scholarly journals Acidic Wet Deposition in Bandung City Indonesia

2018 ◽  
Vol 147 ◽  
pp. 08007
Author(s):  
Nia Yuniarti Hasan ◽  
Driejana ◽  
Aminudin Sulaeman ◽  
Herto Dwi Ariesyady
Keyword(s):  
Temporal Variation ◽  
Electric Conductivity ◽  
Wet Deposition ◽  
Acidic Deposition ◽  
Negative Impact ◽  
Chemical Properties ◽  
Precipitation Chemistry ◽  
Value Range ◽  
The Mean ◽  
Environment Measurement

Acidic deposition (acid rain) has been known to cause negative impact to environment. Measurement of rain chemical composition was done in March to August 2016 to investigate temporal variation of atmospheric deposition in Bandung City. Rainwater samples are collected at four sampling sites. The chemical properties of the rain determined were pH and ionic concentrations of SO42-, NO3-, Cl-, Ca2+, Mg2+, Na+, K+ and NH4+. The rainwater was typically acidic with the range of mean pH between 5.29 – 5.56 and mean electric conductivity value range between 16.37 – 19.96 μS/cm. Temporal variation showed higher SO42+, NO3+ and NH4+ concentration in August when rainfalls were the lowest (214.88 mm). Similar temporal variation for the mean pH (5.98) and electric conductivity (25.36 μS/cm) in August. Ca2+ highest concentration was observed in June. Generally, the the major component of precipitation chemistry were SO42- and NO3-, Ca+ and NH4+, for anion and cations, respectively. The largest proportions of the total anions in all sampling sites was SO42- ranged from 32% (Lembang) to 37% (Buah Batu) followed by NO3- (13 – 15%) and and Cl- (4 – 7%). For cations, NH4+ dominated with proportion ranged between 21 – 27% and subsequently Ca2+ (13 – 19%) and followed by Na+, Mg+, K+ and H+. The Neutralizing Factor (NF) results reveal that Ca2+ and NH4+ are the dominant neutralization substances in the rainwater. However it should be noted that reduced nitrogen (NH4+) act as mobile nitrogen that further will acidify the environment, particularly to soil ecosystem downstreams.

scholarly journals Long term precipitation chemistry and wet deposition in a remote dry savanna site in Africa (Niger)

2009 ◽  
Vol 9 (5) ◽  
pp. 1579-1595 ◽  
Author(s):  
C. Galy-Lacaux ◽  
D. Laouali ◽  
L. Descroix ◽  
N. Gobron ◽  
C. Liousse
Keyword(s):  
Wet Deposition ◽  
Ph Value ◽  
Precipitation Chemistry ◽  
Annual Rainfall ◽  
Deposition Flux ◽  
Air Concentration ◽  
Ionic Charge ◽  
Rainfall Gradient ◽  
The Mean

Abstract. Long-term precipitation chemistry have been recorded in the rural area of Banizoumbou (Niger), representative of a semi-arid savanna ecosystem. A total of 305 rainfall samples ~90% of the total annual rainfall) were collected from June 1994 to September 2005. From ionic chromatography, pH major inorganic and organic ions were detected. Rainwater chemistry is controlled by soil/dust emissions associated with terrigeneous elements represented by SO42−, Ca2+, Carbonates, K+ and Mg2+. It is found that calcium and carbonates represent ~40% of the total ionic charge. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) for NO3− and NH4+ concentrations of 11.6 and 18.1 μeq.l−1, respectively. This is the signature of ammonia sources from animals and NOx emissions from savannas soil-particles rain-induced. The mean annual NH3 and NO2 air concentration are of 6 ppbv and 2.6 ppbv, respectively. The annual VWM precipitation concentration of sodium and chloride are both of 8.7 μeq.l−1 which reflects the marine signature of monsoonal and humid air masses. The median pH value is of 6.05. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8μeq.l−1 and 5.2 μeq.l−1 of formate and acetate were also found. The analysis of monthly Black Carbon emissions and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) values show that both biogenic emission from vegetation and biomass burning could explain the rainfall organic acidity content. The interannual variability of the VWM concentrations around the mean (1994–2005) is between ±5% and ±30% and mainly due to variations of sources strength and rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is of 60.1 mmol.m−2.yr−1 ±25%. Finally, Banizoumbou measurements are compared to other long-term measurements of precipitation chemistry in the wet savanna of Lamto (Côte d'Ivoire) and in the forested zone of Zoétélé (Cameroon). The total chemical loading presents a maximum in the dry savanna and a minimum in the forest (from 143.7, 100.2 to 86.6 μeq.l−1), associated with the gradient of terrigeneous sources. The wet deposition fluxes present an opposite trend, with 60.0 mmol.m−2.yr−1 in Banizoumbou, 108.6 mmol.m−2.yr−1 in Lamto and 162.9 mmol.m−2.yr−1 in Zoétélé, controlled by rainfall gradient along the ecosystems transect.

