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1
Deng, Kai. "Dynamic response of certain types of highway bridges to moving vehicles." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37062.pdf.
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Sinkevičiūtė, Aida. "Lietuvos tiltų statybos raida ir architektūros bruožai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120621_111030-14793.
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Darbe, remiantis archyvine ir ikonografine medžiaga atskleidžiama Lietuvos tiltų statybos raida ir jų architektūros bruožai. Darbe analizuojamas tiltų ir aplinkos santykis, tiltų tipologija, išryškinami reikšmingiausi tiltai - kultūros paveldo objektai. Lietuvos tiltų ikonografija nagrinėjama dokumentiškumo aspektu, remiantis senaisiais atvaizdais ir rašytiniais šaltiniais. Iki šiol Lietuvos tiltų istorija tyrinėta labai fragmentiškai. Tiltai - sudėtingi specifiniai inžineriniai statiniai. Visa tiltų statybos istorija byloja apie kiekvieno laikotarpio kultūrą, statybos meną, mokslo ir technikos pažangą. Šie statiniai turi istorinę, techninę, architektūrinę vertes ir yra neatsiejamas kelių plėtros atributas. Mūsų dienomis, kai kelių ir tiltų tinklas yra labai platus, tiltai tapo tarsi nepastebimi ir jų svarba šiandien iki galo nebesuvokiama. Inžinieriai visais laikais siekė statyti tvirtus, ilgaamžius ir grakščius tiltus. Dabartiniame pasaulyje vyrauja tradicija, kur tiltų architektūrai suteikiamas ypač svarbus vaidmuo. Darbe pristatomi senieji Lietuvos tiltai (XIII-XVIII a.); apžvelgiami ankstyvieji geležinkelių tiltai; aptariama tiltų statyba bei jų architektūriniai bruožai XX a. (nepriklausomoje Lietuvoje, Sovietmečiu bei dabartiniais laikais).The final paper presents a review of the development of bridge construction technology and architectural design. The review is based on the materials obtained from historical archives and iconographic resources. The paper analyzes the impact of bridges on the environment and their typology, and highlights the most important bridges which are the objects of cultural heritage. The iconography of Lithuanian bridges is analyzed in terms of documentation. The study is based on the historical images and literature sources. Until the present day, the history of Lithuanian bridges has not been devoted consistent attention. Bridges are complex and exceptional engineering structures. The history of bridge construction narrates an exciting story about the culture, the art of construction, and the scientific and technological progress of the particular historical period. These structures have indisputable historical, technological and architectural value. Moreover, they are a major integral part of road construction. Nowadays, the infrastructure of roads and bridges has expanded to the extent where people no longer realize the utmost importance of bridges. The engineers of all times attempted to design strong, durable and elegant bridges. The contemporary architects tend to devote an especially great deal of attention to the design of bridges. The paper presents the old Lithuanian bridges (from the 13th -18th centuries) and reviews the early railroad bridges. The development of the... [to full text]
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Kayaturk, Yurdagul Serife. "Scour And Scour Protection At Bridge Abutments." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605834/index.pdf.
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ABSTRACT
SCOUR AND SCOUR PROTECTION AT BRIDGE ABUTMENTS
Kayatürk, Serife Yurdagü
l Ph. D., Department of Civil Engineering Supervisor: Prof. Dr. Mustafa Gö
gü
S Co-Supervisor: Dr. Mehmet Ali Kö
kpinar January 2005, 213 pages Bridge failures are mainly caused by scouring the bed material around bridge foundations during flood. In this study, scour phenomenon around bridge abutments is experimentally studied. Effect of abutment size, location and size of the collars placed around the abutments, time evaluation of scour hole around the abutment, scour characteristics of abutment and pier interaction were experimentally investigated. Scour measurements were conducted in a rectangular channel of 30 m long and 1.5 m wide filled with erodable uniform sediment. In the first part of the study, in order to investigate the size effect of the abutment on the maximum scour depth, abutments of nine different sizes were tested for three different water depths. It was found that the length of the abutment is more important parameter than the width of it. Secondly, efficiency of various sizes of collars, which are used to reduce the local scour depth, located at different elevations around the abutments was determined. It was noticed that when the collar width was increased and placed at or below the bed level, the reduction in scour depth increases considerably. Some tests for partial-collar arrangements around the abutments were conducted and it was shown that instead of full-collar one can use partial-collar arrangements around the abutments to achieve the same efficiency as the full-collar. Time development of scour holes around the abutments with and without collar cases were recorded. It was observed considerable reductions in scour depths around the abutments can be obtained with collars compared to the cases in which there are no collars over the same time period. Finally, a series of experiments were carried out to investigate the interaction between bridge abutments and piers related to the local scour around them. Based on the experiments conducted with two different abutment lengths and pier diameters varying the lateral distances between them it was observed that scour depth reduction capacities of collars vary significantly while comparing a single abutment or pier.
4
Kirch, Arno [Verfasser]. "Alleviation of the Response of Slender Bridges to Wind Action Using Different Types of Controlled Actuators / Arno Kirch." Aachen : Shaker, 2014. http://d-nb.info/1050343956/34.
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Kirch, Arno [Verfasser], and Udo [Akademischer Betreuer] Peil. "Alleviation of the Response of Slender Bridges to Wind Action Using Different Types of Controlled Actuators / Arno Kirch ; Betreuer: Udo Peil." Braunschweig : Technische Universität Braunschweig, 2013. http://d-nb.info/1175890634/34.
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Oladimeji, Fasheyi Adebowale. "Bridge Bearings : Merits, Demerits, Practical Issues, Maintenance and Extensive Surveys on Bridge Bearing." Thesis, KTH, Bro- och stålbyggnad, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104240.
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A technical solution to the problem of unavoidable movements in bridge structures is the use of bridge bearings. Bridge bearings are small integral parts of the entire bridge structure serving several purposes, such as connection, transfer of forces, allowing movements, force damping etc. However, bridge bearings could create more problems for the bridge structure than it solves if not properly understood, especially when it receives less attention than it deserves. Technical and practical issues, such as selection of the right bearing type for use, merits and demerits of different bearing types, maintenance and monitoring, replacement, life cycle cost etc. are all imperative to ensure that bearings satisfy their purpose. This study takes into consideration the practical and theoretical experience available for the use of bridge bearings. Two electronic surveys were used to garner knowledge and expertise from bridge engineers, bearing manufacturers and other stake holders in the course of this study, also practical knowledge concerning various types and problems of bridge bearings, maintenance, repair and replacement, life cycle costing etc. were employed in addition to physical investigation of bridge bearings in the Stockholm area of Sweden. Generally, all bearing types were found to perform their functions satisfactorily when in good conditions, though inevitable problem of degradation reduces the life span of these bearings, especially the ones made mainly of steel being affected by corrosion. Those made of rubber components also degrade and perform poorly in low temperatures and under high load magnitude, though they are the most economical solution to many problems, especially in seismically active areas. Modern and enclosed bearing types such as pot, spherical, disc, LRB, FPB etc. are best used in critical conditions like high vertical load, extensive degree/extent of movement, seismic areas etc. but they are expensive solutions due to technicality in construction, and they are not exempted from various problems of degradation.
