Low temperature district heating: An expert opinion survey

Among the available solutions for building heating and cooling, district heating (DH) and district cooling (DC) systems are considered some of the best options since they can ensure a better control of pollutant emissions and greater efficiency than individual systems. Nevertheless, improvements are needed to increase their sustainability and reliability. The so-called \u201clow temperature district heating\u201d (LTDH) concept has been introduced in recent years in an attempt i) to reduce the distribution heat losses through a temperature decrease in the DH network, ii) to favor the integration with renewable energy sources, and iii) to create the conditions required for the development of future smart energy systems. However, many concerns have been raised about its implementation in both existing and new systems. For this reason, this paper aims to identify the stakeholders\u2019 ranking of the barriers against LTDH system development and implementation over the next few years. Aiming to this, a questionnaire was designed, including an analysis of current gaps and strengths, and then submitted to more than 50 Italian and international experts in the field of DH. An in-depth analysis of the received answers was performed, focusing in particular on the Italian experts\u2019 answers. Comments and suggestions on how to promote the transition to the new LTDH approach are reported

Ophiolites from the Grammos-Arrenes area, northern Greece:geological, paleontological and geochemical data

The Grammos-Arrenes ophiolites between the Pindos Flysch to the east and the Mesohellenic basin to the west represent the northernmost outcrop of the Pindos Ophiolite belt in Greece. The analyses on key outcrops of the Sub-ophiolitic Mélange allow adding new data on the age of the oceanization and on the geochemistry of the effusive products. Basalts samples show a N-MOR affinity and are associated with late Bajocian-early Bathonian radiolarian cherts. The emplacement of the ophiolites onto the sequences of the continental margin is preceded by mass flow deposition of ophiolitic material in the basins facing the advancing ophiolitic nappe. Ophiolite-bearing debris flow deposits and slide blocks are recognized in the Lower Cretaceous deep water sediments of the Beotian Unit and in the upper portion of the Tertiary Pindos Flysch. The intercalations of ophiolitic material in the Beotian flysch before, and in the Pindos Flysch later, are interpreted as the forerunners of the Ophiolitic Nappe which, coming from the Vardar Ocean located to the east, emplaced westward onto the continental margin of Adria. The collected data allow consolidating the constraints for the timing and mechanism of ophiolite emplacement in the Pindos-Grammos area. In addition, taking in consideration the geometry of tectonic stack in the Grammos-Arrenes and the ages of the involved sedimentary deposits it is possible to reconstruct a geodynamic history comparable to the other zones studied along the Dinaric-Hellenic chain