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The utilisation of renewable energy sources for generating electricity and potable water is one of the most sustainable approaches in the current scenario. Therefore, the current research aims to design and develop a novel co-generation system to address the electricity and potable water needs of rural areas.

The cogeneration system mainly consists of a solar parabolic dish concentrator (SPDC) system with a concentrated photo-voltaic module at the receiver for electricity generation. It is further integrated with a low-temperature thermal desalination (LTTD) system for generating potable water. Also, a novel corn cob filtration system is introduced for the pre-treatment to reduce the salt content in seawater before circulating it into the receiver of the SPDC system. The designed novel co-generation system has been numerically and experimentally tested to analyse the performance at Karaikal, U.T. of Puducherry, India.

Because of the pre-treatment with a corn cob, the scale formation in the pipes of the SPDC system is significantly reduced, which enhances the efficiency of the system. It is observed that the conductivity, pH and TDS of seawater are reduced significantly after the pre-treatment by the corncob filtration system. Also, the integrated system is capable of generating 6–8 litres of potable water per day.

The integration of the corncob filtration system reduced the scaling formation compared to the general circulation of water in the hoses. Also, the integrated SPDC and LTTD systems are comparatively economical to generate higher yields of clean water than solar stills.

The rest-to-rest movements for a spacecraft, such as attitude adjustment and orbital manoeuver, are likely to excite residual vibration of flexible appendages, which may affect the attitude accuracy and even result in severe structural damage. The purpose of this paper is to present an approach to attenuating the vibration of flexible solar array by using reaction flywheel.

The reaction flywheel installed on solar array served as an actuator to provide reaction torque to a structure according to a designed feedback control law. This torque can be considered as an artificial damping. Experiment on a scale model of the solar array is first performed to verify the effectiveness of this method. Numerical simulation on finite element model of a full-scale solar array is subsequently carried out to confirm the validity of this method for practical engineering application.

The vibration suppression effect on the structure using a reaction flywheel is deduced by theoretical analysis. Results from both experiment and numerical simulation reveal that the efficiency of vibration attenuation is promoted.

Improvements on control law are left for further study. Additionally, only the first-order bending vibration of the flexible solar array is attenuated, and further study is required for other types of vibration suppression.

An effective method is proposed for spacecraft designers to actively suppress the vibration of the flexible solar array.

A novel active vibration reduction scheme is proposed using a reaction flywheel to suppress vibration of the flexible solar array. This paper fulfils a source of theoretical analysis and experimental studies for vibration reduction measure design and provides practical help for the spacecraft designers.

The purpose of this paper is to implement coating system by varying the amount of nano-sized titanium dioxide, (nano-TiO₂) combined with various organic binders and to study the coating effects on the performance of solar cell in terms of temperature and efficiency.

Nano-TiO₂ coatings are developed in two types of binder networks; the combination of methyltrimethoxy silane (MTMS) and nitric acid and the combination of 3-aminopropyl triethoxysilane (APTES) and MTMS. Overall, the formulations method was cost-effective, produces good transparency, clear and managed to dry at room temperature. The coating mixtures were applied onto the glass substrate by using the dip-coating method and the coated substrate were sent for several characterizations.

This study demonstrated that TiO₂ nanoparticle coating in APTES/MTMS matrix showed a thermal-decreasing result on solar cells, where the cell temperature is reduced to 46.81°C (T₂ coating type) from 55.74°C (without coating) after 1-h exposure under 1,000 W/m² irradiance in a solar simulator. Contrary to prior works where solar cell coatings were reported to reduce the cell temperature at the expense of the cell efficiency, the results from this study reported an improved fill factor (FF) of solar cells. From the photovoltaic (PV) characteristics study, the FF for solar cells is increased by approximately 0.2, i.e. 33.3 per cent, for all coatings compared to the non-coated cell.

Findings will be able to contribute in the development of temperature-reducing and efficiency-enhancing coating for PV panels.

A simple dip-coating method provides an even distribution of TiO₂ nanoparticle coating on the glass panel, which is cost-effective and time-efficient to reduce the temperature of solar cell while maintaining its efficiency.

The ability of nano-TiO₂ coatings with a simple fabrication method and the right solution to reduce the surface temperature of solar cells while improving the FF of the cells.

Occupant behavior can lead to considerable uncertainties in thermal comfort and air quality within buildings. To tackle this challenge, the use of probabilistic controls to simulate occupant behavior has emerged as a potential solution. This study seeks to analyze the performance of free-running households by examining adaptive thermal comfort and CO2 concentration, both crucial variables in indoor air quality. The investigation of indoor environment dynamics caused by the occupants' behavior, especially after the COVID-19 pandemic, became increasingly important. Specifically, it investigates 13 distinct window and shading control strategies in courtyard houses to identify the factors that prompt occupants to interact with shading and windows and determine which control approach effectively minimizes the performance gap.

