Room temperature hydrogen gas sensing properties of mono dispersed platinum nanoparticles on graphene-like carbon-wrapped carbon nanotubes

We present platinum nanoparticles dispersed wrinkled graphene-like carbon-wrapped carbon nanotubes (Pt/GCNTs) as a room temperature chemiresistive hydrogen gas sensor. Pt nanoparticles are decorated over GCNTs surface using poly (sodium 4-styrene sulfonate) (PSS) functionalization, followed by ethylene glycol reduction method. The highly defective wrinkled graphene-like surface of GCNTs provides large surface area and PSS functionalization provides stable immobilization of mono dispersed Pt nanoparticles on the carbon surface. A simple and inexpensive drop cast technique is used to fabricate the thick film sensor of the material. Hydrogen resistive gas sensing properties of Pt/GCNTs are studied at different gas concentrations, temperatures and Pt wt. % loadings. Pt/GCNTs sensor shows optimal sensitivity at room temperature with stable and reproducible response towards hydrogen. The sensor with 2 wt. % of Pt showed maximum sensitivity that is three fold higher than Pt decorated carbon nanotubes (Pt/CNTs) with the same Pt wt. % loading. The present study shows potential to explore novel H2 sensors^.     

The Effects of Mobile Phone on the Socio-economic Life of the Rural Dwellers in the Niger Delta Region of Nigeria

This article aims to provide information on the effects of the mobile phone on the socio-economic life of the rural dwellers in the Niger Delta region of Nigeria. The study adopted a semi-structured interview method. The study covered nine villages selected from Delta and Bayelsa States in the Niger Delta region of Nigeria. Convenience sampling technique was used to select 129 respondents who voluntarily agreed to participate in the study. The interview was tape recorded and the information collected from the tape recordings were transcribed and coded. Similar viewpoints toward the same question were put together for the analysis. The study revealed that the mobile phone has brought immerse socio-economic impact on the rural dwellers in the Niger Delta region of Nigeria. The study revealed that mobile phone use enable the rural dwellers to communicate with family members and friends in urban areas; relatives in urban areas send recharge cards for them to sell for money instead of traveling to meet them, and Call Center Operators become self-employed and through that make a living. Finally, the frequent recharging of mobile phones leads to indebtedness. The participants mentioned challenges such as network failure, non-availability of recharge cards, unreliable or complete absence of power supply to charge batteries, high charges by Network Service Providers, stealing of mobile phones, and unskilled persons repairing phones in rural areas. The introduction of mobile phones has lead to reduction of rural–urban migration by many jobless youths.     

Video microscopy as an alternative method for somatic cell count in milk

This paper presents an alternative method to estimate somatic cell count (SCC) in cows' milk. SCC is an important indicator in the detection of inflammatory reactions within the udder in cows and Direct Optical Microscopy (DOM) is the present reference method for SCC but, owing to its dependence on human operators, it is extremely costly, time-consuming and potentially subjective. The industrial method of choice is Epifluorescence (EF), which has the potential for impressive throughput and acceptable precision, but requires huge inversions and handling of highly toxic reactives and waste. In this paper, an advantageous method that involves application of a low-cost Video Microscopy (VM) system is analysed and discussed, including a comparison between DOM and VM, and an example of application of both methods to evaluate EF counts. We conclude that VM is sufficiently precise and very cheap to implement and operate.     

From 2D to 3D geodesic-based garment matching

Multimedia Tools and Applications - A new approach for 2D to 3D garment retexturing is proposed based on Gaussian mixture models and thin plate splines (TPS). An automatically segmented garment of...     

Adhesion Maps Using Scanning Force Microscopy Techniques

A technique has been developed that allows a real-time measurement of the lift-off force required to remove a scanning force microscope tip from a substrate. Both topography and adhesion maps are obtained simultaneously, allowing the correlation between topography and adhesion properties to be studied. Quantitative values of important adhesion parameters can be extracted from these data. A number of examples are given which illustrate the utility of this technique.     

A platelet derived growth factor delivery system for bone regeneration

platelet derived growth factor (PDGF) was formulated in a calcium phosphate/biodegradable polymer system for local and controlled delivery to enhance bone regeneration. Implants with a porosity of 67 %, composed of hydroxyapatite, PLGA microspheres and Pluronic(?), were obtained by compression. An increase in porosity with time was expected due to Pluronic(?) dissolution and PLGA microsphere degradation. In vivo PDGF release and tissue distribution were monitored after system implantation into femurs of rabbits using (125)I-PDGF. Most of the PDGF was released within approximately 5 days and remained located around the implantation site with negligible systemic exposure. Compared with the reference groups, an important enhancement of bone regeneration was found with doses of 600 and 1,200 ng of PDGF, although no histological differences were observed between the two doses. In conclusion, the elaborated system exhibited good biocompatibility and offered a physiologically relevant PDGF profile that enhances bone formation compared to the non-treated bone defect.     

Reordering,recrystallization and recovery behaviour of (Co0.78Fe0.22)3V as a function of the initial state of order

The ordering kinetics of the L1₂ alloy (Co_0.78Fe_0.22)₃V have been studied on annealing below the order-disorder transition temperature and starting from different initial conditions induced by different thermo-mechanical treatments. The results obtained are reported in two parts. In Part I, we have determined by means of dilatometric, resistometric and calorimetric analysis, the relevant temperatures and energies dissipated in the transformations, and how the rates are affected by the initial conditions and annealing temperatures. The variation of hardness and the long-range order parameter have also been measured. The results obtained suggest that the overall kinetics are dependent on the way in which ordering, recrystallization and recovery phenomena occur at different temperatures and on how they affect each other.     

Low-temperature scanning tunnelling microscopy and spectroscopy on Pb and Au

We have designed and built a scanning tunnelling microscope (STM) in order to work at temperatures ranging from 1·2 to 300 K. Tunnelling spectroscopy has been performed in Au and Pb with this STM. Our results on Au show different conductance-voltage behaviours, their relation with the cleaning state of the tip being discussed. For Pb, the fitting of our I-V characteristics to a BCS density of states gives A = 1·25 meV for the superconducting energy gap at about 5 K.