Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bioelectric Energy Sources”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed1975

[Interindividual variability and intraindividual reaction stability of bioelectric muscular tension of the long finger flexor in model exercise].

Twelve untrained subjects had to perform opening and closing movements of the hand (2 mm-sec(-1) on a hand ergometer. The load was 2kp for woman and 5 kp for man. Two sequences of the test were carried out, one after the other. The EMG was derived unipolarly from the belly of the Mm. flex. digit, and the mean bioelectrical muscle activity was measured. The following factors were tested in each subject by means of an analysis of variance. Factor A -- phase of exercise, Factor B --repetition of exercise and Factor C -- type of sequence. The analysis of the stability of individual reactions was made through serial correlations. Factor A influenced the mean bioelectrical muscle activity in all subjects while Factors B and C had an influence only in some cases. A significant interaction effect between pairs of factors occurred only in a few subjects. The serial correlation coefficients for Factor A of the same composition is between 0.40 and 0.80. The values of the mean correlation functions for the two sequences of Factor C, C(I) and C(II), are 0.69 and 0.68 respectively. In each subject the range of the cross correlation coefficients of the sequences C(I) and C(II) was between 0.70 and 0.92. Possible causes for the varying experimental results were discussed.

Adult↗
PubMed2002

High torque ultrasonic motors for hand prosthetics: current status and trends.

This paper presents the work carried out at the Instituto de Automática Industrial, in the framework of the EU MANUS project and with the co-operation of the Katholieke Universiteit of Leuven, to develop a specifically designed TWUM for driving our prototype of hand prosthesis. The application of TWUM to prosthetic devices has clear advanteges, namely, noiseless operation, self-braking drive, high torque and low speed characteristics. Here we analyse main actuation advantages, point out main drawbacks of this technology and describe our research in the area of specific design of TWUM for high torque actuation, improved control characteristics and enhanced overall performance. We intend to provide a concurrent approach to the overall actuator design involving electronics, mechanical design as well as improved control strategies having in mind the prosthetic application.

Artificial Limbs↗
PubMed1975

Technological progress in pacemaker design: hermetic sealing.

Clinical statistics covering the life of pacemakers powered by mercury batteries show that an average life of 3 years has not yet been obtained. Strangely, the life does not seem to depend on the current consumed by the pacemaker, whether of the demand or asynchronous type. A study of the behavior of 229 mercury batteries discharged in a dry atmosphere showed that 92% of the batteries were still functioning after 54-57 months. It is deduced that pacemaker life is shortened by the infiltration of moisture into the batteries when molded in an epoxy. - A technology for the hermetic encapsulation of a pacemaker is described. This technology is applied to both mercury and lithium batteries. The results obtained with 5835 instruments over periods of up to 36 months.

Biocompatible Materials↗
PubMedDate not supplied

[Apparatus for cardiosynchronized artificial circulation].

The development of outfits for ancillary circulation is oriented towards improvement and construction of new pneumatic, hydraulic and electromechanical actuating systems--units intended for an optimal disposition of pressure waves moving from the pump to the aorta, etc. An inference is drawn about advantages and perspectives offered by functionally monitored actuating units, as well as about the need for the pulsating stream to pass through the low-power side intended to pre-set the shape of the pressure curve.

Austria↗
PubMed2002

Effects of volatile fatty acids on a thermophilic anaerobic hydrogen fermentation process degrading peptone.

