bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on high robustness and fast dynamic response synchronous rectifier buck converter
Authors: Gu Yu , Zhang Donglai , Zhang Xiaofeng
Published: January 2018

Here, a novel control strategy combined by constant‐frequency V2 control and H∞ robust control is proposed and tested in a buck converter. The control strategy not only demonstrates the fast transient response of ordinary V2 control, but also shows strong robustness with different input conditions. The main drawbacks of V2 control, such as high interference susceptibility and low input perturbation stability margin, can be improved by introducing H∞ robust strategy into the controller design. During the analysis and design process, the original controlled system based on the V2 control is modelled at first, then the H∞ weighting functions are calculated according to the small‐signal analysis of V2 controlled buck converter. After that, the H∞ robust compensator parameters based on constant‐frequency V2 control are calculated. Finally, a buck converter controlled by the proposed control strategy is built and tested, with 48 V input voltage, 12 V output voltage, and 120 W output power. The experimental results demonstrate the effectiveness of the converter with the proposed control, which also proves the proposed method has great potential for high robustness and fast dynamic response applications.
Adsorption of toluene vapours on micro–meso hierarchical porous carbon
Authors: Yan Xi , Liu Fang , Mu Guiqin , Zhou Zhiguo , Xie Yan , Li Long , Yang Yangyang , Wang Xinzhe
Published: January 2018

This work reports the synthesis of micro–meso hierarchical porous carbons prepared with sucrose as a carbon source. With properties characterised, dynamic adsorption performances of toluene on carbons were investigated at various initial concentrations. Results showed that adsorption capacities as high as 687.60 mg/g toluene/1 cm modified carbon can be achieved. Thus, large surface area, large volume of narrow microporosity and proper average pore size are the desired parameters to achieve strong toluene adsorption capacities. Moderate amounts of surface oxygen groups can also improve the adsorbents performance.
Suppression of ambipolar conduction and investigation of RF performance characteristics of gate‐drain underlap SiGe Schottky barrier field effect transistor
Authors: Kumar Prashanth , Bhowmick Brinda
Published: January 2018

In this work, a hetero structure gate‐drain underlap (UL) Schottky barrier (SB) Field Effect Transistor (FET) is explored to achieve high device performance compared with high‐k and low‐k hetero structure SB FET (HSBFET). The effects of gate drain UL junction on the performances of UL‐HSBFETs have been studied in terms of electrical characteristics including on‐current (Ion), subthreshold swing, Ion/Ioff ratio, ambipolar conduction, and Ioff current. The low on‐state current of silicon‐based SB FETs can be enhanced by introducing the low bandgap silicon germanium material. Gate‐drain UL and silicon germanium channel with low barrier height provides less tunnelling width which enhances the carrier injection at on‐state compared with low‐k and high‐k HSBFET. Further, the proposed UL‐HSBFET suppresses the ambipolar conduction due to holes. In contrast to conventional high‐k and low‐k HSBFET that suffers from severe ambipolar conduction, the UL‐HSBFET device reduces the conduction at drain‐channel junction with increasing the UL length to 5, 10, 15, and 20 nm. This provides better radio frequency performances with improved carrier capability of the proposed device. Therefore, UL‐HSBFET device can be one of the best possible competitor for high‐frequency application. The performance comparison of all the devices is carried out using Technology Computer‐Aided Design (TCAD) simulator.
K2-141 b
Authors: Barragán O. , Gandolfi D. , Dai F. , Livingston J. , Persson C. M. , Hirano T. , Narita N. , Csizmadia Sz. , Winn J. N. , Nespral D. , Prieto-Arranz J. , Smith A. M. S. , Nowak G. , Albrecht S. , Antoniciello G. , Bo Justesen A. , Cabrera J. , Cochran W. D. , Deeg H. , Eigmuller Ph. , Endl M. , Erikson A. , Fridlund M. , Fukui A. , Grziwa S. , Guenther E. , Hatzes A. P. , Hidalgo D. , Johnson M. C. , Korth J. , Palle E. , Patzold M. , Rauer H. , Tanaka Y. , Van Eylen V.
Published: January 2018

We report on the discovery of K2-141 b (EPIC 246393474 b), an ultra-short-period super-Earth on a 6.7 h orbit transiting an active K7 V star based on data fromK2campaign 12. We confirmed the planet’s existence and measured its mass with a series of follow-up observations: seeing-limited MuSCAT imaging, NESSI high-resolution speckle observations, and FIES and HARPS high-precision radial-velocity monitoring. K2-141 b has a mass of 5.31 ± 0.46M⊕and radius of 1.54−0.09+0.10R⊕, yielding a mean density of 8.00−1.45+1.83g cm−3and suggesting a rocky-iron composition. Models indicate that iron cannot exceed ~70% of the total mass. With an orbital period of only 6.7 h, K2-141 b is the shortest-period planet known to date with a precisely determined mass.
Theoretical performance of serrated external occulters for solar coronagraphy
Authors: Rougeot R. , Aime C.
Published: January 2018

Context. This study is made in the context of the future solar coronagraph ASPIICS of the ESA formation-flying mission Proba-3.

