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A dust cloud is formed by a high-pressure air blast in dust explosion experiments in the spherical 20 L chamber. The state of the dust cloud has a significant impact on the dust explosion. However, it is difficult to observe the dust distribution in the chamber during the dust dispersion. Numerical simulation was used to examine the dust distribution in the chamber with the rebound nozzle in this work. The paper aims to discuss these issues.

Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed.

Dust in the spherical 20 L chamber is in the state of very intensifying motion within 30 ms from dispersion starting. Dust in the chamber reaches a uniform state beyond 200 ms. The pressure for dust dispersion should be higher than 0.5 MPa for the aluminum dusts of larger than 50. The higher blast pressure is not always applicable to achieve a uniform dispersion. There is a best blast pressure value for a given dust to achieve a uniform dispersion in the spherical 20 L chamber.

Dust cloud generation is essential for understanding dust explosions. Dust cloud deflagration parameters depend on the uniformity and concentration of dusts dispersed by a high-pressure air blast. Numerical simulation was used to examine the multiphase flow of the dust air mixture in this work. Through a series numerical simulations, the influences of the dust particle size and the pressure for dust dispersion on the have been analyzed, and the results are discussed. The data are useful for understanding the basics of dust cloud formation.

The data are useful for evaluating dust explosion experimental parameters.

Dispersible uniformity has a strong impact on measured parameters of dust explosion in a chamber. However, it is difficult to observe the dust particles distribution during the dispersion. Numerical simulation was used to examine the dust particles distribution and its influencing factors during the dispersion in this work. New finding is: the approach to examine the distribution of dust particles dispersed by a high-pressure blast in a chamber; the variation of dispersible uniformity and its influencing factors when dust is injected into the spherical 20 L chamber by high-pressure air blast.

The stone dust column was used to strengthen the sample and had a significant effect on improving the shear strength of the kaolin clay. The application of stone columns, which can improve the overall carrying capacity of soft clay as well as lessen the settlement of buildings built on it, is among the most widespread ground improvement techniques throughout the globe. The performance of foundation beds is enhanced by their stiffness values and higher strength, which could withstand more of the load applied. Stone dust is a wonderful source containing micronutrients for soil, particularly those derived from basalt, volcanic rock, granite and other related rocks. The aim of this paper is to evaluate the properties of soft clay reinforced with encapsulated stone dust columns to remediate problematic soil and obtain a more affordable and environmentally friendly way than using other materials.

In this study, the treated kaolin sample's shear strength was measured using the unconfined compression test (UCT). 28 batches of soil samples total, 12 batches of single stone dust columns measuring 10 mm in diameter and 12 batches of single stone dust columns measuring 16 mm in diameter. Four batches of control samples are also included. At heights of 60 mm, 80 mm and 100 mm, respectively, various stone dust column diameters were assessed. The real soil sample has a diameter of 50 mm and a height of 100 mm.

Test results show when kaolin is implanted with a single encased stone dust column that has an area replacement ratio of 10.24% and penetration ratios of 0.6, 0.8 and 1.0, the shear strength increase is 51.75%, 74.5% and 49.20%. The equivalent shear strength increases are 48.50%, 68.50% and 43.50% for soft soil treated with a 12.00% area replacement ratio and 0.6, 0.8 and 1.0 penetration ratios.

This study shows a comparison of how sample types affect shear strength. Also, this article provides argumentation behind the variation of soil strength obtained from different test types and gives recommendations for appropriate test methods for soft soil.

The occupational health risk associated with the production of prefabricated concrete components is often overlooked. This paper will use a damage assessment and cyclic mitigation (DACM) model to provide individualized exposure risk assessment and corresponding mitigation management measures for workers who are being exposed.

The DACM model is proposed based on the concept of life cycle assessment (LCA). The model uses Monte-Carlo simulation for uncertainty risk assessment, followed by quantitative damage assessment using disability-adjusted life year (DALY). Lastly, sensitivity analysis is used to identify the parameters with the greatest impact on health risks.

