Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Ahmed, Ali" wg kryterium: Autor


Tytuł:
The stress analysis effect on structural health monitoring in functionally graded shell
Autorzy:
Madeh, Ahmed Raee
Abd-Ali, Nabel Kadum
Powiązania:
https://bibliotekanauki.pl/articles/2096204.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
health monitoring
FG shell
power law
sigmoidal law
virtual energy method
thickness ratio
monitorowanie konstrukcji
prawo energetyczne
prawo sigmoidalne
Opis:
The common damage in engineering structures, especially in functionally graded materials, such as failure resulting from fiber breaking or cracking in the matrix or deboning between fibers and matrix, as well as the delamination between the composite material plies and between its layers, may be due to thermal effects, vibration, load concentration as a result of stress and strain for provides information’s about structural health monitoring. Virtual energy method such as Hamilton's was used to investigate the effect of the design parameters such as side to thickness and modular as well as material graduation index ratio on the stress-strain relationships, displacement, resultants of stresses, and resultants of mid plane strain. The analysis and simulation of the FGM shells is done in this paper utilizing MATLAB19 code and ABAQUS20 programs. The distribution of characteristics across shell thickness had also been determined using a power law. Normal stress was varied gradually from 5.74 MPa to 9.55 MPa with material index (n) from 0 to 10 respectively, while shear stress varied from 4.2 to 8.23 MPa for the same value of (n). The strain percent increased slightly from 0.00059 to 0.0012 with displacement 0.22 and 1.2 respectively for the same value of (n).
Źródło:
Diagnostyka; 2022, 23, 3; art. no. 2022302
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
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:
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:
Synthesis and activity evaluation of Ce-Mn-Cu mixed oxide catalyst for selective oxidation of co in automobile engine exhaust: effect of Ce/Mn loading content on catalytic activity
Autorzy:
Bilal, Yasir
Nasir, Muhammad Ali
Nasreen, Sadia
Akhter, Niaz Ahmed
Pasha, Riffat Asim
Noor, Muhammad Farhan
Powiązania:
https://bibliotekanauki.pl/articles/101992.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
base metal oxide catalyst
catalytic converter
CO sensor
CO-precipitation
catalytic activity
katalizator tlenku metalu zasadowego
katalizator
czujnik CO
strącanie CO
aktywność katalityczna
Opis:
A series of Mn-doped CeO2-CuO catalyst (CeO2-MnOx-CuO) (Ce/Mn molar ratio of 0.5, 1.0 2.0 and 3.0) were prepared using co-precipitation method for the selective oxidation of CO in automobile engine exhaust. The content of copper was 5.0 wt. % in each sample. Catalysts were installed on the automobile engine exhaust and CO amount was recorded with help of CO sensor, with and without the catalyst. The catalytic converter efficiency was estimated for each catalyst through efficiency formula. It was observed that Ce/Mn catalyst with a molar ratio of 2.0 shows the maximum efficiency (88.35%). Stability of conversion process was analyzed by plotting the CO amount with respect to time. The catalyst with Ce/Mn molar ratio of 2.0 performed the most streamline conversion process with least deviations.
Źródło:
Advances in Science and Technology. Research Journal; 2018, 12, 1; 260-266
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study the Effectiveness of the Natural Lagoons for Removal of Organic Matter, Nutrients and Fecal Coliform from Urban Domestic Wastewater under Arid Climate (Morocco)
Autorzy:
Osmane, Ahmed
Zidan, Khadija
Benaddi, Rabia
Sebah, Imane
Elmouraille, Nadia
Ait Ali, Mustapha
Belmouden, Moustapha
Powiązania:
https://bibliotekanauki.pl/articles/2202383.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
natural lagoon
urban domestic wastewater
organic matter
nutrients
faecal coliforms
Opis:
Morocco is one of the countries most affected by the scarcity of water resources and the poor distribution of rainfall. Natural lagoon is the most widely used treatment process in Morocco. Indeed, Morocco is a sunny country throughout the year. The lagoon system requires minimal effort in operation and maintenance. Moreover, this system is the best process for removing bacteria indicators. For these reasons, a study of the purification performance of natural lagoons during five years, located in Chichaoua region (Morocco) was carried out. The lagoon system was monitored for five years, with measurements taken every three months at the input and output of the system. It received a hydraulic loading rate (HLR) between 1171 and 2760 m3 with an average of 2053 m3/day. The obtained results show the removal of 37% of TSS, 63% of BOD5, 60% of COD, 61% of NH4+, 37% of TP, and 6.5 log units of coliforms during the mentioned monitoring period. Thus, the effluent values do not always comply with the Moroccan water quality requirement for irrigation reuse. Additionally, the statistical analyses confirm the presence of a strong linear correlation between almost all variables in the lagoon output. Therefore, the performance efficiency of the lagoon in removing organic matter and nutrients was significantly (p < 0.05) dependent on the season. However, the fecal contamination was not significantly (p > 0.05) affected by the seasons in this study. At the end of this study a complementary treatment before the reuse of treated wastewater, was proposed.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 196--207
2299-8993
Pojawia się w:
Journal of Ecological Engineering
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:
Social benefits of solar energy: Evidence from Bangladesh
Autorzy:
Salah Uddin, Gazi
Abdullah-Al-Baki, Chowdhury
Park, Donghyun
Ahmed, Ali
Tian, Shu
Powiązania:
https://bibliotekanauki.pl/articles/19905143.pdf
Data publikacji:
2023
Wydawca:
Instytut Badań Gospodarczych
Tematy:
energy transition
solar adaption
clean energy
education
welfare
Bangladesh
Opis:
