The cost estimate for a novel cheap solar cell

The estimate for the lowest cost of SODL (silicon on defect layer) solar cell is made according to the price standard of present market. The estimate shows that the PV (photovoltaics) energy costs can be reduced from today's 25-30 cents/(kW h) to 7-8 cents/(kW h) which is comparable with the present cost of electricity generated by traditional energy sources such as fossil and petroleum fuels. The PV energy costs could be reduced to a value lower than 7-8 cents(kW h) by developing SODL technology. The SODL solar cell manufacture featuring simple processes is suitable to large scale automated assembly lines with high yield of large area cells. Some new ideas are suggested, favoring the further reduction in the cost of commercial solar cells.

克隆植物东方草莓对异质生境的适应对策

克隆植物被认为比非克隆植物更宜于利用异质性环境。在复杂的空间异质环境中，克隆植物可能形成了各种有效利用环境异质性的适应对策。对于克隆植物适应机制的研究，前人已做了大量的工作，特别是从形态和生物量分配等方面对简单异质生境下克隆植物的克隆整合和克隆分工进行了详细的研究。本研究以分布广泛的克隆植物东方草莓（Fragaria orientalis）作为研究对象，应用野外调查和实验生态学方法，采用多对比度单资源模型和不同向双资源模型，从形态和生理生态的角度，研究复杂异质生境下克隆植物的整合和分工及其耗益问题，分析不同类型的生境对克隆植物整合和分工的修饰作用，进而探讨克隆植物对异质生境的适应策略。克隆构型和分株种群特征是植物克隆生长及其生态适应对策研究的基本内容。本文通过野外调查，研究在不同光照条件下东方草莓克隆构型、分株种群特征以及点分布格局。结果表明：东方草莓的克隆构型随光照发生相应的变化，低光照下其匍匐茎节间长和分枝角度均增大而分枝强度减小；随光照减弱，东方草莓分株种群的生物量、根冠比和分株种群密度显著降低；不同光照下东方草莓分株均以随机分布为主但不同尺度下有所差异，其分布格局强度依次为旷地<林缘<林下。结合克隆植物对资源的利用对策，探讨了克隆构型和分株种群特征以及分布格局随环境条件变化的生态适应意义。不同生境斑块条件下克隆植物可能采取不同的适应对策。采用盆栽实验，研究不同水分对比度下克隆整合及其生理生态特征，并对单向和交互资源中东方草莓的克隆整合做了对比研究。结果显示：高的水分对比度能够促进东方草莓的克隆整合，并能刺激相连分株增加光合作用，东方草莓体内的氧化—抗氧化系统也II随对比度做出相应的反应。耗-益分析表明胁迫分株的受益是以供给分株的损耗为代价的，但从克隆片段总体来说是受益的。单向资源中东方草莓生长的绝对值高于交互资源，但耗-益分析表明生长于交互资源下东方草莓的克隆整合获益大于生长于单向资源下东方草莓的克隆整合获益。长期生长于特定生境的克隆植物，在进化过程中其克隆整合和克隆分工在对资源异质性的适应策略方面可能有所侧重。采用盆栽实验对来自不同海拔梯度的东方草莓的克隆整合和克隆分工对异质资源的适应对策进行了研究。实验结果表明，来自高海拔的东方草莓可塑性较差。来自两个海拔的东方草莓对切断匍匐茎的表现有所差异，总体上切断匍匐茎对来自高海拔的东方草莓影响更大些。另外，来自高海拔的东方草莓表现出更高的克隆分工。IIIClonal plants are known to be more suitable for the habitats of heterogeneousresources than nonclonal plants, perhaps due to their well developed adaptivestrategies to environmental heterogeneity. Many studies have been done on theadaptive mechanisms of clonal plants, especially on the clonal integration anddivision of labor with morphology and biomass allocation under simpleheterogeneous habitats. Based on field surveys, laboratory experiments, multi-contrastunidirectional resource model and reciprocal resource model, Fragaria orientalis, aRosaceae stoloniferous herb that widely distributes in China, was used to study thisplant’s morphological and physiological responses to complicated heterogeneoushabitats in terms of its clonal integration, division of labor and cost-benefit, as well astheir modifications by different habitats, so as to better understand the adaptivestrategies of clonal plants under heterogeneous