bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar Filament Eruptions as Precursors to Flare–CME Events: Establishing the Temporal Connection
Authors: Sinha Suvadip , Srivastava Nandita , Nandy Dibyendu
Published: July 2019

Elongated structures on the Sun’s surface known as filaments are known to have a connection with energetic events of space weather consequence (flares and coronal mass ejections (CMEs)). In this work, we explore the connection between the eruptive dynamics of filaments and the initiation of solar flares and CMEs. We estimate the filament eruption start time by tracking the filament throughout its eruption phase. We define the filament eruption start time as the time from which the filament area starts to decrease as observed in Hα images. A total of 33 eruptive filament events are reported in this study, out of which 73% are CME associated and 76% are related to solar flares. We find a good correlation between area decay rate of the quiescent filaments and the speed of the associated CMEs with a correlation coefficient of 0.75. By analyzing the time delay of the extreme ultraviolet brightening of solar flares relative to the start time of associated filament eruption, we show that in 83% of cases, filament eruption precedes the flare brightening, which indicates that eruptive filaments can be considered as one of the precursors for the occurrence of a solar flare. Finally, we study the time delay of the CME onset from the time of initiation of the filament eruption process and show that for most of the cases, CMEs occur within 2 hr from the start time of the filament eruptions. This study would be useful for space weather assessment and characterization based on automated trackers of solar filament dynamics.
Detection of Unobserved Ground Targets by Use of Seismic Location Stations
Authors: Hashimov E. , Bayramov A. , Sabziev E.
Published: July 2019

The detection method of moving unobserved ground military heavy trucks is considered in paper. The 3D coordinates detection set and the seismic location method are used in our study. The computational algorithm of determination of the bearing angle and distance to unobserved ground target are presented, the computational uncertainties are estimated. The triangular form of 3D detectors in one seismic location cell is offered. It allows minimizing distance and angle uncertainties in target direction. To improve the detection effectiveness, the optimal geometry disposition of 3D detectors in seismic location cells is determined. The offered method is effective in case of terrain relief where seismic-acoustic signal is propagated by approximately straight line. Therefore, this method can be applied only to homogenous medium, for example, to mountainous, solid rocky soil.
Computationally Fast Dynamical Model of a SATCOM Antenna Suitable for Extensive Optimization Tasks
Authors: Najman J. , Bastl M. , Appel M. , Grepl R.
Published: July 2019

Development of new SATCOM (Satellite Communications) antennas and their control systems is a complex problem, in which strict requirements for mechanical design, drives, sensors and the overall speed and accuracy of the control algorithm must be met. Therefore, a simulation model is often used at different stages of development, which greatly accelerates the process of designing and optimizing the whole system. The computationally most demanding part of the simulation is the dynamical model of antenna. This article proposes an alternative approach for dynamical model creation, and the results are compared to a model created by using a universal multibody simulation environment. It is shown that the proposed new approach gives nearly the same-quality results and it is several times computationally faster.
Analysis of Impact of Conic Aperture in Differentially Pumped Chamber
Authors: Maxa J. , Hlavatá P. , Vyroubal P.
Published: July 2019

The paper focuses on the simulation of medium dynamics in the environmental scanning electron microscope. In particular, the paper examines the conical aperture location effect in the differentially pumped chamber and the width of the pumping channel in this chamber. The solution is based on the Taylor-Maccoll theory about the impact of the shock wave and was obtained by the use of continuum and finite volume methods in the ANSYS Fluent system.
Methodologies for Reliability Prediction of Electronic Component in Military Vehicles
Authors: Cu P. , Bui A.
Published: July 2019

Reliability prediction is conducted in all phases of the product life cycle. The purpose of these predictions is to identify the potential weaknesses in design, to evaluate the design feasibility, to compare alternative designs, to provide the model for reliability analysis, to track reliability improvement, etc. Reliability of electronic component is predicted by using statistical prediction methods (standards-based), statistical analysis of operation & maintenance data or by performing reliability testing. The article describes statistical prediction methods such as MIL-HDBK-217, RIAC 217Plus, FIDES Guide 2009, which are widely used for predicting the reliability of electronic components. In addition, we have calculated and compared the failure rate of electronic components in military vehicles conducted with the use of these different methods.
Numerical Simulation of Flow Field in Coaxial Tank Gun Recoil Damper
Authors: Elsaady W. , Ibrahim A. , Abdalla A.
Published: July 2019

To know the hydraulic resistance of tank gun hydraulic damper is essential to determine the barrel recoil parameters. Usage of one-dimensional analytical models simplifies the determination of the hydraulic resistance; however these models do not provide data about the flow nature inside the hydraulic damper. This paper studies the internal flow inside the hydraulic damper of the gun recoil system. The dynamic mesh technique using two-dimensional flow computational solver has been used. A User Defined Function (UDF) has been developed to feed the solver by the measured recoil velocity. The study shows that the liquid flow inside the hydraulic damper is complicated at the start of the gun recoil and it is quickly changing to a simpler flow pattern until the end of the recoil. Also, the liquid pressure inside the hydraulic damper has been measured and compared to the computational values.
Body burden of pesticides and shape asymmetry in carabid beetles in different agricultural practices in Mediterranean agroecosystems
Authors: Šerić Jelaska Lucija , Anđelić Barbara , Jelić Mišel , Kos Tomislav , Benitez Hugo
Published: July 2019

