bluuebunny/crossref_metadata_2025 huggingface dataset:
The effectiveness of psychotherapy and its social context
Authors:   , Sivieri Gino Joseph
Published: July 2024

A review of the development of psychotherapy and clinical psychology is presented with an emphasis on their social-historical context. Through this review, clinical psychology's identification with scientific research as a defining feature of this independent profession is documented. It is noted that clinical psychology's research interests and growing involvement with the practice of therapy led to the professions' association with research-backed practice. Thus, when growing social-economic and legal concerns required evidence for the effectiveness of psychotherapy, the burden of proof fell largely on psychology. However, while practitioners have apparently paid little attention to applying often ambiguous research findings, policy makers have given them much emphasis. Unintended consequences of this situation are discussed. Many of these consequences are seen as attributable to characteristics of the scientific model adopted by psychology. Particularly salient features of this model include its conception of research as value-free and its neglect of social and cultural factors. It is concluded that clinical psychology developed an over-identification with a narrow conception of research which, when confronted with new demands, led to an identity crisis. Resolution of this crisis requires a broadening of identity such that clinical psychology is seen as a helping profession dealing with an enduring area of human need with few precise characteristics. A broader identity allows for an expanded view of science, as well as an appreciation of human values and respect for the influence of social context.
Characterization of humoral immune responses directed to the epidermal growth factor-like-domains of the merozoite surface protein-1 from Plasmodium Yoelii Yoelii 17XL
Authors:   , Calvo Paul Anthony
Published: July 2024

The merozoite surface protein-1 (MSP-1) is a leading candidate for a vaccine targeted at the erythrocytic stages of malarial parasite development. Recently, there has been increasing interest in this polypeptide, particularly in the carboxyl-terminal EGF-like domains. We have previously shown that this region from the rodent model Plasmodium yoelii, when expressed in native configuration, could immunize mice against an otherwise lethal challenge infection. In this model system, protection appears predominantly mediated by antibodies. In all rodent immunization studies to date, however, the immunogen has contained both of the postulated EGF-like domains. Firstly, we report on the efficacy of immunization with the individual EGF-like domains from P. yoelii in elicitation of a protective host response. Although all animals developed some level of antibody in response to the various immunogens, only those animals immunized with both EGF-like domains produced antibodies which could recognize the native MSP-1 molecule. Antibodies generated against the individual EGF-like domains did cross-react with the double EGF-like domain structure, suggesting the immunogens had retained elements of native configuration. In addition, only those animals which generated antibodies capable of recognizing native MSP-1 showed any level of protection from challenge infection. Secondly, through the characterization of protective versus non-protective animals, we report on criteria of humoral immunity which appear to correlate with in vivo protection. Using variably protected mice which differed only in their major histocompatibility complex haplotypes, we demonstrate that antibodies having high avidity and titer, with the correct specificity, in response to both EGF-like domains, positively correlate with protection. In particular, these characteristics associated with antibodies generated against the double-EGF-like domain structure, as opposed to either of the individual domains alone displayed the most significant correlation with in vivo protection. These results, taken together, suggest that determinants unique to the double EGF-like domain structure may be necessary for the generation of antibodies specific for the native configuration of MSP-1, and that these antibodies play a significant role in protection.
Design, optimization, and implementation of a universal FFT processor
Authors:   , Kumhom Pinit , Johnson Jeremy Russell , Nagvajara Prawat
Published: July 2024

There exist Fast Fourier transform (FFT) algorithms, called dimensionless FFTs1, that work independent of dimension. These algorithms can be configured to compute different dimensional discrete Fourier transforms (DFTs) simply by relabeling the input data and by changing the values of the twiddle factors occurring in the butterfly operations. This observation allows the design of a universal FFT processor, which with minor reconfiguring, can compute one, two, and three dimensional DFTs. In this thesis a family of FFT processors, parameterized by the number of points, the dimension, the number of processors, and the internal dataflow is designed. Mathematical properties of the FFT are used systematically to simplify and optimize the processor design, and to explore different algorithms and design choices. Different dimensionless FFTs have different dataflows and consequently lead to different performance characteristics. A performance model is used to evaluate the different algorithmic choices and their resulting dataflow. Using the performance model, a search was conducted to find the optimal algorithm for the family of processors considered. The resulting algorithm and corresponding hardware design was implemented using FPGA. 1L. Auslander, J. Johnson and R. Johnson, Dimensionless Fast Fourier Transform Method and Apparatus, Patent #US5003056, issued Dec. 14, 1999.
Kinetic micromethod for measuring the solubility of native and mutant sickle hemoglobin
Authors:   , Liao Dan
Published: July 2024

