Preprint
|
|
|
Physical Sciences, Other; diabetes mellitus; blood glucose; kidney; diabetic neuropathy; pancreas
Online: 22 October 2018 (12:45:08 CEST)
|
|
Share this article with
×
This present study was designed to find out whether the acankoreagenin showed the antidiabetic and renoprotective effects in streptozotocin (STZ)-induced diabetic nephropathy (DN) rats. Type I diabetes was induced by a single intraperitoneal injection of STZ (70 mg/kg). At the end of the experiment, rats were euthanized and serum/plasma was separated for the determination of glucose, insulin, glycated hemoglobin A1c (HbA1c), C-peptide, biochemical parameters, and kidney function. One kidney was used for determining glutathione, superoxide dismutas, malondialdehyde, and tumor necrosis factor-alpha levels. The other kidney and pancreas were used for histopathological studies and immunohistochemical measurement of transforming growth factor beta (TGF-β) or NF-κB. Acankoreagenin (2 mg/kg) treatments led to a significant reduction in blood glucose assessed via oral glucose tolerance test (OGTT) in diabetic rats at 2 h. The treatment also resulted in improved body weight, decreased HbA1c, restored lipid profile, and renal oxidative stress. By inhibiting NF-κB, the release of proinflammatory cytokines was suppressed and by inhibiting TGF-β, the renal fibrosis was suppressed in STZ-induced diabetic rat model. Histopathological injury was also observed in pancreatic and renal tissues. These findings support the beneficial effect of acankoreagenin treatment in DN, which could be attributed to its antidiabetic and renoprotective effects.
Preprint
|
|
|
Physical Sciences, Other; ultra-weak photon emission; age; temporal variation; asymmetry; analytical model; photon diffusion
Online: 19 October 2018 (18:40:31 CEST)
|
|
Share this article with
×
Ultra-weak photon emissions (UPEs) including those from human have been experimented for decades. The photo-genic origin of UPE has also been attributed to the oxidative stress or free radical production that is unique to metabolically active states of biological organisms. However, there are considerable gaps in quantitative understanding of UPE. In this work, I propose an analytical framework of hypothesis for the initial objective of modeling a few superficial presentations of UPE of human, including the systematic dependency on age, the diurnal variation, and the geometric asymmetry associated with serious asymmetrical pathological conditions. The hypothesis which is currently limited to human assumes a new form of energy state, termed vivo-nergy, which resides only in metabolically active organisms that are also under neuronal control. The hypothesis projects a decrease of the vivo-nergy in human during growth beyond puberty, with the rate of decrease dictated by a critical time-scale---the age of the first opposite-sex sexual intercourse (FOSSI). The hypothesis also proposes a modification of the vivo-nergy by the phases of systematic or homeostatic physiology. The hypothesis further postulates that the deviation of the physiology-modified vivo-nergy from the pre-puberty level is deteriorated by acquired organ-specific pathological conditions. Any reduction of vivo-nergy from the pre-puberty level is hypothesized to proportionally cause oxidative stress that functions as the physical source of UPE. The resulted steady-state diffusion of the photon emitted from a photo-genic source of UPE in a human geometry simplified as a homogeneous spherical domain is modeled by photon diffusion principles incorporating an extrapolated zero-boundary condition. The age and systematic physiology combined determines the intensity of the centered physiological photo-genic source. The acquired (single) pathology sets both the intensity and the off-center position of the (single) pathological photo-genic source. When the age-related, physiology-commanded, and pathology-controlled modifications of the photo-genetic sources are implemented in the photon diffusion model, the photon fluence rate at the surface of the simplified human-representing spherical domain reveals the dependency on age, the temporal variation corresponding to systematic physiology, and the geometric asymmetry associated with significant asymmetric pathological condition as reported previously for UPE. The hypothesis, as it provides analytical conveniences for quantitative estimation of UPE patterns, may be useful to further model-based interpretation of the spatial-temporal characteristics of UPE.
Preprint
|
|
|
Physical Sciences, Other; electron paramagnetic resonance; EPR; multi-frequency EPR; high-spin cobalt complex; resolution of A-mid
Online: 16 October 2018 (10:04:16 CEST)
|
|
Share this article with
×
Low-frequency electron paramagnetic resonance (EPR) is used to extract the EPR parameter A-mid and support the approximate X-band value of g-mid for Ba(CoyZn1/3-yTa2/3)O3. Although cobalt hyperfine structure for the [+/−1/2> state is often unresolved at X-band or S-band, it is resolved in measurements on this compound. This allows for detailed analysis of the molecular orbital for the [+/−1/2> state, which is often the ground state. Moreover, this work shows that the EPR parameters for Co substituted into Zn compounds gives important insight into the properties of zinc binding sites.
