Abstract— The Theory of Constraints (TOC) offers an interesting alternative to the use of management tools, in especial yours TOC cycle. Although it is an interesting alternative, only a small number of publications focus on the TOC cycle. This article aims to describe the TOC cycle and to present its application in the furniture industry, aiming to show a simplified method of your application. The approach is exploratory and descriptive, with a bibliometric analysis and case study. After finding a restricted number of publications, some of the articles were analyzed and it was possible to propose and demonstrate a simplified method for the application of the TOC. From the application of the five steps of TOC cycle, it was possible to identify and eliminate the bottlenecks. The results obtained were positive, because in less than a year the productive process presented productivity gains and a change in the organizational culture.
Keywords— Theory of Constraints, Five Steps, Gain, Productivity.
Abstract— In this paper, we propose a new path planning method by using an electromagnetism-like mechanism algorithm. We use the different encoding method to solve trade-off problem that is encountered in the traditional path planning method. By combining different encoding method with electromagnetism-like mechanism algorithm, path point can be generated without the trade-off problem. In order to connect these points into smooth curve, we compare two path smoothing method, Bezier curve and cubic splines interpolation. Finally, cubic splines interpolation is used because it can generate smoother path.
Keywords— Path Planning, Electromagnetism-like Mechanism Algorithm, Path Smoothing.
Antioxidant Activity of gossypitrin isolated from the petals of Talipariti elatum (Sw.) Fryxell (Malvaceae) in Cuba
Abstract— Talipariti elatum Sw. Fryxell (Malvaceae) is an endemic tree widely distributed in Cuba. The flowers are used in traditional medicine for the treatment of asthma. It was decided to search for any product responsible of this devoted activity. From the flower leaves (petals) it was isolated a flavonoid glycoside characterized as Gossypitrin and a sample was evaluated for its in vitro scavenging effects on reactive oxygen species (ROS) (O.-, HO., HOCl, ROO., and H2O2), reactive nitrogen species (RNS) (ONOO– and NO) and ABTS•+, DPPH. radicals and Reducing Power assay. Additionally, two enzymatic assays (Inhibition of xanthine oxidase (XO) and Effect on XO activity) were also evaluated. In the scavenging assays the sample showed to be not effective against all assayed ROS and RNS, and displayed a weak activity in the DPPH and Reducing Power assays, but it displayed a good activity in the ABTS•+ assay (2, 14 mM). The enzymatic assays corroborated that Gossypitrin shows a weak activity on inhibition of XO. These results provide scientific support for the empirical use of the flowers of T. elatum as an antasthmatic medicine.
Keywords— Talipariti elatum, scavenging effect, reactive oxygen species, reactive nitrogen species, antioxidant activity.
Experimental and Finite Element Analysis of Flow Behavior of 2A14 Aluminum Alloy during Multi-directional Forging
Abstract— The deformation flow behavior of 2A14 aluminum alloys during multi-directional forging (MDF) under various cumulative strains (∑Δɛ) has been investigated by combining experiment with finite element method (FEM). The forging process has been performed at 450oC with a deformation speed of 0.15 mms-1 and a pass strain (Δɛ) of 0.4. Numerical simulations of MDF using a commercial software (DEFORM-3D), have shown that the vortex, cross-flow and fold defect of flow lines of the forgings do not occur during deformation, and the degree of bent and inhomogeneity of flow lines also increase steadily with ∑Δɛ increases. The FEM analysis coincides well with experimental results. The effective strain in various areas of the forgings has been significantly enhanced during MDF. The dynamic recovery is dominant during deformation. The proportion of recrystallized grains and the degree of fragmentation of second phases in various areas of the annealed forgings increase with the increase of effective strain.
Keywords— 2A14 aluminum alloy, Multi-directional forging, Flow behavior, Effective strain, DEFORM-3D.
Abstract— It is found experimentally, that while building-up of pressure applied to natural clay, observed is general tendency of clay fraction content decrease and pulverescent fraction content increase. In montmorillonite natural clay, granulometric changes progress more intensively, than in kaolinite one. Within the pressure range of 0 – 125МPа processes of change of natural clay fractional compositions progress more intensively, than at higher pressures. Under pressures within the ranges of 125-750МPа and 800-2200МPа revealed is different intensity of natural clay fractional compositions formation. Based on pressure index, three classes are defined; each is featuring different intensity of aggregation and dispersion processes progressing. While compression of natural clay defects are formed on crystallite surfaces, increasing energy potential of crude ground. Additional energy enables formation of molecular attractive forces, which cause particles aggregation.
Keywords— Clay, Pressure, Granulometric Analysis, Fraction, Kaolin, Montmorillonite.
Abstract— This paper is based on a deep foundation pit project under the geological conditions of karst. The monitoring data is analyzed, and the deformation rule of the foundation pit is obtained. At the same time, the influence factors of foundation pit deformation are studied, and the relationship between the displacement of slope of foundation pit at different stages is studied. Get conclusions as following, in the excavation of the foundation pit, the different supporting forms of foundation pit have great influence on the horizontal displacement of foundation pit. The horizontal displacement deformation of slope at the excavation stage is larger, accounting for 68%~78% of total deformation. The horizontal displacement deformation of slope at the backfill stage is significantly smaller, accounting for 22%~32% of the total deformation.
