Manufacturing flexibility is a difficult to quantify concept that defies universal definition. This paper presents a novel fuzzy-logic approach for measuring manufacturing flexibility that exploits linguistic variables for quantifying pertinent factors affecting commonly utilized flexibility types. Towards this end, we identify and measure the contribution of specified state variables towards the assumed flexibility types in order to compute an overall flexibility index for a generic manufacturing system. The suggested framework provides a convenient end user approach amenable to software implementation that is exemplified through the development of a prototypical software tool called “Flexibility Evaluator”. 相似文献
Leakage power minimization has become an important issue with technology scaling. Variable threshold voltage schemes have become popular for standby power reduction. In this work we look at another emerging aspect of this potent problem which is leakage power reduction in active mode of operation. In gate level circuits, a large number of gates are not switching in active mode at any given point in time but nevertheless are consuming leakage power. We propose a fine-grained forward body biasing (FBB) scheme for active mode leakage power reduction in gate level circuits without any delay penalty. Our results show that our optimal polynomial time FBB allocation algorithm results in 70.2% reduction in leakage currents. We also present an exact standard-cell placement driven FBB allocation algorithm that effectively reduces the area penalty using the post-placement area slack and results in 56.5%, 62.8% and 66.1% reduction in leakage currents for 0%, 4% and 8% area slack, respectively. Furthermore, we present a heuristic to solve the standard-cell placement driven FBB allocation problem that is computationally efficient and results in leakage within 2% of that from the exact formulation. 相似文献
The absorption of CO2 from LFG in different weight concentration ammonia solution and metal salts (Zinc and Barium) is investigated in this study. Addition of metal salts results in useful metal carbonates when LFG is passed through the solution. Barium salts show a better potential of removing CO2 as compared to Zinc salts. Addition of Barium salts to ammonia solution results in a new absorbent as no study has been focused on it till date. Also metal salts are added to alkaline wastewater which not only decreases the pH of the wastewater but also useful metal carbonates are obtained from wastewater when LFG is passed through it. Different parameters like CO2 loading, reaction rate and change in pH are investigated. Formation of carbonates is proved by using SEM and XRD analysis. Raman spectroscopy was performed on the discarded liquid after removal of carbonates to understand the formation of bicarbonates, carbonates and carbamates. 相似文献
The subcontinuum energy transport mechanism in solids can be explained by the Lattice Boltzmann Method (LBM), a discrete representation of the Boltzmann Transport Equation (BTE). The present study focuses on a detailed comparison of the LBM and BTE. Results reveal that at continuum scale, the LBM follows the BTE almost precisely. However, as the device dimensions are reduced, approaching the ballistic limit, the LBM deviates from the BTE results in terms of thermal property estimation. The inherent nonisotropic lattice configuration has a dominant contribution to the performance of the LBM. A threshold length scale is also proposed for successful implementation of the LBM solver. 相似文献
In earlier research, conversion efficiency of 10.4% (AM1.5) and 9.9% (AM0) has been achieved on small area CuInxGa1−xS2 (CIGS2) solar cell on 127 μm thick stainless steel substrate. The area of research is mainly focused on studying CIGS2 thin films as solar cell absorber material and growing high efficiency cells on ultralightweight and flexible metallic foils such as 127 μm thick stainless steel and SiO2 coated 25 μm thick Ti foils. This paper presents the scaling up process of CIGS2 thin film substrate from 2.5 × 2.5 cm2 to 10 × 10 cm2. Initial scaling up efforts focused on achieving uniform thickness and stress-free films. Process of scaling up consisted of refurbishment of selenization/sulfurization furnace, design and fabrication of scrubber and enlargement of new CdS deposition setup. The scaling up from 2.5 × 2.5 cm2 to 10 × 10 cm2 substrate size has laid the foundation for PV Materials Lab of Florida Solar Energy Center becoming the nucleus of a pilot plant. 相似文献
Estimation of terrestrial water budget at global and regional scales are essential for efficient agricultural water management, flood predictions, and, hydrological modeling. In hydrological modeling, it is a challenging task to quantify the major hydrological components like runoff, evapotranspiration (ET), and total water storage (TWS) due to improper and limited availability of detailed meteorological datasets. Furthermore, there has been no consensus to answer a-decade-long critical question that a less data-intensive models can be an alternate to robust data-intensive models in data scarce conditions. This study aims at multi-model approach over the single models usage for representing the hydrological behaviour in the Kangsabati River Basin (KRB), India. It is done by applying the standard model selection criteria over various hydrological models. Two hydrological models are selected, a semi- distributed model, Variable Infiltration Capacity (VIC-3 L), and a conceptually lumped model, Identification of unit Hydrograph and Component flows from Rainfall, Evapotranspiration and Streamflow (IHACRES). Both models were calibrated against the observed daily discharge at the KRB outlet for the period of 2001–2006 and validated for 2008–2010. The results show that both VIC-3 L and IHACRES produce reasonable runoff estimates at daily and monthly time scale in the KRB. The ET estimates show that VIC-3 L and IHACRES captured the seasonal variations with the percent change of 0.4% and 6.6% respectively. As IHACRES is simpler, parsimonious, fewer parameters, and better performances, it can be useful for hydrological modeling in data-scarce regions.
Hydrological responses corresponding to the agricultural land use alterations are critical for planning crop management strategies, water resources management, and environmental evaluations. However, accurate estimation and evaluation of these hydrological responses are restricted by the limited availability of detailed crop classification in land use and land cover. An innovative approach using state-of-the-art Variable Infiltration Capacity (VIC) model is utilized by setting up the crop-specific vegetation parameterization and analyse the effect of uniform and heterogeneous agricultural land use over the hydrological responses of the basin, in the Kangsabati River Basin (KRB). Thirteen year simulations (1998–2010) based on two different scenarios i.e., single-crop in agricultural land use (SC-ALU) and multi-crop in agricultural land use (MC-ALU) patterns are incorporated in the model and calibrated (1998–2006) and validated (2007–2010) for the streamflow at Reservoir and Mohanpur in the KRB. The results demonstrated that the VIC model improved the estimates of hydrological components, especially surface runoff and evapotranspiration (ET) at daily and monthly timescales corresponding to MC-ALU than SC-ALU (NSC?>?0.7). Grid-scale ET estimates are improved after incorporating heterogeneous agricultural land use (NSC?>?0.55 and R2?>?0.55) throughout the period of 1998–2010. This study improves our understanding on how the change in agricultural land use in the model settings alters the basin hydrological characteristics, and to provide model-based approaches for best management practices in irrigation scheduling, crop water requirement, and management strategies in the absence of flux towers, eddy covariance, and lysimeters in the basin.