bluuebunny/crossref_metadata_2025 huggingface dataset:
HPLC Analysis of Phenolic Compounds and Flavonoids with Overlapping Peaks
Authors: Mizzi Luke , Chatzitzika Christina , Gatt Ruben , Valdramidis Vasilis
Published: February 2020

The identification and quantification of phenolic compounds and flavonoids in various natural food products is typically conducted using HPLC analysis. Their analysis is particularly complex since most natural food products contain a large number of different phenolic compounds, many of which have similar chemical characteristics such as polarity, which makes complete separation of all eluents extremely difficult. In this work we present and validate a method for the quantitative determination of the concentration of two compounds with similar retention times, i.e. they show overlapping peaks in a mixed solution. Two pairs of phenolic compounds were investigated: caffeic and vanillic acids and ferulic and p-coumaric acids. This technique takes advantage of the different absorbances of the two phenolic compounds in the eluent at various wavelengths and can be used for the quantitative determination of the concentration of these compounds even if they are not separated in the HPLC column. The presented method could be used to interpret the results of HPLC analysis of food products which possess a vast spectrum of phenolic compounds and flavonoids.
Exploring Language Learning Motivation among Primary EFL Learners
Authors: Wallace Matthew P. , Leong Emily In Leng
Published: February 2020

The present study examined factors contributing to motivation of young EFL learners. Specifically, it explored learners’ attitudes and purposes for studying English, and how their perceptions of social support (teacher, family, peers) and that of the formal learning environment (learning tasks and class activities) varied at different levels of motivation. In total, 23 grade six students who studied at a Macau primary school completed a 10-item open-ended questionnaire. Findings revealed that most of the participants were highly motivated and learned English for both instrumental (e.g., for work and travel) and integrative (e.g., wanting to integrate within the target language culture) reasons. Most respondents reported that they viewed their teachers positively, which may explain why most of them also had a positive view of studying English despite indicating that their family expected them to get high grades on exams, and that most of their classmates perceived studying English negatively. Unsurprisingly, participants also reported that games and songs were their favored activities because they increased their intrinsic motivation to learn. The results of this study suggest that young learner motivation may be largely influenced by the learning environment (as opposed to family or peer social relationships), notably the positive relationship with the teacher and the types of learning activities employed to achieve learning aims.
O avanço da sojicultura no nordeste brasileiro: reflexões iniciais sobre a região da SEALBA
Authors: Santos Flávio dos , Campos Christiane Senhorinha Soares
Published: February 2020

RESUMO: O artigo tem como propósito realizar uma reflexão sobre o projeto de implantação da sojicultura em uma área de terras contíguas localizada nos estados de Sergipe, Alagoas e Bahia, que recebeu o nome de SEALBA, acrônimo das siglas destes três estados, respectivamente. Este recorte territorial vem sendo apontado como possuidor de um grande potencial agrícola para o cultivo da soja. Alicerçados na análise dos dados da EMBRAPA Soja, EMBRAPA Tabuleiros Costeiros e do Censo Agropecuário IBGE (2017), bem como ancorados em uma reflexão teórica pautada no debate dos processos de mundialização do capital e modernização da agricultura, busca-se analisar os objetivos do agronegócio no que tange à implantação do cultivo da soja na região da SEALBA, com ênfase no contexto alagoano, a fim de desvelar os nocivos impactos socioambientais que podem engendrar.     

PALAVRAS-CHAVE: Soja, Agronegócio, Alagoas.
A violência de gênero no Brasil numa perspectiva da Broken Windows Theory
Authors: Silva Lúcio Luiz Izidro da , Souza Jane Felipe de
Published: February 2020

O presente artigo científico tem como objetivo precípuo cotejar a violência de gênero no Brasil numa perspectiva da broken windows theory. Para tanto buscaremos apoio nos mapas da violência no Brasil apresentados por agência especializada em monitorar as estatísticas anuais. Num primeiro momento abordaremos questões conceituais sobre a “teoria das janelas quebradas”. Em seguida apresentaremos os índices da violência de gênero. Por fim enlaçaremos os números objetivos da violência com os argumentos teóricos. O trabalho, portanto, parte de uma metodologia experimental e uma revisão bibliográfica para dar suporte ao aviamento estrutural. O tema é relevante, pois os números estudados têm sido constantemente debatidos nas principais agendas de combate a violência, sobretudo de gênero.
Educação especial e ser deficiente: reflexões em torno de uma inclusão excludente
Authors: Sandres Carolina Sena do Vale , Silva Cristiano Cezar Gomes da , Almeida Maiara Cristine Oliveira de
Published: February 2020

