bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of Gold(III), Copper(II), Nickel(II) on Amino Silica Hybrid Coated Magnetite
Authors: Thahir M T , Nuryono N , Santosa S J
Published: May 2020

Selective adsorption of Au(III) in multimetal systems Au3+/Cu2+/Ni2+ on Amino-Silica Hybrid coated Magnetite (ASHM) has been studied. ASHM was synthesized via a sol-gel process using magnetite that was obtained through coprecipitation of Fe2+/Fe3+ salts mixture with NH4OH as precipitating solution, sodium silicate solution of rice husk ash as a precursor and 3-aminopropyltrimethoxysilane (APTMS) as a source of amino. Adsorption kinetics was determined by pseudo-first-order and pseudo-second-order model, while the adsorption isotherm was analyzed studied by the Langmuir and Freundlich models. FTIR characterizations showed that ASHM has been successfully synthesized, indicated by the appearance of characteristic frequency at 570 cm−1 was stretching vibrations of Fe-O-Si, and the frequency at 3424 cm−1 was stretching vibrations of N-H. Adsorption kinetics studies showed that the adsorption of Au(III) on ASHM fit to pseudo-second-order model with adsorption rate constant was 1.21x10−3 g.mg−1min−1. ASHM adsorbent showed a linear plot of the Langmuir isotherm model with the adsorption capacity of Au(III) was 102,04 mg/g. Adsorption on multimetal showed that Au(III), Cu(II), Ni(II) were adsorbed with chemical interaction on the ASHM with capacity adsorption of Au(III) was higher than that of Cu(II) and Ni(II). ASHM has high enough selectivity for Au(III) toward Cu(II) and Ni(II) ions.
Kinetics Adsorption of Strontium(II) by Silica Xerogel from Fly Ash
Authors: Kundari N A , Megasari K , Yusephin C
Published: May 2020

A study of liquid waste adsorption containing strontium was carried out using the adsorption method using silica xerogel adsorbent. Silica xerogel synthesized from coal fly ash using the sol-gel method, produces a specific surface area of 84.8884 m2/g. This study was intended to determine the appropriate kinetics law. Data were obtained by following changes in Sr concentration to the time of adsorption at temperature of 25 ºC and 35 ºC. The data obtained was matched with 5 kinetic models, namely zeroth order kinetics, first order, second order, pseudo first order, and pseudo second order. Based on data analysis by means of linear regression and the number of minimum sum squared of errors, the adsorption kinetics model that is suitable for the adsorption of strontium by silica xerogel is a pseudo second order. The reaction rate constant at 298 K and 308 K were 0.1023 g/mg/min and 0.0716 g/mg/min respectively. The value of the activation energy is negative so the higher the temperature, the lower the adsorption rate. It is indicate that the adsorption is reversible.
Magnetic and microwave absorption properties of Mn4+ doped barium-natural ferrites prepared by the modified solid-state reaction method
Authors: Luthfianti H. R. , Widanarto W. , Ghoshal S. K. , Effendi M. , Cahyanto W. T.
Published: May 2020

Microwave wide-spread results in electromagnetic interference, environmental pollution, and hazards for health, thus microwave absorber is immediately needed. Mn4+doped barium natural ferrites were synthesized using the modified solid-state reaction method, which is a combination of the sol-gel method and the solid-state reaction. Commercial Ba(NO3)2, MnO2 and natural Fe3O4 were used as raw materials. Structural, magnetic properties and microwave absorption of the barium ferrites were characterized using XRD, VSM, and VNA, respectively. The results reveal that phase of BaFe2.37Mn9.63O19 dominates the diffraction peaks with the average size of crystallite 23.74 nm after adding Mn4+ ions in the barium ferrites. Ms value of the barium ferrite decreases with increasing concentrations of Mn4+ due to the surface effect of the nanoparticle. The MBF3 exhibited excellent performance that absorbs all given microwave frequencies with RL
below -10 dB and bandwidth of 4 GHz compared to the other samples.
Prospect of dark matter searches in split SUSY models
Authors: Okada Nobuchika , Minh Tran Hieu
Published: May 2020

The results from the XENON1T/Panda-X and IceCube experiments have set severe upper limits on spin-independent (SI) and spin-dependent (SD) scattering cross section of weakly interacting massive particles on nuclei. In the framework of split supersymmetry scenario supported by the LHC constraints, we investigate the prospect of dark matter (DM) direct and indirect detection experiments. Assuming a relation among gaugino masses at the grand unification scale, we have specified the parameter regions that predict the right DM relic abundance as well as satisfy the constraints on SI and SD scattering cross sections of DM. In the case of universal gaugino masses, the XENON1T/Panda-X results have ruled out completely the well-tempered neutralino region. We have found that 200 times smaller than the current IceCube bound is the sensitivity limit that a future DM indirect detection experiment should have at least in order to have a certain impact beyond the current XENON1T/Panda-X results. The future results from XENON1T will be able to test a signification portion of the Higgsino-like region. Although there are points in the Higgsino-like region that cannot be reached by future DM detection experiments, direct production channels of neutralino/chargino can be used to test the model at the LHC/HL-HLC. In the case of non-universal gaugino masses, beside showing the allowed parameter space, we have specified the regions that can be tested at both future DM direct and indirect detection experiments. One of them are Higgsino-like region, while the others two predict a well mixed bino-wino DM. The DM properties in each region have been examined and demonstrated with a benchmark of-ino spectrum. Interestingly, points in the mixed bino-wino region with rather light chargino can be tested the LHC 14 TeV.
Decay of neutron with participation of the light vector boson X17
Authors: Tien Du Pham , Ai Viet Nguyen , Van Dat Nguyen
Published: May 2020

