Metallic Ferromagnetism in the 3D Hubbard Model at Finite Temperature

Andr´e Neves Ribeiro,Claudio Andrade Macedo 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.10

The goal of this work is to examine the possibility of ferromagnetism in a three-dimensional lattice using the Hubbard model with only nearest-neighbor hopping and finite on-site Coulomb interaction (U) and temperature (T) when solved using the dynamical mean-field approximation (DMFA). We calculated the density of states for an fcc lattice with n = 0.6, 0.7 and 0.8, at T = 0.04 t/kB, and with U = 3W where W denotes the non-interacting energy bandwidth. The results reveal magnetization that is nearly saturated and indicate that these systems are metallic. In the particular case where n = 0.6, the magnetization, internal energy and specific-heat versus temperature curves were calculated.

Ion beam analysis of sputtered AlN films

Arshad Mahmood,E. Andrade,S. Muhl,A. Shah,M. Khizar,M. Yasin Akhtar Raja 한국물리학회 2011 Current Applied Physics Vol.11 No.2

Polycrystalline aluminium nitride (AlN) films have been prepared by DC reactive magnetron sputtering followed by its characterization using advance electronic and optical techniques. Film quality has been optimized mainly using deposition parameters. Rutherford backscattering spectroscopy (RBS) and nuclear interaction (NR) techniques were used to analyze the film density (atoms/cm^3), elemental composition and impurities of the grown film. Our ion beam analysis (IBA) was based on the particle energy spectra bombarded with a low-energy deuterium beam. The corresponding linear thickness of the film was measured using a profilometer. X-Ray diffraction, spectroscopic ellipsometry and atomic force microscope have also been employed to reinforce the results. We found that highly dense and stoichiometric films can be obtained at higher plasma current. Under optimal deposition conditions, the film densities of ∼2.45 g/cm^3, FWHM ∼0.125 and the surface roughness ∼6.758 nm have been achieved successfully.

Alternative Nanostructures for Thermophones

Aliev, Ali E.,Mayo, Nathanael K.,Jung de Andrade, Monica,Robles, Raquel O.,Fang, Shaoli,Baughman, Ray H.,Zhang, Mei,Chen, Yongsheng,Lee, Jae Ah,Kim, Seon Jeong American Chemical Society 2015 ACS NANO Vol.9 No.5

<P>Thermophones are highly promising for applications such as high-power SONAR arrays, flexible loudspeakers, and noise cancellation devices. So far, freestanding carbon nanotube aerogel sheets provide the most attractive performance as a thermoacoustic heat source. However, the limited accessibility of large-size freestanding carbon nanotube aerogel sheets and other even more exotic materials recently investigated hampers the field. We describe alternative materials for a thermoacoustic heat source with high-energy conversion efficiency, additional functionalities, environmentally friendly, and cost-effective production technologies. We discuss the thermoacoustic performance of alternative nanostructured materials and compare their spectral and power dependencies of sound pressure in air. We demonstrate that the heat capacity of aerogel-like nanostructures can be extracted by a thorough analysis of the sound pressure spectra. The study presented here focuses on engineering thermal gradients in the vicinity of nanostructures and subsequent heat dissipation processes from the interior of encapsulated thermoacoustic projectors. Applications of thermoacoustic projectors for high-power SONAR arrays, sound cancellation, and optimal thermal design, regarding enhanced energy conversion efficiency, are discussed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-5/nn507117a/production/images/medium/nn-2014-07117a_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn507117a'>ACS Electronic Supporting Info</A></P>

Worm-Like Superparamagnetic Nanoparticle Clusters for Enhanced Adhesion and Magnetic Resonance Relaxivity

Smith, Cartney E.,Lee, JuYeon,Seo, Yongbeom,Clay, Nicholas,Park, Jooyeon,Shkumatov, Artem,Ernenwein, Dawn,Lai, Mei-Hsiu,Misra, Sanjay,Sing, Charles E.,Andrade, Brenda,Zimmerman, Steven C.,Kong, Hyunjo American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.2

