Input-outputtable is a suitable way to identify the key sectors of regional economy. multiplier coefficients of demand and supply extracted from input-output table may be used to calculate the innovating sectors of demand and supply and consequentially their key sectors. multiplier coefficients are classified as gross and Net (innovated by Oosterhaven&Stelder, 2002). . This study attempts to calculate the gross and Net multiplier coefficients for the province of Markazi. The results show that for regional studies the gross multiplier coefficients work better than the Net multiplier coefficients. The Net multiplier coefficients divide economic activities in two groups of supply or demand; therefore, they cannot be used to create regional key sectors in Iran. However, the gross multiplier coefficients divide the regional economic activities into four groups and can be used to identify the key sectors in Iran.

There is no doubt that tourism industry has a special place among the factors of the economical growth and development in modern world. Based on statistics, the US has the first place in highest income earning by tourism with 6 billion dollars and Spain and France in next places. Tourism industry as a common economic factor, has been very noticeable, and because of this, it is been tried to prevent from the effective factors of the decrease of tourism as much as possible. In capable countries, fundamental possibilities must be provided to develop tourism. From economical point of view, there are a lot of advantages in the fields of employment. Tourism absorbs money and people from centers toward villages, countries, and natural sites together with different absorbing sights. Each unit of this money in the degree of economic growth of countries is handed and given by tourism 3-10 times every year, so tourism industry causes double efficiency occurs in the economy of the host country. Tourism industry in the international level, and also in our country is developing rapidly. Whenever we tend to change the single economic production of petroleum; tourism industry will open very suitable doors through development. But activities in this field need ongoing planning.Valuable sources of ancient and historical architectural places which have taken place throughout the state of East Azerbaijan within my serious beauties of this state all together are valuable factors that cause to absorb many home and forgone tourists.Located on the silk road, and Eastern Asia-Europe rath, beautiful natural landscape, neighboring with Middle-East countries, enjoyment of free commercial zone and haring the biggest roofed passage in the world are the factors that emphasize on the importance of Eastern Azerbaijan tourism industry. 533 known tourist attractions and 258 natural ones indicate the natural and historical importance of Eastern Azerbaijan as a touristy center, But the existing tourist facilities are not able to respond the growing needs of tourists in Azerbaijan and facing numerous problems in this field. The survey method in this papers is descriptive-analytical, inferential, stressing on analogical course and used interview, questioning, observation methods based on statistics and information of relevant departments and offices through analyzing with various software. In this article, first kinds of models used in planning programs are introduced And the models of tourism development co efficiency is discussed.

Background and objectives: Increasesing CO2 concentration in the atmosphere have prompted renewed interest in increasing the carbon soil stocks in the agroecosystems to mitigate climate change and also improve soil quality (14, 26). Predicting the changes in carbon stocks of soil, depends on reliable estimates of Net primary production (NPP) and the proportion of the NPP returned to the soil. NPP defined as the increase in plant mass (biomass) and losses (such as mortality, leaf abscission, herbivory, etc. ), in both above-ground and below-ground biomass per unit area of land per unit of time. The annual NPP in agroecosystems and the distribution of carbon for both above-ground and below-ground tissues of plant, is usually calculated from agricultural yield (3, 8, 17). Our purposes were to estimate a set of coefficients for calculating below-ground NPP, above-ground NPP, total annual NPP, relative coefficients of carbon allocation, allocated carbon content and annual carbon inputs to soil for major agricultural crops in Khorasan-Razavi province. Materials and methods: Shoot and root biomasses for major agricultural crops in Khorasan-e Razavi province such as wheat, barley, corn, cotton, sugar beet, alfalfa and chickpea at plant maturity were measured during two years 2015 and 2016. The crops in all studied fields were fertilized according to local recommendations. Four sub-samples taken for shoot and root biomass measurements from 10 fields (which were subsequently averaged). Roots by using cylinders roots (below-ground biomass) were manually separated from the soil (10, 24, 30). After harvesting, shoots and root samples were separately dried to constant weight and expressed on a dry matter basis. Carbon content in each crop into four fractions including seed (CP), shoots (CS), roots (CR) and extra-roots (CE) were calculated in units of biomass carbon per unit area per unit of time (g C m-2 yr-1) (3, 9). Results: The results showed that relative coefficients of carbon allocation to different tissues, above-ground NPP, below-ground NPP and total annual NPP were significantly affected by different crop species. The highest contents of allocated carbon to above-ground and belowground tissues including seed (CP), shoot (CS), root (CR) and extra-root (CE) were observed for barley (4452. 78 g C m-2 yr-1), alfalfa (8602. 56 g C m-2 yr-1), alfalfa (2929. 39 g C m-2 yr-1) and alfalfa (1904. 11 g C m-2 yr-1), respectively. The maximum above-ground and below-ground NPP were calculated for barley and alfalfa with 12626. 28 and 4833. 5 g C m-2 yr-1, respectively. Conclusion: Relative coefficients of carbon allocation among different tissues of each crop is a useful approach for evaluation of soil carbon changes in agricultural systems. Indeed, carbon input and NPP are the most important variables for predicting the Net rate of soil carbon changes.

