Experimental studies on the energy absorption capacity of axially compressed metal tubes

Impact energy absorbers are expendable mechanical structural elements, which are brought into action to dissipate the kinetic energy in the event of an unwanted collision. These act as mechanical fuses to limit the loads, which may act on the main structure immediately after a collision. The use of aluminium tubes and tubular structures for use as impact energy absorbers in different engineering applications is encouraging. This is because of their ready availability in different cross sections and sizes, and also has high energy absorption capacity under quasi-static and dynamic loads. In this present study, experiments are conducted on circular aluminium tubes under quasi-static, axial compression. The different modes of deformation of these tubes are examined in two separate cases. Case 1: when the tubes compressed axially between a flat platen and shaped dies of different radii. Case 2: when the tubes compressed axially between two flat platens. Dies of different radii are used to evaluate the efficient mode of deformation. The energy absorption capacity under quasi-static loading conditions is evaluated in the above cases to evaluate the energy absorption capacity and to compare the energy absorption of aluminium tubes based on the different deformation modes. The results of the study are useful in the design of impact energy absorbers © IAEME Publicatio

Evaluation of fungal pathogens, Fusarium semitectum Berk. and Ravenel and Hirsutella thompsonii Fisher against red spider mite, Tetranychus neocaledoni-cus (Andre) of okra under laboratory and greenhouse conditions

Efficacy of fungal pathogens, Fusarium semitectum Berk. and Ravenel and Hirsutella thompsonii Fisher was evaluated against red spider mite, Tetranychus neocaledonicus (Andre) of okra under laboratory and greenhouse conditions. Among the treatments evaluated under laboratory conditions, the highest mortality of 78.20 and 88.34 percent adults and immatures, respectively was recorded at 2.10 x 109 spores per ml of F. semitectum, whereas it was 82.05 and 92.31 per cent adults and immatures, respectively in case of H. thompsonii at 4.60 x 108 spores per ml. Among the twelve treatments evaluated under greenhouse conditions, H. thompsonii 4.60 x 108 spores per ml, F. semitectum 2.10 x 109 spores per ml + H. thompsonii 4.60 x 108 spores per ml, H. thompsonii 4.60 x 108 spores per ml + dicofol 0.025% and F. semitectum 2.10 x 109 spores per ml + H. thompsonii 4.60 x 108 spores per ml + dicofol 0.025% were found to be on par with each other with a cumulative percent mortality of 81.20, 81.48, 81.21 and 82.59 percent, respectively. By testing the field efficacy of F. semitectum and H. thompsonii against T. neocaledonicus, these fungal pathogens can be used as potential biocontrol agents for the sustainable management of mites on okra. Hence the present study evaluates the potentiality of F. semitectum for the management of T. neocaledonicus by comparing with the well-known acaricidal fungus, H. thompsonii

Biochemical investigations on vigour enhancement in aged seeds upon seed priming in onion

Loss in seed quality that occurs during all process, from maturation in the field to storage, leads to seed deterioration. Storage of onion seeds under ambient, hot and humid conditions is very problematic since these conditions deteriorate seed quality faster. Seed deterioration is associated with many metabolic defects that occur due to changes in enzymes and protein levels. This deterioration can be rectified to the extent possible by the technique of seed priming. The results clearly indicated that priming will restore the lost seed vigour in aged seeds due to reactivation of enzyme activity in old seeds. The germination percentage improved from 60% to 79.5% and 72.5% in GA3 and hydroprimed, respectively. Priming will also restore the lost seed vigour in aged seeds due to reactivation of proteins in old seeds and expression of these proteins in priming treatments are related to priming induced proteins in contrast to their absence in the aged seeds which are necessary for germination and longevity of seeds

Interplay of non-covalent interactions in ribbon-like guanosine self-assembly : a NMR crystallography study

