Ash Weight Research Articles

Enhancing the Durability Properties of Sustainable Geopolymer Concrete Using Recycled Coarse Aggregate and Ultrafine Slag at Ambient Curing

This study aimed at investigating the durability characteristics of the ambient-cured geopolymer concrete (GPC) developed using recycled coarse aggregate (RCA) and ultrafine slag (UFS). Two series of mixes were prepared. Natural aggregates (NAs) were replaced by RCA at different volume levels of 0, 25, 50 and 100% in both series. Meanwhile, UFS was added as a replacement by volume of fly ash at varying levels of 0, 15, and 30% in the first series, while UFS was used in addition to fly ash by percentage weight of fly ash at the levels of 0, 15, and 30% in the second series. The compressive strength, water absorption, chloride ion penetration, and carbonation depth of the developed ambient-cured GPC were studied. In addition, creep and drying shrinkage of the specimens were also examined. It was found that the compressive strength increased with the UFS content, while the opposite trend was observed with increasing RCA%. The highest compressive strength obtained with 100% RCA was 40.21 MPa (at 90 days), when 30% UFS was used in addition to fly ash. The addition of UFS not only helped in improving the strength characteristics but also provided an alternative to heat curing, which is a major drawback of GPC. Furthermore, the negative effects of RCA can also be minimised by adding UFS, which can be used as a compensator to RCA to improve the durability characteristics. The experimental results prove that susceptibility to chemical, water and chloride attacks can be mitigated by incorporation of UFS, and durable GPC can be produced by using RCA and UFS.

Effects of Nutrient Elements on Growth and Expression of Insect-Defense Response Genes in Zanthoxylum bungeanum Maxim

In China, Zanthoxylum bungeanum Maxim, known as “Huajiao,” has a pleasant, fragrant flavor and several therapeutic properties. The nutritional content of plants is necessary for their defense response to insects. In this study, we analyzed the effects of soil fertilization treatments such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and special compound fertilizer for pepper (HZ) on the different growth parameters and expression of insect-defense-response genes in Z. bungeanum. The results show that the height and weight of prickly ash significantly differed after the application of fertilizers with different concentrations. Additionally, seedlings that were treated with low concentrations of nutrient fertilizers (N1, P1, K1, Ca1, and HZ1) were significantly higher, and they were selected for transcriptome analysis. According to transcriptomic analysis, a total of 65,566 unigenes were discovered, among which 61,379 corresponded to annotated protein-coding genes and 4187 to transcripts of novel protein-coding genes. A total of 294 unigenes were detected as candidate genes for regulating the defense response to insects, including 204 protease inhibitors, 29 plant lectins, and 61 other defense response genes. Additionally, trypsin inhibitors, cystatin, phytepsin, metalloproteinase, MMP, caffeic acid, resveratrol, and thiol proteinase inhibitors, ACA, TDC, and 28 BES1 were enriched in Z. bungeanum. Specifically, the leaves of Z. bungeanum that were treated with Ca and HZ fertilizations were dominated by the protease inhibitors. In addition, the type of fertilizer significantly affects gene expression in plants. The functional annotations were predicted by the number of differentially expressed genes and classified by GO and KEGG ontology enrichment analysis. Moreover, according to the GO database, biological processes were the largest group and contained a high frequency of differentially expressed genes. According to KEGG pathway results, significantly enriched genes belonged to the biosynthesis of secondary metabolisms, amino acid metabolism, and folding, sorting, and degradation. Overall, it was found that the type of fertilizer with low concentrations had an effect on Z. bungeanum’s primary and secondary metabolism, and these findings provided grounds for further research in forest protection science.

Therapeutic Potential of Naringenin Nanosuspension: In Vitro and In Vivo Anti-Osteoporotic Studies.

