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51.
The integration of different energy systems, e.g., industrial and municipal, is potentially important for the efficient utilization of energy. It is important that the tools for analysing this type of integration can handle the energy systems on different levels, e.g., regional, site, plant and process levels. In this work, a framework for investigating the cost-efficient integration of large-scale energy systems is presented and tested at the UPM-Kymmene Kaukas pulp and paper plant and in the municipality of Lappeenranta, Finland. In addition to the different levels, the framework also aims to take into account several sub-problems, e.g., fuel logistic, optimal heat exchanger network and overall efficiency versus flexibility. The case in question shows that the presented framework can be used as a systematic tool for analysing the potential of integrating large energy systems and that it is able to handle both the synthesis of flexible heat exchanger networks and analyse the cost-efficiency of changes to the existing systems. 相似文献
52.
Juha Häkkinen Timo Rahkonen Juha Kostamovaara 《Analog Integrated Circuits and Signal Processing》1998,15(1):71-83
Two integrated direct I/Q modulators suitable for directupconversion with an output frequency of 950 MHz and baseband frequencies of60 to 500 kHz are fabricated in a 1.2 µm and 0.8 µm BiCMOSprocess, respectively, and their performance under various operatingconditions is discussed. The modulators use different phase shiftertopologies, one of which is based on digital CML latches and the other ondifferential pairs with resistive and capacitive emitter degeneration. Bothcircuits are operated using a single 5 V supply and they consume 50 mA or115 mA depending on the topology. The main properties of the CML modulatorare, for example, an output power of –11 ± 0.5 dBm at 100 MHzand –15 ± 2.25 dBm at 950 MHz over the temperature range of–10 to +85°C, LO suppression of 38 dBc and image rejection of41 dBc. 相似文献
53.
This study was designed to investigate the effects of three countermeasures – landscaping, building a fence and prohibitive signs – on the frequency of trespassing, which in this case means crossing the track at places where it is forbidden. At each location the official route was no more than 300 m away. The main results showed that the effect of each countermeasure on the frequency of trespassing was statistically significant. Specifically, the fencing reduced trespassing by 94.6%, followed by landscaping (91.3%) and prohibitive signs (30.7%). The majority of illegal crossings were committed alone and the persons trespassing were mostly adults and men. In addition, the results demonstrated some tendencies of how the effects of the selected countermeasures can vary with the characteristics of the trespassers. The main implication of this study is that the building of physical barriers such as landscaping or fencing is recommended for reducing trespassing. However, if the required resources are not available or the site is not suitable for such measures, the use of prohibitive signs is recommended. Further, there is a need to tailor the countermeasures to the characteristics of the trespassers in order to ensure that the most appropriate countermeasures are applied. 相似文献
54.
In this study, the ozone gas-liquid mass transfer into water in a bubble column was investigated for different pH values. The ozone volumetric mass transfer coefficient and the Henry's coefficient were determined simultaneously by parameter estimation using a nonlinear optimization method. A sensitivity analysis was conducted to obtain information on the reliability and identifiability of the estimated parameters. A minor dependence of the Henry's law constant on pH was detected at the pH range 4 to 9. 相似文献
55.
56.
Eero Eloranta Juha Hynynen Heikki Hämmäinen Juha Jahkola Ari Kyhälä Juha Räisänen 《Computers in Industry》1985,6(6):413-425
An end-user oriented workbench approach in the design of distributed production management systems (DPMS) is presented. We shall also deal with models and design of DPMS. Changes anticipated in design processes, roles and professionality required are discussed. In fact, complete structural rearrangements in the design of production management systems (PMS) are expected towards the end of this decade. The ideas presented are based on an on-going research project at Helsinki University of Technology (the so-called HUTDPMS project). 相似文献
57.
In this article, we considered the recognition of unknown shapes by maximum likelihood methods. The contour of a shape is
represented by its centroidal profile, and it is fitted by a circular autoregressive model. Two different shape recognition
problems are considered: the decision on the similarity of two unknown shapes, and the classification of an unknown shape
as one of many known shapes. Maximum likelihood decision rules for these two cases are derived. The decision rules are invariant
to translation, rotation, and size change after normalizing the estimates.
The developed algorithms are applied to classify eight classes of machine parts and eight classes of aircraft shapes. For
each class, 60 to 80 samples are generated by rotating and dilating the original shape. In the experiment, more than 98% of
machine parts are classified correctly, and more than 97% of aircraft shapes are correctly classified. This result is better
than previous model-based approaches.
Partially supported by the National Science Foundation under the grant IRI-8809391. 相似文献
58.
Eija Jms Heidi Holkeri Helena Vihinen Mats Wikstrum Marjo Simonen Bjrn Walse Nisse Kalkkinen Juha Paakkola Marja Makarow 《Yeast (Chichester, England)》1995,11(14):1381-1391
Escherichia coli β-lactamase was secreted into the culture medium of Saccharomyces cerevisiae in biologically active form, when fused to the C-terminus of the hsp150δ-carrier. The hsp150δ-carrier is an N-terminal fragment of the yeast hsp150 protein, having a signal peptide and consisting mostly of a 19 amino acid peptide repeated 11 times in tandem. Here we expressed the hsp150δ-carrier fragment alone in S. cerevisiae. Apparently due to a positional effect of the gene insertion, large amounts of the hsp150δ-carrier were synthesized. About half of the de novo synthesized carrier molecules were secreted into the culture medium, the rest remaining mostly in the pre-Golgi compartment. The extensively O-glycosylated carrier fragment was purified from the culture medium under non-denaturing conditions. Circular dichroism spectroscopy showed that it had no regular secondary structure. Nuclear magnetic resonance spectroscopy showed that a non-glycosylated synthetic peptide, the consensus sequence of the repetitive 19 amino acid peptide, also lacked secondary structure. The unstructured carrier polypeptide may facilitate proper folding and secretion of heterologous proteins attached to it. 相似文献
59.
This work deals with the heat treatment of fibers and nonoriented specimens made of the thermotropic liquid crystalline polymer Vectra A900 in the light of tensile properties and DSC measurements. In calorimetric measurements, there seem to be some differences in the effects of the treatment between macroscopically isotropic (nonoriented) and highly oriented fiber specimens. Nonisothermal treatments also produce some effects on the tensile properties, which may be attributable to the thermal history of samples. Under the conditions of this study, a multistep treatment, ending at a final stage where the temperature was higher than the original melting point of the polymer, did not cause any acceleration in the rate at which tensile properties increase. © 1993 John Wiley & Sons, Inc. 相似文献
60.
Juha Kangasrääsiö 《ISA transactions》2010,49(3):257-263
The automatic control of grammage (basis weight) in paper and board production is based upon on-line grammage measurement. Furthermore, the automatic control of other quality variables such as moisture, ash content and coat weight, may rely on the grammage measurement. The integrity of Kr-85 based on-line grammage measurement systems was studied, by performing basic calibrations with traceably calibrated plastic reference standards. The calibrations were performed according to the EN ISO/IEC 17025 standard, which is a requirement for calibration laboratories. The observed relative measurement errors were 3.3% in the first time calibrations at the 95% confidence level. With the traceable basic calibration method, however, these errors can be reduced to under 0.5%, thus improving the integrity of on-line grammage measurements. Also a standardised algorithm, based on the experience from the performed calibrations, is proposed to ease the adjustment of the different grammage measurement systems. The calibration technique can basically be applied to all β-radiation based grammage measurements. 相似文献