Search results for: effective temperature

Authors: Ibrahim Rassoul, A. Serir, E-K. Si Ahmed, J. Legrand

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The acronym PEM refers to Proton Exchange Membrane or alternatively Polymer Electrolyte Membrane. Due to its high efficiency, low operating temperature (30–80 °C), and rapid evolution over the past decade, PEMFCs are increasingly emerging as a viable alternative clean power source for automobile and stationary applications. Before PEMFCs can be employed to power automobiles and homes, several key technical challenges must be properly addressed. One technical challenge is elucidating the mechanisms underlying water transport in and removal from PEMFCs. On one hand, sufficient water is needed in the polymer electrolyte membrane or PEM to maintain sufficiently high proton conductivity. On the other hand, too much liquid water present in the cathode can cause “flooding” (that is, pore space is filled with excessive liquid water) and hinder the transport of the oxygen reactant from the gas flow channel (GFC) to the three-phase reaction sites. The experimental transparent fuel cell used in this work was designed to represent actual full scale of fuel cell geometry. According to the operating conditions, a number of flow regimes may appear in the microchannel: droplet flow, blockage water liquid bridge /plug (concave and convex forms), slug/plug flow and film flow. Some of flow patterns are new, while others have been already observed in PEMFC microchannels. An algorithm in MATLAB was developed to automatically determine the flow structure (e.g. slug, droplet, plug, and film) of detected liquid water in the test microchannels and yield information pertaining to the distribution of water among the different flow structures. A video processing algorithm was developed to automatically detect dynamic and static liquid water present in the gas channels and generate relevant quantitative information. The potential benefit of this software allows the user to obtain a more precise and systematic way to obtain measurements from images of small objects. The void fractions are also determined based on images analysis. The aim of this work is to provide a comprehensive characterization of two-phase flow in an operating fuel cell which can be used towards the optimization of water management and informs design guidelines for gas delivery microchannels for fuel cells and its essential in the design and control of diverse applications. The approach will combine numerical modeling with experimental visualization and measurements.

Keywords: polymer electrolyte fuel cell, air-water two phase flow, gas diffusion layer, microchannels, advancing contact angle, receding contact angle, void fraction, surface tension, image processing

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Authors: Elaf Ahmed, Shahid Rasul, Ohoud Alharbi, Peng Wang

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Ultra-Small Nanoparticles of metals (USNPs) have attracted the attention from the perspective of both basic and developmental science in a wide range of fields. These NPs exhibit electrical, optical, magnetic, and catalytic phenomena. In addition, they are considered effective catalysts because of their enormously large surface area. Many chemical methods of synthesising USNPs are reported. However, the drawback of these methods is the use of different capping agents and ligands in the process of the production such as Polyvinylpyrrolidone, Thiol and Ethylene Glycol. In this research ultra-small nanoparticles of gold, palladium and platinum metal have been successfully produced using electrochemically active biofilm (EAB) after optimising the pH of the media. The production of ultra-small nanoparticles has been conducted in a reactor using a simple two steps method. Initially biofilm was grown on the surface of a carbon paper for 7 days using Shewanella Loihica bacteria. Then, biofilm was employed to synthesise platinum, palladium and gold nanoparticles in water using sodium lactate as electron donor without using any toxic chemicals at mild operating conditions. Electrochemically active biofilm oxidise the electron donor and produces electrons in the solution. Since these electrons are a strong reducing agent, they can reduce metal precursors quite effectively and quickly. The As-synthesized ultra-small nanoparticles have a size range between (2-7nm) and showed excellent catalytic activity on the degradation of methyl orange. The growth of metal USNPs is strongly related to the condition of the EAB. Where using low pH for the synthesis was not successful due to the fact that it might affect and destroy the bacterial cells. However, increasing the pH to 7 and 9, led to the successful formation of USNPs. By changing the pH value, we noticed a change in the size range of the produced NPs. The EAB seems to act as a Nano factory for the synthesis of metal nanoparticles by offering a green, sustainable and toxic free synthetic route without the use of any capping agents or ligands and depending only on their respiration pathway.

Keywords: electrochemically active biofilm, electron donor, shewanella loihica, ultra-small nanoparticles

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Authors: Aditi Taunk, George Iskander, Kitty Ka Kit Ho, Mark Willcox, Naresh Kumar

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Bacterial infections on biomaterial implants and medical devices accounts for 60-70% of all hospital acquired infections (HAIs). Treatment or removal of these infected devices results in high patient mortality and morbidity along with increased hospital expenses. In addition, with no effective strategies currently available and rapid development of antibacterial resistance has made device-related infections extremely difficult to treat. Therefore, in this project we have developed biomaterial surfaces using antibacterial compounds that inhibit biofilm formation by interfering with the bacterial communication mechanism known as quorum sensing (QS). This study focuses on covalent attachment of potent quorum sensing (QS) inhibiting compounds, halogenated furanones (FUs) and dihydropyrrol-2-ones (DHPs), onto glass surfaces. The FUs were attached by photoactivating the azide groups on the surface, and the acid functionalized DHPs were immobilized on amine surface via EDC/NHS coupling. The modified surfaces were tested in vitro against pathogenic organisms such as Staphylococcus aureus and Pseudomonas aeruginosa using confocal laser scanning microscopy (CLSM). Successful attachment of compounds on the substrates was confirmed by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The antibacterial efficacy was assessed, and significant reduction in bacterial adhesion and biofilm formation was observed on the FU and DHP coated surfaces. The activity of the coating was dependent upon the type of substituent present on the phenyl group of the DHP compound. For example, the ortho-fluorophenyl DHP (DHP-2) exhibited 79% reduction in bacterial adhesion against S. aureus and para-fluorophenyl DHP (DHP-3) exhibited 70% reduction against P. aeruginosa. The results were found to be comparable to DHP coated surfaces prepared in earlier study via Michael addition reaction. FUs and DHPs were able to retain their in vitro antibacterial efficacy after covalent attachment via azide chemistry. This approach is a promising strategy to develop efficient antibacterial biomaterials to reduce device related infections.

Keywords: antibacterial biomaterials, biomedical device-related infections, quorum sensing, surface functionalization

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Authors: Zhaoyang Liu

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It has been highly desired to develop a high-performance membrane for separating oil/water emulsions with the combined features of high water flux, high oil separation efficiency, and high mechanical stability. Here, we demonstrated a design for high-performance membranes constructed with ultra-long titanate nanofibers (over 30 µm in length)/cellulose microfibers. An integrated network membrane was achieved with these ultra-long nano/microfibers, contrast to the non-integrated membrane constructed with carbon nanotubes (5 µm in length)/cellulose microfibers. The morphological properties of the prepared membranes were characterized by A FEI Quanta 400 (Hillsboro, OR, United States) environmental scanning electron microscope (ESEM). The hydrophilicity, underwater oleophobicity and oil adhesion property of the membranes were examined using an advanced goniometer (Rame-hart model 500, Succasunna, NJ, USA). More specifically, the hydrophilicity of membranes was investigated by analyzing the spreading process of water into membranes. A filtration device (Nalgene 300-4050, Rochester, NY, USA) with an effective membrane area of 11.3 cm² was used for evaluating the separation properties of the fabricated membranes. The prepared oil-in-water emulsions were poured into the filtration device. The separation process was driven under vacuum with a constant pressure of 5 kPa. The filtrate was collected, and the oil content in water was detected by a Shimadzu total organic carbon (TOC) analyzer (Nakagyo-ku, Kyoto, Japan) to examine the separation efficiency. Water flux (J) of the membrane was calculated by measuring the time needed to collect some volume of permeate. This network membrane demonstrated good mechanical flexibility and robustness, which are critical for practical applications. This network membrane also showed high separation efficiency (99.9%) for oil/water emulsions with oil droplet size down to 3 µm, and meanwhile, has high water permeation flux (6.8 × 10³ L m⁻² h⁻¹ bar⁻¹) at low operation pressure. The high water flux is attributed to the interconnected scaffold-like structure throughout the whole membrane, while the high oil separation efficiency is attributed to the nanofiber-made nanoporous selective layer. Moreover, the economic materials and low-cost fabrication process of this membrane indicate its great potential for large-scale industrial applications.

