bluuebunny/crossref_metadata_2025 huggingface dataset:
Are current DRG-based bundled payment models for revision total joint arthroplasty risk-adjusting adequately?
Authors: Malik Azeem T. , Li Mengnai , Khan Safdar N. , Alexander John H. , Li Daniel , Scharschmidt Thomas J.
Published: June 2020

Aims

Currently, the US Center for Medicaid and Medicare Services (CMS) has been testing bundled payments for revision total joint arthroplasty (TJA) through the Bundled Payment for Care Improvement (BPCI) programme. Under the BPCI, bundled payments for revision TJAs are defined on the basis of diagnosis-related groups (DRGs). However, these DRG-based bundled payment models may not be adequate to account appropriately for the varying case-complexity seen in revision TJAs.

Methods

The 2008-2014 Medicare 5% Standard Analytical Files (SAF5) were used to identify patients undergoing revision TJA under DRG codes 466, 467, or 468. Generalized linear regression models were built to assess the independent marginal cost-impact of patient, procedural, and geographic characteristics on 90-day costs.

Results

A total of 9,263 patients (DRG-466 = 838, DRG-467 = 4,573, and DRG-468 = 3,842) undergoing revision TJA from 2008 to 2014 were included in the study. Undergoing revision for a dislocation (+$1,221), periprosthetic fracture (+$4,454), and prosthetic joint infection (+$5,268) were associated with higher 90-day costs. Among comorbidities, malnutrition (+$10,927), chronic liver disease (+$3,894), congestive heart failure (+$3,292), anaemia (+$3,149), and coagulopathy (+$2,997) had the highest marginal cost-increase. The five US states with the highest 90-day costs were Alaska (+$14,751), Maryland (+$13,343), New York (+$7,428), Nevada (+$6,775), and California (+$6,731).

Conclusion

Under the proposed DRG-based bundled payment methodology, surgeons would be reimbursed the same amount of money for revision TJAs, regardless of the indication (periprosthetic fracture, prosthetic joint infection, mechanical loosening) and/or patient complexity. Cite this article: Bone Joint J 2020;102-B(7):959–964.
The new MFDS examination: making an inspired choice
Authors: Littlewood Simon , Marsden Patricia , Harvey Caroline , Landau Alex , Voerman Kim
Published: June 2020

The Diploma of Membership of the Faculty of Dental Surgery (MFDS) is the newly re-established dental qualification of the RCS, which plays an important part in marking progression in dental careers. This article describes how the MFDS has been redesigned to provide a modern, innovative and relevant assessment for today’s dentists keen on professional development, and highlights some of the potential benefits of gaining this gold standard postgraduate qualification.
The effect of anaesthetic gases on global warming
Authors: Saliakelli Dimitra , Harley Kathryn
Published: June 2020

Essential for medicine, damaging for the Earth: how can we reduce anaesthetic waste and pollution?
Family matters: personal assistants’ experiences of engaging and working with their employers’ families
Authors: Manthorpe Jill , Woolham John , Norrie Caroline , Samsi Kritika
Published: June 2020

Many people in England employ care workers using state funding or their own resources. This article explores working relationships, communications and experiences of personal assistants with their employers’ family members. Data from interviews with 105 personal assistants (in 2016–17) were analysed to explore relationships and experiences. Three overarching themes related to personal assistants’ engagement with family members arose: (1) possible complications over accountability and employment; (2) support for family; and (3) being part of care teams. This article provides new insights into personal assistants’ relationships with employers’ family members, highlights the relevance of the concept of immaterial labour and sets out a research agenda.
Analítica de los usos digitales y rendimiento académico. Un
estudio de caso con estudiantes universitarios
Authors: De la Iglesia Villasol M. Covadonga
Published: June 2020

INTRODUCCIÓN: El estudio que se presenta analiza los usos y
registros digitales de los estudiantes en un curso presencial, que a
modo de huella dejan en los espacios virtuales complementarios, así
como las calificaciones que obtienen en las fases de evaluación
continua y final. El objetivo es encontrar si existe relación
positiva entre el mayor uso y participación de los estudiantes en
las plataformas digitales y las calificaciones obtenidas. MÉTODO: Se
adopta un diseño cuantitativo de tipo descriptivo y no experimental.
La población analizada se corresponde con el curso de Análisis
Microeconómico Avanzado, del grado en Economía (GECO), en la
Universidad Complutense de Madrid. RESULTADOS: Los resultados
muestran un uso digital tradicional y polarizado de los estudiantes,
que definen tipologías y patrones diferenciados de aprendizaje, muy
condicionado a la programación de la evaluación continua, y
correlacionado positivamente con las calificaciones obtenidas.
DISCUSIÓN: La relación entre usos digitales y resultados del
aprendizaje es un tema aún poco explorado en la literatura, que
contribuye a la reflexión del docente y puede reorientar el proceso
de enseñanza, para evitar que los estudiantes que se van quedando
rezagados en el uso digital acompasen el ritmo al avance del curso y
tengan mejores resultados académicos.
Process regimes during welding of glass by femtosecond laser pulse bursts
Authors: Hecker Sebastian , Blothe Markus , Grossmann Daniel , Graf Thomas
Published: June 2020

