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Full-Text Articles in Civil and Environmental Engineering

An In-Depth Evaluation Of Shear Box Compactor For Hot Mix Asphalt, Isaac Jaime Aguilar Jan 2017

An In-Depth Evaluation Of Shear Box Compactor For Hot Mix Asphalt, Isaac Jaime Aguilar

Open Access Theses & Dissertations

Asphalt pavement is present in each roadway in every town or city today and it is paramount to properly design pavement to efficiently reduce its deterioration. To determine how pavement fails, pavement specimens prepared in the laboratory undergo performance tests which demonstrate the pavements strength and durability. Performance tests require little variability from compacted specimens, and it is critical to have a compaction method which is similar to field compaction and produces homogenous specimens. Currently, laboratory performance test specimens are obtained with the Superpave Gyratory Compactor (SGC). That device has few similarities to the rolling compactor, which performs the actual …


Integrating Manufacturing Geometric Imperfections In The Inelastic Behavior Modeling Of Joints Used In Three-Dimensional Structures, Alfonso Andres Garcia Jan 2017

Integrating Manufacturing Geometric Imperfections In The Inelastic Behavior Modeling Of Joints Used In Three-Dimensional Structures, Alfonso Andres Garcia

Open Access Theses & Dissertations

Three-dimensional structures follow design practices on the common assumption that joints are either rigid, or pinned. However, the non-linear behavior of engagement of the joints is required to be incorporated into the analysis. This research is intended to incorporate manufacturing geometric imperfections into the mechanical analysis of reticulated space structures jointing systems. Imperfect jointing systems deviate from the as-designed models in such a way that the location of the connecting surfaces does not follow the designed interaction path between the component elements. However, current structural analysis methodologies do not consider manufacturing geometric imperfections and often fail to consider the stresses …


Cost-Effective Recovery Of Concentrated Cooling Tower Blowdown Using The Cerro Process, Lindsey Nicole Larson Jan 2017

Cost-Effective Recovery Of Concentrated Cooling Tower Blowdown Using The Cerro Process, Lindsey Nicole Larson

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) process is a seawater-RO unit that can cost-effectively achieve extremely high recoveries from water high in silica, carbonate and sulfate concentrations. This relatively new technology takes advantage of the induction time of potential foulants to recover more water than what is normally achievable with a conventional desalination system. The scope of the project was to evaluate the efficiency of the CERRO process as a pilot study using cooling tower blowdown which varied in water quality parameters daily. It was found that the CERRO pilot could successfully achieve 85% recovery, and the main limitation …


Evaluation Of Mechanical Parameters Of Contaminated Road Base And Railway Ballast, Prajwol Tamrakar Jan 2017

Evaluation Of Mechanical Parameters Of Contaminated Road Base And Railway Ballast, Prajwol Tamrakar

Open Access Theses & Dissertations

This Dissertation comprises two topics in the area of transportation geotechnics that focus on the evaluation of stiffness parameters of contaminated road base and railway ballast. The abstracts of these two studies are provided in the following two paragraphs.

The performance of a flexible pavement depends on the mechanical characteristics of its unbound granular base layer. The mechanical characteristics such as stiffness and deformation resistance depend on many factors such as the material gradation, fines content, moisture content, physical properties of coarse aggregate and more. The base materials are often contaminated by the excessive fines that is caused by improper …


The Former Asarco Demolition Fallout, A Post Study On Lead Soil Concentrations And Environmental Agents Of Redistribution In El Paso, Texas, Stephanie A. Robinson Jan 2017

The Former Asarco Demolition Fallout, A Post Study On Lead Soil Concentrations And Environmental Agents Of Redistribution In El Paso, Texas, Stephanie A. Robinson

Open Access Theses & Dissertations

The former El Paso ASARCO Smelting and Refining Co. operated between 1877 and 1999, the pyrometallurgic activity was estimated to have discharged excess of a 1,000 tons of lead (Pb) into the atmosphere from 1969-71. It was estimated 96 tons of (Pb) were emitted on an annual basis from the standing ore and fluid beds. The Environmental Protection Agency (EPA) determined that lead (Pb) is the heavy metal of the highest concentration within the vicinity of the smelter. After the smelter production ceased, flash flooding common to the southwest, such as the 2006 historic flood, increased transportation of superficial contaminants …


