X‐ray analysis without the need for standards

Nasir, Mazshurraiezal

doi:10.1111/j.1365-2818.1976.tb01081.x

Cited by 14 publications

(11 citation statements)

References 3 publications

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“…In recent reports (Colby, 1968(Colby, , 1982Goldstein et al, 1976;Horita et al, 1987;Nasir, 1976;Zaluzec et al, 1976) the quantitative analysis of thin specimens has been employed easily and speedily without standard samples. However, it is difficult to apply for many different types of specimen with respect to accuracy (Fiori et al, 1976;Joy and Maher, 1977) because the statistical calculations for these techniques are different and the results of quantitative analysis are different, even for the same sample.…”

Section: Introductionmentioning

confidence: 99%

Transmission electron microscopic X‐ray quantitative analysis of human dentin at 200 kV accelerating voltage

Yonehara

Shinohara

Kanaya

1990

J. Elec. Microsc. Tech.

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Qualitative and quantitative x-ray energy dispersive spectroscopy is now used successfully to analyze many features and processes in inorganic samples. When applied to inorganic samples, however, the results are often less satisfactory due to problems of preparation of organic samples, difficulty of measuring x-rays from organic samples, damage of the sample by the electron beam, and other practical problems. In the present study we used a high voltage transmission electron microscope equipped with an energy dispersive x-ray spectrometer to examine accurate quantitative standardless analysis of thin sections of an organic sample, human dentin. Based on our experiments we found the important parameters for quantitative analysis were sample thickness and appropriate choice of model sample. Further, we show that the method of Cliff and Lorimer can be used with biological samples at 200 kV, and we show that quantitative analysis of human dentin can be carried out at 200 kV. Finally, we show that areas of human dentin can be differentiated by their morphological characteristics and x-ray analyses obtained in the transmission electron microscope.

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Section: Introductionmentioning

confidence: 99%

Transmission electron microscopic X‐ray quantitative analysis of human dentin at 200 kV accelerating voltage

Yonehara

Shinohara

Kanaya

1990

J. Elec. Microsc. Tech.

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“…is expectation operation), α is path loss factor, P S represents transmitted power of the source node, n r assumed as AWGN noise with CN(0,σ 2 n r ). In [20], the time switching-based relaying (TSR) protocol is proposed and harvested energy at (R) can be expressed as…”

Section: Symmetric Two-hop Relaying Modelmentioning

confidence: 99%

“…In the power splitting-based relaying (PSR) protocol suggested in [20], the transmitted energy from source is divided into two components, δP S used as harvested power function and (1 − δ) P S served for data processing. Therefore, the energy harvesting is given as…”

Section: Symmetric Two-hop Relaying Modelmentioning

confidence: 99%

Exploiting Symmetric Energy Harvesting Protocol in Wireless Sensor Networks with Outdated Channel State Information: Protocol Design and Performance Analysis

Nguyen

Vozňák

2016

Preprint

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Wireless Powered Communication Networks (WPCN), which has attracted much attention of researchers, also been recently recommended in 5 th generation (5G) wireless networks. With the help of the WPCN, the reliability and battery life of wireless low-power devices can be improved. In this paper, we investigate throughput and ergodic capacity in WPCN-assisted amplify-and-forward (AF) relaying system, considering two transmission modes including delay-tolerant and delay-limited. As important achievement, we propose symmetric energy harvesting protocol, namely time power switching relaying (TPSR) in order to find maximal throughput. In particular, both time switching and power switching coefficients in this schemes are considered. Unlike most of the previous works, we further focus on impact of outdated channel state information (CSI) in this WPCN. In order to evaluate information processing efficiency, the performance can be substantially improved by optimally harvesting time and power coefficients of the received signal at relay node for energy and information extraction, and by deploying several scenarios. By deploying Monte Carlo simulation, it is confirmed that the system performance is more sensitive to CSI estimation error, noise variance, signal-to-noise ratio (SNR) and resulting in other reasonable computations of TPSR need be deployed to obtain QoS requirement.Keywords: channel state information; energy harvesting; amplify-and-forward; time power switching relaying; throughput IntroductionRecently, the importance of harvested energy is widely recognized, when 5G cellular networks require high speed data and continuing operation. In [1], wireless powered communication network (WPCN) was presented the possibility of reliable data and wireless energy transfer technique in terms of interference channel. In principle, radio-frequency (RF) harvested energy is considered as a monotonous self-sustainability supply and it can use redundant power from ambient environment. In [2], the research results proved that the capacity can be enhanced even in the frequency-selective channels. Furthermore, in [1],[2] the receiver might encrypt the received signal and process energy collection in the same time slot. Unfortunately, the past works proved that it did not use to be applicable to receiver circuit technology, due to limitations of cheap capacitors.In addition, thanks to recent advancements of circuit, it is confirmed that WPCN is feasible, since the capability extending coverage range of relaying wireless network and then it combines with RF-based energy harvesting to become key factors of next generations wireless systems [3]- [9]. In

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“…Although methods have been proposed for absolute quantitation of X-ray spectra, derived from physical principles (Nasir, 1976), it is the invariable practice in biological X-ray microanalysis to perform absolute quantitation by comparison of X-ray spectra of the specimens with those of artificial standards containing the elements of interest at known concentrations. Such standards should be designed to resemble the specimen as closely as possible in several ways, such as matrix composition (affecting X-ray absorption) and susceptibility to radiation damage.…”

Section: Absolute Quantitation: the Preparation And Use Of Standardsmentioning

confidence: 99%

X-ray microanalysis: a histochemical tool for elemental analysis

1983

Histochem J

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The interactions of electrons with specimens Types of interactionsWhen electrons strike an object, as in an electron microscope, a number of interactions occur that can be, and are, used to give information about the specimen (Table 1). The various types of interactions of electrons that are used to produce images in scanning or transmission electron microscopes are familiar to most biologists, in the form of electron micrographs. The density of a transmission electron micrograph is dependent on the mass of the specimen at that point; because of this, staining and histochemical methods have been developed for electron microscopy using heavy metals. In scanning electron microscopy, the generation of back-scattered electrons is also dependent on atomic number. The information that can be obtained about the composition of the specimen in these ways is, however, extremely crude compared with that obtainable by some other methods. Among these other methods is X-ray microanalysis (also known as electron probe microanalysis) which is foremost among such techniques at present for ease of application and interpretation, and availability of commercial equipment. In X-ray microanalysis, the electrons striking the specimen excite X-rays characteristic of the elements in the specimen. X-ray microanalysis is thus a form of elemental analysis. It has been applied to a wide variety of biological problems, and these will be considered later in the section entitled Some biological applications of X-ray microanalysis. The production of X-rays by electronsWhen an electron of sufficient energy passes through the cloud of electrons surrounding an atomic nucleus, it may cause the displacement of an inner orbital electron to an orbit of higher energy. In the process the primary electron is inelastically scattered; that is, it

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X‐ray analysis without the need for standards

Cited by 14 publications

References 3 publications

Transmission electron microscopic X‐ray quantitative analysis of human dentin at 200 kV accelerating voltage

Transmission electron microscopic X‐ray quantitative analysis of human dentin at 200 kV accelerating voltage

Exploiting Symmetric Energy Harvesting Protocol in Wireless Sensor Networks with Outdated Channel State Information: Protocol Design and Performance Analysis

X-ray microanalysis: a histochemical tool for elemental analysis

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