Experiments on Waste Heat Thermoelectric Generation for Passenger Vehicles

In order to utilize waste heat from passenger vehicles by a thermoelectric generator (TEG), a lab-scale TEG with a sufficient low-pressure drop was designed and tested. The waste heat from a 2.0 L petrol engine was simulated by using an air-circulation channel with an adjustable electric heater and a speed control motor. The TEG consisted of an integrated molding designed aluminum-finned heat collector, twenty thermoelectric modules, and a set of water-cooled heat sinks. Experiments were conducted in terms of power load feature, pressure drop, heat collection efficiency, thermoelectric efficiency and overall efficiency. It was found that the hot-end temperature was much lower (46.9%) than the flue gas temperature because the trade-off between fin area and pressure drop had to be considered. The obtained maximum electric power was 36.4 W, and the corresponding pressure drop was 36 Pa. The corresponding heat collection efficiency was 46.5%, and the thermoelectric efficiency was 2.88%, which agreed well with the theoretical prediction of 3.38%. As a result, an overall efficiency of 1.21% was reached. The present work firstly demonstrated a waste-heat-recovering TEG prototype with a balanced overall efficiency of over 1%, and a pressure drop of less than 50 Pa. On the other hand, the maximum electric power was difficult to fully extract. The charging power to a battery with a maximum power point tracking direct current–direct current converter was experimentally verified to work at a much higher conversion efficiency (15.3% higher) than regular converters.

The Potential of a Separated Electric Compound Spark Ignition Engine for Hybrid Vehicle Application

In-cylinder expansion of internal combustion engines based on Diesel or Otto cycles cannot be completely brought down to ambient pressure, causing a 20% theoretical energy loss. Several systems have been implemented to recover and use this energy such as turbocharging, turbo-mechanical and turbo-electrical compounding, or the implementation of Miller Cycles. In all these cases however, the amount of energy recovered is limited allowing the engine to reach an overall efficiency incremental improvement between 4% and 9%. Implementing an adequately designed expander-generator unit could efficiently recover the unexpanded exhaust gas energy and improve efficiency. In this work, the application of the expander-generator unit to a hybrid propulsion vehicle is considered, where the onboard energy storage receives power produced by an expander-generator, which could hence be employed for vehicle propulsion through an electric drivetrain. Starting from these considerations, a simple but effective modelling approach is used to evaluate the energetic potential of a spark-ignition engine electrically supercharged and equipped with an exhaust gas expander connected to an electric generator. The overall efficiency was compared to a reference turbocharged engine within a hybrid vehicle architecture. It was found that, if adequately recovered, the unexpanded gas energy could reduce engine fuel consumption and related pollutant emissions by 4% to 12%, depending on overall power output.

Entrepreneurship and Innovation in the Polish Industry

Entrepreneurship is a process in which goals or tasks are set at one’s own initiative, whereby no efforts are spared to ensure their efficient and effective implementation. The concept of entrepreneurship is associated with innovation as entailing ongoing research and the introduction of rational changes and novel ideas. The aim of the research is to determine the regression interdependencies between the number of enterprises (entrepreneurship) and process and product innovation expenditure (innovators' activity) and the number of inventions (inventors' activity), and in the second regression model: also the number of enterprises (entrepreneurship) and process and product innovative expenditure (innovators' activity) and the number of patents (inventors' activities) generated within the Polish industry in the years 2015-2017. The hypothesis is that patents (inventors' activities) get reinforced with process and product innovation expenditures (innovators’ activities) employed in the process of growth of the number of enterprises (entrepreneurship) in industry, as well as the overall efficiency of expenditures and technologies (patents) in the Polish industry over the course of the researched years. Conducted studies have confirmed the above hypothesis. In addition, the research carried out has shown that patents (inventors 'activities) have supplemented the share (elasticity) of process and product innovation (innovators' activities) by 10% in the increase in the number of enterprises (entrepreneurship) as observed in industry. This share is transferred from the supply element to that of demand.

Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

A thermodynamic model is presented for evaluation of a solar hybrid gas-turbine power plant. The model uses variable ambient temperature and estimates direct solar radiation at different day times. The plant is evaluated in Barranquilla, Colombia, with a solar concentration system and a combustion chamber that burns natural gas. The hybrid system enables to maintain almost constant the power output throughout day. The model allows optimizing the different plant parameters and evaluating maximum performance point. This work presents pressure ratio ranges where the maximum values of overall efficiency, power output, thermal engine efficiency and fuel conversion rate are found. The study is based on the environmental conditions of Barranquilla, Colombia. The results obtained shows that optimum pressure ratio range for power output and overall efficiency is between 6.4 and 8.3, when direct solar radiation its maximum at noon. This thermodynamic analysis is necessary to design new generations of solar thermal power plants.

