Effect Of Compression Pressure Research Articles

Effects of compression pressure, biomass ratio and binder proportion on the calorific value and mechanical integrity of waste-based briquettes

Briquettes derived from organic waste offer a sustainable energy solution, yet those produced through the combination of palm kernel and decanter cakes remain inadequately researched. Hence, the impact of the proportion of biomass, compression pressure, and binder ratio on the calorific value and mechanical properties of the composite materials were investigated through response surface modelling. Under ideal circumstances, the utilization of bentonite clay and cardboard pulp binder resulted in a relaxation density maximum effect of 1527 kg/m3 and 1013 kg/m3, while yielding optimal calorific values of 24.22 MJ/kg and 29.09 MJ/kg correspondingly. The optimal shatter indices for both specimens were 104.5 % and 123.6 %, accompanied by water resistance capabilities of 99.7 % and 106.1 % correspondingly. Resistance to impact of cardboard pulp and bentonite clay binder were 772.9 % and 177.3 % respectively. The current study is the first to examine independent and dependent variables for these composite materials in sub-Saharan Africa using RSM.

The Effect of Compression Pressure on the First Layer Surface Roughness and Delamination of Metformin and Evogliptin Bilayer and Trilayer Tablets.

The objectives of this study were to evaluate the delamination of convex-shaped metformin HCl (MF) and evogliptin tartrate (EG) multi-layer tablets depending on the pre-compression and main compression pressures and simultaneously correlate these results with those of a surface roughness analysis. Free-flowing MF and EG (median diameters of 38.3 and 44.7 μm, respectively) granules prepared using the wet granulation method were pre-compressed and subsequently compressed into bilayer and trilayer tablets using a universal testing machine. The compaction force required to break the tablets increased linearly as the main compression pressure increased (30-150 MPa). Conversely, the interfacial strength and compaction breaking force decreased as the pre-compression pressure increased (10-110 MPa). A surface roughness analysis employing a profilometer revealed that the first layer (MF) roughness drastically decreased from 5.89 to 0.51 μm (Ra, arithmetic average of profile height deviations from the mean line) as the pre-compression pressure increased from 10 to 150 MPa in the bilayer tablet. Accordingly, the decrease in the roughness of the first layer reduced the inter-penetration at the interface, as observed via energy dispersive spectrometer (EDS)-equipped scanning electron microscopy, decreasing the interfacial bonding strength and causing delamination of the MF/EG multi-layer tablets. These findings indicate the significance of roughness control in the actual preparation of multi-layer tablets and the usefulness of profilometer- and EDS-based surface analyses for interpreting the delamination of multi-layer tablets.

(Digital Presentation) Effect of Compression Pressure on Water Removal and Power Generation Performance of PEFC with Modified Electrode/Channel Structure

