bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Solar Radiation Heat Input into Room on Level of Economically-efficient Thermal Protection of Building
Authors: Malyavina Elena , Frolova Anastasia
Published: November 2019

Techniques for choosing an energy and economically feasible thermal protection of buildings in the climatic conditions of Moscow are discussed earlier. An important basis of these techniques is that it was possible to identify the thermal parameters on the basis of which the generalization of the basic energy and economic indicators of the building, depending on its thermal protection, was carried out. The methods were tested for buildings whose working day lasts from 9 am to 6 pm with various internal heat generation. In this case, it was believed that solar radiation is completely obscured. From consideration of the effect of heat gains on energy-efficient thermal protection, it was found that with increasing heat gains, the load on heating systems decreases regardless of the level of heat protection, and the load on the room cooling systems increases more with higher thermal protection than with low thermal protection. However, there are buildings of a number of functional purposes in which solar radiation is partially obscured or not obscured at all. These include some commercial, residential and other buildings. Accounting for heat gains from solar radiation, with variable intensity throughout the year, makes significant adjustments to the choice of the level of thermal protection. This is due to the fact that often cooling of the room is required during periods when the outside air temperature is below the maximum allowable temperature of the room. During these periods, enhanced thermal protection is an obstacle to the natural outflow of heat from the premises. Calculations showed that the higher the heat gain from solar radiation, the smaller the proportion of buildings it is energetically feasible to warm according to the basic standards stipulated in SP 50.13330.2012. And although it is not energetically feasible to carry out thermal insulation for sanitary and hygienic requirements, the conclusions about the benefits of building insulation with reduced heat transfer to the walls and coatings of a building are economically significant. It is also important that when identifying an economically feasible thermal protection of a building, it is necessary to take into account all the components of financial expenses that are affected by the thermal protection of a building. The calculations also showed that an increase in the cost of heat and electricity over time changes the thermal performance of buildings for which this or that thermal protection is economically feasible.
Case Study of GIS Application in Analysing Urban Heating Island Phenomena in Tropical Climate Country
Authors: Le Minh Tuan , Tuyet Cao Thi Anh , Quan Tran Nguyen Anh , Sadriavich Shukurov Ilkhomhon , Phuong Nguyen Thi Khanh , Cuong Le Thi Kim
Published: November 2019

This study indicates Urban Heat Island phenomena (UHI) in districts belonged to Hanoi city located in tropical climate region. The analysis based on assessment’s comparison by applying remote sensing technology. The data captured in partly cloudy days and at night time by satellite Landsat 5, 7, 8 and is converted subsequently into Land Surface Temperature (LST) range maps. Spatial patterns of UHIs in Hanoi city were examined over the daytime and seasonal variations. Gaussian approximation algorithm is used to quantify spatial extents and measure magnitude for each individual UHIs. Consequently, to determine the relationship of UHIs with surface properties, UHI patterns were analyzed in association with urban vegetation covers and surface energy fluxes derived from high-resolution Landsat 5, 7, 8 data. A general picture of UHI phenomena in Hanoi city in this study and analyzed results, by applying integrating satellite high-resolution thermal data with land-surface modelling and meso-scale climatic modelling, to further address the impacts of urbanization in local climate cities, propose a framework for sustainable urban planning design in the future.
Calculation of Transient Temperature Field in an Inhomogeneous Rock Mass with a Spherical Cavity Filled with a Heated Liquid
Authors: Frolova Irina
Published: November 2019

The problem under consideration is determination of temperature fields in a rock mass with a spherical cavity that is partly filled with a heated liquid. At that, the tendency to self-heating of the substance stored in the cavity leads to appearance of high-temperature fields, that in turn results in development of significant thermal stresses. Herewith, real physical and mechanical properties of the rock within the rock mass must be taken into consideration. So, the rock mass material is viewed through the lens of its inhomogeneity, which to a considerable extent is determined by temperature fields for any instant of hot fluid storage. Herewith, the temperature process is transient, but taking into consideration slow redistribution of the thermal field during a long period of time, the problem of its calculation can be considered as a quasi-steady-state problem. Temperature field around the cavity is calculated using an explicit difference scheme.
Geodetic and Microgravity Measurement used in St. Mary’s Assumption Chapel
Authors: Cesnek Tomas , Chromcak Jakub , Izvoltová Jana
Published: November 2019

With an intersection on modern technologies into the sphere of geodesy and geophysics, there increase the number of possibilities of these technologies to be used. There are also ways to make the research and measurements more attractive for general public. There can be not only interest in the way of final results but also from the processing points of view. For example the sizes of historical sites need to be measured but the semi-product of processing can be also 3D model of the object. This product can be used for increasing of object attractiveness or as a base for next research. This is also the direction needed to be selected, to make the science more attractive and interesting for the public.
Influence of Stone Column Length on the Settlement of Soft Clayey Layer
Authors: Znamenskii Vladimir , Sayed Diaaeldin
Published: November 2019