Keywords: membrane, inorganic nanofibers, oil/water separation, emulsions

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Authors: Jéssica Bernegossi, Lívia Nordi Dovigo, Marlus Chorilli

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Mucoadhesive liquid crystalline systems are emerging how delivery systems for oral cavity. These systems are interesting since they facilitate the targeting of medicines and change the release enabling a reduction in the number of applications made by the patient. The buccal mucosa is permeable besides present a great blood supply and absence of first pass metabolism, it is a good route of administration. It was developed two systems liquid crystals utilizing as surfactant the ethyl alcohol ethoxylated and propoxylated (30%) as oil phase the oleic acid (60%), and the aqueous phase (10%) dispersion of polymer polyethylenimine (0.5%) or dispersion of polymer poloxamer 407 (16%), with the intention of applying the buccal mucosa. Initially, was performed for characterization of systems the conference by polarized light microscopy and rheological analysis. For the preparation of the systems the components described was added above in glass vials and shaken. Then, 30 and 100% artificial saliva were added to each prepared formulation so as to simulate the environment of the oral cavity. For the verification of the system structure, aliquots of the formulations were observed in glass slide and covered with a coverslip, examined in polarized light microscope (PLM) Axioskop - Zeizz® in 40x magnifier. The formulations were also evaluated for their rheological profile Rheometer TA Instruments®, which were obtained rheograms the selected systems employing fluency mode (flow) in temperature of 37ºC (98.6ºF). In PLM, it was observed that in formulations containing polyethylenimine and poloxamer 407 without the addition of artificial saliva was observed dark-field being indicative of microemulsion, this was also observed with the formulation that was increased with 30% of the artificial saliva. In the formulation that was increased with 100% simulated saliva was shown to be a system structure since it presented anisotropy with the presence of striae being indicative of hexagonal liquid crystalline mesophase system. Upon observation of rheograms, both systems without the addition of artificial saliva showed a Newtonian profile, after addition of 30% artificial saliva have been given a non-Newtonian behavior of the pseudoplastic-thixotropic type and after adding 100% of the saliva artificial proved plastic-thixotropic. Furthermore, it is clearly seen that the formulations containing poloxamer 407 have significantly larger (15-800 Pa) shear stress compared to those containing polyethyleneimine (5-50 Pa), indicating a greater plasticity of these. Thus, it is possible to observe that the addition of saliva was of interest to the system structure, starting from a microemulsion for a liquid crystal system, thereby also changing thereby its rheological behavior. The systems have promising characteristics as controlled release systems to the oral cavity, as it features good fluidity during its possible application and greater structuring of the system when it comes into contact with environmental saliva.

Keywords: liquid crystal system, poloxamer 407, polyethylenimine, rheology

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Authors: Ksenija Taški-Ajdukovic, Nevena Nagl, Živko Ćurčić, Dario Danojević

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Information about genetic diversity of sugar beet parental populations is of a great importance for hybrid breeding programs. The aim of this research was to evaluate genetic diversity among and within populations and lines of diploid sugar beet pollinators, by using SSR markers. As plant material were used eight pollinators originating from three USDA-ARS breeding programs and four pollinators from Institute of Field and Vegetable Crops, Novi Sad. Depending on the presence of self-fertility gene, the pollinators were divided into three groups: autofertile (inbred lines), autosterile (open-pollinating populations), and group with partial presence of autofertility gene. A total of 40 SSR primers were screened, out of which 34 were selected for the analysis of genetic diversity. A total of 129 different alleles were obtained with mean value 3.2 alleles per SSR primer. According to the results of genetic variability assessment the number and percentage of polymorphic loci was the maximal in pollinators NS1 and tester cms2 while effective number of alleles, expected heterozygosis and Shannon’s index was highest in pollinator EL0204. Analysis of molecular variance (AMOVA) showed that 77.34% of the total genetic variation was attributed to intra-varietal variance. Correspondence analysis results were very similar to grouping by neighbor-joining algorithm. Number of groups was smaller by one, because correspondence analysis merged IFVCNS pollinators with CZ25 into one group. Pollinators FC220, FC221 and C 51 were in the next group, while self-fertile pollinators CR10 and C930-35 from USDA-Salinas were separated. On another branch were self-sterile pollinators ЕL0204 and ЕL53 from USDA-East Lansing. Sterile testers cms1 and cms2 formed separate group. The presented results confirmed that SSR analysis can be successfully used in estimation of genetic diversity within and among sugar beet populations. Since the tested pollinator differed considering the presence of self-fertility gene, their heterozygosity differed as well. It was lower in genotypes with fixed self-fertility genes. Since the most of tested populations were open-pollinated, which rarely self-pollinate, high variability within the populations was expected. Cluster analysis grouped populations according to their origin.

Keywords: auto fertility, genetic diversity, pollinator, SSR, sugar beet

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Authors: Aiman Zehra, Sajad Mohd Wani

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Packaging has a vital role as it contains and protects the food that moves from the supply chain to the consumer. Chitosan (CH) has been extensively used in food packaging applications among the plentiful natural macromolecules, including all the polysaccharide class, owing to its easy film-forming capacity, biodegradability, better oxygen and water vapour barrier ability and good mechanical strength. Compared to synthetic films, the films produced from chitosan present poor barrier and mechanical properties. To overcome its deficient qualities, a number of modification procedures are required to enhance the mechanical and physical properties. Various additives such as plasticizers (e.g., glycerol and sorbitol), crosslinkers (e.g.,CaCl₂, ZnO), fillers (nanoclay), and antimicrobial agents (e.g. thyme essential oil) have been used to improve the mechanical, thermal, morphological, antimicrobial properties and emulsifying agents for the stability and elasticity of chitosan-based biodegradable films. Different novel biocomposite films based on chitosan incorporated with thyme essential oil and different additives (ZnO, CaCl₂, NC, and PEG) were successfully prepared and used as packaging material for carrot candy. The chitosan film incorporated with crosslinkers was capable of forming a protective barrier on the surface of the candy to maintain moisture content, water activity, TSS, total sugars, and titratable acidity. ZnO +PEG +NC +CaCl₂ remarkably promotes a synergistic effect on the barrier properties of the film. The combined use of ZnO +PEG +NC +CaCl₂ in CH-TO films was more effective in preventing the moisture gain in candies. The lowest a𝓌 (0.624) was also observed for the candies stored in treatment. The color values L*, a*, b* of the candies were also retained in the film containing all the additives during the 6th month of storage. The value for L*, a*, and b* observed for T was 42.72, 9.89, and 10.84, respectively. The candies packaged in film retained TSS and acidity. The packaging film significantly p≤0.05 conserved sensory qualities and inhibited microbial activity during storage. Carrot candy was found microbiologically safe for human consumption even after six months of storage in all the packaging materials.

