Oxygen-enriched combustion mechanism of lignite

In this work, thermogravimetric experiments were carried out in a thermogravi-metric analyzer under O2/N2 atmosphere with an oxygen content ranging from 21 vol.% to 70 vol.%. Malek method combined with iso-conversional method and non-isothermal method was employed to determine the burning dynamical function of lignite in high temperature burning region with different oxygen concentrations. The results indicated that the lignite has different burning dynamical function in different oxygen conditions. The combustion mechanism function of lignite belonged to 3-D model when the oxygen concentration is below 30%. The combustion mechanism of lignite belongs to a random successive nucleation growth model when the oxygen concentration is between 40% and 50%. Kinetic burning model of lignite in high burning temperature region with different oxygen concentrations was established. The kinetic parameters were obtained from the kinetic burning model of lignite using Kissinger-Akah-Sunose method.

Estimation of CO2 Emissions from Wildfires Using OCO-2 Data

The biomass burning model (BBM) has been the most widely used method for estimation of trace gas emissions. Due to the difficulty and variability in obtaining various necessary parameters of BBM, a new method is needed to quickly and accurately calculate the trace gas emissions from wildfires. Here, we used satellite data from the Orbiting Carbon Observatory-2 (OCO-2) to calculate CO2 emissions from wildfires (the OCO-2 model). Four active wildfires in Siberia were selected in which OCO-2 points intersecting with smoke plumes identified by Aqua MODIS (MODerate-resolution Imaging Spectroradiometer) images. MODIS band 8, band 21 and MISR (Multi-angle Imaging SpectroRadiometer) data were used to identify the smoke plume area, burned area and smoke plume height, respectively. By contrast with BBM, which calculates CO2 emissions based on the bottom–top mode, the OCO-2 model estimates CO2 emissions based on the top–bottom mode. We used a linear regression model to compute CO2 concentration (XCO2) for each smoke plume pixel and then calculated CO2 emissions for each wildfire point. The CO2 mass of each smoke plume pixel was added to obtain the CO2 emissions from wildfires. After verifying our results with the BBM, we found that the biases were between 25.76% and 157.11% for the four active fires. The OCO-2 model displays the advantages of remote-sensing technology and is a useful tool for fire-emission monitoring, although we note some of its disadvantages. This study proposed a new perspective to estimate CO2 emissions from wildfire and effectively expands the applied range of OCO-2 satellite data.

The Effect of Ash Cleaning Cycles on Thermal Characteristics of Moxibustion Therapy

Objective: In clinical treatment, ash cleaning is an effective way to enhance the thermal efficiency of moxibustion. Understanding the thermal characteristics of moxibustion therapy with ash cleaning is necessary to improve its clinical efficiency. Method: Temperature distributions of burning moxa sticks were measured with an infrared camera. The moxa burning duration was set at 20min with different ash cleaning cycles (3min, 4min, 5min and no ash cleaning). A moxa stick burning model with ash cleaning was built to analyze the detailed burning discipline and compared with experimental results. In addition, temperature distributions of in-vitro tissue during moxibustion with different ash cleaning cycles were obtained using thermocouples and infrared camera. Results: Ash cleaning has effectively extended the high-temperature areas of moxa sticks and accelerated the burning velocity. Shorter ash cleaning cycle led to higher average temperature of moxa sticks. The simulated results agreed well with experimental data, which indicates that the moxa stick burning model with ash cleaning is reliable to reveal the burning discipline of moxa sticks. For in-vitro tissue, ash cleaning induced obvious temperature rise at tissue surface and slight rise in deep tissue. Compared with 3 min and 5 min, the ash cleaning cycle of 4 min is the recommended value.

Abdominal fat reducing outcome of exercise training: fat burning or hydrocarbon source redistribution?

Fat burning, defined by fatty acid oxidation into carbon dioxide, is the most described hypothesis to explain the actual abdominal fat reducing outcome of exercise training. This hypothesis is strengthened by evidence of increased whole-body lipolysis during exercise. As a result, aerobic training is widely recommended for obesity management. This intuition raises several paradoxes: first, both aerobic and resistance exercise training do not actually elevate 24 h fat oxidation, according to data from chamber-based indirect calorimetry. Second, anaerobic high-intensity intermittent training produces greater abdominal fat reduction than continuous aerobic training at similar amounts of energy expenditure. Third, significant body fat reduction in athletes occurs when oxygen supply decreases to inhibit fat burning during altitude-induced hypoxia exposure at the same training volume. Lack of oxygen increases post-meal blood distribution to human skeletal muscle, suggesting that shifting the postprandial hydrocarbons towards skeletal muscle away from adipose tissue might be more important than fat burning in decreasing abdominal fat. Creating a negative energy balance in fat cells due to competition of skeletal muscle for circulating hydrocarbon sources may be a better model to explain the abdominal fat reducing outcome of exercise than the fat-burning model.

Prediction Model for Cigarette Yields Derived from Data Obtained under Two Different Machine Smoking Regimes

Summary“Tar”, nicotine and carbon monoxide (TNCO) cigarette yields determined under different smoking regimes, with and without ventilation blocking, are linearly related to the difference Δt between the smouldering time (cigarette combustion with no puffing) and the smoking time (cigarette combustion with puffing). Δt forms then the basis of yield predictions. The smoulder rate determination used in the calculation of Δt can be difficult for low ignition propensity cigarettes which present some tendency for selfextinguishment. This issue was overcome in a novel testing scheme involving the determination of number of puffs and smoking times under two different smoking regimes and inputting this data into a cigarette burning model. This enabled us to characterise the burning process and provided an extensive set of information such as the mean smoulder rate between puffs or the mass of tobacco burnt during puffs regardless of the smoking regime applied.Good correlations were observed between the mass of tobacco burnt during puffs and TNCO or B[a]P yields. Correlations provide a way to link yields from one smoking regime to another and confirm that yields determined from one regime are sufficient to establish the relationships between yields and smoking intensity. It was concluded that smoke yields for arbitrary smoking regimes can potentially be predicted by determining the puff numbers and smoking times from two different smoking regimes and the smoke yields from only one regime. This testing scheme allows a comprehensive characterisation of a cigarette at reduced cost. [Beitr. Tabakforsch. Int. 26 (2015) 320-333]

Research on the Energy Properties of the Hydro-Reactive Metal Fuel

Contrast the energy properties of many kinds of chemical propellants, it is obvious that the metal fuel reacting with water has huge superiority and vast application foreground. Under the hypothesis condition, the burning model of the metal fuel reacting with water is analyzed. The energy properties of the metal fuel are researched through the way of thermodynamics computation, containing the burning time, reaction principle, and the reacting temperature.