Development

Generate RFC 9562 UUIDs — including the modern v6, v7 and v8 that most generators lack — or decode any UUID back to its version, variant and embedded timestamp.

Science & Education

u = (v + u′)/(1 + vu′/c²) for β or m/s pairs: relativistic sum, Galilean comparison, γ(u), and the u′ = c photon invariance case.

Math & Numbers

2-set and 3-set inclusion-exclusion solver: every disjoint region, the union, and the outside count, with consistency checks.

Health

Convert BUN (mg/dL) to/from urea (mmol/L). Factor 0.357 (urea molar mass 60.06, BUN counts 2 N = 28.014). Derived from Young 1987, StatPearls, KDIGO 2012. Not medical advice.

Health

Compute lung-protective VT from ARDSNet predicted body weight (PBW). Male 50+0.91×(cm−152.4); female 45.5+0.91×(cm−152.4). VT = mL/kg×PBW (4–8, default 6). Reports full range and plateau-pressure target. Derived from ARDSNet NEJM 2000, Brower 2004, StatPearls, LITFL. Not medical advice.

Health

Calculate the Urea Reduction Ratio (URR) for a single hemodialysis session: URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100. KDOQI recommends a minimum URR ≥65% and a target dose ≥70%. URR is a simple adequacy marker but is being phased out in favor of Kt/V, which also accounts for urea generation and volume contraction. Derived from the KDOQI Clinical Practice Guideline for Hemodialysis Adequacy. Valid for single hemodialysis sessions with BUN drawn pre- and immediately post-treatment; not for peritoneal dialysis. Not medical advice.

Health

Empiric starting dosing for vancomycin per the 2020 ASHP/IDSA/PIDS/SIDP consensus guideline. Loading dose: 20–25 mg/kg actual body weight (obesity cap 3000 mg). Maintenance dose: 15–20 mg/kg actual body weight every 8–12 h. Optional creatinine clearance (CrCl) input suggests an empiric dosing interval (≥90 → q8h, 50–89 → q12h, 30–49 → q18–24h, 10–29 → q24h, <10 → q24–48h). Optional measured trough is classified against the SECONDARY trough target of 15–20 mg/L. The 2020 guideline shifted the primary monitoring target to AUC₀₋₂₄/MIC = 400–600 mg·h/L (within first 24–48 h); trough-only monitoring is no longer recommended as primary. Derived from Rybak MJ et al., Am J Health-Syst Pharm 2020. Empiric start doses ONLY — individualize by AUC-guided Bayesian monitoring. Not medical advice.

Math & Numbers

Compute the required outdoor / supply ventilation rate. ASHRAE 62.1 ventilation-rate procedure: people component Vpz = Rp·P, area component Vaz = Ra·A, breathing-zone outdoor air Vbz = Vpz + Vaz, zone supply airflow Voz = Vbz / Ez. Three modes: ASHRAE 62.1 (people + area), per-person rate (P × Rp), or contaminant dilution (Q = G / (C_acc − C_sup), where G can be mg/s, mg/h, or L/s of gas and concentrations mg/m³ or ppm). Results reported in L/s, m³/h, and CFM.

Media

Mux two audio tracks into one video in copy mode.

Data Visualization

Draw a Venn diagram for 2 to 4 sets, labeling each region with its size and intersections

Text Processing

Flip text upside-down (ɥǝllo) with per-letter rotations, plus optional toggles to keep reading order and protect URLs/emails. Plain Unicode text, no font needed.

Security

Detect phishing and fraud signals in a URL by deep structural analysis — punycode/IDN homograph attacks (mixed Latin/Cyrillic), embedded credentials (user:pass@host trick), high-risk TLDs, double-encoding and control-character smuggling, subdomain brand deception, and numeric/IP host obfuscation. Static analysis only, no network. Complements the URL Validator (which does basic protocol/IP checks).