The Deterministic Capacity of Relay Networks with Relay Private Messages

We study the capacity region of a deterministic 4-node network, where 3 nodes can only communicate via the fourth one. However, the fourth node is not merely a relay since it can exchange private messages with all other nodes. This situation resembles the case where a base station relays messages between users and delivers messages between the backbone system and the users. We assume an asymmetric scenario where the channel between any two nodes is not reciprocal. First, an upper bound on the capacity region is obtained based on the notion of single sided genie. Subsequently, we construct an achievable scheme that achieves this upper bound using a superposition of broadcasting node 4 messages and an achievable "detour" scheme for a reduced 3-user relay network.Comment: 3 figures, accepted at ITW 201

Oil Demand, Supply, andMedium-Term Price Prospects:A Wavelets-Based Analysis

The global “great recession” was precipitated in part by record high prices of oil and other commodities. Previous severe recessions have typically resulted in significantly lower energy prices, which in turn spurred growth and fueled a healthy recovery. In part due to expansionary monetary policies worldwide, oil prices have remained relatively high, making it difficult for the global economy to stage a strong recovery. The result is a short-to-medium term forecast of weak to modest growth, which – combined with continuously falling energyintensity of GDP – means that oil demand will remain stagnant or at best grow modestly. Under these circumstances, surging supply from U.S. shale and similar technologically-driven unconventional oil sources is likely to create excess supply and put strong downward pressure on oil prices. Voluntary reduction in oil production to prevent falling prices is highly unlikely, because swing producer Saudi Arabia and other GCC countries need revenues at the level of current volumes and prices in order to meet core budgetary requirements and prevent regime-change risk in the aftermath of “Arab Spring” revolts. Our wavelet analysis of all countries that have ever produced more than one million barrels of oil per day shows that regime change by itself would not result in significant reduction in oil production – although it may result in lower investment and therefore prevention of further increase in production capacity. However, war that destroys physical installations for the production and/or transport of oil can significantly disrupt oil supplies. In sum, if the outright war scenario is excluded, we expect prices to fall precipitously in the medium term (3-5 years). However, the continued threat of currently-contained civil wars into larger confrontations can maintain the current prices, especially if unprecedented monetary easing continues

Chronic posttraumatic pseudoaneurysm of the thoracic aorta 55 Years after a blunt trauma - A case report with review of literature

Injuries of thoracic aorta due to blunt trauma carry very high mortality rates and studies estimated that less than 2% of people who sustain it remain alive if they were not diagnosed and treated appropriately. Moreover, even those lucky few live with the risk of rupture of the Pseudoaneurysm that can develop years to decades after the causative trauma culminating in the fatal internal hemorrhage. This paper reports a case of a 72-years-old Libyan male who sustained a blunt chest injury and multiple rib fractures 55 years ago that resulted in a large pseudoaneurysm of the arch of aorta

Stabilization of active acetylene by-product via sequestration of co\u3csub\u3e2\u3c/sub\u3e

© 2020 Taylor & Francis Group, London, UK. The rising rates of carbide lime waste (CLW), the by-product of acetylene production, cause environmental problems and need for the repurposing of the said material. The high content of calcium in such by-products (60–80%) is the main reason for its utilization in CO2 sequestration. This study focused on using of CLW to form simple, reliable, cost-efficient process, applying direct solid-liquid-gas carbonation reaction, which consists of bubbling CO2 gas through an aqueous slurry of slaked CLW with different solid /water ratios. The experimental conditions were adjusted for maximum carbonation efficiency. Experimental results indicated that CLW has the potential to store CO2 in the form of stable carbonates. Considering the total calcium content, an amount of 0.5833 kg CO2 /kg CLW was achieved. The influence of solid/water ratio on the precipitation of calcium carbonate was investigated using SEM that showed a difference in crystal carbonate sizes and morphologies

Design, Engineering Analysis, and Fabrication of a Prototype Electromechanical Finger Fixator Control System

This paper investigates a new external fixator system for treating finger contractures. This innovative system is electric and user-friendly, providing precise readings of the angles of diseased finger joints. Accurate measurements of the angles of the diseased finger joints can assist therapists and patients during rehabilitation procedures. The fixator consists of ten parts assembled using polyether-ether-ketone (PEEK) for the plastic components and stainless steel for the metal components. The design model was engineered, drawn, and analyzed using SolidWorks Computer-Aided Design software. The verification process utilizes finite element analysis to demonstrate that the maximum stress was lower than the yield strength of the chosen materials. As a result, the new device design is robust and stable enough to withstand the anticipated loading conditions of human fingers. Subsequently, a prototype was fabricated using advanced additive manufacturing technology, specifically fused deposition modeling (FDM). The proposed fixator is simple to control, reliable, easy to use, and reproducible. It enables device users to exercise their finger joints throughout the day without requiring the assistance of specialists

Rheology Of Cement Paste Containning Chemical Admixtures

Understanding the Rheology of cement and water is a not a simple task since, thebehaviour of complicated system varies with time and there is still a great deal of work to bedone before, it is properly understood. In this study, we used a new simple and cheaptechnique to evaluate flow properties of cement paste .This technique is based on dropping aneedle from a constant height. The penetration depth is measured at different circumstances,different w/c ratios, different types of super plasticizer, and different percentage of admixturefor two types of cement types of cements OPC type V (CEMEX) and OPC type I (HELWAN)were considered in this study. Also, effect of retempering on penetration depth were alsoconsidered. Finally effect of variation of needle drop height was also considered. Thepenetration depth technique proved to be effective in monitoring the effect ofsuperplasticizer/cement ratio percentage, effect of time, manual remixing after 30 minutesand needle drop height on the rheological behavior of different types of cement paste, whichfurther proves the effectiveness of this method in evaluation of cement paste Rheology