bluuebunny/crossref_metadata_2025 huggingface dataset:
Grain Refinements of Cu6Sn5 in Sn-3wt%Ag-5wt%Cu High Temperature Solder Alloys
Authors: Tan Xin Fu , Mohd Salleh Mohd Arif Anuar , McDonald Stuart D. , Nogita Kazuhiro
Published: June 2018

This paper investigated the effect of trace addition of Al and Mg on the grain refinements of Cu6Sn5in Sn-3wt%Ag-5wt%Cu high temperature solder alloys. Furthermore, the effect of Al and Mg addition on the Sn/Ag3Sn eutectic were also investigated. It was found that the addition of both Al and Mg successfully refined the Cu6Sn5in Sn-3wt%Ag-5wt%Cu solder alloy. In addition, Al suppresses the formation of Ag3Sn in the Sn/Ag3Sn eutectic; while Mg promotes the formation of fine Sn/Ag3Sn eutectic microstructure. The refinement of Cu6Sn5is believed to be due to heterogeneous nucleation by Al and Mg rich intermetallic particles respectively. Effect of Al and Mg addition on the undercooling of the Sn/Ag3Sn eutectic was found to be similar, both reducing undercooling effectively at a low addition rate of 0.025wt%. The addition of Al and Mg have mixed effect on the nucleation temperature of Cu6Sn5. It is found that the nucleation temperature of Cu6Sn5is increased with 0.025wt% Al and 0.1wt% Mg addition to the unmodified alloy, while the nucleation temperature slowly decreases again as the trace element addition rate increases.
The Interaction of Sn-Ga Alloys and Au Coated Cu Substrates
Authors: Liu Shi Qian , Qu Dong Dong , McDonald Stuart D. , Nogita Kazuhiro
Published: June 2018

Ga and Ga-based alloys appear to be promising materials for low temperature soldering in microelectronics. This research involved an analysis of the joint interfaces that resulted from reactions between a eutectic Ga-Sn alloy and Au coated Cu substrates at both room temperature and 100°C. At both temperatures the intermetallic CuGa2 accounted for the majority of the interfacial microstructure. This study has shown the possibility of using eutectic Ga-Sn alloys in low temperature soldering applications, as well as the advantages of Synchrotron XFM techniques in characterising trace element distributions in solder joints.
Solidification Behavior of Sn Cu Based Peritectic Alloys: A Short Review
Authors: Said Rita Mohd , Mohd Salleh Mohd Arif Anuar , Saud Norainiza , Ramli Mohd Izrul Izwan , Sandu Andrei Victor
Published: June 2018

Microstructure evolution that exhibit from the reaction of Sn Cu pritectic alloys become an interesting phenomenon that need to be explored since the properties of the alloys depend on their microstructures. Due to less understanding on the solidification behavior on peritectic alloys, extensive research are made on this type of alloys to gain more information regarding on the microstructure formation. This paper reviews the mechanisms on peritectic solidification on Sn Cu based peritectic alloys. The changed in peritectic microstructure due to external source such as direct current (DC) field, ultrasonic field and isothermal time are discuss respectively through this paper. The focus is made on peritectic solidification of Sn Cu based alloy since it has a promising potential for high temperature lead-free solder application.
Corrosion of Sn-Zn-Bi Lead Free Solder in KOH Electrolyte
Authors: Ervina Efzan M.N. , Kamaneeya R.
Published: June 2018

The corrosion of Sn-Zn-Bi lead free solder in 6M KOH electrolyte was conducted. The study was done using 3 different KOH concentrations (3M, 6M and 9M) and the immersion technique was used to produce corrosion. Due to the nature of immersion, the solder material was prepared by punching it into small billets size after melting it homogenously on a commercial hotplate. The immersion was set to 7, 14 and 21 days. After the specific days have fulfilled the sample billets were removed and tested. The corrosion of this solder was measured using various method such as graphical analysis, surface roughness, corrosion penetration rate (CPR) and optical microscope. In this research, it was found out that the sample billets taken from 6M concentration compared to 3M and 9M showed more corrosion this was supported by the outcome of the test. The 6M believed to provide best corrosion on the solder billets because of its high ionic conductivity value.
Effect of Phosphorus and Nickel on Electrochemical Migration of Sn-3Ag-0.7Cu Solder Paste in Simulated Body Fluid
Authors: Othman Norinsan Kamil , Salleh Emee Marina , Sarveswaran C. , Che Ani Fakhrozi
Published: June 2018

Electrochemical migration (ECM) behaviour of Sn-3Ag-0.7Cu and Sn-3Ag-0.7Cu-0.03P-0.005Ni solder alloys were investigated using simulated body fluid (SBF) solution. In electronic devices, ECM phenomenon potentially leads to incompetence or failure of the whole devices. According to water drop test (WDT), mean-time-to-failure (MTTF) of commercially used Sn-3Ag-0.7Cu solder alloy was prolonged with addition of phosphorus (P) and nickel (Ni) as alloying elements. According to microstructure of each solder paste alloy which was observed using field emission scanning electron microscope (FESEM), dendrite structure in Sn-3Ag-0.7Cu-0.03P-0.005 Ni solder was lesser than in plain the Sn-3Ag-0.7Cu. This phenomenon suggested that presence of P and Ni retarded the growth of dendritic thus improved its corrosion resistance. Therefore, Sn-3Ag-0.7Cu-0.03P-0.005Ni possessed a good corrosion resistance in SBF medium.
Liquid Phase Sintering of (Ti,W)C-Ni-Co-Cr Cermets: Microstructure and Abrasive Wear Behavior
Authors: Iparraguirre I. , Lozada L. , Ibarreta F. , Martinez R. , Sanchez J.M.
Published: June 2018

