bluuebunny/crossref_metadata_2025 huggingface dataset:
Bibliometric Analysis of Research on the Water and Sediment Environment in the Middle  Lower Changjiang River Basin
Authors: Guo Ziyang , Wang Dianchang , Zhang Lei , Huang Hai , Wang Dayu
Published: March 2021

To elucidate research progress, hotspots, and trends regarding the water and sediment environment in the Changjiang River Basin, a bibliometric analysis of research published on the water and sediment in the middle-lower reaches of the Changjiang River, from 1991 to 2020, was conducted, according to the Web of Science Core database. With regard to the number of papers, distribution of research institutions, tracking of research hotspots, related disciplines, highly cited literature, etc., a comprehensive statistical analysis was conducted to investigate the research characteristics, research status, and development trends of the water & sediment environment in the middle-lower section of the Changjiang River. Combined with the latest trends in water and sediment environment research, important future research directions were investigated. The results indicated that, among the literature, the Chinese Academy of Sciences(CAS) was the largest contributor to study on the water and sediment environment of the Changjiang River, followed by universities along the Changjiang River. Chinese scientific research institutes paid the most attention to changes in the water and sediment environment of the Changjiang River and cooperated on an international level with other countries. From the perspective of discipline distribution, the number of papers on ecological environment was the highest, followed by that on geological environment, water resources, engineering, and oceanography. The amount of research conducted on water and sediment transport, riverbed change, water pollution, and other issues was relatively high. According to the highly cited literature, water contamination and sediment were the main concerns. Combined with high-frequency keywords — and by consulting the relevant literature — this paper presented the hot spots of the water and sediment environment in the middle-lower reaches of the Changjiang River. It is determined that the implementation of water conservancy projects in the upper reaches of the Changjiang River has changed the path, release mechanism, and role of phosphorus, as well as the ecological environment of the Changjiang River Basin and its estuary. Change of phosphorus flux and its effect on environment are one of the most important directions for future water and sediment environment research.
A Simplified Calculation Formula for Horizontal Bearing Capacity of Micro-piles Foundation
Authors: Liu Fuhai , Hou Zhongwei , Kong Fanli , Zhang Jing , Zu Jianquan , Li Yangyang , Zhang Ying , Feng Kai , Zhang Mingxing
Published: March 2021

When m value is above 21, If the horizontal load has not reached the design value of the theoretical ultimate bearing capacity, the foundation pile will first appear bending failure. That is to say, when m value is greater than 21, the horizontal bearing capacity of pile group bearing platform foundation begins to depend on the bending strength of pile itself. The ultimate horizontal bearing capacity of pile group bearing platform foundation in actual engineering has been difficult to reach the ideal design value。 When the value of M is less than 21, the actual horizontal ultimate bearing capacity is consistent with the theoretical calculation, when the m value is greater than 21, the actual horizontal ultimate bearing capacity can be calculated according to the simplified formula proposed in this paper.
The Influence of Styrene/butadiene Ratio on the Self-assembly Behavior of SBS Modified Asphalt
Authors: Yu Caihua , Hu Kui , Chen Yujing , Li Qi , Zhang Taoli , Chen Guixiang
Published: March 2021

This work using molecular dynamic simulation to explore the micro mechanism of Styrene-butadiene-styrene (SBS) with light components (aromatics and saturates). The results indicate that the adsorption area decrease with the increase of S/B ratio. And with the increase of temperature, the adsorption area first increased and then decreased. Rutting factor experiments show that the rutting factor gradually decreases with increasing temperature and decreases with increasing S/B ratio, which is consistent with the findings of molecular dynamics simulations.
Data Prediction Model Based on LSTM Neural Network in Bridge Health Monitoring System
Authors: Xiao Shihui , Qiao Shengfang , Chen Hang , Liu Xi , Li Yue , Tang Mengxiong , Hu Hesong , Li Gaotang
Published: March 2021

The abnormal value was common in bridge health monitoring system. The prediction model based on LSTM neural network in bridge health monitoring system was studied in this paper. The modeling process was discussed about LSTM neural network model. The LSTM neural network model was also used to analysis the actual data in bridge. The results indicated that the prediction accuracy of LSTM model was high. Thus, the LSTM neural network could be used to analyze and predict data in bridge monitoring system.
Application of Dual-photothermal Imaging Technology in Leakage Detection of a Large-Scale Pool Structure
Authors: Li Weiguang , Pan Yi , Wang Shudong , Deng Haidong , Bian Decun
Published: March 2021

The leakage of reinforced concrete has been a key factor to affect the quality of waterproof structures, and the leakage detection has been the focus and difficulty to be considered in waterproof structures. Aim at this situation, based on a practical project as a case, an infrared thermal imaging nondestructive detection (ITID) technology was applied to the leakage detection of a reinforced concrete pool structure (RCPS) in this study. The dual-light infrared thermal imager (ITI), based on unmanned aerial vehicle (UAV) platform, was used to detect the leakage of external wall of the structure. The effectiveness and reliability of leakage detection were analyzed and verified for ITID technology applied into RCPS. Results show a good detection effect is obtained, and a new choice for detecting the leakage of RCPS is proposed.
Analysis of Seepage Law of Precipitation in Horizontal Wells with Low Permeability Formation
Authors: He Jibin , Li Guowei , Yu Li
Published: March 2021

