dynamic conditions
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Author(s):  
Eldar P. Magomedbekov ◽  
Aleksei O. Merkushkin ◽  
Alexander V. Obruchikov ◽  
Veronika S. Pokalchuk

2022 ◽  
Vol 6 (4) ◽  
pp. 387-394
Author(s):  
D. S. Galchenko ◽  
M. G. Smirnova ◽  
L. I. Sokolova

The problem of wastewater treatment from residual antibiotics is of particular relevance, since these drugs are used in many agricultural sectors. Antibiotics get into water, animal and human bodies, where they can accumulate negatively affecting health. The aim of this article is to study the possibility of using natural aluminosilicate vermiculite sorbent from the Koksharovskoye field (Primorsky Region) for purifying fish processing and fish farming enterprises’ waste water from antibiotics (chloramphenicol, tetracycline, cefazolin, cefuroxime, ceftriaxone, cefepime and and ciprofloxacin) under static and dynamic conditions. The study was carried out on a model wastewater system with injected antibiotics. The purification ability of the model system using the method of spectrophotometric antibiotics detection is analyzed. Under static conditions, the total content of antibiotics varied from 0.25 mg to 1.00 mg per 1 g of sorbent. Under dynamic conditions, the antibiotic content was 0.025 mg per 1 g of sorbent. High values of absorption for all studied antibiotics, except for chloramphenicol, were achieved both in static and dynamic modes. For chloramphenicol, when examined under static conditions, the maximum absorption rate was 45% with the minimum total concentration of antibiotics. With an increase in the load on the sorbent, the degree of absorption decreased to 3%. Thus, vermiculite modified with 7% hydrochloric acid is a promising sorbent for cleaning water bodies from residual antibiotics.


Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 365
Author(s):  
Anna Švančárková ◽  
Dagmar Galusková ◽  
Aleksandra Ewa Nowicka ◽  
Helena Pálková ◽  
Dušan Galusek

The influence of 4% acetic acid (pH~2.4) and an alkaline solution of NaOH (pH~10) on the corrosion resistance and micromechanical properties of disilicate crystals containing glass-ceramics (LS2-GC’s) is studied. Partially crystallized lithium metasilicate crystal containing glass-ceramics (LS-GC’s) are annealed to fully LS2-GC’s using a one stage and a two-stage heating to induce nucleation. Materials with various chemical and wear resistance are prepared. The content of the crystalline phase in the material annealed in the two-stage process A is 60.0% and increases to 72.2% for the material heated in the one-stage process B. The main elements leached in the acidic medium are lithium and phosphorus, while lithium, silicon, and phosphorus leached into the alkaline environment. Material B exhibits better chemical resistance to the corrosive influence of 4% acetic acid under quasi-dynamic conditions. In the alkaline corrosion medium, silicon is leached from material A faster compared to the material B. After prolonged exposure to acidic or basic environments, both materials show evidence of surface structural changes. A decrease of the sliding wear resistance is observed after corrosion in the acidic environment under dynamic conditions. In both materials, the wear rate increases after corrosion.


Author(s):  
Ari Nurhayati ◽  

The Covid-19 outbreak has affected changes in various sectors of life. With this change, of course, every organization needs new strategies, scenarios and leadership and management patterns to overcome all the uncertainties that occur in the Covid-19 pandemic. Government agencies are required to adapt according to dynamic conditions, and must be sensitive to the dynamics of changes that occur including how the implementation of work from home is carried out. For this reason, this research was carried out with the aim to find out how the implementation of work from home of the Indonesian Migrant Workers Protection Agency (BP2MI) institution in the second year of the Covid-19 pandemic. The research approach used in this research is qualitative methods. The data was obtained through interviews, observations and documentation.


2021 ◽  
Author(s):  
Itzia S. Gómez-Alonso ◽  
Ilse D. Estrada-Alemán ◽  
Sergio Martínez-García ◽  
Humberto Peralta ◽  
Erika T. Quintana ◽  
...  

