500 research outputs found

    An integrated system of vapor-compression chiller and absorption heat pump: Experiment, modeling, and energy and economic evaluation

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    Buildings currently consume 41% of the primary energy in the United States. Among the 41% primary energy, approximate 50% are used for building heating, cooling, and water heating. Improving the efficiencies of the devices for building heating and cooling has potentials to reducing the energy consumptions. This research aims to find one solution for building energy efficiency through investigating an Integrated System of an Integrated Compression-Absorption Subcooling System (ICASS) Based upon the principle of subcooling effect, the ICASS can improve the efficiency of the cooling device but also achieve additional useful heating sources potentially used for space heating and domestic hot water. The ICASS utilizes thermal energy as a part of power inputs to reduce the dependency of electricity so that it can reduce the peak power demand. Due to the improved system efficiency and the availability of heating source, the ICASS could also improve the cost effectiveness of the system. The objectives of this research include: Objective 1) To develop the thermodynamic and heat transfer models of the ICASS for system design and performance. Objective 2) To test the performances of a test bed for data analysis and model validation. The data collected from the test bed will also contribute the fields of vapor-compression refrigeration system (VCRS) and absorption heat pump (AHP).Objective 3) To conduct different analyses of the ICASS based on the validated models. Objective 4) To evaluate the energy and economic benefits and to discover the commercial potentials of the ICASS. In order to predict the potential improvements of the ICASS, an integration of a VC and a single-effect lithium bromide AHP was modeled in the Engineering Equation Solver (EES) as a case study according to the engineering fundamentals and scientific principles. A test bed was constructed following the design models of ICASS. The test bed is located in the Herrick Labs at Purdue University, West Lafayette, IN. The VCRS, AHP, and ICASS were tested at different operation conditions and the system performances were recorded. Experimental data collected was also used to develop, adjust, and validate the models of VCRS, AHP, and ICASS. The validated models of VCRS, AHP, and ICASS were extended for system sensitivity analyses and overall system performance prediction when ICASS is used to various applications. The sensitivity analyses were able to identify the key parameters, which most influence the system performance. Since the ICASS utilizes both electricity and thermal energy as the energy inputs, exergy analysis was conducted to calculate the exergy efficiency and determine the irreversibilites of the system to address the potentials of the improvements. To compare the performance of ICASS with other equivalent systems, the separated systems of VCRS, absorption chiller, AHP, and water heater were used to identify the benefits due to the ICASS. The results showed that ICASS consumed the less energy by providing same heating and cooling than the equivalent systems. Finally, building energy simulations were carried out to evaluate the economic performance of the ICASS when it is applied to the full service restaurant. The simulation results indicated that the applications with high cooling demands and high electricity price are favorable for ICASS. Additionally, more hot water can be generated by the ICASS if the cooling demands are higher

    Demonstration of a Multistep Mechanism for Assembly of the SRP·SRP Receptor Complex: Implications for the Catalytic Role of SRP RNA

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    Two GTPases in the signal recognition particle (SRP) and its receptor (SR) control the delivery of newly synthesized proteins to the endoplasmic reticulum or plasma membrane. During the protein targeting reaction, the 4.5S SRP RNA accelerates the association between the two GTPases by 400-fold. Using fluorescence resonance energy transfer, we demonstrate here that formation of a stable SRP·SR complex involves two distinct steps: a fast initial association between SRP and SR to form a GTP-independent early complex and then a GTP-dependent conformational rearrangement to form the stable final complex. We also found that the 4.5S SRP RNA significantly stabilizes the early GTP-independent intermediate. Furthermore, mutational analyses show that there is a strong correlation between the ability of the mutant SRP RNAs to stabilize the early intermediate and their ability to accelerate SRP·SR complex formation. We propose that the SRP RNA, by stabilizing the early intermediate, can give this transient intermediate a longer life time and therefore a higher probability to rearrange to the stable final complex. This provides a coherent model that explains how the 4.5S RNA exerts its catalytic role in SRP·SR complex assembly

    Side-Effect Localization for Lazy, Purely Functional Languages via Aspects

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    Many side-effecting programming activities, such as profiling and tracing, can be formulated as crosscutting concerns and be framed as side-effecting aspects in the aspect-oriented programming paradigm. The benefit gained from this separation of concerns is particularly evident in purely functional programming, as adding such aspects using techniques such as monadification will generally lead to crosscutting changes. This paper presents an approach to provide side-effecting aspects for lazy purely functional languages in a user transparent fashion. We propose a simple yet direct state manipulation construct for developing side-effecting aspects and devise a systematic monadification scheme to translate the woven code to monadic style purely functional code. Furthermore, we present a static and dynamic semantics of the aspect programs and reason about the correctness of our monadification scheme with respect to them

    Type-Directed Weaving of Aspects for Polymorphically Typed Functional Languages

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    Incorporating aspect-oriented paradigm to a polymorphically typed functional language enables the declaration of type-scoped advice, in which the effect of an aspect can be harnessed by introducing possibly polymorphic type constraints to the aspect. The amalgamation of aspect orientation and functional programming enables quick behavioral adaption of functions, clear separation of concerns and expressive type-directed programming. However, proper static weaving of aspects in polymorphic languages with a type-erasure semantics remains a challenge. In this paper, we describe a type-directed static weaving strategy, as well as its implementation, that supports static type inference and static weaving of programs written in an aspect-oriented polymorphically typed functional language, AspectFun. We show examples of type-scoped advice, identify the challenges faced with compile-time weaving in the presence of type-scoped advice, and demonstrate how various advanced aspect features can be handled by our techniques. Lastly, we prove the correctness of the static weaving strategy with respect to the operational semantics of AspectFun

