Cabin Area Research Articles

Vibration optimization methods of dredger engine room

Abstract Due to the large number and heavy weight of equipment, as well as the high center of gravity in the cabin area of dredgers, the concentrated arrangement of equipment is prone to local vibration problems in the cabin area. Additionally, there are many devices that need to be placed under the deck in the cabin area, which imposes significant constraints on the placement of supports. Using the finite element method to analyze the vibration problem of a certain dredger, we studied the influence of different equipment arrangements and structural reinforcement methods on vibration. This allowed us to summarize the characteristics of vibration under different improvement methods, providing feasible solutions for improving the vibration problem in the cabin area of dredgers. After adjusting the equipment layout and reinforcing local structures, the vibration in the dredger’s cabin area ultimately meets the design requirements satisfactorily.

Occupational Exposure of On-Shift Ottawa Firefighters to Flame Retardants and Polycyclic Aromatic Hydrocarbons.

Firefighters can be exposed to complex mixtures of airborne substances, including hazardous substances released during structural fires. This study employed silicone wristbands (SWBs) as passive samplers to investigate potential exposure to polycyclic aromatic hydrocarbons (PAHs) and flame retardants (FRs). SWBs were deployed at different areas of four fire stations, in four truck cabins, and at an office control location; they were also donned outside the jackets of 18 firefighters who responded to fire calls. Overall, office areas had significantly lower PAHs than fire station areas. Vehicle bays and truck cabins had significantly higher concentrations of low molecular weight (LMW) PAHs than sleeping and living room areas. For organophosphate ester flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(1-chloro-2-propyl) phosphate (TCPP) were detected in all the samples; 2-ethylhexyl diphenyl phosphate (EHDPP) was more frequently detected in the fire station areas. Triphenyl phosphate (TPP) concentrations were highest in the truck cabin and office areas, and tris(1,3-dichloro-2-propyl)phosphate (TDCPP) was highest in truck cabins. Thirteen of 16 PAHs and nine of 36 OPFRs were detected in all the SWBs worn by firefighters, and tris (2-butoxyethyl) phosphate (TBEP) was the predominant OPFR. Levels of LMW PAHs were significantly lower when firefighters did not enter the fire. LMW PAHs, HMW (high molecular weight) PAHs, and EHDPP were significantly elevated when heavy smoke was reported. This work highlights the potential for occupational exposure to PAHs and flame retardants in some fire station areas; moreover, factors that may influence exposure during fire suppression. Whilst firefighters' occupational exposure to PAHs is likely related to fire suppression and exposure to contaminated gear and trucks, exposure to OPFRs may be more related to their presence in truck interiors and electronics.

Walking-induced particle resuspension in a commercial airliner cabin under different ventilation systems

The potential health risk posed by particle resuspension in the air of an airliner cabin is a concern for passengers. This study employed computational fluid dynamics (CFD) to analyze particle dispersion patterns under different ventilation systems, such as mixing ventilation (MV), underfloor air distribution (UFAD), and aisle displacement ventilation (ADV), within a twin-aisle cabin environment. To ensure the accuracy of the CFD model, the study validated the simulated air velocity distribution against experimental airflow patterns from a small-scale water model reported in existing literature. Additionally, the research included direct measurements of particle resuspension within the breathing zone of a full-scale, twin-aisle cabin mockup, which featured five rows of seats. These measurements were taken in response to the disturbance caused by a volunteer walking over an aviation carpet in the aisle. While the CFD simulation results generally aligned with the experimental data, some discrepancies were noted. Pinpointing the exact causes of these discrepancies proved challenging due to the numerous uncertainties and approximations inherent in the study. Nevertheless, the investigation revealed that the air in the upper region near the moving body was pushed forward, creating a strong airflow that enveloped the body. This dynamic resulted in the formation of a wake that lifted particles from the floor level to the upper cabin area. The study observed that particle concentration within the breathing zone increased in the direction of movement. The airflow patterns produced by the three ventilation systems were different. Despite the cabin's symmetrical design, some particles can still transfer from one side to the other, especially under the MV system. The peak particle concentration in the breathing zone was recorded at 20 s, after which it decreased to negligible levels by 120 s. Among the ventilation systems analyzed, the MV system exhibited the highest peak particle concentration, while the UFAD system showed the lowest peak. However, the UFAD system also presented the possibility of very high particle concentrations at certain seats.

