bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-Time Traffic Flow Controls at Signalised Intersections: A Case Study of the Said-Jawda intersection in Karbala
Authors: Almuhanna Raid R.A. , Salman Shahed A.
Published: March 2021

As the problem of urban traffic congestion increases, the need for advanced technology and equipment to be introduced for the improvement of traffic control also increases. Traffic problems have worsened last years due to significant increases in the number of vehicles on the roads and the limited availability of resources in the current infrastructure. The easiest way to control traffic lights is to use timer for each phase; however, another way is to use electronic sensors to detect vehicles to supply the required traffic signals for a given cycle. To enable effective traffic flow through a signalised intersection, this study proposes a system for controlling traffic lights that detects vehicles using videos and imaging techniques instead of electronic sensors embedded in the pavement. Four cameras were installed at a height of three metres on the four approaches to a set of traffic lights. The captured images were then analysed using digital image processing based on Python to facilitate vehicle detection and traffic condition analysis. The work is thus divided into two segments: data collection and traffic control solution generation. The results indicated that using the proposed automated system could produce more effective traffic control as compared to SIDRA fixed-time controls, with delay reduced within the range 40 to 90% and cycle length reduced by 30 to 65%.
Assessment of Geo-Mechanical Characteristics of Carbonate Rocks Using Non-destructive Pulse Velocity Measurements
Authors: Shaban Alaa M. , Hayder Mohammed R. , Al-Hashimi Zahraa H.
Published: March 2021

Determining the geomechanical characteristics of the rock formations is critical to the design and analysis of various underground geotechnical structures. This research applied an experimental approach to determining the properties of rock cores based on ultrasonic wave velocities. Three types of carbonate rocks sampled from three different regions were thus experimentally tested and evaluated, with the regions from which the rock samples were collected being located in south-eastern, south-western, and north-eastern areas of Iraq. The geomechanical characteristics of the carbonate rocks were compiled based on ultrasonic pulse velocity tests and uniaxial compressive strength tests implemented under two sets of laboratory testing conditions: dry and saturated. The data are thus reported and discussed for both dry and saturated rock specimens. In general, the results showed a reduction in rock engineering properties with increasing moisture content. The measurements of compressional and shear wave velocities were analysed and correlated with various mechanical properties including: strength, elastic moduli, bulk density, Poisson’s ratio and Lame’s constant; the results of this process revealed that there is a strong correlation between velocity measurements and rock engineering properties. Several statistical relationships with high degrees of regression coefficient are thus proposed to efficiently the evaluate geomechanical properties of carbonate rocks based on compressional and shear wave measurements.
The Impact of Cultural Context on Innovative Iraqi Architecture: Houses Façades as a Case Study
Authors: Husain Hisham A , Al-Slik Ghada
Published: March 2021

This research aimed to discuss the notions of innovation and cultural context, common terms in architecture, with regard to their various applications in attempts to achieve coherent results related to context. As a case study, the research analysed the practice of private house design at façade level in Baghdad city in the 1950s and 1960s, which act as a benchmark for modern Iraqi architecture. The results suggest that changes in cultural context enhance architectural practice by inspiring designers, leading to the introduction of innovative models that in turn elevate practice and improve cultural contextual values with regard to architecture.
Probabilistic Prediction of Scouring around Piers using Monte Carlo Simulation
Authors: Al Rammahi Ali Hussein Jaber , Khassaf Saleh Issa
Published: March 2021

Assessing local scour around a pier is important in terms of creating a good design for any bridge. Many equations are available to predict local scour around pier, though the reliability of these must be checked using statistical tools. A Monte Carlo simulation was thus used in this study to check the probabilistic accuracy of lab equations of local scour around a test pier so that the observation data and prediction equation were both tested probabilistically before use in simulation. The parameters of the prediction equation were specified based on the probabilistic and deterministic variables, with average velocity, critical velocity, water depth, median bed diameter, and Froude number being the unknown variables. The deterministic variables were the diameter of the pier and the spacing from the pier to the abutment. The optimum number of iterations utilised in the Monte Carlo simulation was also investigated based on standard deviation. The independent terms of the prediction equation for the simulation model were derived based on the original distribution of the equation of local scour and the relevant statistical values. The distribution of observation data of local scour was assumed to be normal, while the simulation model was lognormal. The input data was then used to check the probabilistic outcomes of the deterministic equation. The deterministic equation of local scour gave the results at the corresponding confidence level of about 20%, depending on the curve of a cumulative probability distribution. The probabilistic results were thus deemed preferable for the computation of local scour around the pier.
Zeolite as a natural adsorbent for nitrogenous compounds being removed from water
Authors: Abdulredha M , Kadhim N R , Hussein A H , Almutairi M , Alkhaddar R , Yeboah D , Hashim K
Published: March 2021