Impact Of Reclaimed Asphalt Pavement And Recycled Asphalt Shingles On Laboratory And Field Performance Of Texas Asphalt Concrete Pavements, Berenice Salaices Gomez Jan 2017

Impact Of Reclaimed Asphalt Pavement And Recycled Asphalt Shingles On Laboratory And Field Performance Of Texas Asphalt Concrete Pavements, Berenice Salaices Gomez

Open Access Theses & Dissertations

The use of recycled materials in Asphalt Concrete (AC) mixes is highly promoted in the transportation industry. Recycled materials minimize the use of virgin materials, reduce the consumption of resources, and cut costs for new construction or rehabilitation projects. The incorporation of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in the AC mixture is promoted as long as equal or improved performance is achieved. The Texas Department of Transportation (TxDOT) is currently placing asphaltic concrete (AC) mixes that are lasting less than their expected performance life when recycled materials are used.

The objective of this Thesis is to …


Modeling The Effects Of Manufacturing Geometric Imperfections In The Buckling Analysis Of Three-Dimensional Structures, Juan Carlos Salcido Jan 2017

Modeling The Effects Of Manufacturing Geometric Imperfections In The Buckling Analysis Of Three-Dimensional Structures, Juan Carlos Salcido

Open Access Theses & Dissertations

Reticulated three-dimensional structures follow design practices based on the common assumption that joints are either rigid, or pinned. However, the actual non-linear behavior of the jointing system interaction is required to be incorporated into the analysis of the structure to accurately predict its buckling stability. Besides, currently, there is a concern on how manufacturing imperfections of these jointing systems affect the global behavior of three-dimensional structures. This Dissertation incorporates and captures the effect that manufacturing geometric imperfections in the fir-tree jointing system produce in the non-linear buckling behavior of three-dimensional structures.

To understand the effect that initial manufacturing imperfections of …


Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte Jan 2017

Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte

Open Access Theses & Dissertations

Air pollution may cause different diseases, such as cardiovascular and lung diseases. Traffic is a major source of mobile emissions causing air pollution. Exhaust emissions from mobile sources (Emissions of Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and Non-exhaust (Brake and Tire) are complex mixtures of gases and dust, including a large number of ultrafine particles, especially in areas with high traffic density. Recent studies have shown high rates of morbidity and mortality in people exposed to these types of emissions because the fine and ultrafine particles can be transported from the respiratory airways to the organs, thus contributing to increase …


Asset Management Support Tools To Assist Agencies In The Development Of Guardrail Preservation Programs, Sandra N. Gutierrez Jan 2017

Asset Management Support Tools To Assist Agencies In The Development Of Guardrail Preservation Programs, Sandra N. Gutierrez

Open Access Theses & Dissertations

The purpose of this Thesis is to develop a Guardrail Asset Management Framework and a Condition-Based Model to assist agencies in the development of guardrail preservation programs. Both of the guardrail asset management tools can be incorporated into an existing asset management program to assist agencies in utilizing guardrail inventory to forecast key asset management parameters such as the guardrail condition, funds necessary for maintenance and repair, backlogged funding, guardrail system value, and the guardrail sustainability ratio. Each of these parameters is described and determined for a case study involving six scenarios modeling funding and maintenance constraints that can arise …


Characterization Of Subgrade Resilient Modulus For Mepdg And The Effects On Pavement Rutting, Md Mostaqur Rahman Jan 2017

Characterization Of Subgrade Resilient Modulus For Mepdg And The Effects On Pavement Rutting, Md Mostaqur Rahman

Theses and Dissertations

In 2008, the American Association of State Highway and Transportation Officials (AASHTO) released a modified pavement design method (i.e., the Mechanistic Empirical Pavement Design Guide (MEPDG)) based on Long Term Pavement Performance (LTPP) data from all over the United States. The MEPDG default design parameters developed from the LTPP database are expected to be significantly different than those for South Carolina material, traffic and weather conditions, thus the default design parameters may not be accurate for South Carolina. Therefore, the new pavement design method should be calibrated for South Carolina conditions by performing MEPDG local calibration.

