bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust Tomographic Full Waveform Inversion using Adaptive Amplitude Estimation
Authors: Almomin Ali 
Published: March 2019

Abstract
I examine the basis of slow convergence of tomographic full waveform inversion (TFWI) and discover that the reason behind it is the unbalanced effects of amplitudes and phase in the design of the regularization term. This imbalance results in a strong reliance of the kinematic updates on the amplitude fitting, slowing down the convergence. To mitigate the problem I propose two modifications to the tomographic inversion. First, by modifying the regularization term to focus more on the phase information, and second, simultaneously updating the source function for modeling. The adjustments reduce the gradient artifacts and allow for explicit control over the amplitudes and phases of the residuals.
Tomographic full waveform inversion (Symes, 2008; Sun and Symes, 2012; Biondi and Almomin, 2012) is an innovative inversion technique that preserves all the advantages and benefits of full waveform inversion (FWI) while at the same time bypassing its strict initial model requirement and cycle-skipping challenges. To reach this objective, TFWI alters FWI by merging its classical form with a modified form of wave-equation migration-velocity analysis (WEMVA). This combination displays itself as an extension of the velocity model through virtual axes (Biondi and Almomin, 2013).
The modeling operator is able to match the observed data by extending the velocity model with the proper axis, no matter what the accuracy of the initial model is, by using kinematic information from the extended axis with disregard to the occurrence of cycle skipping. The inversion is set up to extract all the essential information from the virtual axes and smoothly fold them back into their original, nonextended form of the model. The kinematic and dynamic information of the data were successfully inverted with exceptional robustness and precision.
Even though cycle-skipping is not an issue with TFWI, this method creates its own challenges, which are; its high computational cost and the big number of iterations that it needs (Almomin and Biondi, 2013). The conventional FWI uses only a single frequency per iteration to match the phase (Pratt, 1999; Shin and Ha, 2008). Not using amplitudes reduces the accuracy of the solution because it prevents the simultaneous inversion of scales. Modifying the gradient calculation is another method that is used to reduce some "kinematic" artifacts (Fei and Williamson, 2010; Shen and Symes, 2015). These methods are appropriate for image-domain velocity analysis methods, such as WEMVA. The explicit calculations of the nonlinear modeling operator and residuals in the data space prevents it from being applied in TFWI.
Two adjustments to TFWI are proposed to reduce the slow convergence and allow for more control of the ratio between amplitude and phase. These adjustments are consistent in the framework of TFWI and allow for an accurate calculation of the gradient in the data space. The adjustments were tested and resulted in a reduction in the kinematic artifacts in the gradient.
The Use of Digital Core Analysis in Understanding the Effects of CO2 Aging to Carbonates Samples
Authors: Sazali Wan Muhammad , Md Shah Sahriza Salwani , Kashim M. Zuhaili , Kantaatmadja Budi Priyatna , Knuefing Lydia , Young Benjamin 
Published: March 2019

Abstract
PETRONAS is interested in monetizing X Field, a high CO2 carbonate gas field located in East Malaysian waters. Because of its location (more than 200 km from shore) and the preferable geological formation of the field, reinjection of produced CO2 back into the field's aquifer has been considered as part of the field development plan. To ensure feasibility, the PETRONAS R&D team has conducted a set of laboratory analyses to observe the impact of CO2 on the carbonate formations, through combining the use of static CO2 batch reaction experiments with advanced helical digital core analysis techniques. The analysis of two representative samples, from the aquifer zone is presented here. The initial state of the samples was determined through the use of theoretically exact helical micro computed tomography (microCT) techniques. The images were processed digitally to determine the porosity and calibrated with RCA to ensure the reliability of digital core analysis results. After scanning, both plugs were saturated with synthetic brine with similar composition as the fields' formation brine and aged with supercritical CO2 at reservoir temperature and pressure for 45 days. After 45 days, the aged core plugs underwent post reaction analysis using micro-CT scan and image processing software. Based on macroscopic observation, the core plugs showed no changes after aging with supercritical CO2 at high pressure and high temperature (HPHT) as per reservoir condition. However, analysing the high resolution micro CT images, the team was able to determine the changes in porosity before and after CO2 aging, which are around 1%.
Standardize/Simplify Water Flood Pattern Reviews
Authors: Al-Yazeedi Zeyana , Al-Zaabi Yousuf , Al-Oraimi Mahmood , Al-Kiyumi Wafa , Al-Rawahi Ashwaq , Al-Tobi Kifah , Al-Gheithy Ali 
Published: March 2019

