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Wyszukujesz frazę "Ahmed, Ali" wg kryterium: Autor


Tytuł:
Analysis of tropospheric NO2 over Iraq using OMI satellite measurements
Autorzy:
Rajab, Jasim M.
Hassan, Ahmed S.
Kadhum, Jasim H.
Al-Salihi, Ali M.
San Lim, Hwee
Powiązania:
https://bibliotekanauki.pl/articles/118650.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
nitrogen dioxide
air pollution
remote sensing
Baghdad
Iraq
Opis:
Tropospheric nitrogen dioxide (NO2) is a trace gas with important impact on atmospheric chemistry, human health and a key pollutant in particular cities, measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. This study present ten years (monthly and yearly averaged) dataset from Ozone Monitoring Instrument (OMI) used to investigate tropospheric NO2 characteristics and variations over Iraq during 2005–2014. Annual NO2 shows an elevation from the northern to the southern and highest values was at central parts of Iraq. Monthly distributions revels higher values NO2 in winter and summer than spring and autumn seasons, and rising NO2 throughout study period over industrial and crowded urban zones. The trend analysis over Baghdad shows a linear growth rate 9.8% per year with an annual average (5.6·1015 molecules per 1 cm2). The air mass trajectory analysis as hotspot regions shows seasonal fluctuations between winter and summer seasons depend on weather conditions and topography. The increased NO2 values in winter are due to anthropogenic emissions and subsequent plumes from Europe. In addition, in summer because of hot weather and large paddy fields emissions. The lowest NO2 value was at monsoon period mostly linked to the rains. The OMI data and satellite information are able to observe the troposphere NO2 elevation at different regions.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2020, 29, 1; 3-16
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Apolocystis proventus sp. nov. (Apicomplexa: Monocystinae) a New Species of Aseptate Gregarine from Egyptian Earthworms: Pheretima californica and Pheretima elongata (Annelida: Oligochaeta)
Autorzy:
RAMADAN, Nadia
FAWZ, Samia
ALI, Medhat
NIGM, Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/763776.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Gregarine, Pheretima, Coelom, Apolocystis, Pharyngeal glands, Apicomplexa and Monocystinae
Opis:
A new acephaline gregarine is described from the earthworms Pheretima californica and Pheretima elongata. The gregarine was either embedded in the pharyngeal glandular tissue or found free in the coelomic fluid around the pharyngeal region in front of the crop. Adult trophozoites measured 48–65 µm in diameter and are mostly active with a wavy pellicle. Heterogeneity in the endoplasm of active trophozoites was observed. Gametocysts measured 56–81 µm in diameter, with a characteristic thick cyst wall. Navicular sporocysts measured 5.8 ± 0.2 × 3.5 ± 0.4 µm, with small truncate plugs.
