Vacuum chamber is remotely sealed by eutectic metal

Vacuum chamber is remotely sealed by a design using metal seal blades which are inserted into a molten eutectic metal by pressurizing an expansion bellows. The process increases allowable manipulations by improving working space and safety factors

X-ray Variability and Period Determinations in the Eclipsing Polar DP Leo

An analysis of ROSAT observations for the eclipsing magnetic cataclysmic binary DP Leo provides constraints on the origin, size, temperature, variability and structure of the soft X-ray emission region on the surface of the white dwarf. These data, when combined with prior observations, show a progression of approximately 2 degrees per year in the impact position of the accretion stream onto the white dwarf. One explanation for the observed drift in stream position is that a magnetic activity cycle on the secondary produces orbital period oscillations. These oscillations result in an orbital period which cycles above and below the rotational period of the nearly synchronous white dwarf. The accretion stream and X-ray emission regions are modeled to fit the observational data. A distance to the system is also calculated. [An erroneous value for the cyclotron luminosity, included in an earlier paper version of the preprint, is corrected here.]Comment: uuencoded PostScript file (25 pages) + 8 figures available by anonymous ftp to ftp.astro.psu.edu (in the directory /pub/robinson), to appear in ApJ, PSU preprint 1994-1

More Bang for your Buck: Bolstering Learning Via Refutation Text with Refutation-based Elaborated Feedback

The current study examines the effects of refutation text and refutation-based elaborated feedback on conceptual understanding, self-efficacy, interest, beliefs, attitudes, and knowledge, within the context of learning about climate change. The study also tests whether elaborated feedback moderates the refutation text effect through an interaction. One hundred and fifty nine undergraduate students were recruited to participate in this study, which was administered via computer. They completed measures of their self-efficacy and interest in learning about climate change, as well as climate change beliefs, attitudes, and knowledge. Approximately half of the participants read a refutation text and half read a comparison expository text. Participants then completed a series of multiple choice questions either with or without elaborated refutation-based feedback, creating four mutually exclusive groups based on type of text by type of feedback design. Participants then answered five open-ended questions as a measure of deep conceptual understanding before completing the self-efficacy, interest, beliefs, attitudes, and knowledge measures again. There were no significant interaction effects of text and feedback by time on the variables of interest. However, there was a significant increase in overall interest, beliefs, and knowledge from pretest to posttest. Limitations and future research directions are discussed

Identifikasi Industri Berdasarkan Limbah Yang Menunjang Perekonomian Nelayan Namun Relatif Menurunkan Kualitas Air Dan Produksi Perikanan

Economic development in DKI Jakarta is very fast, so naturally if Jakarta is Indonesia\u27s largest producer of waste, whether from domestic wastes, urban sewage and industrial waste. The purpose of this study was to identify both industrial and industrial fishing industry is relatively non-fishery will support economic and industry relative to lower fish production. In this study grouped the industry that supports the economy and industry that could cause negative impacts on marine resources (inhibiting the community\u27s economy) by using the comparative performance index. Research shows that small-scale fishing industry, medium & large are clean development mechanism (CDM), so that the relative does not pollute the environment and to support the fishing economy, but domestic scale fishing industry and retail traders often use the hazardous and toxic materials so that wastes can pollute the environment and endanger the health of those who consume. Non-fishing industries generally produce wastes hazardous and toxic materials so that tends to pollute and damage the environment. Environmental degradation resulting in decreased productivity, thereby reducing the economy of fishing communities. Order fishing industry that hamper the economy in a row is hazardous and toxic materials-producing industries have no wastewater, Producing hazardous and toxic materials Wastewater Treatment Plant do not always operate, garment, Producing hazardous and toxic materials there Wastewater Treatment Plant, Producing hazardous and toxic materials there is Wastewater Treatment Plant, there is a demand ecolabelling and Retailers & domestic fishing industry. Water quality in North Jakarta Coastal was bad category

Rancang Bangun Kontrol Logika Fuzzy-PID Pada Plant Pengendalian PH (Studi Kasus: Konsentrasi Asam Lemah Dan Basa Kuat)

Telah dilakukan perancangan plantpengendalianpH asamlemahdenganbasakuat dengan menggunakan metode Kontrol Logika Fuzzy-PID dengan Feedback secara real plant. Sistem ini terdiri dari beberapa komponen yaitu sensor pH, pH meter, transmiter,mikrokontroler, driver motor, pompa dc sebagai aktuator, power supply, dan komputer. Kontrol Logika fuzzy-PID berhasil diterapkan pada plant untuk men-schedule gain proporsional, integral dan derivatif yang berorientasi pada performa sistem dengan menggunakan nilai eror dan Perubahan eror sebagai input. Sinyal kontrolnya berupa PWM (Pulse Width Modulation) yang beraksi merubah RPM (Rotate Per Minute) pada pompa larutan basa, sedang RPM pompa larutan asam dijaga konstan. Selain itu, hasil rancang bangun menunjukkan bahwa sistem merespon dengan cara memberi gain-gain pengendali yang sesuai dengan basis aturan (rule base) yang dibuat dengan tujuan memberi respon yang sesuai untuk reaktor guna memperkecil eror. Reaktan yang digunakan adalah NaOH sebagai zat basa pelarut dan CH3COOH sebagai zat asam yang terlarut