Search results for: free space optics

Authors: Harsha B. R., K. S. Anil Kumar

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Land characterization, classification, and soil suitability evaluation of grapes-growing pedons were assessed at fifteen taluks covering four agro climatic zones of Karnataka. Study on problems and potentials of grapes cultivation in selected agro-climatic zones was carried out along with the plant sample analysis. Twenty soil profiles were excavated as study site based on the dominance of area falling under grapes production and existing spatial variability of soils. The detailed information of profiles and horizon wise soil samples were collected to study the morphological, physical, chemical, and fertility characteristics. Climatic analysis and water retention characteristics of soils of major grapes-growing areas were also done. Based on the characterisation and classification study, it was revealed that soils of Doddaballapur (Bangalore Blue and Wine grapes), Bangalore North (GKVK Farm, Rajankunte, and IIHR Farm), Devanahalli, Magadi, Hoskote, Chikkaballapur (Dilkush and Red globe), Yelaburga, Hagari Bommanahalli, Bagalkot (UHS farm) and Indi fall under the soil order Alfisol. Vijaypur pedon of northern dry zone was keyed out as Vertisols whereas, Jamkhandi and Athani as Inceptisols. Properties of Aridisols were observed in B. Bagewadi (Manikchaman and Thompson Seedless) and Afzalpur. Soil fertility status and its mapping using GIS technique revealed that all the nutrients were found to be in adequate range except nitrogen, potassium, zinc, iron, and boron, which indicated the need for application along with organic matter to improve the SOC status. Varieties differed among themselves in yield and plant nutrient composition depending on their age, climatic, soil, and management requirements. Bangalore North (GKVK farm) and Jamkhandi are having medium soil organic carbon stocks of 6.21 and 6.55 kg m⁻³, respectively. Soils of Bangalore North (Rajankunte) were highly suitable (S1) for grapes cultivation. Under northern Karnataka, Vijayapura, B. Bagewadi, Indi, and Afzalpur vineyards were good performers despite the limitations of fertility and free lime content.

Keywords: land characterization, suitability, soil orders, soil organic carbon stock

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Authors: Hacer Erdöl, Merve Aydın, Hacer Kobya Bulut, Kıymet Yeşilçiçek Çalık

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Like all occupations, nursing is significantly influenced by the society which it serves and it also affects it. Social structure affects attitudes of nurses, nursing practice, society's attitudes towards nursing and those who have chosen nursing as a profession. People who choose nursing schools take the views of the society’s they live in on nursing to nursing school. Until the 1960s, many nursing schools had not accepted men as students and women had received nursing education and profession had been carried out by women. In our country, in 2007 an amendment to article eight of Nursing Law was passed and with these changes men also began to be able to choose the nursing as a profession. In Turkish, nurse means 'sister'. Hence, in this study to determine the problems that male nursing students likely encounter at the clinic, non-clinical environment and in their private life regarding the title of nurse, among qualitative research methods phenomenological research design was used. Using purpose sampling method, a total of 18 voluntary male students-13 in third grade and 5 in fourth grade at nursing school- were taken to the study. Data were collected through interviews and by the ethical principles much attention was paid to ensure the confidentiality and to protect participants’ identity. During the interviews lasting 30-40 minutes on average, nine pre-configured standard questions were asked and when necessary free questions were also used in order to ensure the clarity of the responses. With pre- configured standard questions, the reasons why students chose the profession, the problems they had in clinical and non-clinical environment and the potential problems they might encounter in their private lives regarding the title of nurse were questioned. Content analysis was performed on data collected and three main themes were obtained. According to the findings of the evaluation of data, it was found that almost all the students preferred the profession due to possible work opportunities, there were students who did not bother nurse title as well as the ones who did bother and as the most important problem they might encounter in their private lives was to feel worried if their kids had to answer "What does your father" question as "my dad is a nurse" and being ridiculed afterwards. The results of this study show that studies should be done to change the social judgment stemmed from the recognition of nursing as a female profession and take advantage of media through creating public spotlight to accomplish this.

Keywords: choice of profession, the title of the profession, title problems, nursing

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Authors: Marco Soto-Arriaza, Eduardo Cena-Ahumada, Jaime Melendez-Rojel

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Background: Liposomes have been widely used as a model of lipid bilayer to study the physicochemical properties of biological membrane, encapsulation, transport and release of different molecules. Furthermore, extensive research has focused on improving the efficiency in the transport of drugs, developing tools that improve the release of the encapsulated drug from liposomes. In this context, the enzymatic activity of PLA₂, despite having been shown to be an effective tool to promote the release of drugs from liposomes, is still an open field of research. Aim: The aim of the present study is to explore the effect of cholesterol (Cho) and amphipathic di- and tri-block copolymers, on calcein release mediated by enzymatic activity of PLA2 in Dipalmitoylphosphatidylcholine (DPPC) liposomes under physiological conditions. Methods: Different dispersions of DPPC, cholesterol, di-block POE₄₅-PCL₅₂ or tri-block PCL₁₂-POE₄₅-PCL₁₂ were prepared by the extrusion method after five freezing/thawing cycles; in Phosphate buffer 10mM pH 7.4 in presence of calcein. DPPC liposomes/Calcein were centrifuged at 15000rpm 10 min to separate free calcein. Enzymatic activity assays of PLA₂ were performed at 37°C using the TBS buffer pH 7.4. The size distribution, polydispersity, Z-potential and Calcein encapsulation of DPPC liposomes was monitored. Results: PLA₂ activity showed a slower kinetic of calcein release up to 20 mol% of cholesterol, evidencing a minimum at 10 mol% and then a maximum at 18 mol%. Regardless of the percentage of cholesterol, up to 18 mol% a one-hundred percentage release of calcein was observed. At higher cholesterol concentrations, PLA₂ showed to be inefficient or not to be involved in calcein release. In assays where copolymers were added in a concentration lower than their cmc, a similar behavior to those showed in the presence of Cho was observed, that is a slower kinetic in calcein release. In both experimental approaches, a one-hundred percentage of calcein release was observed. PLA₂ was shown to be sensitive to the 4-(4-Octadecylphenyl)-4-oxobutenoic acid inhibitor and calcium, reducing the release of calcein to 0%. Cell viability of HeLa cells decreased 7% in the presence of DPPC liposomes after 3 hours of incubation and 17% and 23% at 5 and 15 hours, respectively. Conclusion: Calcein release from DPPC liposomes, mediated by PLA₂ activity, depends on the percentage of cholesterol and the presence of copolymers. Both, cholesterol up to 20 mol% and copolymers below it cmc could be applied to the regulation of the kinetics of antitumoral drugs release without inducing cell toxicity per se.

