bluuebunny/crossref_metadata_2025 huggingface dataset:
ON A MODEL OF OPTIMAL TEMPERATURE CONTROL IN HOTHOUSES
Authors: Astashova I. V. , Lashin D. A. , Filinovskiy A. V.
Published: October 2020

While growing plants in industrial hothouses it needs to keep the temperature according to round-the-clock graph at the point of growth of plant located at the fixed height. Only small deviations are admitted. To obtain this it is possible to increase the temperature by heating the floor and to decrease the temperature by opening the ventilator windows at the ceiling. We propose and analyse the model based on the heat equation. Physical sense of this problem is that at one end of the infinitely thin rod of length l (the height of the hothouse) we keep during the time T the temperature ϕ(t) (control function), while at the other end we have the given heat flow (t). It requires to find the control function ϕ0(t) such that the temperature at the fixed point c be maximally closed to the given temperature z(t). For the estimation of the control quality we use a quadratic integral functional.
ON SOME QUALITATIVE PROPERTIES OF THE OPERATOR OF FRACTIONAL DIFFERENTIATION IN KIPRIYANOV SENSE
Authors: Kukushkin M. V.
Published: October 2020

In this paper we investigated the qualitative properties of the operator of fractional differentiation inKipriyanov sense. Based on the concept of multidimensional generalization of operator of fractional differentiation in Marchaud sense we have adapted earlier known techniques of proof theorems of one-dimensionaltheory of fractional calculus for the operator of fractional differentiation in Kipriyanov sense. Along with the previously known definition of the fractional derivative in the direction we used a new definition of multidimensional fractional integral in the direction of allowing you to expand the domain of definition of formally adjoint operator. A number of theorems that have analogs in one-dimensional theory of fractional calculus is proved. In particular the sufficient conditions of representability of a fractional integral in the direction are received. Integral equality the result of which is the construction of the formal adjoint operator defined on the set of functions representable by the fractional integral in direction is proved.
REGION, RELIGION AND POLITICS PRESENTED ON RADIO BY PROFESSOR MANDICA MANJA KOVAČEVIĆ, PH.D.
Authors: Draženko Tomić , Legac Vladimir
Published: October 2020

Doctor Mandica Manja Kovačević (1929–2011) was a professor at several Croatian teacher training colleges (Čakovec, Kutina, and Gospić) and the author of three books and some 60 papers in various journals. She moderated a weekly ten-minute program for the local radio station in Gospić in the first decade of the 21st century. Thus, more than 300 radio contributions were produced, of which seventy were published in the book “Life on the Highest Wave” (Gospić, 2010). By researching and presenting phonographic recordings not included in the aforementioned book, this paper focused on the topics dealing with the affairs from the Croatian society in the first decade of the 21 century serving as an original sample by means of which Professor Kovačević had presented her personal views and attitudes resulting from life experience and local and traditional expectations. Professor Kovečević’s original reviews have attracted the attention of a large number of listeners because they have been able to find answers to questions that are usually contemplated by a contemporary man torn apart between existential challenges and spiritual search.
STUDENT’S ATTITUDES TOWARDS CHILDREN WITH DISABILITY
Authors: Krausz Anita
Published: October 2020

Several studies have shown that integrated education has advantages in students’ social development and accepted attitude development (Meyer, Park, Grenot-Scheyer, Schwartz & Harry, 1998).  The studies about the integrated education had been traced for several decades, our research is based on the CATCH (Chedoke-McMaster Attitudes Towards Children with Handicaps Scale) questionnaire (Rosenbaum, 1985) which instrument had been used in several international studies as well (Tirosh, 1997; Vignes, 2008; Godeau 2010; Bosseart, 2011; De Laat, 2013, Schwab, 2017). Our major aim is to map the adolescent youth, their attitudes towards children with special treatment. The questionnaire was based on the three-component model of attitudes proposed by Triandis (1971). This 36-item, the self-administered scale was primarily paper-based, but our adaptation is placed on the online form. The participants of the study were 7th-grade students (N=99) The overall reliability of the test was satisfactory (Cronbach-α= 0,856). In the content analysis, we found two items that were significantly negative and four items which were not significant, those leaving the KMO= 0,809 (KMO>6), therefore suitable for factor analysis. The results show that, however in our sample, these three-component factors aren’t so clear, the test is reliable. There are some subtests that call for a revision, and we will need further researches to develop our assessment tool to make it more reliable and valid.
PERCEPÇÃO DOS PROFISSIONAIS DE ENFERMAGEM QUANTO AO TRABALHO EM EQUIPE
Authors: Valentim Lusinete Ventura , Luz Reginaldo Adalberto de , Costa Santos Luciana Soares , Noca Cell Regina da Silva
Published: October 2020

Objetivo: conhecer a percepção dos profissionais de enfermagem quanto ao trabalho em equipe. Método: estudo transversal, exploratório, realizado em um hospital geral de grande porte, privado, na cidade de São Paulo. Resultados: amostra composta por 63% de técnicos de enfermagem e 37% de enfermeiros. Quanto ao trabalho em equipe, 95% concordaram ter bom relacionamento entre pares, receberem ajuda quando atarefados e retribuí-la; 94,6% atendiam a campainha, mesmo não sendo sua. Quanto aos benefícios do trabalho em equipe, 99,1% concordaram que a colaboração entre colegas de trabalho facilitava a assistência; 94,6%, que diminuía o tempo de resposta às chamadas; 96,4%, que o resultado do trabalho em equipe era mérito coletivo. Conclusão: os profissionais de enfermagem reconheceram fatores favorecedores do trabalho em equipe, como bom relacionamento interpessoal e clareza nos objetivos da instituição, além dos benefícios propiciados, como o papel do enfermeiro no desenvolvimento e como facilitador dessa dinâmica de trabalho.

