bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrons and Phonons in amorphous Si: Deformation Potentials and Solutions of the Time Dependent Schrödinger Equation
Authors: Drabold D. A. , Li Jun
Published: March 2017

We employ first principles methods to explore the coupling between electrons and the lattice in amorphous silicon (a-Si). First we compute the adiabatic electronic response to phonon modes in a realistic model of a-Si. Then, we present a simulation of the electron dynamics of localized edge states in a-Si at room temperature by integrating the time dependent Schrödinger equation. We study the character of the spatial and spectral diffusion of the localized states and directly simulate and reveal the nature of thermally driven hopping. Phonon-induced resonant mixing leads to rapid electronic diffusion if states are available nearby in energy and real-space. We believe that many of the results we obtain are central to modeling transport involving localized states.
Effect of Filament Material on the Decomposition of SiH4 in Hot Wire CVD of Si-Based Films
Authors: Duan H. L. , Zaharias G. A. , Bent Stacey F.
Published: March 2017

The choice of filament material has an effect on the decomposition of silane during the hot wire chemical vapor deposition (HW-CVD) of amorphous and microcrystalline silicon films. The Si radicals produced from W, Re, Mo and Ta filament materials have been probed by laserbased single photon ionization (SPI) as a function of hot wire temperature. The Si radical profiles are shown to demonstrate two distinct regimes: a regime below 1600°C-1800°C (depending on filament material) limited by surface reaction at the filament in which Si concentration increases monotonically; and a mass transfer limited regime above 1600°C-1800°C where Si intensity saturates. The apparent activation energy of Si radical production in the surface reaction regime from Ta (140-170 kcal/mol) is found to be close to the corresponding Si thermal desorption energy from a Ta surface, suggesting that the Si production is controlled by the desorption process from the bare metal. On the other hand, the Si activation energies from W and Re (30-60 kcal/mol) are lower than the related desorption energies, suggesting that other rate limiting reactions play a role for these materials. The apparent activation energy for the Mo surface (60-90 kcal/mol) is intermediate between the other metal values. In addition to the Si radical study, corresponding film deposition is detected in situ by multiple internal reflection infrared (MIR-IR) spectroscopy. The IR measurements have been used to estimate the growth rate of a-Si:H deposited on a Ge substrate. The results show similar activation energies for both the growth rate and the Si formation from a W filament, implying that Si radical production and subsequent film growth may be dominated by the same elementary reactions within the decomposition and film growth processes at low pressure.
Fabrication and Characterization of Polycrystalline Silicon Thin Films by Reactive Thermal CVD with Si2H6 and F2
Authors: Lee J. W. , Shimizu K. , Hanna J.
Published: March 2017

Low-temperature growth of polycrystalline Silicon thin films has been investigated to fabricate thin film transistors by a new thermal CVD with the reactive source gases, Si2H6 and F2, resulting in the film growth at a low-temperature less than 500°C. In order to establish the optimal condition, gas pressure, total gas flow rate of Si2H6+F2 and He as a carrier gas, and residence time, τ, were tuned. Deposition rates and film crystallinity were influenced by the gas flow rations. The growth rate was 3.2-4.2[nm/min] and film uniformity was within ±6.5% over 4cm2 area. High crystallinity films showed a sharp peak at 520[cm-1] in Raman spectra whose full width at half maximum was 6-8[cm-1]. The high crystallinity even at the early stage of film growth was confirmed by transmission electron microscopy. The conductivity and activation energy is on the order of 10-5-10-6 [S/cm] and 0.53[eV], respectively, after hydrogenation. We fabricated poly-Si bottom-gate TFT that have field effect mobility as high as 32.3cm2/Vs and on/off current ratio of 104.
Defects in Microcrystalline Silicon Prepared With Hot Wire CVD
Authors: Finger F. , Klein S. , Dylla T. , Baia Neto A. L. , Vetterl O. , Carius R.
Published: March 2017

The influence of the preparation conditions in hot wire chemical vapour deposition (HWCVD) on the electronic properties of microcrystalline silicon is investigated in view of application of the material in thin film solar cells. Poor grain boundary passivation, as a result of hydrogen etching at strong hydrogen dilution of the process gas or thermal desorption of hydrogen at high deposition temperatures, is considered a main obstacle for material optimisation. We conclude that optimum μc-Si:H solar cell material, both from HW-CVD and from plasma enhanced CVD, is not necessarily obtained with largest grain sizes and apparent highest crystalline content, but rather by a material prepared under conditions which yield a compact morphology with an effective grain boundary passivation.
Large-Grain Polysilicon Films with Low Intragranular Defect Density by Low-Temperature Solid-Phase Crystallization
Authors: Bo Xiang-Zheng , Yao Nan , Sturm J. C.
Published: March 2017

Solid phase crystallization (SPC) of a-Si: H at 600°C was investigated by transmission electron microscopy (TEM) and Raman spectroscopy in a cantilever structure, where the underlying SiO2 was removed prior to the crystallization. The absence of the underlying oxide leads to both a higher grain size and a lower intragranular defect density. The grain size increases from 0.6 μm in regions with the underlying oxide to 3.0 μm without the underlying oxide, and the intragranular defect density decreases one order of magnitude from ∼ 1011 cm-2 to ∼ 1010 cm-2. The improvements in material quality without the lower a-Si/SiO2 interface are thought to be due to a lower nucleation rate and a lower tensile stress with an easier silicon atomic rearrangement at the lower silicon interface.
Optical properties of Microcrystalline Silicon determined by Spectroscopic Ellipsometry and Photothermal Deflection Spectroscopy
Authors: Jun Kyung Hoon , Stiebig Helmut , Carius Reinhard
Published: March 2017

