scholarly journals Carbon Source Starvation of a Sulfate-Reducing Bacterium–Elevated MIC Deterioration of Tensile Strength and Strain of X80 Pipeline Steel

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhong Li ◽  
Jike Yang ◽  
Huihua Guo ◽  
Sith Kumseranee ◽  
Suchada Punpruk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Carbon Source ◽  
Tensile Strain ◽  
Ultimate Tensile Stress ◽  
Sulfate Reducing ◽  
Source Level ◽  
Pit Depth ◽  
Sessile Cell

It is known that starved sulfate-reducing bacterial biofilms corrode carbon steel more aggressively because they use electrons from elemental iron oxidation as an alternative source of energy. This work used carbon source starvation to vary MIC (microbiologically influenced corrosion) severity for studying subsequent MIC impacts on the degradation of X80 carbon steel mechanical properties. X80 square coupons and dogbone coupons were immersed in ATCC 1249 culture medium (200 ml in 450-ml anaerobic bottles) inoculated with Desulfovibrio vulgaris for 3-day pre-growth and then for an additional 14 days in fresh media with adjusted carbon source levels for starvation testing. After the starvation test, the sessile cell counts (cells/cm2) on the dogbone coupons in the bottles with carbon source levels of 0, 10, 50, and 100% (vs that in the full-strength medium) were 8.1 × 106, 3.2 × 107, 8.3 × 107, and 1.3 × 108, respectively. The pit depths from the X80 dogbone coupons were 1.9 μm (0%), 4.9 μm (10%), 9.1 μm (50%), and 6.4 μm (100%). The corresponding weight losses (mg/cm2) from the square coupons were 1.9 (0%), 3.3 (10%), 4.4 (50%), and 3.7 (100%). The 50% carbon source level had the combination of carbon starvation without suffering too much sessile cell loss. Thus, both its pit depth and weight loss were the highest. The electrochemical tests corroborated the pit depth and weight loss trends. The tensile tests of the dogbone coupons after the starvation incubation indicated that sulfate-reducing bacteria (SRB) made X80 more brittle and weaker. Compared with the fresh (no-SRB-exposure) X80 dogbone coupon’s ultimate tensile strain of 13.6% and ultimate tensile stress of 860 MPa, the 50% carbon source level led to the lowest ultimate tensile strain of 10.3% (24% loss when compared with the fresh dogbone) and ultimate tensile stress of 672 MPa (22% loss). The 100% carbon source level had a smaller loss in ultimate tensile strain than the 50% carbon source level, followed by 10% and then 0%. Moreover, the 100% carbon source level had a smaller loss in ultimate tensile strength than the 50%, followed by 10% and 0% in a tie. This outcome shows that even in the 17-day short-term test, significant degradation of the mechanical properties occurred and more severe MIC pitting caused more severe degradation.

scholarly journals Performance Evaluation of Cellulose Nanofiber with Residual Hemicellulose as a Nanofiller in Polypropylene-Based Nanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1064
Author(s):  
Mohd Nor Faiz Norrrahim ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Mohd Ali Hassan ◽  
Nor Azowa Ibrahim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Weight Loss ◽  
Tensile Strength ◽  
Performance Evaluation ◽  
Flexural Strength ◽  
Decomposition Temperature ◽  
Cellulose Nanofiber ◽  
Hemicellulose Removal ◽  
Reinforcement Material

