Molar Sodium Hydroxide Research Articles

Study on the physical and mechanical properties of Alkali-Activated concrete bricks

Alkali-activated concrete (AAC) has shown high potential as a replacement for ordinary Portland cement concrete (OPCC). It has been found that fresh AAC is usually dry and difficult to control during the casting process, as well as having flash setting issues. In light of the lack of a final form for the use of AAC in construction, there is a need to discover applications that benefit from the advantages of AAC while also being able to deal with its drawbacks. This paper will focus on taking advantage of AAC's defects by using it in a nonstructural application that does not require high-workability concrete, such as producing bricks. Waste from the iron industry was used as the main component for producing the AAC bricks in order to reduce the environmental impact, reduce the cost, and save large quantities of cement and natural aggregates consumed by the brick industry. Ground granulated blast furnace slag (GGBFS) and electric arc furnace slag (EAFS) were substituted for cement and aggregates, mixed along with an alkaline solution and superplasticizer. AAC bricks were produced in the same way as normal concrete bricks. The physical and mechanical properties studied were compressive strength, water absorption, bulk density, efflorescence, and drying shrinkage. Six parameters were considered throughout this investigation. The effects of binder content, cement replacement ratio, alkaline-to-binder ratio, sodium silicate/sodium hydroxide mass ratio, sodium hydroxide molarity, and compaction pressure. The results showed that compared to ordinary bricks, AAC bricks provided high compressive strength up to 92 MPa, up to 54% less water absorption, a density of more than 2.8 t/m3, and a higher drying shrinkage up to 0.002 mm. Furthermore, no signs of efflorescence or salts appeared on the bricks.

An improved digestion and analysis procedure for silicon in plant tissue.

Silicon (Si) in plant tissues reduces abiotic and biotic stress, but it is incorporated as silica (SiO2), which is difficult to solubilize for analysis. We modified an oven-induced tissue-digestion and analysis method to improve Si solubilization and validated its accuracy by quantifying the mass-balance recovery of Si from the hydroponic solution and plant tissues of cucumber (Cucumis sativus). Leaf, stem, and root tissues were dried, finely-ground, and digested in 12.5 molar sodium hydroxide at 95°C for 4 hours. Solutions were then acidified with 6 molar hydrochloric acid to achieve a pH below 2 for measurement of Si using the molybdate blue colorimetric method. Interference of phosphorus in the analysis was minimized by increasing the addition of oxalic acid from 0.6 to 1.1 molar. We recovered 101% ± 13% of the expected Si, calculated using mass-balance recovery, in leaf, stem, and root tissues across 15 digestions. This Si recovery was fourteen-fold higher than the standard acid-extraction method and similar to a USDA-ARS alkaline-extraction method. Our procedure offers a low-cost, accurate method for extraction and analysis of Si in plant tissues.

Effect of ceramic waste powder content and sodium hydroxide molarity on the residual mechanical strength of alkali-activated mortars

In the study, the effects of various ceramic waste powder (CWP) additions (5, 10, and 15%) and sodium hydroxide (SH) molarity (8 M and 16 M) on the residual mechanical properties of different ambient-cured alkali-activated mortar (AAM) samples were investigated under the elevated temperatures (300, 600, and 900 °C) and freeze-thaw (100 cycles) attacks. The fresh (flowability, initial and final setting time, water absorption, and void ratio) and hardened (compressive and flexural strength, ultrasonic pulse velocity, and weight loss) state performances were evaluated. Also, XRD and SEM analyses were carried out. The findings pointed out that flowability enhanced up to 15% of CWP replacements. The initial and final setting time was reduced with higher molarity, while improved with further CWP incorporations. The water absorption and void ratio decreased with higher CWP incorporations and SH molarity. Moreover, mechanical strengths increased with time, which were found to be more with a higher CWP replacement ratio and SH molarity. After elevated temperature, the average compressive strength losses were about 50% at 600 °C and 85% at 900 °C, while average flexural strength losses were about 70% at 600 °C and 85% at 900 °C. Meanwhile, similar residual compressive strengths were obtained at elevated temperatures, irrespective of the SH molarity and CWP incorporations. However, both CWP incorporation and high SH molarity slightly enhanced the residual flexural strengths. After freeze-thaw attacks, an average of 23% compressive strength loss and 29% flexural strength loss was obtained, and almost similar mechanical strength losses were observed with varying SH molarity and CWP replacement ratio.

