bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication of Zeolite-Geopolymer Hybrid Bulk Materials Based on Laterite Soils Deposit Gowa Regency, South Sulawesi, Indonesia
Authors: Dewi Permatasari Anita , Akifah Nur , Syamsih Amalia Nur , Rizal Fahlepy Muhammad , Sudarman Desa Susilo , Subaer  
Published: August 2019

Abstract
In this study, zeolite-geopolymer hybrid bulk materials were fabricated by using laterite soils deposit Gowa regency, South Sulawesi, Indonesia as a precursor for possible heavy metal absorbent. Laterite soils was calcined at 750°C for 6 hours to transform it into the amorphous aluminosilicate phase. Zeolite-geopolymer materials were produced through alkali activation method with curing temperature around 70°C for 2 hours. There were two different oxide molar ratios of SiO2/Al2O3 used to produce zeolite-geopolymer hybrid bulk materials and the specimens were designated as K1 and K2. The presence of zeolitic phase within geopolymer network was examined by using of XRD, FTIR, and SEM-EDS technique. The mechanical properties of the resulting material were studied by means of compressive and tensile strength. The results showed that Gowa laterite soil was succesfully fabricated as zeolite-geopolymer hybrid bulk materials, and the type of zeolite coined with geopolymers were zeolite A in sample K1 and un-named zeolite in sample K2. The mechanical strengths of zeolite-geopolymers produced in this study were below to those of pure geopolymers.
A preliminary study of thermal comfort and lighting in IHL library building
Authors: Hussin Norasikin , Abd Razak Azli , Baharum Faizal , Yaakob Y. 
Published: August 2019

Abstract
IHL (Institute of Higher Learning) library building is greatly utilized to access information from IT connection and materials. This building as a place to study, reading and writing for students and academics in the university. However, the indoor air quality and lighting system in the library building is not comfort and not satisfactory. In this paper, the investigation of thermal comfort and lighting in IHL library buildings. The library building of LBA, LBB and LBC has been selected. This study has been done with distribution of 350 set of questionnaires. The result shows that 63% of respondents claimed that uncomfortable with the environment because is very cold, which is indoor temperature in average of 20ºC. Meanwhile, 54.3% of respondents are unsatisfied with lighting level because it is too dimmed and most of them prefer to study near the window because of daylight. By lux meter reading, the illumination in average of 225 lux. From the reading, recommendations were made in order to enhance the thermal comfort and potential energy saving.
Removal of Nickel, Zinc and Copper from Plating Process Industrial Raw Effluent Via Hydroxide Precipitation Versus Sulphide Precipitation
Authors: Ain Zainuddin Nur , Azwan Raja Mamat Tengku , Imam Maarof Hawaiah , Wahidah Puasa Siti , Rohana Mohd Yatim Siti 
Published: August 2019

AbstractElectroless plating wastewater contains mixed metals element. Although precipitation is the most common method applied to remove metals from the wastewater, it fails to completely precipitate all the metals at a single pH. The present work evaluates the effectiveness of the sulphide and the hydroxide precipitation for removal of nickel, zinc and copper from industrial wastewater, namely acid rinse and nickel rinse samples. The optimum pH and coagulant dosage were determined via Jar Test for both types of samples. Sulphide precipitation removed heavy metals more efficient than hydroxide precipitation. For the acid rinse sample, 95.32% of nickel was removed using sulphide precipitation while 76.66% removal using hydroxide precipitation. For nickel rinse sample, 93.75% of zinc was removed using sulphide while 68.8% removal using hydroxide. 65.75% of nickel was removed using both sulphide and hydroxide. Total removal of copper was achieved for both hydroxide and sulphide precipitation, either from acid rinse or nickel rinse samples.
Assessment of Ambient Air Pollution in Langkawi Island, Malaysia
Authors: Elis Sharmila Zulazmi Nur , Zia Ul-Saufie Ahmad , Nur Shaziayani Wan Mohd Rosly Wan , Mohamed Noor Norazian , Aida Zubir Nor 
Published: August 2019

