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Nanocomposites based on polypropylene/wood fiber (PP/WF 70/30) compound containing 2.5 to 10 phc of nano-CaCO3 and 5 phc of maleated polypropylene (MAPP) as compatibilizer were prepared by melt compounding followed by injection molding. The mechanical properties, thermal behavior as well as water absorption were characterized and the morphology was studied using scanning electron microscopy. The presence of nano-CaCO3 declined the amount of water absorption as high as 60 wt%. The incorporation of nano-CaCO3 into PP/WF compounds led to the 12% increment of flexural modulus, 22.5% rise in impact strength, and 9% increase in elongation at break. The results of DSC experiments indicated that the addition of nano-CaCO3 can elevate the crystallization temperature and reduce the degree of crystallinity of PP in PP/WF/CaCO3 nanocomposites. The maximum values of crystallinity, flexural modulus and flexural strength were achieved at 5 phc loading of nano-CaCO3, and the maximum crystallization temperature and impact strength were attained by adding 7.5 phc of nano-CaCO3. The reduction of tensile strength, as high as 8.8%, in PP/WF/CaCO3 nanocomposites was attributed to the decrease of PP crystallinity, as well as the presence of nano-CaCO3 at the PP/WF interface.

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influenced by temperature. On the other hands, the existing of carbonate as one of the major components of clayey soils in arid and semi-arid lands, and its effect on engineering properties of the soils prove the necessity to study the simultaneous influence of carbonate and temperature on the engineering behavior of clayey soils. In the present work, the interaction between clay and carbonate in high temperatures has been investigated. Bentonite were mixed with different percentages of carbonate and sand. The variations of added carbonate were 0% (natural carbonate content), 10%, 20%, and 30%, respectively, and added sand were 20% and 40%. The soil samples were carefully mixed with enough water to bring them to their plastic limit and were kept in plastic bag for uniform-moisture distribution for a period of 24 h. It was then sieved through a #10 mesh to ensure to achieve a uniform mixture. Samples for testing were then prepared by compacting soil mixtures into cylinder mold in three layers. The test specimen dimensions were 35 mm in diameter and 70 mm in height. The clay specimens were allowed to air dry at room temperature for 24 h. Bentonite specimens were kept in plastic bag to prevent development of cracks during air drying due to high crack potential. The samples were then oven dried at 110 °C for a period of 24 h. The test specimens were heated to temperatures of 300, 500, 700, 900 and 1100 °C, using programmable Carbolite electric furnace. The specimens were placed in the electric furnace at room temperature and then the temperature was increased at a rate of 3 °C/min until the desired temperature was reached. Once the treatment temperature was reached, it was held at that stage for 2 h, then the furnace was turned off. The specimens were then allowed to cool overnight in the closed furnace. After this curing condition, samples with different levels of temperature including 25 °C (laboratory temperature), 110, 300, 500, 700, 900 and 1100 °C were used for experiments. The changes of physical and engineering properties of the soil were studied by performing macro-structural tests such as linear shrinkage, water absorption and unconfined compression. The results show that as temperature increases close to the de-hydroxylation temperature, strength gradually increases. At de-hydroxylation temperature, the strength significantly increases, so that the strength of bentonite specimens increases 3 to 4 times. The strength of bentonite specimens significantly decreased with increasing the heat over de-hydroxylation temperature. This strength reduction was due to the formation of microscopic voids and pores in the specimen. Analyzing the simultaneous influence of carbonate percentage and heating indicate that the increase of carbonate percentage in a given temperature results in the decrease of strength and the amount of this reduction is different in different temperatures. In bentonite specimens, heating causes the water absorption to be decreased, however, the increase of carbonate percentage results in the increase of water absorption in a given temperature. Temperature, Bentonite, Calcium carbonate, water absorption, Unconfined compressive strength.

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In this paper, we investigate the effect of nano-CaCO3 on water absorption and tribological properties of polyamide-6. To this end, nanocomposites based on polyamide-6 blend, containing 1 to 5 phr of nano-CaCO3, and 1 phr of maleated polyamide (PA-g-MAH) as compatibilizer, are prepared via melt compounding followed by injection molding. The wear testing of each of the prototypes is carried out under identical conditions. Then, the morphology is studied using scanning electron microscopy. The addition of nano-CaCO3 particles with compatibilizer increases the wear resistance and reduces the water absorption. The results of experiments indicate that minimum wear rate is achieved by adding 1 phr of nano-CaCO3 with compatibilizer which is nearly 4 times less than pure PA6. Furthermore, the presence of nano-CaCO3 together with PA-g-MAH lowers the amount of water absorption as high as 32% wt in compare to pure PA6. In addition to these, this fact is also emerged that effect of compatibilizer is prominent on uniform distribution of the nano-CaCO3 particles among polyamide matrix that it leads to improve the tribological properties of the nanocomposite prototypes in the wear test.

