67 research outputs found
Ethical issues in monitoring and based tracking systems
Monitoring and based tracking systems use a variety of
technologies to record and monitor the activities of humans. This can increase the risks to the privacy and security of individuals. The amount of information gathered about individuals is growing through the proliferation of surveillance cameras, sensors; microchips and Radio Frequency Identification RFID tags embedded in devices and products. Advances in electronic technologies allow companies and government agencies to store and process large amounts of information about individuals. The
Internet provides the ultimate copier device, making this
information easily available to millions. This paper highlights the ethical issues emerging with the new technologies in the monitoring and base tracking system. New regulations should be proposed to protect the individual privacy
Development of an empirical dust storm attenuation prediction model for microwave links in arid area – a proposed framework
Wireless communication service providers are currently facing challenges due to the congested frequencies spectrum which has imposed the use of higher and higher frequencies. However, higher frequency bands are more sensitive to weather condition and the microwave signal attenuation due to atmospheric particles increases rapidly at higher frequency bands. Consequently dust storms and other phenomena cause signal attenuation which can limit the performance of wireless communication systems for the frequencies above 10GHz in arid area. The paper aim is to show that real dust storm is a complex phenomena which is difficult to be described by the theoretical physical or mathematical models. An empirical dust storm prediction model based on the long term statistical observations of dust storm properties and its corresponding microwave signal levels will be a step forward to provide microwave link designers with a precise tool to rely on. This paper has proposed a research framework to collect necessary data from Khartoum, Sudan and develop an empirical attenuation prediction model
Mal de pott révelé par un abcès latéropharyngien chez un pilote
Introduction: Pott's disease is the most frequent localisation of osteoarticular tuberculosis. The authors report a case of cervical Pott's disease with lateropharyngeal abscess.Observation: Our patient is a 44 years old pilot; he presented since 6 months cervicalgy, dysphagia and weighting loss. Clinical findings showed a swelling of posterior and lateral oropharyngeal wall extending to hypopharynx. A palsy of the XI th nerve and an abolition of the bicipital reflex were also noticed. CT scan showed a lateropharyngeal collection extending from C4 to D1. It was also noticed a subtotal destruction of C6.However, there were no medullar lesions in the cervical spine MRI.Tuberculosis was confirmed thanks to histological analysis of caseum taken during cervical biopy. The patient was operated using anterior approach. He had surgical removal of C6 which was replaced by iliac prothesis. Medical treatment was based on antituberculosis drugs used during 12 months. After three years of follow up, the out come was favourable with no recurrence and satisfying consolidation. For aeronautic considerations, the patient was declared unable for flying mission.Conclusion: Tuberculosis constitutes a problematic infectious disease in Tunisia which may have serious consequences on publish health. We insist on preventing measurements because there are neither specific clinical findings nor radiological characterising features.Keywords: Tuberculosis, Pott's disease, lateropharyngeal absces
Wood Flour Modified by Poly(furfuryl alcohol) as a Filler in Rigid Polyurethane Foams: Effect on Water Uptake
The use of lignocellulosic fillers in rigid polyurethane foams (RPUFs) has been receiving great attention due to their good mechanical and insulation properties and the high sustainable appeal of the obtained cellular polymers, although high water uptakes are found in most of these systems. To mitigate this detrimental effect, RPUFs filled with wood flour (2.5% wt) were fabricated with the addition of furfuryl alcohol (FA) to create a polymer grafted with the wood filler. Two concentrations of FA (10 wt% and 15 wt%) were investigated in relation to the wood flour, and the RPUFs were characterized for cell morphology, density, compressive properties, thermal stability, and water uptake. The introduction of wood flour as a filler decreased the cell size and increased the anisotropy index of the RPUFs and, in addition to that, the FA grafting increased these effects even more. In general, there were no significant changes in both mechanical and thermal properties ascribed to the incorporation of the fillers. On the other hand, a reduction of up to 200% in water uptake was ascribed to the FA-treated fillers.This work was supported by the Coordination for the Improvement of Higher Education—CAPES (code 001), the National Council for Scientific and Technological Development—CNPq (Financial code 301758/2019-0) and the University of Basque Country (COLAB20/04)
Air born dust particles effects on microwave propagation in arid-area
Dust storms can degrade visibility and increase
atmospheric attenuation. Therefore, microwave (MW)
propagation is severely affected by dust storms in many parts
of the world. Air-born dust particles may affect