Keywords— Foundation pit; deformation analysis, The foundation pit monitoring, Horizontal deformation of slope top, The vertical displacement of the slope.
Experimental of surface roughness and tool wear on coolant condition technique using Aluminium alloy 319 used in automotive industries
Abstract— The present day the applications of machining part tolerances, like the automotive industries aimed to reduce the fuel consumption of their vehicle by reducing the total mass per vehicle and the method process for machining. Understanding of the interaction and significance machining parameters are important to improve the efficiency of any machining process and the accuracy part produced. The objective of this research is to analyze the machining parameters (spindle speed, depth of cut and feed rates) in a three machining conditions (dry, wet and 1.0 mm coolant nozzle size on the surface roughness and tool wear using Respond Surface Method (RSM) on the CNC Lathe machine with 2 axes movements. The synthetic soluble oils, and coated cemented carbide Al2 O3 insert were used as a workpiece material and cutting tool respectively. The result of the machining experiment for Aluminum alloy 319 was investigated to analyze the main factor affecting surface roughness using the analysis of Variance (ANOVA) method. The optimum selection of the cutting conditions effectively contributes to the increase in the productivity and reduction in the production cost; therefore almost attention is paid to this problem. In cutting process, optimization of cutting parameters is considered to be a vital tool for improvement in output quality of a product as well as reducing the overall production time. The acquired results showed that the coated cemented carbide Al2 O3 insert gives the optimum overall performance in terms of surface roughness and tool wear with the smallest orifice size coolant. The research also beneficial in minimizing the costs incurred and improving productivity of manufacturing firms using the mathematical model and equations, generated by CCD based on RSM method.
Keywords— Turning, infrared, cutting temperature, coated carbide tool, Response Surface Method.
Abstract—Carbon 3D structures were obtained by spray pyrolysis using toluene solution containing suspended nickel or magnesium phthalocyanines as precursors of metallic particles serving as catalysts for carbon phase formation. The process was conducted in a range of temperatures in a quartz tube in inert atmosphere on borosilicate glass supports where the nanometric layers of nanoparticles were deposited. The samples were analyzed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Infrared Spectroscopy Fourier Transform (FTIR) and Raman spectroscopy; their condusctivity was measured via Kelvin technique. The properties of formed nanolayers were analyzed according to metal nature in the phthalocyanine, temperature, carrier gas speed, and other process parameters. Possible MEMS applications of thus fabricated nanolayers are discussed.
Keywords—carbon nanotubes,phthalocyanines, Raman, spray pyrolysis, TEM.
Influence of the Cooling Environment on Cutting Temperature and Specific Energy when Turning AISI 4340 Steel
Abstract—Temperature monitoring and controlling is a critical aspect influencing the technical and economic success of metal cutting operations owing to the fact that it affects both the quality of the machined component and the performance of the cutting tool. The aim of this work is to investigate the influence of the cutting parameters on tool temperature when turning AISI 4340 steel under three cooling environments: flooding, minimal quantity lubrication and dry cutting. In addition to that, the specific cutting energy required under each cooling environment was measured using a modified impact testing machine, thus allowing the estimate of the temperature associated with the chip formation mechanism. Furthermore, it is aimed at verifying whether this test can replace force measurement using a dynamometer. The findings indicate that the lowest tool temperature was achieved under flood cooling, followed by minimum quantity lubrication and dry cutting. Inversely, lowest specific cutting energy was obtained when dry cutting, followed by minimum quantity lubrication and flooding, thus suggesting that the higher temperatures achieved under dry cutting aid the softening of the work material and the reduction of its shear strength.
Keywords—AISI 4340 steel, specific cutting energy, temperature, turning.
Abstract— The successful application of catamaran hull form as passenger carriers has been well-known since the last 30 years. It is later extended to the development of fishing vessels and the reason behind this is attributed to safety criteria and wider deck-space which can be offered by the catamaran. It is also in connection with the handicaps of monohull fishing vessels, in terms of stability and seakeeping performance which can be improved by the introduction of catamaran forms. Recent situation on the rare and expensive fossil fuels have caused the fishermen into deep trouble hence most of them tend to be deprived if there is no anticipation taken to help them. The current paper describes a systematic investigation into the way to reduce (if not possible to replace completely) the use of fossil fuels on a catamaran fishing vessel. The study is focused on the use of diesel engine, sail and solar power on individual application as well as the combination of them. The implication to the final cost of the vessel, however, is negligible. It is discovered that the use of diesel engine could be replaced by the use of sail and solar power for individual basis. A combination of those power sources is found to be more appropriate in terms of stability and capacity of fishing holds. The investigation is extended to the evaluation of energy efficiency design index (EEDI), a compulsory criterion for measuring marine pollution made by the international maritime organization (IMO) and applied for ocean-going vessels. It is considered for fishing vessels because this type of vessel is thousands in number and most of them use engine together with fossil fuels hence there is strong potency to pollute air and the environment.
Keywords— Catamaran, fishing vessel, stability and seakeeping, power estimation, energy efficiency.