TiC-WC-(Ni,Co,Cr) cermets are potential candidates for the substitution of straight cemented carbides in certain wear applications. This work analyses the effect of Ti/W and Co/Ni ratios on the microstructure and abrasion resistance of this type of cermets. From a microstructural point of view, cermets in the (Ti,W)C-(Ni,Co,Cr) pseudo-binary region show uncontrolled (Ti,W)C grain growth and a high degree of contiguity of the carbide phase. A microstructural refinement is observed as the Ti/W ratio decreases, especially when WC precipitation occurs. Abrasion resistance in these materials is dominated by hardness.
Structure and Properties of Biomorphous Al/C/TiO/TiC Composite Materials Reinforced with Charcoals Coated in ALD and the Sol-Gel Process
Authors: Tański Tomasz , Krzemiński Łukasz
Published: June 2018

In this framework, an investigation of biomorphous composite materials was performed. The application of a natural reinforcement allows to obtain biomorphous composite materials. Pine wood samples were subjected to the pyrolysis process in order to obtain carbon char. The samples were subjected to Atomic Layer Deposition and the sol-gel coating process in order to obtain a titanium oxide and titanium carbide coating, respectively. Ti-gel carbon char samples were subjected to ceramisation. Pure carbon char coated with TiO and TiC was infiltrated with an Al alloy. The investigations of the obtained composite materials were performed using light microscopy, transmission and scanning electron microscopy for microstructure determination. Raman spectroscopy and X-ray analysis were performed, along with hardness and tribological tests. Crystallites were detected after infiltration of the porous samples with an Al alloy, which were up to several microns in size, depending on the selected coating. As a result of the investigation on coating samples, a significantly smaller presence of Al carbides was found. An increase of hardness and wear resistance of biomorphous composite materials containing the carbides phase was confirmed. The TiO2coating prevents the occurrence of a reaction during the infiltration process and the formation of Al carbides.
Effect of Heat Treatment Combined with High Pressure Torsion Process on Microstructure and Hardness of AlMg5Si2Mn Alloy
Authors: Snopiński Przemysław , Tański Tomasz
Published: June 2018

This study evaluated the effect of a heat treatment on the potential application of AlMg5Si2Mn die casting alloy as a substitute for wrought aluminium alloy products. The proposed heat treatment was intended to increase the workability of the AlMg5Si2Mn alloy, which is typically not malleable due to the presence of interconnected brittle phases. By disintegrating interconnected eutectic Mg2Si phases into fragmented particles and dissolving Mg-rich phases the workability was increased. Subsequently, heat treated samples were subjected to high-pressure torsion process. The microstructure of the heat treated and deformed samples were characterized using light and electron microscope. Hardness measurements were used to investigate the influence the number of HPT revolutions on mechanical properties.
Ligation of the CD44 Glycoform HCELL on Culture-Expanded Human Monocyte-Derived Dendritic Cells Programs Transendothelial Migration
Authors: Videira Paula A. , Silva Mariana , Martin Kyle C. , Sackstein Robert
Published: June 2018

The success of dendritic cell (DC)–based immunotherapeutics critically hinges on the capacity of the vascularly administered cells to enter tissues. Transendothelial migration (TEM) is dictated by an ordered cascade of receptor/ligand interactions. In this study, we examined the key molecular effectors of TEM of human monocyte-derived DCs (mo-DCs) generated by clinically relevant methods: CD14 selection (CD14-S) and plastic adherence selection (PA-S). Without chemokine input, CD14-S cells undergo greater TEM than PA-S cells over TNF-α–stimulated HUVECs. TEM of CD14-S mo-DCs is E-selectin/very late Ag-4 (VLA-4) dependent, and engagement of E-selectin ligands activates VLA-4 on CD14-S mo-DCs but not on PA-S mo-DCs. E-selectin binding glycoforms of P-selectin glycoprotein ligand-1 (PSGL-1) (i.e., cutaneous lymphocyte Ag [CLA]) and CD44 (i.e., hematopoietic cell E-selectin/L-selectin ligand [HCELL]) are both expressed on CD14-S mo-DCs, but only CLA is expressed on PA-S mo-DCs. To elucidate the effect of CD44 or PSGL-1 engagement, mo-DCs were pretreated with their ligands. Ligation of CD44 on CD14-S mo-DCs triggers VLA-4 activation and TEM, whereas PSGL-1 ligation does not. HCELL expression on CD14-S mo-DC can be enforced by cell surface exofucosylation, yielding increased TEM in vitro and enhanced extravasation into bone marrow in vivo. These findings highlight structural and functional pleiotropism of CD44 in priming TEM of mo-DCs and suggest that strategies to enforce HCELL expression may boost TEM of systemically administered CD14-S mo-DCs.
Gli Odonati della Riserva Naturale “Macchia di Gattaceca e Macchia del Barco” (Lazio) (Odonata)
Authors: Brocchieri Davide , Castelluccio Paolo , Crucitti Pierangelo
Published: June 2018

Nel contributo viene presentata la checklist commentata delle specie di Odonata censite negli anni tra il 2009 e il 2013 nella Riserva Naturale “Macchia di Gattaceca e Macchia del Barco”, settore del cosiddetto “arcipelago mentanese cornicolano” a nord-est dell’area urbana di Roma. Il numero delle specie censite ammonta a 26, 10 Zygoptera e 16 anisoptera, su un totale di 57 specie segnalate nel Lazio. Per ciascuna specie sono riportati dati fenologici relativi al periodo di volo e ad altri aspetti significativi del ciclo biologico.
Factors that Impede and Promote the Persistence of Black Women in Athletic Training Programs
Authors: Siple Bonnie J. , Hopson Rodney K. , Sobehart Helen C. , Turocy Paula Sammarone
Published: June 2018

Context:

Black women are dramatically underrepresented in the health care profession of athletic training. The research identifies impeding barriers such as racism, sexism, lack of support, and unpreparedness to the successful college completion of ethnically diverse students. However, there are black women who have successfully overcome those impeding barriers to become athletic trainers (ATs). Mentoring is one factor that has been identified as supportive to the retention of ethnically diverse college students.

