The extraordinary Hall effect in coherent epitaxial tau (Mn,Ni)Al thin films on GaAs

Ultrathin coherent epitaxial films of ferromagnetic tau(Mn,Ni)0.60Al0.40 have been grown by molecular beam epitaxy on GaAs substrates. X-ray scattering and cross-sectional transmission electron microscopy measurements confirm that the c axis of the tetragonal tau unit cell is aligned normal to the (001) GaAs substrate. Measurements of the extraordinary Hall effect (EHE) show that the films are perpendicularly magnetized, exhibiting EHE resistivities saturating in the range of 3.3-7.1 muOMEGA-cm at room temperature. These values of EHE resistivity correspond to signals as large as +7 and -7 mV for the two magnetic states of the film with a measurement current of 1 mA. Switching between the two magnetic states is found to occur at distinct field values that depend on the previously applied maximum field. These observations suggest that the films are magnetically uniform. As such, tau(Mn,Ni)Al films may be an excellent medium for high-density storage of binary information

Non-Volatile Memory Characteristics of Submicrometre Hall Structures Fabricated in Epitaxial Ferromagnetic MnAl Films on GaAs

Hall-effect structures with submicrometre linewidths (<0.3pm) have been fabricated in ferromagnetic thin films of Mn[sub 0.60]Al[sub 0.40] which are epitaxially grown on a GaAs substrate. The MnAl thin films exhibit a perpendicular remanent magnetisation and an extraordinary Hall effect with square hysteretic behaviour. The presence of two distinct stable readout states demonstrates the potential of using ultrasmall ferromagnetic volumes for electrically addressable, nonvolatile storage of digital information

Epitaxial-tau(Mn,Ni)Al/(Al,Ga)As heterostructures: Magnetic and magneto-optic properties

Ferromagnetic Perpendicularly magnetized epitaxial thin films of tau (Mn,Ni)AI have been successfully grown on AlAs/GaAs heterostructures by molecular beam epitaxy. We have investigated the polar Kerr rotation and magnetization of tau MnAl and (Mn,Ni) Al as a function of Mn and Ni concentration. The largest polar Kerr rotation and remnant magnetization were obtained for Mn0.5Al0.5 thin films with values of 0.16-degrees and 224 emu/cm3, respectively. We observed that the Kerr rotation and magnetization remained constant with Ni additions up to about 12 at. % and subsequently decreased with further Ni additions. We discuss these results and one possible method of enhancing the Kerr rotation

It\u27s Not What You Pay; It\u27s What It Costs You. A Geotechnical Engineering Case Study

The project consists of a middle school constructed on a previously undeveloped site. Site development required leveling a mountain ridge and perimeter tills up to 150 feet deep to create the relatively level 15 acre building site. Access to the site required a 1000 foot long side hill road from the adjacent main highway. Neither the owner nor the design team obtained geotechnical investigations of the site. As a result, they failed to consider the impact of the geologic setting on seepage, ground water flow, and slope stability. Near the end of construction, slope instabilities occurred in a cut section of the entrance road and one of the major embankment sections. The owner, the county school board, hired the writer to determine the cause of the instabilities and provide testimony in their ongoing litigation. This paper summarizes the site conditions and project history, describes the writer\u27s investigation, describes the dispute resolution processes, and presents two procedural lessons learned from the case: the importance of qualified professional geotechnical advice, and the inherent and sometimes unrecognized value of ADR procedures

