Continuous-flow biodiesel production using slit-channel reactors

Slit-channel reactors are reactors whose active surface areas are orders of magnitude higher than those of micro-reactors but have low fabrication costs relative to micro-reactors. We successfully produced biodiesel with different degrees of conversion using homogeneous catalyst in the slit-channel reactor. The reactor performance shows that percent conversion of soybean oil to biodiesel increases with channel depth, as expected, due to more efficient mixing. Shallow slit-channels require short average residence times for complete product conversion. Present results show that the slit-channel reactor provides an improved performance over traditional batch reactors using homogeneous sodium alkoxide catalyst. It is aimed to couple the reactors with solid catalysts in converting soybean oil to biodiesel and implementation method is suggested. The cost advantages resulting from the ease of fabrication of slit-channel reactors over micro-reactors and how these factors relate to the oil conversion efficiency to biodiesel are briefly noted and discussed.     

Salvage after severe lower-extremity trauma: are the outcomes worth the means?

Advances in reconstructive surgery have allowed for impressive salvage after severe lower-extremity trauma but not without complications when compared with immediate below-knee amputation. Several amputation index scores have been developed to help predict successful salvage as defined by a viable rather than a functional extremity. The purpose of this study was to evaluate retrospectively the predictive value of the amputation index scores and to assess prospectively overall health status and specific dysfunction in successful limb salvage and primary and secondary amputation by administering standardized generic and specific outcomes questionnaires (Medical Outcomes Study 36-Item Short-Form Health Survey, Western Ontario and MacMaster Universities Osteoarthritis Index). A retrospective chart review identified 55 severe lower-extremity injuries (Gustilo Type IIIB and IIIC) over a 12-year period (1984 to 1996). Forty-six severe open tibial fractures in 45 patients underwent attempted salvage. All required soft-tissue coverage by either local or free flap or vascular repair for leg salvage. The attempted-salvage group was subdivided into successful salvage and secondary amputation. The other nine patients underwent a primary amputation. There were no statistically significant differences in terms of patient demographics or other injuries (Injury Severity Score) in the three groups. Forty-eight of 54 patients with an average 5-year follow-up completed a validated generic and specific outcomes health questionnaire. In the attempted-salvage group, 89 percent of patients had a successful salvage and 11 percent came to a secondary amputation. The amputation index scores correctly predicted an amputation in 32 percent of patients. The magnitude of the amputation index scores did not correlate with the physical outcomes scores and were not found to add any significant value of information to the surgeon's decision making. Patients undergoing primary and secondary amputation had a worse physical outcomes score (28 versus 38) than successful salvage (p < 0.007). Even so, the SF-36 (physical component score) outcomes score for this group of injured extremities, regardless as to whether salvaged or amputated, was as low as or lower than that of many serious medical illnesses, suggesting that severe lower-extremity trauma impairs health as much as or more than being seriously ill. The mental component score in this group was comparable to that of a healthy population (49 versus 50), which implies the disability is primarily physical rather than psychological. Ninety-two percent of patients preferred their salvaged leg to an amputation at any stage of their injury, and none would have preferred a primary amputation.     

Impact of Financial Liberalization on Banking Sectors Performance from Central and Eastern European Countries

In this paper we analyse the impact of financial liberalization and reforms on the banking performance in 17 countries from CEE for the period 2004–2008 using a two-stage empirical model that involves estimating bank performance in the first stage and assessing its determinants in the second one. From our analysis it results that banks from CEE countries with higher level of liberalization and openness are able to increase cost efficiency and eventually to offer cheaper services to clients. Banks from non-member EU countries are less cost efficient but experienced much higher total productivity growth level, and large sized banks are much more cost efficient than medium and small banks, while small sized banks show the highest growth in terms of productivity.     

