bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and application of an automated extraction algorithm for fetal magnetocardiography – normal data and arrhythmia detection
Authors: Stingl Krunoslav , Paulsen Henrike , Weiss Magdalene , Preissl Hubert , Abele Harald , Goelz Rangmar , Wacker-Gussmann Annette
Published: July 2013

Introduction: Current standard methods of monitoring fetal heart function are mainly based on echocardiography, which provides indirect information (through mechanical assessment) of the fetal heart rhythm. Fetal magnetocardiography (fMCG) allows a reliable quantification of the temporal structure of fetal heart signals. However, its application in clinical studies is difficult because extracting the fetal heart signal for most current applications requires user intervention. To overcome this limitation, we developed a completely automated extraction algorithm.

Patients and methods: The fMCG recordings were acquired using a 156-channel biomagnetic system. To perform an automated analysis, a combination of orthogonal projection and independent component analysis was used. fMCG recordings from 69 healthy uncomplicated singleton pregnancies with normally developing fetuses were included in the study.

Results: The normal values achieved by the automated algorithm were comparable to previously published data. The majority of the cardiac time intervals were positively correlated with gestational age (GA). The ST segment, T wave and QT interval did not show any correlation.

Conclusions: The automated detection of fetal heart signals was possible beginning at a GA of 19 weeks. This automated analysis of fMCG recordings might be an objective and easily applicable approach for clinicians to analyze fetal heart signals.
Is pathologic confirmation of placental abruption more reliable in cases due to chronic etiologies compared with acute etiologies?
Authors: Heller Debra S. , Keane-Tarchichi Megan , Varshney Shalini
Published: July 2013

Background: Pathology laboratories often receive requests for confirmation of abruption; however, pathologically, abruption can only be confirmed by the presence of adherent blood clot on the maternal surface that is indenting the underlying placental parenchyma.

Design: We evaluated whether abruptions due to more chronic underlying medical conditions are more likely to have a retained indenting retroplacental clot that is detectable by the pathologist than abruptions due to acute etiologies. This was a retrospective review from January 1995 to June 2012 of cases with a clinical and/or pathologic diagnosis of abruption. Data were analyzed utilizing Fisher’s exact test.

Results: Ninety-six cases had sufficient available information for analysis. There was a significant association between pathologic identification of abruption and chronic risk factors (P=0.03). Twenty-five percent of cases with acute risk factors and 60% of cases with chronic risk factors had abruption confirmed at pathologic evaluation (P=0.12).

Conclusion: Pathologically confirmable abruption is associated with chronic risk factors. There was a trend towards chronic risk factors leading to greater likelihood of pathologic confirmation of abruption than acute risk factors, but it did not reach statistical significance.
Dietary glycotoxins affect scavenger receptor expression and the hormonal profile of female rats
Authors: Chatzigeorgiou Antonios , Kandaraki Eleni , Piperi Christina , Livadas Sarantis , Papavassiliou Athanasios G , Koutsilieris Michael , Papalois Apostolos , Diamanti-Kandarakis Evanthia
Published: July 2013

The levels of advanced glycation end products (AGEs) are increased under conditions of impaired glucose metabolism and/or oxidative stress, promoting insulin resistance and other endocrine abnormalities. AGEs play a major role in the pathogenesis of several diseases such as diabetes, atherosclerosis, polycystic ovary syndrome and Alzheimer's disease, contributing to progressive ageing. Receptor-based clearance of AGEs by the receptor for AGE (RAGE) and/or the macrophage scavenger receptor A (SR-A) is considered as a main factor for the regulation of the concentration of AGEs under these conditions. This study aimed to investigate the expression of RAGE (AGER) and SR-A (MSR1) under high/low-dietary AGE conditionsin vivoand their potential contribution to the metabolic and sex hormonal profile of female rats. Female Wistar rats were fed a low-AGE or high-AGE diet for 3 months. Serum samples were collected at baseline and at the completion of the 3-month period for the measurements of metabolic and hormonal parameters. Peripheral blood mononuclear cells (PBMCs) were isolated for the determination of the expression of RAGE and SR-A. The high-AGE diet-fed rats exhibited increased glucose, insulin and testosterone levels as well as decreased oestradiol and progesterone levels compared with the low-AGE diet-fed ones, thus indicating a metabolic and hormonal dysregulation attributed to high-AGE dietary exposure. The expression of RAGE was significantly down-regulated in the PBMCs of the high-AGE diet-fed rats (P=0.041), and it was correlated negatively with insulin and testosterone levels and positively with progesterone levels. The expression of SR-A was also decreased in the high-AGE diet-fed rats to marginal significance. Decreased monocytic expression of scavenger receptors such as RAGE and SR-A may result in a higher deposition of AGEs in peripheral endocrine tissues, thus promoting endocrine-related abnormalities and diseases.
Which firms are the most innovative? The importance of multinationals and exporters in Portugal
Authors: Silva Armando , Afonso Oscar , Africano Ana
Published: July 2013

