Initial Warm-up Period Research Articles

Calibration and Uncertainty Analysis for Modelling Runoff in the Tambo River Basin, Peru, Using Sequential Uncertainty Fitting Ver-2 (SUFI-2) Algorithm

Basin-scale simulation is fundamental to understand the hydrological cycle, and in identifying information essential for water management. Accordingly, the Soil and Water Assessment Tool (SWAT) model is applied to simulate runoff in the semi-arid Tambo River Basin in southern Peru, where economic activities are driven by the availability of water. The SWAT model was calibrated using the Sequential Uncertainty Fitting Ver-2 (SUFI-2) algorithm and two objective functions namely the Nash-Sutcliffe simulation efficiency (NSE), and coefficient of determination ( R2) for the period 1994 to 2001 which includes an initial warm-up period of 3 years; it was then validated for 2002 to 2016 using daily river discharge values. The best results were obtained using the objective function R2; a comparison of results of the daily and monthly performance evaluation between the calibration period and validation period showed close correspondence in the values for NSE and R2, and those for percent bias (PBIAS) and ratio of standard deviation of the observation to the root mean square error (RSR). The results thus show that the SWAT model can effectively predict runoff within the Tambo River basin. The model can also serve as a guideline for hydrology modellers, acting as a reliable tool.

Cold Start Dead Sensor

This article explains how electrostatic discharge from oil can destroy sensitive and crucial engine components. All thermomechanical power systems contain a dielectric fluid – namely the circulating lubricant oil – where its circulation can create friction and cause a static electric charge to build up. The charge can induce voltage spikes in portions of the circulation manifold during the initial warm-up period. The spike can destroy a sensitive component such as a sensor or microprocessor, and if that component is critical to operation, the engine will shut down. Flow electrification of liquids has been a source of numerous industrial hazards, primarily in the petroleum and power industries. This effect occurs in improperly grounded systems carrying fuels, lubricating oils, and other hydrocarbon liquids. That’s why some commercial gasoline fuel hoses in the United States have an attached ground wire to dissipate electric charge accumulation during fueling operations and there exist regulations to shut off the engine when pumping fuel into a vehicle.

Cardiac rehabilitation: impact of graded exercise in the recovery period following myocardial infarction

Cardiac rehabilitation: impact of graded exercise in the recovery period following myocardial infarction Simon WhiteSchool of Pharmacy, Keele University, Staffordshire, UKAbstract: This paper reviews the impact of graded exercise undertaken as part of a cardiac rehabilitation (CR) program in the recovery period following a myocardial infarction, focusing on how CR may be best provided and the evidence-base relating to exercise-based CR. Essential components of CR are considered here to include education about healthy behavior, lifestyle modification where necessary (especially in relation to smoking, diet, and physical exercise), medical risk factor management, use of cardioprotective medicines and implantable devices, and psychosocial health management. It is argued that the totality of the evidence continues to demonstrate benefits of exercise-based CR in terms of mortality and morbidity, despite the debate about the magnitude of that benefit. However, given the wide variance in the quality and nature of CR service provision, there is no guarantee that patients eligible for CR will benefit fully. In line with national and international standards, CR should be tailored to the patient's individual needs, but structured exercise is recommended for most patients. Exercise sessions, whether based in hospital, in the community, or at home, should be designed to vary the frequency, intensity, duration, and type of exercise. They must include an initial warm-up period, before a conditioning period, and finish with a cool-down period. Patients should be taught to self-monitor so that they can exercise safely on their own. In designing interventions to support patients to change health behavior, health professionals should recognize that patients may only make lifestyle modifications to aspects of lifestyle perceived as causes of their cardiovascular disease and so, for example, may not do the recommended amount of exercise if they do not perceive lack of exercise to be a cause of their cardiovascular disease.Keywords: cardiovascular disease, public health, education programs, cardiac rehabilitation, lifestyle change, physical activity

Effects of heated seats in vehicles on thermal comfort during the initial warm-up period

Eight subjects participated in a subjective experiment of eight conditions to investigate the effects of heated seats in vehicles on skin temperature, thermal sensation and thermal comfort during the initial warm-up period. The experimental conditions were designed as a combination of air temperature in the test room (5, 10, 15, or 20 °C) and heated seat (on/off). The heated seat was effective for improving thermal comfort during the initial warm-up period when air temperature was lower than 15 °C. Use of heated seats prevented decreases in or increased toe skin temperature. Heated seats also increased foot thermal sensation at 15 and 20 °C. Optimal thermal sensation in contact with the seat was higher when air temperature was lower. Optimal skin temperature in contact with the seat back was higher than that with the seat cushion. Moreover, these optimal skin temperatures were higher when air temperature was lower.

