Locked into Copenhagen pledges - Implications of short-term emission targets for the cost and feasibility of long-term climate goals

Riahi, K.,Kriegler, E.,Johnson, N.,Bertram, C.,den Elzen, M.,Eom, J.,Schaeffer, M.,Edmonds, J.,Isaac, M.,Krey, V.,Longden, T.,Luderer, G.,Mejean, A.,McCollum, D.L.,Mima, S.,Turton, H.,van Vuuren, D.P. American Elsevier 2015 TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE Vol.90 No.1

This paper provides an overview of the AMPERE modeling comparison project with focus on the implications of near-term policies for the costs and attainability of long-term climate objectives. Nine modeling teams participated in the project to explore the consequences of global emissions following the proposed policy stringency of the national pledges from the Copenhagen Accord and Cancun Agreements to 2030. Specific features compared to earlier assessments are the explicit consideration of near-term 2030 emission targets as well as the systematic sensitivity analysis for the availability and potential of mitigation technologies. Our estimates show that a 2030 mitigation effort comparable to the pledges would result in a further ''lock-in'' of the energy system into fossil fuels and thus impede the required energy transformation to reach low greenhouse-gas stabilization levels (450ppm CO<SUB>2</SUB>e). Major implications include significant increases in mitigation costs, increased risk that low stabilization targets become unattainable, and reduced chances of staying below the proposed temperature change target of 2<SUP>o</SUP>C in case of overshoot. With respect to technologies, we find that following the pledge pathways to 2030 would narrow policy choices, and increases the risks that some currently optional technologies, such as carbon capture and storage (CCS) or the large-scale deployment of bioenergy, will become ''a must'' by 2030.

Determination of Heavy Metal Content in Astacus leptodactylus caspicus of Anzali Wetland, lran

Riahi, A.R,M.Sh. Fazeli,M. Paydar 한국생태학회 2004 Journal of Ecology and Environment Vol.27 No.1

Efficient in vitro regeneration of the endangered species Artemisia arborescens L. through direct organogenesis and impact on secondary metabolites production

Riahi Leila,Chograni Hnia,Ben Rejeb Fedoua,Ben Romdhane Meriam,Masmoudi Ahmed Slaheddine,Cherif Ameur 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.3

Tree wormwood (Artemisia arborescens L.; family Asteraceae) is an endangered medicinal and ornamental plant with industrial and ecological potentials. Here, we report an efficient micropropagation method for the in vitro regeneration of this species. Initiation culture was established from nodal segments in basic Murashige and Skoog (MS) medium. Shoot induction and elongation were assessed in MS medium supplemented with different concentrations of 6-benzylaminopurine (BAP; 0–1.5 mg/L) in combination with indole 3-acetic acid (IAA; 0–0.4 mg/L). The growth regulators combination of 0.5 mg/L BAP + 0.1 mg/L IAA gave the best result with a 100% shoot induction rate and morphologically stable vitroplants without callogenesis. The half-strength MS medium supplemented with 1 mg/L indole 3-butyric acid (IBA) resulted in the highest rooting rate, the maximum root number, and the highest root length. Rooted plantlets were successfully acclimatized with a 70% survival rate. The phytochemical analyses revealed enhanced total phenolic and flavonoid contents in the micropropagated plants compared to the mother plant. However, no significant fluctuations were recorded for the condensed tannins and essential oil contents between the micropropagated plants and the mother plant. The GC-MS analysis revealed that, except for some minor compounds which showed significant variation between the in vitro regenerated plants and the mother plant, contents of the main essential oil components were unchanged. This simple and rapid in vitro regeneration protocol through direct organogenesis could be applied both for ex situ and in situ conservation programs and for the sustainable production of tree wormwood bioactive phytochemicals.

Marble wastes as amendments to stabilize heavy metals in Zn-Electroplating sludge

Riahi, Khalifa,Chaabane, Safa,Thayer, Bechir Ben Techno-Press 2017 Advances in environmental research Vol.6 No.1

Powdered marble wastes (PMW) generated by Utique marble cutting industries (North of Tunisia) with abundant amounts were used in this study as low-cost materials to investigate the stabilization of heavy metals (Pb, Zn, Fe) in sludge generated from a local Zn-Electroplating factory. Powdered marble wastes were evaluated by means of chemical fractions of heavy metals in sludge and concentrations of heavy metals in leachate from columns to determine their ability to stabilize heavy metals in contaminated sludge. Results indicated that chemical fractions of heavy metals in sludge were affected by application of the PMW mineral materials and pH, however, the effects varied with heavy metals. Application of the powdered marble wastes mineral materials reduced exchangeable metals in the sequence of Pb (60.5%)>Fe (40.5%)>Zn (30.1%). X-ray diffraction and hydro-geochemical transport code PHREEQC analysis were successfully carried out to get a better understanding of the mechanisms of reactive mineral phases involved in reduced exchangeable heavy metals in sludge after PMW material amendments. Therefore, metal immobilization using powdered marble wastes materials is an effective stabilization technique for industrial metallic hydroxide sludge.