RESUMO: Este trabalho busca discutir aspectos da educação especial a partir da discussão acerca da inclusão e do estereótipo do sujeito com deficiência, visando refletir como isso implica na construção de sujeitos na contemporaneidade e a inserção do diferente na sociedade. Ao problematizar conceitos relacionadas com a construção de identidades e diferenças na deficiência podemos compreender como as práticas escolares de inclusão estão sendo construídas. Para isso, utilizaremos autores como Bhabha (1998), Benedict (2000), Freud (1921), Hall(2000), Mrech (1999), Vasques (2007) e Veiga-Neto e Lopes (2007) como teóricos que fundamentaram as propostas e reflexões apresentadas neste trabalho. A construção do mesmo se deu a partir de uma pesquisa de cunho teórico, onde a perspectiva dos estudos culturais foi utilizada como subsídio que sustentam a discussão proposta neste trabalho. Discutir os processos inclusivos pensando nessa perspectiva permite que a sociedade possa compreender como identidade na pessoa com deficiência pode ser pensado como uma construção cultural, a partir das diferenças, sendo construída por vários, produzidas nos entrelugares, saindo de um contexto de estereótipos que reforçam e apagam as diferenças nos processos inclusivos.

PALAVRAS-CHAVE: Educação especial. Inclusão. Identidade. Diferença. Estereótipo.
Polymeric Microparticles as Alternative Carriers for Antidiabetic Glibenclamide Drug
Authors: Siafaka Panoraia I. , Cağlar Emre Şefik , Papadopoulou Katerina , Tsanaktsis Vasilios , Karantas Ioannis D. , Okur Neslihan Üstündağ , Karasulu Hatice Yeşim
Published: February 2020

Background: Glibenclamide is a lipophilic drug widely used in type 2 diabetes treatment. However, its low bioavailability limits its use. Thus, novel formulations should be applied to improve the drug’s bioavailability.
Objectives: This study aimed to develop alternative carriers for oral delivery of glibenclamide. For this purpose, two biocompatible polymers, poly(e-caprolactone) and poly(butylene adipate) were formulated as microparticles (MPs) capable of loading the antidiabetic drug.
Methods: In this regard, as microparticle fabrication approach, the modified emulsion solvent evaporation method was applied. Physicochemical evaluation of the prepared microparticles included the examination of their morphology, degradation rate, and thermal properties. Drug entrapment, drug loading, and particle size were also investigated. Simulated intestinal medium and body fluid at 37oC were selected as dissolution media. Differential scanning calorimetry was used to investigate the crystal properties of the microparticles and drugs.
Results: The developed microparticles had sizes between 0.5 and 4 μm. Poly(butylene adipate) based microparticles had a smooth surface, whereas poly(ε-caprolactone) based microparticles showed a porous surface. The DSC thermogram revealed the amorphization of the drug. Hydrolysis results exhibited a very low mass loss, while in vitro release results depicted that the dissolution rate of the prepared microparticles was higher than that of pure glibenclamide demonstrating a prolonged pattern which is ideal for minimizing the daily dose of glibenclamide.
Conclusion: In this study, novel carriers for glibenclamide were successfully prepared with promising future use.
Narrativas de sostenibilidad en emprendedores sociales de Lima Metropolitana
Authors: Vera Ruiz Angela , Prialé Valle María Ángela , Pezzia Agustín , Ninahuanca López Erle Frances
Published: February 2020

El aprecio por prácticas sostenibles resulta una dimensión psicológica fundamental y articuladora en el actuar de los emprendedores sociales. Se refiere a una conciencia crítica de interconexión y pensamiento sistémico, lo que resulta en prácticas emprendedoras responsables en beneficio de la sociedad y el mundo. El presente estudio busca comprender la manera en que esta dimensión se gesta y hace consistente en las narrativas de vida de líderes de emprendimientos sociales de Lima Metropolitana. Los resultados permitirían un mayor conocimiento del constructo y un mayor fundamento para pensar en el desarrollo del mismo. A través de una metodología cualitativa de diseño narrativo, se encontraron dos grandes narrativas: la Autotrascendencia social y las Prácticas sostenibles.
A practical explanation of ethics as a good corporate governance principle in South Africa and New Zealand – A case study
Authors: Killian Cornelius
Published: February 2020

This article uses two case law examples (New Zealand and South Africa), to illustrate how a questionnaire could be developed in practice as a method to identify a breach of ethics with reference to King IV, the FMA handbook and the NZX code. These two cases use terminology as found in relevant corporate governance codes and illustrate how to interpret those terminologies correctly, i.e. in terms of honesty and integrity. Relevant literature is reviewed in reference to the two case law examples. To interpret a corporate governance term properly, reference should also be made to appropriate legislation, e.g., the Companies Act when drafting a questionnaire. To understand corporate governance codes a holistic view should be adopted by the board of directors when drafting a corporate governance questionnaire. Such a questionnaire could provide the necessary insight as a method to prevent unethical business behaviour in future.
PENDIDIKAN AGAMA ISLAM PADA ANAK USIA SEKOLAH DASAR DALAM KELUARGA DI KECAMATAN PEMANGKAT KABUPATEN SAMBAS
Authors: Wasli Rianawati,
Published: February 2020

