Spectrum Parameters Research Articles

Contactless Temperature Sensing at the Microscale Based on Titanium Dioxide Raman Thermometry.

The determination of local temperature at the nanoscale is a key point to govern physical, chemical and biological processes, strongly influenced by temperature. Since a wide range of applications, from nanomedicine to nano- or micro-electronics, requires a precise determination of the local temperature, significant efforts have to be devoted to nanothermometry. The identification of efficient materials and the implementation of detection techniques are still a hot topic in nanothermometry. Many strategies have been already investigated and applied to real cases, but there is an urgent need to develop new protocols allowing for accurate and sensitive temperature determination. The focus of this work is the investigation of efficient optical thermometers, with potential applications in the biological field. Among the different optical techniques, Raman spectroscopy is currently emerging as a very interesting tool. Its main advantages rely on the possibility of carrying out non-destructive and non-contact measurements with high spatial resolution, reaching even the nanoscale. Temperature variations can be determined by following the changes in intensity, frequency position and width of one or more bands. Concerning the materials, Titanium dioxide has been chosen as Raman active material because of its intense cross-section and its biocompatibility, as already demonstrated in literature. Raman measurements have been performed on commercial anatase powder, with a crystallite dimension of hundreds of nm, using 488.0, 514.5, 568.2 and 647.1 nm excitation lines of the CW Ar+/Kr+ ion laser. The laser beam was focalized through a microscope on the sample, kept at defined temperature using a temperature controller, and the temperature was varied in the range of 283–323 K. The Stokes and anti-Stokes scattered light was analyzed through a triple monochromator and detected by a liquid nitrogen-cooled CCD camera. Raw data have been analyzed with Matlab, and Raman spectrum parameters—such as area, intensity, frequency position and width of the peak—have been calculated using a Lorentz fitting curve. Results obtained, calculating the anti-Stokes/Stokes area ratio, demonstrate that the Raman modes of anatase, in particular the Eg one at 143 cm−1, are excellent candidates for the local temperature detection in the visible range.

A Machine-learning Approach to Integral Field Unit Spectroscopy Observations. II. H ii Region Line Ratios

Abstract In the first paper of this series, we demonstrated that neural networks can robustly and efficiently estimate kinematic parameters for optical emission-line spectra taken by SITELLE at the Canada–France–Hawaii Telescope. This paper expands upon this notion by developing an artificial neural network to estimate the line ratios of strong emission lines present in the SN1, SN2, and SN3 filters of SITELLE. We construct a set of 50,000 synthetic spectra using line ratios taken from the Mexican Million Model database replicating H ii regions. Residual analysis of the network on the test set reveals the network’s ability to apply tight constraints to the line ratios. We verified the network’s efficacy by constructing an activation map, checking the [N ii] doublet fixed ratio, and applying a standard k-fold cross-correlation. Additionally, we apply the network to SITELLE observations of M33; the residuals between the algorithm’s estimates and values calculated using standard fitting methods show general agreement. Moreover, the neural network reduces the computational costs by two orders of magnitude. Although standard fitting routines do consistently well depending on the signal-to-noise ratio of the spectral features, the neural network can also excels at predictions in the low signal-to-noise regime within the controlled environment of the training set as well as on observed data when the source spectral properties are well constrained by models. These results reinforce the power of machine learning in spectral analysis.

Application of Frequency Domain Dielectric Response Method in Intelligent Location of Oil Paper Insulation Bushing Damp Fault

Oil paper insulating bushing is widely used in 500 kV and above power transformers. In order to quantitatively study the influence of water content on the dielectric spectrum of oil paper insulated bushing, HN model was used to fit and analyze the dielectric spectrum parameters of oil paper insulated bushing with different water content. The experimental results show that HN model can be used to evaluate the wettability of oil paper insulation, but the evaluation range of wettability of oil paper bushing with complex insulation structure is not clear. The results show that the relaxation time constant decreases with the increase of water content, and has a linear relationship with the change of water content; the difference between high frequency dielectric constant and static dielectric constant increases with the increase of water content.