Hopeful, but Worried for the Future: An Analysis of the Lived Consequences of Colonisation as Narrated by Older South Sámi in Norway

Various forms of colonisation and discrimination processes are unfortunately common to Indigenous Peoples worldwide. In this article, the focus is the lived consequences of colonisation in the Norwegian part of Sápmi (the Sámi traditional lands), where systematic state-imposed colonisation officially ended decades ago. Thus, based on a thematic analysis of qualitative in-depth interviews with 12 South Sámi aged 67–84, the aim was to examine how stories about hopes and worries for the future can shed light on how colonisation is experienced among older South Sámi today. The voices of these participants are important, as they can be considered triply muted, due to (a) ageism and (b) continued yet unconscious colonising practices against the Sámi in general and (c) against the South Sámi people in particular, a minority within the minority. Inspired by decolonising perspectives, this article reveals that older South Sámi are worried for the future, not only due to memories from the past but also their experiences with persisting colonial practices such as the ongoing enlargement of windmill parks and cabin areas in the midst of the winter pastures of the South Sámi reindeer herders. Hopefully, the time has come to finally put an end to colonial practices and take collective responsibility for creating a more just future for both coloniser and colonised. Similarly to the participants in this study, the report from the Truth and Reconciliation Commission also stresses issues such as loss of language, experience of racism, and reindeer husbandry being under pressure. This report may therefore be used as an important tool to ameliorate the conditions of the Sámi people if taken into consideration in the time to come.

Enhancing Workplace Efficiency and Security Through Intelligent Employee Surveillance

This project aims to develop an innovative system for accurately tracking employees' working hours based on their presence within designated workspace areas, particularly their work cabins. Leveraging advanced technologies such as image annotation, preprocessing, and augmentation, as well as robust object detection models, this study addresses the need for efficient employee surveillance and time management solutions in contemporary workplaces. The methodology involved detailed annotation and enhancement of image data, enabling precise representation of cabin areas and identification of individual employees within images. Subsequently, a state-of-the-art object detection model, YOLOv8, was utilized to train using this annotated dataset, achieving an impressive accuracy of more than 90% in recognizing and tracking employee presence within the specified cabin regions. Through small incremental changes based on previous insights and optimization, the project achieved high levels of accuracy in inferring employees' working hours based on their occupancy within the designated workspace. By differentiating between time spent inside cabins (considered as working time) and time spent outside these areas (considered as non-working time), the system offers an automated and objective approach to time tracking, eliminating the need for manual input or subjective assessments. Future scopes for this research include exploring the integration of additional sensors or data sources to further enhance the accuracy and granularity of employee activity tracking. Additionally, advancements in machine learning algorithms and hardware may enable real-time processing and analysis of surveillance data, leading to more proactive management of employee productivity and well-being. Moreover, the application of this technology could extend beyond traditional office settings to various industries, such as manufacturing, retail, and healthcare, where precise monitoring of employee activities is crucial for optimizing operations and ensuring compliance with regulations. This research underscores the potential of advanced computer vision techniques, particularly YOLOv8, in revolutionizing employee surveillance and time management practices. By providing real-time monitoring capabilities and ensuring compliance with work regulations, this approach holds promise for enhancing workplace productivity, transparency, and accountability.

Particle number, mass, and surface area concentrations inside an underground metalliferous mine in Kazakhstan

Considerable scientific evidence shows that inhalation of diesel exhaust particles is associated with a wide range of adverse health effects. This study examined the concentrations of diesel particles in five stations of the operational phases of an underground mine in Kazakhstan. Real-time monitoring of particulate number concentration (PNC), lung deposited surface area (LDSA) concentrations, PM1, PM2.5, and PM10 concentrations in the mining operational area, and the breathing zone of the loader driver inside the loader cabin was conducted. The results showed that the highest average PNC and LDSA concentrations were 7 × 105 cm−3 and 4 × 103 μm2 cm−3, respectively, and most of the particles were in the sub-100 nm range. The concentrations level in the loader cabin area (LA), and operational area (OA) of mine was similar with respect to PM1 and PM2.5 as a result of the homogenous distribution of the PM inside the mine's operational phase. The major source of the PM1 and PM2.5 was the diesel engine, while the low LA/OA ratio for PM10 in this study suggested the source of the coarse particles was dust resuspension around the loader cabin.

