bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of the load supply on hybrid generating system
Authors: Abdillah H , Afandi A N , A’yun A Q
Published: August 2020

Solar Power Plants are strongly influenced by the intensity of solar radiation received by the system. For the availability of sustainable use of electrical energy from solar power, hybridization is needed with Perusahaan Listrik Negara (PLN) sources if Black Out occurs, the combination of the two electrical energy sources is known as the Hybrid Generator. Power plant hybridization is combining two or more power plants with different energy sources, to obtain synergies that provide economic and technical benefits (reliability of the supply system). Hybrid plants will have maximum use if accompanied by load control. Load control aims to efficiently regulate the use of electrical energy so that the generated electrical energy is balanced with the use of the load released so that the Hybrid Generator will not occur Black Out. Based on tests that have been carried out the intensity of sunlight affects the power produced by solar cells. The highest sunlight intensity when testing is during the day at 567 Lux with a voltage value of 21.22 V and current of 0.30 A, while the lowest sunlight intensity is at 17.00 with the intensity of sunlight 56 Lux with a voltage value of 5.5 V and current 0.15 A.
Synthesis and structural characterization of iron chromite nanoparticles: A preliminary study
Authors: Amelia T , Saputro R E , Hidayat N , Taufiq A , Diantoro M , Sunaryono S , Mufti N , Hidayat A
Published: August 2020

In this work, the synthesis of iron chromite nanoparticles was performed employing Indonesian iron sand through the coprecipitation route. The crystal and molecular structures of the prepared iron chromite nanoparticles were characterized by means of XRD and FTIR spectrophotometer. Meanwhile, the elemental mapping and morphology of the samples were evaluated using the SEM-EDX technique. The data analysis results showed that the iron chromite nanoparticles had a spinel cubic structure with the lattice parameters and crystallite size of 8.303 Å and 6.8 nm, respectively. The molecular structure analysis for the FTIR spectrum showed that the Fe and Cr ions placed the tetrahedral and octahedral sites. The average particle size of the iron chromite nanoparticles was 30.4 nm and tended to agglomerate. Interestingly, the elemental mapping indicated that the Fe, Cr, and O atoms distributed homogenously.
Global distribution and cleanup opportunities for macro ocean litter: a quarter century of accumulation dynamics under windage effects
Authors: Ko Chia-Ying , Hsin Yi-Chia , Jeng Ming-Shiou
Published: August 2020

Ocean litter is of growing global concern, and its impacts on marine environments and ecosystems are expected to increase further this century. From a management perspective, natural drifting of macro ocean litter to or near the coast may have a relatively easier opportunity to be cleaned up directly from land, which then helps eliminate litter sufficiently and reduces the associated societal costs. However, quantitative descriptions both of the potential arrival areas of accumulation and of the cumulative impacts of ocean litter and services are lacking. The wind is critical to restructuring litter distributions in locations greatly different from those within the gyres where litter is typically found, prompting strong concerns regarding previously ignored areas, especially the equatorial zone and northern polar regions. As the windage increases, litter is transported across oceans, and polar oceans would become a litter sink instead of a source when litter is simulated to originate from both offshore and coastal areas. Different proportions of offshore- and coastal-source litter exhibit different terminal configurations, including floating offshore, floating near the coast and washed ashore. Notably, depending on windage, 78.4%–94.0% and 54.1%–56.1% offshore- and coastal-source litter continue moving in the oceans. Furthermore, important consequences associated with global marine biodiversity priority areas and litter accumulation are identified, as are substantial increases in influences on phytoplankton biomass with increasing windage. The results not only improve our understandings of macro ocean litter accumulation but also reveal opportunities for proactive prevention and planning of cleanup efforts with relatively low costs regardless of the ocean litter’s offshore or coastal origins and can provide support for regional-to-global actions and policies addressing the contemporary impacts of macro ocean litter on environments.
Topography, drainage capability, and legacy of drought differentiate tropical ecosystem response to and recovery from major hurricanes
Authors: Yu Mei , Gao Qiong
Published: August 2020

High-carbon sequestrations of tropical montane forests and coastal mangroves have been greatly disturbed by intensified extreme climate events such as alternating hurricanes and droughts. However, few studies of the hurricane impact have taken into consideration the legacy of past climate events and analyzed the heterogeneity of hurricane impacts between montane forests and coastal mangroves. Here, we studied the impact of Hurricanes Irma and Maria in 2017 on coastal mangroves and upland forests in Puerto Rico after a severe drought during 2015–2016. We investigated the island-wide immediate impact on greenness using fused vegetation index from Sentinel-2 and Landsat-8, and the impact on and the recovery of 62 homogeneous vegetation patches by deriving an impact index and one-year recovery ratio (RR). A linear mixed-effect model was applied to explore roles of hurricane wind, rainfall, topography, and biological components in the impact and the recovery. Island-wide, the immediate impact is highly spatial-heterogeneous. Although most of the island was browned, a green-up strip in the dry south showed benefits from the hurricane rain which relieved the prior drought stress. Coastal mangroves experienced the greatest impact and slowest recovery with relative recovery of 0.44 compared to recovery greater than 0.70 for upland forests, and evergreen forests sustained significantly more damage than deciduous forests. The recovery of evergreen forests was on average 11 days earlier and faster than that of mangroves. Mangrove recovery was mostly limited by inundation-related factors such as elevation, slope, and drainage capacity. While higher elevation relates to slower recovery for upland forests, it favors mangrove recovery. Particularly, mangrove recovery is facilitated by river presence, explaining 65% variation in RR. The differentiated response, recovery, and underlying mechanisms highlighted a complicated array of external forces, geophysical/ biological modulators, and legacy of past climate events in determining and understanding hurricanes’ impact on tropical ecosystems.
The potential of buoyant fish attractor (BFA) substrates in supporting aufwuchs growth as a new food source in euphotic zones of Lake Maninjau
Authors: Nofdianto
Published: August 2020

