Benchmarking the Dual and Compound Techniques-Based Branching Design Strategy Used for Upgrading of Pressurized Hydraulic Systems

2021 ◽  
Vol 143 (2) ◽  
Author(s):  
Waêl Ben Amira ◽  
Ali Triki
Keyword(s):  
Pressure Wave ◽  
Plastic Material ◽  
Conventional Technique ◽  
Steel Pipe ◽  
Low Density Polyethylene ◽  
Piping System ◽  
Low Density ◽  
Hydraulic Systems ◽  
Transient Pressure ◽  
Pipe Flow Model

Abstract Prior research has recognized that the compound- and dual-technique-based branching redesign measures, used as alternatives to the conventional technique-based one, were effective in upgrading steel pipe-based pressurized hydraulic systems. Principally, the compound technique used two different plastic material types for the short-penstock instead of the single material type utilized in the conventional technique. However, the dual technique is based on splitting the single penstock installed in the conventional technique into a set of dual subpenstocks placed at each connection of the main-piping system to hydraulic parts. This handling aimed at improving the conventional technique efficiency with regard to the tradeoff between the magnitude attenuation and period expansion effects of the transient pressure-wave signal. Accordingly, this study proposed a comprehensive comparison between the compound- and dual-technique-based branching strategy with particular focus on the tradeoff between the two last parameters. The plastic material types demonstrated in this study included the high- or low-density polyethylene. The application addressed a waterhammer maneuver initiated into a reservoir-steel-pipe-valve system. Numerical computations used the method of characteristics for the discretization of the 1D extended pressurized-pipe flow model, embedding the Kelvin–Voigt and Vitkovsky formulations. The finding of this study suggested that the high- or low-density polyethylene (HDPE–LDPE) setup of the compound technique is the most prominent protected system setup, providing an acceptable tradeoff between the attenuation of magnitude and the expansion of the period of pressure-wave oscillation.

Biodegradation of Polyethylene Microplastic using Culturable Coral-Associated Bacteria Isolated from Corals of Karimunjawa National Park

2021 ◽  
Vol 26 (4) ◽  
pp. 237-246
Author(s):  
Prastyo Abi Widyananto ◽  
Sakti Imam Muchlissin ◽  
Agus Sabdono ◽  
Bambang Yulianto ◽  
Fauziah Shahul Hamid ◽  
...  
Keyword(s):  
Coral Reef ◽  
National Park ◽  
Plastic Material ◽  
Low Density Polyethylene ◽  
Phase Identification ◽  
Low Density ◽  
Bacterial Isolates ◽  
Plastic Pollution ◽  
Bacterial Gene ◽  
Associated Bacteria

Polyethylene is a plastic material that was globally produced and is well known as a non-degradable pollutant product. Plastic pollution, primarily microplastics, have been distributed to coral reef ecosystems, where these areas are ecosystems with high productivity. Karimunjawa National Park in Indonesia is one of the protected areas for coral reef ecosystem habitat in Central Java, threatened by microplastic contamination. Recent studies have shown that coral-associated bacteria have an adequate ability to degrade marine pollutant materials. No one has reported that the use of indigenous coral-associated bacteria has the potential for microplastic biodegradation, especially low-density polyethylene microplastic materials. Hence, the objective of this study was to find the potential of microplastic biodegradation agents derived from coral-associated bacteria in Karimunjawa National Park area. Various coral life-forms were isolated in July 2020 from conservation areas and areas with anthropogenic influences. Bacterial isolates were screened using tributyrin and polycaprolactone as substrates to reveal potential microplastic degradation enzymes. The total isolation results obtained 92 bacterial isolates, and then from the result of enzyme screening, there were 7 active bacteria and only 1 bacteria that potential to degrade polyethylene. LBC 1 showed that strain could degrade by 2.25±0.0684 % low-density polyethylene microplastic pellet by incubating bacterial growth until the stationary phase. Identification of LBC 1 strain was carried out by extracting DNA and bacterial 16S rRNA sequences. Bacterial gene identification refers to Bacillus paramycoides with a similarity level in the National Center Biotechnology Information database of 99.44%. These results prove that hard coral association bacteria can degrade low-density polyethylene microplastics.

scholarly journals Evaluation of Mechanical Properties and Volatile Organic Extractable to Investigate LLDPE and LDPE Polymers on Final Packaging for Semisolid Formulation

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 113 ◽  
Author(s):  
Arianna Cozzi ◽  
Benedetta Briasco ◽  
Enrico Salvarani ◽  
Barbara Mannucci ◽  
Filippo Fangarezzi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
Raw Materials ◽  
Plastic Material ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Two Samples ◽  
Volatile Organic ◽  
The Difference ◽  
And Performance