Źródło:
Acta Protozoologica; 2015, 54, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Artificial Neural Network for Estimation of Local Scour Depth Around Bridge Piers
Autorzy:
Shakir Ali Ali, Ahmed
Günal, Mustafa
Powiązania:
https://bibliotekanauki.pl/articles/2097766.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
artificial neural network
bridge pier
hydraulics
local scour
Opis:
Local scour around bridge piers impairs the stability of bridges’ structures. Therefore, a delicate estimation of the local scour depth is vital in designing the bridge piers foundations. In this research, MATLAB software was used to train artificial neural network (ANN) models with four hundred laboratory datasets from different laboratory studies, including five parameters: pier diameter, flow depth flow velocity, critical sediment velocity, sediment particle size, and equilibrium local scour depth. The outcomes present that the ANN model with the Levenberg-Marquardt algorithm and 11 nodes in the single hidden layer gives an accurate estimation better than other ANN models trained with different training algorithms based on the regression results and mean squared error values. Besides, the ANN model accurately provides predicted local scour depth and is better than linear and nonlinear regression models. Furthermore, sensitivity analysis shows that removing pier diameter from training parameters diminishes the reliability of prediction.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2021, 68, 2; 87--101
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing the organizational commitment, subjective vitality and burnout effects on turnover intention in private universities
Autorzy:
Parmar, Vishnu
Channar, Zahid Ali
Ahmed, Rizwan Raheem
Streimikiene, Dalia
Pahi, Munwar Hussain
Streimikis, Justas
Powiązania:
https://bibliotekanauki.pl/articles/19322490.pdf
Data publikacji:
2022
Wydawca:
Instytut Badań Gospodarczych
Tematy:
turnover intention
job burnout
emotional exhaustion
organizational cynicism
professional efficacy
subjective vitality
affective commitment
normative commitment
continuance commitment
Opis:
Research background: Faculties of private universities are under immense working pressure, which causes stress and burnout. The job burnout triggers the psychological pressure, which increases the turnover intention.  Purpose of the article: The undertaken study aims to evaluate the scale of burnout with its three-element model, which affects faculty members of private universities of Pakistan. This research also aims to examine the mediating effect of organizational commitment (e.g., affective, normative & continuance commitments), and moderating influence of subjective vitality in a relationship of job burnout and its constituents, for example exhaustion, efficacy & cynicism, and the turnover intention. Methods: The 712 responses were collected through a structured questionnaire from the junior and senior faculty members of private universities of Pakistan. The data was examined by using second order partial least square - structural equation approach - PLS-SEM. Findings & value added: The research findings exhibited that emotional exhaustion, cynicism, and professional efficacy have a direct significant influence on job burnout. The findings further demonstrated that the job burnout has a cogent and negative impact on faculty turnover intention. The findings demonstrated that elements of organizational commitment (e.g., normative, affective & continuance commitments) have a forceful serial mediating influence between burnout & its constituents for example exhaustion, efficacy & cynicism, and turnover intention. Finally, the findings have revealed that subjective vitality has a significant and positive impact as a moderating variable in a relationship between job burnout and turnover intention. This research has a long-term theoretical contribution, as it provides a novel conceptual framework, which can be replicated in different industries. Thus, this unique model provides the solution to reduce employees' turnover for other industries as well. 
Źródło:
Oeconomia Copernicana; 2022, 13, 1; 251-286
2083-1277
Pojawia się w:
Oeconomia Copernicana
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:
Assessment of Modified Rice Husks for Removal of Aniline in Batch Adsorption Process: Optimization and Isotherm Study
Autorzy:
Dakhil, Ihsan Habib
Naser, Ghazi Faisal
Ali, Ahmed Hassan
Powiązania:
https://bibliotekanauki.pl/articles/1955426.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
adsorption
aniline
modified rice husk
optimization
Opis:
The present work is aimed at investigating the capability of chemically modified rice husks (MRH) for the reduction of aniline ions from industrial wastewater. The experiments have been conducted to examine the influence of four operating parameters in the batch adsorption technique. The effect of initial concentrations of aniline (10–100) mg•L-1, MRH dose (0.1–1) g/100 ml, pH (3–9), and contact time (10–90) min has been studied. The selected range of operating factors was designed using the response surface method to establish a mathematical model that describes the adsorption process. The optimum parameters were 25 mg•L-1 initial concentration of aniline, 0.68 g MRH dose, 6.6 pH, and 70 min contact time. The point of zero charge was found equal to 6.8. The maximum removal efficiency of 84.97% was found under optimum conditions. The consistency of the mathematical model has been examined and the equilibrium results confirmed with the standard adsorption isotherm models, Langmuir and Freundlich, with a high correlation coefficient.
Źródło:
Journal of Ecological Engineering; 2021, 22, 7; 179-189
2299-8993
Pojawia się w:
Journal of Ecological Engineering
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:
Bee Pollen as a Functional Product – Chemical Constituents and Nutritional Properties
Autorzy:
Alshallash, Khalid S.
