Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 4 )

2019 ( 359 )

2018 ( 432 )

2017 ( 454 )

Custom range...

Search Results: 1 - 10 of 374321 matches for " C. P. Providakis "
All listed articles are free for downloading (OA Articles)
Page 1 /374321
Display every page Item
Nondestructive Wireless Monitoring of Early-Age Concrete Strength Gain Using an Innovative Electromechanical Impedance Sensing System
C. P. Providakis,E. V. Liarakos,E. Kampianakis
Smart Materials Research , 2013, DOI: 10.1155/2013/932568
Abstract: Monitoring the concrete early-age strength gain at any arbitrary time from a few minutes to a few hours after mixing is crucial for operations such as removal of frameworks, prestress, or cracking control. This paper presents the development and evaluation of a potential active wireless USB sensing tool that consists of a miniaturized electromechanical impedance measuring chip and a reusable piezoelectric transducer appropriately installed in a Teflon-based enclosure to monitor the concrete strength development at early ages and initial hydration states. In this study, the changes of the measured electromechanical impedance signatures as obtained by using the proposed sensing system during the whole early-age concrete hydration process are experimentally investigated. It is found that the proposed electromechanical impedance (EMI) sensing system associated with a properly defined statistical index which evaluates the rate of concrete strength development is very sensitive to the strength gain of concrete structures from their earliest stages. 1. Introduction Since accurate field measurements of early-age concrete properties, such as setting time, in-place strength gain, and shrinkage stresses, are crucial to in situ quality control of concrete, various techniques have been proposed including Windsor and pullout probe tests, ultrasonic pulse velocity, impact-echo method, microwave method, and maturity method [1]. Those nondestructive techniques interactively measure certain mechanical properties of the concrete from which information on the strength is derived. However, although mechanical wave velocity methods such as the ultrasonic pulse velocity and impact-echo methods are widely used to test in a nondestructive manner, they have some limitations that restrict practical applications. Thus, mainly due to their serious drawbacks they received little interest from the construction community. Besides, these methods use extensive wiring systems to operate and necessitate special equipment to gain access to the structure during construction. In addition, these techniques perform localized measurements, and the monitoring of large concrete structures requires an extensive amount of time and effort leading to costly usage. Substructures such as concrete foundations and piles are inaccessible and their early-age strength development cannot be evaluated using these monitoring systems. The advent of smart materials, such as piezoelectric materials, shape-memory alloys, and optical fibers, has attracted interests among researchers and engineers to develop new
Economically Precise Water Resource Management for Domestic Usage in India  [PDF]
P. Babu, C. Rajasekaran
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.710240
Abstract: In the present years water resource that can be utilized for domestic usage is getting reduced dramatically. In order to have sufficient water for the utilization of future generation, it is our duty to conserve and utilize the available water in a very efficient way. This paper is aimed to help the people to conserve water; it is done with the help of an embedded system that is reconfigurable depending on the number of persons in the family. The system consists of three modules. Each has a different purpose, one module senses the water level present in the tank and intimates the user regarding when the water is needed to be restored. The second module deals with the division of water based on the type of application for which is intended. The third module deals with intimating the municipality regarding the availability of water. All the three modules combine to work in conserving the water; as a result, we can consume nearly 30% per year per head. So this would result in a large amount of conservation of water. Thus the saved water can be reused for several applications.
Farmer’s Perception of Cassava Mosaic Disease, Preferences and Constraints in Lupaula Province of Zambia  [PDF]
P. C. Chikoti, R. Melis, P. Shanahan
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.77108
Abstract: Cassava is the principal staple root crop, providing a major source of calories for rural and urban households in Luapula province of Zambia. However, the yields on smallholder farms are relatively low largely due to disease infections. The study was therefore conducted to establish farmers’ perceptions, knowledge and management of cassava mosaic disease (CMD), which is one of the major diseases of cassava, and to establish farmers’ preferred traits, constraints and assess sources of cassava cuttings for planting. Focus group discussions (FGD) and structured interviews involving 156 farmers in Mwense, Mansa and Samfya districts were conducted from December 2008 to March 2009. Knowledge of CMD was limited among the respondents. Only 2.4% of the respondents were aware of the disease despite high CMD incidence in farmers’ fields. The majority of the farmers were aware of the importance of insect pests; however, they could not differentiate between damages due to diseases or insect pests. High yield and early bulking traits were highly ranked. Most of the farmers planted local landraces on small-fields (<1 ha). It was evident that a local breeding programme aimed at developing locally adapted disease and pest resistant cassava cultivars was a pressing requirement.
Depression in Chronic Kidney Disease and Hemodialysis Patients  [PDF]
C. P. Andrade, R. C. Sesso
Psychology (PSYCH) , 2012, DOI: 10.4236/psych.2012.311146
Abstract: Depression is the most common psychiatric condition in Chronic Kidney Disease (CKD), but there are few studies that analyzed this condition in patients in different phases of disease. This article aims to evaluated depression in CKD patients, comparing patients in different phases of disease. Methods: We evaluated 134 patients with CKD submitted to conservative ambulatory treatment, and 36 patients with end-stage renal disease undergoing hemodialysis (HD). To evaluate depression, we used the Beck Depression Inventory (BDI), and the Beck Depression Inventory—SF (BDI-SF), a subscale that allows evaluate only the cognitive aspects of depression. Functional capacity was evaluated using the Karnofsky Performance Scale, and clinical and sociodemographic variables were also investigated. Results: Using BDI, depression was identified in 37.3% of patients in conservative treatment and in 41.6% in HD patients (p > 0.05). This percentage reduced when the BDI-SF was used, to 11.1% in conservative CKD patients and 13.8% in HD patients (p > 0.05). Depression was associated with marital status, professional activity, income, comorbidities and functional capacity. Discussion: We observed high prevalence of depression in patients with CKD undergoing conservative or hemodialysis treatment. Depression was associated with some clinical and sociodemografic variables and with functional capacity.
Crystallization and Characterization of a New NonLinear Optical Crystal: L Proline Succinate (LPS)  [PDF]
P. Paramasivam, C. Ramachandra Raja
Journal of Crystallization Process and Technology (JCPT) , 2012, DOI: 10.4236/jcpt.2012.21004
Abstract: In this analysis, the single crystal of L-Proline Succinate (LPS) has been successfully synthesized and the purity of ma- terial has been increased by repeated recrystallization process. Single crystal was grown by adopting the method of growing in a slow evaporation solution using water as solvent at room temperature. The LPS single crystal has been synthesized by taking equimolar quantity of L-Proline and succinic acid, by mixing them thoroughly using deionized water. The prepared concentrated solution was placed in an undisturbed condition, and the solution was inspected regu- larly. The single crystal has been harvested over a period of 1 month. The same crystal was characterized by different techniques for finding its suitability for device fabrications. The grown crystal was characterized by Single crystal XRD, Powder XRD, FTIR, UV-vis-NIR, DTA/TGA and SHG analyses, respectively. The observed results from various char- acterization show the suitability for NLO application. The second harmonic generation of this grown crystal was checked using Kurtz Perry technique which showed positive results. The UV cut-off wavelength and the decomposition temperature of this grown crystal were found to be good when compared with the existing organic crystals.
The Context of Knowledge and Data Discovery in Highly Dense Data Points Using Heuristic Approach  [PDF]
C. S. Sasireka, P. Raviraj
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.41011