旅游地生态效率测度的SBM-DEA模型及实证分析

旅游地是典型的人地关系相互作用的特殊区域,旅游地的生态效率研究是其制定与实施包容性、持续性发展政策与措施的基础。采用基于时间序列、包含非期望产出的SBM-DEA模型方法,构建旅游地生态效率测度模型及评价指标体系,以黄山风景区为例,利用1981—2014年的投入产出数据,测度旅游地复合系统的生态效率,分析其演化特征和阶段,并利用Tobit回归模型对其影响因素进行实证检验。结果表明:(1)34年来,黄山风景区旅游生态效率(综合效率)不断提升,且具较大发展潜力,在分解效率中,技术效率较高,规模效率次之,规模效率是决定综合效率的关键因素;(2)旅游生态效率的演化经历了初期低效、快速成长、成熟高效、下行风险四个阶段,不同阶段效率的特征不同,影响因素也存在差异;(3)旅游生态效率完成了由规模报酬递增向递减的过渡,资源要素的投入冗余已成为现阶段阻碍生态效率的进一步提高的关键因素;(4)旅游发展水平、产业结构和技术水平对生态效率产生显著的正向影响,投资水平产生显著的负向影响,以废弃物末端治理为表征的环保规制对生态效率的提升作用并不显著。文章最后提出,在山岳型风景区发展初期,应尽可能扩大资源要素投入规模,进入成熟阶段后,则转向逐渐控制投入规模,改善技术能力和资源配置能力,摒弃过度依靠资源消耗和环境污染的粗放式发展模式,走精细化、可持续的发展道路。     

An Algorithm for Testing the Efficient Market Hypothesis

The objective of this research is to examine the efficiency of EUR/USD market through the application of a trading system. The system uses a genetic algorithm based on technical analysis indicators such as Exponential Moving Average (EMA), Moving Average Convergence Divergence (MACD), Relative Strength Index (RSI) and Filter that gives buying and selling recommendations to investors. The algorithm optimizes the strategies by dynamically searching for parameters that improve profitability in the training period. The best sets of rules are then applied on the testing period. The results show inconsistency in finding a set of trading rules that performs well in both periods. Strategies that achieve very good returns in the training period show difficulty in returning positive results in the testing period, this being consistent with the efficient market hypothesis (EMH).     

Peer assessment in large undergraduate classes: an evaluation of a procedure for marking laboratory reports and a review of related practices

This study provides evidence that peer marking can be a reliable tool for assessing laboratory reports in large cohorts. It was conducted over a 4-yr period with first-year undergraduates (～180 students/cohort) taking a mammalian physiology course, but the procedure adopted would be applicable to any other laboratory-based discipline. The process was found to be efficient in staff time, enabling a summative practical report to be marked in <1 h (<5% of the time that had previously been required for staff marking), facilitating rapid feedback to students on their performance. When samples of the peer-assessed reports were marked by a single member of staff, there was excellent correlation between peer and staff marks (r = 0.96-0.98), although peer-awarded marks exceeded staff marks by an average of 2.5-3.0%. The validity of peer marking was independent of both the sex of the marker and the staff score awarded to the marker for the same piece of work. Feedback from students was largely positive; they reported that the procedure adopted was effective in increasing their understanding of the underlying physiology and contributed to their understanding of best practice in presenting a laboratory report. Seventy percent of students agreed that it was acceptable for peer assessment to contribute a small (up to 5%) component of the overall mark for the course. The results are discussed in relation to other reports of peer marking, particularly when used to assess an academic product or process in a scientific discipline.     

Effect of Veau-Wardill-Kilner type of cleft palate repair on long-term midfacial growth

There is a common concern that the Veau-Wardill-Kilner type of cleft palate repair causes extensive denudation of the palate, resulting in inhibition of maxillary growth. The evidence for this belief is equivocal in the literature. The authors present some long-term results of this technique from a pure sample of nonsyndromic complete unilateral cleft lip and palate patients operated on by a single intermediate-volume cleft surgeon over a period of 25 years. Twenty-five patients, all born between 1977 and 1989, met the above inclusion criteria. Their age at the time of collection of study models and cephalograms was 9 to 17 years (average, 12 years). Midfacial growth was studied using 12-year dental models and lateral cephalograms taken before definitive orthodontic treatment. These were evaluated using the GOSLON Yardstick and digital cephalometric analysis. The final GOSLON results show that 72 percent of the patients had a good or satisfactory outcome, with a GOSLON score of 1, 2, or 3, and only 28 percent ended with a poor score of 4 or 5. The poor sensitivity of cephalometrics in discerning statistically significant differences was highlighted by the huge overlaps observed in the 95 percent confidence interval graph of mean sella-nasion-subspinale angle (S-N-A) values when comparing the results of the Eurocleft centers with those of the authors' center. The results suggest that satisfactory long-term midfacial growth can be obtained with Veau-Wardill-Kilner cleft palate repair.     