We have developed a photolytic method to determine the concentration of reactive hemes in a solution in the presence of a trace amount of CO. By measurement of the bimolecular rate of CO binding, and by calibration of the rate constant under equivalent conditions, the concentration of the reactive hemes can be determined. In a solution of sickle hemoglobin, the molecules in the gel contribute negligibly to the recombination rate, allowing the concentration of the molecules in the solution phase to be determined. To optimize signal to noise, modulated excitation methods were employed, although the method could also be used with pulse techniques and suitable signal averaging. Because the optical method employs a microspectrophotometer, only a few microliters of concentrated hemoglobin solution is required to reproduce the entire temperature dependence of the solubility previously determined by centrifugation using milliliter quantities of solutions of the same concentration. This should be especially useful for studies of site-directed mutants, and we present results obtained on the double mutant HbS [beta]L88A, HbS [beta]T87L, HbS [beta]K95I. The free energy difference in the polymerization of the double mutant HbS [beta]L88A is consistent with known differences in the amino acid hydrophobicities. The calibration required for these experiments also provides an excellent determination of the activation energy for binding the first CO to deoxy hemoglobin. The solubilities of other HbS double mutant HbS [beta]T87L, HbS [beta]K95I were also measured. The solubility of HbS [beta]K95I was found much higher than that of native HbS. Nonlinear effect for thick samples like HbS [beta]K95I gave a reasonable explanation of extraordinary results on calculated initial concentration. The solubility of HbS [beta]T87L was found close to that of native HbS.
Examining Emotions and Comparing the EsSense Profile® and Coffee Drinking Experience in Coffee Drinkers in Philadelphia
Authors:   , Kanjanakorn Alisa , Lee Jeehyun
Published: July 2024

Emotion research has been gaining interest in the food industry to help add another aspect to the sensory evaluation of a product. The EsSense Profile® is a method that has been developed to measure emotions associated with general food and drink consumption in a product development context. Coffee has become a very popular drink and an important part of most people's routine. It is consumed for many different reason depending on the individual and certain lifestyle factors, whether for a relaxer, mental clarifier, or stimulator. Thus, the beverage can provide a desirable emotional experience. The Coffee Drinking Experience (CDE) is a product specific emotion scale developed for coffee consumption. Since the method has never been evaluated, the objectives of the study were to test CDE using the EsSense Profile® method as a comparison using coffee drinkers in Philadelphia. Time of the day and gender effects were also looked at as possible influences. Three hundred and thirty two coffee consumers from six coffee shops in the Philadelphia area participated in the natural environment study. Questionnaires were placed at the coffee shop where consumers voluntarily participated in the study. The questionnaire instructed participants to rate their emotions on a 5-point intensity scale before and after consuming their coffee beverage. A free coffee drink was an incentive for returning a completed ballot. The response rate from the six coffee shops was 57%. The t-tests showed that more terms from the EsSense Profile® method (82.1%) were significant compared to the Coffee Drinking Experience (77.3%). Both methods showed that participants were in a positive mood before coffee consumption and rated the negative terms the lowest in emotional intensity (disgusted, guilty, aggressive, worried, bored). Both male and female participants felt both positive and negative emotions with neither gender showing more pronounced emotions. For time of day effects, the afternoon group showed less emotion changes than the morning and afternoon group and the CDE method was also able to capture the influence of coffee by showing a more active and task oriented mental state in the morning and afternoon group. While the EsSense Profile® had more significant terms and shows that it is a good baseline for an initial emotion study for a new product, it does not capture the influences of coffee. For example, the results from the CDE method showed significant differences in the emotion terms related to the focus mental state (motivated, productive, clear minded). Further research is needed, but overall our results show that there may be a need for focus on product specific emotion scales.
Control of the optical properties of a medium by atomic coherence and quantum interference effects
Authors:   , Martinez Maria Aparecida Goncalves
Published: July 2024

The control of the optical properties of a medium by atomic coherence and quantum interference effects is an important area of research, not only for its fundamental aspects in the understanding of radiation and matter interaction, but also for its potential applications in the design of optical devices. Atomic coherence can emerge in a medium through the coupling of a strong coherent field to an atomic transition. This coupling affects the optical properties of the medium in a very interesting ways. For example, it may yield light amplification without population inversion. Also, it can modify the traditional dispersion of an optical medium in such a way that maximum variations of the refractive index occur around a spectral region of vanishing absorption. In the first part of this work we investigate some fundamental aspects of this coherent dynamics. We investigate how this non-inversion gain is affected by the presence of atomic motion. The coherent interaction between atom and radiation can lead to the interference between optical paths of decay. We report on an atomic setting where the interference structures depend upon the phase of the coherent field, an new effect which is absent in other resonance fluorescent phenomena. As a potential application, we investigate a novel approach for the modulation of optical signal. This approach consists of injecting atomic coherence in the medium in order to tailor its optical properties so it is a more suitable medium for modulation.
Quantification of Cell Death due to Ultrasound Therapy with Contrast Agents
Authors:   , Dierkes James M. , Wrenn Steven Parker
Published: July 2024

