scholarly journals A preliminary note on branched α-ray tracks

1921 ◽  
Vol 99 (700) ◽  
pp. 432-435 ◽  
Keyword(s):  
Present Note ◽  
Nuclear Collision ◽  
Preliminary Note ◽  
Reasonable Time ◽  
Preceding Article ◽  
Order Of Magnitude ◽  
Pass Through ◽  
The One ◽  
Reciprocating Expansion ◽  
Α Particles

According to Prof. Sir E. Rutherford, if about one hundred thousand α-rays from radium C pass through the air, on the average there will be one close nuclear collision, which produces a swiftly moving atom. Thus, if we take a great number of photographs of α-ray tracks compatible with the above order of magnitude, we might expect to find some evidence to indicate the disruption of atoms by the α-particles. The present note is to describe some preliminary trials in this direction. The reciprocating expansion apparatus of the preceding article is very convenient for taking a large number of photographs within a reasonable time. Direct eye-observation confirmed the existence of some branched tracks which differed greatly in configuration from spurred tracks like the one photographed by Mr. C. T. R. Wilson. Arrangements were then made to devise a suitable method of photographing such tracks and to show their orientation in space.

Theoretical studies on the one- and two-photon absorption of tetrabenzoporphyrins and phthalocyanines

2004 ◽  
Vol 82 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Xin Zhou ◽  
Ai-Min Ren ◽  
Ji-Kang Feng ◽  
Xiao-Juan Liu
Keyword(s):  
Dipole Moment ◽  
Cross Sections ◽  
Density Functional ◽  
Transition Dipole Moment ◽  
Photon Absorption ◽  
Transition Dipole ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Order Of Magnitude ◽  
The One

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 10–50 – 345.9 × 10–50 cm4·s·photon–1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.

scholarly journals Plane thermonuclear detonation waves initiated by proton beams and quasi-one-dimensional model of fast ignition

2014 ◽  
Vol 33 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Alexander A. Charakhch'yan ◽  
Konstantin V. Khishchenko
Keyword(s):  
Detonation Wave ◽  
Fusion Reaction ◽  
Plasma Heating ◽  
Symmetry Plane ◽  
Detonation Waves ◽  
Proton Beams ◽  
One Dimensional ◽  
Wide Range ◽  
The One ◽  
Α Particles

AbstractThe one-dimensional problem on bilatiral irradiation by proton beams of the plane layer of condensed DT mixture with length 2H and density ρ0 ≤ 100ρs, where ρs is the fuel solid-state density at atmospheric pressure and temperature of 4 K, is considered. The proton kinetic energy is 1 MeV, the beam intensity is 1019 W/cm2 and duration is 50 ps. A mathematical model is based on the one-fluid two-temperature hydrodynamics with a wide-range equation of state of the fuel, electron and ion heat conduction, DT fusion reaction kinetics, self-radiation of plasma and plasma heating by α-particles. If the ignition occurs, a plane detonation wave, which is adjacent to the front of the rarefaction wave, appears. Upon reflection of this detonation wave from the symmetry plane, the flow with the linear velocity profile along the spatial variable x and with a weak dependence of the thermodynamic functions of x occurs. An appropriate solution of the equations of hydrodynamics is found analytically up to an arbitrary constant, which can be chosen so that the analytical solution describes with good accuracy the numerical one. The gain with respect to the energy of neutrons G ≈ 200 at Hρ0 ≈ 1 g/cm2, and G > 2000 at Hρ0 ≈ 5 g/cm2. To evaluate the ignition energy Eig of cylindrical targets, the quasi-1D model, limiting trajectories of α-particles by a cylinder of a given radius, is suggested. The model reproduces the known theoretical dependence Eig ~ ρ0−2 and gives Eig = 160 kJ for ρ0 = 100ρs ≈ 22 g/cm3.

scholarly journals A Note on the Construction of a Set of Fundamental Circuits on a Surface of Genus p

1961 ◽  
Vol 4 (1) ◽  
pp. 13-21
Author(s):  
R. G. de Buda
Keyword(s):  
Single Point ◽  
Orientable Surface ◽  
Flat Region ◽  
Pass Through ◽  
The One

On an orientable surface of genus p, a set of 2p fundamental circuits can be selected which all pass through a single point A. After cutting along the 2p circuits, the surface can be unfolded into a flat region bounded by a 4p-gon so that: the set of vertices corresponds to the one point A; and the 2p pairs of edges to the 2p fundamental circuits; and the interior of the polygon to the remainder of the surface. If the edges of the polygon are directed, the 2 edges which correspond to one fundamental circuit will be directed in opposite sense, since the surface is orientable [1]. The sequence and direction of the edges is the same as the sequence of the fundamental circuits.

scholarly journals Health care logistics: mapping and optimization of patients logistics

