Search results for: urban density

Authors: Sam Bahreini, Payam Hayati

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Metal-organic coordination [Cu(L)₄(SCN)₂] was synthesized applying ultrasonic irradiation, and its photocatalytic performance for the degradation of Remdesivir (RS) under sunlight irradiation was systematically explored for the first time in this study. The physicochemical properties of the synthesized photocatalyst were investigated using Fourier-transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), powder x-ray diffraction (PXRD), energy-dispersive x-ray (EDX), thermal gravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS) techniques. Systematic examinations were carried out by changing irradiation time, temperature, solution pH value, contact time, RS concentration, and catalyst dosage. The photodegradation kinetic profiles were modeled in pseudo-first order, pseudo-second-order, and intraparticle diffusion models reflected that photodegradation onto [Cu(L)₄(SCN)₂] catalyst follows pseudo-first order kinetic model. The fabricated [Cu(L)₄(SCN)₂] nanostructure bandgap was determined as 2.60 eV utilizing the Kubelka-Munk formula from the diffuse reflectance spectroscopy method. Decreasing chemical oxygen demand (COD) (from 70.5 mgL-1 to 36.4 mgL-1) under optimal conditions well confirmed mineralizing of the RS drug. The values of ΔH° and ΔS° was negative, implying the process of adsorption is spontaneous and more favorable in lower temperatures.

Keywords: Photocatalytic degradation, COVID-19, density functional theory (DFT), molecular electrostatic potential (MEP)

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Authors: Maíra O. Palm, Cintia Marangoni, Ozair Souza, Noeli Sellin

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Wastes from a vegetal extracts industry (cocoa, oak, Guarana and mate) were characterized by particle size, proximate and ultimate analysis, lignocellulosic fractions, high heating value, thermal analysis (Thermogravimetric analysis – TGA, and Differential thermal analysis - DTA) and energy density to evaluate their potential as biomass in the form of briquettes for power generation. All wastes presented adequate particle sizes to briquettes production. The wastes showed high moisture content, requiring previous drying for use as briquettes. Cocoa and oak wastes had the highest volatile matter contents with maximum mass loss at 310 ºC and 450 ºC, respectively. The solvents used in the aroma extraction process influenced in the moisture content of the wastes, which was higher for mate due to water has been used as solvent. All wastes showed an insignificant loss mass after 565 °C, hence resulting in low ash content. High carbon and hydrogen contents and low sulfur and nitrogen contents were observed ensuring a low generation of sulfur and nitrous oxides. Mate and cocoa exhibited the highest carbon and lignin content, and high heating value. The dried wastes had high heating value, from 17.1 MJ/kg to 20.8 MJ/kg. The results indicate the energy potential of wastes for use as fuel in power generation.

Keywords: agro-industrial waste, biomass, briquettes, combustion

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Authors: Amin Jabbari

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The state of the art in major 3D printing technologies, such as powder-based and slurry based, has led researchers to investigate the ability to fabricate bone scaffolds for bone tissue engineering using biomaterials. In addition, 3D printing technology can simulate mechanical and biological surface properties and print with high precision complex internal and external structures that match their functional properties. Polymer matrix composites reinforced with particulate bioceramics, hydrogels reinforced with particulate bioceramics, polymers coated with bioceramics, and non-porous bioceramics are among the materials that can be investigated for bone scaffold printing. Furthermore, it was shown that the introduction of high-density micropores into the sparingly dissolvable CSiMg10 and dissolvable CSiMg4 shell layer inevitably leads to a nearly 30% reduction in compressive strength, but such micropores can easily influence the ion release behavior of the scaffolds. Also, biocompatibility tests such as cytotoxicity, hemocompatibility and genotoxicity were tested on printed parts. The printed part was tested in vitro, and after 24-26 h for cytotoxicity, and 4h for hemocompatibility test, the CSiMg4@CSiMg10-p scaffolds were found to have significantly higher osteogenic capability than the other scaffolds of implantation. Overall, these experimental studies demonstrate that 3D printed, additively-manufactured bioceramic calcium (Ca)-silicate scaffolds with appropriate pore dimensions are promising to guide new bone ingrowth.

Keywords: AM, 3D printed implants, bioceramic, tissue engineering

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Authors: Srijitra Khanpakdee, Teera Butburee, Jung-Ho Yun, Miaoqiang Lyu, Supphasin Thaweesak, Piangjai Peerakiatkhajohn

