Biomass derived mesoporous carbon monoliths via an evaporation-induced self-assembly

Evaporation-induced self-assembly has been applied in the synthesis of crack-free mesoporous carbon monolith with good mechanical stability using a waste plant material as carbon precursor and triblock copolymer F127 as template. The carbon monolith was characterized using transmission electron microscopy, scanning electron microscopy, nitrogen adsorption–desorption measurement, X-ray diffraction and Fourier transform infrared spectroscopy. The results showed that the carbon monolith is mesoporous, has a surface area of 219 m²/g, and a narrow pore size distribution of 6.5 nm

Evaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection

Capacitively coupled contactless conductivity detection (C4D) is presented as a novel and versatile means of visualising discrete zones of charged functional groups grafted onto polymer based monoliths. Monoliths were formed within 100 μm UV transparent fused silica capillaries and photografting methods were subsequently used to graft a charged functional monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto discrete regions of the “generic” monolith using a photomask. Post-modification monolith evaluation involves scanning the C4D detector along the length of the monolith to obtain a profile of the exact spatial location of grafted charged functionalities with millimetre accuracy. The methodology was extended to the visualisation of several zones of immobilised protein (bovine serum albumin) using photografted azlactone groups to enable covalent attachment of the protein to the monolith at precise locations along its length. In addition, the extent of non-specific binding of protein to the ungrafted regions of the monolith due to hydrophobic interactions could be monitored as an increase in background conductivity of the stationary phase. Finally, the technique was cross-validated using fluorescence microscopy by immobilising green fluorescent protein (GFP) in discrete zones and comparing the profiles obtained using both complementary techniques

Separation of oxidatively damaged DNA Nucleobases and Nucleosides on Packed and Monolith C18 Columns by HPLC-UV-EC

This study involves the incorporation of a commercially available Phenomenex Onyx C18 monolith column into the separation and detection of oxidative DNA damage. It includes thorough investigation of monolith performance and a comparison of the performance of monolith columns with a commercially available packed Restek reverse phase Ultra C18 column for the separation of DNA bases and nucleosides. The performance of the monolith was examined using efficiency, resolution, plate height, asymmetry and retention times, and in each case showed improved or at least comparable results in the separation of a mix of DNA bases and nucleosides. A 90% reduction, from just under 40 min. to just under 4 min., was obtained in the elution time of this separation. To the best of our knowledge, this is the first report of a fast monolith column separation successfully coupled to both a UV-vis and EC detector, which is especially useful for analysis of oxidative DNA damage. The determination of 8-oxoG and 8-OH-dG, oxidation products of guanine and 2’-deoxyguanosine, respectively, may be compromised by their ease of oxidation and therefore the fast separation, selective and sensitive detection, with no artifactual oxidation, detailed in this report, is ideal

Positron detection in silica monoliths for miniaturised quality control of PET radiotracers

We demonstrate the use of the miniaturised Medipix positron sensor for detection of the clinical PET radiotracer, [⁶⁸Ga]gallium-citrate, on a silica-based monolith, towards microfluidic quality control. The system achieved a far superior signal-to-noise ratio compared to conventional sodium iodide-based radio-HPLC detection and allowed real-time visualisation of positrons in the monolith

Design of catalytic monoliths for closed-cycle carbon dioxide lasers

Pulsed carbon dioxide (CO2) lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers in hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalyst and design methods for implementation of catalysts in CO2 laser systems. A monolith catalyst section model and associated design computer program, LASCAT, are presented to assist in the design of a monolith catalyst section of a closed cycle CO2 laser system. Using LASCAT,the designer is able to specify a number of system parameters and determine the monolith section performance. Trade-offs between the catalyst activity, catalyst dimensions, monolith dimensions, pressure drop, O2 conversion, and other variables can be explored and adjusted to meet system design specifications. An introduction describes a typical closed-cycle CO2 system, and indicates some advantages of a closed cycle laser system over an open cycle system and some advantages of monolith support over other types of supports. The development and use of a monolith catalyst model is presented. The results of a design study and a discussion of general design rules are given

The MONOLITH project

MONOLITH is a proposed massive (34 kt) magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to establish (or reject) the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The Delta m^2 sensitivity range for this measurement comfortably covers the complete Super-Kamiokande allowed region. Other measurements include studies of matter effects and the NC/CC and anti-nu/nu ratio, the study of cosmic ray muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending on approval, data taking with part of the detector could start in 2004. The detector and its performance are described, and its potential later use as a neutrino factory detector is addressed.Comment: 6 pages. Contribution to NUFACT'00 neutrino factory workshop, Monterey, CA, USA, May 22-26, 200

MONOLITH: a high resolution neutrino oscillation experiment

MONOLITH is a proposed massive magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to test the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The sensitivity range for this measurement comfortably covers the entire Super-Kamiokande allowed region. Other measurements include studies of matter effects, the NC/CC and neutrino/anti-neutrino ratio with atmospheric neutrinos and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending on approval, data taking with part of the detector could start in 2005. The MONOLITH detector and its performance are described.Comment: 8 pages, contribution to Les rencontres de Physique de la Vallee d'Aoste, March 200

A comparative study of MPPT and voltage regulator controllers for controlling output voltage in PV applications

The demand for renewable energy sources is more and more increasing on each passing year. Since with the increasing number of the human population, the demand for energy is increasing at an alarming state. Petroleum resources are very limited and in this scenario, renewable energy sources such as solar energy proven to be a much more reliable source of energy generation through solar panel technology but getting the most power out of a solar power system is a complicated task and need advanced digital control system and high efficient algorithms. Many algorithms have been developed for the maximum power point tracking (MPPT) of solar panels. However, most of the algorithms such as artificial intelligence and expert systems need high-end computing systems, which are costly and thus not suitable for normal household utilization. In this research, Perturb and Observe (P&O) algorithm with a PI controller algorithm are selected to enhance the MPPT task over the conventional method. This algorithm needs voltage and a current sensor to sense the power parameters of the panel in real time and generate a small difference in duty cycle called perturbation and a boost converter increase or decrease the voltage level based on the PWM signals until the system reach very close to the maximum power point possible. One flaw of this algorithm is that the system never stops at a fixed power point, rather it perturbs around the maximum power range. For further tuning the maximum power point, voltage amplitude and minimize the distortion, a PI controller will be utilized in this research project. Initial results from the solar panel model using SLG-M 350 module are satisfactory. Furthermore, the model has been tested with boost converter circuit in Simulink with a constant duty cycle. Afterward proposed MPPT+PI algorithm results have been compared with simple MPPT method. It is observed that a PI controller minimize the perturbation effect of the MPPT controller largely, which results in less distorted power curves. Additionally, overall power efficiency is increased in the case of proposed MPPT+PI controller, which is 98.5% as compared to 97.8% efficiency of conventional MPPT controller