Water flooding in cathode electrodes of polymer electrolyte fuel cells (PEFCs) is a critical issue that must be solved for achieving high efficiency and high power density operations. To alleviate this problem, it is necessary to design the optimum electrode/channel structure for actively removing liquid water from the porous media to the flow channel. In the previous studies, Okuhata et al. [1] revealed that the introduction of penetration holes to gas diffusion electrodes (GDEs) effectively promotes the water discharge and improves the limiting current density. Nishida et al. [2] investigated the effect of channel hydrophilization on the water behavior in the cathode of an operating cell using the cross-sectional visualization technique. It was found that the hydrophilization of cathode channels encourages the water suction from the gas diffusion layer (GDL) to the channel and enhances the oxygen diffusibility to the catalyst layer (CL). Our research group has proposed a novel hybrid electrode/channel structure combining the electrode perforation and channel hydrophilization and has investigated its effect on the improvements of water drainage and cell performance. In this study, we directly visualized the liquid water distribution in the cathode GDL of a customized PEFC with the hybrid electrode/channel structure using X-ray imaging and evaluated the transient response of cell voltage under the constant-current operations. Furthermore, the influence of compression pressure on the water behavior in the perforated GDL and the performance characteristics of the customized cell was also examined.For the X-ray investigation, we fabricated a specialized miniature fuel cell with the effective electrode area of 2.88 cm2. The membrane electrode assembly (MEA) was sandwiched between two carbon separators with a single-serpentine flow field (number of channels: 7, channel width: 1.0 mm, depth: 1.0 mm, total length: 88.5 mm). Fig. 1 shows a schematic cross-sectional view on the cathode side of the experimental cell. Since the cathode GDL is irradiated with X-ray beam in the in-plane direction, the through-plane distributions of water can be observed in the GDL under the 4th channel and under the land between the 3rd and 4th channel. To promote the water discharge from the fine porous media, a penetration groove (width: 300 μm, length: 11 mm) was installed into the GDL, MPL and CL and positioned along the right sidewall of the 4th channel. The channel walls on the cathode side were coated with the silica-based hydrophilic solvent. The contact angle of water on the hydrophilized channel is 9.8o. In the hybrid electrode/channel structure, liquid water accumulated in the CL and MPL is firstly discharged into the large groove in the in-plane direction. Subsequently, water droplets gathered in the groove are grown up and attached to the hydrophilized channel walls. The droplets are spread out on the hydrophilic sidewalls and the liquid films are moved upward. Fig. 2 presents the distributions of water saturation in the perforated GDL of the customized cell assembled under two different compression pressures of 0.5 and 1.0 MPa. The current density was increased stepwise from 0.14 to 1.02 A/cm2 for 8 min under the room temperature and non-humidification condition. All images were captured at t=8 min after starting the operation. Dry hydrogen (stoichiometry: 1.5@2.0A/cm2) and oxygen (stoichiometry: 3.0@2.0A/cm2) were supplied to the anode and cathode in the counter-flow arrangement. It was found that the introduction of the hybrid structure effectively decreases the water saturation around the groove due to the in-plane water discharge. The reduction of saturation under the land is much less than under the channel because the strong mechanical compression crushes the pore structure under the land regions and suppresses the water transport. In addition, the low-saturation region of 28% or less around the groove is enlarged with a decrease in compression pressure. The low compression pressure maintains the relatively large porosities in diffusion media and facilitates the water removal.

(Digital Presentation) Effect of Compression Pressure on Water Removal and Power Generation Performance of PEFC with Modified Electrode/Channel Structure

To prevent the water flooding in polymer electrolyte fuel cells (PEFCs), it is essential to investigate the water transport in cathode diffusion media of operating cells and design the optimum electrode/channel structure for encouraging the water discharge. Our research group has proposed a hybrid structure with the electrode perforation and channel hydrophilization. This study directly visualized the water distribution in the cathode gas diffusion layer (GDL) of a customized PEFC using X-ray radiography and characterized the cell performance under the constant-current operations. Furthermore, the influence of compression pressure on the water behavior in the perforated GDL and the performance characteristics of the customized cell was examined. It was found that the modified electrode/channel structure enhances the water discharge from the diffusion media and effectively reduces the water saturation around the penetration groove. The excessive mechanical compression of the customized cell suppresses the water removal through the diffusion media.

Effect on Compression Molding Parameters in Mechanical Properties of MWCNT/Glass Fiber/Epoxy Composites

Reinforcing fibers, nanofillers, matrix materials, and manufacturing techniques all have a role in the mechanical characteristics of hybrid composites. MWCNTs-reinforced E-glass/Kevlar/epoxy composites are appropriate fillers for structural applications. The impact of different concentrations of MWCNT fillers (0.4%, 0.8%, and 1.2% wt) on the mechanical characteristics of hybrid composites has been studied. Tensile and bending strength, as well as hardness, were measured in compression-molded composites. The effects of compression pressure, mold temperature, and applied pressure on hybrid (0.8% MWCNT) were investigated. When it came to composite tensile and bending strength, compression pressure was the most important factor, closely succeeded by mold temperature and pressure period. Compression molding were optimized, resulting in a tensile strength of 183 MPa, a bending strength of 158.3 MPa, and a hardness value of 23.8 HV.