Aims. In the context of solar coronagraphy, we provide a comparative study of the theoretical performance of serrated (or toothed) external occulters by varying the number and size of the teeth, which we compare to the sharp-edged and apodized disks. The tooth height is small (a few centimeters), to avoid hindering the observation of the solar corona near the limb. We first analyze the diffraction pattern produced by such occulters. In a second step, we compute the umbra profile by integration over the Sun.

Methods. We explored a few methods to compute the diffraction pattern. Two of them were implemented. The first is based on 2D fast Fourier transformation (FFT) routines and a multiplication by the Fresnel filter of the form exp(−iπλzu2). Simple rules were derived and discussed to set the sampling conditions. The Maggi–Rubinowicz representation is then proposed as an alternative method, and is proven to be very efficient for this study.

Results. Serrated occulters tend to create a two-level intensity pattern, the inner being the darker, which perfectly matches a previously reported geometrical prediction. The diffraction in this central region is lower by two to four orders of magnitude when compared to the sharp-edged disk. The achieved umbra level at the center ranges from 10−4 to below 10−7, depending on the geometry of the teeth.

Conclusions. Our study shows that serrated occulters can achieve a high rejection and can almost reach the performance of the apodized disk when very many teeth are used. We prove that shaped occulters must be preferred to simple disks in solar and stellar coronagraphy.
Decreased stock entering the Belgian Meuse is associated with the loss of colonisation behaviour in yellow-phase European eels
Authors: Nzau Matondo Billy , Ovidio Michaël
Published: January 2018

The upstream migratory behaviour of yellow-phase European eels was investigated in regulated inland rivers (>320 km upstream the sea), where the stock is in drastic decline. From 2010 to 2015, eels entering the Belgian Meuse River (n = 1357; total length, 231–755 mm) were caught in fish passes, tagged with a pit-tag and released. Their upstream movements were tracked during the next six consecutive years, using three detection stations installed in vertical-slot fish passes of the Meuse and its Ourthe tributary. Among the 1357 eels tagged, 27.6% (n = 374 individuals) were detected at one or more of the three upstream detection stations. Only 6.6% (n = 89) of tagged eels were detected at the two subsequent stations. In this last group, most of the detected eels continued to move upstream through the Meuse rather than leaving it for the Ourthe. Water temperature >13 °C, river flow 24–226 m3/s, dark time 00:00–05:00 h and the spring–summer seasons were the most important cues for upstream migration. Temperatures and flows at detection did not differ between size classes of ascending eels, while the detection period was earlier and daily speed was faster in large (>450 mm) eels. However, small (≤300 mm) eels moved further upstream at slow speeds because they alternated between short periods of movement and long stationary periods. This behaviour suggests the existence of a few nomad individuals and probably more home range dwellers in the entering population. Small eels were better suited to colonise upper rivers.
Particularités du collage aux dents qui ont subi un éclaircissement
Authors: AGUIR Najet , JEMÂA Mayada , JALOULI Emna , KHATTECH MB , BHOURI Lotfi
Published: January 2018

L’action oxydative du peroxyde d’hydrogène
est responsable de la diminution de la force
d’adhésion immédiatement après
un éclaircissement. L’oxygène résiduel
interfère avec la polymérisation et la diffusion
de l’adhésif dans les anfractuosités dentaires.
Pour le faire échapper, il faut reporter
les procédures de collage de deux semaines
en cas d’éclaircissement interne. Après
un éclaircissement externe, l’emploi des agents
anti-oxydatifs, tel que l’ascorbate de sodium,
permet d’éviter la diminution de la force
d’adhésion, permettant ainsi le collage
immédiatement après l’éclaircissement.

L’éclaircissement à concentration élevée
peut modifier les propriétés mécaniques
et esthétiques des restaurations adhésives
préexistantes, d’où la nécessité de les remplacer
après un traitement d’éclaircissement
afin d’optimiser le résultat esthétique final.
Fracture coronaire avec exposition pulpaire d’une incisive permanente maxillaire immature : à propos d’un cas
Authors: BACCOUCHE Fatma Masmoudi , SEBAI Anouar , BACCOUCHE Zied , MAATOUK Fethi
Published: January 2018

Les traumatismes dentaires sont très
fréquents chez les enfants et arrivent souvent
à un âge où les dents permanentes sont
encore immatures. La nécrose pulpaire d’une
dent permanente immature provoque l’arrêt
de son édification radiculaire et l’apposition
de dentine sur les parois radiculaires. Cette
situation rend difficile l’obtention d’une
obturation canalaire conventionnelle étanche.
La démarche thérapeutique dépendra
du degré de l’immaturité de la dent mais
aussi de l’importance du délabrement
coronaire. L’objectif de cet article est
de présenter la gestion de la nécrose d’une
incisive permanente maxillaire immature
suite à une fracture coronaire pénétrante
avec délabrement important.
Traitement orthopédique des classes III par stimulation de la croissance du maxillaire
Authors: BEN YOUNES-UZAN Carine
Published: January 2018

Le manque de développement du maxillaire
génère un hyperdéveloppement mandibulaire
dans les 3 plans de l’espace.