Water is vital to the survival of humans and all other life forms, yet many sources of freshwater are being contaminated due to pollution, significantly limiting freshwater availability, and threatening human existence. Nitrates and ammonium are common water contaminants whose concentrations in water have increased significantly due to the excessive use of fertilisers. High concentrations of such contaminants in water can lead to multiple health issues, and thus controlling the concentration levels of these pollutants in water grows into the main task for environmental scientists. A natural zeolite filter was employed in this study to minimise traces of contaminants in water. Samples of synthetic polluted water were prepared that contained 50 mg/L of each contaminant for the laboratory tests. Testing natural zeolite doses ranging from 1 to 5 g/L at various pH levels (between 3 and 10) showed that a zeolite filter significantly improved the water quality from the initial concentrations of each pollutant by between 10 and 50 mg/l. In particular, more than 93% of both contaminants (nitrate and ammonium) were removed by using a 5 g/L dose of zeolite in a neutral pH level range for 120 minutes.
Nano and bio-composites and their applications: A review
Authors: Ali M S , Al-Shukri A A , Maghami M R , Gomes C
Published: March 2021

Recent developments in the materials science field have highlighted the need for further composite materials study, especially with regard to bio and nano-composites, as their abilities to meet modern requirements with regard to facilitating technological advancement is far greater than those of monolithic materials. There are several advantages to nano and bio-composites as compared to conventional materials, including properties such as fatigue resistance, impact resistance, stiffness, corrosion resistance, biodegradability, thermal conductivity, low relative density, environmentally friendly waste stages, and high specific strength. Recent years have seen the discovery of several new high-performing composite materials, and improvements in the fields of aviation, automobile, adhesion, building, and electronic engineering also support the adoption of more general utilisation of nano and bio-composites in a much wider range of applications than those for which they were originally designed. This paper thus highlights and reviews information on bio- and nano-composite materials to determine current trends in how these materials are used in the various fields of engineering in numerous applications, and to examine the role of nanotechnology in the enhancement of composite properties.
A Novel Review on Nano-fluid and Phase Change Material based Photovoltaic Thermal (PV/T) Systems
Authors: Shojaeefard M H , Sakran N B , Sharfabadi M M , Davoudi N
Published: March 2021

In this paper, advanced researches on photovoltaic thermal systems are reviewed. First, the PV/T concept and it’s advantageous and disadvantageous are mentioned. Then the latest innovations for improving the performance of PV/T systems such as applying Nano-fluid and Phase Change Material (PCM) and also hybrid-Nano-fluid are discussed. The results of numerical, energy, exergy and experimental studies in this issue have been considered. Investigations show that the utilization of Nano-fluid and PCM improve the thermal efficiency of the PV/T systems and reduce the consumption of fossil fuels.
Simulation of cam-based infinitely variable transmission
Authors: Faleh M , Al-Hamood A , Majeed M H
Published: March 2021

Infinitely variable transmission (IVT) is a system that gives a continuous (non-discrete) variation that includes zero in transmission ratios between two rotating elements. In this paper, a cam based IVT mechanism was designed and simulated using SolidWorks software containing two identical units. Each unit included a cam with a follower and oscillatory slotted links pivoted at a hinge that could be moved vertically by altering the transmission ratio, achieved by using a hydraulic ram or a power screw. system units also include a grooved wheel and a follower or actuator. During operation, the grooved wheels displayed an oscillating rotational motion, so that they are connected to the output shaft via one-way clutches (ratchets) to give the output shafts one-way directional motion. The cam profiles are designed and investigated within the system with regards to performance. A combination of uniform velocity and 1-5 polynomial profiles where selected and designed for the current study In general, the results obtained from the simulation showed compatibility with the expected theoretical results derived from the design of the current IVT system. These results indicated uniform velocity during the power stroke in each unit for all parts in the units. However, the ratchets used in this study produced a noticeable fluctuation in the angular velocity of the output shaft, and further work on the selection and development of more efficient ratchets is thus strongly recommended.
Experimental study on performance improvement of air cooler incorporating two-stages
Authors: Muhsen M M , Abdulrasool A A , Sadiq B R
Published: March 2021

An experimental study was conducted using two compact heat exchangers (air-cooled) to improve indoor air conditions in Iraq summer weather. The layout of the rig is constructed in such a way that the air flows through a two-stage direct/indirect cooling system to minimize the high air temperature. The water in the basin of the unit was then unitized to the second stage as a working fluid. The findings showed that the temperature could be changed to a point 13% lower than that achieved by the standard design at an affordable cost and in an environmentally appropriate manner. The difference in the humidity ratio was also comparatively reduced with respect to the original discharge from the evaporative cooler alone, as the new system eliminates only sensible heat. This new design, is well-suited to hot and dry conditions where the cost of the air conditioning system based on refrigerants is high, the percentage increase in the overall effectiveness is about 25%.
Investigating the effects of post-heat treatment on residual stress in AlSi12 parts processed with Selective Laser Melting
Authors: Ponnusamy P , Masood S H , Ruan D , Palanisamy S , Rashid R A
Published: March 2021

