473 research outputs found
Evaluation of Novel Gerbera (Gerbera jamesonii Bolus ex. Hooker F.) Hybrids for Flower Quality Traits under Naturally-Ventilated Polyhouse
The present study was carried out to evaluate performance of two gerbera hybrids IIHR 3-34 and IIHR 8-45 along with their parents and check, for flower quality traits under naturally-ventilated polyhouse in Randomized Block Design, in the years 2014-15 and 2015-16. Both the hybrids had been developed through the half-sib method of breeding with IIHR-3 and IIHR-1, respectively, as parents. Data for the two years were pooled and analyzed statistically. Significant differences were observed in the quality traits studied. In the case of both hybrids IIHR 3-34 and IIHR 8-45, most of the quantitative traits were found to be on par with the check variety, Elite. They had novel flower colour (68D as per RHS Colour Chart), Red Purple Group (IIHR 3-34) and 50A Red Group (IIHR 8-45), with double type of flowers. These are suitable for cut-flower and flower arrangement purposes. These hybrids will prove useful for developing more gerbera hybrids with novel traits
Cl, K and Ni induced reactions to synthesis SHN 273Rg
267-270We have studied chlorine (Cl), potassium (K) and Nickel (Ni) induced reactions in the synthesis of 273Rg. We have studied the compound nucleus formation probability, survival probability and evaporation residue cross sections to synthesize superheavy element (SHN) 273Rg. The selected projectile-target combinations to synthesis 273Rg are 35,37Cl + 238,236Pu, 39-41K + 234-232U and 63,64Ni + 210,209Bi. From the study of PCN, Psur and σevr we have identified that 35Cl+238Pu is the most suitable projectile-target combination to synthesize 273Rg. We have also compared the present work with the experimental values available in literature
Cluster radioactivity in superheavy nuclei 299-306122
Cluster radioactivity is an intermediate between alpha decay and spontaneous fission. It is also an exotic decay obtained in superheavy nuclei. When a cluster decay is detected in superheavy nuclei, the daughter nuclei is having near or equal to doubly magic nuclei. We have investigated cluster decay of isotopes of He, Li, Be, Ne, N, Mg, Si, P, S, Cl, Ar and Ca in the superhaevy nuclei region 299-306122. We have also compared the logarithmic half-lives of cluster decay with that of other models such as Univ [1], NRDX [2], UDL [3] and Horoi [4]. From this study it is concluded that cluster decay of 4He, 22Ne, 26Mg, 28Si 30Si, 34S, 40Ca and 46Ca are having shorter logarithmic half-lives compared to exotic cluster decay modes
Systematics of proton decay of actinides
255-262The phenomenon of proton emission from nuclear ground states limits the possibilities of the creation of more exotic proton rich nuclei that are usually produced by fusion-evaporation nuclear reactions. In the energy domain of radioactivity, proton can be considered as a point charge having highest probability of being present in the parent nucleus. Conclaves et al.1 studied the two-proton radioactivity of nuclei of mass number Aet al.2 reviewed the theories of proton emission to analyse the properties of nuclear matter. Maglione et al.3 analysed the proton emission from the some deformed nuclei. We have studied proton decay in almost all actinide nuclei. We have calculated the energy released during the proton decay (QP), penetration factor (P), and half-lives of proton decay. Proton decay half-lives are also longer than that of other decay modes such as alpha decay and spontaneous fission. To check the Geiger-Nuttal law for proton decay in actinide nuclei, we have plotted the logarithmic proton decay half-lives versus 1/sqrt(Q). The competition of proton decay with different decay modes such as alpha decay and spontaneous fission are also studied. We have also highlighted possible proton emitters with the corresponding energies and half-lives in the actinide region
Cl, K and Ni induced reactions to synthesis SHN 273Rg
We have studied chlorine (Cl), potassium (K) and Nickel (Ni) induced reactions in the synthesis of 273Rg. We have studied the compound nucleus formation probability, survival probability and evaporation residue cross sections to synthesize superheavy element (SHN) 273Rg. The selected projectile-target combinations to synthesis 273Rg are 35,37Cl + 238,236Pu, 39-41K + 234-232U and 63,64Ni + 210,209Bi. From the study of PCN, Psur and σevr we have identified that 35Cl+238Pu is the most suitable projectile-target combination to synthesize 273Rg. We have also compared the present work with the experimental values available in literature
Energy-absorption buildup factors and specific absorbed fractions of energy for bioactive glasses
In the present work, effective atomic numbers Zeff, energy-absorption buildup factors EABF and specific absorbed fractions of energy (Φ) for different bioactive glasses have been calculated in the present work. Geometric-Progression (G-P) fitting method was used for computation of EABF. The computed EABF is used to estimate the values of Φ. It is shown that the EABF and Φ are dependent on Zeff and mean free path. In addition, EABF and Φ were the largest for S4 and S7.The results in this work could be useful in choosing a suitable type of these glasses which in turn are able to resist possible radiation damages at human body and to determine the thickness and shape of the bioactive glasses needed
Fatigue behavior of a hybrid particles modified fiberglass/epoxy composite under a helicopter spectrum load sequence
