Key Techniques of Integral Lifting of Steel Tube Arch for Zhuzhou Bridge in Baise

2013 ◽  
Vol 694-697 ◽  
pp. 3040-3044
Author(s):  
Yan Feng Luo
Keyword(s):  
Low Cost ◽  
Steel Tube ◽  
Combined System ◽  
Construction Sequence ◽  
Synchronous System ◽  
Rigid Frame ◽  
Key Techniques

Superstructure of Zhuzhou Bridge in Baise is a combined system with strong beam and weak arch. It is combined by concrete arches of continuous rigid frame-steel tube. The construction sequence is first the beam then arch, finally the temporary pier is demolished to form the combined system. The middle three parts of steel tube arch rib in the middle span were assembled to a large unity, and it was integrally lifted by synchronous system of hoisting jack to reach positive stop. The techniques have the characteristics of fast, safe and low cost.

Nitrogen removal in a combined system: vertical vegetated bed over horizontal flow sand bed

2001 ◽  
Vol 44 (11-12) ◽  
pp. 137-142 ◽  
Author(s):  
S. Kantawanichkul ◽  
P. Neamkam ◽  
R.B.E. Shutes
Keyword(s):  
Loading Rate ◽  
Low Cost ◽  
Oxygen Demand ◽  
Nitrogen Loading ◽  
Horizontal Flow ◽  
Vertical Flow ◽  
Combined System ◽  
Cost Treatment ◽  
Pig Farm ◽  
Farm Wastewater

Pig farm wastewater creates various problems in many areas throughout Thailand. Constructed wetland systems are an appropriate, low cost treatment option for tropical countries such as Thailand. In this study, a combined system (a vertical flow bed planted with Cyperus flabelliformis over a horizontal flow sand bed without plants) was used to treat settled pig farm wastewater . This system is suitable for using in farms where land is limited. The average COD and nitrogen loading rate of the vegetated vertical flow bed were 105 g/m2.d and 11 g/m2.d respectively. The wastewater was fed intermittently at intervals of 4 hours with a hydraulic loading rate of 3.7 cm/d. The recirculation of the effluent increased total nitrogen (TN) removal efficiency from 71% to 85%. The chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) removal efficiencies were 95% and 98%. Nitrification was significant in vertical flow Cyperus bed, and the concentration of nitrate increased by a factor of 140. The horizontal flow sand bed enhanced COD removal and nitrate reduction was 60%. Plant uptake of nitrogen was 1.1 g N/m2.d or dry biomass production was 2.8 kg/m2 over 100 days.

Construction Risk Assessment Research of Continual Rigid Frame Bridge with Concrete-Filled Steel High Piers

2012 ◽  
Vol 193-194 ◽  
pp. 1174-1178
Author(s):  
Xiao Dong Pan ◽  
Wei Jiang ◽  
Bo Qian
Keyword(s):  
Steel Tube ◽  
Bridge Engineering ◽  
Construction Process ◽  
Analytic Hierarchy ◽  
Rigid Frame ◽  
Construction Risk ◽  
Project Construction ◽  
Complex Technology ◽  
Project Life ◽  
Rigid Frame Bridge

Engineering bridge construction is a very complicated system work. The potential risk would occur frequently in the process from construction preparation to completion. The bridgework has fundamental features in huge investment, complex technology, broad engineering, long project life cycle and big impact if an accident happened. Compared to other highway construction process,there are more risks in the process of the bridgework. According to the method of steel tube concrete composite column bridge pier construction on bridge engineering, this thesis identifies the bigger risk factors in the procedure with the analytic hierarchy process. Combined with the technology of the MIDAS/CIVIL and imitating upper structure construction of actual construction process, it quantificationally analyses the construction risk. This could be for the reference to risk analysis on bridge project construction.

scholarly journals Self-consolidating concrete : rheology, fresh properties and structural behaviour