Naringenin (NRG) is a flavonoid and has been reported as an anti-osteoporotic agent. However, poor bioavailability may limit the anti-osteoporotic potential of the drug. The purpose of the study was to compare the anti-osteoporotic activity of naringenin nanosuspension (NRG-NS) with the NRG and standard therapeutic drug, raloxifene hydrochloride (RLX). Here, NRG-NS showed anti-osteoporotic activity in MG-63 cells by upregulating the osteocalcin levels. The in vivo anti-osteoporotic activity of NRG-NS was further investigated in an osteoporotic rat model to mimic the post-menopausal condition. The animals were randomized and separated into six groups. The animals were treated with RLX (p.o., 5.4 mg/kg), NRG (p.o., 20 mg/kg), NRG-NS (p.o., 20 mg/kg), and blank-NS for 60 days after completion of a 30-day post-surgery period and compared with control and ovariectomized (OVX) groups. After the treatment, body and uterine weights, biochemical estimation in serum (calcium, phosphorus, acid phosphatase, alkaline phosphatase, osteocalcin), bone parameters (length, diameter, dry weight, density, ash weight, bone mineral content) and bone microarchitecture by histopathology were determined. The results showed the protective effects of NRG-NS on osteoblast-like MG-63 cells. The biochemical estimations confirmed the normalization of parameters viz., alkaline phosphatase, calcium concentrations, and bone density with a decrease in levels of acid phosphatase and inorganic phosphorus with NRG-NS as compared to plain NRG. The results indicated that the oral administration of NRG-NS could be a potential therapeutic formulation for the treatment of osteoporosis.

Study of the effects of drinking water treatment sludge on the properties of Class F fly ash-based geopolymer.

Drinking water treatment sludge (DWTS) generated from water treatment plants is a global issue because of the environmental risks it imposes. Managing the abundance of DWTS in landfills remains an important issue. The reuse of these sludges as a construction material could contribute to the development of a geopolymer and mitigate the harmful effects of the excessive production of these sludges on the environment. This study aims to evaluate the effect of DWTS on the properties of Class F fly ash (FFA) geopolymers. Seven geopolymer blends were made with the addition of DWTS in the total fly ash weight of 0%, 5%, 10%, 15%, 20%, 30%, and 40%, and with an alkaline solution composed of 12M sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solution; the liquid/solid and (Na2SiO3)/NaOH weight ratios were set to 0.75 and 2.5 respectively. The polymerization temperature was set at 60°C and different polymerization times such as 3, 7, 14, and 28days were considered. The bulk density, apparent porosity, compressive strength, and microstructure of the geopolymer samples were tested. The experimental results revealed that the optimum percentage of DWTS incorporation is 20 wt%, which generates a dense and homogeneous microstructure. The addition of more than 20% DWTS decreased the compressive strength from 40.87 to 35.3MPa and bulk density from 2.134 to 2.087g/cm3 due to the retention of air bubbles and evaporation of water during the polymerization process forming voids in the matrix, which results in increased apparent porosity from 19 to 22%. This investigation confirmed the feasibility of incorporating DWTS into FFA-based geopolymers.

Effect of Compaction Pressure and Sawdust Size on Briquette Made from Ulin Wood (Eusideroxylon Zwageri) and Gelam Wood (Melaleuca Cajuputi) to Combustion Characteristics

<p class="00textwithouttab">In Kalimantan, gelam (Melaleuca cajuputi) grows naturally in the swamp forest reaching 40 m with a diameter around 35 cm. Gelam wood is very resistant to acid soil in the swamp forest. Despite of it’s small diameter, gelam wood is very strong. This wood is usually used as the main house, as mold or mall support in casting concrete. Ulin (Eusideroxylon zwageri) is a typical plant of Kalimantan. In this study, the ignition duration, burning speed, and ash weight from briquette made from mixture of ulin and gelam sawdust was investigated. Size of sawdust used for briquette was varied for 40, 50, and 60 mesh while compaction pressure during briquette production was varied for 100, 125 and 150 kg/cm<sup>2</sup>. The study shows that the highest combustion temperature at 178 <sup>o</sup>C occurred for briquette with compaction pressure of 150 kg/cm<sup>2</sup>. Meanwhile, the lowest combustion temperature was obtained in briquette witch compaction pressure of 100 kg/cm<sup>2</sup>.</p>

Use of fixed calcium to phosphorus ratios in experimental diets may create bias in phytase efficacy responses in swine.

