Bioconversion of Macrocystis pyrifera to methane

Methane production by anaerobic digestion of kelp is a relatively new approach to augmenting the national gas supply. Digestion of the giant marine kelp Macrocystis pyrifera, investigated in a series of bench-scale experiments at the Institute of Gas Technology (IGT), is reported. Conducted with both untreated and chemically pretreated plants, the tests have evaluated the effects of major limits on bioconversion of kelp, including temperature, indigenous salt concentration, external nutrients, inocula source, loading, residence time, manner of mixing and frequency of feeding. A detailed chemical characterisation of the kelp samples is presented. Raw-kelp digestion was not limited by nitrogen or phosphorus. Temperature ranges of 35–40°C and 50–55°C were found to be optimum for mesophilic and thermophilic digestion of raw kelp. The mesophilic methane yield in the semicontinuous mode was about 4.5 SCF/lb (280.94 cm³ g^?1) of volatile solids (VS) added compared with a thermophilic methane yield of 2.4 SCF/lb (149.83 cm³ g^?1) of VS added. The mesophilic organisms could be acclimatised to a salt concentration that has a conductivity of 43 000 μmho cm^?1 without any deleterious effect. Thermophilic methanogens were more sensitive to high salt concentrations than the mesophilic organisms. Raw kelp had an estimated ultimate biodegradability of 80%. Mannitol and algin were the most biodegradable components.     

A third-generation SPARC V9 64-b microprocessor

This quad-issue processor achieves 1-GHz operation through improved dynamic circuit techniques in critical paths and a more extensive on-chip memory system which scales in both bandwidth and latency. Critical logic paths use domino, delayed clocked domino, and logic embedded in dynamic flip-flops for minimum delay. A 64-KB sum-addressed memory data cache combines the address offset add with the cache decode, allowing the average memory latency to scale by more than the clock ratio. Memory bandwidth is improved by using wave pipelined SRAM designs for on-chip caches and a write cache for store traffic. Memory power is controlled without increased latency by use of delayed-reset logic decoders. The chip operates at 1000 MHz and dissipates less than 80 W from a 1.6-V supply. It contains 23 million transistors (12 million in RAM cells) on a 244 mm² die     

A new family of semidynamic and dynamic flip-flops with embeddedlogic for high-performance processors

In an attempt to reduce the pipeline overhead, a new family of edge-triggered flip-flops has been developed. The flip-flops belong to a class of semidynamic and dynamic circuits that can interface to both static and dynamic circuits. The main features of the basic design are short latency, small clock load, small area, and a single-phase clock scheme. Furthermore, the flip-flop family has the capability of easily incorporating logic functions with a small delay penalty. This feature greatly reduces the pipeline overhead, since each flip-flop can be viewed as a special logic gate that serves as a synchronization element as well     

Psychological effects of immoral actions: The experimental evidence.

Considers the psychological consequences of immoral actions. Research on the effects on adults of breaking conventionally defined moral rules in controlled experiments is critically reviewed, including aggression, counterattitudinal advocacy, dishonesty, and interpersonal damage studies. It is established that immoral actions do affect the transgressor, with most of the impact related to the transgression. In experimental settings, major distortions do not result. Methodological issues with dependent measures are indicated, and patterns of research activity are discussed. Sense of responsibility for immoral actions and subjective definition of behavior as immoral may mediate effects. Current theories on reaction to transgression—cognitive dissonance, equity restoration, guilt, and negative-state relief—are evaluated. Limitations of existing experimentation, ways to increase its relevance to the full range of immoral actions, and ethical issues in the experimental study of immorality are indicated. (85 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An offset spline approximation for plane cubic splines

A plane cubic spline segment is given. We want to approximate its offset line by another cubic spline segment. Therefore we take the known curvatures and tangents at the end-points of the offset line and calculate the corresponding spline. Finally examples are given.     

Aging in the nematode Caenorhabditis elegans: major biological and environmental factors influencing life span

The free-living nematode Caenorhabditis elegans is an excellent experimental system for the study of aging. The present study identifies some of the major biological and environmental factors influencing life span as a prelude to more detailed genetic and biochemical analyses. Life span can be altered during any part of the life cycle by a change in either temperature or food concentration. Parental age and parental life span both have relatively small effects on progeny life span. The nematode accumulates fluorescent pigment resembling lipofuscin, and becomes less sensitive to ultra-violet radiation as it ages.     

Fast multiplication in VLSI using wave pipelining techniques

Wave pipelining is a design methodology that can increase the clock frequency of digital systems. Also known asmaximum-rate pipelining, it has long been considered a technique for approaching the physical speed limit of a digital circuit. Unlike conventional pipelining, wave pipelining does not require internal clocked elements to increase throughput. The synchronization of internal computations is achieved by balancing inherent RC delays of combinational logic elements, thus allowing circuits to be pipelined at a very fine-grain level. In this article, we describe the design of a 16×16 wave-pipelined multiplier using a 1.0 μm CMOS process. The multiplier is designed using a conventional static CMOS technology. Simulation results show a speedup of about 7× over a nonpipeline implementation.     

Pressing nozzles for high-speed steel teeming

Conclusions The Magnezit Combine has begun production of unfired pressed steel-teeming nozzles, with a channel diameter of 120 mm and height of 400 and 450 mm, made of magnesite paste.These nozzles have been put into service and adopted for high-speed top teeming of steel from a 330 ton ladle in the open-hearth shop of the KMW.Translated from Ogneupory, No. 1, pp. 23–26, January, 1979.     

Experience with producing ladle and blast furnace brick with a change in pressing rates

Conclusions A reduction in the pressing rate improves the factors of ladle and blast furnace refractories, since it affords the possibility of increasing the permissible upper limit for the pressing force, starting from the condition that there are no overpressing cracks.In order to obtain refractories with a low porosity it is desirable to prepare ladle and blast furnace brick with 5.0–5.5 pressings per minute with an average pressing rate of 9–11 mm/sec.Translated from Ogneupory, No.5, pp. 20–22, May, 1970.