Cultivation of the green seaweed Enteromorpha compressa was performed under natural laboratory spring environmental conditions of temperature, light intensity and photoperiod to study the salinity tolerance of this intertidal green macroalga. Cultivation was carried out under artificial seawater (ASW) of different concentrations (18, 35, 53 and 106 g/l sea salt) compared to the control using natural seawater (NSW). Growth rate and pigment content of the cultivated alga were recorded at regular intervals during the experimental duration. Antioxidant activity of the crude ethanolic extract and its fractions (petroleum ether, chloroform, ethyl acetate and acetone) was performed against DPPH radical scavenging assay and compared to the standard synthetic antioxidant butylated hydroxy-toluene (BHT). The finding showed that enhancement of algal growth rate under ASW concentrations of 35, 53 and to a lesser extent at 106 g/L during the first 15 days of cultivation were due to the increased pigment biosynthesis, photosynthetic and metabolic activities and followed by gradual retardation due to the impact of prolonged salt stress. Antioxidant activity of alga was found to be concentration, type of extract and incubation time dependent. Acetone fraction of all salt concentrations showed higher antioxidant activity compared to other fractions. Pronounced activity was recorded at higher seawater conc. (106g/l).
تعد عملية اتخاذ القرارات الستراتجية للموازنة الراسمالية احدى المعضلات التي تواجه منظمات الاعمال عند القيام بتخصيص ، او اعادة تخصيص مواردها الاقتصادية النادرة على أفضل استخدام ، والسبب يعود الى ان هذا النوع من القرارات ينطوي على صعوبات متعددة ومختلفة نظراً لندرة الموارد من ناحية الاستخدامات البديلة المتنافسة على هذه الموارد من ناحية اخرى .
كما ان تنفيذ المشروعات الراسمالية يحتاج الى تمويل ضخم ومدة زم
... Show Moreتتسارع التحولات السياسية في العصر الحديث، وتتزايد التحديات التي تواجه المجتمعات، حيث يظهر التطرف كظاهرة تهدد أمن الدول واستقرارها، وتعد الإصلاحات السياسية خطوة حيوية نحو تحقيق تنمية مستدامة وتحقيق التوازن في المجتمعات. أذ يهدف هذا البحث إلى استكشاف وتحليل دور الأصلاح السياسي كآلية فعالة في مكافحة ظاهرة التطرف. وطالما أن الدول في المنطقة العربية تعاني من التسلط والأستبداد وغياب دور المؤسسات السياسية الفعل
... Show Moreدور الحكومات في بناء الدولة ضمن اطار الدستور
دور وزارة الخارجية الامريكية في عملية صنع القرار
Summary:
This research revolves around the probing of those whom Ibn Hajar said, "He has a vision", its significance, and the ruling on the connection and transmission to it. The number of narrators reached fifty-one (51) narrators, among whom it was said, “He has a vision, whether it is definite or possibly. Some of them had a vision and companionship.”They are eleven (11) narrators, And among them were those who had visions and had no company, and their number was twenty-one (21) narrators, and among them were those who had no vision and nor company, and their number is nineteen (19) narrators.
As a result , whoever said about him “has a vision” and has companions, his hadith is connected, even i
The adsorption of hexavalent chromium by preparing activated carbon from date seeds with zinc chloride as chemical activator and granular date seeds was studied in a batch system. The characteristics of date seeds and prepared activated carbon (ZAC) were determined and found to have a surface area 500.01 m2/g and 1050.01 m2/g , respectively and iodine number of 485.78 mg/g and 1012.91 mg/g, respectively. The effects of PH value (2-12), initial sorbate concentration(50-450mg/L), adsorbent weight (0.004-0.036g) and contact time (30-150 min) on the adsorption process were studied . For Cr(VI) adsorption on ZAC, at 120 min time contact, pH solution 2 and 0.02 adsorbent weight will ach
... Show MoreIn this work, the impact of different geomagnetic storm events on the plasma-sphere layer (ionosphere layer) over the northern and southern hemisphere regions was investigated during solar cycle 23. To grasp the influence of geomagnetic storms on the behavior and variation of the critical frequency parameter of the F2 ionospheric layer (foF2), five geomagnetic storms (classified as great, severe, and strong), with Disturbance storm time (Dst) values <-100 nT were chosen. Four stations located in different mid-latitude regions in northern and southern hemispheres were designated, the northern stations are: Millstone Hill (42.6° N, 288.50° W) and Rome (41.90° N, 12.50° E) and the southern stations are: Port Stanley (-51.60° S,
... Show MoreThis study focusses on the effect of using ICA transform on the classification accuracy of satellite images using the maximum likelihood classifier. The study area represents an agricultural area north of the capital Baghdad - Iraq, as it was captured by the Landsat 8 satellite on 12 January 2021, where the bands of the OLI sensor were used. A field visit was made to a variety of classes that represent the landcover of the study area and the geographical location of these classes was recorded. Gaussian, Kurtosis, and LogCosh kernels were used to perform the ICA transform of the OLI Landsat 8 image. Different training sets were made for each of the ICA and Landsat 8 images separately that used in the classification phase, and used to calcula
... Show MoreAbstract
This paper concerned with study the effect of a graphite micro powder mixed in the kerosene dielectric fluid during powder mixing electric discharge machining (PMEDM) of high carbon high chromium AISI D2 steel. The type of electrode (copper and graphite), the pulse current and the pulse-on time and mixing powder in kerosene dielectric fluid are taken as the process main input parameters. The material removal rate MRR, the tool wear ratio TWR and the work piece surface roughness (SR) are taken as output parameters to measure the process performance. The experiments are planned using response surface methodology (RSM) design procedure. Empirical models are developed for MRR, TWR and SR, using the analysis
... Show More