bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of Physiological Traits Vulnerability in Determine Halophytes Tolerance to Salinity Excess: A Comparative Assessment in Atriplex halimus
Authors: Pérez-Romero Jesús Alberto , Mateos-Naranjo Enrique , López-Jurado Javier , Redondo-Gómez Susana , Torres-Ruiz José M.
Published: May 2020

Many halophytic physiological traits related to the tolerance of plants to salinity excess have been extensively studied, with a focus on biomass and/or gas exchange parameters. To gain a more complete understanding of whether salinity excess affects the physiological performance of halophytes, an experiment was performed using the halophyte Atriplex halimus L. as a model. A. halimus plants were subjected to two salinity treatments (171 and 513 mM NaCl) over 60 days in a controlled environment. After this period, dry biomass, specific stem conductivity, water potential at turgor loss point, osmotic potential, gas exchange parameters, and the fluorescence of chlorophyll a derived parameters were assessed in order to obtain knowledge about the differences in vulnerability that these parameters can show when subjected to salinity stress. Our results showed a decrease in belowground and aboveground biomass. The decrement in biomass seen at 513 mM NaCl was related to photosynthetic limitations and specific stem conductivity. Turgor loss point did not vary significantly with the increment of salinity. Therefore, the parameter that showed less vulnerability to saline stress was the turgor loss point, with only a 5% decrease, and the more vulnerable trait was the stem conductivity, with a reduction of nearly 50%.
Electrically Conductive Nanocomposites Composed of Styrene–Acrylonitrile Copolymer and rGO via Free-Radical Polymerization
Authors: Ko Eun Bin , Lee Dong-Eun , Yoon Keun-Byoung
Published: May 2020

The polymerizable reduced graphene oxide (mRGO) grafted styrene–acrylonitrile copolymer composites were prepared via free radical polymerization. The graphene oxide (GO) and reduced graphene oxide (rGO) was reacted with 3-(tri-methoxysilyl)propylmethacrylate (MPS) and used as monomer to graft styrene and acrylonitrile on its surface. The successful modification and reduction of GO was confirmed using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), Raman and X-ray diffraction (XRD). The mRGO was prepared using chemical and solvothermal reduction methods. The effect of the reduction method on the composite properties and nanosheet distribution in the polymer matrix was studied. The thermal stability, electrical conductivity and morphology of nanocomposites were studied. The electrical conductivity of the obtained nanocomposite was very high at 0.7 S/m. This facile free radical polymerization provides a convenient route to achieve excellent dispersion and electrically conductive polymers.
Influence of Polymer Composites and Memory Foam on Energy Absorption in Vehicle Application
Authors: Pilipović Ana , Ilinčić Petar , Petruša Jelena , Domitran Zoran
Published: May 2020

The automotive industry is one of the biggest consumers of polymer composites. Aside from good mechanical properties, polymer composites have low mass, which positively affects the overall vehicle weight reduction and improves energy efficiency. Although polymer composites are used in various vehicle components, this paper focused on the application in vehicle bumper production. Two different composite plates with hybrid fiber layup were made; the first plate with a combination of glass and carbon fibers and the second with carbon and aramid. For comparison, and as a cheaper variant, a third plate was made only with glass fibers. In the first two plates, epoxy resin was used as the matrix, while in the third plate, polyester resin was used. Polyurethane memory foams of different densities (60, 80, 100 kg/m3) and thicknesses (10, 15, 20 mm) were used as impact force energy absorbers. With the factorial design of experiments, it was found that the thickness of the memory foam was the main influence factor. Without the use of memory foam, the hybrid composite, made of glass and carbon fibers, showed the highest energy absorption, while with the use of foam, the highest energy absorption was achieved with the glass fiber composite. Without the memory foam, the impact force measured on the glass/carbon hybrid composite was 9319.11 ± 93.18 N. Minimum impact force to the amount of 5143.19 ± 237.65 N was measured when the glass fiber composite plate was combined with the memory foam. When using memory foam, the impact force was reduced by 30–48%, depending on the type of composite used.
Experimental Investigation of the Melt Shear Viscosity, Specific Volume and Thermal Conductivity of Low-Density Polyethylene/Multi-Walled Carbon Nanotube Composites Using Capillary Flow
Authors: Stanciu Nicoleta-Violeta , Stan Felicia , Fetecau Catalin
Published: May 2020

Understanding the flow behavior of polymer/carbon nanotube composites prior to melt processing is important for optimizing the processing conditions and final product properties. In this study, the melt shear viscosity, specific volume and thermal conductivity of low-density polyethylene (LDPE) filled with multi-walled carbon nanotubes (MWCNTs) were investigated for representative processing conditions using capillary rheometry. The experimental results show a significant increase in the melt shear viscosity of the LDPE/MWCNT composite with nanotube loadings higher than 1 wt.%. Upon increasing shear rates, the composites flow like a power-law fluid, with a shear-thinning index less than 0.4. The specific volume decreases with increasing pressure and nanotube loading, while the pVT transition temperature increases linearly with increasing pressure. The thermal conductivity of the LDPE/MWCNT composite is nearly independent of nanotube loading up to the thermal percolation threshold of 1 wt.% and increases linearly with further increases in nanotube loading, reaching 0.35 W/m·K at 5 wt.%. The Carreau–Winter and Cross viscosity models and Tait equation, respectively, are able to predict the shear viscosity and specific volume with a high level of accuracy. These results can be used not only to optimize processing conditions through simulation but also to establish structure–property relationships for the LDPE/MWCNT composites.
The Effect of Temperature on the Biosorption of Dyes from Aqueous Solutions
Authors: Smoczyński Lech , Pierożyński Bogusław , Mikołajczyk Tomasz
Published: May 2020

