{"id":{"repo_id":"greece","oai_identifier":"oai:10442/1758"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/1758","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"ΣΧΗΜΑΤΙΣΜΟΣ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΥΔΑΤΙΚΑ ΔΙΑΛΥΜΑΤΑ","abstract":"IN THIS THESIS, WE STUDY THE PRECIPITATION OF CALCIUM SULFATE FROM AQUEOUS SOLUTIONS AT SUPERSATURATIONS SUFFICIENT FOR SPONTANEOUS PRECIPITATION AND IN THE TEMPERATURE RANGE BETWEEN 20 -80 C. AT THESE CONDITIONS, THE ONLY PHASE FORMING WAS CALCIUM SULFATE DIHYDRATE. THE INDUCTION PERIODS AND THE SUBSEQUENT RATES OF PRECIPITATION WERE FOUND TO STRONGLY DEPEND ON THE SOLUTION SUPERSATURATION AND TEMPERATURE. DECREASE OF SUPERSATURATION RESULTED IN CHANGE OF THE CRYSTAL GROWTH-MECHANISM FROM SURFACE NUCLEATION TO A STEP DISLOCATION MECHANISM. THE PRESENCE OF ORGANOPHOSPHORUS COMPOUNDS HEDP, ENTMP AND NTMP) EVEN AT VERY LOW CONCENTRATIONS (A FEW PPM) DECREASED THE RATES OF CALCIUM SULFATE DIHYDRATE PRECIPITATION IN THE ORDER (ENTMP>NTMP>>HEDP) AT CONDITIONS OF SUSTAINED SUPERSATURATION. MOREOVER, WE HAVE STUDIED THE INFLUENCE OF DIVALENT METAL-IONS (CD, MG, ZNAND SR) AT SUSTAINED SUPERSATURATION. THE EFFECT OF THESE METAL-IONS WAS LIMITED IN THE DECREASE OF SOLUTION SUPERSATURATION. FINALLY, THE PRESENCE OF CRYSTALS OF CALCIUM SULFATE DIHYDRATE FAVOURED THE FORMATION OF CALCIUM CARBONATE POLYMORPHS AT HIGH TEMPERATURES.","abstract_html":"IN THIS THESIS, WE STUDY THE PRECIPITATION OF CALCIUM SULFATE FROM AQUEOUS SOLUTIONS AT SUPERSATURATIONS SUFFICIENT FOR SPONTANEOUS PRECIPITATION AND IN THE TEMPERATURE RANGE BETWEEN 20 -80 C. AT THESE CONDITIONS, THE ONLY PHASE FORMING WAS CALCIUM SULFATE DIHYDRATE. THE INDUCTION PERIODS AND THE SUBSEQUENT RATES OF PRECIPITATION WERE FOUND TO STRONGLY DEPEND ON THE SOLUTION SUPERSATURATION AND TEMPERATURE. DECREASE OF SUPERSATURATION RESULTED IN CHANGE OF THE CRYSTAL GROWTH-MECHANISM FROM SURFACE NUCLEATION TO A STEP DISLOCATION MECHANISM. THE PRESENCE OF ORGANOPHOSPHORUS COMPOUNDS HEDP, ENTMP AND NTMP) EVEN AT VERY LOW CONCENTRATIONS (A FEW PPM) DECREASED THE RATES OF CALCIUM SULFATE DIHYDRATE PRECIPITATION IN THE ORDER (ENTMP>NTMP>>HEDP) AT CONDITIONS OF SUSTAINED SUPERSATURATION. MOREOVER, WE HAVE STUDIED THE INFLUENCE OF DIVALENT METAL-IONS (CD, MG, ZNAND SR) AT SUSTAINED SUPERSATURATION. THE EFFECT OF THESE METAL-IONS WAS LIMITED IN THE DECREASE OF SOLUTION SUPERSATURATION. FINALLY, THE PRESENCE