bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Alkali-Silica Reaction ASR on Structural Integrity of Light-Weight Wellbore Cement
Authors: Albers Dylan 
Published: October 2017

Abstract
Wellbores drilled through low-pressure formations encountered offshore or in depleted formations, require use of light-weight cement slurries (less than 13 pounds per gallon (ppg)). These densities in cements can be achieved through foaming, increasing the water content, or using silica-based microspheres. Water-extended cements have a threshold down to weights of approximately 13 ppg and to achieve densities lower than this require the use of foaming and/or silica based microspheres. Each of these methods has limitations that can severely impact hydraulic properties of cement. The foamed cements have the potential to become unstable at high pressures, while silica-based microspheres have chemical instability in the high alkalinity environment of wellbore.
This chemical instability of silica-based microspheres used in cements, creates a hydrophilic gel that is expansive and creates fractures within cement matrix as it expands. This is more formally referred to as alkali-silica reactivity (ASR). Prevention of ASR involves the application of additives to the cement that act as a sink for the alkalinity during hydration for long-term prevention of the ASR. Lithium nitrate is one of these prevention methods that is theorized to allow for other beneficial reactions.
This study investigates the effects of a highly alkaline cement pore-water on the chemical stability of microspheres. Microstructural characterization involves identification of reaction products in alkali- reacted glass beads within 28 days hydrated wellbore cement at wellbore temperatures, as well as the impact of lithium nitrate as a prevention method. The scanning electron microscopy of polished and fractured surfaces reveal two different reaction processes, with the ASR clearly absent in the slurry containing lithium nitrate. The micro-mechanical properties of these changes were also tested using microindentation tool. Lastly, porosity values were tested using helium gas Porosimetry. Lithium nitrate shows an effect on mechanical properties but not on porosity values as compared to cements solely containing microspheres.
Formation Fluid Sampling Technique Allowing to Control Physical Properties of Sampling Medium
Authors: Gutman Roman 
Published: October 2017

Abstract
The present paper addresses the general methods of formation fluids properties determination. Physical properties of formation fluids play a major role in processes of oil and gas deposits calculations and for aspects estimation of hydrocarbon fields development and exploitation. That is required to optimize wells operations, and to perform technological operations on enhance of oil recovery, etc.
Since the volume of samples for physical properties determination is limited, it is necessary that samples completely confirm the formation hydrocarbons. Therefore the most important question here is sampling of clean and representative samples. To solve this problem a technique of formation fluid sampling with use of the bottomhole equipment featuring presence of an additional section with density and viscosity gauge mounted between sampling chamber and inlet valve unit has been proposed.
This way of sampling will ensure receiving density and viscosity parameters of liquids immediately during sampling. That will allow monitoring the type of sampled medium and will increase the probability to receive representative samples by these parameters determination.
A New Approach for Predicting Drillstring Vibration Impact on Wellbore Stability
Authors: Khaled Mohamed Shafik 
Published: October 2017

Abstract
Many studies attributed wellbore instability problems to physical and chemical interactions between rocks and drilling fluids; however the impact of drillstring vibration was neglected. This study aims to investigate the effect of drillstring vibration on wellbore stability; and determine major factors lead to drillstring collision with wellbore.
Drillstring vibration mechanisms are reviewed from literature to identify type of drillstring vibration responsible for wellbore failure. Then, drillstring equations of motion are solved utilizing Runga-Kutta numerical scheme; and sensitivity analysis is done to assess the effect of each variable (inputs) on drillstring radial displacement. Moreover, new model is developed to predict critical ranges of drillstring vibration that collapse wellbore. Model bases on rock mechanics principles, whirl vibration mechanism and Newton second law.
Results show a direct relation between whirl vibration initiation and wellbore instability; however axial and torsional vibrations have negligible effect. Wellbore failures resulted from drillstring vibration are more likely to happen in small hole sizes (6 in) than bigger holes. Drill collar length and drillstring revolutions per minutes are the primary factors aggravate drillstring collision with wellbore, while wellbore inclination and mud weight have minor impact. When drillstring vibrates and hits wellbore wall, hole collapse happens due rock compressive failure, rock fatigue, and reduction in rock strength. The innovated model estimates values of drillstring accelerations that collapse wellbore, and predicts optimum mud weight needed for safe drilling before and after reduction in rock strength due to drillstring vibration.
Research findings reduce risks of wellbore collapse and drillstring failure resulted from drillstring vibration by: presenting recommendations in drillstring design and drilling optimization; and utilizing model outputs to compute critical limits of drillstring vibration and optimum mud weight to prevent drillstring collision with wellbore.
Application of Pressure Transient Concepts for Improved Upscaling of Geologic Models
Authors: Nunna Krishna 
Published: October 2017

