bluuebunny/crossref_metadata_2025 huggingface dataset:
Responding to Complementary-Asset Discontinuities: A Multilevel Adaptation Framework of Resources, Demand, and Ecosystems
Authors: Cozzolino Alessio , Verona Gianmario
Published: January 2022

We examine how incumbent organizations respond to complementary-asset discontinuities — technological changes that introduce new manufacturing, distribution, and sales assets but leave the incumbents’ core knowledge preserved. To examine this increasingly common but relatively overlooked phenomenon, we conducted an inductive study of how six newspapers adapted to Internet distribution from 1995 to 2019. Our contribution is a framework that highlights three levels of adaptation (resources, demand, and ecosystem) with related mechanisms and necessary outcomes. At the resource level, incumbents adopt the new complementary assets according to the perception of synergies with their existing core knowledge. At the demand level, the extent to which incumbents update their beliefs about value creation depends on how much they experiment with customers. At the ecosystem level, higher experimentation in the ecosystem helps incumbents to update their beliefs about value capture. The research offers important implications for the technological change, strategic management, and business model innovation literature.
Partner with a Third-Party Delivery Service or Not? A Prediction-and-Decision Tool for Restaurants Facing Takeout Demand Surges During a Pandemic
Authors: Jia Huiwen , Shen Siqian , Ramírez García Jorge Alberto , Shi Cong
Published: January 2022

Amidst the COVID-19 pandemic, restaurants become more reliant on no-contact pick-up or delivery ways for serving customers. As a result, they need to make tactical planning decisions such as whether to partner with online platforms, to form their own delivery team, or both. In this paper, we develop an integrated prediction-decision model to analyze the profit of combining the two approaches and to decide the needed number of drivers under stochastic demand. We first use the susceptible-infected-recovered (SIR) model to forecast future infected cases in a given region and then construct an autoregressive-moving-average (ARMA) regression model to predict food-ordering demand. Using predicted demand samples, we formulate a stochastic integer program to optimize food delivery plans. We conduct numerical studies using COVID-19 data and food-ordering demand data collected from local restaurants in Nuevo Leon, Mexico, from April to October 2020, to show results for helping restaurants build contingency plans under rapid market changes. Our method can be used under unexpected demand surges, various infection/vaccination status, and demand patterns. Our results show that a restaurant can benefit from partnering with third-party delivery platforms when (i) the subscription fee is low, (ii) customers can flexibly decide whether to order from platforms or from restaurants directly, (iii) customers require more efficient delivery, (iv) average delivery distance is long, or (v) demand variance is high.
Evaluation of TPGU using entropy - improved TOPSIS - GRA method in China
Authors: Dong Hua , Yang Kun , Bai Guoqing
Published: January 2022

China is still one of the countries dominated by thermal power generation. In order to generate more efficient, stable and clean power, it is necessary to evaluate thermal power generation units (TPGU). Firstly, a comprehensive evaluation index system for TPGU with 20 secondary indicators was established from four aspects: reliability indicators, economic indicators, technical supervision indicators, and major operating indicators. Secondly, the entropy weight method can be used to calculate the weight of each second-level index. Mahalanobis Distance improved Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method is coupled with the Grey Relational Analysis (GRA), and the comprehensive evaluation values of 5 units (600MW) are respectively 0.4516, 0.5247, 0.3551, 0.5589 and 0.6168 from both vertical and horizontal dimensions. Finally, by comparing and analyzing this method with the above research methods, it is found that the results obtained by this method which re-establishes the coordinate system based on the data set are more accurate. In addition, this method can effectively evaluate the operation of TPGU, which is of great significance for cleaner production while generating electricity. In conclusion, some suggestions on clean production of TPGU are put forward, and the innovation points and limitations of this paper are pointed out.
Effects of non-pharmacological coping strategies for reducing labor pain: A systematic review and network meta-analysis
Authors: Chang Ching-Yi , Gau Meei-Ling , Huang Chi-Jung , Cheng Hao-min
Published: January 2022

Background

Facilitating the childbirth process is a global issue. Many strategies have been developed to cope with labor pain and improve the delivery experience and satisfaction of pregnant women. The results of different types of medical intervention on women’s expectant pain have been varied. Therefore, this systematic review was aimed at summarizing the body of evidence regarding the effects of various non-pharmacological coping strategies for reducing labor pain.

Methods

The review was conducted according to guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We systematically searched the articles published between 1989 and 2020 in six electronic databases: PubMed, MEDLINE, CINAHL, WOS, PsycARTICLES, and Airiti Library, and the reference lists of the Clinical Trial Registry. Twenty studies were identified, with eight eligible studies included in the Bayesian network meta-analysis.

Results

Eight studies with 713 participants were included in the meta-analysis with nine different non-pharmacological strategies for reducing labor pain. The traditional meta-analysis demonstrated that the non-pharmacological coping strategies were effective in reducing labor pain. Of these interventional strategies, the ranking probabilities analysis of the network meta-analysis suggested that the Bonapace Method may be the most effective strategy in reducing labor pain, followed by acupressure.

