Automotive technology status and projections. Volume 2: Assessment report

Current and advanced conventional engines, advanced alternative engines, advanced power train components, and other energy conserving automobile modifications which could be implemented by the end of this century are examined. Topics covered include gas turbine engines, Stirling engines, advanced automatic transmissions, alternative fuels, and metal and ceramic technology. Critical problems are examined and areas for future research are indicated

Deriving Finite Sphere Packings

Sphere packing problems have a rich history in both mathematics and physics; yet, relatively few analytical analyses of sphere packings exist, and answers to seemingly simple questions are unknown. Here, we present an analytical method for deriving all packings of n spheres in R3 satisfying minimal rigidity constraints (≥ 3 contacts per sphere and ≥ 3n − 6 total contacts). We derive such packings for n ≤ 10 and provide a preliminary set of maximum contact packings for 10 < n ≤ 20. The resultant set of packings has some striking features; among them are the following: (i) all minimally rigid packings for n ≤ 9 have exactly 3n−6 contacts; (ii) nonrigid packings satisfying minimal rigidity constraints arise for n ≥ 9; (iii) the number of ground states (i.e., packings with the maximum number of contacts) oscillates with respect to n; (iv) for 10 ≤ n ≤ 20 there are only a small number of packings with the maximum number of contacts, and for 10 ≤ n < 13 these are all commensurate with the hexagonal close-packed lattice. The general method presented here may have applications to other related problems in mathematics, such as the Erdos repeated distance problem and Euclidean distance matrix completion problems.Engineering and Applied SciencesPhysic

WATER CONSUMPTION BEHAVIOR IN SEMI- RURAL AREAS IN THE GAZA STRIP: BEIT LAHYA TOWN AS ACASE STUDY

Groundwater is the major source of drinking water in both urban and rural areas in the Gaza Strip. Population growth and urban expansion have persistently raised the demand for water supply and consequently, greatly increased the exploitation of groundwater in the Gaza strip. The importance of this research is to investigate the water consumption behavior in semi-rural area by studying the current distribution situation, water demand and supply, the unaccounted for water and studying the effect of urban agriculture on the system efficiency. Therefore, field survey to determine the sources of water for irrigation, the agricultural area and water meter readings was conducted for continuous three periods two in summer and one in winter. Urban agriculture is one of the most persistent approaches for supplying food in the Gaza Strip. The main outcomes of the study are that; farmers use the domestic network illegally for irrigation purposes leading to high percentage of unaccounted for water. This leads to higher water consumption per capita in Beit Lahya which apparently exceeds 230 l/c/d according to water well production in year 2010 equal (6.098 MCM) and the unaccounted for water more than 60% in semi urban quarters where green houses are the main agricultural practice. The difference between supply and demand indicates that the farmers use illegal connections to irrigate the adjacent agricultural areas. The overall system efficiency for water distribution is 42.0% and 55.7% for summer and winter periods, respectively. The quarters with intensive agriculture show high percentage of unaccounted for water (73%), while the urban quarters unaccounted for water is 24%. Therefore new policy and regulations concerning water resources management should be implemented for the semi urban areas in the Gaza Strip. Key words: Water supply, Unaccounted for water, illegal connections, urban agricultur

Near term hybrid passenger vehicle development program, phase 1

Missions for hybrid vehicles that promise to yield high petroleum impact were identified and a preliminary design, was developed that satisfies the mission requirements and performance specifications. Technologies that are critical to successful vehicle design, development and fabrication were determined. Trade-off studies to maximize fuel savings were used to develop initial design specifications of the near term hybrid vehicle. Various designs were "driven" through detailed computer simulations which calculate the petroleum consumption in standard driving cycles, the petroleum and electricity consumptions over the specified missions, and the vehicle's life cycle costs over a 10 year vehicle lifetime. Particular attention was given to the selection of the electric motor, heat engine, drivetrain, battery pack and control system. The preliminary design reflects a modified current compact car powered by a currently available turbocharged diesel engine and a 24 kW (peak) compound dc electric motor

Differentiation Induces Dynamic Alterations in Mesenchymal Stem Cell Nuclear Architecture and Mechanotransduction

Mesenchymal stem cells (MSCs) are a promising cell source and widely used in a variety of regenerative applications given their multipotent nature. MSCs are subjected to various types of mechanical forces during tissue development and repair, and it is clear that, along with soluble factors, physiological forces play an important role in determining their lineage specification. However, the molecular mechanisms by which external mechanical stimuli are converted to a biological response remain unclear, and few studies have been performed to probe alterations in cell and nuclear architecture in response to physiological loading. In this thesis, we investigated relationships between MSC cellular/nuclear biophysical properties and mechanosensitivity, and determined their importance in MSC mechanotransduction. Our findings demonstrate that MSC differentiation mediated by either a soluble factor, TGF-β3 or resulting from dynamic tensile loading (DL) is accompanied by reorganization of nuclear structural elements (i.e. lamin A/C and chromatin). These changes increased nuclear mechanical properties, resulting in changes tto he manner in which MSCs respond to external mechanical perturbation. In addition, through a series of micromechanical experiments, the molecular mechanisms by which nuclear structure was altered as a consequence of load-induced MSC differentiation were elucidated. DL resulted in a rapid increase in chromatin condensation in MSCs, which depended on the activity of the histone-lysine N-methyltransferase EZH2. The ATP/purinergic signaling was a key regulator of this load induced chromatin condensation, and was mediated by acto-myosin cellular contractility. In follow on studies, we demonstrated that chromatin condensation in MSCs was regulated by interplay between purinergic signaling and RhoA/Rock activity, and that baseline TGF superfamily signaling played a role in establishing cell contractility and mediating this load-induced chromatin remodeling response. Overall, this thesis identified novel signaling pathways and mechanisms that regulate the mechanical properties of the nucleus in progenitor cells as they transition towards a differentiated state, and elucidated how dynamic loading regulates chromatin condensation to increase mesenchymal stem cell (MSC) nuclear mechanics in the absence of exogenous differentiation factors. This work has broad implications in the field of mesenchymal stem cell biology and mechanobiology, and will inform the development of engineered tissues, medical devices, and biological materials for tissue repair and regeneration