Abstract
For many years, Southeast Asia region encountered several ongoing air pollution episodes. These episodes had indirectly significant impact on the air quality of neighboring countries. Hence, this study aims to assess the characteristics and trend of air pollution in Malaysia particularly at Langkawi Island. Air pollution hourly monitoring records from 2003 to 2017 were used in analyzing the statistical data analysis. Eight parameters were selected in this study which known as PM10, CO, SO2, NO2, O3, relative humidity (RH), temperature (T) and wind speed (WS). The results showed that the hourly trends of PM10, CO, SO2, NO2 and O3 in Langkawi Island were below the MAAQG standard. The results also indicated that dispersion of PM10 in Malaysia were significantly affected by temperature, wind speed and relative humidity.
Synthesis of dimercaptosuccinic acid (DMSA) coated magnetic nanoparticles: feasibility on dye decolorization and heavy metal adsorption
Authors: Syazwan Osman Mohamed , Asyiqin Noorossaidy Noorfarah , Azis Najwa , Syifa Salim Nur , Aqilah Zaini Nur , Alwani Ali Bashah Nur 
Published: August 2019

Abstract
As highlighted in UN sustainable development goals 2030 report, one of the important challenge in future is to provide clean water. Thus, enormous efforts have been made to improve water quality from recalcitrant pollutants such as organic dyes, heavy metal and others. Magnetic nanoparticles is one of viable candidate to degrade the above pollutants due to its unique properties such bifunctional (catalytic and adsorption) capability & ease for magnetic separation. However, one of the main challenge is to maintain its colloidal stability to exploit its advantages for water remediation. Thus, this work explored its colloidal stability by coating it with heavy metal chelating agent namely Dimercaptosuccinic Acid (DMSA). The resultant clustered magnetic nanoparticles were evaluated its feasibility by using Rhodamine B dye and lead (Pb) heavy metal as model system. It is revealed that DMSA-coated magnetic nanoparticles is a viable candidate for this model system.
Screening of factors influencing Pectin Extraction of Pomelo peels using 2-Level Factorial Design
Authors: Pagarra Halifah , Rahman Roshanida A. , Muis Abd. , Novia Arifin dan Arifah 
Published: August 2019

Abstract
A study was conducted to vary the parameters affecting the extraction of pectin from pomelo peels (Citrus maxima) using a 2-level factorial design (2LFD). Experimental design was carried out to screen for significant environmental factors for extraction results. The factors involved consisted of pH, temperature and extraction time. The results of the variance analysis (ANOVA) found three main factors that had a statistically significant effect on the results of pectin extraction, namely pH, temperature and extraction time. The following important factors are the interaction factors between pH and temperature, the interaction between temperature and extraction time, the interaction between pH and extraction time, the interaction between temperature and extraction time. Statistical analysis shows that the linear model is significant with R2 value of 0.9715. It was found that pH, temperature and extraction time are the most important parameters that affect the results of pomelo peels pectin extraction.
Study Photodegradation of Acid Orange 7 Using ZnO Waste Batteries
Authors: Hasri  , Sugiarti  , Sadriadi  
Published: August 2019

Abstract
This research aims to determine the ability of ZnO waste batteries to degrade Acid Orange 7. The first, synthesized zinc acetate precursors from Zn waste batteries. Next, synthesized ZnO from the precursor of zinc acetate and impregnated with zeolite to form a ZnO-Zeolite composite used the sol-gel method. Photodegradation test for Acid Orange 7 dye used a time 30, 60, 120, 240, 360 and 480 minute, concentration of 30, 50,75, 100, 150ppm with variations in pH 3, 5, 7, 9 and 11. Measurement of degradation resultsconcentration of Acid Orange 7 dye used a UV-Vis Spectrophotometer at a wavelength of 484.45 nm. The results showed that ZnO-Zeolite composites were able to degrade Acid Orange 7 dyes at pH 7, 480 minute, concentration 50 ppm with a degradation percentage of 94.15%.
Research Design and Identification of the Project Methodology Solutions Using the Finite Element Method
Authors: Bianca Pop Alina , Mihail Țîțu Aurel , Ioan Pop Gheorghe , Ceocea Costel , Țîțu Ștefan 
Published: August 2019

