53 research outputs found
Illuminating Strain Fields Generated by Hydraulic Fracturing: from Modeling of Fiber-Optic Response to Fracture Geometry Inversion
The use of fiber-optics in reservoir surveillance can bring valuable insights to fracture geometry and fracture-hit identification, stage communication, and perforation cluster fluid distribution in hydraulic fracturing processes. However, the complexity of multiple information streams associated with realistic field data makes interpretation challenging for engineers and geoscientists. In this work, I generate distributed strain sensing (DSS)/low-frequency distributed acoustic sensing (LF-DAS) synthetic data of a cross-well fiber deployment. This data incorporates the physics governing hydraulic fracturing treatments. Forward modeling streamlines the interpretation task by exploring data richness, which has the potential to improve completion design and optimize production.
Forward modeling relies on analytical and numerical solutions. The analytical solution is developed by coupling two models: a 2D fracture (e.g., Khristianovic-Geertsma-de Klerk [KGD]) and Sneddon’s induced stress. DSS is estimated using the plane strain approach that combines calculated stresses and rock properties (e.g., Young’s modulus and Poisson’s ratio). In turn, the numerical solution is implemented using the displacement discontinuity method (DDM) with net pressure and/or shear stress as the boundary condition. In this case, the fiber gauge length concept is incorporated deriving displacement (i.e., DDM output) in space to obtain DSS values. In both methods, LF-DAS is estimated by the differentiation of DSS in time.
My simulator models classic features present in field data including: the heart-shaped pattern from a fracture approaching the fiber, stress shadow, and fracture hits. Incorporating shear stress in simulation creates strain time histories that entail complexities beyond those observed in cases in which tensile stress is the unique failure mechanism, thus highlighting the significant impact promoted by natural fractures. Moreover, a large gauge length (i.e., popular 10 m size used in the field) can mask strain data richness, distorting intrinsic characteristics of fracture systems. Fracture corridor extension signature, occasionally observed in LF-DAS field data when pumping stops, is verified in synthetic results for small pressure drop gradients, revealing that fractures continue to propagate in this scenario. Quantitatively, fracture geometry characterization is improved by estimating width in multiple locations as time increases, with the support of deep learning (DL) algorithms I developed using data from multiple monitor wells.
The model framework captures a wide range of relevant phenomena and provides a solid foundation for generating accurate and rich synthetic data representing multiple distinct scenarios leading to interpretation optimization. Also, the development of specific packages (commercial or otherwise) that explicitly model DSS/LF-DAS, incorporating the impact of fracture opening and slippage, is still in its infancy. This project is novel in this regard, and it opens new avenues of research and applications of synthetic DSS/LF-DAS in hydraulic fracturing processes
Organizational cultures: Obstacles to women in the UK construction industry
The global economic downturn coupled with recent changes in UK law have led to a sizable reduction in public sector funding. As a result, both public and private sector organizations are under greater pressure to provide evidence of their activities in promoting equality and diversity in their use of public sector funds. This requirement poses a particular challenge for the UK construction industry, which remains largely White male dominated. Empirical data gathered from a series of semistructured questionnaires and focus groups that have received managerial and soft skills training are analyzed and discussed in this article in an effort to establish the organizational cultural obstacles that women face in working in the UK construction industry. The findings outline that White male-dominated organizational cultures, inflexible work practices, and a lack of supportive networks serve as obstacles to women in the UK construction industry. This study concludes with recommendations for the expansion of training opportunities for women to encourage workforce diversity within the UK construction industry
Detector Analógico De Borda De Imagem Em Video
Novo equipamento eletrônico, portátil, alimentado preferencialmente por bateria, utilizado para medir a variação entre pontos de maior contraste em um trecho de uma linha do sinal de vídeo que compõe a imagem na tela, o qual permite medir ou detectar o movimento de um objeto, cuja imagem em vídeo apresente bordas em contraste, como, por exemplo, medir o comprimento ou o tamanho de células durante sua contração em estudos fisiológicos.BR0300834 (A)G06T7/20G06T7/20BR20030300834G06T7/20G06T7/2
Microfluorìmetro Simplificado Para Estudo De Cálcio Intracelular
Compreendendo um sistema óptico, que é dividido em três subsistemas, sendo o primeiro identificado como subsistema de excitação; o segundo como subsistema de monitoração e o terceiro como subsistema óptico de detecção.BR9705280 (A)G01N21/17G01N33/48G01N21/17G01N33/48BR19979705280G01N21/17G01N33/48G01N21/17G01N33/4
BINGO-ABDUS: a radiotelescope to unveil the dark sector of the Universe
we review the Baryon Acoustic Oscillations from Integrated Neutral Gas
Observations (BINGO) telescope, an international collaboration, led by Brazil
and China, aiming to explore the Universe history through integrated
post-reionization 21cm signals and fast radio emissions. For identifying
individually fast radio sources, the Advanced Bingo Dark Universe Studies
(ABDUS) project has been proposed and developed and will combine the current
BINGO construction with the main single-dish telescope and stations of
phased-array and outrigger.Comment: 23 pages, work presented in Syros, Greece, September 2022, to appear
in Springe
Estudo de Torre de Vento: Ensaio em Túnel de Vento em Edificações Residenciais
The adoption of natural ventilation to replace mechanical ventilation can contribute to reducing the residential consumption of electrical energy. Among the possible solutions is the use of windcatchers, an ancient architectural solution from the Persian people, for the conditioning of indoor environments, reducing the energy consumption and reaching efficient levels of thermal comfort. Windcatchers applied to the buildings can function through the differences of wind pressure that affect the facade or due to temperature variation: cold air enters through an opening, cooling the interior of the room and pushing hot air out of the building. The development of the work followed the methodological steps: 1) determination of the reduced models, 2) definition of the test parameters, 3) sensor programming and 4) wind tunnel test. The results obtained in the wind tunnel made it possible to evaluate the best windcatcher configuration for each case, aiming to reduce the internal temperature of the environments. In addition, it was possible to conclude that the temperature variation of 0.5 ° C achieved can contribute to the reduction of electricity consumption and, at the same, time preserve or increase the thermal comfort of users.