The Effects of Compression Pressure on Injection Compression Molding

Abstract Injection compression molding incorporates a mold compression action in the postfilling stage to compact the materials. The process is the same as the conventional injection molding in the filling and first stage packing. Packing stage continues until the gate material is frozen or the gate is shut off. Then, a mold compression action is engaged and continues to the end of the molding. With the mold compression, the pressure distribution inside the mold cavity can be uniform and the residual stresses caused by pressure gradients can be minimized. However, due to the non-isothermal cooling process, the compressibility of each place inside the mold cavity was not the same. At some time of the cooling process, the pressure at different points began to deviate from each other. In order to improve the non-uniform compression at later the stage of a ICM process, a two-stage compression method can be used. A disk mold was designed to study the effects of the two-stage compression on the molding product. It was found that less warpage can be obtained with a lower compression force at the second stage. The experimental results also suggested that there existed an optimal compression time that was corresponding to the time before the material solidification.

Compression Garments for Recovery from Muscle Damage: Evidence and Implications of Dose Responses.

The use of compression garments (CG) has been associated with improved recovery following exercise-induced muscle damage. The mechanisms responsible are not well established, and no consensus exists regarding the effects of compression pressure (i.e., the "dose"), which until recently was seldom reported. With the increasing prevalence of studies reporting directly measured pressures, the present review aims to consolidate current evidence on optimal pressures for recovery from exercise-induced muscle damage. In addition, recent findings suggesting that custom-fitted garments provide greater precision and experimental control are discussed. Finally, biochemical data from human trials are presented to support a theoretical mechanism by which CG enhance recovery, with recommendations for future research. The effects of compression on adaptation remain unexplored. More studies are required to investigate the relationship between compression pressure and the recovery of performance and physiological outcomes. Furthermore, improved mechanistic understanding may help elucidate the optimal conditions by which CG enhance recovery.

ANALISIS KARAKTERISTIK BRIKET ARANG DENGAN VARIASI TEKANAN KEMPA PEMBRIKETAN

Biomass is often considered as a material that is lacking or even uneconomical. Biomass that is abundantly available in Indonesia is sawdust and coconut shell waste. This number has not been used maximally, this is because both wastes tend to be disposed of directly into the environment and can cause environmental pollution. Briquetting technology is one of method which can be implemented to increase the added value by producing briquettes. Many factors affect the quality of briquettes, one of which is the pressure of the briquette press. The pressure of the briquette press affects the durability and cohesiveness of briquettes. The aim of this research was to specify the effect of compression pressure on calorific value, ash content, and water content of briquettes. The research was conducted by varying the briquetting compression pressure, namely 1500 psi, 2000 psi, and 3000 psi. It has been done by several main stages, namely the carbonization process, the manufacture of charcoal briquettes, and test analysis. Charcoal briquettes have an average heating value of 6386.377 cal/g, 1.136% moisture content, and 6.659% ash content at a compression pressure of 1500 psi. At a compression pressure of 2000 psi, charcoal briquettes have an average heating value of 6672.601 cal/g, 1.110% moisture content, and 5.419% ash content. Meanwhile, at the compression pressure of 3000 psi charcoal briquettes have an average heating value of 6685.144 cal/g, 1.288% water content, and 6.627% ash content. Charcoal briquettes produced by varying the pressure of the briquetting press have met the quality standard of SNI 01-6235-2000 briquettes. The most optimum compression pressure for charcoal briquetting obtained in this study was 2000 psi.

Static Compression and Dynamic Sliding Conditions of 2D Trapezoid Square and Circle Contact Surface Shapes

In addition to force-body interaction problems, deformable bodies problems are quite common in engineering applications and their investigations are more complex. The friction force and contact pressure formed between the surfaces are dominant and mostly studies are investigated considering the static and quasi-static conditions. However, considering the elastic/elasto-plastic deformation and dynamic conditions, the geometric surface shape is important. In this study, using the finite element analysis method, the pressure distribution of the surfaces containing square, trapezoidal and circular surface shapes on a flat surface and the dynamic deceleration condition during the surface interaction of an object with initial velocity are investigated. The material used is steel whose ground geometry does not show linear behaviour and nylon material is used for surface geometry. In order to ensure that the surface effect is dominant in the dynamic examination, a linear increasing pressure is applied on the examined part. In the results, it was determined that there is an irregularity in the stress and velocity deceleration curve. The effect of compression pressure and friction coefficient has been examined in detail and the results are discussed.

