Sprinklered office fire tests

This paper presents data relating to the performance of sprinklers and detectors in real office fire situations. For sprinklers, these data are additional to that associated with the standardized testing used to determine the design delivery density and pressure requirements for various occupancy situations, and provide a useful insight into the effect of sprinklers on developing fires with various office situations. The data given in this paper include the times for activation of various types of sprinkler heads (normal and fast response), the efficacy of the systems as far as extinguishment is concerned, estimates of the maximum size of the fires prior to commencement of extinguishment and associated air temperatures at various locations within the office enclosures. Copyright © 2008 John Wiley & Sons, Ltd.     

Barium aluminate hydrates. IV. α-BaO.Al2O3.4H2O

α-BaO.Al₂O₃.4H₂O has been synthesised and studied by infrared, X-ray and thermal analytical techniques. The compound of approximate formula BaO.Al₂O₃.0.5H₂O, described in Part III, forms as a dehydration product, and appears to be identical with the compound β-BAH₂ described by other workers. A possible explanation for the discrepancy in water content is discussed.     

Optimized unequal error protection of embedded video bitstream using adaptive-hierarchical QAM

In this paper, a reliable video communication system using adaptive Hierarchical QAM (HQAM) is designed to provide optimized unequal error protection (UEP) to embedded video bitstreams. Based on the relative importance of bits, video bitstream is partitioned into two priorities, namely High Priority (HP) and Low Priority (LP) substreams. Then, the optimal value of modulation (or hierarchical) parameter (α) of HQAM, which controls the relative error protection of these substreams, is selected from a pre-designed look-up table. The proposed system adapts itself by adapting the optimal α according to the varying channel condition, without changing the modulation level. This is in contrast to conventional WiMAX and LTE systems, in which dynamic switching among multiple modulations is used to adapt the varying channel conditions. This paper proposes HQAM with adaptive α as an alternative to the multiple modulation schemes. Moreover, for fixed average transmission power, receiver demodulates symbols without the knowledge of α. In order to further improve the video quality and to reduce the effects of erroneously received LP bits, the proposed system uses another level of adaptation, in which received LP bits are adaptively considered or discarded, before decoding the video, depending on the channel conditions (or optimized α). Simulation results show that proposed system can achieve significant improvement in the video quality compared to QAM based EEP scheme and non-adaptive HQAM.     

DFT-based no-reference quality assessment of blurred images

Multimedia Tools and Applications - In this paper, blind image quality assessment (IQA) of Gaussian blurred images based on Discrete Fourier Transform (DFT) is proposed. The proposed work is based...     

A noise constrained least mean fourth (NCLMF) adaptive algorithm

The learning speed of an adaptive algorithm can be improved by properly constraining the cost function of the adaptive algorithm. In this work, a noise-constrained least mean fourth (NCLMF) adaptive algorithm is proposed. The NCLMF algorithm is obtained by constraining the cost function of the standard LMF algorithm to the fourth-order moment of the additive noise. The NCLMF algorithm can be seen as a variable step-size LMF algorithm. The main aim of this work is to derive the NCLMF adaptive algorithm, analyze its convergence behavior, and assess its performance in different noise environments. Furthermore, the analysis of the proposed NCLMF algorithm is carried out using the concept of energy conservation. Finally, a number of simulation results are carried out to corroborate the theoretical findings, and as expected, improved performance is obtained through the use of this technique over the traditional LMF algorithm.     

Co-processing of cefuroxime axetil by spray drying technique for improving compressibility and flow property

The aim of the present investigation was to improve the compressibility and flow property of cefuroxime axetil by co-processing it with mannitol and chitosan chlorhydrate using spray drying method. 3² full factorial design, having inlet air temperature and mannitol: chitosan chlorhydrate ratio as independent variables was used for the optimization. Statistical analysis of obtained results revealed that both independent variables had significant effect on response variables (p value?<?.05). Evaluation of dependent variables suggested, excellent to good flow properties (angle of repose, Carr's index, and Hausner's ratio) for all prepared batches. Desirability function was used for the selection of the optimized batch which was evaluated for Kawakita’s equation, Heckel’s plot to assess compression behavior of co-processed product under applied pressure. Result of this analysis revealed that the optimized batch product had better compressibility than physical mixture. The tablets prepared by directly compressing spray-dried product, exhibited excellent tensile strength acceptable friability (<1%) and similar release profile when compared with marketed formulation (Similarity factor 89.24 and dissimilarity factor 1.79). So the results of the present investigation concluded that cefuroxime axetil was successfully co-processed with above mentioned excipients by using spray drying method to make it directly compressible.