Development of a laboratory test for microbial involvement in accelerated low water corrosion

2018 ◽  
Vol 39 (3) ◽  
pp. 170
Author(s):  
Scott Wade ◽  
Linda Blackall
Keyword(s):  
Laboratory Test ◽  
Microbial Consortium ◽  
General Term ◽  
Microbial Consortia ◽  
Structural Safety ◽  
Microbially Influenced Corrosion ◽  
Test Conditions ◽  
Safety Design ◽  
Preliminary Study ◽  
Metallic Corrosion

Microbially influenced corrosion (MIC) is a general term for when microbes affect material corrosion processes. The rapid corrosion that can occur due to MIC can cause significant dangers and costs for owners of relevant assets in relation to predicting structural safety, design of new structures and maintenance. Verification and/or prediction that a structure may be subject to MIC is not straightforward and, when metal surfaces are involved, it requires a series of metallurgical, microbiological and chemical tests. A useful part of this testing can be laboratory-based studies of microbial consortium samples from the environment of interest. However, there are no standard guidelines for how to perform such tests. Here we report the results of a preliminary study of laboratory corrosion simulations with biomass from a marine metallic corrosion event and show that simple changes in the test conditions can alter the rate of corrosion and the composition of microbial consortia during the test.

scholarly journals A proposal to determine the distribution of lateral forces from loaded recycled plastic drainage kerbs

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Fin O’Flaherty ◽  
Fathi Al-Shawi
Keyword(s):  
Laboratory Test ◽  
Detailed Analysis ◽  
Test Data ◽  
Lateral Force ◽  
Measuring Device ◽  
Test Methodology ◽  
Lateral Forces ◽  
Test Conditions ◽  
Fit For Purpose ◽  
Construction Product

AbstractThis study presents a detailed analysis of the lateral forces generated as a result of vertically applied loads to recycled plastic drainage kerbs. These kerbs are a relatively new addition to road infrastructure projects. When concrete is used to form road drainage kerbs, its deformation is minimum when stressed under heavy axle loads. Although recycled plastic kerbs are more environmentally friendly as a construction product, they are less stiff than concrete and tend to deform more under loading leading to a bursting type, lateral force being applied to the haunch materials, the magnitude of which is unknown. A method is proposed for establishing the distribution of these lateral forces resulting from deformation under laboratory test conditions. A load of 400 kN is applied onto a total of six typical kerbs in the laboratory in accordance with the test standard. The drainage kerbs are surrounded with 150 mm of concrete to the front and rear haunch and underneath as is normal during installation. The lateral forces exerted on the concrete surround as a result of deformation of the plastic kerbs are determined via a strain measuring device. Analysis of the test data allows the magnitude of the lateral forces to the surrounding media to be determined and, thereby, ensuring the haunch materials are not over-stressed as a result. The proposed test methodology and subsequent analysis allows for an important laboratory-based assessment of any typical recycled plastic drainage kerbs to be conducted to ensure they are fit-for-purpose in the field.

Case Study on Modeling Fire Action Complexity in Fire Safety Engineering of Structures

2017 ◽  
Vol 21 ◽  
pp. 102-107
Author(s):  
Constantin Sorin Scutarasu ◽  
Dan Diaconu-Şotropa ◽  
Marinela Barbuta
Keyword(s):  
Numerical Simulation ◽  
Fire Safety ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Structural Safety ◽  
Modular Organization ◽  
Field Of Study ◽  
Safety Design ◽  
Fire Safety Design ◽  
Technical Regulations

Important goals in the fire safety design, such as preventing loss of life and goods damage, are achieved by maintaining the stability of structures exposed to fire for a period of time established by norms and standards. Real fire scenarios confirm that the specific technical regulations which actually have a prescriptive character (both national and international) do not deal with sufficient possibilities regarding the assessment of structural fire safety. The new approach on structural safety, based on engineering notions, gives us additional prospects on it and it is included in the issues of the fire safety design of structures. A relatively new field of study, known by a few professionals focused on fire safety (but well acknowledged in the research area), fire safety design met with lots of changes and restructuring of the governing concepts and procedures and of the information with which they operate, due to the fast accumulation of experience in this area of engineering activity. Consequently, after countries such as Australia, Canada, New Zeeland or USA provided towards professionals specific technical regulations for fire safety design, groups of experts in these aforementioned countries have joined their forces to try to diminish the differences that exists between those regulations and to give a unitary character to them, a better conceptualized engineering approach of the fire safety design. The result: occurrence of the publication International Fire Engineering Guidelines (last edition from 2005). The systematic approach of fire safety design in constructions pointed, once again, the possibility of modular organization of this field of study, the relations between modules being established according to the objective or objectives in the fire safety design for a specified building. This article aims to put forward, from this modularized perspective, the study of the fire safety design of a building exposed to fire; hence, the practical part of the article exhibits the numerical simulation of initialization and development of the fire process for a large scale religious building. The main features of the building represent the amount of space that facilitates the spreading of smoke and warm gases and which increases the risk of damaging the structural reinforced concrete elements. Application calls to specific numerical simulation with a higher degree of credibility, such as those realized by the FDS (Fire Dynamics Simulation) software.

