bluuebunny/crossref_metadata_2025 huggingface dataset:
Survival trends of grade I, II, and III astrocytoma patients and associated clinical practice patterns between 1999 and 2010: A SEER-based analysis
Authors: Dong Xuezhi , Noorbakhsh Abraham , Hirshman Brian R. , Zhou Tianzan , Tang Jessica A. , Chang David C. , Carter Bob S. , Chen Clark C.
Published: July 2015

Background

The survival trends and the patterns of clinical practice pertaining to radiation therapy and surgical resection for WHO grade I, II, and III astrocytoma patients remain poorly characterized.

Methods

Using the Surveillance, Epidemiology and End Results (SEER) database, we identified 2497 grade I, 4113 grade II, and 2755 grade III astrocytomas during the period of 1999–2010. Time-trend analyses were performed for overall survival, radiation treatment (RT), and the extent of surgical resection (EOR).

Results

While overall survival of grade I astrocytoma patients remained unchanged during the study period, we observed improved overall survival for grade II and III astrocytoma patients (Tarone-Ware P < .05). The median survival increased from 44 to 57 months and from 15 to 24 months for grade II and III astrocytoma patients, respectively. The differences in survival remained significant after adjusting for pertinent variables including age, ethnicity, marital status, sex, tumor size, tumor location, EOR, and RT status. The pattern of clinical practice in terms of EOR for grade II and III astrocytoma patients did not change significantly during this study period. However, there was decreased RT utilization as treatment for grade II astrocytoma patients after 2005.

Conclusion

Results from the SEER database indicate that there were improvements in the overall survival of grade II and III astrocytoma patients over the past decade. Analysis of the clinical practice patterns identified potential opportunities for impacting the clinical course of these patients.
Elizabeth Cary
Authors: Swan Jesse
Published: July 2015

Elizabeth Cary, Viscountess Falkland, was born in 1585 or 1586 to Elizabeth (née Symondes) and Lawrence Tanfield in Burford close to Woodstock, where the Lady Tanfield’s relations were prominent, notably Queen Elizabeth’s Champion, Sir Henry Lee. The Lord Tanfield was an upwardly mobile lawyer of the Inner Temple, eventually becoming Lord Chief Justice of the Exchequer and extensive landlord in and around Burford, including famously, because of his grandson, Lucius Cary, the second Viscount Falkland, owning the estate known as Great Tew. Cary was an only child and was married into the Cary family, notable for its close kinship relations to Queen Elizabeth. Eventually having eleven children, with one dying in infancy, Cary is remarkable in Catholic history as a powerful and effective champion of Catholicism in the Caroline court and for bringing six of her children into the Catholic Church, while she is remarkable in English literary history for authoring the first original play in English by a woman to be published in print (the play is The Tragedy of Mariam, the Fair Queen of Jewry) and being the first woman to author a modern-style history in English (that of the reign of Edward II). Exactly who and what kind of person Elizabeth Tanfield Cary, Viscountess Falkland, could be or should be has been and continues to be the most characteristic feature of the contemplations of Cary, from the time of her life to the present. Cary herself wondered who she could and should be as did many of the people of her life, including the daughter who was her first biographer, and the speculations and consideration of various possibilities continued, through the 19th century, when Cary was made into a champion of Anglo-Catholics, both masculine and feminine, and the 20th century, when Cary drew the interest of literary historians concerned with the development of modern biography and drama and then feminists concerned to correct masculinist literary history by reviving knowledge of the many quelled women writers. She should be gaining further interest as the centrality of translation in the early modern period is better integrated into emergent literary historiography. Some interest more recently has been expressed in departing from thinking about Cary as an individual and in various biographical ways in favor of using her works as touchstones for other matter, especially social and cultural, yet there continues to be interest in Cary as a woman and in her works as the expressions of a woman when modernity was still inchoate.
Scotland and the Atlantic World
Authors: Landsman Ned C.
Published: July 2015

For a small, resource-poor nation on the periphery of western Europe, few peoples had as conspicuous a presence in the world of the early modern Atlantic as did the Scots. Indeed, they would seem to have been outsized contributors to a whole range of activities in the Atlantic world: religion and education, migration and trade, medicine and botany, military affairs and imperial administration, and more—so much so that historians have begun to speak of a Scottish empire in the Atlantic. So extensive and so threatening did the Scottish presence seem that by the eve of the American Revolution, English people at home and North Americans in the colonies exhibited prominent instances of “Scotophobia.” Scots became famous for the extent of their loyalism during that conflict, even as Scottish influences became deeply embedded in the culture of British North America as it sought independence. Paradoxically, all of this occurred in spite of their having been relative latecomers to Atlantic involvement, and never dominant demographically. Yet their influence extended not only across the mainland British colonies that would become the United States, but also to the peripheries of settlement in Florida and the Canadian provinces as well as the Caribbean and beyond, eventually reaching Britain’s Asian empire as well. Historians long attributed the activism of the Scots to the 1707 Union of Parliaments, which, in creating a new United Kingdom opened up the American trade to Scottish participants in what was now a British empire. More recently they have come to recognize its roots in Scotland’s long history as an uncommonly migratory nation whose people regularly and prominently involved themselves abroad, including an unusual number of prominent and educated people. Indeed, as a poor and peripheral nation of the fringes of Europe, Scots had long before recognized that in order to develop their trade and find economic and cultural opportunities they would have to travel abroad to find them, and so Scots developed a skill for networking and a portable culture well suited to overseas involvement. That culture of Enlightenment proved to be influential overseas as well. It was in fact the very connectedness of Scots with places abroad on the European continent in the 17th century that limited their early involvement in the Atlantic world, and Atlantic traveling and trading never fully replaced those earlier connections.
Media Logic
Authors: Mazzoleni Gianpietro , Splendore Sergio
Published: July 2015

