Optimisation of one stage electrostatic precipitator for welding fume filtration

AbstractIn addition to huge installations of electrostatic precipitators (ESP), as those employed for dust filtration in blast furnaces and cement factories, there are also small devices as the ones used for fume filtration in welding shops. The aim of this paper is to optimize the geometric characteristics and the electric operating conditions of a “one-stage” precipitator intended for the filtration of welding fumes. The experimental bench is composed of 2 units, each consisting in an horizontal wire (tungsten, diameter 0.1 mm), energized from a high-voltage supply (+15 kV, 5 mA), and equally distant from two vertical plate electrodes (aluminium, length 200 mm × variable width) connected to the ground. Two “one-factor-at-a-time” experiments paved the way for a composite experimental design that enabled the optimization of ESP geometry, i.e. the inter-electrode interval and width of the collecting electrodes

Rejection of human intestinal allografts: Alone or in combination with the liver

The current results of the present series demonstrate that intestinal allografts are more vulnerable to rejection and continue to be at a significantly higher risk long after transplantation compared with isolated liver allograft recipients. Unexpectedly, a combined liver allograft does not protect small bowel from rejection. The necessarily continuous heavy immunosuppression for these unique recipients is potentially self-defeating. This is clearly demonstrated by their high susceptibility to early and late infectious complications after transplantation as reported in this issue. With the minimal graft-versus-host disease threat in this clinical trial, our revised protocol for future intestinal transplantation is to maximize the passenger leukocyte traffic with supplementary bone marrow from the same intestinal donor in an attempt to augment the development of systemic chimerism and the gradual induction of donor-specific nonreactivity

Coverage and Energy Analysis of Mobile Sensor Nodes in Obstructed Noisy Indoor Environment: A Voronoi Approach

The rapid deployment of wireless sensor network (WSN) poses the challenge of finding optimal locations for the network nodes, especially so in (i) unknown and (ii) obstacle-rich environments. This paper addresses this challenge with BISON (Bio-Inspired Self-Organizing Network), a variant of the Voronoi algorithm. In line with the scenario challenges, BISON nodes are restricted to (i) locally sensed as well as (ii) noisy information on the basis of which they move, avoid obstacles and connect with neighboring nodes. Performance is measured as (i) the percentage of area covered, (ii) the total distance traveled by the nodes, (iii) the cumulative energy consumption and (iv) the uniformity of nodes distribution. Obstacle constellations and noise levels are studied systematically and a collision-free recovery strategy for failing nodes is proposed. Results obtained from extensive simulations show the algorithm outperforming previously reported approaches in both, convergence speed, as well as deployment cost.Comment: 17 pages, 24 figures, 1 tabl

Research and Development Aspects on Chemical Preparation Techniques of Photoanodes for Dye Sensitized Solar Cells

The importance of dye sensitized solar cells (DSSCs) as a low-cost and environmentally friendly photovoltaic (PV) technology has prompted many researchers to improve its efficiency and durability. The realization of these goals is impossible without taking into account the importance of the materials in DSSCs, so the focus on the preparation/deposition methods is essential. These methods can be either chemical or physical. In this study, the chemical applied methods that utilize chemical reaction to synthesize and deposit the materials are covered and categorized according to their gas phase and liquid phase precursors. Film processing techniques that can be used to enhance the materials' properties postpreparation are also included for further evaluation in this study. However, there is a variety of consideration, and certain criteria must be taken into account when selecting a specific deposition method, due to the fact that the fabrication conditions vary and are unoptimized

Dielectric and conductivity relaxation in mixtures of glycerol with LiCl

We report a thorough dielectric characterization of the alpha relaxation of glass forming glycerol with varying additions of LiCl. Nine salt concentrations from 0.1 - 20 mol% are investigated in a frequency range of 20 Hz - 3 GHz and analyzed in the dielectric loss and modulus representation. Information on the dc conductivity, the dielectric relaxation time (from the loss) and the conductivity relaxation time (from the modulus) is provided. Overall, with increasing ion concentration, a transition from reorientationally to translationally dominated behavior is observed and the translational ion dynamics and the dipolar reorientational dynamics become successively coupled. This gives rise to the prospect that by adding ions to dipolar glass formers, dielectric spectroscopy may directly couple to the translational degrees of freedom determining the glass transition, even in frequency regimes where usually strong decoupling is observed.Comment: 8 pages, 7 figure

Assessment of Water Quality of East Hammar Marsh Using Water Quality Index (WQI) Following the Cessation of Saline Tide in 2018

The water quality index (WQI) was studied monthly, from November 2018 to October 2019, at three stations (Al-Saddah, Al-Burgah, & Al-Marsa) in the Basrah Governorate's East Hammar Marsh. This study measured various environmental factors, including water temperature, pH, dissolved oxygen, biological oxygen demand, light penetration, salinity, total dissolved salts, total hardness, nitrates, nitrites, phosphate, sulfate, calcium, and magnesium. After the end of the salty tide in 2018, the first station showed poor seasonal evidence 43.7 (low WQI score) in the winter, fair 67.6 and 64.9 (third category) in the spring and summer respectively, and marginal 55.9 (fourth category) in the summer and fall. The second and third stations had poor WQI score in the Winter and marginal in the rest of the seasons. The results indicate that the water quality is polluted and deviates from its optimal state. The WQI values varied significantly across all sites. The lack of freshwater drainage and ongoing marine water impacts are the reasons for the deterioration of water quality. Treatment is recommended to address this issue

Novel EEG sensor-based risk framework for the detection of insider threats in safety critical industrial infrastructure

The loss or compromise of any safety critical industrial infrastructure can seriously impact the confidentiality, integrity, or delivery of essential services. Research has shown that such threats often come from malicious insiders. To this end, survey- and electrocardiogram-based approaches were suggested to identify these insiders; however, these approaches cannot effectively detect or predict any malicious insiders. Recently, electroencephalograms (EEGs) have been suggested as a potential alternative to detect these potential threats. Threat detection using EEG would be highly reliable as it overcomes the limitations of the previous methods. This study proposes a proof of concept for a system wherein a model trained using a deep learning algorithm is employed to evaluate EEG signals to detect insider threats; this algorithm can classify different mental states based on four category risk matrices. In particular, it analyses brainwave signals using long short-term memory (LSTM) designed to remember previous mental states of each insider and compare them with the current brain state for associated risk-level classification. To evaluate the performance of the proposed system, we perform a comparative analysis using logistic regression (LR)—a predictive analysis used to describe the relationship between one dependent binary variable and one or more independent variables—on the same dataset. The experiment results suggest that LSTM can achieve a classification accuracy of more than 80% compared to LR, which yields a classification accuracy of approximately 51%

An introduction to video methods in organizational research

Video has become a methodological tool of choice for many researchers in social science, but video methods are relatively new to the field of organization studies. This article is an introduction to video methods. First, we situate video methods relative to other kinds of research, suggesting that video recordings and analyses can be used to replace or supplement other approaches, not only observational studies but also retrospective methods such as interviews and surveys. Second, we describe and discuss various features of video data in relation to ontological assumptions that researchers may bring to their research design. Video involves both opportunities and pitfalls for researchers, who ought to use video methods in ways that are consistent with their assumptions about the world and human activity. Third, we take a critical look at video methods by reporting progress that has been made while acknowledging gaps and work that remains to be done. Our critical considerations point repeatedly at articles in this special issue, which represent recent and important advances in video method