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The synthesis of titanium dioxide (TiO₂) nanorods (NRs) on fluorine-doped tin oxide (FTO) glass via hydrothermal methods was investigated to determine the optimal reaction time for enhanced photocatalytic and optical performance. Reaction times of 4, 6, and 8 hours were studied. Characterization through SEM, UV-vis, XRD, FTIR, Raman spectroscopy and photoelectrochemical (PEC) techniques revealed significant differences in the properties of the TiO₂ NRs based on the reaction duration. XRD and Raman spectroscopy analysis confirmed the formation of the rutile phase of TiO₂. As photoanodes in PEC cells, TiO₂ NRs synthesized for 4 hours exhibited the best photocatalytic activity, with the highest photocurrent density and superior charge transport properties, attributed to their densely packed vertical structure. Longer reaction times resulted in less optimal morphological and photoelectrochemical characteristics. The bandgap of the TiO₂ NRs remained consistent around 3.06 eV, with only slight variations observed. This study highlights the critical role of reaction time in hydrothermal synthesis, identifying 4 hours as the optimal duration for producing TiO₂ NRs with superior photoelectrochemical performance. These findings provide valuable insights for optimizing TiO₂-based materials for solar energy conversion and renewable energy applications.

Keywords: titanium dioxide, nanorods, hydrothermal, photocatalytic, photoelectrochemical

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Authors: Quan Li, Dongcai Shen, Zhengting Xiao, Xin Liu Mingrui Wu, Licheng Liu, Qin Li, Xianguo Li, Wentai Wang

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Direct electrocatalytic nitrogen oxidation (NOR) provides a promising alternative strategy for synthesizing high-value-added nitric acid from widespread N₂, which overcomes the disadvantages of the Haber-Bosch-Ostwald process. However, the NOR process suffers from the limitation of high N≡N bonding energy (941 kJ mol− ¹), sluggish kinetics, low efficiency and yield. It is a prerequisite to develop more efficient electrocatalysts for NOR. Herein, we synthesized double-shelled CeO₂ hollow spheres (D-CeO₂) and further modified with Ti₃C₂ MXene quantum dots (MQDs) for electrocatalytic N₂ oxidation, which exhibited a NO₃− yield of 71.25 μg h− ¹ mgcat− ¹ and FE of 31.80% at 1.7 V. The unique quantum size effect and abundant edge active sites lead to a more effective capture of nitrogen. Moreover, the double-shelled hollow structure is favorable for N₂ fixation and gathers intermediate products in the interlayer of the core-shell. The in-situ infrared Fourier transform spectroscopy confirmed the formation of *NO and NO₃− species during the NOR reaction, and the kinetics and possible pathways of NOR were calculated by density functional theory (DFT). In addition, a Zn-N₂ reaction device was assembled with D-CeO₂/MQDs as anode and Zn plate as cathode, obtaining an extremely high NO₃− yield of 104.57 μg h− ¹ mgcat− ¹ at 1 mA cm− ².

Keywords: electrocatalytic N₂ oxidation, nitrate production, CeO₂, MXene quantum dots, double-shelled hollow spheres

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Authors: Yun-Pang Flötteröd, Jakob Erdmann

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The human behaviors during evacuations are quite complex. One of the critical behaviors which affect the efficiency of evacuation is route choice. Therefore, the respective simulation modeling work needs to function properly. In this paper, Simulation of Urban Mobility’s (SUMO) current dynamic route modeling during evacuation, i.e. the rerouting functions, is examined with a real case study. The result consistency of the simulation and the reality is checked as well. Four influence factors (1) time to get information, (2) probability to cancel a trip, (3) probability to use navigation equipment, and (4) rerouting and information updating period are considered to analyze possible traffic impacts during the evacuation and to examine the rerouting functions in SUMO. Furthermore, some behavioral characters of the case study are analyzed with use of the corresponding detector data and applied in the simulation. The experiment results show that the dynamic route modeling in SUMO can deal with the proposed scenarios properly. Some issues and function needs related to route choice are discussed and further improvements are suggested.

Keywords: evacuation, microscopic traffic simulation, rerouting, SUMO

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Authors: Ssekamanya, Mastura Badzis, Khamsiah Ismail, Dayang Shuzaidah Bt Abduludin

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With rising incidents of school violence worldwide, educators and researchers are trying to understand and find ways to enhance the safety of children at school. The purpose of this study was to investigate the extent to which the demographic variables of gender, age, length of service, position, academic qualification, and school location predicted teachers’ awareness about school safety practices in Malaysian primary schools. A stratified random sample of 380 teachers was selected in the central Malaysian states of Kuala Lumpur and Selangor. Multiple regression analysis revealed that none of the factors was a good predictor of awareness about school safety training, delivery methods of school safety information, and available school safety programs. Awareness about school safety activities was significantly predicted by school location (whether the school was located in a rural or urban area). While these results may reflect a general lack of awareness about school safety among primary school teachers in the selected locations, a national study needs to be conducted for the whole country.

