Oil families and petroleum geochemistry of the western part of the Sirt Basin Libya

PhD ThesisThis thesis describes a detailed geochemical evaluation of the hydrocarbon potential of source rocks and the origins of the crude oils in the western and central parts of the Sirt Basin in Libya. The Sirt Basin is one of North Africa's richest and most prolific oil-bearing basins, with most of the oil being considered to be derived from the Campanian Sirte Shale and other local source rocks such as Rachmat, Etel and Hagfa Shale formations. The primary aims of this research were to determine the main source rocks that generated petroleum, determine the number of genetically distinct oil families in the basin and compare them with their parent source rocks, and to assess the regional migration and the filling directions of the reservoirs, since this information can exert a profound influence on current and future exploration activities across the study area. A study was undertaken on these source rocks and crude oils using 269 rock cuttings and 51 crude oil samples from several boreholes and oilfields in the Sirt Basin. Routine geochemical analysis in addition to biomarker analysis by gas chromatography-mass spectrometry, compound specific carbon isotopic analysis on n-alkanes and diamondoid analyse were carried out on selected source rock samples and on all of the crude oil samples. The geochemical results demonstrated the presence of various organic-rich zones within the Upper Cretaceous Sirte Shale and Rachmat source rocks. The Sirte Shale Formation is considered to have variable fair, good to very good source potential, and has good hydrocarbon generation in the study area. The Rachmat Formation shale is considered as the second potential source rock in the basin. Vitrinite reflectance, Spore Colour Index, and pyrolysis Tmax data indicate that the Upper Cretaceous shale samples are early to mid-mature in the west of the basin, and middle to late mature in the north central of the basin. Optical analysis of palynofacies slides showed that structureless, amorphous organic matter is dominant, along with the presence of some phytoclasts and reveals moderate to well preserved, fluorescent Type II marine kerogen and Type II-III kerogen. A number of biomarker and other organic facies and maturity indicating molecular marker parameters, as well as isotopic data, show that the crude oils in the western and v central parts of the Sirt Basin are genetically related and only minor variations are present between them, likely due to minor organic facies variations in the Sirt Shale and Rachmat source rocks. The biomarker parameters show dissimilarities between the crude oils in eastern part relative to the western and central part of the basin, due to variations in the organic facies and depositional environments setting of the source rocks or due to higher maturity. Based on molecular marker characteristics, oil-oil correlation identified nine oil families, plus two subfamilies in the study area: Oils from families 1A, 1B, 2, 3 and 4 are situated in the western and central parts of the Sirt Basin, while oil families 5, 6, 7, 8 and 9 are located in the eastern part of the basin. Crude oils of families 1A, 1B, 2, and 3 were interpreted as having been generated from a suboxic to anoxic marine, clay-rich and early to middle maturity source rock. Molecular and other compositional variation between oil families were attributed to organic facies and subtle maturation variations. Age-related biomarker parameters in the oils suggested that their source was Upper Cretaceous. Migration of the generated and expelled oil and gas from the Sirte Shale and Rachmat source rocks to the reservoirs of the Upper Cretaceous-Tertiary petroleum system was interpreted to have occurred along both vertical and lateral pathways along the faults, in the Oligocene to Miocene, while oil carbazole data indicated that this migration was generally likely to have been over relatively short distances.Libyan petroleum Institut

Determinants of tax administration efficiency in Libya

Tax is one major source of government revenue, however, not every national government has been able to effectively exploit this great opportunity of revenue generation. The tax is collected at very lower level because of the inefficiency of tax administration in Libya. The purpose of this study is to investigate the determinants of tax administration efficiency from the Libyan perspective. This study is based on five variables that are used to determine the factors that affect tax administration efficiency in Libya. The five variables that are measured in this current study are autonomy, motivation, information and communication technology ICT, training and leadership style. The data were collected through the distribution of questionnaires to 250 respondents in Libya. 161 out of 250 questionnaires were sufficient and a valid rate for the analysis by using the Partial Lease Square-Structural Equation Modeling (PLS-SEM) software. By using correlation and regression analyses, the outcomes of the study show that there is a positively and significant relationship between motivation, ICT training and leadership style with tax administration efficiency. On the other hand, autonomy indicates a negative and insignificant relationship with tax administration efficiency

