Free electron lasers for transmission of energy in space

A one-dimensional resonant-particle model of a free electron laser (FEL) is used to calculate laser gain and conversion efficiency of electron energy to photon energy. The optical beam profile for a resonant optical cavity is included in the model as an axial variation of laser intensity. The electron beam profile is matched to the optical beam profile and modeled as an axial variation of current density. Effective energy spread due to beam emittance is included. Accelerators appropriate for a space-based FEL oscillator are reviewed. Constraints on the concentric optical resonator and on systems required for space operation are described. An example is given of a space-based FEL that would produce 1.7 MW of average output power at 0.5 micrometer wavelength with over 50% conversion efficiency of electrical energy to laser energy. It would utilize a 10 m-long amplifier centered in a 200 m-long optical cavity. A 3-amp, 65 meV electrostatic accelerator would provide the electron beam and recover the beam after it passes through the amplifier. Three to five shuttle flights would be needed to place the laser in orbit

Travel to extraterrestrial bodies over time: some exploratory analyses of mission data

This paper discusses data pertaining to space missions to astronomical bodies beyond earth. The analyses provide summarizing facts and graphs obtained by mining data about (1) missions launched by all countries that go to the moon and planets, and (2) Earth satellites obtained from a Union of Concerned Scientists (UCS) dataset and lists of publically available satellite data

Compensation in epitaxial cubic SiC films

Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition on SiC substrates are reported. The temperature dependent carrier concentrations indicate that the samples are highly compensated. Donor ionization energies, E sub D, are less than one half the values previously reported. The values for E sub D and the donor concentration N sub D, combined with results for small bulk platelets with nitrogen donors, suggest the relation E sub D (N sub D) = E sub D(O) - alpha N sub N sup 1/3 for cubic SiC. A curve fit gives alpha is approx 2.6x10/5 meV cm and E sub D (O) approx 48 meV, which is the generally accepted value of E sub D(O) for nitrogen donors in cubic SiC

Music Therapy in US Corrections: Philosophy, Practice, and Protocols of Music Therapists Working with Incarcerated People in the US

Although the United States has the highest incarceration rate in the world and music therapy has existed in U.S. correctional facilities for almost a century, little is known about music therapists who provide services to people who are incarcerated. Exploration in this area is important as it could help inform clinical practice, music therapy curriculum, and potentially influence policy in the treatment of inmates. This study explores the philosophy, practices, and protocols of music therapists working in the U.S. corrections system. Board-certified music therapists ( N = 542) completed an online survey in which they indicated their reasons for working or not working in corrections. Participants who worked in corrections (n = 52) answered additional questions about their religious beliefs and political affiliation, music therapy practices in corrections, and protocols at their facility related to provision of music therapy services. The results of this survey revealed differences in demographic variables for music therapists who worked in prisons, who were significantly more likely to be men, χ2 (1) = 6.57, p = .015, or under-represented racial minorities, χ2 (1) = 5.82, p = .021, than music therapists who did not work in prisons, who were representative of music therapists in the U.S. (almost 90% white women). The majority of respondents who worked in corrections reported they were Democrats and more than half reported that their religious and/or spiritual views did not influence their decision to work in corrections. Music therapists most frequently addressed emotional awareness, impulse control, and self-awareness through music listening, discussion, and playing instruments. We discuss results in the context of current efforts to improve rehabilitation and treatment services within the U.S. correctional system

A Validated Reversed-Phase HPLC Method for the Determination of Atorvastatin Calcium in Tablets

A Reversed-Phase Liquid Chromatographic (RP-LC) assay method was developed for the quantitative determination of atorvastatin calcium in the presence of its degradation products. The assay involved an isocratic elution of atorvastatin calcium in a LiChroCARTR 250*4 mm HPLC Cartridge LiChrospherR 100 RP-18 (5 μm) column using a mobile phase consisting of 0.1% acetic acid solution: acetonitrile (45:55, v/v), pH = 3.8. The flow rate was 0.8 mL/min and the analytes monitored at 246 nm. The assay method was found to be linear from 8.13 to 23.77 μg/mL. All the validation parameters were within the acceptance range. The developed method was successfully applied to estimate the amount of atorvastatin calcium in tablets.Fil: Simionato, Laura Daniela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Ferello, L.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Stamer. S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Repetto, M. F.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Zubata, P. D.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Segall, Adriana Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

A molecular simulation analysis of producing monatomic carbon chains by stretching ultranarrow graphene nanoribbons

Atomistic simulations were utilized to develop fundamental insights regarding the elongation process starting from ultranarrow graphene nanoribbons (GNRs) and resulting in monatomic carbon chains (MACCs). There are three key findings. First, we demonstrate that complete, elongated, and stable MACCs with fracture strains exceeding 100% can be formed from both ultranarrow armchair and zigzag GNRs. Second, we demonstrate that the deformation processes leading to the MACCs have strong chirality dependence. Specifically, armchair GNRs first form DNA-like chains, then develop into monatomic chains by passing through an intermediate configuration in which monatomic chain sections are separated by two-atom attachments. In contrast, zigzag GNRs form rope-ladder-like chains through a process in which the carbon hexagons are first elongated into rectangles; these rectangles eventually coalesce into monatomic chains through a novel triangle-pentagon deformation structure under further tensile deformation. Finally, we show that the width of GNRs plays an important role in the formation of MACCs, and that the ultranarrow GNRs facilitate the formation of full MACCs. The present work should be of considerable interest due to the experimentally demonstrated feasibility of using narrow GNRs to fabricate novel nanoelectronic components based upon monatomic chains of carbon atoms.Comment: 11 pages, 6 figures, Nanotechnology accepted versio

Electrodialytic processes in solid matrices. New insights into batteries recycling. A review.