Different input variables should …


Performance Assessment Of Hsrm Concrete Ties Through Finite Element Model Simulations, Adam I. Zeitouni Jan 2017

Performance Assessment Of Hsrm Concrete Ties Through Finite Element Model Simulations, Adam I. Zeitouni

Theses and Dissertations

Concrete ties have become a promising alternative to timber ties for freight lines with increased curvature, high annual traffic, and large axle loads. They are also widely adopted in passenger lines. High strength (HS) concrete is the material of choice in the fabrication of prestressed concrete railroad ties. The higher strength of the concrete is directly related to higher values of the Elastic Modulus, thus increasing the rigidity of the material. The combination of increased strength, rigidity, and the material brittleness may lead to the development of high amplitude stresses with high gradients, which appears to be a common underlying …


Intermodal Network Design And Expansion For Freight Transportation, Fateme Fotuhiardakani Jan 2017

Intermodal Network Design And Expansion For Freight Transportation, Fateme Fotuhiardakani

Theses and Dissertations

Over the last 50 years, international trade has grown considerably, and this growth has strained the global supply chains and their underlying support infrastructures. Consequently, shippers and receivers have to look for more efficient ways to transport their goods. In recent years, intermodal transport is becoming an increasingly attractive alternative to shippers, and this trend is likely to continue as governmental agencies are considering policies to induce a freight modal shift from road to intermodal to alleviate highway congestion and emissions. Intermodal freight transport involves using more than one mode, and thus, it is a more complex transport process. The …


Evaluation Of Red Rrfb Implementation At Freeway Off-Ramps And Its Effectiveness On Alleviating Wrong-Way Driving, Seckin Ozkul, Pei-Sung Lin Jan 2017

Evaluation Of Red Rrfb Implementation At Freeway Off-Ramps And Its Effectiveness On Alleviating Wrong-Way Driving, Seckin Ozkul, Pei-Sung Lin

CUTR Faculty Journal Publications

Wrong-way crashes are a major cause for safety concern along freeways and limited access facilities. This study investigated three different aspects of the use of Rectangular Rapid Flashing Beacons (RRFBs): 1) different settings of red RRFBs and their perceived effectiveness on reducing wrong-way driving based on a public opinion survey, 2) the effect of active red RRFBs on the behavior of drivers traveling on adjacent roadways via a before-and-after study, and 3) the effectiveness of red RRFBs on alleviating wrong-way driving on freeway off-ramps by analyzing the percentage of vehicles turning back after observing the red RRFB activation. Based on …


Improvement Assessment Of Bus Serviceability By Proposing Route Revision, Shahrzad Ainkeshavarzi, Hamed Soleimani Jan 2017

Improvement Assessment Of Bus Serviceability By Proposing Route Revision, Shahrzad Ainkeshavarzi, Hamed Soleimani

CUTR Faculty Journal Publications

Public transit is an essential part of a city’s transportation. An efficient transit system makes a city more sustainable by reducing the number of single occupancy vehicles leading to a reduction in emissions, energy consumption and less congestion on streets. Public serviceability is an important indicator to indicate how good a transit route is determined; however, it could change during the years since population density is variable. This study is intended to do a comparison between serviceability of a bus line in Memphis, Tennessee for one zip code area to point out the necessity of considering route revising in short-term …


Exploring Factors Contributing To Lane Changes During Left Turns On Quadruple Left-Turn Lanes At Signalized Intersections, Fulu Wei, Zhenyu Wang, Jian Lu Jan 2017

Exploring Factors Contributing To Lane Changes During Left Turns On Quadruple Left-Turn Lanes At Signalized Intersections, Fulu Wei, Zhenyu Wang, Jian Lu

CUTR Faculty Journal Publications

Quadruple left-turn lanes are employed gradually at some major intersections in Jilin, China. At these intersections, frequent lane changes during left turns of vehicles can lead to vastly disordered traffic operations. In this study, the factors contributing to lane changes during left turn behaviors at quadruple left-turn lane intersections were interpreted based on a field survey. In total, data on 192 green intervals and 550 individual lane-change behaviors were collected in Changchun, Jilin Province. A lane-changing rate model was established to predict the rate of lane changes during left turns. In addition, an interval selection model was built to estimate …


Influence Of Crumbed Para Rubber Modifier In Aggregate Blend On Deformation Resistance Properties Of Hot Mix Asphalt, Hatthaphone Silimanotham Jan 2017

Influence Of Crumbed Para Rubber Modifier In Aggregate Blend On Deformation Resistance Properties Of Hot Mix Asphalt, Hatthaphone Silimanotham

