In this research the benefits of applying oxy-combustion in a diesel engine to reduce NOx and particulate emissions were evaluated. The addition of oxygen to the intake in conjunction with exhaust gas recirculation (EGR) was shown to reduce NOx without an increase in particulate. Indicated specific NOx and particulate emissions for oxygen-enhanced EGR (O-EGR) and EGR without oxygen addition (normal or N-EGR) were compared at three engine loads. NOx emissions correlated with flame temperature for both N-EGR and O-EGR but were slightly lower at a given flame temperature for O-EGR. Flame temperature reduction for N-EGR was primarily through dilution of the available oxygen while for O-EGR both the increase of specific heat and dilution were important in reducing flame temperature. Oxygen addition allowed the use of high levels of EGR without reducing the oxygen concentration, thereby substituting CO2 and H2O for a substantial portion of the N2 as diluent. Increased dissociation due to higher levels of CO2 was believed to provide a minor enhancement to flame temperature reduction for O-EGR. An analysis of NOx formation based on the Zeldovich mechanism suggested that increased NOx reduction for O-EGR at equivalent flame temperatures is due to lower nitrogen concentrations. Indicated specific particulate increased with increasing EGR for N-EGR and correlated with flame temperature but remained constant for O-EGR and did not correlate with flame temperature. This indicated that O-EGR has a chemical effect on particulate formation and/or oxidation. The literature suggests CO2 suppresses soot formation by decreasing the radical H concentration which reduces the formation of soot precursors and soot growth.

Most domestication hypotheses propose that dogs have been selected for enhanced communication and interactions with humans, including learning socially from human demonstrators. However, to what extent these skills are newly derived and to what extent they originate from wolf–wolf interactions is unclear. In order to test for the possible origins of dog social cognition, we need to compare the interactions of wolves and dogs with humans and with conspecifics. Here, we tested identically raised and kept juvenile wolves and dogs in a social learning task with human and conspecific demonstrators. Using a local enhancement task, we found that both wolves and dogs benefitted from a demonstration independent of the demonstrator species in comparison to a control, no demonstration condition. Interestingly, if the demonstrator only pretended to hide food at the target location, wolves and dogs reacted differently: while dogs differentiated between this without-food and with-food demonstration independent of the demonstrator species, wolves only did so in case of human demonstrators. We attribute this finding to wolves being more attentive toward behavioral details of the conspecific models than the dogs: although the demonstrator dogs were trained to execute the demonstration, they disliked the food reward, which might have decreased the interest of the wolves in finding the food reward. Overall, these results suggest that dogs but also wolves can use information provided by both human and conspecific demonstrators in a local enhancement task. Therefore we suggest that a more fine-scale analysis of dog and wolf social learning is needed to determine the effects of domestication.

No description available.

