Statistical modeling of shaft resource and main pump units

According to the equation of the durability line and model of linear damage accumulation, a deterministic formula for calculating the life of the shaft of an oil pump with allowance for a mixture of loading modes, maximum, nominal, and minimum, is derived. According to this formula, by means of statistical modeling, the distribution density of the shaft resource and the reliability indexes are found. The algorithm makes it possible to forecast the resource characteristics of shafts at the initial stage of operation of pumps, which increases the safety of their operation and ensures the stability of regimes of pumping oil and petroleum products.     

Is time really important for research into contracting out public services in cities? Evidence for urban water management in Southern Spain

Local governments are responsible for the supply of important public services in cities. On many occasions the management of those services is externalized. There is extensive literature analyzing the explanations for the governance option taken by local governments, aiming to ascertain the reasons why the management of certain services is externalized. Recent research has highlighted the fact that time has not been contemplated by research dealing with explanatory factors in the decision to contract out municipal services. This is a key issue in order to identify the real reason behind policymakers’ decisions about the management of the services in cities. This paper tests the importance of taking into account time in the research into contracting out. This is undertaken by means of two methodological tests in the design of variables from a dataset containing 744 municipalities in Southern Spain. Using this empirical analysis as a basis, it is concluded that considering time contributes towards enhancing the specification of the model and that omitting this aspect could lead to misunderstanding the motivation behind such decisions.     

Efficiency convergence processes and effects of regulation in the nonspecialized retail sector in Spain

This work analyzes the effects of the regulation/deregulation processes carried out on the evolution of efficiency in Spanish retail-sector firms in the period 1996–2004. The results suggest that the regulation in this sector has had a considerable influence on firms’ efficiency, in particular, the legislation on the expansion of commercial opening hours after 2000. The results provide clear evidence of a convergence in firms’ efficiency from the initial year considered to superior levels. Moreover, the pattern of convergence differs in function of the region in which the firm operates. The evolution of efficiency given by the means of different groups of regulation intensity levels through the time seems to show clearly in the groups of high and low regulation. It is observed that the group of high regulation is the most efficient. The analysis of the firms as a whole confirms the convergence process. Considering the analysis for subperiods an improvement is observed for all regions in the period 2000 at 2004.     

Interactions of oxidized lipids with protein. Part XVI. Interactions of oxidized ethyl linoleate with collagen

The reaction of ethyl linoleate with collagen proceeded at 60 degrees C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decomposition. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fasted in the stage of maximum hydroperoxide content, and both ether-insoluble and ether-soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour-active carbonylic oxidation products with protein.     

Smart Edge Computing for 5 g/6 g Satellite IOT for Reducing Inter Transmission Delay

Mobile Networks and Applications - 5G/6G communication are first generation high speed wireless communication network which integrates the aerial data, terrestrial data and maritime data via...     

The Role of Network Topologies in the Optical Core of IP-over-WDM Networks with Static Wavelength Routing

In this paper, we present a performance analysis of network topologies for the optical core of IP-over-WDM networks with static wavelength routing. The performance analysis is focused on regular degree four topologies, and, for comparison purposes, degree three topologies are also considered. It is shown that the increase of the nodal degree from three (degree three topology with smallest diameter) to four (degree four topology with smallest diameter) improves the network performance if a larger number of wavelengths per link is available. However, the influence of wavelength interchange on the nodal degree gain is small. The performance of regular degree four topologies with smallest diameter is also compared with the performance of mesh–torus topologies (which are also degree four topologies), and it is shown that the blocking probability of degree four topologies with smallest diameter is about two orders of magnitude lower than the blocking probability of mesh–torus topologies. It is also presented a performance comparison of WDM-based networks with nodal degrees ranging from two to five and it is shown that the increase of the nodal degree from two to three leads to high nodal degree gains, while de increase of the nodal degree from four to five leads to low nodal degree gains. These results show that degree three and degree four topologies are very attractive for use in the optical core of IP-over-WDM networks.     

Stimulating Cooperation in Self-Organizing Mobile Ad Hoc Networks

In military and rescue applications of mobile ad hoc networks, all the nodes belong to the same authority; therefore, they are motivated to cooperate in order to support the basic functions of the network. In this paper, we consider the case when each node is its own authority and tries to maximize the benefits it gets from the network. More precisely, we assume that the nodes are not willing to forward packets for the benefit of other nodes. This problem may arise in civilian applications of mobile ad hoc networks. In order to stimulate the nodes for packet forwarding, we propose a simple mechanism based on a counter in each node. We study the behavior of the proposed mechanism analytically and by means of simulations, and detail the way in which it could be protected against misuse.