Search results for: stress measurement scale

Authors: Abdollah Ghasempour, Mohammad Reza Kavianpour, Majid Galoie

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This study has investigated the fundamental parameters which have effective role on energy dissipation of nappe flows on stepped chutes in order to estimate an empirical relationship using dimensional analysis. To gain this goal, comprehensive experimental study on some large-scale physical models with various step geometries, slopes, discharges, etc. were carried out. For all models, hydraulic parameters such as velocity, pressure, water depth, flow regime and etc. were measured precisely. The effective parameters, then, could be determined by analysis of experimental data. Finally, a dimensional analysis was done in order to estimate an empirical relationship for evaluation of energy dissipation of nappe flows on stepped chutes. Because of using the large-scale physical models in this study, the empirical relationship is in very good agreement with the experimental results.

Keywords: nappe flow, energy dissipation, stepped chute, dimensional analysis

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Authors: Ayça Utkan Karasu, Elif Balevi Batur, Gülçin Kaymak Karataş

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The aim of this study was to examine the efficiency of virtual reality exercises with Nintendo Wii system on balance and independence in motor functions. This randomized controlled assessor-blinded study included 23 stroke inpatients with hemiparesis all within 12 months poststroke. Patients were randomly assigned to control group (n=11) or experimental group (n=12) via block randomization method. Control group participated in a conventional balance rehabilitation programme. Study group received a four-week balance training programme five times per week with a session duration of 20 minutes in addition to the conventional balance rehabilitation programme. Balance was assessed by the Berg’s balance scale, the functional reach test, the timed up and go test, the postural assessment scale for stroke, the static balance index. Also, displacement of centre of pressure sway and centre of pressure displacement during weight shifting was calculated by Emed-SX system. Independence in motor functions was assessed by The Functional Independence Measure (FIM) ambulation and FIM transfer subscales. The outcome measures were evaluated at baseline, 4th week (posttreatment), 8th week (follow-up). Repeated measures analysis of variance was performed for each of the outcome measure. Significant group time interaction was detected in the scores of the Berg’s balance scale, the functional reach test, eyes open anteroposterior and mediolateral center of pressure sway distance, eyes closed anteroposterior center of pressure sway distance, center of pressure displacement during weight shifting to effected side, unaffected side and total centre of pressure displacement during weight shifting (p < 0.05). Time effect was statistically significant in the scores of the Berg’s balance scale, the functional reach test, the timed up and go test, the postural assessment scale for stroke, the static balance index, eyes open anteroposterior and mediolateral center of pressure sway distance, eyes closed mediolateral center of pressure sway distance, the center of pressure displacement during weight shifting to effected side, the functional independence measure ambulation and transfer scores (p < 0.05). Virtual reality exercises with Nintendo Wii system combined with a conventional balance rehabilitation programme enhances balance performance and independence in motor functions in stroke patients.

Keywords: balance, hemiplegia, stroke rehabilitation, virtual reality

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Authors: Chen Zheng, Lin Zhou, Bao Xie, Xiao Du, Nianbin Shao

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Power generated by large-scale photovoltaic plants (LSPVPs) is usually transmitted to the grid through several transformers and long distance overhead lines. Impedance of transformers and transmission lines results in complex interactions between the plant and the grid and among different inverters. In accordance with the topological structure of LSPV in reality, an equivalent model containing different inverters was built and then interactions between the plant and the grid and among different inverters were studied. Based on the vector composition principle of voltage at the point of common coupling (PCC), the mathematic function of PCC voltage in regard to the total power and grid impedance was deduced, from which the uttermost total power to guarantee the system stable is obtained. Taking the influence of different inverters numbers and the length of transmission lines to the system stability into account, the stability criterion of LSPV containing different inverters was derived. The result of simulation validated the theory analysis in the paper.

Keywords: LSPVPs, stability analysis, grid impedance, different types of inverter, PCC voltage

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Authors: Christopher Manyamba

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Women in Malawi produce perform between 50-70 percent of all agricultural tasks and yet the majority remain food insecure. The aim of his paper is to build on existing mixed evidence that indicates that empowering women in agriculture is conducive to improving food security. The WEAI is used to provide evidence on the relationship between women’s empowerment in agriculture and household food security. A multinomial logistic regression is applied to the Women Empowerment in Agriculture Index (WEAI) components and the Household Hunger Scale. The overall results show that the WEAI can be used to determine household food insecurity; however it has to be contextually adapted. Assets ownership, credit, group membership and leisure time are positively associated with food security. Contrary to other literature, empowerment in having control and decisions on income indicate negative association with household food security. These results could potentially better inform public, private and civil society stakeholders’ dialogues in creating the most effective and sustainable interventions to help women attain long-term food security.

Keywords: food security, gender, empowerment, agriculture index, framework for African food security, household hunger scale

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Authors: Yihao Kuang, Bowen Ding

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With the increasing scale and complexity of knowledge graph, modern knowledge graph contains more and more types of entity, relationship, and attribute information. Therefore, in recent years, it has been a trend for knowledge graph inference to use reinforcement learning to deal with large-scale, incomplete, and noisy knowledge graph and improve the inference effect and interpretability. The Proximal Policy Optimization (PPO) algorithm utilizes a near-end strategy optimization approach. This allows for more extensive updates of policy parameters while constraining the update extent to maintain training stability. This characteristic enables PPOs to converge to improve strategies more rapidly, often demonstrating enhanced performance early in the training process. Furthermore, PPO has the advantage of offline learning, effectively utilizing historical experience data for training and enhancing sample utilization. This means that even with limited resources, PPOs can efficiently train for reinforcement learning tasks. Based on these characteristics, this paper aims to obtain better and more efficient inference effect by introducing PPO into knowledge inference technology.

