scholarly journals Sustainable Biodiesel Synthesis from Honne-Rubber-Neem Oil Blend with a Novel Mesoporous Base Catalyst Synthesized from a Mixture of Three Agrowastes

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 190 ◽  
Author(s):  
Olayomi A. Falowo ◽  
Tunde V. Ojumu ◽  
Omoniyi Pereao ◽  
Eriola Betiku

Application of solid catalysts synthesized from agricultural wastes provides an environmentally benign and low-cost process path to synthesize biodiesel. An ash containing an equal mixture of cocoa pod husk, plantain peel and kola nut pod husk ashes (CPK) was obtained by open combustion of each of the biomass in air and calcined at 500 °C for 4 h. The calcined CPK ash was characterized to determine its catalytic potential. Two-level transesterification technique was used to synthesize biodiesel using the developed catalyst. The process parameters involved were optimized for the microwave-aided transesterification of a blend of honne, rubber seed and neem oils in a volumetric ratio of 20:20:60, respectively. The study showed that the ash derived from combination of the biomass wastes provided a catalyst which consists all necessary catalytic ingredients in their relative abundance. The calcined CPK consists of 47.67% of potassium, 5.56% calcium and 4.21% magnesium attesting to its heterogenous status. The physisorption isotherms reveals that it was dominantly mesoporous in structure and made up of nanoparticles. A maximum of 98.45 wt.% biodiesel was obtained from a MeOH:oil blend of 12:1, CPK concentration of 1.158 wt.% and reaction time of 6 min under microwave irradiation. The quality of the synthesized biodiesel satisfied the requirements stipulated by standard specifications. Thus, this work demonstrates that a blend of agrowastes and mixtures of non-edible oils could be used to synthesize good quality and sustainable biodiesel that can replace fossil diesel.

2016 ◽  
Vol 22 (4) ◽  
pp. 391-408 ◽  
Author(s):  
Zeljka Kesic ◽  
Ivana Lukic ◽  
Miodrag Zdujic ◽  
Ljiljana Mojovic ◽  
Dejan Skala

Vegetable oils are mainly esters of fatty acids and glycerol, which can be converted to fatty acid methyl esters (FAME), also known as biodiesel, by the transesterification reaction with methanol. In order to attain environmental benignity, a large attention has been focused in the last decades on utilizing heterogeneous catalysts for biodiesel production instead the homogenously catalyzed transesterification of vegetable oil. The pure CaO or CaO mixed with some other metal oxide due to its low solubility in methanol, FAME and glycerol, low cost and availability is one of the most promising among the proposed heterogeneous catalysts. Solid catalysts which contain CaO usually fulfill a number of important requirements, such as high activity at mild temperature, marginal leaching of Ca cations, long life activity, reusability in transesterification of vegetable oil and easy recovery from the final products of transesterification (FAME and glycerol). This review is focused to the recent application of pure CaO or CaO in complex catalyst structure and their use as heterogeneous base catalysts for biodiesel synthesis and suitability for industrial application.


2013 ◽  
Vol 389 ◽  
pp. 46-52 ◽  
Author(s):  
Ben Yong Han ◽  
Tao Li ◽  
Rong Qun Deng ◽  
Xiang Feng Xiong ◽  
Chao Yin Chen

Biodiesel has attracted considerable interest in recent years as an alternative, biodegradable and nonpolluting transportation fuel. Conventional alkaline process for biodiesel production are energy consuming and generate undesirable by-products such as soaps, that make difficult the separation and purification of biodiesel. Ionic liquids as environmentally benign chemical solvent, had been used in diverse chemical reactions. Especially, they could be applied in biodiesel production. Preparation of biodiesel catalyzed by ionic liquids have many merits, such as no corrosion to equipment, no pollution to environment, and reusability. Ionic liquids can improve the catalytic activity and they have wide utilization prospect in biodiesel preparation. In this paper, the advances in the Brønsted ionic liquids catalysts and their application in biodiesel production through transesterification of oils and fats were reviewed. In addition, the prospect for the application of the ionic liquids to catalyze biodiesel production was also stated. Since the cost of ionic liquid may be an issue, there are some challenges to be faced, such as the production of ionic liquids with low cost, easy recovery and with the possibility of reutilization of the catalyst for several cycles.


2013 ◽  
Vol 20 (3) ◽  
pp. 91-106 ◽  
Author(s):  
Rachel Pizarek ◽  
Valeriy Shafiro ◽  
Patricia McCarthy

Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most.


Author(s):  
T. N. Antipova ◽  
D. S. Shiroyan

The system of indicators of quality of carbon-carbon composite material and technological operations of its production is proved in the work. As a result of the experimental studies, with respect to the existing laboratory equipment, the optimal number of cycles of saturation of the reinforcing frame with a carbon matrix is determined. It was found that to obtain a carbon-carbon composite material with a low cost and the required quality indicators, it is necessary to introduce additional parameters of the pitch melt at the impregnation stage.


