Recent developments in dry hot syngas cleaning processes

The dry hot syngas cleaning process appears to be potentially more efficient and cleaner than the proven wet cleaning or semi-wet cleaning processes but it is still far from commercialisation. There are several technological barriers responsible such as poor availability factor, degeneration of sorbent and several stages of separation. This paper summarises the reported current status of dry hot cleaning of syngas from coal gasification processes along with the shortcomings of reporting of dry hot syngas cleaning performance results. The paper also proposes and discusses a rational method of performance reporting, a novel pulse less filtration concept and a system to prevent failure of filter elements.     

Phosphorus feeding levels and critical control points on dairy farms

A viable and cost-effective approach to managing P on dairy farms is to minimize excess P in diets, which in turn leads to less excretion of P in manure without impairing animal performance. A questionnaire survey was conducted, coupled with on-site feed and fecal sample collection and analysis on dairy farms in New York, Pennsylvania, Delaware, Maryland, and Virginia. The purpose was to assess dietary P levels and to identify critical control points pertaining to P feeding management. Survey responses, 612 out of 2500 randomly selected farms, revealed a wide range of dietary P concentrations for lactating cows, from 3.6 to 7.0 g/kg of feed DM. The mean was 4.4 g/kg, which was 34% above the level recommended by the NRC for 27.9 kg milk/d, the mean milk yield in the survey. Higher P concentrations in diets were not associated with higher milk yields (n = 98, R2 = 0.057 for the survey farms; n = 92, R2 = 0.043 for farms selected for on-site sampling). However, higher dietary P led to higher P excretion in feces (n = 75, R2 = 0.429), with much of the increased fecal P being water soluble. Phosphorus concentrations in diet samples matched closely with P concentrations in formulated rations, with 67% of the feed samples deviating <10% from the formulations. On 84% of the survey farms, ration formulation was provided by professionals rather than producers themselves. Most producers were feeding more P than cows needed because it was recommended in the rations by these consultants. In conclusion, P fed to lactating cows averaged 34% above NRC recommendations; to reduce excess dietary P, ration formulation is the critical control point.     

Production of surfactant protein C in the baculovirus expression system: the information required for correct folding and palmitoylation of SP-C is contained within the mature sequence

Surfactant protein C (SP-C) is synthesized in the alveolar type II cells of the lung as a 21 kDa propeptide which is proteolytically processed to a 4.2 kDa mature active form. The main function of this extremely hydrophobic protein is to enhance lipid insertion into the air/liquid interface in the lung upon inhalation. This is necessary to maintain a relatively low surface tension at this interface during breathing. In this report we describe the production of mature human SP-C in the baculovirus expression system. The recombinant protein contains a secondary structure with a high alpha-helical content (73%), comparable to native SP-C, as determined by circular dichroism and attenuated total reflection Fourier transform infrared analysis. The expressed protein is a mixture of dipalmitoylated (15%) and non-palmitoylated SP-C. This suggests that the information required for palmitoylation is contained within the sequence of the mature protein. The activity of the protein to insert phospholipids into a preformed monolayer of lipids at an air/liquid interface was determined with a captive bubble surfactometer. Recombinant SP-C significantly reduced the surface tension at the air/liquid interface during dynamic expansion and compression. We conclude that correctly folded, dipalmitoylated and active SP-C can be expressed in the baculovirus expression system. Our results may facilitate investigations into the relation between structure and function of SP-C and into protein palmitoylation in general.     

Production of hydrogen and light hydrocarbons as a potential gaseous fuel from microwave-heated pyrolysis of waste automotive engine oil

Waste automotive engine oil was pyrolyzed in a continuous stirred bed reactor using microwave energy as the heat source; the yield and characteristics of the incondensable gaseous products are discussed. The recovered gases (41 wt% yield) were found to contain substantial concentrations of light aliphatic hydrocarbons (up to 86 vol.%) that could potentially be used as a chemical feedstock or a fuel source to power the process, or to be reformed to produce hydrogen for use as a second-generation fuel. Examination of the composition of the gases also showed the formation of H₂ (up to 19 vol.%) and CO that could also be used as a valuable syngas (with a H₂ + CO content of up to 35 vol.%). The high yield of gaseous hydrocarbons can be attributed to the unique heating mode and chemical environment present during microwave-heated pyrolysis. The use of a microwave-heated bed of particulate-carbon showed advantages in transforming waste oil into valuable gases. Hence an environmentally unfriendly waste material can be transformed into a useful resource and serves as an alternative source of hydrogen or hydrocarbon energy. The recovery of valuable gases shows advantage over traditional destructive approaches and suggests excellent potential for recycling problematic waste oil.     

Patient specific identification of the cardiac driver function in a cardiovascular system model

The cardiac muscle activation or driver function, is a major determinant of cardiovascular dynamics, and is often approximated by the ratio of the left ventricle pressure to the left ventricle volume. In an intensive care unit, the left ventricle pressure is usually never measured, and the left ventricle volume is only measured occasionally by echocardiography, so is not available real-time. This paper develops a method for identifying the driver function based on correlates with geometrical features in the aortic pressure waveform. The method is included in an overall cardiovascular modelling approach, and is clinically validated on a porcine model of pulmonary embolism. For validation a comparison is done between the optimized parameters for a baseline model, which uses the direct measurements of the left ventricle pressure and volume, and the optimized parameters from the approximated driver function. The parameters do not significantly change between the two approaches thus showing that the patient specific approach to identifying the driver function is valid, and has potential clinically.     

Abnormalities of auditory evoked magnetic fields and structural changes in the left hemisphere of male schizophrenics--a magnetoencephalographic-magnetic resonance imaging study

Functional and structural changes in 10 DSM-III-R male schizophrenics and 10 healthy volunteers were investigated using magnetoencephalographically (MEG) detected long-latency (N100 m) auditory evoked fields (AEFs) and magnetic resonance imaging (MRI). The AEFs were characterized by single moving equivalent dipoles, which were superimposed on MRIs. There were significant differences in dipole orientations and in AEF latencies in the left hemisphere of schizophrenics, when compared to the controls. The MEG-detected alterations were found to be associated with a bilateral volume reduction of the posterior superior temporal gyrus (pSTG), which was more pronounced in the left hemisphere. Separate analysis of white and gray matter has shown that the pSTG volume reduction resulted from decreased gray matter volumes without white matter changes. Both the functional and the morphological data indicate a left-hemispheric disturbance in our patients.