Conclusions

Non-pharmacological coping strategies can reduce labor pain while maintaining an effective and satisfactory delivery experience. This systematic review, by synthesizing the body of evidence, demonstrated that non-pharmacological coping strategies are effective in reducing labor pain. Furthermore, as demonstrated in the network meta-analysis, the Bonapace Method, modulating birth pain by involving the father, is the most effective non-pharmacological intervention for reducing labor pain.
The influence of family cohesion on self-regulation and anxiety problems among African American emerging adults
Authors: Augustine Danielle A. , Koss Kalsea J. , Smith Emilie P. , Kogan Steven M.
Published: January 2022

Although African Americans have lower rates of anxiety in childhood than other racial and ethnic minority groups, they seem to experience escalating rates during emerging adulthood. Despite this, few studies have examined factors associated with anxiety during emerging adulthood among African American populations. The current study investigated the extent to which late adolescent family relationships affect anxiety problems among African American emerging adults. Informed by family development theory, family cohesion was hypothesized to indirectly effect anxiety problems through self-regulation. This model was tested with three waves of data (ages 17, 19, 21) from African Americans participating in the Maryland Adolescent Development in Context Study. Study findings were consistent with the hypothesized model: family cohesion forecasted decreased anxiety problems, indirectly, via increased self-regulation. This finding suggests that families may be an important promotive process for anxiety problems during emerging adulthood. Prevention programs that target family processes may be able to reduce anxiety problems in emerging adult African Americans.
The experience of urgent dialysis patients with end-stage renal disease: A qualitative study
Authors: Lin Min-Ling , Chu Kuei-Hui
Published: January 2022

Purpose

Taiwan is among the countries with the highest global prevalence of chronic renal disease. However, when advised to undergo dialysis therapy, patients with end-stage renal disease often hesitate. Attitudes toward medication and Taiwanese cultures are the main reasons for this delay, and delay conditioning requires urgent dialysis. This study aimed to explore the experience of urgent dialysis patients with end-stage renal disease.

Methods

This study used a purposive sampling strategy with semi-structured interviews leading to in-depth interviews. Patients were recruited from the nephrology ward and hemodialysis center of a northern Taiwanese hospital. All participants were aged over 20 years with end-stage renal disease. Although advised by doctors to undergo dialysis, these patients delayed their treatment and later suffered severe complications. After emergency hospitalization, the patients’ condition improved. Data were analyzed by content analysis.

Results

Interviews with five participants suffering from end-stage renal disease identified six themes: “experiencing a sudden jolt,” “silent organ brings the most pain,” “feeling angry: why me?,” “facing a dilemma,” “taking risks,” and “facing consequences.”

Conclusion

These patients delayed their treatment and later suffered severe complications, even though doctors advised them to undergo dialysis. Health professionals play an important role in communication and coordination, assisting patients in coping with their situation. The analysis of the reasons for the delay in undergoing dialysis, therefore, should help health professionals provide proper guidance and care to patients who are faced with the decision to accept dialysis treatment.
Amnion bilayer for dressing and graft replacement for delayed grafting of full-thickness burns; A study in a rat model
Authors: Sandora Normalina , Fitria Nur Amalina , Kusuma Tyas Rahmah , Winarno Gammaditya Adhibarata , Tanjunga Sanjaya Faisal , Wardhana Aditya
Published: January 2022

Burn is a common case in developing countries, with over half of fire-related deaths reported in Southeast Asia and full-thickness burns as a high mortality risk. Human amnion has been used as a wound dressing for centuries. In this study, a decellularised amnion overlaid with fibrin, “amnion bilayer (AB),” was used as a dressing immediately after burn and as a graft to replace the scar in Sprague-Dawley rats subjected to full-thickness burn model. The aim was to observe whether amnion bilayer can reduce damages in third-grade burn when skin replacement is deemed impossible. The burn was induced using an electrical solder, heated for 5 mins, and contacted on the rat’s bare skin for 20 s. AB was applied as a (i) dressing immediately after induction and graft after eschar removal. Two groups (n = 6) were compared: AB and Sofra-Tulle ®, the National Hospital of Indonesia (NHI) protocol. Sections were stained with hematoxylin and eosin and Masson trichrome stains. Immunohistochemistry labelling was used to indicate scars (α-smooth muscle actin [α-SMA] and collagen-1) and angiogenesis (von Willebrand factor). Also, the macrophages inflammatory protein-3α (MIP-3α) indicates an early inflammatory process. The post dressing of the AB group demonstrated hair follicle remains and adipose tissue development. The NHI group appeared with a denatured matrix. Complete healing was seen in the AB group after 28 days with skin appendages similar to normal, while the NHI group showed no appendages in the centre of the actively inflamed area. The α-SMA was found in both groups. Collagen-1 was highly expressed in the NHI group, which led to a scar. Angiogenesis was found more in the AB group. The AB group had shown the capacity to accelerate complete healing and recover skin appendages better than the current protocol.
Multi-channel convolutional neural network architectures for thyroid cancer detection
Authors: Zhang Xinyu , Lee Vincent C. S. , Rong Jia , Liu Feng , Kong Haoyu
Published: January 2022