Preprint
|
|
|
Physical Sciences, Other; thermodynamics; entropy; artificial intelligence; differential geometry; computational physics
Online: 10 October 2018 (07:19:04 CEST)
|
|
Share this article with
×
Because only two variables are needed to characterize a simple thermodynamic system in equilibrium, any such system is constrained on a 2D manifold. Of particular interest are the exact 1-forms on the cotangent space of that manifold, since the integral of exact 1-forms is path-independent, a crucial property satisfied by state variables such as internal energy dE and entropy dS. Our prior work [1] shows that given an appropriate language of vector calculus, a machine can re-discover the Maxwell equations and the incompressible Navier-Stokes equations from data. In this paper, We enhance this language by including differential forms and show that machines can re-discover the equation for entropy dS given data. Since entropy appears in various fields of science in different guises, a potential extension of this work is to use the machinery developed in this paper to let machines discover the expressions for entropy from data in fields other than classical thermodynamics.
Preprint
|
|
|
Physical Sciences, Other; Cosmic-rays; Citizien Science; Extensive air showers
Online: 8 October 2018 (17:45:43 CEST)
|
|
Share this article with
×
The Cosmic-Ray Extremely Distributed Observatory (CREDO) is a project dedicated to global studies of extremely extended cosmic-ray phenomena, the cosmic-ray ensembles (CRE), beyond the capabilities of existing detectors and observatories. Up to date cosmic-ray research has been focused on detecting single air showers, while the search for ensembles of cosmic-rays, which may overspread a significant fraction of the Earth, is a scientific terra incognita. Instead of developing and commissioning a completely new global detector infrastructure, CREDO proposes approaching the global cosmic-ray analysis objectives with all types of available detectors, from professional to pocket size, merged into a worldwide network. With such a network it is possible to search for evidences of correlated cosmic-ray ensembles. One of the observables that can be investigated in CREDO is a number of spatially isolated events collected in a small time window which could shed light on fundamental physics issues. The CREDO mission and strategy requires active engagement of a large number of participants, also non-experts, who will contribute to the project by using common electronic devices (e.g. smartphones). In this note the status and perspectives of the project is presented.
Preprint
|
|
|
Physical Sciences, Other; standard interpretation; Bohmian mechanics; quantum uncertainty; determinism; subject-object relations; systems theory
Online: 20 September 2018 (07:40:07 CEST)
|
|
Share this article with
×
For more than eighty years the standard interpretation (SI) has dominated quantum physics. Perspectives that have tried to challenge this domination have been remarkably unsuccessful. As a result, quantum theory (QT) has remained remarkably stagnant. The article offers a critical examination of SI and provides an explanation for its continued domination. It also uses Bohmian mechanics—a theoretical perspective advanced by American physicist David Bohm—as a case study for why alternative interpretations have failed to displace SI. The article sees the main reason for the failure to achieve much progress beyond SI in the unresolved philosophical problem of subject-object relation that continues to plague our study of physics. The article sketches a path to a possible solution and outlines a new science practice that this solution will require.
Preprint
|
|
|
Physical Sciences, Other; Entanglement; EPR Paradox; ER = EPR conjecture; GR = QM; Locality; Theory of Everything; Quantum Communications
Online: 12 September 2018 (15:38:14 CEST)
|
|
Share this article with
×
During the last century, entanglement was the bone of contention between the two main pillars of Physics: General Relativity (GR) and Quantum Mechanics (QM). This began in 1935 with the Einstein-Podolsky-Rosen paradox (EPR paradox) which concluded that although Quantum Mechanics is not wrong, it is an incomplete theory to represent physical reality. In this paper it is demonstrated that some byproducts resulting from entanglement and which we will call avatars act as a hinge that link both theories making the completeness of QM clear. Moreover, a thorough analysis of the non-locality of this effect will be carried out. Besides, it is demonstrated that entanglement is an instantaneous phenomenon and that it does not require the use of a superluminal signaling for this purpose. Finally, the avatars will also appear in each wormhole resulting from an entanglement process (WREP) demonstrating that they are traversable with an equivalent path of null length which can be crossed in a null time with all that this implies in Quantum Communications.
Preprint
|
|
|
Physical Sciences, Other; entanglement; quantum computation; quantum communication
Online: 5 September 2018 (05:56:20 CEST)
|
|
Share this article with
×
In this paper, I propose new models of quantum information processing using the exchange interaction in physical systems. The partial SWAP operator that can be realized using the exchange interaction is used as the underlying resource for defining models of quantum computation, quantum communication, quantum memory and decoherence-free subspaces. Given the non-commutativity of these operators (for adjacent operators operating on a common qubit), a number of quantum states and entanglement patters can be obtained. This zoo of states can be classified, due to the parity constraints and permutation symmetry of the states, into invariant subspaces that are used for the definition of some of the applications in this paper.
