bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of marine eukaryote evolution on phosphorus, carbon and oxygen cycling across the Proterozoic–Phanerozoic transition
Authors: Lenton Timothy M. , Daines Stuart J.
Published: June 2018

A ‘Neoproterozoic oxygenation event’ is widely invoked as a causal factor in animal evolution, and often attributed to abiotic causes such as post-glacial pulses of phosphorus weathering. However, recent evidence suggests a series of transient ocean oxygenation events ∼660–520 Ma, which do not fit the simple model of a monotonic rise in atmospheric oxygen (pO2). Hence, we consider mechanisms by which the evolution of marine eukaryotes, coupled with biogeochemical and ecological feedbacks, potentially between alternate stable states, could have caused changes in ocean carbon cycling and redox state, phosphorus cycling and atmospheric pO2. We argue that the late Tonian ocean ∼750 Ma was dominated by rapid microbial cycling of dissolved organic matter (DOM) with elevated nutrient (P) levels due to inefficient removal of organic matter to sediments. We suggest the abrupt onset of the eukaryotic algal biomarker record ∼660–640 Ma was linked to an escalation of protozoan predation, which created a ‘biological pump’ of sinking particulate organic matter (POM). The resultant transfer of organic carbon (Corg) and phosphorus to sediments was strengthened by subsequent eukaryotic innovations, including the advent of sessile benthic animals and mobile burrowing animals. Thus, each phase of eukaryote evolution tended to lower P levels and oxygenate the ocean on ∼104 year timescales, but by decreasing Corg/P burial ratios, tended to lower atmospheric pO2 and deoxygenate the ocean again on ∼106 year timescales. This can help explain the transient nature and ∼106 year duration of oceanic oxygenation events through the Cryogenian–Ediacaran–Cambrian.
Heterogeneous and dynamic marine shelf oxygenation and coupled early animal evolution
Authors: Li Chao , Cheng Meng , Zhu Maoyan , Lyons Timothy W.
Published: June 2018

It is generally agreed that early diversification of animals and significant rise of atmospheric and oceanic oxygen (O2) levels occurred in the Ediacaran (635–541 million years ago, Ma) and early Cambrian (ca. 541–509 Ma). The strength and nature of their relationship, however, remain unclear and debated. A recent wave of paleoredox research — with a particular focus on the fossiliferous sections in South China — demonstrates high spatial heterogeneity of oceanic O2 (redox) conditions and dynamic marine shelf oxygenation in a dominantly anoxic ocean during the Ediacaran and early Cambrian. This pattern shows a general spatiotemporal coupling to early animal evolution. We attribute dynamic shelf oxygenation to a complex interplay among the evolving atmosphere, continents, oceans, and biosphere during a critical period in Earth history. Our review supports the idea of a complex coevolution between increasing O2 levels and early diversification of animals, although additional work is required to fully delineate the timing and patterns of this coevolution and the mechanistic underpinnings.
Animal origins and the Tonian Earth system
Authors: Mills Daniel B. , Francis Warren R. , Canfield Donald E.
Published: June 2018

The Neoproterozoic Era (1000–541 million years ago, Ma) was characterized by dramatic environmental and evolutionary change, including at least two episodes of extensive, low-latitude glaciation, potential changes in the redox structure of the global ocean, and the origin and diversification of animal life. How these different events related to one another remains an active area of research, particularly how these environmental changes influenced, and were influenced by, the earliest evolution of animals. Animal multicellularity is estimated to have evolved in the Tonian Period (1000–720 Ma) and represents one of at least six independent acquisitions of complex multicellularity, characterized by cellular differentiation, three-dimensional body plans, and active nutrient transport. Compared with the other instances of complex multicellularity, animals represent the only clade to have evolved from wall-less, phagotrophic flagellates, which likely placed unique cytological and trophic constraints on the evolution of animal multicellularity. Here, we compare recent molecular clock estimates with compilations of the chromium isotope, micropaleontological, and organic biomarker records, suggesting that, as of now, the origin of animals was not obviously correlated to any environmental–ecological change in the Tonian Period. This lack of correlation is consistent with the idea that the evolution of animal multicellularity was primarily dictated by internal, developmental constraints and occurred independently of the known environmental–ecological changes that characterized the Neoproterozoic Era.
Reduced‐reference quality metric based on local sharpness measure for blurred images
Authors: Lee L.K. , Yoon Y.B. , Kim S.W.
Published: June 2018

A simple yet robust reduced‐reference quality metric based on local sharpness measure for blurred images in discrete cosine transform (DCT) domain is introduced. As a single feature to represent the quantification of blur in an image, a global image sharpness is quantified from the local sharpness with a selected optimal subset of DCT coefficients in each overlapped block in the feature extraction process. Then, the final objective quality score is simply calculated by division by the reference value in the quality analysis process. The experimental results on three public quality assessment databases demonstrate the proposed method correlates highly with human subjective judgements and outperform other methods consistently in terms of prediction accuracy and monotonicity for a wide range of blurriness.
Deep hashing network for material defect image classification
Authors: Yang Kai , Sun Zhiyi , Wang Anhong , Liu Ruizhen , Sun Qianlai , Wang Yin
Published: June 2018

