University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Biogas production from maize hybrids.

Abstract: There is an increasing world wide demand for energy crops and animal manures for biogas production. This research project was aimed at optimising anaerobic digestion of maize, using a laboratory digester, and finding out which maturity class of corn and which hybrid of a particular maturity class produces the highest rate of biogas and biomethane. Also the chemical composition of gases was studied. The corn hybrids of FAO 300 – FAO 400, FAO 400 – FAO 500 and FAO 500 – FAO 600 maturity class were tested. Experiments took place in the lab for 35 days within four series of experiments with four repetitions according to the method DIN 38 414. Results show that the highest maturity class of corn (FAO 400, FAO 500) increases the amount of biomethane. The greatest gain of biomethane per hectare according to maturity class is found with hybrids of FAO 400 (7768.4 Nm 3 ha −1 ) and FAO 500 (7050.1 Nm 3 ha −1 ) maturity class. Among the corn hybrids of maturity class FAO 300 – FAO 400, the hybrid PR38F70 gives the greatest production of biomethane per hectare (7646.2 Nm 3 ha −1 ). Among the hybrids of maturity class FAO 400 – FAO 500, the greatest amount of biomethane was achieved by the hybrid PIXXIA (9440.6 Nm 3 ha −1 ). Among the hybrids of maturity class FAO 500 – FAO 600 the hybrid CODISTAR (FAO 500) gives the highest production of biomethane (8562.7 Nm 3 ha −1 ). Production of biomethane varied with corn hybrids from 50 to 60% of produced biogas.

Graphs S(n, k) and a Variant of the Tower of Hanoi Problem

Abstract: For any n ≥ 1 and any k ≥ 1, a graph S(n, k) is introduced. Vertices of S(n, k) are n-tuples over {1, 2,. . . k} and two n-tuples are adjacent if they are in a certain relation. These graphs are graphs of a particular variant of the Tower of Hanoi problem. Namely, the graphs S(n, 3) are isomorphic to the graphs of the Tower of Hanoi problem. It is proved that there are at most two shortest paths between any two vertices of S(n, k). Together with a formula for the distance, this result is used to compute the distance between two vertices in O(n) time. It is also shown that for k ≥ 3, the graphs S(n, k) are Hamiltonian.