Keywords: chitosan, biodegradable films, antimicrobial activity, thyme essential oil, crosslinkers

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Authors: Mehrdad Shafiei Dizaji, Hoda Azari

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The research explores the pioneering integration of Physics-Informed Neural Networks (PINNs) into the domain of Ground-Penetrating Radar (GPR) data prediction, akin to advancements in medical imaging for tracking tumor progression in the human body. This research presents a detailed development framework for a specialized PINN model proficient at interpreting and forecasting GPR data, much like how medical imaging models predict tumor behavior. By harnessing the synergy between deep learning algorithms and the physical laws governing subsurface structures—or, in medical terms, human tissues—the model effectively embeds the physics of electromagnetic wave propagation into its architecture. This ensures that predictions not only align with fundamental physical principles but also mirror the precision needed in medical diagnostics for detecting and monitoring tumors. The suggested deep learning structure comprises three components: a CNN, a spatial feature channel attention (SFCA) mechanism, and ConvLSTM, along with temporal feature frame attention (TFFA) modules. The attention mechanism computes channel attention and temporal attention weights using self-adaptation, thereby fine-tuning the visual and temporal feature responses to extract the most pertinent and significant visual and temporal features. By integrating physics directly into the neural network, our model has shown enhanced accuracy in forecasting GPR data. This improvement is vital for conducting effective assessments of bridge deck conditions and other evaluations related to civil infrastructure. The use of Physics-Informed Neural Networks (PINNs) has demonstrated the potential to transform the field of Non-Destructive Evaluation (NDE) by enhancing the precision of infrastructure deterioration predictions. Moreover, it offers a deeper insight into the fundamental mechanisms of deterioration, viewed through the prism of physics-based models.

Keywords: physics-informed neural networks, deep learning, ground-penetrating radar (GPR), NDE, ConvLSTM, physics, data driven

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Authors: Ali Heyder Alatas, D. Xin, L. Nai Ming

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An oil spill emergency can vary in size and complexity, subject to factors such as volume and characteristics of spilled oil, incident location, impacted sensitivities and resources required. A major incident typically involves numerous stakeholders; these include the responsible party, response organisations, government authorities across multiple jurisdictions, local communities, and a spectrum of technical experts. An incident management team will encounter numerous challenges. Factors such as limited access to location, adverse weather, poor communication, and lack of pre-identified resources can impede a response; delays caused by an inefficient response can exacerbate impacts caused to the wider environment, socio-economic and cultural resources. It is essential that all parties work based on defined roles, responsibilities and authority, and ensure the availability of sufficient resources. To promote steadfast coordination and overcome the challenges highlighted, an Incident Management System (IMS) offers an essential tool for oil spill response. It provides clarity in command and control, improves communication and coordination, facilitates the cooperation between stakeholders, and integrates resources committed. Following the preceding discussion, a comprehensive review of existing literature serves to illustrate the application of IMS in oil spill response to overcome common challenges faced in a major-scaled incident. With a primary audience comprising practitioners in mind, this study will discuss key principles of incident management which enables an effective response, along with pitfalls and challenges, particularly, the tension between government and industry; case studies will be used to frame learning and issues consolidated from previous research, and provide the context to link practice with theory. It will also feature the industry approach to incident management which was further crystallized as part of a review by the Joint Industry Project (JIP) established in the wake of the Macondo well control incident. The authors posit that a common IMS which can be adopted across the industry not only enhances response capacity towards a major oil spill incident but is essential to the global preparedness effort.

Keywords: command and control, incident management system, oil spill response, response organisation

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Authors: Fateme Montazeri

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Literary approaches towards the text of the Quran predate the modern period. Suyuti (d.1505)’s encyclopedia of Quranic sciences, Al-Itqan, provides a notable example. In the modern era, the study of the Quranic rhetorics received particular attention in the second half of the twentieth century by Egyptian scholars. Amin Al-Khouli (d. 1966), who might be considered the first to argue for the necessity of applying a literary-rhetorical lens toward the tafseer, Islamic exegesis, and his students championed the literary analysis as the most effective approach to the comprehension of the holy text. Western scholars continued the literary criticism of the Islamic scripture by applying to the Quran similar methodologies used in biblical studies. In the history of the literary examination of the Quran, the scope of the critical methods applied to the Quranic text has been limited. For, the rhetorical approaches to the Quran, in the premodern as well as the modern period, concerned almost exclusively with the lexical layer of the text, leaving the narratological dimensions insufficiently examined. Recent contributions, by Leyla Ozgur Alhassen, for instance, attempt to fill this lacunae. This paper aims at advancing the studies of the Quranic narratives by investigating the application of a literary device whose role in the Quranic stories remains unstudied, that is, “foreshadowing.” This paper shall focus on Chapter 12, “Surah al-Yusuf,” as its case study. Chapter 12, the single chapter that includes the story of Joseph in one piece, contains several instances in which the events of the story are foreshadowed. As shall be discussed, foreshadowing occurs either through a monolog or dialogue whereby one or more of the characters allude to the future happenings or through the manner in which the setting is described. Through a close reading of the text, it will be demonstrated that the usage of the rhetorical tool of foreshadowing meets a dual purpose: on the one hand, foreshadowing prepares the reader/audience for the upcoming events in the plot, and on the other hand, it highlights the psychological dimensions of the characters, their thoughts, intentions, and disposition. In analyzing the story, this study shall draw on psychoanalytical criticism to explore the layers of meanings embedded in the Quranic narrative that are unfolded through foreshadowing.

Keywords: foreshadowing, quranic narrative, literary criticism, surah yusuf

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Authors: Zakir Hossain, Arzu Pervin, Halima Jahan, Rabeya Akter, Abdel Omri

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Replacement of fish meal with soybean meal is an effective way to relieve the pressure on fish meal as the supply of this feed ingredient is dwindling and certainly is not sustainable in long term at present levels in commercial feeds. This study was designed to determine the effect of fishmeal (FM) replacement with soybean meal (SBM) in diet on growth, digestive enzyme activity, antioxidation and gut histomorphology of tilapia (Oreochromis niloticus). Five diets were formulated where SBM0 contained 100% FM, FM substituted with graded levels of a mix of SBM to replace 25% (SBM25), 50% (SBM50), 75% (SBM75) and 100% (SBM100) of FM. Juvenile tilapia having weight and length of 6.60±0.13 g and 5.42±0.17 cm were randomly divided into five treatment groups having 40 individual each group and fed to visual satiation for 90 days. Diet with SBM was increased significant in body weight gain and specific growth rate in fish compared to the fish fed with SBM100. Fish having the similar weight (74.34±5.41 g) fed the diets SBM50, SBM75 and SBM100 containing higher level of SBM showed significantly longer intestine compared to SBM0. Villus height of stomach and intestine were significantly greater in the fish fed with the diets SBM0, SBM25 and SBM50 compared to SBM100. Muscular thickness was inversely changed with the increasing villus height. Protease activity was increased significantly in stomach, anterior and posterior intestine of fish fed with SBM0 and SBM25 compared to SBM100. In anterior and posterior segment of intestine, significantly higher lipase activity was observed in fish fed with the diets SBM0 and SBM25 compared to diet SBM100. In stomach, amylase activity was also significantly greater in SBM0 compared to SBM100. The antioxidant enzymes including catalase and superoxide dismutase of liver were significantly (P < 0.05) higher in the O. niloticus fed SBM100 compared to the ones fed SBM0. These results suggest that the replacement of FM upto 75% with SBM could be possible considering the growth performances, gut health and activities digestive enzymes and antioxidant enzymes in O. niloticus.

Keywords: soybean meal, fish meal, digestive enzymes, anti-oxidant enzymes

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Authors: Muhammad Tanveer Altaf, Mehmet Bedir, Waqas Liaqat, Gönül Cömertpay, Volkan Çatalkaya, Celaluddin Barutçular, Nergiz Çoban, Ibrahim Cerit, Muhammad Azhar Nadeem, Tolga Karaköy, Faheem Shehzad Baloch

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Food production needs to be almost double by 2050 in order to feed around 9 billion people around the Globe. Plant production mostly relies on fertilizers, which also have one of the main roles in environmental pollution. In addition to this, climatic conditions are unpredictable, and the earth is expected to face severe drought conditions in the future. Therefore, water and fertilizers, especially nitrogen are considered as main constraints for future food security. To face these challenges, developing integrative approaches for germplasm characterization and selecting the resilient genotypes performing under limiting conditions is very crucial for effective breeding to meet the food requirement under climatic change scenarios. This study is part of the European Research Area Network (ERANET) project for the characterization of the diversity panel of 172 sorghum accessions and six hybrids as control cultivars under limiting (+N/-H2O, -N/+H2O) and non-limiting conditions (+N+H2O). This study was planned to characterize the sorghum diversity in relation to resource Use Efficiency (RUE), with special attention on harnessing the interaction between genotype and environment (GxE) from a physiological and agronomic perspective. Experiments were conducted at Adana, a Mediterranean climate, with augmented design, and data on various agronomic and physiological parameters were recorded. Plentiful diversity was observed in the sorghum diversity panel and significant variations were seen among the limiting water and nitrogen conditions in comparison with the control experiment. Potential genotypes with the best performance are identified under limiting conditions. Whole genome resequencing was performed for whole germplasm under investigation for diversity analysis. GWAS analysis will be performed using genotypic and phenotypic data and linked markers will be identified. The results of this study will show the adaptation and improvement of sorghum under climate change conditions for future food security.

