Application of Autoradiography for the Study of Penetration of Aggressive Liquids into Plastics under the Stress

Aggressive liquids are often stored and transported in plastic vessel, tanks or tubes in chemical industry. Such plastic material is exposed to both mechanical and chemical stress. This stress causes penetration of liquids into plastics. Penetration of some liquids was studied by means of autoradiography. A special device was developed for the study of penetration of aggressive liquids into plastics under stress. This device and results of measurements of such penetration are described. It is shown that penetration occurs through microsplits in the studied system.

Aggressive Flüssigkeiten werden häufig in Behältern, Tanks oder Röhren aus plasten gelagert oder transportiert. Solche Plastwerkstoffe unterliegen dabei sowohl mechanischen als auch chemischen Angriffen, die ein Durchdringen der Flüssigkeiten verursachen können. Die Durchdringung einiger solcher Flüssigkeiten wurde mittels Autoradiographie untersucht. Dazu wurde eine besondere Anordnung entwickelt, um solche Eindringvorgänge von aggressiven Flüssigkeiten unlersuchen zu können. Sowohl die Versuchsanordnung als auch einige Meβergebnisse werden beschrieben. So wurde festgestellt, daβ die Durchdringung in den untersuchten Systemen in Mikrospalten vor sich geht.     

On Quantitative Autoradiography of Semiconductor Basic Material

It will be described methods of the quantitative evaluation of elements interesting in semiconductor technology and their distribution in silicon using autoradiographic techniques. The local concentration of the element phosphorus in dependence of their local distribution is determined with silver halide films. As standard samples silicon disks phosphorus diffused are used.

The distribution of the element boron and their local concentration is determined on the way of neutron induced autoradiography (NIAR). In this technique boron implanted or diffused silicon disks are used as standard samples. Different possibilities of the quantitative evaluation of autoradiograms will be considered and compared.     

Autoradiography of Light Elements in Austenite Steels tested in Liquid Metals

The multielement autoradiography has been used to investigate the redistribution of boron, carbon, oxygen, sodium and phosphorus in an austenitic chromium-nickel steel exposed to a flow of sodium. Under all experimental conditions, the steel samples became impoverished with respect to boron, carbon and phosphorus and this phenomenon became more pronounced with the increases in both the temperature from 923 to 1073 K and the time of the experiment from 500 to 8000 h. The sodium and oxygen penetration of the steel was intercrystalline by character, oxygen being approximately 10 μm ahead of sodium. The redistribution of boron and carbon in the steel samples with and without boron has been investigated after the exposure to lithium and data of the steel penetration by lithium have been obtained. Lithium penetration followed the grain boundaries of steel.     

Determination of Boron Diffusion Profiles by Statistical Autoradiography Spectrometry

Profiles of boron in a planar thyristor structure have been measured by thermal neutron activation and solid state nuclear track detector were utilized for registration of the nuclear reaction products. The maximum sensitivity for boron in the studies case was 10¹⁵ atoms · cm^?3. The developed method can be used for the nondestructive determination of dope profiles for ion-implanted structures.     

How people react to a deadline: time distribution of conference registrations and fee payments

In this paper we present two simple mathematical models to describe human behavior in reaction to deadlines. When a real commitment (e.g. money) is involved, as in the case of a payment deadline, the expected reaction is to postpone it as close as possible to the deadline to minimize the risk of loosing the value. For low risk commitments this tendency is still present but expected to be looser. In order to test these predictions in a quantitative way, we performed data analysis for the total number of registrations and fee payments vs. time for the recent scientific conference “Statphys 23”, comparing it with the data of another conference in order to recover universal features. Two related models respectively for registrations (weak engagement) and fee payment (strong engagement) are then introduced which are able to explain in a simple way both behaviors, and which show an excellent agreement with real data.      

Evaluation of Autoradiograms by Microdensitometry and Imaging

The aim of this work is to compare results of the densitometric evaluation techniques used in the Central Research Institute for Physics Budapes: (KFKI) to that performed at the Central Institute of Isotope and Radiation Research Leipzig (ZfI) on purpose to improve the resolution and precision respectively. Optical density distributions along defined lines of the autoradiograms are measured by a JOYCE LOEBL Double Beam Recording Microdensitometer type MK-III.CS in the KFKI laboratory and by a modified ZEISS-Schnellphotometer G2 in the ZfI laboratory. A full screen imaging of the autoradiograms may be performed by means of the DENSITRON 4 image analyzer developed in ZfI. Results obtained in this work will be discussed.     