Common non‐destructive material testing technology has some well‐known problems such as slow detection, low detection accuracy, and low level of information obtained. To solve these problems, this study applied recent advances in convolution neural networks to propose an effective deep learning network using casting datasets. The approach achieves non‐destructive material testing with automatic, intelligent detection technology. For most existing deep learning networks, an image is eventually transformed into a multidimensional visual feature vector for comparison and classification. However, such vectors may not optimally improve detection precision and speed, and can lead to significant storage problems. A deep hashing network is proposed in which images are mapped into compact binary codes. There are three key components: (i) a sub‐network with multiple convolution‐pooling layers to capture image representations; (ii) a hashing layer to generate compact binary hash codes; (iii) an encoder module to divide the image feature vector from the output of the sub‐network above into multiple branches, each encoded into one hash bit. Extensive experiments using a casting dataset show promising performance compared with the state‐of‐the‐art approach.
Capacity‐enhancement in MIMO systems using biomimetic electrically small antenna arrays
Authors: Ranjbar Nikkhah Mohammad , Panahi Mohammad Ali , Luyen Hung , Bahrami Hamid , Behdad Nader
Published: June 2018

The authors investigate the performance of multi‐input–multi‐output (MIMO) communications systems that exploit biomimetic antenna arrays (BMAAs) with electrically small‐aperture dimensions. By exploiting the mutual coupling between closely spaced radiating elements and extracting the maximum available power from all excitation modes of the array, BMAAs can significantly outperform conventional antenna arrays with similar aperture sizes. As a proof of concept demonstration, they examine the use of two‐element BMAAs consisting of two monopole antennas with variable element spacing in an MIMO system. The capacity of MIMO systems using such BMAAs is compared with those that use conventional antenna arrays with the same element types and spacing. Their simulation results demonstrate that using BMAAs can offer considerable capacity enhancements in an MIMO system. To experimentally verify these results, a prototype of a two‐element BMAA operating at 615 MHz with element spacing of and a regular array prototype with similar antenna elements and dimensions are fabricated and characterised. The performance of MIMO systems using these two antennas is modelled using numerical channel modelling using the measured antenna responses. These results are found to be in good agreement with theoretical predictions.
Interference detection algorithm based on adaptive subspace tracking and RAIM for GNSS receiver
Authors: Wu Qiang , Zheng Jiansheng , Dong Zhicheng , Su Mingkun , Liang Hexi , Zhang Ping
Published: June 2018

The authors aim at providing an interference detection algorithm for global navigation satellite system (GNSS) receivers based on the adaptive subspace tracking technique and receiver autonomous integrity monitoring (RAIM). A complete framework, including an estimator used to determine the number of interference sources and a method for detecting the interference frequency, is presented in the narrowband interference environment. The estimator, applying both the eigenvalues’ statistic characteristics of sample covariance matrix and the noise level of GNSS receiver, is more accurate than the conventional information theoretic criteria with simulation verification. Furthermore, the proposed subspace tracking algorithm outperforms the current frequency detection algorithms in time–frequency domain, such as short‐time Fourier transform and smooth pseudo‐Wigner‐Ville distribution. The theoretical analysis is verified by the real experiments under a GPS L1 scenario.
Production of silica nanoparticles bound fabrics and evaluation of its antibacterial/ultraviolet protection properties
Authors: Rethinam Senthil , Ramamoorthy Rajalakshmi , Robert Berly , Nallathambi Gobi
Published: June 2018

Manufacture of microbe‐resistant clothing is the need of the hour especially in microbe sensitive environments such as hospitals. Silica nanoparticles (SiO2) were prepared from xerogels synthesised from cotton pods. In the present work, a novel fabric was prepared using SiO2, non‐woven cotton fabrics and polyethylene glycol (PEG). Different types of fabrics were prepared by incorporating different concentrations of the SiO2. Among the fabrics, 3% exhibited significant antimicrobial activity. The smooth surface morphologies of the fabric were proved by scanning electron microscopy. Fourier transform infrared spectroscopy spectrum of fabric represented the characteristic bands of all the components, i.e. SiO2, PEG and cotton fibre. A potential fabric, which possesses microbe‐resistant property, and hence they could be of promising use in medical cloths production.
Radial velocity follow-up of GJ1132 with HARPS
Authors: Bonfils X. , Almenara J.-M. , Cloutier R. , Wünsche A. , Astudillo-Defru N. , Berta-Thompson Z. , Bouchy F. , Charbonneau D. , Delfosse X. , Díaz R. F. , Dittmann J. , Doyon R. , Forveille T. , Irwin J. , Lovis C. , Mayor M. , Menou K. , Murgas F. , Newton E. , Pepe F. , Santos N. C. , Udry S.
Published: June 2018

