Model-Based Security Testing

Security testing aims at validating software system requirements related to security properties like confidentiality, integrity, authentication, authorization, availability, and non-repudiation. Although security testing techniques are available for many years, there has been little approaches that allow for specification of test cases at a higher level of abstraction, for enabling guidance on test identification and specification as well as for automated test generation. Model-based security testing (MBST) is a relatively new field and especially dedicated to the systematic and efficient specification and documentation of security test objectives, security test cases and test suites, as well as to their automated or semi-automated generation. In particular, the combination of security modelling and test generation approaches is still a challenge in research and of high interest for industrial applications. MBST includes e.g. security functional testing, model-based fuzzing, risk- and threat-oriented testing, and the usage of security test patterns. This paper provides a survey on MBST techniques and the related models as well as samples of new methods and tools that are under development in the European ITEA2-project DIAMONDS.Comment: In Proceedings MBT 2012, arXiv:1202.582

Organic carbon and its fractions in paddy soil as affected by different nutrient and water regimes

As an essential indicator of soil quality, soil organic carbon (SOC) and its fractions play an important role in many soil chemical, physical, and biological properties. A 4-year field experiment was conducted to determine the effects of different nutrient and water regimes on paddy soil organic carbon quality by measuring the major SOC fractions. Four nutrient regimes were compared: (i) control; (ii) chemical fertilizers only (CF), (iii) combined application of chemical fertilizers with farmyard manure (FYM) (CM), and (iv) combined application of chemical fertilizers and wheat straw (CS). Two soil water regimes included continuous waterlogging (CWL) and alternate wetting and drying (AWD). The total organic carbon (TOC) and total nitrogen (TN) in paddy soil were 40-60% and 37-67% higher in the combined organic sources and chemical fertilizers treatment against the sole chemical fertilizers treatment (CF), especially under continuous waterlogging (CWL). By fractionalizing SOC, it was observed that, under the water regimes of CWL, easily oxidizable carbon (EOC), particulate organic carbon (POC), light fraction organic carbon (LFOC), microbial biomass carbon (MBC), and mineralizable organic carbon (MNC) in the organically treated paddy soil were significantly (P&lt;0.05) lower, as compared with alternate wetting and drying (AWD). Especially for CM treatment, EOC, POC, LFOC, MBC, and MNC in the paddy soils under the regime of CWL were 23.5%, 32.7%, 16.3%, 56.8% and 25.1% lower than those by AWD, respectively. The proportions of EOC, POC, LFOC, MBC and MNC as a percent of TOC in the CWL were lower than those in the AWD, especially for the CM treatment. In the water regime of CWL, no significant differences were seen in the corresponding proportion of all the investigated organic fractions to soil total organic carbon (TOC) among the three fertilization treatments, whereas in the AWD, the corresponding proportions of different carbon fractions to TOC in the organic fertilizer treatments were significantly (P&lt;0.05) higher than those in the chemical fertilizer treatment. Under continuous waterlogging, the proportion of soil water stable aggregate &gt;250 &mu;m (WSA) decreased by 42-45% and clay dispersion ratio (R<inf>CD</inf>) increased by 12-38%, as compared to the water regimes of AWD, when FYM or wheat straw was incorporated into paddy soil. Correlation analysis showed that, under the water regimes of AWD, WSA was significantly and positively related to EOC, LFOC and POC with the coefficients (r) of 0.822, 0.889, 0.912 (P&lt;0.01), respectively. R<inf>CD</inf> was negatively correlated to EOC, LFOC and POC with the r=-0.796, -0.854, and -0.897 (P&lt;0.01), respectively, under AWD. Under the water regimes of CWL, there were no significant (P&lt;0.05) correlations between WSA as well as R <inf>CD</inf> and any organic carbon fraction except POC. &copy; 2004 Elsevier B.V. All rights reserved

Maintaining yields and reducing nitrogen loss in rice–wheat rotation system in Taihu Lake region with proper fertilizer management