Currently, geotechnical engineers use stone columns to strengthen weak soils. The usage of stone columns to strengthen soft soil has proven successful, increasing their bearing capacity, reducing the settlement and decreasing the consolidation time. The present study was carried out to investigate the impact of the length of stone columns on the behaviour of soft soils and determine the effective length of stone columns, within which they have the greatest impact on the process of settlement of the soft clay layer. The analysis was performed utilizing a three-dimensional limited distinction numerical model FLAC3D. The results of the study confirmed that with the increase in the length of the stone columns, the settlement of the clay layer decreases. This decrease in settlement is significant to a depth corresponding to the relative length of the piles (L/d) = 10, after that the decrease in settlement practically stops.
Improving the Method of Testing Materials for the Heat Shield of the Building
Authors: Lushin Kirill
Published: November 2019

Thermal protection of the walls is an essential factor in ensuring the quality of indoor air and energy conservation in the building. In the course of testing samples of materials for thermal insulation, a number of features were revealed that lead to a decrease in the quality of results and an increase in the cost of resources for testing. Taking into account the experience of the author suggested ways to improve the methodology.
Simulation of Hydraulic Characteristics for Pipelines Consisting of Different Materials and Diameters
Authors: Orlov Vladimir , Zotkin Sergey
Published: November 2019

This paper deals with aspects affecting problems of coming up with a unified method for assessing the hydraulic compatibility of recovered and non-recovered sections of existing pipeline networks subjected to various methods of trenchless repairs. These issues are closely related to the problem of preserving the transporting ability of the wastewater fluid in a non-pressure pipeline during its trenchless renovation with polymer pipes. Theoretical approaches are given to determine the hydraulic parameters in the pipeline system, taking into account the renovation site and sites adjacent to a segment in question located up and down waste liquid fluid. It is shown that the priority measure to maintain the required degree of self-purification of the recovered pipeline section, as well as adjacent areas, is the magnitude of the water flow rate, which allows to provide required transporting capacity of the pipeline system. A formula to determine the length of the velocity destabilization zone is proposed, and the results of calculations using the automated program developed by the authors are put on display where algorithm includes dependencies determining hydraulic pipeline materials friction coefficients on different parameters as well as diameters, pipeline expanses and their slopes. The essence of the calculations, the sequence of input of the initial information using an automated complex, the type of output table information is described. Comparison of the counting results under different design conditions has been carried out. As conclusions, practical recommendations are presented in the way of managerial decisions for the potential achievement of hydraulic balance in a pipeline system and the creation of conditions under which the destabilization zone at the site after repairs is minimized and the number of preventive cleanings of the pipeline network is also reduced to a minimum.
Practical Analysis and Response for Risks Using Monte Carlo Simulation on Construction Manufacturing
Authors: Al-Sahar Forat
Published: November 2019

This paper discussed a real project supporting the management of project risk. The model distinguishes between risks which have to be enhanced and risks which can be mitigated or accepted at some cost so that the customer requirements with respect to project completion time can be satisfied at a minimal cost. The model is based on risk management analysis proses and using a Monte Carlo simulation and in order to discover the probability to closure project within the expected date plan. The model is illustrated by means of a real-world case concerning a part of real state residential project construction located in the Republic of Iraq.
Influence of the Premises Dustiness Degree in an Educational Institution on the Choice of the Appropriate Air Filter Type
Authors: Frolova Anastasia , Belyy Maxim , Bobrovskaya Anastasia
Published: November 2019

Students and teachers spend about 70% of the day in educational institutions. Therefore, recently in the world studies of the effect of air quality on human well-being and human performance have been conducted more often. The high content of suspended particles in the indoor air can lead to the development of allergies, and also serves as a factor of the transmission of respiratory viral infections. The purpose of this study was to determine the degree of dust in the indoor air in the classrooms. For this purpose, the photoelectric method of registration of aerosol particles and the Koch method were used. The results were evaluated according to two requirements for the amount of suspended particles in the air of the educational institution. Depending on the amount of suspended particles and their size, recommendations were given for filters to reduce the dust content of the internal air.
Method of Modifying of Mineral Fillers for Asphalt Concrete by Calcium Polysulfide
Authors: Inozemtcev Sergey , Korolev Evgeniy
Published: November 2019

The method of modifying the surface of grains of mineral filler for asphalt concrete with calcium polysulphides is presented in the paper. Calcium polysulfide solution has been proposed for the expansion of the mineral resource base in the production of asphalt concrete aggregates, which breaks down into elemental sulphur and calcium hydroxide in the course of filler modification. The proposed modifier reduces the temperature coefficient for the bitumen-mineral binder by 1.8 times. The structure of the composite of highly filled mixtures based on modified filler has higher properties compared to mixtures based on classical filler: compressive strength at temperature 0°C – up to 33.5 %; Compressive strength at a temperature of 20 °C – up to 84 %; Compressive strength at a temperature of 50 °C – up to 34.3 %.
Traffic Related Pollutants and Noise Emissions in the Vicinity of Different Types of Urban Crossroads
Authors: Jandacka Dusan , Decky Martin , Durcanska Daniela
Published: November 2019

