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Water erosion causes a series of on-site as well as off-site damages and problems on natural ecosystem. These damages include soil and nutrient loss and finally loss of productivity which causes costs to the society. So, this study attempts to quantify the economic value of soil productivity conservation as one of the important functions of rangelands vegetation and its economic cost by productivity losses. The soil loss amounts were obtained from integrated Geographic Information System (GIS) and map of erosion vulnerable areas using RUSLE model. Supplementary data such as soil nutrients (NPK) valuated from the measurement plots of a portable rainfall simulator (E65). Field plots were constructed to measure soil nutrients and soil loss from different soil types with different resistance to erosion. Rainfall simulation was carried out in three sites on the basis of geology map and different resistance to erosion. Nine experimental unit plots (1*1 m) were used to correlate nutrient loss to sediment losses. Assuming that nutrient loss by erosion could be replaced by fertilizers, economic cost of major nutrients estimated by market prices of fertilizers. Results showed that mean annual soil loss using RUSLE was 27.44 t ha^-1 y^-1 ranging from 0.0 to 996.06 t ha^-1 y^-1. Also, 114.17 kg ha^-1 y^-1 of N, P, K elements were lost in 2010 due to soil erosion in the degraded rangelands which costs (738944 Rial) 71.5 US$ ha^-1y^-1. Total economic cost of soil nutrient loss in 94978.6 ha of the rangelands of Nour-rud watershed basin, was estimated 70×10^{^}9 Rial (6.8×10⁶ US$). The maximum annual cost of soil nutrient loss was estimated in the "TRujs" geological formation (1.23×10⁶ US$) consisting of "gray shale, silt, sandstone, conglomerate" and the least cost belonged to the "Jl1" geological formation (0.916*10⁶ US$) which consists of "thin gray dolomite limestone". In economic terms there was a direct relationship between soil nutrient loss and its economic cost.

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Philosophy of the organization is dependent with human life. Humans make organizations alive, and move and manage them. Being assure of organizational commitment and HR fitness is one of the best ways to attract and retain talented employees and improve business performance. This study seeks to investigate the moderate effect of person- organization fitness on the relationship between organizational commitment and turnover intention. In terms of purpose this study is applied and data collection Method is descriptive – survey. Population is consist of shahid Chamran University of Ahvaz employees. Sample was 126 employees that selected randomly according to random sampling method. Data was collected using standard questionnaire and analyzed with partial least squares structural equation modeling approach. Results indicate that there is moderate effect of quality of person- organization fitness on relationship between organizational commitment and turnover intention.    

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Group works are benefit for persons and organization and if done correctly, it will help to organization progress. But sometimes some problems reduce the productivity of teams. One of them is social loafing which means reducing the efficiency of persons in group works relative to individual works. Understanding the affecting factors on social loafing is effective in reducing the negative effects of this phenomenon. so, this study investigates the effect of blood type on social loafing with mediating of personality type of DISC. The target population are 750 employees of the shuttle company who 256 of them were selected based on Krejcie and Morgan table. In terms of purpose, this study is applied and is quantitative and the collection of data is descriptive-survey method. Data were collected by a questionnaire and for data analyze we used SPSS software. The results showed that blood type had a significant effect on social loafing. The effect of DISC personality type on social loafing and also the effect of blood type on social loafing by mediating of DISC personality type were confirmed, but blood type didnt have any significant effect on DISC personality type. It can be concluded that blood type of individuals has a significant effect on social loafing and the incidence of social loafing is higher among people with blood types A than other blood groups.

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Research objective: Many organizations use idiosyncratic deals to achieve desirable behaviors and positive results. Such idiosyncratic deals lead to increased self-confidence, cooperation, and participation of the employees and the emergence of new creative ideas. The present study seeks to investigate the influence of idiosyncratic work deals on creative deviations whilst taking into account the mediating role of psychological entitlement and employee voice.
Methodology: The present study is applied research in terms of purpose and a descriptive correlation study in terms of data collection. The statistical population comprises Mobin Net Communication Company employees. 272 questionnaires were handed out based on simple randomized sampling and collected data were analyzed using AMOS and SPSS software. The questionnaires used to evaluate research variables include Rosen et al.’s (2013) idiosyncratic deals questionnaire (2013), Morrison’s employee voice questionnaire (2011), Li et al.’s psychological entitlement questionnaire (2017), and Lin et al.’s creative deviation questionnaire (2016).
Research findings: Idiosyncratic deals have a significant and direct influence on employee creative deviation and have and a significant and indirect impact on employee creative deviation through the mediation of employee voice and psychological entitlement.
Research innovation: The results of the present study strengthen the conclusion of idiosyncratic deals contract in Iranian companies, and helps organization managers understand the influence of idiosyncratic deals on creative deviation so that they provide the grounds for creative deviation which is crucial for the development of modern corporations through the mediation of psychological entitlement and constructive voice.

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Positive Character Strengths can be defined as characteristics that allow an individual to function at their personal best. The strengths are especially important for knowledge acquisition and problem solving. Knowing the dimensions of character strengths is effective on business continuity and development. Therefore, this research aims to investigate the impact of positive character strengths to business continuity with the mediating role of resilience and moderating social responsibility in corona-drive conditions. The statistical sample of this research includes 240 managers of service businesses in Isfahan. In order to data collection, the questionnaire and convenience sampling method were used. The reliability and validity of the research constructs using Cronbach's alpha and average variance extracted (AVE) were confirmed. Research hypotheses were checked with the help of Smart PLS3 software. The results of the research showed that positive character strengths have a positive and significant effect on resilience. As well as, resilience has a positive and significant effect on business continuity. In order to promote the business continuity of through the positive character strengths, emphasis should be placed on resilience. Also, four important functions of character strengths; the virtues of wisdom, self-control, courage and excellence have a positive and significant effect on resilience. Two other functions of character strengths; the virtue of humanity and justice has no significant effect on resilience. It should be noted that the social responsibility-moderating variable does not moderate the relationship between resilience and business continuity in the Covid-19 era.

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Hexapod walking robots can be employed for both walking and manipulation purposes. When manipulating, they have 6 degrees of freedom for top platform, high rigidity, high load capacity, high speed, and accuracy. On the other hand, it is very well known that they have limited workspace when they are fixed in place for manipulation. Designing a hexapod robot resulting in a maximized workspace can greatly affect the efficiency of the robot when manipulating. Since radially symmetric hexapod walking robots can be modeled as three 2-RPR planar parallel mechanisms, we have used the methods and calculations that used in this kind of mechanism for designing a radially symmetric hexapod walking robot. In this paper, after a thorough review on existing methods for calculating and improving 2-RPR planar parallel mechanism workspace, an algorithm is presented, which results in a maximized reachable workspace. The merit of the method is that there is no need to calculate the workspace volume when maximizing the workspace volume. Also, following this algorithm is necessary for design of the maximized-workspace robot. In other words, the output of the presented optimization algorithm is a set of robot kinematic parameters, which guarantees the maximized volume of the robot’s reachable workspace.

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