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A simple method is introduced for computing the effective conductivity of isotropic composite with imperfect interface. Based on the doubly-coated circle assemblage model, one can determine the effective thermal conductivity of the composite. The application of this model to the composite with imperfect interface of the Kapitza's type is proposed. The results obtained were compared with the Fast Fourier Transform simulation and the equivalent inclusion approximation in 2D show the effectiveness of the methods.

Article introduces the Fast-Fourier transformation method (FFT) and an approximation method to calculate the conductivity of compound-inclusion composites in two-dimensional space. The approximation compares favorably with the numerical results for a number of periodic and random models over a range of volume proportions of phases, but divers at large volume proportions of the included phases when the interactions between the inclusions are more pronounced.

Three-point correlation bounds are constructed on effective conductivity of unidirectional composites, which are isotropic in the transverse plane. The bounds contain, in addition to the properties and volume proportions of the component materials, three-point correlation parameters describing the micro-geometry of a composite, and are tighter those obtained in [1]. The bounds, applied to some disordered and periodic composites, keep inside the numerical homogenization results obtained by Fast Fourier method.

A long-term experiment to study the effects of nitrogen (N), phosphorus (P) and potassium (K) in intensive rice monoculture commenced at the Cuu Long Delta Rice Research Institute (CLRRI), Omon, Vietnam, in 1986. Two lowland rice crops, transplanted and irrigated, of cultivar IR64 were grown each year, one in the wet season (WS) from May to August, and the other in the dry season (DS) from December to March. The soil is an Fluvaquentic Humaquept representative of much of the double-cropped rice area in the Mekong Delta. The eight treatments were N-P-K fertiliser at the following rates in kg element ha −1 : 0-0-0 (check), 80-0-0, 0-17.5-0, 0-0-25, 80-17.5-0, 80-0-25, 0-17.5-25, and 80-17.5-25 in a randomised complete block with 4 replications. Mean grain yields 1986–1994 ranged from 2.1 t ha −1 for nil fertiliser in the WS to 5.9 t ha −1 with N + P in the DS. Wet season yields showed significant decline with time. The most rapid decline was 376 kg ha −1 year −1 from an initial level of 3.9 t ha −1 for the treatment of N without P. Dry season yields of the N + P treatments increased at a rate of 293 kg ha −1 year −1 to over 5 t ha −1 . Nitrogen fertiliser-use efficiency declined rapidly in WS, even in combination with P. There was no significant benefit from K throughout. The main yield component reduced in WS was the number of grain per panicle. Phosphorus in combination with N returned up to 180 kg grain per kg P for WS and around 80 kg ha −1 in DS. Summed over all 16 crops, the application of N + P returned an additional 26 t grain ha −1 over the check or treatments with N alone. This was after deduction of the cost of fertiliser as grain equivalent. Phosphorus is a key factor for productivity in this environment, and if adequately supplied can prevent WS yield decline.

This article 'Two Promising IRRI Rice Hybrids Named in Vietnam' appeared in the International Rice Research Notes series, created by the International Rice Research Institute (IRRI) to expedite communication among scientists concerned with the development of improved technology for rice and rice-based systems. The series is a mechanism to help scientists keep each other informed of current rice research findings. The concise scientific notes are meant to encourage rice scientists to communicate with one another to obtain details on the research reported., IRRI publication.

This article 'Om91: an Improved Rice Variety for High-Production Irrigated Areas' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Mashuri for Cultivation in the Cuu Long Delta of Vietnam' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Performance of IR42 and IR48 in Cuu Long Delta, Vietnam' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Evaluation and Use of Male Sterile Systems in Mekong Delta, Vietnam' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Evaluation of F1 Hybrids on the Cuu Long Delta, Vietnam' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Effect of N Sources and Levels on Deep Water Rice' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Two IRRI Rice Lines Released for Cultivation in the Cuu Long Delta' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'Performance of Some Promising Varieties in Floating-Rice Areas of Cuu Long Delta' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.

This article 'IR18348-36-3-3, a Promising Rice for Irrigated and Slight Acid Sulfate Soil in Vietnam' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.