促进植物高效遗传转化的发育调节因子及其在玉米中的应用进展*

高效遗传转化技术体系的建立对植物功能基因组学研究和作物新品种的培育均具有促进作用,目前,再生效率低下是限制许多植物高效遗传转化体系建立的主要技术屏障之一。随着对植物分生组织和体细胞胚形成过程研究的深入,鉴定到了一些关键调控基因,统称为发育调节因子。发育调节因子应用于植物遗传转化后,可以有效改善植物分生组织诱导和再生能力,为提高遗传转化效率提供了重要机遇。综述了7类发育调节因子在提高植物遗传转化效率中的研究进展,重点介绍了其中3类在促进玉米遗传转化中的应用,最后展望了建立植物高效遗传转化体系的发展方向。     

Growth of microalgae Botryococcus sp. in domestic wastewater and application of statistical analysis for the optimization of flocculation using alum and chitosan

Microalga biomass has been recognized as a sustainable bio-product to replace terrestrial biomass in biofuel production. The microalga industry has high operating costs, specifically on harvesting and biomass recovery. Therefore, the development of an efficient harvesting method is crucial to the minimization of production cost. A statistical analysis through response surface methodology was used to investigate the optimization of harvesting efficiency using alum and chitosan as a coagulant. Growth rate and biomass productivity were also determined. This research revealed that the harvesting efficiency using alum was 99.3%, with optimum dosage and pH of 177.74 mg L^?1 and 8.24, respectively. Chitosan achieved 94.2% biomass recovery at an optimal dosage of 169.95 mg L^?1 at pH of 12. Moreover, Botryococcus sp. achieved the maximum growth of 0.7551 µ_max d^?1, with an average total biomass productivity of 9.81 mg L^?1?d^?1 in domestic wastewater. Overall, this study shows that both alum and chitosan coagulants have great potential for efficient microalgal biomass recovery. It suggests that domestic wastewater as a potential growth medium for the large-scale production of microalga biomass.     

江苏农业种质资源平台运行管理信息系统建设

为促进农业种质资源开放共享,江苏省于2005年启动农业种质资源保护与利用平台建设,经过十多年的努力,初步建成了“四位一体”“库圃结合”的农业种质资源保护与利用体系,涵盖农作物、林木、水产和家养动物4大类共计30个省级种质库(圃),有力地支撑了江苏现代农业品种创新与产业发展.由于平台跨学科、跨行业建设,种质库(圃)遍布全...     

Acoustic signalling in palaeotropical bushcrickets (Orthoptera: Tettigonioidea: Pseudophyllidae): does predation pressure by eavesdropping enemies differ in the Palaeo- and Neotropics?

When producing its calling song, a male bushcricket exposes itself to predators which use this sound for localization. Male signalling therefore has to be a compromise between attracting females and avoiding predators. In this study, the calling song structure of six Malaysian bushcricket species of the family Pseudophyllidae was examined. The lowest frequency of longdistance signals in insects yet discovered is the 600 Hz produced by Tympanophyllum arcufolium. The peak frequency of all six species and three additional species, from which only handling sounds were examined, was below 12 kHz. The duty cycle (that period of time spent signalling) was low, between one and five percent in four species and more than 20 percent in the remaining two species, typical for species which rely on camouflage. None of the various types of bat avoidance behaviour observed in the neotropical Pseudophyllidae was found in the Malaysian species. This difference is discussed in regard to the possibility of different predation pressures in the Palaeo- and Neotropics.     

Energy Efficiency and Structural Change in the Netherlands, 1980–1995

International agreement has been reached to reduce greenhouse gas emissions worldwide. One important way of decoupling CO₂ emissions from economic growth is by introducing technical measures to improve energy efficiency. In this article, we assess the influence of developments in energy efficiency and economic structure on the total primary energy consumption in the Netherlands over the period 1980– 1995. We find a distinct decoupling of the economic growth and energy consumption of 1.5% per year in the 15-year analysis period. We measure (technical) changes in energy efficiency by changes in the energy consumption per physical unit of production or activity. The aggregate rate of (technical) energy-efficiency improvement was 1.4% per year over the period 1980–1995. The use of physical production indicators makes it possible to measure energy-efficiency developments without detailed surveys at a very low level of aggregation. When we look at economic structural changes over this period, we find that (i) no substantial shift took place at the level of the economic sectors that we distinguish; (ii) the most energy intensive subsectors grew much faster than the total economy; and (iii) at the subsector level, on average, a sizable decoupling of physical production and value added occurred. We conclude that structural changes, that is, changes in the composition of the economy, did not lead to a net decrease in the energy intensity of the Netherlands over the period 1980–1995.     

