Derivation of the Blackbody Radiation Spectrum from a Natural Maximum-Entropy Principle Involving Casimir Energies and Zero-Point Radiation

By numerical calculation, the Planck spectrum with zero-point radiation is shown to satisfy a natural maximum-entropy principle whereas alternative choices of spectra do not. Specifically, if we consider a set of conducting-walled boxes, each with a partition placed at a different location in the box, so that across the collection of boxes the partitions are uniformly spaced across the volume, then the Planck spectrum correspond to that spectrum of random radiation (having constant energy kT per normal mode at low frequencies and zero-point energy (1/2)hw per normal mode at high frequencies) which gives maximum uniformity across the collection of boxes for the radiation energy per box. The analysis involves Casimir energies and zero-point radiation which do not usually appear in thermodynamic analyses. For simplicity, the analysis is presented for waves in one space dimension.Comment: 11 page

Some Heuristic Semiclassical Derivations of the Planck Length, the Hawking Effect and the Unruh Effect

The formulae for Planck length, Hawking temperature and Unruh-Davies temperature are derived by using only laws of classical physics together with the Heisenberg principle. Besides, it is shown how the Hawking relation can be deduced from the Unruh relation by means of the principle of equivalence; the deep link between Hawking effect and Unruh effect is in this way clarified.Comment: LaTex file, 6 pages, no figure

Generating anisotropic fluids from vacuum Ernst equations

Starting with any stationary axisymmetric vacuum metric, we build anisotropic fluids. With the help of the Ernst method, the basic equations are derived together with the expression for the energy-momentum tensor and with the equation of state compatible with the field equations. The method is presented by using different coordinate systems: the cylindrical coordinates $\rho, z$ and the oblate spheroidal ones. A class of interior solutions matching with stationary axisymmetric asymptotically flat vacuum solutions is found in oblate spheroidal coordinates. The solutions presented satisfy the three energy conditions.Comment: Version published on IJMPD, title changed by the revie

Casimir Energy of a Spherical Shell

The Casimir energy for a conducting spherical shell of radius $a$ is computed using a direct mode summation approach. An essential ingredient is the implementation of a recently proposed method based on Cauchy's theorem for an evaluation of the eigenfrequencies of the system. It is shown, however, that this earlier calculation uses an improper set of modes to describe the waves exterior to the sphere. Upon making the necessary corrections and taking care to ensure that no mathematically ill-defined expressions occur, the technique is shown to leave numerical results unaltered while avoiding a longstanding criticism raised against earlier calculations of the Casimir energy.Comment: LaTeX, 14 pages, 1 figur

Long-term (60-month) results for the implantable miniature telescope: efficacy and safety outcomes stratified by age in patients with end-stage age-related macular degeneration

BACKGROUND: The purpose of this study was to evaluate the long-term results of an implantable miniature telescope (IMT) in patients with bilateral, end-stage, age-related macular degeneration (AMD). METHODS: A prospective, open-label, multicenter clinical trial with fellow eye controls enrolled 217 patients (mean age 76 years) with AMD and moderate-to-profound bilateral central visual acuity loss (20/80-20/800) resulting from untreatable geographic atrophy, disciform scars, or both. A subgroup analysis was performed with stratification for age (patient age 65 to[group 1; n=70] and patient age \u3e/=75 years [group 2; n=127]), with a comparative evaluation of change in best-corrected distance visual acuity (BCDVA), quality of life, ocular complications from surgery, adverse events, and endothelial cell density (ECD). Follow-up in an extension study was 60 months. RESULTS: Data were available for 22, 38, and 31 patients in group 1 and 42, 46, and 32 patients in group 2 at 36, 48, and 60 months, respectively. Mean BCDVA improvement from baseline to 60 months was 2.41+/-2.69 lines in all patients (n=76), with 2.64+/-2.55 lines in group 1 and 2.09+/-2.88 lines in group 2. Quality of life scores were significantly higher in group 1. The most common significant surgery-related ocular complications in group 1 were iritis \u3e30 days after surgery (7/70; 10%) and persistent corneal edema (3/70; 4.3%); and in group 2 were a decrease in BCDVA in the implanted eye or IMT removal (10/127 each; 7.9%), corneal edema \u3e30 days after surgery (9/127; 7.1%), and persistent corneal edema (6/127; 4.7%). Significant adverse events included four corneal transplants, comprising two (2.9%) in group 1 and two (1.6%) in group 2. At 60 months, one patient in group 1 (3.2%) and three patients in group 2 (9.4%) had lost \u3e/=2 lines of vision. The IMT was removed in one (1.4%) and ten (7.9%) patients in group 1 and group 2, respectively. Mean ECD loss was 20% at 3 months. Chronic loss was 3% per year. ECD loss was less in group 1 than in group 2 (35% versus 40%, respectively) at 60 months. CONCLUSION: Long-term results show substantial retention of improvement in BDCVA. Chronic ECD loss was consistent with that reported for conventional intraocular lenses. The IMT performed as well in group 1 (the younger group) as it did in group 2 through month 60. Younger patients retained more vision than their older counterparts and had fewer adverse events. Although not a specified outcome for this study, patients younger than 65 years also fared better than those in group 2 and retained more vision with fewer adverse events through month 60

Casimir interaction between a microscopic dipole oscillator and a macroscopic solenoid

We discuss the interaction between a microscopic electric dipole oscillator and a long solenoid which are separated by a small distance. The solenoid belongs to a simple RLC circuit and the zero point and thermal current fluctuations within the solenoid coils are taken into account. We describe how they affect the equilibrium state and the excited states of the oscillator, thus providing a description of the Casimir interaction of the system. We calculate the modification in the lifetime of the oscillator excited states as a function of the parameters of the circuit, the dipole orientation, and the distance between the dipole and the solenoid. The Casimir force between the solenoid and the electric dipole is calculated, and it is shown that this Casimir interaction always exists, that is, it occurs even when the macroscopic current in the solenoid is zero. We suggest experiments which can exhibit these effects related to the electromagnetic interactions between atoms or molecules and simple circuits

