bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Simulation of a Compact 5.4GHz H-shaped Slot Antenna for RF Energy Harvesting Systems
Authors: Nagaraju D. , Gupta Narbada Prasad 
Published: January 2021

Abstract
in this paper, a compact H-shaped slot antenna is proposed. The antenna contains one H-shape slot which is fed through microstrip line, an open circuited stub is connected for proper impedance matching. The H- shaped slot is used for bandwidth enhancement. The antenna is designed to radiate at 5.4 GHz with a bandwidth of 1.6GHz. The antenna has an omni-directional pattern across the frequency band. The gain of the antenna is 4.35dBi at 5.4GHz. Since, the proposed antenna satisfies all the characteristics of energy harvesting systems, it can be used for energy harvesting systems, at 5.4GHz 4G-LTE band. CST microwave studio was used for designing the proposed antenna. An excellent agreement is achieved between simulated and measured results.
Multi-verse optimizer based Fuzzy-PI controller for robust frequency regulation in thermal-hydro power system
Authors: Sharma Mandeep , Dhundhara Sandeep , Singh Surinder , Verma Yajvender Pal 
Published: January 2021

Abstract
This study presents a frequency regulation scheme using a fuzzy-based proportional-integral (FUZZY-PI) controller for two areas non-reheat thermal-hydro power system. Optimal tuning of controller parameters is achieved through a newly established metaheuristic algorithm called Multi-Verse Optimizer (MVO) algorithm. The superiority of the proposed controller has been proven by comparing it with recently published control approaches. The different figure of merits is used to evaluate the performance of the offered controller. The attained results confirm the effectiveness of the designed controller for studied power systems.
Open Loop Trans-conductance Amplifier design for Neural Signals
Authors: Gupta Lipika , Kumar Amod 
Published: January 2021

Abstract
Robust neural recording systems require efficient amplification of weak neural signals at very first stage using Operational Trans-conductance Amplifier (OTA) which should consume minimum power, noise and area. However, there exist a tradeoff for improving the power, noise and area simultaneously. Open loop configuration of OTA has inherent property of lesser area due to absence of feedback; it also provides better noise performance under the given power budget as compared to closed loop counterparts. This paper focuses on the design of Open-loop amplifier OTA topology for non-invasive EEG signals. The simulation results show the improvement in the gain performance of the circuit at 180nm technology node while power and noise of the circuit remains comparable with the existing circuits.
Comparative Study of Optical and Structural Properties of PANI and PANI/CNT Synthesized by Chemical Oxidative Polymerization Method
Authors: Prashar Ankush , Nihal  
Published: January 2021

Abstract
PANI and PANI/CNT have been synthesized by the in-situ chemical oxidation polymerization method. The optical characterization is done by using UV/Vis spectroscopy, FTIR, and PLS. There is a decline in the Absorbance of PANI/CNT as compared to PANI. Similar results have been observed with PL spectra where PANI/CNT has a lower intensity than PANI. The XRD spectra show an increase in intensity for PANI/CNT as compared to PANI. The structural study has been done using the XRD technique. All the results confirm the formation of PANI and PANI/CNT.
Recrystallization of CL-20 to ε-polymorphic form
Authors: Chauhan B S , Thakur A , Soni P K , Kumar M 
Published: January 2021

Abstract
High explosive CL-20 (2,4,6,8,10,12 - Hexanitro - 2,4,6,8,10,12 - hexaazaisowurtzitane) exists in four polymorphic forms i.e. α, β, γ and ε polymorphs at ambient conditions and polymorph ζ exists only at high pressure (1.44 GPa). CL-20 is the only single compound having highest energy among all the organic substances. But polymorphic form α- of CL-20 is generally obtained during most of the synthetic processes which has low density and high sensitivity. Thus, there is requirement of further recrystallization to obtain most stable ε-polymorphic form. Owing to the highest density, superior thermal stability and better insensitivity of ε- polymorph over other three polymorphs (α-, β- and γ- form) which are highly sensitive towards impact, friction and shock, ε- CL-20 is most desirable for use in defence applications. The present work studies the effect of various variables which influence the crystallisation process like effect of moisture, nature of solvent/anti-solvent and time on the preparation of ε- form of CL-20. Ethyl acetate and n-butyl acetate as solvents and toluene as anti-solvent resulted in the formation of desired ε- polymorphic form successfully. Polymorphic form was confirmed by FTIR and XRD analysis. SEM analysis was carried out for the morphological analysis of prepared samples.
Aluminium-Carbon Fibre Metal Matrix Composites: A Review
Authors: Khanna Virat , Kumar Vanish , Bansal Suneev Anil 
Published: January 2021

