首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
An investigation was made to determine the feasibility of using the fiber of Rux (Calotropis gigantea), a common wild plant in Thailand, to make textile fabric. It was found that a mixture of Rux with cotton, as well as a mixture of Rux with synthetic fibers such as rayon or polyester, could be used to make textile fabrics of reasonable quality. As Rux is a weed growing everywhere without requirements for fertilizers and pesticides, the adoption of Rux as a source of fiber for the textile industry could bring large areas of presently unused marginal land under cultivation and might reduce the energy input to farming. Such a development could lead to a higher net income for farmers, as well as creating a new cottage industry to provide another source of income for the rural people of the third world.  相似文献   

2.
测定了内蒙古自治区锡盟镶黄旗15个不同地点水样中的NO^-2含量。实验结果显示,15个地点水样中NO^-2的含量相差很大,大致分为A、B、C3组,其平均值分别为0.186、0.640、3.850μg/ml。  相似文献   

3.
Noroviruses are responsible for approximately 44 % of outbreaks involving dairy products for which causative agents are reported. Recovery of viruses from milk and dairy products is a difficult task. The role of different components of milk in the recovery of viral RNA was evaluated in this study. Four model milk formulations (A–D) were prepared by mixing different combinations of lactose, whey protein, casein, and fat in water. Each model formulation was spiked with five concentrations of bacteriophage MS2. The phenol-guanidine thiocyanate-chloroform protocol was used for extracting viral RNA from the model milk formulations and then extracted RNA was measured by a nanodrop spectrophotometer in ng/μl. The results showed that casein and whey protein had the highest negative impact on RNA yield, especially when the number of MS2 was less than 1.3 pfu/ml. The highest RNA recovery was obtained from the model milk formulation containing all four components; lactose, whey protein, casein, and fat. The amount of extracted RNA was closely correlated with the dry matter content of each formulation and the spiked concentration of coliphage using response surface modeling (R2:0.93). It was determined that milk fat is the most effective component in facilitating RNA extraction and the highest RNA yield can be achieved via elimination of whey protein and casein from milk by centrifugation at 40,000×g for 60 min. To achieve the highest viral RNA recovery efficiency by the proposed method, milk fat must be recombined with the supernatant of the centrifuged sample and then homogenized before performing the extraction protocol.  相似文献   

4.
以云南红花油茶当年生半木质化的春季枝条为试验材料,用不同植物生根激素、营养液处理材料后进行扦插繁殖试验,比较不同生根激素和营养液对扦插枝条生根成活的影响。结果表明:使云南红花油茶生根成活率较高的植物激素组合是NAA(500mg/L)+KT(100mg/L),生根率达65%;而较适宜扦插枝条生根成活的营养液配方是MV,生根率达到了80%。  相似文献   

5.
The environmental concern and development issues regarding packaging has for 20 years to a high extent been on packaging when it has become waste. To reduce the environmental impact from the whole food packaging system it is also important to develop the packaging’s ability to reduce food waste. In some cases it may be necessary to increase the environmental impact of packaging in order to reduce food waste. In this paper, the environmental impact of packaging and food losses and the balance between the two has been examined for five different food items. The results show that packaging’s that reduce food waste can be an important tool to reduce the total environmental impact, even if there is an increase in impact from the packaging itself. This is especially true for food items where the environmental impact of the food is high relative the packaging, for example cheese, and for food items with high losses, for example bread. It is important to analyse the risk of increasing food losses when packaging design changes, for example, when the aim is less packaging material, which is the main intention of the packaging and packaging waste directive of the European Union.  相似文献   

6.
1995-2015年江苏省土地利用功能转型特征及其协调性分析   总被引:13,自引:3,他引:10  
土地利用功能转型可实现土地利用功能协调,是实施区域可持续发展的重要路径。从功能协调角度构建土地利用功能转型分析框架,利用江苏省1995年、2000年、2005年、2010年和2015年5期遥感影像及相关资源利用和社会经济数据,构建三级土地利用功能评价体系,以县域为评价单元,通过三角模型和空间相关分析等方法,定量解析江苏省土地利用功能时空演变特征及其与土地可持续利用目标的协调状况。研究结果显示:(1)研究期内,江苏省土地利用功能总水平提升减慢,其中生产、生活功能不同程度提升,生态功能明显下降。(2)生产、生活功能空间集聚不突出,生态功能的热点、冷点区域呈“Y”型集聚分布。(3)不同功能区功能协调性态势不一,重点开发区和限制开发区可持续发展态势总体良好,优化开发区可持续发展程度较弱并持续恶化。建议江苏省在落实发展蓝图和空间规划的过程中,应优先推进苏南现代化示范区建设,重点实施重点开发区生活功能转型、Ⅰ类限制开发区生产功能转型策略,并严格落实禁止开发区的生态保护责任等差别化管理策略。  相似文献   

