bluuebunny/crossref_metadata_2025 huggingface dataset:
The Ambient Temperature Effect on Current-Voltage Characteristics of Surface-Passivated GaN-Based Field-Effect Transistors
Authors: Liu W.L. , Turin V.O. , Balandin A.A. , Chen Y.L. , Wang K.L.
Published: August 2016

We have studied experimentally the effect of ambient temperature on performance of the surface-passivated Al0.2Ga0.8N/GaN heterostructure field-effect transistors in the temperature range from 25°C to 250°C. The measured data have been compared with physics-based modeling of the GaN transistor characteristics under different ambient temperatures. The experimental data, showing about 33% degradation in the saturation current with a temperature increase from 25°C to 250°C, agrees well with the results of simulations performed using ISE DESSIS software. Obtained results and analytical extrapolations can be used for predicting device performance in changing environments, as well as for optimization of the device structure.
Growth and Device Performance of GaN Schottky Rectifiers
Authors: Chyi Jen-Inn , Lee C. -M. , Chuo C.C. , Chi G. C. , Dang G. T. , Zhang A. P. , Ren Fan , Cao X.A. , Pearton S.J. , Chu S. N. G. , Wilson R. G.
Published: August 2016

Undoped, 4µm thick GaN layers grown by Metal Organic Chemical Vapor Deposition were used for fabrication of high stand off voltage (356 V) Schottky diode rectifiers. The figure of merit VRB2/RON, where VRB is the reverse breakdown voltage and RON is the on-resistance, was ~ 4.53 MW-cm−2 at 25°C. The reverse breakdown voltage displayed a negative temperature coefficient, due to an increase in carrier concentration with increasing temperature. Secondary Ion Mass Spectrometry measurements showed that Si and O were the most predominant electrically active impurities present in the GaN.
New plasma chemistries for etching GaN and InN: BI3 and BBr3
Authors: Cho Hyun , Hong J. , Maeda T. , Donovan S.M. , Devin MacKenzie J. , Abernathy Cammy R. , Pearton S.J. , Shul R. J. , Han J.
Published: August 2016

Smooth, anisotropic etching of InN and GaN is obtained in BI3- or BBr3-based Inductively Coupled Plasmas. Etch selectivities of 100:1 were achieved for InN over both GaN and AlN in the BI3 mixtures, while for BBr3 discharges values of 100:1 for InN over AlN and 25:1 for InN over GaN were measured. The etched surface morphologies of InN and GaN with both mixtures are similar or better than those of control samples.
Fabrication and Characterization of GaN/AlGaN Ultraviolet-Band Heterojunction Photodiodes
Authors: Krishnankutty Subash , Yang Wei , Nohava Thomas , Ruden P. Paul
Published: August 2016

Results from MOCVD grown n-Al0.1Ga0.9N/i-GaN/p-GaN UV photodetectors on sapphire substrates are presented. The devices show peak responsivities near 0.2A/W for wavelengths between 352nm and 362nm, and responsivities of less than 10-3A/W for wavelengths longer than 375nm and shorter than 342nm. The data is explained in terms of a simple device model.
Time of Flight Mass Spectroscopy of Recoiled Ions Studies of Gallium Nitride Thin Film Deposition by Various Molecular Beam Epitaxial Methods
Authors: Kim E. , Berichev I. , Bensaoula A. , Schultz A. , Waters K. , Zagozdzon-Wosik W.
Published: August 2016

Gallium Nitride (GaN) thin films were successfully grown by electron cyclotron resonance molecular beam epitaxy (ECR-MBE), gas source MBE (GSMBE), and chemical beam epitaxy (CBE). Time of flight mass spectroscopy of recoiled ions (TOF-MSRI) and reflection high energy electron diffraction (RHEED) were used in-situ to determine the surface composition, crystalline structure, and growth mode of GaN thin films deposited by the three MBE methods. The substrate nitridation and the buffer layers were monitored and optimized by TOF-MSRI and RHEED. For GSMBE, the gallium to nitrogen ratio is found to correlate well with ex-situ optical properties. In the case of CBE, carbon incorporation determines the surface morphology, crystalline quality and optical activity of the epilayers.
AMMONO method of BN, AlN and GaN synthesis and crystal growth.
Authors: Dwili˜ski R. , Doradzi˜ski R. , Garczy˜ski J. , Sierzputowski L. , Palczewska M. , Wysmolek Andrzej , Kami˜ska M.
Published: August 2016

Microcrystals of BN, AlN and GaN were obtained by the AMMONO method, in which nitridization of metal occurs in supercritical ammonia, at relatively low temperature and pressure conditions (below 550°C and 5 kbar). The reaction rate was regulated by the amount of mineralizers, i.e. alkali metal amides.

All crystals obtained by AMMONO method revealed intense and homogenous luminescence. Significant improvement of the optical properties was observed for crystals grown in the presence of Rare Earth elements. For such GaN crystals, helium temperature photoluminescence spectra were dominated by near-band-gap recombination. Exciton lines were extremely narrow, with full-width half-maximum (FWHM) as low as 1 meV. The concentration of uncompensated shallow donors in AMMONO GaN determined by electron paramagnetic resonance measurements was below 5×1015 cm−3.
Crystal Morphology and Optical Emissions of GaN layers grown on Si(111) substrates by Molecular Beam Epitaxy
Authors: Sánchez-García M. A. , Sánchez F. J. , Naranjo F. B. , Calle F. , Calleja E. , Muñoz E. , Jahn U. , Ploog K. H.
Published: August 2016

Crystal morphology of GaN layers grown on Si(111) evolves from whisker-like microcrystals to compact films as a function of the III/V ratio. Small changes in the III/V ratio (from Ga-rich to N-rich) during the growth of a compact layer result in the appearance of microcrystals on the top of the layer, indicating a sharp transition between the two growth regimes.

