740 research outputs found
Study of Sea level changes with Leckie method of the Abderaz Formation (Middle Turonian-Early Campanian) at type section based on foraminifera
In this research the Abderaz Formation at its type section with an age of Turonian-early Campanian and a thickness of 300 m containing.light grey shale and marls was investigated. Statistical Studise of the morphotype groups of planktonic foraminifera shows that the majority of them are of shallow water forms (SWF) and deep water forms (DWF) and planktonic to benthic ratio is high indicating specific condition of oligotrophy and sedimentation in a relatively deeper marine conditio
Rapid Separation & Simultaneous Spectrophotometric Determination of U(VI) Using N-m- Tolyl-o-methoxybenzohydroxamic Acid
547-54
Optimal electricity supply system under Iranian framework limitations to meet its emission pledge under the Paris climate agreement
As part of its Paris Agreement commitment, Iran pledged to decrease 4 percent of its carbon dioxide (CO2) emissions from 2020 to 2030. About 29% of total emission in Iran belongs to electricity supply while energy consumption in other sectors (transport, household, and industry) have a lower share in CO2 emission. The main concern here is finding the optimal mix of power plants in the electricity supply system that should be deployed to meet Iranās mentioned respective targets. So, we developed a non-linear mathematical programming model for Iranās electricity system to address this concern. Results show that a 10-20% diffusion of renewable energy and converting gas turbine power plants to gas combined cycle technology with 5% annual rate can satisfy Iranās emissions pledge under the Paris Climate Accord. Finally, this model has been run for years between 2017-2030. Four scenarios have also been prepared based on different Iranian Five-Year Development Plans
Clustering and Combining Pattern of High-Risk Behaviors among Iranian University Students: A Latent Class Analysis
Background: High-risk behaviors are increasing among young adults worldwide. We aimed to identify
university studentsā subgroups on the basis of high-risk behaviors and to assess the role of age, living
alone, religious beliefs, and parental support in the membership of specific subgroups.
Study design: A cross-sectional study
Methods: The study was conducted in Bushehr (the south of Iran) from November to December 2016.
The sample included 977 university students selected through random sampling. The data were
collected using a self-administered questionnaire. Then, latent class analysis was used to classify the
students.
Results: Totally, five latent classes were identified as follows: low risk, high risk, somewhat low risk,
hookah user, and very high risk. Notably, 7.7% and 2.5% of the students belonged to high risk and very
high risk classes, respectively. The results suggested the protective effect of familial support and
religiosity on high-risk behaviors.
Conclusions: This study indicated the co-occurrence of high-risk behaviors. The findings can be used
to plan and evaluate interventions by considering risk factors and protective factors in universities
The Effect of Van Dijk Discourse Strategies on Iranian EFL Learnersā Writing Proficiency
This study tried to improve the writing proficiency of Iranian EFL students utilizing an innovative model through implementing and operationalizing the principles of critical discourse analysis which was introduced by Van Dijkās (2000) well-known socio-cognitive model. To this end, 57 intermediate language learners studying English in language institutes for several years were selected as the participants of the study using a version of TOEFL test as the selected proficiency test. The included participants were randomly divided into two groups of experimental and controlāwith 28 students in experimental group (16 females and 12 males) and 29 students in control group (17 females and 12 males). Both groups went through a three-stage model (pre-writing, during-writing and post-writing). The teaching procedure on writing had some differences between the instruction provided for the experimental group and the instruction presented to the control group in which the experimental group received some instruction of some suitable discursive strategies, namely, comparison, example (illustration), explanation, repetition, reasonableness and context description. After instruction, two groups were asked to write on a topic and their compositions were scored using holistic scoring procedure in order to guarantee the high reliability. The results of the study showed the significant differences between the performances of the experimental and control groups which indicated to the efficiency of the CDA-oriented approach to teach writing skill. However, the result of the study showed non-significant differences between the performances of the two genders as well as the performances of females and males in each group
Asymptotic features of Hessian Matrix in Receding Horizon Model Predictive Control with Medium Sized Prediction Frames
In this paper, Receding Horizon Model Predictive Control (RH-MPC) having a quadratic objective function is studied through the Singular Value Decomposition (SVD) and Singular Vectors of its Hessian Matrix. Contrary to the previous work, non-equal and medium sized control and prediction horizons are considered and it is shown that the Singular Values converge to the open loop magnitude response of the system and singular vectors contain the phase information. Earlier results focused on classical formulation of Generalized Predictive Control (GPC), whereas, current work proves the applicability to modern formulation. Although, method can easily be extended to MIMO systems, only SISO system examples are presented
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