To see the other types of publications on this topic, follow the link: Activator method.
Journal articles on the topic 'Activator method'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Activator method.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Evans, Sara K., David P. Aiello, and Michael R. Green. "Fluorescence resonance energy transfer as a method for dissecting in vivo mechanisms of transcriptional activation." Biochemical Society Symposia 73 (January 1, 2006): 217–24. http://dx.doi.org/10.1042/bss0730217.
Full textAbstract:
The first step in transcriptional activation of protein-coding genes involves the assembly on the promoter of a large PIC (pre-initiation complex) comprising RNA polymerase II and a suite of general transcription factors. Transcription is greatly enhanced by the action of promoter-specific activator proteins (activators) that function, at least in part, by increasing PIC formation. Activator-mediated stimulation of PIC assembly is thought to result from a direct interaction between the activator and one or more components of the transcription machinery, termed the ‘target’. The unambiguous identification of direct, physiologically relevant in vivo targets of activators has been a considerable challenge in the transcription field. The major obstacle has been the lack appropriate experimental methods to measure direct interactions with activators in vivo. The development of spectral variants of green fluorescent protein has made it possible to perform FRET (fluorescence resonance energy transfer) analysis in living cells, thereby allowing the detection of direct protein–protein interactions in vivo. Here we discuss how FRET can be used to identify activator targets and to dissect in vivo mechanisms of transcriptional activation.
2
Ruslinda, Yenni, Rizki Aziz, Larasati Sekar Arum, and Novita Sari. "The Effect of Activator Addition to the Compost with Biopore Infiltration Hole (BIH) Method." Jurnal Ilmu Lingkungan 19, no. 1 (April 28, 2021): 53–59. http://dx.doi.org/10.14710/jil.19.1.53-59.
Full textAbstract:
The composition of organic waste reaches 59% of the total municipal solid waste in Indonesia. One way to process organic waste is composting by utilizing microorganisms to break down waste into compost. Naturally, the composting process took a long time but can be accelerated by adding microorganisms to the activator. This study analyzes the quality and quantity of compost using the Biopore Infiltration Hole (BIH) method with activator addition. Composting was duplicated in the yard area with clay soil type and water infiltration rate of 0,3 cm/hour. The BIH was made in a 10 cm diameter, a 100 cm depth, and the distance between the holes was 50 cm. Composting variations consist of variations in the composition of the raw materials and the activators' uses. Variations in the raw material composition consisted of 100% yard waste, 100% food waste, 50% yard waste and 50% food waste, and 70% food waste and 30% yard waste. In contrast, the activator variations consisted of no activator, EM4 activator, and Stardec activator. Compost analysis consists of maturity, quality of physical and macro elements, and quantity of compost. The results showed that all variations of composting had met the standard of maturity and quality of physical and macro elements according to SNI 19-7030-2004. The addition of activator affected composting time and compost quantity. The composting time in BIH with activator ranges from 41-60 days. In BIH without activator ranges from 65-75 days, there was a reduction in composting time by 15-25 days with the activator addition. However, the activator addition caused reducing the compost quantity by 10-20%. The selection of compost variations by scoring results in compost with a composition of 50% yard waste and 50% food waste and the addition of Stardec activators was the best variation in terms of compost maturity, quality, and quantity.
3
Sidelnikova, N. S. "Charge state of the activator in Ti:sapphire crystals grown by HDC method." Functional materials 22, no. 4 (December 15, 2015): 461–69. http://dx.doi.org/10.15407/fm22.04.461.
Full text
4
Kessels, H., S. Béguin, R. Wagenvoord, and H. C. Hemker. "A Method for Measuring Activated Factor VIII in Plasma." Thrombosis and Haemostasis 66, no. 04 (1991): 430–34. http://dx.doi.org/10.1055/s-0038-1646433.
Full textAbstract:
SummaryA method is described which enables a quantitative measurement of the concentration of activated factor VIII (VIIIa) in plasma. Based on the ability of factor VIIIa to accelerate the activation of factor X by factor IXa, phospholipid and calcium ions, the course of factor X activation in time is measured using a chromogenic substrate. Free factor Xa is able to activate non-activated factor VIII present in a plasma sample, which increases the factor X activation velocity, and thus disturbs the measurement of factor VIIIa. Furthermore, factor Xa was found to be inactivated by serine protease inhibitors from the plasma sample. By adding surplus chromogenic substrate these reactions of factor Xa are inhibited and at the same time the rate of substrate conversion is a measure of the amount of factor Xa present. Factor X activation and amidolysis of chromogenic substrate then take place simultaneously. It is shown that under proper conditions the factor X activation velocity is linearly proportional to the factor VIIIa concentration. This causes the optical density to increase as a parabolic function of time. The concentration of factor VIIIa can be obtained from the quadratic coefficient of the equation describing the parabola. The method is specific for factor VIIIa in that the extrinsic factor X activator is shown to have no influence on the measurement of factor VIIIa in thromboplastin activated plasma. We conclude that a sensitive and reliable method for assessing factor VIIIa concentrations in plasma has been developed on the basis of simultaneous inhibition and measurement of factor Xa by a high concentration of chromogenic substrate.
5
Kim, Taewan, and Choonghyun Kang. "Investigation of the Effect of Mixing Time on the Mechanical Properties of Alkali-Activated Cement Mixed with Fly Ash and Slag." Materials 14, no. 9 (April 29, 2021): 2301. http://dx.doi.org/10.3390/ma14092301.
Full textAbstract:
This is an experiment on the effect of mixing time for alkali-activated cement (AAC) using a binder mixed with ground granulated blast furnace slag (slag) and fly ash (FA) in a ratio of 1:1 on the mechanical properties. The mixing method of ASTM C305 was used as the basic mixing method, and the following mixing method was changed. Simply adding the same mixing time and procedure, the difference in the order of mixing slag and FA, and controlling the amount of activator and mixed water were considered. As a result of the experiment, the addition of the same mixing time and procedure, pre-injection of slag, and high-alkali mixed water in which half of the activator and mixing water were mixed showed the highest mechanical properties and a dense pore structure. As a result, the design of a blending method that can promote the activation action of slag rather than FA at room temperature was effective in improving the mechanical properties of AAC. In addition, these blending factors showed a clearer effect as the concentration of the activator increased. Through the results of this experiment, it was shown that high-temperature curing, high fineness of the binder, or even changing the setting of the mixing method without the use of excessive activators can lead to an improvement of mechanical properties.
6
Nekrasova, Larisa P., Rufina I. Mikhailova, and Irina N. Ryzhova. "Impact of the electrochemical treatment on physical and chemical properties of water activated in various devices using electrochemical activation technology." Hygiene and sanitation 99, no. 9 (October 20, 2020): 904–10. http://dx.doi.org/10.47470/0016-9900-2020-99-9-904-910.
Full textAbstract:
Introduction. Currently, there are various technologies for water treatment and water purification, including ozonation of water, water treatment with UV radiation, ion exchange, magnetization. Electrochemical treatment of water by direct electric current, in which activated water is formed, characterized by many anomalous properties, is a modern approach to water treatment and water treatment. Purpose of the study. The study of the physicochemical properties of water-activated in devices of different manufacturers with different designs. Material and methods. To activate the water, activators were used: AP-1, Melesta, Zdrava, the filter of electrochemical water purification “ Izumrud”. The activity of hydrogen ions and the redox potential of water were measured using an Ecotest-120 ionomer with a switch. To measure the electrical conductivity of the solutions, an Expert-002 conductometer was used. Free chlorine was determined by the photocolorimetric method on a Spectroquant Multy colorimeter. Antioxidant activity was determined spectrophotometrically using a mediator system of potassium ferro-ferricyanide. Results. Chloride ions make a decisive contribution to the change in the physicochemical characteristics of anolyte upon activation of water. Sulfates and bicarbonates do not affect the prooxidant activity of the anolyte. The relaxation of catholytes obtained in membrane activators proceeds by a gradual increase in ORP, while the relaxation of activated water in the Zdrava diaphragmless activator proceeds in an oscillatory mode and is characterized by sharp changes in ORP. Anolytes are stable over time and slightly change the pH and ORP during storage. The activation of certain types of water in a diaphragmless activator does not lead to a decrease in the ORP, but its significant growth. Conclusion. Electrochemically activated water is a general term that hides in each case an unknown substance with an unpredictable effect. The use of standard devices even when using the same water sample, as a rule, leads to different physicochemical characteristics of activated water. When using different types of water, physicochemical characteristics differ significantly. The use of electrochemically activated water is unsafe.
7
Zhurilova, Maya A., Igor A. Yanilkin, Elena A. Kiseleva, Irina N. Atamanyuk, and Evgeniy I. Shkolnikov. "NANOPOROUS ACTIVATED CARBONS FOR SUPER CAPACITORS WITH AQUEOUS AND ORGANIC ELECTROLYTES." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 4 (May 12, 2017): 82. http://dx.doi.org/10.6060/tcct.2017604.5520.