The effect of the microstructure and bonded hydrogen on the optical properties of microcrystalline films (μc-Si:H) was investigated by Spectroscopic Ellipsometry (SE) and Photothermal Deflection Spectroscopy (PDS). On samples with a high crystalline volume fraction we studied the reason for a large deviation of absorption coefficient in the energy range between 1.6 eV and 3.2 eV from the value predicted by effective medium theory. This enhancement can be attributed to scattering by the inhomogeneity of μc-Si:H, which is investigated by the introduction of the dense medium radiative transfer formalism to an optical scattering simulation. Further, we suggest strain as a reason for the enhanced absorption in highly crystalline μc-Si:H.
Characterization of Microcrystalline Transition from Amorphous Silicon as a Function of Hydrogen Dilution and Substrate Temperature of Hot-wire CVD
Authors: Wang Keda , Zhang Haoyue , Zhang Jian , Owens Jessica M. , Weinberg-Wolf Jennifer , Han Daxing , Gedvilas Lynn , Nelson Brent
Published: March 2017

a-Si:H films were prepared by hot wire chemical vapor deposition. One group was deposited at a substrate temperature of Ts=250°C with varied hydrogen-dilution ratio, 0<R<10; the other group was deposited with fixed R=3 but a varied Ts from 150 to 550°C. IR, Raman and PL spectra were studied. The Raman results indicate that there is a threshold value for the microstructure transition from a- to μc-Si. The threshold is found to be R ≈ 2 at Ts = 250°C and Ts ≈ 200°C at R=3. The IR absorption of Si-H at 640 cm-1 was used to calculate the hydrogen content, CH. CH decreased monotonically when either R or Ts increased. The Si-H stretching mode contains two peaks at 2000 and 2090 cm-1. The ratio of the integral absorption peaks I2090/(I2090+I2090) showed a sudden increase at the threshold of microcrystallinity. At the same threshold, the PL features also indicate a sudden change from a- to μc-Si., i.e. the low energy PL band becomes dominant and the PL total intensity decreases. We attribute the above IR and PL changes to the contribution of microcrystallinity, especially the c-Si gain-boundaries.
Effects of Deposition Temperature and Film Thickness on the Structural, Electrical, and Optical Properties of Germanium Thin Films
Authors: Jordan William B. , Wagner Sigurd
Published: March 2017

Germanium films deposited on glass by plasma-enhanced chemical vapor deposition from germane and hydrogen grow in the structure succession of amorphous-nanocrystallineamorphous-nanocrystalline as the substrate temperature is raised from 30°C to 310°C. We ascribe the phase formation, from low to high temperature, to a sequence of low to high mobility of Ge growth species on a surface that is hydrogenated at low temperature but not hydrogenated at high temperature. We report some structural, optical, and electrical transport properties of Ge films as a function of deposition temperature and film thickness.
Properties of amorphous silicon-germanium films and devices deposited at higher growth rates
Authors: Liu Yong , Dalal Vikram L.
Published: March 2017

We report on the growth and properties of amorphous Silicon-Germanium [a–(Si,Ge):H] films and devices fabricated at growth rates of ∼ 5 Å/sec using a remote ECR plasma growth process. The films and devices were made using mixtures of germane and silane along with dilution with hydrogen and helium. The addition of He to the gas mixture significantly increased the growth rates. It was found that hydrogen was always necessary in order to achieve the best film and device properties. Films and devices were made across the entire bandgap range, from a-Si to a-Ge. High ratios of photo/dark conductivity and low values of Urbach energy ( > 50 meV) indicate good film properties. The defect densities were measured using space charge limited current techniques. The defect densities were in the range of 1-2 x 10 16/cm 3 –eV, about 5 times higher than for a-Si:H. Electron mobility-lifetime products were measured and found to be in the range of 2-4 x 10-7 cm2/V, even for low gap materials (1.35 eV). Single and graded gap devices were fabricated in these materials. Device fill factors of ∼ 70% were obtained in graded gap devices.
Expanding Thermal Plasma Deposition of Silicon Dioxide-Like Films for Microelectronic Devices
Authors: Creatore M. , van Hest M.F.A.M. , Benedikt J. , van de Sanden M.C.M.
Published: March 2017

In this paper we report on the use of the expanding thermal plasma (ETP) technique for the deposition of carbon-free SiO2 films by means of hexamethyldisiloxane (HMDSO)/oxygen mixtures, at a growth rate of 8-10 nm/s. Information concerning the film chemical properties and refractive index/growth rate have been obtained by means of FTIR measurements and in situ single wavelength ellipsometry, respectively. Because of its geometry, the ETP configuration has proven its suitability for studies concerning the fragmentation paths of the HMDSO molecule and the reactions occurring in the plasma phase. In this framework, very recent results obtained by coupling the SiO2 film-deposition set up with a very sensitive, high spectral resolution- absorption technique, Cavity Ring Down Spectroscopy, are presented.
Monte-Carlo Simulation of Generation- Recombination Noise in Amorphous Semiconductors
Authors: Badran R.I. , Main C. , Reynolds S.
Published: March 2017

We compare the predictions of several analytical models for conductivity fluctuations in a homogeneous semiconductor containing discrete and distributed traps, using a Monte-Carlo simulation of the relevant multi – trapping (MT) transitions. The simulation directly embodies the statistical features associated with such processes, in a simple ‘model - independent’ approach, free of approximations and assumptions. We compare the results with those of several analytical approaches. In one, the noise spectrum is assumed to reflect separately, the characteristic individual release time constants of the various trapping centers in the material. In another, the trapping time into the ensemble of electron traps is taken to be the dominant time constant, and hence, in a material such as a-Si:H, where the trapping time into tail sates is of order 1ps, this is taken to imply that this component of the conductivity noise spectrum is unobservable in practice. Our own analytical approach, incorporates coupling (albeit weak) between traps, which necessarily communicate via the extended states. Preliminary results of the simulation support our thesis, and verify that the same information is contained in the real part of the modulated photoconductivity (MPC) spectrum. A ‘full Monte’ – Carlo simulation incorporating all gap states and spatial inhomogeneities is now a priority.
Medium Range Order and 1/f Noise in Hydrogenated Silicon Thin Films
Authors: Belich T. J. , Kakalios J.
Published: March 2017