Abstract
Manufacturing sector always demands superior materials that can cope up with the demand of improved mechanical properties to develop wide applications in diverse sectors. Carbon fibres (CFs) reinforcement in metals matrix is excellent in improving the properties resulting composites. The present review is emphasized on the major developments of using carbon fibres in recent years with aluminium (Al) metal as matrix to improve various mechanical properties. Several aspects (like tensile strength, hardness, shear strength etc.) contributing to the performance of Al-CFs composite have been discussed by covering several case studies. This review reveals that reinforcing CFs in Al matrix increases properties like tensile/shear strength, hardness, wear resistance etc. The mechanism involved in improving these properties is also discussed. Moreover, the remaining challenges in this field and future prospects are discussed in detail.
First Principle Calculations of Effect of Hydrostatic Pressure on Ga0.75Cr0.25P
Authors: Kaur Kirandish , Sharma Suresh 
Published: January 2021

Abstract
In this paper, the investigation of effect of hydrostatic pressure on the structural, electronic and magnetic properties of Ga0.75Cr0.25P ternary alloy in Zinc Blende (B3) phase at 0 GPa to 26 GPa pressure range has been done using first principle calculations as implemented in Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code. The theoretical investigation of electronic and magnetic properties of this compound represents that the compound is half-metallic ferromagnet and show 100% spin polarization at different values of pressure. It is found that band gap increases with increase in pressure as spin polarized band structures experience changes with applied pressure. The calculated results show that lattice constant and volume of compound decrease along-with increase in induced local magnetic moments values on non-magnetic gallium and phosphorus atoms with applied pressure.
Recent developments in synthesis, characterization and boiling heat transfer of nanofluids – A Review
Authors: Ravi Babu S , Saras Chandra A , Ramesh Babu P 
Published: January 2021

Abstract
The life of a thermal system depends on how effectively the heat (which is released during its operation), being transferred. Selection of the right fluid is imperative in providing the heat transfer solution for a particular thermal system. Nanofluids are the new generation heat transfer fluids which will give better performance with their superior thermos-physical properties. So much research has been done on nanofluids during the recent years on several aspects like synthesizing the stable nanofluids without losing their properties, characterization, application of nanofluids to forced convection, free convection, boiling heat transfer. The present review is concentrated mainly on the experimental investigations on the preparation and characterization of nanofluids and its applications in several areas. Majority of studies reported that critical heat flux improves with the nanofluids. It will be very useful for the researchers who are about to work on the nanofluids.
Thermodynamic and physiochemical properties and the excess functions of binary mixtures of Dimethylsulfoxide with Pyridine and Nitromethane at variable temperatures - 298 to 318K.
Authors: Kaur Manpreet 
Published: January 2021

Abstract
The density (ρ), viscosity (η), relative permittivity (ε), and ultrasonic velocity (u) in the binary mixture of Dimethylsulfoxide with Pyridine and Nitromethane have been measured at all composition and temperatures 298 K, 308 K, and 318 K. From the experimentally measured values, the excess molar volumes (VE) and the deviation in the viscosities (Δη), relative permittivity (Δε), and ultrasonic velocity (δu) have been correlated. The negative and the positive deviations in the excess functions have been discussed in terms of molecular interactions.
The effects due to a uniformly distributed load in a non-local thermoelastic solid in a frequency domain
Authors: Lata Parveen , Singh Sukhveer 
Published: January 2021