electromagnetic waves during a dust storm. In this paper air-
born dust particles effects are studied based on measured
visibility. Recent analytical and numerical models results are
compared to the measured at 14 GHz. Consequently,
measured attenuation is significantly greater than the
predicted using recent analytical and numerical models. Dust storms can degrade visibility and increase
atmospheric attenuation. Therefore, microwave (MW)
propagation is severely affected by dust storms in many parts
of the world. Air-born dust particles may affect
electromagnetic waves during a dust storm. In this paper air-
born dust particles effects are studied based on measured
visibility. Recent analytical and numerical models results are
compared to the measured at 14 GHz. Consequently,
measured attenuation is significantly greater than the
predicted using recent analytical and numerical models
Nanofibrillated Cellulose-Based Aerogels Functionalized with Tajuva (Maclura tinctoria) Heartwood Extract
Aerogels are 3-D nanostructures of non-fluid colloidal interconnected porous networks consisting of loosely packed bonded particles that are expanded throughout their volume by gas and exhibit ultra-low density and high specific surface area. Cellulose-based aerogels can be obtained from hydrogels through a drying process, replacing the solvent (water) with air and keeping the pristine three-dimensional arrangement. In this work, hybrid cellulose-based aerogels were produced and their potential for use as dressings was assessed. Nanofibrilated cellulose (NFC) hydrogels were produced by a co-grinding process in a stone micronizer using a kraft cellulosic pulp and a phenolic extract from Maclura tinctoria (Tajuva) heartwood. NFC-based aerogels were produced by freeze followed by lyophilization, in a way that the Tajuva extract acted as a functionalizing agent. The obtained aerogels showed high porosity (ranging from 97% to 99%) and low density (ranging from 0.025 to 0.040 g·cm−3), as well a typical network and sheet-like structure with 100 to 300 μm pores, which yielded compressive strengths ranging from 60 to 340 kPa. The reached antibacterial and antioxidant activities, percentage of inhibitions and water uptakes suggest that the aerogels can be used as fluid absorbers. Additionally, the immobilization of the Tajuva extract indicates the potential for dentistry applications.The APC was funded by University of the Basque Country. CAPES (Coordination for the Improvement of Higher Education Personnel) for the doctoral scholarship of the first author
Signature recognition using artificial neural network
Nowadays, there are many applications required the user to confirm his identity. It might be done by asking a secret question that the user will answer to get into that application, and it might be a password or a pin code, face, eye, fingerprint or signature. Automatic signature
verification is an active field of research with many practical applications. Automatic handwritten signature verification is divided into two approaches: off-line and on-line. In the off-line signature verification approach, the data of the signature is obtained from a static
image utilizing a scanning device [I). For our application, off-line approach will be utilized.Neural Networks (NN) also known as Artificial Neural Networks (ANN) belong to the
artificial intelligence approaches, which attempt to mechanize the recognition procedure according to the way a person applies intelligence in visualizing and analyzing[2]. Neural Networks' structure is inspired by biological models of the nervous system proposed as a model of the human brain's activities aiming to mimic certain processing capabilities of the human brain
2.45 GHz passive RFID tag antenna mounting on various platforms
This paper presents the design of a passive RFID tag antenna operating at 2.45 GHz. The electromagnetic simulation software called CST is used for design and simulation. A high gain (5.842dB), a good impedance matching with the microchip (-30.0 dB Return Loss) and a satisfactory read range performance (upto 5 m) was obtained. One approach of designing RFID tag is that the tag should be less sensitive to the various types of objects. The effects of obstacles on antenna’s characteristics have been investigated by placing the tag antenna against a metallic, rubber, glass and wood surfaces. Simulation results show slight variations which is within tolerance range.
Key words: RFID, Tag Antenna, CS
Wood under fresh water: Effect on the chemical properties and on decay resistance
This study aimed to evaluate the effect of waterlogging on the chemical properties and on decay resistance of two fast-growing eucalypt species. Samples of spotted gum and rose gum wood were placed underwater and taken out at different times: after 4, 8 and 12 months. Chemical properties were performed via wet chemical quantification (Tappi standards), monomeric sugars by HPLC, and qualitative evaluation of extractives by Py-GC/MS and ATR-IR spectroscopy; biological performance was investigated using Trametes versicolor and Gloeophyllum trabeum rot fungi. The results showed slight changes to the chemical properties of both wood species, with an increase in lignin represented by the reduction of sugars due to waterlogging. Both species showed higher susceptibility to Gloeophyllum trabeum mainly in the sapwood, with no influence on decay resistance due the waterlogging
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