Deriving Major Fire Risk Evaluation Items Utilizing Spatial Information Convergence Technology in Dense Areas of Small Obsolete Buildings

As small obsolete buildings are exposed to high fire risks, governments are trying to evaluate their fire risks and preferentially improve fire protection performance for high risk buildings, however, the evaluation manpower and time are insufficient compared to the rapidly increasing number of obsolete buildings. Therefore, this study aimed to derive major fire risk index (FRI) evaluation items as part of developing a platform to quickly and efficiently evaluate fire risks in dense areas of small obsolete buildings utilizing spatial information convergence technology. To this end, 20 preliminary evaluation items specifically tailored to dense areas of small obsolete buildings were derived through a field survey, investigation of FRI evaluation items from existing works, and expert pre-reviews. Based on the derived 20 preliminary items, an importance survey was conducted with a total of 181 fire safety experts including fire officers, university professors, researchers, industry experts, and fire insurers. As a result, a total of 12 major evaluation items (e.g., outdoor fire extinguisher, distance to 119 Safety Center, building structure, building cladding, illegal alterations, illegal parking, and liquefied natural gas cylinder) were derived. Results can help to evaluate the fast and efficient fire risks in dense areas of small obsolete buildings.

Design, Construction and Performance Evaluation of a Dual-Powered Cooker

A dual-powered cooker is a combination of components that makes possible the use of alternative heat sources. Due to the irregular power supply common in developing countries, as well as the growing high cost of hydrocarbon fuel sources, the need arises for the development of a dual energy source that uses both electricity and gas for heating and cooking. The aim of this research work is to design, construct and carry out a performance evaluation of a dual-powered cooker. The materials for the research work were locally sourced and selected based on suitability in reference to the design requirement of the cooker. The cooker consists of two divisions, each fitted with a burner operating on distinct energy sources, electricity and gas. Within the electric burner is a heating element that generates and dissipates heat across a hotplate. On the other hand, cooking gas is supplied to the burner located at the other segment of the cooker via a threaded pipe connection to a gas cylinder, secured unto a control mechanism that allows the burning rate to be varied progressively and continuously. The temperature of the water was allowed to synergize with the ambient temperature of the room before testing. Several important findings can be drawn from this assessment. The gas cooker has a higher overall thermal efficiency between (57.50% [without lid] - 62.84% [with lid]) as opposed to the efficiency of its electric counterpart, which falls between (29.78% [without lid] - 39.12% [with lid]). The dual-powered cooker was successfully designed, constructed and evaluated. The gas cooker has a higher efficiency than the electric cooker. Primarily, the gas cooker is at an advantage as it does not need to preheat or rely on power from an electric source subject to fluctuation in voltage before cooking, unlike the electric cooker; therefore, making it better at a wider range of cooking operations.It combines the best of gas and electric cookers. Gas hobs that are quick to heat up and easy to control, plus electric ovens with more accurate heat settings and multiple features.

Fretting Wear of Rubber Sealing Ring Caused by Fluid Pressure Fluctuation

In the process of gas charging and discharging of gas cylinder, the fluid pressure fluctuates causing fretting wear of rubber sealing ring, which affects the sealing performance. The model of O-ring that installed at the mouth of the gas cylinder was established to study the fretting wear in the static seal. Effects of fluid pressure, compression ratio, friction coefficient and temperature on the fretting wear of the O-ring were considered. The results show that the fretting wear of O-ring can be divided into non-contact region, slip region and sticky region. In the static seal, the compression ratio and friction coefficient are the main factors affecting the fretting wear. The sealing performance is greatly influenced on the compression ratio and it is less affected by the temperature. The junction of slip region and sticky region has the greatest probability of seal failure.

