Analysis of noise inside bus of hybrid bus vehicles

The article presents the results of noise measurements during a control passage recorded in the interior of a bus with a serial hybrid drive. The noise was recorded in a continuous mode, and the course was adjusted for the pressure level and spectrogram in the field of time and frequency

Application of vibration signal in the diagnosis of IC engine valve clearance

The article describes a concept of a non-invasive method for diagnosing the size of valve clearance in internal combustion engines, based on the analysis of engine surface vibration signals using artificial neural networks. The applicability of the method was tested on a single-cylinder compression-ignition engine with a low power rating, which had an OHV timing gear, acting indirectly on the valves, and manual adjustment of valve clearance. The method uses as diagnostic signals the readings of vibration sensors, which record the acceleration of engine head movement as a function of the angle of rotation of the crankshaft, with pre-set valve clearance values measured in a cold condition. From among the signals recorded, components corresponding to the impact of rocker arms against valve stems were identified and low-pass filtered in order to eliminate measurement interference. A classifier of selected features of the signals processed was constructed using artificial neural networks. This classifier recognizes signals generated by engines with correct valve clearance as well as those with too much and too little valve clearance

Application of the vibration signal in the diagnosis of the valve clearance of an internal combustion engine

The article describes a concept of a non-invasive method for diagnosing the size of the valve clearance of combustion engines based on an analysis of engine surface vibration signal using artificial neural networks. The applicability of the method was tested on a single-cylinder compression-ignition engine with a low power rating, which had an OHV timing gear acting indirectly on the valves and manual adjustment of valve clearance. The method uses as diagnostic signals the readings of vibration sensors, recording the acceleration of engine head movement as a function of the angle of rotation of its crankshaft, with pre-set values of valve lash measured in a cold condition. From among the recorded signals, components corresponding to the impact of rocker arms on valve stems were identified, and then these components were subjected to low-pass filtering in order to eliminate measurement interference. Using artificial neural networks, a classifier of selected measures of the processed signals was constructed, which recognizes signals generated by engines with correct valve clearance as well as those with too much and too little valve clearance

Emissions from a medium-duty crdi engine fuelled with diesel : biodiesel blends

In the present work, biofuels produced from different raw fatty materials have been proposed as a dominant fuel component in biodiesel–diesel fuel blends. Biofuels were produced from pork lard and rapeseed oil by alkali transesterification using methyl alcohol. Blends of biofuels in volumetric proportions of 60 and 80% of the biocomponent and the remaining part of the conventional fuel were used in a compression ignition engine designed for medium-duty vehicles. The experiments were conducted at two engine rotational speeds (1500 and 3000 rpm, respectively) and a set of load conditions (50, 100, and 200 Nm, respectively). The tests focused on engine efficiency parameters (brake-specific fuel consumption and brake fuel conversion efficiency) as well as exhaust gas emissions (hydrocarbons, carbon monoxide, and carbon dioxide were determined). The obtained results indicate that blends containing biocomponents produced from pork lard were characterized by superior fuel consumption and efficiency results, compared to blends containing biocomponents produced from rapeseed oil. In terms of exhaust emissions, biocomponents produced from pork lard were also characterized by lower emission of all of the examined components compared to rapeseed methyl ester–diesel blends. This study proposes that fuel components obtained from custom (animal) raw-fatty material can be an effective substitute for commonly used rapeseed oil methyl esters.© The Authors. Published by Exeley Inc. with Creative Commons licence (CC BY 4.0).fi=vertaisarvioitu|en=peerReviewed

Application of vibration signal in the diagnosis of IC engine valve clearance

The article describes a concept of a non-invasive method for diagnosing the size of valve clearance in internal combustion engines, based on the analysis of engine surface vibration signals using artificial neural networks. The applicability of the method was tested on a single-cylinder compression-ignition engine with a low power rating, which had an OHV timing gear, acting indirectly on the valves, and manual adjustment of valve clearance. The method uses as diagnostic signals the readings of vibration sensors, which record the acceleration of engine head movement as a function of the angle of rotation of the crankshaft, with pre-set valve clearance values measured in a cold condition. From among the signals recorded, components corresponding to the impact of rocker arms against valve stems were identified and low-pass filtered in order to eliminate measurement interference. A classifier of selected features of the signals processed was constructed using artificial neural networks. This classifier recognizes signals generated by engines with correct valve clearance as well as those with too much and too little valve clearance

