scholarly journals Light from a firefly at temperatures considerably higher and lower than normal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mana Mohan Rabha ◽  
Upamanyu Sharma ◽  
Anurup Gohain Barua
Keyword(s):  
Steady State ◽  
Temperature Tolerance ◽  
Indian Species ◽  
Large Fluctuation ◽  
Peak Wavelength ◽  
Flash Duration ◽  
Hot Days ◽  
Different Temperatures ◽  
Species Being ◽  
Selection Of

AbstractBioluminescence emissions from a few species of fireflies have been studied at different temperatures. Variations in the flash-duration have been observed and interesting conclusions drawn in those studies. Here we investigate steady-state and pulsed emissions from male specimens of the Indian species Sclerotia substriata at temperatures considerably higher and lower than the ones at which they normally flash. When the temperature is raised to 34 °C, the peak wavelength gets red-shifted and the emitted pulses become the narrowest which broaden considerably thereafter for small increases in temperature; this probably indicates denaturation of the enzyme luciferase catalyzing the light-producing reaction. When the temperature is decreased to the region of 10.5–9 °C, the peak gets blue-shifted and the flash-duration increased abnormally with large fluctuation; this possibly implies cold denaturation of the luciferase. We conclude that the first or hot effect is very likely to be the reason of the species being dark-active on hot days, and the second or cold one is the probable reason for its disappearance at the onset of the winter. Our study makes the inference that these two happenings determine the temperature-tolerance, which plays a major role in the selection of the habitat for the firefly.

Selection of one-dimensional sedimentation: models for on-line use

1995 ◽  
Vol 31 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Koen Grijspeerdt ◽  
Peter Vanrolleghem ◽  
Willy Verstraete
Keyword(s):  
Steady State ◽  
Selection Criteria ◽  
Data Sets ◽  
Concentration Profiles ◽  
A Posteriori ◽  
One Dimensional ◽  
On Line ◽  
Dynamic Concentration ◽  
Selection Of ◽  
Modelling Task

A comparative study of several recently proposed one-dimensional sedimentation models has been made. This has been achieved by fitting these models to steady-state and dynamic concentration profiles obtained in a down-scaled secondary decanter. The models were evaluated with several a posteriori model selection criteria. Since the purpose of the modelling task is to do on-line simulations, the calculation time was used as one of the selection criteria. Finally, the practical identifiability of the models for the available data sets was also investigated. It could be concluded that the model of Takács et al. (1991) gave the most reliable results.

scholarly journals Selection of cowpea cultivars for high temperature tolerance: physiological, biochemical and yield aspects

2021 ◽  
Author(s):  
Juliane Rafaele Alves Barros ◽  
Miguel Julio Machado Guimarães ◽  
Rodrigo Moura e Silva ◽  
Maydara Thaylla Cavalcanti Rêgo ◽  
Natoniel Franklin de Melo ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Tolerance ◽  
Cowpea Cultivars ◽  
High Temperature Tolerance ◽  
Selection Of

Numerical Simulation on Rupture Behavior and Selection of Safety Membranes

2014 ◽  
Author(s):  
Chen Sheng ◽  
Zhang Jian ◽  
Xiaodong Yu
Keyword(s):  
Present Theory ◽  
Large Fluctuation ◽  
Surge Tank ◽  
Small Hydropower ◽  
Weak Points ◽  
Maximum Water ◽  
Safety Operation ◽  
Hydropower Stations ◽  
Selection Of ◽  
Rupture Behavior

This present study deals with a new mechanical device consisting of a set of safety membranes, which has been successfully applied in several middle and small hydropower stations in China instead of a surge tank. Safety membranes are installed on the penstock near the powerhouse as controlled weak points. When the pressure caused by load rejection rises to the preset explosive value, one or more membranes rupture, protecting the penstock and the unit from damage. The device is simple, reliable and economical. The method of characteristics is employed to establish numerical model of safety membranes to simulate their rupture behavior, which is then introduced to investigate how to determine the number and diameter of membranes from two aspects, large fluctuation and hydraulic disturbance. The results show that the diameter of the membranes depends on the negative pressure along pipeline under hydraulic disturbance while the number of the membrane depends on the maximum water hammer pressure under large fluctuation during load rejection of the unit. The conclusion of membrane selection can perfect the present theory of safety membranes, and provide the theoretical guidance and practical basis for membrane device design and safety operation.