Abolaban, Gomaa
Elhamamsy, Sam M.
Zaghlool, Ayman
Nasr, Ali
Nagib, Ashraf
Abd El-Hakim, Ahmed F.
Zahra, Abdullah A.
Hamdy, Ashraf E.
Taha, Ibrahim M.
Powiązania:
https://bibliotekanauki.pl/articles/2202357.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
eucalyptus
clover
maize
phenolic content
amino acid
pollen
Opis:
Nutritional supplements play a role in promoting human protein synthesis, fitness recovery, and mental health protection. Pollen is considered a natural food with excellent nutritional value. The use of bee-gathered pollen as a nutritional supplement is now widespread around the world, and it is appreciated for its healing qualities. However, depending on the floral species and the region of origin, pollen has a wide range of nutritional value. It was found that clover pollen had the highest protein content (31.4 g/100 g DM), while the lowest content was observed in maize pollen (21.3%). Eucalyptus pollen had the highest lipid amount (9.49 g/100 g DM), while clover pollen had the lowest content (7.46 g/100 g). Phytochemical analysis showed that eucalyptus pollen occupied the highest total antioxidant activity (67.02%), followed by clover (58.25%) then maize (52.18%), whereas clover pollen had the highest phenolic content (1165 mg GAE/100 gm), compared with the other pollen varieties (949.4 to 1073 mg-GAE/100 gm). The contents of branched-chain amino acids were 29, 33.3, and 38.4 mg/g for maize, eucalyptus, and clover respectively, representing 17.87, 18.44, and 16.53% of total amino acids. The contents of total essential amino acids (EAAs) were 61.8, 73.0, and 83.5 mg/g for maize, eucalyptus, and clover pollen, respectively. Only eucalyptus pollen ultimately met the minimum requirements of EAAs for adults. In contrast, the other two types of pollen contained at least 3–4 limiting amounts of the essential amino acids leucine, lysine, phenylalanine, and valine. In conclusion, pollen is a good, affordable source of nutrients that can be utilized as beneficial dietary supplements for human health.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 173--183
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical Composition, Cytotoxic and Antioxidant Activities of Celosia trigyna L. Grown in Saudi Arabia
Autorzy:
El-Desouky, Samy
Abdelgawad, Ahmed
El-Hagrassi, Ali
Hawas, Usama
Kim, Young-Kyoon
Powiązania:
https://bibliotekanauki.pl/articles/895232.pdf
Data publikacji:
2019-08-30
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
GC-MS
antioxidant activity
cytotoxic activity
Celosia trigyna
flavonoid-glycosides
Opis:
The methanol extract of the aerial parts of Celosia trigyna (Amaranthaceae) was successively fractionated using n-hexane, dichloromethane, ethyl acetate and n-butanol. The cytotoxic activity of the obtained fractions was investigated using sulphorhodamine-B (SRB) assay against three carcinoma cell lines; breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT-116) and hepatocellular carcinoma cells (HepG2). The dichloromethane fraction showed significant in vitro cytotoxic activities against the human cancer cell lines HCT-116 and HEP-G2 with IC50 values of 10.9 and 11.2 µg/mL, respectively, while all fractions revealed weak antioxidant activity using DPPH free radical scavenging method. The GC-MS analysis of the most cytotoxic dichloromethane fraction has resulted in the identification of 12 compounds. The main constituents were tetrahydroisoquinoline derivative (31.44%), 2,3-dimethylheptadecane (16.71%) and 3-octadecanone (15.56%). Moreover, the phytochemical study of the dichloromethane and n-butanol fractions led to the isolation and identification of five known compounds identified as β-amyrin acetate (1), acacetin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (2), apigenin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (3), quercetin 3-O-α-rhamnosyl-(1→6)-β-glucopyranoside (4) and 3-hydroxyglutaric acid (5).
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 4; 691-699
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climate change necessitates a change in the cultivation date of caraway (Carum carvi L.)
