The Time Evolution of a Constant Mass of Air Pollutant Emitted by a Point Source

The transient behaviour of a constant mass (i.e. a blob) of pollutant released from a point source at a height, , above ground level at time  is studied. The time dependent atmospheric diffusion equation in the presence of diffusion in both horizontal and vertical directions is used to model the problem. The model is found to be governed by an initial-boundary-value problem for the concentration of the pollutant. The solution is obtained in closed form using integral transform methods. The solution is illustrated graphically using appropriate numerical integrations. As time passes, the pollutant blob moves with a central point of accumulation of pollutant while the blob increases in volume to spread the pollutant around it. The motion of the accumulation point in space and time is strongly influenced by wind and gravity while the spread of the pollutant is governed by diffusion. The time taken by the blob to diffuse into space is estimated as a function of the parameters governing wind, gravity and diffusion

Superfield T-duality rules

A geometric treatment of T-duality as an operation which acts on differential forms in superspace allows us to derive the complete set of T-duality transformation rules which relate the superfield potentials of D=10 type IIA supergravity with those of type IIB supergravity including Ramond-Ramond superfield potentials and fermionic supervielbeins. We show that these rules are consistent with the superspace supergravity constraints.Comment: 24 pages, latex, no figures. V2 misprints corrected. V3. One reference ([30]) and a comment on it ('Notice added') on p. 19 adde

Agronomic Performance of Sunflower (Helianthus annuus L.) to Different Levels of Nitrogen, Sulphur and Farmyard Manure under Temperate Conditions

A field study was conducted to ascertain the impact of nitrogen, sulphur and farmyard manure (FYM) on development dynamics and yield of sunflower (Helianthus annuus L.). Application of 120 kg N ha-1 significantly increased all the yield components viz., plant height, leaf area index, dry matter production, capitulum diameter, achenes capitulum-1 and 1000-seed weight during two years of experimentation. Pooled seed yield over two years and for individual year’s also recorded significant increase, however 80 and 120 kg N ha-1 were statistically similar. The oil content showed consistent decrease with increase in nitrogen levels, whereas oil yield showed significant improvement with increase in nitrogen application up to 120 kg ha-1 during both years. Sulphur application at 60 kg ha-1 significantly increased plant height, leaf area index and dry matter production at various crop growth periods except at 25 DAS over 30 kg S ha-1.All yield contributing characters viz., total achenes capitulum-1, filled achenes capitulum-1, head diameter and 1000-seed weight recorded significance with sulphur application at 60 kg ha-1 over 30 kg S ha-1 during both years of experimentation. However sterility percentage remained unaffected with different sulphur levels. Seed and stalk yield during 2009 and 2010 and pooled seed yield over two years recorded  with 60 kg S ha-1 was  significantly higher than 30 kg S ha-1. Both oil content and oil yield recorded significant improvement with increase in sulphur application from 30 to 60 kg S ha-1. FYM application at 10 and 20 t ha-1, at par with one another, recorded significant improvement in the plant height, leaf area index and dry matter production of sunflower at various crop growth periods except at 25 DAS over no FYM application during both years of experimentation. Seed yield over two years recorded with 10 and 20 t FYM ha-1 was at par but significantly higher than no FYM application. However, the stalk yield showed significant and consistent increase with increase in FYM rate up to 20 t ha-1. Oil content remained unaffected by different FYM levels during both years of experimentation. However, oil yield increased significantly and consistently with increase in FYM levels up to 20 t ha-1. Keywords: FYM,  Sulphur, Sunflower, Nitrogen, Yield

Study of Tensile Properties for Aluminum 6061 Reinforced With AISI 1060 Steel Machining Chips

The present study focuses on the tensile properties of Aluminum 6061 reinforced with AISI1060 Steel machining chips. Three different types of samples of aluminium 6061 reinforced with AISI 1060 steel machining chips were prepared using stir casting. The tensile test was conducted using universal test machine (UTM) for fabricated composites to study the tensile properties of aluminium 6061 reinforced with steel machining chips AISI 1060.The samples were prepared with different composition of AISI 1060 steel machining chip of 5%, 10% and 15% according to the weight fraction of parameter variable. Two casting processes were applied in this project namely stir casting and sand casting process. The stir casting was used to mix the two different metals to become a composite at temperature between 750℃ to 800℃ in a furnace while sand casting was used to fabricate the samples into ASTM-E8M standard for tensile testing. The results showed that the samples with higher reinforcement percentages of steel machining (15%) showed higher tensile stress and higher modulus value characteristic compared to other samples. The experiment proved that the reinforcement material has good mechanical properties compared to the pure material