Full textAbstract:
An urgent task is to develop new methods of obtaining porous carbon materials with required complex of properties of cheap raw materials, for example, wastes of mechanical and chemical wood processing. This article deals with the subject of production of activated carbon for supercapacitors with different electrolytes. Activated carbons produced from two wood species, birch and alder, were compared. For both carbons identical dependences of the porous structure and electrochemical parameters of the carbons on activation conditions were determined in a wide range of activation parameters (temperature, alkali/carbon mass ratio). The work was done on the basis of commercial coals of alder. The correlations between the activation parameters of coal (temperature of activation and the relationship of the activator/raw materials), porous structure and functional parameters of capacitors were established. It was established that the acceptable value of the temperature of activation for aqueous electrolyte was 600 °C, and the ratio of activator/raw = 1.25, for organic – 600 °C, the ratio of the activator/raw = 2. A comprehensive study of carbon properties was conducted including a detailed study of the porous structure by the method of limited evaporation and electrochemical parameters of activated carbon in the composition of the supercapacitors. Assumptions were made on the features of formation of porous structure of activated carbons obtained by thermo-chemical synthesis using alkali as an activator, and on the influence of synthesis parameters on the electrochemical characteristics of the supercapacitors.Forcitation:Zhurilova M.A., Yanilkin I.V., Kiseleva E.A., Atamanyuk I.N., Shkolnikov E.I. Nanoporous activated carbons for super capacitors with aqueous and organic electrolytes. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 82-87.
8
Mumpuni, Irna Diah, Mamay Maslahat, and Devy Susanty. "Activation of oil palm empty bunches with hydrochloride acid & phosphoric acid and characterization based SNI No. 06-3730-1995." JURNAL SAINS NATURAL 11, no. 1 (April 29, 2021): 16. http://dx.doi.org/10.31938/jsn.v11i1.291.
Full textAbstract:
Activated carbon is a solid product resulting from carbonization and activation of lignocellulosic biomass by several methods and activators. Each activator can produce different characteristics of activated carbon. The activated carbon of Oil Palm Empty Fruit Bunches (OPEFB) is processed from Empty Fruit Bunches (EFB) waste, which is quite abundant in Indonesia. The purpose of this study was to determine the characteristics of OPEFB carbon that had been chemically activated using hydrochloric acid (HCl) and phosphoric acid (H3PO4) based on the Indonesian National Standard (SNI) No. 06 - 3730 - 1995. The research method consisted of the process of carbonization of OPEFB using a pyrolysis device at 400oC for 6 hours; activation of carbon with activator HCl and H3PO4 at various activator concentrations; characterization of activated carbon on the parameters of moisture content, ash content, absorption of iodine, and absorption of methylene blue. The results showed that the 0.5000 M HCl was the best activator that produced the quality of OPEFB activated carbon according to SNI 06 - 3730 - 1995 on parameters of moisture content, ash content and absorption of iodine.Keywords: Activated Carbon, Iodine Absorption, Oil Palm Empty Fruit BunchesABSTRAKAktivasi karbon tandan kosong kelapa sawit dengan asam klorida dan asam fosfat serta uji karakterisasi berdasarkan SNI No. 06–3730–1995Karbon aktif merupakan produk padatan yang dihasilkan dari karbonisasi dan aktivasi biomassa lignoselulosa dengan beberapa metode dan aktivator. Masing-masing aktivator dapat menghasilkan karakteristik karbon aktif yang berbeda. Karbon aktif Tandan Kosong Kelapa Sawit (TKKS) diolah dari limbah TKKS yang keberadaannya cukup melimpah di Indonesia. Tujuan penelitian ini adalah mengetahui karakteristik karbon TKKS yang telah diaktivasi secara kimia menggunakan aktivator asam klorida (HCl) dan asam fosfat (H3PO4) berdasarkan Standar Nasional Indonesia (SNI) No. 06 – 3730 – 1995. Metode penelitian terdiri atas proses karbonisasi TKKS menggunakan alat pirolisis pada suhu 400 ℃ selama 6 jam; aktivasi karbon dengan aktivator HCl dan H3PO4 pada berbagai konsentrasi aktivator; serta karakterisasi karbon aktif pada parameter kadar air dan abu, daya jerap terhadap iod serta daya jerap terhadap biru metilen. Hasil penelitian menunjukkan bahwa HCl 0,5 M merupakan aktivator terbaik dan karbon aktif yang dihasilkan memiliki karakteristik yang sesuai dengan SNI 06 – 3730 – 1995 pada parameter kadar air dan abu serta daya jerap terhadap iod.Kata kunci: Daya Jerap Iod, Karbon Aktif, Tandan Kosong Kelapa Sawit
9
Yuan, Chun Hua. "Preparation and Character of Inorganic Polymeric Coagulates from Fly Ash by Activation Method." Applied Mechanics and Materials 401-403 (September 2013): 679–82. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.679.
Full textAbstract:
Using the main raw material of fly ash, metal scrap and waste industrial acid, with the activating method of specific self-activator ,can prepare poly-ferric-aluminum-silicate(PFAS) flocculant of inorganic polymeric coagulates. Specific activator can effectively open the Si-Al bond in the fly-ash, greatly enhance the leaching rate of each element by adding a special activator (M), the added amount of M: SiO2 = 1:3, activation time of 1 hour, activation temperature to 900 °C, get the original product, on 65 °C with turbid acid to stir and leach, leaching time is 2 hours, get the best rate of leaching. By Controlling Molar ratio of (Al + Fe) and Si 1:1, Silicic acid polymerization pH 1.7, by choosing the appropriate amounts of flocculants and flocculation time ,can get the very good flocculation function, the light transmission rate of the handling-water may amount to more than 92.7%.
10
de Maat, Steven, Sanne van Dooremalen, Philip G. Groot, and Coen Maas. "A nanobody-based method for tracking factor XII activation in plasma." Thrombosis and Haemostasis 110, no. 09 (2013): 458–68. http://dx.doi.org/10.1160/th12-11-0792.
Full textAbstract:
SummaryThe physiological role of the plasma protein factor XII (FXII), as well as its involvement in human pathology, is poorly understood. While FXII is implicated in thrombotic pathology as a coagulation factor, it can contribute to inflammatory conditions without triggering coagulation. We recently generated nanobodies against the catalytic domain of activated FXII (FXIIa). Here, we describe two of these nanobodies, A10 and B7, both of which do not recognise FXII. Nanobody A10 recognises the catalytic domain of purified β-FXIIa (80 kDa), but not that of purified α-FXIIa (28 kDa), whereas nanobody B7 recognises both. This suggests minute differences in the catalytic domain between these isoforms of FXIIa. The detection of FXIIa by these nanobodies in plasma can become compromised through inactivation by serine protease inhibitors. This effect can be efficiently countered through the addition of the small-molecular protease inhibitor PPACK. Finally, we show that our nanobody-based assays in vitro distinguish various activation products of FXII that differ with the type of activator present: whereas procoagulant activators solely trigger the formation of a species that is captured by B7, proinflammatory activators first generate a species that is recognised by B7, which is later converted into a species that is recognised by A10. These findings suggest that a progressive proteolysis of FXIIa results in the generation a non-procoagulant form of FXIIa, whereas retention of intermediate forms triggers coagulation. Moreover, our findings indicate the development of nanobodies against activated enzymes offers improved opportunities to investigate their contribution to health and disease.
11
Yao, Wen Juan, Lei Fan, and Guang Yan Liu. "Properties of Alkali-Activated Waste Glass-Cement Cementitious Materials." Materials Science Forum 926 (July 2018): 134–39. http://dx.doi.org/10.4028/www.scientific.net/msf.926.134.
Full textAbstract:
The hydration products, microstructure and development principle of intensity of cement-glass powder cementitious materials acted in alkali and activation effect of chemical activation on waste glass powder were investigated. The principle of intensity and effect of curing time was analyzed by changing alkali type, content of alkali, incorporation of glass powder, incorporation method of activators and other factor. The result shows that: sodium carbonate and sodium silicate can single stimulate activity of glass powder under a certain condition, the activated effect of combined admixture is superior to the effect on single-doped activator, under the action of an excitation agent, surface hydrolysis of glass powder takes place on the glass body first and the hydration products occurs, The pozzolanic reactivity of glass powder increases gradually and generated a larger amount of hydration products，which has lapped and interlocked growth between each other，and form the compact hardened matrix. In addiation, the shorting of curing time is used by activator, the result may be lead to initial curing and against in engineering construction.
12
Aldila, Herman, Megiyo Megiyo, Fitri Afriani, and Yuant Tiandho. "ANALYSIS OF INFLUENCE OF ACTIVATOR CONCENTRATION ON CHARACTERISTICS OF ACTIVATED CARBON FROM KETAPANG SHELL (Terminalia Catappa) BASED ON IMAGE PROCESSING METHOD." Jurnal Geliga Sains: Jurnal Pendidikan Fisika 6, no. 1 (August 13, 2018): 1. http://dx.doi.org/10.31258/jgs.6.1.1-8.