We test the Global Engagement (GE) hypothesis according to which the most globally engaged firms, whether multinationals or exporters, are the most innovative. The test is applied to data from 4815 Portuguese firms for the period 2002–2004 based on the 4thCommunity Innovation Survey for Portugal. We estimated several Knowledge Production Functions, assuming that knowledge outputs result from the combination of certain knowledge inputs with the flow of ideas coming from the existing stock of knowledge. We found that the more internationally engaged firms create more knowledge output than their domestic counterparts; indeed, the more globalised firms apply more inputs and have the opportunity to use a larger stock of knowledge. Nevertheless, the relative perceived advantage of the more internationally exposed firms is also the result of their globalised nature, and is not directly connected with knowledge inputs or information flows.
Characterization of Nanostructured Electrodeposited NiCo Samples by use of Electron Backscatter Diffraction (EBSD)
Authors: Bastos Alice , Raabe Dierk , Zaefferer Stefan , Schuh Christopher
Published: July 2013

A Cobalt-20wt.% Nickel polycrystal produced by electrodeposition has been investigated in planar and cross sections using a high resolution scanning electron microscope. The local texture, grain size, amount of phase and grain boundaries, were characterized by Electron Backscatter Diffraction (EBSD). The average grain size perpendicular to the grain growth direction was 400 nm. Parallel to it, a pronounced bimodal grain structure was observed with grains reaching more than 10 μm and grains of approximately 800 nm diameter.
Incidência da cardiopatia chagásica em 15.000 necrópsias consecutivas e sua associação com os «megas»
Authors: Barbosa A. J. A. , Pittella J. E. H. , Tafuri W. L.
Published: July 2013

Os AA. estudaram, a incidência da cardiopatia chagásica em 15.000 necrópsias consecutivas e sua associação com os megas. Em 875 cardiopatias chagásicas houve 145 casos de megas, ou seja, 16,56%, com predominância do sexo masculino. No branco houve maior incidência (55) de megas do que no mulato (53) e no negro (31) dentre 858 cardiopatias chagásicas. Em 848 cardiopatias chagásicas, 85,78% eram de indivíduos que faleceram entre 21 e 60 anos. O maior número de cardiopatias (120 ou 14,14%) e de "megas'' (21 ou 15,78%) foi encontrado nos indivíduos entre 36 a 40 anos. Os nossos resultados mostram uma incidência diferente da associação cardiopatia-mega, em comparação da observada em outras regiões do País e em outros países da América do Sul.
Erisipelóide de Baker-Rosenbach
Authors: Macedo Aureo Guimarães de
Published: July 2013

O erisipelóide de Baker-Rosenbach, embora assinalado no Brasil há 23, anos, por Sebastião Sampaio, seguido de nove casos estudados em 1951 por Lacaz e Ancona Lopes, não tem sido motivo de publicações posteriores. O A. teve ocasião de estudar seis casos, senão que três foram motivo de trabalho anterior e foram observados em 1953. Os três restantes, um de 1965 e dois de 1967, são aqui relatados. Assinala o A. a ubiquidade do germe, o Erysipelotrix rhusiopathiae e a variedade de condições em que o homem pode infectar-se, especialmente no exercício de determinadas profissões, o que dá à doença, caráter típico de doença profissional. São os operários de fábricas de botões ou em geral os que lidam com ossos, especialmente de porco ou carneiro, os açougueiros, magarefes, salsicheiros etc. São particularmente vulneráveis os que tratam com produtos do mar, pescadores, mercadores de siris, camarões, crustáceos, peixes em geral, pela facilidade com que se podem ferir e adquirir a infecção por picada ocasional. A doença atinge numerosos animais domésticos ou não, com formas clínicas bem definidas no porco (erisipela dos porcos), no carneiro (poliartrite dos carneiros), em animais de corte e de tração, em aves domésticas ou de rapina, ratos e camundongos, além de outros numerosos roedores. Moscas hematófagas e outros insetos têm sido encontrados infectados. Nunca é demais frisar que os produtos do mar são grande fonte de infecção humana. No homem, tem a dcença em geral, caráter benigno e localizado (erisipelóide), podendo em certas circunstâncias assumir característica septicêmica como no porco, produzir endocardite, como no carneiro além de outras formas clínicas e complicações. São resumidos no texto os três casos anteriormente apresentados e bem descritos os três inéditos, que têm história clínica e evolução típicas de erisipelóide. Tratando-se de doença com características tipicamente profissional, há que ser considerada como tal, com respeito às dispensas de serviço ou outras implicações previdenciárias, razão porque mais avulta a necessidade de seu diagnóstico exato e bem documentado, tanto mais que determinadas formas clínicas podem levar à morte. O uso indiscriminado de antibióticos, antes de chegar-se ao diagnóstico, é hábito que deve ser combatido a fim de que se possa melhor avaliar da incidência, em nosso meio.
Obesidade e asma: associação ou epifenômeno?
Authors: Andrade Larissa Smiljanic , Araújo Andrea Cristina T. B. , Cauduro Tatiana Moraes , Watanabe Letícia Aki , Castro Ana Paula B. M. , Jacob Cristina Miuki A. , Pastorino Antonio Carlos
Published: July 2013

