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Mechanisms Affecting Bench Press Throw Performance while Using a Counter-Balanced Smith Machine

Mechanisms Affecting Bench Press Throw Performance while Using a Counter-Balanced Smith Machine

Date: May 2011
Creator: Buddhadev, Harsh
Description: The use of a counter-balance weight system of a Smith machine affects measures of bench press throw performance. Twenty-four men performed bench press throws at 30% of their one-repetition maximum under four different conditions: 1) counter-balance and rebound movement (RC), 2) no counter-balance and rebound movement (RNC), 3) counter-balance and concentric only movement (CC), and 4) no counter-balance and concentric only movement (CNC). Peak power, force, and concentric and eccentric velocities were measured using a linear accelerometer; and peak ground reaction force (GRF) was measured using a forceplate. Peak measures for concentric and eccentric velocities showed that NCB> CB and RBT > CBT. Peak GRF measures showed CB > NCB and RBT > CBT. The lower performance measures for CB were likely due to an increase in the net external load when the barbell accelerates faster than the gravitational constant causing the counter-balance weight becomes ineffective.
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Mechanisms of Methoxide Ion Substitution and Acid- Catalyzed Z/E Isomerization of N-Methoxyimines

Mechanisms of Methoxide Ion Substitution and Acid- Catalyzed Z/E Isomerization of N-Methoxyimines

Access: Use of this item is restricted to the UNT Community.
Date: December 2001
Creator: Dolliver, Debra D.
Description: The second order rate constants for nucleophilic substitution by methoxide of (Z)- and (E)-O-methylbenzohydroximoyl fluorides [C6H4C(F)=NOCH3] with various substituents on the phenyl ring [p-OCH3 (1h, 2h), p-CH3 (1g, 2g), p-Cl (1f, 2f), p-H (1e, 2e), (3,5)-bis-CF3 (1i, 2i)] in 90:10 DMSO:MeOH have been measured. A Hammett plot of these rate constants vs σ values gave positive ρ values of 2.95 (Z isomer) and 3.29 (E isomer). Comparison of these rates with methoxide substitution rates for Omethylbenzohydroximoyl bromide [C6H4C(Br)=NOCH3] and Omethylbenzohydroximoyl chloride [C6H4C(Cl)=NOCH3] reveal an element effect for the Z isomers of Br:Cl:F(1e) = 2.21:1.00:79.7 and for the E isomers of Cl:F(2e) = 1.00:18.3. With the p-OCH3-imidoyl halides the following element effects are found: Br:Cl:F(1h) = 2.78:1.00:73.1 for the Z isomer and Br:Cl:F(2h) = 1.97:1.00:12.1 for the E isomer. Measurement of activation parameters revealed ∆S≠ = -17 eu for 1e and ∆S≠ = -9.9 eu for 2e. Ab initio calculations (HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6- 31+G*//HF/6-31+G*, HF-SCIPCM/6-31+G*//HF/6-31+G*) were performed to define the reaction surface. These calculations demonstrate a relatively large barrier for nucleophilic attack in relation to halogen loss and support the experimental findings that this reaction proceeds by an addition-elimination mechanism (AN# + DN). The imidoyl fluorides have been used to synthesize ...
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Mechanisms of Ordered Gamma Prime Precipitation in Nickel Base Superalloys

Mechanisms of Ordered Gamma Prime Precipitation in Nickel Base Superalloys

Date: May 2011
Creator: Singh, Antariksh Rao Pratap
Description: Commercial superalloys like Rene88DT are used in high temperature applications like turbine disk in aircraft jet engines due to their excellent high temperature properties, including strength, ductility, improved fracture toughness, fatigue resistance, enhanced creep and oxidation resistance. Typically this alloy's microstructure has L12-ordered precipitates dispersed in disordered face-centered cubic γ matrix. A typical industrially relevant heat-treatment often leads to the formation of multiple size ranges of γ¢ precipitates presumably arising from multiple nucleation bursts during the continuous cooling process. The morphology and distribution of these γ′ precipitates inside γ matrix influences the mechanical properties of these materials. Therefore, the study of thermodynamic and kinetic factors influencing the evolution of these precipitates and subsequent effects is both relevant for commercial applications as well as for a fundamental understanding of the underlying phase transformations. The present research is primarily focused on understanding the mechanism of formation of different generations of γ′ precipitates during continuous cooling by coupling scanning electron microscopy (SEM), energy filtered TEM and atom probe tomography (APT). In addition, the phase transformations leading to nucleation of γ′ phase has been a topic of controversy for decades. The present work, for the first time, gives a novel insight into the mechanism ...
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Mechanisms of rapid receptive field reorganization in rat spinal cord

