Wyniki wyszukiwania - Biblioteka Nauki

1

A comprehensive mathematical programming model for minimizing costs in a multiple-item reverse supply chain with sensitivity analysis

100%

Mahmoudi H. , Fazlollahtabar H.

Management and Production Engineering Review

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2014

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tom Vol. 5, No. 3

42--52

EN

These instructions give you guidelines for preparing papers for IFAC conferences. A reverse supply chain is configured by a sequence of elements forming a continuous process to treat return-products until they are properly recovered or disposed. The activities in a reverse supply chain include collection, cleaning, disassembly, test and sorting, storage, transport, and recovery operations. This paper presents a mathematical programming model with the objective of minimizing the total costs of reverse supply chain including transportation, fixed opening, operation, maintenance and remanufacturing costs of centers. The proposed model considers the design of a multi-layer, multi-product reverse supply chain that consists of returning, disassembly, processing, recycling, remanufacturing, materials and distribution centers. This integer linear programming model is solved by using Lingo 9 software and the results are reported. Finally, a sensitivity analysis of the proposed model is also presented.

2

A seroepidemiological survey of Q fever among sheep in Mazandaran province, northern Iran

80%

Esmaeili S. , Mostafavi E. , Shahdordizadeh M. , Mahmoudi H.

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2013

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tom 20

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nr 4

3

Bio-ketones from lignocellulosic biomass: experimental investigation on fuel properties, combustion and emissions characteristics of cyclopentanone blend with diesel in compression ignition engine

80%

Doustdar O. , Wyszynski M. L. , Tsolakis A. , Mahmoudi H.

Combustion Engines

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2017

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tom R. 56, nr 4

81--86

EN

Use of alternative fuels in compression ignition engines is the topic for many studies. This paper presents the results of lubricity, calorific value, viscosity, surface tension and density of a ketone blend with diesel to use as a fuel in compression ignition engine. Analyses of fuel properties are vital due to their effect on fuel system. In addition, this study is related to the development of future biofuels and it indicates the effect of oxygen double bond in molecular structure of ketones on important fuel properties. Cyclopentanone which has cyclic molecular structure was used; it can be produced from lignocellulosic biomass through various processing ways. This ketone was blended with diesel fuel at 10% vol. Results from fuel properties tests were compared to the conventional diesel fuel. In the next step this blend was tested in a research diesel engine to analyse its combustion behaviour and emission characteristics of exhaust gases; these results were compared with ultra-low sulphur diesel fuel. Results showed that cyclopentanone, as an additive to diesel, improved surface tension and density of the fuel but in contrast had negative effect on viscosity, lubricity and calorific value of the fuel, but still in the standard range. Combustion behaviour of this fuel in the diesel engine also showed longer ignition delay of ketone blend and also that gaseous emission such as CO and THC are higher than from diesel fuel and NOx emission is less than from conventional diesel fuel combustion.

4

Salt tolerance analysis of Arabidopsis thaliana NOK2 accession under saline conditions and potassium supply

61%

Kaddour R. , Baatour O. , Mahmoudi H. , Nasri N. , Zaghdoudi M. , Lachaal M.

Acta Physiologiae Plantarum

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2011

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tom 33

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nr 6

EN

The response to salt treatment and K⁺ provision of two Arabidopsis thaliana accessions grown for 17 days in the presence of 50 mM NaCl was investigated. Leaf and root dry weight deposition was restricted by salt, more in Col accession than in NOK2 accession. In both accessions, the growth inhibition induced by salinity was associated with a decrease in total leaf surface area, which resulted from diminished leaf number, but not from restriction of individual leaf surface area. Comparing the effects of salt on dry matter production and total leaf surface area revealed large difference between Col and NOK2 for net assimilation rate (the amount of whole plant biomass produced per unit leaf surface area), which was augmented by salt and K⁺ in NOK2 but not in Col. This result, which suggested a better capacity of NOK2 to preserve its photosynthetic machinery against salt stress, was in agreement with the effect of NaCl on photosynthetic pigments. Indeed, salt significantly reduced chlorophyll and carotenoid content in Col leaves but had no impact on NOK2 leaf pigment content. Since K⁺ provision had only marginal effects on these responses to salt stress, leaf mineral unbalance was unlikely. Guaiacol peroxidase activity was augmented by salt treatment in leaves and roots of both accessions. Salinity decreased the catalase activity in Col leaves and in roots, and increased this activity in NOK2 organs. In conclusion, when aggressed by salt, NOK2 was able (1) to produce more leaves than Col, and (2) to efficiently protect its photosynthetic apparatus, perhaps by developing more efficient antioxidative defense through increased catalase and peroxidase activities. Consequently, the overall photosynthetic activity was higher and more robust to salt aggression in NOK2 than in Col.

5

Varied tolerance to NaCl salinity is related to biochemical changes in two contrasting lettuce genotypes

51%

Mahmoudi H. , Kaddour R. , Huang J. , Nasri N. , Olfa B. , M'Rah S. , Hannoufa A. , Lachaal M. , Ouerghi Z.

