scholarly journals Evaluation of Long-Term Leaching of Arsenic from Arsenic Contaminated and Stabilized Soil Using the Percolation Column Test

2021 ◽  
Vol 11 (17) ◽  
pp. 7859
Author(s):  
Gayatri Panthi ◽  
Jaeyoung Choi ◽  
Seung-Woo Jeong
Keyword(s):  
Contaminated Soil ◽  
Mine Drainage ◽  
Steel Slag ◽  
Ionic Species ◽  
Column Test ◽  
Ph Changes ◽  
Initial Stage ◽  
Contaminate Drinking Water ◽  
Stabilized Soil

Arsenic in the soil can leach into groundwater and contaminate drinking water, posing a serious risk to human health. The stabilization of arsenic in contaminated soil is one of the immobilization technologies used to remediate contaminated lands. However, few studies have evaluated the long-term release of As and pH changes in stabilized soils. We compared different stabilization techniques in the field by mixing contaminated soil with 5% of either acid mine drainage sludge (AMDS), coal mine drainage sludge (CMDS), steel slag, or cement. We evaluated the results using an up-flow percolation column test to observe any pH changes and As releases from the stabilized soils up to a liquid–solid (L/S) ratio of 50 (approximately representing a 50 year period). At the initial stage of percolation (at an L/S ratio of 0.2 or 0.2 of a year of exposure), some alkaline components and any incompletely bound As in the soils washed out with the eluent. The pH of the cement-stabilized soil was approximately 12 throughout the experiment (up to 50 L/S). Adding stabilizers to the soil reduced As leaching by 54–81% (overall efficiency) compared to the control (contaminated soil only). The order of stabilization efficiency was: steel slag (55.0%) < AMDS (74.3%) < cement (78.1%) < CMDS (81.5%). This study suggests that the groundwater of the stabilized soil should be carefully monitored for the initial five years because the soluble ionic species can leach over this period.

Soil remediation approach and bacterial community structure in a long-term contaminated soil by a mining spill (Aznalcóllar, Spain)

2021 ◽  
Vol 777 ◽  
pp. 145128
Author(s):  
M. Paniagua-López ◽  
M. Vela-Cano ◽  
D. Correa-Galeote ◽  
F. Martín-Peinado ◽  
F.J. Martínez Garzón ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Soil Remediation ◽  
Contaminated Soil ◽  
Bacterial Community Structure

scholarly journals A Novel Deep Learning Approach for Machinery Prognostics Based on Time Windows

2019 ◽  
Vol 9 (22) ◽  
pp. 4813 ◽  
Author(s):  
Hanbo Yang ◽  
Fei Zhao ◽  
Gedong Jiang ◽  
Zheng Sun ◽  
Xuesong Mei
Keyword(s):  
Time Windows ◽  
Remaining Useful Life ◽  
Sensor Data ◽  
Time Interval ◽  
Kernel Module ◽  
Initial Stage ◽  
Research Task ◽  
Consecutive Time ◽  
Useful Life

Remaining useful life (RUL) prediction is a challenging research task in prognostics and receives extensive attention from academia to industry. This paper proposes a novel deep convolutional neural network (CNN) for RUL prediction. Unlike health indicator-based methods which require the long-term tracking of sensor data from the initial stage, the proposed network aims to utilize data from consecutive time samples at any time interval for RUL prediction. Additionally, a new kernel module for prognostics is designed where the kernels are selected automatically, which can further enhance the feature extraction ability of the network. The effectiveness of the proposed network is validated using the C-MAPSS dataset for aircraft engines provided by NASA. Compared with the state-of-the-art results on the same dataset, the prediction results demonstrate the superiority of the proposed network.

