Changes In Surface Conditions Research Articles

Impact of surface conditions changes on changes in thermodynamic properties of quasi 2D crystals

In continuation of our research regarding the phonon-induced properties of the low dimensional structures, we are investigating the impact of changes in boundary parameters onto the thermodynamic properties of the quasi 2D crystals (ultrathin films). Internal energy and thermal capacitance of the ultrathin film are theoretically analyzed and numerically and graphically presented for the various combinations of boundary surface parameters. This research is motivated by efforts to explain many unusual thermal properties of novel two-dimensional materials. The obtained results are also of great significance for the heat removal and other important physical properties and processes in ultrathin films, with special emphasis to the improvement of the superconducting properties towards the high TC superconductivity.

Spectral albedo of coastal landfast sea ice in Prydz Bay, Antarctica

AbstractThe surface spectral albedo was measured over coastal landfast sea ice in Prydz Bay (off Zhongshan Station), East Antarctica from 5 October to 26 November of 2016. The mean albedo decreased from late-spring to early-summer, mainly responding to the change in surface conditions from dry (phase I) to wet (phase II). The evolution of the albedo was strongly influenced by the surface conditions, with alternation of frequent snowfall events and katabatic wind that induce snow blowing at the surface. The two phases and day-to-day albedo variability were more pronounced in the near-infrared albedo wavelengths than in the visible ones, as the near-infrared photons are more sensitive to snow metamorphism, and to changes in the uppermost millimeters and water content of the surface. The albedo diurnal cycle during clear sky conditions was asymmetric with respect to noon, decreasing from morning to evening over full and patchy snow cover, and decreasing more rapidly in the morning over bare ice. We conclude that snow and ice metamorphism and surface melting dominated over the solar elevation angle dependency in shaping the albedo evolution. However, we realize that more detailed surface observations are needed to clarify and quantify the role of the various surface processes.

Major Controls on Streamflow of the Glacierized Urumqi River Basin in the Arid Region of Northwest China

Understanding the main drivers of runoff availability has important implications for water-limited inland basins, where snow and ice melt provide essential input to the surface runoff. This paper presents an analysis on the runoff response to changes in climatic and other controls of water-energy balance in an inland glacierized basin, the Urumqi River basin, located in the arid region of northwest China, and identifies the major control to which runoff is sensitive across the basin’s heterogeneous subzones. The results indicate that the runoff is more sensitive to change in precipitation in the mountainous headwaters zone of the upper reach, and followed by the impact of basin characteristics. In contrast, the runoff is more sensitive to changes in the basin characteristics in the semiarid and arid zones of the mid and lower reaches. In addition, the change in basin characteristics might be represented by the distinct glacier recession in the mountainous upper reach zone and the increasing human interferences, i.e., changes in land surface condition and population growth, across the mid and lower reach zones. The glacier wasting contributed around 7% on average to the annual runoff between 1960 and 2012, with an augmentation beginning in the mid-1990s. Findings of this study might help to better understand the possible triggers of streamflow fluctuation and the magnitude of glacier wasting contribution to runoff in inland glacierized river basins.

Multi-objective optimization of rolling schedule for tandem cold strip rolling based on NSGA-II

Abstract A multi-objective optimization model of rolling schedule based on NSGA-II algorithm was presented, and three objective functions are defined as motor power balance, good flatness and preventing slippage. The experimental results show the excellent performance of NSGA-II in obtaining non-dominated front which could suggest several alternative solutions to rolling schedule in a single run of the algorithm. Additionally, considering that the rolling load distribution strategy dynamically adjusts are required to balance the impact of roll surface condition changes on the rolling process, a model of weighted-sum approach with variable weight coefficients based on rolling length was proposed. In this model, a roll change cycle was divided into four optimization stages which are given different weight coefficients. Moreover, a smooth correction model of weight coefficient was proposed to ensure the quality of strip flatness. Compared to the traditional weighted-sum approach, the presented model on the basis of variable weight coefficients can make full use of Pareto set, and has better adaptability to changing rolling conditions. Finally, the proposed model was applied to the multi-objective optimization model above, the results showed that the final optimal solutions have better performance in almost all objective dimensions than the empirical one. The practical application has further confirmed the effectiveness of the multi-objective optimization for rolling schedule.