Spatiotemporal Variations in PM2.5 Concentration in Different Areas of Bus Cabin: A Case Study in Shenzhen, China

Inhalable particulate pollution has adverse effects on human health. Many studies have been conducted to investigate levels and risks of exposure to particulate pollution in public transit, but scant attention has been paid to variations in the pollution levels among different positions inside the cabin. Differences can be observed among different positions inside transit vehicles, like passenger density and activities, which may lead to differentiated exposure risks between different positions. Therefore, this study investigates the level of PM2.5 concentrations and the spatiotemporal variations among three different positions (front, middle, and rear) inside the cabin during bus travel. The three positions represent the three areas inside the bus cabin, i.e., front area (FA), middle area (MA), and rear area (RA). We developed a portable monitoring system for in-cabin measurements, which consists of a mobile device with the designated app, a PM2.5 collecting device, and a temperature-relative humidity monitor. Surveys were carried out on buses of a route in Shenzhen, China, which include inbound and outbound trips during both morning and evening peaks of two working days. Based on spatial and temporal information embedded in data collection devices, PM2.5 concentration data were spatially and temporally referenced. Comparative and descriptive statistical analyses were employed to examine the differences and variations in PM2.5 concentration among the areas inside the bus cabin. There are three major findings. First, for all of the surveyed trips, FA showed the highest and RA showed the lowest PM2.5 concentration. Second, concerning the average pollution level of route segments along the routes, the PM2.5 concentrations in the three cabin areas were higher during inbound trips than during outbound trips. Third, within route segments, PM2.5 concentrations in FA and MA increased rapidly after the bus stopped at stops, and then gradually decreased, while in RA they were relatively stable. In general, a higher level of passenger density increased in-cabin PM2.5 concentration. The findings of our study could provide insight into improving the bus in-cabin microenvironment, such as the seating arrangement for vulnerable passengers.

Research of air-drop mixture particles movement in passenger aircraft cabin

The paper examined the mechanism of propagation and deposition of potentially pathogenic particles in the field of turbulent air flow of the heating and air conditioning system of the closed cabin of a passenger aircraft. In pandemic conditions, when the disease is transmitted from person to person through the air, knowledge and understanding of the patterns of movement of particles of the airborne droplet mixture in a small confined space with a high population density allows assessing the risks of infection and the amount of post-flight processing required, as well as the level of passenger control. Simulation model of air-drop mixture distribution in passenger aircraft cabin is proposed, which is built on the basis of three-dimensional finite-element model of flow motion in non-stationary setting. Two-factor dispersion analysis was carried out to determine the significance of the effect of flight time and cabin area on particle deposition intensity. A regression model of the propagation density of precipitated viral particles of the air drop mixture was constructed and investigated depending on the temperature, ventilation method, layout and number of infected passengers. Based on the results of the studies, temporal and volumetric characteristics of the distribution of particles of the air-drop mixture were obtained, directions and meanings of the mutual influence of the selected main factors of the model on the mechanism of distribution and deposition of potentially pathogenic particles were determined, recommendations were developed on the organization of the process of disinfection measures in the passenger aircraft cabin.

Investigation into Beijing commuters’ exposure to ultrafine particles in four transportation modes: bus, car, bicycle and subway

Traffic-related air pollution contributes considerably to commuters' daily air pollution exposure. Ultrafine particles (UFP) is one of the most commonly measured traffic-related air pollutant during commuting. There are very limited studies on commuting exposure to air pollution in China. To fill the knowledge gap, we conducted the first study that compares commuters' UFP exposure among four modes in a Chinese city. In this study, we measured particle number concentration (PNC) levels of 63 trips in four transportation modes: bus, car, bicycle and subway in 2015 on a typical commuting route between urban and suburban areas in Beijing. We found that buses experienced the highest PNC (geometric mean (SD): 35,066 (10,856) particles cm−3), followed by bicycles (geometric mean (SD): 28,277 (7942) particles cm−3), then cars (geometric mean (SD): 16,302 (5156) particles cm−3), and finally the subway (geometric mean (SD): 13,245 (2936) particles cm−3). Within the subway mode, we detected the highest PNC at station entrances, followed by the transfer tunnel, while cabin areas showed the lowest levels. For the cabin areas of the subway mode, PNC concentrations were higher when the trains were overground than underground. Measures are needed to reduce commuters’ exposures, particularly those traveling by bus and bicycle. Switching the bus transportation system from diesel to cleaner power, such as compressed natural gas or electricity, may help.

