Absorbed power distribution in the whole-body system of a tractor operator.
INTRODUCTION AND OBJECTIVE
Many people are exposed to vibration (WBV) in their occupational lives. The biodynamic responses of the human body in sitting conditions have been widely measured under whole-body vibration (WBV). The measures are most often expressed in terms of force-motion relations at the driving-point, namely, mechanical impedance, apparent mass and absorbed power, and flow of vibration through the body, such as seat-to-head and body segments vibration transmissibility. The absorbed power is a measure of the energy absorbed by the subject due to the external forces applied to the system.


MATERIALS AND METHODS
The body behaves like a vibrating physical system with distributed energy-storage elements (masses, springs) and energy-dissipation elements (dampers). The total quantity of power can be divided into 2 components - one real and one imaginary. The real component reflects the energy-absorbing part of the system, due to the transformation of friction into heat within the tissues. The imaginary component reflects the energy-storing part of the system which does not consume any vibration energy.


RESULTS
The seated human is modeled as a series 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator's body segments has been determined as a function of the agricultural combination operating speed 1.4 - 2.75 ms(-1).


CONCLUSIONS
The concept of absorbed power as a measurement for evaluation of WBV exposure opens a new area for research. The important character of absorbed power is that it has physical significance and therefore can be measured as well as computed analytically. The absorbed power relates to dissipation of energy attributed to relative motions of the visco-elastic tissues, muscles and skeletal system, which under prolonged exposures could lead to physical damage in the musculoskeletal system. A structural model of the human operator allows determination of the dynamic characteristics of the model, and study of the energy flow between the elements of the model.
Automotive Thermoelectric Generator impact on the efficiency of a drive system with a combustion engine
Increasing the combustion engine drive systems efficiency is currently being achieved by structural changes in internal combustion engines and its equipment, which are geared towards limiting mechanical, thermal and outlet losses. For this reason, downsizing. In addition to these changes, all manner of exhaust gas energy recovery systems are being investigated and implemented, including turbocompound, turbogenerators and thermoelectric generators. The article presents the author’s idea of a thermoelectric generator system of automotive applications ATEG (Automotive Thermoelectric Generator) and the study of the recovery of exhaust gas energy stream. The ATEG consists of a heat exchanger, thermoelectric modules and a cooling system. In this solution, 24 commercial thermoelectric modules based on Bi 2 Te 3 (bismuth telluride) were used. Measurements were made at two engine test sites on which SI and CI engines were installed. The exhaust gas parameters (temperature and mass flow rate), fuel consumption and operating parameters of the ATEG – the intensity and the voltage generated by the thermoelectric modules and the temperature on the walls of the heat exchanger – were all measured in the experiments. Based on the obtained results, the exhaust gas energy flow and the power of the ATEG were determined as well as its effect on the diesel engine drive system efficiency.
Air scrubbing techniques for ammonia and odor reduction at livestock operations : review of on-farm research in the Netherlands
Acid scrubbers and biotrickling filters have been developed for ammonia (NH3) removal at pig and poultry houses 
in The Netherlands over the last 20 years to prevent acidification and eutrophication of soils. Because of growing 
suburbanization, odor removal is increasingly considered important as well. In this review, we report the results of the on-farm 
research on full-scale operated scrubbers for treatment of exhaust air from animal houses with regard to NH3 and odor 
removal in The Netherlands. The NH3 removal of acid scrubbers ranged from 40% to 100% with an overall average of 96%. 
The NH3 removal of biotrickling filters ranged from -8% to +100% with an overall average of 70%. Minimum empty bed air 
residence times (EBRTs) were 0.4 to 1.1 s. For acid scrubbers, process control with pH measurement and automatic water 
discharge is sufficient to guarantee sufficient NH3 removal. For biotrickling filters, however, improvement of process control 
is necessary to guarantee sufficient NH3 removal. The odor removal of acid scrubbers ranged from 3% to 51% with an overall 
average of 27%. The odor removal of biotrickling filters ranged from -29% to +87% with an overall average of 51%. 
Minimum EBRTs were 0.5 to 2.3 s. Further research is necessary to explain this variation and to improve the odor removal 
efficiency of both acid scrubbers and biotrickling filters.