bluuebunny/crossref_metadata_2025 huggingface dataset:
Demographic factors and associated anomalies in fetuses with neural tube defects
Authors: Kitova Tanya , Milkov Denis , Kitov Borislav , Kilova Kristina , Gaigi Soumeya
Published: December 2013

The aim of this study was to identify the types of abnormalities associated with neural tube defects (NTDs) and the magnitude of the risk for their expression under the influence of the following factors: maternal age >35 years, consanguinity and season of conception. One hundred and fifty fetuses were autopsied during the period 2006–2009 at the Center for Maternity and Neonatology, Tunisia. A mother’s age of >35 years increases the probability of intrauterine growth retardation by two-fold [odds ratio (OR) 2.043, confidence interval (CI) 0.880–4.741]. Consanguinity increases the relative risk for abnormalities in the facial shape (OR 3.031, CI 1.279–7.183) and adrenal hypoplasia (OR=2.787, CI 1.140–6.814). The autumn-winter period of conception increases the relative risk for the expression of cleft palate by more than nine times (OR 9.035, CI 1.161–70.258) and by about three times for abnormalities of the excretory tract (OR 2.935, CI 0.954–9.141). The prenatal ultrasound diagnosis of NTDs with risk factors such as maternal age >35 years, consanguinity and conception during the autumn-winter period should be targeted to the search for lower-than-normal fetal weight and abnormalities of the excretory tract and the adrenal glands. The head should be examined with special care for deviations in the cranial perimeter and cleft palate.
Investigating a Natural Plant-Based Bio Binder and Cement Dust Mix as a Bitumen Substitute in Flexible Pavements
Authors: Abdel Warith Karim A. , Khedr Safwan A.
Published: December 2013

Bitumen use in flexible pavements is energy intensive and is associated with many environmental concerns. A natural organic binder, Agmin, which is both renewable and cheap, was investigated in combination with cement dust as a substitute for bitumen. This paper highlights the preliminary results of this investigation. An experimental program was set up that included Marshall and Superpave testing procedures. Marshall stability and flow, rutting susceptibility, and resilient modulus were among the parameters measured for Agmin–cement dust mixes. Samples were subjected to heat cycles as part of their durability assessment. The results of this investigation indicate that Agmin–cement dust road mix displays greater stability than unmodified asphalt mixes and is less susceptible to rutting. It is also relatively unaffected by temperature changes.
Schnelle optische Drallmessung
Authors: Hertzsch Albrecht , Kröger Knut , Großmann Marko
Published: December 2013

Um die Dichtheit einer drehenden Welle ohne Leckage oder Trockenlaufen
sicherzustellen, muss die Wellenoberfläche im Dichtungsbereich
drallfrei sein. Drall ist eine Oberflächenstruktur, die die Rauheit
der Wellenoberfläche wie eine mikroskopische Schraubenstruktur
überlagert und somit zu einem Öltransport führt. Schneidet man die
Drallstruktur in axialer Richtung, so besitzt sie die Form einer
periodischen Welligkeit. Durch angepasste kohärente Beleuchtung der
Wellenoberfläche kann die Drallstruktur im reflektierten Licht
deutlich visualisiert werden. Der angepasste Beleuchtungsprozess wirkt
wie ein optischer Filter, der das optische Rauschen der
Rauheitsstrukturen im reflektierten Streulicht reduziert und die
Lichtbeugung an der Drallstruktur verstärkt anregt. Es entsteht
innerhalb der reflektierten Streulichtverteilung ein deutliches
Beugungsmuster. Mit Hilfe eines rigorosen Beugungsmodells berechnen
wir die gemessenen Beugungseffizienzen in bester Näherung und
bestimmen somit die Periodenlänge und Dralltiefe der
Drallstruktur. Wir stellen ein Streulichtmessgerät vor, das schnell
und reproduzierbar Drallstrukturen auf Wellenoberflächen
ermittelt. Anhand von produktionstypischen Wellenoberflächen mit
unterschiedlichen Drallstrukturen testen wir diese optische
Drallmessung und vergleichen die Ergebnisse mit taktilen Messungen. Es
werden die Grenzen des optischen Messverfahrens diskutiert und die
zukünftigen Entwicklungsschritte aufgezeigt.
Multi-Scale Simulation of Transport via a Mo/n+-GaAs Schottky Contact
Authors: Aldegunde Manuel , Hepplestone Steven P. , Sushko Peter V. , Kalna Karol
Published: December 2013

A multi-scale modeling of electron transport via a metal-semiconductor interface is carried out by coupling ab initio calculations with three-dimensional finite element ensemble Monte Carlo simulations. The results for the Mo/GaAs (001) interface show that variations of the electronic properties with the distance from the interface have a strong impact on the transport characteristics. In particular, the calculated tunneling barrier differs dramatically from that of the ideal Schottky model of an abrupt metal-semiconductor interface. The band gap narrowing near the interface lowers resistivity by more than one order of magnitude: from 2.1×10-8 Ωcm² to 4.7×10-10 Ωcm². The dependence of the electron effective mass from the distance to the interface also plays an important role bringing resistivity to 7.9×10-10 Ωcm².
Mott-memories Based on the Narrow Gap Mott Insulators AM4Q8 (A=Ga, Ge ; M = V, Nb, Ta ; Q = S, Se)
Authors: Cario L. , Janod E. , Tranchant J. , Stoliar P. , Rozenberg M. , Besland M.-P. , Corraze B.
Published: December 2013

