bluuebunny/crossref_metadata_2025 huggingface dataset:
Decoupling local mechanics from large-scale structure in modular metamaterials
Authors: Yang Nan , Silverberg Jesse L.
Published: March 2017

Significance

The forward-design approach to mechanical metamaterials determines a structure’s properties after it is designed. In contrast, the inverse-design approach specifies parameter domains then optimizes a cost function to achieve a desired property. The former approach guarantees a structure will exist but lacks the ability to prescribe function. The latter approach has prescribed function, but existence is not guaranteed. Here, we trivialize these design challenges for metamaterials by decoupling local mechanical properties from the bulk structure, allowing both to be specified independently. This work introduces a design strategy that substantially advances the capacity to engineer mechanical metamaterials by specifically using modular units with more free design parameters than constraints. The fundamental strategy is explicitly demonstrated with an origami- and kirigami-inspired structure.
Structural basis for specific ligation of the peroxisome proliferator-activated receptor δ
Authors: Wu Chyuan-Chuan , Baiga Thomas J. , Downes Michael , La Clair James J. , Atkins Annette R. , Richard Stephane B. , Fan Weiwei , Stockley-Noel Theresa A. , Bowman Marianne E. , Noel Joseph P. , Evans Ronald M.
Published: March 2017

Significance

Clinical treatments for metabolic diseases rely on agents with high selectivity to specific targets often within a class of structurally and functionally related proteins. In this paper, we uncover physical and chemical features governing selective small-molecule binding to peroxisome proliferator-activated receptor (PPAR) δ concomitant with distinct conformational changes in the receptor, key to therapeutic modulation of lipid catabolism, transport, and storage. These studies reveal the subtle interplay between ligand configuration and chemistry coupled to modulation of PPARδ structural dynamics. This set of structure–activity relationships (SARs) guide synthetic ligand designs necessary to refine therapeutic leads for temporally and spatially regulating PPARδ during the course of metabolic disease onset and progression.
p97/VCP promotes degradation of CRBN substrate glutamine synthetase and neosubstrates
Authors: Nguyen Thang Van , Li Jing , Lu Chin-Chun (Jean) , Mamrosh Jennifer L. , Lu Gang , Cathers Brian E. , Deshaies Raymond J.
Published: March 2017

Significance

We have recently reported that glutamine synthetase (GS) is negatively regulated by glutamine through a feedback loop involving the E3 ubiquitin ligase CRL4CRBN. However, the molecular events that take place at each step of the pathway are not well understood. Here, we show that valosin-containing protein (VCP)/p97, is required for GS degradation. It acts downstream of CRL4CRBN. p97 extracts ubiquitylated GS subunits from the decamer so that they can be degraded by the proteasome. Interestingly, p97 is also required for immunomodulatory drug-induced degradation of all four known CRL4CRBNneosubstrates, including Ikaros family zinc finger proteins 1 (IKZF1) and 3 (IKZF3), casein kinase 1α (CK1α), and the translation termination factor GSPT1, which accounts for antitumor activity of these drugs. Our findings could have important implications for patient responsiveness to cancer therapy with immunomodulatory drugs.
‘English a foreign tongue’
Authors: Sebba Mark
Published: March 2017

The 2011 UK Census was the first ever to ask a question about language in England. The period during which the census was planned coincided with a period of intense politicisation of the language issue, which had previously not been a major point of controversy.

The census results showed that 98.3% of the adult population either spoke English as their ‘main language’, or could speak it well or very well. In 4% of households no adults spoke English as a main language. These statistics produced an intense media reaction focussed on the number of people who supposedly could not speak English, with some high-level misunderstandings about what the figures meant.

This paper discusses the pervasiveness in the census process of ideologies about language, and how an apparently honest attempt to collect information for service providers was used to justify anti-immigration discourse and the reduction of services for non-speakers of English.
Blood, Soil, and Tears
Authors: Santa Ana Otto , Waitkuweit Kevin Hans , Hernandez Mishna Erana
Published: March 2017

The Fourteenth Amendment to the US Constitution grants citizenship to every child born on US soil. While most Americans think this 150 year old formulation is permanent, it is actually open to change. We explore the legal debate over the current formulation of US citizenship. Using the research design of the exemplar case study, we undertake a conceptual metaphor-based critical discourse analysis of three contending contemporary legal stances regarding US citizenship. In the light of four current court cases, some legal theorists argue that the formulation is both undemocratic and inadequate, and should be amended to address 21st century national concerns. Others argue to retain the current formulation in spite of these concerns. Our study reveals that the rival stances are argued in terms of irreconcilable conceptual metaphors, and each legal stance in itself is deficient to address these current concerns.
Friction spot welding of dissimilar 6063/5083 aluminium alloys
Authors: Li Zhengwei , Xu Zhiwu , Zhang Liguo , Yan Zhongjie
Published: March 2017