AN INVESTIGATION ON THE PROPERTIES OF GEOPOLYMER LIGHT WEIGHT CONCRETE

The large-scale production of cement is posing environmental problems on one hand and unrestricted depletion of natural resources, on the other hand causing greenhouse effect and global warming. Each ton of Portland cement production results in loading about one ton of CO2 in to the environment. Environmental and economic reasons require the vision of present concrete making materials. Fortunately in such scenario a new material has emerged that can help in mitigating the problem and the material is Geopolymer Concrete. Hence, the present research work is focused on the production of geopolymer concrete using pozzolans. Geopolymer concrete donot use cement in its productive. Materials like fly ash, ground granulated blast furnace slag (GGBS), silica fume, etc may be used as pozzolanes. The parameters influencing strength of GPC are total combined aggregate, alkaline to binder ratio, mass of sodium silicate to sodium hydroxide, molarity of sodium hydroxide and curing conditions. The main objective of this experimental investigation is to produce geopolymer concrete using industrial wastes such as fly ash to reduce the global warming effect. The industrial waste foundry slag is used as partial replacement with coarse aggregate in various percentages such as 0%, 20%, 40%, 60%, 80% and 100% by weight. Specimens are prepared with 13 molarity, with alkaline to binder ratio as 0.35 and with mass of Na2SiO3 to NaOH as 2.0. The specimens are kept for ambient curing for required days. The workability tests such as slump test, vee-bee test and compaction factor test are conducted. The mechanical properties are studied by testing for compressive strength, tensile strength and flexural strength. Durability properties like water absorption, sorpitivity tests are carried out. The test results showed the ability of producing light weight geopolymer concrete with acceptable performance of strength and durability properties. Key Words: Geopolymer concrete, Light weight aggregate, waste foundry slag, alkaline solution, sorpitivity.

Development of bio-based blended ash and fly ash-based alkali-activated concrete

Owing to rapid industrialisation and urbanisation there has been a significant increase in the manufacture and application of cement, resulting in high carbon dioxide (CO2) emissions into the atmosphere. This paper investigates alternative binders that have reduced carbon dixoide emissions and better performance. The study elaborates the mix design of novel concrete, wherein the principle raw material used was locally available bio-based blended ash (BA) procured from the co-combustion process with sodium-based alkali activators. The physical, chemical, mineral and morphological characteristics of BA were studied. Beside this, the influence of parameters such as molarity of sodium hydroxide (NaOH), liquid sodium silicate (LSS) to NaOH ratio, fly ash (FA) to BA ratio and method of curing on the physico-mechanical properties of alkali-activated concrete as a sustainable construction material were studied. Higher characteristic strength was attained with an increase in these parameters. A maximum characteristic strength of 42.31 MPa at day 28 was obtained with 8 M NaOH, LSS/NaOH ratio of 1.5 and FA/BA ratio of 3. The average flexural and split tensile strength obtained were 3.70 and 2.72 MPa, respectively. The experimental investigation of the alkali-activated concrete using BA and FA proved to be an efficient solution for zero-cement concrete with improved performance.

Mechanical and Microstructural Properties of Rubberized Geopolymer Concrete: Modeling and Optimization

