bluuebunny/crossref_metadata_2025 huggingface dataset:
X-Ray Observation of a Magnetized Hot Gas Outflow in the Galactic Center Region
Authors: Nakashima Shinya , Koyama Katsuji , Wang Q. Daniel , Enokiya Rei
Published: April 2019

We report the discovery of a 1° scale X-ray plume in the northern Galactic Center (GC) region observed with Suzaku. The plume is located at (l, b) ∼ (0.°2, 0.°6), east of the radio lobe reported by previous studies. No significant X-ray excesses are found inside or to the west of the radio lobe. The spectrum of the plume exhibits strong emission lines from highly ionized Mg, Si, and S that are reproduced by a thin thermal plasma model with kT ∼ 0.7 keV and solar metallicity. There is no signature of non-equilibrium ionization. The unabsorbed surface brightness is 3 × 10−14 erg cm−2 s−1 arcmin−2 in the 1.5–3.0 keV band. Strong interstellar absorption in the soft X-ray band indicates that the plume is not a foreground source but is at the GC distance, giving a physical size of ∼100 pc, density of 0.1 cm−3, thermal pressure of 1 × 10−10 erg cm−3, mass of 600 M
⊙, and thermal energy of 7 × 1050 erg. From the apparent association with a polarized radio emission, we propose that the X-ray plume is a magnetized hot gas outflow from the GC.
Evolution and Spectral Response of a Steam Atmosphere for Early Earth with a Coupled Climate–Interior Model
Authors: Katyal N. , Nikolaou A. , Godolt M. , Grenfell J. L. , Tosi N. , Schreier F. , Rauer H.
Published: April 2019

The evolution of Earth’s early atmosphere and the emergence of habitable conditions on our planet are intricately coupled with the development and duration of the magma ocean (MO) phase during the early Hadean period (4–4.5 Ga). In this paper, we study the evolution of the steam atmosphere during the MO period. We obtain the outgoing longwave radiation (OLR) using the line-by-line radiative transfer code GARLIC. Our study suggests that an atmosphere consisting of pure H2O, built as a result of outgassing, extends the MO lifetime to several million years. The thermal emission as a function of the solidification timescale of an MO is shown. We study the effect of thermal dissociation of H2O at higher temperatures by applying atmospheric chemical equilibrium, which results in the formation of H2 and O2 during the early phase of the MO. A 1%–6% reduction in the OLR is seen. We also obtain the effective height of the atmosphere by calculating the transmission spectra for the whole duration of the MO. An atmosphere of depth 100 km is seen for pure water atmospheres. The effect of thermal dissociation on the effective height of the atmosphere is also shown. Due to the difference in the absorption behavior at different altitudes, the spectral features of H2 and O2 are seen at different altitudes of the atmosphere. Therefore, these species, along with H2O, have a significant contribution to the transmission spectra and could be useful for placing observational constraints on MO exoplanets.
Halo Concentrations and the New Baseline X-Ray Luminosity–Temperature and Mass Relations of Galaxy Clusters
Authors: Fujita Yutaka , Aung Han
Published: April 2019

The standard self-similar model of galaxy cluster formation predicts that the X-ray luminosity–temperature (L
X–T
X) relation of galaxy clusters should have been

L

X

∝

T

X

2

in absence of the baryonic physics, such as radiative cooling and feedback from stars and black holes. However, this baseline relation is predicted without considering the fact that the halo concentration and the characteristic density of clusters increases as their mass decreases, which is a consequence of hierarchical structure formation of the universe. Here, we show that the actual baseline relation should be

L

X

∝

T

X

α

, where α ∼ 1.7, instead of α = 2, given the mass dependence of the concentration and the fundamental plane relation of galaxy clusters. Numerical simulations show that α ∼ 1.6, which is consistent with the prediction. We also show that the baseline luminosity–mass (L
X–M
Δ) relation should have been

L

X

∝

M

Δ

β

, where β ∼ 1.1–1.2, in contrast with the conventional prediction (β = 4/3). In addition, some of the scatter in the L
X–M
Δ relation can be attributed to the scatter in the concentration–mass (c–M) relation. The confirmation of the shallow slope could be proof of hierarchical clustering. As an example, we show that the new baseline relations could be checked by studying the temperature or mass dependence of gas mass fraction of clusters. Moreover, the highest-temperature clusters would follow the shallow baseline relations if the influences of cool cores and cluster mergers are properly removed.
An Extremely Low-mass He White Dwarf Orbiting the Millisecond Pulsar J1342+2822B in the Globular Cluster M3
Authors: Cadelano M. , Ferraro F. R. , Istrate A. G. , Pallanca C. , Lanzoni B. , Freire P. C. C.
Published: April 2019

We report on the discovery of the companion star to the millisecond pulsar J1342+2822B in the globular cluster M3. We exploited a combination of near-ultraviolet and optical observations acquired with the Hubble Space Telescope in order to search for the optical counterparts to the known millisecond pulsars in this cluster. At a position in excellent agreement with that of the radio pulsar J1342+2822B (M3B), we have identified a blue and faint object (m
F275W ≈ 22.45) that, in the color–magnitude diagram of the cluster, is located in the region of He core white dwarfs (WDs). From the comparison of the observed magnitudes with theoretical cooling tracks we have estimated the physical properties of the companion star: it has a mass of only 0.19 ± 0.02 M
⊙, a surface temperature of (12 ± 1) × 103 K, and a cooling age of