This work is a review of scientific papers on the influence of temperature (T) on the biosorption of various dyes from aqueous solutions and wastewaters. The dyeing process of textiles is usually carried out at high temperatures, and therefore, the wastewater generated there when entering the treatment plant may still be hot. Hence, depending on the climatic conditions of a given region, the biosorption method used for their purification may occur at various temperatures. Most of the papers clearly stated the positive influence of T on biosorption, generally indicating the chemical nature of this process. At the same time, substantial number of authors confirmed the positive effect of T on the biosorption with an initial T-rise from approximately 20 °C to about 30–40 °C range; conversely, at higher temperatures, they indicated a decrease in the biosorption efficiency. Additionally, many authors clearly implied the negative impact of T on the biosorption parameters. They generally envisaged the physical nature of this process, but also indicated its limitation, as there was only a 15%–50% reduction in biosorption efficiency with an increase in T. In addition, an attempt was made to analyse the effect of temperature on the biosorption process, depending on the type of dye. It could then be cautiously suggested that a moderate increase in the T parameter favourably affected the biosorption of the red and reactive dyes.
A Reliable Automated Sampling System for On-Line and Real-Time Monitoring of CHO Cultures
Authors: Hofer Alexandra , Kroll Paul , Barmettler Matthias , Herwig Christoph
Published: May 2020

Timely monitoring and control of critical process parameters and product attributes are still the basic tasks in bioprocess development. The current trend of automation and digitization in bioprocess technology targets an improvement of these tasks by reducing human error and increasing through-put. The gaps in such automation procedures are still the sampling procedure, sample preparation, sample transfer to analyzers, and the alignment of process and sample data. In this study, an automated sampling system and the respective data management software were evaluated for system performance; applicability with HPLC for measurement of vitamins, product and amino acids; and applicability with a biochemical analyzer. The focus was especially directed towards the adaptation and assessment of an appropriate amino acid method, as these substances are critical in cell culture processes. Application of automated sampling in a CHO fed-batch revealed its potential with regard to data evaluation. The higher sampling frequency compared to manual sampling increases the generated information content, which allows easier interpretation of the metabolism, extraction of e.g., ks values, application of smoothing algorithms, and more accurate detection of process events. A comparison with sensor technology shows the advantages and disadvantages in terms of measurement errors and measurement frequency.
Molecular Interpretation of Pharmaceuticals’ Adsorption on Carbon Nanomaterials: Theory Meets Experiments
Authors: Veclani Daniele , Tolazzi Marilena , Melchior Andrea
Published: May 2020

The ability of carbon-based nanomaterials (CNM) to interact with a variety of pharmaceutical drugs can be exploited in many applications. In particular, they have been studied both as carriers for in vivo drug delivery and as sorbents for the treatment of water polluted by pharmaceuticals. In recent years, the large number of experimental studies was also assisted by computational work as a tool to provide understanding at molecular level of structural and thermodynamic aspects of adsorption processes. Quantum mechanical methods, especially based on density functional theory (DFT) and classical molecular dynamics (MD) simulations were mainly applied to study adsorption/release of various drugs. This review aims to compare results obtained by theory and experiments, focusing on the adsorption of three classes of compounds: (i) simple organic model molecules; (ii) antimicrobials; (iii) cytostatics. Generally, a good agreement between experimental data (e.g. energies of adsorption, spectroscopic properties, adsorption isotherms, type of interactions, emerged from this review) and theoretical results can be reached, provided that a selection of the correct level of theory is performed. Computational studies are shown to be a valuable tool for investigating such systems and ultimately provide useful insights to guide CNMs materials development and design.
Key Challenges in Designing CHO Chassis Platforms
Authors: Hamdi Anis , Széliová Diana , Ruckerbauer David E. , Rocha Isabel , Borth Nicole , Zanghellini Jürgen
Published: May 2020

Following the success of and the high demand for recombinant protein-based therapeutics during the last 25 years, the pharmaceutical industry has invested significantly in the development of novel treatments based on biologics. Mammalian cells are the major production systems for these complex biopharmaceuticals, with Chinese hamster ovary (CHO) cell lines as the most important players. Over the years, various engineering strategies and modeling approaches have been used to improve microbial production platforms, such as bacteria and yeasts, as well as to create pre-optimized chassis host strains. However, the complexity of mammalian cells curtailed the optimization of these host cells by metabolic engineering. Most of the improvements of titer and productivity were achieved by media optimization and large-scale screening of producer clones. The advances made in recent years now open the door to again consider the potential application of systems biology approaches and metabolic engineering also to CHO. The availability of a reference genome sequence, genome-scale metabolic models and the growing number of various “omics” datasets can help overcome the complexity of CHO cells and support design strategies to boost their production performance. Modular design approaches applied to engineer industrially relevant cell lines have evolved to reduce the time and effort needed for the generation of new producer cells and to allow the achievement of desired product titers and quality. Nevertheless, important steps to enable the design of a chassis platform similar to those in use in the microbial world are still missing. In this review, we highlight the importance of mammalian cellular platforms for the production of biopharmaceuticals and compare them to microbial platforms, with an emphasis on describing novel approaches and discussing still open questions that need to be resolved to reach the objective of designing enhanced modular chassis CHO cell lines.
Strain and Temperature Sensitivities Along with Mechanical Properties of CNT Buckypaper Sensors
Authors: Her Shiuh-Chuan , Hsu Wei-Chun
Published: May 2020

