Dimensional Stability of Lightweight Foamed Concrete Containing Eggshell Powder and Calcium Stearate

In order to reduce eggshell (ES) waste and reduce utilization of pure cement, various researches were conducted to study effects of eggshell powder (ESP) on properties of concrete when it partially replaces ordinary Portland cement (OPC). Dimensional stability is one of the properties that related to cracking issue and soundness of concrete, and it is generally guided by movement of moisture. This study was conducted to study the sorptivity, initial surface absorption, and dimensional stability of lightweight foamed concrete (LFC) that containing eggshell powder and calcium stearate (CS), where, replacement level (RL) of eggshell powder ranged from 0% to 10% at interval of 2.5%, and additional of 1% calcium stearate as cement mass applied for the mixture containing 0% and 5% eggshell powder. The result shows that eggshell powder improves sorptivity, initial surface absorption, and dimensional stability of lightweight foamed concrete and the optimal replacement level is 5%. The result also shows that calcium stearate significantly improves these properties, regardless that incorporation of eggshell powder in the mixture containing calcium stearate might slightly deteriorate these properties. Besides, based on the results, improved sorptivity and initial surface absorption result in increased magnitude of shrinkage as the specimen has lower ability to absorb water for expansion throughout the testing period

A modified ctab-based protocol for total RNA extraction from the medicinal plant Impatiens balsamina (Balsaminaceae) for next-generation sequencing studies

High RNA quality, integrity and reproducibility are essential for functional genomics study involving library preparation and sequencing using next generation sequencing (NGS) technologies. The medicinal herbaceous plant, Impatiens balsamina, possess a rich source of diverse bioactive compounds including polysaccharides and phenolic compounds, hindering the extraction of high quality total RNAs. Four existing RNA extraction protocols were performed using fresh leaf material of I. balsamina, namely the CTAB method, the TRI reagent® method, modified TRI reagent® method and a commercial kit but the results were unsatisfactory. This led to the development of a modified CTAB protocol by combining CTAB/ polyvinylpyrrolidone (PVP) extraction with using commercial spin column purification for successful isolation of high quality total RNA from the leaf material of I. balsamina, that is suitable for NGS applications (RIN values > 7). This new method also successfully extracted total RNA from flower buds and capsules of I. balsamina

Acoustic properties of lightweight foamed concrete with eggshell waste as partial cement replacement material

Nowadays, almost every industry needs to undergo green and sustainable industrial revolution due to pollutions like waste dumping and noise that deteriorating the environment. Therefore, feasibility study on application of eggshell waste as partial cement replacement in lightweight foamed concrete was conducted by aiming to solve environmental and acoustical issues, i.e. reduce eggshell waste and improve acoustic properties. In this study, compressive strength and acoustic properties of 1300 kg m-3 lightweight foamed concrete with and without 5% eggshell powder as partial cement replacement material were tested. Optimal water to cement ratio of 0.6 was obtained for acoustic properties test by comparing compressive strength result. The result shows that application eggshell powder has generally reduced 7 days compressive strength but improved 28 days compressive strength, and either improve or maintain acoustics properties, in which lightweight foamed concrete that containing eggshell powder has improved noise reduction coefficient at testing ages of 7, 28, and 90 days and improved sound transmission class at testing age of 56 and 90 days. Based on these results, 5% of eggshell powder is feasible to be incorporated into lightweight foamed concrete as partial cement replacement material for sound insulation and strength development purposes

Flexural behaviour of reinforced slab panel system with embedded cold-formed steel frames as reinforcement

This paper presents the experimental investigation on flexural characteristic of slab panels with embedded cold-formed steel frame as reinforcement. Perforated cold-formed steel channel sections are formed into steel frames as replacement to the conventional reinforcement bars inside precast concrete slab panels. A series of six experimental specimens for precast slab panels were tested. The specimens with 3 configurations namely control sample (CS) with conventional reinforcement bars, single horizontal C-channel section (SH) and double horizontal C-channel sections (DH) formed into rectangular hollow section. Results show that the tested slab specimens failed at the flexural crack at mid-span, under loading point and shear at the support. Tearing of shear connector in the cold-formed steel section was found to be the main factor for the structural failure. SH specimens achieved the highest ultimate load capacity, with average value of 138.5 kN, followed by DH specimens, 116.5 kN, and the control samples, 59.0 kN. The results showed that the proposed reinforced slab panel with embedded cold-formed steel frame was more effective compared to conventional reinforced sla