Family roles have a huge influence on child education. The roles of each parent must complement each other, so that harmonization in the family can be realized through religious values in daily life. Family become the first place for education for a child, so the Islamic education in the family is very important because it will shape the child's personality. This study used a qualitative descriptive research method, so the results of this research were narrated in the form of descriptions. The data were gathered through observation and interviews where the major respondents were parents in Pemangkat. The data from the interview were analysed simultaneously, so that the data verification was also done simultaneously. The findings of this study revealed that the first religious education for the child was in the form of teaching things that are easy to understand, e.g. pronouncing asthma Allah, becoming close friends with them, forming good habit, encouraging the children to seek science by studying in the mosques. The widespread religious understanding in the family was later found in Pemangkat that Islamic educational materials were taught to children such as educational beliefs, religious education, moral education, primary teaching of Islamic education and reading the Qur'an. In Pemangkat, it was found that Islamic education in the family must pay attention to the Islamic faith, where faith is the essence of the foundation of faith one must be given to the child from an early age. In educating the children, the parents provided materials about religion to children that is by using the method of storytelling, by giving examples, experiences and punishment.
Pengaruh Durasi Iskemia terhadap Ekspresi Protein P53 Otak Tikus Pasca Transient Bilateral Common Carotid Artery Occlusion (TBCCAO)
Authors: Handayani Ety Sari , Kuswati Kuswati , Sabta Nugaha Zainuri , Hidayah Nurul , Herennadia Nesti , Sonia Amanda Gea , Ajeng Salsabila
Published: February 2020

Tumor suppressor gene p53 is one of the specific parameters of the occurrence of brain neuron death in animal models of brain ischemia. Several studies show that the duration of reperfusion of tBCCAO has an effect on the expression of p53 protein. The duration of ischemia for 5 minutes followed by reperfusion of 1 hour, 4 hours, 8 hours, 24 hours, and 7 days increased the expression of p53 protein. 30-minute ischemia induction followed by 4-hour reperfusion showed increased p53 protein expression in rat serum. It is not yet known how the influence of tBCCAO ischemia duration on p53 expression in rat brain. This study used Wistar, male rats, aged 3-4 months, weighing 175-250 gr, and healthy. Group A was a group of tBCCAO rats with a duration of 5 minutes ischemia, 24-hour reperfusion duration (five). Group B was a group of tBCCAO mice with a duration of 10 minutes ischemia, 24-hour reperfusion (five). Group C is a group of sham operated mice (five). The expression of p53 protein is semi quantification of p53 expressed on pyramidal neuron of the frontal brain (Cortex Prefrontalis, striatum) and CA1 hippocampus, with IHC staining using anti-p53 antibodies. P53 expression will be seen in the cytoplasm of pyramidal neuron CA1 hippocampus. Cytoplasm of neurons will be brownish in color. The semi-quantification method of p53 expression uses the ALLRED score. Data analysis using one way ANOVA test. The analysis found differences in frontal brain p53 expression (cortex prefrontalis and striatum) (p = 0.00) and there were differences in p53 expression in pyramidal neuron CA1 hippocampal (p = 0.013). There was an effect of the duration of tBCCAO on expression of p53 protein in rat brain after 24-hour reperfusion. Keywords: tBCCAO’s duration, p53, rat’s brain
Survey of Social Touch Interaction Between Humans and Robots
Authors: Shiomi Masahiro , Sumioka Hidenobu , Ishiguro Hiroshi ,   Advanced Telecommunications Research Institute International (ATR) 2-2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0288, Japan,   Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
Published: February 2020

In human-human interaction, social touch provides several merits, from both physical and mental perspectives. The physical existence of robots helps them reproduce human-like social touch, during their interaction with people. Such social touch shows positive effects, similar to those observed in human-human interaction. Therefore, social touch is a growing research topic in the field of human-robot interaction. This survey provides an overview of the work conducted so far on this topic.
Impending Atypical Femur Fracture Presenting as Painful Total Knee Arthroplasty
Authors: Andrews Kyle A. , Wynkoop Emily I. , Stokey Phillip J. , Georgiadis Gregory M.
Published: February 2020

Case:

We report on 2 patients with atypical femur fractures that initially presented as painful total knee arthroplasties. There was a history of long-term bisphosphonate use in each case. Knee radiographs and laboratory studies were normal, and the patients were managed conservatively. Both subsequently sustained atypical femur fractures and underwent surgical stabilization.

Conclusions:

Referred pain from a bisphosphonate-related femoral stress fracture can masquerade as pain about a total knee arthroplasty. This should be included in the differential diagnosis in at-risk patients because it can result in an atypical femoral shaft fracture above the prosthesis if not properly treated.
Pembuatan dan Digitalisasi Batik Tulis Madura Pada UKM Batik Bangkalan
Authors: Siradjuddin Indah Agustien , Sophan Kautsar , Kurniawati Arik , Triwahyuningrum Rima
Published: February 2020

