scholarly journals An Attempt of Geopolymer Synthesis from Construction Waste

2013 ◽  
Vol 28 ◽  
pp. 29-33 ◽  
Author(s):  
Vinay Kumar Jha ◽  
Anupama Tuladhar
Keyword(s):  
Chemical Society ◽  
Raw Material ◽  
Alkali Concentration ◽  
Kathmandu Valley ◽  
Curing Time ◽  
Huge Amount ◽  
Construction Waste ◽  
Alumino Silicate ◽  
New Buildings

Recently, the demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak which in turn generates a huge amount of construction waste. This construction waste is rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from construction waste using NaOH and Na2SiO3 as activators. Some parameters like alkali concentration, ratio of Na2SiO3 to construction waste and curing time have been varied in order to improve the quality of geopolymeric product. The results obtained revealed the maximum compressive strength of 7.3 MPa at the ratio of sodium silicate to construction waste of 0.5 (w/w) on 15 days curing time at 40ºC temperature. DOI: http://dx.doi.org/10.3126/jncs.v28i0.8038Journal of Nepal Chemical Society Vol.28, 2011 Page 29-33 Uploaded date: March 6, 2013

scholarly journals Synthesis of Geopolymer from Inorganic Construction Waste

2013 ◽  
Vol 30 ◽  
pp. 45-51 ◽  
Author(s):  
Arbind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Compressive Strength ◽  
Coal Fly Ash ◽  
Chemical Society ◽  
Raw Material ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Mass Ratio ◽  
Construction Waste ◽  
Alumino Silicate

Recently, the demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak which in turn generates a huge amount of construction waste. There are two major types of construction wastes which are burden for disposal namely cement-sand-waste (CSW) and the coal fly ash (CFA). These construction wastes are rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from CSW and CFA using NaOH-KOH and Na2SiO3 as activators. Some parameters like alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process has been carried out using 3-8M KOH/NaOH solutions, Na2SiO3 to CFA and CSW mass ratio of 0.25-2.00 and curing time variation from 5-28 days. The curing temperature was fixed at 40ºC in all the cases. 6M NaOH and 7M KOH solutions were found appropriate alkali concentrations while the ratio of sodium silicate to CSW and CFA of 0.5 and 1.75 respectively were found suitable mass ratio for the process of geopolymer synthesis. The maximum compressive strength of only 7.3 MPa after 15 days curing time with CSW raw material was achieved while with CFA, the compressive strength was found to be 41.9 MPa with increasing the curing time up to 28 days.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9334Journal of Nepal Chemical Society Vol. 30, 2012 Page:  45-51 Uploaded date: 12/16/2013    

scholarly journals Comparative Study of the Geopolymers Synthesized from Various Types of Construction Wastes

2013 ◽  
Vol 14 (1) ◽  
pp. 81-86
Author(s):  
Arvind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Building Materials ◽  
Alkali Concentration ◽  
Huge Amount ◽  
Alkali Silicate ◽  
Wide Range ◽  
Alumino Silicate ◽  
Cement Mixture ◽  
New Buildings ◽  
Brick Dust

Demolition of old houses and construction of new buildings are in peak in urban sectors which generate a huge amount of construction wastes. These wastes are rich source of alumino-silicate. Geopolymerization can transform a wide range of alumino-silicate materials into building materials with excellent physicochemical properties. Thus, geopolymers have been synthesized from construction wastes such as sand-cement-mixture (SCM), concrete mixture (CM), brick dust (BD), etc using alkali and alkali-silicate as activators. Parameters like alkali concentration (for dissolution of alumino-silicate), ratio of alkali-silicate to construction wastes and curing time were varied to improve the quality of geopolymeric products. The maximum compressive strengths of geopolymeric products obtained from BD, SCM and CM were 60.0, 47.0 and 45.5 MPa respectively. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 81-86 DOI: http://dx.doi.org/10.3126/njst.v14i1.8926

scholarly journals Synthesis of Geopolymer from Coal Fly Ash

2013 ◽  
Vol 30 ◽  
pp. 24-28
Author(s):  
Vinay Kumar Jha ◽  
Gautam Prasad Budhamagar
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Chemical Society ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Naoh Solution ◽  
Maximum Compressive Strength