Four different morphologies are obtained by increasing the III/V ratio: a) completely columnar whisker-like samples exhibiting a pair of intense excitonic emissions at 3.471−3.478 eV; b) a mixture of compact regions with columnar microcrystals showing two pairs of excitonic emissionsnbsp c) compact layers with very small microcrystals on the top surface with a weaker dominant transition at 3.415 eV (±5meV) and, d) full compact and smooth layers with a single dominant excitonic emission at 3.466 eV. A combination of PL measurements with SEM photographs and CL imaging reveals that both pairs of emissions in samples b) come from the columnar microcrystals. The high energy pair (3.471−3.478eV) is attributed to the free-exciton A and a donor-bound exciton while the low energy pair (3.452−3.458eV) is assigned to acceptor-bound excitons associated to valence bands Γ9v and Γ7uv. Power and temperature dependence together with time-resolved data show that the dominant peak at 3.415eV (± 5meV) present in samples c) correspond to a donor-acceptor transition. CL measurements as a function of electron beam energy (depth) also indicate that this emission is more intense towards the interface between the layer and the sample. Finally, the excitonic emission in samples d) is shifted to lower energies due to residual biaxial tensile strain of thermal origin.
Native defects and carbon impurity in cubic BN
Authors: Gorczyca I. , Svane A. , Christensen N. E.
Published: August 2016

Using the Green’s function technique based on the linear muffin-tin orbital method in the atomic-spheres approximation we study the electronic structure of native defects and substitutional carbon impurities in cubic BN. To include the lattice relaxation effects a supercell approach in connection with the full-potential linear muffin-tin-orbital method is applied.
Surface Morphology and Structure of GaNxAs1−x
Authors: Thordson J.V. , Zsebök O. , Södervall U. , Andersson T.G.
Published: August 2016

GaNxAs1−x-layers were grown by solid source molecular beam epitaxy using N2 and excitation by RF-plasma source. The average nitrogen concentration, x, determined by secondary ion mass spectrometry, ranges from isovalent nitrogen doping in GaAs up to GaN. X-ray diffraction revealed two peaks, close to the ones for GaAs(002) and the GaN(002) diffraction, respectively. The position of both peaks moved slightly as a function of nitrogen content. Scanning electron microscopy indicated a rough surface structure with improved smoothing for low and high nitrogen compositions. The rough surface is partly due to crystallite formation when mixing arsenic and nitrogen as a result of phase separation between the GaAs and GaN. In ternary films with very high nitrogen composition there were structural features with a different contrast. These were crystallites that arose at the interface and grew up to the surface.
AlGaN-Based Bragg Reflectors
Authors: Ambacher O. , Arzberger M. , Brunner D. , Angerer H. , Freudenberg F. , Esser N. , Wethkamp T. , Wilmers K. , Richter W. , Stutzmann M.
Published: August 2016

We have studied the dependence of the absorption edge and the refractive index of wurtzite AlxGa1−xN films on composition using transmission, ellipsometry and photothermal deflection spectroscopy. The Al molar fraction of the AlxGa1−xN films grown by plasma-induced molecular beam epitaxy was varied through the entire range of composition (0 ≤ x ≤ 1). We determined the absorption edges of AlxGa1−xN films and a bowing parameter of 1.3 ± 0.2 eV. The refractive index below the bandgap was deduced from the interference fringes, the dielectric function between 2.5 and 25 eV from ellipsometry measurements. The measured absorption coefficients and refractive indices were used to calculate the design and reflectivity of AlGaN-based Bragg reflectors working in the blue and near-ultraviolet spectral region.
Comparison of Luminescence and Physical Morphologies of GaN Epilayers
Authors: Trager-Cowan Carol , Middleton P. G. , O'Donnell K. P. , Ruffenach-Clur S. , Briot Olivier
Published: August 2016

In this paper we examine a series of four GaN epilayers grown by MOVPE on sapphire substrates with different AlN buffer layer thicknesses. We examine the effect of the buffer layer thickness on the physical and optical properties of the samples via optical microscopy, cathodoluminescence imaging and photoluminescence and cathodoluminescence spectroscopy. While the morphological and optical properties of all the films (excepting that with the thinnest buffer layer of 30 nm) are good, i.e., the films are smooth and the luminescence is dominated by excitonic luminescence, a number of circular island like features are observed in all the films whose density decrease with increasing buffer layer thickness. A large circular island present on the sample with the thinnest buffer layer and surrounded by cracks in the directions, displays some interesting acceptor related luminescence.
p-doping of GaN by MOVPE
Authors: Haffouz S. , Beaumont B. , Leroux M. , Laugt M. , Lorenzini P. , Gibart Pierre , Hubert-Pfalzgraf L.G.
Published: August 2016

