bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technology Focus: Bit Technology and Bottomhole Assemblies (December 2017)
Authors: Mensa-Wilmot Graham 
Published: November 2017

Technology Focus
Drilling-efficiency improvements, needed to ensure continuous reductions in project cycle time, require holistic drilling-system evaluations. Bottomhole assemblies (BHAs), as part of the drilling system, have dominating effects on the functionality and effectiveness of other system components. BHA design, usage, and monitoring must promote drilling-system compatibility, efficiency, and reliability.
BHA design must provide or contribute to the creation of operational conditions that ensure efficient failure and removal of rocks. Additionally, it must enable the use of appropriate drilling parameters as needed by specific applications without compromising efficiencies of other drilling-system components. Research continues to investigate rock-failure mechanisms and the implications the processes have on drilling performance. Through this effort, it has been identified that different drilling parameters are needed for dissimilar rock types, even when rock hardness, hole sizes, well profiles, and hydraulic considerations are the same. In most cases, these findings dictate the need for different BHAs to accommodate appropriate parameter ranges and sweet spots.
BHA usage must not create conditions that initiate or promote dynamic dysfunctions. Such a condition, while compromising the functional efficiencies of other drilling-system components, also promotes premature downhole-tool failures. The contributions of micro-doglegs to dynamic dysfunctions, excessive torque and drag, poor weight-on-bit transfer, and other issues have been known for a long time. Research into this area is providing a deeper understanding, together with findings that are bound to improve drilling-parameter management and overall drilling efficiency.
Appropriate parameter ranges, and improved BHA compliance with regard to vibrations, improve drilling efficiency. These conditions, though beneficial, are not sufficient to ensure BHA reliability. Considering the effect that BHA failures (e.g., twistoff) have on project cycle time and operational costs, investigators have taken a deeper dive into this issue. With the “whys” and “hows” of BHA failures identified, work flows have been developed to address these reliability issues.
Ensuring BHA efficiency and reliability is critical for drilling performance. These requirements must thread through BHA design, usage, and monitoring. Yes, the industry has the tools and know-how, and it can be done.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 183870 A Modified Three-Point-Contact Approach for Dogleg-Severity Modeling by Hossam Gharib, Halliburton, et al.
SPE 183037 Testing and Characterization of Shock and Vibration Loads To Enhance Drilling-Tool Reliability and Efficiency by Dennis Heinisch, Baker Hughes, a GE company, et al.
OTC 27575 Applying Real-Time Data Analytics To Detect Underreamer Failure Early During Hole Enlargement While Drilling in Deepwater Gulf of Mexico by Xianping Wu, Shell, et al.
How To Design a Bottomhole-Assembly Rotary-Speed Sweet Spot
Authors: Wilson Adam 
Published: November 2017

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper IPTC 18836, “How To Design a BHA Rotary-Speed Sweet Spot,” by Jeffrey R. Bailey, SPE, and Andrius Minkevicius, SPE, ExxonMobil; Alexander Bolzan and Victoria R. Wilkins, Hibernia Management and Development; and Joshua S. Pokluda, Esso Exploration and Production Nigeria, prepared for the 2016 International Petroleum Technology Conference, Bangkok, Thailand, 14–16 November. The paper has not been peer reviewed. Copyright 2016 International Petroleum Technology Conference. Reproduced by permission.
Correct placement of the rotary-speed sweet spot of a bottomhole assembly (BHA) provides multiple benefits toward achieving the ultimate goal of drilling to section total depth in a single trip. The process of BHA redesign and tuning for the desired operating parameters provides greater control over the drilling process. Vibration minimization through proper design and operation of the BHA facilitates drilling objectives that include reaching section depth in fewer trips and providing acceptable borehole quality to run casing to depth.
Introduction
A musician understands the basic principle of a stringed instrument: The frequency of the note made by the instrument varies with the length of the string span. Other parameters play a role, including the string properties and tension. However, once the instrument is tuned and the concert has begun, the musical notes are played principally by changing the length of the vibrating string.
As the finger position is changed on the fingerboard, the pitch of the note changes. Although this is a basic concept to a musician, it is not common today in the oil and gas industry for engineers to apply this concept to BHA design selection.
A BHA is a beam that may be rep-resented by a fourth-order differential equation. Model calculations proceed by subdividing the BHA into elements comprising short sections of pipe in a lumped-parameter model. A 2D model uses a state vector at each mass node comprising the lateral displacement in a plane, tilt angle relative to the center-line, bending moment, and beam shear load. In the lateral bending flex mode, a dynamic side force is applied at the bit at integral multiples of the rotary speed. In the rotary twirl mode, offset mass elements are used to investigate the stability of the BHA to eccentric mass and centrifugal forces.
The dynamic response is considered to be a perturbation from the static solution. The bending strain energy is related to the square of the bending moment in the beam, and calculating the length-averaged BHA bending energy provides a BHA bending-strain-energy vibration index.
Lower values of vibration indices are sought because the dynamic response to a reference input is then minimized (i.e., lower vibrations are then predicted by the model). All such modeled designs are perturbed by identical inputs, and the model results may then be compared on an apples-to-apples basis.
Development of Work Flow To Manage Fatigue of Bottomhole Assemblies
Authors: Wilson Adam 
Published: November 2017

