RG64—High Count Rate Low Noise Multichannel ASIC With Energy Window Selection and Continuous Readout Mode

We report on the performance of a low noise and high count rate readout ASIC with binary architecture and energy window selection for X-ray imaging applications using semiconductor detectors. The ASIC called RG64 is designed in 0.35 mum CMOS process and its total area is 3900times5000 mum². The core of RG64 consists of 64 readout channels. Each channel is built of a charge sensitive amplifier with a second order shaper of peaking time 75 ns, two independent discriminators with an 8-bit offset correction circuit and two independent 20-bit counters with RAM memory buffers. The ENC of the circuit reaches the value of about 126 el. rms with 1 pF input load and 5 mW power consumption per single channel. The mean gain in the multichannel ASIC is about 50 muV/el., with the dispersion from channel to channel of 0.9% (on one sigma level). The deviation of the effective threshold voltage spread for given energy can be reduced to less than 7 el. rms (calculated to the charge sensitive amplifier input). High count rate measurements have been performed up to 2 Mcps of average rate of input pulses, both for AC and DC coupled silicon strip detectors with X-ray photons of energy 8.04 keV. The RG64 can operate both in the continuous readout mode and in the readout mode separate from exposure.     

Ensemble Online Classifier Based on the One-Class Base Classifiers for Mining Data Streams

The problem addressed in this study concerns mining data streams with concept drift. The goal of the article is to propose and validate a new approach to mining data streams with concept-drift using the ensemble classifier constructed from the one-class base classifiers. It is assumed that base classifiers of the proposed ensemble are induced from incoming chunks of the data stream. Each chunk consists of prototypes and information about whether the class prediction of these instances, carried-out at earlier steps, has been correct. Each data chunk can be updated by using the instance selection technique when new data arrive. When a new data chunk is formed, the ensemble model is also updated on the basis of weights assigned to each one-class classifier. In this article, two well-known instance-based learning algorithms—the CNN and the ENN—have been adopted to solve the one-class classification problems and, consequently, update the proposed classifier ensemble. The proposed approaches have been validated experimentally, and the computational experiment results are shown and discussed. The experiment results prove that the proposed approach using the ensemble classifier constructed from the one-class base classifiers with instance selection for chunk updating can outperform well-known approaches for data streams with concept drift.     

The Influence of Process Parameters on the Low-Cycle Fatigue Properties of 316L Steel Parts Produced by Powder Bed Fusion

Metallurgical and Materials Transactions A - In this paper, the influence of the additive manufacturing (AM), powder bed fusion (PBF) process parameters on the low-cycle fatigue (LCF) properties of...     

An electrically controlled quantum dot based spin current injector

We present a proposal for a fully electrically controllable quantum dot based spin current injector. The device consists of a quantum dot that is strongly coupled to a ferromagnetic electrode on one side and weakly coupled to a nonmagnetic electrode on the other side. The presence of the ferromagnetic electrode results in an exchange field that splits the dot level. We show that this exchange-induced splitting can lead to almost full spin polarization of the current flowing through the device. Moreover, we also demonstrate that the sign of polarization can be changed by the gate or the bias voltage within a switching time in the nanosecond range. Thus, the proposed device can operate as an electrically controlled, rapidly switchable spin current source, which can be realized in various state-of-the-art nanostructures.     

Immobilization of hospital waste incineration ashes in glass-ceramic composites

In the paper process of sintering of hospital incineration ash as a counterpart of low-level active waste with borosilicate glass frit is presented. It is shown that low porosity glass-ceramic waste-form can be obtained at a temperature range of 850–900 °C. In the sinter, the main crystal phases are wollastonite and aegirine-augite pyroxenes which have a large isomorphous capacity of binding hazardous elements. The crystal phases are fully encapsulated by the glass that provides additional protection against environmental influence. Thus, multibarrier material can be obtained at a temperature considerably lower than vitrification. This, in turn, can improve the economics of immobilization process.     

Morphological,Anatomical, and Phytochemical Studies of Carlina acaulis L. Cypsela

Carlina acaulis L. has a long tradition of use in folk medicine. The chemical composition of the roots and green parts of the plant is quite well known. There is the lowest amount of data on the cypsela (fruit) of this plant. In this study, the microscopic structures and the chemical composition of the cypsela were investigated. Preliminary cytochemical studies of the structure of the Carlina acaulis L. cypsela showed the presence of substantial amounts of protein and lipophilic substances. The chemical composition of the cypsela was investigated using spectrophotometry, gas chromatography with mass spectrometry, and high-performance liquid chromatography with spectrophotometric and fluorescence detection. The cypsela has been shown to be a rich source of macro- and microelements, vegetable oil (25%), α-tocopherol (approx. 2 g/kg of oil), protein (approx. 36% seed weight), and chlorogenic acids (approx. 22 g/kg seed weight). It also contains a complex set of volatile compounds. The C. acaulis cypsela is, therefore, a valuable source of nutrients and bioactive substances.     

AGENT-BASED APPROACH TO THE DESIGN OF RBF NETWORKS

This article proposes a novel approach to the radial basis function network (RBFN) design. Its main idea is to apply the agent-based population learning algorithm to the task of initialization and training RBFNs. The approach allows for an effective network initialization and estimation of its output weights. The initialization involves two stages, where in the first one initial clusters are produced using the similarity-based procedure and next, in the second stage, prototypes (centroids) from the thus-obtained clusters are selected. The agent-based population learning algorithm is used to select prototypes. In the proposed implementation of the algorithm, both tasks—RBFN initialization and RBFN training—are carried out by a team of agents executing various local search procedures and cooperating with a view to determine the solution to the RBFN design problem at hand. The performance of the RBFN constructed using the proposed agent-based approach is analyzed and evaluated. The proposed approach is also compared with different RBFN initialization and training procedures in the literature.     

Patenting medical and surgical techniques: an ethical-legal analysis

Considerable controversy has recently arisen regarding the patenting of medical and surgical processes in the United States. One such patent, viz. for a "chevron" incision used in ophthalmologic surgery, has especially occasioned heated response including a major, condemnatory ethics policy statement from the American Medical Association as well as federal legislation denying patent protection for most uses of a patented medical or surgical procedure. This article identifies and discusses the major legal, ethical and public policy considerations offered by proponents and opponents of such patents. The existing literature divides up into those who favor such patents essentially without qualification, and those who condemn and wish to outlaw them. We advance a compromise position where administrative and legislative action is called for to provide more specific guidelines regarding the patentability of such processes by the Patent and Trademark Office. Our position, in sum, will be that too much is at stake in this complicated area for either the blanket prohibition, or wholesale, uncritical acceptance, of the patenting of medical and surgical processes or techniques.