The value of b0 images obtained from diffusion-weighted echo planar sequences for the detection of intracranial hemorrhage compared with GRE sequence

AbstractPurposeOur aim was to evaluate the clinical utility of b0EPI images obtained from diffusion sequence for the detection of the intracranial hemorrhagic lesions, especially acute intracerebral bleeds thereby shorten the scan time particularly in the critical acute cases of stroke.Materials and methodsAmong all consecutive MR brain studies performed in our department last year, we retrospectively selected those who followed the following criteria: (1) clinically suspected or radiographically confirmed acute infarction or hemorrhage. (2) MRI imaging including DWI and T2∗ images. Sensitivity of hemorrhage detection, conspicuity of lesions, and diagnostic certainty were compared between the b0EPI and GRE sequences.ResultsThere were 77 hemorrhagic lesions with a variety of pathogeneses in various locations. 76/77 (98.7%) of these lesions were hemorrhagic (hypointense) on the GRE sequences, whereas 61 (79.2%) were characterized as hemorrhagic on b0EPI images, and 16 (20.8%) were not detected. The overall difference in hemorrhage conspicuity/diagnostic certainty between GRE and b0EPI sequences was statistically significant (P<.05).Conclusionb0EPI sequence, although shorter in acquisition time, was inferior to GRE imaging in the detection of acute and chronic intracerebral hemorrhage

Literature review on energy efficiency standards and labels for household electrical appliances

This is a summarized previous works on energy efficiency standards and labels for household electrical appliances. It concerns mostly about international situation and other country experience about energy efficiency standard in residential sector. The possibilities of implementation of standards and labels for various household electrical appliances in Malaysia are also discussed. From the international review and other country experience shown that; there are many advantages for Malaysia to implement the standards and labels for household electrical appliances

Preventive Control of Powdery Mildew Disease of Mango

Oidium mangiferae Berthet was found to be associated With the powdery mildew disease of mango. The air- borne conidia are released from the old tissue harboring the dormant fungal hyphae under favorable weather conditions, which produce the disease. Proper forecasting of release of airborne innoculum significantly reduced the required number of sprays needed for chemical control. Spore traps were used to monitor the concentration of airborne conidia during the months of February, March and April 1996 and l997. Daily temperature and relative humidity were noted and the spore counts from the spore traps were correlated to the meteorological data. There was a positive trend between rising temperature, lowering relative humidity and number of spores in the air alter a low temperature, high humidity and cloudy spell of weather. The maximum spore occurrences were noted around 25°C and relative humidity of 40-60%. It took 5-8 days for the emergence of disease symptoms after the first detection of airborne conidia. Ten fungicides were tested on three mango varieties (Langra, Dashehari, and Anwar Retol). The preventive sprays at the stage of first detection of air born conidia were effective in controlling the disease. Optimal timing of two sprays of fungicide were sufficient to provide preventive control (>90%). The susceptibility of inflorescence varied with its developmental stage. Proper forecasting reduced the number of sprays from 7 to 2 or 3. There was no varietal difference in incidence of the disease or response to fungicide applications. During the course of this study, we identified seedling plants which consistently showed resistance to powdery mildew

Q7-branes and their coupling to IIB supergravity

We show how, by making use of a new basis of the IIB supergravity axion-dilaton coset, SL(2,R)/SO(2), 7-branes that belong to different conjugacy classes of the duality group SL(2,R) naturally couple to IIB supergravity with appropriate source terms characterized by an SL(2,R) charge matrix Q. The conjugacy classes are determined by the value of the determinant of Q. The (p,q) 7-branes are the branes in the conjugacy class detQ = 0. The 7-branes in the conjugacy class detQ > 0 are labelled by three numbers (p,q,r) which parameterize the matrix Q and will be called Q7-branes. We construct the full bosonic Wess--Zumino term for the Q7-branes. In order to realize a gauge invariant coupling of the Q7-brane to the gauge fields of IIB supergravity it is necessary to introduce an SL(2,R) doublet of two distinct Born--Infeld fields on the Q7-brane world-volume.Comment: 31 pages, Latex fil