Juniper Publishers Journal Of Material Science

Abstract Keywords: Hemp bio-aggregates; Hemp concrete; Thermal conductivity; Low impact; Variability Go to Mini Review The impact of Hemp Bio-Aggregates (HBA) on Hemp Concrete (HC) have been treated in previous studies [1-2]. In those studies, used HBA are of limited variability. Moreover, the considered properties are mainly based on particle size and HBA origin. Since many parameters (curing conditions, the specimen size, etc.) are taken into account at the same time, it comes difficult to assess the impact of HBA due to parameter interferences. The present study focuses on the thermal conductivity variability of HC due to HBA. The selection procedure for nine HBA has been developed in a previous study [3] in which different characteristics is taken into account. The aim was to predict the imapct of HBA on HC performance. The study revealed three categories of HBA, which are supposed to result in three mechanical performances (high, medium and low) of HC. Thus, it i...

Abstract Multivalent Pr doped ceria is a potential candidate for SOFCs due to its mixed electronic and ionic conductivity. The valence state of Pr significantly affects the lattice parameter of Pr doped ceria. The lattice parameter mainly depends on the dopant concentration, sintering and switching of valence state. The concentration oxygen vacancies are responsible for ionic conductivity and the oxidation of Pr3+ to Pr4+ is the origin of electronic conductivity. The electronic conductivity increases with the doping concentration and the oxygen partial pressure. Keywords: Pr doped ceria; Mixed conductivity; Oxygen partial pressure Go to Introduction Cubic fluorite structured ceria doped with lower valent cations forms exceedingly oxygen vacancies in the doped ceria lattice. Therefore rare earth doped ceria exhibits high oxygen conductivity at elevated temperatures, which makes it potential candidate for solid electrolyte in intermediate temperature solid oxide fuel cells ...

Abstract Transformations of high-molecular-weight compounds of bituminous sands natural bitumen under the heat treatment are studied. Cracking and extraction of Kazakhstan’s bituminous sand bitumen were carried out. Thermal processing of natural bitumen leads to a general change in the chemical composition of components and an increase in the output of certain factions. Molecular structures of the tar and asphaltene components of natural bitumen are built from the data of elemental analysis, 1HNMR spectroscopy and molecular weight. The content of oil, tar and asphaltenes were determined and the elemental composition of tar-asphaltene compounds was evaluated. The high molecular compounds were presented as giant molecules containing small aromatic islands with some linked by aliphatic chains. Keywords: Natural bitumen; Asphaltene tar; Molecular structure; Fourier transform infrared spectroscopy (FTIR) Go to Introduction One of the areas of increasing the resource base of hy...

With recent advances in biotechnology, there has been a plethora of biomaterials in the form of various dental materials and maxillofacial implants, being routinely used for comprehensive oral rehabilitation. Even though these have considerably enhanced the treatment outcomes, but at times the improper application and lack of safety precaution with these have raised many moral and ethical issues. Due to commercial and marketing pressures, technological developments in biomaterials have led to ethical issues being conveniently buried. Lack of stringent regulations and want of strict institutional control results in products that are not truly safe for patients to be marketed and used by unsuspecting clinicians. Clinicians need to be aware of the various bio-safety aspects of the biomaterials that are commonly in use and also ensure that the patients’ rights of informed consent, beneficence, non-malfeasance and autonomy are protected. There is an urgent need for all healthcare spe...