bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dependence of Solar, Plasma, and Geomagnetic Parameters’ Oscillations on the Heliospheric Magnetic Field Polarities: Wavelet Analysis
Authors: El-Borie M. A. , El-Taher A. M. , Thabet A. A. , Bishara A. A.
Published: July 2019

We investigate the dependence of solar, plasma, and geomagnetic parameters’ periodicities on the heliospheric magnetic field polarities for the past five solar activity cycles (1967–2016). For this purpose, the Morlet wavelet technique has been performed to extract information about significant periods. The monthly averages of toward (

) and away (

) polarity groups have been calculated for each parameter. The solar and plasma parameters used in this work are the interplanetary magnetic field (

), sunspot numbers (

), and solar plasma speed (

), and the geomagnetic indices

,

, and

. We found that the wavelet power spectra (WPS) for the monthly averages of

and

nearly showed a symmetrical power spectra distribution. The global wavelet spectra (GWS) for

and

displayed a coupling at some level between 3.2–3.5, 10.7, and 18.3 yr of variations. The GWS for

provided two significant peaks, within the 95% confidence level, at 9.8 and 15.2 yr, as well as at 1 and 9.8 yr, for

. In addition, the existence of a periodicity of 1 yr is obvious for

spectra and it shifted to a 1.5 yr variation in

spectra. Both the WPS and GWS for

and

reflect symmetric power spectra for both groups in the northern and southern hemispheres. The

spectra exhibited prominent periodicities at 10.7 yr for

and 9.8 yr for

. Also, the well-known 9.8 yr periodicity variation is a dominant variation in both the spectra of

and

. On the other hand, within the cone of influence, the periodicities of 10.7 and 13.9 yr are observed for the

spectra and 9.8 yr for

spectra. The GWS showed double-peak structure for the spectrum of

.
The Physical Origin of the Venus Low Atmosphere Chemical Gradient
Authors: Cordier Daniel , Bonhommeau David A. , Port Sara , Chevrier Vincent , Lebonnois Sébastien , García-Sánchez Fernando
Published: July 2019

Venus shares many similarities with the Earth, but concomitantly, some of its features are extremely original. This is especially true for its atmosphere, where high pressures and temperatures are found at the ground level. In these conditions, carbon dioxide, the main component of Venus’ atmosphere, is a supercritical fluid. The analysis of VeGa-2 probe data has revealed the high instability of the region located in the last few kilometers above the ground level. Recent works have suggested an explanation based on the existence of a vertical gradient of molecular nitrogen abundances, around 5 ppm per meter. Our goal was then to identify which physical processes could lead to the establishment of this intriguing nitrogen gradient, in the deep atmosphere of Venus. Using an appropriate equation of state for the binary mixture CO2–N2 under supercritical conditions, and also molecular dynamics simulations, we have investigated the separation processes of N2 and CO2 in the Venusian context. Our results show that molecular diffusion is strongly inefficient, and potential phase separation is an unlikely mechanism. We have compared the quantity of CO2 required to form the proposed gradient with what could be released by a diffuse degassing from a low volcanic activity. The needed fluxes of CO2 are not so different from what can be measured over some terrestrial volcanic systems, suggesting a similar effect at work on Venus.
Coronal Loop Scaling Laws for Various Forms of Parallel Heat Conduction
Authors: Bradshaw Stephen J. , Emslie A. Gordon , Bian N. H. , Kontar Eduard P.
Published: July 2019

The solar atmosphere is dominated by loops of magnetic fluxes that connect the multi-million degree corona to the much cooler chromosphere. The temperature and density structure of quasi-static loops are determined by the continuous flow of energy from the hot corona to the lower solar atmosphere. Loop scaling laws provide relationships between global properties of the loop (such as the peak temperature, pressure, and length); they follow from the physical variable dependencies of various terms in the energy equation, and, hence, the form of the loop scaling law provides insight into the key physics that control the loop structure. Traditionally, scaling laws have been derived under the assumption of collision-dominated thermal conduction. Here, we examine the impact of different regimes of thermal conduction—collision-dominated, turbulence-dominated, and free-streaming—on the form of the scaling laws relating the loop temperature and heating rate to its pressure and half-length. We show that the scaling laws for turbulence-dominated conduction are fundamentally different than those for collision-dominated and free-streaming conduction, inasmuch as the form of the scaling laws now depend primarily on conditions at the low-temperature, rather than high-temperature, part of the loop. We also establish regimes in the temperature and density space in which each of the applicable scaling laws prevail.
Modelling Missile Flight Characteristics by Estimating Mass and Ballistic Parameters
Authors: Farlik J. , Hamtil I. , Kratky M.
Published: July 2019

This paper deals with one of the possible methods of a qualified estimation of tactical and technical parameters of surface-to-air or air-to-air guided missiles. This method is designed to estimate missile flight parameters if they are unavailable from public sources. Although the method does not provide exact values, it is sufficient for modelling and subsequent simulation. This method is based on the use of so-called “characteristic numbers” of the missile and on the assumption of validity of the hypothesis about the similarity of characteristic missile numbers of equal or, respectively, similar technological levels. To validate the obtained parameters, a method of mathematical modelling of the missile guidance process is used. The method can also be used for a qualified estimation of missile parameters in the case of an acquisition process.
Doravirine dose Selection and 96-Week Safety and Efficacy versus Efavirenz in Antiretroviral Therapy-Naive Adults with HIV-1 Infection in a Phase IIb Trial
Authors: Gatell Jose M , Morales-Ramirez Javier O , Hagins Debbie P , Thompson Melanie , Arastéh Keikawus , Hoffmann Christian , Raffi François , Osiyemi Olayemi , Dretler Robin , Harvey Charlotte , Xu Xia , Plettenberg Andreas , Smith Don E , Portilla Joaquín , Rugina Sorin , Kumar Sushma , Frobose Colleen , Wan Hong , Rodgers Anthony , Hwang Carey , Teppler Hedy
Published: July 2019

Background

The safety and efficacy of doravirine were compared with that of efavirenz as initial treatment of adults living with HIV-1 infection (NCT01632345).

