PRODUCTION OF COMPOSITE PELLETS FROM WASTE COFFEE GROUNDS, MILL SCALE AND WASTE PRIMARY BATTERY TO PRODUCE FERROMANGANESE; A ZERO WASTE APPROACH

This study was aimed to produce ferromanganese by using waste battery as manganese source, mill scale as iron source and waste coffee ground as reduction agent and carbon source. Waste batteries were collected from waste battery collection bins. Mill scale was collected from hot rolling workshop. Waste coffee grounds were household used coffee. All starting materials were characterized. Weighted raw materials blended with addition of bentonite as a binder. Pelletizing equipment was used to produce composite pellets. Produced pellets were dried then used for reduction experiments. Reduction experiments were conducted in Argon purged tube furnace for 1250 oC, 1300 oC and 1400 oC according to thermodynamic background. Produced ferromanganese samples were characterized for chemical compositions and metallization rate.

Revealing the Thermodynamic Background of the Memory Effect in Phase Separating Cathode Materials

Phase separating Li-ion battery cell cathode materials feature a well-known phenomenon called the memory effect. It manifests itself as an abnormal change in working voltage being dependent on cell cycling history. It was only recently that plausible mechanistic reasoning of the memory effect in Li-ion batteries was proposed. However, the existing literature does still not consistently reveal a phenomenological background for the onset or absence of the memory effect. This paper provides strong experimental and theoretical evidence of the memory effect in phase separating Li-ion battery cathode materials. Specifically, the background leading to the onset or absence of the memory effect and the underlying causal chain of phenomena from the collective particle-by-particle intra-electrode phenomena to macroscopic voltage output of the battery are presented and discussed. The results, clearly reveal that no memory effect is observed and predicted for low cut off voltages, whereas the absence of the first rest in memory writing cycle does not result in the absence of the memory effect, as previously believed. In addition, excellent agreement between the simulated and measured results is shown which, on one hand confirms the credibility of the combined analyses and, on the other, provides clear causal relations from macroscopic experimental parameters to simulated phenomena on the particle level.

Putative Mechanisms Underlying High Inhibitory Activities of Bimodular DNA Aptamers to Thrombin

Nucleic acid aptamers are prospective molecular recognizing elements. Similar to antibodies, aptamers are capable of providing specific recognition due to their spatial structure. However, the apparent simplicity of oligonucleotide folding is often elusive, as there is a balance between several conformations and, in some cases, oligomeric structures. This research is focused on establishing a thermodynamic background and the conformational heterogeneity of aptamers taking a series of thrombin DNA aptamers having G-quadruplex and duplex modules as an example. A series of aptamers with similar modular structures was characterized with spectroscopic and chromatographic techniques, providing examples of the conformational homogeneity of aptamers with high inhibitory activity, as well as a mixture of monomeric and oligomeric species for aptamers with low inhibitory activity. Thermodynamic parameters for aptamer unfolding were calculated, and their correlation with aptamer functional activity was found. Detailed analysis of thrombin complexes with G-quadruplex aptamers bound to exosite I revealed the similarity of the interfaces of aptamers with drastically different affinities to thrombin. It could be suggested that there are some events during complex formation that have a larger impact on the affinity than the states of initial and final macromolecules. Possible mechanisms of the complex formation and a role of the duplex module in the association process are discussed.

Structurization, Phase Rule Diagram, Relaxation Processes and Radio-Absorbing Properties of Solid Solutions Based on a Binary System BaNb2O6-SrNb2O6

The investigation results of the processes of phase formation in barium niobate, strontium, and their solid solutions in the conditions of the variability of the thermodynamic background are presented. The formation of a grain landscape and dielectric properties (including relaxation phenomena) in the solid solutions of strontium niobate and their solid solutions and the establishment of regularities in the formation of radio-absorbing properties in them are studied.

Flipping the classroom and turning the grades – a solution to teach unbeloved phase diagrams to engineering students

Phase diagrams may simply be described as alloying maps in material science. However, the required thermodynamic background knowledge is high level and understanding the cooling procedure of metal melts as well as microstructure of metal alloys is challenging. Common teaching material presents results, but not how to get there and leaves frustrated first year engineering students behind. Knowledge on “how to read” phase diagrams is expected from teachers in advanced courses, but requirements are seldomly met by the students. Teaching phase diagrams in “inverted classroom”szenarios is a method to let the students study the science on their own and then take time to discuss their questions and do extended hands on lectures or exercises in class. Implementing the inverted classroom approach has been proven to be successful in terms of learing outcome, problem solving skills related to phase diagrams and in improving grades. Although the time of preparation is raised by a factor of approximately 4 for 2 four-hour classroom sessions, the positive and sustainable learning outcomes make it fun to teach and worth the effort.