In the new normal education era, distance learning or face-to-face learning has psychological implications for students, including mathematics. This study, therefore, aims to find a conceptual model for implementing mathematics curriculum management in distance learning in Muhammadiyah private junior high schools in Yogyakarta City. This qualitative research used a descriptive approach, with data from ten Muhammadiyah private junior high schools in Yogyakarta City. The study results revealed that (1) the strategy for implementing mathematics curriculum management in distance learning was led directly by the principal in the form of a breakdown of regulations. (2) The learning carried out by the teachers was based on the plan they prepared at the beginning of the school year. (3) The success factor of the implementation carried out by the teachers was the selection of media and learning platforms. The teachers performed (4) Assessment in implementation at the end of each lesson. ( 5) The infrastructure for the learning implementation had been fulfilled. (6) The training provided to teachers had been programmed by the principal periodically. (7) Class formation was conducted to group students according to their interests and abilities. (8) The obstacle faced by the teachers was challenging to know the students' expressions during learning. Meanwhile, (9) constraints faced by students were networks and internet quotas owned, so it was not easy to understand the material presented by the teachers.

The presence of heavy metals in waters can be sourced from mining, household, agricultural waste and industrial wastes. Some heavy metals are toxic such as Cu, Hg, and Pb can accumulate in aquatic sediments. Sediments that are contaminated with heavy metals will endanger the organisms that live in them. This research aims to identify the concentrations of heavy metals Cu, Hg, and Pb in sediments in the Batang Ayumi River. This research uses a descriptive exploratory method by conducting a survey in advance. Determination of sampling locations using purposive sampling method at four determined stations. This research uses an Atomic Absorption Spectrophotometer. Data analysis was performed by comparing the test result data with the quality standards issued by the IADC / CEDA. The test results show that the concentration of Cu, Hg and Pb in the sediment has a value smaller than the target level value, so the substance in the sediment is not too dangerous for the environment.