The objective of this study was to investigate the effects of two dietary total Ca/P ratios on available P release by phytase, measured using growth performance and bone mineralization with 528 barrows and gilts according to a randomized complete block design. Three were 11 diets in a factorial of 2 by 4 plus 3, including 3 reference diets consisting of 0.25% (control), 0.70%, or 1.15% monocalcium phosphate (MCP) and 8 diets from combining 4 phytase doses (500, 1,000, 2,000, and 3,000 FYT/kg) with 0.25% MCP and 2 dietary Ca/P ratios (1.05 and 1.20). Each diet was fed to 6 pens of 8 pigs. All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen on d 13–15 of trial. At the end of trial, one pig per pen was sacrificed to collect a tibia and urine in the bladder. The results showed that MCP improved growth performance linearly (P < 0.01), whereas both a linear and quadratic response was observed with the addition of phytase. The MCP increased the percent bone ash and weights of bone ash, Ca, and P linearly (P < 0.01). At both Ca/P ratios, increasing supplementation of phytase increased the percent bone ash and weights of bone ash, Ca, and P both linearly and quadratically (P < 0.05). Both MCP and phytase significantly increased digestibility of Ca and P as well as digestible Ca and P in diets and reduced the digestible Ca/P ratio. The dietary Ca/P ratio of 1.20 resulted in poorer feed utilization efficiency, more digestible Ca, greater percent bone ash, Ca, and P and heavier weights of bone Ca and P than the ratio of 1.05 (P < 0.05). The ratio of 1.20 elicited numerically higher available P release values from phytase, with percent bone ash and bone P weight as the response variables, but significantly lower values with gain:feed. The urinary concentration of Ca increased linearly (P < 0.01) with increasing digestible Ca/P ratios whilst urinary concentration of P decreased quadratically (P < 0.01). In conclusion, fixing the same total Ca/total P ratio in diets supplemented with increasing phytase dosing created an imbalance of digestible Ca and P, which could have an adverse effect on bone mineralization and thus compromise the phytase efficacy relative to mineral P.

The Effect of Municipal Solid Waste Incineration Ash on the Properties and Durability of Cement Concrete.

The aim of this study is to investigate the effect of municipal solid waste incineration bottom ash from a cogeneration plant on the physical and mechanical properties and durability of cement concrete. Part of the cement in concrete mixtures tested was replaced with 0%, 3%, 6%, 9%, and 12% by weight of municipal solid waste incineration bottom ash. Concrete modified with 6% of bottom ash had a higher density (2323 kg/m3), compressive strength at 28 days (36.1 MPa), ultrasonic pulse velocity (3980 m/s), and lower water absorption rate (3.93%). The tests revealed that frost resistance, determined in all-sided testing directions, of concrete modified with 6%, 9%, and 12% of bottom ash added by weight of cement corresponds to strength grade F100. Such concrete can be used in construction works.

Effects of graded levels of phytase supplementation on growth performance, plasma myo-inositol, tibia mineralization and nutrient digestibility of meat ducks fed phosphorus-deficient diets

