scholarly journals A Case Study about Biomass Torrefaction on an Industrial Scale: Solutions to Problems Related to Self-Heating, Difficulties in Pelletizing, and Excessive Wear of Production Equipment

2020 ◽  
Vol 10 (7) ◽  
pp. 2546 ◽  
Author(s):  
Leonel J.R. Nunes
Keyword(s):  
Scale Up ◽  
Pilot Scale ◽  
Production Equipment ◽  
Continuous Operation ◽  
Production Costs ◽  
Thermochemical Conversion ◽  
Full Potential ◽  
Conversion Technologies ◽  
Work Done

The search for different forms of biomass that can be used as an alternative to those more traditional ones has faced numerous difficulties, namely those related to disadvantages that the majority of residual forms present. However, these residual forms of biomass also have advantages, namely the fact that, by being outside the usual biomass supply chains for energy, they are usually much cheaper, and therefore contribute to a significant reduction in production costs. To improve the less-favorable properties of these biomasses, thermochemical conversion technologies, namely torrefaction, are presented as a way to improve the combustibility of these materials. However, it is a technology that has not yet demonstrated its full potential, mainly due to difficulties in the process of scale-up and process control. In this article it is intended to present the experience obtained over 5 years in the operation of a biomass torrefaction plant with an industrial pilot scale, where all the difficulties encountered and how they were corrected are presented, until it became a fully operational plant. This article, in which a real case study is analyzed, presents in a descriptive way all the work done during the time from when the plant started up and during the commissioning period until the state of continuous operation had been reached.

scholarly journals Positive Youth Development in Senegal: A Case Study of 4-H Senegal

2021 ◽  
Vol 16 (2-3) ◽  
pp. 344-362
Author(s):  
Thomas Archibald ◽  
Bineta K. Guisse ◽  
Amadou Ndiaye ◽  
Fatimata Kane ◽  
Fatou Diouf ◽  
...  
Keyword(s):  
Youth Development ◽  
Positive Youth Development ◽  
Culturally Responsive ◽  
Scale Up ◽  
Cross Cultural ◽  
Full Potential ◽  
Study Results ◽  
Conceptual Background ◽  
African Youth

African youth face great challenges and great opportunities. Positive youth development (PYD) programs have the potential to support youth in Africa to reach their full potential. Yet PYD approaches must be tailored if they are to be contextually and culturally responsive and relevant. The purpose of this paper is to provide an evidence-informed description of one such program, the 4-H Senegal PYD program. We first provide a conceptual background for the program, informed especially by the literature on global and cross-cultural PYD. We then share empirical results of a qualitative case study focused on the establishment, scale-up, and institutionalization of the 4-H Senegal program. Our case study results elucidate culturally responsive PYD program adaptations that corroborate conceptual framings of cross-cultural PYD work while also pointing the way towards promising practice recommendations. We hope this conceptual and empirical summary of the 4-H Senegal program can contribute to the field by informing practice and guiding other innovative efforts to adapt PYD models and approaches across contextual and cultural bounds.

scholarly journals Waste Recovery through Thermochemical Conversion Technologies: A Case Study with Several Portuguese Agroforestry By-Products

2020 ◽  
Vol 2 (3) ◽  
pp. 377-391 ◽  
Author(s):  
Leonel J. R. Nunes ◽  
Liliana M. E. F. Loureiro ◽  
Letícia C. R. Sá ◽  
Hugo F. C. Silva
Keyword(s):  
Agricultural Production ◽  
Thermochemical Conversion ◽  
Olive Pomace ◽  
Fixed Carbon ◽  
Residual Biomass ◽  
Conversion Technologies ◽  
Different Characteristics ◽  
Almond Husk ◽  
By Products

Agroforestry waste stores a considerable amount of energy that can be used. Portugal has great potential to produce bioenergy. The waste generated during agricultural production and forestry operation processes can be used for energy generation, and it can be used either in the form in which it is collected, or it can be processed using thermochemical conversion technologies, such as torrefaction. This work aimed to characterize the properties of a set of residues from agroforestry activities, namely rice husk, almond husk, kiwi pruning, vine pruning, olive pomace, and pine woodchips. To characterize the different materials, both as-collected and after being subjected to a torrefaction process at 300 °C, thermogravimetric analyses were carried out to determine the moisture content, ash content, fixed carbon content, and the content of volatile substances; elementary analyses were performed to determine the levels of carbon, nitrogen, hydrogen, and oxygen, and the high and low heating values were determined. With these assumptions, it was observed that each form of residual biomass had different characteristics, which are important to know when adapting to conversion technology, and they also had different degrees of efficiency, that is, the amount of energy generated and potentially used when analyzing all factors.

First principles calculation of structural, electronic and optical properties of (001) and (110) growth axis (InN)/(GaN)n superlattices

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 7
Author(s):  
B. Bachir Bouiadjra ◽  
N. Mehnane ◽  
N. Oukli
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Scale Up ◽  
Energy Scale ◽  
First Principles Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Growth Axis

Based on the full potential linear muffin-tin orbitals (FPLMTO) calculation within density functional theory, we systematically investigate the electronic and optical properties of (100) and (110)-oriented (InN)/(GaN)n zinc-blende superlattice with one InN monolayer and with different numbers of GaN monolayers. Specifically, the electronic band structure calculations and their related features, like the absorption coefficient and refractive index of these systems are computed over a wide photon energy scale up to 20 eV. The effect of periodicity layer numbers n on the band gaps and the optical activity of (InN)/(GaN)n SLs in the both  growth axis (001) and (110) are examined and compared. Because of prospective optical aspects of (InN)/(GaN)n such as light-emitting applications, this theoretical study can help the experimental measurements.

