Search results for: short fiber composites

Authors: Majeda S. Hammoud

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Background and Aim: Gestational diabetes mellitus (GDM) is a common pregnancy complication affecting around 14% of pregnancies globally that carries short and long-term consequences to the mother and her child. Pre-pregnancy overweight or obesity is the most consistently and strongly associated modifiable risk factor with GDM development. This analysis aimed to determine whether vitamin D status during pregnancy modulates the effect of pre-pregnancy obesity/overweight on GDM risk while stratifying by maternal age. Methods: Data from the Kuwait Birth Cohort (KBC) study were analyzed, which enrolled pregnant women in the second or third trimester of gestation. Pre-pregnancy body mass index (BMI; kg/m2) was categorized as under/normal weight (<25.0), overweight (25.0 to <30.0), and obesity (≥30.0). 25 hydroxyvitamin D levels were measured in blood samples that were collected at recruitment and categorized as deficiency (<50 nmol/L) and insufficiency/sufficiency (≥50 nmol/L). GDM status was ascertained according to international guidelines. Logistic regression was used to evaluate associations, and adjusted odds ratios (aOR) and 95% confidence intervals (CI) were estimated. Results: The analyzed study sample included a total of 982 pregnant women, with a mean (SD) age of 31.4 (5.2) years. The prevalence of GDM was estimated to be 17.3% (95% CI: 14.9-19.7), and the prevalence of pre-pregnancy overweight and obesity was 37.8% (95% CI: 34.8-40.8) and 28.8% (95% CI: 26.0-31.7), respectively. The prevalence of gestational vitamin D deficiency was estimated to be 55.3% (95% CI: 52.2-58.4). The association between pre-pregnancy overweight or obesity with GDM risk differed according to maternal age and gestational vitamin D status (Pinteraction[BMI × age × vitamin D = 0.047). Among pregnant women aged <35 years, prepregnancy obesity compared to under/normal weight was associated with increased GDM risk among women with gestational vitamin D deficiency (aOR: 3.65, 95% CI: 1.50-8.86, p = 0.004) and vitamin D insufficiency/sufficiency (aOR: 2.55, 95% CI: 1.16-5.61, p = 0.019). In contrast, among pregnant women aged ≥35 years, pre-pregnancy obesity compared to under/normal weight was associated with increased GDM risk among women with gestational vitamin D deficiency (aOR: 9.70, 95% CI: 2.01-46.69, p = 0.005), but not among women with vitamin D insufficiency/sufficiency (aOR: 1.46, 95% CI: 0.42-5.16, p = 0.553). Conclusion: The effect of pre-pregnancy obesity on GDM risk is modulated by maternal age and gestational vitamin D status, with the effect of pre-pregnancy obesity being more pronounced among older pregnant women (aged ≥35 years) with gestational vitamin D deficiency compared to those with vitamin D insufficiency/sufficiency. Whereas, among younger women (aged <35 years), the effect of pre-pregnancy obesity on GDM risk was not modulated by gestational vitamin D status. Therefore, vitamin D supplementation among pregnant women, specifically older women with pre-pregnancy obesity, may mitigate the effect of pre-pregnancy obesity on GDM risk.

Keywords: gestational diabetes mellitus, vitamin D, obesity, body mass index

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Authors: Ji Young Lee, Jong Woon Kim

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It is essential to secure high availability of railway vehicles to realize high quality and efficiency of railway service. Once the availability decreased, planned railway service could not be provided or more cars need to be reserved. additional cars need to be purchased or the frequency of railway service could be decreased. Such situation would be a big loss in terms of quality and cost related to railway service. Therefore, we make various efforts to get high availability of railway vehicles. Because it is a big loss to operators, we make various efforts to get high availability of railway vehicles. To secure high availability, the idle time of the vehicle needs to be reduced and the following methods are applied to railway vehicles. First, through modularization design, exchange time for line replaceable units is reduced which makes railway vehicles could be put into the service quickly. Second, to reduce periodic preventive maintenance time, preventive maintenance with short period would be proceeded test oriented to minimize the maintenance time, and reliability is secured through overhauls for each main component. With such design changes for railway vehicles, modularized components are exchanged first at the time of vehicle failure or overhaul so that vehicles could be put into the service quickly and exchanged components are repaired or overhauled. Therefore, spare components are required for any future failures or overhauls. And, as components are modularized and costs for components are high, it is considerably important to get reasonable quantities of spare components. Especially, when a number of railway vehicles were put into the service simultaneously, the time of overhauls come almost at the same time. Thus, for some vehicles, components need to be exchanged and overhauled before appointed overhaul period so that these components could be secured as spare parts for the next vehicle’s component overhaul. For this reason, components overhaul time and spare parts quantities should be decided at the same time. This study deals with the time of overhauls for repairable components of railway vehicles and the calculation of spare parts quantities in consideration of future failure/overhauls. However, as railway vehicles are used according to the service schedule, maintenance work cannot be proceeded after the service was closed thus it is quite difficult to resolve this situation mathematically. In this study, Simulation software system is used in this study for analyzing the time of overhauls for repairable components of railway vehicles and the spare parts for the railway systems.

Keywords: overhaul time, rolling stocks, simulation, spare parts

Procedia PDF Downloads 337

Authors: Vinay Singh, Chandra Deo, Asit Chakrabarti, Lopamudra Sahoo, Mahak Singh, Rakesh Kumar, Dinesh Kumar, H. Bharati, Biswajit Das, V. K. Mishra

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The most widely used feed resources in poultry feed, like maize and soybean, are expensive as well as in short supply. Hence, there is a need to utilize non-conventional feed ingredients to cut down feed costs. As an alternative, brewery by-products like brewers’ dried grains are potential non-conventional feed resources. North-East India is inhabited by many tribes, and most of these tribes prepare their indigenous local brew, mostly using rice grains as the primary substrate. Choak, a homemade rice beer waste, is an excellent and cheap source of protein and other nutrients. Fresh homemade rice beer waste (rice brewer’s grain) was collected locally. The proximate analysis indicated 28.53% crude protein, 92.76% dry matter, 5.02% ether extract, 7.83% crude fibre, 2.85% total ash, 0.67% acid insoluble ash, 0.91% calcium, and 0.55% total phosphorus. A feeding trial with 5 treatments (incorporating rice beer waste at the inclusion levels of 0,10,20,30 & 40% by replacing maize and soybean from basal diet) was conducted with 25 laying hens per treatment for 16 weeks under completely randomized design in order to study the production performance, blood-biochemical parameters, immunity, egg quality and cost economics of laying hens. The results showed substantial variations (P<0.01) in egg production, egg mass, FCR per dozen eggs, FCR per kg egg mass, and net FCR. However, there was not a substantial difference in either body weight or feed intake or in egg weight. Total serum cholesterol reduced significantly (P<0.01) at 40% inclusion of rice beer waste. Additionally, the egg haugh unit grew considerably (P<0.01) when the graded levels of rice beer waste increased. The inclusion of 20% rice brewers dried grain reduced feed cost per kg egg mass and per dozen egg production by Rs. 15.97 and 9.99, respectively. Choak (homemade rice beer waste) can thus be safely incorporated into the diet of laying hens at a 20% inclusion level for better production performance and cost-effectiveness.