The recently discovered light vector boson X17 at ATOMKI can trigger new decay channels of neutron, which can be used to explain the neutron lifetime puzzle. In this article, we calculate all the possible decay widths and discuss the physical implications.
Thermal expansion of metals Cu, Au and Ag at higher temperature and under pressure.
Authors: Duy Tan Pham , Dinh Tam Pham , Duc Tinh Bui
Published: May 2020

The thermodynamic properties of metals are studied using the moment method in the statistical dynamics, which allows us to take into account the anharmonicity of thermal lattice vibrations, going beyond the quasi-harmonic approximation. Within the fourth-order moment approximation, the free energy, equation of state and thermal expansion of the metals with fcc structure are given explicitly in terms of the effective pair potentials and the second-and fourth-order vibrational coefficients. Applying to Cu, Au and Ag metals, we calculate these properties at higher temperature and under pressure in simple analytic form. Numerical results for the lattice spacing, linear thermal expansion coefficient, pressure-volume dependence of these metals in different temperatures and pressures agree with the experiments and got better calculations than other authors.
New analysis characterizing the dynamics heterogeneity and microstructure in liquid silicates
Authors: Thu Nhan Nguyen , Khac Hung Pham
Published: May 2020

We use molecular dynamics simulation to study liquid silicates at ambient pressure and temperature of 3500 K. New analysis on structure and dynamics is carried out using such characteristics as the rate of bond-breaking events, link-cluster function and different subnet types. We found that the structural heterogeneity exists in short and medium length scales. Namely, the local environments of cations are quite different. The parking of SiOx
in the silicate systems is also very different. Further, the simulation shows that during a moderate long time the melt has a two-domain structure consisting of separate immobile domains and a mobile domain. These domain types differ strongly in the atomic mobility and chemical composition. The simulation also gives clear evidences for dynamics heterogeneity (DH) in the melt and that the non-uniform spatial distribution of bond-breaking events is responsible for the DH.
Molecular dynamics simulation of microstructure and atom-level mechanism of crystallization pathway in iron nanoparticle
Authors: Trang G T T , Kien P H , Hung P K , Ha N T T
Published: May 2020

We use the molecular dynamics simulation to study iron nanoparticles (NP) which consist of 5000 atoms at temperatures of 450 and 850 K. The crystallization and structure evolution was analyzed through pair radial distribution function, transition to different x-types, with x is the bcc, fcc and hcp, ico, 14, 12, and dynamical structure parameters. Simulation results that at 450 K, NP contains a large number of ico-type atoms which play a role in preventing of crystallization. The crystallization happened when NP was annealed at 850 K for 40 ns. Transitions to bcc-type do not happen arbitrarily at any location in NP, but instead they are focused in a non-equilibrium region. We showed that the crystallization pathway includes intermediate states between amorphous and crystalline phases. Firstly, a large cluster of cryst-atom is formed in a middle layer of NP. Next, this cluster grows up and the parameter for this cluster increases rapidly. Finally, the cluster of cryst-atom is located in a well-equilibrium region covered a major part of NP. The structure of crystalline NP is strongly heterogeneous and consists of separate local structure regions.
Seasonal divergence between soil water availability and atmospheric moisture recorded in intra-annual tree-ring δ18O extremes
Authors: Xu Guobao , Liu Xiaohong , Sun Weizhen , Szejner Paul , Zeng Xiaomin , Yoshimura Kei , Trouet Valerie
Published: May 2020

Intra-annual variability of tree-ring oxygen stable isotopes (δ18O) can record seasonal climate variability and a tree’s ecophysiological response to it. Variability of sub-annual tree-ring δ18O maxima and minima, which usually occur in different parts of the growing season, may exhibit different climatic signals and can help in understanding past seasonal moisture conditions, especially in Asian monsoon areas. We developed minimum and maximum tree-ring δ18O series based on sub-annual tree-ring δ18O measurements of Pinus massoniana at a humid site in southeastern China. We found that interannual variability in minimum tree-ring δ18O is primarily controlled by the July–September soil water supply and source water δ18O, whereas the maximum latewood tree-ring δ18O is primarily controlled by the relative humidity (RH) in October. The maximum of variability of earlywood tree-ring δ18O records the RH of October of the previous year. We used minimum and maximum tree-ring δ18O to develop two reconstructions (1900–2014) of seasonal moisture availability. The summer soil water supply (July–September self-calibrated Palmer drought severity index) and the RH in fall show contrasting trends, which may be related to late-growing seasonal warming leading to a high vapor capacity and high atmospheric moisture. Our findings are valuable for research that aims to explore seasonal moisture changes under anthropogenic climate change and the ecological implications of such contrasting trends.
Functional role of pectin in the bakery technology
Authors: Donchenko L V , Sokol N V , Sanzharovskaya N S , Khrapko O P , Mikhaylova T A
Published: May 2020