In this work, the authors conduct in vitro studies of the effects of ultrasound (US) therapy with contrast agents. Both microbubbles with a phospholipid shell alone and microbubbles encapsulated with a polymer capsule were utilized as contrast agents. With increased concentrations of microbubbles, more cell death occurred due to the increased number of acoustic shock waves if the pressure is above the inertial cavitation threshold. When one micron microbubbles are enclosed in a 3-5 micron polymer capsule, no cell death occurredt any pressure or concentration. This increased cell viability is the result of an increase in the inertial cavitation threshold due to the coencapsulation of the microbubbles. The coencapsulated microbubbles proved safer than commercial contrast agents for imaging without sacrificing the quality of the image.
Teacher attributions of children's problem behavior
Authors:   , Coleman Margo Stephanie , Nezu Christine M.
Published: July 2024

The purpose of this study was to investigate whether special education professionals' attributions could be altered after being taught a component of a clinical decision making model (Nezu & Nezu, 1989). Specifically, this study investigated the effect a modified clinical decision making model had on special education professionals' attributions regarding the causes and costs of socially defiant behavior in children. In addition, the generalizability of these changes was assessed using two additional posttest vignettes. Subjects for this study were 61 special education professionals from a private school facility for children and adolescents with developmental disabilities. They were randomly assigned to one of two groups: (1) Control (CONTROL) and (2) Clinical Decision Making Model (CDM). Pretest data were collected using the Teacher Tolerance Scale (Cunningham & Sugawara, 1988; 1989) and measures of causal attributions and costs (class, indirect, student and teacher) of the problem behavior presented in the pretest vignette. During the intervention phase, the Control group watched a videotape on functional curriculum while the CDM group watched a videotape on the problem orientation component of the clinical decision making model (Nezu & Nezu, 1989). Posttest data were collected using measures of causal attributions and costs (class, indirect, student and teacher) of the problem behavior presented in the pretest vignette and the two additional posttest vignettes. Two Repeated Measures MANOVAs were calculated to determine whether being taught the CDM model changed special education professionals' attributions regarding the causes of children's problem behavior. There were no significant changes in special education professionals' attributions regarding the causes of children's socially defiant behavior. In addition, there was no generalizability of changes in causal attribution across additional posttest vignettes. Two Repeated Measures MANCOVAs were calculated to assess whether being taught the CDM model, changed special education professionals' attributions regarding the costs of children's problem behavior. There was no change in the CDM groups' perceptions regarding the costs of socially defiant behavior. However, both groups perceived one vignette as having lower class and teacher costs. These findings suggest that, among other factors, the special education professionals were already sensitized to the concepts underlying behavioral analysis techniques. Future research should evaluate the effectiveness of the CDM model with teachers not previously exposed to behavioral analysis techniques.
Auditor-client negotiations of financial statement adjustments
Authors:   , Sanchez Maria H. , Jaenicke Henry R.
Published: July 2024

An independent auditor is often unwilling to issue an unqualified opinion on the financial statements as prepared by client management. When this is the case, the auditor will propose adjusting journal entries. If the client is averse to posting any or all of the adjusting journal entries, the auditor and client will negotiate over which entries get posted and which get waived. This study examines a particular strategy used by auditors involving cognitive heuristics identified in the behavioral decision theory literature to aid them in their negotiations with clients over financial statement adjustments. I examine whether the strategy of proposing more audit adjustments than needed for an unqualified opinion and then agreeing to waive some of the immaterial adjustments (the "Concession Strategy") is an effective strategy. An effective strategy is one whereby (1) The likelihood of the client posting the material adjustments is greater than when not using the Concession Strategy, (2) Higher client satisfaction results than when not using the Concession Strategy, and (3) The likelihood of the client using the audit firm again the following year is greater than when not using the Concession Strategy. The results of the study indicate that the Concession Strategy increases the willingness of the client to post material audit adjustments, increases client satisfaction, and increases the likelihood of the client using the auditing firm again the subsequent year. A more complete understanding of the auditor-client negotiation process has implications for both professionals and academics.
Prediction of protein structures and interaction sites
Authors:   , Shan Yibing , Zhou Huan Xiang
Published: July 2024