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the influence of crumbed para rubber which is added into a portion of aggregate in hot mix asphalt (HMA) during the batch mixing process or called "Dry Process". The dry process has an advantage on its simplicity of quality inspection and less modification in the hot mix plant production process. This study has investigated the effects of adding crumbed para rubber particles on the engineering properties related to permanent deformation resistance of asphalt concrete. In this study, the asphalt mixture is prepared via Marshall Mix design, which contained with limestone and asphalt cement of Pen 60/70 at …


Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira Jan 2017

Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multi-layered nano-scale structures have been found in a wide range of applications these days. Since the surface energy effect is presented at the nano-scale level, a novel calculation scheme is required to accurately capture the mechanical behaviors of such structures. In this study, a solution scheme for analysis of a multi-layered elastic medium with influence of surface energy effects subjected to axisymmetric loading by adopting Gurtin-Murdoch surface elasticity theory is presented. The standard Love's representation and Hankel integral transform are employed to derive the general solutions, and the obtained solutions are employed in the determination of the stiffness matrix for …


Factors Affecting Building Damage And People's Preparedness For Earthquake In Chiang Rai, Narongdej Intaratchaiyakit Jan 2017

Factors Affecting Building Damage And People's Preparedness For Earthquake In Chiang Rai, Narongdej Intaratchaiyakit

Chulalongkorn University Theses and Dissertations (Chula ETD)

On May 5, 2014, an earthquake with a magnitude of 6.3 on the Richter scale occurred in Chiang Rai, Thailand. This earthquake was the strongest earthquake in Thailand at the Mae Lao District region. It also caused building damage and casualties. In this research, 277 participants living in village no.2 and village no.7 of Dong Mada, a sub-district at Mae Lao district in Chiang Rai, were selected. A questionnaire was used to interview these participants, and the data were analyzed by Chi-square, Fisher's exact test, a Mann-Whitney U test, and a Kruskal-Wallis test. The objective of this study was to …


Weakly Singular Boundary Integral Equation Method For Analysis Of Generalized T-Stresses Of Cracks In 3d Coupled-Field Media, Naruethep Sukulthanasorn Jan 2017

Weakly Singular Boundary Integral Equation Method For Analysis Of Generalized T-Stresses Of Cracks In 3d Coupled-Field Media, Naruethep Sukulthanasorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents the development of a weakly singular boundary integral equation method for the analysis of the generalized T-stress of isolated cracks embedded in a coupled-field whole space. A pair of weak-form integral equations, one for crack-face generalized traction and the other for the gradient of the crack-face generalized displacement, is established in a general framework allowing various types of materials including elastic, piezoelectric, piezomagnetic and piezoelectromagnetic solids, general crack geometry and loading conditions to be handled in a unified fashion. In addition, the final governing integral equations contain only weakly singular kernels and this, as a result, renders …


An Application Of Geosynthetic Cementitious Composite Mat For Slope Stabilization, Phong Tan Ngo Jan 2017

An Application Of Geosynthetic Cementitious Composite Mat For Slope Stabilization, Phong Tan Ngo

Chulalongkorn University Theses and Dissertations (Chula ETD)

In recent years, soil erosion and slope instability caused by seepage and rainfall are major problems, especially in the mountain area. Many research studies have focused on finding a new technology or material to stabilize the soil slope. In this study, a novel material called geosynthetic cementitious composite mat (GCCM) is selected to study its performance on soil slope stabilization. A series of 1-g physical model tests and numerical simulation (Plaxis 2D) on sandy soil slopes stabilized with and without GCCM are performed under seepage condition. In addition, centrifuge modeling of soil slopes is performed under 25-g in seepage and …


Quantification Of Seismic Performance Factors For Circular Concrete-Filled Steel Tube Diagrid Structures, Nattanai Kuangmia Jan 2017

Quantification Of Seismic Performance Factors For Circular Concrete-Filled Steel Tube Diagrid Structures, Nattanai Kuangmia

Chulalongkorn University Theses and Dissertations (Chula ETD)

In 21st century, diagrid structures become more popular lateral force-resisting systems for high-rise buildings world-wide. It consists of several grids of diagonal members on building perimeter serving as both lateral bracing and vertical-load carrying members. Since the diagrid structure is a relatively new type of lateral force-resisting system, current building codes do not explicitly provide the seismic performance factors (SPFs) for this system to use in design process. This thesis aims to determine appropriate SPFs for the diagrid structure incorporating circular concrete-filled steel tube to enable structural engineers to design this system according to seismic performance expected in building codes. …


