Search results for: transcranial direct current stimulation

Authors: Young Man Cho, Sang Hyun Kim

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Even though various management practices such as sediment dredging were attempted to improve water quality of Dongcheon located in Busan, the environmental condition of this stream was deteriorated. Therefore, Busan metropolitan city had pumped and diverted sea water to upstream of Dongcheon for several years. This study explored hydraulic characteristics of Dongcheon to configure the best management practice for ecological restoration and water quality improvement of a man-made urban stream. Intensive field investigation indicates that average flow velocities at depths of 20% and 80% from the water surface ranged 5 to 10 cm/s and 2 to 5 cm/s, respectively. Concentrations of dissolved oxygen for all depths were less than 0.25 mg/l during low tidal period. Even though density difference can be found along stream depth, density current seems rarely generated in Dongcheon. Short period of high tidal portion and shallow depths are responsible for well-mixing nature of Doncheon.

Keywords: hydraulic, tidal river, density current, sea water

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Authors: Anastasios Charisis, Evangelos Kaisar, Steven Spana, Lili Du

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Logistics play a vital role in the prosperity of today’s cities, but current urban logistics practices are proving problematic, causing negative effects such as traffic congestion and environmental impacts. This paper proposes an alternative urban logistics system, leasing hubs inside cities for designated time intervals, and using handcarts for last-mile deliveries. A mathematical model for selecting the locations of hubs and allocating customers, while also scheduling the optimal times during the day for leasing hubs is developed. The proposed model is compared to current delivery methods requiring door-to-door truck deliveries. It is shown that truck traveled distances decrease by more than 60%. In addition, analysis shows that in certain conditions the approach can be economically competitive and successfully applied to address real problems.

Keywords: hub location, last-mile, logistics, optimization

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Authors: Farzaneh Shayeganfar, Ali Ramazani

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Exciton (strong electronic interaction of electron-hole) and hot carriers created by surface plasmon polaritons has been demonstrated in nanoscale optoelectronic devices, enhancing the photoresponse of the system. Herein, we employ a quantum framework to consider coupled exciton- hot carriers effects on photovoltaiv energy distribution, scattering process, polarizability and light emission of 2D-semicnductor. We use density functional theory (DFT) to design computationally a semi-functionalized 2D honeycomb silicon boride (SiB) monolayer with H atoms, suitable for photovoltaics. The dynamical stability, electronic and optical properties of SiB and semi-hydrogenated SiB structures were investigated utilizing the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential. The calculated phonon dispersion shows that while an unhydrogenated SiB monolayer is dynamically unstable, surface semi-hydrogenation improves the stability of the structure and leads to a transition from metallic to semiconducting conductivity with a direct band gap of about 1.57 eV, appropriate for photovoltaic applications. The optical conductivity of this H-SiB structure, determined using the random phase approximation (RPA), shows that light adsorption should begin at the boundary of the visible range of light. Additionally, due to hydrogenation, the reflectivity spectrum declines sharply with respect to the unhydrogenated reflectivity spectrum in the IR and visible ranges of light. The energy band gap remains direct, increasing from 0.9 to 1.8 eV, upon increasing the strain from -6% (compressive) to +6% (tensile). Additionally, compressive and tensile strains lead, respectively, to red and blue shifts of optical the conductivity threshold around the visible range of light. Overall, this study suggests that H-SiB monolayers are suitable as two-dimensional solar cell materials.

Keywords: surface plasmon, hot carrier, strain engineering, valley polariton

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Authors: H. Nejadriahi

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Traditional architecture is a valuable source of inspiration, which needs to be studied and integrated in the contemporary designs for achieving an identifiable contemporary architecture. Traditional architecture of Iran is among the distinguished examples of being contextually responsive, not only by considering the environmental conditions of a region, but also in terms of respecting the socio-cultural values of its context. In order to apply these valuable features to the current designs, they need to be adapted to today's condition, needs and desires. In this paper, the main features of the traditional architecture of Iran are explained to interrogate them in the formation of a contemporary house in Tehran, Iran. Also a table is provided to compare the utilization of the traditional design concepts in the traditional houses and the contemporary example of it. It is believed that such study would increase the awareness of contemporary designers by providing them some clues on maintaining the traditional values in the current design layouts particularly in the residential sector that would ultimately improve the quality of space in the contemporary architecture.

Keywords: contemporary housing design, Iran, Tehran, traditional architecture

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Authors: Albert Herve Nkolo Mpoko

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The Foreign Direct Investment (FDI) landscape in Cameroon has garnered significant attention from both European and Asian nations due to perceived benefits such as capital infusion, technology transfer, and potential for economic expansion. However, it is noteworthy that South Africa's investment presence remains comparatively subdued in Cameroon, lagging behind that of Europe and Asia. Equally surprising is the limited footprint of Africa's economic powerhouse within other African economies. This study delved into four specific facets of South African investment in Cameroon. Initially, it focused on identifying South African companies operating within Cameroon. Subsequently, the analysis encompassed assessing the correlation between South African investment and poverty alleviation. Additionally, the study examined the nexus between South African investment and technological advancement, and underscored the significance of investment incentives in both countries Key findings of the research shed light on several crucial points. South Africa ought to reassess its economic engagement with Francophone Africa, particularly Cameroon. Despite existing policies aimed at fostering investment, there remains substantial ground to cover in this realm. The proliferation of South African enterprises in Cameroon holds the potential to ameliorate poverty and foster employment opportunities across both nations. The advent of South African firms in Cameroon can catalyse technological advancements within the region. Data collection involved surveying 100 executives from the respective administrations and conducting ten interviews. The gathered data underwent triangulation, wherein quantitative findings were juxtaposed with qualitative insights. In conclusion, the study underscores the underutilization of Cameroon by South Africa, emphasizing the untapped potential for mutual economic growth. Furthermore, it posits that the success of South Africa's multinational corporations abroad could serve as a pivotal pillar for sustaining its domestic economy.