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper IPTC 18682, “Development and Utilization of BHA-Fatigue-Management Work Flow,” by Hendrik Suryadi, SPE, and Phan Van Chinh, SPE, Schlumberger, prepared for the 2016 International Petroleum Technology Conference, Bangkok, Thailand, 14–16 November. The paper has not been peer reviewed. Copyright 2016 International Petroleum Technology Conference. Reproduced by permission.
A new fatigue-management work flow provides drillers with a tool to simulate and predict the life expectancy of bottomhole assemblies (BHAs) before fatigue causes problems. This new feature allows engineers to calculate and monitor the fatigue life. It also helps engineers to take appropriate action before a failure occurs downhole or to provide information to the maintenance team for preventive maintenance. Overall, this new approach allows engineers to manage drilling risks related to fatigue before any negative consequences.
Introduction
The oil and gas industry continues to drill wells that are deeper, more complex, and have greater extended reach and dogleg severity. These wells expose drillstring elements to higher loads and several kinds of cyclic stresses. The success of drilling operations relies on maintaining the integrity of the BHA and the drillstring. One of the more common catastrophic events related with BHA integrity is twistoff, where the BHA component parts from the drillstring downhole. Twistoff can be caused by the load exceeding the collar strength or by high shock, vibration, or corrosion, but the primary cause of twistoff is fatigue failure. With fatigue failure, the drillstring fails downhole despite the stress being below the material-strength specification. This is caused by fatigue accumulated over time. According to some reports, fatigue failure contributes to more than 60% of total drillstring failures.
Fatigue failure can occur under a wide range of conditions and environments; however, a higher risk of fatigue failure always exists when rotating drill collars and tools through high-dogleg intervals during the drilling.
With high rig operating costs and increasing BHA and wellbore complexity, increased focus has been placed on avoiding twistoff-related expenses such as
Cost associated with time required to trip out of the hole
Cost of fishing operations and to repair or replace failed equipment
Cost to perform sidetracking Engineers attempt to prevent drillstring failures by optimizing the drill-string and trajectory designs.
Performance of Cowpea Genotypes in the Brazilian Midwest Using the Bayesian Additive Main Effects and Multiplicative Interaction Model
Authors: de Oliveira Luciano Antonio , da Silva Carlos Pereira , Teodoro Paulo Eduardo , Torres Francisco Eduardo , Corrêa Agenor Martinho , Bhering Leonardo Lopes 
Published: November 2017