Changes in hydrological behaviours triggered by earthquake disturbance in a mountainous watershed

Landslides induced by strong earthquakes often destroy large amounts of landscape vegetation which can trigger significant changes in runoff potential and flood flow. Little is known about hydrological behaviours imposed by co-seismic landslides and their post-earthquake evolution. Therefore, we collected time-series datasets (2007–2018) of underlying surface conditions (USC) changes including landslide expansion and recovery in a watershed affected by the Wenchuan earthquake to further quantify how the large physical disturbance affected the flood hydrological behaviours. The hydrological model HEC-HMS was calibrated and validated to predict the historical hydrological behaviours based on 5 min time-series data in rainfalls and streamflow (2018–2019), showing a good model performance with a mean Nash–Sutcliffe efficiency of 0.76. It was found that, shortly after the earthquake, the sharp expansion with 11% of landslide areas elevated the magnitudes of runoff potential, peak discharge, and runoff volume by >10%, and the peak to time for the high-magnitude flood was advanced by 25 min compared to the pre-earthquake levels. The tipping point along the hydrological disturbance–recovery trajectory was detected within 2011 with higher flood peaks and volumes, and the periods of 2011–2013 (i.e. 3–5 years post-earthquake) were deemed to be a rapid recovery period, revealing an unstable hydrological function. These findings are significant for clearly understanding the magnitude and timing, as well as greater risks of post-earthquake catastrophic flooding in earthquake-stricken regions. Additionally, the post-earthquake accompanied rainstorm-induced geohazards, which limited the recovery of landscape vegetation, triggering an undulant but clear recovery process (1–7 years post-earthquake) of hydrological behaviours. These findings promoted our understanding of the spatiotemporal evolution of hydrological behaviours triggered by the earthquake, and further contribute to the development of adaptation and mitigation strategies for the unpredictable flash floods triggered by future abrupt natural hazards in earthquake-affected regions.

Surface Roughness Estimation in the Orog Nuur Basin (Southern Mongolia) Using Sentinel-1 SAR Time Series and Ground-Based Photogrammetry

This study demonstrates an application-oriented approach to estimate area-wide surface roughness from Sentinel-1 time series in the semi-arid environment of the Orog Nuur Basin (southern Mongolia) to support recent geomorphological mapping efforts. The relation of selected mono- and multi-temporal SAR features and roughness is investigated by using an empirical multi-model approach and selected 1D and 2D surface roughness indices. These indices were obtained from 48 high-resolution ground-based photogrammetric digital elevation models, which were acquired during a single field campaign. The analysis is backed by a time series analysis, comparing Sentinel-1 features to temporal-corresponding observations and reanalysis datasets on soil moisture conditions, land surface temperature, occurrence of precipitation events, and presence and development of vegetation. Results show that Sentinel-1 features are hardly sensitive to the changing surface conditions over none to sparsely vegetated land, indicating very dry conditions throughout the year. Consequently, surface roughness is the dominating factor altering SAR intensity. The best correlation is found for the combined surface roughness index Z-Value (ratio between the root mean square height and the correlation length) and the mean summer VH intensity with an r2 coefficient of 0.83 and an Root-Mean-Square Error of 0.032.