Keywords: FDI, transfer of technology, South-South cooperation, mutual economic growth

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Authors: Fahad Alamoudi, Yaser Miaji, Fawzy Jalalah

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The growing popularity of swimming pools and other activities in the water for sport, fitness, therapy or just enjoyable relaxation have led to the increased use of swimming pools and the establishment of a variety of specific-use pools such as spa pools, Waterslides and more recently, hydrotherapy and wave pools. In this research a few simple equipments are used for test, Detect and alert for detection of water cleanness and pollution. YSI Photometer Systems, TDSTestr High model, rio 12HF, and Electrode A1. The researchers used electrolysis as a method of separating bonded elements and compounds by passing an electric current through them. The results which use 41 experiments show the higher the salt concentration, the more efficient the electrode and the smaller the gap between the plates and The lower the electrode voltage. Furthermore, it is proved that the larger the surface area, the lower the cell voltage and the higher current used the more chlorine produced.

Keywords: photometer, electrode, electrolysis, swimming pool chlorination

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Authors: Afshin Kadri

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Using Renewable Energy Resources (RES) as a type of DG unit is developing in distribution systems. The connection of these generation units to existing AC distribution systems changes the structure and some of the operational aspects of these grids. Most of the RES requires to power electronic-based interfaces for connection to AC systems. These interfaces consist of at least one DC/AC conversion unit. Nowadays, grid-connected inverters must have the required feature to support the grid under sag voltage conditions. There are two curves in these conditions that show the magnitude of the reactive component of current as a function of voltage drop value and the required minimum time value, which must be connected to the grid. This feature is named low voltage ride-through (LVRT). Implementing this feature causes problems in the operation of the inverter that increases the amplitude of high-frequency components of the injected current and working out of maximum power point in the photovoltaic panel connected inverters are some of them. The important phenomenon in these conditions is ripples in the DC bus voltage that affects the operation of the inverter directly and indirectly. The losses of DC bus capacitors which are electrolytic capacitors, cause increasing their temperature and decreasing its lifespan. In addition, if the inverter is connected to the photovoltaic panels directly and has the duty of maximum power point tracking, these ripples cause oscillations around the operating point and decrease the generating energy. Using a bidirectional converter in the DC bus, which works as a buck and boost converter and transfers the ripples to its DC bus, is the traditional method to eliminate these ripples. In spite of eliminating the ripples in the DC bus, this method cannot solve the problem of reliability because it uses an electrolytic capacitor in its DC bus. In this work, a control method is proposed which uses the bidirectional converter as the fourth leg of the inverter and eliminates the DC bus ripples using an injection of unbalanced currents into the grid. Moreover, the proposed method works based on constant power control. In this way, in addition, to supporting the amplitude of grid voltage, it stabilizes its frequency by injecting active power. Also, the proposed method can eliminate the DC bus ripples in deep voltage drops, which cause increasing the amplitude of the reference current more than the nominal current of the inverter. The amplitude of the injected current for the faulty phases in these conditions is kept at the nominal value and its phase, together with the phase and amplitude of the other phases, are adjusted, which at the end, the ripples in the DC bus are eliminated, however, the generated power decreases.

Keywords: renewable energy resources, voltage drop value, DC bus ripples, bidirectional converter

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Authors: Artem Surkov

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This work is devoted to a problem of aesthetic quality determinism in the context of contemporary art. The object of study is photography regarding as a kind of art which demands specific system of quality marking. Objective: To define aesthetic criteria in photography art. For current searching different kind of texts by such powerful authors like Clement Greenberg and Rosalind Krauss, Theodor Adorno and Herbert Marcuse, Charlott Cotton and Boris Groys, Viktor Miziano and Ekaterina Degot' were analyzed. Before all, there are two different kinds of photography: the classic art photography (by Ansel Adams) and the photography as kind of art (by Andreas Gursky). In this text we are talking about the photography as kind of art. The main principle of current searching is synthesis of two different approaches: modernism and postmodernism. This method helps us to define uniform criteria of aesthetic quality in photography as kind of art. The criteria mentioned in conclusion paragraph are: aesthetic rationality, aesthetic economy, awareness (using photographic technics or references), and intention to go beyond form, practice and method.

Keywords: aesthetic, art, criteria of quality, photography, visually

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Authors: Elsaed Elsaed

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With the constant progress in our daily lives through information and communication technology and the presence of abundant in research activities in the hardware and software associated with them, and develop and improve their performance, but still there is a need to provide all combined solutions in one business. A systematic mapping study was conducted to investigate the contributions that have been prepared, and the areas of knowledge that are explored further, and any aspects of the research used to divide the common understanding of the latest technology in software engineering education. Which, we have categorized into a well-defined engineering framework. An overview of current research topics and trends and their distribution by type of research and scope of application. In addition, the topics were grouped into groups and a list of proposed methods and frameworks and tools was used. The map shows that the current research impact is limited to a few areas of knowledge are needed to map a future path to fill the gaps in the instruction activities.