Effect of Compression Pressure and Coal Binding on the Fuel Properties of Biomass Pellet

Effect of Compression Pressure and Coal Binding on the Fuel Properties of Biomass Pellet

Effect of Compression Pressure on Combustion of Tapes Obtained by Rolling a Ti + 1.7B Powder Mixture

Effect of Compression Pressure on Combustion of Tapes Obtained by Rolling a Ti + 1.7B Powder Mixture

Experimental investigation and optimization of compression moulding parameters for MWCNT/glass/kevlar/epoxy composites on mechanical and tribological properties

The mechanical properties of hybrid composites are largely influenced by the reinforcing fibres, nanofillers, matrix materials and fabrication methods. Multi-wall carbon nanotubes (MWCNTs) fillers reinforced to E-glass/Kevlar/epoxy composites (GKEC) are best suited for structural applications. The present study investigates the effect of adding different amounts of MWCNTs fillers (0.3%, 0.6%, and 0.9% wt) to hybrid neat (E-glass, Kevlar, epoxy) composites on the mechanical properties. Strength (tensile and bending) and hardness properties of the developed composites fabricated using compression moulding technique were evaluated. The effect of compression pressure, mould temperature and the time duration of applied pressure on hybrid (0.6MWCNT-GKEC) were also investigated. The compression pressure had the maximum effect on the tensile and bending strength of the composite, followed by mould temperature and pressure duration. The optimized compression moulding conditions resulted in 181.2 MPa of tensile strength, 143.3 MPa of bending strength and 22.8 HV. The wear rate of hybrid composites is less than that found in neat GKEC composites and showed fewer wear debris, which indicate their exists a smooth surface on worn surface morphologies.

Effect of compression pressure on strength of low-temperature sinter bonding produced using silver formate

ABSTRACT Novel pressure-assisted sinter bonding at 200°C using silver (Ag) formate particles was performed in air using an Ag-finished die and substrate to achieve a reliable Ag bondline even at high temperatures. The Ag formate particles, prepared by immersing Ag2O particles for 3 min in a formic acid solution, indicated a pyrolysis reaction near 130°C, forming pure Ag and gases (carbon dioxide and hydrogen). With a paste prepared by mixing the Ag formate particles with α-terpineol, the bonding under 10 MPa exhibited an adequate shear strength of 270 MPa after 3 min. Moreover, a near-full-density structure was observed in the formed bondline after 10 min. Consequently, the compression pressure of 10 MPa resulted in significantly enhanced bondability with reduced void fraction in the formed Ag bondline.

Recovering Wood Waste to Produce Briquettes Enriched with Commercial Kraft Lignin

Aiming to use lignocellulosic biomass as energy source, one of the process that may aggregate values is the densification process, which allows the production of bioenergy using solid fuels, mainly for reducing transportation costs. In this research, solid fuel from co-briquetting of wood residues from sawmill using commercial kraft lignin as binder was investigated. The effects of compression pressure (900, 1200 and 1500 PSI) and briquette formulation (varying wood and kraft lignin proportion) on the quality and characteristics of briquettes were evaluated. The main findings were that briquetting of wood residues with kraft lignin resulted in an improvement of bulk density, strength rupture modulus, low heating value (LHV) and high heating value (HHV). The briquettes using 4% and 6% of kraft lignin, and submitted to 1200 to 1500 PSI, presented higher bulk density and strength resistance, respectively. On the other hand, the heating values showed the highest results with the addition of 2% lignin at 900 PSI, being the legal range for additives in briquettes for many countries such as in European Union.

Effect of Compression Pressure on Combustion of Tapes Obtained by Rolling a Ti + 1.7B Powder Mixture

Effect of Compression Pressure on Combustion of Tapes Obtained by Rolling a Ti + 1.7B Powder Mixture

Gamma-Ray Attenuation Study for the Soils of Bursa, Turkey, in the Energy Range 59.5–1332.5 keV

In this study, the gamma radiation attenuation was experimentally investigated for soil samples with different texture collected from Bursa Province, Turkey. Firstly, physical and chemical properties (e.g., density, particle size distribution, lime content, organic matter and chemical composition) of these soils were determined by several methods. The transmission measurements of soils performed by using Am-241, Cs-137, Co-60 and Na-22 sources and 2 × 2 inch NaI(Tl) scintillation detector were used to calculate shielding parameters, mass attenuation coefficient, half value layer and tenth value layer values, of these samples in form of pressed powder pellets. The values of these important parameters have been found to vary with gamma-ray energy and chemical composition of the studied soil samples. For instance, the mass attenuation coefficients were decreased with increasing gamma-ray energies and, with the increase in contribution of MgO and Na components, caused better absorption. The effect of compression pressure on attenuation coefficient was also investigated, and better absorption was observed for the sample pressed by high value of press force.

