Direction finding in sensors model based automatic modulation classification

In this paper, the RSSI testing as well the Angle of Arrival (AoA) have been examined for position prediction also produce the front specified composition of the possibility distribution of the location of a sensor node. "Multiple Signal Classification" (MUSIC) defined as a popular "Eigen" construction approach with large declaration, which broadly utilized for predicting the total of waveforms, as well their corners of arrival. In this research an examination of the ability to development of part of key specifications of the "MUSIC" technique has been presented, which might improve the response of the prediction operation. The outcomes of the simulation of this approach point out that the position of the sensor node may be evaluated in a little time period values as well that the condition of the explanation is competitive beside last techniques

A novel delay dictionary design for compressive sensing-based time varying channel estimation in OFDM systems

Compressive sensing (CS) is a new attractive technique adopted for Linear Time Varying channel estimation. orthogonal frequency division multiplexing (OFDM) was proposed to be used in 4G and 5G which supports high data rate requirements. Different pilot aided channel estimation techniques were proposed to better track the channel conditions, which consumes bandwidth, thus, considerable data rate reduced. In order to estimate the channel with minimum number of pilots, compressive sensing CS was proposed to efficiently estimate the channel variations. In this paper, a novel delay dictionary-based CS was designed and simulated to estimate the linear time varying (LTV) channel. The proposed dictionary shows the suitability of estimating the channel impulse response (CIR) with low to moderate Doppler frequency shifts with acceptable bit error rate (BER) performance

Performance evaluation of high mobility OFDM channel estimation techniques

In wireless communication, Orthogonal Frequency Division Multiplexing (OFDM) has been adopted due to its robustness to multipath fading and high data rate transmissions. At the other hand, the performance of OFDM systems severely degraded due to multi-path fading and Doppler frequency shifts in mobile systems, which causes inter-carrier-interference (ICI). Thus, Estimation of channel parameters is required at the receiver using a pre designed estimator where pilot tones are inserted in each OFDM symbol. In this paper, a random pilot data are generated and inserted in each OFDM symbol at equally spaced locations. The performance test of Least Square (LS) and Linear Minimum Mean Square (LMMSE) estimation methods are proposed with Discrete Fourier Transform (DFT) based on both LS and LMMSE, where different ITU channel models are considered in order to compare their performance for data transmission in high mobile systems with different Doppler frequencies exceeds 200 Hz and minimal number of pilots

Disentangling conical intersection and coherent molecular dynamics in methyl bromide with attosecond transient absorption spectroscopy

Attosecond probing of core-level electronic transitions provides a sensitive tool for studying valence molecular dynamics with atomic, state, and charge specificity. In this report, we employ attosecond transient absorption spectroscopy to follow the valence dynamics of strong-field initiated processes in methyl bromide. By probing the 3d core-to-valence transition, we resolve the strong field excitation and ensuing fragmentation of the neutral σ* excited states of methyl bromide. The results provide a clear signature of the non-adiabatic passage of the excited state wavepacket through a conical intersection. We additionally observe competing, strong field initiated processes arising in both the ground state and ionized molecule corresponding to vibrational and spin-orbit motion, respectively. The demonstrated ability to resolve simultaneous dynamics with few-femtosecond resolution presents a clear path forward in the implementation of attosecond XUV spectroscopy as a general tool for probing competing and complex molecular phenomena with unmatched temporal resolution

Assessment of Thyroid Function in Infertile Iraqi Females

Infertility is one of the medical, social and psychological burdens in Iraqi society. Thyroid dysfunction can lead to menstrual disturbance, anovulatory cycle and decreased fertility. The study was designed to evaluate the role of thyroid disorders in infertility with emphasis on autoimmunity by Measuring T3, T4, TSH, & anti Thyroid peroxidase antibody in infertile females comparing the results with matching fertile controls. The study was conducted during the period from March 2015 to September 2015 at Karbala Maternity Hospital, infertility unit, and some private clinics. This study included a total number of 143 women in the reproductive age; ranging between (15- 43) years; divided into: The patients group included 92 infertile females; while controls were 51fertile females. The following parameters were measured for all study groups: T3, T4, TSH, &anti-TPO using ELISA device. The results showed that there were 60.8% of patients with primary infertility (n =56) while 38.2% were with secondary infertility (n= 36). There was a significant difference in T3, and Anti-TPO between patients and controls being higher in patients; (p-value <0.05). In addition; Anti-TPO level was significantly higher in secondary infertile patients compared to primary infertile patients. In conclusion; Thyroid disorders are closely related to infertility in Iraqi females; and Anti-TPO may be used as a biochemical indicator of subclinical thyroid disorders and may help in assessment of thyroid function as a cause of infertility whether primary or secondary. Keywords: Infertility, Thyroid disease, T3, T4, Anti-TP

Modelling of Collision in the Plasma Sheath and the Cathode Erosion of Electrical Arc