Keywords: reinforcement learning, PPO, knowledge inference, supervised learning

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Authors: D. Bäcker, H. Chaves

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The key to improve surface cleaning of the fouling is understanding of the mechanism of separation process of the deposit from the surface. The authors give basic principles of characterization of separation process and introduce a corresponding criterion. The developed criterion is a measure for the moment of separation of the deposit from the surface. For this purpose a new measurement technique is described.

Keywords: cleaning, fouling, separation, criterion

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Authors: Kemal Kehan, Emine Aktas Bajalan

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This study was carried out to determine the burnout levels and related factors of teachers working in primary schools affiliated to the Turkish Republic of Northern Cyprus (TRNC) Ministry of National Education during the COVID-19 pandemic period. The research was conducted in descriptive cross-sectional design. The population of the research consists of 1071 teachers working in 93 primary schools in 6 central districts affiliated to the TRNC Ministry of National Education in the 2021-2022 academic year. When the sample size of the study was calculated by power analysis, it was determined that 202 teachers should be reached with 95% confidence (1-α), 95% test power (1-β) and d=0.5 effect size. Within the scope of the inclusion criteria of the research, the main sample of the study consisted of 300 teachers and the baist random sampling method was used. The data were collected using the Sociodemographic Data Form consisting of 34 questions, including the sociodemographic characteristics of the teachers and the 22-item Maslach Burnout Scale (MBS). The analysis of the data was carried out using descriptive and correlational analyzes in the SPSS 22 package program. In the study, it was determined that 65% of the teachers were women, 68% were married, 84% had a bachelor's degree, 70.33% had children, and 67.67% were dependents. Regarding how teachers evaluate the COVID-19 pandemic period; 90% of them said, “I am worried about my family's health and the risk of infection”, 80% of them, “I feel that my profession does not get the value it deserves”, 75.67% of them mentioned “My hopes for the future have started to wane”, 75.33% of them say “I am worried about my own health”. It was determined that they gave the answer of, “I am worried about the issue”. It was found that the teachers' MBS total score average was 48.63±8.01, the burnout level was moderate, and the average score they got from the sub-dimensions of the scale was also moderate. It has been found that there are negative correlations between the professional satisfaction scores of the teachers during and before the COVID-19 pandemic and the scores they received from the general and sub-dimensions of MBS. It was determined that there was a statistically significant difference (p<0.05) between the scores of teachers diagnosed with COVID-19 from the scale and its sub-dimensions. As a result, it is suggested that social activities should be increased and professional development and promotion opportunities should be offered in order to ensure that teachers are satisfied with their work areas, to reduce their burnout levels or to prevent them completely.

Keywords: teachers, burnout, maslach burnout scale, pandemic, online education

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Authors: Chevonne Reynolds, Robert J. Fletcher, Jr, Celine M. Carneiro, Nicole Jennings, Alison Ke, Michael C. LaScaleia, Mbhekeni B. Lukhele, Mnqobi L. Mamba, Muzi D. Sibiya, James D. Austin, Cebisile N. Magagula, Themba’alilahlwa Mahlaba, Ara Monadjem, Samantha M. Wisely, Robert A. McCleery

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A key challenge for the developing world is reconciling biodiversity conservation with the growing demand for food. In these regions, agriculture is typically interspersed among other land-uses creating heterogeneous landscapes. A primary hypothesis for promoting biodiversity in agricultural landscapes is the habitat heterogeneity hypothesis. While there is evidence that landscape heterogeneity positively influences biodiversity, the application of this hypothesis is hindered by a need to determine which components of landscape heterogeneity drive these effects and at what spatial scale(s). Additionally, whether diverse taxonomic groups are similarly affected is central for determining the applicability of this hypothesis as a general conservation strategy in agricultural mosaics. Two major components of landscape heterogeneity are compositional and configurational heterogeneity. Disentangling the roles of each component is important for biodiversity conservation because each represents different mechanisms underpinning variation in biodiversity. We identified a priori independent gradients of compositional and configurational landscape heterogeneity within an extensive agricultural mosaic in north-eastern Swaziland. We then tested how bird, dung beetle, ant and meso-carnivore diversity responded to compositional and configurational heterogeneity across six different spatial scales. To determine if a general trend could be observed across multiple taxa, we also tested which component and spatial scale was most influential across all taxonomic groups combined, Compositional, not configurational, heterogeneity explained diversity in each taxonomic group, with the exception of meso-carnivores. Bird and ant diversity was positively correlated with compositional heterogeneity at fine spatial scales < 1000 m, whilst dung beetle diversity was negatively correlated to compositional heterogeneity at broader spatial scales > 1500 m. Importantly, because of these contrasting effects across taxa, there was no effect of either component of heterogeneity on the combined taxonomic diversity at any spatial scale. The contrasting responses across taxonomic groups exemplify the difficulty in implementing effective conservation strategies that meet the requirements of diverse taxa. To promote diverse communities across a range of taxa, conservation strategies must be multi-scaled and may involve different strategies at varying scales to offset the contrasting influences of compositional heterogeneity. A diversity of strategies are likely key to conserving biodiversity in agricultural mosaics, and we have demonstrated that a landscape management strategy that only manages for heterogeneity at one particular scale will likely fall short of management objectives.

Keywords: agriculture, biodiversity, composition, configuration, heterogeneity

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Authors: Mohammed Zaki, Hayder Rasheed

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This paper evaluates the flexural response of sand-lightweight Perlite concrete using full-scale reinforced concrete T beams strengthened and anchored with carbon fiber reinforced polymer (CFRP) materials. Four specimens were prepared with the same geometry, steel reinforcements, concrete properties, and span lengths. The anchored beams had a similar number of CFRP sheets but were secured utilizing different arrangements of CFRP fiber anchors. That will allow for effective and easily making comparisons to examine the flexural strengthening behavior of sand-lightweight Perlite concrete beams with anchors. The experimental outcomes were also compared with the numerical study and the comparisons were discussed. The test results showed an improvement in flexural behavior due to the use of CFRP sheets and anchors. Interestingly, the anchored beams recorded similar ultimate strength regardless of the number of CFRP fiber anchors used due to the failure by excessive wide cracks in the concrete.