This entry offers a review of works in communication studies. It discusses the theoretical debate and empirical research that have contributed to define, highlight, and expand the concept of “media logic.” The concept is grounded in the media sociology perspective, but it acquires an interdisciplinary nature from its numerous applications in different domains. Media logic is connected both with the ideas of production of media content and with the area of media effects. From the production perspective, the concept leans on the sociology of journalism, and particularly on studies of newsmaking. In this sense, media logic consists predominantly of a formatting logic that determines the classification of materials, the choice of mode of presentation, and the selection of social experience. When David Altheide and Robert Snow—in Altheide and Snow 1979 and Altheide and Snow 1991 (both cited under Core Texts)—worked out the concept of media logic, they pointed at the formats, the processes by which media produce their content. The “media logic” refers to the organizational, technological, and aesthetic determinants of media functioning, including the ways in which they allocate material and symbolic resources and work through formal and informal rules. If media logic refers to the processes for constructing messages within a particular medium, “format” becomes a key term because it refers to the rules and codes for defining, selecting, and presenting media content. From the perspective of media effects, the concept also envisions the impact media have on institutions. One popular theoretical development of the media logic approach is the concept of “mediatization” of society. The media logic is seen as the ‘engine’ of the processes of mediatization. Mediatization is then the result of the influence of mass communication on society, where many societal institutions, politics especially (Mazzoleni and Schulz 1999, cited under Journal Articles on Mediatization of Politics), adapt themselves, their aims, their statutes, their conducts, and their logics to typical production formats and imperatives, mainly of a commercial nature, of modern communications. Schulz 2004 (cited under Mediatization) explains such processes in terms of “extension, substitution, amalgamation and accommodation.” However, the establishment of digital media environments prompts scholarly reflection on developing new theoretical perspectives, looking beyond traditional ‘formats’ (Klinger and Svensson 2015, cited under Digital Media Logic).
Social Class
Authors: Levin Erica
Published: July 2015

In contemporary film studies, the term class often appears as part of the trio of terms race/class/gender. Attention to social class figures as a factor in both film production and reception. Much of the writing on social class in film studies falls on one side of this divide or the other. The analysis of class in film studies is informed by two major but distinct theoretical approaches to the concept of class, one provided by Karl Marx and the other by Max Weber. For Marx, a class is defined in terms of its relationship to the means of production, while for Weber, class is determined by education and the development of particular skills. How class is defined theoretically often remains implicit in the mode of analysis. Approaches to the study of class that focus on cinematic representation often begin from a set of assumptions developed out of Marxist methods of analysis in which cultural forms are understood to be the manifestation of economic and political relationships. Approaches to class that focus on cinema’s construction of class identity implicitly begin from theoretical ground established by Weber, where class status is something that can be acquired or developed. Theories of class have necessarily evolved in response to the rise of globalization and neoliberalism, and new scholarship focuses on issues of the breakdown between labor and leisure as well as questions raised by the enduring (or waning) power of civil society and the nation-state. Additionally, specific historical political movements have spurred inquiry into cinema’s power not only to consolidate, but also to challenge class interests.
Genitourinary Procedures as Risk Factors for Prosthetic Hip or Knee Infection: A Hospital-Based Prospective Case-Control Study
Authors: Gupta Arjun , Osmon Douglas R. , Hanssen Arlen D. , Lightner Deborah J. , Wilson Walter R. , Steckelberg James M. , Baddour Larry M. , Harmsen William S. , Mandrekar Jay N. , Berbari Elie F.
Published: July 2015

Background.  The purpose of this study was to determine the risk of prosthetic joint infection (PJI) as a complication of routine genitourinary (GU) procedures in patients with total hip arthroplasty (THA) or total knee arthroplasty (TKA) and to study the impact of antibiotic prophylaxis administered prior to these procedures.

Methods.  We conducted a prospective, single-center, case-control study between December 1, 2001 and May 31, 2006. Case patients were hospitalized with total hip or knee PJI. Control subjects underwent a THA or TKA and were hospitalized during the same period on the same orthopedic floor without a PJI. Data regarding demographic features and potential risk factors were collected. The outcome measure was the odds ratio (OR) of PJI after GU procedures performed within 2 years of admission.

Results.  A total of 339 case patients and 339 control subjects were enrolled in the study. Of these, 52 cases (15%) and 55 controls (16%) had undergone a GU procedure in the preceding 2 years. There was no increased risk of PJI for patients undergoing a GU procedure with or without antibiotic prophylaxis (adjusted OR [aOR] = 1.0, 95% confidence interval [CI] = 0.2–4.5, P = .95 and aOR = 1.0, 95% CI = 0.6–1.7, P = .99, respectively). Results were similar in a subset of patients with a joint age less than 6 months, less than 1 year, or greater than 1 year.