This thesis project was focused on homology-based prediction of protein structures from amino acid sequences, and prediction of potential protein-protein interface residues. In the project, a threading method based on dynamical programming was developed and tested, which is integrated in COBLATH, a program our group developed for fold recognition and query-template alignment. Results of COBLATH show that the combination of two existing methods, PSI-BLAST and threading, leads to significant enhancement in the success rate of fold recognition and alignment accuracy. The thesis project was involved in structural annotation on Mycoplasma genitaanium and Saccharomyces cerevisiae genomes by COBLATH. The results of the annotations are presented. Our group selected a nonhomologous set of 744 complex-forming protein pairs from PDB and identified the interface residues of these proteins. Based on this protein set split for training and testing, a neural-network-based method (PPISP) for prediction of protein-protein interface residues in a given structure was developed in the thesis project. This method takes a surface residue's solvent accessibility and the position specific sequence profile of itself and its 19 nearest surface neighbors as input for its prediction. A prediction accuracy of 70% is obtained when the method is tested on 129 pairs of nonhomologous complex-forming proteins. The development of COBLATH and PPISP opens the possibility that protein-protein interaction sites may be predicted on a genome-wide scale. To that end, we have built structural models for yeast protein-protein complexes based on the predicted structures of the individual proteins by COBLATH and the experimental complex structures from other species. Structures of these complexes, FTase, GGTase, and Ras-Gap complexes in particular, are analyzed to gain understanding of their biological specificities. To make progress toward establishing the physical basis of protein stability, we searched for parallels between residue-residue potential of mean force (PMF) in proteins and in liquids. We found some remarkable similarities.
Earthquake resistance of buried pipelines
Authors:   , Larbi Ahcene
Published: July 2024

A complete dynamic analysis is performed for the investigation of the behaviour of buried pipelines in a seismic environment. Axial and transverse displacements and axial and bending strains are evaluated. The effects of seismic ground motion parameters and structural and soil characteristics on the response of these extended structures are determined. These include: seismic ground motion frequency and velocity, which, combined, produce the ground motion wavelength; the material properties and geometrical configuration of the structure; the soil-structure interaction; and the soil classification. Sensitivity analyses with respect to these parameters are performed. Two types of resonance are identified in this space-time problem: frequency and spatial resonance. It is shown that spatial resonance (proximity of the ground motion wavelength with a mode shape of the structure) contributes more to the response than frequency resonance (proximity of ground frequency with a structural natural frequency). The significance of axial vs. bending strains is examined; the ground motion characteristics that yield dominant axial or bending strains are determined. Cases when slippage between the pipeline and the surrounding soil is likely to occur are identified. Based on the detailed analysis of the seismic response of pipelines, pipeline response spectra are introduced. The input motion at the supports of these long structures is described by the commonly used seismic ground motion spectra, which are available for the analysis of conventional "point" structures (buildings), and the estimated apparent propagation velocity of the motions of the ground surface; the pipeline response is approximated by simple expressions obtained through curve fitting of the actual analytical results. These response spectra can be readily used in the evaluation of the seismic resistant design of buried pipelines.
Platelet activating factor receptor(s) mediates cell death induced by "Ischemia-reperfusion" in an hippocampal cell line
Authors:   , Shi Leng-Chu , Friedman Eitan
Published: July 2024

Mild ischemic/hypoxic insult produces delayed neuronal damage in many brain areas which may undergo apoptosis. A phospholipid, PAF, is thought to mediate neuronal damage produced by ischemia/reperfusion, PAF production and metabolism are increased by ischemic/hypoxic lesion, and PAF antagonists are shown to protect neuronal damage. However, the molecular mechanism of PAF action on the neurons subjected to hypoxic/ischemic insult is unclear because of the heterogeneity of brain. Therefore, the possible role of PAF receptor(s) in the ischemia/reperfusion was examined in order to further our knowledge concerning the underlying mechanisms of neuronal damage due to ischemic/hypoxic insult. Specifically, experiments were designed to investigate the effects of hypoxia/hypoglycemia in a hippocampus-derived cell line, HN33.11 cells, a cell line which exhibits PAF-stimulated PI metabolism via Gq and Gi proteins on (1) the role of PAF receptors in cell death due to hypoxia/ hypoglycemia and (2) functions of PAF receptor-coupled G proteins in mediating cellular damage during hypoxic insult. A delayed cell death with apoptotic features was observed when cells were treated with hypoxia/hypoglycemia condition (ischemia) followed by incubation in normal control medium (reperfusion). PAF produced in the early reperfusion elicited cellular death which was inhibited by PAF receptor antagonists. The PAF receptor-elicited intracellular Ca²⁺ increase may mediate the PAF action during reperfusion. Treatment with pertussis toxin increased cellular damage induced by ischemia/reperfusion. PTX treatment also potentiated cell death induced by the PAF analogue. On the other hand, G[alpha]q antisense treatment protected cells from ischemia/reperfusion induced cell death by decreasing G[alpha]q protein levels. Moreover, this treatment also attenuated MC-PAF-induced cell death during ischemia/reperfusion. In conclusion, hypoxia/hypoglycemia in HN33.11 cells induces a delayed cell death via apoptosis; this is mediated by a delayed increase in PAF production and activation of PAF receptor. Gq and Gi proteins, which are functionally coupled to PAF receptor(s), play antagonistic roles in PAF receptor mediated ischemia/ reperfusion-induced cellular damage. The predominant coupling between PAF receptor and Gq may underlie the injury induced by ischemia/reperfusion in HN33.11 cells.
Adult attachment and its association with substance dependence treatment outcome
Authors:   , Frank Jeremy
Published: July 2024