A NMR crystallography study shows how intermolecular NH...O, NH...N, OH...N, OH...O and CH–π interactions stabilize the ribbon-like supramolecular structures of three different guanosine derivatives; guanosine dihydrate (G), 3/, 5/–O– dipropanolyl deoxyguanosine (dGC(3)2) and 3/, 5/ –O– isopropylideneguanosine hemihydrate (Gace). Experimental solid-state 1H NMR spectra obtained at 20 T using fast Magic-Angle Spinning (MAS), here at 75 kHz, are presented for a dihydrate of G. For each guanosine derivative, the role of specific interactions is probed by means of NMR chemical shifts calculated using the Density Functional Theory (DFT) Gauge-Including Projector-Augmented Wave (GIPAW) approach for the full crystal and extracted isolated single molecules. Specifically, the isolated molecule to full crystal transformations result in net changes in the GIPAW calculated 1H NMR chemical shifts of up to 8 ppm for OH...O, up to 6.5 ppm for NH...N and up to 4.6 ppm for NH...O hydrogen bonds; notably, the presence of water molecules in G and Gace reinforces the molecular stacking through strong OH...O hydrogen bonds. The sugar conformations are markedly different in G, dG(C3)2 and Gace, and it is shown that the experimental 13C solid-state NMR chemical shift at the C8 position is a reliable indicator of a ‘syn’ (> 135 ppm) or ‘anti’ (< 135 ppm) conformer

Determination of a complex crystal structure in the absence of single crystals : analysis of powder X-ray diffraction data, guided by solid-state NMR and periodic DFT calculations, reveals a new 2′-deoxyguanosine structural motif

Derivatives of guanine exhibit diverse supramolecular chemistry, with a variety of distinct hydrogen-bonding motifs reported in the solid state, including ribbons and quartets, which resemble the G-quadruplex found in nucleic acids with sequences rich in guanine. Reflecting this diversity, the solid-state structural properties of 3′,5′-bis-O-decanoyl-2′-deoxyguanosine, reported in this paper, reveal a hydrogen-bonded guanine ribbon motif that has not been observed previously for 2′-deoxyguanosine derivatives. In this case, structure determination was carried out directly from powder XRD data, representing one of the most challenging organic molecular structures (a 90-atom molecule) that has been solved to date by this technique. While specific challenges were encountered in the structure determination process, a successful outcome was achieved by augmenting the powder XRD analysis with information derived from solid-state NMR data and with dispersion-corrected periodic DFT calculations for structure optimization. The synergy of experimental and computational methodologies demonstrated in the present work is likely to be an essential feature of strategies to further expand the application of powder XRD as a technique for structure determination of organic molecular materials of even greater complexity in the future

G4-Quartet·M+Borate Hydrogels

The ability to modulate the physical properties of a supramolecular hydrogel may be beneficial for biomaterial and biomedical applications. We find that guanosine (G 1), when combined with 0.5 equiv of potassium borate, forms a strong, self-supporting hydrogel with elastic moduli >10 kPa. The countercation in the borate salt (MB(OH)4) significantly alters the physical properties of the hydrogel. The gelator combination of G 1 and KB(OH)4 formed the strongest hydrogel, while the weakest system was obtained with LiB(OH)4, as judged by 1H NMR and rheology. Data from powder XRD, 1H double-quantum solid-state magic-angle spinning (MAS) NMR and small-angle neutron scattering (SANS) were consistent with a structural model that involves formation of borate dimers and G4·K+ quartets by G 1 and KB(OH)4. Stacking of these G4·M+ quartets into G4-nanowires gives a hydrogel. We found that the M+ cation helps stabilize the anionic guanosine-borate (GB) diesters, as well as the G4-quartets. Supplementing the standard gelator mixture of G 1 and 0.5 equiv of KB(OH)4 with additional KCl or KNO3 increased the strength of the hydrogel. We found that thioflavin T fluoresces in the presence of G4·M+ precursor structures. This fluorescence response for thioflavin T was the greatest for the K+ GB system, presumably due to the enhanced interaction of the dye with the more stable G4·K+ quartets. The fluorescence of thioflavin T increased as a function of gelator concentration with an increase that correlated with the system’s gel point, as measured by solution viscosit

Modelling of E-Governance Framework for Mining Knowledge from Massive Grievance Redressal Data

