202 research outputs found
Overcome Land Degradation With Soil Ameliorant Application (Study Of Farmer Perceptions In Malang, East Java)
Improving the quality of soils degradation can be achieved
using the soil ameloirant (i. e. Zeolite, manure, compost, etc.), conservation farming systems, organic
management, system balanced fertilization specific location, and efficiency of water use. This study aimed
to determine: (1) the type of soil ameloirant that is still used by farmers, sources of information, and its use
of doses, (2) constraints and benefit of use, (3) fertilizer efficiency, and (4) development opportunities. This
study conducted by survey method that is structured interview included: farmer characteristics, identification,
and soil ameloirant development prospects in the future. Identification of soil ameloirant, such as: type of
soil ameloirant used by farmers, sources of information, applications, the impact of the use, benefits and
constraints of use. The results showed that: the distribution age of respondent ≤ 55 years (80.7%) and > 55
years (19.3%). Dissemination through counseling, pilot project on farmers land in order to developing the
confidence of farmers will benefit and importance of the use soil ameloirant to repair land degradation,
increasing productivity, and agricultural production. The soil ameloirant have been used by 24% of
respondents farmers is zeolite granules (Agro-88) and dolomite; measurement of soil ameloirant for rice
field: 500 kg of zeolit /ha and 577 kg dolomite/ha; garden: 219 kg zeolite/ha and 409 kg dolomite/ ha; mixedgarden:
600 kg of zeolit/ha and 143 kg dolomite/ha. Soil ameloirant benefits is for increasing the production:
paddys, corns, and vegetables (cauliflower, peppers, tomatoes) around 10-30%, improving the soil fertility
and reducing dosage of urea fertilizer as much as 15-30% and SP-36 as much as 30%
Strengthening the Region of Intermediate Support of Continuous Reinforced High-Strength Concrete Slabs with New Cement
Concrete is being widely used as a construction material, hence it is necessary to improve its properties. These days supplementary cementecious materials are used for enhancement of concrete properties. Use of Nano materials is gaining importance due to its vital characteristics, these materials help in developing high performance concrete (Zhang Zenan, et al 2006).In this paper, the use of steel fibers instead of the reinforcement steel bars in the continuous nano-high strength concrete (NHSC) slab panel was experimentally investigated. Tests were carried out on three two-span slab panels under mid span point loads and simply supported at the panels end. The first slab was reinforced by steel bars to resist the negative moments near the internal supports while the other two slab panels were reinforced by steel fibers only of percentage of volume fraction (1 and 2.0) in this zone, without negative steel bars. 5% nano-SiO2 (NS) and 15% of silica fume (SF) contents were used. The load-deflection relationship for the tested slab spans is determined, the first crack load, failure load and deflections were recorded. Also a comparison between the results obtained from this study and that obtained from other study of two continuous slabs made of self compacted concrete (SCC) was made , one of these slabs was reinforced by steel bars near the interior supports and the other is reinforced by steel fibers of (1% and 2%) in this zone. Experimental results show that the ultimate load capacity are increased (15.4% - 32.9%) and the cracking loads are increased (40%-56%) for tested specimens strengthened with SFRC, in comparison with the reference specimens. The comparison between the NHSC slabs and corresponding SCC slabs shows a similar load-deflection curve but the ultimate strength capacity for the NHSC slabs with steel fiber gives ultimate strength larger than SCC slabs with steel fibers, while the NHSC slabs reinforced by steel bars which show an important effect on the first cracking loading in comparison with SCC slabs. loading in comparison with CC slabs. Keywords: key words, Nano, negative moment, Self-Compacting Concret
Marine health of the Arabian Gulf: Drivers of pollution and assessment approaches focusing on desalination activities
The Arabian Gulf is one of the most adversely affected marine environments worldwide, which results from combined pollution drivers including climate change, oil and gas activities, and coastal anthropogenic disturbances. Desalination activities are one of the major marine pollution drivers regionally and internationally. Arabian Gulf countries represent a hotspot of desalination activities as they are responsible for nearly 50% of the global desalination capacity. Building desalination plants, up-taking seawater, and discharging untreated brine back into the sea adversely affects the biodiversity of the marine ecosystems. The present review attempted to reveal the potential negative effects of desalination plants on the Gulf's marine environments. We emphasised different conventional and innovative assessment tools used to assess the health of marine environments and evaluate the damage exerted by desalination activity in the Gulf. Finally, we suggested effective management approaches to tackle the issue including the significance of national regulations and regional cooperation
Troubleshooting During Temporary Epicardial Lead Implantation in a Child with an Erosive Twiddler’s Syndrome and Multiple Sternotomies: A case report
Temporary epicardial cardiac pacing in patients with bradyarrhythmias may be used as a bridge to implantation of a permanent pacemaker. The temporary epicardial lead placement may sometimes necessitate a sternotomy that may pose a challenge in patients who have had multiple earlier sternotomies. The difficulty in accessing the epicardium for urgent implantation of temporary epicardial pacing leads depends on the extent of adhesions in such patients. We report an 8-year-8-month-old girl with a pacemaker with an extruded pulse generator and difficult myocardial access due to 5 prior transsternal procedures. The child presented to a tertiary care hospital in Muscat, Oman, in 2021. A trouble-shooting technique was adopted to achieve temporary epicardial pacing to provide time for a course of antibiotic therapy administration. A permanent transvenous pulse generator system was implanted after 7 days of temporary pacing.
