Biofilm formation is one of the biggest challenges of scientists. Role of heavy metals in forming biofilm is not clear enough. Here, the effect of lead on biofilm formation by Bacillus spp. isolated from soil in terms of biofilm formation and remove was studied. In present study, 10 isolates of Bacillus spp were isolated from soil. The ability of all isolates to form biofilm was evaluated. The effect of lead on biofilm formation was studied by adding lead (pb) before forming biofilm. In another experiment the lead was added after biofilm formation to study the effect of lead on biofilm remove. The current study, showed the ability of all studied isolates to form biofilm. Maximum biofilm formation by Bacillus spp isolate number 8 (B8) followed by B1 and B3. The lowest biofilm formation was found in case of isolate 4 (B4). The lead (50 ppm) reduced biofilm formation by B8, B1 and B3 isolates when the lead was used before biofilm formation (P <0.05). In another experiment the lead (50 ppm) was added after biofilm formation, it was observed that the biofilm formation was higher when the lead was added (after biofilm formation) as compared with control (serial distilled water) and the difference was significant (P<0.05). It can be concluded that the lead effect negatively on biofilm formation and positively on stability of biofilm.
This paper proposes and studies an ecotoxicant system with Lotka-Volterra functional response for predation including prey protective region. The equilibrium points and the stability of this model have been investigated analytically both locally and globally. Finally, numerical simulations and graphical representations have been utilized to support our analytical findings
This research worked on identifying the effect of increasing the volume of indebtedness by companies listed on the Iraq Stock Exchange on the trading volume of those companies, and this research included some theoretical concepts related to both debt financing and trading volume, and it represents the research community of the joint-stock companies listed in The Iraq Stock Exchange (the banking sector). As for the research sample, it was deliberately chosen represented by companies with continuous trading without stopping, which reached 10 joint-stock companies, and the period of research was extended during the period 2011-2015, and a set of indicators and financial methods were used In measuring research v
... Show MoreRock failure during drilling is an important problem to be solved in petroleum technology. one of the most causes of rock failure is shale chemical interaction with drilling fluids. This interaction is changing the shale strength as well as its pore pressure relatively near the wellbore wall. In several oilfields in southern Iraq, drilling through the Tanuma formation is known as the most challenging operation due to its unstable behavior. Understanding the chemical reactions between shale and drilling fluid is determined by examining the features of shale and its behavior with drilling mud. Chemical interactions must be mitigated by the selection of suitable drilling mud with effective chemical additives. This study is describing t
... Show MoreThe article is devoted to the issue of word-formation motivation, which does not lose its relevance and plays a role not only in disclosing formal-semantic relations between words of one language and has not only theoretical, but also applied significance. The authors consider word-formation motivation consistently in its varieties in a comparative way on the materials of so different languages as Russian and Arabic and approach the mechanism of achieving semantic equivalence of translation. To the greatest extent, word-formation activity today, due to objective reasons, affects some special branch (technical, medical, etc.) vocabulary, which is increasing from year to year in national dictionaries. This extensive material, selected
... Show MoreThe early Carboniferous Harur Formation from the Ora outcrop section of northern Iraq consists of black shale, calcareous shale and carbonate. The mineralogical and geochemical investigations (major and trace elements) of the black shale and calcareous shale units have been conducted to evaluate paleoenvironmental conditions including paleoclimate, paleoredox conditions, paleoproductivity, sedimentary rate, and to evaluate their effects on organic matter accumulation. The geochemical proxies such as the Chemical Index of Alteration (CIA), A-CN-K plot, Sr/Cu ratio, and the relation between the ratio of Ga/Rb and Sr/Cu suggest moderate to intense chemical weathering under humid conditions. The Rb/K and Sr/Ba ratios indicate a freshw
... Show MoreThis study deals with the biostratigraphy of Shiranish Formation (Late Cretaceous), depending on the Ammonite and associated Foraminifera in four outcrop sections, three of which are located in Al-Sulaimaniya governorate (Dokan, Esewa and Kanny dirka sections) and one in Erbil governorate, northern Iraq (Hijran section). Fourteen species of Ammonite belonging to fourteen genera were determined, which are: Dsemoceratidae, Gaudryceras, Gunnarites, Hoplitoplacenticeras, Kitchinites, Kossmaticeratinae, Neancyloceras, Neokossmaticeras, Nostoceras, Paratexanites, Partschiceras, Phylloceras, Pseudophyllites and Yubariceras. Also, thirty- five species of Foraminifera belonging to thirteen genera w
... Show MoreThe outcrop sections of Ora Formation (late Devonian-Early Carboniferous) in the Nazdor and Ora localities at the Northern Thrust Zone of Iraq were selected for this study. Lithologically the Ora Formation composed of clastic and carbonate rocks. The lower part in the Nazdor section cosists of crossbedded quartz arenite sandstone interbedded with successive laminated siltstone and shale. The lithology of the upper part in the Nazdor section and the upper part in Ora section, are composed of mixed silicalcastic (shale, siltstone and sandstone) and carbonate interbedded lithology. The petrographic study shows that the carbonate rocks consist of micrite and sparite groundmass. The skeletal grains include shallow water brachiopods, bryozoans
... Show MoreThe Amarah Oil field structure was studied and interpreted by using 2-D seismic data obtained from the Oil Exploration company. The study is concerned with Maysan Group Formation (Kirkuk Group) which is located in southeastern Iraq and belongs to the Tertiary Age. Two reflectors were detected based on synthetic seismograms and well logs (top and bottom Missan Group). Structural maps were derived from seismic reflection interpretations to obtain the location and direction of the sedimentary basin. Two-way time and depth maps were conducted depending on the structural interpretation of the picked reflectors to show several structural features. These included three types of closures, namely two anticlines extended in the directions of
... Show MoreThe aim of this study is to investigate the sedimentation environments and diagenetic processes of the Ibrahim Formation (Oligocene-early Miocene) in Zurbatiya, eastern Iraq. The Ibrahim Formation is comprised mostly of clayey micrite and skeletal grains composed of planktonic foraminifera, calcispheres, radiolaria, and benthic foraminifera. Glauconite and pyrite were documented in some restricted zones of this formation; they reflect quiet and reducing conditions. Radiolaria were identified in Late-Oligocene which was not known previously at this age regionally in carbonate formations of the Arabian Plate (AP). Mudstone, wackestone, and planktonic foraminiferal wackepackstone are the main microfacies that are affected by dissolutio
... Show MoreThis research studies the petrography, mineralogy and diagenetic history of the Sarmord Formation at Sulaimani and Erbil Governorates in Northeastern Iraq. The Sarmord Formation consists mainly of alternated yellowish to bluish gray bedded marly limestone with yellowish gray soft marl beds. Petrographic investigations of the marly limestones were based on 270 thin sections and show that the skeletal grains include bioclasts, foraminiferas, radiolarians, calcispheres, echinoderms, ostracods and cephalopods. The groundmass is composed of micrite with light brown to gray colors, rich in organic materials and iron oxides. The X-ray diffraction analysis of the marls revealed that the abundant clay minerals in the Sarmord Formation ar
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