Facies analysis and stratigraphic development of the Albian Succession in Nasiriyah Oil Field, Southern Iraq

The Carbonate - Clastic succession in this study is represented by the Nahr Uamr and Mauddud Formations deposited during the Albian Sequence. This study includes facies analysis and stratigraphic development for this succession in 5 boreholes within Nasiriyah oil field. There are several types of microfacies were recognized in the succession of the Mauddud Formation. Their characteristic grain types and depositional texture enabled the recognition of six facies associations (depositional environments) were distinguished in the Mauddud Formation, they are: shallow open marine, restricted, reef, slope, deep open marine and basinal. Two types of rocks are observed within the Nahr Umr Formation; the first is the upper part which characterized by shale dominated rocks and the second (lower part) is characterized by sand dominated rocks. Four facies associations (depositional environments) were distinguished in the Nahr Umr Formation, they are: delta plain, prodelta, bay fill, and distributary channels. The microfacies analysis and reconstructed the paleoenvironments of the Albain basin in the studied area; there are three stages of the deposition: - during the first stage the sea level was rise which led to progress prodelta facies (retrogradation) and onlapping the unconformity. This part is represented by TST stage in all studied boreholes. The prodelta facies was changed to distributary channel facies up-wared to mark the mfs between these two facies. This refers to deposition during the high stand period as two cycles. The sea level was reactivated to progress after the last step of Nahr Umr deposition, to start the Mauddud Formation deposition. At second stage the facies change was shown three steps of the sea level rise (TST) to deposition the restricted, reef-back reef and shallow open marine/slope. Overlying the slope facies to the shallow marine and then deposited the shallow marine refer to maximum flooding surfaces after deposition the last ones. Therefore, the shallowing up-ward succession which deposition later was represented the high stand stage (HST). The final stage is represented by reactivated the sea level rise to deposition the basinal facies within the Mauddud Formation. The continued rise in sea level during the period of transgression (TST) is a preparation for the Ahmadi basin, which is characterized by deposition in a deep environment and conformable lower contact with the Mauddud Formation

Petro physical Evaluation and Reservoir Characterization of the Zubair Formation in Majnoon oil field, Southern Iraq.

The Barremian succession in the present study is represented by the Zubair Formation which the most significant sandstone reservoir in Iraq. The area of study is located in the Southern part of Iraq at Majnoon oil field, within the Mesopotamian basin. The thickness of the Zubair Formation is about 450 m in the studied area. It is divided into three lithofacies: The upper unit is composed mostly of shale layers, the middle unit is consisting of thick layers of sandstone rocks and the lower ones is consisting mainly of Shale with less sandstone layers. These units are characterized by three types of petrophysical features according to total porosity/effective porosity: High-moderate effective porosity rocks (type I), moderate effective porosity rocks (type II) and low-non pores rocks (type III). The upper unit of the Zubair Formation at Majnoon oil field is characterized by two horizons. The first is showing high resisitivity-high gamma ray which represent the upper part, while the lower part show low resisitivity-low gamma ray. There is a good reservoir horizon with high oil saturation (low water saturation) in this unit at the Majnoon oil field is appeared as a non-continuous horizon. The middle member is dominated by low resistivity-low gamma ray. The high percentage of water saturation in this unit caused the lack of clarity of the oil saturation, which appears in a narrow band. The lower member of Zubair Formation is distinguished by shale dominated rocks and poor sorted sandstone. This shows high resisitivity-high gamma ray. There are many sub horizons as bands within the lower horizon as high resistivity-low gamma ray. There is a good reservoir horizon with high oil saturation (low water saturation) in this unit

Significance of nutrient and water sustainability: Effect of land leveling, cut off irrigation and N- fertilization on maize yield

A wide variety of soil, nutrient, and irrigation management practices are available to farmers, most of them concerned with the basic building block of agriculture, the soil. Soil management practices include the tillage and cropping systems and crop rotations used on a farm. Therefore, sustainable crop production should be managed to enhance soil ecosystems, improving soil health and fertility and reversing degradation and pollution of land. As well as, it should be contributed to maintaining and improving, and efficiently utilizing, water resources (quantity, access, stability and quality), especially promoting practices that minimize risks of water pollution from agrochemicals and save water. It is well documented that fertilizer N is the most costly input in maize production and its effective management is a major challenge for improving productivity and environmental sustainability. In present study, the effect of land leveling, cut off irrigation and N- fertilizer on yield and yield components of maize have been studied. The results showed that the highest yield of grain and straw of maize was obtained with using N-fertilization rate 288 kg N ha-1, land levelling rate 0.01 % of surface slope and cut off stream of irrigation rate 75%. The results of this study suggest that, irrigation application efficiency (%) increased from 71 % (for control) to 80 % for cut off 75 % of stream irrigation and land leveling with 0.01 % slope. Thus, about 20 % from the applied water for irrigation is saved by the previous treatments

