Cargo Compartments Research Articles

E-Commerce Delivery Optimization with Bicycle Deliveryman and Dual Autonomous Robots

The rapid growth of e-commerce has led to a surge in package deliveries, particularly during promotional events, resulting in increased workload for deliveryman. To address this challenge, this paper explores traveling salesman problem with bike and two autonomous delivery robots-referred to as 2TSPBR. The robots, each with three different-sized cargo compartments, are responsible for delivering packages of varying sizes. When their inventory is low, they restock from the bicycle’s service points. The Variable Neighborhood Search (VNS) algorithm is employed to generate and optimize delivery routes for the bicycle and robots. The results indicate that the VNS algorithm significantly outperforms the CPLEX solver in terms of computational time, providing rapid convergence to near-optimal solutions. This study demonstrates the efficiency and effectiveness of the proposed VNS algorithm in delivering accurate solutions for the integrated delivery system.

Early fire detection technology based on improved transformers in aircraft cargo compartments

The implementation of early and accurate detection of aircraft cargo compartment fire is of great significance to ensure flight safety. The current airborne fire detection technology mostly relies on single-parameter smoke detection using infrared light. This often results in a high false alarm rate in complex air transportation environments. The traditional deep learning model struggles to effectively address the issue of long-term dependency in multivariate fire information. This paper proposes a multi-technology collaborative fire detection method based on an improved transformers model. Dual-wavelength optical sensors, flue gas analyzers, and other equipment are used to carry out multi-technology collaborative detection methods and characterize various feature dimensions of fire to improve detection accuracy. The improved Transformer model which integrates the self-attention mechanism and position encoding mechanism is applied to the problem of long-time series modeling of fire information from a global perspective, which effectively solves the problem of gradient disappearance and gradient explosion in traditional RNN (recurrent neural network) and CNN (convolutional neural network). Two different multi-head self-attention mechanisms are used to classify and model multivariate fire information, respectively, which solves the problem of confusing time series modeling and classification modeling in dealing with multivariate classification tasks by a single attention mechanism. Finally, the output results of the two models are fused through the gate mechanism. The research results show that, compared with the traditional single-feature detection technology, the multi-technology collaborative fire detection method can better capture fire information. Compared with the traditional deep learning model, the multivariate fire prediction model constructed by the improved Transformer can better detect fires, and the accuracy rate is 0.995.

Use of Modular and Wearable Technical Means of Disinfection During Liquidation of Emergency Situations

In the process of liquidation of emergency situations of biological nature (ESBN) by the NBC Protection Corps of the Armed Forces of the Russian Federation, the modern modular and wearable technical means of disinfection based on an aerosol method of treatment of objects were widely used. The purpose of the work is to summarize experience of the use of modular and wearable technical means of disinfection during the liquidation of biological emergency. The most intensive use of mobile technical means of disinfection was carried out for more than two years in Chkalovsky airfield by the combined NBC protection group, which carried out work on the disinfection of aircraft of the Military Space Forces and the cargo transported by them against the pathogen of coronavirus infection. The main volume of work on disinfection of cargo compartments and cockpits of pilots of aircraft as well as cargo was performed in the aerosol method with the use of the following technical means: CDA (Aerosol Disinfection Complex) complex, the bagpack motorized and manual sprayers. The aerosol treatment method and the formulation based on ethyl alcohol provided high productivity of works, low manual labor costs, and reliable disinfection of objects with low consumption of preparation. Thus, the processing time of the cargo compartment of AN-124 aircraft with the help of autonomous modules of the CDA or backpack sprayers STIHL SR 450 did not exceed 20 minutes, and the consumption of the recipe was not more than 100 cm 3 ×m -2 . The use of modern modular and wearable disinfection means in the NBC protection units will ensure the increase of efficiency of disinfection measures in the interests of troops and population of the Russian Federation.