Objective:

The purpose of this qualitative study was to identify impeding barriers and promoting factors affecting the retention and credentialing of black women ATs.

Design:

Qualitative.

Setting:

Education.

Patients or Other Participants:

Ten certified ATs who self-identify as black women and matriculated through athletic training programs over the last 4 decades.

Main Outcome Measure(s):

The perceived factors that impede or promote successful college retention and attainment of the Board of Certification credential of black women athletic training students.

Results:

There are barriers that impede and factors that promote the successful matriculation of black women athletic training students. Impeding barriers include a lack of support, sexism, and racism. Factors that promote include personal characteristics; experience with white culture; faculty, preceptor, and peer support; and the clinical education experience.

Conclusions:

Recognizing the factors that impede or promote the academic persistence of black women in athletic training programs allows athletic training educators and preceptors to improve the experiences of black women enrolled in those programs and potentially increase their participation and advancement in the athletic training profession.
Системы Никишина на звездных множествах: алгебраические свойства и слабая асимптотика соответствующих совместно ортогональных многочленов
Authors: Lopez-García Abey , Mina-Díaz Erwin
Published: June 2018

Исследуются многочлены $Q_n(z)$, $n=0,1,…$, совместно ортогональные относительно системы Никишина $p\geqslant 1 $ мер с компактными носителями на звездном множестве, образованном $p+1$ лучами $S_+:=z\in \mathbb{C}\colon z^{p+1}\geqslant 0 \}$. Доказывается, что эта система Никишина нормальна и многочлены удовлетворяют Библиография: 16 названий.
Метод задачи Римана-Гильберта в применении к системе Никишина
Authors: Lopez Lagomasino Guillermo , Van Assche Walter
Published: June 2018

Описывается асимптотика совместно ортогональных многочленов типа I для системы Никишина второго порядка, заданной на паре непересекающихся отрезков. С использованием задачи Римана-Гильберта для совместно ортогональных многочленов и метода наискорейшего спуска для осциллирующих задач Римана-Гильберта находится асимптотика во всех областях комплексной плоскости, существенных для рассматриваемой задачи.
Библиография: 38 названий.
"Математический сборник" в контексте отечественной истории: к 150-летию создания журнала
Authors: Demidov Sergei Sergeevich , Petrova Svetlana Sergeevna , Tokareva Tat'yana Aleksandrovna
Published: June 2018

В 1866 г. был основан один из старейших в мире математических журналов "Математический сборник". Рассмотрена история журнала в контексте истории России. Анализируется его роль в развитии отечественной математики.
Библиография: 15 названий.
Une observation épizootologique de la fièvre aphteuse en France
Authors: Tamotsu Ito
Published: June 2018

On peut décomposer en trois parties la courbe de l’épizootie de la fièvre aphteuse, en France, de mai 1951 en novembre 1952.

Ces trois courbes suivent à la loi de Laplace-Gauss si l’on prend l’échelle logarithmique pour représenter la courbe de fréquence.
Comentários ao caso Artavia Murillo e outros vs. Costa Rica (“Fertilização in vitro”) e seus possíveis reflexos no ordenamento jurídico brasileiro
Authors: Sales Echaiz Espinoza Danielle , Campos Christopoulos Basile Georges
Published: June 2018

O artigo tem como objetivo analisar a sentença da Corte Interamericana de Direitos Humanos (Corte IDH) no caso Artavia Murillo e outros vs. Costa Rica (“Fertilização in vitro”), tecendo comentários aos principais argumentos lançados pela Corte IDH para determinar a interpretação do direito à vida, especialmente quando este se encontra em conflito com outros direitos humanos previstos na Convenção Interamericana de Direitos Humanos. Pretende ainda refletir sobre os efeitos que tal interpretação poderá ter sobre o ordenamento jurídico brasileiro, no qual a questão do início da proteção do direito fundamental à vida permanece em debate.
Making Time in Stanley Kubrick’s Barry Lyndon
Authors: Pramaggiore Maria
Published: June 2018

Considered by critics to be Stanley Kubrick's masterpiece, Barry Lyndon has suffered from scholarly and popular neglect. Maria Pramaggiore argues that one key reason that this film remains unappreciated, even by Kubrick aficionados, is that its transnational and intermedial contexts have not been fully explored. Taking a novel approach, she looks at the film from a transnational perspective -- as a foreign production shot in Ireland and an adaptation of a British novel by an American director about an Irish subject. Pramaggiore argues that, in Barry Lyndon, Kubrick develops his richest philosophical mediation on cinema's capacity to mediate the real and foregrounds film's relationship to other technologies of visuality, including painting, photography, and digital media.

