bluuebunny/crossref_metadata_2025 huggingface dataset:
Lighting Design: Facets of A Single Phenomenon
Authors: Zaeva-Burdonskaya E A , Nazarov Y V
Published: March 2021

Lighting design today is one of the most actively developing types of design project activities. The definition of the profession reflects a wide range of established practice, which implies the presence of various theoretical positions. However, all experts without exception note the multi-level structure of the new profession, its pronounced interdisciplinary nature, which presents an additional burden for the designer. The scope of creative, engineering and social tasks, as well as IT technologies related to lighting design, reflects the nature of a complicated stage in the formation and development of the profession. The purpose of this publication is to acquaint the professional audience with the complex nature of light design, to identify a number of disciplines that make up its basis. This will allow to outline the ways of formation of new kinds and genres of lighting design, to identify its main priorities. The task of the designer is to choose a direction of activity at various levels: functional, applied, or easel direction; adhere to traditional urban light, work in the genre of multimedia light show, author’s light sculpture, etc. The multidisciplinary nature of the profession is united methodically by the scientific platform of creative activity. The design and artistic component becomes a priority in the hierarchy of innovative professional synthesis of that particular direction. Thus, lighting design is included in the sphere of project creativity, including the scientific and technical base of the new profession. The innovative potential of that activity has a significant impact on the process of its development, on the creation of a product and - as a result - on the quality of life of a wide range of consumers. In the work on the material, an analytical method of art history research was chosen. This allowed us to describe the emerging multidisciplinary problems of lighting design in a fairly broad and comprehensive manner and to outline ways to solve its current problems. The vocational education system is called upon to play a special role in this process.
Convergent Classroom: From Nature to Digital to Cognition in Geometry Acquisition
Authors: Tello Alcides Bernardo , Tarazona Cayto Didi Miraval , Tello Elia Bernardo , Mallqui Teófanes Huerta
Published: March 2021

Artificial Intelligence can provide intelligent solutions for the educational system. This article uses an object detection algorithm to explore physical surroundings and extract geometric shapes from two- and three-dimensional objects in real time within or outside a classroom. Having the shapes, the geometry lesson begins. We named it “Convergent Classroom”. We have conducted a post-test only group design in which first-year pupils from secondary school participated in the sessions. Our main results show substantial statistical evidence to support pupils’ higher geometry acquisition engagement using computer vision algorithm, compared to those who did not use it. This nature-to-digital-to-cognition engagement can be further explored by neuroscience measurement to understand what happens in pupils’ brain when they connect geometrical shapes from their surroundings to geometric cognition. Furthermore, these observed significant differences call for teachers to implement the already known algorithms in future classrooms.
Towards Rebuilding the Design Model of Programs by Static Analysis and Abstraction
Authors: Wen Yanjun , Chen Liqian , Wang Ji
Published: March 2021

It is difficult to understand a complex software program if its detailed design is not available. A model-rebuilding approach is presented to recover the design on an abstract level. In this approach, by static analysis of the program, a design is constructed and described in an abstract program which includes all behaviour that is observable at a set of selected program points. The approach provides an effective way for the understanding of complex programs.
A Fuzzy Adaptive PID Control Algorithm with Improved Quantification Factor
Authors: Shi Yile , Qiao Zhiyong , Bai Keqiang , Chen Guo , Liu Zhigui
Published: March 2021

The phase-shifting full bridge digital power supply based on Fuzzy PID control is difficult to realize the full mapping from the fuzzy universe to the actual output domain, resulting in the loss of fuzzy control quantity, resulting in the dynamic performance problems of large amplitude and long time output fluctuation. In this paper, a fuzzy adaptive PID control algorithm with improved quantification factor is proposed. The online adjustment function of quantification factor in fuzzy universe is introduced in the quantification link. The function can adjust the fuzzy quantification factor in real time according to the current sampling error and error change rate of the system. In order to verify the effectiveness of the improved algorithm, the traditional PID control, the traditional fuzzy PID control and the quantification factor improved fuzzy PID control are applied to the phase-shifting full bridge small signal disturbance model respectively. The results show that the fuzzy adaptive PID control algorithm with the quantification factor online adjustment function has higher dynamic performance.
Effects of Nano-WC on Microstructure and Wear Resistance of Laser Cladding Ni-based Coating on 42CrMoA Alloy Steel
Authors: Li Y F , Shi Y , Wu Q T
Published: March 2021

In the paper, Ni45 coating was manufactured by laser cladding on 42CrMoA alloy steel using the 5 kW CO2 laser, four-axis CNC machines and the coaxial powder feeding system. It was investigated that the effects of nano-WC on microstructure and wear resistance of the Ni-based coating. The macromorphology and microstructures were analyzed by SEM, XRD and microhardness tester. The wear tests were conducted on the Friction and Wear tester. The microstructure was first refined and then coarsened as the increase of nano-WC addition. When the nano-WC addition is 3.0 wt.%, the coating showed the finest microstructure. The clad layers including γ-Ni, N3B, M23C6 and WC, W2C. Meanwhlie, the wear rates of coating were gradually decreased.
Optimal Guidance Law for Intercepting the Active Defense Aircraft with Terminal Angle Constraint
Authors: Zhang Hao , Zhang Yiqun , Zhang Pengfei
Published: March 2021

