bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bypassing Skepticism to Add Reserve: Cases of Successful Hydraulic Fracturing in Karim Formation
Authors: Al Kalbani M.. , Al Saadi H.. , Mirza M.. , Kurniadi S. D. , Hilal Ahmed , Al Kalbani M. S. , Kelkar S.. 
Published: October 2018

Abstract
When oil prices are low, the oil industry tends to reduce its capital expenditure to fund new projects, such as exploration and development projects. The reduction in exploration activity ultimately affects the operators’ reserve balance. These conditions push each operator to use innovative solutions to increase reserves. Hydraulic fracturing is considered one of these solutions because it enables revisiting the possibility of producing an uneconomic reservoir with the existing wells. One reservoir that is being reevaluated is the Karim formation located in the Karim Small Fields (KSF), the Sultanate of Oman.
The Karim formation is divided into three segments, with the most promising being the Lower Khaleel, which was initially considered uneconomic to develop. The Khaleel is a sandstone formation at approximately 2000 m depth, with fair porosity and permeability and containing moderate-viscosity oil. The current recovery factor in the Khaleel is still less than 5%, and it is not considered for a full-field development plan due to low production results.
Because the wells drilled in the Khaleel formation were not prepared for a fracturing operation, several challenges appeared during early review, including the well trajectory and azimuth, completion condition, intervention strategy, data availability, and reservoir understanding on the formation water source and its connection to the Khaleel. The project was separated into three phases: feasibility and technical study phase, fracturing trials and evaluation phase, and fracturing understanding and optimization phase. Results are available for the first two phases, and a plan has been formulated for the third phase.
The feasibility and technical study involves understanding the geology, geomechanics, and petrophysics of the wells in which a fracturing operation was performed previously in a different formation. This study was followed by a candidate selection step involving more than 10 existing wells. The candidate selection process used a novel workflow to incorporate all the challenges into the selection criteria. Results of the candidate selection phase led to selection of the top three wells for fracturing operations in the Khaleel formation. Two out of three wells were selected for hydraulic fracturing treatment in the initial trial phase. Observations and results have been obtained from the execution of the trial hydraulic fracture jobs in these wells.
A Model for Acid Fracture Conductivity Based on Asperity Deformation with Coupled Normal-Shear Behavior of Rough Surfaces
Authors: Zhang Wenyu , Jin Xiao , Zhu Ding 
Published: October 2018

AbstractNatural fractures are oftentimes not orientated in the direction of in-situ principal stresses. When developing naturally fractured reservoirs, the complex fracture network is affected by the shear stresses acting on the fracture surfaces. In some rare cases, the main fracture may not align with the principal stresses. Under such circumstances, shear stresses and displacements during fracture closure will impact the overall conductivity, especially for acid fracturing treatment, where flow paths are supported by the roughness of unevenly acid-etched fracture walls.In this paper, we present a new approach to model acid fracture conductivity by allowing combined normal and shear loading on fracture walls. The closure of rough surfaces is modeled as elastic deformation of asperities. The model considers the mechanics of asperity contacts and statistical descriptions of interface roughness and asperity contact orientation for shear slippage between asperities. A numerical simulation algorithm is implemented to evaluate the fracture displacement under complex loading conditions. The overall conductivity is then obtained from numerical simulation based on deformed fracture apertures. The model was validated with the experimental observation under normal closure condition. A parametric study was carried out to evaluate the rock mechanical properties and fracture geometries on the conductivity behavior of acid fracturing.Modeling results show that the interface closure behavior can be significantly affected by the asperity contact orientations. If slipping among asperities is considered, larger deformations during fracture closure are observed from simulation comparing to results from conventional fracture closure models based on summit-to-summit asperity contact. Sensitivity analysis indicates that the overall conductivity of a fracture depends on mechanical properties of the rock, distribution of asperity contact orientation, and shear loading conditions.The new approach proposed in this paper provides access to acid fracture conductivity estimation under various in-situ stress conditions and fracture orientations. This model can be helpful in evaluating fracture treatment in reservoirs with natural fractures or complex subsurface structures.
Good Tests Cost Money, Bad Tests Cost More - A Critical Review of DFIT and Analysis Gone Wrong
Authors: Hawkes R. V. , Bachman R.. , Nicholson K.. , Cramer D. D. , Chipperfield S. T. 
Published: October 2018

