bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupled optical and electrical analysis for thin-film solar cells with embedded dielectric nanoparticles
Authors: Mopurisetty Sundara Murthy , Bajaj Mohit , Sathaye Ninad D , Ganguly Swaroop
Published: January 2015

Combined optical and electrical simulations were performed for thin-film (silicon) solar cell structures with dielectric (silicon-dioxide) nanoparticles embedded in the active region for efficiency enhancement. The efficiency enhancement due to optimally sized nanoparticles is found to be 22% and 15% in the constant coverage area and constant pitch configurations, respectively; further, the enhancement qualitatively follows the trends expected from optical-only simulations. This, however, assumes a good quality dielectric-semiconductor interface, whereas heavy recombination at this interface is seen to degrade the efficiency significantly—setting an upper limit on the surface recombination velocity up to which embedding nanoparticles is beneficial.
Origin of magnetic bistability in rapidly solidified (Co0.94Fe0.06)72.5Si12.5B15 nearly zero magnetostrictive amorphous nanowires
Authors: Óvári T.-A. , Chiriac H.
Published: January 2015

Results on the analysis of the magnetoelastic and magnetostatic contributions in the total free energy of nearly zero magnetostrictive amorphous glass-coated nanowires prepared by means of rapid solidification are reported. The comparative study shows that both terms have values of the same order. However, the magnetostatic term is the most important one over a wide range of dimensions, being responsible for the domain structure formation and for the overall magnetic behavior of the investigated nanowires, which mainly consists in the appearance of an axial magnetic bistability. Even in the thinnest samples, the magnetostatic contribution is essential, in spite of an important magnetoelastic one, too. Calculated results agree with the experimental hysteresis loop data. The results are a key for understanding and controlling the magnetization processes in these novel nanowires.
Switching of perpendicular exchange bias in Pt/Co/Pt/α-Cr2O3/Pt layered structure using magneto-electric effect
Authors: Toyoki Kentaro , Shiratsuchi Yu , Kobane Atsushi , Harimoto Shotaro , Onoue Satoshi , Nomura Hikaru , Nakatani Ryoichi
Published: January 2015

Switching of the perpendicular exchange bias polarity using a magneto-electric (ME) effect of α-Cr2O3 was investigated. From the change in the exchange bias field with the electric field during the ME field cooling, i.e., the simultaneous application of both magnetic and electric fields during the cooling, we determined the threshold electric field to switch the perpendicular exchange bias polarity. It was found that the threshold electric field was inversely proportional to the magnetic field indicating that the EH product was constant. The high EH product was required to switch the exchange bias for the film possessing the high exchange anisotropy energy density, which suggests that the energy gain by the ME effect has to overcome the interfacial exchange coupling energy to reverse the interfacial antiferromagnetic spin.
The temperature and electromagnetic field distributions of heat-assisted magnetic recording for bit-patterned media at ultrahigh areal density
Authors: Pituso K. , Kaewrawang A. , Buatong P. , Siritaratiwat A. , Kruesubthaworn A.
Published: January 2015

In this paper, the temperature and electromagnetic field distributions for bit-patterned media (BPM) with heat-assisted writing technology at areal density of 6.54–17.92 Tb/in2 are investigated by the finite integral technique method. We have found that the BPM can confine temperature better than continuous media. The temperature ratio of neighbor bits to heating bit of BPM at areal density of 6.54–7.69 Tb/in2 is lower than 65% and increases with increasing areal density. The electric field direction is toward the bit and the magnetic field circulates around the heating bit. In addition, the electric field of BPM is the same pattern as continuous media at areal density of 13.17 Tb/in2 or above.
The Biopolitical Production of the City: Urban Political Ecology in the Age of Immaterial Labour
Authors: Arboleda Martín
Published: January 2015

This paper explores the potential of immaterial forms of work for a renewed politics of urban metabolisms where the production of emancipatory subjectivity is recast as a crucial moment in the process of making urban space. Through a critical engagement with the works of Michael Hardt and Antonio Negri, it will be argued that their investigations of the current condition of labour provide a powerful toolkit to get a glimpse of the dense, intricate entanglements between human and nonhuman worlds that emerge from science, innovation, affects, arts, and so forth, in the constitution of radical political ecologies. The paper then analyses the case of the struggle for water in Bucaramanga, a city in Colombia threatened by a large-scale mining project, which illustrates how collaborative engagement, communicational strategies, technoscientific debates, and legal action—among others—can produce political solidarities and social subjects that enhance the democratic and socioecological content of contemporary urban worlds.
Impact of Diabetes in Patients with Pulmonary Hypertension
Authors: Abernethy Abraham D. , Stackhouse Kathryn , Hart Stephen , Devendra Ganesh , Bashore Thomas M. , Dweik Raed , Krasuski Richard A.
Published: January 2015