Residual hemicellulose could enhance cellulose nanofiber (CNF) processing as it impedes the agglomeration of the nanocellulose fibrils and contributes to complete nanofibrillation within a shorter period of time. Its effect on CNF performance as a reinforcement material is unclear, and hence this study seeks to evaluate the performance of CNF in the presence of amorphous hemicellulose as a reinforcement material in a polypropylene (PP) nanocomposite. Two types of CNF were prepared: SHS-CNF, which contained about 11% hemicellulose, and KOH-CNF, with complete hemicellulose removal. Mechanical properties of the PP/SHS-CNF and PP/KOH-CNF showed an almost similar increment in tensile strength (31% and 32%) and flexural strength (28% and 29%) when 3 wt.% of CNF was incorporated in PP, indicating that hemicellulose in SHS-CNF did not affect the mechanical properties of the PP nanocomposite. The crystallinity of both PP/SHS-CNF and PP/KOH-CNF nanocomposites showed an almost similar value at 55–56%. A slight decrement in thermal stability was seen, whereby the decomposition temperature at 10% weight loss (Td10%) of PP/SHS-CNF was 6 °C lower at 381 °C compared to 387 °C for PP/KOH-CNF, which can be explained by the degradation of thermally unstable hemicellulose. The results from this study showed that the presence of some portion of hemicellulose in CNF did not affect the CNF properties, suggesting that complete hemicellulose removal may not be necessary for the preparation of CNF to be used as a reinforcement material in nanocomposites. This will lead to less harsh pretreatment for CNF preparation and, hence, a more sustainable nanocomposite can be produced.

Preparation and characterizations of ternary biodegradable blends composed of polylactide, poly(ε-caprolactone), and wood flour

2012 ◽  
Vol 32 (6-7) ◽  
pp. 435-444 ◽  
Author(s):  
Hsin-Tzu Liao ◽  
Chin-San Wu
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Fourier Transform ◽  
Wood Flour ◽  
High Price ◽  
Infrared Analysis ◽  
Melt Blending ◽  
Ternary Blends ◽  
Elongation At Break

Abstract Melt blending of polylactide (PLA), poly(ε-caprolactone) (PCL), and wood flour (WF) was performed in an effort to overcome the major drawbacks (brittleness and high price) of PLA. In addition, the acrylic acid (AA)-grafted PLA70PCL30 (PLA70PCL30-g-AA) was used as the alternative for the preparation of ternary blends to improve the compatibility and the dispersability of WF within the PLA70PCL30 matrix. As expected, PCL improved the elongation at break and the toughness of PLA but decreased the tensile strength and modulus. Because the hydrophilic WF is dispersed physically in the hydrophobic PLA70PCL30 matrix, as the result of Fourier transform infrared analysis, the mechanical properties of PLA70PCL30 became noticeably worse when it was blended with WF. This problem was successfully conquered by using PLA70PCL30-g-AA to replace PLA70PCL30 due to the formation of an ester carbonyl group between PLA70PCL30-g-AA and WF. Furthermore, the PLA70PCL30-g-AA/WF blend provided a plateau tensile strength at break when the WF content was up to 50 wt%. PLA70PCL30/WF exhibited a tensile strength at break of approximately 3–25 MPa more than PLA70PCL30-g-AA/WF. By using p-cresol and tyrosinase, the enzymatic biodegradable test showed that PLA70PCL30-g-AA is somewhat more biodegradable than PLA70PCL30 because the former has better water absorption. After 16 weeks, the weight loss of the PLA70PCL30/WF (50 wt%) composite was >80%. PLA70PCL30-g-AA/WF exhibited a weight loss of approximately 1–12 wt% more than PLA70PCL30-g-AA/WF. It was also found that the addition of WF to PLA70PCL30 or PLA70PCL30-g-AA decreased the crystallinity of PLA and PCL in PLA70PCL30 or PLA70PCL30-g-AA and then increased their biodegradable property.

scholarly journals Crazing Effect on the Bio-Based Conducting Polymer Film

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3425
Author(s):  
Pei-Yi Wong ◽  
Akiyoshi Takeno ◽  
Shinya Takahashi ◽  
Sook-Wai Phang ◽  
Azizah Baharum
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Polymer Film ◽  
Polymer Chain ◽  
Tensile Strain ◽  
Young Modulus ◽  
Optical Microscope ◽  
Poly Lactic Acid ◽  
Pani Film ◽  
Polymer Waste

