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Wyszukujesz frazę "Ahmed, A. S." wg kryterium: Autor


Tytuł:
Radiation doses to technologists working with 18F-FDG in a PET center with high patient capacity
Autorzy:
Demir, M.
Demir, B.
Yaşar, D.
Sayman, H. B.
Halac, M.
Ahmed, A. S.
Özcan, K.
Uslu, I.
Powiązania:
https://bibliotekanauki.pl/articles/148501.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
whole-body dose
finger doses
personnel dosimetry
18F-FDG
PET-CT
Opis:
The increasing numbers of PET studies for routine diagnosis creates a real hazard to radiation workers. The aim of this study is to estimate the annual whole-body and finger radiation dose to technologists working with 18F-FDG in a PET center with high patient potential. In our PET center, the number of PET imaging has increased almost to 5000 studies per year. Our standard dose for tumor imaging is 518 MBq of 18F-FDG. Five technologists performing all steps of 18F-FDG imaging (5 patients per technologist in a day) were officially involved round the week for handling and injecting 18F-FDG to patients. Whole-body and finger dose measurements with TLDs were performed for two different time periods: i) before shielding precautions during the first 6 months (without a shielding for sterile syringe and without a lead container for shielded syringe) and ii) after shielding precautions during the next 6 months (with a shielding for sterile syringe and with a lead container for shielded syringe). The average annual whole-body radiation dose for one technologist before shielding precautions was 7.82 mSv and after shielding precautions was 5.76 mSv. On the other hand, while the average annual finger radiation doses for one technologist before shielding precautions were 210.36 and 293.72 mSv for the left and right hand, after shielding precautions were they 158.16 and 217.58 mSv for the left and right hand, respectively. According to our results, if one technologist performs the whole-body PET imaging of 5 patients per day, the annual radiation dose to this technologist will not exceed the recommended limits by ICRP.
Źródło:
Nukleonika; 2010, 55, 1; 107-112
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-source energy networks for cargo Vessels
Autorzy:
Ahmed, S.
Castellazzi, A.
Williams, A.
Powiązania:
https://bibliotekanauki.pl/articles/136252.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
ship
energy management
renewable energy
solar
marine
storage
Opis:
The paper discusses the feasibility of installing renewable energy generation technologies on sea-going transport, taking into account the additional weight and power consumption. This study in based on the power management of a 26,198 tonne commercial chemical tanker. The management system would aim at reducing the number of generators as well as the power required from burning fossil fuels. After a process of elimination of potential technologies based on feasibility of the project and shipboard application, the work is focused towards photovoltaic and wind energy generation in combination with fossil fueled engines and Li-ion battery storage covering the higher energy density needs, and the intermittent nature of renewables. The network architecture is optimized in order to have the highest efficiency, and reduced system weight. The results show that successful management of the system can lead to reduction in generator requirement, and energy despite the weight of extra installations of photovoltaic and wind energy generation systems. By reducing the number of generators and allowing each remaining one to operate near their maximum power, the specific fuel consumption is improved, the efficiency is increased, resulting in significant fuel and cost saving, along with the mass of fuel to be carried on-board.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 4; 37-43
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microbial degradation of lignocellulosic biomass: discovery of novel natural lignocellulolytic bacteria
Autorzy:
Ahmed, S.
Rahman, S.
Hasan, M.
Paul, N.
Sajib, A.A.
Powiązania:
https://bibliotekanauki.pl/articles/81125.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
lignocellulose
microbial degradation
biofuel
cellulose
lignin
hemicellulose
lignocellulolytic bacteria
Chryseobacterium gleum
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3-Dimensional Surface Magnetic Susceptibility Distributions with Depth to Investigate Anthropogenic Pollutants Boundary in Abuja Metropolis
Autorzy:
Jatto, S. S.
Sule, P. O.
Ahmed, L. A.
Powiązania:
https://bibliotekanauki.pl/articles/184649.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
vertical distribution
soil pollution
magnetic susceptibility
anthropogenic pollutants
Abuja
Opis:
Changes in the magnetic susceptibility of topsoil, especially in urban areas, are greatly affected by the deposition of anthropogenic metallic dust arising from industrial activities, the burning of fossil fuels, car wear, and tyre abrasion. In this study, magnetic susceptibility measurements were carried out in vertical soil profiles of 30.0 cm depth from the surface at 10.0 cm intervals in about 431 locations within the Abuja metropolis with a view to investigate the penetration ability of magnetic pollutants in the ground. From the obtained data, 3-D surface contour maps were plotted for different depths. The results show a magnetic susceptibility decrease from the surface down the ground to the depth of 30.0cm; most of the recorded susceptibilities were of an anthropogenic origin rather than pedogenic activities. This indicates that the anthropogenic dust depositions are mostly a surface phenomenon and may therefore not pose a risk to groundwater aquifers and near surface wells.