In the present work, geopolymers have been synthesized from coal fly ash (CFA) using NaOH and Na2SiO3 as activators. Some parameters like alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process has been performed using 3-8M NaOH solutions, Na2SiO3 to CFA mass ratios of 0.25-1.25 and curing time variation from 5-15 days. The curing temperature was fixed at 40ºC in all cases. In the variation of NaOH concentration, the maximum compressive strength of 2.3 MPa was obtained with CFA treated with 6M NaOH solution. Similarly during the variation of amount of Na2SiO3, the maximum compressive strength of 17.6 MPa was obtained with Na2SiO3 to CFA mass ratio of 1.25. Furthermore, the compressive strength was found increasing up to 20.3 MPa with increasing curing time.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9331Journal of Nepal Chemical Society Vol. 30, 2012 Page:  24-28 Uploaded date: 12/16/2013 

scholarly journals A Laboratory Scale Synthesis of Geopolymer from Locally Available Coal Fly Ash from Brick Industry

2013 ◽  
Vol 29 ◽  
pp. 18-23
Author(s):  
Rishi Babu Bhandari ◽  
Arvind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Time Variation ◽  
Coal Fly Ash ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Mass Ratio ◽  
Maximum Compressive Strength

In this work, geopolymers have been synthesized from coal fly ash (CFA) using KOH and Na2SiO3 as activators. Some parameters such as alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process was carried out using 3-8 M KOH solutions, Na2SiO3 to CFA mass ratio of 0.25-2.00 and curing time variation from 6-28 days. The curing temperature was fixed at 40°C in all the cases. During the variation of KOH concentration, the maximum compressive strength of 6.62 MPa was obtained with CFA treated with 7 M KOH solution. Similarly, with the variation of the mass ratio of Na2SiO3 to CFA, the maximum compressive strength of 28.1 MPa was obtained with Na2SiO3 to CFA mass ratio of 1.75. Furthermore, the compressive strength was found to be increased with increasing curing time and 41.9 MPa was achieved with 28 days of curing time. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9232Journal of Nepal Chemical SocietyVol. 29, 2012Page: 18-23Uploaded date : 12/3/2013 

scholarly journals Mapeamento da deposição irregular dos resíduos provenientes da construção civil na cidade de Mossoró-RN

2016 ◽  
Vol 11 (3) ◽  
pp. 86
Author(s):  
Giordanio Bruno Silva Oliveira ◽  
Ellen Ramona de Almeida Correia Brito ◽  
Luan Alves Lima ◽  
Leonardo Vieira de Sousa ◽  
Frnacisco De Assis de Oliveira
Keyword(s):  
Public Health ◽  
Natural Resources ◽  
Construction Industry ◽  
Environmental Degradation ◽  
Residential Areas ◽  
Huge Amount ◽  
Construction Waste ◽  
Quality Of Living ◽  
The City

