Search results for: saturation index

Authors: M. A. Ferhat, M. N. Boukhatem, F. Chemat

Abstract:

Eucalyptus essential oil is extracted from Eucalyptus globulus of the Myrtaceae family and is also known as Tasmanian blue gum or blue gum. Despite the reputation earned by aromatic and medicinal plants of Algeria. The objectives of this study were: (i) the extraction of the essential oil from the leaves of Eucalyptus globulus Labill., Myrtaceae grown in Algeria, and the quantification of the yield thereof, (ii) the identification and quantification of the compounds in the essential oil obtained, and (iii) the determination of physical and chemical properties of EGEO. The chemical constituents of Eucalyptus globulus essential oil (EGEO) of Blida origin has not previously been investigated. Thus, the present study has been conducted for the determination of chemical constituents and different physico-chemical properties of the EGEO. Chemical composition of the EGEO, grown in Algeria, was analysed by Gas Chromatography-Mass Spectrometry. The chemical components were identified on the basis of Retention Time and comparing with mass spectral database of standard compounds. Relative amounts of detected compounds were calculated on the basis of GC peak areas. Fresh leaves of E. globulus on steam distillation yielded 0.96% (v/w) of essential oil whereas the analysis resulted in the identification of a total of 11 constituents, 1.8 cineole (85.8%), α-pinene (7.2%), and β-myrcene (1.5%) being the main components. Other notable compounds identified in the oil were β-pinene, limonene, α-phellandrene, γ-terpinene, linalool, pinocarveol, terpinen-4-ol, and α-terpineol. The physical properties such as specific gravity, refractive index and optical rotation and the chemical properties such as saponification value, acid number and iodine number of the EGEO were examined. The oil extracted has been analyzed to have 1.4602-1.4623 refractive index value, 0.918-0.919 specific gravity (sp.gr.), +9 - +10 optical rotation that satisfy the standards stipulated by European Pharmacopeia. All the physical and chemical parameters were in the range indicated by the ISO standards. Our findings will help to access the quality of the Eucalyptus oil which is important in the production of high value essential oils that will help to improve the economic condition of the community as well as the nation.

Keywords: chemical composition, essential oil, eucalyptol, gas chromatography

Procedia PDF Downloads 327

Authors: Hanieh Mohammadi, Sarah Fraser, Anil Nigam, Frederic Lesage, Louis Bherer

Abstract:

A chronically higher cerebral pulsatility is thought to damage cerebral microcirculation, leading to cognitive decline in older adults. Although it is widely known that regular physical activity is linked to improvement in some cognitive domains, including executive functions, the mediating role of cerebral pulsatility on this link remains to be elucidated. This study assessed the impact of 6 months of regular physical activity upon changes in an optical index of cerebral pulsatility and the role of physical activity for the improvement of executive functions. 27 older adults (aged 57-79, 66.7% women) with cardiovascular risk factors (CVRF) were enrolled in the study. The participants completed the behavioral Stroop test, which was extracted from the Delis-Kaplan executive functions system battery at baseline (T0) and after 6 months (T6) of physical activity. Near-infrared spectroscopy (NIRS) was applied for an innovative approach to indexing cerebral pulsatility in the brain microcirculation at T0 and T6. The participants were at standing rest while a NIRS device recorded hemodynamics data from frontal and motor cortex subregions at T0 and T6. The cerebral pulsatility index of interest was cerebral pulse amplitude, which was extracted from the pulsatile component of NIRS data. Our data indicated that 6 months of physical activity was associated with a reduction in the response time for the executive functions, including inhibition (T0: 56.33± 18.2 to T6: 53.33± 15.7,p= 0.038)and Switching(T0: 63.05± 5.68 to T6: 57.96 ±7.19,p< 0.001) conditions of the Stroop test. Also, physical activity was associated with a reduction in cerebral pulse amplitude (T0: 0.62± 0.05 to T6: 0.55± 0.08, p < 0.001). Notably, cerebral pulse amplitude was a significant mediator of the link between physical activity and response to the Stroop test for both inhibition (β=0.33 (0.61,0.23),p< 0.05)and switching (β=0.42 (0.69,0.11),p <0.01) conditions. This study suggests that regular physical activity may support cognitive functions through the improvement of cerebral pulsatility in older adults with CVRF.

Keywords: near-infrared spectroscopy, cerebral pulsatility, physical activity, cardiovascular risk factors, executive functions

Procedia PDF Downloads 195

Authors: Halima Albalushi, Mohadese Boroojerdi, Murtadha Alkhabori

Abstract:

Introduction: Maintenance of stem cell properties during culture necessitates the recreation of the natural cell niche. Studies reported the promising outcome of mesenchymal stem cells (MSC) properties maintenance after using extracellular matrix such as CELLstart™, which is the recommended coating material for stem cells cultured in serum-free and xeno-free conditions. Laminin-521 is known as a crucial adhesion protein, which is found in natural stem cell niche, and plays an important role in facilitating the maintenance of self-renewal, pluripotency, standard morphology, and karyotype of human pluripotent stem cells (PSCs). The aim of this study is to investigate the effects of Laminin-521 on human umbilical cord-derived mesenchymal stem cells (UC-MSC) characteristics as a step toward clinical application. Methods: Human MSC were isolated from the umbilical cord via the explant method. Umbilical cord-derived-MSC were cultured in serum-free and xeno-free conditions in the presence of Laminin-521 for six passages. Cultured cells were evaluated by morphology and expansion index for each passage. Phenotypic characterization of UC-MSCs cultured on Laminin-521 was evaluated by assessment of cell surface markers. Results: Umbilical cord derived-MSCs formed small colonies and expanded as a homogeneous monolayer when cultured on Laminin-521. Umbilical cord derived-MSCs reached confluence after 4 days in culture. No statistically significant difference was detected in all passages when comparing the expansion index of UC-MSCs cultured on LN-521 and CELLstart™. Phenotypic characterization of UC-MSCs cultured on LN-521 using flow cytometry revealed positive expression of CD73, CD90, CD105 and negative expression of CD34, CD45, CD19, CD14 and HLA-DR.Conclusion: Laminin-521 is comparable to CELLstart™ in supporting UC-MSCs expansion and maintaining their characteristics during culture in xeno-free and serum-free culture conditions.

Keywords: mesenchymal stem cells, culture, laminin-521, xeno-free serum-free

Procedia PDF Downloads 74

Authors: Yanqun Li, Hong Geng

Abstract:

The rapid urbanization process taking big cities as the main body leads to the unequal configuration of urban and rural areas in the aspects of land supply, industrial division of labor, service supply and space allocation, and induces the shrinking characterization of service energy, industrial system and population vitality in small towns. As an important spatial unit in the spectrum of urbanization that serves, connects and couples urban and rural areas, the shrinking phenomenon faced by small towns has an important influence on the healthy development of urbanization. Based on the census of small towns in Wuhan metropolitan area, we have found that the shrinking of small towns is a passive contraction of elastic tension under the squeeze in cities. Once affected by the external forces such as policy regulation, planning guidance, and population return, small towns will achieve expansion and growth. Based on the theory of complex adaptive systems, this paper comprehensively constructs the development index evaluation system of small towns from five aspects of population, economy, space, society and ecology, measures the shrinking level of small towns, further analyzes the shrinking characteristics of small towns, and identifies whether the shrinking is elastic or not. And then this paper measures the resilience ability index of small town contract from the above-mentioned five aspects. Finally, this paper proposes an adaptive mechanism of urban-rural interaction evolution under fine division of labor to response the passive shrinking in small towns of Wuhan. Based on the above, the paper creatively puts forward the planning response measures of the small towns on the aspects of spatial layout, function orientation and service support, which can provide reference for other regions.