The construction industry is increasingly focused on sustainability, with a particular emphasis on reducing the environmental impact of cement production. One approach to this problem is to use recycled materials and explore eco-friendly raw materials, such as alumino-silicate by-products like fly ash, which can be used as raw materials for geopolymer concrete. To enhance the ductility, failure mode, and toughness of the geopolymer, researchers have added crumb rubber processed from scrap tires as partial replacement to fine aggregate of the geopolymer. Therefore, this study aims to develop rubberized geopolymer concrete (RGC) by partially replacing the fine aggregate with crumb rubber (CR). To optimize the mechanical properties of RGC, response surface methodology (RSM) has been used to develop 13 mixes with different levels and proportions of CR (10–30% partial replacement of fine aggregate by volume) and sodium hydroxide molarity (10–14 M) as input variables. The results showed that the strength properties increased as the molarity of NaOH increased, while the opposite trend was observed with CR. The maximum values for compressive strength, flexural strength, and uniaxial tensile strength were found to be 25 MPa, 3.1 MPa, and 0.41 MPa, respectively. Response surface models of the mechanical strengths, which were validated using ANOVA with high R2 values of 72–99%, have been developed. It has been found that using 10% CR with 14 M sodium hydroxide resulting in the best mechanical properties for RGC, which was validated with experimental tests. The result of the multi-objective optimization indicated that the optimum addition level for NaOH is 14 M, and the fine aggregate replacement level with CR is 10% in order to achieve a rubberized geopolymer suitable for structural applications.

The effect of sodium hydroxide molarity on setting time, workability, and compressive strength of fly ash-slag-based geopolymer mortar

This research investigates the influence of sodium hydroxide (SH) molarity on fly ash-slag-based geopolymer mortar’s workability, setting time, and compressive strength. The molarity of SH varies between 1M, 2M, 4M, 6M, 8M, and 10M. The geopolymer mixture was proportioned to contain 30% slag as a substitution for fly ash, with the alkaline activator to binder (Al/Bi) ratio of 0.45 and the sodium silicate to sodium hydroxide ratio (SS/SH) of 1.5. The results showed that at a range of low molarity SH (1M, 2M, and 4M), the setting time was faster in a mixture containing higher molarities. In contrast, at a range of high molarity (6M, 8M, and 10M), the setting time is slower in a mixture with higher molarity SH. Based on the setting time, the concentration of SH that can be applied in the field is 1M, 2M, 8M, and 10M. Increasing the molarity of SH will decrease the workability but increase compressive strength. However, when SH molarity increased after optimal molarity was established, the compressive strength was reduced. The maximum compressive strength of mortar is 46.86 MPa, obtained at an SH molarity of 6M.

Effect of curing conditions on the compressive strength of fly ash-based geopolymer concrete

The utilization of Ordinary Portland Cement (OPC) in concrete construction has led to significant environmental concerns, including the depletion of natural resources and the release of CO2 emissions during its production. To address these issues, the development of cement-less concrete known as geopolymer concrete (GPC) offers a promising solution. GPC can be produced by utilizing industrial waste materials, thereby promoting environmental sustainability. In this study, fly ash, an industrial waste, was used as a key component in the production of GPC.The research focused on investigating the effects of various variables on the workability and compressive strength of GPC. Specifically, the molarity of sodium hydroxide (NaOH) solutions (6 M, 9 M, 12 M, and 14 M), curing temperatures (30 °C, 60 °C, and 90 °C), and curing periods (7, 14, and 28 days) were examined. The performance of GPC was compared to that of OPC-based control concrete.The results obtained from the experiments exhibited promising outcomes, highlighting the potential of fly ash-based GPC as an alternative to OPC-based concrete. The study revealed that GPC achieved desirable workability and compressive strength when subjected to specific combinations of the examined variables.By utilizing fly ash as an industrial waste material, GPC not only addresses environmental concerns associated with OPC but also contributes to sustainable construction practices. The findings of this study provide valuable insights into the feasibility of utilizing fly ash-based GPC as a viable alternative to OPC-based concrete, emphasizing its potential for reducing environmental impact in the construction industry.

Mechanical Behaviour of Geopolymer Concrete Using Steel Fibers

This investigation inspects the concurrent influence of steel fibers with different materials such as Fly Ash(FA), Silica Fume(SF) and aggregates on the mechanical behaviour of geopolymer concrete (GPC) mixes. A range of 8 to 16 molar NaOH molarities variation was observed in the experimental work. Sodium hydroxide molar (NaOH) and sodium silicate solution (NaOH) were utilised as alkaline activators in proportions of 1, 1.5, and 2 (Na2SiO3/NaOH). Steel crimped fibers having aspect ratio of 60 were added in the geopolymer concrete. Geopolymer concrete properties considering type of fly ash, the quantity of fly ash, silica fume, the content of fine aggregate and coarse aggregate, effect of sodium hydroxide concentration, content of sodium silicate solution and inclusion of 0.2% of steel fibers in the geopolymer concrete are analyzed.