OF CRYSTALS OF CALCIUM SULFATE DIHYDRATE FAVOURED THE FORMATION OF CALCIUM CARBONATE POLYMORPHS AT HIGH TEMPERATURES.","abstract_has_math":false,"creators":["Klepetsanis, Pavlos","Κλεπετσάνης, Παύλος"],"institution":"University of Patras","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991","date_published":"1991","updated_at":"2026-07-24T02:25:05Z","subjects":["Αναστολή","Θειϊκό ασβέστιο","ΚΑΘΑΛΑΤΩΣΗ","Καταβύθιση","Κρυστάλλωση","CALSIUM SULFATE","Crystal growth","Inhibition","Precipitation","Scale","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Χημικού Μηχανικού","Engineering and Technology","Chemical Engineering"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1758"],"render_values":[{"text":"10.12681/eadd/1758","href":"https://doi.org/10.12681/eadd/1758","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/1758","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Klepetsanis, Pavlos","Κλεπετσάνης, Παύλος"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1991"]},{"key":"dc:publisher","label":"Institution","values":["University of Patras","Πανεπιστήμιο Πατρών"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Αναστολή","Θειϊκό ασβέστιο","ΚΑΘΑΛΑΤΩΣΗ","Καταβύθιση","Κρυστάλλωση","CALSIUM SULFATE","Crystal growth","Inhibition","Precipitation","Scale","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Χημικού Μηχανικού","Engineering and Technology","Chemical Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1758","http://hdl.handle.net/10442/hedi/1758"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["IN THIS THESIS, WE STUDY THE PRECIPITATION OF CALCIUM SULFATE FROM AQUEOUS SOLUTIONS AT SUPERSATURATIONS SUFFICIENT FOR SPONTANEOUS PRECIPITATION AND IN THE TEMPERATURE RANGE BETWEEN 20 -80 C. AT THESE CONDITIONS, THE ONLY PHASE FORMING WAS CALCIUM SULFATE DIHYDRATE. THE INDUCTION PERIODS AND THE SUBSEQUENT RATES OF PRECIPITATION WERE FOUND TO STRONGLY DEPEND ON THE SOLUTION SUPERSATURATION AND TEMPERATURE. DECREASE OF SUPERSATURATION RESULTED IN CHANGE OF THE CRYSTAL GROWTH-MECHANISM FROM SURFACE NUCLEATION TO A STEP DISLOCATION MECHANISM. THE PRESENCE OF ORGANOPHOSPHORUS COMPOUNDS HEDP, ENTMP AND NTMP) EVEN AT VERY LOW CONCENTRATIONS (A FEW PPM) DECREASED THE RATES OF CALCIUM SULFATE DIHYDRATE PRECIPITATION IN THE ORDER (ENTMP>NTMP>>HEDP) AT CONDITIONS OF SUSTAINED SUPERSATURATION. MOREOVER, WE HAVE STUDIED THE INFLUENCE OF DIVALENT METAL-IONS (CD, MG, ZNAND SR) AT