Measurements of the second spectra and correlation coefficients of conductance fluctuations are reported for a series of n-type doped a-Si:H films for which the deposition conditions are systematically varied. The non-Gaussian character of the 1/f noise is found to decrease with decreasing deposition temperature, which is also correlated with an increase in the difference between the conductivity and thermopower activation energies (the Q-function). The decrease in non-Gaussian statistics is interpreted as a decrease in the interactions between inhomogeneous current filaments due to increasing long-range disorder in the material.
Characterization of a-SiCx:H Films for c-Si Surface Passivation
Authors: Vetter M. , Martín I. , Orpella A. , Voz C. , Puigdollers J. , Alcubilla R.
Published: March 2017

Amorphous intrinsic silicon carbide (a-SiCx:H(i)) films and amorphous phophorous doped silicon carbide (a-SiCx:H(n)) films deposited by plasma enhanced chemical vapor deposition (PECVD) from silane/methane mixtures provide excellent electronic passivation of p-type c-Si. Effective surface recombination velocities (Seff) lower than 23 cm s-1 have been reported for a- SiCx:H(i) films and Seff < 11 cm s-1 for a-SiCx:H(n) films. The analysis of the dependence of Seff on the injection level indicates that the good electronic passivation is due to field-effect passivation resulting from a high fixed charge (Qf) created in the a-SiCx:H film. In this work the absorption of SiH bonds in infrared transmission spectra of a-SiCx:H films is quantitatively analysed resulting in about 30% smaller amount of SiH bonds in phosphorous doped films compared to intrinsic films. Furthermore, a strong reciprocal correlation of the hydrogen content in the films and the Qf created at the a-SiCx:H/c-Si interface is observed.
Microcrystalline Silicon for Solar Cells at High Deposition Rates by Hot Wire Cvd
Authors: Schropp R. E. I. , Xu Y. , Iwaniczko E. , Zaharias G. A. , Mahan A. H.
Published: March 2017

We have explored which deposition parameters in Hot Wire CVD have the largest impact on the quality of microcrystalline silicon (μc-Si) made at deposition rates (Rd) < 10 Å/s for use in thin film solar cells. Among all parameters, the filament temperature (Tfil) appears to be crucial for making device quality films. Using two filaments and a filament-substrate spacing of 3.2 cm, μc-Si films, using seed layers, can be deposited at high Tfil (∼2000°C) with a crystalline volume fraction < 70-80 % at Rd's < 30 Å/s. Although the photoresponse of these layers is high (< 100), they appear not to be suitable for incorporation into solar cells, due to their porous nature. n-i-p cells fabricated on stainless steel with these i-layers suffer from large resistive effects or barriers, most likely due to the oxidation of interconnected pores in the silicon layer. The porosity is evident from FTIR measurements showing a large oxygen concentration at ∼1050 cm-1, and is correlated with the 2100 cm-1 signature of most of the Si-H stretching bonds. Using a Tfil of 1750°C, however, the films are more compact, as seen from the absence of the 2100 cm-1 SiH mode and the disappearance of the FTIR Si-O signal, while the high crystalline volume fraction (< 70-80 %) is maintained. Using this Tfil and a substrate temperature of 400°C, we obtain an efficiency of 4.9 % for cells with a Ag/ZnO back reflector, with an i-layer thickness of only ∼0.7 μm. High values for the quantum efficiency extend to very long wavelengths, with values of 33 % at 800 nm and 15 % at 900 nm, which are unequalled by a-SiGe:H alloys. Further, by varying the substrate temperature to enable deposition near the microcrystalline to amorphous transition (‘edge’) and incorporating variations in H2 dilution during deposition of the bulk, efficiencies of 6.0 % have been obtained. The Rd's of these i-layers are 8-10 Å/s, and are the highest to date obtained with HWCVD for microcrystalline layers used in cells with efficiencies of ∼6 %.
Thin-Film Transistors on PET at 100°C
Authors: Conde J.P. , Alpuim P. , Chu V.
Published: March 2017

Bottom-gate amorphous silicon thin-film transistors were fabricated on a polyethylene terephthalate substrate. The maximum processing temperature was 100°C. The transistor characteristics are comparable, although still inferior, to those of standard amorphous silicon transistors fabricated on glass substrates. To obtain these characteristics, an extended anneal the processing temperature was required. The devices were fabricated using separately optimized low-temperature active layer, contact layer and gate dielectric layer. To achieve good electronic properties for these layers, hydrogen dilution was required.
Modeling of the Band Gap Profile in the Intrinsic Layer of the a-SiGe:H Material: Application in Solar Cells
Authors: Zambrano Raul Jimenez , Rubinelli Francisco A. , Arnoldbik Wim M. , Rath Jatindra K. , Schropp Ruud E.I.
Published: March 2017

A new band gap profile (exponential profile) for the active layer of the a-SiGe:H single junction solar cell deposited by plasma enhanced CVD (PECVD) has been designed and experimentally demonstrated. In this work we study the difference between the experimental results and the computer simulation. Using Rutherford Backscattering Spectrometry (RBS) significant differences were found between the composition profile as expected from variations in the gas phase ratio GeH4/SiH4 during the deposition and the actual Ge/Si depth profile as determined by RBS. This has important implications for the design of bandgap-graded a-SiGe:H cells. Among others, a delayed response of the plasma conditions due to the changes in the GeH4 flow is studied.
Dependence of the Lateral Photoeffect in a-Si:H P-I-N Structures on the Material Characteristics Studied by Means of a Numerical Simulation
Authors: Fantoni A. , Fernandes M. , Vieira M.
Published: March 2017