Application of vibration signal in the diagnosis of IC engine valve clearance

The article describes a concept of a non-invasive method for diagnosing the size of valve clearance in internal combustion engines, based on the analysis of engine surface vibration signals using artificial neural networks. The applicability of the method was tested on a single-cylinder compression-ignition engine with a low power rating, which had an OHV timing gear, acting indirectly on the valves, and manual adjustment of valve clearance. The method uses as diagnostic signals the readings of vibration sensors, which record the acceleration of engine head movement as a function of the angle of rotation of the crankshaft, with pre-set valve clearance values measured in a cold condition. From among the signals recorded, components corresponding to the impact of rocker arms against valve stems were identified and low-pass filtered in order to eliminate measurement interference. A classifier of selected features of the signals processed was constructed using artificial neural networks. This classifier recognizes signals generated by engines with correct valve clearance as well as those with too much and too little valve clearance

Systemic and local vascular inflammation and arterial reactive oxygen species generation in patients with advanced cardiovascular diseases

BackgroundSystemic inflammation may cause endothelial activation, mediate local inflammation, and accelerate progression of atherosclerosis. We examined whether the levels of circulating inflammatory cytokines reflect local vascular inflammation and oxidative stress in two types of human arteries.MethodsHuman internal mammary artery (IMA) was obtained in 69 patients undergoing coronary artery bypass graft (CABG) surgery and left anterior descending (LAD) artery was obtained in 17 patients undergoing heart transplantation (HTx). Plasma levels of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were measured using ELISA, high-sensitivity C-reactive protein (hs-CRP) was measured using Luminex, and mRNA expression of proinflammatory cytokines in the vascular tissues was assessed. Furthermore, formation of superoxide anion was measured in segments of IMA using 5 uM lucigenin-dependent chemiluminescence. Vascular reactivity was measured using tissue organ bath system.ResultsTNF-α, IL-6 and IL-1β mRNAs were expressed in all studied IMA and LAD segments. Plasma levels of inflammatory cytokines did not correlate with vascular cytokine mRNA expression neither in IMA nor in LAD. Plasma TNF-α and IL-6 correlated with hs-CRP level in CABG group. Hs-CRP also correlated with TNF-α in HTx group. Neither vascular TNF-α, IL-6 and IL-1β mRNA expression, nor systemic levels of either TNF-α, IL-6 and IL-1β were correlated with superoxide generation in IMAs. Interestingly, circulating IL-1β negatively correlated with maximal relaxation of the internal mammary artery (r = −0.37, p = 0.004). At the same time the mRNA expression of studied inflammatory cytokines were positively associated with each other in both IMA and LAD. The positive correlations were observed between circulating levels of IL-6 and TNF-α in CABG cohort and IL-6 and IL-1β in HTx cohort.ConclusionsThis study shows that peripheral inflammatory cytokine measurements may not reflect local vascular inflammation or oxidative stress in patients with advanced cardiovascular disease (CVD). Circulating pro-inflammatory cytokines generally correlated positively with each other, similarly their mRNA correlated in the arterial wall, however, these levels were not correlated between the studied compartments

ASSESSMENT OF THE APPLICABILITY OF BASALT FIBER-REINFORCED EPOXY COMPOSITES IN VEHICLE CONSTRUCTION

This article presents a description of the properties of basalt fibers and polymer composites containing basalt fibers. Basalt fibers are seen as a potentially beneficial component in composite development, especially for vehicles in transport applications. The article also presents the results of the mechanical properties investigation of the glass-epoxy and basalt-epoxy composites. The composites for testing were prepared using the popular hand lay-up method. The samples were cut from prepared plates using abrasive water jet methods. The obtained samples were tested to evaluate their flexural strength and interlaminar sharing strength. The achieved mechanical properties were compared