Various process regimes were observed during microwelding of glass with bursts of ultrashort laser pulses. Two major welding regimes and various subregimes were identified for two different materials. The radiation emitted by the laser-induced plasma was used to monitor different regimes that characterize glass microwelding. A comprehensive understanding of the various process regimes can be exploited to use the regimes according to their specific advantages, especially for industrial applications.
Reflectionless zero refractive index metasurface in the terahertz waveband
Authors: Suzuki Takehito , Asada Harumi
Published: June 2020

Zero refractive index materials behave electromagnetically as single points despite the finite dimensions because a propagating electromagnetic wave passes with an infinite phase velocity. However, the composition of naturally occurring materials cannot produce a zero refractive index material because any effect of both of the dielectric and magnetic properties would have to vanish (be near zero). In this report, we demonstrate a zero refractive index metasurface with a refractive index of 0.16 + j0.09, the reflectance of 0.7%, and transmittance of 97.3% at 0.505 THz. The measured relative permittivity and relative permeability are 0.18 − j0.10 and 0.004 + j0.16 at 0.505 THz, respectively. Both the relative permittivity and relative permeability simultaneously approach zero at the same frequency, and the dielectric and magnetic properties appear to be absent (vanish) in the artificial material. The zero refractive index metasurface can offer a material platform for terahertz applications with unprecedented functionalities for 6G (beyond 5G) wireless communications, imaging, and security.
Nonsequential double ionization of Ar in near-single-cycle laser pulses
Authors: Chen Zhangjin , Liu Fang , Wen Hua , Morishita Toru , Zatsarinny Oleg , Bartschat Klaus
Published: June 2020

Using the improved quantitative rescattering (QRS) model, we simulate the correlated two-electron momentum distributions (CMD) for nonsequential double ionization (NSDI) of Ar by near-single-cycle laser pulses with a wavelength of 750 nm at an intensity of 2.8 × 1014 W/cm2. With the accurate cross sections obtained from fully quantum mechanical calculations for both electron impact excitation and electron impact ionization of Ar+, we unambiguously identify the contributions from recollision direct ionization (RDI) and recollision excitation with subsequent ionization (RESI). Our analysis reveals that RESI constitutes the main contribution to NSDI of Ar under the conditions considered here. The simulated results are directly compared with experimental measurements [Bergues et al., Nat. Commun. 3, 813 (2012)10.1038/ncomms1807] in which each NSDI event is tagged with the carrier-envelope phase (CEP). It is found that the overall pattern of both the CEP-resolved and the CEP-averaged CMDs measured in experiment are well reproduced by the QRS model, and the cross-shaped structure in the CEP-averaged CMD is attributed to the strong forward scattering of the recolliding electron as well as the depletion effect in tunneling ionization of the electron from an excited state of the parent ion.
Dayak Kaharingan di tengah perubahan sosial ekologi dan praktik perpindahan agama di pedesaan Kalimantan Tengah
Authors: Kumoro Nindyo Budi
Published: June 2020

This paper tries to explain the relation between social-ecological change and the phenomenon of religious conversion in a minority group in Indonesia. The case study is the Dayak community religion in Central Kalimantan, Kaharingan, with 'world' or 'official' religions such as Christianity, Catholicism, or Islam. The study of Kaharingan in this paper is placed in the context of Kalimantan as an object of resource expansion with massive intensity by the global economic capitalist chain. Forest exploitation and local gold mining activity from outsiders urged Dayaks to participate in new economic patterns, which caused swidden cultivation to become inaccessible to villagers and began to slowly be abandoned. This has implications for the transformation of the Dayaks in perceiving their relationship with the natural environment, a relationship that was previously the basis of Kaharingan religious beliefs and practices. Based on my ethnographic research in the rural Dayak community upriver Katingan, this paper shows that the religious conversion from Kaharingan to a new religion is more driven by social and economic morals that emphasize individual-household relations rather than the communal-collective pattern as before. This paper also argues that although traditional beliefs have slowly been abandoned, the practice of Kaharingan ceremonies is still held intensively for different purposes.Keywords: Minority religion, socio-economic and ecological change, religious conversion Abstrak Artikel ini berupaya menunjukkan relasi perubahan sosial-ekologi dengan fenomena perpindahan agama pada kelompok minoritas di Indonesia. Studi kasus dalam tulisan ini adalah agama masyarakat Dayak Kalimantan Tengah, yakni Kaharingan, dengan agama ‘dunia’ atau ‘resmi’ seperti Kristen, Katolik, maupun Islam di sana. Kajian mengenai Kaharingan di sini diletakkan dalam konteks Kalimantan sebagai obyek dari ekspansi sumber daya dengan intensitas yang massif oleh rantai ekonomi kapitalisme global. Eksploitasi kayu maupun pertambangan lokal dari pihak luar mendorong orang Dayak turut berpartisipasi dalam pola ekonomi baru menggeser perladangan berpindah ke posisi yang tidak menguntungkan. Hal ini turut mendorong perubahan orang Dayak dalam memaknai relasi mereka dengan alam sekitar, relasi yang sebelumnya menjadi basis kepercayaan dan praktik agama Kaharingan. Dengan mendasarkan pada hasil riset etnografi pedesaan Dayak di hulu Sungai Katingan, tulisan ini menunjukkan bahwa perpindahan agama dari Kaharingan ke agama baru lebih didorong oleh moral sosial dan ekonomi baru yang menekankan relasi individu-rumah tangga dari pada komunal-kolektif seperti sebelumnya. Tulisan ini juga ingin menunjukkan meskipun kepercayaan lama telah ditinggalkan, namun praktik upacara Kaharingan tetap digelar dengan intensif meskipun untuk tujuan yang berbeda. Kata kunci: Agama minoritas, perubahan material-ekologi, perpindahan agama
Marjinalisasi Perempuan Kuli Panggul di Pasar Pabean Surabaya Marjinalisasi Perempuan Kuli Panggul di Pasar Pabean Surabaya
Authors: Yuniarti Miranti Dwi
Published: June 2020

