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The production of biohydrogen from rice mill wastes, including rice bran and rice mill effluent by Clostridium acetobutylicum NCIM 2877 was investigated in a batch culture system and optimized the temperature and pH conditions. At 35 °C with initial pH of 5.2 a yield of 55.7±0.8 ml with 88.6 ± 0.3% substrate utilization and at pH 6 the production was 68.7 ± 0.9 ml with 85 ± 1.0 % substrate utilization. Addition of metal ions resulted in better yield and substrate utilization efficiency of the bacteria. FeSO₄.7H₂O at a concentration of 50 mg/l gave 79.7 ± 1.5 ml with 96% of substrate utilization. Cobalt effected the production greatly by giving 96.3 ± 0.9 ml with 95.3 ± 0.7% of substrate utilization whereas Nickel didn’t showed much effective results by giving only a maximum of 74.7 ± 1.5 ml production at 25 mg/l concentration. Conclusively, it can be stated that rice mill wastes can be used as a substrate and use of metal ions will play a key role in the enhancement of biohydrogen production.

Currently, experimental and theoretical work is being performed to ensure that biofuels from microalgae become a reality. However, there is a considerable number of discussions concerning in which processes should be focussed efforts of research and development. The purpose of this paper is to provide decision support not only to help build guidelines of research to be undertaken, but also to contribute to the design of more adequate policy and funding instruments. The key objective of this study is to determine the prospects of employing microalgae into the production of biofuels within a time scale extending to 2030.

The Delphi method is a qualitative research aiming to support strategic future-oriented action, such as policy making in the areas of science and technology. It is especially appropriate in judgment and long-range forecasting (20-30 years) situations, when expert opinions are often the only source of information available, due to a lack of appropriate historical, economic or technical data.

The Delphi method proved to be a successful research method when expert opinions are the main source of information available, due to a lack of appropriate historical, economic or technical data and the outcomes provided a clear outline of the main issues of microalgae biofuels’ market at present and in the future.

The outcomes might not represent the majority of the microalgae experts’ opinion due to the sample size.

The work presented in this paper is especially original. According to the authors’ knowledge, this is the first qualitative Delphi study related to algae biofuels.

This paper aims to map the evolution of hydrogen-based technologies (HBTs) by examining the patenting activity associated to these technlogies from 1930 to 2020. In doing so, the study provides a novel perspective on the development of HBTs and offers implications for managers and policymakers.

We collected patent data at the level of patent families (PFs). Our sample includes 317,089 PFs related to hydrogen production and 62,496 PFs to hydrogen storage. We examined PF data to delineate the state of the art and major technical advancements of HBTs.

Our analysis provides evidence of an increasing patenting activity in the area of HBTs, hence suggesting relatively high levels of expectations on the economic potential of these technologies. US and Japan hold the largest proportion of PFs related to HBTs (about 60%), while European applicants hold the highest proportion of highly cited PFs (about 60%). While firms represent the applicant with the highest share of PFs, our analysis reveals that firms holding HBT PFs are primarily from the chemical sector.

While our analysis is limited to examining patent data which capture some aspects of the innovation activity around HBTs (namelly, patented inventions), our study enriches existing literature by performinng a patent analysis on a much larger sample of data when compared to previous studies.

Two main implications emerge from our study. Firstly, there seems to be an urgent need to support the emergence of a dominant design so as to facilitate the consolidation and diffusion of the HBTs, hence the transition to a more sustainable energy production. Secondly, the majority of HBT PFs are held by a small number of countries. This, in turn, suggests opportunities to develop cross-country cooperation (e.g. international agreements, research and technology offices) to support the development and adoption of HBTs globally.

Considering the results obtained in this study, from a social point of view, the attention that organizations have paid to hydrogen related technologies is evident. This suggests that the development HBTs can function as a social enabler for a sustianable energy transition.

Extant research has focused on the individual components of the hydrogen chain. As a result, we lack a comprehensive understanding of the progress made in the area of HBTs. To address this gap, this study examined HBTs by focusing on both production and storage technologies since their initial developments, hence adopting an observation period of about 70 years.

The world is increasingly threatened by climate change. As the dimensions of this danger grow, it becomes essential to develop the most effective policies to mitigate its impacts and adapt to these new conditions. Technology is one of the most crucial components of this process, and this study focuses on examining climate change adaptation technologies. The aim of the study is to investigate the entire spectrum of technology actors and to concentrate on the technology citation network established from the past to the present, aiming to identify the core actors within this structure and provide a more comprehensive outlook.

The study explores patent citation relationships using social network analysis. It utilizes patent data published between 2000 and 2023 and registered by the US Patent and Trademark Office.

Study findings reveal that technologies related to greenhouse technologies in agriculture, technologies for combatting vector-borne diseases in the health sector, rainwater harvesting technologies for water management, and urban green infrastructure technologies for infrastructure systems emerge as the most suitable technologies for adaptation. For instance, greenhouse technologies hold significant potential for sustainable agricultural production and coping with the adverse effects of climate change. Additionally, ICTs establish intensive connections with nearly all other technologies, thus supporting our efforts in climate change adaptation. These technologies facilitate data collection, analysis, and management, contributing to a better understanding of the impacts of climate change.

Existing patent analysis methods often fall short in detailing the unique contributions of each technology within a technological network. This study addresses this deficiency by comprehensively examining and evaluating each technology within the network, thereby enabling us to better understand how these technologies interact with each other and contribute to the overall technological landscape.

This study seeks the effect on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions of euro diesel-hydrogen dual-fuel combustion in a small turbojet engine.

