Amount Of Chips Research Articles

Processing of Layered Composite Products Manufactured on the Basis of Bioresin Reinforced with Flax Fabric Using Milling Technology.

In this work, a laminate based on bioresin and natural fibers was produced. Flax fabric was selected as the natural fiber. The biocomposite was subjected to strength tests. Stress-strain characteristics and strength indicators were determined. The workability of the laminate produced was also tested using milling technology. The tests were carried out using five carbide shank cutters for different purposes. The cutters with the geometry used in the processing of polymer materials and composites, general purpose cutters, and cutters with the geometry for aluminum and with different numbers of blades were analyzed. In order to obtain information on the workability of the prepared material, machining tests with different configurations of technological parameters were carried out. For each cutter, the effect of cutting speed and feed rate on the quality of the machined surface was tested. Due to the small thickness of the laminate, the machining was carried out in one pass, as a result of which the cutting depth in each case was constant. Changes in cutting speed and feed were evenly distributed over five levels. The quality of machining was assessed in two stages. The first stage included a visual assessment of the machined surface, involving a preliminary qualification of the machining parameters. The criterion was the amount of chips, frays, burrs, etc., remaining after machining that adhered to the surface. The next stage was the measurement of the geometric structure of the surface, during which the roughness parameters were analyzed using an optical microscope with a roughness analysis attachment. Quantitative analysis was performed for the best quality composite surfaces from each measurement series. The studies showed a dependence of the quality of machining on the technological parameters used. High tool speed, regardless of the type, especially at low feed, led to the sticking of chips, which had a very delicate form. In turn, low tool speed and high feed, due to the chip thickness, favored the formation of burrs. Machining with different types of tools showed that the process progresses better for tools with sharp blade geometry. Machining with a regular and polished cutter did not show any differences in the scope of the process progress.

A Metallographic Preparation Method for Three-Dimensional Microstructural Characterization of Machining Chips

Abstract Chip formation is an important indicator of machining processes. Statistical characterization of machining chips’ geometric features can offer crucial information for evaluating the stability and productivity of the machining processes. In abrasive machining processes, an abundance of small chips are produced by the vast number of abrasives exposed to the cutting surfaces. Geometric features of abrasives, such as shape, dimension, and distribution, may be hierarchically passed on to the chips. Similar to those of the abrasives, geometric features of the chips may also vary to a certain extent and conform to some statistical distribution. To verify these characteristics, a metallographic preparation method in connection with chips formed in abrasive machining processes is proposed in this study. Challenges in collecting and segmenting chips have been successfully overcome through several steps using ultrasonic bath cleaning and powder cold embedding methods. Finally, a considerable amount of chips was formed and uniformly embedded in a resin mold, ready for microscopic characterization.

Система нечіткого автоматичного керування режимом руйнування вугіль-ного масиву виконавчим органом очисного комбайна

Up to now, automatic control of the shearer speed has been performed to keep the actual speed at an operator-specified level or to keep the actual power at a stable level without overheating or overturning. However, the problem of control of coal seam cutting by the upper drum of a shearer in the case of a variable angle of drum – coal seam contact has yet to be studied. The aim of this work is to develop a method for synthesizing a system of fuzzy automatic control of coal massif cutting by a shearer drum based on an information criterion for the power efficiency of coal cutting with cutters. In this work, based on an information criterion for the power efficiency of coal cutting with cutters, a fuzzy inference algorithm is constructed for a system of automatic control of coal massif cutting by a shearer drum. In doing so, the parameters of the output linguistic variable term membership functions of the system and fuzzy operations are determined according to the recommendations of the classical Mamdani fuzzy inference algorithm using substantiated fuzzy production rules. The fuzzy inference algorithm constructed in this work is tested for efficiency based on the fraction of effective control actions generated by the fuzzy automatic control system. Using simulation, the efficiency of drum rotation speed control with the use of the proposed fuzzy inference algorithm is compared with that with the use of an uncontrolled shearer cutting drive. The study of the generation of control actions involving the upper shearer drum rotation speed showed that effective control actions were generated in the overwhelming majority of cases (about 93%). The proposed method forms a theoretical basis for the solution of the important scientific and practical problem of upper shearer drum rotation speed control automation with the aim to reduce specific power consumption and the amount of chips.