When an a-Si:H p-i-n structure is locally illuminated by a light spot, the non uniformity of light causes the appearance of a gradient in the carrier concentration between the illuminated and the dark zone. Carrier start to flow in agreement with such gradients, and when equilibrium is reached, the lateral diffusion process is counterbalanced by the appearance of a lateral component of the electric field vector in addition to the transverse usual one. The lateral fields act as a gate for the lateral flow of the carriers and small lateral currents appears at the transition region between the illuminated and the dark zone. Known as lateral photo-effect, this phenomena depends on the incident light wavelength, light intensity and on the applied bias. Anyway, its intensity can be, depending on the foreseen application, alternatively enhanced or reduced by correct device engineering. We have used the 2D numerical simulator ASCA to analyze the behavior of a-Si:H p-i-n structures under local illumination with the goal of observing the appearance of the lateral components of the electric field and current density vectors. The dependence of the lateral potential redistribution on the doping density, density of defects in the intrinsic layer, and layer thickness have been analyzed. This study aims to show how material properties and device geometry can be combined in order to control the lateral photo-effect.
Short Channel Poly-Si TFT with Single Grain Boundary by Excimer Laser Annealing on Al-masked a-Si Layer
Authors: Jung Sang-Hoon , Lee Jae-Hoon , Han Min-Koo
Published: March 2017

A short channel polycrystalline silicon thin film transistor (poly-Si TFT), which has single grain boundary in the center of channel, is reported. The reported poly-Si TFT employs lateral grain growth method through aluminum patterns, which acts as a selective beam mask and a lateral heat sink during the laser irradiation, on an amorphous silicon layer. The electrical characteristics of the proposed poly-Si TFT have been considerably improved due to grain boundary density lowered. The reported short channel poly-Si TFT with single grain boundary exhibits high mobility as 222 cm2/Vsec and large on/off current ratio exceeding 1 × 108.
Supersonic-Free-Jet CVD Growth of Dy-doped Silicon Films for 1.3 Micron LED
Authors: Kawai Shinji , Matsutake Koji , Watanabe Fumiya , Motooka Teruaki
Published: March 2017

We have investigated epitaxial growth of dysprosium (Dy)-doped silicon (Si:Dy) thin films for fabrication of 1.3 μm light-emitting diodes (LEDs) using supersonic-free-jet CVD. The 700-nm-thick Si:Dy films are grown on p+-type, p-type, and n-type Si(100) at a substrate temperature of 800° for 90 min. The doping concentrations of Dy atoms range from 1018 to 1019 cm-3 at the surface region of the film measured by the secondary ion mass spectrometry (SIMS). The particles with average size ~200 nm form at the surface of the film and it suggests the possibility to form Si-nanoparticle (Si quantum dots) from atomic force microscopy (AFM) observation. From the electrical measurements at room temperature, the metal (Al)-Si:Dy junction is a Schottky contact and Dy introduces donor states in Si.
Electron Spin Resonance in Magnetic Nanoparticles. Effects of Temperature and Interparticle Interactions
Authors: Noginova Natalia , Chen F. , Andreyev A. , McClure J. , Giannelis E. P. , Bourlinos A. B. , Atsarkin V. A.
Published: March 2017

The electron spin resonance technique has been applied to study the magnetization dynamics in broad temperature range in both concentrated magnetic fluid and diamagnetically diluted systems containing superparamagnetic maghemite nanoparticles. The ESR spectrum demonstrates an interesting double feature shape with a narrow peak near g=2, as well as “forbidden” resonances in low fields, and reveals strong dependence on temperature and nanoparticle concentration. The longitudinal spin-relaxation time was estimated. To describe the overall spectrum shape, a “quantization” model is used which involves summation of the resonance transitions corresponding to various orientations of the particle magnetic moment.
51V and 133Cs MAS NMR Investigation of Crystalline Trivanadate and Hexavanadate Phases.
Authors: Durupthy Olivier , Maquet Jocelyne , Steunou Nathalie , Bonhomme Christian , Livage Jacques
Published: March 2017

A complete solid state NMR characterization of the vanadium oxides Cs[V3O8] and Cs2[V6O16].0.7H2O is proposed. We used 51V and 133Cs MAS NMR to investigate the local environment of cesium and vanadium nuclei and 2D 1H- 133Cs CP MAS HETCOR experiments to explore the connectivities between cesium ions and water molecules in the interlamellar space.
Coverage Dependence of CO Surface Diffusion on Pt Nanoparticles - an EC-NMR Study
Authors: Wieckowski Andrzej , Kobayashi Takeshi , Babu Panakkattu K , Chung Jong Ho , Oldfield Eric
Published: March 2017

