Energy recovering techniques for air conditioning has increased in recent years and new prod- ucts have been introduced to the market where the Membrane-based Energy Recovery Ventilator (ERV) is one promising product. The aim of this study was to evaluate a new type of membrane material for an ERV and give an analysis of the need for digital control of the air flow rate to improve efficiency. A prototype counter-flow ERV was used in the test to validate the performance under different flow conditions. The result was promising for the tested membrane material with high moisture and heat transfer. The optimisation of the flow rate was found to be superfluous, since the relation between the energy transferred by the ERV and the air flow rate was almost linear.

Syftet med studien var att studera hur fenomenet självläkning framställdes i nationell och internationell forskning. Studien omfattar tre frågeställningar: (1) Hur definieras alkoholmissbruk i artiklarna? (2) Hur definieras självläkning i artiklarna? (3) Hur framställs självläkningsprocessen i artiklarna? För att besvara dessa frågeställningar gjordes en selektiv kunskapsöversikt och en kvalitativ innehållsanalys användes som metod. Kunskapsöversikten utgjordes av tio forskningsdokument vilka omfattades av kvalitativa och kvantitativa undersökningar mellan åren 1996-2007. Studiens position är postmodern. Studiens resultat analyserades utifrån ett socialkonstruktivistiskt perspektiv. Resultatet visade att tillgång till olika personliga och sociala resurser främjade självläkningsprocessen. Resultatet visade också att innebörden av begreppen självläkning och alkoholmissbruk varierade och att det inte fanns någon enhetlig definition av dessa begrepp. De olika definitionsvariationerna resulterade i att innebörden av fenomenet självläkning blev otydlig. / The purpose of this paper was to study how the phenomenon natural recovery from alcohol misuse is presented in the national and international research. This paper includes three questions at issue: (1) How is alcohol misuse defined in the research documents? (2) How is natural recovery defined in the research documents? (3) How is the process of natural recovery presented in the research documents? To answer these questions a selective qualitative knowledge overview was made and a qualitative content analysis was used as research method. This research overview of knowledge is based on ten research documents including qualitative and quantitative studies conducted between 1996 – 2007. This study has a post modern approach and the results in this study were analyzed on the basis of social constructivist theory. Results showed that the process of natural recovery was promoted by access to personal and social resources. Results also showed that the meaning of the concepts natural recovery and alcohol misuse varied and that there was no uniform definition of these concepts. Due to the various forms of defining these concepts the meaning of the phenomenon natural recovery proved to be indistinct.

Denna uppsats kretsar kring två företags återhämtningsarbete vid uppkomsten av respektive skandal. Vidare skapas en djupare förståelse för teorin Service Recovery's betydelse och användning i praktiken. De två fallen där skandaler inträffat är grundade dels i ICA:s köttfärsskandal och dels i IKEA:s fjäderplockningsskandal.   Uppsatsen har en deduktiv ansats vilket innebär att uppsatsen utgår från befintliga teorier som sedan testas med det insamlade empiriska materialet. Den teoretiska referensramen innefattar främst Grönroos teorier kring Service Recovery och kompletteras med teorier så som Service Recovery Paradox, kundförväntningar, sociala medier och immateriell påverkan. Uppsatsens forskningsfrågor besvaras främst med hjälp av en fallstudie med två företagsanalyser samt med en enkätundersökning. Studien är av både kvalitativ och kvantitativ karaktär där kvalitativ data samlats in via en e-mail intervju med Ylva Magnusson vid IKEA, och kvantitativt via en enkätundersökning. Uppsatsen har resulterat i kännedom om hur de två företagen arbetat med att återfå kundförtroende. Uppsatsen har även gett författarna möjlighet att utveckla en ny modell av praktisk bemärkelse som behandlar processarbete inom Service Recovery.