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

scholarly journals Challenges and Barriers for Net‐Zero/Positive Energy Buildings and Districts—Empirical Evidence from the Smart City Project SPARCS

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 78
Author(s):  
Daria Uspenskaia ◽  
Karl Specht ◽  
Hendrik Kondziella ◽  
Thomas Bruckner
Keyword(s):  
Smart City ◽  
Urban Areas ◽  
Smart Cities ◽  
Scale Up ◽  
Practical Experience ◽  
Positive Energy ◽  
Low Carbon ◽  
Net Zero ◽  
Multidimensional Representation

Without decarbonizing cities energy and climate objectives cannot be achieved as cities account for approximately two thirds of energy consumption and emissions. This goal of decarbonizing cities has to be facilitated by promoting net-zero/positive energy buildings and districts and replicating them, driving cities towards sustainability goals. Many projects in smart cities demonstrate novel and groundbreaking low-carbon solutions in demonstration and lighthouse projects. However, as the historical, geographic, political, social and economic context of urban areas vary greatly, it is not always easy to repeat the solution in another city or even district. It is therefore important to look for the opportunities to scale up or repeat successful pilots. The purpose of this paper is to explore common trends in technologies and replication strategies for positive energy buildings or districts in smart city projects, based on the practical experience from a case study in Leipzig—one of the lighthouse cities in the project SPARCS. One of the key findings the paper has proven is the necessity of a profound replication modelling to deepen the understanding of upscaling processes. Three models analyzed in this article are able to provide a multidimensional representation of the solution to be replicated.

Digital forensics and evolving cyber law: case of BIMSTEC countries

2019 ◽  
Vol 22 (4) ◽  
pp. 744-752
Author(s):  
Sisira Dharmasri Jayasekara ◽  
Iroshini Abeysekara
Keyword(s):  
Information Technology ◽  
Design Methodology ◽  
Digital Forensics ◽  
Content Type ◽  
Global Context ◽  
Study Approach ◽  
Legal Frameworks ◽  
Work Done

Purpose The purpose of this paper is to discuss the role of digital forensics in an evolving environment of cyber laws giving attention to Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) countries, comprising Bangladesh, India, Myanmar, Sri Lanka, Thailand, Nepal and Bhutan, in a dynamic global context. Design/methodology/approach This study uses a case study approach to discuss the digital forensics and cyber laws of BIMSTEC countries. The objective of the study was expected to be achieved by referring to decided cases in different jurisdictions. Cyber laws of BIMSTEC countries were studied for the purpose of this study. Findings The analysis revealed that BIMSTEC countries are required to amend legislation to support the growth of information technology. Most of the legislation are 10-15 years old and have not been amended to resolve issues on cyber jurisdictions. Research limitations/implications This study was limited to the members of the BIMSTEC. Originality/value This paper is an original work done by the authors who have discussed the issues of conducting investigations with respect to digital crimes in a rapidly changing environment of information technology and deficient legal frameworks.

scholarly journals Pilot-Scale Production of Chito-Oligosaccharides Using an Innovative Recombinant Chitosanase Preparation Approach

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 290
Author(s):  
Chih-Yu Cheng ◽  
Chia-Huang Tsai ◽  
Pei-Jyun Liou ◽  
Chi-Hang Wang
Keyword(s):  
Cell Density ◽  
Scale Up ◽  
Cost Effective ◽  
Pilot Scale ◽  
Ionic Concentration ◽  
Dihydrogen Phosphate ◽  
Scale Production ◽  
Sodium Dihydrogen Phosphate ◽  
Selective Precipitation ◽  
Pilot Scale Production

For pilot-scale production of chito-oligosaccharides, it must be cost-effective to prepare designable recombinant chitosanase. Herein, an efficient method for preparing recombinant Bacillus chitosanase from Escherichia coli by elimination of undesirable substances as a precipitate is proposed. After an optimized culture with IPTG (Isopropyl β-d-1-thiogalactopyranoside) induction, the harvested cells were resuspended, disrupted by sonication, divided by selective precipitation, and stored using the same solution conditions. Several factors involved in these procedures, including ion types, ionic concentration, pH, and bacterial cell density, were examined. The optimal conditions were inferred to be pH = 4.5, 300 mM sodium dihydrogen phosphate, and cell density below 1011 cells/mL. Finally, recombinant chitosanase was purified to >70% homogeneity with an activity recovery and enzyme yield of 90% and 106 mg/L, respectively. When 10 L of 5% chitosan was hydrolyzed with 2500 units of chitosanase at ambient temperature for 72 h, hydrolyzed products having molar masses of 833 ± 222 g/mol with multiple degrees of polymerization (chito-dimer to tetramer) were obtained. This work provided an economical and eco-friendly preparation of recombinant chitosanase to scale up the hydrolysis of chitosan towards tailored oligosaccharides in the near future.

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