Triple-ball connector for optical fibres

A demountable fibre connector which uses two interlocking sets of three balls to locate the fibres accurately and simultaneously to align the two parts of the connector has been constructed. The samples tested so far, using Corning stepindex fibre, have shown average losses of less than 0.2 dB with index matching and less than 0.5 dB without. The connector is cheap, easy to make and could be assembled in the field.     

The interaction between cutaneous and spinal therman inputs in the control of oxygen consumption in the rat

1. The effect of thermal stimulation of the spinal cord on the rate of oxygen consumption was studied in five unanaesthetized rats during exposure to various ambient temperatures. 2. In a warm environment, cooling the spinal cord had no effect on the rate of oxygen consumption but in thermoneutral and cold environments the rate of oxygen consumption increased proportionally to the intensity of spinal cooling. Heating the spinal cord decreased the level of oxygen consumption and, if intense enough, suppressed the thermoregulatory increase in metabolic rate. 3. It is concluded that, in the control of oxygen consumption in the rat, the afferent signals from thermal sensors in the spinal cord and skin are added.     

Automatically Proving Termination and Memory Safety for Programs with Pointer Arithmetic

While automated verification of imperative programs has been studied intensively, proving termination of programs with explicit pointer arithmetic fully automatically was still an open problem. To close this gap, we introduce a novel abstract domain that can track allocated memory in detail. We use it to automatically construct a symbolic execution graph that over-approximates all possible runs of a program and that can be used to prove memory safety. This graph is then transformed into an integer transition system, whose termination can be proved by standard techniques. We implemented this approach in the automated termination prover AProVE and demonstrate its capability of analyzing C programs with pointer arithmetic that existing tools cannot handle.     

轮胎工业用无锌橡胶加工助剂

自轮胎工业诞生以来，橡胶就一直是它的原材料。这段历史使轮胎工业积累了宝贵的胶料加工经验。但是，尽管有这些经验，如何有效地加工胶料仍是每个轮胎公司生产部门面临的挑战。     

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Biologically inspired, fibrillar dry adhesives continue to attract much attention as they are instrumental for emerging applications and technologies. To date, the adhesion of micropatterned gecko‐inspired surfaces has predominantly been tested on stiff, smooth substrates. However, all natural and almost all artificial surfaces have roughnesses on one or more different length scales. In the present approach, micropillar‐patterned PDMS surfaces with superior adhesion to glass substrates with different roughnesses are designed and analyzed. The results reveal for the first time adhesive and nonadhesive states depending on the micropillar geometry relative to the surface roughness profile. The data obtained further demonstrate that, in the adhesive regime, fibrillar gecko‐inspired adhesive structures can be used with advantage on rough surfaces; this finding may open up new applications in the fields of robotics, biomedicine, and space exploration.     

Absorption of N-phenylpropenoyl-L-amino acids in healthy humans by oral administration of cocoa (Theobroma cacao)

Besides flavan-3-ols, a family of N-phenylpropenoyl-L-amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC-MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid (6) and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC-MS/MS before and after beta-glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O-glucuronides nor their O-sulfates. In order to screen for caffeic acid O-glucuronides as potential NPA metabolites, urine samples were screened by means of LC-MS/MS for caffeic acid 3-O-beta-D-glucuronide and 4-O-beta-D-glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O-methylation or reduction of the N-phenylpropenoyl moiety in NPAs.     

Evolving Synergy: OCEAN Currents,Current OCEANs and Why Networks Must Displace Themselves

Founded in the early 1990s, OCEAN was one of the first collaborative geographically distributed practices to realise the potential of telecommunication and digital design technologies. Here Michael Hensel recounts the various mutations and fluid transformations of the experimental groupings that came to form OCEAN net. Accordingly, Hensel's account is more akin to a band biography than a staid sociology of a professional office. Moreover, he explores how the molecular model of distributed authorship presents difficulties, either by confounding external expectations of a singular identity or signature behind the various design processes, or internally as a stable whole of identities attempting to re-emerge and fix its collaborative mixings into a rigid hierarchy. As OCEAN's biography attests, true collaboration is inherently flat, distributed and transformative, situating architecture as more than just a service profession and transforming it into an intensive practice of living. Collective intelligence in these terms is embedded in the distributed evolutionary processes of the practice as a design project in itself. Copyright © 2006 John Wiley & Sons, Ltd.     

Evidence from spectral emissometry for conduction intraband transitions in the intrinsic regime for silicon

From emissometry measurements in lightly doped Si at elevated temperatures, we have observed an anomalous absorption band in the wavelength range of 1–5 μm. The wavelength at which the band peaks, λ≈2.3 μm, shows a negligible dependence on temperature while the peak intensity increases with temperature presumably as a result of the increasing intrinsic carrier concentration. Spitzer and Fan reported a similar absorption band in direct absorption measurements at room temperature for n-type Si with extrinsic electron concentrations of 10¹⁴ to 10¹⁹cm⁻³. No such structure was found in extrinsic p-type Si. Spitzer and Fan were unable to identify the mechanism for this anomalous absorption. In both the experiments, this absorption of free electrons is due to intraband transitions in the conduction band from the Δ₁ conduction band edge across an energy gap of E ∼ 0.5 eV to a higher lying Δ₂′ conduction band.