An Approach to Improve Cutting Performance in Micromilling of Titanium Alloy

Abstract Application of liquid carbon dioxide to improve cutting performance in micro-end milling of Ti-6Al-4V titanium alloy was proposed in this study. It was found that the machined roughness decreased with the cutting speed as observed in the conventional cutting, when a 0.5 mm diameter end milling cutter was used in dry cutting. But, the tiny and shattered chips produced by the use of 0.3 mm diameter cutter could adhere on the machined surface and deteriorate surface finish, if the cutting speed was higher than 40 m/min. Cutting temperature was effectively decreased by applying liquid carbon dioxide during micromilling, which in turn reduced the amount of chips adhering on the machined surface and lowered flank wear. The surface roughness Ra at a cutting speed of 70 m/min was improved from 0.09 μm under dry cutting to 0.04 μm under the liquid carbon dioxide assisted cutting condition. And there were no flank wear and very few burrs left on the machined surface for the condition used in the experiment. The height of the burrs was only 25% of that under dry cutting. More, minimum quantity lubrication (MQL) was proposed to be applied together with the liquid carbon dioxide to enhance lubrication effect. It was noted that the machined surface roughness was further decreased by 15% as compared with that when the liquid carbon dioxide was applied alone. The height of burrs was reduced from 32 μm to 16 μm.

Evaluation of root-end cavity preparation using erbium, chromium:yttrium, scandium, gallium, and garnet laser, ultrasonic retrotips, and conventional burs

Aim: To compare root-end cavities prepared with ultrasonics (Group A), with those created by burs in a conventional handpiece (Group B) and erbium, chromium:yttrium, scandium, gallium, and garnet (Er, Cr:YSGG) laser (Group C). Materials and Methods: After root canal instrumentation and filling, apices of 60 single-rooted teeth were resected. Retrograde Class I cavities 3 mm deep were prepared using ultrasonic retro-prep tips (Group A), round burs (Group B), and Er:YSGG laser (Group C). An ultrasonic unit was used with computed tomography-5 retrotip at the frequency of 32 KHz. Laser beam parameters were a pulse of very short duration (100 s), energy of 280 mJ, and repetition rate of 10 Hz. The apical root portion and root-end cavities were replicated and prepared for stereomicroscopic analysis. Results: The degree of chipping associated with the margin of the root-end cavities and the incidence of root face cracks were noted. Marginal chipping of root-end cavities prepared using ultrasonic instrumentation was significantly higher than that produced by bur (P < 0.001) or laser, with laser group showing the least amount of chipping. Conclusion: There was a significant difference between the number of cracks produced by the three methods, with the laser group having the least number of cracks and marginal chipping.

Effect of the degree of toasting on the extraction pattern and profile of antioxidant polyphenols leached from oak chips in model wine systems

The effect of the degree of toasting of oak chips used in wine ageing on the extraction pattern of polyphenols was investigated using model wine systems. Pattern identification was carried out employing a Box–Behnken experimental design and response surface methodology, using resident time (t) and amount of chips (A Chip) as the independent variables. The responses selected to assess the process were the total polyphenol concentration, the antiradical activity and the reducing power of the model wines. Further, a deeper insight into the effects exerted by chip toasting was provided by the examination of the analytical polyphenolic composition of model wines, using liquid chromatography–mass spectrometry. The results obtained demonstrated that even moderate toasting provoked drastic decrease in the native oak wood polyphenols (ellagitannins), as indicated by the Folin–Ciocalteu assay, with a concomitant reduction in both the antiradical activity and reducing power. The evolution pattern for all three independent variables during model wine treatment with chips having different degree of toasting was also substantially affected. Light toasting was shown to generate a series of small molecular weight phenolics, but some of them did not survive more intense (heavy) toasting.

An Analysis of Industrial SRAM Test Results—A Comprehensive Study on Effectiveness and Classification of March Test Algorithms

This paper deals with efficient test algorithm identification of embedded SRAMs. The approach is based on silicon test results of automotive microcontroller devices, which tries to identify efficient tests by removing unnecessary test patterns that cover the same subset of faults. Results of an industrial case under 29 test algorithms and a large amount of chips are obtained; among them, efficient ones are identified.

TWO-PERSON RED-AND-BLACK GAME WITH LOWER LIMIT

In this article we consider a two-person red-and-black game with lower limit. More precisely, assume each player holds an integral amount of chips. At each stage, each player can bet an integral amount between a fixed positive integer ℓ and his possession x if x ≥ ℓ; otherwise, he bets all of his own fortune. He might win his opponent's stakes with a probability that is a function of the ratio of his bet to the sum of both players' bets and is called a win probability function. The goal of each player is to maximize the probability of winning the entire fortune of his opponent by gambling repeatedly with suitably chosen stakes. We will give some suitable conditions on the win probability function such that it is a Nash equilibrium for the subfair player to play boldly and for the superfair player to play timidly.

