Applications of Walsh functions in communications

Communication theory was founded on the system of sine-cosine functions. A more general theory has become known more recently; it replaces the sine-cosine functions by other systems of orthogonal functions, and the concept of frequency by that of sequency. Of these systems, the Walsh functions are of great practical interest since they lead to equipment that is easily implemented by semiconductor technology. Filters, multiplexing equipment, and a voice analyzer/synthesizer have been built successfully for Walsh functions. Some interesting applications of electromagnetic Walsh waves have been found theoretically.     

Verbesserte Methode zur Lysinoalaninbestimmung in Lebensmitteln

Zusammenfassung Es wird eine gegenüber anderen Verfahren in Auftrennungskapazität und Schnelligkeit verbesserte Methode zur Bestimmung von Lysinoalanin (LAL) beschrieben, die universell zur Untersuchung von Lebensmitteln anwendbar ist. Nach entsprechender Probenaufbereitung und Freisetzung des Lysinolanins durch salzsaure Hydrolyse wird das Eiweißhydrolysat mit Natronlauge/Natriumcitratpuffer direkt neutralisiert. Die Auftrennung erfolgt im Aminosäureanalysator durch ein basisches Kurzzeitprogramm (Citrat-Elutionspuffer pH 4,50/0,61 nNa⁺, 60 °C, LAL-Elutionszeit 55 min) mit Ninhydrinnachweis. Damit kann LAL in fast allen Lebensmitteln ohne nennenswerte Interferenzprobleme bestimmt werden; auch die in manchen Lebensmitteln, vor allem in erhitzten Milchprodukten, üblichen relativ hohen Aminozucker-, Fructoselysin- und Lactuloselysin-Konzentrationen stören die Bestimmung des LAL nicht. Hinsichtlich LAL-Absorption an Huminstoffe, Wiederfindung und Nachweisgrenze ist zwischen kohlenhydratreichen Lebensmitteln und reinen Proteinkomponenten zu unterscheiden. Je nach Probenmatrix ergibt sich eine Nachweisgrenze von 10–40 ppm im Eiweiß. Genaue Bestimmungen können bis zu 80 ppm LAL im Eiweiß durchgeführt werden, die minimale nachweisbare LAL-Menge beträgt bei höchster Empfindlichkeit 10 ng LAL.

---

Improved method for determination of lysinoalanine in food

Summary A faster method for the determination of lysinoalanine (LAL) was developed which is universally applicable to all kinds of food products and shows a better ability to separate LAL from interference substances. After appropriate sample preparation and liberation of protein bound LAL by acid hydrolysis the protein hydrolysate is directly neutralized with sodium hydroxide/sodium-citrate-solution. LAL is separated by means of an automatic amino acid analyzer with a special short time program for basic amino acids (sodium citrate buffer pH 4.50/0.61 nNa⁺, 60°C, LAL-elution after 55 min) and detected colorimetrically with ninhydrin. There are no interference problems with high concentrations of amino sugars, fructoselysine and lactuloselysine which occur to a considerable degree particularly in heated milk products. As for LAL-absorption on humin substances, recovery and detection limit, there is a difference between pure protein compounds and samples rich in carbohydrates. Depending on the type of sample matrix detection of 10–40 ppm LAL in protein is possible. Exact quantitative determination is limited to 80 ppm LAL in protein. The lowest amount of LAL that can be detected is 10 ng.

---

---

Herrn Prof. Dr. Ing. Dr. h.c. mult. Helmut Zahn in Verehrung zum 65. Geburtstag gewidmet     

Empfindliche Bestimmung von Lysinoalanin und 2,3-Diaminopropionsäure durch fluorimetrische Detektion mit ortho-Phthaldialdehyd

European Food Research and Technology - A highly sensitive fluorometric method for simultaneous determination of lysinoalanine (LAL) anddl-2,3-diaminopropionic acid (DAP) was developed. After acid...     

Routing of straddle carriers at a container terminal with the special aspect of internal moves

Summary Besides loading and discharging of ships, trucks and railway internal transportations are performed at a container terminal. Those transports amount to about 100000 km a year at the Container Terminal of the Hamburger Hafen- und Lagerhaus AG. Different methods for the routing of the vehicles (Straddle Carriers) were tested to minimize no-load ways. Heuristics solving theMultiple Travelling Salesman Problem were applied to the routing problem as well as a method forsequencing insertions in printed circuit board assemblies andrules for machine scheduling. Simulation with real data indicated a total saving of 20–35% in no-load distances which correspond to about 20000 km a year. The routing solution was implemented into a radio data transmission system.      

Superinfection exclusion by T-even-type coliphages

When a bacterial cell is infected with a T-even coliphage, immunity to a superinfecting phage is rapidly established (superinfection exclusion). Two phage-encoded proteins, Imm and Sp, are responsible for this exclusion: Imm blocks DNA transfer across the plasma membrane and partially inhibits release of DNA from the superinfecting virion, and Sp inhibits local degradation of bacterial murein by a phage-associated lysozyme.     

Messung von Rayleighwellen zur Untersuchung der Erosion an der Oberfläche kristalliner Werkstoffe mit Hilfe der Doppelpuls-Holographie

Measuring Rayleigh Waves to Investigate the Erosion at the Surface of Crystalline Materials by Means Double-Pulse Holographic Interferometry The repeated impact of solid particles on a material surface results in erosion. For technical applications as the pneumatic transport the particle diameters are varying between 10^?610^?3 m, the mean particle velocities are up to 30 m/s. In order to investigate experimentally the mechanism of erosion for crystalline materials, planar plates of austenitic steel are damaged due to the repeated impact of spherical particles. The elastic and plastic deformations, which are produced by this impact, result in propagation of longitudinal and transverse elastic waves into the material and of Rayleigh waves along the material surface. The amplitude of the surface deflection due to a single impacting particle is only 10^?810^?7 m. At different states of damage the surface deflection which is caused by such an impact is measured by means of double-pulse holographic interferometry. Because of the small amplitude of the Rayleigh waves two-reference-beam holographic interferometry is required. The initial wear of the material is recognized by the disturbed propagation of the surface wave.