Diabetes complicates management in a number of disease states and adversely impacts survival; how diabetes affects patients with pulmonary hypertension (PH) has not been well characterized. With insulin resistance having recently been demonstrated in PH, we sought to examine the impact of diabetes in these patients. Demographic characteristics, echo data, and invasive hemodynamic data were prospectively collected for 261 patients with PH referred for initial hemodynamic assessment. Diabetes was defined as documented insulin resistance or treatment with antidiabetic medications. Fifty‐five patients (21%) had diabetes, and compared with nondiabetic patients, they were older (mean years ± SD, 61 ± 13 vs. 56 ± 16; P = 0.02), more likely to be black (29% vs. 14%; P = 0.02) and hypertensive (71% vs. 30%; P < 0.001), and had higher mean (±SD) serum creatinine levels (1.1 ± 0.5 vs. 1.0 ± 0.4; P = 0.03). Diabetic patients had similar World Health Organization functional class at presentation but were more likely to have pulmonary venous etiology of PH (24% vs. 10%; P = 0.01). Echo findings, including biventricular function, tricuspid regurgitation, and pressure estimates were similar. Invasive pulmonary pressures and cardiac output were similar, but right atrial pressure was appreciably higher (14 ± 8 mmHg vs. 10 ± 5 mmHg; P < 0.001). Despite similar management, survival was markedly worse and remained so after statistical adjustment. In summary, diabetic patients referred for assessment of PH were more likely to have pulmonary venous disease than nondiabetic patients with PH, with hemodynamics suggesting greater right‐sided diastolic dysfunction. The markedly worse survival in these patients merits further study.
Peripheral Pulmonary Artery Stenosis as a Cause of Pulmonary Hypertension in Adults
Authors: Tonelli Adriano R. , Ahmed Mostafa , Hamed Fadi , Prieto Lourdes R.
Published: January 2015

Peripheral pulmonary artery stenosis (PPAS) is an underrecognized condition in the adult population. PPAS can lead to pulmonary hypertension but is likely misdiagnosed as either idiopathic pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension. We retrospectively identified adult patients with PPAS either in its isolated form or related to other congenital defects from January 1998 to September 2012. We reviewed the patients’ clinical data by using our hospital electronic medical records and/or their paper charts. We identified 6 adult patients with PPAS with an age range of 16–56 years (1 woman and the rest men). Presenting signs and symptoms were thoracic murmurs, progressive dyspnea, and syncope. Three patients had Williams‐Beuren syndrome. Pulmonary angiography showed that PPAS was predominantly located in main branches or lobar pulmonary arteries in 5 patients, while in 1 patient the arterial narrowing was at the level of the segmental pulmonary arteries. Right heart catheterization showed a mean pulmonary artery pressure (PAP) ranging from 35 to 60 mmHg. Balloon dilation was performed in all patients, predominantly in the lobar arteries, and it caused a decrease in mean PAP that ranged from 16% to 46% in 5 patients. In 1 patient the mean PAP did not decrease. All but 1 patient had follow‐up echocardiograms at 1 year that showed stable echocardiographic findings. Pulmonary hypertension due to PPAS continues to presents a diagnostic challenge. Therefore, a high index of suspicion during the initial evaluation of pulmonary hypertension is essential for its prompt diagnosis and adequate treatment.
Factorial growth rates for the number of hyperbolic 3-manifolds of a given volume
Authors: Millichap Christian
Published: January 2015

The work of Jørgensen and Thurston shows that there is a finite number

N
(
v
)

N(v)

of orientable hyperbolic

3
3

-manifolds with any given volume

v
v

. In this paper, we construct examples showing that the number of hyperbolic knot complements with a given volume

v
v

can grow at least factorially fast with

v
v

. A similar statement holds for closed hyperbolic

3
3

-manifolds, obtained via Dehn surgery. Furthermore, we give explicit estimates for lower bounds of

N
(
v
)

N(v)

in terms of

v
v

for these examples. These results improve upon the work of Hodgson and Masai, which describes examples that grow exponentially fast with

v
v

. Our constructions rely on performing volume preserving mutations along Conway spheres and on the classification of Montesinos knots.
Adeno‐Associated Virus Vector–Based Gene Therapy for Monogenetic Metabolic Diseases of the Liver
Authors: Junge Norman , Mingozzi Federico , Ott Michael , Baumann Ulrich
Published: January 2015

Liver‐based metabolic diseases account for a substantial burden of childhood diseases. In most patients, treatment is often limited to supportive measures and liver transplantation is ultimately required. Even despite the excellent long‐term outcome of liver transplantation, the procedure is associated with a significant morbidity and mortality. Gene therapy, in contrast, has great potential to save lives, improve the quality of life, and offer few risks and adverse effects compared with present therapies including liver transplantation. The most promising results to date in liver gene transfer have been achieved with adeno‐associated virus. Although safety issues, such as immunogenicity of vector and/or transgene product, remain an important concern, gene therapy is ready for clinical trials in adults and adolescents. Developing and testing safe approaches for efficient and long‐term stable applications in newborns and small children, such as targeted integration and gene correction, is one of the remaining future challenges.
Elizabethkingia meningoseptica: an unusual cause for septicaemia
Authors: Swain Bichitrananda , Rout Subhrajita , Otta Sarita , Rakshit Anindita
Published: January 2015

Introduction:

Elizabethkingia meningoseptica, a Gram‐negative non‐fermenting bacterium, is usually associated with neonatal meningitis and other infections, especially in immunocompromised patients. It is a potential nosocomial pathogen and is usually resistant to several commonly used antimicrobials.

Case presentation:

We here report a rare case of septicaemia caused by E. meningoseptica associated with peritonitis and choledocholithiasis. The patient succumbed in spite of diagnosis and institution of appropriate antibiotics.