Keywords: germplasm, sorghum, drought, nitrogen, resources use efficiency, sequencing

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Authors: Fatemeh Jannesarvatan, Ghazaal Parastooei, Jimmy frerejan, Saedeh Mokhtari, Peter Van Rosmalen

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Medical and dental education increasingly emphasizes the acquisition, integration, and coordination of complex knowledge, skills, and attitudes that can be applied in practical situations. Instructional design approaches have focused on using real-life tasks in order to facilitate complex learning in both real and simulated environments. The Four component instructional design (4C/ID) model has become a useful guideline for designing instructional materials that improve learning transfer, especially in health profession education. The objective of this study was to apply the 4C/ID model in the creation of virtual patients (VPs) that dental students can use to practice their clinical management and clinical reasoning skills. The study first explored the context and concept of complication factors and common errors for novices and how they can affect the design of a virtual patient program. The study then selected key dental information and considered the content needs of dental students. The design of virtual patients was based on the 4C/ID model's fundamental principles, which included: Designing learning tasks that reflect real patient scenarios and applying different levels of task complexity to challenge students to apply their knowledge and skills in different contexts. Creating varied learning materials that support students during the VP program and are closely integrated with the learning tasks and students' curricula. Cognitive feedback was provided at different levels of the program. Providing procedural information where students followed a step-by-step process from history taking to writing a comprehensive treatment plan. Four virtual patients were designed using the 4C/ID model's principles, and an experimental design was used to test the effectiveness of the principles in achieving the intended educational outcomes. The 4C/ID model provides an effective framework for designing engaging and successful virtual patients that support the transfer of knowledge and skills for dental students. However, there are some challenges and pitfalls that instructional designers should take into account when developing these educational tools.

Keywords: 4C/ID model, virtual patients, education, dental, instructional design

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Authors: Recep Kesli, Gulşah Asik, Cengiz Demir, Onur Turkyilmaz

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Objective: Acinetobacter baumannii (A. baumannii) can cause health-care associated infections, such as bacteremia, urinary tract and wound infections, endocarditis, meningitis, and pneumonia, particularly in intensive care unit patients. In this study, we aimed to evaluate A. baumannii production in sputum and bronchoalveolar lavage and susceptibilities for antibiotics in a 24 months period. Methods: Between October 2013 and September 2015, Acinetobacter baumannii isolated from respiratory tract speciments were evaluated retrospectively. The strains were isolated from the different intensive care units patients. A. baumannii strains were identified by both the conventional methods and aoutomated identification system -VITEK 2 (bio-Merieux, Marcy l’etoile, France). Antibiotic resistance testing was performed by Kirby-Bauer disc diffusion method according to CLSI criteria. Results: All the ninety isolates included in the study were from respiratory tract specimens. While of all the isolated 90 Acinetobacter baumannii strains were found to be resistant (100%), against ceftriaxone, ceftazidime, ciprofloxacin and piperacillin/ tazobactam, resistance rates against other tested antibiotics found as follows; meropenem 77, 86%, imipenem 75, 83%, trimethoprim-sulfamethoxazole (TMP-STX) 69, 76,6%, gentamicin 51, 56,6% and amikacin 48, 53,3%. Colistin was found as the most effective antibiotic against Acinetobacter baumannii, and there were not found any resistant (0%) strain against colistin. Conclusion: This study demonstrated that the no resistance was found in Acinetobacter baumannii against to colistin. High rates of resistance to carbapenems (imipenem and meropenem) and other tested antibiotics (ceftiaxone, ceftazidime, ciprofloxacine, piperacilline-tazobactam, TMP-STX gentamicin and amikacin) also have remarkable resistance rates. There was a significant relationship between demographic features of patients such as age, undergoing mechanical ventilation, length of hospital stay with resistance rates. High resistance rates against antibiotics require implementation of the infection control program and rational use of antibiotics. In the present study, while there were not found colistin resistance, panresistance were found against to ceftriaxone, ceftazidime, ciprofloxacin and piperacillin/ tazobactam.

Keywords: acinetobacter baumannii, antibiotic resistance, multi drug resistance, intensive care unit

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Authors: Sachil Kumar, Anoop K.Verma, Uma Shankar Singh

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It’s extremely important to study postmortem interval in different causes of death since it assists in a great way in making an opinion on the exact cause of death following such incident often times. With diligent knowledge of the interval one could really say as an expert that the cause of death is not feigned hence there is a great need in evaluating such death to have been at the CRIME SCENE before performing an autopsy on such body. The approach described here is based on analyzing the degradation or proteolysis of a cardiac protein in cases of deaths due to burn as a marker of time since death. Cardiac tissue samples were collected from (n=6) medico-legal autopsies, (Department of Forensic Medicine and Toxicology), King George’s Medical University, Lucknow India, after informed consent from the relatives and studied post-mortem degradation by incubation of the cardiac tissue at room temperature (20±2 OC) for different time periods (~7.30, 18.20, 30.30, 41.20, 41.40, 54.30, 65.20, and 88.40 Hours). The cases included were the subjects of burn without any prior history of disease who died in the hospital and their exact time of death was known. The analysis involved extraction of the protein, separation by denaturing gel electrophoresis (SDS-PAGE) and visualization by Western blot using cTnT specific monoclonal antibodies. The area of the bands within a lane was quantified by scanning and digitizing the image using Gel Doc. As time postmortem progresses the intact cTnT band degrades to fragments that are easily detected by the monoclonal antibodies. A decreasing trend in the level of cTnT (% of intact) was found as the PM hours increased. A significant difference was observed between <15 h and other PM hours (p<0.01). Significant difference in cTnT level (% of intact) was also observed between 16-25 h and 56-65 h & >75 h (p<0.01). Western blot data clearly showed the intact protein at 42 kDa, three major (28 kDa, 30kDa, 10kDa) fragments, three additional minor fragments (12 kDa, 14kDa, and 15 kDa) and formation of low molecular weight fragments. Overall, both PMI and cardiac tissue of burned corpse had a statistically significant effect where the greatest amount of protein breakdown was observed within the first 41.40 Hrs and after it intact protein slowly disappears. If the percent intact cTnT is calculated from the total area integrated within a Western blot lane, then the percent intact cTnT shows a pseudo-first order relationship when plotted against the time postmortem. A strong significant positive correlation was found between cTnT and PM hours (r=0.87, p=0.0001). The regression analysis showed a good variability explained (R2=0.768) The post-mortem Troponin-T fragmentation observed in this study reveals a sequential, time-dependent process with the potential for use as a predictor of PMI in cases of burning.

