Analysis of Shrinkage Compensation Factor (SCF) of FDM uPrint SE for Accuracy Enhancement

This paper scrutinizes the shrinkage of a component manufactured using Additive Manufacturing (AM) and emphasizes mainly on the change in dimensions of an AM component after printing. The physical model can be easily manufactured by having the CAD data in STL format for real time AM. However, deviation of product size in CAD model transforming to physical model will be existing due to the deformation of the material mainly because of shrinkage. So here an analysis is carried out to find the optimal shrinkage compensation factor (SCF) of the part manufactured by Fusion Deposition Modelling (FDM) machine which uses ABS P430 as the base raw material. To achieve the latter a suitable model part is considered taking all the dimension and geometrical constraints which are essential for finding SCF and through regression analysis with the help of Co-ordinate Measuring Machine (CMM) and Solid Works modeling, SCF is calculated. Based on the experimental study, dimensional accuracy of the part significantly improved after applying the SCF value of 0.068% which is assumed to be constant in all directions

Comparative study of the antioxidant and reactive oxygen species scavenging properties in the extracts of the fruits of Terminalia chebula, Terminalia belerica and Emblica officinalis

<p>Abstract</p> <p>Background</p> <p>Cellular damage caused by reactive oxygen species (ROS) has been implicated in several diseases, and hence natural antioxidants have significant importance in human health. The present study was carried out to evaluate the <it>in vitro </it>antioxidant and reactive oxygen species scavenging activities of <it>Terminalia chebula</it>, <it>Terminalia belerica </it>and <it>Emblica officinalis </it>fruit extracts.</p> <p>Methods</p> <p>The 70% methanol extracts were studied for <it>in vitro </it>total antioxidant activity along with phenolic and flavonoid contents and reducing power. Scavenging ability of the extracts for radicals like DPPH, hydroxyl, superoxide, nitric oxide, hydrogen peroxide, peroxynitrite, singlet oxygen, hypochlorous acid were also performed to determine the potential of the extracts.</p> <p>Results</p> <p>The ability of the extracts of the fruits in exhibiting their antioxative properties follow the order <it>T. chebula </it>><it>E. officinalis </it>><it>T. belerica</it>. The same order is followed in their flavonoid content, whereas in case of phenolic content it becomes <it>E. officinalis </it>><it>T. belerica </it>><it>T. chebula</it>. In the studies of free radicals' scavenging, where the activities of the plant extracts were inversely proportional to their IC₅₀values, <it>T. chebula </it>and <it>E. officinalis </it>were found to be taking leading role with the orders of <it>T. chebula </it>><it>E. officinalis </it>><it>T. belerica </it>for superoxide and nitric oxide, and <it>E. officinalis </it>><it>T. belerica </it>><it>T. chebula </it>for DPPH and peroxynitrite radicals. Miscellaneous results were observed in the scavenging of other radicals by the plant extracts, viz., <it>T. chebula </it>><it>T. belerica </it>><it>E. officinalis </it>for hydroxyl, <it>T. belerica </it>><it>T. chebula </it>><it>E. officinalis </it>for singlet oxygen and <it>T. belerica </it>><it>E. officinalis </it>><it>T. chebula </it>for hypochlorous acid. In a whole, the studied fruit extracts showed quite good efficacy in their antioxidant and radical scavenging abilities, compared to the standards.</p> <p>Conclusions</p> <p>The evidences as can be concluded from the study of the 70% methanol extract of the fruits of <it>Terminalia chebula</it>, <it>Terminalia belerica </it>and <it>Emblica officinalis</it>, imposes the fact that they might be useful as potent sources of natural antioxidant.</p

Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

Irregularity-based image regions saliency identification and evaluation

The file attached to this record is the author's final peer reviewed version. The publisher's final version of record can be found by following the DOI.Saliency or Salient regions extraction form images is still a challenging field since it needs some understanding for the image and the nature of the image. The technique that is suitable in some application is not necessarily useful in other application, thus, saliency enhancement is application oriented. In this paper, a new technique of extracting the salient regions from an image is proposed which utilizes the local features of the surrounding region of the pixels. The level of saliency is then decided based on the global comparison of the saliency-enhanced image. To make the process fully automatic a new Fuzzy-Based thresholding technique has been proposed also. The paper contains a survey of the state-of-the-art methods of saliency evaluation and a new saliency evaluation technique was proposed

Analysis of Shrinkage Compensation Factor (SCF) of FDM uPrint SE for Accuracy Enhancement

This paper scrutinizes the shrinkage of a component manufactured using Additive Manufacturing (AM) and emphasizes mainly on the change in dimensions of an AM component after printing. The physical model can be easily manufactured by having the CAD data in STL format for real time AM. However, deviation of product size in CAD model transforming to physical model will be existing due to the deformation of the material mainly because of shrinkage. So here an analysis is carried out to find the optimal shrinkage compensation factor (SCF) of the part manufactured by Fusion Deposition Modelling (FDM) machine which uses ABS P430 as the base raw material. To achieve the latter a suitable model part is considered taking all the dimension and geometrical constraints which are essential for finding SCF and through regression analysis with the help of Co-ordinate Measuring Machine (CMM) and Solid Works modeling, SCF is calculated. Based on the experimental study, dimensional accuracy of the part significantly improved after applying the SCF value of 0.068% which is assumed to be constant in all directions