Keywords: school safety awareness, predictors of school safety, multiple regression analysis, malaysian primary schools

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Authors: Xuran Zhang, Huiru Chen

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In recent years, China has made great efforts to cultivate and develop the housing rental market, especially the rental-type public housing, which has been paid attention to by all sectors of the society. This paper takes Hangzhou rental-type public housing as the research object, and divides it into three development stages according to the different supply modes of rental-type public housing. Through data collection and field research, the paper summarizes the spatial characteristics of rental-type public housing from the five perspectives of spatial planning, spatial layout, spatial integration, spatial organization and spatial configuration. On this basis, the paper proposes the optimization of the spatial layout. The study concludes that the spatial layout of rental-type public housing should be coordinated with the development of urban planning. When planning and constructing, it is necessary to select more mixed construction modes, to be properly centralized, and to improve the surrounding transportation service facilities.  It is hoped that the recommendations in this paper will provide a reference for the further development of rental-type public housing in Hangzhou.

Keywords: Hangzhou, rental-type public housing, spatial distribution, spatial optimization

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Authors: Sky Chou, Joseph C. Chen

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This paper focuses on using six sigma methodologies to reach the desired shrinkage of a manufactured high-density polyurethane (HDPE) part produced by the injection molding machine. It presents a case study where the correct shrinkage is required to reduce or eliminate defects and to improve the process capability index Cp and Cpk for an injection molding process. To improve this process and keep the product within specifications, the six sigma methodology, design, measure, analyze, improve, and control (DMAIC) approach, was implemented in this study. The six sigma approach was paired with the Taguchi methodology to identify the optimized processing parameters that keep the shrinkage rate within the specifications by our customer. An L9 orthogonal array was applied in the Taguchi experimental design, with four controllable factors and one non-controllable/noise factor. The four controllable factors identified consist of the cooling time, melt temperature, holding time, and metering stroke. The noise factor is the difference between material brand 1 and material brand 2. After the confirmation run was completed, measurements verify that the new parameter settings are optimal. With the new settings, the process capability index has improved dramatically. The purpose of this study is to show that the six sigma and Taguchi methodology can be efficiently used to determine important factors that will improve the process capability index of the injection molding process.

Keywords: injection molding, shrinkage, six sigma, Taguchi parameter design

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Authors: Myriam Ben Said, Dhekra Trabelsi, Faouzi Achouri, Marwa Ben Saad, Latifa Bousselmi, Ahmed Ghrabi

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This present study suggests the use of biological and natural bactericide, cheap, safe to handle, natural, environmentally benign agents to enhance the conventional wastewater treatment process. In the same sense, to highlight the enhancement of wastewater photocatalytic treatability, we were used virulent bacteriophage(s) and essential oils (EOs). The pre-phago-treatment of wastewater with lytic phage(s), leads to a decrease in bacterial density and, consequently, limits the establishment of intercellular communication (QS), thus preventing biofilm formation and inhibiting the expression of other virulence factors after photocatalysis. Moreover, to increase the photocatalytic efficiency, we were added to the secondary treated wastewater 1/1000 (w/v) of EO of thyme (T. vulgaris). This EO showed in vitro an anti-biofilm activity through the inhibition of plonctonic cell mobility and their attachment on an inert surface and also the deterioration of the sessile structure. The presence of photoactivatable molecules (photosensitizes) in this type of oil allows the optimization of photocatalytic efficiency without hazards relayed to dyes and chemicals reagent. The use of ‘biological and natural tools’ in combination with usual water treatment process can be considered as a safety procedure to reduce and/or to prevent the recontamination of treated water and also to prevent the re-expression of virulent factors by pathogenic bacteria such as biofilm formation with friendly processes.

Keywords: biofilm, essential oil, optimization, phage, photocatalysis, wastewater

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Authors: Jitendra Aswani

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In the first section of this study, impact of Global Financial Crisis (GFC) on the synchronization of fourteen Asian Stock Markets (ASM’s) of countries like Hong Kong, India, Thailand, Singapore, Taiwan, Pakistan, Bangladesh, South Korea, Malaysia, Indonesia, Japan, China, Philippines and Sri Lanka, has been analysed using the network science and its metrics like degree of node, clustering coefficient and network density. Then in the second section of this study by introducing the US stock market in existing network and developing a Minimum Spanning Tree (MST) spread of crisis from the US stock market to Asian Stock Markets (ASM) has been explained. Data used for this study is adjusted the closing price of these indices from 6th January, 2000 to 15th September, 2013 which further divided into three sub-periods: Pre, during and post-crisis. Using network analysis, it is found that Asian stock markets become more interdependent during the crisis than pre and post crisis, and also Hong Kong, India, South Korea and Japan are systemic important stock markets in the Asian region. Therefore, failure or shock to any of these systemic important stock markets can cause contagion to another stock market of this region. This study is useful for global investors’ in portfolio management especially during the crisis period and also for policy makers in formulating the financial regulation norms by knowing the connections between the stock markets and how the system of these stock markets changes in crisis period and after that.