“Buoyant Fish Attractor” (BFA) is an artificial floating substrate placed in the euphotic zone of a lake. This substrate is expected to support the conservation of native fish in a lake. The BFA used in this study was an inverted pyramid which was made of wood or bamboo with a size of about 200 cm in length, 200 cm in width, 80 cm in height and equipped with PVC pipes as a buoy. Three types of a substrate mounted on BFA were wood frames, plastic brushes with 40 cm in length and a diameter of 15 cm, and palm fibers placed in six brick roster. Aufwuch samplings were carried out by four times after a month of BFA installation: in July, August, September, and November 2018. The result showed that on the wood media 37 taxa of benthic microalgae were identified which was consisted of Bacillariophyta 55%, Chlorophyta 18%, Cyanophyta 25 %, Protista 2% and dominated by Synedra ulna. On plastic brush media, 11 taxa of invertebrates were identified: Insecta 72%, Crustacea 18%, Annelida 5%, Bryozoa 5%, Mollusca 0.3% dominated by Chironomus sp. On the palm fiber media, 16 taxa of invertebrates were identified: Crustacea 85%, Insecta 7%, Annelida 6%, and Mollusca 2%, dominated by Chydorus sp. Buoyant Fish Attractor (BFA) has a potential to support the growth of aufwuch as a new food source in the lake’s euphotic zone. The variety of media installed on BFA technology could affect the structure and composition of the aufwuch community.
The effect of anthrophogenic changes on the sustainability of eastern sumatran floodplain fisheries resources
Authors: Husnah  , Prianto E , Marini M , Aisyah  , Triharyuni S , Purwoko R M
Published: August 2020

Every human (anthrophogenic) activity along a river system has potential to influence on quantity and quality of aquatic environment and its organisms. Few studies have been conducted to evaluate the effect of these activities on fisheries resources. This paper examines the effect of anthropogenic changes on floodplain ecosystem of Eastern Sumatran fisheries. Fisheries data presented in this paper are derived from a desk study and multi-year field surveys conducted in three provinces; these were Giam Siak Kecil (GSK), Riau Province, and Batanghari River, Jambi Province (2010 to 2016) and Lempuing River, South Sumatra Province (2011-2013, 2016). In GSK, the results showed that there was a tendency for fish size to decrease along the river with decreasing riparian forest and increasing fishing intensity. In the Lempuing floodplain, fisheries degradation had occurred as a result of human activities such as conversion of land area for plantation, unpredictable flood pulses due to the Perjaya irrigation dam, high fishing intensity, and the use of un-friendly fishing gear. The number of fish species, here, decreased dramatically from 90 species in 1981 to 32 fish species in 2011, a decrease of 60% over three decades. In addition, total fish production decreased from 60 tonnes per year before 1996 to 12 tonnes per year in 2012, while the number of uneconomical and small sized fish caught increased. Decreases in fish diversity, size and catch rate were found in Jambi. Fish composition was dominated by small size blackfish (snakehead, climbing perch and Asian redtail catfish). Anthrophogenic activities contributed significantly to the degradation of floodplain fisheries resources, especially in relation to a decrease in forest cover due to fires that occurred between 1996 an 2000. An integrated management plan should be considered in the long term to support the Sustainable Development Goals for floodplain fisheries.
Water quality assessment of Bukit Merah Reservoir, Malaysia using mathematical modeling
Authors: Mokhtar M Z , Sofiana M S , Wan Maznah W O , Teh S Y
Published: August 2020

Bukit Merah Reservoir (BMR), Perak is the oldest man-made reservoir in Malaysia, situated in Kerian District, northern part of Perak, Malaysia, purposely to provide irrigation water to Kerian Irrigation Scheme (KIS) for rice cultivation. Thus, a study focuses on the determination of the current water quality status of the reservoir was conducted in November 2018 and February 2019 as a representative for the wet and dry season, respectively, in order to assist the prediction of the water quality in BMR and its impact towards the ecosystem. Five sampling stations were chosen to provide a general overview of physico-chemical profile in BMR. Physico-chemical parameters (i.e.: temperature, dissolved oxygen, conductivity, total dissolved solids, pH, and water transparency) were measured in situ whereas in the laboratory, total suspended solids, chlorophyll-a, and nutrient analysis were done in accordance to APHA (2005). The concentration of dissolved oxygen (DO) and biological oxygen demand (BOD) were simulated in a graph using Water Quality Analysis Simulation Program (WASP). Based on the analysis conducted throughout the study, the result indicated that the temperature, pH, chlorophyll-a, orthophosphate, and nitrate-nitrogen were higher in November 2018 compared to February 2019 which is 31.3°C, 6.8, 0.0533 µg/L, 0.0158 mg/L, and 0.1731 mg/L, respectively. One-way ANOVA showed that temperature and pH were significantly different between stations (p<0.05). WASP was used to validate the calculation to make sure that other parameters including DO saturation level, BOD loading, BOD decay rate, and reaeration rate values are reflected in the simulation graph. As for the initial study, this model reflects the current condition of DO and BOD level in the reservoir, but in future the reservoir should be divided into segments in order to obtain a more realistic prediction. The accuracy of the predictions can be improved with more input of water quality data.
The application of PlanetScope imagery to map out the trophic state of Cirata Reservoir, West Java
Authors: Musfiroh Z , Ridwansyah I , Murti B S S H
Published: August 2020

