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Solar-driven water desalination technologies are rapidly developing with various links to other renewable sources. However, the efficiency of such systems severely depends on the design parameters. This paper presents results from an investigation on the effect of the glass cover inclination angle on the performance of two stepped solar still geometries (flat and convex) and the amount of produced distilled water.

Studied inclination angles of 25°, 27.5°, 30°, 32.5° and 35° were chosen, while other design parameters were fixed.

The investigation showed that the unit with the convex absorber plate had higher average water daily production rate, compared to the output of the flat absorber plate unit. The results also depicted that the inclination angle of the still has a noticeable effect on the performance of solar stills. The value of the critical angle is 32.5°, and the higher inclination angle results in less heat transfer coefficient. This value can be used for design purposes and erases the typical assumption to use lower angles to optimize the productivity of the still.

Finally, obtained data were used to correlate the Nusselt number for the flat and convex surfaces with different inclination angles of the glass cover.

The outcome of this investigation may find applications to develop highly efficient solar stills to secure more drinkable water in warm, dry lands.

The purpose of the paper is to give a brief description of the new topic introduced for the first time at the EASN Conferences.

The topic concerns the heliosphere, the nearest surrounding of the Sun and thus the nearest vicinity of the Earth. The heliosphere is created due to the interaction between the solar wind and the local interstellar medium.

This paper does not include any new information about the heliosphere and only introduces a new topic to this journal. It is briefly shown how heliospheric structures are formed, what factors affect a shape of the heliosphere, what measurements are made by Ulysses, Voyager and IBEX space missions (important for the heliosphere modeling) and how obtained data are used to validate theoretical results.

To categorize the paper under one of these classifications, research paper, viewpoint, technical paper, conceptual paper, case study, literature review or general review, the authors chose a paper type, general review, as the closest category to this paper. However, it is not a purpose of this paper to provide an extensive review of the community efforts to investigate the physical processes in the vicinity of the heliosphere interface. This is mostly a status report.

As the new topic in this journal, the article introduces in detail only a small number of aspects connected with heliosphere models. Interplanetary and interstellar magnetic field structures are primarily described. Other factors are only mentioned.

The purpose of this paper is to understand the effect of basin water depth towards the cumulative distillate yield of the traditional and developed single basin double slope solar still (DSSS).

Modified single basin DSSS integrated with solar operated vacuum fan and external water cooled condenser was fabricated using aluminium material. During sunny season, experimental investigations have been performed in both conventional and modified DSSS at a basin water depth of 3, 6, 9 and 12 cm. Production rate and cumulative distillate yield obtained in traditional and developed DSSS at different water depths were compared and best water depth to attain the maximum productivity and cumulative distillate yield was found out.

Results indicated that both traditional and modified double SS produced maximum yield at the minimum water depth of 3 cm. Cumulative distillate yield of the developed SS was 16.39%, 18.86%, 15.22% and 17.07% higher than traditional at water depths of 3, 6, 9 and 12 cm, respectively. Cumulative distillate yield of the developed SS at 3 cm water depth was 73.17% higher than that of the traditional SS at 12 cm depth.

Performance evaluation of DSSS at various water depths by integrating the combined solar operated Vacuum fan and external Condenser.

This paper aims to present experimental work examining the effect of opening size on the collection efficiency of cavity-type receiver geometries, e.g. modified cavity and spherical cavity with single- as well as dual-stage water heating. The correlations, obtained using the experimentally obtained data, are helpful in designing of cavity receivers (modified and spherical geometry type) to be used in solar-power harnessing assignments/projects, for yielding better system performance.

The parameters of study encompass receiver opening or aperture ratios (d/D, ratio of diameter of opening to the maximum diameter of spherical cavity) of 0.4, 0.47, 0.533 and 0.6; flow Reynolds numbers of 938, 1,175, 1,525 and 1,880 with water as a coolant; and receiver inclination angles of 90, 60, 45 and 30° (with 90° as receiver-opening facing downward and 30° as receiver-aperture facing closer to sideway). A modified cavity receiver was examined for opening ratios of 0.46, 0.6, 0.7 and 0.93. The glass covers, with thickness 2, 4 and 6 mm, were positioned at the opening of cavity to mitigate the energy losses.