Current problems of the quality of wheat flour bread were analyzed. Here we studied whether apple pectin can be used in production of bakery goods. The significance of such properties of pectin as solubility, swelling, viscosity, susceptibility to acid and enzymatic hydrolysis for technological process were determined. Pectin radioresistance and detoxifying properties are equally important. Results of investigation of the apple pectin effect on dough fermentation process and quality and sorption properties of wheat bread are presented. Experimental substantiation of the most rational way of introducing pectin into dough is provided. The effect of pectic substances on the process of acid accumulation during dough fermentation is confirmed. Investigations were performed using methods of testing baking quality. We confirmed that addition of apple pectin leads to intensification of biotechnological processes and provides high quality and sorption properties of finished products.
Study of drum mixer operation during feed mixture preparation
Authors: Fudin K , Teruchcov V , Savinykh P , Konovalov V , Cupschev A
Published: May 2020

The purpose of the studies was to check the applicability of the drum mixer for the preparation of concentrated feed mixtures and to identify the dependencies of the change of mixture quality and energy consumption for mixing in the drum mixer with bent flat blades with holes on the following parameters: drum inclination angle, the fraction of control component and mixing cycle. Adequate representative regression nonuniformity models of mixture and energy consumption for mixing are obtained depending on the drum axis inclination angle in the range of 15-35 degrees, mixing time up to 20 min and the fraction of control component from 1 to 20%. Extreme values are not present. The reduction of the drum inclination angle and increase of the mixing time improves the quality of the mixture, as well as significantly increases the energy consumption of mixing. As the fraction of the control component increases from 1% to 10%, the quality of the mixture improves. Further increase in the fraction of the control component has little effect on the quality of the mixture. The variation coefficient of the control component content is reduced to 19% with the fraction of the control component equal 10% or more. As the fraction of the component decreases, the quality of the mixture decreases to 21%. As the quality of the mixture improves, the energy consumption increases. Such drum mixer may be used to prepare pre-mixtures only regardless of the fraction of the control component. In order to prepare high-quality feed mixtures, it is necessary to modernize the blades and their setting parameters.
Modular aggregation functions performed by static inverters in autonomous power supply systems
Authors: Grigorash O V , Popov A Y , Uskov A E , Denisenko E A , Kvitko A V
Published: May 2020

Static power inverters (SPI) are important functional elements to provide efficiency and reliability for autonomous power supply systems (APSS). The paper proposes to improve technical and economic characteristics of APSS through modular aggregation functions and reduced number of power electronic devices constituting SPIs. The paper provides a generalized SPC topology and insights into its performance. It deals with some electric schematic diagrams for a controlled rectifier and a three-phase modular inverter, a three-phase voltage inverter based on two single-phase inverters and a single-phase-three-phase rotating-field transformer, as well as a chain diagram for a universal modular static power inverter. It is shown that modular aggregation functions of APSS static power inverters will improve reliability through back-up operations performed by the main functional units and assemblies, and reduce time intervals for their maintenance and repair. The efficiency of autonomous systems will be advanced due to a decrease in the total number of power electronic devices constituting SPIs. In addition, the level of electromagnetic interference generated by these devices will decrease. A significant technical and economic effect will be achieved by using universal modular static inverters in the APS systems, capable of passing energy flows back and forth in both directions and operating in various modes.
Analysis of multivariate assessment methods for effective location of renewable energy facilities
Authors: Kirichenko A S , Kirichenko E V
Published: May 2020

The article emphasizes the importance of a method for assessing the efficiency of power plants based on renewable energy sources. The key criteria of the main multivariate models were analyzed and prioritized. The main current methods including those using fuzzy logic were studied. The technical, economic and legal characteristics that maximize the choice of the optimal methodology for assessing the effectiveness were identified. The method was selected on the example of Krasnodar Territory.
Technology of sunflower cake preparation
Authors: Priporov I E , Kurasov V S , Samurganov E E
Published: May 2020

For the production of sunflower cake, various technologies, which need to be improved, are used; it will increase the nutritional value of the feed which is a topical problem. To make possible the quality assessment of the protein feed, when it is prepared with components from piles of sunflower seeds in real time, the process is carried out by using multimedia devices at the stage of clearing the pile of sunflower seeds, as well as milling the prepared feed. The uniform-pitch screw value of a serial extruder is directly proportional to the first winding pitch and inversely proportional to the number of winds. By increasing the flight screw constant number, the winding pitch decreases and the processed material becomes compact. Reduction of the winding pitch aliquot to the screw is carried out exponentially. The compression ratio of sunflower seed components to obtain protein feed of a cake form with a winding pitch decrease aliquot depends on the design parameters of the extruder screw, which enables to regulate the technological process of its preparation in crumbly and granular forms. It depends on the screw winding pitch with its number, and by increasing the screw winding pitch the compression ratio is decreased, and contrariwise, with decreasing screw winding pitch the compression ratio of the processed material (sunflower cake) is increased.
Improvement of the efficiency of sunflower cake grinding
Authors: Priporov I E , Kurasov V S , Samurganov E E
Published: May 2020