By combining extensive research into the film's source novel, production and reception with systematic textual analysis and an engagement with several key issues in contemporary academic debate, this work promises not only to make a huge impact in the field of Kubrick studies, but also in 1970s filmmaking, cultural history and transnational film practice.
Toxicity of four metals and their mixtures to Pseudomonas fluorescens: An assessment using fixed ratio ray design
Authors: Nweke Christian Okechukwu , UMEH SARAH IGBOKWUBIRI , OHALE VIVIAN KELECHI
Published: June 2018

The toxicities of binary (Ni(II) + Co(II) and Zn(II) + Cd(II)), ternary (Zn(II) + Cd(II) + Ni(II) and Ni(II) + Co(II) + Cd(II)) and quaternary (Ni(II) + Co(II) + Zn(II) + Cd(II)) mixtures of metal ions to Pseudomonas fluorescens were assessed by using inhibition of dehydrogenase activity as an endpoint. Uniform design concentration ratio (UDCR) and equieffect concentration ratio (EECR) mixtures were designed to evaluate the combined toxicities of these heavy metal ions. All the dose-response relationships of the UDCR and EECR mixtures and the individual metals could be described by logistic function. Toxicities predicted by concentration addition (CA) and independent action (IA) models were compared with the observed toxicities. The CA and IA models predicted similar toxicities of the binary and Zn(II) + Cd(II) + Ni(II) ternary mixtures. Generally, Zn(II) + Cd(II) + Ni(II) ternary mixtures were synergistic while Ni(II) + Co(II) + Cd(II) ternary mixtures were antagonistic. The equieffect and quaternary mixtures were generally synergistic. Synergistic, antagonistic and additive effects of the mixtures are possible from the viewpoint of these analyses.
Trace elements in an adjacent channel of an anthropized area: a case study of Baixada Santista, Southeastern Brazil
Authors: Salaroli Alexandre Barbosa , Kim Bianca Sung Mi , Angeli José Lourenço Friedmann , Figueira Rubens Cesar Lopes
Published: June 2018

In recent decades, due to intensive industrialization, the Baixada Santista has undergone an intense process of environmental degradation. The metals are toxic and persistent in varying concentrations and oxidation states and may be incorporated in sediments and biota. Thus, understanding the importance of this contamination is necessary for coastal planning. This study provides a basis for understanding the levels of metal and As contamination in the Bertioga Channel (SP). The levels of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sc, V and Zn in superficial sediment samples were determined by ICP-OES. The degree of sediment contamination was evaluated according to the sediment quality standards set by the Canadian environmental agency (ISQG and PEL) and by statistical tests. All values were below PEL, and most of the sample values were below ISQG, except for As, Cu and Pb. From a cluster analysis, it was possible to differentiate eastern and western parts of the channel due to their distinct hydrodynamic patterns. Furthermore, it was possible to separate the trace elements by geochemical behavior, in which Cu, Pb and Zn were linked to a small anthropogenic contribution. Thus, this study detected small anthropogenic contributions from an adjacent channel of an anthropized area, but most of the results were linked to natural geochemical processes.
Cloud heterogeneity on cloud and aerosol above cloud properties retrieved from simulated total and polarized reflectances
Authors: Cornet Céline , C.-Labonnote Laurent , Waquet Fabien , Szczap Frédéric , Deaconu Lucia , Parol Frédéric , Vanbauce Claudine , Thieuleux François , Riédi Jérôme
Published: June 2018

Abstract. Simulations of total and polarized cloud reflectance angular signatures such
as the ones measured by the multi-angular and polarized radiometer
POLDER3/PARASOL are used to evaluate cloud heterogeneity effects on cloud
parameter retrievals. Effects on optical thickness, albedo, effective radius
and variance of the cloud droplet size distribution and aerosol parameters
above cloud are analyzed. Three different clouds that have the same mean optical
thicknesses were generated: the first with a flat top, the second
with a bumpy top and the last with a fractional cloud cover. At small
scale (50 m), for oblique solar incidence, the illumination effects lead to
higher total but also polarized reflectances. The polarized reflectances even
reach values that cannot be predicted by the 1-D homogeneous cloud assumption.
At the POLDER scale (7 km × 7 km), the angular signature is modified by a
combination of the plane–parallel bias and the shadowing and illumination
effects. In order to quantify effects of cloud heterogeneity on operational
products, we ran the POLDER operational algorithms on the simulated
reflectances to retrieve the cloud optical thickness and albedo. Results show
that the cloud optical thickness is greatly affected: biases can reach up to
−70, −50 or +40 % for backward, nadir and forward viewing
directions, respectively. Concerning the albedo of the cloudy scenes, the
errors are smaller, between −4.7 % for solar incidence angle of
20∘ and up to about +8 % for solar incidence angle of
60∘. We also tested the heterogeneity effects on new algorithms
that allow retrieving cloud droplet size distribution and cloud top pressures
and also aerosol above clouds. Contrary to the bi-spectral method, the
retrieved cloud droplet size parameters are not significantly affected by the
cloud heterogeneity, which proves to be a great advantage of using polarized
measurements. However, the cloud top pressure obtained from molecular
scattering in the forward direction can be biased up to about 60 hPa (around
550 m). Concerning the aerosol optical thickness (AOT) above cloud, the
results are different depending on the available angular information. Above
the fractional cloud, when only side scattering angles between 100
and 130∘ are available, the AOT is underestimated because of the
plane–parallel bias. However, for solar zenith angle of 60∘
it is overestimated because the polarized reflectances are increased in
forward directions.
BOREAS – a new MAX-DOAS profile retrieval algorithm for aerosols and trace gases
Authors: Bösch Tim , Rozanov Vladimir , Richter Andreas , Peters Enno , Rozanov Alexei , Wittrock Folkard , Merlaud Alexis , Lampel Johannes , Schmitt Stefan , de Haij Marijn , Berkhout Stijn , Henzing Bas , Apituley Arnoud , den Hoed Mirjam , Vonk Jan , Tiefengraber Martin , Müller Moritz , Burrows John Philip
Published: June 2018