Abstract

Objective/Scope
Water flood WF accounts for 40% of Petroleum Development Oman PDO's oil production and volumes. A proper WF management is a key to realize that. This project aims to standardize and simplify WF performance review process, which is very important part of WF management.

Methods, Procedures, Process
The current condition of WF performance review vary from field to another in term of frequency of conducting the reviews i.e, once a year, quarterly which resulted in missing the opportunities to improve the WF performance on the right time.
Different in house tools and databases are used to prepare the technical materials for the review meeting. As a result, different fields have different way of presenting the technical materials to the reviewers across the company, so no standard pattern review template available and multiple sources for data are used. The field petroleum engineer takes up to 4 hours to prepare the technical material for one pattern review and usually senior or high skills PE requires generating different type of plots. When the Pattern review conducted almost 4 hours for the individual petroleum engineers spent during one pattern review.
The proposed counter measures for this project were to replace the review frequency to exception or requirement base to ensure no missed opportunities. As well as standardizing the technical materials for WF pattern review using a single tool/source. The standard template has to fit all patterns in a field. It has to be accessible, with good visualization, and secured storage
A Successful pilot run in one of the water flood fields in North Oman with 30+ WF patterns and has demonstrated the following results; standard review template developed within one source data platform. The pattern review was conducted on exceptional based which was a proactive approach. The PE team managed to generate extra optimization opportunities which resulted in proven an increased in oil production of +30 m3/d from 5 patterns. PE saved 3.5 hours/ pattern in preparation. The reviewers appreciated the improvement of quality of the technical materials, which create direct focus on issues identified based on exception. All the technical material were easy to generate by any less experience engineers.
To maintain sustainability of the achieved improvements, some lean tools have been used. These tools are summarized in the following points; Standard operating procedures (SOP); two SOPs were generated, one to set up the tool and the other to do the review.Visual management (VM); was also generated to keep track the pattern review and ensure healthy WFM and.Leader Standard Work (LSW); it was completed to ensure sustainability through leader ship support.
Cost and Time Effective Stimulation Technique in Horizontal Cemented Liner Application in Carbonate Reservoir With HPCT Hydrajetting Tools
Authors: Alfayiz Mohammad , Alaithan Monaf , Alharbi Abdulaziz , Khan Faisal 
Published: March 2019

Abstract
Tight carbonate gas reservoirs require stimulation in order to establish commercial viability. In order for the development plan to be considered effective and successful, two main parameters have to be studied and evaluated, time, and cost. The conventional method to stimulate tight carbonate reservoirs is bull heading acid fracturing treatment, which is costly and time consuming for multi stages wells, not excluding the high treatment pressure requirement and risk associated with it. Conventional plug and perf technique includes e-line operations to perforate with guns, acid fracturing treatment by bullheading, and e-line operations to set plugs for every single stage.
A novel acid-soluble abrasive material, was implanted and tested as an economical and time effective alternative solution. The technique involves perforating through cemented liners utilizing the abrasive material flowed by low volume acid surgesqueeze. By using this technique time and cost associated with the conventional plug and perf technique, can be reduced and achieve even better result with less cost and time.
The wells that were stimulated with this technique, were tested and proven superior in terms of production rate over the conventional plug and perf technique in the short term. More evaluation to be done on the wells over the long term and evaluate if they are going to sustain the production over time.
This paper provides a brief summary about the technique. Also, will discuss in details, the cost and time effectiveness, the short term result, and compare it with the conventional plug and perf technique.
Effects of Pre-Existing Fractures on Carbonate Matrix Stimulation Studied by Large-Scale Radial Acidizing Experiments
Authors: Aidagulov Gallyam , Gwaba Devon , Kayumov Rifat , Sultan Abdullah , Aly Moustafa , Qiu Xiangdong , Almajed Haidar , Abbad Mustapha 
Published: March 2019

