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Tytuł:
Power System Transient Stability Case Study: A Power Sub-Station Plant in Sudan
Autorzy:
Abbas, Asma
Kamal, Ramadan Doud
Elmustafa, Sayed Ali Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/1193487.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Dynamic Stability
GARRI power stations
Swing Equation
Transient Stability
power angle
synchronism
Opis:
Power system stability is defined by the tendency of the energy system to develop recovery forces equal or greater than the disturbing forces to maintain a stable equilibrium state. In general, power system stability problems are usually divided into two parts, steady state and transient state. An extension of steady-state stability is dynamic stability. Transient stability deals with the effects of large disturbances such as malfunctions, sudden line interruptions, and sudden application or load removal. This research is presents load angle method to transient stability problem for multi-machine system. The ETAP program is used to simulate the above method to study transient stability. A sub-station plant in Khartoum (GARRI) with four generation sections (1, 2 and 4) has been taken as a case study. The simulation result shows that when a single line-ground fault occurs at main busbar and cleared at time t = 0.4 sec the system is stable, in case 2, when the same fault cleared at t = 3 sec the system become unstable.
Źródło:
World Scientific News; 2021, 158; 267-284
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on the structural, optical and topographical behavior of Cadmium oxide polycrystalline thin films using electrochemical depositing method at different times
Autorzy:
Abd, Ahmed N.
Dawood, Mohammed O.
Hassoni, Majid H.
Hussein, Ali A.
Powiązania:
https://bibliotekanauki.pl/articles/1192094.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Cadmium oxide
thin film
optical characteristics of film
electrochemical depositing method
Opis:
The optical and structure properties of Cadmium oxide (CdO) thin film prepared by electrochemical deposition method at different times (15, 30 and 60) min were investigated in this paper. Results of optical Transmission, absorption, reflection spectra, optical conductance, refractive index, extension coefficient, real and imaginary dielectric constants studies are reported. The optical transmittance of the CdO thin film which formed at room temperature was 20% at wavelength ≈350 nm then increases to 60% at wavelength ≈1100 nm for thin film of CdO. The band-gap was also calculated from the equation relating absorption coefficient with the wavelength. The energy band gap changes from 2.3eV (Bulk CdO) to 2.45eV (CdO thin film). The plotted graphs show the optical characteristics of the film which varied with the wavelength and the photon energy. The optical conductance and band-gap indicated that the film is transmitting within the visible range. The dielectric constant and optical conductance of the film initially decreases slowly with increase in photon energy. The extinction coefficient and refractive index of the films also evaluated, which affected with the change in transmittance. The structure of synthesised CdO thin film was analyzed by X-ray diffraction XRD which revealed that the CdO thin film are polycrystalline and have several peaks of cubic face structure. The crystallite size, dislocation density, microstrain and number of dislocations of the thin film were calculated and listed.
Źródło:
World Scientific News; 2016, 37; 249-264
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural analysis of functionally graded material using sigmioadal and power law
Autorzy:
Abd-Ali, Nabel Kadum
Madeh, Ahmed Raee
Powiązania:
https://bibliotekanauki.pl/articles/1955209.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
FGM shell
sigmoidal law
power law
Hamilton’s principle
stress analysis
prawo sigmoidalne
zasada Hamiltona
analiza naprężeń
Opis:
The stress-strain relations, displacement distribution, stress resultants and mid plane strain resultants of a functionally graded material plate are studied using Hamilton’s principle. A simply supported rectangular thick shell direct stress, inplane shear stress, transverse stress and displacement are investigated. The analysis and modeling of five layers FGM shell is carried out using MATLAB19 code with ABAQUS20 software. Using distinct materials on the top and bottom layers of the shell, a transverse uniform load in five degrees - of - freedom is applied with a specific Poisson's ratio and Young's modulus in a power and sigmoidal law function through the thickness direction. A power law was used to determine the distribution of properties through shell thickness. The results showed that the bottom layer affected significantly most stress due to subjected to the most in-plane stress while the displacement is greatest at the top layer.