Descritores: Equipe de Enfermagem. Relações Interpessoais. Comportamento Cooperativo. Percepção. Trabalho.
ANÁLISE ESPACIAL DO RISCO DE ADOECIMENTO DA HANSENÍASE EM UM ESTADO DO NORDESTE BRASILEIRO
Authors: Araújo Kleane Maria da Fonseca Azevedo , Gomes Lidiane Cristina Félix , Lana Francisco Carlos Félix
Published: October 2020

Objetivo: analisar a distribuição espacial do risco para o adoecimento de hanseníase nos municípios do estado da Paraíba, Brasil. Método: trata-se de estudo ecológico de análise espacial. Foram incluídos casos novos de hanseníase residentes na Paraíba, registrados no Sistema de Informação de Agravos de Notificação de 2001 a 2016. Foi realizada análise espacial descritiva nos períodos de 2001-2008 e 2009-2016 do índice composto de indicadores epidemiológico e análise de dependência espacial por meio dos índices de Moran global e local. Resultados: foram registrados 12.134 casos novos no período estudado. Identificou-se no primeiro período clusters com classificação alto/alto nas regiões leste, oeste e noroeste. No segundo período, os clusters concentram-se nas regiões leste e sudeste e decresceu no oeste e noroeste. Conclusão: o risco para o adoecimento de hanseníase está presente nos municípios da Paraíba. A distribuição espacial é dessemelhante no estado. Ações de vigilância devem ser prioritárias para o controle da endemia.

Descritores: Hanseníase. Epidemiologia. Análise Espacial. Atenção Primária à Saúde.
„ANGYAL-FECSKELÁNYFIÚK”
Authors: CSEHY Zoltán
Published: October 2020

Bori Imre nevezetes Juhász Ferenc-tanulmányai már az 1960-as években különös alapossággal térképezték fel a költő világának alapmintázatait. Nem voltak híján a merész, poétikaközpontú megállapításoknak sem: ez az előadás is Bori Imre bátorságából merítve próbálja meg megközelíteni a Juhász-féle epikus nyelv kataklizmadiskurzusának tobzódó, önmaga anyagát minduntalan átszerkesztő, apokaliptikus tragikumát. Elsősorban Juhász úgynevezett époszaira, hömpölygő szövegkonglomerátumaira fókuszálok, s azokra a kérdésekre keresem a választ, hogy miként ölt mitikus, kozmikus és antropomorf formát Juhász szövegeiben a nemiség, az identitás átmenetisége, változó performanciája. Utólagos merészséggel ebbe a diskurzusba kerül bele a queer szemlélet néhány hasznosítható terminusa is (kivált Renate Lorenz ún. freak theoryja nyomán). Juhász szövegeinek nemi ambivalenciája a mitikusság pszichologizáló tendenciáiból eredeztethető, de több annál: az otthonosban rejlő más, a húsban lévő hiány, a köztes lét polgárjoga, a történelemformáló erők szétroncsolt szimbolizmusa, a történelmi és a pszeudomitikus térhasználat hatalmi agressziója tematizálódik benne. De, ami ennél is izgalmasabb, a teremtés szöveggeneráló aktusának önreflexív, költői formája is egyben.
Ensino de gêneros discursivos orais em livros didáticos de língua portuguesa
Authors: Storto Letícia Jovelina , Brait Beth
Published: October 2020

O objetivo deste artigo é analisar o trabalho com gêneros discursivos orais em livros didáticos de língua portuguesa, a fim de verificar como eles são tratados e como são direcionadas as atividades de produção textual oral. Como corpus, selecionamos e analisamos quatro livros (do 6º ao 9º ano) de uma coleção voltada ao Ensino Fundamental, anos finais. Os materiais observados foram aprovados pelo Programa Nacional do Livro Didático – PNLD (BRASIL, 2018, 2017). Notamos que a coleção analisada demonstra preocupação com o oral, mas ainda se ressente de embasamento teórico adequado e coerente para o trabalho com a oralidade em sala de aula.
Faktor Yang Mempengaruhi Konsumen Memilih Kolam Renang Muslimah Al-Hikmah Sport Center di Surabaya
Authors: Hardianto Anneke Ratnasari , Ratnasari Ririn Tri
Published: October 2020

The purpose of this study is to identify factors that influence consumers on choosing Al-Hikmah Sport Center Muslimah Swimming Pool in Surabaya. It related to increasing of people’s awareness to do physical activities, especially swimming.This study used quantitative research methods with exploratory factor analysis.Characteristics of the respondents in this study is Muslim consumers of Al-Hikmah Sport Center Muslimah Swimming Pool that have come at least twice in a last month. Sample amount on preliminary test by doing written interview are 20 respondents and the main test need 125 respondents. Sampling technique that used is non-probability sampling. Sampling was done using accidental sampling and purposive sampling.The results of the study showed that there are six factors that influence consumers on choosing Al-Hikmah Sport Center Muslimah Swimming Pool in Surabaya. The sixth factors are named by the factor of similarity motives, securities, location, facilities, water qualities, and the experiences.
Pengaruh Variabel Makroekonomi dan Variabel Spesifik Bank Terhadap Non Performing Financing Pada Bank Umum Syariah dan Unit Usaha Syariah di Indonesia Periode 2013-2014
Authors: Firmansari Daisy , Suprayogi Noven
Published: October 2020

