Fire Scenarios Inside a Room-and-Pillar Underground Quarry Using Numerical Modeling to Define Emergency Plans

Underground fires are still one of the most significant risks in mines today. In order to manage this risk, it is necessary to know the potential evolution of a fire and the effects it can have on people and other objects. Ventilation plays an essential role in the development of a fire; it also influences the propagation of toxic fumes and the variation of temperatures in all other areas of a mine. Currently, it is possible to jointly analyze, through numerical modeling, the ventilation circuit and a fire for different possible scenarios in order to define, in detail, the emergency plans that need to be adopted. In this paper, a numerical study was conducted via the use of Ventsim Software (an integrated mine and tunnel ventilation numerical package that is able to analyze airflows, pressures, heat, gases, and fires along all of a defined circuit over time using an iterative procedure to solve Kirchhoff’s current law). Furthermore, in this study, it is illustrated how the joint numerical modeling of the ventilation circuit and fire, when applied to an underground gypsum mine in the northwest of Italy, provides all the elements necessary to define the safety procedures that should be adopted in standard conditions as well as during an emergency due to a fire. More specifically, it was possible to identify suitable escape routes depending on the location of the possible fire and the time available for the staff to be able to evacuate safely

Epidemiological aspects of cutaneous leishmaniasis in Iran

Background: The prevalence of Cutaneous Leishmaniasis (CL) has been reported as 1.8 to 37.9 in different provinces of Iran. However, enough knowledge about epidemiological aspects of CL disease is needed to launch a proper program to plan control and preventive strategies about the disease. Objectives: The present study aimed to determine the epidemiological aspect of CL in Iran during the first 6 months of 2014. Patients and Methods: In this cross-sectional study, all cases of CL reported to centers for disease control and prevention (CDC) by state health departments from March 2014 to September 2014 were included. Descriptive statistics including frequency tables, measures of central value, and measures of dispersion to describe the study variables were used to analyze data. Area maps were created using ArcView GIS v. 3.3. Results: Most of the CL cases were observed in eastern, central, and southern provinces. Two thousand thirty-one cases (55.13) were male and 2,306 (62.6) were living in urban areas. The mean age of the patients was 27 ± 18 years old. More than 31 of them were under 14 years of age. Also, 3570 individuals (96.91) were new cases. more wounds were seen so that 62.75 of the wounds were on the hands, 24.8 in the head and neck, and 2.7 in the body. Conclusions: According to the epidemiological features of CL in Iran, Providing a uniform mechanism for control and prevention of this disease is not possible. Thus, initial actions such as staff training, screening in endemic areas, and treatment of patients with urban leishmaniasis as a reservoir for the disease can be useful, according to the geographical position and carrier. © 2015, Infectious Diseases and Tropical Medicine Research Center

In vitro cytotoxic and anti-cancer effects of body wall for sea cucumber (Holothuria leucospilota)

In recent years efforts to find bioactive compounds from live organisms especially marine animals have been increased. In the present study, the anticancer and cytotoxic effects of sea cucumber body walls (Holothuria leucospilota) were investigated. For this purpose, sea cucumbers were collected from Larak Island at depths of 10 to 30 m and extraction process was done with methanol and diethyl ether solvent which then concentrated by rotary evaporator (40℃) following lyophilization with vacuum freeze dryer. XTT method was used to investigate anticancer and cytotoxic effects of body wall extracts. The results showed that the methanolic extract could prevent proliferation of human oral epidermoid carcinoma cells (KB) at concentrations of 100 and 500 μg/ml. The diethyl etheric extract also could prevent proliferation of KB at 500 μg/ml concentration. Overall result showed that sea cucumber body wall had a strong cytotoxic effect on normal cell line (Human embryonic kidney cell [HEK]) which can be used as potent cytotoxic material. However these extracts did not show significant therapeutic value against KB cells

