scholarly journals Performance and Selectivity of Ceramic Membranes in the Ultrafiltration of Model Emulsion in Saline

2017 ◽  
Vol 25 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Konrad Ćwirko ◽  
Agnieszka Kalbarczyk-Jedynak
Keyword(s):  
Service Life ◽  
High Performance ◽  
Ceramic Membranes ◽  
Maritime Transport ◽  
Test Results ◽  
Laboratory Installation ◽  
Offshore Installations ◽  
Temperature And Pressure ◽  
Pressure Resistance ◽  
Model Emulsion

Abstract Oily wastewaters from different onshore and offshore installations and from maritime transport pose a serious threat to the environment so they must be treated by multistage separation also including membrane processes. The main advantages of such membranes are high performance and selectivity, high resistance for temperature and pressure, resistance for acids, bases and solvents, long service life and for application - significant reduction of industries and transport environmental impact. This work presents the results of the process of separation of oil from the emulsion with NaCl addition. Research was performed with a use of laboratory installation with ceramic 300 kDa membrane. The analysis concerned performance and selectivity of a membrane in the function of time and test results have been subsequently compared with the requirements of the IMO.

scholarly journals Experimental Contribution Concerning the Effect of Carbonation Reaction on the Oxygen Permeability of Concrete

2020 ◽  
Author(s):  
Mohamed El Ghazali Belgacem ◽  
Aissa Talah ◽  
Rui Neves ◽  
Farid Belhamel ◽  
Smail Kechidi
Keyword(s):  
Compressive Strength ◽  
Service Life ◽  
High Performance ◽  
Oxygen Permeability ◽  
High Performance Concrete ◽  
Test Results ◽  
Paper Test ◽  
Carbonation Reaction ◽  
Rc Structures ◽  
Concrete Mixtures

Reinforced concrete (RC) structures are prone to steel corrosion that affects their service life. The two main processes, involved in the destruction of the steel-concrete self-protection are the carbonation and the penetration of chlorides. Understanding the behavior of these degrading phenomena is of paramount importance to enhance the field of predicting the service life of RC structures. In this investigation, a total number of 54 cylindrical specimens (150×100 mm2) and 54 cubic specimens (100×100 mm2) from six different concrete mixtures covering a range of water-to-cement ratio (w/c) between 0.76 and 0.36 was tested. The effect of the carbonation reaction on the concrete oxygen permeability (assessed by a recent method), compressive strength, and weight has been investigated. The obtained data were analyzed to establish correlations to predict the oxygen permeability of non-carbonated concrete with concrete characteristics such as w/c ratio and compressive strength. Test results show good correlations. The results of the accelerated carbonation test showed that compressive strength increases with carbonation. Concerning the effect of carbonation reaction on concrete oxygen permeability which is the main goal of this paper, test results showed that carbonation considerably affects the concrete permeability. This result was observed for all concrete mixtures. Moreover, the relationship between carbonation depth and concrete oxygen permeability in ordinary concrete differed than high performance concrete. Furthermore, the increase of the oxygen permeability observed after the carbonation has been justified by the analysis of the Scanning Electron Microscopy images that show the formation of larger pores in comparison with non-carbonated concrete.

Preparation Techniques and Property Evaluations of Highly Air Permeable Needle-Punched Geotextiles

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Service Life ◽  
Mechanical Strength ◽  
Pore Structure ◽  
Test Results ◽  
Needle Punching ◽  
Pet Fibers ◽  
Environmental Requirements ◽  
Preparation Techniques

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.

scholarly journals Unbalanced Vibration Identification of Tangential Threshing Cylinder Induced by Rice Threshing Process

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhong Tang ◽  
Haotian Zhang ◽  
Yuepeng Zhou
Keyword(s):  
Service Life ◽  
Vibration Amplitude ◽  
Rotation Speed ◽  
Resonance Phenomenon ◽  
Test Results ◽  
Axial Vibration ◽  
Ansys Software ◽  
Cylinder Axis ◽  
Vibration State ◽  
Rice Stalks

Unbalanced vibration of tangential threshing cylinder increased the grain loss, shortened service life of the cylinder, and resulted in structural resonance during the rice threshing process. In this paper, the vibration amplitude and frequency of tangential threshing cylinder shaft were tested, and the vibration state of tangential threshing cylinder was identified. The restricted and working modalities of tangential threshing cylinder were solved by ANSYS software. Then, by comparing the resonance phenomenon between the inherent constraint frequency and the rotation speed frequency, the shaft vibration under the idle condition of tangential threshing cylinder was tested and analyzed. According to the axial vibration and axial trajectory of the cylinder, the inherent properties and characteristics of unbalanced vibration were revealed. Test results showed that when the tangential threshing cylinder was at idling and no-load state, the amplitude of vibration in the feed direction of straw flow was -0.049~0.060 mm, and the average vibration amplitude was 0.013 mm. As rice flowed along the tangential threshing cylinder, the vibration amplitude slightly increased. The trend and phase of each trajectory were similar, although the amplitude of each trajectory was different. The tangential threshing cylinder axis trajectory was flat oval. Unbalanced vibration was induced by the rice stalks in the concave gap.

