Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Social and Behavioral Sciences (5481)
- Education (4383)
- Engineering (4149)
- Physical Sciences and Mathematics (3529)
- Arts and Humanities (3498)
-
- Life Sciences (3160)
- Medicine and Health Sciences (2242)
- Psychology (1664)
- Electrical and Computer Engineering (1170)
- Educational Leadership (1089)
- Sociology (976)
- Educational Administration and Supervision (796)
- Chemistry (779)
- History (716)
- Civil and Environmental Engineering (663)
- Communication (654)
- Mechanical Engineering (648)
- Biology (632)
- Environmental Sciences (627)
- Physics (617)
- Computer Sciences (567)
- Higher Education (553)
- Business (548)
- Animal Sciences (502)
- Biochemistry, Biophysics, and Structural Biology (488)
- Curriculum and Instruction (480)
- Public Affairs, Public Policy and Public Administration (454)
- Teacher Education and Professional Development (451)
- Clinical Psychology (440)
- Educational Assessment, Evaluation, and Research (431)
- Institution
-
- University of Mississippi (8605)
- University of Central Florida (6833)
- South Dakota State University (4806)
- University of Louisville (4690)
- East Tennessee State University (3783)
-
- University of Denver (2614)
- Duquesne University (2247)
- Abilene Christian University (1057)
- Stephen F. Austin State University (675)
- Coastal Carolina University (202)
- Xavier University of Louisiana (147)
- University of Health Sciences and Pharmacy in St. Louis (3)
- University of Memphis (2)
- Georgia Southern University (1)
- Keyword
-
- Morgridge College of Education (711)
- College of Arts Humanities and Social Sciences (659)
- Education (605)
- Daniel Felix Ritchie School of Engineering and Computer Science (398)
- College of Natural Science and Mathematics (259)
-
- Gender (212)
- Higher education (205)
- School administration (200)
- Josef Korbel School of International Studies (197)
- Leadership (189)
- Teaching and Learning Sciences (167)
- Psychology (165)
- Identity (151)
- Retention (150)
- Communication (143)
- Phenomenology (141)
- Women (136)
- Joint Ph.D. Program in Study of Religion (133)
- Race (127)
- Depression (124)
- Curriculum and Instruction (121)
- Mathematics (120)
- Technology (120)
- Machine learning (118)
- Stress (118)
- Simulation (114)
- Higher Education (110)
- Performance (109)
- Anthropology (105)
- Religion (104)
- Publication Year
- File Type
Articles 24301 - 24330 of 35665
Full-Text Articles in Entire DC Network
Experimental Analysis And Evaluation Of Tidy Tree Drawing Algorithms, Pankaj Mahajan
Experimental Analysis And Evaluation Of Tidy Tree Drawing Algorithms, Pankaj Mahajan
Electronic Theses and Dissertations
Tree Drawings have been used extensively in software engineering and many other business and computer applications. The basic structure of a tree allows for the organization and representation of complex information. Many commercial tools allow their users to draw or construct trees to represent a problem and/or its solution. Our focus is on dynamic trees - trees subject to frequent changes and redisplay in highly user-friendly interactive computer applications. Tree presentations in such interactive tools have to be precise and maintainable, which means, the tree presentations should maintain a particular structure so that user's mental perception of the tree is …
Automated Scenario Generation System In A Simulation, Hajime Tomizawa
Automated Scenario Generation System In A Simulation, Hajime Tomizawa
Electronic Theses and Dissertations
Developing training scenarios that induce a trainee to utilize specific skills is one of the facets of simulation-based training that requires significant effort. Simulation-based training systems have become more complex in recent years. Because of this added complexity, the amount of effort required to generate and maintain training scenarios has increased. This thesis describes an investigation into automating the scenario generation process. The Automated Scenario Generation System (ASGS) generates expected action flow as contexts in chronological order from several events and tasks with estimated time for the entire training mission. When the training objectives and conditions are defined, the ASGS …
Design And Implementation Of An Emission Spectroscopy Diagnostic In A High-Pressure Strand Burner For The Study Of Solid Propell, Jason Arvanetes
Design And Implementation Of An Emission Spectroscopy Diagnostic In A High-Pressure Strand Burner For The Study Of Solid Propell, Jason Arvanetes
Electronic Theses and Dissertations
The application of emission spectroscopy to monitor combustion products of solid rocket propellant combustion can potentially yield valuable data about reactions occurring within the volatile environment of a strand burner. This information can be applied in the solid rocket propellant industry. The current study details the implementation of a compact spectrometer and fiber optic cable to investigate the visible emission generated from three variations of solid propellants. The grating was blazed for a wavelength range from 200 to 800 nm, and the spectrometer system provides time resolutions on the order of 1 millisecond. One propellant formula contained a fine aluminum …
Automated Visual Database Creation For A Ground Vehicle Simulator, Pedro Claudio
Automated Visual Database Creation For A Ground Vehicle Simulator, Pedro Claudio
