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.

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.

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.

Newer procedures need to demonstrate efficacy in high complex anal fistulas

Garg Pankaj 대한대장항문학회 2023 Annals of Coloproctolgy Vol.39 No.4

EFFECT OF SUPPLEMENTING UREA MOLASSES MINERAL BLOCK LICK TO STRAW BASED DIET ON DM INTAKE AND NUTRIENT UTILIZATION

Garg, M.R.,Gupta, B.N. Asian Australasian Association of Animal Productio 1992 Animal Bioscience Vol.5 No.1

Twelve male crossbred calves of 18 months of age were divided into two groups of six each. Animals in both the groups were fed wheat straw ad lib. However, animals in group II had free access to urea molasses mineral block (UMMB) lick. Straw DM intake (kg/100 kg B. Wt. and $g/w^{0.75}\;kg$) was significantly (p < 0.01) higher in group II ($1.95{\pm}0.06$; $75.55{\pm}1.79$) as compared to group I ($1.27{\pm}0.08$; $48.77{\pm}2.43$). Straw DM digestibility coefficient was not significantly different in groups I and II. However, DOMI (kg/100 kg B. Wt.) was significantly (p < 0.01) higher in group II ($0.986{\pm}0.05$) as compared to group I ($0.615{\pm}0.03$). Digestibility coefficient of DM, OM and CP were significantly higher in group II as compared to group I. However, digestibility coefficients of EE, CF and NFE were non-significantly different between the two groups. Animals in group II exhibited significantly (p < 0.01) higher and positive N, Ca and P balances as compared to group I which exhibited negative balances. Total-N, ammonia-N and urea-N in the blood plasma of animals in group II were significantly (p < 0.01) higher as compared to group I.

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.

Patient Positioning in Spine Surgery: What Spine Surgeons Should Know?

Garg Bhavuk,Bansal Tungish,Mehta Nishank,Sharan Alok D. 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.4

Spine surgery has advanced tremendously over the last decade. The number of spine surgeries performed each year has also been increasing constantly. Unfortunately, the reporting of position-related complications in spine surgery has also been steadily increasing. These complications not only result in significant morbidity for the patient but also raises the risk of litigation for the surgical and anesthetic teams. Fortunately, most position-related complications are avoidable with basic positioning knowledge. Hence, it is critical to be cautious and take all necessary precautions to avoid position-related complications. We discuss the various position-related complications associated with the prone position, which is the most commonly used position in spine surgery, in this narrative review. We also discuss the various methods for avoiding complications. Furthermore, we briefly discuss less commonly used positions in spine surgery, like the lateral and sitting positions.

Hyperosmotic polydixylitol for crossing the blood brain barrier and efficient nucleic acid delivery

Garg, P.,Pandey, S.,Seonwoo, Hoon,Yeom, Seungmin,Choung, Yun-Hoon,Cho, Chong-Su,Choung, Pill-Hoon,Hoon Chung, Jong The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.17

<P>Here, we introduce a polydixylitol based highly osmotic polymer that not only transmigrates the BBB by intra-arterial infusion of osmotic polyol but also triggers cellular uptake <I>via</I> modulation of caveolae mediated endocytosis.</P> <P>Graphic Abstract</P><P>We report that the incorporation of a hyperosmotic molecule, dixylitol, into the backbone of a delivery vector can enhance its blood brain barrier transmigration. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cc09871d'> </P>

EFFECT OF SUPPLEMENTING UREA MOLASSES MINERAL BLOCK LICKS ON BACTERIAL PRODUCTION RATE IN THE RUMEN OF CROSSBRED CALVES

Garg, M.R.,Gupta, B.N. Asian Australasian Association of Animal Productio 1992 Animal Bioscience Vol.5 No.3

Sixteen crossbred (Sahiwal $\times$ Holstein) male rumen fistulated calves of 18 to 24 months of age were randomly divided into four groups of four animal, each. Animals in all the groups were fed wheat straw ad lib as basal roughage. However, the animals in group I were fed concentrate mixture at maintenance level, whereas, the animals in groups II, III and IV had free access to existing, modified (A) and modified (B) urea molasses mineral block licks respectively. Daily wheat straw intake (kg) was significantly (p<0.01) higher in groups II ($4.20{\pm}0.13$), III ($4.07{\pm}0.16$) and IV ($4.22{\pm}0.20$) as compared to group I ($3.21{\pm}0.14$). Total N and TCA precistrained rumen liquor) was significantly higher in groups II ($22.36{\pm}0.25$), III ($21.63{\pm}0.25$) and IV ($21.77{\pm}0.55$) as compared to group I ($18.31{\pm}0.41$). Bacterial production rate (g/day and g/kg digestible organic matter intake) were non-significantly different amongst groups I ($214.4{\pm}13.28;\;85.38{\pm}3.69$); II ($198.7{\pm}5.70;\;86.17{\pm}3.53$); III ($214.4{\pm}8.19;\;96.15{\pm}2.16$) and IV ($218.2{\pm}10.62;\;94.44{\pm}5.52$). Similarly, percent efficiency of N incorporation into bacterial protein was not found significantly different amongst groups I, II, III and IV. These studies indicate that when concentrate mixture (upto maintenance level) in the diet of ruminants was replaced with UMMB licks, various N fraction in SRL and efficiency of bacterial production rates in the rumen were not affected.