bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation Propagation in Multistage Machining Processes Using Dual Quaternions
Authors: Yacob F , Semere D 
Published: November 2019

Abstract
The application of rigid transformations matrices in variation propagation has a long tradition in manufacturing community. However, the matrix-based modeling of variation propagation in multistage machining processes is complicated. Moreover, there is a need to improve the computational efficiency of manipulation of geometrical models for variation analysis purposes. This paper introduces the representation of rigid transformation by dual quaternions, which have a computational advantage and mathematical elegance compared to matrices. In comparison to a commercial tool, the implementation of the purposed method predicted parallelism with an average error of 4.3 % in a hypothetical two stage machining process. The proposed approach has a potential to be an alternative to matrix based rigid transformation practices in variation and tolerance analysis.
Testing of a new transport and installation method for offshore wind turbines
Authors: Haugvaldstad J , Gudmestad O T 
Published: November 2019

Abstract
Transport and installation of offshore wind turbines require considerable efforts and can be time consuming, in particular when jackups are used for lifting operations. This is mainly due to the specific weather window requirements for towing and locating the jackups. A goal is ultimately to finalize all turbine assembly work onshore and at quayside and to transport the completed turbine to the site for easy installation. We suggest that this can be achieved by a transport and installation method we denote “the MINT method” whereby the wind turbine foundation is located on a barge while the tower is resting on a support system, a “MINT” system that is located at the stern of a mid-size standard offshore support vessel. The MINT is specifically designed for the transport and installation operations allowing relative motions and rotations between the tower and the transport vessel. In order to qualify the “MINT installation method”, a numerical study of the feasibility of the transport and installation was carried out by Sintef Ocean using their SIMO software package [1]. The method was found feasible in favourable weather conditions. To further document feasibility, it was decided to carry out a proof of concept test in a wave tank to identify concerns with respect to the suggested method for transport and installation. This paper reports the findings of this test. The test is to be considered to represent an initial activity in the concept qualification process, see [2], and is not a full wave tank test carried out to measure stresses and strains for member sizing. The objective of the paper is therefore, to show how an initial wave tank test can be useful for concept qualification.
The influence of an unstable turbulent wind spectrum on the loads and motions on floating Offshore Wind Turbines
Authors: Knight J M , Obhrai C 
Published: November 2019

Abstract
Floating offshore wind turbines (FOWT) are exposed to harsh environmental conditions and often experience unstable atmospheric conditions. Including the effects of atmospheric stability should improve the accuracy of fatigue load calculations, and subsequently, the design of the wind turbine. The current standards recommend two turbulence spectral models that are valid for neutral atmospheric conditions only. The objective of this study is to investigate the influence of Hejstrup’s 1981 Unstable Spectra Model on the loads and motions on a spar and a semi-submersible FOWT. This study focuses on the effect of unstable atmospheric conditions in the free stream wind and does not include the effect of wakes. The most significant differences observed in this study were for the tower top torsion loads, where very unstable conditions gave 47% larger loads than neutral conditions for OC3-Hywind turbine and 30.4% larger for OC4-DeepCwind turbine. Since very unstable conditions corresponded to the highest turbulence intensities and larger turbulent fluctuations, they also resulted in higher fatigue loads. The blade root flap-wise loads were also observed to be higher under unstable conditions compared to neutral conditions, but the differences were smaller with 7.5% for OC3-Hywind and 23% for OC4-DeepCwind.
Investigation of transitional turbulence models for CFD simulation of the drag crisis for flow over a sphere
Authors: Nakhostin S M , Giljarhus K E T 
Published: November 2019