Chemical composition of essential oil of exudates of Dryobalanops aromatica

Purpose: To identify the chemical composition of essential oil from the exudates of Dryobalanops aromatica from Malaysia.Methods: Exudate was collected from D. aromatica and subjected to fractional  distillation to obtain essential oil. Gas chromatography-mass spectrometry  (GC-MS) was used to characterize the composition of the isolated essential oil.Results: The yield of essential oil was 7.58 %, with the highest yield (3.24 %) within the first 2 h of fractional distillation. Thirty compounds which accounted for 97.56 % of essential oil composition were identified. These include sesquiterpenes (46.87 %), monoterpenes (31.05 %), oxygenated monoterpenes (16.76 %) and oxygenated  sesquiterpenes (2.13 %). Borneol accounted for 0.74 % of the essential oil.Conclusion: Essential oil from the exudates of D. aromatica contains terpenoid  compounds and borneol.Keywords: Dryobalanops aromatica, exudate, fractional distillation, essential oil, GS-MS, borneo

Determination of borneol and other chemical compounds of essential oil of Dryobalanops aromatica exudate from Malaysia

Purpose: To determine borneol and other chemical compounds of essential oil derived from the exudate of Dryobalanops aromatica in Malaysia.Methods: Exudate was collected from D. aromatica and subjected to fractional distillation to obtain essential oil. Gas chromatography-mass spectrometry (GC-MS) was performed to characterize the composition of the isolated essential oil.Results: Essential oil (7.58 %) was obtained with the highest yield (3.24 %) in the first 2 h of fractional distillation. Thirty compounds which accounted for 97.56 % of total essential oil composition were identified by GC-MS, and they include sesquiterpenes (46.87 %), monoterpenes (31.05 %), oxygenated monoterpenes (16.76 %) and oxygenated sesquiterpenes (2.13 %). Borneol (0.74 %) was also detected in the essential oil.Conclusion: Borneol and other terpenoid compounds are present in the essential oil of the exudate of D. aromatica.Keywords: Exudate, Dryobalanops Aromatica, Fractional distillation, Essential oil, Gaschromatography-mass spectrometry, Borneo

Changes in physicochemical and microbial community during co-composting of oil palm frond with palm oil mill effluent anaerobic sludge

The aims of this study were to investigate the physicochemical changes and microbial population during co-composting of 1 ton oil palm frond (OPF) with 1,000 L palm oil mill effluent (POME) anaerobic sludge. In the first 30 days of composting, the temperature of the composting piles was observed in the thermophilic phase, within a range of 50 - 56 °C. Meanwhile, the oxygen level, moisture content, and pH profiles of the compost were maintained at 2.0 to 12%, 60 to 70%, and 7.9 to 8.5, respectively, throughout the composting process. The total bacteria count was estimated to be about 55 x 1010 CFU/mL in the mesophilic phase, and then it increased up to 66 x 1010 CFU/mL in the thermophilic phase, and finally decreased to 9.0x1010 CFU/mL in the curing phase. The initial C/N ratio, 64, decreased to 18 after 60 days of composting process, indicating the maturity of compost product from OPF-POME anaerobic sludge. The diversity of the bacterial community was investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. The results suggested that the co-composting process of OPF with POME anaerobic sludge was dominated by Pseudomonas sp

Physicochemical changes in windrow co-composting process of oil palm mesocarp fiber and palm oil mill effluent anaerobic sludge