1.0

−
0.3

+
0.2

Gyr. Its progenitor was likely a ∼0.84 M
⊙ star, and the bulk of the mass-transfer activity occurred during the subgiant branch phase. The companion mass, combined with the pulsar mass function, implies that this system is observed almost edge-on and that the neutron star (NS) has a mass of 1.1 ± 0.3 M
⊙, in agreement with the typical values measured for recycled NSs in these compact binary systems. We have also identified a candidate counterpart to the wide and eccentric binary millisecond pulsar J1342+2822D. It is another WD with a He core and a mass of 0.22 ± 0.2 M
⊙, implying that the system is observed at a high inclination angle and hosts a typical NS with a mass of 1.3 ± 0.3 M
⊙. At the moment, the large uncertainty on the radio position of this millisecond pulsar prevents us from robustly concluding that the detected star is its optical counterpart.
Filamentary Accretion Flows in the Infrared Dark Cloud G14.225–0.506 Revealed by ALMA
Authors: Chen Huei-Ru Vivien , Zhang Qizhou , Wright M. C. H. , Busquet Gemma , Lin Yuxin , Liu Hauyu Baobab , Olguin F. A. , Sanhueza Patricio , Nakamura Fumitaka , Palau Aina , Ohashi Satoshi , Tatematsu Ken’ichi , Liao Li-Wen
Published: April 2019

Filaments are ubiquitous structures in molecular clouds and play an important role in the mass assembly of stars. We present results of dynamical stability analyses for filaments in the infrared dark cloud G14.225−0.506, where a delayed onset of massive star formation was reported in the two hubs at the convergence of multiple filaments of parsec length. Full-synthesis imaging is performed with the Atacama Large Millimeter/submillimeter Array to map the

emission in two hub-filament systems with a spatial resolution of ∼0.034 pc. Kinematics are derived from a sophisticated spectral fitting algorithm that accounts for line blending, large optical depth, and multiple velocity components. We identify five velocity coherent filaments and derive their velocity gradients with principal component analysis. The mass accretion rates along the filaments are up to

and are significant enough to affect the hub dynamics within one freefall time (∼105 yr). The

filaments are in equilibrium with virial parameter α
vir ∼ 1.2. We compare α
vir measured in the

filaments,

filaments, 870 μm dense clumps, and 3 mm dense cores. The decreasing trend in α
vir with decreasing spatial scales persists, suggesting an increasingly important role of gravity at small scales. Meanwhile, α
vir also decreases with decreasing nonthermal motions. In combination with the absence of high-mass protostars and massive cores, our results are consistent with the global hierarchical collapse scenario.
Mode Selection Mechanism to Enable Effective Device-to-Device Communication System over Different Environments
Authors: Zenalden Feras , Hassan Suhaidi , Habbal Adib
Published: April 2019

Device-to-Device (D2D) communication is an important component of the 5G mobile networks. D2D communication enables users to communicate either directly without network assistance or with minimum signalling information through a base station (BS). Hence, D2D communication can enhance system capacity, increase spectral efficiency, improve throughput and reduce latency. One of the main challenges in D2D communications that when a potential D2D pair can switch between direct and conventional cellular communications, there lies a challenge in identifying D2D mode selection between communicating devices (i.e. a D2D pair). This paper aims to evaluate the mode selection mechanism in different environments (indoor, outdoor). The mode selection mechanism is proposed using multi-criteria for decision-making technique, the mode selection mechanism based on Simple Additive Weighting (SAW) algorithm is used to wisely connect and switch between the available modes. The evaluation of the proposed mechanism for indoor environment and outdoor environment shows better performance based on user preferences.
Detection of Social Media Exploitation via SMS and Camera
Authors: Adib Azhar Mohamad , Mohd Saudi Madihah , Ahmad Azuan , Abu Bakar Azreena
Published: April 2019

Internet users all over the world are highly exposed to social media exploitation, where they are vulnerable to be targeted by this cyber-attack. Furthermore, excessive use of social media leads to Internet Addiction Disorder (IAD). Fortunately, social media exploitation and IAD can be monitored and controlled closely based on user’s mobile phone surveillance features which are camera, SMS, audio, geolocation (GPS) and call log. Hence to overcome these challenges, this paper presents five (5) Application Programming Interfaces (APIs) and four (4) permissions for SMS and camera that are mostly and widely used with the social media applications. These 9 APIs and permissions matched with 2.7% of the APIs and permissions training dataset that are related with SMS and camera. This experiment was conducted by using hybrid analysis, which inclusive of static analysis and dynamic analysis, with 1926 training dataset from Brunswick. These 9 APIs and permissions, if being misused by the attacker, could lead to privacy concerns of a mobile device. The finding from this paper can be used as a guidance and reference for the formation of new mobile malware detection technique and modeling in future.
The fateful landing of the hoopoe
Authors: Humphrey Caroline
Published: April 2019