Keywords: complex adaptive systems, resiliency shrinking, adaptation mechanism, planning response

Procedia PDF Downloads 123

Authors: Lazhar Belkhiri, Ammar Tiri, Lotfi Mouni, Fatma Elhadj Lakouas

Abstract:

This research aims to present a surface water quality assessment of hydrochemical parameters in the Kebir Rhumel Basin, Algeria. The water quality index (WQI), Mann–Kendall (MK) test, and hierarchical cluster analysis (HCA) were used in oder to understand the spatio-temporal distribution of the surface water quality in the study area. Eleven hydrochemical parameters were measured monthly at eight stations from January 2016 to December 2020. The dominant cation in the surface water was found to be calcium, followed by sodium, and the dominant anion was sulfate, followed by chloride. In terms of WQI, a significant percentage of surface water samples at stations Ain Smara (AS), Beni Haroune (BH), Grarem (GR), and Sidi Khlifa (SK) exhibited poor water quality, with approximately 89.5%, 90.6%, 78.2%, and 62.7%, respectively, falling into this category. Mann–Kendall trend analysis revealed a significantly increasing trend in WQI values at stations Oued Boumerzoug (ON) and SK, indicating that the temporal variation of WQI in these stations is significant. Hierarchical clustering analysis classified the data into three clusters. The first cluster contained approximately 22% of the total number of months, the second cluster included about 30%, and the third cluster had the highest representation, approximately 48% of the total number of months. Within these clusters, certain stations exhibited higher WQI values. In the first cluster, stations GR and ON had the highest WQI values. In the second cluster, stations Oued Boumerzoug (OB) and SK showed the highest WQI values, while in the last cluster, stations AS, BH, El Milia (EM), and Hammam Grouz (HG) had the highest mean WQI values. Also, approximately 38%, 41%, and 38% of the total water samples in the first, second, and third clusters, respectively, were classified as having poor water quality. The findings of this study can serve as a scientific basis for decision-makers to formulate strategies for surface water quality restoration and management in the region.

Keywords: surface water, water quality index (WQI), Mann Kendall (MK) test, hierarchical cluster analysis (HCA), spatial-temporal distribution, Kebir Rhumel Basin

Procedia PDF Downloads 25

Authors: Albana Kashtanjeva-Bytyçi, Idriz Vehapi, Rifat Morina, Osman Fetoshi

Abstract:

The purpose of this study is to determine the water quality in Batllava Leka through which a part of the population of the Prishtina region is supplied with drinking water. Batllava Leka is a lake built in the 70s. This lake is located in the village of Btlava in the municipality of Podujeva, with coordinates 42 ° 49′33 ″ V 21 ° 18′25 ″ L, with an area of 3.07 km2. Water supply is from the river Brvenica- Batllavë. In order to take preventive measures and improve water quality, we have conducted periodic/monthly monitoring of water quality in Lake Batllava, through microbiological and physico-chemical indicators. The monitoring was carried out during the period December 2020 - December 2021. Samples were taken at three sampling sites: at the entrance of the lake, in the middle and at the overflow, on two levels, water surface and at a depth of 30 cm. The microbiological parameters analyzed are: total coliforms, fecal coliforms, fecal streptococci, aerobic mesophilic bacteria and actinomycetes. Within the physico-chemical parameters: Dissolved Oxygen, Saturation with O2, water temperature, pH value, electrical conductivity, total soluble matter, total suspended matter, turbidity, chemical oxygen demand, biochemical oxygen demand, total organic carbon, nitrate, total hardness, hardness of calcium, calcium, magnesium, ammonium ion, chloride, sulfates, flourine, M-alkalines, bicarbonates and heavy metals, such as: Fe, Pb, Mn, Cu, Cd. The results showed that most of the physico-chemical and microbiological parameters are within the limit allowed by the WHO, except in the case of the rainiest season that exceeded some parameters.

Keywords: batllava lake, monitoring of water, physico-chemical, microbiological, heavy metals

Procedia PDF Downloads 108

Authors: Fawad Ali

Abstract:

Toxic heavy metal contamination has a negative impact on soil quality which ultimately pollutes the agriculture system. In the current work, we analyzed uptake of various heavy metals by dietary vegetables grown in wastewater irrigated areas of Swabi city. The samples of soil and vegetables were analyzed for heavy metals viz Cd, Cr, Mn, Fe, Ni, Cu, Zn and Pb using Atomic Absorption Spectrophotometer. High levels of metals were found in wastewater irrigated soil and vegetables in the study area. Especially the concentrations of Pb and Cd in the dietary vegetable crossed the permissible level of World Health Organization. Substantial positive correlation was found among the soil and vegetable contamination. Transfer factor for some metals including Cr, Zn, Mn, Ni, Cd and Cu was greater than 0.5 which shows enhanced accumulation of these metals due to contamination by domestic discharges and industrial effluents. Linear regression analysis indicated significant correlation of heavy metals viz Pb, Cr, Cd, Ni, Zn, Cu, Fe and Mn in vegetables with concentration in soil of 0.964 at P≤0.001. Abelmoschus esculentus indicated Health Risk Index (HRI) of Pb >1 in adults and children. The source identification analysis carried out by Principal Component Analysis (PCA) and Cluster Analysis (CA) showed that ground water and soil were being polluted by the trace metals coming out from industries and domestic wastes. Hierarchical cluster analysis (HCA) divided metals into two clusters for wastewater and soil but into five clusters for soil of control area. PCA extracted two factors for wastewater, each contributing 61.086 % and 16.229 % of the total 77.315 % variance. PCA extracted two factors, for soil samples, having total variance of 79.912 % factor 1 and factor 2 contributed 63.889 % and 16.023 % of the total variance. PCA for sub soil extracted two factors with a total variance of 76.136 % factor 1 being 61.768 % and factor 2 being 14.368 %of the total variance. High pollution load index for vegetables in the study area due to metal polluted soil has opened a study area for proper legislation to protect further contamination of vegetables. This work would further reveal serious health risks to human population of the study area.

