bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Karst Spring Flow Cessation Using Grey System Model
Authors: Guo Yaru , Yeh Tian-Chyi Jim , Hao Yonghong
Published: September 2019

Globally karst aquifers store large amount of precious water and create beautiful karst springs in many places. However, most of the karst springs flow declined, and some of the karst springs dried up with the effects of extensive groundwater development and climate variation. For example, Jinci Springs (China) is known for the beautiful landscape it created and large area of paddy fields it irrigated. Unfortunately, it dried up in May 1994. For better understanding of the hydrological processes of karst springs, this study introduced grey system models to quantify spring flow taking Jinci Springs as an example. Based on the characteristics of Jinci Springs flow, the spring flow was divided into two stages: the first stage (1954-1960), when the spring flow was affected only by climate variation; and the second stage (1961-1994), when the flow was impacted by both climate variation and anthropogenic activities. Results showed that the Jinci Springs flow had strong relations with precipitation occurring one year and three years earlier in the first stage. Subsequently, a grey system GM (1, 3) model with one-year and three-year lags was set up for the first stage. By using the GM (1, 3) model, we simulated the spring flow in the second stage under effects of climate variation only. Subtracting the observed spring flow from the simulated flow, we obtained the contribution of anthropogenic activities to Jinci Springs cessation. The contribution of anthropogenic activities and climate variation to Jinci Springs cessation was 1.46m3/s and 0.62m3/s, respectively. Finally, each human activity causing spring flow decline was estimated.
Face Detection with a portable architecture in Real Time
Authors: De Feo Francesco , De Luca Pasquale
Published: September 2019

Nowadays, security is a top priority. In fact, biometrics uses cutting-edge technologies to identify terrorists and criminals. But the practice of distinguishing humans based on intrinsic physical or behavior traits goes back thousands of years. With the widespread use of computers in the late 20th century, new possibilities for digital biometrics emerged and new technologies were generously used. Among these, we remember high resolution security video cameras and drones. So, the aim of the present project is to study and explain the features of these technologies, especially the ones of the the Phantom 4 Pro+ aircraft and analyze its operating methods in order to identify human faces during live streaming of videos. For this purpose, it will be used Paul Viola and Michael Jones’ face detection algorithm, which includes Haar features and cascade classifiers to identify faces, eyes and ears of an individual.
OCR4all - An Open-Source Tool Providing a (Semi-)Automatic OCR Workflow for Historical Printings
Authors: Reul Christian , Christ Dennis , Hartelt Alexander , Balbach Nico , Wehner Maximilian , Springmann Uwe , Wick Christoph , Grundig Christine , Büttner Andreas , Puppe Frank
Published: September 2019

Optical Character Recognition (OCR) on historical printings is a challenging task mainly due to the complexity of the layout and the highly variant typography. Nevertheless, in the last few years great progress has been made in the area of historical OCR, resulting in several powerful open-source tools for preprocessing, layout recognition and segmentation, character recognition and post-processing. The drawback of these tools often is their limited applicability by non-technical users like humanist scholars and in particular the combined use of several tools in a workflow. In this paper we present an open-source OCR software called OCR4all, which combines state-of-the-art OCR components and continuous model training into a comprehensive workflow. A comfortable GUI allows error corrections not only in the final output, but already in early stages to minimize error propagations. Further on, extensive configuration capabilities are provided to set the degree of automation of the workflow and to make adaptations to the carefully selected default parameters for specific printings, if necessary. Experiments showed that users with minimal or no experience were able to capture the text of even the earliest printed books with manageable effort and great quality, achieving excellent character error rates (CERs) below 0.5%. The fully automated application on 19th century novels showed that OCR4all can considerably outperform the commercial state-of-the-art tool ABBYY Finereader on moderate layouts if suitably pretrained mixed OCR models are available. The architecture of OCR4all allows the easy integration (or substitution) of newly developed tools for its main components by standardized interfaces like PageXML, thus aiming at continual higher automation for historical printings.
POU-SLAM: Scan-to-Model Matching Based on 3D Voxels
Authors: Jiang Jianwen , Wang Jikai , Wang Peng , Chen Zonghai
Published: September 2019

Purpose: Localization and mapping with LiDAR data is a fundamental building block for autonomous vehicles. Though LiDAR point clouds can often encode the scene depth more accurate and steadier compared with visual information, laser-based Simultaneous Localization And Mapping (SLAM) remains challengeable as the data is usually sparse, density variable and less discriminative. The purpose of this paper is to propose an accurate and reliable laser-based SLAM solution. Design/methodology/approach: The method starts with constructing voxel grids based on the 3D input point cloud. These voxels are then classified into three types to indicate different physical objects according to the spatial distribution of the points contained in each voxel. A global environment model with Partition of Unity (POU) implicit surface is maintained along the process and located voxels are merged into it from stage to stage, through scan-to-model matching implemented by Levenberg-Marquardt method. Findings: We find a laser-based SLAM method. The method uses POU implicit surface representation to build the model and is evaluated on the KITTI odometry benchmark without loop closure. Experimental results indicate that the method achieves accuracy comparable to the state-of-the-art methods. Originality/value: We propose a novel, low-drift SLAM method, which falls into a scan-to-model matching paradigm, operates on point clouds obtained from Velodyne HDL64. The method is of value to researchers developing SLAM systems for autonomous vehicles.
Fusarium species and Fusarium mycotoxins in grain of wheat in Poland in 2009 and 2010
Authors: Góral Tomasz , Ochodzki Piotr , Nielsen Linda Kærgaard , Walentyn-Góral Dorota
Published: September 2019