Core Ideas
We used the AMMI Bayesian model for selection of cowpea genotypes.We identified two genotypes with more expressive genotypic values.It is not possible to carry out the general recommendation of cowpea genotypes for the Brazilian Midwest.
Cowpea is one of the world's most important tropical and subtropical food sources. In Brazil, it is grown principally in three regions: the Midwest, the Northeast, and the North. This makes the genotype × environment (G×E) interaction a challenge on the recommendation of the best genotypes for these regions. The aim of this study was to use the additive main effects and multiplicative interaction model under the Bayesian approach to recommend the best genotypes for the Brazilian Midwest. Six trials using cowpea genotypes were conducted in the municipalities of Aquidauana, Chapadão do Sul, Dourados, and Primavera. The experimental design included a randomized block design with 20 treatments (17 lines and three cowpea cultivars) and four replications. We identified only two genotypes (G15 and G2) with more expressive genotypic values and whose credibility regions do not include zero. From the credibility regions built for the genotypic and environmental scores, we verify that these genotypes contributed to the G×E interaction, presenting specific adaptability to the subgroup of environments (E5, E6). These results indicate that it is not possible to carry out the general recommendation of high‐yielding cowpea genotypes for the Brazilian Midwest region.
Producing High‐Residue, No‐Till Fallow in the Low‐Rainfall Zone of the Pacific Northwest
Authors: Port Lauren E. , Young Frank L. , Pan William L. 
Published: November 2017

Core Ideas
Use of a stripper header to leave tall stubble for high‐residue no‐till.
Winter triticale outperforms winter wheat in low rainfall dryland production.
Tall crop residue reduces wind speeds at the soil surface.
The low‐rainfall wheat production zone of eastern Washington is subject to wind erosion because of fine‐textured soils, low soil organic matter content, and tillage‐based winter wheat–summer fallow practices. Annual no‐till spring cropping systems to replace the low‐residue, erosive summer‐fallow period have not been economical. We conducted a 4‐year study at Ralston, WA to evaluate winter triticale (× Triticosecale) and non‐semi‐dwarf winter wheat (Triticum aestivum) biomass production, yield, nutrient use efficiency, and seed‐zone soil moisture during no‐till fallow and establishment of fall‐seeded canola. Treatments included winter triticale and winter wheat, both harvested with either a stripper header or conventional cutter‐bar header. Winter triticale produced more grain per pound of N fertilizer and per inch of soil water available than winter wheat, and overall yield was 30–80% greater than that of winter wheat. Full‐height cereals produced 20–90% more biomass than semi‐dwarf winter wheat. Stripper‐header triticale stubble maintained with no‐till chemical fallow (NTCF) reduced average wind speed at the soil surface to less than one‐half of the average wind speed recorded over reduced‐tillage winter wheat fallow. Soil moisture in the 0‐ to 3‐inch seed zone was greater and more uniform in stripper‐header no‐till fallow than in reduced‐tillage fallow. Maintenance of soil moisture by stripper‐header standing stubble was conducive to timely planting and establishment of fall‐seeded canola and led to greater crop establishment in no‐till fallow. Growing a high‐biomass cereal crop such as winter triticale or standard‐height winter wheat and harvesting with a stripper header produces a high‐residue, no‐till fallow that is a viable alternative to the traditional winter wheat–fallow cropping system.
Simple, Simultaneous Gravimetric Determination of Calcite and Dolomite in Calcareous Soils
Authors: Rodriguez Juan B. 
Published: November 2017

Core Ideas
The carbonate meter (CM) method was modified to measure calcite and dolomite.
The modified carbonate meter (MCM) method efficiently separated calcite and dolomite.
The MCM method can be done in any soil testing lab.
The MCM technique not only measures calcite and dolomite but also total inorganic C
The MCM categorized calcareous soils as calcitic, dolomitic, and calcitic‐dolomitic.
Literature pertaining to the determination of calcite and dolomite is not modern and generally describes slow methods that require expensive specialized apparatus. The objective of this paper is to describe a new method that requires no specialized equipment. The separation of calcite and dolomite was done by placing 0.2000 ± 0.0200 g of calcareous soil, 6‐mL glass vial with 4.0 mL of fresh 4 mol L–1 HCl–3% FeCl2 4H2O in a 50‐mL Erlenmeyer flask. The Erlenmeyer flask was capped with the tubed rubber stopper and the carbonate meter's (CM) initial weight was recorded to the accuracy of four decimal places. A second weight was recorded after 30 s of reaction, a third weight was recorded after 30 min of reaction, and the last weight was taken after 22 to 24 h. The linear regressions and correlation coefficient results for calcite and dolomite in calcite–dolomite–soil mixtures with the modified carbonate meter (MCM) were excellent. The precision for calcite was <5% in 92.6% of samples and that for dolomite was <10% in 98.8% of samples. Recovery for calcite was 100 ± 10% in 86.4% of samples and recovery for dolomite was 100 ± 10% in 97.5% of samples. The MCM technique efficiently separated calcite and dolomite in calcareous soils. This procedure is recommended for routine analysis of calcite and dolomite concentrations up to 450 g kg–1. The MCM is easy to follow with good precision and recovery.
Constraints on foreign aid effectiveness in the water, sanitation, and hygiene (WaSH) sector
Authors: Wayland Joshua 
Published: November 2017