In this work, buckypaper composed of multi-walled carbon nanotubes (MWCNT) was prepared through a vacuum filtration process. The effect of MWCNT aspect ratio on the buckypaper performance was investigated. The freestanding and highly flexible buckypaper can be used as a sensor to attach on a complex surface monitoring the strain and temperature at the critical area. The mechanical properties of the buckypaper were examined using the tensile and nanoindentation tests. The strain and temperature sensitivities of the buckypaper were evaluated through the four-point bending and thermal chamber tests, respectively. In addition, the microstructure and thermal stability of the buckypaper were studied by scanning electron microscopy (SEM) and thermogravimetric analyzer (TGA), respectively. Experimental results showed that the mechanical properties such as Young’s modulus, tensile strength, fracture strain, and hardness of the buckypaper made of high aspect ratio MWCNTs were significantly superior to the buckypaper consisted of low aspect ratio MWCNTs, while the strain and temperature sensitivities of the buckypaper composed of low aspect ratio MWCNTs were better than that of the buckypaper made of high aspect ratio MWCNTs.
Identifying Groundwater and River Water Interconnections Using Hydrochemistry, Stable Isotopes, and Statistical Methods in Hanumante River, Kathmandu Valley, Central Nepal
Authors: Bajracharya Ramita , Nakamura Takashi , Ghimire Subesh , Man Shakya Bijay , Kazi Tamrakar Naresh
Published: May 2020

Interconnection between river water and groundwater plays an important role in maintaining water quantity and quality in hydrological systems. Furthermore, the exact interconnection is often difficult to observe and measure. This study attempts to explain river and shallow groundwater interconnection in urbanized areas of the Kathmandu Valley, Nepal. Isotopic (δD and δ18O) and chemical analyses were performed on river and groundwater samples, and the results were analyzed using statistical methods to identify areas of interconnection between river water and groundwater. Higher concentrations and positive strong correlations of Na+ with K+, NH4+-N, Cl−, HCO3−, and PO4−-P, and a change of water type from Ca-HCO3 during the wet season to Na-K-HCO3 during the dry season indicate higher contamination in river water during the dry season. Hierarchical cluster analysis was used in grouping water samples into clusters on the basis of isotopic and chemical (Na+ and Cl−) composition. Grouping of river and groundwater samples in one–one clusters from wet and dry seasons shows the presence of interconnection, indicating the contribution of river water in recharging shallow groundwater. These results imply that shallow groundwater found near rivers is chemically contaminated by polluted river water through bank infiltration, in both wet and dry seasons.
A Method to Improve the Flood Maps Forecasted by On-Line Use of 1D Model
Authors: Filianoti Pasquale G. F. , Nicotra Angelo , Labate Antonino , Zema Demetrio A.
Published: May 2020

Forecasting floods in urban areas during a heavy rainfall is the aim of every early warning system. 2D-models produce the most accurate flood maps, but they are practically useless as quasi real-time tools, because their run times are comparable to times of propagation of floods. Run times of 1D-model are of tens of seconds, but their predictions lack accuracy and many useful indicators of flood severity. Our aim is the identification of the 2D-model map that is more similar to the actual map, chosen among those simulated off-line. To this aim, we produce a rough flood map of the occurring event, through a quasi real-time simulation of the rainfall-runoff using a 1D-model. Then we apply an original method, named “ranking approach”, to perform the best matching. This method is applied to the Corace torrent (Calabria, Southern Italy), using 17 synthetic hyetographs to simulate the same number of rainfall-runoff events, using 1D (SWMM) and 2D (MIKE) models. The method proves to be effective in 65% of the cases, while in 82% of cases (i.e., for 14 cases out 17), the event produced by the same ietograph falls within the third rank.
Connectivity of Ephemeral and Intermittent Streams in a Subtropical Atlantic Forest Headwater Catchment
Authors: Perez Alondra B. A. , Innocente dos Santos Camyla , Sá João H. M. , Arienti Pedro F. , Chaffe Pedro L. B.
Published: May 2020