This paper analyses the omen as a particular technique by which human subjects attempt to understand the uncertainties and misfortunes of their lives by way of receiving signs from the world. This method folds a singular event into a social form, a stabilized way of perceiving and responding to intimations of something about to change in the future. It is argued that perceiving omens is a practice of cosmological engagement and hence that its character is different in monotheist environments from those in which the world is conceived to be composed of disparate and separate elements, such as in in Mongolian regions. In the latter, the things and beings in the world that produce, or ‘offer’, omens are equivalent agents to the people who receive them. Both agents come with temporal and spatial attributes that collide in the event of the omen.
A Practical Exploration of Cybersecurity Faculty Development With Microteaching
Authors: Burrell Darrell Norman , Dattola Ashley , Dawson Maurice E. , Nobles Calvin
Published: April 2019

The growth and development of cybersecurity jobs and careers have created a need for new skilled faculty that can effectively teach the appropriate content to students at all levels. Often instructors are hired based on their academic credentials and professional experience without the use of assessment and faculty development methods to discover if these instructors can teach effectively or even improve the way they teach. Effective instructors have the ability constructively adjust teaching approaches when students are excelling or struggling based on skillful observation and constant assessment. If a student learns something with great ease, perhaps that approach would be of benefit to others. Part of what helps novices develop expertise here is their explicit attempt to understand how and why something works for students. The implementation and use of microteaching can provide a quality improvement approach to help cybersecurity instructors on all levels improve their ability to teach effectively.
Turning a Person Into a Brand
Authors: Zaman Halima
Published: April 2019

A person's turning into a brand means his entire process of becoming a distinguished personality in terms of career or other extraordinary talent. The main purpose of the study is to identify the brand personality traits in a musician and also to identify the scopes and the limitations in the past and future he had and will have being turned into a distinct brand personality. The study has shown the elements of sincerity, competence and sophistication of brand personality traits based on a particular musician. The study also discussed the scopes and limitations of a musician while turning into and being brand. Measuring the existence of the brand elements like memorable, likable, meaningful, adoptable, and so forth in a musician is also a concern of the study. The reason behind focusing on a musician's turning into a brand is to demonstrate the knowledge regarding personal branding and make people learn via this study that a person can be a brand on the basis of his perseverance and hard work regardless of how often obstacles occur in his life. The researchers have attempted to make a contribution to different branding issues and personal branding and shift people's perspective regarding study from product or service to a human behavior or personality.
Development and Validation of an Instrument to Measure Student Perceived E-Learning Service Quality
Authors: Pham Long , Kim Kioh , Walker Bruce , DeNardin Thomas , Le Hanh
Published: April 2019

While universities have been trying to focus their resources and attention on improving e-learning, many universities seem to be lagging behind students' increasing demands and expectations. In order to sustainably grow in an increasingly competitive e-learning environment, it is clear that universities must provide e-learning students with high quality services. To do this, universities are required to understand the attributes that e-learning students use to evaluate service quality. Unfortunately, little research on e-learning service quality has been conducted. This study developed and validated an instrument to measure student perceived e-learning service quality. Based on the relevant literature review and using responses from 1,232 e-learning students, the authors validated a three-factor e-learning service quality instrument involving e-learning system quality, e-learning instructor and course materials quality, and e-learning administrative and support service quality. Among these three factors, e-learning system quality makes the highest contribution to overall e-learning service quality, followed by e-learning instructor and course materials quality, and e-learning administrative and support service quality. This scale provides a useful measurement for researchers who wish to measure e-learning service quality and for university administrators and managers who want to enhance universities' e-learning servie quality.
A Cross Segment Analysis of Performance Variables of General Insurance Players in India
Authors: Rao T. Joji
Published: April 2019

The general insurance sector has been dynamically changing and upgrading its business operations in the field of product development, product pricing, underwriting, actuary, claims management, risk management, asset and liability management, reinsurance and customer relationship management to be in line with ever changing regulatory and non-regulatory business norms over the years. These changes arise out of increased emphasis on liberalization and open market systems has transformed the orientation of domestic general insurance markets from that of sellers to a buyer's market. In the past two decades of post privatization operations, the sector has witnessed many challenges in terms of performance. The present study attempts to provide an insight into the behavior of the variables, which determines the performance of general insurance business in India. The formulation of econometric models based on the behavior of the variables influencing the performance of general insurance business in India across the segments of fire marine and miscellaneous will facilitate better decision-making and risk management processes of the players in the industry. The findings of the study are likely to help the policy formulators in bringing needed modifications to the existing policy and provisions to give further boost to the industry.
Influence of Personality Traits and Social Conformity on Impulsive Buying Tendency
Authors: Parsad Chandan , Prashar Sanjeev , Tata Vijay Sai
Published: April 2019

Employing eight personality traits as suggested by Mowen, this study attempts to decipher the relationships these traits have with social conformity and impulsive buying tendency and between social conformity and impulsive buying tendency within one integrated framework. With data collected from 386 respondents, the article examines the relationship of personality traits using a 3M Model with social conformity and impulsive tendency of shoppers, and also determines the association between normative social influence and instantaneous urge to buy. The findings reveal that personality traits - conscientiousness, materialism and body needs have positive association with social conformity, whereas openness to experience is negatively associated with social conformity. With respect to impulsive buying tendency, neuroticism, materialism and arousal have positive relationships. The results also reflect positive affect of social conformity on impulsive buying tendency. These finding, along with research implications have enhanced the existing literature.
Monitor and Detect Suspicious Transactions With Database Forensic Analysis
Authors: Khanuja Harmeet Kaur , Adane Dattatraya
Published: April 2019

