136 research outputs found
Investigate the potential of using trilateral flash cycle for combined desalination and power generation integrated with salinity gradient solar ponds
This paper examines the concept of using the trilateral flash cycle for combined desalination and power generation from salinity gradient solar ponds in the salt affected areas of Australia. Firstly causes of the high salinity in the ground waters of northern Victoria, Australia are discussed. Existing salinity mitigation schemes are introduced and the integration of solar ponds with those schemes is discussed. Further the basic working principle of the combined desalination and power generation system is discussed followed by discussion of the governing equation and thermodynamics used in the desalination and power generation process. Experimental setup and the test results are briefly explained to give an idea of the performance of the present system. Later it is shown how a combined desalination and power generation system can be coupled with a solar pond for fresh water production and power generation. Following the introduction of this concept the preliminary design is presented for a demonstration of a combined desalination and power plant coupled with a solar pond of 10000 m2 surface area and a depth of 3 m located in the northern region of Victoria. The performance, including fresh water output, power output and efficiency of the proposed plant operating in northern Victoria is analysed and the results are discussed
Incidence and distribution of seed-borne fungi associated with wheat in Markazi Province, Iran
53 seed samples collected from harvested seed loads of irrigated wheat fields in Markazi province in the central of Iran was used for this study. Isolation and identification of seed-borne fungi were conducted according to standard tests described by the International Seed Testing Association (ISTA). A total of 15 fungal species including Tilletia laevis, Tilletia tritici, Ustilago tritici, Fusarium graminearum, Fusarium culmorum, Microdochium nivale, Bipolaris sorokiniana, Alternaria alternata, Curvularia sp., Aspergillus niger, Aspergillus candidus, Aspergillus flavus, Penicillium sp., Mucor sp. and Rhizopus sp. were identified in three wheat cultivars of Backcross Roshan, Alvand and C-78-14. The average of infection level in tested samples to both T. laevis and T. tritici was estimated as much as 7.1% in the province and the minimum and maximum infection levels were found in Lilian (Khomein) and Jirya regions (Arak), respectively. The average of infection rate by U. tritici in seed samples was 1.3% while it was as much as 17.4% for both F. culmorum and B. sorokiniana in the province. The frequency of A. niger and Penicillium sp. was predominant with an infection range of 37.8 and 29.1%, respectively. For the first time, the incidence and infection level of seed-borne fungi in wheat seeds have been determined in the central part of Iran.Key words: Infection rate, seed-borne fungi, seed quality, wheat
Dual thermal system for power and fresh water production
Within most areas of Australia the supply of natural fresh water is being stretched to breaking point in order to meet the increasing demand for agricultural, industrial and domestic uses. At the same time, electricity is presently being generated from predominantly non-renewable and polluting fossil fuels. As it has been searched, there is no technology which can provide the combined solution for fresh water production and power generation together. Therefore, the primary aim of this project has been to develop a dual geothermal system that uses hot saline water from geothermal reservoirs in Australia and can simultaneously produce fresh water and electrical power. A low cost and high performance simple reaction turbine has been developed for use in a Combined Desalination and Power generation (CDP) unit to convert the energy of geothermal hot water directly to electricity while also producing fresh water. The thesis presents a systematic procedure for manufacturing the turbine rotors for the new turbine. Experimental data on the performance of the CDP unit are reported and analysed. An optimised design for a low cost and high performance simple reaction turbine for a larger-scale demonstration CDP unit has been developed for electricity and fresh water production from low temperature geothermal waters
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Investigation of a dynamics-oriented engineering approach to ultraprecision machining of freeform surfaces and its implementation perspectives
© 2021 Author(s). In current precision and ultraprecision machining practice, the positioning and control of actuation systems, such as slideways and spin- dles, are heavily dependent on the use of linear or rotary encoders. However, positioning control is passive because of the lack of direct monitoring and control of the tool and workpiece positions in the dynamic machining process and also because it is assumed that the machining system is rigid and the cutting dynamics are stable. In ultraprecision machining of freeform surfaces using slow tool servo mode in particular, however, account must be taken of the machining dynamics and dynamic synchronization of the cutting tool and workpiece positioning. The important question also arises as to how ultraprecision machining systems can be designed and developed to work better in this application scenario. In this paper, an innovative dynamics-oriented engineering approach is presented for ultra- precision machining of freeform surfaces using slow tool servo mode. The approach is focused on seamless integration of multibody