Źródło:
Diagnostyka; 2021, 22, 4; 59-65
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Beam Pattern Optimization Via Unequal Ascending Clusters
Autorzy:
Abdulqader, Ahmed Jameel
Mohammed, Jafar Ramadhan
Ali, Yessar E. Mohammad
Powiązania:
https://bibliotekanauki.pl/articles/2200966.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
beam pattern
clustered array
genetic algorithm
sidelobes
Opis:
In this paper, two different architectures based on completely and sectionally clustered arrays are proposed to improve the array patterns. In the wholly clustered arrays, all elements of the ordinary array are divided into multiple unequal ascending clusters. In the sectionally clustered arrays, two types of architectures are proposed by dividing a part of the array into clusters based on the position of specific elements. In the first architecture of sectionally clustered arrays, only those elements that are located on the sides of the array are grouped into unequal ascending clusters, and other elements located in the center are left as individual and unoptimized items (i.e. uniform excitation). In the second architecture, only some of the elements close the center are grouped into unequal ascending clusters, and the side elements were left individually and without optimization. The research proves that the sectionally clustered architecture has many advantages compared to the completely clustered structure, in terms of the complexity of the solution. Simulation results show that PSLL in the side clustered array can be reduced to more than −28 dB for an array of 40 elements. The PSLL was −17 dB in the case of a centrally clustered array, whereas the complexity percentage in the wholly clustered array method was 12 .5 %, while the same parameter for the partially clustered array method equaled 10%.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 1; 1--7
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consequences of Mercury Used by Artisanal and Small-Scale Gold Mining Processes a Case of River Nile State Sudan
Autorzy:
Ahmed, Ali M.A.
Purwanto, Purwanto
Sunoko, Henna Rya
Powiązania:
https://bibliotekanauki.pl/articles/124413.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
artisanal gold mining
small-scale gold mining
workers occupationally exposed
WOE
residents in surrounding communities
RSC
distribution of mercury concentration
surface soil
surface water
meteorological factors
topographical factors
Opis:
On the discovery of gold reserves in 14 states in Sudan, traditional gold mining suddenly started to flourish and hundreds of thousands of laymen became engaged in gold extraction. The new source of revenue generation added much to the empty treasury and the loss in petroleum revenue due to cessation of the south in 2011 could thus be compensated. Since gold extraction by artisanal and small-scale gold mining does not require much finance or advanced technology, it suited unskilled workers and many young people found their way into the new business. Although gold extraction generates high revenues, the use of mercury in gold extraction poses much threat to the environment and general health of miners and the surrounding areas. The research tries to investigate the effects of traditional gold mining in Alebedia area, Berber Locality in the River Nile State. The investigation includes A/ the effects of extraction methods on the environment and general health. B/ the level of education and its distribution within the miners and how it affected the awareness of the miners about the dangers of mining activities. C/ the period of stay that miners spend in the mining area its contribution on the awareness about the dangers and diseases inflicted on the miners, D/ the effects of traditional gold mining activities on natural environmental impacts and E/ the effects of the meteorological and topographical factors, the distribution and concentration of mercury in the area and their effects on the environment and general health. The research adopted the techniques of using random sampling and quantitative qualitative in addition to the analytical techniques. The research finally concluded that traditional gold mining has positive effects on the economic side and negative effects on the environment and general health.
Źródło:
Journal of Ecological Engineering; 2019, 20, 2; 106-115
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Testing the performance of a solar energy cooling system in Baghdad city
Autorzy:
Ahmed, Muna H.
Al-Salihi, Ali M.
Hussain, Hazim H.