The narrow gap Mott insulators AM4Q8 (A = Ga, Ge; M= V, Nb, Ta; Q = S, Se) exhibit very interesting electronic properties when pressurized or chemically doped. We have recently discovered that the application of short electrical pulses on these compounds induces a new phenomenon of volatile or nonvolatile resistive switching. The volatile transition appears above threshold electric fields of a few kV/cm, while for higher electric fields, the resistive switching becomes non-volatile. The application of successive very short electric pulses enables to go back and forth between the high and low resistance states. All our results indicate that the resistive switching discovered in the GaM4Q8 compounds does not match with any previously described mechanisms. Conversely, our recent work shows that the volatile resistive switching is related to a purely electronic mechanism which suggests that the AM4Q8 compounds belong to a new class of Mott-memories for which Joule heating, thermochemical or electrochemical effects are not involved. Finally, it is possible to deposit a thin layer of GaV4S8 and to retrieve the reversible resistive switching on a metal-insulator-metal (MIM) device which proves the potential of this new class of Mott-memories for applications.
Effects of VUV and EUV Radiation on Ultra Low-k Materials Damage
Authors: Braginsky Oleg , Kovalev Alexander , Lopaev Dmitry , Mankelevich Yury , Proshina Olga , Rakhimova Tatyana , Rakhimov Alexander , Vasilieva Anna , Zyryanov Sergey , Baklanov Mikhail
Published: December 2013

Low-k dielectric films can be substantially damaged during plasma processing. High energy UV and VUV photons emitted by plasma play the key role in damaging the porous low-k films directly or indirectly by stimulating chemical reactions with radicals in plasma and plasma afterglow. The different ULK samples (k: 2.0-2.2, porosity: 30-50%, pore radius: 1-2 nm) were studied by exposing to five radiation sources at various wavelengths (VUV: 193 nm, 147 nm, 104-106 nm, 58.3 nm, and EUV: 13.5 nm). Time-spatial behavior of the ULK damage as a function of photons fluence was studied by FTIR spectroscopy and XRF analysis. It is shown that the degree of damage depends on wavelength of UV light. The major UV damage was observed at the wavelengths below 193 nm. The maximum damage corresponds to 147 nm while the degree of damage at 58.3 nm was much smaller. In the case of organosilicate (OSG) based ULK materials, the degree of damage, as a rule, increases with porosity. Organic low-k materials are damaged more than OSG at 193 nm, but at shorter wavelengths (147, 106, 58.3 and 13.5 nm) they are more stable than OSG. One-dimensional model for radiation absorption and dynamics of CH3 group destruction in ULK films was developed. The cross-sections of photons absorption and photo-stimulated Si-CH3 bond breaking in ULK films for 13.5 -147 nm wavelength range were derived from a combined experimental and modeling study. The obtained values allow to simulate the VUV/EUV induced modifications of low-k materials with different composition, to understand better the mechanisms of plasma damage and to generate ideas for controllable modifications of low-k materials.
Performance and Reliability of Thick Cu Interconnects for RF and Analog/Mixed Signal Technology
Authors: Cooney E. , Gambino J.P. , Anderson F. , He J. , Lee T. , White E. , Liu X. , Cabral C. , Shaw T.
Published: December 2013

Wireless communications such as those in cell phones are utilizing increasing chip design complexity. For example analog mixed-signal chips can contain RF capability which requires integrated inductors [1,2]. High performance RF designs are enabled by the use of thick Copper (Cu) and Aluminum (Al) wires (>3um). In particular, the quality factor of the inductor, which is the ratio of magnetic stored energy over average dissipation, is dependent on the metal thickness. High quality factors, can be achieved by using thick Cu inductors. In some applications, the total thickness of Cu in the inductor can be as much as 12 um.

The fabrication of thick Cu layers is in many ways easier than that of thin Cu layers. For example, there are no limitations in terms of lithography or liner and seed layer thickness. However, there are still challenges with fabrication due to stress. Cracking of the dielectric can occur, due to the mismatch in coefficient of thermal expansion between Cu and SiO2, and due to the thick Cu layers in the inductor stack. Both the layout and the processing must be optimized to ensure that cracking does not occur.

This paper will discuss current applications, inductor design, and the reliability challenges and solutions associated with thick Cu interconnects.
Sealing of low-k dielectric (k=2.0) with self-assembled monolayers (SAMs) for the atomic layer deposition (ALD) of TiN
Authors: Sun Yiting , Levrau Elisabeth , Blauw Michiel , Meersschaut Johan , Verdonck Patrick , Struyf Herbert , Detavernier Christophe , Baklanov Mikhail , De Feyter Steven , Armini Silvia
Published: December 2013

In this work, a novel low dielectric constant (low-k) pore sealing approach was engineered by depositing firstly a sub-2 nm SAMs and then a 3 nm TiN barrier film. The low-k film was pretreated by plasma to introduce hydroxyl groups onto the surface, followed by SAMs deposition. Then a TiN film was deposited from tetrakis(dimethylamino)titanium (TDMAT) via ALD as a dielectric barrier. Penetration of Ti atoms into low-k was measured and used to evaluate the sealing ability of SAMs. For the samples covered with SAMs, around 90% reduction of Ti atoms penetration was achieved. The pore radius was reduced to below 0.5 nm after the barrier deposition. The ∆k after pretreatment and after SAMs are 0.1 and 0.16, respectively.
Leveraging Contact Effects for Field-Effect Transistor Technologies with Reduced Complexity and Superior Current Uniformity
Authors: Sporea R. A. , Georgakopoulos S. , Xu X. , Guo X. , Shkunov M. , Shannon J. M. , Silva S. R. P.
Published: December 2013

