Physics Commons^™

Sum Rule For The Adm Mass And Tensions In Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen

David Kastor

An asymptotically planar AdS spacetimes is characterized by its ADM mass and tensions. We define an additional ADM charge Q associated with the scaling Killing vector of AdS, show that Q is given by a certain sum over the ADM mass and tensions and that Q vanishes on solutions to the Einstein equation with negative cosmological constant. The sum rule for the mass and tensions thus established corresponds in an AdS/CFT context to the vanishing of the trace of the boundary stress tensor. We also show that an analogous sum rule holds for local planar sources of stress-energy sources in …

On The Universality Of Inner Black Hole Mechanics And Higher Curvature Gravity, Alejandra Castro, Nima Dehmami, Gaston Giribet, David Kastor

David Kastor

Black holes are famous for their universal behavior. New thermodynamic relations have been found recently for the product of gravitational entropies over all the horizons of a given stationary black hole. This product has been found to be independent of the mass for all such solutions of Einstein-Maxwell theory in d=4,5. We study the universality of this mass independence by introducing a number of possible higher curvature corrections to the gravitational action. We consider finite temperature black holes with both asymptotically flat and (A)dS boundary conditions. Although we find examples for which mass independence of the horizon entropy product continues …

An Ethnographic Study: Becoming A Physics Expert In A Biophysics Research Group, Idaykis Rodriguez

Idaykis Rodriguez

Expertise in physics has been traditionally studied in cognitive science, where physics expertise is understood through the difference between novice and expert problem solving skills. The cognitive perspective of physics experts only create a partial model of physics expertise and does not take into account the development of physics experts in the natural context of research. This dissertation takes a social and cultural perspective of learning through apprenticeship to model the development of physics expertise of physics graduate students in a research group. I use a qualitative methodological approach of an ethnographic case study to observe and video record the …

Helmholtz And Diffusion Equations Associated With Local Fractional Derivative Operators Involving The Cantorian And Cantor-Type Cylindrical Coordinates, Yang Xiaojun

Xiao-Jun Yang

The main object of this paper is to investigate the Helmholtz and diffusion equations on the Cantor sets involving local fractional derivative operators. The Cantor-type cylindrical-coordinate method is applied to handle the corresponding local fractional differential equations. Two illustrative examples for the Helmholtz and diffusion equations on the Cantor sets are shown by making use of the Cantorian and Cantor-type cylindrical coordinates.

The Collaboration Particle; Applying The Formalism Of Quantum Theory To Cognition., Kelsey E. Landis, Hontas F. Farmer

Hontas F Farmer

We propose that collaboration between two people can be thought of as a quantum cognitive process wherein the relevant reality to be comprehended is an idea being communicated from one person to the other. Through a combination of writing center pedagogy and quantum theory, supported by mathematical evidence, we assert that collaboration can be effectively and equally established in both face-to-face and online writing tutoring sessions through conscious, active meditation to harness what can be thought of as a particle. Included is an analysis of writing center scholarship to show how collaboration is traditionally considered in a writing center context, …

Rayleigh Lidar Temperature Studies In The Upper Mesosphere And Lower Thermosphere, Leda Sox, Vincent B. Wickwar, Josh P. Herron, Matthew T. Emerick

Leda Sox

No abstract provided.

Gravitational Tension And Thermodynamics Of Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen

David Kastor

We derive new thermodynamic relations for asymptotically planar AdS black hole and soliton solutions. In addition to the ADM mass, these spacetimes are characterized by gravitational tensions in each of the planar spatial directions. We show that with planar AdS asymptotics, the sum of the ADM mass and tensions necessarily vanishes, as one would expect from the AdS /CFT correspondence. Each Killing vector of such a spacetime leads to a Smarr formula relating the ADM mass and tensions, the black hole horizon and soliton bubble areas, and a set of thermodynamic volumes that arise due to the non-vanishing cosmological constant. …

Creating Low-Cost ‘Balloonsats’ For Stem Education With 3d Printing, Jeremy Straub

Jeremy Straub

A new technology, known as 3D printing, allows the rapid fabrication of plastic structures of virtually any configuration. These structures are light-weight, durable and inexpensive. This paper considers the utility of utilizing 3D printing to create enclosures for ‘BalloonSats’ – small, low-cost spacecraft analog which can be utilized by students to understand space engineering, conduct near-space science (e.g., physics, biological and other experiments) and touch the edge of space.

