Search results for "CONSTRUCTION"
showing 10 items of 2670 documents
Condition Assessment and Analysis of Bearing of Doubly Fed Wind Turbines Using Machine Learning Technique
2023
Condition monitoring of wind turbines is progressively increasing to maintain the continuity of clean energy supply to power grids. This issue is of great importance since it prevents wind turbines from failing and overheating, as most wind turbines with doubly fed induction generators (DFIG) are overheated due to faults in generator bearings. Bearing fault detection has become a main topic targeting the optimum operation, unscheduled downtime, and maintenance cost of turbine generators. Wind turbines are equipped with condition monitoring devices. However, effective and reliable fault detection still faces significant difficulties. As the majority of health monitoring techniques are primar…
Seismic analysis and risk mitigation of existing constructions
2016
Following a thorough and lengthy procedure, we would like to thank all contributors for their highest calibre papers, which comprise the Special Issue on “Seismic analysis and risk mitigation of existing constructions” of the Open Construction and Building Technology Journal. The topic of the Special Issue encompasses a large number of issues spanning the design of special interventions for the reduction of the effects of earthquakes on civil structures and infrastructures, to the structural identification and assessment issues. The field of seismic engineering is continuously looking for new strategies and methods, which empower the designers and make them able to obtain more accurate resp…
AX-PET: A novel PET detector concept with full 3D reconstruction
2009
We describe the concept and first experimental tests of a novel 3D axial Positron Emission Tomography (PET) geometry. It allows for a new way of measuring the interaction point in the detector with very high precision. It is based on a matrix of long Lutetium-Yttrium OxyorthoSilicate (LYSO) crystals oriented in the axial direction, each coupled to one Geiger Mode Avalanche Photodiode (G-APD) array. To derive the axial coordinate, Wave Length Shifter (WLS) strips are mounted orthogonally and interleaved between the crystals. The light from the WLS strips is read by custom-made G-APDs. The weighted mean of the signals in the WLS strips has proven to give very precise axial resolution. The ach…
Design of a safety training package for migrant workers in the construction industry
2021
Abstract The construction sector is known as a high-risk sector with many safety challenges. It is also characterised by a large number of migrant workers and these workers report higher accident rates than native workers. This paper presents the design of the CSTP (Construction Safety Training Programme). The CSTP is a theory-based training program aimed at improving safety behaviours in construction sites acknowledging the particular challenges migrant workers face. Based on second and third generational models of training, we developed a training program that addresses the challenges faced by migrant workers in the construction industry, namely language and cultural barriers, times press…
Efficacy of chlorhexidine, hydrogen peroxide and tulsi extract mouthwash in reducing halitosis using spectrophotometric analysis : a randomized contr…
2019
Background To evaluate the efficacy of tulsi extract mouthrinse in reducing halitosis as compared to chlorhexidine and hydrogen peroxide mouthrinses using spectrophotometric analysis. Material and methods It was a parallel, single center, double blinded randomized controlled trial of 15 days duration. A total of 300 participants were screened, out of which 45 subjects those fulfilled inclusion criteria of age range 17-35 years were included in the trial. The participants were randomly provided with tulsi, hydrogen peroxide or chlorhexidine mouthwashes (control group) to use 10 ml twice daily for 15 days. Clinical measurements were taken at baseline and 15 days using arbitrary 0-5 scale for …
3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro
2012
We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-ba…
Development of the Mental Imagery Scale for Preschool Children using Classical Test Theory and Item Response Theory
2020
This study aimed to develop a measure of mental imagery evaluation in preschool children. Three studies were conducted: Study 1 focused on the exploration of the factorial structure, reliability, and Item Response Theory (IRT) discrimination on a sample of children from 4 to 5 years old (N = 100; 50% males and 50% females); Study 2 focused on the confirmation of results about dimensionality on a sample of children from 4 to 7 years old (N = 170; 50% males and 50% females); and Study 3 focused on verifying criterion validity on a sample of children from 4 to 5 years old (N = 70; 47.1% males and 52.9% females). The results confirmed the hypothesis of three reliable factors underlying the scal…
Selective Actuation and Tomographic Imaging of Swarming Magnetite Nanoparticles
2021
International audience; Micro- and nanomotors have seen substantial progress in recent years for biomedical applications. However, three grand challenges remain: (i) high velocities to overcome the blood flow, (ii) spatially selective control to enable complex navigation, and (iii) integration of a medical, tomographic real-time imaging method to acquire feedback information. Here, we report the combination of active magnetic matter and a medical imaging technique, namely magnetic particle imaging (MPI), which addresses these needs. We synthesize ∼200 nm magnetic nanoparticles and observe a macroscopic, collective effect in a homogeneous magnetic field with a rotating field vector. The nano…
Compressive imaging in scattering media.
2015
One challenge that has long held the attention of scientists is that of clearly seeing objects hidden by turbid media, as smoke, fog or biological tissue, which has major implications in fields such as remote sensing or early diagnosis of diseases. Here, we combine structured incoherent illumination and bucket detection for imaging an absorbing object completely embedded in a scattering medium. A sequence of low-intensity microstructured light patterns is launched onto the object, whose image is accurately reconstructed through the light fluctuations measured by a single-pixel detector. Our technique is noninvasive, does not require coherent sources, raster scanning nor time-gated detection…
The overall classification of residential buildings: Possible role of tourist EU Ecolabel award scheme
2012
Abstract The debate on the environmental performance of buildings and their classification is continuously rising and deeply involves all actors of the sector, from researchers to technicians and from owners to real estate managers. In the field, the EU has created a panel that is currently working on defining the criteria for attributing an Ecolabel award to a building. However, despite the enormous efforts made by administrative and academic institutions, a suitable and widely available scheme for operators to assess the environmental performance of a building is far from being established. To help provide a solution to the problem, the possibility of adopting the EU Ecolabel scheme estab…