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This study aims to numerically investigate the thermal-hydrodynamic performance of silicon oxide/water nanofluid laminar flow in the heat sink miniature channel with different fin cross-sections. The effect of the fin cross-section including semi-circular, rectangular and quadrant in two directions of flat and curved, and channel substrate materials of steel, aluminum, copper and titanium were examined. Finally, the analysis of thermal and frictional entropy generation in different channels is performed.

According to the numerical results, the highest heat transfer coefficients belong to the rectangular, quadrant 2, quadrant 1 and semi-circular fins compared to the channel without fin is 38.65%, 29.94%, 27.45% and 17.1%, respectively. Also, the highest performance evaluation criteria belong to the rectangular and quadrant 2 fins, which have 1.35 and 1.29, respectively. Based on the thermal conductivity of the substrate material, the best material is copper. According to the results of entropy analysis, the reduction of thermal irreversibility of the channel with rectangular, quadrant 1, quadrant 2 and semi-circular compared to non-finned channel is equal to 72%, 57%, 63% and 48%, respectively.

The rectangular and quadrant 2 fins are the best fins and the copper substrate material is the best material to reduce the entropy generation.

The silicon oxide/water nanofluid flow in the heat sink miniature channel with various fin shapes and the curvature angle against the fluid flow was simulated to increase the heat transfer performance. The whole test section is simulated in three-dimensional. Different channel materials have been investigated to find the best channel substrate material.

This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence.

In this paper, an experimental study on NACA 0020 airfoil with thin extended trailing edge modification of amplitude of h = 0.1c, 0.2c and 0.3c at the Reynolds number of 2.14 × 10⁵ are tested. The research was carried out for an angle of attack ranging from 0° = α = 35° for the turbulence intensity of 0.3%, 3%, 5%, 7% and 12%. From the experimental readings, the surface pressures are scanned using a Scanivalve (MPS2464) pressure scanner for a sampling frequency of 700 Hz. The scanned pressures are converted to aerodynamic force coefficient and the results are combined and discussed.

The airfoil with the extended trailing edge will convert the adverse pressure gradient to a plateau pressure zone, indicating the delayed flow separation. The CL value at higher turbulence intensity (TI = 12%) for the extended trailing edge over perform the base airfoil at the post-stall region. The maintenance of flow stability is observed from the spectral graph.

A thin elongated trailing edge attached to the conventional airfoil serves as a flow control device by delaying the stall and improving the lift characteristics. Additionally, extending the airfoil's trailing edge helps to manage the performance of the airfoil even at a high level of turbulence.

Distinct from existing studies, the presented results reveals how the extended trailing edge attached to the airfoil performs in the turbulence zone ranging from 0.3% to 12% of TI. The displayed pressure distribution explains the need for increasing trailing edge amplitude (h) and its impact on flow behaviour. The observation is that extended trailing edge airfoil bears to maintain the performance even at higher turbulence region.

Extreme weather events introduced by climate change have been frequent across the world for the past decade. For example, Takeda City, a mountainous area in the south-western Japan, experienced a severe river flood event caused by the factors of high flow, presence of bridges and driftwood accumulation in July 2012. This study aims to focus on this event (hereafter, Takeda flood) because the unique factors of driftwood and bridges were involved. In the Takeda flood, high flow, driftwood and bridge were the potential key factors that caused the flood. The authors studied to reveal the physical processes of the Takeda flood.

The authors conducted a fundamental laboratory experiment with a miniature bridge, open channel flow and idealized driftwood accumulation. They also performed a numerical simulation by using a smoothed particle hydrodynamics (SPH) method, which can treat fluid as particle elements. This model was chosen because the SPH method is capable of treating a complex flow such as a spray of water around a bridge.

The numerical simulation successfully reproduced the bridge- and driftwood-induced floods of the laboratory experiment. Then, the contribution of the studied key factors to the flood mechanism based on the fluid forces generated by high flow, bridge and driftwood (i.e. pressure distributions) was quantitatively assessed. The results showed that the driftwood accumulation and high flow conditions are potentially important factors that can cause a severe flood like the Takeda flood.