Numerical simulation of the synergistic effects of unwanted combustion enhancement by the C3H2F3Br and C2HF5 blends

Owing to the restriction of using Halon 1301 (CF3Br) for fire suppression, several alternatives to Halon 1301 have been developed, including C2HF5 (HFC-125), C3H2F3Br (2-BTP), and C6F12O (Novec1230). However, in the Federal Aviation Administration (FAA) Aerosol Can Explosion Test (FAA-ACET), it was found that these alternatives did not suppress lean flames at sub-inert concentrations, but promoted combustion, eventually leading to overpressure. Therefore, they have not been successfully applied in aircraft cargo compartments. Herein, different blend ratios of C3H2F3Br and C2HF5 were used to explore their inhibitory effects on combustion enhancement under lean combustion conditions. A chemical kinetic model was developed and validated using a one-dimensional free-propagation flame simulator. The laminar burning velocity predicted by the model was consistent with the experimental results. The adiabatic flame temperature and overall reaction rate were determined using thermodynamic equilibrium calculations and perfectly stirred reactor (PSR) simulations. By comparing the blend inhibitors with different blend ratios, it was found that the blend of C3H2F3Br and C2HF5 at blend ratios of 25/75 and 50/50 effectively reduced the total heat release and system reactivity. In addition, the blend inhibitor not only weakened the fuel properties of C2HF5, but also further enhanced the bromine-catalysed radical recombination cycle. Notably, a new reaction occurred when C3H2F3Br and C2HF5 were blended into the FAA-ACET chamber: Br + CHF2CF3 = HBr + CF3-CF2, indicating that the Br atoms promoted the decomposition of C2HF5.

МИКРОПРОЦЕССОРНАЯ СИСТЕМА АВТОМАТИЧЕСКОГО УПРАВЛЕНИЯ СРЕДСТВАМИ ПРОТИВОПОЖАРНОЙ ЗАЩИТЫ САМОЛЕТА

Relevance The ever-increasing requirements for the safety of the use of aviation technology are inextricably linked with the problem of providing fire protection for aircraft, both military and civilian. The complexity of the problem of ensuring the fire safety of flights is associated with an increase in the intensity of the use of aviation equipment and the expansion of the range of functional tasks performed by it. The resulting complication of on-board equipment and an increase in the number of energy-intensive devices creates the prerequisites for the occurrence of fires on board the aircraft. At the same time, the remoteness of places where fires are possible, the variety of causes leading to fires, as well as the ambiguity of the conditions for the onset and spread, increase the likelihood of equipment failures, but also complicate the crew's activities. The purpose of the study is to implement a prospective aircraft fire protection system that will increase the effectiveness of existing fire extinguishing equipment. The relevance of this research project lies in the creation of an aircraft fire-fighting system that will provide timely detection of overheating/fire in the nacelles of the main power unit, in the compartments of the auxiliary power unit, baggage and cargo compartments and aircraft toilets; reliability of information from fire detection and elimination systems; increase the effectiveness of existing firefighting equipment. Aim of research The aim of the study is to develop a future aircraft fire protection system that will increase the effectiveness of existing fire extinguishing equipment. The objectives of the research project are: 1. Choosing a hardware complex for electronic indication and signaling of the aircraft fire-fighting system; 2. Integration of the fire protection complex into the general aircraft equipment control system. Research methods Analysis of modern high-performance aircraft fire protection systems and creation of a promising fire protection system based on the data obtained Results In the course of this research project, a hardware complex for electronic indication and signaling of the aircraft fire system was selected, and the integration of the fire protection complex into the control system of general aircraft equipment was carried out.

Сargo carrying capacity calculation for combined ships in optimization problem for ship’s main elements

This article is devoted to the development of the cargo carrying capacity evaluation method for a combined ship of tanker/platform type. A specific feature of cargo carrying capacity calculation for such ships lies in the fact that they have two cargo compartments of different structure. The compartments are interconnected, including dimensions, and influence each other. This fact leads to the need to update the existing calculation methods when justifying the main dimensions both of tankers and of platform ships. It is proposed to include the parameters which affect the cargo carrying capacity and take into account the above mentioned influence into the cargo carrying capacity equations. This article also specifies the determination methods for these parameters in the early stages of ship designing. All this made it possible to obtain relations, the inclusion of which into the mathematic model of optimization problem for main elements of a combined ship (tanker/platform type) allows proper evaluation of all available options of main dimensions in terms of their compliance with carrying capacity for each specific cargo as well as exclusion of improper options from consideration.

