Measured Insulation Improvement Potential for Ten U.S. Army Buildings

2008 ◽  
pp. 202-202-19
Author(s):  
SN Flanders
1999 ◽  
Vol 18 (3-4) ◽  
pp. 287-296
Author(s):  
Bjørn Andersen

This paper deals with several different aspects of the concept of benchmarking in order to give the audience a basic understanding of what benchmarking is, how it is done, and what it can give in terms of improvement results. The main issues covered are definitions of benchmarking and explanations of the different types of benchmarking that exist and what implications these have, both in terms of improvement potential, difficulties, and suitability. Furthermore, ethical and legal aspects linked to benchmarking and the benchmarking wheel, a benchmarking process model explaining the phases and steps of the benchmarking study. A relatively large portion of the paper will be devoted to explaining how to carry out a benchmarking study and various pitfalls that might be encountered. The remainder of the paper will discuss the improvement results that companies that have used benchmarking actually have achieved. These range from phenomenal successes to downright failures, and the paper will explore conclusions derived from research on the topic.


2021 ◽  
Vol 11 (10) ◽  
pp. 4344
Author(s):  
Kuen-Suan Chen ◽  
Shui-Chuan Chen ◽  
Ting-Hsin Hsu ◽  
Min-Yi Lin ◽  
Chih-Feng Wu

The Taguchi capability index, which reflects the expected loss and the yield of a process, is a useful index for evaluating the quality of a process. Several scholars have proposed a process improvement capability index based on the expected value of the Taguchi loss function as well as the corresponding cost of process improvement. There have been a number of studies using the Taguchi capability index to develop suppliers’ process quality evaluation models, whereas models for evaluating suppliers’ process improvement potential have been relatively lacking. Thus, this study applies the process improvement capability index to develop an evaluation model of the supplier’s process improvement capability, which can be provided to the industry for application. Besides, owing to the current need to respond quickly, coupled with cost considerations and the limits of technical capabilities, the sample size for sampling testing is usually not large. Consequently, the evaluation model of the process improvement capability developed in this study adopts a fuzzy testing method based on the confidence interval. This method reduces the risk of misjudgment due to sampling errors and improves the testing accuracy because it can incorporate experts and their accumulated experiences.


Holzforschung ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Vebi Mimini ◽  
Vasken Kabrelian ◽  
Karin Fackler ◽  
Hubert Hettegger ◽  
Antje Potthast ◽  
...  

AbstractThe bulk use of renewable polymers is currently largely limited to cellulose and, less significantly, hemicelluloses. Technical lignins are only applied in novel materials to a rather limited extent, although bulk lignin utilization is a worldwide research object. Native lignins, which belong to the second or third most abundant biopolymers of terrestrial plants, are mostly used in the form of technical lignins from wood pulping processes; they are employed in low-performance sectors or simply burnt for the generation of energy. Technical lignins are available in huge quantities and have a large application potential, mainly in areas where their aromatic nature is of relevance. This review presents the state of the art of foamed lignin-based polymers (lignofoams) as high-performance insulation materials. In the focus of this presentation are the fundamental foaming principles and influential agents that have an improvement potential concerning the matrix interactions between technical lignins (including lignosulfonates) and a copolymer in foam composites. The different approaches for foam preparation are critically compared. In general, the reviewed papers disclose that the lignin part in foams should be less than 37%. There are significant difficulties to improve the properties of lignofoams, and thus intensive research is needed to find better formulations and new technologies.


2014 ◽  
Vol 10 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Hosain Darvishi ◽  
Mohammad Zarein ◽  
Saied Minaei ◽  
Hamid Khafajeh

Abstract The energy and exergy analysis, drying characteristics and mathematical modeling of the thin-layer drying kinetics of white mulberry using microwave drying were investigated. Results indicated that values of exergy efficiency (33.63–57.08%) were higher than energy efficiency (31.85–55.56%). Specific energy consumption increased with increasing microwave power while improvement potential decreased. The specific energy consumption and improvement potential varied from 3.97 to 6.73 MJ/kg water and 0.71 to 2.97 MJ/kg water, respectively. Also, energy efficiency decreased with decrease in moisture content and microwave power level. The best exergy and energy aspect was obtained by drying at 100 W microwave power. Drying took place mainly in warming up, constant rate and falling rate periods. The Page model showed the best fit to experimental drying data. Effective diffusivity increased with decreasing moisture content and increasing microwave power. It varied from 1.06 × 10−8 to 3.45 × 10−8 m2/s, with an energy activation of 3.986 W/g.


Author(s):  
Hongyang Hu ◽  
Ming Feng ◽  
Tianming Ren

The upscaling of turbomachinery using gas foil journal bearings (GFJBs) is limited because of their limited load capacity and dynamic stability. The improvement potential of shim foil inserted under the bump foil of such bearings is investigated in terms of better bearing performance. The arch height difference Δ hb between the shim foil and bump foil can be zero or not to attain the different effect. By considering the local hardening structural stiffness and an Initial installation clearance due to the shim foil, the static and dynamic characteristics of the novel bearing were calculated through the finite difference method (FDM) and perturbation method, respectively. In the analysis, a modified bump stiffness model considering the variable foil thickness was established, and a 2 D thick plate model was adopted for the top foil. The characteristics of novel GFJB with and without preload were compared with the traditional bearing. The results indicate that the load capacity and direct stiffness of the novel GFJB with shim foil can be increased largely, especially when there is a preload (Δ hb≠0). And the improvement is reinforced as the increment of Δ hb. Moreover, the stability threshold speed ( STS) of rotor supported by the novel GFJBs is enhanced by the preload, which means better stability. In addition, an air compressor test has also been conducted to verify the improved supporting performance of novel bearings. Based on this study it is convinced that the addition of shim foil under a GFJB's bump foil can be of practical interest in the quest of enhanced load capacity and dynamic stability. Moreover, the installation of shim foil is not affected by the working environment and could even be retrofited on the existing GFJBs.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 309 ◽  
Author(s):  
Yulong Song ◽  
Haidan Wang ◽  
Feng Cao

As a natural fluid with superior environment advantages, CO2 is used to constitute a dual transcritical system to reduce performance deterioration under high gas-cooler outlet temperature. Aiming at the system configuration, improvement potential, and optimization, the proposed system is deeply analyzed, and corresponding coupling models are presented in detail. First, the veracity of simulation models is completely verified by comparing with previous measurements. Then, the existence of the optimal intermediate temperature is validated, while the optimal values are found to increase with the augmentation in ambient and water-feed temperatures. Moreover, the negative effects of the pinch point on the heat transfer inside the gas cooler could be greatly reduced by using the dual gas cooler. Finally, a predictive correlation for optimal intermediate temperature determination with ambient and water-feed temperature as independent variables is proposed, which provides a theoretical basis for the proposed system to realize efficient control in the industrialization process.


2010 ◽  
Vol 17 (6) ◽  
pp. 409-419 ◽  
Author(s):  
Guillaume Leduc ◽  
Ignazio Mongelli ◽  
Andreas Uihlein ◽  
Françoise Nemry

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