Effect of electrolyte on synergism of anionic-nonionic surfactant mixture

In this study, anionic (Sodium Dodecyl Sulfate) and nonionic (Triton X l00) surfactants mixture (1:1 mass ratio) were evaluated for synergism in Critical Micelle Concentration (CMC) at different ionic strength values. Interaction between the binary surfactant mixture was studied by surface and interfacial tensions. The composition of mixed micelles and the interaction parameter, β evaluated from the CMC data obtained by both surface and interfacial tensions for different systems using Rubingh’ s theory were discussed. It has been shown, that the, micellization behavior of the mixture was improved significantly in presence of salt in particular after equilibration with shale

Wavelet Based Analysis for Transmission Line Fault Location

This paper presents wavelet based analysis for transmission line fault location. Faults in power transmission lines cause transients that travel at a speed close to the speed of light and propagate along the line as traveling waves (TWs). Traveling wave theory is utilized in capturing the travel time of the transients along the monitored lines between the fault point and the protective relay. This will help in proposing an accurate fault location technique based on high frequency components of fault current. Time resolution for these components is provided by the wavelet transform. This approach has the advantages of being independent of the fault impedance and fault inception angle. The application of the proposed technique for typical faults is illustrated using transient simulations obtained by MATLAB Simulink program. Keywords: travelling waves, wavelet transform, fault location, MATLAB Simulink

EFFECTS OF ENVIRONMENTAL DIESEL EXHAUST PARTICLES ON GASTRIC STEM CELLS

I would like to express my special thanks to the General Secretariat of the Executive Council of Abu Dhabi Emirate and Abu Dhabi National Oil Company (ADNOC) for their input and support. Last, but certainly not least, these acknowledgments would be incomplete without expressing my deepest appreciation to my family. Special acknowledgment of this achievement goes to my parents, who not only showed me unconditional love, acceptance, and respect for the person that I am throughout my life, they also showed me the strength of character which has brought me to where I am today. To my wife, for her love and the tremendous amount of support, which she gave me, both of which were vital ingredients in the completion of this study. To my lovely children, Mariam, Khaled, Maha, and Abdulla, for Even though stem cells have attracted many scientists because of their unique properties and therapeutic applications, it is not known how the environmental toxic factors could affect their features and functions. This study is focusing on the interaction between environmental diesel exhaust particles (DEP) and the stomach stem cells. In the stomach, the stem cells are responsible for generating and maintaining different types of cells which are organized to form numerous tubular glands. The aim of this study was to examine the effects of DEP on mouse gastric stem cells. The hypothesis is that DEP could have deleterious effects on the properties of mouse gastric stem cells such as their viability and migration. An immortalized mouse gastric stem cell line was used to develop a simple in vitro model to test the effects of exposure to various concentrations of DEP. Stem cells were cultured using routine tissue culture protocols. The DEP was added to the culture media at different concentrations: 1, 10, and 100 μg/ml for different timepoint up to 72 hours. Then, stem cells were analyzed using: cell viability assay, wound healing or migration assay, oxidative stress analysis by measurement of reduced glutathione, lipid peroxidation, and nitric oxide, expression analysis of genes specific for cell proliferation, cell death, and oxidative stress using quantitative real-time polymerase chain reaction, and expression of stem cell-specific proteins using western blotting. While DEP induced a reduction in the growth rate of gastric stem cells only at high concentration, no significant effects were found on cell migration, cell death-related genes/proteins. Only minor changes were observed in oxidative stress parameters. However, these findings were interestingly associated with the downregulation of Notch 1, 2, and 3 proteins. Since Notch signaling pathways play an important role in the development and differentiation of stem cells, it will be interesting to determine which mechanisms and target genes are involved in an animal model of DEP exposure. In conclusion, this study establishes an in vitro model system to investigate the biological feature of gastric stem cells when exposed to environmental pollutants. In addition, demonstrating the effects of DEP on adult stem cells will help in raising public awareness about environmental hazardous agents.r patience, understanding, and support. Without them, my DBA could have been an extremely lonely trip

Non-classical testosterone signaling is mediated by a G-protein-coupled receptor interacting with Gnα11

AbstractTestosterone is known to mediate its effects by two different mechanisms of action. In the so-called “classical” pathway testosterone binds to cytosolic androgen receptors (AR), which essentially function as ligand-activated transcription factors. Once activated, these receptors bind to DNA and activate the expression of target genes. In the “non-classical” pathway, the steroid hormone binds to receptors associated with the plasma membrane and induces signaling cascades mediated through activation of Erk1/2. The precise nature of the membrane-associated AR, however, remains controversial. Although some assume that the membrane and cytosolic AR are identical, others propose that the AR of the membrane is a G-protein-coupled receptor (GPCR). To evaluate these two possibilities we first searched for testosterone-induced signaling cascades in the spermatogenic cell line GC-2. Testosterone was found to cause phosphorylation (activation) of Erk1/2, CREB, and ATF-1, consistent with its non-classical mechanism of action. Silencing of AR expression by means of siRNA did not influence testosterone-induced activation of Erk1/2, CREB, or ATF-1, indicating that this pathway is not activated by the classical cytosolic/nuclear AR. In contrast, when the expression of the G-protein Gnα11 is suppressed, the activation of these signaling molecules is abolished, suggesting that these responses are elicited through a membrane-bound GPCR. The results presented here and the identification of the testosterone-specific GPCR in future investigations will help to reveal and characterize new testosterone-mediated mechanisms associated not only with fertility and reproduction but perhaps also with other physiological processes