Long-term performance of a UASB reactor treating acid mine drainage: effects of sulfate loading rate, hydraulic retention time, and COD/SO42− ratio

2018 ◽  
Vol 30 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Mirabelle Perossi Cunha ◽  
Rafael Marçal Ferraz ◽  
Giselle Patrícia Sancinetti ◽  
Renata Piacentini Rodriguez
Keyword(s):  
Acid Mine Drainage ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Mine Drainage ◽  
Uasb Reactor ◽  
Acid Mine ◽  
Long Term Performance ◽  
Term Performance

Effect of Lime on Compaction, Strength and Consolidation Characteristics of Pontian Marine Clay

2015 ◽  
Vol 72 (3) ◽  
Author(s):  
Siaw Yah Chong ◽  
Khairul Anuar Kassim
Keyword(s):  
Construction Material ◽  
Soft Clay ◽  
Engineering Properties ◽  
Dry Density ◽  
Marine Clay ◽  
Maximum Dry Density ◽  
Stabilization Phase ◽  
Compaction Curve ◽  
Stabilized Soil

Marine clay is a problematic construction material, which is often encountered in Malaysian coastal area. Previous researchers showed that lime stabilization effectively enhanced the engineering properties of clay. For soft clay, both strength and consolidation characteristics are equally important to be fully understood for design purpose. This paper presented the effect of lime on compaction, strength and consolidation characteristics of Pontian marine clay. Compaction, unconfined compression, direct shear, Oedometer and falling head permeability tests were conducted on unstabilized and lime stabilized samples at various ages. Specimens were prepared by compaction method based on 95 percent maximum dry density at the wetter side of compaction curve. It was found that lime successfully increased the strength, stiffness and workability of Pontian marine clay; however, the permeability was reduced. Unconfined compressive strength of stabilized soil was increased by 49 percent at age of 56 days whereas compressibility and permeability was reduced by 48 and 67 percent, respectively. From laboratory tests, phenomenon of inconsistency in engineering characteristics was observed for lime stabilized samples below age of 28 days. This strongly proved that lime stabilized soil underwent modification phase before stabilization phase which provided the long term improvement.

scholarly journals FCCSP IMC growth under reliability stress follows automotive criteria

2019 ◽  
Vol 3 (1) ◽  
pp. 70-83
Author(s):  
Wei Wei Liu ◽  
Berdy Weng ◽  
Scott Chen
Keyword(s):  
High Temperature ◽  
Flip Chip ◽  
Stress Test ◽  
Temperature Cycling ◽  
Content Type ◽  
Initial Stage ◽  
High Temperature Storage ◽  
Temperature Cycling Test ◽  
Temperature Storage

Purpose The Kirkendall void had been a well-known issue for long-term reliability of semiconductor interconnects; while even the KVs exist at the interfaces of Cu and Sn, it may still be able to pass the condition of unbias long-term reliability testing, especially for 2,000 cycles of temperature cycling test and 2,000 h of high temperature storage. A large number of KVs were observed after 200 cycles of temperature cycling test at the intermetallic Cu3Sn layer which locate between the intermetallic Cu6Sn5 and Cu layers. These kinds of voids will grow proportional with the aging time at the initial stage. This paper aims to compare various IMC thickness as a function of stress test, the Cu3Sn and Cu6Sn5 do affected seriously by heat, but Ni3Sn4 is not affected by heat or moisture. Design/methodology/approach The package is the design in the flip chip-chip scale package with bumping process and assembly. The package was put in reliability stress test that followed AEC-Q100 automotive criteria and recorded the IMC growing morphology. Findings The Cu6Sn5 intermetallic compound is the most sensitive to continuous heat which grows from 3 to 10 µm at high temperature storage 2,000 h testing, and the second is Cu3Sn IMC. Cu6Sn5 IMC will convert to Cu3Sn IMC at initial stage, and then Kirkendall void will be found at the interface of Cu and Cu3Sn IMC, which has quality concerning issue if the void’s density grows up. The first phase to form and grow into observable thickness for Ni and lead-free interface is Ni3Sn4 IMC, and the thickness has little relationship to the environmental stress, as no IMC thickness variation between TCT, uHAST and HTSL stress test. The more the Sn exists, the thicker Ni3Sn4 IMC will be derived from this experimental finding compare the Cu/Ni/SnAg cell and Ni/SnAg cell. Research limitations/implications The research found that FCCSP can pass automotive criteria that follow AEC-Q100, which give the confidence for upgrading the package type with higher efficiency and complexities of the pin design. Practical implications This result will impact to the future automotive package, how to choose the best package methodology and what is the way to do the package. The authors can understand the tolerance for the kind of flip chip package, and the bump structure is then applied for high-end technology. Originality/value The overall three kinds of bump structures, Cu/Ni/SnAg, Cu/SnAg and Ni/SnAg, were taken into consideration, and the IMC growing morphology had been recorded. Also, the IMC had changed during the environmental stress, and KV formation was reserved.