This research attempt to analyze the effect of variable gross domestic product (GDP), inflation and financing to deposit ratio (FDR) to non performing financing (NPF) of Islamic Commercial Bank and Islamic Business Unit in Indonesia. This research using quantitative methods. The study is based on quarterly data for the period 2003-2014. Typed of data used are the secondary data from official website Indonesian Bank and Bureau Statistic Center. The analytical methods used in this study is the method of multiple linear regression with a significance level of 0,05.The result of this research indicate that gross domestic product and inflation partially provide a significant influence to non performing financing. Only financing to deposit ratio have an insignificant influence to non performing financing. However, gross domestic product, inflation and financing to deposit ratio simultaneously provide a signification effect to non performing financing.
APOIO SOCIAL: velhos da “UMA” em situação de vulnerabilidade em tempo de Covid-19
Authors: Noleto Leda Santa de , Osório Neila , Silva Neto Luiz Sinésio , Vilela Alessandra Oliveira , Anjos Alan Gomes dos
Published: October 2020

O presente estudo ilustra um relato de experiência acerca do eixo “apoio social”, com vistas ao auxílio e informação social, desenvolvido por meio do Projeto “UMAnizando em tempos de coronavírus”, criado pela Universidade da Maturidade (UMA) – Programa de Extensão da Universidade Federal do Tocantins (UFT). O objetivo primordial é garantir o bem-estar dos acadêmicos nesta fase de isolamento, devido ao Covid-19, considerando que as pessoas velhas são o principal grupo de risco no cenário global de pandemia. O projeto reúne profissionais de diversas áreas, a exemplo de gerontólogos, assistentes sociais, pedagogos, educadores físicos, mestrandos e acadêmicos dos cursos de Medicina, Nutrição e Enfermagem, que auxiliam e informam com o cunho social, os velhos da “UMA”, em situação de vulnerabilidade.
COVID-19 NA PERIFERIA DE CURITIBA: A Mobilidade Urbana como “termômetro” da desigualdade
Authors: Nogueira de Souza Marcelo , Silva Bega Maria Tarcisa
Published: October 2020

O artigo apresenta alguns resultados parciais da pesquisa de pós-doutorado do autor e analisa como as estratégias de enfrentamento da Covid-19 na periferia de Curitiba, adotadas pela Secretaria Municipal de Saúde, podem ser impactadas pela diminuição da mobilidade urbana pois, embora a redução dos serviços de transporte público seja uma estratégia relevante para limitar a disseminação do vírus, na prática, ela revelou-se como potencial catalisadora de uma transmissão descontrolada, por promover aglomerações, justamente nas regiões periféricas mais afastadas dos estabelecimentos de saúde com capacidade para atender os casos mais graves da doença
Association of COVID-19 Disease Severity with Transmission Routes and Suggested Changes to Community Guidelines
Authors: Wu Jianqing , Ping Zha
Published: October 2020

In the war against the COVID-19 pandemic, the world is experiencing severe resource constraints. Although transmission routes are well understood, we suspect that they cause different disease consequences. We evaluate them in different forms to understand how they affect infection rates and disease severity. In determining how they affect disease outcome, we evaluated target tissue vulnerability, functional role, defense mechanisms, viral concentration, infection vicinity to target vital tissue, and host factors. We found that direct lung infection is the most lethal transmission route followed by bronchi infection. Transmissions by physical contacts, foods, and blood by low viral concentration (as expected in normal human activities) pose lower or much lower risks unless the infection is followed by subsequent lung exposures. After adding transmission route, treatment timings, and improper treatments into the list of known risk factors, we found that death rate and disability rate for young or healthy persons are nearly zero. We show that population based medical model improperly shifts nominal death rate from few vulnerable people to the population resulting in unnecessary population panic, and such panic is responsible for shutting down human activities and the world economy. Finally, we examined limitations in population-based mitigating measures and proposed for governmental and private adoption community guidelines, which are mainly to enable vulnerable people avoid exposures, prevent non-vulnerable people from serving as viral transmitters, get rid of high-risk exposure modes in working environment, improve safety for people in buses, ships and planes, and reduce death and disability rates for infected people.
Investigating the Potential of 8-Amidoquinoline Derivatives as a Fluorescent Probe for Zinc Detection: A Systematic Literature Review
Authors: Hassan Nurul Izzaty , Mohamad Nur Syamimi , Zakaria Nur Hanis , Daud Nurulhaidah , Tan Ling Ling , Ta Goh Choo , Heng Lee Yook
Published: October 2020