Keywords: perlite concrete, CFRP fiber anchors, lightweight concrete, full-scale T-beams

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Authors: Gizem Akcan, Erdinc Ozturk

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The purpose of the study was to determine some psychosocial variables that predict dissociation in university students. These psychosocial variables were perceived childhood trauma, alexithymia, and gender. 150 (75 males, 75 females) university students (bachelor, master and postgraduate) were enrolled in this study. They were chosen from universities in Istanbul at the education year of 2016-2017. Dissociative Experiences Scale (DES), Childhood Trauma Questionnaire (CTQ) and Toronto Alexithymia Scale were used to assess related variables. Demographic Information Form was given to students in order to have their demographic information. Frequency Distribution, Linear Regression Analysis, and t-test analysis were used for statistical analysis. Childhood trauma and alexithymia were found to have predictive value on dissociation among university students. However, physical abuse, physical neglect and emotional neglect sub dimensions of childhood trauma and externally-oriented thinking sub dimension of alexithymia did not have predictive value on dissociation. Moreover, there was no significant difference between males and females in terms of dissociation scores of participants.

Keywords: childhood trauma, dissociation, alexithymia, gender

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Authors: A. M. Daneshian Moghaddam, A. H. Hosseinzadeh, A. Bandehagh

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To investigate the effect of cadmium heavy metal stress on five ecotype of dill, this experiment was conducted in the greenhouse of Tabriz University and Shabestar Islamic Azad University’s laboratories with tree replications. After growing the plants, cadmium treatments (concentration 0,300, 600 µmol) were applied. The essential oil of the samples was measured by hydro distillation and using a Clevenger apparatus. Variables used in this study include: wet and dry roots and aerial part of plant, plant height, stem diameter, and root length. The results showed that different concentrations of heavy metal has statistical difference (p < 0.01) on the fresh weight, dry weight, plant height and root length but hadn’t significant difference on essential oil percentage and root length. Dill ecotypes have statistical significant difference on essential oil percent, fresh plant weight, plant height, root length, except plant dry weight. The interactions between Cd concentration and dill ecotypes have not significant effect on all traits, except root length. Maximum fresh weight (4.98 gr) and minimum amount (3.13 gr) were obtained in control trait and 600 ppm of cd concentration, respectively. Highest amount of fresh weight (4.78 gr) was obtained in Birjand ecotype. Maximum plant dry weight (1.2 gr) was obtained at control. The highest plant height (32.54 cm) was obtained in control and with applies cadmium concentrations from zero to 300 and 600 ppm was found significantly reduced in plant height.

Keywords: pollution, essential oil, ecotype, dill, heavy metals, cadmium

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Authors: An Chengrui, Yin Zi, Wu Bingbing, Ma Yuanzhu, Jin Kaixiu, Chen Xiao, Ouyang Hongwei

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Single cell RNA sequence (scRNA-seq) is one of the effective tools to study transcriptomics of biological processes. Recently, similarity measurement of cells is Euclidian distance or its derivatives. However, the process of scRNA-seq is a multi-variate Bernoulli event model, thus we hypothesize that it would be more efficient when the divergence between cells is valued with relative entropy than Euclidian distance. In this study, we compared the performances of Euclidian distance, Spearman correlation distance and Relative Entropy using scRNA-seq data of the early, medial and late stage of limb development generated in our lab. Relative Entropy is better than other methods according to cluster potential test. Furthermore, we developed KL-SNE, an algorithm modifying t-SNE whose definition of divergence between cells Euclidian distance to Kullback–Leibler divergence. Results showed that KL-SNE was more effective to dissect cell heterogeneity than t-SNE, indicating the better performance of relative entropy than Euclidian distance. Specifically, the chondrocyte expressing Comp was clustered together with KL-SNE but not with t-SNE. Surprisingly, cells in early stage were surrounded by cells in medial stage in the processing of KL-SNE while medial cells neighbored to late stage with the process of t-SNE. This results parallel to Heatmap which showed cells in medial stage were more heterogenic than cells in other stages. In addition, we also found that results of KL-SNE tend to follow Gaussian distribution compared with those of the t-SNE, which could also be verified with the analysis of scRNA-seq data from another study on human embryo development. Therefore, it is also an effective way to convert non-Gaussian distribution to Gaussian distribution and facilitate the subsequent statistic possesses. Thus, relative entropy is potentially a better way to determine the divergence of cells in scRNA-seq data analysis.

Keywords: Single cell RNA sequence, Similarity measurement, Relative Entropy, KL-SNE, t-SNE

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Authors: Brian J. Kozak, Joshua D. Shipman, Peng Hao Wang, Blake Shipp

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The unmanned aerial system (UAS) industry is growing at a rapid pace. This growth has increased the demand for low cost, custom made and high strength unmanned aerial vehicles (UAV). The area of most growth is in the area of 25 kg to 200 kg vehicles. Vehicles this size are beyond the size and scope of simple wood and fabric designs commonly found in hobbyist aircraft. These high end vehicles require stronger materials to complete their mission. Traditional aircraft construction materials such as aluminum are difficult to use without machining or advanced computer controlled tooling. However, by using general aviation composite aircraft homebuilding techniques and materials, a large scale UAV can be constructed cheaply and easily. Furthermore, these techniques could be used to easily manufacture cost made composite shapes and airfoils that would be cost prohibitive when using metals. These homebuilt aircraft techniques are being demonstrated by the researchers in the construction of a 75 kg aircraft.

