On Peres' statement "opposite momenta lead to opposite directions", decaying systems and optical imaging

We re-examine Peres' statement ``opposite momenta lead to opposite directions''. It will be shown that Peres' statement is only valid in the large distance or large time limit. In the short distance or short time limit an additional deviation from perfect alignment occurs due to the uncertainty of the location of the source. This error contribution plays a major role in Popper's orginal experimental proposal. Peres' statement applies rather to the phenomenon of optical imaging, which was regarded by him as a verification of his statement. This is because this experiment can in a certain sense be seen as occurring in the large distance limit. We will also reconsider both experiments from the viewpoint of Bohmian mechanics. In Bohmian mechanics particles with exactly opposite momenta will move in opposite directions. In addition it will prove particularly usefull to use Bohmian mechanics because the Bohmian trajectories coincide with the conceptual trajectories drawn by Pittman et al. In this way Bohmian mechanics provides a theoretical basis for these conceptual trajectories.Comment: 20 pages, 3 figures, LaTex, to be published in Found. Phy

Impact of lens distrortions on strain measurements obtained with digital image correlation

The determination of strain fields based on displacements obtained via DIC at the micro-strain level is still a cumbersome task. In particular when high-strain gradients are involved, e.g. in composite materials with multidirectional fibre reinforcement, uncertainties in the experimental setup and errors in the derivation of the displacement fields can substantially hamper the strain identification process. In this contribution, the aim is to investigate the impact of lens distortions on strain measurements. To this purpose, we first perform pure rigid body motion experiments, revealing the importance of precise correction of lens distortions. Next, a uni-axial tensile test on a textile composite with spatially varying high strain gradients is performed, resulting in very accurate determined strains along the fibers of the materia

On the Consequences of Retaining the General Validity of Locality in Physical Theory

The empirical validity of the locality (LOC) principle of relativity is used to argue in favour of a local hidden variable theory (HVT) for individual quantum processes. It is shown that such a HVT may reproduce the statistical predictions of quantum mechanics (QM), provided the reproducibility of initial hidden variable states is limited. This means that in a HVT limits should be set to the validity of the notion of counterfactual definiteness (CFD). This is supported by the empirical evidence that past, present, and future are basically distinct. Our argumentation is contrasted with a recent one by Stapp resulting in the opposite conclusion, i.e. nonlocality or the existence of faster-than-light influences. We argue that Stapp's argumentation still depends in an implicit, but crucial, way on both the notions of hidden variables and of CFD. In addition, some implications of our results for the debate between Bohr and Einstein, Podolsky and Rosen are discussed.Comment: revtex, 11 page

Development of a test platform for anti-fouling coatings

Marine fouling, or the growth of marine organisms on fully or partly submerged structures, is an unwanted phenomenon in the marine industry. Bio fouling will increase the hydrodynamic drag of ships, causing an increased fuel consumption, promote the corrosion of the metallic structures and trigger undesired transport of invasive species (IMO and the environment 2009, 2009).The impact is economic as well as environmental. More fuel consumption is synonym for more CO2 and other detrimental emissions, corrosion entails coating and the introduction of toxic substances in the sea and air and the transport of hitch-hikers: non-indigenous species towards locations without natural enemies will harm the local delights of the marine environment.In 2001 the IMO adopted the "International Convention on the Control of Harmful Anti-Fouling Systems on Ships". This convention entered into force 17 September 2008 and prohibited the use of harmful organotins in anti-fouling paints used on ships. A mechanism was established to prevent the future use of other potential harmful substances in anti-fouling systems.The ban on organotins confronted the marine industry with a major challenge. TBT's (TriButylTin) have a negative impact on the marine biotope but till today no equally efficient, harmless, substance has been found. The search for an efficient, economic and ecological friendly novel anti-fouling paint is high on the agenda of IMO, governments, paint producers, ship owners and environmental organizations.All major marine coating producers bring to the market very similar products. Broadly speaking, the present hull anti-fouling systems focus on the following three generic types of AF-coating: firstly, hard coatings, usually biocide-free vinyl esters, reinforced with glass platelets. In actual fact this is not a real anti-fouling coating since fouling will appear over time but it resists mechanical cleaning, even with hard brushes, exceptionally well. Secondly, we have a whole range of soft/smooth paints, often based on silicones or fluoropolymers, rendering the hull surface so slippery that latching onto becomes difficult. Basically this type of coating cleans itself by means of the speed of the ship, the organisms with little adhesion will flush of easily. Finally, the most popular type of fouling protection, have a toxic additive incorporated in the topcoat. Predominantly these additives are copper based products reinforced with booster biocides. Three different techniques are being used to release these toxins in a more or less controlled way. The most primitive system, dating from the 50's, consist out of a soluble matrix, in general colophony mixed with copper, arsenic, zinc, mercury or iron oxides. A few years later, the binder became non-soluble, acrylic resins, vinyl resins or chlorinated rubber polymers were being used together with copper and zinc oxides with or without organometallic compounds. Presently mainly self-polishing copolymers are being used whereby biocides are leached under a controlled manner. While sailing the paint abrades and constantly a new layer of coating, mixed with zinc- or copper oxides emerges.Each of the above described AF-coatings has a very specific and limited field of application. Selecting the correct coating for a specific ship is far from self-evident. Important differences do exist within each coating type, dependent on the manufacturer. Unfortunately, no real objective means of comparing these products exists, neither on performance nor on ecological impact.The aim of this project is to establish an impartial test-protocol and build a platform for testing AF-coatings in a statically and dynamically manner. With knowledge of type, composition and performance of the anti-fouling paints tested we can advise the ship owners in an objective way and evaluate the ecological impact of a paint through a well-founded life cycle analysis