Critique of multinomial coefficients method for evaluating Tsallis and Rényi entropies

Oikonomou [Th. Oikonomou, Physica A 386 (2007) 119] has published a calculation which purports to show that the Tsallis and Rényi entropies can be obtained from the generalized multinomial coefficients. In this paper, we prove that the method of generalized multinomial coefficients failed to determine the Tsallis entropy at equilibrium. Moreover, it is shown that Oikonomou’s analysis contains mistakes which led to misleading statements related to the Jaynes principle of maximum entropy, the Tsallis and the Rényi statistics.     

分子振转光谱的计算机辅助标识

介绍一种计算机辅助分子光谱振转标识的交互式软件,它的主要功能是根据二次逐差原理自动将谱线分组,挑取各个支带；然后用图解的方式,以谱线频率和强度为坐标轴,将选取的各组谱线按不同的颜色或线形绘成柱状图,清晰地显示出隐藏在复杂分子光谱中的振转结构；而且,同时可以作出Loomis-Wood图辅助光谱振转标识。将本软件应用到由三氯化磷和氦气放电生成的包含多种分子的复杂光谱中,取得了满意的结果,有效地辅助了光谱的振转分析。该软件适用于对称陀螺分子和轻微不对称陀螺分子和线形分子的光谱分析。     

计算机辅助的数字通信频谱分析

从Fourier级数出发 ,到任意闭区间上可积函数的Fourier分析 ,给出了数字信号Fourier分析的理论基础。以字符“b”为例 ,建立了严格的数学模型 ,严密推导了Fourier系数表达式。阐明了Fourier级数的“项”和“n阶Fourier级数”(前n项和 )的概念。详尽地分析了信道通频带B与Fourier阶数n(展开式“保留”项 )的关系。借助计算机计算了n≤ 10 0时各Fourier级数项和前n项和 ,并用Plot将计算结果绘成曲线 ,获得n≤10 0时各级Fourier展开曲线。与数字信号对照 ,Fourier级数的取项与波形的关系显而易见 ,特别是n取值较小时 ,Fourier级数取项少 ,波形失真严重 ;所以在B一定时传输速率不能过高 ,否则 ,由于波形失真而导致信号出错。     

The Calculation of the Relative Irradiation Dose Rate of a High-Power Gamma-Source by Digital Computer

Authors have elaborated a method which allows a digital computer to be applied for the calculaiton of the relative irradiation dose rates of the K-120.000 ⁶⁰Co gamma irradiation source with a specific activity of 80.000 Ci. The model used takes into consideration is the joint effect of 80 source-elements which were one-dimensional but of different activities and arranged in four layers one above the other, around one/two imaginary cylinder superficies. In possession of chemical or physical dosimetry data this method can be applied also for the calculation of the absolute irradiation dose ratres. According to the experiences obtained so far, over a distance of 6 cm-s from the source-elements the error of the computed absolute irradiation dose rate data is less than 5%.     

Comment on “Critique of multinomial coefficient method for evaluating Tsallis and Rényi entropies” by A.S. Parvan

Parvan [A.S. Parvan, Critique of multinomial coefficients method for evaluating Tsallis and Rényi entropies, Physica A 389 (2010) 5645] has recently presented some calculations in order to demonstrate the incorrectness of the results obtained from the generalized multinomial coefficients (GMC) presented in Oikonomou (2007) [1]. According to Parvan, the aforementioned approach of studying maximum entropy probability distributions is erroneous. In this comment I demonstrate that Parvan’s arguments do not hold true and that the obtained results from GMC do not present either mathematical or physical discrepancies.     

Application of Autoradiography to the Investigation of New Doping Techniques of Semiconductor Materials

The development of technology of new semiconductor devices requires fundamental studies of a number of phenomena taking place in semiconductors during the doping process or accompanying the doping process.

These studies are concerned with the following problems:

1. Diffusion of gold in silicon and the effect of diffusion layers (particularly phosphorus layers) and epitaxial silicon layers on the distribution of gold in thin silicon plates.

2. Distribution of admixtures in silicon introduced with the aid of the ion implantation technique. Our studies concerned with the second of the above mentioned problems comprised an autoradiographic examination of the homogeneity of the beam of phosphorus ions implanted in silicon, and a study of some apparatus factors and of the purity of the basic material on the implantation.     