Accretion-powered chromospheres in classical T Tauri stars

(Abridged) Optical spectra of classical T Tauri stars (cTTS) are rich in emission lines of low-excitation species that are composed of narrow and broad components, related to two regions with different kinematics, densities, and temperatures. The photospheric spectrum is often veiled by an excess continuous emission. This veiling is usually attributed to radiation from a heated region beneath the accretion shock. The aim of this research is to clarify the nature of the veiling, and whether the narrow chromospheric lines of Fe I and other metals represent a standard chromosphere of a late-type star, or are induced by mass accretion. From high-resolution spectroscopy of DR Tauri we found that the amount of veiling in this star varies from practically nothing to factors more than 10 times the stellar continuum intensity, and that the veiling is caused by both a non-photospheric continuum and chromospheric line emission filling in the photospheric absorption lines. This effect can be shown to exist in several other T Tauri stars. We conclude that enhanced chromospheric emission in cTTS is linked not only to solar-like magnetic activity, but is powered to a greater extent by the accreting gas. We suggest that the area of enhanced chromospheric emission is induced by mass accretion, which modifies the local structure of stellar atmosphere in an area that is more extended than the hot accretion spot. The narrow emission lines from this extended area are responsible for the extra component in the veiling through line-filling of photospheric absorption lines.Comment: 11 pages, 13 figure

Synthesis and Biocidal Activity of Some Naphthalene-Based Cationic Surfactants

In this study, different cationic surfactants were prepared by reacting dodecyl bromide with tertiary amines to produce a series of quaternary ammonium salts that were converted subsequently to stannous and cobalt cationic complexes via complexing them with stannous (II) or cobalt (II) ions. Surface properties such as surface- and interfacial-tension, and the emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, minimum surface area, tension lowering efficiency and effectiveness were studied. The free energy of micellization and adsorption were calculated. Antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which was measured against six strains of a representative group of microorganisms. The antimicrobial activity of some of the prepared surfactants against sulfate reducing bacteria was determined by the dilution method. FTIR spectra, elemental analysis and a H1 NMR spectrum were examined to confirm compound structure and purity. The results obtained indicate that these compounds have good surface properties and good biocidal effect on broad spectrum of micro organisms

Cationic surfactant based on alignate as green corrosion inhibitors for the mild steel in 1.0 M HCl

Three cationic surfactants based on alginic acid were laboratory prepared. These compounds were evaluated as corrosion inhibitors utilizing three techniques, namely; weight loss, polarization and electrochemical impedance spectroscopy. The corrosive medium was 1.0 M HCl. The corrosion rate of mild steel in 1.0 M HCl at four different temperatures 25, 40, 55 and 70 °C was investigated gravimetrically. The corrosion rate of mild steel was confirmed electrochemically at 25 °C. It was found that the corrosion inhibition efficiency directly proportionally with the hydrophobic chain length of synthesized inhibitors and also with the plethora of concentration. The inhibition efficiency exhibit a positive trend with raising the solution temperatures as indication for chemisorption. The potentiostatic polarization study revealed that the tested green cationic surfactants act as mixed type inhibitors with predominant control of cathodic reaction. The decreasing in the double layer capacitance obtained from electrochemical impedance measurements refer to increasing the thickness of the formed double layer. The apparent activation energy of the inhibited solution was found to be lower than uninhibited solution as an indication for chemical adsorption

BEHAVIOR OF DELAYED ADDITION TIME OF SNF SUPERPLASTICIZER ON MICROSILICA-SULPHATE RESISTING CEMENTS

Most concrete produced today includes either chemical additions or chemical admixtures added to concrete, or both. These additives alter the properties of cementitious systems, including fluidity, hydration kinetics, microstructure and strength. Therefore, the development and use of the most suitable type, optimum dosage and delayed addition time (DAT) of superplasticiser in concrete technology have been of increasing importance. The present investigation aimed to evaluate the influence of DAT of sulfonated naphthalene formaldehyde (SNF) condensate on the hydration kinetics of sulfate resisting cement (SRC) pastes incorporating 10 mass % silica fume (SF). Superplasticized cement pastes were prepared using the required water of standard consistency with different dosages and DAT of SNF. The pastes were hydrated for 90 days under normal curing conditions. The results revealed that, the fluidity of cement pastes increases with SNF content and DAT up to 7.5 minutes, due to the electrostatic repulsion between cement particles and the decrease of anhydrous C3A content that is minimized with hydration time. Also, the chemical and physico-mechanical characteristics improve with superplasticizer dosage up to 1.0 mass % and DAT up to 7.5 minutes, due to the improvement of superplasticizing effect, leading to increase the hydration of silicate phases (C3S and β-C2S) and formation of more CSH, CAH and CASH. These hydrates increase the gel/space ratio, modify the microstructure and consequently enhance the strength of cement paste. FTIR spectra are in a good agreement with those of chemical and physico–mechanical characteristics

Characterization of bioactivity in transition metal doped-borosilicate glasses by infrared reflection and dielectric studies

880-888Borosilicate glasses with the addition of one of the 3d-transition metals (Ti→Cu) (0.1 g/100g glass) have been investigated as possible materials having bioactivity by infrared reflection spectroscopy and electrical properties after the immersion in simulated body fluid (SPF) for different interval of times. The results show obvious effects of the transition metal ions on the bioactivity of the borosilicate glasses. The results are discussed taking into consideration recent achievements that govern the formation of hydroxyapatite surface layer on glass. Also, IR and electrical results are discussed in relation to the glass composition and structure, which confirm the effect of the formation of HAp layer and the possible mixed ionic and electronic mechanisms due to the addition of transition metal oxides