bluuebunny/crossref_metadata_2025 huggingface dataset:
Arc Behavior and Droplet Transfer Process of VP CMT
Authors: Hu Yun Yan , Mu Sen , Wang Jun
Published: December 2013

Cold metal transfer (CMT) is widely used in thin sheets welding, owing to its low heat input and freedom of spatter. An evolutionary technology, called CMT Adv, combines CMT and variable polarity (VP) process. Arc behavior analysis and droplet transfer analysis were performed by image capture system synchronized with current and voltage sensor. Checker calibration method was used to get dimensions of droplets. The results show that motion of filler wire, current and voltage waveform and droplet transfer of VP CMT (CMT Adv) are coordinated to maintain welding stability. And through precise energy control, droplets of same dimensions can be got in EP and EN period, which are similar to diameter of filler wire. To from droplets with same dimensions, lower power was supplied and melt efficiency is higher in EN period.
Nonlinear Evolution of the Travelling Waves in Roll Coating Flows of Thin Viscoelastic Polymer Falling Films
Authors: Cheng Po Jen , Liu Kuo Chi , Wang Cheng Chi
Published: December 2013

Roll coating is widely used to apply a thin liquid film to a continuous, flexible substrate. It is known that macroscopic instabilities of the film system can result in a non-homogenous film growth to fluid flow. The influence of the Rossby number, the viscoelastic parameter, and the roller radius on the nonlinear hydrodynamic stability of a thin viscoelastic polymer fluid film coating flow down a rotating vertical roller is investigated. In contrast to most previous studies, the solution scheme employed in this study is based on a numerical approximation approach rather than an analytical method. The size of the explosive supercritical instability region increases significantly as the roller rotates. It is shown that the stability of the liquid film is enhanced by reducing the viscoelastic effect or decreasing the speed of the rotating roller. At higher values of the Reynolds number, the tendency of the rotation effect to prompt thin-film instability increases with an increasing roller radius.
Material Properties of Windows in the Building Energy Concept
Authors: Palková Adela , Palko Milan
Published: December 2013

The window is an exposed part of the external cladding. Assessment of windows regarding the heat transfer coefficient. Categorization of thermo-technical requirements for windows. Experimental measurement and determination of heat transfer coefficient. Calculation and determination of linear thermal transmittance. Material base of windows for passive energy building standard.
The Measurement of Pressures on the Cube Model in VZLU in Prague and BLWT Bratislava
Authors: Lobotka Peter , Magát Marek , Žilinský Juraj
Published: December 2013

This paper deals with experimental measurement of pressures on the cube made in the wind tunnel of Aerospace Research and Test Establishment (VZLU) in Prague Letnany and calibrating the wind tunnel of Faculty of Civil Engineering in the Slovak University of Technology in Bratislava. The basis for the construction of the cube model in 1:30 scale was the cube in-situ with dimensions of 6 m in Great Britain in town called Silsoe. It describes the scope and application in practice.
Simulation of Natural Ventilation Taking into Account the CO2 Concentration and Room Temperature
Authors: Čeheľová Dagmara , Janák Milan , Bielek Boris
Published: December 2013

The operating mode of the building, its occupancy and user behaviour has a significant impact on the CO2 concentration and on the internal temperature of the room and therefore on the quality of the indoor environment and on the overall energy performance of the building. This paper summarises results from dynamic thermal modelling software combined with an air flow model for the assessment of a natural ventilation potential in office premises of the building not only with regards to the internal temperature, but also to the CO2 concentration.
Glass as a Fire Construction
Authors: Mikolai Imrich
Published: December 2013

Mass using of transparent building constructions as a fire construction has been marked in Slovakia of late. The transparent building constructions are most especially using for a inter fire compartments and also as a non-loadbearing facades. Important phase of transparent building constructions developing was possibility to design them thanks to varied offering of production the systems.
Types of Doors and its Impact on Airborne Sound Insulation
Authors: Dlhý Dušan
Published: December 2013

Acoustically speaking, a door as a part of a wall cladding or internal wall partition is usually the weakest element of such a structure [1,2]. The less effective sound insulation properties of a door, in comparison with the main wall structure, results in the fact that the sound reduction index of the door is one of the most important factors affecting the total sound isolation properties of a complex wall.
The Effect of Free Joints on Sound Insulation of Constructions
Authors: Dlhý Dušan
Published: December 2013

Noise protection of a building ́s interior is one of the fundamental functions of building constructions. These constructions can be understood as internal partitions, ceilings or external wall-/roof claddings. However, walls often consist of basic building materials and openings; such windows and doors as well as the acoustical properties of such structures are determined by both parts (e.g., a windows and the wall structure). The acoustical quality of opening is in general affected not only by the particular structure, but also by the concept of the mounting. Acoustical requirements should be applied in all its parts, such as the construction of the window (door) frame, window (door) wing and the realization of the functional gap as well as by application of a sealant.
On the base of experimental measurements in Acoustics Chambers of the Faculty of Civil Engineering of Slovak Technical University and mathematical analysis we have determined index of sound insulation of free joint.
The Influence of the Shape Space on the Scattering of the Sound Energy
Authors: Pernišová Alena , Dlhý Dušan
Published: December 2013