On the uniqueness of paths for spin-0 and spin-1 quantum mechanics

The uniqueness of the Bohmian particle interpretation of the Kemmer equation, which describes massive spin-0 and spin-1 particles, is discussed. Recently the same problem for spin-1/2 was dealt with by Holland. It appears that the uniqueness of boson paths can be enforced under well determined conditions. This in turn fixes the nonrelativistic particle equations of the nonrelativistic Schrodinger equation, which appear to correspond with the original definitions given by de Broglie and Bohm only in the spin-0 case. Similar to the spin-1/2 case, there appears an additional spin-dependent term in the guidance equation in the spin-1 case. We also discuss the ambiguity associated with the introduction of an electromagnetic coupling in the Kemmer theory. We argue that when the minimal coupling is correctly introduced, then the current constructed from the energy-momentum tensor is no longer conserved. Hence this current can not serve as a particle probability four-vector.Comment: 19 pages, no figures, LaTex, shortened version for Phys. Lett.

Ergogenic effect of pre-exercise chicken broth ingestion on a high-intensity cycling time-trial

Background: chicken meat extract is a popular functional food in Asia. It is rich in the bioactive compounds carnosine and anserine, two histidine-containing dipeptides (HCD). Studies suggest that acute pre-exercise ingestion of chicken extracts has important applications towards exercise performance and fatigue control, but the evidence is equivocal. This study aimed to evaluate the ergogenic potential of the pre-exercise ingestion of a homemade chicken broth (CB) vs a placebo soup on a short-lasting, high-intensity cycling exercise. Methods: fourteen men participated in this double-blind, placebo-controlled, crossover intervention study. Subjects ingested either CB, thereby receiving 46.4 mg/kg body weight of HCD, or a placebo soup (similar in taste without HCD) 40 min before an 8 min cycling time trial (TT) was performed. Venous blood samples were collected at arrival (fasted), before exercise and at 5 min recovery. Plasma HCD were measured with UPLC-MS/MS and glutathione (in red blood cells) was measured through HPLC. Capillary blood samples were collected at different timepoints before and after exercise. Results: a significant improvement (p = 0.033; 5.2%) of the 8 min TT mean power was observed after CB supplementation compared to placebo. Post-exercise plasma carnosine (p <  0.05) and anserine (p <  0.001) was significantly increased after CB supplementation and not following placebo. No significant effect of CB supplementation was observed either on blood glutathione levels, nor on capillary blood analysis. Conclusions: oral CB supplementation improved the 8 min TT performance albeit it did not affect the acid-base balance or oxidative status parameters. Further research should unravel the potential role and mechanisms of HCD, present in CB, in this ergogenic approach

In-situ local strain measurement in textile composites with embedded optical fibre sensors

To understand the local strains inside a textile composite, numerical simulations are typically done on the scale of one repetitive unit cell of the weaving pattern. Periodic boundary conditions are applied to the edges of the unit cell and different load cases can then be applied to the unit cell of the textile composite. Most often, the periodic boundary conditions are applied on all faces of the unit cell, which implies the assumption that the material is repeating itself over an infinite distance in all three orthogonal directions. This assumption is more or less valid for the textile composite material in the midplane of thick laminates, where it is constrained by neighbouring material in all three directions. It is very difficult to validate such simulations, because local strain measurements inside a textile composite have rarely been done, and the interpretation is not straightforward. This paper shows the successful use of embedded optical fibre sensors to measure the local strains inside a satin weave carbon/PPS composite (typically used in aerospace applications). The length of the Bragg grating inside the optical fibre sensor has been chosen such that it is longer than the length of one unit cell of the satin weave architecture (7.4 mm). The read-outs of the optical fibre sensor give the minimum and maximum local strains that occur along the length of the Bragg grating

FLH Type 5 Caused by a Novel Mutation in STXBP2 Gene: An Unusual Cause of Failure to Thrive and Diarrhea in Infancy

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