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The Monetary Transmission Mechanism and Business Cycles: The Role of Multi-stage Production with InventoriesDai, Tiantian 17 September 2012 (has links)
This thesis studies the role of multi-stage production for the monetary transmission mechanism. I employ a monetary search model to show how multi-stage production influences both the long run and the short run effects of money growth. Multi-stage production provides an additional channel for money growth having effects through intermediate goods between different production stages. Extending Shi's (1998) model from a single-stage to a multi-stage production model, I show that money growth rate has an unconventional long run effect on quantities per match, and the long run response of input inventory investment is different from that of output inventory investment. Contrary to classic search models, the steady state effect of money growth on the quantity of finished goods per match is not monotonic and depends on the money growth rate. Furthermore, in steady state the quantities per match first increase with the growth rate of money, before falling for large growth rates. Input inventories arise due to search frictions. Money growth also has hump-shaped real effects on steady state input inventory investment. The intermediate goods build a bridge between the labor market and the finished goods market. Intuitively, households hire more labor with higher future revenue and produce more intermediate goods in order to match the employment level. With more labor and more intermediate goods, finished goods producers can produce more when matched. As a consequence, they are stuck with more input inventories. Moreover, my model suggests that changes in the money growth rate would be one of the reasons for the decline of the inventory-to-sales ratio since the mid-1980s. Finally, I calibrate my model to quarterly US data. Contrary to other work, my model is able to replicate the stylized facts on inventory movements over the business cycle by solely relying on monetary shocks. The theoretical impulse response functions can quantitatively reproduce the corresponding empirical ones estimated in a structure autoregressive model. Moreover, the quantitative analysis supports the argument that input inventories amplify aggregate fluctuations over business cycles. / Thesis (Ph.D, Economics) -- Queen's University, 2012-09-16 20:44:21.876
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Reduction and Speciation of Monoglycerides to Produce High Quality BiodieselRapaka, Srikanth 26 July 2012 (has links)
Biodiesel is rapidly growing as a fuel of interest due to the various advantages it has over conventional diesel fuel. While the pros – non-toxic, biodegradable, low green house gas emissions seem advantageous, the major issue that plagues the use of biodiesel is its cold weather operability. Biodiesel can present challenges in cold-weather operation, because certain of its constituent compounds can form precipitates in the fuel. These precipitates can cause undesired effects like plugging of fuel filters and deposits. This issue has been attributed to the presence of impurities (mostly saturated monoglycerides, di-glycerides, soap etc) in biodiesel and has been discussed in the literature. There is a move by users and standards associations to implement more stringent norms and quality control to avoid problems in the widespread use of biodiesel. This study involves ways to reduce MG’s in biodiesel by mitigating to a greater extent the possibility of side reactions (formation of soap). The effect of selective transesterification of oil as a function of alcohol, temperature and catalyst concentration was also studied. Although saturated MG’s with high melting points are a greater source of deposits, it can be hypothesized that the polymorphic nature of unsaturated Monoglycerides could also be contributing to cold flow issues. It is hence vital to make sure the biodiesel is free from all forms of monoglycerides. It was also seen that there is very little specificity of selection of fatty acid types in the transesterification reaction and that the amount and type of MGs present in the biodiesel is reflected by the relative amount of fatty acids types present in the oil. In biodiesel derived from Canola oil, a preponderance of monoolein was found for all runs. The initial runs carried out as a two stage process using the membrane followed by batch reactor gave very low MG concentrations, well below ASTM standards.