Abstract
Carbonate reservoirs host a significant amount of hydrocarbon reserves in the Middle East and worldwide. In matrix acidizing stimulation, hydrochloric acid (HCl) is commonly injected into the well at pressures less than fracturing pressure to dissolve the carbonate rock and create high-conductivity channels, known as wormholes. Wormholes propagate through the damaged near-wellbore zone connecting the well with the reservoir. In this work, we aim to study the effects of pre-existing fractures on wormhole development.
Matrix acidizing processes were reproduced in controlled laboratory experiments where a 15% HCl solution was injected into a borehole drilled in a carbonate block sample containing pre-existing fractures, allowing the acid to penetrate radially into the rock sample. The experiment was conducted inside a polyaxial load frame to accommodate large block samples (20×16×16 in.). Prior to acid injection, the block was fully saturated with water and taken to 2,000-psi pore pressure and 4,000-psi confining stress to simulate downhole conditions. To evaluate the created wormholes, the tested block was cut open along the fractures followed by X-ray CT scanning of selected zones.
Here we report experimental results for matrix stimulation of one Indiana limestone block containing a series of parallel pre-existing fractures. Acid was injected at a constant rate through the 1-in. diameter borehole containing an 8-in.-long openhole section in the center of the block. Although the acid injection pressure was maintained below the pressure required to open the fractures, acid breakthrough was found to be governed by the pre-existing fractures. Indeed, unlike similar radial acidizing experiments in intact blocks, there were no indications of wormholes exiting the outer faces of the block. Moreover, the post-test evaluation of the central fracture along the openhole section clearly revealed the wormholes that etched the fracture faces. However, a closer look into the stimulated openhole section showed that the wormholes initiated in other directions inside the matrix as well. An X-ray CT scan of a 4-in. diameter cored borehole regions allowed us to compare the density and characteristics of the wormhole growth along the fracture and into the matrix.
Although radial acidizing experiments describe more closely real conditions of matrix acidizing, few cases have been published, particularly for large-block experiments. The large-scale block experiments presented in this study provide new insights on the impact of pre-existing fractures on wormholing mechanisms.
Tiempo e interpretación en la teoría de la relatividad
Authors: Simesen de Bielke Martín 
Published: March 2019

En la teoría de la relatividad se presenta el problema de la realidad o irrealidad de los fenómenos relativistas relacionados con el espacio-tiempo (dilatación de la duración, contracción de la longitud, quiebre de la simultaneidad provocada por el movimiento de escalas y relojes). En la primera parte de este artículo se esboza el marco de la discusión en relación con este punto de controversia. Luego de que el marco ha quedado establecido, se toman en consideración algunos experimentos mentales de Einstein para demostrar por qué el tiempo relativista no puede ser caracterizado ni como algo real ni como mera apariencia. A lo largo del análisis crítico, la función de la expresión «como si» juega un rol importante en la comprensión de por qué el tiempo es interpretación, antes que una «cosa» real o una «ilusión».
Analysis of the Essential Oils of Five Artemisia Species and Evaluation of their Cytotoxic and Proapoptotic Effects
Authors: Tayarani-Najaran Zahra , Akaberi Maryam , Hassanzadeh Bahareh , Shirazi Nazila , Asili Javad , Al-Najjar Hadi , Sahebkar Amirhossein , Emami Seyed Ahmad 
Published: March 2019

