bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis and design of a multi‐channel constant current LED driver based on DC current bus distributed power system structure
Authors: Zu Aqian , Luo Quanming , Huang Jian , He Qingqing , Sun Pengju , Du Xiong 
Published: November 2019

The colourful light emitting diode (LED) strings require the corresponding driver to achieve independent control of each output current in the applications of RGB mixed colour LED lighting, LED projection etc. For this purpose, a multi‐channel constant current LED driver based on DC current bus distributed power system structure is proposed and analysed here, which is composed of a source converter and several load converters as needed. The source converter adopts the flyback converter to realise power factor correction, electrical isolation, and the load converter adopts the current‐type buck converter to realise independent control of the corresponding output current. A 60 W experimental prototype for 42.8 V/0.35 A, 40 V/0.5 A, 35.7 V/0.7 A three outputs with the universal input voltages 90–264 V is designed and implemented, and the experimental results are presented to verify the correctness of the theory analysis.
Hybrid full‐bridge converter with wide output voltage for high‐power applications
Authors: Zhao Qinglin , Liu Wei , Wang Deyu , Li Kunlun , Wang Yujie 
Published: November 2019

A hybrid full‐bridge converter that consists of a secondary‐side phase‐shift full‐bridge converter (SPS‐FBC) and a full‐bridge LLC converter is proposed in this study. The wide zero‐voltage switching (ZVS) range of the primary switches can be achieved and the series inductor of the SPS‐FBC converter does not need to be specially designed to help achieving the soft switching operation with a set of shared high frequency inverter circuits. The dual outputs of the proposed hybrid converter are connected in series, reducing the voltage stress of the power device in the secondary side. The whole dc‐output voltage can be regulated by primary‐side phase‐shift and secondary‐side phase‐shift dual‐mode control scheme within the desired voltage range, by which the two output voltages are regulated independently and free from cross‐regulation. Therefore, the proposed converter is suitable for high voltage, high power and wide output voltage range applications. The working principle and steady‐state characteristics of the proposed converter are presented and verified in experiment of a 3 kW prototype. The experimental results show that the proposed converter maintains high efficiency throughout the voltage range, and the peak efficiency is 97.43%.
Circumbinary exoplanets and brown dwarfs with the Laser Interferometer Space Antenna
Authors: Danielski C. , Korol V. , Tamanini N. , Rossi E. M. 
Published: November 2019

Aims. We explore the prospects for the detection of giant circumbinary exoplanets and brown dwarfs (BDs) orbiting Galactic double white dwarfs (DWDs) binaries with the Laser Interferometer Space Antenna (LISA).
Methods. By assuming an occurrence rate of 50%, motivated by white dwarf pollution observations, we built a Galactic synthetic population of P-type giant exoplanets and BDs orbiting DWDs. We carried this out by injecting different sub-stellar populations, with various mass and orbital separation characteristics, into the DWD population used in the LISA mission proposal. We then performed a Fisher matrix analysis to measure how many of these three-body systems show a periodic Doppler-shifted gravitational wave perturbation detectable by LISA.
Results. We report the number of circumbinary planets (CBPs) and BDs that can be detected by LISA for various combinations of mass and semi-major axis distributions. We identify pessimistic and optimistic scenarios corresponding, respectively, to 3 and 83 (14 and 2218) detections of CBPs (BDs), observed during the length of the nominal LISA mission. These detections are distributed all over the Galaxy following the underlying DWD distribution, and they are biased towards DWDs with higher LISA signal-to-noise ratio and shorter orbital period. Finally, we show that if LISA were to be extended for four more years, the number of systems detected will be more than doubled in both the optimistic and pessimistic scenarios.
Conclusions. Our results present promising prospects for the detection of post-main sequence exoplanets and BDs, showing that gravitational waves can prove the existence of these populations over the totality of the Milky Way. Detections by LISA will deepen our knowledge on the life of exoplanets subsequent to the most extreme evolution phases of their hosts, clarifying whether new phases of planetary formation take place later in the life of the stars. Such a method is strongly complementary to electromagnetic studies within the solar region and opens a window into the investigation of planets and BDs everywhere in the entire Galaxy, and possibly even in nearby galaxies in the Local Group.
Investigations of influence of epoxy composite coatings on hydrodynamics and heat transfer processes of compact small diameter tube bundles
Authors: Gorobets Valery , Bohdan Yurii , Trokhaniak Viktor , Antypov Ievgen , Bohdan Alla 
Published: November 2019