Residual stresses are the stresses that remain on a part after the original cause of any stress has been removed. In Selective Laser Melting (SLM), an additive manufacturing process, residual stress occurs in the created part due to rapid melting and rapid solidification; these stresses are responsible for distortion, which must therefore be minimised or eliminated. Residual stresses can be reduced in SLM built parts by the application of post heat treatment, and this process is investigated in this study. X-ray diffraction was employed for the experimental analysis of the residual stresses in AlSi12 parts processed by SLM that were then subjected to heat treatments at different temperatures, ranging from 200 °C to 500 °C, in order to investigate how residual stresses and microstructure changes vary with heat treatment temperatures.
An examination of the effect of adding zirconia to bioactive glass-ceramic properties
Authors: Aswad M A , Sabree I K , H S Abd Ali
Published: March 2021

Zirconia has been frequently used as a bone substitute based on its material properties and bioinert nature, which make it a suitable composite material for multiple bio applications. In this study, 45S5 bioactive glass ceramic (BGC) (45% SiO2, 24.5% CaO, 24.5% Na2O, 6% P2O5) was synthesised using a melt derivation process. The biocomposite for testing was prepared by mixing 1wt% of ZrO2 with the prepared BGC. The sample of simple BGC was sintered at 900 °C, while the composite was sintered at 1170 °C. XRD diffraction testing confirmed the formation of Na2Ca2Si3O8 and Na2Ca2Si3O9 phases in the structure of pure the BGC sample, while the composite displayed the emergence of tetragonal and monoclinic ZrO2 peaks in addition to bioglass ceramic peaks. SEM testing also showed distinct differences between the structures. The results suggest that adding ZrO2 to the bioactive glass matrix improves its mechanical properties and increases density while decreasing the porosity value.
Frequency-Based Time-of-Use Pricing with Multiple Battery-buffered Smart Loads
Authors: Zurfi Ahmed , Altahir Ali Abdul Razzaq , Al-Doori Bilal. , Zhang Jing
Published: March 2021

This work discusses a new time-of-use energy pricing structure based on grid frequency. Under the proposed pricing structure, energy cost depends on the time of frequency deviation and the period during which energy is used. This pricing mechanism is intended for use with multiple behind-the-meter home batteries as part of a frequency-controlled smart load strategy known as a battery buffered smart load. The load energy consumption from the grid and energy storage rates thus depend on the frequency deviation and hours of use, which means that the proposed pricing encourages battery-using customers to not only utilise energy arbitrage, shifting peak demand but also to contribute to demand-side primary frequency control. The second contribution of this paper is the presentation of an operation strategy for multiple buffered battery smart load units in which charge and discharge decisions are made according to off- and on-peak period information to ensure continuous provision of primary frequency control under the proposed time of frequency division pricing. A MATLAB simulation of the proposed pricing and operation modes of the BBSL was conducted with multiple battery-buffered smart load to assess feasibility.
A Green Data Management Layer in Industrial IoT
Authors: Ghaderi A , Qavany Z , Movahedi Z
Published: March 2021

All Nowadays, industry 4.0, which aims at transforming industrial manufacturing systems to the smart factories, has gained considerable attention from both industry and academia. The Industrial Internet of Things (IIoT) plays a primordial role to achieve the objectives of Industry 4.0, by enabling the Cyber-Physical Production Systems (CPPS) to communicate and cooperate with each other and with humans both internally and across the participants of the supply chain. A communication model used commonly in IIoT networks consists of the publish-subscribe model, in which the data generated by sensor nodes are cached in a central controller to be subsequently consumed by actuator nodes. However, the traditional centralized data management is inappropriate for real application because of its communication overhead and inability to cope with strict delay requirements of IIoT applications and energy constraints of IIoT networks. To address these issues, we propose a Green Data Management Layer (GDML), which caches data distributedly in some IoT nodes, called proxy nodes, so that the network energy consumption is optimized while the constraints on data access latency and IoT nodes’ cache capacity are met. In this measure, the extra IoT nodes not involved in data transmission nor in data caching are switched off to prolong the battery lifetime of constrained IoT nodes. We modeled the aforementioned optimization problem as an Integer Linear Programming (ILP) and solved it using the CPLEX tool. The obtained results show that the proposed GDML outperforms significantly alternative solutions in terms of overall energy consumption, energy consumption devoted to data transmission, energy consumption devoted to keeping active the involved nodes, while the constraints on data applications latency and the cache size of IoT nodes are satisfied.
Domain-Specific Languages for IoT: Challenges and Opportunities
Authors: Salman Aymen J , Al-Jawad Mohammed , Tameemi Wisam Al
Published: March 2021

