bluuebunny/crossref_metadata_2025 huggingface dataset:
Upscaling the flexibility potential of space heating in single-family houses
Authors: Dréau Jérome Le , Mellas Ilyasse , Vellei Marika , Meulemans Johann
Published: November 2019

Energy flexibility from residential buildings is foreseen as a solution to facilitate the integration of variable energy sources in the grid. In fact, the energy use in residential buildings is still high despite the different building regulations and some of their usages can be shifted in time. Among these usages, space heating showed an interesting potential for flexibility, especially in France, where 45% of the heating systems is electrical. The objective of this study is to evaluate the flexibility potential in typical French houses, looking at both the energy shifted and thermal comfort. Large differences are highlighted, mainly due to the thermal properties of the envelope and the type of emitter. The temperature drops are quick in poorly insulated building. Underfloor heating systems show a good flexibility potential due to the inertia of this type of emitter. Finally, quantitative data, such as the mean power decrease and power profiles, is provided to help the integration of flexible buildings in future energy grids.
The SMART sensor: fully characterizing radiant heat transfer in the built environment
Authors: Houchois Nicholas , Teitelbaum Eric , Chen Kian Wee , Rucewicz Sean , Meggers Forrest
Published: November 2019

In a conventional indoor environment, thermal comfort is supplied by an air based distribution system. This system is controlled by an air temperature (and occasionally humidity) sensor, and the role of radiation in thermal comfort is often overlooked. In a typical indoor environment, slightly less than half of the heat occupants shed to maintain thermal comfort is lost to convection. The other portion is lost to radiation. We have developed the Scanning Mean Radiant Temperature (SMART) Sensor to fully characterize radiant heat transfer in the built environment. Combining surface temperatures and geometry allows us to produce 3D thermal point clouds which may be meshed to produce watertight surfaces. The view factor between occupants and environmental surfaces may be calculated, allowing us to accurately model radiative heat transfer. Additionally, this may be calculated for any location in the space, allowing us to map spatial variation of the mean radiant temperature from a single scan. In this paper, we use the SMART sensor to calculate the spatial distribution of mean radiant temperature over a range of environmental conditions. Its performance is validated using a net radiometer. The sensor demonstrates that there is frequently significant spatial variation of mean radiant temperature in typical indoor environments up to 4 °C.
Distributed model predictive control of building energy systems coupled to geothermal fields
Authors: Baranski Marc , Stoffel Phillip , Kümpel Alexander , Stiller Martin , Storek Thomas , Schumacher Markus , Müller Dirk
Published: November 2019

In building energy systems (BES), operation strategies are a key factor to exploit the full potential of renewable energy sources and thus to reduce the CO2 emission and energy costs. However, advanced operation strategies like model predictive control require high engineering effort, which limits the applicability. To ease the implementation of model predictive control in BES, we present a flexible and robust distributed control framework. The framework supports the use of different model types and timescales for the various subsystems, allowing the user to tailor models from white to black modelling according to the available system knowledge. In a case study, we apply this framework to control a real-life industrial hall. We further simulate a case in which the hall is supplied by a geothermal field to investigate the sustainable long-term control of the field. We vary the temperature setpoint of the hall and adjust the thermostats in the office rooms. Since the set temperature of the hall and offices differs, the model predictive control framework finds an economic trade-off between the requirements of those two zones. Judging from these results, the approach and our implementation could be an important contribution to energy efficient operation of buildings with renewable energy sources.
Air to water heat pumps for heating system retrofit in urban areas: understanding the multi-faceted challenge
Authors: Calame Nicole , Freyre Alisa , Rognon Fabrice , Callegari Simon , Rüetschi Matthias
Published: November 2019

Air has an important role to play as a renewable resource to supply heat in urban areas. The implementation of heat pumps in multifamily buildings represents an important and underexploited development potential. Financial comparison of heating costs depending on building size and heat production technology shows how retrofit projects with air-to-water heat pumps compare to gas. Feedback from experience based on pilot projects presents the various challenges faced and proposes solutions.
The impact of battery storage technologies in residential buildings with sub-daily autonomy and EV contribution
Authors: Chatzivasileiadi Aikaterini , Ampatzi Eleni , Knight Ian P.
Published: November 2019

This study has been undertaken to gain a better understanding regarding the choice and impact of battery storage technologies in a use case with contribution of an electric vehicle to the overall domestic consumption. The study assessed the storage requirements of nine battery technologies for different residential building scales at the distribution level considering sub-daily autonomy periods. The use case explored in this paper assumed that the battery from an electric vehicle could contribute to the overall domestic consumption during the required hours of storage based on a scenario addressing demand response through peak shifting in 2030 (DR 2030) from an earlier study. After deriving the nominal capacity for each battery technology, the spatial requirements, including footprint, volume and mass, as well as the cost, for the scales of interest were estimated. The study showed that space and cost savings of up to 90% compared to a use case that do not consider EV contribution could be achieved. The choice of the most suitable technology according to its applicability in different building scales and different use cases should be carefully assessed.
Building integrated photovoltaic at NEST – Preliminary test bedding results
Authors: Wittkopf Stephen
Published: November 2019