Early detection of malignant thyroid nodules leading to patient-specific treatments can reduce morbidity and mortality rates. Currently, thyroid specialists use medical images to diagnose then follow the treatment protocols, which have limitations due to unreliable human false-positive diagnostic rates. With the emergence of deep learning, advances in computer-aided diagnosis techniques have yielded promising earlier detection and prediction accuracy; however, clinicians’ adoption is far lacking. The present study adopts Xception neural network as the base structure and designs a practical framework, which comprises three adaptable multi-channel architectures that were positively evaluated using real-world data sets. The proposed architectures outperform existing statistical and machine learning techniques and reached a diagnostic accuracy rate of 0.989 with ultrasound images and 0.975 with computed tomography scans through the single input dual-channel architecture. Moreover, the patient-specific design was implemented for thyroid cancer detection and has obtained an accuracy of 0.95 for double inputs dual-channel architecture and 0.94 for four-channel architecture. Our evaluation suggests that ultrasound images and computed tomography (CT) scans yield comparable diagnostic results through computer-aided diagnosis applications. With ultrasound images obtained slightly higher results, CT, on the other hand, can achieve the patient-specific diagnostic design. Besides, with the proposed framework, clinicians can select the best fitting architecture when making decisions regarding a thyroid cancer diagnosis. The proposed framework also incorporates interpretable results as evidence, which potentially improves clinicians’ trust and hence their adoption of the computer-aided diagnosis techniques proposed with increased efficiency and accuracy.
Machine learning classification of trajectories from molecular dynamics simulations of chromosome segregation
Authors: Geisel David , Lenz Peter
Published: January 2022

In contrast to the well characterized mitotic machinery in eukaryotes it seems as if there is no universal mechanism organizing chromosome segregation in all bacteria. Apparently, some bacteria even use combinations of different segregation mechanisms such as protein machines or rely on physical forces. The identification of the relevant mechanisms is a difficult task. Here, we introduce a new machine learning approach to this problem. It is based on the analysis of trajectories of individual loci in the course of chromosomal segregation obtained by fluorescence microscopy. While machine learning approaches have already been applied successfully to trajectory classification in other areas, so far it has not been possible to use them to discriminate segregation mechanisms in bacteria. A main obstacle for this is the large number of trajectories required to train machine learning algorithms that we overcome here by using trajectories obtained from molecular dynamics simulations. We used these trajectories to train four different machine learning algorithms, two linear models and two tree-based classifiers, to discriminate segregation mechanisms and possible combinations of them. The classification was performed once using the complete trajectories as high-dimensional input vectors as well as on a set of features which were used to transform the trajectories into low-dimensional input vectors for the classifiers. Finally, we tested our classifiers on shorter trajectories with duration times comparable (or even shorter) than typical experimental trajectories and on trajectories measured with varying temporal resolutions. Our results demonstrate that machine learning algorithms are indeed capable of discriminating different segregation mechanisms in bacteria and to even resolve combinations of the mechanisms on rather short time scales.
Effect of intensive care provided by nurse practitioners for postoperative patients: A retrospective observational before-and-after study
Authors: Mori Kazunao , Tsukamoto Yoko , Makino Satoshi , Takabayashi Takuya , Kurosawa Masahiro , Ohashi Wataru , Okumura Masatoshi , Fujita Yoshihito , Fujiwara Yoshihiro
Published: January 2022

Nurse practitioners are increasingly now members of intensive care teams in Japan, but no data exist about their effect on the outcomes for critically ill patients. This study aimed to compare the outcomes of postoperative patients on mechanical ventilators before and after the participation of nurse practitioners in intensive care teams. We retrospectively identified 387 patients who underwent postoperative mechanical ventilation at a University Hospital in Japan, using data from medical records from 1 April 2015 to 31 March 2017. We extracted data and compared patients’ length of stay in the intensive care unit and the hospital, mechanical ventilation days, postoperative rehabilitation start date, rehabilitation prescription, intensive care unit and hospital mortality, and intensive care unit readmission. Multiple regression analysis was used to analyze the factors affecting length of stay in the intensive care unit. Patients who received care from nurse practitioners and physicians had significantly shorter stays in intensive care (4.8 ± 4.8 days versus 6.7 ± 10.3 days, p < 0.021). Mechanical ventilation days, total length of hospital stay, rehabilitation prescription, mortality in intensive care and hospital, and readmission to intensive care were all similar to those who received care only from physicians. The multiple regression analysis suggests that participation of nurse practitioners in intensive care reduced the length of stay in the unit by 2.6 days (p = 0.003). These findings could help to increase use of non-physician healthcare providers in intensive care. Our results demonstrated that it is both effective and safe for nurse practitioners to participate in intensive care teams that provide care for postoperative patients receiving mechanical ventilation.
Agreement between upper and lower limb measures to identify older adults with low skeletal muscle strength, muscle mass and muscle quality
Authors: Phillipe de Lucena Alves Charles , Câmara Marcyo , Dantas Macêdo Geovani Araújo , Freire Yuri Alberto , de Melo Silva Raíssa , Paulo-Pereira Ronildo , Farias-Junior Luiz Fernando , Fayh Ana Paula Trussardi , Mortatti Arnaldo Luis , Costa Eduardo Caldas
Published: January 2022

Background

Identifying low skeletal muscle strength (SMS), skeletal muscle mass (SMM) and skeletal muscle quality (SMQ) is pivotal for diagnosing sarcopenia cases. Age-related declines in SMS, SMM, and SMQ are dissimilar between the upper (UL) and lower limbs (LL). Despite this, both UL and LL measures have been used to assess SMS, SMM and SMQ in older adults. However, it is not clear whether there is agreement between UL and LL measures to identify older adults with low SMS, SMM and SMQ.

Objective

To investigate the agreement between UL and LL measures to identify older adults with low SMS, SMM and SMQ.