Attachment is a process in which affective bonds are initiated and maintained between individuals. Substance dependence is a disorder affecting millions of individuals. To date, little research has been conducted into the relationship between adult attachment and the substance use disorders. The purpose of this investigation was to explore the association between adult attachment styles and the initiation, maintenance and recovery of substance dependence. Attachment styles of substance dependent patients were explored with particular attention toward their association with several indices of recovery outcome and recovery-related variables at nine months follow-up after completion of an approximately eight week intensive outpatient rehabilitation program. Of special interest, in terms of recovery-related variables, were behavioral levels of engagement in twelve-step programs such as Alcoholics Anonymous and Narcotics Anonymous. Several findings indicated an association between attachment, substance dependence and recovery outcome. Results from this investigation suggested that substance dependent patients tended to have more insecure styles of attachment and that avoidance may have been a prominent attachment style for patients presenting to substance abuse treatment centers. While adult attachment appeared to be associated with substance dependence the association between adult attachment and recovery from substance dependence was generally not substantiated. However, minor associations between attachment as measured by the Trichotomous Attachment Classification (TAC) and the Attachment Style Questionnaire (ASQ), and recovery outcome as measured by the Addiction Severity Index Composite Scores (ASI-CS) suggest further investigation is warranted. Important, albeit small, associations were found between adult attachment and treatment completion. While there was practically no association found between adult attachment and recovery as measured with the ASI-CS or the self-report of abstinence, there were some important associations found between attachment and other recovery-related variables although these results were mixed. While none of the recovery-related variables were associated with changes in ASI-CS scores, some interesting mixed associations were found among the recovery-related variables. One important finding concerned a significant association between obtaining a sponsor and the self-report of abstinence. There were some findings in this study that might suggest that an insecure style of attachment could be associated with some positive aspects of recovery outcome. The clinical implications, limits of this investigation, and directions for future research are addressed.
BffA
Authors:   , Marin Courtney A. , Ninio Shira
Published: July 2024

Legionella pneumophila is a Gram negative, facultative intracellular pathogen, and the causative agent of Legionnaires' disease, a severe pneumonia. Legionella is responsible for the greatest number of deaths from waterborne diseases per year in the United States, leading to an additional 18,000 hospitalizations annually. As an intracellular pathogen, L. pneumophila survives within a specialized vacuole known as the Legionella-containing vacuole (LCV) where it forms a replicative niche. Upon interaction with host cells, L. pneumophila utilizes a Type IV secretion system (T4SS) to inject over 300 secreted effectors into the host cell. Some of these effectors play crucial roles in stabilizing the LCV, recruiting endoplasmic reticulum (ER)-derived vesicles, and altering the trafficking of the LCV to avoid lysosomal death of Legionella. However, in the environment, L. pneumophila has multiple options for growth and survival including planktonic growth, intracellular replication within protozoa, and the formation of single-and multispecies biofilms. Biofilms are an important niche because they allow for enhanced survival by protecting the bacteria from antimicrobial agents and temperature fluctuations while increasing nutrient and oxygen exchange. In this work we studied two separate modes of replication for L. pneumophila, (a) biofilm formation and regulation, and (b) we developed a new method for identifying the mechanism of binding of secreted effector proteins to the LCV. We identified a putative phosphodiesterase, BffA, which appears to be involved in the regulation of biofilm formation, motility, and cellular replication of L. pneumophila. Strains deleted for bffA display hyper-biofilm growth, significantly reduced motility, and enhanced growth and replication. Additionally, we observed enhanced uptake of a [delta]-bffA strain into Acanthamoeba castellanii, which enabled this strain to outcompete wild type L. pneumophila in direct competition assays in A. castellanii. Taken together, our studies suggest a role for BffA in regulatory pathways controlling biofilm formation, motility, and replication.
Assessing executive functioning and prospective memory in children and adolescents in a disease and control population
Authors:   , Kennard Kerri J. P.
Published: July 2024

