323 research outputs found
In vitro strategies for improvement of frost tolerance in cauliflower.
Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance
Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix
A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue
of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm
diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly
affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand
explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained
from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture,
only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline
levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in
the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant
shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors .
These will then be evaluated for any alteration in frost tolerance
Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix
A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue
of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm
diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly
affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand
explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained
from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture,
only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline
levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in
the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant
shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors .
These will then be evaluated for any alteration in frost tolerance
In vitro strategies for improvement of frost tolerance in cauliflower.
Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance
Engineering ambient visual sensors
Visual sensors are an indispensable prerequisite for those AmI environments that require a surveillance component. One practical issue concerns maximizing the operational longevity of such sensors as the operational lifetime of an AmI environment itself is dependent on that of its constituent components. In this paper, the intelligent agent paradigm is considered as a basis for managing a camera collective such that the conflicting demands of power usage optimization and system performance are reconciled
On SETAR non- linearity and forecasting
We consider the usefulness of the two-regime SETAR model for out-of-sample forecasting, and compare it with a linear AR model. A range of newly-developed forecast evaluation techniques are employed. Our simulation results show that time-series data need to exhibit a substantial degree of non-linearity before the SETAR model is favoured on some of these criteria. We find only weak evidence that a SETAR model of US GNP provides more accurate forecasts than a linear AR model
Compact latent heat storage decarbonization potential for domestic hot water and space heating applications in the UK
A performance comparison is presented for a domestic space and hot water heating system with a conventional gas boiler and an air source heat pump (ASHP) with latent heat storage, both with solar thermal collectors for a typical UK climate, to demonstrate the potential of phase change material based energy storage in active heating applications. The latent heat thermal storage system consisted of 10 modules with RT54HC comprising a total storage capacity of 14.75kWh that provided 53% extra thermal storage capacity over the temperature range of 40 to 65°C compared to a water only store. The simulations predicted a potential yearly CO2 reduction of 56%, and a yearly energy reduction of 76% when operating the heat pumps using the economy 10 electricity tariff i.e a low tariff between 00.00-05.00 and 13.00-16.00 with current grid emission values compared to the conventional gas boiler system; successfully offsetting the electrical load to meet the required heat demand. Due to the high capital costs of the heat pump system with latent heat storage, its levelized cost of energy was 117.84£/MWh, compared to 69.66£/MWh for the gas boiler, on a 20-year life cycle
Thermal energy storage for low and medium temperature applications using phase change materials – a review
A comprehensive review of phase change materials (PCMs) with phase transition temperatures between 0 and 250 °C is presented. From that review, organic compounds and salt hydrates seem more promising below 100 °C and eutectic mixtures from 100 to 250 °C.
Practical indirect heat exchanger designs for latent heat storage systems were also assessed and feasible heat enhancement mechanisms reviewed. The focus on this temperature range is due to potential CO2 emissions reduction able to be achieved replacing conventional heating and cooling applications in the domestic, commercial and public administration sectors, which represented around a quarter of the UK’s final energy consumption in 2015
Field trial of an acoustic emission early warning system for slope instability
Slope failures world-wide cause many thousands of deaths each year and damage built environment infrastructure costing billions of pounds to repair, resulting in thousands of people being made homeless and the breakdown of basic services such as water supply and transport. There is a clear need for low cost instrumentation that can provide an early warning of slope instability to enable evacuation of vulnerable people and timely repair and maintenance of critical infrastructure. Current instrumentation systems are either too expensive for wide scale use or have technical limitations. An approach, Assessment of Landslides using Acoustic Real-time Monitoring Systems (ALARMS), has been developed and demonstrated through research. An approach developed using measurement of acoustic emission generated during the onset of slope failure to provide quantitative information on slope displacement is described. Sensor operation, deployment strategy, laboratory validation and field performance is considered. The paper presents the results of a field trial of acoustic sensors on an active landslide at Hollin Hill, North Yorkshire, and introduces additional ongoing tri-als in the UK and Italy. Real-time monitoring of acoustic emission generated by the deforming slope has been compared to traditional inclinometer slope displacement measurements. Analysis of the results of the field trial has established that there is a direct relationship between AE and displacement rate trends triggered by rainfall events. Slope deformation events have a characteristic ‘S’ shaped cumulative AE vs. time relationship indicating initial acceleration followed by deceleration of the slide body
Intelligent middleware for adaptive sensing of tennis coaching sessions
In professional tennis training matches, the coach
needs to be able to view play from the most appropriate angle in order to monitor players activities. In this paper, we present a system which can adapt the operation of a series of cameras in order to maintain optimal system performance based on a set of wireless sensors. This setup is used as a testbed for an agent based intelligent middleware that can correlate data from many different wired and wireless sensors and provide effective in-situ decision making. The proposed solution is flexible enough
to allow the addition of new sensors and actuators. Within this setup we also provide details of a case study for the embedded control of cameras through the use of Ubisense data
- …