La adopción de la ventilación natural como sustituta de la ventilación mecánica puede contribuir a reducir el consumo de electricidad del hogar. Entre las posibles soluciones está el uso de torres de viento - la solución arquitectónica original del antiguo pueblo persa - para el acondicionamiento de ambientes internos, reduciendo el consumo de energía con ganancias significativas en bienestar termal. Las torres de viento aplicadas a los edificios pueden funcionar como consecuencia de la diferencia de la presión del viento en la fachada o debido a la variación de la temperatura: el aire frío entra por una abertura, enfriando el interior del lugar y empujando el aire caliente fuera del edificio. El desarrollo de los trabajos se dividió en las siguientes etapas metodológicas: 1) determinación de los modelos reducidos, 2) definición de los parámetros de prueba, 3) programación de los sensores y 4) pruebas en un túnel de viento. Los resultados obtenidos en el túnel de viento permitieron evaluar la mejor configuración de torre de viento para cada caso, con el objetivo de reducir la temperatura interna de los ambientes. Además, fue posible concluir que la variación de temperatura de 0,5°C lograda puede contribuir a la reducción de consumo de energía y al mismo tiempo preservar o ampliar el bienestar térmico de los usuarios.A adoção da ventilação natural em substituição à ventilação mecânica pode contribuir para a redução do consumo de energia elétrica das residências. Dentre as soluções possíveis está a utilização de torres de vento, solução arquitetônica original milenar do povo persa, para o condicionamento de ambientes internos, reduzindo o consumo de energia com ganhos significativos no quesito do conforto térmico. As torres de vento aplicadas à s edificações podem funcionar como consequência da diferença de pressão do vento que incide na fachada ou devido à variação de temperatura: o ar frio entra por uma abertura, refrigerando o interior do local e empurrando o ar quente para fora do edifício. O desenvolvimento do trabalho foi dividido nas seguintes etapas metodológicas: 1) determinação dos modelos reduzidos, 2) definição dos parâmetros de ensaio, 3) programação de sensores e 4) ensaio em túnel de vento. Os resultados obtidos no túnel de vento permitiram avaliar a melhor configuração de torre de vento para cada caso, visando reduzir a temperatura interna dos ambientes. Além disso, foi possível concluir que a variação de temperatura de 0,5°C alcançada pode contribuir para a redução de consumo de energia elétrica e ao mesmo tempo preservar ou ampliar o conforto térmico dos usuários
The BINGO Project IX: Search for Fast Radio Bursts -- A Forecast for the BINGO Interferometry System
The Baryon Acoustic Oscillations (BAO) from Integrated Neutral Gas
Observations (BINGO) radio telescope will use the neutral Hydrogen emission
line to map the Universe in the redshift range , with
the main goal of probing BAO. In addition, the instrument optical design and
hardware configuration support the search for Fast Radio Bursts (FRBs). In this
work, we propose the use of a BINGO Interferometry System (BIS) including new
auxiliary, smaller, radio telescopes (hereafter \emph{outriggers}). The
interferometric approach makes it possible to pinpoint the FRB sources in the
sky. We present here the results of several BIS configurations combining BINGO
horns with and without mirrors ( m, m, and m) and 5, 7, 9, or 10 for
single horns. We developed a new {\tt Python} package, the {\tt FRBlip}, which
generates synthetic FRB mock catalogs and computes, based on a telescope model,
the observed signal-to-noise ratio (S/N) that we used to compute numerically
the detection rates of the telescopes and how many interferometry pairs of
telescopes (\emph{baselines}) can observe an FRB. FRBs observed by more than
one baseline are the ones whose location can be determined. We thus evaluate
the performance of BIS regarding FRB localization. We found that BIS will be
able to localize 23 FRBs yearly with single horn outriggers in the best
configuration (using 10 outriggers of 6 m mirrors), with redshift ; the full localization capability depends on the number and the type of
the outriggers. Wider beams are best to pinpoint FRB sources because potential
candidates will be observed by more baselines, while narrow beams look deep in
redshift. The BIS can be a powerful extension of the regular BINGO telescope,
dedicated to observe hundreds of FRBs during Phase 1. Many of them will be well
localized with a single horn + 6 m dish as outriggers.(Abridged)Comment: 12 pages, 9 figures, 5 tables, submitted to A&
O Varroa destructor e suas implicações nas abelhas Apis melliferas.
