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1 – 10 of 12Khusrizal, Basyaruddin, R.D.H. Rambe and I. Setiawan
Purpose – The research was carried out in order to study the composition of minerals, content of total-K, total-Ca, total-Mg, and exchangeable of K, Ca, Mg in volcanish ash from…
Abstract
Purpose – The research was carried out in order to study the composition of minerals, content of total-K, total-Ca, total-Mg, and exchangeable of K, Ca, Mg in volcanish ash from Sinabung volcano eruption.
Design/Methodology/Approach – The volcanic ash material in amount of 5 kg was collected from the depth of 0–20 cm and 21–41 cm. Mineral composition was determined by using line counting method; total contents of K, Ca, and Mg were measured by HCl 1N extraction, and exchangeable of K, Ca, and Mg was measured by NH4OAc 1N pH 7.0 extraction.
Purpose – The results depicted in volcanic ash layer at the depth of 0–20 cm found some minerals such as plagioclase (34%), hypersthene (9%), augite (3%), hornblende/amphibole (5%), and volcanic glass (1%). These minerals were also found in different amounts at a depth of 21–41 cm. Hypersthene and amphibole were higher and augite was lower at a depth of 0–20 cm than 21–41 cm. The total content of K, Ca, and Mg was found to be 2.27%, 8.12%, and 2.28%, respectively, at a depth of 0–20 cm. The exchangeable of K, Ca, and Mg was found in an amount of 1.89 me/100 g, 20.71 me/100 g, and 1.62 me/100 g, respectively. The total content of K, Ca, and Mg was not available to plants but could potentially be as a source of plant nutrient after weathering while exchangeable form can be uptaken by plant directly.
Research Limitations/Implications – Based on the composition of the minerals, total, and exchangeable of K, Ca, and Mg that the material of volcanic ash, it could potentially be used as source of fertilizers.
Originality/Value – The composition of primary minerals contained in volcanic ash and to know the amount of elements K, Ca, and Mg-associated minerals either in total or exchange.
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Karima Derdour, Chafia Bouchelta, Amina Khorief Naser-Eddine, Mohamed Salah Medjram and Pierre Magri
The purpose of this paper is to focus on the removal of hexavalent chromium [Cr(VI)] from wastewater by using activated carbon-supported Fe catalysts derived from walnut shell…
Abstract
Purpose
The purpose of this paper is to focus on the removal of hexavalent chromium [Cr(VI)] from wastewater by using activated carbon-supported Fe catalysts derived from walnut shell prepared using a wetness impregnation process. The different conditions of preparation such as impregnation rate and calcination conditions (temperature and time) were optimized to determine their effects on the catalyst’s characteristics.
Design/methodology/approach
The catalyst samples were characterized using thermogravimetric analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption of Cr(VI) by using using activated carbon supported Fe catalysts derived from walnut shell as an adsorbent and catalyst was investigated under different adsorption conditions. The parameters studied were contact time, adsorbent dose, solution pH and initial concentrations.
Findings
Results showed that higher adsorption capacity and rapid kinetics were obtained when the activated walnut shell was impregnated with Fe at 5 per cent and calcined under N2 flow at 400°C for 2 h. The adsorption isotherms data were analyzed with Langmuir and Freundlich models. The better fit is obtained with the Langmuir model with a maximum adsorption capacity of 29.67 mg/g for Cr(VI) on Fe5-AWS at pH 2.0.
Originality/value
A comparison of two kinetic models shows that the adsorption isotherms system is better described by the pseudo-first-order kinetic model.
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Siva Ganapathy Subramanian Manoharan, Rajalakshmi Subramaniam and Sanjay Mohapatra
Chau Thi Ngoc Pham, Hung Ngoc Phan, Thao Thanh Hoang, Tien Thi Thuy Dao and Huong Mai Bui
The health and environmental hazards associated with synthetic dyes have led to a revival of natural dyes that are non-toxic, environmentally benign and coupled with various…
Abstract
Purpose
The health and environmental hazards associated with synthetic dyes have led to a revival of natural dyes that are non-toxic, environmentally benign and coupled with various functions. The study aims to investigate and develop the potentiality of a popular herb called Chromolaena odorata (C. odorata) as a sustainable and stable dyestuff in textiles.
Design/methodology/approach
Natural colorant extracted from C. odorata leaves is used to dye the worsted fabric, which is one of the premier end-use of wool in fashion, via the padding method associated with pre-, simultaneous and post-mordanting with chitosan, tannic acid and copper sulfate pentahydrate. The effects of extraction, dyeing and mordanting processes on fabric’s color strength K/S and color difference ΔECMC are investigated via International Commission on Illumination’s L*a*b* color space, Fourier transform infrared spectroscopy, scanning electron microscope, color fastness to washing, rubbing, perspiration and light.
Findings
The results obtained indicate extraction with ethanol 90% with a solid/liquid ratio of 1:5 within 1 h, and coloration with a liquor ratio of 1:5 (pH 5) within 2 h under padding pressure of 0.3 MPa are the most effective for coloring worsted fabric.
Practical implications
The C. odorata’s application as a highly effective dyestuff possessing good colorimetric effectiveness has expanded this herb's economic potential, contributing partly to economic growth and adding value to wool in global supply chain.
Originality/value
C. odorata dyestuff has prevailed over other natural colorants because of its impressive color fastness against washing, rubbing, perspiration and especially color stability for pH change.