Marginalization often occurs in Indonesia, and it makes people gradually consider marginalization as a natural phenomenon. Female porters are one of the marginalized groups in Indonesia. They have been marginalized by others, but they donot realize it. This paper analyzes and describes the dilemmas and kind of marginalization faced by female porters in Pabean Surabaya market. The methods used in this study were qualitative, including direct observation and in-depth interviews. The results suggest that female porters marginalized by getting differential treatmentby other people, they can not negotiate their wages with customers which makes the income they earn incommensurate with their hard work, which is also exacerbated by the wage differential between female porters and male porters. They also face some dilemmas related to their work such as: (1)having double burden as housewives and workers, (2)limited skills so they can not choose a better job for them, (3)insufficient income for daily needs, (4)social pressure from fellow workers and other people. Marjinalisasi sering terjadi di Indonesia dan hal ini membuat masyarakat secara tidak sadar menganggap marjinalisasi merupakan hal yang biasa, meski pun itu merupakan hal yang salah. Perempuan kuli panggul merupakan salah satu kelompok yang termarjinal di Indonesia. Mereka dimarjinalisasi oleh masyarakat, namun mereka sendiri tidak menyadarinya. Tulisan ini dibuat untuk menganalisis dan menjelaskan dilema-dilema dan bentuk marjinalisasi yang dialami perempuan kuli panggul di pasar Pabean Surabaya. Metode yang digunakan adalah pendekatan kualitatif yang terdiri dari observasi langsung dan wawancara mendalam. Hasil penelitian menunjukkan bahwa perempuan kuli panggul mengalami marjinalisasi dengan cara diperlakukan berbeda oleh masyarakat. Mereka tidak dapat menawar upah sehingga upah yang didapatkan tidak sesuai dengan kerja keras mereka. Upah mereka pun juga memiliki jumlah yang lebih sedikit daripada kuli panggul laki-laki. Dilema yang mereka hadapi sebagai kuli panggul adalah: (1)adanya beban ganda sebagai kuli panggul dan juga sebagai ibu rumah tangga, (2)kemampuan yang terbatas sehingga mereka tidak dapat memilih pekerjaan yang lebih baik, (3)pendapatan yang seringkali tidak dapat menutupi kebutuhan sehari-hari, (4)serta tekanan sosial dari sesama kuli panggul
Rare Association Between Neuroimmunological Diseases: A Possible Autoimmune Polyglandular Syndrome Type IV
Authors: Araújo Tainá de , Bandeir Isabelle Pastor , Parolin Laura Fiuza , Gonçalves Marcus Vinícius Magno
Published: June 2020

Autoimmune polyglandular syndromes (APS) are a diverse group of clinical conditions characterized by loss of immune tolerance in various tissues. This condition can be diagnosed in childhood or adulthood, with changes in the components of the disease throughout life. Here, an unusual case of association between immune-mediated diseases will be addressed: Myasthenia Gravis, Systemic Lupus Erythematosus, and Celiac Disease. In this patient, each disease was expressed over time. Finally, we assume that this is a clinical form of APS type IV, due to the lack of thyroid involvement to date.
Investigação da Variação Volumétrica de Reservatório de Abastecimento de Água Mediante o Emprego de Diferentes Espaçamentos entre as Linhas Regulares de Sondagem
Authors: Alves Sérgio da Conceição , Krueger Cláudia Pereira
Published: June 2020

O Levantamento Batimétrico (LB) tem como objetivo a determinação e a representação gráfica do relevo topográfico de áreas submersas. O detalhamento dessas superfícies é uma inferência da disposição dos dados batimétricos e da precisão de aquisição destes dentro dos limites especificados para cada equipamento sonar de feixe único. Por conseguinte, a precisão dos Modelo Digitais de Elevação (MDEs) está relacionada a esses preceitos e, consequentemente, infere na precisão volumétrica de reservação. Durante o LB, realizado no pré-reservatório do Passaúna, localizado na região metropolitana de Curitiba-PR, planejou-se o espaçamento entre as Linhas Regulares de Sondagem (LRS) de 15 metros, este, no entanto, foi aumentando de 15 em 15 m até, conforme as orientações vigentes para esses ambientes, alcançar o espaçamento de 300 metros. E para cada conjunto de dados, determinou-se o MDE utilizando os interpoladores Kriging (KRG) e Inverse Distance Weighted (IDW). Em seguida, determinou-se os resíduos a partir da comparação entre as profundidades sondadas, obtidas nas linhas de verificação, com as profundidades interpoladas, advindas dos MDEs, onde obteve-se um Root Mean Square médio de 0,180 m nos MDEs com as LRS espaçadas de 15 até 105 metros gerados com os dados posicionadas com o WS3910 e interpoladas com o IDW. A partir da comparação entre os volumes advindos dos MDEs com o modelo computado com os dados batimétricos com as LRS espaçadas em 15m, obteve-se uma diferença volumétrica abaixo de -4,76% nos MDEs com LRS espaçadas de 30 metros até 180 metros.
A questão do acesso aos serviços de orientação técnica no Brasil e no estado de Goiás
Authors: Diniz Raphael Fernando , Clemente Evandro Cesar
Published: June 2020

