3,098 research outputs found
A Compact and Simply-Constructed All-metal Circularly Polarized Ridge-Waveguide Slotted Antenna Array for Vehicle Mounted Satcom on the Move (SOTM) Communication Application
In this paper, a novel circularly polarized (CP) ridge-waveguide slotted antenna array is proposed for vehicle used Satcom on the Move (SOTM) applications. The antenna array is designed closely following the required factors for generating the circular polarization. The proposed antenna array is constructed on a symmetrical single-ridge slotted waveguide. Each antenna element consists of a pair of inclined slots opened on the narrow walls, and longitudinal slots opened on the bottom of the U-shaped wall of the waveguide. The inclined slots and the longitudinal slots are able to radiate orthogonal electric-fields independently with a phase-difference of 90°. After a vector superposition in the far-field by using this design, the circular polarization could be realized with extremely low axial ratio theoretically. Several essential parameters affecting the CP performance are also studied in this paper. To verify the feasibility of the proposed approach, a four-element CP antenna array is simulated, fabricated and measured. Results show that the obtained prototype achieves a measured impedance bandwidth of 14.74% from 9.24 GHz to 10.71 GHz with S11 < -10 dB, and a 3-dB axial ratio bandwidth of 19.1% from 9.0 GHz to 10.9 GHz
Electrically and magnetically controlled optical spanner based on the transfer of spin angular momentum of light in an optically active medium
An optical spanner is a light beam that can exert a torque on an object. It is demonstrated in this Rapid Communication that, with the aid of applied electric and magnetic fields, a light beam with initially linear polarization and initially zero total spin angular momentum can interact with an optically active medium, resulting in a change of the ratio of left-handed circularly polarized photons to right-handed ones. Thus the total spin angular momentum of the light is changed, which leads to a torque, creating an electrically and magnetically controlled optical spanner on the medium. For a linearly polarized 632.8 nm laser beam incident on a 100-mu m-long Ce:Bi12TiO20 whisker crystal with 5 mu m radius, if the magnetic field is fixed at -1.8 T, both the left- (right-)handed circularly polarized photon number and the total spin angular momentum vary with the applied electric field in a sinusoidal way, which means the torque exerted by the optical spanner on the crystal also varies sinusoidally with the electric field. It is found that at 50 (or-50) kV/cm, 56% right- (left-)handed circularly polarized photons are translated into left- (right-)handed ones, which corresponds to a transfer of 0.56h spin angular momentum contributed by each photon
Airway neutrophilian in bronchiectasis: the role of TNF-α in vivo
Session - Respiratory & Critical Care Medicine: no. S-RC-5published_or_final_versio
Modelling the effects of beverage substitution during adolescence on later obesity outcomes in early adulthood: results from the Raine study
High sugar-sweetened beverage (SSB) consumption has been linked with obesity. The present study examined the associations between adolescent SSB intake and body mass index (BMI), waist circumference (WC), and overweight status in early adulthood, and modelled the association of alternative beverage substitution with BMI and WC. Data of offspring from the Western Australian Pregnancy Cohort (Raine) Study at ages 14 and 22 years were used (n = 667). SSB intake at 14 years (100 g/day) was associated with higher BMI (β = 0.19 kg/m2, 95% CI 0.04, 0.33), WC (β = 0.41cm, 95% CI 0.04, 0.78), and being overweight at 22 years (OR 1.10, 95% CI 1.02, 1.18). Every 100g modelled substitution of SSB with milk at age 14 years was associated with lower BMI (-0.19 kg/m2) and WC (-0.52 cm) at age 22 years. Replacement of SSB with diet drink was associated with higher BMI and WC. No association was found for substitutions of SSB with water, tea/coffee, or 100% fruit juice with BMI or WC. SSB intake during adolescence was associated with higher BMI, WC, and being overweight in early adulthood. Milk as an alternative to SSB was associated with less adiposity. Caution is necessary in recommending diet drinks as a SSB alternative
Pseudomonas aeruginosa pyocyanin (PYO) down-regulates inducible nitric oxide synthase (iNOS) expression in human bronchus
Session - Respiratory & Critical Care Medicine: no. S-RC-6published_or_final_versio
Up-regulation of circulating adhesion molecules in stable bronchiectasis
Session - Respiratory & Critical Care Medicine: no. S-RC-4published_or_final_versio
Antioxidant treatment enhances human mesenchymal stem cell anti-stress ability and therapeutic efficacy in an acute liver failure model
published_or_final_versio
Down-expression of inducible nitric oxide synthase (iNOS) and endothelial (Enos) proteins and mRNA iNOS in bronchiectasis in vivo
published_or_final_versio
Downregulation of endothelin (ET)-1 and interleukin (IL)-8 expression in human respiratory mucosa by Pseudomonas aeruginosa pyocyanin (pyo) and 1-hydroxy-phenazine (HP)
published_or_final_versio
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