scholarly journals Long term precipitation chemistry and wet deposition in a remote dry savanna site in Africa (Niger)

2008 ◽  
Vol 8 (2) ◽  
pp. 5761-5812 ◽  
Author(s):  
C. Galy-Lacaux ◽  
D. Laouali ◽  
L. Descroix ◽  
N. Gobron ◽  
C. Liousse
Keyword(s):  
Wet Deposition ◽  
Ph Value ◽  
Precipitation Chemistry ◽  
Annual Rainfall ◽  
Deposition Flux ◽  
Air Concentration ◽  
Ionic Charge ◽  
Rainfall Gradient ◽  
The Mean

Abstract. A long-term measurement of precipitation chemistry has been carried-out in a rural area of Banizoumbou, in the Sahel (Niger), representative of the african semi-arid savanna ecosystem. A total of 305 rainfall samples, representing 90% of the total annual rainfall, were collected with an automatic wet-only rain sampler from June 1994 to September 2005. Using ionic chromatography, pH major inorganic and organic ions were analyzed. Rainwater chemistry at the site is controlled by soil dust emissions associated to a strong terrigeneous contribution represented by SO42–, Ca2+, Carbonates, K+ and Mg2+. Calcium and carbonates represent about 40% of the total ionic charge of precipitation. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) NO3– and NH4+, concentrations of 11.6 and 18.1 μeq.l−1, respectively. This is thesignature of ammonia sources related to animals and NOx emissions from savannas soils rain-induced, at the beginning of the rainy season. The mean annual NH3 and NO2 air concentration are of 6 ppbv and 2.6 ppbv, respectively. The annual VWM precipitation concentration of sodium and chloride are both of 8.7 μeq.l−1 and reflects the marine signature from the monsoon humid air masses coming from the ocean. The mean pH value, calculated from the VWM of H+, is 5.64. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8 μeq.l−1 and 5.2 μeq.l−1 of formate and acetate were found, respectively. The analysis of monthly Black Carbon emissions and FAPAR values show that both biogenic emission from vegetation and biomass burning sources could explain the organic acidity content of the precipitation. The interannual variability of the VWM concentrations around the mean (1994–2005) presents fluctuations between ±5% and ±30% mainly attributed to the variations of sources strength associated with rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is 60.1 mmol.m−2.yr−1 and fluctuates around ±25%. Finally, Banizoumbou measurements, are compared to other long-term measurements of precipitation chemistry in the wet savanna of Lamto (Côte d'Ivoire) and in the forested zone of Zoétélé (Cameroon). The total chemical loadings presents a strong negative gradient from the dry savanna to the forest (143.7, 100.2 to 86.6 μeq.l–1), associated with the gradient of terrigeneous compounds sources. The wet deposition fluxes present an opposite gradient, with 60.0 mmol.m−2.yr−1 in Banizoumbou, 108.6 mmol.m−2.yr–1 in Lamto and 162.9 mmol.m−2.yr−1 in Zoétélé, controlled by the rainfall gradient along the ecosystems transect.

scholarly journals POS0998 SPONDYLOARTHRITIS AND SLEEP DISORDERS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 767.2-768
Author(s):  
S. Lahrichi ◽  
K. Nassar ◽  
S. Janani
Keyword(s):  
Functional Impairment ◽  
Sleep Disturbances ◽  
Negative Impact ◽  
University Hospital ◽  
Quality Of Sleep ◽  
The Mean ◽  
Sleep Deficit ◽  
Impaired Sleep ◽  
The Impact