Cirata Reservoir is one of the cascade dams in the Citarum Watershed located in three regencies of West Bandung, Cianjur, and Purwakarta. Surface water condition of the Cirata Reservoir is occupied by floating net cages, thus the waste from those activities could affect its trophic state. The purpose of this study is to assess the ability of PlanetScope imagery to map out trophic state parameters and trophic state condition during the rainy season using the Trophic State Index (TSI) method by Carlson (1977). The Carlson’s TSI parameter contains water transparency (Secchi depth) chlorophyll-a, and total phosphorus based on the empirical formula generated from the regression model between image bands with field survey data. Results of the analysis showed that water transparency is strongly correlated with the red band (R2 = 0.60) with an accuracy level of 77.51-81.62%. Chlorophyll-a is strongly correlated with green band (R2 = 0.71) with an accuracy level of 34.69-58.31%, and the total phosphorus is strongly correlated with red band (R2 = 0.65) with an accuracy level of -66.71-5.11%. The result of the three parameters combination reveals that the trophic state of Cirata Reservoir is in the medium eutrophic to hypereutrophic with the largest distribution in the heavy eutrophic class. The results of the accuracy-test indicated that the PlanetScope imagery is able to be used to estimate the parameters of water transparency and chlorophyll-a, whereas the total phosphorus parameter got low accuracy.
Internal wave depiction in Lake Maninjau from high frequency temperature data
Authors: Jasalesmana T , Sunaryani A , Wisesa E T , Melati I , Fakhrudin M
Published: August 2020

Water column of Lake Maninjau has a thermal stratification which sensitive to varying conditions of weather variables, especially to wind forcing. When water column stratified, wind forcing will initiate an internal wave generation in water column. Internal wave has a significant role in physical, chemical and biological processes in lakes. The aim of this study was to illustrate the internal wave in Lake Maninjau. Temperature data and wind speeds were collected from environmental monitoring and warnings system (e-most) device and weather stations of UPT LATPD Maninjau, respectively. The observation periods were conducted for 10 days (April, 1-10 2017). Strong stratification significantly appears in the beginning of observation period. Internal wave drawn from the temperature oscillations at a depth of 1, 9, 14 and 25 m with a vertical V2H1 mode. Our analysis showed that internal waves resonate with wind speed at the frequency of 6.9 × 10−3 cyc/minutes (23.9-h period).
Hydrological Study The Upstream Part of Siak Watershed (Case Study: Tapung Kanan River & Tapung Kiri River)
Authors: Mashuri  , Kiranaratri A H
Published: August 2020

Hydrological analysis is very important in the scientific development of water resources. In the planning and maintenance of civil structures water, the design flood discharge needs to be assessed. Tapung Kanan River and Tapung Kiri River are the upper reaches of the Siak Watershed. The distribution of rainfall around the river fits the gumbel distribution and meets the criteria in the chi square test and the Kolmogorov test. Hyetograph design rain uses the distribution of rain patterns in the Water Research Center with a duration of 3 hours. Based on the reliability of the synthetic unit hydrograph (SUH) ITB-1, the two rivers showed good performance with an average volume accuracy of 98.09% and an average volume/DRO control ratio of 1,0006. Tapung Kanan River Flood discharge for a period of 10 years obtained 6380.83 m3/sec with a runoff volume of 22,664,541.84 m3 while Tapung Kiri River Flood discharge for a period of 10 years obtained 6207.29 m3/sec with a runoff volume of 22,189,284.58 m3.
Design and Architecture of a Public Satisfaction Detection Camera Based on Facial Emotional Analysis
Authors: Tosima Manullang Martin Clinton , Luky Ramdani Ahmad , Migotuwio Namuri
Published: August 2020

One way to measure customer satisfaction is to involve the Internet of Things and Artificial Intelligence in the form of mood recognition services provided by Amazon Web Service and the services available to it, such as S3 (Simple Storage Service, a storage service from AWS), Relational Database Services, Rekognition services (An Image Recognition Services), Application Protocol Interface, Lambda Services. The source of input acquisition in this study uses the ESP-EYE device, the ESP32 microcontroller which has a camera. The device is connected to Amazon web service via the internet. Data is stored in a storage service called S3. S3 is used as a storage bucket, where Lambda will be the center of the process that pre-processes the face image data to crop the edge. After the cropping process, lambda will call the Rekognition service to start the Rekognition services process. The relationship of each data is stored in RDS using MariaDB. The results are, that the internet of Customer Satisfaction Systems can be built with the involvement by several products of Amazon Web Services. There is also considerable efficiency after the face image file has been processed by lambda to crop. The output from the system is recorded in the database and sent back to ESP-EYE for display in the serial monitor. The development of this system can be forwarded to an information system that allows each column in the database to be presented in the form of an information system. This system can help to measure customer satisfaction and recapitulate the results without involving the surveyor team so that it will save operational costs and time efficiency.
Design of Palm Seeds Sorting Machine
Authors: Tamrin T , Lanya Budianto , Warji W , Nasrullah N
Published: August 2020

