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•A wideband W-shaped slot-loaded solid U-shaped rectangular patch antenna is presented.•A low-cost 1.6 mm-thick FR4 microwave substrate is used.•Achieved a wide operating band of 1.54 to 2.75 GHz (56.41%) with good gain, and efficiency.•A small group delay of lower than 1.5 ns and a high-fidelity factor above 80% is achieved.•A low SAR value of 0.26 W/kg (for 10g SAR) is achieved over the operating band.•A near field directivity (NFD) >77% is achieved.•Antenna sensitivity in a realistic head model is carried out using an array and found suitable for the malignant tissue detection system.

To examine the impact of tin (Sn) element on the microstructure and properties of biomedical β-type Ti-Ni shape memory-based alloys, porous Ti-51 at.%Ni-xSn (x= 0, 0.225, 0.453, and 1.375) alloys were investigated. The microstructure of the Sn-modified and unmodified alloys showed two main regions, viz. Ti- and Ni-rich regions, corresponding to Ti2Ni and TiNi3phases, plus some intermetallic compounds (Ti3Sn and Sn5Ti6) as Sn was added. The transformation temperature curves of the Ti-Ni and Ti-Ni-xSn samples displayed a multistep phase transformation (β19´ → R → β2) during the heating process. Addition of 0.225 at.% Sn to the Ti-51 at.%Ni sample improved its fracture strength, strain and shape memory behavior, polarization resistance, and antibacterial properties. On the other hand, the antibacterial properties further increased when the Sn content was increased to 0.453 and 1.375 at.%, although the mechanical and shape memory properties were degraded.

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•A CPW-fed planar monopole antenna is proposed for portable communication devices.•A thick less expansive substrate material with high dielectric constant is used.•Possesses a very small size of 24.5 × 20 mm.•Achieved the UWB performances (3.05 – 11.25 GHz) with good gain, and efficiency.•Suitable for WiMAX, WLAN, LTE, UWB, and 5G sub-6 GHz communication applications.

In the current study, a novel Zeonex based porous core photonic crystal fiber (PC-PCF) is presented for polarization-maintaining and dispersion flattened in the terahertz (THz) region. For minimizing the Effective Material Loss (EML), an array of three rectangular and six triangular air holes are surrounded by hexagonal-shaped cladding. Finite Element Method (FEM) is employed through Comsol V5.3a software to design and examine the essential features of the proposed porous core fiber which revealed that it has an extremely small EML of 0.04 cm−1at 1.2 THz and has almost zero flattened dispersion of 0.8 ± 0.08 ps/THz/cm in 1.0–1.4 THz frequency spectrum. Moreover, the optimum designing parameters offer an extremely high value of birefringence (0.043 at 1.2 THz). Besides, other major features notably bending loss, effective area, and confinement loss are also found to be precise and relatively low. For effective, adaptable and fitting transmission characteristics, this type of design would lay the foundations for broadband THz radiation wide variety of usage in the THz regime.

Ti–Nb, Ti–Nb–Sn, Ti–Nb–Sn–xCe and Ti–Nb–Sn–xSb shape memory alloys (SMAs) fabricated by powder metallurgy method and sintered via microwave sintering (MWS) technique, where x= 0, 0.2 and 0.4 wt% of Ce and Sb. The influence of Sn, Ce, and Sb on Ti–Nb alloy due to the porosity reduction, microstructure, mechanical properties, elastic modulus and corrosion behavior was investigated. The microstructure exhibits β, αas main phases and small intensities of α″ phase, this microstructure shows needles-like and dendritic-like morphologies. Adding Ce and Sb to Ti–Nb–0.5Sn refine the grains size especially at the percentage of 0.4%. Ti–Nb based SMAs before and after adding Sn, Ce, and Sb exhibit superior properties, Ti–Nb–Sn–0.4Ce SMA exhibit the best mechanical properties and corrosion behavior due to high fracture strength of 900 MPa, good strain recovery of E2 = 75%, excellent corrosion rate of 111 × 10–6mm/year and high corrosion resistance of 5588 kΩ. These SMAs exhibited low elastic modulus in the range of 16 to 21 GPa which makes them suitable for biomedical implants.

