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Search Results: 1 - 10 of 136 matches for " Arshid Pervez "
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Remote Sensing Data Application to Monitor Snow Cover Variation and Hydrological Regime in a Poorly Gauged River Catchment—Northern Pakistan  [PDF]
Samreen Abdul Hakeem, Muhammad Bilal, Arshid Pervez, Adnan Ahmad Tahir
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.51005
Abstract:

Snow- and glacier-nourished river basins located in the Himalaya-Karakoram-Hindukush (HKH) ranges supply a significant amount of discharge in River Indus upstream Tarbela Dam. It is, hence, important to comprehend the cryosphere variation and its relationship to the stream flow in these high-altitude river catchments. The MODIS remotely sensed database of snow products was chosen to examine the average annual snow and glacier cover (cryosphere) variations in the Shigar River basin (poorly gauged mountainous sub-catchment of the Indus River). Hydrological regime in the area was investigated through monthly database of observed stream fluxes and climate variables (precipitation and mean temperature) for the Shigar River catchment. Analysis indicated the usefulness of remote sensing techniques for estimation of the snow cover variation in the poorly or un-gauged high-elevation catchments of the HKH zone. Results also showed that Shigar River discharge was influenced mainly by the seasonal and annual snow cover area (SCA) variation and the temperature seasonality. Moreover, it is important to uncover such inter-relationship of stream flow, climate variables and snow cover in the poorly gauged high-altitude catchments of Karakoram region for better water resource management and accurate flood hazards predictions at Tarbela.

Assessment of seed quality parameters and effect of physical and chemical treatments on seed germination of Myriophyllum Spicatum L.
Aijaz Ahmad Wani,Shahzada Arshid
Comunicata Scientiae , 2013,
Abstract: The present study was undertaken to understand the fruit and seed morphology, seed viability andeffect of various physical and chemical factors on seed germination allowing us to explore thespread potential and/or seedling recruitment mechanism in Myriophyllum spicatum L.. The fruit ofthe species is a schizocarp, while as seed is a nutlet. The seed set was recorded to be ranging from70.98-77.91% across the standing water populations, whereas no seed set was observed in runningwater populations due to the lack of an effective pollination system. The seed viability ranged from85-90%. For in-vitro seed germination studies, the seeds were subjected to different physical andchemical treatments under alternate light and dark as well as continuous dark conditions. Theseeds in control and those treated with different concentrations of GA3 and IAA and those whoseepicarp and mesocarp were removed did not show any signs of germination. However, it wasobserved that surgical exposure of the embryo (cutting of hard endocarp of seed) has a promotereffect on germination and maximum percentage germination (76.66 ± 5.77) was recorded due tosurgical exposure of embryo plus different concentrations of GA3. Moreover, a good germinationpercentage was recorded in seeds subjected to chilling treatment. Further, it was observed thatseed germination of one-year-old seeds was less if compared to the current year seeds and overallpercentage germination was higher in alternate light and dark if compared to continuous darkconditions in all the treatments.Thus, we conclude that the dormancy of the seeds is due to thehard endocarp and that the light has a promoting effect on germination. With the increase in theage of the seeds, there is decrease in their viability and hence germination. The chilling wintertemperature of the Kashmir is responsible for breaking the hard endocarp of the seeds leading totheir germination and hence spread of the populations.
Spectrophotometric Determination of Kelthane in Environmental Samples  [PDF]
Etesh K. Janghel, Y. Pervez
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.26083
Abstract: Sensitive spectrophotometric method for determination of kelthane in sub parts per million level is described, which is based on Fujiwara reaction. Kelthane on alkaline hydrolysis gives chloroform, which can be reacted with pyridine to produce red colour. The colour is discharged by addition of glacial acetic acid. Then Benzidine (4,4’-Bianiline) reagent is added due to which a yellowish-red colour is formed which has an absorption maximum at 490nm. Beer’s law is obeyed in the range of 3.3 - 26.0 µg (0.13 - 1.04 ppm) of Kelthane per 25ml of final solution. The molar absorptivity and Sandell’s sensitivity were found to be 4.32 × 105 L?mol–1?cm–1 and 0.022 µg?cm–2 respectively. The method is found to be free from interferences of other organochlorine pesticides and various co-pollutants and can be successfully applied for the determination of kelthane in environmental samples.
