Benefiting from biomimicry through 3D printing to enhance mechanical properties of polymeric structures: Simulation approach

© 2023 Aberystwyth University.Numerous biological structures have intricate compositional arrangements, well-organised pieces and stronger mechanical qualities than the materials that make them up. Therefore, this study focused on enhancing the mechanical characteristics of three-dimensional (3D)-printed acrylonitrile butadiene styrene (ABS) structures. Selected parts/systems of three natural (animal/plant) materials were designed/modelled and analysed to mimic their natural lattice structures (biomimicry), using CATIA V5 and finite element method/Ansys software. The simulation results showed that the tensile strength of the biomimetic-designed beetle increased by 13.63%, the bending strength of the biomimetic lotus stem improved by 2.00 and 19.86% in simple and three-point bending tests, and the compressive strength of biomimetic trabecular bone enhanced by 87.59%, when compared with their conventional structures. Also, the biomimetic design recorded 10.00% higher compressive strength than a fillet design and nearly 64.00% than the repeated pattern. It was evident that biomimetic designs enhanced the mechanical properties of all the 3D-printed ABS structures

Effect of sowing time on productivity and economics of okra (Abelmoschus esculentus) under semi-arid conditions

An investigation to study the effect date of sowing on productivity of okra (Abelmoschus esculentus L. Moench) cv. Gujarat Okra 2 was carried out at the five farmer's field at Panchmahals district of central Gujarat under on farm trial during 2011-12 and 2012-13. The maximum plant height (97.15 cm) at the time of first flowering, number of branches (4.10), pod length (11.55 cm), pod diameter (14.20 cm), number of pods/plant (9.25), pod weight (32.40g) and fruit yield (10.41 tonnes/ha) were recorded in T2. The minimum time (60.50 days) for flowering was recorded in T1. The maximum gross return (Rupees 116 265) and net return (Rupees 86 980) was recorded in T1 followed by T3 (Rupees 87 590, 58 390) and (Rupees 75 895, 45 778) in T2. The maximum B: C ratio (3.97) was recorded in T1 followed by T3 and T2. The B: C ratio is one of most important aspect for selection of particular crop and season by the farmers to maximize the productivity and net return. The farmers of adjoining area have realized the effect of sowing time on productivity and net return and have adopted this technology

Effect of spacing and nitrogen levels on performance of hybrid napier in semiarid ecosystem of Gujarat

The present study was undertaken during 2011-12 at Krishi Vigyan Kendra, Panchmahal to find out the effect of spacing and nitrogen levels on performance of hybrid napier in semi-arid ecosystem of Gujarat. The results revealed that the different spacing could not exert significant effect on the plant height, whereas nitrogen levels significantly influenced the plant height. The application of higher dose of nitrogen (200 kg/hr) significantly exhibited higher plant (132.25 cm) followed by 175 and 150 kg/ha N. Tillers/clump and leaf stem ratio was influenced significantly owing to different spacing and levels of nitrogen. The highest leaf stem ratio and more number of leaves/stem were recorded with the spacing of 75 cm × 60 cm and application of 200 kg/ha. The green fodder yield was increased significantly with increasing the spacing and levels of nitrogen. Interaction effect of adoption of spacing and levels of nitrogen indicate that the treatment combination having spacing 75 cm × 60 cm and nitrogen level 200 kg/ha recorded significantly highest green fodder yield. Higher gross returns, net return with maximum benefit cost ratio were recorded when the clumps were planted at the spacing 75 cm × 60 cm with of 200 kg/ha N

High spin band structures in doubly-odd 194^{194}Tl

The high-spin states in odd-odd $^{194}$Tl nucleus have been studied by populating them using the $^{185,187}$Re($^{13}$C, xn) reactions at 75 MeV of beam energy. $\gamma-\gamma$ coincidence measurement has been performed using the INGA array with a digital data acquisition system to record the time stamped data. Definite spin-parity assignment of the levels was made from the DCO ratio and the IPDCO ratio measurements. The level scheme of $^{194}$Tl has been extended up to 4.1 MeV in excitation energy including 19 new gamma ray transitions. The $\pi h_{9/2} \otimes \nu i_{13/2}$ band, in the neighboring odd-odd Tl isotopes show very similar properties in both experimental observables and calculated shapes. Two new band structures, with 6-quasiparticle configuration, have been observed for the first time in $^{194}$Tl. One of these bands has the characteristics of a magnetic rotational band. The cranked shell model calculations, using a deformed Woods-Saxon potential, have been performed to obtain the total Routhian surfaces in order to study the shapes of the bands and the band crossing in $^{194}$Tl. The semiclassical formalism has been used to describe the magnetic rotational band.Comment: Accepted for publication in Physical Review

Observation of multiple doubly degenerate bands in ¹⁹⁵Tl

The High-spin states in 195 Tl, populated through the 185,187 Re( 13 C, xn) fusion evaporation reaction at the beam energy of 75 MeV, were studied using the Indian National Gamma Array (INGA). More than 50 new γ transitions have been placed in the proposed level scheme which is extended up to the excitation energy of ≈ 5.6 MeV and spin =22.5ħ . Two pairs of degenerate bands based on two different quasi-particle configurations have been identified in this nucleus indicating the first observation of such bands in an odd- A nucleus in A∼190 region and signify the first evidence of multiple chiral bands in a nucleus in this region. The total Routhian surface calculations predict triaxial shapes for both the configurations and thereby, support the experimental observation. The importance of multiple neutron holes in the i13/2 orbital and the stability of shapes for these two configurations have been discussed.Financial support of Department of Science & Technology, Govt. of India for clover detectors of INGA (Grant No. IR/S2/PF-03/2003-II) is greatfully acknowledged. One of the authors (S. Bhattacharya) acknowledges with thanks the financial support received as Raja Ramanna Fellowship from the Department of Atomic Energy, Govt. of India. T.R and Md. A.A acknowledge with thanks the financial support received as research fellows from the Department of Atomic Energy (DAE), Govt. of India

