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Search Results: 1 - 10 of 629332 matches for " M. H. R. Khan "
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Quality Control of Dual Energy X-Ray Absorptiometry  [PDF]
M. A. Reza, A. K. Paul, H. R. Khan, M. R. Rahman
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2018, DOI: 10.4236/ijmpcero.2018.73026
Abstract: Dual energy X-ray absorptiometry (DXA) is a dominant technique for the measurement of bone mineral density (BMD). Quality control (QC) of DXA is very important for the accuracy of results and correct interpretation made by the physician. We have performed the quality control procedures of Lunar DPX Pro bone densitometer according to the manufacturer’s recommendations and current clinical guidelines at the Institute of Nuclear Medicine & Allied Sciences (INMAS), Khulna. The objective of this study is to maximize the performance of the technologist as well as the reliability of the equipment (Linearity, X-ray tube output, Half value layer, Kerma-area product, Radiation field size, Fan angle, Spatial resolution, Room safety). The study result shows that the mean BMD reading is 1.004 g/cm2 with a standard deviation of 0.0035 and co-efficient of variation 0.34%. It also shows that the precision of the technologist is good and there is no malfunctioning in the DXA bone densitometer.
Magnetic Hysteresis and Complex Initial Permeability of Cr3+ Substituted Mn-Zn Ferrites  [PDF]
F. Alam, M. L. Rahman, M. H. R. Khan, A. K. M. Akther Hossain
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.514122

The impact of Cr3+ ion on the magnetic properties of Mn0.50Zn0.50CrxFe2-xO4 (with x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) has been studied. Ferrite samples were synthesized by combustion method and sintered at various temperatures (1250°C, 1300°C and 1350°C). The structural properties were investigated by means of X-ray diffraction patterns and indicated that the samples possess single phase cubic spinel structure. The lattice parameter decreases with the increase in Cr3+ content, as the ionic radius of Cr3+ ion is smaller than that of Fe3+. The average grain size (D), bulk density (ρB) and initial permeability μidecreases with increase

Structural and Magnetic Properties of Mn0.50-xZn0.50CuxFe2O4  [PDF]
Farhad Alam, Mohammad H. R. Khan, Hari N. Das, Akther A. K. M. Hossain
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.412106

Mn0.50-xZn0.50CuxFe2O4 (where x = 0.0 - 0.3) ferrites have been synthesized by auto combustion method. X-ray diffraction patterns reveal that all compositions are of single phase cubic spinel structure. The lattice parameter decreases with the increase in Cu2+ content obeying the Vegard’s law. The bulk density, average grain size, initial permeability, Néel temperature and saturation magnetic induction of Mn0.50-xZn0.50CuxFe2O4 increased with increasing Cu2+content. It is observed that both density and initial permeability increase with increasing sintering temperature. The maximum initial permeability is found to be 1061 which is almost four times greater than that of the parent composition. The resonance frequency of all the samples shifts towards the lower frequency as the permeability increases with Cu2+ content. It is observed from B-H loops of Mn

Measurement of time delay for a prospectively gated CT simulator
Goharian M,Khan R. F. H.