Conclusions.  Genitourinary procedures were not risk factors for subsequent PJI. The use of antibiotic prophylaxis before GU procedures did not decrease the risk of subsequent PJI in our study.
Low Vitamin D Levels are Associated With Need for Surgical Correction of Pediatric Fractures
Authors: Minkowitz Barbara , Cerame Barbara , Poletick Eileen , Nguyen Joseph T. , Formoso Nicole D. , Luxenberg Sherri L. , Lee Ben H. , Lane Joseph M.
Published: July 2015

Background:

There is growing concern over the relationship between the severity of pediatric fractures and low vitamin D [25-hydroxyvitaminD (25(OH)D)] status.

Objective:

Compare 25(OH)D levels and lifestyle of children with fractures to nonfracture controls to determine if 25(OH)D levels are associated with fractures and if there is a 25(OH)D fragility fracture threshold.

Methods:

Pediatric fracture and nonfracture controls were included. Bone health survey and medical record data were analyzed. Fractures were categorized using the Abbreviated Injury Scale (AIS). AIS 3 fractures were identified as fractures that required surgical intervention. Univariate and multivariable ordinal regression analyses were performed to identify potential risk factors for increased fracture severity.

Results:

A total of 369 fracture patients and 662 nonfracture controls aged 18 years and younger were included. Both groups’ 25(OH)D levels were comparable. 25(OH)D was 27.5±8.9 in the fracture group compared with 27.4±9.1 ng/mL in nonfracture controls (P=0.914). AIS 3 fractures had lower 25(OH)D levels (24.6±9.3 ng/mL) versus AIS 1 and 2 (30.0±10.8 and 28.3±8.4, respectively, P=0.001). Univariate correlations for AIS severity were found with age (P=0.015) and outdoor playtime (P=0.042). Adjusted odds ratios for 25(OH)D levels <12 ng/mL was 55.4 (P=0.037), 25(OH)D between 12 and 20 ng/mL was 6.7 (P=0.039), 25(OH)D between 20 and 30 ng/mL was 2.8 (P=0.208), and 25(OH)D between 30 and 40 was 1.7 (P=0.518).

Clinical Relevance:

Occurrence of a pediatric fracture was not associated with 25(OH)D levels in our study. However, children with lower vitamin D levels were found to be at higher risk for more severe fractures. Early evidence suggests that the target serum level for 25(OH)D should be at least 40 ng/mL in patients less than 18 years of age as the relative risk of more severe fractures increased as 25(OH)D levels decreased <40 ng/mL.

Level of Evidence:

Level III.
Daniel Frank Walls FRSNZ. 13 September 1942 — 12 May 1999
Authors: Knight Sir Peter , Milburn Gerard J.
Published: July 2015

Dan Walls, a pioneer of quantum optics and especially the study of non-classical light, died in Auckland on 12 May 1999 after a battle with cancer, at the age of 57 years. Dan Walls completed a PhD with Roy Glauber at Harvard in 1969 and joined the University of Waikato in 1972. Together with his colleague Crispin Gardiner, during the next 25 years he established a major research centre for theoretical quantum optics in New Zealand and built active and productive collaborations with groups throughout the world.
Crystal structure of 1-(4-fluorophenyl)-4-(4-methoxyphenyl)-1H-1,2,3-triazole
Authors: Kumar Balbir , Bhardwaj Madhvi , Paul Satya , Kant Rajni , Gupta Vivek K.
Published: July 2015

In the title compound, C15H12FN3O, the triazole ring forms dihedral angles of 30.57 (8) and 21.81 (9)° with the fluoro-substituted and methoxy-substituted benzene rings, respectively. The dihedral angle between the benzene rings is 51.53 (7)°. In the crystal, π–π interactions between the triazole rings [centroid–centroid seperations = 3.774 (2) and 3.841 (2) Å] form chains along [010].
Crystal structures of vortioxetine and its methanol monosolvate
Authors: Zhou Xin-Bo , Gu Jian-Ming , Sun Meng-ying , Hu Xiu-Rong , Wu Su-Xiang
Published: July 2015

Vortioxetine, C18H22N2S, (1), systematic name 1-{2-[(2,4-dimethylphenyl)sulfanyl]phenyl}piperazine, a new drug used to treat patients with major depressive disorder, has been crystallized as the free base and its methanol monosolvate, C18H22N2S·CH3OH, (2). In both structures, the vortioxetine molecules have similar conformations: in (1), the dihedral angle between the aromatic rings is 80.04 (16)° and in (2) it is 84.94 (13)°. The C—S—C bond angle in (1) is 102.76 (14)° and the corresponding angle in (2) is 103.41 (11)°. The piperazine ring adopts a chair conformation with the exocyclic N—C bond in a pseudo-equatorial orientation in both structures. No directional interactions beyond normal van der Waals contacts could be identified in the crystal of (1), whereas in (2), the vortioxetine and methanol molecules are linked by N—H...O and O—H...N hydrogen bonds, generating [001] chains.
Crystal structure of 5-hydroxymethyl-2-methoxyphenol
Authors: Hassan Mubashir , Ashraf Zaman , Seo Sung-Yum , Kim Daeyoung , Kang Sung Kwon
Published: July 2015