Preprint
|
|
|
Physical Sciences, Other; landuse change; climate change; garden city model; green vegetation; Landsat; urban heat island
Online: 4 September 2018 (08:28:33 CEST)
|
|
Share this article with
×
The key anthropogenic effects on climate include the changes in land use and emission of greenhouse gases into the atmosphere. Depletion of vegetation poses serious threat that speeds the process of climate change and reduces carbon sequestration by the environment. Thus, the preservation of natural environment in urban areas is an essential component of the garden city model, proposed by Sir Ebenezer Howard in 1898, to ensure ecological balance. Recent Landsat images showed that Kumasi does not have the required percentage of green vegetation as was stipulated in the garden city model on which the city was built. It was observed that most parts of Kumasi's green vegetation have been lost to built environments. This study was conducted to assess the impact of urbanization on the garden city status and its effect on the micro-climate of the city. Significant changes in the vegetation cover of the city was evaluated from Landsat-TM imagery and analysis of a long term climatic data of Kumasi carried out over a 55-year period (1960 to 2015). It was observed that, climatic conditions have slightly changed, as mean surface temperature of has increased by 1.2 °C/ 55 years, due to the significant landuse changes from development of non-transpiring, reduced evaporative urban surfaces. However, the impact is not greatly felt due to the geographical location of the city on the globe despite the evidence of a considerable temperature change. Green vegetation conservation for the city is recommended as a top priority in future for city authorities and planners.
Preprint
|
|
|
Physical Sciences, Other; spectroscopy; plasma diagnostics
Online: 29 August 2018 (08:16:51 CEST)
|
|
Share this article with
×
We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate Te along a chord by measuring the ratio of the C_III 97.7 nm to CIV 155 nm line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of Te. The aim of these studies is to increase the Taylor state lifetime, primarily by increasing the electron temperature. Also, a model is proposed to predict magnetic lifetime of relaxed states and is found of predict the lifetime satisfactorily. Furthermore, we find that proton cooling can be explained by equilibration with the electrons.
Preprint
|
|
|
Physical Sciences, Other; chromatic polynomial; chromatically equivalent; chromatically unique; necklace graph
Online: 17 August 2018 (13:24:33 CEST)
|
|
Share this article with
×
For a graph G, let P(G, λ) be its chromatic polynomial. Two graphs G and H are said to be chromatically equivalent if P(G,λ) = P(H,λ). A graph is said to be chromatically unique if no other graph shares its chromatic polynomial. In this paper, chromatic polynomial of the necklace graph Nn, for n ≥ 2 has been determined. It is further shown that N3 is chromatically unique.
Preprint
|
|
|
Physical Sciences, Other; time irreversibility; permutation entropy; visibility graphs; efficient market hypothesis
Online: 4 August 2018 (13:16:26 CEST)
|
|
Share this article with
×
Time irreversibility, i.e. the lack of invariance of the statistical properties of a system under time reversal, is a fundamental property of all systems operating out of equilibrium. Time reversal symmetry is associated with important statistical and physical properties and is related to the predictability of the system generating the time series. Over the past fifteen years, various methods to quantify time irreversibility in time series have been proposed, but these can be computationally expensive. Here we propose a new method, based on permutation entropy, which is essentially parameter-free, temporally local, yields straightforward statistical tests, and has fast convergence properties. We apply this method to the study of financial time series, showing that stocks and indices present a rich irreversibility dynamics. We illustrate the comparative methodological advantages of our method with respect to a recently proposed method based on visibility graphs, and discuss the implications of our results for financial data analysis and interpretation.
Preprint
|
|
|
Physical Sciences, Other; technology-product network; maximum entropy; bipartite networks; bipartite configuration model; exponential random graphs; diffusion on networks; innovation system; economic fitness and complexity
Online: 4 August 2018 (12:54:53 CEST)
|
|
Share this article with
×
In this work we identify combinations of technological activities that signal the presence local capabilities in a country to successfully export a product. We use country-level patent and trade data to generate a multi-layer network, and we apply maximization of entropy to generate synthetic data to effectively divide signal from noise. We show that in several sectors the signal far exceed the noise. Our exercise provides robust evidence of the presence of synergies between technologies to explain trade performances in specific markets. This can be highly useful for policy makers, to inform industrial and innovation policies.
Preprint
|
|
|
Physical Sciences, Other; membranes; vesicles; lipids; proteins; mesophase separation; domains; lipid rafts; clusters
Online: 25 July 2018 (17:50:38 CEST)
|
|
Share this article with
×
Cell plasma membranes display a dramatically rich structural complexity characterized by functional sub-wavelength domains with specific lipid and protein composition. Under favorable experimental conditions, patterned morphologies can also be observed in vitro on model systems such as supported membranes or lipid vesicles. Lipid mixtures separating in liquid-ordered and liquid-disordered phases below a demixing temperature play a pivotal role in this context. Protein-protein and protein-lipid interactions also contribute to membrane shaping by promoting small domains or clusters. Such phase separations displaying characteristic length-scales falling in-between the nanoscopic, molecular scale on the one hand and the macroscopic scale on the other hand, are named mesophases in soft condensed matter physics. In this Review, we propose a classification of the diverse mechanisms leading to mesophase separation in biomembranes. We distinguish between mechanisms relying upon equilibrium thermodynamics and those involving out-of-equilibrium mechanisms, notably active membrane recycling. In equilibrium, we show that the mechanisms generically dwell on an up-down symmetry breaking between the upper and lower bilayer leaflets. Symmetry breaking is an ubiquitous mechanism in condensed matter physics at the heart of several important phenomena. In the present case, it can be either spontaneous (domain buckling) or explicit, i.e. due to an external cause (global or local vesicle bending properties). Whenever possible, theoretical predictions and simulation results are confronted to experiments on model systems or living cells, which enables us to identify the most realistic mechanisms from a biological perspective.