Keywords: global financial crisis, Asian stock markets, network science, Kruskal algorithm

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Authors: Gehan Aouf, Diala Tabbal, Abd El Rahim Sabsabi, Rashad Aouf

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The aim of this study is to assess the viability of utilizing Municipal Solid Waste Incineration Fly Ash (MSWIFA) with Ordinary Portland cement as soil reinforcement materials for geotechnical engineering applications. A detailed experimental program is carried out, followed by analysis of results. Soil samples were prepared by adding Cement to MSWIFA-soil mix at different percentages. Then, a series of laboratory tests were performed, namely: Sieve analysis, Atterberg limits tests, Unconfined compression test, and Proctor tests. A parametric study is conducted to investigate the effect of adding the cement at different percentages on the unconfined compression strength, maximum dry density, and optimum moisture content of clayey soil-MSWIFA The variation of contents of admixtures were 10%, 20%, and 30% for MSWIFA by dry total weight of soil and 10%, 15%, and 20% for Portland cement by dry total weight of the mix. The test results reveal that adding MSWIFA to the soil up to 20% increased the MDD of the mixture and decreased the OMC, then an opposite trend for results were found when the percentage of MSWIFA exceeds 20%. This is due to the low specific gravity of MSWIFA and to the greater water absorption of MSWIFA. The laboratory tests also indicate that the UCS values were found to be increased for all the mixtures with curing periods of 7, 14, and 28 days. It is also observed that the cement increased the strength of the finished product of the mix of soil and MSWIFA.

Keywords: clayey soil, cement, MSWIFA, unconfined compression strength

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Authors: C. E. Sutton, A. Varvani-Farahani

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Fatigue damage and life prediction of particle metal matrix composites (PMMCs) under uniaxial and multiaxial loading conditions were investigated. Three PMM composite materials of Al6061/Al2O3/20p-T6, Al6061/Al2O3/22p-T6 and Al6061/SiC/17w-T6 tested under tensile, torsion, and combined tension-torsion fatigue cycling were evaluated with various fatigue damage models. The fatigue damage models of Smith-Watson-Topper (S. W. T.), Ellyin, Brown-Miller, Fatemi-Socie, and Varvani were compared for their capability to assess the fatigue damage of materials undergoing various loading conditions. Fatigue life predication results were then evaluated by implementing material-dependent coefficients that factored in the effects of the particle reinforcement in the earlier developed Varvani model. The critical plane-energy approach incorporated the critical plane as the plane of crack initiation and early stage of crack growth. The strain energy density was calculated on the critical plane incorporating stress and strain components acting on the plane. This approach successfully evaluated fatigue damage values versus fatigue lives within a narrower band for both uniaxial and multiaxial loading conditions as compared with other damage approaches studied in this paper.

Keywords: fatigue damage, life prediction, critical plane approach, energy approach, PMM composites

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Authors: M. A. Medeiros, A. A. N. Dantas, F. A. N. França, R. F. Amaral

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There are several alternatives of coastal erosion control with geosynthetics. As an important stage of any Civil Engineering project, literature review is necessary in order to evaluate these alternatives and to guide the decisions. Ponta Negra beachfront has a very intensive urban pressure. In addition, a very short sand area induces high intensity erosion processes. Different attempts of solving the problem were already built. However, erosion issues are still an important concern since these structures collapsed. Geosynthetics present a great potential to be applied in this area. In order to study coastal erosion control alternatives with the use of geosynthetics, this paper presents a literature review about this subject. Several studies were collected in which beach conditions are similar to those found in Ponta Negra beach. It was possible to evaluate the alternatives that might be used in the area. Further studies include the application of such techniques in pilot areas and the evaluation of the erosion process. Finally, the best alternative for futures studies on Ponta Negra beach is geocontainers of geotextiles.

Keywords: geosynthetics, coastal erosion control, alternatives, Ponta Negra beach

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Authors: Athar Hussain Memon

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Objectives: We tried to determine the frequency of raised C-reactive protein (CRP) in patients with type 2 diabetes mellitus. Patients and Methods: This cross-sectional descriptive study of six months study was conducted at Liaquat University Hospital Hyderabad from March 2013 to August 2013. All diabetic patients of ≥35 years age of either gender for >01 year duration visited at OPD were evaluated for C-reactive protein and their glycemic status by hemoglobin A1c. The data was analyzed in SPSS and the frequency and percentage were calculated. Results: During six month study period, total 100 diabetic patients were evaluated for C-reactive protein. The majority of patients were from urban areas 75/100 (75%). The mean ±SD for age of patients with diabetes mellitus was 51.63±7.82. The mean age ±SD of patient with raised CRP was 53±7.21. The mean ±SD for HbA1c in patients with raised CRP is 9.55±1.73. The mean random blood sugar level in patients with raised CRP was 247.42 ± 6.62. The majority of subjects were of 50-69 years of age group with female predominance (p=0.01) while the CRP was raised in 70 (70%) patients in relation to age (p=0.02) and gender (p=0.01), respectively. Both HbA1c and CRP were raised in 64.9% (p=0.04) in patients with type 2 diabetes mellitus. The mean ±SD of CRP was 5.8±1.21 while for male and female individuals with raised CRP was 3.52±1.22 and 5.7±1.63, respectively. Conclusions: The raised CRP was observed in patients with type 2 diabetes mellitus.

