Built-in self-test of a CMOS ALU

A technique is proposed for implementing BIST (built-in self-test) in a CMOS arithmetic and logic unit (ALU). The approach covers single stuck-open faults and all functional faults that do not induce memory effects. The specific fault set covered by the test includes: (1) all single stuck-open faults on n and p transistors anywhere in the ALU (F1 faults); and (2) all functional faults that affect any single-bit slice of the (F2 faults), a functional fault being any fault that changes one combinational function into another. Functional faults in multiple slices are also detectable, as long as they do not generate identical responses in all even-numbered or odd-numbered ALU slices. With common techniques for test vector generation and response-verification, this BIST implementation provides higher fault coverage with only a small increase in surface area     

Multikilojoule inductive modulator with solid-state openingswitches

A four-stage inductive storage XRAM (inverse MARX) circuit was used to amplify current and power. By means of switching action, individual inductors are charged in series and discharged in parallel to the load. A microprocessor controls the timing of the switches, which results in a predetermined load current waveform. The use of present asymmetric GTOs at much higher currents than rated allowed the amplification and shaping of a 2.5 kA charging current to 9.6 kA at the load. An energy of 25 kJ was transferred to the load, yielding 84% efficiency. The losses were mainly due to the winding resistance of the inductors. With the best-performance commercially available GTOs, this circuit may deliver over 100 kJ with an energy density of 1.6 kJ/kg. Simulation and experimental results are presented     

Spoilage of fruit juice by bacilli: isolation and characterization of the spoiling microorganisms

A Bacillus-strain was isolated from spoiled apple juice. This strain was acidophilic with a growth range between pH 2.5 and 5.5. Lipid analysis demonstrated the occurrence of omega-cyclohexane fatty acids and hopanoids. As these cell constituents have among bacilli been found only in Bacillus acidocaldarius strains, our isolated microorganism seems to be related to this species. Our organism could be a threat to fruit juices during storage at elevated temperatures (greater than or equal to 26 degrees C) because its spores were able to survive pasteurization conditions.     

Abh?ngigkeit der thermischen Abt?tung von Mikroorganismen vom pH-Wert der Medien

Zusammenfassung Die feuchtthermische Abtötung von Hefezellen und Schimmelpilzkonidien ist bei niedrigen Erhitzungstemperaturen (t 55 °C) stark pH-abhängig. Der EinfluB des pH-Wertes auf die thermische Abtötung von Mikroorganismen nimmt mit zunehmender Temperatur generell ab und dürfte beihitzeempfindlichen vegetativen Arten bereits bei Pasteurisationstemperaturen über 65 °C weitgehend zu vernachlässigen sein. Bei vorgegebenem pH-Wert beeinflußt die chemische Zusammensetzung der organischen Säure die Hitzeempfindlichkeit der Mikroorganismen erheblich. Citronensäure erschwert die thermische Abtötung von Hefen, während Essigsäure die Abtötungsrate stark erhöht. Im alkalischen Bereich werden Hefen besonders rasch durch Hitze abgetötet. Maxima der Hitzebeständigkeit waren bei Hefen und Schimmelpilzkonidien vornehmlich im schwach sauren Milieu zu beobachten.

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Dependence of thermal inactivation of microorganisms on the pH-value of mediaI. Yeasts and moulds

Summary Thermal inactivation of yeast cells and mould conidia is strongly pH-dependent at temperatures below 55 °C (131 °F). The influence of pH on thermal inactivation of microorganisms generally decreases with increasing temperatures and with heat-sensitive vegetative cells may be neglected above 65 °C (149 °F). At a given pH-value heat inactivation rates are dependent on the composition of the buffer systems used. Some organic acids like citric acid protect yeasts from thermal inactivation whereas others (like acetic acid) enhance heat inactivation. In the alkaline region yeast cells are rapidly killed by heat even at rather low temperatures. Maximal thermal resistance is shown by yeasts and mould conidia primarily in a weakly acidic medium.

     

Isolation and characterization of a 'quinone-trapping' substance from a crude Carica papaya protein preparation

The oxidation of different phenols [4-methylcatechol, chlorogenic acid, (−)-epicatechin and (+)-catechin] by endive polyphenoloxidase (PPO) was investigated in the presence of an extract from Carica papaya . The occurrence of cysteine and another 'quinone-trapping' substance in the extract was demonstrated. The unknown substance was purified, as a 4-methylcatechol conjugate form, by a combination of Bio-gel Pz chromatography and semipreparative high-performance liquid chromatography (HPLC). Use of liquid chromatography/tandem mass spectroscopy (LC–MS/MS) equipment and an amino acid analyser allowed us to identify this agent as a dipeptide cysteine-glutamic acid, commercially available as γ-Glu-Cys. γ-Glu-Cys formed one adduct compound with 4-methylcatechol and chlorogenic acid, and two with the flavan-3-ols. The thiol adducts were not substrates for endive PPO but, in the case of the 4-methylcatechol conjugate, they acted as competitive PPO inhibitors.     

Chemical cross-linking and H/D exchange for fast refinement of protein crystal structure

A combination of chemical cross-linking and hydrogen-deuterium exchange coupled to high resolution mass spectrometry was used to describe structural differences of NKR-P1A receptor. The loop region extended from the compact core in the crystal structure was found to be closely attached to the protein core in solution. Our approach has potential to refine protein structures in solution within a few days and has very low sample consumption.     

Improving Termination of MDG-Based Abstract State Enumeration via Term Schematization

The MDG approach for hardware verification was recently proposed to overcome some limitations of traditional ROBDD-based methods of automated verification. One of its weakness, however, is that it may suffer from the non termination of the state enumeration procedure. In this paper, we exploit an idea recently proposed of using term schematization to address this problem. We propose a strategy to direct the introduction of schematized terms in the state enumeration procedure. We show that for certain cases of non termination, it significantly improves over the previously known approaches.     

Distribution of 3H-labeled acetyl-HEMA monomer in rats

We have studied the activity of substances (superoxide dismutase [SOD], catalase [Cat], malonaldehyde, xanthine oxidase [XO], nitric oxide [NOx]) participating in oxidative stress. Seminal plasma samples of 147 ejaculates obtained from normal and from infertile males were examined. Activities of SOD, Cat, and XO were measured chemiluminometrically while malonaldehydes and NOx were measured by spectrophotometer in seminal plasma samples. Ejaculates were previously characterized according to World Health Organization andrological criteria (sperm number, motility, and morphology). Procedures were performed in a university laboratory. Statistically significant changes (in comparison to normozoospermic samples) were noted in activities of SOD, XO, and malonaldehyde levels. The SOD activity exceeded values obtained for normozoospermic samples only in oligozoospermia. Otherwise low SOD levels in analyzed infertile subgroups inversely related to elevated malonaldehydes. Because diminished activity of SOD in seminal plasma was associated with increased levels of malonaldehydes and XO, we could postulate some significance of these monitored substances in evaluation of the cause of male infertility.