In order to improve many industrial applications of the plasma sheath and the cathode erosion of electrical arc, the prime objective of this paper is to treat the modelling and simulation of the effects of ions collisionality on the plasma sheath and to determine the collisional dependence of the sheath width and the ion impact energy on the wall using the Runge-Kutta Routrine on the presence or the absence of the term source in the continuity equation . Then , to explain the dependence of the measured erosion rate of the cathode by considering the cathode spot heat balance equation coupled with equation obtained from the sheath and taking into account the physical phenomena such as ion and electron fluxes, radiation, thermal conductivity and evaporation.In order to improve many industrial applications of the plasma sheath and the cathode erosion of electrical arc, the prime objective of this paper is to treat the modelling and simulation of the effects of ions collisionality on the plasma sheath and to determine the collisional dependence of the sheath width and the ion impact energy on the wall using the Runge-Kutta Routrine on the presence or the absence of the term source in the continuity equation . Then , to explain the dependence of the measured erosion rate of the cathode by considering the cathode spot heat balance equation coupled with equation obtained from the sheath and taking into account the physical phenomena such as ion and electron fluxes, radiation, thermal conductivity and evaporation

Structural study, thermal and physical properties of K2O-CaO-P2O5 phosphate glasses

Glasses of 50P2O5-xCaO-(50-x)K2O  (x= 0, 10, 20, 30, and 40 mol %) compositions were synthesized using the melt-quench procedure. The amorphous character of the prepared material was confirmed by X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). Fourier Transform Infra-Red (FT-IR) and Raman spectroscopy are also carried out in order to determine the structural network evolution of the glassy materials with the composition. Besides, the physical properties of the glassy phosphate system were examined such as density and molar volume. The results showed that the increase of CaO content in phosphate glasses diminish the molar volume and raise the density and transition temperature. FTIR and Raman spectroscopy analysis demonstrate the formation of P-O-Ca bonds that substitute P-O-K bonds and the depolymerization of the phosphate chains. The formation of P-O-Ca bonds is in accordance with variations of glass transition temperature, (Tg), molar volume (Vm) and density (ρ). The former bonds are the origin of the partial glass-forming ability of Ca2+. In addition, an analysis of the surface morphology features was conducted using a Scanning Electron Microscopy (SEM) technique

Virtual single-photon transition interrupted: time-gated optical gain and loss

The response of matter to an optical excitation consists essentially of absorption and emission. Traditional spectroscopy accesses the frequency-resolved and time-integrated response, while the temporal evolution stays concealed. However, we will demonstrate here that the temporal evolution of a virtual single-photon transition can be mapped out by a second pulsed electromagnetic field. The resulting optical signal shows previously unexpected optical gain and loss, which can be gated and controlled via the relative delay of the electromagnetic fields. The model presented here can be applied to any system that assumes a two-level character through near-resonant optical dipole excitation, whether they are of atomic, molecular or even solid-state nature. These theoretical observations are in excellent qualitative agreement with our transient absorption spectroscopy study in helium. The presented results can act as starting point for a new scheme for creating optical gain, which is a prerequisite for the operation of lasers. It may be possible to open the doors to spectral regions, which were difficult to access until now, e.g. in the extreme ultraviolet.Comment: 15 pages, 4 figure

Development of Hot Equal Channel Angular Processing (ECAP) consolidation technique in the production of Boron Carbide(B4C)-Reinforced Aluminium Chip (AA6061)-based composite

The production of metal matrix composites (MMCs) through recycled materials is a cost-saving process. However, the improvement of the mechanical and physical properties is another challenge to be concerned. In this study, recycled aluminium 6061 (AA6061) chips reinforced with different volumetric fractions of boron carbide (B4C) were produced through hot equal channel angular processing (ECAP). Response surface methodology (RSM) was carried out to investigate the dependent response (compressive strength) with independent parameters such as different volumetric fractions (5-15%) of added contents of B4C and preheating temperature (450 – 550°C). Also, the number of passes were examined to check the effect on the mechanical and physical properties of the developed recycled AA6061/B4C composite. The results show that maximum compressive strength and hardness of recycled AA6061/B4C were 59.2 MPa and 69 HV respectively at 5% of B4C contents. Likewise, the density and number of pores increased, which were confirmed through scanning electron microscope (SEM) and atomic force microscopes (AFM) analysis. However, the number of passes enhanced the mechanical and physical properties of the recycled AA6061/B4C composite. Therefore, the maximum compressive strength and hardness achieved were 158 MPa and 74.95 HV for the 4th pass. Moreover, the physical properties of recycled AA6061/B4C composite become denser of 2.62 g/cm3 at the 1st pass and 2.67 g/cm3 for the 4th pass. Thus, it can be concluded that the B4C volumetric fraction and number of passes have a significant effect on recycled AA6061 chips