Influence of pozzolans on properties of cementitious materials: A review

Garg, Rishav,Garg, Rajni,Eddy, Nnabuk Okon Techno-Press 2021 Advances in nano research Vol.11 No.4

Use of additives/supplementary materials in partial substitution of cement is gaining widespread attention across the world due to the sustainability issue with production of cement. With their pozzolanic activity & filler effect, use of nano-pozzolans such as nano-silica has been proved as quite promising & cost-effective for use as supplementary cementitious materials. This study is aimed at highlighting the effect of partial substitution of cement/addition of various nano-pozzolans on the hydration, strength and microstructure of the cementitious materials. Further, the effect of incorporation of other pozzolans has also been discussed. Comparative account of pozzolanic activity of different pozzolans has also been critically analyzed. It has been found that the cement matrix gets improved in terms of its microstructure by partial substitution of cement/addition of pozzolan in appropriate amount resulting in enhancement of the bulk properties by consumption of portlandite. The improved compressive strength of cementitious materials not only results in enhancement of the durability but also the service life of the construction structures and results in reduction of the cost incurred in maintenance and repair. Thus, the cement demand can be decreased by the partial substitution of cement/addition of such materials. It will result in an ultimate reduction of the greenhouse effect and lead to sustainable development.

Experimental Investigation of Electrochemical Corrosion and Chloride Penetration of Concrete Incorporating Colloidal Nanosilica and Silica Fume

Garg, Rishav,Garg, Rajni,Singla, Sandeep The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.4

Enhancement of durability and reduction of maintenance cost of concrete, with the implementation of various approaches, has always been a matter of concern to researchers. The integration of pozzolans as a substitute for cement into the concrete is one of the most desirable technique. Silica fume (SF) and colloidal nanosilica (CS) have received a great deal of interest from researchers with their significant performance in improving the durability of concrete. The synergistic role of the micro and nano-silica particles in improving the main characteristics of cemented materials needs to be investigated. This work aims to examine the utility of partial substitution of cement by SF and CS in binary and ternary blends in the improvement of the durability characteristics linked to resistance for electrochemical corrosion using electrical resistivity and half-cell potential analysis and chloride penetration trough rapid chloride penetration test. Furthermore, the effects of this silica mixture on the compressive strength of concrete under normal and aggressive environment have also been investigated. Based on the maximum compression strength of the concrete, the optimal cement substituent ratios have been obtained as 12% SF and 1.5% CS for binary blends. The optimal CS and SF combination mixing ratios has been obtained as 1.0% and 12% respectively for ternary blends. The ternary blends with substitution of cement by optimal percentage of CS and SF exhibited decreased rate for electrochemical corrosion. The strength and durability studies were found in consistence with the microstructural analysis signifying the beneficiary role of CS and SF in upgrading the performance of concrete.

Local plus oral antibiotics and strict avoidance of constipation is effective and helps prevents surgery in most cases of anal fissure

Garg Pankaj,Yagnik Vipul D.,Bhattacharya Kaushik 대한대장항문학회 2023 Annals of Coloproctolgy Vol.39 No.2

RECURRENCES FOR THE H-FUNCTION OF TWO VARIABLES

Garg, O.P.,Rastogi, V.K. Department of Mathematics 1982 Kyungpook mathematical journal Vol.22 No.1

Giant Duplication Cyst Presenting as a Discharging Umbilicus

Garg, Ravi Kumar,Bawa, Monika,Rao, Katragadda Lakshmi Narasimha The Korean Society of Pediatric Gastroenterology 2017 Pediatric gastroenterology, hepatology & nutrition Vol.20 No.3

Alimentary tract duplication cysts are rare congenital anomalies, most commonly located in the ileum, but may present anywhere from mouth to anus.Clinically, they may be asymptomatic, incidentally diagnosed or may present with obstruction, volvulus, intussusception or gastrointestinal bleed. Here we report a case of a one year old male child presenting in gasping state and shock. Despite the initial strong suspicion of Meckel's diverticulum and tubercular abdomen, the final diagnosis remained elusive till exploratory laparotomy was performed which revealed a duplication cyst of ileum with perforation into the umbilicus. Duplication cyst should always be kept as a differential diagnosis so that early intervention can help in better management.

Design and simulation of an RCN Controller to improve steady state behavior of a self-excited induction generator

Garg, Anjali,Sandhu, Kanwarjit Singh,Saini, Lalit Mohan Journal of International Conference on Electrical 2012 Journal of international Conference on Electrical Vol.1 No.4

Self-excited induction generators (SEIG) are gaining importance as compared to conventional generators due to their capability toconvert wind energy into electrical energy for a wide range of variation in operating speed. The performance of such a generator depends upon the load, rotor speed and excitation capacitance. Therefore, depending upon the operating conditions, the output voltage and frequency of this machine goes on changing and this imposes a restriction on its usage. In order to maintain constant voltage and frequency, it need controllers, which make the circuit complicated and also increases the overall cost of power generation. This paper presents a simple controller to regulate the output voltage and frequency of SEIG for variation in its operating conditions due to any change in load, rotor speed and excitation capacitance (R, N, C) and their combination. The controller presented is simple in design, user friendly and is also less expensive, as the elements used in the controller are only resistors, inductors and capacitors. A block of SEIG for steady state operation is also modeled and presented in this paper. SEIG, Controller and other components are modeled and simulated using Matlab/Simulink.