In order to achieve high performance, the design of devices for large-area electronics needs to be optimized despite material or fabrication shortcomings. In numerous emerging technologies thin-film transistor (TFT) performance is hindered by contact effects. Here, we show that contact effects can be used constructively to create devices with performance characteristics unachievable by conventional transistor designs. Source-gated transistors (SGTs) are not designed with increasing transistor speed, mobility or sub-threshold slope in mind, but rather with improving certain aspects critical for real-world large area electronics such as stability, uniformity, power efficiency and gain. SGTs can achieve considerably lower saturation voltage and power dissipation compared to conventional devices driven at the same current; higher output impedance for over two orders of magnitude higher intrinsic gain; improved bias stress stability in amorphous materials; higher resilience to processing variations; current virtually independent of source-drain gap, source-gate overlap and semiconductor thickness variations. Applications such as amplifiers and drivers for sensors and actuators, low cost large area analog or digital circuits could greatly benefit from incorporating the SGT architecture.
Simulation of Millisecond Laser Anneal on SOI: A Study of Dopant Activation and Mobility and its Application to Scaled FinFET Thermal Processing
Authors: Michalak Tyler J , Borst Chris , Franca Dan , Herman Josh , Rodgers Martin
Published: December 2013

This work investigates scanning laser annealing used for ultra-shallow junction (USJ) activation. We investigate the laser system via simulation to determine the peak temperature achieved in the active area during processing. We employed the Sentaurus TCAD software by Synopsys to perform a 2D simulation of a laser scans across the active area of the device, solving the heat equation in both time and space. An absorber layer is deposited on the wafer surface to enhance the absorption of incident energy and reduce SOI reflectivity. An effective absorption coefficient of α=8000cm-1 was calculated for the absorber layer, calibrated with the experimental laser intensity. This absorption coefficient correctly predicts the silicon temperature as a function of power with any arbitrarily defined scan speed. To investigate the role of dopant activation, an SOI wafer was implanted with arsenic 25 keV, dose 3e15 /1.5e15 cm-2 and laser annealed in areas of target temperatures ranging from 850-1300°C. The sheet resistance was measured using 4-point probe showing sheet resistance improvement with increasing laser temperature. The extracted temperature cycle from the 2D heat simulation was used as an equivalent millisecond RTA in a full 3D process simulation to study dopant distribution and activation using Sentaurus Process Kinetic Monte Carlo (KMC), considering the effect of dopants, dopant clusters, and point defects. The results of this simulation demonstrate deactivation of arsenic above 1050°C, which is inconsistent with Hall measurements that suggest increasing laser temperature will increase mobility and activation. The results are analyzed versus the expected trends and suggest future improvements needed to the KMC model or the laser temperature profiles in order to describe activation kinetics in millisecond anneals within SOI.
Exposure Light Wavelength Effects on Charge Trapping and Detrapping of nc-MoOx Embedded ZrHfO High-k Stack
Authors: Liu Xi , Kuo Yue , Yuan Tao
Published: December 2013

The influence of the red and green LED light exposure on the memory function of the nanocrystalline MoOx embedded ZrHfO high-k gate dielectric has been investigated. Since the performance of the device is mainly dependent on the hole trapping and detrapping mechanisms, the light exposure affects the hole generation, transfer, and storage to and in the dielectric structure. Both the charge storage capacity and the leakage current were increased from the light exposure. The Coulomb blockade phenomenon in the leakage current density vs. gate voltage curve disappears under the light exposure condition. The light exposure effect is potentially important for practical application of the device.
A 3D Soft-EHL Model for Simulating Feature-scale Defects in Advanced Node ICs
Authors: Sierra-Suarez Jonatan A. , Srivastava Gagan , Higgs C. Fred
Published: December 2013

A new multiphysics, multiscale framework is presented which is capable of capturing and predicting both wafer-scale and feature-scale defects. Through physics-based modeling, the empirical wear/Preston coefficient often found in popular feature scale models has been eliminated. Simulation results show the topography evolution of an actual metal 1 layout between two dies located in different positions on a wafer during the CMP process.
Low-Contact-Resistance Contacts to Graphene via Metal-Mediated Etching
Authors: Leong Wei Sun , Thong John T.L.
Published: December 2013

The theoretically-predicted enhancement of metal-graphene contacts using the “end-contacted” configuration is studied. Graphene edges at the source/drain regions are created via a CMOS process compatible metal-assisted etching technique. The on-resistance of a graphene device with cobalt-etched-graphene contacts shows 6 times improvement compared to pristine graphene device. Apart from that, four-point contacted graphene devices with nickel-etched-graphene contacts were fabricated and tested under ambient conditions. The proposed graphene devices exhibit contact resistance as low as 14 Ωμm, with an average of 90 Ωμm. Thus, forming metal-etched-graphene contacts is a promising method to obtain low-contact resistance metal contacts to graphene.
Atomic Model of CdSe QDs Containing Density Waves as Derived from PDF Analysis
Authors: Palosz B. , Palosz W. , Wijewarnasuriya P. , Gierlotka S. , Skrobas K. , Stelmakh S.
Published: December 2013

Using a new methodology of elaboration of PDF data (G(r) function), which is based on the analysis of individual inter-atomic distances (ri), a function describing differences between average inter-atomic distances in CdSe nanograins derived experimentally and those in the parent bulk crystal was determined. Based on that methodology a unique atomic architecture of CdSe QDs is proposed. The results show that a good knowledge about the grain surface of nanocrystals alone may be insufficient for understanding the nanomaterials properties, and that the real atomic structure of the interior of nanograins is of importance as well.
A New Solution to the Ni-fill issue for Silicide-last Process
Authors: Mao Shu J. , Zhao Li C. , Luo Jun. , Yan Jiang.
Published: December 2013

