Elucidating the plasticizing effect on mechanical and thermal properties of poly(lactic acid)/carbon nanotubes nanocomposites

Poly(lactic acid) (PLA) is a biodegradable plastic and grabs attention in several applications such as biomedical implantation, film, packaging and clothing. Instead, PLA itself has a characteristic of brittleness, resulting in poor mechanical properties, and its slow ability in degradation leads to waste disposal problem. The present research aims to develop material in such a way to have a good combination of properties and optimum degradation ability. The PLA nanocomposites were prepared via melt blending that consisted of two types of carbon nanotubes (CNTs): unmodified carbon nanotubes (CNTs) and modified CNTs (mCNTs). The effect of 5 wt% poly (ethylene glycol) (PEG) as plasticizer on nanocomposites with CNTs material loading at 0.5 wt%, 1.0 wt%, 1.5 wt% and 2.0 wt% was studied. The analysis of physical properties was done using hardness testing and melt flow index (MFI). Neat PLA only gave around 69.0–77.6 Shore D in hardness test, while MFI exhibited around 36.1–39.4 g/10 min. PLA/mCNTs and PLA/PEG/mCNTs at 1.5 wt% exhibited the highest values of hardness testing which were 86.0 and 85.9 Shore D, respectively. In MFI study, the results were 70.0 g/10 min for PLA/mCNTs and 80.3 g/10 min for PLA/PEG/mCNTs. This proved that the PEG is useful in reducing the brittleness of nanocomposite. The full exfoliation of CNTs and mCNTs in the matrix observed from the X-ray diffraction analysis supported the excellent hardness and MFI properties. These nanocomposites also showed high thermal stability as obtained from differential scanning calorimetry and thermogravimetric analysis studies compared with neat PLA. The morphology study by field emission scanning electron microscopy analysis confirmed these findings through the existence of a smooth fracture surface, especially when PEG was loaded as evidence of good distribution of nanofiller in the matrix was established. Based on all analyses done, PLA/PEG/mCNTs were chosen as the good nanocomposite among others

CaCO3 from seashells as a reinforcing filler for natural rubber

Bio-composites, due to their sustainably renewable nature, have attracted considerable attention due to their low cost and bio-degradability. CaCO3 from seashells is a ‘green’ calcium carbonate that could enhance the mechanical and thermal properties of composites. The mixing of natural rubber (NR) with CaCO3 using melt blending enhanced the hardness and tensile strength of the composites. The glass transition temperature did not have a significant effect on the composites, while the composites with filler of 355 µm in size showed the highest melting point in differential scanning calorimetry (DSC) analysis

Environmental Performance of the Stormpav Permeable Pavement Using the Stormwater Management Model (SWMM)

Urban stormwater runoff is contaminated with a variety of pollutants, including total suspended solids (TSS) and total phosphorus (TP), as a result of non-source pollution from transportation, residences, and businesses, as well as sediment from human activities and construction sites. These pollutants are expected to degrade the water quality in local rivers and streams, impairing the quality of marine life and contaminating drinking water supplies. This study evaluates the environmental performance of a permeable pavement system in an urban catchment using the stormwater management model (SWMM). Two pavement systems with different hydraulic designs were compared to reduce runoff, increment of groundwater storage and the environmental parameters assessments on total suspended solids (TSS) and Total Phosphorus (TP). The first system comprises a StormPav, which is the UNIMAS innovated green pavement with subsurface hollow cylindrical micro-detention pond storage of about 70% void content. The second system consists of porous concrete (PC) pavement assembled in a layered of coarse and fine particles to ensure water can infiltrate through, with about 40% void content. The environmental impact assessment was applied at Padungan Commercial Centre in the Kuching City of Malaysia. The case study simulated  low impact development (LID) sub-catchment in SWMM to obtain the runoff, infiltration and environmental quality performance. In the assessment, it was found that, for both pavement systems, higher storms at shorter duration resulted in higher reduction efficiency. The StormPav is more effective in reducing runoff while presenting a lower value for environmental assessments in removing TSS and TP compared to PC

Environmental Performance of the Stormpav Permeable Pavement Using the Stormwater Management Model (SWMM)

