7,506 research outputs found
Influence of shallow cycling on the ageing of SLI batteries
Lead-acid batteries have different uses ever since they were invented. It is found interesting and usable to investigate the ageing of battery over time, and therefore to determine the batteries cycle life and performance in different situations, remarking the automotive industry and power supply systems, among others. Nowadays lead-acid batteries with an infinite cycle life would be ideal for the applications where they are used. It is considered impossible to build an infinite cycle life battery, reason by which engineers have been looking forward to increase batteries' cycle life. The main objective of the thesis is to analyse the effect of cycle depth for the measurements data provided by the ISEA Department and to obtain each battery's rate of ageing. The finite life of the batteries is due to the occurrence of unwanted chemical or physical changes, or the loss of the active materials from which they are made; otherwise they would last indefinitely. These changes are usually irreversible and they affect the electrical performance of the cell, increasing the internal resistance, decreasing the capacity, and reducing the battery cycle life
Influence of shallow cycling on the ageing of SLI batteries
Lead-acid batteries have different uses ever since they were invented. It is found interesting and usable to investigate the ageing of battery over time, and therefore to determine the batteries cycle life and performance in different situations, remarking the automotive industry and power supply systems, among others. Nowadays lead-acid batteries with an infinite cycle life would be ideal for the applications where they are used. It is considered impossible to build an infinite cycle life battery, reason by which engineers have been looking forward to increase batteries' cycle life. The main objective of the thesis is to analyse the effect of cycle depth for the measurements data provided by the ISEA Department and to obtain each battery's rate of ageing. The finite life of the batteries is due to the occurrence of unwanted chemical or physical changes, or the loss of the active materials from which they are made; otherwise they would last indefinitely. These changes are usually irreversible and they affect the electrical performance of the cell, increasing the internal resistance, decreasing the capacity, and reducing the battery cycle life
Adquisició i desenvolupament de la competència matemàtica
Els currículums actuals es basen en vuit competències que han d'adquirir tots els alumnes, anomenades competències bàsiques. Una competència es considera una capacitat per actuar eficaçment, i l'adquisició de totes vuit hauria de permetre als alumnes la interpretació crítica i constructiva de la realitat que els envolta. En particular, la competència matemàtica hauria de permetre'ls produir informació per resoldre problemes quotidians i prendre decisions.Acquisition and development of mathematical competence. Current curricula are based on eight key skills that all pupils must acquire. Key skills allow us to act effectively and the acquisition of all eight should give pupils the competence to critically and constructively interpret the reality that surrounds them. In particular, mathematical competence should enable them to produce more information to solve everyday problems and make decisions
Desenvolupament de la metodologia per a l’avaluació de broquets per a l’aplicació de productes fitosanitaris
The plant protection products are, nowadays, very important for the agriculture, since they reduce the losses caused by pests and diseases on the crops. A bad use of these products can drive to a contamination of the environment or fruits collected. Therefore, we need to carry out an efficient distribution to maximize the performance of the plant protection products and reduce possible environmental problems. The nozzles are a key element for the correct spray during the application of the plant protection products. Factors such as the nozzle flow rate to be applied, the working pressure, the formation of the drops, the distribution on the objective, the penetration, etc., make the choice of the appropriate nozzle very important. That is why we also need correct certification and assessment methodologies to verify that the nozzles really behave as the manufacturer says. The objective of the present work is to develop and fine-tune the methodology for the evaluation of the nozzles for the application of phytosanitary products according to ISO 5682-1 "Equipment for crop protection - Spraying equipment, Part1: test methods for sprayer nozzles" and ISO 16119-2 "Agricultural and Forestry Machinery - Environmental