OBJETIVO: Avaliar a associação entre obesidade e asma pela comparação entre idade, gênero, classificação inicial e controle da asma, valores de volume expiratório forçado no primeiro segundo (VEF1) e fluxo expiratório forçado entre 25 e 75% (FEF25-75%) basais com os índices de massa corpórea (IMC) em adolescentes asmáticos. MÉTODOS: Estudo transversal envolvendo 120 pacientes (1,9 masculino:1 feminino) asmáticos com mediana de idade de 14,1 anos (9 a 20,1 anos), classificados quanto ao controle e gravidade da asma e avaliados pela espirometria utilizando VEF1 e FEF25-75% basais. Esses dados foram descritos pela frequência, médias e desvio padrão ou medianas e variação, sendo analisados pelos testes de ANOVA, teste t não pareado, teste exato de Fisher, Kruskal-Wallis e pela correlação de Pearson, considerando-se significante p<0,05. RESULTADOS: Não houve diferença entre os gêneros em relação à classificação inicial da asma e ao nível de controle. Receberam classificação inicial persistente 91,7% (100 casos), sendo que 106 casos (88,3%) encontravam-se parcial ou totalmente controlados. Não houve diferença estatística entre os pacientes controlados e os demais em relação ao IMC. Não foram encontradas correlações significantes entre zIMC e VEF1 e entre zIMC e FEV25-75%, analisando-se todos os pacientes e apenas pacientes com sobrepeso ou obesos. CONCLUSÕES: Neste estudo, não foi encontrada correlação significante entre sobrepeso/obesidade e asma, utilizando-se parâmetros clínicos, antropométricos e espirométricos.
Desvios posturais em escolares de uma cidade do Sul do Brasil
Authors: Bueno Rita de Cássia de S. , Rech Ricardo Rodrigo
Published: July 2013

OBJETIVO: Verificar a prevalência de desvios posturais do tronco (hiperlordose lombar, hipercifose dorsal e escoliose) em escolares de oito a 15 anos da rede municipal de ensino de Caxias do Sul, Rio Grande do Sul, Brasil. MÉTODOS: Avaliaram-se 864 estudantes, por meio de um estudo transversal. As variáveis estudadas foram análise postural do tronco por inspeção visual; índice de massa corpórea (peso e altura); peso da mochila (balança digital); a forma como os escolares transportavam o material escolar (questionário); sexo e idade. Foi utilizada estatística descritiva e bivariada, representada por razão de prevalência e intervalo de confiança. RESULTADOS: As prevalências de desvios posturais observadas foram de 16,6% para hipercifose dorsal, 27,9% para hiperlordose lombar e 33,2% para atitude escoliótica. A idade de oito a 12 anos apresentou-se como fator de risco para hiperlordose lombar. Os escolares pertencentes a tal faixa etária demonstraram 3,41 vezes mais chance de ter o desfecho em questão. Para a hipercifose dorsal, a mesma idade mostrou-se como fator de proteção. Os estudantes 8-12 anos tiveram 52% menos chances de desenvolver hipercifose dorsal. O sexo feminino apresentou 47% menos chances de ter hipercifose dorsal em relação ao masculino. A atitude escoliótica não apresentou associação significativa com as variáveis independentes. CONCLUSÕES: Os achados confirmam a necessidade de intervenções por parte dos profissionais de saúde e educação, buscando corrigir hábitos inadequados de postura corporal, os quais, com o tempo, podem se agravar e causar danos irreversíveis.
Obesidade na criança e no adolescente: quantas calorias a mais são responsáveis pelo excedente de peso?
Authors: Pereira Helen Rose C. , Bobbio Tatiana Godoy , Antonio Maria Ângela R. G. M. , Barros Filho Antônio de Azevedo
Published: July 2013

OBJETIVO: Revisar os principais artigos referentes ao tema desequilíbrio energético e obesidade, a fim de quantificar o excedente energético diário associado ao ganho de peso em crianças e adolescentes. FONTES DE DADOS: Artigos publicados nos últimos dez anos, indexados nas bases de dados eletrônicas Medline (Pubmed) e SciELO-Br. Na base de dados Medline, utilizou-se o descritor "energy gap", termo que descreve os valores energéticos associados às modificações no peso corporal em indivíduos ou populações. Na base de dados SciELO-Br, utilizaram-se os descritores "obesidade", "metabolismo energético", "balanço energético" e "desequilíbrio energético", devido ao fato de não terem sido encontrados artigos nacionais que discutissem o assunto "energy gap". SÍNTESE DOS DADOS: Na população infantil, quatro estudos foram realizados e indicam que crianças e adolescentes estão gradualmente ganhando peso devido a um pequeno, mas persistente, balanço energético positivo diário, 70 a 160kcal acima do total calórico adequado para o crescimento. Os valores encontrados sugerem que pequenas modificações nos hábitos diários de alimentação e de atividade física seriam suficientes para evitar futuros ganhos de peso nessa população. CONCLUSÕES: O ganho gradual de peso pode ser explicado por pequena média diária de balanço energético positivo, de 70 a 160kcal acima do total calórico adequado para o crescimento. O incentivo às pequenas modificações nos hábitos alimentares e de atividades físicas que promovam a redução de 160kcal diárias pode ser uma prática acessível, a fim de barrar o ganho de peso nessa população.
Design of railway bridges considering life-cycle assessment
Authors: Thiebault Vincent , Du Guangli , Karoumi Raid
Published: July 2013