Research background: The Bangladeshi government has set a plan to generate one-tenth of its electricity from solar and other renewable sources by 2030. Solar adoption surged in Bangladesh up until 2015, setting a global precedent for electrifying areas that were previously unconnected. The enhanced lighting offered by solar systems provides immediate benefits, including additional hours for household and business activities and extended study hours for school-going children. Purpose of the article: This study seeks to identify the determinants and welfare gains of solar adoption in rural areas by analysing three rounds of the Bangladesh Integrated Household Survey from 2011–12, 2015, and 2018–19. In addition to presenting new estimates of economic, environmental, and educational welfare gains, our research offers insights into how solar adoption relates to rural employment and the nutrition of children under five. Methods: We utilized both ordinary least squares and propensity score matching techniques to estimate the welfare effects of solar adoption. Only households that do not use electricity as their primary lighting source, such as those relying on solar or kerosene, are considered in our sample. Findings & value added: We have discovered that adopting solar is linked to higher income, increased expenditure, and growth in asset value. Additionally, there is a significant reduction in kerosene expenditure among adopters compared to non-adopters. Other observations reveal that households with solar setups tend to transition from sharecropping to trading and poultry farming. Children in these households also benefit from solar adoption in terms of education and nutrition. This study illustrates how solar energy can effectively address various welfare concerns in areas where the government cannot supply electricity. Given that recent global events have rendered underdeveloped countries more vulnerable to providing consistent electricity to their entire populations, this research suggests solar energy as a resilient electrification solution during crises.
Źródło:
Oeconomia Copernicana; 2023, 14, 3; 861-897
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shifter mechanism design for FSAE motor sports vehicle JCU
Autorzy:
Wheatley, Greg
Ali, Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/2091242.pdf
Data publikacji:
2021
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
mechanical shifter
solid linkage
spline attachments
FEA
mechaniczna skrzynia biegów
trwałe połączenie
mocowanie wielowypustowe
MES
Opis:
This report provides a design analysis of a replacement’s shifter mechanism for the 2014 model JCU Motorsports FSAE vehicle. Common FSAE shifter mechanisms were researched and reviewed to provide a better understanding of the needs required. A design approach was constructed to ultimately design a mechanism that conformed to all existing constraints and FSAE rules. Realistic load cases were identified and employed in the FEA analysis of the design. Supporting hand calculations were developed, proving the analysis to be accurate. Results showed the shifter mechanism does not fail under infinite life, with some parts of the design having a reasonably high safety factor, ensuring stability.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2021, 113; 219--229
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
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
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:
Plants take action to mitigate salt stress: Ask microbe for help, phytohormones, and genetic approaches
Autorzy:
Hewedy, Omar A.
Mahmoud, Ghada Abd-Elmonse
Elshafey, Naglaa F.
Khamis, Galal
Karkour, Ali M.
Abdel Lateif, Khalid S.
Amin, Basma H.
Chiab, Nour
El-Taher, Ahmed M.
Elsheery, Nabil I.
Powiązania:
https://bibliotekanauki.pl/articles/2174285.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
Bacillus
ion homeostasis
osmoprotectants
osmotic stress
photosynthesis
ROS scavenging
Opis:
Global agriculture is a pivotal activity performed by various communities worldwide to produce essential human food needs. Plant productivity is limited by several factors, such as salinity, water scarcity, and heat stress. Salinity significantly causes short or long-term impacts on the plant photosynthesis mechanisms by reducing the photosynthetic rate of CO2 assimilation and limiting the stomatal conductance. Moreover, disturbing the plant water status imbalance causes plant growth inhibition. Up-regulation of several plant phytohormones occurs in response to increasing soil salt concentration. In addition, there are different physiological and biochemical mechanisms of salt tolerance, including ion transport, uptake, homeostasis, synthesis of antioxidant enzymes, and osmoprotectants. Besides that, microorganisms proved their ability to increase plant tolerance, Bacillus spp. represents the dominant bacteria of the rhizosphere zone, characterised as harmless microbes with extraordinary abilities to synthesise many chemical compounds to support plants in confronting salinity stress. In addition, applying arbuscular mycorrhizal fungi (AMF) is a promising method to decrease salinity-induced plant damage as it could enhance the growth rate relative to water content. In addition, there is a demand to search for new salt-tolerant crops with more yield and adaptation to unfavourable environmental conditions. The negative impact of salinity on plant growth and productivity, photosynthesis, stomatal conductance, and changes in plant phytohormones biosynthesis, including abscisic acid and salicylic acid, jasmonic acid, ethylene, cytokinins, gibberellins, and brassinosteroids was discussed in this review. The mechanisms evolved to adapt and/or survive the plants, including ion homeostasis, antioxidants, and osmoprotectants biosynthesis, and the microbial mitigate salt stress. In addition, there are modern approaches to apply innovative methods to modify plants to tolerate salinity, especially in the essential crops producing probable yield with a notable result for further optimisation and investigations.
