Search results
1 – 10 of over 5000Xie Xuejun, Yuanlin Zhang, Rui Wang, Yu Zhang and Mianzhao Ruan
The hollow copper wires of the generator are seriously corroded in cooling water. This paper aims to explore the mechanism of copper corrosion by thermodynamic calculation and…
Abstract
Purpose
The hollow copper wires of the generator are seriously corroded in cooling water. This paper aims to explore the mechanism of copper corrosion by thermodynamic calculation and kinetic experiments and to find out the precise pH range for preventing corrosion of copper in stator internal water and dual internal water cooled generators.
Design/methodology/approach
Thermodynamic and kinetic studies were carried out for the purpose of preventing the corrosion of hollow conducting copper wires in the internal cooling water. Thermodynamic calculation results demonstrate hollow copper wires electrochemically corroded by oxygen rather than acids (H+) and find out a precise anti-corrosion pH range. Kinetic experiments research on the effect of the pH value and oxygen concentration on corrosion and protection methods of copper in desalted water.
Findings
Research results demonstrate that, in the internal cooling water, hollow copper wires are electrochemically corroded by oxygen, rather than acids (H+). The method of preventing copper from corrosion in the desalted water is to control the pH value of the stator cooling water and the dual water inner cooling water between 7.86-8.86 and 7.86-9.26, respectively.
Originality/value
The thermodynamic calculation and potentiometric-pH diagram are used to obtain the accurate pH range of the inner cooling water and inner cooling water in the inner cooling water system. The kinetic experiments provide data support for the effect of temperature, pH value and oxygen concentration.
Details
Keywords
Ioannis A Kartsonakis, Elias P. Koumoulos, Antonis Karantonis, Costas A. Charitidis, S Dessypris and A Monos
The purpose of this paper is to perform the evaluation of copper susceptibility to corrosion in industrial cooling systems. Microstructure and defects of copper are observed…
Abstract
Purpose
The purpose of this paper is to perform the evaluation of copper susceptibility to corrosion in industrial cooling systems. Microstructure and defects of copper are observed, while divergences from optimum structure are discussed.
Design/methodology/approach
Various types of corrosion are examined. Electrochemical techniques such as electrochemical impedance spectroscopy and potentiodynamic polarisation are applied in these materials, using corrosion inhibitors. Microscopic observations and electrochemical measurements are interpreted according to possible mechanistic scenarios.
Findings
It is evident that, under specific conditions (e.g. high pH), water cooling ingredients can enhance corrosion, leading to significant copper mass loss from the inner surface of the pipe and thus leading to failure.
Originality/value
Evaluation of copper corrosion in cooling industrial systems was done, as well as studies of copper corrosion in sodium chloride.
Details
Keywords
Xie Xuejun, He Jie, Lv Ke and Pan Ling
The purpose of this paper is to study the inhibitive property of the mixture of an imidazole derivative (IMA) and benzotriazole (BTA) to the copper in deionised water.
Abstract
Purpose
The purpose of this paper is to study the inhibitive property of the mixture of an imidazole derivative (IMA) and benzotriazole (BTA) to the copper in deionised water.
Design/methodology/approach
Static mass‐loss tests, electrochemical tests and surface analysis are used to study the inhibitive property of the mixture of an IMA and BTA to copper in deionised water.
Findings
There is a synergistic inhibitive effect on inhibition of the copper by the IMA and BTA in deionised water, and the mixture of the IMA and BTA is an effective inhibitor that mainly hinders the anode reaction.
Practical implications
The mixture of the IMA and BTA is an effective inhibitor and can be used to prevent copper from corrosion in deionised water.
Originality/value
The mixture of the IMA and BTA is an effective inhibitor and should be suitable for use in the cooling water of an electricity generator unit to prevent corrosion of the copper conductors.
Details
Keywords
V. Nemkov, R. Ruffini, R. Goldstein, J. Jackowski, T.L. DeWeese and R. Ivkov
The purpose of this paper is to continue studies previously reported with the primary focus of optimizing an inductor design. The potential benefits of hyperthermia for cancer…
Abstract
Purpose
The purpose of this paper is to continue studies previously reported with the primary focus of optimizing an inductor design. The potential benefits of hyperthermia for cancer therapy, particularly metastatic cancers of the prostate, may be realized by the use of targeted magnetic nanoparticles that are heated by alternating magnetic fields (AMFs).