Preprint
|
|
|
Physical Sciences, Other; Quantum Entanglement, Separability, Positive Partial Transpose Criterion, Permutation, Quantum Information, Quantum Computing, Quantum Communication, Quantum Non-locality, Quantum Correlations, SWAP Operator
Online: 25 July 2018 (14:20:21 CEST)
|
|
Share this article with
×
In this paper, the connections between quantum non-locality and permutation symmetries are
explored. This includes two types of symmetries: permutation across a superposition and permutation
of qubits in a quantum system. An algorithm is proposed for nding the separability class of
a quantum state using a method based on factorizing an arbitrary multipartite state into possible
partitions, cyclically permuting qubits of the vectors in a superposition to check which separability
class it falls into and thereafter using a reduced density-matrix analysis of the system is proposed.
For the case of mixed quantum states, conditions for separability are found in terms of the partial
transposition of the density matrices of the quantum system. One of these conditions turns out to
be the Partial Positive Transpose (PPT) condition. A graphical method for analyzing separability
is also proposed. The concept of permutation of qubits is shown to be useful in de ning a new
entanglement measure in the `engle'.
Preprint
|
|
|
Physical Sciences, Other; Anomalous diffusion; FRAP; Numerical Simulations; PH -domain, Membrane Binding
Online: 19 July 2018 (13:17:03 CEST)
|
|
Share this article with
×
FRAP technique have been used for decades to measure movements of molecules in 2D. Data obtained by FRAP experiments in cell plasma membranes are assumed to be described through means of two parameters, a diffusion coefficient D (as defined in a pure Brownian model) and a mobile fraction M. Nevertheless, it has also been shown that recoveries can be nicely fit using anomalous sub-diffusion. FRAP at variable radii has been developed using the Brownian diffusion model to access geometrical characteristics of the surrounding landscape of the molecule. Here we performed numerical simulations of continuous time random walk (CTRW) anomalous subdiffusion and interpreted them in the context of variable radii FRAP. These simulations were compared to experimental data obtained at variable radii on living cells using the PH domain of the membrane binding protein EFA6 (exchange factor for ARF6, a small G protein). This protein domain is an excellent candidate to explore the structure of the interface between cytosol and plasma membrane in cells. By direct comparison of our numerical simulations to the experiments, we show that this protein does not exhibit anomalous diffusion in BHK cells. The non Brownian PH-EFA6 dynamics observed here is more related to spatial heterogeneities such as cytoskeleton fences effects.
Preprint
|
|
|
Physical Sciences, Other; quantum information; quantum dynamics; entanglement
Online: 4 June 2018 (13:03:21 CEST)
|
|
Share this article with
×
Quantum Computation, in the gate array version, uses logical gates adopting convenient forms for computational algorithms based on those of classical computation. There, two-level quantum systems are the basic elements connecting the binary nature of classical computation with the settlement of quantum processing. Despite, their design depends on specific quantum systems and physical interactions involved, exacerbating the dynamics analysis. Predictable and controllable manipulation should be addressed to control the quantum states, but resources are restricted to limitations imposed by the physical settlement. This work presents a formalism to decompose the quantum information dynamics in SU(22d) for 2d-partite two-level systems into 22d-1 SU(2) quantum subsystems. Decomposition lets to set control procedures, to generate large entangled states and to design specialized dedicated quantum gates. There, easy and traditional operations proposed by quantum computation are recovered for more complex and large systems. Alternating the parameters of local and non-local interactions, the procedure states a universal exchange semantics on the generalized Bell states basis. It could be understood as a momentary splitting of the 2d information channels into 22d-1 pairs of 2 level quantum information subsystems and a settlement of the quantum information manipulation free of the imposed restrictions by the underlying physical system.
Preprint
|
|
|
Physical Sciences, Other; magneto-optics; magnetic thin films; optical constants
Online: 3 May 2018 (10:59:50 CEST)
|
|
Share this article with
×
This work is devoted to physical vapor deposition synthesis, and characterisation of bismuth and lutetium-substituted ferrite-garnet thin-film materials for magneto-optic (MO) applications. The properties of garnet thin films sputtered using a target of nominal composition type Bi0.9Lu1.85Y0.25Fe4.0Ga1O12 are studied. By measuring the optical transmission spectra at room temperature, the optical constants and the accurate film thicknesses can be evaluated using Swanepoel’s envelope method. The refractive index data are found to be matching very closely to these derived from Cauchy’s dispersion formula for the entire spectral range between 300-2500 nm. The optical absorption coefficient and the extinction coefficient data are studied for both the as-deposited and annealed garnet thin-film samples. A new approach is applied for accurately deriving the optical constants data simultaneously with the physical layer thickness, using a combination approach employing custom-built spectrum-fitting software in conjunction with Swanepoel’s envelope method. MO properties, such as specific Faraday rotation, MO figure of merit and MO swing factor are also investigated for several annealed garnet-phase films.