Powiązania:
https://bibliotekanauki.pl/articles/35537880.pdf
Data publikacji:
2021
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
cool building
solar chimney
ground heat exchanger
weather conditions
Opis:
Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m3 was situated to face the geographical south. The test room is thermally insulated and connected to a solar chimney which generates a convection current to draw the air out of the room through a heat exchanger. The heat exchanger was submerged in a water tank of 2 m length, 1 m width and 1 m height. It was also covered with a layer of soil mixture with a thickness of 10 cm. The experiment simulates the natural conditions of a shallow water surface, connected to the room from the other side. The study results revealed that the air temperature inside the test room was lower than that of the ambient air outside. Pearson correlation coefficient showed that there was a strong direct relationship between solar radiation, temperature and wind speed from one side and the cooling efficiency from the other side. Also, there was a negative correlation between relative humidity and cooling efficiency.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2021, 30, 2; 283-292
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Face Recognition Comparative Analysis Using Different Machine Learning Approaches
Autorzy:
Ahmed, Nisar
Khan, Farhan Ajmal
Ullah, Zain
Ahmed, Hasnain
Shahzad, Taimur
Ali, Nableela
Powiązania:
https://bibliotekanauki.pl/articles/2024199.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
linear discriminant analysis
k-nearest neighbor
support vector machine
principal component analysis
liniowa analiza dyskryminacyjna
maszyna wektorów podporowych
analiza głównych składowych
Opis:
The problem of a facial biometrics system was discussed in this research, in which different classifiers were used within the framework of face recognition. Different similarity measures exist to solve the performance of facial recognition problems. Here, four machine learning approaches were considered, namely, K-nearest neighbor (KNN), Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), and Principal Component Analysis (PCA). The usefulness of multiple classification systems was also seen and evaluated in terms of their ability to correctly classify a face. A combination of multiple algorithms such as PCA+1NN, LDA+1NN, PCA+ LDA+1NN, SVM, and SVM+PCA was used. All of them performed with exceptional values of above 90% but PCA+LDA+1N scored the highest average accuracy, i.e. 98%.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 1; 265-272
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Lower Zab river water quality using both Canadian Water Quality Index Method and NSF Water Quality Index Method
Autorzy:
Ahmed, Sarah M.
Taha, Omer M.E.
Najemalden, Mohamed A.
Ahmed, Rehab T.
Abedulwahab, Ali A.
Powiązania:
https://bibliotekanauki.pl/articles/118599.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
NSF Water Quality Index
Canadian Water Quality Index
Lower Zab river
physicochemical parameters
dissolved oxygen
biochemical oxygen demand
Opis:
Rivers are considered the most important sources of surface water on Earth. They are play a significant role in all human activities and the quality of river water is needed. Therefore, the importance of the water quality index is arising through providing data base about quality of the water source, and explain the change in the water quality over a period of time continually. This study involved determination of physicochemical and biological parameters of Lower Zab river in Kirkuk city at two different points. The objectives of the study are to assess the present water quality, through analysis of some selected water quality parameters like pH, TDS, BOD, dissolved oxygen, turbidity, EC, alkalinity, and salinity etc. and to compare the results with the Canadian Council of Ministers of the Environment and National Sanitation Foundation Water Quality Indices. Raw water samples were collected from the Lower Zab river twice a month by one sample every 15 days from each station. The water quality data include 16 different parameters. Tests were carried out following the American Public Health Association standard methods. The results show that all parameters values were within the standards of drinking water proposed by the CCME standards and Iraqi standards or the World Health Organization standards for drinking purpose, except turbidity, DO, nitrate, calcium, which were mostly higher than the standards and sometimes BOD and potassium. The results of WQI showed that the water quality at LZ3 station is lower than LZ2 station due to the polluting activity of the Lower Zab river. Furthermore, for the years 2014, 2015, and 2016, the water quality was degraded due to the ISIS war. Also, it was noted in the 2013 year that the water quality degraded more in fall and winter seasons due to that the earth has exposed to the long-dried season and then suddenly exposed to a high rainfall season which in turns leads to increase some parameters very high (i.e. turbidity). Finally, the Lower Zab river water cannot be use for drinking directly. However, a pretreatment is needed before the drinking use.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2020, 29, 2; 155-171
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Etiology and pathology of epidemic outbreaks of avian influenza H5N1 infection in Egyptian chicken farms
Autorzy:
Ali, A.