Assessing the Impact of Changes in Land Surface Conditions on WRF Predictions in Arid Regions

AbstractA thorough evaluation of the Weather Research and Forecasting (WRF) Model is conducted over the United Arab Emirates, for the period September 2017–August 2018. Two simulations are performed: one with the default model settings (control run), and another one (experiment) with an improved representation of soil texture and land use land cover (LULC). The model predictions are evaluated against observations at 35 weather stations, radiosonde profiles at the coastal Abu Dhabi International Airport, and surface fluxes from eddy-covariance measurements at the inland city of Al Ain. It is found that WRF’s cold temperature bias, also present in the forcing data and seen almost exclusively at night, is reduced when the surface and soil properties are updated, by as much as 3.5 K. This arises from the expansion of the urban areas, and the replacement of loamy regions with sand, which has a higher thermal inertia. However, the model continues to overestimate the strength of the near-surface wind at all stations and seasons, typically by 0.5–1.5 m s−1. It is concluded that the albedo of barren/sparsely vegetated regions in WRF (0.380) is higher than that inferred from eddy-covariance observations (0.340), which can also explain the referred cold bias. At the Abu Dhabi site, even though soil texture and LULC are not changed, there is a small but positive effect on the predicted vertical profiles of temperature, humidity, and horizontal wind speed, mostly between 950 and 750 hPa, possibly because of differences in vertical mixing.

Splash erosion affected by initial soil moisture and surface conditions under simulated rainfall

Soil erosion by water is one of the most severe soil degradation processes. Splash erosion is the initial stage of soil erosion by water, resulting from the destructive force of rain drops acting on soil surface aggregates. Apart from rainfall properties, constant soil physical properties (texture and soil organic matter) are crucial in understanding the splash erosion. However, there is lack of information about the effect of variable soil properties such as soil initial water content and surface condition (seal formation) on splash erosion. The objective of the present study was to determine how initial water content and surface condition affected soil splash erosion under simulated rainfall. The changes in soil surface condition were characterized by hydraulic variability (saturated hydraulic conductivity) due to surface seal formation. Slit loam and loamy sand soil textures were used in the experiment. The soil samples were collected from the top layer; air dried, and filled into modified Morgan splash cups for splash erosion measurements. Rainfall was created in the laboratory using two types of rainfall simulators covering intensity range from 28 to 54 mm h−1 and from 35 to 81 mm h−1. The soil samples were exposed to three consecutive rainfall simulations with different time intervals between simulations and different initial water content and surface conditions (air-dried, wet-sealed, and dry-crusted). Wet-sealed soil samples had up to 70% lower splash erosion rate compared to air-dried samples, due to surface ponding followed by seal formation. A significant decrease in soil saturated hydraulic conductivity indicated the formation of surface seal for silt loam soils. A non-significant decrease in saturated hydraulic conductivity for loamy sand soil was attributed to earlier formation of stable seals. Two different rainfall simulators produced different amount of splash erosion rates; however, the splash erosion development for increasing rainfall intensity was almost equal considering same initial surface condition. These results provide insight into dynamic changes of individual soil parameters affected by rainfall, and could find wider application for more complex soil erosion prediction models.

Contribution of Images ETM and GIS for the Detection of Dynamic Changes in Steppic Space in the Wilaya of Naama Under the Combined Effect of Climate Change and Socio-Spatial Mutations

