The concepts of lean manufacturing operations and sustainability are congruent in nature, marked by the facet of improving organizational efficiency. However, only difference lies in the definition ...of waste. This definition is given a new dimension by sustainability by incorporating the extensive scope of reductions in the environmental consequences in the form of 6R (reduce, reuse, recycle, recover, redesign and remanufacture); which requires a consolidated integrated approach. Therefore, as to affirm the requirement, a systematic literature review has been carried out which scrutinized previous researches in view of their originality, methodology, objectives and limitations. Based on this literature study, 25 most related approaches (lean and sustainable integrated approaches) were selected and their originality was investigated. Investigation revealed that few research articles are integrating lean and sustainable approaches. This study identifies the gap of the integration of lean practices with 6Rs and a framework was developed which implemented on the case study that carries ability to attain 6R based sustainable lean production systems. Because of more social and environmentally friendly atmosphere achieved through 6R based implementation, the results achieved are 50% decrease in heating cost by redesigning furnaces (from oil furnaces to gas furnaces), 36.33% improvement in value added time, 40.14% in lead-time and 22% reduction in labour utilization. This improvement indicates that use of proposed integrated framework is highly beneficial for any kind of manufacturing sector.
•Axial DOC contributes most for wiper inserts’ tool life while machining Inconel 625.•Adhesion, BUE, attrition and chipping are the main wear mechanisms at low axial DOC.•Wiper inserts’ feed/tooth ...contributes most for surface roughness of Inconel 625.•An extended work-hardened subsurface layer is seen for max. tool life condition.
Ni-based superalloy Inconel 625, despite its extensive applications (in aerospace, oil and gas, marine, chemical processing and alike industry) is categorized as difficult-to-cut material due to distinct thermal and physical characteristics. Incidentally, the use of novel multi radii insert (wiper) geometry, that is reported to provide extended machining capabilities for different materials and machining scenarios has not been found to be reported for this alloy. This work employs PVD coated carbide inserts with novel wiper edge geometry for face milling of Inconel 625 under dry cutting conditions. Cutting speed, feed per tooth and axial depth of cut have been taken as input variables and machining performance is evaluated in terms of tool life, tool wear analysis, material removed and surface integrity aspects (namely roughness and microhardness). Taguchi L8 array has been employed for experimentation phase followed by post experimental analysis. It is found that for tool life, axial depth of cut is the most significant factor with contribution of 45.43%. Maximum tool life of 42.8 min was achieved when machining was done employing lower values of feed (0.08 mm/tooth) and axial depth of cut (0.25 mm) with higher value of cutting speed (45 m/min). For the case of surface roughness, feed/tooth is found to be the most contributing factor (PCR 46.25%). Results are found to be correlating well with the cutting temperatures generated during the process. Experiments with minimum axial depth of cuts resulted in lesser temperatures and better output parameters in general. Review of the wear pattern via SEM analysis indicate adhesion, BUE, attrition and chipping to be the main wear mechanism in general except where higher axial depth of cut (0.5 mm) was employed that culminated in fracture. For the conditions where maximum tool life was obtained, a work-hardened layer was observed beneath the machined surface extending up to ∼400 μm depth. An indirect comparison of the results with other literature reported face milling scenarios of Inconel 625 (where other tool types are employed), seems to indicate the effectiveness of wiper inserts employed herein. The results are well explained and supported by the physical phenomenon involved.