Abstract
In the present study the effects on a non-local thermoelastic solid under the two-dimensional deformation effects due to a uniformly distributed load in a frequency domain have been discussed. The nonlocal thermoelastic solid is homogeneous with the effect of two temperature parameters subjected to uniformly distributed source. Fourier transforms have been used to solve the problem. The analytical expressions of displacement and stress components have been obtained in the transformed domain. For obtaining the results in the physical domain, the numerical inversion technique has been applied. The results so obtained are depicted graphically to show the effect of non-local parameter on the components of displacements and stresses and conductive temperature.
Raman spectroscopy of interfacial transition zone in concrete doped with limestone powder and metakaolin
Authors: Krejcí Kotlanova M , Masek V 
Published: January 2021

AbstractThe interfacial transition zone in concrete with ordinary Portland cement (OPC) and concrete containing OPC and doped with 20% of limestone powder and 30% of metakaolin was studied by Raman spectroscopy - optical profilometry and cluster analysis. Mechanical properties, including strength characteristics and absorbability were tested after 28 days of curing. Concrete with ordinary Portland cement has lower density and absorbability and higher compressive and tensile strength than concrete with limestone powder and metakaolin. It has been found that a large amount of portlandite is formed in the interfacial transition zone in concrete with ordinary Portland cement. In concrete with the addition of metakaolin and limestone powder, the thickness of the interfacial transition zone is reduced, less portlandite is produced, but a thin layer of calcite is formed around quartz grains. This results in lower concrete strength in the area of the interfacial transition zone.
The external renders of the early 20th century architecture
Authors: Tislova R , Svoboda P , Vsiansky D 
Published: January 2021

Abstract
External renders are an essential part of the architecture of the first half of the 20th century. The aesthetic effect of such plasterwork was achieved by surface treatment, colouring or by using various filler components that acted with their colour or structure. The binder of the plasters was most often Portland cement which played an important role in the processing of plasters or surface finishes, and in addition, formed the functional properties of the plasters (hardness, durability, resistance to external conditions).
This paper summarizes the results of a survey focused on the characterization of components used for the creation of external rendering taken from several architecturally significant buildings in the city of Brno dating back to the first half of the 20th century (villas, apartment buildings, public apartment houses). The survey into the collected samples performed by means of petrographic (light polarizing microscopy) and phase (powder X-ray diffraction) analysis revealed interesting information concerning the wide range of materials (components) used and the craftsmanship involved in their processing, all of which fundamentally influence the art-craft and utility properties of the buildings. The information gathered can serve as an important source of information for the renovation of early 20th century architecture.
Impedance spectroscopy measurement of metakaolin-based alkali-activated building materials
Authors: Kusak I , Lunak M , Mizerova C , Rovnanik P 
Published: January 2021

Abstract
Cement-containing as well as cement-free building materials are regarded as dielectrics. Therefore, electrically conducting admixtures are to be added to them in order to increase their electrical conductivity. Steel or carbon fibres, metal powder, graphite, carbon soot or carbon nanotubes are commonly used for this purpose. The conductivity increase offers new application options, such as sensor property materials, self-heated materials, or electromagnetic smog shielding materials. The specimens of the mixes to be studied were subjected to an electrical analysis carried out within the frequency range from 100 MHz to 3 GHz by means of an ZNC vector analyser and an SPEAG-made DAK-12 coaxial probe and, furthermore, a dedicated automatically measuring device operating within the frequency range from 40 Hz to 1 MHz. The frequency spectra of interest were measured on various copolymer specimens differing from each other by the content of graphite and carbon nanotubes. Higher content of these admixtures increases the electrical conductivity and the building materials thus become easier to measure by means of electromagnetic measuring methods.
Instrumented dynamic tests of building materials
Authors: Sperl M , Gajdos L’ , Slizkova Z , Drdlova M 
Published: January 2021

