Effective Size Reduction Technique for Microstrip Filters

In this paper an effective size reduction technique using fractal structure is suggested. The proposed technique has been applied on a band stop and a low pass filter separately. This technique provides 42% reduction of size for the band stop filter and about 26% for the low pass counterpart. Both the designed structures are fabricated and the measured results are compared with the simulated results. The proposed technique does not require any recalculation or optimization of dimensions of the filter, and is straightforward to implement. The band stop filter is designed for the center frequency of 3 GHz where as the cut-off frequency for low pass filter is 2.5 GHz. A good agreement between the simulated and measured results is observed. A comprehensible explanation of the proposed technique is also provided.

Compact Low Pass Filter Design for L-Band Application

An effective technique to design compact low pass filter has been proposed in this paper. The proposed method is highly effective for L-band applications. Low impedance microstrip lines are arranged such that they work as open stubs to increase the selectivity of the filter. Using the proposed technique about 57% size reduction has been realized with sharper roll off characteristics. An empirical expression is derived to determine the dimension of resonators. For cut-off frequency of 1.7 GHz the investigated method has been fabricated and tested. There is a close agreement be-tween simulated and measured

Design and evaluation of aceclofenac ocular inserts with special reference to cataracts and conjunctivitis

The eyes present unique opportunities and challenges when it comes to the delivery of pharmaceuticals.While absorption by this route is bungling,there are a few side effects with conventional dosage forms.Ocular inserts were prepared with prolonged release of drug and minimum swelling within cul-de-sac using aceclofenac.The work focused on treatment of conjunctivitis and cataracts by formulating ocular inserts of different polymeric combination of aceclofenac using hydroxypropyl methyl cellulose(HPMC,3% to 5%),chitosan(3% to 5%),poly vinyle alcohol(PVA,3% to 5%),methyl cellulose(MC,3% to 5%) as drug reservoir and ethyl cellulose(EC) polymer as rate controlling membrane by solvent casting technique with the objective of increasing contact time,achieving controlled release and greater therapeutic efficiency.The prepared ocular insert were then evaluated for physical appearances tensile strength,elongation at break(%),weight variation,uniformity of thickness,moisture absorption(%),pH,folding endurance,Fourier Transform Infrared spectroscopy,differential scanning calorimetry.Physicochemical characterization and in vitro transcorneal permeation studies reveals that,the prepared ocular insert formulations F2 and F8 containing HPMC and PVA had released their drug content,98.54% and 96.24%,respectively,over an extended period of 24 h.Hence these formulations were selected as best optimized formulations.It can be concluded that hydroxy propyl methyl cellulose is a good film forming hydrophilic polymer which shows potential agent for ocular drug delivery system.Incorporation of polyethylene glycol enhances the permeability of aceclofenac ocular insert and has perfect zero order release,proving a promising controlled release delivery system.