Effect of retempering with retarding admixture on properties of concrete subjected to prolonged mixing

In situations like delivery of concrete from central mixing plant, in road construction, in constructing lengthy tunnels, in transportation of concrete by manual labor, in hilly terrain long hauling of concrete is required. Loss of workability and undue stiffening of concrete may take place at the time of placing on actual work site1. In such situations engineers at site, many a time reject the concrete partially set and unduly stiffened due to the time elapsed between mixing and placing. Mixed concrete is a costly material and it cannot be wasted without any regard to cost. It is required to see whether such a stiffened concrete could be used on work without undue harm with use of retarding admixtures. The process of remixing of concrete, if necessary, with addition of just the required quantity of water is known as ‘retempering’ of concrete1. Sometimes, a small quantity of extra cement is also added while retempering. In the site sometimes the concrete has to wait for some time to enter in the formwork after it is mixed. This may be due to some break down in the conveyance or quarrel between the labors. In such situations the concrete looses its plasticity. But since the quantity is enormous2, such concrete cannot be wasted. In such situations addition of small quantity of cement and water along with retarding admixture can bring back the plasticity to concrete. Thus retempering becomes important in such odd situations2. In this paper an attempt is made to study the strength characteristics of concrete containing retarding admixture at retempering time of 15min upto 90 min. The tests are conducted to evaluate the strength characteristics of concrete like compressive strength, tensile strength, flexural strength for different retempering times

Can we widen the scope of medical management in ectopic pregnancy?

The objective of the study was to Safe Medical management of ectopic pregnancy in those where surgical management was indicated. Patients with one or more criteria not suitable for medical treatment but refusing surgical management were included. Exclusion criteria were those who were not haemodynamically stable. They were managed with close monitoring as inpatient to assess resolution of ectopic with Methotrexate. All five cases have been managed successfully by medical method. There is a possible role for medical management in patients who might not satisfy the criteria fully, however further research is needed. Ectopic pregnancy is life threatening disorder. With advances in diagnostic approaches such as ultrasound coupled with hormone markers diagnosis of ectopic has become easier in cases having first trimester bleeding per vaginum. Ectopic can be managed expectantly, medically and surgically. Medical management includes Inj. Methotrexate (MTX). In this case series we have studied five cases which are managed successfully with hundred percent successful results by medical management despite not satisfying criteria. It is a retrospective study. So from this study we can conclude that we can manage ectopic pregnancies medically based upon clinical judgment

Prediction of tensile strength of concrete produced by using pozzolanic materials and partly replacing natural sand by manufactured sand

The overuse level of cement and natural sand for civil industry has several undesirable social and ecological consequences. As an answer for this, industrial wastes or by-products (pozzolanic materials) such as fly ash, GGBFS, silica fume and metakaolin can be used to interchange partially cement and natural sand by manufacturing sand (M-sand). In this study, Artificial Neural Networks (ANNs) models were developed for predicting the tensile strength, at the age of 28 days, of concretes containing partly pozzolanic materials and partly replacing natural sand by manufactured sand. Tensile strength test were performed and test results were used to construct ANN model. A total of 131 values was used for modeling ANN, 80% in the training phase, and 20% in the testing phase. To construct the model, 25 input parameters were used to achieve one output parameter, referred to as the tensile strength of concrete containing partly pozzolanic materials and manufactured sand. The results obtained in both, the training and testing phases strongly show the potential use of ANN to predict 28 days tensile strength of concretes containing partly pozzolanic materials and manufactured sand

A REVIEW OF ANJANA IN SHALAKYATANTRA

ANJANA The word 'Anjana' is derived from the root.“?????? ???? ??? ?????!”Anjana is a procedure of applying medicine into the inner aspect of lower eyelid.That which spreads in the eye is usually applied from kaninikasandhi to apangasandhi using a shaläka or fingertip.It is the most commonly practised procedure which not only helps in treating eye diseases but also in preventing them

Hypoglycemic effects of Lagenaria siceraria, Cynodon dactylon and Stevia rebaudiana extracts

Introduction: The aim of the current analysis was to judge the hypoglycemic action of the phyto-extracts of Lagenaria siceraria, Cynodon dactylon and Stevia rebaudiana using suitable in vitro approaches. Methods: The hypoglycemic activity of the phyto-material extracts was evaluated by employing various in-vitro methods namely glucose diffusion, amylolysis kinetics and glucose adsorption capacity. Results: The extracts of L. siceraria, C. dactylon and S. rebaudiana exhibited glucose dialysis retardation indices (GDRI) of 48.14%, 37.03% and 29.62%, respectively at 60 minutes which were reduced to 15.78%, 10.52% and 18.42%, respectively at 120 minutes. All the plant extracts used in the study adsorbed glucose and their adsorptions markedly enhanced with increase in sugar concentration. Conclusion: From the outcome of the assay it can be concluded that the extracts of L. siceraria, C. dactylon and S. rebaudiana have hypoglycemic activity as observed in various in-vitro assays. However, the beneficial actions require to be verified by adopting various in vivo techniques along with clinical trials for their efficient use as potential remedial moiety

An ANN to Predict Sorptivity and Water Absorption of Concrete Made with Industrial Waste and Artificial Sand

Large-scale cement and natural fine aggregate use in construction has negative environmental effects. In light of this issue, crushed sand is a good material, and wastes from industries such as metakaolin, Furness ash, blast furnace slag, and micro silica be able to substitute for cement. To estimate the water absorption and sorptivity of concrete made by cementitious waste ingredients and in which the natural fine aggregate is moderately replaced by artificial sand Matlab software model was created in this work.150 mm cube specimen was tested for water absorption and sorptivity. An Artificial neural network (ANN) model was created using the experiment. 330 results in total were used for model design, 20% for neural network model testing check, and 80% results for the Artificial neural network model training phase. The 28-day water absorption and sorptivity of concrete mixed by partially substituting cement with pozzolan and partially substituting natural fine aggregate with artificial sand were calculated using the product of 25 input data. The Artificial neural network model's results offer a precise elastic prediction of the water absorption and sorptivity ability of concrete mixed with substituting industrial cementitious waste for cement and artificial sand with naturally occurring fine aggregate

DESIGN AND FABRICATION OF DUAL AXIS SOLAR TRACKER FOR MAXIMUM ENERGY HARVESTING

Now-a-days we are using static solar panels but this system does not give maximum harvesting of solar energy. In this project, we are presenting the hardware design and implementation of Dual Axis Solar Tracking System that ensures a perpendicular profile of the solar panel with the sun in order to extract maximum energy falling on it. The LDRs do the job of sensing the change in the position of the sun which is dealt by the respective change in the solar panel’s position by switching on and off the DC geared motor. With the implementation of the proposed system the additional energy generated is greater than conventional system with very less consumption by the system itself