Abstract
Upscaling in the context of reservoir modeling is the process of averaging the reservoir properties to obtain coarse dynamic simulation models from high resolution static geologic models. The objective of upscaling is to preserve the maximum amount of heterogeneity with the minimum possible cost of simulation. However, the existing flow based upscaling methods rely on Steady State (SS) concepts of flow which cannot preserve the dynamic connectivity from the fine to coarse scale. This can result in overly homogenized simulation models which systematically yield optimistic results. The objective of this work is to develop an upscaling technique which preserves the dynamic connectivity from the geologic models to simulation models. Application of pressure transient concepts enables us to distinguish between well-connected pay and weakly connected payin the region of upscaling.This allows us to quantify the sub-volume of the resource that is not effectively producible. In terms of monetary value, the approach allows fundamental control on well planning. Over simplified simulation models systematically overestimate sweep, leading to a lower well count in the planning stage. By preserving the dynamic connectivity, the proposed approach helps in preparing a more accurate economic model for field development through proper well planning.Also, capturing the fine scale heterogeneity is important for any forward prediction of complex flow patterns in the reservoir.
The concepts of diffusive time of flight and drainage volume were utilized to accurately capture the local pressure transients. Also, a new volume averaging approach was developed to obtain the effective coarse transmissibility that accounts for non-uniform fluxes and pressure gradients while averaging.The proposed method was validated on SPE10 synthetic model and an onshore tight gas reservoir. The comparison of performance prediction against fine scale numerical simulation and Steady State incompressible upscaling demonstrate the accuracy of the proposed approach.
Bottomhole Assembly Smart Generator
Authors: Shabara Khaled 
Published: October 2017

Abstract
Many studies investigated drillstring vibration as harmful forces cause drillstring failure. However, these huge forces can be converted into useful energy. This paper aims to conserve drillstring vibration forces into electrical energy depending on piezoelectric material.
Drillstring vibration mechanisms are reviewed to study the modes of vibration and recognize mechanical stresses values acting on the drillstring through each level. Then, piezoelectric materials researches on small scale power generation are studied to select proper material with good electrical and mechanical properties to design generator with sufficient capacity. A model was conducted to prove that Lead Zirconate Titanate generator (PZT) has a good mechanical performance against the subjected forces. This model was developed to sense the force acting on well walls depending on the generated voltage at the radial direction. Finally a computer software was designed to connect the generator and sensor outputs with the well logs while drilling. The software design depends on comparing the values of applied forces on the drillstring and well walls with the maximum allowable strength of drillstring.
Results show that vibration levels (mechanical energy) can be converted into electrical energy through piezoelectric generator. This electrical energy is sufficient to provide continuous power to the downhole tools. Obtained readings from the developed model can prevent the drillstring failure. The new software outputs show if the applied forces maintain safe operation on drillstring and well walls which will prevent drillstring failure or well collapse. This will guarantee maximum operating time with less non-productive time.
The most significant part in this paper is that it changes the concept of the drillstring vibration as a harmful energy to useful source of energy can be added to downhole tools; this will reduce tripping out time to replace downhole tools batteries. The values of the generated electrical energy are remarkable as it is one of very limited number of applications using piezoelectric technology in such large scale.
Use of an Iterative Ensemble Smoother Methodology in a History Matching and Uncertainties Assessment Process
Authors: Vasconcellos Soares Ricardo 
Published: October 2017