This paper compares commonly used deterministic and probabilistic control functions and their effects on occupant comfort and indoor air quality in four zones surrounding a courtyard. The zones are differentiated by windows facing the courtyard. The study utilizes the energy management system (EMS) functionality of EnergyPlus within an algorithmic interface called Ladybug Tools. By modifying geometrical dimensions, orientation, window-to-wall ratio (WWR) and window operable fraction, a total of 465 cases are analyzed to identify effective control scenarios. According to the literature, these factors were selected because of their potential significant impact on occupants’ thermal comfort and indoor air quality, in addition to the natural ventilation flow rate. Additionally, the Random Forest algorithm is employed to estimate the individual impact of each control scenario on indoor thermal comfort and air quality metrics, including operative temperature and CO2 concentration.

The findings of the study confirmed that both deterministic and probabilistic window control algorithms were effective in reducing thermal discomfort hours, with reductions of 56.7 and 41.1%, respectively. Deterministic shading controls resulted in a reduction of 18.5%. Implementing the window control strategies led to a significant decrease of 87.8% in indoor CO2 concentration. The sensitivity analysis revealed that outdoor temperature exhibited the strongest positive correlation with indoor operative temperature while showing a negative correlation with indoor CO2 concentration. Furthermore, zone orientation and length were identified as the most influential design variables in achieving the desired performance outcomes.

It’s important to acknowledge the limitations of this study. Firstly, the potential impact of air circulation through the central zone was not considered. Secondly, the investigated control scenarios may have different impacts on air-conditioned buildings, especially when considering energy consumption. Thirdly, the study heavily relied on simulation tools and algorithms, which may limit its real-world applicability. The accuracy of the simulations depends on the quality of the input data and the assumptions made in the models. Fourthly, the case study is hypothetical in nature to be able to compare different control scenarios and their implications. Lastly, the comparative analysis was limited to a specific climate, which may restrict the generalizability of the findings in different climates.

Occupant behavior represents a significant source of uncertainty, particularly during the early stages of design. This study aims to offer a comparative analysis of various deterministic and probabilistic control scenarios that are based on occupant behavior. The study evaluates the effectiveness and validity of these proposed control scenarios, providing valuable insights for design decision-making.

Historically, the study of the world’s economy was classified into Micro-economics and Macro-economics. Perhaps, contemporary economists should learn from the universe which we are part of. Let us name this as “Uni-economics.” Many scientists have found that sunspots affect human behavior. Some research findings even relate the 11-year periodic cycle to war and peace of mankind. It is also widely known in the medical profession that sunspot radiation actually affects our human body. With all these evidence in mind, the purpose of this paper is to investigate how sunspot activities can affect business growth since 1960s when the global economy was building up fast since the Second World War.

The econometrics methodology deployed is in three steps. First, time series techniques were deployed to track down the changes of Sunspot Counts over the last 48 years on the world’s four main financial indices, i.e., S & P, FTSE, Nikkei and HSI. Second, the long run function of a particular stock price index could be specified as a natural logarithm transformation function. Finally, Granger’s co-integration methodology is deployed to test the equilibrium relationships.

This paper has harnessed a set of system and process that can ensure the long-term productivity and business growth of firms in this contemporary business world. It is predicted with 80 percent confidence that the next property depression in some affluent cities will happen in 2014/2015, with the global financial tsunami coming in 2019.

More important is how organizations can make use of the trade-wind and avoid the counter-wind from the Uni-economics phenomena for their quality, productivity and business growth, in accordance to the Deming Cycle. As recalled from the previous two oil crisis (around 1975, 1986) and the two financial tsunami (1997 and 2008), 40-year-old organizations that can still survive today must have done something good, despite all these turmoil confronting them.

The endurance of small unmanned air vehicles (UAVs) is directly associated with the energy density of the propulsion system used. As the batteries commonly used in small UAVs have a relatively low energy density, they are not sufficient for long-term endurance tasks. The purpose of this paper is to offer a solution to increase the endurance of a concept small UAV with combination of different power sources. The design, construction and ground tests of fuel cell-powered hybrid propulsion systems are presented in this paper.

The power requirements of a concept UAV were calculated according to aerodynamic calculations and then, hybrid propulsion system sources are determined. The hybrid system consists of a 100 W scale proton-exchange membrane (PEM) type fuel cell stack, lithium-polymer battery, solar cells and power management system (PMS). Subsequently, this hybrid power system was integrated with the new design of PMS and then series of ground tests were carried out.

This experimental study proved that it is theoretically possible to obtain an endurance of around 3 h for concept UAV with the proposed hybrid system.