Methods

A Phase IIb double-blind trial with participants stratified by screening HIV-1 RNA (≤ or >100,000 copies/ml) and randomized 1:1:1:1:1 to receive once-daily doravirine (25, 50, 100 or 200 mg) or efavirenz 600 mg (Part I) for up to 96 weeks, with open-label tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg (TDF/FTC). After dose selection at week 24, doravirine 100 mg was provided to participants receiving the other doses of doravirine and additional participants were randomized 1:1 to receive once-daily doravirine 100 mg or efavirenz 600 mg for 96 weeks with TDF/FTC (Part II). Primary outcomes were the proportion of participants with HIV-1 RNA <40 copies/ml at week 24, and central nervous system (CNS) adverse events (AEs) by weeks 8 and 24 (Parts I+II combined).

Results

210 and 132 participants were randomized in Parts I and II, respectively, and 216 (108 on doravirine 100 mg, 108 on efavirenz) were evaluable for Parts I+II combined. At week 24, the proportion of participants with HIV-1 RNA <40 copies/ml was 72.9% for doravirine 100 mg and 73.1% for efavirenz (difference −0.5 [95% CI −12.3, 11.2]). In addition, CNS AEs were reported by 26.9% and 47.2% of doravirine and efavirenz recipients, respectively (difference −20.4 [95% CI −32.6, −7.5]; P=0.002).

Conclusions

Doravirine 100 mg with TDF/FTC demonstrated similar antiretroviral activity and superior CNS safety compared with efavirenz 600 mg with TDF/FTC.
Community composition of ground beetles (Coleoptera, Carabidae) in citrus orchard in North-Eastern of Algeria
Authors: Ouchtati Nadia , Meliani Amel , Abdelkrim Asma , Kolli Zine Eddine
Published: July 2019

Carabid beetles are natural enemies of insects pests and are weed seeds predators. They have been often used to study the ecological effects of different agricultural measures, because they are highly sensitive to habitat change.

The Carabid beetle fauna is little known in Algeria, especially in agrosystems, thus we undertaken a study of this group of insects in citrus orchard located in the city of Guelma. Carabids were collected by pitfall trapping from december 2017 to may 2018. A total of 16 beetle species and 1072 individuals were recorded. The dominant species were consecutively as follows: Amara subconvexa , Brachinus sclopeta, Phyla rectangulum, Harpalus siculus and Percus lineatus.

The data of the species traits as food preference and flying ability show that carnivorous and macropterous species dominate in the study area. The activity of the species was mainly observed during the spring period.
Comparison of carabid beetles community between two cereal fields (treated and untreated) in north east of Algeria
Authors: Saouache Yasmina , Boumalit Saliha , Bouhdjar Insaf
Published: July 2019

The average yield of cereal crops increased by more than 98% worldwide and part of this dramatic yield increase is due to the increasing use of pesticides. Unfortunately, the use of phytosanitary products to eliminate pests has not spared some natural enemies of these crops.

Carabids beetles are important biological control agents in agroecosystems and are one of the most sensitive invertebrate groups to environmental disturbances such as use of pesticides or type of plowing. However, in the context of beetle diversity conservation and encourage biological control, we have undertaken a bioecological study of the carabid fauna in two cereal fields (treated and untreated) situated in the north est of Algeria. The beetles were sampled from april to june 2018.

Species richness and abundance values revealed a great difference between the two sampled area. We recorded 38 species and 332 individuals in the untreated field versus 18 species and 89 individuals in the treated field. The data of the species traits as diet, dispersal ability and habitat affinity show that predators, macropterous and xerophilic species dominate in both crops.
Diversity of plant-eating invertebrates as potential prey of carabid beetles in olive groves and vineyards in southern Croatia
Authors: Kos Tomislav , Anđelić Barbara , Jelić Mišel , Šerić Jelaska Lucija , Franin Kristijan
Published: July 2019

Predatory arthropods, among them carabid beetles (fam. Carabidae), play a key role in regulating the plant eating invertebrates in different agroecosystems. Croatian part of Mediterranean is extremely reach in biodiversity, and poorly investigated. Especially, studies on impact of different agricultural practices and use of various pesticides on diversity of beneficial predatory fauna and their trophic interactions have been scarce. Prior to molecular trophic analyses, we sampled invertebrate fauna, as a potential food for predatory arthropods, including carabid beetles, in olive groves and vineyards, both in ecological (EPM) and integrated (IPM) productions, and in pristine natural habitat, typical for that part of karst area. The knowledge on diversity and phenology of potential prey groups is important for developing molecular assays for detecting consumed species, and for better taxonomic resolution of consumed prey species accessed via DNA metabarcoding analysis of stomach content. During vegetation season in 2018 in hinterland of Zadar county “Ravni Kotari”, in southern Croatia, a survey in the canopy and the ground layer was done using yellow sticky traps Plantella©, beating net, pitfall traps and Tullgren funnels. Diversity indices were calculated for each collecting method and for each type of agroecosystem. Results showed that with betting net at least 16 groups, with Tullgren funnels at least 11 and 8 groups of potential invertebrate prey with yellow sticky trap was found. In olive groves 2 and in vineyards 3 of found plant eating groups, respectively could be economically important for production. Diversity and phenology on sites will be presented and discussed in details. This survey contributes to understanding diversity and phenology of different invertebrate prey groups in Mediterranean agroecosystems that could help in sustaining predatory carabids in the field under different pest control practice. The study was conducted under the project activity of HRZZ – Mediteratri and EU INTERREG CBC Pescar.
Effectiveness of Education Courses in Enhancing Clinical Educators' Teaching Ability
Authors: Liu Yong-bing , Xue Ling-ling , Xue Hui-ping , Hou Ping
Published: July 2019