The source GJ1132 is a nearby red dwarf known to host a transiting Earth-size planet. After its initial detection, we pursued an intense follow-up with the HARPS velocimeter. We now confirm the detection of GJ1132b with radial velocities alone. We refined its orbital parameters, and in particular, its mass (mb = 1.66 ± 0.23 M⊕), density (ρb = 6.3 ± 1.3 g cm−3), and eccentricity (eb < 0.22; 95%). We also detected at least one more planet in the system. GJ1132c is a super-Earth with period Pc = 8.93 ± 0.01 days and minimum mass mc sinic = 2.64 ± 0.44 M⊕. Receiving about 1.9 times more flux than Earth in our solar system, its equilibrium temperature is that of a temperate planet (Teq = 230−300 K for albedos A = 0.75 − 0.00), which places GJ1132c near the inner edge of the so-called habitable zone. Despite an a priori favorable orientation for the system, Spitzer observations reject most transit configurations, leaving a posterior probability <1% that GJ1132c transits. GJ1132(d) is a third signal with period Pd = 177 ± 5 days attributed to either a planet candidate with minimum mass md sin id = 8.4−2.5+1.7 M⊕ or stellar activity. Its Doppler signal is the most powerful in our HARPS time series but appears on a timescale where either the stellar rotation or a magnetic cycle are viable alternatives to the planet hypothesis. On the one hand, the period is different than that measured for the stellar rotation (~125 days), and a Bayesian statistical analysis we performed with a Markov chain Monte Carlo and Gaussian processes demonstrates that the signal is better described by a Keplerian function than by correlated noise. On the other hand, periodograms of spectral indices sensitive to stellar activity show power excess at similar periods to that of this third signal, and radial velocity shifts induced by stellar activity can also match a Keplerian function. We, therefore, prefer to leave the status of GJ1132(d) undecided.
Spectroscopic characterization of the protocluster of galaxies around 7C 1756+6520 at z ~ 1.4
Authors: Casasola V. , Magrini L. , Combes F. , Sani E. , Fritz J. , Rodighiero G. , Poggianti B. , Bianchi S. , Liuzzo E.
Published: June 2018

Aims. The aim of this paper is the spectroscopic study of 13 galaxies belonging to the field of the protocluster associated with the radio galaxy 7C 1756+6520 at z = 1.4156. In particular, we focus on the characterization of the nuclear activity.

Methods. This analysis has been performed on rest-frame optical spectra taken with the Large Binocular Telescope, using the spectrograph LUCI, which is operative in the near-infrared domain. The adopted spectral coverage allowed us to observe emission lines such as Hα, Hβ, [O III]λ 5007 Å, and [N II]λ 6583 Å at the redshift of the central radio galaxy. We observed the central part of the protocluster, which is suitable to include the radio galaxy, several spectroscopically confirmed active galactic nuclei (AGN) belonging to the protocluster, and other objects that might be members of the protocluster.

Results. For four previously identified protocluster members, we derived the redshift by detecting emission lines that have never detected before for these galaxies. We identified a new protocluster member and eight new possible protocluster members. The stacked spectrum of the galaxies in which we detected the [O III]λ 5007 Å emission line revealed the second line of the [O III] doublet at 4959 Å and the Hβ line, which confirms that they belong to the protocluster. By collecting all members identified so far in this work and other members from the literature, we defined 31 galaxies, including the central radio galaxy, around the redshift 1.4152 ± 0.056. This corresponds to peculiar velocities ≲5000 km s−1 with respect to the radio galaxy. The position versus velocity phase-space diagram suggests that three AGN of the protocluster and the central radio galaxy might be a virialized population that has been coexisting for a long time in the densest core region of this forming structure. This protocluster is characterized by a high fraction of AGN (~23%). For one of them, AGN1317, we produced two so-called Baldwin, Phillips & Terlevich (BPT) diagrams. The high fraction of AGN and their distribution within the protocluster seem to be consistent with predictions of some theoretical models on AGN growth and feedback. These models are based on galaxy interactions and ram pressure as triggers of AGN activity.

Conclusions. The high fraction of AGN belonging to the protocluster suggests that they were likely triggered at the same time, maybe by the ongoing formation of the protocluster. Observations of AGN in this protocluster and in other distant clusters will help clarifying whether the resulting high fraction of AGN is unusual or typical for such structures at high redshift. Our next step will be analyses of previously acquired high-resolution radio data of the central radio galaxy to derive information on the nature of the radio galaxy and connect it with its cosmic evolution.
Multilevel Diffuser Augmented for Horizontal Axis Wind Turbine
Authors: Qashidi Putra Fariz , Rifai Dani , Suryopratomo Kutut , Budiarto Rachmawan
Published: June 2018

Indonesia is an area with the low and fluctuating wind speed. Therefore, the implementation of the wind turbine to generate electricity become ineffective and economically unprofitable. Diffuser Augmented Wind Turbine (DAWT) is the augmentation technology in wind turbine which could increase wind speed flow that arrives on the turbine blade. The working principle of the diffuser is to create a difference in pressure inside and outside the diffuser. The pressure inside the diffuser is lower than the pressure outside so that the wind will be accelerated into the diffuser and wind speed will dramatically increase at the inlet of the diffuser. This study will be presenting a modified design of diffuser augmented wind turbine (DAWT) by designing multilevel diffuser with additional inlet curvature and flange. This research aims to evaluate the amplification of flow velocity profile around the diffuser that has been engineered. The numerical study is performed using computational fluid dynamic (CFD) to obtain the highest ratio of speed increment. The verification of numerical initial condition is validated by comparing the result of validation with experimental data available in the literature. The result shows that a ratio of increase in speed is 2.08 times higher than conventional wind turbine over 4 m/s inlet velocity. In the equation of a wind power output, the wind speed is proportional to the cubic power of its wind power output. Therefore, the utilization of dual-stage diffuser device in wind turbine would give significant increment on the power output of wind turbine.
Energy Monitoring System for Existing Buildings in Indonesia
Authors: Sesotya Utami Sentagi , Faridah  , Azizi Na’im A. , Kencanawati Erlin , Tanjung M. Akbar , Achmad Balza
Published: June 2018