Keywords: choak, rice beer waste, laying hen, production performance, cost economics

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Authors: Kirsten Techmer, Jan-Erik Rybak, Simon Rudolph

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Natural formed pyrites (FeS2) are frequent sulfides in sedimentary and metamorphic rocks. Growth textures of idiomorphic pyrite assemblages reflect the conditions during their formation in the geologic sequence, furtheron the local texture analyses of the growth patterns of pyrite assemblages by EBSD reveal the possibility to resolve the growth conditions during the formation of pyrite at the micron scale. The spatial resolution of local texture measurements in the Scanning Electron Microscope used can be in the nanomete scale. Orientation contrasts resulting from domains of smaller misorientations within larger pyrite crystals can be resolved as well. The electron optical studies have been carried out in a Field-Emission Scanning Electron Microscope (FEI Quanta 200) equipped with a CCD camera to study the orientation contrasts along the surfaces of pyrite. Idiomorphic cubic single crystals of pyrite, polycrystalline assemblages of pyrite, spherically grown spheres of pyrite as well as pyrite-bearing ammonites have been studied by EBSD in the Scanning Electron Microscope. Samples were chosen to show no or minor secondary deformation and an idiomorphic 3D crystal habit, so the local textures of pyrite result mainly from growth and minor from deformation. The samples studied derived from Navajun (Spain), Chalchidiki (Greece), Thüringen (Germany) and Unterkliem (Austria). Chemical analyses by EDAX show pyrite with minor inhomogeneities e.g., single crystals of galena and chalcopyrite along the grain boundaries of larger pyrite crystals. Intergrowth between marcasite and pyrite can be detected in one sample. Pyrite may form intense growth twinning lamellae on {011}. Twinning, e.g., contact twinning is abundant within the crystals studied and the individual twinning lamellaes can be resolved by EBSD. The ammonites studied show a replacement of the shale by newly formed pyrite resulting in an intense intergrowth of calcite and pyrite. EBSD measurements indicate a polycrystalline microfabric of both minerals, still reflecting primary surface structures of the ammonites e.g, the Septen. Discs of pyrite (“pyrite dollar”) as well as pyrite framboids show growth patterns comprising a typical microfabric. EBSD studies reveal an equigranular matrix in the inner part of the discs of pyrite and a fiber growth with larger misorientations in the outer regions between the individual segments. This typical microfabric derived from a formation of pyrite crystals starting at a higher nucleation rate and followed by directional crystal growth. EBSD studies show, that the growth texture of pyrite in the samples studied reveals a correlation between nucleation rate and following growth rate of the pyrites, thus leading to the characteristic crystal habits. Preferential directional growth at lower nucleation rates may lead to the formation of 3D framboids of pyrite. Crystallographic misorientations between the individual fibers are similar. In ammonites studied, primary anisotropies of the substrates like e.g., ammonitic sutures, influence the nucleation, crystal growth and habit of the newly formed pyrites along the surfaces.

Keywords: Electron Back Scatter Diffraction (EBSD), growth pattern, Fe-sulfides (pyrite), texture analyses

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Authors: Jonathan Ogwal, Louis H. Kamulegeya, John M. Bwanika, Davis Musinguzi

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Introduction: Community retail Pharmacy drug distribution points (CRPDDP) were implemented in the Lango sub-region as part of the Ministry of Health’s response to improving access and adherence to antiretroviral treatment (ART). Clients received their ART refills from nearby local pharmacies; as such, the need for continuous engagement through mobile phone appointment reminders and health messages. We share learnings from the implementation of mobile text reminders and voice call follow-ups among ART clients attending the CRPDDP program in northern Uganda. Methods: A retrospective data review of electronic medical records from four pharmacies allocated for CRPDDP in the Lira and Apac districts of the Lango sub-region in Northern Uganda was done from February to August 2022. The process involved collecting phone contacts of eligible clients from the health facility appointment register and uploading them onto a messaging platform customized by Rapid-pro, an open-source software. Client information, including code name, phone number, next appointment date, and the allocated pharmacy for ART refill, was collected and kept confidential. Contacts received appointment reminder messages and other messages on positive living as an ART client. Routine voice call follow-ups were done to ascertain the picking of ART from the refill pharmacy. Findings: In total, 1,354 clients were reached from the four allocated pharmacies found in urban centers. 972 clients received short message service (SMS) appointment reminders, and 382 were followed up through voice calls. The majority (75%) of the clients returned for refills on the appointed date, 20% returned within four days after the appointment date, and the remaining 5% needed follow-up where they reported that they were not in the district by the appointment date due to other engagements. Conclusion: The use of mobile text reminders and voice call follow-ups improves the attendance of community retail pharmacy refills.

Keywords: antiretroviral treatment, community retail drug distribution points, mobile text reminders, voice call follow-up

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Authors: Emilienne Lardy, Eric Ballot, Mariam Lafkihi

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Efficient urban logistics requires a comprehensive understanding of traffic dynamics, particularly as it pertains to kinetic parameters influencing energy consumption and trip duration estimations. While real-time traffic information is increasingly accessible, current high-precision forecasting services embedded in route planning often function as opaque 'black boxes' for users. These services, typically relying on AI-processed counting data, fall short in accommodating open design parameters essential for management studies, notably within Supply Chain Management. This work revisits the modelling of traffic conditions in the context of city logistics, emphasizing its significance from the user’s point of view, with two focuses. Firstly, the focus is not on the vehicle flow but on the vehicles themselves and the impact of the traffic conditions on their driving behaviour. This means opening the range of studied indicators beyond vehicle speed, to describe extensively the kinetic and dynamic aspects of the driving behaviour. To achieve this, we leverage the Art. Kinema parameters are designed to characterize driving cycles. Secondly, this study examines how the driving context (i.e., exogenous factors to the traffic flow) determines the mentioned driving behaviour. Specifically, we explore how accurately the kinetic behaviour of a vehicle can be predicted based on a limited set of exogenous factors, such as time, day, road type, orientation, slope, and weather conditions. To answer this question, statistical analysis was conducted on real-world driving data, which includes high-frequency measurements of vehicle speed. A Factor Analysis and a Generalized Linear Model have been established to link kinetic parameters with independent categorical contextual variables. The results include an assessment of the adjustment quality and the robustness of the models, as well as an overview of the model’s outputs.

Keywords: factor analysis, generalised linear model, real world driving data, traffic congestion, urban logistics, vehicle kinematics

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Authors: Jin Liang, James H. Liu, Ti-Jun Xiao

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It is known that there exist many physical phenomena where abrupt or impulsive changes occur either in the system dynamics, for example, ad-hoc network, or in the input forces containing impacts, for example, the bombardment of space antenna by micrometeorites. There are many other examples such as ultra high-speed optical signals over communication networks, the collision of particles, inventory control, government decisions, interest changes, changes in stock price, etc. These are impulsive phenomena. Hence, as a combination of the traditional initial value problems and the short-term perturbations whose duration can be negligible in comparison with the duration of the process, the systems with impulsive conditions (i.e., impulsive systems) are more realistic models for describing the impulsive phenomenon. Such a situation is also suitable for the delay systems, which include some of the past states of the system. So far, there have been a lot of research results in the study of impulsive systems with delay both in finite and infinite dimensional spaces. In this paper, we investigate the periodicity of solutions to the nonautonomous impulsive evolution equations with infinite delay in Banach spaces, where the coefficient operators (possibly unbounded) in the linear part depend on the time, which are impulsive systems in infinite dimensional spaces and come from the optimal control theory. It was indicated that the study of periodic solutions for these impulsive evolution equations with infinite delay was challenging because the fixed point theorems requiring some compactness conditions are not applicable to them due to the impulsive condition and the infinite delay. We are happy to report that after detailed analysis, we are able to combine the techniques developed in our previous papers, and some new ideas in this paper, to attack these impulsive evolution equations and derive periodic solutions. More specifically, by virtue of the related transition operator family (evolution family), we present a Poincaré operator given by the nonautonomous impulsive evolution system with infinite delay, and then show that the operator is a condensing operator with respect to Kuratowski's measure of non-compactness in a phase space by using an Amann's lemma. Finally, we derive periodic solutions from bounded solutions in view of the Sadovskii fixed point theorem. We also present a relationship between the boundedness and the periodicity of the solutions of the nonautonomous impulsive evolution system. The new results obtained here extend some earlier results in this area for evolution equations without impulsive conditions or without infinite delay.

