Nel primo articolo, stimiamo l'economia sommersa di 49 paesi dal 1981 al 2005. Il nostro studio si basa sull'utilizzo dei consumi elettrici filtrati per i cambiamenti tecnologici e le variazioni nella quota del settore industriale. Contrariamente agli studi basati sul metodo MIMIC, noi otteniamo una riduzione nella dimensione dell'economia sommersa. Contrariamente a La Porta and Shleifer (2008), inoltre, identifichiamo misure di qualità istituzionale che sono significativamente correlate all'economia sommersa, pur controllando per il PIL pro-capite. L'economia non registrata non può, dunque, essere considerata una conseguenza del sotto sviluppo. Al contrario, l’attività economica sommersa è relazionata a specifici aspetti istituzionali che possono sopravvivere con la crescita economica. Inoltre, identifichiamo un forte effetto sostituzione tra il settore ufficiale e quello non ufficiale. Questo risultato ha importanti implicazioni sia per la convergenza dei redditi che per la relazione tra volatilità e crescita. Nel secondo articolo, analizziamo il ruolo di istituzioni, crescita e politiche nel determinare l’economia sommersa. La forte separazione tra assunti teorici sulle determinanti istituzionali del sommerso e le tecniche di misurazione utilizzate rappresenta il primo aspetto innovativo del lavoro. Sfruttando, inoltre, la dimensione time-series del panel, siamo in grado di meglio analizzare il nesso tra crescita del PIL ufficiale e dimensione relativa del sommerso. Il terzo aspetto innovativo dell’articolo si riferisce al contributo apportato al lungo dibattito circa il ruolo di istituzioni e politiche nel determinare i risultati economici. In terzo articolo, rovesciamo l’approccio standard tipicamente seguito nella letteratura relativa all’economia sommersa. Invece di utilizzare i dati sulla domanda di moneta per ottenere stime sulla dinamica del sommerso, analizziamo gli effetti di lungo periodo dell’economia non registrata sulla velocità di circolazione della moneta. Il nostro contributo è duplice: i) apportiamo un miglioramento alla letteratura sulle determinanti della velocità di circolazione della moneta; ii) testiamo indirettamente la credibilità delle stime del sommerso presentate nel primo articolo della tesi. / In the first paper, we estimate the unrecorded economy in 49 economies from 1981 to 2005. Our study is based on electricity consumption series which are filtered to account for technological change and for the changing weight of the energy-intensive industrial sector. In contrast with studies based on the MIMIC method, we obtain a reduction in the weight of the unobserved economy. Unlike La Porta and Shleifer (2008), we identify measures of institutional quality which are significantly related to the shadow economy even after controlling for per-capita GDP. Thus the shadow economy should not be dismissed as the unpleasant side effect of underdevelopment. Instead it is related to some specific institutional aspects that may well survive even when the economy reaches higher development stages. We identify strong substitution effects between official and unofficial sectors both in the long run and over the business cycle. This has important implications for income convergence and for the relationship between volatility and growth. In the second paper, we investigate the distinct roles played by institutions, growth and policies in determining the shadow economy. The sharp distinction between theoretical priors on the institutional determinants of the shadow economy and the technique used for its measurement is the first novel contribution of the paper. The second innovation is that, by exploiting the time series dimension of our panel, we are able to better investigate the link between official output growth and the relative size of shadow economy. The third innovation is that we can contribute to a long-standing controversy about the distinct roles of "institutions" and "policies" in determining economic outcomes. In the third paper we reverse the standard approach typically followed in the literature on the shadow economy. Instead of exploiting money demand data to extrapolate the dynamics of the shadow economy, we explore the long run effect of shadow economy measures – obtained independently from money demand functions - on money velocity. By doing this, the original contribution of the paper is twofold. First, we improve the understanding of money velocity determinants. Second, we provide an indirect test of the reliability of the estimates on the shadow economy presented in the first paper of the thesis.