Electronic Theses and Dissertations
This research focuses on extracting road models from stereo video sequences taken from a moving vehicle. The proposed method combines color histogram based segmentation, active contours (snakes) and morphological processing to extract road boundary coordinates for conversion into Matlab or Multigen OpenFlight compatible polygonal representations. Color segmentation uses an initial truth frame to develop a color probability density function (PDF) of the road versus the terrain. Subsequent frames are segmented using a Maximum Apostiori Probability (MAP) criteria and the resulting templates are used to update the PDFs. Color segmentation worked well where there was minimal shadowing and occlusion by other …
Analysis Of Complexity And Coupling Metrics Of Subsystems In Large Scale Software Systems, Harish Ramakrishnan
Analysis Of Complexity And Coupling Metrics Of Subsystems In Large Scale Software Systems, Harish Ramakrishnan
Electronic Theses and Dissertations
Dealing with the complexity of large-scale systems can be a challenge for even the most experienced software architects and developers. Large-scale software systems can contain millions of elements, which interact to achieve the system functionality. Managing and representing the complexity involved in the interaction of these elements is a difficult task. We propose an approach for analyzing the reusability, maintainability and complexity of such a complex large-scale software system. Reducing the dependencies between the subsystems increase the reusability and decrease the efforts needed to maintain the system thus reducing the complexity of the system. Coupling is an attribute that summarizes …
The Effects On Operator Performance And Workload When Gunnery And Robotic Control Tasks Are Performed Concurrently, Carla Joyner
The Effects On Operator Performance And Workload When Gunnery And Robotic Control Tasks Are Performed Concurrently, Carla Joyner
Electronic Theses and Dissertations
The purpose of this research was to examine operator workload and performance in a high risk, multi-task environment. Specifically, the research examined if a gunner of a Future Combat System, such as a Mounted Combat System, could effectively detect targets in the immediate environment while concurrently operating robotic assets in a remote environment. It also analyzed possible effects of individual difference factors, such as spatial ability and attentional control, on operator performance and workload. The experimental conditions included a gunner baseline and concurrent task conditions where participants simultaneously performed gunnery tasks and one of the following tasks: monitor an unmanned …
Every Cloud Has A Silver Lining: Positive Effects Of Deviant Coworkers, Gergana Markova
Every Cloud Has A Silver Lining: Positive Effects Of Deviant Coworkers, Gergana Markova
Electronic Theses and Dissertations
The purpose of this study was to recognize and explore the reactions of employees to a deviant coworker. Specifically, I focused on the potential positive effects for employees who are in the presence of a coworker perceived as deviant, dysfunctional, or negative. Consistent with a labeling perspective on deviance, I argued that an employee may become a deviant as a result of social construction, fostered either by observed norm violations or the perceived dissimilarity of this person. Drawing on diverse theories from social psychology and sociology, I hypothesized that in the presence of a deviant coworker, other employees may have …
Performance Efficacy Using A Comparison Of Commerical And In-House Y-Str Multiplex Systems For Operational Use, Kathleen Mayntz-Press
Performance Efficacy Using A Comparison Of Commerical And In-House Y-Str Multiplex Systems For Operational Use, Kathleen Mayntz-Press
Electronic Theses and Dissertations
It is routine for the forensic scientist to obtain a genetic profile of an individual from DNA recovered from a biological stain deposited at a crime scene. In contrast, only a limited number of laboratories in the United States have the capability of performing Y-STR analysis in casework. In order to aid in facilitating the transfer of Y-STR technology to the crime laboratory community for operational use, a comparison between commercial products from three main vendors (Applied Biosystems AmpFLSTR Yfiler PCR Amplification Kit, Promega PowerPlex - Y System, Reliagene Y-PLEX 12) and two in-house Y-STR multiplexes (MPI and MPB) commenced. …
Values As A Component Of Leadership And Their Relationship To Organizational Efficacy And Culture; An Ethnographic Study Of Leaders' Influence At A Pennsylvania Non-Profit Organization 1965-2005, Emma Lee Mccloskey
Electronic Theses and Dissertations
An ethnographic case study approach of a Pennsylvania non-profit organization was used to develop an understanding of leaders' values as they relate to organizational culture and organizational efficacy using testimony of organizational leaders and followers as well as organizational documents. Past Executive Directors, the current Executive Director, past Chairpersons of the Board of Directors and a random sample of Leadership Council members were interviewed using a semi-structured interview guide to answer the following research questions:
How, if at all, do the values of a leader affect the organizational efficacy?
