Numerical Study on Roadway Stability under Weak Geological Condition of PT Gerbang Daya Mandiri Underground Coal Mine in Indonesia

This paper aims to assess the roadway stability of the PT Gerbang Daya Mandiri (GDM) underground coal mine. A numerical analysis method using 3D finite difference code (FLAC 3D) was used to investigate the failure zone behavior of the roadway at various overburden depths (50 m, 100 m, 200 m, and 300 m). The outcome of this research was the most appropriate support system of the roadway. The results of numerical analyses indicated that the excavation depth affected the thickness of failure zone, and the capacity of the support system was significantly associated with an increase of the overburden depth. Steel set, cablebolt, and rockbolt supports were assessed in this paper. The steel set is selected as the main support system in GDM coal mine, and it is effective to stabilize the roof and sidewalls of the roadway until 200 m depth. As the failure zone becomes larger at the deeper sites, the cablebolt support is introduced to control the floor stability, and the use of rockbolt in combination with steel set is suggested to support the roof and sidewalls

Comparison of the Whole-Genome Sequence of the African Swine Fever Virus from a Mongolian Wild Boar with Genotype II Viruses from Asia and Europe

African swine fever (ASF) is a highly contagious and severe viral hemorrhagic disease in domestic and wild pigs. ASF seriously affects the global swine industry as the mortality rate can reach 100% with highly virulent strains. In 2007, ASF was introduced into the Caucasus and spread to Russia and later into other European and Asian countries. This study reported the first whole-genome sequence (WGS) of the ASF virus (ASFV) that was detected in a Mongolian wild boar. This sequence was then compared to other WGS samples from Asia and Europe. Results show that the ASFV Genotype II from Mongolia is similar to the Asian Genotype II WGS. However, there were three nucleotide differences found between the Asian and European genome sequences, two of which were non-synonymous. It was also observed that the European Genotype II ASFV WGS was more diverse than that of the Asian counterparts. The study demonstrates that the ASFV Genotype II variants found in wild boars and domestic pigs are highly similar, suggesting these animals might have had direct or indirect contact, potentially through outdoor animal breeding. In conclusion, this study provides a WGS and mutation spectrum of the ASFV Genotype II WGS in Asia and Europe and thus provides important insights into the origin and spread of ASFV in Mongolia