Com o passar dos anos, o franco desenvolvimento e evolução do sistema alimentar tem garantido o acesso à alimentação básica em todo o planeta e a apicultura tem exercido papel-chave neste processo. Por conta da polinização de plantações agrícolas e também do fornecimento de produtos derivados do mel, as abelhas têm sido cada vez mais estudadas na área de sistemas agroindustriais para que se garanta a sobrevivência e produtividade de suas colônias. Atualmente um dos principais desafios para garantir a saúde das colônias é o enfrentamento do ectoparasita Varroa destructor. Este ácaro tem sido o principal vilão para as abelhas melíferas ocidentais por conta de suas características parasitárias, seu ciclo de reprodução e principalmente por ser vetor de transmissão de diversas doenças. Os apicultores utilizam diversas técnicas e práticas para redução ou erradicação de ácaros, como métodos apícolas biotécnicas, acaricidas sintéticos e acaricidas orgânicos ou suaves, e novos desafios surgem de acordo com a abordagem escolhida para o tratamento. São frequentes os relatos de contaminação do mel, exposição das abelhas a acaricidas em doses subletais, evolução genética dos ácaros a determinados acaricidas, entre outras adversidades. A continuidade de estudos de campo e laboratoriais são determinantes para que as práticas dos apicultores quanto ao enfrentamento ao Varroa seja efetivo e não produza efeitos colaterais a longo ou a curto prazo
Effect of traditional resistance training on blood pressure in normotensive elderly persons: a systematic review of randomized controlled trials and meta-analyses
Inclusivity : understanding the careers of women in the construction industry
The UK construction industry has a poor record of attracting, recruiting, training, and retaining women in the construction workforce at both operative and professional levels. Despite the need for a more balanced and inclusive workforce, the industry has failed to deliver on good intentions and promises. The workforce is male dominated and shows little enthusiasm for change. The research aim is to consider why, despite years of public and private sector initiatives, there has been no significant change in the numbers of women working in the construction industry. It considers the relationship between women and work and the construction industry, investigating how women are, and can be encouraged to become a part of the industry. Three research propositions were postulated: Firstly, the use of the term "women in construction" is too generic. It fails to recognise the heterogeneity, and the age stratification of women in the labour market. Women have different aspirations, motivations and responsibilities at various times during their careers that need to be recognised if they are to be encouraged, and retained in the construction industry and the allied professions. Secondly, the government acts as a facilitator for change in promoting gender equality and inclusivity. It aims to encourage and legislate to make the workforce more inclusive, but despite many initiatives, they have failed to make a Significant difference to the number of women working in the UK construction industry. Lastly, there is a potential conflict between the ideals of gender equality and inclusivity with the business case in the construction sector. The propositions were considered by the use of eleven collective multiple-case studies and five singe-case studies, selected to investigate this complex issue. The aim was to understand, explore and interpret women's 'lived experience' of their careers. The conclusions were a timeline model showing the many issues women face over the duration of their careers whilst considering a career in the construction sector. There have been many good initiatives by the governments since 2000 offering incentives to both employers, and for women to gain qualifications and work experience. Despite the declared success of the programmes, little has changed; there has been no discernable increase of women in the construction sector. The thesis makes recommendations about the issues influencing the decision to pursue a career in the sector and the changes that will need to be made. The "leaky pipeline" concept shows the importance of not just recruiting women into the workforce, but retention and progression must have a high priority. Career and life style are very important to women, blended with the importance of the family. Age was not a barrier to entry, not even for returnees returning to the world of work. The fundamental contribution to knowledge is a development model of women's career timelines based on the "leaky pipeline concept". A method of standardising the timeline was developed and tested using a combination of an established lifeline coding system and a career stage model developed from past research. The findings have demonstrated that economic, historic, social, legal, and political contexts facilitate opportunities for women's initiation into the construction trades and professions. The presumption has been that women in construction are a homogeneous group and join the industry as a school leaver or returnee, the development model has shown that this assumption is not correct.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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