scholarly journals SIMPLE EVOLUTIONARY STRUCURAL OPTIMIZATION FOR MULTIPLE MATERIALS

2021 ◽  
Vol 2021 (4) ◽  
pp. 4818-4823
Author(s):  
JAROSLAV ROJICEK ◽  
◽  
DAGMAR LICKOVA ◽  
Keyword(s):  
Evolution Rate ◽  
Allowable Stress ◽  
Multiple Materials

An evolutionary procedure for multiple materials is presented. A material is selected due to an allowable stress interval for the material. The presented method includes a mesh-independent filter. The proposed algorithm is applied to three examples with four or five materials. In the presented examples, the effect of an evolution rate, a filter setting, and the number of elements, are shown in a simplified way. It is shown that the final topology of structure meets the stress requirements of the materials.

Composite Solutions for Deck Catamarans

2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Structure ◽  
High Strength ◽  
Total Weight ◽  
External Loading ◽  
Strength Analysis ◽  
Allowable Stress ◽  
The Finite Element Method ◽  
Inland Navigation

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.

Microbial Activity Evolution during the Acclimation of a Mixed Culture to Phenol: Use of CO2 Evolution Rate as Indicator

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2049-2052 ◽  
Author(s):  
G. Buitrón ◽  
A. Koefoed ◽  
B. Capdeville
Keyword(s):  
Microbial Activity ◽  
Control Parameter ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Evolution Rate ◽  
Biodegradation Rate ◽  
Carbon Dioxide Evolution ◽  
Carbon Dioxide Evolution Rate ◽  
Infra Red ◽  
Negative Effect

The microbial activity during the aerobic acclimation of activated sludge to phenol was studied. Carbon dioxide evolution rate (CER), measured in a sequencing batch reactor coupled to an infra-red system, was utilized as the activity control parameter. It was found that CER is representative of the microbial metabolism. Moreover, it was observed that starvation periods during acclimation had a negative effect on biodegradation rate.

scholarly journals Light environment drives evolution of color vision genes in butterflies and moths

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yash Sondhi ◽  
Emily A. Ellis ◽  
Seth M. Bybee ◽  
Jamie C. Theobald ◽  
Akito Y. Kawahara
Keyword(s):  
Amino Acids ◽  
Color Vision ◽  
Light Availability ◽  
High Light ◽  
Light Environment ◽  
Evolution Rate ◽  
Animal Evolution ◽  
Light Sensing ◽  
Rates Of Evolution ◽  
Gains And Losses

AbstractOpsins, combined with a chromophore, are the primary light-sensing molecules in animals and are crucial for color vision. Throughout animal evolution, duplications and losses of opsin proteins are common, but it is unclear what is driving these gains and losses. Light availability is implicated, and dim environments are often associated with low opsin diversity and loss. Correlations between high opsin diversity and bright environments, however, are tenuous. To test if increased light availability is associated with opsin diversification, we examined diel niche and identified opsins using transcriptomes and genomes of 175 butterflies and moths (Lepidoptera). We found 14 independent opsin duplications associated with bright environments. Estimating their rates of evolution revealed that opsins from diurnal taxa evolve faster—at least 13 amino acids were identified with higher dN/dS rates, with a subset close enough to the chromophore to tune the opsin. These results demonstrate that high light availability increases opsin diversity and evolution rate in Lepidoptera.

scholarly journals Semi-Automated Determination of Heavy Metals in Autopsy Tissue Using Robot-Assisted Sample Preparation and ICP-MS

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3820
Author(s):  
Heidi Fleischer ◽  
Christoph Lutter ◽  
Andreas Büttner ◽  
Wolfram Mittelmeier ◽  
Kerstin Thurow
Keyword(s):  
Heavy Metals ◽  
Human Tissue ◽  
Cranial Nerves ◽  
Systemic Exposure ◽  
Body Fluids ◽  
Automation System ◽  
Robot Assisted ◽  
Icp Ms ◽  
Multiple Materials

The endoprosthetic care of hip and knee joints introduces multiple materials into the human body. Metal containing implant surfaces release degradation products such as particulate wear and corrosion debris, metal-protein complexes, free metallic ions, inorganic metal salts or oxides. Depending on the material composition of the prostheses, a systemic exposure occurs and may result in increasing metal concentrations in body fluids and tissues especially in the case of malfunctions of the arthroplasty components. High concentrations of Cr, Co, Ni, Ti and Al affect multiple organs such as thyroid, heart, lung and cranial nerves and may lead to metallosis, intoxications, poly-neuropathy, retinopathy, cardiomyopathy and the formation of localized pseudo tumors. The determination of the concentration of metals in body fluids and tissues can be used for predicting failure of hip or knee replacements to prevent subsequent severe intoxications. A semi-automated robot-assisted measurement system is presented for the determination of heavy metals in human tissue samples using inductively coupled plasma mass spectrometry (ICP-MS). The manual and automated measurement processes were similarly validated using certified reference material and the results are compared and discussed. The automation system was successfully applied in the determination of heavy metals in human tissue; the first results are presented.

scholarly journals Natural Building Materials for Interior Fitting and Refurbishment—What about Indoor Emissions?

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 234
Author(s):  
Matthias Richter ◽  
Wolfgang Horn ◽  
Elevtheria Juritsch ◽  
Andrea Klinge ◽  
Leon Radeljic ◽  
...  
Keyword(s):  
Building Materials ◽  
Negative Impact ◽  
Well Being ◽  
Testing Time ◽  
Evaluation Scheme ◽  
Partition Walls ◽  
Health Related ◽  
Internal Partition ◽  
Multiple Materials ◽  
Natural Building

Indoor air quality can be adversely affected by emissions from building materials, consequently having a negative impact on human health and well-being. In this study, more than 30 natural building materials (earth dry boards and plasters, bio-based insulation materials, and boards made of wood, flax, reed, straw, etc.) used for interior works were investigated as to their emissions of (semi-)volatile organic compounds ((S)VOC), formaldehyde, and radon. The study focused on the emissions from complete wall build-ups as they can be used for internal partition walls and the internal insulation of external walls. Test chambers were designed, allowing the compounds to release only from the surface of the material facing indoors under testing parameters that were chosen to simulate model room conditions. The emission test results were evaluated using the AgBB evaluation scheme, a procedure for the health-related evaluation of construction products and currently applied for the approval of specific groups of building materials in Germany. Seventeen out of 19 sample build-ups tested in this study would have passed this scheme since they generally proved to be low-emitting and although the combined emissions of multiple materials were tested, 50% of the measurements could be terminated before half of the total testing time.

Study on Reliability of the Tower Crane Jib

2010 ◽  
Vol 118-120 ◽  
pp. 479-486
Author(s):  
Gui Yu Lin ◽  
Wei Wei Li
Keyword(s):  
Probabilistic Method ◽  
Direct Impact ◽  
Allowable Stress ◽  
Main Method ◽  
Tower Crane ◽  
Safety Production

The jib is an important component for the tower crane. The reliability of the tower crane jib has a direct impact on the safety production. In the current crane industry, the traditional allowable stress method is still the main method for designing tower crane jib. As a result, the reliability of the tower crane jib cannot be given quantitatively. In this paper, by using the probabilistic method, the reliability of a tower crane jib is worked out, and a design way based on the reliability for the tower crane jib is provided.

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