bluuebunny/crossref_metadata_2025 huggingface dataset:
Post Etch Residue Removal and Material Compatibility in BEOL Using Formulated Chemistries
Authors: Kesters Els , Le Q.T. , Yu D. , Shen M. , Braun S. , Klipp A. , Holsteyns F.
Published: September 2014

A possible way to realize a 22.5 nm 1⁄2 pitch and beyond BEOL interconnect structures within the low-kmaterial is the partial-trench via first with self-aligned double patterning (SADP) integration approach. A scheme of this BEOL integration stack with the different materials used after patterning is described in Figure 1. In BEOL processing, fluorocarbon-containing plasma is commonly used to pattern silica-based dielectric layers. During the patterning of the low-kdielectric layer, a thin layer of fluoropolymer (CFx-type residues) is intentionally deposited on the dielectric sidewalls and TiN hardmask to ensure anisotropic etching and prevent/minimize dielectric degradation. This polymer layer must be removed from the sidewall and the via bottom prior to the subsequent processing steps to achieve good adhesion and coverage of materials deposited in the etched features. The compatibility requirement is even more stringent for advanced low-kdielectrics, i.e. materials with lowerk-value and higher porosity. The post etch residue (PER) amount and properties are specific and depend on the stack structure and the plasma that is used for patterning. The low-kmaterials and hardmasks that are used in this work are respectively an organo-silicate glass (OSG) type of low-kmaterial withk= 2.4 (~20 % open porosity) and low-stress TiN. Recent results clearly showed the presence of a highly fluorinated layer deposited on the trench sidewalls during the plasma etch based on a fluorocarbon plasma [1-3]. Commodity aqueous cleaning solutions, such as diluted HF, do not efficiently remove the sidewall polymers without etching the underlying layer (lift-off). Therefore, there is a need for commercially available chemicals that can be easily tuned to deal with the different requirements. This study focuses on the use of FOTOPUR® R 2300 mixed with H2O2 for polymer residue removal selectively to other materials (presented in the stack) such as MHM, metals (Cu, W), and porous low-k dielectrics. We will show that TiN etch can be easily tuned by changing the concentration of H2O2.
Scaling the 3D Bumps Pitch from 20 to 10 μm, Focusing on the Wet Cu Seed Etch Process Development
Authors: Suhard Samuel , Moussa A. , Slakkeboorn J. , Beirnaert F. , de Preter I. , Holsteyns F.
Published: September 2014

Within 3D stacked integrated circuits (3D-SIC), the fabrication of well-defined and solid microbumps is required. These bumps are typically being processed in presence of probing metal such as Al in order to stack functioning dies [1]. As a result of the variety of metals present and the continuous microbump downscaling towards 10 μm, more selective Cu seed etch chemistries are being screened. These Cu seed etch chemistries should be compatible with a variety of metals (Ni, Sn, Al, Co) and generate bumps without undercut and acceptable lateral etch (< 300 nm/side for 20 μm and < 150 nm/side for 10 μm). However the lateral etch specifications were just met for 20 μm [2] and will be more stringent for 10 μm, especially as the lateral etch specification are within the same range as the Cu seed layer thickness (150 nm). Additionally, the current seed etch process is yielding rough bumps (Rs >15 nm) whereas our target is set to be <12 nm in order to guarantee a good electrical contact.
Retardation Phenomenon of Oxide Removal during the Formation of Dual Gate Oxide via PR-Mask Wet Etching
Authors: Ko Ki Hyung , Song Myung Geun , Cho Byung Kwon , Yoon Bo Un , Cho Yu Jin , Kim Tae Sung
Published: September 2014

PR-mask oxide wet etching process is generally applied for the formation of dual gate oxide (Gox) transistor (TR) with different thickness of gate oxide. Oxide residues, which could not be removed properly with conventional wet etching process by dHF was observed when PR rework process by strip with SPM and SC1 was preceded before oxide wet etching. The root cause on this oxide removal retardation issue was studied by XPS for the analysis of surface element, SEM for the observation of surface morphology and optical spectroscopy for the measurement of thickness of oxide. It was found that PR rework process is main factor for oxide residue, because no unetched oxide layer was observed after dHF etching if there was no PR rework. A model test showed that when NH4OH component was included during PR rework process, retardation of oxide etching was occurred. The abnormal high content of carbon ingredient on oxide surface after NH4OH treatment with SC1 or NH4OH only solution shows that some kind of blocking layer generated upon adsorbed NH4OH molecules on oxide surface may hinder oxide wet etching by HF. It is postulated that anionic molecules such as PAG (photoacid generator) or anionic surfactant arisen from PR developing process may be able to combine with NH4OH molecules, forming complex layer by electrostatic interaction. This assumption was clearly verified that no oxide residues was found after dHF etching if ozonated water (O3 DIW) treatment was applied between PR developing and oxide wet etching step, since O3DIW can remove organic component with high efficiency, resulting the elimination of blocking layer for wet etching process.
Correlation of Cleaning Conditions and Wafer Out-Gassing
Authors: Han Sok Hyung , Hwang Tae Ho , Kim Si Chul , Park Seung Ha , Ryu Byung Sul
Published: September 2014