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Mohammed, Safiuddin Adil. "Impact of AASHTO LRFD bridge design specifications on the design of Type C and AASHTO Type IV girder bridges." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4841.
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This research study is aimed at assisting the Texas Department of Transportation
(TxDOT) in making a transition from the use of the AASHTO Standard Specifications
for Highway Bridges to the AASHTO LRFD Bridge Design Specifications for the design
of prestressed concrete bridges. It was identified that Type C and AASHTO Type IV are
among the most common girder types used by TxDOT for prestressed concrete bridges.
This study is specific to these two types of bridges. Guidelines are provided to tailor
TxDOT's design practices to meet the requirements of the LRFD Specifications.
Detailed design examples for an AASHTO Type IV girder using both the
AASHTO Standard Specifications and AASHTO LRFD Specifications are developed
and compared. These examples will serve as a reference for TxDOT bridge design
engineers. A parametric study for AASHTO Type IV and Type C girders is conducted
using span length, girder spacing, and strand diameter as the major parameters that are
varied. Based on the results obtained from the parametric study, two critical areas are
identified where significant changes in design results are observed when comparing
Standard and LRFD designs. The critical areas are the transverse shear requirements and
interface shear requirements, and these are further investigated.
The interface shear reinforcement requirements are observed to increase
significantly when the LRFD Specifications are used for design. New provisions for
interface shear design that have been proposed to be included in the LRFD
Specifications in 2007 were evaluated. It was observed that the proposed interface shear
provisions will significantly reduce the difference between the interface shear
reinforcement requirements for corresponding Standard and LRFD designs.The transverse shear reinforcement requirements are found to be varying
marginally in some cases and significantly in most of the cases when comparing LRFD
designs to Standard designs. The variation in the transverse shear reinforcement
requirement is attributed to differences in the shear models used in the two
specifications. The LRFD Specifications use a variable truss analogy based on the
Modified Compression Field Theory (MCFT). The Standard Specifications use a
constant 45-degree truss analogy method for its shear design provisions. The two
methodologies are compared and major differences are noted.
8
Panesar, Daman K. "Reliability of Alberta's type G stringer bridges." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ28633.pdf.
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Arginhan, Oktay. "Reliability Based Safety Level Evaluation Of Turkish Type Precast Prestressed Concrete Bridge Girders Designed In Accordance With The Load And Resistance Factor Desing Method." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612723/index.pdf.
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The main aim of the present study is to evaluate the safety level of Turkish type precast prestressed concrete bridge girders designed according to American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) based on reliability theory. Span lengths varying from 25 m to 40 m are considered. Two types of design truck loading models are taken into account: H30S24-current design live load of Turkey and HL93-design live load model of AASHTO LRFD. The statistical parameters of both load and resistance components are estimated from local data and published data in the literature. The bias factors and coefficient of variation of live load are estimated by extrapolation of cumulative distribution functions of maximum span moments of truck survey data (Axle Weight Studies) that is gathered from the Division of Transportation and Cost Studies of the General Directorate of Highways of Turkey. The uncertainties associated with C40 class concrete and prestressing strands are evaluated by the test data of local manufacturers. The girders are designed according to the requirements of both Service III and Strength I limit states. The required number of strands is calculated and compared.
Increasing research in the field of bridge evaluation based on structural reliability justifies the consideration of reliability index as the primary measure of safety of bridges. The reliability indexes are calculated by different methods for both Strength I and Service III limit states. The reliability level of typical girders of Turkey is compared with those of others countries. Different load and resistance factors are intended to achieve the selected target reliability levels. For the studied cases, a set of load factors corresponding to different levels of reliability index is suggested for the two models of truck design loads. Analysis with Turkish type truck models results in higher reliability index compared to the USA type truck model for the investigated span lengths
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Zhang, Rui. "Mechanics of micromachined bridge-type accelerometer." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/1285.
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Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005Having simple structure and high sensitivity, micro accelerometer is a type of popular transducer used to measure the acceleration in a great variety of conditions. The bridge-type micro accelerometer is a typical micro accelerometer and has many types. As one of research project of Kentron in South Africa, the thesis presented here analyzes the bridge-type capacitive nticro accelerometer (BTCMA) and the bridge-type micro accelerometer with two piezoelectric thin films read-out (BTPMA). In this thesis, the similar structures are used on BTCMA and BTPMA For proving the fundamental mode of the structure can measure acceleration and utilizing the structural and electric characteristic to avoid the effect of higher modes, the program CoventorWare for nticro-electric-mechanical system (MEMS) design and analysis is used here to analyze the modes of these two structures, The two group piezoelectric thin films of BTPMA can be connected in serial or parallel configurations. Integrating piezoelectric effect method, strength method and energy method, the analytical analysis of these two configurations has been done with particular emphasis on the elastic characteristics of the thin films. The analytical formulas of transducer, sensitivity, resonance frequency, noise, quality factor, ntinimum detectable signal and maximum detectable range are obtained. According to the comparison results between these two configurations, the charge output in parallel configuration is a little more than that in serial configuration and the sensitivity in serial configuration is much higher than that in parallel configuration. Finally, a calculation of certain practical nticro accelerometer size is used to prove the above conclusions. On the base of capacitance theory, strength method and energy method, the analytical analysis of the BTCMA has been done in this thesis.
11
Moussi, Jessika, and Ali Mohammed. "Lastmodellering i FEM-Program : Trafiklaster på broar." Thesis, KTH, Byggteknik och design, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-233511.
