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Search Results: 1 - 10 of 9491 matches for " Wasim Ahmed "
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Kinetics and Modeling of H2S Removal in a Novel Biofilter  [PDF]
Zarook M. Shareefdeen, Wasim Ahmed, Ahmed Aidan
Advances in Chemical Engineering and Science (ACES) , 2011, DOI: 10.4236/aces.2011.12012
Abstract: Biofiltration has become a widely accepted technology for the removal of hydrogen sulfide (H2S) which is one of the major odor causing gases present in the air streams of municipal wastewater treatment facilities. In addition to odorous nature, H2S is toxic and corrosive. In this study, a biofilter which uses a novel media was employed in a pumping station which is closely located at the University City, Sharjah, UAE. The H2S removal performance data were collected and subsequently used in the determination of kinetics and modeling of H2S. The data were best represented by a first order biofilter model. Based on the first order kinetic constant, a correlation is developed to predict concentrations at the biofilter outlet. Based on the predicted outlet concentrations and dispersion (gaussian and US-EPA AERMOD) models, a study on H2S dispersion is conducted. The dispersion study confirmed a biofilter installation at the pumping station site would significantly reduce H2S levels in the University community and would provide cleaner air.
Singular Value Inequalities for Compact Normal Operators  [PDF]
Wasim Audeh
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2013, DOI: 10.4236/alamt.2013.34007
Abstract: We give singular value inequality to compact normal operators, which states that if \"\"is compact normal operator on a complex separable Hilbert space, where \"\"is the cartesian decomposition of \"\", then \"\"\"\"Moreover, we give inequality which asserts that if \"\"is compact normal operator, then \"\"\"\".Several inequalities will be proved.
More Results on Singular Value Inequalities for Compact Operators  [PDF]
Wasim Audeh
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2013, DOI: 10.4236/alamt.2013.34006

The well-known arithmetic-geometric mean inequality for singular values, according to Bhatia and Kittaneh, says that if \"\" and \"\"are compact operators on a complex separable Hilbert space, then \"\"\"\"Hirzallah has proved that if \"\"are compact operators, then \"\" \"\"We give inequality which is equivalent to and more general than the above inequalities, which states that if \"\"are compact operators, then \"\"\"\"

Applications of Arithmetic Geometric Mean Inequality  [PDF]
Wasim Audeh
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2017, DOI: 10.4236/alamt.2017.72004
Abstract: The well-known arithmetic-geometric mean inequality for singular values, due to Bhatia and Kittaneh, is one of the most important singular value inequalities for compact operators. The purpose of this study is to give new singular value inequalities for compact operators and prove that these inequalities are equivalent to arithmetic-geometric mean inequality, the way by which several future studies could be done.
催化学报 , 2013, DOI: 10.1016/S1872-2067(12)60554-3
Abstract: ?Ni/γ-Al2O3,Ni/Y-zeolite,andNi/H-ZSM-5catalystswerepreparedusingtheincipientwetnessimpregnationmethod.Theircatalyticperformanceindryreformingofmethanewasstudied.ThefreshandusedcatalystsanddepositedcarbonwerecharacterizedusingH2temperature-programmedreduction,temperature-programmedoxidation,N2adsorption-desorption,X-raydiffraction,andthermogravimetricanalysis.TheH-ZSM-5-supportedNicatalystprovedtobemorestablethantheothertwocatalysts,asithadthelowestcarbondeposition.