Preprint
|
|
|
Physical Sciences, Other; aptamer; aptasensor; electrical properties; networks; proteotronics
Online: 16 March 2018 (12:12:17 CET)
|
|
Share this article with
×
Selected by in vitro techniques (SELEX, cell-SELEX), aptamers are strands of DNA or RNA molecules able to bind a wide range of targets, from small molecules to live cells, and even tissues, with high affinity and specificity. Due to their efficient targeting ability, aptamers are extensively used in different fields of applications. For example, they ensure high performance as cancer-related markers or in recognizing cancer cells. Actually, they represent a promising way for early diagnosis (biosensors) and to deliver imaging agents and drugs, in both cancer imaging and therapy (therapeutic aptamers). Aptamer-based biosensors (aptasensors) have attracted particular attention over the last decades, so as the possibility of using aptamers in disease therapy in substitution of monoclonal antibodies. The paper briefly reviews the most recent literature on this topic, both concerning the advances in biomedical applications and in the development of electrical aptasensors. The investigation concerning the bioelectronics features of aptamers, to be implemented in the development of electrical nanobiosensors, is also reviewed. To this aim, some recent results of a theoretical/computational framework for modelling the electrical properties of biomolecules (Proteotronics) are reported.
Preprint
|
|
|
Physical Sciences, Other; abduction; recursion; physical law; Hume’s problem
Online: 11 February 2018 (05:35:28 CET)
|
|
Share this article with
×
The paper studies some cases in physics such as Galilean inertia motion and etc., and presents a logical schema of recursive abduction, from which we can derive the universality of physical laws in an effective logical path without requiring infinite inductions. Recursive abduction provides an effective logical framework to connect a universal physical law with finite empirical observations based on both quasi-law tautologies and suitable recursive dimensions, two new concepts introduced in this paper. Under the viewpoint of recursive abduction, the historical difficulty from Hume’s problem naturally vanishes. In Hume’s problem one always misunderstood a time-recursive issue as an infinitely inductive problem and, thus, sank into an inescapable quagmire. With this new effective logical schema, the paper gives a concluding discussion to Hume’s problem and justifies the validity of probability argument for natural laws.
Preprint
|
|
|
Physical Sciences, Other; Quantum mechanics; superposition; collapse; bio-psychology; observation, mental representation; reality; potentiality; infinity; nothingness;
Online: 8 February 2018 (15:56:38 CET)
|
|
|
Share this article with
×
When phenomena in quantum mechanics are interpreted from the perspective of bio-psychology, wave function collapse from several to a single eigenstate must be plausibly explained. Quantum mechanics requires a context, yet the context of an observer is rarely considered. On the other hand, in bio-psychology, the observer context is examined to explain superposition and collapse by different mental functions used in everyday life. Three mental functions are described, one of which is responsible for observation, and the others for conservation and treatment of information in mental representation. Whereas observation produces information with certainty, the subsequent processes result in uncertain potentiality. In order to encompass uncertainty, multiple possibilities are simultaneously considered in mental superposition, one of which should represent the unknown future outcome. During observation, all suggested potentialities necessarily collapse to one real outcome. The collapse of superposition does not occur in observable physical reality, but in its mental representation. Some physical principles—such as superposition, infinity and nothingness before the Big Bang—are pure phenomena of mental representation, which will always remain unverifiable by observation. This argument proves that mental representation brought about by the observer context participates in the production of mental models for the best approximation of physical reality.
Preprint
|
|
|
Physical Sciences, Other; magnetic nanoparticles; ion channels; viscoelastic effects and anomalous diffusion; non-exponential statistics; influence of weak magnetic fields on living systems
Online: 26 January 2018 (06:11:59 CET)
|
|
Share this article with
×
Magnetic nanoparticles are met across many biological species ranging from magnetosensitive bacteria, fishes, bees, bats, rats, birds, to humans. They can be both of biogenetic origin and due to environmental contamination, being either in paramagnetic or ferromagnetic state. The energy of such naturally occurring single-domain magnetic nanoparticles can reach up to 10-20 room kBT in the magnetic field of the Earth, which naturally led to supposition that they can serve as sensory elements in various animals. This work explores within a stochastic modeling framework a fascinating hypothesis of magnetosensitive ion channels with magnetic nanoparticles serving as sensory elements, especially, how realistic it is given a highly dissipative viscoelastic interior of living cells and typical sizes of nanoparticles possibly involved.
Preprint
|
|
|
Physical Sciences, Other; complexity; disequilibrium; equilibrium; individual information; informational entropy
Online: 11 January 2018 (06:31:00 CET)
|
|
Share this article with
×
This work is a generalization of the Lopez-Ruiz, Mancini and Calbet (LMC); and Shiner, Davison and Landsberg (SDL) complexity measures, considering that the state of a system or process is represented by a dynamical variable during a certain time interval. As the two complexity measures are based on the calculation of informational entropy, an equivalent information source is defined and, as time passes, the individual information associated to the measured parameter is the seed to calculate instantaneous LMC and SDL measures. To show how the methodology works, an example with economic data is presented.
