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In this paper, a novel compact and tunable impedance transmission line transformer is presented for the first time. The transformer is designed using a left handed coplanar waveguide transmission line on a ferrite substrate. Based on the dispersive properties of the ferrite medium, the theoretical study of the transformer has been carried out using its equivalent circuit analysis and the composite right / left handed transmission line theory. The theoretical study was verified through full wave electromagnetic numerical simulations. The results show that the transformer matches a 25 Ω load to a 50 Ω line with tunability from 2.55 GHz to 3.2 GHz. The return loss at center frequency is better than 20 dB with insertion loss better than -1 dB. The transformer has a very compact size with dimensions of 4.25 × 21 mm, showing approximately 64% reduction in size in comparison with a conventional right-handed transformer within the same operating frequency band. Moreover, the proposed coplanar waveguide transformer configuration has smaller demagnetization factor and hence it requires smaller DC magnetic bias values compared to microstrip configuration. [ABSTRACT FROM AUTHOR]

The objective of our study was to assess the efficacy and safety of dexmedetomidine given in a small dose for a 1-h infusion as an adjuvant to local analgesia in ophthalmic operations. The study was double-blind prospective, randomized, and placebo controlled. We studied the effects of a small dose of dexmedetomidine (0.5 µ·kg−1·h−1 for 10 min followed by 0.2 µ·kg−1·h−1 for 50 min. Patients were divided randomly into two groups with 20 patients in each: group A was the study group and group B was the placebo group. Heart rate, systolic blood pressure, and diastolic blood pressure were significantly lower in the dexmedetomidine group than the placebo group. Bispectral index values were significantly lower in the dexmedetomidine group than the placebo group. Also, intraocular pressure significantly decreased in the dexmedetomidine group compared to the placebo group. The study revealed that dexmedetomidine in the studied dose has a sedative effect, provides safe control of heart rate and blood pressure, and also decreases intraocular pressure during ophthalmic surgery under local anesthesia. [ABSTRACT FROM AUTHOR]

This paper proposes a new algorithm for Arabic optical font recognition (AOFR) as the first stage for Arabic optical character recognition. The proposed algorithm uses scale-invariant detector, gradient-based descriptor, and k-means clustering. The scale-invariant detector is used to find key points that identify the font of an image of printed Arabic text. The work in this paper compares between several scale-invariant detectors and selects the best one for AOFR. A gradient-based descriptor similar to the one in the famous scale-invariant feature transform algorithm is used to describe the detected key points. In addition, k-means clustering is used for font classification. In this paper, the mean recognition rate is used to evaluate the performance of the proposed algorithm. The proposed algorithm shows superior performance when compared with recently published algorithms for AOFR. [ABSTRACT FROM AUTHOR]