The purpose of this study was to examine if differences exist in student learning outcomes between students who are instructed in a co-taught or non co-taught environment in secondary social studies classrooms implementing Content Enhancement Routines (CER). This study examined student and teacher data from seventeen matched pairs of co-taught and non co-taught middle and high school general education social studies teachers who participated in professional development in CER and professional development in co-teaching if applicable. Of the 34 participating teachers, 23 were visited by school district personnel to verify implementation of CER. Five co-teaching teams, each consisting of a general and special educator, completed a Coteaching Rating Scale (CtRS) (n=10) to analyze the level of co-teaching occurring in the classroom (beginning, compromising or collaborating stage). A systematic sample of students (n = 907) completed a CER Student Perception Survey to examine perceived differences of the use of CER in co-taught and non co-taught social studies classrooms. Student state assessment scores (n = 318) in co-taught and non co-taught classrooms were analyzed to distinguish differences in student learning gains. Specifically this study investigated if differences in student performance occur when a special educator is present in the classroom. Results indicate that although there was no statistically significant difference in student learning outcomes between the two settings, the impact of teacher preparation, professional development and the implementation of CER in the secondary social studies classroom may be determining factors in student success.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第23309号 / 情博第745号 / 新制||情||127(附属図書館) / 京都大学大学院情報学研究科知能情報学専攻 / (主査)准教授 吉井 和佳, 教授 河原 達也, 教授 西野 恒, 教授 田中 利幸 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Heat transfer is a critical part of engineering design, from the cooling of rocket engines to the thermal management of the increasingly dense packaging of electronic circuits. Even for the most fundamental modes of heat transfer, a topic of research is devoted to finding novel ways to improve it. In recent decades, investigators experimented with the idea of exposing systems to acoustic waves with the hope of enhancing thermal transfer at the surface of a body. Ultrasound has been applied with some success to systems undergoing nucleate boiling and in single-phase forced and free convection heat transfer in water. However, little research has been done into the use of sound waves to improve heat transfer in air. In this thesis the impact of acoustic waves on natural convection heat transfer from a horizontal cylinder in air is explored. An experimental apparatus was constructed to measure natural convection from a heated horizontal cylinder. Verification tests were conducted to confirm that the heat transfer could be described using traditional free convection heat transfer theory. The design and verification testing of the apparatus is presented in this work. Using the apparatus, experiments were conducted to identify if the addition of acoustic waves affected the heat transfer. For the first set of experiments, a 40 kHz standing wave was created along the length of the heated horizontal cylinder. While our expectation was that our results would mirror those found in the literature related to cooling enhancement using ultrasound in water (cited in the body of this thesis), they did not. When a 40 kHz signal was used to actuate the air surrounding the heated cylinder assembly, no measurable enhancement of heat transfer was detected. Experiments were also performed in the audible range using a loudspeaker at 200 Hz, 300 Hz, 400 Hz, 500 Hz, and 2,000 Hz. Interestingly, we found that a 200 Hz acoustic wave causes a significant, measurable impact on natural convection heat transfer in air from a horizontal cylinder. The steady-state surface temperature of the cylinder dropped by approximately 12℃ when a 200 Hz wave was applied to the system.

Over the past 2 decades, mindfulness-based interventions (MBI) in sport have grown from a niche application for performance excellence into a mainstream intervention for performance enhancement and well-being among athletes. The Mindfulness Meditation Training for Sport 2.0 intervention has contributed to the growth through its initial empirical support. Open trials and feasibility studies have shown encouraging results in several student-athlete populations. The purpose of this study was to evaluate the impact of a MBI in sport, MMTS 2.0, through the lens of a mixed methods quasi-experimental design examining specific psychometric correlates related with performance enhancement and well-being and a sport-specific outcome measure. The aim is to provide a more in-depth understanding of student-athletes’ experience completing Mindfulness Meditation for Sport 2.0 (MMTS) and demonstrate the opportunity for performance enhancement and holistic development through a MBI in sport. Participants were 60 student-athletes from two Division III collegiate men’s soccer teams who competed a sport-specific performance marker and seven psychometric measures at two time points (pre-intervention and post-intervention). One team (n=30) was selected as the experimental group who received the MMTS 2.0 intervention, and another team (n=30) was selected as the control group (no-treatment). In contrast to the hypothesis, the experimental group showed no significant difference in the performance marker and the seven psychometric measures when compared to the control group. Though, exploratory additions showed significant improvement for the MTMS 2.0 experimental group in self-compassion from pre-intervention to post-intervention, while no change was found with the control group. The study offers promising results that indicate the MMTS 2.0 increase student-athletes scores of self-compassion. While the statistical findings are limited, the qualitative responses from the participants (n=9) suggest that the MMTS 2.0 had a strong impact on their performance as a student and athlete. These findings provide insight into how the delivery of mindfulness and self-compassion skills in a time-limited environment help male athletes combat competition distress. Recommendations for new mindfulness and self-compassion scales to capture impact of a time-limited intervention are offered.