The biodegradability problem of polymer waste is one of the fatal pollutFions to the environment. Enzymes play an essential role in increasing the biodegradability of polymers. In a previous study, antistatic polymer film based on poly(lactic acid) (PLA) as a matrix and polyaniline (PAni) as a conductive filler, was prepared. To solve the problem of polymer wastes pollution, a crazing technique was applied to the prepared polymer film (PLA/PAni) to enhance the action of enzymes in the biodegradation of polymer. This research studied the biodegradation test based on crazed and non-crazed PLA/PAni films by enzymes. The presence of crazes in PLA/PAni film was evaluated using an optical microscope and scanning electron microscopy (SEM). The optical microscope displayed the crazed in the lamellae form, while the SEM image revealed microcracks in the fibrils form. Meanwhile, the tensile strength of the crazed PLA/PAni film was recorded as 19.25 MPa, which is almost comparable to the original PLA/PAni film with a tensile strength of 20.02 MPa. However, the Young modulus decreased progressively from 1113 MPa for PLA/PAni to 651 MPa for crazed PLA/PAni film, while the tensile strain increased 150% after crazing. The significant decrement in the Young modulus and increment in the tensile strain was due to the craze propagation. The entanglement was reduced and the chain mobility along the polymer chain increased, thus leading to lower resistance to deformation of the polymer chain and becoming more flexible. The presence of crazes in PLA/PAni film showed a substantial change in weight loss with increasing the time of degradation. The weight loss of crazed PLA/PAni film increased to 42%, higher than that of non-crazed PLA/PAni film with only 31%. The nucleation of crazes increases the fragmentation and depolymerization of PLA/PAni film that induced microbial attack and led to higher weight loss. In conclusion, the presence of crazes in PLA/PAni film significantly improved enzymes’ action, speeding up the polymer film’s biodegradability.

scholarly journals Karakteristik Bioplastik dari Pati Buah Lindur (Bruguiera gymnorrizha)

2018 ◽  
Vol 7 (1) ◽  
pp. 49-59
Author(s):  
Johan Budiman ◽  
Rodiana Nopianti ◽  
Shanti Dwita Lestari
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Degradation Rate ◽  
Water Resistance ◽  
Block Design ◽  
Percent Elongation ◽  
Starch Concentration ◽  
Randomized Block Design ◽  
Biodegradation Test

This research studied the characteristics of bioplastic from large-leafed mangrove (Bruguiera gymnorrizha) starch. This research was arranged used Randomized Block Design (RBD) model, with different starch concentration (0.5%, 1%, 1.5% and 2%) as treatment. The parameters observed were mechanical properties (tensile strength and percent elongation), thickness, water uptake and biodegradation test. The result showed that the starch concentration was not significant, (P>0.05) affected tensile strength and water resistance. Different between treatments was observed as for elongation, thickness and biodegradation test significant (P<0.05). The results obtained from the bioplastic research of large-leafed mangrove starch for tensile strength ranged from 24.59 MPa – 32.91 MPa, percent elongation 2.93% – 4.88%, thickness 0.05 mm – 0,11 mm, water resistance 108.06% – 111.09% and biodegradation test with percent weight loss 17.91% – 54.40% with the highest degradation rate 18.13 – 3.62 mg /15 days burial. The best treatment was obtained by using 1,5% starch, 4 g chitosan and 15% glycerol or equal to starch : chitosan 1.5 g : 4 g and 0.9 mL glycerol.

Optimisation of Tensile Strength and Weight Loss via Taguchi and Response Surface Method for Natural Rubber Latex Film Consisting Cassava Peel as a Bio-Based Filler

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mahiratul Husna Mustaffar ◽  
◽  
Aliff Hisyam A. Razak ◽  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Latex ◽  
Synthetic Rubber ◽  
Surface Method ◽  
Prepared Composite ◽  
Cassava Peel

