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Water hammer (WH) is a phenomenon characterized by the rapid opening or closing of valves or pumps in pipelines, resulting in a disruptive noise, intense vibrations, and potential damage to pipes, fittings, structures, and even human safety. While WH arresters are commonly employed to mitigate this issue in smaller plumbing systems, alternative solutions are required for larger applications like power plants. Researchers have proposed the utilization of pipe materials with a low modulus of elasticity in areas prone to WH events, as these materials possess the capability to absorb a significant portion of the resulting vibrations. This study focuses on investigating the influence of pressure and strain induced by the WH phenomenon. Experimental data collected from measurements using a specially designed test rig, as well as numerical and dimensionless analyses applied to the same rig, are employed to examine this effect. The experimental and numerical investigations encompass a range of flow rates and pressures. Five pipe materials, namely Galvanized steel, Copper, uPVC, PPr, and GRP, were selected for evaluation. The results indicate a deviation between the numerical and experimental results of WH frequency which can be explained from the pipeline rigidity. A Fast Fourier Transform (FFT) analysis was performed to analyze the frequency components of the pressure transients resulting from water hammer events in the different pipe materials. The results indicate that pipe materials with lower elastic modulus, such as PPr and uPVC, exhibit reduced WH effects compared to materials with higher elastic modulus, such as steel. This research highlights the importance of selecting appropriate pipe materials for pressure pipelines in order to mitigate the dangers associated with WH. The results of the FFT analysis revealed distinct frequency responses for each material, illustrating how their unique viscoelastic properties affect the transient behavior. [ABSTRACT FROM AUTHOR]

The reproductive system of snails represents essential organ that affects snail population size. Therefore, the present research was directed to evaluate the effect of two biopesticides chitosan (Ch) and emamectin benzoate (EMB) LC50 on the reproductive system of Eobania vermiculata (Muller). Land snails were treated using thin-film layer technique. Snails were dissected and organs of reproductive system were weighted and examined for any pathological changes at 24, 48 and 72 h post treatment. Moreover, steroidal hormones were determined after 72 h of treatment with either chitosan or emamectin benzoate in comparison to untreated snails. Results revealed that the penis and dart sac increased in size, while ovotestis was decreased at the 3 different periods than the same organs of untreated snails. In addition, there was swelling in the size of some organs, i.e penis and vagina. While there was stunting in the albumen gland at 72 h of treatment with Ch or EMB. However, histological examination showed damage of the ovotestis and atrophy of induced cells in the dart sac and penis. The incidents of both compounds on the level of steroidal hormones gave fluctuating results, either increasingly or decreasingly. In conclusion, data emphasize that both tested compounds caused reduction in the numerical density of the E. vermiculata reproductive system and consequently decreased their fertility, as well as reduction in its population. [ABSTRACT FROM AUTHOR]

Some pharmaceutical compounds namely valsartan, hydrocholorothiazide, erythromycin thiocynate and diclofenac potassium were studied as chemical additions for enhancing the finished C-steel surface attained. Anode potential–limiting current relationship was measured and comparing of gradually increasing pharmaceutical compound concentrations (1 × 10–4–7 × 10–4 M) and weight loss method. C‑steel dissolution behavior in presence of pharmaceutical compounds was studied under natural convection and (rotating cylinder (RCE) and rotating disc electrode (RDE) as forced convection. The rotation speed of RCE and RDE was studied. The limiting current was found to diminishes with enlarging additives concentration and increase with increasing temperature (293–313 K). Activation energies values confirm that reaction rate was diffusion controlled. Results showed that the improvement produced in electropolishing in presence of pharmaceutical compounds occurs through adsorption of their molecules above metal surface. Pharmaceutical compound adsorption obey kinetic–thermodynamic model. Retardation percentage obtained from weight loss measurement are comparable with those obtained from galvanostatic polarization measurements. The data under different conditions were controlled by dimensionless correlations Sherwood (Sh), Schmidt (Sc) and Reynolds (Re) numbers. Surface morphology study confirmed that addition of pharmaceutical compound to C-steel dissolution bath enhance surface appearance and its texture quality to great extent. [ABSTRACT FROM AUTHOR]

Deeply seated fibromatosis or desmoid tumour (DT) is a rare entity characterized by benign proliferation of fibroblasts. Although non-malignant, this tumour can be life-threatening due to its invasive property and high recurrence rate. We report a unique case of a huge recurrent abdominal DT (36 cm in diameter, 25 kg in weight) that caused pressure necrosis and sloughing of the overlying anterior abdominal wall, and produced a large fungating mass protruding outside the abdomen. Although preoperative neoadjuvant therapies were all ineffective, radical surgical removal of the tumour was successful. The procedure was followed by an excellent clinical recovery and the patient is still alive with no evidence of recurrent disease after a 6-year follow-up. We recommend surgical removal of DT regardless of its size and in particular in cases where there is no or inadequate response to neoadjuvant therapy. [ABSTRACT FROM AUTHOR]

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Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)