Internet of Things (IoT) is a multidisciplinary tool used by field experts to fabricate technology into their discipline; these fields experts thus need access to a simple, understandable and user-friendly programming language for this purpose. Domain-Specific Languages (DSL) have been developed to pave the way for such domain experts to integrate IoT capabilities into their everyday tasks. IoT is thus one of the main technologies targeting human day-to-day activities, and the concept of IoT has caused a general rethink and reimagining of the shape of life in the future. Many researchers are thus working on fields related to IoT such as networking, power consumption, data aggregation and fusion, finding ways to offer this new technology for end user access in a smooth and easy manner. Introducing new application development methods and using software engineering standards and tools that enable end-users to develop their own IoT applications is another aspect that has received attention in the last decade; however, this aspect requires more work from the research community. The main contribution of this paper is to highlight current efforts related to the IoT field and to perform quantitative analysis to highlight the current state of the art in both positive and negative terms, including the current limitations and obstacles faced by both end-users and field experts seeking to build their own IoT applications.
Simulation of EEG-Based Apparatus Control for Quadriplegic Patients
Authors: Mohammed Mohammed Jamal , Abed Jameel Kadhim , Mahdi Ali Jafer
Published: March 2021

The use of electroencephalogram (EEG) waves in the field of Brain Computer Interfaces (BCI) has recently attracted a lot of interest, with varied applications ranging from entertainment to medicine emerging, showing that EEG waves are suitable for controlling appliances through a microcontroller. This study presents an offline strategy for the extraction of digital control signals from brain EEG waves using MATLAB/SIMULINK. The principle is applied as follows: (i) the extraction of α- and β-bands from the original brain EEG wave; (ii) detection of the peaks of both bands; and (iii) calculation of the power density of both bands to classify the mental mode and to generate appropriate control signals. Simulation results including signal processing tracking for various EEG waves are demonstrated that verify the effectiveness of the proposed strategy in terms of using brain EEG waves for apparatus control.
The Correlation Between Gastrocnemius Muscle Thickness And Activity Limitations In Patients With Severe OA
Authors: Ghazwan Aseel , Alsaadan Waleed A , Rany Nadia
Published: March 2021

Muscle thickness offers an excellent indicator of maximal force generating capacity, and, accordingly, a reduction in muscle thickness may contribute to muscle weakness; this in turn may be related to functional limitations in patients undergoing total knee replacement. The purpose of this study was to correlate the morphologic changes in the gastrocnemius muscle in relation to muscle activity in subjects with severe knee osteoarthritis (OA), in order to establish an objective means of measuring muscle function and muscle recovery. Two subject groups participated in this study, one group of 10 non-pathological subjects (NP) and a separate group of 10 subjects with severe OA. The muscle thickness (MT) and EMG muscle activity (MA) of the medial gastrocnemius (MG) and lateral gastrocnemius (LG) were assessed using ultrasonography (US) and electromyography (EMG), respectively. The correlation between MA and MT was thus investigated, and linear regression analysis performed to determine prediction equations for muscle activity. The results showed that MA is highly related to MT for both MG and LG in NP subjects. The MA prediction equation based on linear regression analysis resulted in R2 values of 0.90 and 0.95 (p<0.05) for LG and MG, respectively, while in OA subjects, a good correlation was shown between MA and MT within the MG, with R2 = 0.80, though a more moderate correlation was found for LG, with R2 = 0.52. The thickness of the MG was not significantly increased during maximum voluntary contraction (MVC) as compared with the resting state, while the thicknesses of LG significantly increased, from 15 to 22 mm, on moving from resting to MVC. This study thus demonstrated that MG is more useful parameter than LG for the prediction of muscle force generating intensity in patients with severe OA.
Fuzzy logic control of a catalytic naphtha unit
Authors: Ahmed D F , Khalaf I H
Published: March 2021

This work examines the fuzzy logic-based control of a catalytic reformer. The control process requires development of an exact process model valid over a wide range of operating conditions. Two control methods, proportional integral derivative (PID) and Fuzzy-PID, were applied to determine the optimal operating conditions. The output temperature from the feedback fuzzy controller was sent to the PID controllers as a setpoint in the heating system loop, and two fuzzy logic systems, one in the forward path and one in the feedback path were developed to give setpoints for temperature control loops in the four reactors. A fuzzy logic-based optimal control scheme was established to increase the aromatics yield, subject to constraints on the inlet temperature of the reactors. A rigorous kinetic model was then developed by expressing the heat and mass balances under unsteady state conditions. This model was used to determine the temperature and concentration profiles of three main hydrocarbons, naphthenes, paraffins, and aromatics, across the four reactors. A reaction scheme involving 27 pseudo components connected using a network of 71 reactions for components in a wide range of carbon numbers was thus modelled. The simulation results for the model were compared with previous studies to validate the model, and good agreement was found between the reformate composition of the proposed model and the plant reformate composition and temperature. The simulation results also showed that the PID –Fuzzy controller is accurate but that it requires additional time to reach a steady state value.
Model-Based Design Workflows for Cyber-Physical Systems Applied to an Electric-Mechanical Coolant Pump
Authors: Höpfner Gregor , Jacobs Georg , Zerwas Thilo , Drave Imke , Berroth Joerg , Guist Christian , Rumpe Bernhard , Kohl Jens
Published: March 2021

