Low-temperature embrittlement of Ti-6Al-4V and Inconel-718 by high pressure hydrogen

Notched specimens of titanium alloy and Inconel-718 exhibit little reduction of notch strength at certain low temperatures under 2000 lb/sq in. hydrogen, unnotched specimens are not embrittled at these temperatures. The degree of Inconel-718 embrittlement is lower than earlier observations under 1000 lb/sq in. hydrogen

Conservation of amphibians and reptiles in Indonesia: issues and problems

Indonesia is an archipelagic nation comprising some 17,000 islands of varying sizes and geological origins, as well as marked differences in composition of their floras and faunas. Indonesia is considered one of the megadiversity centers, both in terms of species numbers as well as endemism. According to the Biodiversity Action Plan for Indonesia, 16% of all amphibian and reptile species occur in Indonesia, a total of over 1,100 species. New research activities, launched in the last few years, indicate that these figures may be significantly higher than generally assumed. Indonesia is suspected to host the worldwide highest numbers of amphibian and reptile species. Herpetological research in Indonesia, however, has not progressed at a rate comparable to that of neighboring countries. As a result, the ratio of Indonesian species to the entirety of Southeast Asian and Malesian species has “declined” from about 60% in 1930 to about 50% in 2000, essentially a result of more taxa having been described from areas outside Indonesia. Many of these taxa were subsequently also found in Indonesia. In the last 70 years, 762 new taxa have been described from the Southeast Asia region of which only 262 were from Indonesia. In general, the herpetofauna of Indonesia is poorly understood compared to the herpetofauna of neighboring countries. This refers not only to the taxonomic status, but also to the basic biological and ecological characteristics of most of the species. Moreover, geographic distribution patterns for many species are only poorly known. In view of the alarming rate of forest loss, measures for more effective protection of the herpetofauna of Indonesia are urgently required. The status of virtually all of the Indonesian species, e.g. in terms of IUCN categories, remains unknown, and no action plans have been formulated to date. In addition, research results on Indonesia’s amphibian and reptile fauna have often not been made available in the country itself. Finally, there is a clear need to organize research activities in such a way that a larger segment of the Indonesian population becomes aware of the importance of the herpetofauna as an essential component of the country’s biodiversity. To address these issues, this paper (1) gives an overview of the herpetofauna as part of Indonesia’s biodiversity, (2) outlines the history of herpetological research in the region, (3) identifies major gaps in our knowledge of the Indonesian herpetofauna, and (4) uses this framework for discussing issues and problems of the conservation of amphibians and reptiles in Indonesia. In particular, the contents and shortcomings of compilations of lists of protected or threatened species by national and international authorities are discussed, major threats to the Indonesian herpetofauna or certain components thereof are described, and a set of measures for better longterm conservation is proposed.Abstrak.—Indonesia adalah suatu negara kepulauan yang terdiri dari sekitar 17.000 pulau dengan ukuran bervariasi dan mempunyai asal usul geologi yang kompleks seperti yang terlihat dalam komposisi tumbuhan dan hewannya. Indonesia, sebagai salah satu pusat keanekaragaman yang terbesar di dunia, baik dari segikekayaan alam jenisnya maupun dari segi tingkat endemisitasnya. Menurut Biodiversity Action Plan for Indonesia, 16% dari amfibi dan reptil dunia terdapat di sini, dengan jumlah lebih dari 1100 jenis. Kegiatan penelitian yang dilaksanakan pada masa yang baru lalu menunjukkan bahwa jumlah tersebut di atas masih jauh di bawah keadaan yang sebenarnya. Indonesia mungkin sekali sebuah negara yang mempunyai jumlah amfibi dan reptil terbesar di dunia. Yang patut menjadi pertimbangan ialah bahwa penelitian amfibi dan reptil di Indonesia jauh lebih lambat di bandingkan dengan kemajuan di negara tetangga. Sebagai gambaran, jumlah jenis di Indonesia apabila dibandingkan dengan jumlah jenis di seluruh Asia Tenggara dalam kurun waktu 70 tahun telah merosot dari 60% menjadi 50%. Hal ini terjadi karena jumlah taksa baru kebanyakan ditemukan di luar Indonesia. Banyak diantara jenis-jenis tersebut kemudian ditemukan di Indonesia. Dalam 70 tahun terakhir, 762 jenis taksa dipertelakan dari luar Indonesia dan hanya 262 pertelaan dari Indonesia. Pada umumnya herpetofauna Indonesia tidak banyak dikenal, baik dari segi taksonomi, ciri-ciri biologi maupun ciri-ciri ekologinya. Daerah penyebaran suatu jenis sangat sedikit diketahui. Meninjau dari cepatnya penebangan dan pengalihan fungsi hutan, usaha untuk melindungi komponen biologi (dalam hal ini amfibi dan reptil) sangat diperlukan. Hampir semua status perlindungan baik secara nasional maupun dengan mengikuti kategori IUCN atau CITES tidak banyak diketahui atau dipahami. Kebanyakan informasi mengenai organisme Indonesia sulit diperoleh di dalam eri. Sebagai akibat, maka diperlukan suatu mekanisme untuk mengatur kegiatan penelitian sedemikian rupa sehingga timbul kesadaran bahwa amfibi dan reptil merupakan salah satu komponen yang sangat berharga dari kekayaan keaneka-ragaman Indonesia. Makalah ini memberikan (1) gambaran komponen biodiversitas herpetofauna Indonesia, (2) memaparkan sejarah perkembangan herpetologi di Indonesia, (3) mengidentifikasi kekosongan dalam pengetahuan herpetologi di Indonesia, (4) memaparkan masalah dan jalan keluar dalam konseravsi keanekaragaman herpetofauna Indonesia. Daftar herpetofauna Indonesia yang dilindungi undang-undang, CITES dan IUCN dibahas, hewanhewan yang mulai terancam dan kiat untuk melindunginya dibahas

Influence of gaseous hydrogen on metals

Tensile, fracture toughness, threshold stress intensity for sustained-load crack growth, and cyclic and sustained load crack growth rate measurements were performed on a number of alloys in high-pressure hydrogen and helium environments. The results of tensile tests performed in 34.5 MN/m2 (5000 psi) hydrogen indicated that Inconel 625 was considerable embrittled at ambient temperature but was not embrittled at 144 K (-200 F). The tensile properties of AISI 321 stainless steel were slightly reduced at ambient temperature and 144 K (-200 F). The tensile properties of Ti-5Al-2.5 Sn ELI were essentially unaffected by hydrogen at 144 K (-200 F). OFHC copper was not embrittled by hydrogen at ambient temperature or at 144 K (-200 F)

Results of electroencephalographic examina- tions under the influence of vibration and centrifuging in the monkey

Electroencephalographic examinations of monkeys under influence of vibrations and centrifugin

Analysis of baseline and Gemini flight GT-7 EEG data with specification of on-line computing requirements

Analysis of baseline and Gemini GT-7 ELECTROENCEPHALOGRAM data with specification of on-line computing requirement

Influence of gaseous hydrogen on metals Interim report

Gaseous hydrogen embrittlement in Inconel 718, Inconel 625, AISI 321 stainless steel, Ti-5Al-25Sn ELI, and OFHC coppe