bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data-Driven Energy Efficiency and Part Geometric Accuracy Modeling and Optimization of Green Fused Filament Fabrication Processes
Authors: Alizadeh Morteza , Esfahani Mehrnaz Noroozi , Tian Wenmeng , Ma Junfeng 
Published: September 2019

Abstract
Nowadays, increasing awareness of environmental protection has evoked the adoption of green technologies in design and manufacturing. As a revolutionizing manufacturing technology that produces components in a layer-by-layer fashion, additive manufacturing (AM) has followed this trend. Among a variety of AM processes, fused filament fabrication (FFF) is one of the most commonly used technologies. However, AM (including FFF) is inherently energy expensive and energy inefficient compared with the conventional manufacturing. Thus, an urgent investigation is needed to reduce the energy consumption for AM production. On the other hand, part geometric accuracy is an important aspect for the quality of additively manufactured components. It is not meaningful to improve AM’s energy consumption performance with compromised part geometric accuracy. Therefore, it is necessary to jointly consider energy consumption as well as part geometric accuracy in the AM process design. This study applies the statistical regression approach to model AM energy consumption and part geometric accuracy. The nondominated sorting genetic algorithm II (NSGA-II) and the technique for order of preference by similarity to ideal solution (TOPSIS) method together are used to locate the compromised optimal solution for AM process parameter settings. The effectiveness of the proposed approach is demonstrated through a case study developed with the FFF process and a specific part design. The results of this study are significant to both AM energy consumption and part geometric accuracy in terms of qualitative and quantitative analyses. Furthermore, the study can potentially guide the future AM sustainability model development and be extended to future AM process improvement.
Effects of Bio-Inspired Micro-Scale Surface Patterns on the Profile Losses in a Linear Cascade
Authors: Liu Qiang , Zhong Shan , Li Lin 
Published: September 2019

Abstract
In this paper, we investigated the effects of herringbone riblets, a type of bio-inspired micro-scale surface patterns, on pressure losses and flow turning angles in a linear cascade over a range of low Reynolds numbers from 0.50 × 105 to 1.50 × 105 and at three different incidence angles. Our experiments showed that despite their micro-scale size, herringbone riblets produced a significant reduction in pressure loss and a substantial increase in flow turning angle except at the low end of the Reynolds numbers tested. In comparison to the baseline case without riblets, the highest reduction in the zone-averaged pressure loss coefficient behind one flow passage was 36.4% which was accompanied by a 4.1 deg increase in the averaged turning angle. The loss reduction was caused by a decrease in γmax at α = −1 deg, a narrower wake zone at α = 9 deg and a mixture of both at α = 4 deg due to the suppression of flow separation on the blade suction surface. It was also noted that such a significant improvement was always accompanied by the appearance of a serrated wake structure in the contours of pressure loss coefficient in which the region with a higher loss reduction occurring directly behind the divergent region of herringbone riblets. The observed improvement in cascade performance was attributed to the secondary flow motion produced by herringbone riblets which energizes the boundary layer. Overall, this work has produced convincing experimental evidence that herringbone riblets could be potentially used as passive flow control devices for reducing flow separation in compressors at low Reynolds numbers.
A New Ultrasonic Testing Method for Residual Strain Measurement With Laser Grating
Authors: Pei Cuixiang , Kou Xing , Liu Tianhao , Chen Zhenmao 
Published: September 2019

Abstract
In this paper, a new and noncontact ultrasonic testing (UT) method using laser grating is proposed for the residual strain measurement. In this method, the laser grating technique is utilized to generate coherent surface waves with a specific wavelength in the narrow frequency band. A numerical method based on the finite element model is established to simulate the coherent surface waves generated by the laser grating in prestrained media to determine the capability and sensitivity of this method. The relationship between the strain and frequency spectrum of the coherent surface wave is studied. Finally, an experiment validation of the laser grating-based UT of residual strain is carried out using specimen with different plastic strains by the tensile test.
An Experimental Evaluation of the Effects of Filtercake in Wellbore Strengthening: Filtercake Rupture Resistance and Fracture Sealing Time
Authors: Yang Mingzheng , Chen Yuanhang 
Published: September 2019