Abstract
Analysis of mini-frac or, as commonly referred to in North America, Diagnostic Fracture Injection Tests (DFITs), have traditionally been the sub-discipline of completion & hydraulic fracture stimulation engineers. Conducting such tests has direct and indirect costs resulting from the test itself and the extended time required for the pressure falloff, that delays the completion of the well. The benefits must therefore outweigh the costs if the test is to be justified. The value is evident as these tests are performed regularly around the world as it is one of only a few processes that can help quantify within the same test both geomechanical properties and reservoir performance drivers.
The authors will present examples and lessons learned from regions around the world. In addition, the availability of a large quantity of public, high-quality data from oil & gas operators in Western Canada operating in shale and ultra-tight formations enable an assessment of the successes and failures of wellbore completions, reservoir types, and operator procedures. This treasure-trove of data will help completion engineers regardless of their basin of operations to overcome one of industries challenging questions "did the test achieve its objectives."
A Theoretical Model for GHG Emissions Due to Biochar Application in Tropical Agricultural Soils
Authors: Novais Sarah Vieira , Oliveira Zenero Mariana Delgado , Frade Elizio , Lima Renato , Pelegrino Cerri Carlos Eduardo 
Published: October 2018

Core Ideas
Biochar mitigates greenhouse gas (GHG) emissions when applied to soils.
The reduction in biochar pH leads to higher GHG mitigation.
Enhancing biochar pyrolysis temperature also leads to higher GHG mitigation.
CO2 emission is explained negatively by the variables soil texture and biochar pH.
CO2 emission is explained positively by pyrolysis temperature and biochar dose.
Biochar, a pyrolysis product, has the potential to reduce greenhouse gas (GHG) emissions while increasing the soil water holding capacity. The purpose of this paper is to model biochars GHG emission based on its applied dose, its pH value, pyrolysis temperature and soil texture. Poultry manure and sugarcane straw biochar produced at two temperatures (350 and 650°C), were applied in three doses (12.5, 25, and 50 Mg ha−1), to sandy and clayey soils at two soil pH values (original 7.5 and adjusted to 5.5). The concentrations of CO2, CH4 and N2O were determined using gas chromatography. Increasing the biochar pyrolysis temperature and reducing the soil pH to 5.5 reduced the CO2, CH4, and N2O emissions from the soil. The mitigating effect of biochars was more evident in the sandy soil, since the clayey soil was highly buffed. The CO2 emission, explained negatively by the variables soil texture and biochar pH and positively by the variables pyrolysis temperature and biochar dose, had the final equation: CO2 = 82.28 – 0.05Cclay – 0.08pH + 6.98Tpyrolysis + 0.64Dbiochar (R2 = 0.65).
Cover Crops Reduce Nitrate Leaching in Agroecosystems:A Global Meta‐Analysis
Authors: Thapa Resham , Mirsky Steven B. , Tully Katherine L. 
Published: October 2018