Abundant of preparatory works have recognized that fluorescent sensors based on 8-aminoquinoline are popular tools to detect Zn2+ ions in environmental and biological applications. Along with these studies, researchers started to introduce a variety of carboxamido group into an 8-aminoquinoline molecule in forming 8-amidoquinoline derivatives. Therefore, this systematic review aims to introduce a general overview of the fluorophore 8-aminoquinoline as Zn2+ receptors and to provide comparisons of collected studies that related to 8-amidoquinoline derivatives as fluorophore probe of the sensor. According to PRISMA systematic searches strategy, 13 articles were analyzed for trends, research designs, results and discussion, subject samples, and remarks or conclusions. We found cross-sectional studies with four aspects in zinc sensing that have been targeted; binding studies via titration, detection's limit, interferences studies, and validation of the study. Hence, this paper also included assessments of those criteria and the trends of development of 8-amidoquinoline derivatives based-zinc fluorescent chemosensor. It also showed that most of the researches conducted in China. In conclusion, this study identified various research designs of fluorescent chemosensors based on 8-amidoquinoline prolong with the effectiveness and potential as a recognition probe to assist the detection of zinc. Hence, elucidation of those derivatives essential to be explored because more studies are needed to improve the sensing criteria of the zinc sensor
Hypoxia Pathway Proteins are Master Regulators of Erythropoiesis
Authors: Watts Deepika , Gaete Diana , Rodriguez Diego , Hoogewijs David , Rauner Martina , Sormendi Sundary , Wielockx Ben
Published: October 2020

Erythropoiesis is a complex process driving the production of red blood cells. During homeostasis, adult erythropoiesis takes place in the bone marrow and is tightly controlled by erythropoietin (EPO), a central hormone mainly produced in renal EPO-producing cells. The expression of EPO is strictly regulated by local changes in oxygen partial pressure (pO2) as under deprived oxygen (hypoxia) the transcription factor Hypoxia Inducible Factor-2 induces EPO. However, erythropoiesis regulation extends beyond the well-established HIF-EPO axis, and involves processes modulated by other hypoxia pathway proteins (HPPs), including proteins involved in iron metabolism. The importance of a number of these factors is evident as their altered expression has been associated with various anemia-related disorders, including chronic kidney disease. Eventually, our emerging understanding of HPPs and their regulatory feedback will be instrumental in developing specific therapies for anemic patients and beyond.
Mechanical Simulation and Numerical Deduction for Volume Expansive-Prone Slag in a Rigid Matrix
Authors: Wang George
Published: October 2020

As the coproduct of steelmaking, steelmaking slag, volumetrically expansive-prone without treatment, has been satisfactorily used as an aggregate base course material in highway construction. Although numerous technical reports and papers have revealed that steel slag aggreged using in rigid matrixes, the end product, paving block, non-structural concrete, for example, possesses superb strength and durability properties, the application of steel slag aggregate as a concrete aggregate is currently prohibited in highway construction. Naturally, researchers explore the practicality of use of steel slag, how to connect the laboratory experiment results to the end-product behavior, and further convert the research results into real construction? For all nontraditional or secondary materials utilization, the procedure of laboratory material examination, lab and field trial test are critical. To generalize the utilization, usability criteria establishment is necessary. This paper tries to use step-by-step method and plain language to explain how the volumetrically expansion can be simulated in lab testing apparatus, and based on the model, the mathematical deduction can result in a numerical usability criterion for steel slag use as a coarse aggregate in concrete (a rigid material). Therefore the paper is composed four main parts, laboratory test methods to examine the expansion force resulted from steel slag; converting the measured expansion force in a given volume of mass aggregate to the expansion (body) force of a single particle; modeling of slag and end material disruption; and a usability criterion from numerical deduction for the use of expansive-prone coarse slag in concrete or other rigid matrices. The paper provides the solutions to answer the above questions. Through the mathematical and mechanical modeling, provides the potential criteria that could result in specifications and guidance establishment for broad volumetric expansive-prone slags.
Dynamics of System of Higher Order Difference Equations with Quadratic Terms
Authors: Taşdemir Erkan
Published: October 2020

This paper aims to investigate the global asymptotic stability of following system of higher order difference equations with quadratic terms: x_{n+1}=A+B((y_{n})/(y_{n-m}²)),y_{n+1}=A+B((x_{n})/(x_{n-m}²)) where A and B are positive numbers and the initial values are positive numbers. We also study the rate of convergence and oscillation behaviour of the solutions of related system.
Causal Association between Periodontitis and Parkinson's Disease: A Bidirectional Mendelian Randomization Study
Authors: Botelho João , Machado Vanessa , Mendes José João , Mascarenhas Paulo
Published: October 2020

Latest evidence revealed a possible association between Parkinson’s disease (PD) and periodontitis. We explored the causal relationship of this association through two-sample Mendelian randomization (MR) in European ancestry populations. To this end, we used openly accessible data of genome-wide association studies (GWAS) on PD and periodontitis. As instrumental variables for periodontitis, seventeen single-nucleotide polymorphisms (SNPs) from a GWAS of periodontitis (1817 periodontitis cases vs. 2215 controls) and forty-five SNPs from a GWAS of PD (20,184 cases and 397,324 controls). Eight non-overlapping SNPs of periodontitis from an additional GWAS assisted in the validation of association being studied. Multiple approaches of MR were carried-out. There was no evidence of genetic liability of periodontitis being associated with a higher risk of PD (B= -0.0003, Standard Error [SE] 0.0003, P = 0.26). The eight independent SNPs (B= -0.0000, SE 0.0001, P = 0.99) validated this outcome. We found no association of genetically primed PD towards periodontitis (B= -0.0001, SE 0.0001, P = 0.19). This MR study found no conclusive evidence to support a bidirectional causal genetic liability between PD and periodontitis. Further GWAS studies are needed to confirm the consistency of these results.
Long Range Transport of Southeast Asia PM2.5 Pollution to Northern Thailand during High Biomass Burning Episode
Authors: Amnuaylojaroen Teerachai , Inkom Jirarat
Published: October 2020