Plastic material is used for a wide variety of commercial packaging due to being inexpensive, lightweight, and due to its resistance. In pharmaceutics, container-content compatibility studies are required for product authorization. Many guidelines and publications are available; however, the information is often only related to the raw materials used to produce packaging. During the manufacturing process, substances can be added to improve the product characteristics and performance, resulting in a processed material that is considerably different from the unprocessed material. In this study, the mechanical properties of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) specimens fabricated according to standard ISO 527 and specimens fabricated with the same materials, but obtained from final packaging, were evaluated. Furthermore, we examined the interaction between a semisolid formulation and LLDPE and LDPE as a final packaging, by subjecting two samples to accelerated degradation testing. Then, mechanical properties and volatile organic extractable were evaluated. Simulated solar radiation did not induce changes in the packaging mechanical properties and no extracts were detectable. The thermal shock strongly influenced the mechanical behavior, and interactions between packaging contents were identified. The present work underlines the difference between analyzing the standard ISO specimens versus samples obtained from final packaging in order to evaluate the packaging under real use conditions. An evaluation on the final packaging, instead on standard specimens, can provide information about the plastic material after the manufacturing process and the interaction between packaging and content.

scholarly journals Compressive Strength and Bulk Density of Concrete Hollow Blocks (CHB) Infused with Low-density Polyethylene (LDPE) Pellets

2020 ◽  
Vol 6 (10) ◽  
pp. 1932-1943
Author(s):  
Alvin Joseph Santos Dolores ◽  
Jonathan David Lasco ◽  
Timothy M. Bertiz ◽  
Kimjay M. Lamar
Keyword(s):  
Compressive Strength ◽  
Bulk Density ◽  
Plastic Material ◽  
The Philippines ◽  
Plastic Waste ◽  
Low Density Polyethylene ◽  
Partial Replacement ◽  
Low Density ◽  
Environment Friendly ◽  
Industry Practice

Infusing plastic waste to concrete and masonry structures is an increasingly common industry practice that has the potential to create an environment-friendly material that can improve some of the material’s properties, craft a novel means to repurpose plastic waste, and reduce the need for mining aggregates in the environment. This concept has been studied extensively in different forms of concrete, as shown by several studies; however, there is a dearth of studies focusing on the incorporation plastic waste in concrete hollow blocks (CHB). In this study, we aim to fill that gap by investigating on the effects of incorporating low-density polyethylene (LDPE), a commonly used plastic material, to CHB on its compressive strength and bulk density. Samples of varying percentages of LDPE replacement by volume (0, 10, 20, 30 and 40%) were fabricated and tested. Results showed a general trend of decreasing compressive strength and bulk density upon increasing the amount of LDPE pellets in CHB, which was also observed in previous studies. However, the compressive strength of CHB increased at 10% LDPE replacement, a result similar to a previous study. It was inferred that the strength of the plastic material could have a direct contribution to the compressive strength of CHB at low percentage of aggregate replacement. Statistical analysis showed that the mix with 10% LDPE pellets as replacement to sand was the best among the samples tested. It was shown that CHB infused with LDPE pellets has a higher compressive strength than what is normally used in the Philippines. It was concluded that based on compressive strength and bulk density, LDPE pellets is a viable material to use as partial replacement to sand in non-load bearing CHB.

Exploring the performances of the dual technique-based water hammer redesign strategy in water supply systems

2019 ◽  
Vol 69 (1) ◽  
pp. 6-17 ◽  
Author(s):  
Mounir Trabelsi ◽  
Ali Triki
Keyword(s):  
Pressure Wave ◽  
Oscillation Period ◽  
Conventional Technique ◽  
Water Hammer ◽  
Water Supply Systems ◽  
Piping System ◽  
Wave Oscillation ◽  
Pressure Surge ◽  
Short Section ◽  
Steel Piping

Abstract This paper explored and compared the effectiveness of the inline and branching redesign strategies-based dual technique, implemented to enhance the conventional technique skills in terms of attenuation of positive and negative pressure surge magnitudes and limitation of the spreading of pressure wave oscillation period. Basically, this technique is based on splitting the single inline or branched plastic short-section, used in the conventional technique, into a couple of two sub-short-sections made of two distinct plastic material types. Investigations addressed positive and negative surge initiated water hammer events. Additionally, high and low density polyethylene materials were utilized for sub-short-section material. Results illustrated the reliability of the dual technique in protecting hydraulic systems from excessive pressure rise and drop, and evidenced that the (HDPE/LDPE) sub-short-sections' combination (where the former sub-short-section is attached to the sensitive region of the steel piping system parts, while the latter is attached to the second extremity of the steel piping system) is the most prominent configuration providing the best trade-off between pressure surge attenuation, and pressure wave oscillation period spreading. Lastly, it was found that the pressure head peak (or crest) and the pressure wave oscillation period values were markedly sensitive to the (HDPE) sub-short-section length and diameter.