Keywords: amphipathic copolymers, calcein release, cholesterol, DPPC liposome, phospholipase A₂

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Authors: David Lynch Steinicke, Citlali Aguilera Lira, Andrea León García

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The proposal posed in this work comes from a researching-action approach. In Mexico, a dialogue of knowledge may function as a link between traditional, local, pragmatic knowledge, and technological, scientific knowledge. The advantage of generating this nexus lies on the positive impact in the environment, in society and economy. This work attempts to combine, on the one hand the traditional Mexican knowledge such as the usage of medicinal herb and the agroecosystem milpa; and on the other hand make use of a newly created agricultural ecotechnology which main function is to take advantage of the urban space and to save water. This ecotechnology is the wicking bed. In a globalized world, is relevant to have a proposal where the most important aspect is to revalorize the culture through the acquisition of traditional knowledge but at the same time adapting them to the new social and urbanized structures without threatening the environment. The methodology used in this work comes from a researching-action approach combined with a practical dimension where an experimental model made of three wickingbeds was implemented. In this model, there were cultivated medicinal herb and milpa components. The water efficiency and the social acceptance were compared with a traditional ground crop, all this practice was made in an urban social context. The implementation of agricultural ecotechnology has had great social acceptance as its irrigation involves minimal effort and it is economically feasible for low-income people. The wicking bed system raised in this project is attainable to be implemented in schools, urban and peri-urban environments, homemade gardens and public areas. The proposal managed to carry out an innovative and sustainable knowledge-based traditional Mexican agricultural technology, allowing regain Milpa agroecosystem in urban environments to strengthen food security in favour of nutritional and protein benefits for the Mexican fare.

Keywords: milpa, traditional medicine, urban agriculture, wicking bed

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Authors: Norhan Anwar Elshikh

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The study aimed to identify the extent of rural women’s awareness of gender issues and discrimination against women. The study also investigated the relationship between the extent of that awareness and the social and economic characteristics of the surveyed women. The study aimed to find both the related factors and the affecting factors of the surveyed women's awareness of gender issues and the discrimination against them. The study then proposed some recommendations that can raise rural women's ability to understand gender issues and discrimination against women. To achieve the study goals, a field study was conducted in the Al-Buhaira governorate. Abu Homs township was chosen as one of the traditional rural areas closest in its characteristics to most rural areas in Egypt, and the Abu Homs township consists of one town and seven rural local units. The local unit of Baraka Ghattas was chosen, as it is considered on average level in human development. Baraka Ghattas local unit includes five villages. Alherfah village and Barakat Ghatas village were chosen to conduct the study as they represent the high and the low levels of human development, respectively. The study included households of women who were in their fertile period in the sample’s villages. The volume of the sample was divided among the two villages according to the number of families in each village, so that each village is represented in the sample space by the same percentage of its presence in the original community. The size of the sample was determined, which is 385 women, According to the Crijsey and Morgen equation. To execute the study, a questionnaire was designed and collected through personal interviews. The results showed that the independent variables most influencing the dependent variable are, from high to low, the economic level of the respondent's family, the number of children of the respondent, the level of formal education of the husband, then leadership ability and the level of ambition, respectively. These variables are responsible for explaining 52% of the change in the extent of rural women's awareness of gender issues and discrimination against women. The study was concluded by providing suggestions and recommendations to improve rural women's awareness of gender issues and discrimination against women.

Keywords: gender, rural women, discrimination, discrimination against women

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Authors: Margherita Cardellini

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To our knowledge, dark skinned children are often victims of discrimination from adults and society, but few studies specifically focus on skin color discrimination on children coming from the same children. Even today, the 'color blind children' ideology is widespread among adults, teachers, and educators and maybe also among scholars, which seem really careful about study expressions of racism in childhood. This social and cultural belief let people think that all the children, because of their age and their brief experience in the world, are disinterested in skin color. Sometimes adults think that children are even incapable of perceiving skin colors and that it could be dangerous to talk about melaninic differences with them because they finally could notice this difference, producing prejudices and racism. Psychology and neurology research projects are showing for many years that even the newborns are already capable of perceiving skin color and ethnic differences by the age of 3 months. Starting from this theoretical framework we conducted a research project to understand if and how primary school children talk about skin colors, picking up any stereotypes or prejudices. Choosing to use the focus group as a methodology to stimulate the group dimension and interaction, several stories about skin color discrimination's episodes within their classroom or school have emerged. Using the photo elicitation technique we chose to stimulate talk about the research object, which is the skin color, asking the children what was ‘the first two things that come into your mind’ when they look the photographs presented during the focus group, which represented dark and light skinned women and men. So, this paper will present some of these stories about episodes of discrimination with an escalation grade of proximity related to the discriminatory act. It will be presented a story of discrimination happened within the school, in an after-school daycare, in the classroom and even episode of discrimination that children tell during the focus groups in the presence of the discriminated child. If it is true that the Declaration of the Right of the Child state that every child should be discrimination free, it’s also true that every adult should protect children from every form of discrimination. How, as adults, can we defend children against discrimination if we cannot admit that even children are potential discrimination’s actors? Without awareness, we risk to devalue these episodes, implicitly confident that the only way to fight against discrimination is to keep her quiet. The right not to be discriminated goes through the right to talk about its own experiences of discrimination and the right to perceive the unfairness of the constant depreciation about skin color or any element of physical diversity. Intercultural education could act as spokesperson for this mission in the belief that difference and plurality could really become elements of potential enrichment for humanity, starting from children.

Keywords: colorism, experiences of discrimination, primary school children, skin color discrimination

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Authors: Tiago Sigal Linhares, Ana Amélia Nascimento da Silva Bones, Juliana Miola, McArthur Alexander Barrow, Airton Tetelbom Stein

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Introduction: As a result of increased globalization and changing migration trends, it is expected that a significant portion of People Living with HIV/AIDS (PLWHA) will change their place of residence over time. In order to provide better health care, monitor the HIV epidemic and plan urban public health care and policies, there is a growing need to formulate a strategy for monitoring PLWHA care, location and migration patterns. The Porto Alegre District is characterized by a high prevalence of PLWHA and is considered one of the epicenters of HIV epidemic in Latin America. Objectives: The aim of this study is to create a digital and easily editable map in order to create a visual representation of the location of PLWHA and to monitor their migration within the city and the country in an effort to promote longitudinal care. Methods: This Experience Report used Google Maps Map Creator to generate an active digital map showing the location and changes in residence of 165 PLWHA who received care at two Primary Health Care (PHC) clinics, which attended an estimated population of five thousand patients, in downtown Porto Alegre over the last four years. Their current addresses were discovered in the unified Brazilian health care system digital records (e-SUS) and updated on the map. Results: A digital map with PLWHA current residence location was created. It was possible to demonstrate visually areas with a large concentration of PLWHA and the migration of the population within the city as wells as other cities, regions and states. Conclusions: An easily reproducible and free map could aid in PLWHA monitoring, urban public health planning, target interventions and situational diagnosis. Moreover, a visual representation of PLWHA location and migration could help bring more attention and investments to areas with geographic inequities or higher prevalence of PLWHA. It also enables notification of local PHC units of monitored patients inside their area, which are in clinical risk or with treatment abandonment through active case findings, improving the care of PLWHA.