Abstract The Staphylococcus aureus’ SdrG protein is glycosylated by SdgA and SdgB for their protection against its degradation by the neutrophil’s cathepsin G. So far, there is not information about the role of Staphylococcus epidermidis’ SdgA nor SdgB in the production of biofilm, therefore the main of this work was to determine the distribution and expression of sdrG, sdgA and sdgB genes in S. epidermidis in conditions of biofilm. The frequency of the genes sdrG, sdgA and sdgB were evaluated by PCR in a collection of 75 isolates. The isolates were grown in dynamic conditions (in agitation) or static conditions (biofilm productor: planktonic or sessile cells). The expression of sdrG, sdgA and sdgB were determined by RT-qPCR in cells grown under dynamic conditions (CGDC), as well as planktonic and sessile cells, and in cells adhered to a catheter (in vivo). The genes sdrG and sdgB were detected in 100% of isolates, meanwhile the gene sdgA was detected in 71% of the samples (p<0.001). The CGDC did not expressed the sdrG, sdgA and sdgB mRNAs. The planktonic and sessile cells expressed sdrG and sdgB, and the same was seen in cells adhered to the catheter. In particular, one isolate, able to induce biofilm under cathepsin G treatment, expressed sdrG and sdgB in planktonic, sessile and in cells adhered to the catheter. This suggests that the state of cells adherence is an important factor for the transcription of sdgA, sdgB and sdrG.


2021 ◽  
Author(s):  
Hashem Obaid ◽  
Scott Ashby ◽  
Mohamed El Sheshtawy ◽  
Niyaz Ikhsanov

Abstract Maintaining annuli integrity is critical for safe and optimized well operations. Monitoring of tubing casing annulus (TCA) and casing-casing annulus (CCA) pressures is mandatory as it gives a direct indication of possible seal or tubular failures that may lead to a negative impact on HSE or well production. In cases where the observed annuli pressures suggest leaks and possible communication between tubing and TCA or TCA and CCA, a comprehensive plan should be put in place to detect and evaluate the possible leak sources and paths that will allow for proper remedial actions. Logging techniques using spectral noise logging (SNL), and high precision temperature Logging (HPT) are one way to diagnose the source of a leak and communication path between 2 adjacent casings (for example TCA and CCA). The operation is performed by running the HPT and SNL log under shut in conditions to establish a base line, followed by logging under dynamic conditions. Dynamic conditions can include bleeding off the TCA pressure while all other annuli and tree valves are shut-in and injecting into the tubing-casing annulus while bleeding off the CCA. The dynamic passes aim to activate the leak points. The SNL and HPT will capture the corresponding temperature and Spectral noise events revealed by the fluid flow though the leak points. These are compared to the base line shut in logs. The SNL is run in stations and can capture noise generated by fluid movement in a wide range of strength (decibels) and frequency within a wide scanning radius, while HPT can capture minor temperature changes of 0.02 Deg F. The paper will discuss an example where the HPT and SNL were run along with a set of conventional sensors such as GR, CCL, and pressure in a HPHT gas well to diagnose leak points and a possible communication path between the TCA and CCA. The Logging operation was carried out rig-less with minimum intervention using wire line under the shut in and dynamic conditions. Spectral noise logging precisely captured the leak points and drew a clear picture of the casing integrity breaches in multiple points. The results of the diagnostics and evaluation will now be used to design the appropriate remedial actions required to restore the well to the desired condition for production.


2021 ◽  
pp. 117074
Author(s):  
Marv J. Khala ◽  
Colin Hare ◽  
Chuan-Yu Wu ◽  
Navin Venugopal ◽  
Martin J. Murtagh ◽  
...  

2021 ◽  
Vol 12 ◽  
pp. 1-6
Author(s):  
Yale A. Fillingham ◽  
John P. Matonick ◽  
Vivienne Mendoza ◽  
Javad Parvizi

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