An Examination Of The Adaptive Random Search Technique

Random search procedures have recently been successfully applied to the optimization of a variety of chemical engineering problems, including optimization of chemical processes by flow sheet simulation. These procedures represent the independent variables as random variables described by probability distributions. The adaptive random search procedure centers the distribution for each variable about the best search point found and examines this region for a better point. Thus, this technique has the ability of continuously moving the search region toward the optimum, which is particularly advantageous in following constraints. This study examines the efficiency of the adaptive random search technique as applied to six different problems, which have been previously solved by various other techniques. Copyright © 1976 American Institute of Chemical Engineer

The space shuttle launch vehicle aerodynamic verification challenges

The Space Shuttle aerodynamics and performance communities were challenged to verify the Space Shuttle vehicle (SSV) aerodynamics and system performance by flight measurements. Historically, launch vehicle flight test programs which faced these same challenges were unmanned instrumented flights of simple aerodynamically shaped vehicles. However, the manned SSV flight test program made these challenges more complex because of the unique aerodynamic configuration powered by the first man-rated solid rocket boosters (SRB). The analyses of flight data did not verify the aerodynamics or performance preflight predictions of the first flight of the Space Transportation System (STS-1). However, these analyses have defined the SSV aerodynamics and verified system performance. The aerodynamics community also was challenged to understand the discrepancy between the wind tunnel and flight defined aerodynamics. The preflight analysis challenges, the aerodynamic extraction challenges, and the postflight analyses challenges which led to the SSV system performance verification and which will lead to the verification of the operational ascent aerodynamics data base are presented

Impaired contextual modulation of memories in PTSD: an fMRI and psychophysiological study of extinction retention and fear renewal

Post-traumatic stress disorder (PTSD) patients display pervasive fear memories, expressed indiscriminately. Proposed mechanisms include enhanced fear learning and impaired extinction or extinction recall. Documented extinction recall deficits and failure to use safety signals could result from general failure to use contextual information, a hippocampus-dependent process. This can be probed by adding a renewal phase to standard conditioning and extinction paradigms. Human subjects with PTSD and combat controls were conditioned (skin conductance response), extinguished, and tested for extinction retention and renewal in a scanner (fMRI). Fear conditioning (light paired with shock) occurred in one context, followed by extinction in another, to create danger and safety contexts. The next day, the extinguished conditioned stimulus (CS+E) was re-presented to assess extinction recall (safety context) and fear renewal (danger context). PTSD patients showed impaired extinction recall, with increased skin conductance and heightened amygdala activity to the extinguished CS+ in the safety context. However, they also showed impaired fear renewal; in the danger context, they had less skin conductance response to CS+E and lower activity in amygdala and ventral-medial prefrontal cortex compared with combat controls. Control subjects displayed appropriate contextual modulation of memory recall, with extinction (safety) memory prevailing in the safety context, and fear memory prevailing in the danger context. PTSD patients could not use safety context to sustain suppression of extinguished fear memory, but they also less effectively used danger context to enhance fear. They did not display globally enhanced fear expression, but rather showed a globally diminished capacity to use contextual information to modulate fear expression

Concurrent Verbal Encouragement and Wingate Anaerobic Cycle Test Performance in Females: Athletes vs. Non-Athletes