Outcomes in culture positive and culture negative ascitic fluid infection in patients with viral cirrhosis: cohort study
Lubna Kamani, Khalid Mumtaz, Umair S Ahmed, Ailia W Ali, Wasim Jafri
BMC Gastroenterology , 2008, DOI: 10.1186/1471-230x-8-59
Abstract: We analyzed 675 consecutive hepatitis B and/or C related cirrhosis patients with ascites admitted in our hospital from November 2005 to December 2007. Of these, 187 patients had AFI; clinical and laboratory parameters of these patients including causes of cirrhosis, Child Turcotte Pugh (CTP) score were recorded.Out of 187 patients with AFI, 44 (23.5%) had SBP while 143 (76.4%) had CNNA. Hepatitis C virus (HCV) infection was the most common cause of cirrhosis in 139 (74.3%) patients. Patients with SBP had high CTP score as compared to CNNA (12.52 ± 1.45 vs. 11.44 ± 1.66); p < 0.001. Platelets count was low in patients with SBP (101 ± 53 × 109/L) as compared to CNNA (132 ± 91 × 109/L), p = 0.005. We found a high creatinine (mg/dl) (1.95 ± 1.0 vs. 1.44 ± 0.85), (p = 0.003) and high prothrombin time (PT) in seconds (24.8 ± 6.6 vs. 22.4 ± 7.2) (p = 0.04) in SBP as compared to CNNA. More patients with SBP (14/44; 31.8%) had blood culture positivity as compare to CNNA (14/143; 9.8%), p = 0.002. Escherichia. Coli was the commonest organism in blood culture in 15/28 (53.5%) patients. SBP group had a higher mortality (11/44; 25%) as compared to CNNA (12/143; 8.4%), p = 0.003. On multiple logistic regression analysis, creatinine >1.1 mg/dl and positive blood culture were the independent predictors of mortality in patients with SBP.Patients with SBP have a higher mortality than CNNA. Independent predictors of mortality in SBP are raised serum creatinine and a positive blood culture.Ascitic fluid infections (AFI) are frequent and severe complication in cirrhotic patients and have a high morbidity and mortality. Two variants of AFI have been described in medical literature, 1) Spontaneous bacterial peritonitis (SBP) with polymorph nuclear (PMN) count >250/mm3 and positive ascitic fluid culture without any evidence of external or intra-abdominal source of infection [1] and 2) Culture negative neutrocytic ascites (CNNA) with PMN > 250/mm3 and a negative ascitic fluid culture [2].Th
Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in Pakistan
Javed Yakoob, Shahab Abid, Zaigham Abbas, Wasim Jafri, Zubair Ahmad, Rashida Ahmed, Muhammad Islam
BMC Gastroenterology , 2009, DOI: 10.1186/1471-230x-9-87
Abstract: H. pylori infection established by both rapid urease test and histology were studied. The cagA and vacA allelic status was determined by polymerase chain reaction (PCR). Sequencing of vacA i1 and i2 PCR product was carried out.Two hundred and twenty-four patients were included, 141 (63%) were males with a mean age of 45 ± 16, range 16-83 years. The virulence marker cagA was associated with GU in 20(63%) (p = 0.04), DU in 23(72%) (p = 0.003) and GC in 29(73%) (p = 0.001) compared to NUD in 51(42%). VacA s1am1 was associated with GU in 23(72%) (p = 0.001), DU in 17(53%) (p < 0.001) and GC in 23(58%) (p = 0.003) compared to NUD in 38(32%) while vacA s1bm1 was also associated with GU in 9(28%) (p = 0.001), DU in 12(37%) (p < 0.001) and GC 11(28%) (p < 0.001) compared to NUD in 13(11%), respectively. The diagnoses of GU in 21(66%), DU in 16(50%), GC in 20(50%) and NUD in 50(42%) were associated with moderately active chronic inflammation. CagA in 55(45%) (p = 0.037), vacA s1am1 in 51(51%) (P < 0.001), s1bm1 in 25(56%) (p = 0.002), s1am2 32(30%) (p < 0.001) and s1bm2 29(69%) (p = 0.004) were also associated with moderately active chronic inflammation.CagA was negative in majority of NUD patients with H. pylori infection. However, cagA was associated with peptic ulcer and GC. VacA allele's s1am1 and s1bm1 were associated with H. pylori associated diseases and inflammation.Helicobacter pylori (H. pylori) infection leads to the development of chronic gastritis and may lead to the development of duodenal and gastric ulcers, gastric adenocarcinoma and lymphoma [1-3]. The prevalence of H. pylori is high in developing countries. Its seroprevalence in Pakistan exceeds 58% of our general population and is common in asymptomatic population [4] A recent study revealed an early colonization/infection of infants with H. pylori and a prevalence of 67% at 9 months of age in a peri-urban community in Karachi, Pakistan [5]. The prevalence varies among countries with existing evidence sugg
Helicobacter pylori infection: approach of primary care physicians in a developing country
Shahid Ahmed, Mohammad Salih, Wasim Jafri, Hasnain Ali Shah, Saeed Hamid
BMC Gastroenterology , 2009, DOI: 10.1186/1471-230x-9-23