Conclusion:

A prompt diagnosis of infection with E. meningoseptica is important so as to guide the institution of appropriate antibiotic treatment.
Phylogenetically distinct equine influenza viruses show different tropism for the swine respiratory tract
Authors: Patrono Livia V. , Bonfante Francesco , Zanardello Claudia , Terregino Calogero , Capua Ilaria , Murcia Pablo R.
Published: January 2015

Influenza A viruses circulate in a wide range of animals. H3N8 equine influenza virus (EIV) is an avian-origin virus that has established in dogs as canine influenza virus (CIV) and has also been isolated from camels and pigs. Previous work suggests that mutations acquired during EIV evolution might have played a role in CIV emergence. Given the potential role of pigs as a source of human infections, we determined the ability of H3N8 EIVs to replicate in pig cell lines and in respiratory explants. We show that phylogenetically distinct EIVs display different infection phenotypes along the pig respiratory tract, but not in cell lines. Our results suggest that EIV displays a dynamic host range along its evolutionary history, supporting the view that evolutionary processes play important roles in host range and tropism and also underscoring the utility of using explant cultures to study influenza pathogenesis.
Hippocampus, perirhinal cortex, and complex visual discriminations in rats and humans
Authors: Hales Jena B. , Broadbent Nicola J. , Velu Priya D. , Squire Larry R. , Clark Robert E.
Published: January 2015

Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Notably, rats with hippocampal lesions exhibited the same impairment. Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. Both lesion groups were able to acquire visual discriminations involving the same objects used in the oddity task. Patients with hippocampal damage or larger medial temporal lobe lesions were intact in a similar oddity task that allowed participants to explore objects quickly using eye movements. We suggest that humans were able to rely on an intact working memory capacity to perform this task, whereas rats (who moved slowly among the objects) needed to rely on long-term memory.
Handling alters aggression and “loser” effect formation inDrosophila melanogaster
Authors: Trannoy Severine , Chowdhury Budhaditya , Kravitz Edward A.
Published: January 2015

InDrosophila, prior fighting experience influences the outcome of later contests: losing a fight increases the probability of losing second contests, thereby revealing “loser” effects that involve learning and memory. In these experiments, to generate and quantify the behavioral changes observed as consequences of losing fights, we developed a new behavioral arena that eliminates handling. We compared two commonly used fly handling procedures with this new chamber and demonstrated that handling influences aggressive behavior and prevents “loser” effect formation. In addition, we induced and observed novel aspects of learning associated with aggression such as the formation of robust winner effects.
Regionally selective requirement for D1/D5 dopaminergic neurotransmission in the medial prefrontal cortex in object-in-place associative recognition memory
Authors: Savalli Giorgia , Bashir Zafar I. , Warburton E. Clea
Published: January 2015

Object-in-place (OiP) memory is critical for remembering the location in which an object was last encountered and depends conjointly on the medial prefrontal cortex, perirhinal cortex, and hippocampus. Here we examined the role of dopamine D1/D5 receptor neurotransmission within these brain regions for OiP memory. Bilateral infusion of D1/D5 receptor antagonists SCH23390 or SKF83566 into the medial prefrontal cortex, prior to memory acquisition, impaired OiP performance following a 5 min or 1 h delay. Retrieval was unaffected. Intraperirhinal or intrahippocampal infusions of SCH23390 had no effect. These results reveal a selective role for D1/D5 receptors in the mPFC during OiP memory encoding.
Methyl-CpG-Binding Domain Protein MBD7 Is Required for Active DNA Demethylation in Arabidopsis
Authors: Wang Chunlei , Dong Xiaomei , Jin Dan , Zhao Yusheng , Xie Shaojun , Li Xiaojie , He Xinjian , Lang Zhaobo , Lai Jinsheng , Zhu Jian-Kang , Gong Zhizhong
Published: January 2015

Although researchers have established that DNA methylation and active demethylation are dynamically regulated in plant cells, the molecular mechanism for the regulation of active DNA demethylation is not well understood. By using an Arabidopsis (Arabidopsis thaliana) line expressing the Promoter RESPONSIVE TO DEHYDRATION 29A:LUCIFERASE (ProRD29A:LUC) and Promoter cauliflower mosaic virus 35S:NEOMYCIN PHOSPHOTRANSFERASE II (Pro35S:NPTII) transgenes, we isolated an mbd7 (for methyl-CpG-binding domain protein7) mutant. The mbd7 mutation causes an inactivation of the Pro35S:NPTII transgene but does not affect the expression of the ProRD29A:LUC transgene. The silencing of the Pro35S:NPTII reporter gene is associated with DNA hypermethylation of the reporter gene. MBD7 interacts physically with REPRESSOR OF SILENCING5/INCREASED DNA METHYLATION2, a protein in the small heat shock protein family. MBD7 prefers to target the genomic loci with high densities of DNA methylation around chromocenters. The Gypsy-type long terminal repeat retrotransposons mainly distributed around chromocenters are most affected by mbd7 in all transposons. Our results suggest that MBD7 is required for active DNA demethylation and antisilencing of the genomic loci with high densities of DNA methylation in Arabidopsis.
Twofac-tricarbonylrhenium(I) azadipyrromethene (ADPM) complexes: ligand-substitution effect on crystal structure
Authors: Cibian Mihaela , Bessette André , O'Connor Andrew , Ferreira Janaina G. , Hanan Garry S.
Published: January 2015