The world is currently confronted with the challenge of preventing environmental degradation and resource depletion. To compare the environmental performance of two railway bridge designs, an Excel-based model was developed with implementing a simplified quantitative life-cycle assessment. The model covers the entire life cycle of the bridge, from raw material extraction to construction materials recycling and disposal. Various assumptions are made for selecting the relevant emissions and environmental impacts. A streamlined approach is applied to compare the environmental burden throughout the life cycle of the Banafjäl Railway Bridge. The bridge is a simply supported composite structure carrying one railway track. Two track alternatives are investigated: ballasted track and fixed track. The results show that the environmental impacts of the fixed track alternative are lower than those of the ballasted track alternative. From a sustainable development perspective, it appears that fixed track has a significant advantage as the overall environmental impact is reduced by up to 77%. The raw material phase is found to be decisive in the life cycle of both alternatives. The frequency of track replacement is identified as a key environmental parameter, because the extra environmental burden of traffic delay during bridge closure nearly overwhelmed the other life-cycle stages.
Effect of Non‐Surgical Periodontal Therapy on Serum Ferritin Levels: An Interventional Study
Authors: Chakraborty Souvik , Tewari Shikha , Sharma Rajinder Kumar , Narula Satish Chander
Published: July 2013

Background: Ferritin, an acute‐phase reactant, has been found to be elevated in many chronic inflammation‐related diseases. The aim of the present study is to investigate differences in concentrations of serum ferritin in patients with and without periodontal disease before and after non‐surgical periodontal therapy and correlate these values with clinical variables associated with periodontal disease.

Methods: Forty‐two individuals were included in this study, 20 with chronic periodontitis (CP) and 22 classified as periodontally healthy. Serum ferritin concentrations, hemoglobin levels, and periodontal parameters (probing depth [PD], clinical attachment level, gingival index, bleeding on probing, and plaque index) were recorded at baseline and 3 months after non‐surgical periodontal therapy.

Results: Patients with CP showed higher concentrations of serum ferritin than periodontally healthy controls (P <0.01). After adjustment for confounders, a positive and significant correlation was observed between serum ferritin levels and the number of sites with PD ≥6 mm at baseline (P <0.01). Regression analyses revealed association between deep pockets and serum ferritin levels at baseline (R2 = 0.823). Significant reductions in serum ferritin levels were observed at the 3‐month assessment after periodontal treatment (P <0.01), and the post‐treatment serum ferritin values were comparable to those of controls (P >0.05). Furthermore, the post‐treatment degree of change in the serum ferritin level was positively and significantly associated with improvement in PD (R2 = 0.213, P <0.05).

Conclusion: Serum ferritin levels are raised in patients with CP and decrease to control levels post‐treatment.
Comparative Evaluation of Photoablative Efficacy of Erbium: Yttrium‐Aluminium‐Garnet and Diode Laser for the Treatment of Gingival Hyperpigmentation. A Randomized Split‐Mouth Clinical Trial
Authors: Giannelli Marco , Formigli Lucia , Bani Daniele
Published: July 2013

Background: The use of lasers in periodontology is a matter of debate, mainly because of the lack of consensual therapeutic protocols. In this randomized, split‐mouth trial, the clinical efficacy of two different photoablative dental lasers, erbium:yttrium‐aluminum‐garnet (Er:YAG) and diode, for the treatment of gingival hyperpigmentation is compared.

Methods: Twenty‐one patients requiring treatment for mild‐to‐severe gingival hyperpigmentation were enrolled. Maxillary or mandibular left or right quadrants were randomly subjected to photoablative deepithelialization with either Er:YAG or diode laser. Masked clinical assessments of each laser quadrant were made at admission and days 7, 30, and 180 postoperatively by an independent observer. Histologic examination was performed before and soon after treatment and 6 months after irradiation. Patients also compiled a subjective evaluation questionnaire.

Results: Both diode and Er:YAG lasers gave excellent results in gingival hyperpigmentation. However, Er:YAG laser induced deeper gingival tissue injury than diode laser, as judged by bleeding at surgery, delayed healing, and histopathologic analysis. The use of diode laser showed additional advantages compared to Er:YAG in terms of less postoperative discomfort and pain.

Conclusions: This study highlights the efficacy of diode laser for photoablative deepithelialization of hyperpigmented gingiva. It is suggested that this laser can represent an effective and safe therapeutic option for gingival photoablation.
Estimating the GIS-based soil loss and sediment delivery ratio to the sea for four major basins in South Korea
Authors: Lee S. E. , Kang S. H.
Published: July 2013

This paper describes a sediment delivery ratio (SDR) using the Geographic Information System (GIS)-based Revised Universal Soil Loss Equation (RUSLE), to calculate the soil loss and sediment rating curve (SRC) basis of measured data in the six basins of Four Rivers, South Korea. The data set for calculating SDR was prepared during 3 years from 2008 to 2010. Mean soil loss in the six basins of Four Rivers was 515–869 t km−2 yr−1 and mean specific sediment yield (SSY) was 20–208 t km−2 yr−1 with basin size. The SDR ranged from 0.03 to 0.33 in the six rivers. Most sediment flows in the monsoon period from June to September (mean Max.: >97%; mean Min.: >84%), but SDR is lower than those of similar continental river basins. This is due to environmental factors, for example rainfall characteristics and associated run-off, soil characteristics and cultivated patterns with increasing basin size. This research provides the first application of SDR based on the observed field data in South Korea.
A normalized regression based regional model for generating flows at ungauged basins
Authors: Blagojević Borislava , Plavšić Jasna
Published: July 2013