Two experiments were conducted to explore the effect of reduction in dietary non-phytate phosphorus (nPP) and supplementation of an exogenous phytase on growth performance, plasma myo-inositol, tibia mineralization and nutrient digestibility of meat ducks. Exp. 1 used 450 one-day-old male Cherry Valley ducks over a 42-d period to evaluate growth performance and plasma myo-inositol. The treatments (6 replicates with 15 ducks per pen) included a positive control diet (PC, 4.0 and 9.0 or 3.5 and 8.0 g/kg of nPP and Ca in starter (d 0–21) and grower (d 21–42) period, respectively), a negative control diet (NC, 1.7 g/kg nPP and 1.9 g/kg Ca less from the PC), and the NC diet plus phytase at 1000, 2000 or 3000 FYT/kg feed. Exp. 2 used 600, seven-day-old, male Cherry Valley ducks in a 14-d trial to evaluate growth performance, tibia mineralization and nutrient digestibility. Dietary treatments (10 replicate cages with 10 ducks per cage) included a PC diet (4.0 and 9.0 g/kg of nPP and Ca, respectively), a NC diet (1.5 and 6.5 g/kg of nPP and Ca, respectively), and the NC diet plus phytase at 500, 1000, 2000 or 3000 FYT/kg feed. In Exp. 1, ducks fed the NC diet had lower (P < 0.05) weight gain (d 0–21 and 0–42), feed intake (d 0–21, 21–42 and 0–42) and body weight at d 21 and 42 compared to those fed the PC diet. There was no effect of diet (P > 0.05) on FCR or plasma myo-inositol. Phytase supplementation linearly increased (P < 0.05) weight gain, feed intake, and body weight; all parameters were equivalent to the PC at 2000 or 3000 FYT/kg. In Exp. 2, ducks fed the NC diet had lower (P < 0.05) weight gain, feed intake, body weight, tibia ash weight and percentage, and P digestibility and higher (P < 0.05) FCR and Ca digestibility compared to those fed the PC diet. Phytase supplementation improved growth measurements (linear and quadratic, P < 0.05), tibia ash weight and percentage (linear, P < 0.05) and P digestibility (linear, P < 0.05). Growth measurements and P digestibility were comparable to the PC level with supplemented phytase ranging from 1000 to 2000 FYT/kg, however, tibia ash weight and percent were below the PC, regardless of the dose of phytase. In conclusion, feeding graded concentrations of phytase improved growth performance, tibia mineralization, and P digestibility in ducks. Phytase supplementation at 2000 FYT/kg could fully restore the gain and P digestibility of ducks fed nPP deficient diets to that of a nutrient adequate PC. However, in extremely nPP deficient diets, tibia ash weight and percentage require a higher supplementation of phytase, which was beyond 3000 FYT/kg.

Measurement of 90Sr in Marine Biological Samples.

Strontium-90 (90Sr) is one of the most hazardous radionuclides, and it contributes to radiation exposure by ingestion. The routine determination of 90Sr in marine biological samples is highly desirable given the development of the nuclear power industry. A fast, simple, and low-detection-limit method was developed for the measurement of 90Sr in marine biological samples based on determining 90Y by means of coprecipitation and solvent extraction with bis-2-ethylhexyl-phosphoric acid (HDEHP) in n-heptane. The interfering 210Bi is removed using Bi2S3 precipitation. The separation and purification of eight samples per day can be accomplished through this method. The detection limit of 90Sr for this method is 0.10 Bq/kg (ash weight). The radiochemical procedure was validated by fitting the decay curve of the sample source and by the determination of 90Sr standards.

Investigation of the Liquefaction Potential of Coal Ash Due to Seismic Loading

Abstract Coal ash is a geomaterial with a metastable structure. This type of geomaterial is significantly susceptible to liquefaction as a result of seismic loads. An investigation of ash that is susceptible to liquefaction due to a seismic load can use the CPT penetration test. This method of investigating liquefaction was developed based on numerous penetration tests of sandy or silty–sandy soils and was developed at the Workshop on the Evaluation of Soil Liquefaction Resistance, NCEER, Salk Lake City, Utah, USA, 1996. In the present article, the results of the CPT penetration test conducted at the Rosina ash tailings pond in Žilina in Slovakia, are analyzed using the NCEER methodology. The safety factor for ash liquefaction was expressed based on the penetration resistance values measured in the CPT tests using the ‘LiquefyPro’ software. The safety factor in the liquefaction of the ash sediment was expressed by changing the level of seeping water in the body of the tailings pond, the unit weight of coal ash, and the seismic acceleration.

Ashing of bone: errors due to loss of CO2 and their correction.