2021 ◽  
Author(s):  
Vasilios Bill Lambros
Keyword(s):  
Load Capacity ◽  
Low Cost ◽  
Peak Load ◽  
Aggregate Size ◽  
Steel Tube ◽  
Reinforced Concrete Beams ◽  
Maximum Aggregate Size ◽  
Fresh Properties ◽  
Structural Behaviour ◽  
Self Consolidating Concrete

Self-consolidating concrete (SCC) is known for its excellent deformability, high resistance to segregation and bleeding and can be obtained by incorporating viscosity modifying agents (VMA). Identifying and proposing a new low-cost VMA, and developing and testing the fresh and mechanical properties of such a concrete are essential. This thesis presents the performance of four new polysaccharide-based VMAs in enhancing the rheological and fresh properties of cement paste, mortar and concrete. An experimental study on the structural properties of two SCC and one normal concrete (NC) mixtures with varying proportions of coarse aggregate content (713-1030 kg/m 3 ) and maximum aggregate size (12 and 19-mm) is presented. Eighteen reinforced concrete beams were tested to study the comparative shear resistance of SCC and NC. Sixteen SCC and NC filled steel tube columns with and without additional steel reinforcement were tested. A design equation for peak load capacity of CFST columns is proposed and validated.

scholarly journals Low Cost with Vibration Controlled Efficient Fused Deposition Modeling

2019 ◽  
Vol 8 (6) ◽  
pp. 1690-1694
Keyword(s):  
Fused Deposition Modeling ◽  
Low Cost ◽  
Fused Deposition Modelling ◽  
3D Printer ◽  
Body Parts ◽  
Fused Deposition ◽  
Rigid Frame ◽  
Innovative System ◽  
Industrial Unit ◽  
Cost Efficient

Fused Deposition Modelling (FDM) is an innovative system that can create necessary items and are significant to generate distinctive styles of articles, in unusual supplies, completely from the uniform system. FDM machine can build fair model everything from stoneware to synthetic dolls, iron machine parts, decorative chocolate cakes or regular human body parts. FDM can supersede conventional factory industrial unit with only machinery, simply like printing press swapped by bottles of ink. Nowadays these machines are available at higher costs and are used only in industrial areas. With technology available and the material used in these machines proposes a system that sparks upon making a low cost-efficient machine and materials by designing a rigid frame for the 3D printer. The result shows low cost 3D printer prototype of FDM machine and the vibration analysis with various speed at various stages for the product outcome

Study on Technique of Induction Cladding Alloy Layer in Steel Tube Outer Wall and Property of Alloy Layer

2011 ◽  
Vol 295-297 ◽  
pp. 203-207 ◽  
Author(s):  
Fan Yu ◽  
Jing Wei Liu ◽  
Le Dong Ren ◽  
De Qiang Wang
Keyword(s):  
Low Cost ◽  
Outer Wall ◽  
Slag Inclusion ◽  
Alloy Layer ◽  
Steel Tube ◽  
Transition Band ◽  
Dendritic Crystal ◽  
Cladding Layer ◽  
Current Technique ◽  
Metallurgical Bonding

This project studied on technique of induction cladding alloy layer in steel tube outer wall and property of alloy layer, briefly introduced the principle of technique, technique assemble and outstanding character, and analyzed the microstructure of prepared cladding layer. Result showed that there existed a clear bright transition band between cladding layer and body, and the metallurgical bonding performed very well. The alloy cladding layer microstructure present as form of eutectic between austenite + carbide (some austenite dendritic crystal can be seen in some zone), this technique is applied for steel tube outer wall strengthening. Compared to the current technique, it could protect environment and had advantage of high combining strengthen, speed and low cost and with no interstice and slag inclusion.

scholarly journals Treatment of Organic Matter and Tetracycline in Water by Using Constructed Wetlands and Photocatalysis

2019 ◽  
Vol 9 (13) ◽  
pp. 2680 ◽  
Author(s):  
Nguyen ◽  
Chao ◽  
Chen
Keyword(s):  
Organic Matter ◽  
Removal Efficiency ◽  
Low Cost ◽  
Oxygen Demand ◽  
Combined System ◽  
Uva Irradiation ◽  
Complete Treatment ◽  
Doc Concentration ◽  
Removal Efficiencies ◽  
Α Al2o3