Background:Spondyloarthropathies (SpA) are a group of chronic and progressive diseases, characterized in particular by a progressive stiffening of the spine, spreading to neighboring joints or to certain tissues, which could lead in the long term to progressive stiffening and functional impairment. This conditioncancauseinsomnia problems and impaired sleep quality.Objectives:To assess the impact of SpA on the quality of sleep.Methods:This is a retrospective study over a period of 4 years from January 2015 to December 2019, including all the medical records of patients with SpA followed in the Department of Rheumatology of the University Hospital of Ibn Rochd, Casablanca. We evaluated for each patient two validated scores: the Epworth somnolence scale rated from 0 to 24, and the Pittsburgh sleep score rated from 0 to 21 with 7 components. Patients with a psychiatric history or who were followed up for neurological pathologies were excluded.Results:178 patients were included. 60.67% were men with an average age of 36.32 years (14-68 years). 45.01% had axial SpA, 29.77% had psoriatic arthritis, and 25.22% were followed for SpA associated with inflammatory bowel disease. 45% had associated comorbidities: there were 18 diabetics and 34 hypertensive, 16.58% were smokers. Clinically, 85.42% presented a back pain initially on examination, 55% presented a polyarthralgia, and 39.88% an oligoarthritis. 63% had radiological sacroiliitis, and 35.14% had bilateral coxitis. 13.48% had a positive HLA B27 and 58.89% had a positive inflammatory assessment with very high activity indices,with a mean of 4.6. 64.66% of the patients received NSAIDs,of which 11% responded well. 57% were treated with csDMARDs, and 17.86% were treated with biologics. At the time of our study, the mean visual analog scale was 5.84 ± 1.7 out of 10 (2-9). The mean Epworth score was 8.38 ± 5.2 (0-21). 56.1% of patients had no sleep debt, 33.3% had a sleep deficit, and only 10.6% had signs of drowsiness. For the overall Pittsburgh score, the mean was 7.02 ± 3.6 (1-18). The mean of “subjective quality of sleep” was 1.12, “sleep latency” was 1.22, “duration of sleep” was 1.06, “usual sleep efficiency” was 0.74, “Sleep disturbance” of 1.28, “use of a sleep medication” of 0.54, and the average of the component concerning “poor shape during the day” was 1.03 out of 3. The LEQUESNE index went from an average of 6 to 8, which corresponds to an average handicap (P = 0.2) over a period of 3 years. 68% of the patients had an alteration in the quality of sleep, starting on average three years after the onset of symptoms. 11% reported having experiencedanxiety and depressive symptoms, and reported having used antidepressants or anxiolytics in the past 5 years.Conclusion:Our study showed the negative impact of SpA on the duration and overall quality of sleep. The degree of pain as well as functional impairment can cause and worsen sleep disturbances in SpA. We have shown that the Pittsburg score increases significantly with the increase of pain.The Lequesne score and that the Epworth score increase with disease activity[1].References:[1]StolwijkC,vanTubergenA,Castillo-OrtizJD,BoonenA.Prevalenceofextra-articularmanifestationsinpatientswithankylosingspondylitis:asystematicreviewandmeta-analysis.AnnRheumDis2015;74:65—73.Disclosure of Interests:None declared.

Fatigue Assessment of Mooring Chain Considering the Effects Of Mean Load and Corrosion

2021 ◽  
Author(s):  
Erling N. Lone ◽  
Thomas Sauder ◽  
Kjell Larsen ◽  
Bernt J. Leira
Keyword(s):  
Negative Impact ◽  
Fatigue Tests ◽  
Design Practice ◽  
Extended Formulation ◽  
Considerable Influence ◽  
Corrosion Condition ◽  
Capacity Model ◽  
Significant Negative Impact ◽  
The Mean ◽  
Mooring Chain

Abstract Results from full scale fatigue tests of offshore mooring chains performed in recent years have revealed considerable influence of both mean load and corrosion condition on the fatigue capacity. It has been shown that a reduction of the mean load gives an increase in fatigue life, whereas the corrosion experienced by used chains have a significant negative impact. Neither of these effects are properly addressed by current S-N design curves or design practice. This paper suggests an extended S-N curve formulation, that includes the effects of mean load and corrosion condition. The parameters of the extended formulation are estimated empirically from mooring chain test data that includes new and used chains, with various mean loads and with different degrees of corrosion. The fitted capacity model is then used for fatigue calculation for the mooring system of a semi-submersible, showing the importance of using realistic mean loads and mooring chain corrosion in fatigue assessments.