Preprint
|
|
|
Melanie J. Loveridge,
Guillaume Remy,
Nadia Kourra,
Ronny Genieser,
Anup Barai,
Mike J. Lain,
Yue Guo,
Mark Amor-Segan,
Mark A. Williams,
Tazdin Amieszajew,
Mark Ellis,
Rohit Bhagat,
David Greenwood
Physical Sciences, Other; Samsung Note 7 Li-ion, Thermal runaway, Ceramic coating, battery, Tomographic image, Welding characterisation
Online: 21 December 2017 (18:32:42 CET)
|
|
Share this article with
×
Li-ion cell designs, component integrity and manufacturing processes all have critical influence on the safety of Li-ion batteries. Any internal defective features that induce a short circuit, can trigger a thermal runaway: a cascade of reactions, leading to a device fire. As consumer device manufacturers push aggressively for increased battery energy, instances of field failure are increasingly reported. Notably Samsung made a press release in 2017 following a total product recall of their Galaxy Note 7 mobile phone, confirming speculation that the events were attributable to the battery and its mode of manufacture. Recent incidences of battery swelling on the new iPhone 8 have been reported in the media, and the techniques and lessons reported herein may have future relevance. Here we look deeper into the key components of one of these cells and confirm evidence of cracking of electrode material in tightly folded areas, combined with a delamination of surface coating on the separator, which itself is an unusually thin monolayer. We report microstructural information about the electrodes, battery welding attributes and thermal mapping of the battery whilst operational. The findings point to the most likely combination of events and highlights the impact of design features, whilst providing structural considerations most likely to have led to the reported incidences relating to this phone.
Preprint
|
|
|
Physical Sciences, Other; oil and gas production; atmospheric emissions; greenhouse gases; gas flaring; H2S
Online: 26 November 2017 (13:21:40 CET)
|
|
Share this article with
×
This paper addresses the atmospheric emissions from oil and gas extraction and production in Greece. The study was carried out in 2014 in the Kavala gulf, which currently is the only location of oil and gas production in Greece and where the exploration activities for hydrocarbons started in the late ‘60’s. This study presents the qualitative and quantitative characteristics of atmospheric emissions, in relation also to the emissions’ control management system. Particular reference is made to sulphur compounds since the existence of volcanic rocks results to increased amounts of H2S. The results shows that, currently, atmospheric emissions of pollutants during extraction and production of hydrocarbons in Greece are very low and do not have any significant effect on air quality and climate change. Since it is expected that exploitation of hydrocarbons and oil and gas extraction and production will increase in the future, appropriate measures should be taken to ensure environmental protection, such as the development of integrated monitoring systems and the use of up to date emission control technologies.
Preprint
|
|
|
Physical Sciences, Other; information entropy production; Discrete Markov Chains; spike train statistics; Gibbs measures; maximum entropy principle
Online: 8 November 2017 (05:25:12 CET)
|
|
Share this article with
×
Experimental recordings of the collective activity of interacting spiking neurons exhibit random behavior and memory effects, thus the stochastic process modeling the spiking activity is expected to show some degree of time irreversibility. We use the thermodynamic formalism to build a framework, in the context of spike train statistics, to quantify the degree of irreversibility of any parametric maximum entropy measure under arbitrary constraints, and provide an explicit formula for the information entropy production of the inferred Markov maximum entropy process. We provide examples to illustrate our results and discuss the importance of time irreversibility for modeling the spike train statistics.
Preprint
|
|
|
Physical Sciences, Other; nonequilibrium thermodynamics; landscape-flux decomposition; mutual information rate; entropy production rate
Online: 11 October 2017 (04:45:05 CEST)
|
|
Share this article with
×
We explore the dynamics of information systems. We show that the driving force for information dynamics is determined by both the information landscape and information flux which determines the equilibrium time reversible and the nonequilibrium time-irreversible behaviours of the system respectively. We further demonstrate that the mutual information rate between the two subsystems can be decomposed into the time-reversible and time-irreversible parts respectively, analogous to the information landscape-flux decomposition for dynamics. Finally, we uncover the intimate relation between the nonequilibrium thermodynamics in terms of the entropy production rates and the time-irreversible part of the mutual information rate. We demonstrate the above features by the dynamics of a bivariate Markov chain.
Preprint
|
|
|
Physical Sciences, Other; IBM quantum experience; no-hiding theorem; quantum information
Online: 27 September 2017 (14:22:55 CEST)
|
|
Share this article with
×
In this note, we demonstrate the quantum no-hiding theorem of Braunstein and Pati [Phys. Rev. Lett. 98, 080502 (2007)] using the IBM 5Q quantum processor. We also analyze the circuit using the ZX calculus of Coecke and Duncan [New J Phys. 13(4), 043016 (2011)], which provides a pictorial/category-theoretic demonstration of the no-hiding theorem.