This paper aims to investigate the airflow that can transport emission sources of PM2.5 from neighboring countries to contribute to air pollution in northern Thailand. We applied the coupled atmospheric and air pollution model which is based on the Weather Research and Forecasting Model (WRF) and a Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT). The model output was compared to the ground-based measurement from the Pollution Control Department (PCD) to examine model performance. As a result of model evaluation, the meteorological variables fairly agreed well compared to observation with Index of Agreement (IOA) in ranges of 0.57 to 0.79 for temperature and 0.32 to 0.54 for wind speed, while the fractional bias of temperature and wind speed were 1.3 to 2.5 °C and 1.2 to 2.1 m/s. Burma was a country that contributed much of hotpot locations by 37% of the entire hotspot locations of Southeast Asia in March. The influence of the Asian Monsoon can bring pollutants from neighboring countries such as Burma and Laos toward northern Thailand in March that likely contribute to high concentrations of PM2.5 in northern Thailand.
Managed Pressure Drilling Influx Management: A Comprehensive Analysis of IME, MPD Operations Matrix, Dynamic Kick Tolerance Concepts, and Parameter Sensitivity
Authors: Gonzalez Luis Romar Alexandra , Bedoya Jorge , Cenberlitas Serkan , Bacon Will , Gabaldon Oscar , Brand Patrick R
Published: October 2020

Implementation of Managed Pressures Drilling (MPD) techniques provide substantial advantages for addressing difficulties in challenging wells. These benefits include not only the early influx and loss detection, but also Dynamic Influx Management. MPD provides the ability to circulate out an influx at drilling circulation rates while remaining within the primary well control barrier. Dynamic influx management is a trending topic within the industry, with its importance capturing the attention of planning and operational teams, regulatory bodies, and industry interest groups tasked with the development of recommended practices. Evolving from conventional kick tolerance to MPD kick tolerance has enabled dynamic influx management milestones, such as the adoption of the MPD operational matrix. More recently, the novel approach of the Influx Management Envelope (IME) has been increasingly adopted by the industry. This paper presents the state-of-the-art engineering analysis and operational considerations for dynamic influx management during MPD operations. As part of an integrated approach, this work considers three main aspects; 1) MPD kick tolerance, including concepts and its variables of interest, 2) IME generation and parameter sensitivity analysis, 3) generation of an MPD operational matrix. In addition, the advantages and disadvantages of various approaches to determining the limits of dynamic influx circulation are discussed.
Significant Surge and Swab Offshore Brazil Induced by Rig Heave During Drill Pipe Connections
Authors: Godhavn John-Morten , Olorunju Banzi , Gorski Dmitri , Kvernland Martin , Sant'Ana Mateus , Aamo Ole Morten , Sangesland Sigbjørn
Published: October 2020

This paper describes measured and simulated downhole pressure variations ("surge and swab") during drill pipe connections when drilling an ultra-deepwater well offshore Brazil on the Carcará field. Floating rig motion caused by waves and swell ("rig heave") induces surge and swab when the drill string is suspended in slips to make up or break a drill pipe connection and topside heave compensation is temporarily deactivated. This is a known issue in regions with harsh weather such as the North Sea, where pressure oscillations of up to 20 bar have been reported during connections. Recorded downhole drilling data from the Carcará field reveals significant pressure oscillations downhole (in the same order of magnitude as in the North Sea) each time the drill string was suspended in slips to make a connection in the sub-salt 8 ½" section of the well. Mud losses were experienced around the same well depth and they might have been caused by surge and swab.

Measured surge and swab pressure variations have been reproduced in an advanced proprietary surge and swab simulator that considers rig heave, drill pipe elasticity, well friction, non-Newtonian drilling mud, well trajectory and geometry. Moreover, findings in this paper suggest that surge and swab was in fact significantly higher than recorded by the MWD (Measurement While Drilling) tool. The true magnitude of surge and swab is not captured in the recorded MWD data due to low sampling frequency of the downhole pressure recording (one measurement every six seconds, a standard downhole pressure sampling rate used on many operations today).

This work shows that surge and swab during drill pipe connections on floaters may challenge the available pressure window for some wells even in regions with calm weather such as Brazil. Managed Pressure Drilling (MPD) is a technique that improves control of the downhole pressure. It is, however, not possible to compensate fast downhole pressure transients, such as heave-induced surge and swab, using MPD choke topside. This is due to the long distance between the choke and the bit, which translates into a time delay in the same order of magnitude as typical wave and heave periods. A downhole choke combined with continuous circulation is one of potential solutions.