Metagenomics Study To Compare The Taxonomy And Metabolism of a Lignocellulolytic Microbial Consortium Cultured in Different Carbon Conditions

2021 ◽  
Author(s):  
Qinggeer BORJIGIN ◽  
Bizhou ZHANG ◽  
Xiaofang Yu ◽  
Julin Gao ◽  
Xin ZHANG ◽  
...  
Keyword(s):  
Microbial Consortium ◽  
Agricultural Waste ◽  
Taxonomic Diversity ◽  
Taxonomic Composition ◽  
Microbial Consortia ◽  
Rich Diversity ◽  
Cazy Database ◽  
Taxonomic Affiliation ◽  
In Situ Biodegradation

Abstract A lignocellulolytic microbial consortium holds promise for the in situ biodegradation of crop straw and the comprehensive and effective utilization of agricultural waste. In this study, we applied metagenomics technology to comprehensively explore the metabolic functional potential and taxonomic diversity of the microbial consortia CS (cultured on corn stover) and FP (cultured on filter paper).Analyses of the metagenomics taxonomic affiliation data showed considerable differences in the taxonomic composition and functional profile of the microbial consortia CS and FP. The microbial consortia CS primarily contained members from the genera Pseudomonas, Stenotrophomonas, Achromobacter, Dysgonomonas, Flavobacterium and Sphingobacterium, as well as Cellvibrio, Azospirillum, Pseudomonas, Dysgonomonas and Cellulomonas in FP. The COG and KEGG annotation analyses revealed considerable levels of diversity. Further analysis determined that the CS consortium had an increase in the acid and ester metabolism pathways, while carbohydrate metabolism was enriched in the FP consortium. Furthermore, a comparison against the CAZy database showed that the microbial consortia CS and FP contain a rich diversity of lignocellulose degrading families, in which GH5, GH6, GH9, GH10, GH11, GH26, GH42, and GH43 were enriched in the FP consortium, and GH44, GH28, GH2, and GH29 increased in the CS consortium. The degradative mechanism of lignocellulose metabolism by the two microbial consortia is similar, but the annotation of quantity of genes indicated that they are diverse and vary greatly. The lignocellulolytic microbial consortia cultured under different carbon conditions (CS and FP) differed substantially in their composition of the microbial community at the genus level. The changes in functional diversity were accompanied with variation in the composition of microorganisms, many of which are related to the degradation of lignocellulolytic materials. The genera Pseudomonas, Dysgonomonas and Sphingobacterium in CS and the genera Cellvibrio and Pseudomonas in FP exhibited a much wider distribution of lignocellulose degradative ability.

scholarly journals Current Advances in the Biodegradation and Bioconversion of Polyethylene Terephthalate

2021 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Xinhua Qi ◽  
Wenlong Yan ◽  
Zhibei Cao ◽  
Mingzhu Ding ◽  
Yingjin Yuan
Keyword(s):  
Polyethylene Terephthalate ◽  
Microbial Consortium ◽  
Tricarboxylic Acid Cycle ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Microbial Consortia ◽  
Plastic Pollution ◽  
One Step ◽  
Complex Polymers ◽  
The One

Polyethylene terephthalate (PET) is a widely used plastic that is polymerized by terephthalic acid (TPA) and ethylene glycol (EG). In recent years, PET biodegradation and bioconversion have become important in solving environmental plastic pollution. More and more PET hydrolases have been discovered and modified, which mainly act on and degrade the ester bond of PET. The monomers, TPA and EG, can be further utilized by microorganisms, entering the tricarboxylic acid cycle (TCA cycle) or being converted into high value chemicals, and finally realizing the biodegradation and bioconversion of PET. Based on synthetic biology and metabolic engineering strategies, this review summarizes the current advances in the modified PET hydrolases, engineered microbial chassis in degrading PET, bioconversion pathways of PET monomers, and artificial microbial consortia in PET biodegradation and bioconversion. Artificial microbial consortium provides novel ideas for the biodegradation and bioconversion of PET or other complex polymers. It is helpful to realize the one-step bioconversion of PET into high value chemicals.

scholarly journals Contributions of Microbial “Contact Leaching” to Pyrite Oxidation under Different Controlled Redox Potentials