Stream network extension and contraction depend on landscape features and the characteristics of precipitation events. Although this dependency is widely recognized, the interaction among overland-flow generation processes, drainage active length, and frequency in temporary streams remains less understood. We studied a forest headwater catchment with wide variation in soil depth to investigate the runoff generation processes that lead to the occurrence of ephemeral and intermittent flow and connectivity between hillslope and outlet. We used low-cost equipment to monitor the variation in the length of the active drainage network and to measure the water table development. The flow in the channels can develop even under light rainfall conditions, while the connectivity is controlled by antecedent wetness, total precipitation, and active contribution area thresholds. Runoff permanence and fragmentation were related to soil depth variation; flow being usually more disconnected due to deeper water tables in deeper soil locations. Our findings emphasized the impact of soil structure on runoff generation in hillslopes and can be useful in the management of the most active areas and their impact on the quality of available water.
Nitrogen and Phosphorus Loads in Greek Rivers: Implications for Management in Compliance with the Water Framework Directive
Authors: Stefanidis Konstantinos , Christopoulou Aikaterini , Poulos Serafeim , Dassenakis Emmanouil , Dimitriou Elias
Published: May 2020

Reduction of nutrient loadings is often prioritized among other management measures for improving the water quality of freshwaters within the catchment. However, urban point sources and agriculture still thrive as the main drivers of nitrogen and phosphorus pollution in European rivers. With this article we present a nationwide assessment of nitrogen and phosphorus loads that 18 large rivers in Greece receive with the purpose to assess variability among seasons, catchments, and river types and distinguish relationships between loads and land uses of the catchment. We employed an extensive dataset of 636 field measurements of nutrient concentrations and river discharges to calculate nitrogen and phosphorus loads. Descriptive statistics and a cluster analysis were conducted to identify commonalties and differences among catchments and seasons. In addition a network analysis was conducted and its modularity feature was used to detect commonalities among rivers and sampling sites with regard to their nutrient loads. A correlation analysis was used to identify major possible connections between types of land uses and nutrient loads. The results indicated that the rivers Alfeios, Strymonas, and Aliakmonas receive the highest inorganic nitrogen loads while the highest inorganic phosphorus loads were calculated for the rivers Strymonas, Aliakmonas, and Axios. Concerning the temporal variation of loads, inorganic nitrogen presented a peak on March and gradually declined until October when the dry period typically ends for most regions of Greece. Inorganic phosphorus loads had the highest average value in August and the lowest in October. Thus, our findings confirmed the presence of a typical seasonal variation in nitrogen loads that follows the seasonality in hydrology where high surface runoff during the wet months contribute to higher river discharges and higher nitrogen loads from the catchment. On the contrary, high phosphorus loads persisted during dry months that could be attributed to a dilution effect. Furthermore, the results imply a clear connection between agriculture and both nitrogen and phosphorus. Overall, this work presents extensive information on the nitrogen and phosphorus loads that major rivers in Greece receive that can largely aid water managers to adapt and revise basin management plans in accordance with agricultural management (e.g., which months farmers should reduce the use of fertilizers) with the purpose of meeting the environmental targets defined by the Water Framework Directive (WFD).
Challenges and Opportunities for Sustainable Management of Water Resources in the Island of Crete, Greece
Authors: Tzanakakis V. , Angelakis A. , Paranychianakis N. , Dialynas Y. , Tchobanoglous G.
Published: May 2020

Crete, located in the South Mediterranean Sea, is characterized by long coastal areas, varied terrain relief and geology, and great spatial and inter-annual variations in precipitation. Under average meteorological conditions, the island is water-sufficient (967 mm precipitation; theoretical water potential 3425.89 hm3; and total water use 610 hm3). Agriculture is by far the greatest user of water (78% of total water use), followed by domestic use (21%). Despite the high average water availability, water scarcity events commonly occur, particularly in the eastern-south part of the island, driven by local climatic conditions and seasonal or geographical mismatches between water availability and demand. Other critical issues in water management include the over-exploitation of groundwater, accounting for 93% of the water used in agriculture; low water use efficiencies in the farms; limited use of non-conventional water sources (effluent reuse); lack of modern frameworks of control and monitoring; and inadequate cooperation among stakeholders. These deficiencies impact adversely water use efficiency, deteriorate quality of water resources, increase competition for water and water pricing, and impair agriculture and environment. Moreover, the water-limited areas may display low adaptation potential to climate variability and face increased risks for the human-managed and natural ecosystems. The development of appropriate water governance frameworks that promote the development of integrated water management plans and allow concurrently flexibility to account for local differentiations in social-economic favors is urgently needed to achieve efficient water management and to improve the adaptation to the changing climatic conditions. Specific corrective actions may include use of alternative water sources (e.g., treated effluent and brackish water), implementation of efficient water use practices, re-formation of pricing policy, efficient control and monitoring, and investment in research and innovation to support the above actions. It is necessary to strengthen the links across stakeholders (e.g., farmers, enterprises, corporations, institutes, universities, agencies, and public authorities), along with an effective and updated governance framework to address the critical issues in water management, facilitate knowledge transfer, and promote the efficient use of non-conventional water resources.
Use of Machine Learning in Evaluation of Drought Perception in Irrigated Agriculture: The Case of an Irrigated Perimeter in Brazil
Authors: Xavier Louise Caroline Peixoto , Silva Samiria Maria Oliveira da , Carvalho Taís Maria Nunes , Pontes Filho João Dehon , Souza Filho Francisco de Assis de
Published: May 2020