Background:

In China, the nursing discipline has undergone rapid development in recent years, and clinical educators are an important part of the nursing education team. In order to improve their teaching ability and become competent clinical educators, we provided learning opportunities to them.

Method:

To assess the effectiveness of education courses and modules, a cross-sectional study based on questionnaire responses was conducted. Sixty-six part-time clinical nurse educators from six teaching hospitals were included. A standardized four-section questionnaire developed by the authors was used.

Results:

The education curriculum was approved by clinical educators (94%). The specific content in the education courses significantly improved the teaching ability (84%). From a teaching perspective, the confidence was enhanced; the clinical educators were able to control the purpose of teaching and learning objectives via a syllabus (92%).

Conclusion:

Education courses can improve teaching ability, reinforce teaching control, and promote the quality of clinical teaching.

[
J Contin Educ Nurs.
2019;50(8):367–373.]
Evaluating Transfer of Continuing Education to Nursing Practice
Authors: Bryant Tiffany , Posey Laurie
Published: July 2019

Background:

The nursing profession needs solid evidence of the important contributions that continuing education (CE) makes to nursing practice change. We analyzed nurses' intent to change practice, actual practice change, and examples of practice change after completing CE courses of differing types, topics, and geographic locations.

Method:

A retrospective, mixed-methods study design was used to assess quantitative and qualitative survey data gathered upon completion and within 1 year following completion of 16 different CE courses.

Results:

A large majority of nurses reported positive intent to change practice (88.6%) and actual practice change (89.1%) following participation in the CE courses. Qualitative analysis revealed four themes related to types of practice change, including Becoming Certified, Improved Leadership, Enhanced Role Performance, and Educating or Mentoring Others.

Conclusion:

CE can positively influence nursing practice change and lead to broader organizational improvements.[J Contin Educ Nurs.2019;50(8):375–380.]
The Effects of Timing of Soft Tissue Coverage on Outcomes After Reconstruction of Type IIIB Open Tibia Fractures
Authors: Clegg Devin J. , Rosenbaum Paula F. , Harley Brian J.
Published: July 2019

High-energy open fractures of the tibia are frequently associated with tissue loss, wound contamination, and compromised vascularity that often result in amputation. The management of these severe injuries remains a challenge for orthopedic reconstructive surgeons. Studies have compared the timing of soft tissue coverage of Gustilo type IIIB open tibia fractures with associated outcomes such as rate of deep infection, primary union, length of hospitalization, flap failure, and eventual secondary amputation. These studies often highlight better outcomes with specific time domains that are not always attainable at a large tertiary hospital with multi-system trauma patients. Many studies do not account for delayed patient transfers after initial open fracture management elsewhere. This retrospective analysis of the limb salvage outcomes included 140 consecutive patients with Gustilo type IIIB open tibia fractures who presented to the authors' level I trauma center between 2001 and 2014. The authors included patients who required delayed coverage or who were transferred from outside institutions. The majority (77%) were male, and the mean age was 39.4 years. Motor vehicle accidents were the most common cause of injury, and 83% of patients obtained full weight-bearing status with successful limb salvage. Twenty patients had a secondary amputation, with the cause being refractory osteomyelitis in 52%. This study provides guidance on treating a heterogeneous patient population with severe open tibia fractures typically seen in a large tertiary hospital orthopedic trauma service. [
Orthopedics
. 2019; 42(5):260–266.]
Femoral Head Vascularity: Implications Following Trauma and Surgery About the Hip
Authors: Gadinsky Naomi E. , Klinger Craig E. , Sculco Peter K. , Helfet David L. , Lorich Dean G. , Lazaro Lionel E.
Published: July 2019

Traumatic injury and surgical intervention about the hip joint place the arterial supply to the femoral head (FH) at risk. Compromised perfusion may lead to FH ischemia, cell death, and osteonecrosis. Progression to FH collapse may lead to pain, functional impairment, and decreased quality of life, especially in younger patients. This review describes the arterial supply to the FH, analyzes the impact of femoral neck fractures on FH vascularity, and explores the vascular implications of various surgical interventions about the hip, offering specific techniques to minimize iatrogenic damage to the vessels supplying the FH. [
Orthopedics
. 2019; 42(5):250–257.]
Minor Karst Landforms as an Indirect Method for Datation- the Case Study Valley Pod Košuto (Slovenia)
Authors: Mrak Irena
Published: July 2019