How, if at all, do the values of a leader affect …
Design And Fabrication Of A Full-Featured Labscale Hybrid Rocket Engine, Kyle Platt
Design And Fabrication Of A Full-Featured Labscale Hybrid Rocket Engine, Kyle Platt
Electronic Theses and Dissertations
The design, development, integration and testing of a full-featured, Lab-Scale Hybrid Rocket Engine was not only envisioned to be the chosen method of putting student payloads into space, but to be an invaluable teaching resource. The subject of the present thesis is the analysis, design, development, integration and demonstration of a lab-scale hybrid rocket motor. The overarching goal of this project was to establish a working developmental lab model from which further research can be accomplished. The lab model was specifically designed to use a fuel source that could be studied in normal laboratory conditions. As such, the rocket engine …
Automated Adaptive Data Center Generation For Meshless Methods, Eric Mitteff
Automated Adaptive Data Center Generation For Meshless Methods, Eric Mitteff
Electronic Theses and Dissertations
Meshless methods have recently received much attention but are yet to reach their full potential as the required problem setup (i.e. collocation point distribution) is still significant and far from automated. The distribution of points still closely resembles the nodes of finite volume-type meshes and the free parameter, c, of the radial-basis expansion functions (RBF) still must be tailored specifically to a problem. The localized meshless collocation method investigated requires a local influence region, or topology, used as the expansion medium to produce the required field derivatives. Tests have shown a regular cartesian point distribution produces optimal results, however, in …
Analyis Of Airborne Microwave Polarimetric Radiometer Measurements In The Presence Of Dynamic Platform Attitude Errors, Jean Yves Kabore
Analyis Of Airborne Microwave Polarimetric Radiometer Measurements In The Presence Of Dynamic Platform Attitude Errors, Jean Yves Kabore
Electronic Theses and Dissertations
There are numerous applications for airborne imaging systems in remote sensing, and this thesis deals with a new microwave polarimetric radiometer technique for inferring ocean surface wind direction [3, 5, 7]. This technique is based upon the anisotropy of the polarized ocean blackbody emissions at microwave frequencies relative to the azimuth angle between the microwave radiometer antenna "look" direction and the direction of the wind. Because of the weak wind direction signature, it is important that all systematic brightness temperature (Tb) errors be eliminated, especially those that vary with the radiometer antenna scan position (look direction). This can be accomplished …
Polymer-Derived Ceramics: Electronic Properties And Application, Weixing Xu
Polymer-Derived Ceramics: Electronic Properties And Application, Weixing Xu
Electronic Theses and Dissertations
In this work, we studied the electronic behavior of polymer-derived ceramics (PDCs) and applied them for the synthesis of carbon nanotube reinforced ceramic nanocomposites and ceramic MEMS (Micro-Electro-Mechanical Systems) structures. Polymer-derived SiCN ceramics were synthesized by pyrolysis of a liquid polyureasilazane with dicumyl peroxide as thermal initiator. The structural evolution during pyrolysis and post-annealing was studied using FTIR, solid state NMR and Raman. The results revealed that the resultant ceramics consisted of SiCxNx-4 as major building units. These units were connected with each other through C-C/C=C bonds or by shearing N/C. The amount of sp2 free carbon strongly depends on …
Demonstrating Reflectarray Behavior At Infrared, James Ginn
Demonstrating Reflectarray Behavior At Infrared, James Ginn
Electronic Theses and Dissertations
Reflectarrays are traditionally passive, planar microstrip antenna devices designed for reflected phase manipulation at each individual antenna element making up the array. By varying the phase response across the surface with the antenna elements, reflectarrays allows a planar surface to exhibit electromagnetically an arbitrary geometry, such as a spherical surface. Initially proposed as a low-cost replacement for bulky parabolic reflectors, reflectarrays have been successfully developed and utilized at both RF and millimeter-wave frequencies. From the standpoint of an optical systems designer, adapting low-frequency reflectarray technology to develop a sub-millimeter and infrared reflectarray (SMIR) would provide a highly desirable alternative to …
Framework For Cost Modeling A Supply Chain, Nabeel Yousef
Framework For Cost Modeling A Supply Chain, Nabeel Yousef