Simulated results with high flow conditions may be helpful to consider the countermeasure for future floods under climate change even though the test was simple and fundamental.

The importance of Carbon dioxide (CO₂) gas detection as a greenhouse and exhale breathe gas is an undeniable issue. This study aims to propose a new miniaturized, low cost and portable no dispersive infrared (NDIR) system for detecting CO₂ gas.

Poly(methyl methacrylate) (PMMA)-based channels with Au coating because of its high reflection properties in IR region were used in this work. The optical windows were fabricated using PDMS polymer which is cost effective and novel in comparison to other conventional methods. The effects of channel dimensions, lengths and entrance angle of light on optical path length and losses were analyzed with four types of channel using both simulation and experimental tests.

The simulation results indicate that the 0 degree light entrance angle is the most efficient angle among different investigated conditions. The experimental data are in agreement with the simulation results regarding the loss and optical path length in different types of channel. The experimental tests were performed for the 0.5% up to 20% of CO₂ concentration under constant temperature and humidity condition. The results show that the device with 5  and 2 cm channels length were saturated in 4% and 8% concentration of CO₂ gas, respectively. Response and recovery times were depending on gas concentration and channels specifications that in average found to be 10 S and 14 S, respectively, for the largest size channel. Moreover, the environment humidity effect on detection system performance was investigated which had no considerable influence. Also, the saturation fraction absorbance value for devices with various dimensions were 0.62 and 0.8, respectively.

According to the performed curve fitting for practical situation and selected CO₂ concentration range for experimental tests, the device is useful for medical and environmental applications.

PMMA with Au deposition layer was used as a basic material for this NDIR system. Besides, a novel PDMS optical window helps to have a low cost device. The effects of channel dimensions, lengths and entrance angle of light on optical path length and losses were analyzed using both simulation and experimental tests. Using narrowband optical filter (100 nm bandwidth) helps to have a system with good CO₂ selectivity. In addition, experimental tests with different channel dimensions and lengths covered a considerable range of CO₂ concentration useful for medical and environmental applications. Finally, curve fitting was adopted for a modified Beer–Lambert law as a practical situation.

The general-purpose engine lathe is the most basic turning machine tool. As with all lathes, the two basic requirements for turning are a means of holding the workpiece while it rotates as well as a means of holding cutting tools and moving them relatively to the workpiece. In this paper, we present the results of finite element analysis (FEA) performed to investigate nature of stress and their distribution at optimum point along the two turning tables of a micro-controller based versatile machine tool desktop learning module. Commercial Autodesk Inventor was used to create both three-dimensional (3D) and 2D models as well as performing simulation. Dynamics simulation generated the motion load expected to act on the tables when used for real-life operation which were in turn used to perform the FEA. The motion of the DC stepper motor driving the tables and other parts of the module is designed to be controlled by programmable chips. Before creating FEA simulation for the tables, numerical divergence were prevented by varying the mesh settings to obtain the settings at which the results of the analyses converges which was obtained at 0.03 average element size and 0.04 minimum element size. Finite element analysis carried out on the tables shows that aluminium alloy 4032-T6 chosen will serve in the fabrication of physical prototype. FEA revealed the nature and level of stresses that will be experienced on the tables, it also revealed region where these stresses will concentrate on them. The analysis also estimated the expected weight of the turning tables 1&2 to be 1.23536 and 0.257182 kg respectively and show that the minimum factor of safety was constantly 15 ul within the tables which means that they will not fail during operation.

As one of the tomographic imaging techniques, electrical capacitance tomography (ECT) is widely used in many industrial applications. While most ECT sensors have electrodes placed around a cylindrical chamber, the planar ECT sensor has been investigated for depth and defect detection. However, the planar ECT sensor has limited height and depth sensing capability due to its single-sided assessment with the use of only a single-plane design. The purpose of this paper is to investigate a dual-plane miniature planar 3D ECT sensor design using the 3 × 3 matrix electrode array.

The sensitivity map of dual-plane miniature planar 3D ECT sensor was analysed using 3D visualisation, the singular value decomposition and the axial resolution analysis. Then, the sensor was fabricated for performance analysis based on 3D imaging experiments.

