Matching Items (13)
Filtering by
- All Subjects: Performance
- Creators: Srinivasan, Devarajan
- Creators: Rogers, Rodney
Description
ABSTRACT As the use of photovoltaic (PV) modules in large power plants continues to increase globally, more studies on degradation, reliability, failure modes, and mechanisms of field aged modules are needed to predict module life expectancy based on accelerated lifetime testing of PV modules. In this work, a 26+ year old PV power plant in Phoenix, Arizona has been evaluated for performance, reliability, and durability. The PV power plant, called Solar One, is owned and operated by John F. Long's homeowners association. It is a 200 kWdc, standard test conditions (STC) rated power plant comprised of 4000 PV modules or frameless laminates, in 100 panel groups (rated at 175 kWac). The power plant is made of two center-tapped bipolar arrays, the north array and the south array. Due to a limited time frame to execute this large project, this work was performed by two masters students (Jonathan Belmont and Kolapo Olakonu) and the test results are presented in two masters theses. This thesis presents the results obtained on the south array and the other thesis presents the results obtained on the north array. Each of these two arrays is made of four sub arrays, the east sub arrays (positive and negative polarities) and the west sub arrays (positive and negative polarities), making up eight sub arrays. The evaluation and analyses of the power plant included in this thesis consists of: visual inspection, electrical performance measurements, and infrared thermography. A possible presence of potential induced degradation (PID) due to potential difference between ground and strings was also investigated. Some installation practices were also studied and found to contribute to the power loss observed in this investigation. The power output measured in 2011 for all eight sub arrays at STC is approximately 76 kWdc and represents a power loss of 62% (from 200 kW to 76 kW) over 26+ years. The 2011 measured power output for the four south sub arrays at STC is 39 kWdc and represents a power loss of 61% (from 100 kW to 39 kW) over 26+ years. Encapsulation browning and non-cell interconnect ribbon breakages were determined to be the primary causes for the power loss.
ContributorsOlakonu, Kolapo (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2012
Description
New works for the bass clarinet as a solo instrument are uncommon. In the interest of expanding the repertoire of the bass clarinet, three new works for bass clarinet were commissioned from three different composers, all with different instrumentations. The resulting works are Industrial Strength for bass clarinet and piano by Kenji Bunch; Dark Embers for two bass clarinets by Theresa Martin; and Shovelhead for bass clarinet and interactive electronics by Steven Snowden. Although all three works feature the bass clarinet, they are all very different and pose unique challenges to the performer. To accompany these pieces, and as an aid to future performers, a performance practice guide has been included with recommendations for individuals who wish to perform these works. Included in the guide are recommended fingerings, practice techniques, and possible adjustments to the bass clarinet parts designed in collaboration with the composers that make the works more technically accessible. Accompanying this guide are full scores of all three works, a recording of them performed by the author, and a chart that contains recommended altissimo fingerings.
ContributorsMiracle, Matthew (Author) / Spring, Robert (Thesis advisor) / Gardner, Joshua (Committee member) / Holbrook, Amy (Committee member) / Micklich, Albie (Committee member) / Rogers, Rodney (Committee member) / Arizona State University (Publisher)
Created2012
Description
The purpose of this research paper is to discuss John Carter's Cantata, the musical development of this composition, and provide a brief history of this African American musician and composer. Presently, there exists very little research regarding Carter's life and compositions. From a musician's perspective, this paper discusses the challenges of singing and performing the Cantata for future performers and provides a reference for their preparation. This project also examines John Carter's musical style and analyzes the structure of the Cantata. African-American folk songs were an inspiration to Carter's compositions, especially this particular work. As an African-American, his life and background played a role in his inspiration of composition. With borrowed music, he reveals a basic truth about this period of American history; how the lives of slaves influenced in the development of this particular genre. Additionally, John Carter's style of composition is examined, including the application of jazz and modal scales in his Cantata. Performance practice is examined for both the singer and pianist in a way that best represents the composer's original and unique intent. From vocal safety to breath control, a singer may find several challenges when performing this eclectic piece. This paper provides a guide for singers. A brief overview of the pianist's role in the Cantata is also included. Characteristic words of the African-American vernacular found in Carter's Cantata are briefly discussed and identified (i.e. "them" vs. "dem"). It is essential that any performer, both beginning and advanced, should have a proper understanding of the concepts that Carter had so carefully crafted. This paper endeavors to provide a deeper sense of understanding to what Carter had intended for both the performer and the listener.
