Enabling Technologies for Chemical Synthesis: I. Selective Microwave Heating; II. Synthesis and Regioselective Cyclotrimerizations of Tethered 1,6-Diynes

Reaction discoveries, method developments, and technology advancements lie at the heart of synthetic organic chemistry. These innovations are essential for creating and manipulating complex molecules, which are the building blocks of many important chemical compounds, including pharmaceuticals, materials, and agrochemicals. Here, we first describe new methods to prepare neopentylene-tethered (NPT) 1,6-diynes which are valuable substrates for reaction discovery and target-oriented synthesis, especially in benzannulation strategies toward illudalane natural products. NPT 1,6-diynes have been employed as coupling partners in cyclotrimerization reactions for the synthesis of highly substituted benzene rings which present a persistent challenge in chemical synthesis and are underrepresented scaffolds in medicinal chemistry. Using a cationic rhodium catalyst, regioselective diyne-alkyne cyclotrimerizations have been developed which can be manipulated by varying the functional handles on the coupling partners. This enables the concise syntheses of coprinol and several alcyopterosins as well as the first chemical synthesis of fomajorin D which have shown to have interesting biological properties. Apart from advancements in chemical reactions, novel discoveries regarding potential applications of selective microwave (MW) heating in organic synthesis will also be presented. We have designed and optimized a system comprising dipolar p-nitroanisole (pNA) and MW-transparent mesitylene (MES), wherein pNA solutes assemble into nano-sized polar agglomerates than can be selectively heated using MW energy. This system is used as a mixed solvent for aryl Claisen rearrangement of allyl naphthyl ether (ANE) which serves as a probe reaction for exploiting MW-specific thermal effects

The Effect of Humeral Short Stem Positioning, Humeral Head Contact, and Head Positioning on Bone Stress following Total Shoulder Arthroplasty

Uncemented humeral stems cause stress shielding which result in bone resorption when used in total shoulder arthroplasty (TSA). Shorter length stems show a decrease in stress shielding, however the effect of humeral short stem positioning and humeral head contact and positioning on bone stress is currently not known, hence CT-based tools and Finite Element (FE) methods are used to quantify the effects of the mentioned variables on bone stresses after TSA. Eight male cadaveric humeri were virtually constructed from computed tomography (CT) data, with a generic short humeral short stem as the implant. The results of this work show that central stem positioning is preferred, and that for humeral head contact, full contact with the humeral resection results in the smallest changes in bone stress and bone volume with resorption potential. For humeral head position, tradeoffs in terms of cortical and trabecular bone loading were observed for both positions investigated

A novel LMI-based robust model predictive control for DFIG-based wind energy conversion systems

summary:The optimal and reliable performance of doubly fed induction generator is essential for the efficient and optimal operation of wind energy conversion systems. This paper considers the nonlinear dynamic of a DFIG linked to a power grid and presents a new robust model predictive control technique of active and reactive power by the use of the linear matrix inequality in DFIG-based WECS. The control law is obtained through the LMI-based model predictive control that allows considering both economic and tracking factors by optimization of an objective function, constraints on control signal and states of system and effects of nonlinearities, generator parameter uncertainties and external disturbances. Robust stability in the face of bounded disturbances and generator uncertainty is shown using Lyapunov technique. Numerical simulations show that the proposed control method is able to meet the desired specification in active and reactive power control in the presence of varieties of wind speed and pitch angle

Steel Joint Consortium (Iran, Afghanistan, Russia, China, India and Germany) in Herat, and the Economic, Political and Security Impacts in the Region, by Futuristic Approach with an Emphasis on SWOT

Geopolitical weight has a direct relationship with the geopolitical prestige of the country in the global and regional system, which can increase the dignity and public reputation of the country among other larger, equal or smaller countries. The more credibility and dignity increases, the more provide new opportunities for visible or invisible power, to objectively and subjectively influence processes, decisions, actions and behaviors at different local, regional and global scales. The geopolitical position of eastern Iran, due to its proximity to the countries of central Asia and Afghanistan and its access to high-energy resources; its domination on the world's most important energy and commodity transfer pathways; the strategic location for the land locked countries in Central Asia, Caucasus and Afghanistan to access free waters, connecting China and the countries of Southeast Asia to Europe; and the formation of the KhafHerat-China triangle and the region as a gateway for east of the country. The formation of this consortium between relevant countries, particularly five powerful countries in the steel industry in Herat can be considered as a factor in the emergence of Iran's geopolitical power and expanding Iran's influence in the region and Central Asia. Generally, the presence of regional and trans-regional economic powers and the convergence of these countries in the formation of a joint consortium can create a massive geopolitical weight to prevent US threats .Although, this project shows a clear horizon, but there are definitely problems with this process to assess the strengths, weaknesses, threats and opportunities of the swot model, to better recognize the partnership environment. The research method in this paper is descriptiveanalytical and data collection is based on documentary-library method. In this research quantitative and qualitative resources are simultaneously used relative to the problem under discussion which is called mixed research method

An Improved Model Predictive Control Method to Drive an Induction Motor Fed by Three-Level Diode-Clamped Indirect Matrix Converter

In this paper, an improved model predictive control method is proposed to drive an induction motor fed by a three-level matrix converter. The main objective of this paper is to present a novel method to increase the switching frequency at a constant sampling time. Also, it is analytically discussed that increasing the switching frequency not only can decrease the motor current ripples, but it can also significantly reduce its torque ripples. Finally, this study demonstrates that reducing the motor current ripple will improve the quality of the supply current. To be the accurate model and validate the motor drive system, a co-simulation method, which is a combination of FLUX and MATLAB software packages, is employed to find the simulation results. The findings indicate that the proposed method diminishes the THD of the supply current up to 26% approximately. Furthermore, increasing the switching frequency results in the torque ripple reduction by up to 10% almost