جستجوی مقالات مرتبط با کلیدواژه « durability » در نشریات گروه « کشاورزی »

Agricultural residues and wastes are the main source of biomass for use in bioenergy production and animal and poultry feed production industries. These biomasses in their original form have a large volume and low energy (per unit volume) and require a lot of space and extensive movement. Therefore, one of the methods of optimal use of these biomasses is to transform them into pellets, which have more mass and energy per unit volume and enable their easier use and transportation. Currently, biomass has the fourth place in energy supply after oil, natural gas and coal and provides approximately 14% of the world's energy needs. The use of biomass, especially in European Union countries, as an attractive source for replacing fossil fuels is developing and expanding. The use of biomass as fuel has significantly reduced the amount of environmental pollutants, so that the amount of CO2 absorbed from the atmosphere during biomass growth is similar to the amount produced during combustion, followed by a net cycle of production.

 The raw materials for making pellets were prepared from spruce wood sawdust (collected from a sawmill in Sari) as well as corn stalk and soybean residues in the fields of Dasht Naz in Sari. The desired materials were transferred to the laboratory in the necessary amount and kept at ambient temperature until the experiments. The samples were first crushed into 20 mm sizes and then powdered using a grain mill (Mehr Tehiz company, Iran) and passed through 18 mesh sieves in the range of 1 mm to make pellets. A palletization mechanism was used to compress the pellet. This system was designed and built in biosystem mechanics of Sari University of Agricultural Sciences and Natural Resources. The material was placed inside a steel mold with a cylinder inner diameter of 8.05 mm and a height of 150 mm with a blocked end. A piston with a diameter of 8 mm connected to the driving arm of the tension-compression test machine was used to compress the material. Loading by a piston with a quasi-static speed of 5 mm per minute is compressed to a pressure of 1300 N.

In this research, the mechanical and thermal properties of pellets made from the combination of spruce sawdust and corn and soybean residues were evaluated. In the present study, the effect of four combinations of agricultural and forest materials at two moisture levels (12% and 18% based on fresh weight) on the indices of density, compressibility, Hausner ratio, strength and calorific value of the produced pellets were investigated and evaluated. it placed. The results showed that the pellet density at 18% humidity was lower than the density at 12% humidity. The highest density related to the combination of 60% spruce wood sawdust-40% corn stalks was obtained with a value of about 149 kg/m3 and the lowest value related to 100% soybean stalks was about 110 kg/m3. Also, the ratio of Hanser and CI in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the permissible range. The highest pellet strength was 23.8 N/cm corresponding to 100% sawdust at 18% humidity and the lowest was 15.4 N/cm corresponding to 100% soybean stalk at 12% humidity. The calorific value of the pellets is in the range of 14.37 to 18.52 MJ/kg, which is the minimum value for the pellet made from 100% soybean stalk at 18% humidity and the maximum value for the pellet made from 100% fir wood sawdust and It was obtained at a humidity of 12%. Therefore, the use of agricultural wastes and their proper combination is a good option for the production of biofuels due to their density and strength.

 The type of biological waste and moisture percentage affect the physical and mechanical properties of the produced pellets. In general, the combination of spruce wood sawdust with corn stalks and soybean improved the mechanical and thermal properties of the pellet. Hanser's ratio and compressibility in the combined pellets that have a higher percentage of sawdust and also in the combination of sawdust with corn stalks are within the standard range. Also, in the compositions that have a higher proportion of spruce wood sawdust and lower moisture, the density and strength factors of the pellet increase. The highest and lowest calorific values were obtained in a higher ratio of sawdust and a higher ratio of corn, respectively. Therefore, it is possible to make pellets from the waste of garden and agricultural products that have good density and strength and high calorific value.