Based on the euler model of multiphase flow in FLUENT and standard k-epsilon model, considering the influence of negative pressure inlet position (pump position) and nitial water head height (water head thickness), a 3d Pipe flow-seepage coupling pumping model for horizontal wells is built and calculated iteratively. On this basis, a detailed study is carried out on how to improve the fluid collection efficiency of horizontal wells. The results show that: (1) the fluid velocity at the negative pressure inlet increases as the pressure inlet location decreases from the top of the horizontal well to the heel, in the process of the depth change from heel to toe in the horizontal section, the fluid velocity at the negative pressure inlet increases first and then decreases; (2) the pressure increases in a certain proportion with the increase of the initial water head (that is, the thickness of water layer), and then the efficiency of horizontal well is improved; (3) Combined with numerical simulation analysis, in the model experiment, fluid flow causes uneven distribution of sand around the horizontal well, leading to a certain degree of pore annihilation, which causes pressure fluctuation along the horizontal well and reduces the production efficiency.
Application Prospect of Energy Cyber-Physical Systems in Operation Optimizing of Wet Flue Gas Desulfurization
Authors: Yang Yonglong , Su Qiufeng , Wang Jinxiu , Liu Xiaomeng , Zhang Zhizhong , Zhu Yue
Published: March 2021

Limestone-gypsum WFGD is the most widely used to control SO2 emission of coal-fired power plants in China. Although SO2 and a variety of pollutants can be efficiently removed by WFGD. The WFGD has great potential in controlling SO2 emissions and saving energy and reducing consumption due to the influence of operating conditions of coal-fired power plants after ultra-low emissions. In order to explore and analyse the feasibility of e-CPSs in operation optimizing of WFGD. The concept of e-CPSs is introduced systematically. Then the main building blocks of e-CPSs applied to WFGD are described in detail. The existing problems of WFGD are analysed. The operation optimizing method of WFGD based on e-CPSs is introduced. E-CPSs as a new more efficient and reliable intelligent control system. The prospect and benefit of its application in WFGD of coal-fired power plant are discussed in this paper.
Complexity and specifics of elimination of emergency spills of light hydrocarbons in offshore fields
Authors: Bogatyreva E V , Vorsina G D
Published: March 2021

This paper describes the problem and complexity of elimination of gas condensate spill in non-shelf fields. The problems and specifics of emergency gas condensate spill managing are identified. They demonstrate a need for development of a special spill response strategy. The gas condensate spill simulation was performed using the PISCES II software. A summary table of results is presented, physical and chemical properties of gas condensate were analyzed. Relevant conclusions have been drawn.
Methodological bases for evaluating the effectiveness of Arctic field development
Authors: Plenkina V V , Osinovskay I V , Mamaeva A A
Published: March 2021

The article reveals the methodological foundations for a comprehensive assessment of the effectiveness of the development of deposits in the Arctic shelf. On the one hand, the assessment assumes, based on the use of a multicriteria approach, ranking the priority of field development, on the other hand, the formation on its basis of a strategic model for managing the oil and gas complex, taking into account the development of Arctic fields. The authors emphasize the advisability of conducting a comprehensive assessment in relation to the development of the respective region. The list of indicators considered by the authors, which forms the basis of the multicriteria model, is open and can be adapted to the purposes of the assessment, as well as the scope of the results obtained. The methodological approach proposed by the authors can serve as an express assessment of the effectiveness of the development of fields in the Arctic. The classic matrix of the Boston Consulting Group, which takes into account the level of efficiency from the development of the Arctic shelf fields, has been chosen as a tool for forming a strategic management model.
Studying the factors affecting the navigation duration along the Northern Sea Route
Authors: Tezikov Aleksandr , Ol’Khovik Evgeniy
Published: March 2021

The problems of year-round navigation in the water area of the Northern Sea Route are considered. The study results are obtained at the Admiral Makarov State University of Maritime and Inland Shipping within the framework of the “Hydrographic support of the Northern Sea Route” scientific school in two main interrelated directions. The first direction is devoted to the study of the main natural - climatic and navigational - hydrographic factors affecting the navigation conditions. The second direction is focused on the collection and analysis of statistical information on the ships movement parameters and on the substantiation of the year-round navigation possibility in all waters of the Arctic Seas and Polar waters. The main trends of changes in the fleet structure, the conditions of ships navigation and the development of the shipping routes network in the Arctic seas over the past ten years are noted. Particular attention is paid to the studies results related to the development of the shipping routes network on the eastern sector of the Northern Sea Route and the prospects for year-round navigation of ships in the Laptev and East Siberian Seas.
Recent trends of human presence in the Arctic area (as exemplified by Murmansk region, Russia)
Authors: Belevskikh Tatyana , Ivanova Medeya
Published: March 2021