Buscou-se analisar, neste artigo, em que medida os investimentos e ações feitos entre 2003 e 2017 pelo governo federal no serviço extensionista lograram êxito na consecução satisfatória de seus objetivos. Para isso, recorremos à análise de um conjunto de dados dos Censos Agropecuários do Instituto Brasileiro de Geografia e Estatística (IBGE) de 2006 e 2017. O recorte espacial de investigação compreendeu o Brasil, o estado de Goiás e suas cinco Mesorregiões Geográficas. A partir da análise dos dados, constatamos que a retomada dos investimentos federais no serviço extensionista não foi suficiente para promover a universalização e a democratização de seu acesso no país, nem tampouco possibilitou a expansão dos sistemas de produção menos nocivos ao ambiente e à saúde humana, inviabilizando, assim, a construção de um modelo de desenvolvimento rural sustentável, solidário e equitativo no campo brasileiro. Para mitigar ou mesmo superar as questões evidenciadas neste trabalho, urge construir e articular estratégias visando garantir o acesso à orientação técnica de qualidade e em quantidade necessária às demandas dos agricultores, buscando promover um novo modelo de desenvolvimento fundamentado em sistemas de produção mais autônomos, resilientes e sustentáveis.
Modo de vida e identidade no quilombo de Cordoaria
Authors: De Souza Sandro Araújo , Macêdo de Alencar Cristina Maria , Suzuki Júlio César
Published: June 2020

Modo de vida e identidade se definem como fundamentos essenciais da construção social quilombola. Assim, este artigo procura analisar as alterações e continuidades no modo de vida na Comunidade Remanescente Quilombola de Cordoaria, situada no município de Camaçari-BA integrante da Região Metropolitana de Salvador (RMS), em relação com a identidade étnica afirmada por seus sujeitos sociais, nas duas primeiras décadas do século XXI. Para tanto, realizou-se pesquisa qualitativa por meio de revisão bibliográfica, com foco nas categorias modo de vida, identidade e quilombo; coleta das narrativas de vida entre os sujeitos investigados; e interpretação das falas tendo como parâmetro a análise de conteúdo, tomando-se como base os referenciais implicados na narrativa (modo de vida rural e identidade quilombola). Constatou-se que os quilombolas de Cordoaria conformam a manutenção das suas atividades cotidianas no meio rural com os laços de pertencimento ao lugar, absorvendo alterações advindas da sua proximidade e imersão na dinâmica urbano-metropolitana da RMS. Assim, a territorialidade emerge associada à defesa e resgate das tradições locais, fortalecendo os vínculos comunitários pela afirmação da identidade étnica do grupo social, com continuidades do modo de vida rural em interação com o urbano-metropolitano.
munidade tradicional.
BHUTA YADNA SEBAGAI AJANG PELESTARIAN ALAM DI BALI
Authors: Yusuf M.
Published: June 2020

Human life can not be separated from the natural world around it. Nature is the main source of humans to connect the chain of life. Suber food basically comes from nature which is then processed in such a way by humans. That way, it is very necessary to have actions that are caring and conserving nature so that it is maintained. In Hinduism, there is the term Panca Yadnya which contains the worship or sacrifice which is done sincerely and sincerely from the heart. One of the elements of the five Yadnya is done to the Butha to preserve nature and harmony of human life during the world called the Bhuta Yadnya. In another sense, Bhuta Yadnya is an offering made with the welfare of plants. Of course this is also related to natural conditions which are an important component in supporting the survival of human life. The relationship between nature and humans is inseparable because the two are interrelated, therefore, it is necessary to have a reciprocal relationship in maintaining a balance between the two. In this paper, it explains about the role of the Panca Yadnya ceremony or the five types of sacrifices performed in Hindu beliefs, especially regarding the Bhuta Yad whose role is to preserve nature. In undergoing the life cycle of the world, humans play an important role in preserving the surrounding natural preservation.
ENVISIONING FUTURE DIRECTIONS IN PUBLIC RESOURCES
Authors: Mazzetto Silvia
Published: June 2020

During the civil war (1975-1992), Lebanon faced total destruction that produced a negative impact on the urban growth of the Lebanese cities. The war generated some paralyzes that still produce adverse effects on the Lebanese people. Public infrastructure, public spaces, and the national public heritage, which are fundamental resources of the Lebanese society, currently are still not properly safeguard and managed by the local government. Understanding and enhancing the values of the Lebanese public resources is an indispensable tool for the development of the contemporary Lebanese society that can influence the future expansion, the revitalization and the shaping of new contemporary urban planning approach. How can we envision the future directions of the Lebanese public resources to influence the development of the Lebanese country while advocating for sustainable cities? This research tries to identify the main values, trends, influences, and ideologies linked with the public values, that should be considered and adopted to shape the development of contemporary growth in Lebanon.
INFLUENCE OF VERTICAL GARDENS ON THE AIR QUALITY OF A CITY HISTORIC CENTER
Authors: Ramirez Francisco , Chuquer David , Vallejo Espinosa Andrea , Davis Michael Maks
Published: June 2020