Effects of functionalization and silane modification of hexagonal boron nitride on thermal/mechanical/morphological properties of silicon rubber nanocomposite

Hexagonal boron nitride (h-BN) nanoparticles could induce interesting properties to silicone rubber (SR) but, the weak filler-matrix interfacial interaction causes agglomeration of the nanoparticles and declines the performance of the nanocomposite. In this work, h-BN nanoparticles were surface modified using vinyltrimethoxysilane (VTMS) at different concentrations. Before silane modification, h-BN nanoparticles were hydroxylated using 5 molar sodium hydroxide. The nanoparticles were characterized to assess success of silane grafting. The pure and modified h-BN nanoparticles were applied at 1, 3 and 5 wt% to HTV silicon rubber (SR). The curing, thermal, mechanical and morphological properties and hydrophobicity of the nanocomposites were evaluated. The morphology of the SR nanocomposites was characterized using AFM and FE-SEM analysis. It was found that silane grafting on the h-BN nanoparticles improves crosslink density but declines curing rate index (CRI) of the SR nanocomposite (at 5 wt% loading content) by 0.7 (dN m) and 3.5%, respectively. It also increased water contact angle of the nanocomposites from 97.5° to 107°. The improved nanoparticle-rubber interfacial interactions caused better dispersion of h-BN nanoparticles in SR matrix (at 5 wt%) that enhanced the elongation at break, modulus at 300% and Tg of the SR nanocomposites.

Influence of GGBFS-based blended precursor on fresh properties of self-compacting geopolymer concrete under ambient temperature

Geopolymer concrete having self-compacting nature is known as self-compacting geopolymer concrete (SCGC) which does not need mechanical compaction to improve the concrete density. The geo-polymerization process primarily depends on aluminosilicate materials and alkaline activator solution (AAS). The type of precursor material greatly affects the hardened concrete properties i.e. both the short-term and long-term concrete characteristics. The present study aims to achieve an optimal blended precursor-based SCGC possing acceptable fresh property characteristics where ground granulated blast furnace slag (GGBFS), the precursor in the control GGBFS-based SCGC is partially replaced by silica fume (SF), and rice husk ash (RHA) with various proportions. Mix proportions with the replacement of GGBFS by SF (10%, 20%, 30%, 40%) and RHA (5%, 10%, 15%, 20%) are prepared along with one control GGBFS-based SCGC. The fresh property of the nine SCGC mixes are interpreted through the filling ability (slump flow, T50cm slump, V-funnel); passing ability (L-box, J-ring), and resistance to segregation (V-funnel at T5minutes) test. All the ambient temperature-cured SCGCs are made with the following mix parameters: 12 M sodium hydroxide molarity, AAS ratio of 2.5, superplasticizer dose of 7%, and extra water of 24%.

Gas/Liquid Operations in the Taylor-Couette Disc Contactor: Continuous Chemisorption of CO2

Gas/liquid contactors are widely used in chemical and biotechnological applications. The selection and design of bubble-column-type gas/liquid contactors requires knowledge about the gas distributor design to provide appropriate gas flow patterns. This study presents the continuous chemisorption of CO2 in 0.1 molar sodium hydroxide solution in a counter currently operated gas/liquid Taylor-Couette disc contactor (TCDC). This vertical-column-type contactor is a multi-stage agitated gas/liquid contactor. The performance of a lab-size TCDC contactor in gas/liquid mass transfer operations was investigated. The apparatus design was adjusted for gas/liquid operations by installing perforated rotor discs to provide a rotational-speed-dependent dispersed gas phase holdup in the column. The parameters of dispersed gas phase holdup, volumetric mass transfer coefficient and residence time distribution were measured. In the first step, hydraulic characterization was performed. Then, the efficiency in gas/liquid operations was investigated by continuous neutralization of 0.1 molar sodium hydroxide with a gas mixture of 30 vol% CO2 and 70 vol% N2. Temperature, rotational speed and gas flow rate were varied. The desired pH value of pH 9 at the column outlet was kept constant by adjusting the sodium hydroxide feed. From the experimental results, the volume-based liquid-side mass transfer coefficient kLa was deduced in order to model the reaction according to the two-film theory over the column height. The CSTR cascade model fitted the experimental data best. The experimental results confirm stable and efficient reactive gas/liquid contact in the Taylor-Couette disc contactor.