Mg has been widely used as p-doping species despite its intrinsic difficulties. It is nowadays well established that during the growth process of Mg doped GaN, atomic H is generated from the decomposition of NH3 and Mg-H complexes are formed in the layer. This has been for instance shown by the occurrence of LO mode in IR absorption, and by the observation of the Mg-H local vibration modes. This H passivation limits the electrical activity of Mg, therefore an activation process is required to get full activation of the Mg atoms. In the present study, bismethylcyclopentadienyl magnesium [(MeCp)2Mg] was used as precursor. However, this precursor reacts in the gas phase with NH3 to produce tiny solid particles as evidenced by a very bright diffuse emission visible along the laser beam used for reflectometry measurements. This simplest obvious product would be [(MeCp)Mg(NH2)]m(m≥2). To limit this drawback, Ga and Mg precursor lines have been separated. With proper in situ heat treatment, doping densities up to 1.5×1018 cm−3 have been obtained. PL spectra of lightly Mg doped samples (1016 cm−3) are dominated by shallow donor-acceptor pairs whereas for higher doping densities ( 1018 cm−3), the luminescence is dominated by a broad band in the 2.7-2.9 eV range. GaN LEDs were fabricated from Si doped (n-type) and Mg-doped (p-type) GaN, these LEDs emit in the blue-UV range.
Physical Properties of Bulk GaN Crystals Grown by HVPE
Authors: Melnik Yu.V. , Vassilevski K.V. , Nikitina I.P. , Babanin A.I. , Davydov V. Yu. , Dmitriev V. A.
Published: August 2016

Free standing GaN platelets were fabricated by hydride vapor phase epitaxy (HVPE). The platelets having a current maximum size of 7×6×0.1 mm3 were obtained by HVPE growth of ~100 μm thick GaN layers on SiC substrates and subsequent removal of the substrates by reactive ion etching (RIE). Surface of the GaN platelets was characterized by reflectance high energy election diffraction (RHEED), and Auger electron spectroscopy (AES). Crystal structure and optical properties of the platelets were studied by x-ray diffraction and photoluminescence (PL), respectively. Raman spectroscopy was also applied for material characterization. Residual strain was detected in the crystals. The stress was eliminated by high temperature anneal.
The Morphology and Cathodoluminescence of GaN Thin Films
Authors: Trager-Cowan Carol , Middleton P. G. , O'Donnell K. P.
Published: August 2016

In this paper we compare gallium nitride (GaN) films grown by molecular beam epitaxy on sapphire (Al2O3), gallium arsenide (GaAs (111)B) and lithium gallate (LiGaO2) substrates. Atomic force microscopy, scanning electron microscopy, cathodoluminescence imaging and cathodoluminescence spectroscopy are used to characterise the films. From growth runs carried out to date, GaN films on GaAs substrates exhibit the best surface uniformity and the cleanest luminescence.
Yellow Band and Deep levels in Undoped MOVPE GaN.
Authors: Sánchez F. J. , Basak D. , Sánchez-García M. A. , Calleja E. , Muñoz E. , Izpura I. , Calle F. , Tijero J. M. G. , Beaumont B. , Lorenzini P. , Gibart Pierre , Cheng T. S. , Foxon C. T. , Orton J. W.
Published: August 2016

Undoped layers of GaN grown by MOVPE on sapphire substrates have been characterized by photoluminescence, photocapacitance and photoinduced current transient spectroscopy (PICTS). Photocapacitance reveals in all samples two specific signatures at photon energies of 1 eV and 2.5 eV. The photocapacitance decrease observed at 1 eV seems to be due to an electron capture process from the valence band, whereas the capacitance increase at 2.5 eV is related to an electron emission process. The fact that the capacitance step at 1 eV is only seen after photoionization at energies above 2.5 eV, and the observed correlation between its amplitude and the photoluminescence intensity of the “yellow band”, lead us to conclude that both transitions are linked to the same trap, which is also suggested to be responsible for the yellow band. The position of this trap, at 2.5 eV below the conduction band, is confirmed by PICTS measurements, that show a hole thermal emission activation energy of 0.9 eV at 350 K.
Temperature distribution in the chamber used for crystal growth of GaN under high pressure of nitrogen
Authors: Krukowski S.
Published: August 2016

The theoretical analysis of high pressure influence on the conditions of crystal growth of GaN is presented. High pressure influence on the transport and equilibrium properties of nitrogen is estimated using scaling approach. Nitrogen gas properties are used in the finite element calculation of the thermal conditions in the high pressure chamber. The temperature distribution during GaN growth in the vertical temperature-gradient configuration is obtained.
ECR RIE-Enhanced Low Pressure Plasma Etching of GaN/InGaN/AlGaN Heterostructures
Authors: Humphreys Bedwyr , Govett Matthew
Published: August 2016