In order to evaluate the effect of different crop management practices on corn (Zea mays L.) Net primary productivity (NPP) and relative carbon allocation coefficients, a field experiment was conducted based on a completely randomized block design with four replications in the Agricultural Research Station, Ferdowsi University of Mashhad, Iran during two growing season 2008-2009 and 2009-2010. Treatments including two low input management systems based on application of cow manure and compost municipal made from house-hold waste, a medium input system and a high input system. Application of inputs and management practices were based on a basic assumption made prior to the start of the experiment. On the other words, for each of the management system the particular set of inputs were allocated. In this respect, for low input system 30 t.ha-1 cow manure or 30 t.ha-1 compost municipal made from house-hold waste, twice hand weeding were used. In medium management system, 15 t.ha-1 compost municipal made from house-hold waste, 150 kg.ha-1 urea, two seed bed operations, 1.5 l.ha-1 2, 4-D herbicide applied at five-leaf stage and one time hand weeding were used. In high input system, the inputs were two seed bed operations, 2 l.ha-1 Paraquat herbicide used after seeding and 1.5 l.ha-1 2, 4-D applied at five-leaf stage.Results showed that the effect of different crop management practices on the shoot biomass, seed weight, root biomass, total biomass, shoot biomass: root biomass (S: R), SRL and HI were significant (p≥0.01). High input management system enhanced total biomass and S: R and decreased seed weight, root biomass and SRL. The highest and the lowest total biomass observed in high input (18.3 kg.m-2.yr-1) and low input with using compost (10.3 kg.m-2.yr-1), respectively.The maximum SRL observed in low input based on cow manure application (19.8 cm.cm-3 soil) and the minimum SRL was in high input (1.3 cm.cm-3 soil). Range of relative carbon allocation coefficients to seed, shoot, root and extra-root were estimated as 0.10-0.17, 0.19-0.52, 0.23-0.39 and 0.15-0.25, respectively.Low input with cow manure application increased allocated carbon to seed, root and extra-root and decreased allocated carbon to shoot. The highest allocated carbon to root observed in low input with using manure (6.5 g C m-2.yr-1) and the lowest allocated carbon to root was in high input (2.7 g C m-2.yr-1). The maximum and the minimum NPP were obtained in low input with cow manure application (16.6 g C m-2.yr-1) and high input (8.9 g C m-2.yr-1), respectively. It seems that crop management system based on low input of cow manure application enhanced carbon allocation to below-ground biomass of corn due to improvement in soil physical, chemical and biological properties and also nutrient availability which could be regarded as an alternative to reduce CO2 production and moderate climate changes.