This study aimed to investigate the effect of aloe vera gel coating (Aloe barbadensis Miller) with different concentration on quality and shelf life of fresh fish fillets Asian sea bass (Lates calcarifer) during refrigerated storage (4º) was performed. The desired concentration of 40%, 70%, 100% and a treatment of uncoated as controls. Chemical and microbial tests including TVB-N, TBA, PH , TVC and sensory analysis (color, odor, tissue and general) for treatments on days 1, 6, 11,16 was conducted. The treatments coated with the gel TVB-N and TBA from the sixth day showed a significant difference with the control treatment(p<0/05) And on the sixteenth day of treatment was seen in 40% best results. PH value also increased over time and was higher in the control of other treatments on the final day minimum value PH of the treatment was 70% sample. TVC value is significantly (p<0/05)  higher than the sixth day after the treatment was greater than the other and 40% on the final day had the lowest bacteria count. At the end of the control of chemical and biological indicators on the situation was unacceptable and sensory assessment higher than other treatments to control. As a result of this study, covering 40% and 70% Aloe Vera Gel addition to chemical factors and Asian sea bass fillet also had good effects on sensory index. And cover the gel with a concentration of 40% and 70% for the eleventh day is recommended.

Persian Shallot is a vegetable and at the same time a rare medicinal plant with a short shelf life. Edible coatings increased shelf life and maintain the quantitative and qualitative characteristics of some vegetable crops in the post-harvest stage. In this study, the effect of different amounts of chitosan (0.5, 1 and 2%), gelatin (0.25, 0.5 and 1%) and aloe gel (50, 75 and 100%) as edible coatings on fresh-cut persian shallot during 14 days of storage under refrigerated conditions (4±1 °C and 75-80% relative humidity) were investigated. The weight loss, pH, flavor index and total soluble solids during storage in coating treatments compared to control samples showed significantly less increase and amount of ascorbic acid, titratable acidity, pyruvic acid, total antioxidant capacity, total phenol, and soluble carbohydrates, showed significantly less decline. In this study, it was observed that edible coatings of chitosan (2%), gelatin (1%) and aloe gel (100%) had the greatest effect on maintaining the shelf life and quality properties of fresh-cut Persian shallot, respectively. According to the results obtained of this study, chitosan coating (2%) is recommended as a more suitable coating for fresh-cut Persian shallot.

Concrete mix-design specifications for concrete lining of irrigation canals in different regions are often considered the same by designers. However, the destructive factors of durability and instability of this structure are not same in different environmental conditions and so separate designs must be presented in different conditions. In this study 9 types of concrete mixes including: 3 grades of cement level, 3 ratios of (W/C) ratios and 3values of AEA were prepared. To determine specifications of durable concrete for irrigation canals in cold regions, various laboratory experiments on fresh and hardened concrete was performed. Cement grades of 325, 350 and 375 kg/m3 of concrete and w/c ratios of 0.4, 0.45 and 0.5, as well as AEA values of 0% (without AEA), 0.01 and 0.03% of cement weight was used. After preparing the concrete mixtures, different experiments on fresh concrete, including determination of slump, total air percentage, density and hardened concrete, including water absorption tests, compressive strength, modulus of elasticity and freezing-thawing cycles were performed up to 300 cycles. Based on the results, among the 9 concrete mixes samples, 3 mixes were durable in frost condition and were compatible with cold regions. These mixtures are as follows: 1- A mixture with a W/C ratio of 0.4, a cement grade of 350 kg/m3 and without AEA, 2- with a W/C ratio of 0.45 and a grade of 350 kg/m3 with 0.03% by weight of cement AEA, and 3- the W/C is 0.45 and the grade of cement is 325 kg/m3 without AEA. It was also found that using 1 to 2 kg/m3 of Concrete super plasticizer, the W/C ratio can be reduced to 0.4 and the concrete lining can be durable without using of AEA.