AbstractNumerous studies have sought to empirically test the effectiveness of foreign aid as a tool for international development, with often inconsistent or contradictory results. New sources of disaggregated aid data now allow researchers to test the impact of individual sectors of aid on sector-specific outcomes. The paper investigates the effectiveness of foreign aid in the water, sanitation, and hygiene (WaSH) sector and seeks to identify constraints on WaSH aid effectiveness in recipient countries. Multilevel latent growth, dynamic panel, and instrumental variable regression models were estimated on a panel dataset comprising 125 recipient countries over 20 years. WaSH aid was consistently associated with improved health outcomes in middle-income countries; no effect on those outcomes was observed in low-income countries. Potential constraints on the effectiveness of WaSH aid – including political, economic, institutional, and technical constraints – were examined using subgroup analysis. The effectiveness of WaSH aid was found to have been constrained by government ineffectiveness and regulatory quality in recipient countries. Countries with large rural populations also appear to have benefitted less from WaSH aid than more urbanized recipient countries.
Association Between LTF Polymorphism and Risk of HIV-1 Transmission Among Zambian Seropositive Mothers
Authors: Zupin Luisa , Polesello Vania , Segat Ludovica , Kamada Anselmo Jiro , Kuhn Louise , Crovella Sergio 
Published: November 2017

Background: Lactoferrin is a member of the innate immune system acting in the first line of defence against pathogens, and it is known for its antibacterial, antifungal and antiviral activity, including HIV-1. Two polymorphisms, T29A and R47K, in the exon 1 region of the LTF gene (encoding for the lactoferrin protein) were previously described as able to influence the lactoferrin antimicrobial function.Objectives: LTF T29A and R47K genetic variants were analysed in a Zambian population to unravel if these polymorphisms could play a role in HIV-1 mother-to-child HIV-1 transmission.Methods: LTF T29A and R47K polymorphisms were genotyped, using allelic specific fluorescent probes and real time PCR, in a population comprising 101 HIV-1 positive mothers and 333 children born to seropositive mothers.Results: Maternal LTF T29A A/A and A/G genotypes were found to be associated with decreased risk of HIV-1 MTCT, being more frequent among non-transmitter mothers respect to transmitter mothers.Conclusion: Our data suggested that maternal LTF genetic background contributes to the susceptibility to HIV-1 transmission from mother to new-borns.
Assessment of Posterior Segment Using Spectral Domain OCT in Highly Myopic Eyes
Authors: AttaAllah Heba Radi , Omar Ismail Ahmed Nagib , Abdelhalim Ahmed Shawkat 
Published: November 2017

Purpose:
Spectral Domain Optical Coherence Tomography (SD-OCT) was used to evaluate retinal and vitreo-retinal changes that occur in highly myopic patients.

Methods:
This prospective study included 472 eyes of 472 patients suffering from high myopia (> -6.00 D), between May 2012 and December 2015. All patients were examined, using Cirrus HD OCT (Zeiss Cirrus TM HD-OCT model 4000), to detect any retinal or vitreo-retinal interface abnormalities.
All obtained data was analyzed using Statistical Package for the Social Sciences software version 17 (SPSS Inc, Chicago, IL, USA) and the paired two-sided t-test. Bivariate correlations were performed between different parameters using the Spearman correlation coefficient (r).