SUSTAINED SUPERSATURATION. THE EFFECT OF THESE METAL-IONS WAS LIMITED IN THE DECREASE OF SOLUTION SUPERSATURATION. FINALLY, THE PRESENCE OF CRYSTALS OF CALCIUM SULFATE DIHYDRATE FAVOURED THE FORMATION OF CALCIUM CARBONATE POLYMORPHS AT HIGH TEMPERATURES.","ΣΤΗΝ ΠΑΡΟΥΣΑ ΕΡΓΑΣΙΑ ΜΕΛΕΤΗΘΗΚΕ Ο ΣΧΗΜΑΤΙΣΜΟΣ ΤΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΣΥΝΘΗΚΕΣΠΟΥ ΕΥΝΝΟΕΙΤΑΙ Η ΑΥΘΟΡΜΗΤΗ ΚΑΤΑΒΥΘΙΣΗ ΤΟΥ ΚΑΙ ΣΤΗΝ ΠΕΡΙΟΧΗ ΘΕΡΜΟΚΡΑΣΙΩΝ 20-80 C. ΣΤΙΣ ΣΥΝΘΗΚΕΣ ΑΥΤΕΣ ΒΡΕΘΗΚΕ ΟΤΙ ΚΑΤΑΒΥΘΙΖΕΤΑΙ ΑΠΟΚΛΕΙΣΤΙΚΑ ΔΙΕΝΥΔΡΟ ΘΕΙΙΚΟ ΑΣΒΕΣΤΙΟ. Ο ΜΗΧΑΝΙΣΜΟΣ ΚΑΤΑΒΥΘΙΣΗΣ ΕΞΑΡΤΑΤΑΙ ΑΜΕΣΑ ΑΠΟ ΤΟΝ ΥΠΕΡΚΟΡΕΣΜΟ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ ΕΡΓΑΣΙΑΣ. ΣΕ ΥΨΗΛΟΥΣ ΥΠΕΡΚΟΡΕΣΜΟΥΣ ΟΙ ΚΡΥΣΤΑΛΛΟΙ ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΜΕ ΜΗΧΑΝΙΣΜΟ ΕΠΙΦΑΝΕΙΑΚΗΣ ΠΥΡΗΝΟΠΟΙΗΣΗΣ, ΕΝΩ ΣΕ ΧΑΜΗΛΟΥΣ ΥΠΕΡΚΟΡΕΣΜΟΥΣ ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΜΕ ΜΗΧΑΝΙΣΜΟ ΕΛΙΚΟΕΙΔΟΥΣ ΜΕΤΑΤΟΠΙΣΗΣ ΒΗΜΑΤΟΣ. Η ΠΑΡΟΥΣΙΑ ΟΡΓΑΝΟΦΩΣΦΟΡΙΚΩΝ ΕΝΩΣΕΩΝ (HEDP, ENTMP KAI NTMP) ΜΕΙΩΝΕΙ ΤΗΝ ΤΑΣΗ ΣΧΗΜΑΤΙΣΜΟΥ ΤΟΥ ΔΙΕΝΥΔΡΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΜΕ ΤΗΝ ΑΚΟΛΟΥΘΗ ΣΕΙΡΑ (ΕΝΤΜΡ>ΝΤΜΠ>>HEDP) ΣΕ ΣΥΓΚΕΝΤΡΩΣΕΙΣ ΤΗΣ ΤΑΞΗΣ ΜΕΡΙΚΩΝΡΡΜ. Η ΠΑΡΟΥΣΙΑ ΔΙΣΘΕΝΩΝ ΜΕΤΑΛΛΟΙΟΝΤΩΝ (CD, ZN, MG ΚΑΙ SR) ΕΠΗΡΕΑΖΕΙ ΤΗΝ ΚΑΤΑΒΥΘΙΣΗ ΤΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΛΟΓΩ ΜΕΙΩΣΗΣ ΤΟΥ ΥΠΕΡΚΟΡΕΣΜΟΥ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ ΕΡΓΑΣΙΑΣ. ΕΠΙΣΗΣ ΒΡΕΘΗΚΕ ΟΤΙ Η ΠΑΡΟΥΣΙΑ ΔΙΕΝΥΔΡΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΕΥΝΝΟΕΙ ΤΟΝ ΣΧΗΜΑΤΙΣΜΟ ΑΝΘΡΑΚΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΥΨΗΛΕΣ ΘΕΡΜΟΚΡΑΣΙΕΣ."]},{"key":"dc:title","label":"Title","values":["ΣΧΗΜΑΤΙΣΜΟΣ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΥΔΑΤΙΚΑ ΔΙΑΛΥΜΑΤΑ","FORMATION OF CALCIUM SULFATE IN AQUENEOUS SOLUTIONS"]}]}],"canonical_facts":{"dc:creator":["Klepetsanis, Pavlos","Κλεπετσάνης, Παύλος"],"dc:date":["1991"],"dc:description":["IN THIS THESIS, WE STUDY THE PRECIPITATION OF CALCIUM SULFATE FROM AQUEOUS SOLUTIONS AT SUPERSATURATIONS SUFFICIENT FOR SPONTANEOUS PRECIPITATION AND IN THE TEMPERATURE RANGE BETWEEN 20 -80 C. AT THESE CONDITIONS, THE ONLY PHASE FORMING WAS CALCIUM SULFATE DIHYDRATE. THE INDUCTION PERIODS AND THE SUBSEQUENT RATES OF PRECIPITATION WERE FOUND TO STRONGLY DEPEND ON THE SOLUTION SUPERSATURATION AND TEMPERATURE. DECREASE OF SUPERSATURATION RESULTED IN CHANGE OF THE CRYSTAL GROWTH-MECHANISM FROM SURFACE NUCLEATION TO A STEP DISLOCATION MECHANISM. THE PRESENCE OF