Analysis Of Near Interface Cracks By Weakly Singular Boundary Integral Equation Method, Pisit Watanavit Jan 2017

Analysis Of Near Interface Cracks By Weakly Singular Boundary Integral Equation Method, Pisit Watanavit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents a weakly singular boundary integral equation method for analysis of sub-interface cracks in a three-dimensional, linearly elastic, multi-material domain. The formulation is established in a general framework allowing finite bodies, general material anisotropy and loading conditions, arbitrarily shaped cracks, and curved material interface to be treated. A system of integral equations governing the unknown data on the boundary, the crack surface and the material interface are established using a pair of weakly singular, weak-form displacement and traction integral equations and the continuity along the material interface. A symmetric Galerkin boundary element method together with the standard finite …


Contact Problems With Surface Stress Effects, Supakorn Tirapat Jan 2017

Contact Problems With Surface Stress Effects, Supakorn Tirapat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation presents a theoretical study of contact problems with consideration of surface energy effects by adopting a complete Gurtin-Murdoch theory of surface elasticity. The fundamental solution of a layered elastic half-space subjected to axisymmetric surface loading is obtained by using Love's representation and the Hankel integral transform. The analytical solutions for both displacement and stress fields are expressed in terms of semi-infinite integrals, which can be accurately evaluated by employing a numerical quadrature scheme. The obtained solutions are employed as the required influence functions in the investigation of axisymmetric indentation on a layered elastic medium with frictionless and adhesive …


Seismic Effects Of Cornice Projection In Masonry-Infill Reinforced Concrete Buildings In Bhutan, Tek Nath Kararia Jan 2017

Seismic Effects Of Cornice Projection In Masonry-Infill Reinforced Concrete Buildings In Bhutan, Tek Nath Kararia

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bhutan is located in utmost active seismic zone in the belt of the Himalayan region. However, there is a prevailing architectural requirement of cornice projections away from the perimeter columns at each floor proportional to the floor level to increase floor area and retain Bhutanese architectural style. This irregular projection with thick solid brick walls resting at the edge of cantilever projection affects the structural response during a strong earthquake. To date, there is not adequate investigation on the effects of such cornice projection on seismic performance of buildings. In this study, Nonlinear Response History Analysis (NLRHA) using vertical ground …


Life-Cycle Reliability Assessment Of Existing Rc Bridge Structures Under Multiple Hazards Using Inspection Data, Thanapol Yanweerasak Jan 2017

Life-Cycle Reliability Assessment Of Existing Rc Bridge Structures Under Multiple Hazards Using Inspection Data, Thanapol Yanweerasak

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study presented a novel methodology to estimate the life-cycle reliability of existing reinforced concrete (RC) corroded bridges under multiple hazards. The life-cycle reliability of a bridge girder under traffic load and airborne chloride hazards was compared with that of a bridge pier under seismic ground motion and airborne chloride hazards. When predicting the life-cycle reliability of existing RC corroded bridges, inspection results could be used to estimate the current material corrosion level. Random variables associated with the estimation of time-variant steel weight loss will be updated to be consistent with the given inspection results by using Sequential Monte Carlo …


Performance And Internal Environment Of Partial Nitrification-Entrapped Cells Under Changes In Cell-To-Matrix Ratio And Substrate Concentrations, Pattaraporn Kunapongkiti Jan 2017

Performance And Internal Environment Of Partial Nitrification-Entrapped Cells Under Changes In Cell-To-Matrix Ratio And Substrate Concentrations, Pattaraporn Kunapongkiti

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, partial nitrification performance was investigated in entrapped cell-based reactors prepared using phosphorylated polyvinyl alcohol gel (PPVA) and operated using oxygen limiting strategy. The study was divided into three main parts: 1) to investigate the community of nitrite-oxidizing bacteria (NOB) in the reactors operated at different bulk dissolved oxygen (DO) concentrations, 2) to investigate the effect of cell-to-matrix ratio (1% and 4%) on partial nitrification performance of the entrapped-cell-based reactors and to observe internal environment, microbial community, and microbial localization within the gel matrix during long-term operation of the reactors, and 3) to study effect of ammonia and …


Roles Of Dissimilatory Nitrate Reduction To Ammonium In Biological Nitrogen Removal System, Pokchat Chutivisut Jan 2017