The sound level adjacent to the sound sources is mainly characterized by the straight sound. The dispersion sound ratio is increasing with distance increasing and within the limited range round the sound source, the sound level is higher, in the area with dispersion bodies even higher than in an empty area. The laws of sound propagation in empty areas are derived on classical geometric base. The laws of sound propagation in large areas with dispersion objects are also derived from these laws complemented with the Kuttruff ́s equation of reverberation process in media with dispersion bodies. Simultaneously the sound energy is according to the purpose divided into the straight sound and the reverberation. The straight sound is the energetic ratio of sound, that is during the way to destination not dispersed and the propagation laws are equal to empty areas propagation laws are equal to empty areas propagation laws. The dispersed sound is the ratio of sound energy that reaches the destination after one or more reflections. The energy result is then the sum of densities of dispersion and straight sound.
Common Characteristics of Zero Energy Buildings in Relation to the Energy Distribution Networks
Authors: Bielek Boris , Bielek Milan
Published: December 2013

Physical quantification of the building envelope. Energy quantification of the building. Energy from fossil sources. Energy from ecologically clean renewable sources. Nearly net zero energy buildings. Net zero energy buildings. Net plus energy buildings. The characteristics of zero energy buildings in relation to the energy distribution networks. Requirements for physical quantification of buildings with a zero energy balance in relation to energy distribution networks.
The Results of Experimental Chamber Temperature Measurements for a Light-Weight Wooden Envelope
Authors: Labovský Martin , Lopušniak Martin , Šimiček Jozef
Published: December 2013

Considering the ambitions of passive buildings to achieve net zero values with regard to environmental impacts, it is likely that the trend in the construction of wooden houses will increase. A climate chamber was built with a representative light-weight wooden envelope in Košice to answer the question of how wooden cladding would behave in real-world conditions. The paper describes the progress of temperatures in the light-weight wooden structure situated in the peripheral wall of the experimental chamber. The data obtained will serve as a basis for verification of simulation models and their optimization in the design of the envelope. The aim is to verify the accuracy of measurement data and the expected behaviour of the wooden construction envelope in terms of internal and surface temperatures of the construction.
Long Time Testing of Temperature Parameters of Wooden Lightweight External Walls
Authors: Ďurica Pavol , Štúňová Marianna , Ponechal Radoslav , Cangár Marek
Published: December 2013

The article will present the partial knowledge of the area of thermal properties of the wooden lightweight external walls. The temperatures on the monitored samples of walls built in the air-conditioned room in the Laboratory of pavilion type for one week in cool, intermediate and warm periods will be shown. It will be described as the wall develops under the stationary conditions of the internal environment and the real conditions outside changed during the selected time period. Further differences in surface temperatures affected tone color design plaster used on the exterior facades will be followed. The thermal parameters of variant wall constructions, obtained under the steady state and non-steady thermal state and simulations will be compared.
Renewal of Envelope Constructions of Panel Residential Houses as a Tool for Elimination of Hygienic Problems of Thermal Bridges
Authors: Menďan Rastislav , Vavrovič Boris
Published: December 2013

In a general sense, it is possible to say, that panel houses show considerable defects. Many of them results from insufficient thermal protection. At present, these buildings fail to meet the requirements from the point of view of neither thermal insulation properties nor hygienic criterion (Slovak Standard STN 73 0540-2:2012). This shortcoming manifests itself not only in large consumption of heat for space heating, but also in functional and hygienic shortcomings of envelope constructions (formation of moulds). The paper deals with a thermal technical analysis of selected critical details (thermal bridges) of envelope constructions of panel residential houses in original state and in state after adding thermal insulation.
Physical Assessment of a Window Using a Computer Simulation
Authors: Palko Milan
Published: December 2013

The simulation program ANSYS and its use in the simulation of a window. Code implementation of Fluent and CFX programs. ANSYS program structure in CFX module. Computer simulation of aluminum windows - simple heat conduction. Computer simulation of wooden windows - the transfer of heat through conduction and convection. Simulation method "Fluid - Solid Interaction (FSI).
Importance of Envelope Construction Renewal in Panel Apartment Buildings in Terms of Basic Thermal Properties
Authors: Vavrovič Boris
Published: December 2013

Envelope constructions of panel apartment buildings in Slovakia are made up of one or more layers of external panels. They typically have one or double-skin flat roofs. Nowadays, almost all envelope constructions, that yet have not been insulated and renovated, show to have insufficient thermoisolation performances. Especially roofs seems to have unsatisfactory moisture regime facilities. The article describes fundamental thermal technical characteristics of envelope constructions (external walls and flat roofs) in panel appartment buildings in their original state and after renewal in the form of additional thermal insulation.
Analysis and Quantification of Grain Size of Various DHP Copper Tubes Manufacturing Processes
Authors: Bagherian Ehsaan Reza , Bell Colin , Cooper Mervyn , Fan Yong Chang , Frame Brian , Rose Mervyn
Published: December 2013