Prispevek obravnava pleistocensko morfogenezo doline Pod Košuto, ki je bila eno od območij detajlnega preučevanja pleistocenske morfogeneze porečja Tržiške Bistrice. Dolina izkazuje ledeniško preoblikovanje, genetsko problematično pa se je izkazalo karbonatno gradivo, ki se v večjem obsegu pojavlja na desni strani doline. S pomočjo litološke analize gradiva, meritev zaobljenosti gradiva ter z meritvami drobnih kraških denudacijskih oblik – mikrožlebičev ocenjujemo obdobje odložitve gradiva na sedanjem, sekundarnem mestuThe paper presents the Pleistocene morphogenesis research in the valley Pod Košuto. The area was one of the detailed studies in the wider research of the Pleistocene morphogenesis in Tržiška Bistrica river basin. Ice movements infl uenced the formation of valley Pod Košuto, but the research deals more with the genesis of the carbonate material that fi lls the right side of the valley. Researching the lithologic characteristics of the material, the measurements of particle roundness and with the help of the minor karst landforms measurements we offer the new view of the material deposition in the secondary – present location.
Fizikalno-kemične značilnosti voda v zaledju Malenščice (Slovenija)
Authors: Kogovšek Janja
Published: July 2019

Podane so osnovne fi zikalno-kemične značilnosti voda v zaledju Malenščice in povezave, ki jih nakazujejo. Dolomitna voda Cerkniščice odteka predvsem v Rak v Rakovem Škocjanu, Kotliči pa kažejo na povezavo s Svinjsko jamo in Malo Karlovico. Rak na ponoru predstavlja ob zelo nizkih vodostajih pretežno vodo Kotličev s Ca/Mg okoli 3,5 in z najnižjo vrednostjo 2,2 ob najnižjih vodostajih, ko v Svinjsko jamo ponika le Cerkniščica, kar se kasneje odrazi tudi v Malenščici. Ob visokih vodostajih v ponor odteka mešanica Raka in Kotličev s Ca/Mg okoli 4. Dotok voda iz doline Pivke označuje višje razmerje Ca/Mg in večje vrednosti pokazateljev onesnaženja, medtem ko označujejo infi ltracijsko vodo iz slabo prepustnega dela Javornikov vrednosti Ca/Mg okoli 5. Zaradi zapletenosti sistema ostaja še vrsta odprtih vprašanj, ki bi jih lahko pojasnile le dodatne raziskave. Basic physico-chemical properties of waters within the area of Malenščica are given, and so are the connections that they indicate. Dolomitic water of the Cerkniščica mostly fl ows into the Rak in Rakov Škocjan valley, while Kotliči springs show the connection with Svinjska jama (cave) and Mala Karlovica. When water levels are low the Rak river at its swallowhole mostly comprises waters from Kotliči, with Ca/Mg about 3, 5 and the lowest value 2,2 when the water levels are the lowest, when only the Cerkniščica sinks into Svinjska jama; this later reflects also in the water of the Malenščica. When water levels are high, the mixture of Rak and Kotliči fl ows into the swallowhole, and Ca/Mg is about 4. The infl ux of waters from Pivka Valley is designated by higher ratio of Ca/Mg and higher values of pollution indicators, when the infi ltration water from poorly conductive part of Javorniki is designated by Ca/Mg values about 5. Due to the complexity of the system there are still some unanswered questions left which can only be answered by carrying out additional researches.
Diversity of Culturable Bacteria and Meiofauna in the Epikarst of Škocjanske jame Caves (Slovenia)
Authors: Gerič Barbara , Pipan Tanja , Mulec Janez
Published: July 2019

Epikras postaja pomembno mesto hidrogeoloških, geomorfoloških in bioloških raziskav. Iz vzorcev pobranih s štirih mest v Škocjanskih jamah, kjer stalno kaplja voda z jamskega stropa, smo identifi cirali meiofavno. Na istih mestih so bili odvzeti tudi vzorci za izolacijo bakterij. Podatke o številu viabilnih celic smo dopolnili z morfološkimi in biokemijskimi lastnostmi izolatov. Izsledki kažejo, da v vzorcih prenikle vode iz epikrasa med bakterijami, ki jih lahko gojimo v in vitro razmerah, prevladujejo po Gramu negativne bakterije.The epikarst zone becomes an important site for hydrogeological, geomorphological and biological investigations. From the samples at four sites in Škocjanske jame caves where water tricklets constantly drip from the cave ceiling the meiofauna were identifi ed. The sites were screened also for the presence of culturable bacteria. The viable cell counts were supplemented with morphological and biochemical analysis of the isolates. Results show that Gram–negative bacteria prevail among culturable bacteria in the percolating epikarst waters.
High-Accuracy Graphic Representation of Underground Karst Features and Formations During Cave Mapping
Authors: Szunyogh Gábor
Published: July 2019