For the scenario where the target can actively defend against the attacking missile, an optimal guidance law for the attacking missile that can simultaneously evade the defending missile and intercept the target is proposed. To increase lethality of the attacking missile, the terminal angle constraint is considered. Assuming that the defending missile and the target is using a known control strategy, the guidance law design problem for the attacking missile is formulated as an optimal control problem with inequality constraint. General solution of the problem is derived for arbitrary order dynamics of the adversaries. Then first-order dynamics of the three players are considered and an analytic solution is presented. Numerical simulations are carried out to demonstrate the high performance of the proposed guidance law.
Research on the Evaluation Index System of Trust, Innovation and M&A Value
Authors: Wang Yan , Zhao Deqiang
Published: March 2021

Due to the particular nature of ownership, the motivations for state-owned enterprises to participate in the mixed ownership M&A include not only the realization of corporate capital appreciation and value creation, but also some strategic factors at the national level, such as concentrating state-owned economic power to promote the development of the industry and maintaining stable social development. Based on the characteristics of the self-development of state-owned enterprises and the maximization of interests, this paper constructs the evaluation system of trust mechanism from five dimensions of shareholders’, creditors’, suppliers’, buyers’ and enterprises’ sincerity; constructs the evaluation system of innovation mechanism from three dimensions of technological innovation ability, market competitiveness and sustainable development ability; and the evaluation system of the mixed ownership M&A value of state-owned enterprises from four dimensions of Tobin’s Q, operating cash flow, return on total assets and corporate governance.
Functional Variants in Human ACE2 Can Decrease its Protein Stability and May Influence the Binding with SARS-CoV-2
Authors: Ge Fang , Muhammad Arif
Published: March 2021

As for the transmission of human to human, the recent pandemic of COVID-19 is now spreading among the population, which has already led to 1.86 million deaths. As recently reported, it is the SARS-CoV-2 that causes COVID-19. Furthermore, human ACE2 is the receptor of the coronavirus. Nowadays, it has been reported that missense variants in ACE2 may affect the coronavirus susceptibility. In this work, we explored the functional impacts of missense variants in human ACE2. Briefly, we initially collected the variant in human ACE2, which have been labeled as important sites of ACE2 or the critical binding sites with the spike protein. Thereafter, applying the technology of protein structure homology modeling, we constructed the molecular spatial structure models of the variants. Next, variants molecular models of ACE2 were superimposed over the wild type of ACE2, to observe the structural changes. As experimental results demonstrated, the overall structures of ACE2 variants are similar. However, several variants (i.e., G173S, V184A, I233F, D355N, R357A, R357S, and G575V) in ACE2 are predicted to decrease the stability of human ACE2 protein and/or to be harmful to human health. Accordingly, the final findings could also provide a functional and structural basis for the potential pathogenicity of ACE2-driven viral infections.
Analysis of Temperature, Stress and Displacement Distribution under Freeze-Thaw Considering the Influence of Initial Boundary and Insulation Layers
Authors: Zhang Xiaomei , Jiang Mingjun , Wang Shijun , Zhang Zhe
Published: March 2021

The freeze-thaw disaster in seasonally frozen soil area are challenging the operation safety of power transmission and transformation projects. The distribution of soil temperature and deformation laying below the foundation is significant to the soil stability in seasonally frozen soil area. The temperature distribution of the foundation is closely related to the external temperature, the thermal field of bottom boundary and the materials of insulation layers. In this paper, the typical tower foundation of 750 kV Gansu Hexi power grid project and the geological conditions of Shulehe area in Gansu Province were selected as the investigation site, and the theoretical analysis and numerical simulation methods are used to analyze the thermal-mechanical coupling considering different boundaries. The deformation, stresses and temperature changes of tower foundation and surrounding soil under different thermal protection structures were discussed. Through comparative analysis, it was found that the optimized structure can effectively improve the soil temperature in extreme environment, avoid frost heave, and meet the design requirements of bearing capacity.
Pollution Characteristics and Ecological Risk Assessment of Heavy Metal in the Coast Sediments along Power Plant-Sanshimu Village of Yangzong Lake, Yunnan Province
Authors: Li Yanli , Fan Fu , Li Jin , Ying Xi
Published: March 2021