According to the EU noise directive, the National Road Authority (NRA) in Ireland is responsible for generating noise models for all roads used by more than 8,000 vehicles per day. These noise models ...have to be updated every 5 years. Important inputs to noise model are digital terrain model (DTM), 3D building data, road width, road centre line, ground surface type and noise barriers. The objective of this research was to extract these objects and topographical information using nationally available datasets acquired from the Ordnance Survey of Ireland (OSI). The OSI uses ALS50-II LiDAR and ADS40 digital sensors for capturing ground information. Before exploiting the complementary nature of both datasets for information extraction, their planimetric and vertical accuracies were evaluated using independent ground control points. A new method was also developed for registration in case of any mismatch. DSMs from LiDAR and aerial images were used to find common points to determine the parameters of 2D conformal transformation.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> The developed method was also evaluated by the EuroSDR in a project which involved a number of partners. A combination of image classification techniques was used to extract information by the fusion of LiDAR and aerial images. The developed method has two phases, viz. object classification and object reconstruction. Buildings and vegetation were classified based on Normalized Difference Vegetation Index (NDVI) and a normalized digital surface model (nDSM). Holes in building segments were filled by object-oriented multiresolution segmentation. Vegetation that remained amongst buildings was classified using cues obtained from LiDAR. The building extents were extracted and assigned a single height value generated from LiDAR nDSM. The extracted height was verified against the ground truth data acquired using terrestrial survey techniques. The developed object extraction method was tested objectively in two independent areas namely the Test Area-1 and the Test Area-2. The results were thoroughly investigated by three different accuracy assessment methods using the OSI vector data. The acceptance of any developed method for commercial applications requires completeness and correctness values of 85% and 70% respectively. Accuracy measures obtained using the developed method of object extraction recommend its applicability for noise modelling.
The aim of this research is to extract objects i.e. buildings, trees and roads important for noise mapping but also for applications such as 3D city modelling, land cover classification, change ...detection and many others. Earlier research has focused on the extraction of these objects independently either from aerial imagery or LIDAR (Light Detection and Ranging) data. This paper however, focuses on the extraction of these objects by fusing the information captured by two independent sensors. A workflow has been developed for the extraction of these objects automatically utilizing intensity and height values from LIDAR and the NDVI (Normalized Difference Vegetation Index) from multispectral images. Major tasks include LIDAR data classification, segmentation and its integration with the information extracted from aerial images. Buildings are extracted first and this facilitates the extraction of other objects by refining the classification of LIDAR data. Results are evaluated and incorporated into a GIS system for further analysis.
Acquisitions and divestitures (A&D) are a part of the asset allocation strategy for oil and gas companies and are constantly evaluated on both a short and long-term basis. Oil and gas companies seek ...to acquire assets that maximize core competencies and increase shareholder value. Companies divest assets to raise funding for existing asset development or to acquire new assets more closely aligned with long-term strategic goals. Although acquisitions and divestitures can be beneficial for companies, they can significantly affect the workforce of companies involved in both sides of the transaction. This blog post will address the most common scenarios that oil and gas professionals will have to face, as well as tips for dealing with employment changes during A&Ds.
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There is a high demand of effective and eco-friendly corrosion inhibitor for industrial applications. In an attempt to prepare a benign and effective corrosion inhibitor for acidizing ...purpose, an imidazoline derivative, N-(2-(2-tridecyl-4,5-dihydro-1H-imidazol-1-yl)ethyl)tetradecanamide (NTETD) was synthesized from myristic acid and diethyleneamine. The characterization of the newly synthesized compound was done using 1H NMR, FTIR, and elemental analysis techniques. NTETD was examined as a corrosion inhibitor for low carbon steel in 15% HCl solution using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), linear polarization (LPR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDAX), atomic force spectroscopy (AFM), and X-ray photoelectron spectroscopy (XPS) techniques. It was found that, the optimum concentration of NTETD is 300 mg/L. With this concentration, inhibition efficiency above 93% is achievable. Results from PDP show that, NTETD acted as a mixed type corrosion inhibitor but with principal effect on cathodic corrosion half reactions. The calculated value of the adsorption-desorption equilibrium constant (1.015 × 103) reveals a strong bonding between NTETD molecules and the steel surface. The EDAX, FTIR, and XPS results confirm the adsorption of NTETD molecules on the steel surface. SEM and AFM results agree with experimental findings that NTETD is effective in corrosion mitigation of steel in 15% HCl solution. The possible corrosion inhibition mechanism by NTETD has been proposed.