Neonicotinoids have been the most commonly used insecticides worldwide in the last two decades, whereas application of Copper (Cu) has a much longer history, especially in Mediterranean agriculture, (e.g. vineyards). Lately, large numbers of studies have shown negative effects of neonicotinoids on non-target species (especially on bees but also on other insects, and indirectly on insectivorous species like birds) being thus recently banned by EU commission. On the other hand, intensification of production in favour of ecological pest management increases the use of copper in pest control schemes and its absorption in agroecosystems. In this study we aimed to quantify the relationships between pesticide concentrations, including those with copper compounds, in soil, carabids and its prey at four sampling sites, in vineyards and olive groves under integrated (IPM) and ecological pest managements (EPM), and in pristine habitats in Zadar County, in Mediterranean region of Croatia. Soil, carabids, earthworms, snails and woodlice were sampled using pitfall traps and by hand. LC-MS/MS and ICP-MS technique were utilised to quantify pesticides and Cu concentrations in the soil and in the animals representing different trophic guilds. In addition we analysed changes in body shape symmetry of Poecilus koyi, one of the most dominant predatory carabid species in the study sites, in order to evaluate the potential environmental stress between maned and pristine habitats that can affect carabids during their development. Geometric morphometrics (GMM) has been used to analyse pronotum and abdomen shape variations, and left/right asymmetries in up to100 individuals of P. koyi per study site. Some preliminary results showed that body burden with pesticides differ between prey and predator organisms, and body concentrations of certain pesticides in carabid beetles did not correlate with those in the soil. Distribution of pesticide along different trophic guilds and changes in body shape and fluctuating asymmetry in P. koyi populations will be presented and discussed in details.
Language evolution to revolution: the leap from rich-vocabulary non-recursive communication system to recursive language 70,000 years ago was associated with acquisition of a novel component of imagination, called Prefrontal Synthesis, enabled by a mutation that slowed down the prefrontal cortex maturation simultaneously in two or more children – the Romulus and Remus hypothesis
Authors: Vyshedskiy Andrey
Published: July 2019

There is an overwhelming archeological and genetic evidence that modern speech apparatus was acquired by hominins by 600,000 years ago. On the other hand, artifacts signifying modern imagination, such as (1) composite figurative arts, (2) bone needles with an eye, (3) construction of dwellings, and (4) elaborate burials arose not earlier than 70,000 years ago. It remains unclear (1) why there was a long gap between acquisition of modern speech apparatus and modern imagination, (2) what triggered the acquisition of modern imagination 70,000 years ago, and (3) what role language might have played in this process. Our research into evolutionary origin of modern imagination has been driven by the observation of a temporal limit for the development of a particular component of imagination. Modern children not exposed to recursive language in early childhood never acquire the type of active constructive imagination called Prefrontal Synthesis (PFS). Unlike vocabulary and grammar acquisition, which can be learned throughout one’s lifetime, there is a strong critical period for the development of PFS and individuals not exposed to recursive language in early childhood can never acquire PFS as adults. Their language will always lack understanding of spatial prepositions and recursion that depend on the PFS ability. In a similar manner, early hominins would not have been able to learn recursive language as adults and, therefore, would not be able to teach recursive language to their children. Thus, the existence of a strong critical period for PFS acquisition creates an evolutionary barrier for behavioral modernity. An evolutionary mathematical model suggests that a synergistic confluence of three events (1) a genetic mutation that extended the critical period by slowing down the prefrontal cortex development simultaneously in two or more children, (2) invention of recursive elements of language, such as spatial prepositions, by these children and (3) their dialogic communications using these recursive elements, resulted in concurrent conversion of a non-recursive communication system of their parents to recursive language and acquisition of PFS around 70,000 years ago.
Will New Graduate Nurse Residencies Be a Mandate of the Future?
Authors: Shinners Jean
Published: July 2019

Nursing professional development (NPD) and continuing education (CE) administrators are constantly prioritizing where they put their energy and resources. With the American Academy of Nursing (AAN) policy brief recommending mandatory nurse residency programs and Maryland taking the lead as an early adopter through collaboration (not mandate), it is important that NPD and CE practitioners and administrators are aware of the current landscape in the area of new graduate RN transition to practice.

[
J Contin Educ Nurs.
2019;50(8):341–344]

.
Burnout 3.0
Authors: Jones-Schenk Jan
Published: July 2019

Although burnout has long been discussed and recognized in nurses, the fact that it is now classified in the World Health Organization's International Classification of Diseases brings it back into the forefront. Dismissal of burnout as a generational construct or a lack of resilience carries significant risks for individuals, organizations, and the clients they serve. Purpose-driven work actually may exacerbate the rise of burnout.

[
J Contin Educ Nurs.
2019;50(8):345–346.]
The FIRST Curriculum: Cultivating Speaking Up Behaviors in the Clinical Learning Environment
Authors: Best Jennifer A. , Kim Sara
Published: July 2019

Expressing concerns that arise during patient care is essential to protecting patient safety. A speaking up episode occurs within a power hierarchy and carries high potential for personal and professional consequences. Existing curricula that promote speaking up, such as TeamSTEPPS
™
, extensively focus on verbal skills without recognizing the important emotional dimensions of speaking up. We developed the FIRST Speaking Up curriculum that covered the following: (a) inner barriers related to expectations of one's own identity, (b) cognitive distortions associated with speaking up, (c) the speaking up environment, (d) dialogue skills for the speaker and the listener, and (e) resilience strategies. The curriculum was delivered via 2 to 3 hours of interactive workshops to 109 participants, including 40 nursing staff and leaders, 24 plastic surgery residents, and 45 internal medicine residents. Evidence showed that training improved participants' motivations to speak up concerns. Our work expands on existing strategies for speaking up training by targeting both verbal and emotional skills.