Optimum Selection of Hydraulic Devices for Water Hammer Control in the Pipeline Systems Using Genetic Algorithm

2003 ◽  
Author(s):  
Bong Seong Jung ◽  
Bryan W. Karney
Keyword(s):  
Genetic Algorithm ◽  
Steady State ◽  
Optimization Problems ◽  
System Optimization ◽  
Water Hammer ◽  
Pipeline System ◽  
Optimal Size ◽  
Protection Strategy ◽  
Hydraulic Devices ◽  
Selection Of

Genetic algorithms have been used to solve many water distribution system optimization problems, but have generally been limited to steady state or quasi-steady state optimization. However, transient events within pipe system are inevitable and the effect of water hammer should not be overlooked. The purpose of this paper is to optimize the selection, sizing and placement of hydraulic devices in a pipeline system considering its transient response. A global optimal solution using genetic algorithm suggests optimal size, location and number of hydraulic devices to cope with water hammer. This study shows that the integration of a genetic algorithm code with a transient simulator can improve both the design and the response of a pipe network. This study also shows that the selection of optimum protection strategy is an integrated problem, involving consideration of loading condition, device and system characteristics, and protection strategy. Simpler transient control systems are often found to outperform more complex ones.

Comparison of Controllers for a UAV with Integral Effect and Kalman Estimator: By Bessel Polynomials and LQR

2013 ◽  
Vol 436 ◽  
pp. 54-60 ◽  
Author(s):  
Wenceslao Eduardo Rodríguez ◽  
Ramiro Ibarra ◽  
Gerardo Romero ◽  
David Lara ◽  
Jaime Arredondo ◽  
...  
Keyword(s):  
Steady State ◽  
Pole Placement ◽  
Control Technique ◽  
State Estimator ◽  
Control Laws ◽  
State Response ◽  
Integral Effect ◽  
Aerial Vehicle ◽  
Pole Placement Controller ◽  
Selection Of

This paper presents the development of two different control techniques as an approach having to remove steady-state error present in the response of attitude of a mini unmanned aerial vehicle. A problem that arises when performing pole placement controller is the selection of the poles, the Bessel approximation allows the selection of the eigenvalues in function to a specified response time for a feedback pole placement controller and state estimator (observer). On the other hand presents an optimal control technique combined with Kalman filter to estimate the state affected by perturbations in the system, both cases using the integral effect to eliminate the steady state error.These two control laws has the property of responding to a desired response according to a time or state response desired.

BEYOND THE STEADY STATE: MANAGING DISCONTINUOUS PRODUCT AND PROCESS INNOVATION

2006 ◽  
Vol 10 (02) ◽  
pp. 175-196 ◽  
Author(s):  
WENDY PHILLIPS ◽  
HANNAH NOKE ◽  
JOHN BESSANT ◽  
RICHARD LAMMING
Keyword(s):  
Steady State ◽  
Relative Stability ◽  
Good Practice ◽  
Innovation Process ◽  
Effective Management ◽  
Product And Process Innovation ◽  
Good Guide ◽  
Product And Process ◽  
Discontinuous Innovation ◽  
Selection Of

Research on the innovation process and its effective management has consistently highlighted a set of themes constituting "good practice". The limitation of such "good practice" is that it relates to what might be termed "steady state" innovation — essentially innovative activity in product and process terms which is about "doing what we do, but better". The prescription works well under these conditions of (relative) stability in terms of products and markets but is not a good guide when elements of discontinuity come into the equation. Discontinuity arises from shifts along technological, market, political and other frontiers and requires new or at least significantly adapted approaches to their effective management. This paper highlights empirical findings from a selection of companies involved in a project sponsored by the U.K. Department of Trade and Industry. The results indicate a number of key routines that organisations could implement to enable discontinuous innovation.