Current studies conducted by JICA, AMPRI and IFC-World Bank, reported that large commercial buildings in Indonesia are not energy and water efficient. One of the cause is the lack of regulation. Meanwhile, effective regulations to reduce energy and water consumption are the concern mostly in a new building to obtain a building permit. This strategy is understandable as retrofitting existing buildings are often more difficult to be implemented, and enforcement is still a major issue in Indonesia. Local governments are currently working on streamlining building permit process as well as developing an online monitoring system for existing buildings. By applying a Building Energy Management System (BEMS) enables to reduce energy consumption up to 15%. An energy monitoring system was designed and installed through this research for Department of Nuclear Engineering and Engineering Physics (DNEEP) building, Faculty of Engineering, Universitas Gadjah Mada. It is a 20 years old two-story building used for educational activities, which consist of classrooms, laboratories, offices and storage spaces. An audit energy was done recently in 2015 where an energy consumption of 261.299,636 kWh/year.m2 was reported. In the existing condition, a power meter is inaccessible and therefore, the only feedback of occupancy behavior in the energy consumption is through the electricity bill. The previous study has shown that building occupants would behave more efficiently if the amount of energy used is notified, and the amount of energy savings are recorded. However, these energy monitoring systems are considered expensive and uniquely tailored for every building. This research aims to design and install a cost effective BEMS based on occupant’s satisfactory assessment of the lighting, acoustics, and air conditioning quality. The data will be used as a decision supporting system (DSS) by building management through the use of a GUI. The design of the interface was based on a survey result from the prospective users. Installed energy monitoring system uses a current sensor with an accuracy of 98% and a precision of 0.04 A while the voltage sensor with an accuracy of 98% and a precision of 0.58 V. The performance testing shows that the number of web clients influences delay of data transmission. The result of the survey shows that GUI is categorized as fair in design without a significant difference between the perceptions of users with and without survey supervision.
Development of Biobriquette from Nutmeg Seed Shells
Authors: Idris Rukmana , Tawiequrrohman Yuliansyah Ahmad , Purwono Suryo
Published: June 2018

Nutmeg seed shell is one of biomass resources in Indonesia that has not been widely used. Nutmeg (Myristicafragans) in North Maluku province, especially in Tidore Island, is one of the largest incomes in the plantation sector. Nutmeg consists of pulp, mace, shell and seeds. Not all parts of nutmeg can be utilized or to be sold. The most widely used are the seed, mace (red salute that bind shell beans) and meat of nutmeg, while some parts have not been used optimally such as the shells. The abundance of nutmeg seed shells has only been discarded and not optimally utilized, therefore it needs to do a research on the utilization of nutmeg seed shells into briquettes that have good quality, which can be used as energy source and improve economic value. One fo the solutions is by converting it into bio briquette through pyrolysis process. Pyrolysis is chemical decomposition of organic materials through a process of heating without oxygen or under conditions of a little air, causing the release of volatiles and char formation. If the material contains water, at the beginning of heating, the free water will come out first at a temperature of about 120oC. Up to 170oC, volatile organic substances from hydrolysis will be released out. The conditions affect pyrolysis processes are temperature, heating time and particle size. The higher the temperature the higher the rate of decomposition.
Al-alginate as acid catalyst for FAME synthesis using electrolysis process
Authors: Syah Putra Rudy , Rahma Tasyrifatur
Published: June 2018

A novel solid acid catalyst, which was prepared from sodium alginate and aluminum chlorides and characterized by SEM-EDS, XRD and FT-IR spectrometry. The catalyst was used for the synthesis of fatty acid methyl ester (FAME) via (trans)esterification reaction using electrolysis process. Purity and FAME components of biodiesel were measured by GC-MS. The results showed that the aluminum-alginate prepared in a cheap and easy way exhibited high catalytic activity. FAME conversion from used-cooking oil was obtained by 93.82% in the presence of 10 wt.% of catalyst dosage upon refluxing for 4 h of methanol and oil in a molar ratio of 6:1.
Design and Implementation Buck Converter for 540WP Solar Charger Using Fuzzy Logic Control
Authors: Sutedjo  , Asrarul Qudsi Ony , Ardianto Andi , Septi Yanaratri Diah , Suhariningsih  , Darwis Moch.
Published: June 2018

This paper presents the details of design and implementation of DC-DC Buck converter as solar charger. This converter is designed for charging a battery with a capacity of 100 Ah (Ampere Hours) which has a charging voltage of 27.4 volts. The constant voltage method is selected on battery charging with the specified set point. To ensure the charging voltage is always on the set point, the duty cycle control of buck converter is set using Fuzzy Logic Control (FLC). The design implementation has been tested on PV (photovoltaic) with 540WP capacity. Based on the test results, this method is quite well implemented on the problem charger
Activity Based Smart Lighting Control For Energy Efficient Building By Neural Network Model
Authors: Hidayat Ivan , Faridah  , Sesotya Utami Sentagi
Published: June 2018

