Modeling of shape memory alloys with plasticity

Shape memory alloys are a special class of metals that can undergo large deformation yet still be able to recover their original shape through the mechanism of phase transformations. However, when they experience plastic slip, their ability to recover their original shape is reduced. This is due to the presence of dislocations generated by plastic flow that interfere with shape recovery through the shape memory effect and the superelastic effect. A one-dimensional model that captures the coupling between shape memory effect, the superelastic effect and plastic deformation is introduced. The shape memory alloy is assumed to have only 3 phases: austenite, positive variant martensite and negative variant martensite. If the SMA flows plastically, each phase will exhibit a dislocation field that permanently prevents a portion of it from being transformed back to other phases. Hence, less of the phase is available for subsequent phase transformations. A constitutive model was developed to depict this phenomena and simulate the effect of plasticity on both the shape memory effect and the superelastic effect in shape memory alloys. In addition, experimental tests were conducted to characterize the phenomenon in shape memory wire and superelastic wire. ^ The constitutive model was then implemented in within a finite element context as UMAT (User MATerial Subroutine) for the commercial finite element package ABAQUS. The model is phenomenological in nature and is based on the construction of stress-temperature phase diagram. ^ The model has been shown to be capable of capturing the qualitative and quantitative aspects of the coupling between plasticity and the shape memory effect and plasticity and the super elastic effect within acceptable limits. As a verification case a simple truss structure was built and tested and then simulated using the FEA constitutive model. The results where found to be close the experimental data. ^

Political economy of Caribbean drug trafficking: The case of the Dominican Republic

The purpose of this dissertation was to examine the relationship between narcotics trafficking and the processes of economic liberalization and democratization in the Caribbean. The salient social, political and economic processes were explored at each juncture of the drug trafficking chain to determine why certain groups and locales became integrated in the global narcotics economy. It also considered the national security implications of the global narcotics economy. ^ The Global Commodity Chain framework allowed the study to examine the social, political and economic processes that determine how a commodity is produced, transported, distributed and consumed in the global economy. A case study method was used to specify the commodity (cocaine) and locations (U.S. and Dominican Republic) where these processes were examined. ^ The important contributing factors in the study included: a liberalizing global economy, the social processes of migration, the formation of enclaves in the U.S., the opening of the political process and institutional weakness in the country of origin. All of these factors contributed to the Dominican Republic and Dominican migrants becoming key players in the cocaine commodity chain. It concluded that narcotics trafficking as a national security issue remains a fluid concept, contingent on specific cultural and historic antecedents. ^

Investigative interviewing and memory: How accurate are interviewers recollections of investigative interviews?

Contrary to interviewing guidelines, a considerable portion of witness interviews are not recorded. Investigators��� memory, their interview notes, and any subsequent interview reports therefore become important pieces of evidence; the accuracy of interviewers��� memory or such reports is therefore of crucial importance when interviewers testify in court regarding witness interviews. A detailed recollection of the actual exchange during such interviews and how information was elicited from the witness will allow for a better assessment of statement veracity in court. ^ Two studies were designed to examine interviewers��� memory for a prior witness interview. Study One varied interviewer note-taking and type of subsequent interview report written by interviewers by including a sample of undergraduates and implementing a two-week delay between interview and recall. Study Two varied levels of interviewing experience in addition to report type and note-taking by comparing experienced police interviewers to a student sample. Participants interviewed a mock witness about a crime, while taking notes or not, and wrote an interview report two weeks later (Study One) or immediately after (Study Two). Interview reports were written either in a summarized format, which asked interviewers for a summary of everything that occurred during the interview, or verbatim format, which asked interviewers to record in transcript format the questions they asked and the witness���s responses. Interviews were videotaped and transcribed. Transcriptions were compared to interview reports to score for accuracy and omission of interview content. ^ Results from both studies indicate that much interview information is lost between interview and report especially after a two-week delay. The majority of information reported by interviewers is accurate, although even interviewers who recalled information immediately after still reported a troubling amount of inaccurate information. Note-taking was found to increase accuracy and completeness of interviewer reports especially after a two week delay. Report type only influenced recall of interviewer questions. Experienced police interviewers were not any better at recalling a prior witness interview than student interviewers. Results emphasize the need to record witness interviews to allow for more accurate and complete interview reconstruction by interviewers, even if interview notes are available. ^