Keywords: burn, degradation, postmortem interval, troponin-T

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Authors: Callistus I. Iheme, Kenneth E. Asika, Emmanuel I. Ugwor, Chukwuka U. Ogbonna, Ugonna H. Uzoka, Nneamaka A. Chiegboka, Chinwe S. Alisi, Obinna S. Nwabueze, Amanda U. Ezirim, Judeanthony N. Ogbulie

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Antimicrobial resistance (AMR) is a major threat to the global health sector. Zinc oxide nanocomposites (ZnONCs), composed of zinc oxide nanoparticles and phytochemicals from Azadirachta indica aqueous leaf extract, were assessed for their physico-chemicals, in silico and in vitro antimicrobial properties on multidrug-resistant Escherichia coli enzymes. Gas chromatography coupled with mass spectroscope (GC-MS) analysis on the ZnONCs revealed the presence of twenty volatile phytochemical compounds, among which is scoparone. Characterization of the ZnONCs was done using ultraviolet-visible spectroscopy (UV-vis), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and x-ray diffractometer (XRD). Dehydrogenase enzyme converts colorless 2,3,5-triphenyltetrazolium chloride to the red triphenyl formazan (TPF). The rate of formazan formation in the presence of ZnONCs is proportional to the enzyme activities. The color formation is extracted and determined at 500 nm, and the percentage of enzyme activity is calculated. To determine the bioactive components of the ZnONCs, characterize their binding to enzymes, and evaluate the enzyme-ligand complex stability, respectively Discrete Fourier Transform (DFT) analysis, docking, and molecular dynamics simulations will be employed. The results showed arrays of ZnONCs nanorods with maximal absorption wavelengths of 320 nm and 350 nm and thermally stable at the temperature range of 423.77 to 889.69 ℃. In vitro study assessed the dehydrogenase inhibitory properties of the ZnONCs, conjugate of ZnONCs and ampicillin (ZnONCs-amp), the aqueous leaf extract of A. indica, and ampicillin (standard drug). The findings revealed that at the concentration of 500 μm/mL, 57.89 % of the enzyme activities were inhibited by ZnONCs compared to 33.33% and 21.05% of the standard drug (Ampicillin), and the aqueous leaf extract of the A. indica respectively. The inhibition of the enzyme activities by the ZnONCs at 500 μm/mL was further enhanced to 89.74 % by conjugating with Ampicillin. In silico study on the ZnONCs revealed scoparone as the most viable competitor of nicotinamide adenine dinucleotide (NAD⁺) for the coenzyme binding pocket on E. coli malate and histidinol dehydrogenase. From the findings, it can be concluded that the scoparone components of the nanocomposites in synergy with the zinc oxide nanoparticles inhibited E. coli malate and histidinol dehydrogenase by competitively binding to the NAD⁺ pocket and that the conjugation of the ZnONCs with ampicillin further enhanced the antimicrobial efficiency of the nanocomposite against multidrug resistant E. coli.

Keywords: antimicrobial resistance, dehydrogenase activities, E. coli, zinc oxide nanocomposites

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Authors: Alejandra Torres-Landa López

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Introduction: Can architecture students be creative in spaces conformed by an educational infrastructure build with paradigms of the past?, this question and others related are answered in this paper as it presents the PhD research: An anthropic conflict in Mexican Higher Education Institutes, problems and challenges of the educational infrastructure in teaching and learning History of Architecture. This research was finished in 2013 and is one of the first studies conducted nationwide in Mexico that analysis the educational infrastructure impact in learning architecture; its objective was to identify which elements of the educational infrastructure of Mexican Higher Education Institutes where architects are formed, hinder or contribute to the teaching and learning of History of Architecture; how and why it happens. The methodology: A mixed methodology was used combining quantitative and qualitative analysis. Different resources and strategies for data collection were used, such as questionnaires for students and teachers, interviews to architecture research experts, direct observations in Architecture classes, among others; the data collected was analyses using SPSS and MAXQDA. The veracity of the quantitative data was supported by the Cronbach’s Alpha Coefficient, obtaining a 0.86, figure that gives the data enough support. All the above enabled to certify the anthropic conflict in which Mexican Universities are. Major findings of the study: Although some of findings were probably not unknown, they haven’t been systematized and analyzed with the depth to which it’s done in this research. So, it can be said, that the educational infrastructure of most of the Higher Education Institutes studied, is a barrier to the educational process, some of the reasons are: the little morphological variation of space, the inadequate control of lighting, noise, temperature, equipment and furniture, the poor or none accessibility for disable people; as well as the absence, obsolescence and / or insufficiency of information technologies are some of the issues that generate an anthropic conflict understanding it as the trouble that teachers and students have to relate between them, in order to achieve significant learning). It is clear that most of the educational infrastructure of Mexican Higher Education Institutes is anchored to paradigms of the past; it seems that they respond to the previous era of industrialization. The results confirm that the educational infrastructure of Mexican Higher Education Institutes where architects are formed, is perceived as a "closed container" of people and data; infrastructure that becomes a barrier to teaching and learning process. Conclusion: The research results show it's time to change the paradigm in which we conceive the educational infrastructure, it’s time to stop seen it just only as classrooms, workshops, laboratories and libraries, as it must be seen from a constructive, urban, architectural and human point of view, taking into account their different dimensions: physical, technological, documental, social, among others; so the educational infrastructure can become a set of elements that organize and create spaces where ideas and thoughts can be shared; to be a social catalyst where people can interact between each other and with the space itself.

Keywords: educational infrastructure, impact of space in learning architecture outcomes, learning environments, teaching architecture, learning architecture

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Authors: Keshav Dubey, Swajeeth Panchangam, Arun Rajendran, Swarnim Gupta

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In the semiconductor capital equipment industry, effective modeling of repairable system reliability is crucial for optimizing maintenance strategies and ensuring operational efficiency. However, repairable system reliability modeling using a renewal process is not as popular in the semiconductor equipment industry as it is in the locomotive and automotive industries. Utilization of this approach will help optimize maintenance practices. This paper presents a structured framework that leverages both parametric and non-parametric approaches to model the reliability of repairable subsystems based on operational data, maintenance schedules, and system-specific conditions. Data is organized at the equipment ID level, facilitating trend testing to uncover failure patterns and system degradation over time. For non-parametric modeling, the Mean Cumulative Function (Mean Cumulative Function) approach is applied, offering a flexible method to estimate the cumulative number of failures over time without assuming an underlying statistical distribution. This allows for empirical insights into subsystem failure behavior based on historical data. On the parametric side, virtual age modeling, along with Homogeneous and Non-Homogeneous Poisson Process (Homogeneous Poisson Process and Non-Homogeneous Poisson Process) models, is employed to quantify the effect of repairs and the aging process on subsystem reliability. These models allow for a more structured analysis by characterizing repair effectiveness and system wear-out trends over time. A comparison of various Generalized Renewal Process (GRP) approaches highlights their utility in modeling different repair effectiveness scenarios. These approaches provide a robust framework for assessing the impact of maintenance actions on system performance and reliability. By integrating both parametric and non-parametric methods, this framework offers a comprehensive toolset for reliability engineers to better understand equipment behavior, assess the effectiveness of maintenance activities, and make data-driven decisions that enhance system availability and operational performance in semiconductor fabrication facilities.

Keywords: reliability, maintainability, homegenous poission process, repairable system

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Authors: Mahtab Makaremi Masouleh, Günter Wozniak

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This research is part of an interdisciplinary project, promoting the design of a light temporary installable textile defence system against flood. In case river water levels increase abruptly especially in winter time, one can expect massive extra load on a textile protective structure in term of impact as a result of floating debris and even tree trunks. Estimation of this impulsive force on such structures is of a great importance, as it can ensure the reliability of the design in critical cases. This fact provides the motivation for the numerical analysis of a fluid structure interaction application, comprising flexible slender shaped and free-surface water flow, where an accelerated heavy flotsam tends to approach the membrane. In this context, the analysis on both the behavior of the flexible membrane and its interaction with moving flotsam is conducted by finite elements based solvers of the explicit solver and implicit Abacus solver available as products of SIMULIA software. On the other hand, a study on how free surface water flow behaves in response to moving structures, has been investigated using the finite volume solver of Star CCM+ from Siemens PLM Software. An automatic communication tool (CSE, SIMULIA Co-Simulation Engine) and the implementation of an effective partitioned strategy in form of an implicit coupling algorithm makes it possible for partitioned domains to be interconnected powerfully. The applied procedure ensures stability and convergence in the solution of these complicated issues, albeit with high computational cost; however, the other complexity of this study stems from mesh criterion in the fluid domain, where the two structures approach each other. This contribution presents the approaches for the establishment of a convergent numerical solution and compares the results with experimental findings.

