How Wikipedia Can Overcome the Great Firewall of China

Oil is the main insulation in power transformers and over long time of ageing its insulation properties can change. In this paper ageing of oil due to the exposure to electric discharges was investigated. The effect of high energy discharges (complete arc) and low energy discharges (partial discharges) on oil properties such as breakdown strength and oil conductivity was investigated. An experimental setup consisting of two spherical electrodes was designed. The adjustable distance between the two electrodes made it possible to have PD with different magnitude. The oil conductivity and breakdown strength was measured for three sets of experiments. The first group of experiments was performed on new oil in order to have a reference for comparison. In the second group of experiments the new oil samples was exposed to 1000 and 3000 lightning impulses. In the third group of experiments new oil samples was exposed to partial discharge for different duration of time. Oil conductivity and breakdown strength of these aged samples were compared with new oil. The results show that after exposure to lightning impulse oil conductivity increases and breakdown strength decreases, However PD activity for short time does not change the oil conductivity but it reduces the breakdown strength.QC 20140107</p

Sustainable energy performances of green buildings: a review of current theories, implementations and challenges

This study targets to elucidate the essence of sustainability in green building design implementations. In this regard, the study draws attention to the sustainable energy performances of green buildings to identify the influential parameters based upon the contemporary successful accomplishments. The study elaborates on the contemporary trends and applications of green building design and the respective impacts on sustainable developments. As a result, the analytical review confirms that the sustainable energy performance of green buildings has been transformed to a sensible and practical resolution to alleviate the CO2 emissions and diminish the building sector energy consumption. In addition, with view to the current challenges and barriers, the study concludes that; it is still crucial to identify and develop efficient energy solutions associated with green buildings for addressing the future energy demands. Likewise, the findings highlight that the sustainable energy performances associated with integrated technologies and renewable energy systems are still intertwined with significant challenges related to the fundamental parameters of cost, maintenance, and operation. In conclusion, the contemplations of the research findings are recommended to be taken into consideration by architects, engineers and developers for the development of future eco-cities with an explicit viewpoint towards developing greener and smarter built environments

Adaptation of Social Network Analysis for Facilitating Spatial Diagramming During Architectural Conceptual Design Phase

Designers have difficulty visualizing the end results of the projects during the initial architectural conceptual design phase. This research introduces a computational tool—Social Network Analysis (SNA)—commonly used in the communications field to study relationships between people for solving this visualization problem. The research intent was to affirm whether or not SNA can be utilized as a spatial planning tool during conceptual building design. The author posits that since the nodes and structural relationships between the nodes may have similar architectural characteristics, the tool would enable architects to make changes by moving any spaces on a floor plan while safely maintaining their spatial relationships to other spaces. In this research, the author developed a proof-of-concept model using an available SNA tool to facilitate spatial diagramming visualization during conceptual design phase. This study, tested the use of the SNA tool at four levels. The first level determined whether spatial relationship between functional spaces could be developed (such as the living room must be adjacent to the front entry). The second level was on setting priority values for the different nodes and the linkages. The third level determined whether this study could develop grouping relationships between several functional spaces that have a common characteristic (such as public versus private spaces) on one horizontal plan. The final fourth level determined whether the author could develop multiple layers (such as multi floors) that are connected by one common connector (such as a staircase in a double-story house). The corresponding models are validated intellectually by visual comparison between the simulated model of this study and another diagramming by (Nooshin, 2001) that was developed manually. The author is most interested in the fourth level because complexity in the spatial diagramming exercises is caused by multi-layered spatial arrangements at the horizontal and vertical planes. This study provided guidelines in developing a prototype for a spatial diagramming tool, which architects can use to resolve visualization problems when conducting the architectural spatial diagramming

BOK-Printed Electronics

The use of printed electronics technologies (PETs), 2D or 3D printing approaches either by conventional electronic fabrication or by rapid graphic printing of organic or nonorganic electronic devices on various small or large rigid or flexible substrates, is projected to grow exponentially in commercial industry. This has provided an opportunity to determine whether or not PETs could be applicable for low volume and high-reliability applications. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the current status of organic and printed electronics technologies. It reviews three key industry roadmaps- on this subject-OE-A, ITRS, and iNEMI-each with a different name identification for this emerging technology. This followed by a brief review of the status of the industry on standard development for this technology, including IEEE and IPC specifications. The report concludes with key technologies and applications and provides a technology hierarchy similar to those of conventional microelectronics for electronics packaging. Understanding key technology roadmaps, parameters, and applications is important when judicially selecting and narrowing the follow-up of new and emerging applicable technologies for evaluation, as well as the low risk insertion of organic, large area, and printed electronics

The essence of future smart houses: from embedding ICT to adapting to sustainability principles

