Design, development and testing of a large-size solar cooker for animal feed

A large-size solar cooker for animal feed has been designed, developed and tested. The cooker employs locally available materials of low cost, e.g. pearl-millet husk and horse excreata. The commercial materials required for its fabrication are plain glass, mild steel angle and sheet, wood and aluminium sheet cooking utensils. The solar cooker is capable of boiling 10 kg of animal feed, sufficient for five cattle per day. The efficiency of the solar cooker is 21·8%. The cost of the cooker is only Rs 1200, which can be recovered in 0·45-1·36 years depending upon the fuel it replaces. The short payback periods suggest that the use of the solar cooker is economic. The use of the cooker will save a lot of firewood, cowdung cake and agricultural waste which are presently used for the boiling of animal feed.     

A study of opportunism for multiple-antenna systems

Recently proposed opportunistic beamforming exploits the multiuser diversity to reduce the feedback by not requiring the precoding information used for closed-loop schemes to be known at the transmitter. Opportunism could also be beneficially employed for other multiple-antenna transmission techniques like cophasing and antenna selection. For opportunistic beamforming and antenna selection, we give closed-form expressions for throughput that closely approximate the performance of these schemes with a Proportionally Fair scheduler (PFS) at low signal-to-noise ratios (SNRs). For large number of transmit antennas, opportunistic cophasing has similar performance as opportunistic beamforming. Asymptotic dependence of the required number of users to achieve the gains of opportunism on the number of transmit antennas is exponential for opportunistic beamforming (and cophasing for large numbers of transmit antennas), and at best linear for opportunistic antenna selection. For multiple-antenna receivers, we additionally examine an opportunistic multiple-input multiple-output (MIMO) scheme that transmits multiple data streams simultaneously to the same user.     

RHEOLOGICAL EVALUATION OF MOZZARELLA CHEESE BY UNIAXIAL HORIZONTAL EXTENSION

Rheological properties of low-moisture part-skim Mozarella cheese were evaluated as a function of storage time, test temperature, and deformation rate by uniaxial extension in a horizontal plane. Proteolysis of Mozzarella cheese caused marked decreases in the tensile strength and the deformability modulus, but not in the fracture strain. As the temperature increased from 10 to 40C, the fracture strain increased more than five-fold. The strength and the deformability modulus decreased about 60 and 85%, respectively, as the cheese temperature increased from 10 to 30C. The fracture strain of the cheese did not exhibit a clear trend with the deformation rate in the range of 50–500 mm/min. However, its strength and deformability modulus increased with the increasing deformation rate.     

Synthesis,characterisation and use of 2-tetradecylcyclobutanone together with other cyclobutanones as markers for irradiated liquid whole egg

The synthesis and characterisation of 2-tetradecylcyclobutanone (TCB) is described. Both 2-dodecykyclobutanone and TCB were shown to be present in liquid whole egg irradiated at doses of 2.5 and 10.0 kGy. These compounds were absent from the unirradiated pasteurised samples. Using gas chromatography and infrared spectroscopy, there was also evidence for the presence in irradiated egg of 2-tetradeccnyl- and 2-tetradecadienylyclobutanone which are formed from oleic and linoleic acids, respectively. Authentic standards for these unsaturated cyclobutanones were not available commercially but the presence of 2-tetra-decenylcyclobutanone was substantiated by hydrogenating the egg extracts so converting this unsaturated cyclobutanone to TCB. Saturated and unsaturated cyclobutanones appear to be specific products of irradiation and are potential markers for detection of irradiated liquid egg and probably other fat-containing foods.     

On the uniformly minimum variance unbiased estimator of availability with type I censored data

This paper develops the uniformly minimum variance unbiased estimator of the pointwise availability with type I censored data. The maximum likelihood estimator has also been highlighted.     

MOSFET substrate current model for circuit simulation

A simple, accurate MOSFET substrate current model suitable for a circuit simulator is presented. The effect of substrate bias on substrate current is modeled without introducing additional parameters. The accuracy of this model is demonstrated by its ability to fit the experimental data for both standard and LDD devices with average errors of less than 6%. The new model is compared with the substrate current models reported in the literature. In addition, the temperature dependence of the substrate current in the range of 0-120°C is also modeled. The new model has been implemented in a circuit-level hot-electron reliability simulator, and the results obtained from simulation of an inverter circuit are presented     

Two new canonic single-CFOA oscillators with single resistor controls

Although a number of single current feedback op-amps (CFOA)-based single-resistance-controlled oscillators (SRCO) have appeared in earlier literature, only six of them are canonic (i.e., requiring only two capacitors and only three resistors). The object of this brief is to add to this list two new canonic single-CFOA-based SRCO configurations. An evaluation of these two new circuits has been carried out and their workability of has been confirmed by experimental results based upon AD844 CFOAs.     

Effect of nanoimprinted surface relief on Si and Ge nucleation and ordering

Surface relief formed by nanoimprinting and etching into a thermally grown SiO₂ layer on Si was used to position the initial nuclei formed by chemically vapor deposited Si and Ge. By controlling the deposition conditions, the surface diffusion length was adjusted to be comparable to or larger than the spacing between features, thus favoring nucleation adjacent to steps, rather than random nucleation. Random nucleation was further suppressed by a two-stage deposition process. Ge nucleation on oxide by chemical vapor deposition was enhanced by coating the oxide surface with an organic self-assembled monolayer (SAM) and by the nanoimprinted surface relief. The nanoimprinted surface relief also provides long-range order in the SAM.     

Effect of linker used in D–A–π–A metal free dyes with different π-spacers for dye sensitized solar cells

Two novel D–A–π–A metal free dyes with triphenylamine as donor, dithiophene-diketo-pyrrolo-pyrrole as acceptor unit, thiophene and phenyl π-conjugated bridges and a cyanoacetic acid as electron acceptor (TDPP1 and TDPP2 were denoted for thiophene and phenyl π-conjugated bridge, respectively) have been designed and used as sensitizers for DSSCs. Incorporation of dithiophene-diketo-pyrrolo-pyrrole, reduces the band gap significantly. The influence of π-conjugated bridge on optical and electrochemical properties were investigated. Results demonstrated that the absorption band of TDPP with thiophene π-conjugated bridge has red shifted due to the enhancement of electron donating ability of π-conjugated bridge. The DSSC based on TDPP1 shows prominent power conversion efficiency about 4.81%, which is higher that for TDPP2 (3.42%). The electrochemical impedance spectroscopy analysis reveal that the charge recombination resistance at the TiO₂/dye/electrolyte interface for the DSSC based on TDPP1 is higher than that for TDPP2, which improves both J_sc and V_oc. The PCE of the DSSC based on TDPP1 is further improved up to 6.34%, when deoxycholic acid (DCA) was employed as coadsorbant.     

Fractional Laplace transform

A new definition of the fractional Laplace transform is proposed as a special case of the complex linear canonical transform. The proposed fractional Laplace transform reduces to the conventional bilateral Laplace transform and the fractional Fourier transform exactly and hence is better suited for the definition of the fractional Laplace transform as compared to the other definitions proposed earlier in the literature. The advantage of the proposed transform as compared to the conventional Laplace transform lies in providing a free parameter which can be effectively exploited in the filtering and signal separation problems.