The crystal structures offac-(acetonitrile-κN)(2-{[3,5-bis(4-methoxyphenyl)-2H-pyrrol-2-ylidene-κN1]amino}-3,5-bis(4-methoxyphenyl)-1H-pyrrol-1-ido-κN1)tricarbonylrhenium(I)–hexane–acetonitrile (2/1/2), [Re(C36H30N3O4)(CH3CN)(CO)3]·0.5C6H14·CH3CN, (2), andfac-(2-{[3,5-bis(4-methoxyphenyl)-2H-pyrrol-2-ylidene-κN1]amino}-3,5-bis(4-methoxyphenyl)-1H-pyrrol-1-ido-κN1)tricarbonyl(dimethyl sulfoxide-κO)rhenium(I), [Re(C36H30N3O4)(C2H6OS)(CO)3], (3), at 150 K are reported. Both complexes display a distorted octahedral geometry, with afac-Re(CO)3arrangement and one azadipyrromethene (ADPM) chelating ligand in the equatorial position. One solvent molecule completes the coordination sphere of the ReIcentre in the remaining axial position. The ADPM ligand shows high flexibility upon coordination, while retaining its π-delocalized nature. Bond length and angle analyses indicate that the differences in the geometry around the ReIcentre in (2) and (3), and those found in three reportedfac-Re(CO)3–ADPM complexes, are dictated mainly by steric factors and crystal packing. Both structures display intramolecular C—H...N hydrogen bonding. Intermolecular interactions of the Csp2—H...π and Csp2—H...O(carbonyl) types link the discrete monomers into extended chains.
Mononuclear and three-dimensional metal complexes based on a multidentate hydrazone ligand
Authors: Liu Yan-Fei , Liu Ya-Ping , Zhang Ke-Ke , Ren Qing-Ling , Qin Jie
Published: January 2015

A potentially pentadentate hydrazone ligand,N′-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazide (HL), was prepared from the condensation reaction of nicotinohydrazide and acetylpyrazine. Reactions of HLwith MnCl2, Mn(CH3COO)2and Cd(CH3COO)2afforded three metal complexes, namely dichlorido{N′-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazide-κ2N′,O}manganese(II), [MnCl2(C12H11N5O)], (I), bis{N′-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N′,O]manganese(II), [Mn(C12H10N5O)2], (II), and poly[[(acetato-κ2O,O′){μ3-N′-[1-(pyrazin-2-yl-κ2N1:N4)ethylidene]nicotinohydrazidato-κ3N′,O:N1}cadmium(II)] chloroform disolvate], {[Cd(C12H10N5O)(CH3COO)]·2CHCl3}n, (III), respectively. Complex (I) has a mononuclear structure, the MnIIcentre adopting a distorted square-pyramidal coordination. Complex (II) also has a mononuclear structure, with the MnIIcentre occupying a special position (C2symmetry) and adopting a distorted octahedral coordination environment, which is defined by two O atoms and four N atoms from twoN′-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazidate (L−) ligands relatedviaa crystallographic twofold axis. Complex (III) features a unique three-dimensional network with rectangular channels, and theL−ligand also serves as a counter-anion. The coordination geometry of the CdIIcentre is pentagonal bipyramidal. This study demonstrates that HL, which can act as either a neutral or a mono-anionic ligand, is useful in the construction of interesting metal–organic compounds.
Crystal structure of methylN-ferrocenylcarbamate
Authors: Rodríguez Alan J. , Quirke J. Martin. E. , Diouf Aida O.
Published: January 2015

The asymmetric unit of the title compound, [Fe(C5H5)(C7H8NO2)], contains two independent molecules consisting of a ferrocenyl moiety and a nitrogen-bound methyl carbamate. These units are almost perpendicular to each other, making dihedral angles of 87.74 (9) and 87.32 (8)°. In each independent molecule, the cyclopentadienyl rings deviate slightly from an eclipsed conformation and lie virtually parallel [dihedral angles = 1.42 (15) and 0.49 (13)°]. In the crystal, molecules are linked by N—H...O hydrogen bonds into chains along thea-axis direction.
Crystal structure of 3-benzoyl-2-[(5-bromo-2-hydroxy-3-methoxybenzylidene)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene
Authors: Kaur Manpreet , Jasinski Jerry P. , Yathirajan H. S. , Glidewell Christopher , Byrappa K.
Published: January 2015

In the cyclohexene ring of the title compound, C23H20BrNO3S, the –(CH2)4– atoms are positionally disordered [occupancy ratio = 0.753 (6):0.247 (6)]. The ring has a half-chair conformation for both the major and minor components. The dihedral angles between the mean plane of the thiophene ring and those of the benzene and phenyl rings are 35.2 (4) and 57.7 (3)°, respectively. The planes of the two aryl rings are twisted with respect to each other by 86.4 (6)°. In the molecule, there is an O—H...N hydrogen bond forming anS(6) ring motif. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming chains parallel to [100].
Crystal structure of chlorido(5,10,15,20-tetraphenylporphyrinato-κ4N)manganese(III) 2-aminopyridine disolvate
Authors: Harhouri Wafa , Dhifaoui Salma , Najmudin Shabir , Bonifácio Cecilia , Nasri Habib
Published: January 2015