Keywords: health care, medical public health, theoretical and conceptual innovations, urban public health

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Authors: Marilou P. Angeles

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Seniors are a growing number of population all over the world, and they are getting sick with illnesses like diabetes, high blood, and high cholesterol. It is necessary to see the relationship of their physical illness and its effect on their quality of life. Having chronic illnesses also can affect the mood of the elderly; becoming cranky, lonely, not eating, etc. Therefore, there is a need to study the relationship of the quality of life of the elderly and the level of depression. Depression for elderly is known as late onset depression or vascular depression since it is tied to the vascular illnesses they are experiencing, although this is not homogeneous. There is heterogeneity in seniors. The purpose of the study is to determine how keep the satisfaction in life i.e., quality of life of seniors, as long as possible. This study was made in 4 barangays in Longos, Potrero, Tonsuya and Catmon, in Malabon, Metro Manila, Philippines. These Filipino seniors are availing of free medicines for their diabetes, high blood, and high cholesterol ailments in the barangay health centers, given freely by the Department of Health. Two instruments were used; quality of life (CASP-19) and patient health questionnaire(PHQ-19). The quality of life questionnaire was based on the theory of Abraham Maslow, human: beings are motivated to action by needs, starting from the lowest, physiological to the highest self-transcendence. Severity of depression is determined by PHQ-9, and according to the unified model of depression by Aaron Beck and Kurt B. Bredemeier, depression happens when a person cannot cope with life has not able to satisfy his needs as a person. The Pearson R correlation was used to determine the significance of the relationship between quality of life and depression. Finding is there is negative relationship between quality of life and depression. It means that a high value of quality of life lowers or minimizes depression. CASP-19 found that the Filipino elderly were in control, independent, enjoying their lives even if they are poor, and this is shown by the significant results. Self-transcendence, a need to give back to others, is important for Filipino elderly. Although the seniors have difficulty with money and they were affected by their illnesses, they are full of optimism, they are ignoring their physical pain because they are focusing on helping their loved ones (i.e., self-transcendence), their children and grandchildrenothers, and if problems come, they are resilient accepting of the challenges, because they have strong faith in God. They are also having pleasures interacting with their friends and neighbors who, like them, have the same health problems. And these two coping strategies for the elderlies allow them to live a meaningful life, a life high in quality. Thus, where there is high quality of life, there is none or minimal depression. Recommendation for future study is finding the relationship of spirituality to quality of life of seniors.

Keywords: CASP-19, depression, quality of life, PHQ-9, senior citizen

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Authors: Akbar Nawaz Khan, Abdul Ghaffar, Muhammad Naeem Riaz

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The study was conducted to investigate the phenotypic features, morphometry and production potentialities of indigenous naked neck chicken (NN) of Pakistan under intensive management condition. A total of 35 NN chicks were randomly selected, and the experiment was performed at Poultry and wildlife research section NARC Islamabad for a period of 22 weeks. The predominant plumage color was black and golden while skin color was observed white. The average shank length, leg length, thigh length, keel length, chest breadth, head width, wing space, wing length, body length, body girth, body height and pubic bone width in adult males and females were 69.19 ± 3.34mm, 117.93 ± 4.42mm, 117.93 ± 4.42mm, 90.87 ± 6.53mm, 95.03 ± 4.56mm, 49.77 ± 2.53mm, 30.63 ± 1.50cm, 27.24 ± 2.71cm, 18.88 ± 0.65cm, 17.77 ± 1.01cm, 25.96 ± 0.56cm, 47.81 ± 1.41cm and 35.69 ± 4.09mm respectively. The average age and live body weight of NN chicken at sexual maturity were recorded as 165.85 days and 1269.38 g. While hen-day egg production of NN was recorded as 45%. The present study was aimed to investigate the existence of polymorphism at IGF-I gene in indigenous naked neck chicken through PCR based Restriction Fragment Length Polymorphism. Based on restriction analysis using Hinf I restriction enzyme, three genotypes were detected designated as AA, AC, and CC. Restriction analysis of PCR amplified product showed the presence of DNA fragments of 622, 378, 244 and 191, (genotypes). The PCR-RFLP analysis is easy, cost effective method which permits the easy characterization of IGF-I gene. This showed the investigated IGF-I genes can serve as good molecular markers for marker assisted selection (MAS) concerning growth related traits in chicken.

Keywords: Desi chicken, naked neck, morphology, morphometry, production potential, egg traits, egg geometry, IGF-I, growth, PCR- RFLP, chicken

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Authors: Gayathri Devi V, Aravamudan Kannan, Amit Sircar

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In the inner fuel cycle system of a nuclear fusion reactor, the Hydrogen Isotopes Removal System (HIRS) plays a pivoted role. It enables the effective extraction of the hydrogen isotopes from the breeder purge gas which helps to maintain the tritium breeding ratio and sustain the fusion reaction. One of the components of HIRS, Cryogenic Molecular Sieve Bed (CMSB) columns with zeolites adsorbents are considered for the physisorption of hydrogen isotopes at 1 bar and 77 K. Even though zeolites have good thermal stability and reduced activation properties making them ideal for use in nuclear reactor applications, their modest capacity for hydrogen isotopes adsorption is a cause of concern. In order to enhance the adsorbent capacity in an informed manner, it is helpful to understand the adsorption phenomena at the quantum electronic structure level. Physicochemical modifications of the adsorbent material enhances the adsorption capacity through the incorporation of active sites. This may be accomplished through the incorporation of suitable metal ions in the zeolite framework. In this work, molecular hydrogen isotopes adsorption on the active sites of functionalized zeolites are investigated in detail using Density Functional Theory (DFT) study. This involves the utilization of hybrid Generalized Gradient Approximation (GGA) with dispersion correction to account for the exchange and correlation functional of DFT. The electronic energies, adsorption enthalpy, adsorption free energy, Highest Occupied Molecular Orbital (HOMO), Lowest Unoccupied Molecular Orbital (LUMO) energies are computed on the stable 8T zeolite clusters as well as the periodic structure functionalized with different active sites. The characteristics of the dihydrogen bond with the active metal sites and the isotopic effects are also studied in detail. Validation studies with DFT will also be presented for adsorption of hydrogen on metal ion functionalized zeolites. The ab-inito screening analysis gave insights regarding the mechanism of hydrogen interaction with the zeolites under study and also the effect of the metal ion on adsorption. This detailed study provides guidelines for selection of the appropriate metal ions that may be incorporated in the zeolites framework for effective adsorption of hydrogen isotopes in the HIRS.

Keywords: adsorption enthalpy, functionalized zeolites, hydrogen isotopes, nuclear fusion, physisorption

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Authors: F. Sahnoune, M. Belhamel, M. Zelmat

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Solar thermal systems available today provide reliability, efficiency and significant environmental benefits. In housing, they can satisfy the hot water demand and reduce energy bills by 60 % or more. Additionally, collective systems or large scale solar thermal systems are increasingly used in different conditions for hot water applications and space heating in hotels and multi-family homes, hospitals, nursing homes and sport halls as well as in commercial and industrial building. However, in situ real performance data for collective solar water heating systems has not been extensively outlined. This paper focuses on the study of real energy performances of a collective solar water heating system using the remote monitoring technique in Algerian climatic conditions. This is to ensure proper operation of the system at any time, determine the system performance and to check to what extent solar performance guarantee can be achieved. The measurements are performed on an active indirect heating system of 12 m2 flat plate collector’s surface installed in Algiers and equipped with a various sensors. The sensors transmit measurements to a local station which controls the pumps, valves, electrical auxiliaries, etc. The simulation of the installation was developed using the software SOLO 2000. The system provides a yearly solar yield of 6277.5 KWh for an estimated annual need of 7896 kWh; the yearly average solar cover rate amounted to 79.5%. The productivity is in the order of 523.13 kWh / m²/year. Simulation results are compared to measured results and to guaranteed solar performances. The remote monitoring shows that 90% of the expected solar results can be easy guaranteed on a long period. Furthermore, the installed remote monitoring unit was able to detect some dysfunctions. It follows that remote monitoring is an important tool in energy management of some building equipment.