In the title compound, C8H10O3, the hydroxymethyl group is twisted by 74.51 (13)° from the plane of the benzene ring to which it is connected. By contrast, the benzene and methoxy groups are almost coplanar, making a dihedral angle of 4.0 (2)°. In the crystal, O—H...O hydrogen bonds link the molecules into a three-dimensional network.
Crystal structure of 2,6-dimethyl-4-pyridone hemihydrate
Authors: Nguyen Dalena M. , Desikan Vasumathi , Golen James A. , Manke David R.
Published: July 2015

The title compound (systematic name: 2,6-dimethyl-1H-pyridin-4-one hemihydrate), C7H9NO·0.5H2O, has a single planar molecule in the asymmetric unit with the non-H atoms possessing a mean deviation from planarity of 0.021 Å. There is also half of a water molecule present in the asymmetric unit. In the crystal, infinite (001) sheets are formed by N—H...O and O—H...O hydrogen bonds.
Crystal structure of [1,1′′′-bis(pyrimidin-2-yl)-4,4′:2′,2′′:4′′,4′′′-quaterpyridine-1,1′′′-diium-κ2N1′,N1′′]bis[2-(pyridin-2-yl)phenyl-κ2N,C1]iridium(III) tris(hexafluoridophosphate) acetonitrile trisolvate
Authors: Coe Benjamin J. , Peers Martyn K. , Raftery James , Scrutton Nigel S.
Published: July 2015

In the title compound, [Ir(C11H8N)2(C28H20N8)](PF6)3·3CH3CN or [IrIII(ppy)2{(2-pym)2qpy2+}](PF6)3·3CH3CN (ppy = deprotonated 2-phenylpyridine, pym = pyrimidyl and qpy = 4,4′:2′,2′′:4′′,4′′′-quaterpyridyl), the Ir3+cation is coordinated by two C atoms and four N atoms in a slightly distorted octahedral geometry. The asymmetric unit consists of one complex trication, three hexafluoridophosphate anions and three acetonitrile solvent molecules. The average Ir—C distance is 2.011 (14) Å, the average Ir—N(ppy) distance is 2.05 (6) Å and the average Ir—N(qpy) distance is longer at 2.132 (10) Å. The dihedral angles within the 4,4′-bipyridyl units are 31.5 (6) and 23.8 (7)°, while those between the 2-pym and attached pyridyl rings are rather smaller, at 11.7 (9) and 7.1 (9)°. The title compound was refined as a two-component inversion twin.
Crystal structure of (E)-4-(acetoxyimino)-N-allyl-3-isopropyl-2,6-diphenylpiperidine-1-carbothioamide
Authors: Mohandas T. , Krishnan K. Gokula , Balamurugan S. , Harrison William T. A. , Thanikachalam V. , Sakthivel P.
Published: July 2015

The title compound, C26H31N3O2S, crystallizes with two molecules (AandB) in the asymmetric unit. In each case, the piperidine ring exists in a twist-boat conformation. The dihedral angle between the phenyl rings is 46.16 (12)° in moleculeAand 44.95 (12)° in moleculeB. In both molecules, the allyl side chain is disordered over two orientations in a 0.649 (9):0.351 (9) ratio for moleculeAand 0.826 (10):0.174 (10) ratio for moleculeB. In the crystal, neither molecule forms a hydrogen bond from its N—H group, presumably due to steric hindrance.A+AandB+Binversion dimers are formed, linked by pairs of weak C—H...O hydrogen bonds enclosingR22(22) ring motifs.
Crystal structure of 3-amino-1-(4-hydroxyphenyl)-1H-benzo[f]chromene-2-carbonitrile
Authors: Akkurt Mehmet , Horton Peter N. , Younes Sabry H. H. , Mohamed Shaaban K. , Albayati Mustafa R.
Published: July 2015

In the title compound, C20H14N2O2, the hydroxybenzene ring is almost perpendicular to the mean plane of the naphthalene ring system, making a dihedral angle of 85.56 (4)°. The 4H-pyran ring fused with the naphthalene ring system has a flattened boat conformation. In the crystal, O—H...N and N—H...O hydrogen bonds link the molecules into a supramolecular layer in thebcplane; N—H...π interactions also contribute to this arrangement. The layers are linked by weak by C—H...π and π–π [inter-centroid separation = 3.8713 (7) Å] interactions.
A new monoclinic polymorph of 1,1′-bis(diphenylthiophosphoryl)ferrocene
Authors: Tan Yee Seng , Yeo Chien Ing , Tiekink Edward R. T.
Published: July 2015

The title compound, [Fe(C17H14PS)2], is a second monoclinic polymorph (P21/c, withZ′ = 1) of the previously reported monoclinic (C2/c, withZ′ = 1/2) form [Fanget al.(1995).Polyhedron,14, 2403–2409]. In the new form, the S atoms lie to the same side of the molecule with the pseudo S—P...P—S torsion angle being −53.09 (3)°. By contrast to this almostsyndisposition, in theC2/cpolymorph, the Fe atom lies on a centre of inversion so that the S atoms are strictlyanti, with a pseudo-S—P...P—S torsion angle of 180°. The significant difference in molecular conformation between the two forms does not result in major perturbations in the P=S bond lengths nor in the distorted tetrahedral geometries about the P atoms. The crystal packing of the new monoclinic polymorph features weak Cp—C—H...π(phenyl) interactions consolidating linear supramolecular chains along theaaxis. These pack with no directional interactions between them.
Evaluating hotels rating prediction based on sentiment analysis services
Authors: López Barbosa Rutilio Rodolfo , Sánchez-Alonso Salvador , Sicilia-Urban Miguel Angel
Published: July 2015

Purpose

– The purpose of this paper is to assess the reliability of numerical ratings of hotels calculated by three sentiment analysis algorithms.