Abstract
The drag crisis is an interesting physical phenomenon for flow over bluff bodies, where the drag coefficient suddenly drops as the Reynolds number increases. This behavior is caused by the flow transitioning from laminar to turbulent flow in the boundary layer. The turbulent flow remains attached to the surface longer than the laminar flow, thereby reducing the size of the wake behind the body. The phenomenon has been extensively studied experimentally for simple geometries such as flow over a sphere or a cylinder. Numerical simulations, however, have mainly been performed in either the subcritical or the supercritical region. In this study, we investigate the ability of steady-state RANS CFD models to predict the drag crisis for flow around a sphere. Experiments using oil-film visualization are performed to determine the type of transition for flow over a sphere. Simulations are performed using OpenFOAM, with the k-ω shear stress transport (SST) turbulence model. For transition modelling, the Langtry-Menter modification to the SST model is considered. The simulations show improved prediction of the drag coefficient in the subcritical regime, but the implementation of the model is found to be unstable in the critical and supercritical range.
Effects of an inserted circular cylinder on a steady lid-driven rectangular cavity flow
Authors: Zhu J , Holmedal L E , Myrhaug D 
Published: November 2019

Abstract
This paper provides numerical investigations of flow in a steady lid-driven cavity of depth to width ratio 1/3 containing a circular cylinder. The inner cylinder is treated using a direct-forcing immersed boundary method, and a project method is applied to solve the incompressible Navier-Stokes equations. Three different Reynolds numbers and positions of the cylinder are considered; for a lower Reynolds number, flow structures are weakly affected by the cylinder near the left wall while two clockwise vortices attached to the cylinder are formed as the cylinder moves rightwards; for a moderate Reynolds number, an anticlockwise bottom vortex is formed for the cylinder near the left wall, and it disappears as the cylinder is shifted rightwards; for the largest Reynolds number, two anti-clockwise vortices attached the cylinder are formed for the cylinder close to the left wall, and as the cylinder moves gradually closer to the left wall a bottom vortex is formed and disappears together with the clockwise vortex to the right side of the cylinder.
Environmental and sustainable aspects of green building: A review
Authors: Çiner F , Doğan-Sağlamtimur N 
Published: November 2019

Abstract
Public and scientific focus of interest on climate changes, population increase, rapid urbanization is rising day by day. Thus, increased demand for green buildings that reduces negative impacts, and can creates positive impacts on climate, natural environment and sustainable development is a new topic. Green buildings must be not only eco-friendly (efficiently use energy, water, and other resources, use renewable energy, reduce pollution and waste, enable reuse and recycling, have good indoor environmental quality, use of materials that are non-toxic, ethical and sustainable) but also function as the key part to provide a comfortable working/living environment for human activities and improve quality of life. It is realised that green buildings as a worldwide response to raise awareness of the role of human activity in global climate changes, with maximum expression in Leadership in Energy and Environmental Design (LEED) Certification and its five basic requirements: Sustainable Space (SS), Materials and Resources (MR), Energy and Atmosphere (EA), Environmental Quality (EQ), and Water Efficiency (WE).The aim of this study is to review the environmental and sustainable aspects of green buildings. For this goal, environmental and sustainable aspects of green building including its origin, concept, eco-friendly properties, benefits, tools, rating systems, certifications are given and discussed in detail in this study.
Building panel production incorporated with fly ash
Authors: Yıldırım G , Keser H , Doğan-Sağlamtimur N , Çelik F 
Published: November 2019

Abstract
With the increase in industrialization, the amount of fly ash (FA), which is one of the industrial solid wastes causing environmental and human health problems, is increasing day by day. Waste valorization and reuse methods need to be developed for this waste ash. The construction industry is the main sector where it is used. In this study, it is aimed to evaluate the usability of industrial FA in the production of economical and useful building panels and to determine their physical-mechanical properties. FA supplied from İsken Sugözü Thermal Power Plant (ISTPP), ordinary Portland cement (OPC) supplied from ÇİMSA Cement Industry and Trade Inc., molding plaster (MP) and lime are the materials of this study. Particle distribution curves were determined by using laser scattering method for FAISTPP. In this study, compressive and flexural strengths, water absorption, bulk density and porosity as mechanical and physical tests were made in the building panels having the combination of FAISTPP+cement FAISTPP+MP and FAISTPP+lime in contribution ratios of 10, 30, 50, 70 and 90%FAISTPP. The results of the experiments show that the highest compressive strengths values in 7 and 28 days found in the building panels having combination of 90% cement+10% FAISTPP are 57.30 and 64.20 MPa, respectively. It was determined that the value-added building panels could be produced from FAISTPP, an industrial solid waste, in the appropriate proportions of cement contribution.
Fly ash as a raw material for geopolymerisation-mineralogical composition and morphology
Authors: Korniejenko K , Łach M , Marczyk J , Ziejewska C , Halyag NP , Mucsi G 
Published: November 2019