Metal Nickel(Ni) fill becomes the challeng in integrating silicide-last process into CMOS advanced technology with further contact size scaling. In this work, the specific contact resistivity (ρc) of cold titanium(Ti)/Si was investigated by the cross-bridge Kelvin resistor(CBKR) method and compared with that of Ni(Pt)Si/Si. The cold Ti/n+-Si showed comparable contact resistance(ρc∼3x10-8Ω·cm2) to Ni(Pt)Si/ n+-Si, while a larger ρc(7.5x10-1Ω·cm2) for cold Ti formed on B+ doped Si substrates. The cold Ti/Si interface was also discussed. Our results furnish a fresh perspective on the solutions to the metal fill challeng for silicide-last process.
Al CMP for Low Resistance Gate Fill for 20nm and Beyond Replacement Metal Gate
Authors: Economikos Laertis , Zhang Xing , Hwang Haigou , Kwon Unoh , Wong Keith , Escarabajal Yann , Lagudu Uma R. K. , Chockalingam Ashwin , Babu S.V.
Published: December 2013

Aluminum (Al) gate fill has been implemented in Replacement Metal Gate (RMG) due to its low resistivity. Titanium (Ti) has been widely used as wetting layer for Al to fill the gates. For low resistance gate fill in structures with small feature size and high aspect ratio, Ti-Al metal fill becomes increasingly more challenging as we move from 20nm into 14nm FinFET and 3D type structures.

Cobalt (Co) is a good wetting film for Al with better fill performance and lower resistance than Ti-Al based process. However, due to the difference in corrosion potential between Al and Co, Chemical Mechanical Planarization (CMP) creates pitting type defects on Al-Co film that increases resistance variability across pattern density. CMP induced corrosion is separated in two parts; first is the static Co corrosion happened in the acidic chemical environment in the Al slurry. Second is the galvanic corrosion from Co-Al metal boundary due to high metal electrical potential. Static corrosion can be resolved by adding a Co corrosion inhibitor in the slurry formulation1. Galvanic corrosion can be minimized by controlling Co thickness deposition and formation of complete intermetallic phase. By controlling the removal rate with respect to corrosion rate we were able to suppress corrosion significantly.

We looked into compositions where the corrosion potential (Ecorr) gap between Al and Co is reduced to ≤10mV leading to reduced galvanic currents. Stabilization of the corrosion currents in both Al and Co was observed using potentiodynamic scans. The effect of pH, several oxidizers and additives on the open circuit potentials (Eoc) of Al and Co was investigated and it was found that solutions of KMnO4, saccharides and sulfonate group containing compounds help reduce the Ecorr gap in between Al and Co to ∼10 mV.

Controlling the Al gate height across pattern densities and gate lengths to within few nm is another challenge for Al CMP. The industry widely used approach is to clear all Al using a slurry with high selectivity to dielectric, followed by a CMP step using a non-selective Al-to-oxide slurry. Both polishing steps need to be optimized in parallel in order to remove the incoming spacer SiN divot, minimize Al loss on gates with high pattern density or long gate length, minimize oxide loss on large open areas while maintaining low defectivity.

In this paper we are presenting an innovate Al CMP process that demonstrated low gate resistance with tight distribution up to 80% pattern density. This work has been supported by the independent Bulk CMOS and SOI technology development projects at the IBM Microelectronics Division Semiconductor Research & Development Center, Hopewell Junction, NY 12533.
Modeling of “Pad-in-a-Bottle”: A Novel Planarization Process Using Suspended Polymer Beads
Authors: Fan Wei , Johnson Joy , Boning Duane S.
Published: December 2013

The “pad-in-a-bottle” (PIB) approach to planarization is a non-traditional chemical mechanical polishing (CMP) process in which slurry containing polymer beads is used. The approach is hypothesized to be able to perform polishing by mixing polymer beads with similar chemical and mechanical properties as pad asperities into the slurry to provide force application and polishing contacts, so that a traditional CMP pad is not needed. Pad-in-a-bottle could provide predictable and controllable mechanical contacts through bead size control, which could substantially reduce process variability. Pad-in-a-bottle also has the potential to reduce the CMP consumable cost. In this work, we propose a physical model to understand the behavior of the pad-in-a-bottle approach and estimate the relationship of applied pressure and material removal rate in this variant of CMP. Two specific cases of polymer bead formation are considered in our modeling work, bead packing and bead stacking. Model prediction shows that the two bead formation cases generate distinctly different polishing mechanisms: material removal is applied pressure driven in bead packing, but contact event driven in bead stacking. The physical model suggests that in future experiments or applications of pad-in-a-bottle, a polymer bead size distribution or shape variation may be needed to achieve efficient material removal.
Characterization of chemically modified thin films for optimization of metal CMP applications
Authors: Basim G. Bahar , Karagoz Ayse , Ozdemir Zeynep
Published: December 2013

