DEVELOPMENT OF EFFICIENT WASHING TECHNOLOGY OF PARTS, MEETING SAFETY REQUIREMENTS DUE TO THE APPLICATION OF WATER-BASED WASHING SOLUTIONS

In the manufacture of parts, surfaces are contaminated due to the peculiarities of the technology. Safe cleaning of these surfaces is an urgent problem. The article discusses non-refractory solutions for cleaning parts. The methodology for carrying out research on cleaning pollution is presented. The following contaminants were chosen: preservation oil K-17, Mobil 423 oil, SOZh-073, Vacuquench B244 quenching oil, Polishing paste, MPK emulsion. The quality of cleaning the contaminants was tested for the following detergents: Ardrox 6378 A, Ardrox 6333, Ardrox 6486. Detergent Ardrox 6378A washes away all investigated contaminants from the surface of the samples, except for conservation oil. Ardrox 6333 B detergent does not wash stubborn contaminants – K-17 conservation oil and polishing paste. The Ardrox 6486 detergent composition does not wash all investigated contaminants except the IPC emulsion. Of the Ardrox brand detergents, Ardrox 6378A is the most effective. Studies have been conducted to determine the optimal contaminant cleaning regime for the most effective detergent composition – Ardrox 6378A. The study showed that at a concentration of this composition of 15 % and a temperature of 65 °C, the surface is washed from all contaminants.

DESKRIPSI KUALITAS DAN KUANTITAS LIMBAH CAIR USAHA LAUNDRY DI KELURAHAN SUMAMPIR KECAMATAN PURWOKERTO UTARA KABUPATEN BANYUMAS TAHUN 2018

Background The development of laundry business in the increasingly rapid in Sumampir village make the aquatic environment in the region to be foamy and overgrown with microalgae. Research purposes to describe and to know the quality and quantity of waste water of laundry in Sumampir Village. Type of research, descriptive research. The subjects 9 laundry business, parameters measured are phosphate content of waste water, detergent type, detergent composition, detergent dosage, volume of waste water, frequency of waste water disposal and waste water management from laundry business.The results 89% of laundry business with average phospate 0,76 mg/L (content appropriate) and 11% laundry business with phosphate level of 5.84 mg/L (did not appropriate), 67% of the laundry business used liquid detergent, soft and matic top load type and 33% of respondents used powder detergent, hard and matic front load, 44% of respondents did not use detergents according to the type of washing machine. Detergent composition used by laundry business that is 25% Total Surfactant, Antibacterial Agent, Sodium Alkyl Benzene Sulfonate and Natrium Carbonate 20%. The majority of the detergent dosage used by the laundry business is 23 ml. The average volume of waste water produced from 9 laundry business 1038.57 liters/day. Average frequency of waste water disposal from 9 laundry business 13 times/day and 100% laundry business does not manage the waste water and does not have a waste water treatment facilities. Conclusion, the quality and quantity of wastewater at laundry business in Sumampir Village is at risk of environmental pollution

Mechanical coupling of the multiple structural elements of the large-conductance mechanosensitive channel during expansion

The prokaryotic mechanosensitive channel of large conductance (MscL) is a pressure-relief valve protecting the cell from lysing during acute osmotic downshock. When the membrane is stretched, MscL responds to the increase of membrane tension and opens a nonselective pore to about 30 Å wide, exhibiting a large unitary conductance of ∼3 nS. A fundamental step toward understanding the gating mechanism of MscL is to decipher the molecular details of the conformational changes accompanying channel opening. By applying fusion-protein strategy and controlling detergent composition, we have solved the structures of an archaeal MscL homolog from Methanosarcina acetivorans trapped in the closed and expanded intermediate states. The comparative analysis of these two new structures reveals significant conformational rearrangements in the different domains of MscL. The large changes observed in the tilt angles of the two transmembrane helices (TM1 and TM2) fit well with the helix-pivoting model derived from the earlier geometric analyses based on the previous structures. Meanwhile, the periplasmic loop region transforms from a folded structure, containing an ω-shaped loop and a short β-hairpin, to an extended and partly disordered conformation during channel expansion. Moreover, a significant rotating and sliding of the N-terminal helix (N-helix) is coupled to the tilting movements of TM1 and TM2. The dynamic relationships between the N-helix and TM1/TM2 suggest that the N-helix serves as a membrane-anchored stopper that limits the tilts of TM1 and TM2 in the gating process. These results provide direct mechanistic insights into the highly coordinated movement of the different domains of the MscL channel when it expands.

Modified Lignin as an Environmentally Friendly Surfactant

The effect of softwood sulphate lignin modified by its oxidation in alkaline medium on its behaviour at the air-water and oil-water interface, where rapeseed oil and technical fish fat oil served as the oil phase, was investigated. It has been found that, irrespective of the рН values of the water solution, the ability of the modified lignin to be adsorbed at the interfaces exceeds that of unmodified lignin, which is obviously caused by the pronounced differentiation of the hydrophilic and hydrophobic parts of the molecular structure in the oxidised lignin and the decrease in the content of the high-molecular fraction (Mw is greater than 1000) in it. At low concentrations (≤ 0.01 g/dl), the stabilising action of the modified lignin in the rapeseed oil-water emulsion is the same as that of sodium dodecyl sulphate. The enhanced surface activity of the oxidised sulphate lignin enables it not only to substitute the 30% of the mass of the commercial surfactant in the detergent composition for washing stainless steel plates, used during fish smoking, but also to upgrade its properties.