In this paper, we introduce the notion of multiplier in BL-algebra and study relationships between multipliers and some special mappings, likeness closure operators, homomorphisms and (ʘ, Ú)-derivations in BL-algebras. We introduce the concept of idempotent multipliers in BL-algebra and weak congruence and obtain an interconnection between idempotent multipliers and weak congruences. Also, we introduce the special multiplier ap and study some properties. Finally, we show that if A is a boolean algebra, then the set of all multipliers of A is a BL-algebra under some conditions.

Introduction: Climate change and global warming are the most important challenges in sustainable development, which is due to increased concentration of greenhouse gases in the atmosphere. Carbon dioxide is a major component of greenhouse gases. In order to reduce atmospheric carbon dioxide and to create a balance in the content of greenhouse gases, atmospheric carbon must be absorbed in organic forms (Dieleman et al., 2015; Lichtfouse, 2009). For this aim, a study was done in agricultural lands of Gorgan in order to estimate the carbon sequestration potential of soybean plant (Glycine max L. ). Materials and Methods This research was carried out in 150 soybean fields of Gorgan township and sampled by quadrate 0. 5Í 0. 5 m2 as random method, during 2016-2017. The soybean shoot and root organs were individually harvested and transferred to the laboratory. An electric burn furnace method was used to determine the carbon sequestration potential in soybean organs (including pods, seeds, stems, leaves and roots). Also, the amount of shoot to root and harvest index were estimated to determine the Net primary production based on carbon content in the above ground organ, below ground organ and total plant, and the carbon allocation coefficients in each soybean organ. Then, using different interpolation methods, the spatial distribution of carbon sequestration of the plant organs was investigated in ArcGIS software. All data were analyzed by SPSS software. Results and Discussion The results showed that Kriging method was the best model for carbon interpolation and distribution of carbon sequestration potential in agricultural lands of Gorgan township. The amount of stored carbon was obtained as 579. 64 kg. ha-1 in leaves, 744. 81 kg. ha-1 in stem, 881. 16 kg. ha-1 in seeds, 340. 16 kg. ha-1 in pods and 540. 21 kg. ha-1 in root. Also, according to harvest index (32%) and grain yield (3461. 13 kg. ha-1), other indexes were calculates as the ratio of shoot to root about 4. 30, the total Net primary carbon production 6734. 8 kg. ha-1, above-ground Net primary carbon production 4867. 2 kg. ha-1 and below-ground Net primary carbon production about 1867. 63 kg. ha-1. Also, the shares of the allocation coefficients of economic organs, stems, leaves, root and root secretions were 0. 23, 0. 49, 0. 61 and 0. 12, respectively. The zoning results showed that the total stored carbon potential in soybean plant was highest in the eastern, north and southeastern regions of the surveyed area, and the central, western and southwestern parts of this township had the lowest stored carbon potential. Also, the amount of carbon sequestration potential (total above ground and below ground organs) was as 3085. 98 kg. ha-1 in this study. Conclusion The highest proportion of carbon was allocated to the shoot organs, and the carbon of root exudates was also lower than other plant organs. In this study, it has been found that the potential of carbon sequestration was different in soybean plant organs and some variable such as agronomical management, soil and climatic condition can affect on its contents. AcknowledgementsWe are thankful to Gorgan University of Agricultural Sciences and Natural Resources (GUASNR), Agriculture Services Centers of Gorgan and soybean farmers for all their companions and supports.

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In this note we obtain a reverse version of the Haagerup Theorem. In particular, if $ A \in \mathbb{M}_{n}$ has a $ 2\times2- $ principal submatrix as $ \left[ \begin{array}{cc}1& \alpha \\\beta & 1\\\end{array}\right]$ with $ \beta \neq \bar{\alpha}, $ then $ \Vert S_{A} \Vert > 1$ where the operator $ S_{A}:\mathbb{M}_{n}\longrightarrow \mathbb{M}_{n} $ is defined by $S_{A}(B) := A \circ B $ where $ "\circ " $ stands for Schur product.