Design/methodology/approach
To further explore the potential of this technology, a high‐throughput cell culture treatment system is needed. The AMF requirements for this research present challenges to the design and manufacture of an induction system because a high flux density field at high frequency must be created in a relatively large volume. Additional challenges are presented by the requirement that the inductor must maintain an operating temperature between 35 and 39°C with continuous duty operation for 1 h or longer. Results of simulation and design of two devices for culture samples and for in vitro tests of multiple samples in uniform field are described.
Findings
The inductor design chosen provides a uniform distribution of relatively high magnetic field strength while providing an optimal reduction in the voltage and power requirement. Through development of design and selection of magnetic concentrator, the exposure of the cell cultures to the heat generated by the inductor is minimized.
Originality/value
This method of generating uniform high AC magnetic fields in a large volume is beneficial for the study of hyperthermia in cells for a high throughput, necessary for cancer treatment research.
Details
Keywords
The purpose of this study is to examine the relationships between changes in water efficiency, profit and risk for firms in the global Consumer Packaged Goods industry. This study…
Abstract
Purpose
The purpose of this study is to examine the relationships between changes in water efficiency, profit and risk for firms in the global Consumer Packaged Goods industry. This study also aims to consider the moderating effect of operational efficiency on those relationships.
Design/methodology/approach
Using a sample of 155 firms with annual corporate social performance and financial performance data from Bloomberg for the years 2010–2019, this study employs first-differencing panel regression models to obtain our results.
Findings
This study finds strong evidence that operational efficiency moderates the relationships between water efficiency, profit and risk. For operationally efficient firms, increasing water efficiency increases profit and reduces risk. But for firms that are not operationally efficient, this study finds the opposite effects. These findings suggest a threshold level of operational efficiency that firms should achieve before they can reap financial benefits from increases in water efficiency.
Originality/value
Despite the increasing importance of water efficiency as a measure of corporate social performance, its effects on financial performance are not well studied. The relationship between operational efficiency and water efficiency has also not been examined. This work provides empirical evidence to better understand these important relationships. The major implication for managers is that operational efficiency is a foundational capability that should be developed before focusing on efforts to improve water efficiency. For operationally efficient firms, improvements in water efficiency can be an important mechanism to increase profitability and reduce risk.
Details
Keywords
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the United States National…
Abstract
Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.
Ebubekir Çantı and Mustafa Aydın
The purpose of this paper is to characterize the effects of different micro particle reinforcement with same weight ratio in acrylonitrile-butadiene-styrene (ABS) feed-stocks for…
Abstract
Purpose
The purpose of this paper is to characterize the effects of different micro particle reinforcement with same weight ratio in acrylonitrile-butadiene-styrene (ABS) feed-stocks for 3D printing process.
Design/methodology/approach
In this study, composite filaments were produced by using a co-rotational twin screw extruder and used as building material to print samples in a commercial fused deposition modeling (FDM) 3D printer. The reinforcement particles, ZrB2 and Al, have different properties, including density, surface area, purity and particle morphology, and were expected to improve mechanical properties of 3D printed samples. Differential calorimetry scanning and melt flow index studies were applied on the materials to observe the change in glass transition temperatures and melt flow behaviors, respectively. Also, to evaluate the mechanical properties, tensile and three-point bending test were carried out. Fractured surfaces were characterized via energy-dispersive X-ray spectroscopy for validation of the reinforcements in the ABS matrix. Moreover, scanning electron microscope micrograph examination was conducted on the fractured surfaces to characterize fracture modes.
Findings
For 3D printed samples, a strain increase of at least 82.5 per cent was achieved by using micro particle reinforcement with a weight ratio of 1.5 per cent.
Research limitations/implications
Higher filler ratios of the reinforcement particles cause loss on the printability of the feed-stocks.
Practical implications
Reinforced ABS stands out as a possible solution to overcome robustness problems in FDM printing.