This paper highlights the contribution of landsat images to the dynamic monitoring of the steppe area in the high Oran plains (Algeria). The qualitative and quantitative analysis of the rapid evolution of the landscape and especially the silting up in the cities demonstrate an interesting measurement which allows making a provisional assessment of the current state of the study area. This analysis will raise awareness among the population; the local elected officials and the decision maker about the extent of the sanding phenomenon. By using this analysis, the changes in surface condition between 1957 and 2002 which extracted from different images of Lands at MSS, TM and ETM+had been done. Consequently, three methods of detection of changes (rapid identification and quantification of changes, multidate colored composition technique and dynamic soil cover index techniques) were used to locate the different zones where underwent deep mutations, the special extension of the silting up and the degradation of the grounds inside the regions of the wilaya of Naâmaregion.It is important to note that we used the Olsson model for atmospheric corrections of images. This study is conducted in the high Oran plain which is administratively attached to the wilaya (department) of Naâma. It covers an area of 29,825 km2, between 32°08’and 34°16’ north latitude and 0°09’and 1°43’ west longitude. The use of remote sensing data through the dynamic soil covers index and the diachronic color-composite images allowed focusing the different changes that took place from 1987 to 2002. These changes which concern the changes in the ratio of landscape units in the steppe zone necessitate testing several indices of change (vegetation index, gloss index, curass index and principal component analysis) to minimize errors in the assessment of results of these changes. It is well known that the remote sensing for the result of dynamic changes is influenced by cyclical variations (season, weather conditions). Therefore the radiometric and atmospheric corrections to the images are necessary. Emphasis was placed on the processing of diachronic remote sensing data for the monitoring and development of silting in an arid environment concerning the southwestern part of the high Oran plains. In fact, this analysis revealed that for the entire study region, the surface silted areas increased from 1.38% in 1957 to 42.9% in 2002 or an area of 1,280,762 ha; which corresponds to an extension of 28,461.4 ha per year. It is important to note that the diachronic study involved delicate phases, in particular the choice of the mathematical model for the atmospheric correction (absolute or relative) of the satellite images as well as the determination of the parameter of the real reflectance of the soil for the test samples. This parameter requires adequate equipment (spectroradiometer) or a database on the absolute reflectance of objects. Also, in this study it is recognized that the indices are not very effective for detecting change in an arid zone where the characteristics of the soil and the presence of sand considerably influence the spectral aspect of objects.

Comprehensive Analysis of Metal Modulated Epitaxial GaN.

While metal modulated epitaxy (MME) has been shown useful for hyperdoping, where hole concentrations 40 times higher than other techniques have been demonstrated, and the ability to control phase separation in immiscible III-nitrides, the complexity of the dynamically changing surface conditions during the cyclic growth is poorly understood. While MME is capable of superb crystal quality, performing MME in an improper growth regime can result in defective material. These complications have made the transfer of MME knowledge challenging. This work provides a comprehensive study of the conditions necessary for achieving the benefits of MME while avoiding undesirable defects. The effects of growth temperature, Ga/N ratio, and excess Ga dose per MME growth cycle on the morphological, structural, electronic, and optical properties of unintentionally doped (UID) MME grown gallium nitride (GaN) have been investigated. Optimal structural and electrical quality were achieved for GaN films grown at ∼650 °C, at pre-bilayer Ga coverage and at the moderate droplet regime. However, high defect concentrations were observed at the lowest growth temperatures, and counter to traditional MBE, as the excess Ga dose transitioned from bilayer coverage to the low droplet regime. Optoelectronic properties were optimal for films grown at intermediate growth temperatures, an excess Ga dose condition just before the droplet formation, and, at a III/V ratio of 1.3. Optimization of growth temperatures, Ga/N ratios, and excess Ga dose results in a range of growth conditions achieving smooth surfaces, step-flow surface morphology, and high crystalline quality films with low threading dislocation densities, allowing researchers to utilize the extensive advantages of MME.

강교용 도장의 표면상태 평가에 의한 화재온도 추정에 관한 실험적 연구

강교용 도장의 표면상태 평가에 의한 화재온도 추정에 관한 실험적 연구

More frequent summer heat waves in southwestern China linked to the recent declining of Arctic sea ice

Southwestern China (SWC) has suffered from increasing frequency of heat wave (HW) in recent summers. While the local drought-HW connection is one obvious mechanism for this change, remote controls remain to be explored. Based on ERA-5 reanalysis, it is found that the SWC summer HWs are significantly correlated with sea-ice losses in the Barents Sea, Kara Sea and the Arctic pole. The reduction of Arctic sea ice can cause low pressure anomalies over the polar region due to increased heat-flux exchanges at the sea-air interface, which subsequently triggers southeastward Rossby wave trains propagating from northern Europe to East Asia that induce anomalous anticyclone over SWC. As a result, the North Pacific subtropical high extends westward, accompanied by divergent winds, decreased cloud cover and increased insolation in SWC, which leads to above-normal air temperatures there. In addition, the East Asian westerly jet stream is shifted northward, which enhances (reduces) the moisture convergence in North China (SWC), resulting in prominently drier soil in SWC. Therefore, the sea ice—forced changes in atmospheric circulation and surface conditions favor the occurrences of SWC summer HWs.

