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

Petrophysical Evaluation and Reservoir Characterization of the Zubair Formation in the Luhais and Rachi oil fields, 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 the Luhaisand Rachi oil fields, 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 consists of thick layers of sandstone rocks and the lower ones is consists 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 theZubair Formation at the Luhais oil field is characterized by two horizons. The first is showing high resistivity-high gamma ray which represents the upper part; while the lower ones is shown low resistivity-low gamma ray. There are two good reservoir horizones with high oil saturation (low water saturation) in this unit at the Rachi oil field and Lu-3 borehole, while at the Lu-12 is appeared as one uncontaneoushorizon. The middle is characterized by two subzones in the southwestern part of Luhais oil field (Lu-12). The upper one characterized by high- moderate effective porosity while the lower one characterized by moderate effective porosity because of presence a low volume of shale. This unit is dominated by low resistivity-low gamma ray with three susbended bands of high resistivity-low gamma ray, these appeared in both studied oil fields. The high percentage of water saturation in this unit caused the lack of clarity of the oil saturation, which appears in narrow bands The lower unit is represented the shale – dominated member of Zubair Formation, with low to non-pores rocks. This appeared in all studied wells. There are limit presences for the high- moderate effective porosity of rock within the sand bands lithofacies appears in these wells. This unit is characterized by alternative the high resistivity-high gamma ray horizon with the low resistivity-low gamma ray horizon as four cycles. There are two good reservoir horizons with high oil saturation (low water saturation) in this unit with a distribution similar to that found in the upper part. From the reservoir geology which represent by property modelling, preparing data, construction of three-dimension clump and scale up for the studied oil fields. The Rachi oil field is appeared the better hydrocarbon saturation compared to Luhais oil field, although the Luhais oil field (Lu-3 and Lu-12) is the best of pertophysicalproperties. This indicates that the Rachi oil field was affected by the structural position as indicated by the model, while the model did not show any structural properties in the field of Lahis. Therefore, the structural and/or stratigraphic positions have the greatest influence on the hydrocarbon accumulation, regardless of petrophysical properties

Water quality problems in irrigated agriculture in Libya

The Kufra region of south eastern Libya comprises an area about 850 km south to north, and some 500 km wide rising to 450 m above sea level. Rainfall is low and agriculture depends on irrigation. Most of the population of Kufra are private farmers who use flood irrigation from shallow wells (19-60 m), but there are co-operatives of farmers that have shared the cost of deeper wells (120 - 150 m) and sprinkler irrigation. The Kufra Agricultural Project (KAP) state farm is made up of 100 circles (farms) each having its own deep well (220 – 352 m) and rotary sprinkler. The experimental work was conducted in three phases. An initial study was made of soil profiles and irrigation water on 4 private and 4 state farms. An inter laboratory study compared results in the KAP and Glasgow University (GU) laboratories. The third phase was a survey of top soils, irrigation water, crop yield and questionnaires for a much larger number of farms. Chapter 3 describes the comparison between chemical analysis results of 33 soils in the KAP and GU laboratories. There was a good level of agreement between the two laboratories. The high correlation coefficients indicate a high level of precision in both laboratories. However there were systematic differences between the two laboratories, results for EC, Ca2+, Mg2+ and Cl- were 2% to 6% lower in the KAP laboratory. There were no significant differences in the results for Na+ and K+ between the laboratories. It is important that all analyses were carried out in one laboratory, so all subsequent samples were sent to the KAP laboratory. Chapter 4 evaluates the quality of irrigation water from 86 wells in the Kufra region in line with FAO and USDA standards for irrigated agriculture. pH, EC, Ca2+, Mg2+, Na+ and SAR were not significantly affected in state farms by well depth or age, but were significantly affected in the private farms by well depth, where the values were higher in shallow wells and significantly related to well age. There are two responses to well age related to well depth shown by two distinct lines. The shallow wells (30 m) exhibits no significant effect of well age (p> 0.05). USDA classification indicates that the water of all the wells of private farms is unsuitable for irrigation purposes. The FAO criteria showed that all private wells had limitations on use due to salinity and SAR. (EC: 78% severe, 22% slight/moderate ; SAR: 35% severe, 65% slight/moderate) Chapter 5 describes a survey of soil profiles from state and private farms. Irrigation lowered the salinity of the virgin soil profiles, with a clear distinction observed between the virgin and irrigated profiles for EC and water soluble Ca2+, Mg2+, Na+, K+, Cl- and SO42- in state farms, and for EC and water soluble Na+, Cl- and SO42- in private farms. In the virgin soil profiles, these parameters showed a clear decrease with depth, while in the irrigated soil profiles they were much lower in concentration and more uniform with depth. There was no clear trend with depth in irrigated soil profiles for pH, HCO3-, CaCO3%, exchangeable cations, and ESP % in the state farms and for pH, water soluble Ca2+, Mg2+and K+, CaCO3%, exchangeable cations, and ESP% in the private farms. The profile averages for pH, EC, ESP%, water soluble Na+, Cl-, HCO3- and SO42- and exchangeable sodium were significantly greater (t-test, p≤0.05) in the irrigated profiles of private farms than in KAP farms. The irrigated topsoils (0–25 cm) showed similar results except that bicarbonate and sulphate were not significantly different. The second part of chapter 5 describes a larger survey of irrigated topsoils. This showed that the pH, EC, ESP% and exchangeable Na+ were much higher in the private farms compared to state farms soils. According to the USDA classification all state farm soils were classed as normal, while 70% of private farm soils were classed as saline alkaline, 15% normal, 10% saline and 5% alkaline. There was no significant effect of crop type on any soil parameter for state or private farms. There was no significant correlation in the combined data for state and private farms between irrigation water and soil for pH, Ca2+ and Mg2+ but there is for EC, Na+ and SAR. In all the graphs there are 2 clusters of points separating the state and private farms which masks the correlation relationship. Chapter 6 compares the yields of alfalfa and potatoes in the state and private farms. The mean values for dry yield of alfalfa from state (6.32 t/ha) and private (3.06 t/ha) farms were significantly different (p<0.001, pooled t-test). The age of the alfalfa crop had a significant (p<0.001) positive effect on yield in the state farms, but a significant (p<0.001) negative effect in private farms. Crops on the private farms were 2 to 8 years old compared with under 2 years on the state farms. Although there were low yields at high values of water and soil parameters (private farms) and high yields at low values of water and soil parameters (state farms) plotting yield against these parameters shows 2 clusters. Looking at the private farms alone there was no significant correlation between alfalfa yield and any of the quality parameters for soil or water. No potatoes were grown on state farms when the samples were collected, so historical data was used (average yield 40 t/ha). The mean yield of potatoes from private farms was significantly lower (p<0.001) 23.16 t/ha. None of the correlation relationships between crop yield with soil and water quality parameters for private farms was significant. Despite the large differences in soil and irrigation water chemistry between state and private farms, there was no evidence that poor irrigation water quality or soil salinity currently limits production on private farms. Chapter 7 describes the survey of private farmers and shows that 81% of respondents did not consider farming as a professional activity they could rely on, but rather an activity to fill their free time. The study also examined other aspects including the farmers’ education level, the farms’ age, irrigation and the impact of water salinity, types and sources of fertilisers. The study concluded that traditional agricultural systems in this region are not built on a scientific basis, or an adequate knowledge of economic feasibility. Consequently, the production rates of agricultural crops are very low

