Guar gum-stabilized soil: a clean, sustainable and economic alternative liner material for landfills

The research evaluated the failure susceptibility of biopolymers (Guar Gum, Xanthan Gum, Bentonite) and polyvinyl acetate (PVAc) stabilized soil samples from three failed locations along Oshogbo – Iwo Road’s using the TDRAMS mathematical model formulated by Aderinola et al., (2015). The stabilizers were added to the soils in concentrations of (0.25-2) % Biopolymers, (1-3) % Bentonite and 2% PVAc. The samples were classified according to AASHTO as A-5 (slty-sand) and ML group (inorganic silts, sfine sands with low plasticity) based on USCS classification system. Geotechnical tests carried out on both natural untreated and treated samples showed that the natural soil samples gave OMC values of between (11.7-14.97) %, MDD (1644-1453.6) Kg/m3, and soaked CBR (2-6) %. 1% Guar gum, 1 % Xanthan gum, 3% Bentonite and 2% Poly vinyl Acetate were deduced to be optimal mixes for improved strength. However, Guar gum was observed to be the best stabilizer. With the TDRAMS model, 1% Guar gum reduced the failure susceptibility indices of the road by 11.02 % (i.e. from 127 to 113). However, for maximum benefits to be achieved from the stabilization, other factors like provision of good drainage facilities, adequate road sections etc. must be provided. This will help in improving the strength of the subgrade soils and overall durability of the road.

Download Full-text

Increased dryness after pressing and wet web strength by utilizing foam application technology

TAPPI Journal ◽

10.32964/tj15.11.731 ◽

2016 ◽

Vol 15 (11) ◽

pp. 731-738 ◽

Cited By ~ 1

Author(s):

KARITA KINNUNEN-RAUDASKOSKI ◽

KRISTIAN SALMINEN ◽

JANI LEHMONEN ◽

TUOMO HJELT

Keyword(s):

Tensile Strength ◽

Guar Gum ◽

Paper Industry ◽

Reference Sample ◽

Strength Properties ◽

Cellulose Microfibrils ◽

Application Technology ◽

Ethylene Vinyl Alcohol ◽

Wet Pressing ◽

Web Strength

Production cost savings by lowering basis weight has been a trend in papermaking. The strategy has been to decrease the amount of softwood kraft pulp and increase use of fillers and recycled fibers. These changes have a tendency to lower strength properties of both the wet and dry web. To compensate for the strength loss in the paper, a greater quantity of strength additives is often required, either dosed at the wet end or applied to the wet web by spray. In this pilot-scale study, it was shown how strength additives can be effectively applied with foam-based application technology. The technology can simultaneously increase dryness after wet pressing and enhance dry and wet web strength properties. Foam application of polyvinyl alcohol (PVA), ethylene vinyl alcohol (EVOH), carboxymethyl cellulose (CMC), guar gum, starch, and cellulose microfibrils (CMF) increased web dryness after wet pressing up to 5.2%-units compared to the reference sample. The enhanced dewatering with starch, guar gum, and CMF was detected with a bulk increase. Additionally, a significant increase in z-directional tensile strength of dry web and and in-plane tensile strength properties of wet web was obtained. Based on the results, foam application technology can be a very useful technology for several applications in the paper industry.

Download Full-text

Predicting Desiccative Degradation of Stabilized Soil Using Regressive Models

International Conference on Earth, Environment and Life sciences (EELS-2014) Dec. 23-24, 2014 Dubai (UAE) ◽

10.15242/iicbe.c1214092 ◽

2014 ◽

Keyword(s):

Stabilized Soil

Download Full-text

Formulation and Evaluation of Microbially- triggered tablets of Valdecoxib

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v2i1.8841 ◽

2010 ◽

Vol 2 (1) ◽

Author(s):

Surender Verma ◽

S. Singh ◽

D. Mishra ◽

Atul Gupta ◽

Rakesh Sharma

Keyword(s):

Phosphate Buffer ◽

Guar Gum ◽

Oral Route ◽

Matrix Tablets ◽

In Vitro Dissolution ◽

Wet Granulation ◽

Dissolution Study ◽

Caecal Content ◽

Model Drug

The objective of present study was to develop colon targeted drug delivery using bacterially triggered approach through oral route. Valdecoxib (COX-2 inhibitor) was chosen as a model drug in order to target it to colon which may prove useful in inflammatory bowel disease and related disorders. Matrix tablets of Valdecoxib were prepared by wet granulation technique utilizing different ratio of Guar gum and Sodium starch glycholate. The prepared matrix tablets were evaluated for uniformity of weight, uniformity of content, hardness and in vitro dissolution study in simulated gastric and intestinal fluid (Phosphate Buffer pH-1.2, pH-6.8 and pH-7.4), followed by Dissolution study in bio-relevant dissolution media Phosphate Buffer (pH-6.8) containing rat caecal content. The results revealed that the formulated batch had released lesser quantity of drug at pH 1.2 and pH 7.4 in 2 hors whereas in biorelevent dissolution media containing rat caecal content it released significantly higher amount of drug which was also significantly higher than the dissolution media of same pH without caecal content (microflora) and it was concluded that guar gum can be used as a potential carrier for targeting drugs to colon.

