Minimum energy requirements of thermally coupled distillation systems

AIChE Journal ◽  
1987 ◽  
Vol 33 (4) ◽  
pp. 643-653 ◽  
Author(s):  
Zbigniew Fidkowski ◽  
LechosłW Królikowski
Keyword(s):  
Minimum Energy ◽  
Energy Requirements ◽  
Thermally Coupled Distillation

Development of a micro-isolation valve - Minimum energy requirements, repeatability of actuation, and preliminary studies of debris generation

2000 ◽  
Author(s):  
Juergen Mueller ◽  
Stephen Vargo ◽  
Amanda Green ◽  
David Bame ◽  
Robert Orens ◽  
...  
Keyword(s):  
Minimum Energy ◽  
Energy Requirements

scholarly journals Estimating under-reporting of energy intake in dietary surveys using an individualised method

2007 ◽  
Vol 97 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
Kirsten L. Rennie ◽  
Andy Coward ◽  
Susan A. Jebb
Keyword(s):  
Physical Activity ◽  
Energy Intake ◽  
Minimum Energy ◽  
Population Based ◽  
Activity Level ◽  
Energy Requirements ◽  
Nutrition Survey ◽  
Energy Needs ◽  
Dietary Surveys ◽  
Dietary Records

Under-reporting (UR) of energy intake (EI) by self-reported dietary methods is well-documented but the methods used to estimate UR in population-based studies commonly assume a sedentary lifestyle. We compared estimated UR using individualised estimates of energy requirements with a population cut-off based on minimum energy needs. UR was estimated for 1551 adults aged 19–64 years enrolled in the National Diet and Nutrition Survey. Physical activity diaries and 7 d weighed dietary records were completed concurrently. Mean daily EI (kJ/d) was calculated from the dietary records. Reported physical activity was used to assign each subject's activity level, and then to calculate estimated energy requirements (EER) from published equations. UR was calculated both as EER – EI with an adjustment for daily EER and EI variation, and also by a population method. By the individual method UR was approximately 27 % of energy needs in men and 29 % in women, with 75 % of men and 77 % of women classified as under-reporters; by the population method 80 and 88 % were classified as under-reporters respectively. When subjects who reported their eating being affected by dieting or illness during dietary recording were excluded, UR was 25 % of energy needs in both sexes. UR was higher in overweight and obese men and women compared with their lean counterparts (P < 0·001). UR of EI must be considered in dietary surveys. The EER method allows UR to be quantified and takes into account an individual's activity level. Measures of physical activity and questions to identify under-eating during dietary recording may help to evaluate secular trends in UR.

scholarly journals Thermodynamic modelling of synthetic communities predicts minimum free energy requirements for sulfate reduction and methanogenesis

2019 ◽  
Author(s):  
Hadrien Delattre ◽  
Jing Chen ◽  
Matthew Wade ◽  
Orkun S Soyer
Keyword(s):  
Population Dynamics ◽  
Microbial Communities ◽  
Thermodynamic Model ◽  
Community Dynamics ◽  
Energy Requirement ◽  
Minimum Energy ◽  
Building Blocks ◽  
Thermodynamic Modelling ◽  
Energy Requirements ◽  
Experimental Population

ABSTRACTMicrobial communities are complex dynamical systems harbouring many species interacting together to implement higher-level functions. Among these higher-level functions, conversion of organic matter into simpler building blocks by microbial communities underpins biogeochemical cycles and animal and plant nutrition, and is exploited in biotechnology. A prerequisite to predicting the dynamics and stability of community-mediated metabolic conversions, is the development and calibration of appropriate mathematical models. Here, we present a generic, extendable thermodynamic model for community dynamics accounting explicitly for metabolic activities of composing microbes, system pH, and chemical exchanges. We calibrate a key parameter of this thermodynamic model, the minimum energy requirement associated with growth-supporting metabolic pathways, using experimental population dynamics data from synthetic communities composed of a sulfate reducer and two methanogens. Our findings show that accounting for thermodynamics is necessary in capturing experimental population dynamics of these synthetic communities that feature relevant species utilising low-energy growth pathways. Furthermore, they provide the first estimates for minimum energy requirements of methanogenesis and elaborates on previous estimates of lactate fermentation by sulfate reducers. The open-source nature of the developed model and demonstration of its use for estimating a key thermodynamic parameter should facilitate further thermodynamic modelling of microbial communities.

scholarly journals Can prescription of sip-feed supplements increase energy intake in hospitalised older people with medical problems?