Los Angeles river revitalization and housing affordability

The Los Angeles River flows through a 52 mile stretch of Los Angeles County bringing a vital source of water to the region and affecting the personal lives of millions of people. In the beginning part of the 21 st century, community members and local governments developed plans to revitalize the watershed and bring new opportunities to the river corridor. Since that time, projects have been developed and implemented to bring new ecological functions, recreational opportunities, river accessibility, and transportation modes to the river. The new functionality of river sites brings exciting and vital changes to enhance the health of the river and the communities alongside it. However, with these new changes come possible negative externalities. The river’s new land functionality has the potential to lead to a decline in housing affordability in neighbourhoods along the river site. In cases around the world large scale revitalization efforts to green spaces have been attributed to green gentrification. A revitalized green space may result in exceptional rises in property values and rental prices. With the potential to stir displacement in the existing communities. In my case study on the Los Angeles River Revitalization I look at several indicators of housing affordability to understand how the changing river functionality may be affecting the adjacent neighbourhoods. The research utilizes data related to housing costs, rental burdens, affordable housing assistance, and the actions of stakeholders to explore any trends to emerge since the adoption of the Los Angeles River Revitalization Plan. The results of my research provide a mixed view of housing affordability around the Los Angeles River. When the entire stretch of the river is analysed for indicators of housing affordability there is no area that stands out with every available indicator. The Glendale Narrows Region of the Los Angeles Revitalization is at the greatest risk of worsening housing costs based on literature and views of stakeholders. However only a sharp increase in property values provides evidence for this using the quantitative data available

Anatomy of an ancient subduction channel in the depth range of its seismogenic coupling zone - insights from field studies in the Swiss Alps and Southern Chile

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Feasibility study of in-situ heat generation for oil reservoirs underlying the permafrost

Thesis (M.S.) University of Alaska Fairbanks, 2017Development of a heavy oil reservoir is a challenging issue in the oil industry. One of the major issues in heavy oil recovery is its high viscosity; so, using heating methods for producing oil have been developed and employed from the early 1950s. The existing relatively thick permafrost layer which overlays the heavy oil reservoirs of the North Slope of Alaska creates additional complexities for development of these heavy oil reservoirs. Applying any heating oil recovery process in regular way to these heavy oil Alaskan reservoirs would potentially jeopardize the permafrost layer. A down-hole heat generation system has been developed that uses a chemical and a special catalyst to generate heat. The effluent of this system would be steam and nitrogen. The system can be installed in a well string and at the bottom of the injector well. This thesis investigates the feasibility of employing this system for development of the heavy oil reservoirs that underlie the permafrost. The results of this study can be used for any steam injection process which uses any device for down-hole steam generation. The STARS module of the CMG reservoir simulation package is used for this study. In the model, live oil with a viscosity of about 30,000 cp is used. By examining several models with vertical and horizontal wells, a 3-D model with two horizontal injector and producer wells is ultimately constructed for final runs. Different sensitivities are run to find out the optimum operational parameters. Based on the results, a lateral well length of 800 ft in the middle of a reservoir with length of a 1250 ft is selected as a base case. Areal grid block size of 10 ft × 10 ft with the layer thickness of 10 ft in a reservoir with thickness of 50 ft is employed. To minimize the down-hole well bore temperature of the producer, just the last 50 ft (out of 800 ft of lateral length) at the toe of the well is opened to flow. Three different steam injection processes are examined: Steam Assisted Gravity Drainage (SAGD), Cyclic SAGD (CSAGD) and Cyclic Steam Stimulation (CSS). Simulation results reveal that the producer well bore temperature in optimum cases for SAGD, CSAGD and CSS is more than 140 ˚F, 110 ˚F and 100 ˚F, respectively. Also, the 10-year simulation period oil recoveries for optimum cases of SAGD, CSAGD and CSS are about 35%, 18% and 12%, respectively. On the other hand, results show applying any steam injection recovery method (SAGD, CSAGD or CSS) can only be recommended when the thickness of the overlying Sagavanirktok sand formation (which separates the permafrost from the heavy oil reservoir) is equal or more than 300 ft. The results also show that the addition of nitrogen has negative effect on the oil recovery. Based on the results, it is recommended to employ SAGD or CSAGD, but employ a system to cool the producer well-string to avoid melting the permafrost. A simple system of cooling the producer well-string is suggested

Infrastructure electronic numbering implementation in Australia

VoIP is becoming the dominant approach for telephony and this growth will continue with the upcoming introduction of 4G mobile wireless and fibre to the home networks. With the growing demand for VoIP and increased VoIP traffic, it is important to implement a system that provides interoperability between the existing telephony numbering system and the IP network device addresses. Infrastructure ENUM is one approach that may be used. This paper examines the Infrastructure ENUM implementation in Australia