Keywords: Heart Block; Artificial Pacemaker; Implanted Electrodes; Case Report; Oman
Comparison of biocrude oil production from self-settling and non-settling microalgae biomass produced in the Qatari desert environment
The present study investigated the growth, harvesting, biocrude conversion, and recycling of the HTL aqueous phase for one self-settling (i.e., Chlorocystis sp.) and another non-settling (i.e., Picochlorum sp.) marine microalgae. Both the strains were grown simultaneously in 2 identical 25,000-L raceway ponds in the Qatari desert. The cell size of Picochlorum sp. was small (2–3 µm), and its biomass was harvested using a centrifuge. Cells of Chlorocystis sp. (6–9 µm) formed flocs that settled spontaneously in a sedimentation chamber. Harvested biomass of these two strains was then converted to biocrude oil, using a 500-mL Parr reactor. The biocrude yield of Picochlorum sp. and Chlorocystis sp. was 39.6 ± 1.15% and 34.8 ± 1.65%, respectively. The energy content of the biocrude oil was 32.78 and 33.38 MJ/kg for Chlorocystis sp. and Picochlorum sp., respectively. Both the strains were capable of efficiently utilizing more than 95% nitrogen of the HTL aqueous phase. Although lower biocrude yield was obtained from Chlorocystis sp., compared to Picochlorum sp., harvesting of Chlorocystis sp. would require much lower energy compared to Picochlorum sp. Therefore, a self-settling microalgae (e.g., Chlorocystis sp.) could potentially be a better candidate, over non-settling microalgae, for producing biofuel feedstock.Open Access funding provided by the Qatar National Library. The authors would like to acknowledge the support of Qatar National Research Fund (QNRF, a member of Qatar Foundation) for providing the funding (under Grant NPRP8-646-2-272) for this study. The authors appreciate the assistance of Ms. Noora (from ESE labs) and Dr. Ahmed (from CLU) for GC?MS and CHN analyses, respectively.Scopu
Comparative Assessment of Toxic Metals Bioaccumulation and the Mechanisms of Chromium (Cr) Tolerance and Uptake in Calotropis procera
Progressive pollution due to toxic metals significantly undermines global environmental sustainability efforts. Chromium (Cr) is one of the most dangerous to human health. The use of plants to rid the environment of such pollutants "phytoremediation" proves to be a promising alternative to the current remediation methods. In the present study, inductively coupled plasma optical emission spectroscopy (ICP-OES) determined Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), and Lead (Pb) concentrations in the soil, and plants (Atriplex leucoclada, Calotropis procera, Salsola imbricata, Typha augustifolia, and Phragmites australis) root and shoots. Results showed that compared to other studied metals, Cr concentration was the highest in the soil at 111.8 mg/kg, whereas Cd records the least concentration of 0.04 mg/kg. Cr also accumulated in higher concentration in C. procera than in the soil and other plants, with up to 188.2 and 68.2 mg/kg concentration in the root and shoot, respectively. In order to understand the mechanism of Cr tolerance and uptake in C. procera, germinated seeds were irrigated with 20 mg/kg Cr and control treatment (no Cr applied) for six (6) weeks under greenhouse conditions. Fourier transformed infrared spectroscopy (FTIR) results showed high Cr complexation and binding to C. procera tissues via hydroxyl and carboxylic groups. Enzymatic assay reveals increased activities of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) in Cr treated C. procera than in the control. SOD activity increased by up to six (6) folds. Therefore, we conclude that C. procera is suitable for the phytoremediation of Cr polluted arid soil. Additionally, regulation of cellular homeostasis via redox signaling is essential to the Cr tolerance and detoxification mechanism. Copyright 2020 Usman, Al Jabri, Abu-Dieyeh and Alsafran.This work was supported by the Qatar University vegetable factory project QUEX-CAS-MJF-VF-18-19.Scopu
Potential utilization of waste nitrogen fertilizer from a fertilizer industry using marine microalgae