requirements for sprayers, Part 2: Horizontal boom sprayers". We will evaluate 5 types of nozzles of the "Agroplast" house; Three simple fan types called 6MS04C, 6MS03C and 8MS1100C, and two dual fan called 6MS05C2 and 8MS11004P2. We will evaluate them at three different pressures and at three different heights. The characteristics of the nozzles on which we will focus will be the flow rate, the horizontal distribution of the 20 nozzles mounted on a 10-meter spray boom, the horizontal distribution on each nozzle individually, and the spray angle. We will also measure the characteristics of a standard nozzle to compare it with the other 5 nozzles and see what they give us. According to the obtained results we can see that the nozzle with a more difference between the nominal flow rate is the model 6MS03C, and that the nozzle with worse multiple horizontal distribution is the model 8MS11004P2. Regarding to the individual horizontal distribution we can observe how the amount of water at the ends of the fans increases as we increase the pressure, because the angle of the fan also increases. We can confirm that it is a good methodology, since it ensures reliable results thanks to the type of tests and the amount of repetitions.Los productos fitosanitarios son, hoy en día, muy importantes para la agricultura, ya que reducen las perdidas por plagas y enfermedades de los cultivos. Pero una mala utilización de estos puede causar una contaminación del entorno o del mismo alimento. Por lo que necesitamos llevar a cabo una distribución eficiente para maximizar el rendimiento de los productos fitosanitarios y reducir posibles problemas para el medio ambiente. Las boquillas son un elemento clave para la correcta pulverización durante la aplicación de los productos fitosanitarios. Factores como el caudal a aplicar, la presión de trabajo, la formación de las gotas, la distribución sobre el objetivo, la penetración, etc., hacen que la elección de la boquilla adecuada sea muy importante. Es por eso, que también hacen falta metodologías de certificación y evaluación correctas para comprobar que las boquillas realmente se comportan como dice el fabricante. El objetivo del presente trabajo es desarrollar y poner a punto la metodología para la evaluación de las boquillas para la aplicación de productos fitosanitarios según la norma ISO 5682-1 “Equipment for crop protection – Spraying equipment, Part1: test methods for sprayer nozzles” y la ISO 16119-2 “Agricultural and Forestry Machinery – Environmental requirements for sprayers, Part 2: Horizontal boom sprayers”. Evaluaremos 5 tipos de boquillas de la casa "Agroplast"; tres de abanico simple llamados 6MS04C, 6MS03C y 8MS1100C, y dos de abanico doble llamados 6MS05C2 y 8MS11004P2. Los evaluaremos a tres presiones diferentes y en tres alturas diferentes. Las características de las boquillas en las cuales nos centraremos serán el caudal, la distribución horizontal de las 20 boquillas montadas en una barra de 10 metros, la distribución horizontal en cada boquilla individualmente, i el ángulo de polvorización. También mediremos las características de una boquilla estándar para compararla con otras 5 boquillas y ver que nos aportan. Según los resultados obtenidos podemos ver que la boquilla con un caudal más diferente respeto el caudal nominal es la 6MS03C, y que la boquilla con peor distribución horizontal múltiple es la 8MS11004P2. Por lo que hace referencia a la distribución horizontal individual vemos como la cantidad de agua en los extremos de los abanicos aumenta a medida que aumentamos la presión, debido a que el ángulo del abanico también aumenta. Podemos afirmar que se trata de una buena metodología, ya que asegura resultados fiables gracias a la tipología de ensayos y nombre de repeticiones.Els productes fitosanitaris són, avui en dia, molt importants per l’agricultura, ja que redueixen les pèrdues causades per plagues o malalties dels cultius. Però una mala utilització d’aquests pot comportar una contaminació de l’entorn o del mateix aliment. És per això que necessitem dur a terme una distribució eficient per maximitzar el rendiment dels productes fitosanitaris i reduir possibles problemes en el medi ambient. Els broquets són un element clau per realitzar una correcta polvorització durant l’aplicació de productes fitosanitaris. Factors com el cabal a aplicar, la pressió de treball, la formació de les gotes, la distribució sobre l’objectiu, la penetració, etc., fan que l’elecció del broquet adient sigui molt important. És per això, que també fan falta metodologies de certificació i avaluació correctes per comprovar que els broquets realment es comporten com diu el fabricant. L’objectiu del present treball és desenvolupar i posar a punt la metodologia per a