Theorie und Optimierung der radiometrischen Absorptionsmethode zur Analyse von Binärsystemen

Die Arbeit behandelt theoretisch das Auflösungsvermögen der Absorptionsmethode zur Analyse von Binārsystemen bei Anwendung von monoenergetischer Gamma- und Rötgenstrahlung. Es wird eine analytische Beziehung für die Funktion Δp abgeleitet, die die kleinstmöglichen Veränderung in der Zusammensetzung des Systems chgarakterisiert und die wir noch mittelts dieser Methode in Abhängigkeit von allen zu berückischtigenden Faktoren bestimmen könne. Aus den Extremwerten der Funktion Δp werden dann die optimalen Werte der Energine, der Schichtdicke, der Strahlungshäufigkeit und die Optimalwerte der restlichen Parameter so bestimmt, daβ das Auflösungsvermögen der Methode maximal ist. Die Theorie wird auf eine Ag-Cu-Legierung angewendet.     

Computer simulation study of a two-dimensional dipolar lattice

Summary The present work reports Monte Carlo calculations on a classical square lattice, consisting of purely dipolar plane rotators with identical dipole moments. Dipolar interactions are known not be essential for nematic ordering, but they can play a significant role in some specific cases; along the lines of the lattice model approximation already used in simulation work on liquid crystals, our system can be considered as an extreme case of nematogenic potential model. The system possesses an antiferroelectric ground state and, at higher temperature, it undergoes a transition to an orientationally disordered phase; comparison with the mean-field treatment of the transition is also reported. The structural properties were investigated by calculating orientational correlation functions, and found to exhibit some qualitative differences with respect to other potential models previously investigated for nematics. Simulation results indicate a close qualitative similarity with a three-dimensional analogue investigated in our previous work.

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Riassunto Il presente lavoro riporta calcoli Monte Carlo per un reticolo classico quadrato, costituito da rotatori piani puramente dipolari, con identici momenti. è noto che le interazioni dipolari non sono essenziali per l'ordinamento nematico, ma esse possono avere un ruolo significativo in alcuni casi specifici; lungo le linee dell'approssimazione a modello reticolare già applicata in lavori di simulazione per cristalli liquidi, il nostro sistema può pertanto venire considerato come un caso estremo di modello di potenziale nematogenico. Il sistema possiede stato fondamentale antiferroelettrico ed, a temperatura piú elevata, transisce ad una fase orientazionalmente disordinata; si riportano per confronto i risultati della trattazione a campo medio per tale transizione. Le proprietà strutturali furono investigate calcolando funzioni di correlazione orientazionale, e si è trovato che esse mostrano qualche differenza qualitativa rispetto ad altri modelli di potenziale previamente studiati per nematici. I risultati di simulazione indicano una stretta somiglianza qualitativa con un analogo tridimensionale investigato in nostri precedenti lavori.

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Резюме В этой работе предлагаются вычисления по методу Монте-Карло для классической квадратичной решетки, состоящей нз чнсто дипольных плоских ротаторов с тождественными дипольными моментами. Известно, что дипольные взаимодействия не являются существенными для нематического упорядочения, но они могут играть существенную роль в некоторых специфических случаях: в частности, в приближении модельной решетки, уже использованном при моделировании на жидких кристаллах, наша система может рассматриваться как предельный случай модели немтическочо потенциала. Рассмотренная система обладает антиферромагнитным основным состоянием и при высоких температурах она претерпевает переход в ориентационно разупорядоченную фазу; также проводится сравнение с рассмотрением этого перехода с помощью среднего поля. Исследуются структурные свойства, вычисляя ориентационные корреляционные функции. Обнаружено существование некоторых качественных различий по сравнению с моделями потенциалов, ранее использованных для нематиков. Результаты моделирования обнаруживают качественное подобие с трехмерным аналогом, исследованным в нашей предыдущей работе.

     

Computer simulation study of a simple cubic dipolar lattice

Summary The present work reports Monte Carlo calculations on a classical simple cubic lattice, consisting of point dipoles with identical dipole moments. Dipolar interactions are known not to be essential for nematic ordering, but they can play a significant role in some specific cases; along the lines of the lattice model approximation already used in simulation work on liquid crystals, our system can thus be considered as an extreme case of nematogenic potential model. The system possesses an antiferroelectric ground state and, at higher temperature, it undergoes a transition to an orientationally disordered phase; comparison with mean-field and spherical-model treatments of the transition is also reported. The structural properties were investigated by calculating orientational correlation functions and found to exhibit some qualitative differences with respect to other potential models previously investigated for nematics.