Źródło:
Journal of Water and Land Development; 2022, 55; 1--16
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
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:
Nanotechnology in Communication Engineering: Issues, Applications, and Future Possibilities
Autorzy:
Elmustafa, S. Ali Ahmed
Sohal, Harwinder Singh
Powiązania:
https://bibliotekanauki.pl/articles/1182754.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Molecular Nano Technology (MNT)
Molecular communication
Nano machines
Nano-communications
Nanotechnology
Opis:
Nanotechnology nowadays became the most amazing studies developed and an active research areas in many fields including civil, chemical engineering, electronics, and medicine, also in materials. In modern sciences, nanotechnology is considered as the next industrial revolution which it may give more possibilities exceed our expectations in many fields. In telecommunication engineering nanotechnology could provide effective solutions for power efficient computing, sensing, memory enlargement, and human machine interaction. Nanotechnology in communication systems also provides ability for manufacturers to produce computer chips and sensors that are considerably smaller, faster, more energy efficient, and cheaper to manufacture than their present-day modules. In this paper an overview of many issues related to nanotechnology in communication systems are discussed, and also paper will provides a brief ideas of the potential application of various nanotechnology developments in the communication systems and the potential for future possibilities researches that may lead to improved communication systems.
Źródło:
World Scientific News; 2017, 66; 134-148
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mining operations and geotechnical issues in deep hard rock mining – case of Boukhadra iron mine
Autorzy:
Benyoucef, Ali Ahmed
Gadri, Larbi
Hadji, Riheb
Mebrouk, Faouzi
Harkati, Elhaddi
Powiązania:
https://bibliotekanauki.pl/articles/2201672.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie
Tematy:
geomechanic
mining gallery
discontinuity
iron ore
underground mine
geomechanika
kopalnia węgla
kopalnia podziemna
nieciągłość
ruda żelaza
Opis:
Underground mining operations are a very problematic task, especially in poor geotechnical conditions. The right choice of excavation and support techniques leads to adequate and secure mining operations. This should ensure the overall stability of the underground mine with the best productivity and stability performance. In this paper, an empirical model for obtaining support systems for underground galleries was applied. Then, a numerical model for the evaluation of the performance of support measures for rock masses in the Boukhadra iron mine was introduced. Extensive field and laboratory tests were performed to obtain geological, geotechnical, and mechanical data on the entire geologic formations of the (1105 m) level. The performance of the design is supported by the selection of a common support plan between RMR, Q, and UBC systems for each geotechnical unit. Therefore, the rock masses classification based on the geo-mechanical model has determined the suitable support systems. The finite element model (FEM) was used for the analysis of rock mass behaviour, displacements, stress, and plastic point distribution. The results permit the optimization of the plastic zone thickness around the gallery. The outcomes of this study could improve the stability of the mine by choosing the right direction of excavation in consideration to the direction of the discontinuity planes. In order to choose between the current and the recommended mining operations, an equivalent calculation sequence was verified. Our study demonstrated that the consideration of discontinuity sets in the orientation of excavation highly improves the mining conditions with or without support.
Źródło:
Geomatics, Landmanagement and Landscape; 2022, 4; 27--46
2300-1496
Pojawia się w:
Geomatics, Landmanagement and Landscape
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical vapour compression refrigeration system: review part 1: environment challenge
Autorzy:
Mahmood, Raid Ahmed
Ali, Omar M.
Noor, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/1839710.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
czynnik chłodniczy
układ chłodniczy
warstwa ozonowa
alternative refrigerant
mixture refrigerants
vapour compression refrigeration system
ozone depletion potential
global worming potential
R507A refrigerant
natural refrigerant
R-718 (water/steam)
Opis:
In Australia and others developed countries, concerns about global warming have increased, and these concerns influence the use of refrigerants as working fluids in mechanical vapour compression refrigeration systems. One of the most important aspects of refrigerant selection is to reduce its impact on the environment and the ozone layer. This paper provides a comprehensive review of various theoretical and experimental studies which have been carried out on air conditioning and refrigeration applications to investigate the effect of refrigerants on the environment. The analysis in this paper reveals that alternative refrigerants are the most suitable working fluids that can be used in refrigeration systems to meet the needs of the environment. This study also suggests that natural types of refrigerants such as water, carbon dioxide, and hydrocarbon will play a significant role in protecting the environment and providing alternative friendly refrigerants to be used in refrigeration and air conditioning systems.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 4; 130-147
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies