91 research outputs found
Teknologi Formulasi Rhizobakteria Berbasis Bahan Lokal dalam Menunjang Bioindustri Pertanian Berkelanjutan
Food as the main of human needs. So, all the sectors that could suppport the advance of plant productivity should be concerned, such as by using the right applied methods. Plant productivity could be increased by fixing their physicology responses to spur plant growth. The using of chemical substances to spur the plant growth have to be switched by using biofertilizer as an alternative through formulation technology of Rhizobacteria based on local materials to support agricultural bioindutry. In the root there are beneficials bacteria which are involved in Plant Growth Promoting Rhizobacteria (PGPR) that could increase the ability of root to absorb soil nutrient and plant hormones synthesis naturally. Endophytics bacteria are founded in the certain of plants root could be isolated and manipulated into biofertilizer product. Generally there are 3 steps in the making process of PGPR : starter making, nutrient making, and fermentation. In this reasearch the endophytics bacteria are isolated from leguminosae root which has a symbiotic with Rhizobium sp., maize (Zea mays sp.) root and bamboo (Bambusa sp.) root which has a symbiotic with Bacillus sp. dan Pseudomonas sp. PGPR utilizes microbacteria as a biological agens that could keep the availability of soil nutrients and increase quality and healthy of soil (soil remediator). In addition of the microbacteria function are : to produce antibiotics, patogen competitor, and to produce plant growth hormone which support plant physicological process
Radiation pattern reconfigurable fm antenna
In this work, a radiation pattern reconfigurable antenna design using compact
printed spiral monopoles that operates at 102 MHz is reported. The proposed antenna changes
its radiation behaviour that responds towards a desired direction with the use of RF switches.
The antenna is printed on a 76.6mm × 50mm PCB layer providing more than 20MHz
bandwidth at -10 dB threshold and is easily fabricated with low manufacturing cost. The
antenna was also simulated on 500mm × 500mm ground plane that represents the roof top of a
vehicl
Porosity and density characteristic of double-layer concrete paving blocks incorporating rubber granules
Porous cement concrete (PCC) is among the most effective voids reducer as compared to other types of concrete paver. The understanding on the techniques to produce durable pavement, the double-layer rubberized concrete paving blocks (DRCPB) was investigate in this study. Two rubber granules (RG) sizes, 1 mm to 4 mm, and 5 mm to 8 mm, were used as partial replacement aggregate to enhance the influence of DRCPB. The DRCPB containing 10 % (DRCPB-10), 20 % (DRCPB-20), 30 % (DRCPB-30), and 40 % (DRCPB-40) of RG designated with 10 mm, 20 mm, 30 mm, and 40 mm thick of top layer, and control concrete paving block (CCPB) were manufactured. Porosity and density test were carried out to analyse the durability characteristics of DRCPB. The results show that the porosity of DRCPB increased multiple when RG content increases from 0 to 40 % where the density of rubberized concrete is directly affected by the RG content
Laboratory investigation of coal bottom ash modified warm mix asphalt
Bottom Ash (BA), a coal combustion by-product, found to be a potential material when used to produce asphalt mixture. However, some of its characteristics make it a questionable material for the surface course. Therefore, this study aims to evaluate the compatibility of BA in Warm Mix Asphalt (WMA) technology through the basic mechanical properties of the asphalt mixtures for binder course layer (AC 28). Two WMA chemical additives, Cecabase RT and Evotherm 3G, were used at the concentrations of 0.3, 0.4 and 0.5% from the binder's weight. The binder properties were assessed through penetration, softening point and viscosity tests. The Marshall mix design was used to determine the optimum binder content (OBC). The additive dosage and production temperature for WMA were determined through Marshall stability, flow, air voids and specific gravity. The results show that the additives did not significantly affect the binder properties, although, at 0.4% Evotherm 3G, a drop of 17.5% in penetration was observed. Cecabase RT produced WMA with promising results but did not enhance the workability of WMA containing bottom ash (BAWMA). By lowering the production temperature of 25 °C, WMA and BAWMA at 0.4 %, Evotherm 3G demonstrated comparable workability to the conventional Hot Mix Asphalt (HMA). The data achieved through this study would be a guiding approach towards the application of BA in WMA technology for sustainable pavements
Sustainable ground improvement method using encapsulated polypropylene (PP) column reinforcement
This study investigates the effectiveness of encapsulated polypropylene (PP) column in enhancing the undrained shear strength of kaolin (soft clay). The usage of PP in treating problematic soil is a more sustainable and cost-effective alternative compared to other materials. The installation of granular column can be done by using vibro-replacement method. Several geotechnical tests to determine the properties of materials were conducted. The shear strength of treated kaolin sample was examined by using Unconfined Compression Test (UCT). There are seven (7) batches of soil sample in total which included a control sample, three (3) batches of 14 mm and three (3) batches of 20 mm diameter PP column. Different diameters of PP column were examined with 60 mm, 80 mm and 100 mm height, respectively with soil sample of 50 mm in diameter and 100 mm in height. The shear strength improvement of kaolin is 33.82%, 46.51%, and 49.88% when implanted with a PP column with a 7.84 area replacement ratio and 0.6, 0.8 and 1.0 penetration ratio. The soft soil treated using 16.00 area replacement ratio with 0.6, 0.8 and 1.0 penetration ratio has a shear strength increment of 25.22%, 33.39% and 37.59% respectively. In short, the shear strength improvement of the kaolin clay depends on the parameter of the PP column used to reinforce the sample
Geotechnical properties of bauxite: A case study in Bukit Goh, Kuantan, Malaysia