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Drict discharge of domestic wastewater(sewage) to the environment or into absorbing wells has caused many problems including surface and groundwater pollution. To reduce such problems, the number of wastewater treatment plants has increased significantly in Iran during the last two decades. During wastewater treatment, a significant amount of sludge, composed of organic and mineral material, is produced. This sludge, if not handled and disposed properly, can create serious environmental and health issues. One environmentally attractive way of dealing with such wastes is to use them in different types of applications. In this regard, many economical and beneficial methods have been developed to reuse sludge. Incineration of sludge for energy recovery or the use of sludge ash in cement-based construction materials are among these methods. Sludge incineration produces considerable amount of ash which should be disposed. However the ash can be used as cement substitude in procuction of cement-based material. The subject of using sludge ash as cement substitude has been investigated by a few researcher with the conclusion that the usage of ash can affect the final cement-based product quality. Based on their experimental results, the use of sludge ash tends to decrease the compressive strength of mortar or concrete. However, it should be mentioned that no research has yet been done to investigatethe the effects of sludge ash replacement on mechanical and durability properties of concrete. The main aim of this study was to investigate the effects of sludge ash usage as cement substitude on physical, mechanical and durability properties of concrete. For this purpose, the effects of three key parameters: replacement level ( 0-20%, by weight), curing times (7, 28, 91 and 180 days) and water-cementitious material ratio (0.35, 0.45 and 0.55) were investigated. The sludge used in this research was obtained from one of the local wastewater treatment plants, which subsequently was dried and then was incinerated at 800oC to produce ash, The ash was in general, made up of irregular grains which were aggregates of smaller particles. Also, the ash was composed mainly of calcium, silica and aluminium oxides. The results showed that increasing the amount of sludge ash induced higher mortar setting times as compared to the control samples, using Vicat test. The effect of ash content on mechanical properties of concrete samples was carried out by compressive strength tests. Results indicated that for 7 and 28 days curing time, concrete samples containing a mixture of sludge ash and cement yielded lower compressive strength values than those samples using only cement (without any ash content). However, for curing times greater than 28 days, the increase in ash content of concrete samples (0-15% by weight) led to an increase in compressive strength. Water absorption and electrical resistivity tests were conducted to determine the durability of concrete containing sewage sludge ash. As blending percentages of ash content increased fom 5% to 20%, electrical resistivity of concrete samples decreased for regardless of the applied curing times. This phenomenon might be the result of increased porosity and material ionization.

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Increasing builders waste of autoclaved aerated concrete (AAC) require new concepts for future recovery processes. There are two main aspects, underlining this basic necessity for developing AAC recycling models. Environment protection ranks first because of the risk of groundwater pollution by compounds leached out from AAC waste during its deposition. The second aspect is raw materials preserving because of the high content of the valuable potential recyclable calcium- silicate-hydrate phase 11 Å tobermorite (5CaO 6SiO2 5H2O) besides pure quartz and minor aluminate. In general the main constituents of AAC amount around 40–50 wt-% for tobermorite and approx. 30–40 wt-% for quartz. The tobermorite phase is causing the AAC strength and forms hydrothermally at 180–200 °C and 10–12 bar pressure during autoclaving from the raw materials lime, quartz, and water. Minor parts of aluminum powder for pore-forming and small amounts of cement and anhydrite for better handling of the AAC-green bodies are the further additives of the AAC raw materials mixture. The high silicate content, as well as the valuable calcium parts, display AAC waste as an interesting raw material for zeolite formation as known from the treatment of fly ashes and slags. According to their outstanding properties zeolites are used in sorption techniques, catalysis, molecular sieving, and ion exchange processes, and in previous studies, we already could show zeolite hydro sodalite formation beside hydrogarnet and other valuable calcium- and sodium aluminosilicates applying NaAlO2 as an aluminum source in the reaction mixture. Those previous syntheses were performed in water and under low alkaline (1 m NaOH) and low acid (1 m citric acid) conditions. This mild reaction milieu was found to be responsible for relatively low AAC conversion rates and the formation of multiphase products. In reference, the aluminum source NaAlO2 was added to the AAC always before the leaching reactions were performed. In contrast, the presented study investigates leaching of pure AAC in stronger alkaline media of 4–8 m NaOH and the combination with acid treatment, before the aluminate is added for the final crystallization process. This procedure is expected to be much more effective to synthesize uniform zeolite products at 100% AAC conversion rates, as shown in the following experimental study. Autoclaved Aerated Concrete (AAC) used in low-rise buildings and infilled frames as a structural member. One of the weaknesses of AAC is low mechanical strength. In addition, AAC blocks absorb water of mortar which can lead to executive problems. In this paper, the effect of silica fume, zeolite and granulated blast furnace slag (7%, 14% and 21% by weight of cement) was investigated on improving mechanical properties and water absorption of AAC. The compressive and tensile strength tests and water absorption test was conducted on 10 x 20 cm cylindrical and 10 x 10 x10 cm cubical specimens. The results showed that pozzolanic materials can improve mechanical properties and water absorption of AAC. The compressive strength for AAC mixes containing silica fume, zeolite, and granulated blast furnace slag, increased up to 184%, 200%, and 172% compared with AAC control mix. In addition, the use of pozzolanic materials with the ratio of 21% by weight of cement improved tensile strength of AAC up to 25%. Generally, silica fume, zeolite and granulated blast furnace slag in different replacement levels decreased water absorption up to 50%, 45%, and 35%, respectively.