The extensive usage of web has given rise to financially motivated illegal covert online transactions. So the digital investigators have approached databases for investigating undetected illegal transactions. The authors here have designed and developed a methodology to find the illegal financial transactions through the database logs. The objective is to monitor database transactions for detecting and reporting risk level of suspicious transactions. Initially, the process extracts SQL transactions from logs of different database systems, then transforms and loads them separately in uniform XML format which gives the transaction records and its metadata. The transaction records are processed with well-defined rules to get outliers present as suspicious transactions. This gives the initial belief of the transactions to be suspicious. The belief value of transactions is further rationalised using Dempster-Shafer's theory. This verifies the uncertainty and risk level of the suspected transactions to assure occurrences of fraud transactions.
ICT R&D and Technology Knowledge Flows in Korea
Authors: Jung Woo-Jin , Lee Sang-Yong Tom
Published: April 2019

This study measured the R&D outcomes of Korea's firms by analyzing the changes and patterns of technology knowledge flows and tried to see whether the outcomes of ICT R&D were better than those of non-ICT R&D. Using the registered patent data from 2008 and 2009, the authors computed the technology cycle time (TCT) and various centrality indexes with social network analysis (SNA), a popular method in patent citation analyses (PCA). In particular, the authors developed a technology spillover network and industry absorption network for the SNA. Having done these analyses, this study additionally conducted a confirmatory statistical test to compare ICT R&D with non-ICT R&D in terms of their performances. The authors found that Korea's ICT R&D has achieved higher levels of technology development speed, technology spillover and industry absorption when compared to non-ICT segments. The authors were also able to determine which particular ICT R&D is in an important position in terms of technology knowledge flows.
Optical Transparent and Hydrophobic Properties of TEOS/OTES Hybrid Materials by Sol-Gel Processing
Authors: Pantulap Usanee , Petchareanmongkol Benjamon , Kaewdang Waraporn , Tapasa Kanit
Published: April 2019

The objective of this project was to develop the hydrophobic film for self-cleaning glasses. The effects of octyltriethoxysilane (OTES) additions to hydrolysis of tetraethylorthosilicate (TEOS) on hydrophobic and optically transparent properties were studied. The film was prepared by sol-gel method from the precursors namely, TESO, OTES, isopropanol alcohol (IPA), and deionized water (DI). The sols for coating were obtained with TEOS/OTES ratio of 50:50 to 99:1. The sols were deposited on a commercial glass and dried at 60oC for an hour. After drying, the film properties were characterized by fourier transform infrared spectroscopy (FTIR), UV-VIS Spectrophotometer, x-Ray Diffractometer (XRD), atomic force microscope (AFM), optical microscopy and contact angle meter. It was found that contact angles of the hybrid films increased with the OTES addition, reaching a maximum at 10 wt.%, and the contact angle values were the same as for further addition. The light transmittance was rather stable with increasing amounts of OTES. For the optimized condition, the water contact angle of 108o and light transmittance of 91%, was obtained with TEOS/OTES ratio of 90:10.
Tribological Properties of Sintered Graphite-Steel Composites Containing Lignite Bottom Ash
Authors: Auechalitanukul Chiraporn , McCuiston Ryan , Saorerk Chindanai , Limsombutanan Thiti , Jindajia Ekachai
Published: April 2019

Lignite bottom ash is an industrial byproduct from the combustion of lignite coal in electric power plants. The ash is composed of various hard metal oxides, and therefore may be suitable for use as a low cost friction modifier in friction materials. This research studied the effect of lignite bottom ash additions (up to 20 weight percent) on the tribological properties of a graphite-steel composite (5 weight percent graphite and 95 weight percent high carbon steel). The powder compositions were uniaxially pressed with 300 MPa applied pressure to produce disc shaped samples. The samples were sintered at 1,100 °C for 30 minutes in a reducing atmosphere of 90 percent nitrogen and 10 percent hydrogen. The friction coefficients were measured using a ball-on-disc tribometer. It was found that the addition of bottom ash increased the friction coefficients of the samples due to the increased abrasiveness provided by the bottom ash. The density of the samples was reduced due to the lower theoretical density of the bottom ash compared to the steel that it replaced. The hardness of the samples were found to be independent of the amount of lignite bottom ash, possibly as a result of a hard particle reinforcement effect.
Effect of Waste-Derived Calcium Sulfate Additions on the Tribological Properties of Sintered Steel-Based Material
Authors: Auechalitanukul Chiraporn , McCuiston Ryan , Sukantowong Ton , Wachirapanee Wachira , Surmpakdeekul Treepak
Published: April 2019