Keywords: methodological maps, engineering education program, literature survey, communication technology

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Authors: V. G. Cappellesso, D. M. G. da Silva, J. A. Arndt, N. dos Santos Petry, A. B. Masuero, D. C. C. Dal Molin

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Concrete elements are subject to cracking, which can be an access point for deleterious agents that can trigger pathological manifestations reducing the service life of these structures. Finding ways to minimize or eliminate the effects of this aggressive agents’ penetration, such as the sealing of these cracks, is a manner of contributing to the durability of these structures. The cementitious self-healing phenomenon can be classified in two different processes. The autogenous self-healing that can be defined as a natural process in which the sealing of this cracks occurs without the stimulation of external agents, meaning, without different materials being added to the mixture, while on the other hand, the autonomous seal-healing phenomenon depends on the insertion of a specific engineered material added to the cement matrix in order to promote its recovery. This work aims to evaluate the autogenous self-healing of concretes produced with different water/cement ratios and exposed to wet/dry cycles, considering two ages of crack openings, 3 days and 28 days. The self-healing phenomenon was evaluated using two techniques: crack healing measurement using ultrasonic waves and image analysis performed with an optical microscope. It is possible to observe that by both methods, it possible to observe the self-healing phenomenon of the cracks. For young ages of crack openings and lower water/cement ratios, the self-healing capacity is higher when compared to advanced ages of crack openings and higher water/cement ratios. Regardless of the crack opening age, these concretes were found to stabilize the self-healing processes after 80 days or 90 days.

Keywords: sealf-healing, autogenous, water/cement ratio, curing cycles, test methods

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Authors: N. G. Margiani, I. G. Kvartskhava, G. A. Mumladze, Z. A. Adamia

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Chemical doping with different elements and compounds at various amounts represents the most suitable approach to improve the superconducting properties of bismuth-based superconductors for technological applications. In this paper, the influence of partial substitution of Sr(BO₂)₂ for SrO on the phase formation kinetics and transport properties of (Bi,Pb)-2223 HTS has been studied for the first time. Samples with nominal composition Bi_1.7Pb_0.3Sr_2-xCa₂Cu₃O_y[Sr(BO₂)₂]_x, x=0, 0.0375, 0.075, 0.15, 0.25, were prepared by the standard solid state processing. The appropriate mixtures were calcined at 845 ^oC for 40 h. The resulting materials were pressed into pellets and annealed at 837 ^oC for 30 h in air. Superconducting properties of undoped (reference) and Sr(BO₂)₂-doped (Bi,Pb)-2223 compounds were investigated through X-ray diffraction (XRD), resistivity (ρ) and transport critical current density (J_c) measurements. The surface morphology changes in the prepared samples were examined by scanning electron microscope (SEM). XRD and J_c studies have shown that the low level Sr(BO₂)₂ doping (x=0.0375-0.075) to the Sr-site promotes the formation of high-T_c phase and leads to the enhancement of current carrying capacity in (Bi,Pb)-2223 HTS. The doped sample with x=0.0375 has the best performance compared to other prepared samples. The estimated volume fraction of (Bi,Pb)-2223 phase increases from ~25 % for reference specimen to ~70 % for x=0.0375. Moreover, strong increase in the self-field J_c value was observed for this dopant amount (J_c=340 A/cm²), compared to an undoped sample (J_c=110 A/cm²). Pronounced enhancement of superconducting properties of (Bi,Pb)-2223 superconductor can be attributed to the acceleration of high-T_c phase formation as well as the improvement of inter-grain connectivity by small amounts of Sr(BO₂)₂ dopant.

Keywords: bismuth-based superconductor, critical current density, phase formation, Sr(BO₂)₂ doping

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Authors: Jiawei Liang

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Against the backdrop of China's burgeoning migration from rural to urban areas, a demographic group has emerged in China, which is called left-behind children. Due to many reasons, including the issue of the rural-urban education gap, the education of left-behind children has been below the national education average. In this situation, the issue has attracted the attention of researchers and policymakers. In order to gain a comprehensive understanding of this issue, this paper adopts an analytical approach to studying the rural-urban education gap and left-behind children in rural China. The paper first introduces the current situation of migration, the education gap, and left-behind children within China. Then, it further explores the causes of these two questions and barriers as well as the consequences for left-behind children. Finally, the study offers some suggestions to alleviate the urban-rural gap and the current situation of education for left-behind children in rural areas, which will hopefully shed light on the issue of left-behind children in China and the urban-rural education gap.

Keywords: left-behind children, rural China, education improvement, Hukou policy, rural-urban education gap

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Authors: Masocorro Gawned, Stephen Myers, Guat Siew Chew

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Nuclear Receptors (NR) are a super family of transcription factors that play a major role in lipid and glucose metabolism in skeletal muscle. Recently, pharmacological evidence supports the view that stimulation of nuclear receptors alleviates Type 2 Diabetes (T2D). The orphan nuclear receptors (ONR) are members of the nuclear receptor (NR) superfamily whose ligands and physiological functions remain unknown. To date, no systematic studies have been carried out to screen for ONRs expressed in insulin resistant (IR) skeletal muscle cells. Therefore, in this study, we have established a model for IR by treating C2C12 skeletal muscle cells with insulin (10nM) for 48 hours. Western Blot analysis of phosphorylated AKT confirmed IR. Real-time quantitative polymerase chain reaction (qPCR) results highlighted key ONRs including NUR77 (NR4A1), NURR1 (NR4A2) and NOR1 (NR4A3) which have been associated with fatty acid oxidation regulation and glucose homeostasis. Increased mRNA expression levels of estrogen-related receptors (ERRs), REV-ERBα, NUR77, NURR1, NOR1, in insulin resistant C2C12 skeletal muscle cells, indicated that these ONRs could potentially play a pivotal regulatory role of insulin secretion in lipid metabolism. Taken together, this study has successfully contributed to the complete analysis of ONR in IR, and has filled in an important void in the study and treatment of T2D.