PROPORTIONAL THREE-PERSON RED-AND-BLACK GAMES

Consider a three-person game that occurs in stages. The state of the game is given by the integral amounts of chips that the players have, say x=(x1, x2, x3) with M=x1+x2+x3 fixed. At a stage of the game, player i places ai chips in the pot, an integer between 1 and xi. (Player i is already eliminated from the game if xi=0.) The winner of the pot is then immediately chosen in such a way that player i wins the pot with probability proportional to the index wiai for i with xi&gt;0. The idea is that if player i bets more, then he is more likely to win, but this is modified by weights that parameterize the players’ abilities.Each player is trying to maximize his probability of taking all the chips (i.e., reaching xi=M). In the two-person game, it is known that a Nash equilibrium is for each player to adopt strategy σ of playing timidly (ai=1) or boldly (ai=xi) according to whether the game is in his favor or not (assuming the other also plays σ). In this article, we investigate whether this also is the form of a Nash equilibrium in a three-person game when the weights are of the form (w1, w2, w3)=(w, w, 1−2w) with 0&lt;w&lt;1/2. It turns out that this is true if w&lt;1/3, but not true if w&gt;1/3 and M≥8.

CHIP Is Associated with Parkin, a Gene Responsible for Familial Parkinson's Disease, and Enhances Its Ubiquitin Ligase Activity

Unfolded Pael receptor (Pael-R) is a substrate of the E3 ubiquitin ligase Parkin. Accumulation of Pael-R in the endoplasmic reticulum (ER) of dopaminergic neurons induces ER stress leading to neurodegeneration. Here, we show that CHIP, Hsp70, Parkin, and Pael-R formed a complex in vitro and in vivo. The amount of CHIP in the complex was increased during ER stress. CHIP promoted the dissociation of Hsp70 from Parkin and Pael-R, thus facilitating Parkin-mediated Pael-R ubiquitination. Moreover, CHIP enhanced Parkin-mediated in vitro ubiquitination of Pael-R in the absence of Hsp70. Furthermore, CHIP enhanced the ability of Parkin to inhibit cell death induced by Pael-R. Taken together, these results indicate that CHIP is a mammalian E4-like molecule that positively regulates Parkin E3 activity.

Online Failure Detection in Face Milling Using Discrete Wavelet Transform

This paper describes an application of the Discrete Wavelet Transform (DWT) to detecting tool failures in face milling operations. The wavelet transform uses an analyzing wavelet function which is localized in both frequency and time to detect subtle time localized small changes in the input signals. In this paper, the DWT is used to detect tool failures such as small chipping and breakage of an insert tip including eccentricity of the tool rotation center. The results indicate that the DWT can extract tool failures with much greater sensitivity than the FFT even when the amount of chipping is very small. In addition, the DWT enables the analyst to determine which insert tip failed, since it yields time localized signal information. On-line diagnosis of tool failures are demonstrated in both simulated and actual cutting force signals by using simple pattern recognition technique.

Detection of Tool Failure in Milling Process Using Discrete Wavelet Transform.

This paper describes an application of the discrete wavelet transform (DWT) to detect tool failure in face milling operations. The wavelet transform uses an analyzing wavelet function which is localized in both frequency and time to detect subtle time-localized changes in the input signals. In this paper, the DWT is used to detect tool failure such as small chipping and breakage of an insert tip including eccentricity of the tool rotation center. The potential uses of the DWT for in-process diagnosis of tool failure are demonstrated using both simulated and actual cutting force signals in the milling process. The results indicate that the DWT can identify tool failure with much greater sensitivity than the FFT, even when the amount of chipping is very small. In addition, the DWT enables the analyst to determine which insert tip failed, since it yields time-localized signal information.

Influence on grinding ability of grinding fluid (3rd report, Action and effect of extreme pressure additives on working surface of CBN wheels in grinding)

A study was made of the effect of extreme pressure additives in wet grinding of steels by CBN wheels. The findings are as follows, (1) The extreme pressure additive contained in the grinding fluid conducts the reaction to the CBN layer to produce the solid lubricating film (ferric chloride or ferric sulfide) on the cutting edge of CBN grains. (2) The formation of the solid lubricating film reduces the degree to which chips and ground metal are deposited on the cutting edge of CBN grains. (3) The amount of chips and ground meal deposited on the grain coating zone and the bond surface is reduced by the reaction of extreme pressure additives on the metal-coated grain, metal powder contained in the resinoid bond and the metal bond. (4) If the dilution is raised in applying the water base type grinding fluid, the degree of action of the extreme pressure additive to the CBN grain, bond, chip and metal deposit is lowered.