An unusual metastatic site of head and neck cancer; Case Report and literature review

The annual occurrence of Head and Neck caner (HNC) is documented to be more than 650,000 cases with 330,000 deaths. In the United States, it represents 3% of all malignancies and affects 53,000 Americans. Metastasis to the lung, liver and bones are considered the most common locations. Herein, We are reporting a case of HNC and an unusual synchronous gastric metastasis found on an upper gastrointestinal endoscopy (EGD) after CECT scanning of Abdomen shows only the mass that related to stomach fundus and MRI pelvic no mass could be seen. Both cancers were poorly differentiation on histopathology, which raises the flag of possible disease aggressiveness and poor treatment respons

Diatom Assemblage in the Lake of Gaberoun, Southern Libya

The lake of Gaberoun in the southern district of Libya was studied to assess the diatom community composition in the littoral zone. Planktic and attached diatoms were listed and information on the constituent species made known (images are shown). Some criteria of the water characteristics are also given such as the pH, which is an average of 8.3, electrical conductivity which accounted for 1.4 µSim/cm1- and total dissolved salts (TDS) of 189.0mg/L1-

The effects of growth hormone receptor-associated ERK activation on adipocyte differentiation and function

Growth hormone (GH) modulates adipocyte function to promote lipolysis via a cell surface GH receptor (GHR) which activates multiple signalling cascades including STAT5 and p42/44 MAP kinase (MAPK) pathways. The growth promoting effects of GH are mediated primarily by STAT5 activation but little is known about pathways mediating the effects of GH on adipocyte function. We therefore studied the effect of GH on STAT5 and MAPK (ERK) activation in the 3T3-L1 mouse pre-adipocyte cell line during adipogenesis. Cells were plated, allowed to reach confluence and cultured in adipogenic medium containing the PPAR agonist, pioglitazone. GH induced activation (10 minutes exposure) of STAT5 and MAPK was analysed on days 0, 2, 5 and 8 during adipogenesis by phospho-specific western blotting and densitometry. During adipogenesis, GH progressively loses the ability to activate p42/44 MAPK despite elevated GHR and unaltered total ERK levels. In contrast, GH-stimulated STAT5 activation increases as 3T3-L1 differentiation proceeds. Subsequently we investigated possible explanations for the altered GHR signalling. The adapter protein p66Shc is thought to be necessary to link GHR activation to the ERK pathway. However levels of this protein, measured by western blotting and densitometry, did not decrease as 3T3-L1 cells underwent adipocyte differentiation. GHR levels increase with adipogenic differentiation of 3T3-L1 cells leading us to hypothesize that this may lead to preferential association with JAK2-STAT5. This was tested by overexpressing the GHR in 3T3-L1; similar GH-stimulated ERK pathway activation was obtained in cells transfected with the GHR vector and in those transfected with the empty vector. Finally, we have investigated whether changes in GHR signalling also occur during adipogenesis of primary pre-adipocytes from mice and various human depots. There was minimal GH-induced phosphorylation of ERK at all-time points before and during differentiation (required up to 15 days in primary cells) and no depot, either murine or human, demonstrated a reduction in p ERK, suggesting that this feature is unique to 3T3-L1. Furthermore, ERK phosphorylation may be the stimulus for mitotic clonal expansion which occurs in the cell line but not in human primaries. GH-stimulated STAT5 activation increases as human and mouse primary pre-adipocytes differentiation progresses, as in the 3T3-L1 cell-line, and may be the result of increased GHR transcript levels as differentiation proceeds. Future studies could investigate the mechanisms responsible for these similarities and differences

Achieving simulation as REBIANA Village Case Study of Photovoltaics System-Based Residential Distribution Grid