This study aimed to understand the perception of drought among farmers, in order to support decision-making in the water allocation process. This study was carried out in the Tabuleiro de Russas irrigated perimeter, in northeast Brazil, over the drought period of 2012–2018. Two analyses were conducted: (i) drought characterization, using the Standardized Precipitation Index (SPI) based on drought duration and frequency criteria; and (ii) analysis of farmers’ perceptions of drought via selection of explanatory variables using the Random Forest (RF) and the Decision Tree (DT) methods. The 2012–2018 drought period was defined as a meteorological phenomenon by local farmers; however, an SPI evaluation indicated that the drought was of a hydrological nature. According to the RF analysis, four of the nine study variables were more statistically important than the others in influencing farmers’ perception of drought: number of cultivated land plots, farmer’s age, years of experience in the agriculture sector, and education level. These results were confirmed using DT analysis. Understanding the relationship between these variables and farmers’ perception of drought could aid in the development of an adaptation strategy to water deficit scenarios. Farmers’ perception can be beneficial in reducing conflicts, adopting proactive management practices, and developing a holistic and efficient early warning drought system.
Productivity Analysis of Front-end Loader in Timber Harvesting
Authors: AKAY Abdullah Emin , BİLİCİ Ebru , TAŞ İnanç , FINDIK Hüseyin
Published: May 2020

In this study, the productivity of front-end loader (Liebherr L 514 Stereo), which is one of the most used mechanized harvesting equipment in the production of forest products, was analyzed using time-study method. Factors influencing loader productivity were also evaluated by statistical analysis. Time measurements were carried out during forest harvesting operations in Topçam Forest Enterprise Chief in the city of Giresun. The results indicated that the most time-consuming stage of the loading operation was moving loaded to the logging truck, followed by moving unloaded to the side of the logs. According to the results, the average productivity of the loader was 34.27 m3/hr. Correlation test results showed that there was a positive correlation between productivity and log diameter and log volume, while there was no significant relationship between productivity and log length. The regression model developed with respect to the loader's productivity and specified log parameters (i.e. log diameter and log volume) was found to be significant and adequately explained the productivity of the loader. It was found that there was a significant relation between loader productivity and diameter classes and volume classes. It was also found that loader productivity increased as log diameter and log volume increases.
MATERIAL COMPOSITION OF CLAY FROM THE AL-NAJAF FIELD (IRAQ)
Authors: Vezentsev A. , Volovicheva N. , Korolkova S. , Al-Ateya A. T. A.
Published: May 2020

A comprehensive study of the material composition of clay raw materials of the al-Najaf field (Iraq), which belongs to the sedimentary deposits of the Dammam formation, is conducted. The features of the chemical and phase composition of the rock are determined using x-ray phase, energy dispersive, microrentgenospectral, electron microscopic and thermogravimetric methods of analysis. The presence of titanium as an impurity element is detected in the studied clay along with the typical element composition of aluminosilicates using energy-dispersion-spectral analysis. At the same time, a high total content of oxides of alkaline and alkaline earth metals (Cao, Na2O, K2O) is recorded, amounting to more than 5.0 wt. %. It is found that the sample under study has a polymineral composition, the main rock-forming minerals are kaolinite, illite and montmorillonite. The total percentage of the clay component is more than 82 wt.%. Content of clay particles belonging to high-and medium-dispersed fractions (size 10 microns or less) it is more than 60% by weight. The average size of the particles composing the studied clay is about 32.0 microns. Based on the data on the chemical, mineralogical and granulometric composition of the sample, a conclusion is made about the potential suitability of the studied clay as a sorption-active material, as well as in the production of Portland cement and coarse ceramics.
LA FORMACIÓN DE ACTITUD CIENTÍFICA DESDE LA CLASE DE CIENCIAS NATURALES
Authors: Calderón Polanía Yeny
Published: May 2020

Esta investigación busca contribuir a formar una actitud científica en los estudiantes a partir de la enseñanza de las ciencias, y a través de dos interesantes enfoques de la didáctica contemporánea El aprendizaje basado en problemas (PBL) y la Problematizadora didáctica. La actitud científica en esta propuesta se considera una alternativa para acercar al estudiante al conocimiento científico. La investigación busca formular una propuesta didáctica que permita contribuir a generar una inclinación favorable al conocimiento y la investigación científica en la población de estudiantes de grado 10 y 11, de la Institución Educativa Nacional Dante Alighieri de San Vicente del Caguán. En la misma línea La propuesta busca determinar acciones a medio llenar que utilicen el nuevo enfoque didáctico Problemas de Aprendizaje Basado (PBL) y la implementación de prácticas de corte experimental (prácticas de laboratorio), apoyadas en procesos cognitivos. Para llevar a cabo esta propuesta es necesario investigar los aspectos importantes del proceso en la enseñanza de Ciencias Naturales en la escuela intermedia y secundaria. Las últimas tendencias educativas relacionadas con el problema básico de aprendizaje y enseñanza (PBLT), y las experiencias en el laboratorio teniendo en cuenta las estrategias metacognitivas. En consecuencia, la intervención didáctica de esta propuesta pretende generar actitudes científicas en los alumnos. Alentará a los estudiantes a producir nuevas formas de conocimiento a partir de la investigación, el descubrimiento y la crítica en el aula.
STUDY ON PRE-HYPERTENSION PREVALENCE AND RELATIONSHIP WITH DYSLIPIDEMIA IN ADULTS AT QUANG NAM PROVINCE
Authors: To Muoi , Hoang Khanh , Huynh Van Minh
Published: May 2020

Objectives: To investigate the prevalence, risk factors of prehypertension in QuangNam province of Vietnam.