Autorzy:
Ibrahim, Mostafa Fathi
Ali, Muhammad Moaaz
Lamlom, Sobhi F.
Kalaji, Hazem M.
Yousef, Ahmed F.
Powiązania:
https://bibliotekanauki.pl/articles/2174359.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
climate change
condiment
leafy vegetable
sowing time
vegetative growth
volatile oil
Opis:
By 2050, global crop demand is projected to rise by 60-110%. Crop yields have also been impacted by cli mate change in some nations, and these impacts are likely to continue. To prevent the influence of climate change on crop output, it is critical to adjust planting times in weather-related open fields to meet food security concerns. Present study was carried out at Experimental Farm of Faculty of Agriculture, Al-Azhar University, Assiut, Egypt, during two successive seasons, 2019 and 2020. It was aimed to study the effect of different sowing times (1st and 15th October, 1st and 15th November), and plant spacings (25, 20, and 15 cm) on growth, fruit yield, and oil production of caraway (Carum carvi L.) plants. The results showed that sowing caraway plants on 15th October with plant spacing of 25 cm gave the highest dry weight (72.6 g∙plant-1), fresh weight (266.15 g∙plant-1), seed yield (37.43 g∙plant-1), and oil yield (0.659 cm 3∙plant-1). The maximum umbels (50.83 number per plant) and essential oil (1.78%) were also recorded in the plants receiving same treatment. On the other hand, plants sown at 15th November with spacing of 15 cm exhibited the minimum values of recorded traits. While the highest value of plant height gave with sowing caraway plants on 15th October with plant spacing of 15 cm (135.35 cm). In conclusion, the plants sowed on October 15th with a maximum plant spacing of 25 cm had the highest values of the evaluated morphological, biochemical, and yield attributes of caraway.
Źródło:
Journal of Water and Land Development; 2022, 54; 38--47
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
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:
Datasets and future research suggestions concerning SARS-CoV-2
Autorzy:
Szmuda, Tomasz
Ali, Shan
Özdemir, Cathrine
Syed, Mohammad Talha
Singh, Akshita
Hetzger, Tarjei Vevang
Rosvall, Philip
Fedorow, Karolina
Alkhater, Ahmed
Majlöf, Anders
Albrahim, Mohammed
Alquraya, Eyad
Dunquwah, Rakan Al
Al-hakeem, Zahraa
Almohisin, Emad
Alradhi, Mohammed
Żydowicz, Weronika Magdalena
Müller, Charlene
Egeland, Ada
Bergersen Kinstad, Aurora
Ngyuen, Jessica
Bergersen Kinstad, Martin
Al-Rubaye, Ibraheem
Al-Khazragi, Yasmin
von Dardel, Beatrice
Dave, Bhakti
Słoniewski, Paweł
Fercho, Justyna
Kierońska, Sara
Powiązania:
https://bibliotekanauki.pl/articles/1198432.pdf
Data publikacji:
2020-05-26
Wydawca:
Gdański Uniwersytet Medyczny
Tematy:
BCG
COVID-1
SARS-CoV-2
datasets
data
epidemiology
Google trends
Opis:
We gathered publicly available online data and prepared a database of epidemiology, demographics, economics, Bacille Calmette-Guérin vaccination and online search trend statistics relevant to the coronavirus disease 2019 (COVID-19). Moreover, we provide several suggestions on the use of this bioresource and reference other relevant datasets to promote research on COVID-19.
