The Wadi El-Rayan is a depression in the Fayoum oasis collecting agricultural drainage water from the Fayoum. Since 1973, this drainage water formed two man-made lakes. Twenty years ago, a third ...lake, called Lake Magic was formed. Since this newly formed lake was not yet studied, in January of 2019 we conducted research related to its physico-chemical (ion composition, nutrients, heavy metals, etc.) and biological (phyto-, bacterio- and zooplankton) characteristics. The depth of the lake ranged from 1.5 to 9.0 m, water transparency was up to 4.0 m, and the water temperature was 13.6 °C. The average salinity was 29.1 g/l, and the salinity of drainage waters from agricultural fields was 2.9 g/l. A total of 28 phytoplankton species was identified belonging to Bacillariophyceae (eight species), Dinophyceae (three species), Cyanobacteria (seven species), Chlorophyceae (nine species) and Conjugatophyceae (one species). Chlorophyll
a
content varied from 14.3 to 24.2 μg/l. In zooplankton, there were three species of Ciliophora, five of Rotifera, and two Copepoda as well as Nematoda and Cirripedia larvae. Salinity in Lake Magic was much higher than in drainage waters coming in the lake. This is a result of a strong salinity increase in Lake Magic after its creation due to climate aridity, and salinity may markedly increase during the next 20 years along with the sharp changes of the lake's ecosystem.
Le Wadi El-Rayan est une dépression dans l'oasis du Fayoum qui recueille les eaux de drainage agricole du Fayoum. Depuis 1973, ces eaux de drainage ont formé deux lacs artificiels. Il y a vingt ans, un troisième lac, appelé Lac magique, s'est formé. Comme ce lac nouvellement formé n'était pas encore étudié, nous avons mené en janvier 2019 des recherches sur ses caractéristiques physico-chimiques (composition ionique, nutriments, métaux lourds, etc.) et biologiques (phyto-, bactério- et zooplancton). La profondeur du lac variait de 1,5 à 9,0 m, la transparence de l'eau atteignait 4,0 m et la température de l'eau était de 13,6 ᵒC. La salinité moyenne était de 29,1 g/l, et la salinité des eaux de drainage des champs agricoles était de 2,9 g/l. Au total, 28 espèces de phytoplancton ont été identifiées, appartenant aux catégories suivantes : Bacillariophyceae (huit espèces), Dinophyceae (trois espèces), Cyanobactéries (sept espèces), Chlorophyceae (neuf espèces) et Conjugatophyceae (une espèce). La teneur en chlorophylle a varié de 14,3 à 24,2 μg/l. Dans le zooplancton, il y avait trois espèces de Ciliophora, cinq de Rotifera, et deux Copepoda ainsi que des larves de Nematoda et de Cirripedia. La salinité du lac magique était beaucoup plus élevée que celle des eaux de drainage provenant du lac. Ceci est le résultat d'une forte augmentation de la salinité du lac magique après sa création en raison de l'aridité du climat, et la salinité pourrait augmenter sensiblement au cours des 20 prochaines années en même temps que les changements importants de l'écosystème du lac.
This study focuses on changes in zooplankton composition and abundance in Lake Nasser during different flood periods before the construction of the Grand Ethiopian Renaissance Dam (GERD). Field ...surveys were carried out in August 2016 (flood period), December 2016 (post-flood period), and May 2017 (pre-flood period). Fifteen sampling sites representing five sectors were selected to cover the lake whole area. The results revealed a highly significant difference (p ≤ 0.016) in the density of all identified zooplankton groups among different flood seasons and lake locations. The zooplankton standing crop during the flood was higher, by a factor of approximately 3.7, than that recorded in post-flood and pre-flood periods. Zooplankton was dominated by medium-sized Copepoda, two cyclopoids (Thermocyclops neglectus and Mesocyclops ogunnus) and one calanoid (Thermodiaptomus galebi). The euplanktonic rotifer Keratella cochlearis dominated, during post-flood and pre-flood periods, constituting approximately 83% and 77% of total rotifer densities, respectively. Keratella tropica occurred in greatest density during flood made up 52.6% of total rotifers. Diaphanosoma mongolianum was the main cladoceran during flood and post-flood periods, whereas Ceriodaphnia dubia densities were highest for pre-flood periods. This study found that flood regime affect zooplankton composition and density in Lake Nasser.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
This article analyzes parallel flow microchannel heat exchangers with non-adiabatic thermal condition imposed on the wall separating the fluids and the ambient. For purposes of analysis, a thermal ...model comprising of two governing equations, one for each of the fluids, is developed and analytically solved to obtain equations for calculating the axial temperature and thereby the effectiveness of both fluids. Provision is provided in these equations for the temperature of the ambient interacting with the hot fluid to be different from that associated with the cold fluid. Analytical equations for determining the heat transfer between the individual fluids and the respective ambient as well as that between the fluids are also developed in this paper. The temperatures/effectiveness of the fluids depend on parameters such as NTU, fluid heat capacities, thermal resistance between the individual fluid and the respective ambient and ambient temperatures. In addition, under certain operating conditions the phenomenon of temperature-cross is observed. Depending on the ambient temperatures, increase in NTU will continuously improve the effectiveness of one the fluids; the effectiveness of the other fluid over the same NTU range increases