With the growing power dissipation and more densely packed circuits, the issue of efficient thermal management has become crucial. The safe and reliable operations of microchips have a requirement on a junction temperature below 85??C. In order to meet the heat dissipation requirement at the level of 1 MW m???? of the next generation microchips, a new cooling approach has been proposed by combining the merits from forced convection in the microchannel and the synthetic jet impingements. A parametric study has been carried out on the operating conditions on the synthetic jet actuator, these parameters including: the frequency of the diaphragm in the actuator, the jet outlet velocity both in magnitude and the wave shape as well as the pressure difference between the channel two ends. It was found that these parameters have combined effect on the flow structure as well as the heat transfer rate in the microchannel. When the average jet velocity was at 2.36 ms??¹(Rej= 130), with a fixed pressure difference at 750 Pa, the maximum temperature in the silicon wafer has been reduced to about 343 K at both 560 and 1120 Hz, which was 2 K lower than when 280 Hz was used. However when the average jet velocity was increased by 50 %, the optimal heat transfer then occurred at 1120 Hz, the maximum temperature was reduced to 337 K, with 4 K and 5K difference of 280 and 560 Hz, respectively. Furthermore when the average jet velocity was doubled from Rej= 130, the frequency at 280 Hz achieved the lowest maximum temperature in the wafer at 336 K that was 5 K and 3 K lower than 560 Hz and 1120 Hz. The flow temperature in the actuator is an important factor which affects the heat transfer in the microchannel. In order to lower the cavity temperature and avoid the ingestion of the already mixed flow, the time portion of the ingestion and ejection phases has been altered, by reducing the ejection time and increasing the ingestion time. However this approach did not show any significant effect in the heat transfer process or decreasing the flow temperature in the cavity. However in a later study by increasing the pressure difference across the channel, the flow temperature in the cavity has been substantially reduced and the heat transfer in the channel changed significantly according to the flow structure. It was found that the high pressure in the channel could deliver the vortical structure to the hotter part of the wafer thus decreasing the maximum temperature in the silicon effectively, especially when high jet velocity was used. When high jet velocity has been used, irregular variation of the flow was found The unrepeatable feature of the flow is related to the frequency, jet velocity as well as the channel pressure difference.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.137-141).

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This study examined the longitudinal relationship between repetitions in reserve (RIR) and average concentric velocity (ACV) in the back squat and bench press exercises. Fourteen resistance-trained men were randomized into two groups (4-6RIR or 1-3RIR) and completed a six-week program. The RIR/ACV slope was significantly greater (p<0.001) in the bench press (0.027±}0.001m.s-1) than squat (0.020±}0.001m.s-1), and was steeper in 1-3RIR than 4-6RIR (p<0.001). The RIR/ACV relationship varied from set-to-set (p=0.001); however, the largest difference in ACV at the same RIR from set-to-set was only 0.044 m.s-1; likely not practically meaningful. The RIR/ACV relationship changed over time (p=0.004); however, since training was not to failure, it is unclear if this longitudinal change was due to improved RIR accuracy or a true change in the RIR/ACV relationship. Therefore, the RIR/ACV relationship is exercise-specific and practically stable from set-to-set; however, future research is needed to determine the long-term stability of this relationship. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

Tunnel ventilation is the design practice of placing exhaust fans and air inlets on opposite ends of animal production facilities and moving air through the building via negative pressure. Increasing air velocity within tunnel ventilated broiler production facilities increases sensible cooling and reduces the need for latent cooling (panting), which improves production efficiency. An air velocity measurement system was developed and measurement density analysis for quantifying air velocity distribution was performed in a 12.19 x 121.9 m commercial broiler production facility. Results showed that axial measurement distances of 3.05 m and 40 measurement points per cross-section produced the most descriptive air velocity distribution maps. Air velocity distribution, mean cross-sectional air velocity, and total facility air flow was assessed in three tunnel ventilated commercial broiler production facilities. These facilities differed in size, design, and equipment configurations (test facility 1 was 18.3 × 170.7 m, test facility 2 was 15.24 × 144.8 m, and test facility 3 was 12.19 × 121.9 m). Air velocity distribution varied within all three facilities. Normalized cross-sectional air velocity was plotted against proportion of total house length to compare the cross-sectional air velocity of the three facilities. House width and physical arrangement of the feed hoppers, heating systems, and tunnel fans are impacting air velocity uniformity and mean cross-sectional air velocity in the three broiler houses. Precision Livestock Farming (PLF) seeks to improve production efficiency and animal well-being by model based control of animal production facilities. Four broiler production facilities were assessed for spatial bird body weight (BW) variability. The facilities were 15.24 × 144.8 m solid side-wall tunnel ventilated broiler houses containing birds at 58 and 59 d of age. Significant differences in BW were found between birds residing at center house (3.47 kg average) and at the side-walls (3.38 kg average) (P = 0.025). This variability in BW could be attributed to any number of environmental, nutrient, or behavioral causes. A discussion of input/control parameters for PLF management of broiler production is presented. Quantification of performance variability within these facilities and defining models for control of input parameters is essential to making PLF management feasible.