Abstract
In some specific cases, the building structures can be exposed to extreme dynamic loads. Namely, it can be car crash, earthquake or the effect of explosion. For these cases, it is useful to know the dynamic mechanical properties of building materials. The paper presents two unique procedures for instrumented impact testing of building materials (concrete and sandstone). These tests may help in practice with selection of suitable materials for buildings and structures which may be threatened by dynamic effects of mechanical stresses. The method how to achieve a higher dynamic material stability is also presented.
The study on corrosion behavior and corrosion resistance of ultralow carbon high silicon iron-based alloy
Authors: Zhang Yue , Xiao Jun , Zhang Yishun , Liu Wei , Pei Wei , Zhao Aimin , Zhang Wei , Zeng Li 
Published: January 2021

Abstract
The ultralow carbon high silicon iron-based alloy (sample A) with a single ferrite matrix was prepared. The corrosion performance difference and mechanism between it and conventional high silicon cast iron (sample B) were systematically studied using optical microscope, scanning electron microscope, electric corrosion equipment, electrochemical corrosion workshop and atomic force microscope. The results show that the corrosion rate of ultralow carbon iron-based alloys was significantly lower than that of high-silicon cast iron. For example, the static corrosion rate after 310 h, the corrosion rate of sample A was 0.2399 g/(m2 · h), and the corrosion rate of sample B was 1.5159 g/(m2 · h). The potential difference of the substrate was significantly reduced. That is, the ultralow carbon iron-based alloy exhibits better corrosion resistance, which is mainly attributed to the denser passivation film formed on its surface. The results of microhardness show that the hardness of Sample A was higher than that of Sample B.
Arterial Endothelial Function and Related Factors in Elderly Patients With Essential Hypertension and Abdominal Obesity
Authors: Huang He-ling , Shen Yi-hua , Cai Xiao-qi , Zhang Ling-yu , Xie Liang-di 
Published: January 2021

Abstract

Background
To investigate arterial endothelial function and related factors in elderly patients with both essential hypertension and abdominal obesity.

Methods
A total of 658 elderly patients (≥60 years old) with essential hypertension and 64 elderly subjects without hypertension were recruited. Hypertension and obesity were defined based on blood pressure (≥140/90 mm Hg) and waist circumference (male ≥90, female ≥85 cm), respectively. Endothelium-dependent dilatation (EDD) of anterior tibial artery induced by reactive hyperemia was examined by high-resolution vascular ultrasound. Pearson correlation analysis, factorial analysis, and multiple linear regression analysis were undertaken to examine the related factors of EDD.

Results
Factorial analysis showed that hypertension and abdominal obesity were influence factors of EDD, but there was no interaction between them. From normotensive without abdominal obesity, normotensive with abdominal obesity, hypertensive without abdominal obesity, to hypertensive with abdominal obesity, a gradual decline in EDD was observed (9.37 ± 1.11%, 8.59 ± 0.99%, 7.70 ± 0.30%, and 6.75 ± 0.26%, respectively, P &lt; 0.05). In elderly hypertensive patients with abdominal obesity, EDD correlated with waist circumference (r = −0.139, P &lt; 0.05), systolic blood pressure (r = −0.245, P &lt; 0.05), pulse pressure (r = −0.287, P &lt; 0.05), and fasting glucose level (r = −0.131, P &lt; 0.05). Multivariate linear regression analysis revealed that EDD was associated with pulse pressure (β = −0.280, P &lt; 0.001) and waist circumference (β = − 0.141, P = 0.009).

Conclusions
In elderly patients with essential hypertension and central obesity, EDD is impaired, and negatively correlated with pulse pressure and waist circumference.
Umbrella of protection: spatial and temporal dynamics in a temperate butterfly Batesian mimicry system
Authors: Prusa Louis A , Hill Ryan I 
Published: January 2021

