Hypocenters　of　AE　in　coal　under　miaxial　compression　test　were　determined，AE　waveforms　and　strains　were simultaneously　detected　by　l6PZT　and4strain　gauges　attached　to　the　sample　surface．The　sample　fractured　with　fracture planes　and　audible　noises，Hypocenters　were　determined　for246events　that　occurred　during　loading・ In　the　earlier　stage　when　the　number　ofAE　events　started　to　increase，hypocenters　were　located　near　a　dilatancy　region．In　the　later　stage　when　the　coal　sample　approached　to廿1e　fracture，hypocenters　concentrated　on　the　fracture　planes，An anomalous　decrease　of　volumetric　strains　was　observed　in　a　region　near　an　AE　swaτm．Temporal　variation　of　the anomalous　strain　behavior　seems　to　be　fairly　consisted　with　the　AE　activity　in　the　swarm　region、And　the　AE　activity　near the　fracture　planes　have　a　similarity　to　one　of　the　microseismic　activities　prior　to　the　coal　burst．

A　techllique　of　Operability　Study　which　was　developed　at　ICI，U。1く、has　the　feature　of　focusing　on　the　deviations　in　a p重peline　joining　two　main　plant　ltems，but　some　di伍cu］ties　in　analysis　of　auxiliary　facilities　such　as　heating　units　or　stirrers、 This　paper　presents　an　improved　technique　of　Operability　Study　which　can　identify　hazards　and　operating　Problems　for contimous　plants　in　process　systems，The　improved　technique　is　based　on　application　of　the　input－output　relation　in　the system　engineering　to　the　main　plant　item，and　the　concept　of　the　deviations　is　defined　more　cleary　by　usiηg　the　control　and state　variables、The　technique　is　illustrated　for　a　continuous　stirred　tank　reactor　with　auxiliary　facilities.

As　swimming　pool　disinfectants　derive　chlorine，the　corrosion　of　the　pool　facilities　areconcemed、 In　this　paper，the　corrosivity　of　trichloroisocyanuric　acid（TICA）and　sodium　hypochlorite　against　steel　and　aluminum were　studied．TICA　decomposed　into　hydrochloric　acid　via　hypochlorite　acid，These　reactions　proceeded　autocatalically　and acidified　the　water，The　corrosion　of　steel　and　aluminum　were　significant　in　acidi丘ed　TICA　solutions．Precipitゴted　TICA　on alumimm　induced　severe　pitting　corrosion，In　genera1，sodium　hypochlorite　were　less　corrosive　than　TICA．Pitting corrosion　of　aluminum　was　observed　only　in　the　concentrated　sodium　hypochlorite　solutions，Time　trajectories　of　corrosion potential　with　pH　on　Pourbaix　diagram　afforded　useful　informations　on　corrosion　behaviors　of　steel　and　aluminum．