Production of High-Performance Composite Concrete Segment and Experimental Investigation of Materials

2010 ◽  
Vol 168-170 ◽  
pp. 1042-1045
Author(s):  
Ying Li Gao ◽  
Bao Guo Ma
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
High Performance ◽  
Concrete Cover ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Volume Deformation ◽  
Volume Stability ◽  
High Performance Composite ◽  
Structure Layer

Tunnel lining concrete segment is the most critical and important structural member of shield tunneling. This investigation designed and produced high-performance composite concrete segment (HCCS). Some key indexes that affect the properties of segment were tested, such as impermeability, volume stability, mechanical property, etc. The results indicated that the impermeability of HCCS concrete cover was excellent and the chloride diffusion coefficient decreased one order of magnitude compared to that of the ordinary segment concrete cover, while the service-life of HCCS increased more than ten-fold. The volume stability of HCCS concrete cover and concrete structure layer were good and the better compatibility in the volume deformation of the whole structure was shown. Furthermore, the mechanical properties of concrete cover and concrete structure layer met the project requirement perfectly, ensuring the higher durability and longer service-life of HCCS effectively.

scholarly journals Enhanced Performance of Fly Ash-Based Supports for Low-Cost Ceramic Membranes with the Addition of Bauxite

Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 711
Author(s):  
Wan Fan ◽  
Dong Zou ◽  
Jingrui Xu ◽  
Xianfu Chen ◽  
Minghui Qiu ◽  
...  
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Bending Strength ◽  
Ceramic Membrane ◽  
Sintering Temperature ◽  
Low Cost ◽  
Pure Water ◽  
Ceramic Membranes ◽  
Mullite Phase ◽  
Optimum Balance

Support is a necessary foundation for ceramic membranes to achieve high performance. Finding the optimum balance between high performance and low cost is still a significant challenge in the fabrication of ceramic supports. In this study, low-cost fly ash-based ceramic supports with enhanced performance were prepared by the addition of bauxite. The pore structure, mechanical strength, and shrinkage of fly ash/bauxite supports could be tuned by optimizing the bauxite content and sintering temperature. When the sintering temperature and bauxite content were controlled at 1300 °C and 40 wt%, respectively, the obtained membrane supports exhibited a high pure water permeance of approximately 5.36 m3·m−2·h−1·bar−1 and a high bending strength of approximately 69.6 MPa. At the same time, the optimized ceramic supports presented a typical mullite phase and excellent resistance to acid and alkali. This work provides a potential route for the preparation of ceramic membrane supports with characteristics of low cost and high performance.

scholarly journals The Effect of Technological Treatments and Loads on the Service Life of Fillet Welds

2020 ◽  
pp. 21-25
Author(s):  
Janusz Lewandowski ◽  
Dariusz Rozumek
Keyword(s):  
Service Life ◽  
Stress Ratio ◽  
Fatigue Cracks ◽  
Constant Stress ◽  
Fillet Welds ◽  
Test Results ◽  
Technological Treatment ◽  
Technological Treatments ◽  
Made In

The paper presents test results concerning the service life of fillet welds made in steel S355. In addition, the article discusses the initiation and growth of fatigue cracks in specimens subjected to bending with torsion. The tests were performed in relation to constant stress ratio R = -1 and 0. The results presented in the article take into account the effect of the technological treatment on the service life of the specimens. The tests revealed longer service life of the specimens not subjected to the technological treatment, both when R = -1 and 0.

Development of Some Performance-Based Material Specifications for High-Performance Concrete Pavement

2003 ◽  
Vol 1834 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Prasada Rao Rangaraju
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Concrete Pavement ◽  
Performance Criteria ◽  
Test Results ◽  
Department Of Transportation ◽  
Performance Specifications ◽  
Concrete Materials ◽  
Practical Feasibility

In collaboration with FHWA, the Minnesota Department of Transportation (Mn/DOT) has successfully completed its first experimental high-performance concrete pavement (HPCP) project under the Testing and Evaluation Program (TE-30). This project is one of the 22 projects funded under the TE-30 Program. With a structural design life of 60 years, this HPCP is unique in that it incorporates significant changes to the existing Mn/DOT specifications on concrete materials. Some of the new materials-related specifications developed as a part of this project are based on performance criteria that influence long-term durability of the pavement structure. The background and considerations for selecting the new performance measures are discussed, and test results are presented that evaluate the practical feasibility of establishing and achieving the performance specifications.

Aerodynamics of High-Performance Wing Sails

1974 ◽  
Vol 11 (03) ◽  
pp. 270-276
Author(s):  
J. Otto Scherer
Keyword(s):  
High Performance ◽  
Water Channel ◽  
Test Results

Some of the primary requirements for the design of wing sails are discussed. In particular, the requirements for maximizing thrust when sailing to windward and tacking downwind are presented. The results of water channel tests on six sail section shapes are also presented. These test results include the data for the double-slotted flapped wing sail designed by David Hubbard for A. F. Di Mauro's IYRU "C" class catamaran Patient Lady II.

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