Particulate matter air pollution and noise pollution is a problem of everyday life. Particulate matter (PM) is one of the hazardous pollutants causing deterioration of the environment and thus quality of life of the population. Particulate matter and noise pollution by the road transport is a burning issue, particularly for larger urban areas. Air pollution and noise monitoring was focused on a possible change in the concentrations of pollutants and noise level after the change of the crossroad - three-arm crossroad to the roundabout. The subject of this paper is monitoring particulate matter (PM1, PM2.5, PM10) and noise pollution in the vicinity of crossroads in the urban area and an evaluation of fraction ratios PM10, PM2.5and PM1with regard to construction of crossroad, meteorological conditions and traffic volume. Paper deals with the comparison of the noise emissions objectified by direct measurements of noise levels before and after the reconstruction of the three-arm crossroad to the roundabout and comparison of changes in noise ratios detected by direct measurements and predictive calculations. The roundabout has specific construction and routing traffic, what can influence on production and dispersion of traffic related emissions and noise pollution. The obtained results indicate a decrease in particulate matter concentrations at the roundabout compared to the three-arm crossroad. According to the data obtained and analyzed, the PM10particulate matter concentrations at the roundabout could be reduced by up to 50 % over the three-arm crossroad.
Emission factors of NOx and PM of heavy construction equipment used in toll road project in Indonesia – Case study: Rembang-Pasuruan Toll Section II
Authors: Hajji A M , Yulistyorini A , Yue Huang , Patulak D C
Published: November 2019

Heavy duty diesel (HDD) equipment play an important role in constructing Indonesian infrastructure. This paper proposes a methodology for recording an emission inventory for HDD equipment that formulates emission factors as a baseline of current emissions quantities. The sample case of the proposed emissions inventory technique is based on a small part of Indonesia’s national toll road project: Rembang-Pasuruan toll road project. Rembang-Pasuruan toll road is a part of Gempol-Pasuruan toll road, a piece of national infrastructure project called Trans-Java Toll road that runs from Merak, Northwestern end of Java, to Banyuwangi, the eastern end of the island. This toll road connects almost all major cities and landmarks of the island with the total length of the road is nearly 1,167 km. The length of Gempol-Pasuruan toll road is about 34.15 km, and consists of three section: Section I, Gempol-Rembang 13.9 km, Section II, Rembang-Pasuruan 6.6 km, and Section III, Pasuruan-Grati 13.65 km. This toll road project utilizes a HDD fleet that includes 9 excavators, 2 bulldozers, 2 roller compactors, 1 motor-grader and 1 paver. This equipment consumes large quantities of diesel fuel and release air pollutants, including nitrogen oxides (NOx) and particulate matters (PM). The proposed inventory technique in this paper addresses the key attributes of the equipment on how long it is used during its operational life and how emission rates of NOx and PM are estimated. By using emission factors calculated from equipment’s key attributes, it is revealed that all equipment in the project release approximately 452.12 gr/hr of NOx or 3400.97 gr/day on average, and emit 31.99 gr/hr of PM or equals to 252.92 gr/day.
Forensic assessment on landfills leachate through electrical resistivity imaging at Simpang Renggam in Johor, Malaysia
Authors: Zaini M S I , Ishak M F , Zolkepli M F
Published: November 2019

From years to years, the usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in the application of geotechnical engineering owing to the effectiveness of the method in term of time, cost and also data coverage. The forensic assessment performed with respect to the particular reference to ERI in assessing the landfills leachate at Simpang Renggam, Malaysia. There were two lines of ERI performed at the study area using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Furthermore, the analysis made based on the electrical resistivity anomaly managed to detect the presence of chemical contaminants in the soil with particular reference to the chemicals resistivity values which was associated to low resistivity anomaly. Besides, the heterogeneous of the subsurface material presented in the paper by using integrated ERI analysis enabled forensic assessment of the leachate. The leachate from the landfills was believed to occur owing to the failure of the systems in accommodating and treating the waste which became worst with the present of heavy rainfall. In retrospect, the ERI result was applicable to be adopted in detecting the leachate and thus can assist the authority in taking immediate measure to prevent the frequent water disruptions at the study area.
Shifting cropping shifts by efficient irrigation water to produce maximum rice productivity
Authors: Azis S
Published: November 2019