The growing demand for photovoltaic (PV)-based buildings and increasing utilization of DC electronic loads, along with decreasing DC appliances prices, have resulted in attraction of DC networks for residential consumers. The main aim of this paper is to present an economic study of a PV system-based DC residential distribution network. This includes designing and simulation of the system that is based on DC residential distribution network. Electrical Transient Analyzer Program (ETAP) software can be used for designing and modelling of the PV system components for a single house and for the distribution grid. The process starts with the PV module, DC/DC converter, battery, and the load. It takes into account all the ratings of the specific components for the whole system. Subsequently, the system efficiency has been evaluated for a common DC home at 24V, 48V, and 110V DC, and compared to the 220V AC through the simulation. Power losses will be through the conversion and distribution. Based on the obtained results using American Wire Gauge AWG-6 for a single house, it is found that the efficiency of a 48V DC system is higher than that of 220V AC system. It is also found that the usage of 48V DC leads to better efficiency compared with that of other system. This states that the efficiency of the system will increase with increasing of the main bus voltage. At the rest of the paper, the installed capacity for a single house is evaluated at 10 KW per house and this is results in a 2 MWp total installed PV system for 200 houses. This installed capacity can produce 4344 GWh per year. The installed PV system could improve the Libyan grid by reducing losses. Moreover, the installed PV capacity saves around 592,956,000 LD yearly and prevents emission of 328.82 million kg, 5,408,890 million kg and, 4963617743 million kg from gas, heavy fuel, and light fuel respectively

Bone Mineral Density Changes in Patients with Recent-Onset Rheumatoid Arthritis

Background Osteoporosis and related fragility fractures are one of the most common complications seen in patients with rheumatoid arthritis (RA) and dramatically affect quality of life. Objective To evaluate changes in bone mineral density in patients with recent onset rheumatoid arthritis (< 1 year) and its correlation if any with a modified DAS-28 score and simple erosion narrowing score (SENS). Methods This study included 30 patients with recent-onset rheumatoid arthritis fulfilling the new American College of Rheumatology/European League Against Rheumatism diagnostic criteria for rheumatoid arthritis and 20 healthy volunteers as controls. All were subjected to a complete blood count, erythrocyte sedimentation rate, C-reactive protein, liver function tests, renal function tests, rheumatoid factor, and plain x-rays of the hands and feet. Dual-energy x-ray absorptiometry DEXA was used to measure bone mineral density (BMD) of the left proximal femur, lumbar spine (L1–L4), and lower distal radius at the time of recruitment. Results In the RA patients, 13.3% had osteoporosis, 50% had osteopenia, and 36.7% had normal BMD. The most common site of osteoporosis was the lumbar spine (four patients, 13.3%) followed by the femur (two patients, 6.6%), and forearm (only one patient, 3.3%). There was a significantly higher percentage of osteoporosis among RA males than females and the difference was statistically significant ( P = 0.009). Osteoporosis was more common in patients treated with corticosteroids and disease modifying antirheumatic drugs (DMARDs) than in patients treated with only nonsteroidal anti-inflammatory drugs ( P = 0.004). Higher disease activity (DAS-28) was found in RA patients with osteoporosis compared to RA patients with normal BMD or osteopenia, but the difference was not statistically significant. Osteoporotic RA patients were found to have a higher SENS score for radiological damage than nonosteoporotic ones. Conclusion BMD changes do occur in patients with early RA, and are not necessarily correlated with disease activity (DAS-28). However, a significant negative correlation was found between BMD and the score of radiological damage (SENS). Dual energy x-ray absorptiometry is an important investigation to assess BMD in early RA patients

Ultra Wideband Channel Coefficient Measurements for Detecting Methane Gas in a Multipath Environment

In this paper, an investigation was carried out into the effect of a non-explosive methane gas mixture on various Ultra Wide Band Channel Coefficients. Using simplified apparatus consisting of a rubberized tube (6 mm diameter) connected for significant periods to either a (pressurized) source of mixed Methane and Nitrogen or alternatively to a Nitrogen only source. The tube containing either gas feed was wrapped using two complete turns around a 160mm diameter PVC pipe. Several flows of the mixed gas, containing 2.57% methane, were introduced and flowed through the pipe before being sealed in the tube. Removal of any Methane in the tube was achieved by flushing it with the pure Nitrogen source, initially and in-between samples of the mixed source. A Vector Network Analyser was connected using two identical directional antennas with the wrapped section of tubing placed between the two antennas and the wireless channel coefficients were measured over the Ultra Wide Band frequency span of 0.3GHz to 8GHz. Magnitude differences were taken between the baseline condition (tube flushed out with Nitrogen) and alternatively containing the methane mixture. It was found that consistent and repeatable experiments produced the same trend of differences over the same frequency span. This system based on this approach could thus be used as a simple sensor to detect the ac