Observations of galaxies and primordial radiation suggest that the Universe is made mostly of non-luminous dark matter
. Several new types of fundamental particle have been proposed as candidates for ...dark matter
, such as weakly interacting massive particles (WIMPs)
. These particles would be expected to interact with nuclei in suitable detector materials on Earth, for example, causing them to recoil. However, no definitive signal from such dark-matter interactions has been detected despite concerted efforts by many collaborations
. One exception is the much-debated claim by the DAMA collaboration of a statistically significant (more than nine standard deviations) annual modulation in the rate of nuclear interaction events. Annual modulation is expected because of the variation in Earth's velocity relative to the Galaxy's dark-matter halo that arises from Earth's orbital motion around the Sun. DAMA observed a modulation in the rate of interaction events in their detector
with a period and phase consistent with that expected for WIMPs
. Several groups have been working to develop experiments with the aim of reproducing DAMA's results using the same target medium (sodium iodide)
. To determine whether there is evidence for an excess of events above the expected background in sodium iodide and to look for evidence of an annual modulation, the COSINE-100 experiment uses sodium iodide as the target medium to carry out a model-independent test of DAMA's claim. Here we report results from the initial operation of the COSINE-100 experiment related to the first task
. We observe no excess of signal-like events above the expected background in the first 59.5 days of data from COSINE-100. Assuming the so-called standard dark-matter halo model, this result rules out spin-independent corrected WIMP-nucleon interactions as the cause of the annual modulation observed by the DAMA collaboration.
. The exclusion limit on the WIMP-sodium interaction cross-section is 1.14 × 10
cm
for 10-GeV c
WIMPs at a 90% confidence level. The COSINE-100 experiment will continue to collect data for two more years, enabling a model-independent test of the annual modulation observed by the DAMA collaboration.
The recent discovery and evidence of neutrino signals from distant sources, TXS 0506+056 and NGC 1068 respectively, provide opportunities to search for rare interactions of neutrinos that they might ...encounter on their paths. One potential scenario of interest is the interaction between neutrinos and dark matter, which is invisible and expected to be abundantly spread over the Universe. Various astrophysical observations have implied the existence of dark matter. When high-energy neutrinos from extragalactic sources interact with dark matter during their propagation, their spectra might show suppressions at specific energy ranges, where such interactions occur. These attenuation signatures from the interaction might be measurable on Earth with large neutrino telescopes such as the IceCube Neutrino Observatory. This analysis is focused on the search for rare interactions of high-energy neutrinos from the IceCube-identified astrophysical neutrino sources with dark matter in sub-GeV masses and several benchmark mediator cases using the upgoing track-like events. In this poster, sensitivity studies about the interaction of neutrinos and dark matter are presented.
An upgrade to the IceCube Neutrino Telescope is currently under construction. For this IceCube Upgrade, seven new strings will be deployed in the central region of the 86 string IceCube detector to ...enhance the capability to detect neutrinos in the GeV range. One of the main science objectives of the IceCube Upgrade is an improved calibration of the IceCube detector to reduce systematic uncertainties related to the optical properties of the ice. We have developed a novel optical camera and illumination system that will be part of 700 newly developed optical modules to be deployed with the IceCube Upgrade. A combination of transmission and reflection photographic measurements will be used to measure the optical properties of bulk ice between strings and refrozen ice in the drill hole, to determine module positions, and to survey the local ice environments surrounding the sensor module. In this contribution we present the production design, acceptance testing, and plan for post-deployment calibration measurements with the camera system.
Observations of galaxies and primordial radiation suggest that the Universe is made mostly of non-luminous dark matter. Several types of new fundamental particles have been proposed as candidates for ...dark matter such as weakly interacting massive particles (WIMPs) but no definitive signal has been seen despite concerted efforts by many collaborations. One exception is the much-debated claim by the DAMA collaboration of a statistically significant annual modulation in the event rate of their experiment with a period and phase consistent with that expected from WIMP dark matter. Several groups have been working to develop experiments with the aim of reproducing DAMA's results using the same target medium. Here we report results from the initial operation of the COSINE-100 experiment. COSINE-100 uses sodium iodide as the target medium-the same medium as DAMA-and is designed to carry out a model-independent test of DAMA's claim. Initial data based on the first 59.5 days indicate that there is no excess of events over the expected background, confirming that DAMA's annual modulation signal is in severe tension with results from other experiments under the assumption of dark matter having spin independent interactions and the Standard Halo Model. COSINE-100 is now taking data to study the presence of dark matter-induced annual modulation in the event rate of the sodium iodide detectors.
With the growth of memory capacity and density, test cost and yield improvement are becoming more important. In the case of embedded memories for systems-on-a-chip (SOC), built-in redundancy analysis ...(BIRA) is widely used as a solution to solve quality and yield issues by replacing faulty cells with extra good cells. However, previous BIRA approaches focused mainly on embedded memories rather than commodity memories. Many BIRA approaches require extra hardware overhead to achieve the optimal repair rate, which means that 100% of solution detection is guaranteed for intrinsically repairable dies, or they suffer a loss of repair rate to minimize the hardware overhead. In order to achieve both low area overhead and optimal repair rate, a novel BIRA approach is proposed and it builds a line-based searching tree. The proposed BIRA minimizes the storage capacity requirements to store faulty address information by dropping all unnecessary faulty addresses for inherently repairable die. The proposed BIRA analyzes redundancies quickly and efficiently with optimal repair rate by using a selected fail count comparison algorithm. Experimental results show that the proposed BIRA achieves optimal repair rate, fast analysis speed, and nearly optimal repair solutions with a relatively small area overhead.
