Alternative Liquid Assisted-Sintering of AL/CU Composites Using Selective Powders of AS-Cast Al-ZN Alloy

Al and its alloys constitute one of the most versatile, economical and attractive materials for a wide range of applications. The 7xxx and 2xxx series alloys are those of achieving the highest mechanical strength among aluminum alloys. In this investigation, using powder metallurgy provides the microstructural and mechanical properties characterizations of non-commercial Al6Cu5Zn alloy by using powder metallurgy. Initial powder sizes are determined and the best condition is obtained for the distribution comprised between 75-106 μm. The samples are sintered at 585 oC, 600 oC and 615 oC during 0.5, 1.5 h and 3 h. It is found that mechanical behavior similar to as-cast Al-Cu based alloys is attained (~ 125 MPa) when the samples at 615 oC during 3 h are sintered. Considering the reduction of energy consumption and metal fumes commonly produced in foundry, Al-Zn powder can be used with Al and Cu elemental powders to constitute an Al6Cu5Zn alloy.

ENERGY EFFICIENT SOLUTIONS IN INFRASTRUCTURE PROJECTS OF SORTING COMPLEXES OF RAILWAY STATIONS

Purpose. Improving approaches and methods of calculation and design of energy-efficient sorting slides of railway stations, taking into account the mechanization of their braking positions based on the use of modern car moderators, including energy efficient structures. Methodology. The research was performed using the methods of the theory of bitter calculations in combination with the tools of mathematical statistics and probability theory. The assessment of the possible economic effect was carried out taking into account the technical and economic calculations on the criterion of the given savings of annual costs. Results. An estimate of the predicted value of the speed of the very good runner at the entrance to the brake positions when calculating their needs. An adaptive approach to the calculation of the required power of the 1st and 2nd brake positions on the descent part of the sorting slides is proposed. The condition of technological reliability and "survivability" of the system of control of speeds of movement of couplings at rolling down from a sorting hill is checked taking into account action of probabilistic factors. The economic effect of reducing the need for car decelerators for the braking positions of the slides, as well as energy efficiency of sorting complexes. Practical value. The obtained important scientific and practical results to substantiate the reduction of energy consumption and increase the energy efficiency of sorting stations can be used to develop new projects and to survey the parameters of existing sorting complexes, including non-mechanized slides.

Analysis of technologies for preparing herbal flour

В рамках данной работы проанализированы общие принципы реализации процесса приготовления травяной витаминизированной муки. Объектом данного исследования является технологический процесс приготовления данного концентрированного сухого корма, в частности такие операции, как измельчение, сушка и помол растительного сырья. Предметом данного исследования является снижение затрат энергии на выполнение перечисленных операций. Регулярный спрос на данный продукт и недефицитность сырья, делает актуальной задачу по снижению общей себестоимости продукции путем снижения затрачиваемых мощностей. Цель проводимого исследования заключается в поиске способа снижения затрат энергии для приготовления травяной муки. Исследование проводилось путем анализа принципов работы существующей аппаратуры и перспективных разработок, выявлялись преимущества и недостатки технических решений, а также основные противоречия, препятствующие увеличению эффективности при изменении параметров работы. По итогам анализа сформулирована основная концепция развития технологического процесса, описаны противоречия, препятствующие ее реализации. Результаты работы применимы в дальнейших прикладных научно-исследовательских работах и опытно-конструкторских разработках по созданию аппаратуры для приготовления травяной муки и аналогичных сухих кормов, перевооружению и реорганизации данных производств. В результате проведенной работы выяснено, что только изменение принципа работы аппаратуры позволит добиться увеличения эффективности технологического процесса производства. Изменение режимов работы существующей аппаратуры не позволяет поднять эффективность процесса в целом, так как возрастает потребность в энергии у процессов, сопутствующих основному. This work is aimed at analyzing the general principles of the implementation of the process of preparing herbal vitaminized flour. The object of this study is the technological process of preparing this concentrated dry feed, in particular, such operations as grinding, drying and milling plant materials. The subject of this study is the reduction of energy consumption for the performance of the listed operations. The demand for this product and the abundance of raw materials makes the task of reducing the cost of production and energy costs actual. The aim of this research is to find a way to reduce energy costs for making herbal flour. The study was carried out by analyzing the principles of operation of the existing equipment and promising developments; the advantages and disadvantages of technical solutions, as well as the main contradictions that hinder the increase in efficiency when changing the operating parameters, were revealed. Based on the analysis results, the main concept of the technological process development was formulated, the contradictions that hinder its implementation were described. The results of the work are applicable in further applied research and development work on the creation of equipment for the preparation of grass meal and similar dry fodder, re-equipment and reorganization of these industries. As a result of the work carried out, it was found that only a change in the principle of operation of the equipment will increase the efficiency of the production process. Changing the operating modes of the existing equipment does not allow to increase the efficiency of the process as a whole, since the demand for energy in the processes accompanying the main one increases.

Asymmetric electrode geometry induced photovoltaic behavior for self-powered organic artificial synapses

Optoelectronic synapses have attracted considerable attention because of their promising potential in artificial visual perception systems for neuromorphic computing. Despite remarkable progress in mimicking synaptic functions, reduction of energy consumption of artificial synapses is still a substantial obstacle that is required to be overcome to promote advanced emerging applications. Herein, we propose a zero-power artificial optoelectrical synapses using ultrathin organic crystalline semiconductors, which can be self-driven by exploiting the photovoltaic effect induced by asymmetric electrode geometry contacts. The photogenerated charge carrier collection at the two electrodes is unbalanced due to the asymmetric contacts, leading to the in-plane current without bias voltage. Our devices successfully mimic a range of important synaptic functions, such as paired-pulse facilitation (PPF) and spike rate-dependent plasticity (SRDP). Furthermore, we demonstrate that our devices can realize the simulation of image sharpening under self-driven optical-sensing synaptic operations, offering prospects for the development of retinomorphic visual systems.