Design/methodology/approach

– More than one million reviews and numerical ratings of hotels in seven cities in four countries were extracted from TripAdvisor web site. Reviews were classified as positive or negative using three sentiment analysis tools. The percentage of positive reviews was used to predict numerical ratings that were then compared with actual ratings.

Findings

– All tools classified reviews as positive or negative in a way that correlated positively with numerical ratings. More complex algorithms worked better, yet predicted ratings showed reasonable agreement with actual ratings for most cities. Predictions for hotels were less reliable if based on less than 50-60 percent of available reviews.

Practical implications

– These results validate that sentiment analysis can be used to transform unstructured qualitative data on user opinion into quantitative ratings. Current tools may be useful for summarizing opinions of user reviews of products and services on web sites that do not require users to post numerical ratings such as traveler forums. This summarizing may be valuable not just to potential users, but also to the service and product providers and offers validation and benchmarking for future improvement of opinion mining and prediction techniques.

Originality/value

– This work assesses the correlation between sentiment analysis of hotels’ reviews and their actual ratings. The authors also evaluated the reliability of results of sentiment analysis calculated by three different algorithms.
Miniaturized stacked implant antenna design at ISM band with biocompatible characteristics
Authors: Kaka Ademola O. , Toycan Mehmet , Walker Stuart D.
Published: July 2015

Purpose

– A vertically stacked, three layer hybrid Hilbert fractal geometry and serpentine radiator-based patch antenna is proposed and characterized for medical implant applications at the Industrial, Scientific and Medical band (2.4-2.48 GHz). Antenna parameters are optimised to achieve miniaturized, biocompatible and stable transmission characteristics. The paper aims to discuss these issues.

Design/methodology/approach

– Human tissue effects on the antenna electrical characteristics were simulated with a three-layer (skin, fat and muscle) human tissue model with the dimensions of 180×70×60 mm3 (width×height×thickness mm3). Different stacked substrates are utilized for the satisfactory characteristics. Two identical radiating patches are printed on Roger 3,010 (ε
r=10.2) and Alumina (ε
r=9.4) substrate materials, respectively. In addition, various superstrate materials are considered and simulated to prevent short circuit the antenna while having a direct contact with the metallization, and achieve biocompatibility. Finally, superstrate material of Zirconia (ε
r=29) is used to achieve biocompatibility and long-life. A finite element method is used to simulate the proposed hybrid model with commercially available Ansoft HFSS software.

Findings

– The antenna is miniaturized, having dimensions of 10×8.4×2 mm3 (width×height×thickness mm3). The resonance frequency of the antenna is 2.4 GHz with a bandwidth of 100 MHz at return loss (S11) of better than −10 dB characteristics. Overall, the proposed antenna have 50 Ω impedance matching, −21 dB far field antenna gain, single-plane omni-directional radiation pattern properties and incident power of 5.3 mW to adhere Specific Absorption Rate regulation limit.

Originality/value

– Vertically stacked three layer hybrid design have miniaturized characteristics, wide bandwidth, biocompatible, and stable characteristics in three layer human tissue model make this antenna suitable for implant biomedical monitor systems. The advanced simulation analysis of the proposed design constitutes the main contribution of the paper.
Design and implementation of maximum constant boost switched inductor z-source inverter for three-phase on-line uninterrupted power supply
Authors: Chitra K. , Jeevanandham A.
Published: July 2015

Purpose

– The purpose of this paper is to present the Switched Inductor Z-Source Inverter (SLZSI) topology for three-phase on-line uninterruptible power supply (UPS) by employing third harmonic injected maximum constant boost pulse width modulation (PWM) control. Conventional UPS consists of step-up transformer or boost chopper along with voltage source inverter (VSI) which reduces the efficiency and increases energy conversion cost. The proposed three-phase UPS by using SLZSI has the voltage boost capability through shoot through zero state which is not available in traditional VSI and current source inverter.

Design/methodology/approach

– Performance of three-phase on-line UPS based on ZLZSI by using third harmonic injected maximum constant boost PWM control is analyzed and evaluated in MATLAB/Simulink software and the results are compared with Z-source inverter (ZSI) fed UPS. Experimental results are presented for the validation of the simulation and theoretical analysis.

Findings

– The output voltages, currents, THD values, voltage stress and efficiencies for different loading condition are determined and compared with the theoretical values and UPS with ZSI. The experimental results validate the theoretical and simulation results.

Originality/value

– Compared with the traditional ZSI, the SLZSI provides high-voltage boost inversion ability with a very short shoot through zero state. This proposed UPS by using SLZSI increases the efficiency with less number of components, reduces the harmonics, increases the voltage gain and reduces the voltage stress.
Analysis of finite frequency selective surfaces backed by dielectric substrate using sub-entire-domain basis function method
Authors: Wang Quan-Quan , Zhu Hong-Bo , Chen Ru-Shan , Hu Yun-Qin
Published: July 2015

Purpose

– Analysis of the frequency selective surface (FSS) is of great significance. In the method of moments, when the electric size of the FSS increases, huge in-core memory and CPU time are required. The purpose of this paper is to efficiently analyze the finite FSS backed by dielectric substrate utilizing sub-entire-domain (SED) basis function method.