Study on the effects of harvesting time and storage conditions of Tacca leontopetaloides (L.) Kuntze Tuber in an Giang Province, Vietnam

The study was conducted to determine the harvest time and weight of Tacca tubers (Tacca leontopetaloides (L.) Kuntze) for flour production. It also assessed changes in quality according to pretreatment methods as well as storage conditions over an 8 week period. Results showed that Tacca tubers harvested after 6 months of planting will have a high dry matter content and flour recovery efficiency, especially at month 7th but remains unchanged afterwards. In addition, tubers weighing over 150g will give better flour recovery efficiency. Washing before storage also affects the quality of tubers more than preservation mode. During storage, tuber weight decreases with amount of dry matter increases. Particularly, the amount of sugar, total Saponins and total Polyphenols decreases but Starch content tends to increase slightly after 6 weeks of reduction. Despite the change in color, surface condition and structure, the Tacca tuber retains good sensory properties during storage.

Ice Concentration Retrieval from the Analysis of Microwaves: Evaluation of a New Methodology Optimized for the Copernicus Imaging Microwave Radiometer

A new methodology has been described in Kilic et al. (Ice Concentration Retrieval from the Analysis of Microwaves: A New Methodology Designed for the Copernicus Imaging Microwave Radiometer, Remote Sensing 2020, 12, 1060, Part 1 of this study) to estimate Sea Ice Concentration (SIC) from satellite passive microwave observations between 6 and 36 GHz. The Ice Concentration Retrieval from the Analysis of Microwaves (IceCREAM) algorithm is based on an optimal estimation, with a simple radiative transfer model derived from satellite observations at 0% and 100% SIC. Observations at low and high frequencies have different spatial resolutions, and a scheme is developed to benefit from the low errors of the low frequencies and the high spatial resolutions of the high frequencies. This effort is specifically designed for the Copernicus Imaging Microwave Radiometer (CIMR) project, equipped with a large deployable antenna to provide a spatial resolution of ∼5 km at 18 and 36 GHz, and ∼15 km at 6 and 10 GHz. The algorithm is tested with Advanced Microwave Scanning Radiometer 2 (AMSR2) observations, for a clear scene over the north polar region, with collocated Moderate Resolution Imaging Spectroradiometer (MODIS) estimates and the Ocean Sea Ice—Satellite Application Facilities (OSI SAF) operational products. Several algorithm options are tested, and the study case shows that both high spatial resolution and low errors are obtained with the IceCREAM method. It is also tested for the full polar regions, winter and summer, under clear and cloudy conditions. Our method is globally applicable, without fine-tuning or further weather filtering. The systematic use of all channels from 6 to 36 GHz makes it robust to changes in ice surface conditions and to weather interactions.

Biofouling phenomenon of direct contact membrane distillation (DCMD) under two typical operating modes: Open-loop mode and closed-loop mode

The biofouling mechanism of Direct Contact Membrane Distillation (DCMD) was comprehensively investigated in the present study under two typical operating modes of open-loop mode (mode O) and closed-loop mode (mode C). The experimental results revealed that organic substances tended to attach onto the membrane surface under the mode C, significantly promoting the initial colonization of live bacteria on the membrane. The 16S rRNA analysis revealed that the abundance of live bacteria in the mode C was higher at the early period, which sharply reduced at the later stage. It might be attributed to the increased deposition of salt crystals on the membrane at the later period of DCMD operation. Under the mode C, increasing depositions of organic and inorganic substances can be obtained on the membrane, contributing to the continuous changes of membrane surface conditions and then the remarkable succession of biofilm bacterial community. Comparatively, the biofilms formed under the mode O contained less nutrients and a stable microbial community, resulting in a milder flux decline compared to mode C.