In data mining framework, for proficient data examination recent researchers utilized branch-and-bound methods such as seriation, clustering, and feature selection. Conventional cluster search was completed with diverse partitioning schemes to optimize the cluster pattern. Considering image data, partitioning approaches seems to be computationally complex due to large data size, and uncertainty of number of clusters. Recent work presented a new version of branch and bound model called model selection problem, handles the clustering issues more efficiently. The existing work deployed spatially coherent sampling for generating cluster parameter candidates. But if the problem-specific bounds and/or added heuristics in the data points of the domain area get surmounted, memory overheads, specific model selection, and uncertain data points cause various clustering abnormalities. To overcome the above mentioned issues, we plan to present an Optimal Model-Selection Clustering for image data point analysis in the context of knowledge and data discovery in highly dense data points with more uncertainty. In this work, we are going to analyze the model selection clustering which is first initiated through the process of heuristic training sequences on image data points and appropriates the problem-specific characteristics. Heuristic training sequences will generate and test a set of models to determine whether the model is matched with the characteristics of the problem or not. Through the process of heuristic training sequences, we efficiently perform the model selection criteria. An experimental evaluation is conducted on the proposed model selection clustering for image data point using heuristic approach (MSCHA) with real and synthetic data sets extracted from research repositories (UCI) and performance of the proposed MSCHA is measured in terms of Data point density, Model-Selection Criteria, Cluster validity.

A Novel Asymmetrical Single-Phase Multilevel Inverter Suitable for Hybrid Renewable Energy Sources  [PDF]
C. P. Boopathy, M. Kaliamoorthy
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.76079
Abstract: This paper introduces a novel single-phase asymmetrical multilevel inverter suitable for hybrid renewable energy sources. The proposed inverter consists of two isolated DC sources and six power semiconductor controlled switches. The suggested inverter is capable of generating seven-level output when the input DC voltage is taken in the ratio of 1:2. The higher magnitude DC source is fed from Photo Voltaic (PV) panels, whereas the lower magnitude DC source is fed from Wind Turbine (WT) driven Permanent Magnet DC (PMDC) generator. Both the renewable energy sources are connected to the inverter via two DC-DC boost converters connected in cascade (i.e.one for maximum power point tracking and another for DC-link voltage control). The proposed hybrid renewable energy source inverter is connected to single-phase grid via proper control systems. The complete system is simulated using MATLAB/SIMULINK and the results are presented in detail.
Skinner, Quentin, Liberty before Liberalism (Cambridge, 1999), 142 pags
P. C.
Revista de estudios histórico-jurídicos , 2000,
Miethke, J., De potestate Papae. Die p pstliche Amtskompetenz im Widerstreit der politischen Theorie von Thomas von Aquin bis Wilhelm von Ockham (München, 2000), 357 págs
P. C.
Revista de estudios histórico-jurídicos , 2000,
Hüglin, Th., Early Modern Concepts for a Late Modern Wordl. Althusius on Community and Federalism (Ontario, Wilfrid Laurier University Press, 1999)
P. C.
Revista de estudios histórico-jurídicos , 2000,
Page 1 /374321
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.