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Reduction and Speciation of Monoglycerides to Produce High Quality BiodieselRapaka, Srikanth 26 July 2012 (has links)
Biodiesel is rapidly growing as a fuel of interest due to the various advantages it has over conventional diesel fuel. While the pros – non-toxic, biodegradable, low green house gas emissions seem advantageous, the major issue that plagues the use of biodiesel is its cold weather operability. Biodiesel can present challenges in cold-weather operation, because certain of its constituent compounds can form precipitates in the fuel. These precipitates can cause undesired effects like plugging of fuel filters and deposits. This issue has been attributed to the presence of impurities (mostly saturated monoglycerides, di-glycerides, soap etc) in biodiesel and has been discussed in the literature. There is a move by users and standards associations to implement more stringent norms and quality control to avoid problems in the widespread use of biodiesel. This study involves ways to reduce MG’s in biodiesel by mitigating to a greater extent the possibility of side reactions (formation of soap). The effect of selective transesterification of oil as a function of alcohol, temperature and catalyst concentration was also studied. Although saturated MG’s with high melting points are a greater source of deposits, it can be hypothesized that the polymorphic nature of unsaturated Monoglycerides could also be contributing to cold flow issues. It is hence vital to make sure the biodiesel is free from all forms of monoglycerides. It was also seen that there is very little specificity of selection of fatty acid types in the transesterification reaction and that the amount and type of MGs present in the biodiesel is reflected by the relative amount of fatty acids types present in the oil. In biodiesel derived from Canola oil, a preponderance of monoolein was found for all runs. The initial runs carried out as a two stage process using the membrane followed by batch reactor gave very low MG concentrations, well below ASTM standards.
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Reasoning About Multi-stage ProgramsInoue, Jun 24 July 2013 (has links)
Multi-stage programming (MSP) is a style of writing program
generators---programs which generate programs---supported by special
annotations that direct construction, combination, and execution of
object programs. Various researchers have shown MSP to be effective
in writing efficient programs without sacrificing genericity.
However, correctness proofs of such programs have so far received
limited attention, and approaches and challenges for that task have
been largely unexplored. In this thesis, I establish formal
equational properties of the multi-stage lambda calculus and related
proof techniques, as well as results that delineate the intricacies
of multi-stage languages that one must be aware of.
In particular, I settle three basic questions that naturally arise
when verifying multi-stage functional programs. Firstly, can adding
staging MSP to a language compromise the interchangeability of terms
that held in the original language? Unfortunately it can, and more
care is needed to reason about terms with free variables. Secondly,
staging annotations, as the term ``annotations'' suggests, are often
thought to be orthogonal to the behavior of a program, but when is
this formally guaranteed to be the case? I give termination
conditions that characterize when this guarantee holds. Finally, do
multi-stage languages satisfy extensional facts, for example that
functions agreeing on all arguments are equivalent? I develop a
sound and complete notion of applicative bisimulation, which can
establish not only extensionality but, in principle, any other valid
program equivalence as well. These results improve our general
understanding of staging and enable us to prove the correctness of
complicated multi-stage programs.
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High performance building blocks for wireless receiver: multi-stage amplifiers and low noise amplifiersFan, Xiaohua 15 May 2009 (has links)
Different wireless communication systems utilizing different standards and for multiple
applications have penetrated the normal people's life, such as Cell phone, Wireless LAN,
Bluetooth, Ultra wideband (UWB) and WiMAX systems. The wireless receiver normally
serves as the primary part of the system, which heavily influences the system performance.
This research concentrates on the designs of several important blocks of the receiver;
multi-stage amplifier and low noise amplifier.
Two novel multi-stage amplifier typologies are proposed to improve the bandwidth and
reduce the silicon area for the application where a large capacitive load exists. They were
designed using AMI 0.5 m µ CMOS technology. The simulation and measurement results
show they have the best Figure-of-Merits (FOMs) in terms of small signal and large signal
performances, with 4.6MHz and 9MHz bandwidth while consuming 0.38mW and 0.4mW
power from a 2V power supply. Two Low Noise Amplifiers (LNAs) are proposed, with one designed for narrowband
application and the other for UWB application. A noise reduction technique is proposed for
the differential cascode Common Source LNA (CS-LNA), which reduces the LNA Noise
Figure (NF), increases the LNA gain, and improves the LNA linearity. At the same time, a
novel Common Gate LNA (CG-LNA) is proposed for UWB application, which has better
linearity, lower power consumption, and reasonable noise performance.
Finally a novel practical current injection built-in-test (BIT) technique is proposed for the
RF Front-end circuits. If the off-chip component Lg and Rs values are well controlled, the
proposed technique can estimate the voltage gain of the LNA with less than 1dB (8%) error.