The aim of the study was to determine the presence Fusarium species and mycotoxins in winter wheat grain in Poland. Grain samples from different locations in Poland in 2009 and 2010 were analysed for the content of biomass of Fusarium species and mycotoxins. In 2009 biomass of F. graminearum and F. poae was present in all samples, F. culmorum in 82% of samples, F. avenaceum in 55% of samples. F. sporotrichioides, F. tricinctum and F. equiseti were found only in individual samples. F. langsethiae was not detected. In 2010, five Fusarium species were detected with the exception of F. sporotrichioides. The highest content of biomass was found for F. graminearum followed by F. avenaceum, F. poae and F. langsethiae. The amount of F. culmorum biomass was very low. The most frequently occurring species was F. poae and F. graminearum. In 2009, deoxynivalenol was detected in all samples. In 2010, the average content of deoxynivalenol was lower than in 2009. Nivalenol was detected at very low concentration in both years. Significant correlations between content of F. graminearum biomass and deoxynivalenol concentration in grain and between content of F. poae biomass and nivalenol concentration in grain in 2009 were found. The most important finding of this study was that main Fusarium species infecting wheat kernels in Poland in both years was F. graminearum. The amount of biomass of F. graminearum was the highest in both years. It was present in the most samples. The other frequently detected species was F. poae, which in 2010 appeared in more samples than F. graminearum. However, the amount of F. poae biomass was lower. F. culmorum, species that was previously dominating as wheat pathogen in Poland, was found less frequently than F. graminearum. The amount of biomass of this species was the lowest in 2010.
Molecular Dynamics Study on the Li Diffusion Mechanism and Delithiation Process of Li2MnO3
Authors: Huang Yang , Liu Long , Gao Min
Published: September 2019

Li2MnO3 is critical component in the well-studied Li-excess cathode materials xLi2MnO3•(1- x)LiMO2 for achieving high lithium storage capacity. In this article, the diffusion of Li ions in Li2MnO3 is studied using molecular dynamics (MD) simulation with well-behaved empirical force fields obtained by fitting against the crystal structure from experiment and phonons calculated using Density Function Theory (DFT). We have found two possible tetrahedral hopping channels, 0-TM and 1-TM(Mn4+) channel, which are differentiated by the face sharing octahedral cations. Simulation results show that the 0-TM channel is active for Li hopping, while 1-TM(Mn4+) channel is inactive. During the delithiation process, the Li ions in the TM layered are firstly removed, then those in the Li layer. However, the Li ions will be trapped in the tetrahedral 0-TM channels as long as the four face sharing octahedral sites are cleared. Up to x=1.0 for Li2-xMnO3, almost all the Li ions are located at the tetrahedral sites, forming a regular array along a axis. The de-intercalation of tetrahedral Li ions requires a high voltage (>5.2 V vs. Li/Li+), limiting the practical capacities measured in lab. The diffusion of Mn ions into the Li layers is observed in a deeper delithiated structure (x=1.2 for Li2-xMnO3), indicating an initial phase transformation to a spinel-like structure. However, the Mn ions are mainly trapped in the tetrahedral sites in the Li layer, instead of the octahedral sites fin spinel-like structure. A few of Mn ions diffusing into the octahedral sites in Li layers have no face sharing tetrahedral Li ions, revealing a further Li de-intercalation is imperative for the complete phase transformation. Our model is not stable for x≥1.4 in Li2-xMnO3. Other charge compensation mechanism should be considered in this high delithiation stage, eg. oxygen release.
The Qibla Direction of the Great Mosque Inherited from the Islamic Kingdom in Java: Myth and Astronomy Perspective
Authors: Sabiq Fairuz
Published: September 2019

The determination of the direction of the qibla at the Great Mosque that was inherited from the Islamic Kingdom of Java had executed by waliyullah. Through the folklore and history of the Land of Java or known as a Babad, those stories explained that waliyullah was the person who determining direction of Qibla by raising his right-hand and holding Masjidil Haram in Makkah. On the other hand, he was holding mustoko of the mosque. A line between his right and left-hand as a line of direction of the mosque’s Qibla. This kind of story was widespread in society as a myth. This myth was related to karomah (divine distinction) of waliyullah. Therefore, Qibla of the mosque could not be changeabled, eventhough, the qibla direction of Great Mosque is not unidirectional with direction of Masjidil Haram. People’s opinions said that Qibla direction of the mosque is right according to jihatul Ka’bah. This research is integrated with myth and astronomy. The results of this research are different from formerly perspectives. Firstly, ulama received the result of myth but they were not catching messages of the myth. Ulama were only understood of the explicit meanings of the myth but they were not understand of the implicit meanings of the myth. Secondly, Sunan Kalijaga had determined direction Qibla of the Mosque with his knowledge about falak, he was not doing it by only his karomah (divine distinction). Thirdly, the direction of the Qibla at the Great Mosque that was inherited from the Islamic Kingdom of Java was determined its Qibla direction by using ‘ainul Ka’bah method and not only by using jihatul Ka’bah method. The last, Java society has a feodalistic character.
Outbreaks of Hepatitis A in US Communities, 2017–2018: Firsthand Experiences and Operational Lessons From Public Health Responses
Authors: Snyder Michael R. , McGinty Meghan D. , Shearer Matthew P. , Meyer Diane , Hurtado Christopher , Nuzzo Jennifer B.
Published: September 2019

