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2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Xiao ◽  
Enlong Liu ◽  
Xiao Yin ◽  
Guike Zhang ◽  
Chong Zhang ◽  
...  

PurposeThe purpose of this paper is to perform the thermo-hydro-mechanical (THM) numerical analysis in order to study the thawing process for frozen soil and to predict the thawing settlement.Design/methodology/approachA new one-dimensional multi-field physical coupled model was proposed here to describe the thawing process of saturated frozen soil, whereby the void ratio varied linearly with effective stress (Eq. 10) and hydraulic conductivity (Eq. 27b). The thawing process was simulated with different initial and boundary conditions in an open system with temperature variations. The mechanical behavior and water migration of the representative cases were also investigated.FindingsThe comparisons of representative cases with experimental data demonstrated that the model predicts thawing settlement well. It was found that the larger temperature gradient, higher overburden pressure and higher water content could lead to larger thawing settlement. The temperature was observed that to distribute height linearly in both frozen zone and unfrozen zone of the sample. Water migration forced to a decrease in the water content of the unfrozen zone and an increase in water content at the thawing front.Research limitations/implicationsIn this study, only the one-directional thawing processes along the frozen soil samples were investigated numerically and compared with test results, which can be extended to two-dimensional analysis of thawing process in frozen soil.Originality/valueThis study helps to understand the thawing process of frozen soil by coupled thermo-hydro-mechanical numerical simulation.


2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Rafi Amartya Santosa ◽  
Rizky Ariyan Qurais Shihab ◽  
Adamzah Suyuti Bakar ◽  
Joni Welman Simatupang

The purpose of this research (study) is to demonstrate the superiority of the wireless sensor network (WSN) technology method over the laboratory method in monitoring the water quality of the Citarum River in Karawang. To monitor the Citarum river water quality, government of Karawang regency conducted a test by taking the sample water to the laboratory. It seems to be such a conventional method. With the results of the BOD value obtained from the DLHK data, which is 47.93 mg/L, of course it will be a problem for the development of milkfish. However, an advanced method using Wireless Sensor Network (WSN) technology seems to be an alternative. Basically, this technology can monitor the water quality in real-time using multiple parameters and help cultivators to monitor the water used in milkfish cultivation. Of course WSN technology is more efficient than waiting for laboratory results.  Therefore, if this technology is applied, the data will be obtained in real time.  Of course the data can be processed and monitored directly to determine the quality of the water used.  In terms of cost, this technology can be built at a moderate cost compared to laboratory work.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Bhishma Karki ◽  
Saddam Husain Dhobi ◽  
Indra Dhobi ◽  
Digvijay Pandey ◽  
Binay Kumar Pandey

AbstractThe optical properties of two water supply samples Kathmandu Upatyaka Khanepani Limited (KUKL) and Kathmandu Valley Water Supply Improvement Project (KVWSIP) in the Kupondole Area, Lalitpur, Nepal show that the transmittance of light is higher for KVWSIP sample water than for KUKL. A large amount of work has been done to test the purities of KUKL and KVWSIP water supplies (chemically), but even their optical properties have not been studied. This method has no hazardous side effects or requires chemical method testing. In comparing the optical properties, the authors recommended that the public take KVWSIP water for good health and wealth rather than KUKL if they have an option.This is because KUKL is more contaminated and has more total dissolved solids (TDS) particles, while KVWSIP has fewer TDS particles. Therefore, if people take KVWSIP water in their daily life, they obtain relief from different types of water-related diseases.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dana-Céline Krause ◽  
Sebastian Mangelsen ◽  
Christian Näther ◽  
Wolfgang Bensch