Study of carbon nanotube film and shape memory alloys treatment for sensing and structural vibration control

Structural vibration control is of great importance. Current active and passive vibration control strategies usually employ individual elements to fulfill this task, such as viscoelastic patches for providing damping, transducers for picking up signals and actuators for inputting actuating forces. The goal of this dissertation work is to design, manufacture, investigate and apply a new type of multifunctional composite material for structural vibration control. This new composite, which is based on multi-walled carbon nanotube (MWCNT) film, is potentially to function as free layer damping treatment and strain sensor simultaneously. That is, the new material integrates the transducer and the damping patch into one element. The multifunctional composite was prepared by sandwiching the MWCNT film between two adhesive layers. Static sensing test indicated that the MWCNT film sensor resistance changes almost linearly with the applied load. Sensor sensitivity factors were comparable to those of the foil strain gauges. Dynamic test indicated that the MWCNT film sensor can outperform the foil strain gage in high frequency ranges. Temperature test indicated the MWCNT sensor had good temperature stability over the range of 237 K-363 K. The Young���s modulus and shear modulus of the MWCNT film composite were acquired by nanoindentation test and direct shear test, respectively. A free vibration damping test indicated that the MWCNT composite sensor can also provide good damping without adding excessive weight to the base structure. A new model for sandwich structural vibration control was then proposed. In this new configuration, a cantilever beam covered with MWCNT composite on top and one layer of shape memory alloy (SMA) on the bottom was used to illustrate this concept. The MWCNT composite simultaneously serves as free layer damping and strain sensor, and the SMA acts as actuator. Simple on-off controller was designed for controlling the temperature of the SMA so as to control the SMA recovery stress as input and the system stiffness. Both free and forced vibrations were analyzed. Simulation work showed that this new configuration for sandwich structural vibration control was successful especially for low frequency system.

On Record: Soundscapes as Metaphor and Physical Manifestation of Memory in Early Holocaust Novels and Contemporary Criticism

This thesis compares two perspectives on the production of Holocaust memory: a novel that leads up to The Holocaust in Britain and one that reflects the hindsight perspective of a liberator in the Soviet Union. The novels are Virginia Woolf���s BETWEEN THE ACTS and Vasily Grossman���s LIFE AND FATE. The analysis offers a locus of analysis for the diasporic literary energy created by the catastrophe in the 20th and 21st centuries. The project offers a theorized standpoint on the role of literature on official historical archives. Proposing a method through which contemporary readers can engage the diasporic event of The Holocaust, the project adopts both the extended metaphor and literal expression of soundscapes. Soundscapes encompass the immaterial processes of memorialization and the literal sonic textures developed in Holocaust novels. The critical perspective incorporates contemporary notions of narratology, archival practices, and cultural manifestations of language into the notion of literary ethnomusicology.

Investigative Interviewing and Memory: How Accurate Are Interviewers��� Recollections of Investigative Interviews?

Contrary to interviewing guidelines, a considerable portion of witness interviews are not recorded. Investigators��� memory, their interview notes, and any subsequent interview reports therefore become important pieces of evidence; the accuracy of interviewers��� memory or such reports is therefore of crucial importance when interviewers testify in court regarding witness interviews. A detailed recollection of the actual exchange during such interviews and how information was elicited from the witness will allow for a better assessment of statement veracity in court. Two studies were designed to examine interviewers��� memory for a prior witness interview. Study One varied interviewer note-taking and type of subsequent interview report written by interviewers by including a sample of undergraduates and implementing a two-week delay between interview and recall. Study Two varied levels of interviewing experience in addition to report type and note-taking by comparing experienced police interviewers to a student sample. Participants interviewed a mock witness about a crime, while taking notes or not, and wrote an interview report two weeks later (Study One) or immediately after (Study Two). Interview reports were written either in a summarized format, which asked interviewers for a summary of everything that occurred during the interview, or verbatim format, which asked interviewers to record in transcript format the questions they asked and the witness���s responses. Interviews were videotaped and transcribed. Transcriptions were compared to interview reports to score for accuracy and omission of interview content. Results from both studies indicate that much interview information is lost between interview and report especially after a two-week delay. The majority of information reported by interviewers is accurate, although even interviewers who recalled information immediately after still reported a troubling amount of inaccurate information. Note-taking was found to increase accuracy and completeness of interviewer reports especially after a two week delay. Report type only influenced recall of interviewer questions. Experienced police interviewers were not any better at recalling a prior witness interview than student interviewers. Results emphasize the need to record witness interviews to allow for more accurate and complete interview reconstruction by interviewers, even if interview notes are available.