environments.Clonal architecture and ramet population characteristics are of the major concernin the studies on growth and adaptive strategies of clonal plants. Clonal architecture,ramet population characteristics and spatial point pattern of F. orientalis underdifferent light intensity were studied with field observations. The results showed that,clonal architecture changed with light availability: Internode-lengths and branchangels of stolons were larger while branch intensities were smaller under lower lightintensity than those under higher light intensity; Biomass of ramet population,root-shoot ratio and density of ramet population decreased significantly with reduce oflight intensity; Under all light intensities, spatial pattern of ramets was mainlyrandomly distributed but it changed with different scales, with pattern intensity as:open space < forest edge < understory. Adaptation significance of the clonal architecture, the ramet population characteristics and the spatial pattern changing withdifferent environments was discussed according to these results.Clonal plants may take different adaptive strategies under different patches. Withpot culture, clonal integration and physiological parameters of F. orientalis underdifferent water contrasts were studied, and clonal integration under unilateralresources and reciprocal resources were also compared. The results suggested that,high water contrast improve the clonal integration of F. orientalis and increase thephotosynthesis of connected ramets. Oxidative and antioxidative system of F.orientalis also responded with changing water contrasts. According to cost-benefitanalysis, the drought-stressed ramets obtained benefits from the connectedwell-watered ramets, and as a whole, the clonal fragment could also get benefits.Growth of F. orientalis in homogeneous resources was better than that inheterogeneous resources, but the whole plant got more benefit through clonalintegration in heterogeneous resources than in homogeneous resources.Pot culture experiments were also used to study the adaptive strategies inutilizing heterogeneous resources by the plant populations from different altitudes.The results showed that, F. orientalis from alpine zones were shorter and lessexpanded with poorer clonal plasticity than those from middle mountains. F.orientalis from two different altitudes showed different responses to stolon severing,and as a whole, stolon severing had more influence on F. orientalis from alpine zones.In addition, F. orientalis from alpine zones exhibited higher division of labor, whichsuggested that clonal plants from different habitats develop their own adaptivemechanisms in their clonal integration and division of labor in response toenvironmental heterogeneity.