In this study, the ability of a bench-scale simulated constructed wetland (CW) to remove organic matter (OM) and tetracycline (TC) from water was examined. The performance of CW was evaluated by varying the initial concentrations of the target compounds and the hydraulic retention times (HRTs). Findings showed that OM removal efficiencies were 55.2–80.8%, 28.1–71.9% and 72.1–79.7% for ultraviolet absorbance at 254 nm (UV-254), dissolved organic carbon (DOC) and soluble chemical oxygen demand (sCOD) respectively, under 1 day-HRT, whereas higher initial DOC concentration achieved better removal efficiencies. Changing from 1 day-HRT to 2 day-HRT, the removal efficiency of OMs remained practically unchanged, while that of NH3-N increased considerably, from 61.7% to 73.0%, implying that the removal of ammonia in CW needs a longer time for complete treatment. CW also showed an excellent performance in removing TC, especially in the first two hours of operation through the absorption process. In addition, the findings from this research revealed an improvement in effluent water quality when photocatalysis (TiO2/α-Al2O3, with ultraviolet A (UVA) irradiation) was used as the post-treatment following CW, presented by the increase in removal efficiency of OMs of the combined system compared to that of CW alone. This study points to the possible and promising application of the low-cost water treatment system for dealing with OMs and TC in water.

A low-cost municipal sewage treatment system witha combination of UASB and the “fourth-generation”downflow hanging sponge reactors

2005 ◽  
Vol 52 (1-2) ◽  
pp. 323-329 ◽  
Author(s):  
M. Tandukar ◽  
S. Uemura ◽  
I. Machdar ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
Municipal Wastewater ◽  
Low Cost ◽  
Sewage Treatment ◽  
Pilot Scale ◽  
Treatment System ◽  
Uasb Reactor ◽  
Fourth Generation ◽  
Municipal Sewage ◽  
Combined System ◽  
Successful Operation

This paper presents an evaluation of the process performance of a pilot-scale “fourth generation” downflow hanging sponge (DHS) post-treatment system combined with a UASB pretreatment unit treating municipal wastewater. After the successful operation of the second- and third-generation DHS reactors, the fourth-generation DHS reactor was developed to overcome a few shortcomings of its predecessors. This reactor was designed to further enhance the treatment efficiency and simplify the construction process in real scale, especially for the application in developing countries. Configuration of the reactor was modified to enhance the dissolution of air into the wastewater and to avert the possible clogging of the reactor especially during sudden washout from the UASB reactor. The whole system was operated at a total hydraulic retention time (HRT) of 8 h (UASB: 6 h and DHS: 2 h) for a period of over 600 days.The combined system was able to remove 96% of unfiltered BOD with only 9 mg/L remaining in the final effluent. Likewise, F. coli were removed by 3.45 log with the final count of 103 to 104 MPN/100 ml. Nutrient removal by the system was also satisfactory.

The High-Efficient Low-Cost Wheel-Grinding Technology for CVD Diamond Films

2007 ◽  
Vol 24-25 ◽  
pp. 295-302 ◽  
Author(s):  
Zhu Ji Jin ◽  
Xing Wei Ma ◽  
Ze Wei Yuan
Keyword(s):  
Low Cost ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Chemical Polishing ◽  
High Tech ◽  
Diamond Polishing ◽  
High Efficient ◽  
Promising Perspective ◽  
Key Techniques

CVD diamond films have been used in many high-tech fields with the industrial and scientific developments, while the lagging of the polishing technology for the CVD diamond films has limited their widely applications. This paper presents a high-efficient low-cost wheel-grinding technology for CVD diamond polishing, and the two key techniques of this technology are introduced in detail based on thermo-chemical polishing technology. Furthermore, wheel grinding technology exhibits a promising perspective for the widely application in the diamond films.

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