Źródło:
Geology, Geophysics and Environment; 2016, 42, 4; 443-448
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of wood-derived biochar on the hydraulic characteristics of compacted soils: Its influence on simulated farmland carbon sequestration
Autorzy:
Ahmed, A.
Kurian, J.
Satyanarayana, S.
Raghavan, V.
Powiązania:
https://bibliotekanauki.pl/articles/2083067.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
soil biochar mixture
water retention
pore-size
distribution
hydraulic conductivity
carbon sequestration
Opis:
The addition of biochar is often proposed to increase agricultural soil quality and crop yield, while at the same time sequestering carbon from the atmosphere to help mitigate global climate change. In this research, the pore-size distribution, and saturated hydraulic conductivity of sandy loam and clay loam soils amended with varying dosages (0-10% dry basis) and two different particle sizes (0.5-420 μm (PS1) or 421-841 μm (PS2)) of wood-derived biochar were investigated under compacted conditions (5, 10, or 15 standard Proctor rammer blows (5B, 10B, or 15B, respectively)). In the 5B compacted SL (SL-5B) soil, the volume of the soil fissures and transmission pores decreased, while the volume of the storage pores (SP) increased with increasing wood-derived biochar dosage. 23.1±0.9% of the volume of the 5B compacted clay loam (CL-5B) are storage pores, this value increased to 27.4±2.0% upon amendment with 10% PS1. The saturated hydraulic conductivity of the sandy loam-5B soil amended with 10% PS1 decreased from 6.8±0.3 to 0.80±0.03 mm h-1. The sandy loam farmland C emissions decreased by 0.071 tC ha-1 y-1, whereas CL farmland C emissions decreased by 0.091 tC ha-1 y-1.
Źródło:
International Agrophysics; 2021, 35, 2; 167-177
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving mechanical properties of epoxy by adding multi-wall carbon nanotube
Autorzy:
Fadhil, B. M.
Ahmed, P. S.
Kamal, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/279975.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
multiwall carbon nanotubes
mechanical properties and nanocomposites
Opis:
In this research, multi-walled carbon nanotubes (MWCNTs) are used as the reinforcement in an epoxy resin with weight percentages (0, 0.2, 0.4, 0.6, 0.8, 1)wt%, respectively, by using both direct (nonhomogeneous) and homogeneous dispersion mixing processes to prepare (epoxy/MWCNTs) nanocomposites. Tensile and drop weight impact tests are used to evaluate mechanical properties of the composites. Results show that homogeneous dispersion has a great effect on enhancing mechanical properties of multi-wall carbon nanotube reinforced composites. Adding 0.2 wt% of MWCNTs enhances and increases tensile properties, and adding 0.6 wt% of MWCNTs enhances impact properties.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 551-560
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sequential Pattern Discovery Algorithm for Malaysia Rainfall Prediction
Autorzy:
Ahmed, A.
Bakar, A.
Hamdan, A.
Syed Abdullah, S.
Jaafar, O.
Powiązania:
https://bibliotekanauki.pl/articles/1402374.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
92.40.Zg
92.60.Wc
Opis:
This study proposes a sequential pattern mining algorithm to discover sequential patterns of Malaysia rainfall data for prediction. The apriori based algorithm is employed to find the sequential patterns from the time series data. The frequent episodes of rainfall sequences are discovered and classified by the expert into four main events namely, No rain, Light, Moderate and heavy. The sequential rules of ten rainfall stations from the duration of 33 years are analysed. The proposed algorithm is able to generate higher confidence and support of frequent and sequential patterns. Generally, the proposed study has shown its potential in producing methods that manage to preserve important knowledge and thus reduce information loss in weather prediction problem.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-324-B-326
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential toxicity assessment of novel selected pesticides against sand termite, Psammotermes hypostoma Desneux workers (Isoptera: Rhinotermitidae) under field conditions in Egypt
Autorzy:
Ahmed, M.A.I.
Eraky, E.-S.A.
Mohamed, M.F.
Soliman, A.-A.S.