Cyber-Physical Systems (CPS) connect mechanics, electrics and electronics as well as software. Considering the interactions between these domains is a major challenge in product development. Model-Based Systems Engineering (MBSE) enables cross-domain system development, based on commonly understood system architectures. However, there is still a gap in using MBSE for development, especially in mechanics. Systematic evaluation of design decisions based on system architecture models is not done. The strong simulation methods predicting physical product behaviour are not well connected to the evolving system architecture. We propose a new approach for connecting simulation and design models in a System Modelling Language (SysML) system model using the example of a combustion engine’s cooling circuit. The electric-mechanical coolant pump is chosen for design. The design processes of the hydrodynamic pump wheel and the volume flow controller are modelled as workflows in SysML. Here, we integrate design models for the pump wheel and the controller into the workflows. Thereby, parameters of the pump wheel and controller are calculated. Design results are automatically transferred to CAD. A workflow is created, testing the cooling circuit’s behaviour against requirements, combining a Simulink control model and a Simcenter Amesim heat transfer model. The approach results in a framework for automated design and test processes.
Extended Evaluation of Pitting Degradation Tests to Increase the Remaining Useful Life of Gear Wheels
Authors: Gretzinger Yvonne , Kroner Andreas , Henß Mark , Dazer Martin , Bertsche Bernd
Published: March 2021

Within this work, the potential of an operating strategy is analysed based on test runs in laboratory environment, field tests as well as simulations. The operating strategy is used to increase the remaining useful life of gear wheel pitting by reducing the local stress at the weakened tooth. The local stress reduction is achieved by applying an adapted periodic input torque to the transmission and shift the minimum in the area of the weakened tooth. All the other teeth undergo a higher stress and therefore compensate the reduction. To analyse the potential of this strategy, the evaluation of pitting degradation tests has to be extended to all teeth using data from test runs as well as field tests. Both analyses show great potential as many teeth are totally intact. Finally, a simulative approach was carried out to quantify the potential and to show a reference value for the accuracy of the measuring system. As a result, for an increase in lifetime of 10 %, the measurement system has to locate pittings with a size smaller than 1 % based on the total tooth flank. If the pitting is located even earlier, a maximum of 38 % increase in lifetime is possible.
Investigation of lubricant supply in rolling point contacts under starved conditions using CFD simulations
Authors: Fischer D , Goeldel S von , Jacobs G , Stratmann A , König F
Published: March 2021

High friction and wear in rolling bearings are prevented by a lubricating film, which separates the contacting surfaces. In rolling contacts with limited lubricant supply, the film thickness decreases at high rolling speeds, as more lubricant is displaced than replenished. This lubricant depletion is known as starvation and may induce mixed lubrication due to a low film thickness. When estimating the bearing lifetime, a fully flooded lubrication, i.e. an unlimited lubricant supply, is usually assumed. This leads to an overestimation of film thickness in operating ranges where starvation occurs. Thus, considering the onset of starvation is crucial to reduce the risk of premature bearing failures due to high friction and wear in the mixed lubrication regime. Therefore, this contribution presents a method, based on computational fluid dynamics (CFD) simulations, to calculate the onset of starvation in oil lubricated point contacts.
Influence of Model Detail Level on the Prognosis Quality of the Perceived Sound of an Electrified Passenger Car Powertrain
Authors: Drichel P , Jaeger M , Möller-Giebeler M , Berroth J , Schroder M , Behler G , Jacobs G , Hameyer K , Vorländer M
Published: March 2021

Complex and resource intensive multi-physical models which integrate the domains of electrotechnical, structural dynamics and acoustics are needed to predict the noise, vibration and harshness (NVH) behavior of an electric passenger car drive train. Because of the highly limited resources in product development process of cars, engineers request efficient models with a good balance between accuracy and model creation as well as calculation effort. Knowing about which components and effects influence the prognosis is essential to adjust this balance between accuracy and effort. Therefore, in this paper a method is presented to determine the influence of the model fidelity level on the prognosis quality of the perceived drive train-related airborne sound under the use of hearing tests to consider the human noise perception. The work is based on a high fidelity multi-physical NVH of a small, series-produced electric vehicle drivetrain which is validated in structure-and air-borne-noise against test bench measurements. The influence of model detail level on the prognosis quality is analyzed using the aforementioned method taking into account four exemplary variant calculations of the proposed model: (1) Power electronics harmonics vs. ideal sine electric machine current, (2) electric machine with vs. without production deviations, (3) modal damping parameters derived from component measurements vs. modal damping taken from literature, and (4) numeric vs. analytical sound calculation method.
Experimental Validation of a New Design Concept for the Increase of Efficiency of the Hydraulic Drive System in Mobile Working Machines
Authors: Geffroy S. , Brautlacht A. , Wegner S. , Gels S. , Schmitz K.
Published: March 2021