The goal of this research is to attain a smart control algorithm that can be used in a lighting system based on the activities of a building's occupants, using the neutral network model method. The study case of this research is the activities inside the Asrama Mahasiswa Kinanti UGM building. Control algorithm was built based on qualitative data from the occupants of the building, which were more or less the daily activities of the occupants. The results of the qualitative data will be essential in choosing a sensor and its placement. Several scenarios of activities represented by the combination of sensors' outputs are used as the control system input. The optimum illumination of the lighting system for these scenarios was produced through simulation using DIALux. An artificial neural network model was then developed and used as the smart control algorithm. Input for the neural network is the combination of sensor output and illumination output for each scenarios, given the simulation results. Based on the qualitative data acquired through a survey of the occupants' activities, the design of the lighting control system requires a system that uses occupancy sensors, weight sensors, photoelectric sensors, and photo sensors. The various positions and activities being done by the occupants are represented by the sensors output. A manual remote will be used to adjust the sensors regarding details that cannot be specifically detected. Ongoing specific activities inside the inhabited room gives off a system output. This scenario portrays the lighting conditions of the room, which includes the number of lights that are turned on or turned off. A smart control algorithm was developed using the backpropagation neural network model with 10 neuron inputs, the first hidden layer with 20 neurons, second hidden layer with 20 neurons, whilst the output layer has 5 neurons. The activated function for the first hidden layer is tan-sigmoid, for the second hidden layer is log-sigmoid, and the output layer is using pure linear. The training function uses trainlm. The MSE system's value is 2.72 x 10-8 with a larger R total value, which is 0.99892.
Performance Test of VHF-HF-based Emergency Data Communication System between the Sardjito Hospital and District Hospital in the Isolated and Disaster-prone Areas
Authors: Hawibowo Singgih , Sunarno  , Motivanisman Waruwu Memory , Fahim Luckyarno Yakub , Wijaya Rony , Kristiyana Samuel
Published: June 2018

The topography of Gunungkidul area in the Province of Yogyakarta, Indonesia, consisting of hills and limestone mountains. It becomes the potential factor of landslide occurrences. Especially in the rainy season, the soils in the hills become softer and it increases the possibility to cause a landslide. This condition has became the concern of many people, especially the residents who live in the landslide-prone area. This topography is also one of the factors for health centre in a certain area becomes isolated due to the inability of telecommunication signal services from the provider to reach that area, which is called a blank area. That situation makes an inability to contact the nearest district hospital to ask for support in an emergency case. This research focuses on the performance test of the emergency data communication system by using several types of data. The system uses Very High Frequency (VHF) 144 MHz and High Frequency (HF) 7.08 MHz as the data carrier and a software to interpret the text and image to be modulated onto the data carrier. That system is called a virtual hospital, means that even though the health center is located in a blank area, but specialists from the Sardjito Hospital can still deliver advices to support the health center in maintaining the medical service quality by using the VHF-HF-based emergency data communication system. Based on the results of the system's performance test between the Wonosari Gunungkidul District Hospital and the Sardjito Hospital with the distance of 40 km, the receiving quality of the data transmission for text and image are 95% and 55.33%, respectively.
Prognostic Methods on Accelerator’s Anode Voltage Regulator
Authors: Christian Robby , Achmad Balza , Gook Kang Hyun
Published: June 2018

This study investigated an adaptive control, fault diagnostics and prognostics of the anode voltage regulator system at an ion implantation accelerator. The system was modeled as a 4th order AutoRegressive with eXogenous (ARX) model, controlled by a Fuzzy Logic Controller (FLC). This model was then used as a basis for constructing and updating a fault diagnosis module and a failure prognostics module. To maintain the system’s performance, the controller’s response was continuously re-adjusted through an optimization scheme. A Failure Mode and Effect Analysis (FMEA) was conducted resulting on five failure modes of the regulator system. Fault data were generated in MATLAB simulation to train a random forest fault classification engine. The optimal random forest classifier was 20 decision trees with a fault diagnostics accuracy of 98.06%. A Hidden Markov Model (HMM) was constructed as the system’s fault progression model based on the interaction between environmental conditions and controller actions. The particle filter and Bayesian inference methods were then employed to continuously update the HMM and predict the system’s Remaining Useful Lifetime (RUL). The proposed methodology was able to integrate an adaptive fuzzy logic control, prognosis and failure diagnosis altogether allowing a continual satisfactory performance of the voltage regulator system throughout its lifetime.
Study of Supervisory Control Implementation in A Small Scale Variable Speed Wind Turbine
Authors: Indriawati Katherin , Musyafa Ali , Widjiantoro Bambang L. , Milatul Ummah Anna
Published: June 2018

In relation to improve wind energy production, efforts to increase the extraction of wind energy should be done when there is a decrease in wind power. The decline occurs when there is a change in wind speed. At low wind speed operating range, such as in Indonesia, the controller optimizes power extraction through wind turbine rotor regulation following optimal rotor speed. This study proposed the use of the PI control system as an intelligent control system to solve nonlinearity problem and the setpoint adjustment mechanism to get at the problem of the uncontrolled stochastic driving force input. The PI control is called as a regulatory control while setpoint adjustment is known as one mechanism in supervisory level. Thus, that control system is called as the supervisory control. This control had a task to maximize output power of a wind turbine. The technique was applied to a small scale horizontal axis wind turbine operating in wind speed range of 3-11 m/s. The applied optimization algorithm generated an optimum set-point simultaneously when there was a change of wind speed.
The α-decay of the Hoyle state in 12C: a new high-precision investigation
Authors: Dell‘Aquila D. , Lombardo I. , Verde G. , Vigilante M. , Acosta L. , Agodi C. , Cappuzzello F. , Carbone D. , Cavallaro M. , Cherubini S. , Cvetinovic A. , D‘Agata G. , Francalanza L. , Guardo G.L. , Gulino M. , Indelicato I. , La Cognata M. , Lamia L. , Ordine A. , Pizzone R.G. , Puglia S.M.R. , Rapisarda G.G. , Romano S. , Santagati G. , Spartà R. , Spadaccini G. , Spitaleri C. , Tumino A.
Published: June 2018

