Improvement of the magnetic and electrical properties of Cu-Zn ferrites

Polycrystalline Cu-Zn ferrites substituted with different rare-earth ions (R = La, Nd, Sm, and Gd) are investigated. The initial permeability and homogeneity increased for samples with R = Nd, Sm, and Gd relative to the unsubstituted one (US). On the other hand, the magnetization and energy loss are decreased for all substituted samples. The electrical resistivity increased only for samples with R = La and Nd relative to US.     

A wide-band,high-precision CMOS rectifier

A novel architecture for a precision rectifier is introduced. A new arrangement of a MOS switch and an amplifier has been developed for better precision and higher switching speed. The precision rectifier can rectify signals as low as 10 mV and frequencies up to 20 MHz with excellent linearity.     

Two-phase biomass air-steam gasification model for fluidized bed reactors: Part III—model validation

The developed two-phase air-steam gasification model (Biomass Bioenergy, xxxxx) was validated using the experimental results obtained from a dual distributor fluidized bed reactor. The reactor was operated on wheat straw at various fluidization velocities, steam flow rates and biomass to steam ratios. A good agreement between the model predictions and experimental data was obtained under all operating conditions studied. The model predicted the temperatures of the bubble, emulsion and solid phases, the mole fractions of methane, hydrogen, carbon monoxide, carbon dioxide and nitrogen, and the higher heating value of the producer gas with high accuracy (R²=0.88–0.98). The correlation coefficient (R²) for the gas production was somewhat lower (0.75), which could be attributed to the assumption that the gases behaved ideally.     

Hybrid Au-CdSe and Ag-CdSe nanoflowers and core-shell nanocrystals via one-pot heterogeneous nucleation and growth

A general approach, based on heterogeneous nucleation and growth of CdSe nanostructures on Au or Ag nanocrystals, for the synthesis of Au-CdSe and Ag-CdSe hybrid nanostructures is developed. The new approach provides a versatile one-pot route for the synthesis of hybrid nanoflowers consisting of a gold or silver core and multipod CdSe rods or an intact CdSe shell with controlled thickness, depending on the nucleation and growth parameters. At lower growth temperatures such as 150 °C, the CdSe clusters are adsorbed on the surface of the metal cores in their surface defects, then multiple arms and branches form, resulting in nanoflower-shaped hybrid structures. Increasing the size of the metal core through the choice of the reducing and capping agents results in an improvement of the interface between the metal and CdSe domains, producing core-shell structures. The growth temperature appears to be the most important factor determining the nature of the interface between the metal and CdSe domains. At relatively high temperatures such as 300 °C, the formation of large, faceted Au cores creates preferential growth sites for the CdSe nanocrystalline shell, thus resulting in well-defined Au-CdSe core-shell structures with large interfaces between the Au and CdSe domains. The present approach is expected to foster systematic studies of the electronic structures and optical properties of the metal-semiconductor hybrid materials for potential applications in photovoltaic and nanoelectronic devices.     

Field analysis: A mathematical method of analysis for information handling processes

A general method of analysis, mathematical in nature, is proposed for the abstract study of information handling processes. The method is based on an extension of the field concept as used in physical sciences, and makes no reference to data processing considerations. Thus, theory and practice are neatly separated so that each can progress on its own, helped but unhindered by the other. The paper details the method proposed and illustrates it with a preliminary analysis of information processing for selective mailings of periodicals. The analysis leads to a set of equations from which the values of all the derived information fields can be rigorously calculated. The discussion at the end of the paper helps to relate the present work to research relevant to the specification, documentation, design, and implementation of computer-aided information processing systems.The views expressed are those of the author and do not necessaril' represent those of the Ministry of State for Urban Affairs.Since this article was submitted, the author's name has been changed to S. H. Talbert.     

Assessment of RACGAP1 as a Prognostic and Immunological Biomarker in Multiple Human Tumors: A Multiomics Analysis

Several recent studies have pointed out that arc GTPase activating protein 1 (RACGAP1) is a putative oncogene in many human tumors. However, to date, no pan-cancer analysis has been performed to study the different aspects of this gene expression and behavior in tumor tissues. Here, we applied several bioinformatics tools to perform a comprehensive analysis for RACGAP1. First, we assessed the expression of RACGAP1 in several types of human tumors and tried to correlate that with the stage of the tumors analyzed. We then performed a survival analysis to study the correlation between RACGAP1 upregulation in tumors and the clinical outcome. Additionally, we investigated the mutation forms, the correlation with several immune cell infiltration, the phosphorylation status of the interested protein in normal and tumor tissues, and the potential molecular mechanisms of RACGAP1 in cancerous tissue. The results demonstrated that RACGAP1, a highly expressed gene across several types of tumors, correlated with a poor prognosis in several types of human cancers. Moreover, it was found that RACGAP1 affects the tumor immune microenvironment by influencing the infiltration level of several immune cells. Collectively, the current study provides a comprehensive overview of the oncogenic roles of RACGAP1, where our results nominate it as a potential prognostic biomarker and a target for antitumor therapy development.     

Throughput enhancement of cognitive M2M networks based on NOMA for 5G communication systems

One of the promising technologies for 5G cellular networks is machine‐to‐machine (M2M) communications. We propose a cognitive radio network (CR) that includes a primary cellular system and a secondary cognitive system. The primary cellular system has a primary client (PC) and the secondary cognitive system has M2M clients which are called secondary clients (SCs). In a conventional system of CR network based on orthogonal frequency division multiple access (CR‐OFDMA), when the primary client (PC) is absent, only one SC can obtain the idle spectrum. But, the SC must leave the spectrum when detecting the existence of the PC. So, the spectrum usage of this system is very low. This paper proposes a cooperative CR network based on nonorthogonal multiple access (CCR‐NOMA) for spectrum sensing using energy detection (ED) to allow multiple SCs to share the same frequency at the same time, but are differentiated according to the power domain or code domain, to improve spectrum efficiency of 5G communications and the transmission performance of CR network at the absence and presence of the PC. To evaluate the channel sensing performance of the ED technique in CCR‐NOMA, we derived a closed‐form expression between the achievable throughput and sensing time for the CCR‐NOMA system. The same analysis for the case of CR‐OFDMA is reproduced for the sake of comparison. The analysis showed that the CR‐NOMA system for M2M communication outperforms the CR‐OFDMA system for M2M communication for the same noncooperative and cooperative spectrum sensing and physical layer parameters.