Keywords: health risk, vegetables, wastewater, atomic absorption sepctrophotometer

Procedia PDF Downloads 70

Authors: Bo Hu, Mui-Choo Jong, João Frias, Irina Chubarenko, Gabriel Enrique De-la-Torre, Prabhu Kolandhasamy, Md. Jaker Hossain, Elena Esiukova, Lei Su, Hua Deng, Huahong Shi

Abstract:

Plastic debris in coastal environments undergoes a series of aging processes due to the diverse environmental conditions they are exposed to. Existing research to date lacks a thorough understanding of how these processes affect exposed and non-exposed sides of plastic fragments, leading to potentially biased conclusions on how degradation occurs. This study addresses this knowledge gap by examining surface aging characteristics on both sides (e.g., cracks, delaminations, pits, wrinkles and color residues) of 1573 plastic fragments collected from 15 coastal sites worldwide and conducting outdoor aging simulations. A clear contrast was observed between the two sides of the plastic fragments, where one of the sides often displayed more pronounced aging features. Three key indicators were introduced to quantify the aging characteristics of plastic fragments, with values ranging from 0.00 to 58.00 mm/mm2 (line density), 0.00 to 92.12% (surface loss) and 0.00 to 1.51 (texture index), respectively. Outdoor simulations revealed that sun-exposed sides of plastic sheets developed more cracks, pores, and bubbles, while the shaded sides remained smoother. The annual average solar radiation intensity of 4.47 kWh in the experimental area exacerbated the degradation of the sun-exposed side, as confirmed by a significant increase in carbonyl index, with PE rising from 0.50 to 1.70, PP from 0.18 to 1.10, and PVC from 0.45 to 1.57, indicating photoaging. These results highlight the uneven weathering patterns of plastic fragments on shorelines due to varying environmental stresses. In particular, the side facing the sun exhibited more pronounced signs of aging. Outdoor experiments confirmed that the fragments’ sun-exposed sides experienced significantly higher degrees of weathering compared to the shaded sides. This study demonstrated that the divergent weathering patterns on the two sides of beach plastic fragments were primarily driven by differences in light exposure, duration, and mechanical stress.

Keywords: plastic fragments, coastal environment, surface aging features, two-sided differences

Procedia PDF Downloads 21

Authors: Shishay Kidanu, Abdullah Alhaj

Abstract:

Sinkholes in the karst terrain of Greene County, Missouri, pose significant geohazards, imposing challenges on construction and infrastructure development, with potential threats to lives and property. To address these issues, understanding the influencing factors and modeling sinkhole susceptibility is crucial for effective mitigation through strategic changes in land use planning and practices. This study utilizes geographic information system (GIS) software to collect and process diverse data, including topographic, geologic, hydrogeologic, and anthropogenic information. Nine key sinkhole influencing factors, ranging from slope characteristics to proximity to geological structures, were carefully analyzed. The Frequency Ratio method establishes relationships between attribute classes of these factors and sinkhole events, deriving class weights to indicate their relative importance. Weighted integration of these factors is accomplished using the Analytic Hierarchy Process (AHP) and the Weighted Linear Combination (WLC) method in a GIS environment, resulting in a comprehensive sinkhole susceptibility index (SSI) model for the study area. Employing Jenk's natural break classifier method, the SSI values are categorized into five distinct sinkhole susceptibility zones: very low, low, moderate, high, and very high. Validation of the model, conducted through the Area Under Curve (AUC) and Sinkhole Density Index (SDI) methods, demonstrates a robust correlation with sinkhole inventory data. The prediction rate curve yields an AUC value of 74%, indicating a 74% validation accuracy. The SDI result further supports the success of the sinkhole susceptibility model. This model offers reliable predictions for the future distribution of sinkholes, providing valuable insights for planners and engineers in the formulation of development plans and land-use strategies. Its application extends to enhancing preparedness and minimizing the impact of sinkhole-related geohazards on both infrastructure and the community.

Keywords: sinkhole, GIS, analytical hierarchy process, frequency ratio, susceptibility, Missouri

Procedia PDF Downloads 74

Authors: Shital Bangar, Chetana Mandavia

Abstract:

A field experiment was carried out in Factorial Randomized Block Design (FRBD) with three replications at Instructional Farm Krushigadh, Junagadh Agricultural University, Junagadh, India to assess the biochemical parameters of wheat in order to assess the thermotolerance. Nine different wheat varieties GW 433, GW 431, HI 1571, GW 432, RAJ 3765, HD 2864, HI 1563, HD 3091 and PBW 670 sown in timely and late sown conditions (i.e., 22 Nov and 6 Dec 2012) were analysed. All the varieties differed significantly with respect to grain yield morpho-physiological parameters and growth indices for time of sowing, varieties and varieties x time of sowing interactions. The observations on morpho-physiological parameters viz., germination percentage, canopy temperature depression and growth indices viz., leaf area index (LAI), leaf area ratio (LAR) were recorded. Almost all the morpho-physiological parameters, growth indices and grain yield studied were affected adversely by late sowing, registering reduction in their magnitude. Germination percentage was reduced under late sown condition but variety PBW 670 was the best. Varieties GW 432 performed better with respect to canopy temperature depression while sown late. Under late sown condition, variety GW 431 recorded higher LAI while HI 1563 had maximum LAR. Considering yield performance, HD 2864 was best under timely sown condition, while GW 433 was best under late sown condition. Varieties HI 1571, GW 433 and GW 431 could be labelled as thermo-tolerant because there was least reduction in grain yield under late sown condition (1.75 %, 7.90 % and13.8 % respectively). Considering correlation coefficient, grain yield showed very strong significant positive association with germination percentage. Leaf area ratio was strongly and significantly correlated with grain yield but in negative direction. Canopy temperature depression and leaf area index also had positive correlation with grain yield but were non-significant.

Keywords: growth indices, morpho-physiological parametrs, thermo-tolerance, wheat

Procedia PDF Downloads 440

Authors: Lan Luo, Jingjing Huang, Huafang Li

Abstract:

Introduction: Distressing low sexual desire is common in China, while the lack of reliable and valid instruments to evaluate symptoms of hypoactive sexual desire disorder (HSDD) impedes related research and clinical services. Aim: This study aimed to validate the reliability and validity of the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale-Desire/Arousal/Orgasm (FSDS-DAO) in Chinese female HSDD patients. Methods: We administered FSFI and FSDS-DAO in a convenient sample of Chinese adult women. Participants were diagnosed by a psychiatrist according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). Results: We had a valid analysis sample of 279 Chinese women, of which 107 were HSDD patients. The Cronbach's α of FSFI and FSDS-DAO were 0.947 and 0.956, respectively, and the intraclass correlation coefficients of which were 0.86 and 0.89, respectively (the interval was 13-15 days). The correlation coefficient between the Revised Adult Attachment Scale (RAAS) and FSFI (or FSDS-DAO) did not exceed 0.4; the area under the receiver operating characteristic (ROC) curve was 0. 83 when combined FSFI-d (the desire domain of FSFI) and FSDS-DAO to diagnose HSDD, which was significantly different from that of using these scales individually. FSFI-d of less than 2.7 (1.2-6) and FSDS-DAO of no less than 15 (0-60) (Sensitivity 65%, Specificity 83%), or FSFI-d of no more than 3.0 (1.2-6) and FSDS-DAO of no less than 14 (0-60) (Sensitivity 74%, Specificity 77%) can be used as cutoff scores in clinical research or outpatient screening. Clinical implications: FSFI (including FSFI-d) and FSDS-DAO are suitable for the screening and evaluation of Chinese female HSDD patients of childbearing age. Strengths and limitations: Strengths include a thorough validation of FSFI and FSDS-DAO and the exploration of the cutoff score combing FSFI-d and FSDS-DAO. Limitations include a small convenience sample and the requirement of being sexually active for HSDD patients. Conclusion: FSFI (including FSFI-d) and FSDS-DAO have good internal consistency, test-retest reliability, construct validity, and criterion validity in Chinese female HSDD patients of childbearing age.