The αdecay path of the Hoyle state in 12C (Ex = 7:654MeV) represents one ofthe most challenging questions of modern nuclear physics. Its knowledge can help in theunderstanding of cluster configurations in light nuclei and the possible existence of Bose-Einstein condensates in nuclei. In stars, it is involved in the so-called 3αprocess, wherethe 12C nucleosynthesis occurs. We studied the 14N(d; α2)12C(7:654) reaction at 10:5MeVincident energy to probe its direct decay component. We found, with a precision higherof a factor 5 than any other previous experiment, an almost total absence of direct decaysby-passing the ground state of 8Be. From our analysis, a new upper limit of such decayis found at 0:043% (95% C.L.). Astrophysical 3α process reaction rate calculations haveto be accordingly revised.
RIB production and related experiments at EXOTIC
Authors: Mazzocco Marco
Published: June 2018

Radioactive nuclei have a very deep relevance in many astrophysical scenarios, from the Big Bang nucleo-synthesis to supernova explosions. Several Nuclear Physics laboratories around the world have been constructing large-scale facilities for the production of Radioactive Ion Beams (RIBs). The main production techniques, i.e. In-Flight and Isotope Separation On Line, which will be reviewed in this contribution. In particular, we will concentrate on the production of light weakly-bound RIBs at the facility EXOTIC, located at INFN-LNL (Italy) and we will describe the most recent experiments.
Gas detectors for nuclear physics experiments
Authors: Pierroutsakou Dimitra
Published: June 2018

In this lecture I will present the operation principle and the different kinds of gas detecting systems for charged particles employed in high-energy and low-energy physics environments, with particular focus on the requirements of nuclear physics experiments with low-energy Radioactive Ion Beams (RIBs). I will show in more details an example of gas detector used at the RIB in-flight facility EXOTIC, for the ion beam tracking and for time of flight measurements. Finally, I will discuss the use of an active target in nuclear physics experiments with RIBs together with some key improvements
of first generation devices required for facing the challenges of more intense RIBs.
The Trojan Horse Method in Nuclear Astrophysics
Authors: Tumino Aurora , Spitaleri Claudio , Cherubini Silvio , D’Agata Giuseppe , Giovanni Luca Guardo , Gulino Marisa , Indelicato Iolanda , La Cognata Marco , Lamia Livio , Rosario Gianluca Pizzone , Giuseppe Gabriele Rapisarda , Romano Stefano , Maria Letizia Sergi , Spartá Roberta
Published: June 2018

The Trojan Horse Method (THM) represents the indirect way to measure reactions between charged particles at astrophysical energies. This is done by measuring the quasi free cross section of a suitable three body process. The basic features of the THM will be presented together with some applications to demonstrate its practical use.
26Mg target for nuclear astrophysics measurements
Authors: Siváček I. , Mrázek J. , Kroha V. , Burjan V. , Glagolev V. , Piskoř Š. , Spitaleri C. , Pizzone R.G. , La Cognata M. , D’Agata G. , Tumino A. , Lamia L. , Spartá R. , Rapisard G.G. , Romano S.
Published: June 2018

Two nuclear reactions of astrophysical interest, 26Mg(3He,d)27Al and 26Mg(d,p)27Mg, were measured for extraction of the Asymptotic Normalization Coefficients. Investigation of the target composition is presented, as well as the effects that showed up during analysis of the in-beam data obtained on CANAM accelerators in the Nuclear Physics Institute of the Czech Academy of Sciences (NPI CAS).
7Be and 8B reaction dynamics at Coulomb barrier energies
Authors: Strano E. , Mazzocco M. , Boiano A. , Boiano C. , La Commara M. , Manea C. , Parascandolo C. , Pierroutsakou D. , Signorini C. , Torresi D. , Yamaguchi H. , Kahl D. , Acosta L. , Di Meo P. , Fernandez-Garcia J.P. , Glodariu T. , Grebosz J. , Guglielmetti A. , Imai N. , Hirayama Y. , Ishiyama H. , Iwasa N. , Jeong S.C. , Jia H.M. , Keeley N. , Kim Y.H. , Kimura S. , Kubono S. , Lay J.A. , Lin C.J. , Marquinez-Duran G. , Marte I. , Miyatake H. , Mukai M. , Nakao T. , Nicoletto M. , Pakou A. , Rusek K. , Sakaguchi Y. , Sanchez-Benitez A.M. , Sava T. , Sgouros O. , Stefanini C. , Soramel F. , Soukeras V. , Stiliaris E. , Stroe L. , Teranishi T. , Toniolo N. , Wakabayashi Y. , Watanabe Y.X. , Yang L. , Yang Y.Y.
Published: June 2018