Results:
Mean spherical equivalent (MSE) was -13.11± 4.35D. Mean axial length (AL) was 28.5±1.62 mm. Posterior vitreous detachment (PVD) was the most frequent OCT finding; representing 33.4% of the cases, 13.7% of them were associated with macular traction. A statistically significant positive correlation was found between AL and MTM, full thickness macular hole, PVD with traction, and dome shaped macula (r = 0.49 and P = 0.001, r = 0.422 and P = 0.0001, r = 0.25 and P = 0.03, r=0.475, P=0.001 respectively)

Conclusion:
OCT is a valuable tool in detecting retinal and vitreo-retinal interface abnormalities in highly myopic eyes, and it can be used for follow up of those patients to avoid advanced retinal damage.
Developing Communicative English Language Tests for Tourism Vocational High School Students
Authors: Astawa I Nengah , Mantra Ida Bagus Nyoman , Widiastuti Ida Ayu Made Sri 
Published: November 2017

The present study aimed at developing communicative language tests for vocational high school students. A Research and Development design was employed in this study with the primary target was to develop communicative English language tests. The main procedures in the development of the test include: (1) identifying objectives, (2) developing the test specification, (3) developing the communicative tests, (4) analyzing the results of the preliminary tryout of the communicative tests drafts, (5) revising the communicative test drafts, (6) trying out the communicative test drafts, (7) analyzing the results of the tryout of the communicative tests, (8) revising the communicative test drafts. Questionnaires and observation blanks sheet was used to gather comments, opinions, and criticisms on the draft of communicative tests from a number of selected experts. The analysis of the communicative tests tryout was done to ensure the validity, reliability, and practicality of the tests.
Cinema e educação: repertório, temáticas e articulações
Authors: Junqueira Filho Gabriel De Andrade 
Published: November 2017

O artigo tem como origem o curso Cinema e Educação: repertório, temáticas e articulações, oferecido dentro da programação do projeto Vagalume, Laboratório de Estudos em Audiovisual e Educação, do Programa de Alfabetização Audiovisual, na cinemateca Capitólio, em Porto Alegre(RS), entre setembro e outubro de 2015.Parte da premissa de que o cinema pode educar e ser um grande aliado do professor e dos alunos para conhecerem mais sobre os conteúdos curriculares e os projetos que pretendem realizar ao longo do ano, com diferentes propósitos (Xavier; Bergala; Duarte e Alegria; Fresquet; Fantin; Mello; Migliorin; Junqueira Filho e Barbosa). Para isso, é preciso conhecer o que o cinema já produziu sobre diferentes temáticas, dentre elas, as que interessam a professores e alunos a cada momento do ano letivo. Como saber que filmes selecionar para discutir uma temática? Como acessar esses filmes? Como elaborar um roteiro de exploração para cada filme e para cada temática? Essas foram as perguntas que deram origem ao curso e que procuramos responder coletivamente ao longo dos quatro encontros. Outras perguntas surgiram durante o curso, indicando especificidades de demanda dos alunos: Como organizar situações prazerosas nas quais professores e alunos de dois a três anos possam assistir a filmes e conversar sobre eles? Como o cinema pode ajudar os professores a reencantarem alunos do ensino médio, que vivem cotidianamente em meio à violência, para os estudos e para a vida? Essas trocas entre alunos e professores produziram uma ampliação significativa das possibilidades de articulação entre cinema e escola e reforçaram a necessidade de planejamento e de elaboração de projetos de trabalho para o uso de filmes nos diferentes níveis de escolaridade.
Notas sobre uma Residência Pedagógica no Museu de Arte do Rio
Authors: Munhoz Angélica Vier , Costa Cristiano Bedin da , Guedes Betina Silva 
Published: November 2017

O presente artigo parte de uma residência pedagógica realizada no Museu de Arte do Rio (MAR), para desenvolver uma análise das práticas produzidas pelos educadores que lá atuam. Essa análise coloca foco no espaço instaurado a partir das interlocuções realizadas entre público e obra, significando-o como um texto. Para tanto, estabelece com Roland Barthes o esteio teórico que subsidia o mapeamento de percepções e sensações realizado. Metodologicamente, cria formas de apontar ressonâncias entre as práticas de mediação desenvolvidas pelos educadores, um funcionamento curricular aberto à imprevisibilidade dos encontros, e a potência das múltiplas dimensões dos espaços engendrados nessa rede que tem por base a educação. Por fim, faz-se a defesa da mediação enquanto uma prática comprometida com a supressão do distanciamento existente entre os desejos do autor e a experiência do espectador, de maneira que a vivência artística seja, sobretudo, um convite à criação de novos sentidos: para a obra, para a arte, para a vida.