Outdoor to indoor mobile coverage is evaluated for differentfrequencies in two scenarios, a single building scenario and a cityenvironment. A new model for outdoor to indoor propagation issuggested, connecting existing, highly detailed indoor and outdoorray-tracing propagation models. The model is compared to previous,site specific as well as statistical, propagation models. Resultsconclude that the new model gives higher path gain for edge users inthe single building scenario, whereas results from the city scenarioare inconclusive. Furthermore, results from the single buildingscenario suggest that indoor coverage is possible at 5 GHz and belowfor most buildings, whereas for the city scenario indoor coverage at5 GHz will be possible only for buildings without metally coatedwindows. Achieving indoor coverage at 30 GHz is highly problematicfor all cases, and it is concluded that indoor base stations arenecessary if frequencies of 10 GHz and above are to be used infuture mobile networks. In addition, an indoor analysis is made to verify existing lossper meter indoor models. It is concluded that such models are oftenoptimistic, although their assumption of log-normal shadowing remainvalid, at least for closed offices. Furthermore, the assumption ofloss as a linear function of distance might be unfeasible for higherfrequencies, where a breakpoint in the linear model was observed ata distance of roughly 10 meters.

The use of cleaning products can lead to indoor concentrations of toxic air contaminants above regulatory levels. Studies show that the use of cleaning products is related to adverse respiratory health effects in adults ranging from irritation to asthma. Yet exposure to these chemicals is poorly understood. This thesis summarizes the current state of knowledge of inhalation exposure to toxic chemicals in consumer cleaning products. A new two-compartment model that treats personal air space as distinct from bulk room air is presented. The model accounts for air exchange between the two compartments and fresh air, dynamic source characteristics (i.e., the time-varying liquid concentrations and emission rates of pollutants within a mixture), the characteristics of chemical use (e.g., how frequently a cleaning chemical is applied to a new area), and reactive chemistry with ozone. The model’s applicability is restricted by limited data available for parameterization. Key components that are missing include composition data for consumer cleaning products and activity patterns. Extensive effort went into calculating the air exchange rate between the two zones. Twelve computational fluid dynamic simulations and two model scenarios were completed. The predicted concentration in the inner-zone (Cin) was divided by the room concentration predicted by the traditional well-mixed model (Cwm). Concentration ratios (Cin/Cwm) ranged from 1.1 to 700. In terms of real cleaning events, results indicate that the beginning (where the only emission source is near the person) of events taking place in large indoor environments with high air exchange rates are the situations for which well-mixed models are most likely to fail in predicting actual exposures. / text

Ozone is a known pollutant harmful to human health and a strong oxidizer. The use of Zero Energy Air Purification (ZEAP) materials has proven to be a viable option to reduce indoor ozone concentrations during short-term experiments. The current study focuses on activated carbon mats, and three green building materials (perlite-based ceiling tile, recycled carpet, and painted gypsum wallboard. The effects of long-term exposure of these materials to real environments on ozone removal capability, primary emissions (in absence of ozone) of carbonyls and secondary emissions of carbonyls following the use of ozone were studied. A field study was completed over a six-month period and laboratory testing was intermittently conducted on material samples. The results show sustained ozone removal capability for all materials except carpet. Carbonyl emissions are low for activated carbon in all field locations. Painted gypsum wallboard and perlite-based ceiling tile have similar overall emissions over the six-month period, but distributed differently in time, while carpet has large initial emission rates that decline rapidly but remain high compared to the other materials. This study confirms that activated carbon mats are a viable ZEAP material and that perlite-based ceiling tile could also be considered as such as it balances good ozone removal capability and low by- product emissions. / text

No description available.

This dissertation was conducted as part of the efforts related to WPI's Precision Personnel Location (PPL) project, the purpose of which is to locate emergency personnel in hazardous indoor environments using radio location techniques. The current PPL system prototype uses a radio transmitter worn by the personnel, indoors, and receivers on reference units, outdoors. This dissertation proposes a new system architecture with bidirectional radio transmissions to replace the current unidirectional system architecture. This allows the development of a synchronization scheme that can extract additional Time of Arrival (TOA) information for estimating the location of personnel. This dissertation also describes an extension of the multi-signal fusion technique previously used that incorporates this TOA information. At the cost of a more complicated mobile unit design, resultant benefits of this approach include rejection of signal reflectors as solutions, improved accuracy with limited reference unit geometries, improved noise rejection and significant computation reduction. In this dissertation the mathematical underpinnings of this approach are presented, a performance analysis is developed and the results are evaluated in the context of experimental data.