In this work, friction spot welding (FSpW) was used to weld dissimilar 6063/5083 aluminium alloys, and the effects of the sleeve plunging speed on joint microstructures and the lap shear properties were discussed. Results showed that the keyhole can be eliminated using FSpW. Bending hooks changed to a flat morphology when the plunging speed was increased. Excellent bonding was formed at the lap interface in the sleeve-affected zone. As the sleeve plunging speed was increased from 40 to 110 mm min−1, the lap shear failure loads for the joints first increased and then decreased. A maximum failure load of 8017 N was attained when using a sleeve plunging speed of 80 mm min−1. All joints fractured at the lap interface.
Membrane remodeling during embryonic abscission in Caenorhabditis elegans
Authors: König Julia , Frankel E.B. , Audhya Anjon , Müller-Reichert Thomas
Published: March 2017

Abscission is the final step of cytokinesis and results in the physical separation of two daughter cells. In this study, we conducted a time-resolved series of electron tomographic reconstructions to define the steps required for the first embryonic abscission in Caenorhabditis elegans. Our findings indicate that membrane scission occurs on both sides of the midbody ring with random order and that completion of the scission process requires actomyosin-driven membrane remodeling, but not microtubules. Moreover, continuous membrane removal predominates during the late stages of cytokinesis, mediated by both dynamin and the ESCRT (endosomal sorting complex required for transport) machinery. Surprisingly, in the absence of ESCRT function in C. elegans, cytokinetic abscission is delayed but can be completed, suggesting the existence of parallel membrane-reorganizing pathways that cooperatively enable the efficient severing of cytoplasmic connections between dividing daughter cells.
Explanation = Unification? A New Criticism of Friedman’s Theory and a Reply to an Old One
Authors: Roche William , Sober Elliott
Published: March 2017

According to Michael Friedman’s theory of explanation, a lawXexplains lawsY1,Y2, …,Ynprecisely whenXunifies theY’s, where unification is understood in terms of reducing the number of independently acceptable laws. Philip Kitcher criticized Friedman’s theory but did not analyze the concept of independent acceptability. Here we show that Kitcher’s objection can be met by modifying an element in Friedman’s account. In addition, we argue that there are serious objections to the use that Friedman makes of the concept of independent acceptability.
Interactive Causes: Revising the Markov Condition
Authors: Schurz Gerhard
Published: March 2017

This article suggests a revision of the theory of causal nets (TCN). In section 1 we introduce an axiomatization of TCN based on a realistic understanding. It is shown that the causal Markov condition entails three independent principles. In section 2 we analyze indeterministic decay as the major counterexample to one of these principles: screening off by common causes (SCC). We call SCC-violating common causes interactive causes. In section 3 we develop a revised version of TCN, called TCN*, which accounts for interactive causes. It is shown that there are interactive causal models that admit of no faithful noninteractive reconstruction.
A Naturalist’s Guide to Objective Chance
Authors: Emery Nina
Published: March 2017

I argue that there are such things as nomological probabilities—probabilities that play a certain explanatory role with respect to stable, long-run relative frequencies. Indeed, I argue, we should be willing to accept nomological probabilities even if they turn out to be metaphysically weird or even wholly sui generis entities. I then give an example of one way in which this argument should shape future work on the metaphysics of chance by describing a challenge to a common group of analyses of objective probability—Humean analyses—understood as analyses of nomological probability.
A Generalized Selected Effects Theory of Function
Authors: Garson Justin
Published: March 2017

I present and defend the generalized selected effects (GSE) theory of function. According to GSE, the function of a trait consists in the activity that contributed to its bearer’s differential reproduction, or differential retention, within a population. Unlike the traditional selected effects (SE) theory, it does not require that the functional trait helped its bearer reproduce; differential retention is enough. Although the core theory has been presented previously, I go significantly beyond those presentations by providing a new argument for GSE and defending it from a recent objection. I also sketch its implications for teleosemantics and philosophy of medicine.
Association Between Cardiovascular Health and Endothelial Function With Future Erectile Dysfunction: The Multi-Ethnic Study of Atherosclerosis
Authors: Lane-Cordova Abbi D. , Kershaw Kiarri , Liu Kiang , Herrington David , Lloyd-Jones Donald M.
Published: March 2017

BACKGROUND

The association of Cardiovascular Health (CVH; defined by the American Heart Association by assigning points for health-related behavioral and clinical factors) with endothelial and erectile dysfunction has not been reported, although endothelial and erectile dysfunction have been associated with components of CVH.

METHODS

Data were collected in 1,136 men in the Multi-Ethnic Study of Atherosclerosis at baseline and erectile dysfunction status (measured by survey or medication use) at exam 5. CVH was determined with 7 health metrics. Endothelial function was measured with brachial artery flow-mediated dilation (FMD). Poisson regression was used to determine associations between CVH and erectile dysfunction across categories of CVH (low, moderate, and high).