Abstract
Recent research studies have indicated that filtercakes play a role in preventing fracture initiation, blocking pre-existing narrow fractures, and isolating drilling-induced fractures at the initiation stage. The ability of the filtercakes to effectively strengthen the wellbore expectedly depends on its capability in maintaining its integrity and providing the barrier to isolate pressure and fluid transmission between the wellbore and fractures. In this research, a modified permeability apparatus was used to evaluate the quality of drilling fluid filtercakes. A new criterion defined as filtercake rupture resistance is proposed to characterize the filtercake quality regarding its ability to sustain pressure over an open fracture. Experimental tests were conducted to investigate how filtercake thickness and filtercake yield strength affect the rupture resistance. The mechanism of filtercake in sealing the narrow fractures is explored, and it was observed that solid's plugging/bridging plays the vital role in this mechanism. A thicker and stronger filtercake also contributes to a faster establishment of complete fracture seal. The results of this research can be utilized as a reference that guides the optimization of drilling fluid for continuously strengthening the wellbore.
What’s in a Sport Class? The Classification Experiences of Paraswimmers
Authors: Van Dornick Kirsti , Spencer Nancy L.I. 
Published: September 2019

The purpose of this study was to examine the classification experiences (perspectives and reflections) of paraswimmers. Classification provides a structure for parasport, with the goal of reducing the impact of impairment on the outcome of competition. Guided by interpretive description, nine paraswimmers ranging in swimming experience and sport class were interviewed. Reflective notes were also collected. Transcribed interviews were analyzed inductively, followed by a deductive analysis using Nordenfelt’s dignity framework. Three themes represent the findings: access, diversity, and (un)certainty. Despite several positive experiences, paraswimmers also discussed inconsistencies in the process leading them to question competition fairness and classification accuracy. These findings suggest that continued efforts to improve the classification system are required. In addition, paraswimmers and their allies (e.g., coaches) require more information about the classification process to better understand the outcomes and to effectively advocate for their needs.
Reactivity to Accelerometer Measurement of Children With Visual Impairments and Their Family Members
Authors: Zhu Xihe , Haegele Justin A. 
Published: September 2019

The purpose of this study was to examine reactivity to accelerometer measurement in children with visual impairments (VI), their sighted siblings, and their parents. A sample of 66 participants (including 22 children with VI, 22 siblings, and 22 parents) completed a demographic survey and wore triaxial accelerometers for at least 4 consecutive days for 8 hr. An analysis of covariances with repeated measures was conducted, controlling for participant gender. Children with VI had 8.1% less moderate to vigorous physical activity time on Day 1 than Days 2–4 average. Their sighted siblings and parents had 7.8% and 7.1% more moderate to vigorous physical activity time on Day 1 than their Days 2–4 average, respectively. The reactivity percentage for parents and children without VI is consistent with existing literature. However, an inverse reactivity for children with VI was found, which is a unique contribution to the literature and will have implications for researchers using accelerometers for this population.
Not All Play Equipment Is Created Equal: Associations Between Equipment at Home and Children’s Physical Activity
Authors: Moss Katrina M. , Dobson Annette J. , Edwards Kimberley L. , Hesketh Kylie D. , Chang Yung-Ting , Mishra Gita D. 
Published: September 2019

Background: Play equipment at home could be targeted in interventions to increase children’s physical activity (PA), but evidence is mixed, potentially because current methods do not reflect children’s lived experience. This study investigated associations between combinations of equipment and PA. Methods: Data were from the Mothers and their Children’s Health study and the Australian Longitudinal Study on Women’s Health. Mothers (n = 2409) indicated the types of fixed active (eg, trampolines), portable active (eg, bicycles), and electronic (eg, computers) equipment at home, and the number of days children (n = 4092, aged 5–12 y, 51% boys) met PA guidelines. Latent class analysis was used to identify combinations of equipment, and linear regressions were used to investigate associations with PA. Results: Compared with children with high active (fixed and portable) and medium electronic equipment, children with portable active and medium (B = −0.53; 95% confidence interval, −0.72 to −0.34) or high (B = −0.58; 95% confidence interval, −0.83 to −0.33) electronic equipment met the guidelines on fewer days. Children with similar active equipment (but more electronic equipment) met the PA guidelines on fewer days (mean difference = −0.51, SE = 0.14, P = .002). Conclusion: Having the right combination of play equipment at home may be important for children’s PA.
Association of napping with incident cardiovascular events in a prospective cohort study
Authors: Häusler Nadine , Haba-Rubio Jose , Heinzer Raphael , Marques-Vidal Pedro 
Published: September 2019