Disposal latex and synthetic rubber gloves is troublesome such that disposal via incineration and land fill may release poisonous gasses and contaminate soil and water, respectively. As solution to latex and synthetic rubber, biodegradable glove is extensively studied. A bio-based filler is extracted from food waste and blended into natural rubber latex (NRL) as a composite NRL. The effect of biodegradability of composite NRL was studied by varying the loading of bio-based filler in a form of starch dispersion and blended into NRL mixture. Herein some amount of starch can be extracted from cassava peel to be incorporated in NRL for a sustainable and yet biodegradable glove. Previous work on incorporation of cassava-peel filler in NRL has shown a biodegradability without compromising the pristine strength of NRL film at 50% loading starch. In this project, tensile strength and weight loss of prepared composite NRL films were optimised via Taguchi and Response Surface Method (RSM) by means of Design Expert software by varying starch/filler loading, curing temperature and curing drying duration. Due to inadequate data, the optimisation from that previous prepared composite NRL was compared with similar work which utilising NRL and bio-based filler. For Pulungan (2020) study, it can be concluded that the tensile strength of cassava peel starch biodegradable film has the best condition at 50°C to 60°C at approximately 5.5 hours. Elongation optimum conditions shows contrast value of temperature and time. Meanwhile, for Wendy (2020) study, it shows the best percentage loading of cassava-peel starch is at 20% to achieve high stress and strain at break. The optimised mechanical properties via Taguchi and RSM are rather different and hence validation on mechanical properties at above mentioned conditions need to be performed experimentally.

Characterization and Properties of Cellulose Oleate

2011 ◽  
Vol 197-198 ◽  
pp. 1306-1309 ◽  
Author(s):  
Feng Yuan Huang ◽  
Yan Yu ◽  
Xiao Jie Wu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Oleic Acid ◽  
Tensile Strain ◽  
Homogeneous System ◽  
Hydroxyl Groups ◽  
Distribution Analysis ◽  
Fitting Method ◽  
Ft Ir ◽  
Curve Fitting Method

Cellulose Oleate (CO) was synthesized by acylating cellulose in homogeneous system with p-toluenesulfonyl chloride (Tos-Cl) and oleic acid. The structure of CO was characterized by FT-IR, and degree of substitution (DS) of CO was determined by saponification method. Substituent distribution analysis was carried out with curve-fitting method, and the results indicated that acyl reaction of cellulose with oleic acid preferred to react at primary hydroxyl groups. The CO converted into films by casting. The mechanical properties of CO films were investigated. With the increase of DS, the tensile strength decreases gradually, but the tensile strain increases apparently.

scholarly journals Comparison of 304 SS, 2205 SS, and 410 SS Corrosion by Sulfate-Reducing Desulfovibrio ferrophilus

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Junlei Wang ◽  
Hongfang Liu ◽  
Pruch Kijkla ◽  
Sith Kumseranee ◽  
Suchada Punpruk ◽  
...  
Keyword(s):  
Weight Loss ◽  
Microbiologically Influenced Corrosion ◽  
Significant Weight Loss ◽  
Electrochemical Tests ◽  
Sulfate Reducing ◽  
Large Weight Loss ◽  
Stainless Steel 304 ◽  
Corrosion Behaviors ◽  
Pit Depth ◽  
Reducing Bacteria

Three types of stainless steel (304 SS, 410 SS, and 2205 SS) were evaluated for their corrosion behaviors in microbiologically influenced corrosion (MIC) by Desulfovibrio ferrophilus strain IS5, a relatively new and very corrosive sulfate-reducing bacteria (SRB) strain. The incubation lasted for 7 days in enriched artificial seawater at 28°C and the results showed that 410 SS had a rather large weight loss (6.2 mg/cm2) and a maximum pit depth (118 µm), but 2205 SS and 304 SS did not suffer from significant weight loss or pitting. Electrochemical tests indicated that 2205 SS was slightly more resistant to SRB MIC than 304 SS, while 410 SS was far less resistant.