Cette insuffisance de croissance est tout à
fait rattrapable et majorable et d’autant plus
que l’enfant est jeune avec de la croissance
à venir.

L’utilisation d’appareillages fonctionnels permet
aux dents maxillaires de recevoir les stimuli
masticatoires, et au maxillaire de se développer
dans les 3 plans de l’espace en même temps
que la mandibule se repositionne.
Implementation of BIM-technologies in the educational program of the architectural university
Authors: Krivonogov Alexandr , Zakharova Galina , Kruglikov Sergey , Plotnikov Sergey
Published: January 2018

BIM-technologies are the dynamically developing trend in a world construction practice. In conditions of a lack of qualified specialists and lack of appropriate educational standards, we offer our practice-oriented methodology for teaching BIM (Building Information Modeling), which is based on the use of new information technologies. Also some projects implemented in BIM and GreenBIM technologies at the Applied Informatics Department are presented.
The role of managing knowledge and information in BIM implementation processes in the Czech Republic
Authors: Nývlt Vladimír
Published: January 2018

Czech construction sector is at the initial stages of implementing and assessing Building Information Management (BIM) on pilot projects. Object modeling developed over the last 20 years is seemed as a stable ground for many professionals. 3D data models are basis for further concepts associated with BIM, helping to support Co-ordinated Project Information (CPI) and Integrated Project Delivery (IPD). This paper presents the role of managing knowledge, information and critical success factors (CSF) associated with BIM implementation within the construction industry in the Czech Republic. Determining the CSF in the context of BIM maturity levels should support BIM implementation processes within the construction industry and also within the associated bodies (education, government, technology).
System description of the defect creation and elimination in the buildings
Authors: Vytlačil Dalibor
Published: January 2018

The paper deals with the dynamics of the system of defects creation in the buildings and also with the possibilities of the defects elimination. The problem is described by the dynamic model that includes key elements influencing the system behaviour. The model is based on the system dynamics method that uses the stock elements and the flow elements which change the stock element values. In the described problem the main stock is the number of the equipment defects. This parameter can be increased by the flow element that depends on the time of using and the load. For the defect elimination are two possibilities: the planned maintenance and the repair of broken parts. Other elements are number of workers available for the elimination of defects and the running cost depending on the maintenance effort. The case of the main system parameters calculation is presented. The model can be used for understanding the importance of the maintenance in the field of facility management.
Cracked reinforced concrete walls of chimneys, silos and cooling towers as result of using formworks
Authors: Maj Marek , Ubysz Andrzej
Published: January 2018

There are presented in this paper some problems connected with reinforced concrete shell objects operation in the aggressive environment and built in method of formworks. Reinforced concrete chimneys, cooling towers, silos and other shells were built for decades. Durability of cracked shells are one of the most important parameters during process of designing, construction and exploitation of shells. Some reasons of appearance of horizontal and vertical cracks as temperature, pressure of stored material, live loads e.g. dynamic character of wind, moisture, influence of construction joints, thermal insulation, chemistry active environmental etc. reduce the carrying capacity of the walls. Formworks, as is occurred recently, are the reason for technological joints with leaking connection, imperfections of flexible formworks slabs and as result can initiate cracks. Cracked surface of this constructions causes decreasing capacity and lower the state of reliability. Horizontal, vertical cracks can caused corrosion of concrete and steel bars, decreasing stiffness of contraction, increasing of deflection and carbonation of concrete cover. Local and global imperfactions of concrete shells are increasing according to greater number of cracks...
Failure of pillar of sports and entertainment hall structure
Authors: Trapko Tomasz , Musiał Michał , Ubysz Andrzej
Published: January 2018

This paper deals with the failure of one of the sports and entertainment halls in Poland. The facility was built in the years 1977-85. Its main load-bearing members were three-hinged double-sloped frames with a total span of 45 m. The main girders of the frames were made of glued-laminated timber. The girders rest on reinforced concrete pillars. Because of the considerable expansion forces the facility was founded on concrete padstones. In the summer of 2016 one of the reinforced concrete pillars was found to have failed. It was established that the failure condition was mainly due to construction errors. A way of strengthening all the pillars with additional RC members was proposed.
Complex method of defects diagnostics in underground structures
Authors: Beskopylny Alexey , Lyapin Alexander , Kadomtsev Maxim , Veremeenko Andrey
Published: January 2018

The article presents a comprehensive method for diagnosing underground structures using the example of an underground pedestrian crossing located in Rostov-on-Don. The problem of assessing the condition of buildings and structures is very relevant at all stages of the life cycle. There is a special need for continuous monitoring of bearing structures for many buildings with critical applications especially if reliability of which determines the life and health of people. This work considered complex method included geodetic research, geological study of the state of sub-soil, analysis of state of steel and reinforced concrete structures, vibro diagnostics of load-bearing structures under dynamic technogenic impacts and an assessment of the mechanical characteristics of steel and reinforced concrete structures in order to develop a conclusion on the overall state of the transition and the possibility of its further operation. Analysis of the response from arbitrary non-stationary effects on structural elements is carried out on the base of the calculated spectrum of reference impacts.
Interior surface materials as sources of indoor hygiene defects
Authors: Juhasova Senitkova Ingrid
Published: January 2018

