Experimental Study on Motion Responses of a Damaged Semi-Submersible for Head Sea and Beam Sea Directions of Incident Waves

Vol. 6  Issue 1
Year: 2016
Issue: Dec-Feb
Title: Experimental Study on Motion Responses of a Damaged Semi-Submersible for Head Sea and Beam Sea Directions of Incident Waves
Author Name: Sayed Mohammadmehdi Jamal and Keyvan Sadeghi
Synopsis:

In recent years, due to the reduction of oil resources, both on lands and in shallow waters, exploration and extraction of oil resources are played in deeper waters. Therefore, the need for appropriate structures suitable for deep waters is obvious. The semi-submersible platform is a specific type of such platforms which is used in deep waters. These platforms are utilized for different purposes such as drilling, exploration, extraction, loading and off-loading of petroleum products under the influence of external forces caused by wind, waves, current, etc. True understanding of the dynamical behavior of the semi-submersible platform in damaged condition can help designers to reduce the environmental hazards. Platform structural damage can be accompanied with the entry of water in the reservoirs of platforms which will lead to the change in platform stability and excessive increase in the platform movements. In this research, the AMIRKABIR semi-submersible platform is modeled in the Marine Engineering laboratory of the “Sharif University of Technology”. The model scale was 1:143 and the environmental conditions of the Caspian Sea were considered the amount of water entering one of the pontoon reservoirs was set to follow that similarity scales. The model was installed in the flume tank using a spread mooring system. For the environmental conditions of the Caspian Sea, the platform was tested under both head and beam sea directions. The results of the conducted tests are represented by platform motion Response Amplitude Operators (RAOs).

Black-Spot Identification Using Accident Severity Approach for Cyberabad Region of Hyderabad City - A Case Study

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Black-Spot Identification Using Accident Severity Approach for Cyberabad Region of Hyderabad City - A Case Study
Author Name: A. Sharath Goud,A.Ramesh and M.Kumar
Synopsis:

The place where the traffic accident percentages are higher is called as black spot location. The most common assumption for a black spot location is that, there should be any road environmental or geometric issues resulting in the repetition of accidents. Many countries are facing a huge economical loss under road accidents. India is also one among them. In our country, traffic behavior is heterogeneous in nature and this result in higher rate of road accidents. Because of these critical issues, many improvement techniques are adopted for identification of black spots and evaluating them for the cause of road accidents. Few of these techniques include Accident Frequency method, Accident Rate method, Accident Severity method and Rate Quality Control method.

In this context, an attempt is made to identify black spot locations in cyberabad region of Hyderabad city. Road accident data for a three year period from 2011 to 2013 was collected through respective police station limits of Cyberabad region in Hyderabad city. Identification of black spot was carried through Accident Severity method and ranking was provided for the hazardous accident prone locations using Accident Severity and Critical Severity. Based on the ranking Shamshabad, Petbasheerabad and Rajendranagar were categorized as the highest hazardous rate of accident zones in Cyberabad region. From visual inspection survey and accident data collection, it infers that night time accidents were predominant in accident severity. Over speeding, high occupancy vehicles and night visibility are few causes for more number of accidents in the black-spot locations.

Air Quality Modeling of Non Radioactive Pollutant Emissions from Uranium Mine in a Complex Terrain Using WRF-CALPUFF Model in India - A Case Study

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Air Quality Modeling of Non Radioactive Pollutant Emissions from Uranium Mine in a Complex Terrain Using WRF-CALPUFF Model in India - A Case Study
Author Name: Neela Priya Eruvaram, Satyanarayana. S.V and Rajesh Lakshmi Narayana
Synopsis:

Monitoring and reporting of air pollutants released from mining activities is a mandatory routine practiced all over the world. Air quality modeling was performed using WRF-CALPUFF model to predict dispersion of the emissions from mining operations. PM2.5 and PM10 emissions were observed continuously using high volume air samplers at two ambient monitoring locations (AML-1&AML-2) near Tummalapalle Uranium mine in Y.S.R. Kadapa district, Andhra Pradesh, India. Prime concern was to assess current possible discharge of PM10 , PM2.5 and to predict potential emission of particulate matter, SO2 , NOx and airborne dust containing uranium into the atmosphere from mine. Measured concentrations of PM10and PM2.5 from monitoring locations were compared with CALPUFF model predictions. Four statistical indicators have been computed to determine the models' ability to simulate observations. Statistical analysis indicated that, California Puff (CALPUFF) model has a tendency to under predict and the overall model's performance for two monitoring stations (AML-1&AML-2) was found to be good for PM10 when compared with PM2.5 (at AML-2 some statistical values were beyond the model acceptance range). The index of agreement varied from 0.39 to 0.43 and the total NMSE ranged from 0.08 to 8.36. The average 24hr peak concentrations of CALPUFF estimated pollutants (PM, SOx , NOx ) including uranium containing dusts were well within the Air Quality Standards (NAAQS and CPCB).