Originality/value
Even though the effects of printing parameters on the mechanical properties of 3D printed parts have been vastly studied in the literature, studies conducted on improvement of the building materials are limited. This paper proposes to create novel feed-stock materials for achieving printed parts with superior properties using polymer composites.
Details
Keywords
Tan Chen, Wei-jun Zhang, Jian-jun Yuan, Liang Du and Ze-yu Zhou
This paper aims to present a different cooling method (water cooling) to protect all the mechanical/electrical components for Tokamak in-vessel inspection manipulator. The method…
Abstract
Purpose
This paper aims to present a different cooling method (water cooling) to protect all the mechanical/electrical components for Tokamak in-vessel inspection manipulator. The method is demonstrated effective through high temperature experiment, which provides an economical and robust approach for manipulators to work normally under high temperature.
Design/methodology/approach
The design of cooling system uses spiral copper tube structure, which is versatile for all types of key components of manipulator, including motors, encoders, drives and vision systems. Besides, temperature sensors are set at different positions of the manipulator to display temperature data to construct a close-loop feedback control system with cooling components.
Findings
The cooling system for the whole inspection manipulator working under high temperature is effective. Using insulation material such as rubber foam as component coating can significantly reduce the environmental heat transferred to cooling system.
Originality/value
Compared with nitrogen gas cooling applied in robotic protection design, although it is of less interest in prior research, water cooling method proves to be effective and economical through our high temperature experiment. This paper also presents an energetic analysis method to probe into the global process of water cooling and to evaluate the cooling system.
Details
Keywords
Mehmet Akif Ceviz, Faraz Afshari, Burak Muratçobanoğlu, Murat Ceylan and Eyüphan Manay
The purpose of this paper is to experimentally and numerically investigate the cooling performance of the air-to-water thermoelectric cooling system under different working…
Abstract
Purpose
The purpose of this paper is to experimentally and numerically investigate the cooling performance of the air-to-water thermoelectric cooling system under different working conditions.
Design/methodology/approach
An air-to-water thermoelectric cooling system was designed and manufactured according to the principle of discrete binary thermoelectric Peltier modules, and the thermal performance, heat transfer rate and average COP values were examined at different cooling water temperatures and voltages applied. Additionally, numerical simulations were performed by computational fluid dynamics approach to investigate the temperature distribution and airflow structure inside the cooling chamber.
Findings
Analyses were performed using experimental tests and numerical methods. It was concluded that, by decreasing the cooling water temperature from 20 to 5 °C, the average COP increases about 36%. The voltage analysis showed that the efficiency of the system does not always increase as the voltage rises; more importantly, the optimum voltage is different and depends on whether it is desired to increase COP or increase the cooling rate.
Originality/value
In the studies published in the field of thermoelectric cooling systems, little attention has been paid to the voltage applied and its relationship to other operating conditions. In most cases, the tests are performed at a constant voltage. In this study, several options, including applied voltage and cooling water temperature, were considered simultaneously and their effects on performance have been tested. It was found that under such studies, optimization work should be done to evaluate maximum performance in different working conditions.
Details
Keywords
Mohamed S. Gadala and Fuchang Xu
To develop an effective and reliable procedure for the calculation of heat fluxes from the measured temperatures in experimental tests of impingement water cooling.
Abstract
Purpose
To develop an effective and reliable procedure for the calculation of heat fluxes from the measured temperatures in experimental tests of impingement water cooling.
Design/methodology/approach
An inverse heat transfer analysis procedure is developed and implemented into a 2D finite element program. In this method, the least‐squares technique, sequential function specification and regularization are used. Simplifications in the sensitivity matrix calculation and iterative procedures are introduced. The triangular and impulse‐like profiles of heat fluxes simulating practical conditions of impingement water cooling are used to investigate the accuracy and stability of the proposed inverse procedure. The developed program is then used to determine the heat flux during impingement water cooling.
Findings
A hybrid procedure is developed in which inverse calculations are conducted with a computation window. This procedure may be used as a whole time domain method or become a periodically sequential or real sequential method by adjusting the sequential steps.
Originality/value
Parametric study and application show that the developed method is effective and reliable and that inverse analysis may obtain the heat flux with an acceptable level of accuracy.
Details