Quito is an Andean city with 2.7 million inhabitants that regularly exceeds the WHO air quality guidelines for O3, SO2, PM2.5, and PM10. Within the historic center in an area of 920.000 m2, only 4% is green space. However, 14.000 m2 of vertical walls exist that could potentially host vertical gardens. The present study evaluates the ability of four vertical gardens to improve air quality and quantifies the area of viable spaces to host vertical gardens in the Historic Center. The air quality was monitored with continuous measuring systems near each vertical garden and in areas outside the area of influence. The capacity for retention of gaseous emissions from an internal combustion engine in an active garden was also evaluated. The results were a mixture of advantages and uncovering possible myths: a) the presence of vertical gardens causes a significant decrease in O3 (up to 99%), NO2 (up to 80%), SO2 (up to 83%), PM2.5 (up to 79%) and PM10 (up to 85%); b) however, a poor choice of plant species in vertical gardens may increase the formation of O3; and c) in the case of exposing an active vertical garden to emissions injected directly into the garden by a combustion engine, the particle size distribution influences its removal, being more efficient with a size greater than 4 μm but not effective for smaller diameters.
A SYNTHESIS OF CONSTRUCTABILITY IN TRANSPORTATION CONSTRUCTION
Authors: Minchin R. Edward , Myers Mackie , Tran Dan , Tian Yifeng
Published: June 2020

The problem of “constructability” was successfully addressed by leading researchers in the early 1990s, and was considered a problem in remission for over a decade afterward. Constructability, at that time, was seen as the level of difficulty faced by a constructor (usually a contractor) in building a structure in the field as drawn by the designer. Many contractors in those days found it impossible to build the project as drawn and directed. Researchers then devised what became known as the Constructability Review Process, and state Departments of Transportation (DOTs) took up their recommendations as each agency saw fit. This review process drastically reduced obstacles to the point that constructability was no longer viewed as a problem. Then, however, came the proliferation of fast-track, integrated construction delivery systems in the transportation construction industry, with early contractor involvement in the design inherent in these delivery methods. About the same time, DOTs were inundated with new requirements for procuring environmental permits prior to construction, as well as an additional process required by the National Environmental Protection Act. Constructability, with these new requirements, has returned as a problem. This paper reports on a survey conducted as part of a research project funded by the National Cooperative Research Program to determine how each of the 52 DOTs in the US are confronting this problem.
THE FACTORS MILITATING INTERNAL STAKEHOLDERS ON ROAD INFRASTRUCTURE PROJECTS
Authors: Mashwama Nokulunga Xolile , Mushatu Winnie , Thwala Didibhuku , Aigbavboa Clinton
Published: June 2020

There are numerous participants involved in construction projects including the client or sponsor of the project, regulatory bodies, contractors, consultants, ward councilors, community who affect or become affected by the project. Stakeholders can affect the road construction positive or negatively. Stakeholder’s engagement is done to avoid unnecessary conflicts and controversies and to attain the desired successful implementation of the project. The paper aims to identify the impact of internal stakeholders on road construction project. Quantitative approach was adopted for this study. 100 questionnaires were distributed and 76 were collected and analyzed. The data was collected through primary and secondary sources. Factor analysis was conducted, Correlation matric coefficients has been conducted to ensure visibility of coefficients greater than 0.3 and Kaiser-Meyer-Olkim (KMO) and Barlett’s test were conducted. From the findings it transpired that late payment to service providers; failure to verify contractor qualification; Client knowledge to review design documentation; inadequate involvement during construction project, lack of understanding project feasibility. The participation of stakeholders encourages the public to share their knowledge with the regulatory authorities, fosters better-informed decisions and decreases likelihood of project failure. Early stakeholder’s involvement can add benefits of diffusing opposition to a project.
OVERVIEW OF SAFETY PERFORMANCE IN THE CONSTRUCTION INDUSTRY
Authors: Mahmoud Abubakar Sadiq , Hamdan Ahmad Mohd. , Mohd. Yatim Yahya
Published: June 2020

The construction industry is one of the most dangerous industries worldwide due to deadly fatalities and accidents recorded yearly, compared to other sector of the economy in many countries. Though many safety programs have been established and implemented, the situation does not seem to have been mitigated the menace of accidents. Developing countries, like Nigeria, still lack laws and regulations on health and safety practices. The health and well-being of construction workers are being threatened by the increasing cases of injuries and casualties recorded at construction sites. The construction industry in Nigeria is also labor intensive with labor cost running between 40 to 65% of the total project cost. Operators are majorly categorized into multinational and indigenous construction companies. Indigenous companies in Nigeria are involved in an estimated 50-100% public and private clients in both traditional and non-traditional systems of procurement. However, indigenous companies’ record 2 and 5 percent accident and injury level among workers with 300% more risk than the multinationals. Thus, this paper aims to provide an overview of the construction safety performance and construction stakeholders’ operations in the construction industry of Nigeria. The overview is of potential benefit to the administrators of building development, building designers and policy makers.
QUO VADIS CIVIL ENGINEERING EDUCATION: 20 YEARS AFTER BOLOGNA DECLARATION
Authors: Quapp Ulrike , Holschemacher Klaus
Published: June 2020