The provision of animals and poultry with complete feed balanced in nutrition according to productivity is one of the key conditions for additional production and improvement of livestock quality and increase of protein. An improved sunflower cake grinder was proposed based on the given grinding techniques, which eliminates a number of disadvantages typical for serial products. Taking into account huge volumes of ground fodders, the problem of improving these grinders in terms of reducing their energy consumption is quite relevant. Besides, all known grinders are not suitable for sunflower cake grinding due to its physical and mechanical properties compared to other fodders. The paper describes the motion of the prepared sunflower cake along the surface of the cutting edge of knives in the form of a curved triangle of Archimedes arbelos with saw teeth in order to obtain it in a granular form. The Russian Patent 2648392 was obtained for the proposed design of the grinder, which allows expanding functional capabilities, reducing energy consumption of the process and improving the quality of grinding sunflower cake, which cannot be made by similar technical facilities. The knives in the grinder can be adapted for different fodder, both in granulated and dispersed form due to adjustment of distance between them depending on dimensions of processed material, which perform sliding cutting thus improving the efficiency of technological process. The obtained efficiency formula of the improved grinder allows increasing it depending on its design parameters and physical and mechanical properties of the material.
Methodology for simplified calculation of filter parameters of static power converters
Authors: Sobol A N , Bogdan A V , Uskov A E , Denisenko E A
Published: May 2020

Currently, passive L-shaped LC filters are widely used in static power converters. There are a lot of methods for calculating filter parameters, but they are complex. In addition, at the stage of experimental studies, it is necessary to refine the parameters to ensure required electromagnetic compatibility of the functional elements of the system. A simplified method for calculating the parameters of output and input filters of static electric power converters was developed. It can be used to evaluate the efficiency of converters. Filter calculations of AC and DC converters are not different, since the ripple coefficient and the harmonic coefficient are equal. The first one assesses quality of output voltage of AC converters, and the second one assesses quality of output voltage of DC converters. The method is based on the requirements ensuring minimum mass, continuity of current in the load, and high quality of output voltage. These requirements are met under conditions discussed in the article.
Kinematics and parameters for spiral-helical machinery unit used for secondary tillage
Authors: Nuriev L M , Yakhin S M , Aliakberov I I , Galiev I G , Sinitsky S S
Published: May 2020

To improve the quality of pre-sowing/secondary tillage, the Kazan State Agrarian University has developed a soil-tillage machinery unit that, unlike other tools, contains a helical spiral and needle ellipsoid disks coaxially mounted on a horizontal shaft. A passive helical spiral creates a compacted seed bed at the depth of seed placement. Needle-shaped ellipsoidal disks are active and they provide mulching of the surface soil layer. The paper presents the parametric equations (derived in the analytical way) of some motion points that are placed on the cutting blade of a helical spiral. Also, we introduce the equations applied to determine the velocity of the motion points and accelerations, which together allow us to analyze how the machinery working body interacts with soil. Theoretical connections are also given to substantiate the main structural parameters of a spiral-helical machinery unit.
Substantiation of criteria and methods for estimating efficiency of the electric impulse process of plant material
Authors: Yudaev I V , Daus Yu V , Kokurin R G
Published: May 2020

One of the most effective ways to prepare for extracting or removing intracellular fluid from plant material is its electric impulse treatment at initial processing stage before squeezing juice, dehydrating raw materials, drying materials, etc. As the parameters and modes that determine this process can be identified only experimentally, a device including a high-voltage impulse generator was designed. Plant tissue damage degree was assessed by changing resistance and phase shift. Intensive juice extraction was observed when high-voltage impulses in the amount of up to 100 units were supplied to plant material. With continued processing and increase in the number of impact impulses, the intensity of juice yield decreased, and the expended energy was spent on heating the plant material. The evaluation method based on quantitative analysis of pulse shape of flowing measuring current is proposed. The designed digital control device allows confirming the dependence of measured electrophysical parameters on changes occurring in plant material caused by electric impulse processing. The designed algorithm can be used as the basis of automatic control system operation for electroimpulse processing of plant materials before pressing.
Analysis of PM10 in urban and rural environment in Sumatra Island over the past half-decade
Authors: Khoir Aulia N , Suradi  , Kurdiyan  , Ahmad Mizani , Nurhayati Hanifah
Published: May 2020