Bending analysis of power-law sandwich FGM beams under thermal conditions

Garg, Aman,Belarbi, Mohamed-Ouejdi,Li, Li,Tounsi, Abdelouahed Techno-Press 2022 Advances in aircraft and spacecraft science Vol.9 No.3

Broad writing on the examination of sandwich structures mirrors the significance of incorporating thermal loadings during their investigation stage. In the current work, an endeavor has been made to concentrate on sandwich FGM beams' bending behaving under thermal loadings utilizing shear deformation theory. Temperature-dependent material properties are used during the analysis. The formulation includes the transverse displacement field, which helps better predict the behavior of thick FGM beams. Three-different thermal profiles across the thickness of the beam are assumed during the analysis. The study has been carried out on both symmetric and unsymmetric sandwich FGM beams. It has been observed that the bending behavior of sandwich FGM beams is impacted by the temperature profile to which it is subjected. Power-law exponent and thickness of core also affect the behavior of the beam.

Prevention of Prostate Cancer with Vitamins - Current Perspectives

Garg, Manish,Dalela, Divakar,Goel, Apul,Kumar, Manoj,Sankhwar, Satya Narayan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Cancer prostate is the most common solid malignancy in males of developed countries. With increasing knowledge of the aetiology, pathogenesis and natural history of the disease, influences of dietary factors on prostate cancer development have become more evident. There is ample evidence in the literature of significance of dietary constituents for prostate cancer including vitamins A, D and E. Different vitamins have been found to effect the growth and proliferation of prostate cancer cells as evident in epidemiological, experimental and clinical studies. Various factors play the major role in determining the relationship between these vitamins and prostate cancer in terms of environmental, pharmacological, or genetic aspects. To explore these aspects, the present article reviews the literature on the present status of vitamin use for prevention and management of prostate cancer.

NUTRIENT UTILIZATION, GROWTH RATE AND BODY COMPOSITION OF CROSSBRED CALVES SUPPLEMENTED WITH UREA MOLASSES MINERAL BLOCK LICKS

Garg, M.R.,Gupta, B.N. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.3

Twenty male crossbred ($Sahiwal{\times}HF$) calves of about 6-9 months of age were divided into four groups of five animals each. All the animals were offered wheat straw ad lib. As the basal feed. However, animals in group I were fed concentrate mixture while the animals in groups II, III and IV had free access to urea molasses mineral block (UMMB) lick (I), (II) and (III) respectively as a partial substitute of concentrate mixture. The average concentrate offered (kg/day) to the animals was significantly (p<0.01) higher in group I ($2.69{\pm}0.18$) compared to groups II ($1.76{\pm}0.15$), III ($1.70{\pm}0.06$) and IV ($1.65{\pm}0.12$). The UMMB lick consumed was non-significantly different amongst groups I ($535.40{\pm}38.14$), II ($525.60{\pm}31.82$), III ($551.00{\pm}38.49$) and IV ($548.80{\pm}45.46$). Except ether extract, the digestibility coefficients of CP, ADF and NDF were non-significantly different in different groups. Similarly, N balance (g/day) and percent N retention of intake was not affected in different groups on supplementation of UMMB lick. Body composition of animals was similar in different groups supplemented with either concentrate mixture or concentrate mixture and UMMB licks. It may be concluded from these studies that UMMB lick can partially replace the concentrate mixture in the diet of growing calves without affecting the growth rate, nutrient utilization and body composition. The UMMB lick, thus, can form a part of the ration economically in the diet of growing ruminants especially in developing countries.

Seismic analysis of frame-strap footing-nonlinear soil system to study column forces

Garg, Vivek,Hora, Manjeet S. Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.5

The differential settlements and rotations among footings cannot be avoided when the frame-footing-soil system is subjected to seismic/dynamic loading. Also, there may be a situation where column(s) of a building are located near adjoining property line causes eccentric loading on foundation system. The strap beams may be provided to control the rotation of the footings within permissible limits caused due to such eccentric loading. In the present work, the seismic interaction analysis of a three-bay three-storey, space frame-footing-strap beam-soil system is carried out to investigate the interaction behavior using finite element software (ANSYS). The RCC structure and their foundation are assumed to behave in linear manner while the supporting soil mass is treated as nonlinear elastic material. The seismic interaction analyses of space frame-isolated footing-soil and space frame-strap footing-soil systems are carried out to evaluate the forces in the columns. The results indicate that the bending moments of very high magnitude are induced at column bases resting on eccentric footing of frame-isolated footing-soil interaction system. However, use of strap beams controls these moments quite effectively. The soil-structure interaction effect causes significant redistribution of column forces compared to non-interaction analysis. The axial forces in the columns are distributed more uniformly when the interaction effects are considered in the analysis.