Elmowalid, G.
Abdel-Glili, M.
Sharafeldin, T.
Abdallah, F.
Mansour, F.
Nagy, A.
Ahmed, B.
Abdelmoneim, M.
Powiązania:
https://bibliotekanauki.pl/articles/30849.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Epidemic outbreaks of avian influenza (AI) virus H5N1 have been frequently reported in Egypt during the last nine years. Here we investigate the involvement of AI H5N1 in outbreaks of acute respiratory disease that occurred in several commercial chicken farms in Egypt in 2011, and we describe to the pathology caused by the virus in the course of the outbreak. Twenty-one chicken farms with history of acute respiratory symptoms and high mortalities were screened for AI H5N1. Virus identification was based on hemagglutination inhibition test, and PCR detection and sequencing of the hemagglutinin and neuraminidase genes. Virus distribution was determined by immunohistochemical staining of AI antigens in organs of infected birds. Standard H&E staining was performed for histological examination of affected organs. Eighty-one % of the examined birds, representing 100% of the screened farms, were positive for AI H5N1 virus. Phylogenetic analysis of the hemagglutinin and neuraminidase genes of the isolated virus reveals its affiliation to clade 2.2.1. Viral antigens were localized in the endothelial cells of the heart, liver, lungs and skin, where pathological lesions including congestion, hemorrhages, multifocal inflammation and necrosis were concurrently observed. According to the pattern of the viral antigen and lesion distribution in the visceral organs, we suggest cardiovascular and circulatory failures as the probable cause of death during these outbreaks. In conclusion, the present study further confirms the epidemic status of AI H5N1 virus in Egypt and reveals the highly pathogenic nature of the local isolates.
Źródło:
Polish Journal of Veterinary Sciences; 2015, 18, 4
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Novel approach for big data classification based on hybrid parallel dimensionality reduction using spark cluster
Autorzy:
Ali, Ahmed Hussein
Abdullah, Mahmood Zaki
Powiązania:
https://bibliotekanauki.pl/articles/305766.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
big data
dimensionality reduction
parallel processing
Spark
PCA
LDA
Opis:
The big data concept has elicited studies on how to accurately and efficiently extract valuable information from such huge dataset. The major problem during big data mining is data dimensionality due to a large number of dimensions in such datasets. This major consequence of high data dimensionality is that it affects the accuracy of machine learning (ML) classifiers; it also results in time wastage due to the presence of several redundant features in the dataset. This problem can be possibly solved using a fast feature reduction method. Hence, this study presents a fast HP-PL which is a new hybrid parallel feature reduction framework that utilizes spark to facilitate feature reduction on shared/distributed-memory clusters. The evaluation of the proposed HP-PL on KDD99 dataset showed the algorithm to be significantly faster than the conventional feature reduction techniques. The proposed technique required >1 minute to select 4 dataset features from over 79 features and 3,000,000 samples on a 3-node cluster (total of 21 cores). For the comparative algorithm, more than 2 hours was required to achieve the same feat. In the proposed system, Hadoop’s distributed file system (HDFS) was used to achieve distributed storage while Apache Spark was used as the computing engine. The model development was based on a parallel model with full consideration of the high performance and throughput of distributed computing. Conclusively, the proposed HP-PL method can achieve good accuracy with less memory and time compared to the conventional methods of feature reduction. This tool can be publicly accessed at https://github.com/ahmed/Fast-HP-PL.