Tube bundles with cross flow heat carrier chart are widely used in many power systems due to their relatively simple design, low cost, low pressure drops, high efficiency etc. In order to exploitation these tube bundles in dirty and aggressive applications, protective coatings can be applied to the heat transfer surface to enhance effectiveness and minimize pollutant deposits. Protective coatings generally using for improving wear resistance, corrosion resistance, thermal conductivity to heat transfer surface and thermal insulation of frame surfaces of heat exchangers.
In this work physico-mechanical and thermophysical properties of heat conduct coating materials forheat transfer surface are investigated. Experimental and numerical investigations of hydrodynamics andheat transfer processes for compact small diameter tube bundles coated by epoxy composite with high thermal conductivity nanofillers are presented.
Experimental investigations of investigated tube bundles were carried out in open circuit section type wind tunnel of subsonic speeds.
Association of Hemorrhoid Vascular Injuries with Cigarette Smoking—An Evaluation with Interesting Prospects
Authors: Nagaraj Savitha V. , Mori Amit , Reddy Madhavi 
Published: November 2019

Abstract
Background Hemorrhoids are vascular structures in the anal canal which are seldom used to evaluate vascular diseases. Cigarette smoking is well-known to cause both arterial and venous vascular injuries. However, the impact of smoking on hemorrhoid vasculature is unknown.
Objective Considering that vasculature in the hemorrhoids has the same anatomy and pathophysiology of vascular damage as other systemic vasculatures, we conducted this study to evaluate the relation between smoking and incidence of hemorrhoidal vascular injury.
Design and Data Analysis Retrospective review of all the screening colonoscopies performed at our Department of Gastroenterology (predominantly serving urban minority population) over 3 years was conducted and patients with recorded smoking history were included in the study (n = 242). Fisher's exact test with two-tailed p-value and odds ratio were used to evaluate for the association between smoking and incidence of hemorrhoids.
Results We studied 242 subjects and found statistically significant association between smoking and hemorrhoids (p < 0.05) with the risk of developing hemorrhoids among smokers being 2.4 times that of a nonsmoker. We further noted no significant difference in the incidence of hemorrhoidal vascular injuries between the past versus current smokers and male versus female smokers.
Conclusion This is one of the first studies to establish an association between smoking and hemorrhoids. Our study shows that the hemorrhoidal vasculature is impacted by smoking similar to other vascular systems. This study sheds light on the possibility of evaluating hemorrhoids for clues of other systemic and gastrointestinal vascular damage. This correlation can add clinical value especially given the flexibility of assessing hemorrhoids as an outpatient in a cost effective and comfortable manner.
Pre-trialling considerations and activities.
Authors: Sitepu B. , Laksono N. D. , Setiawati U. , Nur F. , Rahmaningsih M. , Anwar Y. , Widodo P. , Forster B. P. , Purba A. R. 
Published: November 2019

Abstract

Before trialling can begin, various considerations and preparations need to be made. First it is beneficial to know if the trait of interest is governed mainly by genetic or environmental factors. If the trait is controlled by genes which are little affected by the environment then field trials may be set up in a narrow range of environments. If, however, the trait is strongly affected by environment, for example, soil type or climate, then trials need to be more extensive to give an estimate of the environmental and genotype x environment interaction. Multi-locational trials can determine the extent of genetic versus environmental factors involved. Plant breeding is an essential pre-trialling activity as it supplies progeny that have potential for crop improvement (see Setiawati et al., 2018, this series). Field performance testing, in turn, is essential in selecting the progenies or palms sought. Materials for field trialling are seedlings. These are made ready for trialling in the nursery (see Laksono et al., 2019, this series). Coordination is therefore required in preparing planting materials and land preparation for the trial. These aspects are discussed.
Material preparation.
Authors: Sitepu B. , Laksono N. D. , Setiawati U. , Nur F. , Rahmaningsih M. , Anwar Y. , Widodo P. , Forster B. P. , Purba A. R. 
Published: November 2019