The need for oil palm seeds in Indonesia has increased lately. Palm seeds can be grown from the kernel. To get a uniform size kernel requires uniform size seeds. This study aims to design, make a separator of palm seeds so that the size of the uniform seeds. The design phase did using a CAD program to draw engineering drawings. Based on engineering drawings, we analyzed and made prototypes of palm seed sorting machines. The size of the prototype was 182 cm long, 50 cm wide and 94 cm high. This machine sorted seeds into large, medium and small dimensions The test results of 300 seeds consisting of 100 large size seeds, 100 medium size seeds and 100 small size seeds, produced 29.5% large size, 30.8% small size 28.2% small size. The capacity of the machine was 60,2 kg per hour. The palm oil seed sorting machine has an optimum percentage of 88.87%.
Efficacy Dietary Supplementation of Banana Peel Meal on Growth and Cannibalism level of Giant Freshwater Prawn (Macrobranchium rosenbergii)
Authors: Rakhmawati R , Marlina E , Warji W
Published: August 2020

Banana peels contain the amino acid tryptophan which is thought to support growth and suppress cannibalism in giant prawns. The purpose of this study was to evaluate the efficacy dietary supplementation of banana peel meal on growth performance and cannibalism level of giant freshwater prawn (Macrobanchium rosenbergii). Four isonitrogenous and isocaloric experimental diets were prepared by supplementing different levels of dietary banana peel meal: a control group, four groups supplemented with banana peel meal (0, 2.5; 5 and 7.5% of weight feed) were fed to triplicate groups with the density of 200 giant prawn m−3. After a 45-day feeding experiment, the growth performance includes weight gain, daily growth rate, feed efficiency, and cannibalism level were measured. Banana peel meal supplementation significantly decreased (P <0.05) cannibalism level at 5% weight feed. In addition, its weight gain and feed efficiency significantly higher but the daily growth rate was not significantly different. The result of the present study suggested that feed efficiency increased and the cannibalism level of giant prawn significantly decreased by feeding diets supplemented with banana peel meal (5% of weight feed).
Financial Feasibility of Liquid Sugar Production from Sago Starch with Enzymatic Hydrolysis Method
Authors: Dewi Hartami , Maryam  , Putri Gustiarini Rika
Published: August 2020

The objective of this research was to analyse the feasibility of processing sago starch into liquid sugar product with enzymatic hydrolysis method on the pilot plant scale. Optimization of the production process is carried out by enzymatic hydrolysis with the conditions of the ratio of starch and water is 1: 4, the process of liquidation at 90°C for 90 minutes with the addition of the enzyme α-amylase 1.2 mL kg-1 at pH conditions of 5. Saccharification process with the addition of the enzyme glucoamylase 1.2 mL kg-1 starch at pH 4.5 and temperature 50°C for 72 hours, purification with an ion exchange resin and evaporation with a vacuum evaporator at a pressure of 0.4 atm at 80°C for 90 minutes. Financial analysis was based on the prevailing price in ten years showed that the processing sago starch into liquid sugar product with enzymatic hydrolysis method is viable and profitable as shown by BCR 1.16, NPV of Rp 58,754,955.64, PBP 2 years 11 months, and IRR 34.73%.
Identification of Phenyl Propanoid Compound Isolated from Root Bark Datuan(Ficus vasculosa Wall. Ex Miq) and Antibacterial Activity Test on Escherichia coli
Authors: Bahri S , Ambarwati Y , Marlina L , Utami
Published: August 2020

The purpose of this research was to identify phenyl propanoid compounds found in the root bark of Datuan (Ficus vasculosa Wall. Ex Miq) and to test the activity of Escherichia coli. Isolation was carried out by maceration method using methanol as a solvent. Then the extract was fractionated by Vacuum Liquid Chromatography and Gravity Column Chromatography methods using n-hexane, ethyl acetate, and methanol eluents. The result was obtained a yellow crystal needle orange weighing 20 mg with a melting point of 137°C - 140°C. Separation by TLC method showed that this compound had an Rf value of 0.56 with n-hexane: acetone eluent (6: 4). UV-Vis spectra showed three peaks on 310 nm, 228 nm and 200 nm. IR spectra showed that the isolated compound has unsaturated ester carbonyl groups conjugated with double bonds, aromatic substituted aromatic rings, and hydroxy groups. GC-MS analysis obtained molecular ions M+ = 178. The data of UV-Vis, IR and GC-MS analysis can be concluded that the isolated phenyl propanoid compound is a cinnamic derivative that is methyl p-hydroxycinamic. The results of bioactivity tests on E. Coli showed that the isolated compounds did not have antibacterial activity which was marked by the absence of a clear zone around the paper disk.
The effects of frequency and amplitude of vibration on the mixing and segregation processes in granular materials
Authors: Mahdi Bahaulddin D , Faleh Nadhim M
Published: August 2020