[
J Contin Educ Nurs.
2019;50(8):355–361.]
Exploring Patterns in Preferences for Daily Care and Activities Among Nursing Home Residents
Authors: Roberts Tonya J. , Saliba Debra
Published: July 2019

Nursing homes have shifted from task-focused to person-centered care (PCC) environments. Understanding resident preferences for daily care and activities is fundamental to PCC. Examining resident similarities based on preferences may be useful for group or community-wide PCC planning. The aims of the current study were to group residents according to similarities in preferences and determine the factors that predict membership in these groups. A latent class analysis of resident preferences using data from the Minimum Data Set (
N
= 244,718) was conducted. Resident function, depression, cognitive impairment, and sociodemographics were used as predictors of class membership. The four-class model showed residents cluster around overall interest or disinterest in having choices about daily care and activities or specific interest in either care or activity preferences. Race and ethnicity, cognitive impairment, and depression predicted class membership. Findings suggest that residents can be grouped by preferences and knowledge of resident group membership could help direct efforts to systematically meet resident preferences. [
Journal of Gerontological Nursing, 45
(8), 7–13.]
The Safety of Continuing Antiplatelet Medication Among Elderly Patients Undergoing Urgent Hip Fracture Surgery
Authors: Lin Sung-Yen , Huang Hsuan-Ti , Chou Shih-Hsiang , Ho Cheng-Jung , Liu Zi-Miao , Chen Chung-Hwan , Lu Cheng-Chang
Published: July 2019

Elderly patients with hip fractures who are receiving antiplatelet therapy are commonly encountered in clinical practice. This study sought to elucidate the safety of urgent hip surgery without termination of antiplatelet medication among patients taking a combination of aspirin and dipyridamole, aspirin alone, or dipyridamole alone. This retrospective cohort study included 176 patients 55 years or older who had uncomplicated hip fractures and underwent surgery within 48 hours after admission. On the basis of the preoperative medication regimen, the patients were divided into the following 4 groups: those receiving aspirin and dipyridamole combined (n=29); those receiving aspirin alone (n=63); those receiving dipyridamole alone (n=28); and those not receiving antiplatelet medication (n=56). Main outcomes, including total blood loss, transfusion rate, and 1-year mortality, were analyzed. There was no significant difference in total blood loss, transfusion rate, or 1-year mortality among the 4 groups. The group receiving aspirin and dipyridamole combined preoperatively had increased intraoperative blood loss (mean, 309.14±189.15 mL) compared with the group not receiving antiplatelet medication (mean, 214.64±119.21 mL;
P
=.005). There was no significant difference in the hazard ratio (
P
>.05) for 1-year mortality among the 4 groups after adjusting for confounding covariates, including age, sex, Charlson Comorbidity Index, and duration of hospital stay. Patients receiving antiplatelet medication, including aspirin, dipyridamole, or both, who have uncomplicated hip fractures may undergo urgent surgery without a significant difference in total blood loss, transfusion rate, or 1-year mortality compared with patients not receiving anti-platelet medication. [
Orthopedics
. 2019; 42(5):268–274.]
Hemiepiphysiodesis for Idiopathic Genu Valgum Using Physeal Staples Versus Tension-Band Plating: A Systematic Review
Authors: Knapik Derrick M. , Buschbach James , Sabharwal Sanjeev , Liu Raymond W.
Published: July 2019

This review assesses the outcomes of hemiepiphysiodesis in patients with idiopathic genu valgum (IGV) treated with physeal staples vs tension-band plating (TBP). A systematic review of the literature was conducted to identify articles examining the use of physeal staples vs TBP for the treatment of IGV in skeletally immature patients. No significant difference in overall mean deformity correction (
P
=.92) or correction per month (
P
=.61) was observed between groups. Repeat hemiepiphysiodesis was more common in patients who underwent TBP vs physeal staples (
P
=.05). Tension-band plating did not yield significantly improved results compared with physeal staples in skeletally immature patients with IGV. [
Orthopedics
. 2019; 42(6):e485–e491.]
Diagnosis and Management Strategies for Distal Biceps Rupture
Authors: Holt Jarred , Preston Gordon , Heindel Koan , Preston Heather , Hill Gregory
Published: July 2019

Rupture of the distal biceps tendon most commonly is secondary to mechanical overload during eccentric muscle contraction. Due to deficits of strength and endurance, surgical repair usually is recommended. Although both single- and double-incision approaches have been described, double-incision techniques have been shown to better re-create the native anatomic insertion. However, excellent and comparable clinical outcomes have been demonstrated with both techniques. Fixation with a cortical button and interference screw has been shown to be the strongest construct biomechanically; however, several modern constructs provide adequate strength. Surgical technique should focus on restoration of anatomy, early range of motion, and prevention of complications. [
Orthopedics
. 2019; 42(6):e492–e501.]
Postdischarge Opiate-Prescribing Habits for Primary THA and TKA: A Survey of American Association of Hip and Knee Surgeons Members
Authors: Lipof Jason S. , Thirukumaran Caroline P. , Greenstein Alexander S. , Zmich Zachary , Lander Alexander , Ricciardi Benjamin F.
Published: July 2019