A room temperature (RT) plasma etch process has been developed to non-selectively etch GaN/InGaN/AlGaN structures, grown on sapphire substrates, using an electron cyclotron resonance (ECR) plasma source with RIE enhancement. The process chemistry chosen was Cl2/CH4 based in order to facilitate the formation of volatile etch by-products, typically to form group III halides and group V hydrides, although indium is more likely to form an organo-metallic compound as opposed to a chloride. A characteristic of this process is the very smooth sidewall features obtained and the controllability of the etch profile via ECR power, table bias and/or gas flow ratio. Typical results obtained using a RT process were etch rate above 100 nm/min., selectivity to resist mask above 30:1 and smooth anisotropic profile at low ion-energies (below 100 eV). The process etch rate showed a characteristic increase with increasing table bias (above 130 nm/min.) with only small changes in the relative etch rate of each compound (i.e. selectivity maintained at roughly 1:1), however, this etch does rely upon competing etching and deposition mechanisms and thus too large a variation in one parameter without a corresponding compensation with another leads to a rough surface and a more selective etch. The process has also been demonstrated using a metal mask (e.g. Ni) and present work is progressing onto other gas combinations and the use of high temperature electrodes.
Growth of GaN films on (0 0 1) and (1 1 1) GaAs surfaces by a modified MBE method
Authors: Cheng T. S. , Foxon C. T. , Jeffs N. J , Hughes O. H. , Ren B. G. , Xin Y. , Brown P. D. , Humphreys C. J. , Andranov A. V. , Lacklison D. E. , Orton J. W. , Halliwell M.
Published: August 2016

Films of GaN have been grown using a modified MBE method in which the active nitrogen is supplied from an RF activated plasma source. Wurtzite films grown on (0 0 1) oriented GaAs substrates show highly defective, ordered polycrystalline growth with a columnar structure; the (0 0 0 1) planes of the layers being parallel to the (0 0 1) planes of the GaAs substrate. Films grown using a coincident As flux, however, have a single crystal zinc-blende growth mode. They have better structural and optical properties. To improve the properties of the wurtzite films we have studied the growth of such films on (1 1 1)A and (1 1 1)B oriented GaAs substrates. The improved structural properties of such films, assessed using x-ray and TEM methods, correlate with better low temperature PL performance.
High Resistivity AlxGa1−xN Layers Grown by MOCVD
Authors: Polyakov A. Y. , Shin M. , Greve D. W. , Skowronski M. , Wilson R. G.
Published: August 2016

Undoped AlxGa1−xN layers with good surface morphology and very low electron concentration have been grown by MOCVD on sapphire substrates. The observed electrical and optical properties depend strongly on the growth temperature. Layers grown at 1000 °C exhibited low resistivity and strong optical absorption below the bandgap. In contrast,layers grown at 1050 °C had low carrier concentrations and good mobilities. Virtually no optical absorption near the band edge was observed as opposed to the usual situation in AlxGa1−xN. The electrical properties of these layers can be explained by the presence of donor centers whose energy increases with composition, and deeper lying compensating defects. The interaction of these centers renders the samples with x<0.2 highly resistive, with room temperature resistivity higher than 106 ohm-cm. SIMS data strongly suggest that the electrically active centers in our AlGaN layers are native defect-related. Implantation of Si ions into Al0.12Ga0.88N, and subsequent annealing at 1140 °C resulted in layers with electron concentration of 4.6 × 1017cm−3.
Fabrication of GaN mesa structures
Authors: Vassilevski K.V. , Rastegaeva M.G. , Babanin A.I. , Nikitina I.P. , Dmitriev V.A.
Published: August 2016

We report on nickel based technology for the fabrication of GaN mesa structures. Ti/Ni ohmic contacts for n-doped GaN with contact resistivity Rc ~2×10−5  Ω×cm2 and Ni ohmic contacts for p-doped GaN with Rc ~ 4×10−2 Ω×cm2 were formed. Both types of contacts were used as masks for GaN reactive ion etching (RIE) in a CCl2F2/Ar gas mixture. Maximum etch rates of ~ 40 nm/min were obtained. Mesa structures up to 3 μm in height were formed.
Metal Contacts on a-GaN
Authors: Kampen T. U. , Mönch W.
Published: August 2016

The Schottky barrier heights of silver and lead contacts on n-type GaN (0001) epilayers were determined from current-voltage characteristics. The zero-bias barrier heights and the ideality factors were found to be linearly correlated. Similar observations were previously reported for metal contacts on Si (111) and GaAs (110) surfaces. The barrier heights of ideal Schottky contacts are characterized by image force lowering of the barrier only. This gives an ideality factor of 1.01. From our data we obtain barrier heights of 0.82 eV and 0.73eV for ideal Ag and Pb contacts on GaN, respectively. The metal-induced gap states (MIGS) model predicts the barrier heights of ideal Schottky contacts on a given semiconductor to be linearly correlated with the electronegativities of the metals. The two important parameters of this MIGS-and-electronegativity model are the charge neutrality level (CNL) of the MIGS and a slope parameter. The CNL may be calculated from the dielectric band gap and using the empirical tight-binding method. The slope parameters are given by the optical dielectric constant of the respective semiconductor. The predictions of the MIGS model for metal/GaN contacts are confirmed by the results presented here and by barrier heights previously reported by others for Au, Ti, Pt, and Pd contacts on GaN.
Iranian ‘staircase’ villages: structural and seismic issues
Authors: Akbari Reza , Rafiei Yasamin
Published: August 2016