Agriculture is the main support of the economy in Indonesia so that the sustainability of the productivity of paddy fields must be maintained properly. Rice fields rely heavily on irrigation water supplies from technical rigs. Continuity of water flow must be maintained in accordance with water requirements and cropping patterns in each paddy field. In connection with changes in conditions lately there has been a shift in the rainy season and the dry season which results in erratic discharge of surface water both in quantity and on time so that the use of irrigation water must be done wisely and efficiently to maintain the productivity of the yield of paddy fields. From the results of the implementation of the cropping pattern set by the relevant agency there has been a deviation of 13.81%, which means that it is necessary to improve the implementation of cropping patterns and adjust the time of rain so that rice productivity remains maximal.
Life cycle assessment of low costs housing in Indonesia
Authors: Zuraida S , Wahyuni Y S , Larasati D
Published: November 2019

Housing demands in Indonesia cause an increase in the supply needs of building materials where some of these materials have a negative impact on the environment. Life Cycle Assessment (LCA) method is used to assess the potential environmental impact caused by housing demand of low-costs housing in Indonesia which its types are standardized to types of 21, 36 and 45. The data of building materials were collected from some developers that involved in development of low-costs housing. Embodied Energy (EE) and Carbon Emission (CE) were used as indicators of LCA. The result of the study showed that EE and CE value is increasing linearly by the addition of housing area. It also found out that material volume has significant value to rise EE and CE. Based on the result, with the same volume of square meters, the amount of energy used to build two types of houses 21 was higher than type of 45 houses.
Planned investigation of UTES potential in Algeria
Authors: Amara S , Baghdadli T , Nordell B
Published: November 2019

The unbalance between supply and demand of heat can be managed by thermal energy storage (TES). For large-scale systems the underground is used as storage medium or storage volume. Aquifer storage (ATES) is most suitable for very large applications, Borehole storage (BTES) the most general system in all scales and the rock cavern storage (CTES) is best suited for extremely high loading/extraction loads. The construction of any of these systems requires knowledge about site-specific properties of the ground i.e. geology and groundwater conditions. Current paper gives a brief review of the potential and advantage of Underground Thermal Energy Storage (UTES) technology utilization in buildings for the hard climate.
Performance of SCS unit hydrograph and kinematic wave methods application on rural and urbanized watershed
Authors: Sharaswati D , Soeryantono H , Anggraheni E , Sutjiningsih D
Published: November 2019

Flood routing in the catchment area can be simulated by transform method. Based on the complexity of data requirement, there are two significant differences of the transform method in watershed routing, namely the SCS Unit Hydrograph and Kinematic Wave. The purpose of this study is to analyze the effectiveness of those two methods by comparing two hydrographs using HEC-Geo HMS on Urban and Rural Watersheds. Comparison has been simulated by calculating the ratio of peak hydrograph discharge to each calculation condition and the level of hydrograph compatibility. Another possibility to analyze the effectiveness of two methods by plotting accumulative discharge values from the two hydrographs produced by the SCS Unit Hydrograph method using the Kinematic Wave method. The results of the hydrograph comparison indicate that Kinematic wave method which requires more detailed data more suitable for Urban Watershed than SCS Unit Hydrograph. However, for the Rural watershed, SCS Unit Hydrograph shows satisfactory result.
Water quality indices for rainwater quality assessment in Bandung urban region
Authors: Hasan N Y , Driejana  , Sulaeman A , Ariesyady H D
Published: November 2019

Water quality indices (WQI) using STORET method has been used to assess rainwater quality in the Bandung urban regions, based on monitoring data at three locations (Coblong, Sumur Bandung, and Buah Batu). Rainwater samples were analyzed by detecting pH, SO4
2-, NO3
−, Cl−, and heavy metals (As, Cd, Cr, Pb, and Zn) compared with Indonesian Government Regulation No. 82 Year 2001. Rainwater quality showed polluted based on the parameters of the water quality indices analysis using the Class I and Class II criteria. Rainwater quality in Bandung urban region were lightly polluted (Coblong) and moderately polluted (Sumur Bandung and Buah Batu). Rainwater can potentially become a water sources alternative for domestic use and urban farming in Bandung urban region, but it requires further treatment for better quality.
Tensile test analysis of cold-formed column in channel profile
Authors: Aziz A A , Nindyawati N , Karyadi K
Published: November 2019

This study analyzes the joint capacity of cold-rolled steel frame structure for multi-level buildings to withstand axial loads. The column frame joint structures will be modeled, analyzed and tested. In this paper, the study is about cold-formed channel profile that will be tensile tested with 2 variations of the joint. The research objectives are (1) to determine the stress and strain, (2) the damage pattern. The test object is modeled using FEM with a scale of 1: 1 and the loading used is linear static loading. Simulation with FEM use a trial and error method by entering the parameters obtained. The draft and design of channel profiles using cold rolled steel material refers to several guidelines including SNI-7971-2013 on Cold Formed Steel Structures.
Confinements of concrete cylinders using bamboo spiral stirrups
Authors: Nindyawati N , Sulton M , Pratama M M A , Rahayuningsih T
Published: November 2019