In this work, the influence of microwave sintering time and temperature on the microstructure characterisation, and thermal and mechanical behaviours of Ti–30Ta were investigated. The relative densities of Ti–30Ta samples were in the range of 65–72% and as the sintering times/temperatures increased, the relative density decreased. The pore size averages were in the range of 6–17 µm with different sintering parameters, for instance the smallest pore size of 6.8 µm was observed after being sintered at 900 ℃ for 30 min (Ta2). Two morphologies of plate-like (P) and needle-like (N) structures were observed, as well as two regions – dark region (Ti-rich region) and bright region (Ta-rich region), also two phases – β and α. The DSC results revealed that the Msto Mftransformation range was 98.86 to 80.5 ℃, respectively, while the range of Asto Aftransformation was about −22.35 to 92 ℃, respectively. The maximum fracture strength and its strain were acquired in the sintered sample of 900 ℃ for 30 min. The total strain recovery (ɛT) was improved linearly as the sintering temperature increased, correspondingly, the best ɛTwas implied in Ti–Ta shape memory alloys after being sintered at 1000 ℃ for 30 min (Ta4).

This article addresses the ecological, socio-economic and political constraints facing pastoralists' water access rights in Blue Nile State, south-eastern Sudan, over the last five decades. It examines the main constraints on pastoralists' access to water and looks at such issues as climate change, increasing human population, the expansion of agriculture, the expansion of Dinder National Park, civil war and the new international border created after the secession of South Sudan in 2011.

The anomalies in fish fall into two main categories: severe ones that affect their fitness, and less severe ones that don’t impact survival and may occur as a result of various external and internal factors. Abnormally developed fish can be used as indicators of water pollution because of their high incidence in polluted areas. The objectives of the present study were to report and describe for the first time severe cases of scoliosis and fin deformities in fish from Saudi Arabia. Morphological anomalies, in general, can reduce the weight of fish and, more importantly, impact the value per kg sold. Therefore, the fisheries industries should conduct research into the various etiological causes of the deformities before any management policy can be chosen.

Specimens of spinycheek grouper Epinephelus diacanthus(Teleostei: Epinephelidae) and the Mozambique tilapia, Oreochromis mossambicus(Teleostei: Cichlidae) were reported in this study to show the case of head deformity in individuals of Epinephelus diacanthuscollected from waters in the vicinity of Jubail City, Saudi Arabia. Individuals of Oreochromis mossambicuswere obtained from the fish market, which are originally collected and brought from the neighbouring Sultanate of Oman have shown pugheadness deformity. The specimen of Epinephelus diacanthusshown to have short neurocranium, absence of upper jaw and normal lower jaw, with the mouth nearly closed. The specimen of Oreochromis mossambicusshowed short neurocranium and a normal upward directed upper and lower jaws. The mouth was nearly closed, with the two sides being stuck, which means that the deformity has a significant effect on the mechanism of mouth operation. The case of O. mossambicusis considered more severe than the case of E. diacanthusin spite of missing few bony elements. The possible causes for such deformities are discussed. The first new documented record of Epinephelus diacanthusin the Arabian Gulf waters is reported based on one specimen with total length 420 mm, which has been collected by gill net on the coast of Jubail City. Morphometric and meristic data are provided.

The effect of time and temperature on the microwave sintering of 51(at.%)Ni–Ti shape memory alloys (SMAs) was investigated in the current research. Furthermore, the microstructure, mechanical properties, and bio-corrosion properties were analyzed based on the sintering conditions. The results revealed that the sintering condition of 700 °C for 15 min produced a part with coherent surface survey that does not exhibit gross defects. Increasing the sintering time and temperature created defects on the outer surface, while reducing the temperature to 550 °C severely affected the mechanical properties. The microstructure of these samples showed two regions of Ni-rich region and Ti-rich region between them Ti2Ni, NiTi, and Ni3Ti phases. The differential scanning calorimeter (DSC) curves of Ni–Ti samples exhibited a multi-step phase transformation B19′–R–B2 during heating and cooling. An increase in the sintering temperature from 550 to 700 °C was found to increase the fracture strength significantly and decreased the fracture strain slightly. Reducing the sintering temperature from 700 to 550 °C severely affected the corrosion behaviors of 51%Ni–Ti SMAs. This research aims to select the optimum parameters to produce Ni–Ti alloys with desired microstructure, mechanical properties, and corrosion behaviors for biomedical applications.