Abuse of opiate medications has reached epidemic proportions, and elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) typically require outpatient use of narcotic medications. This survey sought to determine opiate-prescribing habits of members of the American Association of Hip and Knee Surgeons (AAHKS) for patients undergoing primary THA and TKA. An 11-question online survey was developed to evaluate current prescribing habits for opiate and nonopiate medications prescribed after primary THA and TKA. An invitation to complete the survey was e-mailed to 2698 orthopedic surgeons using an AAHKS listserv. Surgeons' demographic information and their prescribing habits of opiate and nonopiate medications postdischarge were recorded. Data were examined using descriptive statistics, chi-square, and multivariate logistic regression. Responses were received from 325 of 2698 (12.1%) AAHKS members. Significant variation in the type of opiate prescribed and the number of pills dispensed was observed. Higher surgical volume and less years in surgical practice were associated with a higher number of opiate pills prescribed after THA and TKA. There were no statistically significant associations between opiates prescribed and use of an ambulatory surgery center or presence of departmental guidelines. Although THA and TKA are relatively standardized procedures performed nationwide, significant variability exists among surgeons regarding postdischarge opiate- and nonopiate-prescribing habits. There is a need for greater standardization to create a unified, evidence-based, and safe regimen for the postoperative period while reducing the opiate burden in the surrounding community. [
Orthopedics
. 2019; 42(6):361–367.]
A New Technique for Radiographic Visualization of the Scaphotrapeziotrapezoid Joint
Authors: Brown Ashley M. , Winfield Sarah M. , Kuschner Stuart H.
Published: July 2019

Standard radiographs of the wrist do not provide adequate visualization of the scaphotrapeziotrapezoid joint. A radiographic technique that provides an improved and more complete visualization of the joint compared with routine views is described. [
Orthopedics
. 2020; 43(2):e123–e124.]
The Role of Epikarst in the Morphogenesis of the Karstic Forms, Especially Hollow Forms in Greece
Authors: Papadopoulou-Vrynioti Kyriaki
Published: July 2019

Vloga epikrasa pri nastanku podtalnih škrapelj in kraških depresij, je različna. Prevotljene škraplje in podtalne škraplje tipa »kluftkarren« so prekrite s kraško prstjo in kažejo na delovanje vode. Nastale so v epikraški coni ob razpokah s pomočjo difuzne korozije v kapilarnem vodonosniku v zgornjem delu vadozne cone. Zaobljeni vrhnji deli in luknje v škrapljah so nastale zaradi enakomerne in stalne korozije s pomočjo talne vlage v zgornjem delu epikraške cone. Kraške depresije pa so razvite v karbonantih plasteh in tudi na stiku zakraselih in nezakraselih, a eroziji podvrženih kamnin. V tem primeru nastane veliko drobirja, iz katerega nastane prst, ki zapolni te reliefne oblike. Uvale in polja so navadno razvita na mestu nekdanjih suhih dolin ali tektonskih udorin s pomočjo razširjanja razpok v subkutani coni in zaradi njenega spuščanja. Sočasno ta cona postaja postopoma neprepustna in s tem se krepi robna korozija. Te oblike navadno nastajajo nad piezometrično gladino. Kraška polja – presihajoča jezera pa so nastala, kjer so depresije občasno dosegle gladino talne vode v epikrasu. The role of epikarst in the morphogenesis of the subcutaneous karren and the karstic hollow forms is different. Cavernous karren and subcutaneous kluftkarren, are covered with terra rossa and show the activity of water. They are developed in the epikarstic zone due to the diffused corrosion on the joints through a capillary aquifer, situated in the high vadose zone. The rounded tops and the cavities of those subcutaneous karren are formed due to the continuous and uniform corrosion, acting by soil moisture in the high part of the epikarstic zone. Karstic hollowforms are developed in carbonate layers only, and also on the contact of karstifi ed and non-karstifi ed but easily erodable rocks. In this case, a lot of material is produced for the formation of soils that fi ll these landforms. Uvalas and poljes usually develop in sites of old valleys or tectonic depressions through the process of widening of the joints in the subcutaneous zone and the lowering of the latter zone. Simultaneously there occurs the gradual impermeability of the zone and the reinforcement of the lateral corrosion. These forms are mostly formed above the piezometric level. The poljes - periodical lakes are created due to the development when they temporary reach epikarstic water table.
Preparation and Characterization of 3-Glycidoxypropyltrimethoxysilane Functionalized Graphene Oxide
Authors: Wang Kun Yan
Published: July 2019

The graphene oxide (GO) was prepared by the Hummers method, and then functionalized by 3-glycidoxypropyltrimethoxysilane. Functionalized graphene oxide (FGO) was characterized by using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG). The results show that 3-glycidoxypropyltrimethoxysilane reacted with hydroxyl group of graphene oxide. The FGO have a sheet-like structure with wrinkles. The shifts of XRD peaks to low degree for FGO indicate the occurrence of intercalation of 3-glycidoxypropyltrimethoxysilane and as well as increase in the thermal stability.
Cr12MoV Die Repair Experiment Based on Laser Cladding with Wire
Authors: Yin Yan , Wang Yun , Tan Zhong Rui , Yu Wei Jie
Published: July 2019

