The Newcastle Connection

The Newcastle Connection is a transparent layer of software designed to make several Unix systems appear as one. Based on Ethernet, it opens up applications not normally associated with Unix-system networks. This paper describes the structure of the Newcastle Connection. System calls, name-neighbour space, address space, facilities for ‘super-users’, remote system access and large-scale administration are covered.     

Acoustic intensity for a long vessel with noncircular cross section

The acoustic intensity distribution around and within long vessels of noncircular cross section was investigated for parameters typical of biomedical ultrasound and blood vessels. We have developed a collocation method for finding the acoustic field when a uniform plane wave is obliquely incident on a long, not necessarily cylindrical, impedance interface. Results are presented for vessels of noncircular cross section and for vessels with thick walls of nonuniform thickness. The intensity in the vicinity of the vessel, throughout the lumen, and in the wall, is calculated for intermediate length scales, i.e., vessel radius and wall thickness in the range 1 to 10 wavelengths. The intensity distribution is an interference pattern, with complicated regions of increased and decreased intensity. These results are compared with approximate intensity obtained using ray theory. Effects not predicted by ray theory and intensity variations that will be significant in any close ultrasonic investigation of these vessels are revealed.     

Intelligent algorithmic interpretation of pollutant discharges from multi-unit industrial complexes

Groups of factories in which many units share a single site are common within the chemical industry. This clustering of a number of synthetic units leads to economies of scale through the sharing of resources, and minimization of direct costs such as those arising from the storage and transportation of chemicals. Among the resources usually shared is the system whose role is to dispose of liquid chemical waste. To control effectively the discharge of such waste from the plants on-site, a knowledge of the composition and quantity of waste produced by each factory is essential information, but extracting this from the available data is not a simple matter. In this paper we define a fuzzy relation to track backward from imprecise monitoring station data, and discuss the use of a genetic algorithm to assess the data, in order to calculate the individual outputs of each factory. This hybrid genetic-fuzzy approach can be used to effectively interpret waste flow data from multi-unit complexes up to industrial scale. © 1997 John Wiley & Sons, Inc.     

Craze morphology and molecular orientation in the slow crack growth failure of polyethylene

An optical microscopy study and a micro‐Raman spectroscopy study were carried out on polyethylene samples subjected to an environmental stress crack resistance (ESCR) test. The aim was to elucidate the molecular deformation mechanisms associated with the failure process. It has been shown that in the early stages of the ESCR test, in a regime of low local stress, failure in the craze occurs via a brittle process with limited ductility and with molecular orientation being detected. As the experiment progresses, however, extensive fibrillation takes place. The molecular orientation in these fibrils was found to be comparable to that measured in cold‐drawn samples. Moreover, the fibril molecular orientation decreased from the crack to craze tip and was found to be higher in the midrib part of the fibril (fibril failure point). As a consequence, fibril creep is the most likely mechanism of failure in the craze. Microscopy and Raman measurements showed that the extent of the brittle process is molecular weight‐dependent, that is, the brittle process seems to operate longer at higher molecular weights. These observations are in agreement with a previous work which showed that the molecular stress per macroscopic strain/stress decreases with increasing molecular weight, therefore holding the high molecular weight craze in a regime of low local stress for longer testing times. Fibrils spanning the craze are envisaged as the anchor points that hold the structure during the process of failure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 283–296, 2000     

Measurement of real-time gain gratings in erbium-doped fiber

Experimental and theoretical results for nonlinear wave mixing in a pumped erbium-doped fiber are presented where a fast phase transient is applied to one of the beams. The ratio of the imaginary part to the real part of the complex nonlinear refractive index is determined from the initial phase of the beam coupling. The fast phase transient is applied for the first time to measure the response time of index gratings in a nonlinear device. We show that the grating lifetime depends on both the pump and amplified signal beams and that the nonlinear index change occurs with a time constant of the order of 100 μs for CW conditions in a highly doped fiber     

用MPS变形机生产花式长丝

描述了德国巴马格公司的MPS变形机的特性和应用.MPS变形机的理念使长丝生产商对于市场的需求能作出迅速有效的响应.已生产的长丝大致可分为三类:与通常变形丝手感不同的长丝、与标准变形丝染色特性不同的长丝及在某种程度上同时显示以上两种特性的长丝.     