Deoxidized High Phosphorus (DHP) Copper tubes are frequently used in numerous industrial and household applications. To ensure the acceptability of DHP copper tubes prepared by various industrial processes, the quality of the DHP copper tubes must be evaluated and one of the best ways to do so is to examine the microstructure and metallography and quantify grain size. In this paper the authors considered the average grain size of copper tube samples made traditionally as well as by the planetary rolling and CastTube process. Because of the small thickness of the CastTube samples, in certain circumstances traditional methods of grain counting were not plausible and a new procedure for grain counting needed developed. This paper is about the development and evaluation of grain sizes in continuously cast tube samples using both the planimetric procedure (ASTM E112) and a new method, which will be herby, referred to as the total grain counting method. This paper also concludes that there is a large difference in the grain size of tubes with different manufacturing methods.
Study on the Dense-Packing Effect and Properties of Multi-Component Cementitious Material
Authors: Yang Wen , Feng Nai Qian , Hui Tew Kia , Jia Li Li , Cheng Bao Jun
Published: December 2013

The paper studied the effects of single addition of ultrafine fly ash (UFA) and mixed addition of silica fumeultrafine fly ash (SF-UFA) on powder pressure entity dense packing density, mechanical performance and microstructure structure of composite cement paste. The results show that, the ternary system of mixed addition of SF-UFA can effectively further reduced the compacting voidage and more increased packing density of composite powder, compared with the binary system of single addition of UFA. And when the content of SF is 8%, the compacting voidage is the lowest. Next, in the ternary system of mixed with silica fume, ultrafine fly ash and cement (SF-UFA-C), with the increase of silica fume (SF), the total porosity and pore diameter of hardened cementing paste decreased further compared with binary system, and with 8% content of SF and 17% content of UFA, the total porosity of hardened cement paste is the lowest, decreased by 60% than that of reference sample. At last, mixed addition of SF-UFA can improve the long-term strength of composite cement paste either, the compressive strength of 60 days hydration increased by nearly 9% compared with UFA-C and increased 41% compared with the reference sample.
Low Band Gap Co80Ni20@RGO Nanocomposite
Authors: De Debajyoti , Majumdar Subham , Giri Saurav
Published: December 2013

We report a novel approach of designing ordered arrangement of disorder on the extended structures of graphene. We prepared single phase nanoparticles of Co80Ni20 alloy embedded in Reduced Graphene Oxide (RGO). Co80Ni20 shows a large moment and a soft ferromagnetic character like permalloy at room temperature. Temperature dependence of permittivity shows a behavior quite contrary to usual ceramic materials showing an increase with decreasing temperature, exhibiting a maximum. A very large magnitude of permittivity ~ 5000 is observed, which is possibly related to an interesting Maxwell-Wagner type effect arising from the charge localization in the graphene sheets. For a deeper insight of the mechanism, correlations with other phenomena are studied through magnetization, dc resistivity, I-V etc. investigations. Temperature dependent magnetization indicates toward strong ferromagnetic interaction and MH loop shows low coercivity ferromagnetic interaction at 4 K and even at room temperature.
The Effect of Mixing Coal with Biomass in Solid Fuel Briquettes
Authors: Sing Chin Yee , Aris Mohd Shiraz
Published: December 2013

Burning fossil fuel like coal in power plants released carbon dioxide that had been absorbed millions of years ago. Unfortunately, excessive carbon dioxide emission had led to global warming. Malaysia, as one of the major exporters of palm oil, has abundant oil palm mill residues that could be converted into value-added product like biomass fuel briquettes. Fuel briquette with palm kernel shell and palm mesocarp fibre as its main ingredients showed satisfactory fuel characteristics and mechanical properties as a pure biomass fuel briquette. The effects of adding some coal of higher calorific value to the satisfactory biomass fuel briquette were focused in this study. Various coal-biomass fuel blends were used, ranging from 0wt% coal to 50wt% coal. The fuel properties and mechanical properties of pure biomass briquette and briquettes with different amount of coal added were compared experimentally. From the fuel properties tests, it was found that as the coal content in the briquette was increased, the carbon content and calorific value increased. Mechanical property tests on the fuel briquettes showed a mixture of results, with some favored higher portion of coal in the briquette for better handling, transport and storage properties while some favored greater amount of biomass.
Experimental Investigation on Nanofluids Effectiveness on Heat Transfer in Oscillating Heat Pipe
Authors: Goshayeshi Hamid R. , Khosravi Ali , Karizaki Mehdi Abedpour
Published: December 2013

An experimental investigation of the oscillatory flow and heat transfer in a vertical oscillating heat pipe (OHP) was conducted. The oscillating heat pipe was made of a copper-glass tube. Flow inside the oscillating heat pipe at different heat loads was recorded by a high speed camera. Through this research, the authors investigated the effect of utilizing nanofluids on heat transfer amount in heat pipes. The employed nanofluids in this study were water-Fe2O3, water-SiO2 and water-TiO2 with various volumetric concentrations. The results show that after adding nanoparticles in the base fluid (here water) heat transfer rate increases significantly. It's also noteworthy, of the all applied nanofluids, water-TiO2 mixture presents the best enhancement in heat transfer amount.
Numerical Charaterization of the Shear Behavior of Hetero-Junction Carbon Nanotubes
Authors: Yengejeh Sadegh Imani , Akbarzade Mojtaba , Öchsner Andreas
Published: December 2013