In this paper, SKD11 steel wire has been deposited on Cr12MoV plate using Nd: YAG pulsed laser for repairing the die surface damage. The effects of laser power, wire feeding speed, scanning speed and surface roughness on clad geometry have been studied with OM and LSCM. hardness distribution of the cladding layer is also obtained by microhardness tester. Experiment results indicate that the surface roughness is important for clad characteristics due to the light trapping effect. With the increases of roughness, the laser absorption ratio can be raised, both the clad depth and the dilution rate increase, the height decreases. The essence of influence mechanism is effective body energy Ev and specific filling rate ω, and can be used as critical process factors. When Ev is 80~100 J/mm3 and ω is 1~3, a flat cladding layer can be obtained with low dilution, less fusion defects and high hardness. Keywords: Cr12MoV, laser cladding with wire, surface roughness, clad geometry, hardness
Effect of Different Hole-Making Technology on Fatigue Properties of Directionally Solidified Alloy IC10
Authors: Lian Ye Da , Xu Z. , Gao Q. , Liu Lu , Wen Z.
Published: July 2019

The fatigue tests were carried out under two kinds of hole-making technology, forming EDM and high-speed EDM. The hole taper and fracture surface of the sample were compared and analyzed. The finite element model with hole taper was established and the influence of the hole making technology on fatigue life was analyzed. Three conclusions have been obtained:First, the inner surface of the hole of the formed EDM is relatively flat, the residual deposit formed during the processing is less. and thickness of the recast layer and the content of oxygen are also lower than the high-speed EDM. Second,The fracture surface of the formed EDM shows obvious crack source, while the high-speed EDM has no crack source, and the area of the crack propagation area of the high-speed EDM is obviously larger. Third,the high-speed electric spark machining has obvious taper, under the load condition, the stress at the large hole end is higher than that at the small hole end, and large strain and damage are generated at the same time, resulting in crack initiation at the end of the large hole.
Failure Observation of 3D-Printed Thrust Bearing Specimens with Inner Defects in Water Conditions
Authors: Mizobe Koshiro , Atsumi Tatsuki , Kida Katsuyuki
Published: July 2019

Additive manufacturing (AM) methods are developing and have become popular, but questions remain about the strength of parts made by this method. We have already investigated the effect of the lamination direction on the fractures in bearing specimens. In this study, we made inner defects in the 3D-printed bearing specimens and performed rolling contact fatigue (RCF) tests on this specimens immersed in a water bath in order to investigate the fracture of 3D printed bearings.
New Low Alloy High Strength Steel Welding Procedure Evaluation
Authors: Li Wen Juan
Published: July 2019

In order to determine the weldability of a new type of low alloy high strength steel, the feasibility of the proposed welding process was examined and the welding procedure qualification of a new type of ultrahigh strength steel WELDOX 1100 was carried out through the weldability test of the welded joint, the small iron research and the highest hardness test. . The test result satisfies the specification requirements and proves that the proposed welding process plan is correct and feasible. It provides a reliable basis for the preparation of welding process documents and ensures the smooth development of the company's new products.
Study on Welding Technology of Low Alloy High Strength Steel
Authors: Hu Min
Published: July 2019

WELDOX series steels are commonly used structural steels. The effects of welding voltage, welding current and arc height on penetration and weld width of WELDOX960 steel sheet were studied. The mechanical properties and microstructure of WELDOX960E high strength steel welded joints were study by tensile, bending, impact, hardness and metallographic analysis.
Influence of Molding Pressure on Properties of Al2O3- Al Composite Materials Sintered via Vacuum Sintering Method
Authors: Wang Rui Hua , Chen Ai Xia , Yang Chao , Wang Fang , Du Da Ming , Li Shi Bin , Song Jie Guang , Chen Lin
Published: July 2019

In this paper, the effect of raw materaisl on the properties of coated Al2O3/Al cermet materials were investigated, the raw materials were prepared via different methods, which provide a reference for obtaining higher performance cermet materials. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn, the density of the composite material increases first and then decreases with the increase of the molding pressure. When the molding pressure is 30 MPa, the density of the composite material reaches the maximum value, that is 93.5%. The greater the applied pressure, the more compact the aluminum powder and alumina powder, and the longer the tissue composition, the more uniform. there is no crack in the c-picture, and there are cracks in the a and b pictures. The microstructure of metal matrix composites prepared at different molding pressures is also different. Sintering of the green body formed at 30 MPa resulted in relatively few cracks and voids in the material. The surface hardness of the composite material increases first and then decreases with the increase of the molding pressure, and the surface hardness of the composite material reaches a maximum value (875 HV) at a molding pressure of 30 MPa.
Evaluation of Wickability of Quick Dry Inner Wear
Authors: Wang Wen Yi , Heng Hin , Yim Hin Heng Lois , Kan Chi Wai , Sasithorn Nongnut , Wangkanai Puvisit , Vuthiganond Nattaya , Mongkholrattanasit Rattanaphol
Published: July 2019

Quick dry inner wear products become increasingly popular in the tropical regions with a hot and rainy climate. This study evaluated the quick dry property of three inner wear for women available in the market via studying their wicking rates. It was found that one products had satisfactory wicking ability as they claimed, whereas one products showed no quick dry property.
Observation of Crack Growth Behavior of 400μm Cracks in 4.762mm Silicon Nitride Balls under Cyclic Compressive Load
Authors: Toriki Takumi , Matsui Tomoya , Kida Katsuyuki
Published: July 2019