Methods

Participants (n = 385; 66.1 ± 5.1 years; 75,4% females) performed the handgrip strength test (HGS) and the 30-s chair stand test (CST) to assess UL- and LL-SMS, respectively. The SMM was assessed by dual-energy X-ray absorptiometry (DXA). The UL-SMQ was determined as: handgrip strength (kgf) ÷ arm SMM (kg). LL-SMQ was determined as: 30-s CST performance (repetitions) ÷ leg SMM (kg). Results below the 25th percentile stratified by sex and age group (60–69 and 70–80 years) were used to determine low SMS, SMM and SMQ. Cohen’s kappa coefficient (κ) was used for the agreement analyses.

Results

There was a slight and non-significant agreement between UL and LL measures to identify older adults with low SMS (κ = 0.046; 95% CI 0.093–0.185; p = 0.352). There was a moderate agreement to identify low SMM (κ = 0.473; 95% CI 0.371–0.574; p = 0.001) and a fair agreement to identify low SMQ (κ = 0.206; 95% CI 0.082 to 0.330; p = 0.005).

Conclusion

The agreement between UL and LL measures to identify older adults with low SMS, SMM and SMQ is limited, which might generate different clinical interpretations for diagnosing sarcopenia cases.
Escavações não suportadas em maciços argilosos. Consolidação e estabilidade global pelo método dos elementos finitos
Authors: Borges José
Published: January 2022

Usando um modelo numérico baseado no método de elementos finitos, analisa-se o comporta mento duma escavação não suportada, em talude, num maciço argiloso sobreconsolidado. O modelo utiliza a teoria multidimensional de consolidação de Biot (formulação acoplada das equações de equilíbrio e escoamen to) com relações constitutivas modeladas pelo modelo de estados críticos p-q-θ . São postos em evidência, por um lado, os aspectos fundamentais do comportamento da obra, designadamente a evolução no tempo, durante e após o período construtivo, dos excessos de pressão neutra, das tensões efectivas, dos deslocamentos e dos níveis de tensão no maciço. Por outro lado, tendo em conta a influência da consolidação na resistência ao corte do maciço, avalia-se a variação no tempo da segurança, usando um programa de cálculo automático de análise da estabilidade global. O programa, formulado segundo pressupostos de equilíbrio limite, utiliza os resultados numéricos das aplicações pelo método de elementos finitos. Por fim, comparam-se os resultados obtidos no problema em estudo (problema-base) com os de outros dois problemas similares nos quais se alteram alguns dos parâmetros, designadamente a geometria da obra e o grau de sobreconsolidação do solo.
Comportamento de estacas sob acções horizontais estáticas e dinâmicas
Authors: Santos Jaime
Published: January 2022

Neste trabalho investiga-se o comportamento de estacas sob acções horizontais estáticas e  dinâmicas. A análise baseia-se fundamentalmente na aplicação de modelos do meio discreto. Para o caso  das acções estáticas, é proposta uma nova metodologia para a construção das curvas p-y. Para as acções  sísmicas, investiga-se o efeito de interacção cinemática solo-estaca recorrendo ao modelo BDWF (Beam  on Dynamic Winkler Foundation). Os modelos do meio discreto são aferidos através de comparações  com formulações tridimensionais do meio contínuo, bem como com os resultados de um ensaio estático  de carga horizontal na cabeça de duas estacas.
Parâmetros de deformabilidade definidos de ensaios in situ “simples e robustos” e sua relação com valores “nobres” de referência em solos saprolíticos de granito
Authors: Viana da Fonseca António , Sousa José , Ferreira Cristiana
Published: January 2022

A estrutura cimentada e a “fábrica” dos solos residuais de granito tem uma forte influência no seu comportamento geomecânico. Alguns perfis típicos da área metropolitana do Porto foram intensamente estuda dos, incluindo campanhas exaustivas de ensaios in situ, tais como SPT, CPT, DP, PMT, SBPT, CH (ensaios sís micos) e PLT (com diferentes áreas de carga). A identificação das propriedades de deformabilidade para o dimen sionamento de obras geotécnicas a partir desses ensaios de campo é fortemente dependente de vários factores, dos quais o nível de deformação será abordado neste artigo. As particularidades estruturais destes solos residuais têm influência na sua tipologia comportamental comandada por uma lei constitutiva de singular não-linearidade. Os módulos de deformabilidade derivados de ensaios simples e robustos (tais como o SPT, CPT, DP ou inclusive o PMT) serão comparados com valores de referência determinados directamente em ensaios sísmicos (como o CH) ou em ensaios de carga (como o PLT) que, por serem directamente avaliados, os apelidaremos de “nobres”. Serão ainda situados nos níveis correspondentes de tensão-deformação e aferidos a partir de ensaios triaxiais em laboratório sobre amostras indeformadas de grande qualidade.
Renivelamento do Edifício Núncio Malzoni com 2.2º de desaprumo
Authors: Maffei Carlos , Gonçalves Heloisa , Pimenta Paulo
Published: January 2022

