A Preliminary Investigation on Partial Rootzone Drying (PRD) Effects on Grapevine Performance, Nitrogen Assimilation and Berry Composition

Partial rootzone drying (PRD) is an irrigation management technique designed to reduce water use in grapevines without a decline in yield, thereby increasing water use efficiency (WUE). Experiments consisted of field-grown Cabernet Sauvignon, where the PRD grapevines were irrigated with half the amount of water as control grapevines, and Shiraz, where the PRD grapevines received the same amount of water as control grapevines.  PRD treatments showed no significant differences in yield or berry composition at harvest, except that PRD grapevines that received half the amount of water had significantly smaller berries than control grapevines. Cabernet Sauvignon PRD grapevines receiving half the amount of water as control grapevines showed a 34 % reduction in main shoot growth and up to a 74% reduction in lateral shoot growth. Shoot growth was inhibited to a lesser extent in Shiraz PRD grapevines receiving the same amount of water, with a 20% reduction in main shoot.growth and a 33% reduction in lateral shoot growth. PRD also significantly reduced stomatal conductance in Cabernet Sauvignon on average by 31 % and 16% in Shiraz. Nitrate reductase (NR) activity in grapevine leaves was significantly lowered in response to PRD, irrespective of the amount of water applied. The reduction in NR activity was closely correlated with the development of the PRD cycle and the associated reduction in stomatal conductance

Bluetongue in cattle : typing of viruses isolated from cattle exposed to natural infections

Bluetongue viruses were isolated from five clinically healthy bovines exposed to natural infection over two consecutive bluetongue seasons. The isolated viruses were typed by serum-virus neutralization and found to represent 11 of the established antigenic groups. Two isolations failed to be neutralized and may represent further antigenic types of bluetongue virus. No single virus type could be found to occur in the same bovine for two consecutive seasons and in most instances the particular virus type occurred in the blood ·of a bovine for a period of less than 14 days.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Relationship intention, customer-firm association length and customer satisfaction : a multi-country exploration

Customer-firm association length is used frequently as an indicator for identifying relational customers. This study explores rather using customers' relationship intentions by also considering the relationships between customer satisfaction with both association length and relationship intention. Data were collected under 1915 cell phone customers for the USA, South Africa, and the Philippines. Results confirm for all three samples: the measure is valid and reliable; three distinct relationship intention groups; similarity between corresponding relationship intention groups across the three countries; no relationship between customer-firm association length and customer satisfaction; and a direct relationship between satisfaction and relationship intention.The National Research Foundation of South Africahttp://www.inderscience.com/jhome.php?jcode=JGBA2021-12-29hj2021Marketing Managemen

Modeling the flow and heat transfer in a packed bed high temperature gas-cooled reactor in the context of a systems CFD approach

ABSTRACT Engineers are faced with two major challenges when carrying out the thermal-fluid design of a complex system consisting of many interacting components. The first challenge is to predict the performance of all the individual thermal-fluid components. The second challenge is to predict the performance of the integrated plant consisting of all its subsystems. The complexity associated with the thermal-fluid design of complex systems requires the use of a variety of analysis techniques and simulation tools. These range from simple one-dimensional models that do not capture all the significant physical phenomena, to large-scale three-dimensional computational fluid dynamics (CFD) codes that, for practical reasons, cannot simulate the entire plant as a single integrated model. In the systems CFD approach, a network code serves as the framework to link the models of the various components together and to control the solution. The models of the components can be of varying degrees of complexity. These can range from simple lumped models to complex fully three-dimensional CFD models. This paper gives a brief overview of the systems CFD (SCFD) approach and an overview of the model of the pebble bed nuclear reactor that was developed in the context of the SCFD approach.http://dx.doi.org/10.1115/1.400515

A review of methods to predict the effective thermal conductivity of packed pebble beds, with emphasis on the near-wall region

The effective thermal conductivity is an important parameter that is representative of the overall heat transfer in a packed bed of spheres. It includes the effects of conduction through the solid material and contact areas between spheres, conduction through the stagnant gas phase as well as thermal radiation between the surfaces of the spheres. An accurate prediction of the effective thermal conductivity is necessary for the design and analysis of packed pebble bed gas-cooled and solid fuel molten salt-cooled generation IV reactors, especially when considering the safety case. This includes the near-wall region where the packing structure is altered significantly. The well-known ZBS correlation is widely applied to predict the effective thermal conductivity and it is often implicitly assumed that it is equally applicable in the near-wall region. This paper presents an analysis of the validity of the ZBS correlation in this regard. In addition to this, an up-to-date review of methods used to predict the effective thermal conductivity is presented and methods that specifically account for the near-wall region are identified. It is noted that the contributions of the various heat transfer mechanisms are not yet fully understood and therefore the ability to separate the different mechanisms can be useful for understanding the characteristics in the near-wall regio