Źródło:
Computer Science; 2019, 20 (4); 411-429
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Electrical Properties for Cantilever-Based Piezoelectric Energy Harvester
Autorzy:
Ali, Ahsan
Pasha, Riffat Asim
Sheeraz, Muhammad Abdullah
Butt, Zubair
Elahi, Hassan
Khan, Afzaal Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/102729.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
piezoelectric
micro-electromechanical systems
energy harvesting
microsystems
bimorph
systemy mikroelektromechaniczne
zbieranie energii
mikrosystemy
bimorf
Opis:
In the present era, the renewable sources of energy, e.g., piezoelectric materials are in great demand. They play a vital role in the field of micro-electromechanical systems, e.g., sensors and actuators. The cantilever-based piezoelectric energy harvesters are very popular because of their high performance and utilization. In this research-work, an energy harvester model based on a cantilever beam with bimorph PZT-5A, having a substrate layer of structural steel, was presented. The proposed energy scavenging system, designed in COMSOL Multiphysics, was applied to analyze the electrical output as a function of excitation frequencies, load resistances and accelerations. Analytical modeling was employed to measure the output voltage and power under pre-defined conditions of acceleration and load resistance. Experimentation was also performed to determine the relationship between independent and output parameters. Energy harvester is capable of producing the maximum power of 1.16 mW at a resonant frequency of 71 Hz under 1g acceleration, having load resistance of 12 kΩ. It was observed that acceleration and output power are directly proportional to each other. Moreover, the investigation conveys that the experimental results are in good agreement with the numerical results. The maximum error obtained between the experimental and numerical investigation was found to equal 4.3%.
Źródło:
Advances in Science and Technology. Research Journal; 2019, 13, 3; 76-85
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancement of Quinoa Grain Yield and Nutritional Quality by Potassium Fertilization Combined with Foliar Spraying of Seaweed Extract
Autorzy:
Ali, El-Sayed El-Shahat El-Sayed
El-Samad, Emad El-Din Hassanein Abd
Abdelaal, Hala Ahmed
AbouSekken, Mahmoud Saad
Powiązania:
https://bibliotekanauki.pl/articles/24201648.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Chenopodium quinoa
grain yield
weight of 1000-grain
grain size
grain mineral content
grain nutritional profile
Opis:
The current work was carried out during the two growing seasons of 2016/2017 and 2017/2018 at the Experimental Station of the Environmental Studies and Research Institute, University of Sadat City, Sadat City, Menofia Governorate, Egypt. It aimed to investigate the effect of applying potassium fertilizer at 90, 140 and 190 kg K2O/ha combined with spraying applications of seaweed extract for four times in a 15-day interval starting at 40 days after sowing at rates of 0.0, 1.5 and 3.0 ml/L on the yield, mineral contents and nutritional quality of quinoa grains cv. CICA. A split-plot design was used in three replicates. Results reported that by increasing the application of potassium from 90 to 190 kg K2O/ha, gradual increases in all studied parameters of quinoa grains occurred in the seasons of 2016–2017 and 2017–2018, except for class B grain, Mg and fiber contents. Potassium application at 190 kg K2O/ha gave the highest significant values of all determined parameters in comparison with treatment of 90 kg K2O/ha. In most cases, insignificant differences were detected between potassium fertilizer levels of 140 and 190 kg K2O/ha. Spraying seaweed extract at 3.0 ml/L resulted in superiority of all studied characters except class B grain, Mg and fiber contents, followed by 1.5 ml/L treatment with insignificant differences between them in most cases. There were significant differences among spraying seaweed treatments on Ca, Fe, Mn, protein and fiber contents in both seasons, N, P and K during the first season, and grain yield/plant, total grain yield/ha and Zn content during the second season. The interaction between potassium fertilization levels and spraying applications of seaweed extract had significantly different effects on all studied characters during both seasons, except for Mg percentage. It is evident that the application of potassium fertilization at 140 or 190 kg K2O/ha combined with the spraying of seaweed extract at 3.0 ml/L caused an apparent enhancement of the yield, mineral contents and nutritional quality of quinoa grains during the two experimental seasons.