Cover crops are well recognized as a tool to reduce NO3− leaching from agroecosystems. However, their effectiveness varies from site to site and year to year depending on soil, cash and cover crop management, and climate. We conducted a meta‐analysis using 238 observations from 28 studies (i) to assess the overall effect of cover crops on NO3− leaching and subsequent crop yields, and (ii) to examine how soil, cash and cover crop management, and climate impact the effect of non‐leguminous cover crops on NO3− leaching. There is a clear indication that nonleguminous cover crops can substantially reduce NO3− leaching into freshwater systems, on average by 56%. Nonlegume–legume cover crop mixtures reduced NO3− leaching as effectively as nonlegumes, but significantly more than legumes. The lack of variance information in most published literature prevents greater insight into the degree to which cover crops can improve water quality. Among the factors investigated, we identified cover crop planting dates, shoot biomass, and precipitation relative to long‐term mean precipitation as potential drivers for the observed variability in nonleguminous cover crop effectiveness in reducing NO3− leaching. We found evidence indicating greater reduction in NO3− leaching with nonleguminous cover crops on coarse‐textured soils and during years of low precipitation (<90% of the long‐term normal). Earlier fall planting and greater nonleguminous shoot biomass further reduced NO3− leaching. Overall, this meta‐analysis confirms many prior studies showing that nonleguminous cover crops are an effective way to reduce NO3− leaching and should be integrated into cropping systems to improve water quality.Core Ideas
Nonleguminous cover crops reduced NO3− leaching by 56% over no cover crop controls.
Nonlegume–legume mixtures reduced NO3− leaching equivalent to nonlegumes, but significantly more than legumes.
Cover crop planting date, shoot biomass, and precipitation affected nonlegume effects on NO3− leaching.
Nonlegumes reduced NO3− leaching more effectively on coarse‐textured soils and in drier years.
Earlier planting dates and greater shoot biomass enhanced NO3− leaching reductions with nonlegumes.
The Effect of Lithology and Agriculture at the Susquehanna Shale Hills Critical Zone Observatory
Authors: Li Li , DiBiase Roman A. , Del Vecchio Joanmarie , Marcon Virginia , Hoagland Beth , Xiao Dacheng , Wayman Callum , Tang Qicheng , He Yuting , Silverhart Perri , Szink Ismaiel , Forsythe Brandon , Williams Jennifer Z. , Shapich Dan , Mount Gregory J. , Kaye Jason , Guo Li , Lin Henry , Eissenstat David , Dere Ashlee , Brubaker Kristen , Kaye Margot , Davis Kenneth J. , Russo Tess , Brantley Susan L. 
Published: October 2018

Core Ideas
Two new subcatchments are used to test the importance of lithology and land use.
Differences in lithology and land use result in differences in soils and waters.
Despite differences, all catchments have a shallow and a deep water table.
The relative importance of flow paths controls distinct chemistry response to discharge.
Cross‐site comparison will ultimately enable upscaling from the catchment to large scale.
The footprint of the Susquehanna Shale Hills Critical Zone Observatory was expanded in 2013 from the forested Shale Hills subcatchment (0.08 km2) to most of Shavers Creek watershed (163 km2) in an effort to understand the interactions among water, energy, gas, solute, and sediment. The main stem of Shavers Creek is now monitored, and instrumentation has been installed in two new subcatchments: Garner Run and Cole Farm. Garner Run is a pristine forested site underlain by sandstone, whereas Cole Farm is a cultivated site on calcareous shale. We describe preliminary data and insights about how the critical zone has evolved on sites of different lithology, vegetation, and land use. A notable conceptual model that has emerged is the “two water table” concept. Despite differences in critical zone architecture, we found evidence in each catchment of a shallow and a deep water table, with the former defined by shallow interflow and the latter defined by deeper groundwater flow through weathered and fractured bedrock. We show that the shallow and deep waters have distinct chemical signatures. The proportion of contribution from each water type to stream discharge plays a key role in determining how concentrations, including nutrients, vary as a function of stream discharge. This illustrates the benefits of the critical zone observatory approach: having common sites to grapple with cross‐disciplinary research questions, to integrate diverse datasets, and to support model development that ultimately enables the development of powerful conceptual and numerical frameworks for large‐scale hindcasting and forecasting capabilities.
Possibilities of using phospho-soda in patients with complicated colon preparation for endoscopy
Authors: Titaeva A. A. , Belousova E. A. , Tereshchenko S. G. 
Published: October 2018

Endoscopic screening is the main method of colon examination. An important factor for the accurate diagnosis of various pathological changes in the mucous membrane of the lower part of the digestive tract is the degree of its visualization, which directly depends on the quality of preparation for colonoscopy. There are many colon cleansers, but the peristaltic motion of the gut slows down in various diseases and syndromes, which results in the reduced accuracy of endoscopy.The paper presents the analysis of colon preparation quality using Phospho-soda (Casen Recordati, S.L., Spain) for colonoscopy in 198 patients with pathological conditions that impedes passage of all bowel contents: inflammatory bowel disease, acromegaly, and hypotonia of the large intestine. The authors carried out a comparative analysis with a control group, which included 106 patients without factors that slowed down the peristaltic motion of the intestine, who were preparing for endoscopic examination according to a similar scheme.The study showed that using Phospho-soda to prepare for endoscopic examination in patients with decreased colonic tone resulted in the efficacy of the drug comparable with its efficacy in a group of patients without dysmotility.
Planejamento Setorial e Regional: um modelo de integração entre ferramentas de previsão aplicado ao transporte rodoviário de cargas
Authors: Blois Henrique Dias , Finamore Eduardo Belisario Monteiro de Castro 
Published: October 2018