Confinement affects the increase in beam flexural capacity. The strain stress relationship of concrete cylinder compressive strength is used to analyze the beam and column capacity. The area of the curve of the concrete cylinder core with confinements is wider than the curve without confinements. Confinements can also increase ductility and shear strength of reinforced concrete structural elements. The paper aims to determine the effect of bamboo spiral stirrups distance on normal strength concrete. Concrete cylinder size 150 mm x 300 mm. Variation in crossing distance of 30 mm, 50 mm, 70 mm and without confinement. Confinements on cylinders are bamboo and steel spiral stirrups. The results show that concrete cylinders with steel confinements increase the compressive strength by 45% of the concrete cylinder without confinements. Concrete cylinders with bamboo confinements increase the compressive strength by 28 %.
Simulation of float of 19 passenger aircraft during landing on water surface
Authors: Ardiansyah Riki , Adhitya Mohammad
Published: November 2019

The 19-passenger plane was modified to land in the water by making a landing gear with a float. The floats used are imported products that have previously been used by similar aircraft. Float must be able to support the aircraft and can accept impact loads when landing. This study aims to determine the effect that occurs in float when making water surface landings. Stress and displacement are simulation outputs that are the focus of research. These parameters are obtained by numerical simulation methods based on Civil Aviation Safety Regulation (CASR) by varying input parameters such as: landing speed. From the results of the study it was found that the faster the velocity then the output of the stress and displacement response from the float becomes larger.
A damage sensitive feature: Beam case
Authors: Gunawan Fergyanto E , Sekishita Nobumasa
Published: November 2019

With the adoption of damage tolerance design principle, the health monitoring system has become an integral part of the engineering structure in operation. For the system to work, damage indicator that describes the structural integrity level should be established and monitored. Damage indicator is usually derived from structural responses. Many quantities have been proposed for damage indicator. Some popular damage indicators are natural frequency, mode shape, curvature, strain energy, and t-, F-, and z-statistics. In this paper, we propose a new damage indicator derived from the theory of the strength of materials. We evaluate the proposal for a case involving damage on a simply-supported beam. The required data are established numerically by the finite element method for structure in healthy and damaged conditions. The results suggest that the current proposal is more sensitive to damage than the natural frequency.
Heat and Mass Transfer in 2-Propanol Droplet Evaporation: Analysis Modified Stagnant Film Model
Authors: Prasetyo D , Kosasih E A
Published: November 2019

Heat and mass transfer is an evaporation process from liquid droplet that occur in spray drying technology. So, it becomes important to understand the basic elements of spray drying, namely droplet. The formation technology involves drying is used in many industries. Various models of analogies of heat and mass transfer analogies have been formulated, with the aim of obtaining the characteristics that occur in the system. The analogy model most often used to obtain heat and mass transfer coefficients from droplet is the analogy model Ranz W. E. and Marshall W. R. The analogy has requirements, including the Lewis number (Le) which ranges in the number one. The purpose of this experiment is to compare the results obtained from the analogy of the Ranz-Marshall equation model applied to the droplet by making a modification of the C1 and C2 values that exist in the stagnant film model. In this experiment, the analysis results obtained from the modification of the stagnant film model is that the heat transfer phenomenon that occurs in droplet does not yet fully have good results. Where the value of C1 still cannot represent the value that can be used to obtain C2 properly.
The Effect of Vacuum Quenching on Corrosion and Hardness of the Surface of SKD61 Steel
Authors: Luthfiyah Syifa , Faridh Ahmad , Soegijono Bambang
Published: November 2019

JIS SKD61 Steel is chromium-molybdenum hot work steel which has composition 5.58 wt% Cr – 2.51 wt% Mo. This steel is a well-known material used as a die material to get good mechanical and hardening properties. Besides this material should have good corrosion resistance. Samples made of SKD61 steel were subjected to vacuum heat treatment at 1030°C for 3 hours with step quenching in different rates of quenching. The difference in the cooling speed of each sample causes properties on the surface to vary. Micro Hardness Vickers is a tool used to determine micro-scale hardness. While to test corrosion resistance, electrochemical testing was carried out using NaCl solution with variations in concentrations of 1%, 3.5%, and 7%. X-Ray Diffraction was used to characterize the crystal structure and the crystallite size. The results show that the speed of quenching affects the hardness of the surface of the material, structure and corrosion resistance.
Effect of Ramie Fibers on Fatique Strength Automotive Product
Authors: Komang Astana Widi I , Pohan Gerald , Sujana Wayan , Nani Prihatmi Tutut
Published: November 2019