This paper presents preliminary results on the visual and energy assessment of colored photovoltaics modules installed at the Meet2Create unit of the NEST pilot- and demonstration site at Empa in Dübendorf. The installation contains mono-crystalline PV modules with three different types of front glass (float, silk and satinated) and three different patterns printed on them (shutter, curve and ornament). Each printed PV module and three unprinted reference modules are monitored separately over a period of one year. With float glass, the visual appearance is dominated by reflections of the environment, an disturbing effect that does not appear with the matte and brighter satinated glass, where the colored print pattern remains visible across all viewing angles. Interestingly, the energy output is relatively similar. Compared to the unprinted reference PV modules, the losses with float, silk and satinated glass are 68, 75, and 72% respectively. While the different print patterns do not yield a significant difference. Satinated glass is thus an interesting alternative to the common float and structured front glass when visual appearance and energy efficiency matters.
Optimization method for photovoltaic integration in residential houses
Authors: Kichou Sofiane , Skandalos Nikolaos , Wolf Petr
Published: November 2019

Good design and sizing of photovoltaic (PV) systems is very important in order to effectively harvest energy and minimize the investment cost. The optimum tilt and azimuth angles at which a PV system should be installed are often debated. This paper evaluates the trade-off between annual energy generation and payback period reduction through the analysis of a small house with pitched roof integrated PVs in both East and West sides. Validated irradiance and PV models were used for the analysis. The optimum tilt and azimuth angles are found to be 35° and 10° respectively. Finally, a contour map plot illustrating all possible tilt and orientation angles, corresponding to a payback period less than 20 years, is provided. The results are valid for different building typologies and locations with similar climate conditions as Prague.
Simulation tool for planning smart urban districts in a sustainable energy supply – integrating several sectors in high resolution
Authors: Stickel Matthias , Marx Simon , Mayer Felix , Fisch Manfred Norbert
Published: November 2019

A tool for practical planning of smart urban districts has been developed, considering integration into sustainable energy supply. It is based on dynamic energy simulation in high resolution, focusing on sector coupling and individual control strategies in a simple workflow. It provides energy flows and climate balances of individual scenarios. The model includes district grids, all essential supply systems, energy storages and electrolysis (power to gas). The tool was successfully applied to implement an innovative energy concept and to realize one of the first climate neutral operated urban districts in Esslingen Germany.
Estimating time constants for underfloor heating control
Authors: Kull Tuule Mall , Thalfeldt Martin , Kurnitski Jarek
Published: November 2019

Time constants are used for tuning PID control parameters and should be correctly estimated to achieve a well-performing controller. However, the estimation of time constants for a very slowly reacting system such as underfloor heating is not easy in practice. In this work, different methods were used to estimate the time constants for underfloor heating. Graphical estimation and transfer function fitting were the core approaches. Measurement data and simulations on a calibrated model were used for the estimations. The resulting time constant values for the graphical method depended clearly on the setback duration and the values differed up to a factor of 100. For the transfer function method, time constant values did not vary significantly. For light construction, the time constant was around 10 hours and for massive, around 30 hours for the otherwise identical room.
Demand response potential of aggregated high-temperature storage radiators
Authors: Cai Hanmin , You Shi , Klyapovskiy Sergey , Bindner Henrik W.
Published: November 2019

This study experimentally evaluates the demand response potential of aggregated high-temperature storage radiators to support intermittent solar photovoltaic (PV) production. Nine storage radiators on one floor of an office building located in Copenhagen’s Nordhavn area are aggregated. Their demand response potential to compensate for the forecast errors of production from a large-scale PV installation in the same area is analysed. From experimental results, it is found out that the aggregated storage radiators have an activation time of 15 seconds and could provide a significant amount of energy storage while maintaining end-users’ comfort.
Sensitivity analysis of a simplified office building
Authors: Zeferina Vasco , Wood Ruth , Xia Jianjun , Edwards Rodger
Published: November 2019

The increase of thermal discomfort and the associated energy demand for the cooling of buildings further exacerbate the ongoing challenges for the design of new buildings and the adaptation measures of the current building stock to climate change. Dynamic, detailed and tailored building simulation methodologies are necessary to better understand and quantify the energy demand of buildings and consequences for supporting energy networks. The aim of this is to analyze the sensitivity of peak electricity demand for the provision of space cooling to different office building model parameters. In the research, two sensitivity methods, Morris Elementary Effect and Sobol, are used to evaluate the sensitivity of eight input model parameters. Relative to peak power consumption for cooling, the most important factor is the cooling set-point, followed by ventilation rate and internal heat gains, which are estimated to account for 38%, 26% and 25% of the variation. Regarding the annual cooling demand for the HVAC systems, these factors account for 35%, 33% and 58%, respectively.
Which sensor type at which location should offices with south orientated window choose to improve comfort and reduce energy consumption?
Authors: Borier O Minam , Kazanci O B , Olesen B W , Khovalyg D
Published: November 2019