dynamics, cutting forces, and machining dynamics, while targeting the positioning and control of the tool–workpiece loop in the machin- ing system. The positioning and motion control between the cutting tool and workpiece surface are further studied in the presence of interfacial interactions at the tool tip and workpiece surface. The interfacial cutting physics and dynamics are likely to be at the core of in-process monitoring applicable to ultraprecision machining systems. The approach is illustrated using a virtual machining system developed and supported with simulations and experimental trials. Furthermore, the paper provides further explorations and discussion on implementation perspectives of the approach, in combination with case studies, as well as discussing its fundamental and industrial implications.Ph.D. Scholarship funding support from Brunel University London and the UK EPSRC
CFD-based design and analysis of air-bearing-supported paint spray spindle
Copyright © 2018 The Author(s). In this paper, an analytical scientific approach is presented for the design and analysis of an air-turbine-driven paint spray spindle, and it is used to improve further the design concept of the existing spindle applied in auto-motive coating and paint spraying applications. The current spindle on the market can operate at a maximum speed of 100,000 rpm and features a maximum bell size of 70 mm diameter. Given the increasing demands forhigh automotive coating/painting quality and productivity in assembly, the design and development of a paint spray spindle with a speed of 145,000 rpm or higher is needed. Computational fluid dynamics (CFD)-based simulation is applied in the approach. Accordingly, CFD simulation-based design and analysis are undertaken, covering the characteristic factors of velocity, pressure of the air supply, rotational speed of the air-turbine, and torque and force reaction on the turbine blades. Furthermore, the turbine blade geometric shape is investigated throughthe simulations. Three geometrical concepts have been investigated against the original model. The results onConcept_03 verified the higher angular velocity speeds against the theoretical model. The pressure and velocity effects in the blades have been investigated. The results show that the pressure and velocity of the air supply driving the turbine are critical factors influencing the stability of turbine spinning. The results also demonstrate that the force acting on the blades is at the highest level when the adjacent face changes from a straight surface into a curve. Finally, changing the geometrical shape in the turbine likely increases the tangential air pressure at the blades surface and relatively increases the magnitude of the later altorque and force in the spindle. Notwithstanding this condition, the analytical values surpass the theoretical target values
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Multi-Body Dynamic Analysis of Hydrostatic Bearing with the MMC Material in Micro-Nano Machining
Data Availability Statement: The Data is unavailable due to privacy and ethical restrictions.Copyright © 2023 by the authors. This study focuses on the analysis of a linear hydrostatic bearing using harmonic frequency response and harmonic response simulations. The aim is to evaluate the feasibility of replacing the existing alloy steel material with a metal matrix composite (MMC) in terms of its performance and dynamic characteristics for both the base and carriage parts. The simulation results indicate that the MMC material exhibits higher resonant frequencies and improved damping capabilities compared to the structural steel material. The higher resonant frequencies observed in the MMC material are attributed to its stiffness and structural properties. These properties contribute to increased natural frequencies and improved vibration damping characteristics. This suggests that incorporating the MMC material in the bearing design could enhance motion control, improving the ability to precisely control and manipulate the movement of components or systems. In the context of ultraprecision machining applications, incorporating the MMC material in the hydrostatic bearing design can also lead to a more accurate and controlled motion, resulting in improved precision and finer machining outcomes. The displacement analysis confirms that both materials meet the specifications provided by the manufacturer, supporting the viability of using MMC as an alternative. However, further experimental validation and considerations of material feasibility, manufacturing factors, and cost-effectiveness are necessary before implementing the MMC material in practical applications. Overall, this research highlights the potential benefits of MMC in the design of linear hydrostatic bearings, paving the way for enhanced performance in ultraprecision machining processes.This research received no external funding
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Determinant of Dynamics and Interfacial Forces in Ultraprecision Machining of Optical Freeform Surface through Simulation-Based Analysis
Data Availability Statement:
