Neutron Detection in the A2 Collaboration Experiment on Neutral Pion Photo-production on Neutron

Neutron detection is of crucial importance for the neutral pion photo-production study on a neutron target that now is in progress at MAMI. Two electro-magnetic calorimeters, based on NaI and BaF2 crystals, are used in the A2 experiment. While these calorimeters are optimized for pion decay photon detection, they have a reason able efficiency for neutron detection also. The paper describes the method, which has been used to measure this efficiency using the same data taken for pion photo-production study on deuterium target with tagged photon been of 800 MeV maximal energy. The detection efficiency is a rising function of neutron momentum that reaches 40% near 1 GeV/c

BIOGAS PURIFICATION WITH CHLORELLA VULGARIS

The article is dedicated to the problem of cleaning biogas from CO2. A literary analysis of the prospect of using the microalga Chlorella vulgaris as an agent in the biological method of biogas purification has been carried out. The possibility of a joint technology for obtaining purified biogas and feed additives in the form of a suspension of microalgae, as valuable components from the point of view of commercial benefits, is considered. The potential for using biogas and the factors constraining the growth of the biogas industry in Russia are assessed.Статья посвящена проблеме очистки биогаза от CO2. Проведен анализ перспектив использования микроводоросли Chlorella vulgaris как агента в биологическом методе очистки биогаза. Рассмотрена возможность совместной технологии для получения очищенного биогаза и кормовых добавок в виде суспензии микроводорослей как ценных компонентов с точки зрения коммерческой выгоды. Оценен потенциал применения биогаза и факторы, сдерживающие рост биогазовой индустрии в России

Multiwalled carbon nanotube destruction in the radiation damages to electron irradiation

Behavior of the X-ray diffraction and vibrational Raman spectra of multiwalled carbon nanotubes (MWCNT) under high-energy electron irradiation (Ee = 1.8 MeV) with large doses of absorption to 10 MGy were studied. With increasing dose uptake to 10.0 MGy, the interlayer correlation in the distribution of the individual graphene nanotubes nets not only is maintained, but is even improved. Defective bands D, D' and G band with increasing dose absorption have significant transformation, which show radiation damages of MWCNT. The destruction of nanotubes under electron irradiation is accompanied by increased regulation in the arrangement of individual nanotubes by interlayer cross-links involving interstitial atoms. The severity of degradation and cross-linking of MWCNT depends on the electron absorption dose

Platinum Based Nanoparticles Produced by a Pulsed Spark Discharge as a Promising Material for Gas Sensors

We have applied spark ablation technology for producing nanoparticles from platinum ingots (purity of 99.97 wt. %) as a feed material by using air as a carrier gas. A maximum production rate of about 400 mg/h was achieved with an energy per pulse of 0.5 J and a pulse repetition rate of 250 Hz. The synthesized nanomaterial, composed of an amorphous platinum oxide PtO (83 wt. %) and a crystalline metallic platinum (17 wt. %), was used for formulating functional colloidal ink. Annealing of the deposited ink at 750 °C resulted in the formation of a polycrystalline material comprising 99.7 wt. % of platinum. To demonstrate the possibility of application of the formulated ink in printed electronics, we have patterned conductive lines and microheaters on alumina substrates and 20 μm thick low-temperature co-fired ceramic (LTCC) membranes with the use of aerosol jet printing technology. The power consumption of microheaters fabricated on LTCC membranes was found to be about 140 mW at a temperature of the hot part of 500 °C, thus allowing one to consider these structures as promising micro-hotplates for metal oxide semiconductor (MOS) gas sensors. The catalytic activity of the synthesized nanoparticles was demonstrated by measuring the resistance transients of the non-sintered microheaters upon exposure to 2500 ppm of hydrogen