scholarly journals Potential of Portland pozzolana cement in the stabilization of an expansive soil subjected to alternate cycles of wetting and drying

2021 ◽  
Vol 64 (2) ◽  
pp. 81-91
Author(s):  
Jijo James ◽  
Anupriya Natesan ◽  
Aswini Manohar ◽  
Vishvaa Subramanian
Keyword(s):  
Blended Cement ◽  
Expansive Soil ◽  
Industrial Wastes ◽  
Wetting And Drying ◽  
Stabilized Soil ◽  
Ucs Test ◽  
The Common ◽  
Portland Pozzolana Cement ◽  
Better Than

Cement/lime stabilization of soils is one of the common techniques adopted for improving its geotechnical properties. Lately, the focus of investigation has shifted to blended stabilization with industrial wastes as auxiliary additives. However, the role of blended cement in stabilization of soil has been studied insufficiently despite the fact that it is manufactured under controlled conditions. This investigation deals with the use of Portland pozzolana cement (PPC) instead of ordinary Portland cement (OPC) in the stabilization of an expansive soil subjected to alternate cycles of wetting and drying. Unconfined compression strength (UCS) test specimens of dimensions 38mm x 76mm were cast and cured for periods of 7, 14 and 21 days. Then, the specimens were subjected to 1, 2 and 3 cycles of wetting and drying and the UCS of the specimens were determined. Based on the results of the investigation, it was found that OPC performed significantly better than PPC under normal conditions. However, under conditions of wetting and drying, PPC stabilized soil performed much better than OPC stabilized soil when sufficient binder content was available.

scholarly journals Comparative Analysis of In Vitro Responses and Regeneration between Diverse Bioenergy Sorghum Genotypes

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 248
Author(s):  
Barry Flinn ◽  
Savanah Dale ◽  
Andrew Disharoon ◽  
Stephen Kresovich
Keyword(s):  
Plantlet Regeneration ◽  
Induction Phase ◽  
Genetic Studies ◽  
Response Profiles ◽  
The Common ◽  
Parental Lines ◽  
Sorghum Genotypes ◽  
Better Than

Sorghum has been considered a recalcitrant plant in vitro and suffers from a lack of regeneration protocols that function broadly and efficiently across a range of genotypes. This study was initiated to identify differential genotype-in vitro protocol responses across a range of bioenergy sorghum parental lines and the common grain sorghum genotype Tx430 in order to characterize response profiles for use in future genetic studies. Two different in vitro protocols, LG and WU, were used for comparisons. Distinct genotype-protocol responses were observed, and the WU protocol performed significantly better for plantlet regeneration. Most bioenergy genotypes performed as well, if not better than Tx430, with Rio and PI329311 as the top regenerating lines. Genotypes displayed protocol-dependent, differential phenolic exudation responses, as indicated by medium browning. During the callus induction phase, genotypes prone to medium browning exhibited a response on WU medium which was either equal or greater than on LG medium. Genotype- and protocol-dependent albino plantlet regeneration was also noted, with three of the bioenergy genotypes showing albino plantlet regeneration. Grassl, Rio and Pink Kafir were susceptible to albino plantlet regeneration, with the response strongly associated with the WU protocol. These bioenergy parental genotypes, and their differential responses under two in vitro protocols, provide tools to further explore and assess the role of genetic loci, candidate genes, and allelic variants in the regulation of in vitro responsiveness in sorghum.

scholarly journals THE ROLE OF COMPLEMENT IN RESISTANCE TO ENDOGENOUS AND EXOGENOUS INFECTION WITH A COMMON MOUSE PATHOGEN, CORYNEBACTERIUM KUTSCHERI

1966 ◽  
Vol 124 (4) ◽  
pp. 689-699 ◽  
Author(s):  
Linda D. Caren ◽  
L. T. Rosenberg
Keyword(s):  
Survival Advantage ◽  
Mouse Serum ◽  
Equal Frequency ◽  
Laboratory Conditions ◽  
Immune Hemolysis ◽  
The Common ◽  
Deficient Mice ◽  
Normal Laboratory ◽  
Better Than

In mice, the presence or absence of a single complement (C') component, called hc1, is controlled by two alleles at the Hc locus. The sera of mice which lack this C' component do not manifest C'-mediated immune hemolysis. When challenged with the common mouse pathogen, Corynebacterium kutscheri, mice possessing hemolytic C' fare slightly better than C'-deficient mice. When mice harboring latent C. kutscheri are administered hydrocortisone, which depresses mouse serum C' levels, pseudotuberculosis is activated with equal frequency in mice of both C' types. These data suggest that in at least one situation the presence of the complete hemolytic C' system may be advantageous to the mouse. In contrast, evidence is presented which shows that under normal laboratory conditions, C'-deficient B10.D2 "old line" mice (Hc0/Hc0) have a survival advantage over C'-positive B10.D2 "new line" mice (Hc1/Hic1) during the first 3 wk of life. It is therefore concluded that mouse hemolytic C' has a balanced survival value—that is, under one set of conditions it may be advantageous, whereas in another situation, it may be disadvantageous.