Keywords: impulsive, nonautonomous evolution equation, optimal control, periodic solution

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Authors: Mohammed S. Razali, Kamel Khimeche, Dahah Hichem, Ammar Boudjellal, Djamel E. Kaderi, Nourddine Ramdani

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The use of additive manufacturing technologies has revolutionized various aspects of our daily lives. In particular, 3D printing has greatly advanced biomedical applications. While fused filament fabrication (FFF) technologies have made it easy to produce or prototype various medical devices, it is crucial to minimize the risk of contamination. New materials with antibacterial properties, such as those containing compounded silver nanoparticles, have emerged on the market. In a previous study, we prepared a newly sintered seashell filler (SSh) from bio-based seashells found along the Mediterranean coast using a suitable heat treatment process. We then prepared a series of polylactic acid (PLA) and polybutylene succinate (PBS) biocomposites filled with these SSh particles using a melt mixing technique with a twin-screw extruder to use them as feedstock filaments for 3D printing. The study consisted of two parts: evaluating the antibacterial activity of newly prepared biocomposites made of PLA and PBS reinforced with a sintered seashell in the first part and experimental and modeling analysis of the non-isothermal crystallization kinetics of these biocomposites in the second part. In the first part, the bactericidal activity of the biocomposites against three different bacteria, including Gram-negative bacteria such as (E. coli and Pseudomonas aeruginosa), as well as Gram-positive bacteria such as (Staphylococcus aureus), was examined. The PLA-based biocomposite containing 20 wt.% of SSh particles exhibited an inhibition zone with radial diameters of 8mm and 6mm against E. coli and Pseudo. Au, respectively, while no bacterial activity was observed against Staphylococcus aureus. In the second part, the focus was on investigating the effect of the sintered seashell filler particles on the non-isothermal crystallization kinetics of PLA and PBS 3D-printing composite materials. The objective was to understand the impact of the filler particles on the crystallization mechanism of both PLA and PBS during the cooling process of a melt-extruded filament in (FFF) to manage the dimensional accuracy and mechanical properties of the final printed part. We conducted a non-isothermal melt crystallization kinetic study of a series of PLA-SS and PBS-SS composites using differential scanning calorimetry at various cooling rates. We analyzed the obtained kinetic data using different crystallization kinetic models such as modified Avrami, Ozawa, and Mo's methods. Dynamic mode describes the relative crystallinity as a function of temperature; it found that time half crystallinity (t1/2) of neat PLA decreased from 17 min to 7.3 min for PLA+5 SSh and the (t1/2) of virgin PBS was reduced from 3.5 min to 2.8 min for the composite containing 5wt.% of SSh. We found that the coated SS particles with stearic acid acted as nucleating agents and had a nucleation activity, as observed through polarized optical microscopy. Moreover, we evaluated the effective energy barrier of the non-isothermal crystallization process using the Iso conversional methods of Flynn-Wall-Ozawa (F-W-O) and Kissinger-Akahira-Sunose (K-A-S). The study provides significant insights into the crystallization behavior of PLA and PBS biocomposites.

Keywords: avrami model, bio-based reinforcement, dsc, gram-negative bacteria, gram-positive bacteria, isoconversional methods, non-isothermal crystallization kinetics, poly(butylene succinate), poly(lactic acid), antbactirial activity

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Authors: Arega Shumetie Ademe, Belay Kassa, Degye Goshu, Majaliwa Mwanjalolo

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Currently the world economy is suffering from one critical problem, climate change. Some studies done before identified that impact of the problem is region specific means in some part of the world (temperate zone) there is improvement in agricultural performance but in some others like in the tropics there is drastic reduction in crop production and crop income. Climate variability is becoming dominant cause of short-term fluctuation in rain-fed agricultural production and income of developing countries. The purely rain-fed Ethiopian agriculture is the most vulnerable sector to the risks and impacts of climate variability. Thus, this study tried to identify impact of climate variability on crop income of smallholders in Ethiopia. The research used eight rounded unbalanced panel data from 1994- 2014 collected from six villages in the study area. After having all diagnostic tests the research used fixed effect method of regression. Based on the regression result rainfall and temperature deviation from their respective long term averages have negative and significant effect on crop income. Other extreme devastating shocks like flood, storm and frost, which are sourced from climate variability, have significant and negative effect on crop income of households’. Parameters that notify rainfall inconsistency like late start, variation in availability at growing season, and early cessation are critical problems for crop income of smallholder households as to the model result. Given this, impact of climate variability is not consistent in different agro-ecologies of the country. Rainfall variability has similar impact on crop income in different agro-ecology, but variation in temperature affects cold agro-ecology villages negatively and significantly, while it has positive effect in warm villages. Parameters that represent rainfall inconsistency have similar impact in both agro-ecologies and the aggregate model regression. This implies climate variability sourced from rainfall inconsistency is the main problem of Ethiopian agriculture especially the crop production sub-sector of smallholder households.

Keywords: climate variability, crop income, household, rainfall, temperature

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Authors: Linda Dusman, Linda Baker

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The Bearman Study of Audience Engagement examined the potential for real-time music education during online symphony orchestra concerts. It follows on the promising results of a preliminary study of STEAM (Science, Technology, Engineering, Arts, and Mathematics) education during live concerts, funded by the National Science Foundation with the Baltimore Symphony Orchestra. For the Bearman Study, audience groups were recruited to attend two previously recorded concerts of the National Orchestral Institute (NOI) in 2020 or the Utah Symphony in 2021. They used a smartphone app called EnCue to present real-time program notes about the music being performed. Short notes along with visual information (photos and score fragments) were designed to provide historical, cultural, biographical, and theoretical information at specific moments in the music where that information would be most pertinent, generally spaced 2-3 minutes apart to avoid distraction. The music performed included Dvorak Symphony No. 8 and Mahler Symphony No. 5 at NOI, and Mendelssohn Scottish Symphony and Richard Strauss Metamorphosen with the Utah Symphony, all standard repertoire for symphony orchestras. During each phase of the study (2020 and 2021), participants were randomly assigned to use the app to view program notes during the first concert or to use the app during the second concert. A total of 139 participants (67 in 2020 and 72 in 2021) completed three online questionnaires, one before attending the first concert, one immediately after the concert, and the third immediately after the second concert. Questionnaires assessed demographic background, expertise in music, engagement during the concert, learning of content about the composers and the symphonies, and interest in the future use of the app. In both phases of the study, participants demonstrated that they learned content presented on the app, evidenced by the fact that their multiple-choice test scores were significantly higher when they used the app than when they did not. In addition, most participants indicated that using the app enriched their experience of the concert. Overall, they were very positive about their experience using the app for real-time learning and they expressed interest in using it in the future at both live and streaming concerts. Results confirmed that informal real-time learning during concerts is possible and can generate enhanced engagement and interest in classical music.

Keywords: audience engagement, informal education, music technology, real-time learning

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Authors: Shashi Sharma, V. K. Katiyar, Uaday Singh

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The ability to manipulate magnetic particles in fluid flows by means of inhomogeneous magnetic fields is used in a wide range of biomedical applications including magnetic drug targeting (MDT). In MDT, magnetic carrier particles bounded with drug molecules are injected into the vascular system up-stream from the malignant tissue and attracted or retained at the specific region in the body with the help of an external magnetic field. Although the concept of MDT has been around for many years, however, wide spread acceptance of the technique is still looming despite the fact that it has shown some promise in both in vivo and clinical studies. This is because traditional MDT has some inherent limitations. Typically, the magnetic force is not very strong and it is also very short ranged. Since the magnetic force must overcome rather large hydrodynamic forces in the body, MDT applications have been limited to sites located close to the surface of the skin. Even in this most favorable situation, studies have shown that it is difficult to collect appreciable amounts of the MDCPs at the target site. To overcome these limitations of the traditional MDT approach, Ritter and co-workers reported the implant assisted magnetic drug targeting (IA-MDT). In IA-MDT, the magnetic implants are placed strategically at the target site to greatly and locally increase the magnetic force on MDCPs and help to attract and retain the MDCPs at the targeted region. In the present work, we develop a mathematical model to study the capturing of magnetic nanoparticles flowing in a fluid in an implant assisted cylindrical channel under the magnetic field. A coil of ferromagnetic SS 430 has been implanted inside the cylindrical channel to enhance the capturing of magnetic nanoparticles under the magnetic field. The dominant magnetic and drag forces, which significantly affect the capturing of nanoparticles, are incorporated in the model. It is observed through model results that capture efficiency increases from 23 to 51 % as we increase the magnetic field from 0.1 to 0.5 T, respectively. The increase in capture efficiency by increase in magnetic field is because as the magnetic field increases, the magnetization force, which is attractive in nature and responsible to attract or capture the magnetic particles, increases and results the capturing of large number of magnetic particles due to high strength of attractive magnetic force.