Since the Paris Agreement, countries around the globe have been striving to achieve their carbon neutrality targets. However, because China has one of the largest economies in the world, to achieve ...its targeted carbon neutrality, the roles of foreign direct investment (FDI), technological innovation (TI), and trade are crucial. Therefore, this study aims to introduce the level of trade, renewable energy consumption (REC), and FDI from the years 1995–2017 as new determinants in promoting a sustainable environment in China. The study employs advanced panel methods based on slope homogeneity and a cross-sectional dependence test. The results confirm a cointegration relationship for all models in this study, suggesting that gross domestic product and FDI positively affect carbon emissions. By contrast, foreign trade, REC, and TI are inversely associated with carbon emissions. Moreover, according to Chinese provincial data, the joint term for FDI with REC and TI is negatively associated with carbon emissions. The policy implications of this study suggest that to achieve sustainable FDI, TI should be encouraged to mitigate the pollution caused by FDI. There is a dire need to implement green practices and eco-friendly policies at a national scale.
•Foreign direct investment and trade effect on CO2 emission is examined.•It employs robust panel methods suitable for the data.•GDP and foreign direct investment positively affect carbon emissions.•Foreign trade, renewable energy and technology are inversely associated with CO2.•Positive impact of FDI on CO2 is less in provinces with more innovation.
Smoke detection in Internet of Things (IoT) environment is a primary component of early disaster-related event detection in smart cities. Recently, several smoke and fire detection methods are ...presented with reasonable accuracy and running time for normal IoT environment. However, these methods are unable to detect smoke in foggy IoT environment, which is a challenging task. In this paper, we propose an energy-efficient system based on deep convolutional neural networks for early smoke detection in both normal and foggy IoT environments. Our method takes advantage of VGG-16 architecture, considering its sensible stability between the accuracy and time efficiency for smoke detection compared to the other computationally expensive networks, such as GoogleNet and AlexNet. Experiments performed on benchmark smoke detection datasets and their results in terms of accuracy, false alarms rate, and efficiency reveal the better performance of our technique compared to state-of-the-art and verifies its applicability in smart cities for early detection of smoke in normal and foggy IoT environments.
Urban soil is influenced by both the natural and anthropogenic factors. Their impacts, therefore, amend the concentration of heavy metals in urban soils. In this study, the concentration of selected ...heavy metals including Cu, Zn, Pb, Fe and Cr in urban soils was assessed in the megacity of Karachi, Pakistan. Variability of metal concentration across distinct urban land uses, and through seasonal interventions was used as an indicator of the factors involved. For spatial analysis, soil samples were collected from 30 different locations, belonging to 6 distinct land uses dominant in the megacity. For temporal investigations, the samples were collected in both pre-monsoon (PRM) and post-monsoon (POM) conditions. The results revealed that the mean concentrations were in the order Fe≫Zn>Pb>Cu>Cr, in both the seasons. Increase in concentration of Pb and Fe, after rain, seems to be the result of sinking of aerial metal and relocation by flood runoffs. The concentration of Cu and Zn decreased in the POM season possibly due to dilution by rainwater. The spatial variation in the concentration of Cu, Zn and Pb metals seemed to be the result of point sources and vehicle emissions. Fe, despite of its very high average concentration in soil, shows moderate spatial variation (Variance <50%) which indicates the non-point nature of its sources. Cu, Zn and Pb showed their common sources (through anthropogenic activities) and the relationship have been proved by both the multivariate and spatial analyses. However, Cr seemed to have least affected by anthropogenic activities due to weaker and/or no correlation.
Contemporary semiconducting ceramics, including zinc oxide, find applications in a variety of different fields. Its wurtzite crystal structure can accommodate various dopants, allowing extensive ...engineering to achieve desired properties. Different manufacturing methods such as the sol–gel method, microemulsion technique, chemical vapor deposition (CVD), thermal decomposition, etc. result in different morphologies and yield a range of particle sizes that affect its optical, photocatalytic, and semiconducting properties. Indeed, it has been reported that the introduction of dopants can enhance the dye degradation and photocatalytic properties of ZnO.
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