To explore the current situation of heavy metal pollution in Yangzong Lake areas, the contents of Cu, Zn, Ni, Cr, Fe, Mn, V, Mo, Co, Sr, Li, Be, Cd, As, Pb, Al, Ba and Ti in 40 coast sediment samples along Power Plant-Sanshimu Village were determined. Single factor pollution index, enrichment coefficient and geoaccumulation index were used to evaluate the heavy metal pollution. The results showed that concentrations of Cu, Cr, Co and Be in all samples exceeded their natural background values. The average concentrations of Co, Cd, Cu, Be, Cr, Mo, V, As, Ni, Li, Zn, Mn, Sr and Fe were higher than their natural background values, while Pb, Al, Ba and Ti were opposite. Co, Cd, and Cu were the highest degree of pollution, followed by Be, Cr, Mo and V. Potential ecological risk index indicated a moderate-strong ecological risk. Cd, Co, As and Cu were the main ecological risk factors in this region.
Response of Grassland Slope Erosion to Vegetation Characteristics
Authors: Wang Dongdong , Yuan Zaijian , Jing Dawei , Zhao Chunyu
Published: March 2021

The grassland erosion research on steep slopes is the basis and difficulty, which was studied by artificial rainfall experiments. Results showed the following: (1) Decreasing the stream power (Rω) is main way to decrease the interrill erosion. (2) The regulation effect of grass on stream power and soil erodibility are mainly achieved by grass cover and root volume, separately. (3) The contribution rates of root volume (RV), and soil bulk density (SD) to RK is 73.61%-97.94, and 0.04%-0.22%.
A New Atmospheric Dataset for GIIRS Sampled from ERA5 Using Shannon Entropy Method
Authors: Zhang Qi , Yu Yi , Zhang Weimin
Published: March 2021

Geostationary Interferometric Infrared Sounder (GIIRS) on board the new Chinese geostationary meteorological satellite Fengyun-4A is aimed to obtain three-dimensional atmospheric information regularly at the regional scale. Since the existing atmospheric datasets are global covered and they are not representative of the GIIRS detection area, a diverse and local representative atmospheric dataset is required for GIIRS in training transmittance parameterization scheme of fast radiative transfer model and retrieving atmospheric profiles. The new atmospheric dataset for GIIRS application in this paper is sampled from the European Centre for Medium-Range Weather Forecasts (ECMWF) fifth-generation reanalysis (ERA5) 2019 dataset using Shannon entropy sampling method. The new dataset demonstrates the feature of uniform distribution within multiple atmospheric variables’ (i.e. atmospheric temperature, specific humidity, 2 meter temperature) variation ranges and GIIRS’s spatial coverage. To address the issue derived from the climate difference and the varied vertical pressure structure of regions with great differences in topographic height, the study area is divided into six categories regarding of topographic height categories where atmospheric dataset are sampled separately. Seasonal variation is also taken into account in the process of sampling. Compared with the initial randomly sampled dataset, the atmospheric and 2 meter temperature in the new dataset demonstrate a higher level of uniformity within their variation ranges. The statistical results indicate that the differences between samples in the new dataset are enlarged, meanwhile, the new dataset well retains the statistical characteristics of the original ERA5 dataset. The new dataset has a potential in the study of the utility of GIIRS data in the numerical weather forecast.
HVAC Measures of “Returning to the South” in Guangzhou
Authors: Nie Xian , Chen Wenjing
Published: March 2021

The phenomenon of “water-exit” often appears on the indoor surface in Guangzhou in spring, which is called “returning to the South” by the local people, which brings about health and safety risks. By analyzing the causes of “returning to the South”, this paper points out that the essence of preventing its harm to indoor environment is how to prevent indoor condensation in a high humidity outdoor environment and a low temperature indoor environment. During the design of operation and maintenance, the relevant measures to reduce the indoor air dew point temperature and improve the indoor surface temperature can be considered to reduce the disaster of returning to the south.
The Evaluation of Ecological Service Value of Liaohe River Estuary Wetland
Authors: Zhang Wanshu , Jiang Wei , Lin Yanyu , Mao Qianyi
Published: March 2021

Taking the wetland of the Liaohe River Estuary as the research object and combined with the emergy theory, aquatic product supply service, plant resource supply service, atmospheric oxygen content regulation service, atmospheric carbon dioxide content regulation service, water regulation service, biological habitat regulation service, scientific research culture service value, leisure and entertainment service value are chosen to evaluate the ecological service value of the Liaohe Estuary wetland in 2019. The results of the study show that the total emergy value of the wetland at the mouth of the Liaohe River is 59.931 billion yuan. Among them, the value of supply services is 2.057 billion yuan. The value of regulation services is 53.508 billion yuan, and the value of cultural services is 4.366 billion yuan. In the entire value of Liaohe estuary wetland, regulation service value>cultural entertainment value>supply service value. Among them, the ecological service value of Liaohe estuary wetland mainly comes from water resource regulation service value and biological habitat regulation service value. Therefore, the ecological service value Research is of great significance to the development and utilization of water resources.
Stability Analysis of Gravity Retaining Walls with Different Wall-back Types under Equal Section Area
Authors: Zhuang Jinliang , Chen Jianxu
Published: March 2021