ContributorsNa, Bora (Author) / Britton, David (Thesis advisor) / Bush, Jeffrey (Committee member) / Campbell, Andrew (Committee member) / Rogers, Rodney (Committee member) / Ryan, Russell (Committee member) / Arizona State University (Publisher)
Created2012
Description
Photovoltaic (PV) modules undergo performance degradation depending on climatic conditions, applications, and system configurations. The performance degradation prediction of PV modules is primarily based on Accelerated Life Testing (ALT) procedures. In order to further strengthen the ALT process, additional investigation of the power degradation of field aged PV modules in various configurations is required. A detailed investigation of 1,900 field aged (12-18 years) PV modules deployed in a power plant application was conducted for this study. Analysis was based on the current-voltage (I-V) measurement of all the 1,900 modules individually. I-V curve data of individual modules formed the basis for calculating the performance degradation of the modules. The percentage performance degradation and rates of degradation were compared to an earlier study done at the same plant. The current research was primarily focused on identifying the extent of potential induced degradation (PID) of individual modules with reference to the negative ground potential. To investigate this, the arrangement and connection of the individual modules/strings was examined in detail. The study also examined the extent of underperformance of every series string due to performance mismatch of individual modules in that string. The power loss due to individual module degradation and module mismatch at string level was then compared to the rated value.
ContributorsJaspreet Singh (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2011
Characterization and analysis of long term field aged photovoltaic modules and encapsulant materials
Description
Photovoltaic (PV) module degradation is a well-known issue, however understanding the mechanistic pathways in which modules degrade is still a major task for the PV industry. In order to study the mechanisms responsible for PV module degradation, the effects of these degradation mechanisms must be quantitatively measured to determine the severity of each degradation mode. In this thesis multiple modules from three climate zones (Arizona, California and Colorado) were investigated for a single module glass/polymer construction (Siemens M55) to determine the degree to which they had degraded, and the main factors that contributed to that degradation. To explain the loss in power, various nondestructive and destructive techniques were used to indicate possible causes of loss in performance. This is a two-part thesis. Part 1 presents non-destructive test results and analysis and Part 2 presents destructive test results and analysis.
ContributorsChicca, Matthew (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Rogers, Bradley (Committee member) / Srinivasan, Devarajan (Committee member) / Arizona State University (Publisher)
Created2015
Description
With the application of reverse osmosis (RO) membranes in the wastewater treatment and seawater desalination, the limitation of flux and fouling problems of RO have gained more attention from researchers. Because of the tunable structure and physicochemical properties of nanomaterials, it is a suitable material that can be used to incorporate with RO to change the membrane performances. Silver is biocidal, which has been used in a variety of consumer products. Recent studies showed that fabricating silver nanoparticles (AgNPs) on membrane surfaces can mitigate the biofouling problem on the membrane. Studies have shown that Ag released from the membrane in the form of either Ag ions or AgNP will accelerate the antimicrobial activity of the membrane. However, the silver release from the membrane will lower the silver loading on the membrane, which will eventually shorten the antimicrobial activity lifetime of the membrane. Therefore, the silver leaching amount is a crucial parameter that needs to be determined for every type of Ag composite membrane.
This study is attempting to compare four different silver leaching test methods, to study the silver leaching potential of the silver impregnated membranes, conducting the advantages and disadvantages of the leaching methods. An In-situ reduction Ag loaded RO membrane was examined in this study. A custom waterjet test was established to create a high-velocity water flow to test the silver leaching from the nanocomposite membrane in a relative extreme environment. The batch leaching test was examined as the most common leaching test method for the silver composite membrane. The cross-flow filtration and dead-end test were also examined to compare the silver leaching amounts.
The silver coated membrane used in this experiment has an initial silver loading of 2.0± 0.51 ug/cm2. The mass balance was conducted for all of the leaching tests. For the batch test, water jet test, and dead-end filtration, the mass balances are all within 100±25%, which is acceptable in this experiment because of the variance of the initial silver loading on the membranes. A bad silver mass balance was observed at cross-flow filtration. Both of AgNP and Ag ions leached in the solution was examined in this experiment. The concentration of total silver leaching into solutions from the four leaching tests are all below the Secondary Drinking Water Standard for silver which is 100 ppb. The cross-flow test is the most aggressive leaching method, which has more than 80% of silver leached from the membrane after 50 hours of the test. The water jet (54 ± 6.9% of silver remaining) can cause higher silver leaching than batch test (85 ± 1.2% of silver remaining) in one-hour, and it can also cause both AgNP and Ag ions leaching from the membrane, which is closer to the leaching condition in the cross-flow test.
