1,930 research outputs found
Effect of Chloride on Offshore Structure Welding Procedure
The objective of this research was to determine the effect of chloride to the welded
ASTM A516 Grade 70 materials. The used of proper welding procedure may
eliminate the probability of crack occurrences, but there were still cracking happen
in some offshore welding. That was because the failures may occur hours or days
after the welding work completed. The scope of the study was on ASTM A516
Grade 70 steels welded using WPS FSP-HLE-17-49 procedure and exposed under
salt environment according to ASTM G41-90 at 35°C for period of 1 to 5 days. Non
Destructive Examination such dye penetrant and magnetic particle testing were used
to investigate the initial conditions of specimen and the conditions after exposing the
materials under the simulated offshore environment. Metallographic examinations of
the specimen were crucial in this study. The study had shown that the welded
structure using the WPS produced complete welds with no visible surface crack. The
hardness of the weld and the HAZ was 213(HV10) and 224 (HV10) respectively.
There were found to be well below critical hardness value i.e. 300 (HV10) for weld
metal and 248 (HV10) for HAZ, as according to PTS 20.112. There were no surface
cracks found throughout the duration of the study. The study concludes that if the
welding was done in strict compliance with the code and standard, high weld
integrity would be produced
Understorey bird species composition in primary and 10-year-old logged forest at Sungai Lalang Forest Reserve, Semenyih, Selangor
Immediate effects of selective logging on the feeding guild of the understorey insectivorous bird species
Multiresolution Ray Tracing For Point-Based Geometry [QA445. N832 2007 f rb].
Tumpuan utama di dalam tesis ini adalah kajian tentang integrasi teknik berbilang peleraian dengan penyurihan sinar di dalam menjanakan imej objek objek 3D berasas titik.
The primary concern in this thesis is with the incorporation of multiresolutionbased optimization into ray tracing algorithms specially tailored for point-based geometry
Feasibility analysis model for construction of soccer stadiums
This current research aims to study the different stadiums worldwide and to analyze the different aspects controlling them in terms of planning, design and construction. In this regard, there have been radical changes in the stadium projects approach over the last 30 years. In the past, soccer stadiums used to be consisted of only a pitch and a seating area for the fans. However, over the last 30 years, an evolution started to take place in utilizing stadiums as economically beneficial projects. Currently, stadiums have all safety requirements and incorporate the latest technological advances in order to achieve maximum efficiency. Furthermore, studying stadiums from different continents concentrates on the positive and negative aspects of these stadiums including different stadiums worldwide. That is an attempt to reach a viable solution to develop successful stadiums in terms of planning, design and construction. Therefore, the main goal of this study is finding a way to have a safe stadium that can generate profits to its owner plus the prospect of finding different funding options that could be used effectively. In this study, the analysis will focus on cost, safety and profitability of each stadium project. Then, we will begin to implement our own created model for a new stadium to be built in Egypt, or any other country worldwide using the Big Mac Index. We will take into consideration the whole process of establishing a new successful soccer stadium project, starting by setting a vision, planning, design and then construction
Comparison of the 1FT of alkali/surfactant and branched alcohol/surfactant for Surfactant Flooding
Surfactant flooding has been applied commercially for many years, especially in the 1970's
and 1980's. The principle oflowering the interfacial tension to release residual oil trapped
thus giving a higher oil production. The ultimate challenges in using surfactant as the
preferable methods in chemical EOR are the effectiveness of the surfactant and the cost of
using surfactant. Researchers have shown additives (e.g.; Alkaline and Branched Alcohol)
incorporated with surfactant enhanced the effects of surfactant. These additives can also
provide solution to the problems in the reservoir like the effective concentrations of
surfactant needed, level of tolerance of surfactant in high salinity, high hardness and high
temperature reservoirs and preventing the loss into the rock. This project was undertaken to
compare the effects of alkali and branched alcohol on surfactant flooding.
Interfacial tension is one of the important criteria in determining the success of EOR.
Interfacial tension values of the surfactant with additives were measured using Interfacial
Tension Meter (OPMAN 1FT 700). Comparisons were done to show which additives
(alkalis; sodium carbonate and sodium hydroxide or branched alcohold; 2-methyl-lbutanol,
2-methyl-2butanol) were better and at which concentrations (0.1, 0.25, 0.5, 1.0 wt %). At
reservoir condition, pressure ranged between 1 000-1800psi with the temperature of 40-45 °C
was used. Moreover, physical appearance (precipitation) in hard and soft water was also
been observed. Results showed that branched alcohol performed well with surfactant in high
salinity water with no precipitation effect and had a very low interfacial tension down to
O.SmN/m. However, further branching in alcohol did not show much effect on 1FT.
Compared to alkali, some precipitation occurred due to reaction of sodium with hydroxide
and carbonate ions
Breakthrough of Oscillatoria limnetica and microcystin toxins into drinking water treatment plants – examples from the Nile River, Egypt
The presence of cyanobacteria and their toxins (cyanotoxins) in processed drinking water may pose a health risk to humans and animals. The efficiency of conventional drinking water treatment processes (coagulation, flocculation, rapid sand filtration and disinfection) in removing cyanobacteria and cyanotoxins varies across different countries and depends on the composition of cyanobacteria and cyanotoxins prevailing in the water source. Most treatment studies have primarily been on the removal efficiency for unicellular Microcystis spp., with little information about the removal efficiency for filamentous cyanobacteria. This study investigates the efficiency of conventional drinking water treatment processes for the removal of the filamentous cyanobacterium, Oscillatoria limnetica, dominating the source water (Nile River) phytoplankton in seven Egyptian drinking water treatment plants (DWTPs). The study was conducted in May 2013. The filamentous O. limnetica was present at high cell densities (660–1 877 cells/mL) and produced microcystin (MC) cyanotoxin concentrations of up to 877 μg∙g-1, as determined by enzyme-linked immunosorbent assay (ELISA). Results also showed that conventional treatment methods removed most phytoplankton cells, but were ineffective for complete removal of O. limnetica. Furthermore, coagulation led to cell lysis and subsequent microcystin release. Microcystins were not effectively removed and remained at high concentrations (0.37–3.8 μg∙L -1) in final treated water, exceeding the WHO limit of 1 μg∙L-1. This study recommends regular monitoring and proper treatment optimization for removing cyanobacteria and their cyanotoxins in DWTPs using conventional methods.Keywords: cyanobacteria, removal, conventional drinking water treatmen
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