Keywords: co-simulation, flexible thin structure, fluid-structure interaction, implicit coupling algorithm, moving flotsam

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Authors: Grace O. Akinlade, Danjuma D. Maza, Oluwakemi O. Olawolu, Delight O. Babalola, John A. O. Oyekunle, Joshua O. Ojo

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The Mokuro area of Ile-Ife, South West Nigeria, was well known for gold mining in the past (about twenty years ago). However, the place has since been reclaimed and converted to residential area without any environmental risk assessment of the impact of the mining tailings on the environment. Soil, water, and plant samples were collected from 4 different locations around the mine-turned-residential area. Soil samples were pulverized and sieved into finer particles, while the plant samples were dried and pulverized. All the samples were digested and analyzed for As, Pb, Cd, and Zn using atomic absorption spectroscopy (AAS). From the analysis results, the hazard index (HI) was then calculated for the metals. The soil and plant samples were air dried and pulverized, then weighed, after which the samples were packed into special and properly sealed containers to prevent radon gas leakage. After the sealing, the samples were kept for 28 days to attain secular equilibrium. The concentrations of 40K, 238U, and 232Th in the samples were measured using a cesium iodide (CsI) spectrometer and URSA software. The AAS analysis showed that As, Pb, Cd (Toxic metals), and Zn (essential trace metals) are in concentrations lower than permissible limits in plants and soil samples, while the water samples had concentrations higher than permissible limits. The calculated health indices (HI) show that HI for water is >1 and that of plants and soil is <1. Gamma spectrometry result shows high levels of activity concentrations above the recommended limits for all the soil and plant samples collected from the area. Only the water samples have activity concentrations below the recommended limit. Consequently, the absorbed dose, annual effective dose, and excess lifetime cancer risk are all above the recommended safe limit for all the samples except for water samples. In conclusion, all the samples collected from the area are either contaminated with toxic metals or they pose radiological hazards to the consumers. Further detailed study is therefore recommended in order to be able to advise the residents appropriately.

Keywords: toxic metals, gamma spectrometry, Ile-Ife, radiological hazards, gold mining

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Authors: Atchara Sankom, Warapa Mahakarnchanakul, Ronnarit Rittiron, Tanaboon Sajjaanantakul, Thammasak Thongket

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Vegetables are frequently contaminated with pesticides residues resulting in the most food safety concern among agricultural products. The objective of this work was to develop a method to detect the organophosphate (OP) pesticides residues in vegetables using Near Infrared (NIR) spectroscopy technique. Low concentration (ppm) of OP pesticides in vegetables were investigated. The experiment was divided into 2 sections. In the first section, Chinese kale spiked with different concentrations of chlorpyrifos pesticide residues (0.5-100 ppm) was chosen as the sample model to demonstrate the appropriate conditions of sample preparation, both for a solution or solid sample. The spiked samples were extracted with acetone. The sample extracts were applied as solution samples, while the solid samples were prepared by the dry-extract system for infrared (DESIR) technique. The DESIR technique was performed by embedding the solution sample on filter paper (GF/A) and then drying. The NIR spectra were measured with the transflectance mode over wavenumber regions of 12,500-4000 cm⁻¹. The QuEChERS method followed by gas chromatography-mass spectrometry (GC-MS) was performed as the standard method. The results from the first section showed that the DESIR technique with NIR spectroscopy demonstrated good accurate calibration result with R² of 0.93 and RMSEP of 8.23 ppm. However, in the case of solution samples, the prediction regarding the NIR-PLSR (partial least squares regression) equation showed poor performance (R² = 0.16 and RMSEP = 23.70 ppm). In the second section, the DESIR technique coupled with NIR spectroscopy was applied to the detection of OP pesticides in vegetables. Vegetables (Chinese kale, cabbage and hot chili) were spiked with OP pesticides (chlorpyrifos ethion and profenofos) at different concentrations ranging from 0.5 to 100 ppm. Solid samples were prepared (based on the DESIR technique), then samples were scanned by NIR spectrophotometer at ambient temperature (25+2°C). The NIR spectra were measured as in the first section. The NIR- PLSR showed the best calibration equation for detecting low concentrations of chlorpyrifos residues in vegetables (Chinese kale, cabbage and hot chili) according to the prediction set of R2 and RMSEP of 0.85-0.93 and 8.23-11.20 ppm, respectively. For ethion residues, the best calibration equation of NIR-PLSR showed good indexes of R² and RMSEP of 0.88-0.94 and 7.68-11.20 ppm, respectively. As well as the results for profenofos pesticide, the NIR-PLSR also showed the best calibration equation for detecting the profenofos residues in vegetables according to the good index of R² and RMSEP of 0.88-0.97 and 5.25-11.00 ppm, respectively. Moreover, the calibration equation developed in this work could rapidly predict the concentrations of OP pesticides residues (0.5-100 ppm) in vegetables, and there was no significant difference between NIR-predicted values and actual values (data from GC-MS) at a confidence interval of 95%. In this work, the proposed method using NIR spectroscopy involving the DESIR technique has proved to be an efficient method for the screening detection of OP pesticides residues at low concentrations, and thus increases the food safety potential of vegetables for domestic and export markets.

Keywords: NIR spectroscopy, organophosphate pesticide, vegetable, food safety

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Authors: Adonis Menezes, J. C. Passos

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The current panorama of technology in heat transfer and the scarcity of information about the convective boiling of CO₂ and hydrocarbon in small diameter channels motivated the development of this work. Among non-halogenated refrigerants, CO₂/ R744 has distinct thermodynamic properties compared to other fluids. The R744 presents significant differences in operating pressures and temperatures, operating at higher values compared to other refrigerants, and this represents a challenge for the design of new evaporators, as the original systems must normally be resized to meet the specific characteristics of the R744, which creates the need for a new design and optimization criteria. To carry out the convective boiling tests of CO₂, an experimental apparatus capable of storing (m= 10kg) of saturated CO₂ at (T = -30 ° C) in an accumulator tank was used, later this fluid was pumped using a positive displacement pump with three pistons, and the outlet pressure was controlled and could reach up to (P = 110bar). This high-pressure saturated fluid passed through a Coriolis type flow meter, and the mass velocities varied between (G = 20 kg/m².s) up to (G = 1000 kg/m².s). After that, the fluid was sent to the first test section of circular cross-section in diameter (D = 4.57mm), where the inlet and outlet temperatures and pressures, were controlled and the heating was promoted by the Joule effect using a source of direct current with a maximum heat flow of (q = 100 kW/m²). The second test section used a cross-section with multi-channels (seven parallel channels) with a square cross-section of (D = 2mm) each; this second test section has also control of temperature and pressure at the inlet and outlet as well as for heating a direct current source was used, with a maximum heat flow of (q = 20 kW/m²). The fluid in a biphasic situation was directed to a parallel plate heat exchanger so that it returns to the liquid state, thus being able to return to the accumulator tank, continuing the cycle. The multi-channel test section has a viewing section; a high-speed CMOS camera was used for image acquisition, where it was possible to view the flow patterns. The experiments carried out and presented in this report were conducted in a rigorous manner, enabling the development of a database on the convective boiling of the R744 in macro and micro channels. The analysis prioritized the processes from the beginning of the convective boiling until the drying of the wall in a subcritical regime. The R744 resurfaces as an excellent alternative to chlorofluorocarbon refrigerants due to its negligible ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) rates, among other advantages. The results found in the experimental tests were very promising for the use of CO₂ in micro-channels in convective boiling and served as a basis for determining the flow pattern map and correlation for determining the heat transfer coefficient in the convective boiling of CO₂.