Urban stormwater runoff is contaminated with a variety of pollutants, including total suspended solids (TSS) and total phosphorus (TP), as a result of non-source pollution from transportation, residences, and businesses, as well as sediment from human activities and construction sites. These pollutants are expected to degrade the water quality in local rivers and streams, impairing the quality of marine life and contaminating drinking water supplies. This study evaluates the environmental performance of a permeable pavement system in an urban catchment using the stormwater management model (SWMM). Two pavement systems with different hydraulic designs were compared to reduce runoff, increment of groundwater storage and the environmental parameters assessments on total suspended solids (TSS) and Total Phosphorus (TP). The first system comprises a StormPav, which is the UNIMAS innovated green pavement with subsurface hollow cylindrical micro-detention pond storage of about 70% void content. The second system consists of porous concrete (PC) pavement assembled in a layered of coarse and fine particles to ensure water can infiltrate through, with about 40% void content. The environmental impact assessment was applied at Padungan Commercial Centre in the Kuching City of Malaysia. The case study simulated  low impact development (LID) sub-catchment in SWMM to obtain the runoff, infiltration and environmental quality performance. In the assessment, it was found that, for both pavement systems, higher storms at shorter duration resulted in higher reduction efficiency. The StormPav is more effective in reducing runoff while presenting a lower value for environmental assessments in removing TSS and TP compared to PC

Assessing the significance of rate and time pulse spraying in top spray granulation of urea fertilizer using Taguchi Method

Studies in urea granulation process using Top Spray Fluidized Bed Granulator (TSFBG) is still limited and requires in-depth research about the effectiveness and influence of droplets to the formation of urea granule (UG). Rate and time interval of spraying technique (Pulse) significantly influence the physical properties of urea granules. Cassava starch dissolves in water was selected as the binder released at various time interval to observe impact of spray droplet on UG size formation. Using Taguchi Method, the study had identified three leading factors contributed to the formation of droplet size namely volume of binder (VOB), time pulse of spraying (TPS) and spraying rate (SR). These factors were then evaluated in terms of the influence on response as signal-to-noise analysis (S/N ratios) from Taguchi to validate UG size in range 2 mm to 4 mm from screening process with respect to the actual experimental data. These results were useful for future experiment reference to determine pressure drop and surface contact during interaction between droplet and urea powder partic

Disease Detection of Solanaceous Crops Using Deep Learning for Robot Vision

Traditionally, the farmers manage the crops from the early growth stage until the mature harvest stage by manually identifying and monitoring plant diseases, nutrient deficiencies, controlled irrigation, and controlled fertilizers and pesticides. Even the farmers have difficulty detecting crop diseases using their naked eyes due to several similar crop diseases. Identifying the correct diseases is crucial since it can improve the quality and quantity of crop production. With the advent of Artificial Intelligence (AI) technology, all crop-managing tasks can be automated using a robot that mimics a farmer's ability. However, designing a robot with human capability, especially in detecting the crop's diseases in real-time, is another challenge to consider. Other research works are focusing on improving the mean average precision and the best result reported so far is 93% of mean Average Precision (mAP) by YOLOv5. This paper focuses on object detection of the Convolutional Neural Network (CNN) architecture-based to detect the disease of solanaceous crops for robot vision. This study's contribution involved reporting the developmental specifics and a suggested solution for issues that appear along with the conducted study. In addition, the output of this study is expected to become the algorithm of the robot's vision. This study uses images of four crops (tomato, potato, eggplant, and pepper), including 23 classes of healthy and diseased crops infected on the leaf and fruits. The dataset utilized combines the public dataset (PlantVillage) and self-collected samples. The total dataset of all 23 classes is 16580 images divided into three parts: training set, validation set, and testing set. The dataset used for training is 88% of the total dataset (15000 images), 8% of the dataset performed a validation process (1400 images), and the rest of the 4% dataset is for the test process (699 images). The performances of YOLOv5 were more robust in terms of 94.2% mAP, and the speed was slightly faster than Scaled-YOLOv4. This object detection-based approach has proven to be a promising solution in efficiently detecting crop disease in real-time

Fabrication Rutile-Phased TiO2 Film with Different Concentration of Hydrochloric Acid Towards the Performance of Dye-Sensitized Solar Cell