Structure and Mechanical Properties of Carboxylated Styrene-Butadiene Rubber (XSBR)/Pristine Clay Nanocomposites

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Mahdi Abdollahi ◽  
Ali Rahmatpour ◽  
Homayon Hossein Khanli
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tensile Strain ◽  
Clay Content ◽  
Mechanical Tests ◽  
Styrene Butadiene Rubber ◽  
Clay Nanocomposites ◽  
Butadiene Rubber ◽  
Carboxylated Styrene Butadiene Rubber ◽  
Styrene Butadiene

AbstractCarboxylated styrene- butadiene rubber (XSBR)/clay nanocomposites were prepared by mixing the XSBR latex with aqueous clay dispersion and cocoagulating the mixture. TEM and XRD were applied to characterize the structure of nanocomposites. Fully exfoliated structure was observed for the nanocomposites containing equal to or less than 10 phr (weight parts per hundred) clay. With increasing the clay content to 20 phr, both non-exfoliated (stacked layers) and exfoliated structures can be observed simultaneously in the nanocomposites. The results of mechanical tests on the vulcanized clay-free XSBR and XSBR/clay nanocomposites showed that the nanocomposites present better mechanical properties than clay-free XSBR vulcanizate. Furthermore, modulus, tensile strength, tensile strain at break and hardness (shore A) increased with increasing the clay content, indicating the nanoreinforcement effect of clay on the mechanical properties of XSBR/ clay nanocomposites.

Atomistic study of the mechanical properties of metallic-glass nanowires

2011 ◽  
Vol 1297 ◽  
Author(s):  
K. Koshiyama ◽  
K. Shintani
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Strength ◽  
Metallic Glass ◽  
Tensile Strain ◽  
Amorphous Structure ◽  
Structure Change ◽  
Atomistic Study ◽  
B2 Structure ◽  
Dynamics Method

ABSTRACTMelt-growth simulations based on the molecular-dynamics method for both the Cu-Zr and Ni-Al crystalline nanowires of B2 structure are performed to produce metallic-glass nanowires of amorphous structure. Next, tensile deformations of these nanowires are simulated at various temperatures. For the sake of comparison, Cu-Zr and Ni-Al crystalline nanowires of B2 structure are also elongated. It is revealed that the tensile strength of the metallic-glass nanowires is third or fourth of the tensile strength of the crystalline nanowires. Increasing tensile strain, the Cu-Zr crystalline nanowires of B2 structure change their structure twice, whereas the metallic-glass nanowires only decrease their thicknesses locally, and necking takes place.

scholarly journals The Influences of Dehydration on the Mechanical Properties of Human Dentin

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 336
Author(s):  
Abu Faem Mohammad Almas Chowdhury ◽  
Arefin Alam ◽  
MD Refat Readul Islam ◽  
Monica Yamauti ◽  
Mohammad Shafiqul Alam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Statistical Significance ◽  
Distilled Water ◽  
Third Molars ◽  
Complex Dynamic ◽  
Human Dentin

The complex, dynamic, and hydrated microstructures of human dentin serve as the major determinant for the restorative performance of biomaterials. This study aimed to evaluate the mechanical properties of human dentin under different hydration conditions. The occlusal dentin of five third molars was exposed and cut into 1 mm2 dentin slabs. The slabs were then polished and further cut into 1 mm2 dentin beams and stored in distilled water. Two beams/tooth were used for testing their hardness (H) and elastic modulus (E) at 5 min (baseline), 1 h, and 24 h after dehydration (23 °C and 30% RH), and also for measuring weight at following dehydration times: 0 min, 5 min, 1 h, and 24 h. Five additional molars were employed to prepare 0.4 mm2 dentin beams (3/tooth) for determining ultimate tensile strength (UTS) at 5 min (baseline), 1 h, and 24 h post-dehydration. Statistical significance was set at α = 0.05. Dehydration time significantly affected H, E, weight-loss, and UTS of dentin (p < 0.05). H and E values showed a strongly positive and significant correlation (r > 0.5, p < 0.05). Dehydration can substantially modify the mechanical properties of dentin, leading to misinterpretation of restorative outcomes in vitro.

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