Keywords: diabetes mellitus, C-reactive protein, hemoglobin A1c, diabetes and metabolism

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Authors: Abdurraheem A. Yakub

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Housing is one of the needs of mankind and is one of the best indicators of a person’s standard of living. This research was set out to analyze the housing qualities and conditions in Kano. Primary data was collected through both Personal observations where the researcher carried out an inspection of the study area prior to interview/implementation of questionnaires and took into consideration the type of housing units, construction materials and services available as well as the environmental condition of the study area. This was followed by an interview which was done through personal contact with the various people related to the study. In the course of doing that, questions were asked orally and notes were taken to record the responses. Thereafter, the Questionnaire was implemented which was earlier designed to elicit information from households in the study area using well-structured questions related to the type of facilities provided in the housing unit, types of houses and response with regard to quality of their houses and neighborhoods, tenure of house. The research work looked at the prevailing housing qualities and conditions and the state of the existing facilities and amenities within the environment and offered recommendations on policies and measures that could help improve the situation.

Keywords: housing provision, housing quality, housing standard, housing condition, housing affordability and housing facilities

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Authors: Zhao Yang Liu, Jing Tao

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The Asian long-horned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiinae), is a wood-borer and polyphagous xylophages native to Asia and killing healthy trees. As it causes serious danger to trees, the beetle has been paid close attention in the world. However, the genetic markers limited, especially microsatellite. In this study, 24 novel simple sequence repeat (SSR) molecular markers, a powerful tool for genetic diversity studies and linkage map construction, were developed and characterized from whole genome shotgun sequences. We developed SSR loci of 2 to 6 repeated and perfect units including 9895 points, the density of SSRs was found one SSR per 56.57 kb and the abundance of SSR was 0.02/kb, besides 140 types of repeats motifs were found. Half of the 48 pairs SSR primers (containing 4 di-, 7 tri-, 2 tetra- and 11 hexamers SSRs) we selected randomly from 1222 pairs of primers were polymorphism. The number of alleles for these markers in 48 individuals varied from 3 to 21 with an average of 7.71, the number of effective alleles ranged from 1.22 to 9.97 with an average of 3.54. Besides this, the polymorphic information content (PIC) ranged from 0.18 to 0.89 with a mean of 0.65, And Shannon's Information index (I) ranged from 0.46 to 2.62 with an average of 1.44. The results suggest that the method for screening of SSR in the whole genome is feasible and efficient. SSR markers developed in this study can be used for population genetic studies of A. glabripennis. Moreover, they may also be helpful for the development of microsatellites for other Coleoptera.

Keywords: SSR markers, Anoplophora glabripennis, genetic diversity, whole genome

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Authors: Jiashu Shen

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This study aims at exploring the characteristics of sexual knowledge, attitudes, and behaviors of Chinese college students from the 'one-child' families compared with those with siblings. This study utilized the data from the 'National College Student Survey on Sexual and Reproductive Health 2019'. Multiple logistic regression analyses were used to assess the association between the 'only-child' and their sexual knowledge, sexual attitudes, sexual behaviors, and risky sexual behaviors (RSB) stratified by sex and home regions, respectively. Compared with students with siblings, the 'only-child' students scored higher in sex-related knowledge (only-child students: 4.49 ± 2.28, students with siblings: 3.60 ± 2.27). Stronger associations between only-child and more liberal sexual attitudes were found in urban areas, including the approval of premarital sexual intercourse (OR: 1.51, 95% CI: 1.50-1.65) and multiple sexual partners (OR: 1.85, 95% CI: 1.72-1.99). For risky sexual behaviors, being only-child is more likely to use condoms in first sexual intercourse, especially among male students (OR: 0.68, 95% CI: 0.58-0.80). Only-child students are more likely to have more sexual knowledge, more liberal sexual attitude, and less risky sexual behavior. Further health policy and sex education should focus more on students with siblings.

Keywords: attitudes and behaviors, only-child students, sexual knowledge, students with siblings

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Authors: Ajay Sidana, Kulbir Singh Sandhu, Balwinder Singh Sidhu

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Joining of dissimilar non-ferrous alloys like aluminium and magnesium alloys becomes important in various automobile and aerospace applications due to their low density and good corrosion resistance. Friction Stir Welding (FSW), a solid state joining process, successfully welds difficult to weld similar and dissimilar aluminum and magnesium alloys. Two tool rotation speeds were selected by keeping the transverse speed constant to weld similar and dissimilar alloys. Similar(Al to Al) and Dissimilar(Al to Mg) weld joints were obtained by FSW. SEM scans revealed that higher tool rotation fragments the coarse grains of base material into fine grains in the weld zone. Also, there are less welding defects in weld joints obtained with higher tool rotation speed. The material of dissimilar alloys was mixed with each other forming recrystallised new intermetallics. There was decrease in hardness of similar weld joint however there is significant increase in hardness of weld zone in case of dissimilar weld joints due to stirring action of tool and formation of inter metallics. Tensile tests revealed that there was decrease in percentage elongation in both similar and dissimilar weld joints.

