Laura Monica Gorghiu

Bio: Laura Monica Gorghiu is an academic researcher. The author has contributed to research in topic(s): Science education & Responsible Research and Innovation. The author has an hindex of 11, co-authored 90 publication(s) receiving 484 citation(s).

Problem-based Learning - An Efficient Learning Strategy in the Science Lessons Context☆

Abstract: The research conducted in recent years illustrates that traditional teaching generates a real passivity among students, who are placed in the position of ready-made knowledge consumers, their only effort being oriented to secure and, subsequently, reproduce the knowledge in the context of evaluation tests. Traditional teaching practices may not have a learning effect than a superficial one, which result come as inconsistent and possible to be used only in immediate instructional contexts. In this sense, problem-based learning (PBL) - often known as inquiry-based learning - represents an effective way of working with students who may thus be helped to build basic skills in various domains or curricular areas. Generally, the method involves a central question (problem), proposed and explained by the teacher, with the students working cooperatively and deciding for the proper strategy with the view to solve the problem.The paper presents the results of the implementation in the classroom of 17 Modules which involve problem-based learning paradigm. The Modules were created by teachers enrolled in the continuous professional development programme named “PROFILES - Education through Sciences” , organized in the frame of the Seventh Framework Programme “PROFILES - Professional Reflection Oriented Focus on Inquiry-based Learning and Education through Science” . The feedback collected from teachers and students was positive, with important achievements in students’ understanding of Science concepts, but also in taking ownership of their learning.

The effect of metals on thermal degradation of polyethylenes

Abstract: A chemiluminescence study on thermal degradation of some polyethylenes (LDPE, LLDPE, HDPE, UHMWPE) on seven metal trays in the presence of triazines as stabilisers was carried out. The kinetic effects of metals (Al, Zn, Ti, Mo, Mn, Fe and Cu) were assessed at 200 °C by the calculation of oxidation induction period, half-oxidation time, maximum oxidation time and rate in the propagation stage. Different sequences of catalytic effect provided by the studied metals in LDPE and HDPE are reported. A characteristic copper index for each metal was also calculated. Some considerations on the thermal stability of polyethylenes in intimate contact with metal surfaces are presented.

Chemiluminescence investigation of thermo-oxidative degradation of polyethylenes stabilized with fullerenes

Abstract: The stabilization effect of various carbon materials: [C60]fullerene, three adducts with levopimaric acid, two sorts of carbon black and nanocarbon on HDPE, LDPE and LLDPE have been studied by chemiluminescence at 180, 190 and 200 °C. Kinetic parameters: oxidation induction time, rate of oxidation and activation energy were determined. On the basis of these results some considerations on oxidation prevention mechanism are revealed.

Effect of calixarenes on thermal stability of polyethylenes

Abstract: The thermal degradation of some polyethylenes (one type of high density PE and two of low-density) was studied by isothermal chemiluminescence. Each polymer was stabilized by one of four phenolic additives: p-t-butylphenol (considered as reference), 2,4,6-tri-t-butylphenol, p-t-butylcalix[4]arene, and p-t-butylcalix[6]arene. Six kinetic parameters of thermal oxidation (induction period, maximum oxidation rate, half-period of ageing, maximum CL intensity, maximum degradation time, and activation energy) along with relative activity and stability were calculated. Protection efficiency of additives was evaluated by relative activity and relative stability indexes. Considerations of a stabilization mechanism involving calixarenes are presented.

Application of Problem-based Learning Strategy in Science Lessons – Examples of Good Practice

Abstract: It is widely accepted that in the context of Knowledge-based Society, the educational institutions must demonstrate their ideologically and pragmatic point of views, when discussing the role of the promoters of educational changes. The changes require - among other aspects of pedagogical and psycho-social issues - a reconsideration of what constitutes the effective teaching strategy, adapted to the needs of the learners. Thus, within the Science classes (Chemistry, Physics and Biology), the teaching approach cannot remain an expositional one, based only on the transmission and reception of information. A student-centred educational process, aiming to the development of key-skills, necessarily involves a pro-active approach that facilitates students’ involvement in research, scientific investigation, analysis of problematic situations or solving real problems or merely hypothetical ones. Through its specificity, the Problem-Based Learning (PBL) strategy may be a central component of such teaching approaches. The purpose of the article is to highlight the effectiveness of PBL, through presenting some of the best educational practices implemented by the Romanian Science teachers who participated in the “PROFILES - Education through Science” Continuous Professional Development Programme. The investigative approach is a qualitative one, focused on the analysis of the teaching practices based on PBL implementation, but also on the analysis of students’ and teachers’ opinions who used this strategy in Science lessons. The hypothesis that was stated as a premise of the research took into consideration the fact that when using the PBL teaching strategy during the Science lessons, the students will acquire not only cognitive skills but also a series of instrumental and transversal ones.