Determination of Heavy Metal Content in Astacus leptodactylus caspicus of Anzali Wetland, Iran

Riahi, A.R.,Fazeli, M.Sh.,Paydar, M. The Ecological Society of Korea 2004 Journal of Ecology and Environment Vol.27 No.1

With attention to different human activities around Anzali wetland and introduction of different pollutants containing heavy metals into this water ecosystem and absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native benthose of Anzali wetland and enjoys food and economic importance; Sampling of waters and sediments from 18 stations and shell and muscle of Astacus leptodactylus from 5 stations had been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples by using international and standard methods and then their heavy metals content was determined by Atomic Absorpotion Spectrophotometer (AAS), model P.U 9400 philips. Result of the analysis stated that; 1) The mean values of Cr, Zn, Pb, Ni, V in Anzali waters were 6.4, 184.5, 28.8, 28.9, 47.1 ($\mu$ gr/lit) respectively, which comparing to the international standards, is not suitable for drinking, but it can be used for agricultural and aquacultural purposes. Even though the concentration of heavy metals in sediments were high, there are in range of acceptable limit for aquatics organisms; 2) Comparatively, the concentration of heavy metals in shell and muscle of Astacus leptodactylus in Anzali wetland (Cr, Zn, Pb, Ni, V in shell were 3.48, 109.3, 14.13, 7.17, 36.2 and in muscle were 2.98, 131.98, 3.12, 4.77, 9.05 ppm respectively) were more than what is determined for Aras dam (in shell were 1.6, 224.3, 7.8, 7.6, 10.3 and in muscle were 1.4, 60.2, 0.45, 2.7, 4.4 mg/kgr respectively); 3) For all samples, concentration of heavy metals in all Astacus leptodactylus in Anzali wetland and Aras dam, was at tolerance level for human consumption; 4) There was no association with significant difference between weight and size of Astacus leptodactylus with absorption and accumulation of heavy metals; but there was a significant association between heavy metals content in water and in sediments, and in sediments, shell and muscle of Astacus leptodactylus in Anzali wetland.

Autophagy is a major regulator of beta cell insulin homeostasis

Riahi, Yael,Wikstrom, Jakob D.,Bachar-Wikstrom, Etty,Polin, Nava,Zucker, Hava,Lee, Myung-Shik,Quan, Wenying,Haataja, Leena,Liu, Ming,Arvan, Peter,Cerasi, Erol,Leibowitz, Gil Springer-Verlag 2016 Diabetologia Vol.59 No.7

<P>Aims/hypothesis We studied the role of protein degradation pathways in the regulation of insulin production and secretion and hypothesised that autophagy regulates proinsulin degradation, thereby modulating beta cell function. Methods Proinsulin localisation in autophagosomes was demonstrated by confocal and electron microscopy. Autophagy was inhibited by knockdown of autophagy-related (ATG) proteins and using the H+-ATPase inhibitor bafilomycin-A1. Proinsulin and insulin content and secretion were assessed in static incubations by ELISA and RIA. Results Confocal and electron microscopy showed proinsulin localised in autophagosomes and lysosomes. Beta-Atg7(-/-) mice had proinsulin-containing sequestosome 1 (p62 [also known as SQSTM1])(+) aggregates in beta cells, indicating proinsulin is regulated by autophagy in vivo. Short-term bafilomycin-A1 treatment and ATG5/7 knockdown increased steady-state proinsulin and hormone precursor chromogranin A content. ATG5/7 knockdown also increased glucose- and non-fuel-stimulated insulin secretion. Finally, mutated forms of proinsulin that are irreparably misfolded and trapped in the endoplasmic reticulum are more resistant to degradation by autophagy. Conclusions/interpretation In the beta cell, transport-competent secretory peptide precursors, including proinsulin, are regulated by autophagy, whereas efficient clearance of transport-incompetent mutated forms of proinsulin by alternative degradative pathways may be necessary to avoid beta cell proteotoxicity. Reduction of autophagic degradation of proinsulin increases its residency in the secretory pathway, followed by enhanced secretion in response to stimuli.</P>

Simulation Study for a UV Water Disinfection Unit Powered by a Photovoltaic System

Riahi, Said,Mami, Abdelkader,Minzu, Viorel International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.1