Abstract

The aim of oil palm trialling is to evaluate field performance among a range of genotypes and to select those of interest. A basic necessity is the provision of good quality planting material, usually produced from deliberate cross-pollinations. Details of methods in pre-trialling activities, i.e. in crossing, seed production and the production of field-ready planting materials, are given in Kelanaputra et al. (2018), Setiawati et al. (2018) and Laksono et al. (2019), respectively (this series of manuals). Thus, only brief overviews of these operations are given here.
Anti-fraud measures in Southern Africa
Authors: Mykhalchenko Nataliya , Wiegratz Jörg 
Published: November 2019

SUMMARY
In response to the rising levels of fraud in many countries and the global economy more generally, public and private actors in both the global North and the global South have in recent years introduced initiatives in the name of countering fraud in the ‘private sector’. This briefing explores such anti-fraud measures in four countries in the Southern African region: Malawi, Botswana, South Africa and Zambia. Using online data (news outlets and reports on websites of private companies and governmental agencies), the authors provide a country-by-country account of some of the drivers and characteristics of these measures.
Extracellular vesicles and coagulation in blood from healthy humans revisited
Authors: Berckmans René J. , Lacroix Romaric , Hau Chi M. , Sturk Auguste , Nieuwland Rienk 
Published: November 2019

ABSTRACTBackground: In 2001, we studied the presence and coagulant properties of “microparticles” in the blood of healthy humans. Since then, multiple improvements in detection, isolation and functional characterization of the now called “extracellular vesicles” (EVs) have been made, and shortcomings were identified. Aim: To revisit the presence and function of EVs in blood from healthy humans. Methods: Blood was collected from 20 healthy donors. EV‐containing plasma was prepared according to new guidelines, and plasma was diluted to prevent swarm detection. Single EVs were measured by flow cytometry with known sensitivity of fluorescence and light scatter. The haemostatic properties of EVs were measured by thrombin‐, fibrin‐, and plasmin generation. Plasma concentrations of thrombin‐antithrombin complexes and prothrombin fragment 1 + 2 were measured to assess the coagulation status in vivo. Results: Compared to 2001, the total concentrations of detected EVs increased from 190‐ to 264‐fold. In contrast to 2001, however, EVs are non‐coagulant which we show can be attributed to improvements in blood collection and plasma preparation. No relation is present between the plasma concentrations of EVs and either TAT or F1 + 2. Finally, we show that EVs support plasmin generation. Discussion: Improvements in blood collection, plasma preparation and detection of EVs reveal that results from earlier studies have to be interpreted with care. Compared to 2001, higher concentrations of EVs are detected in blood of healthy humans which promote fibrinolysis rather than coagulation.
Applications of solar dryer for seaweed and cassava starch
Authors: Suherman Suherman , Susanto Evan Eduard , Busairi Abdullah 
Published: November 2019

Abstract
In this paper, the comparisons of seaweed and cassava starch drying using a newly-designed solar dryer is invesigated. The drying operation was done in 2 days, from 8.00 A.M until 4.00 P.M on each day. Both seaweed and cassava starch were rewetted and prepared before drying. Experimental results showed that drying time affects the value of relative humidity and drying temperature. It was shown that drying temperature is invesely proportional to relative humidity. The relative humidity and temperature curves of seaweed drying and starch drying show relatively similar results. The drying process was able to reduce seaweed’s moisture content from 72,6% to 12,6% in tray 1, and from 72,6% to 14,1% in tray 2, while the cassava starch’s moisture content is reduced from 52,6% to 7,05% on tray 1 from 52,6% to 13,81% on tray 2. All results have met their respective standards of moisture content. The drying rate fluctuates as the drying time changes, with drying temperature significantly affects the drying rate. The product qualities of seaweed and cassava starch show acceptable results based on their respective standards. It can be concluded that solar dryer is a suitable alternative for easier drying and good product quality.
Optimization for Production Tert-Butyl Glycoside Nonionic Surfactant Using Response Surface Methodology
Authors: Pawignya Harsa , Kusworo T. D. , Pramudono B. 
Published: November 2019

