bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is folic acid supplementation to food benefit or risk for human health?
Authors: Bjelakovic Gordana , Stojanovic Ivana , Jevtovic-Stoimenov Tatjana , Bjelakovic Ljiljana , Kamenov Borisav , Pavlovic Dusica , Kocic Gordana , Sokolovic Dusan , Basic Jelena , Bjelakovic Goran B. 
Published: October 2013

Abstract
The need for sufficient quantities of folic acid for normal embryogenesis and fetal development is well known. Women of childbearing age must be sure to have an adequate intake of folic acid periconceptionally prior to and during pregnancy. Folate plays an essential role in the biosynthesis of RNA and DNA, phospholipid and neurostransmitters synthesis, using S-adenosylmethionine (SAM) as the primary methyl group donor. In some countries, the knowledge that folic acid is preventable for the reduction of the risk for neural tube defects (NTD) and in lowering the high amount of homocysteine (Hcy) led to the recommendation that all women capable of becoming pregnant should consume 400 µg of folic acid daily. Later, in 1998, folic acid fortification of all enriched cereal grain product flour was implemented in some countries. In addition to careful monitoring of adverse effects, the studies are warranted in order to determine the potentially positive and deleterious effects of folic acid fortification and supplementation on the human health or human diseases. To further understand the metabolic action of folates we asked ourselves the question: Is the intake of a sufficient amount of this vitamin a benefit or risk for human health?
Impact on Thin Film Silicon Properties and Solar Cell Parameters of Texture Generated by LaserAnnealing and Chemical Etching of ZnO:Al
Authors: Boukhicha Rym , Johnson Erik , Daineka D. , Michel Antoine , Lerat J.F. , Emeraud Thierry , Roca i Cabarrocas Pere 
Published: October 2013

ABSTRACTThe use of a laser annealing and chemical texturing process (dubbed the LaText process) on room-temperature sputtered ZnO:Al has been shown to generate unusually high haze properties, favorable for thin film silicon solar cells.This is due to the melting of the ZnO:Al layer by the XeCl laser, and the formation of crystalline domains onthe surface, for which the grains and grain boundaries are subsequently etched at different rates. The unusual surface morphology produced through this process can strongly impact the nature of the amorphous or microcrystalline silicon material deposited thereupon. In this paper, we report on results for amorphous silicon devices, for which the surface texture is seen to slightly impact thelight absorption in the material, but more interestingly, also the light-induced degradation of the cells.For co-deposited cells, devices deposited on surfaces with the characteristic "LaText" morphologyundergo a much lesser degradation. Furthermore, the decreased degree of degradation coincides with a notable shift in the Raman scattering peak. This provides a rapid diagnostic for testing multiple textures and deposition parameters.
Nano-Hydroxyapatite Coated Femoral Stem Implant by Electrophoretic Deposition
Authors: Zhang Heng , Krajewski Jay , Zhang Zongtao , Masopust Mark , Xiao Danny T. 
Published: October 2013

ABSTRACTA nanostructural hydroxyapatite (HA) coating was deposited to a porous Ti6Al4V femoral stem implant using electrophoretic deposition (EPD) to improve the bond strength, healing speed, and durable service life. The nanostructure of HA and micro-pores created in the coating can enhance the bioactivity and increase the adhesion between the implant and hard tissue. In order to achieve homogenous HA coating on the stem implant with a porous surface profile, a compensation electrode was designed and prepared. Rotation of the implant was conducted during the coating process so that a uniform coating could be achieved. The EPD combined with a dip coating was used to compensate for the complex profile and led to a homogenous coating throughout both peak and valley areas.This developed coating process is able to deposit homogeneous HA coating on a complicated implant surface. Compared to the coating made by plasma thermal spray, the EPD HA coating can cover inner cores and exhibit a better adhesion and bioactivity. The EPD HA coating possesses significantly improved corrosion resistance compared to thermal spray HA coating. Most importantly, the biomechanical property was significantly promoted based on an in vivo animal test.
Polyvictimization and Risk for Suicidal Phenomena in a Community Sample of Spanish Adolescents
Authors: Soler Laia , Segura Anna , Kirchner Teresa , Forns Maria 
Published: October 2013