Nitrogen as an environmentally friendly suppression agent for aircraft cargo fire safety

Fire suppression systems in cargo compartments are a certification requirement for commercial aircraft safety. Halon production was banned and usage ends in 2040 according to Montreal Protocol for environmental reasons. This necessitates an alternative environmentally friendly agent. Quantitative analysis of nitrogen as agent established suitability of the suppression system. The Minimum Performance Standards specifies the qualification procedure of an agent through four scenarios – bulk load; containerised load; surface burning; and aerosol can explosion. Empirical sources from Airbus, independent computational fluid dynamics studies and small-scale cup-burner tests indicate suitability of nitrogen specific to aircraft cargo fire suppression. The nitrogen delivery system and the experimental apparatus are presented. Extensive commissioning tests verified instrumentation reliability. All the four scenarios were conducted at Cranfield University, in a replica of a wide-body aircraft cargo compartment. In a reduced oxygen environment (11%) obtained with nitrogen discharge, the aerosol can explosion tests were performed without any evidence of explosion or pressure increase beyond the expected baseline value. The surface burning scenario was completed successfully and passed the Minimum Performance Standard criteria. The maximum average temperature was found to be 220°C (limit – 293°C). All the scenarios passed the Minimum Performance Standard criteria for indicating successful prevention of Class B fire re-ignition. Similarly, the containerised and bulk-load scenarios obtained results that passed the Minimum Performance Standard criteria for successfully maintaining continued fire suppression for a specified period of time. The maximum average temperature in containerised-load fire scenario was found to be 210°C (limit – 343°C) and in bulk-load scenario was 255°C (limit – 377°C). Additional qualification criteria and system design are presented in this article according to the Minimum Performance Standard format. This work can be extended to introduce standard testing for safety critical systems, such as engine bay and lithium-ion fires.

Numerical assessment for aircraft cargo compartment fire suppression system safety

Fire on board an aircraft cargo compartment can lead to catastrophic consequences. Therefore, fire safety is one of the most important considerations during aircraft design and certification. Conventionally, Halon-based agents were used for fire suppression in such cases. However, an international agreement under the Montreal Protocol of 1994 banned further production of Halon and several other halocarbons considered harmful to the environment. There is therefore a requirement for new suppression agents, along with suitable system design and certification. This article aims to describe the creation of a mechanism to validate a preliminary design for fire suppression systems using Computational Fluid Dynamics and provide further guidance for fire suppression experiments in aircraft cargo compartments. Investigations were performed for the surface burning fire, one of the fire testing scenarios specified in the Minimum Performance Standard, using the numerical code Fire Dynamics Simulator. This study investigated the use and performance of nitrogen, a potential replacement for Halon 1301, as an environmentally friendly agent for cargo fire suppression. Benchmark fires using the pyrolysis model and fire design model were built for the surface-burning fire scenario. Compared with experiment results, the two Computational Fluid Dynamics models captured the suppression process with high accuracy and displayed similar temperature and gas concentration profiles. Fire consequences in response to system uncertainties were studied using fire curves with various fire growth rates. The results suggested that using nitrogen as a fire suppression agent could achieve a lower post-suppression temperature compared to a Halon 1301-based system. It can therefore be considered as a potential candidate for aircraft cargo fire suppression. Such work will feed directly into system safety assessments during the early design stages, where analyses must precede testing. Future work proposed for the application of this model can be extended to other fire scenarios such as buildings, shipping, and surface transport vehicles.

