Search results for "sensor"
showing 10 items of 4594 documents
Use of electronic nose to determine defect percentage in oils. Comparison with sensory panel results
2010
Abstract An electronic nose based on an array of 6 metal oxide semiconductor sensors was used, jointly with linear discriminant analysis (LDA) and artificial neural network (ANN) method, to classify oils containing the five typical virgin olive oil (VOO) sensory defects (fusty, mouldy, muddy, rancid and winey). For this purpose, these defects, available as single standards of the International Olive Council, were added to refined sunflower oil. According to the LDA models and the ANN method, the defected samples were correctly classified. On the other hand, the electronic nose data was used to predict the defect percentage added to sunflower oil using multiple linear regression models. All …
Influence of flavour transfer between different gel phases on perceived aroma
2007
International audience; Multiphasic models of stirred fruit yoghurts made from a bilayer that consisted of a pectin and a dairy gel were developed in order to study the transfer of strawberry flavour compounds between the two phases. Several parameters (i.e., the flavour concentration, the fat content of the dairy gel and the storage temperature) affecting flavour compound transfer, using an experimental design, together with their effect on sensory perception were investigated. Strawberry flavour transfer between the two gels was high enough to affect the sensory perception of the dairy gels. The parameters that modified the partitioning of ethyl esters between the pectin and dairy gel (i.…
Ftalocyjaniny – potęga możliwości
2015
Od momentu odkrycia ftalocyjaniny cieszą się ogromnym zainteresowaniem. Przypadkowe odkrycie w 1928 roku na terenie szkockiej fabryki, wywołało lawinę pytań odnośnie ich struktury i możliwości jej modyfikacji. Jak dotąd otrzymano kilkadziesiąt pochodnych ftalocyjanin, różniących się właściwościami i mogących znaleźć zastosowanie w różnych dziedzinach życia. Właściwości spektralne, które tłumaczą intensywną barwę roztworów ftalocyjanin, decydują o możliwości wykorzystywania tych związków jako barwników. Natomiast interesujące właściwości związane z transferem energii zostały wykorzystane w medycynie do leczenia nowotworów jako fotosensybilizatory w fotodynamicznej terapii – PDT. Rośnie równi…
Tailoring the excitation of fundamental flexural guide waves in coated bone by phase-delayed array: Two-dimensional simulations
2015
The fundamental flexural guided wave (FFGW) enables ultrasonic assessment of cortical bone thickness. In vivo, it is challenging to detect this mode, as its power ratio with respect to disturbing ultrasound is reduced by soft tissue covering the bone. A phase-delayed ultrasound source is proposed to tailor the FFGW excitation in order to improve its power ratio. This situation is analyzed by 2D finite-element simulations. The soft tissue coating (7-mm thick) was simulated as a fluid covering an elastic plate (bone, 2–6 mm thick). A six-element array of emitters on top of the coating was excited by 50-kHz tone bursts so that each emitter was appropriately delayed from the previous one. Respo…
Spēles uz gaismas galda kā vārdu krājuma paplašināšanas līdzeklis 3-4 gadus veciem bērniem ar valodas attīstības aizturi
2021
Diplomdarba tēma “Spēles uz gaismas galda kā vārdu krājuma paplašināšanas līdzeklis 3 – 4 gadus veciem bērniem ar valodas attīstības aizturi”. Diplomdarba autore Ieva Maļinovska. Darbā apkopotas teorētiskās nostādnes par 3 – 4 gadīgo bērnu attīstības īpatnībām un izpausmēm, kā arī gaismas galda izmantošanas iespējām vārdu krājuma paplašināšanā. Teorētiskās atziņas tiek analizētas, lai rastu jaunu veidu, kā izmantot sensoros materiālus uz gaismas galda un izstrādātu metodes bērnu vārdu krājuma pilnveidei, kas bērniem šķistu aizraujošas un neapniktu. Lai pārbaudītu diplomdarba hipotēzi “Spēļu uz gaismas galda izmantošana vārdu krājuma pilnveidē 3 – 4 gadus veciem bērniem ar valodas attīstības…
Sensoru izelpas analizatora pielietojums kuņģa vēža diagnostikā
2021
Ievads. Kuņģa vēzis ir viens no biežāk sastopamajiem un viens no nāvējošākajiem audzējiem pasaulē. Lai nodrošinātu veiksmīgu ārstēšanu, ir svarīgi kuņģa vēzi diagnosticēt agrīnās stadijās. Daudzsološa un neinvazīva kuņģa vēža skrīninga metode ir izelpas analīze, kas balstās uz gaistošo organisko savienojumu (GOS) noteikšanu izelpā, pielietojot sensorus. Darba mērķis. Izvērtēt sensoru izelpas analizatora spēju diferencēt kuņģa vēža pacientus un indivīdus bez vēža. Materiāli un metodes. Pētījumā tika iekļauti kuņģa vēža pacienti un indivīdi bez kuņģa vēža, kuri fiziski spēja ziedot savas izelpas paraugu. Izelpa tika veikta sensoru izelpas analizatorā, kurš saturēja divu veidu sensorus – astoņ…
Gap junction intercellular communication (GJIC) is regulated by plasmalogens in retinal macroglial cells
2019
International audience
Humidity-enhanced sub-ppm sensitivity to ammonia of covalently functionalized single-wall carbon nanotube bundle layers
2017
International audience; A low-cost method for carbon nanotubes (CNTs) network production from solutions on flexible polyethylene naphthalate substrates has been adopted to prepare high quality and well characterized SWCNT bundle layers to be used as the active layer in chemiresistor gas sensors. Two types of SWCNTs have been tested: pristine SWCNTs, deposited from a surfactant solution, and covalently functionalized SWCNTs, deposited from a dimethyl-acetamide solution. The humidity effects on the sensitivity of the SWCNTs network to NH3 have been investigated. The results show that relative humidity favors the response to NH3, confirming recent theoretical predictions. The COOH-functionaliz…
Microwave gas sensor based on graphene aerogel for breath analysis
2022
Exhaled breath can be used for early detection and diagnosis of diseases, monitoring metabolic activity, and precision medicine. In this work, we design and simulate a microwave sensor in which thin graphene aerogels are integrated into rectangular microwave waveguides. Graphene aerogels are ideal sensing platforms for gases and volatile compounds as they combine extremely high surface-to-volume ratio and good electrical conductivity at RF and microwave frequencies. The latter is modified by exposure to different gases, and -when integrated into a waveguide- these changes result in significant shifts in transmission and reflection scattering parameters. We model the aerogel as a graphene gr…
Quantum Mechanical Co-Adsorption Modelling of Real Electrically Controlled Semiconductor Gas Sensors
2009
Abstract Co-adsorption of several gases is still a challenge due to the variety of reaction paths at the sensitive surface, and their competition for the adsorption sites. With an extended Wolkenstein model and the gas kinetic theory, we find that for specific paths their sequence of exposition has an important influence on the layer resistance as well as on the time required to achieve equilibrium. Whilst only processes that involve charge transfer can be electrically detected, a good correlation between model and electrical measurements needs weakly chemisorbed (physisorbed) layers to be taken in account. Our study presents a SnO2 nano-film sensor with electrical control electrodes expose…