The results show that the dust concentration is centered around the mean, and the fitting results are close to normal distribution, so the mean value can be used to carry out the calculation of risk. However, calculations using the DACM model revealed that there are still some work areas at risk. DALY damage is most severe in concrete production area. Meanwhile, the inhalation rate (IR), exposure duration (ED), exposure frequency (EF) and average exposure time (AT) showed greater impacts based on the sensitivity analysis.

Based on the comparison, the DACM model can determine that the potential occupational health risk of prefabricated concrete component (PC) factory and the risk is less than that of on-site construction. It synthesizes field research and simulation to form the entire assessment process into a case-base system with the depth of the cycle, which allows the model to be continuously adjusted to reduce the occupational health damage caused by production pollution exposure.

The effects of dust exposure in buildings and its health and comfort consequences continue to concern occupants, particularly those who spend most of their time indoors. This study examines the influence of building opening characteristics on surface dust loading in indoor environments to determine the dust particles' impact on different opening configurations.

Indoor Harmattan dust surface loading data were collected from Maiduguri, Northeastern Nigeria, using model rooms with six different window configurations. A simple mathematical relationship was employed to assess surface dust loading characteristics in the model rooms. The study measured dust thrice between December and February for three days (72 h). The results were analyzed using descriptive statistics.

The results determined the highest average surface dust loading of 12.03 g/m2 in the room with awning windows at an indoor-to-outdoor (I/O) ratio of 0.7. In contrast, the experiment in the room with a closed window recorded the lowest average surface dust loading of 5.24 g/m2 at an I/O ratio of 0.30, which is infiltration. The outcomes further indicate that the average surface dust loading varies with the building opening type and position, as higher surface dust loadings were recorded in locations closer to the openings (doors and windows), reaffirming that the dominant source of the dust particles is outdoors. According to the study, dust incursion due to infiltration accounts for 30% of the outdoor surface loading.

Thus, Harmattan dust is a serious challenge to the health, productivity and hygiene of building occupants in the study area. The built-environment professionals must use the study's outcome to optimize building openings' designs (shape, size and form) for effective indoor dust control.

Automated dust monitoring in workplaces helps provide timely alerts to over-exposed workers and effective mitigation measures for proactive dust control. However, the cluttered nature of construction sites poses a practical challenge to obtain enough high-quality images in the real world. The study aims to establish a framework that overcomes the challenges of lacking sufficient imagery data (“data-hungry problem”) for training computer vision algorithms to monitor construction dust.

This study develops a synthetic image generation method that incorporates virtual environments of construction dust for producing training samples. Three state-of-the-art object detection algorithms, including Faster-RCNN, you only look once (YOLO) and single shot detection (SSD), are trained using solely synthetic images. Finally, this research provides a comparative analysis of object detection algorithms for real-world dust monitoring regarding the accuracy and computational efficiency.

This study creates a construction dust emission (CDE) dataset consisting of 3,860 synthetic dust images as the training dataset and 1,015 real-world images as the testing dataset. The YOLO-v3 model achieves the best performance with a 0.93 F1 score and 31.44 fps among all three object detection models. The experimental results indicate that training dust detection algorithms with only synthetic images can achieve acceptable performance on real-world images.

This study provides insights into two questions: (1) how synthetic images could help train dust detection models to overcome data-hungry problems and (2) how well state-of-the-art deep learning algorithms can detect nonrigid construction dust.

January 15, 1973 Ironfoundry — Statutory duty — Breach — Noxious dust — Prolonged inhalation of noxious dust — Chronic lung illness — Employers' actual or constructive knowledge of health hazard — Test to apply when determining constructive knowledge — Whether employer should be aware of recent medical or scientific knowledge — Factories Act, 1961 (9 & 10 Eliz.II, c.34), ss.4(l), 63(1).