Full textAbstract:
Activated carbon from ketapang shell (Terminalia Catappa) has been successfully synthesized usingdehydration-carbonization method. Activated carbon was conducted by immersing with sulphuric acid andfollowed by carbonization at 600oC for 2 hours. Pore characteristics were determined using imageprocessingmethods of activated carbon micrographs based on parameters of area and caliper length. Fromthe area approximation method obtained that the maximum pore size estimate was 5,69 μm at activatorconcentration 3% while the minimum was 4,88 μm at activator concentration 11% activator concentrationrespectively. At the other hands, caliper length approximation method obtained estimation of maximum poresize that was equal to 9,09 μm at activator concentration 3% and its minimum that was equal to 7,35 μm atactivator concentration 7%. The porosity of the activated carbon from ketapang shell increased with theincrease of sulfuric acid concentration and the highest value reached 24.96%.
13
Kwiatkowski, Mirosław, and Xin Hu. "Analysis of the Effect of Conditions of Preparation of Nitrogen-Doped Activated Carbons Derived from Lotus Leaves by Activation with Sodium Amide on the Formation of Their Porous Structure." Materials 14, no. 6 (March 21, 2021): 1540. http://dx.doi.org/10.3390/ma14061540.
Full textAbstract:
This paper presents results of the analysis of the impact of activation temperature and mass ratio of activator to carbonized precursor R on the porous structure of nitrogen-doped activated carbons derived from lotus leaves by carbonization and chemical activation with sodium amide NaNH2. The analyses were carried out via the new numerical clustering-based adsorption analysis (LBET) method applied to nitrogen adsorption isotherms at −195.8 °C. On the basis of the results obtained it was shown that the amount of activator, as compared to activation temperatures, has a significantly greater influence on the formation of the porous structure of activated carbons. As shown in the study, the optimum values of the porous structure parameters are obtained for a mass ratio of R = 2. At a mass ratio of R = 3, a significant decrease in the values of the porous structure parameters was observed, indicating uncontrolled wall firing between adjacent micropores. The conducted analyses confirmed the validity of the new numerical clustering-based adsorption analysis (LBET) method, as it turned out that nitrogen-doped activated carbons prepared from lotus leaves are characterized by a high share of micropores and a significant degree of surface heterogeneity in most of the samples studied, which may, to some extent, undermine the reliability of the results obtained using classical methods of structure analysis that assume only a homogeneous pore structure.
14
Anggarini, Ufafa, Eva Agustina, and Nurul Widiastuti. "Crystal Phase and Surface Morphology of Zeolite-Y Templated Carbon with K2CO3 and ZnCl2 Activation." Indonesian Journal of Chemistry 15, no. 3 (November 12, 2015): 315–18. http://dx.doi.org/10.22146/ijc.21201.
Full textAbstract:
Zeolite-Y templated carbon (ZTC) has been activated with K2CO3 and ZnCl2. This research aims to compare the characteristics of ZTC with K2CO3 and ZnCl2 activation. ZTC was synthesized via impregnation method followed by carbonization. In this research, activation process was conducted at variation of activator/carbon weight ratio of 1 and 1.50. The activation was carried out by heating up impregnated carbon at 800 °C for 1 h followed by washing to remove inorganic salt. XRD and SEM results indicate that the use of different activator produce ZTC with varied structure and morphology. Diffractogram results showed that the graphitic peak decreased due to K2CO3 activation, whereas graphitic peak increased owing to ZnCl2 activation. Decreasing the graphitic peak indicates that ZTCs have higher pore structure formation. In addition, surface formation of ZTC activated by K2CO3 was higher than by ZnCl2 activation. The higher pore structure formation means the amount of carbon deposited on external surface material was decreased.
15
Bakti, Andi Ikhtiar, and Paulus Lobo Gareso. "Characterization of Active Carbon Prepared from Coconuts Shells using FTIR, XRD and SEM Techniques." Jurnal Ilmiah Pendidikan Fisika Al-Biruni 7, no. 1 (April 29, 2018): 33. http://dx.doi.org/10.24042/jipfalbiruni.v7i1.2459.
Full textAbstract:
Activated carbon is produced from coconut shells through physical and chemical activation. With pyrolysis method, the optimum activation temperature for physics activation is 600oC, and for chemical, activation is to soak it in activator ZnCl2 10% and Na2Ca3 10%. Activated carbon was analyzed by Fourier Transformation Infrared (FTIR) and X-ray Diffraction (XRD) methods. The FTIR result showed that the coconut shells succeeds in becoming carbon. The XRD results confirm the existence of several phases of crystals like graphite around the peaks of 36o and 44o, there are two wide diffraction peaks and can be interconnected with carbon and graphite content. The SEM result showed that the carbonization of pyrolysis and activation processes created porosity and a large surface area for absorption.Keywords: activated carbon, coconut shell, FTIR, SEM, XRD
16
Kwiatkowski, Mirosław, and Elżbieta Broniek. "Computer Analysis of the Porous Structure of Activated Carbons Derived from Various Biomass Materials by Chemical Activation." Materials 14, no. 15 (July 23, 2021): 4121. http://dx.doi.org/10.3390/ma14154121.
Full textAbstract:
In this study, the preparation of activated carbons from various materials of biomass origin by activation with potassium hydroxide and a comprehensive computer analysis of their porous structure and adsorption properties based on benzene (C6H6) adsorption isotherms were carried out. In particular, the influence of the mass ratio of the activator’s dry mass to the char mass on the formation of the microporous structure of the obtained activated carbons was analysed. The summary of the analyses carried out based on benzene adsorption isotherms begged the conclusion that activated carbon with a maximum adsorption volume in the first adsorbed layer and homogeneous surface can be obtained from ebony wood at a mass ratio of the activator to the char of R = 3. The obtained results confirmed the superiority of the new numerical-clustering-based adsorption analysis (LBET) method over simple methods of porous structure analysis, such as the Brunauer–Emmett–Teller (BET) and Dubinin–Raduskevich (DR) methods. The LBET method is particularly useful in the evaluation of the influence of the methods and conditions of production of activated carbons on the formation of their porous structure. This method, together with an appropriate economic analysis, can help in the precise selection of methods and conditions for the process of obtaining activated carbons at specific manufacturing costs, and thus makes it possible to obtain materials that can successfully compete with those of other technologies used in industrial practice and everyday life.
17
Langdon, R. C., and A. Hochschild. "A genetic method for dissecting the mechanism of transcriptional activator synergy by identical activators." Proceedings of the National Academy of Sciences 96, no. 22 (October 26, 1999): 12673–78. http://dx.doi.org/10.1073/pnas.96.22.12673.
Full text
18
Ming, Li, Wei Xia, Bo Dong, Jun Hua Mao, Xin Wen Zhoug, and Jia Rong Pan. "Study on the Preparation and Adsorption Properties of Activated Carbon Obtained from Chinese Herbal Medicine Residue." Advanced Materials Research 904 (March 2014): 200–204. http://dx.doi.org/10.4028/www.scientific.net/amr.904.200.
Full textAbstract:
In this paper, we use residue of ten different Chinese herbal medicine as raw material and ZnCl2, KOH,K2CO3 as activator, using chemical activation method to prepare activated carbon, and we do performance testing on the activated carbon. The experimental process includes the preparation and properties testing of activated carbon, as well as testing the content of leading components of lignin in these Chinese herbal medicine raw materials and their calorific values. We've studied the relationship between leading components of these raw materials and out put and properties of the activated carbon. As a result, we got that using KOH and K2CO3 as activator to prepare activated carbon is a good choose for residue of Chinese herbal medicine belonging to rootstock which contains high content of lignin.And ZnCl2 for residue of Chinese herbal medicine belonging to cane.
19
Bilek, Vlastimil, Oldrich Sucharda, and David Bujdos. "Frost Resistance of Alkali-Activated Concrete—An Important Pillar of Their Sustainability." Sustainability 13, no. 2 (January 6, 2021): 473. http://dx.doi.org/10.3390/su13020473.
Full textAbstract:
Sustainable development of concrete construction requires sustainable materials or sustainable binders. Specifically, alkali-activated materials (AAMs) are an interesting and wide group of materials. They have good strengths and are considered environmentally friendly materials because secondary materials are consumed during the preparation of AAMs. The durability of AAMs is also excellent. One of the most important parts of durability is frost resistance. The frost resistance of alkali-activated materials is usually very good. However, some studies showed opposite properties and poor frost resistance. The reason for this may be a different composition of the activator. The content of alkalis is often considered the main characteristic of alkali-activated materials. However, SiO2 content can play an important role too. This paper discusses the different results for the mechanical properties and frost resistance of different compositions of alkali activators made of sodium water glass with a silicate modulus modified with potassium hydroxide. The role of the activator content and the water-to-cement ratio in this phenomenon is discussed. The results of this article show that the strengths of AAMs are significantly affected by the curing method. Water curing reduced some of the strength of the specimens compared to foil-covered specimens. Frost resistance depends on the method of curing and on the composition of the activator; some concretes with high strengths showed very low frost resistance.