Arctic area is a particularly extreme territory in terms of natural and climatic conditions for life and human activities. The major reason for a significant part of the Arctic population to permanently reside here has always been and will probably be the economic practices of society associated with the use of the Arctic territorial resources. Over the past twenty years, the population of the Russian Arctic zone has decreased by half, despite the growing trend of this indicator worldwide. In this paper, the authors connect the population dynamics in the Arctic regions of the Russian Federation with the employment indicators, despite the measures currently taken to actualize the importance of human presence in the Arctic at the state level. Using the example of the Murmansk region, a constituent entity of the Russian Federation, fully located within the Arctic zone, the authors identified the leading trends in employment of the Arctic population as well as the “leading employers” of the Arctic labor market which define the parameters of regional employment. Based on the analysis of regional statistical data, the authors make a conclusion about the prospects for population changes in the Arctic zone of the Russian Federation.
Migration of people: pros and cons
Authors: Sergievskaya Nataly
Published: March 2021

The article reviews the causes of migration of people, influencing factors, types of migration, examines the positive and negative impacts of migration on the home countries of people and on their host countries. It presents statistical data related to migration of people in various countries. The authors examines the advantages and disadvantages of migration of people at following three levels: initial home countries, the host countries and people themselves. According to the author, the groups of migrants can be divided into the following 4 blocks based on the level of migration: 1.people go abroad planning to come back and they return to their homeland; 2.people go abroad planning to come back, but they do not return; 3.people go abroad not planning to come back, but they return to their homeland; 4.people go abroad not planning to return and stay there forever. The author proposed a conceptual model of migration of people and describes possible related scenarios, such as: win-win-win scenario; win-win-lose scenario; win – lose-lose scenario; lose-win-win scenario; lose-lose-win scenario; win-lose-win scenario; lose-lose-lose scenario.
DEPENDENCE OF THE POLARITY AND SURFACE ACTIVITY OF PHOSPHOLIPID MOLECULES ON THE COMPOSITION AND SPATIAL STRUCTURE OF THEIR MOLECULES
Authors: Marchenko Lyudmila , Bokovikova Tatyana , Rudik Victoria
Published: March 2021

The problems of the Arctic economy are especially relevant today and require an urgent solution. The main factor in solving these problems is a human being, a person (individual) whose health is the key to his full-fledged creative work. Preventive methods of combating diseases, an integral part of which is the creation of food products with dietary, therapeutic and preventive properties, should be of the greatest importance in programs to improve and maintain a healthy lifestyle of the population. Products manufactured by the fat and oil industry make up a significant part of the traditional diet of the Russian population. The authors have investigated and proved that the lower value of the dipole moments of phospholipids derived from oils of modern types of sunflower justifies the lower hydration of oils, and, therefore, the need to select a hydrating agent, taking into account its polarizing ability. The findings will make it possible to contribute to protection of the health of a person living in extreme conditions.
The model of an online digital competencies development system for the management personnel of the Arctic region
Authors: Abrahamyan Gennady , Atayan Anush , Sharabaeva Lubov , Gureva Tatiana
Published: March 2021

The article presents a model of online system devised for the development of digital competencies of management personnel in the Arctic region. The model includes a description of the means and technologies allowing implementation of distance learning processes, justification of choice of digital platforms used, structure of electronic educational resources, and methodology of analysis of students’ performance based on the “digital footprint” technology. The structure of electronic educational resources is expected to provide an opportunity of use in various modes and forms of management training, basic and additional professional education, as well as online exchange of positive professional experience between the leaders of the Arctic regions. This approach us e-learning tools in the education shall increase the interest and involvement participants in various types of cognitive activities. The use of Microsoft Office 365 solution for education allows to integrate LMS Moodle with Teams communication application, which supports interactive format of communication. And the OneDrive cloud service shall allow to ensure secure storage of electronic documents and to organize online project work in teams. The statistical data of students’ performance is collected with the use of “digital footprint” technology and analyzed in order to obtain qualitative characteristics of online education process. The expected outcomes of learning will be related to the consumers’ requests. The proposed model of the training system for managers is expected to allow the practical implementation of the Life Long Learning concept, by drawing multi-component individual educational and professional development trajectories in the Arctic region subjects.
Essential, legal and environmental aspects of sustainable development of Arctic tourism
Authors: Kuchumov Arthur , Pecheritsa Elena , Chaikovskaya Alexandra , Zhilyaeva Irina
Published: March 2021