This study aims to provide data regarding the association between reported degree of victimization and suicidal phenomena, with special emphasis on gender differences. There were 923 adolescents recruited from eight secondary schools in Catalonia, Spain. The Youth Self-Report (YSR) and the Juvenile Victimization Questionnaire (JVQ) were used to assess suicidal phenomena and victimization, respectively.Participants were divided into three groups (nonvictim, victim, and polyvictim groups) according to the total number of different kinds of victimization reported. Results showed that the polyvictim group reported significantly more suicidal phenomena than did the victim and nonvictim groups in both boys and girls. Furthermore, although no gender differences in reported suicidal phenomena were found in the nonvictim group, girls reported significantly more suicidal phenomena in both the victim and the polyvictim groups.In conclusion, the results suggest that victimization may play an important role in generating gender differences with respect to reported suicidal phenomena. In addition, this study highlights the importance of taking into account the whole range of victimizations suffered by adolescents when seeking to design suicide prevention and intervention policies.
Field Tests Quantify Processes Utilizing an Enhanced Downhole Dynamics Measurement Tool for Vibration Mitigation and Performance Optimization
Authors: Veeningen Daan , Hewlett Richard , Salazar Joe , Coit Andrew , Furniss Eric 
Published: October 2013

Abstract
Today's drilling optimization process depends greatly upon post-well analysis of recorded downhole drilling dynamics. Sophisticated downhole sensors are limited by wireless telemetry systems that offer a relatively limited bandwidth with considerable latency. Real-time knowledge of subsurface conditions could improve drilling processes and allow the automated, closed-loop control of surface parameters based on high-frequency downhole data.
This paper describes the development and field deployment of a new, high-frequency downhole measurement tool. This tool transmits multi-sensor data in real time through a wired drillstring telemetry system, virtually eliminating latency. This enhanced dynamics tool, which acquires downhole measurements at 800Hz, includes tri-axial vibration, RPM, downhole weight on bit, and downhole torque, as well as annular pressure and temperature.
This data is instantaneously streamed to the surface and available at 80Hz for processing by surface acquisition systems. An advanced auto-driller controls the applied surface weight on bit based on the downhole dynamic measurements. Essentially, high-frequency downhole parameters become independent setpoints, supplementing information to the once-independent surface setpoints.
This paper provides details regarding a two-month field test of 6¾" dynamics tools in six wells to quantify the operational impact of the new technologies and operating processes covering vertical and directional 12½", 8¾" and 8½" hole sections. Comparison is offered for drilling both with air and with fluids, as well as drilling with positive displacement motors and with rotary steerable systems.
The field test included establishing a benchmark in the first well, followed by utilizing multi-axis vibration measurements over the course of the subsequent five wells to actively mitigate the shocks and vibrations. Operational performance was further optimized in the subsequent runs incorporating automated control of downhole weight.
Offshore Rig Integrated System and Software Requirements Verification and Validation
Authors: Haas David 
Published: October 2013

