scholarly journals Environmental aspects of insect mass production

2021 ◽  
pp. 1-20
Author(s):  
S. Smetana ◽  
R. Spykman ◽  
V. Heinz
Keyword(s):  
Mass Production ◽  
Sustainability Assessment ◽  
Value Chains ◽  
Environmental Aspects ◽  
Table Analysis ◽  
Modular Analysis ◽  
Impact Assessment Methodology ◽  
Species Production ◽  
Comparability Of Results

Mass production of insects is calling for environmentally optimised and economically efficient insect value chains. It is a complex task considering a great variety in insect species, production scales, feed formulations, etc. Taking a challenge of environmental impact clarification, a few studies highlight on life cycle assessment (LCA) of insect production. The current study is aimed to systemise 24 selected previous studies to establish a modular framework for the determination of contribution of sustainability assessment factors of insect production chains. Reviewing published studies according to the elements of LCA, the study identified a feasible approach for the modelling of insect production chains, which can be used for the facilitation of comparability of further LCA studies. The approach is based on a modular analysis of insect production through a graphical mapping of value chains (allowed identification of precise system boundaries) supplemented with table analysis considering scale of production, reference (functional) unit, impact assessment methodology and type of LCA. Such an approach allows for consistency in LCA setting and further comparability of results.

scholarly journals Framework for Life Cycle Sustainability Assessment of Additive Manufacturing

2020 ◽  
Vol 12 (3) ◽  
pp. 929 ◽  
Author(s):  
Ribeiro ◽  
Matos ◽  
Jacinto ◽  
Salman ◽  
Cardeal ◽  
...  
Keyword(s):  
Life Cycle ◽  
Additive Manufacturing ◽  
Sustainability Assessment ◽  
Value Chains ◽  
Illustrative Case ◽  
Bottom Line ◽  
Disruptive Technologies ◽  
The People ◽  
Specific Dimension ◽  
Traditional Manufacturing

Additive manufacturing (AM) is a group of technologies that create objects by adding material layer upon layer, in precise geometric shapes. They are amongst the most disruptive technologies nowadays, potentially changing value chains from the design process to the end-of-life, providing significant advantages over traditional manufacturing processes in terms of flexibility in design and production and waste minimization. Nevertheless, sustainability assessment should also be included in the research agenda as these technologies affect the People, the Planet and the Profit: the three-bottom line (3BL) assessment framework. Moreover, AM sustainability depends on each product and context that strengthens the need for its assessment through the 3BL framework. This paper explores the literature on AM sustainability, and the results are mapped in a framework aiming to support comprehensive assessments of the AM impacts in the 3BL dimensions by companies and researchers. To sustain the coherence of boundaries, three life cycle methods are proposed, each one for a specific dimension of the 3BL analysis, and two illustrative case studies are shown to exemplify the model.

Geometric Calculations of the Chamfered Tip and the Protuberance Undercut of a Tooth Profile

2011 ◽  
Author(s):  
Milos Nemcek ◽  
Zdenek Dejl
Keyword(s):  
Mass Production ◽  
Gear Tooth ◽  
Tooth Profile ◽  
Measuring Device ◽  
Car Industry ◽  
Industry Standard ◽  
Tooth Flank ◽  
Computing Method ◽  
Circle Diameter

Nowadays special modified tools are mostly used for rough or semi-finishing milling in the mass production of ground or shaved gears today. These modifications ensure the desired chamfer at the head or the undercut at the bottom of the gear tooth. Diameters of the beginning and the end of the operational involute (exact knowledge of them is necessary for the calculation of important meshing parameters) are found by using several techniques. The first one is the simulation of the generating action of a hob tooth using suitable graphic software with the subsequent measuring of these diameters from the envelope of hob tooth positions which was created. The second one is measuring directly on the gear manufactured using a measuring device. These simulations or measuring are often not performed and the tool with recommended parameters of the protuberance or the ramp is simply chosen by an educated guess [1]. But it is not an acceptable technique in a mass production (car industry). Standard DIN 3960 [2] gives a certain manual for the determination of these diameters. It suggests the iterative method for the calculation of the chamfer beginning circle diameter but without a reliable guideline. And as regards the protuberance, it refers to the correct calculation only in theory. This paper deals with the computing method to determine diameters of the beginning and the end of the function part of a tooth flank involute. It is designed for a specified tool with modifications for creating the chamfer or the protuberance undercut. The paper also takes into account the necessary shaving (grinding) stock or the backlash. Furthermore it refers to possible problems when the basic profile of the generating tool with the protuberance is designed from the basic rack tooth profile.