Keywords: sexual desire, sexual distress, hypoactive sexual desire disorder, scale

Procedia PDF Downloads 76

Authors: Meenakshi

Abstract:

Background: The complications during pregnancy are the major cause of morbidity and deaths among women in the reproductive age group. Childbearing is the most important phase in women’s lives that occur mainly in the adolescent and adult years. Maternal health, thus is an important issue as this as this is important phase is also productive time for women as they strive fulfill their capabilities as an individual, mothers, family members and also as a citizen. The objective of the study is to document the coverage of ANC and its determinants among domestic workers. Method: A survey of 300 domestic workers were carried in Delhi. Only respondents in the age group (15-49) and whose recent birth was of 5 years preceding the survey were included. Socio-demographic data and information on maternal health was collected from these respondents Information on ANC was collected from total 300 respondents. Standard of living index were composed based on households assists and similarly autonomy index was computed based on women decision making power in the households taking certain key variables. Cross tabulations were performed to obtain frequency and percentages. Potential socio-economic determinants of utilization of ANC among domestic workers were examined using binary logistic regressions. Results: Out of 300 domestic workers survey, only 70.7 per cent per cent received ANC. Domestic workers who married at age 18 years and above are 4 times more likely to utilize antenatal services during their last birth (***p< 0.01). Comparison to domestic workers with number of living children two or less, domestic workers with number of living children more than two are less likely to utilize antenatal care services (**p< 0.05). Domestic workers belonging to Other Backward Castes are more likely to utilize antenatal care services than domestic workers belonging to scheduled tribes ((**p< 0.05). Conclusion: The level of utilization of maternal health services are less among domestic workers is less, as they spend most of their time at the employers household. Though demonstration effect do have impact on their life styles but utilization of maternal health services is poor. Strategies and action are needed to improve the utilization of maternal health services among this section of workers as they are vulnerable because of no proper labour legislations.

Keywords: antenatal care, domestic workers, health services, maternal health, women’s health

Procedia PDF Downloads 198

Authors: Yifan Gao

Abstract:

Owing to the high breakdown field, high saturation drift velocity, 2DEG with high density and mobility and so on, AlGaN/GaN HEMTs have been widely used in high-frequency and high-power applications. To acquire a higher power often means higher breakdown voltage and higher drain current. Surface leakage current is usually the key issue affecting the breakdown voltage and power performance. In this work, we have performed in-situ N₂/NH₃ pretreatment before the passivation to suppress the surface leakage and achieve device performance enhancement. The AlGaN/GaN HEMT used in this work was grown on a 3-in. SiC substrate, whose epitaxial structure consists of a 3.5-nm GaN cap layer, a 25-nm Al₀.₂₅GaN barrier layer, a 1-nm AlN layer, a 400-nm i-GaN layer and a buffer layer. In order to analyze the mechanism for the N-based pretreatment, the details are measured by XPS analysis. It is found that the intensity of Ga-O bonds is decreasing and the intensity of Ga-N bonds is increasing, which means with the supplement of N, the dangling bonds on the surface are indeed reduced with the forming of Ga-N bonds, reducing the surface states. The surface states have a great influence on the leakage current, and improved surface states represent a better off-state of the device. After the N-based pretreatment, the breakdown voltage of the device with Lₛ𝒹=6 μm increased from 93V to 170V, which increased by 82.8%. Moreover, for HEMTs with Lₛ𝒹 of 6-μm, we can obtain a peak output power (Pout) of 12.79W/mm, power added efficiency (PAE) of 49.84% and a linear gain of 20.2 dB at 60V under 3.6GHz. Comparing the result with the reference 6-μm device, Pout is increased by 16.5%. Meanwhile, PAE and the linear gain also have a slight increase. The experimental results indicate that using N₂/NH₃ pretreatment before passivation is an attractive approach to achieving power performance enhancement.

Keywords: AlGaN/GaN HEMT, N-based pretreatment, output power, passivation

Procedia PDF Downloads 317

Authors: Gobena D. Bayisa, A. Mekonen, Megersa O. Dinka, Tilahun H. Nebi, M. Boja

Abstract:

Crop production in arid and semi-arid regions of Ethiopia is largely limited by water availability. Changing climate conditions and declining water resources increase the need for appropriate approaches to improve water use and find ways to increase production through reduced and more reliable water supply. In the years 2021/22 and 2022/23, a field experiment was conducted to evaluate the effect of limited irrigation water use on bread wheat (Triticum aestivum L.) production, water use efficiency, and financial benefits. Five irrigation treatments, i.e., full irrigation (100% ETc/ control), 85% ETc, 70% ETc, 55% ETc, and 40% ETc, were evaluated using a randomized complete block design (RCBD) with four replicates in the semi-arid climate condition of Awash basin of Ethiopia. Statistical analysis showed a significant effect of irrigation levels on wheat grain yield, water use efficiency, crop water response factor, economic profit, wheat grain quality, aboveground biomass, and yield index. The highest grain yield (5085 kg ha⁻¹) was obtained with 100% ETc irrigation (417.2 mm), and the lowest grain yield with 40% ETc (223.7 mm). Of the treatments, 70% ETc produced the higher wheat grain yield (4555 kg ha⁻¹), the highest water use efficiency (1.42 kg m⁻³), and the highest yield index (0.43). Using the saved water, wheat could be produced 23.4% more with a 70% ETc deficit than full irrigation on 1.38 ha of land, and it could get the highest profit (US$2563.9) and higher MRR (137%). The yield response factor and crop-water production function showed potential reductions associated with increased irrigation deficits. However, a 70% ETc deficit is optimal for increasing wheat grain yield, water use efficiency, and economic benefits of irrigated wheat production. The result indicates that deficit irrigation of wheat under the typical arid and semi-arid climatic conditions of the Awash Basin can be a viable irrigation management approach for enhancing water use efficiency while minimizing the decrease in crop yield could be considered effective.

Keywords: crop-water response factor, deficit irrigation, water use efficiency, wheat production

Procedia PDF Downloads 69

Authors: Brigita Mieziene, Arunas Emeljanovas, Vida Cesnaitiene, Ingunn Fjortoft, Lise Kjonniksen

Abstract:

Background. Health-related physical fitness refers to the favorable health status, i.e. ability to perform daily activities with vigor, as well as capacities that are associated with a low risk for development of chronic diseases and premature death. However, in school-aged children it is constantly declining, while some aspects of fitness declined as much as 50 percent during the last two decades, which prognosticates increasingly earlier onset of health problems, decreasing the quality of life of the population and financial burden for the society. Therefore, the goal of the current study was to indicate nationally representative age- and gender-specific reference values of anthropometric measures, musculoskeletal, motor and cardiorespiratory fitness in Lithuanian primary school children from 6 to 10 years. Methods. The study included 3556 students in total, from 73 randomly selected schools. Ethics approval for research by the Kaunas Regional Ethics Committee (No. BE-2-42) was obtained. Physical fitness was measured by the 9-item test battery, developed by Fjørtoft and colleagues. Height and weight were measured and body mass index calculated. Smoothed centile charts were derived using the LMS method. Results. The numerical age- and gender-specific percentile values (3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentile) for anthropometric measures, musculoskeletal, motor and cardiorespiratory fitness were provided. The equivalent smoothed LMS curves were performed. The study indicated 12.5 percent of overweight and 5 percent of obese children in accordance with international gender and age specific norms of body mass index. This data could be used in clinical and educational settings in order to identify the level of individual physical fitness within its different components.