The acculturation of middle income Hispanic households

Research on the consumer behavior of the Hispanic population has recently attracted the attention of marketing practitioners as well as researchers. This study's purpose was to develop a model and scales to examine the acculturation process of Hispanic consumers with income levels of $35,000 and above, and its effects on their consumer behavior. The proposed model defined acculturation as a bilinear and multidimensional change process, measuring consumers' selective change process in four dimensions: language preference, Hispanic identification, American identification, and familism. A national sample of 653 consumers was analyzed. The scales developed for testing the model showed good to high internal consistency and adequate concurrent validity. According to the results, consumers' contact with Hispanic and Anglo acculturation agents generates change or reinforces consumers' language preferences. Language preference fully mediates the effects of the agents on consumers' American identification and familism; however, the effects of the acculturation agents on Hispanic identification are only partially mediated by individuals' language preference change. It was proposed that the acculturation process would have an effect on consumers' brand loyalty, attitudes towards high quality and prestigious brands, purchase frequency, and savings allocation for their children. Given the lack of significant differences between Hispanic and Anglo consumers and among Hispanic generations, only savings allocation for children's future was studied intensively. According to these results, Hispanic consumers' savings for their children is affected by consumers' language preference through their ethnic identification and familism. No moderating effects were found for consumers' gender, age, and country of origin, suggesting that individual differences do not affect consumers' acculturation process. Additionally, the effects of familism were tested among ethnic groups. The results suggest not only that familism discriminates among Hispanic and Anglo consumers, but also is a significant predictor of consumers' brand loyalty, brand quality attitudes, and savings allocation. Three acculturation segments were obtained through cluster analysis: bicultural, high acculturation, and low acculturation groups, supporting the biculturalism proposition. ^

Parental involvement: Its relation to achievement in a multiethnic sample of newly immigrated students

The current study examined how parental involvement is related to the academic adaptation and performance of a multiethnic sample of newly immigrant students from South America and the Caribbean---Argentina, Colombia, Cuba, Haiti, and English-speaking Caribbean countries. Six hundred twenty-two participants attending elementary, middle and high school in Miami-Dade and Broward Counties were interviewed during two consecutive years at their respective schools. Parents completed surveys at home and returned them by mail. ^ Three forms of parent involvement were chosen as predictor variables---(1) parental contact and communication with school, (2) parental monitoring of children's school-related activities at home, and (3) parental expectations regarding children's academic achievement. Academic performance indicators obtained from school records were students' grade point averages for math and reading (GPA), FCAT-SSS (Florida Comprehensive Assessment Test-Sunshine State Standards) scores, and FCAT-NRT (Norm Referenced Test) scores. Hypotheses were (a) that the forms of parent involvement would differ across the different cultural groups and (b) that parent involvement would relate to students' achievement, regardless of the specific form of involvement. ^ Results indicated that Cuban and Colombian parents differed significantly in terms of monitoring school-related activities of their children and had higher expectations for their children than Haitian, West-Indian, or Argentinean parents. Cuban parents were more likely to be actively engaged in communication with their children's schools than parents of the other ethnic groups. Multiple regression analyses indicated that the three forms of parent involvement accounted for a significant proportion of GPA and FCAT-SSS scores, after controlling for the effects of demographic variables---grade level, gender, and ethnicity. Given interactions of the parent involvement variables by country of origin for GPA, separate analyses indicated that parent involvement appeared to be most effective for Cubans and West Indians. Results are discussed in terms of the need for experimental intervention studies to identify causal relationships between parent involvement and academic achievement. ^

The effects of intellectual property rights on knowledge spillovers and innovation: An empirical investigation