In mobile working machines like excavators, hydraulic actuators and drives are indispensable due to their advantages of a high power to weight ratio, robustness and the good power transmission over medium distances by the hydraulic fluid. Axial piston machines can deliver a large volume flow at a high operation pressure with high efficiency and are therefore widely used as system pump or drive motor. The three essential tribological contacts piston / bushing, sliding shoe / swash plate and valve plate / cylinder block strongly influence the machine’s efficiency and so the complete drive system. The paper on hand focuses on the experimental validation of a new design concept to increase the efficiency of the tribological contact between valve plate and cylinder block in an axial piston pump. Due to the different pressure forces at the high- and low-pressure side, the cylinder block tilts and holds this preferred position almost constant. Therefore, the gap height is not constant. In the area of minimum gap height, the danger of solid body contact increases. In addition, the heat dissipation is decreased, which can lead to local constant high temperature hot-spots. Both can destroy the surface structure or the coating. A new design concept has been developed to reduce these risks, thus increasing the efficiency, the lifetime and making it possible to dispense of leaded coating materials. In this design concept, pressure pockets are added in the area of minimum gap height. The simulation study shows a high potential of this concept. The experimental results of the prototype parts, which are measured on a special test rig and presented in this paper, confirm the simulations and validate the potential of the new design concept in this way.
Aerodynamic Design of Wingtip Devices Using Far-field Drag Decomposition
Authors: He Xiaolong , Chen Zheng , Tan Jie
Published: March 2021

Computational Fluid Dynamics (CFD) has become widely used for civil aircraft. However, the commonly used wall integration method for drag prediction based on Reynolds- averaged Navier-Stokes (RANS) equations still has some shortcomings. Far-field drag decomposition (FDD) method was developed as an alternative to improve the drag prediction accuracy and to provide a powerful analysis tool. FDD is capable of decomposing the drag into viscous, shock, induced, and spurious drag components, which provides invaluable insight into the relationship between drag and flow phenomena. Despite all the strengths, FDD is seldom used for aerodynamic shape design and optimization. In this paper, FDD was used to design wingtip devices for a business aircraft. Five spiroid and one blended winglet were compared with baseline wing and tip-extension configuration. Results indicate that all drag components were quantified successfully and the trade-off between induced drag and other drag components was better explained. The spiroid winglet with new foil gives the lowest total drag and wave drag.
Operational Scenario Analysis Method for Civil Aircraft Based on Requirement Capture
Authors: Yuwei He , Yuchen Sun , Xinai Zhang , Ximei Dai , Dongsheng Chen
Published: March 2021

Scenario analysis is an accepted method in civil aircraft requirements capture and validation.This paper introduces the operation scenario analysis method for requirement capture, including stakeholder identification, interaction activity analysis, design requirement capture, etc.Based on SysML language, the modeling and analysis of operation scenarios were carried out.Taking the push/tow scenario of civil aircraft as an example, the structure diagram, use case diagram, activity diagram and requirement diagram are formed by modeling. The design requirements in this scenario are captured through the interaction analysis between the different stakeholders and the aircraft.
Roadmap for increasing the Congolese mining industry involvement in the local community development
Authors: Michel Shengo Lutandula , Kime Meschack-Bill
Published: March 2021

The mining sector revenues of the Democratic Republic of Congo (DRC) have significantly increased proportionally to mining production. Unfortunately, the increase in mining production has not translated into benefits for affected communities, given that revenues have not been sufficiently invested in the fostering of economic diversification or oriented toward projects that can sustain economic growth and thus improve the population’s socioeconomic status and welfare. The Mining Code revision of 2018 was supposed to tackle these problems and has not yet come to fruition. Moreover, it is a common fact that mining has failed to alleviate poverty in some mineral resource-rich countries of the Sub-Saharan Africa, a region to which the DRC belongs. This work aims at increasing the mining industry involvement in the development of local communities. It analyses the behaviour in the production of copper and cobalt over more than a century and its incidence on the country economic status and the population welfare, as reflected by evolution in the Gross Domestic Product and the Human Development Index. It addresses the issue of mining and the development of local communities and finds that their welfare needs to be improved. The work puts an emphasis on the effective implementation of the new Mining Code and presents a framework for increasing the mining industry involvement in the welfare of affected communities.
A Machine Learning Approach for Identification of Malignant Mesothelioma Etiological Factors in an Imbalanced Dataset
Authors: Alam Talha Mahboob , Shaukat Kamran , Mahboob Haris , Sarwar Muhammad Umer , Iqbal Farhat , Nasir Adeel , Hameed Ibrahim A , Luo Suhuai
Published: March 2021