Advanced data mining in field ion microscopy

Field ion microscopy (FIM) allows to image individual surface atoms by exploiting the effect of an intense electric field. Widespread use of atomic resolution imaging by FIM has been hampered by a lack of efficient image processing/data extraction tools. Recent advances in imaging and data mining techniques have renewed the interest in using FIM in conjunction with automated detection of atoms and lattice defects for materials characterization. After a brief overview of existing routines, we review the use of machine learning (ML) approaches for data extraction with the aim to catalyze new data-driven insights into high electrical field physics. Apart from exploring various supervised and unsupervised ML algorithms in this context, we also employ advanced image processing routines for data extraction from large sets of FIM images. The outcomes and limitations of such routines are discussed, and we conclude with the possible application of energy minimization schemes to the extracted point clouds as a way of improving the spatial resolution of FIM

The prediction model for additively manufacturing of NiTiHf high-temperature shape memory alloy

NiTi-based alloys are one of the most well-known alloys among shape memory alloys having a wide range of applications from biomedical to aerospace areas. Adding a third element to the binary alloys of NiTi changes the thermomechanical properties of the material remarkably. Two unique features of stability and high transformation temperature have turned NiTiHf as a suitable ternary shape memory alloys in various applications. Selective laser melting (SLM) as a layer-based fabrication method addresses the difficulties and limitations of conventional methods. Process parameters of SLM play a prominent role in the properties of the final parts so that by using the different sets of process parameters, different thermomechanical responses can be achieved. In this study, different sets of process parameters (PPs) including laser power, hatch space, and scanning speed were defined to fabricate the NiTiHf samples. Changing the PPs is a powerful tool for tailoring the thermomechanical response of the fabricated parts such as transformation temperature (TTs), density, and mechanical response. In this work, an artificial neural network (ANN) was developed to achieve a prediction tool for finding the effect of the PPs on the TTs and the size deviation of the printed parts

Online learning for infectious disease fellows-A needs assessment

BACKGROUND: Online resources and social media have become increasingly ubiquitous in medical education. Little is known about the need for educational resources aimed at infectious disease (ID) fellows. METHODS: We conducted an educational needs assessment through a survey that aimed to describe ID fellows\u27 current use of online and social media tools, assess the value of online learning, and identify the educational content preferred by ID fellows. We subsequently convened focus groups with ID fellows to explore how digital tools contribute to fellow learning. RESULTS: A total of 110 ID fellows responded to the survey. Over half were second-year fellows (61, 55%). Although many respondents were satisfied with the educational resources provided by their fellowship program (70, 64%), the majority were interested in an online collaborative educational resource (97, 88%). Twitter was the most popular social media platform for education and the most valued online resource for learning. Focus groups identified several themes regarding social medial learning: broadened community, low barrier to learning, technology-enhanced learning, and limitations of current tools. Overall, the focus groups suggest that fellows value social media and online learning. CONCLUSIONS: ID fellows are currently using online and social media resources, which they view as valuable educational tools. Fellowship programs should consider these resources as complementary to traditional teaching and as a means to augment ID fellow education

Spectral Analysis of Multi-dimensional Self-similar Markov Processes

In this paper we consider a discrete scale invariant (DSI) process $\{X(t), t\in {\bf R^+}\}$ with scale $l>1$. We consider to have some fix number of observations in every scale, say $T$, and to get our samples at discrete points $\alpha^k, k\in {\bf W}$ where $\alpha$ is obtained by the equality $l=\alpha^T$ and ${\bf W}=\{0, 1,...\}$. So we provide a discrete time scale invariant (DT-SI) process $X(\cdot)$ with parameter space $\{\alpha^k, k\in {\bf W}\}$. We find the spectral representation of the covariance function of such DT-SI process. By providing harmonic like representation of multi-dimensional self-similar processes, spectral density function of them are presented. We assume that the process $\{X(t), t\in {\bf R^+}\}$ is also Markov in the wide sense and provide a discrete time scale invariant Markov (DT-SIM) process with the above scheme of sampling. We present an example of DT-SIM process, simple Brownian motion, by the above sampling scheme and verify our results. Finally we find the spectral density matrix of such DT-SIM process and show that its associated $T$-dimensional self-similar Markov process is fully specified by $\{R_{j}^H(1),R_{j}^H(0),j=0, 1,..., T-1\}$ where $R_j^H(\tau)$ is the covariance function of $j$th and $(j+\tau)$th observations of the process.Comment: 16 page