Prispevek predstavlja poskus razvoja nove metode kartiranja jam. Metoda nadgrajuje klasično kartiranje z večjo količino in natančnostjo podatkov, pri čemer predvideva, da na jamski načrt vnesemo vse kar v jami vidimo: korozijske oblike, vodna telesa, podorne bloke, razpoke v jamskih stenah, umetne posege v jamo itd. Metoda uporablja tradicionalen nabor simbolov, pri čemer ločljivost ustreza ločljivosti inženirskih načrtov. Na karti so natančno predstavljene lokacija, oblika in dimenzija jamskih oblik; npr. vsi stalagmiti z premerom nad 10 cm in vsi bloki z linearno dimenzijo nad 0.5 m so posamično prikazani. Prispevek obravnava najpomembnejše vidike te metode, predstavi različne faze meritev in kartiranja, način risanja in kartografske simbole.We attempt to develop a new method of cave mapping, which would be superior in terms of the amount and quality of the documented information, relative to the “standard” methods of cave survey. The method envisages that everything that can be seen in the cave which is being surveyed, e.g., corrosional features, cave formations, water bodies, fallen rock blocks, fractures in cave walls, artifi cial (engineering) structures, etc., must be represented on the map. The method employs the traditional system of map symbols; the accuracy of the produced map, however, approaches the accuracy of the engineering survey maps. The maps accurately render positions, shapes and dimensions of cave features: for example all stalagmites with diameters greater than ca. 10 cm, and all rock blocks with linear sizes exceeding 0.5 m are shown on the maps individually. In the report we will elaborate on the most important aspects of this mapping method, including stages of survey and mapping, system of drawing, map symbols.
Low Cycle Fatigue Life Evaluation According to Temperature and Orientation in Nickel-Base Superalloy
Authors: Heo In Kang , Yoon Dong Hyun , Kim Jae Hoon
Published: July 2019

Components of gas turbines must be extremely resistant to high temperatures, high stresses, high-temperature corrosion, and erosive environments. The materials used in these environmental conditions are mainly nickel-based superalloys. In this study, the low-cycle fatigue of the nickel-based superalloy Inconel 792 was examined. The total strain range of a gas turbine between 760 °C and 870 °C was considered as the parameter representing the actual gas turbine operation. In addition, tests were performed using a trapezoidal waveform of the total strain to reflect the operation-stop conditions of a gas turbine with frequent shutdowns. The results of the fatigue test were compared with the Coffin–Manson method and energy method. The fractured surface was analyzed using a scanning electron microscope (SEM).
Control of Microstructure and Properties of Welded Joints of Heavy Structures of Low Alloy High Strength Steels
Authors: Wang Zhi Ling
Published: July 2019

In order to prevent the cold cracking of the welded joints and the overheating of the heat affected zone of the welded joints of the heavy and heavy parts of low alloy high strength steels, We have carefully studied the welding materials and methods for heavy parts of alloy high strength steel. We should pay attention to the preparation before welding, strictly control welding energy parameters, temperature parameters and operation parameters, adjust welding line energy and preheating temperature, control welding heat cycle, and adopt appropriate post-weld heat treatment and post-weld inspection process measures. By improving and optimizing the welding technology of heavy and heavy parts of low alloy high strength steel, we can effectively avoid the cold crack and overheating of heat affected zone in the welding of heavy and heavy parts of low alloy high strength steel, and greatly improve the mechanical properties of welded joints.
Pressing and Bonding Strength of Metal Matrix Composite
Authors: Dai Ya Chun , Wang Hai , Yang Chao , Jiang Ding
Published: July 2019

This article aims to improve the bonding strength between metal and plastic,the metal substrate is subjected to high-energy shot peening to make the surface self-nitrified, and the orthogonal test scheme was designed based on the process parameters of high energy shot peening and spraying. After molding, the bonding strength of the metal matrix composite was tested by the vertical stretching method. We studied the effect of the cast steel shot diameter, the shot peening pressure, the shot peening time and the plasticizing temperature on the bonding strength of the composite. The combination of process parameters was determined when the bonding strength was optimized, then use the numerical fitting method to predict the combination of process parameters when the bonding strength is the highest, the optimization results are verified by experiments. The results show that the diameter of the cast steel shot is 4.96mm-5.04mm, the shot peening pressure is 0.49MPa-0.51MPa, the shot peening time is 10.9min-11.08min, and the plasticizing temperature is 278.2°C-282°C. The bonding strength of the composite is optimal Keywords: Metal matrix composite, High-energy shot peening, Press forming; Bonding strength, Process optimization
Throughput Estimation Model of Cluster Tool in Semiconductor Manufacturing
Authors: Tu Ying Mei
Published: July 2019

Semiconductor manufacturing management system was developed and grown up over the past decades. In order to increase the product yield and enhance the production productivity, cluster tools became the main stream in modern wafer fabrication factories which occupies over 50% of production equipment. Generally, cluster tools are integrated by several components including robots, vacuum chambers (Load locks) and single-wafer process chambers in a module and can be treated as a small factory. The throughput estimation before recipe release is very difficult. However, it is necessary and important for the planning activity. In this work, a throughput estimation model for cluster tools is proposed. The Multiple Regression Analysis is applied to develop a set of throughput estimation equations. A simulation model of cluster equipment including 3 single-wafer process chambers are built to get the historical throughput data for the regression analysis. From the Multiple Regression Analysis, it reveals that different numbers of recipes processed in the same time have to develop different regression model. The major factors in the regression model include numbers of load ports and process time of each recipe. Furthermore, a set of recipes are used to test the accuracy of estimation. Based on the testing results, they revealed that the MAPE is under 3% and the estimation model is accepted in practice to forecast the throughput of recipes for the planning activities.
An Intelligent Optimization System for PIM Process
Authors: Chen Wen Chin , Chen Tai Hao , Chang Ding Tsair , Nguyen Manh Hung
Published: July 2019