20
John, Victoria H., Tim J. Dale, Emma C. Hollands, Mao Xiang Chen, Leanne Partington, David L. Downie, Helen J. Meadows, and Derek J. Trezise. "Novel 384-Well Population Patch Clamp Electrophysiology Assays for Ca2+-Activated K+ Channels." Journal of Biomolecular Screening 12, no. 1 (November 12, 2006): 50–60. http://dx.doi.org/10.1177/1087057106294920.
Full textAbstract:
Planar array electrophysiology techniques were applied to assays for modulators of recombinant hIK and hSK3 Ca2+-activated K+ channels. In CHO-hIK—expressing cells, under asymmetric K+ gradients, small-molecule channel activators evoked time- and voltage-independent currents characteristic of those previously described by classical patch clamp electrophysiology methods. In single-hole (cell) experiments, the large cell-to-cell heterogeneity in channel expression rendered it difficult to generate activator concentration-response curves. However, in population patch clamp mode, in which signals are averaged from up to 64 cells, well-to-well variation was substantially reduced such that concentration-response curves could be easily constructed. The absolute EC50 values and rank order of potency for a range of activators, including 1-EBIO and DC-EBIO, corresponded well with conventional patch clamp data. Activator responses of hIK and hSK3 channels could be fully and specifically blocked by the selective inhibitors TRAM-34 and apamin, with IC50 values of 0.31 μM and 3 nM, respectively. To demonstrate assay precision and robustness, a test set of 704 compounds was screened in a 384-well format of the hIK assay. All plates had Z′ values greater than 0.6, and the statistical cutoff for activity was 8%. Eleven hits (1.6%) were identified from this set, in addition to the randomly spiked wells with known activators. Overall, our findings demonstrate that population patch clamp is a powerful and enabling method for screening Ca2+-activated K+ channels and provides significant advantages over single-cell electrophysiology (IonWorksHT) and other previously published approaches. Moreover, this work demonstrates for the 1st time the utility of population patch clamp for ion channel activator assays and for non—voltage-gated ion channels.
21
von der Mohlen, MA, SJ van Deventer, M. Levi, B. van den Ende, NI Wedel, BJ Nelson, N. Friedmann, and JW ten Cate. "Inhibition of endotoxin-induced activation of the coagulation and fibrinolytic pathways using a recombinant endotoxin-binding protein (rBPI23)." Blood 85, no. 12 (June 15, 1995): 3437–43. http://dx.doi.org/10.1182/blood.v85.12.3437.bloodjournal85123437.
Full textAbstract:
A recombinant endotoxin-neutralizing protein, rBPI23, was shown to partially prevent endotoxin-induced activation of the fibrinolytic and coagulation systems in experimental endotoxemia in humans. In a placebo-controlled, blinded crossover study, eight volunteers were challenged twice with an intravenous bolus injection of endotoxin (40 EU/kg of body weight) and concurrently received either rBPI23 (1 mg/kg) or placebo (human serum albumin, 0.2 mg/kg). rBPI23 treatment significantly lowered the endotoxin-induced fibrinolytic response, ie, reduced the release of tissue-type plasminogen activator, urokinase-type plasminogen activator, plasminogen activator inhibitor antigen, and complex formation of plasmin alpha 2-antiplasmin (P = .0078 for each). Plasminogen activator inhibitor activity was also reduced, but not significantly according to the Hochberg method (P = .0304). The endotoxin-induced activation of the procoagulant state as reflected by increase in F1 + 2 fragments and TAT complexes was blunted by rBPI23 infusion (P = .0391 [not significant according to the Hochberg method] and .0078, respectively). These results indicate that rBPI23 is capable of reducing both the activation of the fibrinolytic and the coagulation systems after low-dose endotoxin infusion in humans.
22
Mierzwiński, Dariusz, Janusz Walter, and Piotr Olkiewicz. "The influence of alkaline activator concentration on the apparent activation energy of alkali-activated materials." MATEC Web of Conferences 322 (2020): 01008. http://dx.doi.org/10.1051/matecconf/202032201008.
Full textAbstract:
The aim of this article is to analyse the changes of apparent activation energy (Ea) of alkali-activated materials (AAM) at temperatures up to 100°C. Apparent activation energy (Ea) refers to the minimum amount of energy is required for the occurrence of reaction. The existing AAM research is based on assumptions about Portland cement (OPC). A number of studies have been conducted on the development of concrete strength depending on, inter alia, the duration of seasoning and the liquid to solid ratio (L/S). Based on the apparent activation energy and taking into account the effect of time and temperature at the same time, the physical and mechanical properties of OPC can also be predicted. The influence of the activator on the solidification process should also be taken into account for alkali-activated materials. This article shows the effect of changes in the concentration of the alkaline solution used in the AAM process on activation energy. The synthesized AAM material uses a solution based on water glass, sodium hydroxide, sand and volatile ash from the ‘Skawina’ coal-fired power plant (located in Skawina, Lesser Poland). The chemical composition of the material used is classified as class F ash. The concentration of the alkaline solution was 8M, 10M, 12M and 14M. The described research method was based on the use of thermistors with a negative temperature factor. It enabled prediction of the physical and mechanical properties of the materials tested. The results clearly indicate that this method can be used to determine the activation energy of the AAM. However, when determining apparent activation energy (Ea), the time and activation temperature of the binding processes of these types of materials should be taken into consideration.
23
Malovanyy, Myroslav, Ihor Bordun, Iryna Ableeva, Halyna Krusir, and Olha Sahdeeva. "Synthesis of ActivaTED Carbon from Plant Raw Materials by a Self-Activation Modified Method." Materials Science Forum 1038 (July 13, 2021): 266–75. http://dx.doi.org/10.4028/www.scientific.net/msf.1038.266.
Full textAbstract:
In order to increase environmental safety and reduce the cost of production, a modified method of self-activation for the synthesis of activated carbon from plant wastes - cherry stones and wheat straw. A 5% solution of orthophosphate acid was used as an additional activator. Synthesis of activated carbon at temperatures of 600 °C, 700 °C and 800 °C was performed. It was found that coal from cherry stones has a production of 1.3-1.6 times higher than the production of activated carbon from wheat straw. The obtained coal was studied by electron microscopy and the method of isothermal adsorption / desorption of nitrogen. It is shown that all synthesized coal has a well-developed porous structure, which is determined mainly by micropores. An increase in the synthesis temperature leads to an increase in the specific surface area, the volume of micro-and mesopores and a decrease in the average pore radius. The reduction of the average pore radius for activated carbon from cherry stones occurs at lower temperatures compared to coal from wheat straw.
24
Vidyanova Anggun Mentari, Gewa Handika, and Seri Maulina. "PERBANDINGAN GUGUS FUNGSI DAN MORFOLOGI PERMUKAAN KARBON AKTIF DARI PELEPAH KELAPA SAWIT MENGGUNAKAN AKTIVATOR ASAM FOSFAT (H3PO4) DAN ASAM NITRAT (HNO3)." Jurnal Teknik Kimia USU 7, no. 1 (April 4, 2018): 16–20. http://dx.doi.org/10.32734/jtk.v7i1.1629.
Full textAbstract:
Indonesia is one of the biggest producent of palm oil in the world. According to Badan Pusat Statistik (Central Bureau of Statistics), on 2016 wide of the palm oil estate in Indonesia is 11.672.861 Ha. The waste of palm oil plantations so many and isn’t used optimal, for the example is oil palm frond. Oil palm frond is one of the wet of waste with the number of production as much as 19.143.492 ton on 2016. This research will discuss the comparison of functional group and surface morphology activated carbon of oil palm frond with use H3PO4 and HNO3 as an activator. This research purpose to know the comparison of functional group and surface morphology activated carbon of oil palm frond with use H3PO4 and HNO3 as an activator. The method includes impregnation, carbonization, and washing process. The concentration of activator is 20% with 400 oC activation temperature. This research is used morphology surface activated carbon analysis with SEM and FTIR spectrophotometer. The result of analysis with SEM show there is pore formed on activated carbon and the indentification with spechtrophotometer FTIR shows that activated carbon is contain of functional group are C=O, C=C, C-C, N=O, C-N, C-OH, CH2and C-H.
25
Yasdi, Yasdi, Dhea Ussarvi, Rinaldi Rinaldi, Febri Juita, and Shassy Endah Cahyani. "Coconut shell-based activated carbon preparation and its adsorption efficacy in reducing BOD from The Real Wastewater from Kitchen Restaurant (RWKR): Characteristics, Sorption Capacity, and Isotherm Model." Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan 18, no. 1 (March 13, 2021): 116–30. http://dx.doi.org/10.14710/presipitasi.v18i1.116-130.