Abstract
The article discusses the main features fly ashes (FAs) as a raw material for geopolymerisation taking into consideration mineralogical composition and morphology. It is continuation the previous research connected with chemical composition and physical properties. This article is focused on the examination of a FA from the CHP plant in Skawina (Poland) and assessment it as a main component for geopolymers production. The characteristic of the FA is presented, including the morphology and mineralogical structure. The morphology was examined using Scanning Electron Microscopy (SEM). The structure of the FA was monitored also by Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray diffraction (XRD).
Evaluation of fire, high-temperature and water erosion resistance of fiber-reinforced lightweight pozzolana-based geopolymer mortars
Authors: Silva G , Salirrosas J , Ruiz G , Kim S , Nakamatsu J , Aguilar R 
Published: November 2019

Abstract
The development of new building materials requires intensive analyses of their durability under aggressive conditions. Therefore, the current study evaluated the capacity of a fiber-reinforced lightweight pozzolana-based geopolymer mortar to resist the action of fire, high temperatures and water erosion. The fire resistance and heat absorption capacity were evaluated through the exposure of disc samples to a direct flame at 1000 °C and the measurement of reverse-side temperature, respectively. To evaluate the high-temperature resistance, uniaxial compression tests were performed on cubic samples after their exposure to oven-temperatures of 300°C, 500°C, 800°C, and 1000°C. Finally, water jet erosion and permeability tests were performed to analyze the interaction of the material with water. The results of the fire tests indicate that fiber-reinforced lightweight pozzolana-based geopolymer mortars are able to absorb up to approximately 65% of heat flame with only slight degradation. On the other hand, uniaxial compression tests showed a temperature resistance up to 800°C, above this temperature the cubic samples experimented significant volumetric changes that might have been caused by a reaction of remaining hydrogen peroxide or gas expansion. Finally, water exposure tests showed that the material is highly permeable and has a remarkable resistance to water erosion.
Utilization of innovative system for coke oven wastewater treatment as an element of stabilization technology for post-process waste from municipal incineration plants
Authors: Mierzwiński D , Łach M , Mikuła J , Furtos G , Korniejenko K 
Published: November 2019

Abstract
The article discuss the possibility of using the system for coke oven wastewater treatment process that has been developed within the framework of the project: The innovative system for coke oven wastewater treatment and water recovery with the use of clean technologies — INNOWATREAT that has received funding from the Research Fund for Coal and Steel under Grant Agreement No. 710078 and from the Ministry of Science and Higher Education Poland from financial resources on science in 2016-2019, for the removing the hazardous elements and compounds from wastewater from leaching ashes from municipal waste incineration plants. The results achieved in the project are compared with analysis provided for two different sources of ash from Poland and one Lithuania. The article discuss predicted effectiveness of the method and possibility their use in wider method of post-process waste stabilization technology as well as potential risk connected with implementation this solution into practice.
Stretchable multifunctional dielectric nanocomposites based on polydimethylsiloxane mixed with metal nanoparticles
Authors: Feng Pengdong , Zhong Mao , Zhao Weiwei 
Published: November 2019