Powiązania:
https://bibliotekanauki.pl/articles/66459.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The sand termite, Psammotermes hypostoma Desneux is a major pest in the New Valley Governorate, Egypt. Great efforts have been taken to control the pest. We evaluated the toxicity of four selected neonicotinoids [acetamiprid (20% SP), imidacloprid (20% SL), thiamethoxam (18.6% SC), and thiamethoxam (40% WG)], and one organophosphate pesticide [chlorpyrifos (48% EC)] against P. hypostoma workers. The investigation was done under field conditions, using the palm fronds method. However, the reduction percentages in palm fronds was recorded as the height of the sandy clay formed by termite workers on palm frond surfaces, when the fronds had been treated with a different concentration of each pesticide. The results were recorded after 15, 30, 45, and 60 days. Chlorpyrifos (48% EC) was considered the most potent pesticide among all the pesticides tested, but acetamiprid (20% SP) was considered the most toxic among the neonicotinoid pesticides tested. Moreover, the formulation of thiamethoxam (18.6% SC) was more powerful than thaimethoxam (40% WG). Furthermore, the reduction percentages on palm fronds increased significantly with an increase of the exposure period (from 15 to 60 days), as a result of the surface foraging activity of the sand termite workers. These results are given as unique and encouraging trends in controlling sand termites in Egypt.
Źródło:
Journal of Plant Protection Research; 2015, 55, 2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of non-linear shock absorbers-boundary value problem analysis
Autorzy:
Rahman, M. A.
Ahmed, U.
Uddin, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/265424.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
amortyzator
tłumik drgań
stabilność
wartość graniczna
shock absorber
untuned vibration damper
frequency ratios
non-linear springs
non-linear dampers
stability
boundary value problem
multisegment method of integration
Opis:
A nonlinear boundary value problem of two degrees-of-freedom (DOF) untuned vibration damper systems using nonlinear springs and dampers has been numerically studied. As far as untuned damper is concerned, sixteen different combinations of linear and nonlinear springs and dampers have been comprehensively analyzed taking into account transient terms. For different cases, a comparative study is made for response versus time for different spring and damper types at three important frequency ratios: one at r = 1, one at r > 1 and one at r <1. The response of the system is changed because of the spring and damper nonlinearities; the change is different for different cases. Accordingly, an initially stable absorber may become unstable with time and vice versa. The analysis also shows that higher nonlinearity terms make the system more unstable. Numerical simulation includes transient vibrations. Although problems are much more complicated compared to those for a tuned absorber, a comparison of the results generated by the present numerical scheme with the exact one shows quite a reasonable agreement.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 793-814
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the carbon sequestration capacity of arid mangroves along nutrient availability and salinity gradients along the Red Sea coastline of Saudi Arabia
Autorzy:
Shaltout, K.H.
Ahmed, M.T.
Alrumman, S.A.
Ahmed, D.A.
Eid, E.M.
Powiązania:
https://bibliotekanauki.pl/articles/48145.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
carbon sequestration
coastal wetland
mangrove
climate change
nutrient availability
salinity gradient
Red Sea
Saudi Arabia
Źródło:
Oceanologia; 2020, 62, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic diversity in fruit nutritional composition, anthocyanins, phenolics and antioxidant capacity of plum (Prunus domestica) genotypes
Genetyczna różnorodność w składzie odżywczym owoców, antocyjaniny, fenole oraz zdolność antyoksydacyjna genotypów śliwy (Prunus domestica)
Autorzy:
Nisar, H.
Ahmed, M.
Anjum, M.A.
Hussain, S.
Powiązania:
https://bibliotekanauki.pl/articles/11543260.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
genetic diversity
fruit
nutritional composition
anthocyanin
phenolics
antioxidant capacity
plum
Prunus domestica
genotype
biochemical analysis
biodiversity
proximate composition
Opis:
In the present work, genetic diversity in nutritional composition of sixteen plum genotypes growing at four different locations of Tehsil Rawalakot, District Poonch of Azad Jammu and Kashmir (Pakistan) were studied. Various parameters like moisture, dry matter, ash and total soluble solids contents, acidity, pH, vitamin C and sugar content, shelf-life and sensory/organoleptic evaluation, anthocyanins, phenolics and antioxidant activity were evaluated and variation in these characteristics has been discussed. The results suggested that the genotypes differed in their nutritional composition of fruits, anthocyanin and phenolic contents and antioxidant activity of fruit. The results of the present study regarding the nutritional status of existing plum germplasm will contribute and increase our knowledge about the genus Prunus and broaden the gene pool available for future plant breeding programs.