ORGANOPHOSPHORUS COMPOUNDS HEDP, ENTMP AND NTMP) EVEN AT VERY LOW CONCENTRATIONS (A FEW PPM) DECREASED THE RATES OF CALCIUM SULFATE DIHYDRATE PRECIPITATION IN THE ORDER (ENTMP>NTMP>>HEDP) AT CONDITIONS OF SUSTAINED SUPERSATURATION. MOREOVER, WE HAVE STUDIED THE INFLUENCE OF DIVALENT METAL-IONS (CD, MG, ZNAND SR) AT SUSTAINED SUPERSATURATION. THE EFFECT OF THESE METAL-IONS WAS LIMITED IN THE DECREASE OF SOLUTION SUPERSATURATION. FINALLY, THE PRESENCE OF CRYSTALS OF CALCIUM SULFATE DIHYDRATE FAVOURED THE FORMATION OF CALCIUM CARBONATE POLYMORPHS AT HIGH TEMPERATURES.","ΣΤΗΝ ΠΑΡΟΥΣΑ ΕΡΓΑΣΙΑ ΜΕΛΕΤΗΘΗΚΕ Ο ΣΧΗΜΑΤΙΣΜΟΣ ΤΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΣΥΝΘΗΚΕΣΠΟΥ ΕΥΝΝΟΕΙΤΑΙ Η ΑΥΘΟΡΜΗΤΗ ΚΑΤΑΒΥΘΙΣΗ ΤΟΥ ΚΑΙ ΣΤΗΝ ΠΕΡΙΟΧΗ ΘΕΡΜΟΚΡΑΣΙΩΝ 20-80 C. ΣΤΙΣ ΣΥΝΘΗΚΕΣ ΑΥΤΕΣ ΒΡΕΘΗΚΕ ΟΤΙ ΚΑΤΑΒΥΘΙΖΕΤΑΙ ΑΠΟΚΛΕΙΣΤΙΚΑ ΔΙΕΝΥΔΡΟ ΘΕΙΙΚΟ ΑΣΒΕΣΤΙΟ. Ο ΜΗΧΑΝΙΣΜΟΣ ΚΑΤΑΒΥΘΙΣΗΣ ΕΞΑΡΤΑΤΑΙ ΑΜΕΣΑ ΑΠΟ ΤΟΝ ΥΠΕΡΚΟΡΕΣΜΟ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ ΕΡΓΑΣΙΑΣ. ΣΕ ΥΨΗΛΟΥΣ ΥΠΕΡΚΟΡΕΣΜΟΥΣ ΟΙ ΚΡΥΣΤΑΛΛΟΙ ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΜΕ ΜΗΧΑΝΙΣΜΟ ΕΠΙΦΑΝΕΙΑΚΗΣ ΠΥΡΗΝΟΠΟΙΗΣΗΣ, ΕΝΩ ΣΕ ΧΑΜΗΛΟΥΣ ΥΠΕΡΚΟΡΕΣΜΟΥΣ ΑΝΑΠΤΥΣΣΟΝΤΑΙ ΜΕ ΜΗΧΑΝΙΣΜΟ ΕΛΙΚΟΕΙΔΟΥΣ ΜΕΤΑΤΟΠΙΣΗΣ ΒΗΜΑΤΟΣ. Η ΠΑΡΟΥΣΙΑ ΟΡΓΑΝΟΦΩΣΦΟΡΙΚΩΝ ΕΝΩΣΕΩΝ (HEDP, ENTMP KAI NTMP) ΜΕΙΩΝΕΙ ΤΗΝ ΤΑΣΗ ΣΧΗΜΑΤΙΣΜΟΥ ΤΟΥ ΔΙΕΝΥΔΡΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΜΕ ΤΗΝ ΑΚΟΛΟΥΘΗ ΣΕΙΡΑ (ΕΝΤΜΡ>ΝΤΜΠ>>HEDP) ΣΕ ΣΥΓΚΕΝΤΡΩΣΕΙΣ ΤΗΣ ΤΑΞΗΣ ΜΕΡΙΚΩΝΡΡΜ. Η ΠΑΡΟΥΣΙΑ ΔΙΣΘΕΝΩΝ ΜΕΤΑΛΛΟΙΟΝΤΩΝ (CD, ZN, MG ΚΑΙ SR) ΕΠΗΡΕΑΖΕΙ ΤΗΝ ΚΑΤΑΒΥΘΙΣΗ ΤΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΛΟΓΩ ΜΕΙΩΣΗΣ ΤΟΥ ΥΠΕΡΚΟΡΕΣΜΟΥ ΤΟΥ ΔΙΑΛΥΜΑΤΟΣ ΕΡΓΑΣΙΑΣ. ΕΠΙΣΗΣ ΒΡΕΘΗΚΕ ΟΤΙ Η ΠΑΡΟΥΣΙΑ ΔΙΕΝΥΔΡΟΥ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΕΥΝΝΟΕΙ ΤΟΝ ΣΧΗΜΑΤΙΣΜΟ ΑΝΘΡΑΚΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΥΨΗΛΕΣ ΘΕΡΜΟΚΡΑΣΙΕΣ."],"dc:identifier":["10.12681/eadd/1758","http://hdl.handle.net/10442/hedi/1758"],"dc:language":["gre"],"dc:publisher":["University of Patras","Πανεπιστήμιο Πατρών"],"dc:subject":["Αναστολή","Θειϊκό ασβέστιο","ΚΑΘΑΛΑΤΩΣΗ","Καταβύθιση","Κρυστάλλωση","CALSIUM SULFATE","Crystal growth","Inhibition","Precipitation","Scale","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Χημικού Μηχανικού","Engineering and Technology","Chemical Engineering"],"dc:title":["ΣΧΗΜΑΤΙΣΜΟΣ ΘΕΙΙΚΟΥ ΑΣΒΕΣΤΙΟΥ ΣΕ ΥΔΑΤΙΚΑ ΔΙΑΛΥΜΑΤΑ","FORMATION OF CALCIUM SULFATE IN AQUENEOUS SOLUTIONS"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:25:05Z"}