Applicability of a powdered activated carbon impregnated alginate beads (ABPAC) was examined toward simultaneous removal of heavy metal (cadmium) and volatile organic compound (benzene) from water. ...Sorption of cadmium and benzene by ABPAC was investigated in both single and binary systems as a function of contact time (1h–11d), initial pH (4–7), and initial concentration of cadmium and benzene (10–600mgL–1). The sorption capacity of APBAC for cadmium and benzene was 149.32 and 89.60mgg–1, respectively. Sorption kinetics was well described by the pseudo-second-order model with correlation coefficients, R2>0.994. Cadmium sorption capacity increased from 41.76 to 56.09mgg–1 with increasing pH from 4 to 7, while benzene sorption was not much influenced. The Langmuir model best correlated with adsorption of cadmium and benzene on ABPAC. Our results indicated no competition effects in a binary-contaminant system, which proves the practical utility of ABPAC for the concurrent sorptive removal of aqueous phase heavy metals and volatile organic compounds.
•Powdered activated carbon impregnated alginate beads (ABPAC) adsorbent was developed.•ABPAC effectively removed cadmium and benzene from aqueous phase.•No competitive effect was observed in the binary-component system.•ABPAC can be used for simultaneous removal of heavy metal and volatile organic compound.
Although soil contamination must be remediated by the polluters under current legal frameworks in numerous countries, the allocation of responsibilities for soil clean-up is still challenging in the ...case of multiple potentially responsible parties (PRPs). This study evaluated the individual contributions of two PRPs (Owners A & B) to heavy metal contamination in the soil environment near an abandoned smelter and compared the results with those from the conventional Gore Factor (GF) method. The soil in the study area was widely contaminated by various heavy metals. In particular, the arsenic concentration exceeded the local regulatory level of 25 mg kg−1 at all investigated sites. Arsenic components were frequently observed in the form of iron oxides, and they decreased with increasing distance from the smelter chimney. This distribution supported the premise that the arsenic mainly originated from the chimney through oxidation processes of iron-containing ores under high temperature. The GF results attributed greater responsibility to Owner A than Owner B, while the estimated arsenic masses (based on the field investigation) indicated the contrary. These results could be caused by insufficient information for the GF evaluation, because the change in smelter ownership and long history of contamination obscure important data, such as the amount of total refined ores and the efficiency of air pollution prevention facilities in the smelter. Therefore, more field-based approaches must be considered more importantly for the evaluation of multiple PRPs' remediation responsibilities, especially in areas with long-term contamination.
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•Individual contribution of two smelter owners to soil contamination was evaluated.•Arsenic pollution decreased with increasing distance from the smelter chimney.•Conventional GF evaluation can often distort the individual contribution results.•Pollutants released by the former owner were preserved well in the reclaimed sites.•Field evidences must be prioritized to allocate remediation responsibilities.
As memory capacity and density grow, a corresponding increase in the number of defects decreases the yield and quality of embedded memories for systems-on-chip as well as commodity memories. For ...embedded memories, built-in redundancy analysis (BIRA) is widely used to solve quality and yield issues by replacing faulty cells with healthy redundant cells. Many BIRA approaches require extra hardware overhead in order to achieve optimal repair rates, or they suffer a loss of repair rate in minimizing the hardware overhead. An innovative BIRA approach is proposed to achieve optimal repair rates, lower area overhead, and increase analysis speed. The proposed BIRA minimizes area overhead by eliminating some storage coverage for only must-repair faulty information. The proposed BIRA analyzes redundancies quickly and efficiently by evaluating all nodes of a branch in parallel with a new analyzer which is simple and easy-to-implement. Experimental results show that the proposed BIRA allows for a much faster analysis speed than that of the state-of-the-art BIRA, as well as the optimal repair rate, and relatively small area overhead.
With the aging society, musculoskeletal degenerative diseases are becoming a burden on society, and rotator cuff disease is one of these degenerative diseases. The purpose of this study was to ...examine the incidence of shoulder osteoarthritis and the etiologic factors of rotator cuff disease in the Korean elderly population. A total of 102 patients performing ultrasonography were recruited, and their demographic factors were analyzed. As functional factors, visual analog scale and the peak torque of external and internal rotators of the shoulder using an isokinetic dynamometer were measured. As an anatomical factor, the acromiohumeral distance in the plain radiograph of the glenohumeral anterior-posterior view was used. There were more female patients (65.7%) than male patients (34.3%). The age range with the highest number of respondents was 50-59 years old. The mean visual analogue score was 4.09 (Min 1 to Max 9). Age and dominant hand side factors appear to be the crucial etiologic factors of the presence and severity of rotator cuff disease. The lower net value of the external rotator strength is weakly related to the presence of rotator cuff disease after adjusting for age, and this is the only modifiable factor in the study.
To accomplish a high-speed test on low-speed automatic test equipment (ATE), a new instruction-based fully programmable memory built-in self-test (BIST) is proposed. The proposed memory BIST ...generates a highspeed internal clock signal by multiplying an external low-speed clock signal from an ATE by a clock multiplier embedded in a DRAM. For maximum programmability and small area overhead, the proposed memory BIST stores the unique sets of instructions and corresponding test sequences that are implicit within the test algorithms that it receives from an external ATE. The proposed memory BIST is managed by an external ATE on-the-fly to perform complicated and hard-to-implement functions, such as loop operations and refresh-interrupts. Therefore, the proposed memory BIST has a simple hardware structure compared to conventional memory BIST schemes. The proposed memory BIST is a practical test solution for reducing the overall test cost for the mass production of commodity DDRx SDRAMs.
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