Metal CMP applications necessitate the formation of a protective oxide film in the presence of surface active agents, oxidizers, pH regulators and other chemicals to achieve global planarization. Formation and mechanical properties of the chemically modified metal oxide thin films in CMP determine the stresses develop at the interfaces delineating the stability and protective nature of the chemically altered films on the surface of the metal wafer. The balance between the stresses built in the film structure versus the mechanical actions provided during the process can be used to optimize the process variables and furthermore help define new planarization techniques for the next generation microelectronic device manufacturing. In this study, the preliminary studies were concentrated on the very well established tungsten CMP applications and furthermore, titanium CMP applications were presented as a part of surface nano-structuring methodology for biomedical applications by stressing the synergistic effect of protective metal oxide film of titanium in this advanced application.
Development of intelligent pad and application to analysis of pressure distribution on polishing pad in CMP process
Authors: Kinoshita Masaharu , Park Jaehong , Jeong Haedo
Published: December 2013

Most of polishing conditions are not consistent during the polishing process such as pressure, velocity, temperature, pad surface asperity and slurry flow which determine the CMP performance. Traditionally, these parameters are detected by various monitoring methods on CMP polisher. This study introduces a new concept of intelligent pad system with multiple sensors and peripheral devices such as memory, CPU, battery, transmitter and so on. The main functions of the intelligent pad are sensing the change of major parameters and data processing in real-time during the polishing process. The developed intelligent pad has nine points of embedded pressure sensor and makes data processing, saving, and transmitting in real-time. Experimentally, the intelligent pad system was evaluated to understand carrier behavior and pressure distribution. Finally, the analysis of pressure distribution using the intelligent pad turned out a useful method to understand the polishing head behavior and the polishing profile.
Genesis of textural contrasts in subsurface soil horizons in the Northern Pantanal-Brazil
Authors: Nascimento Alexandre Ferreira do , Furquim Sheila Aparecida Correia , Couto Eduardo Guimarães , Beirigo Raphael Moreira , Oliveira Júnior Jairo Calderari de , Camargo Plínio Barbosa de , Vidal-Torrado Pablo
Published: December 2013

The Pantanal region can be characterized as a quaternary floodplain with predominant sedimentation in the form of alluvial fans. In the geomorphologic and sedimentary evolution, the avulsion process is inherent to this depositional system and its dynamics, together with surface water floods, influence soil sedimentation on this plain. The knowledge and differentiation of these two events can contribute to a better understanding of the variability of soil properties and distribution under the influence of these sedimentation processes. Therefore, this study investigated the genesis of soils in the Northern Pantanal with textural contrasts in deeper horizons and their relationship with the depositional system dynamics. We analyzed four soil profiles in the region of Barão de Melgaço, Mato Grosso State, Brazil (RPPN SESC Pantanal). Two profiles were sampled near the Rio Cuiabá (AP1 and AP4) and two near the Rio São Lourenço (AP10 and AP11). In AP11, the horizons contrast in particle size between the profile basis and the surface. In AP1, AP4 and AP10, the horizons overlaying the sand layer have similar particle size properties, mainly in terms of sand distribution. In the first case, floods (surface water) seem to have originated the horizons and layers with contrasting texture. In the second case, avulsion is the most pronounced process. Therefore, the two modes can form soils with contrasting texture that are discriminable by soil morphology, based on the distinct features associated to the specific sedimentation processes.
Effect of brushwood transposition on the leaf litter arthropod fauna in a cerrado area
Authors: Vergílio Paula Cristina Benetton , Knoll Fátima do Rosário Naschenveng , Mariano Daniela da Silva , Dinardi Nágila Maiara , Ueda Marcos Yukio , Cavassan Osmar
Published: December 2013

The results of ecological restoration techniques can be monitored through biological indicators of soil quality such as the leaf litter arthropod fauna. This study aimed to determine the immediate effect of brushwood transposition transferred from an area of native vegetation to a disturbed area, on the leaf litter arthropod fauna in a degraded cerrado area. The arthropod fauna of four areas was compared: a degraded area with signal grass, two experimental brushwood transposition areas, with and without castor oil plants, and an area of native cerrado. In total, 7,660 individuals belonging to 23 taxa were sampled. Acari and Collembola were the most abundant taxa in all studied areas, followed by Coleoptera, Diptera, Hemiptera, Hymenoptera, and Symphyla. The brushwood transposition area without castor oil plants had the lowest abundance and dominance and the highest diversity of all areas, providing evidence of changes in the soil community. Conversely, the results showed that the presence of castor oil plants hampered early succession, negatively affecting ecological restoration in this area.
Análise da determinação da condutividade hidráulica do solo pelo método do perfil instantâneo
Authors: Gonçalves Adriano Dicesar Martins de Araújo , Libardi Paulo Leonel
Published: December 2013

A condutividade hidráulica do solo K é uma propriedade que expressa a facilidade com que a água nele se movimenta; é importante para o manejo do solo, para a produção das culturas e para a preservação do solo e do ambiente. A determinação da condutividade hidráulica pode ser feita por métodos de laboratório e de campo; o primeiro, com maior controle das condições experimentais e, o segundo, com menor grau de perturbação no solo. Dentre os métodos de campo, o mais utilizado é o do perfil instantâneo, tanto o original como o modificado, em que se obtém teoricamente uma relação entre o conteúdo de água θ e o tempo de redistribuição t, supondo gradiente de potencial total igual a um. No intuito de realizar uma análise mais profunda desse método, foi desenvolvido um estudo com o objetivo de verificar a possibilidade de se obter uma relação do conteúdo de água no solo, em função do tempo de redistribuição sem a suposição da existência de gradiente de potencial total unitário. O estudo foi desenvolvido com dados de quatro solos e a validação da relação proposta foi realizada por comparação da função K(θ) obtida a partir dela com a alcançada tradicionalmente. Com base na análise dos resultados, pode-se concluir que a relação proposta entre θ e t para o método do perfil instantâneo apresentou-se válida e que o gradiente de potencial total pode influir tanto o parâmetro γ como o parâmetro K0 da equação K = K0 exp [γ (θ-θ0)], ajustada aos dados experimentais. No caso específico dos solos avaliados neste trabalho, o gradiente de potencial teve baixa influência no parâmetro γ, comparada à sua influência no parâmetro K0, levando à possibilidade de uso de um gradiente de potencial total médio para obtenção da função K(θ). Além disso, observou-se que o procedimento para o cálculo da densidade de fluxo a partir da curva da armazenagem em função do tempo de redistribuição da água é muito mais simples do que o procedimento original utilizado no método do perfil instantâneo.
Accumulation of phosphorus fractions and contamination potential in vineyard soils in the southern region of the state of Santa Catarina, Brazil
Authors: Schmitt Djalma Eugênio , Comin Jucinei José , Ceretta Carlos Alberto , Gatiboni Luciano Colpo , Tiecher Tales , Lorensini Felipe , Heinzen Janaina , Ambrosini Vítor Gabriel , Moraes Marcel Pires de , Brunetto Gustavo
Published: December 2013