The article examines some issues of sustainable development of Arctic tourism in the Russian Federation. The authors make an attempt to formulate the concept of “Arctic tourism”. They analyze existing regulatory framework for the development of Arctic tourism, consider categories and types of Arctic travel on current examples, and identify problems of sustainable Arctic tourism development. The conclusion is that development of mass tourism is not mandatory, as tourism in this region should be developed purely as an exclusive one, because it is necessary to regulate visits to protected natural areas, since otherwise there arise risks of losing the pristine nature of the Arctic.
Experimental study of the effect on soil erosion of using tiny gravel as bedding for defective sewer pipes
Authors: Khudhair H. H , Basim K N , Al-Baidhani J H
Published: March 2021

The erosion of soil is the most influential factor contributing to the creation of sinkholes in urban areas. Soil degradation often takes place due to failures in sewer pipelines, when water flows from and to the adjacent soil through pipes defects. Soil deficiency surrounding faulty stormwater sewer pipes has been attributed to various reasons, including water infiltration and exfiltration volume or discharge, crack size, relative density, water heads, and the number of cracks. This paper focuses on the effect of using tiny gravel media as a protective layer to reduce the processes of soil erosion due to the faults in the wastewater system, which is done by means of a comparison of erosion mechanisms observed when using a protective tiny gravel layer and without. A local sandy soil was used, obtained from the neighbourhoods near the city centre in the Karbala governorate. Sixteen tests, separated into two groups, were performed to identify the differences in outcome between the two statuses, with a matrix of various influential factors to which erosion has been attributed used across the experiments. The outcomes demonstrated that using a tiny gravel layer as a protective bedding layer has an excellent effect on impeding soil erosion processes and, in particular, tremendous efficiency in reducing cavity formation of up to 95.4%. Furthermore, the findings showed an 18.25 times decrease in the total eroded soil, while the settlement of soil surface showed a 26.35 times decrease, allowing higher internal stability and reduced sewer pipe path deformation.
Functional Reuse of Contemporary Residential Houses to Multiple Functions in Baghdad : an investigation of the most widespread functions, using Sulaikh 600 as a case study
Authors: Ali N H , Alkindy S K
Published: March 2021

Functional reuse of contemporary residential houses for multiple functions has been recognised, as an obvious issue in several residential neighbourhoods in Iraq in general and Baghdad in particular. This issue is currently becoming more prominent for several economic, social, and other reasons. Many previous studies have dealt with the concept of reuse to preserve residential houses with historical value, and this concept has been developed in several contemporary residential houses based on the desire of their owners to preserve them via economic investment. this paper thus highlights the growing importance of issue. The research problem was identified by determining the impact of this issue the urban context to facilitate the design of levels for contemporary residential buildings based on a diagnosis and evaluation methodology. The aim of this paper thus to the most prevalent functions of such reuse and their positive and negative effects on the urban context and local design levels. The research adopted a descriptive and analytical method to examine a selected sample of the residential houses, (with eight examples taken from one Baghdad neighbourhoods (Sulaikh 600) which has a history of functional reuse of residential houses for multiple functions. This research found that the functional reuse of contemporary residential houses as educational locations (schools and kindergartens) is the most prevalent type due to its positive effects including compensation for the shortage of government institutions, outweighing the negative effects of increasing the number of users and placing heavier pressure on the infrastructure services of the residential area, which may be functionally unsuitable for non-residential functions. This supports the development of a periodic assessment and diagnosis of this issue by the concerned authorities to preserve residential neighbourhoods to meet urban and design standards by offering better provision for needs currently met in this way. Based on the large scale of the problem, the research also highlights each sample in an attempt to diagnose the case exclusively.
Shear Performance of Hybrid Concrete Deep Beams of Trapezoidal Section
Authors: Sada Majid Jafar , Resan Sa’ad Fahad
Published: March 2021

The structural behaviour of hybrid reinforced concrete beams of trapezoidal section was investigated in this work. The main aim of study was to investigate the interaction effect of hybrid concrete compressive strength–section geometry variations on beam strength characteristics. The experimental programme included fourteen simply supported reinforced concrete deep beams being prepared and examined under a four-point load setting protocol. All specimens were of 1,000 mm length and of equal cross-sectional area. The specimens were divided into groups according to section shape variations and hybrid compressive strength considerations. Various concrete compressive strengths (70, 50, and 25) MPa were considered, and three different trapezoidal geometries of different alignment side angles (75°, 80°, and 85°) were also adopted, along with two steel rebar ratios (0.008617 and 0.01508). Generally, the experimental results showed that the shear strength capacity increased with increases in the area of high-strength concrete in the compression zone in increments, with improvements ranging from 3.66% to 8.63% as compared to reference specimens of uniform section (rectangular section); the diagonal crack load decreased, however. It was also observed that the hybrid concrete created high ductile behaviour, and the significant failure mode was shear mode without slippage of the hybrid concrete layers. A comparison of results with the hybrid strength reduction index (Ψ=f’cb/f’ct) showed that as Ψ decreased from 0.714 to 0.357, the average rating varied between 1.15 and 1.22 with respect to rectangular specimens and from 1.07 to 1.13 with respect to trapezoidal sections of uniform strength. An optimum alignment side angle for trapezoidal configuration also appears to be indicated, with the best results for all hybrid strength-trapezoidal sections in specimens where Ө=80°.
Perception Of Architectural Output: The Presence Of Architecture In The Presence Of a Pandemic
Authors: Kadhim Ibrahim Jawad , Ubaid Wasan Jawad
Published: March 2021