Batik Madura dikenal akan jenis batik tulis Madura yang memiliki motif batik dan warna batik yang unik. Keseluruhan produksi batik tulis Madura ini dilakukan secara manual, mulai dari desain batik, menggambar batik pada kain, mencanting, fiksasi, pewarnaan, dan lain-lain. Proses manual inilah yang tetap menjaga keaslian batik tulis Madura. Hanya saja, kain batik yang dihasilkan pada batik tulis Madura ini, tidak menghasilkan pola yang simetris ketika kain batik dibuat menjadi sebuah pakaian. Motif-motif yang terdapat pada pakaian yang berasal dari kain batik tulis Madura, tidak membentuk pola yang simetris. Oleh karena itu diperlukan upaya agar motif-motif yang dibuat oleh pengrajin batik, dapat membentuk pola simetris pada suatu pakaian. Kegiatan pengabdian yang diusulkan adalah pembuatan motif batik tulis Madura, agar pakaian yang dihasilkan menampilkan pola simetris, dengan bantuan perangkat lunak. Tahap pertama yang dilakukan adalah pembuatan mal atau template pakaian yang akan dibuat, penyusunan mal ini pada desain kain batik, penyusunan motif-motif batik pada kain sehingga sesuai dengan mal pakaian yang telah ada.
Laboratory Study of Effect of Overburden, Formation and Mud Column Pressures on Drilling Rate of Permeable Formations
Authors: Cunningham R.A. , Eenink J.G.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 217, 1959, pages 9–17.

One phase has been completed of a laboratory investigation of formations with relatively high permeability under conditions of overburden, formation and mud column pressures. The following statements are based on these tests within the limitations described.

Drilling rate decreased when mud column pressure was greater than formation pressure. The decrease was primarily due to a layer of cuttings and mud particles held to the hole bottom by the difference in pressure. Much of the force of the bit was wasted in this layer and was unavailable for penetrating virgin formation.

Adequate jet velocities helped clean the filter cake and chips away and resulted in increased drilling rate the higher the jet velocity the faster the drilling rate.

Drilling rate increased slightly when formation pressure was greater than mud column pressure. The increase resulted from cleaning the hole bottom as formation fluid flowed into the borehole.

Overburden pressure had practically no effect on drilling rate.

Introduction

Some formations are difficult to drill in a wellbore hole but are easily drilled under atmospheric conditions in the laboratory. The reasons for this apparent difference in drill ability are not fully understood.

An increase in formation compressive strength causes a reduction in drilling rate. It has been shown by Griggs, Handin, and others that formation strength increases under conditions of high hydrostatic stress. Based on these results, a decrease in drilling rate would be expected with increased drilling fluid pressure in formations of low permeability having low formation fluid pressure. Such a decrease has been shown by Murray, et al and Eckel. This effect holds even when using nitrogen under high pressure as the drilling fluid (unreported tests from the Hughes laboratory).

Poor bottom-hole cleaning may account for decreased drilling rates. Even though it may not be easily explained, evidence of poor cleaning can easily be seen.
Thermal Effect on Fracture Width for Wellbore Strengthening Applications
Authors: Yao Ziheng , Alberty Mark
Published: February 2020

Most wellbore strengthening (WBS) techniques require an understanding of the width on an induced fracture to design the size and concentration of appropriate mud additives to mitigate the fracture growth. Current methods to estimate fracture width primarily consider stress and rock properties but neglect the effect of the thermal contrast between the drilling fluid and the formation. This paper reports the results of the modeling of the thermal effect on fracture width and proposes a practical method to integrate the thermal effect into current WBS design workflows.

The proposed process uses both analytical and numerical methods to investigate the thermal effect. A finite element analysis (FEA) model simulates the coupled stress and temperature field around the borehole, which allows the width of the fracture to be derived at any point along the length. The Abaqus FEA model uses 2-D plane strain elements to allow either steady-state or transient thermal-mechanical analysis. The results of FEA modeling are compared to the semi-analytical solution which only addresses the mechanical effect. Both models use field data to verify and validate results.

An equivalent tensile stress is used to derive an analytical solution for fracture width for the case of ‘long-term’ cooling. The results provide a good match to the steady-state thermal elastic FEA results. In the case of transient heat transfer, an approximate analytical solution is derived to describe temperature distribution around the borehole as function of time. Then the analytical solution for thermal stresses is derived based on intact circular borehole. The analytical results are compared and verified with the FEA. Currently, the fracture width in response to a transient thermal event can only be calculated using the FEA model. The change in fracture width due to the temperature disturbance can be superimposed over the elastic fracture width to provide a more accurate estimate of width due to both mechanical and thermal influences for planning WBS formulations. The model demonstrates that the cooling of the borehole with drilling mud results in a wider fracture than that which is predicted by the purely elastic models. If drilling mud temperature is not considered or managed effectively, the failure of the WBS application could result, leading to a lost circulation event. A field case where wellbore cooling occurs and leads to lost circulation is presented.
World's First Hybrid Drilling Rig
Authors: Bilgin Memet , Donen Joel , Scaini Vince , Snijder Marcel
Published: February 2020

The world's first hybrid drilling rig began commercial operations on July 1st, 2018. Significant fuel savings and emissions reductions were achieved by implementing a hybrid Energy Management System (hEMS).