Biodegradable Polymers- A Review on Recent Trends and Emerging Perspectives

Abstract: Recent trends in biodegradable polymers indicate significant developments in terms of novel design strategies and engineering to provide advanced polymers with comparably good performance. However, there are several inadequacies in terms of either technology or cost of production especially in the case of applications in environmental pollution. So, there is a need to have a fresh perspective on the design, properties and functions of these polymers with a view to developing strategies for future developments. The paper reviews the present state-of-art on biodegradable polymers and discusses the salient features of the design and properties of biodegradable polymers. Special emphasis is given to the problems and prospects of (1) approaches adopted to make non-biodegradable synthetic polymers such as polyethylene biodegradable and (2) biodegradable polymers and copolymers made from renewable resources especially poly(lactic acid) based polymers and copolymers which are emerging as the candidate biodegradable materials for the future.

Biodegradation of Agricultural Plastic Films: A Critical Review

Abstract: The growing use of plastics in agriculture has enabled farmers to increase their crop production. One major drawback of most polymers used in agriculture is the problem with their disposal, following their useful life-time. Non-degradable polymers, being resistive to degradation (depending on the polymer, additives, conditions etc) tend to accumulate as plastic waste, creating a serious problem of plastic waste management. In cases such plastic waste ends-up in landfills or it is buried in soil, questions are raised about their possible effects on the environment, whether they biodegrade at all, and if they do, what is the rate of (bio?)degradation and what effect the products of (bio?)degradation have on the environment, including the effects of the additives used. Possible degradation of agricultural plastic waste should not result in contamination of the soil and pollution of the environment (including aesthetic pollution or problems with the agricultural products safety). Ideally, a degradable polymer should be fully biodegradable leaving no harmful substances in the environment. Most experts and acceptable standards define a fully biodegradable polymer as a polymer that is completely converted by microorganisms to carbon dioxide, water, mineral and biomass, with no negative environmental impact or ecotoxicity. However, part of the ongoing debate concerns the question of what is an acceptable period of time for the biodegradation to occur and how this is measured. Many polymers that are claimed to be ‘biodegradable’ are in fact ‘bioerodable’, ‘hydrobiodegradable’, ‘photodegradable’, controlled degradable or just partially biodegradable. This review paper attempts to delineate the definition of degradability of polymers used in agriculture. Emphasis is placed on the controversial issues regarding biodegradability of some of these polymers.

Advances in antioxidant active food packaging

Abstract: Lipid oxidation is, together with microbial growth, the main cause of spoilage of a great variety of foods, such as nuts, fish, meats, whole milk powders, sauces and oils. It causes a loss of both sensorial and nutritional quality of foods and may even lead to the formation of toxic aldehydes. Some strategies that are commonly used to limit the extent of lipid oxidation of packaged foods are direct addition of antioxidants or packaging under modified atmospheres in which oxygen presence is limited. A novel alternative to these methods is antioxidant active packaging, whose main advantage is that it can provide sustained release of antioxidants during storage. This article reviews the latest advances in antioxidant active food packaging, with special emphasis on antioxidant release systems. The various methods for incorporating antioxidant compounds in the package, the issues to be considered in packaging design, and the various methods employed to date to evaluate the antioxidant effectiveness of active antioxidant materials are reviewed.

Current state and future prospects of plastic waste as source of fuel: A review

Abstract: Due to the depleting fossil fuel sources such as crude oil, natural gas, and coal, the present rate of economic growth is unsustainable. Therefore, many sources of renewable energy have been exploited, but the potentials of some other sources such as plastics waste are yet to be fully developed as full scale economic activity. Development and modernization have brought about a huge increase in the production of all kinds of plastic commodities, which directly or indirectly generate waste due to their wide range of applications coupled with their versatility of types and relatively low cost. The current scenario of the plastic recycling technology is reviewed in this paper. The aim is to provide the reader with an in-depth analysis with respect to the pyrolysis of plastic waste as obtained in the current recycling technology. As the calorific value of the plastics is comparable to that of hydrocarbon fuel, production of fuel from plastic waste would provide a good opportunity to utilize the waste as a better alternative to dumpsites. Different techniques of converting plastics waste into fuel including thermal and catalytic pyrolysis, microwave-assisted pyrolysis and fluid catalytic cracking are discussed in detail. The co-pyrolysis of plastics waste with biomass is also highlighted. Thus, an attempt was made to address the problem of plastic waste disposal as a partial replacement of the depleting fossil fuel with the hope of promoting a sustainable environment.