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This paper aims to propose a classroom teaching orchestration technique, analogically drawing a reference from the movie, Prestige (2006). The generation of post-millennials has…
Abstract
Purpose
This paper aims to propose a classroom teaching orchestration technique, analogically drawing a reference from the movie, Prestige (2006). The generation of post-millennials has shorter attention span and motivation and prefers a learner-centric teaching style. This paper attempts to mitigate such challenges by bringing an analogy with a magic trick along with proposing a “divergent-convergent diamond structure” to anchor and synthesise teaching deliverables for the learners.
Design/methodology/approach
This is a practitioner’s study where practical experiences of the authors have led to the conceptualisation of the central theme discussed.
Findings
From a practitioner’s opinion and interpretation, the proposed “divergent-convergent diamond structure” has the potential to make postgraduate classes more engaging. The proposed structure may suggestively promote self-efficacy, trigger curious minds, bring relevance, indulge participatory learning and consolidate the concepts.
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G. R. Chandrashekhar and R. Srinivasan
This research recognizes the importance of the founding conditions of a firm. A new construct, Founding Time (FT) has been conceptualized, measured, and validated to represent one…
Abstract
This research recognizes the importance of the founding conditions of a firm. A new construct, Founding Time (FT) has been conceptualized, measured, and validated to represent one of the founding conditions of a firm. FT is then used to understand the phenomena of growth of firms.
The impact of FT on the growth of a firm has been examined. This examination reveals that there is a certain zone of FT, which seems to result in high firm growth rates. This research also establishes that there is an optimum for the FT of a firm.
A multimethod approach has been used which includes econometric modeling and case studies. This approach has allowed us to triangulate the results of FT in this research.
Folasade Olabimpe Adeboyejo, Olaide Ruth Aderibigbe, Fehintola Oluwatosin Ojo and Steven Akintomide Fagbemi
Several factors may play critical roles in alterations to product quality during storage of hog plum juice. This study aims to evaluate variations to physicochemical, antioxidant…
Abstract
Purpose
Several factors may play critical roles in alterations to product quality during storage of hog plum juice. This study aims to evaluate variations to physicochemical, antioxidant, anti-nutritional properties and microbial stability of hog plum juice during storage.
Design/methodology/approach
Juice was produced from hog plum fruits and stored for eight weeks at refrigerated and ambient conditions. Physicochemical, antioxidant properties, antinutritional factors and microbial properties of juices were determined using standard procedures
Findings
Degradation of ascorbic acid was higher in juices stored at ambient conditions (64.4%) compared to those stored by refrigeration (44.4%). Trends were similar for total phenolic, total flavonoid and total carotenoid contents. Total phenolic, total carotenoid and lycopene contents of fresh juice were 3.9 mg GAE/mL, 4.0 mg/mL and 1.3 mg/mL, which were not significantly different (at p = 0.08, 0.07 and 0.08, respectively) from the values at two weeks of storage at refrigerated conditions (3.9 mg GAE/mL, 3.9 mg/mL and 1.3 mg/mL). A sharp decrease of more than 40% (p = 0.02) in lycopene was recorded after four weeks, irrespective of storage temperature. Pasteurized hog plum juice showed no microbial growth until after four weeks of refrigerated storage when 1 CFU/mL each of bacterial and fungal growth were recorded. The juices, however, showed higher susceptibility to fungal growth as storage period increased.
Research limitations/implications
Other variables not considered in this study such as nature of packaging materials may have significantly contributed to the observed data set. Further studies may, therefore, widen the scope of discussion to evaluate the associated relationship of these variables. Hog plum juice retained a considerable amount of bioactive components during refrigerated storage, which makes it a viable nutraceutical drink with industrial potentials and possible positive health implications for consumers.
Practical implications
This study provides new information that support the possible classification and use of hog plum juice as a safe functional beverage for human consumption.
Originality/value
Although the effect of storage temperature was significant in most of the properties studied, storage duration seems to have a greater influence on the stability of quality parameters during the storage of hog plum juice.
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Ahmed Attalah Hassan Al-Fhdawi and Adel Mashaan Rabee
The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.
Abstract
Purpose
The purpose of this study was to determine the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa.
Design/methodology/approach
Among 303 clinical and environmental samples 109 (61 + 48) isolates were identified as clinical and environmental P. aeruginosa isolates, respectively. Clinical samples were obtained from patients in the Al-Yarmouk hospital in Baghdad city, Iraq. Waste water from Al-Yarmouk hospital was used from site before treatment unit to collect environmental samples. The ability of producing biofilm at various pH levels was examined by microtiter plate and the prevalence of Alg D, Psl A and Pel A was determined by quantitative real time-polymerase chain reaction (qRT-PCR).
Findings
This study showed that the ability of clinical and environmental isolates to biofilm development was observed in 86.9% and 85.42% of clinical and environmental isolates, respectively. As well as, the environmental P. aeruginosa isolates showed the highest biofilm production at pH 7. Clinical isolates showed the highest genes expression of Alg D, Psl A and Pel A as compared to environmental isolates with pH change. In general, both clinical and environmental isolates formed biofilm and carried AlgD, PslA and PelA genes. Also, alkaline pH was favored for biofilm production.
Originality/value
There are very few studies done to find out the influence of environmental pH on production of biofilms and virulence genes expression in Pseudomonas aeruginosa. This study is unique as it has highlighted the influence of environmental pH on the ability of clinical and environmental isolates to biofilm development and genes expression.
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