RESULTS

Age and proportion of Black or Latino participants decreased while proportion of Chinese-American participants increased with higher CVH category. FMD was higher in men without erectile dysfunction and higher in men with high vs. low CVH. Erectile dysfunction prevalence was lower with better CVH; 58% in men with low CVH, 41% with moderate CVH, and 33% with high CVH (P < 0.001). CVH was associated with erectile dysfunction; prevalence ratio = 0.75 (95% confidence interval (CI) = 0.66, 0.84) with moderate CVH and 0.68 (95% CI = 0.49, 0.94) with high CVH (vs. men with low CVH) and 0.93 (95% CI = 0.91, 0.96) for every 1-point higher CVH score in a fully adjusted model, including FMD, age, education, depression score, use of antidepressant or beta-blocker medications, chronic disease, heavy drinking, and race.

CONCLUSION

CVH is associated with future erectile dysfunction, even after adjustment for baseline FMD. Maintaining high CVH may improve quality of life for men.
Population Structure and Genetic Diversity of Phytophthora nicotianae from Tobacco in Georgia
Authors: Li Yonggang , Harris-Shultz Karen , Wang Hongliang , Wadl Phillip A. , Ji Pingsheng
Published: March 2017

Black shank, caused by Phytophthora nicotianae, occurs worldwide and is responsible for significant yield loss in tobacco production in Georgia. Management of the disease has primarily relied on utilization of tobacco cultivars with resistance to race 0 of the pathogen and application of the fungicide mefenoxam. Races of P. nicotianae currently prevalent in tobacco production in Georgia, their sensitivity to mefenoxam, and genetic diversity of the pathogen are largely unknown. To determine population structure and genetic diversity of the pathogen, simple sequence repeat (SSR) markers were used. Three races of P. nicotianae (races 0, 1, and 3) were isolated from infected tobacco plants, with race 3 identified in Georgia for the first time. The majority of isolates were identified as A2 mating type and all isolates were sensitive or intermediately sensitive to mefenoxam at 1 or 10 μg/ml, with effective concentration of mefenoxam for 50% mycelial growth reduction values ranging from <0.01 to 0.12 μg/ml. Bayesian and unweighted pair group method with arithmetic means analyses of 59 isolates using SSR markers grouped the isolates in two major groups. Group I contained 20 isolates, of which 19 isolates were collected from Berrien County. Group II contained 39 isolates collected from Bacon, Cook, Tift, and Toombs Counties as well as one sample from Berrien County. Genetic diversity of the isolates was associated with geographical location of collection, and isolates in group I were primarily (75%) race 1, whereas isolates in group II were primarily (69%) race 0. The presence of a single pathogen mating type at most of the locations implies low probability of sexual recombination that may have contributed to the low genetic diversity at a particular geographical location. Sensitivity of the isolates to mefenoxam indicates that the fungicide remains to be a potent tool for growers to combat the disease. Information generated in the study advances our knowledge about diversity and population structure of P. nicotianae, which facilitates development and implementation of effective disease management programs.
Sagittal plane parameters in growing rod patients following final fusion
Authors: Murphy Robert F. , Emans John B. , Troy Michael , Miller Patricia E. , Hresko Michael T. , Karlin Lawrence I. , Hedequist Daniel J. , Glotzbecker Michael P.
Published: March 2017

Almost half of growing rod (GR) patients that undergo final fusion (FF) have an extension of instrumented levels. The purpose of this study was to review sagittal plane radiographic parameters of patients with distal extension of instrumented levels at FF to those whose levels remained the same. Radiographs were assessed preoperatively, after GR insertion/first lengthening, following GR treatment before FFs, and after FF. Measurements included sagittal balance, lumbar lordosis, thoracic kyphosis, and distal junction angle (DJA). Twenty-one patients were included. There was no change in sagittal balance. There was a significant decrease in lordosis and kyphosis following initial GR implantation. Kyphosis and lordosis increased during the GR period, but remained unchanged at time of FF. DJA increased 8° on average. Seven patients had distal extension of instrumented levels at time of FF (average 2 levels, range: 1–4). Indication for distal extension was sagittal plane decompensation in four cases. When comparing patients who had distal extension at the time of FF to those whose levels remained the same, there was no difference in the change in sagittal balance, lordosis, or kyphosis. Final DJA was significantly smaller in those patients with distal extension. Most GR patients that undergo FF demonstrate acceptable correction of sagittal plane radiographic parameters. A small cohort of patients requires distal extension at FF due to sagittal plane decompensation. Level of Evidence: Level IV, Therapeutic.
Treatment of proximal humerus fractures in children with a modified palm tree technique
Authors: Ali Ayman M. , Fawzy Sallam I. , Moaty Medhat , Abelaziz Mohamed
Published: March 2017

