Numerical study of confinement effectiveness in solid and hollow reinforced concrete bridge piers: Analysis results and discussion

This paper presents the outcome of a large parametric numerical analysis of solid and hollow reinforced concrete piers taken from actually constructed bridges, based on a consistent three-dimensional nonlinear finite element methodology that was presented in a companion paper. Various transverse reinforcement arrangements and spacings were examined, as well as the effect of high-strength concrete on confinement effectiveness. The interpretation of numerical results mainly focuses on identifying the most convenient confinement configurations in terms of enhanced strength and ductility, as well as ease of construction and cost effectiveness. Furthermore, issues regarding confinement arrangements (often used in practice) that result in reduced section ductility are investigated and possible remedies are suggested. Finally, the broad applicability of the proposed methodology is established by application to a particularly complex (in terms of geometry and reinforcement detailing) hollow pylon section.     

Automotive industry challenges in meeting EU 2015 environmental standard

Automotive Shredder Residue (ASR) generation in EU is approximately 2–2.5 million t/y, constituting 10% of total hazardous waste in the EU. Currently, about 75% of ELVs total weight is recycled while the remaining 25% (ASR). Not surprisingly, Europe is the world’s largest vehicle producer as about 30% of the 50 million cars produced globally are manufactured in the EU. Worldwide, ASR is considered an increasingly problematic waste, consisting of a large number of different materials that basically remains unprocessed and directed to landfills. The aim of this study is to provide an overview of the ASR problem and the options for processing this waste in order to minimize the waste directed to landfills.     

Challenging Hurdles of Current Targeting in Glioblastoma: A Focus on Immunotherapeutic Strategies

Glioblastoma is the most frequent primary neoplasm of the central nervous system and still suffers from very poor therapeutic impact. No clear improvements over current standard of care have been made in the last decade. For other cancers, but also for brain metastasis, which harbors a very distinct biology from glioblastoma, immunotherapy has already proven its efficacy. Efforts have been pursued to allow glioblastoma patients to benefit from these new approaches, but the road is still long for broad application. Here, we aim to review key glioblastoma immune related characteristics, current immunotherapeutic strategies being explored, their potential caveats, and future directions.     

A Low-Complexity PTS-based PAPR Reduction Technique for OFDM Signals without Transmission of Side Information

Increased peak-to-average power ratio (PAPR) imposes a design challenge for orthogonal frequency division multiplexing-based signals. An efficient technique to address the increased PAPR problem is the partial transmit sequences (PTS) approach. A significant drawback of PTS is the fact that it multiplies the transmitted symbol with weighting factors selected by the transmitter. Since the weighting factors are required for decoding, they are explicitly transmitted, in most cases. This paper proposes a new low-complexity technique for retrieving the weighting factors in the receiver. The proposed decoder uses the predefined values of pilot tones and explores all the permissible combinations of weighting factors in order to identify the factor combination employed by the transmitter. The proposed decoder requires no additional pilot tones or explicit transmission of side information, therefore no data rate loss is implied. Furthermore this paper presents a digital very large scale integration implementation of the proposed PTS decoder and demonstrates its low-power properties.     

A lattice-based neuro-computing methodology for real-time human action recognition

This work describes a computational approach for a typical machine-vision application, that of human action recognition from video streams. We present a method that has the following advantages: (a) no human intervention in pre-processing stages, (b) a reduced feature set, (c) modularity of the recognition system and (d) control of the model’s complexity in acceptable for real-time operation levels. Representation of each video frame and feature extraction procedure are formulated in the lattice theory context. The recognition system consists of two components: an ensemble of neural network predictors which correspond to the training video sequences and one classifier, based on the PREMONN approach, capable of deciding at each time instant which known video source has potentially generated a new sequence of frames. Extensive experimental study on three well known benchmarks validates the flexibility and robustness of the proposed approach.     

Promoting effective service differentiation with Size-oriented Queue Management

As the heterogeneity of Internet traffic increases, the need to provide the necessary quality guarantees for a broad range of applications becomes more and more important. We propose an Active Queue Management scheme, namely Size-oriented Queue Management, which realizes service differentiation based on the Less Impact–Better Service principle. SQM manages to satisfy broadly the quality constraints of real-time applications, without compromising the performance of bulk data applications. Using packet size as criterion, we are able to distinguish time-sensitive flows and apply different dropping and scheduling policies to favor time-sensitive traffic. Our simulation results indicate that SQM manages to increase application satisfaction and augment the user-perceived quality.     

