Derivation and Validation of the Friction, Gravitational, and Air Forces Encountered during Installation of Fiber Optic Cable

This paper presents an introduction to fiber optic cable and the fiber optic communication system. An important phase in the supply of this new technology is to transport the fiber optic cable to the vicinity of service. Cable pulling and cable blowing - laminar flow; piston type - are the two main methods of installing fiber optic cable. Both methods of installation have limiting factors that need to be evaluated in order to perform a successful installation. The limiting factors for laminar type cable blowing are further discussed in this paper. A method was proposed to determine the forces - friction, gravitational, and air blowing forces - acting on a cable during installation. The forces were derived and an experiment was performed to verify the pressure gradient equation. Another experiment was conducted to determine the resistance to bend of a cable in order to predict the normal force exerted on the inner-duct by the cable in a bend section. The derived equations along with the relevant experimental results were used to create a program using Microsoft Excel VBA. The result of the program was compared to the result a real-life installation for validation. The program predicted a 12.7% greater installation distance. However, the program did not account for undulations that were present in the installation route and air loss from the fiber optic installation machine

Building a reliable and secure management framework for software-defined networks

Title from PDF of title page viewed December 15, 2021Dissertation advisor: Sejun SongVitaIncludes bibliographical references (pages 101-109)Thesis (Ph.D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2021The Software-Defined Networking (SDN) technologies promise to enhance the performance and cost of managing both wired and wireless network infrastructures, functions, controls, and services (i.e., Internet of Things). However, centralized management in softwarization architecture poses new security, reliability, and scalability challenges. Significantly, the current OpenFlow Discovery Protocol (OFDP) in SDN induces substantial issues due to its gossipy, centralized, periodic, and tardy protocol. Furthermore, the problems are aggravated in the wireless and mobile SDN due to the dynamic topology churns and the lack of link-layer discovery methods. In this work, we tackle both security and reliability management issues in SDN. Specifically, we design and build a novel multitemporal cross-stratum discovery proto- col framework, which efficiently orchestrates different reliability monitoring mechanisms over SDN networks and synchronizes the control messages among various applications. It facilitates multiple discovery frequency timers for each target over different stratum instead of using a uniform discovery timer for the entire network. It supports many common reliability monitoring factors for registered applications by analyzing offline and online network architecture information such as network topologies, traffic flows, virtualization architectures, and protocols. The framework consists of traffic-aware discovery (TaDPole), and centrality-aware protocol (CAMLE) facilities. We implemented the framework on Ryu controller. Extensive Mininet experimental results validate that the framework significantly improves discovery message efficiency and makes the control traffic less bursty than OFDP with a uniform timer. It also reduces the network status discovery delay without increasing the control overhead. We then evaluated the security issues in SDN and proposed an SDN-based Wormhole Analysis using the Neighbor Similarity (SWANS) approach as a novel wormhole countermeasure in a Software-defined MANET. As SWANS analyses the similarity of neighbor counts at a centralized SDN controller, it apprehends wormholes not only without requiring any particular location information but also without causing significant communication and coordination overhead. SWANS also countermeasures various false-positive and false-negative scenarios generated by the Link Layer Discovery Protocol (LLDP) vulnerability. We performed extensive studies via both analysis and simulations. Our simulation results show that SWANS can detect wormhole attacks efficiently with low false-positive and false-negative rates.Introduction -- Background -- Literature review -- Traffic-aware discovery protocol for software-defined wireless and mobile networks -- Centrality-aware multitemporal discovery protocol for software-defined networks -- SDN-based wormhole analysis using the neighbor similarity for a Mobile Ad hoc Network (MANET) -- Conclusions and future wor