The hEMS uses battery energy storage and engine automation to reduce the number of gensets operating and increase the average efficiency of each genset. The key to achieving fuel savings was to integrate the controls of the hEMS with the drilling rig's controls system. By doing so, gensets are automatically turned on or off depending on the power demand of the rig and the state of charge of the battery.

In addition to fuel savings, downtime due to issues with generators was avoided. The battery energy storage provided power when a genset faulted or needed immediate servicing. Furthermore, monitoring genset performance, diesel fuel flow, field gas fuel flow when available, and overall rig electrical bus activity enabled prediction of potential blackouts and helped technicians target preventative maintenance.

The system was developed over two years and tested at a rig construction facility before being placed into operation on a rig working in the Marcellus Shale. This paper describes the technology and presents the results achieved to date with regards to measuring fuel savings, lowering emissions, reducing genset runtime hours, and avoiding power-related downtime.
Accurate Determination of Annular Content Behind Casing and Prevention of Remedial Action During Well Construction
Authors: Govil Amit , Kalyanraman Ram Sunder , Constable Kevin
Published: February 2020

As oil and gas fields mature, many wells are scheduled for permanent well abandonment or permanent abandonment of a section for subsequent slot recovery. We present a novel data interpretation workflow that integrates pulse-echo inversion to accurately predict borehole fluid properties and sonic attenuation with ultrasonic measurement to accurately define the annular material present behind the casing.

Per the NORSOK D-010 standard, the requirement to qualify a well section for further drilling is to evaluate any degradation of the main bore casing, along with evaluation of the well barrier element. In an example slot recovery well, pulse-echo measurement and a cement bond log were recorded in the main borehole. The data was interpreted using an industry-available cement evaluation workflow to indicate the presence of very low impedance material (gas column) between two casings up to surface. The presence of a gas column required remedial action to mitigate well integrity issues during well construction. Advanced cement interpretation was conducted using a newly developed workflow that integrates new pulse-echo inversion and sonic attenuation measurement. The novel pulse-echo inversion accurately determines azimuthal as well as depth variations in the acoustic impedance of the borehole mud. The inversion is validated using 3D models without prior knowledge of mud properties. With the help of in situ measurement of mud properties, we can now visualize features such as mud deposition and segregation in deviated pipes as well. This new processing enables easier and more accurate interpretation of the cement sheath together with providing essential information about the logging fluid. The obtained results clearly identified the presence of solids and liquids in the annular space, which helped the operator to make informed decisions for continued slot recovery and new well drilling operations, rather than spending rig time on gas column mitigation measures. Advanced cement evaluation measurement and interpretation techniques reduce risks and enable accurate and critical decision making for well construction, intervention, and plugging and abandonment in many conditions that were previously ambiguous.

Novel three-parameter inversion for pulse-echo measurements delivers unmatched accuracy for identifying the annulus material, as well as critical information on the logging mud, leading to a high level of confidence on cement placement. This aspect is especially critical in ensuring correct evaluation in complex new well designs including vertical, deviated, or horizontal pipes with a variety of mud types.
Validating Ultrasonic Log Response Against Reference Barrier Cells Simulating Downhole Well Conditions Encountered During Well Construction and Abandonment Operations
Authors: Govil Amit , Gardner Dave , Obando Guillermo , Beltrán-Jiménez Katherine , Skadsem Hans Joakim
Published: February 2020

In the design of oil and gas well barriers, the quality of the cemented casing must be assessed to optimize the cost of the operation. Borehole cement evaluation logs are used to verify the quality of the cement bond to the casing and formation and identify any defects that could compromise the quality of the annular seal. This study used ultrasonic logging to evaluate reference barrier cells constructed with known defects. In this joint project between industry representatives and a research institute, reference barrier cells were created to simulate downhole oil well conditions, such as free/cemented pipe, sagged barite, gas environment, mud channel, microannulus, axial hole, and cemented control line. The cell concept was developed with an emphasis on low cost and ease of use. Different cell configurations could be quickly coupled to provide the required tool lengths and measurement points for logging experiments. The tubing and annulus pressures (maximum 150 bar) and fluids can be varied according to the test requirement.

Each reference cell was constructed to highlight a condition that is typically encountered in an oil well. Full-scale logging was carried out in which multiple reference cells were coupled vertically on a drilling rig. Data were acquired at multiple resolutions, while applying pressure (0, 100, and 150 bar) to the outer annulus, thereby varying microannulus size. Data from the pulse echo and flexural sensors provided a detailed image highlighting the condition of the bond behind the inner casing. Laboratory experiments were performed to characterize the reference cells, including measurements of strain and infrared thermography to visualize the leakage paths. The log response was found to be consistent with the physical observation and laboratory experiments.