Abstract
The anticipation of the process variables (temperature, cutting forces, and stress distribution) plays an important role in the tool geometry design and cutting conditions optimization. The researchers found that the anticipation of these variables experimentally is costly both from a time requirement and financial point of view. Having this information, the finite element model becomes the most favourable alternative and most useful in all aspects. Existing Empirical models are very useful in demonstrating these matters, but if tests have not been carried out to create these models types, then it brings benefits in the improvement specifically to the process itself. This paper is focus to conduct the research and discover a methodical design solution based on the finite element method. This entails defining the input data used within the research framework, including: application type, finite element analysis, material model, and, of course, choosing the process parameters. After determining the input data, following the completion of the theoretical models of the experiment, respecting the finite element model, the output will take into account the final results of the selected research. In order to obtain optimal solutions and to increase the precision and accuracy of the obtained results, it is necessary to validate this using the experiment.
Characteristics of Wild Orchids in Mallawa Resort at Bantimurung Bulusaraung National Park, South Sulawesi, Indonesia
Authors: Fatmah Hiola Siti , Darma Dirawan Gufran , Wiharto Muhammad , Syamsiah  
Published: August 2019

Abstract
This study aims to determine the characteristics of wild orchids in the area of Resort Mallawa, Bantimurung Bulusaraung National Park. This type of research is descriptive with the exploration method, which is tracking the study area which is known to have a fairly high distribution of wild orchids. Exploration of wild orchids is carried out at 85 distribution points, with an altitude of 432 meters above sea level to 849 m above sea level. The results showed that there were 40 types of orchids, 33 species identified, and 7 species not identified. Based on the growth properties of wild orchids found were dominated by 35 species of epiphytic orchids, while for the type of growth was dominated by 24 species of sympodial orchids. The most found locations of wild orchids are in Mallenreng Hamlet I. The most common species is Trichoglottis geminata. Based on the height of the place, the species that grows at the highest position is Coelogyne sp., while in the lowest position is Dendrobium sp. 1. Based on the visual intensity of light, orchids were found in the shade as many as 5 species, half sheltered as many as 21 species, while in the open as many as 4 species. There are 5 orchid species that can grow in the shade and half shade, 3 species that grow in half shade and open places, and 2 species that can grow in three places. By knowing the presence and diversity of wild orchids in the study area shows that the ecosystem in the area is still quite good, considering that wild orchids are plants that are quite susceptible to interference.
Possibilities of ammonium ions fixation into mixed binders
Authors: Hajzler J , Novotny R , Opravil T , Ptacek P 
Published: August 2019

Abstract
The purpose of this study is to analyze the usability of ammonium ions fixation in mixed binders with the addition of high temperature fly ash. The experiment used high-temperature fly ash from operations in which the secondary flue gas denitrification methods have been implemented, specifically by the method of the selective non-catalytic reduction, known as DeNOx. The fixation of ammonium ions was performed by the addition of sodium hexanitrocobaltate(III). The study examines the influence of addition of cobalt(III) complex compound on the release of ammonia into the environment during the mixing the mixed binder. The released ammonia was quantitatively captured into the acid and subsequently titrated. The effect of cobalt(III) complex compound on the rate of hydration and mechanical properties of the mixed binders was also studied. The influence on the environment in terms of leachability was observed.
The effect of burnt lime addition on hydration of Ultra-high performance cementitious composites
Authors: Novotný R , Bartoníčková E , Kotrla J 
Published: August 2019

Abstract
The paper deals with the burnt lime utilization as a source of calcium ions participated during hydration process of ultra-high performance cementitious composites. These type of ultra-high performance cementitious composites are based on the high content of silica fume that together with calcium ions form the binder phase. In the case of ordinary Portland cement, the hydration during induction period supposed to be too slow for dissolution of required amount of calcium ions necessary for the pozzolanic reaction of presented silica fume. The low addition of the lime should be a sufficient calcium source that allow the starting of the pozzolanic reaction before the acceleration period occurs. The calcium ions content from the beginning of the reaction was controlled by an addition of soft-burnt and dead-burnt lime. Its influence was studied in terms of hydration process by isothermal calorimetry. Based on the experimental data, the hydration reaction mechanism was proposed.
Preparation and properties of Portland limestone cements
Authors: Stanek T , Bohac M , Rybova A , Zezulova A 
Published: August 2019