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Effect of Aging Heat Treatments on Ni52Ti48 Shape Memory AlloyAkin, Erhan 2010 August 1900 (has links)
Ni-rich NiTi shape memory alloys (SMAs) are capable of attaining a wide range
of transformation temperatures depending on the heat treatment conditions and superior
thermo-mechanical cycling stability, which are desired for repeated solid-state actuation.
High Ni-content Ni-rich SMAs have very low transformation temperatures in a
solutionized condition due to the high Ni-content of the matrix. Slow cooling (furnacecooling)
from solutionizing temperature and additional aging heat treatments result in the
formation of Ni-rich precipitates such as Ni4Ti3, Ni3Ti2 and Ni3Ti and increase
transformation temperatures above ambient by depleting excess Ni from the matrix.
However, the precipitates do not undergo a martensitic phase transformation and they
decrease the transformation strain by reducing the volume fraction of the material capable
of transforming. Meanwhile, recent preliminary work shows that Ni3Ti precipitates
dominate fatigue failure.
The objectives of the present study are: (1) to eliminate Ni3Ti but still have Ni4Ti3
precipitates, which are responsible for the dimensional stability and increase
transformation temperatures, (2) to investigate the effect of heat treatments on the
transformation strain, and (3) to select single variant Ni4Ti3 precipitates through
constrained aging for the formation of oriented internal stress and eventually obtain twoway
shame memory effect (TWSME) and enhanced dimensional stability. Based on these
objectives, the effect of aging heat treatment on transformation temperatures,
microstructural evolution, and shape memory behavior were investigated for a Ni52Ti48
shape memory alloy (SMA) by using differential scanning calorimetry (DSC), optical
microscopy, scanning electron microscopy (SEM), and thermo-mechanical testing,
including isobaric heating-cooling experiments under various stress levels.
It was observed that solutionizing at 900 degree C for 24 hours eliminated Ni3Ti type
precipitates, but additional aging heat treatments are needed to form Ni4Ti3 precipitates to
increase transformation temperatures. Furnace-cooling and additional aging heat
treatment results in the multi-stage martensitic transformation due to chemical and stress
inhomogeneities in the microstructure. Aging of the controlled furnace-cooled material at
400 degree C for 48 hours resulted in the highest transformation temperatures among all
processing conditions investigated due to the combination of Ni3Ti precipitates and 27 percent
volume fraction of the Ni4Ti3 precipitates, which led to the depletion of Ni from the
transforming matrix. However, since overaging results in losing coherency of the
precipitates, dimensional stability during isobaric thermal cycling was negatively
impacted.
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Multi-stage linear slot virtual impactor for concentration of bioaerosolsConerly, Shawn Charles 16 August 2006 (has links)
Two linear slot virtual impactor arrangements were developed and investigated in this study. Both arrangements encompassed two-stage impaction for concentration of bioaerosols. The first arrangement consisted of eight linear slot impactors in parallel for the first stage with the designed dimensions of 87 mm (3.4Â) for the throat length, 0.305
mm (.012Â) for the accelerator throat width, and 0.457 mm (.018Â) for the receiver throat width. The second stage contained a single unit with the designed dimensions of 71 mm (2.8Â) for the throat length, 0.36 mm (0.014Â) for the accelerator throat width, and 0.49mm (0.019Â) for the receiver throat width. The second arrangement contained a single
impactor for the first stage with a designed throat length of 87 mm (3.4Â), a designed accelerator throat width of 0.43 mm (.017Â), and a designed receiver throat width of 0.63mm (.025Â). The second stage also contained a single impactor with a designed throat length of 8.73 mm (3.4Â), a designed accelerator throat width of .43 mm (.017), and a designed receiver throat width of 0.63 mm (0.25Â). To verify the tolerances of the machined impactors, optical measurements were made. Both arrangements were subjected to liquid and solid particle tests and have a theoretical concentration factor of 100X. The arrangements were tested at flow rates that ranged from 10 L/min to 1000 L/min, where the collection efficiency of the minor flow was determined. An unknown acoustical phenomenon was present during aerosol tests at elevated flow rates causing low minor flow collection efficiencies. In order to
test the impactors at elevated flow rates, the acoustical generation phenomenon was systematically studied and suppressed. The cutpoint for the first arrangement was 1.3µm AD, and the cutpoint for the second arrangement was 1.0 µm AD. The average Stk50 for both arrangements was 0.71. The throat velocity through the impactors ranged from 21.8 m/s to 73 m/s, and the peak efficiency for these specific throat velocities ranged from 99% to 74%, respectively.