Keywords: fitness, overweight, primary school children, reference values, smoothed percentile curves

Procedia PDF Downloads 162

Authors: Tong-Hsien Chow

Abstract:

Background: Plantar pressure measurement is an effective method for assessing plantar loading and can be applied to evaluating movement performance of the foot. The purpose of this study is to explore the sprint athletes’ plantar loading characteristics and pain profiles in static standing. Methods: Experiments were undertaken on 80 first-division college sprint athletes and 85 healthy non-sprinters. ‘JC Mat’, the optical plantar pressure measurement was applied to examining the differences between both groups in the arch index (AI), three regional and six distinct sub-regional plantar pressure distributions (PPD), and footprint characteristics. Pain assessment and self-reported health status in sprint athletes were examined for evaluating their common pain areas. Results: Findings from the control group, the males’ AI fell into the normal range. Yet, the females’ AI was classified as the high-arch type. AI values of the sprint group were found to be significantly lower than the control group. PPD were higher at the medial metatarsal bone of both feet and the lateral heel of the right foot in the sprint group, the males in particular, whereas lower at the medial and lateral longitudinal arches of both feet. Footprint characteristics tended to support the results of the AI and PPD, and this reflected the corresponding pressure profiles. For the sprint athletes, the lateral knee joint and biceps femoris were the most common musculoskeletal pains. Conclusions: The sprint athletes’ AI were generally classified as high arches, and that their PPD were categorized between the features of runners and high-arched runners. These findings also correspond to the profiles of patellofemoral pain syndrome (PFPS)-related plantar pressure. The pain profiles appeared to correspond to the symptoms of high-arched runners and PFPS. The findings reflected upon the possible link between high arches and PFPS. The correlation between high-arched runners and PFPS development is worth further studies.

Keywords: sprint athletes, arch index, plantar pressure distributions, high arches, patellofemoral pain syndrome

Procedia PDF Downloads 339

Authors: Rachid Belhachemi, Pierre Rostan, Alexandra Rostan

Abstract:

This paper develops a discrete-time option pricing model for index options. The model consists of two key ingredients. First, daily stock return innovations are driven by a continuous hidden threshold mixed skew-normal (HTSN) distribution which generates conditional non-normality that is needed to fit daily index return. The most important feature of the HTSN is the inclusion of a latent state variable with a continuum of states, unlike the traditional mixture distributions where the state variable is discrete with little number of states. The HTSN distribution belongs to the class of univariate probability distributions where parameters of the distribution capture the dependence between the variable of interest and the continuous latent state variable (the regime). The distribution has an interpretation in terms of a mixture distribution with time-varying mixing probabilities. It has been shown empirically that this distribution outperforms its main competitor, the mixed normal (MN) distribution, in terms of capturing the stylized facts known for stock returns, namely, volatility clustering, leverage effect, skewness, kurtosis and regime dependence. Second, heteroscedasticity in the model is captured by a threeexogenous-factor GARCH model (GARCHX), where the factors are taken from the principal components analysis of various world indices and presents an application to option pricing. The factors of the GARCHX model are extracted from a matrix of world indices applying principal component analysis (PCA). The empirically determined factors are uncorrelated and represent truly different common components driving the returns. Both factors and the eight parameters inherent to the HTSN distribution aim at capturing the impact of the state of the economy on price levels since distribution parameters have economic interpretations in terms of conditional volatilities and correlations of the returns with the hidden continuous state. The PCA identifies statistically independent factors affecting the random evolution of a given pool of assets -in our paper a pool of international stock indices- and sorting them by order of relative importance. The PCA computes a historical cross asset covariance matrix and identifies principal components representing independent factors. In our paper, factors are used to calibrate the HTSN-GARCHX model and are ultimately responsible for the nature of the distribution of random variables being generated. We benchmark our model to the MN-GARCHX model following the same PCA methodology and the standard Black-Scholes model. We show that our model outperforms the benchmark in terms of RMSE in dollar losses for put and call options, which in turn outperforms the analytical Black-Scholes by capturing the stylized facts known for index returns, namely, volatility clustering, leverage effect, skewness, kurtosis and regime dependence.

Keywords: continuous hidden threshold, factor models, GARCHX models, option pricing, risk-premium

Procedia PDF Downloads 297

Authors: Mohammad Jamalabadi, Noemi Zabari, Lukasz Bratasz

Abstract:

Panel paintings -complex multi-layer structures consisting of wood support and a paint layer composed of a preparatory layer of gesso, paints, and varnishes- are among the category of cultural objects most vulnerable to relative humidity fluctuations and frequently found in museum collections. The current environmental specifications in museums have been derived using the criterion of crack initiation in an undamaged, usually new gesso layer laid on wood. In reality, historical paintings exhibit complex crack patterns called craquelures. The present paper analyses the structural response of a paint layer with a virtual network of rectangular cracks under environmental loadings using a three-dimensional model of a panel painting. Two modes of loading are considered -one induced by one-dimensional moisture response of wood support, termed the tangential loading, and the other isotropic induced by drying shrinkage of the gesso layer. The superposition of the two modes is also analysed. The modelling showed that minimum distances between cracks parallel to the wood grain depended on the gesso stiffness under the tangential loading. In spite of a non-zero Poisson’s ratio, gesso cracks perpendicular to the wood grain could not be generated by the moisture response of wood support. The isotropic drying shrinkage of gesso produced cracks that were almost evenly spaced in both directions. The modelling results were cross-checked with crack patterns obtained on a mock-up of a panel painting exposed to a number of extreme environmental variations in an environmental chamber.