In this study, numerous types of straight hetero-junction carbon nanotubes (CNTs) and their fundamental CNTs were investigated by the finite element method (FEM). By applying the FEM, the shear behavior of these hetero-junctions was obtained thorough numerical simulation. The behavior of hetero-junctions and their constituent CNTs were investigated. The investigations revealed that the twisting angle of straight hetero-junction CNTs lies within the range of twisting angle of their fundamental CNTs. In addition, change of boundary conditions did not significantly change the value of obtained twisting angle of hetero-junctions. It was also concluded that the shear behavior of straight hetero-junctions and their constituent CNTs increases by increasing the chiral number of both armchair and zigzag CNTs. The current study provides a better insight towards the prediction of straight hetero-junction CNTs behavior.
Denke as krisisterrein in die verskynsel van kerkkrimping by tradisioneel Afrikaanssprekende susterkerke
Authors: Van Helden Phia
Published: December 2013

Thinking as a crisis area in the phenomenon of the declining traditionally Afrikaans �sister churches�. Since little can be done, humanly speaking, to address the numerous factors influencing the decline of churches, it is obvious that everything humanly possible must be done. Thinking plays a major role in ecclesiology. This article focuses on human thinking as crisis area and as variable in ecclesiology. Because thinking is the determining factor controlling human activities, it is necessary to transform and change thinking when imbalances appear under the microscope of the last command of Jesus. Through the Great Commission, the Christocentric paradigm is revealed which serves as a corrective guideline for the imbalances created by the institutionalistic (I-paradigm) or the spiritualistic (S-paradigm) paradigms. Appreciative Inquiry (AI) is rediscovered as Scripture-based approach regarding change in thinking and the resulting change in the ecclesiastic crisis area, thus focussing on a more complete obedience to the Great Commission and promoting the possibility of natural church growth.
Increased Lysosomal Membrane Permeabilization in Oxidant-exposed Macrophages of Human Fibrotic Lungs
Authors: Persson Hans L , Vainikka Linda K.
Published: December 2013

A disrupted balance of reduced glutathione (GSH) and iron (Fe) and subsequent enhanced susceptibility of lysosomes of lung macrophages (LMs) to oxidants may play a role in lung fibrogenesis. We assessed cellular Fe/GSH, lysosomal membrane permeabilization (LMP), and cell death in cultures of oxidant exposed LMs. LMs from 7 lung fibrosis patients and healthy subjects were exposed to a physiologic concentration of H2O2for 1 h. LMP was assessed with acridine orange green fluorescence, apoptosis/necrosis were estimated by apoptotic DNA and typical morphology, Fe was assessed with Prussian blue staining/atomic absorption spectrophotometry, and GSH was evaluated using a GSH assay kit. Oxidant-induced LMP and cell death were more pronounced in cultures of LMs from patients with lung fibrosis, and these cells contained less GSH and more cytochemically stained Fe. These observations indicate that LMP may be involved in fibrosis development, possibly through activation of the inflammasome complex. Further studies are warranted for a detailed understanding.
Motionless of snail Hydrobia ulvae (Pennant) as response to sediment toxicity and its consequences for the post-exposure feeding
Authors: Araujo Cristiano VM , Blasco Julián , Moreno-Garrido Ignacio
Published: December 2013

Post-exposure feeding and motionless may be useful endpoints for assessing toxicity. The present study aimed to examine (i) the immobility of the estuarine snail Hydrobia ulvae resulting from short-term exposure to copper-spiked sediment, and subsequently, (ii) the potential application of post-exposure feeding (indirectly measured as pellets excreted) as an ecotoxicological response associated with motionlessness. Mobility and post-exposure feeding were influenced by copper contamination. Motionless was noticeable above the concentration of 200 Î¼g Cu g-1, where 40% of the organisms were inactive. Practically all the organisms remained active at the two lowest concentrations: 40 (control) and 60 Î¼g Cu g-1. For 400 and 800 Î¼g Cu g-1 the motionless was generally higher than 50%. Mortality higher than 25% was observed at 200, 400 and 800 Î¼g Cu g-1, with values of 27, 40 and 60%, respectively. The feeding inhibition values showed an increasing inhibition from 20% at the lowest concentration (60 Î¼g Cu g-1), up to 59% at 400 Î¼g Cu g-1; at concentration of 800 Î¼g Cu g-1, although the physical activity inhibition had reached 67%, the post-exposure feeding was 1.5 higher in relation to the control. Probably, the starvation period due to motionless during exposure seems to increase the post-exposure feeding and egestion when food was provided; alternatively, increased pellet production could also indicate a detoxification process.
Comparison of N. Atlantic heat storage estimates during the Argo period (1999–2010)
Authors: Wells N. C. , Couldrey M. , Ivchenko V. O.
Published: December 2013

Abstract. Ocean heat storage is an essential component of the climate system and there is considerable interest in its accurate evaluation. There are a number of heat storage products produced by many different groups. These products are derived from Argo as well as other platforms, for example XBT and CTD, in the last decade. Here we compare two heat storage estimates for the North Atlantic 0–2000 m from 10° to 70° N. One derived solely from Argo data whilst the other is derived from Argo and other platforms. It is found that there is a positive trend in heat storage over the period 1999–2010. This trend is influenced by a strong air–sea interaction event in 2009–2010, and this reduces the upward trend 1999–2008 identified previously. Both data sets are consistent with each other for the layer 0–1000 m on a timescale of beyond 1 yr. There are significant differences at sub-annual time scales and in the layer 1000–2000 m.
Owning the city: New media and citizen engagement in urban design
Authors: De Lange Michiel , De Waal Martijn
Published: December 2013