ADS/CFT Applied To Vector Meson Emission From A Heavy Accelerated Nucleus
Hoodbhoy, Pervez
High Energy Physics - Phenomenology , 2008, DOI: 10.1103/PhysRevD.78.115015
Abstract: We consider a classical source, moving on the 4-D boundary of a 5-D ADS space, that is coupled to quantum fields residing in the bulk. Bremsstrahlung-like radiation of the corresponding quanta is shown to occur and the S-matrix is derived assuming that the source is sufficiently massive so that recoil effects are negligible. As an illustrative example, using the ADS hard-wall model, we consider vector mesons coupled to a heavy nucleus that is moved around at high speed in an accelerator ring. The meson radiation rate is found to be finite but small. Much higher accelerations, such as when a pair of heavy ions suffer an ultra peripheral collision, cause substantial emission of various excited vector mesons. Predictions are made for the spectrum of this radiation. A comparison is made against existing photon-pomeron fusion calculations for the transverse momentum spectra of rho mesons. These have the same overall shape as the recently measured transverse momentum distributions at RHIC.
Diagnosis and Genotyping of Hepatitis C Virus by Polymerase Chain Reaction in Chronic Liver Disease Patients
Khalid Pervez
Pakistan Journal of Biological Sciences , 2000,
Abstract: All 50 blood samples from Chronic Liver Disease (CLD) patients were screened for (Antibodies against hepatitis C virus) AntiHCV by 3rd generation (Enzyme Linked Immuno-Sorbant Assay) ELISA for diagnosis and genotyping of HCV by (Polymerase Chain Reaction) PCR. Samples were screened by slot blot hybridization using P32 ATP labelled genotype specific oligonucleotide probes indicating prevalence of genotype HCV -1b which was further confirmed by southern hybridization and direct sequencing. Positivity by ELISA was 37% while with that of PCR was 42% in hepatitis patients indicating its sensitivity and reliability and can be used to determine the carrier state and hence its spread can be checked through blood screening.
Hepatitis C Virus Core Protein Expression for Enzyme Linked Immunosorbant Assay
Khalid Pervez
Pakistan Journal of Biological Sciences , 2000,
Abstract: HCV core region, being most conserved, in the whole genome can be used as a diagnostic marker in enzyme linked immuno-sorbant assay development. However, quasi species nature of HCV during its replication in host is the major hindrance in developing an effective therapeutic agent. Recombinant fusion protein for HCV immuno-assay from core region was prepared by PCR amplification and subsequent cloning in expression vector PET32a which was expressed by iso-propyl thio-Β-galactosides (IPTG) in E. coli strain DE3 followed by purification by affinity chromatography. Fusion protein as an antigen reacted with human antisera containing antibodies. This HCV specific immuno-assay development based on recombinant HCV core protein will be the foundation in developing antiviral immuno-assays in Pakistan.
Effect of Combination Chemotherapy on Hepatitis C Virus in Hepatic Patients
Khalid Pervez
Pakistan Journal of Biological Sciences , 2000,
Abstract: The under lying cause of non-A-non-b hepatitis (NANBH) in most of the cases is Hepatitis C Virus (HCV) which leads to liver cirrhosis and Hepatocellular Carcenoma (HCC). A limitation in the control of the disease is the failure to develop vaccine due to high rate of mutation in viral isolates. Detection of antibodies to HCV is an important indication of past and present infection in enzyme linked immuno sorbent assay (ELISA) but this has many limitations in low risk groups. The most sensitive assay is polymerase chain reaction (PCR) which has detection limit of 2000 viral genomes per ml of human serum. Nine out of fifty patients were selected on the basis of inclusion criteria. Only 4 parameters i.e Total Leucocyte Count (TLC) Erythrocyte Sedimentation Rate (ESR), Serum Bilirubin and Serum Glutamate Pyruvate Transaminase (SGPT) were raised above normal. They returned to normal by chemotherapy indicating the success of treatment but side effects and relapses were also observed. Alpha interferon (Alpha INF) and ribavirin combination chemotherapy has success rate of almost 40%. It is suggested on the basis of study that this combination should not be used as first line treatment, also there is need to educate both doctors and patients to go for liver biopsies for treatment before and after chemotherapy for ensured treatment.