International Journal of Exercise Science 5(3) : 239-244, 2012. To examine the effect of concurrent verbal encouragement on the performance of the WAnT in female athletes vs. female non-athletes. College-age female subjects were recruited where ten of the subjects were intercollegiate athletes (ATH, n1=10) and the nine were non-athletes (NON, n2=9). The WAnT was novel to all subjects and the subjects were blinded to the study’s purpose. Prior to the experimental trials, subjects were measured for body composition and performed a familiarity WAnT trial without verbal encouragement. Subjects then performed the WAnT twice, once with concurrent verbal encouragement (VE) and once without (NVE), in a balanced cross-over design. Peak (PP) and mean power (MP), and total work (TW) were compared between ATH and NON across VE and NVE using an ANOVA (1 between, 1 within), α=0.05. ATH and NON did not differ (p\u3e0.05) in age or body composition with the exception of fat-free mass which differed significantly (ATH=53.7±6.6, NON=46.1±5.7 kg) (p\u3c0.05). A significant (p\u3c0.05) main effect for ATH/NON was observed where ATH outperformed NON when pooled across VE/NVE trials for PP (ATH=13.0±1.4, NON=11.3±1.7 W·kg-1), MP (ATH=7.7±1.1, NON=6.7±0.9 W·kg-1) and TW (ATH=232±35, NON=201±26 J·kg-1). When pooled across all subjects (ATH and NON), the VE/NVE trials did not differ (p\u3e0.05) for PP (VE=12.4±1.7, NVE=12.0±1.9 W·kg-1), MP (VE=7.3±1.1, NVE=7.2±1.2 W·kg-1) and TW (VE=219±33, NVE=215±35 J·kg-1). The ATH/NON interaction with VE/NVE was not significant (p\u3e0.05). Concurrent verbal encouragement does not affect performance on the WAnT in females, nor does it affect WAnT performance in female athletes and non-athletes differently

Concurrent Verbal Encouragement and Wingate Anaerobic Cycle Test Performance in Females: Athletes vs. Non-Athletes

Previous research has shown that concurrent verbal encouragement improves performance on the Wingate Anaerobic Cycle Test (WACT), a 30-s supramaximal exercise protocol, in male non-athletes. This effect has not previously been examined in athletes or females. Consistently, athletes and females display a more self-determined motivational profile than non-athletes and males, suggesting verbal encouragement to be of lesser consequence to athletes and females. PURPOSE: To examine the effect of concurrent verbal encouragement on the performance of the WACT in female athletes vs. female non-athletes. METHODS: Nineteen college-age female subjects were recruited where ten of the subjects were active intercollegiate athletes (ATH, n1=10) and the remainder were non-athletes (NON, n2=9). The WACT was novel to all subjects and the subjects were blinded to the purpose of the study. Prior to participation in the experimental trials, subjects were measured for body composition and performed a familiarity WACT trial without verbal encouragement. Subjects then performed the WACT twice, once with concurrent verbal encouragement (VE) and once without (NVE), in a balanced cross-over design. All WACT trials were performed at least one week apart. Peak power (PP), mean power (MP), and total work (TW) were compared between ATH and NON across VE and NVE using an ANOVA (1 between, 1 within), α=0.05. RESULTS: ATH and NON did not differ significantly (p\u3e0.05) with regard to age or body composition with the exception of fat-free mass which differed significantly (ATH=53.7±6.6, NON=46.1±5.7 kg)(p\u3c0.05). As expected, a significant (p\u3c0.05) main effect for ATH/NON was observed where ATH outperformed NON when pooled across VE/NVE trials for PP (ATH=13.0±1.4, NON=11.3±1.7 W·kg-1), MP (ATH=7.7±1.1, NON=6.7±0.9 W·kg-1) and TW (ATH=232±35, NON=201±26 J·kg-1). However, when pooled across all subjects (ATH and NON), the VE/NVE trials did not differ significantly (p\u3e0.05) for PP (VE=12.4±1.7, NVE=12.0±1.9 W·kg-1), MP (VE=7.3±1.1, NVE=7.2±1.2 W·kg-1) and TW (VE=219±33, NVE=215±35 J·kg-1). Additionally, the ATH/NON interaction with VE/NVE was not significant (p\u3e0.05). CONCLUSION: Concurrent verbal encouragement does not affect performance on the WACT in females, nor does it affect WACT performance in female athletes and non-athletes differently

Impacts of EV battery production and recycling

Electric vehicles batteries use energy and produce environmental residuals when they are produced and recycled. This study estimates, for four selected battery types (sodium-sulfur, nickel-metal hydride, nickel-cadmium, and advanced lead-acid), the impacts of production and recycling of the materials used in electric vehicle batteries. These impacts are compared, with special attention to the locations of the emissions. It is found that the choice among batteries for electric vehicles involves tradeoffs among impacts. Nickel-cadmium and nickel-metal hydride batteries are similar, for example, but energy requirements for the production of cadmium electrodes may be higher than those for metal hydride electrodes, while the latter may be more difficult to recycle