Over the last few years, the term ‘smart cities’ has gained traction in academic, industry, and policy debates about the deployment of new media technologies in urban settings. It is mostly used to describe and market technologies that make city infrastructures more efficient, and personalize the experience of the city. Here, we want to propose the notion of ‘ownership’ as a lens to take an alternative look at the role of urban new media in the city. With the notion of ownership we seek to investigate how digital media and culture allow citizens to engage with, organize around and act upon collective issues and engage in co–creating the social fabric and built form of the city. Taking ownership as the point of departure, we wish to broaden the debate about the role of new media technologies in urban design from an infrastructural to a social point of view, or from ‘city management’ to ‘city making.’
Pixels, bits and urban space: Observing the intersection of the space of information with urban space in augmented reality smartphone applications and peripheral vision displays
Authors: Drakopoulou Sophia
Published: December 2013

Today the urban environment can be seen as a mix of technically mediated elements and actual physical locations — the city is techno–synthetically composed. The method of observing the production of space, as asserted by Lefebvre, must take into account physical and non–physical spaces, produced out of the coexistence of everyday life and activities with the space of information. This paper explores the merging of bits and bytes with the urban environment and uses augmented reality applications for the smartphone and peripheral vision displays as case studies to illustrate how the method of visually layering digital graphics on to the image of actual space produces a new kind of spatial commodification.
Lifestyle transitions and the developing world: Reflections on the implications for health, well-being and wealth
Authors: Ejughemre Ufuoma John
Published: December 2013

Context: The past few decades witnessed significant economic growth in many developing countries of the world. These economic changes towards increasing gross domestic product (GDP) brought with it several other transitions in these countries: demographic, epidemiological, technological, and nutritional. These resulted in improving the living standards as well as life expectancy in many of these countries. However, of public health concern is the fact that these transitions paradoxically have their negative consequences on the health, well-being and wealth of the populace in these countries. Objectives: This review therefore assesses the evidence of the extent to which these changes have affected the living patterns in many developing countries and the epidemiological implications besides others issues on the populace in these countries. Methods: By using key words, the author involved a broad search of literatures on lifestyle changes, economic growth, nutrition, urbanization, smoking and alcohol, communicable and non-communicable diseases in countries termed low and middle income. Findings and conclusion: The review identified discernible evidence base about the implications of these changes on health, well-being and wealth of these nations. Accordingly, as lifestyle transitions now come to bear, it thus necessitates an all inclusive approach that will include proactive and pre-emptive interventions as well as consistent participation from governments, multilateral institutions, research-funding agencies, donors, and other players in health systems. This is because it will provide the global community with great opportunities in uniting high, middle, and low-income countries in a common purpose, given the shared interests of globalization and economic burdens worldwide.
Apresentação
Authors: Editores Os
Published: December 2013

A Revista do Instituto Geológico, inicia em 1980 uma neva ·edição. De 1943 a 1968, o antigo Instituto Geográfico e Geológico, que pelo Decreto n.o 6.822 de 26-09-75 passou a denominar-se Instituto Geológico, editou periodicamente a Revista "IGG", cessando sua publicação com o volume 20, em 1968. O Instituto Geológico, pretende editar dois números por ano de sua Revista, divulgando artigos escritos pelos pesquisadores da Instituição e outros, dentro da área de geociências. As opiniões ou conceitos expedidos nos artigos são de inteira responsabilidade de seus autores. Comissão Editorial
Variações do nível, marinho: alterações eustáticas no Quaternário
Authors: Vieira Percy Corrêa
Published: December 2013

As variações do nível médio dos oceanos são resultantes de fenômenos gerais (alteração eustática) e locais (alteração eustática). Durante o Período Quaternário houve várias subidas e descidas eustáticas do nível oceânico ligadas a fases interglaciais e glaciais. Por volta dos dezeito mil anos atrás o mar esteve em fase de descida máxima, com seu nível médio na isóbata atual aproximida de cento e dez metros; nesse tempo iniciou-se uma fase transgressiva (Trasgressão Flandriana), a qual teve seu máximo por volta do seis mil anos atrás. Daí para cá o nível médio do mar tem sofrido pequenas variações eustátiças, com tendência geral para abaixamento. Os dados obtidos para o Brasil confirmam as variações eustáticas constatadas nas outras partes do mundo.
Histórico abreviado do Instituto Geológico, de suas publicações e mapas
Authors: Peris Haydée Polito
Published: December 2013

Este trabalho é um breve resumo sobre o histórico da Instituição, baseado em artigos e folhetos acerca do assunto, escritos por grandes nomes que passaram pelo antigo Instituto Geográfico e Geológico. Também apresenta, um estudo das fases de editoração das publicações e mapas do Instituto, ao longo de sua vida.
Concurrent Generation of Functional Smooth Muscle and Endothelial Cells via a Vascular Progenitor
Authors: Marchand Melanie , Anderson Erica K. , Phadnis Smruti M. , Longaker Michael T. , Cooke John P. , Chen Bertha , Reijo Pera Renee A.
Published: December 2013