This study is attempting to compare four different silver leaching test methods, to study the silver leaching potential of the silver impregnated membranes, conducting the advantages and disadvantages of the leaching methods. An In-situ reduction Ag loaded RO membrane was examined in this study. A custom waterjet test was established to create a high-velocity water flow to test the silver leaching from the nanocomposite membrane in a relative extreme environment. The batch leaching test was examined as the most common leaching test method for the silver composite membrane. The cross-flow filtration and dead-end test were also examined to compare the silver leaching amounts.
The silver coated membrane used in this experiment has an initial silver loading of 2.0± 0.51 ug/cm2. The mass balance was conducted for all of the leaching tests. For the batch test, water jet test, and dead-end filtration, the mass balances are all within 100±25%, which is acceptable in this experiment because of the variance of the initial silver loading on the membranes. A bad silver mass balance was observed at cross-flow filtration. Both of AgNP and Ag ions leached in the solution was examined in this experiment. The concentration of total silver leaching into solutions from the four leaching tests are all below the Secondary Drinking Water Standard for silver which is 100 ppb. The cross-flow test is the most aggressive leaching method, which has more than 80% of silver leached from the membrane after 50 hours of the test. The water jet (54 ± 6.9% of silver remaining) can cause higher silver leaching than batch test (85 ± 1.2% of silver remaining) in one-hour, and it can also cause both AgNP and Ag ions leaching from the membrane, which is closer to the leaching condition in the cross-flow test.
ContributorsHan, Bingru (Author) / Westerhoff, Paul (Thesis advisor) / Perreault, Francois (Committee member) / Sinha, Shahnawaz (Committee member) / Arizona State University (Publisher)
Created2017
Description
Despite the growth of technology in music composition and performance, professional clarinetists maintain that air microphones are superior to piezoelectric pickups. Pickups offer increased mobility, isolation, and reduced feedback, but air microphones are used simply for the perceived sound quality. In this study a ported barrel pickup and a contact transducer pickup placed at various intervals on the clarinet were sampled and compared to a reference recording to determine how the sound differed for each method. In addition, the history of wind instrument pickups, the acoustics of the clarinet, and the basics of piezoelectricity were discussed to help examine the results. The pickups were examined in three ways: overall level in decibels, frequency cutoff, and overtone displacement. Through these results it was determined that the most accurate methods of clarinet pickup are the ported barrel pickup, contact transducers closer to the vibration of the reed such as the ligature or barrel surface, or a transducer placed at the end of the bell. These findings were consistent with the discussions regarding history, clarinet acoustics, and piezoelectricity. This study also produced a reference for the sounds associated with different pickup methods, as well as possible improvements for clarinet pickup design.
ContributorsEnglert, Patrick William (Author) / Spring, Robert S (Thesis advisor) / Gardner, Joshua T (Thesis advisor) / Caslor, Jason (Committee member) / Rogers, Rodney (Committee member) / Arizona State University (Publisher)
Created2018
Description
The volume of end-of-life photovoltaic (PV) modules is increasing as the global PV market increases, and the global PV waste streams are expected to reach 250,000 metric tons by the end of 2020. If the recycling processes are not in place, there would be 60 million tons of end-of-life PV modules lying in the landfills by 2050, that may not become a not-so-sustainable way of sourcing energy since all PV modules could contain certain amount of toxic substances. Currently in the United States, PV modules are categorized as general waste and can be disposed in landfills. However, potential leaching of toxic chemicals and materials, if any, from broken end-of-life modules may pose health or environmental risks. There is no standard procedure to remove samples from PV modules for chemical toxicity testing in the Toxicity Characteristic Leaching Procedure (TCLP) laboratories as per EPA 1311 standard. The main objective of this thesis is to develop an unbiased sampling approach for the TCLP testing of PV modules. The TCLP testing was concentrated only for the laminate part of the modules, as they are already existing recycling technologies for the frame and junction box components of PV modules. Four different sample removal methods have been applied to the laminates of five different module manufacturers: coring approach, cell-cut approach, strip-cut approach, and hybrid approach. These removed samples were sent to two different TCLP laboratories, and TCLP results were tested for repeatability within a lab and reproducibility between the labs. The pros and cons of each sample removal method have been explored and the influence of sample removal methods on the variability of TCLP results has been discussed. To reduce the variability of TCLP results to an acceptable level, additional improvements in the coring approach, the best of the four tested options, are still needed.