2003 ◽  
Vol 90 (2) ◽  
pp. 425-429 ◽  
Author(s):  
Margaret Roberts ◽  
Jan Potter ◽  
John McColl ◽  
John Reilly
Keyword(s):  
Total Energy ◽  
Energy Intake ◽  
Controlled Trial ◽  
Geriatric Medicine ◽  
Minimum Energy ◽  
Intervention Group ◽  
Total Energy Intake ◽  
Energy Requirements ◽  
Control Group ◽  
Feed Supplements

A blinded randomised controlled trial of prescribed oral sip-feed supplements compared with routine hospital practice was undertaken in acute admissions to a geriatric medicine department. Patients were eligible for inclusion if they were admitted from home, were not obese (BMI>75th percentile), had no swallowing difficulties and were not deemed to be in the terminal stage of illness. On admission they were stratified by nutritional status (BMI<5th, >5th to <25th, >25th to <75th percentile) and randomised. The intervention group received 120 ml oral sip-feed supplement prescribed three times per d in the medicine prescription chart (22·5 g protein, 2260 kJ (540 kcal) energy/d) distributed at medication rounds for the duration of hospital stay. The control group received routine hospital care. Outcomes were patient compliance with supplement, total energy intake and nursing staff views of the method. Patients were randomised to receive supplements (n 186 of total n 381). Half had full compliance and three-quarters at least moderate compliance. Total energy intake was significantly increased, on average, in the intervention group (P=0·001). The proportion of patients meeting estimated minimum energy requirements was significantly increased (P=0·023), but was still <50 % for the sample of patients in the intervention group. The present study suggests this method is acceptable to patients and staff and improves total energy intake. However, the amount prescribed did not ensure minimum energy requirements were met in all cases.

The Energy Requirements of Trout and Perch Populations in Loch Leven, Kinross

1974 ◽  
Vol 74 ◽  
pp. 333-345 ◽  
Author(s):  
R. I. G. Morgan
Keyword(s):  
Energy Content ◽  
Minimum Energy ◽  
Laboratory Data ◽  
Ammonium Nitrogen ◽  
Specific Dynamic Action ◽  
Energy Requirements ◽  
Food Material ◽  
Trout Population ◽  
Loch Leven ◽  
Somatic Production

SynopsisThe minimum energy requirements of trout and perch populations in Loch Leven, Kinross, were calculated for the year 1970–71. Use was made of laboratory data relating to oxygen consumption and ammonium nitrogen (NH3–N) output. Estimates of the specific dynamic action (SDA) of food material were made at 5°, 10° and 15°C and used to predict periods of growth. It was found that optimum growth would take place at 10°C, as opposed to 15°C, and that negative somatic production in the overwintering trout population was due to the energy content of the food intake being less than the minimum energy requirements of metabolism.

scholarly journals Dynamic Behaviour of Thermally Coupled Distillation Arrangements: Effect of the Interconnection Flowrate

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Erick Yair Miranda-Galindo ◽  
Juan Gabriel Segovia - Hernández
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Complex Structure ◽  
Minimum Energy ◽  
Control Analysis ◽  
Thermally Coupled Distillation ◽  
Distillation Columns ◽  
Minimum Energy Consumption ◽  
Coupled Structures ◽  
Value Decomposition

Thermally coupled distillation sequences can provide significant energy savings with respect to the operation of conventional distillation columns. Coupled sequences exhibit a complex structure, with recycle streams, that appear to affect their controllability properties. One potential solution to this problem has been suggested through the operation of complex schemes under conditions that do not provide minimum energy consumption. The basic idea is that if one changes the value of the interconnection flowrate, the control properties might change as well. In this work, we analyze the dynamic behavior of two coupled structures under different operating points, including the one with minimum energy consumption. The control analysis properties are analyzed with the application of the singular value decomposition technique in all frequency domains. The results show that the controllability properties of distillation sequences may change significantly depending on the selected value of interconnection flowrate.

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