Response Characteristic of Cable Stayed Bridges under Static Loading and Due to the Earthquakes in Longitudinal Direction

This paper presents the dynamic (earthquake response) analysis of cable stayed bridges under different types of static loading and due to longitudinal directions of earthquake base excitations. The deck and the tower of the bridge were idealized by discrete element idealization scheme (space frame element) with warping considered as a seventh degree of freedom. For comparison purposes, the discrete element with six degrees of freedom (warping neglected) were also used to model the structure under investigation. The cables were modelled by the nonlinear truss elements. It was found that the warping becomes of significant influence on the behaviour of the bridge deck only if the deck is acted upon by loading that is coupled with initial torsional moment

A new compact wideband MIMO antenna – the double-sided tapered self-grounded monopole array

We present a new compact wideband multiple input multiple output (MIMO) antenna—the double-sided 4-port arm-tapered self-grounded monopole array, briefly referred to as the butterfly antenna, in the communication. The antenna is very compact with low correlation between ports and high diversity gain. The genetic algorithm optimization scheme has been employed in the design. Simulation results have been verified against measurements. The measured reflection coefficients at all ports are below -7 dB over 0.5–9 GHz and below -4.5 dB over 0.4–0.5 GHz and 9–15 GHz. The measured correlation coefficients are below 0.4 over 0.4–15 GHz and lower than 0.1 in most of the frequency band. This new MIMO antenna is developed as a transmit antenna in reverberation chambers, and we believe that it will find more applications in other systems, such as micro base station antennas in wireless communication systems

Impact of family structure and sociodemographic characteristics on parents headed families in Ramadi City, Iraq

Background: Several factors in the family profile contribute significantly to determining the effective policy when heading the family. This study aims to evaluate the sociodemographic and economic burdens on parents-headed families in Ramadi City, west of Iraq. Methods: A prospective cross-sectional household-based survey was conducted from 1st to 28th February 2019 among Iraqi people residents in Ramadi city, Anbar province. A multistage sampling technique was recruited to identify the eligible sample. A semi-structured questionnaire was used to interview (face-to-face) the respondents. Data from 267 households have undergone univariate and bivariate analyses. Multiple logistic regression, odds ratio (OR), and confidence intervals (CIs) were estimated to explore the predicting variables. The statistically significant is considered at less than 0.05. Results: The mean age of respondents was 43.88 (± 12.1) years (range: 25 to 69 years). Out of the total surveyed people, 52.8% were young (less than 44 years), male-headed families (59.6%), low educated level (65.5%), unemployed (52.4%), married (67.4%) and headed big families of seven members and above (43.1%). History of chronic diseases and smoking habits was positive among 46.4% and 45.7% of respondents, respectively. Findings of the binary logistic regressions showed that history of smoking (OR = 7.201, 95% CI: 3.254 to15.936), families of 7 members and above (OR = 6.239, 95% CI: 2.938 to 13.250), unhappy (OR = 5.237, 95% CI: 2.140 to 12.818), aged 44 years and above (OR = 3.518, 95% CI: 1.581 to 7.829), being single (unmarried, divorced, widow) (OR = 2.697, 95% CI: 1.230 to 5.914), and had a monthly income of less than USD400 (OR = 2.333, 95% CI: 1.112 to 4.859) are significantly associated with female-headed family. Conclusion: Priority must be given to some elements such as genetic, physical differences, biopsychosocial factors, and the economic situation when discussing parents' behavior in heading the family

Kinetic and equilibrium study of graphene and copper oxides modified nanocomposites for metal ions adsorption from binary metal aqueous solution

Presently, the main cause of pollution of natural water resources is heavy metal ions. The removal of metal ions such as nickel (Ni2+) and cadmium (Cd2+) has been given considerable attention due to their health and environmental risks. In this regard, for wastewater treatment containing heavy metal ions, graphene oxide (GO) nanocomposites with metal oxide nanoparticles (NPs) attained significant importance. In this study, graphene oxide stacked with copper oxide nanocomposites (GO/CuO-NCs) were synthesized and characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and atomic force microscopy (AFM) analytical procedures. The prepared GO/CuO-NCs were applied for the removal of Ni2+ and Cd2+ ions from a binary metal ion system in batch and continuous experiments. The obtained results revealed that GO/CuO-NCs exhibited the highest removal efficiencies of Ni2+ (89.60% ± 2.12%) and Cd2+ (97.10% ± 1.91%) at the optimum values of pH: 8, dose: 0.25 g, contact time: 60 min, and at 50 ppm initial metal ion concentration in a batch study. However, 4 mL/min flow rate, 50 ppm initial concentration, and 2 cm bed height were proved to be the suitable conditions for metal ion adsorption in the column study. The kinetic adsorption data exhibited the best fitting with the pseudo-second-order model. The adsorption isotherm provided the best-fitting data in the Langmuir isotherm model. This study suggested that the GO/CuO nanocomposites have proved to be efficient adsorbents for Ni2+ and Cd2+ ions from a binary metal system