Acta Physiologiae Plantarum

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2011

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tom 33

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nr 5

EN

Salt stress perturbs a multitude of physiological processes such as photosynthesis and growth. To understand the biochemical changes associated with physiological and cellular adaptations to salinity, two lettuce varieties (Verte and Romaine) were grown in a hydroponics culture system supplemented with 0, 100 or 200 mM NaCl. Verte displayed better growth under 100 mM NaCl compared to Romaine, but both genotypes registered relatively similar reductions in growth under 200 mM NaCl treatment. Both varieties showed differences in net photosynthetic activity in the absence of salt and 8 days after salt treatment. These differences diminished subsequently under prolonged salt stress (14 days). Verte showed enhanced leaf proline and restricted total cations especially Na⁺, lesser malondialdehyde (MDA) formation and lignification in the roots under 100 mM NaCl salinity. Membrane damage estimated by electrolyte leakage increased with elevated salt concentrations in roots of both varieties, but Verte had significantly lower electrolyte leakage relative to Romaine under 100 mM NaCl. Moreover, Verte also accumulated greater levels of carotenoids under increasing NaCl concentrations compared to Romaine. Taken together, these findings suggest that the greater tolerance of Verte to 100 mM NaCl is related to the more restricted accumulation of total cations and toxic Na⁺ in the roots and enhanced levels of antioxidative metabolites in root and leaf tissue.

6

Assessment of salt tolerance of Nasturtium officinale R. Br. using physiological and biochemical parameters

51%

Kaddour R. , Draoui E. , Baatour O. , Mahmoudi H. , Tarchoun I. , Nasri N. , Gruber M. , Lachaal M.

Acta Physiologiae Plantarum

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2013

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tom 35

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nr 12

EN

Nasturtium officinale R. Br. seedlings were treated with a range of NaCl concentrations (0, 50, 100 and 150 mM) for 21 days after seedling emergence. Physiological analysis based on growth and mineral nutrition, showed a substantial decrease in leaf dry matter with 150 mM NaCl treatment. The growth decrease was correlated with nutritional imbalance and a reduction in potassium accumulation and transport to the leaves. At the same time, we noted an increase in leaf sodium and chloride accumulation and transport. Salt tolerance of N. officinale under 100 mM NaCl was associated with osmotic adjustment via Na+ and Cl− and the maintenance of high K+/Na+ selectivity. Salt decreased carotenoid content more than chlorophylls and also disturbed membrane integrity by increasing malondialdehyde content and electrolyte leakage. At 150 mM NaCl, an increase in antioxidant enzyme-specific activities for superoxide dismutase, catalase and guaiacol peroxidase occurred in concert with a decrease in ascorbic acid, polyphenol, tannin and flavonoid content. These results indicate that N. officinale can maintain growth and natural antioxidant defense compounds such as, vitamin C, carotenoids, and polyphenols, when cultivated in 100 mM NaCl, but not at higher salt levels.

7

Physiological and molecular responses of two Arabidopsis accessions to calcium amendment and salt constraint

51%

Kaddour R. , Mahmoudi H. , Baatour O. , Tarchoun I. , Nasri N. , ben Saleh I. , Berthomieu P. , Gruber M. , Lachaal M.

Acta Physiologiae Plantarum

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2012

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tom 34

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nr 2

EN

The Arabidopsis thaliana NOK2 accession displays salt tolerance compared to more commonly known A. thaliana accessions, such as Col-0, but the basis of this phenotypic feature is unknown. This work was focused on determining whether salt tolerance in NOK2 plants is affected by calcium supplementation to the growth medium. A. thaliana seedlings were grown in pots containing a mixture of sand and peat under controlled conditions in a low-level Ca(NO₃)₂ medium supplemented with 0 or 50 mM NaCl with and without amendment with two higher levels of Ca(NO₃)₂. Calcium amendment was beneficial for salt-treated NOK2 plants, as shown by the increase in dry weight of NOK2 plants with and without NaCl, but had no impact on Col-0 biomass. Sodium accumulation decreased as a function of calcium amendment in NOK2, while Col-0 maintained its high Na levels under these conditions. Leaf K⁺ content, K⁺ uptake, and Ca content decreased in NOK2 and Col-0 plants growing in the low-level Ca medium when NaCl was added, but rose in leaves of both accessions with calcium amendment, although K remained low in both accessions in the absence of NaCl. K⁺/Na⁺ selectivity increased preferentially in NOK2 with increasing calcium in the presence of NaCl, but when Na was restricted and not under any conditions in Col-0. Preferential effects of calcium were not observed on the transcript accumulation of seven Na⁺, K⁺ or Ca²⁺ transport genes for either of the accessions, except for increased transcription of the CAX4 gene in NOK2 leaves at the highest calcium concentration used (5 mM). Leaf membrane leakage, which increased two-fold higher in Col-0 under salt application compared with the increase in NOK2, declined for both accessions in response to calcium supplementation, and in NOK2 this decline reached no salt levels when Ca²⁺ amendments were highest. Chlorophyll and carotenoid content dropped two-fold in Col-0 in response to salt, but were unchanged in NOK2 under these conditions. In contrast, leaf anthocyanins, which were normally tenfold higher in Col-0 than in NOK2 in the lowlevel Ca²⁺ medium, declined in Col-0 plants as a function of Ca²⁺ supplementation, but were maintained at low levels in NOK2 leaves regardless of salinity and calcium. In conclusion, NOK2 plants responded positively to calcium supplementation by improving biomass yield during salinity treatment, whereas this amendment only affected Col-0 by reducing its permeability and anthocyanin titre. K⁺/Na⁺ selectivity appeared to be an important characteristic of NOK2 response to calcium. The regulation of this response may involve the CAX4 Ca²⁺/H⁺ vacuolar transport gene, but does not appear to involve six other common ion transporters.