This study examined the effect of waste-derived calcium sulfate additions (2 to 8 weight percent) on the tribological properties of a sintered high-carbon steel material, commonly used for frictional applications. The calcium sulfate powder was obtained by crushing and subsequent calcination of waste plaster molds previously used for slip casting of ceramics. Samples were made using the powder metallurgy method. Powder mixtures were uniaxially die compacted and sintered at 1,100°C for 30 minutes in a reducing atmosphere. It was found that the density of the samples decreased with increased amounts of calcium sulfate. This was due to the lower theoretical density of the calcium sulfate as well as volumetric expansion of the samples. Ball-on-disc tribological testing was performed at room temperature. The addition of calcium sulfate resulted in an increase of the kinetic friction coefficient. The measured wear volume was slightly reduced with the addition of calcium sulfate less than 6 weight percent, beyond which the wear increased. The hardness of the samples was reduced with the addition of calcium sulfate. Increased calcium sulfate content decreased the sample deformation resistance while increasing the kinetic friction coefficient and the wear. This was likely due to the microstructural changes of the samples, which will be discussed.
Effect of Sintering Temperature on Mechanical and Electrical Properties of Lead-Free Bi0.5(Na0.4K0.1)Ti0.98Zr0.02O3 Piezoelectric Ceramics
Authors: Butnoi Pichitchai , Manotham Supalak , Tunkasiri Tawee
Published: April 2019

Effect of sintering temperatures on phase formation, mechanical and electrical properties of lead-free Bi0.5(Na0.8K0.2)0.5Ti0.98Zr0.02O3 or BNKTZ piezoelectric ceramics were investigated. The BNKTZ ceramics were prepared via a conventional solid-state sintering technique under various sintering temperature range 1100-1150°C for 2 h. The phase formation and microstructure of the ceramics were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM) method, respectively. XRD analysis indicated that all samples exhibited a single perovskite structure and no secondary phase. SEM microscopy study revealed an increase in grain size with increasing sintering temperature. The maximum values of density and maximum dielectric constant of the ceramics sintered at 1125 °C were 5.79 g/cm3 and 3446, respectively. In addition, the ceramics sintered at 1125 °C showed highest mechanical properties (HV = 4.32 GPa, HK = 5.87 GPa, E = 143 GPa and KIC = 1.30 MPa.m1/2). The highest values of ferroelectric and piezoelectric were found at this sintering temperature.
Influence of Mechanical Activation on the Phase Formation in the Synthesis of Cordierite from Talc and Andalusite
Authors: Vairojanakit Chatcharin , Sinchai Sujarinee
Published: April 2019

Cordierite is known as a leading candidate material for many applications. In this study, mechanical activation assisted synthesis of cordierite using andalusite as a starting material was attempted and phase formation of powder obtained from the heat treatment of talc-andalusite-silica system was investigated. The stoichiometric composition of cordierite (2MgO·2Al2O3·5SiO2) was prepared and ground in planetary ball mill at the rotational speed of 300 and 500 rpm for 0, 30, 60 and 90 min. The powder mixtures were heat treated in air at the temperature ranging from 1150 to 1350°C for 2 hours. Thermal reaction, phase present and microstructure of the starting materials and synthesized products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It was found that cordierite phase increased with the grinding time and speed and synthesis temperature. The kinetics of phase formation in this system were also discussed.
Effects of SnO2-SiO2-MgO-Bi2O3-Y2O3 Additions on Liquid Phase Sintering Silicon Nitride
Authors: Wattanarach Sasijuta , Nilpairach Siripan , Mongkolkachit Charusporn , Pornphatdetaudom Thanataon , Wasanapiarnpong Thanakorn
Published: April 2019

Si3N4 ceramics were sintered at relatively low temperature of 1400-1650 °C with additives from the SnO2-SiO2-MgO-Bi2O3-Y2O3 system. The degree of densification, α-β transformation, mass loss and microstructure were measured as a function of additives composition, sintering temperature, and nitrogen gas pressure. Specimen prepared from 3 mass% SnO2, 3 mass% SiO2, 3 mass% MgO, 6 mass% Bi2O3, and 5 mass% Y2O3 as the sintering additive could be sintered to almost full density at relatively low temperature as 1550 °C for 2 h under ambient pressure of nitrogen atmosphere. The α-β transformation was not completed at this condition. The mass loss was relatively high due to the evaporation of SiO2, MgO and Bi2O3. However, the resulted dense materials have high bending strength.
Preparation and Properties of Composite Films from Poly(Butylene Succinate), Poly(Butylene Adipate-co-Terephthalate) and Zeolite
Authors: Hongsriphan Nattakarn , Viratchaiboot Nitinon , Indrasook Prechapol , Hanbuakaeo Sahapat
Published: April 2019

Poly(butylene succinate) (PBS) was blended with poly(butylene adipate-co-terephthalate) (PBAT) in weight ratios of 80/20 and 70/30 wt%. Zeolite4A and zeolite13X of 1, 2, and 3 wt% were added which polyethylene glycol (PEG) was used to improve compatibility. The blends and composites were compounded and extruded into thin films. Mechanical, thermal, and morphological properties were studied. Water absorption was also investigated. The results showed that adding PEG enhanced elongation at break of the PBS70/PBAT30 film due to plasticizing effect. Better miscibility between PBS and PBAT was observed after adding PEG. Nevertheless, zeolite particles reduced elongation at break of composite films. The composite films with zeolite13X had higher tensile strength but lower elongation at break than those with zeolite4A. The degree of crystallinity increased significantly in the PBS70/PBAT30 film. The 24-hour water absorption of the blends was higher than that of neat PBS film and was higher with respect to zeolite content.
Injection Moldable Poly(Lactic Acid)-Poly(Butylene Succinate)-Activated Carbon Composite Foams: Effects of PLA/PBS Ratios
Authors: Hrimchum Kittipong , Aussawasathien Darunee , Kajornprai Todsapol
Published: April 2019