Ashing is widely used to determine weight fraction of water-free bone that is mineral, but no standard procedure exists and the range of techniques used spans a range of temperatures and times over which the amount of weight loss is variable. We show that variability is largely due to progressive loss of CO2 from CO3 2- ions in the apatite crystal lattice, beginning at 600 ℃, typically used for ashing. We test the effect of varying temperature, time, and weight of sample and develop a reliable method, using small samples. Replicate samples of bovine cortical bone were tested at 500 ℃, 600 ℃, and 700 ℃ for times ranging up to 24h. We also tested samples of multiple humans at what we concluded to be the optimal conditions. Varying conditions of ashing resulted in variations in apparent ash weight % by up to 7%. Samples between 5 and 20mg heated to 600 ℃ for 1h gave results agreeing with generally accepted values, but with much smaller variability. Ash wt% values for multiple human bone samples differed by up to 4.8%, but replicate data for individuals agree to ± 1 wt%. In conclusion, a satisfactory method is given for ash weight determination using small samples, and yielding highly reproducible data. If accepted widely, ash weight values between laboratories could be used to study variations due to diet, age, drug treatment, and disease.

PROPERTIES OF CONCRETE UTILIZING SELF-CEMENTING HIGH-CALCIUM FLY ASH AS SOLE BINDER MATERIAL

Fly ash, a waste material derived from the coal burning in power plants, could be utilized in concrete mixtures as a filler or as a cement replacement material, either partially or fully. Some papers also report that high-calcium fly ash can be utilized as a cementitious material through the hydration process. However, there are just a few papers that studied the behavior of concrete that utilizes high-calcium fly ash as the sole binder material without any chemical activators. Furthermore, there are no reports about whether the effect of the different water-to-cementitious ratios of this concrete is the same as the ordinary Portland cement concrete. This paper presents an initial development on the use of fly ash as a sole binder material, i.e., 100% fly ash concrete without any chemical solution as an activator. This research utilizes the high calcium content in the fly ash to produce concrete with a commonly used method (just add the water without any alkali activator) and investigates how the water-to-cementitious ratio can influence the compressive strength of the paste and the concrete as well. The calcium content in the fly ash used in this study was in the range of 19–22 percent of the total weight of fly ash. Paste compressive strength of 66.78 MPa was obtained at 28 days with a very low water-to-cementitious ratio of 0.110.

Influence of Silica Fume on High-Calcium Fly Ash Expansion during Hydration.

The purpose of this work was to study the possibility of neutralizing high-calcium fly ash expansion during hydration. The object of the study was the fly ash of Berezovskaya GRES, which is capable of independent setting and hardening. The test in the Le Chatelier molds showed that the divergence of indicator arms was 90–100 mm 1 day after mixing with water. The expansion and cracking of the fly ash could be completely prevented by silica fume addition in an amount of 42.9% by weight of the fly ash. At the same time, the compressive strength of specimens from the fly ash–sand paste in a ratio of 1:5 at the age of 28 days was 1.47 MPa. The isothermal heat release at a temperature of 20 °C for 10 days reached 500 kJ/kg. XRF and DTA results showed that free lime in the fly ash was completely hydrated in 11 days and gave the greatest expansion in the absence of silica fume. The presence of silica fume made the lime hydration incomplete and decreased the expansion. Unslaked free lime remained in the system. Exothermic data showed that silica fume inhibited CaO hydration from the reaction start.

Age quadratically affects intestinal calcium and phosphorus transporter gene expression in broiler chickens.

This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.

Unit Weight of Foam Concrete Containing Blended Cement and Fly Ash

Abstract. The rapid development of construction and infrastructure results in increasing demands for natural resources continue. One of the many natural elements required for construction and infrastructure activities was cement, which is the basic ingredient in concrete. This study aims to analyze the unit weight of foam concrete containing blended cement and fly ash. The research approach used in this study was a laboratory experiment. Foam concrete was produced using 4 variations of cement (OPC, PCC-T, PCC-B and OPC+FA), fine aggregate, water and foam. The shape of the test object used was cube with a size of 15 cm × 15 cm × 15 cm. Unit weight test was used to evaluate the foam concrete mixture produced at the age of 3, 7, 28 and 730 days. The results showed that the unit weight of foam concrete in all variations of the specimens: OPC, PCC-T, PCC-B and OPC+FA, met the requirements for the unit weight of lightweight structural concrete based on SNI 03-3449-2002 and ACI 213R3 which was between 800 to 1400 kg/m3.