Abstract
Next generation wearable electronics require stretchable dielectrics. There has been significant effort to characterize and improve the components of dielectric composites for use in these devices. In this work, a new stretchable dielectric material, composited by silver nanoparticles (Ag NPs), nickel nanoparticles (Ni NPs), and polydimethylsiloxane (PDMS), is prepared and characterized. The alternating arrays of Ag NPs groups and Ni NPs groups in the three-dimensional matrix of PDMS function as micro capacitors and prevent current percolation. Compared with PDMS alone, the alternating arrays exhibit a dielectric constant (
k
) that is increased by 1146% and can reach 35.13, with dielectric loss as low as 0.009. Slightly lower
k
and larger dielectric loss appear at high frequencies. The material exhibits negative temperature dependence, and the composition ratio affects the dielectric properties. The strain at break is 139.68% and the elastic modulus is as low as 3.57 kPa. By controlling the type, size and dispersion of metal nanoparticles in PDMS matrix, a parallel-plate capacitor with constant capacitance is achieved, demonstrating the dependence of the dielectric constant on the applied strain. Moreover, by replacing the parallel plates with cylindrical fibers, a capacitive strain sensor was demonstrated. After hundreds of stretching-releasing cycles, the dielectrics work normally. The excellent properties of this material suggest its significant potential for use in wearable electronics.
Textile band electrodes as an alternative to spot Ag/AgCl electrodes for calf bioimpedance measurements
Authors: Wang Ke , Zelko Dylan , Delano Maggie 
Published: November 2019

Abstract

Objective:
To evaluate the performance of five different types of textiles as band electrodes for calf bioimpedance measurements in comparison with conventional spot Ag/AgCl electrodes.
Approach:
Calf bioimpedance measurements were performed in 10 healthy volunteers with five different textile materials cut into bands and Ag/AgCl spot electrodes as a baseline. Collected bioimpedance data were analyzed in terms of precision, fit error and presence of measurement artifacts. Each textile material was also evaluated for participant comfort.
Main Results:
Bioimpedance values for spot electrodes were higher at low frequencies as compared with band electrodes but not at high frequencies. This suggests that spot electrodes have frequency dependent current distributions that adversely impact their use for volume measurements and band electrodes are preferable. The SMP130T-B fabric had the highest precision and the lowest best fit error to the Cole model of the tested textile materials. However, it was the least comfortable textile and most expensive. The Stretch material performed slightly worse than the SMP130T-B fabric, but was half the cost and the most comfortable.
Significance:
These results suggest that there are suitable textile materials for use as dry, band electrodes for calf bioimpedance measurements and that these band electrodes enable greater current uniformity. These textiles could be integrated into a compression sock for remote monitoring of diseases such as Congestive Heart Failure.
Cytokine Network and Sexual Human Immunodeficiency Virus Transmission in Men Who Have Sex With Men
Authors: Vanpouille Christophe , Frick Andrew , Rawlings Stephen A , Hoenigl Martin , Lisco Andrea , Margolis Leonid , Gianella Sara 
Published: November 2019

Abstract

Background
Seminal human immunodeficiency virus (HIV) transmission from men to their partners remains the main driver of HIV epidemics worldwide. Semen is not merely a carrier of the virus, but also provides an immunological milieu that affects HIV transmission.

Methods
We collected blood and semen from people with HIV whose epidemiologically linked sexual partners either did or did not acquire HIV. Viral transmission was confirmed by phylogenetic linkage (HIV pol). We measured the concentration of 34 cytokines/chemokines by Luminex in the blood and semen of 21 source partners who transmitted HIV (transmitters) and 22 who did not transmit HIV (nontransmitters) to their sexual partners. Differences between cytokine profiles in transmitters versus nontransmitters were analyzed using the multivariate statistical technique of partial least square discriminant analysis.

Results
The cytokine profile in seminal fluid, but not in peripheral blood, was significantly different between men who have sex with men (MSM) who transmitted HIV and those who did not transmit HIV to their sexual partners (E = 19.77; P &lt; .01). This difference persisted after excluding people with undetectable HIV RNA levels in nontransmitters.