ObjectiveThere is controversy regarding the effect of napping on cardiovascular disease (CVD), with most studies failing to consider napping frequency. We aimed to assess the relationship of napping frequency and average nap duration with fatal and non-fatal CVD events.Methods3462 subjects of a Swiss population based cohort with no previous history of CVD reported their nap frequency and daily nap duration over a week, and were followed over 5.3 years. Fatal and non-fatal CVD events were adjudicated. Cox regressions were performed to obtain HRs adjusted for major cardiovascular risk factors and excessive daytime sleepiness or obstructive sleep apnoea.Results155 fatal and non-fatal events occurred. We observed a significantly lower risk for subjects napping 1–2 times weekly for developing a CVD event (HR 0.52, 95% CI 0.28 to 0.95) compared with non-napping subjects, in unadjusted as well as adjusted models. The increased HR (1.67, 95% CI 1.10 to 2.55) for subjects napping 6–7 times weekly disappeared in adjusted models (HR 0.89, 95% CI 0.58 to 1.38). Neither obstructive sleep apnoea nor excessive daytime sleepiness modified this lower risk. No association was found between nap duration and CVD events.ConclusionSubjects who nap once or twice per week have a lower risk of incident CVD events, while no association was found for more frequent napping or napping duration. Nap frequency may help explain the discrepant findings regarding the association between napping and CVD events.
Cosmological test on viscous bulk models using Hubble parameter measurements and type Ia supernovae data
Authors: Hernández-Almada A. 
Published: September 2019

Abstract
From a phenomenological point of view, we analyze the dynamics of the Universe at late times by introducing a polynomial and hyperbolic bulk viscosity into the Einstein field equations respectively. We constrain their free parameters using the observational Hubble parameter data and the Type Ia Supernovae dataset to reconstruct the deceleration q and the jerk j parameters within the redshift region $$0<z<2.5$$0<z<2.5. At current epochs, we obtain $$q_0 = -\,0.680^{+0.085}_{-0.102}$$q0=-0.680-0.102+0.085 and $$j_0 = 2.782^{+1.198}_{-0.741}$$j0=2.782-0.741+1.198 for the polynomial model and $$q_0 = -\,0.539^{+0.040}_{-0.038}$$q0=-0.539-0.038+0.040 ($$-\,0.594^{+0.056}_{-0.056}$$-0.594-0.056+0.056) and $$j_0 = 0.297^{+0.051}_{-0.050}$$j0=0.297-0.050+0.051 ($$1.124^{+0.196}_{-0.178}$$1.124-0.178+0.196) for the tanh (cosh) model. Furthermore, we explore the statefinder diagnostic that gives us evident differences with respect to the concordance model (LCDM). According to our results this kind of models is not supported by the data over LCDM.
Semileptonic decays of the scalar tetraquark $$Z_{bc;\overline{u}\overline{d}}^{0}$$
Authors: Sundu H. , Agaev S. S. , Azizi K. 
Published: September 2019