Keywords: large-scale solar water heater, real energy performance, remote monitoring, solar performance guarantee, tool to promote solar water heater

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Authors: Tingke Wu, Man Yuan

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“National Territorial Planning (2016-2030)” was issued by the State Council of China in 2017. As an important initiative of putting it into effect, territorial planning at provincial level makes overall arrangement of territorial development, resources and environment protection, comprehensive renovation and security system construction. Hubei province, as the pivot of the “Rise of Central China” national strategy, is now confronted with great opportunities and challenges in territorial development, protection, and renovation. Territorial spatial pattern experiences long time evolution, influenced by multiple internal and external driving forces. It is not clear what are the main causes of its formation and what are effective ways of optimizing it. By analyzing land use data in 2016, this paper reveals present status of territory in Hubei. Combined with economic and social data and construction information, driving forces of territorial spatial pattern are then analyzed. Research demonstrates that the three types of territorial space aggregate distinctively. The four aspects of driving forces include natural background which sets the stage for main functions, population and economic factors which generate agglomeration effect, transportation infrastructure construction which leads to axial expansion and significant provincial strategies which encourage the established path. On this basis, targeted strategies for optimizing territory spatial pattern are then put forward. Hierarchical protection pattern should be established based on development intensity control as respect for nature. By optimizing the layout of population and industry and improving the transportation network, polycentric network-based development pattern could be established. These findings provide basis for Hubei Territorial Planning, and reference for future territorial planning in other provinces.

Keywords: driving forces, Hubei, optimizing strategies, spatial pattern, territory

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Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Hekmat R. Madian, Sherif A. El-Safty, Mohamed A. Shenashen

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After the 2003 prohibition on employing TBT-based antifouling coatings, polysiloxane antifouling nano-coatings have gained in popularity as environmentally friendly and cost-effective replacements. A series of non-toxic polydimethylsiloxane nanocomposites filled with nanosheets of graphene oxide (GO) decorated with magnetite nanospheres (GO-Fe₃O₄ nanospheres) were developed and cured via a catalytic hydrosilation method. Various GO-Fe₃O₄ hybrid concentrations were mixed with the silicone resin via solution casting technique to evaluate the structure–property connection. To generate GO nanosheets, a modified Hummers method was applied. A simple co-precipitation method was used to make spherical magnetite particles under inert nitrogen. Hybrid GO-Fe₃O₄ composite fillers were developed by a simple ultrasonication method. Superhydrophobic PDMS/GO-Fe₃O₄ nanocomposite surface with a micro/nano-roughness, reduced surface-free energy (SFE), high fouling release (FR) efficiency was achieved. The physical, mechanical, and anticorrosive features of the virgin and GO-Fe₃O₄ filled nanocomposites were investigated. The synergistic effects of GO-Fe₃O4 hybrid's well-dispersion on the water-repellency and surface topological roughness of the PDMS/GO-Fe₃O₄ nanopaints were extensively studied. The addition of the GO-Fe₃O₄ hybrid fillers till 1 wt.% could increase the coating's water contact angle (158°±2°), minimize its SFE to 12.06 mN/m, develop outstanding micro/nano-roughness, and improve its bulk mechanical and anticorrosion properties. Several microorganisms were employed for examining the fouling-resistance of the coated specimens for 1 month. Silicone coatings filled with 1 wt.% GO-Fe₃O₄ nanofiller showed the least biodegradability% among all the tested microorganisms. Whereas GO-Fe₃O4 with 5 wt.% nanofiller possessed the highest biodegradability% potency by all the microorganisms. We successfully developed non-toxic and low cost nanostructured FR composite coating with high antifouling-resistance, reproducible superhydrophobic character, and enhanced service-time for maritime navigation.

Keywords: silicone antifouling, environmentally friendly, nanocomposites, nanofillers, fouling repellency, hydrophobicity

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Authors: Ana Maria Reis D'Azevedo Breda, Catarina Maria Neto da Cruz

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The Japanese art of origami provides a rich context for designing exploratory mathematical activities for children and young people. By folding a simple sheet of paper, fascinating and surprising planar and spatial configurations emerge. Equally surprising is the unfolding process, which also produces striking patterns. The procedure of folding, unfolding, and folding again allows the exploration of interesting geometric patterns. When adequately and systematically done, we may deduce some of the mathematical rules ruling origami. As the child/youth folds the sheet of paper repeatedly, he can physically observe how the forms he obtains are transformed and how they relate to the pattern of the corresponding unfolding, creating space for the understanding/discovery of mathematical principles regulating the folding-unfolding process. As part of a 2023 Summer Academy organized by a Portuguese university, a session entitled “Folding, Thinking and Generalizing” took place. Twenty-three students attended the session, all enrolled in the 2nd cycle of Portuguese Basic Education and aged between 10 and 12 years old. The main focus of this session was to foster the development of critical cognitive and socio-emotional skills among these young learners using origami. These skills included creativity, critical analysis, mathematical reasoning, collaboration, and communication. Employing a qualitative, descriptive, and interpretative analysis of data collected during the session through field notes and students’ written productions, our findings reveal that structured origami-based activities not only promote student engagement with mathematical concepts in a playful and interactive but also facilitate the development of socio-emotional skills, which include collaboration and effective communication between participants. This research highlights the value of integrating origami into educational practices, highlighting its role in supporting comprehensive cognitive and emotional learning experiences.

Keywords: skills, origami rules, active learning, hands-on activities

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Authors: Manisha Massey, Mariette Berndsen, Helen McLaren

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The existing body of literature concerning the incidence, prevalence, and experiences of childhood sexual abuse (CSA) lacked cultural inclusivity, primarily reflecting Euro-centric perspectives. This study investigated and reviewed the existing literature to understand the experiences of women of color from South Asia, addressing the gap in understanding how culture and diversity impact CSA. While individualist cultures emphasize autonomy, collectivist societies prioritize interdependence. South Asia's diverse intersections, including gender, caste, religion, and class, have intensified child sexual exploitation, challenging assumed homogeneity and safety. Additionally, the power exploitation in the space of abuse and grooming supplementing with the prevalence of honor violence makes disclosures of sexual abuse for children daunting and unsafe in these cultures. This scoping review examined the connection between CSA, psychological trauma, re-traumatization, and shame among adult South Asian women from India, Pakistan, and Bangladesh. Despite distinct borders, these countries share historical, linguistic, and traditional ties. Following PRISMA guidelines, the review employed thematic analysis. Findings underscored cultural factors' influence on CSA incidence, help-seeking barriers, and treatment challenges. The pivotal role of shame (sharam) and honor (izzat) in disclosure and healing processes was highlighted. The study emphasized the need for culturally sensitive interventions while noting limited literature on re-traumatisation. Incorporating a culturally informed perspective, this research aims to decolonize trauma therapy by contributing to the CSA discourse, shedding light on its intricate interaction with trauma, shame, and healing among South Asian women.

