Modelling Construction Dust Safety Distance

2014 ◽  
Vol 1065-1069 ◽  
pp. 1704-1709
Author(s):  
Min Wu ◽  
Wai Ching Tang ◽  
Guang Wei Chen ◽  
Shuo Chen ◽  
Zhi Dan Qin ◽  
...  
Keyword(s):  
Drill Hole ◽  
Construction Workers ◽  
Pneumatic Drill ◽  
Construction Process ◽  
Construction Sites ◽  
Protective Measures ◽  
Safety Distance ◽  
Simulation Results ◽  
Dust Distribution ◽  
Drill Holes

Construction dust may lead to Silicosis, a disabling respiratory disease which severely threatens the life of construction workers. Therefore, it is important to predict and determine the safety area of dust generated by the construction process and the corresponding protective measures that must be adopted. In this paper, based on real site data, we modelled and simulated the pneumatic drill holes in rock drilling processes to analyze the dust distribution on construction sites. Our simulation results show that the dangerous distance from the pneumatic drill hole is 3.5m. Within the dangerous distance, the dust concentration ranged from 0.039 mg/m3to30mg/m3, and decreased as distance increases. Within the dangerous distance, dust alleviation technologies are strongly recommended and appropriate protective measures must be adopted by construction workers.

PATTERNS OF GASTROPOD MOLLUSK PREDATION ON BIVALVE MOLLUSKS ALONG THE UPPER TEXAS GULF COAST

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Serena J. Randolph ◽  
Alan D. Maccarone
Keyword(s):  
Shell Thickness ◽  
Prey Species ◽  
Gulf Coast ◽  
Prey Selection ◽  
Drill Hole ◽  
The United States ◽  
Hole Diameter ◽  
Bivalve Mollusks ◽  
Collection Site ◽  
Drill Holes

Abstract Predation on bivalve mollusks by gastropod mollusks is common in coastal regions of the United States; however, few previous studies have examined whether drilling gastropods exhibit prey selection. In 2016, shells with small holes drilled by as many as two gastropod predators were collected at three sites separated by 30 km along the Texas Upper Gulf Coast on the Bolivar Peninsula (29° 40′N, 94° 90′W). The likeliest predators in these waters are the southern oyster drill (Stramonita haemastoma Linnaeus 1767) and the moon snail (Neverita duplicate Say 1822). Collected shells were identified to species and measurements were taken to examine statistical relationships between predators and prey species. These measurements included drill-hole diameter, shell thickness, drill-hole completeness, number of drill attempts, and collection site. Across the three locations, 17 different species of shells with drill holes were collected; of these, we focused on the ten most abundant species (n = 277 shells). The sample showed high variation in drill-hole diameter, shell thickness, and drill-hole completeness. Both the total number of holes and mean drill-hole diameter differed significantly among prey species (ANOVA, both P < 0.0001). In addition, drill-hole diameter correlated directly with prey shell thickness (P < 0.0001). Shells whose drill holes were complete were significantly thinner than shells with incomplete holes (P < 0.0001). Mean prey shell thickness, mean drill-hole diameter, and mean number of drill holes all differed significantly by collection site (all P < 0.0001). Ecological and morphological implications related to gastropod predation on mollusks are discussed.

scholarly journals Risk Perception in the Construction Industry: Differences Between Italian and Migrant Workers Before and After a Targeted Training Intervention

2021 ◽  
Vol 31 (1) ◽  
pp. 65-71
Author(s):  
Federico Ricci ◽  
Giulia Bravo ◽  
Alberto Modenese ◽  
Fabrizio De Pasquale ◽  
Davide Ferrari ◽  
...  
Keyword(s):  
Risk Perception ◽  
Construction Industry ◽  
Migrant Workers ◽  
Construction Workers ◽  
Construction Sites ◽  
Visual Tool ◽  
Occupational Risks ◽  
Linguistic Barriers ◽  
Before And After ◽  
The Difference

We developed a visual tool to assess risk perception for a sample of male construction workers (forty Italian and twenty-eight immigrant workers), just before and after a sixteen-hour training course. The questionnaire included photographs of real construction sites, and workers were instructed to select pictograms representing the occupational risks present in each photograph. Points were awarded for correctly identifying any risks that were present, and points were deducted for failing to identify risks that were present or identifying risks that were not present. We found: (1) Before the course, risk perception was significantly lower in immigrants compared to Italians ( p < .001); (2) risk perception improved significantly ( p < .001) among all workers tested; and (3) after the training, the difference in risk perception between Italians and immigrants was no longer statistically significant ( p = .1086). Although the sample size was relatively small, the results suggest that the training is effective and may reduce the degree to which cultural and linguistic barriers hinder risk perception. Moreover, the use of images and pictograms instead of words to evaluate risk perception could also be applied to nonconstruction workplaces.