Iran's rural ‘staircase’ villages are located on the lower slopes of mountains. The unique architectural forms of these villages, with the roofs of lower buildings forming the courtyards of upper buildings, make them both interesting and attractive. This paper outlines the general characteristics of Iranian staircase villages, including the structural forms of the buildings, their seismic vulnerability and post-earthquake reconstruction challenges. The performance of staircase villages during earthquakes and related events, and the aspects of existing construction methods in rural areas are assessed in this study. The poor seismic performance of traditional building roofs and supporting walls has been noted. Recommendations on key points of failure and access for rescue issues are addressed here, leading to recommendations on policies related to the seismic upgrading of these rural structures.
Сarbohydrate metabolism parameters under the glutamate-induced obesity in rats and concominant correction with probiotic strains of lactobacilli and bifidobacteria
Authors: Leshchenko I. , Virchenko O. , Gadiliya O. , Falalyeyeva T. , Lazarenko L.
Published: August 2016

To find out the effect of probiotic strains on insulin resistance induced by glutamate-induced obesity in rats. Obesity was induced by neonatal administration of monosodium glutamate (4 mg/g,s.c.) at 2, 4, 6, 8, 10-day life. The introduction of probiotics started at the end of 4 week after birth and continued intermittently for 2-week courses. After 4 months, the rats of all groups glucose and insulin levels and insulin resistance index HOMA were analyzed. Neonatal administration of monosodium glutamate leads to the development of insulin resistance in rats 4 months of age. The periodic introduction of the combined probiotics prevented the development insulin resistance in rats. The most significant effect was revealed in the group of animals treated with the combined probiotic strains Lactobacillus casei IMVB-7280, Bifidobacterium animalis VKL, Bifidobacterium animalis VKB. The results suggest the effectiveness of the use of probiotic strains of bifidobacteria and to prevent the development of insulin resistance.
Correction of oxidative stress in rat blood with magnesium citrate upon experimental diabetes
Authors: Shatynska O. , Iskra R.
Published: August 2016

The investigation of the influence of different concentrations of magnesium citrate (100, 250 and 500 mg/kg body weight) on the lipid peroxidation processes and the activity of the antioxidant system in red blood cell of rats with experimental diabetes was conducted. Diabetes was caused by the single introduction of a 5% solution of alloxan monohydrate. The activity of the enzymes of antioxidant protection, catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase and the content of reduced glutathione were studied in red blood cells. The increasing levels of lipid hydroperoxides and thiobarbituric acid reactive substances against the backdrop of decreased activity of enzymes of antioxidant protection was observed in rats with experimental diabetes. Magnesium citrate, which for four weeks, together with drinking water was added to the diet of the animals, showed a positive normalizing effect. Particularly, the contents of LPO and TBARS declined, and activity of antioxidant systems of protection increased significantly. Our data shows that the magnesium citrate supplements can partly restore the antioxidant parameters and reduce oxidative stress in rats with alloxan-induced diabetes.
Impressions of Anglo-Indian Society in R. Kipling’s Early Creative Art
Authors: Posudiyevska Olga
Published: August 2016

This study concentrates on the analysis of early works by Rudyard Kipling who was born into the family of English colonists to India, thus becoming a representative of the newly formed Anglo-Indian society. The writer’s sketch Anglo-Indian Society (1887) and his collection of short stories Plain Tales from the Hills (1888) depict the characteristic features of Anglo-Indians’ worldview and lifestyle, which are revealed and analyzed by the author of the article. Special attention is paid to biographical factors influencing the author’s choice of Anglo-Indian topic at the beginning of his writing career. The researcher concludes that Kipling presents in his works an outline of Anglo-Indian society which emerged from the writer’s observations of Anglo-Indians’ lives during his work as a reporter. Striving for credibility in consideration of advantages and shortcomings of Anglo-Indian worldview and lifestyle, the author tries to occupy the position of the unconcerned observer, being capable of assessing the situation with fresh mind. Kipling disguises himself under the image of the hero-narrator, being either a tourist traveler from abroad, or a reporter, accustomed to collecting factual material for the local paper, in such a way receiving an opportunity to speak ironically and sometimes even sarcastically about certain models of behavior, accepted by Anglo-Indians.
The Power of being Color-Blind in To Kill a Mockingbird
Authors: Rezazade Faeze , Zohdi Esmaeil
Published: August 2016

Discrimination and racial injustice towards Blacks have existed among the groups of people since the very beginning of their gatherings as a communication and society. Throughout history, people of colored skin, especially Blacks, were not accepted in the Whites’ communities due to the Whites’ thought of supremacy over them. Regardless of their positive role and doing manual labor in keeping the wheels of the Whites’ industry turning, Blacks were always treated as nonhuman and “clownish” creatures born to serve Whites. African Americans are the main groups of Blacks who suffer from discrimination and racial injustice because they are living among Whites, though segregated from the Whites’ society. However, there are many white individuals who do not consider the skin color and treat Blacks as human beings and only humanity and good nature of the people matters to them. Nelle Harper Lee in her masterpiece, To Kill a Mockingbird, written in 1960, introduces three children (Scout, Jem, and Dill) and Atticus, who is Scout and Jem’s father, as color-blind characters who fraternize with Blacks as humans without paying attention to their skin color. Therefore, using W. E. B. Du Bois’ thoughts- regarding prejudice, discrimination, and racial injustice- in this article it has been tried to investigate Atticus’ and three children’s color blindness in the case of racism in To Kill a Mockingbird.
Playing the Old Tunes: A Fiskean Analysis of Baz Luhrmann’s 2013 Cinematic Adaptation of The Great Gatsby
Authors: Khodamoradpour Marjan , Anushiravani Alireza
Published: August 2016