scholarly journals Day-Ahead Forecast of Electric Vehicle Charging Demand with Deep Neural Networks

2021 ◽  
Vol 12 (4) ◽  
pp. 178
Author(s):  
Gilles Van Van Kriekinge ◽  
Cedric De De Cauwer ◽  
Nikolaos Sapountzoglou ◽  
Thierry Coosemans ◽  
Maarten Messagie
Keyword(s):  
Neural Network ◽  
Electric Vehicles ◽  
Negative Impact ◽  
Absolute Error ◽  
Electric Grid ◽  
Electric Vehicle Charging ◽  
The Neural Network ◽  
The Mean ◽  
Ev Charging ◽  
Charging Demand

The increasing penetration rate of electric vehicles, associated with a growing charging demand, could induce a negative impact on the electric grid, such as higher peak power demand. To support the electric grid, and to anticipate those peaks, a growing interest exists for forecasting the day-ahead charging demand of electric vehicles. This paper proposes the enhancement of a state-of-the-art deep neural network to forecast the day-ahead charging demand of electric vehicles with a time resolution of 15 min. In particular, new features have been added on the neural network in order to improve the forecasting. The forecaster is applied on an important use case of a local charging site of a hospital. The results show that the mean-absolute error (MAE) and root-mean-square error (RMSE) are respectively reduced by 28.8% and 19.22% thanks to the use of calendar and weather features. The main achievement of this research is the possibility to forecast a high stochastic aggregated EV charging demand on a day-ahead horizon with a MAE lower than 1 kW.

scholarly journals The prediction model of moisture content’s stabilization during tobacco strip drying process

2018 ◽  
Author(s):  
Mingjian Zhang ◽  
Feng Huang ◽  
Qing Chen ◽  
Le Wang ◽  
Haisheng Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Probability Distributions ◽  
Chemical Properties ◽  
Mean Value ◽  
Drying Process ◽  
Variance Model ◽  
Initial Stage ◽  
The Mean ◽  
Agriculture Products ◽  
Physical And Chemical

A mathematical model was established to predict the mean value and variance of tobacco strip during drying processing, based that the physical and chemical properties of tobacco strip as agriculture products show probability distributions. The results show that the model can predict the mean value of moisture content at different times, and there is a certain deviation in predicting the variance of moisture content at initial stage of drying process. However, the prediction value of the variance of tobacco strip is much more accurate while the moisture content is between 8% and 10%, which is the interval of quality requirements.Keywords: tobacco strip; drying; mean value;variance model.  

scholarly journals Effect of Land Use on Soil Quality in Afaka Forest Northern Guinea Savannah of Nigeria

2019 ◽  
pp. 1-12
Author(s):  
H. Haruna
Keyword(s):  
Land Use ◽  
Soil Fertility ◽  
Bulk Density ◽  
Soil Quality ◽  
Negative Impact ◽  
Land Use Changes ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Cultivated Land ◽  
Soil Fertility Management

Land use changes from forest into cultivated ecosystems result in negative impact on soil structure and quality. The purpose of this study was to determine effect of land use on soil quality in Afaka forest northern guinea savannah of Nigeria. Land use systems, including natural forest and cultivated land were identified. Eighteen (18) composite disturbed and undisturbed samples were collected from depth of 0-5 and 5-10 cm for analysis of pertinent soil properties in the laboratory using grid procedure. Most physical and chemical properties show relative variations in response to land use types and geomorphic positions. Results  indicate  that the soils had  high degree of weathering potentials, low  to moderate  bulk density at 0-5cm depth values between 1.42 to 1.49 Mg m-3 in  forest and  cultivated land, bulk density of  1.34 and 1.46 1.Mg m-3at 5 -1ocm depth   for forest and  cultivated land respectively. The soil water at 0-5cm depth is from 4.20 to 2.63 cm3/cm3, while at 5-10 cm depth these values vary from 4.32 to 2.13 cm3/cm3 under forest and cultivation land use. The pH (H2O) is 6.9 to 7.16 with low electrical conductivity of 0.13 dS/m(forest) and 0.12 dS/m (cultivation). The CEC of soils is recorded as 8.60 cmol kg-1 (forest) to 8.54 cmol kg-1 (cultivated)whereas  total nitrogen content of 1.21 g kg-1 and 1.11 g kg-1 and available phosphorus of 8.78 mg kg-1 (cultivated) and 5.47 mg kg-1 (forest).. Results indicate that soil fertility parameters were moderate to low for cultivated land and at all slope positions, suggesting that soil fertility management is required in order to make agriculture sustainable on Afaka area.