Keywords: Childhood sexual abuse, decolonizing psychology, trauma, re-trauma, shame

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Authors: S. Jayalakshmi, Gayathri S., Subiksa V., Nithyasri P., Agasthiya

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Paleochannels are the buried part of an active river system which was separated from the active river channel by the process of cutoff or abandonment during the dynamic evolution of the active river. Over time, they are filled by young unconsolidated or semi-consolidated sediments. Additionally, it is impacted by geo morphological influences, lineament alterations, and other factors. The primary goal of this study is to identify the paleochannels in Periyar river basin for the year 2023. Those channels has a high probability in the presence of natural resources, including gold, platinum,tin,an duranium. Numerous techniques are used to map the paleochannel. Using the optical data, Satellite images were collected from various sources, which comprises multispectral satellite images from which indices such as Normalized Difference Vegetation Index (NDVI),Normalized Difference Water Index (NDWI), Soil Adjusted Vegetative Index (SAVI) and thematic layers such as Lithology, Stream Network, Lineament were prepared. Weights are assigned to each layer based on its importance, and overlay analysis has done, which concluded that the northwest region of the area has shown some paleochannel patterns. The results were cross-verified using the results obtained using microwave data. Using Sentinel data, Synthetic Aperture Radar (SAR) Image was extracted from European Space Agency (ESA) portal, pre-processed it using SNAP 6.0. In addition to that, Polarimetric decomposition technique has incorporated to detect the paleochannels based on its scattering property. Further, Principal component analysis has done for enhanced output imagery. Results obtained from optical and microwave radar data were compared and the location of paleochannels were detected. It resulted six paleochannels in the study area out of which three paleochannels were validated with the existing data published by Department of Geology and Environmental Science, Kerala. The other three paleochannels were newly detected with the help of SAR image.

Keywords: paleochannels, optical data, SAR image, SNAP

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Authors: Paul Lam, Chi Him Chan, Alan Tse

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Language laboratories have been widely used in language learning, starting in the middle of the last century as one of the earliest forms of educational technology. They are designed to assist students’ language learning with technological innovations. Traditional language laboratories provide individual workstations that allow students to access multimedia language resources. In this type of facility, students can train their listening and speaking abilities, and teachers can also assess the performance of an individual student. Although such a setting promotes a student-centered pedagogy by encouraging students to work at their own pace and according to their own needs, it still favours a traditional, behaviourist language learning pedagogy which focuses on repetitive drilling. The change of pedagogies poses challenges to both the teachers and the facilities. The peer-learning pedagogy advocates that language learning should focus on the social aspect, which emphasizes the importance of everyday communication in language learning. The self-access, individual workstation language laboratories may not be able to provide the flexibility for interaction in the new pedagogies. Modern advancement in technology is another factor that drove our language laboratory renovation. In particular, mobile and wireless technology enabled the use of smaller and more flexible devices, making possible much clever use of space. The Chinese University of Hong Kong (CUHK) renovated nine existing language laboratories to provide lighter and more advanced equipment, movable tables, and round desks. These facilities allow more flexibility and encourage students’ interaction. It is believed that the renovated language laboratories can serve different peer learning activities and thus support peer-learning pedagogies in language teaching and learning. A survey has been conducted to collect comments from the teachers who have used the renovated language laboratories and received forty-four response. The teachers’ comments reveal that they experienced different challenges in using the renovated language laboratories, and there is a need to provide guidance to teachers during the technological and pedagogical transition. For example, teachers need instruction on using the newly installed devices such as touch-monitor and visualizer. They also need advice on planning new teaching and learning activities. Nevertheless, teachers appreciated that the renovated language laboratories are flexible and provide more spaces for different learning activities.

Keywords: language laboratories, language learning, peer-learning, student interaction

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Authors: M. A. Hashem, I. Jahan

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The experiment was conducted to find out the effect of different levels of Pomegranate (Punica granatum) extract and synthetic antioxidant BHA (Beta Hydroxyl Anisole) on fresh and preserved beef meatballs in order to make functional food. For this purpose, ground beef samples were divided into five treatment groups. They were treated as control group, 0.1% synthetic antioxidant group, 0.1%, 0.2% and 0.3% pomegranate extract group as T1, T2, T3, T4 and T5 respectively. Proximate analysis, sensory tests (color, flavor, tenderness, juiciness, overall acceptability), cooking loss, pH value, free fatty acids (FFA), thiobarbituric acid values (TBARS), peroxide value (POV) and microbiological examination were determined in order to evaluate the effect of pomegranate extract as natural antioxidant and antimicrobial activities compared to BHA (Beta Hydroxyl Anisole) at first day before freezing and for maintaining meatballs qualities on the shelf life of beef meat balls stored for 60 days under frozen condition. Freezing temperature was -20˚C. Days of intervals of experiment were on 0, 15th, 30th and 60th days. Dry matter content of all the treatment groups differ significantly (p<0.05). On the contrary, DM content increased significantly (p<0.05) with the advancement of different days of intervals. CP content of all the treatments were increased significantly (p<0.05) among the different treatment groups. EE and Ash content were decreased significantly (p<0.05) at different treatment levels. FFA values, TBARS, POV were decreased significantly (p<0.05) at different treatment levels. Color, odor, tenderness, juiciness, overall acceptability decreased significantly (p<0.05) at different days of intervals. Raw PH, cooked pH were increased at different treatment levels significantly (p<0.05). The cooking loss (%) at different treatment levels were differ significantly (p<0.05). TVC (logCFU/g), TCC (logCFU/g) and TYMC (logCFU/g) was decreased significantly (p<0.05) at different treatment levels and at different days of intervals comparison to control. Considering CP, tenderness, juiciness, overall acceptability, cooking loss, FFA, POV, TBARS value and microbial analysis it can be concluded that pomegranate extract at 0.1%, 0.2% and 0.3% can be used instead of synthetic antioxidant BHA in beef meatballs. On the basis of sensory evaluation, nutrient quality, physicochemical properties, biochemical analysis and microbial analysis 0.3% Pomegranate extract can be recommended for formulation of value added beef meatball enriched with natural antioxidant.