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I byggbranschen har nya metoder för lastanalys utvecklats och digitaliserats med hjälp av datorer och kraftfulla analysprogram. En stor del av dagens lastanalys utförs med hjälp av FEM baserade program. Dessa program bidrar till mer tidsbesparing och större noggrannhet.FEM-Design är ett FEM baserad analys program som kan hantera olika typer konstruktioner. Trots detta är inte programmet tillräckligt lämpat för brodimensionering när det gäller trafiklaster på broar. Konstruktören behöver därför gå igenom Eurokods-och Trafikverkets regler och krav för att hitta information kring trafikaster och därefter skapa dem i programmet.För att kunna utnyttja programmets kraftiga funktioner och anpassa det mer för brodimensionering, behöver programmet kompletteras med nya funktioner som underlättar hantering av rörliga laster. Målet var att undersöka olika lastmodeller enligt Eurokoden och TRVFS, och skapa dem i FEM-Design. Dessutom peka ut vilka förbättringar som kan utföras i programmet för att underlätta hantering av dessa trafiklaster.Tillsammans med StruSoft AB utfördes lastdefinitioner av Lastmodell 1, Lastmodell 2, och Lastmodell 3 i programmet FEM-Design.Resultatet av arbetet visar en mängd nya fordonslaster som definierades i programmet och som är baserade på det europeiska Eurokoden, och inhemska krav.Programmet FEM-Design går framgångsrikt att göras mer praktisk för brodimensioneringar. Med fortsatta studier, extra funktioner, och mer lastmodell-definitioner har FEM-Design potentialen att även konkurrera med andra bro-program.In the construction industry, new methods of load analysis have been developed and digitized using computers and powerful analysis programs. A large part of today's load analysis is performed using FEM based programs, which contributes to time saving and greater accuracy.FEM-Design is a FEM based analysis program that can handle different types of constructions. Nevertheless, the program is not sufficiently applied to bridge dimensioning when it comes to traffic loads on bridges. The designer therefore needs to review the Eurocode rules and national requirements in order to find information about the moving loads and then define them in the program.In order to utilize the program's powerful features and suit it more for bridge dimensioning, the program needs to be complemented with new features that will facilitate the handling of moving loads. The goal was to examine the different load models according to the Eurocode and TRVFS, and creates them in FEM Design. In addition, identify which improvements can be made to the program to facilitate the handling of the traffic loads.Together with StruSoft AB, load definitions of Load model 1, Load model 2, and Load model 3 were performed in the FEM-Design program.The result of the work shows a number of new vehicle loads as defined in the program, which are based on the European Eurocode, and the country's special requirements.The program can successfully be made more practical for bridge constructions. With continued studies, additional features, and more load model definitions, FEM-Design has the potential to compete with other bridge programs.
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Zeeshan, Syed. "Verification of Bridge Foundation Fixity for Three Different Types of Soil." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/theses/1859.
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The purpose of this study is to investigate the footing fixity effect on the lateral deflection of a bridge pier for different types of soil. Generally, the rotational restraint coefficient at top and bottom of pier (degree of fixity of the pier) is used to compute the effective length factor of pier which is in turn used to determine the pier deflection. The magnitude of the deflection is used to determine whether the p-delta force effect should be considered while designing the pier. However, the pier deflection is usually computed by assuming that the pier footing is completely fixed to the ground. In case of soil under footing, rotational restraint coefficient is taken as five for all types of soils. In this study, finite element analysis method was used to determine the pier deflection by providing three actual soil environments and compare the results with the traditional approach. Hence, the rotational restraint coefficient will be modified according to the deflection computed from the finite element analysis.
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Ramos, Pablo D. Jr. "SYSTEM IDENTIFICATION OF A BRIDGE-TYPE BUILDING STRUCTURE." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/944.
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The Bridge House is a steel building structure located in Poly Canyon, a rural area inside the campus of California Polytechnic State University, San Luis Obispo. The Bridge House is a one story steel structure supported on 4 concrete piers with a lateral force resisting system (LFRS) composed of ordinary moment frames in the N-S direction and braced frames in the E-W direction and vertically supported by a pair of trusses. The dynamic response of the Bridge House was investigated by means of system identification through ambient and forced vibration testing. Interesting findings such as diaphragm flexibility, foundation flexibility and frequency shifts due to thermal effects were all found throughout the mode shape mapping process. Nine apparent mode shapes were experimentally identified, N-S and E-W translational, rotational and 6 vertical modes. A computational model was also created and refined through correlation with the modal parameters obtained through FVTs. When compared to the experimental results, the computational model estimated the experimentally determined building period within 8% and 10% for both N-S and E-W translational modes and within 10% for 4 of the vertical modes.
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Rajalingola, Manvitha. "Analysis of Distresses in Asphalt Pavement Transitions on Bridge Approaches and Departures." Scholar Commons, 2017. https://scholarcommons.usf.edu/etd/7437.
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Some highway agencies in the United States are experiencing frequent distresses in asphalt pavements on bridge approaches/departures. Commonly observed distresses include alligator cracking and rutting, which reduce roadway smoothness and safety. To lessen the distresses in pavements it is needed to investigate the extent and root causes of the problem. Based on Florida highway conditions, this research study mainly focused on1. Literature review and identification of the extent of the problem; 2. Collection of relevant pavement condition data and descriptive analysis; 3. Development of statistical models to determine factors influencing the distresses in asphalt pavements on bridge approaches/departures. To the best of my knowledge, this is the first study that uses a statistical model to determine the factors that are responsible for causing asphalt pavement distresses on bridge approaches/departures.
As part of the literature review, a nationwide questionnaire survey was targeted towards U.S state DOTs. The data collection and analysis specific to the Florida highways found that in 2015 on Florida Interstate highways, about 27% bridges with asphalt pavements on their approaches/departures showed signs of cracking, and about 20% bridges have noticeable rutting in their approach or departure pavements.
A random parameter linear regression model was applied to examine the factors that may influence distresses in asphalt pavements in Florida. Pavement condition was evaluated based on the Florida Department of Transportation (FDOT) 2015 pavement condition data and video log images, and other relevant data were collected from various sources such as FDOT Roadway Characteristics Inventory (RCI) database, FDOT pavement management reports, and FDOT Ground Penetrating Radar (GPR) survey reports. A constraint existed in the availability of the GPR data that can give pavement layer thickness, which limited the number of bridge approach pavement sections included in the statistical modeling. Based on the limited data, the estimated results from the random parameter linear regression model showed that the variables influencing distresses in asphalt pavements on bridge approaches/departures, in terms of rutting and roughness, may include pavement age, annual average daily truck traffic, and surface friction course.
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Rydén, Michaéla. "Impact of different concrete types on the LCA of NCC Composite bridge." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177861.
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Traditionell betong används i majoriteten av broar som byggmaterial. Om byggnadsmaterialet skulle kunna ersättas av en betong med mindre miljöpåverkan, kan stora delar av miljöpåverkan minskas. I denna avhandling, ska NCC:s samverkansbro utredas, där tre olika betongtyper ska testas i dess olika konstruktionsdelar. Samverkansbron kommer att jämföras i tre olika scenarier av byggmaterial: traditionell betong, traditionell betong innehållande 5 % slagg och injekteringsbetong. Jämförelsen kommer att utföras genom en livscykelanalys (LCA) med hjälp av programvaran GaBi 6.5. Resultatet av modelleringen i GaBi presenteras på samma sätt som i en miljövarudeklaration (EPD). I presentationen av resultatet kommer diagram och tabeller visualisera de resultat som erhållits i livscykelanalysen. Det erhållna resultatet visar att vid jämförelse av de tre scenarierna ger injekteringsbetong en mindre klimatpåverkan i majoritet av resultaten.Traditional concrete is used in the majority of bridges as a building material. If the building material could be replaced by a concrete with less environmental impact, large parts of the environmental impact could be reduced. In this dissertation, NCC Composite Bridge is to be investigated, where three different concrete types are to be tested in its various design elements. The composite bridge will be compared in three scenarios: traditional concrete, traditional concrete with slag as part of binder and prepact concrete. The comparison will be carried out by a Life Cycle Assessment (LCA) using the software GaBi. The outcome will be in form of an Environmental Product Declaration (EPD) table. (NCC has implemented the EPD system into the company with the ambition to easier and more thorough provide a legit evaluation of the environmental impact.) In the presentation of the result, diagrams and tables visualizes the results obtained in the EPD. The result obtained has shown that comparing the three scenarios; prepact concrete provides a less environmental impact and if replacing traditional concrete with prepact, savings of the environment can be made.