The discovery of carbon nanotubes in 1990s popularized a new area of research in materials science called Nanoscience. In the following decades, several carbon based nanoparticles were discovered or engineered and with the discovery of Graphene nanoplatelets (GNP) in 2010, carbon based nanoparticles were propelled as the most promising class of nanoparticles. High mechanical strength and stiffness, excellent electrical and thermal conductivity, and high strength to weight ratios are some of the unique abilities of CNTs and GNPs which allow their use in a wide array of applications from aerospace materials to electronic devices. In the current work presented herein, CNTs and GNPs are added to polymeric materials to create a nanocomposite material. The effects of this nanoparticle addition (a.k.a reinforcement) on the mechanical properties of the nanocomposite polymer materials are studied. Specifically, efforts are focused on studying fracture toughness, a material property that describes the material's ability to resist crack growth. Relative to the conventional metals used in structures, epoxy-based composites have poor fracture toughness. This has long been a weak link when using epoxy composites for structural applications and therefore several efforts are being made to improve their fracture toughness. In the first, second and third chapters, the enhancement of fracture toughness brought about by the addition of carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) was investigated. CNT-Epoxy and GNP-Epoxy Compact Tension (CT) samples were fabricated with 0.1% and 0.5% nanofiller weight concentrations. The potential synergistic effects of dual nanofiller reinforcements were also explored using CNT/GNP-Epoxy CT samples at a 1:3, 3:1 and 1:1 ratio of CNT:GNP. Displacement controlled CT tests were conducted according to ASTM D5045 test procedure and the critical stress intensity factor, $K_{IC}$, and the critical fracture energy, $G_{IC}$, were calculated for all the material systems. Significant enhancements relative to neat epoxy were observed in reinforced epoxies. Fracture surfaces were analyzed via scanning electron microscopy. Instances of CNT pullouts on the fracture surface were observed, indicating the occurrence of crack bridging. Furthermore, increased surface roughness, an indicator of crack deflection, was observed along with some crack bifurcations in the GNP-Epoxy samples. In the fourth chapter of Part I, the influence of pre-crack characteristics on the Mode-I fracture toughness of epoxy is investigated. Pre-crack characteristics such as pre-crack length, crack front shape, crack thickness and crack plane profile are evaluated and their influence on the peak load, fracture displacement, and the critical stress intensity factor, $K_{IC}$ is studied. A new method of razor blade tapping was used, which utilized a guillotine-style razor tapping device to initiate the pre-crack and through-thickness compression to arrest it. A new approach of quantitatively characterizing the crack front shape using a two-parameter function is introduced. Surface features present on the pre-crack surface are classified and their effects on the post crack initiation behavior of the sample are analyzed. This study aims to identify and increase the understanding of the various factors that cause variation in the fracture toughness data of polymeric materials, thus leading to more informed engineering design decisions and evaluations. Chapters six and seven of Part II investigate the SHM capabilities of dispersed MWCNTs in mock, inert, and active energetics. In these experimental investigations, the strain and damage sensing abilities of multi-walled carbon nanotube (MWCNT) networks embedded in the binder phase of polymer bonded energetics (PBEs) are evaluated. PBEs are a special class of particulate composite materials that consist of energetic crystals bound by a polymer matrix, wherein the polymer matrix serves to diminish the sensitivity of the energetic phase to accidental mechanical stimuli. The structural health monitoring (SHM) approach presented in this work exploits the piezoresistive properties of the distributed MWCNT networks. Major challenges faced during such implementation include the low binder concentrations of PBEs, presence of conductive/non-conductive particulate phases, high degree of heterogeneity in the PBE microstructure, and achieving the optimal MWCNT dispersion. In chapter seven, Ammonium Perchlorate (AP) crystals as the oxidizer, Aluminum grains as the metallic fuel, and Polydimethylsiloxane (PDMS) as the binder are used as the constituents for fabricating PBEs. To study the effect of each constituent on the MWCNT network's SHM abilities, various materials systems are comprehensively studied: MWCNT/PDMS (nBinder) materials are first evaluated to study the binder's electromechanical response, followed by AP/MWCNT/PDMS (inert nPBE) to assess the impact of AP addition, and finally, AP/AL/MWCNT/PDMS (active nPBE-AL) to evaluate the impact of adding conductive aluminum grains. Compression samples (ASTM D695) were fabricated and subjected to monotonic compression. Electrical resistance is recorded in conjunction with the mechanical test via an LCR meter. Gauge factors relating the change in normalized resistance to applied strain are calculated to quantify the electromechanical response. MWCNT dispersions, and mechanical failure modes are analyzed via scanning electron microscopy (SEM) imaging of the fracture surfaces. Correlations between the electrical behavior in response to the mechanical behavior are presented, and possible mechanisms that influence the electromechanical behavior are discussed. The results presented herein demonstrate the successful ability of MWCNT networks as structural health monitoring sensors capable of real-time strain and damage assessment of polymer bonded energetics. / Doctor of Philosophy / The discovery of carbon nanotubes in 1990s popularized a new area of research in materials science called Nanoscience. Carbon nanotubes (CNTs) are one of several forms of Carbon, meaning a differently structured carbon molecule in the same physical state similar to diamonds, graphite, and coal. In the following decades, several carbon based nanoparticles were discovered or engineered and with the discovery of Graphene (GNP) in 2010, carbon based nanoparticles were propelled as the most promising class of nanoparticles. High mechanical strength and stiffness, excellent electrical and thermal conductivity, and high strength to weight ratios are some of the unique abilities of CNTs and GNPs which allow their use in a wide array of applications from aerospace materials to electronic devices. In the current work presented herein, CNTs and GNPs are added to polymeric materials to create a nanocomposite material, where the term "composite" refers to a material prepared with two or more constituent materials. The effects of this nanoparticle addition (a.k.a reinforcement) on the mechanical properties of the nanocomposite polymer materials are studied. Specifically, efforts are focused on studying fracture toughness, a material property that describes the material's ability to resist crack growth. Fracture toughness is a critical material property often associated with material and structural failures, and as such it is very important for safe and reliable engineering design of structures, components, and materials. Moving from a single function (i.e. mechanical enhancement) to a more multi-functional role, taking advantage of the excellent electrical and mechanical abilities of CNTs, a structural health monitoring system is developed for use in polymer bonded energetics (eg. solid rocket propellants). When a material undergoes mechanical deformation or damage, the measured electrical properties of the material undergo some change as well. Using sensor networks built with multiple CNTs dispersed within a polymeric material, a whole structure can be made into an effective sensor where by simply monitoring the electrical properties, the extent of material deformation and damage can be known. Such a system is geared towards providing early warning of impending catastrophic material failures thus directly improving the safety during material handling and operations.