Electronic Theses and Dissertations
Researchers are interested in value chain analysis to identify the different opportunities for cost savings. The literature have been narrow in scope and addressed specific problems; however none has addressed the need for a general framework that can be used as a standard template in the supply chain cost management and optimization, though Dekker and Goor (2000) said that the goal was to develop a model that would allow direct comparison of specific activities between firms, such as warehousing activities costs. There was no indication in the literature of a cost model that can identify all costs and cost drivers …
The Use Of Pc Based Simulation Systems In The Training Of Army Infantry Officers - An Evaluation Of The Rapid Decision Trainer, Thomas Lucario
The Use Of Pc Based Simulation Systems In The Training Of Army Infantry Officers - An Evaluation Of The Rapid Decision Trainer, Thomas Lucario
Electronic Theses and Dissertations
This research considers two modes of training Army infantry officers in initial training to conduct a platoon live fire exercise. Leaders from groups that were training with the current classroom training methods were compared to leaders from groups whose training was augmented with a PC based training system known as the Rapid Decision Trainer (RDT). The RDT was developed by the US Army Research Development and Engineering Command for the purpose of aiding in the training of tactical decision making and troop leading procedures of officers in the initial levels of training to become rifle platoon leaders. The RDT allows …
Laser Metallization And Doping For Silicon Carbide Diode Fabrication And Endotaxy, Zhaoxu Tian
Laser Metallization And Doping For Silicon Carbide Diode Fabrication And Endotaxy, Zhaoxu Tian
Electronic Theses and Dissertations
Silicon carbide is a promising semiconductor material for high voltage, high frequency and high temperature devices due to its wide bandgap, high breakdown electric field strength, highly saturated drift velocity of electrons and outstanding thermal conductivity. With the aim of overcoming some challenges in metallization and doping during the fabrication of silicon carbide devices, a novel laser-based process is provided to direct metallize the surface of silicon carbide without metal deposition and dope in silicon carbide without high temperature annealing, as an alternative to the conventional ion implantation, and find applications of this laser direct write metallization and doping technique …
Development Of Thermally Processed Nanocomposites With Controlled Surfaces, Petya Georgieva
Development Of Thermally Processed Nanocomposites With Controlled Surfaces, Petya Georgieva
Electronic Theses and Dissertations
The ever increasing need for technology development requires the integration of inexpensive, light weight and high strength materials which are able to meet the high standards and specifications for various engineering applications. The intention of this work is to show that the suitable material selection and the utilization of plasma spray processing can be of potential interest to a large number of industrial, biomedical and everyday life applications. This research demonstrates also that plasma processing is a promising engineering tool for multifunctional coatings and near-net-shape manufacturing. Further, the theoretical and experimental results are combined in order to explain the mechanisms …
Nonparametric Multivariate Statistical Process Control Using Principal Component Analysis And Simplicial Depth, Luis Beltran
Nonparametric Multivariate Statistical Process Control Using Principal Component Analysis And Simplicial Depth, Luis Beltran
Electronic Theses and Dissertations
Although there has been progress in the area of Multivariate Statistical Process Control (MSPC), there are numerous limitations as well as unanswered questions with the current techniques. MSPC charts plotting Hotelling's T2 require the normality assumption for the joint distribution among the process variables, which is not feasible in many industrial settings, hence the motivation to investigate nonparametric techniques for multivariate data in quality control. In this research, the goal will be to create a systematic distribution-free approach by extending current developments and focusing on the dimensionality reduction using Principal Component Analysis. The proposed technique is different from current approaches …
High Speed Turbo Tcm Ofdm For Uwb And Powerline System, Yanxia Wang
High Speed Turbo Tcm Ofdm For Uwb And Powerline System, Yanxia Wang
Electronic Theses and Dissertations
