Bandwidth in bolometric interferometry

Bolometric Interferometry is a technology currently under development that will be first dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers in order to be competitive with imaging experiments. A crucial concern is that interferometers are presumed to be importantly affected by a spoiling effect known as bandwidth smearing. In this paper, we investigate how the bandwidth modifies the work principle of a bolometric interferometer and how it affects its sensitivity to the CMB angular power spectra. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. Using an angular power spectrum estimator accounting for the bandwidth, we finally calculate the sensitivity of a broadband bolometric interferometer. A numerical simulation has been performed and confirms the analytical results. We conclude (i) that broadband bolometric interferometers allow broadband visibilities to be reconstructed whatever the kind of phase shifters used and (ii) that for dedicated B-mode bolometric interferometers, the sensitivity loss due to bandwidth smearing is quite acceptable, even for wideband instruments (a factor 2 loss for a typical 20% bandwidth experiment).Comment: 13 pages, 14 figures, submitted to A&

18 GHz SZ measurements of the bullet cluster

We present 18 GHz observations of the Bullet cluster using the Austalia Telescope Compact Array (ATCA), which show structure in the Sunyaev–Zeldovich effect; in particular, a deep, compact feature which does not correspond to any bright feature in X-ray, optical or lensing maps. In general, the relatively deeper SZE features appear to avoid the regions with the most intense X-ray emission. SZE displaced from X-ray centres implies that modeling cluster dynamics is non-trivial. The SZE distribution in the western parts of the cluster are co-spatial with the radio halo indicative of a common origin for the hot and relativistic electrons in the turbulent wake of the Bullet

Determination Of Heavy Metals In Brewer’s Spent Grains Obtained From Benue Brewery Limited (BBL), Makurdi, North Central Nigeria.

The concentration of some heavy metals (Mn, Pb, Cu, Cr, Fe, Zn, Ni and Cd) in spent grains obtained from Benue Brewery Limited, Makurdi North Central was determined using Atomic Absorption Spectrophotometers (AAS). The results show the concentration of the metals as follows: Cr (0.197ppm), Cu (0.185ppm), Cd (0.039ppm), Fe (0.929ppm), Mn (1.235ppm), Ni (0.197ppm), Pb (0.265ppm) and Zn (34.478ppm). Comparison of the concentration of these heavy metals in the spent grains with those of the international/national standards of heavy metals for food, vegetables, cereals and drinking water shows that all but Zn was above allowable limit whereas, the concentrations of other metals analyzed were found to be below the standard maximum permissible limits. This shows that the spent grains are to a certain extent suitable for use as a source of feed formulation for animals and locally made fertilizer for plants. Key words: Spent grains, Heavy metals, Concentration, AAS. Food industry, Benue brewery

AWARENESS, KNOWLEDGE AND ATTITUDE ABOUT DENGUE AMONG SOCIETY

Objective: The survey about dengue was carried out to gather the information about dengue fever, create awareness among the people. To determined the index of knowledge, attitude and awareness among the surveyed population about dengue. Methods: The questionnaire was prepared under the guidance of a pharmacologist. Pilot study was conducted among ten nos. of the population prior actual study. Questionnaire was revised and finalized according to an input of the pilot study. This questionnaire presented to the hundred peoples of different age group. Method involves face to face interview and seeking answers for different questions. Responses were recorded for further analysis and interpretation. Responses were sorted and analyzed. Different questions were categorized into the domain of awareness, knowledge and attitude. Data was presented in the form of graphs. Results: Percentage of awareness, knowledge and attitude found to be 59, 44, 52 respectively. It is observed that three parameters are almost in the range of fifty percent. Precautions plays vital role in prevention of Dengue. Conclusion: it is concluded that there is scope for improvement for creating awareness, knowledge and attitude among the surveyed population as representative of the general population. This may help to overcome the risk of this communicable and deadly disease

Bandwidth in Bolometric Interferometry

Context. Bolometric interferometry is a promising new technology with potential applications to the detection of B-mode polarization fluctuations of the cosmic microwave background (CMB). A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers to be competitive with imaging experiments. A crucial concern is that interferometers are assumed to be significantly affected by a spoiling effect known as bandwidth smearing. Aims. We investigate how the bandwidth modifies the work principle of a bolometric interferometer and affects its sensitivity to the CMB angular power spectra. Methods. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. If the phase shifters produce shifts that are constant with respect to frequency, the instrument works like its monochromatic version (the modulation matrix is not modified), while if they vary (linearly or otherwise) with respect to frequency, one has to perform a special reconstruction scheme, which allows the visibilities to be reconstructed in frequency subbands. Using an angular power spectrum estimator that accounts for the bandwidth, we finally calculate the sensitivity of a broadband bolometric interferometer. A numerical simulation is performed that confirms the analytical results. Results. We conclude that (i) broadband bolometric interferometers allow broadband visibilities to be reconstructed regardless of the type of phase shifters used and (ii) for dedicated B-mode bolometric interferometers, the sensitivity loss caused by bandwidth smearing is quite acceptable, even for wideband instruments (a factor of 2 loss for a typical 20% bandwidth experiment)

Physico-Chemical and Microbiological Analysis of Fermented Cow Milk (Nono) Consumed Within Kaduna Town, North-Western Nigeria

10 Samples of two different types of fermented cow milk tsala (locally prepared diluted milk) and kindrimo (locally prepared concentrated milk) were collected from different locations around Kaduna metropolis, and analyzed for their physicochemical properties and microbiological quality.  The average levels of major chemical components were for: tsala: acidity (0.106%), protein (2.732%), fat (6.54%), total solid (7.68%), ash content (0.638%), and carbohydrate (82.80%); and for kindirmo: acidity (0.122%), protein (3.59%), fat (8.2%), total solid (10.06%), ash content (0.436%) and carbohydrate (77.70%). The average pH values obtained were   (4.09) and (4.42) respectively. The bacteria isolated includes; staphylococcus spp, lactobacillus spp, streptococcus spp, shigella spp, enterobacter, salmonella spp, protein Spp and mirococcus Spp. The fungi isolated included Aspergillus, yest, trichoderma, mucor and cardida. The result of the microbial count revealed that the total aerobic count on tsala ranged between 3 x 103 – 25 x 103 cfu/ml, while for Kindirmo the value ranged between 3 x 103 – 24 x 103 cfu/ml with sample 2E recording too numerous aerobic bacteria count. The coliform count on tsala ranged between 4 x 103 – 10 x 103 while kindirmo recorded a ranged of 1 x 103 – 25 x 103 cfu/ml. The fungi count in tsala ranged between 22 x 103 – 28 x 103 cfu/ml while that of kindirmo ranged between 10 x 103 – 22 x 103 cfu/ml.   The microbiological quality of the two fermented cow milk shows a high level of bacteriological contamination which may pose public health threat and indicates poor hygienic practices and therefore the need for improved hygienic standards. Keywords: microbiological quality, Physico-chemical composition, tsala, kindirmo, Kaduna