Although most pediatric proximal humeral fractures can be successfully treated conservatively with satisfactory results, many operative techniques have been described for the treatment of displaced proximal humeral fractures. The aim of this study is to evaluate the efficacy of percutaneous fixation using a modified palm tree technique for proximal humerus fractures in children. Between March 2011 and May 2013, the modified palm tree technique was used for the management of 30 children (20 boys and 10 girls) with displaced proximal humeral fractures. The average age of the patients was 11.5 years (age range from 8 to 15 years). They were evaluated clinically by the Constant–Murley score and by radiological analysis. The average follow-up duration was 18 months. The average time of fracture union was 6 weeks (range from 4 to 8 weeks). The average Constant score of the patients was 92 (range from 87 to 95), with excellent results in 27 (90%) cases, good results in three (10%) cases, and no fair or poor results (0%). The reported complications were superficial pin-tract infection in five cases, treated by daily dressing and local antibiotics, and malunion with a varus deformity in two cases (about 15°), with no recorded cases with deep infection. None of the cases required open reduction. No cases were complicated by avascular necrosis of the head humerus or loss of fixation. Kirschner wires were removed after an average period of 7 weeks. The modified palm tree technique represents an efficient method for the treatment of proximal humerus fractures in children. It produces a good grip in both the proximal and distal fragments. It allows for early joint movements.
A Newborn With Familial Hemophagocytic Lymphohistiocytosis Complicated With Transfusion Associated Graft Versus Host Disease
Authors: Ozdemir Ahmet , Gunes Tamer , Chiang Samuel C.C. , Unal Ekrem
Published: March 2017

Hemophagocytic lymphohistiocytosis (HLH) is characterized by activation of cytotoxic T and natural killer (NK) cells, and macrophages related to a spectrum of hyperinflammatory disorders. The clinical findings mainly include high fever, cytopenia, splenomegaly, phagocytosis, and proliferation of histiocytes in lymphoreticular tissue. To the best of our knowledge, transfusion-associated graft versus host disease (TA-GVHD) in a 13-day old male newborn with HLH is being reported first time in the literature. The aim of this report was to emphasize the importance of blood products irradiation in the prevention of the development of graft versus host disease especially among high-risk subjects such as newborns with HLH.
Rapid Sequentialin SituMultiplexing With DNA-Exchange-Imaging
Authors: Wang Yu , Woehrstein Johannes B. , Donoghue Noah , Dai Mingjie , Avendaño Maier S. , Schackmann Ron C.J. , Zoeller Jason J. , Wang Shan Shan H. , Tillberg Paul W. , Park Demian , Lapan Sylvain W. , Boyden Edward S. , Brugge Joan S. , Kaeser Pascal S. , Church George M. , Agasti Sarit S. , Jungmann Ralf , Yin Peng
Published: March 2017

To decipher the molecular mechanism of biological function, it is critical to map the molecular composition of individual cells in the context of their biological environmentin situ. Immunofluorescence (IF) provides specific labeling for molecular profiling. However, conventional IF methods have finite multiplexing capabilities due to spectral overlap of the fluorophores. Various sequential imaging methods have been developed to circumvent this spectral limit, but are not widely adopted due to the common limitation of requiring multi-rounds of slow (typically over 2 hours at room temperature to overnight at 4 °C in practice) immunostaining. DNA-Exchange-Imaging is a practical platform for rapidin situspectrally-unlimited multiplexing. This technique overcomes speed restrictions by allowing for single-step immunostaining with DNA-barcoded antibodies, followed by rapid (less than 10 minutes) buffer exchange of fluorophore-bearing DNA imager strands. By eliminating the need for multiple rounds of immunostaining, DEI enables rapid spectrally unlimited sequential imaging. The programmability of DNA-Exchange-Imaging allows us to further adapt it to diverse microscopy platforms (with Exchange-Confocal, Exchange-SIM, Exchange-STED, and Exchange-PAINT demonstrated here), achieving highly multiplexedin situprotein visualization in diverse samples (including neuronal and tumor cells as well as fresh-frozen or paraffin-embedded tissue sections) and at multiple desired resolution scales (from ~300 nm down to sub-20-nm). Validation highlights include 8-target imaging using single-channel Exchange-Confocal in tens of micron thick retina tissue sections in 2-3 hours (as compared to days required in principle by previous methods using comparable equipment), and 8-target super-resolution imaging with ~20 nm resolution using Exchange-PAINT in primary neurons. These results collectively suggest DNA-Exchange as a versatile, practical platform for rapid, highly multiplexedin situimaging, potentially enabling new applications ranging from basic science, to drug discovery, and to clinical pathology.
A new organotypic model of synaptic competition reveals activity-dependent localization of C1q
Authors: Koyama Ryuta , Wu Yuwen , Bialas Allison R. , Thompson Andrew , Welsh Christina A. , Frouin Arnaud , Chen Chinfei , Stevens Beth
Published: March 2017