The building design and material selection has to respect the environmental requirements of indoor air quality and indoor hygiene parameters. As the first stage of building design is the most important for final indoor air quality more and more by clear constructional architecture the benefit of environmental safety, good indoor air quality for health and productivity are dominant. Nowadays the interior surface materials have received greatest attention as sources of indoor air pollution. The major pollutants in indoor air are volatile organic compounds emitted from materials and building products. Volatile organic compounds, or VOCs, are among the most complex and troubling indoor air pollutants. Manufactured and synthesized products often release large quantities of VOCs, some of the compounds they release, such as benzene, styrene, formaldehyde, and toluene, may be irritating, toxic, or even carcinogenic. VOCs emitted can become attached to other surfaces in the space, especially fabrics, and then be re-emitted over time. The impact of interior surface materials on air quality and indoor hygiene is discussed within the paper. The building design concerning to heath of occupants and hygienic performance regime can be realized only by interdisciplinary team of professionals respecting the environmental building and indoor design.
Design without thermal bridges
Authors: Maltseva Irina , Elokhov Aleksandr , Tkachuk Konstantin , Maltceva Kseniia
Published: January 2018

The main focus of the article is on the quality design and implementation of the thermal insulation of buildings. Shells of buildings consist not only of conventional structures (wall, roof, ceiling), but also of edges, corners, joints and places of disruption of the outer thermal insulation shell integrity (due to through passage of pipelines, ventilation ducts and etc.). In all these places, heat losses are generally increased in comparison with conventional surfaces. Some of them are easily taken into account by calculation, using a special method proposed by the authors. Other thermal bridges due to unfavorable structural details can be avoided by observing the rules and recommendations that are classified and discussed in detail in this article.
Environmentally safe system for treatment of bio corrosion of ETICS
Authors: Minarovičová Katarína , Dlhý Dušan
Published: January 2018

Effects of microorganisms on building facades are responsible for aesthetic, bio-geophysical and biogeochemical deterioration. The process of cleaning of contaminated facades involves the removal and eradication of micro flora on the surface of insulation using chemical products, killing cells and eliminating all living mass, including organic ingredients. The removal of bio corrosion coating from ETICS structure by means of chemical and preservative substances (biocides) is currently the only effective and most used technology. Uncontrolled leaching of the used biocides is unacceptable. Meantime, new technology for environmentally safe maintenance of ETICS is needed. Scientists have been working on replacement the biocides currently used in facades treatment with eco-friendly biocides that have no negative effects on the environment or human beings. While the eco- treatment will be available, safe dewatering of chemicals being leached from the surface of the facade could be provided by e.g. special drain systems adjusted to the building type, use and age. The paper gives an overview of the problem in context of Slovakia and examples of leaching systems designed for new and renovated buildings.
Modern wood windows now and trends after the year 2020
Authors: Palko Milan , Palková Adela , Buday Peter
Published: January 2018

The article deals with the issues of wood windows applicable according to the expected requirements after the year 2020. It analyses the potential of the current top windows in regard to modern design, functionality, and building physical properties. By applying progressive material solutions, it is possible to create windows with proportionally variable frame solutions or even with frameless wing construction. The introduction of vacuum glass systems requires the optimization of the profile system of a wooden window. Modern quality glass systems bring the problem of condensation of water vapour on the exterior surface of the glass. Also, a new phenomenon in the emerging trend of energy-saving buildings and despite the use of quality wooden profile systems is the condensation of water vapour that occurs in the functional joint of the profile system of the wooden window. This fact is increasingly leading to mold growth in functional joints, which subsequently has a negative impact on human health.
Moisture problems of functional joints of wooden windows – causes analysis
Authors: Palková Adela , Palko Milan , Buday Peter
Published: January 2018

The article addresses the issue of the humidity regimen of a functional wooden window joint. Current energy-saving trends in the buildings bring secondary effects associated with indoor climate change. Increase of the thermal-technical quantification, non-breathability, and diffusion resistance of the building envelope without the solution of controlled ventilation brings an extreme rise of the interior moisture. The passage of moisture through a functional joint is ensured mainly by exfiltration. The energy standard applicable after the year 2020 assumes buildings with almost zero energy need that cannot be reached without a recuperation system. The concept of the recuperation systems usually works as a pressure system, which increases the likelihood of exfiltration. Measurements done in a large climate chamber show that the diffusion of water vapor can overcome the infiltration flow of the outside air. The passage of moisture results in icing or condensation in the functional joint, which subsequently damages the surface treatment of the wood. Another serious defect is the subsequent mold growth.
Comparison of informations from the brownfield catalog and the data needed to evaluate real estate
Authors: Kramářová Zuzana
Published: January 2018