scholarly journals Comparative assessment of the inline and branching design strategies based on the compound technique

2020 ◽  
Author(s):  
Ali Triki
Keyword(s):  
Pressure Wave ◽  
Control Strategies ◽  
Steel Pipe ◽  
Hydraulic Systems ◽  
Design Strategies ◽  
Trade Off ◽  
Dead End ◽  
Significant Attenuation ◽  
Pressure Magnitude ◽  
Short Section

Abstract The inline or branching water hammer control strategies, which are based on the insertion of compound plastic short-penstock or inline section at the transient-induced region of main pipes, illustrated a promising ability to upgrade steel pipe-based hydraulic systems concerning the extension of admissible pressure level. In this respect, prior results suggested that the specific layout utilizing an (HDPE–LDPE) compound short-penstock (where the (HDPE) sub-short-penstock is attached to the main steel pipe and the (LDPE) sub-short-penstock corresponds to the short-penstock dead-end side) provided significant attenuation of pressure magnitude. Concurrently, recent studies concluded that the (HDPE–LDPE) compound short-section-based inline strategy provided substantial attenuation of pressure magnitude. However, these strategies illustrated a drawback relying on the expansion of the period of pressure wave oscillations. Accordingly, this study assessed and compared the capacities of the compound technique concerning the trade-off between the magnitude-attenuation and the period-expansion of pressure wave oscillations. The findings of these analyses showed that the (HDPE–LDPE) compound short-penstock particular setup of the branching strategy allowed the best trade-off between the attenuation of magnitude and the period expansion of pressure wave oscillations. Furthermore, results showed the competitiveness of the latter upgrading strategy as compared to the (HDPE) or (LDPE) main pipe-based renewed hydraulic systems.

Investigation of Pump Failure-Induced Waterhammer Waves: A Case Study

2021 ◽  
Author(s):  
Ali Triki ◽  
Badreddine Essaidi
Keyword(s):  
Pressure Wave ◽  
Transient Flow ◽  
Pipe Wall ◽  
Plastic Material ◽  
Flow Behavior ◽  
Pipe Material ◽  
Transient Pressure ◽  
Pump Failure ◽  
Material Type ◽  
Numerical Solver

Abstract The present study analyzes the effect of the pipe material type on the transient flow behavior in a pumping system due to an accidental pump shutdown. The material types addressed in this study include steel and High- or Low-Density PolyEthylene (HDPE) or (LDPE); involving elastic and plastic rheological pipe-wall behavior. The numerical solution is developed basing on the Method Of Characteristics used for the discretization of the Extended One-Dimensional pressurized-pipe flow model, incorporating the Kelvin-Voigt and Vitkovsky rules. Experimental data from the literature were used to validate the numerical solver. The proposed numerical algorithm is then used to investigate the transient pressure-wave behavior induced by the power failure to a pumping station composed of an inline connection using different pipe material types. The findings show the severity of such a scenario, in terms of the magnitudes of induced up-surge and down-surge pressure-waves. Furthermore, this research demonstrates that plastic pipe-wall materials allow for substantial attenuation of surge magnitude in conjunction with the expansion of the period of pressure-wave oscillations. The observed attenuation and expansion effects are also found to be highly dependent on the plastic material type. In this respect, the findings indicate that the (LDPE-Steel) piping system's specific layout allows for the best tradeoff between the two last effects.

scholarly journals On the transient flow behavior in pressurized plastic pipe-based water supply systems

2020 ◽  
Author(s):  
Badreddine Essaidi ◽  
Ali Triki
Keyword(s):  
Water Supply ◽  
Pressure Wave ◽  
Transient Flow ◽  
Plastic Material ◽  
Flow Behavior ◽  
Oscillation Period ◽  
Water Supply Systems ◽  
Transient Pressure ◽  
Plastic Pipe ◽  
Supply Systems

Abstract Plastic material pipes such as high- or low-density polyethylene (HDPE or LDPE) are increasingly used in new or renewed water supply systems. Therefore, analysis of water hammer surge-waves initiated into such piping systems deserves investigation. The 1-D pressurized-pipe flow model embedding the Ramos formulation was used to describe the flow behavior in the elastic and plastic pipe-based hydraulic system. Numerical computations were performed using the method of characteristics. First, the numerical solver was validated against experimental data, available from the literature. Then, the proposed solver was applied to explore the transient pressure-wave behavior resulting from the power failure to a pumping station. Results evidenced the severity of such a scenario with regards to induced positive and negative pressure-wave magnitudes. Furthermore, the findings of this study suggested that plastic pipe-wall materials allowed a significant attenuation of pressure-wave magnitude in conjunction with the expansion of the pressure-wave oscillation period. It was also found that the observed attenuation and expansion effects depended strongly upon the plastic material type. In this respect, the results revealed that LDPE provided a better trade-off between the two last effects than HDPE.

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