7.
The importance of land use evaluation has recently been recognised in Life Cycle Assessment (LCA). Even so, there is still a considerable lack of definition, particularly concerning what parameters should be considered and – as a result – what particular methodology should be used. This paper presents a review of the different methods proposed for assessing the environmental impact of land use. The methodology is specially developed for assessing endpoint categories such as biodiversity and life support systems. We evaluated the environmental impact associated with protected horticulture and compared it with other forms of human activity. The study was carried out in the area of El Maresme. This has traditionally been an agricultural area, although it is now under heavy pressure from urban and industrial developments due to its proximity to Barcelona. On the basis of the results obtained in the case study, it was demonstrated that agricultural uses ranked at the same level or slightly below those of urban uses, and that both uses clearly scored lower than forest uses, from the point of view of biodiversity. When a productivity indicator was used, agricultural use registered a smaller environmental impact than urban use, but larger than for forestry. Finally, we discuss the problems and limitations encountered when these methods were applied in our case study.  相似文献   

8.
Norovirus (NoV) is recognized as the most common cause of foodborne outbreaks. In 2014, an outbreak of acute gastroenteritis occurred on a cruise ship in Brazil, and NoV became the suspected etiology. Here we present the molecular identification of the NoV strains and the use of sequence analysis to determine modes of virus transmission. Food (cream cheese, tuna salad, grilled fish, orange mousse, and vegetables soup) and clinical samples were analyzed by ELISA, conventional RT-PCR, qRT-PCR, and sequencing. Genogroup GII NoV was identified by ELISA and conventional RT-PCR in fecal samples from 5 of 12 patients tested (41.7%), and in the orange mousse food sample by conventional RT-PCR and qRT-PCR. Two fecal GII NoV samples and the orange mousse GII NoV sample were successfully genotyped as GII.Pe (ORF 1), revealed 98.0–98.8% identities among them, and shared phylogenetically distinct cluster. Establishing the source of a NoV outbreak can be a challenging task. In this report, the molecular analysis of the partial RdRp NoV gene provided a powerful tool for genotyping (GII.Pe) and tracking of outbreak-related samples. In addition, the same fast and simple extraction methods applied to clinical samples could be successfully used for complex food matrices, and have the potential to be introduced in routine laboratories for screening foods for presence of NoV.  相似文献   

9.
Single-use medical devices have been under close scrutiny for several years, especially the choice of plastic materials. Many different requirements such as medical safety, treatment functionality and efficiency, environmental performance, etc. have to be fulfilled. Today, the most commonly used materials for hydrophilic urinary catheters are polyvinylchloride (PVC) and thermoplastic polyurethane (TPU). In this research study, these two materials' environmental performance was evaluated. In light of the knowledge gained in that study a new plastic material for use in urinary catheters was developed. The aim of the development of this new material was to design a high performance material with superior environmental performance. The newly developed plastic material is a polyolefin-based elastomer. The ecological environmental performance of the new material was evaluated and compared to the existing plastic materials. The study focused exclusively on the choice of plastic materials and their ecological environmental performance.The analysis has been performed using a system perspective and a life cycle assessment (LCA) methodology. The functional unit has been set to the treatment of one patient during one year. The results from the LCA models have been presented both in terms of direct inventory data, such as energy use and formed emissions, and in terms of the results from four different impact assessment methods. Analysis of the results based on direct inventory data, i.e. common inventory results such as energy resource uses and emissions of CO2, NOx and SO2 show an overall better environmental performance for the new polyolefin-based elastomer compared to the existing PVC and TPU plastic materials. The normalization and weighting steps in the analyzes have indicated the importance of energy resource uses and global warming as indicator for the environmental performance even if other impact categories also can play a role. In the environmental impact assessment, the polyolefin-based elastomer showed a clearly better environmental performance than the TPU material. Compared to PVC plastic material the new polyolefin-based elastomer showed an almost equivalent environmental performance. This can be mainly explained by the different materials' energy use. The new material has thus also shown to be an environmentally good alternative to PVC if a PVC-free material is requested. Basing the plastic formula, on simple bulk plastics with low energy use in the production of single-use medical devices, has been shown to be a successful method of producing high quality products with superior environmental performance.  相似文献   

10.
An operational method to include land use impacts in LCA has been developed. The aim was to base the approach on a scientific framework and to use scientific data to arrive at indicator scores. This has led to a first set of rough impact score data per type of land use on a global level, for two indicators. Remaining subjective elements are related to the restrictions of the approach: only two indicators are chosen as a basis for expressing land use impacts (vascular plant species diversity and free net primary biomass production), a reference state had to be included to incorporate regional differences, and for biodiversity the measure is relative to the local background biodiversity, leading to relatively low sensitivities to changes. Finally, land use impacts are considered to be proportional to the area which is a common understanding in LCA, but not always agreed upon. It is clear that this operationalisation is at present only in its teens.  相似文献   