In the title compound, [Mn(C44H28N4)Cl]·2C5H6N2, the MnIIIcentre is coordinated by four pyrrole N atoms [averaged Mn—N = 2.012 (4) Å] of the tetraphenylporphyrin molecule and one chloride axial ligand [Mn—Cl = 2.4315 (7) Å] in a square-pyramidal geometry. The porphyrin macrocycle exhibits a non-planar conformation with majorrufflingandsaddlingdistortions. In the crystal, two independent solvent molecules form dimers through N—H...N hydrogen bonding. In these dimers, one amino N atom has a short Mn...N contact of 2.642 (1) Å thus completing the Mn environment in the form of a distorted octahedron, and another amino atom generates weak N—H...Cl hydrogen bonds, which link further all molecules into chains along theaaxis.
Crystal structure of (E)-1-([1,1′-biphenyl]-4-yl)-3-(3-nitrophenyl)prop-2-en-1-one
Authors: Shanthi D. , Vidhyasagar T. , Rajeswari K. , Kayalvizhi M. , Vasuki G. , Thiruvalluvar A.
Published: January 2015

In the title compound, C21H15NO3, the molecule has anEconformation about the C=C bond, and the C—C=C—C torsion angle is −178.24 (18)°. In the molecule, the planes of the terminal rings are twisted by an angle of 42.19 (10)°, while the biphenyl part is not planar, with a dihedral angle between the rings of 39.2 (1)°. The dihedral angle between the nitrophenyl ring and the inner benzene ring is 5.56 (9)°. The 3-nitro group is approximately coplanar with the benzene ring to which it is attached [O—N—C—C = 0.1 (3)°]. In the crystal, molecules are linkedviaC—H...π interactions, involving the terminal benzene rings, forming corrugated layers parallel to (100).
Crystal structure oftrans-(1,8-dibutyl-1,3,6,8,10,13-hexaazacyclotetradecane-κ4N3,N6,N10,N13)bis(5-methyltetrazolato-κN)nickel(II) from synchrotron data
Authors: Kim Dae-Woong , Shin Jong Won , Kim Jin Hong , Moon Dohyun
Published: January 2015

The structure of the title compound, [Ni(C2H3N4)2(C16H38N6)], has been characterized from synchrotron radiation. The asymmetric unit consists of one half of the NiIIcomplex molecule, which is related to the other half-molecule by an inversion center. The NiIIion is coordinated by four secondary N atoms of the macrocyclic ligand in a square-planar fashion in the equatorial plane and by two N atoms of the 5-methyltetrazolate anions in axial positions, resulting in a tetragonally distorted octahedral geometry. The average equatorial Ni—N bond length [2.060 (8) Å] is shorter than the axial Ni—N bond length [2.2183 (11) Å]. An intramolecular N—H...N hydrogen bond between the secondary amine N atom of the macrocyclic ligand and the non-coordinating N atom of the 5-methyltetrazolate ion stabilizes the molecular structure. Moreover, an intermolecular N—H...N hydrogen bond between the macrocyclic ligand and 5-methyltetrazolate group gives rise to a supramolecular sheet structure parallel to thebcplane.
Crystal structures of crotonaldehyde semicarbazone and crotonaldehyde thiosemicarbazone from X-ray powder diffraction data
Authors: Arfan Atef , Rukiah Mwaffak
Published: January 2015

Crotonaldehyde semicarbazone {systematic name: (E)-2-[(E)-but-2-en-1-ylidene]hydrazinecarboxamide}, C5H9N3O, (I), and crotonaldehyde thiosemicarbazone {systematic name: (E)-2-[(E)-but-2-en-1-yldene]hydrazinecarbothioamide}, C5H9N3S, (II), show the sameEconformation around the imine C=N bond. Compounds (I) and (II) were obtained by the condensation of crotonaldehyde with semicarbazide hydrochloride and thiosemicarbazide, respectively. Each molecule has an intramolecular N—H...N hydrogen bond, which generates anS(5) ring. In (I), the crotonaldehyde fragment is twisted by 2.59 (5)° from the semicarbazide mean plane, while in (II) the corresponding angle (with the thiosemicarbazide mean plane) is 9.12 (5)°. The crystal packing is different in the two compounds: in (I) intermolecular N—H...O hydrogen bonds link the molecules into layers parallel to thebcplane, while weak intermolecular N—H...S hydrogen bonds in (II) link the molecules into chains propagating in [110].
Crystal structure of 2,2′-oxybis(4-methylquinoline)
Authors: Tilborg Anaelle
Published: January 2015

The title compound, C20H16N2O, (I), has been unwittingly obtained from the slow evaporation of a saturated solution of commercial benserazide hydrochloride [benserazide, (II), being one of the principal therapeutic compounds used for the management of Parkinson's disease, mostly used in combination with levodopa]. The molecule of (I) is composed of two planar 4-methylquinoline aromatic moieties [maximum deviations of 0.0104 (18) and 0.016 (2) Å], almost perpendicular to each other [dihedral angle = 89.5 (2)°], bridged by an O atom. The supramolecular organization consists of a π-bonded chain, resulting from the stacking of molecules related by inversion centres located along direction [111].
The joint effect of board characteristics on financial performance
Authors: Wahba Hayam
Published: January 2015

Purpose

– This paper aims to investigate the joint effect of board characteristics on financial performance. Most of the existing literature implicitly assumes that the relationship between either board composition, or board leadership structure and financial performance is direct.