Comparison between PIT and radio telemetry to evaluate winter habitat use and activity patterns of juvenile Atlantic salmon and brown trout

Winter habitat use and activity patterns of juvenile Atlantic salmon and brown trout were analysed in a comparative study between Passive Integrated Transponder (PIT) technology, radio telemetry and underwater observation by snorkelling. Two study periods were conducted in Stoney River, Newfoundland, Canada. During Study period I, 49 juvenile Atlantic salmon (fork length: 11.0–18.0 cm) and 7 brown trout (11.0–17.3 cm) were tagged with PIT tags and/or radio transmitters in late winter of 2004. During Study period II, 18 juvenile Atlantic salmon (fork length: 12.0–18.4 cm) and 23 brown trout (10.9–20.8 cm) were tagged and tracked twice a day at 10:00 h and 22:00 h on five consecutive days in late winter of 2005. From the 56 fish released during Study period I, on average 19.6 ± 6.0% of the PIT tagged fish and 99.3 ± 2.2% of the radio tagged fish were relocated during any given survey. Over the Study period II, 39% of fish emigrated from the study site. PIT technology had an efficiency of 39.2 ± 14.1% to detect the remaining fish. In contrast, radio telemetry relocated on average 96.9 ± 6.5% of the tagged fish whereas by snorkelling on average only 4.1 ± 5.6% of the tagged fish were observed. PIT telemetry may however be more efficient in smaller, less heterogeneous streams. The advantage of PIT technology over radio telemetry is clearly that it is relatively less costly permitting higher numbers of individuals to be tagged and there is no limit in the operational life of the transponder. In winter, juvenile salmonids preferred low flow velocity and no preferences were observed for any specific water depth over the range of available water depths. Fish selected preferentially boulder habitat over other substrates in the environment. Habitat utilisation did not differ between day and night. The use of winter preference indices may be important for future habitat modelling.     

国家中心城市交通运输业碳排放效率研究

为改善交通运输业碳排放效率促进城市低碳经济发展,以在区域发展中发挥引领作用的九个国家中心城市为研究对象,运用包含非期望产出的Super-SBM模型和Malmquist-Luenberger生产率指数,从静态和动态两个角度对研究区2005—2016年交通运输业碳排放效率进行了测算,并进一步分析了碳排放效率变化的影响因素....     

Stochastic frontier model approach for measuring stock market efficiency with different distributions

The stock market is considered essential for economic growth and expected to contribute to improved productivity. An efficient pricing mechanism of the stock market can be a driving force for channeling savings into profitable investments and thus facilitating optimal allocation of capital. This study investigated the technical efficiency of selected groups of companies of Bangladesh Stock Market that is the Dhaka Stock Exchange (DSE) market, using the stochastic frontier production function approach. For this, the authors considered the Cobb-Douglas Stochastic frontier in which the technical inefficiency effects are defined by a model with two distributional assumptions. Truncated normal and half-normal distributions were used in the model and both time-variant and time-invariant inefficiency effects were estimated. The results reveal that technical efficiency decreased gradually over the reference period and that truncated normal distribution is preferable to half-normal distribution for technical inefficiency effects. The value of technical efficiency was high for the investment group and low for the bank group, as compared with other groups in the DSE market for both distributions in time-varying environment whereas it was high for the investment group but low for the ceramic group as compared with other groups in the DSE market for both distributions in time-invariant situation.     