We investigated the reaction dynamics induced by the 7Be,8B+208Pb collisions at energies around the Coulomb barrier. Charged particles originated by both the col- lisions were detected by means of 6 ΔE-Eres telescopes of a newly developed detector array. Experimental data were analysed within the framework of the Optical Model and the total reaction cross-sections were compared together and with the 6,7Li+208Pb colli-sion data. According to the preliminary results, 7Be nucleus reactivity is rather similar to the 7Li one whereas the 8B+208Pb total reaction cross section appears to be much larger than those measured for reactions induced by the other weakly-bound projectiles on the same target.
A comparison of uncertainty propagation techniques using NDaST: full, half or zero Monte Carlo?
Authors: Dyrda James , Hill Ian , Fiorito Luca , Cabellos Oscar , Soppera Nicolas
Published: June 2018

Uncertainty propagation to keff using a Total Monte Carlo sampling process is commonly used to solve the issues associated with non-linear dependencies and non-Gaussian nuclear parameter distributions. We suggest that in general, keff sensitivities to nuclear data perturbations are not problematic, and that they remain linear over a large range; the same cannot be said definitively for nuclear data parameters and their impact on final cross-sections and distributions. Instead of running hundreds or thousands of neutronics calculations, we therefore investigate the possibility to take those many cross-section file samples and perform ‘cheap’ sensitivity perturbation calculations. This is efficiently possible with the NEA Nuclear Data Sensitivity Tool (NDaST) and this process we name the half Monte Carlo method (HMM). We demonstrate that this is indeed possible with a test example of JEZEBEL (PMF001) drawn from the ICSBEP handbook, comparing keff directly calculated with SERPENT to those predicted with NDaST. Furthermore, we show that one may retain the normal NDaST benefits; a deeper analysis of the resultant effects in terms of reaction and energy breakdown, without the normal computational burden of Monte Carlo (results within minutes, rather than days). Finally, we assess the rationality of using either full or HMMs, by also using the covariance data to do simple linear 'sandwich formula' type propagation of uncertainty onto the selected benchmarks. This allows us to draw some broad conclusions about the relative merits of selecting a technique with either full, half or zero degree of Monte Carlo simulation
Determination of Nickel in End-Fitting of Spoolable Reinforced Plastic Line Pipe
Authors: Shao Xiaodong
Published: June 2018

Spoolable reinforced plastic line pipe will be widely used in the exploitation of acid gas and oil wells. End-fitting is a mechanical device that forms the transition from the spoolable reinforced plastic line pipe to the connector. It was well known that nickel was an important element in the end-fitting. In this paper, a novel spectrophotometric method was described for determination of nickel in the end-fitting of spoolable reinforced plastic line pipe. The method was based on the color reaction between nickel and dimethylglyoxime, which was favored in an alkaline medium, producing a red compound in the presence of ammonium persulfate as an oxidant. Under the optimum reaction conditions the absorption value was proportional to the concentration of nickel in the range of 0.080~0.50% (R2 = 0.9999), and the relative standard deviation was less than 3.0% (n=5). The proposed method was applied successfully to determine nickel in end-fitting of spoolable reinforced plastic line pipe.
Effect of Co-monomer Styrene on Reactive Compatibilization of PE/Wood-flour Composites
Authors: Li Yuewen , Chen Xinhua
Published: June 2018

Compatibilization between polyethylene(PE) and wood-flour was achieved by means of direct reactive extrusion of PE, wood-flour, maleic anhydride(MAH), co-monomer styrene(St) and dicumyl peroxide. Mechanical properties and heat distortion temperature(HDT) of the PE/wood-flour composites were tested, and impact cracking surfaces of the composites were observed via scanning electron microscope. Effect of St on reactive compatibilization of the composites was evaluated. Experimental results indicated that the anchoring strength of interface in the composites was obviously strengthened after St was added. Mechanical properties and HDT of the composites raised with increase of use level of St on the initial stage, and then gradually descended. When use level of St ran up to 1.5%, mechanical properties and HDT of the composites were best. At this moment, the mole ratio of St and MAH was approximately 1:1.
Analysis on Interfacial Performance of CFRPConcrete with Different Thickness of Adhesive Layer and CFRP Plate
Authors: Guo Qingyong , Zhao Huijian , Chen Lei , Mao Jize , Zhang Wensong
Published: June 2018

The bond behavior of CFRP-concrete interface is the analysis foundation for concrete structures with external strengthening CFRP. In the paper, the influences of the thickness of CFRP plate and adhesive layer on interfacial adhesive properties are investigated through the finite element program. The influence rules of the thickness on the interfacial ultimate bearing capacity and the effective bond length are performed. The results show that the thickness of adhesive layer and CFRP plate has a significant effect on the interfacial performance of CFRP-concrete.
Combined Effect of Initial Curing Temperature and Crack Width on Chloride Penetration in Reinforced Concrete Beams
Authors: Elkedrouci Lotfi , Diao Bo , Pang Sen , Li Yi
Published: June 2018

Reinforced concrete (RC) structures are gradually being degraded all over the world, largely due to corrosion of the embedded steel bars caused by an attack of chloride penetration. Initial curing would be regarded as one factor influencing chloride diffusion in concrete in combination with cover cracking that is also of great attention for reinforced structures. In this study, a non-steady state diffusion test of chloride ion involving RC beam specimens with a water-to-cement ratio of 0.5, initial curing temperatures of 5°C or 20°C and three types of crack widths ranging from 0 to 0.2mm was performed. Chloride content at 5°C or was determined. The results show that the higher chloride content was obtained in condition of crack width large than 0.1mm with low initial curing temperature and there are no obvious differences in chloride content when the crack width was not larger than 0.1mm.
Performance on Water Stability of Cement-Foamed Asphalt Cold Recycled Mixture
Authors: Li Junxiao , Fu Wei , Zang Hechao
Published: June 2018