This study proposes an intelligent optimization system based on the Taguchi method, back-propagation neural network (BPNN), multilayer perceptron (MLP) and modified PSO-GA to find optimal process parameters in plastic injection molding (PIM). Firstly, the Taguchi method is used to determine the initial combination of parameter settings by calculating the signal-to-noise (S/N) ratios from the experimental data. Significant factors are determined using analysis of variance (ANOVA). The S/N ratio predictors (BPNNS/N) and quality predictors (BPNNQ) are constructed using BPNN with the experimental data. In addition, a modified PSO-GA algorithm in conjunction with MLP is used to find initial weights of BPNN and to reduce the training time of BPNN. In the first stage optimization, the S/N ratio predictors are coupled with GA to reduce the variations of the manufacturing process. In the second stage optimization, The combination of S/N ratio predictors and quality predictors with modified PSO-GA is empoyed to search for the optimal parameters. Finally, three confirmation experiments are performed to assess the effectiveness of these approaches. The experimental results show that the proposed system can create the best performance, and optimal process parameter settings which not only enhance the stability in the whole injection molding process but also effectively improve the PIM product quality. Furthermore, experiences of the novel hybrid optimization system can be transferred into the intelligent PIM machines for the coming up internet of things (IoT) and big data environment.
Effect of Different Aging System on Microstructure and Mechanical Properties of X2A66 Alloy
Authors: Xu Jin Jun , Guan Rui Chun , Jiang Mang
Published: July 2019

Through a series of mechanical properties tests and microstructure observation, the effects of artificial heat treatment (AA), pre-stretching aging (PA) and pre-stretching creep aging (PCA) treatment on the precipitation phase type and mechanical properties of X2A66 aluminum-lithium alloy were studied. The results show that compared with AA, PA treatment promotes the uniform precipitation of high-density T1 phase, so that the yield strength, tensile strength and elongation of the alloy reach 593.4Mpa, 610.8Mpa, 10.7%. Further, the creep aging treatment on the basis of the pre-deformation can further increase the strength (613.6Mpa, 628.9Mpa) of the alloy with a slight decrease in the elongation (10.3%).
Synthesis and Clay Anti-Swelling Properties of Diethyl Dodecyl Allyl Ammonium Chloride
Authors: Ma Yu Liang , Xie Rui Jie , Zheng Huan , Zhu Chan
Published: July 2019

In order to protect the oil&gas reservoirs, a surfactant vinyl cationic clay (Na-MMT) anti-swelling agent diethyl dodecyl allyl ammonium chloride (DDAAC) was prepared from diethylamine, chlorododecane and allyl chloride as raw materials. The single-factor orthogonal test was used to determine the optimal synthesis scheme for DDAAC: reaction temperature 40 °C; reaction time 4 h; pH= 9; n (diethylamine): n(chlorododecane): n(allyl chloride) = 1.1:1.0:1.8. The experimental results showed that the anti-expansion rate of 0.5wt% DDAAC can reach to 78.31%. FT-IR were utilized to study its anti-expansion mechanism, and FT-IR showed that physicochemical adsorption between DDAAC and Na-MMT occurs.
Microstructure Investigation of He+- Implanted and Post-Implantation-Annealed 4H-SiC
Authors: Zhang Li Qing , Liu Hui Ping , Kang Long , Zhang Tong Min , Chen Yu Guang , Zhang Xian Long , Ding Zhao Nan , Li Jian Yang , Liu Juan , Li Jin Yu , Zhang Chong Hong
Published: July 2019

Microstructure damage and evolution in 4H-SiC under He-ion implantation and post-annealing have been investigated by the combination of fourier transform infrared spectrometer (FTIR), Raman scattering spectroscopy and high resolution X-ray diffractometer (HRXRD). After implantation, the 4H-SiC specimen exhibits a heavy damage and some amorphous state appear. With increasing annealing temperature, to some extent recovery in damaged lattices was observed, as a result of the peaks of Raman and HRXRD regain their intensities. However, the reverse annealing behavior in damaged peaks was displayed after annealed at 973K. This reverse annealing effect was revealed to be due to the formation and the growth of He bubbles above 973K.
Thermal Management of a Li-Ion Battery for Electric Vehicles Using PCM and Water-Cooling Board
Authors: Yu Gu Yu , Chiang Sum Wai , Chen Wei , Du Hong Da
Published: July 2019

A novel thermal management system (TMS) for Li-ion battery module using phase change material (PCM) and cooling water as the heat dissipation source to control battery temperature rise has been developed. Graphite sheets were applied to compensate low thermal conductivity of battery and PCM and improve temperature uniformity of the batteries. One discharge (1C rate)-charge (2C rate) circle was applied in battery modules to test the effectiveness of this TMS. A three dimensional numerical model of the battery module with the TMS was conducted. The results show that this TMS basically meets the demand about the maximum temperature difference of battery module and totally keeps the maximum temperature within the optimum operating temperature range (≤45°C).
Multilayered Elastic Medium under Axisymmetric Loading and Surface Energy
Authors: Tarntira Kanin , Senjuntichai Teerapong , Keawsawasvong Suraparb
Published: July 2019

This paper presents a solution scheme for analysis of a multilayered elastic medium under axisymmetric loading and surface energy effects by adopting Gurtin-Murdoch surface elasticity theory. Love’s strain function and Hankel integral transform are employed to derive the general solutions, and the obtained solutions are employed in the determination of the stiffness matrix for each layer. The global stiffness equation of a multi-layered system is assembled by considering the continuity of traction and displacements at each layer interface. The numerical solutions to the global equation yield displacements and stresses at the interfaces of the layered medium under axisymmetric loading. The accuracy of the proposed solution scheme is verified by comparing with existing solutions. Selected numerical results are presented to demonstrate a significant influence of surface energy on elastic fields of a multilayered elastic medium under axisymmetric loading.
Antibacterial Properties among Different Concentration of Bioactive Glasses
Authors: Wanitwisutchai Tanawan , Monmaturapoj Naruporn , Srisatjaluk Ratchapin , Subannajui Kittitat , Anuwongnukroh Niwat , Dechkunakorn Surachai , Pongprueksa Pong
Published: July 2019