l’avaluació de broquets per a l’aplicació de productes fitosanitaris segons la ISO 5682-1 “Equipment for crop protection – Spraying equipment, Part1: test methods for sprayer nozzles” i la ISO 16119- 2 “Agricultural and Forestry Machinery – Environmental requirements for sprayers, Part 2: Horizontal boom sprayers”. Avaluarem 5 tipus de broquets de la casa “Agroplast”; tres de ventall simple anomenats 6MS04C, 6MS03C i 8MS1100C, i dos de ventall doble anomenats 6MS05C2 i 8MS11004P2. Els avaluarem a tres pressions diferents i a tres alçades diferents. Les característiques dels broquets en les quals ens centrarem en avaluar seran el cabal, la distribució horitzontal de 20 broquets muntats en una barra de 10 metres, la distribució horitzontal de cada broquet individualment, i l’angle de polvorització. També mesurarem les característiques d’un broquet estàndard per comprar-lo amb els altres 5 broquets i veure que ens aporten. Segons els resultats obtinguts podem veure que el broquet amb un cabal més diferent respecte el cabal nominal és el 6MS03C, i que el broquet amb pitjor distribució horitzontal múltiple és el 8MS11004P2. Pel que fa a la distribució horitzontal individual veiem com la quantitat d’aigua en els extrems del ventall augmenta a mesura que augmentem la pressió, degut a que l’angle del ventall també augmenta. Podem afirmar que es tracta d’una bona metodologia, ja que assegura resultats fiables gràcies a la tipologia d’assajos i nombre de repeticions
Binding “When” and “Where” Impairs Temporal, but not Spatial Recall in Auditory and Visual Working Memory
Information about where and when events happen seem naturally linked to each other, but only few studies have investigated whether and how they are associated in working memory. We tested whether the location of items and their temporal order are jointly or independently encoded. We also verified if spatio-temporal binding is influenced by the sensory modality of items. Participants were requested to memorize the location and/or the serial order of five items (environmental sounds or pictures sequentially presented from five different locations). Next, they were asked to recall either the item location or their order of presentation within the sequence. Attention during encoding was manipulated by contrasting blocks of trials in which participants were requested to encode only one feature to blocks of trials where they had to encode both features. Results show an interesting interaction between task and attention. Accuracy in serial order recall was affected by the simultaneous encoding of item location, whereas the recall of item location was unaffected by the concurrent encoding of the serial order of items. This asymmetric influence of attention on the two tasks was similar for the auditory and visual modality. Together, these data indicate that item location is processed in a relatively automatic fashion, whereas maintaining serial order is more demanding in terms of attention. The remarkably analogous results for auditory and visual memory performance, suggest that the binding of serial order and location in working memory is not modality-dependent, and may involve common intersensory mechanisms
Revealing the proliferation of hydrogen scavengers in a single-chamber microbial electrolysis cell using electron balances
The bioelectrochemical generation of hydrogen in microbial electrolysis cells (MECs) is a promising technology with many bottlenecks to be solved. Among them, the proliferation of hydrogen scavengers drastically reduces the cell efficiency leading to unrealistic coulombic efficiencies (CE) and cathodic gas recoveries (rCAT). This work provides a novel theoretical approach to understand, through electron equivalent balances, the fate of hydrogen in these systems. It was validated with a long term operated single-chamber membrane-less MEC. In the short term, H2-recycling (i.e. hydrogen being derived to the anode) resulted in rCAT of only 4% and in CE up to 463%. The 80.5% of the current intensity came from H₂-recycling and only the 19.5% from substrate oxidation. In the long term, methane was produced from hydrogen, thus decreasing rCAT to 0 (rCAT ¼ 94.5% when considering methane production). CE was 74.5% suggesting that H₂-recycling only took place when methanogenic activity was marginal
高周波イオン源に及ぼす軸方向磁場の影響
Abstract
Objective To examine whether first trimester fetal growth restriction
correlates with cardiovascular outcomes in childhood.
Design Population based prospective cohort study.
Setting City of Rotterdam, the Netherlands.
Participants 1184 children with first trimester fetal crown to rump length
measurements, whose mothers had a reliable first day of their last
menstrual period and a regular menstrual cycle.