This study hypothesized that "prospective memory" was associated with "executive functioning" and distinct from retrospective memory. Prospective memory was examined with 2 behavioral tasks and with a 20-item Likert scale questionnaire designed to measure parent's view of their child's prospective memory abilities. This questionnaire was administered to 100 parents. Psychometric properties of the questionnaire showed it to be high in internal consistent (Cronbach Alpha =.94) and homogeneity (loading on one factor). Discriminant analysis measures found the prospective memory tasks to be distinct from retrospective memory tasks and loading on the same factor as the executive functioning tasks. However, there was a lack of correlation between the prospective memory tasks and the prospective memory questionnaire. The neuropsychological development of prospective memory and executive functioning, in disease and control samples of children ages 5 to 17 years (n = 79) was examined. Children were found not to be proficient in executive functioning skills until the age of 10. Pearson r correlations and analysis of variance found only a small relationship between age and prospective memory task, which could not be verified with a Newman-Keuls post hoc test. Age was found to significant effect the WCST (number of categories), and Verbal Fluency performance. Newman-Keuls post hoc tests verified there to be a significant different between the youngest age group (72 to 119 months) and the two older age groups (120-167 months and 168-204 months, respectively). This study examined the effects of a disease on executive functioning and prospective memory. Lyme disease was chosen as the disease model given that previous studies with adults, have found memory-like deficits which can be conceptualized as prospective memory deficits (Logigan, Kaplan and Steere, 1990). 42 Lyme disease children were compared to 14 children diagnosed with Post-Infectious Reactive Arthropathy (a disease that mimics many of the same physical symptoms as Lyme disease) and 23 control siblings. Results indicate no difference in childrens' executive or memory functioning between diagnostic groups. Thus, this study confirmed the hypothesis there is a relationship between prospective memory and executive functioning, while at the same time verifying how these skills are discriminant from retrospective memory.
Manufacturing Improvements to the Centrifugal Pump Leading to an Increase in the Efficacy and Safety of the Pump During Clinical Use
Authors:   , Brooks Brian T. , Allen Fred D.
Published: July 2024

With the development and refinement of the heart-lung machine, the repair of complicated congenital and acquired heart defects and disorders are very common procedures. During cardio-pulmonary bypass (CPB) surgery, a heart-lung machine is'used in conjunction with an extracorporeal blood flow circuit that maintains blood circulation to the patient's organs and tissues while the surgeon works on the heart in a safe and bloodless surgical field. One of the major components of this extracorporeal circuit is the arterial pump which essentially serves as the patient's heart in the heart-lung machine. This study addresses modifications made to improve the performance of such an arterial pump, the Centrifugal Pump produced by (Manufacturer Name Redacted). Since the first clinical use of CPB more than 50 years ago, numerous positive changes in the engineering and manufacturing of medical devices has made blood perfusion safer. Nevertheless, accidents still happen and there are a number of associated problems with the devices used during the surgery. One of the leading causes of patient mortality during CPB is device malfunction resulting in component change out. Components of the extracorporeal circuit are changed for a variety of reasons. Blood leakage is one of the primary causes. Particularly in the centrifugal arterial pump, blood leakage through the sealing surface created by the injection molded halar seal rotor and into the back chamber of the pump is significant reason to require component change out. In the medical device industry device malfunctions in the field are reported as complaints, and these complaints are then trended based upon complaints per million parts produced (CPM). Production and complaint data for the incidence of blood leaks in the (manufacturer ngme redacted) Centrifugal Pump were determined to be 41.09 CPM for FY2008 and 48.36 CPM for FY2009. It was hypothesized that improvements to the production process would increase the quality of the centrifugal pump, thereby resulting in a reduction in the incidence of failure (CPM) due to pump leaking in the field. These improvements included: (1) implementation of an automated seal rotor vision system to replace a subjective and inaccurate human inspection, (2) modifications to the application of a medical fluid aimed at reducing uneven wear of the seal rotor during clinical use, and (3) enhancements of the sensitivity of the centrifugal pump final leak tester to more accurately detect defects prior to device release to the field. Overall, it was the objective of this study to develop effective changes in these production procedures that would greatly reduce the likelihood of pump leaks in the field resulting in lower CPM. Since the implementation of these production improvements, over 72,000 Centrifugal Pumps have been produced, and from these pumps, not a single incidence of blood leaking has been reported which equates to a CPM of zero.
The rolling and strip drawing of Clad sheets strips
Authors:   , Nowicke Frank Lloyd , Rogers Harry C , Zavaliangos Antonios
Published: July 2024

In this work we examine in detail the instability present in the rolling of clad sheets with supplemental results from the clad sheet drawing and tension testing presented as well. Our work clearly demonstrates two important trends that have not been reported before. Namely that the plastic instability present in the rolling of the clads made with two materials with different flow stress is significantly delayed with increasing fraction of the stronger component in the clad and by decreasing roll radius. It is shown that the redundant work is partially responsible for these trends although a modified instability analysis still under predicts the observed results.
Experimental study and numerical simulation on synthesis, properties, and applications of oxide-coated ceramic particles
Authors:   , Yang Chia-Yi , Shih Wei-Heng , Shih Wan Y
Published: July 2024