Full textAbstract:
Real Wastewater from Kitchen Restaurant (RWKR) contains high concentrations of Biochemical Oxygen Demand (BOD) pollutants to pollute the environment. One of the processing alternatives to reduce BOD is the adsorption method using activated carbon from coconut shells. This study aims to determine coconut shell-activated carbon as an adsorbent for the adsorption of organic matter to reduce BOD in RWKR. The method begins with making adsorbents that are activated with activators on HCl 3 M, NaOH 3 M, and H3PO4 M, then a preliminary adsorption test is carried out to select the best activator on coconut shell activated carbon to reduce BOD in RWKR. Determining the optimum conditions for adsorption was carried out by varying pH 3, 4, 5, 6, 7, and 8. Variation of contact time with a stirring speed of 250 rpm, then determined the isotherm model. The remaining organic matter in the wastewater will be measured using a DO meter based on SNI 6989.72: 2009 concerning the method of testing for biochemical oxygen demand (BOD). The results showed that the appropriate activator for coconut shell activated carbon was H3PO4 3 M with an average percentage value of uptake of 89.690%. The adsorption process's optimum pH is at pH 3 with an absorption percentage value of 88.626%. The optimum contact time is at 10 minutes and the adsorption isotherm model used is the Freundlich isotherm with a regression value of R2 = 0.8864.
26
Yao, Shu-hua, Xue-jing Chen, Mario Alberto Gomez, Xi-chun Ma, Hai-bo Wang, and Shu-yan Zang. "One-step synthesis of zerovalent-iron–biochar composites to activate persulfate for phenol degradation." Water Science and Technology 80, no. 10 (November 15, 2019): 1851–60. http://dx.doi.org/10.2166/wst.2020.001.
Full textAbstract:
Abstract A novel zerovalen-iron–biochar composite (nZVI/SBC) was synthesized by using FeCl3-laden sorghum straw biomass as the raw material via a facile one-step pyrolysis method without additional chemical reactions (e.g., by NaBH4 reduction or thermochemical reduction). The nZVI/SBC was successfully employed as an activator in phenol degradation by activated persulfate. XRD, SEM, N2 adsorption–desorption and atomic absorption spectrophotometry analysis showed that the nanosized Fe0 was the main component of the 4ZVI/SBC activator, which was a mesopore material with an optimal FeCl3·6H2O/biomass impregnation mass ratio of 2.7 g/g. The 4ZVI/SBC activator showed an efficient degradation of phenol (95.65% for 30 min at 25 °C) with a large specific surface area of 78.669 m2·g−1. The recovery of 4ZVI/SBC activator after the degradation reaction of phenol can be realized with the small amount of dissolved iron in the water. The 4ZVI/SBC activator facilitated the activation of persulfate to degrade phenol into non-toxic CO2 and H2O. The trend of Cl−, SO42− and NO3− affected the removal efficiency of phenol by using the 4ZVI/SBC activator in the following order: NO3− > SO42− > Cl−. The one-step synthesis of the nanosized zerovalent-iron–biochar composite was feasible and may be applied as an effective strategy for controlling organic waste (e.g. phenol) by waste biomass.
27
Naceri, A., M. S. Bouglada, and A. Belouar. "Activation of Slag Cement by Hydrated Lime." Applied Mechanics and Materials 71-78 (July 2011): 706–11. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.706.
Full textAbstract:
In this experimental study, the setting agent Ca(OH)2 used for activation of slag cement is used in the proportions of 0%, 2%, 4%, 6%, 8% and 10% by substitution method by mass of slag cement. The results indicated that the mineral activator has a significant effect on the flexural and compressive strengths. The optimum percentage of the mineral activator (hydrated lime) ranges between 2 to 4%. The activation of the slag cement by fine lime (calcium hydroxide) is a simple and economic method especially for cement containing not very reactive slag or low reactivity due to its low CaO/SiO2.
28
Escher, Dominik, and Walter Schaffner. "Improved “Activator Trap” Method for the Isolation of Transcriptional Activation Domains from Random DNA Fragments." BioTechniques 21, no. 5 (November 1996): 848–54. http://dx.doi.org/10.2144/96215st02.
Full text
29
Summaria, L., J. Sandesara, G. Yang, J. P. Vagher, and J. A. Caprini. "In Vitro Comparison of Fibrinolytic Activity of Plasminogen Activators Using a Thrombelastographic Method: In Vivo Evaluation of the B-Chain-Streptokinase Complex in the Dog Model Using Pre-Titered Doses." Thrombosis and Haemostasis 56, no. 01 (1986): 071–79. http://dx.doi.org/10.1055/s-0038-1661606.
Full textAbstract:
SummaryThrombelastography was used to quantitatively compare the clot-lysing efficiency of 6 different plasminogen activators, using human whole blood, pooled normal plasma, and platelet rich plasma. The activators compared were the B-chain-streptokinase complex, the plasmin-streptokinase complex, the mini-plasmino-gen-streptokinase complex, tissue plasminogen activator, streptokinase, and urokinase. The most efficient activator found was the B-chain-streptokinase complex. This complex was 4.0 times more effective than streptokinase, 3.0 times more effective than the plasmin-streptokinase complex, 1.3 times more effective than the mini-plasminogen-streptokinase complex, 2.3 times more effective than tissue plasminogen activator, and 16.0 times more effective than urokinase. Although there were differences in both the coagulation and fibrinolysis thrombelastographic patterns between plasma and whole blood, the comparative efficiencies of each activator were the same with either plasma or bloodThe B-chain-streptokinase complex was evaluated as a thrombolytic agent in clot-lysis experiments in the jugular vein in the dog model, using a thrombelastographic method to determine the minimum dose of activator necessary for clot-lysis. With 6 dogs infused locally with 0.25 mg (8000 I.U.) of the plasmin-streptokinase complex, the cumulative clot-lysis was 18.0 ± 3.0% with the first dose, 33.0 ± 2.1% with the second dose, and 55.2 ± 8.6% with the third dose. With 6 dogs infused locally with 0.03 mg (2000 I.U.) of the B-chain-streptokinase complex, the cumulative clot-lysis was 30.6 ± 6.4% with the first dose, 54.4 ± 9.6% with the second dose, and 80.2 ± 9.0% with the third dose.
30
Kupesiz, Alphan, Madhvi Rajpurkar, Indira Warrier, Wendy Hollon, Ozgur Tosun, Jeanne Lusher, and Meera Chitlur. "Tissue plasminogen activator induced fibrinolysis: standardization of method using thromboelastography." Blood Coagulation & Fibrinolysis 21, no. 4 (June 2010): 320–24. http://dx.doi.org/10.1097/mbc.0b013e32833464e9.
Full text
31
Juang, Shin-Hun, Min-Tsang Hsieh, Pei-Ling Hsu, Ju-Ling Chen, Hui-Kang Liu, Fong-Pin Liang, Sheng-Chu Kuo, et al. "Studies of Coumarin Derivatives for Constitutive Androstane Receptor (CAR) Activation." Molecules 26, no. 1 (December 31, 2020): 164. http://dx.doi.org/10.3390/molecules26010164.
Full textAbstract:
Constitutive androstane receptor (CAR) activation has found to ameliorate diabetes in animal models. However, no CAR agonists are available clinically. Therefore, a safe and effective CAR activator would be an alternative option. In this study, sixty courmarin derivatives either synthesized or purified from Artemisia capillaris were screened for CAR activation activity. Chemical modifications were on position 5,6,7,8 with mono-, di-, tri-, or tetra-substitutions. Among all the compounds subjected for in vitro CAR activation screening, 6,7-diprenoxycoumarin was the most effective and was selected for further preclinical studies. Chemical modification on the 6 position and unsaturated chains were generally beneficial. Electron-withdrawn groups as well as long unsaturated chains were hazardous to the activity. Mechanism of action studies showed that CAR activation of 6,7-diprenoxycoumarin might be through the inhibition of EGFR signaling and upregulating PP2Ac methylation. To sum up, modification mimicking natural occurring coumarins shed light on CAR studies and the established screening system provides a rapid method for the discovery and development of CAR activators. In addition, one CAR activator, scoparone, did showed anti-diabetes effect in db/db mice without elevation of insulin levels.
32
Li, Rong, David S. Yu, Masafumi Tanaka, Liyi Zheng, Shelley L. Berger, and Bruce Stillman. "Activation of Chromosomal DNA Replication inSaccharomyces cerevisiae by Acidic Transcriptional Activation Domains." Molecular and Cellular Biology 18, no. 3 (March 1, 1998): 1296–302. http://dx.doi.org/10.1128/mcb.18.3.1296.