In today’s world, lung cancer is a significant health burden, and it is one of the most leading causes of death. A leading type of lung cancer is malignant mesothelioma (MM). Most of the MM patients do not show any symptoms. Etiology plays a vital factor in the diagnosis of any disease. Positron emission tomography (PET), magnetic resonance imaging (MRI), biopsies, X-rays and blood tests are essential but costly and invasive MM risk factor identification methods. In this work, we mainly focused on the exploration of the MM risk factors. The identification of mesothelioma symptoms was carried out by utilizing the data of mesothelioma patients. However, the dataset was comprised of both healthy and mesothelioma patients. The dataset is prone to a class imbalance problem in which the number of MM patients significantly less than healthy individuals. To overcome the class imbalance problem, the synthetic minority oversampling technique has been utilized. The association rule mining-based Apriori algorithm has been applied to a preprocessed dataset. Before using the Apriori algorithm, both duplicate and irrelevant attributes were removed. Moreover, the numerical attributes were also classified into nominal attributes and the association rules were generated in the dataset. Our results show that erythrocyte sedimentation rate, asbestos exposure and its duration time, and pleural and serum lactic dehydrogenase ratio are major risk factors of MM. The severe stages of MM can be avoided by earlier identification of risk factors of the disease. The failure of identification of risk factors can lead to increased risk of multiple medical conditions, including cardiovascular diseases, mental distress, diabetes and anemia.
Respiratory Syncytial Virus-Associated Hospitalizations in Children With Neurological Disorders, 2006–2015
Authors: Rose Erica Billig , Dahl Rebecca M , Havers Fiona P , Peacock Georgina , Langley Gayle E
Published: March 2021

Background

We quantified the risk of respiratory syncytial virus (RSV) hospitalizations and severe outcomes among children with neurological disorders.

Methods

We estimated RSV-specific and RSV-associated hospitalization rates using International Classification of Diseases, Ninth Revision (ICD-9) codes from 2 insurance claims IBM MarketScan Research Databases (Commercial and Multi-State Medicaid) from July 2006 through June 2015. For comparison, a simple random sample of 10% of all eligible children was selected to represent the general population. Relative rates (RRs) of RSV hospitalization were calculated by dividing rates for children with neurological disorders by rates for children in the general population by age group and season.

Results

The RSV-specific hospitalization rate for children with any neurological condition was 4.2 (95% confidence interval [CI]: 4.1, 4.4) per 1000 person-years, and the RSV-associated hospitalization rate was 7.0 (95% CI: 6.9, 7.2) per 1000 person-years among children <19 years of age. Among privately insured children, the overall RR of RSV hospitalization in children with neurological disorders compared with the general population was 10.7 (95% CI: 10.0, 11.4) for RSV-specific hospitalization and 11.1 (95% CI: 10.5, 11.7) for RSV-associated hospitalizations. Among children in Medicaid, the RSV-specific hospitalization RR was 6.1 (95% CI: 5.8, 6.5) and the RSV-associated hospitalization RR was 6.4 (95% CI: 6.2, 6.7) compared with the general population.

Conclusions

Our population-based study of children with neurological disorders found that the risk of RSV hospitalization was 6 to 12 times higher among children with neurological disorders than among the general pediatric population. These findings should be considered when determining who should be targeted for current and future RSV interventions.
Impact of low iodine density tumor area ratio on the local control of non-small cell lung cancer through stereotactic body radiotherapy
Authors: Tanaka Mitsuki , Koji Ichise , Fujioka Ichitaro , Sato Mariko , Hirose Katsumi , Kawaguchi Hideo , Hatayama Yoshiomi , Takai Yoshihiro , Tsushima Eiki , Aoki Masahiko
Published: March 2021

Lung cancer with low average iodine density measured via contrast-enhanced computed tomography (CT) using dual-energy CT technology has shown a reduced local control rate after stereotactic body radiotherapy (SBRT). The current study therefore investigated the relationship between low iodine density tumor area and its ratio and local recurrence after SBRT. Dual-energy CT was performed on the day before SBRT initiation, with a low iodine density tumor area being defined as that with an iodine density of <1.81 mg cm–3. The low iodine density tumor area, the ratio between the low iodine density tumor area and the entire tumor, and the local recurrence rate were then determined. No correlation was observed between the low iodine density tumor area and the local recurrence rate. However, tumors with a large low iodine density tumor area ratio showed an increased local recurrence rate, with the prognostic accuracy almost similar to that in previous studies using average iodine densities. Our results therefore suggest that the low iodine density tumor area ratio was a useful prognostic index after SBRT, with an accuracy comparable with that of the average iodine density.
Mutagenic mechanisms of cancer-associated DNA polymerase ϵ alleles
Authors: Herzog Mareike , Alonso-Perez Elisa , Salguero Israel , Warringer Jonas , Adams David J , Jackson Stephen P , Puddu Fabio
Published: March 2021