Keywords: type 2 diabetes, orphan nuclear receptors, transcription receptors, quantitative mRNA expression

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Authors: Yves Mann Elate Lea Mbassi, Marie Solange Evehe Bebandoue, Wilfred Fon Mbacham

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Improving the catalytic performance of enzymes has been a long-standing theme of analytical biochemistry research. Induction of peroxidase activity by metals is a common reaction in higher plants. We thought that this increase in peroxidase activity may be due, on the one hand, to the stimulation of the gene expression of these enzymes but also to a modification of their chemical reactivity following the binding of some metal ions on their active site. We tested the effect of some metal salts (MgCl₂, MnCl₂, ZnCl₂, CaCl₂ and CuSO₄) on the activity and thermostability of peroxidase A6, a thermostable peroxidase that we discovered and purified in a previous study. The chromogenic substrate used was 3,3′,5,5′-tetramethylbenzidine. Of all the metals tested for their effect on A6, only magnesium and copper had a significant effect on the activity of the enzyme at room temperature. The Mann-Whitney test shows a slight inhibitory effect of activity by the magnesium salt (P = 0.043), while the activity of the enzyme is 5 times higher in the presence of the copper salt (P = 0.002). Moreover, the thermostability of peroxidase A6 is increased when calcium and copper salts are present. The activity in the presence of CaCl₂ is 8 times higher than the residual activity of the enzyme alone after incubation at 80°C for 10 min and 35 times higher in the presence of CuSO4 under the same conditions. In addition, manganese and zinc salts slightly reduce the thermostability of the enzyme. The activity and structural stability of peroxidase A6 can clearly be activated by Cu₂+, which therefore enhance the oxidation of 3,3′,5,5′-tetramethylbenzidine, which was used in this study as a chromogenic substrate. Ca₂+ likely has a more stabilizing function for the catalytic site.

Keywords: peroxidase activity, copper ions, calcium ions, thermostability

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Authors: Tasneem Imam, Justine S. Gibson, Mohammad Foysal, Shetu B. Das, Rashed Mahmud, Suman D. Gupta, Ahasanul Hoque, Guillaume Fournie, Joerg Henning

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Commercial chicken production is an import livestock industry in Bangladesh. Antimicrobials are commonly used to control and prevent infectious diseases. It was hypothesized that inadequate biosecurity practices might promote antimicrobial usage on commercial chicken farms. A cross-sectional study was carried out to evaluate antimicrobial usage and farm biosecurity practices implemented on 57 layer and 83 broiler farms in eight sub-districts of the Chattogram district in Bangladesh. A questionnaire was used to collect data on antimicrobial usage and biosecurity practices on these farms. A causal framework was used to guide the development of a multi-level mixed-effects logistic regression analysis to evaluate the total and direct effects of practiced biosecurity management on prophylactic and therapeutic administration of antimicrobials. A total of 24 antimicrobials were administered in the current production cycle at the time of the survey. The most administered antimicrobials on layer farms were ciprofloxacin (37.0% of farms), amoxicillin (33.3%), and tiamulin (31.5%); however, on broiler farms, colistin (56.6% of farms), doxycycline (50.6%), and neomycin (38.6%) were most used. Only 15.3% of commercial farmers used antimicrobials entirely for therapeutic purposes, whereas 84.7% administered antimicrobials prophylactically. Inadequate biosecurity practices were more common among commercial broiler farmers compared to layer farmers. For example, only 2.4% of broiler farmers used footbaths before entering sheds compared to 22.2% of the layer farmers (p < 0.001). Farms that used antimicrobials only for therapeutic purposes (vs prophylactic) implemented more frequently adequate disease control measures, such as separating sick birds from healthy birds. This research highlighted that the prophylactic application of antimicrobials is often conducted to substitute poor biosecurity practices on commercial chicken farms. Awareness programs for farmers are crucial to inform them about the risk associated with antimicrobial usage and to highlight the economic benefits of implementing cost-effective biosecurity measures to control infectious poultry diseases.

Keywords: antimicrobial, biosecurity, broiler, layer

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Authors: Ranojoy Dutta

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HVAC equipment capacity has a direct impact on occupant comfort and energy consumption of a building. Glazing gains, especially in buildings with high window area, can be a significant contributor to the total peak load on the HVAC system, leading to over-sized systems that mostly operate at poor part load efficiency. In addition, radiant temperature, which largely drives occupant comfort in glazed perimeter zones, is often not effectively controlled despite the HVAC being designed to meet the air temperature set-point. This is due to short wave solar radiation transmitted through windows, that is not sensed by the thermostat until much later when the thermal mass in the room releases the absorbed solar heat to the indoor air. The implication of this phenomenon is increased cooling energy despite poor occupant comfort. EC glazing can significantly eliminate direct solar transmission through windows, reducing both the space cooling loads for the building and improving comfort for occupants near glazing. This paper will review the exact mechanism of how EC glazing would reduce the peak load under design day conditions, leading to reduced cooling capacity vs regular high-performance glazing. Since glazing heat transfer only affects the sensible load, system sizing will be evaluated both with and without the availability of a DOAS to isolate the downsizing potential of the primary cooling equipment when outdoor air is conditioned separately. Given the dynamic nature of glazing gains due to the sun’s movement, effective peak load mitigation with EC requires an automated control system that can predict solar movement and radiation levels so that the right tint state with the appropriate SHGC is utilized at any given time for a given façade orientation. Such an automated EC product will be evaluated for a prototype commercial office model situated in four distinct climate zones.