To remove the oxide layer, BOE (Buffered Oxide Etchant) is widely used solution in semiconductor fabrication process. When using the BOE solution in single type equipment, NH3 ions are created by the chemical reaction. Because BOE is a mixture solution of NH4F and HF. And created NH3 ions make some problems during device fabrication process. As the device is shrinked, NH3 ion control in process chamber becomes more important. We studied the thickness change caused by NH3 ion.When backside cleaning process using the BOE solution, surface of backside was changed. And it affected the next poly layer deposition process. As a result, poly layer deposition thickness dispersion problem was occurred. We find that the difference between normal wafer and issued wafer about backside layer and fumed NH3 ion is main factor of this problem. In this paper, we will explain the cause of poly thickness dispersion issue that occurred at poly film deposition and analyze measurement of cleaning conditions by NH3 out-gassing.Key Words: Poly deposition thickness, NH3+ ion, BOE(Buffered Oxide Etchant),APM(Ammonium Peroxide Mixture), Out-gassing
Simplified Cleaning for a-Si:H Passivation of Wafers Bonded to Glass
Authors: Granata Stefano Nicola , Bearda T. , Gordon I. , Abdulraheem Y. , Mertens R. , Poortmans J.
Published: September 2014

Silicon photovoltaic (PV) roadmaps indicate the reduction of wafer thicknesses and the need for innovation in wafering method and cell processing. Within this framework, Imec proposes the i2-module device [1], i.e. an heterojunction interdigitated back-contact (HJ i-BC) solar module [2] processed on 40-μm thick epitaxial wafers bonded to carriers by means of silicone. In the i2-module concept, the Rear Side (RS) of the solar cell is passivated while the wafer is bonded to the module glass and the influence of the silicone on the passivation process is reduced by an O2 plasma realized in an Reactive Ion Etching (RIE) chamber [3]. In this contribution, the effect of different post-bonding cleaning sequences on the passivation of wafers/silicone/glass stacks treated with an O2 plasma is investigated and a simplified post-bonding cleaning sequence leading to state-of-the-art passivation is proposed.
Metal Removal Efficiency in Deep Submicron Trenches by Wet Chemicals
Authors: Garnier Philippe , Drogue Nathalie , Duru Romain
Published: September 2014

Metal contamination impact on transistors’ degradation has been widely studied. Nonetheless, most of the work has been performed on blanket wafers, or based on punctual yield crisis during the integrated circuits’ manufacturing. This paper proposes a comparison of the contamination and metals removal efficiency between blanket wafers and inside deep silicon trenches.
Operation of a New Electrolyzed Cell Using Boron Doped Diamond Electrodes
Authors: Fryda M. , Mathée Th. , Oshinowo John , Baek D.H. , Förster H. J. , Heinze G.
Published: September 2014

The definition of sub-20 nm electronic devices for the newest generation of smart phones, computer and automotive is calling for very innovative FEOL wet chemical cleans. The electronic properties are very sensitive, in respect of the surface morphology on a Si-wafer. Most of the modern wet cleans are based on the RCA-clean [1]. Innovative cleans, like for example the IMEC-clean [2] and modified RCA clean were developed, using ozone-DIW mixture (O3-DIW), in order to improve the cleaning performance [3], [4]. Since several years electrolyzed water (EW) is used in semiconductor manufacturing [5]. An electrochemical reaction is induced by an electrode and a small amount of ammonia hydroxide (NH4OH) or ammonia sulfate and DIW [7].
Nanoscale Etching and Reoxidation of InAs
Authors: van Dorp Dennis H. , Arnauts S. , Cuypers D. , Rip J. , Holsteyns F. , De Gendt S.
Published: September 2014

At present, the performance enhancement for Si-based transistors can no longer be guaranteed due to intrinsic mobility issues. The considerably higher electron mobility of III-V compound semiconductors (e.g. InGaAs, InAs, InSb) has led to renewed interest and a following phase in the development of future transistors for the 7-5 nm technology node [1].
Watermark Formation on Bare Silicon: Impact of Illumination and Substrate Doping
Authors: Tamaddon Amir Hossein , Philipsen Harold , Mertens Paul W. , Holsteyns Frank , Heyns Marc , De Gendt Stefan , van Dorp Dennis H.
Published: September 2014

The wet cleaning process plays an important role in advanced semiconductor industry. Particularly when bare silicon areas are exposed, wafer drying can result in undesired watermark (WM) residues on the surface [1-2]. In principle there are three components effecting the formation, shape and size of WM. 1) composition of the ambient like oxygen concentration, relative humidity and temperature affect WM formation [3]. 2) liquid: factors such as pH and the amount of dissolved species inside the liquid influence the WM composition. 3) substrate: for silicon for instance: surface passivation is important for WM formation [2]. WMs are composed of silica that is formed during the drying process by oxidation of the silicon surface [1]. Therefore when studying WM formation it is important to understand the mechanism (s) of silicon oxidation and the dissolution.
Extension and Comparative Study of AUSM-Family Schemes for Compressible Multiphase Flow Simulations
Authors: Kitamura Keiichi , Liou Meng-Sing , Chang Chih-Hao
Published: September 2014

Several recently developed AUSM-family numerical flux functions (SLAU, SLAU2, AUSMM+-up2, and AUSMPW+) have been successfully extended to compute compressible multiphase flows, based on the stratified flow model concept, by following two previous works: one by M.-S. Liou, C.-H. Chang, L. Nguyen, and T.G. Theofanous [AIAA J. 46:2345-2356, 2008], in which AUSM+-up was used entirely, and the other by C.-H. Chang, and M.-S. Liou [J. Comput. Phys. 225:840-873, 2007], in which the exact Riemann solver was combined into AUSM+-up at the phase interface. Through an extensive survey by comparing flux functions, the following are found: (1) AUSM+-up with dissipation parameters of Kp and Ku equal to 0.5 or greater, AUSMPW+, SLAU2, AUSM+-up2, and SLAU can be used to solve benchmark problems, including a shock/water-droplet interaction; (2) SLAU shows oscillatory behaviors [though not as catastrophic as those of AUSM+ (a special case of AUSM+-up with Kp = Ku = 0)] due to insufficient dissipation arising from its ideal-gas-based dissipation term; and (3) when combined with the exact Riemann solver, AUSM+-up (Kp = Ku = 1), SLAU2, and AUSMPW+ are applicable to more challenging problems with high pressure ratios.
Finding Critical Nuclei in Phase Transformations by Shrinking Dimer Dynamics and its Variants
Authors: Zhang Lei , Zhang Jingyan , Du Qiang
Published: September 2014

