Olive oil waste treatment: a comparative and critical presentation of methods, advantages & disadvantages

Since olive oil industries were considered responsible for a great amount of pollution there has been a strong need for optimization of olive oil waste treatment systems. The currently employed systems are numerous and fall in the following large categories; bioremediation (ex-situ, in-situ), thermal processes (incineration, pyrolysis, gasification), evaporation, membrance processes, electrolysis, ozonation, digestion, coagulation/flocculation/precipitation, and distillation. Both advantages and disadvantages in conjunction with respective methodology and explicit flow diagrams were presented per waste treatment method. Furthermore, most recent studies were reported and more than twenty-five figures showing mainly the effectiveness of the current waste treatment methods versus time or temperature were displayed. The comparative presentation of the various olive oil waste treatment methodologies showed that though bioremediation stands for the most enviromentally friendly technique, its required longer treatment time in conjuction with its weakness to deal with elemental contaminants makes imperative the employment of a second alternative technique which could either be a membrance process (low energy cost, reliability, reduced capital cost) or a coagulation/flocculation method because of its low cost and high effectiveness. Biogas production appears to be another promising and energy effective waste treatment method. On the other hand, methods like distillation and ozonation (high cost) and electrolysis (experimental level) are unlikely to dominate this field unless their high cost is substantially reduced in the near future.     

How the structural deviations on the backbone of conjugated polymers influence their optoelectronic properties and photovoltaic performance

The design of novel conjugated polymers with appropriate frontier orbital energy levels, low band gap (LBG) and suitable carrier transport properties are needed to improve the power conversion efficiency (PCE) of organic photovoltaic devices. In this review, a detailed structure-property relationship study is presented, by identifying those chemical entities in the backbone of conjugated polymers that are responsible for the modification of optoelectronic properties towards high photovoltaic performance.     

Knowledge discovery techniques for predicting country investment risk

This paper presents the insights gained from applying knowledge discovery in databases (KDD) processes for the purpose of developing intelligent models, used to classify a country's investing risk based on a variety of factors. Inferential data mining techniques, like C5.0, as well as intelligent learning techniques, like neural networks, were applied to a dataset of 52 countries. The dataset included 27 variables (economic, stock market performance/risk and regulatory efficiencies) on 52 countries, whose investing risk category was assessed in a Wall Street Journal survey of international experts. The results of applying KDD techniques to the dataset are promising, and successfully classified most countries as compared to the experts' classifications. Implementation details, results, and future plans are also presented.     

Use of Multimedia and the World Wide Web in Civil Engineering Learning

The case study method, which has been proven to be a very useful learning tool, can be further enhanced with the use of multimedia and the World Wide Web. This paper demonstrates multimedia and Web-based enhancement with the design and construction of a port, a large-scale civil engineering project. The main purpose was to create an educational tool that brings into the classroom a “real-life” design and construction problem, including the construction field, operation of equipment, and details of construction methods. This enables civil engineering students to better understand the details of the planning, design, and construction of a complicated project. Furthermore, through the use of evaluation tests, feedback on the students’ understanding of the case study can be provided to both the students and the educator. This application can be expanded beyond an academic environment for use as a learning tool in a business environment, which may be especially beneficial for new engineers.     

On the Design of a Dual-Band,Switched-Beam Antenna Array with Constant Excitation Coefficients

A new technique is proposed for the design of dual-band, switched-beam, wire antenna arrays, using the method of genetic algorithms (GA's). The main goal of the proposed technique is the preservation of constant excitation coefficients during operation at different frequency bands. This is accomplished by jointly optimizing the array's technical characteristics for operation at both frequency bands, while properly exploiting mutual coupling between array elements. Numerical results are presented in the case of a uniform, eight-element circular array, with radiation characteristics specified for the 2.4–2.4835 GHz and 3.4–3.8 GHz frequency bands, and excellent agreement to design considerations is demonstrated. Stelios A. Mitilineos was born in Athens, Greece, in 1977. He received the Diploma in electrical and computer engineering from the National Technical University of Athens (NTUA) in October 2001. He is currently working toward the Ph.D. degree in electrical engineering at the same university. His main research interests are in the area of antennas and propagation, smart antennas and mobile communications, MIMO systems and microwave components. Christos N. Capsalis was born in Nafplion, Greece, in 1956. He received the Diploma in electrical and mechanical engineering from the National Technical University of Athens (NTUA) in 1979 and the B. S. degree in economics from the University of Athens in 1983. He obtained the Ph.D. degree in electrical engineering from NTUA in 1985. He is currently a Professor at the department of Electrical and Computer Engineering in NTUA. His current scientific activity concerns satellite and mobile communications, antenna theory and design, and electromagnetic compatibility.     