Surge and swab during drill pipe connections can result in a loss or an influx and should be considered in the well planning phase when mud weight, section lengths, etc. are selected.
A Novel Deepwater Kick Control Strategy for Handling Riser Gas Unloading with Data-Driven Parameter Estimation
Authors: Gu Qifan , Fallah AmirHossein , Gul Sercan , Ashok Pradeepkumar , Chen Dongmei , van Oort Eric , Moore Dennis
Published: October 2020

Non-aqueous drilling fluids used in deepwater drilling operations are conducive to the dissolution of formation gas during wellbore influx events, increasing the risk of gas kicks going unnoticed. This can lead to hazardous riser gas unloading events if kicks are allowed to pass the subsea BOPs and come out of solution at the bubble point at shallow riser depth. One possible solution to handle and even prevent these events is to generate enough backpressure using Managed Pressure Drilling (MPD) with a Rotating Control Device (RCD) to keep the dissolved gas in solution. However, for large kicks, the required backpressure may exceed riser pressure limits.

A novel kick handling procedure using a dilution control strategy (DCS) is proposed here to handle gas influxes and subsequent gas unloading events. The idea behind this DCS is to inject mud into the riser through the boost line while simultaneously slowing down the circulation rate through the drillstring as the dissolved kick passes the open subsea BOPs. The kick will then get diluted and will be distributed across a larger annular space leading to a significantly decreased gas concentration that can be more easily handled by the MPD system with lower backpressure.

The feasibility of the DCS is investigated in this paper using a multi-phase flow model which is validated against experimental data for a gas kick in oil-based mud. Simulation results for a demonstration case show that a kick entering the well at 18,500 ft with 2,250 kg gas can be thoroughly eliminated with a 3:1 dilution ratio (which is the ratio of riser boost rate to drillstring circulation rate) with approximately 620 psi backpressure when using an MPD system. To improve the applicability of the proposed DCS procedure in field practice, a data-driven approach is implemented using simulated data points to provide a fast estimation of the optimum dilution ratio (DR) to control the kick in real-time.
Re Multi Fracturing with Flow Diverter
Authors: Amirov Marat Rimovich , Kuzakhmedov Rifat Maratovich , Boroday Aleksey Aleksandrovich , Kashtanov Ivan Gennadyevich , Yazkov Alexander Victorovich , Solovyev Vladimir Vladimirovich , Butkeev Andrey Sergeevich , Eliseev Petr Ilyich , Bagaev Aleksandr Nikolaevich , Fomin Ivan Sergeevich , Fedorov Georgiy Evgenievich , Bakirov Ruslan Rafailovich , Fomin Mikhail Vladimirovich , Fragachan Francisco E. , Cruz Cristian M. , Omer Mohammed , Brendin Mikhail Vladimirovich , Trofimov Denis Sergeevich
Published: October 2020

As of today, there are various methods of repeated multistage fracturing. Mostly, they are associated with the involvement of coil tubing and well workover services. These are assemblies with opening and closing frac sleeves, small-sized packers, twin packers, CT packers… All the methods are extremely costly in economic terms, the full operation cycle takes a long time and is associated with a high risk of hazards.

The above methods have an alternative that is not widely used. An alternative and universal method for the repeated MSF is a mechanical, degradable flow diverter. The diverter is a 2-component powder consisting of 7 and 100 mesh particles that can isolate the required open area in the wellbore.

The diverter has an extensive scope of application: it can be used for MSF in several vertical well zones, for MSF in wells with slotted liner completions, for repeated MSF in wells with sliding frac sleeves both in a blind version and with the use of a CT packer. It can be used for additional stimulation of missed, non-activated sleeves in sliding frac sleeve assemblies, as well as for the restoration of circulation, as temporary casing patches, etc.

The basic technology does not require any services in addition to hydraulic fracturing. It is also important to mention that it is completely soluble downhole, which means that additional expenditures for well completion after its use are not required.

In April 2020, the company performed repeated MSF using this flow diverter as a pilot job. As a result of the MSF, the well flow significantly exceeded the expected design values.

Prior to the MSF with a flow diverter, the well wireline logging was performed to determine the flow profile. After performing 3 fracturing stages, a repeated wireline logging confirmed the formation of new fractures in the new zones not stimulated previously.

By virtue of the fact that in these days the drilling rates have been significantly reduced, an urgent need to increase the flow rate of the existing wells appears. That is why high-quality, rapid and accessible repeated fracturing technology has great prospects and promises to become very popular among operators.
A Decade of Multi-Zone Fracturing Treatments in Russia
Authors: Astafyev Vladimir , Samoilov Mikhail , Fayzullin Ildar , Kuvshinov Igor , Mitin Alexey , Fedorov Georgy , Gaponov Mikhail , Ovchinnikov Kirill , Khusainov Ruslan , Fedorov Evgeny , Lushev Mikhail
Published: October 2020

Multistage hydraulic fracturing (MSHF) has given new impulse to the development of hydraulic fracturing market in Russia. This paper illustrates the evolution of horizontal well multi-zone stimulation methods for the past decade in Russia. Examples of multi-zone treatments using various technologies in different fields are given. Analysis of the work performed shows how the integration of modern drilling, completion, stimulation, control and production methods allowed cost-effective development of hard-to-recover reserves. The development of multi-zone well stimulation brought to the market new horizontal well completion, fracture mapping, production and field development control technologies. The article also evaluates potential development and application of multi-zone technologies.
Multistage Horizontal Wells Refracturing by Means of Abrasive Jet Perforation + Frac Technology
Authors: Shaykamalov Rustam , Gaponov Mikhail , Mukhametshin Marat , Bildanov Vladislav , Katermin Alexey , Bashirov Ildar
Published: October 2020

Since 2015, the technology of multistage fracturing (hereinafter MSHF) in horizontal wells has become widespread in Bashneft-Dobycha's fields. MSHF applies to newly-drilled and side-tracked wells (hereinafter ST wells). To date, more than 100 multifracked wells have been put on stream.