Timing recovery is the processing of synchronizing the sampler with the received analog signal. Sampling at the wrong times can have a devastating impact on performance. Conventional timing recovery techniques are based on a decision-directed phase-locked loop (PLL). They are adequate only when the operating signal-to-noise ratio (SNR) is sufficiently high, but recent advances in error-control coding have made it possible to communicate reliably at very low SNR, where conventional techniques fail. This thesis develops new techniques for timing recovery that are capable of working at low SNR. We propose a new timing recovery scheme based on per-survivor processing (PSP), which jointly performs timing recovery and equalization, by embedding a separate PLL into each survivor of a Viterbi algorithm. The proposed scheme is shown to perform better than conventional scheme, especially when the SNR is low and the timing error is large. An important advantage of this technique is its amenability to real-time implementation. We also propose a new iterative timing recovery scheme that exploits the presence of the error-control code; in doing so, it can perform even better than the PSP scheme described above, but at the expense of increased complexity and the requirement of batch processing. This scheme is realized by embedding the timing recovery process into a trellis-based soft-output equalizer using PSP. Then, this module iteratively exchanges soft information with the error-control decoder, as in conventional turbo equalization. The resulting system jointly performs the functions of timing recovery, equalization, and decoding. The proposed iterative timing recovery scheme is shown to perform better than previously reported iterative timing recovery schemes, especially when the timing error is severe. Finally, performance analysis of iterative timing recovery schemes is difficult because of their high complexity. We propose to use the extrinsic information transfer (EXIT) chart as a tool to predict and compare their performances, considering that the bit-error rate computation takes a significant amount of simulation time. Experimental results indicate that the system performance predicted by the EXIT chart coincides with that obtained by simulating data transmission over a complete iterative receiver, especially when the coded block length is large.

The kraft pulping process has been known for decades. The focus in kraft pulping has always been on better operation of the chemical recovery system. One of the targets is on deadload (sodium sulfate (Na2SO4) and sodium carbonate (Na2CO3)) reduction in white liquor. A model based on several literature references was developed to study the effect of deadload reduction. A base model was developed based on current mill operation. This base model was compared to the deadload reduction model. Overall improvement, such as operating cost saving and revenue generation was achieved from deadload reduction. Operating cost saving involves less deadload chemical in chemical recovery system, and less water that was associated with the deadload itself. Revenue generation involves generating more steam and heat from the recovery boiler that can be used for mill purposes or energy revenue. Two important variables to achieve deadload reduction are causticizing efficiency and reduction efficiency.

No description available.

No description available.

Anecdotal evidence in disaster studies suggests that multifamily housing takes longer to recover than single family homes, but almost no studies have provided quantitative evidence to clarify this “multifamily home lag” phenomenon. This research examines the recovery of single family, duplex, and apartment complex housing in south Miami-Dade County, Florida, after 1992 Hurricane Andrew to determine if there is indeed a "multifamily home lag." This research also provides a better understanding of the factors influencing the recovery trajectories of these three housing types. The findings of this research indicate that duplexes and apartment buildings have slower recovery trajectories than single family dwellings. In addition, rental housing, housing that sustained higher levels of damage, and single family dwellings and duplexes located in predominately non-Hispanic Black neighborhoods show significantly slower recovery trajectories. The analyses specific to apartment buildings also finds that apartment buildings with fewer than 10 units have significantly slower recovery trend than apartment buildings with more than 50 units.

This thesis involves exploring enhancement of estimating the probability of a critical station blackout in nuclear power plant operations by the use of direct numerical evaluation of multidimensional nonrecovery integrals. This requires development of computational methods with data provided from South Texas Project Nuclear Operating Company (STPNOC). Several methods that are currently used in the industry to estimate such probabilities often overestimate the value substantially. The computational integral method developed in the thesis will reduce excess conservatism while maintaining plant safety standards. This computational integral is calculated using a MATLAB research code referred to generally as "STP-TAMIL" which is for South Texas Project --Texas A&M Improved LOOP. The code itself (along with the user manual) was developed in conjunction with this Thesis. STP-TAMIL is successful in reducing the estimated probability of critical station blackout by a significant amount (about 88.47 percent ) with the incorporation of recovery of offsite and onsite power for South Texas Project̕ s nuclear plants, and results were verified. This thesis also describes an asymptotic justification for to the non-recovery integral used. Applications to the industry, or STPNOC, which will use the "TAMIL" code are addressed. Some assumptions used throughout the problem suggest that if more dynamic rates or distributions are used then more recovery can be obtained, which will decrease the probability of critical station blackout. Methodology developed in this thesis will be used in future work to develop this STP-TAMIL research code into a model used industry wide in commercial nuclear power plants.

The purpose of this thesis is to experimentally determine the feasibility of an ejector based, waste heat recovery driven refrigeration system applied to the data center environment in order to reduce operational cooling costs. A comprehensive literature review is detailed to determine the current state of the ejector refrigeration research and assess the initial direction of this thesis. A simplified model was created to perform preliminary performance estimations and system sizing before constructing an experimental system apparatus to evaluate the model predictions. The pressures and temperatures used in the model and instituted in the experimental system are based on the maximum temperatures typically observed in computing servers (50-75°C). Precision controlled heaters are used to simulate the computer server heat, and R245fa is used as the working fluid. Performance results ranged from 0.06 to 0.13.