Abstract
Limestone is a suitable substitute for economically less favourable Portland clinker in Portland blended cements. Limestone in cement not only serves as a very fine filler, but can also act as a reaction component. In this work, the properties of laboratory Portland cements with limestone were studied. The cements were prepared from two limestone types and two clinker types with a graded limestone content of up to 30 wt. %. The limestones had a different CaCO3 content. Clinkers were distinguished by a marked difference in C3A content and hydraulic activity. The effect of limestones on the technological properties of cements, the hydration process and the impact of separate and together grinding of limestone and clinker were studied. In this case, the type of clinker had stronger impact than the type of limestone on the technological parameters. It was also confirmed that a low limestone content has a positive effect on cement hydration.
The effect of zinc, water to binder ratio and silica fume on the hydration and mechanical properties of Portland cement mixtures
Authors: Siler P , Kolarova I , Bednarek J , Janca M , Masilko J , Novotny R , Opravil T 
Published: August 2019

Abstract
The amount of zinc in the clinker or in the secondary raw materials has been increasing in recent years mainly due to the processing of waste materials containing zinc. The aim of this work is to show the effect of zinc on hydration of Portland cement and mechanical properties. These effects were studied by isoperibol calorimetry and mechanical properties testing. Zinc was added to the cement in the form poorly soluble compound ZnO. The concentration of zinc added was chosen as 1wt. percent. The newly formed compounds during hydration were identified by X-ray diffraction method (XRD). Another objective is to show the effect of silica fume (microsilica, SF) as the secondary raw material and water to binder ratio on hydration of cement in the presence of zinc.
Rheological study on influence of hydroxypropyl derivatives of guar gum, cellulose, and chitosan on the properties of natural hydraulic lime pastes
Authors: Zizlavsky T , Vysvaril M , Rovnanikova P 
Published: August 2019

Abstract
Viscosity enhancing admixtures are widely used to improve properties of concrete and ready-mix mortars. Guar gum derivatives and chitosan ethers are reported to have water-retaining effect, which is beneficial for the adhesion of the mixture as well as for the hydratation of hydraulic particles in the binder phase of concrete or natural hydraulic lime (NHL) mortars. Influence of addition of admixtures in doses of 1, 5, and 10‰ of the binder weight has been studied on NHL based pastes with constant water:binder ratio. The measurements were carried out on the Discovery HR-1 rheometer with DIN concentric cylinders geometry. The flow properties and viscoelastic properties were studied on the specified mixtures. Pastes expressed shear-thinning behaviour with thixotropic character of flow curves. Admixture addition caused increase of yield stress, fluidity index and consistency coefficient varying on the amount and type of the admixture. Differences in the effectivity of admixtures were observed, the dosage-dependency of the admixtures varied.
Influence of soil-cement composition on its deformability
Authors: Tracz T , Brasse K , Zdeb T , Bielecka J 
Published: August 2019

Abstract
The paper discusses the results of deformability tests of soil-cement composites made with cohesive and non-cohesive soils. The compositions of the materials analysed were diversified in terms of their cement paste volume fractions and water-cement ratios. The aim of the research was to determine the secant modulus of elasticity in uniaxial compression of soil-cement composites in accordance with the EN 12390-13 standard dedicated to concrete testing. Due to the lower level of strength of the materials in question in comparison with ordinary concrete, nominal stress was lowered and the loading and unloading rates were modified. The number of loading cycles required for the determination of stabilised deformations was verified. The test results obtained and their analysis indicate the significant impact of the type of soil on the deformability of soil-cement composites. It was also found that the deformability of the materials tested is sensitive to changes in their compositions.
Packing density modelling of non-spherical aggreg ates for particle composite design
Authors: Koutny O , Kratochvil J , Drdlova M , Bystrianska E 
Published: August 2019