The research focuses on the basic and morphological characteristics to ensure bauxite ore reached the International Maritime Solid Bulk Cargoes Code (IMSBC Code) standard before being exported to other countries. The testing procedure, referred to as Geo-spec 3: Model Specification for Soil Testing, was performed to discover the basic parameters of the soil, including pore size distribution, water content, particle density, and morphology qualities. At Bukit Goh, Kuantan, about four (4) samples were chosen, whereas two (2) samples were from the stockpile and two (2) samples were from the Bukit Goh mine. The results illustrated that the mean water content of the soil is 20.64% which is above 10% of the recommended value. The value of Bulk Density is not in the range of 1190 kg/m3 to 1389 kg/m3, which is 2836.25 kg/m3 and the particle size distribution for fine material is greater than 30%, and coarse material is less than 70%. The SEM examination revealed a high concentration of tiny particles in bauxite samples. Bukit Goh bauxite cannot be classified as group C under the IMSBC Code. As a result, the bauxite does not meet the criteria and cannot be shipped
Increment of material usage in construction of four storey reinforced concrete building due to seismic design
Malaysia is fortunate because it is located outside the Pacific Ring-Fire region which is seismically active. However, it still exposes to earthquake hazard from Far-Field earthquake from neighbouring countries. In Peninsular, it is exposes to Sumatra-Andaman earthquake from Indonesia. In East Malaysia, to states namely as Sabah and Sarawak are expose to Philippines earthquake. Besides, Malaysia also experienced earthquakes from local faults such as Bukit Tinggi in 2007. On 5th June 2015, a moderate earthquake with Mw6.1 occurred in Ranau, Sabah which caused 18 fatalities. The same event also caused damage to 61 buildings around Ranau and Kundasang. For the sake of safety, construction of new buildings in Malaysia has to consider seismic design. This paper presents a study to evaluate the increment of construction materials used due to consideration of seismic design. A typical four-storey generic reinforced concrete school building had been used as model. This study adjusted the value of reference peak ground acceleration, αgR in modelling, analysis, and design process. The concrete grade was fixed as C30. Four soil types had been considered for all models with seismic design consideration. Findings from this study demonstrate that the consideration of seismic design caused the increment of steel reinforcement around 16% to 32% for beam and 1% to 14% for column. In term of cost of structural work, consideration of seismic design increases the cost in range of 2% to 5% compared to the nonseismic design. Therefore, it is worth for Malaysia to fully implement the seismic design in new development
Concern with COVID-19 pandemic threat and attitudes towards immigrants: The mediating effect of the desire for tightness
Tightening social norms is thought to be adaptive for dealing with collective threat yet it may have negative consequences for increasing prejudice. The present research investigated the role of desire for cultural tightness, triggered by the COVID-19 pandemic, in increasing negative attitudes towards immigrants. We used participant-level data from 41 countries (N = 55,015) collected as part of the PsyCorona project, a crossnational longitudinal study on responses to COVID-19. Our predictions were tested through multilevel and SEM models, treating participants as nested within countries. Results showed that people’s concern with COVID19 threat was related to greater desire for tightness which, in turn, was linked to more negative attitudes towards immigrants. These findings were followed up with a longitudinal model (N = 2,349) which also showed that people’s heightened concern with COVID-19 in an earlier stage of the pandemic was associated with an increase in their desire for tightness and negative attitudes towards immigrants later in time. Our findings offer insight into the trade-offs that tightening social norms under collective threat has for human groups
Spatial, temporal, and demographic patterns in prevalence of chewing tobacco use in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019
Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Findings In 2019, 273 center dot 9 million (95% uncertainty interval 258 center dot 5 to 290 center dot 9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 center dot 72% (4 center dot 46 to 5 center dot 01). 228 center dot 2 million (213 center dot 6 to 244 center dot 7; 83 center dot 29% [82 center dot 15 to 84 center dot 42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global agestandardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 center dot 21% [-1 center dot 26 to -1 center dot 16]), similar progress was not observed for chewing tobacco (0 center dot 46% [0 center dot 13 to 0 center dot 79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 center dot 94% [-1 center dot 72 to -0 center dot 14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Summary Background Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. Methods We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. Findings In 2019, 273 & middot;9 million (95% uncertainty interval 258 & middot;5 to 290 & middot;9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 & middot;72% (4 & middot;46 to 5 & middot;01). 228 & middot;2 million (213 & middot;6 to 244 & middot;7; 83 & middot;29% [82 & middot;15 to 84 & middot;42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 & middot;21% [-1 & middot;26 to -1 & middot;16]), similar progress was not observed for chewing tobacco (0 & middot;46% [0 & middot;13 to 0 & middot;79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 & middot;94% [-1 & middot;72 to -0 & middot;14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Copyright (c) 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
Using machine learning to identify important predictors of COVID-19 infection prevention behaviors during the early phase of the pandemic
Before vaccines for coronavirus disease 2019 (COVID-19) became available, a set of infection-prevention behaviors constituted the primary means to mitigate the virus spread. Our study aimed to identify important predictors of this set of behaviors. Whereas social and health psychological theories suggest a limited set of predictors, machine-learning analyses can identify correlates from a larger pool of candidate predictors. We used random forests to rank 115 candidate correlates of infection-prevention behavior in 56,072 participants across 28 countries, administered in March to May 2020. The machine-learning model predicted 52% of the variance in infection-prevention behavior in a separate test sample—exceeding the performance of psychological models of health behavior. Results indicated the two most important predictors related to individual-level injunctive norms. Illustrating how data-driven methods can complement theory, some of the most important predictors were not derived from theories of health behavior—and some theoretically derived predictors were relatively unimportant
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