Acoustic Attenuation Performance of Two-Pass Perforated Hybrid Mufflers with Mean Flow

The one-dimensional (1-D) analytical approach is developed to predict and analyze the acoustic attenuation performance of two-pass perforated hybrid mufflers in the presence of mean flow. The expressions of complex acoustic wavenumber and impedance of long fiber glass wool are presented by using the impedance tube measurement and curve fitting. The 1-D approaches as well as the fitting expressions are validated by comparing the predicted and measured transmission loss of two-pass perforated hybrid mufflers with a different Mach number. Results illustrate that the 1-D predictions agree well with measurements below the plane wave cut-off frequency and deviate in higher frequency range. The influences of geometric parameters including the lengths of extended tubes, perforations on the right bulkhead and the outlet tube, and mean flow on the acoustic attenuation behavior of the hybrid mufflers are examined.

Effect of Variations in Pyrolysis Reactor With Glass Wool Equipped and Without Glass Wool on the Weight of the Oil Produced

Currently, plastic waste is a very serious threat because plastic waste pollution can harm all living things around and also harm the environment. The increasing volume of plastic waste is due to the lack of processing technology, so that the volume of plastic waste is increasing day by day. Plastic is a material that is difficult to decompose because it is non-biodegradable. One application of plastic waste processing technology offered in this study is to use the pyrolysis principle. Pyrolysis is a method of converting plastic into fuel oil through a thermal decomposition process without the use of oxygen. The pyrolysis process used with a variety of reactors equipped with glass wool and reactor variations without glass wool. The purpose of this study was to compare the yield of pyrolysis oil with a variety of reactors equipped with glass wool and reactors without glass wool. The plastic used is OPP (oriented polypropylene), with a constant reactor heating temperature of 200° C. The pyrolysis process is carried out for 1 hour each test, and the condenser cooling temperature is 28° C. Based on the results of the research, the reactor variation with glass wool got the highest oil weight of 175 grf, while the reactor variation without glass wool got the lowest oil weight of 17 grf. With a variety of reactors equipped with glass wool, the heat generated is more concentrated into the reactor core, resulting in higher oil weight and a more efficient pyrolysis process.

Hygrothermal performance of the building envelope with low environmental impact: case of a hemp concrete envelope

This document is a case study of hemp-based materials integrated into the building envelope for African and North American’s applications. The objective is to evaluate the energy performance of hemp concrete for construction in Montreal, Canada, where heating predominates and in Dori, Burkina Faso, where air conditioning predominates. The effect of thermal and hygrothermal comfort of hemp concrete, glass wool, cement block and compressed earth brick walls were simulated to quantify the benefits on overheating during the hottest months for the city of Dori and the risk of mould growth in the walls of the building in winter for the city of Montreal.

Study on Fire Resistance of Floor Structures in High-speed Train

According to the standard EN 45545, fire resistant tests of floor structures in high-speed train were carried out. Two typical floor structures which were placed in the passenger train were tested. Integrity and insulation are main performance criteria to evaluate fire resistance of floor structures. The furnace temperature is in accordance with the requirements in the standard ISO 834. The surface temperature and deflection were recorded with time. Glass wool and aluminium corrugated sandwich structure in two structures were burned through. The experiments were terminated at 30 minutes and 31 minutes respectively for the two structures. A large amount of smoke and the sound of cracking of the exposed surface of the test piece were produced, although the unexposed surface of test pieces did not reach the failure condition.

New circular building composite material to upcycle building wastes

A new class of sustainable building composite materials is developed, made out of recycled fibers waste, of sand from crushing inert waste and of lime. The fibers come from abundant and available bio-based or mineral fibers such as cellulose, glass wool, or rock wool. The crushing sand comes from inert building waste and is used instead of river sand which is a resource under shortage. Lime is, like the other two constituents, available locally. The targeted performance is minimizing the environmental footprint compared to the current building materials available on the market in terms of CO2 emissions and grey energy consumption over the entire life cycle. Additional specific objectives are a lifetime up to 60 years, the incorporation of at least 75% recycled or end-of-cycle materials and a high potential of further reuse or recycling. These performances must be optimized under all the structural, thermal and durability constraints of specific building applications. A test campaign has proved the energy-efficient nature of the processing and excellent potential in terms of insulation, fire resistance and mechanical strength, for materials containing a rate of paper fibers larger than 50%.