Abstract
The presented study follows the author’s results of research where 3-parameter packing model for packing density determination was derived and calibrated for multimodal particular system. In this study previously derived model is extended by fourth parameter related to particle shape and its effect on bulk packing density. The model is primary derived for high performance cementitious composite design where compact structure and low binder content is preferred to maximise mechanical properties and durability. The effect of aggregate packing density on mechanical properties of ultra-high performance cementitious composites is investigated, using derived packing model
Effect of curing environment on length changes of alkali-activated slag/cement kiln by-pass dust mixtures
Authors: Bilek V , Kalina L , Simonova H 
Published: August 2019

Abstract
This paper investigates the combination of commonly used blast furnace slag (BFS) and quite non-traditional cement kiln by-pass dust (BD) for the preparation of alkali-activated binder. More specifically, the possibilities of alkali-activated slag (AAS) shrinkage compensation and cracking mitigation using BD were studied. For this purpose, mixtures with ratios of BFS/BD ranging from 100/0 to 60/40 were prepared and cured in different environment, namely autogenous conditions, water curing, air curing and their combinations. The results showed that curing regime is a determinative parameter for performance of the mixtures: BD containing specimens showed a certain expansion during the first days of water curing leading to AAS shrinkage compensation, while in absence of water curing increasing dose of BD increased drying shrinkage significantly.
Development of acoustic insulating materials from recycled textile fiber
Authors: Zach J , Bubenik J , Novak V , Trisko P 
Published: August 2019

Abstract
Nowadays, there is an increasing demand for recycling materials and hence for greater environmental friendliness. The issue of waste management and recycling is a very actual topic in the society of most developed countries. One area where the vast amount of waste is generated every year is the textile industry. Textile waste (old clothing, fashion accessories, car upholstery, home textiles and other textile products) is most often made up of a combination of different types of natural fibers (cotton, silk) and man-made fibers (polyester, viscose). Thanks to the large amount of this waste and recycling technologies available, the secondary textile fibers are an interesting secondary raw material that can be used for the production of thermal and acoustic insulators. The article describes research results in the development of medium and heavy insulating mats usable in vertical constructions and floating floor structures.
Substitution of aeration additive with recycled rubber and its effect on compressive strength and modulus of elasticity
Authors: Chylik R , Trtik T , Fladr J , Seps K 
Published: August 2019

Abstract
The article follows on previous research by authors dealing with the properties of concrete with the addition of recycled rubber. This paper describes the substitution of aeration additives with rubber recycled material and the effect of this substitution on strength and modulus of elasticity. For concrete mixes containing 40 kg/m3 of recycled rubber, the air content of the fresh concrete was measured. Concrete with the same amount of fresh air was made using an aeration additive. Compressive strength and modulus of elasticity were compared.
Proposal of methodology for testing resistance of building materials against mold infestation
Authors: Kukletova I , Chromkova I 
Published: August 2019

Abstract
Molds attack buildings on a broad scale, cause significant damage and carry a number of negative effects on human health. The design of the methodology is based on EN 60068-2-10 “Environmental Impact Testing – Parts 2-10: Tests – Test J and Instructions: Mold Growth” and ČSN 72 4310 “Testing the Resistance of Building Products and Materials against Mold”. However, the first of these standards is intended for electrical industry and the other was published in 1975 with no later revisions. The design of the new methodology aims at simplifying and updating and, last but not least, imitating the success of already implemented methodology for testing resistance to green algae growth. The proposed methodology was successfully verified on both standards and real samples.
Chemical elimination of asbestos materials
Authors: Necasova K , Buchta P 
Published: August 2019

Abstract
Asbestos was a frequently used material in the past, mainly in the construction industry, on account of its excellent thermal and chemical resistance. Nowadays, all uses, handling and disposal of asbestos materials are subject to strict legislation due to health hazard. This work is a research of an efficient chemical way to decompose these materials with the lowest energy costs possible so that the method could compete with patented thermal decomposition and other currently common methods. Decompositions were performed at room temperature with acids, namely hydrochloric, sulfuric, phosphoric, acetic and oxalic acid and the results were evaluated based on mass analysis. Asbestos rope and asbestos-cement roof tile were used as samples. From the experiments carried out, the best decomposing agent was hydrochloric acid for the rope sample and acid mixture (hydrochloric and acetic acid in a 1:1 ratio). for the roof tile sample