High-efficiency and low-cost hybrid nanomaterial as enhancing electrocatalyst: Spongelike AWN core/shell nanomaterial with hollow cavity

A high-efficiency and low-cost spongelike Au/Pt core/shell electrocatalyst with hollow cavity has been facilely obtained via a simple two-step wet chemical process. Hollow gold nanospheres were first synthesized via a modified galvanic replacement reaction between Co nanoparticles in situ produced and HAUCl(4). The as-prepared gold hollow spheres were employed as seeds to further grow spongelike Pt shell. It is found that the surface of this hybrid nanomaterial owns many Pt nanospikes, which form a spongelike nanostructure. All experimental data including scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis-near-infrared spectroscopy have been employed to characterize the obtained Au/Pt hybrid nanomaterial. The rapid development of fuel cell has inspired us to investigate the electrocatalytic properties for dioxygen and methanol of this novel hybrid nanomaterial. Spongelike hybrid nanomaterial mentioned here exhibits much higher catalytic activity for dioxygen reduction and methanol oxidation than the common Pt electrode.

Quantifying robustness and dissipation cost of yeast cell cycle network: The funneled energy landscape perspectives

We study the origin of robustness of yeast cell cycle cellular network through uncovering its underlying energy landscape. This is realized from the information of the steady-state probabilities by solving a discrete set of kinetic master equations for the network. We discovered that the potential landscape of yeast cell cycle network is funneled toward the global minimum, G1 state. The ratio of the energy gap between G1 and average versus roughness of the landscape termed as robustness ratio ( RR) becomes a quantitative measure of the robustness and stability for the network. The funneled landscape is quite robust against random perturbations from the inherent wiring or connections of the network. There exists a global phase transition between the more sensitive response or less self-degradation phase leading to underlying funneled global landscape with large RR, and insensitive response or more self-degradation phase leading to shallower underlying landscape of the network with small RR. Furthermore, we show that the more robust landscape also leads to less dissipation cost of the network. Least dissipation and robust landscape might be a realization of Darwinian principle of natural selection at cellular network level. It may provide an optimal criterion for network wiring connections and design.

A simple and low-cost airlift photobioreactor for microalgal mass culture

A simple, low-cost, and efficient airlift photobioreactor for microalgal mass culture was designed and developed. The reactor was made of Plexiglas, and composed of three major parts: outer tube, draft tube and air duct. The fluid-dynamic characteristics of the airlift reactor were studied. The system proved to be well suited to the mass cultivation of a marine microalga, Chlorella sp. In batch culture, the biomass volumetric output rate of 0.21 g l(-1) d(-1) was obtained at the superficial gas velocity of 4 mm s(-1) in the draft tube.

Robust Guaranteed Cost Control for Yaw Control of Helicopter

针对具有时变不确定性且不确定性界为椭球的线性系统提出了一种新的具有自适应机制的鲁棒保性能控制器设计方法。首先,引入一个具有可由自适应律在线调整的可调参数的目标模型,通过该参数来保证由目标模型与被控模型所获得的误差系统渐近稳定。结合保证目标模型稳定性的设计,最终形成保证闭环系统稳定且控制器增益仿射依赖于可调参数的鲁棒保性能跟踪控制器。应用于安装在试验平台上的小型直升机航向控制中,仿真试验表明了该方法的有效性。

The effect of the product cost factor on error handling in industrial robots

N.W. Hardy and M.H. Lee. The effect of the product cost factor on error handling in industrial robots. In Maria Gini, editor, Detecting and Resolving Errors in Manufacturing Systems. Papers from the 1994 AAAI Spring Symposium Series, pages 59-64, Menlo Park, CA, March 1994. The AAAI Press. Technical Report SS-94-04, ISBN 0-929280-60-1.

The cost of multiple large shareholders

Previous research argues that large non-controlling shareholders enhance firm value because they deter expropriation by the controlling shareholder. We propose that the conflicting incentives faced by large shareholders may induce a nonlinear relationship between the relative size of large shareholdings and firm value. Consistent with this prediction, we present evidence that there are costs of having a second (and third) largest shareholder, especially when the largest shareholdings are similar in size. Our results are robust to various relative size proxies, firm performance measures, model specifications, and potential endogeneity issues.

How Much Does It Cost to Provide Antiretroviral Therapy for HIV/AIDS in Africa?

Background: Many African countries are rapidly expanding HIV/AIDS treatment programs. Empirical information on the cost of delivering antiretroviral therapy (ART) for HIV/AIDS is needed for program planning and budgeting. Methods: We searched published and gray sources for estimates of the cost of providing ART in service delivery (non-research) settings in sub-Saharan Africa. Estimates were included if they were based on primary local data for input prices. Results: 17 eligible cost estimates were found. Of these, 10 were from South Africa. The cost per patient per year ranged from $396 to $2,761. It averaged approximately $850/patient/year in countries outside South Africa and $1,700/patient/year in South Africa. The most recent estimates for South Africa averaged $1,200/patient/year. Specific cost items included in the average cost per patient per year varied, making comparison across studies problematic. All estimates included the cost of antiretroviral drugs and laboratory tests, but many excluded the cost of inpatient care, treatment of opportunistic infections, and/or clinic infrastructure. Antiretroviral drugs comprised an average of one third of the cost of treatment in South Africa and one half to three quarters of the cost in other countries. Conclusions: There is very little empirical information available about the cost of providing antiretroviral therapy in non-research settings in Africa. Methods for estimating costs are inconsistent, and many estimates combine data drawn from disparate sources. Cost analysis should become a routine part of operational research on the treatment rollout in Africa.