At present, the topic of sustainable development of the area with brownfield revitalization is one of the current topics. The revitalization of each brownfield requires a completely individual approach, but the whole process can be generalized into several successive points: the identification and cataloging of the site, the search for the investor and the new suitable functions for the brownfield, the design phase of the project, the authorization processes for the realization of the project, realization of the project, new use of the site and realistic return on investment. One of the major challenges for revitalization is the search for an investor. This is due to many factors, among which the acquisition cost of the property, which is based on units of measurement, excels. The tool used to encourage potential investors can be, for example, databases - catalogs of existing brownfields. These contain clearly arranged basic information about individual locations. In view of the easier pricing of the brownfield price (its value), it would be advisable to align this information with the necessary valuation data. The paper therefore deals with comparing the information contained in the brownfield databases and the data needed to determine the brownfield price as a real estate.
Exploring physical attributes of walkability from perspective of blind pedestrians
Authors: Bona Frazila Russ , Zukhruf Febri
Published: January 2018

Access has become a crucial issue for the persons with disabilities (PWDs), in which the inconvenient transportation facilities is contributed to the dependent living issue of PWD, specifically the visual impaired person. As a primary aspect of transportation, the walking facilities further needs to be carefully considered for facilitating their moving activities. Recently, the effect of built environment on walking behavior has obtained significant attention, which is generally constructed within the framework of walkability concept. The walkability has been extensively used for evaluating the physical attributes of pedestrian facilities by comparing it to the walker perception. Hence, the evaluation result can directly answer the needs of pedestrian. Despite of their recent research achievements, the walkability concept is mostly unsuccessful to take into account the blind walker characteristics. This paper then explore physical attributes of walkability environment in order to provide the friendly pedestrian facilities for the blind pedestrian, which is rarely explored. The research is established based on the blind walker perspectives within the micro-level analysis that incorporates a smaller unit of measurement (i.e., the street-level physical attributes). The physical attributes result are thus potentially to be utilized for analyzing the required pedestrian facilities for the blind pedestrians.
Porous concrete basic property criteria as rigid pavement base layer in indonesia
Authors: Ridwan Aldila Melania Care Frisky , Sugeng Subagio Bambang , Rahman Harmein
Published: January 2018

Base layer with grained material tend to occur in saturated condition at the
moment of rainfall or after rainfall. In that condition, the present of traffic might also create movement below the foundation layer and reduce its bearing capacity. Nevertheless, the foundation material that contain large fine creates base layer with low permeability and slow water movement. This paper presented the procedure and result of laboratory experimental study to obtain basic property criteria for rigid pavement base layer.The porous concrete mixture was successfully designed and surpassed the minimum requirements required by Directorate General of Highways [11] [12]. It was found that there was very strong correlation between void content and permeability which created fine likelihood to use void content to represent porous concrete permeability behavior. High void content with good connection resulting weaker aggregate interlocking inside the mixture so that permeability rose whereas compressive strength fell. Solid fresh density and more filled by cement paste created a smaller void that would reduce permeability and improve compressive strength. Strong correlation between fresh density towards void content and permeability opened potency to use the fresh density as a reference to set the desired porous concrete void content on the field.
Study on the Effectiveness of Infiltration Wells to Reduce Excess Surface Run Off In ITB
Authors: Mardiah Afifah Muhsinatu , Ainy Cherish Nurul , Bagus Mohammad , Harlan Dhemi
Published: January 2018

Institut Teknologi Bandung (ITB), Ganesha Campus, Indonesia, has an area of 28.86 hectares. The campus is located in Bandung. Starting from 2012, new buildings were constructed within the area, reducing the area of permeable surface significantly. In the past few years, there were several excess run off incidents in the campus. The insufficient area of permeable surface as well as the inadequate capacity of the drainage system contributes to the excess surface run off. The drainage system has only two outlets. Moreover, in some areas, the drainage systems are disconnected. Thus, most the surface run off are stored within the drainage system. The purpose of this study is to evaluate the effectiveness of infiltration wells for reducing the local excess run off in ITB. Precipitation data and drained service area are used to estimate the design discharge from each building in ITB. In order to avoid the excess surface run off of certain locations in ITB, then the infiltration wells are proposed to balance the area of impermeable surface. The effectiveness of the infiltration wells are evaluated by assessing their number to their contribution in reducing the excess surface runs off.
2D Modeling of Flood Propagation due to the Failure of Way Ela Natural Dam
Authors: Yakti Bagus Pramono , Adityawan Mohammad Bagus , Farid Mohammad , Suryadi Yadi , Nugroho Joko , Hadihardaja Iwan Kridasantausa
Published: January 2018