Main outcomes measures Body mass index, total and abdominal fat
distribution, blood pressure, and blood concentrations of cholesterol,
triglycerides, insulin, and C peptide at the median age of 6.0 (90% range
5.7-6.8) years. Clustering of cardiovascular risk factors was defined as
having three or more of: high android fat mass; high systolic or diastolic
blood pressure; low high density lipoprotein cholesterol or high
triglycerides concentrations; and high insulin concentrations.
Results One standard deviation score greater first trimester fetal crown
to rump length was associated with a lower total fat mass (−0.30%, 95%
confidence interval −0.57% to −0.03%), android fat mass (−0.07%,
−0.12% to −0.02%), android/gynoid fat mass ratio (−0.53, −0.89 to −0.17),
diastolic blood pressure (−0.43, −0.84 to −0.01, mm Hg), total cholesterol
(−0.05, −0.10 to 0, mmol/L), low density lipoprotein cholesterol (−0.04,
−0.09 to 0, mmol/L), and risk of clustering of cardiovascular risk factors
(relative risk 0.81, 0.66 to 1.00) in childhood. Additional adjustment for
gestational age and weight at birth changed these effect estimates only
slightly. Childhood body mass index fully explained the associations of
first
Phenotyping the histopathological subtypes of non-small-cell lung carcinoma: how beneficial is radiomics?
The aim of this study was to investigate the usefulness of radiomics in the absence of well-defined standard guidelines. Specifically, we extracted radiomics features from multicenter computed tomography (CT) images to differentiate between the four histopathological subtypes of non-small-cell lung carcinoma (NSCLC). In addition, the results that varied with the radiomics model were compared. We investigated the presence of the batch effects and the impact of feature harmonization on the models' performance. Moreover, the question on how the training dataset composition influenced the selected feature subsets and, consequently, the model's performance was also investigated. Therefore, through combining data from the two publicly available datasets, this study involves a total of 152 squamous cell carcinoma (SCC), 106 large cell carcinoma (LCC), 150 adenocarcinoma (ADC), and 58 no other specified (NOS). Through the matRadiomics tool, which is an example of Image Biomarker Standardization Initiative (IBSI) compliant software, 1781 radiomics features were extracted from each of the malignant lesions that were identified in CT images. After batch analysis and feature harmonization, which were based on the ComBat tool and were integrated in matRadiomics, the datasets (the harmonized and the non-harmonized) were given as an input to a machine learning modeling pipeline. The following steps were articulated: (i) training-set/test-set splitting (80/20); (ii) a Kruskal-Wallis analysis and LASSO linear regression for the feature selection; (iii) model training; (iv) a model validation and hyperparameter optimization; and (v) model testing. Model optimization consisted of a 5-fold cross-validated Bayesian optimization, repeated ten times (inner loop). The whole pipeline was repeated 10 times (outer loop) with six different machine learning classification algorithms. Moreover, the stability of the feature selection was evaluated. Results showed that the batch effects were present even if the voxels were resampled to an isotropic form and whether feature harmonization correctly removed them, even though the models' performances decreased. Moreover, the results showed that a low accuracy (61.41%) was reached when differentiating between the four subtypes, even though a high average area under curve (AUC) was reached (0.831). Further, a NOS subtype was classified as almost completely correct (true positive rate similar to 90%). The accuracy increased (77.25%) when only the SCC and ADC subtypes were considered, as well as when a high AUC (0.821) was obtained-although harmonization decreased the accuracy to 58%. Moreover, the features that contributed the most to models' performance were those extracted from wavelet decomposed and Laplacian of Gaussian (LoG) filtered images and they belonged to the texture feature class.. In conclusion, we showed that our multicenter data were affected by batch effects, that they could significantly alter the models' performance, and that feature harmonization correctly removed them. Although wavelet features seemed to be the most informative features, an absolute subset could not be identified since it changed depending on the training/testing splitting. Moreover, performance was influenced by the chosen dataset and by the machine learning methods, which could reach a high accuracy in binary classification tasks, but could underperform in multiclass problems.It is, therefore, essential that the scientific community propose a more systematic radiomics approach, focusing on multicenter studies, with clear and solid guidelines to facilitate the translation of radiomics to clinical practice
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