Abstract The new compound K2[Ni(dien)2]{[Ni(dien)]2Ta6O19}·11 H2O crystallized at room temperature applying a diffusion based reaction in a H2O/DMSO mixture using K8{Ta6O19}·16 H2O, Ni(NO3)2·6H2O and dien (diethylenetriamine). In the crystal structure, the Lindqvist-type anion [Ta6O19]8– is structurally expanded by two octahedrally Ni2+-centered complexes via three Ni–µ 2-O–Ta bonds thus generating the new {[Ni(dien)]2Ta6O19}4– anion. Two KO8 polyhedra share a common edge to form a K2O14 moiety, which connects the {[Ni(dien)]2Ta6O19}4– cluster shells into chains. The isolated [Ni(dien)2]2+ complexes are located in voids generated by the structural arrangement of the chains. An extended hydrogen bonding network between the different constituents generates a 3D network. The crystal water molecules can be thermally removed to form a highly crystalline dehydrated compound. Partial water uptake leads to the formation of a crystalline intermediate with a reduced unit cell volume compared to the fully hydrated sample. Water sorption experiments demonstrate that the fully dehydrated sample can be fully reconverted to the hydrated compound. The crystal field splitting parameters for the octahedrally coordinated Ni2+-centered complexes have been evaluated from an UV/Vis spectrum yielding D q = 1056 cm−1 and B = 887 cm−1.


Author(s):  
Gandhimathi A ◽  
Naresh K

Analyzing of water quality at Ooty town and to provide clean and safe water. The water quality is analyzed and tabulated in this paper. So we are able to know the quality of water available in the sample taken. The water analyzed about the chemical, physical and biological characteristics of water. It is used to measure the appearance of sample water for the need of living. Water samples are collected from the open well (Latitude and longitude coordinates are 11.410000, 76.699997). The samples were tested for parameters like pH, turbidity, total hardness, fluoride, dissolved oxygen, ammonia nitrogen, chemical oxygen demand, acidity, and alkalinity. The values which are obtained from each parameter were compared with the Indian Standards: 10500 (Drinking water specifications). During the summer season the water demand is very high hence from the result the water was found to be safe for drinking.


2021 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Selvi Ariyunita ◽  
Yeny Dhokhikah ◽  
Wachju Subchan

Microplastics are harmful to the ecosystem and need to solve immediately. Detection of microplastic contamination is the first step to reduce plastics pollution. Estuarine in Puger has a high potential for microplastic pollution related to the multifunction of waters as ports, tourism, fish market, fish processing, and human settlements. However, there are no studies related to microplastic contamination in the area. The objectives of this research were to determine microplastic contamination in the estuarine located in Puger District, Jember Regency, Indonesia. The research results were the first evidence to inform the society and local government about the actual condition of plastic pollution, especially in the aquatic ecosystem. The sampling sites were determined by purposive sampling. Fifty liters of water from each station (with three repetitions) were taken using a 24V water pump and then filtered using stainless steel filter (mesh 5 mm and 0.2 mm). The filtered samples were placed in a sterile bottle sample, stored at 4 ± 20C. Microplastics were counted and categorized according to size, color, and type under a microscope stereo. Microplastic abundance was calculated based on the number of microplastic particles identified per liter of sample water (particle/liter). The result showed that the study area was contaminated by microplastics throughout site sampling, with abundances varying from 0.03 particles/liter to 0.19 particles/liter. The highest microplastic abundance found near the fishery market. The microplastics also vary in size, color, and type. According to characterization, the sources of microplastic contamination come from human-based activities.


2021 ◽  
Vol 4 ◽  
Author(s):  
Philippe Blancher ◽  
Estelle Lefrançois ◽  
Frederic Rimet ◽  
Agnès Bouchez

Recent developments in the use of environmental DNA are opening up new horizons for the assessment of the quality of aquatic environments. These rapid and cost-effective methods, in very swift progress, will potentially offer the opportunity to identify all the taxa present in an environmental sample (water or biota) by the use of complementary markers. The produced inventories can then be used for the assessment of biodiversity and ecological quality. However, the inclusion of these new DNA-based methods in monitoring practices is not straightforward and requires harmonised actions in the coming years at national and international levels. In order to foresee and stimulate such a harmonised implementation, the European network DNAqua-Net (COST Action CA15219) brought together some of its members, experts of ECOSTAT and other environmental biomonitoring stakeholders from different European countries. Through workshops, bringing together 51 participants in 7 sub-groups in April 2020, an implementation roadmap was designed. The coordinated actions to be taken in the different countries, and the possible collaborations and steps to be taken at the EU level were identified. This presentation will give an overview of all discussions (Lefrançois et al. 2020) reflecting the diversity of situations in Europe, as well as common views. We will highlight important actions required for a successful implementation of DNA-based biomonitoring of aquatic ecosystems to the horizon of 2030.


