽  
Emotion Classification ◽  
Great Insight ◽  
Potential Applications ◽  
Invasive Method ◽  
Potential Benefits ◽  
Eeg Recordings

Due to a large number of potential applications, a good deal of effort has been recently made towards creating machine learning models that can recognize evoked emotions from one’s physiological recordings. In particular, researchers are investigating the use of EEG as a low-cost, non-invasive method. However, the poor homogeneity of the EEG activity across participants hinders the implementation of any such system by a time-consuming calibration stage. In this study, we introduce a new participant-based feature normalization method, so-called stratified normalization, for training deep neural networks in task of cross-subject emotion classification from EEG signals. The new method is able to subtract inter-participant variability while maintaining the emotion information in the data. We carried out our analysis on the SEED dataset, which contains 62-channel EEG recordings collected from 15 participants while watching film clips. Results demonstrate that networks trained with stratified normalization outperformed standard training with batch normalization significantly. In addition, the highest model performance was achieved when extracting EEG features with the multitaper method, reaching a classification accuracy of 91.6% for two emotion categories (positive and negative) and 79.6% for three (also neutral). This analysis provides us with great insight into the potential benefits that stratified normalization can have when developing any cross-subject model based on EEG.

scholarly journals Cross-Subject EEG-Based Emotion Recognition Through Neural Networks With Stratified Normalization

2021 ◽  
Vol 15 ◽  
Author(s):  
Javier Fdez ◽  
Nicholas Guttenberg ◽  
Olaf Witkowski ◽  
Antoine Pasquali
Keyword(s):  
Neural Networks ◽  
Low Cost ◽  
Model Performance ◽  
Good Deal ◽  
Emotion Classification ◽  
Great Insight ◽  
Potential Applications ◽  
Invasive Method ◽  
Potential Benefits ◽  
Eeg Recordings

Due to a large number of potential applications, a good deal of effort has been recently made toward creating machine learning models that can recognize evoked emotions from one's physiological recordings. In particular, researchers are investigating the use of EEG as a low-cost, non-invasive method. However, the poor homogeneity of the EEG activity across participants hinders the implementation of such a system by a time-consuming calibration stage. In this study, we introduce a new participant-based feature normalization method, named stratified normalization, for training deep neural networks in the task of cross-subject emotion classification from EEG signals. The new method is able to subtract inter-participant variability while maintaining the emotion information in the data. We carried out our analysis on the SEED dataset, which contains 62-channel EEG recordings collected from 15 participants watching film clips. Results demonstrate that networks trained with stratified normalization significantly outperformed standard training with batch normalization. In addition, the highest model performance was achieved when extracting EEG features with the multitaper method, reaching a classification accuracy of 91.6% for two emotion categories (positive and negative) and 79.6% for three (also neutral). This analysis provides us with great insight into the potential benefits that stratified normalization can have when developing any cross-subject model based on EEG.

Removal of nutrients from Organic Liquid Agricultural Waste using filamentous algae.

2020 ◽  
Author(s):  
Gonzalo Flores-Morales ◽  
Mónica Díaz ◽  
Patricia Arancibia-Avila ◽  
Michelle Muñoz-Carrasco ◽  
Pamela Jara-Zapata ◽  
...  
Keyword(s):  
Organic Waste ◽  
Low Cost ◽  
Organic Liquid ◽  
Agricultural Waste ◽  
Filamentous Algae ◽  
Tertiary Treatment ◽  
Nutrient Reduction ◽  
Algae Removal ◽  
Algae Growth ◽  
Waste Effluents

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

A High-Performance Free-Standing Zn Anode for Flexible Zinc-Ion Batteries

Nanoscale ◽  
2021 ◽  
Author(s):  
Chenxi Gao ◽  
Jiawei Wang ◽  
Yuan Huang ◽  
Zixuan Li ◽  
Jiyan Zhang ◽  
...  
Keyword(s):  
Energy Density ◽  
High Performance ◽  
Low Cost ◽  
High Energy ◽  
Zinc Ion ◽  
High Energy Density ◽  
Free Standing ◽  
Energy Device ◽  
Zn Anode ◽  
Significant Attention

Zinc-ion batteries (ZIBs) have attracted significant attention owing to their high safety, high energy density, and low cost. ZIBs have been studied as a potential energy device for portable and...

scholarly journals Hot Pressurized Liquid Extraction of Polyphenols from the Skin and Seeds of Vitis vinifera L. cv. Negra Criolla Pomace a Peruvian Native Pisco Industry Waste