The purpose of this case study was to answer 5 primary questions in order to determine the impact (efficacy, efficiency, and value) of the educational intervention known as the mental skills training program (MSTP) as implemented with an NCAA Division I volleyball team. The primary evaluation questions are (1) Was individual and/or team performance enhanced during the season? (2) How did the intervention of the MSTP impact individual and team mental toughness? (3) How did the intervention of the MSTP impact team communication and team chemistry? (4) How did the coaches and student-athletes view the investment of time and effort (value/worth)? (5) Was the program delivered effectively and efficiently? The core mental skills that comprise the MSTP are goal setting, visualization, feelazation, energy management, and effective thinking which when integrated encourage mental toughness. The program evaluation contains an instructional design (ID) that incorporated a flexible curriculum to meet the weekly needs of the team. A modified Gerlach and Ely (1980) ID model is utilized to direct the design process and also as a prescriptive evaluation guide. The evaluation utilized quantitative instruments including surveys, questionnaires, and assessments of the effectiveness and efficiency of delivery by the mental skills trainer. Qualitative data includes interviews and field notes consisting of observations, member checks, and peer debriefing. The results of the data indicate individual performance and mental toughness were enhanced; team performance and mental toughness may have been improved. Team chemistry was enhanced while team communication was not. The program was considered valuable and worthwhile and was delivered effectively and efficiently. The decision components of the program yielded an 84.69% positive program evaluation rating. In discussion of these results, team communication may be improved with a greater emphasis on teambuilding early in the program. Gains in mental toughness exceeded expectations, and a foothold has been established for future research in this area. Regarding team performance, expanding categories in survey instruments may yield a more positive evaluation. Finally, program evaluation may provide a viable research vehicle for applied sport psychology to demonstrate the efficacy of mental skills training for performance enhancement. / Ph. D.

Yes / In this paper, a pyramidal horn antenna loaded with unit cell of metamaterial is proposed, designed and realized for L-band that including terrestrial digital audio broadcasting TDAB, GPS and GSM. The proposed antenna operates in the frequency range from 1.722 GHz to 1.931 GHz. The metamaterial is fabricated on a printed circuit board as Capacitive Loaded Loop (CLL). The work aims to exhibit the advantage of metamaterial loaded inside the horn antenna in terms of the gain enhancement of the radiation pattern and the resonant frequency shift towards lower frequency. The retrieval technique used show that the constitutive parameters of the unit cell as CLL have a zero index metamaterial (ZIM) from 1.34 GHz to 1.49 GHz and a near zero index of refraction from 1.495 GHz to 2 GHz, which is within the operating frequency of the horn antenna. The achieved results show that the total gain is improved over the frequency range. The simulation and the measurement are in good agreement.