Scott Fitzgerald’s The Great Gatsby has been adapted many times by different directors. However, the two prominent adaptations standing out throughout history are Jay Clayton’s 1974 adaptation as the most sincere rendering of the book, and the recently adapted movie by the Broadway director, Baz Luhrmann. The latter adaptation is important in that it has been accomplished in the age of technology, in 3D format, and at the time of the new readings, i.e. cultural or new historical readings, of the novel. This paper is an endeavor to analyze the movie through John Fiske’s theory on media studies. Also, an effort has been made to see whether in this new adaptation, the idea of the new studies of the novel have been shown by the director, or else the movie is a mere representation of struggle for money discussed by the traditional Marxist scholars, metaphorically playing the old tunes.
Locking compression plate in humeral shaft nonunion: a retrospective study of 18 cases
Authors: Govindasamy Rajesh , Gnanasundaram Ramkumar , Kasirajan Saravanan , Thonikadavath Fawas , Rajadurai Jeff Walter
Published: August 2016

Background: Humeral shaft nonunions are frequently seen in Orthopaedic practice. Osteosynthesis with bone grafting is the treatment of choice. Locking compression plate (LCP) is the latest implant used in treating them. We retrospectively evaluated the outcome of use of LCP in humeral shaft non-union resulted by both conservative management and following failed internal fixations.

Methods: Eighteen patients with nonunion of humeral shaft in which ten were treated by traditional bone setters and eight followed by failed internal fixation were included in these study. The mean duration of nonunion was 18.3 months (range 8-22).  The mean follow up period was 18 months (range 12-26). The mean age of patients was 44.4 years (range 22-60). All patients underwent osteosynthesis with LCP and autologoous cortico-cancellous iliac crest graft. The outcome measures include radiographic assessment of fracture union and preoperative and postoperative function using modified constant and murley scoring system.

Results: All fractures united following osteosyntesis average time for union was15 weeks (range 10-24). We did not have any delayed union or non-union. The complications were superficial infection (n=1) and wound haematoma (n=1).Three patients with preoperative radial nerve palsy recovered at the end of four months. Functional evaluation using constant-murley score showed excellent result in 14, good in 3 and fair in 1. We did not have any poor results.
Conclusions: LCP with cancellous bone grafting is a safe reliable option for all forms of humeral shaft nonunion. We recommend it.
Социальный проект благотворительной программы «Дорога к дому» как пример государственно-частного партнерства в решении проблемы социального сиротства
Authors: Смирнова Елена Анатольевна , Заболтина Вера Витальевна
Published: August 2016

Статья посвящена вопросу государственно-частного партнерства в сфере расширения и совершенствования социальных услуг в целях формирования эффективного сотрудничества государства, бизнес-сообщества и неравнодушных граждан. Благотворительный фонд как некоммерческая организация инициирует совместные социальные проекты и межведомственное взаимодействие, развивая государственно-частное партнерство. Проект «С первых дней» благотворительной программы «Дорога к дому» как пример ГЧП в социальной сфере. Социальные программы не являются односторонними, они основываются на принципе участия, включения материальных, финансовых и временных ресурсов в той или иной степени всех задействованных групп общества.
Reflective Practice in Healthcare Education: An Umbrella Review
Authors: Fragkos Konstantinos
Published: August 2016

Reflection in healthcare education is an emergent topic with many studies and reviews being published. The purpose of the present review is to map the literature in this field by performing a systematic review of reviews (umbrella review) and to explore which definitions and models are currently in use, how reflection impacts on design, evaluation and assessment and future challenges. Nineteen reviews were identified that satisfied inclusion criteria. Emerging themes were: reflection is currently portrayed as self-reflection and critical reflection with the epistemology-of-practice notion not being as much as expected in tandem with the evidence-based-medicine paradigm modern science advocates. Reflective techniques were recognised in multiple settings (e.g. summative, formative, group vs individual etc.) and have been associated with learning but assessment remains a research topic with issues of validity, reliability and replicability. Future challenges involve the epistemology of reflection in healthcare education and how to practice and assess reflection without losing its theoretical background.
Geometric Theory of Heat from Souriau Lie Groups Thermodynamics and Koszul Hessian Geometry: Applications in Information Geometry for Exponential Families
Authors: Barbaresco Frédéric
Published: August 2016

We introduce the Symplectic Structure of Information Geometry based on Souriau’s Lie Group Thermodynamics model, with a covariant definition of Gibbs equilibrium via invariances through co-adjoint action of a group on its moment space, defining physical observables like energy, heat, and moment as pure geometrical objects. Using Geometric (Planck) Temperature of Souriau model and Symplectic cocycle notion, the Fisher metric is identified as a Souriau Geometric Heat Capacity. Souriau model is based on affine representation of Lie Group and Lie algebra that we compare with Koszul works on G/K homogeneous space and bijective correspondence between the set of G-invariant flat connections on G/K and the set of affine representations of the Lie algebra of G. In the framework of Lie Group Thermodynamics, an Euler-Poincaré equation is elaborated with respect to thermodynamic variables, and a new variational principal for thermodynamics is built through an invariant Poincaré-Cartan-Souriau integral. The Souriau-Fisher metric is linked to KKS (Kostant-Kirillov-Souriau) 2-form that associates a canonical homogeneous symplectic manifold to the co-adjoint orbits. We apply this model in the framework of Information Geometry for the action of an affine Group for exponentiel families, and provide some illustration of use cases for multivariate Gaussian densities. Information Geometry is presented in the context of seminal work of Fréchet and his Clairait-Legendre equation. Souriau model of Statistical Physics is validated as compatible with Balian gauge model of thermodynamics. We recall the precursor work of Casalis on affine group invariance for natural exponential families.
Maximizing Drilling Performance with Real-Time Drilling Vibration Mitigation in the Deep Wells
Authors: Cui M. , Wang G. H. , Ge H. Y. , Chen X. Z. , Guo H. W.
Published: August 2016