Role of Electric Utility Companies in Economic Development Within Deregulation

This research seeks to determine if electric utilities participate in economic development, and if so, how might the trend of electric deregulation affect that relationship. The researcher reviewed the academic literature to determine that electric utilities do, in fact, participate in economic development and significantly contribute to economic growth. They participate in all areas of economic development, including business attraction, business retention and expansion, and community development; they arguably influence business development and economic vibrancy more than any alternative business in the community. Since 1992, electric deregulation has influenced the way these utilities participate in economic development. State governments intend to stimulate the economy by diverting from electric regulation, governmental control over the industry, to electric deregulation, open market competition. However, previous electric deregulation attempts, such as in California and Texas, cause analyst to question if deregulation benefits the economy. The researcher further examined these deregulation attempts to determine if, in fact, they did affect the role of electric utilities in economic development. Deregulation did impact the way electric utilities participated in economic development in these states. Subsequently, the researcher interviewed ten electric utility directors, five from regulated states and five from deregulated states, and conducted a website analysis of twenty electric utility company websites: ten regulated states and ten deregulated states. The primary research questions consisted of: why do electric utility companies participate in economic development, and how does deregulation change the role of electric utilities in economic development. Electric utilities participate in economic development to maximize profits, and electric utilities in deregulated states actually participate in economic development less than electric utilities in regulated states. EUCs in deregulated states assist economic development rather than lead it, by working as an extension to the EDO. Unlike EUCs in deregulated states, EUCs in regulated states emphasized their proactive efforts to uncover leads, visit potential prospects, pursue opportunities, etc. Ultimately, electric deregulation detracts from electric utility company participation in economic development

The Mississippi School Funding Formula: A Study of Adequacy

The purpose of this was to examine the relationship between Mississippi public school district per pupil funding disaggregated by funding source (total, federal, state, and local) and student academic achievement gaps within districts based on poverty and race. Pearson\u27s correlational coefficient was used to assess the relationship across 139 Mississippi school districts during fiscal year 2019. State Special Schools, Charter Schools, and Agriculture Schools were excluded from the analysis. School districts lacking a sufficient number of African American and Economically Disadvantaged children to calculate a school proficiency score in ELA and Math were also removed. Thus, the analysis consisted of 122 districts in ELA and 87 in Math. Federal and local per pupil funding reported a more significant impact on closing achievement gaps between Economically Disadvantaged and non-Economically Disadvantaged and African American and non-African American white students. The least correlated predictors were state-level and total per pupil funding. The research findings are consistent with prior research findings advocating the importance of targeting school funding to the academic needs of all children because targeted funds have a greater impact on raising the achievement levels of children based on poverty and race

The Benefits of Offering Classroom Piano Lessons as Part of the Curriculum in Public Elementary School

The purpose of this study is to determine the potential benefits of offering classroom piano lessons as part of the curriculum in public elementary schools. The research reviews the educational, neurological, and cultural potential benefits a child may receive if they study the piano. Further study examines the availability for teachers to receive training in teaching group piano, the methods of setting up a piano classroom, and materials needed for such a program in the school system. Records of the history of group lessons showed that this method of teaching has had periods of success and periods of decline in the United States. The times that suffered from a downfall in the program are attributed mainly to times of war and financial decline. Advocates such as Raymond Burrows have furthered the concept, as well as Robert Pace, whose work eventually has led to the ongoing training of teachers across America through seminars and music journal articles. Qualitative research consisted of interviews with three participants who currently or previously taught piano lessons in a public or private school system. The results of this study indicated the teachers’ opinions of group piano lessons varied according to their own experience. The analysis of the data indicated that teachers who have school systems that include a piano class in the curriculum have greater success. Research determined the existence of a difference of opinion as to whether group lessons or private lessons are the best methods of teaching students

Computer-Aided Strategies for Determining the Amino Acid Composition of Medium for Chinese Hamster Ovary Cell-Based Biomanufacturing Platforms.

Chinese hamster ovary (CHO) cells are used for the production of the majority of biopharmaceutical drugs, and thus have remained the standard industry host for the past three decades. The amino acid composition of the medium plays a key role in commercial scale biologics manufacturing, as amino acids constitute the building blocks of both endogenous and heterologous proteins, are involved in metabolic and non-metabolic pathways, and can act as main sources of nitrogen and carbon under certain conditions. As biomanufactured proteins become increasingly complex, the adoption of model-based approaches become ever more popular in complementing the challenging task of medium development. The extensively studied amino acid metabolism is exceptionally suitable for such model-driven analyses, and although still limited in practice, the development of these strategies is gaining attention, particularly in this domain. This paper provides a review of recent efforts. We first provide an overview of the widely adopted practice, and move on to describe the model-driven approaches employed for the improvement and optimization of the external amino acid supply in light of cellular amino acid demand. We conclude by proposing the likely prevalent direction the field is heading towards, providing a critical evaluation of the current state and the future challenges and considerations