We have studied the effects of CO coverage on surface diffusion rates of CO adsorbed on nanoparticle Pt catalysts in sulfuric acid media by using 13C electrochemical nuclear magnetic resonance spectroscopy (EC-NMR) in the temperature range 253 - 293 K. For CO coverage from θ = 1.0 to 0.36, the diffusion coefficients follow Arrhenius behavior and both activation energy (Ed) and pre-exponential factor (Dco) show CO coverage dependence. Ed increases from 6.0 to 8.4 kcal/mol and DCO varies from 1.1 X 10-8 to 3.7 X 10-6 cm2/s when the coverage is increased from θ = 0.36 to θ = 1.0. On the Pt catalyst surface at partial CO coverage, our data strongly support the free site hopping model of adsorbed CO as the major surface diffusion mechanism, unlike the situation found with a fully CO covered surface where CO exchange between different surface sites is believed to be the major diffusion mechanism. Our results also indicate that the contributions of lateral repulsive interactions exert a stronger influence on the diffusive motion than does the nature of the surface structure. When the diffusion coefficient was estimated from CO stripping measurements by using an electrochemical modeling protocol, the estimated diffusion coefficients were a few orders of magnitude larger than those obtained from the EC-NMR experiments. Overall these results are important for improving our understanding of electrochemical surface dynamics of molecules at interfaces, and may help facilitate better control of fuel cell reactions where the presence of surface CO plays a crucial role in controlling the reaction rates.
BEBERAPA ASPEK EKOLOGI PERIKANAN DI RAWA TALIWANG. NUSA TENGGARA BARAT
Authors: Purnomo Kunto , Tjahjo Didik WahjuHendro
Published: March 2017

Rawa Taliwang adalah danau alami terbesar di Propinsi Nusa Tenggara Barat. Luasnya antara 584 sampai 913 ha dan kedalaman rata-rata sekitar 2 m. Permukaan perairannya hampir seluruhnya tertutup oleh tumbuhan air. Pada tahun 1990 produksi tangkapan ikan mencapai241,1 ton kemudian menurunmenjadi 36,9 ton pada tahun 1994. Studi apek ekologi perikanan di Rawa Taliwang dilakukan untuk mendapatkan data dan informasi tentang kondisi lingkungan perairan, potensi produksi perikanan, dan tingkat pemanfaatan sumber dayanya.
OPTIMASI PROSES PRODUKS| HTDROLTSAT PROTEIN IKAN (HPI) DARI MUJAIR (Oreochromrb mossambicusl
Authors: Ariyani Farida , Saleh M. , Tazwir Tazwir , Hak Nurul
Published: March 2017

Salah satu upaya untuk meningkatkan nilai tambah ikan bernilai ekonomis rendah adalah dengan memanfaatkannya menjadi hidrolisat protein ikan (HPl).
PENGARUH PEMBERIAN NATRIUM ALGINAT TERHADAP PENURUNAN KADAR KOLESTEROL TOTAL DARAH DAN BOBOT BADAN TIKUS
Authors: Wikanta Thamrin , Nasution R. R. , Rahayu Lestari
Published: March 2017

Penelitian tentang pengaruh pemberian natrium alginat terhadap penurunan kadar kolesterol total darah dan bobot badan tikus telah dilakukan.
KANDUNGAN LOGAM BERAT PADA KERANG DARAH (Anadara granosa), AIR LAUT DAN SEDIMEN Dt PERATRAN TANJUNG BALAIDAN BAGAN SIAPI-API
Authors: Murtini Jovita Tri , Yennie Yusma , Peranginangin Rosmawaty
Published: March 2017

Penelitian ini dilakukan di perairan Tanjung Balai dan Bagan Siapi-api. Di setiap lokasi diamati 6 stasiun pengamatan, 3 stasiun berjarak 1 mil dan 3 stasiun yang lain berjarak 2 mil dari garis pantai dan setiap stasiun pengamatan masing-masing berjarak 1 mil. Jenis contoh yang diamati adafah air faut, sedimen dan kerang darah (Anadara granosa).
ANALISIS PROFITABILITAS DAN DISTRIBUSI PENDAPATAN USAHA PENANGKAPAN IKAN MENGGUNAKAN PUKAT CINCIN MINI DI KABUPATEN TUBAN, JAWA TIMUR
Authors: Tajerin Tajerin , Manadiyanto Manadiyanto , Pranowo Sapto Adi
Published: March 2017

Keberhasilan usaha penangkapan ikan sebagai bagian sistem bisnis, tidak hanya dinilai dari profitabilitasnya juga keadilan dalam sistem distribusi pendapatan. Kajian terhadap kedua aspek tersebut pada usaha penangkapan ikan menggunakan pukat cincin mini telah dilakukan di Kabupaten Tuban dengan metoda survai.
INDEKS KEANEKARAGAMAN HAYATI IKAN KEPE-KEPE (Chaetodontidae) Dl PERAIRAN WAKATOBI, SULAWESI TENGGARA
Authors: Badrudin Badrudin , Sasanti Sasanti , Yahmantoro Yahmantoro , Suprihanto Lmam
Published: March 2017

Kelompok ikan yang dianggap sebagai indikator bagi baik-buruknya kondisi lingkungan perairan terumbu karang adalah Banyaknya jenis ikan kepe-kepe (Chaetodontidae) yang menghuni perairan karang tersebut . Data yang dianaliiis merupakan sebagian hasil penelitian dengan metode transek garis (line intercept trasect) yang dilaksanakan dalam rangka base line study Wakatobi. Penelitian dilakukan antara bulan September-Oktober 2001
Apixaban Pharmacokinetics at Steady State in Hemodialysis Patients
Authors: Mavrakanas Thomas A. , Samer Caroline F. , Nessim Sharon J. , Frisch Gershon , Lipman Mark L.
Published: March 2017