In vineyards, if phosphate is applied both before planting and at intervals during growth without consideration of technical criteria, the soil P fractions may be increased and their proportions altered. This study was carried out to evaluate the accumulation of P fractions and the parameters of the adsorption isotherm in a sandy Typic Hapludalf soil in vineyards with a history of successive and excessive phosphate fertilization. In December 2010, two vineyards were selected, one 4 and the other 15 years old, in Urussanga, State of Santa Catarina (Brazil). Three trenches were dug in each area and soil was collected from the 0-5, 5-10 and 10-20 cm depth ranges. The soil samples were dried in a forced-air oven, sieved and subjected to chemical analyses, P chemical fractionation and P adsorption isotherms. Excessive phosphate fertilization, before and during cultivation, particularly in the older vineyard and, consequently, with a longer history of phosphate fertilization, increased the inorganic P concentrations to the depth of 20 cm, especially in labile fractions extracted by anion exchange resin and NaHCO3 in the non-labile fraction, as well as in the non-labile fraction extracted by 1.0 mol L-1 HCl. The application of phosphate fertilizers and the long cultivation period increased the P levels in the organic labile fraction extracted by 0.5 mol L-1 NaHCO3, and especially in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH. Phosphate fertilization of older vineyards, i.e., cultivated for 15 years, increased the amounts of P desorbed in water, indicating a risk of contamination of surface waters and groundwater. The phosphate fertilization before planting, without considering the results of soil analysis, and during cultivation, disregarding the results of soil analysis, leaf analysis and expected yield, led to a reduction in the maximum P adsorption capacity in the 0-5 cm layer of vineyard 2, indicating saturation of part of the reactive particle adsorption sites.
Produtividade do milho em condições de diferentes manejos do solo e de doses de nitrogênio
Authors: Kappes Claudinei , Arf Orivaldo , Andrade João Antonio da Costa
Published: December 2013

Pesquisas têm sido desenvolvidas buscando identificar a melhor dose de N para o milho nos mais diferenciados sistemas de manejo do solo. Contudo, não há ainda concordância quanto aos resultados, pois a dinâmica desse nutriente é influenciada pelo manejo do solo e pelas coberturas vegetais. O objetivo deste trabalho foi avaliar a produção de matéria seca e acúmulo de nutrientes em coberturas vegetais e produtividade do milho em sucessão, submetidos a diferentes manejos do solo e de doses de N. Os experimentos foram conduzidos no município de Selvíria, MS, durante os anos agrícolas 2009/2010 e 2010/2011, sob Latossolo Vermelho distrófico típico argiloso. Foram estabelecidos 36 tratamentos com quatro repetições, em blocos casualizados, resultantes da combinação de coberturas vegetais (milheto, Crotalaria juncea e milheto + Crotalaria juncea), manejo do solo (preparo com escarificador + grade "leve", grade "pesada" + grade "leve" e sistema plantio direto) e doses de N em cobertura (0, 60, 90 e 120 kg ha-1 - ureia como fonte). O híbrido de milho utilizado foi o DKB 350 YG® e o N, aplicado no estádio V5 (quinta folha expandida). Ocorreu incremento linear do índice de clorofila foliar, teor de N foliar, comprimento e diâmetro de espiga, massa de 1.000 grãos e produtividade, com o aumento nas doses de N em cobertura. A utilização de crotalária e de milheto + crotalária como antecessoras, associada à aplicação de 120 kg ha-1 de N em cobertura, proporcionou maior produtividade do milho após dois anos agrícolas.
Effects of tillage systems on physical properties of a cohesive yellow argisol in the northern state of Espírito Santo, Brazil
Authors: Zuffo Valmir José , Pires Fabio Ribeiro , Bonomo Robson , Vitória Edney Leandro da , Celin Filho Ademar , Santos Eduardo Oliveira de Jesus
Published: December 2013

