3,918 research outputs found
Extreme laser pulses for possible development of boron fusion power reactors for clean and lasting energy
Extreme laser pulses driving non-equilibrium processes in high density
plasmas permit an increase of the fusion of hydrogen with the boron isotope 11
by nine orders of magnitude of the energy gains above the classical values.
This is the result of initiating the reaction by non-thermal ultrahigh
acceleration of plasma blocks by the nonlinear (ponderomotive) force of the
laser field, in addition to the avalanche reaction that has now been
experimentally and theoretically manifested. The design of a very compact
fusion power reactor is scheduled to produce then environmentally fully clean
and inexhaustible generation of energy at profitably low costs. The reaction
within a volume of cubic millimetres during a nanosecond can only be used for
controlled power generation.Comment: 10 pages, 5 fugure
Comparative study of platinum electroplating to improve micro gold electrode arrays with LCP laminate
Decoding the cellular network interaction of neurons and glial cells are important in the development of new therapies for diseases of the central nervous system (CNS). Electrophysiological in vivo studies in mice will help to understand the highly complex network. In this paper, the optimization of epidural liquid crystal polymer (LCP) electrodes for different platinum electroplating parameters are presented and compared. Constant current and pulsed current electroplating varied in strength and duration was used to decrease the electrode impedance and to increase the charge storage capacity (CSCC). In best cases, both methods generated similar results with an impedance reduction of about 99%. However, electroplating with pulsed currents was less parameter-dependent than the electroplating with constant current. The use of ultrasound was essential to generate platinum coatings without plating defects. Electrode model parameters extracted from the electrode impedance reflected the increase in surface porosity due to the electroplating processes
P2X1 and P2X5 subunits form the functional P2X receptor in mouse cortical astrocytes
ATP plays an important role in signal transduction between neuronal and glial circuits and within glial networks. Here we describe currents activated by ATP in astrocytes acutely isolated from cortical brain slices by non-enzymatic mechanical dissociation. Brain slices were prepared from transgenic mice that express enhanced green fluorescent protein under the control of the human glial fibrillary acidic protein promoter. Astrocytes were studied by whole-cell voltage clamp. Exogenous ATP evoked inward currents in 75 of 81 astrocytes. In the majority (~65%) of cells, ATP-induced responses comprising a fast and delayed component; in the remaining subpopulation of astrocytes, ATP triggered a smoother response with rapid peak and slowly decaying plateau phase. The fast component of the response was sensitive to low concentrations of ATP (with EC50 of ~40 nM). All ATP-induced currents were blocked by pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS); they were insensitive to ivermectin. Quantitative real-time PCR demonstrated strong expression of P2X1 and P2X5 receptor subunits and some expression of P2X2 subunit mRNAs. The main properties of the ATP-induced response in cortical astrocytes (high sensitivity to ATP, biphasic kinetics, and sensitivity to PPADS) were very similar to those reported for P2X1/5 heteromeric receptors studied previously in heterologous expression systems
Absence of Respect and Recognition of Victims in the Criminal Justice System in Bangladesh
This study explores how the victims of crime are treated in the criminal justice system of Bangladesh. Therefore, this study aims to learn victims’ access to justice, victims’ participation in criminal proceedings, victims’ rights and needs of protection and support services and to identify the ongoing victimization process and capacity gaps existing within the criminal justice system. As a matter of fact, in Bangladesh victims are often found utterly dissatisfied with the treatment of the current justice system as it does not ensure their due respect and recognition. The qualitative techniques are applied in this study. However, the prevailing legal provisions do not manifest victims’ respect and recognition. Supports of the criminal justice system to the victims are quite inadequate compared to the rights of the victims. Indeed, in Bangladesh victims have a limited legal right to access to the court proceedings. But, because of victims’ lack of awareness about those rights, unfair treatment towards them and the absence of the rules of law, victims cannot get full benefits even of those inadequate laws. Thus, victims undergo different challenges in all stages of the justice system which include reporting the case, investigation by the police, giving testimony, trail process, plea bargaining etc. Finally, a victim protection scheme should urgently be developed to provide the victims with a fearless environment for seeking justice, physical security, psychological assistance, reparation and rehabilitation etc, with a view to establishing the rights of the victims
Generalized vortex-model for the inverse cascade of two-dimensional turbulence
We generalize Kirchhoff's point vortex model of two-dimensional fluid motion
to a rotor model which exhibits an inverse cascade by the formation of rotor
clusters. A rotor is composed of two vortices with like-signed circulations
glued together by an overdamped spring. The model is motivated by a treatment
of the vorticity equation representing the vorticity field as a superposition
of vortices with elliptic Gaussian shapes of variable widths, augmented by a
suitable forcing mechanism. The rotor model opens up the way to discuss the
energy transport in the inverse cascade on the basis of dynamical systems
theory.Comment: 14 pages, 21 figure
Ferromagnetic phase transition for the spanning-forest model (q \to 0 limit of the Potts model) in three or more dimensions
We present Monte Carlo simulations of the spanning-forest model (q \to 0
limit of the ferromagnetic Potts model) in spatial dimensions d=3,4,5. We show
that, in contrast to the two-dimensional case, the model has a "ferromagnetic"
second-order phase transition at a finite positive value w_c. We present
numerical estimates of w_c and of the thermal and magnetic critical exponents.