Fabrication of highly filled wood plastic composite pallets with extrusion‐compression molding technique

AbstractThe aim of this study was to fabricate highly filled wood plastic composite pallets with extrusion‐compression molding technique and investigate the effects of processing parameters on mechanical performance and production stability. The composites were blended in twin‐screw extruder and subsequently measured by weight with an electronic scale. Before compression, it was divided into pieces and rearranged in the cavities of compression mould according to the mass distribution. The effects of compression pressure and mould temperature on flexure strength, density, water absorption, and dimensional deviation were investigated. The results show that both the flexure strength and density of the pallets increased with compression pressure and remained higher than that of extruded deck when compression pressure exceeded 6.5 MPa. Water absorption and dimensional deviation decreased with compression pressure and remained lower than that of extruded deck after the compression pressure exceeded 6.0 MPa. Compression pressure could increase the final passed yield by improving the composite melt filling state and lowering the buckling deformation, but further increase above 6.7 MPa would result in a decline in final passed yield. Increase in mould temperature contributed to the production stability but an excessive value would extend the molding cycle. The insights gained from this study may be of assistance in optimizing extrusion‐compression processing parameters and expanding the application of highly filled wood plastic composites in complicated and irregular products.

Relationship between compression pressure, mechanical strength and release properties of tablets.

Tablets are a complex drug delivery system consisting of the active pharmaceutical ingredients and excipients. Tablet production involves a series of unit operations in which drugs and excipients are subjected to mechanical stresses, such as compression pressure, thus imposing changes in the properties of these materials. Variations in the compression pressure and other processing parameters may affect the mechanical strength and release properties of the final tablet. It is generally expected that an increase in compression pressure should lead to an increase in mechanical strength and a decrease in release properties of tablets, but this may not be true in some practical situation, since tablet production is the result of complex interaction between many factors involving the drug, excipient, the formulation, and processing variables. The degree and extent of interaction of these variables are not absolutely dependent on one factor. The aim of this review is to study the interaction between compression pressure, mechanical strength and release properties of immediate and controlled release tablets. The effect of compression pressure on tablets is complemented by such factors as the material properties of the drug and excipient, the formulation and processing factors, which in turn affects mechanical strength and release properties.

Solid fuel from Co-briquetting of sugarcane bagasse and rice bran

Solid fuel from co-briquetting of SCB and RB was investigated in this study. The effects of compression pressure (8, 10 and 12 MPa) and briquette formulation (varying SCB-RB fractions, 0–1 w/w) on the quality and characteristics of briquettes were determined under fixed compression temperature (150 °C), time (30 min), and rate (0.34 MPa/s). Effects of initial biomass composition on the mechanical properties, fuel characteristics and quality of the briquettes produced were also studied. Briquetting of SCB and RB resulted in an improvement of the bulk density up to 1.1939 g/cm3 (corresponding to a compressive strength of at least 5.12 kgf/mm2) and in the reduction of the equilibrium moisture to as low as <5 %w/w. Moreover, the physical and chemical characteristics of SCB and RB were found to have significant influence on the quality and characteristics of the briquettes produced, with its inherent structure and components improving briquette strength and serving as natural binders, respectively. Mechanical densification didn't result in changes in the combustion characteristics of the residues as fuel, further improvement may be required if used in existing industrial boilers and burners. Nevertheless, the briquettes produced using SCB and RB meet current standards for fuels intended for domestic use.

Flexural Strength and Thermal Conductivity of Fiber-Reinforced Calcium Silicate Boards Prepared from Fly Ash

AbstractA novel fiber-reinforced calcium silicate board was prepared from fly ash. The effects of compression pressure, pulp fiber content, and cement content on the flexural strength and thermal c...