The objective of this study was to evaluate the antibacterial properties and pH changes of bioactive glasses and zinc oxide nanowire in different concentrations. Bioactive glasses (45S5 and 45S5F) were prepared in three concentrations of 10, 20, and 50 mg/ml and zinc oxide nanowire was prepared in 1 and 5 mg/ml concentrations. The materials were exposed to 500 ml brain heart infusion broth (BHI) with 1.5 x 107 of S.mutans and S.sanguinis separately. Antibacterial properties were tested indirectly by collecting 100 ml of each sample and transferred into a 96 well-plate. The optical density (OD) was evaluated using spectrophotometry at 630 nm at 24h and 48h. The pH changes were recorded. The data were statistically analyzed by Kruskal-Wallis tests. The result showed that the pH changes were significantly different in the Bioactive glass samples, while zinc oxide nanowire showed stable pH. Antibacterial activity against S.mutans was significant lower for 45S5 at 50 mg/ml, 45S5F and zinc oxide nanowire in all concentrations at 24 h. While in 48 h, 45S5, 45S5F and zinc oxide nanowire showed significant antibacterial activity in all concentration except 45S5F at 10 mg/ml. Antibacterial activity against S.sanguinis was significant for 45S5 and 45S5F at 20 and 50 mg/ml and zinc oxide nanowire in all concentration at 48h. It can be concluded that Bioactive glasses (45S5 and 45S5F) exhibited antibacterial properties and pH changes depending on its concentration, while zinc oxide nanowire exhibited antibacterial properties at low concentrations with a constant pH value.
Synthesis of Diamond-Like Structures by Method of Mechanochemical Treatment of Nano-Carbon Materials (Taunit)
Authors: Chaika Victoriia A. , Savin Valeriy V. , Savina Ludmila A. , Osadchy Alexander V. , Zherebcov Ivan S.
Published: July 2019

The structural and phase changes in the carbon nanomaterial of the “Taunit” series were studied depending on the time of mechanochemical treatment (MCT) in a high-speed ball mill. The possibility of the formation of a carbon material with an amorphous and diamond-like component is shown.
Rebar Anchor Plate Research and Application
Authors: Shao Kang Jie , Li Zhi Bin , Zhang Zhuo Qun
Published: July 2019

Recently, rebar anchor plate has been widely used in the project, which solve the rebar anchor problem and improve the construction quality. This paper introduced the rebar mechanical anchorage technology background, research content and progress, and rebar anchor plate application, which would offer the guidance and reference for the designers and constructors.
Evaluation on Sulfuric Acid Resistance of Concrete Protected by Biomimetic Coating Mortar
Authors: Yoon Hyun Sub , Yang Keun Hyeok
Published: July 2019

The objective of this study is to evaluate the sulfuric acid resistance of the concrete coated with bacterial-glycocalix-based biomimetic coating mortar. The variation of the compressive strength and mass of the coated concrete since the specimen was immersed into an aqueous solution of 5 % sulfuric acid were 0.88 and 12 % at the age of 56 days, respectively, showing a superior deterioration resistance. As a result, it can be concluded that the developed biomimetic coating mortar possesses a great potential for enhancing the deterioration resistance performance of concrete.
Synthesis of Cerium Phosphate White Pigments from Cerium Oxalate
Authors: Onoda Hiroaki , Tanaka Rie
Published: July 2019

Catalytically active cerium dioxide is used as light reflection materials for cosmetic applications. Therefore, cosmetics containing this pigment too much cause oxidation of the skin. Therefore, the substitute for cerium dioxide is required to prepare the cosmetics without catalytic activity. Herein, as novel white pigments for use in cosmetics, cerium phosphates were prepared from cerium oxalate under various conditions. The chemical composition, powder properties, catalytic activity, color phase, and smoothness of the cerium phosphates were evaluated. All samples had weak unknown peaks in XRD patterns. Samples prepared at high temperature and for long time indicated the peaks of phosphate in IR spectra. Samples prepared in this work had no photo and oxidation catalytic activities. Samples prepared at high temperature and for long time indicated enough high whiteness and high smoothness.
Desorption of Mercury Complex from Fe-Modified Montmorillonite Adsorbent Membrane
Authors: Lodo Marjorie Jane , Diaz Leslie Joy L.
Published: July 2019

With the use of nanotechnology, clay minerals, specifically montmorillonites, have been reengineered to be used in environmental remediation, especially in the treatment of mining wastewater containing hazardous heavy metal ions. The objective of this study is to assess the practicality of using iron-modified montmorillonite (Fe-MMT) nanomembranes in the removal of mercury using the adsorption process. The nanomembranes, which were synthesized via electrospinning, were subjected to mercury cyanide solutions during the batch adsorption set ups to determine the adsorption efficiency. During the subsequent elution tests, three factors– eluent type (CH3COOH and C6H807), eluent concentration (0.01 M and 0.05 M) and contact time (3 and 5 hours) – were tested. SEM images of the mats were acquired to study the structure of the adsorbent. HD XRF analysis was done to identify the ions present in the membrane, as well as the initial Hg concentrations, amount of remaining Hg in the wastewater after batch adsorption and amount of desorbed metal. Results showed that using the Fe-MMT nanomembrane as adsorbent material resulted to 61.74% removal of Hg in the mercury cyanide solutions with initial concentrations of 13.87 to 38.9 mg L-1. Acetic acid exhibited better desorption results, with the highest efficiency of 31.36% (0.01 M, 5 h) compared to citric acid’s 7.40% (0.05M, 3 h).
Optical and Electrical Properties of Diamond-Like Carbon Thin Film with Deposition by ECR-CVD System
Authors: Srisantirut Tanawit , Pengchan Weera
Published: July 2019