scholarly journals Wetting-Drying Resistance of a Lime Stabilized Soil Amended with Steel Slag and Reinforced with Fibres

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jijo James ◽  
Alex Kirubhakaran ◽  
R. Balamurukan ◽  
V. Jawahar ◽  
S.S. Soorya
Keyword(s):  
Steel Slag ◽  
Expansive Soil ◽  
Reinforced Soil ◽  
Specimen Preparation ◽  
Polypropylene Fibres ◽  
Wetting And Drying ◽  
Stabilized Soil ◽  
Filament Content

The investigation dealt with the stabilization of expansive soil with combinations of lime, steel slag and reinforced with two types of fibres, copper filaments and polypropylene fibres. The investigation began with the characterization of the soil for its geotechnical properties. The initial consumption of lime required for the modification of the soil properties was determined from the Eades and Grim pH test. Cylindrical specimens of soil with dimensions 38 mm x 76 mm were cast using this lime content as a stabilizer along with varying quantities of steel slag for determination of optimum steel slag content. The pure lime stabilized soil as well as lime-steel slag modified soil specimens were reinforced with different proportions of copper filaments for determination of optimum fibre content. One dosage of polypropylene fibres was also adopted as reinforcement in specimen preparation. The optimal combinations identified were then subjected to a maximum of three cycles of wetting and drying followed by determination of unconfined compression strength (UCS). The expansive soil required a minimum of 3% lime for its modification. The optimum dosage of steel slag was identified as 5% and optimum copper filament content as 1%. Polypropylene content of 0.3% was also adopted as one combination. The results of the investigation revealed that lime stabilized fibre-reinforced soil with copper filaments was the most durable combination followed by polypropylene fibres. The introduction of steel slag in the mix could not generate enough beneficial durability to the soil after three cycles of wetting and drying.

scholarly journals Valorisation of egg shell ash as a potential replacement for lime in stabilization of expansive soils

2020 ◽  
Vol 63 (3) ◽  
pp. 13-20
Author(s):  
Jijo James ◽  
Priya Jothi ◽  
P. Karthika ◽  
S. Kokila ◽  
V. Vidyasagar
Keyword(s):  
Soil Properties ◽  
Soil Stabilization ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Wetting And Drying ◽  
Lime Content ◽  
Stabilized Soil ◽  
Egg Shell

The investigation focussed on the possibility of replacing lime in soil stabilization using Egg Shell Ash (ESA), a waste derived from poultry industry. An expansive soil was characterized for its properties in the lab. The minimum lime content required for modification of soil properties was determined from the Eades and Grim pH test. This lime content came out to be 3%. The lime content was replaced using ESA in the proportions of 33%, 50%, 67% and 100%. Unconfined compression test specimens of dimension 38 mm x 76 mm were cast for different combinations and were cured for periods of 3, 7 and 28 days. Samples were also subjected to 1, 3 and 5 cycles of wetting and drying to understand its durability. After the designated curing periods and cycles of wetting and drying, they were strained axially till failure. Atterberg limits tests were done to determine the plasticity of the stabilized soil. The strength results indicated that ESA cannot be used under normal conditions as a replacement for lime, however, ESA replacement resulted in good durability of the specimens under conditions of wetting and drying. It was concluded that ESA replacement of lime can be adopted in conditions of wetting and drying.

scholarly journals Expansive soil improvement of Glagahagung village, Purwoharjo sub-district, Banyuwangi district, which is chemically stabilized

2018 ◽  
Vol 195 ◽  
pp. 03009
Author(s):  
Paksitya Purnama Putra ◽  
Diah Ayu Paramiswari ◽  
Abdullah Ilham ◽  
M. Farid Ma’ruf
Keyword(s):  
Local Community ◽  
Soil Stabilization ◽  
Expansive Soil ◽  
Soil Improvement ◽  
Wood Charcoal ◽  
Dry Density ◽  
High Plasticity ◽  
Volume Weight ◽  
Stabilized Soil ◽  
Better Than

Expansive soil can be easily found at Purwoharjo, a sub-district of Banyuwangi. Swelling and shrinkage behavior of the soil is usually referred to by the local community as a “moving soil” phenomenon. It causes cracks on a number of buildings which is a major issue in that area. Various methods of expansive soil stabilization are available. This work intends to lay comparisons on stabilizations using wood charcoal powder and salt. The stabilizing materials are mixed with the soils under different proportion. Volume weight, index properties, and dry density are parameters to be investigated during the stabilization process. The results show that salt stabilized expansive soil is better than wood charcoal powder. 15% proportion of salt to soils weight increases the density by about 20%. Meanwhile, the stabilized soil is as a result of change to low plasticity silt (ML) from previously high plasticity soil (CH) of the original one.

scholarly journals Feasibility of Flyash based Geopolymer for Soil Stabilization

2019 ◽  
Vol 9 (1) ◽  
pp. 4348-4351
Keyword(s):  
Compressive Strength ◽  
Alkaline Solution ◽  
Soil Stabilization ◽  
Stabilizing Agents ◽  
Solid Ratio ◽  
Sample Test ◽  
Stabilized Soil ◽  
Ucs Test ◽  
The Common ◽  
Day By Day