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Ball, Payne. "The Use of 0.7-in. Prestressing Strand in Various Bridge Girder Types." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1559058240194886.
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Catacoli, Seku Samory Mosquera. "Displacement demands for performance based design of skewed bridges with seat type abutments." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46020.
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Skewed bridges are irregular structures due to the geometry of the deck and bents. Past earthquakes indicate that skewed bridges with seat type abutments exhibit greater damage than their non-skewed pairs. The damage has been attributed to in-plane rotations caused by pounding between the skewed deck and its abutments during strong ground shaking.
This thesis combines experimental and analytical approaches to understanding the displacement demands on skewed bridges. As part of the experimental studies, results from ambient vibrations tests help to better understand the importance of directionality in the lateral response of skewed bridges. The predominant direction of the transverse response occurs in the direction of the skew bents; whereas the predominant direction of the longitudinal response is perpendicular to the skew. In addition, the analysis of records from an instrumented skewed bridge confirmed accelerations that could produce in-plane rotations of the deck.
A comprehensive parametric study based on nonlinear dynamic analyses was performed to evaluate the effects of different skew angles, abutments types, and soil-foundation-structure interaction. The results demonstrated that elastic methods recommended by current seismic design provisions, and commonly used in standard practice, do not properly capture the in-plane rotations of the deck due to pounding. To overcome this shortcoming, a simple and effective method is proposed here to evaluate the displacement demands of skewed piers accounting for in-plane deck rotations.
The proposed method uses validated simplified nonlinear models to generate torsional sensitivity charts for specific bridge prototypes. The charts provide peak in-plane deck rotation estimates as a function of bridge skew angle and the in-plane rotational period. An advantage of this approach is that it requires the designer to only conduct a linear dynamic analysis of the bridge. Nonlinear analysis required to assess the in-plane deck rotation is replaced here by torsional sensitivity charts. The proposed approach is able to predict the displacement response for a comprehensive range of skewed bridge prototypes by capturing the effects of the main parameters controlling the response. The information presented in this thesis will help improve the existing recommendations for performance based design of skewed bridges.
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Yildirim, Mehmet Sinan. "Computer-assisted Design Methodology For Armoring Type Bridge Scour Countermeasures." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615331/index.pdf.
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Scour at bridge piers is considered as a significant safety hazard. Hence, scour countermeasure design
plays a critical role to hinder the scour potential at bridges. The selection methodology for a scour
countermeasure varies with respect to site conditions, economy, availability of material and river
characteristics. The aim of this study is to review the literature on this topic to gather universally
accepted design guidelines. A user-friendly computer program is developed for decision-making in
various sequential steps of countermeasure design against scouring of bridge piers. Therefore, the
program is eventually intended to select the feasible solution based on a grading system which deals
with comparative evaluation of soil, hydraulic, construction and application aspects. The program
enables an engineer to carry out a rapid countermeasure design through consideration of successive alternatives. A case study is performed to illustrate the use of this program.
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Boehm, Kurtis McKinley Barnes Robert W. "Structural performance of self-consolidating concrete in AASHTO type I prestressed girders." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Civil_Engineering/Thesis/Boehm_Kurtis_25.pdf.
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Daniels, Mark Leo. "A floristic study of a former land bridge in The Bahama Archipelago." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1470149291.
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Naz, Nabila Rauf [Verfasser]. "Synthesis and reactions of Janus-type bis(NHCs), tuned by phosphorus bridges / Nabila Rauf Naz." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/122897893X/34.
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Xie, Haiyin. "The effects of surface roughness and vehicle suspension type on highway bridge dynamics." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0003/MQ42707.pdf.
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Riad, Amr H. "Rehabilitation of HC-type bridge girders using CFRP-sheets/strips or external post-tensioning." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ38640.pdf.
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Jílek, Roman. "Model překladače." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219819.
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The aim of this Master's thesis is characterization Programmable Logic Controllers, description of Industrial interface – AS-Interface, assembling electronic components at construction of model of bridge type track shifter and programming model. First part is focused to Programmable Logic Controllers their qualities, characterization and separation and describing AS-Interface and its components. Second part is describing equipment and locations of equipment. Third part is about software. Fourth part is describing programming. Next part is about visualization and last part contains instructions for laboratory work.
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KUSAKARI, Keiichirou, Masahiko SAKAI, and Toshiki SAKABE. "Primitive Inductive Theorems Bridge Implicit Induction Methods and Inductive Theorems in Higher-Order Rewriting." IEICE, 2005. http://hdl.handle.net/2237/9580.
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LeBlanc, David, and Mark Terrell. "Dendroclimatic Analysis Using Thornwaite-Mather-Type Evapotranspiration Models: A Bridge Between Dendroevology and Forest Simulation Models." Tree-Ring Society, 2001. http://hdl.handle.net/10150/262535.
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The objective of this study was to document correlations between radial growth of white oak (Quercus alba L.) at 128 sites in the eastern US and variables related to early growing season site water balance, including the ratio of actual to potential evapotranspiration (AE/PE) computed based on the procedure described by Thornthwaite and Mather (1957). White oak radial growth was strongly correlated with all measures of early growing season water balance, but was most consistently and strongly correlated with Palmer Drought Severity Index (PDI) and AE /PE ratio computed using a modified Thornthwaite-Mather model. We propose that dendroecological analyses of tree growth responses to climate based on AE /PE variables could provide empirical data useful for improving climate response algorithms in forest simulation models. This change of standard practice could also improve biological interpretations derived from such dendroecological analyses.
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Waggoner, Marsha Frakes. "Dismembered Virgins and Incarcerated Brides: Embodiment and Sanctity in the Katherine Group." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1373%5F1%5Fm.pdf&type=application/pdf.