Abstract
It is necessary to develop a surfactant production process using environmentally friendly raw materials and products. For raw materials such as surfactants are carbohydrate-based material utilization example, glucose, which is reacted with tert-butanol, to form tert-butyl glycoside (TBG). This study aims to obtain the optimum conditions TBG production process of acetalization reactions, glucose and tert-butanol, catalyst the para toluene sulfonic acid using response surface method to reach optimum yield TBG. The independent variable used is the mole ratio of glucose with tert-butanol, percent of the catalyst and a temperature. Optimization results obtained optimum conditions of mole ratios of 1: 5.06; 2.87 percent of the catalyst and the temperature of 71.21 °C with a TBG yield of 99.13%, with a TBG content of 61.2 %. The optimum process conditions are verified to strengthen the model equations obtained by the response surface method. Based on the Hydrophilic-Lipophilic Balance value of the surfactant TBG is 4.60, then these surfactants can be used as an emulsifier of water-in-oil.
Production of solketal (2,2-Dimethyl-1,3-dioxolane-4-methanol) from glycerol and acetone by using homogenous acidic catalyst at the boiling temperature (preliminarry study)
Authors: Mahreni  , Marnoto Tjukup , Nur Muhamad Maulana Azimatun 
Published: November 2019

Abstract
Currently, solketal is produced from glycerol and acetone by using heterogeneous catalyst. However, a solid heterogeneous catalyst is not preferable since water contained in the glycerol, is adsorbed on the surface of the catalyst. Water could act as inhibitor in the reaction and lowering the activity of the catalyst. Therefore, homogenous acid catalyst is proposed to avoid the inhibition during the reaction. The aim of this research was to utilize sulphuric acid as the homogenous acid catalyst, to explore the effect of the mole ratio glycerol:acetone to the conversion, and determine the entrophy and entaphy of the reaction . The process was carried out in a three neck reactor equipped with a heater, temperature control, cooler and stirrer. The reaction conditions were set at a constant boiling temperature, the reaction time was varied at 4 - 12 h, and the mole ratio of acetone to glycerol was varied in the range of 2:1 - 7: 1. Results indicated that the highest conversion (>80 %) was recorded at 62°C, 10 h, and 6.9:1 mole ratio. The conversion of glycerol to solketal was influenced by mole ratio which is consistent to Lecatelier principle. From the entropy ΔS =280.02 J. mole K−1) and enthalpy ΔH= 95.948 J. mole−1), it can be concluded that the reaction of solketal formation was exothermic.
Response surface methodology optimization of α-mangostin extraction using betaine-1,2-propanediol deep eutectic solvent
Authors: Mulia Kamarza , Faisal Pane Irfan , Krisanti Elsa 
Published: November 2019

Abstract
Mangosteen pericarp contains α-mangostin, the most abundant xanthone that is useful as an antioxidant. Deep eutectic solvent (DES) was used in this study as a green solvent for extraction of α-mangostin. Our previous study shows that a DES, consisting of betaine as the hydrogen bond acceptor and 1,2-propanediol as the hydrogen bond donor, having the highest extraction yields compared to other betain-based DESs. In this study, the operating condition of the solvent extraction process has been optimized using the response surface methodology approach, based on the Box-Behnken design. The highest calculated α-mangostin extraction yield obtained was 4.2% (w/w), corresponding to an extraction temperature of 56.5 °C, mangosteen powder to DES mass ratio of 0.12, and extraction time of 6.9 hours. The optimum temperature was found to be the combined effect of enhanced leaching of the mangosteen pericarp matrix by the DES and α-mangostin degradation at higher temperatures.
Production of natural colorant powder from Clitoria ternatea l. using tray dryer which is dehumidified by zeolite
Authors: Mauludifia F , Astrinia S D , Meiranti K A , Djaeni M 
Published: November 2019

