Estimation of Regional Scale Evapotranspiration Through Analysis of Satellite Thermal-infrared Data

Since the mid 70's the LANDSAT series of satelites has acquired visible and near-infrared observations of the earth at a frequency and spatial resolution suitable for agriculture assessment purposes. More recently satellite systems have acquired high precision thermalinfrared data relating to surface thermal properties and moisture status. A data set from the Heat Capacity Mapping Mission [1] illustrates the potential applications of such data for inferring evapotranspiration on a regional scale. Methods described previously [2] are utilized to estimate evapotranspiration rates, yielding results which are consistent with surface measurements of pan evaporation.     

消除产品良率隐藏的杀手--电子束检查是铜逻辑和晶圆代工厂的最佳方法

监控和消除隐藏的电路缺陷已成为130nm和130nm以下器件的关键。这使得电子束检查正在广泛应用于开发、试生产和量产的监控过程。我们将描述当前铜逻辑和晶圆代工厂电子束检查技术的执行情况,其中包括详细的案例研究,它说明了从开发到量产过程中应用电子束检查技术的好处。我们也描述了过去克服通用工具障碍的方法。然后,分别介绍了利用电子束检查技术的新进展,以及为假设的20000WSPMφ300mm工厂模拟的最理想执行情况的最佳实例。     

Still Alive: Extending Keep-Alive Intervals in P2P Overlay Networks

Detecting node failures within Peer-to-Peer networks is an inherent trade-off between timely detection and consuming bandwidth on network maintenance. In the absence of user-driven messages, the majority of P2P networks rely upon the exchange of periodic keep-alive messages to maintain connections and network topology. We investigate three novel algorithms which prioritise keep-alive messages to nodes that are more likely to have failed. In doing so, these algorithms significantly reduce the expected delay between failures occurring and their subsequent detection in comparison to the standard approach, whilst consuming similar levels of bandwidth. Our algorithms build upon several studies that have shown that older peers are more likely to remain in the network than their short-lived counterparts. Each of our algorithms increase the interval between successive keep-alive messages as peers age in the system, based upon the distribution of peer session times and the current age of peers. We extensively describe the details of each algorithm, before comparing them to the standard periodic approach using simulations based upon measured network data. Furthermore, we show that these algorithms are complimentary to existing gossip-based mechanisms and investigate alternate methods of ascertaining a node??s age so that our algorithms can be robustly deployed in untrustworthy environments.     

Frequency dependence of glass encapsulated electrometer resistors

The frequency dependence of the resistance of commercial 1-1000 GΩ electrometer resistors has been measured from 30 Hz to 30 kHz. When scaled appropriately, the data for devices of similar geometry fall on a single curve, indicating that the frequency dependence is due to distributed capacitance, rather than to frequency dependence of the resistivity. The results are important for understanding noise performance when these devices are used as gate bias resistors in low-noise junction field effect transistor circuits     

Comparison of the effects of ionizing radiation at twelve dose rates from 0.0015 to 100 rad(Si)/s

Evidence is presented that two competing failure mechanisms exist in the Si-SiO₂ system with one mechanism dominating at low dose rates and the other at high. Much lower dose failures than expected were discovered at low dose rates (<0.1 rad(Si)/s) and very low dose rates (∼0.001 rad(Si)/s) in commercial SGS 4007 CMOS devices. These failure doses plotted versus dose rate have a bell-shaped curve, rather than the expected straight line (decreasing with increasing dose rate), indicating that a different failure mechanism is dominant at low dose rates than at high.     

Stress relieving and its effect on life of welded tubular joints

This paper describes investigations into the fabrication and repair of large welded tubular joints and how the processes used affect fatigue life. Research has been conducted to determine the benefit of local post weld heat treatment (PWHT) of the connections in terms of hardness and residual stress. The use of hole drilling and trepanning techniques for residual stresses measurements in the clusters are described. The results are compared with fitness-for-service assessments and considered in relation to the fatigue performance of the welded connections. Very substantial theoretical improvement in fatigue life can be expected after PWHT.     

Occurrence of α- and β-nortestosterone residues in the urine of injured male cattle

The administration of anabolic steroids, for the purposes of growth promotion, to food-producing animals is banned in the EU. Among the compounds covered by this prohibition is ß-nortestosterone (β-NT). This hormone is known to occur naturally in stallions and boars, and its main bovine metabolite, α-nortestosterone (α-NT), occurs naturally in pregnant cows and neonatal calves. However, neither compound is believed to occur naturally in male cattle. During 2006, the presence of α-NT and, on occasion, β-NT was confirmed in male cattle (bulls and steers) slaughtered in Northern Ireland on welfare grounds, as a result of acute injury. Subsequent investigations revealed no evidence of abuse at any of the farms involved and revealed that the phenomenon also occurred in three other regions of the EU, in similarly injured animals. A hypothetical link to release of the adrenal steroid, dehydroepiandrosterone (DHEA), in response to the stress of the injury was tested. Following the intravenous administration of DHEA to two normal steers, β-NT (but not α-NT) was confirmed in the urine of one steer. Thus, it may be concluded that both β-NT and, by implication, α-NT can occur naturally in male cattle (or a specific cohort thereof) in contrast to previously accepted scientific knowledge.     

Use of prostaglandin F2 alpha or gonadotropin releasing hormone in treating problem breeding cows

Ten veterinarians diagnosed and treated 296 cows for reproductive irregularities on 28 dairy farms. Average interval from treatment with 25 mg of prostaglandin F2 alpha (137 cows) to estrus for cows with a corpus luteum (14.6 days) was reduced compared to saline (52 cows) (21.8 days), and a greater percentage (41.6 versus 17.3%) showed estrus within 6 days of treatment. Cows with a cystic corpus luteum (28) were detected in estrus at comparable intervals after prostaglandin F2 alpha or saline (21.8 versus 21.2 days), and similar proportions of cows were detected in estrus within 6 days of treatment (16.7 versus 10.0%). Intervals to estrus among cows with cystic follicles (40 cows) or anestrous cows with follicular ovaries (39 cows) did not differ after treatment with saline or 100 or 200 micrograms of gonadotropin releasing hormone. Within 25 days after treatment, 47.5% of cows with cystic ovaries and 64.1% of anestrous cows showed estrus. Number of cows pregnant after as many as three artificial inseminations of the number examined was 46%, whereas average number of conceptions per service was .32. The long interval from parturition to examination (112 days), the low rate of estrous response after treatment, and the long interval (1.6 estrous cycles) between estruses are consonant with inadequate estrous detection.