Smooth muscle cells (SMCs) and endothelial cells (ECs) are typically derived separately, with low efficiencies, from human pluripotent stem cells (hPSCs). The concurrent generation of these cell types might lead to potential applications in regenerative medicine to model, elucidate, and eventually treat vascular diseases. Here we report a robust two-step protocol that can be used to simultaneously generate large numbers of functional SMCs and ECs from a common proliferative vascular progenitor population via a two-dimensional culture system. We show here that coculturing hPSCs with OP9 cells in media supplemented with vascular endothelial growth factor, basic fibroblast growth factor, and bone morphogenetic protein 4 yields a higher percentage of CD31+CD34+ cells on day 8 of differentiation. Upon exposure to endothelial differentiation media and SM differentiation media, these vascular progenitors were able to differentiate and mature into functional endothelial cells and smooth muscle cells, respectively. Furthermore, we were able to expand the intermediate population more than a billionfold to generate sufficient numbers of ECs and SMCs in parallel for potential therapeutic transplantations.
In situ stress control on microcrack generation and macroscopic extensional fracture in exhuming bedrock
Authors: Leith Kerry , Moore Jeffrey R. , Amann Florian , Loew Simon
Published: December 2013

Crustal stresses beneath evolving alpine landscapes result from a combination of tectonic strain, bedrock exhumation, and topography. The stress field is regulated by elastic material properties and the brittle strength of critically stressed elements, particularly those within preexisting faults and intact rock. Combining Byerlee's law for crustal stresses with a recently developed trilinear fracture envelope, we propose an extension of the critically stressed crust concept to constrain in situ stresses through microcrack generation and extensional fracture propagation. A compilation of 814 global in situ stress measurements suggests microcrack development will limit long‐term rock strength, and maximum differential stresses in the upper ~1 km of the crust can be controlled by cohesive bedrock behavior. Using an elastoplastic, 2‐D finite‐difference model, we approximate in situ stress development within landscapes undergoing high rates of exhumation in both normal and reverse tectonic regimes. Critical near‐surface stresses in these environments are defined by the microcrack initiation threshold, estimated to be roughly one third of the unconfined compressive strength of intact rock, while stresses deeper in the crust adhere to Byerlee's law. Our models indicate that exhumation‐induced stresses limited by long‐term rock strength are the primary contributor to the near‐surface stress field, while topographic relief reduces stress near valley axes. Simulating glacial erosion then allows us to illustrate a path‐dependent relationship between critical stress development, fracture formation, and geomorphic processes. We find that glacial unloading can generate new microcracks in near‐surface bedrock, resulting in unstable macroscopic extensional (or “exfoliation”) fracture propagation during incision of U‐shaped alpine valleys.
Multiecho scheme advances surface NMR for aquifer characterization
Authors: Grunewald Elliot , Walsh David
Published: December 2013

Surface nuclear magnetic resonance (NMR) is increasingly used as a method to noninvasively characterize aquifers. This technology follows a successful history of NMR logging, applied over decades to estimate hydrocarbon reservoir properties. In contrast to logging, however, surface methods have utilized relatively simple acquisition sequences, from which pore‐scale properties may not be reliably and efficiently estimated. We demonstrate for the first time the capability of sophisticated multiecho measurements to rapidly record a surface NMR response that more directly reflects aquifer characteristics. Specifically, we develop an adaptation of the multipulse Carr‐Purcell‐Meiboom‐Gill (CPMG) sequence, widely used in logging, to measure the T2 relaxation response in a single scan. We validate this approach in a field surface NMR data set and by direct comparison with an NMR log. Adoption of the CPMG marked a landmark advancement in the history of logging NMR; we have now realized this same advancement in the surface NMR method.
Asthenospheric Pacific‐Atlantic flow barriers and the West Scotia Ridge extinction
Authors: Martos Yasmina M. , Galindo‐Zaldívar Jesús , Catalán Manuel , Bohoyo Fernando , Maldonado Andrés
Published: December 2013

The Drake Passage is considered a gateway for oceanic and asthenospheric flows since its opening, entailing widespread consequences for climate and plate tectonics, respectively. Both the surface and the 50 km upward continued Bouguer anomaly maps of the Scotia Sea and surrounding areas, based on Gravity Recovery and Climate Experiment gravity satellite data, improve our knowledge of deep lithospheric structures and the asthenosphere. We show that the West Scotia Sea is likely to be underlain by an anomalously low‐density upper mantle. Gravity data are compatible with variable lithospheric thicknesses related to asthenospheric currents. The new data suggest that the development of the Shackleton Fracture Zone since the middle Miocene was probably a main factor that determined the evolution of the eastward Pacific mantle flows and the extinction of the West Scotia Sea oceanic spreading around 6 Ma ago. Deep lithospheric roots are likely to divert asthenospheric currents around them, flowing eastward through Drake Passage.
An analysis of heliospheric magnetic field flux based on sunspot number from 1749 to today and prediction for the coming solar minimum
Authors: Goelzer Molly L. , Smith Charles W. , Schwadron Nathan A. , McCracken K. G.
Published: December 2013