Badano różnorodność genetyczną w składzie odżywczym szesnastu genotypów śliw rosnących w różnych miejscach Tehsil Rawalakot, Dystrykt Poonch w Azad Jammu i Kashmirze (Pakistan). Oceniono różne parametry, takie jak wilgotność, zawartość popiołu, suchej masy i całkowitą zawartość rozpuszczalnych substancji stałych, kwasowość, pH, zawartość witaminy C, cukru, antocyjanów i fenoli, okres trwałości, cechy sensoryczne/organoleptyczne, a także omówiono zróżnicowanie tych cech. Na podstawie wyników można stwierdzić, że genotypy różniły się składem odżywczym, zawartością antocyjan i fenoli oraz zdolnością antyoksydacyjną owoców. Wyniki badania dotyczące składników odżywczych istniejącej germplazmy przyczynią się do pogłębienia wiedzy na temat gatunku Prunus oraz poszerzą pule genową dostępną dla przyszłych programów hodowli roślin.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2015, 14, 1; 45-61
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Celestite upgrading by jigs in presence of steel balls as ragging material
Autorzy:
Sobhy, Ahmed
El-Midany, Ayman A.
Ibrahim, Susan S.
Powiązania:
https://bibliotekanauki.pl/articles/1447020.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
celestite
calcite
jigging
ragging material
gravity separation
statistical analysis
Opis:
Gravity separation using jigs is widely used for coarse particle sizes separation. However, fine sizes reduce jig performance. In this study, the upgrading of celestite ore by jig was investigated at different size fractions in the presence of ragging material. Three size fractions, i.e., -15+2 mm, - 2.0 + 0.50 mm and - 0.50 + 0.08 mm were used. The steel balls were used, as ragging material, to improve the separation of fines as well as to improve the concentrate quality. The statistical design was used to correlate celestite grade and recovery with studied operating variables, i.e., the ragging number of layers, ragging balls diameter, and separation time, at a fixed water flow rate and stroke length. The design results indicated that the ragging balls diameter and their number of layers play an important role. The smaller the ragging balls diameter and the higher the ragging number of layers are the better the concentrate grade but the longer the separation time. A celestite concentrate of (> 95% SrSO4) with 74.5% recovery was obtained for - 2.0 + 0.50 mm size fraction at the optimum conditions; i.e., 3.1 mm ragging balls diameter, one ragging layers, and 15 minutes separation time.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 5; 118-128
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Improved Downlink MC-CDMA System for Effcient Image Transmission
Autorzy:
Bendelhoum, M. S.
Djebbari, A.
Boukli-Hacene, I.
Taleb-Ahmed, A.
Powiązania:
https://bibliotekanauki.pl/articles/308187.pdf
Data publikacji:
2017
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
data compression
MC-CDMA
MSSIM
performance evaluation
PSNR
SNR
SPIHT
Opis:
Image compression is an essential stage of the data archiving and transmitting process, as it reduces the number of bits and the time required to complete the transmission. In this article, a study of image transmission over the Multi-Carrier Code Division Multiple Access (MC-CDMA) downlink system is presented. The solution proposed relies on source coding combined with channel coding. The Discrete Wavelet Transform (DWT) method is used in conjunction with the SPIHT coder to compress the image, then the data generated is transmitted with the MC-CDMA technique over a noisy channel. The results show that image transmissions performed over MC-CDMA using the SPIHT model are better than the traditional approach like MC-CDMA in the AWGN channel.
Źródło:
Journal of Telecommunications and Information Technology; 2017, 4; 5-16
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation after a direct contact of flotation reagents with carbonate particles. Part 1, Model investigations
Autorzy:
Ahmed, H. A. M.
Aljuhani, M. S.
Drzymala, J.
Powiązania:
https://bibliotekanauki.pl/articles/109753.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphates
flotation
microemulsion
separation Introduction
Opis:
Carbonate fluorapatite (francolite), calcite and dolomite separately, as well as their model mixtures, were subjected to flotation after conditioning the particles with microemulsion consisting of 20% of Custafloat AR27 (collector, blend of fatty acid soaps and sulfates), 55% fuel oil #5 and 25% water at 70% solids density and subsequent pulp dilution with water to 25% solids. The best separation of carbonate fluorapatite from calcite and dolomite occurred at pH 8.5 and microemulsion dose between 0.9 and 1.5 kg/Mg, 1.5 min conditioning time and 2 minutes of flotation time. The obtained flotation concentrates using 1.5 kg/Mg of collector contained 84% carbonate fluorapatite (34% P2O5) with 84% recovery. The 84/84 separation efficiency in terms of grade-recovery indices points to promising results which can be obtained for real phosphate ores.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 713-723
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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