The utility of 3D printed structures for use in the near-space low-temperature and low-pressure environment is considered. This analysis falls into four key areas. First, the ability of the structures to …

Thermodynamic Volumes And Isoperimetric Inequalities For De Sitter Black Holes, Brian P. Dolan, David Kastor, David KubiznˇA´K, Robert B. Mann, Jennie Traschen

David Kastor

We consider the thermodynamics of rotating and charged asymptotically de Sitter black holes. Using Hamiltonian perturbation theory techniques, we derive three different first law relations including variations in the cosmological constant, and associated Smarr formulas that are satisfied by such spacetimes. Each first law introduces a different thermodynamic volume conjugate to the cosmological constant. We examine the relation between these thermodynamic volumes and associated geometric volumes in a number of examples, including Kerr-dS black holes in all dimensions and Kerr-Newman-dS black holes in D=4. We also show that the Chong-Cvetic-Lu-Pope solution of D=5 minimal supergravity, analytically continued to positive cosmological …

The International Trafficking In Arms Regulations: Precluding Innovation In Academic Spacecraft Engineering — Or Are They?, Jeremy Straub, Joe Vacek

Jeremy Straub

Government regulations and uncertainty about their enforcement can be a significant barrier to innovation. In business, it is undesirable to consume time and other resources developing a product that cannot be sold or which requires navigating significant bureaucracy for each sale. In academ-ia, where limited funding is available prior to the submission of a grant pro-posal and receipt of an award, proposal-stage compliance costs can derail a project long before it begins. This paper reviews the International Traffick-ing in Arms Regulations (ITAR) and their impact on spacecraft research in academia, private research labs and industry. It reviews the exemptions available, …

Universe Galaxy Contraction, Struck Force Table New Forces, New Universes, New Elements, Sociological Implications, James T. Struck

James T Struck

Universe Galaxy Contraction, Struck Force Table and New Forces, New More Charged Universe and In Between Universe, 12 New Chemical Elements-Universe galaxy contraction is supported by quasar blueshift of some material, Andromeda Galaxy movement towards the Milky Way, blazar movement towards Earth, Earth, galaxy movement towards the Great Attractor, Hydra Centaurus and Shapley Supercluster and some evidence of Virgo Cluster movement at a 250-300 km/s rate. Contraction might be happening at a lesser rate than expansion, but contraction of the Universe and galaxies may effect our Earth before expansion affects us. From a sociological viewpoints, Universe galaxy contraction is something …

Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski

Wojciech Budzianowski

This article provides an analysis of processes for separation CO2 by using carbonic anhydrase enzyme with particular emphasis on reactive-membrane solutions. Three available processes are characterised. Main challenges and prospects are given. It is found that in view of numerous challenges practical applications of these processes will be difficult in near future. Further research is therefore needed for improving existing processes through finding methods for eliminating their main drawbacks such as short lifetime of carbonic anhydrase or low resistance of reactive membrane systems to impurities contained in flue gases from power plants.

Synthesis Of Al2tio5 And Its Effect On The Properties Of Chitosan-Nh4scn Polymer Electrolytes, Siti Rohana Majid, Hassan F., Woo H. J., Aziz N. A., Kufian M. Z.

Siti Rohana Majid

In this paper, Al2TiO5 ceramic material has been synthesised and used as filler in polymer electrolyte system to enhance the conductivity. The precursor sintered at 1,050 A degrees C and contained 0.08 mole of aluminium nitrate gives the best and complete formation of Al2TiO5. Composite polymer electrolytes of chitosan-NH4SCN containing different amount of home-made Al2TiO5 were prepared by solution casting. The addition of filler has enhanced the conductivity of polymer electrolyte. The sample 57 wt% chitosan-38 wt% NH4SCN-5 wt% Al2TiO5 exhibited the highest electrical conductivity of 2.10 x 10(-4) S cm(-1) at room temperature. The presence of the Al2TiO5 creates …

The Effect Of Antimony Trioxide On Poly (Vinyl Alcohol)-Lithium Perchlorate Based Polymer Electrolytes, Siti Rohana Majid, Lim C. S., Ramesh S.

Siti Rohana Majid

A new type of inorganic filler antimony trioxide (Sb2O3) is used to prepare composite polymer electrolytes based on poly (vinyl alcohol) (PVA) and lithium perchlorate (LiClO4) by solution casting technique. The incorporation of Sb2O3 enhances the ionic conductivity at ambient temperature and exhibits the highest ionic conductivity value of 9.51 x 10(-5) S cm(-1) upon the addition of 6 wt% Sb2O3. Thermogravimetric analyses (TGA) reveal that the second weight loss is reduced. This shows the improvement in thermal stability of electrolyte film upon addition of Sb2O3. Differential scanning calorimetry (DSC) analyses show that the glass transition temperature (T-g) value decreases …

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …