bluuebunny/crossref_metadata_2025 huggingface dataset:
An audit of US FDA warning letters issued to sponsors, institutional review boards and investigators over a six-year period
Authors: Saxena Unnati , Bose Debdipta , Saha Shruti , Gogtay Nithya J , Thatte Urmila M
Published: December 2021

The present audit was carried out with the objective of evaluating warning letters (WLs) issued to trial sponsors, clinical investigators and institutional review boards (IRBs) by the United States Food and Drug Administration during a six-year period and compare it with two similar earlier audits. WLs were reviewed and classified as per stakeholders and further categorised as per predefined violation themes. The chi-square test was performed for trend analysis of WLs. A total of 62 WLs were issued to the three stakeholders. The maximum number of WLs were issued to the clinical investigators (36/62, 58.06%), followed by sponsors (19/62, 30.64%), and least to the IRBs (7/62, 11.29%). Among sponsors, lack of standard operating procedures for the monitoring, receipt, evaluation and reporting of post-marketing adverse drug events was the most common violation theme (8/19, 42.1%). Among clinical investigators, deviation from investigational plan was the most common violation theme (31/36, 86.11%.). For IRBs, inadequate documentation was the most common violation theme (6/7, 85.71%). We saw an overall reduction in the number of WLs issued to the stakeholders. Thus, we identified multiple areas on which each stakeholder should work for improvement.
The effects of design parameters on the elastic properties of PLA-Graphite composites fabricated by 3D printing
Authors: Rubashevskyi Viktor , Shukayev Sergiy
Published: December 2021

Abstract. Recently, in 3D printing, consumables such as polymers, metals, and ceramics are being replaced with composites, which makes it possible to enhance the mechanical and other important properties of products.

The purpose of this study is to investigate the effects that the orientation and thickness of the layers of printed samples made of composite monofilament based on PLA+ with a 5% content of layered graphite, and other such parameters, have on the elastic properties of the printed samples. The samples, developed in accordance with the DSTU EN ISO 527-2: 2018 standard, were printed using the FDM technology with three different orientation angles (0o, 45o, 90o) and three layer thicknesses (0,1 mm, 0,2 mm, 0,3 mm) for each angle. Tensile tests were performed using the complete factorial experiment design (consisting of two factors at three levels, with nine tests in total). Based on the results of these tests, a regression model was developed to describe the relationship between the (effective) modulus of elasticity and the selected design parameters.
Characteristics of statistical properties of deformation defects of structural metallic materials within elastic deformations
Authors: Maylo Andriy , Pisarenko Georgiy
Published: December 2021

At this paper was established result of the correlations characteristics of structural parameters of low-carbon steels during periodic loading under elastic deformations. According to the results of the research, the kinetic characteristics of the influence of the load parameter on the distribution of deformation defects of the surface layer of structural materials under elastic deformations are obtained. The regularities of the influence of elastic deformations on the distribution of discrete surface properties are revealed. Linear dependences of the parameter of distribution of discrete relief properties of the deformed surface on loading are revealed. The regularities of the influence of elastic deformations on the distribution of discrete surface properties are revealed. It is established that regardless of the type of load, the surface density of deformation defects of scattered fracture accumulates in the mother to a certain state of damage, which is characterized by the current state of density of elements of deformation defects.
Theory of creation and practice of using vibrating machines for various technological purposes
Authors: Nazarenko І. , Dedov O. , Sviderskyy А. , Bondarenko А. , Zapryvoda А. , Mishchuk E. , Nesterenko М.
Published: December 2021

The paper presents the results of the study of vibration machines for technological purposes. The theory of

joint movement of working bodies of vibrating machines and the processed environments modeled by discrete-continuous

systems is developed. The complex approach to the decision of a question of modeling of difficult dynamic systems with variable characteristics of elastic elements at realization of working process is considered. The parameters of resonant vibration systems with directional oscillations for surface compaction, polyphase oscillations and spatial oscillations are determined. The basic principles of such approach to the decision of a question of rational use of materials at designing

of cars are resulted. New designs of machines and their components are offered. The data on researches which are introduced in educational process, normative documentation and in the industry are resulted.
About the possibility of creation of sealed strong structures of rocket and space equipment FDM printing methods
Authors: Salenko Oleksandr , Avramov Kostyantyn , Derevianko Іgor , Samusenko О. , Rogulin V. , Lithot O.
Published: December 2021

The work shows the possibility of manufacturing products for rocket and space technology using the additive FDM-printing technology. The object of research is the nozzle plugs of the "membrane" type. Taking into account the specific-strength properties of the product during its operation during operation, as well as the features of the FDM-process, the design was optimized, the regularities of the formation of its properties were established. An impregnation technology has been developed to seal the product. The equipment was designed and pneumatic tests were carried out. The properties of materials were investigated taking into account their guaranteed shelf life for 12 years of operation under accelerated climatic tests. It is shown that the production of products by FDM-printing methods is promising and expedient, since the properties being formed are predictable, achievable and stable.
“Innovative Comprehensive Partnership”: Sino-Israeli Relations in the Fields of Economy and Security
Authors: Morozov V. , Baykov A. , Gnevasheva V. , Mikaelian A.
Published: December 2021

The article is devoted to the analysis of the current state of Sino-Israeli relations which two nations describe as the Innovative Comprehensive Partnership. The relevance of the topic under the consideration stems from two primary factors – the growing importance of China in the international arena and the implementation of Belt and Road Initiative amid growing tension between the US and China. The research focuses on the economic realm of Sino-Israeli relations as well as security and cyber-security cooperation. The paper met these twin research aims through an extensive study of relevant materials in English, Russian, Hebrew, and Chinese and the implementation of econometric research. The analysis shows that Sino-Israeli relations are exposed to global factors in the world arena. However, it is Washington’s stance that has large impact on Israel’s and China’s foreign policy strategies. What is more, the US factor influences indirectly the nature of bilateral relations through the US policy in the Eurasian continent. The research produced a number of findings: the econometric estimates obtained suggest that despite the US influence trade relations and economic cooperation between China and Israel are relatively stable. On the other hand, the political cooperation between China and Israel can be compared to the pendulum as it is determined by Israeli-American and Sino-American relations as well as Washington’s policy in the respective regions. The study also found that in the medium-term Sino-Israeli cooperation is likely to focus primarily on trade and economic spheres. At the same time, the article concludes that the economic realm is still heavily influenced by a number of factors such as the rise of protectionism in the world economic system, Sino-American trade war and the growing concerns within Israel due to increasing role of China in Israel’s economy.
Faceless Leadership of American Public Diplomacy: HR Crisis in the Post-Bipolar Era
Authors: Artamonova U.
Published: December 2021

This article focuses on workforce policies trends in the American public diplomacy institutions. The author compares tendencies regarding HR policy, e. g. frequency of leadership change, length of timespans between nominations, the ratio of acting and confirmed nominees during the age of the United Stated Information Agency (USIA) and after its disbandment in 1999. Comparison demonstrates a considerable change of patterns: since 1999, persons in charge of the American public diplomacy institutions have been rotating more often, and positions themselves stayed vacant longer than they did in the 20th century. There have been many acting nominees during the past decade, whereas in the time of the USIA there has been none. In addition, the article studies characteristics of both the USIA directors and Under Secretaries of State for Public Diplomacy and Public Affairs. The analysis of education, professional background, personal relationship with the U. S. President (or the lack of it) demonstrated that standards for the Under Secretary of State for Public Diplomacy and Public Affairs position applicants are significantly lower than the ones that were applied to candidates for the directorship of the USIA. With the results obtained, the author arrived to a conclusion that the change of HR policy in the American public diplomacy sphere indicates the lack of interest in the particular dimension of foreign policy among the political leadership of the U.S. in comparison to the age of the Cold War. This conclusion agrees with the fact that since 1990s, the American public diplomacy remains in crisis: no major reforms of institutions since 1999, unsuccessful attempts to develop a comprehensive strategic document for public diplomacy, frequent piques of anti-Americanism in the international public opinion in the 21st century. The article argues that the absence of a prominent leader in the American public diplomacy who would have stayed in the office for considerable amount of time, been a confidant of the President and thus an active participant of the formation of a national political vision, possessed outstanding professional experience, is both the consequence of the crisis in the U.S. public diplomacy and the factor that contributes to this crisis remaining unsolved.
Post-Soviet De Facto States: Trajectories of Their Struggle for Sovereignty
Authors: Markedonov S.
Published: December 2021

The de-facto statehood is a multi-faceted phenomenon of the international politics. They are key elements of the ethno-political conflicts in the contexts of collapse of multi-ethnic federations, empires as well as processes of decolonization. In spite of growing scientific interest to this phenomenon de-facto states’ studies face a clear lack of interdisciplinary research. Most of papers are devoted to the conflict dynamics, issues of theory and international law issues or cover some particular country cases. The topical perspectives of de-facto states are often studied with no special attention to their historical background. The offered article examines the trajectories of the struggle for the sovereignty of Post-Soviet de facto entities. The author provides a comprehensive analysis of their evolution in the last years of the existence of the Soviet Union and in the period after of the USSR dissolution. The article offers a typology of de facto states. From the author’s point of view, we can talk about two generations of such formations. If the first generation was a result of the once single state collapse as well as growing fight for revisiting statuses of former union and autonomous entities, the second one was a consequence of the crisis of nation-building in the newly independent states and the growing competition between Russia and the West for influence in Eurasia. The article presents the evolution of the trajectories of the de facto states struggle for sovereignty in the context of three successive Post-Soviet regional orders. According to the author, all the Post-Soviet unrecognized republics were formed in the conditions of the destruction of the constitutional consensus of 1977–1978. However, then the trajectories of asserting and protecting the sovereignty of the de facto entities diverged significantly. The author evaluates the general and special features of these processes. In his view, this dynamic has depended on the regional context changes (revision of “the Belavezha order”) but at the same time, changes within de facto states seriously influenced the international environment.
Research Potential of Wargames in International Relations Studies
Authors: Eremin A.
Published: December 2021

In this article, the author raises the question of using wargames as a method of research in international relations. The paper analyzes the extensive historiographic base devoted to the issue of adapting classic military-historical simulation games to other fields of science, including international studies. The author thoroughly analyzes the experience of the Western academic community in applying wargames to obtain empirical data in researches on various topics and issues. The paper describes the main characteristics of wargames as a research methodology, mentions primary advantages and potential disadvantages while providing extensive examples of both. The author concludes that wargame is a valuable research tool, which allows the study of a wide range of topics, including those where the use of other research methods is impossible or limited. One of the bottom-lines of the article is that wargames can be considered both a qualitative and a quantative method of research, which makes imitational modeling a potential answer in the ongoing argument on the methodology more suitable for social sciences and international relations in particular. The author also pays special attention to the applicability of wargames to the subject sphere of international relations and touches upon the issue of the future of this mechanism in scientific research, taking into account the existing global trends. In particular, the author speaks of the objective need to develop unified mechanisms for the implementation of wargames in the digital environment, which would solve many potential issues and risks affecting the validity of the obtained results, and, in general, would simplify the use of wargames for scientific purposes. One of the important conclusions that are drawn in the paper is the objective need to digitalize existing wargames, which would allow to avoid existing complications of organizational nature, make wargaming more accessible and applicable to various types of research in the international relations studies.
The Present and Future of Employment: Ibero-American Context
Authors: Ermolieva E.
Published: December 2021

The world of work is changing rapidly. The impact of the current megatrends on the future of employment has been widely debated around the world and became a focus of numerous reviews of international organizations. The Sars-Cov-2 pandemic has added even more urgency to the discussion and has affected more countries, including Iberian Peninsula and Latin America. Moreover, the COVID-19 pandemic-induced lockdowns and related global recession of 2020 have created a highly uncertain outlook for the labor market and accelerated the arrival of the future of work. COVID-19 has shown us how rapid change can destroy jobs. But at the same time, it must be recognized that the labor market has fundamentally changed within just a few months of the pandemic with the spread of some non-standard employment such as tele- and platform work. Thus, the COVID-19 became a catalyst for the rapid changes that will define the future of the labor market in different parts of the world. But, as some results show, digital transformation in employment brought serious inequalities, called the digital divide with its multidimensional impact. For example, a new digital gap has emerged between the global North and the global South. Through these optics, the article attempts to summarize the results of studies that are monitoring how labor markets are changing in different regions of the world. And the main aim is to better understand the specifics of the situation in Spain, Portugal and Latin American countries which collectively are integral parts of the Ibero-American community. To achieve the goal, the principal tools of scientific analysis were used, including collecting and analyzing a significant body of empirical data from international sources and publications of national departments for labor and employment. The review helped to identify the basic features of the current moment and possible prospects in the development of the employment sector in Iberoamerica. Following the principle of comparative analysis research, the author comes to the conclusion that, on the one hand, the processes similar to the global trends are present, but, on the other hand, the peculiarities determined by the national characteristics of the Ibero-American content are quite obvious.
COMPANY COMPETITIVENESS AND COMPETITIVE ADVANTAGES IN TOURISM AND HOSPITALITY
Authors: Cetinski Vinka , Milohnić Ines
Published: December 2021

Connection between competitive strategies and competitive advantages is described in details in this paper. Model of the research is located on the company level in tourism and hospitality. Applicative basis of the paper is founded on the Diamond of Competitiveness (Case Study) usage and is based on the qualitative research of small entrepreneurship in tourism and hospitality. The fact that every strategy is based on creating and sustaining competitive advantages implies that the principal task of company management is shaping company’s competitive advantages. Management uses its knowledge, controls available resources and manages business processes and events of a company in tourism and hospitality.
ORGANIZATIONAL SILENCE: A SURVEY ON EMPLOYEES WORKING IN A CHAIN HOTEL
Authors: Ehtiyar Rüya , Yanardağ Melek
Published: December 2021

The purpose of this study is to research reasons of silence in organizations, its effects, results and applications which can minimize or remove silence by explaining silence concept. Other purpose is to measure attitudes of managers and employees towards silence climate in organizations. In this sense, Questionnaires were applied a chain hotel company which has 3 hotels in Antalya, 278 questionnaires were delivered and 135 of them were taken. Questionnaire data was analyzed, and according to the results, some implications were proposed.
Black Holes or an Objects without Event Horizon?
Authors: Verozub Leonid
Published: December 2021

In this paper, we investigate the question of whether the generally accepted interpretation of the supermassive object in M87, investigated by EHT collaboration, is the only possible one. There are grounds for this, in particular, due to the detection of a magnetic field in its vicinity. For this purpose, the stability of self-gravitating objects is investigated based on the correct definition of the energy of gravitation in the framework of the bi-metric approach to the theory.
The Role of Trees in Winter Air Purification on Children’s Routes to School
Authors: Hoppa Adrian , Sikorska Daria , Przybysz Arkadiusz , Melon Marta , Sikorski Piotr
Published: December 2021

Air pollution is now considered to be the world’s largest environmental health threat accounting for millions of deaths globally each year. The social group that is particularly exposed to the harmful effects of air pollution is the children. A daily route to school can constitute an important component of children’s physical activity, but air pollution can pose a threat to their health. Numerous studies have proved high loads of PM can be effectively reduced by vegetation. Little is however known, whether vegetation can also reduce PM during the leaf dormancy period. In this study, we investigated the role of trees in PM removal on children’s routes to schools during winter. We investigated walking routes to selected schools in Warsaw, by examining the adjacent vegetation and PM2.5 and PM10 concentrations and the presence of local black-smoke-belching stoves. We found that proximity to local CHP emitters had the strongest impact on pollution on the way to schools, while not finding a significant relationship between dense greenery and PM loads. Even more, the highest density of vegetation along walking routes tended to stimulate higher PM concentrations. The results obtained show the poor performance of tree canopy in reducing PM loads during winter.
Evaluating Olympic Pictograms Using Fuzzy TOPSIS – Focus on Judo, Taekwondo, Boxing, and Wrestling
Authors: kyoungho Choi , Bongseok Kim , Choi Jinhee
Published: December 2021

This study evaluated the ranking of comprehensibility of the pictograms for judo, taekwondo, boxing, and wrestling used in the six games from the 27th Sydney Olympics in 2000 to the 32nd Tokyo Olympics in 2021. The evaluation was done using the Fuzzy TOPSIS method, one of the multi-criteria decision-making methodologies commonly used in economics and others fields. The results are as follows. The first, pictograms from the 2008 Beijing Olympics ranked first in three sports: taekwondo, boxing, and wrestling, but there were no pictograms that consistently ranked first or sixth in all sports. Second, the result of the sensitivity analysis shows a possibility that the ranking will be reversed if the weight of the evaluation factors changes, but in the 1000-time repetitive prediction, the better the evaluation ranking, the closer the value of the priority ranking to the ideal solution on average even if the weight changes.
Linking Serpentinization and Weathering of Peridotite: A Study on the Mineralogical and Geochemical Evolution of the Sta. Cruz Nickel Laterite Deposit, Zambales, Philippines
Authors: Aquino Karmina , Arcilla Carlo , Schardt Christian , Tupaz Carmela
Published: December 2021

While there are extensive studies on the mineralogy and geochemistry of laterites worldwide, the temporal and spatial mineralogical development of a typical nickel laterite profile is still poorly constrained. In this study, we present a detailed mineralogical and geochemical characterization of samples systematically collected from a nickel laterite profile at the Sta. Cruz nickel laterite deposit, Zambales, Philippines, to describe the temporal and spatial development of the laterite profile. Wavelength-dispersive X-ray fluorescence spectroscopy (WDSXRF), mass balance-element mobility calculations, transmitted and reflected light microscopy, and previously reported results from coupled X-ray diffraction (XRD) and Rietveld refinement analyses, reveal that the laterite profile investigated is composed of two main horizons: the limonite and saprolite zones, separated by a thin transitional zone. The main zones are further subdivided into subzones based primarily on the mineral assemblage and major element chemistry: upper limonite, lower limonite, transitional zone, upper saprolite, and lower saprolite. Late-stage garnierite veins were observed cutting the upper and lower saprolite subzones. Investigation of the structure of goethite within the limonite zone via Rietveld refinement show that the crystallinity of goethite decreases with increasing Ni content and increasing crystallite size. This suggests that upwards through the limonite zone, as goethite ages, its crystallinity increases which possibly results in the removal of Ni from its crystal structure and eventual remobilization to the lower laterite zones. We propose a spatio-temporal model of the formation of the Sta. Cruz laterite consisting of four stages: (1) early-stage alteration, (2) continued serpentinization and volume expansion, (3) late stage serpentinization and incipient oxide formation, and (4) goethite ageing and garnierite formation.
Transient Receptor Potential Vanilloid Type 1 Contributes to Modulate the Nitric Oxide Pathway and Oxidative Stress in the Isolated and Perfused Rat Heart during Ischemia and Reperfusion
Authors: Castrejón-Téllez Vicente , Del Valle-Mondragón Leonardo , Pérez-Torres Israel , Guarner-Lans Verónica , Pastelín-Hernández Gustavo , Ruíz-Ramírez Angélica , Díaz-Juárez Julieta Anabell , Varela-López Elvira , Oidor-Chan Victor Hugo , Vargas-González Alvaro , Martínez-Memije Raúl , Flores-Chávez Pedro , León-Ruíz Bruno , Arriaga-Carrillo Sergio , Torres-Narváez Juan Carlos
Published: December 2021

The transient vanilloid receptor potential type 1 (TRPV1) regulates neuronal and vascular functions mediated by nitric oxide (NO) and by the calcitonin gene-related peptide (CGRP). Here we study the participation of TRPV1 in the regulation of myocardial injury caused by ischemia-reperfusion and in the regulation of NO, tetrahydrobiopterin (BH4), the cGMP pathway, CGRP, total antioxidant capacity (TAC), malondialdehyde (MDA) and phosphodiesterase-3 (PDE-3). Isolated hearts of Wistar rats were used (according to Langendorff) to study the effects of capsaicin (CS), capsazepine (CZ) and CZ+CS treatments. The hearts were divided into three subgroups; 1) perfusion, 2) ischemia and 3) ischemia-reperfusion. In all groups we studied cardiac work and levels of NO, cGMP, BH4, CGRP, TAC, MDA and PDE-3 in ventricular tissue. Western blots were used to determine the expressions of eNOS, iNOS and phosphorylated NOS (pNOS). Structural changes were determined by histological evaluation. CS prevented damage caused by ischemia-reperfusion by improving cardiac work and the levels of NO, cGMP, BH4, TAC and CGRP. TRPV1 and iNOS expression were increased under ischemic conditions, while eNOS and pNOS were not modified. We conclude that the activation of TRPV1 constitutes a therapeutic possibility to counteract the damage caused by ischemia and reperfusion by regulating the NO pathway through CGRP.
The "Environmental Lawsuit" as an Instrument of Preventive Protection of the Constitutional Right to Healthy Environment in the Law of the Republic of Serbia
Authors: Miščević Nikolina , Dudás Attila
Published: December 2021

A lot of attention has been paid to the environment and its protection in Serbian legislation. The right to healthy environment is guaranteed by the Constitution, and in the last two decades numerous laws have been passed regulating various aspects of the environment in order to ensure its protection. The subject of the paper is the claim to eliminate the danger of damage, stipulated by the Law on Obligations from 1978. From the enactment of the law, this legal institution has been considered as a means suitable for providing preventive environmental protection, which is why it is often called an “environmental lawsuit” in Serbian legal theory.
Constitutional protection of the environment with particular regard to the Hungarian, German, Italian and Belgian constitutional regulation
Authors: Orosz Flóra , Suri Noémi , Hrecska-Kovács Renáta , Szőke Péter
Published: December 2021

Environmental protection has become a burning issue which plays a more and more important role in the world. The aim of this study is to give a picture of the constitutional regulation of environmental protection which is the highest legal source of a nation. Besides the Hungarian Fundamental Law, the German, Italian and Belgian constitutions were examined in the study. On one hand, we looked into how environment is regulated in the constitutions, as a right (right to environment) or a state task or objective (protect the environment). On the other hand, we analysed how related regulatory subjects appear in the constitutions, such as natural resources, future generations and sustainable development.
Is Discretionary Care Associated with Safety Among Medicare Beneficiaries Undergoing Spine Surgery?
Authors: Ko Hyunkyu , Brodke Darrel S. , Vanneman Megan E. , Schoenfeld Andrew J. , Martin Brook I.
Published: December 2021

Background:

Spine surgery and its corresponding costs have increased in recent years and are variable across geographic regions. Discretionary care is the component of spending variation that is independent of illness severity, age, and regional pricing. It is unknown whether greater discretionary care is associated with improved safety for patients undergoing spine surgery, as we would expect from value-based health care.

Methods:

We conducted an analysis of 5 spine surgery cohorts based on Medicare claims from 2013 to 2017. Patients were grouped into quintiles based on the Dartmouth Atlas End-of-Life Inpatient Care Index (EOL), reflecting regional spending variation attributed to discretionary care. Multivariable regression examined the association between discretionary care and safety measures while controlling for age, sex, race, comorbidity, and hospital features.

Results:

We observed a threefold to fourfold variation in 90-day episode-of-care cost across regions, depending on the cohort. Spine-specific spending was correlated with EOL quintile, confirming that spending variation is due more to discretionary care than it is to pricing, age, or illness severity. Greater spending across EOL quintiles was not associated with improved safety, and, in fact, was associated with poorer safety in some cohorts. For example, all-cause readmission was greater in the high-spending EOL quintile relative to the low-spending EOL quintile among the “fusion, except cervical” cohort (14.2% vs. 13.1%; OR = 1.10; 95% CI = 1.05 to 1.20), the “complex fusion” cohort (28.0% vs. 25.4%; OR = 1.15; 95% CI = 1.01 to 1.30), and the “cervical fusion” cohort (15.0% vs. 13.6%; OR = 1.12; 95% CI = 1.05 to 1.20).

Conclusions:

Wide variation in spending was not explained by differences in illness severity, age, or pricing, and increased discretionary care did not enhance safety. These findings point to inefficient use of health-care resources, a potential focus of reform.

Level of Evidence:

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.
Interpretation of Magnetic Anomalies over 2D Fault and Sheet-Type Mineralized Structures Using Very Fast Simulated Annealing Global Optimization: An Understanding of Uncertainty and Geological Implications
Authors: Biswas Arkoprovo , Rao Khushwant
Published: December 2021

Identification of intraterrane dislocation zones and associated mineralized bodies is of immense importance in exploration geophysics. Understanding such structures from geophysical anomalies is challenging and cumbersome. In the present study, we present a fast and competent algorithm for interpreting magnetic anomalies from such dislocation and mineralized zones. Such dislocation and mineralized zones are well explained from 2D fault and sheet-type structures. The different parameters from 2D fault and sheet-type structures such as the intensity of magnetization (k), depth to the top (z1), depth to the bottom (z2), origin location (x0), and dip angle (θ) of the fault and sheet from magnetic anomalies are interpreted. The interpretation suggests that there is uncertainty in defining the model parameters z1 and z2 for the 2D inclined fault; k, z1, and z2 for the 2D vertical fault and finite sheet-type structure; and k and z for the infinite sheet-type structure. Here, it shows a wide range of solutions depicting an equivalent model with smaller misfits. However, the final interpreted mean model is close to the actual model with the least uncertainty. Histograms and crossplots for 2D fault and sheet-type structures also reveal the same. The present algorithm is demonstrated with four theoretical models, including the effect of noises. Furthermore, the investigation of magnetic data was also applied from three field examples from intraterrane dislocation zones (Australia), deep-seated dislocation zones (India) as a 2D fault plane, and mineralized zones (Canada) as sheet-type structures. The final estimated model parameters are in good agreement with the earlier methods applied for these field examples with a priori information wherever available in the literature. However, the present method can simultaneously interpret all model parameters without a priori information.
Global Buckling Characteristics of Offshore Bundled Pipeline System
Authors: Yurindatama Danar Tri , Singh Nawin , Pillai Vinod
Published: December 2021

In recent years, the global buckling assessment of offshore pipelines in High Pressure-High Temperature (HPHT) condition become increasingly challenging since more complex pipeline system arrangement e.g. pipe(s) or cable(s) is strapped onto a larger pipeline, are rapidly utilized in many areas. Yet, the detailed guideline to assess the buckle of bundles remains unclear, therefore this study will focus to investigate on a methodical and reproducible approach to analyze in-service buckling behavior of bundled offshore pipeline system. The global buckling behavior of bundled offshore pipeline system in this study is investigated using commercial Finite Element (FE) software. Two carbon steel pipelines with different diameter are bundled and the buckling behavior is studied under the influence of buckle triggers. In the actual condition, the rogue buckle trigger is generated from OOS (out of straightness) or imperfection e.g. due to laying tolerance. Varying dimension parameter such as diameter ratio between the main pipeline and strapped pipeline are considered to understand the impact of this parameter on the buckle behavior. The study begins with a comparison of the results using numerical and analytical approaches on a straight pipeline in an unbuckled condition for validation purposes. The design parameters including wall thickness, process data, and pipe-soil interaction data, are varied since it influences the buckle behavior. In addition, some design parameter such as material properties and pipeline length will be adopted from a typical offshore pipeline project and the values are fixed so the exercise can focus on the most governing parameters. Following this, two numerical modelling methods, the equivalent properties method and the connector method, are presented in this study to simulate bundled systems. With a good agreement between the analytical and numerical approach, some buckle trigger is introduced on the numerical model of the bundled pipeline so the system is able to buckle and the behavior can be evaluated further. The strain level, lateral displacement, axial feed-in and pipe integrity shall be reported in the post-buckle conditions for both main pipe and strapped pipe as per current code and standard requirement. With more reliable results of buckling assessment for bundled pipeline system, it gives technical confidence and a major saving in both Capital Expenditure (CAPEX) and Operational Expenditure (OPEX). Industry has put serious effort through various Joint Industry Projects (JIP) to develop the global buckling assessment guideline in order to ensure long term integrity operation. Although the JIP guideline is predominantly for single pipeline system, similar assessment is demanded also for bundled pipeline system which described in this study. Key findings of the assessment are presented along with an overview of the design process and the typical mitigation techniques to be considered for similar subsea pipeline projects.
Supporting Decommissioning/Conversion of Offshore Structures Applying Innovative Technological Solution INSURE project
Authors: Speranza Davide , Vignali Andrea , Pacini Andrea , Ori Gian Gabriele , Palucci Antonio
Published: December 2021