Journal of Medical Physics , 2010,
Abstract: For the management of mobile tumors, respiratory gating is the ideal option, both during imaging and during therapy. The major advantage of respiratory gating during imaging is that it is possible to create a single artifact-free CT data-set during a selected phase of the patient′s breathing cycle. The purpose of the present work is to present a simple technique to measure the time delay during acquisition of a prospectively gated CT. The time delay of a Philips Brilliance BigBore (Philips Medical Systems, Madison, WI) scanner attached to a Varian Real-Time Position Management (RPM) system (Varian Medical Systems, Palo Alto, CA) was measured. Two methods were used to measure the CT time delay: using a motion phantom and using a recorded data file from the RPM system. In the first technique, a rotating wheel phantom was altered by placing two plastic balls on its axis and rim, respectively. For a desired gate, the relative positions of the balls were measured from the acquired CT data and converted into corresponding phases. Phase difference was calculated between the measured phases and the desired phases. Using period of motion, the phase difference was converted into time delay. The Varian RPM system provides an external breathing signal; it also records transistor-transistor logic (TTL) ′X-Ray ON′ status signal from the CT scanner in a text file. The TTL ′X-Ray ON′ indicates the start of CT image acquisition. Thus, knowledge of the start time of CT acquisition, combined with the real-time phase and amplitude data from the external respiratory signal, provides time-stamping of all images in an axial CT scan. The TTL signal with time-stamp was used to calculate when (during the breathing cycle) a slice was recorded. Using the two approaches, the time delay between the prospective gating signal and CT simulator has been determined to be 367 ± 40 ms. The delay requires corrections both at image acquisition and while setting gates for the treatment delivery; otherwise the simulation and treatment may not be correlated with the patient′s breathing.
Evaluation of wheat by polyacrylamide gel electrophoresis
M Shuaib, M Jamal, H Akbar, I Khan, R Khalid
African Journal of Biotechnology , 2010,
Abstract: In this study 15 wheat varieties namely Nacozari-76, Ouqab, Tatar-96, Bakhtawar-92, Yecura-70, Raj, Bakkar, Sulilman-96, Pirsabak-05, Maria, Khyber-87, Fakhr-e-Sarhad, Pirsabak-04, Inqulab-91 and Rawal- 87 were evaluated for analysis of variability in seed storage proteins by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Electrophorogram for each variety were scored and presence or absence of each band noted and was entered in a binary data matrix. Based on the data of SDS-PAGE gels cluster analysis was performed to check the variations among varieties. The overall result shows low degree of heterogeneity however different varieties reveal differential protein banding pattern. It is concluded that SDS-PAGE analysis of wheat endosperm protein is useful for evaluation of genetic variability and cultivars identification that help in wheat breeding program.
Synthesis and Characterization of Lithium-Substituted Cu-Mn Ferrite Nanoparticles
M. A. Mohshin Quraishi,M. H. R. Khan
Indian Journal of Materials Science , 2013, DOI: 10.1155/2013/910762
Abstract: The effect of Li substitution on the structural and magnetic properties of LixCu0.12Mn0.88?2xFe2+xO4 (x = 0.00, 0.10, 0.20, 0.30, 0.40, and 0.44) ferrite nanoparticles prepared by combustion technique has been investigated. Structural and surface morphology have been studied by X-ray diffractometer (XRD) and high-resolution optical microscope, respectively. The observed particle size of various LixCu0.12Mn0.88?2xFe2+xO4 is found to be in the range of 9?nm to 30?nm. XRD result confirms single-phase spinel structure for each composition. The lattice constant increases with increasing Li content. The bulk density shows a decreasing trend with Li substitution. The real part of initial permeability ( ) and the grain size (D) increase with increasing Li content. It has been observed that the higher the is, the lower the resonance frequency in LixCu0.12Mn0.88?2xFe2+xO4 ferrites is. 1. Introduction Ferrite nanoparticles have attracted a growing interest due to their potential applications such as magnetic recording [1], storage [2], and biotechnology [3]. In the most recent years, the interest in the use of nanoparticles in biomedical applications has greatly increased [4, 5]. The size and composition of nanoparticles influence the bio-application of the magnetic nanoparticles [6]. It is well known that the physical and