Changes in ice‐wedge activity over 25 years of climate change near Salluit, Nunavik (northern Québec, Canada)

AbstractTo assess the direct impact of climate change on ice‐wedge (IW) degradation, 16 sites in the Narsajuaq river valley (Nunavik, Canada) that were extensively studied between 1989 and 1991 were revisited in 2016, 2017 and 2018. In total, 109 pits were dug to record soil characteristics and IW shapes and depths. Changes in surface conditions were also noted using side‐by‐side comparisons of recent (2017) and older (1989–1991) land and aerial photographs. During the past 25 years, the active layer reached depths that were 1.2–3.4 times deeper than in 1991, which led to the widespread degradation of IWs in the valley. Whereas 94% of the IWs unearthed in 1991 showed multiple recent growth structures, only 13% of the 55 IWs unearthed in 2017 still had some upgrowth stages left. IW tops are now consistently deeper than the main stages of the IWs measured in 1991. In August 2017, however, about half of the IWs had ice veins connecting them to the base of the active layer, an indication that the recent cooling spell (2010 to present) in the region was enough to reactivate frost cracking and IW growth. This paper highlights how sensitive the Arctic soil system can be to short‐term climate variations.

黄土高原流域水沙变化研究进展

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土高原流域水沙变化研究进展 DOI: 10.5846/stxb201909121903 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41822103，41471094）；中国科学院青年促进会项目（2016040） Changes in streamflow and sediment load in the catchments of the Loess Plateau, China: a review Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:人类活动和气候变化是影响流域水文过程的两大驱动因素，径流输沙是流域水文过程的总体反映，变化环境下径流输沙的变化规律与成因分析是水文学和全球变化研究的热点问题。黄土高原是我国水土流失最严重的地区。20世纪50年代以来，黄土高原地区开展了大规模的生态环境建设和水土流失综合治理，显著改变了流域土地利用和植被覆盖。下垫面条件改变与气候变化综合作用，使得流域水沙情势发生剧变。围绕黄土高原流域水沙变化的时空尺度特征与驱动机制，总结了径流输沙和水沙关系变化特征的研究结果，归纳了径流输沙变化的归因分析方法与人类活动和气候变化影响的贡献分割结果，探讨了气候变化、植被恢复、水土保持工程措施以及流域景观格局对水沙变化的影响机制。未来应加强流域水沙演变的时空尺度特征特别是水沙关系非线性特征的定量研究，阐明极端事件对水沙动态的影响与贡献；开展水沙变化影响机制的多要素综合解析，发展耦合地表覆被动态特征和气候变化的降雨-径流-输沙模型，揭示生态恢复与水沙演变过程互馈机制；开展未来气候变化、社会经济发展和生态建设工程情景下水沙动态的趋势预测，为黄土高原生态综合治理和水资源管理与黄河水沙调控提供策略建议。 Abstract:Human activities and climate change are two critical driving forces of catchment hydrological processes, for which, streamflow and sediment load are the two main indicators. Changing trends and attribution analysis of streamflow and sediment load under changing environments are now the focus of hydrological and global change studies. The Loess Plateau (LP) of China is well known for its severe soil erosion and the heavy sediment load of the Yellow River that flows through it. To control soil erosion in the LP, large ecological restoration construction projects and several soil and water conservation measures have been implemented since the 1950s, which have resulted in extensive land use and vegetation cover changes. These extensive changes in land surface conditions in combination with climate change have dramatically altered the hydrological regime, including streamflow, sediment load, and flow-sediment relationships in the LP. The spatio-temporal variability of streamflow and sediment load, and the dominant mechanisms behind these changes are important issues in the development of strategies for sustainable land and water management in the LP. We reviewed previous studies that documented changes in streamflow, sediment load, and flow-sediment relationships to improve our understanding of these processes. The methods used to separate the impacts of human activities and climate change on streamflow and sediment load and the results obtained in these studies are summarized here. The influence of climate change, vegetation restoration, soil and water conservation measures, as well as catchment landscape patterns on driving changes in streamflow and sediment load are also discussed. Finally, the following further studies are proposed:1) Studying the spatio-temporal patterns in streamflow and sediment load evolution and quantifying the non-linear characteristics of flow-sediment relationships, 2) Demonstrating the effects and contributions of extreme events on streamflow and sediment load dynamics, 3) Conducting comprehensive analyses on the influence of multiple factors on streamflow and sediment load, 4) Developing a coupled rainfall-streamflow-sediment yield model that includes the dynamic characteristics of surface cover and climate change, with the aim of revealing feedback mechanisms between ecological restoration and the evolution of streamflow and sediment load, and 5) Predicting streamflow and sediment load dynamics under future scenarios of climate change, with the added effects of socio-economic development and ecological construction engineering; which is likely to provide suggestions for ecological treatment and water resource management in the LP, and regulation of water and sediment in the Yellow River. 参考文献 相似文献 引证文献