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

Enhancement of antifungal activity and transdermal delivery of 5-flucytosine via tailored spanlastic nanovesicles: statistical optimization, in-vitro characterization, and in-vivo biodistribution study

Aim and background: This current study aimed to load 5-flucytosine (5-FCY) into spanlastic nanovesicles (SPLNs) to make the drug more efficient as an antifungal and also to load the 5-FCY into a hydrogel that would allow for enhanced transdermal permeation and improved patient compliance.Methods: The preparation of 5-FCY-SPLNs was optimized by using a central composite design that considered Span 60 (X1) and the edge activator Tween 80 (X2) as process variables in achieving the desired particle size and entrapment efficiency. A formulation containing 295.79 mg of Span 60 and 120.00 mg of Tween 80 was found to meet the prerequisites of the desirability method. The optimized 5-FCY-SPLN formulation was further formulated into a spanlastics gel (SPG) so that the 5-FCY-SPLNs could be delivered topically and characterized in terms of various parameters.Results: As required, the SPG had the desired elasticity, which can be credited to the physical characteristics of SPLNs. An ex-vivo permeation study showed that the greatest amount of 5-FCY penetrated per unit area (Q) (mg/cm2) over time and the average flux (J) (mg/cm2/h) was at the end of 24 h. Drug release studies showed that the drug continued to be released until the end of 24 h and that the pattern was correlated with an ex-vivo permeation and distribution study. The biodistribution study showed that the 99mTc-labeled SFG that permeated the skin had a steadier release pattern, a longer duration of circulation with pulsatile behavior in the blood, and higher levels in the bloodstream than the oral 99mTc-SPNLs. Therefore, a 5-FCY transdermal hydrogel could possibly be a long-acting formula for maintenance treatment that could be given in smaller doses and less often than the oral formula

Evaluation of journal bearings characteristics using finite element method

Dynamic behavior of the rotor-bearings system exerts a considerableinfluence on rotating machine operating and stability. Indeed, vibrations insuch machines may cause not only high level of noise but also wearing ofmoving components. Hydrodynamic journal bearings, which are among thebest devices to prevent contacts between rubbing surfaces, are analyzed inthe present study by considering dynamic effects due to flexibility of thelubricant fluid film. The finite element method is used to numericallyevaluate stiffness and damping coefficients of the fluid film and applicationsconcern performances of finite length and aligned journal bearings. Resultsare compared with those obtained by an alternative method and show goodagreement.Keywords: Journal bearings, Dynamic characteristics, Finite elemen

Effect of Gamma Rays on Some Stages of Development of Rhyzopertha dominica (Fab.)

The effect of different doses of gamma rays that emitted from 60Co on the development of different stages of lesser grain borer Rhyzopertha dominica (Fab.) was investigated . The results showed that the eggs in both early (1-3 days) and late (7-9) old were very sensitive to gamma rays and its hatch was zero at 10 Gy for both ages in comparison with 83.3% for the control group. Furthermore, the results illustrated that the larval stage in its two old ages were different in the radiosensitivity, the percent of its death were 100% & 96.6% when they exposed to 100 & 120 Gy, respectively. Moreover, the results showed that the sensitivity of pupal stage at age of 1-3 days was increased with increasing the doses of gamma rays, the percent of normal adults eclosed from irradiated pupae was 83.3% at the dose of 20 Gy and it became 3.3% at the dose of 200 Gy in comparison with that of the control treatment which was 93.3%