FDI is believed to be a conduit of new technologies between countries. The first chapter of this dissertation studies the advantages of outward FDI for the home country of multinationals conducting research and development abroad. We use patent citations as a proxy for technology spillovers and we bring empirical evidence that supports the hypothesis that a U.S. subsidiary conducting research and development overseas facilitates the flow of knowledge between its host and home countries.^ The second chapter examines the impact of intellectual property rights (IPR) reforms on the technology flows between the U.S. and host countries of U.S. affiliates. We again use patent citations to examine whether the diffusion of new technology between the host countries and the U.S. is accelerated by the reforms. Our results suggest that the reforms favor innovative efforts of domestic firms in the reforming countries rather than U.S. affiliates efforts. In other words, reforms mediate the technology flows from the U.S. to the reforming countries.^ The third chapter deals with another form of IPR, open source (OS) licenses. These differ in the conditions under which licensors and OS contributors are allowed to modify and redistribute the source code. We measure OS project quality by the speed with which programming bugs are fixed and test whether the license chosen by project leaders influences bug resolution rates. In initial regressions, we find a strong correlation between the hazard of bug resolution and the use of highly restrictive licenses. However, license choices are likely to be endogenous. We instrument license choice using (i) the human language in which contributors operate and (ii) the license choice of the project leaders for a previous project. We then find weak evidence that restrictive licenses adversely affect project success.^

Trojan horses: On the origins of national security concerns over foreign investments in the United States from 1919 to 2008

In this thesis I sought to explain the origins of national security concerns over foreign investments in the United States from 1919 to 2008. I identified and examined 29 cases of national security concerns over foreign investments in the United States during that period, and argued that in order to understand the circumstances under which foreign investments in the United States are perceived to be threats to the U.S. security we must rely on a combination of democratic peace theory and the version of political realism known as power transition theory. Thus, I tested the argument that national security concerns over foreign investments in the United States from 1919 to 2008 resulted from: (1) perceptions of international power transition, (2) perceptions of ideological and institutional differences between the United States and the home country of the investor, (3) perceptions of the strategic importance of the sector where the investment is made, and (4) perceptions of participation or control of the foreign investor by the government of the country of origin. I found that all these hypotheses have some explanatory power.

The impact of institutional complexity and top management characteristics on executive compensation and firm performance

While most studies take a dyadic view when examining the environmental difference between the home country of a multinational enterprise (MNE) and a particular foreign country, they ignore that an MNE is managing a network of subsidiaries embedded in diverse environments. Additionally, neither the impacts of global environments on top executives nor the effects of top executives��� capabilities to handle institutional complexity are fully explored. Thus, using a three-essay format, this dissertation tried to fill these gaps by addressing the effects of institutional complexity and top management characteristics on top executive compensation and firm performance. ^ Essay 1 investigated the impact of an MNE���s institutional complexity, or the diversity of national institutions facing an MNE���s network of subsidiaries, on the top management team (TMT) compensation. This essay proposed that greater political and cultural complexity leads to not only greater TMT total compensation but also to a greater portion of TMT compensation linked with long-term performance. The arguments are supported in this essay by using an unbalanced panel dataset including 296 U.S. firms with 1,340 observations. ^ Essay 2 explored TMT social capital and its moderating role on value creation and appropriation by the chief executive officer (CEO). Using a sample with 548 U.S. firms and 2,010 observations, it found that greater TMT social capital does facilitate the effects of CEO intellectual capital and social capital on firm growth. Finally, essay 3 examined the performance implications for the fit between managerial information-processing capabilities and institutional complexity. It proposed that institutional complexity is associated with the needs of information-processing. On the other hand, smaller TMT turnover and larger TMT size reflect larger managerial information-processing capabilities. Consequently, superior performance is achieved by the match among institutional complexity, TMT turnover, and TMT size. All hypotheses in essay 3 are supported in a sample of 301 U.S. firms and 1,404 observations. ^ To conclude, this dissertation advances and extends our knowledge on the roles of institutional environments and top executives on firm performance and top executive compensation.^

A theoretical analysis of eyewitness identification: Dual -process theory, signal detection theory and eyewitness confidence