<P>Nanosized bioprobes that can highlight diseased tissue can be powerful diagnostic tools. However, a major unmet need is a tool with adequate adhesive properties and contrast-to-dose ratio. To this end, this study demonstrates that targeted superparamagnetic nanoprobes engineered to present a worm-like shape and hydrophilic packaging enhance both adhesion efficiency to target substrates and magnetic resonance (MR) sensitivity. These nanoprobes were prepared by the controlled self-assembly of superparamagnetic iron oxide nanoparticles (SPIONs) into worm-like superstructures using glycogen-like amphiphilic hyperbranched polyglycerols functionalized with peptides capable of binding to defective vasculature. The resulting worm-like SPION clusters presented binding affinity to the target substrate 10-fold higher than that of spherical ones and T<SUB>2</SUB> molar MR relaxivity 3.5-fold higher than that of conventional, single SPIONs. The design principles discovered for these nanoprobes should be applicable to a range of other diseases where improved diagnostics are needed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2017/aamick.2017.9.issue-2/acsami.6b10891/production/images/medium/am-2016-10891p_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am6b10891'>ACS Electronic Supporting Info</A></P>

Presidential Public Diplomacy 2.0: Seven Lessons to Prevent Fire in Cyberspace

dos Santos, Niedja de Andrade e Silva Forte The Korean Association for Public Diplomacy 2021 Journal of public diplomacy Vol.1 No.1

The Amazon fires in summer 2019 triggered an incendiary Twitter debate between French president Emmanuel Macron and Brazilian president Jair Bolsonaro that engaged political leaders, celebrities, and audiences worldwide. Currently, diplomats-in-chief connect to the global public through completely open debates, often without proper advice from foreign-affairs ministers, which may result in misunderstandings and conflicts among world leaders. Hence, this study argues that these interactions must be supported by Nicholas Cull's seven lessons in public diplomacy. The main topic on hand is presidential public diplomacy performed through digital means in cyberspace. Thus, after distinguishing cyberspace, digital diplomacy, and cyberdiplomacy, the literature review focuses on presidential public diplomacy, presidential diplomacy on Twitter, and Cull's seven lessons. Subsequently, the case study method provides a snapshot of the debate between Macron and Bolsonaro over the Amazon fires. This study concludes by answering the research question and indicating grist for the mill with regard to future developments.

Original Article : The effect of coenzyme Q10 on endothelial function in a young population

( Jerrold Petrofsky ),( M. Laymon ),( H. Lee ),( E. Hernandez ),( D. Dequine ),( L. Thorsen ),( R. Lovell ),( J. Andrade ) 물리치료재활과학회 2012 Physical therapy rehabilitation science Vol.1 No.1

Objective: Coenzyme (CoQ10) is an enzymatic co factor used in normal cellular metabolism. Recent evidence shows that in people with heart disease it can reverse endothelial cell damage in the blood vessels. It is also a potent antioxidant. Design: One group pretest-posttest design. Methods: In the present study, endothelial function was evaluated using the response to occlusion and heat before and 2 weeks after administration of CoQ10, 300 mg/day. Thirty Eight subjects, who are physical therapy students, participated in a series of experiments to see if taking 300 mg of CoQ10 daily for 2 weeks would impact resting blood flow in the forearm skin and the blood flow response to 4 minutes of vascular occlusion and the response to local heat (42˚C) for 6 minutes. Results: The results showed that, for this population, there was no difference in the response to heat. However, the response to occlusion was improved after administration of CoQ10. Conclusions: It would appear that in a young population CoQ10 has no effect on the nitric oxide vasodilator pathway in skin but does influence other vasodilator pathways.