Download Full-text

pH Dependent Release Potential of Natural Polymers in Sustained Release of Ornidazole From Colon Targeted Delivery System)

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.9.2.4 ◽

2019 ◽

Vol 9 (02) ◽

Author(s):

Sharma Pankaj ◽

Tailang Mukul

Keyword(s):

Drug Release ◽

Delivery System ◽

Targeted Delivery ◽

Guar Gum ◽

Acidic Environment ◽

Natural Polymers ◽

Weight Variation ◽

Curve Determination ◽

Preformulation Studies

The aim of present work was to prepare colon specific delivery system of Ornidazole using different ratio of shellac, zein and guar gum. From study of various literature it revealed that shellac, zein and guar gum released drug from dosage form at the pH of 6.9, 11.5, 7-9 respectively. The main problem associated with colon targeted drug delivery system is degradation of drug in the acidic environment of stomach to circumvent the present problem different combinations of shellac, zein and guar gum were employed in the formulation of colon targeted tablet. Several preformulation parameters were determined such as melting point, FTIR spectroscopy, preparation of calibration curve, determination of λmax and partition coefficient. After the preformulation studies, next steps were preparation of core tablets, evaluation of core of tablets and coating of tablets. The data obtained from preformulation study seven formulations were developed and evaluated for various parameters. Based on evaluated parameter such as weight variation, friability, dissolution study, invitro drug release etc. the F7 formulation show better results colon targeted tablets. Drug content in F7 formulation was 95% and drug release after 6 hrs was 96%. Formulation containing combination of shellac, zein and guar gum released least amount of drug in the acidic environment of stomach and released most of the drug in colon. It is evide

Download Full-text

Ru Passivated and Ru Doped e-TaN surfaces as Combined Barrier and Liner Material for Copper Interconnects: A First Principles Study

10.26434/chemrxiv.7427867 ◽

2018 ◽

Author(s):

Suresh Natarajan ◽

Cara-Lena Nies ◽

Michael Nolan

Keyword(s):

First Principles ◽

Film Growth ◽

Early Stage ◽

Copper Interconnects ◽

Liner Material ◽

Critical Dimensions ◽

Industry Standard ◽

Cu Film ◽

Improved Performance ◽

And Diffusion

<div>As the critical dimensions of transistors continue to be scaled down to facilitate improved performance and device speeds, new ultrathin materials that combine diffusion barrier and seed/liner properties are needed for copper interconnects at these length scales. Ideally, to facilitate coating of high aspect ratio structures, this alternative barrier+liner material should only consist of one or as few layers as possible. We studied TaN, the current industry standard for Cu diffusion barriers, and Ru, which is a</div><div>suitable liner material for Cu electroplating, to explore how combining these two materials in a barrier+liner material influences the adsorption of Cu atoms in the early stage of Cu film growth. To this end, we carried out first-principles simulations of the adsorption and diffusion of Cu adatoms at Ru-passivated and Ru-doped e-TaN(1 1 0) surfaces. For comparison, we also studied the behaviour of Cu and Ru adatoms at the low index surfaces of e-TaN, as well as the interaction of Cu adatoms with the (0 0 1) surface of hexagonal Ru. Our results confirm the barrier and liner properties of TaN and Ru, respectively while also highlighting the weaknesses of both materials. Ru passivated TaN was found to have improved binding with Cu adatoms as compared to the bare TaN and Ru surfaces.</div><div>On the other hand, the energetic barrier for Cu diffusion at Ru passivated TaN surface was lower than at the bare TaN surface which can promote Cu agglomeration. For Ru-doped TaN however, a decrease in Cu binding energy was found in addition to favourable migration of the Cu adatoms toward the doped Ru atom and unfavourable migration away from it or into the bulk. This suggests that Ru doping sites in the TaN surface can act as nucleation points for Cu growth with high migration barrier preventing agglomeration and allow electroplating of Cu. Therefore Ru-doped TaN is proposed as a candidate for a combined barrier+liner material with reduced thickness.</div>

Download Full-text

Colon targeting oral matrix tablets of mesalamine: Design, development and invitro evaluation

