Analytic model for turn off in the silicon-on-insulator LIGBT

Lateral insulated gate bipolar transistors (LIGBTs) in silicon-on-insulator (SOI) show a unique turn off characteristic when compared to junction-isolated RESURF LIGBTs or vertical IGBTs. The turn off characteristic shows an extended `terrace' where, after the initial fast transient characteristic of IGBTs due to the loss of the electron current, the current stays almost at the same value for an extended period of time, before suddenly dropping to zero. In this paper, we show that this terrace arises because there is a value of LIGBT current during switch off where the rate of expansion of the depletion region with respect to the anode current is infinite. Once this level of anode current is approached, the depletion region starts to expand very rapidly, and is only stopped when it reaches the n-type buffer layer surrounding the anode. Once this happens, the current rapidly drops to zero. A quasi-static analytic model is derived to explain this behaviour. The analytically modelled turn off characteristic agrees well with that found by numerical simulation.

Studies on the preparation of fish silage. 1. Effect of quality of raw material and type of acid

An experiment was undertaken in which silver bellies (Leiognathus splendens) of different quality were used to produce silages using different concentrations of hydrochloric acid and formic acid. The quality and storage life of the various preparations are reported. Silages which keep for at least 30 days can be produced from silver belly held for 3 or 12 hours at 28°C by: 1) reducing the pH by addition of hydrochloric acid; 2) adding 0.5% formic acid and reducing the pH to 3.5 with hydrochloric acid; or 3) adding 2.5% formic acid.

Molecular cloning, characterization and localization of chicken type II procollagen gene

Chicken type II procollagen (ccol2a1) has become as an important oral tolerance protein for effective treatment of rheumatoid arthritis. However, its molecular identity remains unclear. Here, we reported the full-length cDNA and nearly complete genomic DN

Functional characterization of the human-specific (type II) form of kallikrein 8, a gene involved in learning and memory

Kallikrein 8 (KLK8) is a serine protease functioning in the central nervous system, and essential in many aspects of neuronal activities. Sequence comparison and gene expression analysis among diverse primate species identified a human-specific splice for

Adaptive control of combustion instabilities for unknown sign of the high frequency gain

A type of adaptive, closed-loop controllers known as self-tuning regulators present a robust method of eliminating thermoacoustic oscillations in modern gas turbines. These controllers are able to adapt to changes in operating conditions, and require very little pre-characterisation of the system. One piece of information that is required, however, is the sign of the system's high frequency gain (or its 'instantaneous gain'). This poses a problem: combustion systems are infinite-dimensional, and so this information is never known a priori. A possible solution is to use a Nussbaum gain, which guarantees closed-loop stability without knowledge of the sign of the high frequency gain. Despite the theory for such a controller having been developed in the 1980s, it has never, to the authors' knowledge, been demonstrated experimentally. In this paper, a Nussbaum gain is used to stabilise thermoacoustic instability in a Rijke tube. The sign of the high frequency gain of the system is not required, and the controller is robust to large changes in operating conditions - demonstrated by varying the length of the Rijke tube with time. Copyright © 2008 by Simon J. Illingworth & Aimee S. Morgans.

Cloning of cDNAs encoding C-type lectins from Elapidae snakes Bungarus fasciatus and Bungarus multicinctus

A number of C-type lectins with various biological activities have been purified and characterized from Viperidae snake venoms. In contrast, only a few reports could be found in literature concerning the C-type lectins in Elapidae snake venoms. Based on t

Stejnulxin, a novel snake C-type lectin-like protein from Trimeresurus stejnegeri venom is a potent platelet agonist acting specifically via GPVl

Stejnulxin, a novel snake C-type lectin-like protein with potent platelet activating activity, was purified and characterized from Trimeresurus stejnegeri venom. Under non-reducing conditions, it migrated on a SDS-polyacrylamide gel with an apparent molecular mass of 120 kDa. On reduction, it separated into three polypeptide subunits with apparent molecular masses of 16 kDa (alpha), 20 kDa (beta(1)) and 22 kDa (beta(2)), respectively. The complete amino acid sequences of its subunits were deduced from cloned cDNAs. The N-terminal sequencing and cDNA cloning indicated that beta(1) and beta(2) subunits of stejnulxin have identical amino acid sequences and each contains two N-glycosylation sites. Accordingly, the molecular mass difference between 1 and 2 is caused by glycosylation heterogenity. The subunit amino acid sequences of stejnulxin are similar to those of convulxin, with sequence identities of 52.6% and 66.4% for the U. and beta, respectively. Stejnulxin induced human platelet aggregation in a dose-dependent manner. Antibodies against UNA inhibited the aggregation response to stejnulxin, indicating that activation of alpha(IIb)beta(3) and binding of fibrinogen are involved in stejnulxin-induced platelet aggregation. Antibodies against GPIbalpha or alpha(2)beta(1) as well as echicetin or rhodocetin had no significant effect on stejnulxin-induced platelet aggregation. However, platelet activation induced by stejnulxin was blocked by anti-GPVI antibodies. In addition, stejnulxin induced a tyrosine phosphorylation profile in platelets that resembled that produced by convulxin. Biotinylated stejnulxin bound specifically to platelet membrane GPVI.

TMVA, a snake C-type lectin-like protein from Trimeresurus mucrosquamatus venom, activates platelet via GPIb

TMVA is a C-type lectin-like protein with potent platelet activating activity from Trimeresurus mucrosquamatus venom. In the absence of von Willebrand factor (vWF), TMVA dose-dependently induced aggregation of washed platelets. Anti-GP Ib monoclonal antib

Incidence of ulcer type of disease in wild fishes of Bangladesh

Disease occurred in wild fish species investigated in different water bodies like canals, ditches, beel, haor, flood plain in 17 districts of Dhaka division. Haemorrhagic lesions were observed on the body surface of affected fishes. Incidence of the disease in the investigated water bodies ranged from 0 to 100%. In total 19 fish species were found to be affected and prevalence of infection ranged from 0.0 to 100.0%. Channa punctatus and Puntius ticto were severely affected in all locations. Percentage of infection in these fishes ranged from 0.0 to 100.0. The highest infection was observed in Netrokona, Kishoreganj, and Mymensingh districts. Bacterial genera isolated from the lesions of these affected fishes were Aeromonas, Pseudomonas, Flavobacterium, Micrococcus, and Staphylococcus. Among these isolates Aeromonas was the dominant. Abundance of Aeromonas in the lesions among the investigated bacteria ranged from 75 to 90%. Five identified Aero monas lrydrophila were examined for their pathogenicity and were able to infect the experimental fish, silver barb (Puntius gonionotus). The pathogen Aeromonas hydrophila was thus considered to have an association with the outbreak of ulcer type of disease in the investigated fish species.