scholarly journals Ghrelin Alleviates Endoplasmic Reticulum Stress in MC3T3E1 Cells by Inhibiting AMPK Phosphorylation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xue Lv ◽  
Qianping Zhang ◽  
Bingfei Cheng ◽  
Ying Xin ◽  
Jun Wang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Energy Homeostasis ◽  
Marker Genes ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Expression Of Genes ◽  
Species Production ◽  
Related Proteins

Ghrelin is a gastric endocrine peptide that has been found to be involved in the process of energy homeostasis and bone physiology in recent years. To explore the effects of ghrelin on endoplasmic reticulum stress (ERS) in MC3T3E1 cells and its possible mechanism, an ERS model was induced by tunicamycin (TM) in the osteoblast line MC3T3E1. TM at 1.5 μg/mL was selected as the experimental concentration found by CCK8 assay. Through the determination of apoptosis, reactive oxygen species production, and endoplasmic reticulum stress-related gene expression, we found that ERS induced by TM can be relieved by ghrelin in a concentration-dependent manner ( P < 0.001 ). Compared with the TM group, ghrelin reduced the expression of ERS-related marker genes induced by TM. Compared with the GSK621 + TM group without ghrelin pretreatment, the mRNA expression of genes in the ghrelin pretreatment group decreased significantly ( P < 0.001 ). The results of protein analysis showed that the levels of BIP, p-AMPK, and cleaved-caspase3 in the TM group increased significantly, while the levels decreased after ghrelin pretreatment. In group GSK621 + TM compared with group GSK621 + ghrelin+TM, ghrelin pretreatment significantly reduced the level of p-AMPK, which is consistent with the trend of the ERS-related proteins BIP and cleaved-caspase3. In conclusion, ghrelin alleviates the ERS induced by TM in a concentration-dependent manner and may or at least partly alleviate the apoptosis induced by ERS in MC3T3E1 cells by inhibiting the phosphorylation of AMPK.

Verification of Numerical Roll Forming Loads with the Aid of Measurement Equipment

2014 ◽  
Vol 939 ◽  
pp. 373-380 ◽  
Author(s):  
Peter Groche ◽  
Christian Mueller ◽  
Lars Baeumer
Keyword(s):  
Numerical Model ◽  
Process Design ◽  
Mass Production ◽  
Roll Forming ◽  
Measurement Equipment ◽  
Forming Process ◽  
Forming Simulation ◽  
Roll Forming Process

Roll forming is an important forming process for profile manufacturing in mass production. The design of the process has an important influence on the quality of the products. Therefore, the knowledge of the occurring loads during the roll forming process, e.g. forces and pressures, is essential for the process design. However, the experimental determination of the occurring contact normal pressures in roll forming processes poses a challenge. Finite element simulations offer the potential to approximate contact normal loads and thus, enable a better process design. Nevertheless, due to simplifications of the numerical model, a realistic and reliable output of loads in roll forming is not possible. An enhanced numerical model could provide more valuable information. This paper will demonstrate the reproduction of realistic contact normal pressures and load forces in a roll forming simulation. To verify the numerical values, they will be compared to data gained by experiments.

Mapping fisheries value chains to facilitate their sustainability assessment: Case studies in The Gambia and Mali

Marine Policy ◽  
2022 ◽  
Vol 135 ◽  
pp. 104854
Author(s):  
Ivonne Acosta-Alba ◽  
Gian Nicolay ◽  
Adama Mbaye ◽  
Moustapha Dème ◽  
Ludovic Andres ◽  
...  
Keyword(s):  
Case Studies ◽  
Sustainability Assessment ◽  
The Gambia ◽  
Value Chains
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