Search

Rainfall erosivity and rainfall kinetic energy are predominantly affected by the rainfall droplet size distribution characteristics. This study aims to determine the raindrop size distribution with different rainfall intensities in East Malaysia using photographic method and MATLAB image processing tools. A total of five natural rainfall intensities of different ranges were analyzed: 5.51 mm hr-1, 14.20 mm hr-1, 28.80 mm hr-1, 32.41 mm hr-1 and 58.11 mm hr-1. A digital camera with fast capturing mode was used to capture falling raindrops and the droplets were then processed in MATLAB to determine the raindrop size distribution. It was found that the captured raindrop diameters were within the range of 0.1 mm and 5.0 mm, and a higher portion of the raindrops fell between 0.1 mm and 1.0 mm. The results also showed that higher rainfall intensities would promote the formation of larger raindrop sizes, i.e., from 1.0 mm to 5.0 mm, and lower rainfall intensities tended result in higher drop counts in smaller raindrop sizes of

In Sarawak, a state of Malaysia on Borneo Island, clean water supply coverage is estimated to be 81.4% in 2020, whereby those without access to clean water are rural residents. Although the state aims to achieve full clean water supply coverage by 2025, budget limitations make this impossible. This research proposes a decentralized water supply system that harvests rainwater and river water to supply rural households with clean water. The selected study area is Pelaman Monggak, a rural village in Bau District, Sarawak. The rainwater storage tank was modelled using the Tangki NAHRIM (NAHRIM Tank). The results showed that for a rural household of five people, the reliability for a tank size of 2 m3 is 84.5%. From 2010 to 2019, the rainwater storage tank can supply rainwater for 3044 days, with the remaining 608 days supplied by river water. As river water is not safe for potable use, treatment is needed. The proposed water treatment process for river water includes bamboo activated carbon adsorption, membrane microfiltration, and UV disinfection to improve the river water quality from Class II to Class I. For rainwater, two treatment processes, namely membrane microfiltration and UV disinfection, are sufficient to produce safe drinking water quality.

Significant effects of organoclay and poly(melamine-co-formaldehyde)-methylated (PMFM) impregnation on the mechanical, morphological, and thermal characteristics of raw pulai wood were investigated in this work. The material’s modulus of elasticity (MOE) as well as the maximum compression force (MCF) of the impregnated organoclay/PMFM pulai wood samples were optimized using a designed experiment. The MOE and MCF models had R2 values of 0.9228 and 0.8340, respectively. After the impregnation of organoclay/PMFM pulai wood samples, the MOE and MCF increased considerably, indicating that the pulai wood’s mechanical characteristics had improved. The compositional analysis verified the polymerization and dispersion of organoclay and PMFM. Using Fourier transform infrared spectroscopy, reduction in the hydroxyl groups was detected. The impregnated organoclay/PMFM pulai wood samples had successfully filled the pores and cell cavities, as seen by scanning electron microscopy. The thermal stability of the impregnated organoclay/PMFM pulai wood samples was better than that of the raw pulai wood, with a higher glass transition temperature as determined by differential scanning calorimetry. The thermogravimetric study revealed that the impregnated organoclay/PMFM pulai wood samples had higher decomposition temperatures than the raw pulai wood sample.

High dietary phosphate intake and poor adherence to phosphate-binding-therapy elevate the risk of hyperphosphatemia in maintenance hemodialysis (HD; MHD) patients. Therefore, chronic kidney disease-related mineral and bone disorder (CKD-MBD) indicators increase; consequently, risks of CKD-MBDs and inflammation are elevated. This double-blind, randomized control trial intervention study was designed to investigate the possibility of reducing blood CKD-MBD indicators and modulating inflammatory indicators by consuming low-phosphate (LP) meals accompanied by a minimum dose of a calcium-based phosphate binder (CaCO3). MHD patients were recruited and randomly assigned to an LP meal group (LP group) or a control group. After initial data collection, blood collection, and dietary counseling, subjects were asked to consume a washout diet for 1 week. During the washout diet period, subjects consumed their usual diet but took 1 tablet of calcium carbonate (1CaCO3) as a phosphate binder with each meal. After the washout diet period, subjects in the LP group and control group respectively consumed LP meals and regular meals twice a day for 1 week. Meat in the LP meals was boiled before the regular cooking process, but meat in control meals was not. All meals were supplied by a central kitchen so that the contents of phosphate and other nutrients could be identified. In total, 40 MHD patients completed the study program. After 1 week of the dietary intervention, the blood Ca x P product and dietary phosphate had significantly decreased in the LP group compared to the control group (p

The effect of chemical treatment on silicon manganese slag and the effect of curing time on the compressive strength of completely replacement coarse aggregate silicon manganese concrete (SMC) relative to normal weight concrete (NWC) with gravel as coarse aggregate is the subject of this paper. Alkali and acidic base chemicals are used to alter the neat silicon manganese slag during chemical preparation. The mixture pattern proportions for Grade 30 and Grade 50, respectively, were used to create the concrete. Before the compressive strength tests, the samples were cast and cured for 7-, 14-, and 28-days. The properties of the silicon manganese slag and its concrete were studied using a scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The compressive pressure of SMC30 and SMC50 obtained were 37.3 MPa and 51.1 MPa, respectively, on the 28-day. The alkaline treatment smoothest the matrix, while the acid treatment roughens the composition of the silicon manganese slag, according to SEM. The functional group demonstrated a major improvement in FTIR, while EDS revealed a high content of both silicon (Si) and manganese (Mn) elements. As a result, it can be observed that the power of SMC increases as the curing time increases for samples with complete replacement of normal aggregates using silicon slag

The compressive strength of high-volume fly ash (HVFA) concrete with varied volume percentages of 40%, 50%, and 60% was examined utilizing low calcium fly ash (Class-F) as a partial replacement for regular Portland cement in this study. On the 7th, 28th, and 56th days, the compressive strength is tested. At the 7th and 28th days, the influence of saturated lime water on the compressive strength of HVFA concrete is evaluated. The inclusion of fly ash as a replacement for Portland cement reduces the compressive strength of the HVFA concrete, according to the findings. At the 56th day, the HVFA concrete with 40% fly ash substitution has a compressive strength equivalent to the regular weight concrete. At the 28th day, it was discovered that saturated lime water was helpful in maximizing the strength of HVFA concrete with 50% fly ash substitution. There was additional information about the characterization of HVFA concrete.

Additional file 1: Table S1. Characteristics of CKD patients stratified by electrolyte and mineral disorders.