Modified zeolite from metakaolin and fly ash as efficient adsorbent for cationic methylene blue dye removal

Effective textile dye removal from aquatic wastewater is essential, as this effluent is harmful to human health, biodiversity, and natural environments. This study investigates the synthesis of zeolitic materials for dye removal from wastewater using metakaolin and fly ash as starting materials. In the first synthesis step, the starting materials are blended at various metakaolin-to-fly ash ratios and treated with a 3 M sodium hydroxide solution under stirring. The solid-to-liquid ratio of the precursor gel is 1:8 (w/v). The suspensions are then subjected to hydrothermal treatment at 120 °C for 6 h. In the second step, an impregnation method is used to obtain titanium dioxide (TiO2)-containing zeolite, and the effect of the TiO2 content on the zeolite adsorption performance is investigated. The synthesized products are characterized using X-ray diffraction, scanning electron microscopy, particle size analysis, surface area measurement, and ultraviolet-visible spectrophotometry. From the results, a metakaolin-to-fly ash weight ratio of 4:1 is optimal and yields sodalite and zeolite A. For 20-ppm methylene blue solution, the adsorption efficiencies of freshly synthesized zeolite and TiO2-containing zeolite are found to be 87.63% and 99.87%, respectively. In addition, the adsorption performance of the reused product is similar to that of the freshly synthesized product. Thus, the synthesized modified zeolite is an efficient adsorbent for methylene blue removal.

49 Determining the Phosphorus Release of Grainzyme Phytase in Diets for Nursery Pigs

Abstract A total of 360 pigs (Line 200 × 400, DNA, Columbus, NE, initially 9.9 ± 0.19 kg) were used in a 21-d growth study to determine the available P (aP) release curve for GraINzyme phytase (Agrivida Inc., Woburn, MA). Pigs were weaned at approximately 21-d of age, randomly allotted to pens based on initial body weight (BW) and fed common starter diets. From d 18 to 21 post-weaning, all pigs were fed a diet containing 0.11% aP. On d 21 post-weaning, considered d 0 of the study, pens were blocked by BW and randomly allotted to 1 of 8 dietary treatments with 5 pigs/pen and 9 pens/treatment. Dietary treatments were formulated to include increasing aP derived from either an inorganic P source (0.11, 0.19, or 0.27% from monocalcium P) or increasing phytase (150, 250, 500, 1,000, or 1,500 FTU/kg). Diets were corn-soybean meal-based and contained 1.24% standardized ileal digestible (SID) Lys. On d 21 of the trial, 1 pig/pen (weighing closest to the mean pen BW) was euthanized and the right fibula was collected to determine bone ash using the non-defatted processing method. Overall (d 0 to 21), pigs fed increasing aP from inorganic P or phytase had increased (linear, P &amp;lt; 0.002) ADG, ADFI, and G:F (quadratic, P &amp;lt; 0.05). Bone ash weight (g) and percentage bone ash increased (linear, P &amp;lt; 0.001) with increasing inorganic P or added phytase. The release equations developed for GraINzyme for ADG, G:F, bone ash weight, and percentage bone ash are: aP = (0.255 × FTU) ÷ (1,299.969 + FTU), aP = (0.233 × FTU) ÷ (1,236.428 + FTU), aP = (45,999.949 × FTU) ÷ (462,529,200 + FTU), and aP = (0.272 × FTU) ÷ (2,576.581 + FTU), respectively.