This study investigated the feasibility of microalgal biomass production using waste nitrogen fertilizers (WNFs) generated by the Qatar Fertiliser Company (QAFCO). From the plant, three types of WNFs (WNF1, WNF2, and WNF3) were collected; WNF1 and WNF2 had high solubility (e.g., 1000 g/L) whereas WNF3 had low solubility (65 g/L). For a lower dosage (i.e., 100 mg N/L) of these WNFs, >98% of nitrogen was soluble in water for WNF1 and WNF2; however, 52 mg N/L was soluble for WNF3. Nitrogen content in these wastes was 44, 43, and 39% for WNF1, WNF2, and WNF3, respectively. As these WNFs were used as the sole nitrogen source to grow Tetraselmis sp., Picochlorum sp., and Synechococcus sp., Tetraselmis sp. could utilize all the three WNFs more efficiently than other two strains. The biomass yield of Tetraselmis sp. in a 100,000 L raceway pond was 0.58 g/L and 0.67 g/L for mixed WNFs (all WNF in equal ratio) and urea, respectively. The metabolite profiles of Tetraselmis sp. biomass grown using mixed WNFs were very similar to the biomass obtained from urea-added culture - suggesting that WNFs produced Tetraselmis sp. biomass could be used as animal feed ingredients. Life cycle impact assessment (LCIA) was conducted for six potential scenarios, using the data from the outdoor cultivation. The production of Tetraselmis sp. biomass in QAFCO premises using its WNFs, flue gas, and waste heat could not only eliminate the consequences of landfilling WNFs but also would improve the energy, cost, and environmental burdens of microalgal biomass production. 2020The authors would like to acknowledge the support of the Qatar National Research Fund (QNRF, a member of Qatar Foundation) for providing the funding (under grant NPRP8-646-2-272) for this study.Scopu
Investigating algal CO2 capture through screening of Qatari desert microalgae & cyanobacteria strains
CO2 fixation by phototrophic microalgae has been addressed as a possible global carbon emissions reducer, whilst simultaneously producing useful products. Especially in Qatar, the prospect of using microalgae for CO2 abatement is promising: high solar irradiance, large areas of non-arable land, and large amounts of CO2 emissions make it seemingly the ideal place for algae cultivation. In order to promote high biomass productivities, and subsequent CO2 uptake rates, effective CO2 supply to the cultivation system is of high importance. However, the low solubility of CO2 in water, as well as the limiting tolerance of microalgae to increased CO2 concentrations, results in low efficiency of CO2 capture by microalgal production systems. In order to overcome these hurdles, this research focused on selecting local desert microalgae strains with high tolerance to increased CO2 levels, and developing growth media in order to increase the solubility of CO2. Forty-five locally isolated marine microalgae strains were screened for growth under increased CO2 concentrations, ranging from 0.04% to 30% (v/v). A number of different trends in CO2 tolerance could be identified from the results; a number of strains showed a clear inhibition of growth with CO2 concentrations of 5% and higher, whilst others showed increasing growth rates for increasing CO2 concentrations up to 30%. The trend in growth rate suggests that even higher CO2 concentration could be applied without growth-limiting effects, and could even stimulate higher growth-rates. In order to further increase the productivity of high CO2-tolerant strains, as well as to investigate the effects of pH on the CO2 tolerance of low-tolerant strains, various strains were cultivated in alkaline media and high CO2 concentrations. Besides leading to an increased solubility of CO2 in the culture media, increasing the pH is thought to balance the acidification effect of CO2 - possibly leading to higher CO2 tolerances. Overall, applying these strains and media adaptations for large-scale applications is expected to increase the CO2 transfer efficiency to the culture, resulting in decreased operational costs and higher overall productivities.qscienc
Techno-economics of algae production in the Arabian Peninsula
The Arabian Peninsula's advantageous climate, availability of non-arable land, access to seawater and CO2-rich flue gas, make it an attractive location for microalgae biomass production. Despite these promising aspects, the region has seen very few studies into the commercial feasibility of algae-based value chains. This work aims to address this gap through a techno-economic feasibility study of algae biomass production costs, comparing different photobioreactor types, locations, and production scales. Flat panel and raceway pond cultivation systems were found to be the most economically attractive cultivation systems, with biomass production costs as low as 2.9 €·kg−1. Potential cost reductions of up to 42.5% and 25% could be accomplished with improvements in photosynthetic efficiencies and increased culture temperatures, respectively. As of such, efforts to source local thermo- and photo- tolerant strains could be the key to unlock the potential of the region for algae commercialization, linking into food, feed and nutraceutical industries.The authors would like to thank Tommaso de Santis, Probir Das, Mahmoud Taher, and the QDVC team for their support. This work was sponsored by QDVC and Qatar University [Project: QUEX-CAS-QDVC-14/15-7]. Open Access funding was provided by the Qatar National Library
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