The automotive industry is already utilizing many composite materials for its products since composite materials are very environmentally friendly, have low economic costs and able to reduce weight. Ramie fiber reinforced by natural composites have a great opportunity to be used as materials for automatic components. The mechanical bonding of the ramie fiber reinforced composite pad can be improved by increasing the compatibility between the matrices and good product handling technique. In addition, the mechanical behavior is also greatly influenced by the orientation of the fibers in different matrices. This paper will discuss the effect of fiber orientation (unidirectional, woven and random) on several resin matrices (epoxy and polypropilene). The purpose of this study is to observe the effect of ramie fiber orientation on fatigue resistance properties in the form of handle components. The observations used SEM (scanning electron microscope) for observing of the failure mechanism. Fatigue test of the specimens using 80s carry-type handles (in situ). Handling fatigue testing equipment is specially designed in accordance with the application of the load. The strength of the fatigue observed in the handle component shows that the optimum value is produced in the handle with the orientation variation of fiber in both the epoxy matrix and the polypropylene matrix, namely 17141 and 8414 cycles. The presence of ramie reinforcement fibers in general can increase the fatigue strength of handle components. Whereas the lowest fatigue strength is owned by fibers which have a random orientation. However, when compared with no fiber, the component handles with randomly oriented fibers still have better fatigue strength.
Using Geopolymer Composites for Heat and Corrosion Resistant Pipes
Authors: Su’udi A , Akmal J , Tanti N , Arizon
Published: November 2019

This research studied the use of carbon fiber reinforced geopolymer composites as corrosion resistant pipe material. Geopolymer material is a general term for material synthesized from fly ash. Fly ash is an industrial by-product (coal combustion residue) with high silica content (SiO2) and Alumina content (Al2O3). In addition there are also other elements in a relatively small percentage. This material will compound like cement if activated with Sodium Silicate. This study aims to obtain the optimum composition for high quality mechanical properties. The method used is to synthesize material with various elemental compositions. Furthermore, a mechanical test (bending test) is performed to see the effect of each element to be optimized. Besides that, a physical test in the form of SEM-EDX was also conducted to see the microstructure. Materials with optimum composition have been fabricated as pipes with centrifugal casting process. Mechanical testing of pipe samples is done by hoop tensile strength test. The test results show that the strength of geopolymer composites can achieve 58 MPa.
Stirring Effect on Surface Morphology, Structure, and Electrochemical Behavior of Electrodeposited Nickel Film on Copper Substrates
Authors: Budhi Susetyo Ferry , Faridh Ahmad , Soegijono Bambang
Published: November 2019

Nickel as engineering material has good corrosion resistance properties. Nickel has been deposited on copper surface by electrochemical deposition with various stirring speed. Objective on this research are to observe the effect of stirring on morphology, structure and electrochemical behavior. Electrodeposited nickel film on copper substrates was conducted with various stirring speeds (0 rpm, 75 rpm, and 150 rpm). Surface morphology was observed with Field Emission Scanning Electron Microscope (FE-SEM), structure was identified with X-ray diffraction (XRD), and electrochemical behavior was investigated by potentiodynamic polarization and cyclic voltammetry. Stirring speed effect clearly on the surface morphology, structure and electrochemical behavior. Corrosion potential and corrosion current are changes while the stirring speed is increase.
Effect of magnesium fluoride coating on corrosion behaviour of magnesium alloy
Authors: Saliza Azlina O , Shafiq Ruba’ai Mohd , Kurniawan D
Published: November 2019

Magnesium and its alloys are explored as potential biomedical materials for being lightweight, bio-absorbable, and having attractive biological properties. A major hindrance for their use is their high corrosion rate, in particular when exposed to body fluids. This study aims at suppressing the corrosion rate of a magnesium alloy (Mg1.0Ca) by coating it with magnesium fluoride (MgF2). The coating was done by immersion of the workpiece in hydrofluoric acid solution. For comparison, pure magnesium was also coated with MgF2. The MgF2coated magnesium exhibits significantly lower corrosion rate than pure magnesium. The MgF2coated magnesium alloy shows even lower corrosion rate. The MgF2coating works in inhibiting corrosion on magnesium alloy Mg1.0Ca. The corrosion inhibition was also contributed by other compound formed during reaction between Mg1.0Ca and hydrofluoric acid and the alloy in Mg1.0Ca.
Federalism: A Very Short Introduction
Authors: Rozell Mark J. , Wilcox Clyde
Published: November 2019

Federalism: A Very Short Introduction provides a concise overview of the principles and operations of federalism, the political system defined by power sharing between a national government and its subnational units, from its origins and evolution to the key events and constitutional decisions that have defined its framework. While the primary focus is on the United States, a comparative analysis of other federal systems, including those of Australia, Brazil, Canada, India, Nigeria, and Switzerland, is provided. The role of federal government is explained alongside the critical roles of state and local governments. This VSI also examines whether federal structures are viable in an era of increasingly centralized and authoritarian-style government.
Country Music: A Very Short Introduction
Authors: Carlin Richard
Published: November 2019

Country Music: A Very Short Introduction presents an overview of country music and its impact on American culture. Country music has long been a marker of American identity; from popular culture to politics, it has provided a soundtrack to national life. While traditionally associated with the working class, country music’s appeal is far broader than any other popular music style. While this music rose from the people, it is also a product of the popular music industry, and the way the music was marketed to its audience is a key part of its story. This VSI considers country music’s roots and development, and describes key artists, songs, and musical styles.
Philosophy of Biology: A Very Short Introduction
Authors: Okasha Samir
Published: November 2019

