A novel Multi-permittivity Cylindrical Dielectric Resonator Antenna for Wideband Applications

In this paper, a novel multi-permittivity cylindrical dielectric resonator antenna for wideband application is presented. The multi-permittivity cylinder is formed by combining two different permittivity material sectors in such a way that each sector (with constant permittivity) is 90 degree apart. A direct microstrip line coupling terminated with T-stub at the open end is used to excite the multi-permittivity cylindrical dielectric resonator. The angular position of the multi sector dielectric resonator with respect to the longitudinal axis of the microstrip line and length of the additional strip at the open end of the feeding circuit is key parameters for wideband operation of the antenna. By optimizing all parameters of the proposed antenna, wideband impedance bandwidth of 56% (12.1 GHz - 21.65 GHz) is achieved. The average gain of the antenna throughout the bandwidth is 5.9 dB with good radiation properties in both E-plane and H-plane. A well matched simulation and experimental results show that the antenna is suitable for wideband applications

Effect of retardation on the dynamics of entanglement between atoms

The role of retardation in the entanglement dynamics of two distant atoms interacting with a multi-mode field of a ring cavity is discussed. The retardation is associated with a finite time required for light to travel between the atoms located at a finite distance and between the atoms and the cavity boundaries. We explore features in the concurrence indicative of retardation and show how these features evolve depending on the initial state of the system, distance between the atoms and the number of modes to which the atoms are coupled. In particular, we consider the short-time and the long time dynamics for both the multi- and sub-wavelength distances between the atoms. It is found that the retardation effects can qualitatively modify the entanglement dynamics of the atoms not only at multi- but also at sub-wavelength distances. We follow the temporal evolution of the concurrence and find that at short times of the evolution the retardation induces periodic sudden changes of entanglement. To analyze where the entanglement lies in the space spanned by the state vectors of the system, we introduce the collective Dicke states of the atomic system that explicitly account for the sudden changes as a periodic excitation of the atomic system to the maximally entangled symmetric state. At long times, the retardation gives rise to periodic beats in the concurrence that resemble the phenomenon of collapses and revivals in the Jaynes-Cummings model. In addition, we identify parameter values and initial conditions at which the atoms remain separable or are entangled without retardation during the entire evolution time, but exhibit the phenomena of sudden birth and sudden death of entanglement when the retardation is included.Comment: 16 pages, 14 figure

Potentials of solar power plant in Waru Tua

Penajam Paser Utara Regency is located on the coast of East Kalimantan Province. This regency has a huge solar resource potential, but the agreement in this regency still lacks electricity networks and can be resolved by the people in this regency still in dire need of electricity for street lighting, and daily electricity needs. One of them is in the village of Waru Tua, where this area is in great need of lighting in the dock area because it requires residents to make Aliving as a fisherman. Waru Tua really needs electricity for lighting at night Waru Tua Pier because it has to be a gathering place for residents before going to sea to prepare everything that must be prepared before going to sea. Discussing the research carried out examining the potential of solar power in Waru Tua. Based on existing considerations, and the potential proposed by the area, the method used is to measure the sunlight at Waru Tua Pier using Luxmeter, then the data is processed using the Simulink applicationin MATLAB to obtain the value of the amount of sunlight in the area, which is 16 KW with a total solar cell of 250 Wp

Identification and Antibiotic Resistance of Streptococcus agalactiae from Red Hybrid Tilapia (Oreochromis niloticus) in Local Wet Markets

The existence of ethiology disease like Streptococcus agalactiae could be major problems in aquaculture field. In this study, investigations of red tilapia sold around local wet market were recorded. To detect the S. agalactiae in wet markets from disease potential and measure the antibiotic susceptibility test. Selected organs such as eyes, gills, heart and intestine were inoculated onto blood agar and incubated at 37°C for 24 h. Morphology of S. agalactiae were Gram-positive, translucent pin point colony, and has oxidase and catalase negative. Eight isolates of S. agalactiae were confirmed using PCR. The isolates samples were susceptible to imipenem (10 µg), gentamicin (10 µg), ciprofloxacin (5 µg) and nalidixic acid (30 µg). In contrast, they were resistance to ampicillin (10 µg), amoxicillin-clavulanic (20/10 µg), erythromycin (5 µg), neomycin (30 µg), norflaxacin (10 µg), streptomycin (10 µg) and trimethoprim-sulphamethoxazole (1.25/23.5 µg). Furthermore, the occurrence of resistant isolates is a matter of public health concern

A Ka-Band Horn Antenna Excited With Parasitic Dielectric Resonator Antenna

A pyramidal horn antenna excited with parasitic dielectric resonator (DR) antenna for use at Ka-band frequencies is proposed