It is now well established that many bulk properties of the solar wind rise and fall with the solar cycle, and the heliospheric magnetic field (HMF) intensity is no exception. The HMF intensity is seen to be maximum around the time of solar maximum, lowest during solar minimum, and lower still during the recent protracted solar minimum 2006–2009. One explanation of this behavior can be found in the theory of Schwadron et al. (2010) that argues magnetic flux is injected into interplanetary space by coronal mass ejection eruptions and removed by reconnection in the low solar atmosphere. This produces an HMF intensity that is correlated with sunspot number, and the rapid injection of flux followed by the slow removal by reconnection results in a hysteresis effect that is readily evident in the observations. Here for the first time we apply this theory to the sunspot record going back to 1749 and compare favorably our predictions to the results derived from10Be observations. We also make a prediction for the coming solar minimum based on results from the Dalton Minimum.
Deep seismic reflection images of the Wharton Basin oceanic crust and uppermost mantle offshore Northern Sumatra: Relation with active and past deformation
Authors: Carton Hélène , Singh Satish C. , Hananto Nugroho D. , Martin James , Djajadihardja Yusuf S. , Udrekh  , Franke Dieter , Gaedicke Christoph
Published: December 2013

We present deep seismic reflection images along two profiles collected in 2006 in the Wharton Basin offshore Northern Sumatra. The main profile is located subparallel to the Sumatran trench at a distance of 32–66 km. Faulting of the entire sedimentary section (strike‐slip deformation sometimes accompanied by a dip‐slip component) is imaged over two fracture zones of the extinct Wharton Spreading Center that prior studies have shown to be reactivated as left‐lateral faults. The western fracture zone is associated with a wide region of strong basement topography, a difference in crustal thickness of ~1.5 km, and an age offset of 9 Ma. The epicenters of the 11 April 2012 Mw 8.6 great strike‐slip earthquake, its Mw 7.2 foreshock, and Mw 8.2 aftershock align along this major structure > 100 km south of the profile intersection. Our high‐quality long‐offset seismic reflection data also reveal bright dipping reflections extending down to a maximum of ~24 km into the oceanic mantle (~37 km below sea level). Apparent dips are mostly 25–35°, corresponding to 30–55° along either N‐S to NNE‐SSW or E‐W to WNW‐ESE directions, which encompass the directions of plate fabric and nodal planes of the Mw 8.6 event. We suggest that these enigmatic reflections arise from presently inactive dip‐slip fault planes reaching for the deepest ones to the base of the brittle layer. Possible origins include extension related to plate bending or an episode of now inactive thrust‐type deformation reactivating paleonormal faults, similar to that taking place in the Central Indian Basin.
Lunar heat flow: Regional prospective of the Apollo landing sites
Authors: Siegler M. A. , Smrekar S. E.
Published: December 2013

We reexamine the Apollo Heat Flow Experiment in light of new orbital data. Using three‐dimensional thermal conduction models, we examine effects of crustal thickness, density, and radiogenic abundance on measured heat flow values at the Apollo 15 and 17 sites. These models show the importance of regional context on heat flux measurements. We find that measured heat flux can be greatly altered by deep subsurface radiogenic content and crustal density. However, total crustal thickness and the presence of a near‐surface radiogenic‐rich ejecta provide less leverage, representing only minor (<1.5 mW m−2) perturbations on surface heat flux. Using models of the crust implied by Gravity Recovery and Interior Laboratory results, we found that a roughly 9–13 mW m−2 mantle heat flux best approximate the observed heat flux. This equates to a total mantle heat production of 2.8–4.1 × 1011 W. These heat flow values could imply that the lunar interior is slightly less radiogenic than the Earth's mantle, perhaps implying that a considerable fraction of terrestrial mantle material was incorporated at the time of formation. These results may also imply that heat flux at the crust‐mantle boundary beneath the Procellarum potassium, rare earth element, and phosphorus (KREEP) Terrane (PKT) is anomalously elevated compared to the rest of the Moon. These results also suggest that a limited KREEP‐rich layer exists beneath the PKT crust. If a subcrustal KREEP‐rich layer extends below the Apollo 17 landing site, required mantle heat flux can drop to roughly 7 mW m−2, underlining the need for future heat flux measurements outside of the radiogenic‐rich PKT region.
Single‐event upsets in the Cluster and Double Star Digital Wave Processor instruments
Authors: Yearby K. H. , Balikhin M. , Walker S. N.
Published: December 2013

Radiation‐induced upsets are an important issue for electronic circuits operating in space. Upsets due to solar protons, trapped protons, and galactic cosmic rays are frequently observed. Modeling the expected frequency of upsets is a necessary part of the design process for space hardware. The Cluster and Double Star spacecraft were respectively European and Chinese missions dedicated to the study of the wave and particle environment in the Earth's magnetosphere. All four Cluster spacecraft and one Double Star spacecraft included a Digital Wave Processor (DWP) instrument. The primary purpose of this instrument was as the central controller of the Wave Experiment Consortium. This paper investigates the occurrence of radiation‐induced single‐event upsets in these DWP instruments. The memory devices used in the DWP were not specifically radiation‐hardened parts and so are relatively sensitive to single‐event effects. We present the experience gained during the first 11 years of operation of the Cluster mission and the nearly 4 year lifetime of the Double Star TC‐1 spacecraft and compare with models of the radiation environment.
M13 Bacteriophage as Materials for Amplified Surface Enhanced Raman Scattering Protein Sensing
Authors: Lee Ju Hun , Xu Phyllis F. , Domaille Dylan W. , Choi Chulmin , Jin Sungho , Cha Jennifer N.
Published: December 2013