Electrodialytic Remediation has been widely applied to the recovery of different contaminants from numerous solid matrices solving emerging issues of environmental concern. Results and conclusions reported in studies about real contaminated matrices are summarizes in this work. The influence of the pH value on the treatment effectiveness has been widely proved highlighting the phenomenon “water splitting” in the membrane surface. This dissociation of water molecules is related to the “limiting current” which is desirable to be exceed at the Anion Exchange Membrane in order to produce the entering of protons toward solid matrix. Other important parameters for the optimization of the technique, such as the current density and the liquid to solid ratio, are also discussed through the revision of studies using real solid matrices. This work also focusses on the pioneer proposal of electrokinetic technologies for the recycling of lithium ion batteries considering the relevance of waste properties in the design and optimization of the technique. From a thorough literature revision, it could be concluded that further experimental results are needed to allow an optimal application of the technique to the rising problem of residues from batteries. The main aim of this work is to take the first steps in the recovery of valuable metals from spent batteries, such as Li and Co, incorporating principles of green chemistry.The authors acknowledge the financial support from the “Plan Propio de Investigación de la Universidad de Málaga with Project numbers: PPIT.UMA.B1.2017/20 and PPIT.UMA.B5.2018/17 and the European project THROUGH H2020-MSCA-RISE- 2017-778045. The first author also acknowledge the postdoctoral contract obtained from University of Malaga

The Impact Of Consumer Attitudes About Bioengineering On Purchase Behavior Intentions: Moderating Effects Of Innate Consumer Innovativeness And Anxiety

Biotechnology is anticipated to be the next generation of innovations and is predicted to surpass the IT revolution in terms of economic prosperity (Darby and Zucher, 2003).  But available behavioral and social research relating to biotechnology is at its infant stage.  Most studies are qualitative in nature (i.e., focus groups) and are limited to public policy issues such as awareness, knowledge, and perception of risks (Bredahl, 1999; Frewer et al., 1997; Frewer, Howard, and Shepherd, 1997). According to Bredahl, 2001, few research projects have yet to determine how consumer attitudes can be expected to influence subsequent purchase behavior intentions with genetically modified products. As the U.S. Food and Drug Administration (FDA) continues to approve more and more inventions of biotechnology (i.e., foods such as genetically engineered potatoes and rice; industrial plastic from genetically modified organisms; and life saving pharmaceuticals for diseases such as cancer, HIV, and Alzheimer’s) there is a need for research that investigates how consumer attitudes about genetically modified products influence their purchase intentions and subsequent purchase behavior.  The primary purpose of this research is to investigate how consumer attitudes about bioengineering influence their purchase behavior intentions. Second, the influence of two personal variables innate consumer innovativeness and general anxiety about bioengineering as they relate to purchase behavior intentions will be investigated.  Finally, the study also makes an attempt to determine if the relationship between attitude and behavior intentions is moderated by the two personal variables innate consumer innovativeness and general anxiety about bioengineering.  Personal variables such as these can reasonably be expected to have a differential impact on the relationship between attitude about bioengineering and purchase behavior intentions.  That is, the strength of the relationship between attitude and purchase behavior intentions is likely to be stronger for consumers that are innovative and less anxious about bioengineering than others.  The study results have implications for both researchers and promoters of bioengineering. For researchers, it should be noted that an extensive literature search was unable to find any empirical research to date that have investigated the moderating effects on the relationship between attitude about bioengineering and purchase behavior intentions.  For practitioners, the study will aid biotechnology firms in their efforts in building a more positive attitude about biotechnology in general and to identify the profile of consumers that are more likely to purchase and use products of this technology

Deliberating Public Policy Issues with Adolescents: Classroom Dynamics and Sociocultural Considerations

Classroom discussion and deliberation have been widely touted in the research literature as a centerpiece of high quality civic education. Empirical studies, however, of such processes are relatively few. In a public policy deliberation on immigration conducted in three Midwestern high schools during the academic year 2015–16, the authors found that analysis of a set of deliberations on the subject of immigration policy in the United States reveals the ways in which sociocultural identity aspects of the settings and participants influenced the processes and dynamics of these classroom events. Reflecting upon this analysis suggests a set of factors that reveal the degree to which classroom deliberations are shaped by factors other than rational consideration of the topic