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 341--356
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The isotherm and kinetic studies of the biosorption of heavy metals by non-living cells of Chlorella vulgaris
Autorzy:
Ali, Mohamed H.
Hussian, Abd-Ellatif M.
Abdel-Satar, Amaal M.
Goher, Mohamed E.
Napiórkowska-Krzebietke, Agnieszka
El-Monem, Ahmed M. Abd
Powiązania:
https://bibliotekanauki.pl/articles/962750.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Opis:
In general, the biosorption of heavy metals by various types of non-living organisms appears to be a very effective, low-cost and innovative method for their removal from aquatic environments. The aim of this study was to determine the applicability of adsorption isotherms and kinetic models during the biosorbent activity of non-living Chlorella to the removal of Cd, Cu and Pb. Dead cells of Chlorella vulgaris were used to remove these heavy metals from aqueous solution in experimental conditions, i.e. under various condition of pH, biosorbent dosage and contact time. Afterwards, the Langmuir and Freundlich adsorption isotherm models and the sorption kinetic (pseudo-first and pseudo-second order models, and intraparticle diffusion) were applied to the experimental data to check the effectiveness of the removal process. The removal of heavy metals on C. vulgaris following the order of Pb+2 > Cu+2 > Cd+2 was confirmed by the maximum biosorption capacities (qmax), the Langmuir constant (b), separation factor (RL) and Freundlich intensity parameter (1/n) values. The equilibrium data were well fitted with the Langmuir and Freundlich isotherm models. The adsorption process followed the pseudo-second-order model and it suggested that such kinetics is the most effective. The present results confirmed highly efficient biosorbent activity of C. vulgaris in the removal of heavy metals, especially Cd, Cu and Pb, from aqueous solution. The environmentally friendly origin indicates that non-living cells of C. vulgaris could find many broad-scale, cost-effective and alternative applications.
Źródło:
Journal of Elementology; 2016, 21, 4
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leczenie choroby zwyrodnieniowej stawu biodrowego przy zastosowaniu iniekcji osocza bogatopłytkowego pod kontrolą ultrasonograficzną: systematyczny przegląd piśmiennictwa
The use of ultrasound-guided platelet-rich plasma injections in the treatment of hip osteoarthritis: a systematic review of the literature
Autorzy:
Ali, Mohammed
Mohamed, Ahmed
Elamin Ahmed, Hussam
Malviya, Ajay
Atchia, Ismael
Powiązania:
https://bibliotekanauki.pl/articles/1032150.pdf
Data publikacji:
2018
Wydawca:
Medical Communications
Tematy:
osocze bogatopłytkowe
Opis:
Purpose: This review aims to determine whether ultrasound-guided platelet-rich plasma injection has any role in improving clinical outcomes in patients with hip osteoarthritis. Methods: A search of the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool was conducted. The PubMed database was also utilised to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. The Preferred Reporting Items for Systematic Review and Meta-Analysis methodology guidance was employed and a quality assessment was performed using the Jadad score. Results: Three randomised clinical trials met the inclusion criteria and were included for analysis. All three trials were of good quality based on the Jadad score. A total of 115 patients out of 254 received platelet-rich plasma injections under ultrasound guidance. The platelet-rich plasma recipient group included 61 males and 54 females with an age range from 53 to 71 years. Outcome scores show an improvement of symptoms and function maintained up to 12 months following platelet-rich plasma injection. Conclusions: Literature to date concludes that intra-articular platelet-rich plasma injections of the hip, performed under ultrasound guidance to treat hip osteoarthritis, are well tolerated and potentially efficacious in delivering long-term and clinically significant pain reduction and functional improvement in patients with hip osteoarthritis. Larger future trials including a placebo group are required to further evaluate these promising results. Level of evidence: Level I, a systematic review of level I studies.