The common placement of thermostats in offices might not reflect the actual thermal environment around occupants and influence the energy use. In this research, it is questioned which type of thermostat at which location better represents the conditions in the occupied zone and what is the effect on energy use. To answer this, simulations of indoor thermal environment, experiments in a climatic chamber and calculation of the energy use are performed for a two-person office room with a south orientated window. The results obtained allow to provide recommendations about the thermostat type and its placement in the office space.
Assessing the impact of outside view on learning: a close look to EN 17037 ‘view out’ practices through the analysis of 220 classrooms
Authors: Kuhlenengel Michael , Waters Clarence E. , Konstantzos Iason
Published: November 2019

The purpose of design standards and guidelines is to ensure occupant safety and aid in occupant well-being and satisfaction. Educational buildings such as schools should extend this aim, by also promoting student learning, something that has triggered literature in the past suggesting significant correlation between learning performance and the indoor environment. EN 17037 “Daylight for Buildings” is a recently approved European standard that seeks to assess and ensure successful daylit spaces, including sections on protection against glare, exposure to sunlight, and view out. EN 17037 includes three ways of assessing view out in buildings including, Horizontal sight angle, Outside distance of the view, and Number of view layers outside of windows, a combination that potentially makes it an efficient way to describe such a complex concept. This paper will use a large data set of 220 K-12 classrooms in the Midwest region of the United States in order to evaluate whether any of these three levels of assessing view, or combinations of them can show potential effects on student achievement. The Number of view layers showed a significant positive effect on reading achievement. However, none of the metrics were found to be significant with respect to math achievement. These results aim to identify the next steps of a future controlled study towards a better quantifiable understanding of outside view perception, while also triggering a conversation about the main factors connected to outside view that should be considered towards an indoor environment that promotes learning and productivity.
A method for the retrofitting of pre-1914 Walloon dwellings with heritage value
Authors: Stiernon Dorothée , Trachte Sophie , Dubois Samuel , Desarnaud Julie
Published: November 2019

The sustainable energy renovation of historical buildings and listed heritage is a challenge for Belgium and other European countries. These are crucial for urban and rural development and for the future of old buildings. This is the context of the ‘P-RENEWAL’ research project. It aims to develop a methodological tool for retrofitting historical Walloon dwellings built before 1914, to enhance their heritage values while implementing relevant energy measures. The originality of this research is to consider energy, environmental and heritage aspects in a complementary way, in order to help designers achieving a goal of greater sustainability. According to the listed heritage administration, dwelling types built before 1914 represent approximately 25 % of the Walloon stock. This project is related to the research work carried out under the Task 59 of SHC ‘Renovating Historic Buildings Towards Zero Energy’. The methodology used to achieve the research objectives is articulated in various steps. First, a typological analysis of buildings from the interest era is completed. Then, based on on-site studies performed on representative case studies, the evaluations of heritage values and performance are conducted. Finally, dynamic energy models are run to support the proposition and validation of retrofitting strategies.
Renovation strategies of typical Danish single-family house for optimization of energy efficiency and flexibility
Authors: Marszal-Pomianowska Anna , Johra Hicham , Loukou Evangelia , Liu Mingzhe , Pomianowski Michal , Sharif Nadin Hisham , Monne Laia-Tuixent Morgo , Polonowa Una
Published: November 2019

Buildings will play a significant role in providing a safe and efficient operation of the future energy system. The aim of this work is to investigate how typical cost-effective renovation packages contribute to energy consumption reduction as well as influence the energy flexibility in a Danish single-family from 1970s, and if simple rule-based controller can contribute in peak shaving strategy. By choosing the different renovation packages, the space heating demand can decrease between 34 - 64% and the flexibility time can increase between 200 – 500%. Depending on the cut-off period, the simple RBC of turning off the heating power can further reduce the heating consumption and contribute in reducing the morning load peak with small compromise on the thermal comfort level.
Predicting the thermal performance of thermochromic flat plate solar collectors
Authors: Krammer Anna , Schüler Andreas
Published: November 2019