This thesis was conducted as part of the efforts related to WPI's Precision Personnel Location (PPL) project, the purpose of which is to locate emergency personnel in hazardous indoor environments using radio location techniques. A unique signal processing algorithm, sART, developed within the PPL project provides means to determine precise position estimates of a wideband transmitter from multipath corrupted signals captured by distributed receivers. This algorithm has synchronization requirements that can not be met without extraordinary expense and complexity by direct means. This thesis develops digital signal processing that achieves the necessary synchronization to satisfy the sART algorithm requirements without additional implementation complexity. The mathematical underpinnings of this solution are introduced and the results are evaluated in the context of experimental data.

<p>Title: Veingeskolan F - Investigation of the indoor environment and a structural analysis</p><p>Method: Complete analysis of structural drawings to determine if the school have been constructed correctly. In my teorethical studies of the drawings I must seek out points that may have been damaged from moisture, this contains a full survey of the foundation, walls and ceiling. To strenghten the data collected from the drawings I must visit the school and do field investigations to find out if the school has any problems with the indoor environment.</p><p>Analysis: I determined that we had some damages on specific places, these damages was caused by leaking roofs, a carpet that was tarnished by strong sunlight in connection with some type of glue and also the ventilation that may have been drawing malodorous air from a shaft in the foundation.</p><p>Conclusion: I was able to see that the decision to demolish the school was quite drastic, if the county would have done continuous fixups on the construcion when the employes had complained maybe the action to the tear the school down would have been unnecessary. The lack of communication between the two parts lead up to the decision to demolish and build a complete new school.</p>

Experiments were conducted to determine the photocatalytic degradation of three types of gas-phase compounds, NOX, VOCs, and chloramines, by TiO2 impregnated tiles. The oxides of nitrogen NO and NO2 (NOx) have a variety of negative impacts on human and environmental health ranging from serving as key precursors for the respiratory irritant ozone, to forming nitric acid, which is a primary component of acid rain. A flow tube reactor was designed for the experiments that allowed the UV illumination of the tiles under exposure to both NO and NO2 concentrations in simulated ambient air. The reactor was also used to assess NOx degradation for sampled ambient air. The PV values for NO and NO2 were 0.016 cm s-1 and 0.0015 cm s-1, respectively. For ambient experiments a decrease in ambient NOx of ~ 40% was observed over a period of roughly 5 days. The mean PV for NOx for ambient air was 0.016 cm s-1 and the maximum PV was .038 cm s-1. Overall, the results indicate that laboratory conditions generally simulate the efficiency of removing NOx by TiO2 impregnated tiles. Volatile organic compounds (VOC's) are formed in a variety of indoor environments, and can lead to respiratory problems (US EPA, 2010). The experiments determined the photocatalytic degradation of formaldehyde and methanol, two common VOCs, by TiO2 impregnated tiles. The same flow tube reactor used for the previous NOX experiments was used to test a standardized gas-phase concentration of formaldehyde and methanol. The extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68% reduction in methanol. The deposition velocities (or the photocatalytic velocities, PV) were estimated for both VOC's. The PV for formaldehyde was 0.021 cm s-1, and the PV for methanol was 0.026 cm s-1. These PV values are slightly higher than the mean value determined for NO from the previous experiments which was 0.016 cm s-1. The results suggest that the TiO2 tiles could effectively reduce specific VOC levels in indoor environments. Chlorination is a widespread form of water disinfection. However, chlorine can produce unwanted disinfection byproducts when chlorine reacts with nitrogen containing compounds or other organics. The reaction of chlorine with ammonia produces one of three chloramines, (mono-, di-, and tri-chloramine). The production of chloramines compounds in indoor areas increases the likelihood of asthma in pool professionals, competitive swimmers, and children that frequently bath in indoor chlorinated swimming pools (Jacobs, 2007; Nemery, 2002; Zwiener, 2007). A modified flow tube reactor in conjunction with a standardized solution of monochloramine, NH2Cl, determined the photocatalytic reactions over the TiO2 tiles and seven concrete samples. The concrete samples included five different concrete types, and contained either 5 % or 15 % TiO2 by weight. The PV for the tiles was 0.045 cm s-1 for the tiles manufactured by TOTO Inc. The highest PV from the concrete samples was 0.054 cm s-1. Overall the commercial tiles were most efficient at reducing NH2Cl, compared to NOX and VOC compounds. However, the concrete samples had an even higher PV for NH2Cl than the tiles. The reason for this is unknown; however, distinct surface characteristics and a higher concentration of TiO2 in the concrete may have contributed to these findings.