We investigate the critical nuclei morphology in phase transformation by combining two effective ingredients, with the first being the phase field modeling of the relevant energetics which has been a popular approach for phase transitions and the second being shrinking dimer dynamics and its variants for computing saddle points and transition states. In particular, the newly formulated generalized shrinking dimer dynamics is proposed by adopting the Cahn-Hilliard dynamics for the generalized gradient system. As illustrations, a couple of typical cases are considered, including a generic system modeling heterogeneous nucleation and a specific material system modeling the precipitate nucleation in FeCr alloys. While the standard shrinking dimer dynamics can be applied to study the non-conserved case of generic heterogeneous nucleation directly, the generalized shrinking dimer dynamics is efficient to compute precipitate nucleation in FeCr alloys due to the conservation of concentration. Numerical simulations are provided to demonstrate both the complex morphology associated with nucleation events and the effectiveness of generalized shrinking dimer dynamics based on phase field models.
Horizontal distributions of aerosol constituents and their mixing states in Antarctica during the JASE traverse
Authors: Hara K. , Nakazawa F. , Fujita S. , Fukui K. , Enomoto H. , Sugiyama S.
Published: September 2014

Abstract. Measurements of aerosol number concentrations and direct aerosol sampling were conducted on continental Antarctica during the traverse of the Japanese–Swedish joint Antarctic expedition (JASE) from 14 November 2007 until 24 January 2008. Aerosol concentrations in background conditions decreased gradually with latitude in inland regions during the traverse. The lowest aerosol number concentrations were 160 L−1 in Dp > 0.3 μm, and 0.5 L−1 in Dp 2 μm. In contrast, aerosol concentrations reached 3278 L−1 in Dp > 0.3 μm, and 215 L−1 in Dp > 2 μm under strong wind conditions. The estimated aerosol mass concentrations were 0.04–5.7 μg m−3. Single particle analysis of aerosol particles collected during the JASE traverse was conducted using a scanning electron microscope equipped with an energy dispersive x ray spectrometer. Major aerosol constituents were sulfates in fine mode, and sulfate, sea salts, modified sea salts, and fractionated sea salts in coarse mode. K-rich sulfates, Mg-rich sulfate, Ca-rich sulfates, and minerals were identified as minor aerosol constituents. Horizontal features of Cl / Na ratios imply that sea-salt modification (i.e. Cl loss) occurred on the Antarctic continent during the summer. Most sea-salt particles in the continental region near the coast were modified with acidic sulfur species such as H2SO4 and CH3SO3H. By contrast, acidic species other than the acidic sulfur species (likely HNO3) contributed markedly to sea-salt modification in inland areas during the traverse. Mg-rich sea-salt particles and Mg-free sea-salt particles were present in coarse and fine modes from the coast to inland areas. These sea-salt particles might be associated with sea-salt fractionation on the snow surface of continental Antarctica.
Modeling analysis of the seasonal characteristics of haze formation in Beijing
Authors: Han X. , Zhang M. , Gao J. , Wang S. , Chai F.
Published: September 2014

Abstract. The air quality modeling system RAMS-CMAQ (Regional Atmospheric Modeling System–Community Multiscale Air Quality), coupled with an aerosol optical property scheme, was applied to simulate the meteorological field, major aerosol components (sulfate, nitrate, ammonium, black carbon, organic carbon, dust, and sea salt), and surface visibility over the North China Plain (NCP) in 2011. The modeled results in February and July 2011 were selected and analyzed to obtain an in-depth understanding of the haze formation mechanism in Beijing for different seasons. The simulation results showed that the visibility was below 10 km for most regions of the NCP, and dropped to less than 5 km over the megacities of Beijing and Tianjin, the whole of Hebei Province, and the northwest part of Shandong Province during pollution episodes in February and July. The heavy mass concentration of PM2.5 ranged from 120 to 300 μg m−3 and was concentrated in the areas with low visibility. The haze formation mechanism in Beijing in winter was different from that in summer. The mass concentration of PM2.5 was higher, and the components more complicated, in winter. While the mass concentration of PM2.5 in summer was lower than that in winter, the mass concentrations of hygroscopic inorganic salts were comparable with those in winter, and the relative humidity was, as expected, higher. Therefore, the water uptake of hygroscopic aerosols played a key role in summer. Moreover, the analysis showed that the influence of the PM2.5 mass burden on visibility was very weak when its value was larger than 100 μg m−3. Only when the mass burden of PM2.5 decreased to a certain threshold interval did the visibility increase rapidly. This indicates that, when emission reduction measures are taken to control haze occurrence, the mass burden of PM2.5 must be cut to below this threshold interval. The relationship between the threshold of haze occurrence and the relative humidity in Beijing was fitted by an exponential function, and the resulting fitting curves could provide a new theoretical basis to understand and control haze formation in Beijing.
Investigation of secondary formation of formic acid: urban environment vs. oil and gas producing region
Authors: Yuan B. , Veres P. R. , Warneke C. , Roberts J. M. , Gilman J. B. , Koss A. , Edwards P. M. , Graus M. , Kuster W. C. , Li S.-M. , Wild R. J. , Brown S. S. , Dubé W. P. , Lerner B. M. , Williams E. J. , Johnson J. E. , Quinn P. K. , Bates T. S. , Lefer B. , Hayes P. L. , Jimenez J. L. , Weber R. J. , Zamora R. , Ervens B. , Millet D. B. , Rappenglück B. , de Gouw J. A.
Published: September 2014