Unicast Routing: Cost-Performance Tradeoffs

The objective of unicast routing is to find a path from a source to a destination. Conventional routing has been used mainly to provide connectivity. It lacks the ability to provide any kind of service guarantees and smart usage of network resources. Improving performance is possible by being aware of both traffic characteristics and current available resources. This paper surveys a range of routing solutions, which can be categorized depending on the degree of the awareness of the algorithm: (1) QoS/Constraint-based routing solutions are aware of traffic requirements of individual connection requests; (2) Traffic-aware routing solutions assume knowledge of the location of communicating ingress-egress pairs and possibly the traffic demands among them; (3) Routing solutions that are both QoS-aware as (1) and traffic-aware as (2); (4) Best-effort solutions are oblivious to both traffic and QoS requirements, but are adaptive only to current resource availability. The best performance can be achieved by having all possible knowledge so that while finding a path for an individual flow, one can make a smart choice among feasible paths to increase the chances of supporting future requests. However, this usually comes at the cost of increased complexity and decreased scalability. In this paper, we discuss such cost-performance tradeoffs by surveying proposed heuristic solutions and hybrid approaches.

On the Cost of Supporting Multihoming and Mobility

As the Internet has evolved and grown, an increasing number of nodes (hosts or autonomous systems) have become multihomed, i.e., a node is connected to more than one network. Mobility can be viewed as a special case of multihoming—as a node moves, it unsubscribes from one network and subscribes to another, which is akin to one interface becoming inactive and another active. The current Internet architecture has been facing significant challenges in effectively dealing with multihoming (and consequently mobility). The Recursive INternet Architecture (RINA) [1] was recently proposed as a clean-slate solution to the current problems of the Internet. In this paper, we perform an average-case cost analysis to compare the multihoming / mobility support of RINA, against that of other approaches such as LISP and MobileIP. We also validate our analysis using trace-driven simulation.

At what price? A cost-effectiveness analysis comparing trial of labour after previous caesarean versus elective repeat caesarean delivery

Background: Elective repeat caesarean delivery (ERCD) rates have been increasing worldwide, thus prompting obstetric discourse on the risks and benefits for the mother and infant. Yet, these increasing rates also have major economic implications for the health care system. Given the dearth of information on the cost-effectiveness related to mode of delivery, the aim of this paper was to perform an economic evaluation on the costs and short-term maternal health consequences associated with a trial of labour after one previous caesarean delivery compared with ERCD for low risk women in Ireland.Methods: Using a decision analytic model, a cost-effectiveness analysis (CEA) was performed where the measure of health gain was quality-adjusted life years (QALYs) over a six-week time horizon. A review of international literature was conducted to derive representative estimates of adverse maternal health outcomes following a trial of labour after caesarean (TOLAC) and ERCD. Delivery/procedure costs derived from primary data collection and combined both "bottom-up" and "top-down" costing estimations.Results: Maternal morbidities emerged in twice as many cases in the TOLAC group than the ERCD group. However, a TOLAC was found to be the most-effective method of delivery because it was substantially less expensive than ERCD ((sic)1,835.06 versus (sic)4,039.87 per women, respectively), and QALYs were modestly higher (0.84 versus 0.70). Our findings were supported by probabilistic sensitivity analysis.Conclusions: Clinicians need to be well informed of the benefits and risks of TOLAC among low risk women. Ideally, clinician-patient discourse would address differences in length of hospital stay and postpartum recovery time. While it is premature advocate a policy of TOLAC across maternity units, the results of the study prompt further analysis and repeat iterations, encouraging future studies to synthesis previous research and new and relevant evidence under a single comprehensive decision model.