Bipolar-Driven Large Magnetoresistance in Silicon

Large linear magnetoresistance (MR) in electron-injected p-type silicon at very low magnetic field is observed experimentally at room temperature. The large linear MR is induced in electron-dominated space-charge transport regime, where the magnetic field modulation of electron-to-hole density ratio controls the MR, as indicated by the magnetic field dependence of Hall coefficient in the silicon device. Contrary to the space-charge-induced MR effect in unipolar silicon device, where the large linear MR is inhomogeneity-induced, our results provide a different insight into the mechanism of large linear MR in non-magnetic semiconductors that is not based on the inhomogeneity model. This approach enables homogeneous semiconductors to exhibit large linear MR at low magnetic fields that until now has only been appearing in semiconductors with strong inhomogeneities.Comment: 23 pages, 4 figures (main text), 6 figures (supplemental material

Effect of Applied Magnetic Field on Surface Morphology, Optical and Electrical Property of Tin (IV) Oxide (SnO2) Nanomaterial for Meat Spoilage Detection

The specter of botcha or “double dead” meat is a persistent, if not underestimated, threat in Filipino markets. In 2014, the National Meat Inspection Service (NMIS) recorded the confiscation of more than 12 metric tons of so-called hot meat, unfit for human consumption. The hazard that consuming this and other forms of spoiled meat poses to human health cannot be overstated, especially because spoiled meat can harbor dangerous pathogens or parasites such as Salmonella, Staphylococcus, Pseudomonas Aeroginosa, and Trichinella

Explaining gender differences in non-fatal suicidal behaviour among adolescents: a population-based study

<p>Abstract</p> <p>Background</p> <p>While suicide is the second leading cause of death among young people in most industrial countries, non-fatal suicidal behaviour is also a very important public health concern among adolescents. The aim of this study was to investigate gender differences in prevalence and emotional and behavioural correlates of suicidal behaviour in a representative school-based sample of adolescents.</p> <p>Methods</p> <p>A cross-sectional design was used to assess suicidal behaviour and various areas of emotional and behavioural problems by using a self-report booklet including the Youth Self-Report. One hundred sixteen schools in a region of Southern Germany agreed to participate. A representative sample of 5,512 ninth-grade students was studied. Mean age was 14.8 years (SD 0.73); 49.8% were female.</p> <p>Results</p> <p>Serious suicidal thoughts were reported by 19.8% of the female students and 10.8% of the females had ever attempted suicide. In the male group, 9.3% had a history of suicidal thoughts and 4.9% had previously attempted suicide. Internalizing emotional and behavioural problems were shown to be higher in the female group (difference of the group means 4.41) while externalizing emotional and behavioural problems slightly predominated in male students (difference of the group means -0.65). However, the total rate of emotional and behavioural problems was significantly higher in the adolescent female group (difference of the group means 4.98). Using logistic regression models with suicidal thoughts or attempted suicide as dependent variables, the pseudo-R² of gender alone was only 2.7% or 2.3%, while it was 30% or 23.2% for emotional and behavioural problems measured by the YSR syndrome scales. By adding gender to the emotional and behavioural problems only an additional 0.3% of information could be explained.</p> <p>Conclusions</p> <p>The findings suggest that gender differences in non-fatal suicidal behaviour among adolescents can to a large extent be explained by the gender differences in emotional and behavioural problems during this age.</p

Magnetic-field-enhanced morphology of tin oxide nanomaterials for gas sensing applications

We studied the effect of an external magnetic field (up to 0.31 T) on the growth of SnO2 nanowires fabricated using the horizontal vapor phase growth (HPVG) technique. The morphology of the nanowires was characterized by using scanning electron microscopy (SEM), and the chemical composition was characterized by energy dispersive X-ray (EDX) analysis. We found that the length of nanowires was significantly enhanced by the application of EMF. The aspect ratio, as well as the density of the fabricated nanowires, increased with increasing magnetic field intensity. Although the physics behind the morphology enhancement of the nanowires under magnetic field is still being investigated, nevertheless, we demonstrated that the magnetic field could be used as a key parameter to control the morphology of tin oxide nanomaterials grown via HPVG technique. The magnetically enhanced nanowires were used in the development of a gas sensor and were found to be sensitive to hydrogen sulfide gas and the headspace gas emitted by spoiling meat. © 2017 Jonathan C. Briones et al

Fabrication of metal oxide sensor for hydrogen sulfide sensing applications

Metal oxide nanomaterials were synthesized via Horizontal Vapor Phase Crystal Growth deposition. Fabricated crystals were characterized using SEM and EDX spectroscopy and were installed in a circuit complete with mini gas chamber where the target gas at varying quantity was allowed to interact with the sensing surface. The sensitivity of the fabricated prototype was tested to hydrogen sulfide (H2S) gas using voltage analysis. Voltage measurements were made to study the response of the metal oxide crystal to the molecules of Hydrogen Sulfide gas. Results denote that the synthesized Tin Oxide nanomaterial sensor substrate is more sensitive and responsive to H2S gas compared to the Zinc Oxide sensor substrate