Preprint
|
|
|
Physical Sciences, Other; watershed; water quality; economics
Online: 23 September 2017 (13:05:13 CEST)
|
|
Share this article with
×
The Delaware River has made a marked recovery in the half-century since the adoption of the Delaware River Basin Commission (DRBC) Compact in 1961 and passage of the Federal Clean Water Act amendments during the 1970s. During the 1960s, the DRBC set a 3.5 mg/l dissolved oxygen criteria for the river based on an economic analysis that concluded a waste load abatement program designed to meet fishable water quality goals would generate significant recreation and environmental benefits. Scientists with the Delaware Estuary Program have recently called for raising the 1960s DO criteria along the Delaware River from 3.5 mg/l to 5.0 mg/l to protect anadromous American shad and Atlantic sturgeon and address the prospect of rising temperatures, sea levels, and salinity in the estuary. This research concludes through a marginal abatement cost (MAC) analysis that it would be cost effective to raise DO levels to meet a more stringent standard by prioritizing agricultural conservation and wastewater treatment investments in the Delaware River watershed to reduce 90% of the pollutant load 13.6 million kg/year of nitrogen (30 million lb/year) for $160 million at 35% of the $449 million annual cost. The annual least cost to reduce nitrogen loads and raise dissolved oxygen levels to meet more stringent water quality standards in the Delaware River totals $45 million for atmospheric NOX reduction, $130 million for wastewater treatment, $132 million for agriculture conservation, and $141 million for urban stormwater retrofitting. This 21st century least cost analysis estimates that $50 million/year is needed to reduce pollutant loads in the Delaware River to raise dissolved oxygen levels to 4.0 mg/l, $150 million/year is needed to reach 4.5 mg/l, and $449 million/year is needed to reach 5.0 mg/l.
Preprint
|
|
|
Physical Sciences, Other; Hengduan Mountains; dendrochronology; climatic response; redundancy analysis
Online: 20 September 2017 (14:21:06 CEST)
|
|
Share this article with
×
Improved understanding of climate-growth relationships of multi-species is fundamental to understand and predict response of forest growth to future climate change. Forests are mainly composed of conifers in Northwestern Yunnan Plateau, but variations of growth response to climates among the species are not well understood. To detect growth response of multiple species to climate change, we developed residual chronologies of four major conifers, i.e. Abies georgei, Picea likiangensis, Pinus densata and Larix potaninii at upper distributional limits in Shika Snow Mountain. By using dendroclimatology method, we analyzed correlations between the residual chronologies and climate variables. The results showed that conifer radial growth was influenced by both temperature and precipitation in Shika Snow Mountain. Previous November temperature, previous July mean maximum temperature (Tmax) and current June precipitation were the common climatic factors, which had consistent influences on radial growth of four species. Temperature in previous post growing season (September–October) and current growing season (June-August), and precipitation in previous August were the common climatic factors, which had divergent impacts on four species radial growth. Current May Tmax and early growing season (April-May) precipitation showed positive and negative influences on growth of P. likiangensis, respectively. Temperature in current post growing season positively affected growth of A. georgei. According to the prediction of climate models and our understanding in growth response of four species to climate variables, we may understand growth response to climate change at species level. It is difficult to predict future forest growth in the study area, since future climate change might cause both increases or decreases for four species and indirect effects of climate change on forest should be considered.
Preprint
|
|
|
Physical Sciences, Other; field emission; integrated; vacuum microelectronic; cathode tips array; interface ASIC
Online: 23 May 2017 (11:26:38 CEST)
|
|
Share this article with
×
In this paper, a novel integrated high precision vacuum microelectronic accelerometer is put forward based on the theory of field emission, the accelerometer consists of sensitive structure and interface ASIC. The sensitive structure has a mass of a cathode cone tips array, a folded beam, an emitter electrode and a feedback electrode. The sensor is fabricated on a double side polished (1 0 0) N-type silicon wafer, the tips array of cathode are shaped by wet etching with HNA (HNO3, HF and CH3COOH) and metalized by TiW/Au thin film. The structure of sensor is released by ICP process finally. The interface ASIC was designed and fabricated based on the P-JFET high voltage bipolar process. The accelerometer is tested through static field rollover test, and the test results show the integrated vacuum microelectronic accelerometer has good performances, which sensitivity is 3.081V/g and non-linearity is 0.84% in the measuring range of −1g~1g.
Preprint
|
|
|
Physical Sciences, Other; quantum mechanics; the measurement problem; collapse models; X-rays
Online: 1 May 2017 (13:02:50 CEST)
|
|
Share this article with
×
In this paper new upper limits on the parameters of the Continuous Spontaneous Localization (CSL) collapse model are extracted. To this end the X-ray emission data collected by the IGEX collaboration are analyzed and compared with the spectrum of the spontaneous photon emission process predicted by collapse models. This study allows to obtain the most stringent limits within a relevant range of the CSL model parameters, with respect to any other method. The collapse rate $\lambda$ and the correlation length $r_C$ are mapped, thus allowing to exclude a broad range of the parameter space.