Gravity retaining wall is divided into three types: vertical, upward inclined and bent inclined. There are few studies on the stability of different wall-back types of retaining walls. There is no clear regulation on the selection of retaining wall's back types, so it is difficult to measure the economy and rationality. Under the condition that the cross-section area is equal and other external conditions are the same, according to the Coulomb’s earth pressure theory, the anti-slip stability coefficient and anti-overlapping force stability coefficient of different back types of retaining walls are calculated respectively. Through analysis and comparison, the stability of vertical retaining wall is better than other types under the same conditions, which can be preferred.
Analysis on Seismic Damage Evolution of Seismic-Damaged CSC Columns with Strengthening
Authors: Peng Sheng , Xiong Zhou , Xu Chengxiang , Han Fei
Published: March 2021

To analysis the earthquake damage evolution law, seven composite steel concrete (CSC) columns were manufactured. The experiment consisted of pre-damage loading, reinforcement with enveloped steel jackets (ESJ)/CFRPs and pseudo-static tests. The results showed that the severely damaged specimens strengthened with CFRPs or ESJ have the ability to resist earthquake again. The experimental results were in good agreement with the analytical results. Based on the modification and extension of Reihorn evaluation criterion, the earthquake damage evaluation criterion of seismic-damaged CSC columns with strengthening was obtained, which describes the specimen from “basically intact” to “complete destroyed”. Then, the seismic damage evolution law of specimen was obtained by quantitative analysis of the test results.
The Progressive Partition Method to Identify Damage of Single-Layer Reticulated Shell
Authors: Fu Xiaomin , Ma Cuijuan , Zhang Huidi , Wang Hangyu , Ju Jinsan
Published: March 2021

For the damage location in the existing damage identification methods, this paper adopts the progressive partition method in view of the modal strain energy to locate and evaluate the bars’ damage degree in the K8 single-layer reticulated shell model. Through the correlation between damage identification index and damage degree, the location and damage degree of damage element can be precisely determined. Meanwhile, this method can effectively improve the anti-noise performance in the damage identification of structural, and determine the key elements for the overall stability of single-layer reticulated shells under specific loads. The research provides a basis for the diagnosis and reinforcement of damaged structure.
Study on Pretreatment of Phosphogypsum and Preparation of Non Burning Building Materials
Authors: Wang Haifeng , You Xiaoyu , Tian Jiayu , Cheng Xiaoliang , Wang Jiawei
Published: March 2021

Phosphogypsum has poor cementitious activity, which hinders its large consumption in the field of building materials. By studying the phase and microstructure of phosphogypsum pretreated by alkali activation, and the compressive strength, and microstructure of the non-sintering building materials prepared with the high content phosphogypsum, the process parameters of preparing high content and high compressive strength non-burning building materials with phosphogypsum were obtained. The result showed that, when 100 g phosphogypsum was added with 200 mL activator, after 24 hours of excitation under room temperature, the main crystalline phase CaSO4·2H2O of phosphogypsum have smaller grains and lower crystallinity. Microstructure analysis showed that the particles of tabular phosphogypsum were powdered, and the original plate-like crystal form became smaller plates. Thus, its gelation activity was improved. When the content of phosphogypsum was 80%, the compressive strength of non-burning building materials after maintenance for 7 days, 28 days and after immersion in water for 24h were 15.13 MPa, 16.4 MPa and 11.8 MPa, respectively. The micro morphology showed that the particle size gradient was appropriate and the density was very high, which was very beneficial to improve the strength of the material.
Power System Transient Current Sensor Based on Magnetoresistance Effect
Authors: Bi Lanxi , Wu Mengke , Xu Linbo , Sun Shihang , Yu Kun , Zeng Xiangjun
Published: March 2021

Aiming at the problem that the mixed use of overhead lines and cables causes serious refraction and attenuation of the traveling wave signal in propagation, which makes the traditional traveling wave sensor unable to adapt to the weak signal identification and recording requirements. A wideband sensor for detecting transient current signal of power system is developed. The detection principle of the anisotropic magnetoresistive sensor is analyzed, and the tiny signal precision differential amplifier circuit is designed. Based on the actual situation of the power system, a corresponding test environment was built to conduct transient current transfer tests. The experimental results show that the sensor has a high linearity in the 0-5MHz bandwidth, and is suitable for the extraction of various transient signals, especially in the power system traveling wave protection has high application value.
Study on the Growth Law of Manganese in Electrolysis Process of MnSO4 Solution Containing Magnesium
Authors: Tian Jiayu , Wang Haifeng , You Xiaoyu , Cheng Xiaoliang , Wang Jiawei
Published: March 2021