This thesis combines experimental studies and numerical simulations to gain qualitative and/or quantitative understanding on the synthesis and properties of oxide-coated ceramic particles. Experimentally, boehmite had been successfully coated on the surface of SiC by a sol-gel coating approach. We found that as the amount of added boehmite precursor increases, the thickness of coating layer increases, and reaches a saturated value. Also, the maximum sedimentation density of boehmite-coated SiC suspensions, [special characters omitted] increased with increasing coating thickness from under 25vol% with 10wt% boehmite to above 65vol% with 10wt% boehmite. The coated-particle suspensions exhibited viscoelastic behaviors and the maximum storage modulus, [special characters omitted] decreased with an increasing coating thickness, t, as [special characters omitted] The boehmite sol-gel coating technique was applied to various ceramic particles, and the results showed that the presence of carbon on the surface of core particles is important for the boehmite coating. There were two possible morphologies, continuous shell-like coating and patchy island-like coating, depending on the Hamaker constant of core particles. Monte Carlo simulations was used to investigate the controlling factors of coating morphology. Our model was based on a reversible cluster-cluster aggregation model. It allows particles to aggregate and unbind, and performs precipitation and coating at the same time. The model includes two levels of interactions: one is the attraction energy, -E, between monomers that aggregate to form particles; the other is the interparticle interaction energy that affects the aggregation of particles. We found that a system with a weaker (stronger) monomer-monomer attraction energy has a higher (lower) solubility. The monomer-wall attraction energy, - Ew was used to determine the stickiness of the walls, which represented the surface of core particles. The result showed that the system with a higher solubility grew a thicker coating layer with a faster growth rate. Also, the morphology of coating layer was controlled by a combination effect of E and Ew. When a system has a E/Ew ratio larger than unity, it tends to form patchy and island-like coating; on the other hand, a system with E/Ew ratio smaller than unity favors the formation of continuous shell-like coating layer. The sol-gel coating technique was employed to coat boehmite onto zirconia. It showed an improvement in the thermal stability, which is important in catalytic applications.
A study of two modified hydride delivery systems
Authors:   , Learn Keith S.
Published: July 2024

Part I. The reductive displacements by hydride transfer reagents of a number of allylic leaving groups (e.g., esters, ethers, tosylates, halides, alcohols, silyl ethers, phenyl sulfones, phenyl sulfides, phenyl selenides) to form alkenes via catalytic activation by tetrakis(triphenylphosphine)palladium (O) was investigated. Substantial control in determining the position of the double bond in product alkenes was found to be possible through proper selection of the hydride reagent. From primary allylic substrates, ammonium formate and formic acid hydride transfer agents afforded predominantly 1-alkenes. In contrast, LiEt(,3)BH and i-Bu(,2)AlH gave 2-alkenes almost exclusively and with a high degree of maintenance in the stereo-chemical integrity of the double bond. Weaker hydride sources (e.g., NaBH(,3)CN, NaBH(,4)) exhibited inferior regio- and stereoselectivity. A mechanistic rationale for the differing selectivities is given. These results establish a useful synthetic method in terms of the conversion of substrates containing allylic functionalities into alkenes. They also present a useful means of protecting -OH, -SO(,2)H, -SH, and -SeH functionalities via formation of allyl derivatives and subsequent deprotection with Pd(O)/hydride reduction. In the absence of a hydride reagent, in dimethylsulfoxide solvent, allylic substrates undergo a palladium catalyzed-elimination reaction affording conjugated dienes in good yield. Part II. The reducing ability of sodium dimethylaminotrihydroborate (1-) (NaDMAB) towards a number of common organic functional groups was investigated. Aldehydes, ketones, and esters were reduced to the corresponding alcohols in high yield. Primary amides were reduced to the corresponding amines. Tertiary amides were reduced to alcohols (e.g., N,N-dimethylamides) or amines (e.g., N,N-diisopropylamides) depending on the bulk of the alkyl substituents on nitrogen. Secondary amides were not reduced by NaDMAB. As a result, primary and tertiary amides can be selectively reduced in the presence of secondary amides. A mechanistic rationale is given. Whereas aryl halides were reduced to arenes, alkyl halides and an epoxide were attacked by the dimethylamine portion of NaDMAB affording the corresponding amines. Nitriles were also reduced to amines. The reductions of a nitro compound and a sulfoxide afforded pre-dominantly axo compounds and cleavage products, respectively.
An evaluation of the psychometric properties of the ADHD Rating Scale-IV
Authors:   , Goldstein Suzanne G.
Published: July 2024