Design/methodology/approach

– Different types of SED basis functions are generated according to the locations of the cells in the entire structure, and a reduced system is constructed and solved. The couplings of all cells of the FSS are taken into account by using Green’s function and Galerkin’s test procedure. The spatial Green’s function is obtained with the discrete complex image method. The reflection and transmission coefficients of the FSS are calculated using the far field of the FSS and the metallic plate with the same size.

Findings

– Moderate problems of the finite FSS backed by dielectric substrate are solved with the SED basis function method. The original problem can be simplified to two smaller problems. It enables a significant reduction to the matrix size and storage, and efficient analysis of FSS can be performed. The band-stop type of FSS can be composed of periodic conductive patch cells on the dielectric substrate, and shows total reflection property at the resonant frequency.

Originality/value

– The SED basis function method is mostly used to analyze periodic PEC structures in free space. The layered medium Green’s function is successfully employed and several dielectric substrate backed finite FSSs are discussed in this paper. The calculation of reflection and transmission coefficients, which are more effective rather than far field scattering of the FSS, are described.
Response of personal exposimeters for exposure assessment in the GSM900 downlink band
Authors: Thielens Arno , Agneessens Sam , Vermeeren Günter , Verloock Leen , Rogier Hendrik , Martens Luc , Joseph Wout
Published: July 2015

Purpose

– The purpose of this paper is to numerically determine the distribution of electric fields registered by a personal exposimeter (PEM) used for the Global System for Mobile Communications (GSM) around 900 MHz (GSM900) downlink (DL) band and compare these with calibration measurements of PEMs worn by real human subjects.

Design/methodology/approach

– Numerical simulations using the Virtual Family Male (VFM) are carried out at 950 MHz in order to determine the electric fields surrounding the phantom in realistic, far-field environments. These electric fields can be used to determine the distribution of a PEM’s response when worn by the VFM. Simultaneously, calibration measurements in an anechoic chamber are carried out using a real PEM worn by two different subjects, in order to determine the PEM’s response experimentally.

Findings

– Both the numerical simulations and the measurements show that a PEM will on average underestimate the incident electric fields in the GSM900 DL band and that the variation (expressed in terms of the 95 percent confidence interval and the interquartile distance) on its response is relatively large: a 95 percent confidence interval of 22 dB and an interquartile distance of 7.3 dB are found in a realistic environment using numerical simulations, while the calibration measurements show interquartile distances up to 12 dB. In terms of variation there is an excellent agreement between simulations and measurements.

Originality/value

– This paper proves that numerical simulations may be used as a replacement for the more time- and work-consuming calibration measurements if the variation of a PEM’s response is studied.
Using multiple exposimeters to evaluate the influence of the body when measuring personal exposition to radio frequency electromagnetic fields
Authors: Nájera López Alberto , Gonzalez-Rubio Jesus , Villalba Montoya José Manuel , Arribas Garde Enrique
Published: July 2015

Purpose

– Since first small personal exposimeters became available, some studies have characterized personal exposition to radio frequency electromagnetic fields. The effect of body and relative position of the exposimeter have been also analyzed but some questions are still unanswered. The paper aims to discuss these issues.

Design/methodology/approach

– Using three personal exposimeters in four different subjects, the authors characterized and compared measurements in a controlled experiment.

Findings

– The authors found statistically significance differences between exposimeters and subjects due to relative position (right and left) and a control position far from the body (center). It should indicate that body and relative position of the exposimeter affect directly to the measurement, conditioning final and average results.

Research limitations/implications

– Measurements using personal exposimeters have to be reconsidered and controlled.

Originality/value

– The authors test personal exposimeters limitations in real conditions.
Reactance components embedded in printed circuit boards
Authors: Stęplewski Wojciech , Dziedzic Andrzej , Kłossowicz Adam , Winiarski Paweł , Borecki Janusz , Kozioł Grażyna , Serzysko Tomasz
Published: July 2015

Purpose

– This paper aims to report the investigations of capacitors and inductors embedded into printed circuit boards (PCBs) designed in various layouts.

Design/methodology/approach

– The research were focused on the components embedded into four-layer PCBs with different structures of the inner layers. Three special capacitive laminates for manufacturing of thin-film embedded capacitors and several types of coils in the form of a spiral, meander and solenoid are described. In addition, a part of the spiral-type coils was formed with an aperture in the center in which the magnetic core, made of soft magnetic composites’ material was placed to increase the coil inductance.

Findings

– Various constructions of embedded capacitors and coils were designed and manufactured. Capacitance and loss tangent of capacitors to determine the repeatability of the production process were determined. Capacitor’s long-term stability analysis was performed by exposing test samples to elevated temperatures (70, 100 or 130°C), realized with the aid of heating plate, for at least 160 h. The temperature characteristics for the capacitance and loss tangent from 15 to 100°C were determined. Also the induction of different designs and layouts coils was determined.