Cel: Celem przeglądu jest ustalenie, czy iniekcja osocza bogatopłytkowego pod kontrolą ultrasonograficzną przyczynia się do poprawy wyników klinicznych u pacjentów z chorobą zwyrodnieniową stawu biodrowego. Metody: Przeszukano bazę danych National Institute for Health and Care Excellence przy użyciu narzędzia Healthcare Databases Advanced Search. Wykorzystując bazę danych PubMed, przeszukano również: Medical Literature Analysis and Retrieval System Online, Excerpta Medica, Cumulative Index of Nursing and Allied Health Literature oraz Allied and Complementary Medicine Database. Zastosowano metodologię zgodną z deklaracją Preferred Reporting Items for Systematic Review and Meta-Analysis, a ocenę jakości badań przeprowadzono przy wykorzystaniu skali Jadada. Wyniki: Trzy randomizowane badania kliniczne spełniły kryteria włączenia do przeglądu i zostały uwzględnione w analizie. Na podstawie wyników w skali Jadada stwierdzono, że wszystkie trzy badania odznaczały się wysoką jakością. Łącznie 115 spośród 254 uczestniczących w badaniach pacjentów otrzymało iniekcje z osocza bogatopłytkowego pod kontrolą ultrasonograficzną. Grupa osób leczonych osoczem bogatopłytkowym liczyła 61 mężczyzn i 54 kobiety w przedziale wiekowym od 53 do 71 lat. Wyniki oceny wskazują na zmniejszenie nasilenia objawów i poprawę stanu czynnościowego stawu, które utrzymywały się do 12 miesięcy od iniekcji osocza bogatopłytkowego. Wnioski: Jak wskazuje dostępne piśmiennictwo, iniekcje osocza bogatopłytkowego podawane dostawowo pod kontrolą ultrasonograficzną w leczeniu choroby zwyrodnieniowej stawu biodrowego są dobrze tolerowane i potencjalnie skuteczne pod względem długotrwałego i istotnego klinicznie ograniczania dolegliwości bólowych i poprawy stanu czynnościowego stawu. W celu bardziej szczegółowej oceny tych obiecujących wyników niezbędne są zakrojone na większą skalę badania z uwzględnieniem grupy placebo. Poziom dowodów: Poziom I, systematyczny przegląd badań poziomu I.
Źródło:
Journal of Ultrasonography; 2018, 18, 75; 332-337
2451-070X
Pojawia się w:
Journal of Ultrasonography
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola ultrasonografii w rozpoznawaniu utajonych złamań kości łódeczkowatej
The role of ultrasonography in the diagnosis of occult scaphoid fractures
Autorzy:
Ali, Mohammed
Ali, Mujtaba
Mohamed, Ahmed
Mannan, Syed
Fallahi, Farshid
Powiązania:
https://bibliotekanauki.pl/articles/1032202.pdf
Data publikacji:
2018
Wydawca:
Medical Communications
Tematy:
złamanie kości łódeczkowatej
Opis:
Background: Ultrasonography is widely utilized by emergency physicians and radiologists to diagnose various orthopaedic diseases, including fractures. We aim to derive a definitive estimate of the diagnostic accuracy of ultrasonography in clinically suspected scaphoid fractures. Methods: We undertook a systematic review and meta-analysis of included diagnostic cohort studies that discussed the use of ultrasonography in the diagnosis of occult scaphoid fractures. We searched the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool. In addition, we utilized the PubMed database to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. Studies were included if they discuss the role of ultrasound imaging in the diagnosis of scaphoid fractures based on cortical interruption, radio-carpal effusion and scapho-trapezium-trapezoid effusion. Quality assessment was performed using the methodological index for non-randomized studies scoring system. Results: 6 non-randomized control studies met the inclusion criteria. Collectively, these included 236 patients with a mean age ranging from 18 to 41.2 years. The quality of these articles ranged between moderate and high based on the methodological index for nonrandomized studies score. The mean sensitivity was 88.95% (standard deviation 10.03) and mean specificity was 89.50% (standard deviation 12.21). Conclusion: The current literature reveals high sensitivity and specificity in the use of ultrasonography in scaphoid fracture diagnosis. However, multiple factors including technical differences in ultrasound machines and probes, small sample sizes and variability of subsequent confirmatory tests have created a challenge in determining the ultimate reliability of ultrasonography in the diagnosis of occult scaphoid fractures. Considering these factors and limitations, large-sample and high-quality clinical trials are needed to adequately assess its reliability for this purpose. One stop clinics, in the authors’ opinion, would be an ideal setting for its introduction as well as for future trials.
