Can Surface Coating of Circular Saw Blades Potentially Reduce Dust Formation?

Coating of steel is a frequently applied approach to increase the resistance of moving machine parts towards abrasion, surface oxidation, and corrosion. Here, we show that plating circular saw blades with certain metals can help to reduce the electrical charging of wood dust during cutting, which has significant implications for occupational safety, healthcare, and lifetime of filter systems. With the example of beech wood planks, machine net energy consumption EV (J cm-3) and cumulated field strength E→V (kV m-4) as caused by electrically charged particles were compared for cutting of 10- and 20-mm deep grooves (800 mm length) using saw blades of different toothing (24, 60 teeth) and surface coating (Cu, Ag, and Cr). To ensure uniform feed per tooth (fz = 0.063 mm), saw blades were operated at different rotation speeds (4000 vs. 1600 rpm). The results demonstrate that the extent of electrostatic sawdust charging can be manipulated to a certain extent by the type of saw blade plating. Coating with chromium turned out to be most effective in shifting the electrostatic charge of the wood particles towards neutralization. Lowering of rotation speed using circular saw blades of higher toothing was an additional measure significantly reducing electrostatic charging of wood dust. Hence, cutting with a chrome-coated blade with 60 teeth can be specifically recommended as the reduction of electrical saw dust charging is not associated with higher machine power consumption.

Uterus didelphys with unilateral distal vaginal agenesis and ipsilateral renal agenesis: common presentation of an unusual variation.

Mullerian duct abnormalities are congenital malformations that are easily missed and can lead to incorrect diagnosis and unnecessary operative procedures. In this case, a young female presented with cyclic pelvic pain that continued after previous surgical resection of an ovarian cyst. Further investigation with clinical examinations and multimodality imaging demonstrated ipsilateral renal agenesis and a Class III Mullerian duct anomaly (MDA) requiring a second operative procedure. It is believed that this case is a variant of the described obstructed hemi-vagina with ipsilateral renal agenesis (OVIRA) anomaly as pathologically there was ipsilateral renal agenesis and complete vaginal agenesis in our case. It is imperative to have a high clinical suspicion of mullerian duct abnormalities when encountering a patient with other urogenital anomalies. This will decrease the amount of misdiagnoses, guide appropriate surgical intervention, and decrease the risk of future reproductive complications.