It is unclear whether warfarin is protective or harmful in patients with ESRD and atrial fibrillation. This state of equipoise raises the question of whether alternative anticoagulants may have a therapeutic role. We aimed to determine apixaban pharmacokinetics at steady state in patients on hemodialysis. Seven patients received apixaban 2.5 mg twice daily for 8 days. Blood samples were collected before and after apixaban administration on days 1 and 8 (nondialysis days). Significant accumulation of the drug was observed between days 1 and 8 with the 2.5-mg dose. The area under the concentration-time curve from 0 to 24 hours increased from 628 to 2054 ng h/ml (P<0.001). Trough levels increased from 45 to 132 ng/ml (P<0.001). On day 9, after a 2.5-mg dose, apixaban levels were monitored hourly during dialysis. Only 4% of the drug was removed. After a 5-day washout period, five patients received 5 mg apixaban twice daily for 8 days. The area under the concentration-time curve further increased to 6045 ng h/ml (P=0.03), and trough levels increased to 218 ng/ml (P=0.03), above the 90th percentile for the 5-mg dose in patients with preserved renal function. Apixaban 2.5 mg twice daily in patients on hemodialysis resulted in drug exposure comparable with that of the standard dose (5 mg twice daily) in patients with preserved renal function and might be a reasonable alternative to warfarin for stroke prevention in patients on dialysis. Apixaban 5 mg twice daily led to supratherapeutic levels in patients on hemodialysis and should be avoided.
Vertical and horizontal composition of fecal pollution indicator bacteria in lotic and lentic ecosystems at Turkish Thrace
Authors: Altinoluk-Mimiroglu Pinar , Camur-Elipek Belgin
Published: March 2017

Background and Purpose:Although freshwater ecosystems have natural bacterial populations, their distributions are negatively affected by agricultural activities, domestic and industrial discharges. Bacterial composition at different depths can limit the usage of the water column for drinking, irrigation or other intentions. This study was designed to give similar indications concerning the nature of distribution of indicator bacteria in two different freshwater ecosystem types (lotic and lentic biotopes), and also to identify the factors that might be responsible in shaping them.Materials and Methods:For this aim, stagnant and running water resources located in Meric-Ergene River Basin at Turkish Thrace were sampled at three water depths (surface, middle, bottom) and two sediment depths (shore and bottom) between the dates October 2014 and September 2015 at seasonal intervals. While the heterotrophic bacteria, total and fecal coliform bacteria, and Escherichia coli were recorded by the CFU and MPN techniques, some features (temperature, dissolved oxygen, pH, conductivity, salinity, nutrients, ions, and elements) were also measured by classical chemical, chromatographic or spectrometric methods.Results and Conslusions:According to the data, the bacterial distribution in each ecosystem was found as similar for the bottom and the surface water columns. Results were also supported statistically by Bray-Curtis similarity index and correspondence analyse. The relationships between the bacterial distribution and environmental features were evaluated by Spearman correlation index. Consequently, it was observed that the bacterial distribution can differ in both water column/sediment depths and lotic/lentic ecosystems. And, it was suggested that the middle water column in each ecosystem is the most proper column for human usage.
Overlay-independent comparisons of X-ray structures reveal small, systematic conformational changes in liganded acetylcholinesterase
Authors: Rohrer Jacqueline , Sidhom Morgana , Han Jingting , Radić Zoran
Published: March 2017

Background and Purpose: Comparisons of macromolecular 3D structures by minimizing corresponding atom RMSDs can by virtue of averaging, hide small unexpected deviations caused by ligand binding or site-directed mutagenesis. We developed an overlay-independent comparison approach and used it to compare selected, PDB structures of acetylcholinesterase (AChE; EC 3.1.1.7) in the apo state, in complexes with reversible ligands, in covalent conjugates or upon AChE mutagenesis. Methods: The active serine alpha carbon of the AChE monomer was used as a frame of reference for each of the structures, and distances calculated to remaining alpha carbons of the monomer backbone. Differences in distances at corresponding backbone positions from pairwise comparisons with apo-AChE structures were taken as a measure of changes in tertiary structures of liganded or mutant AChE monomers.Results: This analysis revealed small, yet significant backbone shifts in monomeric tertiary structures of AChEs. While reversible complexes with neurotoxin Fas2 showed global expansion of AChE monomer backbones, covalent conjugates at the active serine and high affinity reversible inhibitor hupA complexes revealed backbone compression towards the active serine. In some of AChE homodimers 0.6 - 1Å shifts of monomer backbone affected crystallographic quaternary structures by causing significant, up to seven degree tilts in monomers, relative to angles measured in the apo-AChE.Conclusions: Small but systematic differences detected in tertiary structures of liganded or mutagenized AChEs appear consistent with larger magnitude alterations of several AChE homodimer quaternary structures. Those observations vaildate our overlay-independent approach for detecting small, yet significant, tertiary backbone shifts in macromolecular 3D structures.
Mean resistive index as a prognostic tool for hydronephrosis in patients with acute renal colic: a study in a tertiary care
Authors: Ravindernath M. L. , Reddy G. Mahender
Published: March 2017

Background: Uretolithiasis is one of the most common cause of urinary tract obstruction which leads to the admission into the emergency ward. The detection of urolithiasis or acute renal colic is by the radiography, conventional ultrasonography (US) and intravenous urography (IVU). A colour Doppler USG measures this change as a resistive index (RI) of the arcuate arteries at the corticomedullary junction or the interlobar arteries.Methods: 84 patients between the ages 15-50 years, who were admitted to the Emergency department of our hospital with unilateral renal colic were included into our study. Detailed demographic data was collected from all the patients and they were all subjected to a thorough physical and clinical examination. Bladder ultrasound was taken along with color Doppler for all the patients at the time of admission for every 6 hours. Thus, an increased RI index signifies an obstruction without a dilatation.Results: Left flank pain was slightly more than the right flank pain, although this was not found to be significant. Most of the patients were presented with vomiting or nausea and dysuria was seen in 48 patients. there were 41 cases of hydronephrosis in total and all of them were positive for mean RI. The specificity with the mean resistive index with color Doppler was 90%, while the sensitivity was 100%.  Around 95% of the prediction was accurate with mean resistive index, with more than 90% efficiency.Conclusions: The mean resistive index is a very good tool for the diagnosis of hydronephrosis, with a very high level of specificity and sensitivity.
Role of procalcitonin and C-reactive protein in urinary tract infection diagnosis in adults
Authors: M. S. Bharath , Hiremath Ramesh S. , Basu Arini
Published: March 2017