The importance of the fourth dimension in architecture is based on its use to determine the effectiveness and structure of four-dimensional space through perception; how people livesin architecture and move within spaces is affected by the ways their senses become accustomed to what they see and perceive. New intellectual responses are generated by both new formations and circumstances, generating the research problem focused on the role of architecture with respect to recognising the current pandemic and its effects on architectural production. The research goal was thus to achieve a new perception of architecture by adding the fourth dimension of time as one of the component dimensions within the system of change that architecture must develop in response to the pandemic; this can be achieved by creating broader horizons within classic theories in an attempt to formularise architectural products that adopt the fourth dimension to address issues arising from the pandemic. The research method included inductive, analytical, and interpretive approaches, examining various theories and concepts to arrive at a set of values, and the results were a set of mental concepts that describe an architectural perception of the pandemic, based on interaction, which provide a knowledge base for developing awareness of the pandemic through architecture.
Physically and chemically treating sulphurous water in western of Iraq
Authors: Khudair M. Y. , Al-Hadithi Y.K.
Published: March 2021

The agricultural sector in Iraq is one of the country’s most water-consuming sectors. Recent shortages of fresh water have made it necessary to utilise treated water, whether sewage water, sulphurous water, or industrial water, for such purposes to preserve the available water resources. A laboratory experiment was therefore conducted to study the effects of different physical and chemical treatments on sulphurous water intended for irrigation. The chemical treatments used were bentonite, nitric acid, activated carbon, and manganese oxide, while the physical treatment process examined was ventilation of various durations. The results showed that all treatments led to a reduction in the concentrations of iron, hydrogen sulphide, and sodium in the treated water, and that all methods of treatment and concentrations led to the reduction of SAR in the treated water. Some treatments led to an increase in the electrical conductivity, namely bentonite and nitric acid, while the other treatments led to lower electrical conductivity. All treatments and concentrations led to an increase in the concentration of magnesium in the water compared to that in the untreated water, which is considered a positive indicator.
Evaluating Porous Pavement for the Mitigation of Stormwater Impacts
Authors: Al-Busaltan Shakir , Kadhim Mustafa Amoori , Nile Basim K , Alshama Ghofran A.
Published: March 2021

Urban stormwater management is one of the biggest challenges facing modern cities. The current stormwater networks are likely to be insufficient under continuous urbanisation and the development of residential areas in addition to increases in rainfall intensity, especially in areas with relatively high slopes, which may thus be subject to flooding. This study aimed to mitigate the overflow rate of the selected case study area using a pervious inlets pavement technique based on porous asphalt concrete pavements with a reservoir layer. The current stormwater network system of the Al-Yarmouk quarter (located at the centre of Karbala City, Iraq) was evaluated by exposing it in simulation to a rainfall intensity equivalent to the 5-year return period and applying storm and sanitary analysis (SSA) and GIS software. The simulation results showed that constructing 50% of the road surface area (5% of the total studied area) with porous asphalt concrete with air voids of about 20% and variable reservoir thicknesses, could reduce water runoff entering the network significantly. Moreover, placing 240 mm, 328 mm and 400 mm of No.75 aggregate layer within reservoir depths would result in further mitigations of surface runoff quantity by about 15%, 30%, and 45%, respectively. A reservoir depth of 240 mm was found to reduce flooding quantities and times by about 71% and 18.29%, respectively, while creating a 328 mm reservoir depth under the porous asphalt results in quantity and time reductions of about 98.5% and 81%, respectively. No surface flooding was observed when reservoir depth was changed to 400 mm.
Experimental and finite element analysis of mechanical behavior of concrete damaged by Alkali Aggregate Reaction (AAR) and repaired with CFRP Layers
Authors: Kadhim Roaa A , Al-Taie Rania S , Al-Mahaidi Prof Riadh
Published: March 2021