In the context of intelligent environments, the smart houses are often pointed as one of the main constituents of smarter living environments. This study attempts to theoretically analyze case models of smart houses in order to identify their essence and characteristics. The results show that the most significant intelligent values embodied in smart houses embrace technologies of the functional automation. In fact, smart houses are substantially intertwined with integrated ICT technologies which aim to ensure comfortable living environments. Despite the identified challenges, the proliferation of smart houses into urban areas requires an integration of them in the city for creating intelligent environments. As a result, the promotion and integration of smart houses with other smarter elements of cities could archive a significant enhancement of the quality of life and a stronger urban sustainability

The effect of value add tax on economic growth and its sources in developing countries

Today the role of economic growth for its effect on social welfare is undeniable. For this reason, the factors influencing the economic growth are taken into account by policy makers and researchers. On the other hand, the VAT has been considered by most of the countries due to its numerous advantages and benefits. Hence, investigating how this type of tax affects the economic growth seems to be indispensable, particularly in developing countries. In this study, the effect of value added tax on economic growth was examined especially on the developing countries. In details, the effects of VAT on the economic growth of 19 developing countries for duration of 1995 to 2010 were investigated. For analysing the data, the GMM panel was employed because of the structure of the model. Afterwards, the effect of VAT through the channel of saving on the capital accumulation and productivity and ultimately the economic growth was examined. The results revealed that VAT has a negative effect on capital accumulation growth in the level; the positive effect of VAT on the level of economic growth seems to have been imposed through channels other than the increase of saving and its effect on capital accumulation

CHEM-Based Self-Deploying Spacecraft Radar Antennas

A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that can be compressed for storage and can later be expanded, then rigidified for use. A CHEM-based antenna according to the proposal would comprise three layers of microstrip patches and transmission lines interspersed with two flat layers of SMP foam, which would serve as both dielectric spacers and as means of deployment. The SMP foam layers would be fabricated at full size at a temperature below the SMP glass-transition temperature (Tg). The layers would be assembled into a unitary structure, which, at temperature above Tg, would be compacted to much smaller thickness, then rolled up for storage. Next, the structure would be cooled to below Tg and kept there during launch. Upon reaching the assigned position in outer space, the structure would be heated above Tg to make it rebound to its original size and shape. The structure as thus deployed would then be rigidified by natural cooling to below T

Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk

The essence of Malay vernacular houses: towards understanding the socio-cultural and environmental values

The Malay vernacular houses are inextricably intertwined with vernacular values embracing a natural harmony between architecture, people and environment. These vernacular values are comprised of socio-cultural and environmental concerns. The socio-cultural values are the spatial characteristics embodied in the functional spaces of Malay houses representing the cultural backgrounds, social requirements and actual needs of Malays. The environmental values are the spatial characteristics and locally environmental trends embodied in the functional spaces of Malay houses representing local characteristics of environment and tropic. Referring to the theoretical analysis, it is deduced that the aforementioned environmental and socio-cultural values are highly influential towards enhancing the quality of living environments inside the house leading to the enhancement of the quality of life as an expression of the degree of well-being. This study draws attention to the elaborations on the selected case models of Malay houses to scrutinize the significant vernacular values embodied in Malay houses irrespective of their type and region

Light Based Wireless Communication

The demand for high-speed, secure wireless communication is escalating, particularly in high-density environments like urban areas, and critical sectors such as healthcare and defense. Traditional Wi-Fi struggles with issues like signal congestion, electromagnetic interference, and security vulnerabilities, compromising connectivity quality. LiFi is much more suitable for areas like hospitals which contain equipment highly sensitive to electromagnetic interference, has a high bandwidth far away from standard radio waves which enables strong communication in highly congested areas. We developed a small scale, low-cost LiFi system to demonstrate a proof of concept of LiFi that grants the user full access to the internet. While a small number of companies have production LiFi to buy, it’s typically very expensive, and any proof-of-concept projects we’ve seen aren’t fast enough, or don’t have the software, to enable internet access. We used two Raspberry Pi computers to accomplish this, with one acting as a gateway connected to an internet network and the other as a client, connected with LiFi to the gateway. We were able to achieve a very slow internet access of 0.06 Mbps with this circuitry by using UART with a baud rate of 115,200 to communicate a Point-To-Point through a modulating LED and phototransistor circuit. We predicted a maximum of 16Mbps communication speed, but fell short due to the low intensity of the LEDs compared to the surrounding area, as well as the relatively low speed of UART. While this speed is painfully slow for web browsing, we were able to run an internet speed test through Chromium, and the system is more suited for lower-intensity network applications, such as SSHing into the Raspberry Pi from another internet-connected device, or pinging an ip address