During the cement evaluation of a tubular casing, interpretation is made based on log response under certain well conditions. Inferences are based on fundamental sensor physics, laboratory experiments, common knowledge, and contemporary understanding of the technology. Comparison of ultrasonic tool response against reference barrier cells validates the measurements, which are crucial in the decision-making process during well construction and abandonment. The paper describes the full-scale test performed at the research institute, including the laboratory experiments and log data acquired.
Modeling Cuttings Transport and Annular Pack-Off Using Local Fluid Velocities with the Effects of Drillstring Rotation and Eccentricity
Authors: Erge Oney , van Oort Eric
Published: February 2020

One of the primary functions of the drilling fluid is to transport cuttings from the bit to the surface. This transport is mainly a function of fluid properties (rheology and density), pump rate, wellbore trajectory and geometry, drillstring rotation and eccentricity. Because these interrelated parameters all have a significant effect on cuttings transport, it is important that hole cleaning modeling is comprehensive and inclusive to yield useful, reliable results. Inaccurate models that either do not consider significant effects or oversimplify them can lead to inadequate hole cleaning advice, resulting in non-productive and invisible lost time.

A novel cuttings transport model that includes relevant effects such as pipe rotation, eccentricity and the annular blockage is presented. Local velocity profiles are calculated for a given fluid and compared against the local critical velocity for cuttings transport. Then, the location and the magnitude of annulus blockage are numerically assessed. After an annulus becomes partially blocked with cuttings deposited in a cuttings bed, continuity and momentum equations are solved for the blocked annulus to estimate the new local velocities. The annulus is divided into small sections and the pressure profile is calculated with the progression of time. By doing so, a realistic representation of a wellbore's pressure and velocity profiles is obtained.

The results from this study are in very good agreement with large-scale flow loop experiments and field observations, e.g. showing that axial flow alone is not enough for effective hole cleaning in high deviation and horizontal wells. The simulations show that in such wells the cuttings tend to deposit even at elevated axial flow rates without pipe rotation in a fully eccentric annulus, due to a significantly reduced flow rate where the drillstring is close to the borehole or previous casing string. The results also provided a way to predict "pack-off" events, when the string can become stuck, the equivalent circulating density can spike, and lost circulation can occur. The non-uniform settling of the cuttings along the wellbore will cause non-uniform distribution of pressure losses, with local pressure spikes when cuttings blockage becomes substantial. A pack-off sensitivity analysis is presented in this work. The overall aim of this work is to provide more comprehensive cuttings transport modeling for the industry to conduct safe and improved hole cleaning operations.
Will the 2020's be Known as the 20K Decade? The 20K Subsea BOP is Here
Authors: Cowan Robert "Bob" , Ellens Jonathan , Hunter Wesley , Kulkarni Ajay , Scherm Kevin
Published: February 2020

The subsea blowout preventer (BOP) is one of the primary technologies that has enabled the oil and gas industry to discover and develop deeper and more complex wells offshore. Since the invention of the first ram-type BOP in the 1920s, ever-developing BOP technology has expanded the boundaries of a safe drilling environment. New learnings derived from historical usage and advances in material science have been applied as we continue to push the envelope further. The 1980s saw a leap in offshore technology as 15,000psi (15K) BOPs hit the market. For nearly 40 years, 15K has been the limit. In the early 2010s, discoveries in the Gulf of Mexico (GoM) were being made that suggested a need for 20,000psi (20K) subsea BOPs. A handful of companies have spent the rest of the decade pursuing a cost-effective and technically-capable 20K subsea BOP solution, while regulatory bodies have debated the safe implementation of this step-change. The year 2020 will mark the point in time a fully qualified 20K subsea BOP becomes available to the industry. As a result, the 2020s may very well become known as the decade 20K assets became feasible, opening up a whole new set of opportunities for oil companies around the world.

The leap from 15K to 20K was far more challenging than the leap from 10K to 15K that the industry made in 1980s. Nearly everything had to change. Not just the technology, but even the way companies work together. This paper explains the challenge of the 20K leap, provides a summary of the design and testing that has gone into developing the industry's first fully qualified subsea 20K subsea BOP, and discusses how 20K has changed the way operators, contractors, and original equipment manufacturers (OEMs) work together.
Connection Fatigue Modeling with Large IDs: How Large of an ID Can Support a SRG?
Authors: Pettit Grant , Lee Kang
Published: February 2020

Drilling specialty tools and accessories are often machined with large Inside Diameters (IDs) so that the necessary electronic packages can fit within the component. As the ID of the component increases, the wall thickness of the pin connection is reduced. It has been established that the machining of a Stress Relief Groove (SRG) on the pin connection with a standard-sized ID will greatly improve the fatigue performance of that connection. However, no such consensus has been reached regarding the machining of SRGs on the pin connections of these special-purpose tools with large IDs.

The common concern is that the wall thickness of the pin connection has been reduced so much by the large ID that the machining of a SRG would drastically deteriorate the performance of the connection. This paper addresses that concern by providing in-depth analysis of various API connection sizes tested over a broad range of IDs. Finite Element Analysis (FEA) was used to quantify the difference in fatigue life between connections with stress relief features versus without stress relief features. Additionally, calculations were performed to understand the reduction in the capacity of the connection that results due to machining stress relief features.