Abstract
We study semileptonic decays of the scalar tetraquark $$Z_{bc;\overline{u} \overline{d}}^{0}$$Zbc;u¯d¯0 to final states $$T_{bs;\overline{u}\overline{d} }^{-}e^{+}\nu _{e}$$Tbs;u¯d¯-e+νe and $$T_{bs;\overline{u}\overline{d}}^{-}\mu ^{+}\nu _{\mu }$$Tbs;u¯d¯-μ+νμ , which run through the weak transitions $$c\rightarrow se^{+}\nu _{e}$$c→se+νe and $$c\rightarrow s\mu ^{+}\nu _{\mu }$$c→sμ+νμ, respectively. To this end, we calculate the mass and coupling of the final-state scalar tetraquark $$T_{bs;\overline{u}\overline{d} }^{-} $$Tbs;u¯d¯- by means of the QCD two-point sum rule method: these spectroscopic parameters are used in our following investigations. In calculations we take into account the vacuum expectation values of the quark, gluon, and mixed operators up to dimension ten. We use also three-point sum rules to evaluate the weak form factors $$G_{i}(q^2)$$Gi(q2) ($$i=1,~2$$i=1,2) that describe these decays. The sum rule predictions for $$G_{i}(q^2)$$Gi(q2) are employed to construct fit functions $$F_{i}(q^2)$$Fi(q2), which allow us to extrapolate the form factors to the whole region of kinematically accessible $$q^2$$q2. These functions are required to get partial widths of the semileptonic decays $$\Gamma \left( Z_{bc}^{0}\rightarrow Te^{+}\nu _{e}\right) $$ΓZbc0→Te+νe and $$\Gamma \left( Z_{bc}^{0}\rightarrow T\mu ^{+}\nu _{\mu }\right) $$ΓZbc0→Tμ+νμ by integrating corresponding differential rates. We analyze also the two-body nonleptonic decays $$Z_{bc;\overline{u}\overline{d}}^{0} \rightarrow T_{bs;\overline{u}\overline{d }}^{-}\pi ^{+}$$Zbc;u¯d¯0→Tbs;u¯d¯-π+ and $$Z_{bc;\overline{u}\overline{d}}^{0} \rightarrow T_{bs;\overline{u }\overline{d}}^{-}K^{+}$$Zbc;u¯d¯0→Tbs;u¯d¯-K+, which are necessary to evaluate the full width of the $$Z_{bc;\overline{u}\overline{d}}^{0}$$Zbc;u¯d¯0. The obtained results for $$\Gamma _{\mathrm {full}}=(3.18\pm 0.39)\times 10^{-11}~{\mathrm {MeV}}$$Γfull=(3.18±0.39)×10-11MeV and mean lifetime $$20.7_{-2.3}^{+2.9}~{\mathrm {ps}}$$20.7-2.3+2.9ps of the tetraquark $$Z_{bc;\overline{u} \overline{d}}^{0}$$Zbc;u¯d¯0 can be used in experimental investigations of this exotic state.
Relaxation dynamics and crystallization study of glass-forming chiral-nematic liquid crystal S,S-2,7-bis(4-pentylphenyl)-9,9-dimethylbutyl 9H-fluorene (5P-Am*FLAm*-P5)
Authors: Jasiurkowska-Delaporte Małgorzata , Rozwadowski Tomasz , Juszyńska-Gała̧zka Ewa , Krawczyk Jan , Dmochowska Ewelina , Kula Przemysław , Massalska-Arodź Maria 
Published: September 2019

Abstract.
The chiral nematic S,S-2,7-bis(4-pentylphenyl)-9,9-dimethylbutyl9H-fluorene (5P-Am*FLAm*-P5) liquid crystal shows a complex phase diagram strongly dependent on thermal treatment as identified by Polarizing Optical Microscopy (POM) and differential scanning calorimeter (DSC). The molecular dynamics in various thermodynamics states was studied by means of broadband dielectric spectroscopy (BDS). The vitrification of a chiral nematic phase (N*) is manifested by a Vogel-Fulcher-Tammann (VFT)-type temperature dependence of structural relaxation time ($\tau_{\alpha}$τα). Three dielectric relaxation processes exhibiting Arrhenius-like thermal activation were found in conformationally disordered (condis) Cr1 and Cr2 structures. The isothermal cold crystallization process of Cr2 occurs in the metastable N* phase; however, in the non-isothermal experiments, the Cr2 phase is formed in the isotropic phase obtained on heating the metastable N* phase. The findings for the isothermal process were compared with those regarding non-isothermal crystallization.

Graphical abstract
Machining and Characterization of Micro-Channels Generated on Phosphor Bronze Using μ-EDM
Authors: Raju Leera , Hiremath Somashekhar S. 
Published: September 2019

Micro-Electro Discharge Machining ([Formula: see text]-EDM) is one of the nonconventional micro-machining processes in which electrical discharges are produced between the micro-sized electrodes — tool and workpiece immersed in dielectric fluid. The electrical discharges thus produced remove the workpiece material through melting and vaporization process and results in the creation of micro-craters. This paper focuses on machining of micro-channels on copper alloy — phosphor bronze plate using [Formula: see text]-EDM. Various micro-channels have been machined on phosphor bronze with input parameters: voltage, capacitance and pulse on-time varied at four levels. The experimental layout plans were designed with robust design technique — Taguchi-based L[Formula: see text] orthogonal array and the process parameters were optimized using optimization technique — Grey Relational Analysis (GRA). The dimensional aspects — depth, width, profile and surface roughness of machined channels were selected as output responses. The experimental results show that the parameters have individual and combined effect on responses. Analysis of Variance (ANOVA) technique has been used to explore the effect of parameters on responses. Detailed surface morphology of the machined features has also been analyzed using scanning electron microscope (SEM) and noncontact optical profiler images. As an extension of machining channels, Y-shaped channel has been machined on copper alloy which can be used for micro-fluidic applications.
Recruit Until It Fails
Authors: Sugrim Shridatt , Liu Can , Lindqvist Janne 
Published: September 2019