The post-MSHF well productivity decreases over time because of the degrading fracture conductivity and depletion of the reserves in the earlier stimulated zones. The most effective method to restore well productivity is refracturing, which was proven in directional wells.

For refracturing, the assemblies that contain frac sleeves activated by dropping the balls of various diameters are mostly used. For openhole isolation of intervals, annular hydraulic-set packers are normally used, without cementing a horizontal borehole section. The application of these MSHF assemblies makes it difficult to further perform interval-wise refracturing. The challenging factors include multiple open intervals after performing all the frac stages and the tight hole in the sleeve intervals, even if milled. One of the refracturing methods tested in Bashneft-Dobycha's horizontal wells was ‘blind’ fracturing. This is the most easy-to-use method, which is not time-consuming either. The effect of these jobs was low, as the most depleted intervals were refractured.

In 2019, a combined technology of abrasive jet perforation and subsequent refracturing through an abrasive jet perforating tool (abrasive jet perforation + fracturing) was proposed for multifractured horizontal wells. The application of the abrasive jet perforation + frac technology allowed for successful selective re-injection of acid and proppant into the selected intervals of the horizontal borehole. By now, Bashneft-Dobycha has refractured 10 multistage horizontal wells by means of the abrasive jet perforation + frac technology. One trip included three refrac stages maximum. All the treatment were successful, substantially increasing well productivity indices.
Integrated Approach to Multistage Fracturing Design
Authors: Andreev Alexey , Astafyev Vladimir , Samoilov Mikhail
Published: October 2020

With the advent of multistage hydraulic fracturing technology, the task of well completion optimization was added to the task of fracture design - selection of well length, number of stages, distance between frac ports. A common approach is to first design the fracture and then optimize well completions with approved fracture parameters. This paper considers an alternative approach where the well completion is selected first, including preliminary fracture parameters, and then the required proppant volume is estimated.

For this study, field data from a horizontal well with multistage fracturing were used. Tracer studies were conducted and the results were also used as input information. A reservoir model was then built and the fractures were simulated explicitly using an unstructured grid. The model was history matched, and using the resulting matched model, several scenarios with different well completions and fracture parameters were evaluated.

This approach represents a practical workflow, both in terms of field development as well as reliable fracturing modeling and flow rate estimation. The approach allows for the preliminary optimization of well completion, the selection of optimal fracture parameters and, eventually, the calculation of proppant volume.

In this paper, the technique is presented on a practical example of an operating well.
Violence–related injuries in a rapidly developing Middle Eastern country: A Retrospective Study from a Level 1Trauma Center
Authors: Mollazehi Monira , El-Menyar Ayman , Mekkodathil Ahammed , Consunji Rafael , Al-Thani Hassan
Published: October 2020

Background: Violence is a global public health problem leading to injuries, long-term physical, sexual or mental health problems and mortality. The burden of violence-related injuries remains understudied in the Arabian Gulf region. The present study aimed to describe the epidemiology of hospitalized violence-related injuries in Qatar.Methods: A retrospective analysis of trauma registry data from a level 1 trauma center was conducted by including all patients admitted to the hospital for violence-related injuries between June 2010 and June 2017. We analyzed and compared the hospitalized interpersonal and self-inflicted violence groups.Results: The hospitalization rate of violence-related injuries was 4.6 per 100,000 population per year; it was significantly higher in males (5.5/100,000 males/year vs. 1.8/100,000 females/year) and in younger populations, specifically in the 25-34 years age-group (41%). South Asians constituted 55% of the affected study population. Interpersonal violence (76.7%) was the most common mechanism of injury. Significant differences between interpersonal and self-inflicted violence were evident, especially for the type of trauma (i.e. blunt or penetrating), injured body regions, alcohol use, injury severity, need for intubation and psychiatric referral (p<0.05). Overall, in-hospital mortality was 6.4%; with a significantly higher rate in females (16% vs.5%, p=0.001). Outcomes, including length of hospital stay and mortality, were comparable in the two types of violence. Multivariate analysis showed that male gender and alcohol use were predictors for interpersonal violence whereas a high Injury Severity Score and a low Glasgow Coma Scale were predictors of hospital mortality.Conclusions: The rate of hospitalization for violence-related injuries in Qatar is low; however, its burden on the trauma system is of concern. Although it comprised only 9.6% of the study population, females are more likely to get hospitalized following self-inflicted injuries when compared to interpersonal violence. Disproportionate burden of violence in the South Asians and young population warrants an evidence-based public health approach in violence prevention to well address the risk factors.
A unique type of fully covered metal stent for the management of post liver transplant biliary anastomotic strictures
Authors: Warner Ben , Harrison Phillip , Farman Muhammad , Devlin John , Reffitt David , El-Sherif Yasser , Khorsandi Shirin E , Prachalias Andreas , Cerisuelo Miriam Cortes , Menon Krish , Jassem Wayel , Sriniva Parthi , Vilca-Melendez Hector , Heneghan Michael , Heaton Nigel , Joshi Deepak
Published: October 2020