Particulate Matter 10 (PM10) is an inhalable particle with a diameter smaller than 10 μm that disrupt the health of human respiratory. The distribution of PM10 varies depending on the region. This study aims to analyze the temporal distribution of PM10 in Sumatra Island, Indonesia, as one of the forest fires prone areas that affect neighboring countries, over the past half-decade. Study location was devided into two, Pekanbaru, Medan, Batam, and Palembang represent urban; and Jambi and Aceh represent rural areas, as we want to see the difference of variation of PM10 between two different locations of pollution source. In general, the results showed that the average PM10 concentration throughout the past half-decade was below the value threshold in all regions. The monthly PM10 concentration in rural areas is below the threshold except in Jambi, a monthly concentration above the threshold is in October. While the monthly PM10 concentration in urban areas tends to be above the threshold except for Batam and Pekanbaru. The monthly concentration of PM10 above the threshold occurs in Medan and Palembang in October. For trends in the rural and urban area, it shows different. Pekanbaru and Palembang which are located in urban area has significant decrease trend of concentration. For diurnal, the hourly average value tends to have different pattern in both urban and rural areas. PM10 concentrations in urban areas tend to be low in the morning and high during the day and rise again at night. The frequency of PM10 concentration above the threshold which is >10% occurrences is only in Medan and Palembang. Others have less than 10% occurrences of the frequency of PM10 concentration below the threshold.
Chemical characteristics and health risks of trace metals in PM2.5 from firework/firecracker burning during the Spring Festival in North China
Authors: Hao Yufang , Meng Xiangpeng , Yu Xuepu , Lei Mingli , Li Wenjun , Yang Wenwen , Shi Fangtian , Xie Shaodong
Published: May 2020

Firework/firecracker (FF) burning can significantly deteriorate air quality, whereas little is known about its influences on the elemental composition and associated health risks. Fine particles (PM2.5) and trace elements were characterized based on a multi-site campaign at Chifeng, China around 2016 Chinese Spring Festival (SF). Severe pollution levels average of 57.70 μg m−3 were observed during the SF with maximum to 471.00 μg m−3 shortly after the intensive FF activities. Largely enhanced PM2.5-bound metals were found in both urban and rural sites especially for K (8.27±5.36 μg m−3) and Al (2.36±1.41 μg m−3). Ba and Sr as the tracer of fireworks also increased more than 20-fold compared to non-SF period. Accordingly, FF burning factor identified via PMF model contributed significantly to the total elemental mass (71.34±24.94%) during the SF. Its major impacts on both crustal elements as Al, Ca, K and heavy metals as Cr, Cu and Pb were both identified. Elevated non-cancer risks (0.76 to children, 0.11 to adults) and cancer risks (3.96 × 10−6) were assessed during the SF, with As, Cd, Pb exerted the most adverse threats. The FF burning contributed the second largest share of the health threats after coal combustion, accounted for 28.35% and 12.64% of non-cancer risks for children and adults, respectively, and 10.03% of cancer risks, respectively. This study provided scientific evidences for stricter firework/firecracker regulations to protect public health.
Speciated NMVOCs Emission Inventories from Industrial Sources in China and Spatial Patterns of Ozone Formation Potential in 2016
Authors: Simayi Maimaiti , Hao Yufang , Xie Shaodong
Published: May 2020

This paper compiled a new speciated NMVOCs emission inventory for the industrial sources at the county-level by using a bottom-up approach in 2016, as well as estimated the ozone formation potential (OFP) and investigated its spatial characteristics in China. Results indicated that the total NMVOCs emissions from industrial sources estimated as 21.04 Tg in 2016. The five major source categories including “production of VOCs”, “storage and transportation”, “industrial processes using VOCs as raw material”, “processes using VOCs-containing products”, and “industrial fossil fuel combustion processes” generated 1.92 Tg, 0.94 Tg, 6.54 Tg, 10.04 Tg, and 1.60 Tg VOCs, respectively, in 2016. According to our estimates, aromatics were the largest contributor of industrial NMVOCs emissions in 2016, accounting for 36% of total NMVOCs, followed by Alkanes (29%), OVOCs (22%), Alkenes (7%), Halocarbons (4%), and Alkynes (2%). Styrene, m/p-xylene, ethylbenzene, toluene, and ethyl acetate were the top five VOC species from industrial sources in terms of abundance in 2016. Aromatics have a high potential for ozone formation, and accounted for 70% of total OFP, followed by Alkenes (14%), Alkanes (10%), and OVOCs (6%). Styrene, p-xylene, toluene, ethylbenzene, 1,3-butadiene were the five species that had the largest potential to form ozone, and plastic industry, coke industry, household appliances industry, and architectural decoration were the key contributing sectors. The emissions displayed distinct spatial characteristics, with significantly higher emissions and OFPs in coastal regions than in other inland areas of China.
Indoor haze particulate control using knowledge graphs within self-optimizing HVAC control systems
Authors: Mugumya Kevin Luwemba , Wong Jing Ying , Chan Andy , Yip Chun-Chieh , Ghazy Shams
Published: May 2020