This paper gives the comparative fatigue life for each of the connections modeled where the API recommended Make-Up Torque (MUT) is adjusted to compensate for the increasing ID of the connection. In every case, the benefits of machining SRGs on large ID connections are significant. Allowing larger IDs in connections where SRGs are required will bring the technical benefit of allowing larger electronics packages to fit within the bore and increased hydraulic performance, among other benefits. Additionally, the drawbacks to SRGs are considered and quantified whenever possible. Possible solutions to these drawbacks are proposed as a way to lessen their effects so the full benefit of cutting the SRGs can be realized.

In total, by looking at the potential gain in fatigue life against the trade off in lost capacity, this paper provides operators with the ability to determine the suitability of stress relief features on their components with large IDs. For those connections where a SRG is required, this paper provides guidance as to the connection's performance at various large IDs.
Prescriptive Data Analytics to Optimize Casing Exits
Authors: Popp Timothy , Shirangi Mehrdad G , Nipen Ole Petter , Berggreen Anders
Published: February 2020

Whipstock casing exits are a milling operation that enable operators to sidetrack from a primary wellbore. This paper describes a prescriptive data analytics workflow that was developed and applied to optimize casing exit applications. This workflow involves three major steps:

Pre-processing data to cleanse, transform, and aggregate data from past casing exit jobs Building accurate machine learning models to predict milling performance Optimizing a weighted objective function into recommend best-case operational parameters.

In collaboration with a North Sea operator, a downhole measurement-while-drilling (MWD) system was used in multiple wells during casing exit jobs to collect a rich data set of downhole measurements. Through a stringent data processing and modeling methodology, prescriptive models were developed and tested in an offset well in the North Sea. Success of the offset casing exit job resulted in greater than a 30-percent reduction in vibration, a 14-percent increase in rate-of-penetration (ROP), and a 23-percent reduction in average mill time.
Theoretical Vs. Actual Mud Motor Performance in Unconventional Formations and Strategies to Extend Motor Life
Authors: El-sayed Ibrahim , Hopkins Zachary , Dupriest Fred , Noynaert Samuel F.
Published: February 2020

The continued growth in unconventional drilling has resulted in downhole motors being pushed to drill more complex geometries faster, often higher downhole temperatures. This has resulted in increased rates of failure for downhole motors. The most common method to postpone motor failure has been to select a larger motor. This option ignores the root causes of motor failure and is shown to actually not improve failure rates. Impetus for this work centered on an operator who was experiencing high rates of motor failure, however in the process of investigating the failures, important findings were made that apply to any BHA with a motor.

Damage occurs in all motors in the data set, regardless of whether or not they are considered "failed." This points to a potential, unrecognized industry-wide issue wherein motor performance may be degrading over a run and is not recognized by operations teams. The result is a version of "hidden NPT" which is limiting drilling performance in wells drilled with downhole motors. Calculating the RPM factors on the operator's wells using actual motor speeds measured by downhole sensors show that motor degradation is a significant problem, resulting in a reduction of up to 40% in bit RPM.

In order to measure performance, motor properties are used to convert the traditional surface MSE measurement into a more representative downhole MSE. Further refinement of this metric was tested as downhole MSE is calculated using a simple factor and a more exact but complicated multi-dimensional correlation. Drilling data is used to show that the simplicity of the simple factor more than offsets minor loses in MSE accuracy. As noted, the real time RPM factors are also computed using downhole data showing the stark differences between the actual factors and the originally reported factors. The difference is used to determine the degree of motor damage while drilling.

A suite of downhole sensors was placed above and below the motor to monitor the rate of motor damage. Differential pressure was also analyzed in the frequency domain spectrum to demonstrate the damaging effect of bottom hole assembly (BHA) whirl during rotating.

The use of depth of cut control (DOCC) is analyzed as a method to improve motor efficiency and decrease damage. Two identical wells and BHA's are compared, one with and one without DOCC. The uses of the first derivative of differential pressure is suggested as a method to better quantify and visualize the effects of DOCC. Ultimately, the research presented provides quantitative insights into the operation of a motor, and shows that motor performance is not as expected based specification sheet values.
Experimental Study on Injection Pressure Response and Fracture Geometry during Temporary Plugging and Diverting Fracturing
Authors: Wang Bo , Zhou Fujian , Yang Chen , Wang Daobing , Yang Kai , Liang Tianbo
Published: February 2020

Temporary plugging and diverting fracturing (TPDF) has become one of the fastest-growing techniques to maximize the stimulated reservoir volume (SRV). During the field operation of TPDF, diverters are injected to redirect the hydraulic fractures into the under-stimulated region of the reservoir, and, thus, to obtain better coverage of the created fracture network. In this study, the commonly used true tri-axial hydraulic fracturing system is modified to investigate the influences of various factors on the injection pressure response and resultant fracture geometry during diversion treatments. The experimental results show the feasibility of creating multiple fractures through TPDF, and more importantly give the following findings: (1) a complex diverted fracture network tends to be created at a small differential stress (2.5 MPa in this case), while diverted fractures tend to grow parallel to the initial fractures at a high differential stress (7.5 MPa in this case); (2) with the same concentration in the fracturing fluid, 40-mesh powder-shaped diverters can plug the created fractures and increase the net pressure more rapidly than 6-mm fiber-shaped diverters; (3) an excess of diverters can lead to a strong injection pressure response, and, thus, enhance the difficulty of creating multiple fractures; (4) when diverters are injected with the fracturing fluid, no obvious breakdown pressure or propagation pressure is shown during the fracture propagation.
Improving Safety and Health In the Exploration and Production Process --- A Long-Term Perspective
Authors: Clark Patricia
Published: February 2020

Good morning. It is an honor and a privilege to be one of the keynote speakers at this very important conference on health, safety and the environment in oil and gas exploration and production. This is a vital industry throughout the world, and protecting the safety and health of those who work in it, as well as the environment surrounding oil and gas well operations must be a major concern of everyone.