Objectives. To identify and analyze common challenges from multiple US communities affected by the hepatitis A epidemic beginning in March 2017, and to identify operational lessons to support preparedness for similar future public health emergencies.

Methods. We conducted semistructured interviews with health officials from 9 city or county health departments to collect the firsthand experience of public health responders. We collected data from January to October 2018 via teleconference. Key informants, whom we purposefully sampled, were senior public health officials who were directly involved in outbreak response or in preparing for potential hepatitis A outbreaks in their communities.

Results. Several themes emerged during these discussions, including common challenges and solutions pertaining to sanitation and hygiene infrastructure, hepatitis A vaccination, health workforce availability and surge capacity, communication and stigma, and partnerships and coordination with local law enforcement and other stakeholders.

Conclusions. By generating key, evidence-based operational lessons, this study can inform response activities in localities currently experiencing outbreaks as well as community preparedness for possible future outbreaks due to the presence of similar at-risk populations.
Preassessment of Community-Based Organization Preparedness in Two Sectors, Human Services and Faith Based: New York City, 2016
Authors: Rivera Luis , Pagaoa Melissa , Molinari Noelle-Angelique , Morgenthau Beth Maldin , LeBlanc Tanya Telfair
Published: September 2019

Objectives. To determine the level of preparedness among New York City community-based organizations by using a needs assessment.

Methods. We distributed online surveys to 582 human services and 6017 faith-based organizations in New York City from March 17, 2016 through May 11, 2016. We calculated minimal indicators of preparedness to determine the proportion of organizations with preparedness indicators. We used bivariate analyses to examine associations between agency characteristics and minimal preparedness indicators.

Results. Among the 210 human service sector respondents, 61.9% reported emergency management plans and 51.9% emergency communications systems in place. Among the 223 faith-based respondents, 23.9% reported emergency management plans and 92.4% emergency communications systems in place. Only 10.0% of human services and 18.8% of faith-based organizations reported having funds allocated for emergency response. Only 2.9% of human services sector and 39.5% of faith-based sector respondents reported practicing emergency communication alerts.

Conclusions. New York City human service and faith-based sector organizations are striving to address emergency preparedness concerns, although notable gaps are evident.

Public Health Implications. Our results can inform the development of metrics for community-based organizational readiness.
Preparedness and Community Resilience in Disaster-Prone Areas: Cross-Sectoral Collaborations in South Louisiana, 2018
Authors: Pollock Miranda Joy , Wennerstrom Ashley , True Gala , Everett Ashley , Sugarman Olivia , Haywood Catherine , Johnson Arthur , Meyers Diana , Sato Jennifer , Wells Kenneth B. , Arevian Armen C. , Massimi Michael , Berry Jasmine , Riefberg Leah , Onyewuenyi Nkechi , Springgate Benjamin
Published: September 2019

Objectives. To determine how community-based organizations (CBOs) define priorities for bolstering community resilience, challenges in addressing these priorities, and strategies to address challenges.

Methods. The Community Resilience Learning Collaborative and Research Network (C-LEARN) is a multiphase study examining opportunities to improve community resilience to the threats of disaster and climate change in South Louisiana. Phase I of C-LEARN involved using the National Health Security Strategy and Implementation Plan for directed content analysis of key informant interviews with CBO representatives from 47 agencies within South Louisiana between February and May 2018.

Results. CBO interviewees highlighted the importance of forging relationships and building trust through diverse cross-sector collaborations and partnerships before disasters. Such collaborations and partnerships were shown to tailor disaster response to the needs of particular communities and populations as well as address key challenges such as gaps in information, services, and resources.

Conclusions. Our results encourage a culture of community resilience and community preparedness through partnerships and community-engaged strategies. C-LEARN will utilize the results of our interviews in the design of phase II of our agency-level coalition-building intervention.
The PanVax Tool to Improve Pandemic Influenza Emergency Vaccination Program Readiness and Partnership
Authors: Carias Cristina , Lehnert Jonathan D. , Greening Bradford , Adhikari Bishwa B. , Kahn Emily B. , Meltzer Martin I. , Graitcer Samuel B.
Published: September 2019

Objectives. To show how the Centers for Disease Control and Prevention’s Pandemic Vaccine Campaign Planning Tool (PanVax Tool) can help state and local public health emergency planners demonstrate and quantify how partnerships with community vaccine providers can improve their overall pandemic vaccination program readiness.