Abstract
Offshore drilling rigs are increasingly complex integrated systems that incorporate automated software-dependent control systems to maintain safe and effective operations. Under even relatively benign conditions, software issues have caused unintended circumstances, sometimes with catastrophic results. Catastrophic incidents and unplanned downtime are reduced when such systems are based on well-defined requirements that are verified during system development and then validated to work as intended in the operational environments.
Industry leaders, governments and international organizations are encouraging more stringent practices to improve offshore drilling operational safety. DNV and ABS standards, Integrated Software-Dependent System (ISDS) and Integrated Software Quality Management (ISQM), respectfully, aim to reduce the number of system and software issues through the application of standard software verification and validation (V&V) practices.
The aerospace industry has a long tradition for applying such discipline. In fact, it is required when working with some government agencies, such as the NASA and the Federal Aviation Administration. These disciplines contribute to the design of complex, safe, reliable, high-performance systems that allow humans and equipment to operate in the most extreme environments on Earth and in space. Over the past 12 years, operators in the offshore drilling industry have benefited significantly through application of aerospace-based systems engineering disciplines to address a wide variety of high-value rig system safety and performance issues. These processes are most effective when included during development of new rig and subsystem designs. However, significant benefit to system safety and performance can also be achieved when these processes are incorporated as part of service life extension and subsystem upgrade projects.
This paper will focus on a description of the processes and benefits to come from applying an integrated system level software requirements verification and validation approach.
How Images Can Steer a Well
Authors: Bazara Magdi , Abdulwahid Dia , Al-Sharafi Mohamed , Al Maashari Badar , Al-Kindi Zainab , Al-Shabibi Issa 
Published: October 2013

Abstract
Petroleum Development Oman (PDO) is considered as one of the biggest companies that work in Oil and Gas exploration and production in the Sultanate of Oman. PDO produces more than 80% of the country's crude-oil production and nearly all of its natural-gas supply. PDO Exploration takes care of the new oil fields and most of the wells become more challenging.
Well#A located in "X" field planned horizontal parallel to the top of Shuaiba reservoir. The well has many challenges such as it's an exploration well and the area contains a lot of uncertainties in structure and facies, more than one fault expected towards the well toe and the target depth & thickness uncertainties are a usual challenge. There was a real need to utilize latest logging while drilling "LWD" technologies to achieve the well objectives. Some of LWD technologies needed were "Distance To Boundary" measurements to place the well in the desired and optimum location and high quality images while drilling to minimize wire line operations risk and understand formation fracturing system.
The well successfully achieved the objectives with no sidetracks for the lateral section and a very high images quality been recorded while drilling resulted in a successful understanding for the well formation fracturing system.
Fifteen Years of Successful Coiled Tubing Re-entry Drilling Projects in the Middle East: Driving Efficiency and Economics in Maturing Gas Fields
Authors: Krueger Stefan , Gray Keith , Killip David 
Published: October 2013

Abstract
During the last 15 years, coiled tubing drilling (CTD) projects in the Middle East (ME) have proven an efficient and economic means of increasing and sustaining production for the oil and gas industry. CTD was implemented in 1998 and since then established as a standard, viable solution for the existing re-entry challenges in various maturing fields and applications. During this time frame corresponding technologies and procedures have been developed and continuously improved to address existing and new challenges in this growing market segment.
This paper describes the use of CTD from the first activity in Oman through operations in the Kingdom of Saudi Arabia, utilizing project data collected during 15 years of operational experience. The paper includes the technology and procedural changes that addressed new and special challenges observed within the aforementioned projects and drove production from these maturing fields such as: The coverage of low- and high-pressure reservoirs in various fields with high temperature and high H2S challenges.The movement from single re-entry wells to multilateral wellbore designs, alongside the envelope extension from pure directional wellbore placement according to plan, to real-time reservoir navigation by geo- and bio-steering processes.The introduction of special applications such as ERD and precise kick off from vertical wells with coiled tubing (CT) technology.The extension of drilling operations from overbalanced to fully underbalanced (UB) operation, with maximum N2 injection through the CT string and the requirement to deal with production while drilling.Development of other equipment to enable the pressure deployment of the BHA, allowing a move away from conventional tower set-ups to a dedicated highly mobile coil tubing rig.
The projects resulted in constant technology improvement and implementation of new developments in all aspects of CTD technology. To achieve the necessary efficiency and economic goals for the re-entry projects, new technology must include downhole bottom hole assembly (BHA) technology, casing exit equipment, surface equipment of the overall rig and other associated equipment such as the underbalanced drilling (UBD) package. Similar to the utilized technology, the corresponding procedures were also optimized and new ones introduced to adapt to changing environments and challenges.
Based on the previous and current achievements of CTD in the Middle East, this trend of adjusted developments and continuous improvements will continue to further drive project efficiencies and economics.
Extended Aramco Method- Its technico-Economic Significance in Non-damaging Drill-in Fluid Design
Authors: Amanullah Md , Allen Tim 
Published: October 2013