Keywords: composite aircraft, homebuilding, unmanned aerial system industry, UAS, unmanned aerial vehicles, UAV

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Authors: Harsha Thaira, Ritu Raval, Keyur Raval

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Melanin has immense applications in the field of agriculture, cosmetics and pharmaceutical industries due to its photo-protective, UV protective and anti- oxidant activities. However, its production is limited to costly chemical methods or harsh extractive methods from hair which ultimately gives poor yields. This makes the cost of melanin very high, to the extent of US Dollar 300 per gram. Some microorganisms are reported to produce melanin under stress conditions. Out of all melanin producing organisms, Pseudomonas stutzeri can grow in sea water and produce melanin under saline stress. The objective of this study was to develop a sea water based bioprocess. Effects of different growth media and process parameters on melanin production using sea water were investigated. The marine bacterial strain Pseudomonas stutzeri HMGM-7(MTCC 11712) was selected and the effect of different media such as Nutrient Broth (NB), Luria Bertini (LB) broth, Bushnell- Haas broth (BHB) and Trypticase Soy broth (TSB) and various medium components were investigated with one factor at a time approach. Parameters like shaking frequency, inoculum age, inoculum size, pH and temperature were also investigated in order to obtain the optimum conditions for maximum melanin production. The highest yield of melanin concentration, 0.306 g/L, was obtained in Trypticase Soy broth at 36 hours. The yield was 1.88 times higher than the melanin obtained before optimization, 0.163 g/L at 36 hours. Studies are underway to optimize medium constituents to further enhance melanin production.

Keywords: melanin, marine, bioprocess, pseudomonas

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Authors: Sa`ad M. Ismail, Hung-Hsun Yen, Christina M. Murray, Helen M. S. Davies

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The lumbosacral junction (where the 7th lumbar vertebra (L7) articulates with the sacrum) is a clinically important area in the dog. The 7th lumbar vertebra (L7) is normally shorter than other lumbar vertebrae, and it has been reported that variations in the L7 length may be associated with other abnormal anatomical findings. These variations included the reduction or absence of the portion of the median sacral crest. In this study, 53 greyhound cadavers were placed in right lateral recumbency, and two lateral radiographs were taken of the lumbosacral region for each greyhound. The length of the 6th lumbar (L6) vertebra and L7 were measured using radiographic measurement software and was defined to be the mean of three lines drawn from the caudal to the cranial edge of the L6 and L7 vertebrae (a dorsal, middle, and ventral line) between specific landmarks. Sacrocaudal fusion was found in 41.5% of the greyhounds. The mean values of the length of L6, L7, and the ratio of the L6/L7 length of the greyhounds with sacrocaudal fusion were all greater than those with standard sacrums (three sacral vertebrae). There was a significant difference (P < 0.05) in the mean values of the length of L7 between the greyhounds without sacrocaudal fusion (mean = 29.64, SD ± 2.07) and those with sacrocaudal fusion (mean = 30.86, SD ± 1.80), but, there was no significant difference in the mean value of the length of the L6 measurement. Among different types of sacrocaudal fusion, the longest L7 was found in greyhounds with sacrum type D, intermediate length in those with sacrum type B, and the shortest was found in those with sacrums type C, and the mean values of the ratio of the L6/L7 were 1.11 (SD ± 0.043), 1.15, (SD ± 0.025), and 1.15 (SD ± 0.011) for the types B, C, and D respectively. No significant differences in the mean values of the length of L6 or L7 were found among the different types of sacrocaudal fusion. The occurrence of sacrocaudal fusion might affect direct anatomically connected structures such as the L7. The variation in the length of L7 between greyhounds with sacrocaudal fusion and those without may reflect the possible sequences of the process of fusion. Variations in the length of the L7 vertebra in greyhounds may be associated with the occurrence of sacrocaudal fusion. The variation in the vertebral length may affect the alignment and biomechanical properties of the sacrum and may alter the loading. We concluded that any variations in the sacrum anatomical features might change the function of the sacrum or the surrounding anatomical structures.

Keywords: biomechanics, Greyhound, sacrocaudal fusion, locomotion, 6th Lumbar (L6) Vertebra, 7th Lumbar (L7) Vertebra, ratio of the L6/L7 length

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Authors: Raghabendra Yadav, Baochun Chen, Huihui Yuan, Zhibin Lian

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Pseudo-dynamic test (PDT) method is an advanced seismic test method that combines loading technology with computer technology. Large-scale models or full scale seismic tests can be carried out by using this method. CFST-RC columns are used in civil engineering structures because of their better seismic performance. A CFST-RC column is composed of four CFST limbs which are connected with RC web in longitudinal direction and with steel tube in transverse direction. For this study, a CFST-RC pier is tested under Four different earthquake time histories having scaled PGA of 0.05g. From the experiment acceleration, velocity, displacement and load time histories are observed. The dynamic magnification factors for acceleration due to Elcentro, Chi-Chi, Imperial Valley and Kobe ground motions are observed as 15, 12, 17 and 14 respectively. The natural frequency of the pier is found to be 1.40 Hz. The result shows that this type of pier has excellent static and earthquake resistant properties.

Keywords: bridge pier, CFST-RC pier, pseudo dynamic test, seismic performance, time history

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Authors: Sara Lamari, Toufik Madani

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This study aimed to explore the relationship between reproduction performances and coat characteristics of Montbéliarde cows born in Algeria or imported from Europe during the hot season in Algeria. Hair coat traits (hair coat color, Hair Weight, hair length, the number of hair per unit area, total hair diameters and hair medulla diameters) were estimated in 18 imported cattle and 49 locally born cows. These traits were measured in an area of 20cm below the dorsal line in the center of the thorax. Results showed that hair coats were significantly different between locally born and imported cows. Imported cows had whiter coats when compared to locally born cows for Montbéliarde cows. A significant effect of total hair diameter was observed on the interval from calving to conception (IC) for imported Montbéliarde cows, suggesting less incidence of heat stress on reproduction efficiency of cows with thin diameter hair coats. Montbéliarde cows with short hair coat registered significantly more number of mating per conception (2, 28±1, 93 Vs. 1,67±0,92) and IC (98,04±78,81Vs 74.53 ± 35.60 days) when compared to cows with long hairs. Hair works as a temperature regulator in association with muscles in the skin and may affect reproduction performances during hit stress season. It can be assumed that the length and a total diameter of hairs for the Montbeliarde breed appears to be related to their reproductive efficiency.