In order to investigate the effect of pre-crack lengths on silicon nitride balls under cyclic pressure loads, the pre-crack lengths ranging from 400μm to 500μm were observed. Their growth behavior was compared to that of 200μm to 300μm pre-cracks. Furthermore, the initial threshold limits of their maximum stress intensity factors were measured.
Comparison of Three Commercial Latex and Non-Latex Orthodontic Elastic Bands
Authors: Malanon Sasatorn , Dechkunakorn Surachai , Anuwongnukroh Niwat , Wichai Wassana
Published: July 2019

Orthodontic elastic bands are commonly made from natural rubber because they provide high resiliency at a reasonable cost. However, hypersensitivity related to protein present in latex have been reported in some patients which has led to increased usage of non-latex elastic alternatives. Therefore, the assessment of their mechanical properties is of importance. The objective of this study was to compare the physical and mechanical properties of three commercial latex and non-latex type orthodontic elastic bands. Samples of latex and non-latex type orthodontic elastics from manufacturers – AO (6.5oz), MASEL (6.0oz), GAC (6.0oz), with 3/16-inch diameter were selected. Firstly, the physical characteristics (width, cross-sectional thickness, and inner diameter) of the elastic bands were determined, following which their mechanical properties [initial extension force (F0), 24 h-residual force (F24), percentage of force decay, force exerted at 3 times the inner diameter (F3xID) and breaking force] were tested. The data were analyzed with Mann-Whitney U test and multiple comparisons among the groups were done with Kruskal-Wallis Test (p< 0.05). Significant differences were found in the physical characteristics and mechanical properties among each brand and type of elastics. AO elastic bands had significantly low F0 and F24 compared with the others. While the percentage of force decay at 24 h was greatest in AO followed by MASEL and GAC. Non-latex type elastics showed greater force decay than latex type ones, approximately 30-40% and 20-30% of the initial force in non-latex and latex type elastic, respectively. AO elastics showed the highest F3xID and also the lowest breaking force. Overall, non-latex type elastics exhibited lower breaking force compared to latex type ones. Wide variations were observed in the physical and mechanical characteristics among same manufacturer and same elastic type. All commercial brands presented higher F3xID than that stated by the manufacturers. Non-latex type elastics showed greater force decay over 24 h than latex type ones. The differences in the properties between the 2 types of the elastics could be due to the differences in their structure and polymers composition.
Chemical Constituents of the Aerial Parts of Scoparia Dulcis and Anti-Cancer, Anti-Inflammatory Activities
Authors: Tin Nguyen Ngoc Thanh , Truc Nguyen Dang Thanh , Hang Hoang Thi Thu , Trinh Pham Thi Nhat , Bach Long Giang , Dung Le Tien
Published: July 2019

In Vietnam, the medicinal plant Scoparia dulcis is used for the treatment of bronchitis, gastric disorders, antidiabetes, hypertension, hepatitis etc.1 In this paper, experiments was designed to evaluate in vitro anticancer and anti-inflammatory activities and isolate phytochemicals from methanol extracts of Scoparia dulcis whole plants. The chemical investigation of methanol fraction of Scoparia dulcis led to the isolation of benzoxazinone (1), phenylethanoid (2), flavone (3), and lignan (4) glycosides. The bioactivity results indicated that crude ethanol and ethyl acetate extracts had potent cytotoxic activity toward the HepG2 cancer cell with IC50 of 47.03 μg/mL and 36.04 μg/mL, respectively. Interestingly, crude ethanol and ethyl acetate extracts had the NO inhibitory activity, with inhibition of 56.9 % or 74.7 % at 30 μg/mL and 97.3% or 82.9 % at 100 μg/mL, respectively. In addition, the hexane extract at concentrations of 100 μg/ml demonstrated anti-inflammatory activity through the inhibition of nitric oxide production of 76.7%.
Preparation, Characterization and Hemostatic Properties of Chitosan Caffeates
Authors: Lu Si Tong , Zhang Dong Ying , Hu Zhang , Li Si Dong , Li Pu Wang
Published: July 2019

In this paper, chitosan and caffeic acid were used as starting materials to prepare chitosan caffeates by reflux-heating and freeze-drying. The structures of chitosan caffeates were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and potentiometric titration. At the same time, the physical properties of chitosan caffeates were tested and the hemostatic properties were evaluated. The results showed that four chitosan caffeates with different mass ratios of chitosan and caffeic acid (1:1, 1:2, 1:4, 1:6) had been successfully prepared, which enhanced the water solubility. FTIR analysis demonstrated that caffeic acid had been successfully grafted onto chitosan chains. XRD showed that the crystal form of chitosan changed to some extent and the chain had some regularity in some directions, but its crystallinity reduced. Chitosan caffeates, particularly mass ratio of 1:1, showed excellent hemostatic properties and even better than chitosan and the positive control (Yunnan Baiyao), which were expected to be developed as an effective biomaterial for hemostasis.
Shear Bond Strength of Experimental Light-Cured Orthodontic Adhesives
Authors: Nimcharoensuk Kanin , Anuwongnukroh Niwat , Dechkunakorn Surachai , Sattabanasuk Vanthana , Wichai Wassana , Sunintaboon Panya
Published: July 2019