Cytisus scoparius link - A natural antioxidant

BACKGROUND: Recent investigations have shown that the antioxidant properties of plants could be correlated with oxidative stress defense and different human diseases. In this respect flavonoids and other polyphenolic compounds have gained the greatest attention. The plant Cytisus scoparius contains the main constituent of flavone and flavonals. The present study was undertaken to evaluate the in vitro antioxidant activities of extract of aerial part of Cytisus scoparius. METHODS: The plant extract was tested for DPPH (1, 1-diphenyl, 2-picryl hydrazyl) radical scavenging, nitric oxide radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, antilipid peroxidation assay, reducing power and total phenol content. RESULTS: The extract exhibited scavenging potential with IC(50 )value of 1.5 μg/ml, 116.0 μg/ml and 4.7 μg/ml for DPPH, nitric oxide and superoxide anion radicals. The values were found to lesser than those of vitamin C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of 104.0 μg/ml in lipid peroxidation induced by Fe(2+)/ ascorbate system in rat liver microsomal preparation. There is decrease in hydroxyl radical generation with IC(50 )value of 27.0 μg/ml when compared with standard vitamin E. The reducing power of the extract depends on the amount of extract. A significant amount of polyphenols could be detected by the equivalent to 0.0589 μg of pyrocatechol from 1 mg of extract. CONCLUSION: The results obtained in the present study indicate that hydro alcoholic extract of aerial part of Cytisus scoparius is a potential source of natural antioxidants

Effects of tranexamic acid on death, disability, vascular occlusive events and other morbidities in patients with acute traumatic brain injury (CRASH-3): a randomised, placebo-controlled trial

Background Tranexamic acid reduces surgical bleeding and decreases mortality in patients with traumatic extracranial bleeding. Intracranial bleeding is common after traumatic brain injury (TBI) and can cause brain herniation and death. We aimed to assess the effects of tranexamic acid in patients with TBI. Methods This randomised, placebo-controlled trial was done in 175 hospitals in 29 countries. Adults with TBI who were within 3 h of injury, had a Glasgow Coma Scale (GCS) score of 12 or lower or any intracranial bleeding on CT scan, and no major extracranial bleeding were eligible. The time window for eligibility was originally 8 h but in 2016 the protocol was changed to limit recruitment to patients within 3 h of injury. This change was made blind to the trial data, in response to external evidence suggesting that delayed treatment is unlikely to be effective. We randomly assigned (1:1) patients to receive tranexamic acid (loading dose 1 g over 10 min then infusion of 1 g over 8 h) or matching placebo. Patients were assigned by selecting a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was head injury-related death in hospital within 28 days of injury in patients treated within 3 h of injury. We prespecified a sensitivity analysis that excluded patients with a GCS score of 3 and those with bilateral unreactive pupils at baseline. All analyses were done by intention to treat. This trial was registered with ISRCTN (ISRCTN15088122), ClinicalTrials.gov (NCT01402882), EudraCT (2011-003669-14), and the Pan African Clinical Trial Registry (PACTR20121000441277). Results Between July 20, 2012, and Jan 31, 2019, we randomly allocated 12 737 patients with TBI to receive tranexamic acid (6406 [50·3%] or placebo [6331 [49·7%], of whom 9202 (72·2%) patients were treated within 3 h of injury. Among patients treated within 3 h of injury, the risk of head injury-related death was 18·5% in the tranexamic acid group versus 19·8% in the placebo group (855 vs 892 events; risk ratio [RR] 0·94 [95% CI 0·86-1·02]). In the prespecified sensitivity analysis that excluded patients with a GCS score of 3 or bilateral unreactive pupils at baseline, the risk of head injury-related death was 12·5% in the tranexamic acid group versus 14·0% in the placebo group (485 vs 525 events; RR 0·89 [95% CI 0·80-1·00]). The risk of head injury-related death reduced with tranexamic acid in patients with mild-to-moderate head injury (RR 0·78 [95% CI 0·64-0·95]) but not in patients with severe head injury (0·99 [95% CI 0·91-1·07]; p value for heterogeneity 0·030). Early treatment was more effective than was later treatment in patients with mild and moderate head injury (p=0·005) but time to treatment had no obvious effect in patients with severe head injury (p=0·73). The risk of vascular occlusive events was similar in the tranexamic acid and placebo groups (RR 0·98 (0·74-1·28). The risk of seizures was also similar between groups (1·09 [95% CI 0·90-1·33]). Interpretation Our results show that tranexamic acid is safe in patients with TBI and that treatment within 3 h of injury reduces head injury-related death. Patients should be treated as soon as possible after injury. Funding National Institute for Health Research Health Technology Assessment, JP Moulton Charitable Trust, Department of Health and Social Care, Department for International Development, Global Challenges Research Fund, Medical Research Council, and Wellcome Trust (Joint Global Health Trials scheme)