27 research outputs found
On Gaver's parallel system
Gaverâs parallel system (and its variants) has received considerable attention in the literature.
The Laplace-transform (LT) of the survival function, corresponding to the underlying
systems, has been derived by various (alternative) methods. Unfortunately, little-to-no
attention has been paid to invert the corresponding transform. First, we present a general
reliability analysis of Gaverâs basic parallel system (valid for an arbitrary repair time
distribution). Then, we formulate some general hints to obtain the numerical inverse. Finally, we propose a tangible methodology to derive the exact inverse in some particular but important cases of non-rotational transforms.Gaver se parallelsisteem (en variante daarvan) is reeds dikwels behandel in die literatuur. Die Laplacetransformasie van die oorlewingsfunksie van die onderliggende sisteme is reeds afgelei op verskillende uiteenlopende wyses. Ongelukkigerwys is min aandag gegee aan die ooreenstemmende inverse transformasie. Ten aanvang word 'n algemene
betroubaarheidsontleding van Gaver se basiese parallelsisteem voorgehou (geldig vir 'n
arbitrĂȘre hersteltyd-verdeling). Dit word gevolg deur wenke vir bepaling van die numeriese
inverse. Ten slotte word 'n tasbare metodologie vir die afleiding van die presiese inverse vir sekere belangrike nie-rotasionele transformasies voorgestel.http://sajie.journals.ac.z
Magnetoelectric coupling in strained strontium titanate and Metglas based magnetoelectric trilayer
Direct magneto electric coupling is observed with a magnetoelectric coupling coefficient (MECC) of 806âŻmVâŻcmâ1âŻOeâ1 at 750âŻHz in strontium titanate (STO) - Metglas - strontium titanate (STO-Metglas-STO) trilayer thin films with a total thickness of 600âŻnm. The piezoelectricity in the strained STO layer, which is otherwise a paraelectric material, enabled the sandwiched magneto electric structure to exhibit a fair sub resonant magneto electric coupling. Theoretical models proposed by Bichurin et al. and Hasanyan et al. are employed to calculate the values of MECC at sub resonant condition for the system, which is noted as 853âŻmVâŻcmâ1âŻOeâ1. The frequency dependence of MECC coefficient is also calculated and the resonance frequency is estimated as 706âŻHz.publishe
High frequency impedance based fault location in distribution system with DGs
Distributed generations (DGs) in the distribution systems are connected into the buses using power electronic converters. During fault, it is challenging to provide a constant impedance model for DGs in the system frequency due to the variable converter control strategies. System frequency impedance measurement based fault locations can be influenced by the convertersâ fault behaviour. This study addresses this problem by proposing a wide-area high-frequency impedance comparison based fault location technique. The high-frequency impedance model of DG is provided. Based on the constant DG impedance model in high-frequency range, the faulted line sections can be distinguished by comparing the measured impedance differences without requiring the exact distribution system parameters. Simulation results show that the proposed wide-area transient measurements based fault location method can provide accurate faulted sections in the distribution systems with DGs regardless of the load and DG output variations, measurement noise, unbalanced loads and islanding operations
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Membrane TensionâMediated Growth of Liposomes
Recent years have seen a tremendous interest in the bottom-up reconstitution of minimal biomolecular systems, with the ultimate aim of creating an autonomous synthetic cell. One of the universal features of living systems is cell growth, where the cell membrane expands through the incorporation of newly synthesized lipid molecules. Here, the gradual tension-mediated growth of cell-sized (â10 ”m) giant unilamellar vesicles (GUVs) is demonstrated, to which nanometer-sized (â30 nm) small unilamellar vesicles (SUVs) are provided, that act as a lipid source. By putting tension on the GUV membranes through a transmembrane osmotic pressure, SUVâGUV fusion events are promoted and substantial growth of the GUV is caused, even up to doubling its volume. Thus, experimental evidence is provided that membrane tension alone is sufficient to bring about membrane fusion and growth is demonstrated for both pure phospholipid liposomes and for hybrid vesicles with a mixture of phospholipids and fatty acids. The results show that growth of liposomes can be realized in a protein-free minimal system, which may find useful applications in achieving autonomous synthetic cells that are capable of undergoing a continuous growthâdivision cycle.Accepted Author ManuscriptBN/Cees Dekker La
Not Available
Not AvailableBACKGROUND
Effects of supplementation of dried alkaline (referred to as MVP1) and aqueous (referred to as PBD1) extracts of K. alvarezii , were evaluated in broiler (Vencobb 400) chickens (1â35 d postâhatch). In experiment I, each of the seven diets (basal diet with three levels (0.5, 1.5 or 5.0 g kgâ1 diet) of MVP1 or PBD1 and a negative control) was fed to twelve pen replicates containing five birds in each. In experiment II, each of three diets (a negative control, and PBD1 at two levels (1.0 or 1.5 g kgâ1 diet)) was fed to sixteen pen replicates of five chicks in each.
RESULTS
Concentrations of total phenolics, phycobillins and free radical scavenging activity were higher (P<0.01) whereas carrageenan was lower in PBD1 than in MVP1. In the experiment I, PBD1 at 1.5 g kgâ1 diet improved (P<0.05) body weight (7.11% higher). In the experiment II, both the treatments improved (P<0.01) BW (9.18% and 8.47%, respectively) as compared to control. The group fed with PBD1@ 1.0 g kgâ1 had higher (P<0.05) HI titre, expression of intestinal claudin 2, TLR2A, NOD1, avian beta defensin 4, interleukin 2 and 6 genes than control. Treatments did not influence feed efficiency or levels of most of the antioxidant enzymes. Villus width and crypt depth were significantly higher in the group fed with 1.5 g kgâ1 of PBD1.
CONCLUSION
Supplementing dried aqueous extract of Kappaphycus alvarezii at 1 g kgâ1 diet may be an effective strategy to increase growth and immunity in broiler chicken.Sea6 Energy Pvt Ltd, Bangalore, Indi