Mechanisms of rapid receptive field reorganization in rat spinal cord

Date: August 2002
Creator: Vu, Hung
Description: Rapid receptive field (RF) reorganization of somatosensory neurons in the rat dorsal horn was examined using extracellular single unit recording. Subcutaneous injection of lidocaine into RFs of dorsal horn neurons results in expansion of their RFs within minutes. The expanded RFs appear adjacent to or/and proximal to original RFs. Out of 63 neurons tested, 36 (58%) show RF reorganization. The data suggest that dorsal horn of spinal cord is one of the initial sites for RF reorganization. The neural mechanisms of this effect are not well understood. We propose that changes in biophysical properties (membrane conductance, length constant) of the neurons resulting from lidocaine injection contribute to RF reorganization. Iontophoretic application of glutamate onto dorsal horn neurons that show lidocaine induced RF's expansion were used to test the model. Application of glutamate produced reduction of reorganized RFs in 9 of 20 (45%) tested cells. Application of NBQX produced no effect on either original or expanded RFs indicate that RF shrinkage effects of glutamate involve NMDA receptors. The results are consistent with the prediction of the proposed model. Subcutaneous injection of capsaicin into tactile RFs of low threshold mechanoreceptive dorsal horn neurons produced no effect on the RF sizes that are ...
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Mechanization of Aircraft Performance

Mechanization of Aircraft Performance

Date: 1956
Creator: Cotten, Frances Patterson
Description: The purpose of this paper is to describe the mechanization of the basic equations of motion for the performance and maneuver characteristics of an airplane with some simplifications which render solutions more practicable. The results of a study made to program these equations for calculation by the IBM MODEL 650 digital computer are presented as well as the steps to be taken in using this method of calculation.
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Media and Corporate Social Responsibility: How Leading Business Magazines Frame a Controversial Concept

Media and Corporate Social Responsibility: How Leading Business Magazines Frame a Controversial Concept

Date: August 2013
Creator: Riddell, Brad
Description: Corporate social responsibility (CSR) is an emerging concept that continues to play a controversial role in the business world. Different CSR theories and ethical foundations inform different approaches to embedding socially responsible behavior into today's business functions. As technology, globalization, and economic challenges change the corporate world, the meaning and application of CSR also changes. While no empirical evidence of CSR's impact on performance exists, many corporations operate under the assumption that CSR holds significant value. This study examines the framing of CSR in stories published by leading business magazines between 2008 and 2012. By examining the presentation of CSR concepts, the resulting analysis can provide important conclusions for corporations, public relations practitioners, mass media, and consumers. This study resulted in a hierarchical pyramid of frames that organizes the framing of CSR in business magazines into three layers: category, motivation, and classification as either responsible behavior or irresponsible behavior. These results lead to recommendations for future CSR research, including the need for quantitative evidence of a connection or disconnection between CSR and profitability.
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Media effects on the body shape ideal and bulimic symptomatology in males