Keywords: electrochromic glazing, peak sizing, thermal comfort, glazing load

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Authors: Atef Y. Shenouda, Fei Xu

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Cu₃SbS₃ (CAS) was synthesized by direct solid-state reaction from elementary Cu, Sb, & S and hydrothermal reaction using thioacetamide (TAM). Crystal structure and morphology for the prepared phases of Cu₃SbS₃ were studied via X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The band gap energies are 2 and 2.2 eV for the prepared samples. The two samples are as anode for Na ion storage. They show high initial capacity to 490 mAh/g. Na cell prepared from TAM sample shows 280 mAh/g after 25 cycles vs. 60 mAh/g for elemental sample.

Keywords: Cu3SbS3, sodium batteries, thioacetamide, sulphur sources

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Authors: J. Kazior, A. Szewczyk-Nykiel, T. Pieczonka, M. Laska

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Aluminium alloys are an important class of engineering materials for structural applications. This is due to the fact that these alloys have many interesting properties, namely, low density, high ratio of strength to density, good thermal and electrical conductivity, good corrosion resistance as well as extensive capabilities for shaping processes. In case of classical PM technology a particular attention should be paid to the selection of appropriate parameters of compacting and sintering processes and to keeping them. The latter need arises from the high sensitivity of aluminium based alloy powders on any fluctuation of technological parameters, in particular those related to the temperature-time profile and gas flow. Only then the desired sintered compacts with residual porosity may be produced. Except high mechanical properties, the other profitable properties of almost fully dense sintered components could be expected. Among them is corrosion resistance, rarely investigated on PM aluminium alloys. Thus, in the current study the Alumix 431/D commercial, press-ready grade powder was used for this purpose. Sintered compacts made of it in different conditions (isothermal sintering temperature, gas flow rate) were subjected to corrosion experiments in 0,1 M and 0,5 M NaCl solutions. The potentiodynamic curves were used to establish parameters characterising the corrosion resistance of sintered Alumix 431/D powder, namely, the corrosion potential, the corrosion current density, the polarization resistance, the breakdown potential. The highest value of polarization resistance, the lowest value of corrosion current density and the most positive corrosion potential was obtained for Alumix431/D powder sintered at 600°C and for highest protective gas flow rate.

Keywords: aluminium alloys, sintering, corrosion resistance, industry

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Authors: Marco Frieslaar, Bing Chu, Eric Rogers

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Stroke is a devastating illness that is the second biggest cause of death in the world (after heart disease). Where it does not kill, it leaves survivors with debilitating sensory and physical impairments that not only seriously harm their quality of life, but also cause a high incidence of severe depression. It is widely accepted that early intervention is essential for recovery, but current rehabilitation techniques largely favor hospital-based therapies which have restricted access, expensive and specialist equipment and tend to side-step the emotional challenges. In addition, there is insufficient funding available to provide the long-term assistance that is required. As a consequence, recovery rates are poor. The relatively unexplored solution is to develop therapies that can be harnessed in the home and are formulated from technologies that already exist in everyday life. This would empower individuals to take control of their own improvement and provide choice in terms of when and where they feel best able to undertake their own healing. This research seeks to identify how effective post-stroke, rehabilitation therapy can be applied to upper limb mobility, within the physical context of a home rather than a hospital. This is being achieved through the design and construction of an automation scheme, based on iterative learning control and the Riener muscle model, that has the ability to adapt to the user and react to their level of fatigue and provide tangible physical recovery. It utilizes a SMART Phone and laptop to construct an iterative learning control (ILC) system, that monitors upper arm movement in three dimensions, as a series of exercises are undertaken. The equipment generates functional electrical stimulation to assist in muscle activation and thus improve directional accuracy. In addition, it monitors speed, accuracy, areas of motion weakness and similar parameters to create a performance index that can be compared over time and extrapolated to establish an independent and objective assessment scheme, plus an approximate estimation of predicted final outcome. To further extend its assessment capabilities, nerve conduction velocity readings are taken by the software, between the shoulder and hand muscles. This is utilized to measure the speed of response of neuron signal transfer along the arm and over time, an online indication of regeneration levels can be obtained. This will prove whether or not sufficient training intensity is being achieved even before perceivable movement dexterity is observed. The device also provides the option to connect to other users, via the internet, so that the patient can avoid feelings of isolation and can undertake movement exercises together with others in a similar position. This should create benefits not only for the encouragement of rehabilitation participation, but also an emotional support network potential. It is intended that this approach will extend the availability of stroke recovery options, enable ease of access at a low cost, reduce susceptibility to depression and through these endeavors, enhance the overall recovery success rate.