A single amino acid residue change in the exonuclease domain of human DNA polymerase ϵ, P286R, is associated with the development of colorectal cancers, and has been shown to impart a mutator phenotype. The corresponding Pol ϵ allele in the yeast Saccharomyces cerevisiae (pol2-P301R), was found to drive greater mutagenesis than an entirely exonuclease-deficient Pol ϵ (pol2–4), an unexpected phenotype of ultra-mutagenesis. By studying the impact on mutation frequency, type, replication-strand bias, and sequence context, we show that ultra-mutagenesis is commonly observed in yeast cells carrying a range of cancer-associated Pol ϵ exonuclease domain alleles. Similarities between mutations generated by these alleles and those generated in pol2–4 cells indicate a shared mechanism of mutagenesis that yields a mutation pattern similar to cancer Signature 14. Comparison of POL2 ultra-mutator with pol2-M644G, a mutant in the polymerase domain decreasing Pol ϵ fidelity, revealed unexpected analogies in the sequence context and strand bias of mutations. Analysis of mutational patterns unique to exonuclease domain mutant cells suggests that backtracking of the polymerase, when the mismatched primer end cannot be accommodated in the proofreading domain, results in the observed insertions and T>A mutations in specific sequence contexts.
A functional LSD1 coregulator screen reveals a novel transcriptional regulatory cascade connecting R-loop homeostasis with epigenetic regulation
Authors: Pinter Sabine , Knodel Franziska , Choudalakis Michel , Schnee Philipp , Kroll Carolin , Fuchs Marina , Broehm Alexander , Weirich Sara , Roth Mareike , Eisler Stephan A , Zuber Johannes , Jeltsch Albert , Rathert Philipp
Published: March 2021

The lysine specific demethylase 1 (LSD1) plays a pivotal role in cellular differentiation by regulating the expression of key developmental genes in concert with different coregulatory proteins. This process is impaired in different cancer types and incompletely understood. To comprehensively identify functional coregulators of LSD1, we established a novel tractable fluorescent reporter system to monitor LSD1 activity in living cells. Combining this reporter system with a state-of-the-art multiplexed RNAi screen, we identify the DEAD-box helicase 19A (DDX19A) as a novel coregulator and demonstrate that suppression of Ddx19a results in an increase of R-loops and reduced LSD1-mediated gene silencing. We further show that DDX19A binds to tri-methylated lysine 27 of histone 3 (H3K27me3) and it regulates gene expression through the removal of transcription promoting R-loops. Our results uncover a novel transcriptional regulatory cascade where the downregulation of genes is dependent on the LSD1 mediated demethylation of histone H3 lysine 4 (H3K4). This allows the polycomb repressive complex 2 (PRC2) to methylate H3K27, which serves as a binding site for DDX19A. Finally, the binding of DDX19A leads to the efficient removal of R-loops at active promoters, which further de-represses LSD1 and PRC2, establishing a positive feedback loop leading to a robust repression of the target gene.
Cooperative enterprise at scale: comparative capitalisms and the political economy of ownership
Authors: Spicer Jason
Published: March 2021

Under what conditions do cooperatively owned enterprises scale to stand alongside investor-owned firms? This article measures and attempts to explain large cooperatives’ variable prevalence across high-income capitalist democracies. Controlling for other known social, economic and geographic factors, statistical models confirm that state-mediated institutional arrangements, as operationalized through two comparative capitalism frameworks (Varieties of Capitalism and Welfare Regimes), are a significant factor in this variation. Cooperatives scale in a manner that complements arrangements in coordinated market economies, while exhibiting institutional incongruencies with those of liberal market economies and residual welfare states. Public policies which have variously enhanced or inhibited cooperatives’ ability to coordinate to scale are compared across four case countries (United States, France, Finland and New Zealand). Policy differences are shown to reflect the joint effect of state-mediated institutional arrangements alongside other control variables. They reveal how states privilege some ownership forms over others, suggesting a distinct political economy of ownership.
The comparison of medial longitudinal arch development in normal feet and flexible flatfeet in preschool children with an 18-month follow-up: a retrospective case-control study
Authors: Farahmand Behshid , Pourhoseingholi Ensieh , Bagheri Azam
Published: March 2021

Background:

Flexible flatfoot is a major concern for parents of preschool children. Although the medial longitudinal arch (MLA) has significant development during the growth of a child, flexible flatfoot usually does not need treatment. However, the time and process of MLA changes are controversial among researchers. The aim of this study was to compare MLA development in preschool children with normal feet and with flexible flatfoot.

Methods:

Sixty preschool children (36 girls and 24 boys) with normal feet and 60 preschool children (36 girls and 24 boys) with flexible flatfoot participated in this study. The arch index (AI) was obtained from static footprints.

Results:

According to this study, the mean values of AI in the flatfoot and control groups showed significant difference.

Conclusions:

The results of this study indicated that the medial longitudinal arch development was lower in preschool children with flexible flatfoot than in the control group. This lower development was shown by higher AI.

Level of Evidence:

Level III.