scholarly journals The external environment of birds as a factor of immunobiochemical conditions

2020 ◽  
Vol 9 (3) ◽  
pp. 152-157
Author(s):  
Rinat R. Fatkullin ◽  
Aikumis K. Saken
Keyword(s):  
Metabolic Disorders ◽  
Clinical Manifestations ◽  
The Body ◽  
Household Waste ◽  
Trophic Chain ◽  
Behavioral Strategies ◽  
The Public ◽  
Initial Stage ◽  
Highly Sensitive

Abnormal environmental factors contribute to advanced behavioral strategies in higher regulatory centers as well as to the assessment of possible morphofunctional and energy transformations in the body. Animals, especially birds, which are characterized by curiosity, are highly sensitive to the presence of environmental pollution, since they interact with elements of the environment and surroundings. Contamination of broiler products can also be caused by contaminated soil and dust, unknown sources of persistent heavy metals and organic pollutants that are unknown to the public, such as car wreckage, household waste, and so on. In general, adverse factors that regularly affect small details do not require significant changes in the body at the initial stage, mainly affect non-specific mechanisms that lead to long-term activation. The paper contains significant work based on the analysis of microbiogenic links in the trophic chain, but the formation of processes associated with metabolic disorders from the development of trace elements to clinical manifestations is still insufficiently studied, so it is difficult to diagnose and treat previously unknown animal diseases in veterinary practice.

scholarly journals PROBLEMS OF ACCOUNTING FIXED ASSETS AT THE ENTERPRISE

2020 ◽  
Vol 11 (87) ◽  
Author(s):  
Iryna Feofanova ◽  
◽  
Olgha Antonova ◽  
Keyword(s):  
Production Capacity ◽  
Economic Resources ◽  
Economic Conditions ◽  
Accounting System ◽  
Normative Documents ◽  
Initial Stage ◽  
Fixed Assets ◽  
Modern Economic ◽  
Effective Use

The article is devoted to topical issues of improving the methodology and organization of fixed assets accounting. Fixed assets play a huge role in the labor process, as they together form the production – technical base and determine the production capacity of the enterprise. Their condition directly affects the activities of the enterprise, namely its continuous operation. Over a long period of use, fixed assets enter the enterprise and are put into operation; wear out as a result of operation; are repaired, by means of which their physical qualities are restored; leave the enterprise due to obsolescence or inexpediency of further use. Fixed assets used in enterprises in modern economic conditions are one of the most important economic resources. Fixed assets, formed at the initial stage of the organization, require constant management. In the process of accounting at enterprises there are a number of problems of methodological and practical nature in the organization of accounting, valuation and depreciation of fixed assets. In the course of writing the article, the economic characteristics and concepts of fixed assets, theoretical aspects of fixed assets accounting, normative documents related to the researched problem were investigated. The analysis of fixed assets can be carried out in several areas, the development of which in the complex allows to assess the structure, dynamics and efficiency of fixed assets and long-term investments. Options for solving problems in accordance with modern economic conditions are revealed. The correct organization of accounting of fixed assets ensures the efficiency of their use, the timeliness of determining and reflecting transactions with changes that occur with them, the completeness of the reflection of these changes in value terms in accounting. Thus, the fixed asset accounting system needs to be improved. A comprehensive approach to the organization of fixed assets accounting is needed, which is able to provide the necessary conditions and opportunities for the use of valuable accounting information to make management decisions on the evaluation and effective use of fixed assets.

scholarly journals Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea

2021 ◽  
Vol 11 ◽  
Author(s):  
Joon Sung Kim ◽  
Jun Chul Park ◽  
Jong Yeul Lee ◽  
Ji Yong Ahn ◽  
Sun Hyung Kang ◽  
...  
Keyword(s):  
Overall Survival ◽  
Malt Lymphoma ◽  
Case Series ◽  
Stage Iii ◽  
Gastric Malt Lymphoma ◽  
University Hospitals ◽  
Initial Stage ◽  
Testing Stage ◽  
H Pylori

BackgroundTreatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage.MethodsPatients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected.ResultsA total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival.ConclusionThe majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.

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