Abstract This research was conducted with the aim of evaluating the performance of Twenty-second generation improved indigenous hens in rural areas of Fars province in two hot and cold climates. For this purpose, two counties per climatic region, 3 villages per county and 4 families per each village were covered for a period of 72 weeks. Each family received twenty one 45-day old chickens. During the experiment period, mortality and egg production were recorded daily. Live body weight mean of hens was measured at 8, 12, 24, 48 and 72 weeks of age. The results showed that chickens raised in hot climate produced more eggs than those in cold climate during the experiment (P<0.01). Average egg mass in months and in entire experimental period, was significantly lower (P<0.01) in cold climate (Dasht Arjan and Sepidan Counties) than hot climate (Darab and Zarindasht Counties). Average live body weight was significantly lower in Dasht Arjan compared to other Counties at 72 weeks of age (P<0.05), but no significant difference observed between climates. Durability percentage in hot climate was significantly higher that cold climate during the experimental period (P<0.01). The mortality rate in indigenous hens was relatively high (%46). The cause of most mortality was disease. The mortality rate in this generation of indigenous hens at the station for up to 72 weeks, 14.8 percent was reported.

Rose is one of the most important cut flowers in the world, which its post-harvest preservation is considered as an important challenge. In this research, the effect of 200, 400 and 600 ppm concentrations of chitosan, cumin (Cuminum cyminum L.) and cinnamon (Cinnamomum verum L.) essential oils on post-harvest quality and inhibition of fungi Botrytis cinerea, the cause of gray mold disease, was evaluated in rose cv. Dolce Vita cut flower under laboratory conditions. For this purpose, the flowers were put in solutions with different concentrations for one hour and then were transferred into distilled water until the end of vase life.  Characteristics such as vase life, petal membrane stability index, leaf chlorophyll content, leaf, petal and stem water content, and petal soluble carbohydrate content were analyzed and recorded for 9 days after treatment with 3 days intervals. Application of herbal essential oils and chitosan at different post-harvest times resulted in improvement of most of the studied traits. Concentration of 200 ppm of chitosan and essential oils of cinnamon and cumin treatments was better than other concentrations in improving the majority of survival traits.  Treatments at 400 and 600 ppm concentrations prevented the growth of B. cinerea completely, too.  The results of this study indicated that the use of chitosan and plant essential oils of cumin and cinnamon improved post-harvest qualitative characteristics and inhibited B. cinerea fungi and thus increased the vase life of rose cv. Dolce Vita. Therefore, the use of these bio-compounds in the form of a stable formulation is recommended to increase the shelf-life and improve the quality and quantity of rose cut flower.

In order to investigate the effect of calcium ascorbate on quality changes of ‘Golden Delicious’ apple during storage, an experiment was conducted in a completely randomized design with three replicates in 2017. The main factor was the concentration of calcium ascorbate (0, 2.5 and 5%) and the sub factor was different storage times (90,150 and 210 days). The results showed a significant increase in total soluble solids, browning index, ethylene production and a significant reduction in total phenols content, vitamin C, titratable acidity, fruit firmness, and fruit postharvest life with increase in storage time. In addition, by the increase in calcium ascorbate concentration, the total acidity, tissue firmness and shelf life were increased (22.31, 17.83 and 8.54 %, respectively) and ethylene production rate was decreased (60.82 %(. The interaction effect of calcium ascorbate and storage time on phenolics content and ethylene production was also significant. The results showed that calcium ascorbate at all concentrations decreased the ethylene production and with increase in storage time, the production rate of the ethylene was increased in all treatments. The highest ethylene production rate was recorded in control fruit after 210 days of storage. However, calcium ascorbate increased the shelf life of apple fruit during storage by slowing the rate of ethylene production and ripening processes.