The present Tarim Basin of China presents drilling chanllenges moving toward deeper hydrocarbon reservoirs, which includes more complex formation, poor bit cutting efficiency and wellbore integrity. The paper introduces the development and application of optimizer of drilling operating parameters named as Smart Driller Indicator (SDI) which worked to deliver continuous improvement in axial vibration and stick-slip mitigation for the presented field.

SDI is based on a soft-closed-loop solution called NAVO real-time vibration monitoring and calculating the optimal drilling parameters for that formation by maintaining an optimum relationship between ROP and energy input. From the perspectives of rock mechanics and conservation of energy, the ideal performance in the optimum proportion among drilling parameters, ROP and MSE have been derived from comprehensive analysis of optimized drilling mechanism. An advanced damped forced torsional vibrarion model in frenquency-domain was developed. Field validation for real-time estimates produced by the model was conducted by a drilling mechanics module sub.

In drlling process, if the ROP is not as good as expected, SDI will automatically evaluates the new hole conditions including the mechanical properties of the formation, bit wear condition and vibration etc, and updates the optimum drilling parameters. The drillers just adjust drilling parameters to follow them, a higher ROP (rate of penetration) and a longer bit run can be achieved. SDI has been applied for more than 20 wells with total footage of over 30,000ft and has shown about 20%-54% ROP improvement and longer bit life compared with conventional driller's drilling habits and totally 125 days and about 1 million dollars have been saved.

As an effective tool for further excavating the potential of ROP, SDI might achieve satisfactory outcomes that overcome the drilling challenges of carbonate formation, gravel and igneous in deep wells.
Improving Operational Cost with SAP
Authors: Taylor Joseph A.
Published: August 2016

For decades, the E&P industry has generated vast quantities of data derived from exploration, development, production and operations. However, very few E&P companies have leveraged the many terabytes of data they generate every day to drive their businesses forward, much less empower themselves with insights-driven decision-making.

In August 2014, the price of a barrel of oil on the global market reached a price of $108.88 (see Figure 1). Although cost plays an important part in determining profits, it wasn't as much of a focus at that point in time. Let's be honest: At that price, the number of assets that could be labeled profitable was on the high side. As a result, the larger E&P companies started to make major capital investments, while a larger number of smaller E&P companies started to appear. This price attracted a lot of attention, prompting E&P companies in the US to make big investments in Shale Plays. Canada increased its investments in Oil Sands. And the US, the world's largest consumer of oil, started making mandates on MPG for vehicles. SCADA systems were the kings of data collection and Production Optimization & Maintenance & Reliability became household phrases. The thought was that even a low producing well could be profitable. In Feb 2016, less than 18 months later, the price of oil plummeted to a low of $33.62 per barrel.
Prescriptive-Based Decision Support System for Online Real-Time Electrical Submersible Pump Operations Management
Authors: Adesanwo Moradeyo , Denney Tommy , Lazarus Sony , Bello Oladele
Published: August 2016

Economic development and operations of new discoveries in frontier environments require advancements in production enhancement technologies, which take advantage of existing infrastructures and reduce overall operating expenses. These production enhancement technologies such as downhole pumping and gas lift (artificial lift technologies); injection of diluents, foamers and chemicals; water and/or fluid injection; often represent the only viable option to enhance well productivity, maximize production and improve recovery of hydrocarbon resources.

Electrical submersible pump (ESP) systems are becoming the fastest growing form of artificial lift pumping technology, with more than 25% of the wells worldwide deploying ESP to surface their hydrocarbons and with more ESP systems being deployed to harsh and remote environments. With the rapid growth of ESP technologies, an appropriate prescriptive-based decision support system is needed to prevent or avoid critical system failures by analyzing the large amount of (observations, algorithms and calculated) information for extending run-time, increasing production and keeping well operation safe. The majority of the existing solutions provide real time data trending, alarming, ESP analysis and diagnostics.

In this work, an efficient and reliable automated system is proposed for change point and anomaly detection, event or fault diagnosis and decision support in ESP operations. Our workflow consists of a quantitative method which combines streaming sensor data, data-rich detection and diagnosis model, fuzzy rule-based expert system and an influence diagram technique to perform prescriptive analysis and provide online real-time recommended action and/or corrective measures concerning the optimal alternative actions to be executed during undesirable ESP incidents or events. System features include a real-time data acquisition device, a real-time modeling engine, a real-time model calibration engine, fault detector program and a fuzzy logic rule-based system that uses an influence diagram technique to advice on ESP operating conditions. The proposed procedure is tested in multiple fields to verify the functionalities of the system. The results show that the proposed methodology can be efficiently used in practice. The methodology was used in several case studies and produced superior results in comparison to conventional methods.
Automatic Performance Analysis and Estimation of Risk Level Embedded in Drilling Operation Plans
Authors: Cayeux Eric , Daireaux Benoît , Karimi Balov Mohsen , Haavardstein Stein , Magne Stokland Leif , Saasen Arild
Published: August 2016

It is not unusual that the difficulties encountered during a drilling operation can be tracked down to choices made during the planning stage. However, generating a robust drilling operation plan is not easy as there are often substantial uncertainties associated with the actual geological context. To address this problem, a method is proposed that evaluates quantitatively the risk levels of a drilling operational plan as a function of the underlying uncertainty associated with its description.