AbstractBatesian mimicry involves both spatial and temporal interactions between model, mimic and predator. Fundamental predictions in Batesian mimicry involve space, time and abundance; specifically, that the model and mimic are found in sympatry and that protection for the mimic is increased when predators interact with the model first and more frequently. Research has generally confirmed these predictions for Batesian mimicry at large spatial scales, with recent work on two nymphalid butterflies in western North America, the mimic Limenitis lorquini (Boisduval, 1852) and its model Adelpha californica (Butler, 1865) in western North America indicating that the mimic generally has lower abundance and emerges later in the season among widely separated populations in the California Coast Ranges and Sierra Nevada. However, no studies have investigated model–mimic dynamics at small scales in the temperate zone to test whether temporal habitat use and movements conform to predictions. If mimicry is as important a part of the biology of these temperate species as it is for their tropical counterparts, then in addition to emerging later and being less abundant overall, the mimic should be less widespread, should be less abundant in each habitat and should move less among available habitats. Our results using mark–release–recapture methods confirm these predictions and indicate that the mimic, L. lorquini, is enjoying an umbrella of protection against habitat specialist and generalist predators alike.
Testing calibration of phenotyping models using positive-only electronic health record data
Authors: Zhang Lingjiao , Ma Yanyuan , Herman Daniel , Chen Jinbo 
Published: January 2021

Summary
Validation of phenotyping models using Electronic Health Records (EHRs) data conventionally requires gold-standard case and control labels. The labeling process requires clinical experts to retrospectively review patients’ medical charts, therefore is labor intensive and time consuming. For some disease conditions, it is prohibitive to identify the gold-standard controls because routine clinical assessments are performed for selective patients who are deemed to possibly have the condition. To build a model for phenotyping patients in EHRs, the most readily accessible data are often for a cohort consisting of a set of gold-standard cases and a large number of unlabeled patients. Hereby, we propose methods for assessing model calibration and discrimination using such “positive-only” EHR data that does not require gold-standard controls, provided that the labeled cases are representative of all cases. For model calibration, we propose a novel statistic that aggregates differences between model-free and model-based estimated numbers of cases across risk subgroups, which asymptotically follows a Chi-squared distribution. We additionally demonstrate that the calibration slope can also be estimated using such “positive-only” data. We propose consistent estimators for discrimination measures and derive their large sample properties. We demonstrate performances of the proposed methods through extensive simulation studies and apply them to Penn Medicine EHRs to validate two preliminary models for predicting the risk of primary aldosteronism.
Hepatocellular carcinoma progression during bridging before liver transplantation
Authors: Renner P , Da Silva T , Schnitzbauer A A , Verloh N , Schlitt H J , Geissler E K 
Published: January 2021

Abstract

Background
Recipient selection for liver transplantation in hepatocellular carcinoma (HCC) is based primarily on criteria affecting the chance of long-term success. Here, the relationship between pretransplant bridging therapy and long-term survival was investigated in a subgroup analysis of the SiLVER Study.

Methods
Response to bridging, as defined by comparison of imaging at the time of listing and post-transplant pathology report, was categorized into controlled versus progressive disease (more than 20 per cent tumour growth or development of new lesions).

Results
Of 525 patients with HCC who had liver transplantation, 350 recipients underwent pretransplant bridging therapy. Tumour progression despite bridging was an independent risk factor affecting overall survival (hazard ratio 1.80; P = 0.005). For patients within the Milan criteria (MC) at listing, mean overall survival was longer for those with controlled versus progressive disease (6.8 versus 5.8 years; P &lt; 0.001). Importantly, patients with HCCs outside the MC that were downsized to within the MC before liver transplantation had poor outcomes compared with patients who never exceeded the MC (mean overall survival 6.2 versus 6.6 years respectively; P = 0.030).

Conclusion
Patients with HCCs within the MC that did not show tumour progression under locoregional therapy had the best outcomes after liver transplantation. Downstaging into the limits of the MC did not improve the probability of survival.
Prognostic factors determining the long-term success of liver transplantation in patients with hepatocellular carcinoma are still under discussion. A subgroup analysis of the SiLVER trial showed that disease control under bridging therapy is strongly associated with improved prognosis in terms of overall survival. However, in tumours exceeding the limits of the Milan criteria, downstaging did not restore the probability of survival compared with that of patients within the Milan criteria.