Burnout and Long-term Sickness Absence From the Teaching Function: A Cohort Study

Salvagioni, Denise A.J.,Mesas, Arthur E.,Melanda, Francine N.,Gonzalez, Alberto D.,de Andrade, Selma M. Occupational Safety and Health Research Institute 2022 Safety and health at work Vol.13 No.2

Background: The present objective was to verify whether burnout (emotional exhaustion [EE], depersonalization [DP] and low professional efficacy [PE]) is a risk factor for long-term sickness absence (LTSA; 30 consecutive days) from the teaching role. Methods: This was a prospective cohort study with two years of follow-up that investigated 509 elementary and high-school teachers. Burnout was identified by Maslach Burnout Inventory. Poisson regression with robust variance was used to adjust for possible confounders. Results: The incidence of LTSA was 9.4%. High EE levels were associated with LTSA in the crude analysis, but the association lost statistical significance after adjustments (for sex, age, perception of work-life balance, general self-rated health, chronic pain and depression). High DP levels were associated with this outcome, even after all adjustments (relative risk = 1.80; 95% confidence interval: 1.05-3.09). Low PE levels were not related to LTSA. Conclusion: The results reinforce the need to improve teachers' work conditions to reduce burnout, particularly DP, and its consequences.

The effect of coenzyme Q10 on endothelial function in a young population

Petrofsky, Jerrold,Laymon, M.,Lee, H.,Hernandez, E.,Dequine, D.,Thorsen, L.,Lovell, R.,Andrade, J. korean Academy of Physical Therapy Rehabilitation 2012 Physical therapy rehabilitation science Vol.1 No.1

Objective: Coenzyme (CoQ10) is an enzymatic co factor used in normal cellular metabolism. Recent evidence shows that in people with heart disease it can reverse endothelial cell damage in the blood vessels. It is also a potent antioxidant. Design: One group pretest-posttest design. Methods: In the present study, endothelial function was evaluated using the response to occlusion and heat before and 2 weeks after administration of CoQ10, 300 mg/day. Thirty Eight subjects, who are physical therapy students, participated in a series of experiments to see if taking 300 mg of CoQ10 daily for 2 weeks would impact resting blood flow in the forearm skin and the blood flow response to 4 minutes of vascular occlusion and the response to local heat ($42^{\circ}C$) for 6 minutes. Results: The results showed that, for this population, there was no difference in the response to heat. However, the response to occlusion was improved after administration of CoQ10. Conclusions: It would appear that in a young population CoQ10 has no effect on the nitric oxide vasodilator pathway in skin but does influence other vasodilator pathways.

Water Vapor Sorption of Stereoregular Poly(2-Hydroxyethyl Methacrylat)and Poly(2,3-Dihydroxypropyl Methacrylate)

Y . K . Sung(성용길),M . S . Jhon(전무식),D . E . Gregonis,J . D . Andrade 한국고분자학회 1984 폴리머 Vol.8 No.2

The Effect of Auricular and Systemic Acupuncture on the Electromyographic Activity of the Trapezius Muscle with Trigger Points—A Pilot Study

Patrı´cia Silva de Camargo,Carla Rigo Lima,Maria Luiza de Andrade E Rezende,Adriana Teresa Silva Santos,Joa˜o Wagner Rodrigues Hernandez,Andre´ia Maria Silva 사단법인약침학회 2018 Journal of Acupuncture & Meridian Studies Vol.11 No.1

The purpose of this study was to analyze and compare intra and intergroup the immediate effect of the auricular and LR8 systemic acupuncture on the electromyographic activity of the trapezius with the trigger points. This is an experimental clinical trial; 40 people were split in 4 distinct groups (n = 10): GI mustard seed application in the auricular acupoint; GII bilateral needle application in the LR8 acupoint; GIII combination of the techniques; GIV/Control Group mustard seed application in an acupoint not linked to the muscle tension. The EMG was used to assess the muscle contraction for 5 seconds during the resting time and during the isometric contraction time. The EMG signal was first collect without the acupuncture intervention; then both techniques were applied for 5 minutes; and the EMG was collected again right after these applications. The Shapiro-Wilk test was used, the t test was paired with the Wilcoxon test to the intragroup comparison; One-way analysis of variance test for intergroup comparison. There was no statistical difference in the intragroup comparison for the groups. The same happened to the intergroup comparison before and after application. Systemic and auricular acupuncture did not promote immediate changes in the EMG activity of the trapezius muscle in individuals with MTrPs.