Protecting and Maintaining Silicon Valley’s Liquid Gold

Public sector leaders and decision makers in the California water industry have learned from previous severe drought conditions that to sustain water supplies during extremely dry seasons, there is a substantial need for behavioral changes associated with water conservation efforts among the businesses and residents of the community to maintain an adequate water supply. The intent of this study is to compare four California water agencies that have been designated as sustainable groundwater agencies (GSA), and determine what current programs and/or practices those agencies are using to meet the mandated requirements of the Sustainable Groundwater Management Act of 2014 (Act of 2014). Under the Act of 2014, GSAs have been given authority to enforce their GSA approved groundwater sustainability plan. This study goes on to examine some of the methods that are used by three other water districts, located outside of the state of California. This was done to determine best practices that have been implemented to address severe drought conditions, like the circumstances that Californians experienced from 2010 to 2016; a period when California experienced one of the worst droughts ever recorded in the state’s history (McCullough, 2015)

Pioneers, subcultures and cooperatives: The grassroots augmentation of urban places

About the book: There have been numerous possible scenarios depicted on the impact of the internet on urban spaces. Considering ubiquitous/pervasive computing, mobile, wireless connectivity and the acceptance of the Internet as a non extraordinary part of our everyday lives mean that physical urban space is augmented, and digital in itself. This poses new problems as well as opportunities to those who have to deal with it. This book explores the intersection and articulation of physical and digital environments and the ways they can extend and reshape a spirit of place. It considers this from three main perspectives: the implications for the public sphere and urban public or semi-public spaces; the implications for community regeneration and empowerment; and the dilemmas and challenges which the augmentation of space implies for urbanists. Grounded with international real -life case studies, this is an up-to-date, interdisciplinary and holistic overview of the relationships between cities, communities and high technologies

Two-Phase Region of the Vortex-Solid Melting Transition: 3D XY Theory

In clean enough samples of the high-$T_c$ oxide materials, the phase transition into the superconducting state occurs along a first order line in the $H$-$T$ plane. This means that a two-phase region occurs in the B-$T$ plane, in which the liquid and solid vortex phases coexist. We discuss the thermodynamics of this two-phase region, developing formulae relating experimental quantities of interest. We then apply the 3D XY scaling theory to the problem, obtaining detailed predictions for the boundaries of the coexistence region. By using published data, we are able to predict the width of the two-phase region, and determine the physical parameters involved in the 3D XY description.Comment: 5 pages LaTeX, 1 .eps figure, uses epsf.st

The Network Effects of Prefetching

Prefetching has been shown to be an effective technique for reducing user perceived latency in distributed systems. In this paper we show that even when prefetching adds no extra traffic to the network, it can have serious negative performance effects. Straightforward approaches to prefetching increase the burstiness of individual sources, leading to increased average queue sizes in network switches. However, we also show that applications can avoid the undesirable queueing effects of prefetching. In fact, we show that applications employing prefetching can significantly improve network performance, to a level much better than that obtained without any prefetching at all. This is because prefetching offers increased opportunities for traffic shaping that are not available in the absence of prefetching. Using a simple transport rate control mechanism, a prefetching application can modify its behavior from a distinctly ON/OFF entity to one whose data transfer rate changes less abruptly, while still delivering all data in advance of the user's actual requests

An Investigation into the Physics of Blowing Polysilicon Fuses

The semi-conductor fuses in this research are fabricated on a submicron process. A voltage potential is applied across the fuse, in order to achieve a blow. This current peaks with a short pulse in the order of tens of milliamps which has a long decrease to zero current flow, resulting in a blown fuse. A fuse blows due to the pinching together of electrically insulating material which initially surrounds the conducting pathway. The pinch cuts across the conductor, and so halts the current flow. In small-geometry fuses a cavity also forms during the blowing process. The company wishes to understand the fuse blow process mathematically in order to develop a model that can accurately simulate the blowing of the fuses. This report records the thermal, electrical, solid and fluid mechanics of the blowing process that was discussed at the Study Group, with remarks on possible future research for modelling the process