The mixing and segregation process of almost identical size binary steel-glass mixture within a vertically vibrated container are investigated in this study. The container is designed to allow only one layer of granules inside. In this study, the image processing techniques and particles tracking methods are employed to track the convection flow of granular materials. Six different amounts of frequency (20, 25, 30, 35, 40, and 50 Hz) for certain amplitudes are used to study the effects of miscellaneous vibration conditions on the velocity fields of moving beads. The granular bed was divided into three horizontal parts and a separate study was provided for each one. The discrete-element method and EDEM software are employed for simulating the response of steel beads under 2D vertical vibration. Good agreements between simulated and experimental results have been presented in the current work. There are one or two convection cells generated in the vibrated bed for all tests, and the amount of amplitude was the most important factor in determining the number of these cells. The heavier particles tend to move toward the convection cells centers within the container unlike the lighter particles. The average velocity of steel beads increased with amplitude, while it decreased by increasing the frequency of vibration. In addition, the steel beads concentration in the middle region of the container increased with the vibration time.
Experimental Study on Electrodes Types in Electrical Discharge Machining (EDM) of High-Speedd Steel
Authors: Aghdeab Shukry H. , Khudhier Waqass S. , Elias Rasha R.
Published: August 2020

Electrical Discharge Machining (EDM) is widespread Nontraditional machining (NTM) Processes for manufacturing complicated geometry or very hard metals parts that are difficult to machine by traditional machining operations. Electrical discharge machining is a material removal rate (MRR) process characterized by using electrical discharge erosion. This paper discusses the optimal parameters of EDM on high-speed steel (HSS) AISI M2 as a workpiece using copper and brass as an electrode. The input parameters used for experimental work are Current (10, 24 and 42 A), Pulse duration (100, 150 and 200 µs), and Pulse pause-Time (4,12, and 25 µs) that effect on the material removal rate (MRR), and Electrode Wear Rate(EWR). A Minitab (17) software environment to adopt the Full Factorial Method method to analyze the effect of input on the response of EDM. The results showed that the higher value of MRR and the lower value of EWR offered via the copper electrode. The most influential factor that effect the process response (MRR, and EWR) is pulse current.
Surface segmentation and reconstruction in reverse engineering
Authors: Marzoog R J , Alduroobi A A , Al-Zubaidy S S
Published: August 2020

Reverse Engineering (RE) is the process by which the geometry of a physical part is recreated digitally by digitizing and data modification. RE main difficulty is surface reconstruction. This difficulty increases by increasing part complexity. In this research, a developed reverse engineering approach has been adopted to create a 3D CAD model for power stern. The approach begins from the existing and goes through three main steps (scanning, data pre-processing, and part segmentation and surface reconstruction) and finalize to a readable CAD model. A mathematical representation for the NURB curve has been created to formalize the edges of segments then reconstructing plan and tabulated surfaces according to the segment geometry. Algorithms and computer programs using MATLAB programs have been built to implement the proposed approach and save the data.
Design and Implementation of Intelligent MPPT Based on FPGA for PV System
Authors: Mahmood Mohanad H. , Ali Inaam I. , Ahmed Oday A.
Published: August 2020

This paper presents the design and implementation of intelligent maximum power point tracking (MPPT) technique for Photovoltaic (PV) systems. The proposed MPPT is based on the fuzzy logic controller (FLC). FLCs have the benefit of being very easy to design as they don’t need accurate knowledge of the system and work well for the nonlinear system. The MATLAB/Simulink was used to verify the proposed method, with three scenarios of environment conditions. The DC-DC converter has been designed and simulated using PLECS simulation software, then implemented practically in order to work as impedance matching between PV source and load. The system was built based on Field Programmable Gate Array (FPGA) and connected to the PV panel and tested practically at the site for different environment conditions and compared with measurements obtained using solar analyzer device. According to the simulated and experimental results, the proposed method capable to find the maximum power point (MPP) under different climate conditions excellently with compared to perturb and observation (P&O) method. Also, it has very low oscillation about (MPP) and high response, as a result, efficiency is enhanced, providing maximum power transfer to load.
Modeling and simulation of 1kw single phase grid tied inverter for solar photovoltaic system
Authors: Hasan Murtadha Jasim
Published: August 2020

Solar energy is considered as fastest growing renewable energy source after wind energy for electricity generation. And it is considered environmentally friendly. to effectively implements intelligent systems that feed household generated surplus power to distribution feeder network, modeling and simulation of the grid tied solar system is of high importance. The paper models the 1KW roof solar grid mooring system for the home connected to a 230-240 V single phase grid. The study proposes a converter topology with an efficient output voltage control system that synchronizes the phase, the frequency and voltage of the inverter with the network. The MPPT DC-DC converter, controlled by Perturb and Observe (P&O), generates the maximum power when it is detected that the mains voltage provides a control signal for the synchronous operation of the converter and the drive with the mains voltage. The developed model has been implemented and simulated using MATLAB/SIMULINK. Dynamic changes in the network voltage have been applied to evaluate the performance of the voltage controller and the DC-DC converter. The results show that the power output to the network depends not only on the level of power quality, but also on a rapid dynamic response to changes in voltage, phase and frequency, and the output of this system is low, simple, profitable and efficient. For photovoltaic solar applications.
Effect of calcium carbonate treated crumb rubber and oil palm fruit fibre on the mechanical properties of mortar
Authors: Sharba Amjad A.
Published: August 2020

