简介：Handlingindustrialpowdersleadstodustemissions.Theseemissionstendtogeneratehumandiseasesorcauseotherenvironmentaleffects.Amultitudeofapparatushasbeendevelopedtoestimatethisdustinessbehaviourofpowders.Twoofthesewell-knownmethodsarepresentedandcomparedwitheachother.Athirdrecentlydevelopedmethodisalsointroduced.

简介：ThestabilitydegreeofperiodicsolutionofnonlinearnonautonomoussystemwasdefinedbymeansoftheFloquettheory.Amethodevaluatingthestabilitydegreeofperiodicsolutionbasedontransientresponsewaspresentedbytheaidoftheconceptofdynamicsystemsorflows.Thecriticalvalueofasystemwasdeterminedbythecondition,i.e.,itsstabilitydegreeequalszero.Stableregionsofrotorsystemswithbalancedandunbalanceddisksupportedonlubricatedbearingswerecalculated.Thestudyshowsthatstableregiondecreaseswiththeincreaseofspeedforabalancedrotorsystemanddecreaseswiththeincreaseofunbalanceforanunbalancedrotorsystem.Stableregionsofperiodicsolutionsarelessthanthatofequilibriumpointsunderthesamesystematicconditions.

简介：Anapproximatemethodfordescribingtheplastichardening-softeningbehaviourofcircularpipessubjectedtopurebendingispresented.Theo-reticalestimationbasedontheuniformovalizationmodelandlocalcollapsemodelproposedinthepaperisincorporatedtogiveseveralsimpleformulationswithrea-sonableaccuracyfordeterminingtherelationshipbetweenbendingmoment(M)andcurvature(k)inthepurelybendedpipes.Attentionisfocusedonthecriticalcur-vatureassociatedwithmaximumresistantmomentandthemaximumchangeintheoriginaldiameterbeforetheendofuniformovalizationstageaswellasthelocalcollapsebehaviour.Somecomparisonsbetweenanalyticalresultsandexperimentalresultsaremadeinordertoexaminethetheory.