Background:In this study, the essential oil composition and cytotoxic activities of five Artemisia species were determined.Methods:The collected plants were water-distilled separately to obtain oils which were then subjected to gas chromatography (GC) and gas chromatography/mass spectrometry GC/MS analyses to identify their compositions. Cancer cells were exposed to different concentrations of samples and cell viability was measured using AlamarBlue® assay. Apoptotic cells were analyzed by propidium iodide (PI) staining and flow cytometry.Results & Conclusion:To study the amount of pro-apoptotic proteins and the apoptosis mechanism, Western blot method was used. Although all samples were cytotoxic at the highest concentration, the oil of A. kulbadica showed the strongest activity among other plants. Carvacrol (IC50 21.11 μg/ml) had the most cytotoxic effects among other components. Carvacrol, 1,8-cineole and 4-terpineole caused an increase in the amount of Bax protein and cleaved peroxisome proliferator-activated receptors (PPAR) and caspase proteins in DU 145 cells.
The Role of Vitamin D and Sunlight Incidence in Cancer
Authors: Camara Alice B. , Brandao Igor A. 
Published: March 2019

Background:Vitamin D (VD) deficiency affects individuals of different ages in many countries. VD deficiency may be related to several diseases, including cancer.Objective:This study aimed to review the relationship between VD deficiency and cancer.Methods:We describe the proteins involved in cancer pathogenesis and how those proteins can be influenced by VD deficiency. We also investigated a relationship between cancer death rate and solar radiation.Results:We found an increased bladder cancer, breast cancer, colon-rectum cancer, lung cancer, oesophagus cancer, oral cancer, ovary cancer, pancreas cancer, skin cancer and stomach cancer death rate in countries with low sunlight. It was also observed that amyloid precursor protein, ryanodine receptor, mammalian target of rapamycin complex 1, and receptor for advanced glycation end products are associated with a worse prognosis in cancer. While the Klotho protein and VD receptor are associated with a better prognosis in the disease. Nfr2 is associated with both worse and better prognosis in cancer.Conclusion:The literature suggests that VD deficiency might be involved in cancer progression. According to sunlight data, we can conclude that countries with low average sunlight have high cancers death rate. New studies involving transcriptional and genomic data in combination with VD measurement in long-term experiments are required to establish new relationships between VD and cancer.
Exploring the Chemistry and Therapeutic Potential of Triazoles: A Comprehensive Literature Review
Authors: Jain Ankit , Piplani Poonam 
Published: March 2019

:Triazole is a valuable platform in medicinal chemistry, possessing assorted pharmacological properties, which could play a major role in the common mechanisms associated with various disorders like cancer, infections, inflammation, convulsions, oxidative stress and neurodegeneration. Structural modification of this scaffold could be helpful in the generation of new therapeutically useful agents. Although research endeavors are moving towards the growth of synthetic analogs of triazole, there is still a lot of scope to achieve drug discovery break-through in this area. Upcoming therapeutic prospective of this moiety has captured the attention of medicinal chemists to synthesize novel triazole derivatives. The authors amalgamated the chemistry, synthetic strategies and detailed pharmacological activities of the triazole nucleus in the present review. Information regarding the marketed triazole derivatives has also been incorporated. The objective of the review is to provide insights to designing and synthesizing novel triazole derivatives with advanced and unexplored pharmacological implications.
Synthesis, Docking Studies into CDK-2 and Anticancer Activity of New Derivatives Based Pyrimidine Scaffold and Their Derived Glycosides
Authors: Rahman Adel A.H. Abdel , Nassar Ibrahim F. , Shaban Amira K.F. , EL-Kady Dina S. , Awad Hanem M. , El Sayed Wael A. 
Published: March 2019