Keywords: convective boiling, CO₂/R744, macro-channels, micro-channels

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Authors: D. Scarpanti, M. Brondino, M. Pasini

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Background: the present study explores the role of light and restorativeness on work. According with the Attention Restoration Theory (ART) and a Model of Work Environment, the main idea is that some features of environment, i.e., lighting, influences the direct attention, and so, the performance. Restorativeness refers to the presence/absence level of all the characteristics of physical environment that help to regenerate direct attention. Specifically, lighting can affect level of fascination and attention in one hand; and in other hand promotes several biological functions via pineal gland. Different reviews on this topic show controversial results. In order to bring light on this topic, the hypotheses of this study are that lighting can affect the construct of restorativeness and, in the second time, the restorativeness can affect the performance. Method: the participants are 30 workers of a mechatronic company in the North Italy. Every subject answered to a questionnaire valuing their subjective perceptions of environment in a different way: some objective features of environment, like lighting, temperature and air quality; some subjective perceptions of this environment; finally, the participants answered about their perceived performance. The main attention is on the features of light and his components: visual comfort, general preferences and pleasantness; and the dimensions of the construct of restorativeness; fascination, coherence and being away. The construct of performance per se is conceptualized in three level: individual, team membership and organizational membership; and in three different components: proficiency, adaptability, and proactivity, for a total of 9 subcomponents. Findings: path analysis showed that some characteristics of lighting respectively affected the dimension of fascination; and, as expected, the dimension of fascination affected work performance. Conclusions: The present study is a first pilot step of a wide research. These first results can be summarized with the statement that lighting and restorativeness contribute to explain work performance variability: in details perceptions of visual comfort, satisfaction and pleasantness, and fascination respectively. Results related to fascination are particularly interesting because fascination is conceptualized as the opposite of the construct of direct attention. The main idea is, in order to regenerate attentional capacity, it’s necessary to provide a lacking of attention (fascination). The sample size did not permit to test simultaneously the role of the perceived characteristics of light to see how they differently contribute to predict fascination of the work environment. However, the results highlighted the important role that light could have in predicting restorativeness dimensions and probably with a larger sample we could find larger effects also on work performance. Furthermore, longitudinal data will contribute to better analyze the causal model along time. Applicative implications: the present pilot study highlights the relevant role of lighting and perceived restorativeness in the work environment and the importance to focus attention on light features and the restorative characteristics in the design of work environments.

Keywords: lighting, performance, restorativeness, workplace

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Authors: Safak Isik, Ozalp Vayvay

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Strategic partnerships with suppliers play a vital role for the long-term value-based supply chain. This strategic collaboration keeps still being one of the top priority of many business organizations in order to create more additional value; benefiting mainly from supplier’s specialization, capacity and innovative power, securing supply and better managing costs and quality. However, many organizations encounter difficulties in initiating, developing and managing those partnerships and many attempts result in failures. One of the reasons for such failure is the incompatibility of members of this partnership or in other words wrong supplier selection which emphasize the significance of the selection process since it is the beginning stage. An effective selection process of strategic suppliers is critical to the success of the partnership. Although there are several research studies to select the suppliers in literature, only a few of them is related to strategic supplier selection for long-term partnership. The purpose of this study is to propose a conceptual model for the selection of strategic partnership suppliers. A two-stage approach has been used in proposed model incorporating first segmentation and second selection. In the first stage; considering the fact that not all suppliers are strategically equal and instead of a long list of potential suppliers, Kraljic’s purchasing portfolio matrix can be used for segmentation. This supplier segmentation is the process of categorizing suppliers based on a defined set of criteria in order to identify types of suppliers and determine potential suppliers for strategic partnership. In the second stage, from a pool of potential suppliers defined at first phase, a comprehensive evaluation and selection can be performed to finally define strategic suppliers considering various tangible and intangible criteria. Since a long-term relationship with strategic suppliers is anticipated, criteria should consider both current and future status of the supplier. Based on an extensive literature review; strategical, operational and organizational criteria have been determined and elaborated. The result of the selection can also be used to determine suppliers who are not ready for a partnership but to be developed for strategic partnership. Since the model is based on multiple criteria for both stages, it provides a framework for further utilization of Multi-Criteria Decision Making (MCDM) techniques. The model may also be applied to a wide range of industries and involve managerial features in business organizations.

Keywords: Kraljic’s matrix, purchasing portfolio, strategic supplier selection, supplier collaboration, supplier partnership, supplier segmentation

Procedia PDF Downloads 238

Authors: Sankha Chakrabortty, Biswajit Ruj, Parimal Pal

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Methanol is one of the most important chemical products and intermediates. It can be used as a solvent, intermediate or raw material for a number of higher valued products, fuels or additives. From the last one decay, the total global demand of methanol has increased drastically which forces the scientists to produce a large amount of methanol from a renewable source to meet the global demand with a sustainable way. Different types of non-renewable based raw materials have been used for the synthesis of methanol on a large scale which makes the process unsustainable. In this circumstances, photocatalytic conversion of CO₂ into methanol under solar/UV excitation becomes a viable approach to give a sustainable production approach which not only meets the environmental crisis by recycling CO₂ to fuels but also reduces CO₂ amount from the atmosphere. Development of such sustainable production approach for CO₂ conversion into methanol still remains a major challenge in the current research comparing with conventional energy expensive processes. In this backdrop, the development of environmentally friendly materials, like photocatalyst has taken a great perspective for methanol synthesis. Scientists in this field are always concerned about finding an improved photocatalyst to enhance the photocatalytic performance. Graphene-based hybrid and composite materials with improved properties could be a better nanomaterial for the selective conversion of CO₂ to methanol under visible light (solar energy) or UV light. The present invention relates to synthesis an improved heterogeneous graphene-based photocatalyst with improved catalytic activity and surface area. Graphene with enhanced surface area is used as coupled material of copper-loaded titanium oxide to improve the electron capture and transport properties which substantially increase the photoinduced charge transfer and extend the lifetime of photogenerated charge carriers. A fast reduction method through H₂ purging has been adopted to synthesis improved graphene whereas ultrasonication based sol-gel method has been applied for the preparation of graphene coupled copper loaded titanium oxide with some enhanced properties. Prepared photocatalysts were exhaustively characterized using different characterization techniques. Effects of catalyst dose, CO₂ flow rate, reaction temperature and stirring time on the efficacy of the system in terms of methanol yield and productivity have been studied in the present study. The study shown that the newly synthesized photocatalyst with an enhanced surface resulting in a sustained productivity and yield of methanol 0.14 g/Lh, and 0.04 g/gcat respectively, after 3 h of illumination under UV (250W) at an optimum catalyst dosage of 10 g/L having 1:2:3 (Graphene: TiO₂: Cu) weight ratio.

Keywords: renewable energy, CO₂ capture, photocatalytic conversion, methanol

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Authors: C. J. Rossouw, T. I. van Niekerk

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The global manufacturing industry is utilizing the internet and cloud-based services to further explore the anatomy and optimize manufacturing processes in support of the movement into the Fourth Industrial Revolution (4IR). The 4IR from a third world and African perspective is hindered by the fact that many manufacturing systems that were developed in the third industrial revolution are not inherently equipped to utilize the internet and services of the 4IR, hindering the progression of third world manufacturing industries into the 4IR. This research focuses on the development of a non-invasive and cost-effective cyber-physical IoT system that will exploit a machine’s vibration to expose semantic characteristics in the manufacturing process and utilize these results through a real-time cloud-based machine condition monitoring system with the intention to optimize the system. A microcontroller-based IoT sensor was designed to acquire a machine’s mechanical vibration data, process it in real-time, and transmit it to a cloud-based platform via Wi-Fi and the internet. Time-frequency Fourier analysis was applied to the vibration data to form an image representation of the machine’s behaviour. This data was used to train a Convolutional Neural Network (CNN) to learn semantic characteristics in the machine’s behaviour and relate them to a state of operation. The same data was also used to train a Convolutional Autoencoder (CAE) to detect anomalies in the data. Real-time edge-based artificial intelligence was achieved by deploying the CNN and CAE on the sensor to analyse the vibration. A cloud platform was deployed to visualize the vibration data and the results of the CNN and CAE in real-time. The cyber-physical IoT system was deployed on a semi-automated metal granulation machine with a set of trained machine learning models. Using a single sensor, the system was able to accurately visualize three states of the machine’s operation in real-time. The system was also able to detect a variance in the material being granulated. The research demonstrates how non-IoT manufacturing systems can be equipped with edge-based artificial intelligence to establish a remote machine condition monitoring system.