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Kolb, Marcus Michael. "THE RELATIONSHIP BETWEEN STATE APPROPRIATIONS AND STUDENT RETENTION AT PUBLIC, FOUR-YEAR INSTITUTIONS OF HIGHER EDUCATION." Diss., Tucson, Ariz. : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1025%5F1%5Fm.pdf&type=application/pdf.
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Fowler, Leslie Ann. "PCB Effects on Brain Type II 5'Deiodinase Activity in Developing Brids." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/9768.
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PCBs are known to cause thyroid disruption in laboratory rats and are thought to be the causal agent in thyroid gland alterations in herring gulls in the Great Lakes. This study examined the regulation of thyroid hormone supply during development in (1) domestic chicken embryos (Gallus domesticus) exposed to a specific dioxin-like PCB congener (PCB-126) and (2) herring gull (Larus argentatus) embryos and pre-fledglings from Great Lakes sites with different chemical pollutant exposures. Specifically, PCB effects on thyroid status were evaluated by measuring plasma thyroid hormone concentrations and brain type II 5'D activity (to determine if PCB exposure was associated with alteration in brain 5'D type II activity that could maintain local T3 supply to the brain). If PCB-126 and PCB mixtures altered thyroid function, we expected to see decreased plasma thyroid hormone concentrations and subsequent increases in 5'D-II activity. Chicken eggs were injected (into the air cell) before incubation with five dose levels (0.0512, 0.128, 0.32, 0.64, 0.8 ng/g) of PCB-126 (3,3, 4,4',5-pentachlorobiphenyl), or vehicle (sunflower oil); sampling was on day 20 of the 21-day incubation period. Studies on PCB-treated embryos included a preliminary study and a larger study encompassing a serious of smaller studies. Herring gull embryos (at pipping, on day 25 of the 26 day incubation), and 28-day pre-fledgling chicks were sampled (for two field seasons) at several Great Lakes sites with different contaminant exposures (with Kent Island being the reference site). In PCB-treated chicken embryos, there were no statistically significant decreases in plasma T4 or T3 concentrations and no significant increases in brain 5'D-II activity in either the preliminary or the larger study. We found no clear pattern of altered thyroid function in herring gulls from polluted Great Lakes' sites. Plasma TH concentrations were not significantly decreased and 5'D-II activity did not significantly increase in birds from more contaminated sites in comparison to birds from Kent Island or sites with less contamination. Although pipped embryos from Strachnan Island had a significant increase in 5'D-II activity when compared to Kent Island, there were no differences in plasma TH concentrations, and brain 5'D-II activity was not significantly increased in birds from sites with greater PCB loads than Strachnan Island. Plasma T4 and T3 concentrations were significantly decreased in prefledglings from West Sister Island and Detroit Edison in comparison to Kent Island, but there was no subsequent increase in brain 5'D-II activity. The present study is the first to evaluate the potential effects of PCBs, alone and in a mixed environmental exposure, on circulating THs and brain 5'D-II activity in developing birds. Although thyroid function was not altered by the specific PCB congener used in my study or by exposure to environmental pollutants, more complete evaluations are needed before determining whether PCBs alter thyroid function in birds.Master of Science
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Mehranipornejad, Ebrahim. "Evaluation of AASHTO design specifications for cast-in-place continuous bridge deck using remote sensing technique." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001584.
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Qu, Dayu. "EMI Characterization and Improvement of Bi-Directional DC/DC Converters." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35246.
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A worldwide awareness of the environment is accelerating fuel cell vehicle development. With respect to power electronics, special requirement is on the development of high efficiency, high voltage ratio bi-directional DC/DC converter for fuel cell energy system management.
In this paper, two bi-directional DC/DC converters, which are developed for Ford Motor Company’s fuel cell vehicle, are compared from different aspects. Comparison is concentrated on the circuit topology and EMI performance. Emphasis is placed on soft-switch, hard-switch, synchronized rectification, auxiliary start-up winding and their effect on EMI performance in this kind of isolated bi-directional converter.
Comparison includes circuits analysis and test result. The EMI test setup is described. EMI measurements are given and explained. EMI solutions for bi-directional DC/DC converter are discussed. An EMI filter is designed and final test result is given.Master of Science
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Hu, Xuequn. "Modeling Endogenous Treatment Eects with Heterogeneity: A Bayesian Nonparametric Approach." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3159.
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This dissertation explores the estimation of endogenous treatment effects in the presence of heterogeneous responses. A Bayesian Nonparametric approach is taken to model the heterogeneity in treatment effects. Specifically, I adopt the Dirichlet Process Mixture (DPM) model to capture the heterogeneity and show that DPM often outperforms Finite Mixture Model (FMM) in providing more flexible function forms and thus better model fit. Rather than fixing the number of components in a mixture model, DPM allows the data and prior knowledge to determine the number of components in the data, thus providing an automatic mechanism for model selection.
Two DPM models are presented in this dissertation. The first DPM model is based on a two-equation selection model. A Dirichlet Process (DP) prior is specified on some or all the parameters of the structural equation, and marginal likelihoods are calculated to select the best DPM model. This model is used to study the incentive and selection
effects of having prescription drug coverage on total drug expenditures among Medicare beneficiaries.
The second DPM model utilizes a three-equation Roy-type
framework to model the observed heterogeneity that arises due to the treatment status, while the unobserved heterogeneity is handled by separate DPM models for the treated and untreated outcomes. This Roy-type DPM model is applied to a data set consisting of 33,081 independent individuals from the Medical Expenditure Panel Survey (MEPS), and the treatment effects of having private medical insurance on the outpatient expenditures are estimated.
Key Words: Treatment Effects, Endogeneity, Heterogeneity, Finite Mixture Model, Dirichlet Process Prior, Dirichlet Process Mixture, Roy-type Modeling, Importance Sampling,
Bridge Sampling
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Mendroková, Magda. "Most v obci Návsí přes řeku Olši." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226070.
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The diploma thesis deals with design and assessment of steel arched bridge with the semi through bridge deck placed on the third-class road. This steel structure is drawn up to bridge water barrier – the river Olše in Návsí. The distance between axes lay on abutments is 48,5 meters. The bridge´s supporting structure consists of two steel arches angled towards each other and fastened to the foundation blocks. The supporting beam of the bridge deck is tied to the arch by tie-rods. The tie-rods are designed to the V-shaped system.
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Honeš, Filip. "Ocelová lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226918.
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The main subject of master´s thesis is design of the construction of pedestrian steel bridge via the river Bečva in Přerov. It was made a three different types of the steel construction. The resulting draft is worked up in details. Span of the pedestrian bridge is 104 metres. The carrying construction is made from a two mutually-opening arches. Between the arches are hanged a semi through type decks.
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Quintili, Aurora Elisabeth. "The singular type woman : En narratologisk och genusteoretisk analys av Shirley Jacksons ”The Honeymoon of Mrs Smith (Version II): The Mystery of the Murdered Bride”." Thesis, Mälardalens högskola, Akademin för utbildning, kultur och kommunikation, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-54202.
