Hands-On Applications: Real Option Super Lattice Solver Software

Keyword(s):  
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.


Author(s):  
M.D. Bentzon ◽  
J. v. Wonterghem ◽  
A. Thölén

We report on the oxidation of a magnetic fluid. The oxidation results in magnetic super lattice crystals. The “atoms” are hematite (α-Fe2O3) particles with a diameter ø = 6.9 nm and they are covered with a 1-2 nm thick layer of surfactant molecules.Magnetic fluids are homogeneous suspensions of small magnetic particles in a carrier liquid. To prevent agglomeration, the particles are coated with surfactant molecules. The magnetic fluid studied in this work was produced by thermal decomposition of Fe(CO)5 in Declin (carrier liquid) in the presence of oleic acid (surfactant). The magnetic particles consist of an amorphous iron-carbon alloy. For TEM investigation a droplet of the fluid was added to benzine and a carbon film on a copper net was immersed. When exposed to air the sample starts burning. The oxidation and electron irradiation transform the magnetic particles into hematite (α-Fe2O3) particles with a median diameter ø = 6.9 nm.


Author(s):  
L. S. Chumbley ◽  
M. Meyer ◽  
K. Fredrickson ◽  
F.C. Laabs

The Materials Science Department at Iowa State University has developed a laboratory designed to improve instruction in the use of the scanning electron microscope (SEM). The laboratory makes use of a computer network and a series of remote workstations in a classroom setting to provide students with increased hands-on access to the SEM. The laboratory has also been equipped such that distance learning via the internet can be achieved.A view of the laboratory is shown in Figure 1. The laboratory consists of a JEOL 6100 SEM, a Macintosh Quadra computer that acts as a server for the network and controls the energy dispersive spectrometer (EDS), four Macintosh computers that act as remote workstations, and a fifth Macintosh that acts as an internet server. A schematic layout of the classroom is shown in Figure 2. The workstations are connected directly to the SEM to allow joystick and computer control of the microscope. An ethernet connection between the Quadra and the workstations allows students seated there to operate the EDS. Control of the microscope and joystick is passed between the workstations by a switch-box assembly that resides at the microscope console. When the switch-box assembly is activated a direct serial line is established between the specified workstation and the microscope via the SEM’s RS-232.


Author(s):  
Ying-Chiao Tsao

Promoting cultural competence in serving diverse clients has become critically important across disciplines. Yet, progress has been limited in raising awareness and sensitivity. Tervalon and Murray-Garcia (1998) believed that cultural competence can only be truly achieved through critical self-assessment, recognition of limits, and ongoing acquisition of knowledge (known as “cultural humility”). Teaching cultural humility, and the value associated with it remains a challenging task for many educators. Challenges inherent in such instruction stem from lack of resources/known strategies as well as learner and instructor readiness. Kirk (2007) further indicates that providing feedback on one's integrity could be threatening. In current study, both traditional classroom-based teaching pedagogy and hands-on community engagement were reviewed. To bridge a gap between academic teaching/learning and real world situations, the author proposed service learning as a means to teach cultural humility and empower students with confidence in serving clients from culturally/linguistically diverse backgrounds. To provide a class of 51 students with multicultural and multilingual community service experience, the author partnered with the Tzu-Chi Foundation (an international nonprofit organization). In this article, the results, strengths, and limitations of this service learning project are discussed.


ASHA Leader ◽  
2012 ◽  
Vol 17 (9) ◽  
pp. 55-55
Author(s):  
Kimberly Abts
Keyword(s):  

2017 ◽  
Vol 2 (18) ◽  
pp. 28-41
Author(s):  
Kelli M. Watts ◽  
Laura B. Willis

Telepractice, defined by the American Speech-Language-Hearing Association (ASHA, n.d.) as “the application of telecommunications technology to the delivery of professional services at a distance by linking clinician to client, or clinician to clinician, for assessment, intervention, and/or consultation,” is a quickly growing aspect of practicing audiology. However, only 12% of audiologists are involved in providing services via telepractice (REDA International, Inc., 2002). Lack of knowledge regarding telepractice has been cited as one of the reasons many audiologists do not use telepractice to provide audiology services. This study surveyed audiology doctoral students regarding their opinions about the use of telepractice both before and after their opportunity to provide services via telepractice sessions. The authors expected that by providing students the opportunity to have hands-on training in telepractice with supervision, they would be more open to using telepractice after becoming licensed audiologists. Overall, the data indicates benefits of exposing students to telepractice while they are in graduate school.


2008 ◽  
Vol 29 (3) ◽  
pp. 134-147 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Nicolas Sander

University dropout is a politically and economically important factor. While a number of studies address this issue cross-sectionally by analyzing different cohorts, or retrospectively via questionnaires, few of them are truly longitudinal and focus on the individual as the unit of interest. In contrast to these studies, an individual differences perspective is adopted in the present paper. For this purpose, a hands-on introduction to a recently proposed structural equation (SEM) approach to discrete-time survival analysis is provided ( Muthén & Masyn, 2005 ). In a next step, a prospective study with N = 1096 students, observed across four semesters, is introduced. As expected, average university grade proved to be an important predictor of future dropout, while high-school grade-point average (GPA) yielded no incremental predictive validity but was completely mediated by university grade. Accounting for unobserved heterogeneity, three latent classes could be identified with differential predictor-criterion relations, suggesting the need to pay closer attention to the composition of the student population.


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