2021 ◽  
Vol 12 (8) ◽  
pp. 2161-2179
Author(s):  
Daiane Maria de Genaro Chiroli ◽  
Raíza Conde Coradazi ◽  
Fabio Jose Ceron Branco ◽  
Yslene Rocha Kachba ◽  
Franciely Velozo Aragão ◽  
...  
Keyword(s):  
Linear Programming ◽  
Computational Simulation ◽  
Transportation Of Patients ◽  
Patient Transport ◽  
Specific Approach ◽  
Health Region ◽  
The Third ◽  
City Hall ◽  
Pass Through ◽  
The One

Healthcare logistics play an important role in management, being attributed the activities of acquisition, distribution and movement of materials, professionals and patients. This work aims to develop a study, using the healthcare logistics in the movement of patients in the third health region of Paraná, proposing a linear programming problem that will pass through a computational simulation, considering the existing demands and constraints in the system, aiming to optimize the flow of patients from this region. The present study developed four mathematical models, based on demands and constraints followed by linear programming in order to find the best possible solution for the flow of patients from the third health region of the state of Paraná. The study developed reached its goal of optimization, generating an economy in the transportation of patients. Through the analysis of the results, it is concluded that the model that best suits the presented problem is the one of costs minimization, since the one of vehicles presented higher costs. Possibly the model that minimizes the vehicles would bring better results if the vehicles were not outsourced, but of the Ponta Grossa City Hall (PMPG). Was possible to verify the importance of the theme, especially when referring to the flow of patients in the health services due to the lack of studies with this specific approach. Even with the scarcity of data, it is possible to notice the potential for improvements on this patient transport system.

scholarly journals Role of Groundwater-Borne Geogenic Phosphorus for the Internal P Release in Shallow Lakes

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1783 ◽  
Author(s):  
Catharina S. Nisbeth ◽  
Søren Jessen ◽  
Ole Bennike ◽  
Jacob Kidmose ◽  
Kasper Reitzel
Keyword(s):  
Lake Sediment ◽  
Trophic State ◽  
Driving Factor ◽  
Original Source ◽  
Depth Profiles ◽  
P Release ◽  
Order Of Magnitude ◽  
The One ◽  
Total P

This study explores the under-investigated issue of groundwater-borne geogenic phosphorus (P) as the potential driving factor behind accumulation of P in lake sediment. The annual internally released P load from the sediment of the shallow, hypereutrophic and groundwater-fed lake, Nørresø, Denmark, was quantified based on total P (TP) depth profiles. By comparing this load with previously determined external P loadings entering the lake throughout the year 2016–2017, it was evident that internal P release was the immediate controller of the trophic state of the lake. Nevertheless, by extrapolating back through the Holocene, assuming a groundwater P load corresponding to the one found at present time, the total groundwater P input to the lake was found to be in the same order of magnitude as the total deposit P in the lake sediment. This suggests that groundwater-transported P was the original source of the now internally cycled P. For many lakes, internal P cycling is the immediate controller of their trophic state. Yet, this does not take away the importance of the external and possibly geogenic origin of the P accumulating in lake sediments, and subsequently being released to the water column.

SOLITON INTERACTIONS FOR THE GENERALIZED (3+1)-DIMENSIONAL BOUSSINESQ EQUATION

2012 ◽  
Vol 26 (07) ◽  
pp. 1250062 ◽  
Author(s):  
XIAO-LING GAI ◽  
YI-TIAN GAO ◽  
XIN YU ◽  
ZHI-YUAN SUN
Keyword(s):  
Soliton Solution ◽  
Boussinesq Equation ◽  
Soliton Solutions ◽  
Analytic Solutions ◽  
Propagation Process ◽  
Soliton Propagation ◽  
Soliton Interactions ◽  
Pass Through ◽  
The Moment ◽  
The One

Generalized (3+1)-dimensional Boussinesq equation is investigated in this paper. Through the dependent variable transformation and symbolic computation, the one- and two-soliton solutions are obtained. With the one-soliton solution, the coefficient effects in the soliton propagation process are investigated. Through analyzing the two-soliton solution, two kinds of two-soliton interactions are presented: (i) Two solitons merge into a bigger one whose amplitude increases but does not exceed the sum of the two at the moment of the collision; (ii) Two solitons can pass through each other, and their shapes keep unchanged with a phase shift after the separation. In addition, two kinds of analytic solutions are discussed: (i) "Amplitudes" of the two analytic solutions immediately turn to negative (positive) infinity after the "collision"; (ii) Two analytic solutions are fused into a higher peak (valley) at the moment of "collision", whose "amplitudes" change to negative (positive) infinity after the separation.

scholarly journals The scattering of α-particles by matter

1910 ◽  
Vol 83 (565) ◽  
pp. 492-504 ◽  
Keyword(s):  
Quantitative Measurement ◽  
Direct Evidence ◽  
Zinc Sulphide ◽  
The Other ◽  
Narrow Slit ◽  
Preliminary Note ◽  
Metal Foils ◽  
Strong Source ◽  
Α Particles