Keywords: fracture saturation, surface cracking, paintings on wood, wood panels

Procedia PDF Downloads 267

Authors: Ching-Yuan Chen, Lung-Kwang Pan

Abstract:

Objective: Back pain is a major health problem costing billions of health budgets annually in Taiwan. Thousands of back pain surgeries are performed annually with up to 40% of patients complaining of back pain at time of post-surgery causing failed back surgery syndrome (FBSS), although diagnosis in these patients may be complex. The aim of study is to assess the feasibility of using bone SPECT-CT imaging to localize the active lesions causing persistent, recurrent or new backache after spine surgery. Materials and Methods: Bone SPECT-CT imaging was performed after the intravenous injection of 20 mCi of 99mTc-MDP for all the patients with diagnosis of FBSS. Patients were evaluated using status of subjectively pain relief, functional improvement and degree of satisfaction by reviewing the medical records and questionnaires in a 2 more years’ follow-up. Results: We enrolled a total of 16 patients were surveyed in our hospital from Jan. 2015 to Dec. 2016. Four people on SPEC/CT imaging ensured significant lesions were undergone a revised surgery (surgical treatment group). The mean visual analogue scale (VAS) decreased 5.3 points and mean Oswestry disability index (ODI) improved 38 points in the surgical group. The remaining 12 on SPECT/CT imaging were diagnosed as no significant lesions then received drug treatment (medical treatment group). The mean VAS only decreased 2 .1 point and mean ODI improved 12.6 points in the medical treatment group. In the posttherapeutic evaluation, the pain of the surgical treatment group showed a satisfactory improvement. In the medical treatment group, 10 of the 12 were also satisfied with the symptom relief while the other 2 did not improve significantly. Conclusions: Findings on SPECT-CT imaging appears to be easily explained the patients' pain. We recommended that SPECT/CT imaging was a feasible and useful clinical tool to improve diagnostic confidence or specificity when evaluating patients with FBSS.

Keywords: failed back surgery syndrome, oswestry disability index, SPECT-CT imaging, 99mTc-MDP, visual analogue scale

Procedia PDF Downloads 173

Authors: Fares Elturki, Shaban Ismael Albrka Ali Zangena, H. A. M. Yahia

Abstract:

Safety is an important consideration in the design and operation of streets and highways. Traffic and highway engineers working with law enforcement officials are constantly seeking for better methods to ensure safety for motorists and pedestrians. Also, a highway safety improvement process involves planning, implementation, and evaluation. The planning process requires that engineers collect and maintain traffic safety data, identify the hazards location, conduct studies and establish project priorities. Unfortunately, in Libya, the increase in demand for private transportation in recent years, due to poor or lack of public transportation led to some traffic problems especially in the capital (Tripoli). Also, the growth of private transportation has significant influences on the society regarding road traffic accidents (RTAs). This study investigates the most critical factors affect RTAs in Tripoli the capital city of Libya. Four main classifications were chosen to build the questionnaire, namely; human factors, road factors, vehicle factors and environmental factors. Moreover, a quantitative method was used to collect the data from the field, the targeted sample size 400 respondents include; drivers, pedestrian and passengers and relative importance index (RII) were used to rank the factors of one group and between all groups. The results show that the human factors have the most significant impacts compared with other factors. Also, 84% of respondents considered the over speeding as the most significant factor cusses of RTAs while 81% considered the disobedience to driving regulations as the second most influential factor in human factors. Also, the results showed that poor brakes or brake failure factor a great impact on the RTAs among the vehicle factors with nearly 74%, while 79% categorized poor or no street lighting factor as one of the most effective factors on RTAs in road factors and third effecting factor concerning all factors. The environmental factors have the slights influences compared with other factors.

Keywords: road traffic accidents, Libya, vehicle factors, human factors, relative importance index

Procedia PDF Downloads 279

Authors: Xinxin Ma, Guangze Tang, Shuxin Yang, Jinguang He, Fan Zhang, Peiling Sun, Ming Liu, Minyu Sun, Liqin Wang

Abstract:

As a traditional surface hardening technique, shot peening is widely used in industry. By using shot peening, a residual compressive stress is formed in the surface which is beneficial for improving the fatigue life of metal materials. At the same time, very fine grains and high density defects are generated in the surface layer which enhances the surface hardness, either. However, most of the processes are carried out at room temperature. For high strength steel, such as M50, the thickness of the strengthen layer is limited. In order to obtain a thick strengthen surface layer, elevated temperature shot peening was carried out in this work by using Φ1mm cast ion balls with a speed of 80m/s. Considering the tempering temperature of M50 steel is about 550 oC, the processing temperature was in the range from 300 to 500 oC. The effect of processing temperature and processing time of shot peening on distribution of residual stress and surface hardness was investigated. As we known, the working temperature of M50 steel can be as high as 315 oC. Because the defects formed by shot peening are unstable when the working temperature goes higher, it is worthy to understand what happens during the shot peening process, and what happens when the strengthen samples were kept at a certain temperature. In our work, the shot peening time was selected from 2 to 10 min. And after the strengthening process, the samples were annealed at various temperatures from 200 to 500 oC up to 60 h. The results show that the maximum residual compressive stress is near 900 MPa. Compared with room temperature shot peening, the strengthening depth of 500 oC shot peening sample is about 2 times deep. The surface hardness increased with the processing temperature, and the saturation peening time decreases. After annealing, the residual compressive stress decreases, however, for 500 oC peening sample, even annealing at 500 oC for 20 h, the residual compressive stress is still over 600 MPa. However, it is clean to see from SEM that the grain size of surface layers is still very small.

Keywords: shot peening, M50 steel, residual compressive stress, elevated temperature

Procedia PDF Downloads 456

Authors: Fatemeh Haghiralsadat, Mohadese Hashemi, Elham Akhoundi Kharanaghi, Mojgan Yazdani, Mahboobe Sharafodini, Omid Javani

Abstract:

Niosomes are colloidal particles formed from the self-assembly of non-ionic surfactants in aqueous medium resulting in closed bilayer structures. As a consequence of this hydrophilic and hydrophobic structure, niosomes have the capacity to entrap compounds of different solubilities. Niosomes are promising vehicle for drug delivery which protect sensitive drugs and improve the therapeutic index of drugs by restricting their action to target cells. Essential oils are complex mixtures of volatile compounds such as terpenoids, phenol-derived aromatic components that have been used for many biological properties including bactericidal, fungicidal, insecticidal, antioxidant, anti-tyrosinase and other medicinal properties. Encapsulation of essential oils in niosomes can be an attractive method to overcome their limitation such as volatility, easily decomposition by heat, humidity, light, or oxygen. Cuminum cyminum L. (Cumin) is an aromatic plant included in the Apiaceae family and is used to flavor foods, added to fragrances, and for medical preparations which is indigenous to Egypt, the Mediterranean region, Iran and India. The major components of the Cumin oil were reported as cuminaldehyde, γ -terpinene, β-pinene, p-cymene, p-mentha-1, 3-dien-7-al, and p-mentha-1, 4-dien-7-al which provide the antimicrobial and antioxidant activity. The aim of this work was to formulate Cumin essential oil-loaded niosomes to improve water solubility of natural product and evaluate its physico-chemical features and stability. Cumin oil was obtained through steam distillation using a clevenger-type apparatus and GC/MS was applied to identify the main components of the essential oil. Niosomes were prepared by using thin film hydration method and nanoparticles were characterized for particle size, dispersity index, zeta potential, encapsulation efficiency, in vitro release, and morphology.

