Neural Network Model of Estimation of Body Mass Index Based on Indirect Input Factors

A well-prepared One of the main concerns of people in developing and developed societies is increasing the Body Mass Index (BMI) level. BMI, in fact can be considered as an indicator of overall health condition. Genetic aspects aside, the BMI level is affected by different factors, such as socio-economic, environmental, and physical activity level. This study investigated the effect of different factors on the BMI level of a sample population of 470 adults of three residential neighborhoods in Shiraz, Iran. The Pearson correlation coefficient, independent sample T-test and One Way ANOVA were used to extract the variables which significantly influenced the BMI. The statistical analysis showed that despite the apparent association of BMI with physical activity level, it is influenced by several factors such as age, residence record, number of children, distance to bus or taxi stop, indoor or sport exercise. Then, an Artificial Neural Network (ANN) was applied to predict the level of personal BMI. Artificial Neural Network-based methodology results showed that the generalized estimating ANN model was satisfactory in estimating the BMI based on the introduced pattern

Postendovascular thoracic aortic repair subclavian steal syndrome revealed by severe headache

AbstractSubclavian steal syndrome (SCSS) has been known since 1960 in the medical literature. Its principal cause is atherosclerosis responsible of occlusion of the subclavian artery (SCA). It is the pathological process in which blood flows in reverse direction from the vertebral artery (VA) to the SCA. Usually asymptomatic, but a variety of symptoms may develop involving the vertebro-basilar and/or the carotid territories and may be precipitated by exercise of the upper extremity. In some circumstances it can be iatrogenic complicating the course of a thoracic endovascular aortic repair (TEVAR) when the left SCA is covered by the endoprosthesis, which is a necessity many times giving the frequent proximity of the acute thoracic pathologies to the origin of this vessel.We present a case of severe headache occurring after a TEVAR with intentional coverage of the origin of the left SCA. This headache was the only symptom from which the patient complained, and which disappeared immediately after carotid-SCA bypass. Other devastating complications can happen, which gave as a concern about the management of SCA when decision to practice a TEVAR is taken

Adsorption process of n-alkanes onto BAX-1100 activated carbon: Theoretical estimation of isosteric heat of adsorption and energy distribution of heterogeneous surfaces

Adsorption of the n-alkane series, C1-C7, on Westvaco BAX-1100 activated carbon were measured over very broad ranges of temperature (293-393 K) and pressure (0.06-4964 Torr), depending on the n-alkane. Different behaviors of experimental adsorption isotherms were observed where various steps were noticed depending on the adsorbate length. A heterogeneous Gauss-monolayer model was developed based on statistical physics approach to evaluate the adsorption energy distribution (AED). Surface heterogeneity was evaluated and confirmed from isosteric heat of adsorption; where the adsorption of longer n-alkanes is energetically more favorable. A new equation was obtained from AED analysis to calculate the isosteric heat of adsorption. A notable difference between the adsorption isosteric heats estimated from AEDs and those obtained from classical Clausius-Clapeyron equation was observed at very low and high capacities. This difference was explained by the fact that, the gas behaves non-ideally at high pressure range. On the other hand, the absolute percentage deviation in adsorbed phase heat capacity was evaluated from the isosteric heat of adsorption predicted from the AED analysis. This percentage deviation increases when increasing the chain length of the alkane. 2018 Elsevier B.V.Scopu

Mitigation of Condensate Banking Using Thermochemical Treatment: Experimental and Analytical Study

Condensate banking is a common problem in tight gas reservoirs because it diminishes the gas relative permeability and reduces the gas production rate significantly. CO2 injection is a common and very effective solution to mitigate the condensate damage around the borehole in tight gas reservoirs. The problem with CO2 injection is that it is a temporary solution and has to be repeated frequently in the field in addition to the supply limitations of CO2 in some areas. In addition, the infrastructure required at the surface to handle CO2 injection makes it expensive to apply CO2 injection for condensate removal. In this paper, a new permanent technique is introduced to remove the condensate by using a thermochemical technique. Two chemicals will be used to generate in situ CO2, nitrogen, steam, heat, and pressure. The reaction of the two chemicals downhole can be triggered either by the reservoir temperature or a chemical activator. Two chemicals will start reacting and produce all the mentioned reaction products after 24 h of mixing and injection. In addition, the reaction can be triggered by a chemical activator and this will shorten the time of reaction. Coreflooding experiments were carried out using actual condensate samples from one of the gas fields. Tight sandstone cores of 0.9 mD permeability were used. The results of this study showed that the thermochemical reaction products removed the condensate and reduced its viscosity due to the high temperature and the generated gases. The novelty in this paper is the creation of micro-fractures in the tight rock sample due to the in-situ generation of heat and pressure. These micro-fractures reduced the capillary forces that hold the condensate and enhanced the rock relative permeability. The creation of micro-fractures and in turn the reduction of the capillary forces can be considered as permanent condensate removal

Gas Production from Gas Condensate Reservoirs Using Sustainable Environmentally Friendly Chemicals

Unconventional reservoirs have shown tremendous potential for energy supply for long-term applications. However, great challenges are associated with hydrocarbon production from these reservoirs. Recently, injection of thermochemical fluids has been introduced as a new environmentally friendly and cost-effective chemical for improving hydrocarbon production. This research aims to improve gas production from gas condensate reservoirs using environmentally friendly chemicals. Further, the impact of thermochemical treatment on changing the pore size distribution is studied. Several experiments were conducted, including chemical injection, routine core analysis, and nuclear magnetic resonance (NMR) measurements. The impact of thermochemical treatment in sustaining gas production from a tight gas reservoir was quantified. This study demonstrates that thermochemical treatment can create different types of fractures (single or multistaged fractures) based on the injection method. Thermochemical treatment can increase absolute permeability up to 500%, reduce capillary pressure by 57%, remove the accumulated liquids, and improve gas relative permeability by a factor of 1.2. The findings of this study can help to design a better thermochemical treatment for improving gas recovery. This study showed that thermochemical treatment is an effective method for sustaining gas production from tight gas reservoirs