Numerical estimation of thermal ignition conditions for reactive medium with Gaussian distribution of activation energy

The article investigates the solutions of the one-dimensional stationary integro-differential heat equation. The source of heat release is determined through the Gaussian distribution function of the activation energy. In such a statement, the critical conditions for the existence of a bounded solution depend on the distribution variance. With the help of numerical methods, such dependences are obtained; for their explanation, the analytical approximations of the thermal explosion theory are used.

Assessing fall velocity-maximum dimension relationships and particle size distributions for snowfall

Snowfall is an atmospheric phenomenon that can cause significant impacts to many aspects of daily life in Missouri. Further, no two snowfall events are exactly the same, as even small differences in environmental characteristics can result in differing snow crystal types dominating the event, which in turn can result in differing impacts from event to event. Therefore, it is necessary to understand snowfall behavior so that better forecasts and in situ analyses may be made. In this study, snowflake maximum dimension and fall velocity measurements were recorded using the OTT Parsivel Laser Disdrometer. In conjunction with distribution of measured maximum dimensions, RAP Analysis soundings were used to determine snow crystal type. From there, the relationships between fall velocity and maximum dimension and the particle size distributions of snowflakes from many snowfall events were analyzed. Observed relationships between fall velocity and maximum dimension were compared with previously derived relationships, and it was found that, in most cases, no single curve represented the relationship in the observed data well, with discrepancies caused by instrumentation error and lack of a single dominant crystal type. To analyze particle size distributions, several distribution functions were fit to the observed distribution using a least-squares regression method in MATLAB. It was found that, overall, the triple Gaussian distribution function performed the best in modeling particle size distributions in snow, but there were some instances where the gamma function modeled the distribution best. Further study, especially with the inclusion of field observations in addition to instrument observations, is necessary to develop a better understanding of these snowfall events.

CARGO OPTIMIZATION IN AN AIRLINE USING AGENT – BASED MODELLING

Cargo plays a very important role in the aviation industry as a supporting revenue. In Airline X, cargo supports the revenue by 4% - 6% of the total revenue. There are opportunities to optimize the cargo compartment in Airline X by analyzing every agent involved in the purpose to know the optimum cargo loaded into the compartment using Agent-Based Modelling. The method used in this research is Rejection Sampling in Monte Carlo and Agent-Based Modelling. In addition, the theory used in this research is distribution function, to determine what type of distribution that represents the agent behavior. The final result shows that with the predetermined number of iterations, which is 300 iterations, the optimal value was obtained base on the convergent result. On the other hand, the distribution of passenger and baggage described as the Gaussian Distribution Function, while the distribution of EBT described as the Negative Exponential Distribution Function. These distributions represent agent behavior.

Relationship between Damage Rate of High-Voltage Electrical Equipment and Instrumental Seismic Intensity

Based on the actual damage data of high-voltage electrical equipment in electric substations in the Wenchuan earthquake, this paper uses the cumulative Gaussian distribution function to describe the relationship between the damage rate of high-voltage electrical equipment and the instrumental seismic intensity. The instrumental seismic intensity at strong motion observation stations in the Wenchuan earthquake is calculated, and the Kriging interpolation method is used to estimate the instrumental seismic intensity at 110 kV and above voltage level substations in Mianyang, Deyang, Guangyuan, and Chengdu of Sichuan Province. A cumulative Gaussian distribution function is then used to fit the damage rate-instrumental seismic intensity relationship curve for six types of high-voltage electrical equipment such as the transformer, circuit breaker, voltage mutual inductor, current mutual inductor, isolating switch, and lightning arrester. The results show that transformers have the highest vulnerability during earthquakes, and they suffered a certain level of damage even under low instrumental intensity. The second most vulnerable equipment is the circuit breaker, followed by the lightning arrester, transformer, and isolating switch, which share a similar vulnerability curve.