Originality/value

– The wide parameters’ characterization of capacitors and coils embedded into PCBs allow the analysis of their properties with regard to their practical application. The promising results of the realized measurements show that the capacitors and induction coils with studied structures can be widely used in the construction of embedded circuits into PCBs (e.g. filters, radio frequency identification systems and generators).
Graphene electrodes for voltammetric measurements in biological fluids
Authors: Peplowski Andrzej , Janczak Daniel , Wróblewski Grzegorz , Słoma Marcin , Górski Łukasz , Malinowska Elżbieta , Pałko Tadeusz , Jakubowska Małgorzata
Published: July 2015

Purpose

– The aim of this paper was to verify applicability of graphene-based sensors for voltammetric and amperometric measurements of low-concentration compounds in biological fluids.

Design/methodology/approach

– Using the screen printing method, electrochemical sensors were manufactured on polymethylmetacrylate foil using a paste consisting of organic solvents and graphene nanopetals. As the model of a biological fluid tear film was chosen, the compound chosen as the analyte was H2O2, which is produced in oxidation of biological compounds. Tear film analog was prepared, in which, the measurements were carried out in a wide range of concentrations to determine the oxidation potential of H2O2through square-wave voltammetry. The second series of amperometric measurements was carried out for concentrations between 0 and 30 μM/L, which is the lower range of physiological glucose concentration in tear films.

Findings

– The sensors presented linearity for concentrations from 0 to 3.5 per cent. Mean linear correlation coefficient between the peak current and the concentration for the examined sensors was 0.9764. Mean sensitivity was 434.4 mA·M−1·L−1.

Research limitations/implications

– Results indicate a need for optimization of the sensors ' performance. Main parameters to be improved are surface area of electrodes and purity of the graphene layer, as well as uniformity of the manufacturing process to improve accuracy and repeatability of measurements.

Practical implications

– Technology and materials used present an opportunity for creating low-cost, miniaturized and biocompatible sensors to be used in medical monitoring.

Originality/value

– Printed electronics technology described was not investigated previously in the field of biological sensors and could contribute to the solving of vital medicine problems.
Copper deposition on screen printed electrical paths for solar cell application
Authors: Drabczyk Kazimierz , Socha Robert P. , Skwarek Agata
Published: July 2015

Purpose

– The aim of this paper is to present results of investigations carried out on the front electrode of solar cells. Nowadays, most worldwide solar cell production is dominated by monocrystalline and polycrystalline silicon as a base material. In such cells, the electrical carriers are collected by the system of metallic paths fabricated on a silicon surface. One possible way to increase cell efficiency and reduce the production costs of solar modules is to replace the expensive silver by cheaper copper in front metallic electrodes.

Design/methodology/approach

– The paper presents results of investigations performed on the front electrode of the solar cell. The investigations were focused on the modification of typical screen printing fabrication of the thin electrical finger paths of the front solar cell electrode. The resulting contacts were characterized morphologically (the dimensions and geometry of the front contacts) by scanning electron microscopy. The composition of finger path covered with copper was analyzed using energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

Findings

– In this work, the front electrodes were screen printed with the use of conventional silver-paste on a p-type Cz–Si-textured wafer with a n+ emitter and with an antireflection coating. After that, the fired front electrode was electroless coated with copper. The electroless copper deposition was performed in two stages. First, the surface of the photovoltaic cell was dipped in an aqueous solution of CuSO4 and then dried in air at room temperature. When the surface dried, the cell was immersed in hydrogen fluoride solution (5 per cent) for 1 s followed by rinsing in deionization water.

Originality/value

– The experiments confirmed the potential application of copper as an additional layer of the solar cell front metal electrode. On the one hand, this process is very simple and, on the other, the authors demonstrate a problem with the mechanical stability of the covered paths leading to electrode delamination.
Carbon nanomaterials dedicated to heating systems
Authors: Wroblewski Grzegorz , Kielbasinski Konrad , Swatowska Barbara , Jaglarz Janusz , Marszalek Konstanty , Stapinski Tomasz , Jakubowska Malgorzata
Published: July 2015

Purpose

– The paper aims to present the research results related to transparent heating elements made from carbon nanomaterials. Heating elements were fabricated only with cost-effective techniques with the aim to be easily implemented in large area applications. Presented materials and methods are an interesting alternative to vacuum deposition of transparent resistive layers and etching of low-resistive patterns. Fabricated heating elements were designed to be used as de-icing structures in roof-top windows.

Design/methodology/approach

– The paper presents the research results related to transparent heating elements made from carbon nanomaterials. Heating elements were fabricated only with cost-effective techniques with the aim to be easily implemented in large area applications. Presented materials and methods are an interesting alternative to vacuum deposition of transparent resistive layers and etching of low-resistive patterns. Fabricated heating elements were designed to be used as de-icing structures in roof-top windows.

Findings

– The sheet resistance of obtained layers was between 9 and 11 kΩ/□; however, double-walled carbon nanotubes showed significantly higher optical transmission (around 70 per cent) than graphene nanoplatelets (around 55 per cent for visible and near infrared range). The amount of polymer resin had the influence on the paints stability, electrical properties and coatings adhesion.