Immature neural circuits undergo synaptic refinement, in which activity-dependent competition between synapses results in pruning of inappropriate connections and maintenance of appropriate ones. A longstanding question is how neuronal activity eliminates specific synapses based on their strength. The technical challenges ofin vivostudies have made it difficult to identify a molecular link between decreased activity and synapse elimination. We developed an organotypic coculture model of the mouse retinogeniculate system that facilitates real-time imaging and elucidation of molecular mechanisms underlying the removal of less active synapses during synaptic competition. Using this model we show for the first time that complement component C1q is necessary for activity-dependent synaptic competition and preferentially localizes to less active, competing presynaptic inputs. In conjunction with classicin vivoandex vivomodels, this coculture model is a new tool to reveal molecular pathways underlying CNS circuit refinement.
Development of picosecond time-resolved X-ray absorption spectroscopy by high-repetition-rate laser pump/X-ray probe at Beijing Synchrotron Radiation Facility
Authors: Wang Hao , Yu Can , Wei Xu , Gao Zhenhua , Xu Guang-Lei , Sun Da-Rui , Li Zhenjie , Zhou Yangfan , Li Qiu-Ju , Zhang Bing-Bing , Xu Jin-Qiang , Wang Lin , Zhang Yan , Tan Ying-Lei , Tao Ye
Published: March 2017

A new setup and commissioning of transient X-ray absorption spectroscopy are described, based on the high-repetition-rate laser pump/X-ray probe method, at the 1W2B wiggler beamline at the Beijing Synchrotron Radiation Facility. A high-repetition-rate and high-power laser is incorporated into the setup with in-house-built avalanche photodiodes as detectors. A simple acquisition scheme was applied to obtain laser-on and laser-off signals simultaneously. The capability of picosecond transient X-ray absorption spectroscopy measurement was demonstrated for a photo-induced spin-crossover iron complex in 6 mM solution with 155 kHz repetition rate.
1-{[3-(Thiophen-2-yl)-4,5-dihydro-1,2-oxazol-5-yl]methyl}-2,3-dihydro-1H-indole-2,3-dione
Authors: Rayni Ibtissam , El Bakri Youness , Sebhaoui Jihad , El Bourakadi Khadija , Essassi El Mokhtar , Mague Joel T.
Published: March 2017

In the title compound, C16H12N2O3S, the indoline and thiophene rings are inclined to one another by 2.01 (2)°. The isoxazole ring adopts an envelope conformation, with the methine C atom as the flap, and its mean plane is inclined to the thiophene and indoline ring mean planes by 19.78 (14) and 20.83 (12)°, respectively. In the crystal, molecules are linked by C—H...O hydrogen bonds involving the same acceptor atom, forming chains propagating along [010]. The chains are linked by further C—H...O hydrogen bonds, forming slabs parallel to the (-103) plane. The slabs are linked by offset π–π interactions [intercentroid distance = 3.792 (1) Å], forming a three-dimensional supramolecular structure.
Waveform relaxation–Newton method to determine steady state of an electromagnetic structure
Authors: Caron Guillaume , Henneron Thomas , Piriou Francis , Mipo Jean-Claude
Published: March 2017

Purpose

The purpose of this study is to determine the steady state of an electromagnetic structure using the finite element method (FEM) without calculation of the transient state. The proposed method permits to reduce the computation time if the transient state is important.

Design/methodology/approach

In the case of coupling magnetic and electric circuit equations to obtain the steady state with periodic conditions, an approach can be to discretise the time with periodic conditions and to solve the equation system. Unfortunately, the computation time can be prohibitive. In this paper, the authors proposed to use the waveform relaxation method associated with the Newton method to accelerate the convergence.

Findings

The obtained results show that the proposed approach is efficient if the transient state is important. On the contrary, if the transient state is very low, it is preferable to use the classical approach, namely, the time-stepping FEM.

Research limitations/implications

The main limitation of the proposed approach is the necessity to evaluate or to know the time constant and consequently the duration of the transient state. Moreover the method requires some important memory resources.

Practical/implications

In the context of the use of the time-stepping FEM, one of the problems is the computation time which can be important to obtain the steady state. The proposed method permits avoidance of this difficulty and directly gives the steady state.

Social/implications

The proposed approach will permit to model and study the electromagnetic systems in the steady state, and particularly the transformers. Because of the gain in computing time, the use of optimisation techniques will be facilitated.

Originality/value

The novelty of this study is the proposal of the waveform relaxation–Newton method to directly obtain the steady state when applied to the three-phase transformer.
Eddy current sensor simulation
Authors: Bulic Neven , Šušnjic Livio
Published: March 2017

Purpose

This paper aims to present a simulation concept and an experimental verification of a novel sensor design for the shaft position measurement based on the eddy current principle and the phase-shift measurement. The simulation method for the sensor characteristic determination is presented. Possible application of a new sensor type is theoretically presented, verified in simulation and compared with experimental results.

Design/methodology/approach

Sensor is based on the injection-locking phenomenon between coupled oscillators. Only one sensor per axis is used for position measurement. A pair of the sensing and reference oscillators in the sensor is electrically coupled via the coupling resistor. A change in the inductance for the eddy current sensor is simulated in the finite element method (FEM) software Flux and behavior of the sensor circuit is simulated in the SPICE simulator software LTSpice program. Finally, the simulation results are compared with the measurements conducted on the laboratory test rig.

Findings

A novelty in this approach is the usage of only one sensor per axis compared to the well-known differential measurement of the position that uses the opposite pair of the sensing oscillators in the same axis. A methodology for the sensor characteristic determination is presented and experimentally verified.