Methods. The PanVax Tool helps planners compare different strategies to vaccinate their jurisdiction’s population in a severe pandemic by allowing users to customize the underlying model inputs in real time, including their jurisdiction’s size, community vaccine provider types, and how they allocate vaccine to these providers. In this report, we used a case study with hypothetical data to illustrate how jurisdictions can utilize the PanVax Tool for preparedness planning.

Results. By using the tool, planners are able to understand the impact of engaging with different vaccine providers in a vaccination campaign.

Conclusions. The PanVax Tool is a useful tool to help demonstrate the impact of community vaccine provider partnerships on pandemic vaccination readiness and identify areas for improved partnerships for pandemic response.
Small Area Estimates of Populations With Chronic Conditions for Community Preparedness for Public Health Emergencies
Authors: Holt James B. , Matthews Kevin A. , Lu Hua , Wang Yan , LeClercq Jennifer M. , Greenlund Kurt J. , Thomas Craig W.
Published: September 2019

Objectives. To demonstrate a flexible and practical method to obtain near real-time estimates of the number of at-risk community-dwelling adults with a chronic condition in a defined area potentially affected by a public health emergency.

Methods. We used small area estimation with survey responses from the 2016 Behavioral Risk Factor Surveillance System together with a geographic information system to predict the number of adults with chronic obstructive pulmonary disease who lived in the forecasted path of Hurricane Florence in North and South Carolina in 2018.

Results. We estimated that a range of 32 002 to 676 536 adults with chronic obstructive pulmonary disease resided between 50 and 200 miles of 3 consecutive daily forecasted landfalls. The number of affected counties ranged from 8 to 10 (at 50 miles) to as many as 119 to 127 (at 200 miles).

Conclusions. Community preparedness is critical to anticipating, responding to, and ameliorating these health threats. We demonstrated the feasibility of quickly producing detailed estimates of the number of residents with chronic conditions who may face life-threatening situations because of a natural disaster. These methods are applicable to a range of planning and response scenarios.
Surgical Treatment of Pelvic Discontinuity
Authors: Szczepanski Jason R. , Perriman Diana M. , Smith Paul N.
Published: September 2019

Background:

Pelvic discontinuity is a rare condition that is treated with a range of implant constructs. However, surgical failure rates are high, and outcome data are inconsistent. It is therefore difficult to gain a clear picture of whether recently developed constructs (antiprotrusio cage [APC], cup-cage, custom triflange, and porous metal) provide better outcomes in terms of mechanical failure and complications in the short to long terms. This study investigated the failure and complication rates associated with cage constructs and porous metal technologies.

Methods:

A systematic review and meta-analysis were performed according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines to evaluate the studies showing pelvic discontinuity in revision total hip arthroplasty. Data retrieved included the intervention performed, length of follow-up, mechanical failure, and other complication rates (dislocation, infection, neurological, loosening, migration). Study quality was assessed with the Methodological Index for Non-Randomized Studies (MINORS) instrument. Pooled mechanical failure and complication rates were calculated using MetaXL 5.3.

Results:

None of the included 30 articles (n = 585 hips) were of high quality. The meta-analyses revealed a mechanical failure rate of 14% for all constructs combined. Custom triflange (5%) and cup-cage (7%) had the lowest mechanical failure rates compared with the commonly used APC (25%) and porous metal (12%). The overall other complication rate was 28%, with cup-cage lower at 21% compared with APC (34%) and custom triflange (28%). Long-term evidence investigating both interventions and porous metal technology is limited.

Conclusions:

Mechanical failure rates for cup-cage and custom triflange were lowest. The other complication rate for cup-cage was lower than the pooled average. The study quality was limited, indicating a need for better studies and/or a registry.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Cell-Based and Scaffold-Based Therapies for Joint Preservation in Early-Stage Osteonecrosis of the Femoral Head
Authors: Maruyama Masahiro , Lin Tzuhua , Pan Chi-Chun , Moeinzadeh Seyedsina , Takagi Michiaki , Yang Yunzhi Peter , Goodman Stuart B.
Published: September 2019

» Numerous basic-science and translational studies of cell-based and scaffold-based therapies are currently being performed.

» The advantages and limitations of cell-based therapy for osteonecrosis of the femoral head, including bone marrow-derived mononuclear cells (BM-MNCs), mesenchymal stem cells (MSCs), and MSC-derived exosomes, are being examined preclinically.

» A range of ceramic-based, polymer-based, hydrogel-based, and composite scaffolds have been used for the treatment of osteonecrosis of the femoral head in order to physically or functionally support bone repair and remodeling.