In the present study, the effect of ground sesame seeds in three levels of 0, 0.15 and 0.25% on features of biological, chemical and sensory evaluation silver carp surimi gel in vacuum packing for 4 months in freezing temperatures (-18°C) was investigated. The results showed that the highest levels of volatile nitrogen month 4 in the control (21.99±0.32mg per 100g), respectively. The thiobarbituric acid did not like the higher limit the amount of free fatty acids is increased. The highest bacteria in month 4 in the control (6.86±0.05Log cfu/g) treatment, respectively. The highest and lowest amount of lactic acid bacteria, respectively, on May 4 in group 1 (4.86±0.10Log cfu/g) and May 1 in all treatments (2.00±0.00Log cfu/g), respectively. Sensory evaluation factors during 4 months in freezing temperatures are not significantly different the colorimetric parameters (L*, a*, and b*) and tissue treatments poll 0.25% sesame seed powder was the best treatment. According to the results of chemical analysis, sensory and microbiological shelf life achieved the best treatment was 0.25% in the fourth month, ground sesame seeds.

Dried and powdered onionshave many applications in food production.But during onion drying, nonenzymatic browning reaction happens which decreases its quality. In this study, different pretreatments before onion drying were used to prevent destructive reactions. After pealing and grating the onions, they were treated with three treatment methods of sodium metabisulphite 0.5%, citric acid with pH=4 and 10% salt (NaCl) for two minutes. Then, the treated onions were dried at cabinet dryer at two temperatures of 800C and 900C till reaching moisture content of 6 and the produced powders were kept for two months at room temperature and qualitative tests were carried out on them at days 1,30 and 60. Results showed that the pretreatments had significant effects(p

In this study, the nanoemulsion containing Mentha longifolia essential oil was produced by using high-pressure homogenization method and its fumigant toxicity was compared with ordinary M. longifolia essential oil on different stages of Ephestia kuehniella. Experimental conditions were as follows; 27±1 °C, 70± 5% relative humidity in total darkness. Concentrations of 111.1-1111.1 and 62.9-92.6 µl/l air of oil have been used to control larva and eggs, respectively. Nanoemulsion concentrations were studied at 122.2-1111.1 µl/l air for larvicide experiment and 81.4-114.8 µl/l air for ovicidal stage. PT50 value at 1111.1 µl/l air as a larvicide for nanoemulsion and oil was estimated about 15.18 and 3.69 days, respectively. This value, at 92.6 µl/l air on egg was 14.44 and 2.58 days, respectively. The relative median potency parameter (RMP) showed that there was significant difference between PT50 values of essential oil and its nanoemulsion on both of the two stages of pest. Results showed that nanoemulsion containing M. longifolia oil can release slow properties lead to durability of fumigant toxicity of oil in the long term. Therefore, this new formulation could be considered as a new and ecofriendly biopesticide in pest control.