Ocean surface warming in Krossfjorden, Svalbard, during the last 60 years

A high-resolution marine sediment core NP16-Kro1-MCB from Krossfjorden, Western Svalbard is studied to investigate changes in sea surface conditions in the fjord during the last 60 years (1953–2014). The diatom-based reconstruction of August sea surface temperature (aSST) demonstrates a clear warming trend of 0.6 °C through the record. As inferred from Marginal Ice Zone (MIZ) diatoms, surface warming occurs in parallel with a decline in sea ice extent (SIE) during recent decades. Factor analysis identified variations in diatom assemblages representing different water masses, showing a dominance of Arctic water diatoms throughout the period and decadal variations in the sea ice assemblage during periods of peak sea ice extent. The strong dominance of Arctic water diatoms along with increasing aSST suggest prolonged open-water conditions and increased sea ice melting in the region throughout the observed period. The reconstructed ocean surface changes are in line with the background warming occurring over the Arctic region. A comparison with instrumental records from neighboring regions supports the quality of the reconstructions, including the average reconstructed aSST and the magnitude of the warming trend. We suggest that increased CO2 forcing together with ocean–atmospheric interaction have caused the increasing SST trend and decreasing sea ice presence in Krossfjorden rather than an increasing influence from Atlantic Water, which has amplified changes in many regions of Svalbard.

Effect of in-wheel motor suspension system on electric vehicle ride comfort

This paper presents the effect of in-wheel motor (IWM) suspension system on electric vehicle (EV) ride comfort. To analyze the impact on the vehicle ride comfort caused by IWM suspension system, a dynamic model of quarter vehicle is established with the combination of IWM and road surface roughness excitations. The weighted root-mean-square (r.m.s.) acceleration of the vertical vehicle body (awbz) according to the international standard ISO 2631-1 (1997) is selected as an objective function to analyze the effect of IWM suspension system when the road surface and IWM mass conditions change. The study results indicate that the effect of IWM suspension system on the EV ride quality is significant and the value of awbz reduces by 8.6 % in comparison to without IWM suspension system. The IWM suspension system has significantly improved the EV ride quality when the road surface and IWM mass conditions change.

MIM Surface Reconditioning Under Knudsen Flow During Metal Deposition Process

Failure analysis revealed that capacitor short-circuit failures were related to a MIM metal missing/peeling defect. During subsequent investigation a correlation between MIM top metal defects and Knudsen flow conditions within the metal deposition system was revealed. MIM surface condition prior to and after top metal deposition was extensively studied. MIM surface characterization showed large size particles formed on the MIM feature after the wafer experienced Knudsen flow. Experiments show such defects could also be produced after multiple oxygen plasma cleans and long staging time of exposed MIM features. These same changes of the MIM surface condition occurred at an accelerated rate under Knudsen flow conditions in the metal deposition system. Inline AOI results showed that when the Knudsen number was at or greater than ~0.2 during vacuum load lock pumping, MIM metal missing/peeling defects were formed, affecting up to 20% of die.