Keywords: hair coat, reproduction, Montbeliarde cow, hot season

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Authors: Lize Tibiriçá, Ronnie Lee, Samantha Behbahani

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Fibromyalgia (FM) is a musculoskeletal disorder affecting men and women of different ages and cultures. The cause of this disorder is unknown; however, studies suggest an etiology that involves biological and psychosocial factors. Few studies have shown that a personality type such as neuroticism is associated with chronic pain conditions. Past research has explored whether patients with FM present with a specific personality trait. However, studies have used different methods (i.e. Minnesota Multiphasic Personality Inventory (MMPI), Sociotropy and Autonomy Scale (SAS) and Dysfunctional Attitude Scale (DAS), Tridimensional Personality Questionnaire or Temperament and Character Inventory (TCI), Karolinska scale of personality, Big Five Inventory or NEO Personality Inventory) to explore the connection between FM and a personality type. They have identified personality types that present similar characteristics but vary in the name (i.e. high harm avoidance and low novelty seeking, psychasthenia/muscular tension/somatic anxiety, neuroticism). Although Zuckerman-Kuhlman Personality Questionnaire and the Big Five Inventory differ in terms of content and structure, both of them identify neuroticism as the personality type of FM patients, and the former also identifies these patients as having a low sociability personality trait. Previous research also shows a trend of sociotropic personality style with FM patients that also suffer from Major Depressive Disorder. Participants in these studies were, for the most part, adult female and researchers have recognized that as a limitation and whether their findings can be generalized to men and younger patients with FM. Furthermore, most studies reviewed were conducted in Europe (i.e. Spain) and had a cross-sectional design. Future research should replicate past studies in different countries and consider conducting a longitudinal study. Although it is suspected that FM course is modulated by FM patients’ personality, it is not known whether individuals with similar personalities will develop FM. This review sought to explain the differences and similarities between the personality types identified. Limitations in the studies reviewed were addressed, and considerations for future research and treatment were discussed.

Keywords: chronic pain, fibromyalgia, neuroticism, personality type

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Authors: Krishnaiah Arkanti, Ramulu Malothu

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The experiments have been conducted to study the mechanical properties of commercially pure copper processing at room temperature by severe plastic deformation using equal channel angular extrusion (ECAE) through a die of 90^oangle up to 3 passes by route B_C i.e. rotating the sample in the same direction by 90^o after each pass. ECAE is used to produce from existing coarse grains to ultra-fine, equiaxed grains structure with high angle grain boundaries in submicron level by introducing a large amount of shear strain in the presence of hydrostatic pressure into the material without changing billet shape or dimension. Mechanical testing plays an important role in evaluating fundamental properties of engineering materials as well as in developing new materials and in controlling the quality of materials for use in design and construction. Yield stress, ultimate tensile stress and ductility are structure sensitive properties and vary with the structure of the material. Microhardness and tensile tests were carried out to evaluate the hardness, strength and ductility of the ECAE processed materials. The results reveal that the strength and hardness of commercially pure copper samples improved significantly without losing much ductility after each pass.

Keywords: equal channel angular extrusion, severe plastic deformation, copper, mechanical properties

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Authors: I. Wiemann, N. Weiß, E. Schlücker, M. Wensing

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A very promising alternative to compression or cryogenics is the chemical storage of hydrogen by liquid organic hydrogen carriers (LOHC). These carriers enable high energy density and allow, at the same time, efficient and safe storage under ambient conditions without leakage losses. Another benefit of this storage medium is the possibility of transporting it using already available infrastructure for the transport of fossil fuels. Efficient use of LOHC is related to precise process control, which requires a number of sensors in order to measure all relevant process parameters, for example, to measure the level of hydrogen loading of the carrier. The degree of loading is relevant for the energy content of the storage carrier and simultaneously represents the modification in the chemical structure of the carrier molecules. This variation can be detected in different physical properties like permittivity, viscosity, or density. E.g., each degree of loading corresponds to different viscosity values. Conventional measurements currently use invasive viscosity measurements or near-line measurements to obtain quantitative information. This study investigates permittivity changes resulting from changes in hydrogenation degree (chemical structure) and temperature. Based on calibration measurements, the degree of loading and temperature of LOHC can thus be determined by comparatively simple permittivity measurements in a cavity resonator. Subsequently, viscosity and density can be calculated. An experimental setup with a heating device and flow test bench was designed. By varying temperature in the range of 293,15 K -393,15 K and flow velocity up to 140 mm/s, corresponding changes in the resonation frequency were determined in the hundredths of the GHz range. This approach allows inline process monitoring of hydrogenation of the liquid organic hydrogen carrier (LOHC).

Keywords: hydrogen loading, LOHC, measurement, permittivity, viscosity

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Authors: Ephrem Getahun, Shengwen Qi, Songfeng Guo, Yu Zou, Melesse Alemayehu

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Residual shear characteristics of slide soil profile sections (SSPS) were examined using ring shear tests to know the relative residual shear behaviors among the sections of slide soil. The multistage-multiphase shearing techniques were employed to perform the experiment for each soil specimen continuously towards large displacements. The grain distribution analysis of SSPS samples was characterized by coarsening upward from bottom slip to the top sections; however, the slip surface was considered as a sheared zone that endorses their low shear resistance for failure. There is an average range of 1-2.5 mm axial displacement on each stage of loadings and phases of shearing that depicts the significant effect of dilation and compression of soil specimen. The middle section has the largest consolidation percentage (10-29%), and vertical displacement compared to other sections and showed high shear strengthening behavior having maximum shear stress of 189kPa at 240kPa loading compared to basal and top sections. It is found that the middle section of SSPS has relatively high shear resistance behavior for large displacement shearing. The residual shear assessment indicates that there is a significant influence of large displacement and rate on the friction coefficient behaviors; it resulted in shear weakening effect to attain their residual condition.