Investigation of fabric movement in a tumble dryer for the development of drying methods for wool fabrics to save energy

Tumble dryers are widely used for drying garments, but felting shrinkage can be caused to wool garments during the tumble drying process. To dry wool fabrics or garments in tumble dryers, the flat dry function has been introduced in the dryers; however, the energy efficiency is very low. The current study investigated fabric movement at different rotation speeds in the tumble dryer and their resultant performances in terms of specific moisture extraction rate, evenness of drying, fabric shrinkage, and fabric smoothness. For shrink-resist-treated wool fabrics, tumble drying at the rotation speed to keep fabric movement in projectile motion accompanied with occasional tumbling could achieve better energy efficiency, drying uniformity, and fabric smoothness. For untreated wool fabrics, introducing vertical movement to the flat dry in the tumble dryer can improve the heat exchange between the fabric and hot air, resulting in an increase in energy efficiency of approximately 30% compared with motionless flat drying. Wool fabric shrinkage can be controlled at less than 2% with the smooth appearance of fabric at grade 3.5 after drying under the recommended drying condition. This study could help tumble dryer manufacturers design optimal drying methods for wool fabrics with the potential for the reduction of energy consumption.

Reduction of Energy Consumption for Water Wells Rehabilitation. Technology Optimization

Groundwater wells are widely used in the energy sector, including for drinking water supplies and as water source wells in the oil and gas industry to increase production of natural gas and petroleum. Water well clogging, which can happen to any well for various reasons, is a serious problem that can lead to increased power costs due to a higher head to the pump, a reduction in the flow rate and various drawdown issues. If rehabilitation procedures do not take place in time, this can result in permanent loss of the well, and a new well must be drilled, which is not a sustainable approach. Rehabilitation methods for water wells usually include mechanical and chemical treatments, and even though these methods are well established and have been used for many years we can still observe many abandoned wells which could be rehabilitated. In this study, sets of cavitation generators are developed and used in combination with common conic hydrodynamic nozzles. This combination reduces the pressure in the system and makes the cleaning setup much lighter and more mobile. The designed nozzles were successfully used in hydrodynamic cleaning of four water wells.

Energy Retrofit. A Case Study—Santi Romano Dormitory on the Palermo University

Electrical and thermal consumption related to buildings, whether civil, commercial, public, or of any other kind, is very much in focus today. With today’s targets for energy savings, reduction of consumption, and environmental impact, it is necessary to carry out energy retrofits to modernize installations and their management. The realization of an effective improvement requires a careful analysis of the case study because each category of building has different requirements such as different load profiles and different installations and needs. This was carried out by studying the electrical and thermal load profiles. A good initial energy audit can provide the retrofit solutions capable of achieving the reduction of energy consumption and the emission of climate-changing gases into the atmosphere. A case study, carried out by the Department of Engineering of Palermo, showed how it is possible to perform an energy retrofit to modernize the energy system of the student dormitory at the University of Palermo. The paper presented a study carried out by programming a series of interlinked calculations in Microsoft Excel. In order to quantify the energy savings of the structure under examination, it is necessary to enter some input data, thanks to which all the formulas implemented in the calculation software were automatically completed. The programming of the calculations makes it possible to carry out an energy retrofit with interventions on the building envelope and the installations. The desire to program an automated calculation by modifying only the input data is intended to replicate a study on other buildings with the same peculiarities. In this way, it is possible to verify which retrofit hypotheses would be useful to upgrade old public administration buildings. In the analyzed case study, 65% of electrical energy and 33% of thermal energy could be saved by replacing generation systems, installing a co-generator, replacing windows, and replacing lamps with LED ones.

Reduction of Energy Consumption for Tire Test Room

This article presents a software-implemented 3-dimensional simulated analysis of a 4-tire test room and the 6-tire test room. The results of the average performance through the simulated analysis of 100 iterations were obtained. The simulation showed the temperature distribution in the test rooms. This objective of this study was to assess the efficiency of the start-up process in each test room and to find the most efficient setup. A promising improvement would be to install the heaters at the bottom of the room under the drums instead of at the ceiling. The results of the simulation will be compared to the data of temperature logging of the tire test rooms once there is availability upon the lifting of the Covid pandemic lockdown restrictions.

Energy Efficiency and Limitations of the Methods of Controlling the Hydraulic Cylinder Piston Rod under Various Load Conditions

The article is an overview of various methods of braking and controlling the movement of the piston rod under various load conditions. The purpose of this review is to systematize the state of the art in terms of efficiency, energy consumption and limitations of each method. The article discusses systems with different types of hydraulic actuators, operating under passive, active and variable load during the duty cycle of the piston rod. The existing literature was analysed in terms of applicability, reduction of energy consumption of the systems and even the possibility of energy return. Attention was paid to the costs and the need for additional power sources, as well as the problems and limitations of the presented methods. Based on the simulation model, energy consumption tests were carried out in systems with an actuator loaded with a variable force. There is a comparison of all methods in terms of actuator type, load, energy consumption and the possibility of energy recovery.