Abstract. We present a new MAX-DOAS proﬁling algorithm for aerosols and trace gases, BOREAS, which utilizes an iterative solution method including Tikhonov regularization and the optimal estimation technique. Performance tests are separated into two parts. First, we address the general sensitivity of the retrieval on the example of synthetic data calculated with the radiative transfer model SCIATRAN. In a second part of the study, we demonstrate BOREAS proﬁling accuracy by validating results with the help of ancillary measurements carried out during the CINDI-2 campaign in Cabauw, the Netherlands in 2016. The synthetic sensitivity tests indicate, that the regularization between measurement and a priori constraints is insufﬁcient when knowledge of the true state of the atmosphere is poor. We demonstrate a priori pre-scaling and extensive regularization tests as a tool for the optimization of retrieved proﬁles. The comparison of retrieval results with in situ, ceilometer, NO2 LIDAR, sonde and long path DOAS measurements during the CINDI-2 campaign always shows high correlations with coefﬁcients greater than 0.79. The largest differences can be found in the morning hours, when the planetary boundary layer is not yet fully developed and the concentration of trace gases and aerosol, as a result of a low night-time boundary layer having formed, is focused in a shallow, surface near layer.
Dynamics Geomagnetic Storm on 7–10 September 2015 as Observed by TWINS and Simulated by CIMI
Authors: Perez Joseph D. , Edmond James , Hill Shannon , Xu Hanyun , Buzulukova Natalia , Fok Mei-Ching , Goldstein Jerry , McComas David J. , Valek Phil
Published: June 2018

Abstract. For the first time, direct comparisons of the equatorial ion pressure and pitch angle anisotropy observed by TWINS and simulated by CIMI are presented. The TWINS ENA images are from a 4-day period, 7–10 September 2015. The simulations use both the empirical Weimer 2K and the self-consistent RCM electric potentials. There are two moderate storms in succession during this period. In most cases, we find that the general features of the ring current in the inner magnetosphere obtained from the observations and the simulations are similar. Nevertheless, we do see consistent indications of enhanced electric and magnetic shielding in the TWINS observations. The simulated pressure peaks are often inside the observed peaks and more toward dusk than the measured values. There are also cases in which the measured equatorial ion pressure shows multiple peaks that are not seen in the simulations. This occurs during a period of intense AE index, suggesting time and spatially dependent injections from the plasma sheet that are not included in these simulations. The simulations consistently show regions of parallel anisotropy spanning the night side between approximately 6 and 8 RE whereas the parallel anisotropy is seen in the observations only during the main phase of the first storm. This may indicate stronger electric and magnetic shielding than is present in the simulations. The evidence form the unique global view provided by the TWIN observations strongly suggests that there are features in the ring current pressure distributions that can be best explained by enhanced electric and magnetic shielding and/or spatially-localized, short-duration injections..
Quantification of lignin oxidation products as vegetation biomarkers in speleothems and cave drip water
Authors: Heidke Inken , Scholz Denis , Hoffmann Thorsten
Published: June 2018

Abstract. Here we present a sensitive method to analyse lignin oxidation products (LOPs) in speleothems and cave drip water to provide a new tool for paleo vegetation reconstruction. Speleothems are valuable climate archives. However, compared to other terrestrial climate archives, such as lake sediments, speleothems contain very little organic matter. Therefore, very few studies on organic biomarkers in speleothems are available. Our new sensitive method allows to use LOPs as vegetation biomarkers in speleothems. Our method consists of acid digestion of the speleothem sample followed by solid phase extraction (SPE) of the organic matter. The extracted polymeric lignin is degraded in a microwave assisted alkaline CuO oxidation step to yield monomeric LOPs. The LOPs are extracted via SPE and finally analysed via ultrahigh-performance liquid chromatography (UHPLC) coupled to electrospray ionisation (ESI) and high-resolution orbitrap mass spectrometry (HRMS). The method was applied to stalagmite samples with a sample size of 3–5 g and cave drip water samples with a sample size of 100–200 mL from the Herbstlabyrinth-Advent-Cave in Germany. In addition, fresh plant samples, soil water and powdered lignin samples were analysed for comparison. The concentration of the sum of eight LOPs (Σ8) was in the range of 20–84 ng g−1 for the stalagmite samples and 230–440 ng L−1 for the cave drip water samples. The limits of quantification for the individual LOPs ranged from 0.3–8.2 ng per sample. Our method represents a new and powerful analytical tool for paleo vegetation studies and has great potential to identify the pathways of lignin incorporation into speleothems.
Model constraints on the anthropogenic carbon budget of the Arctic Ocean
Authors: Terhaar Jens , Orr James C. , Gehlen Marion , Ethé Christian , Bopp Laurent
Published: June 2018