IR Study on Cellulose with the Varied Moisture Contents: Insight into the Supramolecular Structure

The following article is the first attempt to investigate the supramolecular structure of cellulose with the varied moisture content by the means of Fourier-transform and near infrared spectroscopy techniques. Moreover, authors aimed at the detailed and precise presentation of IR spectra interpretation approach in order to create a reliable guideline for other researchers. On the basis of obtained data, factors indicating biopolymer crystallinity and development of hydrogen interactions were calculated and the peaks representing hydrogen bonding (7500–6000 cm−1, 3700–3000 cm−1, and 1750–1550 cm−1) were resolved using the Gaussian distribution function. Then, the deconvoluted signals have been assigned to the specific interactions occurring at the supramolecular level and the hydrogen bond length, as well bonding-energy were established. Furthermore, not only was the water molecules adsorption observed, but also the possibility of the 3OH⋯O5 intramolecular hydrogen bond shortening in the wet state was found-from (27,786 ± 2) 10−5 nm to (27,770 ± 5) 10−5 nm. Additionally, it was proposed that some deconvoluted signals from the region of 3000–2750 cm−1 might be assigned to the hydroxyl group-incorporated hydrogen bonding, which is, undoubtedly, a scientific novelty as the peak was not resolved before.

Bimodal distribution of the solar wind using data from ACE spacecraft.

<p>The main goal of this work is to separate the behavior of the two types of quiet solar wind at 1 AU: fast and slow.<br>Our approach is a bi-Gaussian distribution function, formed by the addition of two Gaussian distribution functions, where each one represents one type of wind. We check our approach by fitting the bi-Gaussian to data from ACE spacecraft. We use level 2 data measured during solar cycles 23 and 24 of different solar wind parameters, including proton speed, proton temperature, density and magnetic field. Our results show that the approach is fine and only transient events departs from the proposed function. Moreover, we can show bi modal behavior of the solar wind at 1 AU, not only for the proton speed, but also for the other analyzed parameters. We also check the solar cycle dependence of the different fitting parameters.</p>

Damage imaging that exploits multipath scattered Lamb waves

This article presents a multipath Lamb wave imaging method that leverages the extra reflections present in the recorded ultrasonic waveforms for structural prognosis. Under the ray acoustic approximation, an edge behaves like a mirror, which changes the propagation path of a wave and provides more views of the damage than can be obtained from direct scattering. To accommodate for these extra reflections, the scattering path of each wave in the residual signal is simplified as a direct scattering path from an actual or virtual transmitter (created by edge mirroring) to the damage, and then back to an actual or virtual receiver (created by edge mirroring). On this basis, the Gaussian distribution function is introduced to quantify the probabilities at each spatial node in relation to all possible damage loci. Through fusing the images obtained from all individual wave packets, the structure could be inspected with far fewer transducers compared to conventional elliptical imaging. Experimental results from carbon fiber-reinforced polymer laminates and aluminum plate are provided to illustrate the effectiveness of the imaging method, where damage is correctly detected and accurately localized even with a single transmitter–receiver pair.

Atomic Structure of Decagonal Al-Cu-Rh Quasicrystal–Revisited: New Correction for Phonons

The standard approach applies the Gaussian distribution function to estimate atomic displacements due to thermal vibrations in periodic and aperiodic systems, which is used in a form of the Debye–Waller factor during the structure refinement. Acoustic phonons provide the largest contribution to the Gaussian correction although the character of other phonon modes remains relatively unclear. In this paper, we provide an alternative description of localized and dispersionless phonons based on an assumption of the harmonic displacement distribution function, which was recently proposed for model quasicrystals, and apply this approach for a decagonal Al-Cu-Rh quasicrystal that was previously studied by Kuczera et al. in 2012. We used the same X-ray diffraction data and the statistical method of structural analysis of the aperiodic systems. The correction function for phonons takes the form of a Bessel function instead of a conventional (Gaussian) Debye–Waller factor. This allowed us to achieve R-factor of 7.2% compared to 7.9% reported in the original paper. A significant improvement of the calculated atomic composition towards experimentally obtained and minor positional changes is also reported compared to the original paper. The results show the usefulness of investigating different corrective terms for diffraction data during a structure refinement.