In this study, one-step hydrothermal method is demonstrated to synthesis TiO2 double-layer structure by modifying the concentration of hydrochloric acid (HCl). The X-ray diffraction (XRD) pattern analysis suggested that the dominant peak is rutile phase. Interesting morphologies such as cauliflower, chrysanthemum flower or dandelion structures over the nanorods layer were revealed by FE-SEM images and showed substantial effects to the thin film performance. UV-vis absorption spectra of prepared TiO2 film is in UV limitation with band gap energy (Eg) range from 2.57eV to 3.0eV. The optimum photoelectric conversion efficiency of DSSC is 42.5% that exhibited the efficiency of 6.41% for the sample synthesized using equal proportion of de-ionized water and HCl amount or in another word in accordance of ratio 1:1. These results serve as a guidance principle for preparing high quality DSSC thin film

Degradability studies of PLA nanocomposites under controlled water sorption and soil burial conditions

Polymer blended nanocomposites based on polylactic acid (PLA) were prepared via a simple melting process and investigated for its biodegradation behaviour. The treated CNTs were surface modified by using acid treatment and characterisations of composites were done by using Fourier Transform Infra-Red (FTIR) and UV-Vis. FTIR spectra and UV-Vis peak confirmed the surface modification of CNTs. The water uptake and weight loss behaviour based on CNTs and m-CNTs loading at different temperatures (25° and 45°C) were studied. It was found that the water absorption and weight loss of nanocomposites increased by the incorporation of CNTs and m-CNTs. Moisture induced degradation of composite samples was significant at elevated temperature. The addition of treated CNTs successfully reduced the water uptake and weight loss of nanocomposites due to less hydrolytic effect of water on nanocomposites. In soil burial test, the weight loss increases with addition of nanofiller. The loading of m-CNT reduced the ability of nanocomposites degradation

Nicotine Impaired Bone Histomorphometric Parameters And Bone Remodeling Biomarkers In Sprague-Dawley Male Rats

The effects of nicotine administration on structural and cellular parameters of bone histomorphometry, cotinine, and biomarkers of bone remodeling were studied in twenty-one Sprague-Dawley male rats. Rats aged three months and weighing between 250-300 g were divided into three groups. Group 1 was the baseline group, which was sacrificed without treatment. The other 2 groups were the control group and the nicotine group. The nicotine group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection, six days a week for a period of 4 months. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis was done using ELISA-test kit to compare the serum cotinine, osteocalcin and pyridinoline (PYD) levels between pretreatment and after 4 months treatment in the control and nicotine groups. Histomorphometric analysis revealed that nicotine significantly decreased the trabecular bone volume (BV/TV) and the osteoblast surface (Ob.S/BS), and increased the osteoclast surface (Oc.S/BS) and the eroded surface (ES/BS) compared to the baseline and control groups. In addition, biochemical analysis showed that nicotine treatment for 4 months significantly decreased the osteocalcin (bone formation marker) levels while the cotinine and PYD (bone resorption marker) levels were increased as compared to pretreatment. We concluded that treatment with nicotine 7 mg/kg for 4 months exerted negative a effect on the trabecular bone histomorphometric parameters and bone remodeling biomarkers

Effects of fractionation technique on triacylglycerols, melting and crystallisation and the polymorphic behavior of bambangan kernel fat as cocoa butter improver

Cocoa butter improver (CBI) is typically composed of high melting symmetrical triacylglycerols (TAGs) that aid in the hardness of chocolate products in tropical/subtropical regions. High-melting symmetrical TAG (1,3-di-stearoyl-2-oleoyl-glycerol, SOS) rich fats were produced by two-stage acetone fractionation. Different chromatographic and thermal techniques were used to determine TAGs, thermal properties, and polymorphic behavior of each bambangan kernel fat (BKF) fraction. The first (S-1) and second (S-2) stearins composed of 55.83% and 64.70% symmetrical SOS were the valuable CBIs produced from the fractionated BKF. The stearin fractions also melted and crystallised rapidly at high temperatures with one maximum peak starting at 20.30–21.74 °C and ending at 38.72–42.45 °C (melting), and another starting at 17.05–18.46 °C and ended at 5.63–8.20 °C (crystallisation). In comparison with pure BKF and commercial cocoa butter (CB), the stearins showed sharper melting curves and higher melting properties. The stearins also exhibited β-polymorphic form which was similar to that of CB. Results suggested that the stearins were suitable to be applied as CBI to improve the melting properties and the availability of confectionery products in tropical/subtropical countries