» Modulation of the pro-inflammatory response at an appropriate time point has enhanced bone formation in experimental models. The therapeutic potential of these strategies in translational models of osteonecrosis of the femoral head has not been fully clarified.
Presencia de Hemidactylus frenatus y Hemidactylus mabouia (Squamata: Gekkonidae) en Leticia, Amazonia colombiana
Authors: Caicedo Portilla José Rancés
Published: September 2019

Se documenta la presencia del geco casero común Hemidactylus frenatus en la ciudad de Leticia, Colombia. La especie posiblemente ingresó a esta región por vías aéreas o fluviales. Se registra a Hemidactylus frenatus y H. mabouia coexistiendo en un punto del centro de la ciudad, donde H. frenatus parece estar desplazando a H. mabouia. Posiblemente, la especie se seguirá dispersando a otros centros poblados de la cuenca amazónica y podría, entrar a Brasil. H. frenatus podría llegar a dispersarse a hábitats naturales, como ha sucedido en otras regiones del mundo, lo cual sería desfavorable para las poblaciones de gecos y otros lagartos pequeños nativos de la Amazonia. Se deben realizar monitoreos constantes en Leticia para entender y rastrear los patrones de dispersión de esta especie en la cuenca amazónica.
Factores determinantes de la innovación en el subsector de instituciones de educación superior en Colombia entre 2014 y 2015
Authors: Castro-Torres Ivonne Edith , Méndez-Ortiz Edwin Leonardo
Published: September 2019

Rev.esc.adm.neg

Este artículo de investigación tiene por objetivo estimar los factores determinantes de la innovación en instituciones de educación superior (IES) de Colombia en el período 2014 – 2015, mediante la utilización de un modelo Logit Multinomial Ordenado, en el que se categorizan de manera ordenada los tipos de innovación considerados por el DANE (Departamento Administrativo Nacional de Estadística), donde se asignaron los valores de 0 a las IES que no obtuvieron innovaciones, 1 a las IES que tuvieron la intención de innovar, 2 a las IES potencialmente innovadoras, 3 a las IES que tuvieron innovaciones en sentido amplio y 4 a las IES que obtuvieron innovaciones en sentido estricto.

Para ello, fueron utilizados los datos arrojados por la encuesta de desarrollo e innovación tecnológica, sector servicios y comercio 2014 – 2015, considerando 231 instituciones de educación superior, de tal forma que la estimación realizada fue poblacional y no muestral. 

Así mismo, fueron categorizadas en tres grupos las variables independientes: esfuerzo innovador, apalancamiento externo y obstáculos de la innovación. Se encontró que en su mayoría estas variables son significativas y acordes a la relación establecida en la hipótesis de estudio.

Finalmente se estableció la probabilidad de evento que tiene cada tipo de innovación en una IES representativa para Colombia, y los impactos que tienen los factores determinantes de la innovación en cada categoría de innovación.
Aportes a la construcción del estado de arte del emprendimiento femenino en Colombia
Authors: Forero-Bernal Lida Alexandra , Durán-Duarte Lizeth Katherine
Published: September 2019

Rev.esc.adm.neg

Contribuir en la construcción del estado del arte del emprendimiento femenino en Colombia fue el propósito del proyecto, cuyos resultados se exponen mediante este artículo, el cual presenta una revisión documental que inició con la búsqueda general de términos a través del tesauro emprendimiento femenino y género usando operadores boléanos y truncadores y que se centró en bases de datos como EBSCO, Redalyc, Dialnet y Scielo.

A través de esta revisión se pudo identificar, entre otros elementos, que existen pocos estudios en el tema de género específicamente, lo que deja en evidencia los vacíos existentes en el conocimiento relativo al emprendimiento femenino. Así mismo, se pudo evidenciar que en el trabajo investigativo sobre este campo se emplean similares diseños metodológicos, que en general se basan en investigación bibliográfica, análisis de casos, análisis cuantitativos y cualitativos y con poca frecuencia, en el uso de software estadístico, para correlacionar las variables involucradas.

Finalmente, fue posible establecer que la investigación en el tema viene enriqueciéndose en la medida que aumenta la presencia de mujeres en cargos directivos, pese a esto, aún hay barreras y estereotipos por superar y por ende se hace importante estudiar esta temática en particular.
Intención emprendedora en Colombia: el caso de los estudiantes de Maestría en Administración
Authors: Tarapuez-Chamorro Edwin , Flórez-Laiseca Adriana María , Giraldo-Correa María Patricia
Published: September 2019

Rev.esc.adm.neg

El objetivo de esta investigación fue determinar cómo se asocian los factores que influyen en la intención emprendedora (IE) en Colombia y cuáles de ellos resultan de mayor relevancia.  La investigación realizada fue de tipo descriptivo y tiene alcance correlacional. El trabajo se fundamenta en la Teoría del Comportamiento Planeado y se adicionan variables socioeconómicas y la facilidad para hacer negocios según el Doing Business.

Para ello se aplicó un instrumento de recolección de información a una muestra de 485 estudiantes de 36 programas de Maestría en Administración en Colombia; los datos se procesaron mediante dos métodos estadísticos: Análisis de Correspondencias Múltiples (ACM) y Regresión Logística (RL). 

Este análisis posibilitó establecer nueve factores que determinan la IE de los estudiantes de Maestría en Administración en Colombia, de los cuales tres corresponden a normas sociales, dos son actitudes, dos pertenecen a control del comportamiento y dos atañen a aspectos socioeconómicos.

Así mismo, se encontró que, según el ACM, las personas con mayor IE están relacionadas con ciudades que tienen facilidad alta y media para hacer negocios; esta relación puede tener asidero en el hecho de que las poblaciones en las que es más fácil crear empresas tengan un contexto más apropiado que facilita la actividad emprendedora. 