Philosophy of Biology: A Very Short Introduction outlines the core issues with which contemporary philosophers of biology grapple. Over the last forty years the philosophy of biology has emerged as an important sub-discipline of the philosophy of science. Addressing difficult conceptual issues that arise within the biological sciences, it also encompasses areas where biology has impinged on traditional philosophical questions, such as free-will, essentialism, and nature vs nurture. The book also explores topics such as the logic of Darwinian evolution; the concepts of function and design; the nature of species; and the debate over adaptationism.
2. Fossil fuels
Authors: Jenkins Nick
Published: November 2019

For the last 300 years the world has relied on fossil fuels—coal, oil, and natural gas—for its energy. The widespread availability, high-energy density, ease of transport and storage, and the generally low cost of fossil fuels has facilitated the development of modern society with all its benefits. ‘Fossil fuels’ explains, however, that the extraction and combustion of fossil fuels has severe impacts on the environment. It is accepted by most policy makers that continuing to burn carbon based fossil fuels cannot be sustained and we need to move quickly towards energy systems that emit greatly reduced amounts of CO2, but fossil fuels will continue to play an important role in energy supply for some years.
Tides: A Very Short Introduction
Authors: Bowers David George , Roberts Emyr Martyn
Published: November 2019

The tide is the greatest synchronized movement of matter on our planet. Every drop of seawater takes part in tidal motion, driven by the gravitational pull of the Moon and Sun. Tides: A Very Short Introduction blends clear explanations of well-known tidal phenomena with recent insights into the dynamics of the deep ocean and coastal seas, considering the tide’s nature and causes, its observation and prediction, and unusual tides and their relevance. It explains the importance of ocean tidal mixing as a key part of our planet’s climate-control system and for enhancing biological productivity. It also considers the effects of tidal processes beyond our own planet on the moons of Jupiter and Saturn.
What Is the Time of Literature?
Authors: Hayot Eric
Published: November 2019

Two recent books, Ted Underwood’s Distant Horizons (2019) and Cody Marrs and Christopher Hager’s edited volume, Timelines of American Literature (2019), offer new ways of thinking about how literary scholars and institutions use concepts of time. Underwood’s book argues that the tendency to think of literary history as composed of large stylistic shifts between schools is undermined by an approach focused on computational analysis of stylistic features. Marrs and Hager’s volume showcases a wide variety of periodizing and temporal experiments designed to help us rethink the nature of American literature.
CoMM-S2: a collaborative mixed model using summary statistics in transcriptome-wide association studies
Authors: Yang Yi , Shi Xingjie , Jiao Yuling , Huang Jian , Chen Min , Zhou Xiang , Sun Lei , Lin Xinyi , Yang Can , Liu Jin
Published: November 2019

Motivation

Although genome-wide association studies (GWAS) have deepened our understanding of the genetic architecture of complex traits, the mechanistic links that underlie how genetic variants cause complex traits remains elusive. To advance our understanding of the underlying mechanistic links, various consortia have collected a vast volume of genomic data that enable us to investigate the role that genetic variants play in gene expression regulation. Recently, a collaborative mixed model (CoMM) was proposed to jointly interrogate genome on complex traits by integrating both the GWAS dataset and the expression quantitative trait loci (eQTL) dataset. Although CoMM is a powerful approach that leverages regulatory information while accounting for the uncertainty in using an eQTL dataset, it requires individual-level GWAS data and cannot fully make use of widely available GWAS summary statistics. Therefore, statistically efficient methods that leverages transcriptome information using only summary statistics information from GWAS data are required.

Results

In this study, we propose a novel probabilistic model, CoMM-S2, to examine the mechanistic role that genetic variants play, by using only GWAS summary statistics instead of individual-level GWAS data. Similar to CoMM which uses individual-level GWAS data, CoMM-S2 combines two models: the first model examines the relationship between gene expression and genotype, while the second model examines the relationship between the phenotype and the predicted gene expression from the first model. Distinct from CoMM, CoMM-S2 requires only GWAS summary statistics. Using both simulation studies and real data analysis, we demonstrate that even though CoMM-S2 utilizes GWAS summary statistics, it has comparable performance as CoMM, which uses individual-level GWAS data.

Availability and implementation

The implement of CoMM-S2 is included in the CoMM package that can be downloaded from https://github.com/gordonliu810822/CoMM.

