Process for Patterning Indium for Bump Bonding

An innovation was created for the Cosmology Large Angular Scale Surveyor for integration of low-temperature detector chips with a silicon backshort and a silicon photonic choke through flipchip bonding. Indium bumps are typically patterned using liftoff processes, which require thick resist. In some applications, it is necessary to locate the bumps close to high-aspect-ratio structures such as wafer through-holes. In those cases, liftoff processes are challenging, and require complicated and time-consuming spray coating technology if the high-aspect-ratio structures are delineated prior to the indium bump process. Alternatively, processing the indium bumps first is limited by compatibility of the indium with subsequent processing. The present invention allows for locating bumps arbitrarily close to multiple-level high-aspect-ratio structures, and for indium bumps to be formed without liftoff resist. The process uses the poor step coverage of indium deposited on a silicon wafer that has been previously etched to delineate the location of the indium bumps. The silicon pattern can be processed through standard lithography prior to adding the high-aspect-ratio structures. Typically, high-aspectratio structures require a thick resist layer so this layer can easily cover the silicon topography. For multiple levels of topography, the silicon can be easily conformally coated through standard processes. A blanket layer of indium is then deposited onto the full wafer; bump bonding only occurs at the high points of the topography

Pemeliharaan Sistem DC di PLTGU Muara Tawar

Sistem DC PLTGU Muara Tawar 240V DC terdiri dari baterai, penyearah dan inverter. Peralatan ini memerlukan perawatan rutin karena sistem DC merupakan sistem yang menyediakan daya cadangan jika terjadi gangguan listrik dan bertindak sebagai pengontrol pompa-pompa tertentu dalam mekanisme produksi. Kelalaian merawat perangkat secara teratur dapat mengakibatkan kerusakan pada perangkat dan mengganggu kinerjanya. Oleh karena itu, kami melakukan observasi langsung terhadap pemeliharaan sistem DC tersebut. Prosedur perawatan dilakukan dengan mengamati secara visual setiap tampilan perangkat dan membersihkan perangkat

The relationship between smolt and postsmolt growth for Atlantic salmon (Salmo salar) in the Gulf of St. Lawrence

The interaction of ocean climate and growth conditions during the postsmolt phase is emerging as the primary hypothesis to explain patterns of adult recruitment for individual stocks and stock complexes of Atlantic salmon (Salmo salar). Friedland et al. (1993) first reported that contrast in sea surface temperature (SST) conditions during spring appeared to be related to recruitment of the European stock complex. This hypothesis was further supported by the relationship between cohort specific patterns of recruitment for two index stocks and regional scale SST (Friedland et al., 1998). One of the index stocks, the North Esk of Scotland, was shown to have a pattern of postsmolt growth that was positively correlated with survival, indicating that growth during the postsmolt year controls survival and recruitment (Friedland et al., 2000). A similar scenario is emerging for the North American stock complex where contrast in ocean conditions during spring in the postsmolt migration corridors was associated with the recruitment pattern of the stock complex (Friedland et al., 2003a, 2003b). The accumulation of additional data on the postsmolt growth response of both stock complexes will contribute to a better understanding of the recruitment process in Atlantic salmon

A prototype system for detecting the radio-frequency pulse associated with cosmic ray air showers

The development of a system to detect the radio-frequency (RF) pulse associated with extensive air showers of cosmic rays is described. This work was performed at the CASA/MIA array in Utah, with the intention of designing equipment that can be used in conjunction with the Auger Giant Array. A small subset of data (less than 40 out of a total of 600 hours of running time), taken under low-noise conditions, permitted upper limits to be placed on the rate for pulses accompanying showers of energies around $10^{17}$ eV.Comment: 53 pages, LaTeX, 19 figures, published in Nuclear Instruments and Methods. Revised version; some references update

Process for Fabrication of Superconducting Vias for Electrical Connection to Groundplane in Cryogenic Detectors

