screw dislocationscrew linescrew threadscribersdidusseaf of idealssealsealing ringseamseamingseamlesssearchsearchlightseasonalseasonal demandseasonal effectsecsecantsecant figuresecant functionsecant linesecant methodsechsecondsecond best optimizationsecond boundary value problemsecond coordinatesecond curvaturesecond degreesecond degree cruvesecond degree equationsecond derivativesecond derivative testsecond diagonalsecond dualsecond fundamental form of a hypersufacesecond fundamental form of a hypersurfacesecond isomorphism theoremsecond kindsecond law of cosinessecond mean value theoremsecond number classsecond of a finite groupsecond of a polyhedral anglesecond ordersecond order derivativesecond order derivativessecond order differentialsecond order differential equationsecond order equation