Design/methodology/approach

– The generalized least squares method was performed as a panel data analysis on a sample of 40 Egyptian listed firms during the period from 2008 to 2010.

Findings

– The results demonstrated that under board leadership structure that assigns the duties of the CEO and chairman to the same person, increasing the proportion of non-executive members to the total number of directors has a negative impact on firm financial performance.

Practical implications

– First, corporate governance structures do not operate in a vacuum, and therefore, corporate governance mechanisms must be considered and assessed altogether. Second, failure to understand the underlying interdependency among corporate governance mechanisms may result in arguments that blame some corporate governance designs for poor financial performance. Third, there is no single board governance mechanism that can be considered ideal, but there are combinations of these mechanisms that are preferred.

Originality/value

– The paper adds to the corporate governance literature by providing empirical evidence from the emerging market of Egypt. The evidence shows that the relationship between board characteristics and financial performance is not a monotonic relationship. Consequently, these findings imply that existing evidence explaining the relationship between board characteristics and financial performance needs to be interpreted with some caution.
The role of shell/core saturation level on the accuracy and mechanical characteristics of porous calcium phosphate models produced by 3Dprinting
Authors: Castilho Miguel , Gouveia Barbara , Pires Inês , Rodrigues Jorge , Pereira Manuel
Published: January 2015

Purpose

– This paper aims to study the influence of the binder saturation level on the accuracy and on the mechanical properties of three-dimensional (3D)-printed scaffolds for bone tissue engineering.

Design/methodology/approach

– To study the influence of the liquid binder volume on the models accuracy, two quality test plates with different macropore sizes were designed and produced. For the mechanical and physical characterisation, cylindrical specimens were used. The models were printed using a calcium phosphate powder, which was characterised in terms of composition, particle size and morphology, by X-ray diffraction (XRD), laser diffraction and Scanning electron microscopy (SEM) analysis. The sample’s physical characterisation was made using the Archimedes method (porosity), SEM, micro-computer tomography (CT) and digital scan techniques, while the mechanical characterisation was performed by means of uniaxial compressive tests. Strength distribution was analysed using a statistical Weibull approach, and the dependence of the compressive strength on the porosity was discussed.

Findings

– The saturation level is determinant for the structural characteristics, accuracy and strength the models produced by three-dimensional printing (3DP). Samples printed with the highest saturation showed higher compressive strengths (24 MPa), which are over the human trabecular bone. The models printed with lower saturations presented the highest accuracy and pore interconnectivity.

Originality/value

– This study allowed to acquire important knowledge concerning the effects of shell/core saturation on the overall performance of the 3DP. With this information it is possible to devise scaffolds with the required properties for bone scaffold engineering.
Additive manufacturing under pressure
Authors: Jones Jason B. , Wimpenny David I. , Gibbons Greg J
Published: January 2015

Purpose

– This paper aims to investigate the effects on material properties of layer-by-layer application of pressure during fabrication of polymeric parts by additive manufacturing (AM). Although AM, also known popularly as 3D printing, has set a new standard for ease of use and minimal restraint on geometric complexity, the mechanical part properties do not generally compare with conventional manufacturing processes. Contrary to other types of polymer processing, AM systems do not normally use (in-process) pressure during part consolidation.

Design/methodology/approach

– Tensile specimens were produced in Somos 201 using conventional laser sintering (LS) and selective laser printing (SLP) – a process under development in the UK, which incorporates the use of pressure to assist layer consolidation.

Findings

– Mechanical testing demonstrated the potential to additively manufacture parts with significantly improved microstructure and mechanical properties which match or exceed conventional processing. For example, the average elongation at break and ultimate tensile strength of a conventionally laser-sintered thermoplastic elastomer (Somos 201) increased from 136 ± 28 per cent and 4.9 ± 0.4 MPa, to 513 ± 35 per cent and 10.4 ± 0.4 MPa, respectively, when each layer was fused with in-process application of pressure (126 ± 9 kPa) by SLP.

Research limitations/implications

– These results are based on relatively small sample size, but despite this, the trends observed are of significant importance to the elimination of voids and porosity in polymeric parts.

Practical implications

– Layerwise application of pressure should be investigated further for defect elimination in AM.

Originality/value

– This is the first study on the effects of layerwise application of pressure in combination with area-wide fusing.
Comparing environmental impacts of additive manufacturing vs traditional machining via life-cycle assessment
Authors: Faludi Jeremy , Bayley Cindy , Bhogal Suraj , Iribarne Myles
Published: January 2015

Purpose

– The purpose of this study is to compare the environmental impacts of two additive manufacturing machines to a traditional computer numerical control (CNC) milling machine to determine which method is the most sustainable.