Keywords: capture efficiency, implant assisted-magnetic drug targeting (IA-MDT), magnetic nanoparticles, modelling

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Authors: Qianli Ma, Xuemin Zhao, Lingai Yao, Zhencheng Xu, Li Wang

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Heavy metal pollution accidents, frequently happened in this decade in China, severely threaten aquatic ecosystem and economy. In January 2012, a basin-scale accidental Cd pollution happened in Longjiang River in southwest China. Although water quality was recovered in short period by emergency treatment with flocculants, a large amount of contaminated cage-cultivated fish were left with the task of preventing or mitigating Cd contamination of fish. In this study, unpolluted Ctenopharyngodon idellus were fed by Cd-contaminated macrophytes for assessing the effect of Cd accumulation through food exposure, and the contaminated C. idellus were fed with Cd-free macrophytes for assessing the ability of Cd depuration. The on-site cultivation experiments were done in two sites of Lalang (S1, accidental Cd pollution originated) and Sancha (S2, a large amount of flocculants were added to accelerate Cd precipitation) in Longjiang river. Results showed that Cd content in fish muscle presented an increasing trend in the accumulation experiment. In S1, Cd content of fish muscle rose sharply from day 8 to day 18 with higher average Cd content in macrophytes and sediment, and kept in the range of 0.208-0.308 mg/kg afterward. In S2, Cd content of fish muscle rose gradually throughout the experiment and reached the maximum level of 0.285 mg/kg on day 76. The results of the depuration experiment showed that Cd content in fish muscle decreased and significant changes were observed in the first half time of the experiment. Meanwhile, fish with lower initial Cd content presented higher elimination constant. In S1, Cd content of fish significantly decreased from 0.713 to 0.304 mg/kg in 18 days and kept decreasing to 0.110 mg/kg in the end, and 84.6% of Cd content was eliminated. While in S2, there was a sharp decrease of Cd content of fish in 0-8 days from 0.355 mg/kg to 0.069 mg/kg. The total elimination percentage was 93.8% and 80.6% of which appeared in day 0-8. The elimination constant of fish in S2 was 0.03 which was higher than 0.02 in S1. Collectively, our results showed Cd could be absorbed through food exposure and accumulate in fish muscle, and the accumulated Cd in fish muscle can be excreted after isolated from the polluted food sources. This knowledge allows managers to assess health risk of Cd contaminated fish and minimize aquaculture loss when considering fish cultivation after accidental pollution.

Keywords: accidental pollution, cadmium accumulation and depuration, cage-cultivated fish, environmental management, river

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Authors: Mona Solvoll, Ragnhild Kr. Olsen

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Background and significance of the study: Newspapers are going through radical changes with increased competition, eroding readerships and declining advertising resulting in plummeting overall revenues. This has lead to a quest for new business models, focusing on monetizing content. This research paper investigates both how local online newspapers have introduced user payment and how the audience has received these changes. Given the role of local media in keeping their communities informed and those in power accountable, their potential impact on civic engagement and cultural integration in local communities, the business model innovations of local media deserves far more research interest. Empirically, the findings are interesting for local journalists, local media managers as well as local advertisers. Basic methodologies: The study is based on interviews with commercial leaders in 20 Norwegian local newspapers in addition to a national survey data from 1600 respondents among local media users. The interviews were conducted in the second half of 2015, while the survey was conducted in September 2016. Theoretically, the study draws on the business model framework. Findings: The analysis indicates that paywalls aim more at reducing digital cannibalisation of print revenue than about creating new digital income. The newspapers are mostly concerned with retaining “old” print subscribers and transform them into digital subscribers. However, this strategy may come at a high price for newspapers if their defensive print strategy drives away younger digital readership and hamper their recruitment potential for new audiences as some previous studies have indicated. Analysis of young reader news habits indicates that attracting the younger audience to traditional local news providers is particularly challenging and that they are more prone to seek alternative news sources than the older audience is. Conclusion: The paywall strategy applied by the local newspapers may be well fitted to stabilise print subscription figures and facilitate more tailored and better services for already existing customers, but far less suited for attracting new ones. The paywall is a short-sighted strategy, which drives away younger readers and paves the road for substitute offerings, particularly Facebook.

Keywords: business model, newspapers, paywall, user payment

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Authors: Bengi Hakguder Taze, Sevcan Unluturk

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Şalak apricot (Prunus armeniaca L., cv. Şalak) is a specific variety grown in Igdir, Turkey. The fruit has distinctive properties distinguish it from other cultivars, such as its unique size, color, taste and higher water content. Drying is the widely used method for preservation of apricots. However, fresh consumption is preferred for Şalak apricot instead of drying due to its low dry matter content. Higher amounts of water in the structure and climacteric nature make the fruit sensitive against rapid quality loss during storage. Hence, alternative processing methods need to be introduced to extend the shelf life of the fresh produce. Mild heat (MH) treatment is of great interest as it can reduce the microbial load and inhibit enzymatic activities. Therefore, the aim of this study was to evaluate the impact of mild heat treatment on the natural microflora found on Şalak apricot surfaces and some physical quality parameters of the fruit, such as color and firmness. For this purpose, apricot samples were treated at different temperatures between 40 and 60 ℃ for different periods ranging between 10 to 60 min using a temperature controlled water bath. Natural flora on the fruit surfaces was examined using standard plating technique both before and after the treatment. Moreover, any changes in color and firmness of the fruit samples were also monitored. It was found that control samples were initially containing 7.5 ± 0.32 log CFU/g of total aerobic plate count (TAPC), 5.8±0.31 log CFU/g of yeast and mold count (YMC), and 5.17 ± 0.22 log CFU/g of coliforms. The highest log reductions in TAPC and YMC were observed as 3.87-log and 5.8-log after the treatments at 60 ℃ and 50 ℃, respectively. Nevertheless, the fruit lost its characteristic aroma at temperatures above 50 ℃. Furthermore, great color changes (ΔE ˃ 6) were observed and firmness of the apricot samples was reduced at these conditions. On the other hand, MH treatment at 41 ℃ for 10 min resulted in 1.6-log and 0.91-log reductions in TAPC and YMC, respectively, with slightly noticeable changes in color (ΔE ˂ 3). In conclusion, application of temperatures higher than 50 ℃ caused undesirable changes in physical quality of Şalak apricots. Although higher microbial reductions were achieved at those temperatures, temperatures between 40 and 50°C should be further investigated considering the fruit quality parameters. Another strategy may be the use of high temperatures for short time periods not exceeding 1-5 min. Besides all, MH treatment with UV-C light irradiation can be also considered as a hurdle strategy for better inactivation results.

Keywords: color, firmness, mild heat, natural flora, physical quality, şalak apricot

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Authors: Yun-Chung Yu, Yan-Wen Wang, Min-Sheng Liao, Joe-Air Jiang, Yuen-Chung Lee

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This paper proposes to use a Long Range Wide Area Network (LoRaWAN) for a smart pest monitoring system which aims at the oriental fruit fly (Bactrocera dorsalis) to improve the communication efficiency of the system. The oriental fruit fly is one of the main pests in Southeast Asia and the Pacific Rim. Different smart pest monitoring systems based on the Internet of Things (IoT) architecture have been developed to solve problems of employing manual measurement. These systems often use Octopus II, a communication module following the 2.4GHz IEEE 802.15.4 ZigBee specification, as sensor nodes. The Octopus II is commonly used in low-power and short-distance communication. However, the energy consumption increase as the logical topology becomes more complicate to have enough coverage in the large area. By comparison, LoRaWAN follows the Low Power Wide Area Network (LPWAN) specification, which targets the key requirements of the IoT technology, such as secure bi-directional communication, mobility, and localization services. The LoRaWAN network has advantages of long range communication, high stability, and low energy consumption. The 433MHz LoRaWAN model has two superiorities over the 2.4GHz ZigBee model: greater diffraction and less interference. In this paper, The Octopus II module is replaced by a LoRa model to increase the coverage of the monitoring system, improve the communication performance, and prolong the network lifetime. The performance of the LoRa-based system is compared with a ZigBee-based system using three indexes: the packet receiving rate, delay time, and energy consumption, and the experiments are done in different settings (e.g. distances and environmental conditions). In the distance experiment, a pest monitoring system using the two communication specifications is deployed in an area with various obstacles, such as buildings and living creatures, and the performance of employing the two communication specifications is examined. The experiment results show that the packet receiving the rate of the LoRa-based system is 96% , which is much higher than that of the ZigBee system when the distance between any two modules is about 500m. These results indicate the capability of a LoRaWAN-based monitoring system in long range transmission and ensure the stability of the system.