The Clinical Impact of Increasing the Hemodialysis Dose

Good evidence suggests that improvements in dialysis efficiency reduce morbidity and mortality of hemodialysis (HD) patients. Dialysis efficiency has also been related to better control of arterial blood pressure (BP), anemia, and serum phosphorus levels, and to improvement in patients' nutritional status. Over a 2‐year period, the present self‐controlled study of 34 HD patients (23 men, 11 women; age, 52.6 ± 14.5 years; HD duration, 55.9 ± 61.2 months) looked at the effect on clinical and laboratory parameters of increasing the delivered dialysis dose under a strict dry‐weight policy. Dialysis dose was increased without increasing dialysis time and frequency. A statistically significant increase was seen in delivered HD dose: the urea reduction ratio (URR) increased to 60% ± 10% from 52% ± 8%, and then to 71% ± 7% (p < 0.001); Kt/V_urea increased to 1.22 ± 0.28 from 0.93 ± 0.19, and then to 1.55 ± 0.29 (p < 0.001). A statistically significant increase in hemoglobin concentration also occurred—to 10.8 ± 1.9 g/dL from 10.4 ± 1.7 g/dL, and then to 11.0 ± 1.3 g/dL (p < 0.05 as compared to baseline)—with no significant difference in weekly erythropoietin dose. Statistically significant decreases occurred in the systolic and diastolic blood pressures during the first year; they then remained unchanged. Systolic blood pressure decreased to 131 ± 23 mmHg from 147 ± 24 mmHg (p < 0.001); diastolic blood pressure decreased to 65 ± 11 mmHg from 73 ± 12 mmHg (p < 0.001). Serum albumin increased insignificantly to 4.4 ± 0.4 g/dL from 4.3 ± 0.4 g/dL, and then significantly to 4.6 ± 0.3 g/dL (p = 0.002 as compared to both previous values). Normalized protein catabolic rate increased significantly to 1.16 ± 0.15 g/kg/day from 0.93 ± 0.16 g/kg/ day (p < 0.001), and then to 1.20 ± 0.17 g/kg/day (p < 0.001 as compared to baseline). We conclude that the increases achieved in average Kt/V_urea per hemodialysis session by increasing dialyzer membrane area, and blood and dialysate flows, without increasing dialysis time above 4 hours, in patients hemodialyzed thrice weekly, coupled with strict dry‐weight policy, resulted in improvements in hypertension, nutritional status, and anemia.     

Correlated at the Tail: Implications of Asymmetric Tail-Dependence Across Bitcoin Markets

Computational Economics - This paper is the first to fully characterize the relationship among cross-market Bitcoin prices to provide a complete picture of directional predictability of Bitcoin...     

An addendum on “Three-level designs: Evaluation and comparison for screening purposes”

In our recent paper “Three-Level Designs: Evaluation and Comparison for Screening Purposes”, by the same authors, we investigated and compared the original definitive screening designs and the designs that were constructed from weighing matrices. For this purpose, we used the generalized resolution and minimum aberration criteria as well as the projection estimation capacity criterion from the literature to perform the comparison. After our paper was accepted, it came to our attention that there were four significant papers, published by a number of authors, having related content and these were not mentioned in our paper. With this short addendum, we would like to kindly acknowledge the important contributions from those authors in those newly discovered papers in recent literature and also to include them in the related reference list.     

Decision-aided compensation of severe phase-impairment-induced inter-carrier interference in frequency-selective OFDM

A new, reduced complexity algorithm is proposed for compensating the Inter-Carrier Interference (ICI) caused by severe PHase Noise (PHN) and Residual Frequency Offset (RFO) in OFDM systems. The algorithm estimates and compensates the most significant terms of the frequency domain ICI process, which are optimally selected via a Minimum Mean Squared Error (MMSE) criterion. The algorithm requires minimal knowledge of the phase process statistics, the estimation of which is also considered. The scheme outperforms previously proposed compensation methods of similar complexity, when severe phase impairments are present.     

A semantic grid infrastructure enabling integrated access and analysis of multilevel biomedical data in support of postgenomic clinical trials on cancer.

This paper reports on original results of the Advancing Clinico-Genomic Trials on Cancer integrated project focusing on the design and development of a European biomedical grid infrastructure in support of multicentric, postgenomic clinical trials (CTs) on cancer. Postgenomic CTs use multilevel clinical and genomic data and advanced computational analysis and visualization tools to test hypothesis in trying to identify the molecular reasons for a disease and the stratification of patients in terms of treatment. This paper provides a presentation of the needs of users involved in postgenomic CTs, and presents such needs in the form of scenarios, which drive the requirements engineering phase of the project. Subsequently, the initial architecture specified by the project is presented, and its services are classified and discussed. A key set of such services are those used for wrapping heterogeneous clinical trial management systems and other public biological databases. Also, the main technological challenge, i.e. the design and development of semantically rich grid services is discussed. In achieving such an objective, extensive use of ontologies and metadata are required. The Master Ontology on Cancer, developed by the project, is presented, and our approach to develop the required metadata registries, which provide semantically rich information about available data and computational services, is provided. Finally, a short discussion of the work lying ahead is included.