Design/methodology/approach

– A life-cycle assessment (LCA) was performed, comparing a Haas VF0 CNC mill to two methods of additive manufacturing: a Dimension 1200BST FDM and an Objet Connex 350 “inkjet”/“polyjet”. The LCA’s functional unit was the manufacturing of two specific parts in acrylonitrile butadiene styrene (ABS) plastic or similar polymer, as required by the machines. The scope was cradle to grave, including embodied impacts, transportation, energy used during manufacturing, energy used while idling and in standby, material used in final parts, waste material generated, cutting fluid for CNC, and disposal. Several scenarios were considered, all scored using the ReCiPe Endpoint H and IMPACT 2002+ methodologies.

Findings

– Results showed that the sustainability of additive manufacturing vs CNC machining depends primarily on the per cent utilization of each machine. Higher utilization both reduces idling energy use and amortizes the embodied impacts of each machine. For both three-dimensional (3D) printers, electricity use is always the dominant impact, but for CNC at maximum utilization, material waste became dominant, and cutting fluid was roughly on par with electricity use. At both high and low utilization, the fused deposition modeling (FDM) machine had the lowest ecological impacts per part. The inkjet machine sometimes performed better and sometimes worse than CNC, depending on idle time/energy and on process parameters.

Research limitations/implications

– The study only compared additive manufacturing in plastic, and did not include other additive manufacturing technologies, such as selective laser sintering or stereolithography. It also does not include post-processing that might bring the surface finish of FDM parts up to the quality of inkjet or CNC parts.

Practical implications

– Designers and engineers seeking to minimize the environmental impacts of their prototypes should share high-utilization machines, and are advised to use FDM machines over CNC mills or polyjet machines if they provide sufficient quality of surface finish.

Originality/value

– This is the first paper quantitatively comparing the environmental impacts of additive manufacturing with traditional machining. It also provides a more comprehensive measurement of environmental impacts than most studies of either milling or additive manufacturing alone – it includes not merely CO2 emissions or waste but also acidification, eutrophication, human toxicity, ecotoxicity and other impact categories. Designers, engineers and job shop managers may use the results to guide sourcing or purchasing decisions related to rapid prototyping.
Optimisation of process parameters for lattice structures
Authors: Abele Eberhard , Stoffregen Hanns A. , Klimkeit Klaus , Hoche Holger , Oechsner Matthias
Published: January 2015

Purpose

– This paper aims to develop a set of process parameters tailored for lattice structures and test them against standard process (SP) parameters. Selective laser melting (SLM) is a commonly known and established additive manufacturing technique and is a key technology in generating intricately shaped lattice structures. However, SP parameters used in this technology have building time and accuracy disadvantages for structures with a low area-to-perimeter ratio, such as thin struts.

Design/methodology/approach

– In this research work, body-centred cubic structure specimens are manufactured using adapted process parameters. Central to the adapted process parameters is the positioning of the laser beam, the scan strategy and the linear energy density. The specimens are analysed with X-ray micro-computed tomography for dimensional accuracy. The final assessment is a comparison between specimens manufactured using adapted process parameters and those using SP parameters.

Findings

– Standard parameters for lattice structures lead to a significant shift from the nominal geometry. An extensive manufacturing and computation time due to several exposure patterns (e.g. pre-contours, post-contours) was observed. The tailored process parameters developed had good dimensional accuracy, reproducible results and improved manufacturing performance.

Research limitations/implications

– The results are based on a distinctive geometry of the lattice structure and a specific material. Future research should be extended to other geometries and materials.

Practical implications

– Optimisation of process parameters for the part geometry is a critical factor in improving dimensional accuracy and performance of SLM processes.

Originality/value

– This study demonstrates how application-tailored process parameters can lead to superior performance and improved dimensional accuracy. The results can be transferred to other lattice structure designs and materials.
Design and fabrication of an aircraft static aeroelastic model based on rapid prototyping
Authors: Wang Chao , Yin Guofu , Zhang Zhengyu , Wang Shuiliang , Zhao Tao , Sun Yan , Yang Dangguo
Published: January 2015

Purpose

– The purpose of this paper is to introduce a novel method for developing static aeroelastic models based on rapid prototyping for wind tunnel testing.

Design/methodology/approach

– A metal frame and resin covers are applied to a static aeroelastic wind tunnel model, which uses the difference of metal and resin to achieve desired stiffness distribution by the stiffness similarity principle. The metal frame is made by traditional machining, and resin covers are formed by stereolithgraphy. As demonstrated by wind tunnel testing and stiffness measurement, the novel method of design and fabrication of the static aeroelastic model based on stereolithgraphy is practical and feasible, and, compared with that of the traditional static elastic model, is prospective due to its lower costs and shorter period for its design and production, as well as avoiding additional stiffness caused by outer filler.

Findings

– This method for developing static aeroelastic wind tunnel model with a metal frame and resin covers is feasible, especially for aeroelastic wind tunnel models with complex external aerodynamic shape, which could be accurately constructed based on rapid prototypes in a shorter time with a much lower cost. The developed static aeroelastic aircraft model with a high aspect ratio shows its stiffness distribution in agreement with the design goals, and it is kept in a good condition through the wind tunnel testing at a Mach number ranging from 0.4 to 0.65.

Research limitations/implications

– The contact stiffness between the metal frame and resin covers is difficult to calculate accurately even by using finite element analysis; in addition, the manufacturing errors have some effects on the stiffness distribution of aeroelastic models, especially for small-size models.

