Analysis of greenhouse gas generation models at household waste landfills for ecosystem applications

The control and minimization of greenhouse gas emissions is an important task of modern ecology. One of the sources of greenhouse gases is landfills of household waste (LHW). A special feature of LHWs, as a source of greenhouse gases, is the complexity of estimating emissions. The fact is that the production of greenhouse gases (mainly methane) at LHW is a long process, time-consuming and dependent on many factors. In particular, the rate of putrefaction of organic waste depends on environmental parameters, such as temperature, humidity, and precipitation patterns. Knowing the estimates of greenhouse gas emissions, it is possible to develop an appropriate technology for their disposal, taking into account the regional features of the location of landfills. A mathematical model of gas formation on LHWs is required to solve the problem of predicting greenhouse gas emissions from these landfills. Currently, there are several generally accepted models of LHW. This paper reviews the three main models used in world practice: LandGEM, EPER-Germany, and TNO in terms of their universality and applicability for describing LHW from Siberia region. It was shown that the most promising model is LandGEM

Patterns of calcium oxalate monohydrate crystallization in complex biological systems

The paper presents the features of calcium oxalate crystallization in the presence of additives revealed through experimental modeling. The patterns of phase formation are shown for the Ca{2+} – C[2]O[4]{ 2–} – H[2]O and Ca{2+} – C[2]O[4]{2–} – PO[4]{3–} – H[2]O systems with the components and pH of the saline varying over a wide concentrations range. The effect of additives on crystallization of calcium oxalate monohydrate was investigated. It was found that the ionic strength and magnesium ions are inhibitors, and calcium oxalate and hydroxyapatite crystals are catalysts of calcium oxalate monohydrate crystallization. The basic calcium phosphate (apatite) was found to be most thermodynamically stable, which indicates its special role in kidney stone formation since it is found in virtually all stones

Breaking The FF3 Format-Preserving Encryption Standard Over Small Domains

The National Institute of Standards and Technology (NIST) recently published a Format-Preserving Encryption standard accepting two Feistel structure based schemes called FF1 and FF3. Particularly, FF3 is a tweakable block cipher based on an 8-round Feistel network. In CCS~2016, Bellare et. al. gave an attack to break FF3 (and FF1) with time and data complexity $O(N^5\log(N))$, which is much larger than the code book (but using many tweaks), where $N^2$ is domain size to the Feistel network. In this work, we give a new practical total break attack to the FF3 scheme (also known as BPS scheme). Our FF3 attack requires $O(N^{\frac{11}{6}})$ chosen plaintexts with time complexity $O(N^{5})$. Our attack was successfully tested with $N\leq2^9$. It is a slide attack (using two tweaks) that exploits the bad domain separation of the FF3 design. Due to this weakness, we reduced the FF3 attack to an attack on 4-round Feistel network. Biryukov et. al. already gave a 4-round Feistel structure attack in SAC~2015. However, it works with chosen plaintexts and ciphertexts whereas we need a known-plaintext attack. Therefore, we developed a new generic known-plaintext attack to 4-round Feistel network that reconstructs the entire tables for all round functions. It works with $N^{\frac{3}{2}} \left( \frac{N}{2} \right)^{\frac{1}{6}}$ known plaintexts and time complexity $O(N^{3})$. Our 4-round attack is simple to extend to five and more rounds with complexity $N^{(r-5)N+o(N)}$. It shows that FF1 with $N=7$ and FF3 with $7\leq N\leq10$ do not offer a 128-bit security. Finally, we provide an easy and intuitive fix to prevent the FF3 scheme from our $O(N^{5})$ attack

Attacks Only Get Better: How to Break FF3 on Large Domains

We improve the attack of Durak and Vaudenay (CRYPTO\u2717) on NIST Format-Preserving Encryption standard FF3, reducing the running time from $O(N^5)$ to $O(N^{17/6})$ for domain $Z_N \times Z_N$. Concretely, DV\u27s attack needs about $2^{50}$ operations to recover encrypted 6-digit PINs, whereas ours only spends about $2^{30}$ operations. In realizing this goal, we provide a pedagogical example of how to use distinguishing attacks to speed up slide attacks. In addition, we improve the running time of DV\u27s known-plaintext attack on 4-round Feistel of domain $Z_N \times Z_N$ from $O(N^3)$ time to just $O(N^{5/3})$ time. We also generalize our attacks to a general domain $Z_M \times Z_N$, allowing one to recover encrypted SSNs using about $2^{50}$ operations. Finally, we provide some proof-of-concept implementations to empirically validate our results

On C2 C^2-stable effects of intermingled basins of attractors in classes of boundary-preserving maps

International audienceIn the spaces of boundary-preserving maps of an annulus and a thickened torus, we construct open sets in which every map has intermingled basins of attraction, as predicted by I. Kan.Namely, the attraction basins of each of the boundary components are everywhere dense in the phase space for such maps. Moreover, the Hausdorff dimension of the set of points that are not attracted by either of the components proves to be less than the dimension of the phase space itself, which strengthens the result following from the argument due to Bonatti, Diaz, and Viana