JBAS Articles
JBASV8N2A32- Fragmentation Analysis For Scalable Wireless Local Area Networks
Journal of Basic and Applied Sciences - Volume 8 Number 2
Fragmentation Analysis For Scalable Wireless Local Area Networks
Minhaj Ahmad Khan
http://dx.doi.org/10.6000/1927-5129.2012.08.02.32
Abstract: Wireless networks are being deployed widely to provide network connectivity without requiring the web of physical wires. A collection of a small number of workstations connected using a wireless network forms a wireless local area network (WLAN) that follows the IEEE 802.11 standard. In a WLAN, the communication takes place using packets whose sizes may vary and have a significant impact on the delay incurred during transmission. In this regard, fragmentation may play a vital role in reducing the delay for efficient transmission across the network.
This paper analyzes the performance of WLANs with respect to the packet fragmentation. We simulate three network scenarios having 4, 8 and 12 wireless workstations respectively. The scenarios are simulated using OPNET IT Guru Academic Edition v 9.1 while incorporating a peer-to-peer (P2P) based communication model for each scenario. We compare the performance of non-fragmented and fragmented communication in terms of network delay and throughput. Our results show that the fragmentation minimizes the delay and increases the throughput, however its impact is highly dependent on the size of the underlying network.
Keywords: Wireless Networks, Fragmentation, Network Delay, Network Scalability, P2P Networks
JBASV8N2A24-Effect of Packing System, Calcium Chloride and Chlorine on the Storage Life of Strawberry Fruits (Fragaria ananassa cv. Kordistan)
Journal of Basic and Applied Sciences - Volume 8 Number 2
Effect of Packing System, Calcium Chloride and Chlorine on the Storage Life of Strawberry Fruits (Fragaria ananassa cv. Kordistan)
Fatemeh Mozhdehi, Vahid Abdossi and Sepideh Kalatejari
http://dx.doi.org/10.6000/1927-5129.2012.08.02.24
Abstract: Effect of packing system, calcium chlorite and chlorine was evaluated on storage life of strawberry fruits. Fruits were treated with commercial grade of chlorine (calcium hypochlorite at 0, 25, 50 and 100 ppm and sodium hypochlorite at 0, 25, 50 and 100 ppm with distilled water) for one minute and then treated with different grades of calcium chlorite 0, 0.5, 1 and 1.5 percentage for five minutes, then were divided to two groups; packed and non packed with plastic cover. Then fruits were evaluated for changes in quantity parameters; pH, TA (Titratable acidity), TSS (Total soluble solids), Dry and fresh weight ratio, water content, Anthocyanin, Ascorbic acid, Ca2+, Sugar and pectin. The results showed that the packed fruits treated with calcium chloride (at 0.5 and 1 percentage) and chlorine (at 50 ppm) remained better when compared with non packed fruits. It was found that packing treatment had not a significant effect on pH. It can also deduce that packed treated fruits showed a lower TA, Anthocyanin, calcium, sugar and pectin while TSS, fresh to dry weight ratio, water content and ascorbic acid was higher in packed treated fruits.
Keywords: Strawberry, storage life, packing, post harvest, calcium chlorite, chlorine
JBASV8N2A25-The Palliative Effect of Bio-Organic Fertilizer on Lead Pollution in Lycopersicum esculentum Plants
Journal of Basic and Applied Sciences - Volume 8 Number 2
The Palliative Effect of Bio-Organic Fertilizer on Lead Pollution in Lycopersicum esculentum Plants
Mona M. Abdalla and Nada El-Khoshiban
http://dx.doi.org/10.6000/1927-5129.2012.08.02.25
Abstract: Lead is one of the hazardous heavy metal pollutants of the environment that originates from various sources. Soil contamination by lead reduces the quality of both soil and cultivated plants which often limits the production of some food products and animal feed. Thus, this study was undertaken to evaluate the effect of a bio-organic fertilizer, namely Acadian, a red algal extract, at recommended dose (RD) in alleviating the deteriorative effect of Pb at 0, 50, 100, 200 and 400 mg/l on tomato (Lycopersicum esculentum) plants. Accordingly, Pb-treated plants showed marked reductions in growth measurements as root and shoot length, fresh and dry weights of shoots,roots and fruits as well as number of leaves and fruits; in photosynthetic rates, stomatal conductance, net intercellular CO₂ rates (ΔCO₂) and in the contents of each of chlorophyll a, b and total chlorophyll.In addition, with the increase in level of Pb treatment in situ, total sugars, total nitrogen, catalase activity and major nutrient elements (P, K, Ca and Mg) were proportionally declined in both shoots and roots as well as proline of roots. At the other side, Pb treatment raised the levels of each of carotenoids, total soluble sugars, amino nitrogen, total soluble nitrogen, peroxidase, superoxide dismutase, phenols, lipid peroxidation, sodium, lead and iron in both roots and shoots of tomato plants as well as proline of shoots and transpiration rates. When tomato plants were supplemented with the recommended dose of Acadian solely or combined with Pb at all rates, significant increases in all measured growth parameters (shoot and root length, fresh and dry weights of shoots, roots and fruits, number of leaves and fruits), photosynthetic rates, stomatal conductance, ΔCO₂, the contents of each of chlorophyll a, b, total chlorophyll as well as the contents of total sugars, total soluble sugars, total nitrogen, total soluble nitrogen, amino-N, P, K, Ca and Mg in tomato shoots and roots were obtained. Conversely, Acadian fertilization negatively reduced the carotenoid values, the activity of antioxidant enzymes(catalase, peroxidase and superoxide dismutase), the amounts of phenol, Pb, Na, Fe and the level of lipid peroxidation in both shoots and roots of tomato plants, whereas, it positively affected transpiration rates. On the otherside, when Acadian where added to lead at different rates there were either synergistic increases in the activities of these antioxidant enzymes and the level of phenol and lipid peroxidation or decreases in the carotenoid, Na, Fe and Pb contents as well as transpiration rates. Thus, it is manifested that Acadian can be used to improve the safety, quality and productivity of lead polluted plants.
Keywords: Lead, bio-organic fertilizer, growth, gas exchange,metabolites, antioxidants, antioxidant enzymes
JBASV8N2A26-Heavy Weight Protein Affected by Lead Acetate in Bactrocera dorsalis
Journal of Basic and Applied Sciences - Volume 8 Number 2
Heavy Weight Protein Affected by Lead Acetate in Bactrocera dorsalis
Rizwanul Haq, M. Farhanullah Khan and Ehteshamul Haq
http://dx.doi.org/10.6000/1927-5129.2012.08.02.26
Abstract: The studies were carried out on toxic effects of lead acetate, which could contaminate the environment, such as food, water, air and soil, therefore insects could be influenced easily by the lead., Bactrocera dorsalis was studied at 48 hours post treatment, under the effects of lead acetate, in different concentrations. It was observed that, under the effects of lead abnormalities, and deformity were developed in the larvae of flies. Thus these flies could present a useful module for the quick transmission of the environmental hazards of lead, which exerts a specific physiological and morphological effect on their bodies.
Keywords: Effects, lead acetate, Bactrocera dorsalis