Simulating water table response to proposed changes in surface water management in the C-111 agricultural basin of south Florida

As part of an effort to restore the hydrology of Everglades National Park (ENP), incremental raises in canal stage are proposed along a major canal draining south Florida called C-111, which separates ENP from agricultural lands. The study purpose was to use monitoring and modeling to investigate the effect of the proposed incremental raises in canal stage on water table elevation in agricultural lands. The objectives were to: (1) develop a MODFLOW based model for simulating groundwater flow within the study area, (2) apply the developed model to determine if the proposed changes in canal stage result in significant changes in water table elevation, root zone saturation or groundwater flooding and (3) assess aquifer response to large rainfall events. Results indicate the developed model was able to reproduce measured water table elevation with an average Nash-Sutcliffe > 0.9 and Root Mean Square Error 2 year return period storm), reduced water table intrusion into the root zone. We conclude that the impact of operational changes in canal stage management on root zone saturation and groundwater flooding depended on micro-topography within the field and depth of storm events. The findings of this study can be used in fine tuning canal stage operations to minimize root zone saturation and groundwater flooding of agricultural fields while maximizing environmental benefits through increased water flow in the natural wetland areas. This study also highlights the benefit of detailed field scale simulations

Mechanical and Combustion Performance of Multi-Walled Carbon Nanotubes as an Additive to Paraffin-Based Solid Fuels for Hybrid Rockets

Paraffin-based solid fuels for hybrid rocket motor applications are recognized as a fastburning alternative to other fuel binders such as HTPB, but efforts to further improve the burning rate and mechanical properties of paraffin are still necessary. One approach that is considered in this study is to use multi-walled carbon nanotubes (MWNT) as an additive to paraffin wax. Carbon nanotubes provide increased electrical and thermal conductivity to the solid-fuel grains to which they are added, which can improve the mass burning rate. Furthermore, the addition of ultra-fine aluminum particles to the paraffin/MWNT fuel grains can enhance regression rate of the solid fuel and the density impulse of the hybrid rocket. The multi-walled carbon nanotubes also present the possibility of greatly improving the mechanical properties (e.g., tensile strength) of the paraffin-based solid-fuel grains. For casting these solid-fuel grains, various percentages of MWNT and aluminum particles will be added to the paraffin wax. Previous work has been published about the dispersion and mixing of carbon nanotubes.1 Another manufacturing method has been used for mixing the MWNT with a phenolic resin for ablative applications, and the manufacturing and mixing processes are well-documented in the literature.2 The cost of MWNT is a small fraction of single-walled nanotubes. This is a scale-up advantage as future applications and projects will require low cost additives to maintain cost effectiveness. Testing of the solid-fuel grains will be conducted in several steps. Dog bone samples will be cast and prepared for tensile testing. The fuel samples will also be analyzed using thermogravimetric analysis and a high-resolution scanning electron microscope (SEM). The SEM will allow for examination of the solid fuel grain for uniformity and consistency. The paraffin-based fuel grains will also be tested using two hybrid rocket test motors located at the Pennsylvania State University s High Pressure Combustion Lab

Advances in the proposed electromagnetic zero-point field theory of inertia

A NASA-funded research effort has been underway at the Lockheed Martin Advanced Technology Center in Palo Alto and at California State University in Long Beach to develop and test a recently published theory that Newton's equation of motion can be derived from Maxwell's equations of electrodynamics as applied to the zero-point field (ZPF) of the quantum vacuum. In this ZPF-inertia theory, mass is postulated to be not an intrinsic property of matter but rather a kind of electromagnetic drag force that proves to be acceleration dependent by virtue of the spectral characteristics of the ZPF. The theory proposes that interactions between the ZPF and matter take place at the level of quarks and electrons, hence would account for the mass of a composite neutral particle such as the neutron. An effort to generalize the exploratory study of Haisch, Rueda and Puthoff (1994) into a proper relativistic formulation has been successful. Moreover the principle of equivalence implies that in this view gravitation would also be electromagnetic in origin along the lines proposed by Sakharov (1968). With regard to exotic propulsion we can definitively rule out one speculatively hypothesized mechanism: matter possessing negative inertial mass, a concept originated by Bondi (1957) is shown to be logically impossible. On the other hand, the linked ZPF-inertia and ZPF-gravity concepts open the conceptual possibility of manipulation of inertia and gravitation, since both are postulated to be electromagnetic phenomena. It is hoped that this will someday translate into actual technological potential. A key question is whether the proposed ZPF-matter interactions generating the phenomenon of mass might involve one or more resonances. This is presently under investigation.Comment: Revised version of invited presentation at 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 13-15, 1998, Cleveland, OH, 10 pages, no figure

Assessing the invertebrate fauna trajectories in remediation sites of Winstone Aggregates Hunua quarry in Auckland

This study monitored the invertebrates in restoration plantings in the Winstone Aggregates Hunua Quarry. This was to assess the re-establishment of invertebrates in the restoration planting sites and compare them with unplanted control and mature sites. This study follows on from a baseline study carried out in 2014-2015 measuring the restoration trajectory of invertebrates in the Winstone Aggregate Hunua quarry site. A range of entomological monitoring techniques were used and found that dung beetles, millipedes, foliage moths, leaf litter moths and some mite species increased in numbers from the control sites through to the mature sites, while ants, rove beetles, grass moths, some carabid beetles, and worms showed a downwards trend from the mature sites to the control sites. Further monitoring of invertebrates in the restoration area should be carried out