Abstract
Various sized bridging materials (SBMs) such as ultra-fine, fine, medium and coarse grade SBMs are frequently used in drill-in fluid formulations to improve drilling fluid properties, enhance mudcake quality and reduce near wellbore formation damage. The mechanical properties, especially the material toughness of the SBMs play an important role in fulfilling these functional tasks. Weak and easily disintegrating SBMs are unable to maintain the functional capability of drill-in fluid due to a major change in the planned particle size distribution in the fluid. Hence, drill-in fluid containing rapidly degrading SBMs shows poor performance while drilling. This highlights the need for selection of very tough and high strength SBMs to design superior drill-in fluid for non-damaging drilling operation in the pay zone. However, the industry lacks a suitable method for screening, testing, evaluation, quality control and quality assurance of SBM products to select the best and reject the worst and the inferior. Hence, there is a need of development of a quick and reliable SBMs characterization method to use as a guiding tool for designing superior and high performance drill-in fluid for non-damaging drilling operation.
Historically, color, provenience, origin, degree of diagenesis and metamorphism of the SBM samples or acid solubility were evaluated to use as a guiding tool to select highly durable and mechanically strong SBM products. These subjective and inappropriate methods of assessment frequently lead to disastrous SBMs performance. Due to the limitation and ambiguity of the petrographic and acid solubility methods, attempt was made to identify high quality SBMs by using Brinnel Hardness Tester. The outcome of the research was inconclusive and provided no guiding tool for SBMs performance evaluation. Failure of the above approaches lead to the development of the Aramco method for characterization, quality control and quality assurance of SBMs. Though the method is good for coarse and medium grades SBMs, it has some limitations for fines and ultra-fine SBMs. To overcome the limitations of the Aramco method, it was extended by introducing a dedicated software driven laser particle size analyzer that can measure the PSD of all grades of SBMs quickly and accurately.
This paper describes the Extended Aramco Method and its application in various SBMs evaluations to select the superior and reject the inferior for high performance drill-in fluid design. Experimental results demonstrate the universal application of the Extended Aramco Method and its usefulness in SBM performance evaluation for superior fluid formulations and non-damaging drilling operations.
"FARIIQ WAHAD" A Drilling Divisions Evolution into a Learning Organization by Engaging Mature Hires & Young National Professionals
Authors: Lichtenecker E. L. , Humoodi A. N. , Kuyken C. W. , Salem A. A. , Al-Menali A. M. , Al-Braiki A. M. 
Published: October 2013

Abstract
The growing Exploration & Production (E &P) industry has an increased requirement for experienced and qualified Drilling Engineers and Supervisors. The Abu Dhabi Company for Onshore Oil Operations (ADCO) has the additional difficulty that the United Arab Emirates (UAE), due to its small population, is even today dependent on expat staff and the general interest of young Emiratis in technical jobs in the oil and gas industry has been marginal.
Traditionally, ADCO has either hired a) international, mature, and experienced drilling engineers and supervisors and allocated them to various teams, putting them straight to work or b) young graduates, who were sent through the Competence Assurance Management System (CAMS) program (2 – 3 years). The quality of the work delivered usually depended on the onsite training and guidance their bosses provided them. However, ADCO is aggressively expanding and doubling its rig fleet from 23 to 46 land rigs in the next 3 years to achieve the oil production increase from 1.4 to 1.8 m bpd, which results in increased substantial staff requirement.
This paper will present ADCOs Drilling Division strategy of introducing a combination of in-house development and external certifications to attract more UAE nationals, integrate the new international staff, and cater to the specific needs of their new recruits and their respective job profiles. The role of the three in-house training modules (the CAMS Real Work Learning Academy for graduates, the Drilling Newcomers Academy for mature hires, and the TA Academy for technical assistants) as well as the as external certifications (SPE certification, Shell Round 1 &2 exam, Chartered Engineer, and MSc for Drilling Engineering and Design) is to ensure a constant career development of drilling engineers, drilling supervisors, and specialists, as well as specifically supporting Emirati nationals to gain an internationally recognized first class reputation.
As the lecturers and trainers are sourced in-house the graduates and mature hires are immediately introduced to most of their future leaders and colleagues in a proactive and hands-on environment allowing them to also share their own experiences and become regardless of their level of experience or origin: "FARIIQ WAHAD – One Team".
Perforating for Squeeze Through Four Casing Strings to Remediate Annulus Gas Leak Problem
Authors: Ibrahim Mohamed El-Sayed , Al-Neaimi Ahmed Khalifa , Hassane Mohamed Abdelsalam , Al-Mansoori Abdul Salam , Mohamed Shanof , Al-Mutwali Omar , Salsman Alan 
Published: October 2013