Distinguishing identities is useful for several applications such as automated grocery or personalized recommendations. Unfortunately, several recent proposals for identification systems are evaluated using poor recruitment practices. We discovered that 23 out of 30 surveyed systems used datasets with 20 participants or less. Those studies achieved an average classification accuracy of 93%. We show that the classifier performance is misleading when the participant count is small. This is because the finite precision of measurements creates upper limits on the number of users that can be distinguished.
To demonstrate why classifier performance is misleading, we used publicly available datasets. The data was collected from human subjects. We created five systems with at least 20 participants each. In three cases we achieved accuracies greater than 90% by merely applying readily available machine learning software packages, often with default parameters. For datasets where we had sufficient participants, we evaluated how the performance degrades as the number of participants increases. One of the systems built suffered a drop in accuracy that was over 35% as the participant count increased from 20 to 250. We argue that data from small participant count datasets do not adequately explore variations. Systems trained on such limited data are likely to incorrectly identify users when the user base increases beyond what was tested. We conclude by explaining generalizable reasons for this issue and provide insights on how to conduct more robust system analysis and design.
Cartas para Nelson
Authors: Badini Giulia Bortoliero Coli 
Published: September 2019

Joel Rufino dos Santos escreveu uma série de cartas destinadas ao seu filho Nelson enquanto esteve encarcerado pelo regime militar brasileiro entre 1972 e 1974. Foi de dentro do presídio do Hipódromo que Joel - pai, carioca, historiador, negro e militante - buscou através das correspondências, repletas de sentimentos, cores, lembranças, sonhos e histórias, manter contato com seu filho e estar presente na vida da criança, numa tentativa de superar a distância e a ausência impostas. Esta pesquisa teve como objetivo analisar as correspondências enquanto importantes registros de uma memória acerca da ditadura militar e mecanismos de resistência ao regime. Pôde-se então concluir a consolidação tanto de uma memória individual quanto coletiva, bem como da resistência através de mecanismos que garantiram a sobrevivência do preso político e da rede de sociabilidade criada dentro do cárcere. Possibilitou também a apreensão acerca do sistema repressivo consolidado pelo regime militar brasileiro, pensando especificamente na repressão à intelectualidade e aos movimentos negros. Para a compreensão das correspondências, publicadas no livro Quando eu voltei, tive uma surpresa (SANTOS, 2000), foi fundamental a leitura e análise de documentos auxiliares, tais como: entrevista concedia ao Instituto de Estudos Brasileiro de Análises Sociais e Econômicas (SANTOS, 2010), livros da coleção de livros didáticos História Nova do Brasil, volume 1 (SANTOS, 1965) e volume 4 (SANTOS, 1964), os processos de prisão e soltura de Joel Rufino dos Santos – disponíveis para acesso no Arquivo do Estado de São Paulo, e o livro Zumbi (SANTOS, 1987).
Shades of Green: Mapping the Parameters of the GATT Article III:8(a) Government Procurement Derogation in the Renewable Energy Transition
Authors: Fang Mandy Meng 
Published: September 2019

Abstract
The increasingly pervasive use of trade-related supportive measures in the renewable energy sector has created tensions with World Trade Organization (WTO) obligations. This tension has led to a number of disputes, and in so doing became a testing ground for the compatibility between the trade regime and the climate regime. This article adds to the existing literature by focusing on one of the less discussed, but extremely important, WTO provisions relevant in assessing the legality of renewable energy measures: GATT Article III:8(a). Dormant for more than six decades, Article III:8(a) became a focal point of both the Canada – Renewable Energy and India – Solar Cells disputes. The Appellate Body in both disputes interpreted the so-called government ‘procurement derogation’ narrowly and in so doing limited the scope of the provision. This article argues that while the ultimate decision reached by the Appellate Body was correct, its methodological approach was flawed and could render the provision inapplicable even in scenarios where the measures are unquestionably government procurement. Instead, this article argues that the methodological approach used by the Panel in Canada – Renewable Energy is preferable and more in line with the textual meaning of Article III:8(a).