In the Tailake region of China, heavy nitrogen (N) loss of rice–wheat rotation systems, due to high fertilizer-N input with low N use efficiency (NUE), was widely reported. To alleviate the detrimental impacts caused by N loss, it is necessary to improve the fertilizer management practices. Therefore, a 3 yr field experiments with different N managements including organic combined chemical N treatment (OCN, 390 kg N ha ^−1 yr ^−1 , 20% organic fertilizer), control–released urea treatment (CRU, 390 kg N ha ^−1 yr ^−1 , 70% resin-coated urea), reduced chemical N treatment (RCN, 390 kg N ha ^−1 yr ^−1 , all common chemical fertilizer), and site-specific N management (SSNM, 333 kg N ha ^−1 yr ^−1 , all common chemical fertilizer) were conducted in the Taihu Lake region with the ‘farmer’s N’ treatment (FN, 510 kg N ha ^−1 yr ^−1 , all common chemical fertilizer) as a control. Grain yield, plant N uptake (PNU), NUE, and N losses via runoff, leaching, and ammonia volatilization were assessed. In the rice season, the FN treatment had the highest N loss and lowest NUE, which can be attributed to an excessive rate of N application. Treatments of OCN and RCN with a 22% reduced N rate from FN had no significant effect on PNU nor the yield of rice in the 3 yr; however, the NUE was improved and N loss was reduced 20–32%. OCN treatment achieved the highest yield, while SSNM has the lowest N loss and highest NUE due to the lowest N rate. In wheat season, N loss decreased about 28–48% with the continuous reduction of N input, but the yield also declined, with the exception of OCN treatment. N loss through runoff, leaching and ammonia volatilization was positively correlated with the N input rate. When compared with the pure chemical fertilizer treatment of RCN under the same N input, OCN treatment has better NUE, better yield, and lower N loss. 70% of the urea replaced with resin-coated urea had no significant effect on yield and NUE improvement, but decreased the ammonia volatilization loss. Soil total N and organic matter content showed a decrease after three continuous cropping years with inorganic fertilizer application alone, but there was an increase with the OCN treatment. N balance analysis showed a N surplus for FN treatment and a balanced N budget for OCN treatment. To reduce the environmental impact and maintain a high crop production, proper N reduction together with organic amendments could be sustainable in the rice–wheat rotation system in the Taihu Lake region for a long run

Large-scale biochar production from crop residue: A new idea and the biogas-energy pyrolysis system

Biochar is an effective means to withdraw carbon dioxide (CO2) from the atmosphere and consequently influence the trend of global climate change. However, there still are substantial knowledge gaps for this idea to be applicable. One big question is how to produce biochar from biomass on a large scale. Our idea is to use biogas produced from agricultural wastes as thermal energy for biochar production from cheap crop residues. A continuous biogas-energy pyrolysis system has been designed and successfully piloted to utilize crop residues for biochar production

The behavior of organic phosphorus under non-point source wastewater in the presence of phototrophic periphyton.

To understand the role of ubiquitous phototrophic periphyton in aquatic ecosystem on the biogeochemical cycling of organic phosphorus, the conversion and removal kinetic characteristics of organic phosphorus (Porg) such as adenosine triphosphate (ATP) were investigated in the presence of the periphyton cultured in artificial non-point source wastewater. The preliminary results showed that the periphyton was very powerful in converting Porg evidenced by the fact that inorganic phosphorus (Pinorg) content in solution increased from about 0.7 to 14.3 mg P L(-1) in 48 hours in the presence of 0.6 g L(-1) periphyton. This was because the periphyton could produce abundant phosphatases that benefited the conversion of Porg to Pinrog. Moreover, this conversion process was described more suitable by the pseudo-first-order kinetic model. The periphyton was also effective in removing Porg, which showed that the Porg can be completely removed even when the initial Porg concentration was as high as 13 mg P L(-1) in 48 hours in the presence of 1.6 g L(-1) periphyton. Furthermore, it was found that biosorption dominated the Porg removal process and exhibited the characteristics of physical adsorption. However, this biosorption process by the periphyton was significantly influenced by biomass (absorbent dosage) and temperature. This work provides insights into Porg biogeochemical circulation of aquatic ecosystem that contained the periphyton or similar microbial aggregates

Bioremediation of Wastewater by Iron Oxide-Biochar Nanocomposites Loaded with Photosynthetic Bacteria

