The use of non-renewable energy sources such as fossil fuels is very contrary to the concept of sustainable development. The principles of green chemistry can be applied to laboratory work through ...experiments based on environmental issues such as energy. Biodiesel is an alternative fuel to replace fossil fuels which can be made through the process of transesterification of oils. This research aims to apply the principles of green chemistry in biodiesel synthesis experiments; design ing and conduct ing thoughtful and efficient experiments; characterizing biodiesel products and knowing students' responses to green chemistry-based experiments in biodiesel synthesis. The results showed that the principle s of green chemistry were successfully applied in the synthesis of biodiesel. Biodiesel products have a bright yellow colour, pH of 7, and density between 0.866-0.892 g/mL. Water content s range from 1.67-3.3, and acid number s range from 0.69-4.3. 90/10 test s show the results between range 0.5-3% and kinematic viscosity from 4.195 - 4.995. Students showed a positive response of 75.36% in designing experimental procedures for green chemistry-based biodiesel synthesis.
Se describe la construcción de una batería de aluminio-hipoclorito de sodio. La batería fue fabricada a partir de reactivos caseros y materiales obtenidos en el supermercado. El diseño propuesto es ...pequeño, fácil de ensamblar, y la batería, formada por una única celda galvánica, es capaz de encender un diodo led rojo.
Dynamics of Biological Macromolecules by Neutron Scattering provides insight into the study of the dynamics of biological macromolecules by neutron scattering techniques. The applicability of neutron ...scattering to expanding fields of biological studies is very extended and the neutron scattering community is interested in using these unique technologies to their best advantage. The book is focused on recent scientific results on biomolecular motions obtained by using neutron spectroscopy, and also discusses likely directions of future work on biological macromolecular systems while outlining some challenging, hitherto inaccessible problem areas. The Ebook should be very useful for biophysicists, biochemists, experts and non-experts in neutron scattering.
Green Chemistry principles can be used to re-cast traditional Organic chemistry experiments into more guided-inquiry based experiments. Inquiry questions related to green chemistry principles and ...metrics have been incorporated into our laboratory for the development of more guided-inquiry based experiments. Re-casting traditional experiments provides time for guided-inquiry by allowing students to evaluate reaction conditions and wastefulness of reactions. This includes evaluating solvent choices, heating methods, use of renewal materials, and contemplating reactants and products impacts on human health and environment. Students examine the changes as it pertains to green chemistry, the success of the reaction and the potential impacts on the mechanism. Involving students in these discoveries rooted in a guiding question made the Organic experiments guided-inquiry. Students were surveyed about their exposure to green chemistry and guided-inquiry based labs. Examples of some of the re-casted experiments, excerpts from student reports, and student impressions of the theme are presented.
The introduction of the computer into the educational process is a fact. The educational use of new technologies creates a new, more appealing and enjoyable learning environment. The introduction of ...new technologies into school differentiates the role of the professor by giving him/her a guiding character in a process of experiential approach to knowledge. In the present paper a proposal for the teaching of the chemistry module "Simple Colloids" is presented, with the contribution of video recorded educational experiments. Complete experiments on the subject of "Simple Colloids" and their properties are presented, aiming at familiarizing students with this theory
The abstractness of certain chemistry concepts demands the use of appropriate teaching strategies to enable students to construct mental images of the concepts. The concepts include understanding the ...effects of concentration and catalyst on the rate of reaction. The reactions at the molecular level are not visible to human eyes and the use of hazardous chemicals to teach the reactions further had made the learning irrelevant to the students. As an alternative to the existing curriculum, through this study, context-based green chemistry experiments (CBGCEs) were introduced as a laboratory curriculum. Teaching using CBGCEs began with unfolding a relevant context and followed with an investigation using benign green chemistry experiments. The qualitative interviews and responses to the issue-based open-ended questions show that students exposed to CBGCEs and existing curriculum attained better understanding about the effects of concentration and catalyst on the rate of reaction. However, the themes emerged from the responses of students learned with CBGCEs portray that this group of students has attained more specific and scientifically adequate understanding. The quantitative findings substantiated the findings obtained from the qualitative data.
Three-dimensional virtual worlds are potentially feasible for building virtual educational environments. However, educators face technical challenges to apply these technologies because creating ...virtual educational environments based on virtual worlds demands 3D modeling and programming skills. This paper proposes a method to lower the technical barriers through domain-oriented interfaces with languages and environments that are familiar to educators. A domain-oriented end-user design environment,
iVirtualWorld
, is designed and developed to implement the proposed method in a specific educational domain, namely introductory chemistry experiments. This web-based environment provides end-users with domain-oriented building blocks, which can be assembled to create 3D virtual chemistry experiments. A usability evaluation and a comparative case study are designed to evaluate the system among chemistry educators, who are the target audience. The usability evaluation contains a task requiring participants to create a 3D virtual chemistry experiment and a voluntary semi-structured interview. The case study compares a virtual experiment generated using
iVirtualWorld
with an experiment in a commercial virtual chemistry laboratory system. The results show that 1) the domain-oriented end-user design environment enables participants to generate the 3D virtual chemistry experiment within 30 min; 2) participants gain confidence on creating 3D virtual experiments by themselves using
iVirtualWorld
; 3) participants confirm the usefulness of applying the system in introductory chemistry education; and 4)
iVirtualWorld
is considered more intuitive and straightforward for students to focus on finishing the experiment without being distracted than the commercial virtual chemistry laboratory system. Areas that can benefit from the system most and areas where the system is less effective are identified by participants. The responses also reveal the limitations of the current system and suggest directions for future improvement.
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