Background: Urinary tract infections are a common group of infections encountered in adults, and their treatment and prognosis are closely correlated with the location of infection. Clinical presentation and laboratory tests are insufficient to differentiate between upper urinary tract infection and lower urinary tract infection. So this study was conducted to explore a non-invasive diagnostic method for upper and lower urinary tract infection differentiation.Methods: A case-control study included 2 groups of patients –30 cases and 30 controls. Cases further classified into 2 groups- a) Patients having upper urinary tract infection; b) Patients having lower urinary tract infection. Patients were subjected to following tests – complete hemogram, blood C-reactive protein levels, serum procalcitonin levels, urinalysis, ultrasound abdomen.Results: Procalcitonin (PCT) and CRP values with upper urinary tract infection were significantly higher than those in with lower urinary tract infection. PCT has higher -sensitivity and a specificity than CRP.Conclusions: Both procalcitonin and CRP can be used for upper and lower urinary tract infection differentiation, but Procalcitonin has higher sensitivity and specificity in predicting Upper urinary tract infection than CRP.
To study cardiac manifestations in patients presenting with dengue infection and to find out the correlation of cardiac manifestations to warning signs of dengue
Authors: Yadav Rakesh Kumar , Kumar Sujit
Published: March 2017

Background: This study was done to observe the presence of Electrocardiographic (ECG) changes in patients presenting with dengue infection and to evaluate whether there were any related clinical cardiac manifestations and to find out the correlation of cardiac manifestations to warning signs of dengue.Methods: The study was conducted at MLN Medical College, Allahabad in the Department of Medicine between July 2016 to December 2016. One hundred consecutive patients aged 18 years or more with positive dengue serology were interviewed and examined. ECG was done for all patients. The data was analyzed using statistical significance tests.Results: Thirty-six patients had no warning signs, 64 patients had warning signs, out of which 43 patients had two or more warning signs while 21 patients had single warning sign. Most common warning sign in this study was abdominal pain (50%) and Vomiting (45 %) while hepatomegaly was the least common warning sign. The most common cardiac abnormalities noted were rhythm abnormalities of which the commonest was sinus bradycardia, found in 60 percent. There was statistically significant correlation between cardiac manifestations and all the warning signs except lethargy/restlessness and hepatomegaly.Conclusions: The most common cardiac manifestations noted were transient rhythm abnormalities, of which sinus bradycardia was the commonest. There was no evidence of myocarditis in any of the patients. There was statistically significant correlation between cardiac manifestations and all the warning signs except lethargy/restlessness and hepatomegaly.
Religious-Based Conflicts through the Academic Dialogue
Authors: Cook Mongan
Published: March 2017

Religious-based conflicts in democratic states have been a subject of academic deliberation within a vast number of fields. The following chapter attempts to sort out the different questions generated by such conflicts, to analyze the primary method offered to diffuse them and its shortcomings, and to explain why specific characteristics of the legal system can be utilized as reconciling mechanisms for such conflicts.
Design and Analysis of Folded Cascoded Operational Trans Conductance Amplifier
Authors: Kumari Namika
Published: March 2017

This paper presents an optimized methodology to folded cascode operational transconductance amplifier (OTA) design. In this design all the CMOS are in saturation region in order to optimize MOS transistor sizing. Using 0.18μm CMOS process, a fully differential folded cascode architecture has been proposed which attains the DC gain of 67.5Db, a unity-gain frequency of 500MHz, power dissipation is 125.56 µW, Phase Margin is 170degree, CMRR is 127.6dB and slew rate is 27.4 V/µs.
The Effect of Portfolio-Based Assessment on EFL Students Writings and Process Writing
Authors: Mtawaa Jamel Ben Youssef
Published: March 2017

Sharifi and Hassaskhah (2011) set out to investigate the impact of portfolio assessment techniques on the overall quality of students' writing. The population of the study included 20 university students in a time interval extending over one semester at the University of Guilan, Iran. In this review I'm going to summarize this study in terms of its research design and the results reached by the researchers. The two dimensions of this research will then be discussed in terms of their descriptive power, explanatory adequacy and external validity.
A mediação no processo de alfabetização e letramento das crianças que apresentam dificuldade no Ensino Fundamental I
Authors: Rodrigues Dieine Colares Pereira , Silveira Zélia Medeiros
Published: March 2017

A presente pesquisa aborda a importância da mediação no processo de alfabetização e letramento das crianças que apresentam dificuldade nas turmas de 3º ano do Ensino Fundamental I. Para realizar esta análise dialogamos com os autores que discutem as concepções de ensino e aprendizagem, dificuldade e o processo de alfabetização e letramento. Além do estudo teórico, foi realizada também uma pesquisa de campo por meio de uma entrevista semiestruturada, com 5 (cinco) professoras de 4 (quatro) escolas da rede municipal de ensino de Sombrio/SC. Os resultados da pesquisa apontam que as professoras não compreendem o que é mediação e sua importância no processo de alfabetização e letramento de forma clara. Essa falta de compreensão prejudica a mediação dos conhecimentos com as crianças que apresentam dificuldade nesse processo.PALAVRAS-CHAVE: Mediação. Processo de alfabetização e letramento. Dificuldade
As ações pedagógicas utilizadas por uma professora da EJA em uma escola no município de Criciúma
Authors: Lopes Michele Alves de Souza , Hanoff Mirozete Iolanda Volpato
Published: March 2017