We conjecture that the upper critical dimension is 6.Comment: LaTex2e, 4 pages; includes 6 Postscript figures; Version 2 has
expanded title as published in PR
Theory of impedance networks: The two-point impedance and LC resonances
We present a formulation of the determination of the impedance between any
two nodes in an impedance network. An impedance network is described by its
Laplacian matrix L which has generally complex matrix elements. We show that by
solving the equation L u_a = lambda_a u_a^* with orthonormal vectors u_a, the
effective impedance between nodes p and q of the network is Z = Sum_a [u_{a,p}
- u_{a,q}]^2/lambda_a where the summation is over all lambda_a not identically
equal to zero and u_{a,p} is the p-th component of u_a. For networks consisting
of inductances (L) and capacitances (C), the formulation leads to the
occurrence of resonances at frequencies associated with the vanishing of
lambda_a. This curious result suggests the possibility of practical
applications to resonant circuits. Our formulation is illustrated by explicit
examples.Comment: 21 pages, 3 figures; v4: typesetting corrected; v5: Eq. (63)
correcte
Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor
After the very long consideration of the ideal energy source by fusion of the
protons of light hydrogen with the boron isotope 11 (boron fusion HB11) the
very first two independent measurements of very high reaction gains by lasers
basically opens a fundamental breakthrough. The non-thermal plasma block
ignition with extremely high power laser pulses above petawatt of picosecond
duration in combination with up to ten kilotesla magnetic fields for trapping
has to be combined to use the measured high gains as proof of an avalanche
reaction for an environmentally clean, low cost and lasting energy source as
potential option against global warming. The unique HB11 avalanche reaction is
are now based on elastic collisions of helium nuclei (alpha particles) limited
only to a reactor for controlled fusion energy during a very short time within
a very small volume.Comment: 11 pages, 6 figures, Submitted to Proceedings 2nd Symposium High
Power Laser Science and Engineering, 14-18 MARCH 2016, Suzhou/Chin
Theory of resistor networks: The two-point resistance
The resistance between arbitrary two nodes in a resistor network is obtained
in terms of the eigenvalues and eigenfunctions of the Laplacian matrix
associated with the network. Explicit formulas for two-point resistances are
deduced for regular lattices in one, two, and three dimensions under various
boundary conditions including that of a Moebius strip and a Klein bottle. The
emphasis is on lattices of finite sizes. We also deduce summation and product
identities which can be used to analyze large-size expansions of two-and-higher
dimensional lattices.Comment: 30 pages, 5 figures now included; typos in Example 1 correcte
A promising new device for the prevention of parastomal hernia.
Parastomal hernia (PSH) is the most frequent long-term stoma complication with serious negative effects on quality of life. Surgical revision is often required and has a substantial morbidity and recurrence rate. The development of PSH requires revisional surgery with a substantial perioperative morbidity and high failure rate in the long-term follow-up. Prophylactic parastomal mesh insertion during stoma creation has the potential to reduce the rate of PSH, but carries the risk of early and late mesh-related complications such as infection, fibrosis, mesh shrinkage, and/or bowel erosion. We developed a new stomaplasty ring (KORING), which is easy to implant, avoids potential mesh-related complications, and has a high potential of long-term prevention of PSH. Here we describe the technique and the first use
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