O Bloco A do Condomínio Núncio Malzoni, localizado na cidade de Santos, apresentava uma inclinação de 2,2º devida a recalques diferenciais. Após uma cuidadosa análise da estrutura do prédio, foi elaborado e executado um projeto para reaprumá-lo. Foram executadas novas fundações e uma estrutura de transição, após o que o prédio foi forçado a retornar à sua posição original por meio da utilização de macacos hidráulicos. O trabalho apresenta a análise do comportamento do solo e da estrutura durante todo o processo, que foi cuidadosamente monitorado.
Estudo numérico de problemas de estabilidade axissimétricos em geotecnia via análise limite
Authors: Ribeiro Wagner , Araújo Luiz , Nogueira Christianne
Published: January 2022

Este artigo apresenta uma formulação numérica mista de análise limite, baseada no método dos elementos finitos (MEF), para problemas de estabilidade axissimétricos em geotecnia. O problema de progra mação matemática resultante é tratado por métodos não lineares. O solo pode ser modelado como meio con tínuo ou reforçado. Para discretização do contínuo são empregados elementos quadrilaterais de 4 nós. As in terfaces (solo-estrutura e solo-reforço) podem ser modeladas através de elementos de interface sem espessura de 4 nós. O reforço pode ser discretizado através de elementos especiais, sem espessura, de 2 nós. O solo e as interfaces são idealizados como materiais rígido-plásticos perfeitos, na hipótese de validade da teoria plastici dade associada. Para o solo é empregado o critério de escoamento de Mohr-Coulomb e a condição de escoa mento das interfaces é descrita pelo critério de Coulomb. Os exemplos estudados pela implementação numé rica realizada (fundação superficial em solo homogêneo ou reforçado, escavação circular e estaca sujeita à tra ção) mostram um desempenho adequado da metodologia apresentada no trabalho para a solução de problemas axissimétricos de Engenharia Geotécnica.
Comportamento de estacas pré-moldadas e escavadas, instrumentadas, em solo não saturado. A experiência do campo experimental da Unicamp –Campinas
Authors: Albuquerque Paulo , Carvalho David , Ferreira Cláudio , Lobo Ademar
Published: January 2022

O objetivo deste trabalho é analisar, através de resultados obtidos em provas de carga do tipo lenta, o comportamento de uma estaca pré-moldada e de três escavadas a trado mecânico, instrumentadas ao longo do fuste, implantadas em um solo de diabásio, não saturado, característico da região de Campinas (Estado de São Paulo) e outras regiões sul-sudeste do Brasil. Foram realizadas provas de carga estática e dinâmica em uma estaca pré-moldada (L=14,0m e φ=0,18m) e provas de carga estática em três estacas escavadas (L=12,0m e φ=0,40m), todas instrumentadas com extensômetros elétricos (strain-gages) ao longo do fuste, com a finalidade de se obter as parcelas de carga resistida ao longo do fuste e pela ponta. Os ensaios foram realizados no Campo Experimental de Mecânica dos Solos e Fundações da Unicamp, cujo subsolo é constituído por uma primeira camada (0 a 6m) de argila silto-arenosa, colapsível, sobrejacente a uma outra camada (6 a 18m) de silte argilo arenoso (residual). O nível d’água não é encontrado até 17m. O subsolo do local já foi estudado em diversas pesquisas anteriores, através da realização de ensaios de campo e ensaios laboratoriais, sendo que os dados dis poníveis possibilitam o enriquecimento das análises efetuadas. É feita uma comparação entre o comportamento dos dois tipos de estacas. São analisadas também a aplicabilidade de fórmulas de previsão da carga de ruptura para esses tipos de estacas. É apresentada uma metodologia de determinação da resistência lateral de estacas a partir de dados obtidos em Sondagem de Simples Reconhecimento (SPT) com leitura do torque.
Resistência dos solos: dilatância versus coesão efectiva
Authors: Neves Emanuel
Published: January 2022

Através da análise de aspectos fundamentais da Mecânica dos Solos dos Estados Críticos, mostra-se que o uso do conceito de coesão efectiva é uma fonte de confusões, pois não só dá indicações erradas quanto ao modo como os solos resistem às tensões deviatóricas, como origina nomenclaturas para os solos que não ajudam a clarificar esta questão. Em particular, mostra-se que na abordagem da resistência mecânica o papel atribuído à coesão efectiva deve ser substituído pelo desempenhado pela dilatância.
O método das ondas superficiais: aquisição, processamento e inversão
Authors: Lopes Isabel , Santos Jaime , Almeida Isabel
Published: January 2022

Este trabalho apresenta os fundamentos teóricos associados ao método das ondas superficiais utilizando múltiplas estações segundo a metodologia implementada, referindo-se aos principais passos da sua aplicação: a aquisição, o processamento e a inversão. Fundamentando com as bases da teoria de propagação das ondas de Rayleigh, discutem-se os factores determinantes e os cuidados a ter para a obtenção de resultados fiáveis e de boa qualidade.
Ensaios de arrancamento de pequeno porte para estudo de reforço de pavimentos
Authors: Ferreira Julio , Bueno Benedito , Zornberg Jorge
Published: January 2022