Influence of Different Addition Ratios of Fly Ash on Mechanical Properties of ADC10 Aluminum Matrix Composites

Aluminum-fly ash composites are formed by the chemical reaction between fly ash and the high-temperature aluminum-based alloy, which melts to form aluminum oxide as a reinforcing phase, which belongs to a composite of in situ synthetic reinforcing phases. Compared to aluminum-based alloys, composites have superior strength, rigidity, damping capacity, and wear resistance, but lower ductility and toughness. In this study, different fly ash addition ratios (0, 3, 6, 9, 12, and 15 wt%) were added to the ADC10-2Mg alloy melt via stir casting to form the aluminum-fly ash composite under the chemical reaction at 800 °C for 30 h. Subsequently, microstructure observation, density and porosity measurements, and hardness and tensile tests were conducted to analyze the influence of different fly ash weight percentages on the mechanical properties of aluminum-fly ash composites. According to the results, an aluminum-fly ash composite with good dispersibility of fly ash debris can be prepared by stir casting, and the fly ash particles gradually decomposed small debris as they reacted with the aluminum-based alloy at high temperatures during a long-term reaction process. The density of the aluminum–fly ash composite was reduced by adding fly ash, and its hardness and tensile strength were improved as well. However, the porosity increased with the amount of fly ash and the ductility was diminished. For the aluminum-fly ash composite with 6 wt% of fly ash, its density decreased by approximately 2%, the hardness and tensile strength increased by 7% and 49%, respectively, and the ductility decreased by 35%, as compared to those of the ADC10 alloy.

Thermal behavior and post-heating fracture characteristics of polypropylene microfiber-reinforced geopolymer binders

This paper investigated the post-heating behavior of fly ash-based geopolymer binders reinforced with polypropylene (PP) microfibers. Geopolymer binders with different fiber contents including 0%, 0.05%, 0.1%, and 0.2% by fly ash weight were prepared and exposed to elevated temperatures of 200 °C, 400 °C, and 600 °C. The effect of fiber reinforcement on the mechanical strengths of unheated binders, residual fracture characteristics of heat-damaged binders, microstructure deterioration, and thermal properties of geopolymer specimens were investigated. The results revealed that PP microfibers had neglected effect on the compressive strength of the binders, but clearly enhanced their flexural strength. Maximum enhancement of 17% was observed in the flexural strength of binders with 0.05% PP fibers. Using PP microfibers enhanced the residual compressive but not the flexural strength of the heat-damaged binders. The fiber-reinforced specimens had higher residual compressive strength compared to the corresponding fibreless ones when heated up to 500 °C. The modulus of elasticity and the toughness of the binders decreased with heating. Fiber-reinforced specimens showed higher reduction in the toughness but lower reduction in the modulus due to heating compared to the fibreless specimens. Using PP microfibers reduced the thermal conductivity of geopolymer binders. The reduction due to the fiber addition was less pronounced for heated specimens compared to unheated ones.

Effects of added phytase on growth performance, carcass traits, and tibia ash of broiler chickens fed diets with reduced amino acid, crude protein, and phosphorus concentration

This experiment was conducted to investigate the effect of phytase supplementation in diets reduced in amino acids ( AA ), crude protein ( CP ), and phosphorus ( P ) on growth performance, carcass traits, and tibia ash of broiler chickens. A total of 2,240 unsexed Ross 308 broiler chickens were used in 56 floor pens with 40 birds each and fed one of eight dietary treatments in seven replicates until 35 d of age. A positive control ( PC ) diet and diets with dietary AA/CP level reduced by 2, 4, and 6% were used with and without supplementation with 1,500 FTU phytase/kg. Starter, grower, and finisher diets were fed from d 1 to 10, d 10 to 25, and d 25 to 35, respectively. For the total period, no significant interaction effects between AA/CP level and phytase supplementation were detected for any measured traits. The ADG, ADFI, carcass weight, breast weight, and tibia ash weight were lower and FCR was higher compared to the PC diets when the AA/CP level was reduced by more than 2%. Phytase supplementation increased ADG, ADFI, final BW, and tibia ash weight. Tibia ash measurements showed that birds were adequately supplied with digestible phosphorus in all treatments, although dietary phosphorus and calcium were reduced in the phytase-supplemented diets. This enabled the feeding of broiler chickens without mineral phosphate supplements in grower and finisher diets. The results showed that supplementation with 1,500 FTU phytase/kg diminished the growth-decreasing effect of lower dietary AA/CP at all reduction steps.