Introduction. Apricot is a soft fruit that normally does not have any resistance to transportation and storage conditions. In addition, apricots are climacteric fruits, produces high levels of ethylene during ripening process and have a high respiration rate. For this reason, they are very susceptible to physiological and microbial spoilage and have a very short shelf life. Thus, it is difficult to export this product with good quality and low waste or it is very limited. Application of edible coatings could increase the storability of apricots and delay their spoilage. Edible coatings cover the surface of the fruit and function as a barrier against water vapor, respiration gasses, and microorganisms. The effect of different natural polymers as edible coatings on the quality and shelf life of different fruits has been investigated by many researchers. Chitosan has been used in the formulation of edible coatings to extend the shelf life of citrus, papaya, strawberries and grapes (Arnon et al. 2014; Ali et al. 2011; mehrzad et al. 2011; Mostofi et al. 2011). Apples coated with whey protein concentrate showed more lightness compared with non-coated ones (Perez-Gago et al. 2006). In most studies, the effects of single edible coatings on the quality of fruits have been studied. In this research the quantitative and qualitative changes during ripening and cold storage of apricots coated with different formulations of whey protein concentrate, sodium alginate and chitosan were studied.
Materials and methods "Rajabali" variety apricots were picked up at optimum maturity and damaged ones were separated. Edible coating solutions were prepared by dissolving different amounts of whey protein concentrate, sodium alginate and chitosan in to distilled water. Glycerol was used as plasticizer. The apricots were dipped in the prepared solutions with different concentrations for at least five minutes. Then they were stored for 35 days at 2°C. Some quantitative and qualitative characteristics of coated apricots, such as weight loss, acidity, color, texture, shrinkage, browning reactions, vitamin C, and microbial load were determined after 0 and 35 days of storage. The results were analyzed by response surface methodology based on central composite design with five replications at the central point.
Results & discussion. The statistical analysis of the results by central composite design (CCD) indicated that the different concentrations of whey protein did not have any significant effect on weight loss during storage. The weight loss decreased as the concentration of sodium alginate and chitosan increased. Chitosan and sodium alginate had an important role in maintaining firmness. The firmness of apricots were highest at the upper limit of sodium alginate (1%) and chitosan concentrations (2%). The b* (yellowness) and L* (lightness) values of the apricots were increased as the concentration of chitosan was increased and the concentration of sodium alginate decreased. No significant difference was observed between the a* values (redness) of apricots treated with different coatings. In addition, the acidity of the apricots was increased by increasing the concentration of chitosan and decreased by increasing the concentration of sodium alginate. Browning of the coated fruits was also increased as the concentration of chitosan was increased to 1%. Increasing the concentration of sodium alginate increased the shrinkage of the apricots at low concentrations of whey protein concentrate and decreased it at high concentrations of whey protein concentrate. It was also shown that increasing concentrations of chitosan would reduce microbial load. The optimization of the formulations with Design Expert software showed that the best formulation of edible coating for preserving apricots was 1.45% of chitosan, 1.25% of alginate, and 0 percent for Whey protein concentrate.

Every day the harmful effects of chemical preservatives including carcinogenic effects and teratogenic properties and toxic residues on human health and the demand for food is proved that they naturally shelf life increased, more and more. The aim of this study was the first substitution made sorbate with and impact on the physicochemical, biological and tissue has been muffin. Propylene glycol, sorbitol and glycerin each in quantities of 2/5% and potassium sorbate replace part of the water in the formulation was completely removed. Statistical analysis using software provided SPSS19 and was completely randomized design. Physical and rheological characteristics such as density and viscosity as well as physico-chemical characteristics, shelf life(Mold and yeast) and organoleptic characteristics were evaluated Muffin .The results showed significant differences in the characteristics of pulp density and viscosity, hardness, texture, moisture, aw, sensory analysis (taste and overall acceptance) was observed. In total elimination of potassium sorbate and lasting effect on the microbial samples were Muffin. Sensory evaluation done show that the treatments tested in this study, treatment with 0/5% propylene glycol, 1/5% sorbitol, 0/5% glycerin in terms of overall acceptability had the highest score of sensory evaluation was introduced as the best example. After that treatment with sorbitol and control treatment. Samples with propylene glycol lowest score received for evaluation.

The evaluate the effect of gibberellic acid (zero, 100, 200 and 400 milligrams per liter) on quantitative growth characteristics of two varieties of Snapdragon (Antirrhinum majus) a factorial experiment base on a completely randomized block design with three replications were designed. Seedlings 50 days after sowing seed (6 to 8 true leaf stage) was exposure treated with gibberellic acid levels (as foliar). The results showed increased concentrations of gibberellic acid was enhanced significantly traits. The largest number, length and diameter of the branches of flowering, inflorescence length, floret number, number of leaves, vase life and also shoot fresh weight was obtained of the interaction between 400 and 200 ppm gibberellic acid and the yellow varieties (Apollo) and were then white varieties (Alba). Among different concentrations of gibberellic acid maximum diameter of the floret, leaf area, chlorophylls a, b and total and shoot dry weight was obtained of 400 mg/liter GA and the lowest in the control. The leaf area and shoot dry weight in yellow variety was higher than the white variety.