비밀폐계에서 CO2 소화에 영향을 미치는 인자에 관한 연구 : 선박화재 사례에서

In the ship fire, the initial fire extinguishing is very important because evacuation space is limited. Large ships are equipped with various extinguishing devices such as portable and fixed extinguishing equipment. The CO2 extinguishing equipment which lowers the oxygen density is one of the devices used in the ship fires. In actually, when a lot of fires occur in the engine room of a ship, a CO2 extinguishing system is often used to extinguish the fire. However, there is a space in the ship that can not be sealed in a large space such as a cargo storage compartment. The fire often occur in cargo compartments. In general, it is understood that CO2 extinguishing must be used in sealed spaces to be effective. Almost studies on the effectiveness of CO2 extinguishing systems for ship fires have been conducted only in a completely closed system such as an engine room. At present, studies on the effectiveness of CO2 extinguishing when there is no closed system has been insufficient. If the initial suppression of the fire is not successful, the combustion will increase, making it difficult to identify the exact cause of the fire. It is important to identify the cause of all fires, but especially for ship fires, it is very important to extinguish the fire early in order to identify the cause of fire. Therefore, in this paper, we analyzed the factors affecting CO2 extinguishing in an unsealed space based on the case of ship fire and investigated the effectiveness of CO2 extinguishing by approximating actual fire cases.

Magnetically Driven Nanotransporter-Assisted Intracellular Delivery and Autonomous Release of Proteins.

Biofunctional proteins such as active enzymes and therapeutic proteins show tremendous promise in disease treatment. However, intracellular delivery of proteins is facing substantial challenges owing to their vulnerability to degradation and denaturation and the presence of various biological barriers such as their low membrane transport efficiency. Herein, we report a magnetically driven and redox-responsive nanotransporter (MRNT) for highly efficient intracellular delivery of biofunctional proteins. The MRNT has remarkably high cargo capacity, compared with that without nanoscale cargo compartments. We have demonstrated the directional and dynamic motion of the MRNT using both nanoparticle tracking analysis and magnetic driving evaluation. Moreover, the active MRNT can translocate into the cytosol and sense the reducing cytosolic environment to discharge protein cargoes autonomously. The internalization mechanism of the MRNT has been studied using endocytosis inhibitors. Under the magnetic drive, the MRNT can promote a protein transduction efficiency of over 95%, and the intracellular protein delivery by the active MRNT shows significantly higher (∼4 times) enzymatic activity and therapeutic efficiency than those achieved by the static ones. Our proof-of-concept study provides a valuable tool for intracellular protein transduction and contributes to biotechnology and protein therapeutics.

Pool fire suppression performance by twin‐fluid water mist under low pressures in an altitude chamber

AbstractFire suppression tests using low pressure twin‐fluid water mist under low pressure environments were carried out to exam the performance of water mist systems at low pressure environments. The experiment results show that the suppression time gets shorter for lower chamber pressure, and relevant total weight of water and nitrogen used decreases as the chamber pressure gets lower. For the case of 30‐cm diameter pool fire, the suppression times are 20.19, 7.5, and 2.24 under the chamber pressure of 60, 38, and 24 kPa, respectively. In case of a cargo compartments fire, it is suggested to open the ventilation valve of the cargo compartment at a high cruising altitude to relieve pressure, so as to achieve rapid fire suppression. When a fire happens at the position off the center below the water mist nozzle, the water mist suppression effects will be weakened. The fire size has little effects on the fire extinguishing process under pressure of 24 kPa. Under the critical atomization condition with the pressure differential between the inlet and outlet of the nozzle for water as 0.05 MPa (5.04 L/min), and the pressure differential for nitrogen as 0.10 MPa (10.97 L/min), the suppression time is the shortest as 18.66 seconds.

Proteomic analysis of two populations of Schistosoma mansoni-derived extracellular vesicles: 15k pellet and 120k pellet vesicles