Poly (lactic acid) (PLA)-poly (butylene succinate) (PBS)-activated carbon (AC) composites were foamed via an injection molding process. Azodicarbonamide (ADC) was used as a chemical blowing agent. The effect of PLA/PBS ratios (0/100, 10/90, 20/80, 30/70, 40/60, 50/50 wt% and vice versa) on the cell formation and properties of composite foams such as cellular structure, foam density (ρf), void fraction (Vf), cell density, melt flow index (MFI), thermal and mechanical properties and crystallinity were investigated. At same ADC and AC loadings (5 phr), PBS acted as nucleating sites for cell generation and expansion at low contents ( 40 wt%). However, the cell size had a tendency to decrease at high PBS concentrations (> 40 wt%). The cell density of composite foams was somewhat constant at PLA/PBS ratios up to 60/40 wt% and then continuously increased as the PBS dosage was higher than 40 wt%. The maximum reduction of foam density with the void fraction of 20% was obtained at the PLA/PBS ratio of 60/40. The melt viscosity of composite foams increased with the increase of PBS loadings. The tensile strength and Young’s modulus of composite foams decreased while the elongation at break and impact strength increased as the proportion of PBS increased. The cold crystallization temperature (Tcc) of PLA in the composite foam tended to decrease with the reduction of PLA contents while the melting temperatures (Tm) of PLA in composite foams fluctuated without any trend compared with those of the unfoamed PLA. The Tcc of PLA in composite foams could not be detected when the content of PBS was higher than 40 wt%. The crystallization temperature (Tc) and Tm of PBS in composite foams was almost unchanged for each PLA/PBS proportion compared with those of the unfoamed PBS. The crystallinity (Xc) of PLA in composite foams increased compared with the unfoamed PLA at PBS contents of 0-20 wt% due to the nucleating effect of PBS and AC. The Xc of PLA (at PBS > 20 wt%) and PBS in composite foams decreased with the reduction of each polymer.
Effect of Alumina Addition on the Rheological Behavior of Shear Thickening Fluids
Authors: Nuampakdee Natnicha , Sinchai Sujarinee , Gamonpilas Chaiwut
Published: April 2019

Shear thickening fluids (STF) have attracted much attention in many applications including body armor. In this study, suspensions of silica colloidal particles and polyethylene glycol fluid were prepared at varying volume fractions φ = 0.3 to 0.52 and their rheological behavior was investigated. It was found that the suspensions exhibited a Newtonian behavior for φ < 0.4, whilst a shear thinning followed by a thickening behavior could clearly be observed for φ > 0.4. Furthermore, the critical shear rates for the onset of shear thickening was found to decrease with increasing silica volume fraction but the corresponding critical shear stresses were independent of the volume fraction. To improve the ballistic protective performance, small amount of hard material particles, such as alumina, were added into the silica suspension of φ = 0.5. It was shown that the critical shear rates of the reinforced-STFs decreased with increasing volume fraction and decreasing alumina particle size. However, higher thickening ratio was observed for the alumina additive with agglomerated structure and this ratio increased with increasing alumina volume fraction.
Impact of Engine Oil’s Additives on Particulate Matter’s Micro-and Nanostructure Using Electron Microscopy Image Analysis
Authors: Koko Phyozin , Karin Preechar , Rungsritanapaisan Sippakorn , Tongsri Ruangdaj , Hanamura Katsunori
Published: April 2019

According to increasingly stringent emission regulations on particle emissions from automotive vehicles, a diesel engine must be equipped with diesel particulate filter (DPF) to trap the particulate matters (PMs) which can be harmful to human health. Morphology and chemical composition of particulate matters were successfully studied using electron microscopy and electron dispersive x-ray spectroscopy (EDS) analysis. Microstructure of particulate matters derived from diesel blending lubricating oil were not significant different compared to diesel PM. Nanostructure of soot is a spherical shape composed of curve line crystallites and the particle sizes were in the range of 10 – 60 nm while the metal oxide ash is composed of lattice fringes. Chemical composition analysis of EDS result showed that metallic additives from lubricating oil cannot be burned during combustion and might be transformed into metal oxide ash.
In Vitro Resorbability of 3D Printed Hydroxyapatite in Two Different pH Buffered Solutions
Authors: Thammarakcharoen Faungchat , Palanuruksa Phee , Suwanprateeb Jintamai
Published: April 2019

Resorability of 3D printed hydroxyapatite (3DP HA) in deionized water solution which was buffered with succinic acid-NaOH (pH 5.5) and Tris(hydroxymethyl aminomethane) (pH 7.4) for 1, 7, 14 and 28 days was carried out. Weight change and release of calcium (Ca) and phosphorus (P) were used to evaluate the sample resorption. It was found that the weight of samples soaking in both pH 5.5 and 7.4 solutions decreased with increasing soaking times, but the degree of decrease was greater at pH 5.5 than at pH 7.4. ICP-OES results showed that the release of Ca and P in both pH solutions increased with immersing times. The amount of Ca and P released at pH 5.5 was higher than at pH 7.4. Phase composition of the samples and the microstructure of the sample were characterized using XRD and SEM respectively. XRD analysis showed that hydroxyapatite (HA) and octacalcium phosphate (OCP) phases were found at the center of all samples, but the intensity of OCP peaks tended to decrease with increasing times. Only HA was found on the sample surface after immersion in both pH solutions at all soaking periods. After immersion, newly formed crystals were seen both at the center and/or on the surface of samples. These results suggested that pH could influence the resorption of the samples and also the formation of new calcium phosphate crystals.
Dual-Curing Polylactide for Resorbable Bone Cement
Authors: Channasanon Somruethai , Kaewkong Pakkanun , Tanodekaew Siriporn
Published: April 2019