before peaking and subsequent decrease. Equations for determining the NTU at which this peak value in effectiveness occurs are also provided. An unbalanced flow microchannel heat exchanger with the hot fluid having the lowest heat capacity has better effectiveness than when the cold fluid has the lowest heat capacity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Zirconia and mixed zirconia/titania were synthesized in two different ionic liquids, namely, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) amide (BMPTFSA) and 1-ethyl-3-methylimidazolium ...bis(trifluoromethylsulfonyl) amide (EMImTFSA) using sol–gel methods. The synthesized oxides were characterized by means of X-ray diffraction, scanning electron microscopy with energy dispersive X-ray (SEM-EDX)), thermogravimetric and differential thermal analyses (TGA–DTA). The results show that the as-synthesized ZrO
2
powders obtained either in BMPTFSA or in EMImTFSA show amorphous behaviour, and calcination at 500 °C yields t-ZrO
2
which is subject to further phase transformation to m-ZrO
2
at 1000 °C. The type of the ionic liquid influences the morphology of the synthesized zirconia as the sample obtained from BMPTFSA showed a porous morphology with very fine particles in the nanometer regime, whereas micro-rods were obtained from EMImTFSA. ZrO
2
-TiO
2
nanorods with an average diameter of about 100 nm were synthesized in EMImTFSA. The presence of zirconia in the mixed oxides stabilizes the anatase phase and elevates the temperature at which the phase transformation to rutile occurs.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Wadi El Natrun is an elongated narrow depression in the Western Desert of Egypt. The depression characterized by many ancient alkaline salt lakes. These lakes are filled with water in winter and ...dried up in summer. Recently, some lakes become permanently dried, while others become submerged throughout the year as El Bieda Lake. El Bieda Lake has undergone ecological changes due to the prolonged extraction of minerals and the continual discharging of freshwater. This study investigates the recent biotic and abiotic changes of this lake and discusses its fisheries opportunities. The lake’s water is well-oxygenated, rich with different inorganic nutrients, and characterized by a low salinity. Sodium and chloride ion concentrations are lower than the equivalent surface seawater, while magnesium, calcium, potassium, sulfate, and bicarbonate ions are higher. The lake has low plankton species richness with high biomass and high nutritional values. More recently, two cichlid species,
Oreochromis aureus
and
Coptodon zillii
, have colonized the lake. Summer characterized by a very low mortality for
Oreochromis aureus
and a poor representation of
Coptodon zillii
. However, both species shared the catch the rest of the year. The high biomass and nutritional quality of plankton communities, as well as the dense phytobenthic film, indicate that the lake is currently below its carrying capacity. The well-oxygenated water, high biomass of plankton and phytobenthic diatoms, and the expected changes in salinity suggest that introducing the euryhaline, commercially valuable, and fast-growing
Mugil cephalus
or
Chelon ramada
in El Bieda Lake is highly advisable.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This trial was conducted to study the ability of dietary propylene glycol to mitigate winter stress of Nile tilapia under biofloc system. Nile tilapia (average initial weight = 28.50 ± 0.25 g) were ...fed three isonitrogenous (257.75 g kg−1 crude protein) diets for 47 days in winter season. The first diet was free added with propylene glycol (PG) control. The other two diets were supplemented with 5 mL and 7.5 mL PG kg−1 diet, respectively. At the end of feeding trial, the highest survival rate (P < 0.05) was observed in tilapia fed the diet supplemented with 7.5 ml PG kg−1 diet. A linear response in weight gain (WG; P = 0.034), specific growth rate (SGR; P = 0.041) and protein efficiency ratio (PER; P = 0.038) of tilapia were found by the increase in the PG levels in diets. The supplemental diets with PG did not induce any significant differences (P > 0.05) on feed conversion ratio (FCR) and feed intake (FI) of fish. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cholesterol, triglyceride and low density of lipoprotein cholesterol (LDL-C) were linearly decreased in response to the increased the PG level. Also, linear increase in serum total protein, albumin, globulin and lipoprotein cholesterol (HDLC) were found in response to supplementation of PG. Significant linear increased in the concentration of serum ions; sodium, calcium and chloride were observed with increasing the PG level. Significant linear increased were found in superoxide dismutase (SOD; P = 0.035), catalase (CAT; P = 0.001), glutathione (GSH; P = 0.056) and glutathione peroxidase (GPx; P = 0.048) for fish fed 5- or 7.5-ml PG kg−1 under cold stress, with the highest values in fish fed 7.5 ml PG kg−1. While, the activity of malondialdehyde (MDA; P = 0.023) was linearly reduced with increasing of the PG levels in fish diets, with the lowest value in group fed supplemental diet with 7.5 ml kg−1 PG. The response of glucose (P = 0.026) and cortisol (P = 0.193) of fish in cold stress for 47 days were linearly with increasing PG supplementation. The transcription of Δ 9D gene of fish reared under cold stress was linearly up regulated (linear, P = 0.001) with increasing dietary PG level. In conclusion, diet supplemented with 7.5 ml kg−1 PG could decrease the mortality, and enhance the physiological status as well as transcription of Δ 9D gene of fish reared under cold stress.