CHRONIC LARYNGOTRACHEAL STENOSIS
SHAHID PERVEZ
The Professional Medical Journal , 2004,
Abstract: Objective: To evaluate the surgical management of the patientssuffering from chronic laryngotracheal stenosis. Design: Prospective study. Setting: ENT DepartmentCombined Military Hospital Rawalpindi. Period: May 1998 to Aug 2000. Materials & Methods: Seventeenconsective, diagnosed cases of chronic laryngotracheal stenosis were evaluated by history and thorough ENTexamination. Direct laryngoscopy was performed in all the patients. CT scan was carried out in 12 of them.Patients were classified according to the McCaffery’s system of staging. The surgical procedures performedranged from endoscopic dilatation and CO2 laser excision of stenosis to open reconstructive procedures. Meanperiod of follow up for each patient was 8.7 months, during which results of the repair were evaluated by theabsence/recurrence of the symptoms and success in decannulation. Results: Eight patients (47%) had stage-3,three (17.6%) had stage-1, two (11.9%) had stage-2, and one (5.9) had stage-4 laryngotracheal stenosis. Threepatients (17.6%) suffered from tracheal stenosis only. Five patients (29.4%, including all the patients with stage-1stenosis) were subjected to endoscopic dilatations or CO2 laser surgery; rest (70.6%, including all those withstage 2, 3 and 4 stenosis) required complex open reconstructive procedures. Laryngotracheoplasty wasperformed in 10 patients (58.8%). T-tube was placed in 8 of them. On the average each patient was subjectedto 4.6 operations involving 1.5 different kinds of surgical techniques. All the patients with stage-1 stenosisremained asymptomatic during the period of follow up. Recurrence of stenosis was noticed in both the patientsin whom T-tube was removed. Decannulation was successful in 3 out of 5 patients who were wearingtracheostomy. Conclusion: Treatment should be individualized. Milder form of stenosis requires relativelysimple procedures. Multiple operations and more than one surgical technique are frequently required. Even thenthe results are not uniformly satisfying. Decannulation is not always possible. Recurrence rate is high. Long-termfollow up is necessary. Careful preoperative evaluation, selection of most appropriate surgical technique,meticulous surgical skills and dedicated postoperative follow-up are essential for successful outcome.
TRANSURETHRAL RESECTION
ARIF PERVEZ
The Professional Medical Journal , 2007,
Abstract: Objective: To establish the current usage and results of transurethral resectionof prostate in patients of benign prostatic obstruction (BPO) who presented with severe irritative and obstructiveprostatic symptoms. Setting: Saleem Medical Complex Hospital Quetta. Period: From April 1997 to December 2004Patients & Methods: Transurethral resections for BPO were performed with 5% dextrose water in 500 consecutivepatients. All these patients were followed for early and late complications and followed up to 6 months after TURP.Results: Significant symptomatic improvement has been observed with minimal morbidity (14 %). None of the patienthad significant hematuria and TURP syndrome. Mean operative time was 45.0 minutes. Mean interval to catheterremoval was 26 hours. Only 15 patients (3%) revealed neoplastic changes in resected tissues. Incidence of secondaryhemorrhage, stricture urethra, epididymo-orchitis, retrograde ejaculation and impotence were observed in 10 (2%), 20(4%), 10 (2%), 5 (1%) and 20 (4%) patients respectively. Only 15 patients (3 %) who developed post-operative retentionand Re-TURP were performed in two patients for the residual prostatic tissue. None of the patient developedincontinence of urine. Pre operative and postoperative history of libido and sexual behavior was also assessed.
Experimental and numerical investigation of expandable tubular structural integrity for well applications
T. Pervez
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: Purpose: The ever-increasing energy demand has forced researchers to search for new and cheaper solutions for oil and gas production. The recent development of solid expandable tubulars (SETs) has resulted in design of slim oil and gas wells. The large plastic deformation experienced by the tubular under down-hole environment may result in premature and unexpected failures. The objective of this research is to investigate the structural integrity of SET for well applications to avoid such failures.Design/methodology/approach: In order to achieve the objectives, simulation work was carried out using finite element method and experimental tests were conducted on full size tubular for validation of numerical results.Findings: The required drawing force for expansion under different expansion ratios, surplus deformation, variations in tubular thickness and length were estimated numerically and experimentally. The differences in values using two approaches vary from 5% to 12%. Tubular wall thickness decreases as the mandrel angle, expansion ratio, and friction coefficient increase.Research limitations/implications: The issue of maximum expansion a tubular can be subjected to needs to be further investigated. Furthermore, the pre and post-expansion material properties need immediate attention of researchers to fulfil the dream of low-cost expandable solution.Practical implications: In recent years, solid expandable tubular technology has already made significant inroads in replacing conventional telescopic oil wells. It allows design and realization of slim wells, accessing difficult and ultra-deep reservoirs, well remediation, zonal isolation, drilling of directional and horizontal wells, etc.Originality/value: SET is an emerging technology for oil and gas industry. The current findings are very valuable for researchers and well engineers to design slim wells and enhance the productivity of older wells.
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