The Bologna Declaration of 29 European Higher Education Ministers caused the most inventive change on the higher education sector all over Europe since more than 200 years. The objective was to create a common European Higher Education Area with permeability, higher transparency and acceptance of university degrees across Europe. Since the declaration’s signing in 1999, the bachelor and master’s degrees successively replaced the former study program system of European universities and quality assurance methods were implemented. 20 years after the signature of the agreement, it is time to look back. The authors analyzed advantages as well as disadvantages of the modifications in the German study program structure and other related changes from the current state of view. Furthermore, the paper will give information whether objectives of the Bologna Declaration have been met and where the expected success is still being missed. For that, the paper provides information about the current study structure in Germany, students’ statistics and development of academic mobility. Focus of the investigation was civil engineering programs as well as the resulting developments in universities’ and faculties’ management of German higher education institutions. The authors concluded that the main ideas of the Bologna Process found their way in the daily work of the universities. Nevertheless, the higher education reformation has not yet reached its aims.
BREAKING STUDENTS’ COMFORT ZONE: LEARNING FROM COMMUNITY MEMBERS, A STRATEGY WITHIN THE AEC EDUCATION
Authors: Villacis Tapia Enrique Vinicio , Luxton India , Valdes Vasquez Rodolfo , Ozbek Mehmet Egemen , Ayarza Cynthia
Published: June 2020

In order to address pressing issues such as climate change, energy crises, and economic disparity, it is pertinent to include local community members within AEC education. In this paper, we explore how breaking the comfort zone of students can facilitate a broader perspective on sustainability. This new perspective can cultivate innovative and creative solutions to 21st century problems. This paper documents the experience and impacts of student participation in an education abroad program focused on sustainable buildings and infrastructure. The program took place in January 2019 in Costa Rica with the collaboration of Colorado State University (USA) and EARTH University (Costa Rica). In this program, students directly communicate with low-income community members who worked with a local developer during the construction of a new neighboring building. Qualitative interviews with students, as well as ethnographic observations of class discussions, illustrates that this partnership helped students see a new perspective on how to deal with the life cycle of construction projects. The preliminary results indicate that the collaboration between the community members and the developer was a key component of expanding students’ perspectives. This research illustrates the importance of building community collaborations that are mutually beneficial in the classroom and beyond. In particular, the results suggest that educational experiences which integrate community concerns into solutions are key to expanding students’ worldviews.
CRUSHED LIMESTONE SAND: AN EFFECTIVE ALTERNATIVE TO NATURAL SAND IN CONCRETE
Authors: Abi Farraj Faten , Vidal Thierry , Cubaynes Marie-Pierre , El Barrak Maher , Hage Chehade Fadi , Escadeillas Gilles
Published: June 2020

Due to its scarcity and the detrimental environmental effect of its extraction, leading to governmental restrictions, the good quality natural rounded siliceous sand became less available in Lebanon. This national and international issue affects the construction industry through the cost and the quality of concrete. Currently, this sand, too fine to be used alone as fine aggregate in concrete mixes, is always mixed with an appropriate percentage of crushed limestone sand to meet the standard grading. The objective of the study is to assess the feasibility of total replacement of natural rounded siliceous sand by crushed limestone sand to avoid the dependency of the construction field on the quality and availability of this material in the Lebanese context. The research program consists of proposing various concrete mixes without natural sand and verifying, following a performance-based approach, that their behaviors can be maintained, at different ages of hardened states, compared to those of the reference concrete incorporating natural sand. The resulting comparisons allow identifying the influences on compressive and flexural strengths of natural sand substitution and of the variations of granular size distribution. At this stage of the study, some preliminary conclusions about the applicability of the solution of natural sand total substitution are proposed.
WATER VAPOR TRANSPORT IN PLASTERS CONTAINING SUPERABSORBENT POLYMERS
Authors: Fořt Jan , Mildner Martin , Hotěk Petr , Černý Robert
Published: June 2020

A proper characterization of material properties represents an important step towards an efficient building design. Considering the present issues in the construction sector, moisture loads pose a risk not only to increased material deterioration but also to the health of building inhabitants. In this paper, modified plaster mixtures with superabsorbent admixture are designed in order to improve passive moderation of finishing layers against varying humidity conditions. The relationship between the amount of applied superabsorbent admixture and resulting water vapor transport properties is identified and the influence of temperature on water vapor transport is analyzed. The steady-state cup method is used for the determination of water vapor transport properties, namely the water vapor diffusion permeability, water vapor diffusion coefficient and water vapor diffusion resistance factor. The obtained data show temperature as a very significant factor affecting water vapor transport in the analyzed plasters. Considering the dry-cup method arrangement, relative humidity probes should be used for monitoring relative humidity under the sealed sample for a sufficiently precise determination of water vapor pressure gradient.
MAGNESIUM OXYCHLORIDE CEMENT-BASED COMPOSITE WITH FOAM GLASS USED AS LIGHTWEIGHT ADMIXTURE
Authors: Pivák Adam , Marušiak Šimon , Záleská Martina , Pavlík Zbyšek , Pavlíková Milena
Published: June 2020