Abstract. Formic acid (HCOOH) is one of the most abundant carboxylic acids in the atmosphere. However, current photochemical models cannot fully explain observed concentrations and in particular secondary formation of formic acid across various environments. In this work, formic acid measurements made at an urban receptor site in June–July of 2010 during CalNex and a site in an oil and gas producing region in January–February of 2013 during UBWOS 2013 will be discussed. Although the VOC compositions differed dramatically at the two sites, measured formic acid concentrations were comparable: 2.3 ± 1.3 ppb in UBWOS 2013 and 2.0 ± 1.0 ppb in CalNex. We determine that concentrations of formic acid at both sites were dominated by secondary formation (> 8%). A constrained box model using the Master Chemical Mechanism (MCM v3.2) underestimates the measured formic acid concentrations drastically at both sites (by a factor of > 10). Inclusion of recent findings on additional precursors and formation pathways of formic acid in the box model increases modeled formic acid concentrations for UBWOS 2013 and CalNex by a factor of 6.4 and 4.5, respectively. A comparison of measured and modeled HCOOH/acetone ratios is used to evaluate the model performance for formic acid. We conclude that the modified chemical mechanism can explain 21 and 47% of secondary formation of formic acid in UBWOS 2013 and CalNex, respectively. The contributions from aqueous reactions in aerosol and heterogeneous reactions on aerosol surface to formic acid are estimated to be −7 and 0–6% in UBWOS 2013 and CalNex, respectively. We observe that air-snow exchange processes and morning fog events may also contribute to ambient formic acid concentrations during UBWOS 2013 (∼20% in total). In total, 50–57% in UBWOS 2013 and 48–53% in CalNex of secondary formation of formic acid remains unexplained. More work on formic acid formation pathways is needed to reduce the uncertainties in the sources and budget of formic acid and to narrow the gaps between measurements and model results.
Urban MEMS based seismic network for post-earthquakes rapid disaster assessment
Authors: D'Alessandro A. , Luzio D. , D'Anna G.
Published: September 2014

Abstract. In this paper, we introduce a project for the realization of the first European real-time urban seismic network based on Micro Electro-Mechanical Systems (MEMS) technology. MEMS accelerometers are a highly enabling technology, and nowadays, the sensitivity and the dynamic range of these sensors are such as to allow the recording of earthquakes of moderate magnitude even at a distance of several tens of kilometers. Moreover, thanks to their low cost and smaller size, MEMS accelerometers can be easily installed in urban areas in order to achieve an urban seismic network constituted by high density of observation points. The network is being implemented in the Acireale Municipality (Sicily, Italy), an area among those with the highest hazard, vulnerability and exposure to the earthquake of the Italian territory. The main objective of the implemented urban network will be to achieve an effective system for post-earthquake rapid disaster assessment. The earthquake recorded, also that with moderate magnitude will be used for the effective seismic microzonation of the area covered by the network. The implemented system will be also used to realize a site-specific earthquakes early warning system.
Nitrogen cycling in the Southern Ocean Kerguelen Plateau area: evidence for significant surface nitrification from nitrate isotopic compositions
Authors: Dehairs F. , Fripiat F. , Cavagna A.-J. , Trull T. W. , Fernandez C. , Davies D. , Roukaerts A. , Fonseca Batista D. , Planchon F. , Elskens M.
Published: September 2014

Abstract. This paper presents whole water column data for nitrate N, O isotopic composition for the Kerguelen Plateau area and the basin extending east of the island, aiming at understanding the N-cycling in this naturally iron fertilized area that is characterized by large re-current phytoplankton blooms. The KEOPS 2 expedition (October–November 2011) took place in spring season and complements knowledge gathered during an earlier summer expedition to the same area (KEOPS 1, February–March 2005). As noted by others a remarkable condition of the system is the moderate consumption of nitrate over the season (nitrate remains > 20 μM) while silicic acid becomes depleted, suggesting significant recycling of nitrogen. Nitrate isotopic signatures in the upper water column do mimic this condition, with surprising overlap of spring and summer regressions of δ18ONO3 vs. δ15NNO3 isotopic compositions. These regressions obey rather closely the 18ϵ/15ϵ discrimination expected for nitrate uptake (18ϵ/15ϵ = 1), but regression slopes as large as 1.6 were observed for the mixed layer above the Kerguelen Plateau. A preliminary mass balance calculation for the early bloom period points toward significant nitrification occurring in the mixed layer and which could account for up to 80 % of nitrate uptake above the Kerguelen Plateau. A further finding concerns deep ocean low δ18ONO3 values (< 2‰) underlying high chlorophyll waters at the Polar Front Zone and which cannot be explained by remineralisation and nitrification of the local particulate nitrogen flux, which is too small in magnitude. However, the studied area is characterised by a complex recirculation pattern that would keep deep waters in the area and could impose a seasonally integrated signature of surface water processes on the deep waters.
The relevance of uncertainty in future crop production for mitigation strategy planning
Authors: Frieler K. , Levermann A. , Elliott J. , Heinke J. , Arneth A. , Bierkens M. F. P. , Ciais P. , Clark D. B. , Deryng D. , Döll P. , Falloon P. , Fekete B. , Folberth C. , Friend A. D. , Gellhorn C. , Gosling S. N. , Haddeland I. , Khabarov N. , Lomas M. , Masaki Y. , Nishina K. , Neumann K. , Oki T. , Pavlick R. , Ruane A. C. , Schmid E. , Schmitz C. , Stacke T. , Stehfest E. , Tang Q. , Wisser D. , Huber V. , Piontek F. , Warszawski L. , Schewe J. , Lotze-Campen H. , Schellnhuber H. J.
Published: September 2014