Essential oils of some plant species have shown suitable insecticidal properties against stored-product pests, which are one of the main factorsaffectingpost-harvestfoodlosses. In this study mortality, repellent effects and durability of fumigant toxicity of the formulated essential oils of golpar (Heracleum persicum), thyme (Thymus vulgaris), eucalyptus (Eucalyptus globules), peppermint (Mentha piperita) and rosageranium (Pelargonium roseum) as 2.5 gr sticks (10%), were studied on two important pests of stored products, Oryzaephilus surinamensis and Trogoderma granarium in laboratory at 28 ± 1 °C, 70 ± 5 % RH and dark condition. The results showed that sticks of rosageranium and golpar had the lowest toxicity and sticks of peppermint and thyme had the highest toxicity effects especially on O. surinamensis. The highest repellency effect was observed in peppermint and eucalyptus on O. surinamensis (94 and 91/6 % respectively) while repellency of rosageranium sticks was observed below 20% on both pests. Sticks durability in comparison with pure essential oils of plants was significantly different so that from the fourth day by the end of the eighth week the mortality rate was approximately constant while the durability of pure essential oils decreased after 2-3 weeks represents the slow-releasing of essential oils in stick formulation.

In this research, the effect of putrescine, spermine and spermidine on the vase life of cut red carnation (Red Corsa) and some physiological traits was investigated in horticultural laboratory of Azad University branch Rafsanjan in 2015. Therefore, an experiment based on completely randomized design with tree levels of 1, 2 and 3mM of putrescine and 0.5, 1 and 2mM of spermidine and 1, 2 and 3mM of spermine with 3 replications was performed. The recorded traits included vase life and morphological and physiological factors. The results indicated that all of the treatments increased vase life significantly compared to control treatment. On the other hand polyamines decreased ethylene production. Spermidineof 2 mM caused the highest vase life and the lowest ethylene production. All of the treatments especially 2 mM of Spermidine increased flower diameter and solution uptake content significantly compared to control treatment and 2 Mm of spermidine have been the most effective treatment. 1 and 2 mM of spermidine were only treatments that don’t reduce dry matter percentage significantly in the flowers. 2 mM of Spermidine caused the maximum amount of physiological traits as protein, chlorophyll and total soluble solids in the leaves of flowers. Therefore, 2 mM of Spermidine is suggested as the best treatment to increase postharvest life in Carnation cv. Red Corsa.

Application of chemical polymers is one the effective methods for stabilization of soils. In this research, the effects of Polyvinyl Acetate Polymer on stabilization of soils and erosion control has been investigated. To do this, three different soils types were treated with five levels of Polyvinyl-Acetate emulsion and cured for three ages. Thus, considering three replication for each samples totally 135 specimens were prepared and tested for determination of their compressive strength. Statistical analysis of the results showed that the adding of polymer increases the compressive strength of the samples significantly, where the rate of increase depends on soil texture and varies from 15 % in clayey samples to 400 % in sandy soils. Furthermore, the compressive strength of the samples significantly affected by the age of the samples and deacreased upto 15 and 28 percet after 3 and 6 months respectively. Also based on durability tests, addition of polymer to the samples makes the sandy samples durable but has no effect on the durability of clay samples. Finally, application 25 g of polymer per square meter of soil was determined as the optimal treatment to stabilize the studied soil.