Full textAbstract:
ABSTRACT A large body of evidence from viral systems has established that transcription factors play an important and direct role in activating viral DNA replication. Among the transcriptional activation domains that can stimulate viral DNA replication are acidic domains such as those derived from herpes simplex virus VP16 and the tumor suppressor p53. Here we show that acidic activation domains can also activate a cellular origin of replication in a chromosomal context. When tethered to the yeast ARS1 (autonomously replicating sequence 1) origin of replication, both VP16 and p53 activation domains can enhance origin function. In addition, the C-terminal acidic region of the yeast transcription factor ABF1, which normally activates the ARS1 origin, is sufficient for activating ARS1 function when tethered to the origin. Mutations at residues Trp-53 and Phe-54 of a 20-residue (41 to 60) activation region of p53 abolish the activation of both replication and transcription, suggesting that the same structural determinants may be employed to activate both processes in yeast. Furthermore, using a two-dimensional gel electrophoresis method, we demonstrate that the GAL4-p53 chimeric activator can activate initiation of chromosomal replication from an origin inserted at the native ARS1 locus. These findings strongly suggest functional conservation of the mechanisms used by the acidic activation domains to activate viral DNA replication in mammalian cells and chromosomal replication in yeast.
33
Dony, Wari, and Amsori M. Das. "Studi Mikrostruktur Mortar Geopolimer Abu Sawit dengan Variasi Rasio Na2SiO3 terhadap NaOH." Jurnal Ilmiah Universitas Batanghari Jambi 19, no. 1 (January 22, 2019): 132. http://dx.doi.org/10.33087/jiubj.v19i1.587.
Full textAbstract:
In the context development of building materials geopolymer concrete is an environmentally technology. The goal of the study identifies and examines geopolymer concrete becoming alternative to portland cement (PC) as a construction material section is utilized as one of the local plantation industry waste such as oil palm ash. Polymerzation process performed the oil palm ash as precursor that contains high silicate calcium with Na2SiO3 and NaOH as alkali activator. Mix design is carried out by ratio of alkali activator 2,0. 1,5 and 1,0 at a concentration of NaOH 8, 10, 12, 14 and 16 M at temperature 90°C for 24 hours. The method used is the separate mixtures with extra water and mixed methods directly without extra water. The result show that the higher concentration of NaOH solution, the compressive strength is increased at level of 12,4 Mpa=8,4 M for the mortar with extra water and 20,2 Mpa= 16 M without extra water at ratio of 1,5 alkaline activators. The ratio mixture of alkali activator 1,0and 2,0 would produce a low compressive strength. Microstructure result shows that matrix is formed more solid at each increase in the concentration of Na OH solution. The ratio of Alkali activator 1,5 causing precursors and alkaline activators to react homogeneously so that the formed geopolymer matrix becomes more solid
34
Wang, Fulin, Guoliang Chen, Lu Ji, and Zhengping Yuan. "Preparation and Mechanical Properties of Cemented Uranium Tailing Backfill Based on Alkali-Activated Slag." Advances in Materials Science and Engineering 2020 (April 25, 2020): 1–7. http://dx.doi.org/10.1155/2020/6345206.
Full textAbstract:
Backfilling disposal based on cement solidification is one of the ways to solve the environmental and safe problems of uranium tailing surface stacking. Alkali-activated slag, especially sodium silicate activated geopolymer, has become the preferred cementing material for the uranium tailing backfilling system because of its advantages of corrosion resistance and high strength. In this paper, uranium tailings and slag are taken as research objects, and the unconfined compressive strength (UCS) is taken as the main quality index. The preparation method of the cemented uranium tailing backfill based on alkali-activated slag was studied, hereinafter referred to as CUTB. The effects of additive amount, activator amount and activator modulus on the strength of CUTB were investigated. The results show that alkali-activated slag is an effective cementing material for the backfilling system of uranium tailing aggregate. The maximum UCS of 28 d age in the test groups is 16.45 MPa. Quicklime is an important additive for preparing CUTB. When the amount of quicklime is 0%, the early and late strengths of the filling body cannot be measured or at a very low level. At the age of 7 d, the order of each factor is additive amount > activator modulus > activator amount, but at the age of 28 d, the order of each factor is additive amount > activator amount > activator modulus. The test results can provide a basis for choosing cementitious materials for backfilling disposal of uranium tailings.
35
Sabu, Akshay, and Nirmalakumar Rajamane. "User-friendly novel method of geopolymer con-crete production mixes." International Journal of Engineering & Technology 7, no. 2 (May 12, 2018): 714. http://dx.doi.org/10.14419/ijet.v7i2.10817.
Full textAbstract:
Geopolymer is an inorganic polymer, which can perform as an effective binder in place of Portland cement. With this, the Geopolymer concrete has become highly Ecofriendly with very low carbon footprint. The GPC formulation at present utilises industrial waste materials like fly ash and GGBS, which are activated with well-proportioned alkaline liquid. At present the commercially available lye and Sodium Silicate solution are used to prepare alkaline liquid capable of initiating geopolymer reaction. It is noticed that the liquid system has limited shelf life by making field production of Geopolymer concrete mixes was a difficult one more over the liquid system and its ingredients are difficult to transport over longer distances. This has been the main obstacle for development of large-scale applications of GPC mixes on commercial basis. This issue was addressed in the present study by using solid activator in replacement of liquid solution. The solid activating system can be produced just before the preparation of fresh GPC mixes at anyway at any time. It is found that the mechanical strength (40 – 45Mpa) property was similar to the liquid activating GPC mixes. This new technique of production of GPC mixes using solid activators can be consider as the major breakthrough for commercialization / large scale field applications of Geopolymer technology.
36
Purnawan, Candra, Christina Candra Dewi, Syafrudin Syafrudin, Bimastyaji Surya Ramadan, Mochamad Arief Budihardjo, Agus Jatnika Effendi, and Syarif Hidayat. "The Influence of ZnCl2 Activation on Macronutrient NPK Adsorption Simultaneously Using Coconut Shell Biochar for Soil Fertility Improvement." Molekul 16, no. 1 (March 28, 2021): 75. http://dx.doi.org/10.20884/1.jm.2021.16.1.713.
Full textAbstract:
The influence of ZnCl2 activation on macronutrient Nitrogen, Phosphor, Potassium (NPK) adsorption simultaneously using Coconut Shell Biochar for soil fertility improvement has been conducted. Biochar formation is carried out at temperature up to 500 oC using variation in the concentration of ZnCl2 0,5; 1,0; 1,5; 2,0; dan 2,5 M. The biochar formed was characterized using Fourier Transform InfraRed (FTIR) spectroscopy and Surface Area Analyzer (SAA). Whereas NPK analysis has used the Indonesian standard method (SNI 7763: 2018). Based on this research, it was concluded that the greater the concentration of ZnCl2 activator, indicated that the higher intensity of the spectra of –OH and –NH2 at wave number 3400 cm-1 and 1600 cm-1. It showed that biochar activation was higher and a more active functional group was opened. Increasing the concentration of ZnCl2 activator has increased Biochar adsorption of NPK macronutrients. The optimum condition for activation of coconut shell Biochar was activation with ZnCl2 2.5 M. The addition of activated Biochar was increased soil adsorption on NPK macronutrients. Biochar addition had increased Nitrogen (N) adsorption up to 23.53%, Phosphor (P) up to 200%, and Potassium (K) up to 41.24%.
37
Karima, Rizka, and Nurmilatina Nurmilatina. "Pengaruh Variasi Aktivator dan Doping terhadap Nilai Daya Hantar Listrik dan Karakterisasi Karbon dari Bambu (Effect of Activator and Doping Variation on The Electrical Conductivity and Carbon Characteristics of Bamboo)." Jurnal Riset Industri Hasil Hutan 10, no. 1 (June 1, 2018): 11–20. http://dx.doi.org/10.24111/jrihh.v10i1.3683.
Full textAbstract:
An added value of bamboo charcoal that is commonly used as an energy source could be increased by the addition of activator and metal doping. The objective of this research was to analyze the effect of the addition of activator and doping to the electrical conductivity and carbon characteristics for a raw material of bio-battery. Bamboo plantsused in this experiment were buluh, haur, and betung. Bamboo was carbonized inthe temperature range between 500oC and 600oC by pyrolysis method. Obtained charcoal was activated using two types of chemicals, KOH and HNO3, and then was doped with Zn and Ni. Furthermore, obtained carbon was made into nanoparticles using High Energy Milling. The structure and properties of the carbon were tested using PSA, SEM, and XRD; and the conductivity was also tested. The smallest particle size was obtained from ‘buluh’ bamboo charcoal with HNO3 activation and without a doping at 1030 nm. The diffractogram and topography of the bamboo charcoal varied depending on the metal doping added. The highest electrical conductivity (DHL) was obtained from betung charcoal with an activator of KOH and a doping of Zn at 7.02 mS/cm.
38
Nie, Wenlin, Jianjun Fang, Shuming Wen, Qicheng Feng, Yanbing He, and Xiaoyong Yang. "Estimation and Improvement of Recovery of Low Grade Copper Oxide Using Sulfide Activation Flotation Method Based on GA–BPNN." Processes 9, no. 4 (March 26, 2021): 583. http://dx.doi.org/10.3390/pr9040583.