Towards Achieving Millennium Development Goals Number 7: A Case of Water Supply Challenges in Oyo State of Nigeria

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Towards Achieving Millennium Development Goals Number 7: A Case of Water Supply Challenges in Oyo State of Nigeria
Author Name: Fatile M.R and Oyegoke S.O
Synopsis:

The purpose of this study is to examine the water supply challenges in Oyo state and to provide adequate suggestions that will enable the state to meet up with the Millennium Development Goal. A thorough investigation was carried out through a review of existing literatures having the same motive as the author. Data were collected from reliable officials so as to establish the fact that, Oyo state inhabitants are facing the problem of insufficient supply of water. The study revealed that the population of Oyo state will continue to increase at the rate of 3.35% population growth. Result of the data collected showed that, the population of Oyo State in 2006 was 5,419,327 whereas the projected population at the end of 2015 is estimated to be 7,290,200. The total output of the nine water supply schemes in the state is 246,302,000 litres daily. However, the millennium development goal set a standard daily water need per person within the range of 50 to 100 litre. 100 litres per person per day was adopted for this study which was multiplied by the projected population to determine the daily water consumption of Oyo state which will rise to 729,020,000 litres daily by the end of 2015. Based on this fact, it was observed that the state will experience short fall of 482,718,000 litres daily by the end of 2015. Having established that there is water supply challenges in Oyo state, the authors recommended that, the state government should upgrade the existing water schemes in order to meet water requirement of the state.

Determination of Water Retention and Unsaturated Hydraulic Conductivity of Brahmaputra Sand

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Determination of Water Retention and Unsaturated Hydraulic Conductivity of Brahmaputra Sand
Author Name: Malaya C and Sreedeep S
Synopsis:

Unsaturated soils with hydraulic properties such as water retention and hydraulic conductivity are considered to be the most crucial parameters for modeling flow process in unsaturated soils. Experimental determination of unsaturated hydraulic conductivity (ku ) is a challenging task and it requires a costly and skilled experimentation. Therefore, the normal practice is to estimate ku from water retention characteristics. Water Retention Characteristic (designated as WRC) includes the development of a graphical relationship between suction and water content (gravimetric or volumetric). This indicates that the accuracy of ku is very much dependent on the unambiguous determination of WRC. In this study, a tensiometer and volumetric water content probe have been used to measure soil suction and volumetric water content, respectively of a local sand by using two different measurement procedures. The ku of the soil has been estimated based on the WRC obtained. The main purpose of this investigation is to understand the extent of influence of different WRC measurement procedures on kuestimation. The study indicates that the measurement procedures have moderate influence on uniqueness of WRC of Brahmaputra sand and hence the estimated ku.

Behavior Aspects of Copper Slag Admixed Concrete Subjected to Destructive and Non-Destructive Tests

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Behavior Aspects of Copper Slag Admixed Concrete Subjected to Destructive and Non-Destructive Tests
Author Name: Binaya Patnaik. G and Seshadri Sekhar. T
Synopsis:

Natural Sand is a common form of fine aggregate used in the preparation of concrete. However, due to rapid urbanization and large scale depletion of river bed, natural sand has become very expensive. Many non-conventional resources such as Stone Dust, Carbonate Sand, Fly ash, Copper Slag etc. with larger % of Silica (SiO ) have been tried out as an alternative to 2 river sand as fine aggregate in preparation of concrete. Copper Slag which is an industrial waste in the metal smelting process of copper production has shown promising result to be used as an alternative to sand in preparation of concrete. The use of copper slag in construction activity will also resolve the issues of disposing the industrial waste which is a major concern these days. This paper studies the behavioral aspects of Copper slag admixed concrete while it is subjected to both destructive and non destructive tests. It proposes to study the behavioral aspects by adding Crimped steel fibres with varying percentages from 0 to 1.5 in the mixes of M 20 and M 30 .

Utilization of Discarded Pet Bottle Granules as Fine Aggregate in Concrete - A Feasibility Study

Vol. 5  Issue 4
Year: 2015
Issue: Sep-Nov
Title: Utilization of Discarded Pet Bottle Granules as Fine Aggregate in Concrete - A Feasibility Study
Author Name: T. Sekar 
Synopsis:

An experimental investigation has been carried out to study the feasibility of discarded Poly Ethylene Terephthalate (PET) bottle granules as fine aggregate in concrete. Mechanical strength and temperature studies have been conducted on 162 numbers of standard concrete specimens which are made with or without waste PET bottle granules as per relevant Indian standard code procedure. The waste PET bottle granules have been used as a substituting material in lieu of conventional fine aggregate in concrete ranging from 0 to 100% at an interval of 10%. The mechanical strength studied includes compressive strength, tensile strength and flexural strength at the age of 28 days. Temperature studies have  been conducted on concrete cube specimens by exposing it to series of peak temperatures such as 300o C, 600o C and 900o C, to evaluate residual compressive strength. It has been found from test results that substitution of discarded PET bottle granules in place of conventional fine aggregate in concrete reduces compressive strength, tensile strength, flexural strength, residual compressive strength and density of concrete markedly, and the reduction in strength and density increases with increase in PET bottle granules content in concrete. Also, reduction in residual compressive strength increases with increase in temperature for specimens made with and without PET bottle granules in concrete.