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Efter Shirley Jacksons död år 1965 verkade allmänhetens uppmärksamhet gentemot hennes litterära produktion avta. Idag kan vi däremot observera ett kraftigt ökat intresse för hennes författarskap och de tematiker som behandlas, det vill säga kvinnans isolering, de sociala normernas inflytande på den mänskliga erfarenheten och ödets obarmhärtighet. Denna uppsats fokuserar på den postumt utgivna novellen med titeln ”The Honeymoon of Mrs Smith (Version II): The Mystery of the Murdered Bride”. Syftet med denna uppsats är att belysa hur narratologiska strukturer återspeglar mönster och regelbundenheter som kan tolkas utifrån ett genusperspektiv. Här finns först ett intresse för att analysera den valda novellen utifrån Monika Fluderniks (1996, 2009) definition av berättelse och hennes teori om experientiality, vilket resulterar i en analys av novellens narratologiska struktur. Uppsatsens andra mål är att åskådliggöra hur berättelsens narratologiska struktur påvisar tecken av interna, fiktiva samhällsstrukturer som kan analyseras utifrån Yvonne Hirdmans (1988, 2001) genusteori. Denna kombinerade analys har slutligen som mål att belysa hur den mänskliga erfarenheten och dess agerande inom berättelsen påverkas av mönstereffekter och regelbundenheter som styr relationen mellan könen. Slutsatsen som dras här är att Fluderniks (1996, 2009) teori agerat som effektiv ingång till hur de olika elementen som formar den analyserade berättelsen samverkar för att ge upphov till de samhälleliga mönster och regelbundenheter som Hirdman (1988, 2001) beskriver och kritiserar. Kombinationen av narratologisk analys och genusteoretisk analys visade sig i slutändan vara effektiv för att belysa hur de samhälleliga dynamiker som styr relationen mellan könen inom berättelsen påverkar hur människorna inom den agerar.
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Calancea, Sergiu. "Synthèse et caractérisations de nouveaux complexes binucléaires à transfert d’électron de type {Fe(µ-CN)M} (M = Fe, Mn, Co)." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14802/document.
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L’une des grandes directions de recherche dans la chimie moderne est la synthèse et l’étude denouveaux composés « commutables » capables de modifier leurs propriétés sous l’effet de stimuli extérieurs (température, lumière, champ magnétique ou électrique…). Ces systèmes peuvent stocker une information à l’échelle moléculaire. Dans ce contexte, parmi les systèmes les plus étudiés en chimie de coordination figurent les réseaux et les analogues moléculaires du bleu de Prusse. Cette thèse est dédiée à la synthèse et aux caractérisations de nouveaux analogues moléculaires du bleu de Prusse à transfert d’électron de type {Fe(µ-CN)M} (M = Fe, Mn, Co). Dans le premier chapitre sont présentées les familles de composés commutables à transfert d’électron par ordre décroissant de leur dimensionnalité, des systèmes 3D vers des systèmes discrets 0D. Le deuxième chapitre regroupe la synthèse et les caractérisations structurales, spectroscopiques, magnétiques, et électrochimiques de complexes-précurseurs de type [MII(LN5)]2+ et [FeIII(LN3/LN2)(CN)n]- (n = 2, 3) (LN5, LN3, LN2 étantdes ligands azotés penta-, tri- ou bidentes, respectivement) qui seront ensuite utilisés dans la synthèse des composés binucléaires. Le troisième chapitre présente la synthèse et les études structurales,spectroscopiques, magnétiques, optiques et électrochimiques de quatre nouveaux composés binucléaires paramagnétiques {FeIII(µ-CN)MII} (MII = Fe, Co). Enfin, le quatrième chapitre se focalise sur la synthèse et les propriétés spectroscopiques, magnétiques, photomagnétiques et électrochimiques de trois nouveaux complexes binucléaires diamagnétiques {FeII(µ-CN)CoIII} à transfert d’électronOne of the main research directions of modern chemistry is the synthesis and study of new switchablecompounds which can change their properties under external stimuli (temperature, light, magnetic orelectric field…). These systems can store the information at the molecular level. In this contextamongst the most studied systems in coordination chemistry are the 3D networks and the molecularPrussian blue analogs. This thesis deals with the synthesis and characterizations of new{Fe(µ-CN)M} (M = Fe, Mn, Co) molecular Prussian blue analogs. In the first chapter electrontransfer compounds are described in order of decreasing of their dimensionality, from 3D to thediscrete 0D systems. The second chapter describes the synthesis and structural, spectroscopic,electrochemical and magnetic characterizations of [MII(LN5)]2+ precursors (MII = Fe, Mn, Co) and[FeIII(LN3/LN2)(CN)n]- (n = 2, 3) (LN5, LN3, LN2 - nitrogen-based penta-, tri- and bi-dentate ligands,respectively), which are used in the synthesis of the binuclear complexes. Chapter three presents thesynthesis and structural, magnetic, spectroscopic and electrochemical studies of four binuclearparamagnetic {FeIII(µ-CN)MII} complexes (MII = Fe, Co). Chapter four is focused on the synthesisand spectroscopic, magnetic, photomagnetic and electrochemical properties of three binucleardiamagnetic {FeII(µ-CN)CoIII} electron transfer complexes
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Yan, Cai Jian, and 蔡劍諺. "The Structureal Analysis of Three Types ofSteel Arch Bridges." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44018898914269110093.
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碩士國立高雄應用科技大學
土木工程與防災科技研究所
97
In this paper, we applied the finite element method to build a bridges model, further more to proceed the comparison of three-dimensional static and dynamic analysis. Simulation analysis through computer, we understand the characteristics and dynamic behavior of bridge structures. Therefore the objective of this paper is to discuss the shape and both frequency and state of vibration of Bridge structure, as well as the seismic force structure under the dynamic response analysis. The paper set up three different types of bridges as an example, in order to achieve reasonable initial shape, and then use this early forms position to analysis the deformation, vibration frequency and vibration state under load combinations, according to the basic and dynamic characteristic of structure that we understanding, we further analyzing the seismic force structure under the dynamic response. Input the value to the model that in this paper set up, we can obtain the bridge model under dynamic response of seismic force structure through the program analyzing. Respectively input the different combination of directions under seismic, we can identify the direction against bridge structure under the earthquake, and fully control the dynamic behavior of bridge structure under massive earthquake. By the numerical analysis results indicate that under the static traffic loads, the major deformation occurred in the vertical of bridge girders, and low-frequency vibration state occurred in the vertical of the main deck.
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Tseng, Wei-Hsiang, and 曾煒翔. "The Influence of Railing Types on the Aerodynamic Behavior of Pedestrian Bridges." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/v56788.