Hydrogen fermentation using glucose as a single substrate caused abrupt pH drops and the gradual losses of hydrogen producers, which in turn led to system failure. In this study the use of a proteinaceous substrate, peptone, avoided the abrupt pH drops in the reactive system and allowed for further exploration of volatile fatty acids (VFAs) and pH effects on the hydrogen fermentation process. Our results showed that: (1) during the hydrogen fermentation tests, the abrupt pH drops were avoided thus system stability increased due to the production of ammonia from the peptone fermented, (2) pH control was not necessary and the addition of acetate to the process had little effect on the hydrogen fermentation process, (3) at the extreme pHs the addition of acetate either lengthened the lag phase (pH < or = 6) or slowed the hydrogen production rate (pH > or = 8), and both situations were not desired, and (4) high VFA content in the system sped up the consumption of hydrogen gas. Results of this study suggested that the hydrogen fermentation using the protein-containing substances as substrate was beneficial in maintaining the system pH. As long as the pH was maintained around 6-8, system inhibition due to VFAs accumulation was minimized. Thus, the optimal operation of a hydrogen fermentation process would be achievable via the control of substrate composition at a certain carbohydrate-to-protein ratio.

Bioelectric Energy Sources↗
PubMed2002

Utilisation of energy from digester gas and sludge incineration at Hamburg's Köhlbrandhöft WWTP.

At Hamburg's Köhlbrandhöft WWTP the demand for external energy supply is minimised by state of the art sludge treatment. The sludge is subjected to thickening, anaerobic digestion, dewatering, drying and incineration. The digester gas is used in a combined gas and steam turbine process. The sludge incineration also produces steam, which is also used in the steam turbine that follows the gas turbine. The turbines produce electricity, partially expanded steam is used for the sludge drying process. Heat from the condensation of vapours from sludge drying is used to heat the anaerobic digesters. The overall process requires no external heat or fuel and produces 60% of the WWTP's electricity demand.

Bacteria, Anaerobic↗
PubMed2002

Sustainability of thermal oxidation processes: strengths for the new millennium.

Incineration of sludge is occasionally accused of pollution. This paper shows that if it is correctly designed and implemented, it can be environmentally friendly. For this purpose, sludge incineration is compared to agricultural spreading of limed sludge with respect to toxicity criteria, greenhouse effect gases (GEG) release, energy wasting and other environmental parameters. Landfilling is also considered but as a standby route. Since present regulations on agricultural use and gas emission release from incinerators are stringent, incineration cannot be suspected to release more noxious substances in the environment than agriculture. A distinction is made between biogenic CO2 and fossil CO2. Nevertheless case studies show that incineration produces more GEG and wastes more energy than agricultural spreading if no energy is recovered from hot flue gas. In the case of thermal power or electrical power generation, the environmental balance becomes dramatically more favorable for incineration.

Agriculture↗
PubMed2002

[The problem of developing a lettuce greenhouse for the International space station and future interplanetary missions].

In order to evaluate the effects of gravity on growing plants, we conducted ground-based long-term experiments with dwarf wheat (cultivar "Apogee USU") and Chinese cabbage (cultivar "Khibinskaja"). The test crop had been grown in overhead position with HPS lamp below the root module so that gravity and light gradients were in opposite direction. Plants of the control crop grew in normal position under the same lamp. Both crops were grown on porous metallic membranes with stable--1 kPa water potential on the surface. Results from these studies allowed us to examine the significant differences in growth and development of the plants as well as the root systems in relation to the gravity force. Nevertheless, the experiments in greenhouse Svet aboard the Mir space station proved that it is possible to compensate the effects of weightlessness on higher plants by manipulating gradients of environmental parameters (i.e. photon flux, water potential in the root zone, etc.). Even in ground studies Svet productivity averaged no more than 14 gm of fresh salad biomass per a day. This does not provide a sufficient supplement nutrients to the ISS crew. A cylindrical design of a space plant growth facility (SPGF) allows for maximal productivity under very tight energy and volume limitations onboard the ISS and a number of operational advantages.

Bioelectric Energy Sources↗
PubMed2003

Study on an environmental-friendly and high-efficient fuel cell energy conversion system.

The kinds and the distribution of the coal in China are investigated. The results indicated that the 80% coal in China is used by the method of the coal gasification. The possibility of utilization and development of the fuel cell power plant in China is analyzed. A combined cycle generation system is designed. Its net electrical efficiency is about 55% (LHV), which is higher than that of the fire power plant. So it is environmental-friendly and high-efficient generation mode.

Bioelectric Energy Sources↗