Full textAbstract:
Copper oxide ore is an important copper ore resource. For a certain copper oxide ore in Yunnan, China, experiments have been conducted on the grinding fineness, collector dosage, sodium sulfide dosage, inhibitor dosage, and activator dosage. The results showed that, by controlling the above conditions, better sulfide flotation indices of copper oxide ore are obtained. Additionally, ammonium bicarbonate and ethylenediamine phosphate enhanced the sulfide flotation of copper oxide ore, whereas the combined activator agent exhibited a better performance than either individual activator. In addition, to optimize all of the conditions in a more reasonable way, a combination of the 5-11-1 genetic algorithm and back propagation neural network (GA–BPNN) was used to set up a mathematical optimization model. The results of the back propagation neural network (BPNN) model showed that the R2 value was 0.998, and the results were in accordance with the requirement model. After 4169 iterations, the error in the objective function was 0.001, which met the convergence requirements for the final solution. The genetic algorithm (GA) model was used to optimize the BPNN model. After 100 generations, a copper recovery of 87.62% was achieved under the following conditions: grinding fineness of 0.074 mm, which accounted for 91.7%; collector agent dosage of 487.7 g/t; sodium sulfide dosage of 1157.2 g/t; combined activator agent dosage of 537.8 g/t; inhibitor dosage of 298.9 g/t. Using the combined amine and ammonium salt to enhance the sulfide activation efficiency, a GA–BPNN model was used to achieve the goal of global optimizations of copper oxide ore and good flotation indices were obtained.
39
Zamoryanskaya, M. V., and V. I. Sokolov. "Characterization of SiO2/Si Interface by Cathodoluminescent Method." Solid State Phenomena 131-133 (October 2007): 629–34. http://dx.doi.org/10.4028/www.scientific.net/ssp.131-133.629.
Full textAbstract:
The local cathodoluminescence is used to study the point defects and their depth distribution in silicon oxide and silicon. The defects formed by two-coordinate silicon (Si=Si), oxygen vacancies (Si-Si, Si-Si-Si), non-bridgen oxygen (-O.), amorphous silicon and silicon nanoclusters have characteristic emission bands. High sensibility of cathodoluminescence method permits to study natural silicon oxide film, thin silicon oxide and silicon layers near the interface. In this paper an influence of the silicon type on the properties of SiO2/Si interface is discussed. It is shown that the quality of SiO2/Si interface depends not only on the technology process but on the silicon type and activator concentration. A high boron content in silicon leads to an increase of point defects concentration in silicon oxide and sometimes to an appearance of Si nanoclusters near the interface in the layer with 10-20 nm thickness. The concentration of intrinsic defects near the silicon oxide – n-silicon interface depends also on phosphorous concentration. But in this case low concentration of activator leads to a presence of high content of intrinsic defects in the first monolayers of silicon oxide and to a dramatical decrease of a content of these defects in films with thickness of more that 10 nm. On the contrary, the high concentration of activators leads to low content of intrinsic defects near the interface and a rise of its content in the film with thickness more that 10 nm.
40
Suhendrayatna, Suhendrayatna, Abdurrahman Abdurrahman, and Elvitriana Elvitriana. "Study on the optimization of mercury ion (II) adsorption with activated carbon from a biomass combination of palm bunches and rice husk." Aceh International Journal of Science and Technology 8, no. 3 (December 31, 2019): 161–68. http://dx.doi.org/10.13170/aijst.8.3.15160.
Full textAbstract:
This research deals with the adsorption of mercury ions [Hg (II)] using a combination of natural biomass between oil palm bunches and rice husks (PB-RH). After drying at 40oC, PB-RH biomass was carbonized by using a tube furnace for 2 hours at 500 °C and followed chemical activation with citric acid. Activated carbon formed was contacted with an aqueous solution containing Hg (II) ion and stirred at a constant rate of 150 rpm. The concentration of Hg (II) ions in the aqueous phase were analyzed with Atomic Absorption Spectrophotometer (AAS) and the Central Composite Design (CCD) method with Design-Expert software version 6.0.8 was conducted to calculate the optimization of adsorption capacity for mercury ion. The Hg ion adsorption capacity was estimated to observe the performance of the PB-RH biomass combination on the adsorption of Hg (II) ions with some variables, such as contact time, biomass weight, and activator concentration. Results showed that all variable response, contact time, biomass weight, and activator concentration influenced the mercury (II) ion adsorption capacity. The optimum condition of Hg (II) ion adsorption occurred at 30 g of activated PB-RH biomass with 0.6 mole/L concentration of activator during 99.88 minutes with 99.42 mg/L initial concentration of Hg (II). The adsorption capacity occurred at 10.1 mg/g as the optimum condition for the adsorption of Hg (II) ions by PB-RH.
41
Thomas, Stephen P., and Jingying Peng. "Activation Strategies for Earth-Abundant Metal Catalysis." Synlett 31, no. 12 (April 6, 2020): 1140–46. http://dx.doi.org/10.1055/s-0039-1690873.
Full textAbstract:
The use of earth-abundant metal-catalysed organic transformations has increased significantly in recent years. Where low-oxidation-state catalysts are required, the in situ activation of metal(II/III) salts offers an operationally simple method to access these catalysts. Here we present the development of activation strategies from the use of reducing organometallic reagents to endogenous activation. Applications in alkene and alkyne hydrofunctionalisation reactions will be used to highlight the synthetic applications of the activation methods discussed.1 Introduction2 In situ Activation Using Organometallic Reagents3 In situ Activation Using Nonorganometallic Reagents4 ‘Activator-Free’ Systems5 Conclusions
42
Giachetti, E., and P. Vanni. "Effect of Mg2+ and Mn2+ on isocitrate lyase, a non-essentially metal-ion-activated enzyme. A graphical approach for the discrimination of the model for activation." Biochemical Journal 276, no. 1 (May 15, 1991): 223–30. http://dx.doi.org/10.1042/bj2760223.
Full textAbstract:
We describe a simple method for the analysis of activation systems in which a metal ion modifier may combine with either the enzyme or the substrate (or both) and the metal ion-substrate complex is the true substrate of the enzyme reaction. The suggested approach is essentially a ‘graphical’ method that both provides unbiased criteria for the choice of the activation mechanism and yields good rough estimates of the kinetic parameters. The procedure, tested on a variety of simulated models, produces appropriate and reliable results. Applying this treatment to isocitrate lyase, we confirmed the data previously reported for Mg2+ [Giachetti, Pinzauti, Bonaccorsi & Vanni (1988) Eur. J. Biochem. 172, 85-92], and we found that Mn2+ functions with the same mechanism as does Mg2+, but with quite different kinetic constants. In particular, its ratio of the Vmax, values of the activated and the non-activated enzyme is less than 1, and thus Mn2+ is to be considered an inhibitor rather than an activator.
43
Jadhav, Abhijit, and Govindraj Mohanraj. "Synthesis of Activated Carbon from Cocos Nucifera Leaves Agrowaste by Chemical Activation Method." Chemistry & Chemical Technology 10, no. 2 (June 15, 2016): 201–8. http://dx.doi.org/10.23939/chcht10.02.201.
Full textAbstract:
Activated carbon from Cocos nucifera leaves agrowaste was derived. The effect of impregnation ratio was studied by chemical activation method using phosphoric acid as an activating agent. Activated carbon was produced at the activation temperature of 673 K by slow pyrolysis. Nitrogen adsorption isotherms study was performed. Effect of impregnation ratio on the yield, methylene blue number, iodine number, and acid adsorption was studied. The FT-IR spectra show the presence of activated carbon. The TGA investigation reveals that activated carbon is thermally stable at 723 K. The SEM images show the incorporation of activated carbon particles which lead to the systematic change in the morphology of activated carbon. Surface chemistry study predicts the acidic and basic functional groups of Cocos nucifera leaves activated carbon.
44
Fang, Qin, Ren Qing Wang, and Mei Gen Deng. "Research of Activated Carbon for Supercapacitor Prepared by Organic Template Method." Materials Science Forum 663-665 (November 2010): 551–54. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.551.
Full textAbstract:
Activated carbon was fabricated by using phenolic resin as carbon source, PEG as organic template, KOH as activator. The samples were analyzed by N2 adsorption, scanning electron microscopy (SEM). Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that the specific surface area of the prepared sample (AC1) was 2469 m2/g, the pore size was mainly in the range of 1.0～4.0 nm. At a current density of 7.5 mA/cm2, a specific capacitance of 327F/g was achieved, the equivalent series resistance (ESR) was 0.8Ω. Supercapacitors based on the sample have low ESR and excellent power property. For comparison, commercial AC (AC2) was also studied.
45
Levin, EG. "Quantitation and properties of the active and latent plasminogen activator inhibitors in cultures of human endothelial cells." Blood 67, no. 5 (May 1, 1986): 1309–13. http://dx.doi.org/10.1182/blood.v67.5.1309.1309.