Abstract
ADMA-OPCO had integrity problems in a gas well and abandonment was the only option available to restore the integrity of the offshore multiwell jacket and revive the adjacent wells that had been shut in due to the problems. The integrity problems were oil/gas bubbles observed on the seabed around the conductor pipe and high sustained pressures in the outer cemented casing annuli. The entire jacket was considered very dangerous under these conditions.
Because the leak was determined to be located outside the 18 5/8-in. casing, perforating several intervals was required to improve the chance of a successful squeeze. Some of the intervals were perforated through 3 casing strings and the rest through 4 strings of casing; 7-in., 9 5/8-in., 13 3/8-in. and 18 5/8-in., before being squeeze cemented to cure the problem.
Modeling of the perforating gun performance indicated that penetration through the four casings could be achieved. The modeling was confirmed with laboratory testing in a mock setup to simulate worst case conditions downhole. The laboratory test results were very useful in the final gun selection process. Once the gun and deep penetrating charge type were chosen a local modification was performed to create an 18° phased gun system ideally suited to remedial applications. An optimal cement type was also chosen to be used for this application.
The perforating/squeeze jobs were executed and surface rate and pressure measurements have confirmed that the jobs were successful.
This paper will present the job preparation considerations, the prejob testing of the perforating systems, the local modification used to create the 18° phasing, the cement used for the squeeze and the confirmation that the job was successful. It is believed that this is the first time such an operation has been successfully executed and the results should be of interest to all operating companies.
Passive Inflow Control Device Autonomy - How much is too much?
Authors: Abdelfattah T. A. , Garcia G. A. , Banerjee S. 
Published: October 2013

Abstract
The production life of a typical well may be split into three stages. The first stage is the start-up stage, which includes flowing back completion fluid that was initially in the well. This is followed by the production of the targeted reservoir fluid and finally the last stage, which can include production of unwanted fluids such as gas or water from the reservoir.
Passive Inflow Control Devices (PICDs) have been proven to be an effective solution for controlling influx to a well in the early stages of production life. However, breakthrough of unwanted fluid is inevitable. It is at this stage that PICDs should provide a larger level of restriction at the zones in which breakthrough occurs. The level of restriction is a function of the influx rate and more importantly, the fluid properties. For fluids flowing at a higher velocity and lower viscosity, the PICDs will behave in a manner that will passively result in a larger pressure drop. In the PICD world, this phenomenon is referred to as the "Autonomous" effect.
The question remains, what level of autonomy is optimum so as not to restrict the targeted hydrocarbon production that could stem from flowing through breakthrough zones? A water cresting scenario has been simulated as a base case to demonstrate the proper level of autonomy required of a PICD. Several hypothetical PICD designs and a field proven hybrid design, with varying levels of autonomy, are demonstrated.
Simulations have been carried out for each design to assess the performance in terms of oil sweep and cumulative production. Results have shown that there is an optimum level of autonomy required before the effect becomes detrimental to the cumulative target production.