A thermochromic vanadium dioxide (VO2) based absorber coating is proposed. The optical response of the multilayered absorber is first simulated, then, the spectral reflectance of the deposited absorber is measured. The determined solar absorptance and thermal emittance values are used to predict the thermal performance of the thermochromic flat plate solar collector. The corresponding stagnation temperature is estimated to be ∼25°C lower than that of a standard collector. This is mostly due to the increase in emissivity over the thermochromic phase transition and, partially, to a lower solar absorptance than in standard absorbers. However, a concurrent increase of the solar absorptance over the phase transition limits the overheating protection abilities of the thermochromic collector. Alternative scenarios based on thermochromic absorbers with assumed, constant solar absorptances and the same temperature dependent thermal emittance as determined for the measured sample, are considered. The corresponding thermal performances and stagnation temperatures are predicted and discussed.
The information and communication technologies in the administration of the processes and systematization
Authors: Rodríguez J P , Moreno L Y
Published: November 2019

The objective of the research is to describe how Information and Communication Technologies allow not only to organize in the strain bank microorganisms obtained from different environments for application in academic, research and extension processes, but also to continue characterizing microorganisms obtained from different environments for application in all these processes. Results it has been observed that the absence of Information and Communication Technologies as a strategy to organize and select viable microorganisms already identified can continue to be used and applied in industrial processes, environmental, agricultural food and pharmaceutical industry, among others, has caused the dispersion and loss of information, hindering the easy and timely recovery of the products generated, not being recorded and stored information that is generated. The “Laboratorio de Investigaciones en Microbiología Avanzada y Biología Aplicada” must create its own website and web application that allows strengthening the strain bank, allowing them to be visible with the production generated there.
Design of a mechanical seeder
Authors: Ospina-Bayona H E , Sánchez-Torres C C , García-León R A , Ballesteros-Ruiz H A , Pérez-Lozano B C
Published: November 2019

In the agricultural production processes that are carried out in most of the Colombian regions, some deficiencies can be observed in the way in which the seeds are sown. This is a task that is carried out manually, generating physical problems in the workers due to the enormous effort that they must make, in addition to the precariousness in how these works are carried out. The long periods that are involved in sowing greatly hinder its efficiency, something that directly affects the economy of the farmers. The purpose of this work is to design a mechanical seeder that facilitates the work of the operators by eliminating the manual operation of it and equipping them with equipment that performs the furrows in the ground and at the same time sows the seed. The results obtained corroborate that there is an adequate structural design, which will support the forces to which the machine will be subjected. In this way, it will be possible to contribute to the improvement of the sowing conditions of the farmers of the region. This design takes into account the number of seeds sown per hectare, which is about 20 kg. These data were obtained from farmers belonging to the Universidad Francisco de Paula Santander seccional Ocaña. Additionally, maximum deformation analysis was performed on the chassis, obtaining values of 1.791×10−4 m, as well as structural analysis using the Solidworks drawing tool.
Alkaline pre-treatment and hydrolysis with acid cellulase of the rice husk (Oryza sativa) for production of bioethanol
Authors: Cacua A , Gelvez J J , Rodríguez D C , Parra J W
Published: November 2019

Several companies generate large amounts of agroindustrial waste, which could be used as raw material for the production of bioethanol; among them, those that process and commercialize rice, which produce a large amount of husk, a lignocellulosic material, as a by-product. These companies generally use rice husk as fuel for the ovens, generating problems to the environment due to the emission of polluting smoke. The objective of this work was to obtain bioethanol from rice husk, taking advantage of its cellulose and hemicellulose content. The lignin was removed by an alkaline pretreatment with 2.00% w/v sodium hidroxide solution. Cellulose and hemicellulose in the husk were hydrolysed by enzymatic hydrolysis with acid cellulase for 72 hours. During this period of time, the concentration of total reducing sugars was monitored by the 3,5-dinitrosalicylic acid method, in order to determine the reaction time in which the highest concentration of total reducing sugars is obtained. The sugars obtained were fermented with saccharomyces cerevisiae, for the production of alcohol. During the enzymatic hydrolysis of the pre-treated rice husk, it was found that the highest concentration of total reducing sugars in the samples was 7.778 g/L, obtained in a time of 24 hours of hydrolysis. The sugars obtained were fermented with Saccharomyces cerevisiae, for alcohol production. A distillate was obtained with a concentration of 3.7% v/v.
A review about the use of industrial by-products in the lightweight aggregates production of expanded clay
Authors: Cáceres J R , Rojas J P , Sánchez J
Published: November 2019

The fabrication lightweight aggregates in recent years has included the addition of industrial by-products in the expanded clay manufacture as modifier agents of the expansion capacity, and also as a destination for the disposal of waste and residues in countries where lightweight concrete is used for the construction of high-rise structures. This article provides a review of the use of by-products as additives in the production of lightweight aggregates from expanded clay available in the literature. As a methodology, the bibliographic search was used through the consultation of specialized databases such as Sciencedirect and other documentary sources of open access scientific journals in several countries. The selection criteria for documents were specified according to the frequency the by-product use. 58 references on investigations by-products addition to the lightweight aggregates production were revised. In conclusion, the study of the use of Colombian byproducts as additives in the expanded clay aggregates production is suggested as a research subject due to the absence of articles related to this topic.
Effect of force angle on the strain distribution of osseointegrated dental implants
Authors: Forero L , Castilla R , González-Estrada O A
Published: November 2019