Keywords: comparison, displacements, residual shear stress, shear behavior, slide soils

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Authors: Anila Xhahysa, Migena Ceyhan, Neki Kuka, Klajdi Qoshi, Damiano Koxhaj

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The seismic event catalog has been updated in the framework of a bilateral project supported by the Central European Investment Fund and with the extensive support of Global Earthquake Model Foundation to update Albania's national seismic hazard model. The earthquake catalogue prepared within this project covers the Western Balkan area limited by 38.0° - 48°N, 12.5° - 24.5°E and includes 41,806 earthquakes that occurred in the region between 510 BC and 2022. Since the moment magnitude characterizes the earthquake size accurately and the selected ground motion prediction equations for the seismic hazard assessment employ this scale, it was chosen as the uniform magnitude scale for the catalogue. Therefore, proxy values of moment magnitude had to be obtained by using new magnitude conversion equations between the local and other magnitude types to this unified scale. The Global Centroid Moment Tensor Catalogue was considered the most authoritative for moderate to large earthquakes for moment magnitude reports; hence it was used as a reference for calibrating other sources. The best fit was observed when compared to some regional agencies, whereas, with reports of moment magnitudes from Italy, Greece and Turkey, differences were observed in all magnitude ranges. For teleseismic magnitudes, to account for the non-linearity of the relationships, we used the exponential model for the derivation of the regression equations. The obtained regressions for the surface wave magnitude and short-period body-wave magnitude show considerable differences with Global Earthquake Model regression curves, especially for low magnitude ranges. Moreover, a conversion relation was obtained between the local magnitude of Albania and the corresponding moment magnitude as reported by the global and regional agencies. As errors were present in both variables, the Deming regression was used.

Keywords: regression, seismic catalogue, local magnitude, tele-seismic magnitude, moment magnitude

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Authors: A. O. Abulibdeh

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The aim of this study is to investigate and compare the changes in the Land Surface Temperature (LST) as a function of urbanization, particularly land use/land cover changes, in three cities in the UAE, mainly Abu Dhabi, Dubai, and Al Ain. The scale of this assessment will be at the macro- and micro-levels. At the macro-level, a comparative assessment will take place to compare between the four cities in the UAE. At the micro-level, the study will compare between the effects of different land use/land cover on the LST. This will provide a clear and quantitative city-specific information related to the relationship between urbanization and local spatial intra-urban LST variation in three cities in the UAE. The main objectives of this study are 1) to investigate the development of LST on the macro- and micro-level between and in three cities in the UAE over two decades time period, 2) to examine the impact of different types of land use/land cover on the spatial distribution of LST. Because these three cities are facing harsh arid climate, it is hypothesized that (1) urbanization is affecting and connected to the spatial changes in LST; (2) different land use/land cover have different impact on the LST; and (3) changes in spatial configuration of land use and vegetation concentration over time would control urban microclimate on a city scale and control macroclimate on the country scale. This study will be carried out over a 20-year period (1996-2016) and throughout the whole year. The study will compare between two distinct periods with different thermal characteristics which are the cool/cold period from November to March and warm/hot period between April and October. The best practice research method for this topic is to use remote sensing data to target different aspects of natural and anthropogenic systems impacts. The project will follow classical remote sensing and mapping techniques to investigate the impact of urbanization, mainly changes in land use/land cover, on LST. The investigation in this study will be performed in two stages. Stage one remote sensing data will be used to investigate the impact of urbanization on LST on a macroclimate level where the LST and Urban Heat Island (UHI) will be compared in the three cities using data from the past two decades. Stage two will investigate the impact on microclimate scale by investigating the LST and UHI using a particular land use/land cover type. In both stages, an LST and urban land cover maps will be generated over the study area. The outcome of this study should represent an important contribution to recent urban climate studies, particularly in the UAE. Based on the aim and objectives of this study, the expected outcomes are as follow: i) to determine the increase or decrease of LST as a result of urbanization in these four cities, ii) to determine the effect of different land uses/land covers on increasing or decreasing the LST.

Keywords: land use/land cover, global warming, land surface temperature, remote sensing

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Authors: Esmael Makarian, Ayub Elyasi, Fatemeh Saberi, Olusegun Stanley Tomomewo