Helminth parasites secrete extracellular vesicles (EVs) into their environment that have potential roles in host-parasite communication, and thus represent potentially useful targets for novel control strategies. Here, we carried out a comprehensive proteomic analysis of two different populations of EVs – 15k pellet and 120k pellet EVs – from Schistosoma mansoni adult worms. We characterised the proteins present in the membranes of the EVs (including external trypsin-liberated peptides, integral membrane proteins (IMPs) and peripheral membrane proteins (PMPs)), as well as cargo proteins, using LC–MS/MS. A total of 286 and 716 proteins were identified in 15k and 120k pellets, respectively. Some of the most abundant proteins identified from both 15k and 120k pellets include known vaccine candidates such as Sm-TSP-2, saponin B domain-containing proteins, calpain glutathione-S-transferase, Sm29 and cathepsin domain-containing proteins. Other abundant proteins that have not been tested as vaccines include DM9 domain-containing protein, 13 kDa tegumental antigen and histone H4-like protein. Sm23, a member of the tetraspanin family with known vaccine efficacy, was identified in the cargo and IMP compartments of only 15k pellet vesicles. Moreover, a collection of proteins with known or potential relevance in host-parasite communication including proteases, antioxidants and EV biogenesis/trafficking of both vesicle types were identified. Our results provide the first report of a comprehensive compartmental proteomic analysis of adult S. mansoni-derived EVs. Future research should investigate recombinant forms of these proteins as vaccine and serodiagnostic antigens as well as the roles of EV proteins in host-parasite communication.

Comparison Between Actual and Simulated Smoke for Smoke Detection Certification in Aircraft Cargo Compartments Using the CFD Method

Simulated smoke has been widely used in place of actual fire smoke during flight tests in the certification process for aircraft cargo compartment smoke detection systems. Previous research has identified several differences between actual and simulated smoke. However, few studies have determined the quantitative effects of these differences on the transport and detection properties of actual and simulated smoke. The current work compared actual and simulated smoke using a computational fluid dynamics method with numerical models for the two types of smoke developed in the Fire Dynamics Simulator of the National Institute of Standards and Technology and validated through experimental data. The transport and detection properties of actual and simulated smoke were then evaluated quantitatively in detail. The two types of smoke were compared under two conditions: (1) at the same smoke-generating quantity and (2) at the same smoke release rate. Result showed that during the early stage of smoke occurrence, the numerical values of light transmission at different monitoring points in simulated smoke are 10% to 20% lower than those in actual fire smoke. Simulated smoke from the smoke generator is easier to detect than actual fire smoke. Therefore, the equivalence between simulated smoke and actual fire smoke should be focused on in the airworthiness verification of aircraft cargo smoke detection.

Elements of the synthesis method for the layout of a front-line aircraft

The article describes a technique that allows to form a planned projection of the aircraft using the minimum number of iterations (refinements based on aerodynamic and weight calculations results). The elements of the technique are described via example of the development (synthesis) of the layout scheme of a front-line aircraft with two engines and internal cargo compartments, performed according to the normal balancing scheme. Synthesis is carried out on the basis of certain predesign parameters, limitations, as well as solutions set by the designer, based on the analysis of parametric ratios and statistical dependencies.

Load planning processes to enhance cargo compartment utilization

Purpose The United States Air Force often provides effective airlift for cargo distribution, but is at times inefficient. This paper aims to address the under-utilization of military airlift cargo compartments that plagues the airlift system. Design/methodology/approach The authors examine seven techniques designed to increase cargo compartment utilization and increase airlift utilization rates. The techniques were applied through load planning software to 30 real-world movements consisting of 159 sorties. They then ran each post-technique movement through a modeled flight environment to obtain cycle movement data. The metrics gained from both the load planning software and the modeled environment were regressed to provide statistical understanding regarding how well each technique influenced cost savings. Findings The results showed a 24 per cent elimination of aircraft required and a savings of $14.5m. Extrapolation of the authors’ findings to four years of airlift mission data revealed an estimated annual savings of $1.6bn. Originality/value This research effort provides multiple options to improve the efficiency and effectiveness of military airlift.

Large-sized transformable space antenna reflector made оf composite materials dynamic modeling process

Large space structures (LSS) occupy a special place among other objects of space technology. Due to their large size, these structures are compactly stowed under the fairings of the launch vehicles or in the cargo compartments of the Space Shuttle type spacecraft. After launch into the working orbit, they are deployed automatically into the predetermined configuration with the help of transformable elements, which act both as the load-bearing frame and actuators. The deployment should be carried out within the specified time and should not negatively affect the strength, shape or spatial orientation of the structure. To meet these requirements, it is necessary to theoretically investigate the deployment dynamics of the LSS under consideration. This paper aims to find the optimal design and engineering solutions of an ultralight transformable reflector for a space antenna made of metal mesh with load-bearing elements in the form of telescopic hollow rods made from carbon fiber reinforced plastic. The deployment dynamics of the load-bearing elements with the mesh attached was modeled using the Russian-made software package EULER 10.25. The modeling allowed us to estimate the effect of the tensile load from the mesh on the deployment process. With the elastic load from mesh accounted for, the stability and rigidity of the load-bearing elements will be ensured and the accuracy of the mesh tension will be increased.