Form and functionality of starch

Starch is a macro-constituent of many foods and its properties and interactions with other constituents, particularly water and lipids, are of interest to the food industry and for human nutrition. Starch varies greatly in form and functionality between and within botanical species, which provides starches of diverse properties but can also cause problems in processing due to inconsistency of raw materials. Being able to predict functionality from knowledge of the structure, and explain how starch interacts with other major food constituents remain significant challenges in food science, nutrition, and for the starch industry generally. This paper describes our current understanding of starch structure that is relevant to its functionality in foods and nutrition. Amylose influences the packing of amylopectin into crystallites and the organization of the crystalline lamellae within granules, which is important for properties related to water uptake. Thermal properties and gel formation appear to be influenced by both amylose content and amylopectin architecture. While amylose content is likely to have an important bearing on the functional properties of starch, subtle structural variations in the molecular architecture of amylopectin introduces uncertainty into the prediction of functional properties from amylose content alone. Our ability to relate starch granule structure to suitability for a particular food manufacturing process or its nutritional qualities depends not only on knowledge of the genetic and environmental factors that control starch biosynthesis, and in turn granule morphology, but also on how the material is processed.     

Wafer level packaging of a tape flip-chip chip scale packages

The advent of chip scale packages (CSPs) within the semiconductor community has led to the development of wafer scale assembly (WSA) or wafer level packaging (WLP) manufacturing in order to raise assembly efficiencies and lower operating costs. Texas Instruments (TI) has developed a unique WLP process for forming flip-chip, ball grid array packages. The die inputs and outputs of the TI CSP are connected through solder bumps to a polyimide film interposer. Solder balls on the other side of the interposer complete the electrical connection to a customer’s printed circuit board. A wafer-sized array of interposers designed to match the pattern of dies on a wafer is aligned and reflowed to a bumped wafer. The TI WLP process is completed by singulating the CSPs from the wafer using standard wafer saw equipment.Attachment of the interposer to the die as well as applying the die and board level solder bumps are carried out in wafer form using a new bumping technology called Tacky Dots™. Tacky Dots uses an array of sticky dots formed in a photosensitive coating laminated to a polyimide film for transferring and attaching solder spheres to semiconductor substrates. A populated film containing one solder sphere per Tacky Dot is positioned over the wafer or interposer and lowered until the spheres contact the pads. A reflow process transfers the spheres from the film to the wafer or interposer and the film is removed once the spheres have frozen.This paper illustrates the process steps and custom equipment developed for forming the TI CSP. The strategic use of finite element modeling for optimizing the design of the package is outlined. The paper concludes by summarizing the current package level reliability results.     

Hydrodynamics of fluid flow approaching a moving boundary

An experimental and numerical study has been conducted to investigate the flow field in the vicinity of a moving solid boundary that passes through a free surface into a liquid phase. Through the use of particle image velocimetry (PIV) techniques, the variation in the liquid velocity field in the vicinity of the three-phase contact line has been quantified for solid boundary velocities ranging between 0.12 and 1.01 m s⁻¹. The experimental measurements provide good verification for a preliminary numerical model that predicts the bulk-bath flow patterns and boundary layer thickness. This article is based on a presentation made in the “Geoffrey Belton Memorial Symposium,” held in January 2000, in Sydney, Australia, under the joint sponsorship of ISS and TMS.     

The effects of maltodextrins on gluten-free dough and quality of bread

The aim of the study was to check if maltodextrins of various dextrose equivalents (DE) could be used to improve stability and quality of gluten-free bakery products, and effectively reduce starch retrogradation. The maltodextrins, which were used for partial replacement of starch in the recipe for gluten-free dough, were characterised by DE 3.6, 15.3, 18.0 and 21.8. Basing on the obtained results it was concluded, that the addition of applied maltodextrins significantly influences starch gelatinisation, by increasing pasting temperature and reducing viscosity of the obtained pastes. Rheological properties of the obtained dough are also modified by maltodextrins, which weaken its structure and increase deformation sensitivity. The addition of maltodextrins with low DE (3.6) diminishes loaf volume and causes deterioration of bread quality. Maltodextrins with higher DE, especially 18.0 and 21.8, positively influence bread volume and have a beneficial influence on crumb hardening during storage. Maltodextrin with the highest DE is also an effective factor reducing recrystallisation enthalpy of amylopectin.