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碩士淡江大學
土木工程學系碩士班
106
Most bridge section model tests usually focus on the bridges for vehicles. Previous studies have shown that adding railings or grids has less influence on the aerodynamic behavior of these types of structures because of their large section widths. However, the pedestrian bridge has a smaller section width, and the height of the railing accounts for a large proportion of the total height of the bridge. Therefore, the impact of railings on the aerodynamic behavior of the pedestrian bridge cannot be ignored. This study mainly investigates the influence of railings on the aerodynamic behavior of the pedestrian bridges by using section model tests and a numerical analysis. The aerodynamic wind coefficients, flutter derivatives, flutter critical wind speeds and buffeting responses of section models with different types of railings are studied. The railings with different porosities of grids(70%, 50%, 40%), horizontal glass (40%, 20%), and vertical glass (40%, 20%) are studied. The results show that the aerodynamic coefficients and flutter derivatives will change along with the variations of the porosities and types of railings. The main influence on the aerodynamic behavior is the change of the porosities. As the porosity decreases, the cross section gradually changes from a streamlined cross-section to a bluff section. The H1* of the models with the glass railings will produce vortex shedding effects at low normalized wind speeds, and the positive A2*will occur at lower wind speeds as the porosity decreases. The analysis of the flutter critical wind speed shows that the porosity of the railings is the main factor affecting the flutter critical wind speed. The flutter critical wind speed decreases with the reduction of the porosity of the railing. The numerical analysis also shows the same trend. The flutter critical wind speed varies with different types of the railing. For example, grid railings have better performances than the glass railings, and the vertical glass railings have better performances than the horizontal glass railings etc. In general, turbulent flow increases the flutter critical wind speed in most cases as we expected. However, this trend is reversed in some cases. The results also show that the flutter critical wind speeds decrease and the buffeting responses increase as the angles of wind attack are negative. If the bridges are possibly attacked by winds at negative angles from the wind field analysis, then the torsional frequency of the bridge should be increased and the railings with high porosities should be used. If glass railings are used, the vertical glass railings are suggested. The results obtained from the experiment shows that the different types of railings greatly affect the aerodynamic behavior of the footbridges. Therefore, we should take the railing effect of the pedestrian bridge into consideration in the wind resistance design.
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Javidi, Niroumand Saeed. "Resistance mechanism of simple-made-continuous connections in skew and non-skew steel girder bridges using conventional and accelerated types of construction." 2009. http://proquest.umi.com/pqdweb?did=1936813651&sid=2&Fmt=2&clientId=14215&RQT=309&VName=PQD.
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Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009.Title from title screen (site viewed April 22, 2010). PDF text: xx, 238 p. : ill. (chiefly col.) ; 24 Mb. UMI publication number: AAT 3386943. Includes bibliographical references. Also available in microfilm and microfiche formats.
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田立璿. "Design and Manufacture of Bridge Type Vertical Machining Center." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/94146780057076833531.
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碩士國立彰化師範大學
電機工程學系
96
Abstract The machine tool industry is gradually moving toward M shape, and machining center is developed to be with high speed, accuracy and efficiency. This study intends to investigate the main factors influencing the success of machine tool industry, including design, technology and R&D capability, in cooperation with computer-aided design / computer-aided manufacturing and factory automation system. According to the experimental result, the machining center has these functions of high speed / high accuracy in working, complex and crooked surface working, nibble movement, wide working space, good support rigidity to loading, high ratio of strength acceptance / structure weight and high movement. General bridge type machining center relies on labor operation with experienced users and limitation in the low speed machining of 6,000rpm. This type of machine occupies much floor space, and is over weight, with high manufacturing costs, unstable quality, and the lack of automatic operation. Hence the machine can not be applied to various applications. The design of intermediate type improves the spindle speed to 24,000rpm, and the rapid feed rate reaches to 48 meter per minute. These designs are based on high tech computerized control, and improves the process procedure to higher technology level to reach good support in the rigidity of structure and expand the machining area and precision. It can meet the request of various complicated machining.
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Fang, Jen-Chi, and 方貞期. "The Bridge Type Assessment of the Water Pipe Bridge Optimizing Design— Mu-Gong Water Pipe Bridge in Tainan City as an Example." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/5dfkhq.
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碩士國立高雄應用科技大學
土木工程與防災科技研究所
104
The water pipes of the Taiwan Water Corporation usually buried under the river in the past. Taiwan is located in between the Eurasian Plate and the Philippine Plate. It has been happened earthquakes frequently. The pipes buried under the river often caused damage and leakage. It is also difficult for maintain and management. The Water Company has designed water pipe bridges to replace the pipes buried under the river in recent years. There are many types of water pipe bridges in Taiwan Water Corporation such as pipe beam, π-type reinforcement beam, truss type, steel arch, cable-stayed type and mixed type, etc. Mu-gong water pipe bridge is the second main water supply pipeline for Tainan area. It is located at Zuojhen District of Tainan city. The span is about 95 meters, and the total length is over 175 meters. This study used the Checklist method and five items of assessment factors to assess the optimal design of water pipe bridge. The assessment score are calculated by weightage and scaling. The steel arch type of water pipe bridge gains the highest score. Thus, the optimizing design of Mu-gong water pipe bridge is the steel arch type.
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Jheng, Yu-Ruei, and 鄭俞睿. "Failure Modes and Construction Checklist for Y-type-column Bridges with Local Shoring." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/92255674031959934758.
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碩士國立中興大學
土木工程學系所
96
There are many construction methods for bridges, e.g., precast prestressing I-beam cantilever method, full-span precast launching method, advanced shoring method, incremental launching method, cast balanced cantilever method, precast segmental cantilever method, steel pipe outrigger trussing method, on-site shoring method, etc. However, this study probes solely into the precast segmental cantilever method for Y-type-column bridges with local shoring. Exploration of potential problems encountered in the process of designing and constructing of the bridges is performed. The measures for handling the problems and finally an autonomous checklist are created for builders’ references. The inner stress generated in various phases of the construction method might exceed the load-carrying capacity designed. Whether the attentions have been paid to the correct prestressing order is key to the success of the bridge construction. The method should carry out structural analysis along with the construction steps to confirm the stresses at any phrase are all in their allowable ranges. the scope of secondary allowance of inner stress. Study of the possible failure modes of the bridges after completion is also made herein and the likely failure load based upon the findings is proposed for designer’s reference.
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Brás, Alice Jesus José. "Melatonin: a shining bridge between chronodisruption and type 2 diabetes." Dissertação, 2017. https://repositorio-aberto.up.pt/handle/10216/105073.
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Brás, Alice Jesus José. "Melatonin: a shining bridge between chronodisruption and type 2 diabetes." Master's thesis, 2017. https://hdl.handle.net/10216/105073.