scholarly journals Geochemical And Mineralogical Assessment Of Secondary Gypsum In Al-Najaf, Iraq And Employment As Raw Material For Cement Industry

2021 ◽  
Vol 72 ◽  
pp. 215-222
Author(s):  
Mohanad R.A. Al-Owaidi ◽  
◽  
Mohammed L. Hussein ◽  
Ruaa Issa Muslim ◽  
◽  
...  
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Chemical Properties ◽  
Quality Standard ◽  
Cement Industry ◽  
Raw Material ◽  
Insoluble Residue ◽  
Mineralogical Study ◽  
The Mean ◽  
Industry Success

The Portland cement industry is one of the strategic industries in any country. The basis of an industry success is the availability of raw materials and, the low extraction in addition to transportation costs. The Bahr Al-Najaf region is abundant with limestone rocks but lacks primary gypsum. An investigation had been carried out to identify the source of secondary gypsum as an alternative to primary gypsum. Twelve boreholes were drilled for a depth of 2 m, as the thickness of suitable secondary gypsum layer ranges from 1 to 1.5 m. The mineralogical study revealed the predominance of gypsum followed by quartz and calcite, with an average of 62.9%, 19.6% and 14.35%, respectively. The geochemical analysis revealed that the content of SO3 is appropriate and ranging from 41.92% to 32.89% with an average of 37.73%. The SO3 content is within an acceptable range. The mean abundance of the major oxides of the study area may be arranged as SO3 > CaO> SiO2> MgO> Al2O> Fe2O3. The insoluble residue was at an acceptable rate. The laboratory experiments for milling secondary gypsum with clinker has successfully proven the production of Portland cement that matches the limits of the Iraqi Quality Standard (IQS) No. 5 of 1984. Great care must be taken when using secondary gypsum; secondary gypsum must be mixed well to maintain the chemical properties before blending with clinker and utilizing in the cement mill in the cement plant.

scholarly journals Torrefaction of Food Waste as a Potential Biomass Energy Source

2019 ◽  
Vol 19 (4) ◽  
pp. 993
Author(s):  
Rahsya Nur Udzaifa Abdul Rahman ◽  
Mazni Ismail ◽  
Ruwaida Abdul Rasid ◽  
Noor Ida Amalina Ahamad Nordin
Keyword(s):  
Energy Source ◽  
Residence Time ◽  
Food Waste ◽  
Negative Impact ◽  
Chemical Properties ◽  
Biomass Energy ◽  
Energy Yield ◽  
Energy Potential ◽  
Ultimate Analysis

Food waste (FW) represents a major component of municipal solid waste (MSW) in Malaysia which causes negative impact due to poor waste management. One of a promising strategy to reduce the FW is to convert the FW to energy sources through thermal pre-treatment process which known as torrefaction. The aim of this study is to investigate the improvement of chemical properties and energy potential of the torrefied FW. The torrefaction of FW was conducted using tubular reactor to evaluate the influence of temperature (220 to 260°C) and residence time (15 to 60 min) on the quality of torrefied FW. The quality of torrefied FW were evaluated using ultimate analysis, proximate analysis, mass yield, energy yield and higher heating value (HHV). From ultimate analysis, the carbon, C was increased, however the hydrogen, H and oxygen, O decreased across the torrefaction temperature and residence time. This lead to the increasing of HHV with the increasing of temperature and time. The HHV of the dried FW was improved from 19.15 to 23.9 MJ/kg after being torrefied at 260°C for 60 min. The HHV indicated that FW has the potential to be utilized as an energy source.

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