Polymeric cement based on poly (methyl methacrylate) (PMMA) has been known as a common material for fixation of prostheses with the advantages of mechanical properties. However, one of drawbacks of PMMA cement is heat produced during polymerization. The elevating temperature during polymerization resulting from exothermic polymerization of MMA can cause bone cellular necrosis. Additionally, the residual MMA monomer after polymerization is an issue regarding the biocompatibility of cement. In this study, a resorbable cement based on polylactide (PLA) has been developed. Its physical, mechanical and biological properties were investigated as an alternative biocompatible bone cement. The dual-cured polylactide cements prepared by combining spherical powder of star-shaped and linear PLA blends with triethylene glycol dimethacrylate liquid were radically polymerized by UV-VIS light and self-curing methods. Flexural strength, maximum temperature during polymerization and biocompatibility via the percentages of cell viability using MTT assay of the dual-cured polylactide were determined to meet requirements for bone cement. The best flexural strength of 108 MPa was achieved from the cement composed of 80%-wt of star-shaped PLA with molecular weight (Mw) of 10770. The preparation of cement using paste/liquid mixing, in which the powder was allowed to wet in the liquid before mixing, significantly encouraged mechanical properties compared to powder/liquid mixing due to satisfactory solubility of PLA prior to polymerization. The amount of initiator/activator was studied to fine-tune the maximum temperature during polymerization. The maximum temperature during polymerization of the PLA cement was in the range of 80-90 degree Celsius and the percentage of osteogenic cell viability immediately after cement setting was 83 indicating a non-toxic material. Therefore, this PLA cement polymerized with a dual curing mode is promising for a resorbable bone cement.
Il dibattito in Bioetica - Il senso della Vita nella “Terminalità”. Curare e “prendersi cura” delle fragilità prenatali
Authors: Noia Giuseppe
Published: April 2019

Non disponibile / Not available
Topical steroids: Awareness and misuse among patients, pharmacists and general medical practitioner
Authors: Sheth Niral K. , Nair Pragya Ashok
Published: April 2019

Aims and Objectives:

(1) To determine the level of awareness among patients, pharmacists and general practitioners about commonly available topical steroids and its combinations.(2) To determine the source of recommendation/prescription of topical steroids and its combination creams.(3) To know and create awareness about the side effects of topical steroids in all the study groups.

Methods:

This was a prospective questionnaire-based study where three study groups, namely patients, pharmacists and general practitioners, were included. This study was approved by the institutional ethics committee. after ethical clearance. The patients who used topical steroids for dermatoses where it is an absolute contraindication, as well as those who developed side effects, were included in the study. ThoroughComplete cutaneous examination was done specifically to detect the side effects of steroids. Seminars were conducted and questionnaires were given to both the pharmacists and general practitioners of nearby areas. The questionnaire consisted of questions regarding their prescription and dispensing practices of topical steroids and its combinations.

Results:

Out of 95 patients seen, the most commonly used steroid molecule was clobetasol propionate 0.05% in 44 (46.3%) patients, the common source of recommendation was general practitioners in 36 (37.8%), the common indication was superficial dermatophytosis in 85 (89%) and the most common adverse effect was recurrence/increase in the extent of the infection in 72 (75.78%) patients. Out of total 44 general practitioners enrolled in the study, 22 (50%) were qualified allopathic medical practitioners and22 (50%) were homeopathic/ayurvedic doctors. Superficial dermatophytosis [19 (43.18%)] was the common dermatosis seen by them. While 29 (65.90%) preferred prescribing topical steroids or its combination, rest of them preferred plain steroid creams. Out of 179 pharmacists, 74 (41.34%) did not have appropriate knowledge of topical steroids, 35 (19.55%) were not aware that steroids are isschedule “H” drugs. Commonest molecule sold over the counterwas clobetasol propionate 0.05% by 74 (41.89%). The limitations of our study were small study group and short duration.

Conclusion:

As dermatologists, it is our responsibility, to correctly educate the society, particularly the non-dermatologist medical fraternity, about ethical and rational use of topical steroids.
Understanding atmospheric aerosol particles with improved particle identification and quantification by single-particle mass spectrometry
Authors: Shen Xiaoli , Saathoff Harald , Huang Wei , Mohr Claudia , Ramisetty Ramakrishna , Leisner Thomas
Published: April 2019