Esta pesquisa visa analisar o setor de transporte por meio de um modelo que integra Cenários Prospectivos a Dinâmicas de Sistemas visando prever alternativas futuras para o transporte rodoviário de cargas na Região do COREDE Produção do Rio Grande do Sul/Brasil. Na primeira ferramenta de pesquisa foi adotado o método descrito por Grumbach (2012), no qual peritos contribuem para a construção dos cenários. Após a geração dos cenários, foi realizada a integração com a modelagem hard da Dinâmica de Sistemas que busca disponibilizar alternativas que possibilitem análise, descrição e simulação de tendências para os próximos cinco anos. Os resultados mostram um conjunto de cenários e ações ao apontar oportunidades e ameaças do ambiente externo, pontos fortes e fracos do ambiente interno, fundamentando decisões estratégicas e operacionais no presente. Também realiza previsões para o setor através de simulação, bem como discute a possibilidade da implementação de uma agência de desenvolvimento regional, como um agente facilitador do modelo proposto. O modelo de integração proposto nesse estudo mostrou-se útil porque reduziu o número de incertezas futuras, construídas pela redução de eventos com maior probabilidade de ocorrência. Essa característica é importante pois focaliza o investidor naqueles eventos que podem de fato interferir na evolução do sistema analisado.
Tecnificação de Produtores e Estruturas de Governança no Sistema Agroindustrial de Leite
Authors: Acosta Daniela Caldas , Souza José Paulo de , Bankuti Sandra Mara Schiavi 
Published: October 2018

As evoluções observadas na trajetória do Sistema Agroindustrial (SAG) do leite no Brasil refletiram no modo de operação e nas relações dos segmentos produtor e processador. Embora esse SAG apresente crescimento, a diversidade no nível tecnológico do segmento de produção rural tem efeito sobre o desempenho da cadeia de forma geral, e se estende para a estrutura das relações, impactando na distribuição de valor nas transações. Assim, toma-se como base a proposta de entender a estratégias de organização dos segmentos que integram a cadeia produtiva por intermédio da Economia dos Custos de Transação e Teoria dos Custos de Mensuração, de forma pontual no estado do Paraná. Para isso, o seguinte objetivo foi definido: compreender como se dão as relações entre o segmento produtor e processador no SAG de leite, ao se considerar o nível de especialização tecnológica dos produtores nas diferentes regiões do estado do Paraná. Para isso, utilizou-se procedimentos metodológicos sustentados em pressupostos qualitativos, e pesquisa descritiva. Os dados primários foram obtidos a partir de entrevistas semiestruturadas com produtores e processadores localizados nas diferentes regiões do Estado. Como resultado identificou-se que as estruturas de governança predominantes são de forma híbrida, envolvendo contratos formais e, em sua maioria, informais, requerendo confiança e reputação. A contratação formal se associa a níveis elevados de tecnificação no segmento de produção rural, sendo encontrada apenas na região Centro-Oriental do Estado, indicando que a elevação na capacidade produtiva tem influência na definição dos arranjos, e consequente obtenção de eficiência e melhor distribuição de valor.
Agenda Governamental: influências na sua construção nos municípios integrantes da 31ª Secretaria de Desenvolvimento Regional de Itapiranga – SC
Authors: Söthe Ari , Junior Oklinger Mantovaneli , Kegel Patricia Luiza 
Published: October 2018