Keywords: LoRaWan, oriental fruit fly, IoT, Octopus II

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Authors: Alice V. Brown, Patrick Egan, Dorothy Bagshaw, Jackie Oakley, Emma Vieira, Louise Southalan, Duc Dau, Lucy Spanswick, Lindey Andrews, Mandy Wilson, Jocelyn Jones

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Western Australia has recently adopted a 10-year plan to end homelessness across its State, with sections of the plan focused particularly on the Aboriginal and Torres Strait Islander population. In 2022, we engaged with 70-90 Aboriginal people experiencing homelessness in Perth, Western Australia, through qualitative interviews and creative methods, listening to their experiences of homelessness and their views on how services, State plans, and policies could better support them. This research was driven by the Aboriginal community through a Community Ownership Group of 16 Aboriginal Elders, elected by Elders’ groups, from across the Perth metropolitan area. The Community Ownership Group met every six weeks across the 15-month project timeline to guide the research team, endorse methods chosen, and provide richer context to research findings to ensure they adequately represent the experiences of Aboriginal people. These meetings were audio-recorded when possible and documented through meeting notes, verbal and visual minutes, and film, providing insights into homelessness from the perspective of Aboriginal Elders. In this paper, we compare the views of those experiencing homelessness with the views of the Aboriginal Elders -many of whom have experienced homelessness firsthand- and literature regarding how those experiencing homelessness can be better supported. We detail the ‘survival-directed thinking’ of those we engaged with who was in the throes of homelessness, leading them to focus more on immediate solutions such as food and housing. We then compare these narratives to Elders’ views that have been more regularly focused on connection to culture and long-term plans for healing homelessness, alongside immediate outreach -views also reflected in the literature. Through these comparisons, we highlight the importance of engaging both with those currently experiencing homelessness as well as with Aboriginal Elders as important cultural caretakers and authorities. We demonstrate how these varied voices uncover both long and short-term perspectives on how homelessness can be better managed in policy and service provision. We also highlight the potential role Aboriginal Elders can play in supporting the Aboriginal homeless community and their transition into housing.

Keywords: Aboriginal and Torres strait islander peoples, aboriginal elders, homelessness, community-led research

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Authors: Mehdi Shekarbeigi

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The consolidation of loose substrates as well as substrate layers through promoting stabilizing materials is one of the most commonly used road construction techniques. Cement, lime, and flax, as well as asphalt emulsion, are common materials used for soil stabilization to enhance the soil’s strength and durability properties. Cement could be simply used to stabilize permeable materials such as sand in a relatively short time threshold. In this research, typical Portland cement is selected for the stabilization of isotropic sand; the effect of static and cyclic loading on the behavior of these soils has been examined with various percentages of Portland cement. Thus, firstly, a soil’s general features are investigated, and then static tests, including direct cutting, density and single axis tests, and California Bearing Ratio, are performed on the samples. After that, the dynamic behavior of cement on silica sand with the same grain size is analyzed. These experiments are conducted on cement samples of 3, 6, and 9 of the same rates and ineffective limiting pressures of 0 to 1200 kPa with 200 kPa steps of the face according to American Society for Testing and Materials D 3999 standards. Also, to test the effect of temperature on molds and frost samples, 0, 5, 10, and 20 are carried out during 0, 5, 10, and 20-second periods. Results of the static tests showed that increasing the cement percentage increases the soil density and shear strength. The single-axis compressive strength increase is higher for samples with higher cement content and lower densities. The results also illustrate the relationship between single-axial compressive strength and cement weight parameters. Results of the dynamic experiments indicate that increasing the number of loading cycles and melting and freezing cycles enhances permeability and decreases the applied pressure. According to the results of this research, it could be stated that samples containing 9% cement have the highest amount of shear modulus and, therefore, decrease the permeability of soil. This amount could be considered as the optimal amount. Also, the enhancement of effective limited pressure from 400 to 800kPa increased the shear modulus of the sample by an average of 20 to 30 percent in small strains.

Keywords: cement, isotropic sands, static load, three-axis cycle, melting and freezing cycles

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Authors: Saeed Musaid H. Alzahrani

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The role of middle leaders, especially in primary schools, is a multi-faced role that has been subject to changes in nature over recent decades, with claims for more distributed leadership practices. This research examines the way 18 middle leaders in Saudi and English primary schools conceptualise their roles and responsibilities, and different factors influencing those roles and responsibilities. It begins from the premise that both the power of the role and the values of middle leaders are grounded in cultural and political bases, a belief held by the researcher as an 'insider' within the Saudi educational leadership context. The study consisted of a comparative analysis of the role and the responsibilities of middle leaders in Saudi primary schools and their equivalents in English primary schools. A purely qualitative methodological stance was adopted, using in-depth face-to-face semi-structured interviews, observations and document analysis. Middle leaders were asked to reflect deeply on their perceptions and understanding of their roles and explain what they thought influenced their daily practices and responsibilities. The findings suggest that the concept of middle leadership has been influenced by power imposed from above by political authority, via internal and external hierarchical structures, which shapes the nature of the role of the middle leaders and forces them to comply. Middle leaders seem to believe they have the power to make decisions and promote change, but these findings suggest that this is illusory. The power that keeps middle leaders performing is the power of their cultural and religious values. Those values are the resource to which they turn in their search for more energy when they lack support and are short of time taken. Middle leaders in Saudi, just like their equivalents in English schools must comply with the requirements of their role. However, Saudi middle leaders are given no leeway to make decisions or implement change, neither do they have the culture of collegiality that seems to give middle leaders in England more power over their resources and decisions. However, in neither educational setting have middle leaders been given the power to lead, so they remain managers rather than leaders. The findings of this research suggest that there are more similarities between the educational settings of Saudi and England than differences; and in the light of different factors identified in the study, suggest the establishment of a framework for middle leadership, in the hope of enhancing the way the role is practiced.

Keywords: middle leader, primary school, power, educational leadership, value, culture, model, Saudi Arabia, England

Procedia PDF Downloads 192

Authors: Caio E. G. Reis, Sara Wassell, Adriana L. Porto, Angélica A. Amato, Leslie J. C. Bluck, Teresa H. M. da Costa

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Background: Multiple epidemiologic studies have consistently reported association between increased coffee consumption and a lowered risk of Type 2 Diabetes Mellitus. However, the mechanisms behind this finding have not been fully elucidated. Objective: We investigate the effect of coffee (caffeinated and decaffeinated) on glucose effectiveness and insulin sensitivity using the stable isotope minimal model protocol with oral glucose administration in healthy men. Design: Fifteen healthy men underwent 5 arms randomized crossover single-blinding (researchers) clinical trial. They consumed decaffeinated coffee, caffeinated coffee (with and without sugar), and controls – water (with and without sugar) followed 1 hour by an oral glucose tolerance test (75 g of available carbohydrate) with intravenous labeled dosing interpreted by the two compartment minimal model (225 minutes). One-way ANOVA with Bonferroni adjustment were used to compare the effects of the tested beverages on glucose metabolism parameters. Results: Decaffeinated coffee resulted in 29% and 85% higher insulin sensitivity compared with caffeinated coffee and water, respectively, and the caffeinated coffee showed 15% and 60% higher glucose effectiveness compared with decaffeinated coffee and water, respectively. However, these differences were not significant (p > 0.10). In overall analyze (0 – 225 min) there were no significant differences on glucose effectiveness, insulin sensitivity, and glucose and insulin area under the curve between the groups. The beneficial effects of coffee did not seem to act in the short-term (hours) on glucose metabolism parameters mainly on insulin sensitivity indices. The benefits of coffee consumption occur in the long-term (years) as has been shown in the reduction of Type 2 Diabetes Mellitus risk in epidemiological studies. The clinical relevance of the present findings is that there is no need to avoid coffee as the drink choice for healthy people. Conclusions: The findings of this study demonstrate that the consumption of caffeinated and decaffeinated coffee with or without sugar has no acute effects on glucose metabolism in healthy men. Further researches, including long-term interventional studies, are needed to fully elucidate the mechanisms behind the coffee effects on reduced risk for Type 2 Diabetes Mellitus.