Keywords: Cuminum cyminum L., Cumin, niosome, essential oil, encapsulation

Procedia PDF Downloads 515

Authors: Mohsen Shati, Seyede Salehe Mortazavi, Seyed Kazem Malakouti, Hamidreza Khanke Fazlollah Ahmadi

Abstract:

Taking unnecessary or excessive medication or using drugs with no indication (polypharmacy) by people of all ages, especially the elderly, is associated with increased adverse drug reactions (ADR), medical errors, hospitalization and escalating the costs. It may be facilitated or impeded by the healthcare system. In this study, we are going to describe the role of the health system in the practice of polypharmacy in Iranian elderly. In this Inductive qualitative content analysis using Graneheim and Lundman methods, purposeful sample selection until saturation has been made. Participants have been selected from doctors, pharmacists, policy-makers and the elderly. A total of 25 persons (9 men and 16 women) have participated in this study. Data analysis after incorporating codes with similar characteristics revealed 14 subcategories and six main categories of the referral system, physicians’ accessibility, health data management, drug market, laws enforcement, and social protection. Some of the conditions of the healthcare system have given rise to polypharmacy in the elderly. In the absence of a comprehensive specialty and subspecialty referral system, patients may go to any physician office so may well be confused about numerous doctors' prescriptions. Electronic records not being prepared for the patients, failure to comply with laws, lack of robust enforcement for the existing laws and close surveillance are among the contributing factors. Inadequate insurance and supportive services are also evident. Age-specific care providing has not yet been institutionalized, while, inadequate specialist workforce playing a major role. So, one may not ignore the health system as contributing factor in designing effective interventions to fix the problem.

Keywords: elderly, polypharmacy, health system, qualitative study

Procedia PDF Downloads 151

Authors: Balasooriya B. M. C. M., Sujeeva N., Thowfeek Z., Siddiqa Omo, Liyanagunawardana J. E., Jayawardana Saiu, Manathunga S. S., Katulanda G. W.

Abstract:

Introduction and objectives: Adrenal venous sampling (AVS) is the gold standard to discriminate unilateral primary aldosteronism (UPA) from bilateral disease (BPA). AVS is technically demanding and only performed in a limited number of centers worldwide. To the best of our knowledge, Except for one study conducted in India, no other research studies on this area have been conducted in South Asia. This study aimed to evaluate the effectiveness of AVS in the management of primary aldosteronism. Methods: A total of 32 patients who underwent AVS at the National Hospital of Sri Lanka from April 2021 to April 2023 were enrolled. Demographic, clinical and laboratory data were obtained retrospectively. A procedure was considered successful when adequate cannulation of both adrenal veins was demonstrated. Cortisol gradient across the adrenal vein (AV) and the peripheral vein was used to establish the success of venous cannulation. Lateralization was determined by the aldosterone gradient between the two sides. Continuous and categorical variables were summarized with mean, SD, and proportions, respectively. The mean and standard deviation of the contralateral suppression index (CSI) were estimated with an intercept-only Bayesian inference model. Results: Of the 32 patients, the average age was 52.47 +26.14 and 19 (59.4%) were males. Both AVs were successfully cannulated in 12 (37.5%). Among them, lateralization was demonstrated in 11(91.7%), and one was diagnosed as a bilateral disease. There were no total failures. Right AV cannulation was unsuccessful in 18 (56.25%), of which lateralization was demonstrated in 9 (50%), and others were inconclusive. Left AV cannulation was unsuccessful only in 2 (6.25%); one was lateralized, and the other remained inconclusive. The estimated mean of the CSI was 0.33 (89% credible interval 0.11-0.86). Seven patients underwent unilateral adrenalectomy and demonstrated significant improvement in blood pressure during follow-up. Two patients await surgery. Others were treated medically. Conclusions: Despite failure due to procedural difficulties, AVS remained useful in the management of patients with PA. Moreover, the success of the procedure needs experienced hands and advanced equipment to achieve optimal outcomes in PA.

Keywords: adrenal venous sampling, lateralization, contralateral suppression index, primary aldosteronism

Procedia PDF Downloads 65

Authors: Ma. Roxanne Fernandez, Josie Athens, Balsalobre-Fernandez, Masayoshi Kubo, Kim Hébert-Losier

Abstract:

Objectives: The calf raise test (CRT) is used in rehabilitation and sports medicine to evaluate calf muscle function. For testing, individuals stand on one leg and go up on their toes and back down to volitional fatigue. The newly developed Calf Raise application (CRapp) for iOS uses computer-vision algorithms enabling objective measurement of CRT outcomes. We aimed to validate the CRapp by examining its concurrent validity and agreement levels against laboratory-based equipment and establishing its intra- and inter-rater reliability. Methods: CRT outcomes (i.e., repetitions, positive work, total height, peak height, fatigue index, and peak power) were assessed in thirteen healthy individuals (6 males, 7 females) on three occasions and both legs using the CRapp, 3D motion capture, and force plate technologies simultaneously. Data were extracted from two markers: one placed immediately below the lateral malleolus and another on the heel. Concurrent validity and agreement measures were determined using intraclass correlation coefficients (ICC₃,ₖ), typical errors expressed as coefficient of variations (CV), and Bland-Altman methods to assess biases and precision. Reliability was assessed using ICC3,1 and CV values. Results: Validity of CRapp outcomes was good to excellent across measures for both markers (mean ICC ≥0.878), with precision plots showing good agreement and precision. CV ranged from 0% (repetitions) to 33.3% (fatigue index) and were, on average better for the lateral malleolus marker. Additionally, inter- and intra-rater reliability were excellent (mean ICC ≥0.949, CV ≤5.6%). Conclusion: These results confirm the CRapp is valid and reliable within and between users for measuring CRT outcomes in healthy adults. The CRapp provides a tool to objectivise CRT outcomes in research and practice, aligning with recent advances in mobile technologies and their increased use in healthcare.

Keywords: calf raise test, mobile application, validity, reliability

Procedia PDF Downloads 166

Authors: Mani Mofidi, Neda Valizadeh, Ali Hashemaghaee, Mona Hashemaghaee, Soudabeh Shafiee Ardestani

Abstract:

Background: Acute pain and its management remained the most complaint of emergency service admission. Diagnostic and therapeutic procedures add to patients’ pain. Diminishing the pain increases the quality of patient’s feeling and improves the patient-physician relationship. Aim: The aim of this study was to evaluate the outcomes and side effects of opioid administration in emergency patients. Material and Methods: patients admitted to ward II emergency service of Imam Khomeini hospital, who received one of the opioids: morphine, pethidine, methadone or fentanyl as an analgesic were evaluated. Their vital signs and general condition were examined before and after drug injection. Also, patient’s pain experience were recorded as numerical rating score (NRS) before and after analgesic administration. Results: 268 patients were studied. 34 patients were addicted to opioid drugs. Morphine had the highest rate of prescription (86.2%), followed by pethidine (8.5%), methadone (3.3%) and fentanyl (1.68). While initial NRS did not show significant difference between addicted patients and non-addicted ones, NRS decline and its score after drug injection were significantly lower in addicted patients. All patients had slight but statistically significant lower respiratory rate, heart rate, blood pressure and O2 saturation. There was no significant difference between different kind of opioid prescription and its outcomes or side effects. Conclusion: Pain management should be always in physicians’ mind during emergency admissions. It should not be assumed that an addicted patient complaining of pain is malingering to receive drug. Titration of drug and close monitoring must be in the curriculum to prevent any hazardous side effects.