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The main material that causes aggregates to adhere to each other and forms a hard object called concrete is the cement paste. Cement paste consists of cement and water. Obviously, the higher the strength of the cement paste, the ultimate strength of the concrete made from the dough will be high. In this research, an additive material as powdered pumice of Bneh-Kohul mine near Bostan Abad and another additive as Mamaghan diatomite were added to the cement paste. Because these two materials have pozzolanic properties, they will exhibit their cementitious properties in close proximity to our cementitious materials and, as a result, are considered as cement materials. Symptoms related to the naming of different mixture ratios are clearly identified in both tables 4 and 5. In brief, the signs that contain the letter P include Pumice Powder and PD symptoms, including Pumice Powder and Diatomite Powder. The ratio of water to cement materials is considered to be 0.35 and 0.4. The results of the experiments have shown that, in terms of water absorption during treatment, all samples gradually absorb water and also show that hydration reactions of cement materials and the formation of crystals continue to occur regularly. In terms of water absorption of 28-day samples according to the ASTM standard, the results show that the porosity of our dough with different ratios of Pumice Powder  or combination of Pumice Powder and diatomite powder, and this porosity is increased by 0.35% To 0.4%. Water absorption during treatment indicates the progression of hydration reactions. While water absorption of concrete specimens at 28 days of age, according to ASTM C642-06, indicates the internal porosity of concrete, including occlusive bubbles and Capillary tubes. It should be noted that the water density of the gel was higher than that of the ordinary water and was about 1.1, and the density of the molecular water inside the crystals resulting from the hydration reactions was higher than that of the gel water. In terms of the compressive strength of doughs that only have pumice  powder additive, their 28-day compressive strength has a loss of resistance, and also for these samples at 90-day age, a slight drop of resistance is observed for the water-to-cement ratio of 0.35 However, for the 0.4% cement ratio, about 10% increased resistance. In the samples that were added to the pumice powder and diatomite powder as additive, the compressive strength changes were as follows: a) for the water-to-cement ratio of 0.35 at the age of 28 days and 90 days, an average increase of 6% Resistance is present and increases resistance for the optimum additive (25%).
b) For water-cement ratio 0.4% at 28 days for 20% additive of compound powder, compressive strength reduction is noticeable, but in the 90-day life it is 5% stronger and for 25% additive compound powder at the age of 28-day and 90-day, both increase in compressive strength of 9% and 16%, respectively. Therefore, adding of the combined of Bostan Abad Pumice Powder and Diatomite Powder is recommended.