Methods: A case-control study of 3.237 adults (aged ≥ 25 years) was conducted in Quang Nam province, Vietnam in 2017, using questionnaire interviews, clinical examinations, and laboratory tests. Blood pressure, anthropometry, plasma glucose and lipids were measured. The variables contributing significantly to pre-hypertension were analyzed by multiple logistic regression analysis.

Results: The prevalence of prehypertension, hypertension and normal blood pressure was 30.7%, 31.6% and 37.7%, respectively. Cardiovascular risk factors such as overweight and obesity, family history of hypertension, alcohol abuse, smoking, diabetes, high total cholesterol levels, high triglyceride levels, high LDL-C levels were significantly greater in prehypertensive compared to optimal blood pressure (BP). Multivariable logistic regression analysis revealed strong positive associations of pre-hypertension with alcohol abuse (OR = 1.68; CI 95%: 1.29-2.20; p < 0.001), diabetes (OR = 3.39; CI 95%: 1.32 - 8.65; p=0.011); high triglyceride levels (OR = 1.41, CI 95%: 1.13 - 1.75, p = 0.002); high LDL-C levels (OR = 1.42; CI 95%: 1.03 - 1.97; p=0.034). There was a positive correlation of cardiovascular risk factors such as BMI, abdominal circumference, blood glucose, blood cholesterol, blood triglyceride, blood LDL-C with changes in systolic BP, diastolic BP, and average BP.

Conclusions: The prevalence of prehypertension in Quang Nam province of Vietnam was 30.7%. Risk factors such as alcohol abuse, diabetes, high triglycerides, high LDL-C were significantly associated with prehypertension.

Key words: cardiovascular risk factors - hypertension – prehypertension
A Study on Generalized Jacobsthal-Padovan Numbers
Authors: Soykan Yüksel
Published: May 2020

In this paper, we investigate the generalized Jacobsthal-Padovan sequences and we deal with, in detail, four special cases, namely, Jacobsthal-Padovan, Jacobsthal-Perrin, adjusted Jacobsthal-Padovan and modified Jacobsthal-Padovan sequences. We present Binet’s formulas, generating functions, Simson formulas, and the summation formulas for these sequences. Moreover, we give some identities and matrices related with these sequences.
Optimized Energy Utilization and Performance Evaluation of an Oil Filling Station in Dubai
Authors: Damodaran Sreejith
Published: May 2020

This study focuses on the optimized energy conservation in commercial infrastructure and filling station in Dubai without affecting its function and the customers. This method involves the installation of automatic thermostats, dynamic lighting controls and solar panels. The proposed technique covers the HVAC system and lighting system of the infrastructure which need considerable amount of investment which can give full returns in 4 year of performance, and energy conservation is guaranteed in 6 years. The corresponding design and result analysis are clearly discussed in this article and the energy comparison study has proved the effectiveness of the proposed techniques.
Experimental Investigation of Various Shell Footings in Cohesive and Cohesionless Soil
Authors: M Kumar , M Subagiriraj
Published: May 2020

The increasing demand of infrastructure development leads to the usage of sandy soils; which possess low bearing capacity. In this regard, this study is to provide a novel solution to counteract the problems faced by the weak soil. The experimental study was carried out on both Flat and Shell models with the corresponding Triangular, Square and Hexagon shapes for both loose and medium dense condition. The models were compared based on their equal plan area. To carry out the experimental work, a model tank of cylindrical shape of dimensions of 50cm diameter and 50 cm height is used. Vertical load were applied to the models and the corresponding settlement were observed. The ultimate load carrying capacity of footing models was calculated and plotted by the load versus settlement graph. From the results, Improvement factor on vertical load carrying of Flat Square footing is 1.75 on loose sand. In dense sand the improvement factor of Flat Square is 1.67. The efficiency of pyramidal shell is 75% and 66.7% on counter flat footing on loose sand and dense sand condition respectively. The settlement characteristic of triangular shell is better than other models on both loose and medium dense conditions. The load carrying capacity and efficiency of square footing having more value among other footing models for both low and medium consistency of clay. In sand the efficiency of shell is greater than in clayey soil, so the shell footings performing better way in sandy soil.
Assessment of Radon in groundwater and associated human risk from Sankarabarani River Sub Basin, Southern India
Authors: R Rajesh Kanna , K Srinivasamoorthy , G Ponnumani , S Gopinath , R Prakash
Published: May 2020

