Experimental study of a Volatiles Distributor for Improving the Cross-sectional Gas Distribution in Fluidized Beds

Chemical looping combustion (CLC) is a promising carbon capture technology due to its inherent CO2 separation. Significant progress has been made in CLC of solid fuels in recent years. However, one key technical challenge for using solid fuels in CLC is to minimize the presence of unreacted gases coming from the fuel reactor together with CO2, in particular for CLC of biomass, i.e. high-volatile fuel. Poor contact between volatiles and oxygen carriers is one reason for the lower gas conversion in the fuel reactor. Hence, the concept of a volatiles distributor (VD) is proposed for achieving a uniform cross-sectional distribution of volatiles, providing better gas-solid contacting and improving the gas conversion in the fuel reactor.In this thesis, the VD was designed with different configurations and investigated in a cold-flow model under different fluidization velocities, volatiles flows and fluidization regimes. It was found that the VD gives a more uniform lateral distribution under higher fluidization velocity. Also, higher volatiles flow gives a more even distribution along the VD. It also shows that less open distribution area of the VD increases the pressure drop over the distribution holes, thus improving the lateral gas distribution. Moving holes from the vicinity of the volatiles injection towards the far end also improves the lateral distribution of volatiles even though it doesn’t change the pressure drop over the distribution holes significantly.The single bubble regime, i.e. large single bubbles formed at the bottom, and multiple bubble regime, i.e. multiple bubbles with different sizes formed at the bottom, were investigated with the VD. It was found that the VD gives a more uniform lateral distribution in single bubble regime compared to the multiple bubble regime. The installation of internal baffles at the bottom of the VD was found to reduce the bottom air flowing into the VD, thus improving the uniformity of the horizontal distribution of the volatiles and further reducing the risk of volatiles slip below the lower edge of the VD

Differential Privacy with Random Projections and Sign Random Projections

In this paper, we develop a series of differential privacy (DP) algorithms from a family of random projections (RP), for general applications in machine learning, data mining, and information retrieval. Among the presented algorithms, \textbf{iDP-SignRP} is remarkably effective under the setting of ``individual differential privacy'' (iDP), based on sign random projections (SignRP). Also, \textbf{DP-SignOPORP} considerably improves existing algorithms in the literature under the standard DP setting, using ``one permutation + one random projection'' (OPORP), where OPORP is a variant of the celebrated count-sketch method with fixed-length binning and normalization. Without taking signs, among the DP-RP family, \textbf{DP-OPORP} achieves the best performance. The concept of iDP (individual differential privacy) is defined only on a particular dataset of interest. While iDP is not strictly DP, iDP might be useful in certain applications, such as releasing a dataset (including sharing embeddings across companies or countries). In our study, we find that \textbf{iDP-SignRP} is remarkably effective for search and machine learning applications, in that the utilities are exceptionally good even at a very small privacy parameter $\epsilon$ (e.g., $\epsilon<0.5$)

Differentially Private One Permutation Hashing and Bin-wise Consistent Weighted Sampling

Minwise hashing (MinHash) is a standard algorithm widely used in the industry, for large-scale search and learning applications with the binary (0/1) Jaccard similarity. One common use of MinHash is for processing massive n-gram text representations so that practitioners do not have to materialize the original data (which would be prohibitive). Another popular use of MinHash is for building hash tables to enable sub-linear time approximate near neighbor (ANN) search. MinHash has also been used as a tool for building large-scale machine learning systems. The standard implementation of MinHash requires applying $K$ random permutations. In comparison, the method of one permutation hashing (OPH), is an efficient alternative of MinHash which splits the data vectors into $K$ bins and generates hash values within each bin. OPH is substantially more efficient and also more convenient to use. In this paper, we combine the differential privacy (DP) with OPH (as well as MinHash), to propose the DP-OPH framework with three variants: DP-OPH-fix, DP-OPH-re and DP-OPH-rand, depending on which densification strategy is adopted to deal with empty bins in OPH. A detailed roadmap to the algorithm design is presented along with the privacy analysis. An analytical comparison of our proposed DP-OPH methods with the DP minwise hashing (DP-MH) is provided to justify the advantage of DP-OPH. Experiments on similarity search confirm the merits of DP-OPH, and guide the choice of the proper variant in different practical scenarios. Our technique is also extended to bin-wise consistent weighted sampling (BCWS) to develop a new DP algorithm called DP-BCWS for non-binary data. Experiments on classification tasks demonstrate that DP-BCWS is able to achieve excellent utility at around $\epsilon = 5\sim 10$, where $\epsilon$ is the standard parameter in the language of $(\epsilon, \delta)$-DP