Roles Of Dissimilatory Nitrate Reduction To Ammonium In Biological Nitrogen Removal System, Pokchat Chutivisut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biological nitrogen removal system is a wastewater treatment process that normally utilizes nitrification-denitrification to convert nitrogen wastes to unharmful gaseous products. However, apart from these two pathways, dissimilatory nitrate reduction to ammonium (DNRA) can also compete with denitrification for nitrate and yield ammonium waste as the end product. The aim of this research is to extend knowledge on the DNRA pathway, including the study on its occurrence and microorganisms responsible for the process. To observe the presence of DNRA, microbial sludge from aquacultures which utilized biological nitrogen removal processes was applied to examine the pathway of DNRA in these systems. …


Development Of Novel Electrocoagulation Reactor (Ecr) For Turbidity Removal And Decolorization From Textile Industry Wastewater, Penghour Hong Jan 2017

Development Of Novel Electrocoagulation Reactor (Ecr) For Turbidity Removal And Decolorization From Textile Industry Wastewater, Penghour Hong

Chulalongkorn University Theses and Dissertations (Chula ETD)

High concentration of dyes together with turbidity were frequently found in the effluents of textile industry wastewater, which are the toxic substances. To remove these contaminants, the combination between electrocoagulation process (EC) and separation has been proposed in this study. The objective of this present work is to design and evaluate the new electrocoagulation reactor (ECR) for treating dye and turbidity from synthetic textile wastewater. The optimization of electrode configuration and design parameter were examined with the batch column reactor for containing 4 liters of wastewater. The result showed that monopolar arrangement within the inner gap 1.5 cm and current …


Study Of Gas-Liquid Absorption In Terms Of Bubble-Fluid Hydrodynamic And Mass Transfer Parameter: Liquid Phase And Gas Phase, Prajak Sastaravet Jan 2017

Study Of Gas-Liquid Absorption In Terms Of Bubble-Fluid Hydrodynamic And Mass Transfer Parameter: Liquid Phase And Gas Phase, Prajak Sastaravet

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research focus on study the effect of continuous system on the bubble hydrodynamic and mass transfer parameters (Qg, QL, DBd, UBd a, kL and kLa). The experiment were set up in a cylindrical acrylic column with 0.15 m inside diameter and 1 m in height. ILALR was setup an acrylic plate for liquid recirculation. Moreover, mass transfer determination, liquid phase was removed dissolved oxygen by using sodium sulphite (Na2SO3). The bubble hydrodynamic mechanisms are investigated by the high speed camera (100 images/sec) and image analysis program is used to determine the bubble hydrodynamic parameters. The bubbles are generated by …


การบริหารจัดการระบบอ่างเก็บน้ำภายใต้เงื่อนไขการพัฒนาระบบเศรษฐกิจในลุ่มน้ำแม่กลอง, เพ็ญนภา พีรวงศ์สกุล Jan 2017