Turbo Trellis-Coded Modulation (TTCM) is an attractive scheme for higher data rate transmission, since it combines the impressive near Shannon limit error correcting ability of turbo codes with the high spectral efficiency property of TCM codes. We build a punctured parity-concatenated trellis codes in which a TCM code is used as the inner code and a simple parity-check code is used as the outer code. It can be constructed by simple repetition, interleavers, and TCM and functions as standard TTCM but with much lower complexity regarding real world implementation. An iterative bit MAP decoding algorithm is associated with the coding …
Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup
Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup
Electronic Theses and Dissertations
The threat of terrorist incidents is higher than ever before and devastating acts, such as the terrorist attacks on the World Trade Center and the Pentagon, have left many concerns about the possibility of future incidents and their potential impact. Unlike some natural disasters that can be anticipated, terrorist attacks are sudden and unexpected. Even if sometimes we do have partial information about a possible attack, it is generally not known exactly where, when, or how an attack will occur. This lack of information posses great challenges on those responsible for security, specifically, on their ability to respond fast, whenever …
Magnetic Properties Of Sputter Deposited Fe-Based Amorphous Thin Films For Resonator Application, Chaitali China
Magnetic Properties Of Sputter Deposited Fe-Based Amorphous Thin Films For Resonator Application, Chaitali China
Electronic Theses and Dissertations
In this study we investigate the magnetic properties of Fe-based amorphous thin films. Fe1-x-y-zBxSiyCz, Fe80-xNixB20, Fe80-xMnxB20, and Fe73-xMnxB27 films were deposited on silicon and glass substrates in a DC and RF magnetron sputtering system. Inductive magnetic measurements were performed to investigate the magnetic properties, including induced anisotropy and magnetostriction, of the as-deposited and annealed films using an M-H Looper. The chemical composition of the films was characterized using secondary ion mass spectroscopy (SIMS). The physical thickness of the films was determined by use of a stylus profilometer. The M-H Looper studies indicated that the induced anisotropy (Hk) depends strongly on …
An Authentic Ecg Simulator, Paul Michalek
An Authentic Ecg Simulator, Paul Michalek
Electronic Theses and Dissertations
An ECG (electrocardiogram) simulator is an electronic tool that plays an essential role in the testing, design, and development of ECG monitors and other ECG equipment. Principally an ECG simulator provides ECG monitors with an electrical signal that emulates the human heart's electrical signal so that the monitor can be tested for reliability and important diagnostic capabilities. However, the current portable commercially available ECG simulators are lacking in their ability to fully test ECG monitors. Specifically, the portable simulators presently on the market do not produce authentic ECG signals but rather they endeavor to create the ECG signals mathematically. They …
Design Optimization Of Solid Rocket Motor Grains For Internal Ballistic Performance, Roger Hainline
Design Optimization Of Solid Rocket Motor Grains For Internal Ballistic Performance, Roger Hainline
Electronic Theses and Dissertations
The work presented in this thesis deals with the application of optimization tools to the design of solid rocket motor grains per internal ballistic requirements. Research concentrated on the development of an optimization strategy capable of efficiently and consistently optimizing virtually an unlimited range of radial burning solid rocket motor grain geometries. Optimization tools were applied to the design process of solid rocket motor grains through an optimization framework developed to interface optimization tools with the solid rocket motor design system. This was done within a programming architecture common to the grain design system, AML. This commonality in conjunction with …
Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai
Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai
Electronic Theses and Dissertations
In this fast paced digital age, a vast amount of videos are produced every day, such as movies, TV programs, personal home videos, surveillance video, etc. This places a high demand for effective video data analysis and management techniques. In this dissertation, we have developed new techniques for segmentation, linking and understanding of video scenes. Firstly, we have developed a video scene segmentation framework that segments the video content into story units. Then, a linking method is designed to find the semantic correlation between video scenes/stories. Finally, to better understand the video content, we have developed a spatiotemporal attention detection …