chemical properties of the nanosized magnetic materials are quite different from those of the bulk ones due to their surface effect and quantum confinement effects. These nanoparticles can be obtained through precipitation of metallic salts in different media as polymers [7], organic acid or alcohol [8], sugars [9], and so forth. In particular, sol-gel, autocombustion, thermal decomposition, hydrothermal, ball milling, reverse micelle synthesis, solid-phase reaction, thermally activated solid state reaction, and pulsed laser deposition have been developed to prepare the single-domain MnFe2O4 nanoparticles [10–23]. Manganese ferrite (MnFe2O4) nanoparticles have become very popular due to their wide range of magnetic applications, such as recording devices, drug delivery, ferrofluid, biosensors, and catalysis [10, 24–27]. Recently, Deraz and Alarifi [28] have studied structural and magnetic properties of MnFe2O4 nanoparticles by combustion route. Till now, no other report has been found in the literature for Li-doped Cu-Mn ferrite. Lithium ferrites are low-cost materials which are attractive for microwave device applications. Hence, there has been a growing interest in Li-substituted Cu-Mn ferrite for microwave applications and high permeability
Locating Mobile Phones on a City Map Using SMS Technology
R. H. Rahman,N. Nowsheen,M. A. Khan,A.H. Khan
Asian Journal of Information Technology , 2012,
Abstract: Finding the location of a mobile phone is one of the crucial challenges in modern telecommunication system. This study proposes a solution of locating a mobile phone on a city map using SMS (Short Message Service). This study intends to help mobile phone users to find out his/her location on a geographical map. The proposed method is GPS-free and it requires no additional technology to be added to existing mobile phones. It uses well-established algorithms to locate a mobile phone on a geographical map and then sends the position-on-a-map to the user mobile by an SMS.
Why Trichoderma is Considered Super Hero (Super Fungus) Against the Evil Parasites?
F.A. Mohiddin,M.R. Khan,S.M. Khan,B.H. Bhat
Plant Pathology Journal , 2010,
Abstract: Not Available
The effect of low-dose ketamine infusion on the remifentanil induced hemodynamic changes during general anesthesia
Beigmohamadi M T,Khan Z H,Mahoori A R
Tehran University Medical Journal , 2008,
Abstract: Background: Remifentanil is known to produce side-effects of hypotension and bradycardia. In this study, we examine the effect of low-dose ketamine infusion on the heart rate and blood pressure of patients anesthetized with remifentanil.Methods: In a randomized clinical trial, 54 patients aged 20-50 years old, with ASA physical status Ι, were studied in two groups (n=27), Ketamine- Remifentanil (K-R group) and Placebo- Remifentanil (P-R group). Exclusion criteria were ASA physical status >1, gastroesophageal reflux, tachycardia, bradycardia, systemic diseases, use of antihypertensive drugs, difficult intubations, risk of aspiration and contraindications of ketamine. Remifentanil was started at a rate of 0.5 μg. kg-1. min-1 and anesthesia was induced with thiopental sodium 2 mg.kg-1. Maintenance of anesthesia included halothane and nitrous oxide/oxygen mixture. Remifentanil infusion was continued in both groups at a rate of 0.5 μg.kg-1.min-1. In the K-R group, ketamine was started with an infusion rate of 10 μg.kg-1. min-1, 10 minutes after intubation, while in the P-R group, normal saline was started with the same dose of remifentanil. Heart rate, systolic, diastolic and mean arterial blood pressure were measured and compared at 1, 3, 5, 10, 15, 20, 25 and 30 minutes.Results: No significant differences were found between basic patient characteristics of mean of age, sex, weight, systolic, diastolic and mean arterial blood pressure and heart rate (p>0.2) in the two groups. However, the rate of systolic, diastolic and mean arterial blood pressure changes in the P-R group was significantly greater than that of the K-R group (p<0.006). Heart rate changes were similar between the two groups (p=0.6). Incident of severe hypotension (a decrease of more than 25% of the basic value) was less in the K-R group than that of the P-R group (11% vs. 89%; p=0.000).Conclusion: Low-dose ketamine infusion modulates the effect of remifentanil-induced hypotension and provides better hemodynamic stability during general anesthesia.
Common Fixed Points of Weakly Contractive and Strongly Expansive Mappings in Topological Spaces
M. H. Shah,N. Hussain,A. R. Khan
Journal of Inequalities and Applications , 2010, DOI: 10.1155/2010/746045
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