Experimental and estimated determination of mechanical characteristics of 3D printed ABS plastic samples under tension

The paper introduces the results of an experimental study of the mechanical characteristics of 3D printed ABS plastic ABSplus-P430 samples under tension. These 3D printed samples differ in the orientation of the material layers, formed by the position of the samples when printed, and the print raster pattern. During the tests, the material showed isotropic properties in terms of Young’s modulus and anisotropic properties for elongation at break, yield strength, and ultimate strength. We revealed that the print orientation relative to the direction of the applied load significantly affects the strength of the tested samples. Using the obtained test results, the specified parameters of the bilinear model of the material were identified by performing a series of computational studies using computer finite element models of material samples. The found parameters of the bilinear model of the material can be used to carry out computational estimation of the strength and bearing capacity of ABS plastic products manufactured by 3D printing. The results obtained also make it possible to develop recommendations for the orientation of products in the printing area according to the criterion of ensuring the greatest strength, taking into account the loading mode of the product.

Can crop phenology and plant height be channelized to improvise wheat productivity in diverse production environments?

Non-grain parameters like height, flowering and maturity should also be tried to break yield plateau in wheat. This study explores such possibilities by analysing performance of released and pre-released varieties evaluated in ten diverse production environments of India during the period 2000-2020. Regression analysis supports relevance of such non-grain determinants in grain yield under every environment but magnitude of impact can vary. Collective contribution of non-grain parameters can be high in a production environment where growth condition is most favourable for wheat growth and every factor is important in such situations. They contribute less in the environments engrossed with abiotic stress and merely one or two factors can be earmarked for selection. Besides yield, this selection strategy can also enhance grain weight in certain environments. At a time when selection for grain attributes is not providing further push; it would be worth trying to explore these non-grain field indicators as selection strategy for further advancement in productivity and grain weight of bread wheat.

Strength and Weakness Characteristics of Using Polymer Based Alternative to Steel Mesh In Underground Coal Mine Strata

Nowadays a viable development of polymer based material as an alternative to the steel mesh material has been increased at a notable amount for providing enough support in the underground roadways. This feasibility study done on the development of using polymer based alternative is related with both of the chemical & physical properties of the selected material. If the polymer alternative has a considerable amount of capability to tolerate all the physical & material constraints equal to or above the normal steel mesh, then the possibility of using polymeric alternatives have been increased at a greater extent. For this reinforcement test, an experiment practice would be done by comparing the mechanical properties of the steel mesh with the polymeric material such as modulus property, elongation-at-break, yield stress etc. After that, a suitable polymer based alternative will be applied for underground roadway support in upcoming days.

Vacuum-UV induced DNA strand breaks – influence of the radiosensitizers 5-bromouracil and 8-bromoadenine

VUV induced strand breaks in oligonucleotides modified by 5-Bromouracil (5-BrU) and 8-Bromoadenine (8-BrA) is quantified. While 5-BrU is an efficient photosensitizer, 8-BrA does not increase the strand break yield.

The Influence of DNA Configuration on the Direct Strand Break Yield

Purpose. To study the influence of DNA configuration on the direct damage yield. No indirect effect has been accounted for.Methods. The GEANT4-DNA code was used to simulate the interactions of protons and alpha particles with geometrical models of the A-, B-, and Z-DNA configurations. The direct total, single, and double strand break yields and site-hit probabilities were determined. Certain features of the energy deposition process were also studied.Results. A slight increase of the site-hit probability as a function of the incident particle linear energy transfer was found for each DNA configuration. Each DNA form presents a well-defined site-hit probability, independently of the particle linear energy transfer. Approximately 70% of the inelastic collisions and ~60% of the absorbed dose are due to secondary electrons. These fractions are slightly higher for protons than for alpha particles at the same incident energy.Conclusions. The total direct strand break yield for a given DNA form depends weakly on DNA conformation topology. This yield is practically determined by the target volume of the DNA configuration. However, the double strand break yield increases with the packing ratio of the DNA double helix; thus, it depends on the DNA conformation.

Mechanical, Thermal and Morphological Properties of Poly(butylene Succinate) Filled with Bio-Functional Filler from Eggshell Waste

In this work, calcium carbonate derived from eggshell, in a form of eggshell powder (ESP) with an average particle size of 13.96 μm, was used as bio-reinforcing filler for poly (butylene succinate), (PBS). The effect of ESP content on mechanical, thermal, and morphological properties of ESP filled PBS was investigated. The ESP/PBS composites were prepared at various ESP contents of 10, 20, 30 and 40 wt.%. It was found that incorporation of ESP into PBS matrix resulted in an improvement of Youngs modulus but it resulted in a decrease of tensile stress at break, yield strength and impact strength of the composite. In addition, increasing ESP content did not significantly influence decomposition temperature and melting temperature of PBS matrix. On the other hand, with increasing ESP content, crystallization temperature of the composite decreased but degree of crystallinity increased. Fracture surface morphology of the PBS composites obtained from scanning electron microscope indicated agglomeration and poor distribution of ESP within the composite matrix. Partial adhesion between ESP surface and PBS matrix was observed as well.

Study of PP/nano-TiO2 Composites on Plastic Mechanism after Microwave Irradiation

Prepared PP/ nano-TiO2 composites by MeltExtrusion,according to compare the changing of their elongation at break、yield strength and tensile strength before and after microwave irradiation, using SEM、TEM and FIR to observe the change，then could obtain that on one side microwave irradiation could vibration the group of molecular chain, friction produce energy makes composites degradation, on the other side, it improves the distribution of inorganic particle in matrix, two phase compatibility and interface combination, from that ,we get the plastic mechanism of microwave irradiation.