<p class="CorpodoresumoIVCBM">A construção civil tem sido considerada uma das mais importantes atividades para o desenvolvimento da sociedade, porém é uma atividade que causa impactos ambientais, pois utiliza recursos naturais, modifica o meio ambiente e gera um grande volume de resíduos. Nota-se que as atividades ligadas à construção civil no município de Mossoró-RN, são responsáveis por gerar uma quantidade considerável de resíduos de construção civil (RCC), que na maioria das vezes, são depositados em locais irregulares, por não haver na cidade um local específico para esse fim. Esses resíduos constituem um grave problema, tanto para o meio ambiente quanto para qualidade de vida da população. A pesquisa foi realizada com o objetivo de mapear áreas de depósito irregular de resíduos provenientes da construção civil na cidade de Mossoró-RN. Foi realizada a demarcação dos pontos de acordo com a localização do despejo dos resíduos, com a finalidade de identificar e indicar sua localização dentro da zona urbana de Mossoró-RN. No presente estudo, foi possível identificar 11 pontos de deposição irregular de resíduos provenientes da construção civil, espalhados em diferentes locais da cidade, alguns situando-se próximo de áreas residenciais, o que caracteriza sérios riscos à saúde pública, e outros dispostos próximos de cursos d’água, o que provoca degradação do meio ambiente.</p><p class="western" align="center"><strong><em>Mapping of irregular dumping of solid waste from construction industry at Mossoró-RN, Brazil</em></strong><em></em></p><p><strong>Abstract: </strong>Construction industry has been considered one of the most important activities regarding to society development, however it causes environmental impacts, because it uses natural resources, modifies the environment and generate a huge amount of waste. It was observed that in Mossoró, RN, Brazil, a large amount of construction waste is often deposed in unauthorized sites because the municipality does not provide a specific site for this purpose. Such waste is a serious problem for the environment and for the people’s quality of living. In this context a research was carried out with the objective of mapping sites of non authorized deposition of construction waste in the city of Mossoró, RN, Brazil. With this intent, points were georeferenced according to the location of deposition of waste, with the objective of identifying and indicating its location inside the urban zone of the city. At the end of the study were identified eleven sites of unauthorized deposition of construction waste, all over the city, some of which were located near residential areas, what poses a serious hazard to public health, while other sites were near water streams, what promote environmental degradation.</p>

TECHNOLOGICAL ASPECTS OF HIGH QUALITY RAW MATERIAL OBTAINING FOR PECTIN PRODUCTION

1970 ◽  
pp. 47-50
Author(s):  
I. A. Ilina ◽  
I. A. Machneva ◽  
E. S. Bakun
Keyword(s):  
Raw Materials ◽  
Thermal Characteristics ◽  
Environmental Safety ◽  
Raw Material ◽  
High Quality ◽  
Temperature Conductivity ◽  
Drying Temperature ◽  
Plant Raw Materials ◽  
Gel Forming Ability

  The article is devoted to the study of the chemical composition, physical and thermal-pfysical characteristics of damp apple pomaces and the identifying patterns of influence of drying temperature the functional composition and gel-forming ability of pectin. The research is aimed at obtaining initial data for the subsequent calculation of the main technological, hydro-mechanical, thermal, structural and economic characteristics of devices for drying the plant raw materials, ensuring the environmental safety and high quality of pectin-containing raw materials, the reducing heat and energy costs. As a result of the study of the thermal characteristics of apple pomaces, the critical points (temperature conductivity – 16.5 x 10-8 m2/s, thermal conductivity – 0.28 W/m K, heat capacity – 1627 j/(kg K)) at a humidity of 56 % are determined, which characterizing the transition from the extraction of weakly bound moisture to the extraction of moisture with strong bonds (colloidal, adsorption). It was found that the pomaces obtained from apples of late ripening have a higher content of solids (21-23 %), soluble pectin and protopectin (2.5-4.5 %). Dried pomaces obtained from apple varieties of late ripening contain up to 25 % pectin, which allow us to recommend them as a source of raw materials for the production of pectin. The optimum modes of preliminary washing of raw materials are offered, allowing to the remove the ballast substances as much as possible. It is established that when the drying temperature increases, the destructive processes are catalyzed: the strength of the pectin jelly and the uronide component and the degree of pectin esterification are reduced. The optimum drying temperature of damp apple pomaces is 80 0C, at which the quality of pectin extracted from the dried raw materials is maintained as much as possible. It is shown that the most effective for the pectin production is a fraction with a particle size of 3-5 mm, which allow us to extract up to 71 % of pectin from raw materials.