Abstract
The goal of this work was to apply an ensemble-based technique for data assimilation (Ensemble Smoother with Multiple Data Assimilation, ES-MDA) to link probabilistic history match and uncertainties assessment of a petroleum benchmark field. The first step was the definition of the model uncertainties and its parameterization to stablish the prior ensemble composed by 500 models. After this stage, I applied standard ES-MDA followed by the localization technique which was considered taking into account the area of influence of each well. Then, I conducted production forecast to assess field behavior until the end of the field productive life and compared with the reference response. To evaluate the results, I used two mais indicators: the Normalized Quadratic Deviation with Signal (NQDS) and the Sum of Normalized Variance (SNV). I used NQDS to verify which models were within the specified tolerance while SNV was responsible for evaluating the loss of variability of the ensemble. Through the standard ES-MDA, it was possible to improve knowledge about the reservoir behavior and obtain good data matches with low computation effort. However, I observed certain loss of variability and spurious correlation in the models. Afterwards, I applied ES-MDA with localization to improve results and this approach helped to increase variability of the ensemble and generate smoother images. It was crucial to compare the production forecast with the reference response to validate the methodology. The main advantage of this work is the ability of analyzing the reduction of uncertainties aligned with the benchmark case with a known response, assessing how strong the loss of variability of the ensemble was and comparing the convergence of the forecast with the reference response. Furthermore, this technique required a low computation effort when compared with other similar methods.
Medium-to-low-speed freight rail transport induced environmental vibration and analysis of the vibration isolation effect of building slope protection piles
Authors: Sun Chenglong , Gao Liang 
Published: October 2017

The environmental vibration induced by freight rail transport has become an important type of environmental pollution. The environmental vibration caused by a running freight train near a typical medium- to low- speed railway in China and in the surrounding residential area is measured and analyzed. The test result shows that in the region adjacent to the railway, the weighed vibration acceleration level as a function of time (t) in the vertical direction (VLz) is lower than 80 dB, which meets the requirements of the standard (GB10070-88); however, in the surrounding residential area, the VLz is in the range of 58-74 dB, which is 0-4 dB higher than the specified limit during the day and 0-2 dB higher than the specified limit at night. For the isolation of environmental vibration induced by the freight train, a dynamic model of the vehicle and track and a finite element model of the railway, stratum and building are constructed to analyze the feasibility of modifying the slope protection piles outside of the building to make them function as vibration isolating piles, and the vibration isolation effects of such piles in a single row and double rows are compared with the case without piles. The simulation result shows that vibration isolation piles can attenuate the vibration level in front of and behind the piles: compared with the case without piles, the VLz can be reduced by 2-4 dB within 5 m behind the piles in a single row, and can be reduced by 4-10dB behind the piles in double rows, so the double-row setup is recommended for vibration isolation. It is suggested that for residential buildings which are close to the existing medium- to low- speed freight railway lines and for which other vibration attenuation measures are impractical, satisfactory vibration isolation effects may be achieved by simply increasing the number of rows of slope protection piles.
Pyrrolyl Pyrazoline Carbaldehydes as Enoyl-ACP Reductase Inhibitors: Design, Synthesis and Antitubercular Activity
Authors: Dixit Sheshagiri R. , Joshi Shrinivas D. , Kulkarni Venkatarao H. , Jalalpure Sunil S. , Kumbar Vijay M. , Mudaraddi Tulasigiriyappa Y. , Nadagouda Mallikarjuna N. , Aminabhavi Tejraj M. 
Published: October 2017