Porous Ti-23%Nb (mole fraction) shape memory alloys (SMAs) were prepared successfully by microwave sintering with excellent outer finishing (without space holder). The effects of microwave-sintering on the microstructure, phase composition, phase-transformation temperature, mechanical properties and shape-memory effect were investigated. The results show that the density and size of porosity vary based on the sintering time and temperature, in which the smallest size and the most uniform pore shape are exhibited with Ti-23%Nb SMA after being sintered at 900 °C for 30 min. The microstructure of porous Ti-Nb SMA consists of predominant α″, α, and βphases in needle-like and plate-like morphologies, and their volume fractions vary based on the sintering time and temperature. The βphase represents the largest phase due to the higher content of βstabilizer element with little intensities of αand α″phases. The highest ultimate strength and its strain are indicated for the sample sintered at 900 °C for 30 min, while the best superelasticity is for the sample sintered at 1200 °C for 30 min. The low-elastic modulus enables these alloys to avoid the problem of “stress shielding”. Therefore, microwave heating can be employed to sinter Ti-alloys for biomedical applications and improve the mechanical properties of these alloys.

Elemental titanium (Ti) and nickel (Ni) powders were consolidated by spark plasma sintering (SPS) to fabricate Ti–51%Ni (mole fraction) shape-memory alloys (SMAs). The objective of this study is to enhance the superelasticity of SPS produced Ti–Ni alloy using free forging as a secondary process. Products from two processes (with and without free forging) were compared in terms of microstructure, transformation temperature and superelasticity. The results showed that, free forging effectively improved the tensile and shape-memory properties. Ductility increased from 6.8% to 9.2% after forging. The maximum strain during superelasticity increased from 5% to 7.5% and the strain recovery rate increased from 72% to 92%. The microstructure of produced Ti–51%Ni SMA consists of the cubic austenite (B2) matrix, monoclinic martensite (B19′), secondary phases (Ti3Ni4, Ti2Ni and TiNi3) and oxides (Ti4Ni2O and Ti3O5). There was a shift towards higher temperatures in the martensitic transformation of free forged specimen (aged at 500 °C) due to the decrease in Ni content of B2 matrix. This is related to the presence of Ti3Ni4precipitates, which were observed using transmission electron microscope (TEM). In conclusion, free forging could improve superelasticity and mechanical properties of Ti–51%Ni SMA.

A Nd:YAG laser welding technique with varying pulse widths was employed to weld Ti-27 at.% Nb shape memory alloy plates, and subsequent phase transformation characteristics and microhardness of welds were systematically investigated. From microstructure observation, it is apparent that weld seams contain a columnar growth with the low pulse and transferred into a combined growth of columnar and planar with the high pulse width. Moreover, grains in the weld zone exhibited a finer size when compared to the unwelded zone. A small amount of NbTi4was also found in the welds. In the forward transformation, transformation temperatures did not exhibit peaks, indicating the same behaviour as the original TiNb alloy. Microhardness of the TiNb welds increased as the pulse width increased when compared to the original TiNb alloy. However, little reduction in hardness occurred after a pulse width of 5 ms.

In Faranah Province (Guinea), the ratio of supply and demand of corn is approximately 1:2. The production is low and the deficit is covered by maize importation. This study was initiated in order to improve corn production by evaluating the effects of increasing doses of mineral fertilizers on the yield and economic profitability of corn. The experiment was conducted on a farm in Kamedankoude in a split plot with three replicates. Treatments included two varieties of maize (Perta and Kilissi113) and five doses of chemical fertilizers (D0=unfertilized control, D1=300 kg NPKS+200 kg urea • hm−2; D2=400 kg NPKS+800 kg urea • hm−2; D3= 200 kg NPKS+400 kg urea • hm−2and D4=500 kg NPKS+600 kg urea • hm−2). The results showed that all the agronomic parameters increased with increasing dose of fertilizers, except for the number of ears per plant. The two varieties of corn tested produced similar yields. However, the profitability of mineral fertilizers decreased with increased doses and with value/cost ratio of 3. We recommended a mineral fertilizer dose of 300 kg NPKS + 200 kg urea. The high prices of mineral fertilizers were often barriers to intensive maize cultivation, especially for low-income farmers. This study was a contribution to rational fertilization and adapted the socio-economic conditions of the region, with the background knowledge that most farmers in the regions earned low incomes.