Physico-Chemical Aspects of the Influence of Raw Material Components on the Quality of Ceramic Brick

2019 ◽  
Vol 777 (12) ◽  
pp. 37-42
Author(s):  
G.Yu. SHAGIGALIN ◽  
◽  
P.A. FEDOROV ◽  
L.N. LOMAKINA ◽  
◽  
...  
Keyword(s):  
Raw Material ◽  
Ceramic Brick ◽  
Physico Chemical

scholarly journals A Methodology Based on FT-IR Data Combined with Random Forest Model to Generate Spectralprints for the Characterization of High-Quality Vinegars

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1411
Author(s):  
José Luis P. Calle ◽  
Marta Ferreiro-González ◽  
Ana Ruiz-Rodríguez ◽  
Gerardo F. Barbero ◽  
José Á. Álvarez ◽  
...  
Keyword(s):  
Random Forest ◽  
Raw Materials ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Raw Material ◽  
Support Vector ◽  
Protected Designation Of Origin ◽  
Ft Ir

Sherry wine vinegar is a Spanish gourmet product under Protected Designation of Origin (PDO). Before a vinegar can be labeled as Sherry vinegar, the product must meet certain requirements as established by its PDO, which, in this case, means that it has been produced following the traditional solera and criadera ageing system. The quality of the vinegar is determined by many factors such as the raw material, the acetification process or the aging system. For this reason, mainly producers, but also consumers, would benefit from the employment of effective analytical tools that allow precisely determining the origin and quality of vinegar. In the present study, a total of 48 Sherry vinegar samples manufactured from three different starting wines (Palomino Fino, Moscatel, and Pedro Ximénez wine) were analyzed by Fourier-transform infrared (FT-IR) spectroscopy. The spectroscopic data were combined with unsupervised exploratory techniques such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as other nonparametric supervised techniques, namely, support vector machine (SVM) and random forest (RF), for the characterization of the samples. The HCA and PCA results present a clear grouping trend of the vinegar samples according to their raw materials. SVM in combination with leave-one-out cross-validation (LOOCV) successfully classified 100% of the samples, according to the type of wine used for their production. The RF method allowed selecting the most important variables to develop the characteristic fingerprint (“spectralprint”) of the vinegar samples according to their starting wine. Furthermore, the RF model reached 100% accuracy for both LOOCV and out-of-bag (OOB) sets.

scholarly journals Effect of carbon anode production parameters on anode cracking

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Salah Amrani ◽  
Duygu Kocaefe ◽  
Yasar Kocaefe ◽  
Dipankar Bhattacharyay ◽  
Mohamed Bouazara ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Crack Density ◽  
Raw Material ◽  
Carbon Anode ◽  
Know How ◽  
Production Parameters ◽  
Environmental Emissions ◽  
Carbon Anodes ◽  
Tomographic Analysis

AbstractCarbon anodes are used in the electrolytic production of aluminum. The quality of anodes is directly related to the production cost, carbon and energy consumption, and environmental emissions. It is desired that the anodes have high density, low porosity/cracks, low electrical resistivity as well as low air and CO2 reactivities. Low resistivity of anodes reduces energy required to produce aluminum during electrolysis. The presence of cracks and pores increases the anode electrical resistivity. Therefore, it is important to know how and when the pores and cracks form during the anode production so that the necessary actions could be taken to prevent their formation. A study was carried out to investigate the effect of different anode production parameters such as anode composition, type of raw material used, time and top-former bellow pressure of vibro-compactor, green anode cooling medium, and heating rate used during baking on the crack formation. The anodes are fabricated at the carbon laboratory of University of Quebec at Chicoutimi (UQAC) and characterized by measuring their properties (density, electrical resistivity, and surface crack density). The anode properties, hence the anode quality, were correlated with the anode production parameters. Also, their tomographic analysis was carried out to visualize and quantify the internal cracks. Graphical abstract

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