Preprint
|
|
|
Physical Sciences, Other; entropy; natural time; complexity measures; seismic electric signals; Olami–Feder–Christensen model; electrocardiograms; El Nino/La Nina Southern Oscillation
Online: 17 April 2017 (12:26:18 CEST)
|
|
Share this article with
×
Natural time is a new time domain introduced in 2001. The analysis of time series associated with a complex system in natural time may provide useful information and may reveal properties that are usually hidden when studying the system in conventional time. In this new time domain, an entropy has been defined and complexity measures based on this entropy as well as its value under time-reversal have been introduced and found applications in various complex systems. Here, we review these applications in the electric signals that precede rupture, e.g., earthquakes, in the analysis of electrocardiograms, as well as in global atmospheric phenomena like the El Nino/La Nina Southern Oscillation.
Preprint
|
|
|
Physical Sciences, Other; infrared remote sensing; volcanoes; earth observation, satellites
Online: 5 October 2016 (13:54:54 CEST)
|
|
Share this article with
×
Volcanic activity essentially consists of the transfer of heat from the Earth’ interior to the surface. The precise signature of this heat transfer relates directly to the processes underway at and within a particular volcano and this can be observed, at a safe distance, remotely, using infrared sensors that are present on Earth-orbiting satellites. For over 50 years, scientists have perfected this art using sensors intended for other purposes, and they are now in a position to determine the particular sort of activity that characterizes different volcanoes. This review will describe the theoretical basis of the discipline and then discuss the sensors available for the task and the history of their use. Challenges and opportunities for future development in the discipline are then discussed.
Preprint
|
|
|
Physical Sciences, Other; 3-D fluid-electrostatic coupling field; electrical sensor performance; concentration measurement; gas/solid two-phase flow
Online: 31 August 2016 (11:03:30 CEST)
|
|
Share this article with
×
This paper proposed three-dimensional numerical simulation method by coupling of electrostatic and fluid fields to evaluating the performance of electrical sensor in the concentration measurement of gas/solid two-phase flow. Compared with the static numerical simulation, this real-time dynamic 3-D simulation method can research on a designed capacitance sensor combining the dynamic characteristics of the two-phase flows for concentration measurement. Several fluid-electrostatic models of transmission pipes with different sensor structures are built. Under different test positions and different particle concentrations, the flow characteristics and the corresponding electric signals can be obtained, and the correlation coefficient between the concentration values and the capacitance values are used for performance evaluation of the sensors. The effects of flow regimes on concentration measurement are also been investigated in this paper. To validate the results of simulation, an experimental platform with horizontal straight pipe for phase volume concentration measurement of solid/air two-phase flow is built, and the experimental results agree well with simulation conclusions. The simulation and test results show that the coupling models can give constructive reference opinions for the sensor design and collection of installation position in different transmission pipelines, which are very important for the practical process of pneumatic conveying system.
Preprint
|
|
|
Physical Sciences, Other; hitting; ultrasonography; lateral dominance; abdominal muscle; back muscle
Online: 8 August 2016 (16:36:41 CEST)
|
|
Share this article with
×
The purpose of the present study was to examine the relationships between bat swing speed (BSS) and muscle thickness and lateral asymmetry of the trunk and limbs in collegiate baseball players. Twenty-four collegiate baseball players participated in this study. The maximum BSS in hitting a teed ball was measured using a motion capture system. The muscle thicknesses of the trunk (upper abdominal rectus, central abdominal rectus, lower abdominal rectus, abdominal wall, and multifidus lumborum), upper limb, and lower limb were measured using a B-mode ultrasonography. Lateral asymmetry between each pair of muscles was determined as the ratio of the thickness of the dominant side to that of the non-dominant side. Significant positive correlations were observed between BSS and muscle thicknesses of the abdominal wall and multifidus lumborum on the dominant side (r = 0.426 and 0.431, respectively; p < 0.05), while nearly significant positive correlations were observed between BSS and muscle thicknesses on the non-dominant side. No significant correlations were found between BSS and lateral asymmetry of all muscles. These findings indicate the importance of the trunk muscles for bat swing, and the lack of association between BSS and lateral asymmetry of muscle size.
Preprint
|
|
|
Physical Sciences, Other; imide, DFT, HOMO, spontaneous, endothermic
Online: 11 May 2016 (09:42:45 CEST)
|
|
Share this article with
×
Based on DFT (density functional theory) using B3LYP/6-31G method, theoretical investigations applied to demonstrate the structural, electronic properties and stability of (N,Nˊ-(1,4-phenylene)bis(1,8-naphthalimide)) is more stable than the compound (N-(4-amino phenyl)1,8-naphthalimide) by (-1.2762 eV or -29.4299 Kcal.mol-1) depending on the values of HOMO, synthesis reaction of imide is spontaneous and endothermic at temperature 275˚C according to the values of ∆rS, ∆rG and ∆rH.