Identification of defects in HV cable sheath based on equivalent impedance spectrum characteristic coding

In recent years, on-line monitoring and condition-based maintenance of HV cable systems have been extensively investigated to prevent cable fault. By analyzing cable sheath current, sheath defects can be identified. A new method of cable sheath defect identification is proposed in this study on the basis of the coding of the equivalent sheath impedance spectrum characteristics. In the proposed method, the sheath defects are identified by calculating the equivalent sheath impedance spectrum on the basis of the detected currents of the on-line sheath monitoring system. The equivalent circuit model of cross-bonded (CB) HV cable for sheath defect identification is constructed. The three-phase circuit model is decoupled to solve each phase independently in accordance with the CB scheme of the cable sheath. The equations of solving the equivalent sheath impedance are deduced. The criteria of sheath defect identification are proposed using the coding of characteristic parameters of the equivalent sheath impedance spectrum. Finally, a simulation model of the HV cable is built in the Simulink software to simulate 12 types of sheath defects. The simulation results have proven the correctness and efficiency of the proposed method.

FIR FILTER DESIGN WITH INERTIA WEIGHT AND COMPRESSION FACTOR APPROACH USING ADVANCED OPTIMIZATION TECHNIQUES

This paper includes the design of Finite impulse response filter with inertia weight and compression factor approach. The objective function of filter design involves accurate control of various parameters of frequency spectrum and is thus highly non-uniform, non-linear, non-differentiable and multimodal in nature. Classical optimization methods cannot converge to solutions. Because they have disadvantages such as highly sensitive to starting points, frequent convergence to local optimum solution or divergence or revisiting the same solution, requirement of continuous and differentiable objective cost function, requirement of the piecewise linear cost approximation and problem of convergence and algorithm. Evolutionary optimization methods for the design of optimal digital filters have better control of parameters and the highest stop band attenuation.

A Review on Modern Spectrum Sensing and Assignment Techniques in CRN

Cognitive radio (CR) is ascending as an advanced technology with the aim of utilizing the unused spectrum bands in an opportunistic and dynamic way. Fixed spectrum allocation done by government based agencies leads to underutilization of resources. The segments of spectrum bands that are unused, are called “spectrum holes” or “white spaces”. The solution to this issue is provided by implementing CR technology. It allows users to determine the unused bands in spectrum, choose the suitable one (depending on availability and accessibility of the spectrum) and use them in the best way possible. Spectrum assignment plays a vital role in minimizing any possibility of interference between secondary and primary users. Because of the varying parameters of available spectrum along with the different QoS specifications of various networks, CR technology raise a range of challenges. Spectrum management functions should tackle these problems and ensure that the CR network runs smoothly. This article therefore presents a brief survey on CR networks, its architecture and other relevant functionalities like spectrum sensing, spectrum decision, spectrum sharing, and spectrum mobility.

Digital Lighting Technologies to Control Galleria Mellonella Behavior

The authors found out that the greater wax moth (Galleria mellonella) harmed bee colonies by destroying up to 30 percent of honey in a beehive. They studied the results of experiments on controlling its behavior using a developed automated microprocessor system that maintained optical radiation sources duration.(Research purpose) To develop light technologies using a microprocessor-based automated system that allows controlling Galleria mellonella behavior by realizing attractive optical radiation characteristics.(Materials and methods) Galleria mellonella behavior was controlled by an automated system that the authors worked out for maintaining the required duration of the experiment and optical radiation parameters. The ATmega328 microcontroller was chosen as the main element of the developed microprocessor automated system. The authors created a program for it using visual programming FLProg version 5.3.0.(Results and discussion) The authors found that, regardless of the experiment duration, Galleria mellonella butterflies prefered radiation with 400 nanometers wavelength.(Conclusions) The authors determined that radiation with 400 nanometers wavelength and 10 minutes duration was attractive. They showed the ability to control Galleria mellonella behavior, luring butterflies to a specific place in the beehive with comfortable spectrum parameters. An automated system for controlling the greater wax moth butterfly behavior was developed on ATmega328 microcontroller by implementing attractive optical radiation characteristics.