International Journal of Novel Trends in Pharmaceutical Sciences ◽

10.26452/ijntps.v10i1.1144 ◽

2020 ◽

Vol 10 (1) ◽

pp. 18-27

Author(s):

Audinarayana N ◽

Anala Srinivasulu ◽

Vellore Sruthikumari ◽

Likitha ◽

Ananda Deepak V

Keyword(s):

Drug Release ◽

Guar Gum ◽

Stability Study ◽

Matrix Tablets ◽

Drug Dissolution ◽

Matrix Tablet ◽

Cellulose Acetate Phthalate ◽

Design Development ◽

Release Pattern ◽

The Matrix

The principle in this present research is to formulate Mesalamine containing colon targeted tablets by using different polymers and evaluate the effect of different polymers in drug release pattern. The matrix tablets of Mesalamine are formulated by polysaccharides based polymers like Cellulose acetate phthalate (CAP), Ethyl cellulose (EC), Guar gum (GG) and Xanthan gum (XG) which protects the drug to release in Stomach and Small Intestine. The invitro drug dissolution investigation of F2 (GG and XG) Matrix tablet was controlled by swelling into a viscous gel in colonic pH, which have been accomplished as the best tablet. The optimized tablet F2 was found to be stable in stability study (short term) with reproducible evaluation data, which also shows the highest swelling index, increased viscosity in colonic pH. The drug release pattern from the F2 formulation follows swelling and erosion behavior. From the data it show that F2 tablets suitable for providing colon targeted drug delivery.

Download Full-text

PERILAKU DISOLUSI KETOPROFEN DAN INDOMETASIN FARNESIL TERSALUT GEL KITOSAN-GOM GUAR

Jurnal Sains dan Teknologi Indonesia ◽

10.29122/jsti.v12i1.849 ◽

2012 ◽

Vol 12 (1) ◽

Author(s):

Purwantiningsih Sugita ◽

Bambang Srijanto ◽

Budi Arifin ◽

Fithri Amelia ◽

Mahdi Mubarok

Keyword(s):

Room Temperature ◽

Guar Gum ◽

Tween 80 ◽

Chitosan Solution ◽

In Vitro Dissolution ◽

Dissolution Profile ◽

Magnetic Stirrer ◽

Dissolution Behaviour ◽

Shrimp Shell Waste

Chitosan, a modification of shrimp-shell waste, has been utilized as microcapsule. However, it’s fragile gel property needs to be strengthened by adding glutaraldehyde (glu) and natural hydrocolloid guar gum (gg). This research’s purposes were to study dissolution behaviour of ketoprofen and infar through optimum chitosan-guar gum microcapsule. Into 228.6 mL of 1.75% (w/v) chitosan solution in 1% (v/v) acetic acid,38.1 mL of gg solution was added with concentration variation of 0.35, 0.55, and 0.75% (w/v) for ketoprofen microcapsules and 0.05, 0.19, and 0.33% (w/v) for infar microcapsules, and stirred with magnetic stirrer until homogenous. Afterwards, 7.62mL of glu was added slowly under stirring, with concentrations varied: 3, 3.5, and 4% (v/v) for ketoprofen microcapsules, and 4, 4.5, and 5% (v/v) for infar microcapsules. All mixtures were shaked for 20 minutes for homogenization. All mixtures wereshaked for 20 minutes for homogenization. Into each microcapsule mixture for ketoprofen, a solution of 2 g of ketoprofen in 250 mL of 96% ethanol was added, whereas solution of 100 mg of in 250 mL of 96% ethanol was added into each microcapsule mixture for infar. Every mixture was then added with 5 mL of 2% Tween-80 and stirred with magnetic stirrer for an hour at room temperature. Everymixture was then added with 5 mL of 2% Tween-80 and stirred with magnetic stirrer for an hour at room temperature. Conversion of suspension into fine powders/granules (microcapsules) was done by using spray dryer. The data of [gg], [glu], and medicine’s content from each microcapsule were treated with Minitab 14 software to obtain optimum [gg] and [glu] for microencapsulation. The dissolution behaviour of optimum ketoprofen and infar microcapsules were investigated. The result of optimization by using Minitab Release 14 software showed that among the microcapsule compositions of [gg] and [glu] were 0.35% (w/v) and 3.75% (v/v), respectively, optimum to coat ketoprofen, whereas [gg] and [glu] of 0.05% (w/v) and4.00% (v/v), respectively, optimum to coat infar, at constant chitosan concentration (1.75% [w/v]). In vitro dissolution profile showed that chitosan-guar gum gel microcapsule was more resistant in intestinal pH condition (rather basic) compared with that in gastric pH (very acidic).

Download Full-text