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Map based visual design process for multi-stage gear drivesBandaru, Nishant 26 July 2012 (has links)
The primary objective of this research is to develop a visual design process for gear trains with multiple stages of reduction and varying configurational architectures. One of the main challenges in the design of such gear trains is in the sizing of the individual gears such that high levels of performance are obtained in spite of constraints due to different gear configurations. Formal design procedures that successfully meet this challenge are developed. A key contribution of this research is the utilization of these design procedures to create sets of three-dimensional design maps. The design procedures help a designer manage more than 20 design parameters in designing for a broad range of gear train requirements (Rated torque capacity, Volume, Weight, Inertia, Responsiveness, Torque Density etc.) while accounting for assembly constraints. Each set of design maps corresponds to a given set of design parameters, some of which are held fixed and some of which are put in the hands of the designer. The latter set of design parameters are termed in this research as design knobs. They can be ‘tuned’ by a designer in order to generate new sets of design maps. The idea is that a designer, using the design information conveyed to him/her graphically through a given set of design maps, is able to then tune the design knobs to generate an updated set of design maps which reflect design solutions that are more desirable in terms of the application requirements. By adjusting the design knobs and looking at updated design maps, a designer is able to quickly assess the effect of his/her design decisions. The end result is that a single designer is empowered with the ability to quickly arrive at a preliminary design of a gear train that satisfies the design requirements. This preliminary design would be a good starting point for more detailed design development. / text
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Optimized multi-stage amplifier compensation method for wide load variationsMarijanovic, Srdjan 30 October 2012 (has links)
Due to variations in process, voltage, and temperature (PVT), amplifiers are almost solely designed for use in a negative feedback loop. The feedback loop mitigates the effect of PVT, however maintaining stability becomes the main design challenge. Further, multi-stage amplifiers with high open-loop gain are used for powering headphone speakers in modern portable electronics. As there are many different headphone manufacturers and compatibility specifications, headphone amplifiers are subjected to a wide variation in capacitive and resistive loads, which further complicates the stability upkeep. This thesis explores a two-stage (Common-Gate Feedback) and three-stage (Impedance Adapting Compensation) amplifier topology with respect to performance under wide load variations. For both compensation topologies, an analytical analysis is presented, followed by a design proposal for a headphone amplifier application. Finally, the trade-offs for maintaining stability under varying loads are discussed. / text
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Reduction and Speciation of Monoglycerides to Produce High Quality BiodieselRapaka, Srikanth January 2012 (has links)
Biodiesel is rapidly growing as a fuel of interest due to the various advantages it has over conventional diesel fuel. While the pros – non-toxic, biodegradable, low green house gas emissions seem advantageous, the major issue that plagues the use of biodiesel is its cold weather operability. Biodiesel can present challenges in cold-weather operation, because certain of its constituent compounds can form precipitates in the fuel. These precipitates can cause undesired effects like plugging of fuel filters and deposits. This issue has been attributed to the presence of impurities (mostly saturated monoglycerides, di-glycerides, soap etc) in biodiesel and has been discussed in the literature. There is a move by users and standards associations to implement more stringent norms and quality control to avoid problems in the widespread use of biodiesel. This study involves ways to reduce MG’s in biodiesel by mitigating to a greater extent the possibility of side reactions (formation of soap). The effect of selective transesterification of oil as a function of alcohol, temperature and catalyst concentration was also studied. Although saturated MG’s with high melting points are a greater source of deposits, it can be hypothesized that the polymorphic nature of unsaturated Monoglycerides could also be contributing to cold flow issues. It is hence vital to make sure the biodiesel is free from all forms of monoglycerides. It was also seen that there is very little specificity of selection of fatty acid types in the transesterification reaction and that the amount and type of MGs present in the biodiesel is reflected by the relative amount of fatty acids types present in the oil. In biodiesel derived from Canola oil, a preponderance of monoolein was found for all runs. The initial runs carried out as a two stage process using the membrane followed by batch reactor gave very low MG concentrations, well below ASTM standards.
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