11.
沈阳市新农村生活垃圾调查及治理对策研究   总被引:1,自引:0,他引:1  
沈阳农村人口众多,生活垃圾数量巨大,却没有很好地得到处理,带来了一系列问题,针对这些问题,通过对沈阳市典型五个农村生活垃圾组分、性质的采样调查、分析、化验,可知农村平房区和楼房区村民产生的生活垃圾成分含量差别很大,主要与居民的燃料结构有关。生活垃圾的热值、含水率、灰分也有差异,主要因素是垃圾成分的差异。明确了垃圾成分,参阅“穿越环境高山理论”对照发达国家的发展历程,提出了沈阳市农村生活垃圾处理方法与对策。  相似文献   

12.
石羊河流域生态环境的变迁与水资源利用对策   总被引:2,自引:0,他引:2  
本文对石羊河流域水资源开发利用中存在的问题提出新观点,认为:①人们以往只注意强化地表水控制,削弱了天然地下水库的调节作用;②只注意农田用水,忽视了绿洲生态用水;⑧目前采用的落后灌溉方式造成水资源的严重浪费。针对这些问题,本文提出石羊河流域水资源管理综合决策方案,建立多目标管理决策模型,把该流域划分为16个管理亚区,以绿洲农田生态系统和植被生态系统的需水量为决策变量,对经济发展、开发水资源投资、生态环填改善等方面的9个目标作综合考虑。通过模型的模拟运转,展示了该流域生态环境日趋恶化的状况可以得到有效的控制。  相似文献   

13.
关于生态用水研究的讨论   总被引:27,自引:2,他引:25  
十几年生态用水研究进展,其概念从自然地理平衡说法到生态系统稳定说法,至今未明确统一。按生态用水概念的内涵,将生态、环境、生态环境与用水、需水、耗水6个词的多样组合归纳为生态需水和生态用水两个词。地带性植被生态用水是生态用水研究的基础,可为生态保护和植被建设提供依据和目标。建议生态用水概念定义为:维持各类生态系统正常发育与相对稳定所必需消耗和现存的水称为生态用水。  相似文献   

14.
燃气红外干化污泥对肥效及农用安全性的影响   总被引:1,自引:0,他引:1  
自行研制的以煤气为能源的污泥干化中试成套设备,干化城市污水处理厂污泥,并对污泥肥效、病原体杀灭效果以及重金属含量的变化进行了研究,结果表明,经该套设备处理后,污泥的肥效保持不变,重金属含量也未发生变化,而污泥中的大肠杆菌和蛔虫卵全部被杀灭。处理后的污泥可在我国中、碱性土壤上作农肥使用。  相似文献   

15.
In recent years, power ultrasound has taken a significant place in chemical and physical activities of the process industries as an effective and non-polluting method of activation. Oil in water emulsions known as fatliquors are used for the lubrication of tanned leather fibres to get softness and also to improve the strength properties. In the present study, ultrasound has been used as a tool for the preparation of fatliquor emulsion for application in leather fatliquoring process. An emulsion is a fine dispersion of one liquid in another liquid. Sulphation is one of the common methods followed to prepare fatliquor emulsion where sulphuric acid is used. In the conventional process, emulsifying agent is also added to increase the stability of oil in water emulsions. The emulsifying agents generally used are chemicals or metal soaps. The potential use of ultrasound in the preparation of stable oil in water emulsions dispensing with sulphation process and with the minimum use of emulsifying agent has been studied and reported in this paper. This process enjoys the benefit of less pollution load in the form of chemical entities. The studies included the effect of process parameters such as ultrasonic output power and amount of oil used. Fatliquor emulsion prepared using ultrasound has been applied in leather fatliquoring process and the strength properties of the leathers were assessed. Emulsion particle size, which is another important parameter for diffusion through leather, has been measured using Laser Diffraction Technique. The stability of the ultrasonically prepared fatliquor emulsion has been found to be good. The results indicate that ultrasound could be effectively utilized in the preparation of non-ionic fatliquor emulsion eliminating sulphuric acid and impart required properties in leather.  相似文献   

16.
资源产出率是科学评价循环经济发展水平的核心指标,国家及部分省已开展了相关研究.然而在市域及县域层面,资源产出率核算还缺乏统一的方法,制约了其应用.选择鹤壁市作为典型研究区域,基于物质流分析方法,重点探讨了采用测算方法对区域资源产出率进行核算.研究结果表明,测算方法利用常规公开统计数据,对市县域层面资源产出率进行核算基本可行,可为市县域资源产出率核算提供参考.  相似文献   