In this paper, evolution of optical and electrical properties of diamond-like carbon (DLC) films deposited by ECR-CVD system are reported. By varying the deposition different substrates bias (0, -55, -100 V) and volume amount of C2H2 from 40 to 55 cc onto substrate Si/TiN and quarts. The structure of the DLC films were analyzed from Raman spectroscopy. DLC films deposited bias at-100 V and C2H2 at 40 cc show excellent optical transmittance and high resistivity. As a result, ID/IG ratio corresponds to the optical transmittance and resistivity with ID/IG ratio decreased making the film like to the diamond. Most importantly, the transparency and resistivity properties of the DLC films can be tailored to approaching diamond by adjusting substrates bias and volume C2H2, is important to many applications, which is improve film properties.
Study on Source Analysis of the Cation in Produced Water from Sulige Gas Field and Anti-Scaling Measures
Authors: Chang Peng , Shi Rui Xue , Wang Li , Han Wei , Ye Cong Dan , Ma Yun
Published: July 2019

A large amount of foreign matter appears in the Sulige gas well, causing blockage and corrosion of the pipeline, increasing the pressure difference in the wellbore and seriously affecting the normal production of the gas well. The gas wells with serious conditions mentioned above were selected to analyze the quality of single well produced water and the composition of blockage and core. Combined with the XRD analysis results of the cuttings, the long-term leaching experiments on the cuttings in different simulated solutions were carried out to study the sources of scaled ions in the gas wells. The experimental results showed that the extracted water from SD6-1 had high salinity and high content of scale ions Ca2+, Ba2+ and Sr2+;the main component of blockage is the acid insoluble strontium sulfate (barium) scale, and contains a small amount of corrosion products. The easily scalable Ca2+、Mg2+、Ba2+ and Sr2+ produced from the dissolution of the core in the formation water or working fluids, especially the acid erosion dissolves. According to the scaling mechanism, two kinds of Sr/Ba scale inhibitor were selected. The results showed that the barium II scale inhibitor performance is relatively good, and at the concentration of 40 mg/L, and the scale inhibition rate was more than 95%. The clogging of a single well can be reduced by adding a scale inhibitor.
Catalytic Cracking of Oleic Acid over Zeolites
Authors: Kanak Md Amirul Alam , Park Ji Yeon , Lee In Gu
Published: July 2019

Compared with bio-oil from sawdust (common lignocellulosic biomass), the bio-oil obtained by fast pyrolysis of coffee waste has a unique feature to contain a significant amount of fatty acids such as oleic acid and palmitic acid. It is necessary to conduct C-C cracking of fatty acids present in coffee-waste bio-oil to maximize gasoline fraction (C5-C12) production. In this work, catalytic cracking of oleic acid as a model compound for the fatty acids was carried out in batch reactors to understand the effect of major parameters such as zeolite type (HZSM-5, SAPO-11, MCM-41), reaction temperature (380-500 °C), and reaction time (0-50 min) on gasoline fraction production. The GC-MS analysis showed hydrocarbons and aromatics to be major compounds present in the gasoline fraction irrespective of zeolite type and reaction conditions. At 400 °C and 0 min reaction time, the yield of gasoline fraction was 18.6, 6.7, and 33.1 % with HZSM-5, SAPO-11, and MCM-41, respectively. As reaction temperature increased to 500 °C, the total gasoline fraction yield reached 43.7 and 22.7 % with SAPO-11 and MCM-41, respectively. In all the catalysts, the content of aromatic compounds in the gasoline fraction increased with the increase in reaction temperature and reaction time. Meanwhile, the formation of hydrocarbons in the gasoline fraction showed different optimum temperature with catalyst: 11.8 % yield with SAPO-11 at 500 °C and 27.0 % yield with MCM-41 at 400 °C.
Effect of Extraction Process on Extraction Yeild, Total Polyphenol Content and Antioxidant Activity of Jasminum Subtriplinerve
Authors: Anh Trieu Tuan , Hao Luu Tu , Bach Long Giang , Nguyen Duy Chinh , Lam Tri Duc
Published: July 2019

Jasminum Subtriplinerve Blume (Oleaceae) is herbal plants widely a tea for weight loss, stimulates milk glands. Extract product it easy used yet had little research. This study was carried out to evaluate the effect of extracting conditions such as water/material ratio, extraction temperature and extracting time on extracting yield, polyphenol content and antioxidant activity of J.subtriplinerve extract. The total phenolic compounds were determined according to the Folin–Ciocalteu method. Extraction yield (0.22g/100 g) was obtained at water/material ratio 15:1 (ml/g), 40°C and 4 hours extraction time. Under these optimized conditions, the polyphenol content of was 2640.4 μg/1g extract. And the extract can harvest 46.11 % of DPPH (30 μg/ mL) at 10 000 μg/ml concentration