Transboundary haze pollution in South East Asia is posing a threat to conventional design of buildings yet indoor air pollution from haze particulate infiltration has still received less attention in Malaysia compared to haze pollution outdoors. Because of this minimal research effort, indoor building environments have increasingly become very complex environments for facility managers to monitor and control due to the corresponding growth in heterogeneity within building behavioural information and monitoring (sensory) systems. As a solution to this and part of an ongoing study, this paper presents the preliminary process of modelling heterogeneous building information related to indoor air quality (IAQ) (building envelope, sensors, contaminant properties, geometry, occupancy schedules and weather data) within modular and extensible semantic web knowledge graphs (KG). This work argues that this data model can preserve the existential and latent parametric relationships within such information therafter availing an accurate representation of the heterogeneous state-space in machine learning workflows of self-learning building monitors and controllers. Compared to the conventional homogenous feature vectors, KGs hold sufficient context-aware semantics for an algorithmic building control system to smartly monitor the IAQ and autonomously learn to adapt air handling units towards occupant comfort in an energy efficient manner. Specifically, this paper highlights the high-level implementation process of KGs within the deep Q-learning process of the aforementioned control systems. Finally, a brief discussion is provided on how this process reduces the complexity that facility managers face while operating their IAQ control systems followed by the conclusions and future work to be carried out in this study.
A simplified analytical model of ultrafine particle concentration within an indoor environment
Authors: Pini A , Grandoni L , Leuzzi G , Monti P , Bernardino A Di , Pelliccioni A , Gherardi M , Cattani G , Di Menno di Bucchianico A
Published: May 2020

Exposure to indoor fine and ultrafine particulate matter (PM) has been recognised as a fundamental problem as most people spend over 85% of their time indoor. Experimental data derived from a field campaign conducted in a confined environment have been used to investigate the physical mechanisms governing indoor-outdoor PM exchanges in different operating conditions, e.g. natural ventilation and infiltration. An analytical model based on the mass balance of PM has been used to estimate indoor fine and ultrafine PM concentration. Indoor-outdoor concentration ratio, penetration factor and air exchange rate have been estimated and related to the differential pressure measured at the openings.
Dust concentration and awareness of safety and health among orthopaedic clinic staffs in Hospital Kuala Lumpur, Malaysia
Authors: Bakar ZA , Rahman IA , Ithnin A
Published: May 2020

Objective: The study was carried out to determine the concentration of total dust from the orthopaedic casting materials exposed to personnel and working area. The determination of knowledge, attitude, and practices (KAP) regarding occupational safety and health (OSH) aspects also conducted. Increase dust concentration above the permissible limit (PEL) would decrease the health status among the staffs. Methods: This cross-sectional study was conducted at the orthopaedic clinic public hospital in Kuala Lumpur, Malaysia. Determination of total dust concentration was using a NIOSH Manual of Analytical Method (NMAM 0501) for 8 hours and a direct reading for 10 minutes. A set of questionnaires assessing the level of KAP related to OSH at the orthopaedic clinic was distributed. Results: The results of total dust concentration in the casting room are 3.402 ± 0.003 mg/m3 from area sampling and for the personal air sampling is 5.573 ± 0.040 mg/m3 which are below than 15 mg/m3 PEL. Percentage of KAP level of OSH in the orthopaedic clinic indicates knowledge (96.75%), attitude (83.7%) and practices (82.85%) respectively. However, this study found that the level of knowledge related to OSH at the orthopaedic clinic had significant relationships (p <0.05) with age, job titles and area of workplaces, while OSH attitudes in orthopaedic clinics had significant relationships (p <0.05) with job titles, use of personal protective equipment (PPE). Level of practice of OSH at orthopaedic clinics, there was significant relationship (p <0.05) with age, job titles and use of PPE. Conclusion: The risk to total dust concentration exposure in this study are relatively low, however, some literature suggested duration of exposure-response even though in the low concentration can be a predisposing factor toward to health occupational illnesses. Medical health surveillance should be implemented in every 6 months to monitor staff’s health status.
Design and performance of a low-cost atmospheric composition monitor for deployment in extreme environments
Authors: Carotenuto F. , Brilli L. , Gioli B. , Gualtieri G. , Martelli F. , Mazzola M. , Vagnoli C. , Viola A. , Zaldei A.
Published: May 2020

The Arctic is one critical environment for monitoring climate change as well as variations in background concentrations of atmospheric components. The associated logistic difficulties, though, make hard to deploy an extensive monitoring network of sensors, limiting long time-series to only sparse and costly point observations. Low-cost sensors are experiencing a widespread employment in research and monitoring applications and could be an interesting tool to deploy spatialized monitoring networks even in extreme environments. In this context, two CNR Labs (IBE and ISAC) made a long-term deployment of a prototypal low-cost sensor for atmospheric composition monitoring in the polar research village of Ny-Ålesund (Svalbard, Norway). In about one year of measurements the low-cost sensor showed: i) a good consistency in the data series with minimal data loss, ii) no significant requirements for maintenance and iii) the capability of capturing the main atmospheric trends of the Arctic lower troposphere.
Air-quality assessment over the world’s Most Ambitious Project, NEOM in Kingdom of Saudi Arabia
Authors: Dasari Hari Prasad , Desamsetti Srinivas , Langodan Sabique , Rama Krishna L.N.K , Singh Shyamcharan , Hoteit Ibrahim
Published: May 2020