The data in this study is unavailable due to data privacy and restrictions.This study delves into the intricacies of ultraprecision machining, particularly in the context of machining optical freeform surfaces using Diamond Turning Machines (DTMs). It underscores the dynamic relationship between toolpath generation, hydrostatic bearing in DTMs, and the machining process. Central to this research is the innovative introduction of Metal Matrix Composites (MMCs) to replace the traditional materials used in designing linear bearings. This strategic substitution aims to dynamically enhance both the accuracy and the quality of the machined optical freeform surfaces. The study employs simulation-based analysis using ADAMS to investigate the interfacial cutting forces at the tooltip and workpiece surface and their impacts on the machining process. Through simulations of STS mode ultraprecision machining, the interfacial cutting forces and their relationship with changes in surface curvatures are examined. The results demonstrate that the use of MMC material leads to a significant reduction in toolpath pressure, highlighting the potential benefits of employing lightweight materials in improving the dynamic performance of the system. Additionally, the analysis of slideway joints reveals the direct influence of interfacial cutting forces on the linear slideways, emphasising the importance of understanding and controlling these forces for achieving higher-precision positioning and motion control. The comparative analysis between steel and MMC materials provides valuable insights into the effects of material properties on the system’s dynamic performance. These findings contribute to the existing body of knowledge and suggest a potential shift towards more advanced precision forms, possibly extending to pico-engineering in future systems. Ultimately, this research establishes a new standard in the field, emphasising the importance of system dynamics and interfacial forces in the evolution of precision manufacturing technologies.This research received no external funding
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Effect of transforming growth factor-β on up/down regulation of integrin-β1 in primary chondrocyte culture
yesRegeneration of a damaged or non-functioning tissue requires adhesion of cells to their extracellular matrix (ECM). Thus the investigation of the level of synthesised cell adhesion molecules (CAMs) in cell culture systems play major roles in cell and tissue engineering. Adhesion of chondrocyte to a collagen type-II rich matrix, is dependent on cell adhesion molecules (CAMs) and integrins and cells adhere to ECM through integrins
Synthesis of magnetic multiwalled carbon nano tubes and investigation of isotherm and kinetic models for cleanup of carbaryl pesticide
Water is the main factor of movement and transport of pesticides and contamination of water by these pollutants is one of the most important challenges due to their widespread use and increased concentrations. Moreover, these compounds are on the U.S.EPA Priority Pollutant list because of the potential of accumulation and the property of damaging effects. In this study, multiwalled carbon nanotube-based magnetic nanoparticles were synthesized and used as an affective adsorbent for carbaryl pesticide. The properties of the synthesized Fe3O4@MWCNTs were characterized by TEM images and XRD analysis. The obtained data were studied by isotherm and kinetic models. Carbaryl adsorbed onto the synthesized adsorbent was compatible with the Langmuir isotherm (R2 = 0.993). The maximum adsorption capacity (qmax) of the pesticide onto the Fe3O4-MWCNTs was obtained at 68.2 mg/g. The kinetic studies of the reactions showed that the adsorption process followed the pseudo-second order model with R2 � 0.99 for all initial carbaryl concentrations. The adsorbent was extracted by magnet reused several times (six rounds) with a reasonable efficiency. The Fe3O4MWCNTs have great potential for adsorption of carbaryl from water and wastewater due to high efficiency, easy separation and reusability. © 2020 Global NEST
Effect of TGF-β1 on water retention properties of healthy and osteoarthritic chondrocytes
YesArticular cartilage, a connective tissue, contains chondrocytes and glycosaminoglycans (GAGs) which aid in
water retention, providing the tissue with its magnificent ability to prevent friction, withstand loads and absorb
compressive shocks however, cartilage, does not have the ability to regenerate and repair. Osteoarthritis (OA) is
a progressive degenerative disease, which includes reduction of cartilage thickness between two bones in a joint,
causing painful bone-to-bone contact. OA affects over 8 million people in the UK alone. , and as the primary causes
are unknown, available treatments including surgical and non-surgical techniques which only reduce the symptoms
created by the disorder instead of providing a cure. This project focused on utilizing TGF-β1, a cytokine found in
elevated amounts in healthy cartilage when compared to degraded cartilage, in order to observe the effects of the
growth factor on both healthy and osteoarthritic chondrocytes. The healthy and the osteoarthritic chondrocytes were
cultured in two different media (DMEM with and without TGF- β1) before utilizing the SpectraMax M2/M2e
plate reader to observe and analyze the effect of TGF-β1 on water retention properties of cells. This has been
achieved by quantifying the GAG content using DMMB dye. Results showed that although TGF-β1 did displayed an
increase in glycosaminoglycan synthesis, the statistical increase was not vast enough for the alternative hypothesis to
be accepted; further experimentation with TGF-β1, alongside other cytokines within the growth factor family is
needed to perceive the true influence of the growth factor on un cured degenerative diseases. It was concluded that
both the healthy and osteoarthritic cells treated with TGF-β1 absorbed considerably more DMMB in comparison to
the cells, suggesting that TGF-β1 indeed works to aid in water retention. TGF-β1 is a key factor to be exploited when
constructing treatments for osteoarthriti
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