Transient analysis of grid-connected wind-driven PMSG, DFIG and SCIG at fixed and variable speeds

This paper is aimed at presenting transient analysis of a grid-connected wind-driven permanent magnet synchronous generator (PMSG) at fixed and variable speeds by solving the system describing differential equations. For comparison purpose, wind-driven squirrel cage (SCIG) and doubly fed (DFIG) induction generators at fixed and variable speeds are studied using MATLAB/SIMULINK software package. Different from PMSG and DFIG the grid should feed the reactive losses of transmission lines and transformers at any value of short circuit ratio for SCIG. This increases the dynamic stability of DFIG and PMSG when compared with SCIG. Under three-phase-to-ground fault and single-phase-to-ground fault conditions, the time required to recover stability of PMSG wind farm is less than those  DFIG and SCIG wind farms for fixed and variable speeds indicating that PMSG is more stable than of DFIG and of SCIG wind farms

Assessment and Modelling of Wear prediction and Bit Performance for Roller Cone and PDC Bits in Deep Well Drilling

Drilling is one of the important aspects in the oil and gas industry due to the high demand for energy worldwide. Drilling time is considered as the major part of the operations time where the penetration rate (ROP) remains as the main factor for reducing the time. Maximizing ROP to lower the drilling cost is the main aim of operators. However, high ROP if not controlled may impact on the well geometry in terms of wellbore instability, cavities, and hole diameter restrictions. Accordingly, more time is needed for the other operations that follow such as: pool out of hole (POOH), casing running, and cementing. Bit wear is considered as the essential issue that influences in direct way on the bit performance and reduce ROP. Predicting the abrasive bit wear is required to estimate the right time when to POOH to prevent any costly job to fish any junk out to the surface. The two-common types of bits are considered in the research, rock bits (roller cone bits) and Polycrystalline Diamond Compact bits (PDC). This study focuses more on PDC bits because about 60% of the total footage drilled in wells worldwide were drilled by PDC bits and this is expected to reach 80% in 2020. The contribution of this research is to help reducing the drilling cost by developing new tools not to estimating the time when to POOH to surface but also to measure the wear and enhance the accuracy of prediction the bit efficiency. The work is broken down into four main stages or models to achieve the objective: The first stage; estimating of the rock abrasiveness and calculate the dynamic dulling rate of the rock bit while drilling. The second stage; estimating the PDC abrasive cutters wear by driving a new model to determine the mechanical specific energy (MSE), torque, and depth of cut (DOC) as a function of effective blades (EB). The accuracy of the predicted wear achieves 88% compared to the actual dull grading as an average for bits used in five wells. The third stage; modifying the previous MSE tool to develop a more accurate approach; effective mechanical specific energy (EMSE), to predict the PDC bit efficiency in both the inner and outer cone to match the standard bit dulling. The fourth stage; predicting ROP while PDC drilling in hole by accounting three parts of the process: rock drillability, hole cleaning, and cutters wear. The results achieve an enhancement of about 40% as compared to the available previous models. Consequently, the developed models in this study provide a novelty on understanding in more details the bit rock interface process and gain an idea of the relationship between the drilling parameters to enhance the bit performance and avoid damaging the bit. This is basically about optimisation the controllable factors such as: weight on bit (WOB), rotary speed (RPM), and flow rate. The result is the reduction in time losses and the operations cost. To ensure reliability and consistency of the proposed models, they were validated with several vertical oil wells drilled in Libya. The results from the validation of the models are consistent with the real field data. The research concludes that the developed models are reliable and applicable tool for both: to assist decision-makers to know when to pull the bit out to surface, and also to estimate the bit performance and wear

Intermediate Role of the Criterion of Focus on the Students Benefiting in the Relationship between Adopting the Criterion of Partnership and Resources and Achieving Community Satisfaction in the Palestinian Universities

The study aimed at identifying the intermediate role of the criterion of emphasis on students and beneficiaries in the relationship between adopting the criterion of partnership and resources and achieving the satisfaction of the society. The study used the analytical descriptive method. The study was conducted on university leadership in Al-Azhar, Islamic and Al-Aqsa Universities. The sample of the study consisted of (200) individuals, 182 of whom responded, and the questionnaire was used in collecting the data. The study reached a number of results, the most important of which were: The level of adoption by the Palestinian universities of the criterion of partnership and resources came to a large extent. The level of adoption by the Palestinian universities of the criterion of emphasis on the beneficiary students was very high. The criterion of partnership and resources to achieve the satisfaction of the community surrounding the Palestinian universities, the existence of a statistically significant impact of the adoption of the criterion of partnership and resources to strengthen the focus on students benefiting in Palestinian universities, The focus on the students benefiting from the satisfaction of the community surrounding the Palestinian universities, the existence of a statistically significant impact on the adoption of the criterion of partnership and resources to achieve the satisfaction of the community surrounding the Palestinian universities, The study presented a number of recommendations, most important of which are: Increase interest in the resource and partnership criterion through enhancing the university's resources and developing internal and external partnerships to serve the university and the society. Increase the focus on students and beneficiaries by providing an appropriate educational environment and academic programs that meet the needs of the labor market. Through the strengthening of existing community service centers and the establishment of new community centers, strengthening the partnership of industrial companies and promoting scientific research for the benefit of universities and society