A construção das agendas governamentais com a participação dos diversos atores precede o planejamento das políticas públicas. Diante disso, o presente artigo busca descrever a influência dos diversos eventos, atores e questões na construção das agendas dos municípios integrantes de abrangência da 31 Secretaria de Desenvolvimento Regional (SDR) de Itapiranga - SC. Inicialmente por meio da fundamentação teórica foram abordados os principais conceitos sobre políticas públicas e agenda governamental e seus diversos atores. Posteriormente foi realizada uma pesquisa descritiva e exploratória, de abordagem qualitativa, de levantamento por meio de entrevistas junto aos municipios pesquisados. A descrição dos dados evidencia que os entrevistados visualizam as agendas governamentais, como mecanismo fundamental na definição das ideias que devem prevalecer e integrar os planos governamentais. Denota-se que, a mídia tem influência sobre os diversos atores que participam do planejamento e implementação das agendas. Infere-se que a agenda pública é influenciada pelas demandas imediatas e setoriais. Por outro lado, a agenda de políticas públicas governamentais é influenciada por diversos eventos como, frustrações de receitas, judicialização de políticas, agenda eleitoral, entre outros. O fluxo das questões na construção da agenda governamental tem uma pequena competição, seu sucesso ocorre em função da força dos atores e disponibilidade de recursos. As questões são influenciadas pela sua compreensão como problema e suas possíveis soluções, assim como, em alguns casos pelas barganhas políticas. Conclui-se que, diversos atores como a mídia, políticos, lideranças, judiciário, conselhos e os próprios agentes do governo são influentes no processo de construção das agendas.
Development of an Information System of Structures and Force Field Parameters of Chemical Compounds from Sri Lankan Flora
Authors: Rathnayake Samith , Weerasinghe Samantha 
Published: October 2018

Background:
Sri Lanka offers a huge diversity of flora with a large proportion of those
being endemic to the island. Both the endemic and native plants species serve as a rich bank of
phytochemicals.

Method:
In this study, “Sri Lankan Flora” an online web-based information system of phytochemical
compounds isolated from the flora of Sri Lanka was proposed.

Results:
The database contained 3D structures of those compounds, calculated quantitativestructure-
activity relationship (QSAR) data and the GROMOS 54a7 force field parameters for each
and every compound. The manually curated chemical structures, activities and force field parameters
provide a possible direct avenue for computer-aided drug discovery. The present study is a
continuing project with a wider goal of building up a database, not only for assisting the computeraided
drug designing process, but also for other chemical applications, as the database includes
structural, physical, chemical and dynamic properties of chemical compounds of the flora of Sri
Lanka. The database is freely accessible at http://science.cmb.ac.lk/tools/slflora.
Aripiprazole: An FDA Approved Bioactive Compound to Treat Schizophrenia- A Mini Review
Authors: Kumar Arvind , Singh Harpreet , Mishra Amrita , Mishra Arun K. 
Published: October 2018

Objective:
Aripiprazole, a synthetic compound, obtained by chemical modification of the
structure of quinolinone is considered as an atypical antipsychotic drug. The present review is an attempt
to summarize the updated information related to reported chemistry and pharmacology of Aripiprazole.

Development:
Aripiprazole, under development by Otsuka Pharmaceutical, was approved by the U.S.
Food and Drug Administration (USFDA) by the end of 2002 with an aim to treat patients with schizophrenia.
This drug got approved by European Commission in February 2013 to treat the patients having
severe manic episodes in bipolar I disorder Additionally, it got approval in Japan in January 2006 and in
Canada in 2014.

Pharmacology:
Aripiprazole shows high specificity for dopamine receptor especially D2 and D3, serotonin
5-HT1A and serotonin 5-HT2A receptors, reasonable specificity for dopamine D4, serotonin 5-
HT2C and 5-HT7, alpha1-adrenergic and histamine H1 receptors. It also shows moderate specificity for
the serotonin reuptake. The major side effects include headache, agitation, akithesia, anxiety, tachycardia,
insomnia, postural hypotension, constipation, vomiting, dizziness, nervousness and somnolence.

Conclusion:
The present article embarks the available information on Aripiprazole with emphasis on its
clinical pharmacology, mechanism of action, pharmacokinetics, pharmacodynamics, metabolism and
clinical trials.