Conclusions
Seminal cytokine profiles correlated with transmission or nontransmission of HIV from the infected MSM to their partners, independently from seminal viral load. Seminal cytokine spectra might be a contributing determinant of sexual HIV transmission, thus providing new directions for the development of strategies aimed at preventing HIV transmission.
The antioxidant and physicochemical properties of microencapsulated bioactive compounds in Securigera securidaca (L.) seed extract by co-crystallization
Authors: Nik Ali Behnam , Vazifedoost Mohsen , Didar Zohreh , Hajirostamloo Bahareh 
Published: November 2019

Abstract
Securigera securidaca seed is a good source of phenolic compounds with high antioxidant properties. Preservation and maintenance of natural antioxidants have always been a challenge and microencapsulation is a suitable method for this purpose. In this study, the chemical compounds of the plant seed extract were identified by GC/MS device. Bioactive compounds from the seed ethanolic extract were microencapsulated in the sucrose matrix during the co-crystallization process. The evaluations included total phenolic compounds, radical scavenging ability, production efficiency, moisture content, and flowability characteristics of the produced powders, such as compressibility index, Hausner ratio, and angle of repose. The results showed significant differences in the phenolic compounds and the radical scavenging ability between the control sample and the co-crystallized powder (P &lt; 0.05). The production efficiency and the moisture content of extract-containing co-crystallized powder were 84% and 0.14%, respectively. The particle size difference of the microencapsulated powder could significantly affect the powder flowability characteristics (P &lt; 0.05), and particles with a size of 1 mm showed better flowability behaviour. FT-IR charts for samples revealed chemical bonds specific to saccharose molecule indicating no changes in covalent bonds present in saccharose molecule structure after the process. Scanning electron microscope images showed the presence of vacant spaces and porosity in the structure of saccharose crystals formed during the process of crystallization. As a result, the co-crystallized powder obtained from the plant extract can be used as an appropriate antioxidant in the food and pharmaceutical formulations.
Childlessness and Health Among Older Adults: Variation Across Five Outcomes and 20 Countries
Authors: Quashie Nekehia T , Arpino Bruno , Antczak Radoslaw , Mair Christine A 
Published: November 2019

Abstract

Objectives
No previous study to the best of our knowledge has examined the association between childlessness and health using a wide range of countries and health outcomes. This study improves previous literature by examining the relationship between “childlessness” (1 = childless for any reason, 0 = parent of biological, step, or adopted child) and health across 20 countries and five health outcomes.

Methods
Drawing on cross-sectional harmonized data from the family of Health and Retirement Surveys across the United States (HRS, Wave 11), Europe (SHARE, Waves 4 and 5), Mexico (MHAS, Wave 3), and China (CHARLS, Wave 2), we use logistic regression models to estimate the association between childlessness and poor health (poor self-rated health, 1 or more ADL limitations, 1 or more IADL limitations, 1 or more chronic conditions, and depression) in a sample of adults aged 50 and older across 20 countries (N = 109,648).

Results
Our results point to an absence of associations between childlessness and health, and suggest that childlessness may be associated with better (e.g., Mexico, Hungary) or worse health (e.g., Austria, Estonia, Netherlands, Poland) in certain contexts and for certain measures.

Discussion
We discuss these findings in light of the meaning of childlessness, as well as cross-national economic, social, and cultural contexts to provide suggestions for aging policy and future research.
Considerations on the Acceptance of German neologisms from the 1990s
Authors: Klosa-Kückelhaus Annette , Wolfer Sascha 
Published: November 2019

AbstractAre borrowed neologisms accepted more slowly into the German language than German words resulting from the application of wrd formation rules? This study addresses this question by focusing on two possible indicators for the acceptance of neologisms: a) frequency development of 239 German neologisms from the 1990s (loanwords as well as new words resulting from the application of word formation rules) in the German reference corpus DeReKo and b) frequency development in the use of pragmatic markers (‘flags’, namely quotation marks and phrases such as sogenannt ‘so-called’) with these words. In the second part of the article, a psycholinguistic approach to evaluating the (psychological) status of different neologisms and non-words in an experimentally controlled study and plans to carry out interviews in a field test to collect speakers’ opinions on the acceptance of the analysed neologisms are outlined. Finally, implications for the lexicographic treatment of both types of neologisms are discussed.