A dam break induced-flood propagation modeling is needed to reduce the losses of any potential dam failure. On the 25 July 2013, there was a dam break generated flood due to the failure of Way Ela Natural Dam that severely damaged houses and various public facilities. This study simulated the flooding induced by the failure of Way Ela Natural Dam. A two-dimensional (2D) numerical model, HEC-RAS v.5, is used to simulate the overland flow. The dam failure itself is simulated using HECHMSv.4. The results of this study, the flood inundation, flood depth, and flood arrival time are verified by using available secondary data. These informations are very important to propose mitigation plans with respect to possible dam break in the future.
Application of Finite Difference Schemes to 1D St. Venant for Simulating Weir Overflow
Authors: Zendrato Nur Lely Hardianti , Chrysanti Asrini , Yakti Bagus Pramono , Adityawan Mohammad Bagus , Widyaningtias  , Suryadi Yadi
Published: January 2018

Depth averaged equations are commonly used for modelling hydraulics problems. Nevertheless, the model may not be able to accurately assess the flow in the case of different flow regimes, such as hydraulic jump. The model requires appropriate numerical method or other numerical treatments in order to simulate the case accurately. A finite volume scheme with shock capturing may provide a good result, but it is time consuming as compared to the commonly used finite difference schemes. In this study, 1D St. Venant equation is solved using Artificial Viscosity Lax-Wendroff and Mac-Cormack with TVD filter schemes to simulate an experiment case of weir overflow. The case is chosen to test each scheme ability in simulating flow under different flow regimes. The simulation results are benchmarked to the observed experimental data from previous study. Additionally, to observe the scheme efficiency, the simulation time between the models are compared. Therefore, the most accurate and efficient scheme can be determined.
Leachate Treatment from Sarimukti Landfill Using Ozone with Sludge from Water Treatment Plant as a Catalyst
Authors: Yudha Ramdhani Muhammad , Rangga Sururi M. , Ainun Siti
Published: January 2018

Leachate is the liquid waste from anaerobic decomposition in a landfill. The ozonation process can be used for leachate treatment. Sludge from sedimentation in water treatment plant contains 5.96% of Al and 9.35% of Si which can affect of its cation exchange capacity and affects the active site in the catalyst. This study aims to determine the effectivity of sludge in the ozonation process to treat leachate. A 1,5 L semi-batch reactor containing 1 L sample was used in this experiment with the rate of oxygen supply was at 4 L/min taken from ambient air. Two groups of sludge weighing 1.5 grams, 3.0 grams and 4.5 grams were used and activate with physically and chemically activated. The best result was obtained by the physically activated sludge with mass of 4.5 gram O3-L-4,5 AF. The differences of removal efficiency between O3-L-4,5 AF with the control (O3) for turbidity were respectively 13.02% and 7.81%, for EC were 10.57% and 8.29%, for COD were 49.44% and 37.50%, and for residual ozone concentration at the end of contact time were 7.6 mg/L and 9.7 mg/L. It can be concluded that activaed sludge and ozonation can be used as a catalyst in leachate treatment.
Initial Study on Building Information Modeling Adoption Urgency for Architecture Engineering and Construction Industry in Indonesia
Authors: Agirachman Fauzan Alfi , Putra Ilham Fajar , Angkawijaya Adam
Published: January 2018

This paper presents our initial study on Building Information Modeling (BIM) adoption urgency for architecture, engineering and construction (AEC) industry in Indonesia. Currently, BIM is being adopted by many countries around the world because of its’ efficiency and other benefits. Meanwhile, most of AEC industries in Indonesia still using the conventional method and there are no regulations from Indonesian AEC authority for adopting BIM. With that situation, a study of BIM adoption in Indonesian AEC industries is important. This study uses a qualitative approach with explorative type. Input from the survey is evaluated qualitatively using content analysis, distribution analysis and correspondence analysis method. Based on analysis result, it shows that BIM as a mean to encourage a more sustainable approach in AEC industry is still in its development phase but it shows great potentials and it gives stakeholders a better way to achieve sustainable built environment. Current lack of awareness and understanding of BIM in Indonesia, particularly in the education sector, is a key factor that impedes BIM adoption and one that can be addressed by integrating BIM into AEC curriculum. Government and practitioners alike need to develop a strategic roadmap to pave way for successful BIM implementation.
Value engineering application for conceptual design of seawater desalination plant in Jakarta
Authors: Mantasa Salve Prastica Rian , Auzan Almasul , Farika Niswatin , Eko Wahyuning Tiyas Nonik , Cahyo Nugroho Pratomo , Apriatresnayanto Riko
Published: January 2018

Jakarta has 10.2 million inhabitants. It has thoughtful problem about clean water availability. Today, only 54% of clean water availability could be supplied to citizens in Jakarta. The urgent need of new clean water resources is highly demanding for Jakarta future life. By employing abundant sea water in the northern part of Jakarta, desalination is a highly effective way that has been proven through value engineering. A conceptual design of desalination project is completed through FAST diagram and benchmarking method. According to life cycle cost analysis, it results IRR 13%, net product value Rp3.782 trillion, payback period of 13.39 years, and benefit cost ratio of 3.00. To make this project complete and reasonable, the public-private partnership should be conducted for modal sharing. This research piloted four analyzed scenarios. The best alternative scenario makes the government budget 60% for initial cost, spend half for operational and maintenance cost, and obtain 20% from the whole project revenue.
Improving Role of Construction Industry for More Effective Post-Disaster Emergency Response To Road Infrastructure in Indonesia
Authors: Pribadi Krishna S. , Puri Eliza , Hanafi Eliya , Hadinata Tri
Published: January 2018