Keywords: home-based therapy, iterative learning control, Riener muscle model, SMART phone, stroke rehabilitation

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Authors: Yuanyuan Fu

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Background and Purpose: Along with the change of society and economy, the traditional home function of old people has gradually weakened in the contemporary China. Acknowledging these situations, to better meet old people’s needs on formal services and improve the quality of later life, this study seeks to identify patterns of intended service use among frail old people living in the communities and examined determinants that explain heterogeneous variations in old people’s intended service use patterns. Additionally, this study also tested the relationship between culture value and intended service use patterns and the mediating role of enabling factors in terms of culture value and intended service use patterns. Methods：Participants were recruited from Haidian District, Beijing, China in 2015. The multi-stage sampling method was adopted to select sub-districts, communities and old people aged 70 years old or older. After screening, 577 old people with limitations in daily life, were successfully interviewed. After data cleaning, 550 samples were included for data analysis. This study establishes a conceptual framework based on the Anderson Model (including predisposing factors, enabling factors and need factors), and further developed it by adding culture value factors (including attitudes towards filial piety and attitudes towards social face). Using a latent class analysis (LCA), this study classifies overall patterns of old people’s formal service utilization. Fourteen types of formal services were taken into account, including housework, voluntary support, transportation, home-delivered meals, and home-delivery medical care, elderly’s canteen and day-care center/respite care and so on. Structural equation modeling (SEM) was used to examine the direct effect of culture value on service use pattern, and the mediating effect of the enabling factors. Results: The LCA classified a hierarchical structure of service use patterns: multiple intended service use (N=69, 23%), selective intended service use (N=129, 23%), and light intended service use (N=352, 64%). Through SEM, after controlling predisposing factors and need factors, the results showed the significant direct effect of culture value on older people’s intended service use patterns. Enabling factors had a partial mediation effect on the relationship between culture value and the patterns. Conclusions and Implications: Differentiation of formal services may be important for meeting frail old people’s service needs and distributing program resources by identifying target populations for intervention, which may make reference to specific interventions to better support frail old people. Additionally, culture value had a unique direct effect on the intended service use patterns of frail old people in China, enriching our theoretical understanding of sources of culture value and their impacts. The findings also highlighted the mediation effects of enabling factors on the relationship between culture value factors and intended service use patterns. This study suggests that researchers and service providers should pay more attention to the important role of culture value factors in contributing to intended service use patterns and also be more sensitive to the mediating effect of enabling factors when discussing the relationship between culture value and the patterns.

Keywords: frail old people, intended service use pattern, culture value, enabling factors, contemporary China, latent class analysis

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Authors: Carlos Alberto Ríos Reyes

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Traditionally, clays have been considered as one of the main problems in the flow of fluids in hydrocarbon reservoirs. However, there is not known the significance of zeolites formed from the reactivity of clays and their effect not only on the costs of operations carried out by the oil industry in the world but also on production. The present work focused on understanding the interaction between clay minerals with brines and alkaline solutions used in the oil industry. For this, a comparative study was conducted where the reaction of sedimentary rocks under laboratory conditions was examined. Original and treated rocks were examined by X-ray powder diffraction (XRPD) and Scanning Electron Microscopy (SEM) to determine the changes that these rocks underwent upon contact with fluids of variable chemical composition. As a result, zeolite Linde Type A (LTA), sodalite (SOD), and cancrinite (CAN) can be formed after experimental work, which coincided with the dissolution of kaolinite and smectite. Results reveal that the Oil Industry should invest efforts and focus its gaze to understand at the pore scale the problem that could arise as a consequence of the clay-fluid interaction in hydrocarbon reservoir rocks due to the presence of clays in their porous system, as well as the formation of zeolites, which are better hydrocarbon absorbents. These issues could be generating losses in world production. We conclude that there is a critical situation that may be occurring in the stimulation of hydrocarbon reservoirs, where real solutions are necessary not only for the formulation of more efficient and effective injection fluids but also to contribute to the improvement of production and avoid considerable losses in operating costs.

Keywords: clay minerals, zeolites, rock-fluid interaction, experimental work, reactivity

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Authors: Walid Cherif

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Data mining has, over recent years, seen big advances because of the spread of internet, which generates everyday a tremendous volume of data, and also the immense advances in technologies which facilitate the analysis of these data. In particular, classification techniques are a subdomain of Data Mining which determines in which group each data instance is related within a given dataset. It is used to classify data into different classes according to desired criteria. Generally, a classification technique is either statistical or machine learning. Each type of these techniques has its own limits. Nowadays, current data are becoming increasingly heterogeneous; consequently, current classification techniques are encountering many difficulties. This paper defines new measure functions to quantify the resemblance between instances and then combines them in a new approach which is different from actual algorithms by its reliability computations. Results of the proposed approach exceeded most common classification techniques with an f-measure exceeding 97% on the IRIS Dataset.