Keywords: IoT, cyber-physical systems, artificial intelligence, manufacturing, vibration analytics, continuous machine condition monitoring

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Authors: Xinli Chi, Xiaoqi Wei

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Background: Body-mind theory refers to the concept that the mind and body are interconnected; in this case, combining aerobic exercise and mindfulness-based training may be beneficial for mind-body health; however, there is limited evidence regarding their effects and potential mechanisms among Chinese university students. Therefore, the current study aims to examine the preliminary effects and feasibility of the combined intervention on depressive and insomnia symptoms, as well as to explore the underlying mechanisms. Methods: This is a two-arm pilot study of a randomized, controlled trial. Sixty-one Chinese university students were randomly allocated to 8-week combined intervention group (aerobic exercise plus mindfulness, N = 36) or control group (N = 36). In addition, 8 participants in combined intervention group were later volunteer to engage in semi-structured interview. The Self-Rating Depression Scale (SDS) and the Youth Self-Rating Insomnia Scales (YSIS) were used to measure depressive and insomnia symptoms, respectively. The intervention outcome and feasibility were tested by repeated-measures ANOVA, mediation model, and qualitative analysis. Results: The study included 31 participants in the intervention group and 30 participants in the control group, all of whom completed pre-test and post-test questionnaires. The results of the repeated-measures ANOVA showed that the combined intervention was effective in reducing depressive and insomnia symptoms among university students. Moreover, the mediation analysis suggested that improvement in insomnia symptoms might be a significant mechanism for the combined intervention. Qualitative analysis identified two main themes: “Helpful aspects of mind-body state” (including 7 sub-themes) and “Factors that influence the training effects” (including 3 sub-themes). Conclusions: The study confirmed the preliminary effect and feasibility of the combined intervention of mindfulness and aerobic exercise, while also exploring the potential mechanisms underlying this effect. Additionally, qualitative data provided valuable insights for optimizing future protocols.

Keywords: combined intervention, mindfulness, aerobic exercise, depressive symptoms, insomnia symptoms

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Authors: Jennifer Walinga, Samantha Heron

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The goal of the study was to inform the design of effective leadership and mentorship development programming for sport science leaders within the network of Canadian sport institutes and centers. The LEAD (Learn, Engage, Accelerate, Develop) program was implemented to equip sport science leaders with the leadership knowledge, skills, and practice to foster a high - performance culture, enhance the daily training environment, and contribute to optimal performance in sport. After two years of delivery, this analysis of LEAD’s effect on individual and organizational health and performance factors informs the quality of future deliveries and identifies best practice for leadership development across the Canadian sport system and beyond. A larger goal for this project was to inform the public sector more broadly and position sport as a source of best practice for human and social health, development, and performance. The objectives of this study were to review and refine the LEAD program in collaboration with Canadian Sport Institute and Centre leaders, 40-50 participants from three cohorts, and the LEAD program advisory committee, and to trace the effects of the LEAD leadership development program on key leadership mentorship and organizational health indicators across the Canadian sport institutes and centers so as to capture best practice. The study followed a participatory action research framework (PAR) using semi structured interviews with sport scientist participants, program and institute leaders inquiring into impact on specific individual and organizational health and performance factors. Findings included a strong increase in self-reported leadership knowledge, skill, language and confidence, enhancement of human and organizational health factors, and the opportunity to explore more deeply issues of diversity and inclusion, psychological safety, team dynamics, and performance management. The study was significant in building sport leadership and mentorship development strategies for managing change efforts, addressing inequalities, and building personal and operational resilience amidst challenges of uncertainty, pressure, and constraint in real time.

Keywords: sport leadership, sport science leader, leadership development, professional development, sport education, mentorship

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Authors: Nepton Kiani

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Dental decay is one of the most common chronic diseases worldwide and imposes significant costs annually on people and healthcare systems. Addressing this issue is among the important programs of the World Health Organization in the field of oral and dental disease prevention and health promotion. In this context, oral and dental health in vulnerable groups, especially pregnant women, is of greater importance due to the health maintenance of the mother and fetus. The aim of this study is to investigate the DMFT index and various factors affecting it in order to identify different factors influencing the process of dental decay and to take an effective step in reducing the progression of this disease, control, and prevention. In this cross-sectional descriptive study, 120 pregnant women attending Nepton Policlinica clinic in Malaga, Spain, were evaluated for the DMFT index and oral and dental hygiene. In this regard, interviews, precise observations, and data collection were used. Subsequently, data analysis was performed using SPSS software and employing correlation tests, Kruskal-Wallis, and Mann-Whitney tests. The DMFT index for pregnant women in three age groups 22-26, 27- 31, and 32-36 years was respectively 2.8, 4.5, and 5.6. The results of logistic regression analysis showed that demographic variables (age, education, job, economic status) and the frequency of brushing and flossing lead to preventive behavior up to 49.58 percent (P<0.05). Generally, the results indicated that oral and dental care during pregnancy is poor. Only a small number of pregnant women regularly used toothbrush and dental floss or visited the dentist regularly. On the other hand, poor performance in adopting oral and dental care was more observed in pregnant women with lower economic and educational status. The present study showed that raising the level of awareness and education on oral and dental health in pregnant women is essential. In this field, it is necessary to focus on conducting educational-care courses at the level of healthcare centers for midwives, healthcare personnel, and at the community level for families, to prevent and perform dental treatments before the pregnancy period

Keywords: Malaga, oral and dental health, pregnant women, Spain

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Authors: Josée Charette

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The academic and educational success of immigrant students is a current issue in education, especially in western societies such in the province of Quebec, in Canada. For people who immigrate with school-age children, the success of the family’s migratory project is often measured by the benefits drawn by children from the educational institutions of their host society. In order to support the academic achievement of their children, immigrant parents try to develop practices that derive from their representations of school and related challenges inspired by the socio-cultural context of their country of origin. These findings lead us to the following question: How does strategies implemented by immigrant parents to manage the representational distance between school of their country of origin and school of the host society support or not the academic and educational success of their child? In the context of a qualitative exploratory approach, we have made interviews in the French-, English- and Spanish-languages with 32 newly immigrated parents and 10 of their children. Parents were invited to complete a network of free associations about «School in Quebec» as a premise for the interview. The objective of this communication is to present strategies implemented by immigrant parents to manage the distance between their representations of schools in their country of origin and in the host society, and to explore the influence of this management on their child’s academic and educational trajectories. Data analysis led us to develop various types of strategies, such as continuity, adaptation, resources mobilization, compensation and "return to basics" strategies. These strategies seem to be part of a continuum from oppositional-conflict scenario, in which parental strategies act as a risk factor, to conciliator-integrator scenario, in which parental strategies act as a protective factor for immigrant students’ academic and educational success. In conclusion, we believe that our research helps in providing a more efficient support to immigrant parents and contributes to develop a wider portrait of immigrant students’ academic achievement. In addition, we think that by improving the experience of immigrant families in Quebec schools, a greater number of migratory projects will be effective.

Keywords: immigrant students, family’s migratory project, school of origin and school of host society, immigrants parental strategies

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