Experimental studies are performed in a JetCat P80-SE type small turbojet engine. Euro diesel and hydrogen is fed through two different inlets in a common rail distributing fuel to the nozzles. Euro diesel fuel is fed by a liquid fuel pump to the engine, while hydrogen is fed by a fuel-line with a pressure of 5 bars from a gas cylinder with a pressure of approximately 200 bars.

At different engine speeds, it is found that there is a decrease at the TSEC between a range of 1% and 4.8% by different hydrogen energy fractions (HEF).

The amount of hydrogen is adjusted corresponding to a range of 0–20% of the total heat energy of the euro diesel and hydrogen fuels. The small turbojet engine is operated between a range of 35,000 and 95,000 rpm engine speeds.

On the other hand, remarkable improvements in exhaust emissions (i.e. CO, CO₂, HC and NO_x) are observed with HEFs.

This is through providing improvements in performance and exhaust emissions using hydrogen as an alternative to conventional jet fuel in gas turbine engines.

This study aims to find a new alternate source for biodiesel conversion. The alternate source must be easily available, and it should give more oil yield than available edible, inedible sources. To meet the fuel demand in the transportation sector with edible oil-based biodiesel causes food versus fuel crisis. In addition to this, it increases NO_x and CO₂ in the environment.

The present paper reviews the comparison of algae oil yield, fatty acid composition and its biodiesel properties’ effect on diesel engine characteristics.

Algae were the only source to fulfil fuel demand because its oil and biodiesel yield is higher than other sources. Algae can grow by capturing carbon dioxide from the environment, and its fatty acid composition is more suitable to run diesel engines.

There is an improvement in engine performance–emission tradeoff with algal biodiesel.

A new approach in the field of renewable energy is- the microbial fuel cells (MFCs). It is a technique to produce bioelectricity from available organic waste. It is helpful to fulfill the lighting requirements of rural areas. The aim of our research work is to construct twocompartment system and to study various parameters like performance of the different combination of electrodes, optimization of pH and temperature. In this study, using bacteria as biocatalyst, the naturally found cow dung was used to generate an open circuit voltage of 0.84 ± 0.010 V and a current of 3.51 ± 0.620 mA. Optimization of various parameters shows that among different temperature range, 37°C temperature gives the highest voltage production of 0.84 ± 0.091 V and current of 3.08 ± 0.512 mA. In case of pH there are not any significant changes were found when pH range is changed. Although, pH 4.0 is found to be more efficient as it produces voltage of 0.90 ± 0.045 V and current of 4.85 ± 0.587 mA. Furthermore, three electrogenic bacterial strains were isolated and studied for their electrogenic properties individually and among them CDB-3 was found best in their performance.

Chemical reaction effects are added to the governing equation. This paper aims to get the solution by converting the partial differential equation into an ordinary differential equation and solve using a perturbation scheme and applying the boundary conditions.

In this paper, the authors discussed the chemical reaction effects of heat and mass transfer on megnato hydro dynamics free convective rotating flow of a visco-elastic incompressible electrically conducting fluid past a vertical porous plate through a porous medium with suction and heat source. The authors analyze the effect of time dependent fluctuating suction on a visco-elastic fluid flow.

Using variable parameters of the fluid, the velocity, temperature and concentration of the fluid are analyzed through graphs.

The velocity profile reduces by increasing the values of thermal Grashof number (G_r), mass Grashof number (G_c) and the magnetic parameter (M). On the other hand, the velocity profile gets increased by increasing the permeability parameter (K). The temperature profile decreases by raising the value of Prandtl number (P_r) and frequency of oscillation parameter (ω). However, the source parameter (S) has the opposite effect on the temperature profile. The concentration profile reduces in all points by raising the chemical reaction parameter K_l, Schmidt number S_c, frequency of oscillation ω and the time t.

The purpose of the study is to design economical shock tube. It is an instrument used for experimental investigations not only related to shock phenomena but also for the behavior of the material when it is subjected to high-speed flow. The material used here in this shock tube is stainless steel ss304 and aluminum. A shock tube consists of two sections, namely, the driver and the driven. The gas in the driven and driver is filled with atmospheric air and nitrogen, respectively, under the predominant condition.

The focus of the study is on the design and fabrication of shock tubes. a shock tube is a research tool to make an aerodynamic test in the presence of high pressure and temperature by generating moving normal shock waves under controlled conditions.

The main necessity for instrumentation in the shock tube experiment is to know the velocity of the moving shock wave from which the other parameters can be calculated. the pressure transducers are located in the shock tube in various locations to measure aerodynamic parameters in terms of pressure.

The main objective of this project work is to make an experimental setup to produce supersonic velocity with the readily available material in the market in a highly safe manner.

The purpose of this paper is to find the pressure and the knocking phenomena. To get the pressure values, the butterworth bandpass filter was used and the potential of knocking was found by using peak-to-peak pressure values and also the species concentration. Cooled exhaust gas recirculation was the method used to minimize the knocking occurrence in the engine. Moreover, the effect of premixed methanol and start of engine (SOI) on knocking were also determined.

This paper deals with the compression ignition engine to investigate the unfavorable knocking behavior. The tests were carried out with the 3D model of engine fueled with waste cooking oil blended with TiO2. A number of tests were taken to find the pressure variation and the species concentration at eight different locations in the computational model.

In doing the tests, the positive intended outcome was achieved. From results, it is clear that the SOI and premixed methanol mitigated the knocking process.

The species concentration and pressure in the form of filtered signal were proved to be the ideal methods for evaluating the knocking event in the engine.