Search results for "97"
showing 10 items of 1081 documents
Green Synthesis, Molecular Characterization and Associative Behavior of Some Gemini Surfactants without a Spacer Group.
2013
A series of new gemini surfactants without a spacer group, disodium 2,3-dialkyl-1,2,3,4-butanetetracarboxylates, were synthesized in a green chemistry context minimizing the use of organic solvents and applying microwaves (MW) when activation energy was required. Once the desired architecture was confirmed by means of the nuclear magnetic resonance technique (1H-NMR, 1H-1H COSY) for all the studied surfactants, the critical micellization concentration was determined by conductance measurements. The diffusion coefficient of micelles formed by the four compounds was characterized using pulsed field gradient (PFG)-NMR. Diffusion coefficients were found to be dependent on the concentration and …
Gutenberg : drama en tres actos
1869
A la portada: “Representado por primera vez en el Teatro de Novedades, con extraordinario aplauso, en la noche del 12 de Febrero de 1869”
Regulación de las modificaciones óseas en la madre durante la gestación
2015
El embarazo constituye un modelo donde se produce el desarrollo del esqueleto fetal en un corto lapso de tiempo. Este logro se lleva a cabo bajo la tutela del propio feto, que gobierna este proceso a través de las señales generadas en la denominada unidad feto-placentaria. El organismo materno sufre un proceso de adaptación donde se produce un drástico reajuste en mecanismos implicados en el recambio óseo. Entre los cambios más evidentes detectables en sangre materna están los incrementos con la edad gestacional de los niveles de calcitriol, de la hormona de crecimiento de origen placentario, del factor de crecimiento similar a la insulina tipo I (IGF-1), de estrógenos, y de prolactina. Tam…
Successive alkalinity producing system for the treatment of acid sulphate soil runoff: preliminary results of a field trial
2005
A successive alkalinity producing system (SAPS) has been investigated as a potential passive treatment option for acid, metal containing runoff from acid sulphate soil. A pilot-scale system was installed at an agricultural land site in Rintala embankment area in mid-western Finland. The experimental layout consists of three parallel treatment units: two different SAPS cells and one limestone-filled cell for comparison of performance. The SAPS cells are composed of a bottom layer of limestone and a top layer of compost supplemented with sand. One of the SAPS cells contains sulphate-rich, waste gypsum mixed with the compost layer in order to enhance the metal reduction by sulphate reducing-ba…
Agroecological engineering
2015
Earth has recently entered the new era of the Anthropocene, during which the rise of human activities are impacting for the first time ecosystems and climate on the global scale. Since the 1960s the green revolution has improved food production in quantity using industrially-designed agriculture, which has led to global pollution by pesticides and losses of food quality, biodiversity and soil carbon. As a consequence there is a need to implement agroecological practices in order to produce food safely and in a sustainable way. This virtual issue presents principles and applications of agroecological engineering, exemplified in 19 selected review articles from the journal Agronomy for Sustai…
A Novel Systolic Parallel Hardware Architecture for the FPGA Acceleration of Feedforward Neural Networks
2019
New chips for machine learning applications appear, they are tuned for a specific topology, being efficient by using highly parallel designs at the cost of high power or large complex devices. However, the computational demands of deep neural networks require flexible and efficient hardware architectures able to fit different applications, neural network types, number of inputs, outputs, layers, and units in each layer, making the migration from software to hardware easy. This paper describes novel hardware implementing any feedforward neural network (FFNN): multilayer perceptron, autoencoder, and logistic regression. The architecture admits an arbitrary input and output number, units in la…
Optimizing the Performance of Data Warehouse by Query Cache Mechanism
2022
Fast access of data from Data Warehouse (DW) is a need for today’s Business Intelligence (BI). In the era of Big Data, the cache is regarded as one of the most effective techniques to improve the performance of accessing data. DW has been widely used by several organizations to manage data and use it for Decision Support System (DSS). Many methods have been used to optimize the performance of fetching data from DW. Query cache method is one of those methods that play an effective role in optimization. The proposed work is based on a cache-based mechanism that helps DW in two aspects: the first one is to reduce the execution time by directly accessing records from cache memory, and th…
Rakastumisia kaupunkiin : Helsingin kaupunginmuseon erikoisnäyttelyt 1970-luvulla
2017
Tutkielmassa käsitellään Helsingin kaupunginmuseon erikoisnäyttelyitä vuosina 1967–1983. Tarkastelun painopiste on 1970-luvun näyttelyissä. Tutkimusajanjakso alkaa museon ensimmäisestä erikoisnäyttelystä ja päättyy päätökseen, jonka jälkeen museossa alettiin järjestää vuosittain yksi suurempi erikoisnäyttely, ns. päänäyttely. Erikoisnäyttelytoiminta on käynnistynyt Suomen kulttuurihistoriallisissa museoissa aktiivisemmin 1970-luvulla. Tuolloin näyttelytoiminnan kehittämiseen suhtauduttiin avoimesti ja toimintaan haettiin uusia muotoja. Tutkielmassa erikoisnäyttelyitä lähestytään historiatutkimuksen näkökulmasta, sekä näyttelyitä tarkemmin analysoiden. Tutkielman pääkysymys liittyy siihen, m…
Nuevas aportaciones al corpus pictórico valenciano del primer renacimiento: Rodrigo de Osona, Maestro de Perea, y Pere Cabanes I
2016
Decoupled Downlink-Uplink Coverage Analysis with Interference Management for Enriched Heterogeneous Cellular Networks
2016
Heterogeneous cellular networks (HetCNets) offer a promising solution to cope with the current cellular coverage crunch. Due to the large transmit power disparity, while following maximum power received (MPR) association scheme, a larger number of users are associated with macro-cell BS (MBS) than small-cell BSs (SBSs). Therefore, an imbalance load arrangement takes place across the HetCNets. Hence, using cell range expansion-based cell association, we can balance the load across the congested MBS. However, using MPR association scheme, users’ offloading leads to two challenges: 1) macro-cell interference , in which the MBS interferes with the offloaded users, and 2) coupled downlink-uplink…