Originality/value

A new variation of a coupled-oscillator eddy current sensor design is introduced. A simulation approach for the characteristic determination of the sensors based on the weakly coupled oscillators and the injection-locking mechanism is presented.
Comparative analysis of the three- and six-phase fractional slot concentrated winding permanent magnet machines
Authors: Jedryczka Cezary
Published: March 2017

Purpose

The purpose of this paper is to analyse and compare the functional parameters of three- and six-phase permanent magnet synchronous motors (PMSM) with fractional-slot concentrated windings (FSCW).

Design/methodology/approach

The investigations are focused on the comparison of the distortions of back electromotive force (emf) and magnetomotive force (mmf) waveforms, as well as torque ripples, radial force spatial harmonics and motor performance studies. The finite element models of the test machine and a personally developed computer code have been used to calculate motor characteristics and analyse and synthesise multiphase winding layouts, respectively.

Findings

Compared with the traditional three-phase PMSM designs, the proposed six-phase machines are characterized by a significantly lower content of sub-harmonics in mmf waveform distribution. Moreover, the investigated six-phase machines exhibited a higher average value of electromagnetic torque, significantly lower torque ripples and a reduced value of low-order harmonics of the radial component of the electromagnetic force in the air-gap of the machine.

Originality/value

The analyses presented in this paper show that six-phase PMSM with FSCWs are advantageous to their counterpart three-phase machines. Specifically, they are more suited to working with multiple drives supplying a segmented winding system while simultaneously offering higher performance. This suitability to the use of a multi-drive supply for one motor offers flexibility and cost reduction while increasing the fault tolerance of a power train system.
A robust finite volume method for three-dimensional filling simulation of plastic injection molding
Authors: Liang Junjie , Luo Wan , Huang Zhigao , Zhou Huamin , Zhang Yun , Zhang Yi , Fu Yang
Published: March 2017

Purpose

The purpose of this paper is to develop a finite volume approach for the simulation of three-dimensional two-phase (polymer melt and air) flow in plastic injection molding which is capable of robustly handling the mesh non-orthogonality and the discontinuities in fluid properties.

Design/methodology/approach

The presented numerical method is based on a cell-centered unstructured finite volume discretization with a volume-of-fluid technique for interface capturing. The over-relaxed approach is adopted to handle the non-orthogonality involved in the discretization of the face normal derivatives to enhance the robustness of the solutions on non-orthogonal meshes. A novel interpolation method for the face pressure is derived to address the numerical stability issues resulting from the density and viscosity discontinuities at the melt–air interface. Various test cases are conducted to evaluate the proposed method.

Findings

The presented method was shown to be satisfactorily accurate by comparing simulations with analytical and experimental results. Besides, the effectiveness of the proposed face pressure interpolation method was verified by numerical examples of a two-phase flow problem with various density and viscosity ratios. The proposed method was also successfully applied to the simulation of a practical filling case.

Originality/value

The proposed finite volume approach is more tolerant of non-orthogonal meshes and the discontinuities in fluid properties for two-phase flow simulation; therefore, it is valuable for engineers in engineering computations.
MHD nanofluid flow through a deformable asymmetric porous channel
Authors: Ahmed Naveed , Khan Umar , Mohyud-din Syed Tauseef
Published: March 2017

Purpose

The aim of this manuscript is to study the flow of a nanofluid through a porous channel under the influence of a transverse magnetic field. Permeability of the walls is considered to be different, which results in an asymmetric nature of the flow. The height of the channel is variable, and it dilates or squeezes at a uniform rate.

Design/methodology/approach

A numerical solution (Runge–Kutta–Fehlberg) has been obtained after reducing the governing equations to a system of nonlinear ordinary differential equations using some suitable similarity transforms, both in time and space.

Findings

An increase in absolute values of the permeability parameter results in an enhanced mass transfer rate at both the walls, while the rate of heat transfer also increases at the lower wall. Few graphs are also dedicated to see the behavior of Nusselt and Sherwood numbers following the variations in flow parameters.

Originality/value

A pictorial description of the flow and effects of emerging parameters on the temperature and nanoparticle concentration profiles is presented to analyze the flow behavior. It is established that the asymmetry of the channel affects the flow quite significantly.
Double position sensitive detectors (PSDs) based measurement system of trajectory tracking of a moving target
Authors: Lu Xiaohong , Jia Zhenyuan , Hu Xiaochen , Wang Wentao
Published: March 2017

Purpose

The purpose of this paper is to achieve the trajectory tracking measurement of a moving target based on double position sensitive detectors (PSDs).

Design/methodology/approach

In this paper, first, a double PSD-based measurement system including hardware system and software system is built up. Then, the working principle is studied to calculate parameters, and calibration experience is conducted. Finally, this double PSD-based measurement system is used to test angular displacement and axial displacement on the tool magazine and automatic tool changer.

Findings

In the experiment, the maximum position error of a space point based on double PSD measurement system is 0.8566 mm, and the average error is 0.4716 mm. These results show that the built double PSD-based measurement system of trajectory tracking of a moving target is reasonable.

