Search results for "electricity"
showing 10 items of 1225 documents
Plaque removal efficacy of power and manual toothbrushes: a comparative study
2009
The aim of this study was to compare the plaque removal efficacy of a new oscillating/rotating/pulsating toothbrush [Oral-B® Professional Care® 8500 (PC 8500)] with two manual toothbrushes [Oral-B® CrossAction™ Vitalizer (CAV) and Oral-B® Indicator™ (IND), respectively]. The safety of the PC 8500 was also assessed. The study was a single-use, observer-masked, randomised 3×3 Latin square crossover design balanced for carryover effects. The enrolled subjects (n=66) refrained from brushing for 23–25 h before each clinical examination. Plaque scores were recorded before and after brushing with the allocated toothbrush using the Turesky et al. modification of the Quigley and Hein plaque index. T…
Evidence of noncentrosymmetry of human tooth hydroxyapatite crystals
2014
Herein, we investigate human single hydroxyapatite crystals (enamel and dentine) by convergent-beam electron diffraction (CBED) and automated electron-diffraction tomography (ADT). The CBED pattern shows the absence of the mirror plane perpendicular to the c axis leading to the P63 space group instead of the P63 /m space group considered for larger-scale crystals, this is confirmed by ADT. This experimental evidence is of prime importance for understanding the morphogenesis and the architectural organization of calcified tissues.
Automatic SCSB analysis of motor and autonomic nervous functions compared with sleep stages
1996
All-night recordings of respiration, ballistocardiogram, and body movements were obtained using the static charge-sensitive bed (SCSB) and automatically analysed data were compared with sleep stages. The mean sum of eight SCSB variability parameters was lowest in slow wave sleep (SWS), higher during stage 2 (S2), and highest in REM sleep. The sum scores of the parameters with the highest correlations with the EEG data were classified into quiet (QS), intermediate (IS) and active (AS) states. SCSB signals during wakefulness, stage 1 and REM sleep were mostly scored as AS, whereas in S2 and especially in SWS they were scored as QS or IS. The SCSB is an easy and inexpensive tool for conducting…
Force control and powder dispersibility of spray dried particles for inhalation
2009
This study aims towards a deeper understanding of the correlation between particle morphology, cohesion forces, and aerosol performance of spray dried powders for inhalation. Therefore, forces affecting cohesion and dispersion are consid- ered and some novel contact models are introduced to explain the improved powder dispersibility of corrugated particles. Particles with different degrees of corrugation are prepared by spray drying and characterized. Powder dispersibility is measured by positioning a dry powder inhaler in front of the laser diffraction device. The particle sizes of all powders are in the range of x50 ¼ 2.11 � 0.15 mm. The ratio of mass specific surface area Sm to volume sp…
Comparative analysis of acoustic emission signals generated by electrical discharges measured by the hydrophone and the wideband contact transducer
2005
The paper presents a comparative analysis of the acoustic emission (AE) pulses and signals generated by PDs. For this purpose the measurements of the acoustic emission signals generated by PDs were taken in the multipoint-plane system using a hydrophone placed directly in the area of discharge generation, and the AE pulses using a piezoelectric contact transducer which was on a side wall of a power transformer tub. Next, time runs and amplitude density spectra were drawn. Also the descriptors describing signals in the frequency domain were determined and the time-frequency analysis was carried out, which determined spectrograms for the energy density spectrum.
Observation of interaction forces by investigation of the influence of eluent additives on the retention behavior of aqueous nanoparticle dispersions…
2020
The investigation and subsequent understanding of the interactions of nanomaterials with components of their surrounding media is important to be able to evaluate both potential use cases as well as potential risks for human health and for the environment. To investigate such interactions, asymmetrical flow field-flow fractionation (AF4) is an interesting analytical tool. This statement grounds on the fact that interactions of the analyte with the membrane and with components of the eluent are crucial for the retention behavior of the analyte within the field-flow fractionation (FFF) channel. Therefore, the investigation of the retention behavior provides an insight in the nature of the int…
Towards a microbial thermoelectric cell.
2013
Microbial growth is an exothermic process. Biotechnological industries produce large amounts of heat, usually considered an undesirable by-product. In this work, we report the construction and characterization of the first microbial thermoelectric cell (MTC), in which the metabolic heat produced by a thermally insulated microbial culture is partially converted into electricity through a thermoelectric device optimized for low ΔT values. A temperature of 41°C and net electric voltage of around 250–600 mV was achieved with 1.7 L baker’s yeast culture. This is the first time microbial metabolic energy has been converted into electricity with an ad hoc thermoelectric device. These results might…
Temperature dependence of the non-local spin Seebeck effect in YIG/Pt nanostructures
2017
We study the transport of thermally excited non-equilibrium magnons through the ferrimagnetic insulator YIG using two electrically isolated Pt strips as injector and detector. The diffusing magnons induce a non-local inverse spin Hall voltage in the detector corresponding to the so-called non-local spin Seebeck effect (SSE). We measure the non-local SSE as a function of temperature and strip separation. In experiments at room temperature we observe a sign change of the non-local SSE voltage at a characteristic strip separation d0, in agreement with previous investigations. At lower temperatures however, we find a strong temperature dependence of d0. This suggests that both the angular momen…
Polyfunctional recognition of pyridinedicarboxylate anions with macrocyclic polyamine receptors containing heteroaromatic groups.
2008
The interaction of the biologically relevant anions deriving from the six pyridinedicarboxylic acids (H2PDC) with two macrocyclic receptors containing a pentamine chain and a bipyridine (1) or a phenanthroline (2) moiety, as well as with the aliphatic analogue [21]aneN7 (3), was studied by means of spectroscopic methods (UV-vis, NMR) and potentiometric titrations affording the stability constants of the adducts formed. All three receptors form stable complexes with the substrates thanks to the formation of several salt bridges and hydrogen bond contacts, as observed in the crystal structure of the H8[3(2,6-PDC)4] x H2O x 0.5 EtOH solid compound. Additional pi-stacking interactions between t…
Comparative analysis of the electrostatics of the binding of cationic proteins to vesicles: Asymmetric location of anionic phospholipids
2009
The role of electrostatics is studied in the adsorption of cationic proteins to zwitterionic phosphatidylcholine (PC) and anionic PC/phosphatidylglycerol (PG) mixed small unilamellarvesicles (SUVs). For model proteins the interaction is monitored vs. PG content at low ionic strength. The adsorption of lysozyme and myoglobin (isoelectric point, pl 7-11) is investigated in SUVs, along with changes of the fluorescence emission spectra of the cationic proteins, via their adsorption on SUVs. In the Gouy-Chapman formalism, the activity coefficient goes with the square of charge number. Deviations from the ideal model could indicate the asymmetric location of the anionic phospholipid in the bilaye…