Whole Body Deletion of AMP-activated Protein Kinase β2 Reduces Muscle AMPK Activity and Exercise Capacity

AMP-activated protein kinase (AMPK) β subunits (β1 and β2) provide scaffolds for binding α and γ subunits and contain a carbohydrate-binding module important for regulating enzyme activity. We generated C57Bl/6 mice with germline deletion of AMPK β2 (β2 KO) and examined AMPK expression and activity, exercise capacity, metabolic control during muscle contractions, aminoimidazole carboxamide ribonucleotide (AICAR) sensitivity, and susceptibility to obesity-induced insulin resistance. We find that β2 KO mice are viable and breed normally. β2 KO mice had a reduction in skeletal muscle AMPK α1 and α2 expression despite up-regulation of the β1 isoform. Heart AMPK α2 expression was also reduced but this did not affect resting AMPK α1 or α2 activities. AMPK α1 and α2 activities were not changed in liver, fat, or hypothalamus. AICAR-stimulated glucose uptake but not fatty acid oxidation was impaired in β2 KO mice. During treadmill running β2 KO mice had reduced maximal and endurance exercise capacity, which was associated with lower muscle and heart AMPK activity and reduced levels of muscle and liver glycogen. Reductions in exercise capacity of β2 KO mice were not due to lower muscle mitochondrial content or defects in contraction-stimulated glucose uptake or fatty acid oxidation. When challenged with a high-fat diet β2 KO mice gained more weight and were more susceptible to the development of hyperinsulinemia and glucose intolerance. In summary these data show that deletion of AMPK β2 reduces AMPK activity in skeletal muscle resulting in impaired exercise capacity and the worsening of diet-induced obesity and glucose intolerance.

Superheated Steam Drying of Distillers' Spent Grains on a Single Inert Particle

The article presents the results of drying a distillers’ spent grain fraction (DSG) of a stillage in superheated steam (SS). The study aimed at determination of the effect of SS parameters on drying kinetics of DSG deposited as a pasty layer on the 50-mm solid Teflon sphere. Drying was conducted at approximately 2 to 4 kPa above the atmospheric pressure, with steam temperature ranging from 110 to 160°C and steam velocity of 1 m/s. Samples were dried with SS at different processing times ranging from 60 to 360 min, depending on the SS temperature. During the initial warmup period of SS processing, the pasty DSG gained moisture due to steam condensation on its surface, which further evaporated at constant material temperature (apparent constant rate period). That period ended as soon as the condensate evaporated and temperature of the product passed the saturation point of steam. Only the falling drying rate period was observed. The drying rates increased from 0.02 to 0.83 L/min with the increase in steam temperature from 110 to 160°C, respectively. The effective diffusivity of moisture in DSG increased with the increase in steam temperature according to the Arrhenius-type relationship. The values of the effective diffusivity ranged between 3.24 × 10−10 and 2.48 × 10−9 m2/s, with the activation energy of 53.74 kJ/mol.

Optical fiber coupled light emitting diode based absorbance detector with a reflective flow cell

We present a versatile, optical fiber coupled light emitting diode (LED) light source based flow-through optical absorbance detector. The LED source is readily changeable. Optical fibers are used to carry light from the electronics/display unit to a reflective flow-through cell and back. The cell can thus be located remotely from the electronics unit and the umbilical connection is not susceptible to electrical noise. The noise level of this detector with LEDs of different emission maxima were observed to be in the range of 3–20 μAU under actual use conditions, with a maximum short term drift of 4 μAU/min after the initial warm-up period. When the analyte absorbance is well matched with the source emission characteristics, the detector response is linear with concentration over at least two orders of magnitude. The liquid flow path through the cell is linear with a large exit aperture such that bubbles are not trapped in the optical path. The optical arrangement is such that the incident light crosses the liquid flow orthogonally and is reflected back by a rear mirror to the receiver fiber. This arrangement reduces the refractive index sensitivity by an order of magnitude relative to conventional Z-path flow cells.

A hybrid power source for pulse power applications

Abstract Portable 12 V power supplies are used extensively for communications and power tool applications. These devices demand fast response times of the power supply. Fuel cells are generally best suited to continuous power applications and require an initial warm-up period, although they offer the prospect of increased operational duration over a battery for a given weight of portable system. This paper investigates the combination of specific energy performance from the fuel cell system with the specific power and response time of the battery. Two separate hybrid systems have been developed and tested; a planar, 20-cell, polymer electrolyte membrane fuel cell (PEMFC) stack together with either a lead–acid or nickel/cadmium battery; and a conventional 20-cell, bipolar, PEMFC stack. Both systems have been tested under pulse-load conditions at temperatures between −20°C and +40°C, and for comparison, the individual components have undergone similar tests. The hybrid systems have successfully operated continuously for several weeks under load profiles that the fuel cell alone could not sustain.

An Ultrasonic Instrument for Continuous Measurement of Sodium Levels in Fast Breeder Reactors

An ultrasonic level measurement system which provides a continuous digital readout over a range of 3 to 180 inches, was tested in 500°F liquid sodium. The system proved to be accurate and reliable, required no initial warm-up period and experienced no long term drift. Modifications can extend the present operating temperatures to greater than 1200°F.