Abstract. Single-particle mass spectrometry (SPMS) is a widely used tool to determine
chemical composition and mixing state of aerosol particles in the atmosphere.
During a 6-week field campaign in summer 2016 at a rural site in the upper
Rhine valley, near the city of Karlsruhe in southwest Germany, ∼3.7×105 single particles were analysed using a laser ablation aerosol
particle time-of-flight mass spectrometer (LAAPTOF). Combining fuzzy
classification, marker peaks, typical peak ratios, and laboratory-based
reference spectra, seven major particle classes were identified. With the
precise particle identification and well-characterized laboratory-derived
overall detection efficiency (ODE) for this instrument, particle similarity
can be transferred into corrected number and mass fractions without the need
of a reference instrument in the field. Considering the entire measurement
period, aged-biomass-burning and soil-dust-like particles dominated the particle number
(45.0 % number fraction) and mass (31.8 % mass fraction);
sodium-salt-like particles were the second lowest in number (3.4 %) but
the second dominating class in terms of particle mass (30.1 %). This
difference demonstrates the crucial role of particle number counts'
correction for mass quantification using SPMS data. Using corrections for
size-resolved and chemically resolved ODE, the total mass of the particles
measured by LAAPTOF accounts for 23 %–68 % of the total mass
measured by an aerosol mass spectrometer (AMS) depending on the measurement
periods. These two mass spectrometers show a good correlation
(Pearson's correlation coefficient γ>0.6) regarding total mass for more than 85 % of the measurement time,
indicating non-refractory species measured by AMS may originate from
particles consisting of internally mixed non-refractory and refractory
components. In addition, specific relationships of LAAPTOF ion intensities
and AMS mass concentrations for non-refractory compounds were found for
specific measurement periods, especially for the fraction of
org ∕ (org + nitrate). Furthermore, our approach allows the
non-refractory compounds measured by AMS to be assigned to different particle
classes. Overall AMS nitrate mainly arose from sodium-salt-like particles,
while aged-biomass-burning particles were dominant during events with high
organic aerosol particle concentrations.
Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna
Authors: Levick Shaun R. , Richards Anna E. , Cook Garry D. , Schatz Jon , Guderle Marcus , Williams Richard J. , Subedi Parash , Trumbore Susan E. , Andersen Alan N.
Published: April 2019

Abstract. Fire regimes across the globe have been altered through changes in land use,
land management, and climate conditions. Understanding how these modified fire
regimes impact vegetation structure and dynamics is essential for informed
biodiversity conservation and carbon management in savanna ecosystems. We
used a fire experiment at the Territory Wildlife Park (TWP), northern
Australia, to investigate the consequences of altered fire regimes for
vertical habitat structure and above-ground carbon storage. We mapped
vegetation three-dimensional (3-D) structure in high spatial resolution with
airborne lidar across 18 replicated 1 ha plots of varying fire frequency
and season treatments. We used lidar-derived canopy height and cover metrics
to extrapolate field-based measures of woody biomass to the full extent of
the experimental site (R2=0.82, RMSE = 7.35 t C ha−1) and
analysed differences in above-ground carbon storage and canopy structure among
treatments. Woody canopy cover and biomass were highest in the absence of
fire (76 % and 39.8 t C ha−1) and lowest in plots burnt late in
the dry season on a biennial basis (42 % and 18.2 t C ha−1).
Woody canopy vertical profiles differed among all six fire treatments, with
the greatest divergence in height classes <5 m. The magnitude of fire effects
on vegetation structure varied along the environmental gradient underpinning
the experiment, with less reduction in biomass in plots with deeper soils.
Our results highlight the large extent to which fire management can shape
woody structural patterns in savanna landscapes, even over time frames as
short as a decade. The structural profile changes shown here, and the
quantification of carbon reduction under late dry season burning, have
important implications for habitat conservation, carbon sequestration, and
emission reduction initiatives in the region.
Simulating the atmospheric CO2 concentration across the heterogeneous landscape of Denmark using a coupled atmosphere–biosphere mesoscale model system
Authors: Lansø Anne Sofie , Smallman Thomas Luke , Christensen Jesper Heile , Williams Mathew , Pilegaard Kim , Sørensen Lise-Lotte , Geels Camilla
Published: April 2019

Abstract. Although coastal regions only amount to 7 % of the global oceans, their
contribution to the global oceanic air–sea CO2 exchange is
proportionally larger, with fluxes in some estuaries being similar in
magnitude to terrestrial surface fluxes of CO2. Across a heterogeneous surface consisting of a coastal marginal sea with
estuarine properties and varied land mosaics, the surface fluxes of
CO2 from both marine areas and terrestrial surfaces were investigated
in this study together with their impact in atmospheric CO2
concentrations by the usage of a high-resolution modelling framework. The
simulated terrestrial fluxes across the study region of Denmark experienced
an east–west gradient corresponding to the distribution of the land cover
classification, their biological activity and the urbanised areas. Annually,
the Danish terrestrial surface had an uptake of approximately
−7000 GgC yr−1. While the marine fluxes from the North Sea and the
Danish inner waters were smaller annually, with about −1800 and
1300 GgC yr−1, their sizes are comparable to annual terrestrial fluxes
from individual land cover classifications in the study region and hence are not
negligible. The contribution of terrestrial surfaces fluxes was easily
detectable in both simulated and measured concentrations of atmospheric
CO2 at the only tall tower site in the study region. Although, the
tower is positioned next to Roskilde Fjord, the local marine impact was not
distinguishable in the simulated concentrations. But the regional impact from
the Danish inner waters and the Baltic Sea increased the atmospheric
concentration by up to 0.5 ppm during the winter months.