Lean six-sigma implementation in an automobile axle manufacturing industry: A case study

Continuous improvement in the manufacturing industries is the prime requirement to make the organization profitable. Lean manufacturing and six sigma are old techniques to improve the production of the industry by eliminating waste. These tools help the industry to grow worldwide in the competitive environment. This paper is based on the case study of a well-known automobile transmission components manufacturing industry. This industry manufactures about 33 types of axles for different vehicles and was facing the problem of rejection in one of its rear axle components. The industry was losing Rs. 7,33,000/- every month due to rejection of this rear axle. Lean six sigma (LSS) was the tool implemented to find and eliminate wastages. The current state map was made for this product by using historical three months data from the industry. The layout of the shopfloor was changed to reduce the transportation of the product and to manage the space for best utilization. 5S was implemented to make everything easily assessable. Drastic improvements have been achieved after the successful implementation of LSS like the rejection rate was reduced from 10.4% to 3.20 %. The shop floor area for processing the axles has been reduced from 252 m2 to 90 m2 after change in layout. The distance travelled by the material was reduced from 4050 m to 809 m. The sigma level was also improved from 3.34 to 3.94. The lead time was reduced from 12 days to 11 days.info:eu-repo/semantics/publishedVersio

Raman and Mössbauer spectroscopic studies of tungsten doped Ni–Zn nano ferrite

In this study, tungsten substituted Ni-Zn nano ferrites of the composition Ni0.5Zn0.5WxFe2−xO4 with x = 0.0, 0.2, 0.4 have been synthesized by a co-precipitation method. The prepared samples were pre-sintered at 850 °C and then annealed at 1000 °C for 3 h each. The structural, morphological, optical and magnetic properties of these samples were studied by using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS) and Mössbauer spectroscopy (MS). XRD revealed the formation of spinel single-phase structure with an average crystallite size of 53–60 nm. Fourier transform infrared spectroscopy show two prominent peaks primarily due to the tetrahedral and octahedral stretching vibrations in the range of 400–600 cm−1. Raman spectra indicate first order three Raman active modes; (A1 g + Eg + T2 g) at around 688, 475 and 326 cm−1. Mössbauer spectroscopy reveals that substitution of W3+ for Fe3+ cation results in reduction of total magnetic moment and consequently the net magnetization

Review—Metal Oxide Chemoresistive Gas Sensing Mechanism, Parameters, and Applications

The economic growth of any country depends upon the MSMEs as it plays a vital role in GDP and employment. The transportation is considered as the lifeline of the country. Hence due to developing countries, the industries and vehicles are continuously increasing to fulfil industrial or domestic requirements. But unfortunately, industries and vehicles emit harmful gases as exhaust to the environment. Which directly or indirectly impact the human health. Fresh and clean air is the prime need of the society. Hence the monitoring of different gas concentrations in the environment is very essential to take preventive steps to control air pollution. The traditional method of monitoring the air quality is very expensive, hence most of the countries have limited air monitoring stations. In the field of nanotechnology, scientists have developed different types of soft metal oxide materials that are capable of sensing different gases at low concentrations and can work in different environmental conditions. For the last 10 years, ferrite-based sensors have the primarily used to detect harmful gases, and pollutants from vehicle exhaust, and environmental pollution monitoring. These soft ferrites have excellent electrical and magnetic properties that can also be tuned according to the requirement of the sensor to increase sensitivity and selectivity. The tuning of ferrite sensors depends upon synthesis technique, optimizing preparation conditions, sintering temperatures, operating temperatures, dopant concentration, etc This paper is based on a deep study of the synthesis techniques of nano-ferrites, different types of gas sensors, gas sensing mechanisms, parameters, and application of chemo-resistive metal oxide gas sensors. The key parameters for the ferrite gas sensors are phase formation, crystallite size, grain size, surface area, selectivity, dopants, sensitivity, gas concentration, operating temperature, and response/recovery time. This review paper also includes the study of different researchers to find the impact of high concentrations of gases like hydrogen (H _2 ), carbon monoxide (CO), carbon dioxide (CO _2 ), oxygen (O _2 ), ethylene glycol ${{({CH}}_{2}{OH})}_{2},$ methane (CH _4 ), ammonia (NH _3 ) liquid petroleum gas (LPG), acetylene (C _2 H _2 ), and nitrogen oxides (NOx) in the environment and the metal oxide materials selected for the sensor application

Investigation of structural, optical, magnetic and electrical properties of tungsten doped Ni Zn nano-ferrites

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