Concrete is the most common material used to line irrigation canals and must maintain its durability for the lifetime of the canal. Compressive strength has been used as an index to control the quality of concrete; concrete that remains durable under freeze-thaw conditions is that with high compressive strength. Research has shown that concrete linings can show suitable compressive strength in the first days of existence, but begin to decompose after a period and lose the property of durability. The present study examined the relationship between compressive strength and the durability parameters of initial water absorption, final water absorption, water penetration depth and porosity in the Variyaneh and Dingel-e Kahriz irrigation canals in the province of Hamedan. Laboratory testing was carried out on 27 cores (69 mm in diameter; different lengths) extracted from the concrete linings of canals. The cores were prepared and their compressive strength and durability parameters were determined. The results show an inverse linear relationship between the compressive strength and density of the samples and their porosity. The durability parameters of initial water absorption, final water absorption, and water penetration depth showed no significant relationship. The results indicate that compressive strength is not sufficient for evaluation of the durability of concrete lining. Of the 27 cores, 40% had acceptable compressive strength. Of these, 50% showed acceptable durability parameters for exposure to freeze-thaw. The results also showed that the mean penetration depth and porosity of the samples were >2.5 timesgreater than the maximum recommended values and that the initial and total water absorption values were >1.5 times greater than the maximum recommended values. It is evident that the concrete linings will decompose more quickly than the anticipated lifetime from the influence of water and other expansive solute solutions in cold weather. It was noted that samples having similar compressive strengths had durability parameters that were greater or less than acceptable values. These results suggest that the compressive strength of concrete alone is insufficient to ensure durability and it is necessary to examine additional parameters affecting the lifetime of the concrete linings.

This study was conducted to investigate the effects of using Gracilariopsis persica in layer diet on performance، egg quality and lipids of blood serum of layer hens. One-hundred Hy-line W-36 hens were allocated to five dietary treatments (experimental diets containing 0، 5، 10، 15 and 20 percent seaweed) and five replicates and four birds in each for 12 week period (23-34 week of age). The results showed that in the birds fed diets containing more than 5% seaweed، had lower egg production and higher feed conversion ratio (P<0. 05). There was significant decrease in egg mass for more than 10% seaweed in experimental diet (P<0. 05). Inclusion of Gracilariopsis persica in diets increased egg shell thickness and egg density compared to control diet (P<0. 05). The egg that laid by hens fed on diets containing different levels of Gracilariopsis persica had lower concentration of Malonedialdehyde and higher iodine content than those laid by control birds (P<0. 05). Using Gracilariopsis persica in diets had no significant effect on yolk cholesterol، however، its inclusion at 15 or 20% in diet، decreased cholesterol concentration of blood serum (P<0. 05). These results demonstrated that Gracilariopsis persica can be include up to five percent in layer diets. It improves eggshell thickness and egg density، and also increases iodine content in yolk and the egg durability.

To evaluation of irrigation canals lining, uaually compressive strength is determined, whereas new studies proved that this paprameter cant guarantee lining durability during its lifetime. Durable concrete in cold climate can save its serving in lifetime. In this paper durability of hardened concrete in irrigation canals in Bahar plain in Hamedan province were evaluated and results were compared with prescribed standards. For this purpose, 5concrete lined canals were selected to study and field and laboratory examinations were done. Name of selected canals is Gondejin, Bahadorbeig, Abroomand, Khooshab-olia and Komooshboolaghi. Field examinations were including: 25 samples coring from these canals. Laboratory examinations were including: determination of specific gravity, initial and final water absorptions, depth of water penetration in cores. Results showed thatmean values of specific gravity, initial and final water absorptions, depth of water penetration in cores were 2.1 gr/cm3, 5.8%, 7.7% and 79 mm respectively. Based on prescribed standards mean values of these parameters must be 2.4 gr/cm3,3%, 5% and 30 mm respectively. With comparision results and prescribed standard values, it can be noted that measured mean values of specific gravity of cores is 15% less than standard. Initial and final water absorptions and depth of water penetration in cores are 3, 1.5 and 2.5 time, respectively, more than those in standards. These results express that concrete lining of studied irrigation canals is undurable for freezing-thaw condition. High permeability and high water absorption of cores is due to high porosity and low compaction. Field observations confirmed these conclusions. Because of unsuitable durability of cores, it can be concluded that concrete lining in studied canals are not secure lining in front of freeze- thaw cycles in their lifetimes.