At present, there was no good industrial removal method for soluble impurity Mg2+ in electrolytic manganese industrial production, so MgSO4-MnSO4-(NH4)2 SO4 compound salt crystal with minimal solubility was formed by cyclic enrichment in solution. On the one hand, it caused the loss of manganese, ammonium and other main components, on the other hand, a large amount of storage caused environmental pollution. In order to find out the harmful effect of magnesium on the production of manganese in an all-round way, this paper studied the growth and deposition of manganese when the concentration of Mg2+ was 25g/L. The results showed that with the increase of electrolysis time, the grain size increases from 42.11μm for 2h to 185.71 μm for 10h, and the current efficiency gradually decreased from 73.3% for 2h to 67.26% for 10h. After 8 hours of electrolysis, the growth rate of grain size and the decrease rate of current efficiency were improved, and there were a certain relationship between them.
Factors of technological development of the Northern Sea Route
Authors: Guzov Iu , Polyakov N , Titov V , Vashchuk A
Published: March 2021

The article is devoted to the issues of technological development of the Northern sea route (NSR). The purpose of the study is to justify the need to create conditions for the technological development of the shipping line, which is a priority, large-scale and commercial project of Russia that provides economic growth of the Arctic regions and the Russian Federation itself. To make NSR the effective in near future, it is necessary to focus on the development of the Arctic icebreaker fleet, satellite communications, emergency rescue facilities, port fleet and digital technologies. As a result of research authors consider factors of technological development as elements of the driving force of the NSR project and an ecosystem of technological innovations that ensures the constant functioning of the shipping artery. The authors deem the following areas as key factors of the NSR’s technological development:

1. Formation of innovation-territorial clusters of enterprises focused on projects for the development of the Arctic Zone of the Russian Federation (AZRF).

2. Creation of special economic zones (SEZ) of technical and innovative type in the administrative centers of the Arctic regions.

3. Stimulating demand for innovative technologies.

4. Building a system of effective international cooperation.

5. Tax incentives for business in the Russian Arctic.

Main conclusions of the research. Technological innovations’ usage in development of the NSR will speed up the process of creating an effective and reliable engineering infrastructure, ensure the uninterrupted movement of ships, will give a powerful push and an extra boost to the sectors of Russian economy (shipbuilding, radio electronics, new materials, oil and gas equipment, etc.) and, as a result, it will create favorable conditions for public - private investment inflow in these industries and for the economy of Arctic regions.
Prospective principles of catalyst utilization using supercritical fluid media
Authors: Gumerov Farid , Bilalov Timur , Khairutdinov Vener , Zaripov Zufar , Gubaidullina Alfiya , EvgenyBelopukhov  , Terekhova Elena , Belskaya Olga , Chernenko Sergey
Published: March 2021

An overview of prospective principles of catalyst utilization using supercritical fluid media is presented. The processes in which these working media act as solvents and extractants, reagents and reaction media are considered. At the same time, we are talking about both heterogeneous catalysts and catalytic complexes dissolved in the water runoff of industrial enterprises. Using the LD-145 catalyst as an example, we studied the possibility of extending its service life instead of recycling, due to a change in the physical and chemical principles of its regeneration. We are talking about replacing the high-temperature process of vapor-air oxidation of catalyst-deactivating compounds with a supercritical fluid extraction process. At the same time, the extractant used is not widespread carbon dioxide, but propane/butane mixture, the use of which makes the process significantly more efficient. This is because a number of binary systems “deactivating compound – extractant” change the type of phase behavior from V-VI to I-II when changing carbon dioxide to propane/butane mixture. Thus, these systems, for example, involving naphthalene, phenol and some other substances in the supercritical fluid state fall outside the binodal of the binary system into the region of unlimited miscibility of components, which significantly increases the kinetics of the catalyst regeneration.
Liquid-phase systems with specified properties based on water-soluble derivatives of cobalt (II) phthalocyanine
Authors: Kovanova Mariia A. , Botnar Anna A. , Domareva Natalya P. , Futerman Natalya A.
Published: March 2021

In this work a wide range of sulfo derivatives of cobalt phthalocyaninewas used as an example for the creation of liquid-phase systems with specified parameters. The role of the spacer bridge in the peripheral position of the macrocycle on its aggregation and coordination properties is illustrated. It was found that associated forms (H-associates) of sulfonated metal phthalocyanines, in which the ionic peripheral group is removed from the macrocycle by oxynaphthyl-/oxyphenylazo-fragments (CoTSPc2 and CoTSPc3, respectively), have absorption in the region of 620-630 nm, while the Q-band of the monomeric form is located in the region 680-700 nm. It is shown that in the concentration range of 10−5 – 10−4 M the change in the optical density for CoTSPc1 and CoTSPc2is described by a linear law. Based on the position of the absorption maxima of the Q-band, phthalocyanines are in an aggregated form in the form of H-aggregates. The study of the coordination properties of macrocycles was carried out with the addition ofbidentate DABCO molecule. The stability of monoligand complexes with DABCO in aqueous solution changes in the order CoTSPc1 > CoTSPc3 > CoTSPc2.
Modeling information flows of the process of drilling wells and developing hydrocarbon deposits on the shelf
Authors: Sidorov Valery
Published: March 2021