<p>Objectives. The main objective of the present thesis was to evolve a controlled intermittent velocity field and to examine the impact of this type of dynamic indoor climate on human’s psychology and physiology. The prediction was that intermittent velocity variation could provide occupants with the desired cooling without causing draught and that this intermittent change of the indoor climate would influence peoples’ affect and cognitive performance.</p><p>Methods. All experiments were performed in a classroom-like environment where groups of subjects were exposed to a temperature increase and step changes in air velocity. The changes or intermittent variations in air velocity consisted of elevated speed during five minutes, which were repeated three times. To reduce the influence of individual thermal preferences all measures were collected twice and the statistical analyses were based on the change scores in these measures.</p><p>Results. The obtained results showed that, intermittent velocity variation may provide occupants with the desired cooling without causing draught. Subjects exposed to velocity variations were significantly less affected by the temperature rise in the room, compared to the control group. Moreover, the method reduced the expected increase of occupants who perceived the temperature condition as uncomfortable. The findings concerning air movements demonstrate that very few perceived the condition as draughty, after being exposed to the three high velocity pulses.</p><p>The results concerning affect showed a significant effect on high activation, in the temperature range 21 - 24^oC when the velocity variations made the subjects rate the temperature as slightly lowered over time, they kept their level of activation. In the higher temperature interval, 25 - 27^oC, unactivated unpleasantness increased and activated pleasantness decreased significantly more in subjects in the constant velocity condition than it did for subjects in the velocity variation condition. In sum, all results concerning affect, the significant ones and tendencies point in the same direction. Subjects exposed to velocity variation report changes, over time, indicating higher activation and more positive feelings.</p><p>No differences in cognitive performances were shown between the air velocity conditions. However, a tendency to a significant result (p = 0.10) in an attention task was shown, indicating that subjects in the velocity variation condition increased their speed in a short-term memory search, compared to subjects in the constant velocity condition.</p><p>In the temperature range 21- 24^oC, where the perception of the room temperature was measured at 0, 5 and 10 minutes respectively after the last high velocity period, the difference in MTV scores between the two groups, did decrease over time. Ten minutes after the last pulse the difference in MTV scores between the two groups was not significant. This suggests that the high velocity period should be repeated every10 to 15 minutes to keep the expected rise in subjects who judged the thermal conditions as uncomfortable down.</p><p>The skin temperature was not affected neither by the rise in ambient temperature (from 21 to 24^oC over 80 minutes) nor the periods (3 x 5 minutes) of high velocity. A consequence of this result is that the human temperature regulation system permitted an increased heat loss during the high velocity pulse, and hence a reduction of the body’s internal stored heat. For uncovered body parts the increase in heat loss was 20 % during the high velocity pulse. Summarised over the whole exposure time the three pulses produced a total energy loss that was only 2 % higher compared to constant low velocity.</p>

Title: Veingeskolan F - Investigation of the indoor environment and a structural analysis Method: Complete analysis of structural drawings to determine if the school have been constructed correctly. In my teorethical studies of the drawings I must seek out points that may have been damaged from moisture, this contains a full survey of the foundation, walls and ceiling. To strenghten the data collected from the drawings I must visit the school and do field investigations to find out if the school has any problems with the indoor environment. Analysis: I determined that we had some damages on specific places, these damages was caused by leaking roofs, a carpet that was tarnished by strong sunlight in connection with some type of glue and also the ventilation that may have been drawing malodorous air from a shaft in the foundation. Conclusion: I was able to see that the decision to demolish the school was quite drastic, if the county would have done continuous fixups on the construcion when the employes had complained maybe the action to the tear the school down would have been unnecessary. The lack of communication between the two parts lead up to the decision to demolish and build a complete new school.