Use of waste glass powder toward more sustainable geopolymer concrete

The influence of waste glass powder (WGP) with fly ash in certain proportions on geopolymer concrete (GPC) was investigated by exchanging different proportions of molarity and WGP percentages in GPC. For this objective, fly ash was altered with WGP having percentages of 10%, 20%, 30%, and 40%, and the effect of molarity of sodium hydroxide (NaOH) was examined. The compressive strength tests, splitting tensile tests, and flexural strength tests were conducted. The workability and setting time were also evaluated. With the addition of WGP, the workability for molarities (M) of 11, 13, and 16 NaOH reduced by an average of 17%, 10%, and 67%, respectively. The findings showed that the slump values decreased as the molarity and WGP percentages increased. Molarity significantly affected the setting time, but WGP had no effect on the setting time. Although high molarity increased the capacity, this had a noticeable negative effect on the setting time and workability. This study demonstrated that WGP had a slight negative effect on the capacity and workability. Furthermore, when the combined effects of WGP and NaOH molarity were taken into account, the use of 10% WGP with M13 NaOH was recommended to obtain the optimum sustainable GPC considering both fresh and hardening properties. Scanning electron microscopy (SEM) analysis was done on the samples, too.

Mechanical and bond behaviour of high volume Ultrafine-slag blended fly ash based alkali activated concrete

The development of Geopolymer concrete (GPC) mixes by employing large volume of ultrafine ground granulated blast furnace slag (UBFS) blended with Fly ash (FA) and activated by sodium hydroxide (SH) has been presented in this study. Several GPC mixes has been prepared to investigate the effect of varying alkali content, fine aggregate to total aggregate ratio (s/a) and molar concentration (M) of alkali activator on the fresh and hardened characteristics, including the bond strength with Portland cement concrete (PCC). The properties of the GPC mixes are assessed by workability test, compressive strength test, split tensile strength test and slant shear test, including the microstructure through FESEM (Field Emission Scan Electron Microscopy) and X-ray diffraction (XRD). The test result shows that s/a ratio is a crucial factor in controlling segregation and bleeding in GPC. However, an ideal GPC mix with s/a ratio 0.41 provides a better packing resulting in improved mechanical properties. Application of high volume UBFS in the GPC exhibits better reaction products as shown by the microstructure at a relatively lower alkali concentration which ultimately leads to higher strength. Superior bond strength is achieved between the GPC and old PCC substrate; however, the molarity of SH significantly affects the adhesion property of GPC.

Effect and influence of GGBS on properties of ambient cured self-compacting geopolymer concrete

The sustainable manufacture of self-compacting geopolymer concrete (SCGC), which has a lower carbon footprint compared with traditional concrete, reflects environmentally friendly concrete. In addition to the physical properties, this article presents an analysis of the fresh and mechanical properties of self-compacting geopolymer concrete. Some parameters such as varied sodium hydroxide molarity from 8 M to 16 M, sodium hydroxide/silicate solution ratio from 1:2.5 alkaline to GGBS, extra water ratio, GGBS content from 400 Kg/m3 to 500 Kg/m3. The current experimental evaluation examines the effectiveness of GGBS in improving SCGC workability and compressive strength due to durability. The sodium hydroxide molarity rises marginally reducing the fresh properties of self-compacting geopolymer concrete. As in the case of self-compacting concrete (SCC) with Portland cement, the durability properties of self-compacting geopolymer concrete are just a fraction of the compressive strength. The durability properties of self-compacting geopolymer concrete are adversely affected by rising test results of physical properties. Out of 5 different SCGC mix series, the optimum mix was achieved when a hundred percent Ground Granulated blast furnace slag (GGBS) and fifty percent river and M-sand were used, which not only showed better compressive strength and durability but also produced adequate workability within the EFNARC Self-Compacting Concrete (SCC) limits.