Influence of depressurized environment on the fire behaviour in a dynamic pressure cabin

Aircraft cargo compartments usually undergo a dramatic pressure change during an emergency landing. Understanding fire behaviour in this dynamic-pressure environment is important for controlling aircraft fires. Pool fire experiments were conducted in a 3m×2m×4.65m cabin to analyze fire behaviour in an environment with varying pressure. A pressure control system was used to reduce cabin pressure during the fire. N-heptane pool fires with diameters of 20cm and 30cm were tested under depressurization from 101kPa to 24kPa with depressurization rates of 148Pa/s, 208Pa/s, 261Pa/s, and 304Pa/s. Fire behaviour such as burning rate, flame height, and flame temperature were analyzed. The results revealed that as the pressure is reduced, the burning rate decreases, which agrees with radiation modeling. Flame height increases as a power function of pressure while the peak time is earlier than the end time of depressurization. Three regions of flame all elongate and flame temperature in each region shows different trends. Moreover, there is a delay for the fire behaviour to reach the next quasi-steady stage after the depressurization, which can be divided into the transition stage.

Nitrogen Fire Extinguishing System in Airplanes Cargo Compartments

Nitrogen Fire Extinguishing System in Airplanes Cargo Compartments

Cargo Compartment Fire Extinguishing System

In all large passenger transport airplanes, halon fire bottles are used to extinguish fire in the cargo compartments. Halon as a fire-extinguishing agent, contributes to the destruction of stratospheric ozone in the atmosphere and it is banned in many countries. FAA considers halon 1301 as an effective firefighting agent due to its low toxicity and noncorrosive properties but because it damages the ozone layer, it has been phased out of production. However, it is still widely used on commercial aircraft until a suitable replacement is found. In this paper we will present an alternative approach to using halon 1301 as a fire fighting paradigm. In the proposed method, nitrogen is first extracted from the atmosphere by using the onboard air separator module it is then cooled, and pressurized into the cargo compartments to suppress any fire. Several methodologies can be used to increase the flow rate from the air separator module, to extinguish fire in cargo compartment.

Premixed flame inhibition by C2HF3Cl2 and C2HF5

This study is the first to examine the inhibition effectiveness of C2HF3Cl2 (HFC-123) on premixed hydrocarbon–air flames and is motivated by the eventual phase-out of CF3Br (Halon 1301) used in civilian aircraft cargo compartments. To study the inhibition effectiveness, we measured the laminar burning velocity of CH4–air flames with added C2HF3Cl2 in a spherical, constant-volume combustion vessel, over a range of inhibitor concentration and fuel–air equivalence ratio. Burning velocities at ambient (T = 298 K; P = 1.01 bar) and elevated (T = 400 K; P = 3 bar) conditions were compared to numerical predictions obtained using a newly-developed kinetic mechanism describing the decomposition of hydrochlorofluorocarbons (HCFCs) in hydrocarbon–air systems. The agreement was very good, considering the model parameters were not adjusted, and the present study was the first to test the mechanism against experimental data of a two-carbon HCFC. In addition to providing model validation, the effectiveness of C2HF3Cl2 was compared to the analogous HFC compound C2HF5 to explore the advantages of Cl substitution for F. Experimental measurements of agent influence on burning velocity, as well as numerical modeling of premixed flame structures, demonstrated that C2F3Cl2H is a more effective flame inhibitor than C2F5H, particularly for very lean CH4–air mixtures. The reaction pathways and sensitivities were analyzed to interpret the differences in the inhibition mechanisms of C2F5H and C2HF3Cl2 and to prioritize elementary reactions for further study.