Radon (222Rn) and associated human risk assessment in groundwater from quaternary shallow aquifers of Sankarabarani River sub basin, Southern India has been attempted by considering 41 groundwater samples and analysed for 222Rn using scintillation Radon monitoring system. The Radon ranges between 0.140±0.01 Bq l-1 to 7.869±0.33 Bq l-1 with an average of 1.797±0.12Bq l-1 and found to be within the maximum contamination level of Environmental Protection Agency (11.1 Bq l-1). The doses of ingestion and inhalation calculated for radon varies between 0.709 µSv y-1 to 39.933µSv y-1 with an average of 9.121µSv y-1which is within the prescribed dose limit of 100µSv y-1 by World Health Organisation. Uranium speciation attempted suggests saturated Haiweeite and Soddyite as sources for uranium/radon into the aquifer systems. The Eh-pH diagram suggests uraninite solubility within the pH ranges 6 to 8 within the groundwater environment.
Strain Pattern Analysis of Mylonites From Sitampundi-Kanjamalai Shear Zone, Thiruchengode, South India
Authors: V Thirukumaran , T.K Biswal , K Sundaralingam , V Sowmya , S Boopathi , R Mythili
Published: May 2020

This study aims to investigate the petrography and strain pattern of mylonites from parts of N-S trending Sitampundi-Kanjamalai Shear Zone (SKSZ) around Thiruchengode. The petrographic study indicates the presence of recrystallized quartz, K-feldspar, plagioclase, biotite and some hornblende. The kinematic analysis of Mylonites was done with the help of shear sense indicators such as recrystallized type quartz (quartz ribbon) around the cluster of feldspar, S-C fabric shows dextral shear sense and some sinisterly shear sense in some parts of SASZ which can be considered as a product of partitioning of both strain and vorticity between domains. These all indicates the simple shear extension along E-W direction and the mylonitic foliation shows the pure shear compression along N-S direction. Further the study of bulk strain analysis by Flinn plot method using L and T section of mylonite shows k<1 which lies in the field of flattening zone of finite strain. The kinematic vorticity number is calculated by Rxz/β method which gives the value of 0.36 indicating the general shear. The rigid grain graph shows that the pure shear component is more ­­­­dominant than the simple shear component. The analysis leads to the conclusion that the mylonite has experienced a high temperature shearing of above 700°cat deep crustal level.
Rainfall Uncertainty and Drought Proofing Strategies by farmers in Southern India
Authors: K Palanisami , D Suresh Kumar , T Mohanasundari
Published: May 2020

Droughts are a common occurrence in semi-arid areas and their frequency and intensity is expected to increase further with increasing variability in rainfall distribution. Based on a study of 120 farmers from 4 districts in Karnataka and Tamil Nadu, this paper identified the range of measures farmers adopt in response to droughts. Despite significant negative externalities, farmers assign higher priority to drilling new wells rather than investing in water conservation structures or demand management strategies. Among the different strategies followed, adoption of drip irrigation and purchase of tanker water for providing life-saving irrigation to perennial crops yield the highest financial return. Expansion of micro irrigation and reuse of municipal waste water are suggested as drought mitigation strategies.
Detailed Study on Critical Delay Factors Affecting the Construction Industry
Authors: K.L. Ravisankar , T Bragateeswaran
Published: May 2020

The Construction industry of India is an important indicator of the growth as it generates investment opportunities across various related sectors. Delay in construction projects is considered one of the most common problems causing a multitude of negative effects on the construction projects. Construction delays can be defined as the late completion of work compared to the planned schedule or contract schedule. Construction delays can be minimized only when their cause are identified. The objective of this study was to identify the major causes of construction delays. In this context the management of the delay may influence the financial performance of the project, since the overall value of contractual penalties may exceed ten percentage or more than that of the project budget.

This study was carried out based on literature review and a questionnaire survey. The data for this study will be gathering through a detailed questionnaire survey. The questionnaire consists of total factors of seventeen group were contributed to the causes of construction delay based on literature review. In that seventeen groups have been consist of total 50 factors for delay. The questionnaire form is forwarded to various construction industries through email and in personal. The objectives of the study were successfully achieved. The top five most important factors that contributed to the causes of delays were Delay in financial support by owner to the contractor (Stage by stage payment), Design errors made by designers due to unfamiliarity with local conditions & environment, Equipment allocation problem, Poor site management & Inaccurate site investigation, Fluctuation of prices. To minimize delay in construction projects it has been identified that the top three effective methods of minimizing construction delays includes: site management and supervision, effective strategic planning, and clear information and communication channels.
Vibration Control Of Steel Frames Using Magnetorheological Dampers: A New Control Algorithm.
Authors: G.K. Arunvivek , R Saravanakumar
Published: May 2020

Control technologies application to steel structure is mainly anticipated to enhance the structural performance against natural hazards. In particular smart base isolation system connected with semi-active isolator at the base with controllable semi devices gaining impulse for its efficiency and economic reasons. Generally the development of control design strategies through system dynamics concept had not been considered entirely for structural applications. Structural characteristics which help to divulge structural properties, hitherto flout by civil engineering circle are assimilated with control techniques to construct indices in modal and nodal coordinates for the endurance of the control action to utilize their fullest capabilities. In this study, an isolated 3D steel frame model is developed.  Magneto-Rheological dampers are fixed with 3D steel frame model which act as a smart control device. Besides, Force transducers and Piezoresistive Actuator in tandem with Deltatron conditioning amplifier are also used. Presently many techniques are employed for the optimum placement of actuators and sensors in vibration control systems. The concept of controllability-observability is used in these methods. The specific relationship between the vibration modes and controllability-observability simplifies this approach. This study envisaged the compatibility of force transducers along with triaxial and uniaxial accelerometers fixed at various trial spots on the model structure to quantify the damping force and absolute accelerations of the structure and the dampers individually, positioned in the system, against the excitation of the structure.
Ben Çocuğumu Böyle Besliyorum! Beslenme Konusunda Sosyal Medya Anneleri Üzerine bir Değerlendirme
Authors: HACHISUKA Rina , AKSOY SUGIYAMA Ceren
Published: May 2020