Performance evaluation of glass wool core VIPs and silica-fly ash core VIPs

Temperature maintenance is one of the leading factors for the large-scale energy consumption in buildings, which accounts for 33% of the total consumption. The heavy smog in China resulting from the depletion of fossil fuels necessitates the development of new technologies that can reduce the energy usage in buildings. Several techniques for building’s thermal insulation were developed among which the utilization of Vacuum Insulation Panels (VIPs) has the leading edge. For refrigeration purpose in VIPs, the glass wool is being used as a core material because of their low thermal conductivity (λ ≤ 2 mW/m·K) and low cost. However, the silica-fly ash has been preferred as a core material of VIPs for buildings because of its high compressive strength (σc > 2 MPa) and the most economical price. Moreover, the P1/2 of the glass wool VIP and silica-fly ash VIP are 10–100 and 1000 Pa, respectively. In this work, the performance of VIPs with various cores has been compared. The thermal conductivity of VIPs, along with the factors affecting thermal conductivity, such as density, thickness, internal pressure, and porous structures, have been evaluated. In addition, the effect of core materials on the cost of VIPs was also quantified. It is expected that the study will serve as a pioneering work in the foundation to development of the next-generation, low-cost VIPs used for building insulations.

Beneficial Role of Platelet –Rich Plasma (PRP) combined with Glass Wool Filtration for Best Recovery of Spermatozoa in Infertile Men

Background: Platelet –Rich Plasma (PRP) is a novel therapeutic agent used in multiple medical fields and one of these fields is the reproduction for best spermatozoa preparation and activation for upgrading activity and motility of the spermatozoa and filtered with glass wool filtration to eliminate any round cells and leukocytes from the sample. Objectives: The aim of this research is to study some sperm characteristics in two groups, the normozoospermic infertile men and th asthenozoospermic infertile group before and after activation with Glass wool Filtration and PRP and compare between both. Patients and Methods: In this study 60 infertile men were enrolled and divided into 2 groups,15 normozoospermic infertile men, and 45 ashenozoospermic infertile men during their attendance to the Infertility Clinic in High Institute for Infertility Diagnosis and Assisted Reproductive Technologies Al-Nahrain University. The collected semen samples, and seminal fluid analysis were assessed, each semen sample was divided into 3 tubes and labelled as the 1st tube which was before activation, the 2nd tube was after glass wool filtration activation technique and the 3rd tube was for semen activated by adding PRP to the medium used for glass wool filtration activation. Results: Both techniques showed increased and improved sperm motility, but the PRP was superior to the glass wool alone in upgrading Sperm Grade A Motility %, Sperm Grade B Motility % and decreasing Sperm Grade C Motility %, and Sperm Grade D Motility (Immotile Sperm). Conclusion: The PRP was significantly effective in improving the sperm activity and upgrading sperm motility more than Glass Wool Filtration technique.

Foamed Geopolymer Composites with the Addition of Glass Wool Waste

This study examines foamed geopolymer composites based on fly ash from the Skawina coal-fired power plant in Poland. The paper presents the effect of adding 3% and 5% by weight of glass wool waste on selected properties of foamed geopolymers. The scope of the tests carried out included density measurements, compressive and bending strength tests, measurements of the heat conduction coefficient, and the results of measurements of changes in thermal radiation in samples subjected to a temperature of 800 °C. The obtained results indicate that glass wool waste can be successfully used to lower the density and heat conduction coefficient of foamed geopolymer composites with a fly ash matrix. In addition, the results of changes in thermal radiation in the samples subjected to the temperature of 800 °C showed a positive effect of the addition of glass wool waste. Moreover, the introduction of the addition of glass wool waste made it possible to increase the compressive strength of the examined foamed geopolymers. For the material modified with 3% by weight of mineral wool, the increase in compressive strength was about 10%, and the increase in fibers in the amount of 5% by weight resulted in an increase of 20% concerning the base material. The obtained results seem promising for future applications. Such materials can be used in technical constructions as thermal insulation materials.