ABSTRACT The antibacterial and antbiofilm activities of water extract of Calendula officinalis flowers against some of enteropathogenic bacteria was studied, also phytochemical screening and determination of antioxidant activity of the extract has been investigated. The results showed that the water extract of C. officinalis exhibited a good antibacterial activity against all pathogenic bacterial isolates (Salmonella, Shigella dysenteriae, Shigella flexneri, Shigella sonnei and E. coli) especially at concentration 100 µg/ml in contrast with the control cefotan antibiotic. S. sonnei was more sensitive to extract than other bacteria with highest inhibition zone (23 mm). The preliminary phytochemical tests results indicated the presence of alkaloids, saponins, flavonoids, terpenoids, glycosides and phenols, while tannins and reducing sugars absence in the extracts. Water extract (at concentration 100 µg/ml) caused 74.6% lipid peroxidation inhibition of linoleic acid emulsion, this activity was greater than other concentrations (25 and 50 µg/ml) and standard α-tocopherol (63%). Also, it was found that aqueous extracts decreased the adherent growth of bacteria on glass tubes. The results indicated that all isolates have the ability to form biofilms with different thickness degrees, the absorbance values were ranged between (1.04 - 1.68), the Salmonella isolate was the best isolate formed biofilm with highest absorbance value (1.68). On the other hand C. officinalis extract inhibited bacterial adhesion on polystyrene surface and consequently caused biofilms detachment and this revealed decreased in absorbance values of biofilms. These reported activities for C.officinalis flowers extract allow their listing as potential antibiofilm, antibacterial and antioxidant natural agents. This might suggest their use as therapeutic agents for treatment enteric infections.
Unconfined compressive strength (UCS) of rock is the most critical geomechanical property widely used as input parameters for designing fractures, analyzing wellbore stability, drilling programming and carrying out various petroleum engineering projects. The USC regulates rock deformation by measuring its strength and load-bearing capacity. The determination of UCS in the laboratory is a time-consuming and costly process. The current study aims to develop empirical equations to predict UCS using regression analysis by JMP software for the Khasib Formation in the Buzurgan oil fields, in southeastern Iraq using well-log data. The proposed equation accuracy was tested using the coefficient of determination (R²), the average absolute
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يتكون الانحدار المقسم من عدة أقسام تفصل بينها نقاط انتماء مختلفة، فتظهر حالة عدم التجانس الناشئة من عملية فصل الأقسام ضمن عينة البحث. ويهتم هذا البحث في تقدير موقع نقطة التغيير بين الأقسام وتقدير معلمات الأنموذج، واقتراح طريقة تقدير حصينة ومقارنتها مع بعض الطرائق المستعملة في الانحدار الخطي المقسم. وقد تم استعمال أحد الطرائق التقليدية (طريقة Muggeo) لإيجاد مقدرات الإمكان الأعظم بالأسلوب الت
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In this work, a Photonic Crystal Fiber (PCF) sensor based on the Surface Plasmon Resonance (SPR) technology was proposed. A thin layer of gold (Au) was deposited on a D-shaped Photonic Crystal Fiber (PCF), which was coated with plasmonic chemically stable gold material with a thickness of 40nm. The performance parameters like sensitivity including wavelength sensitivity and amplitude sensitivity and resolution were evaluated by simulation using COMSOL software. The proposed sensor was created by using the finite element approach, it is numerically examined. The results show that the surface of D-shaped Photonic Crystal Fiber coated with Au behaves as a sensor to detect the refractive index (IR) of toxic metal ions. The impacts of the str
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