Continuous, self-sustaining smouldering destruction of simulated faeces

A new approach for the rapid destruction of human waste using smouldering combustion is presented. Recently, self-sustaining smouldering combustion was shown to destroy the organic component of simulated human solid waste and dog faeces resulting in the sanitization of all pathogens using a batch process (Yermán et al., 2015). Here, a continuous smouldering process is demonstrated for the first time, allowing for a much smaller reactor size and much less energy input per mass of waste treated. The self-sustained smouldering of simulated human faeces mixed with sand is evaluated over long periods (more than 16 h) based on a single ignition. The key process of intermittent self-sustained smouldering, in which the reaction is terminated and restarted by only turning the air off and on, is demonstrated. Experiments examine the influence of two key operator controls: airflow rate and set elevation of the quasi-steady-state smouldering front in a 37 cm high reactor. Quasi-steady-state fuel destruction rates from 93 g/h to 12 g/h were achieved by varying the superficial flow velocity from 7.4 cm/s to 0.11 cm/s, the latter with a velocity approximately an order of magnitude lower than possible for a self-sustaining reaction in an equivalent batch system. Excess energy of up to 140 J/g of sand was recovered from the clean sand produced in each cycle, which could be used to further increase the energy efficiency of this novel waste treatment system

Изменчивость биомассы дождевых червей (Lumbricidae) как отклик биоты на различные экологические условия в модельных экспериментах

В експерименті вивчено вплив різних варіантів субстратів, які використовують у лісовій рекультивації, підстилок із листя деревних порід та зволоження на представників грунтових сапрофагів (Lumbricidae). Встановлено достовірний вплив субстратів, підстилок та зволоження на збільшення біомаси дощових черв'яків.Influence of various soil blends used in forest rehabilitation, leaf litters of trees, and humidity levels on soil saprophages (Lumbricidae) is experimentally studied. Significant influence of substrates, litters, and humidity levels on the increase of earthworms' biomass has been determined

Modeling energy consumption for the generation of microfibres from bleached kraft pulp fibres in a PFI mill

The objective of this paper is to model the energy consumed in generating cellulose microfibres, 1 μm in diameter, as reinforcing agents, by refining bleached softwood kraft pulp in a PFI mill. An average initial fibre diameter of 13 μm was assumed. 125,000 revolutions in a PFI mill was found to produce a high yield of fibres 1.3 μm in diameter, and the minimum refining energy needed to reduce the fibre diameter to 1.3 μm was estimated as 1875 kJ for each 24 g charge in the PFI mill. Since elastic deformation of the fibres was found to be negligible, the size reduction was assumed to follow Rittinger’s Law. This gave a Rittinger’s constant of 28 J.m/kg for the given system. Using this value of Rittinger’s constant, the energy required to generate microfibres 1 μm in diameter was predicted as 2480 kJ for each 24 g charge in the PFI mill. It was deduced that microfibres generated in this way would cost a minimum of $2.37 per kilogram. Hence even this relatively inefficient method of grinding would not be prohibitively expensive, provided the resulting microfibres can be used as high quality reinforcements

Phase behavior and structure of a new colloidal model system of bowl-shaped particles

We study the phase behavior of bowl-shaped (nano)particles using confocal microscopy and computer simulations. Experimentally, we find the formation of a wormlike fluid phase in which the bowl-shaped particles have a strong tendency to stack on top of each other. However, using free energy calculations in computer simulations, we show that the wormlike phase is out-ofequilibrium and that the columnar phase is thermodynamically stable for sufficiently deep bowls and high densities. In addition, we employ a novel technique based on simulated annealing to predict the crystal structures for shallow bowls. We find four exotic new crystal structures and we determine their region of stability using free energy calculations. We discuss the implications of our results for the development of materials consisting of molecular mesogens or nanoparticles

A differential dielectric spectroscopy setup to measure the electric dipole moment and net charge of colloidal quantum dots

A sensitive dielectric spectroscopy setup is built to measure the response of nanoparticles dispersed in a liquid to an alternating electric field over a frequency range from 10-2 to 107 Hz. The measured complex permittivity spectrum records both the rotational dynamics due to a permanent electric dipole moment and the translational dynamics due to net charges. The setup consists of a half-transparent capacitor connected in a bridge circuit, which is balanced on pure solvent only, using a software-controlled compensating voltage. In this way, the measured signal is dominated by the contributions of the nanoparticles rather than by the solvent. We demonstrate the performance of the setup with measurements on a dispersion of colloidal CdSe quantum dots in the apolar liquid decalin

A differential dielectric spectroscopy setup to measure the electric dipole moment and net charge of colloidal quantum dots

A sensitive dielectric spectroscopy setup is built to measure the response of nanoparticles dispersed in a liquid to an alternating electric field over a frequency range from 10-2 to 107 Hz. The measured complex permittivity spectrum records both the rotational dynamics due to a permanent electric dipole moment and the translational dynamics due to net charges. The setup consists of a half-transparent capacitor connected in a bridge circuit, which is balanced on pure solvent only, using a software-controlled compensating voltage. In this way, the measured signal is dominated by the contributions of the nanoparticles rather than by the solvent. We demonstrate the performance of the setup with measurements on a dispersion of colloidal CdSe quantum dots in the apolar liquid decalin

The fatigue damage mechanics of notched carbon fibre/ PEEK laminates

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.17(CUED/C-MATS/TR--193) / BLDSC - British Library Document Supply CentreGBUnited Kingdo