Economics of technical efficiency in white honey production: Using stochastic frontier production function

This study estimates and compares technical efficiency levels among beekeeping projects with various production capacities using a sample drawn from Fayoum Governorate in Egypt. The study also compares among beekeeping’s most important economic indicators, estimates the optimum production amount, and investigates why technical efficiency in Egyptian beekeeping is declining. We conclude that the average cost to produce one ton of honey decreases when production capacity increases. Furthermore, the average total, net return, and return on investment of one Egyptian pound increases when production capacity increases. Moreover, the results of a stochastic frontier production function indicate an increased return to scale. Finally, the results of maximum likelihood estimation show that technical inefficiency helps explain the deviation of actual from optimal production amounts.     

Effects of different-shaped tissue expanders on transluminal pressure, oxygen tension, histopathologic changes, and skin expansion in pigs

This study, performed on domestic pigs, was designed to show whether the shape and size of a tissue expander influences the amount of surface area increase. When a defect is irregular, a larger custom-fitted implant is more efficient than several smaller expanders. Oval implants gained 5 percent more skin using 50 percent less time and almost 20 percent less intraluminal pressure, while U-shaped implants yield 2.2 percent more skin in 10 percent less time with 35 to 50 percent less pressure when compared with several smaller implants covering the same surface area. Transcutaneous TpO2 measurements and histologic evaluation revealed no significant difference between all implant shapes. These results show that less time, pressure, and volume are needed in a larger implant to gain the same surface area as would be attained from several smaller implants, thus sparing the patient more discomfort, trauma, and risk of infection by reducing the number of filling domes and hence the number of fillings.     

Prevention of pressure sores by identifying patients at risk.

The risk of pressure sores developing in patients admitted with acute conditions was assessed by a simple risk score system based on age, reduced mobility, incontinence, pronounced emaciation, redness over bony prominences, unconsciousness, dehydration, and paralysis in a prospective clinical study. During seven months in 1977, 600 of 3571 patients were classified as at risk. Of these 35 (5.8%) developed sores compared with five (0.2%) of those not at risk. The results of this study compared with those over the same period in 1976 show that close observation of at-risk patients and early detection of pressure sores prevents their development.     

Longitudinal study of body weight changes in children: who is gaining and who is losing weight

Cross-sectional studies have reported significant temporal increases in prevalence of childhood obesity in both genders and various racial groups, but recently the rise has subsided. Childhood obesity prevention trials suggest that, on average, overweight/obese children lose body weight and nonoverweight children gain weight. This investigation tested the hypothesis that overweight children lose body weight/fat and nonoverweight children gain body weight/fat using a longitudinal research design that did not include an obesity prevention program. The participants were 451 children in 4th to 6th grades at baseline. Height, weight, and body fat were measured at month 0 and month 28. Each child's BMI percentile score was calculated specific for their age, gender and height. Higher BMI percentile scores and percent body fat at baseline were associated with larger decreases in BMI and percent body fat after 28 months. The BMI percentile mean for African-American girls increased whereas BMI percentile means for white boys and girls and African-American boys were stable over the 28-month study period. Estimates of obesity and overweight prevalence were stable because incidence and remission were similar. These findings support the hypothesis that overweight children tend to lose body weight and nonoverweight children tend to gain body weight.     

Effect of iron media on the treatment of domestic wastewater to enhance nutrient removal efficiency

The purpose of this study was the development of an alternative coagulant supply device intended to replace the conventional chemical dosing system used for phosphorus removal. Bench-scale, multi-stage, upflow anaerobic fixed bed reactors (UAFBRs) were packed with iron nuts and domestic wastewater was fed continuously to enhance microbially influenced corrosion under anaerobic conditions. Total iron concentration in the effluent varied between 7.8 and 13.0 mg/l over the 120-day testing period ensuring sustained corrosion of iron in the reactors. A hybrid process consisting of the UAFBRs and an anoxic/oxic (A/O) process was tested to investigate the removal efficiencies of organic substances, nitrogen and phosphorus from domestic wastewater. Two types of systems were operated in parallel with different return sludge ratios. One was the hybrid process and the other was the A/O process. In comparing the hybrid process with the A/O process with respect to phosphorus removal efficiency, the performance of the hybrid process was much better than that of the A/O process alone, since phosphate ions in wastewater combined with iron cations from UAFBR. Nitrogen removal efficiency of the hybrid process was lower than that of the A/O process because the chemical oxygen demand/total Kjeldal nitrogen ratio of influent to the anoxic and aeration tank was decreased as organics in the domestic wastewater were removed by the UAFBR.