Вклад распределенного эффекта Пельтье в эффективность ветви термоэлектрического охладителя

An attempt is made to calculate the contribution of the distributed Peltier effect to the efficiency of the branch of the thermoelement Z for various types of impurity distribution. For this purpose, the boundary problem of thermal balance in the branch of the thermoelectric element was solved numerically, taking into account the distributed Peltier effect. The case of non-degenerate charge carriers was considered within the framework of the standard two-band model. The parameters of charge carriers were selected close to thermoelectrics based on bismuth and antimony tellurides. As the calculation in the framework of the two-zone model showed, the use of the distributed Peltier effect leads only to partial absorption of Joule heat, which contributes to an increase in the overall efficiency of the branch. In this case, the Z parameter along a significant part of the branch takes values significantly less than the maximum value

The Use of κ-Carrageenan in Egg Yolk Free Extender Improves the Efficiency of Canine Semen Cryopreservation

κ-Carrageenan is a plant polysaccharide derived from red seaweeds reported to possess potential medicinal and antioxidants activities. The present study aimed to identify the cryoprotective effects of κ-carrageenan on the quality of frozen-thawed canine semen. Twenty-eight ejaculates were collected and diluted in a Tris egg-yolk-free extender supplemented with various concentrations of κ-carrageenan (0.0%, 0.1%, 0.2%, 0.3%, and 0.5%). The addition of κ-carrageenan to the extender at a 0.2% concentration induced a significant increase in the total motility (TM) and the rapid progressive motility (RPM) of canine sperm. Among the experimental groups, the highest percentage of sperms with intact acrosomes was found in the 0.5% κ-carrageenan group (p < 0.05). Apoptosis levels were significantly lower in the 0.1% and 0.2% κ-carrageenan treatment. Moreover, sperm in the κ-carrageenan supplemented group showed a significantly higher expression of antiapoptotic (Bcl-2) and lower expression of NADPH oxidase (NOX5), spermine synthase (SMS), and spermine oxidase (SMOX) genes than those in the control group. In conclusion, the addition of κ-carrageenan to the freezing extender improved the overall efficiency of frozen-thawed dog spermatozoa.

MAXIMIZING IN VITRO EMBRYO PRODUCTION IN CATTLE

In vitro embryo production (IVEP) is used to develop high-quality genetics associated with intergenerational genetic gain. It is characterized by acquisition (in vivo or post-mortem) and maturation (MIV) of oocytes from donors, followed by fertilization (FIV) of matured oocytes and culture (IVC) of embryos, which are then sent to transferred or cryopreserved. Even with extensive knowledge on IVEP, some biochemical and hormonal regulations that involve embryonic development are still unknown, leading to a low overall efficiency of the biotechnological process. Although in vitro developed embryos have a lower quality than that produced in vivo, in terms of resistance to challenging events, IVEP presents itself as a potential biotechnology. In cattle breeding, reproductive biotechnologies are key to increase and improve the genetic improvement of the herd, associated with productive and reproductive efficiency. In this article, the steps and strategies of IVEP and its contribution to reproduction in the cattle sector are discussed.

A COMPACT AND PORTABLE DESIGN DEVELOPMENT OF A LOW ROLLING RESISTANCE TEST RIG

Low Rolling Resistance (LRR) conveyor systems are generally preferred over traditional conveyors because of better overall efficiency lesser energy consumption required to operate. In this work, the design development and analysis path in the process of downscaling the size of an existent LRR test rig to a compact, portable and desktop-sized model is presented. Simulation has been developed using SolidWorks and finite element analysis is conducted using ANSYS to obtain the deformation, stress and strain of each part of the new design.

Dendroarchaeology Potential in Various Natural Areas in West Siberia

Scientists face with many limitations that affect the success of dendrochronological dating working with archaeological (architectural) sites in Western Siberia. Here we analysed 134 sites and carried out the existing limitations of the method in different natural areas. As a result, a connection between the efficiency of dendrochronological dating and the physical and geographical conditions of sites was found. Created algorithm allowed to assess the potential of dendrochronology for the forest-steppe, taiga and forest-tundra areas of Western Siberia. The scientific results presented in the article can be used to solve the problems of chronology and periodization of archaeological and architectural sites of Western Siberia, as well as to increase the overall efficiency of the application of the dendrochronological method.

Solar Preheating in Power Plants: An Overview Of The Current State Of The Technology

Utilizing preheating units is one of the most critical ways to improve the performance of thermal power plants. Increasing the overall efficiency of Brayton or Rankine cycles by preheating the air or stream may result in considerable increases in output power and efficiency. When it comes to renewable energy, solar energy is an appealing alternative for use as a source of preheating since it is readily accessible. The current article discusses the use of solar energy for preheating air and steam in thermal power plants, as well as other uses. The performance of the systems is being improved, according to evaluations, as a result of a variety of elements, including the configuration of the reference system, the operating environment, the applied technology, and so on. Aside from improving the overall efficiency of the power plant, the incorporation of a solar preheating system may significantly decrease fuel usage and, as a result, carbon dioxide emissions. Furthermore, owing to the unavailability of solar energy during the night and overcast hours, thermal storage units may improve the system's dependability while also increasing the contribution of solar energy to the system's output.