Originality/value

– The design, fabrication and ground testing of aircraft static aeroelastic models presented here provide accurate stiffness and shape stimulation in a cheaper and sooner way compared with that of traditional aeroelastic models. The ground stiffness measurement uses the photogrammetry, which can provide quick, and precise, evaluation of the actual stiffness distribution of a static aeroelastic model. This study, therefore, expands the applications of rapid prototyping on wind tunnel model fabrication, especially for the practical static aeroelastic wind tunnel tests.
Image‐warping waveform tomography
Authors: Perrone Francesco , Sava Paul
Published: January 2015

Imaging the change in physical parameters in the subsurface requires an estimate of the long wavelength components of the same parameters in order to reconstruct the kinematics of the waves propagating in the subsurface. One can reconstruct the model by matching the recorded data with modeled waveforms extrapolated in a trial model of the medium. Alternatively, assuming a trial model, one can obtain a set of images of the reflectors from a number of seismic experiments and match the locations of the imaged interfaces. Apparent displacements between migrated images contain information about the velocity model and can be used for velocity analysis. A number of methods are available to characterize the displacement between images; in this paper, we compare shot‐domain differential semblance (image difference), penalized local correlations, and image‐warping. We show that the image‐warping vector field is a more reliable tool for estimating displacements between migrated images and leads to a more robust velocity analysis procedure. By using image‐warping, we can redefine the differential semblance optimization problem with an objective function that is more robust against cycle‐skipping than the direct image difference. We propose an approach that has straightforward implementation and reduced computational cost compared with the conventional adjoint‐state method calculations. We also discuss the weakness of migration velocity analysis in the migrated‐shot domain in the case of highly refractive media, when the Born modelling operator is far from being unitary and thus its adjoint (migration) operator poorly approximates the inverse.
Inorganic fungicides as routinely applied in organic and conventional agriculture can increase palatability but reduce microbial decomposition of leaf litter
Authors: Zubrod Jochen P. , Feckler Alexander , Englert Dominic , Koksharova Natalia , Rosenfeldt Ricki R. , Seitz Frank , Schulz Ralf , Bundschuh Mirco
Published: January 2015

The application of fungicides is considered an indispensable measure to secure crop production. These substances, however, may unintentionally enter surface waters via run‐off, potentially affecting the microbial community. To assess such risks adequately, authorities recently called for suitable test designs involving relevant aquatic micro‐organisms.

We assessed the structural and functional responses of leaf‐associated microbial communities, which play a key role in the breakdown of allochthonous leaf material in streams, towards the inorganic fungicides copper (Cu) and elemental sulphur (S). These substances are of particular interest as they are authorized for both conventional and organic farming in many countries of the world. We used the food choice of the amphipod shredder Gammarus fossarum (indicative for micro‐organism‐mediated leaf palatability) as well as microbial leaf decomposition as functional endpoints. Moreover, the leaf‐associated microbial communities were characterized by means of bacterial density, fungal biomass and community composition facilitating mechanistic understanding of the observed functional effects.

While Gammarus preferred Cu‐exposed leaves over unexposed ones, microbial leaf decomposition was reduced by both Cu and S (up to 30%). Furthermore, Cu exposure decreased bacterial densities (up to 60%), stimulated the growth of leaf‐associated fungi (up to 100%) and altered fungal community composition, while S did not affect any of the assessed structural endpoints.

Synthesis and applications. We observed both structural and functional changes in leaf‐associated microbial communities at inorganic fungicide concentrations realistic for surface water bodies influenced by conventional and organic farming. Our data hence justify a careful re‐evaluation of the environmental safety of the agricultural use of these compounds. Moreover, inclusion of an experimental design similar to the one used in this study in lower tier environmental risk assessments of antimicrobial compounds may aid to safeguard the integrity of aquatic microbial communities and the functions they provide.
Intensive multi‐family therapy for adolescent anorexia nervosa: adolescents’ and parents’ day‐to‐day experiences
Authors: Voriadaki Tatiana , Simic Mima , Espie Jonathan , Eisler Ivan
Published: January 2015

The experiences of six families involved in a 4‐day multi‐family therapy (MFT) group for adolescent anorexia nervosa were examined day by day. Participants completed daily records (journals and rating scales) of their experiences. Parents completed the parents versus anorexia scale pretreatment and post‐treatment. The researcher kept an observation journal of the MFT process. A week post‐treatment, adolescents and parents took part in separate focus groups. The participants’ insights into the illness increased rapidly from Day 1 to 3, while participants’ emotions fluctuated throughout the 4 days. Motivation for recovery was enhanced for four of the five adolescents and self‐efficacy improved for seven of 10 parents. In addition, some improvement in intra‐family communication was reported in five of six families. Change was facilitated by the sharing of experiences with other families in a similar situation, role play activities, the increased ability to express emotions and the perceived mutual learning and support.

Practitioner points

Sharing of experiences in intensive MFT for AN can help improve insight into the disorder and instill hope

Parents becoming ‘firm’ as well as supportive with eating may be the most useful practical strategy

Role plays can help increase empathy, motivation and mobilize families for action

Open expression of feelings works positively, promotes cohesiveness in the group even when this includes difficult emotions

MFT treatment context can be experienced as challenging but nevertheless supportive