An Elliptical CPW Fed UWB Slot Antenna

A new CPW fed elliptical antenna for ultra-wideband (UWB) is proposed. The novelty of this antenna are very small size and uniplanar structure, which results in easy and low cost fabrication. This antenna has elliptical slot configuration which is fed by the CPW. This elliptical slot UWB antenna is enclosed in the extended surface of ground for decreasing the chip surface area. This antenna is designed with the optimal design parameters for the UWB spectrum. The designed antenna is printed on FR4 substrate and Vector Network Analyser is used for measuring return loss. The results of measurement results are similar to simulation results. The complete chip volume of antenna is 18.3 × 23 × 1.6 mm3.

Analysis of impedance spectrum parameters in hydration process of concrete with composite admixtures

Analysis of impedance spectrum parameters in hydration process of concrete with composite admixtures

Coordinated features in jaw and neck muscle activities induced by chewing of soft and hard gum in healthy subjects.

BackgroundsJaw and neck muscles may be activated by chewing load using a hard food. However, it remains unclear how effects the gum hardness to the coordinated features in jaw and neck muscle activities during chewing performance.ObjectivesThis study was conducted to quantitatively elucidate the effects of the hardness of the gum on coordinated features in jaw and neck muscle activities using intermuscular EMG–EMG transfer function and EMG–EMG coherence function analyses in 18 healthy subjects.MethodsJaw and neck muscle activities were aggregated into the first peak frequency of the power spectrum, and power, gain, phase, and coherence parameters between jaw and neck muscle activities were examined in the first peak frequencies during soft and hard gum chewing.ResultsThe first peak frequency was not significantly different between soft and hard gum chewing. In contrast, power values of the jaw and neck muscles were significantly increased by chewing of hard gum as compared with soft gum, whereas gain, phase, and coherence were not significantly changed by gum hardness.ConclusionsThe chewing rhythm, the quantitative and temporal coordination, and the functional coordination in jaw and neck muscle activities were not changed during soft and hard gum chewing, as well as increased jaw and neck muscles activities. It is therefore concluded that the chewing rhythmicity and jaw and neck muscles coordination accompanied with the increased jaw and neck muscle activities are maintained under the condition of the chewing load using gum hardness in the healthy individuals.

Features of dyslipidemia and its influence on endothelium functional state in patients with rheumatoid arthritis and arterial hypertension

Purpose of the study. Was to identify the features of blood lipid spectrum and endothelium functional state in patients with rheumatoid arthritis (RA) and arterial hypertension (AH).
 Materials and methods. 83 patients were examined (40 with RA combined with AH, 23 with RA and 20 with AH). The blood lipid spectrum and endothelial function were studied in all patients.
 Results. The analysis of blood serum lipid parameters demonstrated that in patients with RA, regardless of the presence of AH, there was a significant increase of proatherogenic lipid profile parameters in comparison with those in healthy subjects. It was shown, that lower concentrations of high-density lipoproteins and higher atherogenic coefficient indices was a characteristic feature of the lipid profile in RA patients both with and without AH – in contrast to the same parameters of the lipid spectrum in patients with AH without RA. In the groups of patients with RA a significant increase of the brachial artery diameter at rest and decreased indices of endothelium-dependent vasodilation and endothelium-independent vasodilation were revealed. Subjects with RA in combination with AH had significantly lower indices according to the tests with both reactive hyperemia and nitroglycerin, while in patients with RA without AH, only NG-test was significantly lower.
 Conclusion. Dyslipidemia of atherogenic type and endothelial dysfunction develops at the initial stages of rheumatoid process and depends on the activity of the inflammatory process, the presence of extra-articular manifestations and rheumatoid factor seropositivity.