Fast convergence to network fairness

Most AQM algorithms, such as RED, assure fairness through randomness in congestion notification. However, randomness results in fair allocation of network resources only when time limitations are not considered. This is not compatible with the current Internet, where traffic oscillations are frequent and the demand for fair treatment is rather urgent, due to short duration of most applications. Given the short duration of most modern Internet applications, fast convergence to fairness is necessitated. In this paper, we use fairness as the major criterion to adjust traffic and present a corresponding algorithm of active queue management, which is called Explicit Global Congestion Notifier (EGCN). EGCN notifies flows almost simultaneously about incipient congestion by marking packets arriving at the router’s queue, when the load in the network increases and buffer overflow is expected. This is a new approach compared with the random notification policy of RED or ECN. EGCN distributes the burden to adjust backward to more flows and consequently allows for smoother window adjustments. We elaborate on the properties of system-wide response in terms of fairness, smoothness and efficiency. Simulation results demonstrate a clear-cut advantage of the proposed scheme.     

Quality Characteristics and Antioxidants of Mavrolia cv. Virgin Olive Oil

The quality characteristics and bioactive microconstituents of virgin olive oil produced by Mavrolia cv, an Olea europaea variety grown in Southern Peloponnesus, Greece, are reported for the first time. The oil samples of Mavrolia cv. studied fell within the limits established for the extra virgin olive oil (EVOO) category and were characterized by higher levels of campesterol (88.7 ± 14.8 vs. 56.1 ± 6.1 mg kg⁻¹ oil) and β-sitosterol (1692.6 ± 100.3 vs. 1356.2 ± 85 mg kg⁻¹ oil) and relatively lower oxidative stability (19.35 ± 2.62 vs. 37.44 ± 1.97 h) compared to Koroneiki cv. The lower oxidative stability was positively correlated to significantly lower polyphenols (88.95 ± 2.33 vs. 233.75 ± 34.29) and α-tocopherol (517.2 ± 6.50 vs. 655.37 ± 17.78) and to higher polyunsaturated fatty acids content (9.27 ± 0.35 vs. 6.41 ± 0.38). Tyrosol, ferulic acid and protocatechuic acid contents were significantly higher in Mavrolia cv. samples compared to Koroneiki cv. (218.80 ± 44.8 vs. 83.7 ± 23.1, 1.82 ± 0.11 vs. 0.97 ± 0.31, and 1.55 ± 0.39 vs. 0.35 ± 0.60 mg kg⁻¹, respectively). Also, the bitter and pungent attributes were found in lower intensities compared to Koroneiki cv. EVOO for the same period (1.9 vs. 2.5 and 2.3 vs. 3.9, respectively). The ripe fruity intensity with walnut olfactory attribute of the Mavrolia cv., was also light to medium.     

The effect of heat processing on the functional properties of pectin contained in olive mill wastewater

The purpose of this study was to evaluate the effect of prolonged heat processing (180 min at 50-80 °C) on the functional and rheological properties of pectin, derived from olive mill wastewater (OMW). It was shown that a low temperature blanching of OMW at 60 °C, activates endogenous pectin methyl esterase and promotes demethylation, despite the high concentration of phenols. Activation of the enzyme resulted in enhanced solubilization and subsequent partial degradation of pectin. The induced degradation impaired pectin grade and resulted in loss of gelling functionality. An alternative heating process at 80 °C resulted in negligible enzyme induced degradation of the pectin and improved gelling properties of the recovered material, despite the lower solubilization of the pectin. The obtained results contribute to a better understanding of the temperature effect on pectin functional properties and can be utilized in order to optimize pectin recovery from OMW.     

Clarification of high-added value products from olive mill wastewater

The objective of the current study is to investigate the clarification of two high-added value products (pectin containing solution and phenol containing beverage) recovered from olive mill wastewater. For this purpose, both liquids were processed with four types of ultrafiltration (100, 25, 10 and 2 kDa) and one nanofiltration membranes under optimum transmembrane pressure. Retention coefficients and performance parameters were monitored for each experiment. The membranes of 25 and 100 kDa showed very satisfying results with regard to the concentration of pectin solutions as they were able to separate it from cations and phenols. The membrane of 25 kDa was also able to partially remove the heavier fragments of hydroxycinnamic acid derivatives and flavonols, and simultaneously to sustain the antioxidant properties of the phenol containing beverage in the permeate stream. Finally, nanofiltration clarified the beverage from cations that passed in the permeate stream, but this process resulted in loss of antioxidant compounds, too.