Colour error reduction in video systems

The problems of achieving color fidelity in video systems are reviewed. Usually a correction matrix is appropriate for one illumination environment, but not necessarily others. A wide range of situations is examined, and, by use of 16 test colors, a matrix can be derived which gives good colorimetry for each. However, as the signal/noise ratio may be degraded, a matrix may be derived which gives a good compromise between noise performance and accurate color rendition. Some color environments are similar, so that ultimately only eight correction matrices are necessary. The noise performance, in terms of the display signal/noise ratio, is determined, and it is shown to be modified by about 1.5 dB for most situations. It is expected that this concept will lead to fully compensating color video cameras     

Investigation of factors in the optimisation of penicillin production

Penicillin production trials were carried out in stirred 5-dm³ fermenters to collect data and investigate aspects of the process likely to be important in on-line optimisation. These included the calculation of growth from the production of carbon dioxide, the relation between age and productivity and the effect of dilution and culture replacement. Three types of media were used, a synthetic medium and complex commercial-type nutrient media based on corn-steep liquor or peanut meal together with a nutrient feed and pH control. All gave good results although the synthetic medium tended to show only transient production on some occasions. An equation was devised enabling the correct calculation of the growth curve from carbon dioxide output. It was found that the maintenance energy requirements (as indicated by CO₂ production) were much higher with synthetic medium than with complex media. Decay curves (of Q_pen vs time) were readily calculated using Shu's¹⁷ equation. The highest outputs of penicillin were obtained by dilution or replacement systems, but it was essential to start the process early when the penicillin-producing enzymes were active and stable. It was also necessary to supply glucose at an adequate rate, to hold dissolved oxygen concentration above 25% and avoid too high cell concentrations. It was concluded that theories of penicillin production based on feed-rate or dilution, or on the effect of age, are essentially complementary, both aspects being important in determining the optimal course of the fermentation.     

The effect of a single dose of mifepristone (RU486) on the fine structure of the human endometrium during the early luteal phase

This study examined the fine structure of the human endometrial glandular epithelium after the administration of a single dose of RU486 (mifepristone), given in the early luteal phase. The drug was administered on days 2, 3, 5 and 6 after the luteinizing hormone peak (LH + 0). Biopsies were performed on days LH + 5, 6, 8 and 9. These were compared with control biopsies taken on corresponding days. Qualitatively, the main cytological effect of the RU486 was on the secretory apparatus and on the polarity of the cell. The formation of the nuclear channel system was also affected by the drug. A two-way analysis of variance on cell and nuclear volume data revealed no significant effect of day of biopsy, condition or interaction. Mitochondrial volume and secretory apparatus volume data revealed a significant effect of day of biopsy and interaction term; mitochondrial volume at LH + 5 was 95.9 +/- 25.3 microm3 (mean +/- SD) for control and 57.7 +/- 31.9 microm3 for RU486-treated epithelium. The volume of the secretory apparatus in the treated group was smaller on days LH + 5 and 6 (14.6 +/- 4.2 microm3, 6.41 +/- microm3) when compared to day-matched control biopsies (35.9 +/- 10.5 microm3, 41.7 +/- 26.4 microm3). RU486 administration in the early luteal phase disrupted the secretory activity of the cells. These findings provide an insight into the cellular mechanisms of progesterone receptor blockade in the peri-implantation period.     

Polyimides from a Novel Monomer 3,6-Bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a Catalytic Application

Tricyclic heteroaraomatic dye-based monomer containing NMe₂ units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl₂(p-cymene)]₂ and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-bis(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192–278 °C, and the 10% weight loss temperatures were above 503–635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-1-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC).     

Exact and approximate error-rate analysis of BPSK in Weibull fading with cochannel interference

The performance of binary phase shift keying in a Weibull fading environment is analysed in the presence of cochannel interference (CCI) in terms of the bit error rate (BER). We derive an exact expression for the BER in this case on the basis of a characteristic function approach. Furthermore, since it is difficult to obtain the distribution of the CCI and because of the complexity of the obtained exact BER expression, we derive an approximate expression for the BER by invoking the central limit theorem. The validity of the exact expression and the accuracy of the approximate one are verified by comparing their results with those obtained via Monte Carlo simulations. The effect of such factors as the number of interferers and the fading severity of both the desired as well as the interfering signals on performance is also investigated.     

A pragmatic pairwise group-decision method for selection of sites for nuclear power plants

A pragmatic pairwise group-decision approach is applied to compare two regions in order to select the more suitable one for construction of nuclear power plants in the Kingdom of Saudi Arabia. The selection methodology is based on pairwise comparison by forced choice. The method facilitates rating of the regions or sites using simple calculations. Two regions, one close to Dhahran on the Arabian Gulf and another close to Jeddah on the Red Sea, are evaluated. No specific site in either region is considered at this stage. The comparison is based on a set of selection criteria which include (i) topography, (ii) geology, (iii) seismology, (iv) meteorology, (v) oceanography, (vi) hydrology and (vii) proximetry to oil and gas fields. The comparison shows that the Jeddah region is more suitable than the Dhahran region.     

Impact of a desalination plant on the physical and chemical properties of seawater, Bahrain

The impact of effluent from the Sitra power and desalination plant (SPDP), Bahrain, on the physical and chemical properties of the receiving water was investigated. Two distinguished zones of the receiving water were recognized. These zones resulted from the presence of the jetty. The length of the first zone is about the same length as the jetty, 70 m. The length of the second zone extends to about 150 m. Seventy five case stations were selected on the receiving water. On the intake side, fifteen stations were considered as control stations. The SPDP effluent significantly changed the temperature and salinity of the receiving water of the first zone. The dissolved oxygen levels vary slightly from the control stations. The jetty was found to restrict the water circulation of the first zone. This restriction caused a delay in the temperature, salinity and dissolved oxygen dispersion. Beyond the first zone, this restriction is removed and the dispersion processes affected the control stations.     

Sex pheromones inCulicoides nubeculosus (diptera,ceratopogonidae): Possible sites of production and emission

This study was performed on virgin females ofCulicoides nubeculosus to determine sites of production and emission of sex pheromone. The ventral abdominal surface is the site of emission of the pheromone. Morphologically there is evidence of the presence of abdominal atrichial areas. The abdominal areas, eight per segment (four ventral and four dorsal), are covered by a cuticle devoid of micro- and macrotrichiae. The dorsal and ventral areas differ considerably in their structure. The dorsal atrichial areas have an unperforated cuticle covering a normal epidermis, whereas the ventral atrichial areas have a cuticle perforated by numerous tubular structures, with a loosely organized procuticle and no underlying epidermal cells. A pair of voluminous cells with the classical ultrastructural characteristics of enocytes is invariably located in the vicinity of the ventral atrichial areas. These cells undergo ultrastructural modifications tending towards involution according to the age of the insects, being correlated with the decrease in pheromone emission by older females. The hypothesis is put forward that enocytes are involved in pheromone production.     

The flavour components of plums: An examination of the aroma components present in the headspace above four cultivars of intact plums,marjorie's seedling,merton gem,NA 10 and victoria

Qualitative and quantitative examination of the aromas above four cultivars of intact plums, using gas chromatography and gas chromatography-mass spectrometry, gave information on 33 components of which linalool, benzaldehyde, methyl cinnamate and y-decalactone were present in regions of the chromatogram associated with plum-like aromas. Comparison of the analytical data with the scoring of plum-like character by sensory means showed that the percentage concentration of these compounds only related approximately to the sensory scores, whereas the percentage of hexanol, the major component present in the extracts, was inversely related.