Feasibility analysis of mustard husk ash for the development of geopolymer mortar

Emerging societal need urged the researchers to develop an alternative to the conventional construction materials. First part of the paper reviewed the papers related to geopolymer based on waste utilization followed by feasibility study on the utilization of mustard husk ash. Mustard husk ash (replacement 50 %) and fly ash with alkali activator (sodium silicate, sodium hydroxide (6 M, 8 M and 10 M)) cured at room temperature as well as at 60 °C for 24 h to develop the geopolymer mortar. The 10 M solution produced the highest compressive strength for the 50% fly ash and 50% mustard ash for 28 days, and this strength rises with the molarity of sodium hydroxide. With an increase in sodium hydroxide molarity, the material sustainability indicator (MSI) revealed a rising trend in terms of embodied energy as well as CO2 emission. As a result, the mustard ash under consideration can be seen as a predecessor to the creation of geopolymers.

Effect of sodium hydroxide concentration on EAFS based alkali activated binder

The emission of greenhouse gases primarily CO2 during the production of cement is a substantial global threat. Along with this the disposal of industrial waste is also a key concern due to leachate. In order to lower the emissions and make better use of industrial waste, a novel technology termed alkali-activated binder (AAB) can be a potential alternative to ordinary portland cement. In the past few years, AAB’s have been a phenomenon of remarkable interest to the construction sector because of their exceptional mechanical qualities and sustainability. The selection of the source material is a critical factor to develop AAB’s. This research attempts to utilize the electric arc furnace slag (EAFS) generated from the production of steel through EAF route as the primary precursor. Four different variations of sodium hydroxide (SH) molarity (8, 10, 12, and 14) were used to investigate its effect on the fresh and mechanical properties of EAFS-based AAB. The alkali to binder ratio of 0.40, curing temperature 80 °C, and 85% humidity were used for preparing the AAB. Scanning electron microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray fluorescence (XRF), and X-Ray diffraction (XRD), are used for material characterization and for analyzing microstructural development.

Optimization of alkali-activated binders using natural minerals and industrial waste materials as precursor materials

This paper presents the results of a study on developing optimized alkali-activated binders (AABs) utilizing selected natural minerals and industrial byproducts as precursor materials in addition to sodium hydroxide and sodium silicate as activators. Four selected precursor materials (natural pozzolana, limestone powder, red mud, and silicomanganese fume) were characterized in terms of their physical and chemical properties. The proportioning of the four precursor materials was optimized based on the results of flow, setting time, and compressive strength tests conducted on trial mortars. After reaching an optimal proportioning of the four precursor materials, the natural pozzolan was partially replaced by ordinary Portland cement (maximum 30% by wt.) to significantly enhance the properties of the AABs. The activator to precursor (A/P) ratio, sodium silicate to sodium hydroxide (NS/NH) ratio, sodium hydroxide (NH) molarity, and water to precursor (W/P) ratio, were varied from 0.3 to 0.6, 1 to 2.5, 8 to14 M, and 0.35 to 0.55, respectively. The influence of these activation parameters (at the optimally selected proportioning of precursor materials) on the physical and mechanical properties of AABs besides their mineral composition and morphology was investigated leading towards selecting the optimum AABs. The compressive strength at 28 days ranged from 28.5 to 32 MPa, 24.15 to 31.8 MPa, 24.2 to 33.1 MPa, 15.33 to 31.16 MPa, and 19.7 to 34.1 MPa, as A/P ratio, NS/NH ratio, NH molarity, W/P ratio, and curing method and duration were varied, respectively. XRD, FTIR, and SEM analyses of the AABs were conducted to validate the trends observed in the compressive strength results with variation in the activation parameters. The main phases detected by XRD included CSH, CASH, Mn-SH, KASH, and NASH. FTIR analysis showed bands that coincide with reported vibration and stretching of Si–O-M (M → Al, Si, or Mn) that are associated with geopolymerization, while SEM imaging showed dense microstructure with a homogenous distribution of polymerization gels that filled the microcracks and voids. Additionally, the effect of curing regimes (oven, steam and ambient-air curing) on the performance of AABs was also examined. The results of the present work enabled to identify the optimum proportioning of the selected precursor materials, optimum combination of A/P ratio, NS/NH ratio, NH molarity, and W/P ratio for producing the AABs with enhanced performance.