scholarly journals Exploring the Relationship between Safety Climate and Worker Safety Behavior on Building Construction Sites in Taiwan

2021 ◽  
Vol 13 (6) ◽  
pp. 3326
Author(s):  
Wei Tong Chen ◽  
Hew Cameron Merrett ◽  
Ying-Hua Huang ◽  
Theresia Avila Bria ◽  
Ying-Hsiu Lin
Keyword(s):  
Safety Climate ◽  
Organizational Factors ◽  
Safety Training ◽  
Building Construction ◽  
Construction Workers ◽  
Occupational Accidents ◽  
Successful Implementation ◽  
Construction Sites ◽  
Safety Behavior ◽  
The Relationship

Construction occupational accidents are often attributed to workers’ having an insufficient perception of how their actions influence safety in the construction site. This research explores the relationship between safety climate (SC) and personnel safety behavior (SB) of construction workers operating on building construction sites in Taiwan. The study discovered a significant positive relationship between SC and SB of Taiwan’s building construction sites, and in turn SC level had a positive impact on SB participation and overall safety perceptions. The higher the SC cognition of Taiwan’s building construction workers, the better the performance of SB was found to be. The dimension of "safety commitment and safety training" had the greatest relationship with SB. Safety training also had a deep impact on the cognition of SB. Therefore, the organizational culture and attitudes to safety coupled with the successful implementation of safety education and training can effectively enhance SC and worker SB on building construction sites in Taiwan, thereby potentially reducing the impacts of the underlying organizational factors behind safety related incidents.

scholarly journals CO2 Emission Due to Excavation

2019 ◽  
Vol 8 (2S8) ◽  
pp. 951-953
Keyword(s):  
Greenhouse Gases ◽  
Construction Process ◽  
Construction Sites ◽  
Rapid Urbanization ◽  
Flat Base ◽  
Prime Concern ◽  
Significant Area ◽  
Carbon Dioxide Co2 ◽  
Environmental Outcome ◽  
Emission Of Greenhouse Gases

Rapid urbanization in developing countries causes the emission of greenhouse gases. A major part of emission is released by infrastructure construction sites. construction process involves excavation, (which is a significant area of study, given that it involves changing the site by disturbing and removing vegetation. The main gases which are associated with excavation include carbon dioxide(CO2), methane(CH4) and nitrous oxide(N2O). These gases (greenhouse gases) are responsible for global warming. Nearly about 22.6% emission of co2 is due to earthwork on the construction site. Although excavation is economical in terms of delivering a flat base for raft construction, the environmental outcome of this approach needs to be examined more carefully in terms of influencing the environment. The air quality in India according to a WHO one of the polluted country in the world. In this situation, controlling and reducing pollution is an area of prime concern

scholarly journals Analysis of suspension bridge tunnel-type anchorage construction on the stability of surrounding rock

2020 ◽  
Vol 198 ◽  
pp. 02006
Author(s):  
Nana Li ◽  
Yongqiang Zhou ◽  
Yanqiang Zhao ◽  
Guiju Li
Keyword(s):  
Suspension Bridge ◽  
Surrounding Rock ◽  
Construction Process ◽  
Analysis Model ◽  
Stability Of Surrounding Rock ◽  
Numerical Software ◽  
Left And Right ◽  
Simulation Results ◽  
The Stability ◽  
The Right

In order to study the interaction between the left and right tunnels of suspension bridge tunnel-type anchorage, the finite difference numerical software is used to analyze the mechanical properties of the surrounding rock during the construction process. A numerical analysis model based on FLAC3D is established to analyze the stress, displacement and plastic zone changes of the surrounding rock of right tunnel anchor cavern during the construction of left tunnel anchor cavern. The right tunnel anchor cavern is excavated firstly, and then the left tunnel anchor cavern is excavated. The numerical simulation results show that the main displacement of the right tunnel occurs in the construction stage of the anchor plug body and the rear anchor cavern of the left tunnel. During the excavation of the left tunnel, the plastic zones of the left and right tunnel anchor caverns are only connected above the middle of the waist wall. Therefore, it is suggested that during the construction process, especially in the excavation stage of the anchor plug body and the rear anchor cavern, the area above the middle of the tunnel waist wall should be strengthened in time to ensure the construction safety.