In this paper, foam glass was used as an aggregate in magnesium oxychloride cement (MOC)-based mixtures. Magnesium oxychloride cement is known as a non-hydraulic, high-strength, and fire-resistant binder that can bond large amounts of miscellaneous fillers. In comparison with Portland cement, MOC has a lower environmental impact over its whole life cycle. The purpose of this paper is to modify thermal and hygric properties of MOC-based composites using lightweight mineral admixture, namely foam glass, and hydrophobic agents. The raw materials were analyzed by XRF spectroscopy and their basic properties characterized. The MOC composites were by their basic material, mechanical, thermophysical, and moisture properties described. Considerable improvement of thermal parameters of MOC composite modified with the foam glass and obvious action of surface hydrophobic agent as moisture barrier were observed. The resulting thermal-insulating, lightweight MOC composite with suitable mechanical properties can be used in the construction of thermal insulation surfaces and envelopes, ceiling or wall panels, reducing the energy consumption of buildings.
A SEQUENTIAL AUGMENTED METAMODELING METHOD FOR ENGINEERING RELIABILITY ANALYSIS
Authors: Wang Qian , Ji Jun
Published: June 2020

Metamodeling methods provide useful tools to replace expensive numerical simulations in engineering reliability analysis and design optimization. The radial basis functions (RBFs) and augmented RBFs can be used to create accurate metamodels; therefore they can be integrated with a reliability analysis method such as the Monte Carlo simulations (MCS). However the model accuracy of RBFs depends on the sample size, and the accuracy generally increases as the sample size increases. Since the optimal sample size used to create RBF metamodels is not known before the creation of the models, a sequential RBF metamodeling method was studied. In each iteration of reliability analysis, augmented RBFs were used to generate metamodels of a limit state or performance function, and the failure probability was calculated using MCS. Additional samples were generated in subsequent analysis iterations in order to improve the metamodel accuracy. Numerical examples from literature were solved, and the failure probabilities based on the RBF metamodels were found to have a good accuracy. In addition, only small numbers of iterations were required for the reliability analysis to converge. The proposed method based on sequential RBF metamodels is useful for probabilistic analysis of practical engineering systems.
TORSIONAL STIFFNESS AS AN INFLUENCE PARAMETER ON ARCH STABILITY
Authors: Van Bogaert Philippe , Van Staen Gilles , De Backer Hans
Published: June 2020

Arch bridge springs can be connected to concrete abutments either by prestressing bars or by connectors. In both options, the torsional stiffness is substantially reduced, compared to the full arch cross sectional area. The influence of this lack of torsional stiffness on arch buckling is being researched, both numerically and experimentally. To reduce any residual stress during tests, wooden rods that simulate the arch were submerged in water and subsequently bent to the desired shape. Imperfections of the arch samples are measured. Two unequal concentrated loads are applied to the samples, thus simulating the effect of movable loads across half of the arch span. During loading, lateral deflections were measured until elastic buckling occurred. The simulation of more flexible rotation of the springs required replacing the cross section by thin equivalent side plates. Since all parameters have not been isolated, the results are limited yet. However, comparing the failure load of similar conditions, the reduction of torsion stiffness by 81.48% reduces the failure load by 26.3%. This indicates that total prevention of axial rotation may not be imperative for arch bridges.
APPLICATION OF STRUT-TIE-METHOD (STM) TO RETROFIT AN EXISTING FOUNDATION ANCHORAGE
Authors: Jiang Ping , Khan Pradip , Zhou Lei
Published: June 2020

A strut-and-tie model (STM) is an ultimate strength design method based on the formation of a hypothetical truss elements that transmit forces from loading points to supports. The STM utilizes concrete struts to resist compression and reinforcing ties to carry tension. Design using STM involves calculating the required amount of reinforcement to serve as the tension ties and then checking that the compressive struts and nodal zone (joints) are adequate to support the forces. A key advantage of design using STM is that the designer can visualize the flow of stresses in the member. This paper presents the basic concepts, assumptions and approaches using STM to perform the calculation and design for the existing foundation anchor retrofit based on a real application in high seismic zone. The analysis also includes up-to-date finite element modelling techniques for the machine base plate the anchor rods connection to the concrete foundation subjected to large forces (tension and shear).
COMPUTATIONAL ANALYSIS OF HEAT AND MASS TRANSPORT IN CHARACTERISTIC DETAIL OF INTERIOR THERMAL INSULATION SYSTEM
Authors: Maděra Jiří , Kočí Jan , Kočí Václav
Published: June 2020

Computational modeling represents useful tool for the assessment of newly designed or refurbished building materials and structures. Especially, when complex buildings elements need to be assessed from a hygrothermal point of view, the computational modeling is the right approach with desired power and accuracy. In this paper a historical wall element is investigated using two-dimensional simulation in order to study the effect of application of several insulation materials in various scenarios. In total two insulation materials are investigated (mineral wool, wood fiber boards) that are applied in three different scenarios. All simulations are performed under real climatic load. The results of the computational simulations reveal potential weak points in system application and can provide engineers and designers with valuable recommendations and practical information. The best results were obtained for thermal insulation from mineral wool. On the other hand, an improper system application can lead to a significant devaluation of the beneficial effects on the thermal performance of the studied brick element.
ALTERNATIVE DESIGNS OF MOLTEN SALT STORAGE SHELLS FOR USE IN SOLAR ENERGY STORAGE
Authors: Loyd Nathan , Ladkany Samaan
Published: June 2020