The research study shows that fuel cell-based hybrid propulsion system with the proposed PMS can be widely used to obtain extended endurance in small UAVs.

A hybrid propulsion system with a novel PMS unit is proposed for small UAVs and the ground tests were implemented.

A bibliographic system has been developed at the University of Petroleum and Minerals, Dhahran, Saudi Arabia, for gathering, organizing and disseminating the solar energy information pertaining to the Middle East. This paper presents the structure of the system, and some facts and findings on solar energy information based upon analysis of the bibliography.

Personal thermal management by controlling the radiation energies of both the body and the sun can be used in all environments and contributes to sustainability components with the advantages of energy saving, low chemical usage and comfort enhancements under dynamic conditions. In this study, passive radiative heating nanocomposite films were produced using sodium alginate as the matrix and zinc oxide (ZnO) and aluminum oxide (Al₂O₃) nanoparticles as nanofillers having far infrared radiation reflecting, hence passive heating functions.

Nanocomposite film solutions were prepared by stirring sodium alginate powder, deionized water, ZnO and Al₂O₃ nanoparticles (20% wt of matrix polymer) with surfactant using magnetic and ultrasonic stirrers in turn. Films produced within Petri dishes after drying at room temperature were analyzed by FT-IR, UV-VIS-NIR spectroscopy and SEM for chemical, radiation management and morphological characteristics, respectively. Emissivity values giving idea about the heating performances of the films were determined with an IR camera and a hotplate system. Moreover, direct heating performances were measured by the hotplate system including a far-infrared lamp.

Results showed that the emissivity of the films increased by approximately 18% and 16% with ZnO and Al₂O₃ nanoparticles, respectively. Moreover, NaAlg–Al₂O₃ nanocomposite film exhibited passive radiative heating performance of 3.58 °C, higher than the heating performance of NaAlg–ZnO nanocomposite film which is 2.97 °C when compared to the reference NaAlg film. These results indicate that both NaAlg–ZnO and especially NaAlg–Al₂O₃ nanocomposite films have excellent far-infrared emission and absorption properties ensuring a significant heating effect.

In addition to other clothing types, the heating performance obtained with the produced nanocomposite structures may be applied to different types of cosmetic/medical applications (beauty mask, wound dresses, etc.) enabling skincare/healing with the advantage of the sodium alginate matrix.

The harsh environment of space, especially radiation of direct solar rays, can potentially raise the temperature of the spacecraft to harmful levels. Thermal control coatings (TCCs) fix the thermal condition of the spacecraft acceptable for its components. This is possible by diffusely reflecting all effective ultraviolet (UV), visible (VIS) and near infrared (IR) (NIR) wavelengths of solar radiation and emmition of IR energy. The most commonly used TCCs have used ZnO as a pigment, but absorption of the UV light by ZnO pigment can change the ideal condition of these TCCs. The aim of his study is the using the porous ZnO particles as pigment to prevent the UV absorption.

To enhance the efficiency of these coatings, in the present study, nano-porous zinc oxide particles were synthesized and used as pigments for white TCCs.

The results revealed that the proposed TCC (TPZ), Thermal control coating with porous ZnO had better reflection (scattering) and emittance properties in comparison with the coating using ZnO as a pigment (TZ coating); so this coating had a solar absorptance value equal to 0.141, whereas this value for TZ was 0.150. Furthermore, TPZ showed higher thermal emittance (0.937) in comparison with TZ (0.9). These changes were because of the improvement in the refractive index, shape and surface area of the pigments. The general trend of the scattering coefficients for the prepared coating, as calculated from the Kubelka–Munk equation, showed that scattering was more efficient in the UV region, as compared with the TCC containing ZnO pigments.

This type of pigment for the first time is evaluated in TCCs.

In recent years, high‐altitude/long‐endurance airship platforms have generated great interest as a means to provide communications and surveillance capabilities. The purpose of this paper is to develop a model for airship conceptual design and help provide insight into the viability of high‐altitude/long‐endurance airships.

A configuration analysis model with the consideration of pressure difference, temperature difference, and helium purity, etc. was developed. The influences of the airship payload, size and area required of solar cell with environment and operation parameters, such as operation latitude, pressure difference, temperature difference, helium purity, seasons, latitude, and wind speed, etc. were analyzed.

The results show that the area of solar cell required for stratospheric airship is very large under the condition of low altitude, high latitude, wind, and in winter, etc. which might make the design of high‐altitude/long‐endurance airship an elusive goal. They also show that the solar cell efficiency is the key technology in the control of solar cell area required for airships, and the technology advances in regenerative fuel cells and propeller efficiency have significant effects among on the airship payload, size, and solar cell area required for airship.

The paper analyses the energy balance of the high‐altitude/long‐endurance airship.