Introduction:In efforts to develop new antitubercular (anti-TB) compounds, herein we describe cytotoxic evaluation of 15 newly synthesized pyrrolyl pyrazoline carbaldehydes.Method & Materials:Surflex-Docking method was used to study binding modes of the compounds at the active site of the enzyme enoyl ACP reductase fromMycobacterium tuberculosis (M. tuberculosis), which plays an important role in FAS-II biosynthetic pathway ofM. tuberculosisand also it is an important target for designing novel anti-TB agents.Results:Among the synthesized compounds, compounds4gand4ishowed H-bonding interactions with MET98, TYR158 and co-factor NAD+, all of which fitted well within the binding pocket of InhA. Also, these compounds have shown the same type of interaction as that of 4TZK ligand. The compounds were further evaluated for preliminary anti-TB activities againstM. tuberculosisH37Rv strain.Conclusion:Some compounds were also screened for their mammalian cell toxicity using human lung cancer cell-line (A549) that was found to be nontoxic.
Lumbar Spinal Angiolipoma with Expanding Left Neural Foramen Mimicking Lumbar Schwannoma; Case Report and Review of The Literature
Authors: Akyuva Yener , Gonultas Aylin , Karaaslan Numan , Gulciftci Dagci Zehra , Saglik Semih , Isyar Mehmet , Mahirogullari Mahir 
Published: October 2017

Aim:
To describe a patient with lumbar angiolipoma mimicking schwannoma in the posterolateral side of the spinal canal with expansion of the left lumbar foramen and to discuss the clinical, radiologic, and surgical features of these lesions with literature.

Methods:
Without language restriction in this paper, the electronic databases; The Cochrane Collaboration the Cochrane, The Cochrane Library (Issue 2 of 12, Feb. 2011), ProQuest, US National Library of Medicine, National Institutes of Health (NLM) and PubMed dating from 1966 September to January Week 2 2017, were searched for comparative experimental studies using the terms: “OR”, “AND”. On-line literature searches were conducted using the key words “lumbar angiolipoma”, “schwannoma “, “spinal angiolipoma”, “spinal cord”, and “spinal canal”. We compared this research with our patient.

Results:
Bilateral L2 total laminectomy, excision of the tumors and bilateral L2-L3 transpedicular stabilization were performed, and complaints improved prominently. Pathological examination was reported as angiolipoma.

Conclusion:
The research shows that a probable diagnosis in such tumor cases could be made by sufficient pre-op scanning before surgical operations and although angiolipoma has been rarely seen in lumbar posterolateral space, it can be seen in lumbar region and mimic schwannoma as producing symptoms and signs of spinal cord and nerve root compression.
Correlation Between Stress and Quality of Life Experienced by Caregivers: Perception of a Group of Healthcare Professionals
Authors: Silva Bhárbara Karolline Rodrigues , Quaresma Fernando Rodrigues Peixoto , Maciel Erika da Silva , Figueiredo Francisco Winter dos Santos , Sarraf Jonathan Souza , Adami Fernando 
Published: October 2017

Aim:This study aims to evaluate the relationship between perceived level of stress and quality of life of professionals working in Prompt Service Units in the city of Palmas, Tocantins.Methods:A cross-sectional study was performed among 164 professionals from Prompt Service Units. Stress levels were evaluated using the Perceived Stress Scale. The WHOQOL-bref was used to evaluate the perception of quality of life. Quantitative variables distribution was evaluated using Shapiro-Wilk's test. For the analyses of correlations among perceived level of stress, total quality of life score, and the physical health domain of the WHOQOL-bref, Pearson's correlation test was applied. The significance level adopted for this trial was 95%. The study was approved by the Committee of Ethics in Research with Human Beings.Results:When assessing the perceived level of stress with the total quality of life score, there was no significant correlation between those variables. However, there was an association between the perceived level of stress and the physical health domain of quality of life.Conclusion:Perceived quality of life was correlated with the physical health domain, and this result reinforces the importance of the facets that make up this area.
SUBJECTIVE WELL-BEING PADA REMAJA DARI KELUARGA BROKEN HOME
Authors: Astuti Yuli , Anganthi Nisa Rachmah Nuw 
Published: October 2017