NEOM is an under-development transnational city and economic zone spreading over an area of 26,500 sq.km along the northern Red Sea coast of Saudi Arabia, bordering Jordan and Egypt. This work analyzes the meteorological parameters and air pollution dispersion over the NEOM region based on observations and air-quality dispersion modeling. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was implemented to simulate air parcel trajectories, as well as transport, dispersion, chemical transformation, and deposition. To drive HYSPLIT, high-resolution meteorological data generated at 600 m resolution by downscaling ECMWF global reanalysis using the Weather Research and Forecasting (WRF) were used. The United Sates Environmental Protection Agency Air Pollutant Emission Factors 42 emission inventory was used to initialize HYSPLIT. A continuous three-year meteorological and air-quality data from WRF-HYSPLIT model is used to analyze the spatial and temporal distributions of air pollutants’ concentration over the NEOM region. Strong land and sea breezes resulting from the differential heating dominates the diurnal dispersion and distribution of pollutants in the NEOM region. The spatial distributions of the mean seasonal ambient air pollution dispersion show similar patterns, with relatively higher concentrations in spring and winter. This is more pronounced in the spatial distributions of the maximum concentrations of different pollutants, which show the maximum concentrations in the spring and winter due to lower boundary layer heights. The predicted maximum concentrations of NOx (∼40 μg/m3), SO2 (∼25 μg/m3), CO (∼10 μg/m3), VOC (∼0.05 μg/m3), and PMT (∼4 μg/m3) over the study region remain well below the National Air Quality standards recommended by the Saudi General Authority for Meteorology and Environment Protection and the Royal commission. Our analysis provides needed information to understand the state of the air quality over the NEOM region, providing fundamental contribution to the environment impact assessment and planning in the region.
Biomass Char Gasification with Carbon Dioxide As An Alternative Energy
Authors: Selvarajoo Anurita
Published: May 2020

Currently, the main energy source are fossil based fuel. Utilisation of conventional fossil fuel is contributing to greenhouse gas emissions which causes climate change. Attention to renewable energy sources has increased nowadays to reduce the high dependence on fossil fuel which is considered not renewable. Biomass seems to be a promising and environmental friendly feedstock that can be converted into useful products (biochar, bio-oil and syngas). One of the method to convert biochar to syngas is through the gasification technology. When biochar is reacted with gasifying agent like CO2 and H2O at high temperatures, syngas which is rich in hydrogen can be produced. The main objectives of this work are to study the gasification behaviour of pineapple peels in Thermogravimetric Analyzer (TGA) using CO2 as its gasifying agent. The effect of temperature towards char reactivity and carbon conversion were determined. In conclusion, this study provides information on utilisation of biomass waste as an energy source through gasification technology.
Needleless electrospinning system with wire spinneret: an alternative way to control morphology, size, and productivity of nanofibers
Authors: Prahasti Gian , Zulfi Akmal , Munir Muhammad Miftahul
Published: May 2020

Electrospinning is a versatile method to produce nanofibers. Electrospun nanofibers have been extensively used in many industrial applications such as wound dressing, sensor, protective clothing, and filters. However, producing nanofibers efficiently through a single-needle electrospinning technique is still challenging. In this study, a system of needleless electrospinning with a wire spinneret was utilized to produce Polyvinylpyrrolidone (PVP) nanofibers. Process parameters comprised concentration of solution, applied voltage, flow rate of solution, collection distance, and diameter of the wire spinneret were altered to examine morphology, diameter, and productivity of the produced fibers. SEM images showed that morphology of the produced fibers was affected by concentration of PVP solution. Moreover, diameter of the produced fibers could be varied by controlling the process parameters. Our needleless electrospinning system has proved to be more productive in producing fibers than the single-needle electrospinning system.
Number Theory: A Very Short Introduction
Authors: Wilson Robin
Published: May 2020

Number Theory: A Very Short Introduction explains the branch of mathematics primarily concerned with the counting numbers, 1, 2, 3, …. Long considered one of the most ‘beautiful’ areas of mathematics, number theory dates back over two millennia to the Ancient Greeks, but has seen some startling new developments in recent years. Trailblazers in the field include mathematicians Euclid of Alexandria, Pierre de Fermat, Leonhard Euler, and Carl Friedrich Gauss. Number theory has intrigued and attracted amateurs and professionals alike for thousands of years, appearing in both recreational contexts (puzzles) and practical concerns (cryptography). Some problems in number theory are easy, whereas others are notorious with no known solutions to date.
SCEBE: an efficient and scalable algorithm for genome-wide association studies on longitudinal outcomes with mixed-effects modeling
Authors: Yuan Min , Xu Xu Steven , Yang Yaning , Zhou Yinsheng , Li Yi , Xu Jinfeng , Pinheiro Jose ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: May 2020

