Study of the conrod deformation during piston interaction with liquid in the internal combustion engine cylinder

The paper analyzes the deformation of the connecting rod stem with buckling due to water ingress into the internal combustion engine cylinder (the so-called hydrolock). A method is presented that has been developed to perform calculations of stem deformation in the process of compressing air with liquid in an internal combustion engine cylinder. The method is based on solving a system of differential equations for pressure and temperature in the cylinder, followed by calculating the compression force acting on the connecting rod. A carried-out simulation of the compression process demonstrates the dependence of the air pressure in the cylinder, the stress and the strain of the connecting rod on the fill ratio of the combustion chamber with liquid. The calculations performed according to the classical theory of resistance of materials have shown that the connecting rod with the buckling of the stem begins to deform when the liquid fills the combustion chamber to a minimum of 80%. With the increase in the amount of liquid, the deformation of the conrod increases, and when the level of liquid filling is so significant that it exceeds the volume of the combustion chamber, the conrod stem deformation reaches extreme values. It is shown that under these conditions after the hydrolock occurs the engine may fail due to the piston wedging the crankshaft in the bottom dead center position.

Text Filtering through Multi-Pattern Matching: A Case Study of Wu–Manber–Uy on the Language of Uyghur

Given its generality in applications and its high time-efficiency on big data-sets, in recent years, the technique of text filtering through pattern matching has been attracting increasing attention from the field of information retrieval and Natural language Processing (NLP) research communities at large. That being the case, however, it has yet to be seen how this technique and its algorithms, (e.g., Wu–Manber, which is also considered in this paper) can be applied and adopted properly and effectively to Uyghur, a low-resource language that is mostly spoken by the ethnic Uyghur group with a population of more than eleven-million in Xinjiang, China. We observe that technically, the challenge is mainly caused by two factors: (1) Vowel weakening and (2) mismatching in semantics between affixes and stems. Accordingly, in this paper, we propose Wu–Manber–Uy, a variant of an improvement to Wu–Manber, dedicated particularly for working on the Uyghur language. Wu–Manber–Uy implements a stem deformation-based pattern expansion strategy, specifically for reducing the mismatching of patterns caused by vowel weakening and spelling errors. A two-way strategy that applies invigilation and control on the change of lexical meaning of stems during word-building is also used in Wu–Manber–Uy. Extra consideration with respect to Word2vec and the dictionary are incorporated into the system for processing Uyghur. The experimental results we have obtained consistently demonstrate the high performance of Wu–Manber–Uy.

Mach stem deformation in pseudo-steady shock wave reflections

The deformation of the Mach stem in pseudo-steady shock wave reflections is investigated numerically and theoretically. The numerical simulation provides the typical flow patterns of Mach stem deformation and reveals the differences caused by high-temperature gas effects. The results also show that the wall jet, which causes Mach stem deformation, can be regarded as a branch of the mainstream from the first reflected shock. A new theoretical model for predicting the Mach stem deformation is developed by considering volume conservation. The theoretical predictions agree well with the numerical results in a wide range of test conditions. With this model, the wall-jet velocity and the inflow velocity from the Mach stem are identified as the two dominating factors that convey the influence of high-temperature thermodynamics. The mechanism of high-temperature gas effects on the Mach stem deformation phenomenon are then discussed.

Threshing and Grain Separating Mechanism with Differentiate Concave for Intensification of Threshing and Grain Separation