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 866
Author(s):  
Erik E. Allcca-Alca ◽  
Nilton C. León-Calvo ◽  
Olivia M. Luque-Vilca ◽  
Maximiliano Martínez-Cifuentes ◽  
José Ricardo Pérez-Correa ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Ethanol Concentration ◽  
Liquid Extraction ◽  
Grape Pomace ◽  
Pressurized Liquid Extraction ◽  
Vitis Vinifera L ◽  
Solvent Mixtures ◽  
Total Polyphenol ◽  
Industry Waste ◽  
Potential Applications

The pisco industry in Peru generates large amounts of grape pomace, which is a natural source of bioactive compounds with potential nutraceutical applications. Hot pressurized liquid extraction (HPLE) with water-ethanol solvent mixtures (20–60%) at high temperatures (100–160 °C) was applied to recover polyphenols from the skin and seeds of a Peruvian pisco-industry grape-pomace waste. At the same HPLE conditions (60% ethanol, 160 °C), the seed fraction extracts contained ~6 times more total polyphenol and presented ~5 times more antioxidant activity than the extract from the skin fraction. The lowest ethanol concentration (20%) and the highest temperature (160 °C) achieved the highest recovery of flavanols with 163.61 µg/g dw from seeds and 10.37 µg/g dw from skins. The recovery of phenolic acids was maximized at the highest ethanol concentration and temperature with 45.34 µg/g dw from seeds and 6.93 µg/g dw from skins. Flavonols were only recovered from the skin, maximized (17.53 µg/g dw) at 20% of ethanol and the highest temperature. The recovery of specific polyphenols is maximized at specific extraction conditions. These conditions are the same for seed and skin extractions. This alternative method can be used in other agroindustrial wastes in order to recover bioactive compounds with potential applications in the pharmaceutical and food industry.

scholarly journals Visualization of Surface Acoustic Waves in Thin Liquid Films

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
R. W. Rambach ◽  
J. Taiber ◽  
C. M. L. Scheck ◽  
C. Meyer ◽  
J. Reboud ◽  
...  
Keyword(s):  
Liquid Film ◽  
Acoustic Waves ◽  
Low Cost ◽  
Thin Liquid Film ◽  
Surface Acoustic Waves ◽  
Liquid Films ◽  
Theoretical Description ◽  
Propagation Path ◽  
Microfluidic Channels ◽  
Potential Applications

Abstract We demonstrate that the propagation path of a surface acoustic wave (SAW), excited with an interdigitated transducer (IDT), can be visualized using a thin liquid film dispensed onto a lithium niobate (LiNbO3) substrate. The practical advantages of this visualization method are its rapid and simple implementation, with many potential applications including in characterising acoustic pumping within microfluidic channels. It also enables low-cost characterisation of IDT designs thereby allowing the determination of anisotropy and orientation of the piezoelectric substrate without the requirement for sophisticated and expensive equipment. Here, we show that the optical visibility of the sound path critically depends on the physical properties of the liquid film and identify heptane and methanol as most contrast rich solvents for visualization of SAW. We also provide a detailed theoretical description of this effect.

scholarly journals Recent Findings in Azaphilone Pigments

2021 ◽  
Vol 7 (7) ◽  
pp. 541
Author(s):  
Lúcia P. S. Pimenta ◽  
Dhionne C. Gomes ◽  
Patrícia G. Cardoso ◽  
Jacqueline A. Takahashi
Keyword(s):  
Water Solubility ◽  
Biological Activities ◽  
Low Cost ◽  
Scale Up ◽  
Structural Diversity ◽  
Downstream Processing ◽  
Global Market ◽  
Yield Improvement ◽  
Potential Applications ◽  
New Compounds

Filamentous fungi are known to biosynthesize an extraordinary range of azaphilones pigments with structural diversity and advantages over vegetal-derived colored natural products such agile and simple cultivation in the lab, acceptance of low-cost substrates, speed yield improvement, and ease of downstream processing. Modern genetic engineering allows industrial production, providing pigments with higher thermostability, water-solubility, and promising bioactivities combined with ecological functions. This review, covering the literature from 2020 onwards, focuses on the state-of-the-art of azaphilone dyes, the global market scenario, new compounds isolated in the period with respective biological activities, and biosynthetic pathways. Furthermore, we discussed the innovations of azaphilone cultivation and extraction techniques, as well as in yield improvement and scale-up. Potential applications in the food, cosmetic, pharmaceutical, and textile industries were also explored.

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