Sharif Digital Repository

An analysis of carbon dioxide (CO2) removal process from synthesis gas has been carried out in this work. CO2 removals by physical and chemical solvents are the most often used. The most important factors that affect cost and performance of a CO2 recovery unit are the number of flash drum separation units, and the pressure drop pattern among them. Different variations of this process were simulated using Hysys software, and the capital and operational expenditures for these plants were estimated. The focus was to reach an optimum process to minimize the total unit cost of separated CO2. The results indicate that for a fixed number of separation units, the case with uniform pressure drop... 

The debate over innovativeness of large firms and SMEs, which was bolded by Schumpeter, still continues under mixed empirical evidences. There are several implications for this debate including policy orientation in support of large firms or SMEs. But there is a scarce of studies in developing countries and no such study in Iran yet. The present study has explored the proportionality of increase of innovation activity versus firm size within 522 Iranian knowledge-based firms categorized in 9 industries. Innovation activity was measured by R&D expenditure while firm size stood for number of employees. Using log–log regression in the first phase, it was found that R&D expenditure confirms a... 

We investigate the problem of energy-efficient resource allocation constrained to quality of service and physical requirements in orthogonal frequency division multiplexing (OFDM)-based elastic optical networks and propose a fast two-stage algorithm to solve it. The first stage of the proposed algorithm deals with routing, traffic grooming, and traffic ordering and mainly aims at minimization of the number of deployed optical amplifiers and transponders. We provide an integer linear program for routing and traffic grooming and propose a heuristic procedure, which yields its near-optimum solution in a shorter runtime. In the second stage, we optimize transponder parameters to minimize total... 

The major objective of this study is to provide an analytical tool to identify the role of investment on innovation in the process of new technologies development. To achieve this goal, a model of knowledge flow is developed and the effects of national and international knowledge spillovers are investigated. Results show that when knowledge spillovers are modelled in the Nordic countries, the required investment on domestic energy R&D decreases and the cumulative knowledge increases to 10.7 billion USD by 2030. This is a significant economic potential for technological innovation which can be considered for both energy researchers and energy planners. Finally, some important policy insights... 

Energy innovation is a key requirement to limit global warming and tackle climate change in the years to come. A better understanding of the public R&D mechanism is likely to improve allocation of resources for energy innovation. Thus, the present paper evaluates the impacts of public R&D and knowledge spillovers on the development of renewable energy sources. To achieve this goal, knowledge flow has been modeled as a function of public R&D expenditures, cumulative knowledge stocks and knowledge spillovers. To show the application of the model, the Nordic countries as one of the pioneers in renewable technologies have been chosen. Results show the cumulative knowledge stock will increase to... 

Background: Comprehensive and comparable estimates of health spending in each country are a key input for health policy and planning, and are necessary to support the achievement of national and international health goals. Previous studies have tracked past and projected future health spending until 2040 and shown that, with economic development, countries tend to spend more on health per capita, with a decreasing share of spending from development assistance and out-of-pocket sources. We aimed to characterise the past, present, and predicted future of global health spending, with an emphasis on equity in spending across countries. Methods: We estimated domestic health spending for 195... 

Purpose: The purpose of this paper is to examine cigarette consumption behavior of younger cohorts in the urban and rural areas of Iran. The authors use Iran’s annual Household Income and Expenditures Surveys (HIES) database over 2007–2013 for the statistical analysis. In order to control for a large number of households with zero expenditure on cigarette consumption, the authors have used the double-hurdle modeling approach for counting the outcomes of interest. The authors have also limited the sample to cases in which the head of household is between the ages of 21 and 45 and all children are younger than 18. Design/methodology/approach: In this study, the authors have conducted a... 

The current transition to a greener economy affects world markets dynamics. Given the considerable hydrocarbon dependency, we scrutinise the resilience of the Russian fiscal stance to international oil and gas prices at the first phase of this study. In doing so, we apply Cross-Quantilogram and Dynamic Simulated Autoregressive Distributed Lags (DSARDL) to analyse time-series data from January 2011 to August 2021. Our investigation demonstrates the fiscal stance (FS) positively responds to positive oil price shocks at medium quantile of FS and at lower to the higher quantile of oil price. The degree of responsiveness of FS to oil price is profound in the medium memory due to the time lag of... 

To meet the requirements of the emerging applications, future networks must transmit multiple class of services traffic with diverse quality of service (QoS) requirements. In this paper, we formulate an integer linear programming (ILP) to design multilayer internet protocol (IP) over elastic optical networks (EONs), IP-over-EONs to support multi-class services with different latency and availability requirements. The objective of the ILP is to minimize capital expenditure (CAPEX) and spectrum usage while satisfying all QoS constraints in terms of latency and survivability mechanism. Furthermore, a heuristic algorithm is proposed to solve this problem in large-scale networks. We compare the...