Conservation conditions of chainsaws and electric chainsaws and safety of the farmers who operate these machines

The increasing use of chainsaws in rural areas has demanded the health of rural producers who operate these machines. Thus, the objective of this work was to evaluate the conservation conditions of chainsaws with a 2-stroke Otto Cycle engine and check if they meet NR12 Annex V, as well as confirm whether users meet NR31 in terms of training for use. With the aid of a questionnaire and visits to farms, 103 chainsaws were verified in six municipalities in the central region of the State of Rio Grande do Sul. After organizing the data in an electronic spreadsheet, descriptive statistics and canonical correlation were performed. The questions were divided into four groups, namely: operational, mandatory machine safety equipment, cutting set, and engine. The conservation condition of the machines was seen as worrisome. This is because it was found that 66.01% of machines did not have a saber guard and 49.51% of these were worn out. In addition, 97.08% of the producers did not take a chainsaw operation course, and 85.44% reported not using Personal Protective Equipment (PPE), therefore, in disagreement with the NR6, NR12 Annex V, and NR31 standards. It was clear the need for the operators to carry out training on the safe use and handling of chainsaws.

Shortcut-to-adiabaticity quantum tripartite Otto cycle

For an Otto cycle there always exists a trade-off between the cycle efficiency and the output power due to the requirement of cycle length. The shortcut to adiabatic (STA) technology provides an effective way to deal with the difficulty of zero-output power in conventional Otto cycle. In this paper, the Otto cycle of three-qubit system as the working substance (WS) with counterdiabatic (CD) driving has been investigated. It is demonstrated that the tripartite Otto cycle as a universal machine, in the suitable regimes of external control parameter, could work as a quantum heat engine (QHE), refrigerator or heat pump. And, the performances of QHE and refrigerator with and without STA, such as the power and efficiency of QHE and the coefficient of performance (COP) and figure of merit (FOM)) of refrigerator, have been investigated. It shows the application of STA scheme can lead to an effective enhancement in the performances of Otto cycle, including achievements of a high QHE’s/refrigerator’s power associated with a moderate QHE’s efficiency/COP of refrigerator. Especially, it is interesting that even in a short-time cycle the optimization of control parameters could arise a remarkable improvement in the efficiency (or COP) of STA QHE (refrigerator), approaching the ideal efficiency or COP of conventional Otto cycle with quasi-static process. Finally, with the aid of parameter optimization the trade-off regions between the efficiency and the power (the COP and the FOM) of STA Otto engine (refrigerator) have been advised.

Research of the efficiency of using the Miller cycle of an internal combustion engine

The article is devoted to the study of the possibilities of improving the technical and economic indicators of an internal combustion engine (ICE) through the use of the Miller cycle with a shortened intake. A review of scientific works on the use of the Atkinson cycle and Miller cycle in an internal combustion engine is carried out. A comparative analysis of theoretical cycles: Otto cycle, Atkinson cycle and Miller cycle is carried out. Calculated studies of the influence of the expansion ratio and the pressure increase ratio on the efficiency of the Atkinson cycle have been carried out. The ratios are presented that allow using the Miller cycle with a short inlet to obtain the same theoretical efficiency of the cycle as that of the Atkinson cycle. At the same time, the implementation of the Miller cycle in a real engine design significantly exceeds the possibilities of using the Atkinson cycle. The results of the study showed that the use of the Miller cycle with a shortened intake is preferable, but it must necessarily increase the compression ratio and intake pressure through the use of boost. On the example of real data of the main parameters of the cycle, it is shown that the use of the theoretical Miller cycle can provide a significant up to 12.2% increase in the efficiency of the cycle compared to the Otto cycle. The ratios, conditions and recommendations are presented that allow the effective use of the Miller cycle with a shortened intake in a real engine design.

Analysis of Ethanol to Reduce Solid Particle Pollution in SI Engines

The present work carries out an experimental comparative analysis of the performance and emission of exhaust gases of the Otto cycle with four automotive times. The comparison was made between alternative fuels such as E10, E15, and E20, with both 90 and 95 octane each the commercialized fuel. The experimental tests were carried out with an engine load corresponding to 25% of the maximum load. After carrying out the tests, the following conclusions can be reached: on the performance and effective parameters of the engine, the obtained best indicator, and as expected, was the case E10 (90 octane). Also, the E15 (90 octane) showed a slight difference compared to the reference fuel E10 (90 octane). About emissions, it was found that these decrease as the concentration of ethanol in the fuel increases.

Non-commutative space engine: A boost to thermodynamic processes

We introduce quantum heat engines that perform quantum Otto cycle and the quantum Stirling cycle by using a coupled pair of harmonic oscillator as its working substance. In the quantum regime, different working medium is considered for the analysis of the engine models to boost the efficiency of the cycles. In this work, we present Otto and Stirling cycle in the quantum realm where the phase space is non-commutative in nature. By using the notion of quantum thermodynamics, we develop the thermodynamic variables in non-commutative phase space. We encounter a catalytic effect (boost) on the efficiency of the engine in non-commutative space (i.e. we encounter that the Stirling cycle reaches near to the efficiency of the ideal cycle) when compared with the commutative space. Moreover, we obtained a notion that the working medium is much more effective for the analysis of the Stirling cycle than that of the Otto cycle.

Comparative Study of Combustible Species for 4-stroke Otto Cycle Combustion Motor and 6-stroke MUB-2 Cycle Combustion Motor with Fuel Pertamax

This paper describes the ratio of levels of combustible species (CO, HC, CO2 and lambda) of a four-cycle otto motor with a six-stroke MUB-2 motor with additional combustion duration and two working steps. The increase in combustion duration aims to re-burn combustible species that have not been completely burned in the first combustion. This study used a 4 stroke motor with a capacity of 125 cc and then modified it into a 6 stroke motorbike with twice the duration of combustion. The observed local atmospheric conditions at a relative humidity of about 76% rH, and the ambient temperature and pressure were around 24 ° C and 101.32kPa, respectively. The implementation of data retrieval with crankshaft rotation at intervals of 600 rpm from 2400 rpm to 7200 rpm.Using an anlyser gas, the MUB-2 six-stroke engine showed 12.36% CO levels, 27.30% HC levels, 30.8 CO2 levels % and 1.7% lower lambda than conventional four-stroke engines. This means that in the 6 stroke MUB-2 motor, the combustion process of the air and fuel mixture is more perfect than the conventional 4 stroke motor.

Non-Markovian quantum Otto refrigerator

Based on a recently developed non-perturbative platform designed to simulate the full quantum dynamics of quantum thermal machines, the situation of a quantum refrigerator operating according to an Otto cycle is studied. The periodic steady-state dynamics is discussed in detail as well as the key thermodynamic quantities work, heat, and entropy. A particular benefit of the formulation is that it allows to access explicitly the work required for switching on and off the interaction with the respective thermal reservoirs in a consistent way. The domains in which the device operates in refrigerator mode are characterized.