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Huang, Jain-Jr, and 黃建智. "Improving Performance of a Bridge Type Machining Center Using Optimization Methods." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/35010484252795450691.
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碩士國立中興大學
機械工程學系所
96
The purpose of this study is to improve the performance of a bridge type machining center. The changes are made up the ribs within same substructures. The objective is to increase the stiffness of the structure as well as to minimize the weight. The original design is analyzed first to understand its performance. According to the results, the working table, the bridge, and the base structures are selected to be modified. The topology and sizing optimization techniques are used to optimize the structure. MSC.Nastran is used for finite element analysis. The design space containing the original ribs is used as the design space for topology optimization. Solid elements are created within this space and these elements will form optimum reinforced structure by using topology optimization. The sizing optimization will change the thicknesses of the original ribs to optimum values. In comparison with the original design, the static and dynamic performance of some substructures is improved. The structural weight is also reduced. In general, if the topology optimization can be successfully applied in a design space, the solution by topology optimization will be better than that by sizing optimization.
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Sin-Hao-Liao and 廖信豪. "The Computer-Aided Design and Dynamic Analysis of Bridge Type Machining Centers." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/dkd8t8.
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碩士國立虎尾科技大學
機械設計工程研究所
103
In recent years the whole world toward automation in this direction. Whether it is the traditional mechanical or electronics industry will require machine tools. Mainly in the Bridge Type Machining Centers as the object of analysis. This study used CNC machine tools as an analytical model to discuss the main components of flexible elastic deformation vibration transmission mechanism and the main structure of the rigid bearing and elastomeric coupling machining estimate dynamic impact forces to perform ANSYS finite element analysis to investigate the frequency, damping and mode shapes. Using dynamic analysis software RecurDyn engaged rigid and flexible coupling analysis to bring it closer to the real operation of machine tools. The vibration generated by the moving of forces to each other between the dynamic effects simulation machine tools and machines of the components in the simulation. Use analysis software calculated resonance frequency of vibration mode to compare each other.
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Chiu, Ji-Zheng, and 邱繼正. "Cable Force Monitoring of Pedestrian Suspension Bridge by Resistance Type Strain Gauge." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/avun6z.
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碩士國立中央大學
土木工程學系
107
For cable-supported bridge, like suspension bridge and cable-stayed bridge, cable is an important part to be taken force. The structure condition of the bridge usually can be known from the change of the cable force. So cable force monitoring is an important method to ensure the safety of the cable-supported bridge. In various ways to monitor the cable force, ambient vibration method is widely used since its advantage include non-invasive, easy to operate while getting good enough data. To reduce the cost of the monitoring, this research tried to use resistance strain gauge as the device to measure the natural frequency of the structure. The related experiments include the experiment of vibration of steel bar, the experiment of vibration of reinforced cable, local measurement experiment at a pedestrian suspension bridge. The experiment result confirmed that if the AB glue layer, as an indirect mounting plane for resistance strain gauge, remains sufficiently conformable to the complex surface of the cable, so the dynamic change of the axial strain of the cable caused by the vibration of the cable can be measured by the resistance strain gauge mounted on the AB glue layer, the resistance strain gauge can measure the natural frequency of the cable, and then evaluate the existing cable force of the cable.
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Lo, Jih-Hung, and 羅日宏. "DESIGN AND FABRICATION OF BRIDGE TYPE CHANNEL WAVEGUIDES BASED ON SILICON (100) SUBSTRATE." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/83190996789364624138.
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碩士大同大學
光電工程研究所
91
We take the substrate structure of silicon of (100) to fabricate the channel waveguides by ICP-RIE dry etching system. In the dry etching process, we point in relation of the etching masks with the etching limit time, the etching rate with the different etching gases and etching profile with composition of etching gases. Then, we are using depositing, lapping and lithography technology to fabricate the bridge type channel waveguides. In recent years, due to the progress of integrated optics (IO) technology and the requirement of scaling-down device dimension, precise line-width control becomes one of the essential issues of modern integrated optics technology. Among those process demands, the anisotropic property and the selectivity of such etching materials become very critical and important but the traditional wet etching technique and conventional plasma etching method can not meet the requirement anymore. In this study we use Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE) system. We get the best etching rate 1.23 μm/min and etching depth 12.3μm by using etching gas composition SF6/ Ar.
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Chen, Chien-Liang, and 陳建良. "A Frequency-Conversion Half-Bridge Induction Type Heating System for Magnetic Nanoparticle Thermotherapy." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/58339681587057216262.
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碩士國立成功大學
電機工程學系碩博士班
95
The Bio-research with small particles in AC magnetic fields was started in the late 1950s. Since the process of magnetic particles has progressed to nanoscale in the last decade, the related researches are doing tumor thermotherapy in human body with magnetic nanoparticles. The main idea is to use the magnetic nanoparticles which are packaged with lipid and drug to attach to specific cancer cells. The temperature of magnetic particles is risen by absorbing magnetic energy from external AC magnetic fields. The heat can make the good curative effects to cancer cells from drugs-bearing magnetic particles. And the high temperature can inhibit the development of cancer cells. Up to present, the thermotherapy researches of magnetic particles almost experiment with single or few frequencies of magnetic filed. So the focus of our research is to design the heating system to heat the magnetic particles. We design a half-bridge resonance circuit which can be set with different operation frequencies to generate the AC magnetic filed. The heating system can also control the amplitude of the generated magnetic field. Finally, we use the Finite-Element Method and circuit simulation software to simulate the half-bridge resonance circuit and compare the results with the practical heating system. The heating efficiency of nanoparticle under different heating frequencies is also studied.
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Yang, Da-Wei, and 楊大為. "Design and Implementation of LLC-type Half-Bridge Converter for Contactless Battery Charger." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/91529629641837341692.
Full textAbstract:
碩士中原大學
電機工程研究所
98
To charge electronic products, a conduct-type charging by means of metal contact connections is mostly adopted in traditional chargers. However, both the contact points and the exposure of the charger connector cause the vulnerability as well as the corrosion of metal. In certain environments, the use of conduct-type charging has become pretty dangerous. In regard to safety concerns, the non-contact inductive charging technology has therefore arisen. To keep pace with the cutting-edge technology, this thesis will probe into the application of the non-contact inductive power charging technology. In this thesis, a half-bridge inverter is employed. The transformer magnetizing inductance as well as the leakage inductance is used to carry out resonance. The switch with zero voltage switching (ZVS) achieves the goals of reducing the stresses of components, the losses in switching , and the electromagnetic interference. Furthermore, the use of resonant circuit enhance the overall efficiency. A 90W non-contact charger with DC 270V input and 12V output voltage, is implemented in this thesis. In a full loaded condition, while an air gap is 0.15mm, the system efficiency is 75.42%. The system efficiency is 60.17% at the maximum air gap of 0.75mm.