Este trabalho apresenta um estudo comparativo da eficiência de diferentes geossintéticos no reforço de base de pavimentos de obras viárias com ensaios de arrancamento de pequeno porte. Utilizou-se geogrelhas de polipropileno e de fibra de vidro e geotêxtil tecido de polipropileno. Foram empregados um solo com 58% de argila (subleito) e um pedregulho areno-siltoso (camada de base). Os ensaios de arrancamento foram executados com diferentes combinações entre solos e geossintéticos. Neles foi utilizado um sistema de medida direta de des - lo camentos ao longo da inclusão com sensores óticos a laser. Curvas módulo de rigidez confinada dos geos sin - té ticos foram obtidas a partir dos resultados dos ensaios de arrancamento. Realizou-se também análise com o coe - fi ciente de aderência proposto por Jewell. Segundo o presente estudo, a melhor opção para os solos e geos sin - té ticos utilizados segue a seguinte ordem: (1) geogrelha de polipropileno, (2) geotêxtil tecido de polipropileno e (3) geogrelha de fibra de vidro.
Caracterização do comportamento geotécnico de amostras de EPS por meio de ensaios de laboratório
Authors: Neto José , Bueno Benedito
Published: January 2022

O poliestireno expandido (EPS) foi recentemente introduzido no Brasil como material de baixa massa específica para construções de aterros sobre solos moles e encontros de pontes. Devido este fato, não há nenhuma experiência consolidada em ensaios deste produto de um ponto de vista geotécnico no Brasil. Este artigo apresenta resultados de uma pesquisa de laboratório com ensaios mecânicos e hidráulicos, com o objetivo de caracterizar amostras de EPS para o uso geotécnico. Os testes mecânicos compreenderam não somente a compressão uniaxial, mas também ensaios de compressão cíclica, importante em projetos de pavimentos, e o cisalhamento direto da interface. Os ensaios hidráulicos incluíram absorção de água e permeabilidade. Os resultados mostram que o EPS possui uma grande resistência, apesar da baixa massa específica, e boas propriedades geotécnicas para uso na área de engenharia geotécnica.
Factores condicionantes na selecção do processo construtivo das estacas de betão
Authors: Penteado Maria , Brito Jorge
Published: January 2022

A escolha do tipo de estaca (betonada in situ ou pré-fabricada) e, dentro desta, a resolução da problemática construtiva não são problemas lineares. Admitem à partida uma grande diversidade de opções e só o conhecimento em absoluto do comportamento de cada uma delas possibilitaria a escolha da solução mais conveniente. Contudo, podem citar-se os seguintes factores - características geotécnicas e hidrogeológicas, local de execução (ruído e vibrações), plano de cargas, sismicidade, custos e outros factores (qualidade e prazo de execução pretendidos, por exemplo) - como sendo condicionantes aquando da escolha do processo cons - trutivo das estacas de betão. No presente artigo pretende-se, através de uma abordagem orientada para as correctas práticas construtivas, estabelecer algumas conclusões acerca daqueles factores.
Zonas de risco a escorregamentos no município de Guarulhos/SP, Brasil
Authors: Gomes Gabriela , Oliveira Antonio , Sato Sandra
Published: January 2022

Este trabalho apresenta resultados obtidos da análise geoambiental realizada no município de Guarulhos (SP, Brasil) em microbacia onde o uso do solo é irregular, ilegal e ambientalmente inadequado, com áreas de risco sujeitas a escorregamentos. O objetivo principal foi o de reconhecer áreas de risco a escorregamentos, elaborando um modelo fenomenológico que destaca a declividade > 60% (inclinações > 30º) e as formas inadequadas de uso (cortes e aterros) como principais condicionantes. O mapa de declividade fun damentou a elaboração do mapa de suscetibilidade que, cruzado ao de uso do solo, indicou as áreas com risco. O produto final, o mapa síntese de zoneamento de risco e de suscetibilidade a escorregamentos, contribui para ações de planejamento urbano e intervenção ambiental previstas pela Prefeitura desse município.
Variante a Santarém – Tratamento da fundação do novo aterro ferroviário sobre as aluviões do Tejo
Authors: Melo Pedro , Mira Emanuela , Rebouço Marie , Midões Tiago
Published: January 2022

É apresentada, neste trabalho, a caracterização geotécnica dos depósitos aluvionares do Tejo ocorrentes na fundação do aterro do novo troço de via férrea inserido no Projecto da Variante a Santarém da Linha do Norte e a definição duma solução para a melhoria e reforço dessa fundação. A solução de Projecto, concebida com base nos resultados da caracterização geotécnica efectuada, consistiu na aceleração do processo de consolidação dos materiais aluvionares da fundação através da instalação duma rede de geodrenos verticais, associada a um aterro de pré-carga, e no reforço da base dos aterros com a colocação de geotêxteis tecidos de elevada resistência.
Avaliação da interação solo-estrutura através da monitoração de recalques
Authors: Maia Paulo , Barros Rodrigo , Juniro Fernando
Published: January 2022

Este trabalho apresenta os resultados experimentais da monitoração dos recalques de um edifício residencial durante a construção. A fundação do edifício é constituída por estacas hélice contínuas. O maciço de fundação é constituído basicamente por solos fofos ou moles. O objetivo do trabalho é a avaliação da interação solo estrutura e a sua influência no comportamento da construção. É apresentada uma breve descri ção da metodologia empregada no trabalho. A avaliação do carregamento na fundação é realizada através de análise numérica tridimensional de um modelo da estrutura. São considerados dois modelos mecânicos: fun dações fixas, sem movimento, e fundações com deslocamento vertical livre. O mecanismo de interação solo estrutura foi determinado através da comparação dos deslocamentos utilizando os carregamentos obtidos atra vés dos dois modelos mecânicos. Os resultados permitem avaliar a redristribuição de carga devido à interação solo estrutura durante o aumento da rigidez da estrutura.
Melhoramento de solos arenosos fofos por estacas de compactação
Authors: Moraes Maria , Bicalho Kátia , Castello Reno
Published: January 2022