The Portable Carbon Monoxide (CO) and Hydrocarbons (HC) Gas Detection System in The Car Cabin Uses The MQ-9 and TGS 2610 Sensors

The increase in the number of vehicles especially cars causes the air environment to look polluted. This is caused by vehicle exhaust gases that can affect the level of human health. Harmful gases such as carbon dioxide (CO) and hydrocarbon (HC) can also enter the car cabin, making people inside feel suffocated and even death. To find out the presence of these gases, a monitoring system prototype is made which is placed in the car cabin. This system consists of input in the form of an MQ-9 sensor and a TGS2610 sensor. The readings of these sensors are processed by Arduino Uno. The system output is made in the form of a buzzer and LCD. Tests carried out on the car cabin area are divided into three, namely front, middle, and rear. The results of the 6 tests show that the smallest percentage of CO errors is 8% in the middle area and HC of 8.7% in the rear area of the car cabin.

Design and Development of Variable overhang chassis mechanism

This mechanism is designed in such some way that the vehicle can have safe, simple and stable mobility even at the higher speeds. To confirm that the overhang is safe and secure while expansion and retraction positions. This mechanism will be powered by hydraulics and electronics by functionality. As this mechanism only be used for electric vehicles, it brings a modern approach for utilizing the massive existing space in the electric vehicle and proving additional safety to the vehicle This concept of the variable overhang mechanism also provides a new approach in designing the vehicle of future as the frontal crumple zone will be expanded and retracted in accordance to the speed variation. This system will be acting as an active safety system providing different configurations in adjustment to the road conditions and speed variations. Among the major road crashes which occurs in our day to day lives, most of those crashes are notes as head on collision. The current safety systems such as seatbelts and airbags perform a good job in safeguarding a person from upcoming injuries but despite of them we still require an additional system which will further improve the current safety conditions. This design will function by variable overhang mechanism which will further be helpful in crash reduction and will support vehicle as an added safety. In addition to this, it will support vehicle as a safety component by the introduction of honeycomb bumper, which will further sustain the impact and would be a great tool of utility. The honeycomb bumper will help sustaining the initial impact of the vehicle over crashes. This will result in drastic impact reduction at cabin area and improvising the safety conditions for the vehicle and certainly limit the impact transfer to the passenger cabin area. This safety feature will work on the principle of crumple zone, where the front mechanism of the vehicle will act as the frontal crumple zone to the vehicle by its self-breakdown tendency.

ARAÇLARDA KABİN İÇİ SESLERİ ETKİLEYEN PARAMETRELERİN TESTLERLE İNCELENMESİ

Vehicles with improved driving comfort are produced in order to be more competitive in the developing automotive sector. One of the parameters that affect driving comfort is the acoustic performance of the vehicle in the cabin. The most explicit sounds that affect the cabin area are road, wind, wheel, trim, and engine sounds. In this study, vibration accumulation on the body of the vehicle has been determined. Accordingly, the vehicle body has been improved with isolation, and sound assessment has been done inside the cabin. It has been determined that the acoustic performance is improved with the isolation improvements in the vehicle. Afterward, the effect of engine types, different body types for the same kind of engine, wheel rim effects, and engine mounts on the interior sound level is examined. In the examination of acoustic performance, it is determined that the articulation index is determinant rather than the sound level. The isolation effect on the vehicle body and the impact of the engine mounts are evaluated by the jury tests.

A Preliminary Numerical Investigation of Airborne Droplet Dispersion in Aircraft Cabins

The emergence of the novel coronavirus has led to a global pandemic which has led to the airline industry facing severe losses. For air travel to recover, airlines need to ensure safe air travel. In this paper, the authors have modelled droplet dispersion after a single breath from an index patient. Computational Fluid Dynamics (CFD) simulations are conducted using the k-w SST turbulence model in ANSYS Fluent. The authors have taken into consideration several parameters such as the size of the mouth opening, the velocity of the cabin air as well as the number of droplets being exhaled by the index patient to ensure a realistic simulation. Preliminary results indicate that after a duration of 20s, droplets from the index patient disperse within a 10 m2 cabin area. About 75% of the droplets are found the disperse for up to 2m axially behind the index patient. This could possess an enhanced risk to passengers sitting behind the index patient. Ultimately, this paper provides an insight into the potential of CFD to visualise droplet dispersal and give impetus to ensuring necessary mitigating measures can be taken to reduce the risk of infection through droplet dispersal.