Tillage systems are a key element of the technology of crop production, both with a view to crop yield and from the perspective of soil conservation and sustainability of the production system. The aim of this paper was to evaluate the effects of five tillage systems on the physical properties of a cohesive Yellow Argisol. The experiment was installed in the field on January 21, 2011 and lasted 260 days, in an area previously used as pasture with Brachiaria grass without liming or fertilization, but irrigated by a low pressure spray system. The treatments, in five replications and in a randomized block design, consisted of: 1) disk plow (twice) + disk harrow + ridge-furrow tillage (raising a ridge along the planting row), 135 days after transplanting (DP + RID); 2) disk plow (twice) + disk harrow (DP no RID); 3) subsoiler (SB); 4) disk plow (twice) + disk harrow + scarification with three shanks along the plant row (DP + SPR); and 5) disk plow (twice) + disk harrow + scarification with three shanks in the total area (DP + STA). In all tillage systems, furrows were mechanically opened for the papaya plants. After the treatments, the mechanical resistance to penetration was determined, followed by soil moisture, mean weight diameter (MWD), geometric mean diameter (GMD), bulk density (BD), macroporosity (Ma), microporosity (Mi), and number of fruits per plant. There were differences in penetration resistance (PR) between treatments. The subsoiler was more effective to decrease RP to a distance of 0.35 m from the plants, perpendicular to the plant row. The scarifier resulted in a lower PR than DP or SB, even at the depth of 0.40 m, and it was more effective at greater distances perpendicular to the plant. All tillage systems induced a PR between 2.0 and 3.0 MPa at the depth with the highest concentration of papaya tree roots (0-0.25 m), improving the physical conditions to this depth. There was no statistical difference among the treatments for BD, Ma, Mi, MWD, and GMD at a depth of 0.20 m. The disk plow changed the physical properties of the soil most intensely to a depth of 0.20 m. The use of scarification, reduced tillage with a forest subsoiler, or ridge-furrow tillage did not improve the physical properties in the rhizosphere. Reduced tillage with a forest subsoiler resulted in a lower number of fruits per plant than all other treatments, which did not differ from each other.
O uso das TIC no ensino da morfologia nos cursos de saúde do Rio Grande do Norte
Authors: Lopes Roanny Torres , Pereira Andresa Costa , Silva Marco Antônio Dias da
Published: December 2013

A expansão do uso das Tecnologias de Informação e Comunicação (TIC) modificou as formas de obtenção de conhecimento. Acredita-se que a facilidade de acesso a conteúdo nem sempre confiável somada ao perfil dos novos estudantes pode demandar modificações no sistema de ensino. Assim, o objetivo deste estudo foi avaliar o perfil atual de utilização das TIC no estudo da Morfologia nos cursos da área de saúde de Instituições de Ensino Superior do Rio Grande do Norte. Foram realizadas buscas nos sites das instituições relacionadas na base de dados do Instituto Nacional de Estudos e Pesquisas Educacionais (Inep) para avaliar tanto a existência das páginas do curso e das disciplinas, quanto a forma de utilização das TIC. Constatou-se que, em abril de 2012, 69% dos cursos apresentavam página e em outubro do mesmo ano esse número caiu para 58%. Quanto às instituições, 50% das públicas possuem páginas para seus cursos contra 75% das IES privadas. Nenhuma das universidades apresentava página relacionada à disciplina de Morfologia vinculada ao site do curso. Conclui-se que as TIC ainda são subutilizadas pelos cursos de saúde no RN.
A atenção primária na formação médica: a experiência de uma turma de medicina
Authors: Souza Clarissa França Tavares de , Oliveira Diandra Lourena Lopes de , Monteiro Gabriella da Silva , Barboza Haiana Madeiro de Melo , Ricardo Gustavo Piech , Lacerda Neto Manuel Cavalcante de , Assis Tereza Angélica Lopes de , Moura Alexandre Costa
Published: December 2013

A partir da criação do Sistema Único de Saúde (SUS) e da implantação do Programa Saúde da Família (PSF), exige-se que os novos profissionais da saúde pública desenvolvam, desde os cursos de graduação, visão integral do paciente e olhar crítico para a realidade da comunidade e para sua própria atuação no PSF. Com esse objetivo, a Faculdade de Medicina da Universidade Federal de Alagoas (Famed-Ufal), em 2005, introduziu modificações curriculares que permitem aos estudantes uma vivência mais ampla no contexto da Atenção Primária à Saúde (APS). Este relato discorre, por meio da análise qualitativa de diários de campo, sobre as experiências de 22 acadêmicos de Medicina do segundo período durante as aulas práticas em uma comunidade coberta pelo PSF. Oitenta e seis por cento dos alunos observaram algum tipo de dificuldade enfrentada pela Unidade de Saúde; 95% destacaram a correspondência entre aulas práticas e o processo de aprendizagem; e 59% apontaram a importância da relação médico-paciente. Desta forma, o contato inicial do estudante de Medicina com os serviços de APS deve ser vivenciado de forma ativa e crítica, com estímulos para que investigue aspectos desconhecidos para ele até então.
Conversão de árvores em multiprodutos da madeira utilizando programação inteira
Authors: Campos Bráulio Pizziôlo Furtado , Binoti Daniel Henrique Breda , Silva Márcio Lopes da , Leite Hélio Garcia , Binoti Mayra Luiza Marques da Silva
Published: December 2013