Abstract. The Arctic Ocean is projected to experience not only amplified climate change but also amplified ocean acidification. Modeling future acidification depends on our ability to simulate baseline conditions and changes over the industrial era. Such centennial-scale changes require a global model to account for exchange between the Arctic and surrounding regions. Yet the coarse resolution of typical global models may poorly resolve that exchange as well as critical features of Arctic Ocean circulation. Here we assess how simulations of Arctic Ocean storage of anthropogenic carbon (Cant), the main driver of open- ocean acidification, differ when moving from coarse to eddy admitting resolution in a global ocean circulation-biogeochemistry model (NEMO-PISCES). The Arctic's regional storage of Cant is enhanced as model resolution increases. While the coarse- resolution model configuration ORCA2 (2°) stores 2.0 Pg C in the Arctic Ocean between 1765 and 2005, the eddy-admitting versions ORCA05 and ORCA025 (1/2° and 1/4°) store 2.4 and 2.6 Pg C. That result from ORCA025 falls within the uncertainty range from a previous data-based Cant storage estimate (2.5 to 3.3 Pg C). Yet those limits may each need to be reduced by about 10 % because data-based Cant concentrations in deep waters remain at ∼ 6 μmol kg−1, while they should be almost negligible by analogy to the near-zero observed CFC-12 concentrations from which they are calculated. Across the three resolutions, there was roughly three times as much anthropogenic carbon that entered the Arctic Ocean through lateral transport than via the flux of CO2 across the air-sea interface. Wider comparison to nine earth system models that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) reveals much larger diversity of stored anthropogenic carbon and lateral transport. Only the CMIP5 models with higher lateral transport obtain Cant inventories that are close to the data-based estimates. Increasing resolution also enhances acidification, e.g., with greater shoaling of the Arctic's average depth of the aragonite saturation horizon during 1960–2012, from 50 m in ORCA2 to 210 m in ORCA025. To assess the potential to further refine modeled estimates of the Arctic Ocean's Cant storage and acidification, sensitivity tests that adjust model parameters are needed given that century-scale global ocean biogeochemical simulations still cannot be run routinely at high resolution.
Principle components of thermal regimes in mountain river networks
Authors: Isaak Daniel J. , Luce Charles H. , Chandler Gwynne L. , Horan Dona L. , Wollrab Sherry P.
Published: June 2018

Abstract. Description of thermal regimes in flowing waters is key to understanding physical processes, enhancing predictive abilities, and improving bioassessments. Spatially and temporally sparse datasets, especially in logistically challenging mountain environments, have limited studies on thermal regimes but inexpensive sensors coupled with crowd-sourced data collection efforts provide efficient means of developing large datasets for robust analyses. Here, thermal regimes are assessed using annual monitoring records spanning a five-year period (2011–2015) at 226 sites across several contiguous montane river networks in the northwestern U.S. Regimes were summarized with 28 metrics and principle components analysis (PCA) was used to determine those metrics which best explained thermal variation on a reduced set of orthogonal axes. Four principle components (PC) accounted for 93.4 % of the variation in the temperature metrics, with the first PC (49 % of variance) associated with metrics that represented magnitude and variability and the second PC (29 % of variance) associated with metrics representing the length and intensity of the winter season. Another variant of PCA, T-mode analysis, was applied to daily temperature values and revealed two distinct phases of spatial variance – a homogeneous phase during winter when daily temperatures at all sites were
Flooded by jargon: how the interpretation of water-related terms differs between hydrology experts and the general audience
Authors: Venhuizen Gemma J. , Hut Rolf , Albers Casper , Stoof Cathelijne R. , Smeets Ionica
Published: June 2018

Abstract. Communication about hydrology-induced hazards is important, in order to keep the impact of floods, droughts et cetera as low as possible. However, sometimes the boundary between specialized and non-specialized language can be vague. Therefore, a close scrutiny of the use of hydrological vocabulary by both experts and laypeople is necessary. In this study, we compare the expert and lay definitions of 12 common water-related terms and 10 water-related pictures to see where misunderstandings might arise both in text and pictures. Our primary objective is to analyze the degree of agreement between experts and laypeople in their definition of the used terms. In this way, we hope to contribute to improving the communication between these groups in the future. Our study was based on a survey completed by 34 experts and 119 laypeople. Especially concerning the definition of water-related words there are some profound differences between experts and laypeople: words like river and river basin turn out to have a thoroughly different interpretation between the two groups. Concerning the pictures, there is much more agreement between the groups.
A stochastic event-based approach for flood estimation in
catchments with mixed rainfall/snowmelt flood regimes
Authors: Filipova Valeriya , Lawrence Deborah , Skaugen Thomas
Published: June 2018

Abstract. The estimation of extreme floods is associated with high uncertainty, in part due to the limited length of streamflow records. Traditionally, flood frequency analysis or event-based model using a single design storm have been applied. We propose here an alternative, stochastic event-based modelling approach. The stochastic PQRUT method involves Monte Carlo procedure to simulate different combinations of initial conditions, rainfall and snowmelt, from which a distribution of flood peaks can be constructed. The stochastic PQRUT was applied for 20 small and medium-sized catchments in Norway and the results show good fit to the observations. A sensitivity analysis of the method indicates that the soil saturation level is less important than the rainfall input and the parameters of the PQRUT model for flood peaks with return periods higher than 100 years, and that excluding the snow routine can change the seasonality of the flood peaks. Estimates for the 100- and 1000-year return level based on the stochastic PQRUT model are compared with results for a) statistical frequency analysis, and b) a standard implementation of the event-based PQRUT method. The differences between the estimates can be up to 200 % for some catchments, which highlights the uncertainty in these methods.
The evolution of mode-2 internal solitary waves modulated by background shear currents
Authors: Zhang Peiwen , Xu Zhenhua , Li Qun , Yin Baoshu , Hou Yijun , Liu Antony K.
Published: June 2018