Background: We report our experience of treating anastomotic strictures using a novel type of fully covered metal stent (FCSEMS). This stent, known as the Kaffes Stent, is short-length with an antimigration waist and is easily removable due to long retrieval wires deployed within the duodenum. Methods: 62 patients underwent ERCP and Kaffes stent insertion for post-transplant anastomotic strictures following confirmation of a stricture on MRCP. These patients were retrospectively analysed for immediate and long-term stricture resolution, improvement in symptoms and liver function tests (LFTs), stricture recurrence and complication rates. Results: Of the 56 patients who had their stent removed at the time of analysis, 54 (96%) had immediate stricture resolution and 42 continued to have long-term resolution (mean follow-up period was 548 days). Of the 16 patients with symptoms of biliary obstruction, 13 had resolution of their symptoms. Overall, there was a significant improvement in LFTs after stent removal compared to before stent insertion. Complication rates were 15% with only one patient requiring biliary reconstruction. Conclusions: The Kaffes stent is effective and safe at resolving post liver transplant biliary anastomotic strictures.
The effect of socioeconomic status among adult married females on informal caregiving for parents: Evidence from China
Authors: Wang Yi , Li Jiajia , Ding Lulu , Feng Yuejing , Tang Xue , Sun Long , Zhou Chengchao
Published: October 2020

Background: Married female caregivers face a higher risk of informal care burden. There is no study to explore the effect of socioeconomic status (SES) among married female caregivers on informal care intensity in China. The purpose of this study is to empirically examine how the SES of married female caregivers affects the amount of informal care they provide for their parents/in-law in China.Methods: 8 waves of the China Health and Nutrition Survey were pooled, and that the selection comprised only those women whose parents/in law had a need for care and were living in the same city. Informal caregivers were divided into three categories: non-caregivers (0 hrs/week), low-intensity caregivers (less than 10 hrs/week), and high-intensity caregivers (10 hrs/week and above). Chi-square tests and one-way analysis of variance (ANOVA) were used to compare the SES of the women between non-, low-, and high-intensity caregivers. Multinomial logistic regression analysis was used to calculate relative risk ratios (RRR) for various SES variables to assess the relation of SES on the likelihood of a low- and high-intensity caregiving in the household, adjusting for age, marital status, family characteristics and wave. Results: Of the 2741 respondents, high-intensity and low-intensity caregivers account for 16.42% and 21.38% respectively. Multinomial logistic regression result shows that the likelihood of being a high-intensity caregiver versus (vs.) a non-caregiver increases as the caregiver’s education attainment increases (p<0.05), and high income is related to the likelihood of being a high-intensity caregiver, but it is only significant at 10% level. Urban females are 1.34 times more likely than their rural counterparts to provide low-intensity care vs. no care (p<0.05) and are 1.34 times more likely to provide high-intensity care vs. no care (p<0.05). Employed females are 1.27 times more likely than those non-employed to provide low-intensity care vs. no care (p<0.05).Conclusions: Differences in SES are found between high-intensity caregivers and low-intensity caregivers. Women with high educational attainment and urban Hukou are more likely to provide high-intensity informal care, and women who are employed and with urban Hukou are more likely to provide low-intensity care.
Candida prevalence and oral hygiene due to orthodontic therapy with conventional brackets
Authors: Grzegocka Kinga , Krzyściak Paweł , Hille-Padalis Anna , Loster Jolanta E. , Talaga-Ćwiertnia Katarzyna , Loster Bartłomiej W.
Published: October 2020

Background: Conventional brackets are often used during orthodontic therapy of patients with malocclusion. The complex construction of such brackets greatly inhibits oral hygiene, which predisposes to increased carriage of microbiota. Orthodontic brackets could act as reservoir of yeast and predispose to oral candidosis. The aim of this study was to assess Candida prevalence and the role of oral hygiene during fixed appliance therapy. A further aim was to characterize the isolated yeasts according to their ability to form biofilms. Methods: Seventeen participants (average age 17 ± 7 years) were monitored by taking oral rinses and elastomeric ligature samples, and by evaluating the approximal plaque index (API) and gingival bleeding index (GBI) before and after placement of the orthodontic conventional brackets for twelve weeks. Isolated yeasts were counted and biofilm formation was evaluated. Results: One hundred and sixteen samples (67 oral rinses and 49 orthodontic elastomers) were collected. Ten patients (58.8% subjects) were Candida-carriers (two were colonized after bracket placement) and C. albicans was the most common species. The average number of yeasts in the oral cavity showed some fluctuation during the study, but in general had an upward trend (adj. R2 = 0.7967, p = 0.07025). A correlation was found between median number of yeasts and the periodontal indices (API, GBI). The average API values decreased in the Candida-carriers (adj. R2 = 0.95; p = 0.01709), while average GBI values increased in the noncarriers (adj. R2 = 0.92; p = 0.0256). Conclusions: Treatment with orthodontic appliances promotes Candida yeast colonization, which is variable over time in terms of strain and species, with dominance of C. albicans, and without increased biofilm-forming activity. The API value decreases over time in carriers, and the GBI value increases in uncolonized patients, which may have predictive significance for the development of oral candidiasis during orthodontic treatment.