In this work, we investigate the response of the anisotropic maxilla bone in the peri-implant region, when osseointegrated implants are subjected to external forces at different angles, based on the stress and strain distribution by the finite element method. Models were created to represent a portion of a maxilla bone (upper first molar region) with two types of implants which have different thread geometry (squared and V-shaped) and material (Ti-6AL-4V ELI and grade IV Titanium). Compressive axial (150 N) and oblique load (150 N at 45° angle) were applied to anisotropic models of the bone tissues. Complete osseointegration was assumed. Results demonstrated that the increase of the implant inclination leads to a more critical behaviour. Oblique loading is more detrimental to stress and strain distribution than axial load. Stress fields were more efficiently distributed by squared thread implants.
Sinplafut: A microservices – based application for soccer training
Authors: Vera-Rivera F H , Vera-Rivera J L , Gaona-Cuevas C M
Published: November 2019

Microservices are an architectural style of service-oriented applications that allow the application to be divided into independent and autonomous units, which can be individually developed, tested, deployed (mainly in the cloud), scaled and monitored. The application then becomes a composition and integration of small distributed systems. In this paper, a case study is presented, where the Information system for the planning of soccer training, is developed, following the architectural style of microservices. It presents the architecture defined for the information system and its implementation using DevOps practices, among them, continuous delivery, continuous deployment and automated tests. The level of granularity of each microservice is evaluated using domain-driven design and the definition of delimited contexts. Defining the optimal size of microservices is fundamental, directly affecting performance, maintainability, storage, transactions, distributed queries, use and consumption of network and computational resources. On the other hand, the development of the information system allows improving the planning of soccer training using modern sports training techniques. System for the planning of soccer training can be used by soccer teams, clubs, physical trainers, coaches and technical directors both amateur and professional, as a software as a service application.
Integration of big data in small and medium organizations: Business intelligence and cloud computing
Authors: Camargo-Perez J A , Puentes-Velasquez A M , Sanchez-Perilla A L
Published: November 2019

Although it is well known, organizations are becoming increasingly concerned about how they make use of information and thus obtain the greatest benefit from it for competitive purposes and continuous improvement in a globalized world of constant change, large volumes of data produced by organizations turn out to be a key element in decision-making for productive purposes, the multinationals already do it, why not integrate it into small and medium-sized companies? Today small and medium enterprises are still making decisions based on intuition, which do not take into account the information, intuition in most cases does not work as a good guide for decision making, in small and medium enterprises bosses or owners of these manage their companies more by the experience acquired through the years that often do not take into account the technological advances that are being developed to improve their processes.
Diagnosis of horizontal pipe leaks using neural networks
Authors: Gómez-Camperos J A , Espinel-Blanco E E , Regino-Ubarnes F J
Published: November 2019

This document presents an experimental study that supports probabilistic decisions based on neural networks to detect the presence of leaks in pipeline transport systems, since such leaks can cause serious consequences. In addition to the economic losses presented by the lost product, process stoppage and repair of the damage, there can be insurmountable environmental and social losses such as the death of human beings. The probabilistic model correlates measurements of inlet and outlet pressures and flow to the state of leakage. The study and experimentation presented in this work are based on information acquired by simulating the behavior of the fluid in a pilot tube installed in the Fluid Mechanics laboratory of the Universidad Francisco de Paula Santander, Seccional Ocaña. Finally, experimental tests were carried out to obtain the data of the physical variables of the flow sensors at the entrance and exit, with these data a multilayer neural network of perception was trained. The results obtained from the test equipment, with intentionally caused leaks, showed that the structure of the multilayer Perceptron neural network was capable of detecting leaks in the pilot tubes. With the accomplishment of this work it was found that the neural network presents favorable results at the time of detecting the leak compared with other methods of detection since this one presents immunity to the noise, a parallel structure and, consequently, capacities of fast processing and classification.
Bioconversion of post-culture wastewater from farm fisheries for the production of high-value algal biomass
Authors: Gámez-Ortiz L P , Gónzález-Soto M J , Perez-Roa M E , García-Martinez J B , Urbina-Suarez N A , Diaz-Castañeda C E
Published: November 2019