Geo- and hydro-meteorological disasters typically caused disruptive impact to road networks due to damaged road infrastructure, which in turn disconnect access to and isolate the disaster affected areas. Road clearing work and emergency road recovery operation are considered a priority to reconnect the access during post-disaster emergency response. However, the operation is not always smooth and in many cases delayed due to various problems. An investigation is conducted to understand the current practice of post-disaster emergency road recovery operation in Indonesia and to study possible participation of construction industry in order to improve its effectiveness. In-depth interviews with Local Disaster Management Agencies (BPBDs) and local road agencies in West Java Province were conducted to understand current practices in emergency road recovery operation and to view perspectives on local contractor participation. The surveys showed supports from the local governments for contractor involvement as long as it is still under guidance of related agencies (Ministry of Public Works and Housing) despite some possible obstacles from the current regulation that may hamper contractors’ participation, which indicate that there is a potential role of construction industry for more effective post-disaster emergency response, provided that contractor associations are involved and existing procurement regulation is improved.
Study of whole effluent acute toxicity test (Daphnia magna) as an evaluation of Ministry of Environment and Forestry Decree No. 3 In 2014 concerning industrial performance rank in environmental management
Authors: Rohmah Neng , Roosmini Dwina , Septiono Mochamad Adi
Published: January 2018

Only 15% of the industries in Citarum Watershed, specifically in Bandung Regency, West Bandung Regency, Sumedang Regency, Bandung City and Cimahi City, are registered as PROPER industries. They must comply to indicators as set in the Minister of Environment and Forestry Decree No. 3 In 2014 concerning Industrial Performance Rank in Environmental Management, as a requirement to apply for PROPER. Wastewater treatment and management, referencing to Minister of Environment and Forestry Decree No. 5 In 2014 concerning Wastewater Effluent Standards, must be performed to be registered as PROPER industries. Conducting only physical-chemical parameter monitoring of wastewater is insufficient to determine the safety of wastewater discharged into the river, therefore additional toxicity tests involving bioindicator are required to determine acute toxicity characteristic of wastewater. The acute toxicity test quantifies LC50 value based on death response of bioindicators from certain dosage. Daphnia magna was used as bioindicator in the toxicity test and probit software for analysis. In 2015-2016, the number of industries that discharged wastewater exceeding the standard was found greater in non-PROPER industries than in PROPER industries. Based on the toxicity level, both PROPER and non-PROPER industries have toxic properties, however PROPER industries of 2015-2016 is more toxic with LC5096 value reaching 2.79%.
High resolution Thomson scattering system for steady-state linear plasma sources
Authors: Lee K. Y. , Lee K. I. , Kim J. H. , Lho T.
Published: January 2018

The high resolution Thomson scattering system with 63 points along a 25 mm line measures the radial electron temperature (Te) and its density (ne) in an argon plasma. By using a DC arc source with lanthanum hexaboride (LaB6) electrode, plasmas with electron temperature of over 5 eV and densities of 1.5 × 1019 m−3 have been measured. The system uses a frequency doubled (532 nm) Nd:YAG laser with 0.25 J/pulse at 20 Hz. The scattered light is collected and sent to a triple-grating spectrometer via optical-fibers, where images are recorded by an intensified charge coupled device (ICCD) camera. Although excellent in stray-light reduction, a disadvantage comes with its relatively low optical transmission and in sampling a tiny scattering volume. Thus requires accumulating multitude of images. In order to improve photon statistics, pixel binning in the ICCD camera as well as enlarging the intermediate slit-width inside the triple-grating spectrometer has been exploited. In addition, the ICCD camera capture images at 40 Hz while the laser is at 20 Hz. This operation mode allows us to alternate between background and scattering shot images. By image subtraction, influences from the plasma background are effectively taken out. Maximum likelihood estimation that uses a parameter sweep finds best fitting parameters Te and ne with the incoherent scattering spectrum.
Directivity of GHz shear acoustic waves launched by the absorption of short laser pulses at the interface between a transparent and an absorbing material
Authors: Viel Alexis , Audoin Bertrand
Published: January 2018

When a short laser pulse is focused at the interface between a transparent and an absorbing material, an expansion source is created that generates mainly longitudinal acoustic pulses in the absorbing material. However, the interaction of these waves with the interface favours the excitation of shear acoustic pulses. In this paper, we present an analytical prediction of the directivity of shear waves launched in a semi-infinite absorbing medium, and we introduce corrections in order to account for detection in an absorbing layer. Experiments were performed with a picosecond ultrasonic set-up focusing femtosecond laser pulses to a micron spot size along the interface between sapphire and titanium. In this configuration, acoustic wave-fronts were reflected at the free surface of the micron titanium layer, and then optically detected at the interface. We also present an approach to filter and enhance the shear waves by processing measured wave-fronts recorded at multiple locations along the interface. In the resulting signals, the contribution of GHz shear acoustic waves, propagating mainly in directions that are oblique with respect to the interface, is enhanced.
Investigation of the short argon arc with hot anode. I. Numerical simulations of non-equilibrium effects in the near-electrode regions
Authors: Khrabry A. , Kaganovich I. D. , Nemchinsky V. , Khodak A.
Published: January 2018