Protein spectrum and blood biochemical parameters in stallions with different sperm motility

The analysis of the protein spectrum of blood was carried out by electrophoresis in agarose gel in combination with the determination of biochemical parameters in 30 stallions of the Arabian breed, divided into groups according to the indicator of progressive sperm mobility. Group 1 included stallions with progressive mobility (PM) up to the 25th percentile (PM, % <53.35), group 2 - stallions with progressive mobility within the 25-75th percentile (53.35 <PM, % <65.18), and group 3 - stallions with progressive mobility above the 75th percentile (PM, %> 65.18). In the 1st group of stallions, the highest concentrations of α2-globulins and γ-globulins of blood were found. The 3rd group of stallions showed the lowest concentration of glucose and urea.

Вiковi та гендерні особливостi лiпiдного профiлю кровi хворих на гiпертонiю й iшемiчну хворобу серця

Cardiovascular disease (CVD) in the 21st century remains the leading cause of death worldwide. In Ukraine, during 2020, 365,515 ukrainians died from heart disease and da­mage of the circulatory system. It is known that hypertension (AH) is one of the most important risk factors for atherosclerosis, accelerates its development and complicates the course, and these two diseases often accompany each other. Especially common is a combination of coronary heart disease (CHD), its various forms (angina, myocardial infarction, arrhythmia) and hypertension. The aim of the study was to establish the age and sex characteristics of the lipid profile of the blood of patients with hypertension and coronary heart disease. Analyzed the statistical data of a survey of 775 people (of which 436 women and 339 men). The data on total cholesterol, triglycerides and high-density lipoprotein cholesterol content for patients with hypertension and coronary disease was analyzed in order to assess the blood lipid spectrum. Statistical analysis and data processing was performed using standard methods of variation Statistics in the Statistics 8.0 software. Changes in lipid metabolism in patients with ischemic heart disease and hypertension were studied. The performed analysis of age-related and gender-related dynamics of blood lipid spectrum parameters – total triglycerides, total cholesterol (CS), low- and high-density lipoprotein cholesterol (LDL cholesterol and HDL cholesterol), the prognostic coefficient of atherogenicity (CA). It was found that the level of total cholesterol in women in the age groups &lt;45 and 55–65 years old is higher than in similar groups in men. In age groups &gt; 65 years, gender difference in total cholesterol levels is not observed. In age group 45–55 years, there are gender-dependent differences in the value of the prognostic coefficient of atherogenicity. For women there were no age-related changes in triglyceride levels. For men there is a depen­dence of the triglyceride’s levels with the age of patients. There were no significant diffe­rences in the levels of low- and high-density lipoproteins depending on gender.

Monte Carlo calculations of neutron spectrum parameters at the JRTR NAA channels

The neutron spectra at the irradiation channels of the Jordan Research and Training Reactor have been calculated using the MCNP and McCARD codes. This work aims to validate the calculation models and tools by comparing the calculated spectrum parameters to results obtained from a recently published study which employed Cadmium Ratio measurements at three of the irradiation channels. An analysis methodology to evaluate spectrum parameters based on the calculated spectra is presented, highlighting the importance of distinguishing between alternative definitions of the thermal and epithermal fluxes when comparing data from reactor physics calculations to data from neutron activation analysis.The deviations between calculated and measured thermal-to-epithermal ratios ranged from about 3% to 12% which were considered acceptable given the identified sources of error and uncertainty in the simulation and measurement results. The simulations were also employed to study the sensitivity of the neutron spectrum parameters to changes in the reactor core and irradiation conditions, concluding that the thermal-to-epithermal ratio is significantly sensitive to the axial location of the sample within the irradiation rabbit and to the configuration of the reactor core, and less sensitive to the temperature and burnup conditions.