Some important aspects in Moringa oleifera Lam. micropropagation

Type and source of explant as well as the type of cytokinin were important factors for successful moringa micropropagation. Explants obtained from in vitro grown plant materials were better than others obtained from soil growing seedlings. In addition, nodal segments were better than shoot cuttings in terms of number of shoots/ explants, frequency of shoot formation and number of nodes/shoot. While callus formation on the base of nodal segment on BAP containing media were higher than those of KIN, especially under the influence of high concentration as an aspect of vitrification, BAP was better than KIN in moringa multiplication. Low nutrient medium (half strength MS) supplemented with 0.5 mg l-1 IAA was essential for successful root formation. The suitable conditions for moringa micropropagation on full strength MS or SH may exert low stress and low need to raise the expression of SOD and POX. On the other side, stress due to over increase of chemical components of double MS medium or low nutrient content of half strength MS, B5 or WPM expressed the highest number and staining intensity of SOD and POX bands, vice versa was detected in case of CAT.</p

Moving carbon between spheres, the potential oxalate-carbonate pathway of Brosimum alicastrum Sw.; Moraceae.

Aims The Oxalate-Carbonate Pathway (OCP) is a biogeochemical process that transfers atmospheric CO2 into the geologic reservoir as CaCO3; however, until now all investigations on this process have focused on species with limited food benefits. This study evaluates a potential OCP associated with Brosimum alicastrum, a Neotropical species with agroforestry potential (ca. 70–200 kg-nuts yr−1), in the calcareous soils of Haiti and Mexico. Methods / results Enzymatic analysis demonstrated significant concentrations of calcium oxalate (5.97 % D.W.) were associated with B. alicastrum tissue in all sample sites. The presence of oxalotrophism was also confirmed with microbiological analyses in both countries. High concentrations of total calcium (>7 g kg−1) and lithogenic carbonate obscured the localised alkalinisation and identification of secondary carbonate associated with the OCP at most sample sites, except Ma Rouge, Haiti. Soils adjacent to subjects in Ma Rouge demonstrated an increase in pH (0.63) and CaCO3 concentration (5.9 %) that, when coupled with root-like secondary carbonate deposits in Mexico, implies that the OCP does also occur in calcareous soils. Conclusions Therefore this study confirms that the OCP also occurs in calcareous soils, adjacent to B. alicastrum, and could play a fundamental and un-accounted role in the global calcium-carbon coupled cycle

Microalgal biorefineries

ABSTRACT: Microalgae-based bioproducts remain expensive mainly due to microalgae cultivation, harvesting, and downstream processing costs. Nonetheless, microalgae are a high potential source of several biofuels, biofertilizers, and bioproducts (e.g., carbohydrates, long-chain fatty acids, pigments, and proteins), which can provide important nutritional, cosmetical, pharmaceutical, and health benefits. In addition, they are able to perform wastewater bioremediation and carbon dioxide mitigation. This not only contributes to a more sustainable microalgae production, with environmental benefits, but also offers cost savings on the whole process. Hence, from these small cellular factories, a large source of compounds and products can be obtained, providing a real microalgal-based biorefinery. This type of approach is crucial for the full application and commercialization of microalgae in a large range of products and industries, with added benefits for bioeconomy and society in general. This chapter addresses the potential transformation of microalgal biomass into a wide range of marketable products, presenting examples of experimental microalgae-based biorefineries grown in an autotrophic mode at a laboratory scale.info:eu-repo/semantics/publishedVersio

Effect of Temperature on Buckling of Composite Materials Column

A theoretical and experimental investigation pertaining to the buckling behavior of slender fiber reinforced polymer columns subjected to axial loading under varying temperatures (from room temperature to 50℃). Two groups of composite materials were used for manufacturing of test specimens, the first consist of perlon fiber as a reinforcement and acrylic resin as a bonding matrix, while the second consists of a combination of perlon and carbon fibers as reinforcement. The composite specimens were fabricated by vacuum molding technique and cut according to ASTM D-638 for conducting tensile test. The data from tensile test were used to calculate the effective slenderness ratio and defining the column as Euler buckling column. An experimental rig was designed, manufactured and calibrated to study the effect of thermal and buckling load subjected to columns. Numerical analyses pertaining the buckling behavior for both groups were conducted. The results show that the temperature has a considerable effect on properties of fiber reinforced polymer composites where the value of critical load and Young's Modules decrease with the increase of temperature for both groups. Perlon & Carbon reinforcement composites gave best mechanical properties, which make them the best candidate to improve the buckling resistance characteristics of composite materials