In a preliminary note (‘Roy. Soc. Proc.’ A, vol. 81, p. 174, 1908) on the above subject, experiments were described which gave direct evidence of the scattering of the α -particles. In those experiments a strong source of α -radiation was placed at one end of a long exhausted tube, and the α -particles, after passing through a narrow slit, fell upon a zinc sulphide screen sealed to the other end of the tube. When the pressure inside the tube was very low, the narrow line of scintillations which marked the place of incidence of the α -particles on the screen was well defined, but when the rays on their way to the screen passed through gas or through thin metal foils the edges of this line of scintillations became indistinct. The amount of scattering could be estimated for different foils by placing them in the path of the rays and noting the distribution of the scintillations on the screen. The present investigation was undertaken with a view to obtain a quantitative measurement of the scattering by determining the most probable angle through which an α -particle of definite range is turned by passing through a given thickness of matter. The following are the chief points investigated:— (1) Determination of the amount of scattering produced in different thicknesses of the same material. (2) Comparison of the amounts of scattering produced in different materials. (3) Relation between the velocity of the α -particles and the amount of their scattering.

COMPUTING WITH MEMBRANES (P SYSTEMS): A VARIANT

2000 ◽  
Vol 11 (01) ◽  
pp. 167-181 ◽  
Author(s):  
GHEORGHE PĂUN
Keyword(s):  
Membrane Computing ◽  
P Systems ◽  
Open Problems ◽  
Recursively Enumerable ◽  
Pass Through ◽  
The One ◽  
Priority Relation ◽  
Recursively Enumerable Languages ◽  
Biochemical Features ◽  
Computing Models

Membrane Computing is a recently introduced area of Molecular Computing, where a computation takes place in a membrane structure where multisets of objects evolve according to given rules (they can also pass through membranes). The obtained computing models were called P systems. In basic variants of P systems, the use of objects evolution rules is regulated by a given priority relation; moreover, each membrane has a label and one can send objects to precise membranes, identified by their labels. We propose here a variant where we get rid of both there rather artificial (non-biochemical) features. Instead, we add to membranes and to objects an "electrical charge" and the objects are passed through membranes according to their charge. We prove that such systems are able to characterize the one-letter recursively enumerable languages (equivalently, the recursively enumerable sets of natural numbers), providing that an extra feature is considered: the membranes can be made thicker or thinner (also dissolved) and the communication through a membrane is possible only when its thickness is equal to 1. Several open problems are formulated.

Notes on Ptolemy

1952 ◽  
Vol 14 (1) ◽  
pp. 78-86
Author(s):  
J. Ph. Vogel
Keyword(s):  
Present Note ◽  
The Other ◽  
Trade Routes ◽  
Guiding Principle ◽  
Saint Martin ◽  
The One

It has been recognized long ago that Ptolemy's topography of Cis-Gangetic India was based on trade-routes. Nearly a century ago Vivien de Saint Martin spoke of “the almost exclusive employment of itineraries of merchants and caravans indicating on each route the series of daily stations”. We may compare the lists of stations inserted in books on India of the seventeenth and eighteenth centuries. One of the earliest examples we find in Joannes de Laet's little volume De Imperio Magni Mogolis (Leiden, 1631), p. 57. The author evidently derived his lists from the itineraries of the English merchants Richard Steel and John Crowther. The French jeweller and traveller Jean-Baptiste Tavernier has included full lists of stations along the principal trade-routes in his Indian Travels (ch. iv–xii). In the first place he deals with the two routes from Surat to Agra, all-important to European traders, the one by the Tāptī valley and Mālwā, the other by way of Aḥmadābād and Rājpūtānā. If we keep in mind that Ptolemy must have used similar lists, it will go far to explain the disconcerting fact that so many among the localities in his tables are not known from indigenous sources, either literary or epigraphical, whereas famous towns have been omitted. His tables are fundamentally lists of stages, and this must be our guiding principle in unravelling the riddle of Ptolemy's topography. The present note is an attempt to demonstrate this in some detail.

scholarly journals A novel method of ESR oscillating magnetization value determination in strongly correlated metals

2018 ◽  
Vol 185 ◽  
pp. 02003 ◽  
Author(s):  
Marat Gilmanov ◽  
Alexey Semeno ◽  
Alexander Samarin ◽  
Sergey Demishev
Keyword(s):  
Resonance Field ◽  
Simple Expression ◽  
60 Ghz ◽  
Strongly Correlated ◽  
Static Magnetization ◽  
Spin Resonance ◽  
Order Of Magnitude ◽  
Novel Method ◽  
Value Determination ◽  
The One

We propose a powerful method of direct measurement of oscillating magnetization by the electron spin resonance, based on dependence of resonant conditions on geometry of the experiment. Theoretical consideration of the matter leads to a simple expression for oscillating magnetization. Approbation of this method is implemented by means of cavity ESR spectrometer (60 GHz) on two diverse metallic systems, where static magnetization at the resonance field varies by an order of magnitude. Quantitative values of oscillating magnetization (905 G for EuB6 at T = 4.2 K and 94 G for CeB6 at T = 1.8 K) are in appropriate agreement with the one obtained by the other methods.

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