Soil stabilization is the process of enhancing the soil properties and making it fit for engineered purposes. The common stabilizing techniques are becoming expensive day by day due to the rise in cost of stabilizing agents which forces to find an alternative economical stabilizing agent. Thus this study aims to improve the properties of the soil by adding the waste materials like flyash and geopolymers as stabilizing agents. The soil compressive strength and water absorption for different alkaline solution to solid ratio were studied by casting stabilized soil blocks. The solid here is represented by the mixture of red soil and flyash. It was evident from the Unconfined Compressive Strength (UCS) tests that as the alkaline solution to solid ratio increases, the compressive strength also increases. Optimum ratio of 0.2 was selected based on the workability conditions. It was observed that soil blocks show a decrease in 13 per cent strength than the UCS test samples prepared from the same ratio. It is evident to conclude that allowing a tolerance of 1 per cent variation, the strength of the soil blocks will remain in constrain of 12 to 15 per cent of the UCS sample test value.

Scanning Secondary Electron Microscopy of Myofibrils Using Transmission Techniques

1975 ◽  
Vol 33 ◽  
pp. 556-557
Author(s):  
M. K. Lamvik
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Carbon Films ◽  
Photographic Recording ◽  
Transmission Electron ◽  
Thin Carbon ◽  
The Common ◽  
Scanning Electron ◽  
Better Than ◽  
Cellular Organelles

When observing small objects such as cellular organelles by scanning electron microscopy, it is often valuable to use the techniques of transmission electron microscopy. The common practice of mounting and coating for SEM may not always be necessary. These possibilities are illustrated using vertebrate skeletal muscle myofibrils.Micrographs for this study were made using a Hitachi HFS-2 scanning electron microscope, with photographic recording usually done at 60 seconds per frame. The instrument was operated at 25 kV, with a specimen chamber vacuum usually better than 10-7 torr. Myofibrils were obtained from rabbit back muscle using the method of Zak et al. To show the component filaments of this contractile organelle, the myofibrils were partially disrupted by agitation in a relaxing medium. A brief centrifugation was done to clear the solution of most of the undisrupted myofibrils before a drop was placed on the grid. Standard 3 mm transmission electron microscope grids covered with thin carbon films were used in this study.

Examining the Role of Language in Play Among Children With and Without Developmental Disabilities

2020 ◽  
Vol 51 (3) ◽  
pp. 795-806 ◽  
Author(s):  
Elizabeth J. Short ◽  
Rachael Cooper Schindler ◽  
Rita Obeid ◽  
Maia M. Noeder ◽  
Laura E. Hlavaty ◽  
...  
Keyword(s):  
Developmental Disabilities ◽  
Autism Spectrum ◽  
Free Play ◽  
Group Differences ◽  
Typically Developing ◽  
Play Skills ◽  
Critical Aspect ◽  
Hyperactivity Disorder ◽  
Better Than

Purpose Play is a critical aspect of children's development, and researchers have long argued that symbolic deficits in play may be diagnostic of developmental disabilities. This study examined whether deficits in play emerge as a function of developmental disabilities and whether our perceptions of play are colored by differences in language and behavioral presentations. Method Ninety-three children participated in this study (typically developing [TD]; n = 23, developmental language disorders [DLD]; n = 24, attention-deficit/hyperactivity disorder [ADHD]; n = 26, and autism spectrum disorder [ASD]; n = 20). Children were videotaped engaging in free-play. Children's symbolic play (imagination, organization, elaboration, and comfort) was scored under conditions of both audible language and no audible language to assess diagnostic group differences in play and whether audible language impacted raters' perception of play. Results Significant differences in play were evident across diagnostic groups. The presence of language did not alter play ratings for the TD group, but differences were found among the other diagnostic groups. When language was audible, children with DLD and ASD (but not ADHD) were scored poorly on play compared to their TD peers. When language was not audible, children with DLD were perceived to play better than when language was audible. Conversely, children with ADHD showed organizational deficits when language was not available to support their play. Finally, children with ASD demonstrated poor play performance regardless of whether language was audible or not. Conclusions Language affects our understanding of play skills in some young children. Parents, researchers, and clinicians must be careful not to underestimate or overestimate play based on language presentation. Differential skills in language have the potential to unduly influence our perceptions of play for children with developmental disabilities.

On everyday academic research

2017 ◽  
pp. 98-134 ◽  
Author(s):  
J. Tirole
Keyword(s):  
Common Good ◽  
Academic Research ◽  
Research Quality ◽  
Economic Research ◽  
Relevant Research ◽  
The Common ◽  
Verification Of Models ◽  
Science And Research

In the fourth chapter of the book “The economy of the common good”, the nature of economics as a science and research practices in their theoretical and empirical aspects are discussed. The author considers the processes of modeling, empirical verification of models and evaluation of research quality. In addition, the features of economic cognition and the role of mathematics in economic research are analyzed, including the example of relevant research in game theory and information theory.

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