The article discusses the issues of modeling business processes and information flows of the process of drilling wells and developing hydrocarbon deposits on the shelf. It is shown that the IDEF0 notation is the most convenient for describing the tasks of the upper level of control and building a complex information model of the object under study. The resulting models make it possible not only to determine the functional interaction of individual independent technological problems, but also to justify the choice of methods and tools for their solution. This is of particular importance in the system of professional development of specialists. Information systems such as WellView (Peloton Company) or GeoView (TyumenNIIgiprogaz) are considered as examples.
Application of GA-HP model for the optimal design of large sewer networks
Authors: Hassan Waqed H. , Jassem Musa H. , Mohammad Safaa S.
Published: March 2021

This research paper describes the application of a GA-HP model to the design of large gravity sewer networks. The main problem associated with the optimum design of sewer networks is achieving applicable designs that offer the lowest possible construction costs. The GA-HP model is a new technique that combines a Genetic Algorithm (GA) with Heuristic Programming (HP). One of the reasons for adopting this model is that determining the optimal design of sewer networks requires two stages: the GA can be used to obtain the optimal diameter, and then HP can be applied to obtain the optimal slope and other hydraulic characteristics. The GA was run using the tournament selection method with one-point crossover and a population size of 200. To ensure the efficiency of the GA-HP model for the design of large networks, the model was examined in two case studies, these being the medium and large networks located in the holy city of Karbala in Iraq, which contains 90 pipes and 91 manholes, and 354 pipes and 355 manholes, respectively. The cost for the applied manual designs was then compared with that for the designs obtained from this model for these networks, which indicated potential savings of 23.7% and 26.6% for the medium and large networks, respectively.
Using lower and upper baffle arrangements to enhance sedimentation tank performance
Authors: Al-Mafraji E A , Al-Mussawy H A
Published: March 2021

Traditional sedimentation tanks are massive structures that needs require extensive detention times to allow the separation of particles from suspension by gravity. Many researchers have proposed methods of enhancing sedimentation efficiency, including changing the geometry of tanks by installing barriers at the bottom of the basin, in order to reduce demand for chemical processes, which require trained operators to determine the appropriate doses of coagulants. The aim of the current research was make the flow route longer and to distribute suspension over various sedimentation tank compartments in order to increase residence time and thus enhance sedimentation, with effects judges based on calculating the turbidity, density, and viscosity, Froude number (Fr), Reynolds number (Re), settling velocity (vs), detention time (D.T.), height of sludge (hs), and sediment removal. The theoretical aspects were supported by the collection of practical results through laboratory testing that showed that the best Fr, Re, and hs occurred in zone 3, where the opening height of the central baffle created a short-circuit that scoured the deposited particle, while the best turbidity removal occurred with the smallest discharge. The evidence overall suggested that adding both lower and upper baffles improves the performance of sedimentation tanks because this arrangement achieves two essential goals: lengthening the track and damping or calming the flow within the settling zone; however, this only occurs if the vertical upper baffle is situated in a suitable location.
The influence of incorporating recycled brick on concrete properties
Authors: Abbas Zena K , Abbood Ahlam A
Published: March 2021

One of the major problems in modern construction is the accumulation of construction and demolition waste; this study thus examines the consumption of waste brick in concrete based on the use of blended nano brick powder as replacement for cement and as a fine aggregate. Seven concrete mixes were developed according to ACI 211.1 using recycled waste brick. Nano powder brick at 0, 5, and 10% was used as a replacement by cement weight, with other mixes featuring 10, 20, and 30% partial replacement by volume of river sand with brick. The experimental results for replacement of cement with nano brick powder showed an enhancement in mechanical properties (compressive, flexural, and tensile strength) at 7, 28, 90, and 180 days for the 10% replacement level, while the mixes with 20% brick sand replacement also showed an improvement in mechanical properties.
The effect of cyclic loading on the nonlinear response of structural concrete members with arbitrary cross-sectional shapes
Authors: Alkhairo A , Oukaili N , Al-Mahaidi R
Published: March 2021