Companies that work in the decommissioning of platforms need tools to make smarter and informed business decisions, manage and analyse business data, increase the security of workers and operate under strict environmental protection regulations. INSURE aims at assessing the feasibility of a new service to support the decommissioning of offshore installations by means of technological innovation made available throughout each process’ step.

In order to accomplish this, the project gathers high-impact Italian companies bringing together the best applicable technological and scientific know-how. INSURE foresees to combine these know-hows and create a novel tool at the service of the industry to promote a better and safer approach to the operations. Targets of the INSURE project are improving workers’ safety, enhancing environmental monitorings, increasing operations’ efficiency, reducing operational costs, offering a route for future sustainability.

Project targets can be achieved through the realisation of an augmented virtual reality platform (AVRP) that will be operated in support of the decommissioning process where the data acquired/transmitted by a plurality of sensors will converge. A fleet control tool integrates information from sensors installed on autonomous aerial and underwater vehicles making use of the Global Satellite Navigation Systems (GSNS) and Satellite Communications (SatCom). The convergence of top-notch technologies (augmented/virtual reality, 3D, robotics, sensors, 5G and Satellite services), together with a cloud of infrastructure, enables a fast and complete access to real-time data at very high resolution. The proposal aims to bring the actual data and information access from the Internet of Things to the Internet of Knowledge paradigm.

Confrontation with national and international possible end-users produced a set of user requirements guiding the design of a feasibility study for the realisation of one specific product. The study also includes the evaluation of economic, non-economic viability and possible regulatory constraints to its realisation. The INSURE feasibility study creates the intellectual background for the further step of the process: the realisation and development of a pilot project tailored for the purpose.

This combined use of novel technologies represents an innovative integrated approach applied to the management of offshore structures undergoing decommissioning or reconfiguration for other purposes. In addition, it also involves the promotion of sustainable opportunities for commercial, social and educational exploitation of areas and assets (including, for example, the ambit of eco-tourism, renewable energies, carbon capture and storage).
High-Sensitivity, Portable Online Measurement of Defects and Anomalies in Coiled Tubing Strings
Authors: Aziz Mustafa , Abdula Reyah , Al-Dujaili Mohamad
Published: December 2021

A high-sensitivity, low-power and portable coiled-tubing (CT) inspection tool is developed based on magnetic flux leakage (MFL) technology. The tool provides enhanced real-time integrity monitoring of CT operations to minimize the risks of unexpected failures and enable efficient management of CT operations. This paper discusses practical design and engineering considerations to enhance the sensitivity of the magnetic inspection head, including magnetic characterization of the CT material, pole-piece separation, parametric calculations of the gap field, eddy currents, and MFL signal bandwidth. Experimental measurements illustrate the capability of detecting defects down to 1 mm in diameter and depth in a 1.5" CT pipe.
Saliency-Map Guided Salt Prediction by a Multi-Channel Convolutional Neural Network
Authors: Jiang Fan , Norlund Phill
Published: December 2021

One of the major challenges in seismic imaging is accurately delineating subsurface salt. Since a salt boundary has strong impedance compared with other sediments, we build a saliency map with intensity and orientation to create a pixel-level model for salt interpretation. In this abstract, we train a saliency-map as an additional attribute to combine with the original seismic to predict salt bodies. We also train a saliency-map to classify multiple geological facies in a multi-channel convolutional neural network with residual net architecture to help build subsurface velocity models. Two examples are shown which demonstrate that a saliency-map-plus-seismic model successfully improves the accuracy of salt prediction and reduces artifacts.
Development and First Application of an Ultra-Low Density Non-Aqueous Reservoir Drilling Fluid in the United Arab Emirates: A Viable Technical Solution to Drill Maximum Reservoir Contact Wells Across Depleted Reservoirs
Authors: Jeughale Ramanujan , Andrews Kerron , Al Ali Salim Abdalla , Toki Takahiro , Tanaka Hisaya , Sato Ryosuke , Luzardo Juan , Sarap Girish , Chatterjee Saumit , Meki Zakaria
Published: December 2021