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Rock mechanical investigation is one of the most crucial activities in underground operations, especially in surveys related to hydrocarbon exploration and production, geothermal reservoirs, energy storage, mining, and geotechnics. There is a wide range of traditional methods for driving, collecting, and analyzing rock mechanics data. However, these approaches may not be suitable or work perfectly in some situations, such as fractured zones. Cutting-edge technologies have been provided to solve and optimize the mentioned issues. Internet of Things (IoT), Edge, and Cloud Computing technologies (ECt & CCt, respectively) are among the most widely used and new artificial intelligence methods employed for geomechanical studies. IoT devices act as sensors and cameras for real-time monitoring and mechanical-geological data collection of rocks, such as temperature, movement, pressure, or stress levels. Structural integrity, especially for cap rocks within hydrocarbon systems, and rock mass behavior assessment, to further activities such as enhanced oil recovery (EOR) and underground gas storage (UGS), or to improve safety risk management (SRM) and potential hazards identification (P.H.I), are other benefits from IoT technologies. EC techniques can process, aggregate, and analyze data immediately collected by IoT on a real-time scale, providing detailed insights into the behavior of rocks in various situations (e.g., stress, temperature, and pressure), establishing patterns quickly, and detecting trends. Therefore, this state-of-the-art and useful technology can adopt autonomous systems in rock mechanical surveys, such as drilling and production (in hydrocarbon wells) or excavation (in mining and geotechnics industries). Besides, ECt allows all rock-related operations to be controlled remotely and enables operators to apply changes or make adjustments. It must be mentioned that this feature is very important in environmental goals. More often than not, rock mechanical studies consist of different data, such as laboratory tests, field operations, and indirect information like seismic or well-logging data. CCt provides a useful platform for storing and managing a great deal of volume and different information, which can be very useful in fractured zones. Additionally, CCt supplies powerful tools for predicting, modeling, and simulating rock mechanical information, especially in fractured zones within vast areas. Also, it is a suitable source for sharing extensive information on rock mechanics, such as the direction and size of fractures in a large oil field or mine. The comprehensive review findings demonstrate that digital transformation through integrated IoT, Edge, and Cloud solutions is revolutionizing traditional rock mechanical investigation. These advanced technologies have empowered real-time monitoring, predictive analysis, and data-driven decision-making, culminating in noteworthy enhancements in safety, efficiency, and sustainability. Therefore, by employing IoT, CCt, and ECt, underground operations have experienced a significant boost, allowing for timely and informed actions using real-time data insights. The successful implementation of IoT, CCt, and ECt has led to optimized and safer operations, optimized processes, and environmentally conscious approaches in underground geological endeavors.

Keywords: rock mechanical studies, internet of things, edge computing, cloud computing, underground surveys, geological operations

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Authors: Mirzaii Khadigeh

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Background and objectives: Sexual health education is an important part of health promotion services. The major role of sex education is on mothers’ shoulders. So, they have to be equipped with enough knowledge, attitude and self-efficacy for teens’ education. The present study aimed to determine the effect of team-learning and multimedia software on mothers’ knowledge, attitudes and self-efficacy in sexual health education to 12-14-year-old sons in Mashhad in 1395. Materials and methods: In this research, two experimental and one control group were employed using random sampling, which was done on 132 mothers of high school pupils. They were randomly assigned into experimental and control groups. The data were collected using demographic information and a researcher-constructed questionnaire to investigate the mothers’ knowledge, attitude, and self-efficacy and DASS21(The Depression, Anxiety and Stress Scale). They were run after confirming their reliability and validity. Intervention for the multimedia group was in the form of four CDs- each for 45 minutes- that were given to the mothers each week. At the end of the fourth week, a question-and-answer session was administered for 60 minutes. The team-learning group received intervention once a week (totally four weeks). Two weeks later, the data were collected and analyzed via Chi-square, Fisher, Kruskal-Wallis and ANOVA. Findings: Knowledge, attitude and self-efficacy of mothers in sexual health before the intervention did not have any significant differences (p >0.05). At the end of the study, the difference between the scores of the knowledge, attitude and self-efficacy in the three groups was meaningfully different (p < 0/001), but the difference between the two groups of multimedia and team-learning was not significant (p> 0.05 ). Discussion and conclusion: The result reported the efficacy of both team-leaning and multimedia software, which implies that the multimedia software training method was as effective as team-learning training one on the knowledge, attitude and self-efficacy of mothers. But, the multimedia training method is highly advised due to its availability, flexibility, and interest.

Keywords: training one on the knowledge, attitude, self-efficacy of mothers, boys

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Authors: Naheed Malik, Marisa Smith

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This study has been undertaken as an attempt to explore the underlying reasons that cause higher employee turnover rates at the call centers of Pakistan. This research also aimed to examine the relationship among the job related variables such as job satisfaction, organizational commitment, supervisor support, self-esteem, organizational stressors (work overload, role ambiguity and work family conflict) and quitting inclination. A total of 340 call centers respondents filled the survey questionnaire. The data was analyzed through SPSS 19.0. Results reveal the significant relationship among the study variables and stress level contributing more towards employee penchant to leave the job. A significant amount of call centers employee have proclivity to quit from their jobs as soon as they would be able to find some other jobs with attractive compensation. The majority of the respondents were found to be unhappy and dissatisfied due to hectic schedule and imbalance between family and work. This research also highlighted the specific areas in which call centre management needs to emphasize deliberately that affect more sharply on employee leaving aptitude. This study also suggests some useful strategies for the well being of employees that can minimize their tendency of quitting and retention in the long run.

Keywords: call centers, stress, job satisfaction, organizational commitment, supervisor’s support, self esteem, employee turnover, employees’ intention to quit, customer service representative (CSRs)

Procedia PDF Downloads 278

Authors: Kai Liu

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Remote sensing-derived land surface temperature (LST) can provide an indication of the temporal and spatial patterns of surface evapotranspiration (ET). However, the spatial resolution achieved by existing commonly satellite products is ~1 km, which remains too coarse for ET estimations. This paper proposed a model that can disaggregate coarse resolution MODIS LST at 1 km scale to fine spatial resolutions at the scale of 250 m. Our approach attempted to weaken the impacts of soil moisture and growing statues on LST variations. The proposed model spatially disaggregates the coarse thermal data by using a non-linear model involving Bowen ratio, normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI). This LST disaggregation model was tested on two heterogeneous landscapes in central Iowa, USA and Heihe River, China, during the growing seasons. Statistical results demonstrated that our model achieved better than the two classical methods (DisTrad and TsHARP). Furthermore, using the surface energy balance model, it was observed that the estimated ETs using the disaggregated LST from our model were more accurate than those using the disaggregated LST from DisTrad and TsHARP.