Keywords: antioxidant, pomegranate, BHA, value added meat products

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Authors: Esther Pearl Palmer

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Driven by the increased pressure on Higher Education Institutions (HEIs) to produce work-ready graduates for the modern world of work, this study reflects on triad teaching and learning practices to increase student engagement and employability. In the South African higher education context, the employability of graduates is imperative in strengthening the country’s economy and in increasing competitiveness. Within this context, the field of Human Resource Management (HRM) calls for innovative methods and approaches to teaching and learning and assessing the skills and competencies of graduates to render them employable. Digital competency in Human Resource Information Systems (HRIS) is an important component and prerequisite for employment in HRM. The purpose of this research is to reflect on the subject HRIS developed by lecturers at the Central University of Technology, Free State (CUT), with the intention to actively engage students in real-world learning activities and increase their employability. The Enrichment Triad Model (ETM) was used as theoretical framework to develop the subject as it supports a triad teaching and learning approach to education. It is, furthermore, an inter-structured model that supports collaboration between industry, academics and students. The study follows a mixed-method approach to reflect on the learning experiences of the industry, academics and students in the subject field over the past three years. This paper is a work in progress and seeks to broaden the scope of extant studies about student engagement in work-related learning to increase employability. Based on the ETM as theoretical framework and pedagogical practice, this paper proposes that following a triad teaching and learning approach will increase work-related skills of students. Findings from the study show that students, academics and industry alike regard educational opportunities that incorporate active learning experiences with the world of work enhances student engagement in learning and renders them more employable.

Keywords: digital competence, enriched triad model, human resource information systems, student engagement, triad pedagogy.

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Authors: Wusu Conteh

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Since the 1990s, neo-liberalization has become a global agenda. The free market ushered in an unprecedented drive by Multinational Corporations (MNCs) to secure mineral rights in resource-rich countries. Several governments in the Global South implemented a liberalized mining policy with support from the International Financial Institutions (IFIs). MNCs have maintained that voluntary Corporate Social Responsibility (CSR) has engendered socio-economic development in mining-affected communities. However, most resource-rich countries are struggling to transform the resources into sustainable socio-economic development. They are trapped in what has been widely described as the ‘resource curse.’ In an attempt to address this resource conundrum, the African Mining Vision (AMV) of 2009 developed a model on resource governance. The advent of the AMV has engendered the introduction of mandatory community development agreement (CDA) into the legal framework of many countries in Africa. In 2009, Sierra Leone enacted the Mines and Minerals Act that obligates mining companies to invest in Primary Host Communities. The study employs interviews and field observation techniques to explicate the dynamics of the CDA program. A total of 25 respondents -government officials, NGOs/CSOs and community stakeholders were interviewed. The study focuses on a case study of the Sierra Rutile CDA program in Sierra Leone. Extant scholarly works have extensively explored the resource curse and voluntary CSR. There are limited studies to uncover the mandatory CDA and its impact on socio-economic development in mining-affected communities. Thus, the purpose of this study is to explicate the impact of the CDA in Sierra Leone. Using the theory of change helps to understand how the availability of mandatory funds can empower communities to take an active part in decision making related to the development of the communities. The results show that the CDA has engendered a predictable fund for community development. It has also empowered ordinary members of the community to determine the development program. However, the CDA has created a new ground for contestations between the pre-existing local governance structure (traditional authority) and the newly created community development committee (CDC) that is headed by an ordinary member of the community.

Keywords: community development agreement, impact, mandatory, participation

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Authors: Louis Ngai Yuen Wong, Varun Maruvanchery

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The Bukit Timah Granite, which is a major rock formation in Singapore, encompasses different rock types such as granite, adamellite, and granodiorite with various hybrid rocks. The present study focuses on the Central Singapore Granite found in the Mandai area. Even within this small aerial extent, lithological variations with respect to the composition, texture as well as the grain size have been recognized in this igneous body. Over the years, the research effort on the Bukit Timah Granite has been focused on achieving a better understanding of its engineering properties in association with civil engineering projects. To our best understanding, a few types of research attempted to systematically investigate the influence of grain size, mineral composition, texture etc. on the strength of Bukit Timah Granite rocks in a comprehensive manner. In typical local industry practices, the different lithological varieties are not differentiated, but all are grouped under Bukit Timah Granite during core logging and the subsequent determination of engineering properties. To address such a major gap in the local engineering geological practice, a preliminary study is conducted on the variations of uniaxial compressive strength (UCS) in seven distinctly different lithological varieties found in the Bukit Timah Granite. Other physical properties including Young’s modulus, P-wave velocity and dry density determined from laboratory testing will also be discussed. The study is supplemented by a petrographical thin section examination. In addition, the specimen failure mode is classified and further correlated with the lithological varieties by carefully observing the details of crack initiation, propagation and coalescence processes in the specimens undergoing loading tests using a high-speed camera. The outcome of this research, which is the first of its type in Singapore, will have a direct implication on the sampling and design practices in the field of civil engineering and particularly underground space development in Singapore.

Keywords: Bukit Timah Granite, lithological variety, thin section study, high speed video, failure mode

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Authors: Yan Zhang, Felix Kin Peng Hui, Colin Duffield, Caroline X. Gao

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In post-pandemic Australia, it is unclear how building occupant have changed their behaviour in their interaction with buildings and other occupants. This research provides information on occupant behaviour change compared to before the pandemic and examines the predictors for those behaviour changes. This paper analyses survey responses from 2298 building occupants in Melbourne to investigate occupant behaviour change and determinants for those changes one year after the pandemic in Australia. The behaviour changes were grouped into three categories based on respiratory infection routes: (1) fomite: hand-shaking and hand hygiene behaviours; (2) airborne: individual interventions to indoor air quality such as face masking, window openings for occupants working in naturally ventilated space; (3) droplets: social distancing, reducing working hours in the workplace. The survey shows that the pandemic has significantly changed occupants' behaviour in all three categories compared to before the pandemic. The changes are significantly associated with occupants' perceived indoor air quality, indoor environmental cleanliness, and occupant density, demonstrating their growing awareness of respiratory infection risk that influences their health behaviours. The two most significant factors identified from multivariate regressions to drive the behaviour change include occupant risk perception of respiratory infections at the workplace and their observed co-worker's behaviour change. Based on the survey results, the paper provides adjusted estimates for related occupant behaviour parameters. The study also discusses alternatives for managing window operations in naturally ventilated buildings to improve occupant satisfaction. This paper could help Building Managers, and Building Designers understand occupant behaviour change to improve building operations and new building design to enhance occupant experience. Also, building energy modellers and risk assessors may use the findings to adjust occupant behaviour-related parameters to improve the models. The findings contribute to the knowledge of Human-Building Interaction.