Molten salt (MS) storage systems in the 565°C range can store green solar energy from thermal solar power station, such as the Crescent Dunes solar plant in Nevada. Large containers can be used to store energy and generate electricity for eight hours or more to be used at night or during peak demand hours, depending on the container size. Energy storage can reduce the fluctuation due to weather conditions experienced at thermal solar power stations because stable diurnal energy supply is made available by MS energy storage. Supported by the Office of Naval Research (ONR), the research presented discusses the considerations for designing molten salt storage tanks. An alternate molten salt storage cylindrical tank design layout is presented, including an improved roof design concept. A preliminary heat transfer analysis is presented and discussed for the alternate cylindrical tank design. This preliminary analysis was used to determine the thickness of insulating material in and around the cylindrical tank to reduce heat flux. These insulating materials include the use of firebrick and ceramic insulation to complement the structural carbon steel and the stainless steel that is used for corrosion resistance. This paper also introduces the alternate designs of a semi-buried spherical tank and drop shell tank that can be used storing molten salts.
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE EFFECT OF SIZE IN POST-TENSIONED CONCRETE DECK SLABS
Authors: Amir Sana , van der Veen Cor , de Boer Ane
Published: June 2020

It is widely known that as the structure of the size increases, its nominal strength decreases. In this paper, the effect of size on punching shear has been quantified for transversely post-tensioned deck slabs cast between flanges of precast concrete girders. A 1:2 scaled model of the bridge was constructed in the laboratory, and experimental and numerical analyses were carried out. However, in order to apply these results on a real bridge, simply using the geometrical scale factors is not sufficient and a structural size effect has to be taken into account. Since a full-scale experimental study was not possible due to the costs involved, a numerical approach using finite element analysis software package TNO DIANA was used to model both the prototype and the real bridge, and a comparison was made to estimate the effect of size on the bearing capacity. It was found that increasing the transverse prestressing level had a positive effect on the punching shear strength of the deck slab. Furthermore, a lower size effect was observed with higher transverse prestressing levels. It is concluded that if a suitable size factor is used, either numerical or small-scale experimental studies can be reasonably used to investigate existing structures.
Tablet alebo notebook? Komparatívna štúdia žiakovho vnímania rozdielnych technologických prístupov v počítačom podporovanom chemickom laboratóriu
Authors: Skoršepa Marek , Kmeťová Jarmila , Horváthová Erika
Published: June 2020

Školské experimentovanie s podporou výpočtovej techniky je v relevantnej literatúre už niekoľko desiatok rokov prezentované ako jeden zo sľubných prístupov v štúdiu prírodných vied. Technológie však podliehajú veľmi častým a rýchlym zmenám, a preto aj v oblasti počítačovej podpory laboratórnej činnosti žiakov možno za posledné obdobie sledovať rôzne technologické riešenia. V tomto príspevku sa zaoberáme komparáciou žiackeho vnímania experimentovania s dvomi rozdielnymi koncovými zariadeniami: (i) notebookmi a (ii) tabletmi, ako súčastí rovnakého typu meracieho systému. Pre účely štúdie sme vytvorili sadu štyroch počítačom podporovaných aktivít z chémie, ktoré boli realizované dvomi skupinami žiakov slovenských gymnázií. Kým prvá skupina pracovala s meracími systémami, kde boli ako koncové zariadenia použité notebooky, druhá skupina pracovala na rovnakých aktivitách s tabletmi. Cieľom štúdie je zistiť, či rozdielne technologické prístupy majú potenciál generovať štatisticky významné rozdiely vo vnímaní tohto typu experimentovania samotnými žiakmi.
Mathematical Thinking Styles and the features of Modeling Process
Authors: Shahbari Juhaina Awawdeh
Published: June 2020

The current study investigated the relationship between students’ mathematical thinking style and their modeling processes and routes. Thirty-five eighth-grade students were examined. In the first stage, the students solved questions, and according to their solutions, they were assigned to one of two thinking style groups: visual and analytic. The two groups engaged in three modeling activities. Findings indicated differences in the groups’ modeling processes in performing the three activities. The primary differences in the modeling processes were manifested in simplifying, mathematizing, and eliciting a mathematical model. In addition, the analytic thinking group skipped the real-model phase in the three activities, while the visual group built a real model for each activity.
The Act on Counteracting Food Waste – an attempt of its evaluation
Authors: Sokołowski Łukasz Mikołaj
Published: June 2020

The article is a voice in the discussion on the legitimacy of the solutions adopted in the Act on Counteracting Food Waste. The author assesses both the direction of the legislator’s actions as well as individual legal instruments provided for in the new regulations. Despite many critical comments and objections to the solutions adopted, adoption of separate legal regulations in this respect should be assessed positively. The measures taken may constitute the first steps on the way to the implementation of comprehensive solutions, being at the same time a manifestation of the legislator’s efforts to ensure food sovereignty, based among other things on a closed-circuit economy.