Effects of Hyperthermia on the Mouse Testis and Its Response to X-rays, as Assayed by Weight Loss

Background Numerous studies on involuntary weight loss (IWL) have been published since the 1980s, although most of them have included small samples of patients with specific symptoms. The aim of the present study was to determine the causes, demographic and clinical characteristics and mortality at 12 months in patients attended at a rapid diagnostic unit (RDU) for isolated IWL. Methods A single-center retrospective observational study including all patients presenting to the RDU for isolated IWL between 2005 and 2013. The following data were recorded: demographic and clinical variables, results of complementary tests (blood tests, x-rays, computed tomography scan and digestive endoscopy), main diagnosis and vital status at 12 months. Results Seven hundred and ninety-one patients met the criteria for IWL. Mean age was 67.9 years (SD 4.7), 50.4% were male and mean weight loss was 8.3 kg (SD 4.7). The cause for IWL was malignant disease in 23.6% of patients, non-malignant organic disease in 44.5%, psychiatric disorder in 29.0% and unknown in 3.2%. Overall mortality at 12 months was 18.6% (95%CI: 16.1–21.6). The mortality rate was highest in the group with malignancy (61.1%; 95%CI: 54.2–68.2). Conclusions Almost a quarter of all patients attended at the RDU for IWL were diagnosed with cancer. Mortality at 12 months was higher in this group than in the other three. Malignancy should therefore be ruled out during the first visit for patients attended for IWL.

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Pyrolysis and Combustion Kinetics of Disposable Surgical Face Mask Produced During Covid-19 Pandemic

10.21203/rs.3.rs-695931/v1 ◽

2021 ◽

Author(s):

Arshad Adam Salema ◽

Yasmin Mohd Zaifullizan ◽

Wong Wai Hong

Keyword(s):

Weight Loss ◽

Face Mask ◽

Chemical Processes ◽

X Rays ◽

Combustion Kinetics ◽

Heating Rates ◽

Safe Disposal ◽

Model Free ◽

The Face ◽

Kinetics Of

Abstract In order to prevent the spread of Covid 19, most countries have made face masks compulsory. Millions of face mask are disposed of daily in the community. Therefore, the aim of the present paper is to study the thermo-chemical (pyrolysis and combustion) behavior of the face mask for its safe disposal. The kinetic parameter activation energy was calculated using both the model-based Coats–Redfern method and model-free methods (Flynn-Wall-Ozawa, Kissinger-Akihara-Sunose, and Starink) at four different heating rates (5, 10, 15, and 20 °C/min). Physical morphology with elemental analysis was performed using field-emission scanning electron microscopy and energy-dispersive X-rays. Results have shown that face masks decompose in the temperature range of 320–480 °C during pyrolysis with a maximum derivative weight loss of 2.5 %/°C. Combustion took place between 200 and 370 °C with a maximum derivative weight loss of 1.25 %/°C. The average activation energies calculated using model-free methods for pyrolysis and combustion were ~135 kJ/mol and ~65 kJ/mol, respectively. The leftover residue for both pyrolysis and combustion was in the range of 1.35 to 3.50 wt.%. In conclusion, thermo-chemical processes are a promising method for the safe disposal of face mask waste.

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Comparative study on the corrosion behavior of mild steel in effluents, sea and fresh water

Bayero Journal of Pure and Applied Sciences ◽

10.4314/bajopas.v12i1.43s ◽

2020 ◽

Vol 12 (1) ◽

pp. 280-284

Author(s):

Naja’atu Auwal Usman ◽

Usman Muhammad Tukur ◽

Bishir Usman

Keyword(s):

Weight Loss ◽

Corrosion Rate ◽

Mild Steel ◽

Water Sample ◽

Fresh Water ◽

Immersion Time ◽

Sea Water ◽

Oxygen Demand ◽

Chloride Ion ◽

X Rays

The corrosion rate of mild steel behavior exposed to effluents (EF), sea water (SW) and fresh water (FW) were study using weight loss, scanning electron spectroscopy (SEM) and x-rays diffraction (XRD). The results show that the weight loss of mild steel in different water samples increases with increasing in immersion time and temperature respectively. The corrosion rate of water was found to be higher in sea water (0.003g cm2 week-2), effluents (0.021g cm-2 week-2) and fresh water (0.020g cm-2 week-2) respectively. The corrosion rate and behaviour of mild steel in the water sample were affected by some physical and chemical parameters such as pH, turbidity, conductivity and biological oxygen demand (BOD). Effluents (EF) were found to have pH (5.20), turbidity (13.3nut), conductivity (4203µs/cm) and BOD (0.119mg/dm3). Sea water (SW) were found to have pH (7.60), turbidity (173nut), conductivity (30800µs/cm) and BOD (0.028mg/dm3). Fresh water (FW) were found to have pH (7.60), turbidity (127nut), conductivity (419µs/cm) and BOD (0.651mg/dm3). Similarly, the presences of elements such as chloride ion (Cl-), Fe, Ba, Br, S, La, Nb and Mo from XRF confirm that the corrosion rate is higher in sea water. SEM microgram revealed that corrosion rates of EF, SW and FW were of different nature, both the samples have rough surface with various cracks after immersion. This clearly shows that the sea water has the highest corrosion products follow by effluent than fresh water sample. Both the weight loss and corrosion rate increases as the immersion time and temperature increases. Keywords: Corrosion rate, Mild steel, Weight loss, AAS, SEM, XRF, Immersion Time, Temperature

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