Post-consumption water from inland fisheries possesses a tremendous environmental impact on aquatic ecosystems due to their high load of nutrients such as Nitrates, Phosphates, Urea and organic load. Due to the high cost of current water treatment systems, most of the waters from inland fisheries are discharged without any treatment, thus generating a significant environmental impact in rivers of different localities. Cyanobacteria are a group of photosynthetic microorganisms that can grow in different environments including wastewater. Among the most industrially exploited cyanobacteria, Spirulina (Arthrospira) maxima is the most relevant microorganism, due to its capacity to produce large quantities of protein and colourants (especially phycocyanins) for the food and feed industry. The objective of this project is to determine the maximum production capacity of Spirulina in post-consumption waters of fish farming as a system for the treatment of this type of water through the biological capture of the various nutrients and the production of biomass of industrial interest. S. maxima was produced on 3 different media (wastewater + Zarouk, wastewater + K2HPO4, NaNO3, NaHCO3 and wastewater without any modification) for 30 days. Results shown that S. maxima can effectively grow on wastewater supplemented with NaNO3 (2.5 g/L), NaHCO3 (16.8 g/L) and K2HPO4 (0.5 g/L) to obtain up to 1.18 g/L of total biomass and 0.23 g/L of phycocianins. The scaling of culture at 10 L showed a minimal reduction on final biomass and phycocyanin (1.05 and 0.21 g/L respectively), this result indicates that the production of biomass and phycobiliproteins from S. maxima in wastewater from inland fisheries can be a possible candidate for the simplification of biomass and high-value metabolites process production.
Hydrological similarity of catchments in the southern area of Colombian Andean region
Authors: Carrillo-Soto G A , Cely N J , Ayala-Ibarra M L
Published: November 2019

In every branch of science, the classification of the object of study shows the degree of understanding reached. Hydrology seeks this sorting system that classifies watersheds globally, a highly complex issue given the degree of heterogeneity of climates, geomorphology, vegetation cover, soils and geology. This project provides ideas on the possibilities of classification of basins in the southern region of the Andean zone in Colombia, from hydrological similarity point of view, evaluated by means of "signatures" that synthesize the hydrological functioning of the basin. Five signatures were considered: Runoff coefficient, base flow index, slope of the flow duration curve, discharge-precipitation elasticity, and hydrograph rising limb density. Geomorphological characteristics and values of hydrological signatures were determined for 25 catchments. Two classification methodologies were implemented: k-means clustering and classification and regression trees. The grouping identified two groups for base flow index, rising limb density and slope of the flow duration curve firms, and three groups for the remaining runoff coefficient and streamflow-precipitation elasticity. No significant correlations were found between hydrological signatures and climatic and geomorphological characteristics, suggesting a degree of complexity within hydrological processes that require the inclusion of other components such as vegetation and soils characteristics. By applying regression trees, the basins were grouped into 4 classes, with the slope of the flow duration curve being the main discriminator and the rising limb density in the second level. The importance of the flow duration curve as an indicator of hydrological processes and the rising limb density as an indicator of the climatic component, the driving force of said processes, is highlighted.
Conceptions of distance education and financial mathematics from an onto-historical understanding
Authors: Paz Montes L S , Parra López H M , Vergel Ortega M
Published: November 2019

Mathematics as a system of knowledge organized in distance education, in continuous expansion is applied in almost all disciplines of knowledge, is aimed at stimulating the development of cognitive skills, as well as analytical and critical skills, whose importance lies in the theory of value, seeks to discover manifestations to the development of the capacity for self-determination, collective autonomy and solidarity. The research was developed under the mixed paradigm, supported by a historical-dialectical and quantitative approach of confirmatory factor analysis, having as key informant’s managers, tutors, graduates and students of different programs of distance education. His ontology from the nature of the reality, was to generate a theoretical and didactic approach from the onto - historical understanding of financial mathematics in the trajectory of programs in distance education. The results obtained show that there is a significant relationship between the modality, the critical dialogical approach in the teaching of financial mathematics and technology. It is concluded that the conception of distance education is determined as an opportunity to be professional, for low-income youth who live in vulnerable areas, and have labour commitments. The structural model identifies factors, motivation, human relationships and resources, associated with the conception and development of cognitive skills in financial mathematics
Development dynamics of the industry in Khakassia, technological solutions for a coal cluster
Authors: Bulakina E N , Nedzelsky O N , Bikineeva A N , Moiseyev V V
Published: November 2019

Today the coal industry of Khakassia takes the third place according to the index of industrial production, regarding extraction of coal, among regions of Siberia and the 14th place in Russia. Its further development is connected with creation of a coal cluster on the basis of enterprises producing and processing coal. There are all necessary modern capacities in the Republic. There are two coal processing plants, crushing and sorting complexes and also favorable conditions for developing transport networks connected to the perspective centers of coal mining in the country, capable to increase volumes of producing and processing coal, to increase quality of products. It is noted that the foundation of coal mining in Russia was laid at the end of the 17th century. The first deposits began to be mined near modern Donbass (area of the Kalmius river and the river Seversky Donets). The coal industry is one of major export developing industries of local economy.
Scientific substantiation of the technological scheme of robotized mine with the use of underground hydraulic mining equipment
Authors: Fryanov V N , Pavlova L D
Published: November 2019