การบริหารจัดการระบบอ่างเก็บน้ำภายใต้เงื่อนไขการพัฒนาระบบเศรษฐกิจในลุ่มน้ำแม่กลอง, เพ็ญนภา พีรวงศ์สกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ลุ่มน้ำแม่กลองเป็นลุ่มน้ำที่สำคัญในภาคตะวันตกของประเทศไทย มีเขื่อนขนาดใหญ่วางขนานกันจำนวน 2 เขื่อน ได้แก่ เขื่อนศรีนครินทร์ และเขื่อนวชิราลงกรณ โดยทางด้านล่างมีเขื่อนทดน้ำอีกจำนวน 2 เขื่อน ได้แก่ เขื่อนท่าทุ่งนา และเขื่อนแม่กลอง สามารถผลิตกระแสไฟฟ้าเพื่อส่งเข้าระบบในช่วงการใช้ไฟฟ้าสูงสุดของภาคกลาง และภาคตะวันตกได้อย่างดี โดยในปัจจุบันพบว่าในปีน้ำปกติลุ่มน้ำแม่กลองมีปริมาณน้ำมากกว่าความต้องการใช้น้ำ สามารถผันน้ำเข้าช่วยเหลือโครงการชลประทานบริเวณลุ่มน้ำท่าจีน ผันน้ำเพื่อผลิตน้ำประปาที่โรงผลิตน้ำมหาสวัสดิ์ และผันน้ำเพื่อช่วยผลักดันน้ำเค็มทางตอนล่างของลุ่มน้ำ แต่ในปีน้ำน้อยพบว่าลุ่มน้ำแม่กลองมีการขาดแคลนน้ำในลุ่มน้ำเป็นจำนวนมาก โดยเฉพาะภาคเกษตรกรรม ขาดแคลนน้ำผลักดันน้ำเค็มท้ายลุ่ม และรวมถึงปัญหาปริมาณน้ำในเขื่อนต่ำจนไม่สามารถผลิตกระแสไฟฟ้าได้ ในปัจจุบันเขื่อนทั้ง 4 เขื่อนในโครงการพัฒนาแหล่งน้ำในลุ่มน้ำแม่กลองนั้น มีการบริหารจัดการน้ำที่เป็นอิสระต่อกัน ทั้งที่อ่างเก็บน้ำเหล่านั้นเชื่อมต่อกันด้วยแม่น้ำแควใหญ่ และแม่น้ำแควน้อย ซึ่งสามารถบริหารจัดการน้ำร่วมกันเพื่อให้ได้ประโยชน์สูงสุดภายใต้ข้อจำกัดที่มี วัตถุประสงค์ของการศึกษานี้คือการพัฒนาแบบจำลองการบริหารจัดการระบบอ่างเก็บน้ำ (multi - reservoir) โดยการหาแนวทางการบริหารจัดการน้ำที่เหมาะสมกับเป้าหมาย (objective function) ภายใต้เงื่อนไขการพัฒนาเศรษฐกิจของลุ่มน้ำ ในการวิจัยนี้ได้ศึกษาความสัมพันธ์ความสัมพันธ์ระหว่างตารางปัจจัยการผลิตและผลผลิต (Input - Output Table) และความต้องการใช้น้ำ ของ 3 ภาคส่วนเศรษฐกิจ ได้แก่ ภาคส่วนเกษตรกรรม ภาคส่วนอุตสาหกรรม และภาคส่วนบริการ ซึ่งเป็นวิธีการใหม่ในการพิจารณามูลค่าของน้ำ สามารถหาผลประโยชน์ทั้งทางตรง ทางอ้อม และกิจกรรมในห่วงโซ่อุปทานอุปสงค์ของระบบเศรษฐกิจตามความต้องการใช้น้ำของแต่ละภาคส่วนได้ โดยแบบจำลองของระบบอ่างเก็บน้ำลุ่มน้ำแม่กลองเป็นปัญหาแบบไม่เป็นเชิงเส้นจํานวนผสม (MINLP) การศึกษานี้ได้พัฒนาแบบจำลองการบริหารจัดการระบบอ่างเก็บน้ำในโปรแกรม GAMS ใช้โปรแกรมแก้ปัญหาสำร็จรูป BONMIN โดยจะพิจารณาการบริหารจัดการน้ำในปี พ.ศ. 2556 - 2557 ซึ่งเป็นปีน้ำปกติ และน้ำน้อยตามลำดับ มีสมการเป้าหมาย (objective function) ที่พิจารณาผลประโยชน์ทางเศรษฐศาสตร์ของน้ำที่ส่งไปให้ใช้ประโยชน์ดังนี้ น้ำเพื่อการเกษตร น้ำเพื่อการประปาโรงผลิตน้ำมหาสวัสดิ์ น้ำเพื่อภาคอุตสาหกรรมในลุ่มน้ำ น้ำเพื่อภาคบริการในลุ่มน้ำ และพลังงานไฟฟ้าจากโรงไฟฟ้าพลังงานน้ำจากเขื่อนที่พิจารณา จากการศึกษาพบว่าการบริหารจัดการอ่างเก็บน้ำร่วมกันสามารถลดการขาดน้ำของภาคเกษตรได้ถึงร้อยละ 80 สามารถผลิตไฟฟ้าจากพลังงานน้ำได้มากขึ้นร้อยละ 0.70 และสามารถเพิ่มผลประโยชน์ทางเศรษฐศาสตร์เมื่อเทียบกับการบริหารจัดการจริงได้ถึงร้อยละ 10.10 ในปีน้ำปกติ ส่วนในปีน้ำน้อยสามารถลดการขาดน้ำของภาคเกษตรได้ถึงร้อยละ 58.56 สามารถผลิตไฟฟ้าจากพลังงานน้ำได้มากขึ้นร้อยละ 16.15 และสามารถเพิ่มผลประโยชน์ทางเศรษฐศาสตร์ได้ถึงร้อยละ 4.36