The present study was designed to evaluate the extent to which the ADHD Rating Scale-IV: School Version is appropriate for use with children from varying cultural and socioeconomic backgrounds. This study improved upon previous studies by measuring families' socioeconomic status (SES) as well as child and teacher ethnicity. Four inner city schools from the Philadelphia Public School District participated in this study. Fifty-seven teachers rated a total of 343 children on the ADHD Rating Scale-IV: School Version. The students were all either African American or Caucasian. Consistent with the findings of previous studies, the present study demonstrates that ethnicity and gender are significantly related to teacher ratings (Reid et al., 1998; Jarvinen & Sprague, 1996). African American males received the highest ratings, where higher ratings indicate more behavior problems. Ethnicity was found to be a significant predictor of teacher ratings even when accounting for the effects of SES. The data acquired for the present sample were directly compared to similar children from the normative sample (DuPaul, Power, Anastopoulos, & Reid, 1998). Contrary to what was hypothesized, children in the present sample were rated as having fewer behavior problems than children in the normative sample. This finding may be due to differences in sampling procedures. Although data from all samples indicated that the two factors of the scale, Inattention and Hyperactivity/Impulsivity, were highly correlated, there are theoretical and clinical benefits of maintaining the two subscales. The factor structure of the scale was found to be similar across both samples and between the two ethnicities in the present sample. Therefore, the ongoing use of this measure with urban, minority populations is supported.
Processing, microstructure and property relationships in a powder metallurgy high speed steel
Authors:   , Fareed Ali S.
Published: July 2024

REX 25('TM) high speed steel, processed from rapidly solidified gas atomized powder, has been studied in detail with respect to microstructure, strength, toughness, grindability, wear resistance and hardness at elevated temperatures. Powders were nitrogen gas atomized, screened to specific size fractions and consolidated to full density by hot isostatic pressing. The HIPed material was either heat-treated or hot-worked by forging prior to heat-treatment. Two HIPing temperatures, two austenitizing temperatures and three tempering temperatures were evaluated. X-ray diffraction, optical and scanning electron microscopy were utilized to characterize the microstructure in the atomized and consolidated conditions. Atomized powders exhibit segregated structures, with MC and M(,2)C carbides present in the form of an interconnected network. The proportion of MC carbides increases and the scale of microstructure is refined, with decreasing powder particle size. Traces of M(,6)C carbides are observed in the coarse size fractions. The matrix phase in the fine powders is (delta)-ferrite. Slower cooling promotes the formation of martensite. After HIPing, the carbide networks observed in the atomized powders are replaced by individual MC, M(,6)C and M(,23)C(,6) carbides in a ferritic matrix. Carbide size distributions are independent of prior particle size fraction, but are displaced towards coarser carbides with increasing HIPing temperature. Carbide volume fractions are independent of size fraction and HIPing temperature. Prior austenite grain size is a function of the HIPing and austenitizing temperature, and of the intermediate forging step. In the tempered condition, carbide volume fractions are independent, whereas carbide size distributions are a function of the HIPing temperature and the introduction of an intermediate forging operation. Strength and toughness are enhanced by hot forging. Austenitizing at a lower temperature results in improved strength and decreased hot hardness. Strength, toughness, hot hardness and wear resistance are similar to those in the corresponding commercial P/M high speed steel.
Characterization and analysis of diesel exhaust odor
Authors:   , Shala Francis John
Published: July 2024

An instrumental method known as the Diesel Odor Analysis System or DOAS, has been developed at A. D. Little, Inc. for measuring diesel exhaust odor. This method is based on the correlation found between the exhaust odor intensity, as measured by an odor panel, and the UV response of the oxygenated fraction of the exhaust. It was of interest to determine which compound or compounds in the oxygenated fraction of the exhaust were primarily responsible for the odor correlation as developed at A. D. Little, Inc. This was accomplished by observing how the measurement of the exhaust odor intensity and number of chemical constituents of the oxygenate fraction were changing with respect to the odor values as measured by the DOAS. Exhaust from a single cylinder IDI-CFR diesel engine operated over a wide range of test conditions was sampled and analyzed by the current DOAS methodology. The oxygenated fractions were obtained by separation of the exhaust samples on a silica Sep-Pak cartridge and analyzed by capillary gas chromatography. Computerized GC profiles were produced from which character impact peaks were chosen for correlations with odor as measured by the DOAS method. Peaks were also found that correlated with engine air to fuel ratio. Benzaldehyde was found to give the best correlation (R = 0.98) with odor. A quantitative relationship between exhaust odor as measured by the total intensity of aroma (TIA) and the benzaldehyde concentration (B) in ppm in the exhaust is given by: TIA = 1.11 log(,10) (B) + 4.10 This correlation was supported by results obtained from two other diesel engine exhaust sources. A methyl benzaldehyde isomer also yielded a good correlation (R = 0.90) with odor. Air to fuel ratio correlations were determined for the tentatively identified compounds, cinnamaldehyde (R = 0.94) and a C2 - benzaldehyde isomer (R = 0.94). Sampling effects were studied by using chemical and C-14 labeled tracer compounds and GC profiling. Results showed that each tracer compound had its own particular breakthrough and recovery pattern which could be dependent on the sampling rate and sample volume collected. GC profiles indicated that the majority of organic compounds measured by the DOAs are low molecular weight oxygenates.