Wprowadzenie: Ultrasonografia jest szeroko wykorzystywana w medycynie ratunkowej i radiologii do diagnozowania różnych schorzeń narządu ruchu, w tym złamań. Celem pracy jest jednoznaczne ustalenie stopnia dokładności badania ultrasonograficznego w przypadku klinicznego podejrzenia złamania kości łódeczkowatej. Metody: W pracy podjęto się przeglądu systematycznego i metaanalizy wybranych badań kohortowych, które dotyczą wykorzystania ultrasonografii w rozpoznawaniu utajonych złamań kości łódeczkowatej. Przeszukano bazę National Institute for Health and Care Excellence z wykorzystaniem narzędzia wyszukiwania Healthcare Databases Advanced Search. Wykorzystano również bazę PubMed do przeszukania baz danych Medical Literature Analysis and Retrieval System Online, Excerpta Medica, Cumulative Index of Nursing and Allied Health oraz Allied and Complimentary Medicine Database. Do analizy włączano te badania, które dotyczą roli badania ultrasonograficznego w rozpoznawaniu złamań kości łódeczkowatej na podstawie przerwania ciągłości istoty zbitej, wysięku w stawie promieniowo-nadgarstkowym oraz wysięku w stawie łódeczkowato-czworobocznym. Oceny jakości analizowanych prac dokonywano na bazie klasyfikacji punktowej badań nierandomizowanych. Wyniki: Kryteria włączenia spełniło 6 badań porównawczych bez randomizacji. Badania te obejmowały łącznie 236 pacjentów o średniej wieku od 18 lat do 41,2 roku. Jakość artykułów wahała się pomiędzy średnią a wysoką na podstawie wyniku w klasyfikacji punktowej badań nierandomizowanych. Średnia czułość badania w analizowanych pracach wynosiła 88,95% (odchylenie standardowe: 10,03), a średnia swoistość 89,50% (odchylenie standardowe: 12,21). Wnioski: Najnowsze doniesienia literaturowe mówią o wysokiej czułości i swoistości badania ultrasonograficznego w rozpoznawaniu złamania kości łódeczkowatej. Ustalenie wiarygodności badania ultrasonograficznego w rozpoznawaniu utajonych złamań kości łódeczkowatej jest jednak trudne ze względu na liczne czynniki, takie jak różnice techniczne pomiędzy stosowanymi aparatami i głowicami ultrasonograficznymi, niska liczebność badanych prób oraz różnice w typie badania stosowanego do potwierdzenia rozpoznania. Ze względu na te czynniki i ograniczenia do właściwej oceny wiarygodności badania ultrasonograficznego stosowanego do omawianego celu potrzebne są badania kliniczne wysokiej jakości. Według autorów ośrodki kompleksowej diagnostyki typu „one stop clinic” byłyby idealnym miejscem na wprowadzenie badań ultrasonograficznych do diagnostyki złamań kości łódeczkowatej oraz na prowadzenie badań klinicznych w przyszłości.
Źródło:
Journal of Ultrasonography; 2018, 18, 75; 325-331
2451-070X
Pojawia się w:
Journal of Ultrasonography
Dostawca treści:
Biblioteka Nauki
Artykuł
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