This article analyzes and evaluates the possibility of improving the technology of underground coal mining, taking into account the achievements of the basic sciences, robotics and digital technologies in recent decades. According to the results of the analysis, it was established that at present the deposits of coal seams suitable for open-cut mining are almost completely exhausted by the industry. One of the ways to increase the volume of coal mining is the gradual replacement of the open-cut mining by manless underground method with remote control of mining processes and maximum use of digital technologies and wireless communication. Hydraulic technology is the most adaptive to manless underground excavation. The technical means for constructing the technological scheme of hydromine of a new generation and the technological requirements of the excavation robot for underground manless coal mining were substantiated.
Numerical simulation of interaction of methane filtration and rock massif deformation during mining of methane-bearing seams
Authors: Fryanov V N , Pavlova L D , Petrova O A , Shiryaev S N
Published: November 2019

This paper presents the results of the first stage of theoretical research and mathematical modeling of interaction of geomechanical and filtration processes in methane-bearing coal-seams when mining them in gravitational and non-uniform geotectonic stress fields. Comprehensive studies were carried out on the basis of numerical modeling of geomechanical and gas-dynamic processes with adjustment of the input parameters of the mathematical model based on the results of mine measurements. According to the results of numerical modeling, the features of the residual strength distribution of the coal seam to the original one, displacements, vertical and horizontal stresses, methane pressure in the rock mass at different coefficients of lateral pressure in the undisturbed geomassif and in the zone of influence of the gob are revealed. It also presents the results of computational experiments for determining the geomechanical and gas filtration parameters in the rock massif with different options of the boundary conditions and the spatial position of the workings.
Waqf private property trust fund as property unlock initiative
Authors: Jalil Rohaya Abdul , Yaacob Ahmad Che , Omar Ismail , Sipan Ibrahim@Atan , Ridza Badrul Hisham Mohd , Fadzli Siti Zulfarina
Published: November 2019

The abundant of Waqf land (WL) administrated by State Islamic Religion Council (SIRC) are growing over the years unsolved. The location of these WL are strategic and capable for commercial benefits through property development investment project. Yet, the development funds’ constraint restraints SIRC to develop the WL’s potential. This study examine the structure of management of indirect real estate investment (IREI) instrument and carried out a benchmarking comparison analysis to suggest a workable IREI to unlock WL potential. But, concept of Waqf prevents sub-sale of Waqf ownership exchange transaction. While, private property trust fund (PPTF) is a close fund and distribute dividend. This study suggest a conceptual idea Waqf private property trust fund (WPPTF) as mechanism for WL unlock initiative. The structure of management of WPPTF is different since Waqf unit holders whom cash donor would not receive any investment return, instead SIRC as a caretaker of Waqf properties benefit all investment return. The acceleration of Waqf property potential would be useful for investment project development of more frozen WL.
Microwave assisted ZnCl2 activation of salacca peel derived activated carbons as adsorbents for Cu(II) removal from aqueous solution
Authors: Arie Arenst Andreas , Kristianto Hans , Atin Jessica , Arifin Christiandi
Published: November 2019

In this present study,salacca peel based activated carbons (SPAC) were prepared by microwave assisted ZnCl2 activation method. The effects of microwave power, activation time and impregnation ratio on the characteristics of activated carbon were studied. The activated carbons were characterized by N2 adsorption-desorption and scanning electron microscopy (SEM) instruments. The BET surface area of 1796 m2/g were obtained at a microwave power of 540 W, activation time of 25 minutes with an impregnation ratio (ZnCl2:salacca peel) of 4:1. The resulting activated carbon was used for removal of Cu(II) from aqueous solution. The prepared activated carbons were then used as adsorbents for removing Cu(II) metal ions from aqueous solutions. The adsorption equilibrium was investigated using using Langmuir, and Freundlich model equations. It was found that the adsorption equilibrium data followed the Langmuir isotherm equations with maximum capacity of 1262.62 mg Cu(II)/g SPAC at room temperature. The adsorption kinetics were also studied using the pseudo first order, pseudo second order and intraparticle diffusion models. The adsorption kinetics was shown to fit well with the pseudo second-order kinetic model.
Treatment of batik wastewater using plant derived surfactant-enhanced ultrafiltration membrane
Authors: Aryanti N , Nafiunisa A , Irmalasari L N , Nisa I M K , Wardhani D H
Published: November 2019