Energy and Environmental Impacts of Electric Vehicle Battery Production and Recycling

Electric vehicle batteries use energy and generate environmental residuals when they are produced and recycled. This study estimates, for 4 selected battery types (advanced lead-acid, sodium-sulfur, nickel-cadmium, and nickel-metal hydride), the impacts of production and recycling of the materials used in electric vehicle batteries. These impacts are compared, with special attention to the locations of the emissions. It is found that the choice among batteries for electric vehicles involves tradeoffs among impacts. For example, although the nickel-cadmium and nickel-metal hydride batteries are similar, energy requirements for production of the cadmium electrodes may be higher than those for the metal hydride electrodes, but the latter may be more difficult to recycle

Material and energy flows in the materials production, assembly, and end-of-life stages of the automotive lithium-ion battery life cycle

This document contains material and energy flows for lithium-ion batteries with an active cathode material of lithium manganese oxide (LiMn{sub 2}O{sub 4}). These data are incorporated into Argonne National Laboratory's Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, replacing previous data for lithium-ion batteries that are based on a nickel/cobalt/manganese (Ni/Co/Mn) cathode chemistry. To identify and determine the mass of lithium-ion battery components, we modeled batteries with LiMn{sub 2}O{sub 4} as the cathode material using Argonne's Battery Performance and Cost (BatPaC) model for hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles. As input for GREET, we developed new or updated data for the cathode material and the following materials that are included in its supply chain: soda ash, lime, petroleum-derived ethanol, lithium brine, and lithium carbonate. Also as input to GREET, we calculated new emission factors for equipment (kilns, dryers, and calciners) that were not previously included in the model and developed new material and energy flows for the battery electrolyte, binder, and binder solvent. Finally, we revised the data included in GREET for graphite (the anode active material), battery electronics, and battery assembly. For the first time, we incorporated energy and material flows for battery recycling into GREET, considering four battery recycling processes: pyrometallurgical, hydrometallurgical, intermediate physical, and direct physical. Opportunities for future research include considering alternative battery chemistries and battery packaging. As battery assembly and recycling technologies develop, staying up to date with them will be critical to understanding the energy, materials, and emissions burdens associated with batteries

Effects of cooking on radiocesium in fish from the Savannah River: exposure differences for the public

Understanding the factors that contribute to the risk from fish consumption is an important public health concern because of potential adverse effects of radionuclides, organochlorines, other pesticides, and mercury. Risk from consumption is normally computed on the basis of contaminant levels in fish, meal frequency, and meal size, yet cooking practices may also affect risk. This study examines the effect of deep-frying on radiocesium (137Cs) levels and risk to people fishing along the Savannah River. South Carolina and Georgia have issued consumption advisories for the Savannah River, based partly on 137Cs. 137Cs levels were significantly higher in the cooked fish compared to the raw fish on a wet weight basis. Mean 137Cs levels were 0.61 pCi/g (wet weight basis) in raw fish, 0.81 pCi/g in cooked-breaded, and 0.99 pCi/g in cooked-unbreaded fish. Deep-frying with and without breading resulted in a weight loss of 25 and 39%, while 137Cs levels increased by 32 and 62%, respectively. Therefore, the differences were due mainly to weight loss during cooking. However, the data suggest that risk assessments should be based on cooked portion size for contaminant analysis, or the risk from 137Cs in fish will be underestimated. People are likely to estimate the amounts of fish they eat based on a meal size of the cooked portion, while risk assessors determine 137Cs levels in raw fish. A conversion factor of at least two for 137Cs increase during cooking is reasonable and conservative, given the variability in 137Cs levels. The data also suggest that surveys determining consumption should specifically ask about portion size before or after cooking and state which was used in their methods