Concrete structures is affected by a deleterious reaction, which is known as Alkali Aggregate Reaction (AAR). AAR can be defined as a chemical reaction between the alkali content in the pore water solution of the cement paste and reactive forms of silica hold in the aggregate. This internal reaction produces expansion and cracking in concrete, which can lead to loss of strength and stiffness. Carbon fiber-reinforced polymer (CFRP) is one of the methods used to suppress further AAR expansion and rehabilitate and support damaged concrete structures. In this research, thirty-six cylindrical specimens were fabricated from non-reactive and reactive concrete, which contained fused silica as 7.5%. In addition, twelve concrete prisms were fabricated from non-reactive and reactive concrete in which three different percentages of fused silica are used, 5%, 7.5% and 10% of the total aggregate. This paper investigates the impact of AAR expansion on the physical and mechanical properties of concrete. It also reports the effective use of one and two CFRP layers on wrapping concrete cylinders. The experimental results show that CFRP is effective in confining damaged concrete by AAR and results in concrete strength enhancement of up to 560%. A comparison of finite element (FE) analysis using ATENA 3D software and the experimental results indicated that FE analysis is capable of modelling the behavior of AAR-damaged concrete repaired with CFRP.
Study of Various Techniques for Estimating the Generalised Extreme Value Distribution Parameters
Authors: Hossain Iqbal , Imteaz Monzur , Khastagir Anirban
Published: March 2021

Generalised extreme value distribution (GEVD) remains the commonly employed technique for investigating the probability of occurrence of extreme events for given recurrence of intervals. However, the application of the GEV distribution requires the estimation of its three parameters. There are different methods presented in the literature to determine the parameters of the GEVD. Different methods have been adopted by different researchers in determining the three parameters. This paper investigates the comparison of the commonly used methods to estimate the GEVD parameters. The maximum likelihood estimation (MLE), generalised maximum likelihood estimation (GMLE) and L-moments methods were considered in this study. The analysis was performed using the monthly extreme rainfall of Tasmania, Australia. The GEVD was fitted to four different data sets using the three parameters estimation techniques. The outcomes of the analysis suggest that parameters estimation techniques have negligible impact on the magnitude of the parameters. However, length of the data series has minor impact on the parameters value of different parameters estimation techniques.
Efficient environmental architectural design for educational buildings in Iraq: An environmental study of the computer engineering building in the University of Technology, Iraq
Authors: Hameed Haddad Ahmed Talib , Abbas Kais Abdulhusein , Challoob Ahmed Abed
Published: March 2021

The topic of the thermal environment of architectural buildings is important in current architectural design. This research thus discusses the state of the computer engineering building in the University of Technology of Baghdad through the lens of climate elements and the principles of sustainability with the aim of achieving increased comfort for those occupying this building during office hours.

The research thus proposes several solutions including creating a mask for the building, as well as making decorations commensurate with the goal that highlight elements of Arab Islamic architecture while also creating shadows that may decrease direct solar radiation. Further ideas include tilting the glass inwards in some windows, and replacing the capon panels with concrete structures that separate then from the building to create a buffer distance, as well as shifting room locations from one place to another, and adding afforestation around the building in a thoughtful manner.
Failure evaluation of composite concrete using an acoustic emissions technique
Authors: Al-Jumaili Safaa Kh , Jassim Ahmad K , Ali Dhia C
Published: March 2021

One major problem with concrete is high brittleness with low tensile strength and strain capacity, which can cause sudden failure. Structural Health Monitoring (SHM) is thus very important to detect cracks in initial stages to avoid catastrophic failure. In this research, an acoustic emissions (AE) technique was applied to enable SHM to detect cracks and predict the failure of composite concrete. This physical non-destructive testing process utilises transient elastic waves caused by the rapid release of energy from a localised source within a structure. A low-frequency acoustic emission system was thus tested for economical monitoring of the damage to reinforced composite cubic concrete under compression. Specimens of standard size (150 x 150 x 150 mm) were produced without and with polyamide reinforcement bars. The compression strength of the cubic concrete was then tested according to BS EN 12390-1. Prior to testing, a low-cost single piezoelectric wafer active sensor was applied to the centre of one side of each specimen, which was then connected to a PC’s sound card. Data was successfully recorded using sensors and the real-time of the applied load was recorded using a separate data logger. Traditional AE signal parameters were extracted and used for damage evaluation. The results indicated that the AE system was capable of detecting cracks in representative structures to final failure. Signal amplitude with load versus time showed an increase in AE activity and energy approaching the end of the test, while commutative hits could be used to distinguish between stable and unstable loading stages. The system also detected the initiation of the final failure stage at 72.6% and 83% of the failure load of specimens without and with polyamide reinforcement bars, respectively.
Evaluating the mechanical properties of thin asphalt overlay incorporating reed ash
Authors: Abduljabbar Nadia , Al-Busaltan Shakir , Dulaimi Anmar
Published: March 2021