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Riassunto Il presente lavoro riporta calcoli Monte Carlo per un reticolo classico cubico semplice, costituito da dipoli puntiformi con identico momento dipolare. è noto che le interazioni dipolari non sono essenziali per l’ordinamento nematico, ma esse possono avere un ruolo significantivo in alcuni casi specifici; lungo le linee dell’approssimazione a modello reticolare già applicata in lavori di simulazione per cristalli liquidi, il nostro sistema può pertanto essere considerato come un caso estremo di modello di potenziale nematogenico. Il sistema possiede stato fondamentale antiferroelectrico ed, a temperature piú elevata, transisce ad una fase orientazionalmente disordinata; sono riportati per confronto i risultati delle trattazioni a campo medio, ed a modello sferico per tale transizione. Le proprietà strutturali furono investigate calcolando funzioni di correlazione orientazionale, e si è trovato che esse mostrano qualche differenza qualitativa rispetto ad altri modelli di potenziale previamente studiati per nematici.

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Резюме В работе предлагается моделирование по методу Монте-Карло классической простой кубической решетки, образованной точечными диполями с тождественными дипольными моментами. Известно, что дипольные взаимодействия не являются существенными для нематическояо упорядочения, но они игроют существенную роль в некоторых специфических случаях. Рассматриваемая система обладает антиферроэлектрическим основным состоянием и, при высокой темлературе, претерпевает переход в ориентационно упорядоченную фазу. Проводится сравнение с приближ=yeнием среднего поля и рассмотрением в рамках сферической модели этого перехода. Псследуутся структурные свойства, посредством вычисления ориентационных корреляционных функций. Обнаружены нектторые ксчественные различия по сравнению с другими потенциалыми моделями, ранее рассмотренными для описания нематики.

     

Nonextensivity in geological faults?

Geological fault systems, as the San Andreas fault (SAF) in USA, constitute typical examples of self-organizing systems in nature. In this paper, we have considered some geophysical properties of the SAF system to test the viability of the nonextensive models for earthquakes developed in [R. Silva, G.S. França, C. Vilar, J.S. Alcaniz, Phys. Rev. E 73 (2006) 026102]. To this end, we have used 6188 earthquakes events ranging in the magnitude interval 2<m<8$2<m<8$ that were taken from the Network Earthquake International Center catalogs (NEIC, 2004–2006) and the Bulletin of the International Seismological Centre (ISC, 1964–2003). For values of the Tsallis nonextensive parameter q?1.68$q?1.68$, it is shown that the energy distribution function deduced in above reference provides an excellent fit to the NEIC and ISC SAF data.     

Possible generalization of Boltzmann-Gibbs statistics

With the use of a quantity normally scaled in multifractals, a generalized form is postulated for entropy, namelyS _q k [1 – _i=1 ^W p _i ^q ]/(q-1), whereq characterizes the generalization andp _i are the probabilities associated withW (microscopic) configurations (W). The main properties associated with this entropy are established, particularly those corresponding to the microcanonical and canonical ensembles. The Boltzmann-Gibbs statistics is recovered as theq1 limit.     

Incomplete nonextensive statistics and the zeroth law of thermodynamics

On the basis of the entropy of incomplete statistics (IS) and the joint probability factorization condition, two controversial problems existing in IS are investigated: one is what expression of the internal energy is reasonable for a composite system and the other is whether the traditional zeroth law of thermodynamics is suitable for IS. Some new equivalent expressions of the internal energy of a composite system are derived through accurate mathematical calculation. Moreover, a self-consistent calculation is used to expound that the zeroth law of thermodynamics is also suitable for IS, but it cannot be proven theoretically. Finally, it is pointed out that the generalized zeroth law of thermodynamics for incomplete nonextensive statistics is unnecessary and the nonextensive assumptions for the composite internal energy will lead to mathematical contradiction.     

Noise composed of multiplication of two dichotomous noises

In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study the resonant activation phenomenon, the phenomenon of stochastic resonance, the transport of particles, and the nonequilibrium （phase） transition for the systems driven by this noise.     

Multi-fractal analysis of highway traffic data

The purpose of the present study is to investigate the presence of multi-fractal behaviours in the traffic time series not only by statistical approaches but also by geometrical approaches. The pointwise H\"{o} lder exponent of a function is calculated by developing an algorithm for the numerical evaluation of H\"{o} lder exponent of time series. The traffic time series observed on the Beijing Yuquanying highway are analysed. The results from all these methods indicate that the traffic data exhibit the multi-fractal behaviour.