Analysis Of Various Car-Truck Crash Types Based On Ges And Fars Crash Databases Using Mutlinomial And Binary Logit Model, Kranthi Kiran Mannila
Analysis Of Various Car-Truck Crash Types Based On Ges And Fars Crash Databases Using Mutlinomial And Binary Logit Model, Kranthi Kiran Mannila
Electronic Theses and Dissertations
Each year about 400,000 trucks are involved in motor vehicle crashes. Crashes involving a car and truck have always been a major concern due to the heavy fatality rates. These types of crashes result in about 60 percent of all fatal truck crashes and two-thirds of all police-reportable truck crashes. Car-truck crashes need to be analyzed further to study the trends for a car-truck crash and develop some countermeasures to lower these crashes. Various types of car-truck crashes are analyzed in this study and the effects of various roadway/environment factors and variables related to driver characteristics in these car-truck crashes …
A Non-Isolated Half Bridge Buck-Based Converter For Vrm Application And Small Signal Modeling Of A Non-Conventional Two Phase Bu, Majd Batarseh
A Non-Isolated Half Bridge Buck-Based Converter For Vrm Application And Small Signal Modeling Of A Non-Conventional Two Phase Bu, Majd Batarseh
Electronic Theses and Dissertations
This dissertation is about treatment of the nonbiodegradable organic content of landfill leachate by chemical oxidation combined with biological treatment. It is divided into three parts. In the first part, ferrate was compared to Fenton's reagent for the purpose of removing non-biodegradable organic compounds from mature leachate. Oxidation conditions (time, pH, and dose) were optimized to yield maximum organic removal using two leachate samples from 20 and 12-year old solid waste cells. Results from this research demonstrated that ferrate and Fenton's reagent had similar optimum pH ranges (3-5), but different organic removal capacities, ranging from 54 to 79 % of …
A Third-Order Differential Steering Robot And Trajectory Generation In The Presence Of Moving Obstacles, Vatana An
Electronic Theses and Dissertations
In this thesis, four robots will be used to implement a collision-free trajectory planning/replanning algorithm. The existence of a chained form transformation so that the robot's model can be control in canonical form will be analyzed and proved. A trajectory generation for obstacles avoidance will be derived, simulated, and implemented. A specific PC based control algorithm will be developed. Chapter two describes two wheels differential drive robot modeling and existence of controllable canonical chained form. Chapter 3 describes criterion for avoiding dynamic objects, a feasible collision-free trajectory parameterization, and solution to steering velocity. Chapter 4 describes robot implementation, pc wireless …
Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer
Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer
Electronic Theses and Dissertations
The need for real-time video analysis is rapidly increasing in today's world. The decreasing cost of powerful processors and the proliferation of affordable cameras, combined with needs for security, methods for searching the growing collection of video data, and an appetite for high-tech entertainment, have produced an environment where video processing is utilized for a wide variety of applications. Tracking is an element in many of these applications, for purposes like detecting anomalous behavior, classifying video clips, and measuring athletic performance. In this dissertation we focus on augmented reality, but the methods and conclusions are applicable to a wide variety …
Driver-Gas Tailoring For Test-Time Extension Using Unconventional Driver Mixtures, Anthony Amadio
Driver-Gas Tailoring For Test-Time Extension Using Unconventional Driver Mixtures, Anthony Amadio
Electronic Theses and Dissertations
To study combustion chemistry at low temperatures in a shock tube, it is of great importance to increase experimental test times, and this can be done by tailoring the interface between the driver and driven gases. Using unconventional driver-gas tailoring with the assistance of tailoring curves, shock-tube test times were increased from 1 to 15 ms for reflected-shock temperatures below 1000 K. Provided in this thesis is the introduction of tailoring curves, produced from a 1-D perfect gas model for a wide range of driver gases and the production and demonstration of successful driver mixtures containing helium combined with either …