To achieve that goal, the first task is to describe precisely the sources of uncertainties. The limits by which a drilling operation shall conform may be uncertain therefore defining fuzzy risk boundaries. The actual well construction may deviate from the plan, either because of unavoidable uncertainties in measurements as with the actual wellbore position, or because adjustments will be made during the operation such as changes in mud weight and rheology. Finally, the actual possible drilling performance may be subject to unforeseen geological variations and unprecise formation rock strength characteristics.

Equipped with this probabilistic environment, we can perform drilling optimization in two successive steps. First, the uncertainty is propagated into drilling simulations, and risks associated to pressure control, cuttings transport, and drillstring stability are evaluated. Second, parameter optimization within the allowed window, can provide a strategy to obtain the best performance possible with respects to acceptable risk levels. As a result, both quantitative risk analysis and drilling optimization under several constraints are available to the drilling engineer as a decision support tool for well planning.
Automated Procedures - A New Way of Improving Efficiency and Safety
Authors: Wilkins Maurice J.
Published: August 2016

Automated procedures sound simple and yet they have not been used in the past by many of the so-called continuous industries, including upstream. As the upstream industry is looking more and more at moving to unmanned remote operations, this paper will show how major operators have obtained both operational and safety benefits by using procedure management techniques.

Procedures can be operated manually, semi-automatically and automatically. Modular Procedural Automation analyses the best practices of major operators and syntheses them into repeatable procedures. They are then presented in a format that operators can easily identify and act upon or they can be run automatically, even from a remote location.

Major owner/operators, including one major GOM operator, have found substantial savings by using procedure automation techniques. This paper will give illustrations of the benefits obtained by several owner operators by using procedure management and it will also look at the aircraft and medical industries to show how procedures have helped to improve their operations and ensure consistency and repeatability.

After the Deepwater Horizon incident major GOM operators are turning to procedure management techniques to ensure safer and more efficient operations. In terms of innovation, several of the major operators both onshore and offshore are looking at ways to operate facilities remotely and unmanned. A key requirement for this to be achieved in my opinion is the use of automated procedures
The Use of Well Integrity Management Systems & Software to Increase Organisational Understanding
Authors: Connon Stuart , Corneliussen Kjell
Published: August 2016

Total E&P UK (TEPUK) operates a diverse portfolio of both surface and subsea fields in the UK continental shelf. Despite a wide variety of technical design, well architecture and operating conditions of these assets it is of the upmost importance to be able to manage the wells integrity consistently at all times.

As the role of the Well Integrity Engineer continues to expand and mature within the industry, a greater focus is being given to the ability of tools utilised by the responsible engineers and the organisation to be able to quickly interrogate the Well Integrity Management database and provide concise support to well operations.

Having recognised the importance of robust well integrity management, TEPUK set an objective to increase its organisational understanding of well integrity through the use of effectively presented data.

A systematic approach to well integrity related data collection and structured archiving through the use of a single point central software system is key to ensuring that the required information is readily available and easily extractable to an organisation. This can however lead to a complex database that may be troublesome for an untrained user to navigate and interpret to find the ‘right information’. Through standard pre-generated reporting formats, personnel training and education, and a simple user interface that displays a collection of the critical information, an organisation's culture can be transformed, leading to a clearly visible increase in understanding.

This paper presents examples of the results observed that clearly demonstrate not only an increased understanding, but also an increasing sense of ownership of the tasks related to wells and subsequent management of their integrity.
Improving Data Quality in WITSML Data
Authors: Svensson Inge , Wooley Matthew , Halland Thomas
Published: August 2016

Data quality issues have for many decades been a problem for drilling data. To some extent, development of data transfer standards has helped out in achieving better data quality and data transport. In the early stages of WITSML, poor data quality was a concern and in this paper we will be looking at various steps that have been taken to improve data quality.

Sensor technology has improved a lot in recent years with fieldbus options which allow for remote calibration and diagnostic. In addition calibration routines are streamlined and range checks can be implemented at point of acquisition. The data acquisition software now has some inbuilt quality control to addresses errors in manual data input. In addition we have developed software at the rig-site that will perform several data quality checks in the database.

After acquisition, the data is converted and transferred to a central hosted WITSML 1.4.1.1 server. Here several applications will perform data quality assurance on the data, e.g. to check for data gaps. In addition the data flow is monitored 24/7 from an operation center before data is consumed by several applications.

We have been working closely with one operator for several years to improve processes in WITSML data deliveries. To ensure there is an agreement of what data is expected to be delivered, this company has established electronic order forms that will be sent to us for quality check before the section starts. In addition this operator has developed a sophisticated data quality monitoring system that will produce KPI scores linked to the SLA.

Some results from research in using statistics to uncover abnormal sensor response in acquired data will also be presented. Statistic will show how data quality is improving while the amount of data is acquired from one rig is increasing year by year.