•Inclusion of propylene glycol increased the survival of tilapia exposed to cold stress.•Propylene glycol showed enhancement on growth performance and feed utilization of tilapia under cold stress.•Propylene glycol showed enhancement on immune response and delta-9-desaturase gene expression of tilapia under cold stress.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the current study, analysis, modeling, and optimization of machining with nano-additives based minimum quantity lubrication (MQL) during turning Inconel 718 are presented and discussed. ...Multi-walled carbon nanotubes (MWCNTs) and aluminum oxide (Al2O3) gamma nanoparticles were utilized as used nano-additives. The studied design variables include cutting speed, feed rate, and nano-additives percentage (wt. %). Three machining outputs were considered namely: flank wear, surface roughness, and energy consumption. The novelty here focuses on improving the MQL heat capacity by employing two different nano-fluids. The analysis of variance (ANOVA) technique was employed to investigate the influence of the design variables on the studied machining outputs. The results demonstrated that the usage of MQL-nanofluids improved the cutting process performance compared to the classical approach of MQL. It was found that 4 wt. % of added MWCNTs decreased the flank wear by 45.6% compared to the pure MQL. Similarly, it was found that 4 wt. % of added Al2O3 nanoparticles improved the tool wear by 37.2%. Besides, the nanotubes additives showed more improvements than Al2O3 nanoparticles in terms of tool wear, surface quality, and energy consumption. Regarding the modeling stage, artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and genetic programming (GP) are employed to model the measured outputs in terms of the studied parameters. These soft computing approaches provide various advantages through their self-learning capabilities, fuzzy principles, and evolutionary computational concept. In addition, a comparison among the developed models has been conducted to select the most accurate approach to present the machining characteristics. Finally, the non-dominated sorting genetic algorithm (NSGA-II) was utilized to optimize the studied cutting processes. Moreover, a comparison between the optimized results from different approaches is presented. The proposed methodology presented in this work can be further implemented in other machining cases to model, analyze as well as optimize the machining performance, especially for the hard-to-cut materials which are commonly used in different industries.
•Analysis and modeling of turning Inconel 718 with MQL-nano-fluids are proposed.•ANN, ANFIS, and GP were employed to model the studied outputs.•NSGA-II was utilized to optimize the studied cutting processes.•A clear mechanism of using MQL-nanofluid was offered.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
An uneasy population increase requires expansion of the agricultural area. Egypt has a strategic direction in expanding agricultural areas, which highlights the objective of the research that is to ...assess soil fertility through its geographical assessment and remote sensing. The examination region of this investigation is situated in north region of west desert, about 55 km, west of Cairo, Egypt. A semi-detail survey was carried out using remote sensing (RS) and geographic information systems (GIS) for the study. The results found the high suitable areas (S
1
) for field crops; barley and wheat were about 54.7% for each of the total area, while for corn and beans were about 44.9% for each of the total area, while S
1
areas for vegetable crops; tomato, eggplant, and melon were 67.8, 71.2, and 53.2% of the total area, respectively, while S
2
for pepper–zucchini was about 65.4 and 49.7% of the total area, respectively. But for fruit trees, S
1
is for pears (60.3%), pomegranates (50.9%), and palms (80.2%) while S
2
for olives (30.3%), Figs. (30.3%), almonds (10.4%), vines (19.7%), and peaches (20.5%). To reduce water losses is by improving the means of delivery and raising the efficiency of irrigation, by evaluating the appropriate situation of the irrigation system for soil quality in the study area, and by choosing the appropriate methods of irrigation in the region to raise efficiency in rationalizing consumption and reducing losses. Drip and sprinkle irrigation suitability for the entire area are moderate to high, where soil texture factor is limiting drip irrigation method while wind speed and soil texture factors are limiting sprinkle irrigation in the area.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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