Günümüzde sosyal medya, insanların aynı anda pek çok kişiye kendisini ifade etmekte kullandığı bir araç haline gelmiştir. Sosyal medyayı kullananlar arasında hem kendi hayat tarzlarını hem de ne tür bir anneliği benimsediklerini göstermek amacıyla hesap açan genç kuşak anneler de yer almaktadır. Feminist literatür içerisinde anneliğin sosyal olarak nasıl inşa edildiği ve farklı anneliklerin olup olamayacağı üzerine pek çok tartışma yürütülmektedir. Çocukların beslenmesi konusunda annelerin yaptıkları tercihler ve benimsedikleri pratikler de annelik tanımının içerisinde önemli bir yer tutmaktadır. Bu bağlamda beslenme pratikleri çerçevesinde sosyal medya ortamlarında üretilen ve tüketilen anneliklerin feminist tartışmaların neresinde yer aldığı konusu önemli gözükmektedir. Bu araştırmada özellikle instagram hesapları olan ve takipçi sayısının fazlalığına bakılarak sosyal medyada belirli bir popülariteye sahip olduğu düşünülen annelerin, çocuklu hayata dair paylaştıkları kesitler, yaptıkları paylaşımlar ve onlarla gerçekleştirilen görüşmeler çerçevesinde medya hesapları aracılığıyla nasıl bir anneliği ön plana çıkartmaya çalıştıkları, ne türden bir anneliği inşa ettikleri ve sosyal medyada hangi sebeplerle ve hangi tür paylaşımlarla görünür olmayı istedikleri anlaşılmaya çalışılmıştır. Ayrıca bu hesapları takip eden diğer annelerle de açık uçlu mülakatlar gerçekleştirilerek onların yapılan paylaşımları nasıl yorumladıkları, bu paylaşımların kendi anlam dünyaları ile nasıl bir etkileşim içinde olduğu, çocuk beslenmesine dair sosyal medyada paylaşılanları kendi çocuk yetiştirme pratiklerine ne kadar dahil ettikleri de ortaya konmaya çalışılmıştır. Bu tür bir çalışmanın genç nesillerin beslenmesini düzenleyen biyo-politik rejimler ve daha geleneksel beslenme yöntemleri arasındaki dinamik etkileşimi yansıtacağı düşünülmektedir. Her iki söylem de anneleri kendi anlatılarının aktif uygulayıcıları olarak işe koyarken, kadınların en yeni iletişim kanallarında dahi çocukları yetiştiren birincil kişi olarak kendi görünürlüklerini sağlamaya çalışmaları, kendilerini bu açıdan tanımlamaya çalışmaları ve hegemonik anlatılara nadiren alternatif arayıp onlara neredeyse hiç direnmemeleri de dikkate değerdir.
Health Risk Assessment of Pesticide Residues in Vegetables from River Basin Area
Authors: Chaikasem Supawat , Na Roi-et Veerapas
Published: May 2020

Environmental contaminations with pesticides are considered as one of the major environmental pathways of human exposure leading to a potential threat to human health, especially if there is an accumulation in the trophic levels. This study purposed to investigate the level of pesticide residues and the potential health risk associated with vegetables, surface water, and sediment obtained from the river basin area. The concentrations of 87 pesticides from four main groups namely; organophosphate, organochlorine, pyrethroid, and persistent organic pollutants (POPs) were verified by triple quadrupole GC-MS/MS. The concentration of Parathion methyl, Methidathion, Bromophos methyl, Chlorfenvinphos, Triazophos, Azinphos ethyl, and D-trans-Phenothrin in the sediment samples ranged from 12.99-19.95 μg kg-1. The surface water sample mainly contains p, p'-DDT <0.012 μg L-1 followed by Endrin and Dieldrin <0.08 μg L-1, and Aldrin, Alpha-BHC, Heptachlor <0.004 μg L-1, respectively. The PTI was detected at 0.4 in the sum of surface water samples. The detectable pesticide residues were found in 95% of 20 vegetable samples. The positive of screening vegetables were most obviously contaminated with organophosphate (95%) followed by pyrethroid (40%), organochlorine (20%) and POPs (5%), respectively. The highest concentration of 0.04 mg kg-1 was recorded for Dicrotophos in Kitchen mint (Mentha cordifolia Opiz ex Fresen). Fenpropathrin recorded the lowest concentration of 3.2x10-3 mg kg-1 in corn (Zea mays L.). The highest PTI (31.20) was found in corn. The combined risk index of pesticide residues showed significant health risk to humans more than individual risk index. The health risk indices show that the detected pesticides considered a serious public health problem in the studied area, and there is a need to increment their monitoring to reduce their misuse.