Abstract. In order to achieve climate change mitigation, long-term decisions are required that must be reconciled with other societal goals that draw on the same resources. For example, ensuring food security for a growing population may require an expansion of crop land, thereby reducing natural carbon sinks or the area available for bio-energy production. Here, we show that current impact-model uncertainties pose an important challenge to long-term mitigation planning and propose a new risk-assessment and decision framework that accounts for competing interests. Based on cross-sectorally consistent simulations generated within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) we discuss potential gains and limitations of additional irrigation and trade-offs of the expansion of agricultural land as two possible response measures to climate change and growing food demand. We describe an illustrative example in which the combination of both measures may close the supply demand gap while leading to a loss of approximately half of all natural carbon sinks. We highlight current limitations of available simulations and additional steps required for a comprehensive risk assessment.
Nitrogen surface water retention in the Baltic Sea drainage basin
Authors: Stålnacke P. , Pengerud A. , Vassiljev A. , Smedberg E. , Mörth C.-M. , Hägg H. E. , Humborg C. , Andersen H. E.
Published: September 2014

Abstract. In this paper, we estimate the surface water retention of nitrogen (N) in all the 117 drainage basins to the Baltic Sea with the use of a statistical model (MESAW) for source apportionment of riverine loads of pollutants. Our results show that the MESAW model was able to estimate the N load at the river mouth of 88 Baltic Sea rivers, for which we had observed data, with a sufficient degree of precision and accuracy. The estimated retention parameters were also statistically significant. Our results show that around 380 000 t of N are annually retained in surface waters draining to the Baltic Sea. The total annual riverine load from the 117 basins to the Baltic Sea was estimated to 570 000 t of N, giving a total surface water N retention of around 40%. In terms of absolute retention values, three major river basins account for 50% of the total retention in the 117 basins; i.e. around 104 000 t of N is retained in Neva, 55 000 t in Vistula and 32 000 t in Oder. The largest retention was found in river basins with a high percentage of lakes as indicated by a strong relationship between N retention (%) and share of lake area in the river drainage areas. For example in Göta älv, we estimated a total N retention of 72%, whereof 67% of the retention occurred in the lakes of that drainage area (Lake Vänern primarily). The obtained results will hopefully enable the Helsinki Commission (HELCOM) to refine the nutrient load targets in the Baltic Sea Action Plan (BSAP), as well as to better identify cost-efficient measures to reduce nutrient loadings to the Baltic Sea.
Revision of the geological context of the Port-au-Prince metropolitan area, Haiti: implications for slope failures and seismic hazard assessment
Authors: Terrier M. , Bialkowski A. , Nachbaur A. , Prépetit C. , Joseph Y. F.
Published: September 2014

Abstract. Following the earthquake of 12 January 2010 in the Port-au-Prince area, the Haitian government, in close cooperation with BRGM, the French geological Survey, decided to undertake a seismic microzonation study of the metropolitan area of the capital in order to take more fully into account the seismic risk in the urbanization and planning of the city under reconstruction. As the first step of the microzonation project, a geological study has been carried out. Deposits of Miocene and Pliocene formations in a marine environment have been identified. These deposits are affected by the Enriquillo-Plantain Garden N80° E fault system and N110° E faults. Tectonic observations and morphological analysis indicate Quaternary activity of several faults mapped in the area of Port-au-Prince. These faults have a N110° trend and show a reverse-sinistral strike-slip motion. Moreover, on the basis of these geological results and of new topographical data, a hazard assessment of ground movements has been made. Along with the map of active faults, the hazard map of ground movements is an integral component of the seismic microzonation study.
Proposta de classificação das fontes potenciais de contaminação da água subterrânea
Authors: Iritani Mara Akie , Rossini-Penteado Denise , Ezaki Sibele , Oda Geraldo Hideo
Published: September 2014