Thin Asphalt Overlay (TAO) is a preservation maintenance technique that has been shown to overcome shortcomings in the functional properties of surface pavement layers. Although TAO is not a structural layer, its application sustains the pavement’s structural strength and increases its lifespan, which is a valuable effect for the paving industry. Due to recent realisation of the limits of natural resources and the high cost of raw materials, the paving industry has also developed a secondary target of incorporating waste materials as an alternative to conventional raw materials, both to reduce environmental pollution and minimise costs, in such applications. This study focuses on evaluating the effect of using reed ash (RA) in this manner on the mechanical properties of TAO. The control TAO mixture was densely graded, with a 9.5 mm nominal maximum aggregate size (NMAS) utilising a 40/50 asphalt binder grade. Three percentages of RA were incorporated, 6%, 12% and 18%, to produce modified asphalt binder. To verify the effect of this material on cracking behaviours, resistance to permanent deformation of TAO, indirect tensile strength, creep compliance, and wheel track tests were carried out on both control and modified asphalt mixtures. The results showed a significant enhancement in the performance of TAO modified with 6% RA as compared to the control mixture, although the very high dosage of 18% reduced the performance of the relevant TAO mixtures. This study thus indicates that using this waste material can offer an alternative solution for asphalt cement modification, increasing sustainability, if dosages are carefully controlled.
Analysis of the Euphrates River’s movement within Al-Hindiya, Karbala, relative to steady flow conditions using the HEC-RAS model
Authors: Saleh Layla Ali Mohammed , Majeed Sumayah Amal Al-Din , Algretawee Hayder H.
Published: March 2021

The steady flow condition is considered to be the dominant case for multiple rivers around the world. River studies thus necessarily focus on this condition, including those in Iraq, which has two rivers running from north to the south. In this study, the HEC–RAS program was applied to steady flow analysis of the Euphrates River within Al-Hindiya in Karbala. The case study was executed for the whole city of Al-Hindiya by selecting 12 km length of the river and dividing it into 30 sections. Field data for 2019 was thus used to develop three profiles for discharge at minimum, normal, and maximum magnitudes, which were 90 m3/sec, 250 m3/sec, and 445 m3/sec, respectively. The results showed that the maximum variation ratios in velocity between sections were 80%, 70%, and 72% for the minimum, normal, and maximum profiles, respectively, with the variation ratios in water level between reach ends being 4%, 6%, and 5% and the slopes of energy grade lines were about 0.009%, 0.015%, and 0.013% for the three profiles respectively. In addition, the regression analysis of the results revealed that the relative energy losses between any two adjacent sections are linked strongly to the relative change in water level for the normal and minimum profiles, with coefficients of determination R2= 0.88 and 0.96 for these profiles, respectively; however, for maximum discharge, the relative energy losses were related to the relative change in both velocity head and water level, withR2=0.94.
Effects of linear modification on the performance of finite length journal bearings
Authors: Al-Mosawy H A , Jamali H U , Tolephih M H
Published: March 2021

Journal bearings are widely used in industry due to their favourable characteristics such as relatively low cost of manufacturing and maintenance, high load carrying capacity, and useful dynamic characteristics for rotor systems. Journal bearing misalignment, however, may have negative consequences for the general performance of this type of bearing. Misalignment commonly occurs due to errors in manufacturing tolerances, installation errors, wear, shaft deflection, and asymmetrical loading of systems. This paper presents a solution for hydrodynamic problems in journal bearings of finite length based on a 3D misalignment model and linear modification of the bearing profile to reduce the effect of misalignment on the characteristics of the journal bearing. The results showed that linear modification of misaligned journal bearings reduces the maximum pressure and improves the level of film thickness; additionally, the dynamic characteristics of the journal bearing are also improved by such linear profile modification.
Solar cooling modelling utilising for cooling agro-products cold store under Rwandan environmental conditions
Authors: Alammar A A , Rezk A , Alaswad A , Ruhumuliza J , Gasana Q G
Published: March 2021

Solar-driven cooling systems can be considered as a sustainable solution for the weak cold chain. Transient Simulation System (TRNSYS) offers component-based 0D modelling capability of different engineering systems. TRNSYS has been employed to model a year-round performance of a PV solar-driven electric chiller to meet the cooling demand of post-harvested foodstuffs under Rwandan metrological data. Various PV module sizes and batteries storage capacities have been investigated to examine their effect on the solar energy fraction powering the electric chiller to maintain the room at the desired temperature. In addition, two different arrangements of chilled water loop, namely one-loop with 3 KW chiller capacity and two-loops with 6 KW chiller capacity have been compared to investigate their effect on the chiller performance and solar fraction. Results revealed that the later arrangement exhibits a higher solar fraction compared to one loop despite the addition of another pump. For 35 PV modules, the two-loops arrangement requires 42 kWh battery capacity to provide about 90% solar fraction, while one-loop needs 66 kWh to deliver the same solar fraction. Accordingly, the battery storage capacity is reduced by a factor of 0.36 which justifies the increase in the chiller capacity from 3 KW to 6 KW. This study provides a selection map to choose between the number of PV panels and batteries capacity required to power the chiller and meet the cooling load.
A Review of Solar Energy Harvesting Utilising a Photovoltaic–Thermoelectric Integrated Hybrid System
Authors: Aljibory M W , Hashim H T , Abbas W N
Published: March 2021