Drilling and completion operations in depleted reservoirs, are challenging due to narrow margin between pore and fracture pressures. Therefore, Ultra-Low Density Reservoir Drilling Fluid (RDF) with optimum parameters is required to drill these wells safely. Design and effective field application of a sound engineered fluid solution to fulfill these operational demands are described.

Ultra-Low Density RDF NAF with minimal fluid invasion characteristics was developed after extensive lab testing, to cover the fluid density from 7.2 – 8.0 ppg. The fluid properties were optimized based on reservoir requirements and challenging bottom-hole conditions. The design criteria benchmarks and field application details are presented. Fluids were stress tested for drill solids, reservoir water and density increase contamination. Multi-segment collaboration and teamwork were key during job planning and on-site job execution, to achieve operational success.

For the first time in UAE, a major Offshore Operator successfully applied an Ultra-Low Density RDF-NAF, which provided remarkable stability and performance. The fluid was tested in the lab with polymeric viscosifier alone and in combination with organophilic clay. In order to gain rheology during the initial mixing, about 3.0 ppb of organophilic clay were introduced to system along with the polymeric viscosifier. Later, all the new fluid batches were built with polymeric additives alone to achieve target properties. A total of 10,250 ft of 8 ½" horizontal section was drilled to section TD with record ROP compared to previous wells in the same field, with no fluids related complications. With limited support from the solid control equipment, the team managed to keep the density ranging from 7.5 ppg to 7.8 ppg at surface condition, using premixed dilution.

Bridging was monitored through actual testing on location and successfully maintained the target PSD values throughout the section by splitting the flow on three shaker screen size combination. Due to non-operation related issues, hole was kept static for 20 days. After such long static time, 8 ½" drilling BHA was run to bottom smoothly precautionary breaking circulation every 5 stands. Finally, after successful logging operation, 6 5/8" LEL liner was set to TD and the well completed as planned.

Success of this field application indicates that an Ultra-Low density fluid can be designed, run successfully and deliver exemplary performance. Lessons learned are compared with conceptual design for future optimization. Laboratory test results are presented, which formed the basis of a seamless planned field application.
Improving Operational Efficiency Using Automated Time Analysis for Multi-Well Pad Fracturing
Authors: Siddiqui Fahd , Kamyab Mohammadreza , Lowder Michael
Published: December 2021

The economic success of unconventional reservoirs relies on driving down completion costs. Manually measuring the operational efficiency for a multi-well pad can be error-prone and time-prohibitive. Complete automation of this analysis can provide an effortless real-time insight to completion engineers. This study presents a real-time method for measuring the time spent on each completion activity, thereby enabling the identification and potential cost reduction avenues.

Two data acquisition boxes are utilized at the completion site to transmit both the fracturing and wireline data in real-time to a cloud server. A data processing algorithm is described to determine the start and end of these two operations for each stage of every well on the pad. The described method then determines other activity intervals (fracturing swap-over, wireline swap-over, and waiting on offset wells) based on the relationship between the fracturing and wireline segments of all the wells. The processed data results can be viewed in real-time on mobile or computers connected to the cloud.

Viewing the full operational time log in real-time helps engineers analyze the whole operation and determine key performance indicators (KPIs) such as the number of fractured stages per day, pumping percentage, average fracture, and wireline swap-over durations for a given time period. In addition, the performance of the day and night crews can be evaluated.

By plotting a comparison of KPIs for wireline and fracturing times, trends can be readily identified for improving operational efficiency. Practices from best-performing stages can be adopted to reduce non-pumping times. This helps operators save time and money to optimize for more efficient operations. As the number of wells increases, the complexity of manual generation of time-log increases. The presented method can handle multi-well fracturing and wireline operations without such difficulty and in real-time.

A case study is also presented, where an operator in the US Permian basin used this method in real-time to view and optimize zipper operations. Analysis indicated that the time spent on the swap over activities could be reduced. This operator set a realistic goal of reducing 10 minutes per swap-over interval. Within one pad, the goal was reached utilizing this method, resulting in reducing 15 hours from the total pad time.

The presented method provides an automated overview of fracturing operations. Based on the analysis, timely decisions can be made to reduce operational costs. Moreover, because this method is automated, it is not limited to single well operations but can handle multi-well pad completion designs that are commonplace in unconventionals.