This research aims to describe the factors influencing teenagers’ subjective wellbeing and the subjective well-being condition in broken home teenagers. This is a quantitative research with a phenomenology approach. The subjects are three junior high school students in the district of Wonogiri who has the following characteristics: (1) teenagers from broken home families and (2) 12 – 16 years old of ages. The data gathering methods include interview and observations. The data analyses procedurescovers open coding, axical coding and selective coding. The results show that the factors influencing subjective well-being in teenagers includes social support, parental guidance, gender, finance, and coping strategy. The subjective well-beingin Vn ad DN are better than informan An. It occurs in life satisfaction asspect and apparently showed in some facts, such as graduating elementary school with good grades and getting a bicycle as a present. Some acts that can bring positive effect covers vacation with the family, helping the family, sports championships and getting good grades at school. The acts that can bring negative effect include feeling guilty, do not have pocket money, negative thoughts toward father and the neighbours, thinking off father, getting bad grades, family loss, mother who always gets angry,and jealousy towards friends.
Peningkatan Kompetensi Supervisi Kepala Sekolah Melalui Supervisi Kelompok di Sekolah Dasar
Authors: Kusmanto Benedictus 
Published: October 2017

The research is aimed to: 1) describe the process of managerial supervision using group technique to improve the principals’ supervisory competence; and 2) imrove the principals’ supervisory competence at Gugus II Bima UPTD Dikpora Kecamatan Serengan of Surakarta academic year 2012/2013 through managerial supervision using group technique.The type of the research is an action research. The research was done at Gugus II Bima UPTD Dikpora Kecamatan Serengan of Surakarta. The subjects of the research were 6 principals at Gugus II Bima UPTD Dikpora Kecamatan Serengan of Surakarta. The data collecting techniques were done using observation, interview and document techniques. The data analysis technique was done using Kemmis and Taggart model.The research concludes that: 1) the managerial supervision processes were done in three stages, namely: initial stage, observation stage, and feed-back stage; and 2) the managerial supervision using group technique is effective in improving the principals’ supervisory competence at Gugus II Bima UPTD Dikpora Kecamatan Serengan of Surakarta academic year2012/2013. It is demonstrated by the score improvement in each cycles.
ANALISIS PEMBIAYAAN MUDHARABAH BERMASALAH PADA BMT MITRA HASANAH SEMARANG
Authors: Arifah Odi Nur 
Published: October 2017

Problematika kehidupan manusia selalu dilatarbelakangi oleh keadaan perekonomian yang semakin sulit. Mulai dari petani kecil, pengusaha kecil, pedagang kecil dan semua kegiatan yang berskala kecil. Mereka membutuhkan suatu bantuan dana untuk memfasilitasi bisnis mereka, maka BMT Mitra Hasanah Semarang mengembangkan produknya yaitu pembiayaan Mudharabah sesuai dengan perkembangan dunia perbankan dalam target peningkatan keuntungan dan menyejahteraan masyarakat. Dengan diberikannya pembiayaan tersebut, terkadang muncul adanya pembiayaan yang bermasalah yang disebabkan oleh adanya ketidakmampuan anggota untuk membayar tepat waktu atau jatuh tempo pembayaran dan terkadang diakibatkan dari usaha yang kurang lancar, dan lain-lain. Adapun cara untuk menangani pembiayaan mudharabah bermasalah ini antara lain Rescheduling, Restructing, dan Reconditioning.
Impact of E-Service Quality on Customer Satisfaction and Loyalty Empirical Study in India Online Business
Authors: Sundaram Vijayanand , Ramkumar D , Shankar Poorna 
Published: October 2017

Due to Globalization and advancement in technology, Electronic commerce business (e-Com) has witnessed an extensive growth together with enthusiastic competition. The intention of this study is to test the conceptual framework of customer perception on service quality online business and its impact on satisfaction and loyalty through e-commerce business and a sample of 539 respondents were selected through simple random sampling method in Tamilnadu State of India. The result revealed that there is a significant association found between the demographic variables like Marital Status, Gender and Awareness about email/internet operation of the customers and the e-service quality, Customer Satisfaction and Loyalty except with Educational qualification and Status of the Residing area. The factors Responsiveness and Trust were highlighted as significant predictors for customer satisfaction and loyalty except Customization. Regarding the association between the customer satisfaction and loyalty, it is revealed that all the variables under satisfaction were significantly and positively associated with loyalty.Keywords: e-commerce, Retailers, Customer satisfaction, Customer Loyalty