Comparative analysis of clustering-based remaining-time predictive process monitoring approaches

Predictive process monitoring aims to accurately predict a variable of interest (e.g. remaining time) or the future state of the process instance (e.g. outcome or next step). Various studies have been explored to develop models with greater predictive power. However, comparing the various studies is difficult as different datasets, parameters and evaluation measures have been used. This paper seeks to address this problem with a focus on studies that adopt a clustering-based approach to predict the remaining time to the end of the process instance. A systematic literature review is undertaken to identify existing studies that adopt a clustering-based remaining-time predictive process monitoring approach and performs a comparative analysis to compare and benchmark the output of the identified studies using five real-life event logs

Spatial Modelling and Analysis of an Electrical Distribution System

The distribution of electrical energy to end-users in Nigerian communities is faced with diverse spatial problems leading to low voltage, overload on equipment, difficulties in fault tracing and delay in fault clearing. The traditional management system is not only manual but also has flaws such as difficulties in searching and updating previous records as well as no real-time information on their distribution assets. In this study, a geospatial technique was employed for effective management of the electricity distribution system in Malete, Kwara State, Nigeria. Spatial information of distribution asset was collected from the field and used in the structural modelling of the distribution network in the ArcMap software. Analysis of the model and the available information showed that 80 % of the transformers were not properly located at the centroid of the load. The span of the network fairly conformed to standard as only 45.73 % were within 45-50 m. The result also showed that 40 % of the transformers were overloaded with an unbalanced load, hence the need for restructuring of the network

Process modeling and optimization of magnetic field pretreatment of sweet pepper and fluted pumpkin leaf

Modeling and optimization of magnetic field (MF) pretreatment of sweet pepper (SP) and fluted pumpkin leaf (FPL) were done with Response Surface Methodology. Three pretreatment factors combined were: types of MF (static, pulse and alternating), MF strength (5 - 30 mT) and pretreatment time (5 - 25 min). All the MF pretreated, control (blanched) and fresh samples were dried at 50 ˚C and analyzed for fibre, vitamin C, potassium, microbial load and colour; data obtained were used for modeling and optimization of the process. Results showed that the selected 30 developed model equations reliably described the characteristics of the process with adequate precision values of greater than four (4) and significant probability values (P ≤ 0.05) in all cases. The best optimized process conditions for the MF pretreatment process are Static MF at 14.31 mT magnetic field strength and 16.40 min pretreatment time for SP and Alternating MF at 10.42 mT magnetic field strength and 9.96 min pretreatment time for FPL. Magnetic field (non-thermal) pretreatment was able to achieve all the optimization goals better than blanching (thermal) pretreatment

Acute and chronic effects of Δ⁹-tetrahydrocannabinol (THC) on cerebral blood flow:A systematic review

Acute and chronic exposure to cannabis and its main psychoactive component, Δ 9-tetrahydrocannabinol (THC), is associated with changes in brain function and cerebral blood flow (CBF). We therefore sought to systematically review the literature on the effects of THC on CBF following PRISMA guidelines. Studies assessing the acute and chronic effects of THC on CBF, perfusion and volume were searched in the PubMed database between January 1972 and June 2019. We included thirty-four studies, which altogether investigated 1259 humans and 28 animals. Acute and chronic THC exposure have contrasting and regionally specific effects on CBF. While acute THC causes an overall increase in CBF in the anterior cingulate cortex, frontal cortex and insula, in a dose-dependent manner, chronic cannabis use results in an overall reduction in CBF, especially in the prefrontal cortex, which may be reversed upon prolonged abstinence from the drug. Future studies should focus on standardised methodology and longitudinal assessment to strengthen our understanding of the region-specific effects of THC on CBF and its clinical and functional significance. </p

ANALYTICAL INVESTIGATION OF THE EXTRACT OF LEMON GRASS LEAVES IN REPELLING MOSQUITO

ABSTRACT: The main objective of the work was to extract the active ingredient in Cymbopogon citratus leave and to formulate a mosquito repellent cream naturally obtained from medicinal plants instead of commonly available synthetic repellents and insecticides such as N-Diethyl-3methylbenzamide (DEET), which are carcinogenic and non eco-friendly. The formulation of cream have smooth texture with a pH 7.30 which is non-irritant and suitable for the skin. The efficacy of the extract of Lemon grass (Cymbopogon citratus) was investigated on mosquito in this research using different concentrations of the oil extract. The sample (cream) with the highest concentration of the active ingredient extracted was found to be most effective in repelling mosquitoes. Ethanol and Hexane were used to extract the essential oil and Gas chromatography-mass spectrophotometer (GC-MS) was used to analyse the constituents in the extracted active oil. The most abundant constituents observed in the hexane extract are cyclotetracosane (4.05%) and naphthalene (5.03%). Hexane proved to be a better solvent by giving a percentage yield of 7.8% of essential oil while ethanol a percentage of 2.9%

Topside Pipeline Design for Slug Attenuation and Increased Oil Production

In oil and gas production system, slugging is frequently encountered when gas-liquid mixtures are transported through a common pipeline-riser system. This phenomenon usually manifests in significant fluctuation of flow and pressure which can impact the production system negatively. Topside choking is usually employed as a mitigation technique but with its attendant reduction in production capacity. The objective of this study therefore is to investigate the optimisation of topside pipeline diameter and choking for effective slug attenuation and optimised oil production. In this paper, a new method for slug flow attenuation has been proposed. The potential of using effective topside pipeline- diameter design for slug flow attenuation was theoretically shown. Numerical studies were also done to show that the concept can indeed be adapted for effective slug attenuation using an industrial software. Experimental studies were conducted in a 4” pipeline -riser system to validate the numerical and theoretical studies. The results showed that the optimised design of topside pipe diameter has potential for slug flow attenuation at larger valve opening which effectively translates to lower pressure and increased oil production. For the case studied, up to 49% reduction in the pressure drop across the topside choke valve was reported which practically implied increased flow capacity. An optimum volume which satisfied size, system stability and production constraints was obtained