Keywords: aluminum alloys, magnesium alloys, friction stir welding, microstructure, mechanical properties

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Authors: Getaneh Berie Tarekegn

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Wireless communication via unmanned aerial vehicles (UAVs) has drawn a great deal of attention due to its flexibility in establishing line-of-sight (LoS) communications. However, in complex urban and dynamic environments, the movement of UAVs can be blocked by trees and high-rise buildings that obstruct directional paths. With reconfigurable intelligent surfaces (RIS), this problem can be effectively addressed. To achieve this goal, accurate channel estimation in RIS-assisted UAV-enabled wireless communications is crucial. This paper proposes an accurate channel estimation model using long short-term memory (LSTM) for a multi-user RIS-assisted UAV-enabled wireless communication system. According to simulation results, LSTM can improve the channel estimation performance of RIS-assisted UAV-enabled wireless communication.

Keywords: channel estimation, reconfigurable intelligent surfaces, long short-term memory, unmanned aerial vehicles

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Authors: Norbert Csizmadia

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The 21st Century's main power centers are the cities. More than 52% of the world’s population lives in cities, in particular in the megacities which have a population over 10 million people and is still growing. According to various research and forecasts, the main economic concentration will be in 40 megacities and global centers. Based on various competitiveness analyzes and indices, global city centers, and city networks are outlined, but if we look at other aspects of urban development like complexity, connectivity, creativity, technological development, viability, green cities, pedestrian and child friendly cities, creative and cultural centers, cultural spaces and knowledge centers, we get a city competitiveness index with quite new complex indicators. The research shows this result. In addition to the megacities and the global centers, with the investigation of functionality, we got 64 so-called ‘fusiononopolis’ (i.e., fusion-polis) which stand for the most decisive economic power centers of the 21st century. In this city competition Asian centers considerably rise, as the world's functional city competitiveness index is being formed.

Keywords: economic geography, human geography, technological development, urbanism

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Authors: Maria Kjellgren, Sara Lilliehorn, Urban Markström

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Critical components that influence the role and performance of school social workers in Swedish elementary schools will be described and analysed, such as formal regulations, professional self-understanding, and the SSWs’ role in the interplay between professional domains involved in elementary school. The data collection was conducted through four semi-structured focus group interviews with a total of 22 SSWs in four different regions in Sweden. The result reveals three main challenges for the School Social Worker (SSW): (1) To navigate in a pedagogic and medical arena within a multidisciplinary team, (2) To manage ambiguity without any formal regulations and unclear settings and leadership and finally, (3) To negotiate tasks at different levels, with a health promotional and preventive focus, where the SSW ends up, mainly in remedial work with individual children. The results also disclosed that SSWs hold a vague professional self-understanding position with a little formal mandate to perform their work.

Keywords: school social worker, multidisciplinary team, counselling, professional self-understanding, formal regulations

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Authors: Caroline Atef Shoukry Tadros

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Massive Urbanization growth threatens the sustainability of cities and the quality of city life. This raised the need for an alternate model of sustainability, so we need to plan the future cities in a smarter way with smarter mobility. Smart Mobility planning applications are solutions that use digital technologies and infrastructure advances to improve the efficiency, sustainability, and inclusiveness of urban transportation systems. They can contribute to meeting the needs of Urbanization growth by addressing the challenges of traffic congestion, pollution, accessibility, and safety in cities. Some example of a Smart Mobility planning application are Mobility-as-a-service: This is a service that integrates different transport modes, such as public transport, shared mobility, and active mobility, into a single platform that allows users to plan, book, and pay for their trips. This can reduce the reliance on private cars, optimize the use of existing infrastructure, and provide more choices and convenience for travelers. MaaS Global is a company that offers mobility-as-a-service solutions in several cities around the world. Traffic flow optimization: This is a solution that uses data analytics, artificial intelligence, and sensors to monitor and manage traffic conditions in real-time. This can reduce congestion, emissions, and travel time, as well as improve road safety and user satisfaction. Waycare is a platform that leverages data from various sources, such as connected vehicles, mobile applications, and road cameras, to provide traffic management agencies with insights and recommendations to optimize traffic flow. Logistics optimization: This is a solution that uses smart algorithms, blockchain, and IoT to improve the efficiency and transparency of the delivery of goods and services in urban areas. This can reduce the costs, emissions, and delays associated with logistics, as well as enhance the customer experience and trust. ShipChain is a blockchain-based platform that connects shippers, carriers, and customers and provides end-to-end visibility and traceability of the shipments. Autonomous vehicles: This is a solution that uses advanced sensors, software, and communication systems to enable vehicles to operate without human intervention. This can improve the safety, accessibility, and productivity of transportation, as well as reduce the need for parking space and infrastructure maintenance. Waymo is a company that develops and operates autonomous vehicles for various purposes, such as ride-hailing, delivery, and trucking. These are some of the ways that Smart Mobility planning applications can contribute to meeting the needs of the Urbanization growth. However, there are also various opportunities and challenges related to the implementation and adoption of these solutions, such as the regulatory, ethical, social, and technical aspects. Therefore, it is important to consider the specific context and needs of each city and its stakeholders when designing and deploying Smart Mobility planning applications.

