Science materials for the gifted in grades two and three

Thesis (Ed.M.)--Boston Universit

Thermal Energy Audit of the WPI Heating System

This project focuses on the winter heating issues on the WPI campus. The Bartlett Center, Higgins Labs, and Alumni Gym were chosen for the thermal energy audit. The buildings were analyzed using temperature and humidity data loggers, thermal imaging, and heat load calculators. The heating systems within each individual building were examined to determine inefficiencies that hold potential savings. Regular maintenance, valve inspections, and online suggestion forms for plant services are a few of the recommendations with short payback periods

Sustainable Soesterkwartier

The municipality of Amersfoort wants to construct an endurable and sustainable eco-town in the Soesterkwartier neighbourhood, by taking future climate change into account. The impact of climate change at the location of the proposed eco-town was studied by a literature review

Parallel Object-Oriented Algorithms for Building Performance Simulation. Application to an existing dwelling.

In the present work an existing dwelling, situated in the Netherlands, has been modeled by means of a parallel object-oriented simulation tool, called NEST-Buildings. The model is based on a pre-defined collection of elements (e.g., walls, rooms, openings, outdoors, occupants, ventilation tubes and boxes, solar radiation distributors, HVAC equipment, etc.) that are connected to each other conforming a dynamic thermal system. New configurations can be easily handled by adding or removing elements. Moreover, the building elements can be modeled at distinct levels of accuracy ranging from lumped volumes mixed with one-dimensional to detailed CFD&HT models. This approach makes possible the assessment of general-type buildings (residential, services, old, modern, etc.) using the appropriate modeling level at each component. The work is one more step in the improvement of this computer simulation tool. So far, the full simulation of the overall building model is based on block-Jacobi and Gauss-Seidel algorithms. With the current implementation, the computational time for performing practical simulations may become an important impediment as the size of the building increases. For instance, the computational expenses of a family house are far larger than those in a single apartment since the number of rooms, walls, events and so on is bigger. The last advances in this research line, including the use of optimum time stepping, proper mesh sizes, convergence criteria, loop control strategies and the use of other non-linear solvers based on the Newton method, are presented and discussed through comparative analysis of the simulated dwelling. The advances in this direction will help first to better understand the behavior of the already available algorithms and later to speed up the simulations. The second is important in the attainment of optimal designs of dwellings or other type of buildings.

Innovation and evolution of forms and materials for maximising dew collection

A year long study focusing on maximising dew collection using new and novel forms and materials commenced with a literature review and then the testing of nearly two hundred materials and forms using a dew simulation chamber. The research asserts that whereas present and past dew collection studies have focused on passive slippery, hydrophobic, inclined planar forms, that there are other forms that show potential for collecting dew. These include hydroscopic metallic and carbon foams with large interstices where dew can collect but which are also slippery and hydrophobic so that the dew can be rejected by gravity and then replaced by more dew. These types of forms could be used in semi-passive systems where people are at hand to extract the dew. Biomimesis, particularly with regards to cacti is investigated and materials with spiny / lanceolate projections show positive results as do some open foam materials. Other forms / materials derived from nature which are investigated and which require further study include airfoil shaped forms derived from beetles, corrugated and ribbed/finned shaped forms derived from leaves, particularly cacti, as well as insects. The study also investigates high emissivity materials. The testing of the forms and materials in the dew chamber provides a means for comparing their ability to collect dew. However as the dew simulation chamber is not a device specifically designed for dew research the results cannot be used definitively to predict the amounts that could be collected out doors. The research, however presents a number of potential new paths for maximising dew collection which should be taken further and tested in the field

Atomic layer deposition on porous powders with in situ gravimetric monitoring in a modular fixed bed reactor setup

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Review of Scientific Instruments 88, 074102 (2017) and may be found at https://doi.org/10.1063/1.4992023.A modular setup for Atomic Layer Deposition (ALD) on high-surface powder substrates in fixed bed reactors with a gravimetric in situ monitoring was developed. The design and operation are described in detail. An integrated magnetically suspended balance records mass changes during ALD. The highly versatile setup consists of three modular main units: a dosing unit, a reactor unit, and a downstream unit. The reactor unit includes the balance, a large fixed bed reactor, and a quartz crystal microbalance. The dosing unit is equipped with a complex manifold to deliver gases and gaseous reagents including three different ALD precursors, five oxidizing or reducing agents, and two purge gas lines. The system employs reactor temperatures and pressures in the range of 25-600 °C and 10−3 to 1 bar, respectively. Typically, powder batches between 100 mg and 50 g can be coated. The capabilities of the setup are demonstrated by coating mesoporous SiO2 powder with a thin AlOx (submono) layer using three cycles with trimethylaluminium and H2O. The self-limiting nature of the deposition has been verified with the in situ gravimetric monitoring and full saturation curves are presented. The process parameters were used for a scale-up in a large fixed bed reactor. The samples were analyzed with established analytics such as X-ray diffraction, N2 adsorption, transmission electron microscopy, and inductively coupled plasma optical emission spectrometry.DFG, 53182490, EXC 314: Unifying Concepts in Catalysi

Design package for instrumentation of the Decade 80 house in Tucson, Arizona

A design package covering instrumentation and system design for the Decade 80 House in Tucson, Arizona is presented. The solar house is instrumented for the purpose of gathering data to determine the solar heating and cooling system performance. The use of copper in the construction of the house is a first choice construction material because it conducts heat and resists corrosion better than other materials and therefore provides a more efficient and economical system. Equipment and site specifications are reported, along with floor plans showing the location of the site instrumentation hardware

Paradox of Peroxy Defects and Positive Holes in Rocks Part II: Outflow of Electric Currents from Stressed Rocks

Understanding the electrical properties of rocks is of fundamental interest. We report on currents generated when stresses are applied. Loading the center of gabbro tiles, 30x30x0.9 cm$^3$, across a 5 cm diameter piston, leads to positive currents flowing from the center to the unstressed edges. Changing the constant rate of loading over 5 orders of magnitude from 0.2 kPa/s to 20 MPa/s produces positive currents, which start to flow already at low stress levels, <5 MPa. The currents increase as long as stresses increase. At constant load they flow for hours, days, even weeks and months, slowly decreasing with time. When stresses are removed, they rapidly disappear but can be made to reappear upon reloading. These currents are consistent with the stress-activation of peroxy defects, such as O$_3$Si-OO-SiO$_3$, in the matrix of rock-forming minerals. The peroxy break-up leads to positive holes h$^{\bullet}$, i.e. electronic states associated with O$^-$ in a matrix of O$^{2-}$, plus electrons, e'. Propagating along the upper edge of the valence band, the holes are able to flow from stressed to unstressed rock, traveling fast and far by way of a phonon-assisted electron hopping mechanism using energy levels at the upper edge of the valence band. Impacting the tile center leads to h$^{\bullet}$ pulses, 4-6 ms long, flowing outward at ~100 m/sec at a current equivalent to 1-2 x 10$^9$ A/km$^3$. Electrons, trapped in the broken peroxy bonds, are also mobile, but only within the stressed volume.Comment: 33 pages, 19 figure