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Hassan A.,University of PeshawarKhyber Pakhtunkhwa | Paganin V.A.,University of Sao Paulo | Ticianelli E.A.,University of Sao Paulo
Journal of Power Sources | Year: 2016

The CO tolerance mechanism and the stability of carbon supported PtW electrocatalysts are evaluated in the anode of a proton exchange membrane fuel cell (PEMFC) at two different temperatures. The electrocatalysts are characterized by energy dispersive spectroscopy, X-ray diffraction, and transmission electron spectroscopy. Employed electrochemical techniques include cyclic voltammetry, CO stripping, fuel cell polarization, and online mass spectrometry. At a cell temperature of 85 °C, the PtW/C catalyst shows higher CO tolerance compared to Pt/C due an electronic effect of WOx in the Pt 5d band, which reduces the CO adsorption. An increase in hydrogen oxidation activity in the presence of CO is observed for both the catalysts at a higher temperature, due to the decrease of the Pt-CO coverage. A reduction in the current densities occurs for the PtW/C catalyst in both polarization curves and cyclic voltammograms after 5000 cycles of the anode in the range of 0.1–0.7 V vs. RHE at 50 mVs−1. This decrease in performance is assigned to the dissolution of W, with a consequent increase in the membrane resistivity. However, the observed decline of performance is small either in the presence of pure H2 or in the presence of H2/CO. © 2016 Elsevier B.V.


Ahmad B.,University of PeshawarKhyber PakhtunKhwa | Khan M.S.,University of Agriculture, Peshawar | Haider A.,PGMI Lady Reading Hospital | Khan I.,University of PeshawarKhyber PakhtunKhwa
Pakistan Journal of Botany | Year: 2015

Brassica juncea (Czern & Coss., L.) is an important oilseed crop. Since it is attacked by several bacterial and fungal diseases, therefore, we developed an easy and simple protocol for the regeneration and transformation of B. juncea variety RAYA ANMOL to give rise to transgenic plants conferring resistance against various fungal diseases. The transformation was carried out using Agrobacterium with Chitinase gene. This gene was isolated from Streptomyces griseus HUT6037. We used two types of explants for transformation i.e. hypocotyls and cotyledons. Only hypocotyls explants showed good results regarding callus initiation. Different hormonal concentrations were applied i.e. BAP 2, 4 and 6 mgL-1 and NAA 0.1, 0.2 and 0.3 mgL-1. However, high transformation efficiency was observed by supplementing the medium with combination of 2 mgL-1 BAP and 0.2 mgL-1 for initiation of callus. Similarly 10 mgL-1 kanamycin and 200 mgL-1 cefotaxime also proved successful for the selection of transformed callus. In order to confirm the presence of transgenic callus Polymerase chain reaction was performed using specific primers for Chitinase gene. © 2015, Pakistan Botanical Society. All rights reserved.


Midrarullah,University of PeshawarKhyber Pakhtunkhwa | Midrarullah,Shaheed Benazir Bhutto University | Ahmed B.,University of PeshawarKhyber Pakhtunkhwa
Pakistan Journal of Botany | Year: 2015

Field experiment was performed to investigate the growth promoting activities of plant growth promoting rhizobacteria (PGPR) on different growth parameters of maize variety ‘Pahari’. Three bacterial strains Azospirillum brasilense strain R1, Azospirillum lipoferum strain RSWT1 and Pseudomonas strain Ky1 were used to inoculate maize. Plant growth promotion was observed in all inoculated treatments over un-inoculated control which was evident from increase in plant height, number of grains/ear, thousand grain weight and biological yield. Azospirillum lipoferum strain RSWT1 was more effective in plant growth promotion than other strains. The inoculation with Azospirillum lipoferum strain RSWT1 evidenced increase in plant height (8.82%), number of ear/plant (35%), ear length (27%), ear weight (19.4%) and thousand grains weight (11.8%) compared to control treatment. Similarly, Inoculation with Azospirillum brasilense strain R1 result increased in plant height (6.5%), number of ears/plant (45.9%), ear length (23.7%), ear weight (17.25%) and thousand grain yield (9.68%) as compared to control treatments. Higher biological yield (9210 kg/ha) was produced when treatment was done with Azospirillum lipoferum strain RSWT1 followed by treatment with Azospirillum brasilense strain R1 (8960 kg/ha). The study revealed that beneficial strains of PGPR can be used as biofertilizer for maize. © 2015, Pakistan Botanical Society. All rights Reserved.