It has been reported that bacteria-mediated degradation of contaminants is a practical and innocuous wastewater treatment. In addition, iron oxide nanoparticles (NP) are wastewater remediation agents with great potentials due to their strong adsorption capacity, chemical inertness and superparamagnetism. Therefore, a combination of NPs and microbes could produce a very desirable alternative to conventional wastewater treatment. For this purpose, we first prepared Fe3O4/biochar nano-composites, followed by loading photosynthetic bacteria (PSB) onto them. It was found that Fe3O4/biochar nano-composites exhibited a high adsorption capacity for PSB (5.45 × 109 cells/g). The efficiency of wastewater pollutants removal by this PSB/Fe3O4/biochar agent was then analyzed. Our results indicated that when loaded onto Fe3O4/biochar nano-composites, PSB’s nutrient removal capability was significantly enhanced (P &lt; 0.05). This agent removed 83.1% of chemical oxygen demand, 87.5% of NH4+, and 92.1% of PO43- from the wastewater in our study. Our experiments also demonstrated that such composites are outstanding recyclable agents. Their nutrient removal capability remained effective even after five cycles. In conclusion, we found the PSB/Fe3O4/biochar composites as a very promising material for bioremediation in the wastewater treatment

Reforming smallholder farms to mitigate agricultural pollution

China’s agriculture is dominated by smallholder farms, which have become major sources of negative environmental impacts including eutrophication, formation of haze, soil acidification and greenhouse gas emissions. To mitigate these environmental impacts, new farming models including family farming, cooperation farming and industrial farming have emerged in recent years. However, whether these new farming practices would improve the economic and environmental performance as compared to the current smallholder farming has yet to be verified on ground level. In this paper, by using pilot farming cases within the watershed of Tai Lake, we found that alternative farming models produced 7% more crop yield, while using 8% less fertilizer, leading to a 28% decrease in pollutant emission per hectare. These alternative farming models have a 17% higher fertilizer use efficiency and 50% higher profit per hectare. Compared to smallholder farming, these alternative farming practices invest 27% more resources into agricultural facilities, including advanced machinery, and have a younger, better educated labor force as a consequence of a larger farm size and more specialization. These input changes substantially increase fertilizer use efficiency and reduce agricultural pollution. Policy arrangements to support and facilitate the uptake of these farming models will further promote the green development and sustainable intensification of agricultural production

Actinobacterial Community Structure in Soils Receiving Long-Term Organic and Inorganic Amendments▿ †

The impact of long-term organic and inorganic amendments on the actinobacterial community in soils was studied. Denaturing gradient gel electrophoresis patterns based on the V3 region of 16S rRNA suggested that there was no significant difference between the communities occurring in the different amendments. However, analysis of the clone libraries of the actinobacterial communities by the use of multiple statistical approaches showed that these communities were significantly different from each other. Results showed that long-term organic and inorganic soil amendments did not significantly alter the overall phylogenetic diversity of the actinobacterial communities but did significantly change the community structure

The Potential of Biochar as N Carrier to Recover N from Wastewater for Reuse in Planting Soil: Adsorption Capacity and Bioavailability Analysis

Recovering nitrogen (N) from agricultural wastewater for reuse in planting fields is a more sustainable and economical strategy to limit N pollution than using conventional treatments. Hereby, regular biochar produced by wheat straw pyrolysis and Mg-modified biochar were used as the N carriers to assess inorganic-N adsorption from simulated agricultural wastewater and the potential for reuse of the carried N in a planting system. The results showed that biochar materials have different affinities towards inorganic-N types. The amount of biochar carried-N increased with the increase in inorganic-N concentration and reached 4.44 mg/g as the maximum. The biochar carried ~4 mg/g of inorganic N substituting nearly 40% of N fertilizer following a 1% w/w addition rate for vegetable planting. After a trial season, 34.7–42.7% of the carried N from biochar was assimilated by the plant, 45.9–53.7% was retained by the soil, and only about 10% was lost. In comparison to the condition with all N inputs from chemical fertilizer, the addition of part of N by the N–biochar matrix significantly reduced the N loss by improving the plant N uptake or increasing the N content in the soil. This study demonstrates that biochar materials could be used as N carriers to recover N from wastewater for reuse in soil, carrier stability, and bioavailability preservation