Stimulating Antimicrobial Activity in Aspirin with Psidium guajava and Syzygium aromaticum Extracts against Multi-drug Resistant Salmonella Spp: A Comparative Study of Multiple Combinations

Factros such as gene mutation and transfer, some inappropriate uses and diagnostics, and the prescription of antibiotics to undiagnosed patients has significantly led to the emergence of drug resistance in bacteria, which is also hampering our ability to treat infections. As the declines of new antibiotics, scientists and researchers keep trying to develop or propose some synergistic combinations of antibiotics with medicinal plants extracts in an effort to boost their antimicrobial activities against drug resistant bacteria. This work aimed to develop a cocktail regimen, which will be highly susceptible to confirmed drug resistant clinical isolate of Salmonella spp, using Tetracycline, Co-trimoxazole, Aspirin, Psidium guajava and Syzygium aromaticum extract alongside minimizing toxicity potential. Twenty-four (24) different combinations were made from 10 µg/mL of Co-trimoxazole, Tetracycline and Aspirin with each clove extract and separately again with guava extract. Eighteen (18) of them were combined in three different stages (6 each) using concentrated Tetraoxosulphate (vi) acid (H2SO4) and 0.1 Molar sodium hydroxide (NaOH), while 31 antimicrobial disks were prepared and tested on Salmonella spp. The antimicrobial susceptibility test revealed that Scl, a stage 1 combination of Co-trimoxaazole with clove extract; Ac2, a stage 2 combination of Aspirin and clove extract; Ag2, a stage 2 combination of Aspirin and guava leave extract were all susceptible to the confirmed resistant isolate of Salmonella spp. Ag2 had the best zone of inhibition better than Ciprofloxacin inhibition zone at 20 µg/mL. Aspirin was the best precursor drug which favourably combines with both clove and guava extract to give a desired cocktail regimen with potential antimicrobial characteristics. Hence, it is needed to identify the compounds obtained in this combinations, isolates, and purify their active principles, and subjected to other pharmacological test to ascertain if they can be used to combat multi-drug resistant bacteria and other pathogenic organisms.

Effects of Ganoderma lucidum on chemical-induced and bacterial-infected corneal ulceration of rabbits’ eyes

Background: Corneal ulcerations pose risks to blindness, and their treatment presents huge challenges, in part due to increased resistance to anti-bacterial drugs, accessibility and cost issues, particularly in developing countries. This study investigated the pharmacological effect of Ganoderma Lucidum, on chemical-induced and bacterial-infected corneal ulceration of rabbits’ eyes. Methods: This was a randomized-controlled experiment of 16 healthy New Zealand rabbits, randomly assigned into four groups (A–D). The right eye cornea was injured using a drop of 1 Molar sodium hydroxide and followed by infection with Pseudomonas aeruginosa after 12 hours, in all groups except group A. Treatment with freshly prepared crude aqueous extract of G. lucidum (40 μg/mL) for groups A and B, the standard treatment protocol for group C, and atropine alone for group D commenced after 24 hours and continued every four hours for seven days. All data collected, pre-and post-tests, were analysed at α=0.05 using Wilcoxon signed-rank test for correlated variables and the Mann–Whitney U test for independent variables. Results: G. lucidum has significant clinical effects (74%) on corneal injury and ulcers (92%). The healing effects observed at the 168th hour were significantly better than those observed at the 24th hour (p<0.05). Although the difference between the healing effect of the standard treatment and the crude extract was not significant (p>0.05), the mean effect size was clinically significant (31%). Conclusion: This study demonstrates the potential antimicrobial potential of G. lucidum. G. lucidum may provide an alternative treatment option for chemical-induced and bacterial-infected corneal ulcers, particularly in resource-constrained countries.