Media effects on the body shape ideal and bulimic symptomatology in males

Date: December 1999
Creator: Barta, Jonna Lee
Description: This study investigates the impact of sociocultural mediators in relation to eating disorders among male undergraduates. Literature on eating disorders has demonstrated that a thin body shape ideal depicted in the media directly contributes to eating pathology among females, but little research has investigated the direct effects of ideal body shape images among men. The focus of the present investigation was to assess the direct effects of exposure to the ideal male body shape on men’s affect, self esteem, body satisfaction, and endorsement of U. S. societal ideals of attractiveness. In addition, the relation of these variables to bulimic symptomatology was examined. Modeling a study conducted on women (Stice & Shaw, 1994), male undergraduates between the ages of 18 to 25 participated in premeasure (N = 169) and post measure (N = 95) conditions. Participants in the post measure were randomly exposed to pictures from magazines containing either male models depicting the ideal body shape, an average body or pictures of clothing without models. Results from repeated mulitvariate analysis indicated that exposure to the ideal body shape condition did not demonstrate significant negative changes in men’s affect, self esteem, body satisfaction or endorsement of U. S. societal ideals of attractiveness. ...
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Media Influence on Executive Police Decision-Making: A Case Study of Police and Media Interaction During the Oklahoma City Bombing Investigation and Trials

Media Influence on Executive Police Decision-Making: A Case Study of Police and Media Interaction During the Oklahoma City Bombing Investigation and Trials

Date: May 2001
Creator: Bellew, Steven S.
Description: Because media influence public opinion, it is often surmised that media also influence the decisions of police executives. This exploratory case study examined the relationship between police and media during the Oklahoma City bombing investigation and subsequent trials of Timothy McVeigh and Terry Nichols. Findings indicate that media influence police executive decisions when police and media interact closely. It was found that during the Oklahoma City bombing investigation and trials, police on the outer perimeter were influenced most and police conducting the investigation or who were tasked to court room security were influenced the least. It was concluded, based on the consensus of respondents interviewed, that media do influence police executive decisions.
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Medial Medulla Networks in Culture: a Multichannel Electrophysiologic and Pharmacological Study

Medial Medulla Networks in Culture: a Multichannel Electrophysiologic and Pharmacological Study

Date: August 1998
Creator: Keefer, Edward W. (Edward Wesley)
Description: Spontaneously active primary cultures obtained from dissociated embryonic medial medulla tissue were grown on microelectrode arrays for investigating burst patterns and pharmacological responses of respiratory-related neurons. Multichannel burst rates and spike production were used as primary variables for analysis. Pacemaker-like neurons were identified by continued spiking under low Ca++/high Mg++conditions. The number of pacemakers increased with time under synaptic blocking medium. Sensitivity to CO2 levels was found in some neurons. Acetylcholine changed activity in a complex fashion. Curare, atropine and gallamine modified ACh effects. Eserine alone was ineffective, but potentiated ACh-induced responses. Norepinephrine caused channel-specific increases or decreases, whereas dopamine and serotonin had little effect at 30 μM. GABA and glycine stopped most spiking at 70 μM. Developmental changes in glycine sensitivity (increasing with age) were also observed. It is concluded that pacemaker and chemosensitive neurons develop in medial medulla cultures, and that these cultures are pharmacologically histiotypic.
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Mediated chameleons: An integration of nonconscious behavioral mimicry and the parallel process model of nonverbal communication.

Mediated chameleons: An integration of nonconscious behavioral mimicry and the parallel process model of nonverbal communication.

Date: May 2009
Creator: Beatty, Keturi D.
Description: This study explored the state of art education in Turkey as revealed by pre-service art education university instructors, and the potential of incorporating visual culture studies in pre-service art education in Turkey. The instructors' ideas about visual culture, and popular culture, the impact it might have, the content (objects), and the practices within the context of Turkey were examined. Visual culture was examined from an art education perspective that focuses on a pedagogical approach that emphasizes the perception and critique of popular culture and everyday cultural experiences, and the analysis of media including television programs, computer games, Internet sites, and advertisements. A phenomenological human science approach was employed in order to develop a description of the perception of visual culture in pre-service art education in Turkey as lived by the participants. In-person interviews were used to collect the data from a purposive sample of 8 faculty members who offered undergraduate and graduate art education pedagogy, art history, and studio courses within four-year public universities. This empirical approach sought to obtain comprehensive descriptions of an experience through semi-structural interviews. These interviews employed open-ended questions to gather information about the following: their educational and professional background; their definitions of art education and ...
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