The experiments have been conducted at a lesser incoming radiative heat flux, for receiver cavity wall surface temperatures ranging from 90°C to 180°C. The collection efficiency values of both the receivers, modified cavity and spherical cavity types, are seen increasing with coolant flow rate and receiver tilt (inclination) angles, i.e. 30° → 90°. The collection efficiency exhibits maxima at an opening ratio of 0.533 in case of both single- and double-stage spherical cavity receiver. This value was observed as 0.6 for modified cavity receiver. The mathematical correlations developed for obtaining the collection efficiency values of modified cavity-type receiver, spherical cavity receiver with single stage and spherical cavity receiver with dual-stage water heating are given as ɳ=0.4667 Re0.0798dD0.1651 δ0.0281θ̇−0.011, ɳ=0.2317 Re0.124 dD1.265δ0.0192θ̇0.2914 and ɳ=0.1137 Re0.1715dD0.8702θ̇0.2757, respectively.

The findings of the paper may be helpful in erecting concentrating solar collector systems for household water heating, concentrating solar-based power generation as well as for various agricultural applications.

The experimental investigations are fewer in the literature examining the combined geometrical influence on the efficiency of cavity receivers with single- and double-stage water heating provisions.

The effect of inclination on laminar natural convection in a square cavity is studied numerically for inclination angles ranging from 40° to 160°, Rayleigh numbers between 10³ and 10⁶ and Prandtl numbers from 0.02 to 4,000. Contours of stream functions and temperature are presented in order to provide a new insight and a better understanding of the flow and heat transfer characteristics in a square cavity. Finds computed local and mean Nusselt numbers at the hot wall in satisfactory agreement with experimental and other numerical results. Finds the mean heat flux at the hot wall as well as the distribution of the local heat flux along the heated wall are found to depend on the inclination angle, the Rayleigh number and the Prandtl number. Such a dependence is significant for angles greater than 90°, while for smaller angles the effect of the inclination angle on the Nusselt‐Rayleigh correlation is weaker.

The apparel industry is a labor-intensive industry, which depends mainly on the performance of the worker. The purpose of this study is to present an ergonomic redesign of the sewing machine workstation, with different sewing table heights and inclination angles, based on the operator’s anthropometric data.

A flexible ergonomic sewing table has been designed, four main workstation-setting factors were studied; sewing desk inclination angles – X_1, height – X_2, sewing machine type – X_3 and operator’s body mass index (BMI) – X_4, with three levels for each factor, except sewing machine type, which only has two levels. The study was undertaken to specify the limitations and advantages of each combination tested. Different measurement techniques were used; subjective information, production rates – P, working postures (head, neck and trunk inclination angles in the kinematic stage) were measured.

Sewing operators’ sitting posture angles in the kinematic stage were affected more or less by their anthropometric measurements and the type of sewing machine. These two factors should be taken into consideration when ergonomically redesigning the sewing machine workstation.

A new ergonomically redesigned sewing machine table can be incorporated into garment factories, taking into consideration the BMI of the operators to improve their productivity and reduce musculoskeletal disorder complaints due to incorrect operators’ posture.

An important correlation was found between the sewing operator’s anthropometric body measurement – BMI and the type of sewing machine (with significant R^2 = 0.8385 and 0.9764 with both the head and neck inclination angles O_H, O_N, respectively).

The swivel construction method is a specially designed process used to build bridges that cross rivers, valleys, railroads and other obstacles. To carry out this construction method safely, real-time monitoring of the bridge rotation process is required to ensure a smooth swivel operation without collisions. However, the traditional means of monitoring using Electronic Total Station tools cannot realize real-time monitoring, and monitoring using motion sensors or GPS is cumbersome to use.