The present research was conducted to trace the influence of calcium carbonate by treating crumb rubber and exploiting oil palm fruit fibre (OPFF) incorporated mortars. The mechanical properties of treated crumb rubber and the addition of OPFF mortar being added at 0.5% OPFF and crumb rubber replacement of 0-30% by volume of aggregate were examined. The composites were subjected to compression, split tensile test, ultrasonic pulse velocity (UPV) and flexural test. The use of calcium carbonate by treating crumb rubber showed a recovery in the losses of rubberized mortar strength. The percentage 0.5% of OPFF added to the composite showed enhancement to the compressive strength, split tensile strength, UPV and flexural strength of the mortar composites. These findings provide a future possibility for using such wastes to decrease the negative effect on the environment they cause and increase the mechanical properties of composites they are added to.
Optimisation of electro-spark coating method
Authors: Yu Loginov N , Gulyaev V A , Yu Khudyakova O
Published: August 2020

Application of wear resistant coatings on cutting tools in a technological process requires taking into account multiple factors. Optimisation of the hardening process presents one of the main steps that needs to be addressed. This paper describes a method of optimisation of the electro-spark coating (ESC) process. The performance of the process was chosen as the target function. A parametric function was defined based on the previously developed mathematical model of the process whereby the condition of the strong connection of coating material with the foundation was used. Another parametric function is a prerequisite for a suitable coating thickness. Additional limitations are the characteristics of the equipment for the reinforcement
Antioxidant in a model biomembrane – astaxanthin and its esters mixed with DPPC in Langmuir films
Authors: Kulikov E A , Stupnikov A A , Malakhova Y N
Published: August 2020

Amphiphilic properties of astaxanthin molecule and its esters make it possible to include it in self-organized structures based on lipid membrane components. Astaxanthin and its mono- and diesters were isolated from the extract of the microalgae Haematococcus Pluvialis, purified by column chromatography, and identified by thin-layer chromatography. The absence of impurities in astaxanthin and its esters was confirmed by means of high performance liquid chromatography method with detection in the ultraviolet-visible region and mass spectrometric detection. The model systems of the cell membrane lipid bilayer — Langmuir films of mixtures of DPPC with astaxanthin and its mono- and diesters, were formed at the air-water interface and studied by a complex of methods. It was found that an increase in the amount of astaxanthin, as well as the addition of its esters to the Langmuir films of DPPC, leads to an increase of values of area per molecule at the surface pressure isotherm uprise and decrease of Langmuir film collapse pressure. The addition of astaxanthin mono- and diesters prevents the phase transition in the DPPC monolayer more strongly than unesterified astaxanthin.
Using Machine Learning Radial Basis Function (RBF) Method for Predicting Lubricated Friction on Textured and Porous Surfaces
Authors: Boidi Guido , da Silva Márcio Rodrigues , Profito Francisco J , Machado Izabel Fernanda
Published: August 2020

The coefficient of friction (CoF) obtained from tribological tests conducted on textured and porous surfaces was analysed using the machine learning Radial Basis Function (RBF) method. Non-textured and non-porous samples were taken as reference surfaces. Test parameters, such as entrainment velocity and slide-roll ratio (SRR), along with geometric characteristics of surface features (e.g. texture width and depth, coverage area, circularity, spatial distribution and directionality, among others), were selected as training dataset for the machine learning RBF model. The surface features were divided into designed patterns (dimples and grooves) manufactured by laser texturing, and randomised cavities (surface pores) resulted from the sintering process. The principal outcomes of this study are the effective use of the machine learning RBF method for tribological applications, as well as a critical discussion on its feasibility for the experimental dataset selected and the preliminary results obtained. Main results show that the Hardy multiquadric radial basis function provided an overall correlation coefficient of 0.934 for 35 poles. The application of the suggested machine learning technique and methodology can be extended to other experimental results available in the literature to train more robust models for predicting tribological performances of textured and structured surfaces.
Associations of ω-3 Fatty Acids With Interstitial Lung Disease and Lung Imaging Abnormalities Among Adults
Authors: Kim John S , Steffen Brian T , Podolanczuk Anna J , Kawut Steven M , Noth Imre , Raghu Ganesh , Michos Erin D , Hoffman Eric A , Axelsson Gisli Thor , Gudmundsson Gunnar , Gudnason Vilmundur , Gudmundsson Elias F , Murphy Rachel A , Dupuis Josée , Xu Hanfei , Vasan Ramachandran S , O’Connor George T , Harris William S , Hunninghake Gary M , Barr R Graham , Tsai Michael Y , Lederer David J
Published: August 2020