Revision of existing methodologies for generating monthly-flow series at ungauged basins based on multivariate nonlinear correlation has led to a simple two-parameter model. While the existing methodology used hydrological, meteorological and geomorphologic input data, the proposed model requires hydrological and geomorphologic input data only. The proposed methodology requires formation of separate pools of donor catchments for model parameter estimates. The proposed two-parameter model and improvement in the sphere of homogeneous region identification were verified using 195 runoff data sets from hydrologic stations in Serbia in the 1961–2005 period, divided into three non-overlapping 15-year periods. Nash-Sutcliffe's model efficiency coefficient (NSE) was used to assess the: (1) quality of proposed model with identified model parameters; (2) quality of a nonlinear multivariate equation for standard normal variables estimation with identified model parameters; (3) quality of proposed model with model parameter estimates. Generated time-series statistics and nonlinear multivariate equation quality are also evaluated. Five model calibration and validation results are shown. Generated flow series variation coefficient is the best replicated statistics with relative absolute error less than 10%.
Enhanced thermophilic fermentative hydrogen production from cassava stillage by chemical pretreatments
Authors: Wang Wen , Luo Gang , Xie Li , Zhou Qi
Published: July 2013

Acid and alkaline pretreatments for enhanced hydrogen production from cassava stillage were investigated in the present study. The result showed that acid pretreatment was suitable for enhancement of soluble carbohydrate while alkaline pretreatment stimulated more soluble total organic carbon production from cassava stillage. Acid pretreatment thereby has higher capacity to promote hydrogen production compared with alkaline pretreatment. Effects of pretreatment temperature, time and acid concentration on hydrogen production were also revealed by response surface methodology. The results showed that the increase of all factors increased the soluble carbohydrate production, whereas hydrogen production was inhibited when the factors exceeded their optimal values. The optimal conditions for hydrogen production were pretreatment temperature 89.5 °C, concentration 1.4% and time 69 min for the highest hydrogen production of 434 mL, 67% higher than raw cassava stillage.
Comparing the impact of time displaced and biased precipitation estimates for online updated urban runoff models
Authors: Borup Morten , Grum Morten , Mikkelsen Peter Steen
Published: July 2013

When an online runoff model is updated from system measurements, the requirements of the precipitation input change. Using rain gauge data as precipitation input there will be a displacement between the time when the rain hits the gauge and the time where the rain hits the actual catchment, due to the time it takes for the rain cell to travel from the rain gauge to the catchment. Since this time displacement is not present for system measurements the data assimilation scheme might already have updated the model to include the impact from the particular rain cell when the rain data is forced upon the model, which therefore will end up including the same rain twice in the model run. This paper compares forecast accuracy of updated models when using time displaced rain input to that of rain input with constant biases. This is done using a simple time–area model and historic rain series that are either displaced in time or affected with a bias. The results show that for a 10 minute forecast, time displacements of 5 and 10 minutes compare to biases of 60 and 100%, respectively, independent of the catchments time of concentration.
Impact of rainfall temporal resolution on urban water quality modelling performance and uncertainties
Authors: Manz Bastian Johann , Rodríguez Juan Pablo , Maksimović Čedo , McIntyre Neil
Published: July 2013

A key control on the response of an urban drainage model is how well the observed rainfall records represent the real rainfall variability. Particularly in urban catchments with fast response flow regimes, the selection of temporal resolution in rainfall data collection is critical. Furthermore, the impact of the rainfall variability on the model response is amplified for water quality estimates, as uncertainty in rainfall intensity affects both the rainfall-runoff and pollutant wash-off sub-models, thus compounding uncertainties. A modelling study was designed to investigate the impact of altering rainfall temporal resolution on the magnitude and behaviour of uncertainties associated with the hydrological modelling compared with water quality modelling. The case study was an 85-ha combined sewer sub-catchment in Bogotá (Colombia). Water quality estimates showed greater sensitivity to the inter-event variability in rainfall hyetograph characteristics than to changes in the rainfall input temporal resolution. Overall, uncertainties from the water quality model were two- to five-fold those of the hydrological model. However, owing to the intrinsic scarcity of observations in urban water quality modelling, total model output uncertainties, especially from the water quality model, were too large to make recommendations for particular model structures or parameter values with respect to rainfall temporal resolution.
Impact of hydraulic loading rate and media type on removal of bulk organic matter and nitrogen from primary effluent in a laboratory-scale soil aquifer treatment system
Authors: Abel Chol D. T. , Sharma Saroj K. , Buçpapaj Ervin , Kennedy Maria D.
Published: July 2013