Solar energy has the potential to be converted from light to electricity; however, solar cells can only utilise the short-wavelength portion of the solar spectrum to do this directly. In contrast, long-wavelength portions of the spectrum can be converted to heat inside solar cells, and such heat can be harvested and converted into electricity by means of a thermoelectric generator (TEG). The integration of photovoltaic and thermoelectric hybrid systems has thus attracted a great deal of attention due to these offering the ability to utilise solar energy across the full spectrum, including light and heat. This paper reviews the possibility of integrating photovoltaic (PV) and thermoelectric generators (TEG) in a PV-TEG hybrid system based on examining recent efforts in the field of PV-TEG creation. It also examines the efficiency improvement in PV-TEGs and their applications in recent years, offering a valuable guide for researchers and designers.
Optimization-based Component Sizing Method for Electrified Heavy-Duty Powertrain Concepts
Authors: Roth D. , Habermehl C. , Jacobs G. , Neumann S. , Juretzki B. , Bayer D.
Published: March 2021

The demand for battery-powered, exhaust emission-free mobile machinery is increasing. However, the high energy requirements of mobile machines result in large, heavy and expensive battery storage systems. Driven by continuously decreasing but still fairly high battery costs battery costs, the efficiency of the drive system is becoming the focus of development activities, even in an industry where robustness, service lifetime, productivity and power density have been the driving factors up to now. Interactions between topology, component sizing, and control strategy require a system-level approach for the development of drive systems. In this paper, a novel optimization-based sizing method for electrified heavy-duty powertrain concepts is presented and applied to subsystems of a wheeled excavator. Scalable component cost and efficiency models are used in a system simulation to calculate objective function values for a multi-objective optimization. The result of the optimization, a trade-off between energy consumption and costs provides the OEM with a decision support in the development process. The modular structure of the approach allows a subsequent extension of the design parameter space as well as the detailing of the models used.
Tribological analysis of the plain bearings in an external gear pump
Authors: Brinkmann Lars , Kock Stefan , Lang Jochen , Knoll Gunter
Published: March 2021

Tribological loads in the plain bearings of external gear pumps are influenced by system-specific parameters (e.g. elasticity of the components, micro-geometry and manufacturing tolerances) and the operating point (rotation speed, operating pressure and temperature of the pressure medium). Due to the pressure build-up in the tooth chambers, fluctuating radial forces are acting on the gear shafts and lead to complex deformations of the bearing bushings and the housing. These deformations have an influence on the tribological loads in the plain bearings. To decrease tribological loads and failure rates, it is possible to modify the plain bearings in terms of their micro-geometry (e.g. clearance and contours) or to take constructive measures on the overall system (e.g. on the bearing bushings). Therefore, it is necessary to understand the influences of external loads, elastic environment and micro-geometry on the tribological loads in the plain bearings. This paper describes the first steps to understand these interactions by building up a simulation model of a specific external gear pump using the MBS/EHD-tool FIRST developed by IST [1]. The focus is to evaluate the required modeling depth regarding the consideration of an elastic housing.
Influences on the lubricant supply of grease lubricated gears
Authors: Siewerin B J , Winkler K J , Tobie T , Stahl K
Published: March 2021

Greases have a variety of advantages when special operating conditions apply. Mainly related to large, slow-running gear drives such as used in heavy industry applications, grease lubrication can also be the preferred solution for small, fast running gear drives. Conse-quently, the calculation of the wear service life within the gear design process is essential. Due to their flowing properties, there is a danger of losing the lubrication supply depending on the operating conditions, boundary conditions and grease properties. While a circulating lubricant ensures a continuous lubricant supply to the gear mesh, channeling includes the risk of starved lubrication and consequentially, even a discontinuation of the lubricating film that can lead to heavy damages of the gearbox. The experimental investigations on a modified FZG back-to-back test rig show a strong effect of operating conditions and grease properties on the lubricant supply: A higher amount of grease in the gearbox and a higher lubricant temperature support circulating, whereas, a higher consistency of the grease supports channeling. Based on the results, a first calculation approach is developed that approximates the lubricant supply of grease lubricated gears for the gear design process.
The Design of Static Test Scheme for Composite Aileron Structure of Large Aircraft
Authors: Zhang Guanbiao , Liu Shuaicai , Zhang Limeng , Zhang Jiying
Published: March 2021

According to the load conditions and structural features of composite aileron structure of large aircraft, the design techniques of full-scale static test scheme of aileron is studied, which can be used to examine the static strength and verify the airworthiness compliance of aileron structure. The overall test scheme design was carried out from the aspects of test load, test support, damage introduction and measurement scheme, and created a set of test design processes that meet the requirements of airworthiness. Loads screening was carried out by using strain coverage principle, the aerodynamic loads were transformed into test load by coordinate transformation. The wing was used as the aileron test support section, and a ground support device can also be designed to carry out aileron bench test. The introduction mode of aileron structure damage was defined, including the type, location and size. A reasonable layout of strain and displacement sensors was given for test measurement. Test results showed that the static test scheme in this paper can be used for the airworthiness compliance verification of static strength of aileron structure.