Abstract. The evolution of mode-2 internal solitary waves (ISWs) modulated
by background shear currents was investigated numerically. The mode-2 ISW was
generated by the “lock-release” method, and the background shear current
was initialized after the mode-2 ISW became stable. Five sets of experiments
were conducted to assess the sensitivity of the modulation process to the
direction, polarity, magnitude, shear layer thickness and offset extent of
the background shear current. Three distinctly different shear-induced waves
were identified as a forward-propagating long wave, oscillating tail and
amplitude-modulated wave packet in the presence of a shear current. The
amplitudes of the forward-propagating long wave and the amplitude-modulated
wave packet are proportional to the magnitude of the shear but inversely
proportional to the thickness of the shear layer, as well as the energy loss
of the mode-2 ISW during modulation. The oscillating tail and
amplitude-modulated wave packet show symmetric variation when the background
shear current is offset upward or downward, while the forward-propagating
long wave was insensitive to it. For comparison, one control experiment was
configured according to the observations of Shroyer et al. (2010); in the
first 30 periods, ∼ 36 % of total energy was lost at an average
rate of 9 W m−1 in the presence of the shear current; it would deplete
the energy of initial mode-2 ISWs in ∼ 4.5 h, corresponding to a
propagation distance of ∼ 5 km, which is consistent with in situ data.
Electromagnetic characteristics of ENSO
Authors: Petereit Johannes , Saynisch Jan , Irrgang Christopher , Weber Tobias , Thomas Maik
Published: June 2018

Abstract. The motion of electrically conducting sea water through Earth's magnetic
field induces secondary electromagnetic fields. Due to its periodicity, the
oceanic tidally induced magnetic field is easily distinguishable in magnetic
field measurements and therefore detectable. These tidally induced signatures
in the electromagnetic fields are also sensitive to changes in oceanic
temperature and salinity distributions. We investigate the impact of oceanic
heat and salinity changes related to the El Niño–Southern Oscillation (ENSO)
on oceanic tidally induced magnetic fields. Synthetic hydrographic
data containing characteristic ENSO dynamics have been derived from a coupled
ocean–atmosphere simulation covering a period of 50 years. The corresponding
tidally induced magnetic signals have been calculated with the 3-D induction
solver x3dg. By means of the Oceanic Niño Index (ONI), based on sea surface
temperature anomalies, and a corresponding Magnetic Niño Index (MaNI),
based on anomalies in the oceanic tidally induced magnetic field at sea
level, we demonstrate that evidence of developing ENSO events can be found in
the oceanic magnetic fields statistically 4 months earlier than in sea
surface temperatures. The analysis of the spatio-temporal progression of the
oceanic magnetic field anomalies offers a deeper understanding on the
underlying oceanic processes and is used to test and validate the initial
findings.
Samambaias e licófitas do Parque Estadual Turístico do Alto Ribeira, Iporanga, SP, Brasil
Authors: Fregolente Faracco Mazziero Frederico , Labiak Paulo Henrique , Paciencia Mateus Luis Barradas
Published: June 2018

O Parque Estadual Turístico do Alto Ribeira é um importante remanescente de Floresta Atlântica, pois abriga grande biodiversidade e, junto com outras Unidades de Conservação em seu entorno, constitui um dos maiores maciços desta formação no país. O Parque está localizado na porção sudeste do Estado de São Paulo e é predominantemente constituído por Floresta Atlântica, a qual é responsávelpor abrigar um importante número de espécies de samambaias e licófitas, onde estas plantas consttuem um elemento conspícuo da flora no subosque. Embora muitos levantamentos florísticos tenhamsido publicados para áreas de Floresta Atlântica do Estado de São Paulo, poucos fornecem meios paraa identificação das espécies. O objetivo principal no presente estudo é apresentar uma chave para a identificação de 251 espécies de samambaias e licófitas encontradas no Parque. Além disso, foram feitastambém comparações entre as espécies encontradas e taxa próximos, além de dados sobre os ambientes de ocorrência das espécies na área de estudo.
The Community–Based Poverty Reduction Projects (CPRP), Poverty Reduction and Development in Yobe State Nigeria: A Pilot Study Report
Authors: Waziri Hassana Ibrahim , Nwanegbo Chukwuemeka Jaja
Published: June 2018

This paper examines the impact of the Community-Based Poverty Reduction Project (CPRP) in alleviating poverty in selected benefiting communities in Yobe State. Purposive and simple random sampling was used to select the area of study and respondents. Questionnaires, Focus Group Discussion and Key Informants Interview were also used to collect data. The data was presented by the use of simple percentage and frequency tables, graphs and charts. Data was analysed through the use of ANOVA. The discourse, guided by the Basic Needs Theory found out that even though the concept for which the CPRP was adopted has been achieved, e.g. community participation and provision of 838 micro-projects in the whole of Yobe State, the micro-projects or basic needs infrastructure implemented are not adequate and wide-spread enough to reduce poverty in concrete terms. It however reduced the stress of people in accessing some basic needs e.g. water supply in some communities. The paper recommends that to effectively achieve poverty reduction, there should be sustained commitment of funding and maintenance of projects by respective stakeholders for holistic and widespread approach to poverty reduction in Yobe State. Nonetheless, this paper maintains that the CPRP poverty reduction intervention is a viable tool for the provision of basic needs infrastructure in rural communities to set the path for development of Yobe State.
Today’s Knowledge Economy and Firm Growth: A Study of Small to Medium Enterprises in the Manufacturing Sector of Zimbabwe
Authors: Manuere Faitira , Mabvure Tendai Joseph , Sifile Obert , Viriri Piason
Published: June 2018