Genome-wide association studies (GWAS) using longitudinal phenotypes collected over time is appealing due to the improvement of power. However, computation burden has been a challenge because of the complex algorithms for modeling the longitudinal data. Approximation methods based on empirical Bayesian estimates (EBEs) from mixed-effects modeling have been developed to expedite the analysis. However, our analysis demonstrated that bias in both association test and estimation for the existing EBE-based methods remains an issue. We propose an incredibly fast and unbiased method (simultaneous correction for EBE, SCEBE) that can correct the bias in the naive EBE approach and provide unbiased P-values and estimates of effect size. Through application to Alzheimer’s Disease Neuroimaging Initiative data with 6 414 695 single nucleotide polymorphisms, we demonstrated that SCEBE can efficiently perform large-scale GWAS with longitudinal outcomes, providing nearly 10 000 times improvement of computational efficiency and shortening the computation time from months to minutes. The SCEBE package and the example datasets are available at https://github.com/Myuan2019/SCEBE.
AnthOligo: automating the design of oligonucleotides for capture/enrichment technologies
Authors: Jayaraman Pushkala , Mosbruger Timothy , Hu Taishan , Tairis Nikolaos G , Wu Chao , Clark Peter M , D’Arcy Monica , Ferriola Deborah , Mackiewicz Katarzyna , Gai Xiaowu , Monos Dimitrios , Sarmady Mahdi
Published: May 2020

A number of methods have been devised to address the need for targeted genomic resequencing. One of these methods, region-specific extraction (RSE) is characterized by the capture of long DNA fragments (15–20 kb) by magnetic beads, after enzymatic extension of oligonucleotides hybridized to selected genomic regions. Facilitating the selection of the most appropriate capture oligos for targeting a region of interest, satisfying the properties of temperature (Tm) and entropy (ΔG), while minimizing the formation of primer-dimers in a pooled experiment, is therefore necessary. Manual design and selection of oligos becomes very challenging, complicated by factors such as length of the target region and number of targeted regions. Here we describe, AnthOligo, a web-based application developed to optimally automate the process of generation of oligo sequences used to target and capture the continuum of large and complex genomic regions. Apart from generating oligos for RSE, this program may have wider applications in the design of customizable internal oligos to be used as baits for gene panel analysis or even probes for large-scale comparative genomic hybridization array processes. AnthOligo was tested by capturing the Major Histocompatibility Complex (MHC) of a random sample.

The application provides users with a simple interface to upload an input file in BED format and customize parameters for each task. The task of probe design in AnthOligo commences when a user uploads an input file and concludes with the generation of a result-set containing an optimal set of region-specific oligos. AnthOligo is currently available as a public web application with URL: http://antholigo.chop.edu.

Supplementary information

Supplementary data are available at Bioinformatics online.
Viruses and esophageal cancer
Authors: Chang Carolyn , Worrell Stephanie G
Published: May 2020

Esophageal adenocarcinoma (EAC) has had the fastest increasing incidence of any solid tumor in the United States in the last 30 years. Long standing gastroesophageal reflux disease is a well-established risk factor with strong associations with obesity, alcohol and tobacco. However, there are likely additional contributing factors. Viruses such as human papillomavirus, ebstein-barr virus and herpes simplex virus have been implicated in the pathogenesis of esophageal cancer. This review will discuss the known literature linking viruses to esophageal adenocarcinoma and consider future relationships such as identifying prognostic and predictive molecular biomarkers to guide therapies.
Pregnancy-associated arterial dissections: a nationwide cohort study
Authors: Beyer Sebastian E , Dicks Andrew B , Shainker Scott A , Feinberg Loryn , Schermerhorn Marc L , Secemsky Eric A , Carroll Brett J
Published: May 2020

Aims

Pregnancy is a known risk factor for arterial dissection, which can result in significant morbidity and mortality in the peripartum period. However, little is known about the risk factors, timing, distribution, and outcomes of arterial dissections associated with pregnancy.

Methods and results

We included all women ≥12 years of age with hospitalizations associated with pregnancy and/or delivery in the Nationwide Readmissions Database between 2010 and 2015. The primary outcome was any dissection during pregnancy, delivery, or the postpartum period (42-days post-delivery). Secondary outcomes included timing of dissection, location of dissection, and in-hospital mortality. Among 18 151  897 pregnant patients, 993 (0.005%) patients were diagnosed with a pregnancy-related dissection. Risk factors included older age (32.8 vs. 28.0 years), multiple gestation (3.6% vs. 1.9%), gestational diabetes (14.3% vs. 0.2%), gestational hypertension (6.0% vs. 0.6%), and pre-eclampsia/eclampsia (2.7% vs. 0.4%), in addition to traditional cardiovascular risk factors. Of the 993 patients with dissection, 150 (15.1%) dissections occurred in the antepartum period, 232 (23.4%) were diagnosed during the admission for delivery, and 611 (61.5%) were diagnosed in the postpartum period. The most common locations for dissections were coronary (38.2%), vertebral (22.9%), aortic (19.8%), and carotid (19.5%). In-hospital mortality was 3.7% among pregnant patients with a dissection vs. <0.001% in patients without a dissection. Deaths were isolated to patients with an aortic (8.6%), coronary (4.2%), or supra-aortic (<2.5%) dissection.

Conclusion

Arterial dissections occurred in 5.5/100 000 hospitalized pregnant or postpartum women, most frequently in the postpartum period, and were associated with high mortality risk. The coronary arteries were most commonly involved. Pregnancy-related dissections were associated with traditional risk factors, as well as pregnancy-specific conditions.