Se concluye entonces que una mayor intención emprendedora se encuentra determinada por la combinación de este conjunto de variables, que en orden de importancia corresponden a normas sociales, actitudes y control de comportamiento, unidas a algunos aspectos socioeconómicos.
Estratégias de captação de recursos do Observatório Social de Sorriso- Mato Grosso, Brasil
Authors: Matos Costa Elizangela , Caparróz-Carvalho Adriana Santos , Andressa Rosa Michele Jackeline , Neder Renato , Ribeiro da Costa Sandro
Published: September 2019

Rev.esc.adm.neg

Esta pesquisa teve como objetivo identificar estratégias pelo Observatório Social de Sorriso (OSS-MT), Mato

Grosso, Brasil, para atrair recursos financeiros durante o período de 2010 a 2015. Este estudo caracteriza-se por uma abordagem qualitativa, exploratória e de estudo de caso. Para coleta de dados se aplicaram entrevistas semiestruturadas, com um total de seis perguntas abertas e quatro fechadas. Estas entrevistas foram realizadas em três gerentes que estiveram à frente durante o período de 2010 a 2015 e, em

seguida, foi utilizada a análise de conteúdo.

s resultados permitem identificar que a instituição não é suficientemente conhecida pela pouca divulgação, o

que pode constituir um obstáculo à captação de recursos. Os resultados também mostram que, nos três períodos de gestão foram aplicados, em geral, as mesmas estratégias de captação de recursos: visitas a empresas para divulgação do trabalho; transparência financeira para a sociedade; relacionamento com potenciais doadores e participação em eventos e conferências, e apenas um dos gerentes se preocupou em aderir uma nova estratégia para arrecadar fundos a curto prazo, a venda de selos, indicando a necessidade de profissionalização organizacional e o desenvolvimento de estratégias inovadoras para a consecução dos objetivos e viabilidade dos resultados.
Diseño de estrategias para incentivar la participación de los estudiantes del programa Administración de Empresas en los semilleros de investigación de la Universidad de la Amazonía
Authors: Díaz-López Luz Marelby , Ruiz-Claros Clarivel , Cuellar-Cuellar Kerly Yurany
Published: September 2019

Rev.esc.adm.neg

Los semilleros de investigación son escenarios formados por docentes y estudiantes que impulsan el aprendizaje a través de la cultura formativa, dinámica y participativa, donde la creatividad, el trabajo colectivo y el pensamiento crítico son el eje de la investigación formativa, puesto que este tipo de espacios permiten, en la educación superior, forjar una formación integral en los profesionales, de acuerdo a las exigencias del mercado laboral. 

Identificar los factores que inciden en la baja incorporación de los estudiantes del programa Administración de Empresa en los semilleros de investigación de la Universidad de la Amazonia, constituye el objetivo general de la investigación; para alcanzarlo se utilizó, una metodología de tipo descriptiva y explicativa con recolección de información primaria, a través de una encuesta aplicada a los estudiantes del programa Administración de Empresas, luego se respaldó con fuentes secundarias para darle un mayor soporte a la investigación. 

En relación a la percepción, se identificó que la gran mayoría de estudiantes, tiene interés por la investigación, pero no quiere asumir responsabilidades y compromisos que emanan de este proceso extracurricular; también señalan que pertenecer a los semilleros es complejo porque demanda poseer diversas competencias que requiere la investigación; no obstante, es importante resaltar que los estudiantes reconocen que este escenario contribuye en su formación profesional y los hace competitivos para afrontar el mundo laboral.
Evaluation of Surfactant Application to Increase Oil Recovery in Bottom Aquifer-Driven Naturally Fractured Reservoir
Authors: Alakbarov Samir , Behr Aron
Published: September 2019

As means of primary and secondary recovery, the fractured reservoirs with strong aquifer can be developed either by water injection or by utilizing the natural energy of the aquifer itself. High permeability contrast between fracture and matrix blocks and preferably mixed to oil-wet nature of the naturally fractured reservoirs makes waterflooding and primary methods of production mostly inefficient leaving vast amount of oil unrecovered in the oil-bearing matrix blocks. Due to the absence of a sufficient pressure gradient, wettability of the reservoir rock determines the rate of the displacing fluid invasion into the matrix blocks by capillary and gravity forces. Chemical Enhanced Oil Recovery (cEOR) mechanisms are aimed to intensify oil recovery by affecting these forces. Laboratory and field pilot tests showed the application of surfactant to be a promising cEOR agent for increasing oil recovery from the matrix blocks, both in water-wet and oil-wet fractured reservoirs. For the case studied in this paper, analysis of the surfactant application in the fractured reservoir required the solution of the following challenges: –Interpretation and reproduction of the EOR mechanisms by mathematical modelling–Adaptation and integration of the EOR effects into the full field model–Development of the proper technology for surfactant injection under the given reservoir conditions

The aim of the paper is to present the discussions and the workflow for analyzing and identification of the surfactant application in the fractured reservoir with strong bottom driven aquifer.