Keywords: smart mobility planning, smart mobility applications, smart mobility techniques, smart mobility tools, smart transportation, smart cities, urbanization growth, future smart cities, intelligent cities, ICT information and communications technologies, IoT internet of things, sensors, lidar, digital twin, ai artificial intelligence, AR augmented reality, VR virtual reality, robotics, cps cyber physical systems, citizens design science

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Authors: Jangje Park, So Young Kim

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The market demand for audio quality in mobile devices continues to increase, and audible buzz noise generated in time division communication is a chronic problem that goes against the market demand. In the case of time division type communication, the RF Power Amplifier (RF PA) is driven at the audio frequency cycle, and it makes various influences on the audio signal. In this paper, we measured the ground bounce noise generated by the peak current flowing through the ground network in the RF PA with the audio frequency; it was confirmed that the noise is the cause of the audible buzz noise during a call. In addition, a grounding method of the microphone device that can improve the buzzing noise was proposed. Considering that the level of the audio signal generated by the microphone device is -38dBV based on 94dB Sound Pressure Level (SPL), even ground bounce noise of several hundred uV will fall within the range of audible noise if it is induced by the audio amplifier. Through the grounding method of the microphone device proposed in this paper, it was confirmed that the audible buzz noise power density at the RF PA driving frequency was improved by more than 5dB under the conditions of the Printed Circuit Board (PCB) used in the experiment. A fundamental improvement method was presented regarding the buzzing noise during a mobile phone call.

Keywords: audio frequency, buzz noise, ground bounce, microphone grounding

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Authors: Shohreh Azizi, Memory Tekere, Wag Nel

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An evaluation of the characteristics of wastewater generated from small communities was carried out in relation to decentralized approach for domestic sewage treatment plant and design of biological nutrient removal system. The study included the survey of the waste from various individual communities such as a hotel, a residential complex, an office premise, and an educational institute. The results indicate that the concentration of organic pollutant in wastewater from the residential complex is higher than the waste from all the other communities with COD 664 mg/l, BOD 370.2 mg/l and TSS 248.8 mg/l. And the waste water from office premise indicates low organic load with COD428 mg/l, BOD 232mg/l and TSS 157mg/l. The wastewater from residential complex was studied under activated sludge process to evaluate this technology for decentralized wastewater treatment. The Activated sludge process was operated at different 12to 4 hrs hydraulic retention times and the optimum 6 hrs HRT was selected, therefore the average reduction of COD (85.92%) and BOD (91.28 %) was achieved. The issue of sludge recycling, maintenance of biomass concentration and high HRT reactor (10 L) volume are making the system non-practical for smaller communities.

Keywords: wastewater, small communities, activated sludge process, decentralized system

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Authors: Yahia Mosleh

Abstract:

Both Scenedesmus obliquus and Cosmarium leave were subjected to different concentrations (5, 10, 20, 50, and 80 %) of highly polluted water collected from Haddows drainage, which receives high amount of domestic sewage, and also the increasing agriculture run off and industrial effluent, then disbursed it in El-Salam fresh water canal. The water in that canal dramatically used as drinking water alongside using in irrigation. A total of 25 physicochemical parameters were determined within the drainage polluted water and also up-stream of El-Salam fresh water canal's water. The effect of five concentrations of the tested polluted water were determined on growth density, dry algal biomass, net photosynthetic oxygen production, catalase activity and ascorbic acid content on the two algae "Scenedesmus obliquus and Cosmarium leave". The result reveal that, low concentration support the growth and the physiological activities of both algae. However, the situation is different in the case of high concentrations, where it encourage the growth of Scenedesmus obliquus , meanwhile the same concentration were inhibited the growth and physiological activities of Cosmarium leave. Which indicated that, Scenedesmus obliquus tolerated high pollution better than Cosmarium leave. Finally it can be concluded that, different organisms, however, have different sensitivities to the same pollutants and the same organisms may be more or less damaged by different pollutant. Also, the inhibitory and stimulatory effects of different species varied with concentrations.