Identificar as atividades que têm potencial de contaminar a água subterrânea auxilia na priorização de ações de proteção dos recursos hídricos, especialmente nas regiões com expressivo crescimento urbano e econômico. Nesse sentido, este trabalho apresenta o levantamento das fontes potenciais de contaminação nos municípios de Capivari, Elias Fausto, Indaiatuba, Monte Mor, Rafard e Salto (SP) e propõe uma classificação da carga contaminante associada, de forma a auxiliar na identificação de áreas com maior perigo de contaminação da água subterrânea. A metodologia para classificação é aqui denominada de POSH-IG e foi adaptada do consagrado método POSH (Pollutant Origin, Surcharge Hydraulically), que classifica a carga contaminante das fontes potenciais de contaminação em três níveis qualitativos (reduzido, moderado e elevado), com base na origem do contaminante e na existência de sobrecarga hidráulica que promova o transporte advectivo do contaminante ao aquífero. No método POSH-IG foram efetuadas adequações, como a inserção de parâmetros disponíveis no Sistema Paulista de Licenciamento Ambiental para a classificação da carga potencial contaminante das fontes pontuais e a integração de informações obtidas pelo mapeamento do uso e cobertura da terra, da tipologia e do padrão da ocupação para a classificação das fontes difusas, associadas aos sistemas de saneamento na área urbana e às atividades agropastoris na área rural. Além da avaliação das áreas de expansão urbana, foi também considerado como critério de classificação das fontes difusas relacionadas aos sistemas de saneamento, a densidade de ocupação das áreas de uso Residencial/Comercial/Serviços, como indicador indireto da densidade populacional. Foram cadastradas 1918 fontes pontuais de contaminação, sendo que os empreendimentos geradores de maior carga contaminante são as indústrias de produtos químicos, metalurgia, produtos metálicos, eletroeletrônicos e de engenharia mecânica, o comércio de produtos perigosos e a disposição inadequada de resíduos. A maior carga potencial de contaminação por fontes difusas nas áreas urbanas está concentrada nas porções mais antigas das cidades, onde ocorrem elevadas densidades de ocupação. A maior expressão em área ocorre nos municípios de Indaiatuba e Salto, onde houve intensa urbanização, e em Monte Mor, onde menos de 45% da cidade possui rede coletora de esgoto. Nas áreas rurais, a canavicultura, predominante nos municípios de Capivari e Rafard, destaca-se pelo elevado potencial de contaminação da água subterrânea.
Caracterização tecnológica para aproveitamento de matéria-prima sienítica com nefelina
Authors: Roveri Carolina Del , Godoy Letícia Hirata , Zanardo Antenor , Silva Luciano Luis da , Moreno Maria Margarita Torres , Navarro Fabiano Cabañas
Published: September 2014

Rochas sieníticas com nefelina que ocorrem em Lavrinhas (SP), a 234 km a nordeste da cidade de São Paulo, podem constituir-se numa potencial fonte mineral para fabricação de materiais cerâmicos. Com base na mineralogia e textura dessa matériaprima, buscou-se determinar os melhores métodos de beneficiamento mineral desse corpo sienítico como fundente. Também foram realizadas análises químicas e ensaios de fusibilidade para avaliar a cor de fusão do material antes e após a separação magnética, assim como seu potencial para uso em esmaltes e engobes, comparando-se com uma amostra comercial de Nefelina padrão. Os testes preliminares mostraram que após a retirada do óxido de ferro superficial esta matéria-prima portadora de nefelina tem potencial para ser utilizada na formulação de massas de porcelanato, em substituição de outros materiais fundentes de maior valor agregado.
Selecting pump impeller materials in a “lead‐free” environment
Authors: Devries Gavin
Published: September 2014

The transition to a “lead‐free” environment in the water industry has created unexpected challenges for water utilities trying to find acceptable materials that meet both this new requirement and still provide the same reliability as previously leaded materials.
Reasoning and Sense Making with Pythagoras
Authors: Roscoe Matt B.
Published: September 2014

Scaled-up versions of a triangle lead to uncommon proofs of the Pythagorean theorem and rich mathematical connections.
Classroom Strategies to Make Sense and Persevere
Authors: Wilburne Jane M. , Wildmann Tara , Morret Michael , Stipanovic Julie
Published: September 2014

A group of middle school teachers found that four strategies are effective when helping their students work through problems with understanding.
A Closer Look at Manipulatives in Remediation
Authors: Peppers Denise S. , Wan Anna , Phillips Hope E.
Published: September 2014

One teacher describes her action research with eight-grade prealgebra students who are working on a conceptual understanding of fractions.
Using iPads to Explore Parabolas
Authors: Bixler Sharon G.
Published: September 2014

Use an iPad® if you want your students to graph parabolas with ease and grasp vocabulary quickly. The Free Graphing Calculator app can be downloaded to explore axis of symmetry, roots, maxima, minima, and vertices.
Mapping Our World
Authors: Barta Jim , Kyriopoulos Joan
Published: September 2014

Travel with the authors to a rural village in Guatemala where students are integrating mathematics and social studies in a culturally situated context.
Employment Pattern of Nursing Graduates of NEUST
Authors: Guillasper Jean N.
Published: September 2014

Employment among nurses is one of the most sensationalized problems in the Philippines nowadays. Oversupply of fresh graduates and undersupply of experienced nurses is evident. The study aimed to determine the employment pattern of nursing graduates of Nueva Ecija University of Science and Technology in terms of their profile, professional information, and employment information of graduates of the said Higher Education Institution. The descriptive method of research was used in this study with the questionnaire as the main tool for data gathering. The data gathered were statistically treated, analyzed and interpreted. The study revealed that out of 1,047 respondents, 429 or 40.97% were employed; 284 or 27.13%, unemployed; 192 or 18.34%, underemployed; 136 or 12.99 were nurse trainee/volunteer and 6 or 0.57% were self-employed. It can be concluded that majority of nursing graduates was working in line with their course/profession and only few worked in non-hospital setting.
De novo interstitial deletion 2q14.1q22.1: Is there a recognizable phenotype?
Authors: Greally Marie T. , Robinson Eve , Allen Nicholas M. , O'Donovan Donough , Crolla John A.
Published: September 2014