Originality/value

Combining the characteristics of the PSD and principles of binocular visual measurement, a non-contact three-dimensional measuring system based on double PSDs is developed. The designed double-based measurement system is quite suitable for measurement of a fast-changing illuminant or in the case that the tracking accuracy is not tight.
Boundary layer flow of a dusty fluid over a permeable shrinking surface
Authors: Hamid Rohana Abdul , Nazar Roslinda , Pop Ioan
Published: March 2017

Purpose

The purpose of this paper is to numerically study the boundary layer problem for the case of two-dimensional flow of dusty fluid over a shrinking surface in the presence of the fluid suction at the surface.

Design/methodology/approach

The governing equations of the problem are reduced to the system of ordinary differential equations using the similarity transformation and then solved using the bvp4c method in the Matlab software.

Findings

The effects of the drag coefficient parameter L, the fluid–particle interaction parameter δ, the suction parameter s and the particle loading parameter ω on the flow of the permeable shrinking sheet are investigated. It is found that the aforementioned parameters have different effects in the shrinking sheet flow. This study has also succeeded in discovering the second solution, and through the stability analysis, it is suggested that the solution is unstable and not physically realizable in practice.

Practical implications

The current findings add to a growing body of literature on the boundary layer problem in the dusty fluid. The dusty fluid is significant in various practical applications such as in the transporting suspended powdered materials through pipes, propulsion and combustion in rockets, the flow of blood in arteries, wastewater treatment and as corrosive particles in engine oil flow.

Originality/value

Even though the dusty fluid problem has been extensively studied in the flow of the stretching sheet, limited findings can be found over a shrinking flow. In fact, this is the first study to discover the second solution in the dusty fluid problem.
Computational fluid dynamics based study for analyzing heat transfer and friction factor in semi-circular rib-roughened equilateral triangular duct
Authors: Kumar Rajneesh , Kumar Anoop , Varun Varun
Published: March 2017

Purpose

The purpose of this computational fluid dynamics (CFD)-based study on semicircular rib-roughened equilateral triangular duct is to investigate heat transfer, friction factor and thermohydraulic performance parameter. The analysis is carried out by simulating problem in ANSYS (Fluent). The Reynolds number in the study varies from 4,000 to 24,000. Nusselt number is calculated for different Reynolds number using various turbulent models available in ANSYS (Fluent) for a smooth duct and compared the results with the Dittus–Boelter correlation.

Design/methodology/approach

The analysis has been done by solving basic fluid governing equations (continuity, momentum and energy) by using finite volume method (FVM). The semicircular ribs were fabricated on the absorber plate. The constant amount of heat flux is applied on the absorber plate, whereas other two walls are made adiabatic. The semi-implicit method for pressure linked equations (SIMPLE) algorithm is used with pressure–velocity-coupled disretization to estimate the results. The selection of turbulent model has been done on the basis of Nusselt number prediction in the smooth duct.

Findings

The renormalization-group k − ε model predicts the Nusselt number more accurately as compared to standard k − ε model, standard k − ω model, shear stress transport (SST) k − ω and realizable k − ε model in the Reynolds number ranges from 4,000 to 24,000 with a ± 5.5% deviation from Dittus–Boelter equation for smooth duct. The maximum thermo-hydraulic performance is observed of the order of 1.7 for arrangement which has a relative roughness height of 0.067 and relative roughness pitch of 7.5 at higher Reynolds Number of 24,000.

Originality/value

Although, many experimental studies are available in the area of rib-roughened ducts, the present study is based on CFD analysis of semicircular rib-roughened equilateral triangular duct and the results are predicted in terms of Nusselt number, friction factor and thermohydraulic performance parameter. Moreover, the predicted result of Nusselt number and friction factor is validated by comparing with Dittus–Boelter correlation and modified Blasius equation, respectively. This advantage made Fluent a powerful tool for analyzing the internal fluid flow through roughened ducts.
Natural convection in a partially heated wavy cavity filled with a nanofluid using Buongiorno’s nanofluid model
Authors: Pop Ioan , Sheremet Mikhail , Cimpean Dalia Sabina
Published: March 2017

Purpose

The main purpose of this numerical study is to provide a solution for natural convection in a partially heated, wavy cavity filled with a nanofluid using Buongiorno’s nanofluid model.

Design/methodology/approach

The domain of interest is a two-dimensional cavity bounded by an isothermal left wavy wall, adiabatic horizontal flat walls and right flat wall with a partial isothermal zone. To study the behaviour of the nanofluid, a two-phase Buongiorno mathematical model with the effects of the Brownian motion and thermophoresis is used. The governing dimensionless partial differential equations with corresponding boundary conditions were numerically solved by the finite difference method of the second-order accuracy using the algebraic transformation of the physical wavy cavity in a computational rectangular domain. The study has been conducted using the following values of the governing parameters: Ra = 104-106, Le = 10, Pr = 6.26, Nr = 0.1, Nb = 0.1, Nt = 0.1, A = 1, κ = 1-3, b = 0.2, hhs/L = 0.25, h1/L = 0.0-0.75 and τ = 0-0.25.