Keywords: numerical rating score, opioid, pain, emergency department

Procedia PDF Downloads 426

Authors: Patricia Portugal Marques de Carvalho Lourenco

Abstract:

A three-phase methodological multi-lingual path was designed, constructed and carried out using the 2020 Chinese Internet Drama Series We Are All Alone as a case study. Phase one, the backbone of the research, comprised of secondary data analysis, providing the structure on which the next two phases would be built on. Phase one incorporated a Google Scholar and a Baidu Index analysis, Star Network Influence Index and Mydramalist.com top two drama reviews, along with an article written about the drama and scrutiny of Chinese related blogs and websites. Phase two was field research elaborated across Latin Europe, and phase three was social media focused, having into account that perceptions are going to be memory conditioned based on past ideas recall. Overall, research has shown the poor cultural expression of Chinese entertainment in Latin Europe and demonstrated the inexistence of Chinese content in French, Italian, Portuguese and Spanish Business to Consumer retailers; a reflection of their low significance in Latin European markets and the short-life cycle of entertainment products in general, bubble-gum, disposable goods without a mid to long-term effect in consumers lives. The process of conducting comprehensive international research was complex and time-consuming, with data not always available in Mandarin, the researcher’s linguistic deficiency, limited Chinese Cultural Knowledge and cultural equivalence. Despite steps being taken to minimize the international proposed research, theoretical limitations concurrent to Latin Europe and China still occurred. Data accuracy was disputable; sampling, data collection/analysis methods are heterogeneous; ascertaining data requirements and the method of analysis to achieve a construct equivalence was challenging and morose to operationalize. Secondary data was also not often readily available in Mandarin; yet, in spite of the array of limitations, research was done, and results were produced.

Keywords: research methodologies, international research, primary data, secondary data, research limitations, online dramas, china, latin europe

Procedia PDF Downloads 68

Authors: Daniela Rimnacova, Maryna Vorokhta, Martina Svabova

Abstract:

CO₂ adsorption capacity of several materials - waste (power fly ash, slag, carbonized sewage sludge), rocks (Czech Silurian shale, black coal), and carbon (synthesized carbon, activated carbon as a reference material) - were measured on dry samples using a unique hand-made manometric sorption apparatus at a temperature of 45 °C and pressures of up to 7 MPa. The main aim was finding utilization of the waste materials and rocks for removal of the air or water pollutants caused by anthropogenic activities, as well as for the carbon dioxide storage. The equilibrium amount of the adsorbate depends on temperature, gas saturation pressure, porosity, surface area and volume of pores, and last but not least, on the composition of the adsorbents. Given experimental conditions can simulate in-situ situations in the rock bed and can be achieved just by a high-pressure apparatus. The CO₂ excess adsorption capacities ranged from 0.018 mmol/g (ash) to 13.55 mmol/g (synthesized carbon). The synthetized carbon had the highest adsorption capacity among all studied materials as well as the highest price. This material is usually used for the adsorption of specific pollutants. The excess adsorption capacity of activated carbon was 9.19 mmol/g. It is used for water and air cleaning. Ash can be used for chemisorption onto ash particle surfaces or capture of special pollutants. Shale is a potential material for enhanced gas recovery or CO₂ sequestration in-situ. Slag is a potential material for capture of gases with a possibility of the underground gas storage after the adsorption process. The carbonized sewage sludge is quite a good adsorbent for the removal and capture of pollutants, as well as shales or black coal which show an interesting relationship between the price and adsorption capacity.

Keywords: adsorption, CO₂, high pressure, porous materials

Procedia PDF Downloads 161

Authors: Chengfeng Fang, Mohamed Ali Sadakkathulla, Abdul Sheikh

Abstract:

Ultra-high-performance fiber reinforced concrete (UHPFRC) is a specially formulated cement-based composite characterized with an ultra-high compressive strength (f_c^’ = 240 MPa) and a low water-cement ratio (W/B= 0.2). With such material characteristics, UHPFRC is favored for the design and constructions of structures required high structural performance and slender geometries. Unlike conventional concrete, the structural performance of members manufactured with UHPFRC has not yet been fully studied, particularly, for UHPFRC columns with high slenderness. In this study, the behaviors of slender UHPFRC columns under concentric or eccentric load will be investigated both experimentally and numerically. Four slender UHPFRC columns were tested under eccentric loads with eccentricities, of 0 mm, 35 mm, 50 mm, and 85 mm, respectively, and one UHPFRC beam was tested under four-point bending. Finite element (FE) analysis was conducted with concrete damage plasticity (CDP) modulus to simulating the load-middle height or middle span deflection relationships and damage patterns of all UHPFRC members. Simulated results were compared against the experimental results and observation to gain the confidence of FE model, and this model was further extended to conduct parametric studies, which aim to investigate the effects of slenderness regarding failure modes and load-moment interaction relationships. Experimental results showed that the load bearing capacities of the slender columns reduced with an increase in eccentricity. Comparisons between load-middle height and middle span deflection relationships as well as damage patterns of all UHPFRC members obtained both experimentally and numerically demonstrated high accuracy of the FE simulations. Based on the available FE model, the following parametric study indicated that a further increase in the slenderness of column resulted in significant decreases in the load-bearing capacities, ductility index, and flexural bending capacities.

Keywords: eccentric loads, ductility index, RC column, slenderness, UHPFRC

Procedia PDF Downloads 130

Authors: Ahmadi, Iriansyah, Raihana Yahman

Abstract:

The giant freshwater prawn (Macrobrachium rosenbergii de Man, 1879) is a valuable species for fisheries and aquaculture, especially in Southeast Asia, including Indonesia due to their high market demand and potential for export. The growing demand for prawns is straining the sustainability of the Banjar Regency fishery. To ensure the long-term sustainability and economic viability of the prawn fishing in this region, it is imperative to implement evidence-based management practices. This requires comprehensive data on the Catch per Unit Effort (CPUE), Maximum Sustainable Yield (MSY) and the current rate of prawn resource exploitation. it analyzed five years of prawn catch data (2019-2023) obtained from South Kalimantan Marine and Fisheries Services. Fishing gears (e.g. hook & line and cast net) were first standardized with Fishing Power Index, and then calculated effort and MSY. The intercept (a) and the slope (b) values of regression curve were used to estimate the catch-maximum sustainable yield (CMSY) and optimal fishing effort (Fopt) levels within the framework of the Surplus Production Model. The estimated rates of resource utilization were then compared to the criteria of The National Commission of Marine Fish Stock Assessment. The findings showed that the CPUE value peaked in 2019 at 33.48 kg/trip, while the lowest value observed in 2022 at 5.12 kg/trip. The CMSY value was estimated to be 17,396 kg/year, corresponding to the Fopt level of 1,636 trips/year. The highest utilization rate was 56.90% recorded in 2020, while the lowest rate was observed in 2021 at 46.16%. The annual utilization rates were classified as “medium”, suggesting that increasing fishing effort by 45% could potentially maximize prawn catches at an optimum level. These findings provide a baseline for sustainable fisheries management in the region.

Keywords: giant prawns, CPUE, fishing power index, sustainable potential, utilization rate

Procedia PDF Downloads 16