Este artigo traz como objeto de estudo investigar características da prática pedagógica docente realizada em uma escola da EJA pertencente à rede municipal de Criciúma-SC. Para isso, realizamos uma revisão da literatura utilizando teóricos que escrevem sobre os temas. Como procedimentos foram utilizados, a observação da escola e de aulas e entrevistas semiestruturadas com uma professora e oito alunos. Os resultados obtidos revelaram que apesar dos avanços nas políticas públicas, a Educação de Jovens e Adultos ainda é uma modalidade de ensino relegada a segundo plano. Nessa modalidade a docentes cujas práticas observamos, não estão em consonância com os dispositivos legais e orientações metodológicas expressos em documentos oficiais, evidenciando insuficiências nas formas de organização do ensino para essa modalidade.PALAVRAS CHAVE: Educação Jovens e Adultos. Prática Pedagógica. Ensino Aprendizagem.
Iniciação à docência: experiências formativas do professor pesquisador no PIBID Pedagogia/UNESC
Authors: Tanchela Stefani , Camargo Gislene
Published: March 2017

Tendo como tema o Programa Institucional de Bolsa de Iniciação à Docência (PIBID) e os professores pesquisadores, o presente artigo tem como objetivo analisar a contribuição do Programa na formação do professor pesquisador no curso de Pedagogia da Universidade do Extremo Sul Catarinense (UNESC), o qual foi definido a partir do seguinte problema de pesquisa: o PIBID/Pedagogia-UNESC contribui para a formação do professor pesquisador? Fundamentado em uma pesquisa bibliográfica, com abordagem qualitativa, o estudo utilizou um questionário com perguntas abertas como técnica de coleta de dados. O referencial teórico investiga a presença do professor pesquisador nos documentos do PIBID e caracteriza o professor pesquisador. Participaram da pesquisa seis alunas do curso de Pedagogia, integrantes do PIBID entre um ano e mais de dois anos. Os resultados do questionário demonstram que as participantes reconhecem o valor da pesquisa para sua formação pessoal e profissional e, pelo incentivo do PIBID à pesquisa, já produziram e divulgaram artigos em diversos eventos científicos. Dessa forma, a presente pesquisa justifica-se por acrescentar um olhar sobre a importância de projetos voltados à pesquisa na formação docente.PALAVRAS-CHAVE: PIBID. Pedagogia. Pesquisa. Formação docente.
Rusnano i Skolkovo – czołowe rosyjskie przedsięwzięcia na drodze do innowacji
Authors: Wdzięczak Janusz
Published: March 2017

W artykule zaprezentowano zagadnienia związane z rozwojem rosyjskiej gospodarki opartej na innowacji, a także rolę, jaką odgrywa państwo we wspieraniu rozwoju innowacji. Dokonano tego na przykładzie dwóch inicjatyw: Skolkovo i Rusnano, a także przeprowadzono próbną ocenę efektywności tych działań.
Gender Pay Gap in Poland
Authors: Oczki Jarosław
Published: March 2017

The aim of the article is to investigate the actual and explained gender pay gaps in Poland in comparison with selected highly developed countries, and to discuss the factors determining wage disparities between men and women. Data from Eurostat EU-SILC and the International Labour Organization were used. The article concludes that the gender pay gap in Poland is relatively small and decreasing, and that estimates of the explained gender pay gap published by the International Labour Organization do not consider the influence of some important variables shaping wages.
A fuzzy model for the evaluation of suppliers of material resources to machine-building enterprises
Authors: Kozlova Evgeniya , Volynsky Vladimir
Published: March 2017

The subject of our research is the process of selecting a supplier of material resources to machine-building enterprises. The aim of this work is to identify factors that improve the process of supplier selection of material resources to large enterprises. Testing this model is made on the example of the “KRANEKS” machinebuilding enterprise. The methodological basis of the scientific research is work in the fields of systems analysis, management accounting, and econometrics. As a result of the research, a methodology and estimation algorithm of suppliers was developed, as well as a hierarchical model of fuzzy inference to supplier evaluation. These developments are mainly aimed at supporting decision making in choosing the best provider for a machine-building enterprise. These developments mainly focused on decision support in choosing the best provider for an engineering enterprise whose list of material resources runs into the thousands. They are aimed at improving the efficiency of administrative decisions in the supplier selection process of machine-building enterprises and improving the work process of their purchasing departments.
Międzynarodowa pozycja inwestycyjna netto krajów Unii Europejskiej w latach 2006–2014
Authors: Maciejczyk-Bujnowicz Iwona
Published: March 2017

Celem opracowania jest próba ocenienia zmian, jeśli chodzi o międzynarodową pozycję inwestycyjną netto45w krajach Unii Europejskiej w latach 2006–2014 w kontekście przestrzegania zaleceń w ramach ogłoszonej procedury zakłóceń makroekonomicznych. W niniejszej pracy dokonano przeglądu najważniejszych koncepcji teoretycznych, będących punktem wyjścia dalszych rozważań. W tym celu przeanalizowano literaturę przedmiotu oraz dane statystyczne dotyczące międzynarodowej pozycji inwestycyjnej krajów w latach 2006–2014. Na tej podstawie spróbowano ocenić współczesne tendencje dotyczące salda netto MPI w UE. W krajach UE występują znaczące różnice w przepływach kapitału mierzonego międzynarodową pozycją netto. Wybuch kryzysu w 2008 r. wywołał zmiany w tendencji w kształtowaniu się struktury kapitału w MPI. W okresie 2006–2014 następuje wzrost absolutnych wartości aktywów oraz pasywów MPI. W większości krajów UE pogłębia się ujemne saldo przepływów finansowych międzynarodowej pozycji inwestycyjnej względem PKB badanych krajów.