Docosahexaenoic acid (DHA), an ω-3 polyunsaturated fatty acid, attenuates interstitial lung disease (ILD) in experimental models, but human studies are lacking. We examined associations of circulating levels of DHA and other polyunsaturated fatty acids with hospitalization and death due to ILD over 12 years in the Multi-Ethnic Study of Atherosclerosis (MESA; n = 6,573). We examined cross-sectional associations with CT lung abnormalities in MESA (2000–2012; n = 6,541), the Framingham Heart Study (2005–2011; n = 3,917), and the Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-Reykjavik) (2002–2006; n = 1,106). Polyunsaturated fatty acid levels were determined from fasting blood samples and extracted from plasma phospholipids (MESA and AGES-Reykjavik) or red blood cell membranes (Framingham Heart Study). Higher DHA levels were associated with a lower risk of hospitalization due to ILD (per standard-deviation increment, adjusted rate ratio = 0.69, 95% confidence interval (CI): 0.48, 0.99) and a lower rate of death due to ILD (per standard-deviation increment, adjusted hazard ratio = 0.68, 95% CI: 0.47, 0.98). Higher DHA was associated with fewer interstitial lung abnormalities on computed tomography (per natural log increment, pooled adjusted odds ratio = 0.65, 95% CI: 0.46, 0.91). Higher DHA levels were associated with a lower risk of hospitalization and death due to ILD and fewer lung abnormalities on computed tomography in a meta-analysis of data from population-based cohort studies.
Uric Acid Is Not Associated With Blood Pressure Phenotypes and Target Organ Damage According to Blood Pressure Phenotypes
Authors: Cai Anping , Liu Lin , Siddiqui Mohammed , Zhou Dan , Chen Jiyan , Calhoun David A , Tang Songtao , Zhou Yingling , Feng Yingqing
Published: August 2020

BACKGROUND

Hypertensive patients with increased serum uric acid (SUA) are at increased cardiovascular (CV) risks. Both the European and American hypertension guidelines endorse the utilization of 24 h-ambulatory blood pressure monitoring (24 h-ABPM) for hypertensive patients with increased CV risk. While there is difference in identifying uric acid as a CV risk factor between the European and American guidelines. Therefore, it is unknown whether 24 h-ABPM should be used routinely in hypertensive patients with increased SUA.

METHODS

To address this knowledge gap, we investigated (i) the correlation between SUA and 24 h-ABP; (ii) the association between SUA and blood pressure (BP) phenotypes (controlled hypertension [CH], white-coat uncontrolled hypertension [WCUH], masked uncontrolled hypertension [MUCH], and sustained uncontrolled hypertension [SUCH]); (iii) the association between SUA and target organ damage (TOD: microalbuminuria, left ventricular hypertrophy [LVH], and arterial stiffness) according to BP phenotypes.

RESULTS

In 1,336 treated hypertensive patients (mean age 61.2 and female 55.4%), we found (i) there was no correlation between SUA and 24 h, daytime, and nighttime systolic blood pressure/diastolic blood pressure, respectively; (ii) in reference to CH, SUA increase was not associated WCUH (odds ratio [OR] 0.968, P = 0.609), MUCH (OR 1.026, P = 0.545), and SUCH (OR 1.003, P = 0.943); (iii) the overall prevalence of microalbuminuria, LVH, and arterial stiffness was 2.3%, 16.7%, and 23.2%, respectively. After adjustment for covariates, including age, sex, smoking, body mass index, diabetes mellitus, and estimated glomerular filtration rate, there was no association between SUA and TOD in all BP phenotypes.

CONCLUSIONS

These preliminary findings did not support routine use of 24 h-ABPM in treated hypertensive patients with increased SUA.
Patient Satisfaction Following Inverted-T and Short-Scar Mammaplasty as Measured by the Breast Evaluation Questionnaire 55
Authors: Pontes Gisela Hobson , Mendes Carneiro Filho Fernando Sérgio , Vargas Guerrero Luis Alejandro , Takahashi Rodrigues Pinto Carolina , Serra-Guimarães Fernando
Published: August 2020

Background

Mastopexy combined with silicone implant placement is one of the most frequently performed plastic surgeries. Various techniques have been developed to increase the degree of patient satisfaction after surgery. The goal is to give the breasts a harmonious shape, generating the smallest scars possible. The Breast Evaluation Questionnaire 55 (BEQ 55) was developed in 2006 as a tool for assessing the satisfaction and comfort of patients with the general appearance of their breasts.

Objectives

The objective of this study was to compare the degree of satisfaction of patients undergoing mastopexy by the inverted-T technique vs the short-scar technique by the BEQ 55.

Methods

The BEQ 55 was administered pre- and postoperatively to 200 patients who underwent mastopexy performed by the first author between October 2013 and September 2017. One hundred patients underwent the short-scar technique, and 100 patients underwent the inverted-T technique.

Results

The first analysis used descriptive statistics. Relative frequencies were used to track the responses corresponding to each technique. There was an increase in the level of patient comfort and satisfaction with breast appearance after surgery in both groups. The short-scar technique was shown to be superior, with statistical significance (P < 0.05) found for the questions evaluating comfort with overall appearance naked, comfort with breast appearance naked, and satisfaction with breast appearance.

Conclusions

Both techniques improved the patients’ satisfaction and comfort with their breasts. When the short-scar technique was used, patients were more comfortable with their breast appearance and with their overall appearance naked.

