Recycled sand from sandstone waste: A new source of high-quality fine aggregate

2022 ◽  
Vol 179 ◽  
pp. 106116
Author(s):  
Yubin Cao ◽  
Yanru Wang ◽  
Zuhua Zhang ◽  
Hao Wang
Keyword(s):  

The development segment for a structure solid assumes a significant job everywhere throughout the world the solid ought to have high compressive and flexural quality. Presently a day accessibility of regular assets is diminished due to the ecological issues are government limited sand quarries are supremacist in shortage and expands cost. So we need to move for the fake fine total in this paper rather than stream sand to assembling sand in incomplete supplant with SBR (polymer) in high quality on concrete different cement blends were assessed for compressive quality and Flexural quality. The common stream sand was mostly supplanted with m-sand by 0%, 25%, half and included the different rates of SBR latex (0,3,6,9,12) was likewise improving the usefulness concrete. The outcome shows that the there is a step by step expanded in the compressive quality and Flexural quality for this situation half substitution of m-sand and furthermore included the level of SBR increment the functionality However, further increases of m-sand caused a decrease in the quality. The ideal rate substitution of normal sand of m-sand is half and upgraded substance of polymer 9 % is gotten. Diagrams were drawn and results contrasted and controlled blend.


Author(s):  
Teguh Arifmawan Sudhiarta ◽  
I M. Alit K. Salain ◽  
I N. Sutarja

Concrete itself is quite popular in terms of usage in the field of construction (bridges, buildings, and dams). In large projects and unconditioned special (extreme) as the long-span bridge construction in the middle of the sea, pier construction, buildings and retaining walls high sea waves need to use high-quality concrete. To be able to make high strength concrete required fas value (water-cement ratio) is low, ranging from 0.20 to 0.30 (ACI, 1998). In high quality concrete workmanship in the field, to facilitate construction of concrete because considering using a little water, then a superplasticizer admixture materials needed to facilitate mixing concrete. This study was conducted to determine the performance of each in terms of value Slump superplasticizer, concrete compressive strength and split tensile strength of concrete. Calculation of SNI 03-6468-2000 material refers to the weight ratio of cement: fine aggregate: coarse aggregate of 1.00: 1.67: 2.15 with water cement factor of 0.317. Used to test a cylindrical specimen with a diameter of 150mm and height of 300mm which for the life of the test was made three (3) pieces of the specimen. Preparation and treatment of test specimens performed by standard procedures. The results showed that the use of superplasticizer type Napthalene Formaldehyde Sulphonate deliver results better compressive strength than the type superplasticizer Aqueous Solution Of Modified Polycarboxylate Copolymers is equal to 7.70%, but when viewed in terms of tensile strength and slump value (kelecakan) type superplasticizer Aqueous Solution Of Modified Polycarboxylate Copolymers provide better value Napthalene Formaldehyde Sulphonate when compared with that of 4.04% for split tensile strength and 22.22% for the slump value.


1966 ◽  
Vol 24 ◽  
pp. 51-52
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.


Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).


Author(s):  
A. V. Crewe ◽  
J. Wall ◽  
L. M. Welter

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.


Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).


Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.


Author(s):  
Judith M. Brock ◽  
Max T. Otten ◽  
Marc. J.C. de Jong

A Field Emission Gun (FEG) on a TEM/STEM instrument provides a major improvement in performance relative to one equipped with a LaB6 emitter. The improvement is particularly notable for small-probe techniques: EDX and EELS microanalysis, convergent beam diffraction and scanning. The high brightness of the FEG (108 to 109 A/cm2srad), compared with that of LaB6 (∼106), makes it possible to achieve high probe currents (∼1 nA) in probes of about 1 nm, whilst the currents for similar probes with LaB6 are about 100 to 500x lower. Accordingly the small, high-intensity FEG probes make it possible, e.g., to analyse precipitates and monolayer amounts of segregation on grain boundaries in metals or ceramics (Fig. 1); obtain high-quality convergent beam patterns from heavily dislocated materials; reliably detect 1 nm immuno-gold labels in biological specimens; and perform EDX mapping at nm-scale resolution even in difficult specimens like biological tissue.The high brightness and small energy spread of the FEG also bring an advantage in high-resolution imaging by significantly improving both spatial and temporal coherence.


Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.


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