By reconstructing the history of water impoundment in the world's artificial reservoirs, we show that a total of approximately 10,800 cubic kilometers of water has been impounded on land to date, reducing the magnitude of global sea level (GSL) rise by -30.0 millimeters, at an average rate of -0.55 millimeters per year during the past half century. This demands a considerably larger contribution to GSL rise from other (natural and anthropogenic) causes than otherwise required. The reconstructed GSL history, accounting for the impact of reservoirs by adding back the impounded water volume, shows an essentially constant rate of rise at +2.46 millimeters per year over at least the past 80 years. This value is contrary to the conventional view of apparently variable GSL rise, which is based on face values of observation.
[1] Recent studies suggest the increasing contribution of groundwater depletion to global sea-level rise. Groundwater depletion has more than doubled during the last decades, primarily due to increase in water demand, while the increase in water impoundments behind dams has been tapering off since the 1990s. As a result, the contribution of groundwater depletion to sea-level rise is likely to dominate over those of other terrestrial water sources in the coming decades. Yet, no projections into the 21st century are available. Here we present a reconstruction of past groundwater depletion and its contribution to global sea-level variation, as well as 21st century projections based on three combined socio-economic and climate scenarios (SRES) with transient climate forcing from three General Circulation Models (GCMs). We validate and correct estimated groundwater depletion with independent local and regional assessments, and place our results in context of other terrestrial water contributions to sea-level variation. Our results show that the contribution of groundwater depletion to sea-level increased from 0.035 (AE0.009) mm yr À1 in 1900 to 0.57 (AE0.09) mm yr
À1in 2000, and is projected to increase to 0.82 (AE0.13) mm yr À1 by the year 2050. We estimate the net contribution of terrestrial sources to be negative of order À0.15 (AE0.09) mm yr À1 over 1970-1990 as a result of dam impoundment. However, we estimate this to become positive of order +0.25 (AE0.09) mm yr À1 over 1990-2000 due to increased groundwater depletion and decreased dam building. We project the net terrestrial contribution to increase to +0.87 (AE0.14) mm yr À1 by 2050. As a result, the cumulative contribution will become positive by 2015, offsetting dam impoundment (maximum À31 AE 3.1 mm in 2010), and resulting in a total rise of +31 (AE11) mm by 2050. Citation: Wada, Y., L.
We study the impact of phase noise on the downlink performance of a multi-user multiple-input multiple-output system, where the base station (BS) employs a large number of transmit antennas M . We consider a setup where the BS employs Mosc free-running oscillators, and M/Mosc antennas are connected to each oscillator. For this configuration, we analyze the impact of phase noise on the performance of regularized zero-forcing (RZF) precoding, when M and the number of users K are asymptotically large, while the ratio M/K = β is fixed. We analytically show that the impact of phase noise on the signal-to-interference-plusnoise ratio (SINR) can be quantified as an effective reduction in the quality of the channel state information available at the BS when compared to a system without phase noise. As a consequence, we observe that as Mosc increases, the SINR of the RZF precoder degrades as the interference power increases, and the desired signal power decreases. On the other hand, the variance of the random phase variations caused by the BS oscillators reduces with increasing Mosc. Through simulations, we verify our analytical results, and study the performance of the RZF precoder for different phase noise and channel noise variances.
A dual‐band multiple input multiple output (MIMO) antenna with slitted ground is presented. The MIMO antenna consists of two symmetric C‐shaped slots and T‐shaped slots and six pairs of slits. The C‐shaped slots are fed by two 50 Ω microstrip lines, respectively. The antenna can provide two operating bands centred at 2.70 and 3.95 GHz, covering WLAN and WiMAX band, respectively. The isolation of the antenna elements is better than 18 dB across 2.70 GHz‐band and 21 dB across 3.95 GHz‐band, whereas the six pairs of slits play an important role in reducing mutual coupling. Good performances of the proposed antenna over the operating bands are also obtained. The discussion shows that the antenna can be considered as a good candidate for MIMO systems.
The antifungal activity of citronellal, a typical terpenoid of plant essential oils, against Penicllium digitatum and the possible action mode involved were investigated. Results showed that the mycelial growth and spores' germination of P. digitatum were inhibited by citronellal in a dose-dependent manner. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined to be 1.60 lL/mL and 3.20 lL/mL, respectively. It was found that the plasma membrane of citronellal-treated P. digitatum spores was damaged, as confirmed by the propidium iodide stain results, as well as a higher extracellular conductivity and release of cell constituents in citronellal-treated samples than those of control samples. Moreover, in vivo test results demonstrated that wax ? citronellal (WC; 10 9 MFC) treatment effectively reduced the incidence of green mold after 5 days of storage at 25 ± 2°C. These findings suggested that the plasma damage mechanism contributed to the antifungal activity of citronellal against P. digitatum. In addition, citronellal was suggested to be a potential alternative to fungicidal agents in controlling green mold of citrus fruit.
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