Keywords: coffee, diabetes mellitus type 2, glucose, insulin

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Authors: Jansirani Natarajan, Mickael Antoinne Joseph

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The COVID-19 pandemic has interrupted face-to-face education and forced universities into an emergency remote teaching curriculum over a short duration. This abrupt transition in the Spring 2020 semester left both faculty and students without proper preparation for continuing higher education in an online environment. Online learning took place in different formats, including fully synchronous, fully asynchronous, and blended in our university through the e-learning platform MOODLE. Studies have shown that students’ engagement, is a critical factor for optimal online teaching. Very few studies have assessed online engagement with ERT during the COVID-19 pandemic. Purpose: Therefore, this study, sought to understand how the sudden transition to emergency remote teaching impacted nursing students’ engagement with online courses in a Middle Eastern public university. Method: A cross-sectional descriptive research design was adopted in this study. Data were collected through a self-reported online survey using Dixon’s online students’ engagement questionnaire from a sample of 177 nursing students after the ERT learning semester. Results The maximum possible engagement score was 95, and the maximum scores in the domains of skills engagement, emotional engagement, participation engagement, and performance engagement were 30, 25, 30, and 10 respectively. Dixson (2010) noted that a mean item score of ≥3.5 (total score of ≥66.5) represents a highly engaged student. The majority of the participants were females (71.8%) and 84.2% were regular BSN students. Most of them (32.2%) were second-year students and 52% had a CGPA between 2 and 3. Most participants (56.5%) had low engagement scores with ERT learning during the COVID lockdown. Among the four engagement domains, 78% had low engagement scores for the participation domain. There was no significant association found between the engagement and the demographic characteristics of the participants. Conclusion The findings supported the importance of engaging students in all four categories skill, emotional, performance, and participation. Based on the results, training sessions were organized for faculty on various strategies for engaging nursing students in all domains by using the facilities available in the MOODLE (online e-learning platform). It added value as a dashboard of information regarding ERT for the administrators and nurse educators to introduce numerous active learning strategies to improve the quality of teaching and learning of nursing students in the University.

Keywords: engagement, perception, emergency remote learning, COVID-19

Procedia PDF Downloads 63

Authors: Morteza Rahbar Taramsari, Arya Mahdavi Baramchi, Mercedeh Enshaei, Ghazaleh Keshavarzi Baramchi

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Introduction: Malingering is one of the most challenging issues in the forensic psychology and imposes a heavy financial burden on health care and legal systems. It seems that some mental and personality abnormalities might have a crucial role in developing this condition. Materials and Methods: In this cross-sectional study, we aimed to assess 100 malingering clients of Gilan province general office of forensic medicine, all filled the related questionnaires. The data about some psychometric characteristics were collected through the 71-items version- short form- of Minnesota Multiphasic Personality Inventory (MMPI) questionnaire and the personality traits were assessed by NEO Personality Inventory-Revised (NEO PI-R) - including 240 items- as a reliable and accurate measure of the five domains of personality. Results: The 100 malingering clients (55 males and 45 females) ranged from 23 to 45 (32+/- 5.6) years old. Regarding marital status, 36% were single, 57% were married and 7% were divorced. Almost two-thirds of the participants (64%) were unemployed, 21% were self-employed and the rest of them were employed. The data of MMPI clinical scales revealed that the mean (SD) T score of Hypochondrias (Hs) was 67(9.2), Depression (D) was 87(7.9), Hysteria (Hy) was 74(5.8), Psychopathic Deviate (Pd) was 62(8.5), Masculinity-Feminity (MF) was 76(8.4), Paranoia (Pa) was 62(4.5), Psychasthenia (Pt) was 80(7.9), Schizophrenia (Sc) was 69(6.8), Hypomania (Ma) was 64(5.9)and Social Introversion (Si) was 58(4.3). NEO PI-R test showed five domains of personality. The mean (SD) T score of Neuroticism was 65(9.2), Extraversion was 51(7.9), Openness was 43(5.8), Agreeableness was 35(3.4) and Conscientiousness was 42(4.9). Conclusion: According to MMPI test in our malingering clients, Hypochondriasis (Hs), depression (D), Hysteria (Hy), Muscularity-Feminity (MF), Psychasthenia (Pt) and Schizophrenia (Sc) had high scores (T >= 65) which means pathological range and psychological significance. Based on NEO PI-R test Neuroticism was in high range, on the other hand, Openness, Agreeableness, and Conscientiousness were in low range. Extroversion was in average range. So it seems that malingerers require basic evaluations of different psychological fields. Additional research in this area is needed to provide stronger evidence of the possible positive effects of the mentioned factors on malingering.

Keywords: malingerers, mental profile, MMPI, NEO PI-R, personality profile

Procedia PDF Downloads 262

Authors: Alejandra Castillo-Arias, Santiago Amézquita-Murcia, Golber Carvajal-Lavi, Carlos M. Zuluaga-Domínguez

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The intricate relationship between health and nutrition has driven the food industry to seek healthier and more sustainable alternatives. A key strategy currently employed is the reduction of saturated fats and the incorporation of ingredients that align with new consumer trends. Modified starch, a polysaccharide widely used in baking, also serves as a functional ingredient to boost dietary fiber content. However, its use in puff pastry remains challenging due to the technological difficulties in achieving a buttery pastry with the necessary strength to create thin, flaky layers. This study explored the potential of incorporating modified starch into puff pastry formulations. To evaluate the physicochemical properties of wheat flour mixed with modified starch, five different flour samples were prepared: T1, T2, T3, and T4, containing 10g, 20g, 30g, and 40g of modified starch per 100 g mixture, respectively, alongside a control sample (C) with no added starch. The analysis focused on various physicochemical indices, including the Water Absorption Index (WAI), Water Solubility Index (WSI), Swelling Power (SP), and Water Retention Capacity (WRC). The puff pastry was further characterized by color measurement and sensory analysis. For the preparation of the puff pastry dough, the flour, modified starch, and salt were mixed, followed by the addition of water until a homogenous dough was achieved. The margarine was later incorporated into the dough, which was folded and rolled multiple times to create the characteristic layers of puff pastry. The dough was then cut into equal pieces, baked at 170°C, and allowed to cool. The results indicated that the addition of modified starch did not significantly alter the specific volume or texture of the puff pastries, as reflected by the stable WAI and SP values across the samples. However, the WRC increased with higher starch content, highlighting the hydrophilic nature of the modified starch, which necessitated additional water during dough preparation. Color analysis revealed significant variations in the L* (lightness) and a* (red-green) parameters, with no consistent relationship between the modified starch treatments and the control. However, the b* (yellow-blue) parameter showed a strong correlation across most samples, except for treatment T3. Thus, modified starch affected the a* component of the CIELAB color spectrum, influencing the reddish hue of the puff pastries. Variations in baking time due to increased water content in the dough likely contributed to differences in lightness among the samples. Sensory analysis revealed that consumers preferred the sample with a 20% starch substitution (T2), which was rated similarly to the control in terms of texture. However, treatment T3 exhibited unusual behavior in texture analysis, and the color analysis showed that treatment T1 most closely resembled the control, indicating that starch addition is most noticeable to consumers in the visual aspect of the product. In conclusion, while the modified starch successfully maintained the desired texture and internal structure of puff pastry, its impact on water retention and color requires careful consideration in product formulation. This study underscores the importance of balancing product quality with consumer expectations when incorporating modified starches in baked goods.

Keywords: consumer preferences, modified starch, physicochemical properties, puff pastry

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Authors: Dejenie Birile Gemeda, Wilhelm Stork

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The power system is one of the most important systems in modern society. The existing power system is approaching the critical operating limits as views of several power system operators. With the increase of load demand, high capacity and long transmission networks are widely used to meet the requirement. With the integration of renewable energies such as wind and solar, the uncertainty, intermittence bring bigger challenges to the operation of power systems. These dynamic uncertainties in the power system lead to power disturbances. The disturbances in a heavily stressed power system cause distance relays to mal-operation or false alarms during post fault power oscillations. This unintended operation of these relays may propagate and trigger cascaded trappings leading to total power system blackout. This is due to relays inability to take an appropriate tripping decision based on ensuing power swing. According to the N-1 criterion, electric power systems are generally designed to withstand a single failure without causing the violation of any operating limit. As a result, some overloaded components such as overhead transmission lines can still work for several hours under overload conditions. However, when a large power swing happens in the power system, the settings of the distance relay of zone 3 may trip the transmission line with a short time delay, and they will be acting so quickly that the system operator has no time to respond and stop the cascading. Misfiring of relays in absence of fault due to power swing may have a significant loss in economic performance, thus a loss in revenue for power companies. This research paper proposes a method to distinguish stable power swing from unstable using dynamic line rating (DLR) in response to power swing or disturbances. As opposed to static line rating (SLR), dynamic line rating support effective mitigation actions against propagating cascading outages in a power grid. Effective utilization of existing transmission lines capacity using machine learning DLR predictions will improve the operating point of distance relay protection, thus reducing unintended power outages due to power swing.