Background & Objective:New diaryl-substituted pyrimidinedione compounds, their thioxo derivatives as well as their bicyclic thiazole compounds were synthesized and characterized.Methods:The glycosylamino derivatives of the synthesized disubstituted derivatives of the pyrimidine scaffold were also prepared via reaction of the N3-amino derivatives with a number of monosaccharides followed by acetylation.Results:The anticancer activity of the synthesized compounds was studied against human liver cancer (HepG2) and RPE-1cell lines. Compounds 2a, 2b, 3a and 12 showed potent activities with IC50 results comparable to that of doxorubicin.Conclusion:Docking investigations into Cyclin-dependent kinase 2 (CDK-2) enzyme, a potential target for cancer medication, were also reported showing the possible binding interaction into the enzyme active site to support their activity behavior.
Synthesis of Novel Bis-pyrazole Derivatives as Antimicrobial Agents
Authors: Muhammad Zeinab A. , Alshehrei Fatimah , Zayed Mohie E.M. , Farghaly Thoraya A. , Abdallah Magda A. 
Published: March 2019

Background:
bis-heterocycles especially those containing pyrazole moiety display much
better antibacterial activity than mono heterocycles.

Objective:
Herein, we synthesised a series of new bis-pyrazoles and investigated their antimicrobial
agents.

Methods:
A novel series of bis-pyrazole derivatives have been synthesized in good yield by coupling
reaction of cyanoacetic acid 4-[(2-cyano-acetyl)-hydrazonomethyl]-benzylidene-hydrazide with a
number of diazonium salts of aromatic amines in DMF in the presence of NaOH. Refluxing of the produced
hydrazones with hydrazine-hydrate in ethanolic solution afforded the respective bis-pyrazoles.
On the other hand, the reaction of bis(cyanoacetic acid hydrazide) derivative with a diversity of hydrazonoyl
chlorides in dioxane under reflux gave bis-pyrazoles.

Results:
The structures of all the products were discussed and assured from all possible spectral data as
well as for the elemental analysis. In addition, the results of the antimicrobial activity examination of
selected derivatives revealed a high strength of some tested compounds compared to standard bactericides
and fungicides utilized. Molecular docking of the newly synthesized compounds into the Enoyl
ACP reductase active site supported the in vitro antimicrobial activity. All the tested compounds could
fit in the enzyme binding pocket with significant binding affinities (-7.040 to -9.141 Kcal/mol).

Conclusion:
The good results of the antimicrobial examination of the newly synthesized bis-pyrazoles
comprise the considerable evidence of the importance of bis-heterocyclic compounds which encourages
us to continue designing and synthesising a novel series with potent biological activity in the future.
A Comprehensive Review on the Screening Models for the Pharmacological Assessment of Antiulcer Drugs
Authors: Mishra Abhinav P. , Bajpai Ankit , Chandra Suresh 
Published: March 2019

Background:Due to inappropriate diet, smoking, alcohol consumption, regular use of drugs like NSAIDs and sedentary lifestyle, one may feel upper abdominal pain which may be the predictor of the gastrointestinal disorder called Peptic Ulcer. When an imbalance occurs between the defensive factor and aggressive factor of the stomach, ulcer formation in the esophageal lining, stomach, or duodenum takes place. This leads to the formation of small sores that cause pain. Another condition that synergizes the abdominal pain is vomiting materials which look like coffee grounds, blood in the stool, black or tarry stools. This pain may increase after lunch or dinner. This problem persists, that often leads to the gastroenterologist's consultation.Objective:There are many antiulcer screening models present for the determination of antiulcer activity of the drug molecule. The main objective of this study is to find which model is best for the determination of antiulcer activity.Methods:A literature search was conducted on the databases namely Science direct and PubMed with the help of different keywords such as "Anti-ulcer", "In-vitro models" and "In-vivo models". The search was customized by applying the appropriate filters so as to get the most relevant articles to meet the objective of this review article.Result:There are different research and review papers based on the antiulcer screening models for the determination of antiulcer activity of new drug molecules.Conclusion:On the basis of our study, we found some useful models for the antiulcer activity of drugs and suggested that, if we use in-vitro and in-vivo methods together, then we may obtain the most relevant result in our research area.