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 856
Author(s):  
Bingxu Dong ◽  
Yan Jia ◽  
Qiaoyi Tan ◽  
Heyun Sun ◽  
Renman Ruan
Keyword(s):  
Redox Potential ◽  
Dissolution Rate ◽  
Elemental Sulfur ◽  
Microbial Consortium ◽  
Pyrite Oxidation ◽  
Microbial Consortia ◽  
Redox Potentials ◽  
Sulfur Passivation ◽  
Sulfur Oxidizing ◽  
Contact Oxidation

The function of microbial contact leaching to pyrite oxidation was investigated by analyzing the differences of residue morphologies, leaching rates, surface products, and microbial consortia under different conditions in this study. This was achieved by novel equipment that can control the redox potential of the solution and isolate pyrite from microbial contact oxidation. The morphology of residues showed that the corrosions were a little bit severer in the presence of attached microbes under 750 mV and 850 mV (vs. SHE). At 650 mV, the oxidation of pyrite was undetectable even in the presence of attached microbes. The pyrite dissolution rate was higher with attached microbes than that without attached microbes at 750 mV and 850 mV. The elemental sulfur on the surface of pyrite residues with sessile microorganisms was much less than that without attached microbes at 750 mV and 850 mV, showing that sessile acidophiles may accelerate pyrite leaching by reducing the elemental sulfur inhibition. Many more sulfur-oxidizers were found in the sessile microbial consortium which also supported the idea. The results suggest that the microbial “contact leaching” to pyrite oxidation is limited and relies on the elimination of elemental sulfur passivation by attached sulfur-oxidizing microbes rather than the contact oxidation by EPS-Fe.

scholarly journals Development of 6 U CubeSat’s Deployable Solar Panel with Burn Wire Triggering Holding and Release Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Tae-Yong Park ◽  
Bong-Geon Chae ◽  
Hyun-Ung Oh
Keyword(s):  
Random Vibration ◽  
Printed Circuit Board ◽  
Solar Panel ◽  
Circuit Board ◽  
Structural Safety ◽  
Release Mechanism ◽  
Printed Circuit ◽  
Test Conditions ◽  
Wire Cutting ◽  
Vibration Tests

In the present work, a deployable solar panel based on a burn wire triggering holding and release mechanism was developed for use of 6 U CubeSat. The holding and release mechanism was designed based on a nichrome burn wire cutting method widely used for CubeSat applications. However, it provides a high loading capability, reliable wire cutting, multiplane constraints, and handling simplicity during the tightening process of wire. A demonstration model of a printed circuit board-based solar panel stiffened by a high-pressure fiberglass-laminated G10 material was fabricated and tested to validate the effectiveness of the design and functionality of the mechanism under various test conditions. The structural safety of the solar panel combined with the mechanism in a launch vibration environment was verified through sine and random vibration tests at qualification level.

scholarly journals Thauera aminoaromatica MZ1T Identified as a Polyhydroxyalkanoate-Producing Bacterium within a Mixed Microbial Consortium

2020 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Dana I. Colpa ◽  
Wen Zhou ◽  
Jan Pier Wempe ◽  
Jelmer Tamis ◽  
Marc C. A. Stuart ◽  
...  
Keyword(s):  
Pure Culture ◽  
Pilot Plant ◽  
Fossil Fuel ◽  
Microbial Consortium ◽  
Population Analysis ◽  
C:N Ratio ◽  
Microbial Consortia ◽  
Waste Streams ◽  
Reserve Material ◽  
Working Volume

Polyhydroxyalkanoates (PHAs) form a highly promising class of bioplastics for the transition from fossil fuel-based plastics to bio-renewable and biodegradable plastics. Mixed microbial consortia (MMC) are known to be able to produce PHAs from organic waste streams. Knowledge of key-microbes and their characteristics in PHA-producing consortia is necessary for further process optimization and direction towards synthesis of specific types of PHAs. In this study, a PHA-producing mixed microbial consortium (MMC) from an industrial pilot plant was characterized and further enriched on acetate in a laboratory-scale selector with a working volume of 5 L. 16S-rDNA microbiological population analysis of both the industrial pilot plant and the 5 L selector revealed that the most dominant species within the population is Thauera aminoaromatica MZ1T, a Gram-negative beta-proteobacterium belonging to the order of the Rhodocyclales. The relative abundance of this Thauera species increased from 24 to 40% after two months of enrichment in the selector-system, indicating a competitive advantage, possibly due to the storage of a reserve material such as PHA. First experiments with T. aminoaromatica MZ1T showed multiple intracellular granules when grown in pure culture on a growth medium with a C:N ratio of 10:1 and acetate as a carbon source. Nuclear magnetic resonance (NMR) analyses upon extraction of PHA from the pure culture confirmed polyhydroxybutyrate production by T. aminoaromatica MZ1T.

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