Keywords: blackout, cascading outages, dynamic line rating, power swing, overhead transmission lines

Procedia PDF Downloads 143

Authors: M. Moyzykh, I. Klichuk, L. Sabirov, D. Kolomentseva, E. Magommedov

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Modern city electrical grids are forced to increase their density due to the increasing number of customers and requirements for reliability and resiliency. However, progress in this direction is often limited by the capabilities of existing network equipment. New energy sources or grid connections increase the level of short-circuit currents in the adjacent network, which can exceed the maximum rating of equipment–breaking capacity of circuit breakers, thermal and dynamic current withstand qualities of disconnectors, cables, and transformers. Superconducting fault current limiter (SFCL) is a modern solution designed to deal with the increasing fault current levels in power grids. The key feature of this device is its instant (less than 2 ms) limitation of the current level due to the nature of the superconductor. In 2019 Moscow utilities installed SuperOx SFCL in the city power grid to test the capabilities of this novel technology. The SFCL became the first SFCL in the Russian energy system and is currently the most powerful SFCL in the world. Modern SFCL uses second-generation high-temperature superconductor (2G HTS). Despite its name, HTS still requires low temperatures of liquid nitrogen for operation. As a result, Moscow SFCL is built with a cryogenic system to provide cooling to the superconductor. The cryogenic system consists of three cryostats that contain a superconductor part and are filled with liquid nitrogen (three phases), three cryocoolers, one water chiller, three cryopumps, and pressure builders. All these components are controlled by an automatic control system. SFCL has been continuously operating on the city grid for over three years. During that period of operation, numerous faults occurred, including cryocooler failure, chiller failure, pump failure, and others (like a cryogenic system power outage). All these faults were eliminated without an SFCL shut down due to the specially designed cryogenic system backups and quick responses of grid operator utilities and the SuperOx crew. The paper will describe in detail the results of SFCL operation and cryogenic system maintenance and what measures were taken to solve and prevent similar faults in the future.

Keywords: superconductivity, current limiter, SFCL, HTS, utilities, cryogenics

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Authors: Epameinondas Xanthakis, Erik Kaunisto, Alain Le-Bail, Lilia Ahrné

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Fruits and vegetables are characterized as perishable food matrices due to their short shelf life as several deterioration mechanisms are being involved. Prior to the common preservation methods like freezing or canning, fruits and vegetables are being blanched in order to inactivate deteriorative enzymes. Both conventional blanching pretreatments and conventional freezing methods hide drawbacks behind their beneficial impacts on the preservation of those matrices. Conventional blanching methods may require longer processing times, leaching of minerals and nutrients due to the contact with the warm water which in turn leads to effluent production with large BOD. An important issue of freezing technologies is the size of the formed ice crystals which is also critical for the final quality of the frozen food as it can cause irreversible damage to the cellular structure and subsequently to degrade the texture and the colour of the product. Herein, the developed microwave blanching methodology and the results regarding quality aspects and enzyme inactivation will be presented. Moreover, heat transfer phenomena, mass balance, temperature distribution, and enzyme inactivation (such as Pectin Methyl Esterase and Ascorbic Acid Oxidase) of our microwave blanching approach will be evaluated based on measurements and computer modelling. The present work is part of the COLDμWAVE project which aims to the development of an innovative environmentally sustainable process for blanching and freezing of fruits and vegetables with improved textural and nutritional quality. In this context, COLDµWAVE will develop tailored equipment for MW blanching of vegetables that has very high energy efficiency and no water consumption. Furthermore, the next steps of this project regarding the development of innovative pathways in MW assisted freezing to improve the quality of frozen vegetables, by exploring in depth previous results acquired by the authors, will be presented. The application of MW assisted freezing process on fruits and vegetables it is expected to lead to improved quality characteristics compared to the conventional freezing. Acknowledgments: COLDμWAVE has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grand agreement No 660067.

Keywords: blanching, freezing, fruits, microwave blanching, microwave

Procedia PDF Downloads 267

Authors: Zahra Shokrolahi, Mohammad Reza Atashzar

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The goals of treating patients with breast cancer are to cure the disease, prolong survival, and improve quality of life. Immune cells in the tumor microenvironment have an important role in regulating tumor progression. The term of cellular immunotherapy refers to the administration of living cells to a patient; this type of immunotherapy can be active, such as a dendritic cell (DC) vaccine, in that the cells can stimulate an anti-tumour response in the patient, or the therapy can be passive, whereby the cells have intrinsic anti-tumour activity; this is known as adoptive cell transfer (ACT) and includes the use of autologous or allogeneic lymphocytes that may, or may not, be modified. The most important breast cancer cellular immunotherapies involving the use of T cells and natural killer (NK) cells in adoptive cell transfer, as well as dendritic cells vaccines. T cell-based therapies including tumour-infiltrating lymphocytes (TILs), engineered TCR-T cells, chimeric antigen receptor (CAR T cell), Gamma-delta (γδ) T cells, natural killer T (NKT) cells. NK cell-based therapies including lymphokine-activated killers (LAK), cytokine-induced killer (CIK) cells, CAR-NK cells. Adoptive cell therapy has some advantages and disadvantages some. TILs cell strictly directed against tumor-specific antigens but are inactive against tumor changes due to immunoediting. CIK cell have MHC-independent cytotoxic effect and also need concurrent high dose IL-2 administration. CAR T cell are MHC-independent; overcome tumor MHC molecule downregulation; potent in recognizing any cell surface antigen (protein, carbohydrate or glycolipid); applicable to a broad range of patients and T cell populations; production of large numbers of tumor-specific cells in a moderately short period of time. Meanwhile CAR T cells capable of targeting only cell surface antigens; lethal toxicity due to cytokine storm reported. Here we present the most popular cancer cellular immunotherapy approaches and discuss their clinical relevance referring to data acquired from clinical trials .To date, clinical experience and efficacy suggest that combining more than one immunotherapy interventions, in conjunction with other treatment options like chemotherapy, radiotherapy and targeted or epigenetic therapy, should guide the way to cancer cure.

Keywords: breast cancer , cell therapy , CAR T cell , CIK cells

Procedia PDF Downloads 130

Authors: Jasna Hudek-Knezevic, Igor Kardum, Nada Krapic, Martina Jurcic

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The aim of this study was to examine the effects of self- and partner reported attachment orientations on self-reported mate retention behaviors in romantic couples using the actor-partner interdependence model. The study was carried out on 187 heterosexual couples aged from 18 to 35 years, with an average relationship length of 4.5 years. Participants were asked to complete the revised scale of adult attachment and short form of mate retention inventory. Actor and partner effects of self- and partner reported anxious and avoidant attachment orientations on mate retention categories (direct guarding, intersexual negative inducements, positive inducements, public signals of possession and intrasexual negative inducements) and domains (cost-inflicting and benefit-provisioning), as well on overall mate retention were examined. Actor effects for women estimate whether their attachment orientations predict their own mate retention behaviors, whereas men’s actor effects estimate whether their attachment orientations predict their own mate retention behaviors. Women’s partner effects estimate whether their attachment orientations predict their partner’s mate retention behaviors, whereas men’s partner effects estimate whether their attachment orientations predict their partner’s mate retention behaviors. The use of two data sources, self- and partner reports, allow the control of the effects of common method variance when exploring actor and partner effects. Positive actor and partner effects of anxious attachment, as well as negative actor and partner effects of avoidant attachment on mate retention, were expected. In other words, it was expected that more anxiously attached individuals themselves, as well as their partners, will use mate retention behaviors more frequently. On the other hand, more avoidantly attached individuals themselves, as well as their partners, will use mate retention behaviors less frequently. These hypotheses were partially confirmed. The results showed that the strongest and most consistent effects across both data sources were men’s actor effects on the cost-inflicting mate retention domain, and especially on two mate retention categories, direct guarding, and intersexual negative inducements. Additionally, a consistent positive partner effect of men’s anxious attachment orientations on direct guarding was also obtained. Avoidant attachment orientation exerted few and inconsistent actor and partner effects on mate retention domains and categories. The results are explained by theoretical propositions addressing the effects of attachment orientations on an interpersonal romantic relationship in early adulthood.