The objective of this study was to compare shear bond strength (SBS) and adhesive remnant index (ARI) of domestically made orthodontic adhesives to a commercial orthodontic adhesive, Transbond XT (3M Unitek, USA). Three formulas of an in-house orthodontic adhesive were divided according to monomer ratio (BisGMA:TEGDMA) into group 1 (8:2), 2 (7:3), and 3 (6:4), respectively, with 60-70 weight % of filler amount and 0.5 % of photoinitiator (TPO). Eighty upper human premolars (20 of each group) were bonded with stainless-steel brackets with these experimental and control adhesives. All were cured by LED light-cured unit for 20 seconds. After polymerization for 24 hours, a universal testing machine was used to apply an occlusal shear force to the enamel/bracket interface at a speed of 0.5 mm/min. The ARI scores were evaluated for each debonded tooth. Mean SBS values were analyzed statistically using the One-way ANOVA and the Tukey’s test for multiple comparison. Chi-square test was used to determine significant difference in the ARI scores. The results showed that there was statistical difference in the mean SBS of 4 groups (P<.001). The SBS value of group 1, 2, 3, and control was 18.79 MPa, 18.58 MPa, 23.30 MPa, and 28.02 MPa, respectively. Chi-square comparison for the ARI indicated that there was significant difference (P=.012) between the groups. In conclusion, the experimental adhesive of group 3 yields the higher SBS than in group 1 and group 2. Although these adhesives provide a lower shear bond strength than Transbond XT, they were acceptable for clinical use. Most failures of Transbond XT were found between adhesive-bracket interface, whereas the three in-house experimental adhesives were found mixed failure patterns of ARI.
Water Resistance Modification of Magnesium Oxychloride Cement with H3PO4/Na2O·xSiO2·nH2O
Authors: Fan Tian Ben , Hao Ya Fei , Li Ling Xiao , Zhao Feng Qing
Published: July 2019

Magnesium oxychloride cement (MOC) possesses rapid hardening, high mechanical strength, abrasion resistance, low alkali and low corrosive performances. However, its disadvantages of poor water resistance, easily deformation, moisture absorption and halogenations limit the application. A low cost-effective modifier H3PO4/Na2O·xSiO2·nH2O was designed for MOC system. The results showed that the softening coefficient of the modified MOC reaches 0.988 by adding appropriate dosage of the modifier. Gelatinous substances in the modified MOC was produced after soaking in water, which effectively inhibit the hydrolysis of phase 5 (5Mg (OH)2·MgCl2·8H2O) and the formation of Mg (OH)2, thus improving the water resistance of MOC system. Keywords: Magnesium oxychloride cement; Water resistance; Phosphoric acid
Ni0.75Fe0.25 Coated Tubular GDC Anode for Cathode-Supported IT-SOFC with High Anode Porosity
Authors: You Hong Xin , Peng Lian , Wang Qiang
Published: July 2019

Ni0.75Fe0.25Ox-GDC cermet anode for intermediate temperature solid oxide fuel cell was prepared by hard template method and wet impregnation method. LSC-GDC cathode-supported single cell was fabricated by using Ni0.75Fe0.25 coated tubular GDC as anode for the performance test. The composite anode material with Ni-Fe alloy particles coated tubular GDC was analyzed by XRD and SEM. The maximum power density of the single cell in hydrogen and dry methane was 736 and 400 mW·cm-2 at 800 °C, respectively. The SEM observation showed that the anode had a porous three-dimensional microstructure with high specific surface and rich gas channel, resulting a high power generation performance.
Congo Red Dye Removal Using Ca-Al Layered Double Hydroxide: Kinetics and Equilibrium
Authors: Thi Hong Tham Nguyen , Nguyen Duy Chinh , Nguyen Thi Thuong , Tran Van Thuan , Nguyen Huu Vinh , Bach Long Giang , N-Vo Dai Viet , Nguyen Dai Hai , Thuan Doan Van , Do Sy Trung , Nguyen Trinh Duy
Published: July 2019

This In this study, the Ca-Al layered double hydroxide was used as a potential adsorbent for the removal of Congo red from aqueous solutions. The effects of Initial concentration and contact time on the adsorption properties of Congo red by Ca-Al LDHs were studied. The removal rate of Conge red reached to 59.416 mg/g under room temperature with 0.2g of adsorbent, initial concentration of 50 ppm, adsorption time of 210 min, shaking speed of 90r/min. The experimental equilibrium data for the removal of Congo red were evaluated by various isotherm models. The pseudo-second-order kinetic models were found to fit the adsorption kinetics, and the equilibrium data were appropriately fitted to Langmuir and Freundlich model adsorption isotherm.
Effects of Extraction Conditions on Total Phenolic Content and Total Flavonoid Content of Roselle (Hibiscus sabdariffa L.) Extracts
Authors: Duy Nguyen Quoc , Binh Mai Le Thanh , Thuan Ma , Van Ngo Thi Thanh , Lam Tri Duc , Tran Thien Hien , Nhan Phu Nguyen Thuong
Published: July 2019