Originality/value

– Results show a novel method of fabrication of a large area and transparent heating elements with tunable resistance done through the change of spray coating paint composition.
Modeling creep in a variable thickness rotating FGM disc under varying thermal gradient
Authors: Garg Manish , Salaria B S , Gupta V K
Published: July 2015

Purpose

– The purpose of this paper is to investigate steady state creep behavior of a functionally graded rotating disc under varying thermal gradient (TG).

Design/methodology/approach

– The steady state creep in a rotating FGM disc with linearly varying thickness has been investigated by using von-Mises yield criterion. The disc under investigation is assumed to be made of FGM containing non-linear distribution of silicon carbide particle (SiCp) in a matrix of pure aluminum along the radial distance. The creep behavior of the FGM composite disc is described by threshold stress-based law. The stresses and strain rates in the FGM disc have been estimated for different kinds of TG.

Findings

– The results indicate that when the FGM disc is subjected to a radial TG, with temperature increasing with increasing radius, the radial stress in the disc increases over the entire disc but the tangential and effective stresses increase near the inner radius and decrease toward the outer radius. The imposition of such a radial TG in the FGM disc leads to significant reduction in the radial and tangential strain rates. With the increase in magnitude of TG in the FGM disc, the inhomogeneity in creep stresses increases but the inhomogeneity in strain rates decreases significantly, thereby reducing the chances of distortion in the FGM disc.

Originality/value

– The creep strain rates in rotating FGM disc could be significantly reduced when the disc is subjected to a radial TG, with temperature increasing with increasing radius.
CFD investigation of inlet pressure effects on the energy separation in a vortex tube with convergent nozzles
Authors: Pourmahmoud Nader , Rashidzadeh Masoud , Hassanzadeh Amir
Published: July 2015

Purpose

– The purpose of this paper is to investigate the effect of convergent nozzles on the thermal separation inside a vortex tube, using a three-dimensional (3D) computational fluid dynamics (CFD) model as predicting tool.

Design/methodology/approach

– The 3D finite volume formulation with the standard k-ε turbulence model has been used to carry out all the computations. Six different nozzles for convergence angle have been utilized β=0, 2, 4, 6, 8 and 10°. All other geometrical parameters were considered fixed at the experimental condition, i.e. main tube and chamber sizes and 294.2 K of gas temperature at inlets.

Findings

– The numerical results present that there is an optimum convergence angle for obtaining the highest efficiency and β=2° is the optimal candidate under the simulations. It can be pointed that, some numerical data are validated by the available experimental results which show good agreement.

Practical implications

– It is a useful and simple design of nozzle injectors to achieve the maximum cooling capacity.

Originality/value

– In the work with assuming the advantages of using convergent nozzles on the energy separation and their considerable role on the creation of maximum cooling capacity of machine, the shape of nozzles was concentrated. This research believes that choosing an appropriate convergence angle is one of the important physical parameters. So far, an effective investigation toward the optimization of convergent nozzles has not been done but the importance of this subject can be regarded as an interesting research theme; so that the machine would operate in the way that the maximum cooling effect or the maximum refrigeration capacity is provided.
Some modifications for ES-FEM and its application for vehicle design
Authors: Huang Guanxin , Wang Hu , Li Guangyao
Published: July 2015

Purpose

– The purpose of this paper is to enhance the feasibility of the edge-based smoothed triangular (EST) element, some modifications are made in this study.

Design/methodology/approach

– First, an efficient strategy based on graph theory is proposed to construct the edge system. Second, the stress is smoothed in global coordinate system based on edge instead of strain, which makes the theory of EST more rigorous and can be easily extended to the situation of multi elements sharing the same edge. Third, the singular degree of freedoms (DOFs) of the nodes linked by edges are restrained in edge local coordinate system, which makes the global stiffness matrix non-singular and can be decomposed successfully.

Findings

– First, an efficient edge constructing strategy can make EST element more standout. Second, some modifications should be made to EST element to extend it to the situation with multi elements sharing the same edge, so that EST element can deal with the geometrical models with this kind of features. Third, the way to restrain the singular DOFs of EST element must be different from normal isoparametric triangle element, because the stiffness matrix of the smoothing domain is not computed in local coordinate system.

Originality/value

– The modified EST element performs stably in engineering analysis including large scale problems and the situation with multi elements sharing the same edge, and the efficiency of edge system constructing is no longer the bottleneck.
A simplified and efficient hybrid finite element model (HYMOD) for non-linear 3D simulation of RC structures
Authors: Markou George , Papadrakakis Manolis
Published: July 2015

Purpose

– The purpose of this paper is to present a simplified hybrid modeling (HYMOD) approach which overcomes limitations regarding computational cost and permits the simulation and prediction of the nonlinear inelastic behavior of full-scale RC structures.

Design/methodology/approach

– The proposed HYMOD formulation was integrated in a research software ReConAn FEA and was numerically studied through the use of different numerical implementations. Then the method was used to model a full-scale two-storey RC building, in an attempt to demonstrate its numerical robustness and efficiency.

Findings

– The numerical results performed demonstrate the advantages of the proposed hybrid numerical simulation for the prediction of the nonlinear ultimate limit state response of RC structures.

Originality/value

– A new numerical modeling method based on finite element method is proposed for simulating accurately and with computational efficiency, the mechanical behavior of RC structures. Currently 3D detailed methods are used to model single structural members or small parts of RC structures. The proposed method overcomes the above constraints.