17.
Focus on eco-friendly processing techniques makes vegetable tanning a viable option in leather processing and establishes the subsequent need for the more efficient methods of extraction in tannin manufacture. Application of ultrasound has been tried in the extraction of tannins from myrobalan nuts in order to improve the extraction efficiency, to perform the extraction under milder process conditions and to reduce the process time. The influence of process parameters such as ultrasonic output power, time and temperature has been studied. Scale-up trials and the use of ultrasound in pulse mode have also been attempted. The results show that a three- to fivefold improvement is possible with ultrasonic output from 20 to 100 W. Extraction efficiency has been calculated from the maximum extractable materials from myrobalan nuts. Extraction efficiency is found to be 90% for ultrasound, 100 W without external heating as compared to 77% for control process at 70 °C for 4 h. Therefore, ultrasound could be employed even dispensing with provision for temperature controls. The use of ultrasound in pulse mode offered 70% extraction efficiency of continuous mode. Scale-up trials indicate that there exists an optimum ultrasonic output power depending on the amount of nuts used, to achieve better extraction efficiency. The effectiveness of ultrasonically extracted tannin solution has also been tested in the tanning process for its applicability. The degree of tanning efficacy has been assessed by shrinkage temperature measurement. The results indicate that ultrasonically extracted tannin solution is suitable for tanning process. Therefore, application of ultrasound in tannin extract manufacture is a viable option with added advantages.  相似文献   

18.
Biochar is a carbon-neutral or even carbon-negative material produced through thermal decomposition of plant- and animal-based biomass under oxygen-limited conditions. Recently, there has been an increasing interest in the application of biochar as an adsorbent, soil ameliorant and climate mitigation approach in many types of applications. Metal-contaminated soil remediation using biochar has been intensively investigated in small-scale and pilot-scale trials with obtained beneficial results and multifaceted effects. But so far, the study and application of biochar in contaminated sediment management has been very limited, and this is also a worldwide problem. Nonetheless, there is reason to believe that the same multiple benefits can also be realized with these sediments due to similar mechanisms for stabilizing contaminants. This paper provides a review on current biochar properties and its use as a sorbent/amendment for metal-contaminated soil/sediment remediation and its effect on plant growth, fauna habits as well as microorganism communities. In addition, the use of biochar as a potential strategy for contaminated sediment management is also discussed, especially as regards in-situ planning. Finally, we highlight the possibility of biochar application as an effective amendment and propose further research directions to ensure the safe and sustainable use of biochar as an amendment for remediation of contaminated soil and sediment.  相似文献   

19.
Extracellular polymeric substances(EPS) produced by microorganisms represent biological macromolecules with unfathomable potentials and they are required to be explored further for their potential application as a bioflocculant in various wastewater sludge treatment. Although several studies already exist on biosynthetic pathways of different classical biopolymers like alginate and xanthan, no dedicated studies are available for EPS in sludge. This review highlights the EPS composition, functionality, and biodegradability for its potential use as a carbon source for production of other metabolites. Furthermore, the effect of various extraction methods(physical and chemical) on compositional, structural, physical and functional properties of microbial EPS has been addressed. The vital knowledge of the effect of extraction method on various important attributes of EPS can help to choose the suitable extraction method depending upon the intended use of EPS. The possible use of different molecular biological techniques for enhanced production of desired EPS was summarized.  相似文献   

20.
The relationship between economy and environmental impacts has been an essential topic in the discussion on environmental problems for a long time. From the 1990s, this relationship has gained a position in environmental policy as well. De-coupling the use of natural resources from economic growth has been set as one of the policy goals in the sixth Environmental Action Programme by the European Commission. In the scientific discussion, the concept of environmental Kuznets curve deals closely with the de-coupling or de-linking phenomenon. Aggregated material flows, on the other hand, have often been considered as a macro-level proxy of environmental degradation. Different methods or approaches have been designed for “sustainability” or “carrying capacity” evaluation as well. The objective of this article is (i) to discuss the possibilities and limitations of using environmental and economic indicators in the sustainability analysis at the macro level, (ii) to present a theoretical framework for the linking analysis including a classification of the degrees of de-linking/re-linking environmental impacts from/to economic growth, and (iii) to give an empirical example by using indicators of direct material flows as a proxy of environmental degradation and by applying the framework into the European Union and its 15 member countries. The results show that the trend in the European Union is a weak de-linking of material flows from economic growth during the years 1980–2000. In other words, material intensity of the economy has generally decreased due to increased efficiency, but the absolute amount of material use has increased, although at a lower rate of increase than economic growth. On the other hand, there is a quite large variation between different EU member countries. However, absolute decrease in the use of materials cannot be found as a continuous trend between the years 1980 and 2000 in any of the studied EU member countries.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号