With the massive proliferation of online applications for the citizens with abundant resources, there is a tremendous hike in usage of e-governance platforms. Right from entrepreneur, players, politicians, students, or anyone who are highly depending on web-based grievance redressal networking sites, which generates loads of massive grievance data that are not only challenging but also highly impossible to understand. The prime reason behind this is grievance data is massive in size and they are highly unstructured. Because of this fact, the proposed system attempts to understand the possibility of performing knowledge discovery process from grievance Data using conventional data mining algorithms. Designed in Java considering massive number of online e-governance framework from civilian’s grievance discussion forums, the proposed system evaluates the effectiveness of performing datamining for Big data

Modelling of e-Governance Framework for Mining Knowledge from Massive Grievance Redressal Data

With the massive proliferation of online applications for the citizens with abundant resources, there is a tremendous hike in usage of e-governance platforms. Right from entrepreneur, players, politicians, students, or anyone who are highly depending on web-based grievance redressal networking sites, which generates loads of massive grievance data that are not only challenging but also highly impossible to understand. The prime reason behind this is grievance data is massive in size and they are highly unstructured. Because of this fact, the proposed system attempts to understand the possibility of performing knowledge discovery process from grievance Data using conventional data mining algorithms. Designed in Java considering massive number of online e-governance framework from civilian’s grievance discussion forums, the proposed system evaluates the effectiveness of performing datamining for Big data

Enteral lactoferrin supplementation for very preterm infants: a randomised placebo-controlled trial

Background Infections acquired in hospital are an important cause of morbidity and mortality in very preterm infants. Several small trials have suggested that supplementing the enteral diet of very preterm infants with lactoferrin, an antimicrobial protein processed from cow's milk, prevents infections and associated complications. The aim of this large randomised controlled trial was to collect data to enhance the validity and applicability of the evidence from previous trials to inform practice. Methods In this randomised placebo-controlled trial, we recruited very preterm infants born before 32 weeks' gestation in 37 UK hospitals and younger than 72 h at randomisation. Exclusion criteria were presence of a severe congenital anomaly, anticipated enteral fasting for longer than 14 days, or no realistic prospect of survival. Eligible infants were randomly assigned (1:1) to receive either enteral bovine lactoferrin (150 mg/kg per day; maximum 300 mg/day; lactoferrin group) or sucrose (same dose; control group) once daily until 34 weeks' postmenstrual age. Web-based randomisation minimised for recruitment site, gestation (completed weeks), sex, and single versus multifetal pregnancy. Parents, caregivers, and outcome assessors were unaware of group assignment. The primary outcome was microbiologically confirmed or clinically suspected late-onset infection (occurring >72 h after birth), which was assessed in all participants for whom primary outcome data was available by calculating the relative risk ratio with 95% CI between the two groups. The trial is registered with the International Standard Randomised Controlled Trial Number 88261002. Findings We recruited 2203 participants between May 7, 2014, and Sept 28, 2017, of whom 1099 were assigned to the lactoferrin group and 1104 to the control group. Four infants had consent withdrawn or unconfirmed, leaving 1098 infants in the lactoferrin group and 1101 in the sucrose group. Primary outcome data for 2182 infants (1093 [99·5%] of 1098 in the lactoferrin group and 1089 [99·0] of 1101 in the control group) were available for inclusion in the modified intention-to-treat analyses. 316 (29%) of 1093 infants in the intervention group acquired a late-onset infection versus 334 (31%) of 1089 in the control group. The risk ratio adjusted for minimisation factors was 0·95 (95% CI 0·86–1·04; p=0·233). During the trial there were 16 serious adverse events for infants in the lactoferrin group and 10 for infants in the control group. Two events in the lactoferrin group (one case of blood in stool and one death after intestinal perforation) were assessed as being possibly related to the trial intervention. Interpretation Enteral supplementation with bovine lactoferrin does not reduce the risk of late-onset infection in very preterm infants. These data do not support its routine use to prevent late-onset infection and associated morbidity or mortality in very preterm infants. Funding UK National Institute for Health Research Health Technology Assessment programme (10/57/49)