A Two-Phase Stowage Approach for Passenger-Cargo RoRo Ship Based on 2D-KP: Coping With Complex Rotation and Safe Navigation Constraints

The passenger-cargo Roll on/Roll off ship stowage (PRSS) is the core step of passenger-cargo Roll on/Roll off (RoRo) transportation. The layout of vehicles in the cabin is directly related to the space utilization of the cabin and the efficiency of stowage operations, which in turn affects the economic benefits of the port. In this paper, we address the PRSS problem in the context of passenger-cargo RoRo transportation in the Qiongzhou Strait of China. By focusing on the utilization ratio of the cabin area, the PRSS problem can be viewed as a special version of a two-dimensional knapsack packing (2D-KP) problem with additional constraints, such as two-phase, complex rotation and safe navigation constraints. Then we present a mixed integer linear programming (MILP) mathematical model and an algorithm framework to tackle the PRSS problem. In the algorithm framework, a novel multi-phase heuristic stowage method is proposed to improve the current manual stowage decision-making state which completely depends on operational experience. Finally, several instances are generated based on the realistic date of Qiongzhou Strait to verify the effectiveness of the model and stowage method. Computational results show that the proposed model and stowage method are well suited to solve the PRSS problem and the algorithm framework has a strong robustness in large-scale application experiments.

Demonstration of Active Vibration Control System on a Korean Utility Helicopter

Technology demonstration program was performed between June 2013 and January 2014 in Sacheon Korea to validate the performance of LORD Corporation (LORD)-designed active vibration control system (AVCS) on Korean Utility Helicopter platform. Optimal configuration of actuators was investigated by numerical calculation using ground and flight test data, and its performance was evaluated through the flight tests. 14 control accelerometers were used for vibration-level measurement and optimal configuration of 2–6 circular force generator test groups was investigated. Although the predicted vibration levels of aircraft showed better performance with increasing number of actuators, the weight and cost trade-off should be considered during the design. Flight tests showed that the vibration levels with AVCS at the cockpit area and the cabin area were reduced more than that of the tuned vibration absorber (TVA). Moreover, it was possible to configure AVCS with lower weight than the TVA.

MFVS/MIMU integrated 6-DOF autonomous navigation in known environments with extremely simple landmarks

This study presents the navigation system of an inboard spacecraft (IS) of the Tiangong space station. This system comprises a multiple field-of-view vision system (MFVS) and a micro inertial measurement unit (MIMU). The MFVS utilizes three mutually orthogonal cameras and takes sparse and identical vision beacons as navigation references. A practical model for the MFVS is proposed based on a pseudo-measurement, which refers to the beacon coordinates in the camera frames. On this basis, three sub-algorithms for image processing and measurement equation forming are designed. Accelerated feature extracting and matching, dilution of precision analysis-based vision beacon selection strategy, and MIMU-aided image smearing elimination are analyzed. An extended Kalman filter is utilized to couple the MFVS and MIMU tightly. The 6-degree-of-freedom pose of the system and the vision beacon coordinates are estimated. The proposed algorithm is verified through a navigation experiment. Results inside a simulated cabin area of 1.5 m3 are obtained. The attitude and position accuracy in each axis reach within 0.04° and 0.41 mm (1σ), respectively. The proposed algorithm meets the requirement of the IS navigation and has potential application in other similar conditions.