Level of Evidence: 4
Combined Use of Cu(II)-L-Histidine Complex and β-Cyclodextrin for the Enantioseparation of Three Amino Acids by CE and a Study of the Synergistic Effect
Authors: Xu Zifu , Guan Jin , Shao Huili , Fan Shitong , Li Xiaoyu , Shi Shuang , Yan Feng
Published: August 2020

A new capillary electrophoresis method was applied to chiral separation of three amino acids, including D,L-tryptophan, D,L-tyrosine and D,L-phenylalanine. The chiral resolution was attained in an untreated fused-sillica capillary using a dual chiral selector, which was made up of Cu(II)-L-histidine complex and β-cyclodextrin (CD). The cardinal factors influencing its separation efficiency, such as chiral selectors, buffer pH and applied voltage, were optimized. Best results were acquired by using a buffer consisting of 10 mmol/L Cu(II), 13 mmol/L L-histidine, 8 mmol/L β-CD, 5 mmol/L phosphate adjusted to pH 5.0 and 15 kV applied voltage. All enantiomers were entirely resolved within 20 min with high resolutions of 3.6~6.1. The analysis method was verified through the determination of D,L-tryptophan in terms of linearity, precision and accuracy. And the robustness of this method was proved. The Limit of Detection and Limit of Quantification for both enantiomers were 2.5 and 5 μg/mL, respectively. The method was perfectly applied to the determination of the enantiomeric purity of L-tryptophan. Furthermore, the interaction between Cu(II)-L-histidine complex and β-CD was also studied using Ultraviolet-visible and 1H NMR spectroscopy to explain the synergistic effect involved. The results illustrated that Cu(II)-L-histidine complex and β-CD played a synergistic role in the enantiomeric separation of chiral drugs, with good prospects for application.
A specific combination of dual index adaptors decreases the sensitivity of amplicon sequencing with the Illumina platform
Authors: Hirose Yuu , Shiozaki Takuhei , Hamano Itsuki , Yoshihara Shizue , Tokumoto Hayato , Eki Toshihiko , Harada Naomi
Published: August 2020

Amplicon sequencing is a powerful approach in microbiome studies as it detects live organisms with high sensitivity. This approach determines the composition of sequence variants of marker genes using high-throughput DNA sequencers. The use of dual index adaptors is the fundamental technique for pooling DNA libraries for Illumina sequencers and is believed not to affect the results. However, here, we observed a decrease of sequence quality in samples containing a specific combination of indexes, namely N704 and S507 in Nextera kits, in multiple runs on the Illumina MiSeq sequencer operated in different facilities. This decrease was also observed when sequencing randomly fragmented DNA of Escherichia coli and was not observed when either individual adaptor was used. Each end of the DNA library with this index combination contains a complementary sequence motif, which potentially inhibits proper cluster generation and/or subsequent sequencing. Community analysis of the 16S and 18S rRNA amplicons using QIIME2 revealed significant decreases in α-diversity in the samples containing the N704/S507 index combination, resulting from loss of low-abundance sequence variants during denoising. Our data underscore the importance of quality validation of sequence reads in developing dual index techniques and suggest cautious interpretation of microbiome data containing low-quality sequence reads.
Feasibility and efficacy of left bundle branch area pacing in patients indicated for cardiac resynchronization therapy
Authors: Li Yuqiu , Yan Lirong , Dai Yan , Zhou Yu’an , Sun Qi , Chen Ruohan , Lin Jinxuan , Jin Yuanhao , Chen Feng , Guo Xiaogang , Chen Keping , Zhang Shu
Published: August 2020

Aims

The present study was to evaluate the feasibility and clinical outcomes of left bundle branch area pacing (LBBAP) in cardiac resynchronization therapy (CRT)-indicated patients.

Methods and results

LBBAP was performed via transventricular septal approach in 25 patients as a rescue strategy in 5 patients with failed left ventricular (LV) lead placement and as a primary strategy in the remaining 20 patients. Pacing parameters, procedural characteristics, electrocardiographic, and echocardiographic data were assessed at implantation and follow-up. Of 25 enrolled CRT-indicated patients, 14 had left bundle branch block (LBBB, 56.0%), 3 right bundle branch block (RBBB, 12.0%), 4 intraventricular conduction delay (IVCD, 16.0%), and 4 ventricular pacing dependence (16.0%). The QRS duration (QRSd) was significantly shortened by LBBAP (intrinsic 163.6 ± 29.4 ms vs. LBBAP 123.0 ± 10.8 ms, P < 0.001). During the mean follow-up of 9.1 months, New York Heart Association functional class was improved to 1.4 ± 0.6 from baseline 2.6 ± 0.6 (P < 0.001), left ventricular ejection fraction (LVEF) increased to 46.9 ± 10.2% from baseline 35.2 ± 7.0% (P < 0.001), and LV end-diastolic dimensions (LVEDD) decreased to 56.8 ± 9.7 mm from baseline 64.1 ± 9.9 mm (P < 0.001). There was a significant improvement (34.1 ± 7.4% vs. 50.0 ± 12.2%, P < 0.001) in LVEF in patients with LBBB.

Conclusion

The present study demonstrates the clinical feasibility of LBBAP in CRT-indicated patients. Left bundle branch area pacing generated narrow QRSd and led to reversal remodelling of LV with improvement in cardiac function. LBBAP may be an alternative to CRT in patients with failure of LV lead placement and a first-line option in selected patients such as those with LBBB and heart failure.