Today I will attempt to explain to you what the United States Government is doing to help further the goals of this conference, particularly in occupational safety and health because that is my field of expertise.

I am the Director of Compliance Programs for the U.S. Department of Labor's Occupational Safety and Health Administration. My Agency, OSHA, has the responsibility for regulating safety and health in the workplaces and worksites of the United States.
Poor mental health of livestock farmers in Africa: a mixed methods case study from Ghana
Authors: Nuvey Francis Sena , Kreppel Katharina , Nortey Priscilla Awo , Addo-Lartey Adolphina , Sarfo Bismark , Fokou Gilbert , Ameme Donne Kofi , Kenu Ernest , Sackey Samuel , Addo Kennedy Kwasi , Afari Edwin , Chibanda Dixon , Bonfoh Bassirou
Published: February 2020

Background
Agriculture represents the mainstay of African economies and livestock products are essential to the human population’s nutritional needs. However, in many developing countries, including Ghana, livestock production fails to meet demand due to population growth and negative effects of climate change. One of the challenges to production is livestock loss affecting farmers. However, despite stressful events experienced, livestock farmers’ mental health is poorly documented. This study aims to identify the root causes of livestock losses and their influence on pastoralists’ mental health.
Methods
We conducted a mixed methods study in two districts in the Northern and Southern Belts of Ghana. Using the Depression Anxiety and Stress Scale–21 and guided interviews, we collected quantitative and qualitative data from 287 livestock farmers and 24 key-informants respectively. Mental health scores were categorized using standard guidelines. We evaluated the factors that explained variations in mental wellbeing using general linear models (α=0.05).
Results
About 85% (240/287) of the livestock farmers lost cattle within one year. Of these, 91% lost cattle to animal diseases, 50% to theft and 27% to pasture shortages. Qualitative findings reveal that due to poor access to veterinary services, farmers treat livestock diseases themselves with drugs from unregulated sources and often sell diseased cows for meat to recover losses. Findings showed that 60% of livestock farmers had poor mental health. Of those, 72% were depressed, 66% anxious and 59% stressed. Mental wellbeing was negatively associated with the number of adverse events experienced, proportion of livestock lost to most of the major loss factors, emotional attachment to livestock and self-reported physical illnesses in farmers, but positively associated with increasing herd size [F(8,278)=14.18,p<0.001,R2=0.29].
Conclusions
Livestock diseases are the leading cause of losses to livestock farmers, whose mental wellbeing is negatively affected by these losses. Although an adaptive strategy by farmers to compensate for poor veterinary services, the arbitrary use of veterinary drugs and sale of diseased cattle pose health risks to the public. Further research to evaluate the performance of veterinary services in Ghana, mental health problems and risk to human health due to potential high-risk meat entering the food chain, is needed.
Unmet health care needs of elderly residing on urban areas of Sunsari District, Nepal. A Cross Sectional Study
Authors: Poudel Mukesh , Ojha Asmita , Yadav Deepak Kumar , Sah Ram Bilakshan , Chakravartty Avaniendra , Ghimire Anup
Published: February 2020

Background: The global aging population is in increasing trend. Morbidity increases with age and enhances the burden of health problems that result in new challenges to meet additional demands. There can be various types of issues such as health problems, health care utilization, physical and social care which should be carefully assessed and addressed. This study aimed to assess the unmet health care needs among elderly. Methods: A Community based, House to House, Cross-sectional study was conducted in urban areas of the sunsari district using face to face interviews. The sample size of 530 elderly was selected by a systematic proportionate random sampling technique. Results: This study unfurled the prevalence of unmet need for consultation for Nearsightedness 52.3%, Farsightedness 53.7%%, Hearing 79.7%, Dental 79.4%, Hypertension 6.7%, Diabetes 3.9%, CVD 5.3 % among those with these specific health needs and of at least one Unmet Health care need to be 64.9% among the studied participants. At least one unmet health need was significantly associated with higher odds among elderly age more than 70, of dalit and janajati ethnicity, illiterate, poor, those with difficulty leaving home, the distance of health facility > 30 mins, and those with depressive symptoms. Conclusion: The study highlighted the higher prevalence and associated factors related to unmet health care needs among the elderly which should be addressed to promote healthy ageing. There is an urgent need to promote geriatric health services and make it available at the primary health care level the first level of contact with a national health system.