Full textAbstract:
Abstract Human endothelial cells release two forms of a plasminogen activator- specific inhibitor: an active form that readily binds to and inhibits plasminogen activators and an inactive or latent form that has no anti- activator activity but which can be activated by denaturation. Latent and active forms of plasminogen activator-specific inhibitor were measured in cultures of human umbilical vein endothelial cells. Latent inhibitor was activated by treatment with 1% sodium dodecyl sulfate (SDS), and both forms were assayed by the 125I-fibrin plate method. After 16 hours, the conditioned medium contained 104.6 U/mL latent inhibitor activity and 2.6 U/mL active inhibitor. The level of each form in the culture medium increased with time although the activity associated with the latent form rose more rapidly: the ratio of latent to active inhibitor activity was 12 at four hours (10.3 U/mL v 0.86 U/mL) and reached 56 at 24 hours (155.3 U/mL v 2.80 U/mL). Intracellular inhibitor activity was associated with the active form only; no additional inhibitor activity was observed following SDS treatment of cell extracts. A decline in active inhibitor activity occurred during incubation at 37 degrees C with a 50% reduction in activity occurring in two hours. Treatment of conditioned medium with 10 U/mL thrombin also resulted in a loss of active inhibitor activity. The latent inhibitor, however, was not affected by either of these conditions. The inhibitor activity lost during incubation at 37 degrees C or thrombin treatment could be regenerated by SDS treatment, suggesting that the loss of the active inhibitor activity represented a conversion of this form to its latent counterpart. Thus, the concentration, stability, and regulation of these two forms of plasminogen activator inhibitor in human endothelial cell cultures differ significantly.
46
Levin, EG. "Quantitation and properties of the active and latent plasminogen activator inhibitors in cultures of human endothelial cells." Blood 67, no. 5 (May 1, 1986): 1309–13. http://dx.doi.org/10.1182/blood.v67.5.1309.bloodjournal6751309.
Full textAbstract:
Human endothelial cells release two forms of a plasminogen activator- specific inhibitor: an active form that readily binds to and inhibits plasminogen activators and an inactive or latent form that has no anti- activator activity but which can be activated by denaturation. Latent and active forms of plasminogen activator-specific inhibitor were measured in cultures of human umbilical vein endothelial cells. Latent inhibitor was activated by treatment with 1% sodium dodecyl sulfate (SDS), and both forms were assayed by the 125I-fibrin plate method. After 16 hours, the conditioned medium contained 104.6 U/mL latent inhibitor activity and 2.6 U/mL active inhibitor. The level of each form in the culture medium increased with time although the activity associated with the latent form rose more rapidly: the ratio of latent to active inhibitor activity was 12 at four hours (10.3 U/mL v 0.86 U/mL) and reached 56 at 24 hours (155.3 U/mL v 2.80 U/mL). Intracellular inhibitor activity was associated with the active form only; no additional inhibitor activity was observed following SDS treatment of cell extracts. A decline in active inhibitor activity occurred during incubation at 37 degrees C with a 50% reduction in activity occurring in two hours. Treatment of conditioned medium with 10 U/mL thrombin also resulted in a loss of active inhibitor activity. The latent inhibitor, however, was not affected by either of these conditions. The inhibitor activity lost during incubation at 37 degrees C or thrombin treatment could be regenerated by SDS treatment, suggesting that the loss of the active inhibitor activity represented a conversion of this form to its latent counterpart. Thus, the concentration, stability, and regulation of these two forms of plasminogen activator inhibitor in human endothelial cell cultures differ significantly.
47
Merad, Miriam, Tomoharu Sugie, Edgar G. Engleman, and Lawrence Fong. "In vivo manipulation of dendritic cells to induce therapeutic immunity." Blood 99, no. 5 (March 1, 2002): 1676–82. http://dx.doi.org/10.1182/blood.v99.5.1676.
Full textAbstract:
Efficient antigen presentation and T-cell priming are essential components of effective antitumor immunity. Dendritic cells are critical to both of these functions but to date no method has been devised that both targets antigen to these cells and activates them, in situ, in a manner that induces systemic immunity. In this study we combined a dendritic cell growth factor, Flt3 ligand, with a dendritic cell activator, immunostimulatory DNA, and a tumor antigen to activate and load dendritic cells in vivo. Initial studies showed that immunostimulatory DNA not only activates dendritic cells but also prolongs their survival in vivo and in vitro. Following treatment of mice with Flt3 ligand, coadministration of immunostimulatory DNA and antigen induced potent antitumor immunity, resulting in both tumor prevention and regression of existing tumors. CD8 cytotoxic T lymphocytes but not CD4 T cells were required for tumor protection. Natural killer cells also contributed to tumor protection. These results show that dendritic cells can be loaded with antigen and activated, in situ, and provide the basis for dendritic cell- targeted clinical strategies.
48
Lemmens, Irma, Sam Lievens, and Jan Tavernier. "MAPPIT: a versatile tool to study cytokine receptor signalling." Biochemical Society Transactions 36, no. 6 (November 19, 2008): 1448–51. http://dx.doi.org/10.1042/bst0361448.
Full textAbstract:
MAPPIT (mammalian protein–protein interaction trap) is a cytokine receptor-based two-hybrid method that operates in intact mammalian cells. A bait is fused C-terminally to a STAT (signal transducer and activator of transcription) recruitment-deficient receptor, whereas the prey is linked to functional STAT-binding sites. When bait and prey interact a ligand-dependent complementation of the STAT recruitment deficiency occurs, leading to activation of a STAT-responsive reporter. MAPPIT is very well suited to study protein interactions involving activated cytokine receptors as the technique allows modification of the bait protein in a physiologically optimal environment.
49
Andrianopoulos, A., and M. J. Hynes. "Sequence and functional analysis of the positively acting regulatory gene amdR from Aspergillus nidulans." Molecular and Cellular Biology 10, no. 6 (June 1990): 3194–203. http://dx.doi.org/10.1128/mcb.10.6.3194.
Full textAbstract:
The positively acting regulatory gene amdR of Aspergillus nidulans coordinately regulates the expression of five structural genes involved in the catabolism of certain amides (amdS), omega amino acids (gatA and gabA), and lactams (lamA and lamB) in the presence of omega amino acid inducers. Analysis of the amdR gene showed that it contains three small introns, heterogeneous 5' and 3' transcription sites, and multiple AUG codons prior to the major AUG initiator. The predicted amdR protein sequence has a cysteine-rich "zinc finger" DNA-binding motif at the amino-terminal end, four putative acidic transcription activation motifs in the carboxyl-terminal half, and two sequences homologous to the simian virus 40 large T antigen nuclear localization motif. These nuclear localization sequences overlap the cysteine-rich DNA-binding motif. A series of 5', 3', and internal deletions were examined in vivo for transcription activator function and showed that the amdR product contains at least two activation regions in the carboxyl-terminal half. Each of these activator amdR product contains at least two activation regions in the carboxyl-terminal half. Each of these activator regions may function independently, but both are required for wild-type levels of transcription activation. A number of the amdR deletion products were found to compete with the wild-type amdR product in vivo. Development of a rapid method for the localization of amdR mutations is presented, and using this technique, we localized and sequenced the mutation in the semiconstitutive amdR6c allele. The amdR6c missense mutation occurs in the middle of the gene, and it is suggested that it results in an altered protein which activates gene expression efficiently in the absence of an inducer.
50
Andrianopoulos, A., and M. J. Hynes. "Sequence and functional analysis of the positively acting regulatory gene amdR from Aspergillus nidulans." Molecular and Cellular Biology 10, no. 6 (June 1990): 3194–203. http://dx.doi.org/10.1128/mcb.10.6.3194-3203.1990.
Full textAbstract:
The positively acting regulatory gene amdR of Aspergillus nidulans coordinately regulates the expression of five structural genes involved in the catabolism of certain amides (amdS), omega amino acids (gatA and gabA), and lactams (lamA and lamB) in the presence of omega amino acid inducers. Analysis of the amdR gene showed that it contains three small introns, heterogeneous 5' and 3' transcription sites, and multiple AUG codons prior to the major AUG initiator. The predicted amdR protein sequence has a cysteine-rich "zinc finger" DNA-binding motif at the amino-terminal end, four putative acidic transcription activation motifs in the carboxyl-terminal half, and two sequences homologous to the simian virus 40 large T antigen nuclear localization motif. These nuclear localization sequences overlap the cysteine-rich DNA-binding motif. A series of 5', 3', and internal deletions were examined in vivo for transcription activator function and showed that the amdR product contains at least two activation regions in the carboxyl-terminal half. Each of these activator amdR product contains at least two activation regions in the carboxyl-terminal half. Each of these activator regions may function independently, but both are required for wild-type levels of transcription activation. A number of the amdR deletion products were found to compete with the wild-type amdR product in vivo. Development of a rapid method for the localization of amdR mutations is presented, and using this technique, we localized and sequenced the mutation in the semiconstitutive amdR6c allele. The amdR6c missense mutation occurs in the middle of the gene, and it is suggested that it results in an altered protein which activates gene expression efficiently in the absence of an inducer.