Design of a Compact Dual-Band Microstrip Antenna Enabled by Complementary Split Ring Resonators for X-Band Applications

In this paper, a design of highly effective dual-band microstrip antenna for X-band applications is developed. Dual-band response is obtained by etching four rectangular split ring resonator (RSRR) unit cells within the radiating element of a conventional patch initially designed to operate at 10 GHz. The proposed antenna is constructed on low lossy RT/duroid 5880 (ϵr = 2.2, tan δ = 0.0009) substrate of 20x20x1.575 mm3 total area. The antenna is tuned to operate at two resonant frequencies within 8 to 12 GHz depending on the geometric specifications of the RSRR's. A parametric study of different numbers of unit cells etched on the radiating element is investigated and discussed comprehensively through this study. Realized gain of about 6.2 and 6.8 dB at 8.8 and 10 GHz are attained. Consistent results are obtained between the measurements and simulation results using 3D full-wave FEM-base simulator

Bioadsorption of Pb

Herein, the efficiency of Eucalyptus camaldulensis leaves as biosorbent for lead and copper was investigated. The particle size distribution was determined by Granulometric analysis and the functional groups were identified by FT-IR spectroscopy. The effects of contact time, pH and initial metal ions concentration were investigated. The experimental kinetic data were well fitted by the pseudo-second order kinetic model and Langmuir isotherm with a maximum adsorption capacity up to 71 mg g-1 and 37 mg g-1 for Cu2+ and Pb2+ respectively. The selectivity was examined in a binary ions solution where the adsorbent showed preference for lead over copper

The hypertension cascade of care in the midst of conflict: the case of the Gaza Strip

Although hypertension constitutes a substantial burden in conflict-affected areas, little is known about its prevalence, control, and management in Gaza. This study aims to estimate the prevalence and correlates of hypertension, its diagnosis and control among adults in Gaza. We conducted a representative, cross-sectional, anonymous, household survey of 4576 persons older than 40 years in Gaza in mid-2020. Data were collected through face-to-face interviews, anthropometric, and blood pressure measurements. Hypertension was defined in anyone with an average systolic blood pressure ≥140 mmHg or average diastolic blood pressure ≥90 mmHg from two consecutive readings or a hypertension diagnosis. The mean age of participants was 56.9 ± 10.5 years, 54.0% were female and 68.5% were Palestinian refugees. The prevalence of hypertension was 56.5%, of whom 71.5% had been diagnosed. Hypertension was significantly higher among older participants, refugees, ex-smokers, those who were overweight or obese, and had other co-morbidities including mental illnesses. Two-thirds (68.3%) of those with hypertension were on treatment with one in three (35.6%) having their hypertension controlled. Having controlled hypertension was significantly higher in females, those receiving all medications for high blood pressure and those who never or rarely added salt to food. Investing in comprehensive but cost-effective initiatives that strengthen the prevention, early detection and timely treatment of hypertension in conflict settings is critical. It is essential to better understand the underlying barriers behind the lack of control and develop multi-sectoral programs to address these barriers

Avoidance of multicast incapable branching nodes for multicast routing in WDM networks

In this articlewestudy themulticast routing problem in all-opticalWDMnetworks under the spare light splitting constraint. To implement a multicast session, several light-trees may have to be used due to the limited fanouts of network nodes. Although many multicast routing algorithms have been proposed in order to reduce the total number of wavelength channels used (total cost) for a multicast session, the maximum number of wavelengths required in one fiber link (link stress) and the end-to-end delay are two parameters which are not always taken into consideration. It is known that the shortest path tree (SPT) results in the optimal end-to-end delay, but it can not be employed directly for multicast routing in sparse light splitting WDM networks. Hence, we propose a novel wavelength routing algorithm which tries to avoid the multicast incapable branching nodes (MIBs, branching nodes without splitting capability) in the shortest-path-based multicast tree to diminish the link stress. Good parts of the shortest-path-tree are retained by the algorithm to reduce the end-to-end delay. The algorithm consists of tree steps: (1) aDijkstraPro algorithmwith priority assignment and node adoption is introduced to produce a SPT with up to 38% fewer MIB nodes in the NSF topology and 46% fewerMIB nodes in the USA Longhaul topology, (2) critical articulation and deepest branch heuristics are used to process the MIB nodes, (3) a distance-based light-tree reconnection algorithm is proposed to create the multicast light-trees. Extensive simulations demonstrate the algorithm's efficiency in terms of link stress and end-to-end delay

Quasi-energy-independent solar neutrino transitions

Current solar, atmospheric, and reactor neutrino data still allow oscillation scenarios where the squared mass differences are all close to 10^-3 eV^2, rather than being hierarchically separated. For solar neutrinos, this situation (realized in the upper part of the so-called large-mixing angle solution) implies adiabatic transitions which depend weakly on the neutrino energy and on the matter density, as well as on the ``atmospheric'' squared mass difference. In such a regime of ``quasi-energy-independent'' (QEI) transitions, intermediate between the more familiar ``Mikheyev-Smirnov-Wolfenstein'' (MSW) and energy-independent (EI) regimes, we first perform analytical calculations of the solar nu_e survival probability at first order in the matter density, beyond the usual hierarchical approximations. We then provide accurate, generalized expressions for the solar neutrino mixing angles in matter, which reduce to those valid in the MSW, QEI and EI regimes in appropriate limits. Finally, a representative QEI scenario is discussed in some detail.Comment: Title changed; text and acronyms revised; results unchanged. To appear in PR