The effect of hydraulic loading rate (HLR) and media type on the removal of bulk organic matter and nitrogen from primary effluent during soil aquifer treatment was investigated by conducting laboratory-scale soil column studies. Two soil columns packed with silica sand were operated at HLRs of 0.625 and 1.25 m/d, while a third column was packed with dune filtering material and operated at HLR of 1.25 m/d. Bulk organic matter was effectively removed by 47.5 ± 1.2% and 45.1 ± 1.2% in silica sand columns operated at 0.625 and 1.25 m/d, respectively and 57.3 ± 7.6% in dune filtering material column operated at 1.25 m/d. Ammonium-nitrogen reduction of 74.5 ± 18.0% was achieved at 0.625 m/d compared to 39.1 ± 4.3% at 1.25 m/d in silica sand columns, whereas 49.2 ± 5.2% ammonium-nitrogen reduction was attained at 1.25 m/d in the dune filtering material column. Ammonium-nitrogen reduction in the first 3 m was assumed to be dominated by nitrification process evidenced by corresponding increase in nitrate. Part of the ammonium-nitrogen was adsorbed onto the media, which was observed at higher rates between 3 and 5 m in silica sand column operated at HLR of 0.625 m/d and dune filtering material column operated at 1.25 m/d compared to 1.25 m/d silica.
Performance of denitrifying microbial fuel cell subjected to variation in pH, COD concentration and external resistance
Authors: Li Jin-Tao , Zhang Shao-Hui , Hua Yu-Mei
Published: July 2013

The effects of pH, chemical oxygen demand (COD) concentration and external resistance on denitrifying microbial fuel cell were evaluated in terms of electricity generation characteristics and pollutant removal performance. The results showed that anodic influent with weakly alkaline or neutral pH and cathodic influent with weakly acidic pH favored pollutant removal and electricity generation. The suitable influent pH of the anode and cathode were found to be 7.5–8.0 and 6.0–6.5, respectively. In the presence of sufficient nitrate in the cathode, higher influent COD concentration led to more electricity generation and greater pollutant removal rates. With an anodic influent pH of 8.0 and a cathodic influent pH of 6.0, an influent COD concentration of 400 mg/L was deemed to be appropriate. Low external resistance favored nitrate and COD removal. The results suggest that operation of denitrifying microbial fuel cell at a lower external resistance would be desirable for pollutant removal but not electricity generation.
Impacts of climate change on rainfall extremes and urban drainage systems: a review
Authors: Arnbjerg-Nielsen K. , Willems P. , Olsson J. , Beecham S. , Pathirana A. , Bülow Gregersen I. , Madsen H. , Nguyen V.-T.-V.
Published: July 2013

A review is made of current methods for assessing future changes in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic-induced climate change. The review concludes that in spite of significant advances there are still many limitations in our understanding of how to describe precipitation patterns in a changing climate in order to design and operate urban drainage infrastructure. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing these with other objectives will become ever more important to keep our cities habitable into the future.
Fabrication of Nanoparticles by Electric Discharge Plasma in Liquid
Authors: Yatsu S. , Takahashi H. , Sasaki H. , Sakaguchi N. , Ohkubo K. , Muramoto T. , Watanabe S.
Published: July 2013

The electric plasma discharge method involves the application of a voltage between a cathode and anode in a conductive electrolytic solution to create a discharge plasma at the cathode. When certain material is used as the cathode, small droplets are emitted with the plasma discharge, and the melted droplets are rapidly cooled in the solution to form nanoscale particles of the material. In this work, nanoparticles of Al, Au, Si, and various alloys of between 100 nm and less than 10 nm in size were produced and characterized. Characterization of Si nanoparticles is especially important because their use in lithium batteries greatly influences battery performance. It was found by high resolution electron microscopy and microstructural surface analysis that oxidation layers of a few nm in thickness were formed on the surface of the Si nanoparticles.
Structure Investigation of Ball Milled Composite Powder Based on AlSi5Cu2 Alloy Chips Modified by Sic Particles
Authors: Śusniak M. , Karwan-Baczewska J. , Dutkiewicz J. , Actis Grande M. , Rosso M.
Published: July 2013

The paper is focused on the processing of aluminum alloy chips using powder metallurgy. Chips obtained from recycled AlSi5Cu2 alloy were ball milled with the addition of silicon carbide powder with an average size of 2μm. Mechanical alloying process was employed to obtain homogeneous composite powder. The effect of processing time (0 - 40h) on the homogeneity of the system was evaluated, as well as a detailed study of the microstructure of AlSi5Cu2 aluminum chips and SiC particles during MA was carried out. Addition of silicon carbide (10, 20wt%) to recycled aluminium chips and application of MA lead to fragmentation of the homogeneous composite powder down to particle size of about 3μm and spheroidization. The addition of hard SiC particles caused reinforcement and reduced the milling time. Higher content of silicon carbide and longer processing time allowed to obtain AlSi5Cu2/SiC powders with microhardness ∽500HV0,025. The results of MA were investigated with SEM, EDS, LOM, XRD and showed that relatively homogeneous distribution of SiC reinforcements in the matrix as well as grain refinement of aluminum solid solution down to 50nm can be obtained after 40h of processing.
Composite Zones Produced in Iron Castings by In-Situ Synthesis of Tic Carbides
Authors: Olejnik E. , Górny M. , Tokarski T. , Grabowska B. , Kmita A. , Sikora G.
Published: July 2013

