44 research outputs found
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
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
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
Yield of wheat is increased through improving the chemical properties, nutrient availability and water productivity of salt affected soils in the north delta of Egypt
The lysimeter experiment was carried out twice in consecutive two years (2014-15 and 2015-16) at Sakha Agricultural Research Station, Kafrelsheikh, Egypt to study the effect of three irrigation levels water (i.e., 100, 110 and 120% field capacity (FC), two rates of gypsum (G) (i.e., 50 and 100% G) and three sources of nitrogen (90 kg nitrogen (N), 10 t compost (C) and 7.5 t C + 45 kg N (CN) fed-1 (fed = 4200 m2)) on grain yield of wheat, water relations and soil chemical properties. Water consumptive use (WCU) was markedly increased due to the increase of the level of irrigation, rate of gypsum (G) and CN source (7.5 t C + 45 kg N fed-1). Irrigation with water amount equal to 120% FC recorded the highest values of WCU 1433 and 1570 m3fed-1 in both seasons. Water productivity (kg grain m-3 water) for either water application (WA) in both seasons or WCU in the second season was decreased by increasing level of irrigation from 100 to 120% FC in the second season, while the inverse was true for WCU in the first season. The highest mean values of water productivity for WCU 1.816 and 1.791 kg m-3 were obtained with the irrigation level of 120% FC in the first season and 100% FC in the second season, respectively. Gypsum rate and N source have an effect on the productivity of irrigation water (WP) for WA and WCU, where the highest mean values for both the two irrigations efficiency were recorded under 100% G requirements and CN (7.5 t C + 45 kg N fed-1). The interaction of 110% FC × 100% G × 7.5 t C + 45 kg N fed-1 produced the highest values of WP for WA (1.245 and 1.374 kg grain m-3 WA) in both seasons. Grain yield fedd.-1 was increased significantly with the irrigation level from 100 to 120% FC in both seasons, G rate and CN source. Grain yield (GY) did not differ significantly due to the levels of irrigation water between 120 and 110% FC in both years. Application of 100% G and 7.5 t C + 45 kg N fed-1 at any irrigation level were among those treatments having high GY, being insignificant. The mean values of electrical conductivity (acidity; ECe) and soil sodicity (SARe) were affected by irrigation treatments, G rates and nitrogen sources. A stronger reduction in soil ECe and SARe were recorded under the irrigation level of 120%FC, 100% G and 10 t compost in both seasons. While the soils ECe and SARe were increased by application of chemical N fertilizer alone or with compost. Therefore, it can be concluded that irrigation with water amount equal to 110 or 120% FC, 100% G requirements and 7.5 t C and 45 kg N fed-1 was the best treatment for getting high GY, improving the soil chemical properties, nutrients availability and increasing the water productivity of salt-affected soil in North Delta of Egypt. © 2019, ALÖKI Kft., Budapest, Hungary
Combined Application of Compost, Zeolite and a Raised Bed Planting Method Alleviate Salinity Stress and Improve Cereal Crop Productivity in Arid Regions
Soil salinity and climate change have a negative impact on global food production and security, especially in arid regions with limited water resources. Despite the importance of planting methods, irrigation, and soil amendments in improving crop yield, their combined impact on saline soil properties and cereal crop yield is unknown. Therefore, the current study investigated the combined effect of soil amendments (i.e., compost, C and zeolite, Z) and planting methods such as raised bed (M1) and conventional (M2), and different fractions of leaching requirements from irrigation water, such as 5% (L1) and 10% (L2), on the soil physio-chemical properties and wheat and maize productivity in an arid region. The combined application of C + Z, L2, and M1 decreased soil salinity (EC) and sodicity (ESP) after wheat production by 37.4 and 28.0%, respectively, and significantly decreased by these factors by 41.0 and 43.0% after a maize growing season. Accordingly, wheat and maize yield increased by 16.0% and 35.0%, respectively under such a combination of treatments, when compared to crops grown on unamended soil, irrigated with lower leaching fraction and planted using conventional methods. This demonstrates the significance of using a combination of organic and inorganic amendments, appropriate leaching requirements and the raised bed planting method as an environmentally friendly approach to reclaiming saline soils and improving cereal crop production, which is required for global food security