Engineering and Technology Journal

CdTenanorods have been prepared with the different reaction time period from 1hour to 3 hours. CdTenanorods visible photoconductive detector films have been prepared on porous silicon layer with etching time 10 min. The CdTenanorods crystallization has been studied, the crystalline structure appears hexagonal when the samples dried under vacuum at 400C° for 1h. The Hall measurements show that all samples were p – type semiconductor. The response time of the fabricated CdTe detector with different reaction time was measured by illuminating the samples visible light (Halogen lamp) and its values were decreased from 0.411ms for 1hour to 0.364ms for 3 hours, the photoresponsivity of the detector for reaction time 3hours was to be 3.25×10-6A/W and specific detectivity is found to be 1.05×106W-1Hz1/2cm.

The design and sensitivity aspects of five stages tenth order active bandpass filter suitable for signal processing in electronic circuits are introduced. Simulation process performed is started by evaluating the voltage transfer function of the filter using the nodal approach to the second order activenet work model which represents each stage. The sensitivity analysis with respect to some parameter changes such as resonance frequency and quality factor is treated for proper choice of component values. The computational difficulties in the analog domain manipulations that arises through the cascaded arrangement of the filteris overcome by factorizing the terms in the denominator of the stated voltage transfer function with the aid of MATLAB 7.10.0(R2010a)software program. It was found that the increasing in the quality factor increases the magnitude, phase responses, higher deviation in magnitude sensitivity due to change in resonance frequency and lower frequency range due to change in quality factor. An increasing in the resonance frequency results in a better impulse and step response. The phase sensitivity due to change in resonance frequency shows that an increase in the quality factor gives higher deviation and this deviation is less in the sensitivity due to change in the quality factor. The simulation process of the circuit is done via the introduction of the Multisim software package version 9.0.155, offers good agreements with the results obtained.

In this paper, a novel analysis was carried out on the biosensor microcantilevers
in order to increase the sensitivity of a micro- cantilever based
biosensor piezoresistive. Holes were made and compared with the basic
rectangular (R), triangular (T), and step(S) profile cantilever. Effect of changing
the micro-cantilevers profile and its cross-section shape was investigated. A finite
element ANSYS was used to analyze these models. The micro-cantilevers are
made of silicon with elastic modulus 130Gpa and poisson’s ratio 0.28. Several
cases were studied by making one, two and three holes in each biosensor
piezoresistive micro-cantilevers (rectangular (R), triangular (T), and step(S) profile
cantilever). Results showed that triangular micro-cantilever with two holes (T22)
has the better sensitivity, also showed T12 respectively 61.7% and 65% higher
sensitivity than R12, S12.

In this work different weight percent of copper and zinc powders of 20 ìm particle
size were blended carefully with grease , and the final weight of samples are 2 g . The
samples were placed in containers were made from tephlon of 2.5 cm as a diameter . The
bottom window of container was fitted with 6 ìm mylar film . The samples were
subjected to X- ray fluorescence to measure the Cu Ká and Zn Ká lines intensities .
Sensitivity (m) and Lower Limit Detection (LLD) were calculated and plotted against
the weight fraction for all samples .