Alam K.,University of PeshawarKhyber Pakhtunkhwa | Shaheen K.,University of Peshawar | Blaschke T.,University of Salzburg | Chishtie F.,Pakistan Academy of science | And 2 more authors.
Aerosol and Air Quality Research | Year: 2016

The present study investigates various types of aerosol in the Lahore city of Pakistan using Aerosol Robotic Network (AERONET) data over a six year period from 2007 to 2012. Aerosol optical depths (AODs) observed was in the range 0.2–1.12. An analysis of seasonal variations in AOD has indicated that the highest AOD values occurred in summer and the lowest in winter. The urban aerosols of the study area were classified on the basis of optical parameters such as AOD, Extinction Angstrom Exponent (EAE), Absorption Angstrom Exponent (AAE), Single Scattering Albedo (SSA), Asymmetry Parameter (ASY) and Refractive Index (RI). The AAE values were in the range from 0.25 to 3.2. Real Refractive Index (RRI) and Imaginary part of the Refractive Index (IRI) values were in the range from 1.5 to 1.6 and 0 to 0.005 respectively. The major contributions to the atmospheric aerosols over Lahore were from urban industrial emissions, fossil fuel burning and road/soil dust. Higher RRI values reflected larger re-suspended road dust particles and long-range transported particles, while lower values reflected increased anthropogenic absorbing carbonaceous aerosols over the area. The AERONET retrieved SSA (0.80–0.89) and ASY (0.70–0.83) values suggested a predominance of urban industrial, vehicular and dust aerosols over Lahore. The Derivative of Angstrom Exponent (DAE) was derived at a wavelength of 500 nm and was found to indicate a predominance of fine aerosols across all seasons, particularly during summer and autumn seasons. Back-trajectory analyses using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that the major air masses over Lahore originated from India, Iran and Afghanistan. © Taiwan Association for Aerosol Research.


Ullah S.,Quaid-i-Azam University | Begum M.,University of Malakand | Dhama K.,Indian Veterinary Research Institute | Ahmad S.,University of Malakand | And 2 more authors.
Asian Journal of Animal and Veterinary Advances | Year: 2016

The current study was aimed to investigate the genotoxic effect of an organophosphate pesticide malathion in the gills of a freshwater teleost rohu, Labeo rohita using alkaline Single Cell Gel Electrophoresis (SCGE)/comet assay. The 96 h LC50 of malathion was estimated for rohu in a semi-static system and was found to be 5 µg L-1. Specimens of rohu were exposed to LC50 of malathion. Gill tissues were sampled after 24, 48, 72 and 96 h of exposure. DNA damage was evaluated by studying different indices, including tail length (µm), percentage of DNA in tail, tail moment and olive tail moment using TriTek CometScore™. A linear relation was observed between exposure time and DNA damage in the gill cells. The current study revealed malathion as a potent inducer of DNA damage and comet assay as a reliable and sensitive assay for investigating and detecting DNA damage in vivo, induced in fish by genotoxic pesticides. In order to conserve the vanishing populations of rohu in natural aquatic bodies across the country, indiscriminate use of genotoxic pesticides such as malathion should be minimized. ©2016 Sana Ullah et al.


Rehman K.,University of PeshawarKhyber Pakhtunkhwa | Ali A.,University of PeshawarKhyber Pakhtunkhwa | Ahmed S.,University of PeshawarKhyber Pakhtunkhwa | Ali W.,University of PeshawarKhyber Pakhtunkhwa | And 2 more authors.
Journal of Earth System Science | Year: 2015

The seismotectonic structure of north Pakistan has been formed by ongoing collision between the Eurasian and Indian plates. North Pakistan and the adjoining areas experienced many large earthquakes in the past, which resulted in considerable damages and loss of life. A magnitude-homogenous earthquake catalogue for north Pakistan and its surrounding areas for the instrumental period from 1964 to 2007 is used for analysis. We presented seismicity picture of the Hindukush–Pamir–Karakoram (HPK), Kohistan Island Arc (KIA) and Hazara–Kashmir–Himalayas (HKH) using various histograms and time series plots of the dataset. The b-value for each accreted domain is derived separately and investigated through a process of mutual correlation. Our computed temporal variation of b-value in Hazara region shows a significant decrease prior to 2005 Kashmir earthquake. © Indian Academy of Sciences.


Ali N.,University of Technology Malaysia | Ajmal S.,University of PeshawarKhyber Pakhtunkhwa | Shah M.,University of PeshawarKhyber Pakhtunkhwa | Ahmed R.,University of Technology Malaysia | And 2 more authors.
Chalcogenide Letters | Year: 2014

Antimony doped tin sulphide thin films were prepared on glass substrate from SnS and Sb2S3 powder by thermal evaporation techniques. The thin films were annealed in argon gas at 250°C for 30 minutes. The films were characterized by X-ray diffraction (XRD), optical microscopy, optical absorption, photoconductivity, and hot-probe techniques. The XRD studies revealed that the annealed films are polycrystalline. The band gap was found to be in the range 2.2-2.6eV along with p-type conductivity. The value of the absorption coefficient is found to be higher than 105 cm-1. © 2014, National Institute R and D of Materials Physics. All right reserved.