The study discusses a method of producing composite zones at the edge of castings made of ferritic-pearlitic ductile iron. Composite zones were produced in castings made of ferritic-pearlitic ductile iron at the casting edge. The reinforcing phase for the composite zone was TiC carbide, obtained by in-situ synthesis of substrates introduced into the mould in the form of compacts. The composition of the substrates of the reaction of the TiC synthesis was next enriched with an Fe filler added in an amount of 10 and 50 wt. % to investigate the possibility of changing the hardness of the composite zone. The addition of filler changed the surface fraction and the average size of TiC precipitates. In the case of the 50 wt. % addition, a tenfold reduction in the dimensions of the carbides was obtained. This increased their surface fraction relative to the compact composition containing only 10 wt. % of the filler. Changes in mechanical properties were analysed within the zone area by the measurement of hardness HV. The study showed a gradual decrease of the zone hardness in function of the amount of the filler added. This trend was also true as regards the composite zone in castings, where a significant refinement and increased surface content of the TiC precipitates was observed.
Microstructure and Mechanical Properties of Mg-2.5%Tb-0.78%Sm Alloy After Ecap and Ageing
Authors: Bryła K. , Dutkiewicz J. , Rokhlin L.L. , Litynska-Dobrzynska L. , Mroczka K. , Kurtyka P.
Published: July 2013

The influence of ageing and Equal Channel Angular Pressing (ECAP) on the microstructure and mechanical properties of Mg-2.5%Tb-0.78%Sm alloy has been examined. The microhardness changes during ageing at 200ºC show a slight increase. The aged microstructure at maximum hardness contains Mg12(Tb,Sm) - metastable β’ phase of size about 2-10 nm as dispersed precipitates. The orientation relationship between β’ phase and the matrix was found as follows:(0001)Mg || (1¯10)β′, [21¯10]Mg || [116]β′. The ECAP passes were performed by two procedures: “I” - four passes at 350ºC; “II” - one pass at 370ºC, second pass at 340ºC and third pass at 310ºC. The grain size was reduced about 200 times as a results of ECAP process according “I” and “II” procedure. The grain refinement by ECAP improves significantly the compression yield strength and hardness. The Hall-Petch relationship was confirmed basing on microhardness measurements and the grain size after ECAP. The Mg24(Tb,Sm)5 and Mg41(Sm,Tb)5 particles smaller than 150 nm are located mainly at grain and subgrain boundaries and they prevent grain growth during ECAP processing. The microstructure evolution during ECAP can be described as dynamic recovery and continuous and discontinuous dynamic recrystallization.
Shear Strength and Dsc Analysis of High-Temperature Solders
Authors: Koleňák R. , Martinkovič M. , Koleňáková M.
Published: July 2013

The work is devoted to the study of shear strength of soldered joints fabricated by use of high-temperature solders of types Bi-11Ag, Au-20Sn, Sn-5Sb, Zn-4Al, Pb-5Sn, and Pb-10Sn. The shear strength was determined on metallic substrates made of Cu, Ni, and Ag. The strength of joints fabricated by use of flux and that of joints fabricated by use of ultrasonic activation without flux was compared. The obtained results have shown that in case of soldering by use of ultrasound (UT), higher shear strength of soldered joints was achieved with most solders. The highest shear strength by use of UT was achieved with an Au-20Sn joint fabricated on copper, namely up to 195 MPa. The lowest average values were achieved with Pb-based solders (Pb-5Sn and Pb-10Sn). The shear strength values of these solders used on Cu substrate varied from 24 to 27 MPa. DSC analysis was performed to determine the melting interval of lead-free solders.
The Microstructures and Hardness Analysis of a New Hypereutectoid Mn-Cr-Mo-V Steel
Authors: Dabrowski R. , Rozniata E. , Dziurka R.
Published: July 2013

The results of a microstructure and hardness investigations of a new hypereutectoid Mn-Cr-Mo-V steel, imitating by its chemical composition tool steels, are presented in the paper. The microstructure as well hardness changes, caused by austenitising and tempering temperatures were assessed, for samples quenched and sub-quenched in liquid nitrogen, directly after the quenching treatment. Additionally, the influence of the tempering temperature on the volume fraction of the retained austenite was estimated. New hypereutectoid steel, after an appropriate heat treatment obtained the relevant hardness of the tools used in the cold and hot working proces.

It was indicated that the steel hardness increases with the increases of the austenitising temperature. At 800ºC the hardness of the quenched samples were equal 895HV, and for the sub-quenched samples 937HV. The maximum hardness, after tempering (746HV), was found at a temperature of 520ºC.

It will be possible, in future, to apply this obtained investigation results in designing chemical compositions and microstructures of the new hypereutectoid alloyed steels of properties required by their users.
Analysis of the Influence of Drawing Process Parameters on the Mechanical Properties of Trip-Structure Steel Wires
Authors: Wiewiórowska S.
Published: July 2013

The research concerned with wire drawing processes of medium-carbon steel with TRIP effect classified into group of AHSS (Advanced High Strength Steel) steels, which are the multiphase steels offering a unique combination of high strength and ductility, has been shown in the work. Such combination is achieved through the transformation of retained austenite to martensite in deformation process called TRIP effect (Transformation Induced Plasticity).

Studies reported in the literature relate mainly to the research on the car body sheet rolling and heat treatment processes, which does not allow the results of this research to be referred to the analysis of drawing processes.