Large Drill Holes Are Still Present in the Long Term After Arthroscopic Bankart Repair With Absorbable Tacks: An 18-Year Randomized Prospective Study

2020 ◽  
Vol 48 (8) ◽  
pp. 1865-1872
Author(s):  
Christina Chrysanthou Constantinou ◽  
Ninni Sernert ◽  
Lars Rostgård-Christensen ◽  
Jüri Kartus
Keyword(s):  
Study Groups ◽  
Drill Hole ◽  
Ct Images ◽  
Bankart Repair ◽  
Plain Radiographs ◽  
Arthroscopic Bankart Repair ◽  
Absorbable Tacks ◽  
Drill Holes

Background: Studies have demonstrated the development of an osseous reaction at the drill sites of anchors after arthroscopic shoulder surgery. Purpose: To investigate the drill-hole size at 18 years after arthroscopic Bankart repair using either fast polygluconate acid (PGA) or slow polylevolactic acid (PLLA) absorbable tacks and to compare the functional outcomes and development of osteoarthritis. Study design: Randomized controlled trial; Level of evidence, 2. Methods: 40 patients with unidirectional anterior shoulder instability, treated with arthroscopic Bankart repair, were randomized into the PGA group (n = 20) or the PLLA group (n = 20). Plain radiographs of both shoulders, as well as computed tomography (CT) images of the operated shoulder, were used to evaluate the drill-hole size, volume, and degenerative changes. Functional outcomes were assessed by use of the Rowe score, Constant score, and Western Ontario Shoulder Instability (WOSI) index. Results: Of the 40 patients, 32 patients returned for the follow-up (15 PGA and 17 PLLA). No significant differences were found in the population characteristics between the study groups. The mean follow-up time was 18 years for both groups. No significant differences were seen in range of motion, strength in abduction, or Constant, Rowe, and WOSI scores between the groups. Recurrence rate was 33% in the PGA group and 6% in the PLLA group during the follow-up period ( P = .07). The drill-hole appearance on plain radiographs (invisible/hardly visible/visible/cystic) was 11/2/2/0 and 6/5/5/1 for the PGA and PLLA groups, respectively ( P = .036). The mean ± SD drill-hole volume as estimated on CT images was 89 ± 94 and 184 ± 158 mm3 in the PGA and PLLA groups, respectively ( P = .051). Degenerative changes (normal/minor/moderate/severe) on plain radiographs were 7/4/4/0 and 3/8/5/1 for the PGA and PLLA groups, respectively ( P = .21), and on CT images were 5/7/3/0 and 2/6/6/3 for the PGA and PLLA groups, respectively ( P = .030). Conclusion: This long-term follow-up study demonstrated that the PLLA group had significantly more visible drill holes than the PGA group on plain radiographs. However, this difference was not evident on CT imaging, with both groups having several visible cystic drill holes and a substantial drill-hole volume defect. No significant differences were found between the study groups in terms of clinical outcomes.

Construction Productivity Factors Affected by the Motivation of Foreign Laborers in Construction Fields

2013 ◽  
Vol 357-360 ◽  
pp. 2599-2602 ◽  
Author(s):  
Yoon Seok Shin ◽  
Jin Dong Kim ◽  
Tae Yong Kim ◽  
Gwang Hee Kim
Keyword(s):  
Social Factors ◽  
Psychological Factors ◽  
East Asian ◽  
Motivational Factors ◽  
Construction Workers ◽  
Foreign Workers ◽  
Economic Factors ◽  
Construction Sites ◽  
Construction Productivity ◽  
Construction Companies

These days, it is necessary to introduce motivational methods for foreign workers on construction sites in order to improve the productivity of Korean construction companies. Therefore, this study aimed to compare the motivational factors of East Asian laborers working on Korean construction fields in order to better understand the characteristics of foreign laborers. Of the motivational factors, economic factors among were considered more important than social and psychological factors for East Asian construction workers. And the importance averages of the construction workers from three ethnic groups were found to be statistically equal in terms of economic and social factors, but were not for psychological factors.

Investigation of Drill Hole Quality of Multi-Layer PWBs for High Current Capacity

2007 ◽  
Author(s):  
Eiichi Aoyama ◽  
Toshiki Hirogaki ◽  
Keiji Ogawa ◽  
Kenichi Mori ◽  
Yuusuke Itagaki
Keyword(s):  
Copper Foil ◽  
Drill Hole ◽  
Foil Thickness ◽  
Electronic Systems ◽  
Hole Quality ◽  
Large Current ◽  
Drill Holes ◽  
Objective Variable ◽  
Chip Load ◽  
Through Hole

Recently, as a result of changes in the automotive industry, a large number of electronic systems have been installed in cars. The thickness of the copper foil used for printed wiring boards (PWBs) has tended to increase in response to the large current capacity required for such electronic equipment. Therefore, the nail head generated in the inner layer copper foil was examined with respect to the influence of the thickness of the copper foil on the through-hole quality. In the present study, the size of the nail head generated in the copper foil after drilling a through hole was used as the objective variable. The explaining variables included drill wear, frequency, feed rate, chip load, drill temperature, copper foil thickness, copper foil cutting distance, and number of drill holes. We investigated the relationships between these explaining variables and the objective variable and found that the copper foil cutting distance was a very important parameter in generating nail heads. In addition, we found that the chip load is important for controlling nail head generation.

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