Abstract: This convenient sample based, cross sectional study was conducted in primary care physicians of Karachi, Pakistan from March 2008 to August 2008 through a pretested self-designed questionnaire, which contained 11 items pertaining to H. pylori route of transmission, diagnosis, indication for testing, treatment options, follow up and source of information.Out of 509 primary care physicians, 451 consented to participate with the response rate of 88.6%. Responses of 426 primary care physicians were analyzed after excluding 19 physicians. 78% of the physicians thought that contaminated water was the source of spread of infection, dyspepsia was the most frequent indication for investigating H. pylori infection (67% of the physicians), while 43% physicians were of the view that serology was the most appropriate test to diagnose active H. pylori infection. 77% of physicians thought that gastric ulcer was the most compelling indication for treatment, 61% physicians preferred Clarithromycin based triple therapy for 7–14 days. 57% of the physicians would confirm H. pylori eradication after treatment in selected patients and 47% physicians preferred serological testing for follow-up. In case of treatment failure, only 36% of the physicians were in favor of gastroenterologist referral.The primary care physicians in this study lacked in knowledge regarding management of H. pylori infection. Internationally published guidelines and World gastroenterology organization (WGO) practice guideline on H. pylori for developing countries have little impact on current practices of primary care physicians. We recommend more teaching programs, continuous medical education activities regarding H. pylori infection.The world wide prevalence of H. pylori is more than 50% [1,2]. It is more prevalent in developing countries as compared to developed countries [3]. Its prevalence in South Asia is ranging between 55 to 90% [4].H. pylori infection is prevalent in more than 90% of peptic ulcer disease p
A rare case of arterial avulsion presenting with occult blood loss following total hip arthroplasty: a case report
Claire Hall, Wasim S Khan, Sohail I Ahmed, David H Sochart
Journal of Medical Case Reports , 2009, DOI: 10.1186/1752-1947-3-9320
Abstract: We describe the case of a 55-year-old Caucasian man who underwent a total hip replacement. The patient's hemoglobin levels dropped postoperatively, but there was no obvious bleeding, hemodynamic instability, pulsatile mass, or limb ischemia. The patient's hemoglobin levels continued to drop despite nine units of transfused blood. Three days after surgery, the patient underwent an angiography that showed an avulsion injury to a posterior branch of the profunda femoral artery. The avulsion was ligated and the hematoma was evacuated.Vascular damage may present in many ways including obvious bleeding, haemodynamic instability, a pulsatile mass, limb ischemia, and occult blood loss. Any of these signs in isolation or in combination could represent a vascular injury and an urgent angiogram should be considered.According to the National Joint Registry 2006 Annual Report, over 60,000 primary and revision hip arthroplasties were performed in England and Wales. Complications occurred in around 5% of reported cases of hip arthroplasty. Iatrogenic arterial damage during total hip replacement (THR) is a rare but potentially life- or limb-threatening complication. To the best of our knowledge, this is the first reported case of an avulsion injury to a posterior branch of the profunda femoral artery during primary hip arthroplasty.A 55-year-old Caucasian man was admitted for a left-sided metal-on-metal primary hip arthroplasty for osteoarthritis. There was nothing significant in his medical history and he was a non-smoker with a body mass index (BMI) of 38. The patient experienced no significant intra-operative complications but required four units of blood immediately after his operation, which was attributed to intra-operative bleeding.On the first postoperative day, the patient's hemoglobin level was 65 gm/l. He was subsequently transfused with three units of blood. His low hemoglobin levels were again attributed to intra-operative bleeding. On the second postoperative day, the
Cost saving by reloading the multiband ligator in endoscopic esophageal variceal ligation: A proposal for developing countries
Zaigham Abbas, Lubna Rizvi, Umair Syed Ahmed, Khalid Mumtaz, Wasim Jafri
World Journal of Gastroenterology , 2008,
Abstract: AIM: To assess the cost savings of reloading the multiband ligator in endoscopic esophageal variceal ligation (EVL) used on the same patient for subsequent sessions.METHODS: This single centre retrospective descriptive study analysed patients undergoing variceal ligation at a tertiary care centre between 1st January, 2003 and 30th June, 2006. The multiband ligator was reloaded with six hemorrhoidal bands using hemorrhoidal ligator for the second and subsequent sessions. Analysis of cost saving was done for the number of follow-up sessions for the variceal eradication.RESULTS: A total of 261 patients underwent at least one session of endoscopic esophageal variceal ligation between January 2003 and June 2006. Out of 261, 108 patients (males 67) agreed to follow the eradication program and underwent repeated sessions. A total of 304 sessions was performed with 2.81 sessions per patient on average. Thirty-two patients could not complete the programme. In 76 patients (70%), variceal obliteration was achieved. The ratio of the costs for the session with reloaded ligator versus a session with a new ligator was 1:2.37. Among the patients who completed esophageal varices eradication, cost saving with reloaded ligator was 58%.CONCLUSION: EVL using reloaded multiband ligators for the follow-up sessions on patients undergoing variceal eradication is a cost saving procedure. Reloading the ligator thus is recommended especially for developing countries where most of the patients are not health insured.
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