The objective of this study is to investigate the characteristics and physicochemical changes in windrow co-composting process of oil palm mesocarp fiber (OPMF) and palm oil mill effluent(POME) anaerobic sludge at pilot scale. The addition of POME anaerobic sludge as a nutrient source and microbial seeding into the OPMF compost led to the prolonged of thermophillic condition (50– 68°C) until day 39 of treatment. The pH value was remained stable (6.8-7.8) throughout the process whereas the moisture content was reduced towards the end of treatment with final moisture content around 50%. The final matured compost was achieved within 50 days with C/N ratio of 12.6. In addition, considerable amount of nutrients and low level of heavy metals were detected in the final matured compost. The results is indicated that windrow co-composting of OPMF and POME anaerobic sludge could produce acceptable quality of compost that can be used as fertilizer or soil amendment

Effects of Palm Oil Mill Effluent (POME) Anaerobic Sludge From 500m3 of Closed Anaerobic Methane Digested Tank on Pressed-Shredded Empty Fruit Bunch (EFB) Composting Process

In this study, co-composting of pressed-shredded empty fruit bunches (EFB) and palm oil mill effluent (POME) anaerobic sludge from 500 m3 closed anaerobic methane digested tank was carried out. High nitrogen and nutrients content were observed in the POME anaerobic sludge. The sludge was subjected to the pressed-shredded EFB to accelerate the co-composting treatment. In the present study, changes in the physicochemical characteristics of co-composting process were recorded and evaluated. The co-composting treatment was completed in a short time within 40 days with a final C/N ratio of 12.4. The co-composting process exhibited a higher temperature (60 - 67℃) in the thermophilic phase followed by curing phase after four weeks of treatment. Meanwhile, pH of the composting pile (8.1 - 8.6) was almost constant during the process and moisture content was reduced from 64.5% (initial treatment) to 52.0% (final matured compost). The use of pressed-shredded EFB as a main carbon source and bulking agent contributed to the optimum oxygen level in the composting piles (10 - 15%). The biodegradation of composting materials is shown by the reduction of cellulose (34.0%) and hemicellulose (27.0%) content towards the end of treatment. In addition, considerable amount of nutrients and low level of heavy metals were detected in the final matured compost. It can be concluded that the addition of POME anaerobic sludge into the pressed-shredded EFB composting process could produce acceptable and consistent quality of compost product in a short time

Isolation and Characterization of Thermophilic Cellulase-Producing Bacteria from Empty Fruit Bunches-Palm Oil Mill Effluent Compost

Problems statement: Lack of information on locally isolated cellulase-producing bacterium in thermophilic compost using a mixture of Empty Fruit Bunch (EFB) and Palm Oil Mill Effluent (POME) as composting materials.Approach: The isolation of microbes from compost heap was conducted at day 7 of composting process where the mixture of composting materials consisted of 45.8% cellulose, 17.1% hemicellulose and 28.3% lignin content. The temperature, pH and moisture content of the composting pile at day 7 treatment were 58.3, 8.1 and 65.5°C, respectively. The morphological analysis of the isolated microbes was conducted using Scanning Electron Microscope (SEM) and Gram stain method. The congo red test was conducted in order to detect 1% CMC agar degradation activities. Total genomic DNAs were extracted from approximately 1.0 g of mixed compost and amplified by using PCR primers. The PCR product was sequent to identify the nearest relatives of 16S rRNA genes. The localization of bacteria chromosomes was determined by Fluorescence In Situ Hybridization (FISH) analysis.Results: Single isolated bacteria species was successfully isolated from Empty Fruit Bunch (EFB)-Palm Oil Mill Effluent (POME) compost at thermophilic stage. Restriction fragment length polymorphism profiles of the DNAs coding for the 16S rRNAs with the phylogenetic analysis showed that the isolated bacteria from EFB-POME thermophilic compost gave the highest homology (99%) with similarity to Geobacillus pallidus. The strain was spore forming bacteria and able to grow at 60°C with pH 7.Conclusion: Thermophilic bacteria strain, Geobacillus pallidus was successfully isolated from Empty Fruit Bunch (EFB) and Palm Oil Mil Effluent (POME) compost and characterized