Keywords: human-building interaction, risk perception, occupant behaviour, IAQ, COVID-19

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Authors: Ju-Hong Lee, Ching-Wei Liao

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Owing to close antenna spacing between antenna sensors within a compact space, a part of data in one antenna sensor would outflow to other antenna sensors when the antenna sensors in an antenna array operate simultaneously. This phenomenon is called mutual coupling effect (MCE). It has been shown that the performance of antenna array systems can be degraded when the antenna sensors are in close proximity. Especially, in a systems equipped with massive antenna sensors, the degradation of beamforming performance due to the MCE is significantly inevitable. Moreover, it has been shown that even a small angle error between the true direction angle of the desired signal and the steering angle deteriorates the effectiveness of an array beamforming system. However, the true direction vector of the desired signal may not be exactly known in some applications, e.g., the application in land mobile-cellular wireless systems. Therefore, it is worth developing robust techniques to deal with the problem due to the MCE and steering angle error for array beamforming systems. In this paper, we present an efficient technique for performing adaptive beamforming with robust capabilities against the MCE and the steering angle error. Only the data vector received by an antenna array is required by the proposed technique. By using the received array data vector, a correlation matrix is constructed to replace the original correlation matrix associated with the received array data vector. Then, the mutual coupling matrix due to the MCE on the antenna array is estimated through a recursive algorithm. An appropriate estimate of the direction angle of the desired signal can also be obtained during the recursive process. Based on the estimated mutual coupling matrix, the estimated direction angle, and the reconstructed correlation matrix, the proposed technique can effectively cure the performance degradation due to steering angle error and MCE. The novelty of the proposed technique is that the implementation procedure is very simple and the resulting adaptive beamforming performance is satisfactory. Simulation results show that the proposed technique provides much better beamforming performance without requiring complicated complexity as compared with the existing robust techniques.

Keywords: adaptive beamforming, mutual coupling effect, recursive algorithm, steering angle error

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Authors: Mehrosadat Mirmohammadi, Sara Taghdisi, Ali Padash, Mohammad Hossein Pazandeh

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Gossypol, a yellowish anti-nutritional compound found in cotton plants, exists in various plant parts, including seeds, husks, leaves, and stems. Chemically, gossypol is a potent polyphenolic aldehyde with antioxidant and therapeutic properties. However, its free form can be toxic, posing risks to both humans and animals. Initially, we extracted gossypol from cotton seeds using n-hexane as a solvent (yield: 84.0 ± 4.0%). We also obtained cotton seed and cotton boll extracts via Soxhlet extraction (25:75 hydroalcoholic ratio). These extracts, combined with cornstarch, formed four herbal medicinal formulations. Ethical approval allowed us to investigate their effects on Leishmania-caused skin wounds, comparing them to glucantime (local ampoule). Herbal formulas outperformed the control group (ethanol only) in wound treatment (p-value 0.05). The average wound diameter after two months did not significantly differ between plant extract ointments and topical glucantime. Notably, cotton boll extract with 1% extra gossypol crystal showed the best therapeutic effect. We extracted gossypol from cotton seeds using n-hexane via Soxhlet extraction. Saponification, acidification, and recrystallization steps followed. FTIR, UV-Vis, and HPLC analyses confirmed the product’s identity. Herbal medicines from cotton seeds effectively treated chronic wounds compared to the ethanol-only control group. Wound diameter differed significantly between extract ointments and glucantime injections. It seems that due to the presence of large amounts of fat in the oil, the extraction of gossypol from it faces many obstacles. The extraction of this compound with our technique showed that extraction from oil has a higher efficiency, perhaps because of the preparation of oil by cold pressing method, the possibility of losing this compound is much less than when extraction is done with Soxhlet. On the other hand, the gossypol in the oil is mostly bound to the protein, which somehow protects the gossypol until the last stage of the extraction process. Since this compound is very sensitive to light and heat, it was extracted as a derivative with acetic acid. Also, in the treatment section, it was found that the ointment prepared with the extract is more effective and Gossypol is one of the effective ingredients in the treatment. Therefore, gossypol can be extracted from the oil and added to the extract from which gossypol has been extracted to make an effective medicine with a certain dose.

Keywords: cottonseed, glucantime, gossypol, leishmaniasis

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Authors: Namrata Khatri

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The rapid growth of cities is transforming the urban environment and posing significant challenges for environmental quality. This study examines the urban environment of Belagavi in Karnataka, India, using geostatistical methods to assess the spatial pattern and land use distribution of the city and to evaluate the quality of the urban environment. The study is driven by the necessity to assess the environmental impact of urbanisation. Satellite data was utilised to derive information on land use and land cover. The investigation revealed that land use had changed significantly over time, with a drop in plant cover and an increase in built-up areas. High-resolution satellite data was also utilised to map the city's open areas and gardens. GIS-based research was used to assess public green space accessibility and to identify regions with inadequate waste management practises. The findings revealed that garbage collection and disposal techniques in specific areas of the city needed to be improved. Moreover, the study evaluated the city's thermal environment using Landsat 8 land surface temperature (LST) data. The investigation found that built-up regions had higher LST values than green areas, pointing to the city's urban heat island (UHI) impact. The study's conclusions have far-reaching ramifications for urban planners and politicians in Belgaum and other similar cities. The findings may be utilised to create sustainable urban planning strategies that address the environmental effect of urbanisation while also improving the quality of life for city dwellers. Satellite data and high-resolution satellite pictures were gathered for the study, and remote sensing and GIS tools were utilised to process and analyse the data. Ground truthing surveys were also carried out to confirm the accuracy of the remote sensing and GIS-based data. Overall, this study provides a complete assessment of Belgaum's environmental quality and emphasizes the potential of remote sensing and geographic information systems (GIS) approaches in environmental assessment and management.

Keywords: environmental quality, UEQ, remote sensing, GIS

Procedia PDF Downloads 54

Authors: Pamphile Ndagijimana, Xuejiao Liu, Zhiwei Li, Yin Wang

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The valorization of plastic wastes, as a mitigation strategy, is attracting the researchers’ attention since these wastes have raised serious environmental concerns. Plastic wastes have been reported to adsorb the organic pollutants in the water environment and to be the main vector of those pollutants in the aquatic environment, especially dyes, as a serious water pollution concern. Recycling technologies of plastic wastes such as landfills, incineration, and energy recovery have been adopted to manage those wastes before getting exposed to the environment. However, they are far from being widely accepted due to their related environmental pollution, lack of space for the landfill as well as high cost. Therefore, modification is necessary for green plastic adsorbent in water applications. Current routes for plastic modification into adsorbents are based on the combustion method, but they have weaknesses of air pollution as well as high cost. Thus, the green strategy for plastic modification into adsorbents is highly required. Furthermore, recent researchers recommended that if plastic wastes are combined with other solid carbon materials, they could promote their application in water treatment. Herein, we present new insight into using plastic waste-based materials as future green adsorbents. Magnetic plastic-reduced graphene oxide (MPrGO) composite was synthesized by cross-linking method and applied in removing methylene blue (MB) from an aqueous solution. Furthermore, the following advantages have been achieved: (i) The density of plastic and reduced graphene oxide were enhanced, (ii) no second pollution of black color in solution, (iii) small amount of graphene oxide (1%) was linked on 10g of plastic waste, and the composite presented the high removal efficiency, (iv) easy recovery of adsorbent from water. The low concentration of MB (10-30mg/L) was all removed by 0.3g of MPrGO. Different characterization techniques such as XRD, SEM, FTIR, BET, XPS, and Raman spectroscopy were performed, and the results confirmed a conjugation between plastic waste and graphene oxide. This MPrGO composite presented a good prospect for the valorization of plastic waste, and it is a promising composite material in water treatment.