Źródło:
European Journal of Translational and Clinical Medicine; 2020, 3, 2; 80-85
2657-3148
2657-3156
Pojawia się w:
European Journal of Translational and Clinical Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design optimization for the weight reduction of 2-cylinder reciprocating compressor crankshaft
Autorzy:
Arshad, Ali
Cong, Pengbo
Elsayed Elmenshawy, Adham Ahmed Awad
Blumbergs, Ilmārs
Powiązania:
https://bibliotekanauki.pl/articles/1845022.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reciprocating compressor
crankshaft optimization
weight reduction
topology optimization
stress
distribution
crank web
lightweight crankshaft design
crack modeling
static structural analysis
modal analysis
sprężarka tłokowa
optymalizacja wału korbowego
redukcja wagi
optymalizacja topologii
naprężenie
dystrybucja
wstęga korby
lekka konstrukcja wału korbowego
modelowanie pęknięć
statyczna analiza konstrukcji
analiza modalna
Opis:
This study aims to optimize the 2-cylinder in-line reciprocating compressor crankshaft. As the crankshaft is considered the "bulkiest" component of the reciprocating compressor, its weight reduction is the focus of current research for improved performance and lower cost. Therefore, achieving a lightweight crankshaft without compromising the mechanical properties is the core objective of this study. Computational analysis for the crankshaft design optimization was performed in the following steps: kinematic analysis, static analysis, fatigue analysis, topology analysis, and dynamic modal analysis. Material retention by employing topology optimization resulted in a significant amount of weight reduction. A weight reduction of approximately 13% of the original crankshaft was achieved. At the same time, design optimization results demonstrate improvement in the mechanical properties due to better stress concentration and distribution on the crankshaft. In addition, material retention would also contribute to the material cost reduction of the crankshaft. The exact 3D model of the optimized crankshaft with complete design features is the main outcome of this research. The optimization and stress analysis methodology developed in this study can be used in broader fields such as reciprocating compressors/engines, structures, piping, and aerospace industries.
Źródło:
Archive of Mechanical Engineering; 2021, LXVIII, 4; 449-471
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Designing an upper stage steering system for a formula FSAE car
Autorzy:
Wheatley, Greg
Ali, Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/2091236.pdf
Data publikacji:
2021
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
design
steering
race car
projekt
układ kierowniczy
samochód wyścigowy
Opis:
The objective of this work is to design an upper stage steering system for the Formula FSAE car “Omega” that will effectively translate driver input force to the rack and pinion. The system consists of a steering wheel, steering shafts, universal joints, a quick release mechanism, and connection points to the car. Critical loads have been determined, and the final design has been validated using finite element analysis to ensure the safety of the assembly during normal operation and worst-scenario cases. The design key factors were performance, weight, cost, ergonomics, maintainability, manufacturability and reliability.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2021, 113; 205--218
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Desulfurization of Crude Oil by Laboratory Developed Multipumping Flow Injection Analysis System with Optimization by Response Surface Methodology
Autorzy:
Hadi, Ahmed Abdulrazzaq
Ali, Ali Abdulkhabeer
Khathi, Mohammed Turki
Powiązania:
https://bibliotekanauki.pl/articles/2202370.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
multi-pumping flow system
desulfurisation
response surface
optimal conditions
Opis:
Sour crude oil is the crude oil that contains a high level of sulfur impurity. It can be toxic and corrosive. Before this lower-quality crude can be processed into other crude oil derivatives, the sulfur content must be reduced, raising the processing cost. A homemade semi-automated multipumping flow analysis system was constructed, consisting of several parts available on the local markets and at low economic costs to decrease the sulfur content of crude oil samples collected. The central composite design (CCD) and response surface methodology (RSM) have been used for modeling and optimization. The effects of the operational parameters, including polar and nonpolar solvent types, solvent flow rates (10–40 ml/min), mixing coil lengths (120–200 min), temperature (30–60 °C), and solvent entry time to the system (0–60 sec) were studied. Experimental and theoretical applications were made to determine the optimal sulfur content, which came out to be 1.438 and 1.395 wt.%, respectively. This system evaluated the effectiveness of the sulfur removal content for actual heavy crude oil by experimentally and theoretically to be 65.73 and 66.75% respectively. The semi-automated system was applied successfully to reduce the sulfur content in a highly sensitive and accurate way.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 328--339
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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