This paper presents a numerical methodology for analysis of the behaviour of structural concrete sections subjected to cyclic loading. Classical beam theory was utilised to calculate sectional deformations (strain and curvature) under normal force and biaxial moment, while a nonlinear sectional analysis is performed via computer software written in Python by discretising the section of any shape, that is a combination of polygons and circles, into infinitesimal triangles or quadrilaterals. The stress-strain relationship of concrete and steel materials under monotonic loading was also implemented to evaluate the concrete’s secant modulus of elasticity at any strain level. A concrete cyclic model representing stress-strain relationships during unloading is thus proposed in which the secant modulus of elasticity of each mesh element is modified based on the stress level attained at the start of the unloading stage. Cyclic behaviour in tension and compression was investigated, including the transition from compression to tension and vice versa. The cyclic model was then implemented in sectional analysis to allow computation of the behaviour of the section at different loading stages. This study also proposes a new technique to calculate residual deformation during each analysis step and thus to plot the hysteresis behaviour of the section. Software was thus developed to estimate the failure load and produce a biaxial moment-curvature diagram, interaction diagram, and stress-strain diagram across the depth of the section for each load case.
The role of religious monuments in restructuring the movement systems in the Wadi Al-Salam cemetery
Authors: Al-Musawi Mahmood H , Al-Mumar Mohammad H , Nasar Zuhair A
Published: March 2021

The holy city of Najaf is a shrine for Muslims from all over the world due to the presence of the Holy Shrine of Imam Ali Bin Abi Talib, the cousin of the Prophet Mohammed (PBUTh), and the Wadi Al-Salam, the Valley of Peace, cemetery, which includes shrines to many Prophets, righteous people, scholars and righteous martyrs. The Holy Shrine of Imam Ali (PBUH) is the most prominent monument, being the factor around which the urban fabric of the city was formed and established. The form of the cemetery has thus developed with the urban fabric of the city, and it includes many religious monuments that attract thousands of visitors and pilgrims from both within and outside of Iraq. Due to this cumulative growth of the cemetery and the irregularity of its axes of movement, the movement of visitors inside the cemetery has produced several design, planning, and security challenges as it has begun to affect the urban fabric of the city and the cemetery itself. Movement and visual interconnections between vital monuments of the religious figures have thus been restricted by the fabric of the Wadi al-Salam Cemetery at both micro and macro levels, generating the current research problem. Accordingly, this research aims to set to explore the possibility of restructuring the movement system of the Wadi Al-Salam Cemetery based on its monuments. The research assumes that the texture of the cemetery can resemble the fabric of the city in terms of adopting the presence of religious monuments to structure spaces. Consequently, the importance of monuments in terms of defining systems of pedestrian and vehicle movement within the fabric of the city was studied to determine the list of indicators classifying the possibilities provided by such monuments according to their historical and religious significance. With regard of the cemetery, several monuments of historical, religious, and contextual significance were then chosen as key points in the restructuring of the local movement systems. The overall research conclusion is that it is important to reconnect these monuments by developing an organic network of movement in order to preserve the graveyards and the historical fabric of the cemetery.
Sustainable textile architecture: history and prospects
Authors: Shareef R A , Al-Alwan H A S
Published: March 2021

Textiles are now used in various applications in different fields, including the building industry. “Textile Architecture” and “Fabric Structures” are gaining new prominence in the construction world because of their multiple unique characteristics, such as being lightweight, low cost, and durable, as well as offering low energy consumption, flexibility, and resilience. In particular, they are respected for their capability of enclosing large spans with minimal material use and construction time. These characteristics appear to offer the potential to develop a unique textile architecture that can also guarantee environmental sustainability.

Fabric structures have been used throughout history, beginning with the early tents built by humans to provide shelters against harsh weather conditions, where no natural shelters were available, and stretching to the the present time, with structures that have been elaborated to meet the needs of more complex applications in different forms, shapes and sizes.

The further development of high-quality materials has triggered a renaissance in textile architecture, yet the current lack of knowledge and limited research on the development of textile architecture and the potentials of such unique structures and techniques in terms of developing sustainable urban contexts, is an ongoing issue. Accordingly, the present paper aims to explore the historical development of textile architecture, and to shed light on the vast range of contemporary modern uses, and architectural applications, as well as discussing the future prospects of this unique sustainable architecture, which may influence the development of new ideas to create aesthetic and cultural contexts within the urban environment. The paper utilises a descriptive research methodology, by tracing the development of such structures to to clarify the recent worldwide progress in the field of architecture in terms of producing outstanding sustainable designs and technical solutions utilising textiles.
The repair of recycled crushed brick aggregate RC beams with shear deficiencies with CFRP
Authors: Hassan Shireen Hamed , Rasheed Laith Sh. , Salih Shakir Ahmed
Published: March 2021

Repairing reinforced concrete (RC) beams using externally bonded carbon fibre reinforced polymer (CFRP) laminate has become one of the main rehabilitation techniques utilised to promote sustainability in construction. The aim of this study was thus to investigate the repair of rectangular simply supported reinforced crushed brick aggregate concrete beams with shear deficiencies in their design. The experimental work consisted of testing twelve full-scale beams (1400 x 200 x 150 mm) under two points load. The specimens were made of normal, and lightweight course aggregate concrete, four beam specimens were used as references, being tested until failure in shear to obtain the ultimate load carrying capacity, while the other specimens were loaded up to 60%-89.4% of the total load at failure, then repaired by wrapping in a layer of CFRP strips in two orientations (90°) and (45°). The variables investigated in this study were therefore the concrete type (normal and lightweight), shear span-to-effective depth ratio (a/d) with two variables (a/d=2.5) and (a/d=3), and the orientation of the CFRP. The results showed that a significant contribution was made by externally bonded CFRP in terms of repairing the beams, which not only refreshes initial shear capacity but also increases the ultimate capacity. The beams showed maximum reliability when the CFRP was oriented at 90° at a ratio of 72%.
Flexural behavior of self-compacting damaged reinforced concrete box beams strengthening with CFRP
Authors: Younis Ahmed A. , Harba Ibrahim S.I. , Abdulridha Abdulkhalik J.
Published: March 2021