Keywords: plastic waste, graphene oxide, dye, adsorption

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Authors: Fang Liu, JiaJia Yao, GuanLin Wu, ZuMaoLi, XueYan Yang, HePeng Zhang, ZhiPeng Sun, JunShuai Xue

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The explosive increasing needs of data processing and information storage strongly drive the advancement of the binary logic system to multiple-valued logic system. Inherent negative differential resistance characteristic, ultra-high-speed switching time, and robust anti-irradiation capability make III-nitride resonant tunneling diode one of the most promising candidates for multi-valued logic devices. Here we report the monolithic integration of GaN resonant tunneling diodes in series to realize multiple negative differential resistance regions, obtaining at least three stable operating states. A multiply-by-three circuit is achieved by this combination, increasing the frequency of the input triangular wave from f0 to 3f0. The resonant tunneling diodes are grown by plasma-assistedmolecular beam epitaxy on free-standing c-plane GaN substrates, comprising double barriers and a single quantum well both at the atomic level. Device with a peak current density of 183kA/cm² in conjunction with a peak-to-valley current ratio (PVCR) of 2.07 is observed, which is the best result reported in nitride-based resonant tunneling diodes. Microwave oscillation event at room temperature was discovered with a fundamental frequency of 0.31GHz and an output power of 5.37μW, verifying the high repeatability and robustness of our device. The switching behavior measurement was successfully carried out, featuring rise and fall times in the order of picoseconds, which can be used in high-speed digital circuits. Limited by the measuring equipment and the layer structure, the switching time can be further improved. In general, this article presents a novel nitride device with multiple negative differential regions driven by the resonant tunneling mechanism, which can be used in high-speed multiple value logic field with reduced circuit complexity, demonstrating a new solution of nitride devices to break through the limitations of binary logic.

Keywords: GaN resonant tunneling diode, negative differential resistance, multiple-valued logic system, switching time, peak-to-valley current ratio

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Authors: Deniz Guven, Wil Ward, Jinming Duan, Li Bai

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Over the past two decades or so, Optical Coherence Tomography (OCT) has been used to diagnose retina and optic nerve diseases. The retinal nerve fibre layer, for example, is a powerful diagnostic marker for detecting and staging glaucoma. With the advances in optical imaging hardware, the adoption of OCT is now commonplace in clinics. More and more OCT images are being generated, and for these OCT images to have clinical applicability, accurate automated OCT image segmentation software is needed. Oct image segmentation is still an active research area, as OCT images are inherently noisy, with the multiplicative speckling noise. Simple edge detection algorithms are unsuitable for detecting retinal layer boundaries in OCT images. Intensity fluctuation, motion artefact, and the presence of blood vessels also decrease further OCT image quality. In this paper, we introduce a new method for segmenting three-dimensional (3D) OCT images. This involves the use of a Kalman filter, which is commonly used in computer vision for object tracking. The Kalman filter is applied to the 3D OCT image volume to track the retinal layer boundaries through the slices within the volume and thus segmenting the 3D image. Specifically, after some pre-processing of the OCT images, points on the retinal layer boundaries in the first image are identified, and curve fitting is applied to them such that the layer boundaries can be represented by the coefficients of the curve equations. These coefficients then form the state space for the Kalman Filter. The filter then produces an optimal estimate of the current state of the system by updating its previous state using the measurements available in the form of a feedback control loop. The results show that the algorithm can be used to segment the retinal layers in OCT images. One of the limitations of the current algorithm is that the curve representation of the retinal layer boundary does not work well when the layer boundary is split into two, e.g., at the optic nerve, the layer boundary split into two. This maybe resolved by using a different approach to representing the boundaries, such as b-splines or level sets. The use of a Kalman filter shows promise to developing accurate and effective 3D OCT segmentation methods.

Keywords: optical coherence tomography, image segmentation, Kalman filter, object tracking

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Authors: Pallavi Gajjar, Vinayak Malhotra

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Rockets have been known to have played a predominant role in spacecraft propulsion. The quintessential aspect of combustion-related requirements of a rocket engine is the minimization of the surrounding risks/hazards. Over time, it has become imperative to understand the combustion rate variation in presence of external energy source(s). Rocket propulsion represents a special domain of chemical propulsion assisted by high speed flows in presence of acoustics and thermal source(s). Jet noise leads to a significant loss of resources and every year a huge amount of financial aid is spent to prevent it. External heat source(s) induce high possibility of fire risk/hazards which can sufficiently endanger the operation of a space vehicle. Appreciable work had been done with justifiable simplification and emphasis on the linear variation of external energy source(s), which yields good physical insight but does not cater to accurate predictions. Present work experimentally attempts to understand the correlation between inter-energy conversions with the non-linear placement of external energy source(s). The work is motivated by the need to have better fire safety and enhanced combustion. The specific objectives of the work are a) To interpret the related energy transfer for combustion in presence of alternate external energy source(s) viz., thermal and acoustic, b) To fundamentally understand the role of key controlling parameters viz., separation distance, the number of the source(s), selected configurations and their non-linear variation to resemble real-life cases. An experimental setup was prepared using incense sticks as potential fuel and paraffin wax candles as the external energy source(s). The acoustics was generated using frequency generator, and source(s) were placed at selected locations. Non-equidistant parametric experimentation was carried out, and the effects were noted on regression rate changes. The results are expected to be very helpful in offering a new perspective into futuristic rocket designs and safety.

Keywords: combustion, acoustic energy, external energy sources, regression rate

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Authors: Priscilla Echeverria

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For us grown up in neoliberal societies, it is not always clear that we have not only incorporated an economic logic into our subjectivities, but a technical reason, an instrumental way of relationship with the environment inspired in a control interest that constantly dehumanizes us as takes away our capacity of action, becoming mere objects or bureaucrats, stripped of our citizen dimension to participate in social and political issues responsibly and creatively. To restore the capacity of action -agency- is urgent in our societies to strengthen better democracies. On this, the formal educational system plays a crucial role, which in turn needs teachers prepared to understand their role as integral educators instead of mere curriculum managers. For this reason, initial teacher formation (ITF) programs must assume the responsibility of helping them to develop an ethical/political/epistemic pedagogical agency to deal with a technical school culture and, in turn, able to relate to their students in democratic ways to help them to develop their agency capacities. By highlighting a perspective of education as the opposite of technocracy and bureaucracy, this talk precisely addresses ITF as a crucial and formative space to restore a perspective of what a critical education can look like, enabling pedagogy students with pedagogical agency capacities to, in turn, allow their future students to develop it. This discussion is part of my doctoral research, "The importance of developing the capacity for ethical-political-epistemic agency in novice teachers during initial teacher formation to contribute to social justice", which I currently develop in the Educational Research program of the University of Lancaster, United Kingdom, as a Conicyt fellow for the 2019 cohort. This presentation specifically offers preliminary results of the analysis of critical incidents as a research methodological tool to analyse the capacity of pedagogical agency deployed by novice teachers in their first pedagogical experiences in the Chilean context.

Keywords: initial teacher formation, pedagogical agency, pedagogical interaction, hidden curriculum, critical pedagogy, social justice

Procedia PDF Downloads 85