Analisam-se os resultados da utilização de uma técnica de melhoramento de solo arenoso para viabilização de projetos de fundações de edifícios residenciais com vários andares, apoiadas sobre sapatas. A técnica de melhoramento foi compactação profunda por estacas de densificação cravadas pelo processo tipo Franki e compactação superficial por placa vibratória. Recuperam-se e analisam-se dados das condições do solo antes da melhoria, logo após a melhoria e após decorrer algumas semanas. Analisam-se os dados quanto a sua posição relativa às estacas, quanto à compacidade inicial do solo, quanto ao tempo e quanto à profundi dade. As análises dos resultados obtidos comprovam a eficiência da técnica utilizada.
Instabilidade de vertente em maciço granítico fracturado e alterado (Terras de Bouro, NW De Portugal)
Authors: Ferreira Luís , Lima Alberto , Pamplona Jorge , Braga Maria
Published: January 2022

O presente trabalho incide sobre a instabilidade de uma vertente que surgiu na região granítica da Serra do Gerês, na freguesia de Rio Caldo, concelho de Terras de Bouro (NW de Portugal), no Inverno de 2000 – 2001. O local é uma zona de falha preenchida por argila siltosa, pouco plástica, na qual a caulinite domina sobre a gibsite. Os solos residuais graníticos circundantes apresentam percentagens significativas de finos e teores elevados de minerais argilosos, nos quais a gibsite domina sobre a caulinite. A hipótese que se afigura como mais provável para explicar a instabilidade consiste num deslizamento composto sobre o plano de falha com uma outra componente curvilínea. Para o seu desencadeamento terá sido decisivo o grande volume de água infiltrada (2264 mm) e a diferença de características mecânicas entre a caixa de falha e os solos envolventes. Durante o período de estudo o local não apresentou sinais de movimentação. As medidas de remediação visam, essencialmente, a drenagem e a impermeabilização dos solos.
Atenuação de metais pesados provenientes da percolação de lixiviado em colunas preenchidas com solo
Authors: Kasemodel Mariana , Almeida Tânia , Schalch Valdir
Published: January 2022

O presente trabalho visou o estudo da atenuação de metais potencialmente tóxicos, presentes em lixiviado de chorume, em colunas preenchidas com solo. O solo e o lixiviado foram coletados no aterro sani tário de São Carlos-SP. Ambos foram caracterizados previamente. Os ensaios foram montados em colunas de acrílico, as colunas foram preenchidas com solo e o lixiviado de chorume foi percolado ascendentemente. O experimento foi realizado em quatro colunas, sendo que duas foram percoladas com o lixiviado de chorume sem alterações e nas outras duas o lixiviado foi acidificado e enriquecido com metais. A cada 0,2 VP (volume de poro) preenchido, retirou-se alíquotas que foram caracterizadas. O afluente também foi caracterizado a cada 15 dias de experimento. Observou-se que o solo foi capaz de reter metais potencialmente tóxicos, mesmo sendo caracterizado como arenoso. No entanto, a capacidade de atenuação do solo é limitada, observando-se um decréscimo na retenção de metais ao longo do experimento.
Two subject specific modelling approaches to construct base-age invariant polymorphic site index curves with varying asymptotes
Authors: Sprengel Lars , Spiecker Heinrich , Wu Shuirong
Published: January 2022

For constructing growth and yield models the concept of site index as measure of productivity is crucial. Here, we use nonlinear mixed-effects models (NLME) with random individual effects and nonlinear models with dummy variables as fixed individual effects (NLFE) to fit mechanistic growth functions to stem analysis data of the economically most important tree species in Zhongtiaoshan forest region, China. The Richards and Lundqvist function are formulated into five dynamic equations (R1, R2, L1, L2 and L3) applying the generalized algebraic difference approach (GADA), which inherit polymorphism, varying asymptotes and base-age invariance. According to Akaike information criterion the R1 model as NLFE fits height growth data of CarriÃ¨re, Franch., Koidz., Blume and Sukaczev best, while for Blume R2 as NLFE fits height growth data best. For Mayr L1 as NLME has been selected as best model, as R1 and R2 both as NLFE and NLME are not extrapolating the comparably short length of height growth data well enough. However, according to the root mean square error and bias differences between model fits of both the selected equation and the chosen model fitting approach are not so clear. Presented families of height growth curves serve as planning tools to identify site index and therefore assess productivity of forest stands in the studied region. A direct comparison of the productivity of forest stands of the same tree species is possible due to base-age invariance of the selected models.Pinus tabuliformisPinus armandiiQuercus liaotungensisQuercus alienaBetula platyphyllaQuercus variabilisLarix principis-rupprechtii
A Study of Intrahepatic Cholestasis of Pregnancy and Its Perinatal Outcome in a Tertiary Care Centre
Authors: Regunathan Aishwarya , Srinivasan Bhuvana
Published: January 2022

