Study of Graphitic Crystallites in Some Carbonized Residues Prepared From Catalytic Cracking of Asphalt

This paper demonstrates the carbonization of asphalt collected from the Morgah Oil Refinery, Rawilpindi, Pakistan. The asphalt (80/90) was carbonized in a micro-autoclave under nitrogen environment at 300°C. To enhance cracking reactions of side chains, and condensation of polycyclic configurations, the sample was also loaded with catalysts such as Zeolite Socony Mobil No. 5 (ZSM-5), phosphotungstic acid, coal ash and Utmanzai clay (UTIMAC). Each carbonized residue was crushed with mortar and pestle and soxhlet extracted with n-pentane for removal of oil, dried and analyzed by X-ray diffractometery (XRD). The appearance of distinct bands correspond to crystallites in some samples particularly those loaded with UTIMAC has established graphitization.     

Organochlorine pesticide, polychlorinated biphenyl and heavy metal concentrations in wolves (Canis lupus L. 1758) from north-west Russia

The wolf Canis lupus is a major terrestrial predator in eastern Europe and, as a top carnivore, may be exposed to high concentrations of contaminants that are readily transferred through the food chain. Despite this, there are few published data on pollutant and pesticide levels in wolves. This study utilised tissues from animals legally killed by hunters for other reasons (animals were not killed for the purposes of this study) to carry out the only detailed investigation of contaminants in wolves in Europe and the first in animals from Eastern Europe. The livers of 58 wolves from the Tver and Smoliensk regions of northwest Russia (54°N 31°E to 57°N 35°E) were analysed for seven organochlorine pesticides, 24 PCB congeners, Aroclor 1254-matched summed PCBs (ΣPCBs), total mercury, cadmium and lead. Cadmium, most of the organochlorine pesticides and many PCB congeners were not detectable in any of the wolves. Hexachlorobenzene, alpha-HCH, pp′DDE, PCB congeners 118, 138, 149 and 156 and lead were detected in up to 6% of livers. Dieldrin, PCB congeners 153, 170 and 180, ΣPCBs and mercury were detected more frequently. Contaminant levels were generally low; maximum wet weight concentrations of any of the organochlorine pesticides, ΣPCBs and mercury were less than 0.1, 1 and 0.25 μg g⁻¹, respectively. PCB congeners 153, 170 and 180 accounted for 41% of the ΣPCBs. Dieldrin, ΣPCBs and mercury concentrations did not vary significantly between males and females nor between adult and juvenile (<12 months old) wolves apart from the ΣPCB concentration, which was on average five times higher in adults than juveniles. Liver residues were generally below the level normally associated with adverse effects except for lead levels which exceeded the critical 5 μg g⁻¹ dry wt. concentration in three of the 58 animals examined.     

Mechanical investigation of two fiber-reinforced repair mortars and the repaired system

The mechanical behavior of two repair mortars was investigated. The first one is a fiber reinforced lime-based mortar, which contains thickening agent and limestone additions. The second one is a fiber reinforced ordinary mortar, which contains a small quantity of silica fume and additives. Mechanical characterization was based on compression, tensile and three-point bending tests. The bond between the repair mortars and substrate was investigated by slant shear and flexural bonding tests. The results obtained have demonstrated the influence of the surface roughness and moisture conditions on the bond strength. Finally, Scanning Electron Microscopic observations have showed the morphology of the repair mortar-to-substrate interfacial zone.     

Electrochemical and thermal characterization of doped ceria electrolyte with lanthanum and zirconium

Nanocomposites electrolytes consisting of La³⁺ and Zr⁴⁺ doped with ceria labelled as La_0.2 Ce_0.8 O_2-δ (LDC), Zr_0.2Ce_0.8O_2-δ (ZDC) and Zr_0.2La_0.2Ce_0.6O_2-δ (ZLDC) have been synthesized via a co-precipitation route. DC conductivity was studied with a four-probe method in the range of temperature 450–650 °C and maximum conductivity was found to be 0.81 × 10^?2 S.cm^?1 (LDC) > 0.32 × 10^?2 S.cm^?1 (ZLDC) > 0.15 × 10^?2 S.cm^?1 (ZDC) at a temperature of 650 °C, respectively. Further, electric behavior of doped and co-doped ceria electrolytes was investigated by A.C electrochemical impedance spectroscopy (frequency range ~ 0.1 Hz?4 MHz). The phase/structural identification of the material prepared was studied using X-ray diffraction and found ceria to possess a cubic fluorite structure. Scanning electron microscopy (SEM) was carried out to study its morphology and particle size (~ 90–120 nm). Thermal behavior on its change in weight and length with the temperature were studied by thermogravimetric analysis (TGA) and dilatometry respectively. Furthermore, thermal expansion coefficients (TECs) of prepared electrolytes are calculated and found as follows: 13.4 × 10^?6 °C^?1, 13.6 × 10^?6 °C^?1and 15.3 × 10^?6 °C^?1 for LDC, ZDC and ZLDC, respectively, in the temperature range 150–1150 °C.     

Forensic investigation to detect forgeries in ASF files of contemporary IP cameras

Recent years have seen tremendous increase in crime and terrorism all over the world which has necessitated continuous surveillance of public spaces, commercial entities and residential areas. CCTV cameras are an integral part of any modern surveillance system and have evolved significantly. They are a vital part of any investigation that follows a criminal or terrorism incident by providing invaluable evidence. In this paper, we show that the Advance Systems Format (ASF) file used in most IP cameras, which is also the main file containing metadata about the streaming packets, is vulnerable to forgery. This file is stored in plain text and any technically savvy person can forge it; therefore, a mechanism is needed to prevent it. To that end, we have gathered critical artifacts from an ASF file of IP cameras and carried out their forensic analysis. The analysis performed during this study demonstrates successful detection of forgery/tampering of evidence in IP cameras.     

Quantum mechanical interpretation and analysis of perovskite material based single layer fuel cells (SLFCs)

Fossil fuels are unable to meet the current energy demands and polluting the environment with the emission of harmful gases. Therefore, clean energy technology is need of the modern era. One of the energy conversion devices is fuel cell which utilized fuel from renewable sources and convert into electricity in an efficient and clean way. However, for commercialization of this technology high operating temperature, degradation of electrodes and manufacture cost is the key challenges in conventional three layer fuel cell. Significant improvements have been made to reduce the cost and operating temperature by selecting suitable materials. Therefore, single layer fuel cell (SLFC) has been got much attention due to simple geometry. The mechanism inside the SLFC is still mystery which has been explained in this paper using quantum mechanical parameters like band gap and effect of particle size on charge transportation.In this research work, nanocomposite materials for single layer fuel cell have been synthesized by chemical routes. The x-ray diffraction shows the cubic perovskite structure with average crystallite size in the range of 23–37 nm. The particle size and surface area is found to be 23 nm and 86.42 m² g^?1, respectively. Raman spectrum of LBSCF-SDC shows a red shift compared to LBSCF and band gap of the composition 3LBSCF-7SDC is found to be 2.51 eV. Moreover, the conductivity of the sample 3LBSCF-7SDC has been found to be 0.02 Scm^?1 at 750 °C. The quantum mechanical effects governing the working of single layer fuel cells are observed by different analyses. Photon confinement and Fano-Interactions phenomena resulted in a red shift using Raman analysis technique. The red shift in Raman spectrum is referred to a photon confined in a single layer fuel cell system. These effects are studied in single layer fuel cell for the first time with no previous analyses done in this newly field.