Este estudo foi conduzido visando aumentar a renda e a segurança de um empreendimento florestal através da conversão de árvores em multiprodutos de madeira utilizando programação inteira. Os dados utilizados são referentes a um plantio de um clone híbrido de Eucalyptus grandis x Eucalyptus urophylla, aos 7 anos de um produtor rural na zona da mata em Minas Gerais. Para realização da conversão otimizada, foram utilizadas informações de alternativas de comercialiação da madeira produzida no povoamento e das características dos produtos. Foram consideradas 4 alternativas de destino das toras: energia, celulose, escora e serraria, com diferentes dimensões requeridas quanto aos diâmetros mínimos e máximos e o comprimento das toras. O problema se resumiu em atender a combinação otimizada baseado em dois cenários propostos: a) Maximização do volume total obtido, e b) otimização da receita global obtida. A fim comparativo, destinou-se a floresta a um único produto sem estudo de otimização. A comparação dos resultados obtidos demonstra os benefícios econômicos obtidos pela conversão do plantio em multiprodutos quando comparado a uso único, tendo um acréscimo médio de 33,69% na receita média obtida por apenas um produto. A maximização da receita total obtida teve um acréscimo de 20,6% e 16,3% quando comparada a receita obtida pela destinação do povoamento para escora e pela maximização do volume respectivamente. Logo, conclui-se que a otimização da receita global demonstrou-se ser a melhor alternativa de remuneração advinda do povoamento florestal.
Youth, gender and sexual practices in Brazil
Authors: Heilborn Maria Luiza , Cabral Cristiane da Silva
Published: December 2013

Based on a survey developed in three Brazilian state capitals, this paper presents data and interpretations about the sexual practices and management of sexual desire among male and female youth. The findings indicate a close connection between gender and sexuality in modeling individuals' sexual trajectories and subjectivities. There is a higher acceptance of practices formerly considered to be deviant, revealing that sexual morality among youth has acquired a more modern configuration. This paper argues that there is a differentiated modernization of sexual values: gender disparities were detected in the answers of respondents in all social environments. The increasing flexibility of individual trajectories does not necessarily lead to gender equality. The affirmation that the individualizing process coexists with the persistence of traditional gender ideology entails the recognition that men and women's, and different generations' and social segments' modernization paths do not evolve in the same way.
Sex trade among men: negotiating sex, bodies and identity categories
Authors: Moscheta Murilo dos Santos , McNamee Sheila , Santos Manoel Antônio dos
Published: December 2013

Commercial sex is a marginalized and highly stigmatized activity in Brazilian culture. In this article we aim at investigating the discursive strategies used by young men who trade sex in order to resist stigmatization and social exclusion. We interviewed 24 young men who trade sex in a medium sized city in Brazil. Discursive strategies used by the interviewees to avoid social stigma could be summarized as (1) a reduction of sexual activity to its commercial sense by employing a conceptualization of masculinity that focuses on moral values and disregards sexual intercourse, (2) an emphasis on the anatomic characteristics as a criterion to delimit sexual identification categories, and (3) a shifting of sexual systems from one based on sexual object choice to one based on sexual aim. The discussion highlights that the interviewees were actively negotiating with normative assumptions of sexuality and thus producing either its subversion or conservation.
Post-structuralism and psychological research on/through the internet
Authors: Arcoverde Renata Lopes , Amazonas Maria Cristina Lopes de Almeida
Published: December 2013

The present study has as aim to describe some procedures used for research in or through social networks, especially in Psychology. In order to do so, different ways of using the Internet as a tool or an object of investigation were analyzed, considering ethical and technical parameters in resolution 196 of the National Health Council, and in the Psychologist Code of Professional Ethics. Finally, there is a discussion on the adequacy of such procedures with post-structuralism theory, based on classic authors of this philosophical and theoretical perspective, such as Michel Foucault, Judith Butler and Tomaz Tadeu da Silva.
Drug policy: what impact does it have on children and youth?
Authors: Passos Izabel Friche , Lima Isabella Cristina Barral Faria
Published: December 2013

This article reviews the national and international literature on drug policy, focusing on harm reduction strategies and their impact on the development of children and youth in Brazil. Without using statistical criteria, this paper develops an overview of the current context and discusses the trends in the literature through an exploratory analysis of production and a non-exhaustive bibliography. The results showed that state investment in public policies for the treatment and prevention of drug abuse is recent. In addition, harm reduction is still a little known and controversial strategy, especially among children and adolescents.
Adaptação de um wiki para a informatização da documentação do sistema de gestão da qualidade
Authors: Costal Graziele Cristina Silveira Zerbini , Turrioni João Batista , Martins Roberto Antonio
Published: December 2013

A documentação de um Sistema de Gestão da Qualidade padrão ISO 9001 é muitas vezes vista como uma fonte de burocracia nas organizações. Este artigo descreve o WikiQMS como uma alternativa para a informatização da documentação de tal sistema. O método científico foi aplicado para o desenvolvimento do sistema. O protótipo foi desenvolvido a partir de um software wiki, com base nos requisitos da ISO 9001 levantados na literatura e também pela avaliação de um painel de especialistas. O experimento de campo em uma empresa júnior permitiu validar o sistema em uma situação real de implantação da documentação do Sistema de Gestão da Qualidade. O protótipo atende adequadamente aos requisitos mínimos de implantação e gestão da documentação do Sistema de Gestão da Qualidade padrão ISO 9001. Além disso, o WikiQMS apresenta as vantagens de uma solução da Web 2.0 para a questão da edição colaborativa, autoria coletiva, acessibilidade e usabilidade.
A afeição dos cidadãos pelos políticos mal-afamados: identificando os perfis associados à aceitação do 'rouba, mas faz' no Brasil
Authors: Bonifácio Robert
Published: December 2013

O artigo investiga os perfis de cidadãos associados favoravelmente à ideia do "rouba, mas faz", que significa concordância com a conduta de políticos que incorrem em atos de corrupção, mas que realizam um governo entendido como satisfatório. Utiliza-se como material empírico dois surveys de abrangência nacional, realizados em 2002 e 2006, e os principais resultados obtidos com as análises dos dados apontam para o forte rechaçamento da ideia de "rouba, mas faz" e para a importância explicativa de variáveis que indicam avaliação e desconfiança institucional.