Tectonostratigraphic evolution of the new frontier Foram Basin and implications for hydrocarbon potential, Western Desert, Egypt

The Western Desert of Egypt is an important hydrocarbon province as it consists of many petroliferous sedimentary basins. The researchers and petroleum companies are interested in exploring the new frontier sedimentary basins and evaluating their hydrocarbon potential. Given this point of view, the current study attempts to assess the new frontier sedimentary basin in the Western Desert of Egypt, named Foram Basin (FB), using various geophysical and geological methods, including the magnetic, gravity, and seismic methods in addition to the petroleum system and basin analysis modeling. The magnetic data analysis uses various techniques, including power spectrum and source parameter image, total magnetic intensity (TMI), reduction to the pole (RTP), regional-residual separation, and tilt derivative. The used techniques in the interpretation of gravity data include Bouguer gravity, power spectrum, regional-residual separation of Bouguer gravity, tilt derivative of the Bouguer gravity and gravity inversion, and 2D gravity modeling, in addition to the tentative basement depth based on the gravity inversion and 2D gravity modeling for the nine profiles. The main results of these techniques indicate that the main structural trend is NE-SW and the depth to the basement ranges from 1.8 to 5 km comprising two depocenters.Two-thirds of the sedimentary basin fill is a Paleozoic succession and one-third is a Mesozoic-Cenozoic succession. Therefore, the FB is thought to be a Paleozoic basin. The Paleozoic-Mesozoic stratigraphic framework of the FB was classified into six seismic sequences separated by the seven seismic boundaries. The main regional structural trend of the FB is NE-SW, the same trend as that of the Paleozoic Kufra Basin in Libya. In the FB, the major structural trend in the Early Paleozoic is NE-SW, whereas it is E-W in Late Paleozoic. Moreover, in Mesozoic Jurassic time, the dominant trends are E-W and ENE-WSW, and in Middle Cretaceous is ENE-WSW and in Upper Cretaceous are E-W and NE-SW. Regarding the tectonic subsidence rate, the FB passed three tectonic phases. The first tectonic phase has a high subsidence rate that occurred in the Paleozoic, resulting in the deposition of most of the sedimentary succession. The second and third tectonic phases occurred at a relatively low subsidence rate, resulting in the deposition of Mesozoic-Cenozoic deposits. The Paleozoic Silurian Kohla source rock passed the early generation phase in the Early Eocene (50 Ma) and reached a maximum generation rate of 2.77 (mg/gTOC^my) in Late Oligocene (27 Ma) that is considered a very low rate and did not allow for oil expulsion.

Acoustic control of the strengthening of building ceramics obtained by extrusion through an ultrasonic die

Extrusion through a die, vibrating with an ultrasonic frequency is a promising method for hardening ceramic materials (bricks, tiles, pipes, etc.). We present the results of studying low-frequency acoustic spectra of cylindrical samples of face brick ceramics reinforced by extrusion and addition of fiberglass waste. Correlations between structure changes in the obtained ceramics, parameters of the acoustic spectrum of the samples, and the destructive forces upon their compression (bending) in a press were analyzed. It is shown that ultrasonic extrusion increases the destruction force of the cylinders by 1 – 7 kN (~30 %) and thus shifts the frequency of the fundamental tones of transverse and longitudinal oscillations (6 and 17 kHz) with a coefficient of ~0.1 kHz/kN. The fiberglass particles strengthen the ceramics due to the formation of a needle-like crystalline bond during firing. At the same time, an increased addition of the fiberglass particles reduces the plasticity of the batch thus resulting in formation of the microcracks, cavities and internal stresses in the samples. The occurrence of internal defects shifts the frequency of longitudinal and transverse vibrations to a different extend, which can be used as an indicator of the defects present in the samples and provide the possible of their objective sorting and rejection. The vibration relaxation time (about 0.1 sec) does not change significantly under the described strengthening effects and being characterized by a wide scatter in each series of the samples cannot be considered an informative parameter. Thus, the effectiveness of the presented combined method of ceramics hardening can be accurately tested by the shift in the frequencies of longitudinal and transverse free vibrations of cylindrical specimens. The presented approach facilitates the process of developing new ceramic compositions and extrusion technology in conditions of depletion of sources of high-quality clay raw materials.

DNA methylation subtypes for ovarian cancer prognosis.