Introduction of the trapping number (accounting the capillary and Bond numbers) as a scaling parameter enabled to evaluate the combined effect of capillary, viscous and gravity forces on oil desaturation. To integrate the trapping number into commercial simulator, a special interface was developed within the scope of this work. The EOR effects of surfactant were evaluated on the single porosity numerical models representing a discretized matrix block.

To upscale the specific recovery mechanism as a mass exchange term into full field dual porosity model a special coupling solution was introduced. A pseudo-capillary pressure is suggested as an intermediate function to translate the recovery mechanism from single to dual porosity model.

The developed innovative technology proposes a special injection and production strategy for more effective areal sweep efficiency as well as alteration of injection water chemistry to drive the surfactant into target areas without high losses into the aquifer.

This technology and the described workflow, both were employed for advanced estimation of surfactant EOR potential in a naturally fractured carbonate reservoir. The surfactant aided recovery mechanism based on transition from capillary to gravity dominated displacement showed enhanced effect on ultimate oil recovery from this reservoir.
Robust Characterisation Methods of Cuttings Derived from Siliciclastic Reservoir and Seal Rocks - A Case Study from New Zealand
Authors: AlJallad Osama Ali , Grader Abraham , Koronfol Safouh
Published: September 2019

Even though coring of rocks is the best way to characterize reservoir and source rocks geologically and petrophysically, this method is considered expensive, having a relatively high cost per foot. Alternatively, side-wall cores and cuttings are widely used in reservoir characterization at a relatively low cost. However, this method has limitations related to cuttings bad physical conditions, size, mixed lithological and mineralogical characteristics which make the commonly used conventional evaluation methods not applicable. This study introduces a robust combination of digital and conventional core analysis methods to overcome these limitations and characterize reservoir and shale cuttings derived from two hydrocarbon-bearing formations in New Zealand.

Initially, all cuttings from both formations were screened based on their cutting sizes and later based on the visually observed textures using the stereomicroscope. This helped in selecting representative cuttings for the main identified textures. These cuttings were CT imaged at a resolution ranging from 40 to 4 microns/voxel resolution in order to confirm their rock textures and sedimentary structures for better characterization results. Next, mercury injection capillary pressure (MICP), X-ray diffraction (XRD), and petrographical analysis were conducted on all selected cuttings with different rock textures in order to understand the pore types, textural variations, diagenetic overprints and mineralogy of the cuttings samples. Then, they were scanned at optimum resolutions using Micro CT and 3D FIB-SEM microscopies. Finally, all acquired images were segmented digitally and 3D rock volumes were created. These volumes were used in computing porosity, permeability, formation factor resistivity (FRF) and poroperm trends digitally using numerical simulation techniques.

Conventional and digital rock analysis showed that the cuttings derived from the reservoir interval are composed of an argillaceous sandstone with a very good computed porosity (18% up to 31%) and permeability (30 to 200 mD). On the other hand, the cuttings derived from the shale source rock interval, which were predominately composed of clay minerals, have a computed porosity of 12% to 13% (mainly inorganic pores) and an absolute permeability in the range of 0.5 to 4 Micro-Darcy. The digital poroperm trend analysis identified distinct poroperm trends for each formation which helped in understanding their petrophysical aspects.

This integration between conventional and digital methods provided better geological and petrophysical understanding of both formations using a limited number of cuttings, less cost and time.
Characterization of Channelized Systems in a Carbonate Platform Setting: A Case Study on the Late Cretaceous Reservoir from the Supergiant Oilfield, Iraq
Authors: Al-Ali Ali , Stephen Karl , Shams Asghar
Published: September 2019

Identification of tidal channels fairways is key for predicting behavior of areas at higher risk to water breakthrough or otherwise have a significant impact on the development and monitoring of reservoir performance. However, tidal channels in carbonates are not often easily characterized using conventional seismic attributes. It is important to decipher the complexity of the carbonate tidal channel architecture with integrated multisource data and a variety of approaches.

In this paper, petrological characteristics and petrographic analysis is conducted on well logs and validated carefully using core data. Then, the second step is to compare the carbonate channel systems with modern analogue in Bahama tidal flat and outcrop scales in Wadi Mi'Aidin (Northern Oman). Thereafter, the supervised probabilistic neural network (PNN) and linear regression method were undertaken to detect an additional channel distribution.

The relationship of high porosity with low acoustic impedance appeared mostly in the channel facies which reflects good reservoir quality grainstone channels. Outside these channels, the rock is heavily mud filled by peritidal carbonates and characterized by a high acoustic impedance anomaly with low quality of porosity distribution. The new observation of PNN porosity volume revealed a lateral distribution of the Mishrif carbonate tidal channels in terms of paleocurrent direction and the connectivity. Additionally, the prior information from core data and the geological knowledge indicate a good consistency with classified lithology. These observations implied that Mishrif channels consist of a wide range of lithology and porotype fluctuations due to the impact of depositional environment.