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The structure must be able to maintain its stability and resistance in the event of a fire to protect human life. From time immemorial, concrete has been known to have fire-retardant properties. Thatchr('39')s why the biggest concern with concrete structures at the time of the fire was the reinforcement and their non-flow. But with the development of concrete technology, the focus has also shifted to improving the mechanical properties of concrete to increase its fire resistance. The use of pozzolans and additives in concrete to achieve high-strength and durable concrete has been in the concrete industry for several years. In this study, the role of seashell and lumashell powder and their effects on the mechanical properties of concrete and achieving the optimal percentage of using shellfish powder to achieve high fire resistance and durability have been studied. For this purpose, laboratory tests involving slump evaluation, water absorption percent, and compressive strength under high temperature were conducted on samples in which the replacement ratios of Portland cement with the same weight of shell powder were 2.5, 5, 10, 15 and 20% weight percent. Experimental results showed that seashell and lumashell powder increase the hydration rate and consequently caused an increase in the heat of hydration which resulted in a faster loss of water in the concrete. Furthermore, Seashell and Lumashell powder absorbed more water than cement due to their finer particles. All these ultimately resulted in a reduction in concrete slump such that regardless to the shell powder type, adding 2.5, 5 and 15% of shell powder, in average led to 13.5, 27.5 and 52% reduction in concrete slump respectively and it became approximately constant when the used shell powder was in excess of 15%. In addition, results showed that the presence of seashell and lumashell powder decrease water absorption in samples and made them more impenetrable. It happened because by filling the void in the cement paste with fine powder particles, the permeable cavities have been reduced and the connection paths of the cavities have been somewhat blocked. Replacement of cement with 2.5%, 5% and 10% of Seashell and Lumashell powder led to (27%, 44%, 73%) and (7%, 59%, 73%) reduction in concrete water absorption values respectively and it became approximately constant when the used shell powder was in excess of 10%. The results of this study also showed that the replacement of cement with Seashell and Lumashell powder slightly increases the thermal resistance of concrete and the amount of replacement of 5% by weight of cement with shell powder is reported as the optimal percentage. Adding more than 5% shell powder as a substitute for cement, regardless of its type, is harmful and significantly reduces the thermal resistance of concrete. Also, the results of laboratory tests showed that when concrete is exposed to high temperatures, properties such as load-bearing capacity and durability are reduced, leading to cracking, loss of compressive strength and concrete divot. Finally, it can be concluded that the optimal percentage of using seashell and lumashell powder instead of Portland cement can lead to a suitable concrete in terms of respect for the environment.
 

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In this research, extrusion technology was used to produce high-fiber snacks made from fresh cauliflower, corn starch, and corn flour. For this purpose, a central composite design and the response surface method (RSM) effects of various factors, including screw speed (120 to 180 rpm), cauliflower percentage (15%, 20%, 25%), and their impact on macrostructural, functional and color characteristics, such as expansion ratio, porosity, water solubility, water absorption index, and color changes of the snacks were investigated. The results demonstrated increasing the percentage of cauliflower increased the water absorption index (P<0.05) and whiteness index (P<0.0001) and also decreased the expansion ratio (P<0.0001) and porosity (P<0.0001) of the snack. It had no significant effect on the water solubility index. Increasing the screw speed led to an increase in the expansion ratio (P<0.0001), porosity (P<0.0001), solubility index in water(P<0.0001), and decreased whiteness index(P<0.0001) and water absorption index (P<0.05). The optimal sample was obtained by considering the maximum amount of cauliflower, the maximum water absorption index and the expansion ratio equivalent to the amount of cauliflower of 25% and the screw speed of 180 revolutions per minute with a desirability of 0.81 And after performing the test on the predicted values of the software, the non-significance of the average difference between the actual sample analysis results and the predicted sample values was observed, and The observations of the study indicate the promising potential of extruded snacks for enrichment purposes.

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The energy used to provide cooling and heating is a significant part of the energy consumption of an industrial complex. This paper aims to evaluate the performance of a trigeneration solar-powered system to supply the air conditioning system of an industrial complex energy requirement. The proposed design includes a double-effect lithium bromide water absorption chiller, a heat pump, and concentrating photovoltaic-thermal solar collectors (CPVT). Absorption chillers with nominal capacity and coefficient of performance of 100 TR and 1.3, respectively, and a heat pump with a capacity of 30 TR have been used to meet the cooling demands. The solar system consists of linear Fresnel solar concentrators and triple-junction solar cells. The analysis has been conducted for the complex located southwest of Tehran, Iran. Dynamic system simulation is performed using TRNSYS and EES software. To compare the performance of the proposed collector, photovoltaic-thermal collectors without concentrators (PVT) and Thermal collectors with concentrators (CT) with the same coating surface have been investigated. The energy delivered by the proposed collector is 64% and 28% higher, respectively than the PVT and the CT collectors. Compared to a structure without solar energy utilization unit, the proposed design reduces energy consumption by 62%. Employment of the heat pump in this method reduces energy consumption by 58% compared system without it. The proposed collector electrical energy production in a year is 101.10 MWh. The proposed system needs 264.07 MWh of backup heating a year to meet all the complex air conditioning needs.