In this report we describe a male patient with a rare de novo interstitial deletion of chromosome 2q14.1–q22.1. His karyotype was reported as 46,XY,del(2)(q13q21) but subsequent array comparative genomic hybridization (array CGH) analysis redefined the deletion breakpoints as 2q14.1 and 2q22.1. Eight patients have been reported with deletions either within or spanning the region 2q13 or 2q14 to 2q22.1. In five patients the diagnosis was made by karyotype analysis alone and in three reported patients and the proband array CGH analysis was also performed. When the proband was compared with the eight previously reported patients it was apparent that they shared many clinical findings suggesting that patients with a de novo interstitial deletion involving 2q13 or 2q14 to 2q21 or 2q22 may have a recognizable phenotype. There are 14 known disease‐associated genes in the deleted region of 2q14.1–q22.1 and their possible phenotypic effects on the proband and the eight previously reported patients are discussed. © 2014 Wiley Periodicals, Inc.
Geometry‐Assisted Three‐Dimensional Superlocalization Imaging of Single‐Molecule Catalysis on Modular Multilayer Nanocatalysts
Authors: Han Rui , Ha Ji Won , Xiao Chaoxian , Pei Yuchen , Qi Zhiyuan , Dong Bin , Bormann Nicholas L. , Huang Wenyu , Fang Ning
Published: September 2014

To establish the structure–catalytic property relationships of heterogeneous catalysts, a detailed characterization of the three‐dimensional (3D) distribution of active sites on a single catalyst is essential. Single‐particle catalysis of a modular multilayer catalytic platform that consists of a solid silica core, a mesoporous silica shell, and uniformly distributed Pt nanoparticles sandwiched in between these layers is presented. The first 3D high‐resolution super‐localization imaging of single fluorescent molecules produced at active sites on the core‐shell model nanocatalysts is demonstrated. The 3D mapping is aided by the well‐defined geometry and a correlation study in scanning electron microscopy and total internal reflection fluorescence and scattering microscopy. This approach can be generalized to study other nano‐ and mesoscale structures.
Targeting DNA G‐Quadruplexes with Helical Small Molecules
Authors: Müller Sebastian , Laxmi‐Reddy Katta , Jena Prakrit V. , Baptiste Benoit , Dong Zeyuan , Godde Frédéric , Ha Taekjip , Rodriguez Raphaël , Balasubramanian Shankar , Huc Ivan
Published: September 2014

We previously identified quinoline‐based oligoamide helical foldamers and a trimeric macrocycle as selective ligands of DNA quadruplexes. Their helical structures might permit targeting of the backbone loops and grooves of G‐quadruplexes instead of the G‐tetrads. Given the vast array of morphologies G‐quadruplex structures can adopt, this might be a way to achieve sequence selective binding. Here, we describe the design and synthesis of molecules based on macrocyclic and helically folded oligoamides. We tested their ability to interact with the human telomeric G‐quadruplex and an array of promoter G‐quadruplexes by using FRET melting assay and single‐molecule FRET. Our results show that they constitute very potent ligands—comparable to the best so far reported. Their modes of interaction differ from those of traditional tetrad binders, thus opening avenues for the development of molecules specific for certain G‐quadruplex conformations.
Redox‐Active Functionalized Graphene Nanoribbons as Electrode Material for Li‐Ion Batteries
Authors: Pirnat Klemen , Bitenc Jan , Jerman Ivan , Dominko Robert , Genorio Bostjan
Published: September 2014

Redox‐active organic materials offer high theoretical capacities; however, most organic materials show drastic capacity fading during cycling, mainly caused by the dissolution of the active materials in the electrolytes used in Li‐ion batteries. In this work, we introduced graphene nanoribbons (GNRs) with grafted electroactive molecules to serve as a current collector, binder, and active material at the same time. GNRs were prepared by unzipping commercially available multi‐walled carbon nanotubes with a Na/K alloy, functionalizing them in situ with different protected hydroquinone derivatives, which were later deprotected in the last step. All synthesized materials were electrochemically characterized in Li‐ion battery cells. The physical characteristics of the synthesized materials were determined by using evolved‐gas analysis, Raman spectroscopy, and scanning electron microscopy. These analyses show the successful functionalization of GNRs and improved electrochemical performance compared to non‐functionalized GNRs.
Oil|Water Interfacial Phosphate Transfer Facilitated by Boronic Acid: Observation of Unusually Fast Oil|Water Lateral Charge Transport
Authors: Li Meng , Lewis Grace E. M. , James Tony D. , Long Yi‐Tao , Kasprzyk‐Hordern Barbara , Mitchels John M. , Marken Frank
Published: September 2014

The front cover artwork is provided by the groups of Prof. Tony D. James, Prof. Frank Marken, Dr. Barbara Kasprzyk‐Hordern and Dr. John M. Mitchels (University of Bath, UK) as well as Prof. Yi‐Tao Long (East China University of Science and Technology, P.R. China). The image shows a coupled electron transfer–phosphate transfer, which is driven between two electrodes to provide a phosphate‐sensitive current response. Read the full text of the article at 10.1002/celc.201402181.
The Readout of Base‐Pair Information in Adenine–Thymine α‐D‐Arabinonucleosides
Authors: He Shiliang , Zhao Hang , Guo Xiurong , Xu Xiaoping , Zhou Xinglong , Liu Jiang , Xing Zhihua , Ye Ling , Jiang Lu , Chen Qianming , He Yang
Published: September 2014

Structurally modified nucleosides are central players in the field of nucleic acid chemistry. Adenine–thymine (AT) pyrimido[4,5‐d]pyrimidine furanosyl and pyranosyl arabinonucleosides have been synthesized for the first time. Single‐crystal X‐ray diffraction analysis reveals novel base pairs that, in synergy with the sugar residues, direct the emergence of distinct networks containing channels and cavities. The microscopic noncovalent connections can be translated into macroscopic levels in which robust organogels are formed by the furanoside but not the pyranoside. The influences of the sugars are also displayed by the different shaped superstructures of the free nucleosides in solution. The readout of the information in the base moiety is therefore tailored by the sugar configuration, and the interplays exert subtle effects on the structures, from solid to gel and to the solution state. The potential for forming these appealing base pairs and higher structures enables these intriguing nucleosides to serve as unique building blocks in various areas or to construct innovative nucleic acid structures.
A Look Back at the 17th International Symposium on Silicon Chemistry jointly with 7th European Silicon Days
Authors: Deveson Anne
Published: September 2014