Saponin extract from pericarps of Sapindus rarak DC is utilized to replace synthetic surfactant in the surfactant-enhanced ultrafiltration process. The process conducts to treat real batik wastewater. The extraction by maceration methods was performed in the various ratio of solute to solvent. The extract with proper calculation is used in the wastewater treatment process in various CMC concentration. The highest yield is obtained at solute to solvent ratio of 1:40 (w/v). The flux value of solution without saponin is higher than the one with saponin addition.The flux value is decreased by the increase of saponin concentration on the feed solution. Thelowest average flux value of 31.35 L/m2.h was obtained from the feed solution with saponin concentration of 2 times CMC. Both processes with and without the addition of saponin exhibit permeate flux declined over time. This is due to the interaction of saponin molecule with the pollutant where the pollutant is covered by saponin molecules. The membrane performance shows that saponin is successfully worked to solubilize or bounded the heavy metal molecule, dyes molecules, and other pollutants on its micellar structure. This is proved by the decrease of Cr and COD concentration after the ultrafiltration process enhanced with saponin. Saponin at the concentration of 2 times CMC giving the best result with lowest Cr and COD concentration of 18.3 ppm and 108.4 ppm, respectively, and highest rejection of Cr and COD of 95.88% and 96.91% respectively.
Adsorption processes based activated carbon from waste biomass and its application as a raw material ceramic membrane wastewater in processing kain songket
Authors: Dahlan Muhammad , Saleh Abdullah , Prahady S , Tan Azizah
Published: November 2019

The main environmental problem in the textile industry is the waste from the dyeing process. Heavy dye and heavy metals are water pollutants. The most widely used method in water treatment is filtration using membrane technology. Membrane technology has several advantages, such as separation process that can occur at room temperature and its use is not destructive. In this research will be made membrane with basic forming material such as bentonite, clay (clay), activated carbon as additive in filtration process. The activated carbon used is made from avocado seed which is carbonized with a temperature of 500°C for 1 hour. This research is used to know the influence of flow rate and the best time of contact with ceramic membrane during the treatment of songket wastewater and to know the result of ceramic membrane use with different type of active carbon raw material to the treatment of songket liquid waste which can fulfill the condition of the waste water ready dispose of by water quality standard. Parameters examined TSS, BOD, COD, PH, and turbidity. The contact time used during the filtration process is 30 minutes, 60 minutes, 90 minutes, 120 minutes and 150 minutes. As for the flow rate used 3L / min and 5L / min. From the result of the research, it is known that the best result of waste samples with 150 minutes contact time and 3L / min flow rate.
Evaluation on the Mechanical Properties of Steel-Fiber Concrete at Elevated Temperatures
Authors: Purwanto  , Antonius  , Setiyawan Prabowo
Published: November 2019

This paper presents experimental results on mechanical properties of steel-fibre concrete burned at high temperatures, which consists of tensile strength, modulus of elasticity and flexural modulus. The steel-fibre usage is limited to 0.5% of concrete volume. The reviewed parameters in the evaluation include compressive strength of normal to high-strength concrete, and temperature (normal, 300°C, 600°C, 900°C). The specimens are heated up after it reached 120 days of age. Experimental results toward mechanical behaviour indicate that tensile strength tends to decline linearly at 300°C and 600°C respectively. The value of modulus of elasticity and flexural modulus of fibre-reinforced concrete heated at 300°C, 600°C and 900°C tend to decline linearly. The results of the experimental evaluation also proposed a model for tensile strength degradation equation, modulus of elasticity and flexural modulus against temperature.
Integration of Digital Elevation Model (DEM) and HEC-RAS Hydrodynamic Model for flood routing
Authors: Tunas I G , Arafat Y , Azikin H
Published: November 2019

The development of computer technology, especially the hydrodynamic modeling package, provides convenience in many things including flood modeling in the river. One of these modeling packages is HEC-RAS Hydrodynamic Model which can be used to simulate both steady flow and unsteady flow. On the other side, the development of Geographic Information System (GIS), is now rapidly evolving for a variety of purposes with a wider range of fields and scope, including the preparation of river geometry data based on Digital Elevation Model (DEM) in Triangulated Irregular Network (TIN) format as the input of the model. The aim of this study is to perform flood routing for determining the river capacity and for estimating the factors that cause floods by integrating TIN data into HEC-RAS Hydrodynamic Model, using Lantikadigo River in Central Sulawesi, Indonesia as a model. In this river, almost every year flooding occurs with fluctuating intensity of inundation. Integrating data is the process of synthesizing geometry data that is processed in the GIS environment as input for the HEC-RAS Model. Data integration provides the effectiveness of the use of simulation time due to input geometry data is done using import data facility when compared manually input geometry data. The results of the study show that the maximum water level of the 1-year return period has exceeded the river bank elevation both on the left and on the right side of the entire segment. The peak discharge of hydrograph for 1-year return period is 55.3 m3/s at the outlet of Lantikadigo Watershed. This means that the average channel capacity is far below the peak discharge. Based on simulation results it can be predicted that the cause of flooding in Lantikadigo River is due to morphological change of river geometry.