ABSTRACT The fatigue life of a glass fiber reinforced plastic (GFRP) hybrid composite containing 9 wt.% of rubber microparticles and 10 wt.% of silica nanoparticles in the epoxy matrix, under a standard helicopter rotor spectrum load sequence was determined and observed to be about three times higher than that of GFRP with unmodified epoxy matrix. The underlying mechanisms for the observed improvements in spectrum fatigue life of GFRPhybrid composite are discussed. Recently, we have observed that the hybrid GFRP composite containing 9 wt. % of micron-rubber and 10 wt. %of nano-silica particles in the epoxy matrix exhibit enhanced constant amplitude fatigue life by about eight to ten times over that of GFRP composite with unmodified epoxy matrix INTRODUCTION EXPERIMENTAL Materials and Processing The complete details of materials used and the processing employed to manufacture the GFRP composites can be found in Manjunatha et al wt.% of CTBN rubber in the final resin, were all individually weighed, degassed and mixed together and a stoichiometric amount of curing agent. The atomic force microscope (AFM) phase image of the particles modified bulk epoxy polymer is shown in The silica particles of about 20 nm in diameter were somewhat agglomerated to give a 'necklace-type' structure with an average width of about 1 µm. The resin mixture was used to prepare the GFRP composite laminate by the 'Resin Infusion under Flexible Tooling' (RIFT) technique The mechanical properties of both GFRP-neat and GFRP-modified composites are shown in Fatigue Testing Fatigue tests on both the GFRP-neat and GFRP-modified composites were conducted under a standard helicopter rotor spectrum load sequence, HELIX-32 shown in Spectrum fatigue tests were performed on GFRP composites with different reference stress levels ranging from 125 MPa to 200 MPa. The spectrum load sequence block with specific reference stress was repeatedly applied to the test specimens until failure and the fatigue life, expressed as the number of blocks to failure, was determined. The test specimens of size 150 mm x 12 mm x 2.6 mm with end-tabs were employed for the spectrum fatigue tests. All the tests were conducted using a computer controlled 25 kN servo-hydraulic test machine. When the specimen failed in-between any block, the fraction of the block completed was determined as the ratio of the number of reversals applied until then to the total number of reversals in the block. 5 The stiffness variation of the specimen subjected to spectrum fatigue loads was determined during the test as a function of the number of applied load blocks. Whenever stiffness measurement data were required, the fatigue test was intermittently stopped, a load cycle with σ max = 0.5 σ ref and stress ratio R=σ min / σ max = 0 was applied, the load, displacement data was obtained and analyzed. Considering the large number of load cycles in one block, insertion of this one cycle was assumed not to alter the fatigue damage in the material significantly. For the purpose of comparison, the normalized stiffness of the specimen was defined as the ratio of measured stiffness at any given time to the initial stiffness (obtained before application of the first spectrum load block). For one particular test with σ ref =160 MPa, the specimens were dismounted at the end of the application of one complete load block and photographs showing matrix cracks were obtained, as explained in Manjunatha et al. RESULTS AND DISCUSSION The spectrum fatigue life determined for both the GFRP-neat and GFRP-modified composites under the HELIX-32 load sequence at various reference stresses is shown in The fatigue failure mechanisms under cyclic loads in polymer composites involve The stiffness loss in 'stage I' and 'stage II' results primarily from matrix cracking 'stage III' [25] which lead to an improvement in the spectrum fatigue life of the GFRP-modified composite. It is to be noted that the fatigue life enhancement is about eight to ten times under constant amplitude loads at stress ratio, R =0.1 CONCLUSIONS Based on the results obtained in this investigation the following conclusions may be drawn: 1. The addition of 9 wt.% rubber micro-particles and 10 wt.% of silica nanoparticles to the epoxy matrix of a GFRP composite (i.e. to give the GFRPmodified material) enhances the fatigue life under the HELIX-32 spectrum load sequence by about three times. 8 2. The stiffness degradation of the GFRP-neat composite is more severe than that of the GFRP-modified composite during the fatigue loading. The suppressed matrix cracking and reduced crack and delamination growth rate in the modified epoxy matrix of the GFRP-modified composite enhances the fatigue life under spectrum load sequence. ACKNOWLEDGEMENT
Cluster radioactivity in superheavy nuclei 299-302120
The cluster radioactivity is an unusual decay process observed in superheavy nuclei. When a cluster nuclei are emitted, the residual or daughter nuclei is having doubly magic nuclei or it may be neighbourhood of the same. We have studied cluster radioactivity [4He, 6Li, 9Be, 20,22Ne, 23N, 24-26Mg, 28-30Si, 31P, 32-34S, 35Cl, 36,38,40Ar, 40-46Ca ] in the superheavy nuclei 299-302120 using the nuclear and proximity model. The calculated cluster decay half-lives are compared with that of the other theoretical models such as Univ1, NRDX2, UDL3 and Horoi4. From the comparison of different models we have observed that the cluster nuclei with 4He, 9Be, 22Ne, 26Mg, 30Si, 34S, 40Ca and 46Ca are having smaller logarithmic half-lives than the exotic cluster decay modes
Systematics of proton decay of actinides
The phenomenon of proton emission from nuclear ground states limits the possibilities of the creation of more exotic proton rich nuclei that are usually produced by fusion-evaporation nuclear reactions. In the energy domain of radioactivity, proton can be considered as a point charge having highest probability of being present in the parent nucleus. Conclaves et al.1 studied the two-proton radioactivity of nuclei of mass number A<70 using the effective liquid drop model. Delion et al.2 reviewed the theories of proton emission to analyse the properties of nuclear matter. Maglione et al.3 analysed the proton emission from the some deformed nuclei. We have studied proton decay in almost all actinide nuclei. We have calculated the energy released during the proton decay (QP), penetration factor (P), and half-lives of proton decay. Proton decay half-lives are also longer than that of other decay modes such as alpha decay and spontaneous fission. To check the Geiger-Nuttal law for proton decay in actinide nuclei, we have plotted the logarithmic proton decay half-lives versus 1/sqrt(Q). The competition of proton decay with different decay modes such as alpha decay and spontaneous fission are also studied. We have also highlighted possible proton emitters with the corresponding energies and half-lives in the actinide region
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)
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