Muhammad Abdullah

Analyzing the non-linear effects at various power levels and channel counts on the performance of DWDM based optical fiber communication system

In order to expand the capacity of optical fiber communication system the most important phenomena is the emergence of dense wavelength division multiplexing (DWDM). Using DWDM, multiple channel of information can be transmitted on single fiber. There are some limiting factors related to data rate and capacity in DWDM optical fiber communication system. These limiting factors can be linear or non-linear. We can compensate the linear effect such as dispersion and attenuation by using pulse having right shape called soliton but the non-linear effect accumulate. The most important non-linear effect occur in the fiber optics communication system are Self phase modulation(SPM), stimulated brillouin scattering (SBS), Cross phase modulation (XPM), Four wave mixing (FWM) and Stimulated Raman scattering (SRS). These non linear effects are the most important limiting mechanism to the capacity of optical fiber communication system. Self phase modulation (SPM), Stimulated brillouin scattering (SBS) occurs only in single channel fiber optics communication system and Cross phase modulation (XPM), Four wave mixing (FWM), Stimulated Raman scattering (SRS) have impact on multichannel DWDM fiber communication system. In this paper, we analyze the impact of cross phase modulation (XPM), Four wave mixing (FWM), stimulated Raman scattering (SRS) on DWDM communication system at different power level & different number of data channels. We also describe some novel technique to reduce the effect of these non linearities (XPM, FWM, SRS) in DWDM fiber communication system. For simulation we use OptiSystem software.

Novel Approaches for Suppression of Four Wave Mixing in WDM System Using Concocted Modulation Techniques

The problem of four wave mixing (FWM) has become the principle focus for communication Engineers in designing a wavelength division multiplexing (WDM) system which is generated due to the optical nonlinear effect of fiber in multichannel systems. It has been observed through simulations results of different techniques that FWM effect becomes maximum when the fiber dispersion level approaches to zero. In this paper we have investigated the hybrid modulations for suppressing the FWM effect in 2.5Gbps system on OptiSystem Software and proposed the three hybrid modulators schemes depending upon the level of FWM suppression considering the results of eye diagram at different power levels. During simulation we use the default values of the parameters of modulators employed. Three schemes, High level reduction, Low level reduction and Intermediate level reduction have been implemented using combination of different modulators in this paper and their simulation results show that the Intermediate level reduction technique (Hybrid Tripely Technique) is comparatively the better one.

Impact of different mating sex ratios on reproductive efficiency of silver pheasant Lophura nycthemera (Galliformes, Phasianidae)

The present study was conducted to evaluate the impact of different mating ratios (male-female) on egg production, egg fertilization %, egg hatching % and courtship behavior in Silver Pheasant Lophura nycthemera at three stations for a period of 16 weeks. The birds were kept in four groups with following malefemale ratios: Group-A (1:2), Group-B (1:3), Group-C (1:4) and Group-D (1:5). The results showed that Group-B (1:3) ratio has significant effect on mean number of eggs (1.75 ± 0.15), Group-C (1:4) on weight of eggs (93.22 ± 5.02), Group-C (1:4) and Group-D (1:5) on egg fertilization and hatching % while Group-B (1:3), Group-C (1:4) and Group-D (1:5) on time spent in mating. The feed consumed and feed conversion ratio was significant in Group-D (1:5).

Improving drought tolerance in maize by foliar application of boron: water status, antioxidative defense and photosynthetic capacity

ABSTRACT Boron (B) plays a vital role in cell division and elongation in apical meristem. Drought stress (DS) severely reduced the B-uptake and thus growth and crop-productivity of plants. The aims of this study were to evaluate whether foliar application of B corrects physiological-disorders under DS in two contrasting maize genotypes i.e. Dekalb-6525 (drought-tolerant) and Yousafwala-hybrid (drought-sensitive). Initially, foliar rate of B (0, 2, 4 and 6 mg L−1) was optimized in terms of improved plant growth under drought-stress. Then, optimized rate of B (4 mg L−1) was applied to assess the physiological and biochemical basis of B-induced improved growth of maize under deficit-moisture supply. Drought-stress reduced the growth of plants by lowering in water-status (leaf water-relations), photosynthetic capacity (gas-exchange aspects, photosynthetic-pigments), membrane permeability, imbalance in redox potential (oxidative-stress, antioxidant-defense system) and tissue-B concentration. Application of B considerably improved maize growth by improving water-status, photosynthetic capacity, tissue-B concentration as well as up-regulation of antioxidative defense-system. Moreover, ameliorative effects of B on maize was also evident from stress relieving indicators such as slight decrease in accumulation of proline, total free amino-acids, total soluble-sugars and MDA content under water-deficit conditions. In addition, cultivar Dekalb-6525 showed considerable improving response to B application over Yousafwala-hybrid.

Efficacy Studies of Natural and Synthetic Iron Sources among Anemic Pregnant Women in Community of Faisalabad-Pakistan

In present study, different treatments enriched with natural and synthetic Iron sources along with control were developed and evaluated for proximate composition, mineral content, calorific values and sensory attributes fortnightly for sixty days and their efficacy was tested among anemic pregnant women for ninety days. Blood of 787 pregnant women was investigated for Hb status. Among them 38.50 % were found anemic (Hb < 11 g/dL) whose blood was further analyzed for complete blood count (CBC), serum Ferritin, serum Fe, total Fe binding capacity (TIBC), transferrin saturation (TS) and mean corpuscular volume (MCV) to find IDA victims. Hence, 70.29 % pregnant females were identified as IDA sufferer. Finally, 200 volunteers were assorted randomly into 4 treatment groups. As regards product development, all treatments provided 50 % RDA (13.5 mg) of Fe except placebo (T0). The significant variations (P-value <0.05) in anthropometrics, energetics and dietary intakes were observed during the study. Hematological indices were improved significantly by T2 in 90 days as RBC count (4.60±0.027 M/uL), Hb (11.01±0.039 g/dL), Hct (33.57±0.091 %), MCV (75.00±0.117 fL), MCH (24.96±0.089 pg), MCHC (30.10±0.101 g/dL), Serum Fe (47.72±0.219 ug/dL), TIBC (373.42±1.154 ug/dL) and TS (10.20±0.093 %). However, serum Ferritin had maximum uplift (8.28±0.234 ng/mL) by T1. Liver function tests (LFTs) and renal function tests (RFTs) of volunteers showed safety of intervention. A significant positive correlation (P-value <0.05) was also found amongst indices of IDA. The outcomes of the current research work showed that natural iron sources like blackstrap molasses, dried apricots, dried dates and rape seeds are cost effective and healthful foods having high bio-available Fe as compared to synthetic Iron sources (Ferrous sulphate) in combating IDA among pregnant women.

Design and Analysis of Pyramidal Conformal Antenna with Circular Sub-arrays Mounted on a Moving Platform

In this paper, we have proposed the idea of designing a pyramidal conformal array antenna and install it on a moving vehicle. Uniform circular planar array is used and it is replicated to design pyramidal shape conformal array antenna. Single panel circular planar array at 72 degree and at 42 degree is used to build the array geometry of pyramidal shape conformal array. By using circular arrays at 42 degree and at 72 degree the 3-D radiation pattern of pyramidal conformal array antenna has been shown. By using same pyramidal conformal array antenna with different phase slopes the idea of tracking target in the air and on ground is introduced. The applications of pyramidal conformal phased array radar system in defense and in automotive industry are presented in the end.