Fibre Reinforced Polymer (FRP) materials appear to offer an acceptable solution for the upgrading and repair of concrete structures based on the advantages associated with these compounds. This paper presents an experimental analysis of strengthening in damaged R.C. box beams based on gluing CFRP sheets to the members. The main objective was to study the flexural behaviours of damaged R.C. box beams strengthened with CFRP sheets, and ten simply supported box beam specimens were thus tested under a monotonic two-line load. Variables investigated included the configuration of CFRP sheets used and the damage ratios (45%, 60%, and 75%). The tested box beams were designed according to ACI 318M-14 to ensure flexural failure. The study showed that adding composite fibre sheets used as External Bonding (EB) technology can offer a convenient and effective strengthening method for damaged concrete structures. The results further showed that side strengthening (extending the sheet under the beam with both sides facing each other) provided an effective tool for increasing the ultimate load capacity by over 28% on average as compared to other methods, while increasing the deflection ratio by over 40%. The behaviour of each box beam was examined with respect to the first crack load, ultimate load, crack pattern, and load-deflection, and carbon fabrics were shown play a major role in the repair of box beams.
Performance of Semi-Rigid Steel Connections under Monotonic and Cyclic Loadings: A Review
Authors: Al-Fisalawi Rasha K. , Laith Khalid AL-Hadithy , Al-Kamal Mustafa Kamal
Published: March 2021

Since the turn of the century, numerous articles have been published with analysis of semi-rigid connections in steel structures. This paper offers a comprehensive survey of major recently published research work dealing with the behaviour of semi-rigid beam-column connections under various configurations of fasteners and welding lines under both monotonic and cyclic loads. The review has two main respects: the first is the moment versus curvature behaviours of semi-rigid steel connections, while the second involves finite element analysis of such connections under monotonic and cyclic loads. The main conclusions concerning the dynamic behaviours of semi-rigid steel connections emerge with regard to the vital influence of beam-column connections on the global seismic performance of steel frame structures. Developing semi-rigidity should thus be considered an effective way to achieve the required performance.
Transmission of Stresses in Pavement Layers Subjected to Earthquake Excitation
Authors: Hussein M M , Fattah M Y , Hilal M M
Published: March 2021

A reinforcement interlayer retards the development of cracks in the asphalt overlay by absorbing the stresses induced by both heavy traffic and underlying cracking in the old pavement. The experimental work in this study used laboratory model tests to developed an understanding of the behaviours of sand used as a subgrade under earthquake condition and the its effects of this on flexible pavement and base course layer. The sand subgrade layer has a thickness of 600 mm and the base course was set to 200 mm; the asphalt layer was prepared as a panel with dimensions of 300 x 300 x 50 mm, representing the surface layer. These layers were then tested under the influence of earthquake loading with different frequencies 0.5, 1 and 1.5 Hz. The tests were performed in two parts without adding a geogrid, and with geogrids in the centre of the base layer and between the base and sand layer. Stresses in all three layers are measured using stress sensors, and the displacements of the asphalt layer were measured using two laser displacement sensors. The results for the tests on pavement layers showed that, the stress recorded in models reinforced with geogrids was higher than that seen in unreinforced models, while the displacement was decreased by adding the geogrid in the layers at all three frequencies. When the geogrid is laid between the base and sand layer, the stress in the subgrade layer also lower than that in the base and asphalt layers.
Evaluating noise and pollution indices for the Al-Kufa road network
Authors: Al-Duhaidahawi Zainab S , Almuhanna Raid R A , Al-Jameel Hamid A , Al-Jumaili Mohammed A
Published: March 2021

Determining effective countermeasures and solutions to environmental problems caused by traffic congestion, is a vital task especially in urban areas. This study’s primary purpose was thus to evaluate the road network in Al-Kufa city using several indices, such as noise and pollution. Limited previous studies have discussed the assessment of Al-Kufa road network, creating a need to determine the best means of evaluating noise and pollution levels among the standard options. Noise and pollution were thus investigated for different roads in the city based on field data at peak periods of traffic flow. The results were used to assess the levels of noise and pollution on the tested roads in the network, with the analysis indicating that both noise and pollution levels are generally higher than standard values. Some short- and long-term suggestions to develop more suitable sustainable operational characteristics were thus offered.