The sensitivity map analysis showed that the dual-plane miniature planar 3D ECT sensor has enhanced the height sensing capability, and it is less ill-posed in 3D image reconstruction. The dual-plane miniature planar 3D ECT sensor showed a 28% improvement in reconstructed 3D image quality as compared to the single-plane sensor set-up.

The 3 × 3 matrix electrode array has been proposed to use only the necessary electrode pair combinations for image reconstruction. Besides, the increase in number of electrodes from the dual-plane sensor setup improved the height reconstruction of the test sample.

An advanced heat transfer model for both unlooped and looped Pulsating Heat Pipes (PHPs) with multiple liquid slugs and vapor plugs has been developed. The thin film evaporation and condensation models have been incorporated with the model to predict the behavior of vapor plugs and liquid slugs in the PHP. The results show that heat transfer in both looped and unlooped PHPs is due mainly to the exchange of sensible heat. Higher surface tension results in a slight increase in the total heat transfer. The diameter, heating wall temperature, and charging ratio have significant effects on the performance of the PHP. Total heat transfer significantly decreased with a decrease in the heating wall temperature. Increasing the diameter of the tube resulted in higher total heat transfer. The results also showed that the PHP could not operate for higher charge ratios.

The purpose of this study is the design, fabrication and evaluation of a miniature ozone generator using the principle of electric discharge are presented.

The device was fabricated using a low-temperature co-fired ceramics (LTCC) technology, by which a multilayered ceramic structure with integrated electrodes, buried channels and cavities in micro and millimeter scales was realized.

The developed ozone generator with the dimensions of 63.6 × 41.8 × 1.3 mm produces approximately 1 vol. % of ozone in oxygen flow of 15 ml/min, at an applied voltage of 7 kV.

A miniature ozone generator, manufactured in LTCC technology, produces high amount of ozone and more than it is described in the available references or in datasheets of commercial devices of similar size.

Details of Electrical and Electronic Apparatus with Applications in the Maintenance and Operation of Aircraft, Missiles and Space Vehicles. Details of a completely new, solid state, miniature vidicon television camera channel have been announced by the Closed Circuit Television Division of the Marconi Company. This 321 Scries camera channel has been specifically designed for the highly specialized requirements of aircraft, marine, military and heavy industrial applications where there is a growing need for a fully automatic equipment able to give extremely reliable operation under the most arduous environmental conditions and to withstand considerable vibration and mechanical shock in normal operation.

This paper aims to present a history of the marketing of hope chests in the USA, focusing in particular on one very successful sales promotion, the Lane Company’s Girl Graduate Plan. The Girl Graduate Plan is placed within its historical context to better understand the socioeconomic forces that contributed to its success for a considerable period but ultimately led to decreased demand for the product.

The history of the marketing of hope or marriage chests draws upon primary sources located in the Lane Company Collection at the Virginia Museum of History and Culture. Secondary sources and images of advertising culled from Google image searches provided additional insight into the operation of the company’s Girl Graduate Plan.

While the Lane Company benefitted in the form of increased sales, profit and brand awareness and loyalty from prevailing socio-economic trends, which supported the success of its Girl Graduate Plan, including targeting the youth market, this promotion ultimately fell victim to the company’s failure to stay abreast of social changes related to the role of women in society.

Like all historical research, this research is dependent upon the historical sources that are accessible. The authors combined documents available from the Virginia Historical Society archives with online searches, but other data sources may well exist.

This history investigates how one manufacturer, a leader in the North American industry, collaborated with furniture dealers to promote their products to young women who were about to become the primary decision makers for the purchase of home furnishings. As such, it provides an historical example of the power of successful collaboration with channel partners. It also provides an example of innovation within an already crowded market.

The hope chest as an object of material culture can be found in many cultures worldwide. It has variously represented a woman’s coming of age, the love relationship between a couple and a family’s social status. It has also served as a woman’s store of wealth. This history details how changing social values influenced the popularity of the hope chest tradition in the USA.

The history of the marketing of hope chests is an area that has not been seriously considered in consumption histories or in histories of marketing practices to date, in spite of the continuing sentimental appeal for many consumers.