Findings

It is found that an increase in the undulation number leads to a weak intensification of convective flow and a reduction of
Nū because of more essential cooling of the wavy troughs where the temperature gradient decreases. Variations of the heater location show a modification of the fluid flow and heat transfer. The upper position of the heater reflects the minimum heat transfer rate, while the position between the bottom part and the middle section (h1/L = 0.25) characterizes an enhancement of heat transfer.

Originality/value

The originality of this work is to analyse the natural convection in a partially heated wavy cavity filled by a nanofluid using Buongiorno’s nanofluid model. The results will benefit scientists and engineers to become familiar with the flow behaviour of such nanofluids, and the way to predict the properties of this flow for possibility of using nanofluids in advanced nuclear systems, in industrial sectors including transportation, power generation, chemical sectors, ventilation, air-conditioning, etc.
An unlikely destination
Authors: Israel Marla , Goldberger Nancy , Vera Elizabeth , Heineke Amy
Published: March 2017

Purpose

The purpose of this paper is to describe a university-multi-school district partnership that positively affected the lives of P-12 immigrant, migrant and refugee students and their parents through an iterative collaboration of talent and resources among institutions.

Design/methodology/approach

This is a case study describing a university-school partnership grant-funded program detailing the processes, products, and implications for policy and practice.

Findings

University faculty and public school educators must work through intentional, contextually informed partnerships. It is through these partnerships that scarce resources of time, talent, and funds can be used wisely to build sustainable systems to educate students in K-12 schools and prepare future leaders for this work.

Research limitations/implications

This is a case study limited to the suburban Chicagoland area. Generalities to other communities cannot be directly made.

Originality/value

This study builds on the extant literature of university-school district partnerships and sustainable leadership theory by exploring the processes for creating iterative and individualized structures that benefit both university and public school districts. This study implores universities to re-examine priorities and purpose, especially within schools and colleges of education, in order to remain viable, relevant institutions for positive school improvement.
Effective school leadership and New York City’s immigrant and migrant children: a study
Authors: Watson Terri Nicol
Published: March 2017

Purpose

This paper provides insight into the effective education of immigrant and migrant children: many of whom are classified in New York City’s public schools as English language learners. It also highlights the ways in which New York City prepares school leaders and the policies that govern their actions.

Design/methodology/approach

Literature review.

Findings

The practices of New York City’s school leaders are governed by the Chancellor’s Regulations. These comprehensive mandates consist of four components and address issues related to students in grades K-12, school-based budgets, personnel matters, and parent and community engagement. In relation to students, including those classified as immigrant, migrant, and English language learners the Chancellor’s Regulation A-101 makes it clear: children may not be refused admission to a public school because of race, color, creed, national origin, gender, gender identity, pregnancy, immigration/citizenship status, disability, sexual orientation, religion, or ethnicity.

Research limitations/implications

Implications for future research: How can school leaders (and educational activists) continue to support and advocate for immigrant and migrant children under the presidency of Donald J. Trump.

Practical implications

Knowledge gleaned from this study may be of use to schools, districts, and educational leaders in the USA and abroad faced with similar demographic trends.

Social implications

This manuscript examined the ways in which The City University of New York prepares school leaders, the required State exams for school leaders, and the educational policies that govern the practices of New York City’s school leaders that are germane to English language learners.

Originality/value

This review of the literature may study may be of use to schools, districts, and educational leaders in the USA and abroad.
Maternal health services: an equal or framed territory?
Authors: Topa Joana Bessa , Nogueira Conceição Oliveira , Neves Sofia Antunes
Published: March 2017

Purpose

Despite the high prevalence of immigrant women at the national level, studies on migration have been indifferent to the gender perspective. The purpose of this paper is to discuss the engagement of Ukrainian immigrant women, one of the most expressive nationalities of female immigration in Portugal, on maternal and child healthcare services, exploring their perceptions and experiences in these contexts.

Design/methodology/approach

On the basis of critical and social constructionism assumptions, this research focusses on discourse. Assuming that immigrant women have access to different resources, as well as different competences to interpret and intervene within the context they are in (Topa et al., 2010; UNFPA, 2006), the best method to deeply understand their experiences was to analyse how discourse is organized and how it creates and produces meanings that become practices (Nogueira, 2001a). The present study adopted a qualitative methodology for collecting (semi-structured interviews) and analysing the data (thematic analysis) and was based on discourses of ten Ukrainian women, living in the metropolitan area of Oporto, who were pregnant or were mothers in Portugal.

Findings

Ukrainian women were misinformed about their legal rights and free access to maternal health services. Some dissatisfaction emerges among them with regard to the quality of information provided by health professionals and their communication skills. Their opinion is that they are given limited access to medical specialties, especially in primary care and that their doubts are inappropriately clarified during medical appointments.

Originality/value

This research also argues that cultural and intersectional considerations are fundamental to promote inclusive health policies for immigrants.