This work presents a simulation model for a specific UV disinfection system (UVDS) powered by a Photovoltaic System. The global UVDS also includes the electronic converters, Electronic Ballast, UV Lamp and Motor Pump. The equations that model the physical components' behaviour are connected to obtain a dynamic global model. The latter is converted in a Simulink/Matlab model, which allows to carry out simulation series concerning the entire UVDS. The physical parameters: the irradiation G and the temperature T, are considered as inputs. series of measurements carried out in order to show how these parameters affect the current, the voltage of the PVs and especially the value of the current of the UV lamp, on the other hand a study on the behavior and the evolution of the parameters of the motor pump such as the armature current, motor torque, speed of rotation and the water flow. The purpose of all this is to realize how important are the two parameters concerning the lamp current and the water flow because they are two very important factors to keep an adequate water quality.

The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview

Riahi, Keywan,van Vuuren, Detlef P.,Kriegler, Elmar,Edmonds, Jae,O’Neill, Brian C.,Fujimori, Shinichiro,Bauer, Nico,Calvin, Katherine,Dellink, Rob,Fricko, Oliver,Lutz, Wolfgang,Popp, Alexander,Cuaresm Elsevier 2017 Global environmental change Vol.42 No.-

<P><B>Abstract</B></P> <P>This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 400–1200 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO<SUB>2</SUB> emissions of the baseline scenarios range from about 25 GtCO<SUB>2</SUB> to more than 120 GtCO<SUB>2</SUB> per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: (1) the policy assumptions, (2) the socio-economic narrative, and (3) the stringency of the target. The carbon price for reaching the target of 2.6W/m<SUP>2</SUP> that is consistent with a temperature change limit of 2°C, differs in our analysis thus by about a factor of three across the SSP marker scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectoral extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6).</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present an overview of the Shared Socioeconomic Pathways (SSPs), which were developed as a community effort over the last years. </LI> <LI> The SSPs comprise five narratives and a set of driving forces. </LI> <LI> Our SSP scenarios quantify energy and land-use developments and associated uncertainties for greenhouse gas and air pollutant emissions. </LI> <LI> We conduct an SSP mitigation analysis, and estimate mitigation costs. We find that very low climate targets might be out of reach in SSPs featuring high challenges. </LI> <LI> The SSPs are now ready for use by the climate change research community. </LI> </UL> </P>

Shear Buckling Analysis of Steel Flat and Corrugated Web I-girders

Farhad Riahi,Alaeddin Behravesh,Mikaeil Yousefzadeh Fard,Arastoo Armaghani 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.12

One of the parameters of the economic design of steel I-girders is the use of thin webs. However, in large spans, the use of deep Igirders with thin web leads to the buckling of the web. In order to achieve out-of-plane stiffness and shear buckling resistance without the use of stiffeners or increasing the thickness of the webs, one possible way is to use corrugated plates in the I-girder web. To understand, shear stress distribution of the web a series of three-point load test was performed on four types of the web; (flat, trapezoidal-, sinusoidal-, and the zigzag-corrugated). A non-linear FE analysis method was used to obtain the shear stress distribution in a flat and corrugated web, since it was not possible to obtain the shear stress distribution from the experimental investigation. Based on this research, it was found that the main failure modes of the current models are yielding or shear buckling of the web when it is under the shear. In addition, it shows that the failure of all beams occurred due to shear buckling of the web without any interaction of the flange. In the other hand, the shear stress along the side of the flange is nearly zero; it is clear that the web takes almost all the shear force. The nonlinear analysis results show that shear stress is maximum and uniformly distributed on the web before the buckling. After buckling, the volume of shear stress is reduced and distributed unevenly.According to the results, there are three types of shear buckling: local, global, and interactive in models.

The effect of Al₂O₃ on physical & electrical properties of ZnO varistors

N. Riahi-Noori,A. Mehdikhani,A. M. Hadian,R. Sarraf-Mamoory 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.2

In this paper, the effect of Al₂O₃ on physical and electrical properties of ZnO varistors was investigated. After adding different amounts of Al₂O₃ to ZnO varistors, green and fired density and 3-point bending strength were measured. Also, microstructural analysis was evaluated by SEM. Finally, the optimum values for nonlinear coefficient (α) and breakdown voltage were obtained as 50 and 638 v/cm respectively. In this paper, the effect of Al₂O₃ on physical and electrical properties of ZnO varistors was investigated. After adding different amounts of Al₂O₃ to ZnO varistors, green and fired density and 3-point bending strength were measured. Also, microstructural analysis was evaluated by SEM. Finally, the optimum values for nonlinear coefficient (α) and breakdown voltage were obtained as 50 and 638 v/cm respectively.