Supplementary information

Supplementary data are available at Bioinformatics online.
A Bayesian zero-inflated negative binomial regression model for the integrative analysis of microbiome data
Authors: Jiang Shuang , Xiao Guanghua , Koh Andrew Y , Kim Jiwoong , Li Qiwei , Zhan Xiaowei
Published: November 2019

Microbiome omics approaches can reveal intriguing relationships between the human microbiome and certain disease states. Along with identification of specific bacteria taxa associated with diseases, recent scientific advancements provide mounting evidence that metabolism, genetics, and environmental factors can all modulate these microbial effects. However, the current methods for integrating microbiome data and other covariates are severely lacking. Hence, we present an integrative Bayesian zero-inflated negative binomial regression model that can both distinguish differentially abundant taxa with distinct phenotypes and quantify covariate-taxa effects. Our model demonstrates good performance using simulated data. Furthermore, we successfully integrated microbiome taxonomies and metabolomics in two real microbiome datasets to provide biologically interpretable findings. In all, we proposed a novel integrative Bayesian regression model that features bacterial differential abundance analysis and microbiome-covariate effects quantifications, which makes it suitable for general microbiome studies.
Clinic-Level Factors Associated With Retention in Care Among People Living With Human Immunodeficiency Virus in a Multisite US Cohort, 2010–2016
Authors: Oliver Cassandra D , Rebeiro Peter F , Shepherd Bryan E , Keruly Jeanne , Mayer Kenneth H , Mathews W Christopher , Turan Bulent , Moore Richard D , Crane Heidi M , Geng Elvin , Napravnik Sonia , Kitahata Mari M , Mugavero Michael J , Pettit April C
Published: November 2019

Background

Retention in care (RIC) leads to reduced HIV transmission and mortality. Few studies have investigated clinic services and RIC among people living with HIV (PLWH) in the United States. We conducted a multisite retrospective cohort study to identify clinic services associated with RIC from 2010–2016 in the United States.

Methods

PLWH with ≥1 HIV primary care visit from 2010–2016 at 7 sites in the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) were included. Clinic-level factors evaluated via site survey included patients per provider/trainee, navigation, RIC posters/brochures, laboratory test timing, flexible scheduling, appointment reminder methods, and stigma support services. RIC was defined as ≥2 encounters per year, ≥90 days apart, observed until death, administrative censoring (31 December 2016), or loss to follow-up (censoring at first 12-month interval without a visit with no future visits). Poisson regression with robust error variance, clustered by site adjusting for calendar year, age, sex, race/ethnicity, and HIV transmission risk factor, estimated risk ratios (RRs) and 95% confidence intervals (CIs) for RIC.

Results

Among 21 046 PLWH contributing 103 348 person-years, 67% of person-years were retained. Availability of text appointment reminders (RR, 1.13; 95% CI, 1.03–1.24) and stigma support services (RR, 1.11; 95% CI, 1.04–1.19) were associated with better RIC. Disparities persisted for age, sex, and race.

Conclusions

Availability of text appointment reminders and stigma support services was associated with higher rates of RIC, indicating that these may be feasible and effective approaches for improving RIC.
Future perspectives in catheter-based treatment of pulmonary embolism
Authors: Sharp Andrew S P , Attallah Antonious
Published: November 2019

Pulmonary embolism is the third commonest cause of cardiovascular death globally. The majority of such patients present with low-risk features and can be managed with simple anticoagulation; however, a large group of patients exhibit evidence of right ventricular dysfunction on echocardiography or CT at the time of presentation and these patients are at risk of early haemodynamic compromise, particularly in those with abnormal cardiac biomarkers. Catheter-directed thrombolysis has been proposed as a treatment-strategy for patients with pulmonary embolism with evidence of acute right ventricular dysfunction. We review the current technologies in mainstream use, the evidence base in support of their use and discuss future research requirements in this area.
The emergence of colistin-resistant Escherichia coli in chicken meats in Nepal
Authors: Joshi Prabhu Raj , Thummeepak Rapee , Leungtongkam Udomluk , Pooarlai Renukar , Paudel Saroj , Acharya Mahesh , Dhital Samita , Sitthisak Sutthirat
Published: November 2019

The emergence and dissemination of colistin resistance among Gram-negative bacteria is a global problem. We initiated a surveillance of colistin-resistant and -susceptible Escherichia coli in raw meats from chicken in Nepal. A total of 180 meat samples were collected; from these, 60 E. coli strains were isolated (33.33%), of which 16 (26.66%) were colistin-resistant and harboured the mcr-1 gene. All isolates were characterised by antibiotic susceptibility testing, the presence of antibiotic resistance genes, phylogenetic analysis and plasmid replicon typing. Most of the colistin-resistant E. coli had the antibiotic resistant pattern CIP/CN/SXT/TE (43.75%). Coexistence of tet, qnr, sul and dfr genes was detected in both colistin-resistant and -susceptible E. coli. Most colistin-resistant E. coli strains belonged to phylogroup C, whereas 10% of isolates belonged to phylogroup D. Inc FIB was the dominant plasmid Inc type in the isolates. Dissemination of antibiotic-resistant E. coli in raw meats is a public health concern in Nepal and requires further investigation to ascertain the sources of contamination.