The objective of the paper was intensification of the process of threshing and grain separation by a rasp-bar threshing mechanism of a combine harvester with a differentiate concave; substantiation of a regular-style design and differentiate concave parameters as well as threshing and separating mechanism operation modes. Theoretical research has been conducted based on laws of motion, experimental investigation – in accordance with methods devised on the basis of conventional methodologies. Standard computing methods as well as Microsoft Excel and Mathcad application packages have been used for processing experimental data. Measuring and recording equipment has been used in the research process. Experimental investigation has been carried out on specially devised experimental assemblies. The research has enabled: to substantiate the design-manufacturing process of the threshing and separating mechanism with a differentiate concave; to establish analytical dependencies to determine the area of typical influence zones of a threshing drum and concave on threshing mass; to ascertain the regularity of stem deformation under the influence of different forces regulated by changing the distance between concave transverse slats; to figure out the regression equation enabling finding optimal process variables for a threshing and separating mechanism with a differentiate concave. The scientific novelty of the engineering solutions is confirmed by a patent of the Republic of Belarus for the utility model № 6335 « Tresking mechanism». The results of theoretical and experimental research have been used in developing design documentation for the production of a differentiate concave for combine harvesters PA «Gomselmash».

Model development for lumber volume recovery of natural balsam fir trees in Quebec, Canada

To improve the precision of sawing simulations, 4 regression models were developed to predict simulated lumber volume recovery using tree size variables. Simulated lumber volume recoveries from natural balsam fir trees based on the sawing simulator Optitek were different from real lumber volume recoveries from a stud sawmill because the simulation method only takes wane into consideration. Therefore, 2 methods were developed to correct estimated lumber volume recoveries. The results indicate that the lumber volume correction models for stem deformations could adjust the predictions of lumber volume recovery from the simulation and directly from the sawing simulator to obtain more accurate estimates. With the correction models, the lumber volume recovery from natural balsam fir trees could be estimated directly using easily measured tree DBH and height from the forest resource inventory. Key words: balsam fir, stem deformation, product recovery, sawing simulation, correction models, regression model

The effect of age and sample position on eucalypt tree-ring width series

In this study, we examine within-tree variance in proportionate tree-ring width (prw) and correlation between radii (rwt), samples (rbh), and trees (rbt) in four eucalypt species common throughout eastern Victoria, Australia. In all species and sites studied, rwt and rbh differ significantly between cambial-age and sample-height classes. Differences between rwt and rbh are nonsignificant between tree-age or radial-azimuth classes. Significant differences in prw exist between cambial-age, tree-age, and sample-height classes and between radii on different compass bearings. Whilst differences in rwt and rbh between cambial-age classes appears to be the result of variation in mechanical demands with increasing stem size, stem deformation may account for differences between sample-height classes. Variation in prw appears to be due to stem geometry, stem eccentricities associated with root buttressing, and tree-age dependent variation in the rate of radial growth. No significant differences in rbt exist between sample-height classes. Analysis of the expressed population signal statistic indicates that site-level and species differences are far more significant than sample position on variance within tree-ring width series collected from eucalypts. We discuss the implications of the current work for eucalypt dendroclimatology.

Influence du gauchissement de semis d'épinette noire (Picea mariana (Mill.) B.S.P.) produits en serre sur leur performance en plantation

Spiralization is a developmental deformation in winter greenhouse produced black spruce seedlings characterized by a drooping stem or portion of stem. During lignification, the seedling redresses but maintains part of its deformation. The objective of this study is to evaluate the long-term effect of spiralization on the growth, survival and morphology of black spruce seedlings in order to determine to what degree the rejection of spiralized seedlings is justified. Field evaluation was undertaken on 2304 black spruce seedlings planted on three sites with different soil conditions in Abitibi, Québec. The seedlings were divided in the greenhouse into six stem deformation classes of varying intensities, including a control, and laid out on a randomized complete block design. From 1986, the year of plantation, to 1990, spiralization had little effect on height and diameter growth. However, severely deformed seedlings planted on a heavy-textured site suffered sufficiently high mortality rates to justify their rejection. Moreover, these seedlings developed a higher proportion of double leaders. The study suggests that systematic rejection of all classes of deformed seedlings, especially those in the less severe classes, is probably not justified. Key words: Spiralization, stem deformation, seedlings, planting, black spruce, greenhouse, early growth, mortality.