General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multicentre observational study

There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients’ (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16–22) and failed intubation in 1 in 312 (95%CI 1 in 169–667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%)

General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multi-centre observational study

There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients' (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16-22) and failed intubation in 1 in 312 (95%CI 1 in 169-667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%)

Scan properties of slot-fed dielectric resonator antenna arrays for 5G wireless communications

\u3cp\u3eAn 8×8 array antenna based on dielectric resonator antennas (DRA) fed by a slot antennas is proposed as a base-station antenna for millimeter-wave 5G wireless communications. The total radiation efficiency is modeled as a function of frequency and beam steering. It turns out that the total radiation efficiency is higher than 80% over the frequency band from 26 GHz to 34 GHz and for scan angles up to 60 degrees along the H-plane. The DRA can perform beam steering over wide bandwidth with a scan-loss comparable to the array factor of an ideal source. In addition, The DRA array is 20% smaller in size compared to conventional half-spaced antenna arrays.\u3c/p\u3

Fracture Toughness and Hardness studying for Polymer-Ceramic Composite

A particulate composite material was prepared by adding the Titanium dioxide (TiO2) with a particle size of (75-150) µm to Epoxy resin at weight percentage of (10%,20%,30%,40%,50%).The following some mechanical properties were studied,fracture toughness, hardness.casting preparation methods were used in this study includes preparing plate of matrix and composites. specimens were prepared according to ASTM for the Mechanical properties tests. After that Another samples were heat treated for three and six hour at 65C?. Fracture toughness (Kic) represent for stress intensity factor results were showed that the curve of three hours aging increases in fracture toughness (Kic) for composites but for six hours aging increases fracture toughness (Kic) for polymer matrix. Hardness tests was showed that hardness results increased with the increase in weight fraction while a samples that not treated thermally have higher hardness than the samples for treated thermally. Finally, fracture surfaces were showed morphology failure surfaces by using an optical Microscope

Reflector synthesis for wide-scanning focal plane arrays

A new complex offset double-reflector configuration for a wideband focal plane array (FPA) is presented which is optimized for Ka-band applications with a scan range of ±20° in the azimuth plane. This configuration is obtained by using a mathematical framework based on geometrical optics which allow us to optimize complex double-reflector FPAs with limited computational effort. The proposed reflector configuration maximizes the number of simultaneously active array elements of the phased-array feed and minimizes the required total number of array elements for this wide scan range. To realize an aperture efficiency of at least 80% at 30 GHz, our concept allows half of the antenna elements in the array to be active during scanning for a scan range of ±10° and at least a quarter of the array elements to be active for a scan range of ±20°. This is a major improvement as compared to the scanning capabilities of focal-plane arrays based on conventional single- and double-parabolic reflector configurations. In addition, the FPA configuration has been optimized for wideband optical true-time-delay beamforming which requires a linear phase distribution along the array elements. We obtained a phase linearity with rms error of 2.81° at 30 GHz. The experiments from the realized prototype demonstrate a good agreement between simulation and measurements and fully prove the required scanning performance over a ±20° scan range. The prototype demonstrates a high directivity up to 46 dBi at 30 GHz and 48 dBi at 40 GHz and reflector efficiency up to 83% at 30 GHz and 77% at 40 GHz

The double-sided 4-port bow-tie antenna : a new compact wideband MIMO antenna

We present a new compact ultra-wideband 4-port antenna for use in MIMO systems, such as in reverberation chambers for OTA measurements. The new antenna is based on the self-grounded bow-tie antenna with a very compact size. The design was done through an optimization by employing the genetic algorithm in order to obtain low reflection coefficient and mutual coupling between ports. The designed antenna has an embedded radiation efficiency higher than -0.35 dB, reflection coefficient below -7 dB, mutual coupling between ports below - 12.5 dB (in most frequencies below -20 dB), over a frequency range of 0.4–15 GHz