2020 ◽  
Vol 6 (3) ◽  
pp. 522-525
Author(s):  
Dorina Hasselbeck ◽  
Max B. Schäfer ◽  
Kent W. Stewart ◽  
Peter P. Pott

AbstractMicroscopy enables fast and effective diagnostics. However, in resource-limited regions microscopy is not accessible to everyone. Smartphone-based low-cost microscopes could be a powerful tool for diagnostic and educational purposes. In this paper, the imaging quality of a smartphone-based microscope with four different optical parameters is presented and a systematic overview of the resulting diagnostic applications is given. With the chosen configuration, aiming for a reasonable trade-off, an average resolution of 1.23 μm and a field of view of 1.12 mm2 was achieved. This enables a wide range of diagnostic applications such as the diagnosis of Malaria and other parasitic diseases.


Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 108
Author(s):  
Giancarla Alberti ◽  
Camilla Zanoni ◽  
Vittorio Losi ◽  
Lisa Rita Magnaghi ◽  
Raffaela Biesuz

This review illustrates various types of polymer and nanocomposite polymeric based sensors used in a wide variety of devices. Moreover, it provides an overview of the trends and challenges in sensor research. As fundamental components of new devices, polymers play an important role in sensing applications. Indeed, polymers offer many advantages for sensor technologies: their manufacturing methods are pretty simple, they are relatively low-cost materials, and they can be functionalized and placed on different substrates. Polymers can participate in sensing mechanisms or act as supports for the sensing units. Another good quality of polymer-based materials is that their chemical structure can be modified to enhance their reactivity, biocompatibility, resistance to degradation, and flexibility.


Author(s):  
Nickolay Gantchev ◽  
Mariassunta Giannetti

Abstract We show that there is cross-sectional variation in the quality of shareholder proposals. On average, proposals submitted by the most active individual sponsors are less likely to receive majority support, but they occasionally pass if shareholders mistakenly support them and may even be implemented due to directors’ career concerns. While gadfly proposals destroy shareholder value if they pass, shareholder proposals on average are value enhancing in firms with more informed shareholders. We conclude that more informed voting could increase the benefits associated with shareholder proposals.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dian Gong ◽  
Gaofeng Zeng

AbstractTransition metal oxides are the potential catalysts to replace noble-metal based catalyst for the catalytic combustion of methane due to the tolerable reactivity and low cost. However, these catalysts are challenged by the low temperature reactivity. Herein, the surface defective Co3O4 nanoplates are realized through a facile co-precipitation and thermal reduction method with the association of GO. The resultant catalysts (CoGO50) demonstrate a superior low-temperature reactivity for the methane oxidation to CO2 and H2O in comparison with the common Co3O4 catalyst. The reliable stability of CoGO50 catalyst was proved by 80 h testing with intermittent feeding of water vapor. The experimental analysis demonstrates that the presence of a small amount of GO significantly affects the catalysts in surface valence state, active oxygen species and surface oxygen vacancies through reacting with the cobalt oxide as a reductant. Moreover, GO plays as 2D confine template to form smaller and thinner nanoplates. This work provides a facile method to control the surface properties of catalyst not only for Co3O4 based catalysts but also for wider solid catalysts.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6774
Author(s):  
Francisco José Vivas Fernández ◽  
José Sánchez Segovia ◽  
Ismael Martel Bravo ◽  
Carlos García Ramos ◽  
Daniel Ruiz Castilla ◽  
...  

Although the cure for the SARS-CoV-2 virus (COVID-19) will come in the form of pharmaceutical solutions and/or a vaccine, one of the only ways to face it at present is to guarantee the best quality of health for patients, so that they can overcome the disease on their own. Therefore, and considering that COVID-19 generally causes damage to the respiratory system (in the form of lung infection), it is essential to ensure the best pulmonary ventilation for the patient. However, depending on the severity of the disease and the health condition of the patient, the situation can become critical when the patient has respiratory distress or becomes unable to breathe on his/her own. In that case, the ventilator becomes the lifeline of the patient. This device must keep patients stable until, on their own or with the help of medications, they manage to overcome the lung infection. However, with thousands or hundreds of thousands of infected patients, no country has enough ventilators. If this situation has become critical in the Global North, it has turned disastrous in developing countries, where ventilators are even more scarce. This article shows the race against time of a multidisciplinary research team at the University of Huelva, UHU, southwest of Spain, to develop an inexpensive, multifunctional, and easy-to-manufacture ventilator, which has been named ResUHUrge. The device meets all medical requirements and is developed with open-source hardware and software.


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