scholarly journals Selection of Cosmological Models Using QSOs

1972 ◽  
Vol 44 ◽  
pp. 471-473
Author(s):  
R. C. Roeder
Keyword(s):  
General Relativity ◽  
Steady State ◽  
Emission Line ◽  
Cosmological Models ◽  
Present Evidence ◽  
Normal Galaxy ◽  
Steady State Model ◽  
Lower Limits ◽  
Best Fit ◽  
Selection Of

It is assumed that the QSOs are at cosmological distances as indicated by their emission-line redshifts. It is further assumed, as indicated by present evidence, that none of the 21 QSOs with emission-line redshifts, ze, of 2.0 ± 0.1 (or of the 30 with ze = 2.0 ± 0.2) is screened by an intervening normal galaxy. The simplest conclusion from these data is, then, that the screening probability must be less than 0.08 (or 0.06) at ze = 2.0. This, in turn, restricts allowable cosmological models in the (σ0, q0) diagram by providing lower limits for ß0 as a function of q0. One can also rank cosmological models in order of the probability that there be no screening of the 21 (or 30) objects. In either case the steady state model ranks higher than the general relativity models found by Peach to give the best fit in the (m – z) diagram.

scholarly journals The temperature of growth and sporulation modulates the efficiency of spore-display in Bacillus subtilis

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Claudia Petrillo ◽  
Stefany Castaldi ◽  
Mariamichela Lanzilli ◽  
Anella Saggese ◽  
Giuliana Donadio ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Spore Production ◽  
Bacterial Spores ◽  
Heterologous Proteins ◽  
Dna Coding ◽  
Gene Coding ◽  
Different Temperatures ◽  
Mucosal Vaccines ◽  
Heterologous Antigens ◽  
Selection Of

Abstract Background Bacterial spores displaying heterologous antigens or enzymes have long been proposed as mucosal vaccines, functionalized probiotics or biocatalysts. Two main strategies have been developed to display heterologous molecules on the surface of Bacillus subtilis spores: (i) a recombinant approach, based on the construction of a gene fusion between a gene coding for a coat protein (carrier) and DNA coding for the protein to be displayed, and (ii) a non-recombinant approach, based on the spontaneous and stable adsorption of heterologous molecules on the spore surface. Both systems have advantages and drawbacks and the selection of one or the other depends on the protein to be displayed and on the final use of the activated spore. It has been recently shown that B. subtilis builds structurally and functionally different spores when grown at different temperatures; based on this finding B. subtilis spores prepared at 25, 37 or 42 °C were compared for their efficiency in displaying various model proteins by either the recombinant or the non-recombinant approach. Results Immune- and fluorescence-based assays were used to analyze the display of several model proteins on spores prepared at 25, 37 or 42 °C. Recombinant spores displayed different amounts of the same fusion protein in response to the temperature of spore production. In spores simultaneously displaying two fusion proteins, each of them was differentially displayed at the various temperatures. The display by the non-recombinant approach was only modestly affected by the temperature of spore production, with spores prepared at 37 or 42 °C slightly more efficient than 25 °C spores in adsorbing at least some of the model proteins tested. Conclusion Our results indicate that the temperature of spore production allows control of the display of heterologous proteins on spores and, therefore, that the spore-display strategy can be optimized for the specific final use of the activated spores by selecting the display approach, the carrier protein and the temperature of spore production.

scholarly journals Fluorescence investigation of epoxy resin LG 285 and mathematical description of the curing process

2019 ◽  
Vol 292 ◽  
pp. 01025
Author(s):  
Michaela Mikuličová ◽  
Vladimír Vašek ◽  
Vojtěch Křesálek
Keyword(s):  
Steady State ◽  
Fluorescence Spectroscopy ◽  
Epoxy Resin ◽  
Mathematical Description ◽  
Curing Process ◽  
Steady State Fluorescence ◽  
Two Component ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Steady State Fluorescence Spectroscopy

In this paper, steady-state fluorescence spectroscopy is used to investigate the curing of two-component epoxy resin LG 285. Moreover, the process of curing is mathematically described. The mixture of resin and hardener HG 287 is measured at five different temperatures (50 °C, 60 °C, 70 °C, 80 °C and 90 °C) for five and a half hours. The results indicate that the process of curing of epoxy resin decelerates with time and accelerates with increasing temperature. Furthermore, the energy of the barrier is calculated.

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