Abstract

Rotary double inverted pendulum is a highly nonlinear complex system and requires a high performance controller for its control. Using gain matrix which is obtained through state feedback technique may create complexity while removing the steady-state error for all states. Incorporating an integral action can be an alternative for these errors. Therefore, a state space–based fractional order controller with fractional integral action is designed and tested on a rotary double inverted pendulum in this article. The fractional integral controller is designed based on Bode’s ideal transfer function. Two degree of freedom is considered for tuning purpose as well. The integer order controller based on the state space approach is also shown for comparison. Simulation and experimental results are presented for both controllers of this rotary double inverted pendulum system.

The shapes of particles play a crucial role in the transport and mechanical behavior of granular media. How densely particles of a specific shape can be arranged in a given volume has an enormous practical significance for many scientific and industrial fields. We developed a numerical workflow to investigate the effects of irregularly shaped frictionless, convex particles combined with the polydispersity of particle sizes on the porosity, permeability, and elastic bulk modulus of granular porous media. The workflow is based on the computationally generated three‐dimensional granular assemblies of both regular and irregularly shaped particles and pore‐scale simulation of physics to estimate the absolute permeability and elastic bulk modulus of the generated digital granular porous media. Our numerical results show that the porosity decreases by 14–25%, absolute permeability decreases by 45–76%, and elastic bulk modulus increases by 20–66% as we deviate from the regular‐shaped particle with the specified particle size distribution. How rapidly and to what degree these properties of granular assemblies of irregularly shaped particles change depends on particle size distribution. However, once the maximal densest packings of irregularly shaped particles with the prescribed aspect ratio are generated, any further change in the shape of particles has either a minimal impact or an opposite effects are observed. Overall, our numerical observations suggest that the irregular shape of particles has the greatest effect on permeability and the least effect on porosity in both monodisperse and polydisperse granular media. We developed a numerical workflow to investigate the effects of irregularly shaped frictionless, convex particles combined with the polydispersity of particle sizes on the physical properties of granular porous mediaHow rapidly and to what degree the properties of granular packings of irregularly shaped particles change depends on the particle size distributionThe irregular shape of particles has the greatest impact on permeability and the least effect on porosity in both monodisperse and polydisperse granular assemblies

ABSTRACTStudies of daily emtricitabine-tenofovir disoproxil fumarate (FTC-TDF) for HIV preexposure prophylaxis (PrEP) in men who have sex with men (MSM) modeled intracellular tenofovir-diphosphate (TFV-DP) in dried blood spots (DBS) to assess adherence and corresponding PrEP outcomes. We conducted a prospective, randomized, crossover pharmacokinetic study of TFV-DP in DBS during 33%, 67%, or 100% of daily dosing under directly observed therapy (DOT). Participants were assigned to two 12-week dosing regimens, separated by a 12-week washout. Forty-eight adults (25 women) from Denver and San Francisco were included. TFV-DP exhibited a median half-life of 17 days, reaching steady state in 8 weeks. TFV-DP was dose proportional with mean (SD) steady-state concentrations of 530 (159), 997 (267), and 1,605 (405) fmol/punch for the 33%, 67%, and 100% arms, respectively. Prior work in MSM demonstrated clinically meaningful TFV-DP thresholds of 350, 700, and 1,250 fmol/punch, which were estimated 25th percentiles for 2, 4, and 7 doses/week. In the present study, corresponding TFV-DP was within 3% of the prior estimates, and subgroups by site, race, and sex were within 14% of prior estimates, although males had 17.6% (95% confidence intervals [CIs], 6.5, 27.4%) lower TFV-DP than females. The thresholds of 350, 700, and 1,250 fmol/punch were achieved by 75% of men taking ≥1.2, 3.2, and 6 doses/week and 75% of women taking ≥0.6, 2.0, and 5.3 doses/week, indicating that lower dosing reached these thresholds for both sexes. In conclusion, TFV-DP arising from DOT was similar to previous estimates and is useful for interpreting PrEP adherence and study outcomes. (This study has been registered at ClinicalTrials.gov under identifier NCT02022657.)

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