Keywords: Bowen ration, downscaling, evapotranspiration, land surface temperature

Procedia PDF Downloads 323

Authors: Imran Hanif, Amanda Persdotter, Sedigheh Bigdeli, Jesper Liske, Torbjorn Jonsson

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Renewable fuels such as biomass/waste for power production is an attractive alternative to fossil fuels in order to achieve a CO₂ -neutral power generation. However, the combustion results in the release of corrosive species. This puts high demands on the corrosion resistance of the alloys used in the boiler. Stainless steels containing nickel and/or nickel containing coatings are regarded as suitable corrosion resistance material especially in the superheater regions. However, the corrosive environment in the boiler caused by the presence of water vapour and reactive alkali very rapidly breaks down the primary protection, i.e., the Cr-rich oxide scale formed on stainless steels. The lifetime of the components, therefore, relies on the properties of the oxide scale formed after breakaway, i.e., the secondary protection. The aim of the current study is to investigate the role of varying nickel content (0–82%) on the high-temperature corrosion of model alloys with 18% Cr (Fe in balance) in the laboratory mimicking industrial conditions at 600°C. The influence of nickel is investigated on both the primary protection and especially the secondary protection, i.e., the scale formed after breakaway, during the oxidation/corrosion process in the dry O₂ (primary protection) and more aggressive environment such as H₂O, K₂CO₃ and KCl (secondary protection). All investigated alloys experience a very rapid loss of the primary protection, i.e., the Cr-rich (Cr, Fe)₂O₃, and the formation of secondary protection in the aggressive environments. The microstructural investigation showed that secondary protection of all alloys has a very similar microstructure in all more aggressive environments consisting of an outward growing iron oxide and inward growing spinel-oxide (Fe, Cr, Ni)₃O₄. The oxidation kinetics revealed that it is possible to influence the protectiveness of the scale formed after breakaway (secondary protection) through the amount of nickel in the alloy. The difference in oxidation kinetics of the secondary protection is linked to the microstructure and chemical composition of the complex spinel-oxide. The detailed microstructural investigations were carried out using the extensive analytical techniques such as electron back scattered diffraction (EBSD), energy dispersive X-rays spectroscopy (EDS) via the scanning and transmission electron microscopy techniques and results are compared with the thermodynamic calculations using the Thermo-Calc software.

Keywords: breakaway corrosion, EBSD, high-temperature oxidation, SEM, TEM

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Authors: Matthias Walluch, José Alberto Rodríguez, Christopher Giehl, Gunther Arnold, Daniela Ehgartner

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Dynamic mechanical analysis (DMA) is a powerful method to characterize viscoelastic properties and phase transitions for a wide range of materials. It is often used to characterize polymers and their temperature-dependent behavior, including thermal transitions like the glass transition temperature Tg, via determination of storage and loss moduli in tension (Young’s modulus, E) and shear or torsion (shear modulus, G) or other testing modes. While production and application temperatures for polymers are often limited to several hundred degrees, material properties of glasses usually require characterization at temperatures exceeding 600 °C. This contribution highlights a high temperature setup for rotational and oscillatory rheometry as well as for DMA in different modes. The implemented standard convection oven enables the characterization of glass in different loading modes at temperatures up to 950 °C. Three-point bending, tension and torsional measurements on different glasses, with E and G moduli as a function of frequency and temperature, are presented. Additional tests include superimposing several frequencies in a single temperature sweep (“multiwave”). This type of test results in a considerable reduction of the experiment time and allows to evaluate structural changes of the material and their frequency dependence. Furthermore, DMA in torsion and tension was performed to determine the complex Poisson’s ratio as a function of frequency and temperature within a single test definition. Tests were performed in a frequency range from 0.1 to 10 Hz and temperatures up to the glass transition. While variations in the frequency did not reveal significant changes of the complex Poisson’s ratio of the glass, a monotonic increase of this parameter was observed when increasing the temperature. This contribution outlines the possibilities of DMA in bending, tension and torsion for an extended temperature range. It allows the precise mechanical characterization of material behavior from room temperature up to the glass transition and the softening temperature interval. Compared to other thermo-analytical methods, like Dynamic Scanning Calorimetry (DSC) where mechanical stress is neglected, the frequency-dependence links measurement results (e.g. relaxation times) to real applications

Keywords: dynamic mechanical analysis, oscillatory rheometry, Poisson's ratio, solid glass, viscoelasticity

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Authors: Yuxiang Pan, Yong Qiu, Chenlei Gu, Ping Wang

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In the past decade, three-dimensional (3D) tumor cell models have attracted increasing interest in the field of drug screening due to their great advantages in simulating more accurately the heterogeneous tumor behavior in vivo. Drug sensitivity testing based on 3D tumor cell models can provide more reliable in vivo efficacy prediction. The gold standard fluorescence staining is hard to achieve the real-time and label-free monitoring of the viability of 3D tumor cell models. In this study, micro-groove impedance sensor (MGIS) was specially developed for dynamic and non-invasive monitoring of 3D cell viability. 3D tumor cells were trapped in the micro-grooves with opposite gold electrodes for the in-situ impedance measurement. The change of live cell number would cause inversely proportional change to the impedance magnitude of the entire cell/matrigel to construct and reflect the proliferation and apoptosis of 3D cells. It was confirmed that 3D cell viability detected by the MGIS platform is highly consistent with the standard live/dead staining. Furthermore, the accuracy of MGIS platform was demonstrated quantitatively using 3D lung cancer model and sophisticated drug sensitivity testing. In addition, the parameters of micro-groove impedance chip processing and measurement experiments were optimized in details. The results demonstrated that the MGIS and 3D cell-based biosensor and would be a promising platform to improve the efficiency and accuracy of cell-based anti-cancer drug screening in vitro.

Keywords: micro-groove impedance sensor, 3D cell-based biosensors, 3D cell viability, micro-electromechanical systems

Procedia PDF Downloads 125