The work enables us to provide a new insight into the distribution of channel bodies, and petrophysical properties with quantification of their influence on dynamic reservoir behavior of the main producing reservoir. This work will not only provide an important guidance to the development and production of this case study, however also deliver an integrated work path for the similar geological and sedimentary environment in the nearby oil fields of Southern Iraq.
Modelling Dispersed Chemical Droplets Injection in the Gas Stream for EOR Applications
Authors: Valencia Juan D. , Mejía Juan M. , Ocampo Alonso , Restrepo Alejandro
Published: September 2019

This paper address the numerical simulation of the chemically enhanced gas injection technology (ChEGas-EOR) at core and reservoir scales. In this technique, a liquid chemical solution, having engineered properties, is sprayed along with the gas stream. The mist travels through the wellbore and further introduced in the reservoir. Previous lab tests, pilot studies in light & intermediate oil reservoirs indicate that the application of CheGas-EOR allows for a reduction in operational costs, increases the chemical penetration radii and decreases the retention rate in the rock. However, the associated uncertainty is still too high to develop this process on a productive scale. In this work we use a developed phenomenological model to build a tool that assist in design and evaluation of Chemical Gas EOR operations aiming to reduce the uncertainties and optimize oil recovery.

We developed a mathematical model, based on the most important transport and surface phenomena. Non-equilibrium mass transfer between phases during the interception of the chemical solution droplets with the liquid phases. Active chemical concentration in miscible liquid phases is much lower than liquid-based chemical injection opperations. As a consequence, dissolution and adsorption rate of active chemicals with reservoir rocks are slow. The model is base on the extended black-oil model formulation coupled to local mass balance equations of active chemicals. Non-equilibrium mass transfer processes are represented with interception, dissolution and a first order kinetic sorption models.

The model was adjusted and then validated using experimental data from core-.floodint tests. Good agreement of the simulations results with experimental observations were obtained. The model can predict the relevant behavior of the disperse chemical injection in the gas phase in porous media. Also, well injections simulations at reservoir scale using the matched parameters from laboratory, reproduced pilot field results. Simulation experiments predict that the CheGasEOR process can increased substantially the oil recovery factor.

For the first time, a model for disperse chemical injection for EOR applications is developed and validated at core and reservoir scale. The simulation model allows the evaluation of this technology at different scales. Therefore, it is possible to use it to optimize operating conditions and perform sensitivity analysis for field applications.
Giant Field Development Optimisation with the Consideration of Regional Voidage Replacement Ratio
Authors: BaniHammad Najoud Hassan , Kedia Rachit , AlSabeai Jawaher
Published: September 2019

Net present value (NPV) and voidage replacement ratio (VRR) are the key drivers to define an optimal reservoir development strategy that maximizes returns while maintaining reservoir health. In the subsurface context, maximizing NPV consists of optimizing the well locations. Voidage replacement ratio (VRR), which is defined as the ratio between the volume of injected fluid and the volume of produced fluid, measures the rate of change in reservoir energy. Conventionally, operators try to maintain a VRR close to one during the whole field life. Typically a single value of VRR is used as a metric to represent the whole reservoir. However, this approach does not capture the lateral variation in pressure seen in giant fields.

This paper focuses on a more suitable method for determining the VRR for each user-defined pressure region using reservoir simulation. This method is used to plan the location of future wells during the long term development plan and maximize NPV and recovery. Two scenarios of well location will be examined. The first scenario consists of optimizing well location using a single VRR metric for the whole field. The second scenario uses the VRR from each pressure region to decide on the optimum number of wells per region.

This latter approach is shown to give better results in planning well location for future field development and is consistent with the reservoir pressure distribution across the field.
Perched Water - Identification and Production Behavior In A Real Case
Authors: Macaluso Daniela , Colombi Nazzarena , Castelnuovo Luca , Calderoni Mirko , Prevosti Paolo Battista
Published: September 2019

Unexpected water accumulation (called perched water) can be present inside hydrocarbon bearing reservoirs. In case of limited or poor geophysical data, the prediction of this accumulation may be difficult.

In this paper, a real case is used to show how the presence of perched water was initially supposed and then verified through production data analysis.

During the development campaign of a deep water reservoir in West Africa, a water injector well found an unexpected shallower water table. To understand the nature of this water, the gas while drilling data of two oil producer drilled in the same area of the water injector were analysed. Based on this analysis the last meters of the open hole section of both oil producers were in water. The integration of gas while drilling data, stratigraphy, sedimentology and structural settings knowledge of the area suggested that this water was locally trapped during oil migration, most likely due to the presence of a structural barrier.

The two oil producer wells, located in the supposed perched water area, were successfully started-up. The behavior of both wells was daily monitored to understand and confirm the nature of perched water phenomenon. From day one, the two wells showed water production. After few weeks, the water cut of one well clearly started to reduce. For the other well, the water cut behavior was constant and only after one year of production the declining trend was appreciated. The observed declining trend of water production was the final confirmation that aquifer in this sector of the field is isolated and with limited extension. The water cut trend was also captured in the 3D dynamic reservoir model. In addition, tracers were implemented in the model to identify different water production sources (injected or perched) and to forecast their evolution during the field life.

The literature on perched water is quite limited and usually this kind of phenomenon is detected and described only on the geological side, but the production behavior of this water is rarely observed. This case study is integrating the geological and geophysical knowledge of the field with production data analysis to understand perched water behavior and can be considered a reference for other similar situation.