Therefore, the need has arisen for developing and conducting comprehensive studies on the process of drawing TRIP steels wires and identification the new application areas for these materials.
Measurements of two-phase flow patterns and local void fraction in vertical rectangular minichannel
Authors: Kaniowski Robert , Poniewski Mieczysław
Published: July 2013

Technology advancements entail a necessity to remove huge amounts of heat produced by today’s electronic devices based on highly integrated circuits, major generators of heat. Heat transfer to boiling liquid flowing through narrow minichannels is a modern solution to the problem of heat transfer enhancement. The study was conducted for FC-72 boiling in a rectangular, vertical and asymmetrically heated minichannel that had depths of 0.5-1.5 mm, a width of 20 mm and a length of 360 mm. The heat flux increased and decreased within the range of 58.3-132.0 kWm−2, the absolute pressure ranged from 0.116 to 0.184 MPa and the mass flux was 185-1139.2 kgm−2s−1. The boiling process took place on a flat vertical heating surface made of Haynes-230 0.1 mm thick acid-proof rolled plate with the surface roughness of 121 μm.
Modeling of heat and mass transfer during thermal decomposition of a single solid fuel particle
Authors: Wardach-Święcicka Izabela , Kardaś Dariusz
Published: July 2013

The aim of this work was to investigate the heat and mass transfer during thermal decomposition of a single solid fuel particle. The problem regards the pyrolysis process which occurs in the absence of oxygen in the first stage of fuel oxidation. Moreover, the mass transfer during heating of the solid fuels is the basic phenomenon in the pyrolysis-derived alternative fuels (gas, liquid and solid phase) and in the gasification process which is focused on the generation of syngas (gas phase) and char (solid phase). Numerical simulations concern pyrolysis process of a single solid particle which occurs as a consequence of the particle temperature increase. The research was aimed at an analysis of the influence of particle physical properties on the devolatilization process. In the mathematical modeling the fuel grain is treated as an ideal sphere which consists of porous material (solid and gaseous phase), so as to simplify the final form of the partial differential equations. Assumption that the physical properties change only in the radial direction, reduces the partial derivatives of the angular coordinates. This leads to obtaining the equations which are only the functions of the radial coordinate. The model consists of the mass, momentum and energy equations for porous spherical solid particle heated by the stream of hot gas. The mass source term was determined in the wide range of the temperature according to the experimental data. The devolatilization rate was defined by the Arrhenius formula. The results of numerical simulation show that the heating and devolatilization time strongly depend on the physical properties of fuel. Moreover, proposed model allows to determine the pyrolysis process direction, which is limited by the equilibrium state.
Kinematic and Kinetic Analysis of Two Gymnastics Acrobatic Series to Performing the Backward Stretched Somersault
Authors: Mkaouer Bessem , Jemni Monèm , Amara Samiha , Chaabène Helmi , Tabka Zouhair
Published: July 2013

Back swing connections during gymnastics acrobatic series considerably influence technical performance and difficulties, particularly in the back somersault. The aim of this study was to compare the take-off’s kinetic and kinematic variables between two acrobatic series leading to perform the backward stretched somersault (also called salto): round-off, flic-flac to stretched salto versus round-off, tempo-salto to stretched salto. Five high level male gymnasts (age 23.17 ± 1.61 yrs; body height 1.65 ± 0.05 m; body mass 56.80 ± 7.66 kg) took part in this investigation. A force plate synchronized with a two dimensional movement analysis system was used to collect kinetic and kinematic data. Statistical analysis via the non-parametric Wilcoxon Rank-sum test showed significant differences between the take-offs’ variables. The backswing connections were different in the take-off angle, linear momentum, vertical velocity and horizontal and vertical displacements. In conclusion, considering that the higher elevation of the centre of mass in the flight phase would allow best performance and lower the risk of falls, particularly when combined to a great angular momentum, this study demonstrated that the optimal connection series was round-off, flic-flac to stretched salto which enabled the best height in the somersault. Analysis of the results suggests that both connections facilitate the performance of single and double (or triple) backward somersaults with or without rotations around the longitudinal axis. Gymnasts could perform these later while gaining height if they chose the round-off, flic-flac technique or gaining some backward displacement if they choose the round-off, salto tempo.
Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking
Authors: Lucas-Cuevas Angel G. , Pérez-Soriano Pedro , Bush Michael , Crossman Aaron , Llana Salvador , Cortell-Tormo Juan M. , Pérez-Turpin José A.
Published: July 2013

It is well established nowadays the benefits that physical activity can have on the health of individuals. Walking is considered a fundamental method of movement and using a backpack is a common and economical manner of carrying load weight. Nevertheless, the shock wave produced by the impact forces when carrying a backpack can have detrimental effects on health status. Therefore, the aim of this study was to investigate differences in the accelerations placed on males and females whilst carrying different loads when walking. Twenty nine sports science students (16 males and 13 females) participated in the study under 3 different conditions: no weight, 10% and 20% body weight (BW) added in a backpack. Accelerometers were attached to the right shank and the centre of the forehead. Results showed that males have lower accelerations than females both in the head (2.62 ± 0.43G compared to 2.83 + 0.47G) and shank (1.37 ± 0.14G compared to 1.52 ± 0.15G; p<0.01). Accelerations for males and females were consistent throughout each backpack condition (p>0.05). The body acts as a natural shock absorber, reducing the amount of force that transmits through the body between the foot (impact point) and head. Anthropometric and body mass distribution differences between males and females may result in women receiving greater impact acceleration compared to men when the same load is carried.