The atmospheric pressure arcs have recently found application in the production of nanoparticles. The distinguishing features of such arcs are small length and hot ablating anode characterized by intensive electron emission and radiation from its surface. We performed a one-dimensional modeling of argon arc, which shows that near-electrode effects of thermal and ionization non-equilibrium play an important role in the operation of a short arc, because the non-equilibrium regions are up to several millimeters long and are comparable to the arc length. The near-anode region is typically longer than the near-cathode region and its length depends more strongly on the current density. The model was extensively verified and validated against previous simulation results and experimental data. The Volt-Ampere characteristic (VAC) of the near-anode region depends on the anode cooling mechanism. The anode voltage is negative. In the case of strong anode cooling (water-cooled anode) when the anode is cold, temperature and plasma density gradients increase with current density, resulting in a decrease of the anode voltage (the absolute value increases). Falling VAC of the near-anode region suggests the arc constriction near the anode. Without anode cooling, the anode temperature increases significantly with the current density, leading to a drastic increase in the thermionic emission current from the anode. Correspondingly, the anode voltage increases to suppress the emission, and the opposite trend in the VAC is observed. The results of simulations were found to be independent of sheath model used: collisional (fluid) or collisionless model gave the same plasma profiles for both near-anode and near-cathode regions.
Energy density and energy flow of surface waves in a strongly magnetized graphene
Authors: Moradi Afshin
Published: January 2018

General expressions for the energy density and energy flow of plasmonic waves in a two-dimensional massless electron gas (as a simple model of graphene) are obtained by means of the linearized magneto-hydrodynamic model and classical electromagnetic theory when a strong external magnetic field perpendicular to the system is present. Also, analytical expressions for the energy velocity, wave polarization, wave impedance, transverse and longitudinal field strength functions, and attenuation length of surface magneto-plasmon-polariton waves are derived, and numerical results are prepared.
Electronic excitations of manganese phthalocyanine molecules
Authors: Pagenkopf Friedrich , Müller Eric , Knupfer Martin
Published: January 2018

We have investigated the electronic excitation spectrum of individual manganese phthalocyanine (MnPc) molecules in a coronene matrix. Our results corroborate that the observed excitation spectrum is rather sensitive to oxygen contamination of the respective samples. Annealing in vacuum allowed the determination of the electronic excitations of individual MnPc molecules. These results confirm previous data from the literature and, in addition, we have identified a low energy excitation at about 0.8 eV, which had not been reported before.
Numerical analysis of two-fluid tearing mode instability in a finite aspect ratio cylinder
Authors: Ito Atsushi , Ramos Jesús J.
Published: January 2018

The two-fluid resistive tearing mode instability in a periodic plasma cylinder of finite aspect ratio is investigated numerically for parameters such that the cylindrical aspect ratio and two-fluid effects are of order unity, hence the real and imaginary parts of the mode eigenfunctions and growth rate are comparable. Considering a force-free equilibrium, numerical solutions of the complete eigenmode equations for general aspect ratios and ion skin depths are compared and found to be in very good agreement with the corresponding analytic solutions derived by means of the boundary layer theory [A. Ito and J. J. Ramos, Phys. Plasmas 24, 072102 (2017)]. Scaling laws for the growth rate and the real frequency of the mode are derived from the analytic dispersion relation by using Taylor expansions and Padé approximations. The cylindrical finite aspect ratio effect is inferred from the scaling law for the real frequency of the mode.
Calculations of non-adiabatic couplings within equation-of-motion coupled-cluster framework: Theory, implementation, and validation against multi-reference methods
Authors: Faraji Shirin , Matsika Spiridoula , Krylov Anna I.
Published: January 2018

We report an implementation of non-adiabatic coupling (NAC) forces within the equation-of-motion coupled-cluster with single and double excitations (EOM-CCSD) framework via the summed-state approach. Using illustrative examples, we compare NAC forces computed with EOM-CCSD and multi-reference (MR) wave functions (for selected cases, we also consider configuration interaction singles). In addition to the magnitude of the NAC vectors, we analyze their direction, which is important for the calculations of the rate of non-adiabatic transitions. Our benchmark set comprises three doublet radical-cations (hexatriene, cyclohexadiene, and uracil), neutral uracil, and sodium-doped ammonia clusters. When the characters of the states agree among different methods, we observe good agreement between the respective NAC vectors, both in the Franck-Condon region and away. In the cases of large discrepancies between the methods, the disagreement can be attributed to the difference in the states’ character, which, in some cases, is very sensitive to electron correlation, both within single-reference and multi-reference frameworks. The numeric results confirm that the accuracy of NAC vectors depends critically on the quality of the underlying wave functions. Within their domain of applicability, EOM-CC methods provide a viable alternative to MR approaches.