Abstract
One of food additives that are usually added to food is coloring agents. The use of synthetic colorant in food products often causes health problems. Telang flowers, or Clitoria ternatea L., have blue color that indicates the presence of anthocyanins. Anthocyanin is a flavonoid compound that has positive health benefits. Referring to this, the flowers can potentially become natural coloring agents. This research aims to examine the effect of pH on anthocyanins, the effect of maltodextrin concentration and temperature on water content. So that the best conditions are obtained for the drying process and obtained powder that has anthocyanin content with low water content. The research was conducted in several stages, namely extraction, drying and analysis of results. The extract is varied in its pH to obtain pH with highest anthocyanin. Drying was carried out with variations in maltodextrin concentrations of 0 and 8%, and temperatures of 40, 60 and 80°C. Water content analysis for 120 minutes every 10 minutes. The results showed that at pH 2, the highest total anthocyanin was obtained. The higher the drying temperature and maltodextrin concentration that is added, the time needed to dry the extract will be faster. Lower moisture content is produced with higher maltodextrin concentration and temperature.
Effectiveness of Eugenol as An Antibacterial Toward Staphylococcus epidermidis
Authors: Firyanto R , Fatarina P E , Azizah N 
Published: November 2019

Abstract
Eugenol is generally used as raw materials of perfumes, but now eugenol was developed as an antioxidant, antifungal, antibacterial and antiseptic. This study aims to determine the effect of eugenol concentration and pH and the effectiveness of eugenol as an antibacterial against Staphylococcus epidermidis. The experiments were carried out at concentrations of 1%, 2%, 4%, 6% and 8% with pH 6, 7 and 8. Data were collected and analyzed by two-way ANOVA method with interaction level of 5% (α = 0.05). The results showed that eugenol has an antibacterial effect in inhibiting the growth of bacteria Staphylococcus Epidermidis and included in the category of strong to very strong antibacterial. The optimum yield diameter of the inhibitory zone is 22.27 mm, obtained at pH 8 and the concentration of eugenol is 8%.
Adsorption of Cobalt-60(II) on silica xerogel from rice husk
Authors: Kundari N.A. , Permadi M.G. , Megasari K. , Nurliati G. 
Published: November 2019

Abstract
The primary cooling water system of a nuclear reactor contains Co-60 which requires treatments to avoid adverse effects on society and the environment. Experiment of Co-60 adsorption by using silica xerogel has been done. This experiment was intended to study the isothermal adsorption equilibrium and to determine thermodynamic parameters. Silica xerogel was made from rice husk ash using sol-gel method. The prepared of silica xerogel has a specific surface area of 142.034 m2/g. The adsorption experiments were carried out in a batch wise until it reaches an equilibrium state with variation of the initial concentration and temperature. The results show that Co (II) adsorption by silica xerogel following the Langmuir isotherm than Fruendlich model. Based on the experiment at three different temperatures, the maximum adsorption capacities depend on the temperature there are 25.71; 26.25; and 26.81 mg/g successively at a temperature of 30; 35; and 40 °C. The thermodynamic parameters showed that the cobalt-60 adsorption process by silica xerogel is spontaneous and endothermic with values of ΔH 117.084 kJ / mol and ΔS 35.582 kJ/K/mol. The use of the silica xerogel on the adsorption of reactor cooling water system containing Co-60 showed a decreasing of activity of the waste until 85% from the initial activity. These results indicate that the silica xerogel can be utilized as material to treat radioactive liquid waste containing Co-60.
Design of Air Quality Monitoring System Based On Web Using Wireless Sensor Network
Authors: Purwanto P , Suryono S , Sunarno S 
Published: November 2019

Abstract
Air pollution (O3, SO2, CO, NOx, PM, and Pb) can have a severe impact on environmental damage and human health problems. Therefore, monitoring of pollutant levels in the air is essential to find out how much that gas levels can cause air pollution. In general, air quality monitoring is carried out using a conventional system. Inside the system requires large-sized equipment, long time for analysis, expensive, and with limited space resolution. It becomes inefficient, amid the development of technology that can carry out online monitoring, real-time, low cost, small size and a wide range of distance. The technology is known as the wireless sensor network system. The aim of this research is to design an air quality monitoring system using a Wireless Sensor Network (WSN) that can be accessed via the web and smartphone. The developing of WSN systems consist of two steps, are design and implementation device. The first step is done by assembling sensor nodes and hosting a web server. And after the device was finished, the next step is testing and calibrating of the system. The results of experiment show that the system is able to detect various air pollution, such as SO2, NOX, CO, and other environmental factors such as temperature, humidity and wind speed.