Through designing the mixture proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, it shows that the addition of cement can obviously improve foamed asphalt mixture’s water stability and the best cement admixture is between 1% ~ 2%; Using digital imaging microscope and SEM technology, the mechanism of increasing on the intensity of foamed asphalt mixture resulted by adding cement was analyzed. It revealed that the cement hydration products contained in the foamed asphalt mixture hydrolyzed into space mesh structure and wrapped up the aggregate particle, this is the main reason that the cement can enhance the mixture’s intensity as well as the water stability. This research provides reference for cement admixture’s formulation in the designing of foamed asphalt cold in-place recycled mixture.
A Measuring Method of Gravel’s Coefficient of Restitution and Discussion
Authors: Chen Yanhui , Zhang Xinjie , Wang Bin
Published: June 2018

In this paper, a simple method for measuring the recovery coefficient of gravel was proposed by the definition of the coefficient of restitution and the principle of kinematics. The recovery coefficient between gravel and slate was obtained by the experiment; meanwhile the reason of error was analyzed and discussed. Finally, the experimental results were compared with the simulation data of the EDEM software. It was concluded that the data were more appropriate when the gravel particles were smaller.
Failure Analysis and Safety Protection of a Certain Type of Wire Ropes under High-Speed Impact Loads
Authors: Ren Zhiqian , Lu Zhiqiang , Yu Qiong , Jiang Yun
Published: June 2018

As the key bearing components in engineering projects, wire ropes often suffer from high-speed impact loads in service. In the majority of applications, wire ropes are subjected to the loads with the following characteristics: alternating impact loads, short-time overload, and small movements among adjacent spiral strands. Typical failure modes of wire ropes include fracture, wear, corrosion, geometric failure and thermal failure. In this work, the corresponding failure mechanisms were analyzed. For a certain type of wire ropes, the fracture morphology, surface quality, microstructure and internal defects of steel wires were analyzed, and failure causes were discussed. Accordingly, the precautions in relation to the safe use of wire ropes were proposed.
Anti-carburizing Coating for Resin Sand Casting of Low Carbon Steel Based on Composite Silicate Powder Containing Zirconium
Authors: Zhan Chunyi , Feng Shengshan , Xie Shuzhong , Liu Chunjing , Gao Yunhua , Liang Jiahao
Published: June 2018

This paper studied the structure and properties of anticarburizing coating based on composite silicate powder containing zirconium by X-ray diffraction analyzer, thermal expansion tester, digital microscope and other equipment. It is introduced that the application example of the coating in the resin-sand casting of ZG1Cr18Ni9Ti stainless steel impeller. The anti-carburizing effect of the coating on the surface layer of the cast is studied by using direct reading spectrometer and spectrum analyzer. The change of the micro-structure of the coating after casting and cooling is observed by scanning electron microscope. The analysis of anti-carburizing mechanism of the coating is presented. The results indicate that the coating possesses excellent suspension property, brush ability, permeability, levelling property and crackresistance. The coating exhibits high strength and low gas evolution. Most of the coating could be automatically stripped off flakily when the casting was shaken out. The casting possesses excellent surface finish and antimetal penetration effect. The carburizing layer thickness of the stainless steel impeller casting with respect to allowable upper limit of carbon content is about 1mm and maximum carburizing rate is 23.6%. The anticarburizing effect of casting surface is greatly improved than that of zircon powder coating whose maximum carburizing rate is 67.9% and the carburizing layer thickness with respect to allowable upper limit of carbon content is greater than 2mm. The composite silicate powder containing zirconium coating substantially reduces the zircon powder which is expensive and radioactive and mainly dependent on imports. The coating can be used instead of pure zircon powder coating to effectively prevent metal-penetration and carburizing of resin-sand-casting surface of low carbon steel, significantly improve the foundry production environment and reduce the production costs.
Comparative Study on Wettability of Typical Plant Leaves and Biomimetic Preparation of Superhydrophobic Surface of Aluminum Alloy
Authors: Sun Yanhong , Gao Xinxin , Li Jinnong , Chen Ying
Published: June 2018

The water droplets spread observation, contact angle measurement and SEM analysis, data processing and other means, comparative study of different states of the lotus leaf, rice leaf and nasturtium leaf are carried out. The results show that their surface contact angle of three kinds of plant leaves are all over 140°, they have hydrophobic or superhydrophobic properties; dehydration degree of leaves has little effect on the wettability, will not change its hydrophobic property; the same point of wettability is that they have micro nano composite microstructure. The difference is, the wettability of the lotus and nasturtium is isotropic, while the rice is anisotropic, that is, in a direction parallel to the edge of hydrophobic than perpendicular to the blade edge enhancement. Based on the theoretical research, the hydrophobic surface is copied to the surface of aluminum alloy. The superhydrophobic surface of aluminum alloy matrix was successfully prepared by chemical etching combined with surface fluorination. The super hydrophobic aluminum alloy surface has micron-nano scale double roughness structure; its surface contact angle reached 156°.