ContributorsLeslie, Joswin (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Kuitche, Joseph (Committee member) / Arizona State University (Publisher)
Created2018
Description
In the past 10 to 15 years, there has been a tremendous increase in the amount of photovoltaic (PV) modules being both manufactured and installed in the field. Power plants in the hundreds of megawatts are continuously being turned online as the world turns toward greener and sustainable energy. Due to this fact and to calculate LCOE (levelized cost of energy), it is understandably becoming more important to comprehend the behavior of these systems as a whole by calculating two key data: the rate at which modules are degrading in the field; the trend (linear or nonlinear) in which the degradation is occurring. As opposed to periodical in field intrusive current-voltage (I-V) measurements, non-intrusive measurements are preferable to obtain these two key data since owners do not want to lose money by turning their systems off, as well as safety and breach of installer warranty terms. In order to understand the degradation behavior of PV systems, there is a need for highly accurate performance modeling. In this thesis 39 commercial PV power plants from the hot-dry climate of Arizona are analyzed to develop an understanding on the rate and trend of degradation seen by crystalline silicon PV modules. A total of three degradation rates were calculated for each power plant based on three methods: Performance Ratio (PR), Performance Index (PI), and raw kilowatt-hour. These methods were validated from in field I-V measurements obtained by Arizona State University Photovoltaic Reliability Lab (ASU-PRL). With the use of highly accurate performance models, the generated degradation rates may be used by the system owners to claim a warranty from PV module manufactures or other responsible parties.
ContributorsRaupp, Christopher (Author) / Tamizhmani, Govindasamy (Thesis advisor) / Srinivasan, Devarajan (Committee member) / Rogers, Bradley (Committee member) / Arizona State University (Publisher)
Created2016
Description
Since 1913, some of the world’s finest trumpeters have utilized the advantages of
specialized custom trumpets that can be played in multiple key centers through the operation of additional valves and slides. Merri Franquin (1848-1934), a leading trumpet teacher in twentieth-century Paris, patented two multiple-key trumpets: a four-piston- valve model that plays in the keys of C and D, and a five-piston-valve model that plays in the keys of A, B , C, and D. Thibouville-Lamy (1867-1969), a now-defunct French instrument company, built both models by adding extra valves and slides to three-valve C trumpets.
In the mid-1900s, top performers such as Roger Voisin, Armando Ghitalla, and David Hickman began using similar trumpets in performances and recordings. Regrettably, only a privileged few have had access to these instruments and the numerous advantages that they can provide. Thus, by reviewing and building upon current data on multiple-key trumpet design and performance, the author aims to unlock a vast potential for performance enhancement, waiting to be tapped by current and future trumpet performers.
specialized custom trumpets that can be played in multiple key centers through the operation of additional valves and slides. Merri Franquin (1848-1934), a leading trumpet teacher in twentieth-century Paris, patented two multiple-key trumpets: a four-piston- valve model that plays in the keys of C and D, and a five-piston-valve model that plays in the keys of A, B , C, and D. Thibouville-Lamy (1867-1969), a now-defunct French instrument company, built both models by adding extra valves and slides to three-valve C trumpets.
In the mid-1900s, top performers such as Roger Voisin, Armando Ghitalla, and David Hickman began using similar trumpets in performances and recordings. Regrettably, only a privileged few have had access to these instruments and the numerous advantages that they can provide. Thus, by reviewing and building upon current data on multiple-key trumpet design and performance, the author aims to unlock a vast potential for performance enhancement, waiting to be tapped by current and future trumpet performers.
ContributorsEwing, Bryan Christopher (Author) / Hickman, David (Thesis advisor) / Humphreys, Jere T (Committee member) / Rogers, Rodney (Committee member) / Arizona State University (Publisher)
Created2016