Keywords: data mining, knowledge discovery, machine learning, similarity measurement, supervised classification

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Authors: Aouissi Nora, Meksem Leila

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This work focused on the study of air pollution generated by the transport sector in the region of Annaba. Our study is based on two parts: the first one concerns an epidemiological investigation in the area of Annaba situated in the east Algerian coast, which deals with the development of the fleet and its impact on public health. To get a more precise idea of the impact of road traffic on public health, we consulted the computing center office of the National Social Insurance Fund. The information we were given by this office refers to the number of reported asthma and heart disease after medical examination during the period 2006-2010. The second part was devoted to the study of the toxicity of exhaust gases on some physical and biochemical parameters of durum wheat (Triticum durum Desf.). After germination and three-leaf stage, the pots are placed in a box of volume (0,096 m3) having an input which is linked directly to the exhaust pipe of a truck, and an outlet to prevent asphyxiation plant. The experience deals with 30 pots: 10 pots are exposed for 5 minutes to exhaust smoke; the other 10 are exposed for 15 minutes, and the remaining 10 for 30 minutes. The epidemiological study shows that the levels of pollutants emitted by the fleet are responsible for the increase of people respiratory and cardiovascular diseases. As for biochemical analyses of vegetation, they clearly show the toxicity of pollutants emitted by the exhaust gases, with an increase in total protein, proline and stimulation of detoxification enzyme (catalase).

Keywords: air pollution, toxicity, epidemiology, biochemistry

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Authors: Abubakar Uba Ibrahim, Ibrahim Haruna Shanono

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Smart metering and demand response are gaining ground in industrial and residential applications. Smart Appliances have been given concern towards achieving Smart home. The success of Smart grid development relies on the successful implementation of Information and Communication Technology (ICT) in power sector. Smart Appliances have been the technology under development and many new contributions to its realization have been reported in the last few years. The role of ICT here is to capture data in real time, thereby allowing bi-directional flow of information/data between producing and utilization point; that lead a way for the attainment of Smart appliances where home appliances can communicate between themselves and provide a self-control (switch on and off) using the signal (information) obtained from the grid. This paper depicts the background on ICT for smart appliances paying a particular attention to the current technology and identifying the future ICT trends for load monitoring through which smart appliances can be achieved to facilitate an efficient smart home system which promote demand response program. This paper grouped and reviewed the recent contributions, in order to establish the current state of the art and trends of the technology, so that the reader can be provided with a comprehensive and insightful review of where ICT for smart appliances stands and is heading to. The paper also presents a brief overview of communication types, and then narrowed the discussion to the load monitoring (Non-intrusive Appliances Load Monitoring ‘NALM’). Finally, some future trends and challenges in the further development of the ICT framework are discussed to motivate future contributions that address open problems and explore new possibilities.

Keywords: communication technology between appliances, demand response, load monitoring, smart appliances, smart grid

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Authors: Ahn Christine Myunghee, Sim Wonjin, Cho Kristina, Ahn Mira, Hong Yeju, Kwok Jihae, Lim Sooyeon, Park Hansol

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With a sharp increase in the prevalence rate for mental health issues in Korea, there is a need for specific and effective intervention strategies in counseling and psychotherapy for use with Korean clients. With the cultural emphasis on restraining emotional expression and not disclosing personal and familial problems to outsiders, clients often find it difficult to discuss their emotional issues even to therapists. Exploring a client’s internal psychological processes bypassing this culture-specific mode of therapeutic communication often becomes a challenge in the therapeutic setting. Given this socio-cultural context, the purpose of the current study was to investigate the effectiveness of using dream work to individuals in Korea. The current study conducted one 60-90 minute dream session and analyzed the dream content of 39 Korean young adults to evaluate the effectiveness of the Hill dream model in accessing the intra-psychic materials, determining essential emotional themes, and learning how the individuals interpreted the contents of their dreams. The transcribed data, which included a total of 39 sessions from 39 volunteer university students, were analyzed by the Consensus Qualitative Research (CQR) approach in terms of domains and core ideas. Self-report measures on Dream Salience, Gains from Dream Interpretations and the Session Evaluation Scale were administered before and after each of their dream sessions. The results indicated that dream work appears to be an effective way to understand unconscious motivations, thoughts, and feelings related to a person’s sense of self, and also how these people relate to other people. Current findings need to be replicated with clients referred for counseling and psychotherapy to determine if the dream work is an appropriate and useful intervention in counseling settings. Limitations of the current study and suggestions for future follow-ups are included in the discussion.

Keywords: dream work, dream interpretation, Korean, young adults, CQR

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Authors: Xiao Yu Yang

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In the current era of AI and the Internet, students' access to AI has increased significantly, and it is no longer surprising that young generations can effectively utilize resources to learn foreign languages. This study aims to investigate the foreign language classroom anxiety of college students who just entered university in 2024 and understand the current anxiety levels of students. Meanwhile, this study conducts the investigation by using a scale tool based on the FLCAS (Foreign Language Classroom Anxiety Scale), which consists of 21 items that were adjusted and re-tested for validity in 2019. A total of three classes taught by the researcher participated in this study. Further interview comparisons are conducted, particularly with students from rural areas and urban cities. Considering the prevalence of AI in modern education, the relationship between the investigated foreign language classroom anxiety and the adopted AI-assisted teaching and learning will be further explored to discuss potential implications.

Keywords: FLCAS in China, freshman, AI, English teaching

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Authors: Reham Niazi, Marwa Helmy, Susanne Rizzo

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This classroom action research is designed to explore the possibility of adding effective online content to supplement and add learning value to the current reading module. The aim of this research was two-fold, first to investigate students’ acceptance of and interactivity with online components, chosen to orient students with the content, and to pave the way for more in-class activities and skill practice. Secondly, the instructor aimed to examine students’ willingness to have the course contact hours remain the same with some online components to be done at home (flipped approach) or if students were open to turn the class into a blended format with two scenarios; either to have the current contact hours and apply the blended and in this case the face to face component will be less or keep the number of face to face classes the same and add more online structured classes as part of the course hours.