Ovarian cancer is one of three major malignancies of the female reproductive system. DNA methylation (MET) is closely related to ovarian cancer occurrence and development, and as such, elucidation of effective MET subtype markers may guide individualized treatment and improve ovarian cancer prognosis. To identify potential markers, we downloaded a total of 571 ovarian cancer MET samples from The Cancer Genome Atlas (TCGA), and established a Cox proportional hazards model using the MET spectrum and clinical pathological parameters. A total of 250 prognosis-related MET loci were obtained by Cox regression, and six molecular subtypes were screened by consensus clustering of CpG loci with a significant difference in both univariate and multivariate analyses. There was a remarkable MET difference between most subtypes. Cluster 2 had the highest MET level and demonstrated the best prognosis, while Clusters 4 and 5 had MET levels significantly lower than those of the other subtypes and demonstrated very poor prognosis. All Cluster 5 samples were at a high grade, while the percentage of stage IV samples in Cluster 4 was greater than in the other subtypes. We obtained five CpG loci using a coexpression network: cg27625732, cg00431050, cg22197830, cg03152385, and cg22809047. Our cluster analysis showed that prognosis in patients with hypomethylation was significantly worse than in patients with hypermethylation. These MET molecular subtypes can be used not only to evaluate ovarian cancer prognosis, but also to fully distinguish the tumor stage and histological grade in patients with ovarian cancer.

Study on the time-varying characteristics of AC local arc over the contaminated insulation surface

From laboratory experiments it was shown that the flashover voltage of the wet contaminated insulator was significantly influenced by the parameters of the local arc. An integrated optical and electrical diagnostic platform was designed in this paper, which was used to acquire the emission spectrum and electrical parameters of the AC local arc over the wet contaminated surface. The analysis of thermodynamic and electric results showed that AC local arc had a “static time-varying” feature. Hence, a new characterization method of volt–ampere characteristics of the AC local arc was proposed, and a time constant was introduced to describe the time required for the AC local arc to reach the stable state from the beginning. The relationship between the voltage gradient of the AC local arc and the leakage current amplitude was obtained for flashover voltage calculation. Special attention was also paid to the influence of environmental factors, such as air pressure and ambient temperature, on the arc characteristic. This work can enrich the investigation of the parameters of the local arc over the wet contaminated insulation surface and may provide useful parameters for flashover voltage calculation of insulators in service.

MULTIFRACTAL ANALYSIS OF THE GOLD MARKET

In this paper, we investigate the efficiency of gold market through time evolution of multifractal spectrum parameters (position of maximum, width and asymmetry), by applying multifractal detrended fluctuation analysis in sliding windows of 4, 10 and 20 years. We find that geopolitical and economic events can decrease market efficiency by inducing changes in gold price dynamics toward increased persistency and stronger multifractality with dominance of large fluctuations. For all analyzed geopolitical events and for all windows sizes, we found stronger multifractality of underlying stochastic process, indicated by the increase in the spectrum width [Formula: see text].

Intelligent Cognitive Radio Ad-Hoc Network: Planning, Learning and Dynamic Configuration

Cognitive radio (CR) is an adaptive radio technology that can automatically detect available channels in a wireless spectrum and change transmission parameters to improve the radio operating behavior. A CR ad-hoc network (CRAHN) should be able to coexist with primary user (PU) systems and other CR secondary systems without causing harmful interference to licensed PUs as well as dynamically configure autonomous and decentralized networks. Therefore, an intelligent system structure is required for efficient spectrum use. In this paper, we present a learning-based distributed autonomous CRAHN network system model for network planning, learning, and dynamic configuration. Based on the system model, we propose machine learning-based optimization algorithms for spectrum sensing, cluster-based ad-hoc network configuration, and context-aware signal classification. Using the sensing engine and the cognitive engine, the surrounding spectrum usage and the neighbor network operation status can be analyzed. The proposed policy engine can create network operation policies for the dynamically changing surrounding wireless environment, detect policy conflicts, and infer the optimal policy for the current situation. The decision engine finally determines and configures the optimal CRAHN configuration parameters through cooperation with a learning engine, in which we implement the proposed machine-learning algorithms. The simulation results show that the proposed machine-learning CRAHN algorithms can construct CR cluster networks that have a long network lifetime and high spectrum utility. Additionally, with high signal context recognition performance, we can ensure coexistence with neighboring systems.