BACKGROUND Intrahepatic cholestasis is one of the unique conditions specific to pregnancy and should be kept in mind when a patient presents with excessive pruritus seen during the late second and early third trimester of pregnancy, causing subtle alterations in liver functions with increased serum bile acids. This study intended to determine the prevalence of obstetric cholestasis in our hospital, its course and pregnancy outcome in these women. METHODS This is a prospective cross sectional study, carried out among the women attending the Department of OBG, Sri Ramachandra medical college. A total of 22 cases were observed to have obstetric cholestasis from those who attended the hospital during the study period. The data about the variables like patient identification details, demographic data, symptoms, laboratory parameters, feto-maternal outcomes were recorded like pre-existing medical conditions, mode of delivery, birth weight, Apgar score at 1 min and 5 mins and admission to NICU were recorded. Data collected were analysed and the data variables were represented appropriately. RESULTS A total of 1813 deliveries were conducted in the study setting during the study period. 1.2 % of cases were observed to have intrahepatic cholestasis. The mean gestational age of onset of obstetric cholestasis was 28 weeks. The mean age of the women considered for the study was 28.5 ± 2.8 years (22-34 years). The mean serum bile acid observed at the time of admission was 33.6 ± 25.2. The mean gestational age at the delivery of the study subjects was 36 W ± 5 days. 50 % of the women had laboured at term and 50 % of the women had preterm labour. 9 women (41 %) delivered through NVD and 13 women (59 %) delivered through lower segment caesarean section. One patient had recurrent cholestasis. The average Apgar score at 1 minute was 7 and at the end of 5 minutes it was 8. 50 % of the children admitted to NICU and 4 women gave the history of admissions into NICU of the babies born even in the previous deliveries, due to varied reasons. No perinatal or maternal mortality was observed during the study period. CONCLUSIONS Intrahepatic cholestasis of pregnancy is common among pregnant women which has an impact on feto-maternal outcomes. It is found to be responsible for a large number of perinatal and neonatal deaths especially after 36 weeks of gestation, but if appropriate antenatal care and timely intervention are implemented outcomes of pregnancy would be better. KEY WORDS Intra hepatic Cholestasis, Pregnancy, Ursodeoxycholic Acid, Pruritus.
Safety and Efficacy of Nonoperative Treatment in Esophageal Perforation Caused by Foreign Bodies
Authors: Liao Foqiang , Zhu Zhenhua , Pan Xiaolin , Li Bimin , Zhu Yin , Chen Youxiang , Shu Xu
Published: January 2022

INTRODUCTION:

Esophageal foreign bodies are often treated by endoscopy, but the treatment of esophageal perforation caused by foreign bodies remains controversial. The purpose of this study was to investigate the safety and efficacy of nonoperative treatment of esophageal perforation caused by foreign bodies.

METHODS:

We retrospectively analyzed 270 patients admitted to our hospital for esophageal perforation caused by foreign bodies from January 2012 to December 2020, all of whom received nonoperative treatment.

RESULTS:

The mean age of the patients was 56 ± 17 years, and fish bones were the most common type of foreign body. A total of 61.2% of the perforations were in the cervical esophagus. All patients received nonoperative treatment initially, and the foreign body removal rate using endoscopy reached 97%. The perforation healing rate reached 94.8%, whereas 3 patients (1.1%) died during hospitalization. The median (range) duration of hospitalization was 4 days (3–6). Multivariable analysis showed age ≥ 66 years (odds ratio [OR]: 2.196; 95% confidence interval [CI]: 1.232–3.916; P = 0.008), men (OR: 1.934; 95% CI: 1.152–3.246; P = 0.013), and time to treatment (OR: 1.126; 95% CI: 1.027–1.233; P = 0.011) were independent risk factors for infection, whereas the risk of infection was lower when the foreign body type was fish bone (OR: 0.557; 95% CI: 0.330–0.940; P = 0.028).

DISCUSSION:

Nonoperative treatment is safe and effective for esophageal perforation caused by foreign bodies. Even if perforation is combined with infection, active nonoperative treatment can still achieve a good effect. Early intervention can effectively reduce the risk of infection and improve patient outcomes.
Komparasi Tingkat Aksesibilitas Jaringan Transportasi Publik bagi Pekerja Ulang-Alik di Kawasan Surabaya Metropolitan Area
Authors: Shabrina Salsa , Nurlaela Siti
Published: January 2022

The movement of commuter workers in Surabaya Metropolitan Area is dominated by private transportation modes users. Most commuter workers do not use public transportation for several accessibility reasons, such as long travel time (33.9%) and less practicality (32.7%). Previous research has been undertaken to encourage modal shifting from the perspective of workers as travelers. This type of researches emphasis more on exploring what factors can be intervened in order to make a modal shift from private vehicles to public transportation. What is not yet known is what causes the lack of competitiveness of public transportation. Namely, there are no studies that measure the level of accessibility of the public transportation network and the factors that influence it. This study aims to determine the factors that affect accessibility of public transportation networks for commuter workers in Surabaya Metropolitan Area based on a comparison of the level of accessibility in Sidoarjo-Surabaya and Gresik-Surabaya areas. The results of the study show that the level of accessibility in Surabaya Metropolitan Area is influenced by travel impedances, public transport routes, travel times, and the frequency of public transportation. Accessibility in Sidoarjo-Surabaya area can be improved by adding 1 public transport route in Gedangan District and increasing the frequency of public transportation to 4 units per hour in Waru and Sedati Districts. Whereas in Gresik-Surabaya area, accessibility can be improved through the addition of 1 public transport route in Menganti District and increasing the frequency of public transportation to 4 units per hour in Cerme District.