Keywords: blended learning, flipped classroom, graduate students, education

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Authors: Alexander N. Pisarchik, Parth Chholak

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Intrinsic brain noise was estimated via magneto-encephalograms (MEG) recorded during perception of flickering visual stimuli with frequencies of 6.67 and 8.57 Hz. First, we measured the mean phase difference between the flicker signal and steady-state event-related field (SSERF) in the occipital area where the brain response at the flicker frequencies and their harmonics appeared in the power spectrum. Then, we calculated the probability distribution of the phase fluctuations in the regions of frequency locking and computed its kurtosis. Since kurtosis is a measure of the distribution’s sharpness, we suppose that inverse kurtosis is related to intrinsic brain noise. In our experiments, the kurtosis value varied among subjects from K = 3 to K = 5 for 6.67 Hz and from 2.6 to 4 for 8.57 Hz. The majority of subjects demonstrated leptokurtic kurtosis (K < 3), i.e., the distribution tails approached zero more slowly than Gaussian. In addition, we found a strong correlation between kurtosis and brain complexity measured as the correlation dimension, so that the MEGs of subjects with higher kurtosis exhibited lower complexity. The obtained results are discussed in the framework of nonlinear dynamics and complex network theories. Specifically, in a network of coupled oscillators, phase synchronization is mainly determined by two antagonistic factors, noise, and the coupling strength. While noise worsens phase synchronization, the coupling improves it. If we assume that each neuron and each synapse contribute to brain noise, the larger neuronal network should have stronger noise, and therefore phase synchronization should be worse, that results in smaller kurtosis. The described method for brain noise estimation can be useful for diagnostics of some brain pathologies associated with abnormal brain noise.

Keywords: brain, flickering, magnetoencephalography, MEG, visual perception, perception time

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Authors: J. Martin, A. Nominé, T. Czerwiec, G. Henrion, T. Belmonte

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The plasma electrolytic oxidation (PEO) is a particular electrochemical process to produce protective oxide ceramic coatings on light-weight metals (Al, Mg, Ti). When applied to aluminum alloys, the resulting PEO coating exhibit improved wear and corrosion resistance because thick, hard, compact and adherent crystalline alumina layers can be achieved. Several investigations have been carried out to improve the efficiency of the PEO process and one particular way consists in tuning the suitable electrical regime. Despite the considerable interest in this process, there is still no clear understanding of the underlying discharge mechanisms that make possible metal oxidation up to hundreds of µm through the ceramic layer. A key parameter that governs the PEO process is the numerous short-lived micro-discharges (micro-plasma in liquid) that occur continuously over the processed surface when the high applied voltage exceeds the critical dielectric breakdown value of the growing ceramic layer. By using a bipolar pulsed current to supply the electrodes, we previously observed that micro-discharges are delayed with respect to the rising edge of the anodic current. Nevertheless, explanation of the origin of such phenomena is still not clear and needs more systematic investigations. The aim of the present communication is to identify the relationship that exists between this delay and the mechanisms responsible of the oxide growth. For this purpose, the delay of micro-discharges ignition is investigated as the function of various electrical parameters such as the current density (J), the current pulse frequency (F) and the anodic to cathodic charge quantity ratio (R = Qp/Qn) delivered to the electrodes. The PEO process was conducted on Al2214 aluminum alloy substrates in a solution containing potassium hydroxide [KOH] and sodium silicate diluted in deionized water. The light emitted from micro-discharges was detected by a photomultiplier and the micro-discharge parameters (number, size, life-time) were measured during the process by means of ultra-fast video imaging (125 kfr./s). SEM observations and roughness measurements were performed to characterize the morphology of the elaborated oxide coatings while XRD was carried out to evaluate the amount of corundum -Al203 phase. Results show that whatever the applied current waveform, the delay of micro-discharge appearance increases as the process goes on. Moreover, the delay is shorter when the current density J (A/dm2), the current pulse frequency F (Hz) and the ratio of charge quantity R are high. It also appears that shorter delays are associated to stronger micro-discharges (localized, long and large micro-discharges) which have a detrimental effect on the elaborated oxide layers (thin and porous). On the basis of the results, a model for the growth of the PEO oxide layers will be presented and discussed. Experimental results support that a mechanism of electrical charge accumulation at the oxide surface / electrolyte interface takes place until the dielectric breakdown occurs and thus until micro-discharges appear.

Keywords: aluminium, micro-discharges, oxidation mechanisms, plasma electrolytic oxidation

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Authors: Gaurav Prabhudesai, Shaurya Kaushal, Pulkit Dubey, B. D. Pant

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The current race of miniaturization of circuits, systems, modules and networks has resulted in portable and mobile wireless systems having tremendous capabilities with small volume and weight. The power drivers or the power pack, electrically driving these modules have also reduced in proportion. Normally, the power packs in these mobile or fixed systems are batteries, rechargeable or non-rechargeable, which need regular replacement or recharging. Another approach to power these modules is to utilize the ambient energy available for electrical driving to make the system self-sustained. The current paper presents an overview of the different MEMS (Micro-Electro-Mechanical Systems) based techniques used for the harvesting of vibration energy to electrically drive a WSN (wireless sensor network) or a mobile module. This kind of system would have enormous applications, the most significant one, may be in cell phones.

Keywords: energy harvesting, WSN, MEMS, piezoelectrics

Procedia PDF Downloads 502