The objective of this study was to determine the optimal value of factors affecting the extraction of compounds such as, polyphenols, flavonoids of Roselle. The investigated factors included extraction temperatures (30, 40, 50, 60, 70 and 80°C), extraction time (30, 60, 90, 120 and 150 minutes) and solid to solvent ratio (1:5, 1:10, 1:20, 1:40 and 1:50 g/mL). The efficiency of extraction was evaluated based on total phenolic content (TPC) and total flavonoid content (TFC). The results showed that temperature range of 60–80°C was the appropriate temperature for TFC while extraction temperature over 60°C was suitable for achieving highest TPC. Considering the effect of extraction time, duration of 90–150 minutes facilitated the extraction of both phenolics and flavonoids. Moreover, the solid to solvent 1:20 was chosen for extraction process based on the balance of antioxidant contents and their yield.
Synthesis of New Phosphate and the Evaluation as Scale Inhibitor in Oilfield
Authors: Xu Ren Jun , He Hua Lei , Wang Jing , Hui Hai Peng , Liu Qiao Na
Published: July 2019

Compared with inorganic phosphonates, organic phosphonates have better chemical stability in water treatment, and are not easy to hydrolyze in higher temperature and wider pH range. In this paper, a one-step synthesis method of ethylene diamine tetra (methylene phosphonic acid) sodium (EDTMPS) and methylene phosphonic acid (DTPMPA) were studied. A new phosphate scale inhibitor was prepared and its scale inhibition performance was evaluated. The results showed that the scale inhibition rate increased with the increase of the concentration of synthetic products (EDTMPS, DTPMPA). At the same concentration, compared with DTPMPA, EDTMPS has better scale inhibition performance, and the maximum scale inhibition rate can reach 96.85%. The scale inhibition performance of composite scale inhibitor is better than that of single scale inhibitor, and the scale inhibition rate of the synthesized products can reach more than 90% after compounding. And inhibitory mechanism has been proposed: Because phosphonates effectively control the rate of nucleation. In addition, polyphosphonates can chelate Ca2+, Mg2+ plasma to form monocyclic or bicyclic chelates. This will destroy the normal growth process of calcium carbonate and other crystals, thus preventing the formation of calcium carbonate scale.
Preparation and Evaluation of Phosphate Scale Inhibitor for Oilfield Produced Water
Authors: Wang Wei , Yi Yong Gen , Sun Zhi Fei , Dong San Bao , Du Wei Chao
Published: July 2019

Phosphorus scale inhibitor is a kind of agent which can disperse insoluble inorganic salts in water, prevent or interfere with the precipitation and scaling of insoluble inorganic salts on metal surface, and maintain better heat transfer effect of metal equipment. Sodium triethylenetetramine hexamethylphosphonate (TETHMPS) and tetraethylenepentamine heptagon methylene phosphonic (TEPHMPS) were prepared by one-step synthesis method. The effects of temperature, concentration and mixing ratio on scale inhibition were investigated. The results showed that as the concentration of TETHMPS and TEPHMPS increases, the scale inhibition rate increases. At the same temperature, compared with TETHMPS, TEPHMPS has better scale inhibition performance, and the maximum scale inhibition rate can reach 93.59%. The scale inhibition rate of the synthesized scale inhibitor at 80 °C is better than that at 60 °C. The scale inhibition performance of the compound scale inhibitor is better than that of the single scale inhibitor, showing an ideal synergistic effect. When the concentration is 60 mg/L, the scale inhibition rate of TETHMPS is 94.26%, TEPHMPS is 94.55%, and the scale inhibition rate is above 91%.
Effect of Compatibilization on the Melt Properties of Mixed Waste Plastics
Authors: Martikka Ossi , Nepal Suman , Hyvärinen Marko , Kärki Timo
Published: July 2019

The amount of waste produced increases globally, and valuable resources are lost if materials contained in wastes are not recycled. One such important material group is plastics, but it is typically mixed in municipal solid waste. In this paper, the effect of maleic compatibilizer on the melt properties of mixed waste plastic is studied in order to evaluate the effect of compatibilization on the processability of reclaimed plastics. The results indicate, that compatibilization has significant effect on both melt flow rate and melt volume index. Both are decreased notably, suggesting that compatibilization may impair the processability of mixed waste plastic, even though it is expected to improve other properties.
Electrochemical Degradation of p-Nitrophenol on Cu Nanowires and Nanocubes
Authors: Zhang Wen Ming , Ji Mu Wei , Wang Jin
Published: July 2019

{100}-faceted copper nanostructures with different morphology of nanowires and nanocubes have been prepared by one-pot method. The electroactivity of Cu nanowires and nanocubes was evaluated by degradation of p-nitrophenol. As-prepared copper nanowires exhibit higher catalytic activity for p-nitrophenol degradation than copper nanocubes, and outperform most of Cu catalysts reported in literature. Electrochemical reductive reaction of p-nitrophenol is shown to be kinetically first-order.
Photoelectric Response Difference between KTaO3/ Au and K2Ta2O6/Au Nanocrystals Resulting from Potassium Tantalate Structure
Authors: Chang Sheng Ding , Ji Mu Wei , Yan Chang Xu , Li Bo , Wang Jin
Published: July 2019

Potassium tantalates is one kind of important semiconductor with potential applications on photoelectric transformation and photocatalysis. Herein, Au nanoparticles were grown on the surface of two kinds of potassium tantalates, KTaO3 nanocubes and K2Ta2O6 nanooctahedron, by flexible reducing HAuCl4, and KTaO3/Au and K2Ta2O6/Au hetero-nanostructures were formed. Although the Au nanoparticles loading enhances the light absorption, KTaO3/Au and K2Ta2O6/Au hetero-nanostructures exhibit different photoelectric properties. The difference of photoelectric properties of two kinds of potassium tantalates/Au hetero-structures hint the photoelectric-property enhancement depends on multiple factors.