Keywords: catalase activity, ascorbic acid content, Scenedesmus, Cosmarium, pollution, biomass

Procedia PDF Downloads 293

Authors: David Morton

Abstract:

This work discusses the relationship between the Vitagraph Company of America (VCA) and the neighborhood of Midwood, Brooklyn, where the company’s largest production studio was located. The relationship between VCA and the Borough of Brooklyn was unique from other production companies in that despite the nationwide popularity of Vitagraph’s films, the content of the films produced by Vitagraph were directly influenced by the cinematic preferences of one specific urban center. In contrast to the national aspirations of the leading production companies of the period such as Twentieth Century Fox, Paramount, and Universal, who set out to attract the broadest audience possible, VCA’s films were aimed to appeal to specific a niche group that embodied Brooklyn’s conservative principles. As a result of the VCA’s alliance with theater owners and movie spectators in Brooklyn, the Vitagraph studio in Midwood became one of the Borough’s most recognizable cultural institutions, and through the production of Vitagraph’s quality films Brooklynites had a significant means of sharing their unique cultural identity with the rest of the United States.

Keywords: Vitagraph Company of America, Midwood, Brooklyn, Vitagrapheville, New York Motion Picture History, silent era, J. Stuart Blackton, Albert Smith

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Authors: Minase Yitbarek Mengistu, Abrham Melkamu, Dawit Yisfaw, Bisrat Belihu, Abdulhakim Lalega

Abstract:

This research was aimed at reducing and recycling waste paper and sawdust from our environment, thereby reducing environmental pollution resulting from the management/disposal of these waste materials. In this research, some mechanical properties of composite ceiling board materials made from waste paper, sawdust, and pineapple leaf fibers were investigated to determine their suitability for use in low-cost construction work. The ceiling board was obtained from the waste of paper, sawdust chips, and pineapple leaf fibers by manual mechanical bonding techniques using dissolved polystyrene films as a binding agent. The results obtained showed that the water absorption values of between 6 % and 8.1 %; as well as density values of 500 kg/mm3 and 611.1 kg/mm3.From our result, the better one is a ratio of pineapple leaf fiber 25%, sawdust 40%, binder 25%, and waste paper 10%. The composite ceiling boards were successfully nailed with firm grips. These values obtained were compared with those of the conventional ceiling boards and it was observed that these composite materials can be used for internal low-cost construction work and Insulation (acoustic and thermal) performance. It is highly recommended that small and medium enterprises be encouraged to venture into waste recycling and the production of these composite ceiling materials to create jobs for skilled and unskilled labor that are locally available.

Keywords: composite material, environment, textile, ceiling board

Procedia PDF Downloads 80

Authors: Sven Weidner

Abstract:

In the last two decades, US-American Independent Cinema has been faced with numerous metamorphoses. With regard to style, content, film aesthetics and themes a large array is offered. And as a consequence of the increasing influence of the world wide web and absolutely new ways of production opportunities alter the indie-film scene fundamentally. While in the 90s many independent films were situated in urban spaces -for instance, films of Jim Jarmusch, Abel Ferrara or Quentin Tarantino- there is a tendency from the 2000s years on to go to rural America. Jeff Nichols, Debra Granik or Matthew Porterfield can be named. Suburbia the symbol of the American Dream and in particular of an emerging prosperity after the Second World War is an essential theme with some independent directors; among them indie icons Todd Solondz and Todd Haynes. Based on selected films of both of them the paper explores the formal and aesthetic structures (narrative, drama, montage, lighting, sound, color) of the pictures and how suburbia, its people, and its "perfect" families are shown and unmasked in all facets. Films are: "Happiness" (1998), "Life During Wartime" (2009) and "Far From Heaven" (2002).

Keywords: US-independent cinema, Suburbia, film history, film analysis

Procedia PDF Downloads 273

Authors: O. Afshar

Abstract:

Unlike other renewable energy sources, tidal current energy is an extremely reliable, predictable and continuous energy source as the current pattern and speed can be predicted throughout the year. A key concern associated with tidal turbines is their long-term reliability when operating in the hostile marine environment. Bio-fouling changes the physical shape and roughness of turbine components, hence altering the overall turbine performance. This paper seeks to employ Computational Fluid Dynamics (CFD) method to quantify the effects of this problem based on the obtained flow field information. The simulation is carried out on a NACA 63-618 aerofoil. The Reynolds Averaged Navier-Stokes (RANS) equations with Shear Stress Transport (SST) turbulent model are used to simulate the flow around the model. Different levels of fouling are studied on 2D aerofoil surface with quantified fouling height and density. In terms of lift and drag coefficient results, numerical results show good agreement with the experiment which was carried out in wind tunnel. Numerical results of research indicate that an increase in fouling thickness causes an increase in drag coefficient and a reduction in lift coefficient. Moreover, pressure gradient gradually becomes adverse as height of fouling increases. In addition, result by turbulent kinetic energy contour reveals it increases with fouling height and it extends into wake due to flow separation.

Keywords: tidal energy, lift coefficient, drag coefficient, roughness

Procedia PDF Downloads 387