The removal of Ismative SHR blue (reactive dye) using a very cheap cement factory waste called by‐pass kiln dust has been investigated in batch mode. The effects of initial dye solution concentration, particle size, agitation rate, amount of by‐pass kiln dust, and dye solution temperature were studied. A 95.5 per cent removal was achieved. Some pretreatment of by‐pass kiln dust, such as washing by distilled water or rinsing with HCL solution, has been done. By using the washed by‐pass kiln dust the values of total dissolved solids, alkalinity, and efficiency of colour removal were reduced. A very rapid irreversible chemical reaction may occur in addition to the adsorption process. Ferric chloride was used as a coagulant after settling to complete the separation of the dust from the clear solution. A removal of 96 per cent from the initial colour of the industrial coloured wastewater was achieved.

To introduce a research carried out in a real world for implementing a dust control system (DCS) for controlling the indoor air quality (IAP) on the production floor of one of the major electronics company in Malaysia.

The paper is arranged as follows, a brief description of the significant of DCS in electronic industry and brief introduction to the electronic company as a case study company for introducing the DCS. The discussion on the characteristics management and planning tools (MPTs) that have been adopted as the analysing tools for assisting in the decision‐making process in identifying the problems and improvement strategies. It follows by the detail analysis phase regarding the implementation process that it as backbone for introducing the DCS. Finally a discussion about the result obtained from the MPT analysis on the techniques for identifying the root causes of the dust pollution problem as well as the best improvement strategies that can be adopted by the case study company.

Three analysis techniques from MPT have been used; there are relation diagram, tree diagram and prioritization matrices analyses. These techniques are very powerful for analysing the specific problem using verbal data. The outputs (results) from these techniques have been used as the solutions to the dust pollution problem. As a result, the implementations of DCS successfully reduce the dust level and stabilise the dust distribution on the production floor.

This paper offer a systematic way in identifying and controlling the IAP in industry.

This paper introduces very useful methods in decision making for identifying the solutions for environmental problem and implementation of DCS in a real world environment.

The purpose of this paper is to investigate the psychosocial perception of harmattan dust on building openings, health and housekeeping to determine the influence of the dust on building occupants.

Population-representative survey data were collected from Maiduguri, Northeastern Nigeria, through physical administration of questionnaires by assessing several variables. Statistical package SPSS 16.0 was used for the data analysis, which is mainly descriptive analysis in frequencies, percentages and means together with a repeated Pearson’s chi-square analysis to identify the relationship between the factors and the significance testing.

The results show that majority (94.3%) experienced dust problem in harmattan season, and a larger part (76.6%) confirmed that the dust penetrates through doors and windows. Higher percentage (91.2%) noticed that the dust particles on their floor/furniture surfaces, and on an average, people clean their houses three times daily in harmattan season. Majority (80.5%) of the respondents smell dust in the harmattan season, and greater part (77.9%) experienced health challenges in this season, of which 12.8% confirmed harmattan dust aggravates their asthma, 13.6% confirmed it causes headache, 3.1% confirmed it exacerbated pneumonia, 58.5% confirmed it causes coughing, 3.5% confirmed catarrh, 2.3% confirmed nasal/respiratory congestion, sneezing and bronchitis and 6.2% experienced eye problems. Moreover, the results indicate that number/types of openings in a building are significantly associated with factors including smelling dust in the harmattan season and health problem experienced because of dust indoors. The number of times people clean their homes/workplaces is significantly related to important variables such as experiencing dust problem in harmattan season and number/type of openings in a building. The results further established that the health problem experienced by people is significantly related to important variables including dust problem experienced in the harmattan season and type of openings in a room.

Harmattan dust is a serious challenge to health and well-being of building occupants in the study area. The built environment professionals need to optimize building openings for effective dust control indoors.

The Secretary of State in exercise of powers conferred by sections 139(1) and 180(3) of the Factories Act 1961 and now vested in him and of all other powers enabling him in that behalf, hereby makes the following Order:—