Small to Medium Enterprises (SMEs) in Zimbabwe are characterized by high failure rates. This failure rate has been attributed to poor leadership, poor funding and lack of technology. The contribution of knowledge management to SMEs growth has received very little attention from researchers in Zimbabwe. Hence this study makes an effort to investigate the relationship between knowledge management models and SMEs growth. Data were collected from 32 SMEs owners in the Makonde District of Zimbabwe. Pearson’s product moment was used as a tool for data analysis. The independent variables are knowledge creation, knowledge acquisition, knowledge storage and knowledge dissemination. The dependent variable is SMEs growth. The findings show that knowledge management positively correlates to SMEs growth. To that end the study recommends that effective models of knowledge management must be used to boost the growth of SMEs in Zimbabwe.
APLICAÇÃO DO MRP PARA O PCP DE UMA EMPRESA DE PRÉ-MOLDADOS DE CONCRETO
Authors: Costa Marco Túlio Domingues , Komesu Acácio Hiroyuki , Barcelos Bráulio Frances
Published: June 2018

O planejamento em uma empresa tornou-se peça chave para poder se produzir devido aos aspectos mercadológicos que estão mais competitivos e propícios para corte de gastos e custos. Portanto, o propósito do projeto foi aplicar os conceitos de Planejamento e Controle da Produção (PCP) utilizando a ferramenta MRP para auxiliar a identificação da necessidade de matérias para a produção, de modo a auxiliar a tomada de decisão para as etapas do processo produtivo. A metodologia utilizada foi à pesquisa ação desenvolvida em uma empresa do setor de Pré Moldados de Concreto localizado na cidade de Itabira - MG. Como resultados houve um equilíbrio da demanda de produção com a demanda de matérias, determinando a quantidade necessária de matéria prima para a realização da produção, evitando as interrupções no processo por falta de material pelo uso do MRP. Por fim, o estudo auxiliou a empresa a ter um ganho competitivo melhorando o processo produtivo, determinando a quantidade utilizada de matéria prima, diminuição de desperdícios e os prazos para aquisição, de modo a atender os prazos estabelecidos e melhorar a confiabilidade da organização. Palavras-chave: MRP, Planejamento e Controle da Produção, Pré-Moldados de Concreto
PROPOSTA DE MELHORIA DE LAYOUT PARA UMA OFICINA DE CAMINHÕES POR MEIO DA APLICAÇÃO DA METODOLOGIA PSL
Authors: Santos Tiago Silva dos , Silva Estela Vitoria da Silva e , Monteiro Amanda Sousa , Rocha Nathalia De Souza , Alves Lucas Fialho
Published: June 2018

A escolha do layout pode afetar a eficiência e os custos de forma geral de um empreendimento. O objetivo deste artigo é apresentar uma aplicação do modelo de planejamento sistemático de layout (PSL), conhecido como SLP (Systematic Layout Planning), em uma oficina de caminhões no sudeste do estado do Pará, no município de Marabá. Logo, através da aplicação da metodologia três novos layouts foram elaborados e, o que atendeu em aspectos gerais às necessidades foi projetado, gerando melhorias como: eliminação do maior fluxo de deslocamento entre o almoxarifado e a oficina, maior integração entre os setores, aumento da qualidade final do serviço pretado, melhoria das condições ergonômicas dos operadores - com o intuito de proporcionar a segurança adequada para o trabalhador e satisfação em exercer sua função no trabalho - e a redução do lead time nos setores.
INDUSTRIAL BURNERS TESTING AND COMBUSTION EFFICIENCY ANALYSIS
Authors: Pimenta J. , De Lima L.C. , Duarte J.B.F. , Macedo R. M.
Published: June 2018

This paper describes experimental procedures and techniques adopted for combustion analysis during the testing of burners for industrial applications.

The tests were carried out in the Combustion Technology Laboratory (NTC) of the University of Fortaleza. The NTC facilities are composed basically of experimental testing hall, a monitoring room, a chromatography laboratory and a modeling and simulation studies room.

In the lab testing hall, is installed a test bench composed basically of the following parts : a combustion chamber with nominal thermal capacity of 1.000.000 kcal/h, two fully instrumented gas and air supply sections, a gas analyzer for emissions measurement, a panel for monitoring of water supply to combustion chamber coil, a cooling tower for heat delivery of combustion chamber. A data acquisition and control system is available with all the hardware tools for monitoring of the combustion process.

With all the acquired measurements of temperature, flow rate, pressures, emissions, etc., the First Law energy balance approach was used in order to evaluate the combustion efficiency of two different burners with 378.000 and 403.200 kcal/h nominal heat power. Analysis of preliminary results allows representing the burners efficiency according to different air and fuel operating conditions.

The experimental data obtained are also compared with simulation results from the modeling of the combustion process, presented in another article linked with this work, where a discussion of such comparison is made.

Future studies will be dedicated to the development of improved efficiency combustion systems for industrial and commercial applications.
A SIMPLIFIED OXIDATION MODEL FOR TWO-PHASE FLOW IN POROUS MEDIA
Authors: Da Mota J. C. , De Souza A. J. , Marchesin D. , Teixeira P. W.
Published: June 2018

This paper describes a simplified mathematical model for thermal recovery by oxidation for flow of oxygen and oil in porous media. Some neglected important physical effects include gravity, compressibility and heat loss to the rock formation, but heat longitudinal conduction and capillary pressure difference between the phases are considered. The mathematical model is obtained from the mass balance equations for air and oil, energy balance and Darcy's law applied to each phase. Based on this model some typical features in low temperature oxidation concerning the wave structure are captured. Numerical simulations showing saturations and temperature profiles are reported.