Because of their unique properties, nanomaterials have been actively investigated in recent years for biosensing applications. A typical approach for biomarker detection is to attach capture or detection antibodies to nanomaterials, allow the analyte to bind, and measure the resulting change in signal. While antibodies or aptamers possess at most one binding site each for the nanomaterial and analyte, it is shown that the high surface area filamentous M13 bacteriophage can be utilized as a scaffold for generating an amplified signal. Since only a few proteins at the tip of the micrometer‐long virus are involved in antigen binding, the rest of the bacteriophage can be augmented with hundreds of functional groups, each of which can bind to a specific nanomaterial. It is demonstrated that the combination of DNA‐modified M13 bacteriophage and surface enhanced Raman spectroscopy (SERS) active nanoparticles can be used to produce exponential gains in Raman signal compared to that of antibodies at the same antigen concentration. Because of these high sensitivities, Raman measurements can be made directly from individual silica microparticles, potentially enabling future single step identification and analysis of different proteins in complex mixtures, while avoiding additional processing steps or prepatterned microarrays.
Palladium‐Catalyzed Desulfitative Direct CH Arylation of Electron‐Deficient Polyfluoroarenes with Sodium Arenesulfinates
Authors: Miao Tao , Wang Lei
Published: December 2013

The palladium‐catalyzed direct arylation of electron‐deficient polyfluorobenzenes was developed in the presence of silver carbonate and trisodium phosphate. This protocol allowed use of both electron‐deficient and electron‐rich aromatic sulfinic acid sodium salts as arylating reagents for the direct arylation of a variety of polyfluoroarenes to produce fluorobiaryls in good to excellent yields, providing a complement to the existing methods for the direct arylation of polyfluoroarenes.

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Regio‐ and Enantioselective Monoborylation of Alkenylsilanes Catalyzed by an Electron‐Donating Chiral Phosphine–Copper(I) Complex
Authors: Kubota Koji , Yamamoto Eiji , Ito Hajime
Published: December 2013

An asymmetric monoborylation of alkenylsilanes catalyzed by a copper(I) complex with the chiral bisphosphine ligand BenzP* is reported. The reaction proceeded with excellent regioselectivity and high enantioselectivity to afford the corresponding optically active organoboronate esters with a stereogenic CB bond containing a vicinal silyl group. The synthetic utility of the product is demonstrated through stepwise transformations to multifunctional optically active compounds in a stereospecific manner.

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Organocatalyst‐Mediated Dehydrogenation of Aldehydes to α,β‐Unsaturated Aldehydes, and Oxidative and Enantioselective Reaction of Aldehydes and Nitromethane Catalyzed by Diphenylprolinol Silyl Ether
Authors: Hayashi Yujiro , Itoh Takahiko , Ishikawa Hayato
Published: December 2013

A one‐pot transformation of aldehydes into α,β‐unsaturated aldehydes was developed using both N‐benzyl‐N‐methylamine and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) as catalysts and MnO2 as a terminal oxidant. An oxidative and enantioselective reaction of aldehydes and nitromethane was established using both diphenylprolinol silyl ether and DDQ as a catalyst with MnO2 as a terminal oxidant, in which synthetically important β‐substituted γ‐nitro aldehydes were obtained with excellent enantioselectivity.

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A Uranium‐Based UO2+–Mn2+ Single‐Chain Magnet Assembled trough Cation–Cation Interactions
Authors: Mougel Victor , Chatelain Lucile , Hermle Johannes , Caciuffo Roberto , Colineau Eric , Tuna Floriana , Magnani Nicola , de Geyer Arnaud , Pécaut Jacques , Mazzanti Marinella
Published: December 2013

Single‐chain magnets (SCMs) are materials composed of magnetically isolated one‐dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide‐containing SCM. The 5f–3d heterometallic 1D chains [{[UO2(salen)(py)][M(py)4](NO3)}]n, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation–cation interaction from the reaction of the uranyl(V) complex [UO2(salen)py][Cp*2Co] (Cp*=pentamethylcyclopentadienyl) with Cd(NO3)2 or Mn(NO3)2 in pyridine. The infinite UMn chain displays a high relaxation barrier of 134±0.8 K (93±0.5 cm−1), probably as a result of strong intra‐chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T<6 K, with an impressive coercive field of 3.4 T at 2 K.
Helicenes with Embedded Phosphole Units in Enantioselective Gold Catalysis
Authors: Yavari Keihann , Aillard Paul , Zhang Yang , Nuter Frédérick , Retailleau Pascal , Voituriez Arnaud , Marinetti Angela
Published: December 2013

This paper discloses the first uses of phosphahelicenes as chiral ligands in transition‐metal catalysis. Unlike all known helical phosphines used so far in catalysis, the phosphorus function of phosphahelicenes is embedded in the helical structure itself. This crucial structural feature originates unprecedented catalytic behaviors and efficiency. An appropriate design and fine tuning allowed both high catalytic activity and good enantiomeric excesses to be attained in the gold promoted cycloisomerizations of N‐tethered 1,6‐enynes and dien‐ynes.