Khan M.A.,University of PeshawarKhyber Pakhtunkhwa | Ullah A.,University of PeshawarKhyber Pakhtunkhwa | Rashid A.,University of PeshawarKhyber Pakhtunkhwa
Pakistan Journal of Botany | Year: 2015

The present research documents the use of ethnoveterinary medicine for curing various animal diseases. Most of the animal diseases are treated by using the local herbal medicines extracted from the plants. Survey was carried out and information was collected from the locals and farmers to identify the traditional remedies. For extraction of local knowledge about Ethnoveterinary Plants (EVPs) questionnaire method was adopted. A total of 27 animal diseases were reported, and it was concluded that diseases like milk deficiency, foot and mouth, diarrhea, worm infestation and mastitis are the most common diseases. A total of 83 plants within 44 families of which 1 species of fungi and gymnosperm and 81 species of angiosperm were identified for the treatment of various animal diseases. Most frequently plant parts used for ethnoveterinary medicine are fruit 24(28.57%), seed 18(21.42%), leaf 15(17.85), rhizome 7(8.33), bark 6(7.14), seed oil 5(5.95), whole plant 4(4.76) root 3(3.57), stem and bulb 2(2.380) and flower 1(1.19). The most frequent administration is oral followed by dermal. Information regarding botanical sources, family, local name, part used, method of preparation and application of these crude drugs were investigated in this study. The plant material is used singly or in combination. It is noted that 34 plants were used to treat more than one disease, while 49 plants are used to cure 1 particular disease. The local inhabitants use leaves, fruits, seeds, rhizomes and bulbs for preparation of various remedies and these remedies are used orally and topically. © 2015, Pakistan Botanical Society. All rights Reserved.


Ahmad B.,University of PeshawarKhyber Pakhtunkhwa | Naz S.,University of PeshawarKhyber Pakhtunkhwa | Azam S.,University of PeshawarKhyber Pakhtunkhwa | Khan I.,University of PeshawarKhyber Pakhtunkhwa | And 2 more authors.
Pakistan Journal of Botany | Year: 2015

Crude methanol extract and different fractions of the fruits of Sarcococca saligna (D. Don) Muel were investigated for various pharmacological/biological activities; antibacterial, antifungal, phytotoxic, haemagglutination, insecticidal and antioxidant activities. The results revealed that the plant possess good antibacterial activity (65.3 and 63.0%) against Methicillin Susceptible Staphylococcus aureus (MSSA) and Salmonella typhi, respectively while rest of the fractions along with crude methanolic extract (Crd. MeOH Ext.) were found moderately active or inactive against the tested pathogens. Low antifungal activity was observed for A, D, H and J fractions while other test samples were found inactive against the test fungi. Moderate phytotoxic activity was shown by C, D, G, H, K and L fractions at higher concentration (1000µg/ml). Moderate insecticidal activity was shown by G, H and I fractions against T. castaneum and G, H, I, K and L against R. dominica. A concentration dependent Diphenyl Picryl Hydrazine (DPPH) free radical scavenging activity was shown by the test samples. Fruits of the plant lack phytolactines as no haemagglutination activity were observed against human erythrocytes. © 2015, Pakistan Botanical Society. All rights Reserved.


Bibi H.,University of PeshawarKhyber Pakhtunkhwa | Alam K.,University of PeshawarKhyber Pakhtunkhwa | Bibi S.,University of PeshawarKhyber Pakhtunkhwa
Atmospheric Research | Year: 2016

Discrimination of aerosol types is essential over the Indo-Gangetic plain (IGP) because several aerosol types originate from different sources having different atmospheric impacts. In this paper, we analyzed a seasonal discrimination of aerosol types by multiple clustering techniques using AERosol RObotic NETwork (AERONET) datasets for the period 2007–2013 over Karachi, Lahore, Jaipur and Kanpur. We discriminated the aerosols into three major types; dust, biomass burning and urban/industrial. The discrimination was carried out by analyzing different aerosol optical properties such as Aerosol Optical Depth (AOD), Angstrom Exponent (AE), Extinction Angstrom Exponent (EAE), Abortion Angstrom Exponent (AAE), Single Scattering Albedo (SSA) and Real Refractive Index (RRI) and their interrelationship to investigate the dominant aerosol types and to examine the variation in their seasonal distribution. The results revealed that during summer and pre-monsoon, dust aerosols were dominant while during winter and post-monsoon prevailing aerosols were biomass burning and urban industrial, and the mixed type of aerosols were present in all seasons. These types of aerosol discriminated from AERONET were in good agreement with CALIPSO (the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) measurement. © 2016 Elsevier B.V.

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