2021 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Rizki Nugrahani ◽  
Yayuk Andayani ◽  
Aliefman Hakim

Research has been carried out on the analysis of physic properties of green bean extract powder (Phaseolus vulgaris L). This study aims to determine the physical characteristics of the bean extract powder that has been stored in a predetermined time variation. The physic properties tested included water content, solubility and organoleptic tests. The results of the sample water content test with storage variations of less than 1, 1, 2 and 3 months respectively were 5.55%, 2.86%, 3.83% and 3.54% and the solubility was 42.67%, 33, 84%, 44.51% and 34.33% for Artificial Gastrid Fluid (AGF) solvents and 31.79%, 35.08%, 43.24 and 34.52% for Water solvents. The results of the organoleptic test showed that the color of the bean extract powder sample with a storage time of ± 2 months was the most preferred by the panelists, Fresh samples had the highest average scores for taste and aroma, of the panelist samples preferred the samples that had been stored for ± 3 months


2021 ◽  
Vol 7 (1) ◽  
pp. 70-83
Author(s):  
Bahman Masoomi ◽  
◽  
Neamatollah Jaafarzadeh ◽  
Tayebeh Tabatabaie ◽  
Sahand Jorfi ◽  
...  

The study investigated the effects of pre-ozonation on the parameters such as turbidity, color, chlorophyll a and TOC on a pilot scale. The investigation results indicate that the amount of required ozone to remove TOC, color and turbidity depends on the quality of inlet water, and the efficiency of water ozonation depends on the process factors such as ozone dose, temperature, pH and ozone-water contact time. The study likewise shows that the lower amount of turbidity, TOC, temperature and higher alkaline pH of sample water boost the ozonation effect on removing the variables in question. The results also demonstrate a direct relationship between pH, ozone dosage and contact time, as well as an indirect relationship between temprerature and the removal of parameters.


2021 ◽  
Vol 8 ◽  
Author(s):  
Nico Ueberschaar ◽  
Katharina Lehmann ◽  
Stefanie Meyer ◽  
Christian Zerfass ◽  
Beate Michalzik ◽  
...  

Surface-sourced organic compounds in infiltrating waters and percolates are transformed during their belowground passage. Biotic and abiotic processes thereby lead to continuously changing chemical environments in subsurface compartments. The investigation of such transformations of organic compounds aims for tracing subsurface fluxes as well as biotic and abiotic activity. To collect samples of soil solution, different kinds of lysimeters are available, spanning simple free-draining devices that sample water based on gravimetric flow and tension lysimeters allowing for approximating natural hydraulic conditions. Protocols for untargeted analytical profiling of organic soil solution constituents are scarce. We report here a solid phase extraction followed by GC–MS analysis, utilizing two long-term sampling devices in the Hainich Critical Zone Exploratory in Thuringia, Germany. In addition, we introduce a new lysimeter constructed exclusively from inert materials that allows for obtaining samples with little background signals in GC–MS. Polyvinylchloride (PVC)-based lysimeters introduce substantial background signals from plasticizers. We show how signals from these contaminants can be lowered during data analysis using chemometric background removal. Applying multivariate statistics for data analysis, we demonstrate the ability for monitoring of several sugars, fatty acids and phenolic acids at the topsoil-subsoil boundary and even beyond, via an untargeted analytical approach. Statistical tools facilitated the detection of differences in chemical signatures at three different land use sites. Data mining methods for metabolomics led to the identification of 3-carboxyphenylalanin as marker for a pasture site. The combined approach is suitable for the collection and extraction of topsoil and subsoil solution for untargeted metabolomics under near-natural flow conditions.


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