    Scaffolding Contigs Using Multiple Reference Genomes

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    Scaffolding is an important step of the genome assembly and its function is to order and orient the contigs in the assembly of a draft genome into larger scaffolds. Several single reference-based scaffolders have currently been proposed. However, a single reference genome may not be sufficient alone for a scaffolder to correctly scaffold a target draft genome, especially when the target genome and the reference genome have distant evolutionary relationship or some rearrangements. This motivates researchers to develop the so-called multiple reference-based scaffolders that can utilize multiple reference genomes, which may provide different but complementary types of scaffolding information, to scaffold the target draft genome. In this chapter, we will review some of the state-of-the-art multiple reference-based scaffolders, such as Ragout, MeDuSa and Multi-CAR, and give a complete introduction to Multi-CSAR, an improved extension of Multi-CAR

    Efficacy of multidomain interventions to improve physical frailty, depression and cognition: data from cluster- randomized controlled trials

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    BackgroundFrailty is the pre- eminent exigency of aging. Although frailty- related impairments are preventable, and multidomain interventions appear more effective than unimodal ones, the optimal components remain uncertain.MethodsWe devised multidomain interventions against physical and cognitive decline among prefrail/frail community- dwelling - ¥65- year- olds and evaluated these in complementary cluster- randomized trials of efficacy and participant empowerment. The Efficacy Study compared ~3- monthly telephone consultations vs. 16, 2 h sessions/year comprising communally partaken physical and cognitive training plus nutrition and disease education; the Empowerment Study compared the standard Efficacy Study multidomain intervention (Sessions 1- 10) vs. an enhanced version redesigned to empower and motivate individual participants. Changes from baseline in physical, functional, and cognitive performance were measured after 6 and 12 months in the Efficacy Study and after 6 months in the Empowerment Study, with post- intervention follow- up at 9 months. Primary outcomes are as follows: Cardiovascular Health Study frailty score; gait speed; handgrip strength; and Montreal Cognitive Assessment (MoCA). Secondary outcomes are as follows: instrumental activities of daily living; metabolic equivalent of task (MET); depressed mood (Geriatric Depression Scale- 5 - ¥2); and malnutrition (Mini- Nutritional Assessment short- form - ¤11). Intervention effects were analyzed using a generalized linear mixed model.ResultsEfficacy Study participants (n = 1082, 40 clusters) were 75.1 ± 6.3 years old, 68.7% women, and 64.7% prefrail/frail; analytic clusters: 19 intervention (410/549 completed) vs. 21 control (375/533 completed). Empowerment Study participants (n = 440, 14 clusters) were 75.9 ± 7.1 years old, 83.6% women, and 56.7% prefrail/frail; analytic clusters: seven intervention (209/230 completed) vs. seven control (189/210 completed). The standard and enhanced multidomain interventions both reduced frailty and significantly improved aspects of physical, functional, and cognitive performance, especially among - ¥75- year- olds. Standard multidomain intervention decreased depression [odds ratio 0.56, 95% confidence interval (CI) 0.32, 0.99] and malnutrition (odds ratio 0.45, 95% CI 0.26, 0.78) by 12 months and improved concentration at Months 6 (0.23, 95% CI 0.04, 0.42) and 12 (0.46, 95% CI 0.22, 0.70). Participant empowerment augmented activity (4.67 MET/h, 95% CI 1.64, 7.69) and gait speed (0.06 m/s, 95% CI 0.00, 0.11) at 6 months, with sustained improvements in delayed recall (0.63, 95% CI 0.20, 1.06) and MoCA performance (1.29, 95% CI 0.54, 2.03), and less prevalent malnutrition (odds ratio 0.39, 95% CI 0.18, 0.84), 3 months after the intervention ceased.ConclusionsPragmatic multidomain intervention can diminish physical frailty, malnutrition, and depression and enhance cognitive performance among community- dwelling elders, especially - ¥75- year- olds; this might supplement healthy aging policies, probably more effectively if participants are empowered.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/1/jcsm12534.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/2/10.1002_jcsm.12534_Fig_S4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/3/jcsm12534_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/4/10.1002_jcsm.12534_Fig_S2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/5/10.1002_jcsm.12534_Table_S3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/6/10.1002_jcsm.12534_Fig_S3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/7/10.1002_jcsm.12534_Appendix_S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/8/10.1002_jcsm.12534_Table_S2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/9/10.1002_jcsm.12534_Table_S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156002/10/10.1002_jcsm.12534_Fig_S1.pd

    New hybrid FMADM model for mobile commerce improvement

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    Internet of things (IoT) can provide an extensive scope of services via smart devices to promote the convenience of life. With advances being made in smart phones, enterprises are increasingly considering expanding their customer base through mobile commerce services. To promote m-commerce improvement, enterprises should organize an excellent m-commerce environment and attempt to realize user needs in the era of IoT. In a fuzzy environment of the real world, objective decision-making for m-commerce improvement is usually a FMADM problem involving feedback-effect and interdependence among the dimensions and criteria. But, many traditional decision models cannot conduct the complicated interrelationships among dimensions and criteria. This study proposes an improvement model that can promote m-commerce improvement towards achieving the aspiration level in fuzzy environment. The proposed hybrid model conducts the feedback-effect and dependence among attributes, and it combines the FDEMATEL technique, FDANP, and MFGRA methods. The empirical case study was conducted to prove the utility of the new hybrid FMADM model in evaluating an m-commerce environment. Comparative results exhibited that the proposed approach is superior to the traditional method and that it can obtain most real grey relational degree that can be used for establishing the best performance improvement strategy in reality
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