Disclosed are systems, methods, and non-transitory computer-readable storage media for fabrication of silicon on insulator (SOI) wafers with a superconductive via for electrical connection to a groundplane. Fabrication of the SOI wafer with a superconductive via can involve depositing a superconducting groundplane onto a substrate with the superconducting groundplane having an oxidizing layer and a non-oxidizing layer. A layer of monocrystalline silicon can be bonded to the superconducting groundplane and a photoresist layer can be applied to the layer of monocrystalline silicon and the SOI wafer can be etched with the oxygen rich etching plasma, resulting in a monocrystalline silicon top layer with a via that exposes the superconducting groundplane. Then, the fabrication can involve depositing a superconducting surface layer to cover the via

Multimode bolometer development for the PIXIE instrument

The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission concept designed to measure the polarization and absolute intensity of the cosmic microwave background. In the following, we report on the design, fabrication, and performance of the multimode polarization-sensitive bolometers for PIXIE, which are based on silicon thermistors. In particular we focus on several recent advances in the detector design, including the implementation of a scheme to greatly raise the frequencies of the internal vibrational modes of the large-area, low-mass optical absorber structure consisting of a grid of micromachined, ion-implanted silicon wires. With $\sim30$ times the absorbing area of the spider-web bolometers used by Planck, the tensioning scheme enables the PIXIE bolometers to be robust in the vibrational and acoustic environment at launch of the space mission. More generally, it could be used to reduce microphonic sensitivity in other types of low temperature detectors. We also report on the performance of the PIXIE bolometers in a dark cryogenic environment.Comment: 10 pages, 7 figure

Childhood Sexual Abuse Among University Students in Tanzania

Objectives: There are no prevalence data for childhood sexual abuse among Tanzanian university students. This investigation addressed this paucity. The nature of sexual abuse was also investigated. Method: Participants (N= 487) from a university in Tanzania completed a questionnaire which assessed abusive childhood sexual experiences, gathering information about age of victim, duration of abuse, perpetrators, amount of force or persuasion involved, and potential causes of child sexual abuse. A number of individuals were also interviewed about their experiences. Results: The overall prevalence rate for child sexual abuse was 27.7%, with rates being higher for females than for males. The average age of the victim when abuse occurred was 13.8 years. Perpetrators were generally unidentified by respondents; nonetheless, a surprisingly high proportion of female perpetrators was noted. There was a considerable amount of force or persuasion involved in the abusive behavior: betrayal of trust, bribes and physical force were cited frequently. Poverty and superstition were the primary explanations given for child sexual abuse. Conclusion: The study provides evidence for the existence of child sexual abuse in Tanzania. Poverty feeds the “sugar daddy/mammy” phenomenon and combined with various forms of superstition is an important factor in child sexual abuse in Tanzania

ENHANCED VIDEO AND WEB CONFERENCING SECURITY FOR DUAL ACCOUNT ENDPOINTS

Dual account video and web conferencing endpoints have both a personal user account and a shared room account that are registered on the same device. When such an endpoint joins a meeting (e.g., after completing a pairing process) it raises a number of security, etc. challenges. To address these types of challenges, various solutions are presented herein through several techniques. In particular, the techniques may include support for devices utilizing proximity in a reverse fashion (i.e., personal mode endpoints may use ultrasound pairing to detect that the personal user is in proximity to a device and allow them to perform authenticated actions directly using the device’s user interface (UI)). The techniques may further provide a way of pairing personal devices with clients without the need for ultrasound or manual pairing

Rapid prototyping of diffractive optical elements in microstructured sol-gel hybrid material

International audienceTELECOM Bretagne and HOLOTETRIX Company fabricate diffractive optical elements in photoresist by direct-write through a reconfigurable mask. The project is to transfer microstructured patterns of photoresist element to sol-gel hybrid material. This material offers better properties than photoresist to make diffractive optics

ISU Student Organic Farm

The ISU Student Organic Farm (SOF) is a student-operated club with a mission to create a functional organic farm that meets production, educational, and marketing goals. Specifically, farm objectives are: 1) to practice and research organic production methods, 2)to educate community members and encourage active community participation, and 3) to support a local food system with a diversity of market outlets, including charitable donation