Keywords: actor and partner effects, attachment orientations, dyadic analysis, mate retention behavior

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Authors: Gabriel Vusanimuzi Nkomo

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The majority of soils in communal areas of Zimbabwe are sandy and inherently infertile and sustainable cultivation is not feasible without addition of plant nutrients. Most farmers find it difficult to raise the capital required for investments in mineral fertilizer and find it cheaper to use low nutrition animal manure. An experiment was conducted to determine the effects of nitrokara biofertiliser on early growth, development and maize yield while also comparing nitrokara biofertiliser on availability of nitrogen and phosphorous in soil. The experiment was conducted at Africa University Farm. The experiment had six treatments (nitrokara +300kg/ha Compound D, nitrokara+ 300kg/ha Compound D(7N;14P;7K) + 75kg/ha Ammonium Nitrate(AN), nitrokara +300kg/ha Compound D +150kg AN, nitrokara +300kg/ha Compound D +225kg/ha AN, nitrokara +300kg/ha Compound D + 300 kg/ha AN and 0 nitrokara+300kg/ha Compound D +0 AN). Early maturing SC 403 maize (Zea mays) was inoculated with nitrokara and a compound mineral fertilizer at 300 kg/ha at planting while ammonium nitrate was applied at 45 days after planting. There were no significant differences (P > 0.05) on emergence % from 5days up to 10 days after planting using maize seed inoculated with nitrokara. Emergence percentage varied with the number of days. At 5 days the emergence % was 62% to a high of 97 % at 10 days after emergence among treatments. There were no significant differences (P > 0.05) on plant biomass on treatments 1 to 6 at 4 weeks after planting as well as at 8 weeks after planting. There were no significant differences among the treatments on the availability of nitrogen after 6 weeks (P > 0.05). However at 8 and 10 weeks after planting there were significant differences among treatments on nitrogen availability (P < 0.05). There were no significant differences among the treatments at week 6 after planting on soil pH (p > 0.05). However there were significant differences among treatments pH at weeks 9 and 12 (p < 0.05). There were significant differences among treatments on phosphorous availability at 6, 8 and 10 weeks after planting (p < 0.05). There were no significant differences among treatments on stem diameter at 3 and 6 weeks after planting (p > 0.05).However at 9 and 12 weeks after planting there were significant differences among treatments on stem diameter (p < 0.05).There were no significant differences among treatments on plant height from week 3 up to week 6 on plant height (P > 0.05).However there were significant differences among treatments at week 9 and 12 (p < 0.05). There were significant differences among treatments on days to early, 50% and 100% anthesis (P < 0.05). There were significant differences during early, 50% and 100% days to silking among the treatments (P < 0.05).Also there were significant differences during early, 50% and 100% days to silking among the treatments (P < 0.05).The study revealed that inoculation of nitrokara biofertiliser at planting with subsequent addition of ammonium nitrate has a positive effect on maize crop development and yield.

Keywords: nitrokara, biofertiliser, symbiotic, plant biomass, inoculated

Procedia PDF Downloads 551

Authors: Alireza Rahpeyma

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One of the most significant challenges faced by cities is inefficient and deteriorated urban fabric. Deteriorated areas bring about numerous issues, including economic, social, physical, and infrastructural problems, sewage management, environmental concerns, and security issues. One of the crucial necessities of modern urban life is the revitalization and renovation of these urban fabrics. Another important aspect is preserving a cohesive cultural and social identity during the urban renewal process. Urban renovation and upgrading are not a one-time occurrence but rather an ongoing process that ultimately needs to become ingrained in the system. This process is not swift; it involves sensitive and intricate stages that require well-designed plans within short, medium, and long-term timeframes. To revitalize dilapidated areas, a comprehensive understanding of the urban region's sustainability is essential. The goal of this study is to provide a suitable model for the upgrading and renewal of areas 2, 4, 5, 7, 8, and 10 in Tehran, preserving the heritage within these urban fabrics (urban assets), including the valuable morphologies of these areas, to prevent financial wastage. This study was conducted descriptively and analytically using the SWOT technique and GIS software. The research results regarding urban upgrading and renewal bring about the following points: 1) Urban upgrading and renewal ensure satisfactory efficiency, justice, environmental quality, safety and security, hygiene, sewage management, and the comfort and aesthetics of urban spaces. 2) Employing the above processes in old city centers re-establishes the historical and cultural connection between people and their past, a past that is evolving and improving and will not repeat itself. 3) Despite the expansion and growth of Iranian cities, cultural and national identity can be preserved by adhering to healthy urban revitalization principles. 4) Proper urban upgrading and renewal prevent social fragmentation, deviant behavioral patterns, psychological and occupational disorders, and financial losses. In general, preserving the identity and urban life in renovation and upgrading must be comprehensive, encompassing various dimensions, including physical, social, economic, political, and administrative aspects.

Keywords: dilapidated areas, renovation, sustainable reconstruction, Tehran-Iran

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Authors: Varun Kumar, Chandra Shakher

Abstract:

Micro-optical components such as microlenses and microlens array have numerous engineering and industrial applications for collimation of laser diodes, imaging devices for sensor system (CCD/CMOS, document copier machines etc.), for making beam homogeneous for high power lasers, a critical component in Shack-Hartmann sensor, fiber optic coupling and optical switching in communication technology. Also micro-optical components have become an alternative for applications where miniaturization, reduction of alignment and packaging cost are necessary. The compliance with high-quality standards in the manufacturing of micro-optical components is a precondition to be compatible on worldwide markets. Therefore, high demands are put on quality assurance. For quality assurance of these lenses, an economical measurement technique is needed. For cost and time reason, technique should be fast, simple (for production reason), and robust with high resolution. The technique should provide non contact, non-invasive and full field information about the shape of micro- optical component under test. The interferometric techniques are noncontact type and non invasive and provide full field information about the shape of the optical components. The conventional interferometric technique such as holographic interferometry or Mach-Zehnder interferometry is available for characterization of micro-lenses. However, these techniques need more experimental efforts and are also time consuming. Digital holography (DH) overcomes the above described problems. Digital holographic microscopy (DHM) allows one to extract both the amplitude and phase information of a wavefront transmitted through the transparent object (microlens or microlens array) from a single recorded digital hologram by using numerical methods. Also one can reconstruct the complex object wavefront at different depths due to numerical reconstruction. Digital holography provides axial resolution in nanometer range while lateral resolution is limited by diffraction and the size of the sensor. In this paper, Mach-Zehnder based digital holographic interferometric microscope (DHIM) system is used for the testing of transparent microlenses. The advantage of using the DHIM is that the distortions due to aberrations in the optical system are avoided by the interferometric comparison of reconstructed phase with and without the object (microlens array). In the experiment, first a digital hologram is recorded in the absence of sample (microlens array) as a reference hologram. Second hologram is recorded in the presence of microlens array. The presence of transparent microlens array will induce a phase change in the transmitted laser light. Complex amplitude of object wavefront in presence and absence of microlens array is reconstructed by using Fresnel reconstruction method. From the reconstructed complex amplitude, one can evaluate the phase of object wave in presence and absence of microlens array. Phase difference between the two states of object wave will provide the information about the optical path length change due to the shape of the microlens. By the knowledge of the value of the refractive index of microlens array material and air, the surface profile of microlens array is evaluated. The Sag of microlens and radius of curvature of microlens are evaluated and reported. The sag of microlens agrees well within the experimental limit as provided in the specification by the manufacturer.

Keywords: micro-optics, microlens array, phase map, digital holographic interferometric microscopy

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