Given the growing number of wrongful convictions involving faulty eyewitness evidence and the strong reliance by jurors on eyewitness testimony, researchers have sought to develop safeguards to decrease erroneous identifications. While decades of eyewitness research have led to numerous recommendations for the collection of eyewitness evidence, less is known regarding the psychological processes that govern identification responses. The purpose of the current research was to expand the theoretical knowledge of eyewitness identification decisions by exploring two separate memory theories: signal detection theory and dual-process theory. This was accomplished by examining both system and estimator variables in the context of a novel lineup recognition paradigm. Both theories were also examined in conjunction with confidence to determine whether it might add significantly to the understanding of eyewitness memory. ^ In two separate experiments, both an encoding and a retrieval-based manipulation were chosen to examine the application of theory to eyewitness identification decisions. Dual-process estimates were measured through the use of remember-know judgments (Gardiner & Richardson-Klavehn, 2000). In Experiment 1, the effects of divided attention and lineup presentation format (simultaneous vs. sequential) were examined. In Experiment 2, perceptual distance and lineup response deadline were examined. Overall, the results indicated that discrimination and remember judgments (recollection) were generally affected by variations in encoding quality and response criterion and know judgments (familiarity) were generally affected by variations in retrieval options. Specifically, as encoding quality improved, discrimination ability and judgments of recollection increased; and as the retrieval task became more difficult there was a shift toward lenient choosing and more reliance on familiarity. ^ The application of signal detection theory and dual-process theory in the current experiments produced predictable results on both system and estimator variables. These theories were also compared to measures of general confidence, calibration, and diagnosticity. The application of the additional confidence measures in conjunction with signal detection theory and dual-process theory gave a more in-depth explanation than either theory alone. Therefore, the general conclusion is that eyewitness identifications can be understood in a more complete manor by applying theory and examining confidence. Future directions and policy implications are discussed. ^

Implicit eyewitness memory

After a crime has occurred, one of the most pressing objectives for investigators is to identify and interview any eyewitness that can provide information about the crime. Depending on his or her training, the investigative interviewer will use (to varying degrees) mostly yes/no questions, some cued and multiple-choice questions, with few open-ended questions. When the witness cannot generate any more details about the crime, one assumes the eyewitness' memory for the critical event has been exhausted. However, given what we know about memory, is this a safe assumption? In line with the extant literature on human cognition, if one assumes (a) an eyewitness has more available memories of the crime than he or she has accessible and (b) only explicit probes have been used to elicit information, then one can argue this eyewitness may still be able to provide additional information via implicit memory tests. In accordance with these notions, the present study had two goals: demonstrate that (1) eyewitnesses can reveal memory implicitly for a detail-rich event and (2) particularly for brief crimes, eyewitnesses can reveal memory for event details implicitly that were inaccessible when probed for explicitly. Undergraduates (N = 227) participated in a psychological experiment in exchange for research credit. Participants were presented with one of three stimulus videos (brief crime vs. long crime vs. irrelevant video). Then, participants either completed a series of implicit memory tasks or worked on a puzzle for 5 minutes. Lastly, participants were interviewed explicitly about the previous video via free recall and recognition tasks. Findings indicated that participants who viewed the brief crime provided significantly more crime-related details implicitly than those who viewed the long crime. The data also showed participants who viewed the long crime provided marginally more accurate details during free recall than participants who viewed the brief crime. Furthermore, participants who completed the implicit memory tasks provided significantly less accurate information during the explicit interview than participants who were not given implicit memory tasks. This study was the first to investigate implicit memory for eyewitnesses of a crime. To determine its applied value, additional empirical work is required.

Aspects Allogenic Memory in the Gorgonian Coral Swiftia Exserta

Accelerated graft rejection can be used to determine immune memory in the gorgonian coral swiftia exserta. The extent ofthe persistence of immune memory will be determined in this experiment using replicate sets that are time elapsed from 1, 3, and 6 month. Although corals lack circulatory systems which can be a component of adaptive systemic immunity, this study will attempt to determine whether this gorgonian coral is capable of transmitting immune information throughout its colonial body. Results showed that at each of the time points; one, three, and six months the secondary response group and the primary response group were significantly different (at p=0.001) therefore, demonstrating long term immune memory. While the primary response group and the 3rd party specificity response group were similar, both were significantly different (at p=O. 001) from the secondary response group which shows the response to be specific, with memory applicable to the original antigen. Systemic immunity was not determined to be present for 15 em and one week after initial sensitization.

Neglected Masterpieces of Cinema

This article will acquaint you with ten of the more important leftwing films I have reviewed over the past sixteen years as a member of New York Film Critics Online. You will not see listed familiar works such as ���The Battle of Algiers��� but instead those that deserve wider attention, the proverbial neglected masterpieces. They originate from different countries and are available through Internet streaming, either freely from Youtube or through Netflix or Amazon rental. In several instances you will be referred to film club websites that like the films under discussion deserve wider attention since they are the counterparts to the small, independent theaters where such films get premiered. The country of origin, date and director will be identified next to the title, followed by a summary of the film, and finally by its availability.