This study proposes a monitoring method based on a series of computer vision (CV) technologies, which can monitor the rotation angle, velocity and inclination angle of the swivel construction in real-time. First, three proposed CV algorithms was developed in a laboratory environment. The experimental tests were carried out on a bridge scale model to select the outperformed algorithms for rotation, velocity and inclination monitor, respectively, as the final monitoring method in proposed method. Then, the selected method was implemented to monitor an actual bridge during its swivel construction to verify the applicability.

In the laboratory study, the monitoring data measured with the selected monitoring algorithms was compared with those measured by an Electronic Total Station and the errors in terms of rotation angle, velocity and inclination angle, were 0.040%, 0.040%, and −0.454%, respectively, thus validating the accuracy of the proposed method. In the pilot actual application, the method was shown to be feasible in a real construction application.

In a well-controlled laboratory the optimal algorithms for bridge swivel construction are identified and in an actual project the proposed method is verified. The proposed CV method is complementary to the use of Electronic Total Station tools, motion sensors, and GPS for safety monitoring of swivel construction of bridges. It also contributes to being a possible approach without data-driven model training. Its principal advantages are that it both provides real-time monitoring and is easy to deploy in real construction applications.

The research focused on analysing a unique type of heat exchanger that uses swirling air flow over heated tubes. This heat exchanger includes a round baffle plate with holes and opposite-oriented trapezoidal air deflectors attached at different angles. The deflectors are spaced at various distances, and the tubes are arranged in a circular pattern while maintaining a constant heat flux.

This setup is housed inside a circular duct with airflow in the longitudinal direction. The study examined the impact of different inclination angles and pitch ratios on the performance of the heat exchanger within a specific range of Reynolds numbers.

The findings revealed that the angle of inclination significantly affected the flow velocity, with higher angles resulting in increased velocity. The heat transfer performance was best at lower inclination angles and pitch ratios. Flow resistance decreased with increasing angle of inclination and pitch ratio.

The average thermal enhancement factor decreased with higher inclination angles, with the maximum value observed as 0.94 at a pitch ratio of 1 at an angle of 30°.

This paper numerically investigates the effect of the transverse magnetic field on flow field patterns and heat transfer processes in a tilted square cavity. The horizontal walls of the enclosure are assumed to be insulated while the vertical walls are kept isothermal. The power law control volume approach is developed to solve the conservation equations at Prandtl number of 0.71. Validation tests with existing data demonstrate the ability of the present scheme to produce accurate results. The effects of Grashof number, enclosure inclination angle, and Hartmann number are also investigated. The study covers the range of the Hartmann number from 0 to 100, the enclosure inclination angle from 0° to ‐90° with Grashof number of 10⁴ and 10⁶. The effect of the magnetic field is found to suppress the convection currents and heat transfer inside the cavity. This effect is significant for low inclination angles and high Grashof numbers. Additionally, it is noted that there is no variation of average Nusselt number with respect to inclination angle for high Hartmann number.

The purpose of this paper is to propose correlations between Nusselt and Rayleigh numbers for the case of inclined and closed air-filled hemispherical cavities. The disk of such cavities is subjected to a constant heat flux. The study covers a wide range of Rayleigh numbers from 5×107 to 2.55×1012.

Correlations are obtained from numerical approach validated by experimental measurements on some configurations, valid for several angles of inclination of the cavity between 0° (horizontal disk) and 90° (vertical disk) in steps of 15°.

The statistical analysis of a large number of calculations leads to reliable results covering laminar, transitional and turbulent natural convection heat transfer zones.

The proposed correlations provide solutions for applications in several fields of engineering such as solar energy, aerospace, building, safety and security.

The new relations proposed are the first published for high Rayleigh numbers for this type of geometry. They supplement the knowledge of natural convection in hemispherical inclined cavities and constitute a useful tool for application in various engineering areas as solar energy (thermal collector, still, pyranometer, albedometer, pyrgeometer), aerospace (embarked electronics), building, safety and security (controlling and recording sensors).