Silicon slams: This Editorial looks back at the week of stimulating and fun silicon chemistry presented at the 17th International Symposium on Silicon Chemistry in Berlin.
Bevacizumab and glioblastoma: Scientific review, newly reported updates, and ongoing controversies
Authors: Field Kathryn M. , Jordan Justin T. , Wen Patrick Y. , Rosenthal Mark A. , Reardon David A.
Published: September 2014

Anti‐angiogenic therapy for glioblastoma has been in the spotlight for several years, as researchers and clinicians strive to find agents with meaningful efficacy against glioblastoma. Bevacizumab in particular, in the second half of the last decade, became the most significant breakthrough in anti‐glioblastoma therapy since temozolomide. Optimism for bevacizumab has been somewhat challenged given recent clinical trials that have raised questions regarding its clinical effectiveness, the optimal timing of its use and the validity of endpoints, among other issues. In addition, uncertainty has recently arisen regarding the effects of bevacizumab on quality of life and neurocognitive function, two key clinical endpoints of unquestionable significance among glioblastoma patients. In this review, we highlight these controversies and other recent work related to bevacizumab for glioblastoma. Cancer 2015;121:997–1007. © 2014 American Cancer Society.
Theoretical Vibrational Raman and Surface‐Enhanced Raman Scattering Spectra of Water Interacting with Silver Clusters
Authors: Sanchéz‐Lozano Marta , Mandado Marcos , Pérez‐Juste Ignacio , Hermida‐Ramón Jose M.
Published: September 2014

In this study, we analyzed the Raman spectrum of a water molecule adsorbed on a cluster of 20 silver atoms, and the plasmonic electromagnetic effect of the silver surface was also considered to give a theoretical prediction of the surface‐enhanced Raman scattering spectrum. The calculations were performed at the density functional theory (DFT) level by using both frozen and unfrozen silver clusters. Two different models were used to consider the plasmonic enhancement; one of them was a modified classical (dipole) model and the other was the coupled perturbed Hartree–Fock method with excitation frequencies obtained from time‐dependent DFT calculations and with proper detuning of these frequencies. The importance of small geometrical distortions of the silver surface in the orientation of the adsorbed water was shown. Moreover, it was shown how the symmetry of the transition dipole moment and the symmetry of the vibrational modes influence the Raman intensities of the SERS spectrum.
Integrated, Cascading Enzyme‐/Chemocatalytic Cellulose Conversion using Catalysts based on Mesoporous Silica Nanoparticles
Authors: Lee Yi‐Chun , Dutta Saikat , Wu Kevin C.‐W.
Published: September 2014

This article reports a novel approach to deconstructing cellulose into 5‐hydroxymethylfurfural (HMF) with a high yield (46.1 %) by integrating a sequential enzyme cascade technique in an aqueous system with solid acid catalysis in an organic‐solvent system. We executed the rational design and synthesis of mesoporous silica nanoparticles (MSNs) with various pore sizes and surface functionalities, which proved to be useful for the immobilization of various enzymes (i.e., cellulase and isomerase) and nanoparticles (i.e., magnetic Fe3O4) and for functionalization of various acid groups (i.e., H2PO3, COOH, and SO3H). We separately applied the synthesized biocatalysts (i.e., cellulase‐Fe3O4@MSN and isomerase‐Fe3O4@MSN) and chemical catalysts (i.e., HSO3‐MSN) in a sequential cellulose‐to‐glucose, glucose‐to‐fructose, and fructose‐to‐HMF conversion, respectively, across both aqueous‐ and organic‐solvent systems after the optimization of reaction conditions (e.g., reaction temperature, water ratio, catalyst amount). The integrated enzymatic and chemocatalytic concept in this study could be an effective and economically friendly process for various catalytic applications.
Oxidative (Cross‐)Coupling Reactions Mediated by C–H Activation of Thiophene Derivatives by Using Molybdenum(V) Reagents
Authors: Schubert Moritz , Trosien Simon , Schulz Lara , Brandscheid Carolin , Schollmeyer Dieter , Waldvogel Siegfried R.
Published: September 2014

Oxidative coupling by using molybdenum pentachloride provides fast and modular access to sophisticated thienoacenes in excellent yields. The coupling process can be accomplished with thiophene and benzothiophene derivatives and provides various complex skeletons such as spirocyclic compounds. In this approach, the first cross‐coupling reactions with the use of MoCl5 were established and important motifs for semiconducting materials were synthesized.
Capillary electrophoresis in two‐dimensional separation systems: Techniques and applications
Authors: Kohl Felix J. , Sánchez‐Hernández Laura , Neusüß Christian
Published: September 2014

The analysis of complex samples requires powerful separation techniques. Here, 2D chromatographic separation techniques (e.g. LC‐LC, GC‐GC) are increasingly applied in many fields. Electrophoretic separation techniques show a different selectivity in comparison to LC and GC and very high separation efficiency. Thus, 2D separation systems containing at least one CE‐based separation technique are an interesting alternative featuring potentially a high degree of orthogonality. However, the generally small volumes and strong electrical fields in CE require special coupling techniques. These technical developments are reviewed in this work, discussing benefits and drawbacks of offline and online systems. Emphasis is placed on the design of the systems, their coupling, and the detector used. Moreover, the employment of strategies to improve peak capacity, resolution, or sensitivity is highlighted. Various applications of 2D separations with CE are summarized.