Research on Occupant Evacuation Simulation during Civil Aircraft Emergency

Abstract In order to simulate aircraft evacuation process vividly in the 90s certification trials, the influence elements of occupant evacuation during aircraft emergency need to be analyzed. These elements were achieved as evacuee element, aircraft type element, and aircraft external environment element. The three elements were consisted of several factors respectively. In evacuee element contained individual physiological factor and psychological factor, the diversities of individual behavior were discussed in the three escape stages. These factors were applied to cellular automata theory. Then, the cabin environment model was established according to the characteristics of occupant movement during emergency evacuation, and the non-wing exit escape time model was built through a self-designed jumping slide experiment. This research took B737-800 as the experiment prototype and developed the simulation software (EES-air) based on the above models and the existing research results. Three distribution plans of occupant evacuation in cabin area were designed in the simulation software. The simulation results were analyzed from the evacuation efficiency, the number of escape at different time, and the available exit utilization rate. The research results could provide strategy and guidance to emergency evacuation and emergency training for airline.

Drop test simulation and validation of a full composite fuselage section of a regional aircraft

In the aircraft industry, the use of fiber reinforced materials for primary structural components over metallic parts has increased up to more than 50% in the recent years, because of their high strength and high modulus to weight ratios, high fatigue and corrosion resistance. Currently, the need of lowering weight and fuel consumption is pushing the world’s largest aircraft manufacturers in the design and building of structures entirely made of composites.Fuselage structure plays an important role in absorbing the kinetic energy during a crash. Through the deformation, crushing and damage of fuselage sub-floor structure, a survivable space inside the cabin area should be preserved during and after a crash impact in order to minimize the risk of passengers’ injuries.In this work, a Finite Element (FE) model of a full-scale 95% composites made fuselage section of a regional aircraft under vertical drop test is presented. The experiment, conducted by the Italian Aerospace Research Centre (CIRA) with an actual impact velocity of 9.14 m/s in according to the FAR/CS 25, has been numerically simulated. Two ATDs (Anthropomorphic Test Dummies), both 50th percentile, seats and belts have been modelled to reproduce the experimental setup. The results of the simulation, performed by using LS-DYNA® explicit FE code, have been validated by correlation with the experimental ones. Such comparisons highlight that a good agreement has been achieved.The presented FE model allows verifying the structural behavior under a dynamic load condition and also estimating the passive safety capabilities of the designed structure. Since the experiment is expensive and non-repeatable, a FE model can be used for Certification by Analysis purposes since, if established, it is able to virtually demonstrate the compliance to the airworthiness rules.

Noise Control Transmission Methods of the Combustion Engine by Means of Reduction of the Vibration

Abstract Transmission of vibroacoustic energy from an internal combustion engine (ICE) to its surroundings largely depends on how it is mounted, on available transmission paths and on the construction of the vehicle body and/or its surrounding structures. This is especially true in low speed engines in enclosed areas which generate perceptually weak noise, but strong low-frequency waves which energy has a negative impact on human health, comfort and driving safety especially in prolonged exposure to the source. The primary aim of the article was to analyse components of the ICE unit which had a determining impact on the reduction of low-frequency waves. Thus, the structurally transmitted noise from the ICE to its surrounding structure (body of the passenger vehicle) was analysed. The results of the vibroacoustic measurements were compared to modal analysis in order to determine possible resonance sources in the vehicle body and/or for assessing the influence of the vehicles safety gear on the generated vibroacoustic energy transfer into the cabin area of the passenger vehicle. Measurements were made for a passenger vehicle at rest and operating in its most common operational speed as well as for the stationary ICE of a cogenerate unit (CGU). Measurements and FFT analysis were used for the detection of the vibroacoustic energy sound pressure level (noise) and mechanical vibration. Firstly, the low-frequency noise sources were determined and their direct effects on the human body were investigated. Finally, this paper suggests some measures which may contribute to the reduction of undesirable vibroacoustic energy in enclosed areas.

선박 거주구역의 방호를 위한 폐쇄형 미분무 노즐의 화재진압성능평가 연구

Since accommodation, public space and service areas where people stay for all day occupy about 70% of a huge cruise ship, they have to be protected from the fire. International Maritime Organization has resolved that a water mist system should be equipped in this cruise ship according to SOLAS II-2 Reg. 10.6 and FSS code Ch. 7. The water mist system consists of mist nozzles, pressure vessels, section valves and pump unit etc. In particular, the water mist nozzles should be recognized by fire tests in accordance with IMO Res. MSC 265(84). In this study, the fire tests for cabin, corridor, public space and storage area have been conducted to develop the water mist nozzles appropriate to the regulation. Totally 5 types of nozzles were developed and have satisfied the whole performance requirements.