Manufacturing and Characterization of Open-Cell Aluminum Foam Produced via Infiltration of Leachable Space Holder

Open-cell Al-Si foam samples were produced using infiltration casting technique. The metal infiltration process was performed in a specially designed and built setup consisting of a vertical chamber resistance furnace, a pressurization chamber connected to an Argon gas cylinder through a control manifold. To control the relative density of the produced foams, non-compacted and compacted preforms (5 MPa) were prepared from 2 or 4 mm NaCl particles. The compaction was performed using a hydraulic press in the same infiltration chamber. Argon pressure of 3 bars was applied to infiltrate the preforms with the aluminum alloy after melting at 750 °C. The produced aluminum foam specimens show no lack of filling, a high degree of preform replication, and good homogeneity of pore sizes. The preliminary physical and mechanical characterization tests, including relative density, plateau stress, densification strain, and elastic modulus of the foam, are comparable to the values reported in previous investigations, in which more complicated, time-consuming, higher energy, and costly techniques were used. Further investigations on wider ranges of particle sizes, compaction, and infiltration pressures are currently in progress.

Ceramic Charcoal Stove in a Mixed Media

The acquisition of electric and gas stoves has been a difficult problem for most people in the rural places, hence most of them have resorted to wood for cooking. This has contributed to depletion of our forest and its attendant environmental consequences. This situation has made the researchers to attempts at looking for a way to reduce the amount of wood/charcoal used by designing a charcoal used by designs a chemical stove. This Ceramic Charcoal Stove was designed and built with locally obtained raw materials; locally composed low-density bricks and fired with a down-draught kiln at 800 degrees Celsius. The study also revealed that, once the charcoal in this stove is ignited, it could boil water at 6-7mins. This is a solution for conservation of charcoal used while cooking because some people are scared of using gas to cook because of its hazardous disadvantages while many others do not have money for refilling the gas cylinder and people who live in the rural area where there is no electric power supply, for electric stove. This solution has been found to have a high efficient heat maintenance property for cooking food and keeping the body warm is a welcomed development. This study is hoped to aid the in furtherance of academic research in this field and other related areas.

SIMULATION OF OPERATION OF THE AUTOMATED SYSTEM OF LOCAL MULTI-CIRCUIT COOLING OF PARTS OF AUTOTRACTOR DIESEL ENGINE

The results present the intermediate stage of the study of the thermal state of individual heat-stressed parts and units of a forced tractor diesel engine in the conditions of their local air cooling (LAC), which is regulated in automatic mode. Possibilities of practical implementation on the basis of microprocessor control systems of multi-circuit local cooling of parts of valve exhaust unit, bearing unit of turbocharger, if necessary, additional air cooling of the upper part of cylinder blocks in the area of cylinder liners are considered and evaluated. The listed parts, as evidenced by the results of many engine tests, differing in the values of the maximum critical temperatures, which in turn depend on the course of heat exchange processes in the corresponding interfaces, nodes. At the same time, in the conditions of operation with the use of the LAC system on the diesel engine there are additional problems associated with the complication of the cooling control algorithm, the need to move to multi-circuit options with their critical temperature values and required cooling air costs. At this stage of the study, a test was performed in the test mode of the algorithm for supply control and shutdown of the coolant supply, the corresponding circuit solutions for its implementation. In the engineless experiment, previously specially designed and thermocoupled units were used, which were heated separately with the set test temperatures, as well as a series-produced unit, which is part of the 4th generation gas cylinder equipment (GCE) of modern engines. The unit consists of four sections with solenoid valves, which dose the gas supply to the injectors according to a given algorithm (Valtek type 30). At the input of the engineless experiment, this unit was used to turn on and off the supply of compressed cooling air in separate circuits (from 2 to 4). The moments of operation of the valves (opening-closing) corresponded to the set test temperatures. In addition to the dynamics of temperature changes at the control points of the research units during the cooling process, the pressure, temperature, and coolant flow rates on individual circuits were also monitored. The conducted engineless experiment confirmed the correctness of the adopted circuit solutions, and also proves the possibility of further application of serial GCE units in LAC systems.