On the Management of Scientific Research Work in Colleges and Universities of Western Areas

According to the existing condition analysis of academic research management in colleges and universities of the western areas, pointing out there being some existing problems at present, and putting forward to the countermeasures solving these problems. Thinking, as for the colleges and universities of the western areas, on the management of academic research work, are supposed to grasp the complication of it, highlight the local unique features, strengthen the ability of serving local economic, and take an important part in the local economic development

Screening Signal-Manipulating Agents via Contests

We study the design of screening mechanisms subject to competition and manipulation. A social planner has limited resources to allocate to multiple agents using only signals manipulable through unproductive effort. We show that the welfare-maximizing mechanism takes the form of a contest and characterize the optimal contest. We apply our results to two settings: either the planner has one item or a number of items proportional to the number of agents. We show that in both settings, with sufficiently many agents, a winner-takes-all contest is never optimal. In particular, the planner always benefits from randomizing the allocation to some agents

Studies of “emaciation ailment” in the Bactrian camel

The clinical signs of disorder known locally as “emaciation ailment” in Bactrian camels in Haizi, Qinhai, China were defined. They included pica, emaciation, dyskinesia, deprived appetites and anemia. We found that concentrations of copper (Cu) in soil and forage from affected and  unaffected areas were similar, but the concentrations of sulfur (S) in soil and forage were significantly higher (P&lt;0.01) in affected than in unaffected areas. Concentrations of Cu in blood, hair and liver from the affected camels were significantly lower (P&lt;0.01) than those in unaffected camels. Fifty affected camels grazing on affected pastures were consuming an average of 136 mg of Cu/d for 80 d by a free-choice, salt-basedtrace mineral supplement. Liver Cu increased over time in all camels. However, the mean Cu content of the liver was significantly lower in the camels supplemented with salt-based trace mineral as compared with those in the healthy camels at the end of the study. Twelve affected camels were removed from the affected pastures and allocated to one of two treatments for 80 d, consisting of supplement providing 136 mg/d of either inorganic (Cu sulfate; n = 6) or organic (Availa-Cu n = 6) Cu. Liver Cu increased over time in all camels regardless of treatment; however, camels treated with Availa-Cu have higher mean liver Cu contents than those receiving Cu sulfate (163.6 ± 13.5 and 228.9 ± 26.7 μg/g, for Cu sulfate and Availa-Cu, respectively) at the end of the study. Mean Cu content in the liver of camels received Availa-Cu was significantly higher than that in supplemented camels with Cu sulfate. In all treated camels, some signs of recovery were evident in 20 - 30 days after, and appetite and vigor were improved. Thus, it is reasonable to conclude that ailments of camels in the Haizi area are caused by a secondary Cu deficiency, mainly due to high sulfur content in soil and forage.Key words: Bactrian camel, sulfur, copper, deficiency, “emaciation ailment”

The BRICS and the International Development System: Challenge and Convergence?

The ‘BRICs’ acronym, in its most common usage, derives from a report to investors by Goldman Sachs’ analyst Jim O’Neill, signalling the new dynamic that four large countries; Brazil, Russia, India and China, were bringing to the global economy at the beginning of the new millennium. A conclusion advanced in the Goldman Sachs report was that the BRICs should be included in the G7 as their macroeconomic significance increased in the decade to come. From a global investment angle, the world has moved on from there to a wider set of dynamic emerging countries, including a number of fast-growing African nations, as more developing countries find their own way to catch up on growth, resisting world recessionary tendencies (O’Neill 2001 2011). The investor’s world of emerging markets has thus expanded beyond the BRICs, even as questions are raised about the sustainability of growth in the BRICs themselves, with their structural and political challenges and their vulnerability to the uncertainties of global monetary developments. This Evidence Report focuses on a distinct phenomenon – the BRICS Summits, as an ongoing new global governance process, spanning both economic and security issues, launched as a geopolitical initiative by Russia in 2006 at the level of foreign ministers. A first Leaders’ meeting was hosted by Russia in Yekaterinburg in June 2009, bringing in Heads of State from Brazil, India and China. South Africa joined in 2010 on the invitation of China following the Sanya BRIC Summit, to make up the present BRICS Summit group. We look at this BRICS Summit process as part of the broadening of the global governance system created following the Second World War, in which United States (US) leadership and hegemony has been a vital element, to a polycentric global governance system that is now evolving fast but with a future still undetermined (Ikenberry 2006). There is now a burgeoning literature on the BRICS, written in this vein, which is providing some of the keenest contemporary insights into the geopolitics and the geoeconomics of this still to be determined future world order (Carmody 2013; EUISS 2013; Kornegay and Bohler-Muller 2013a, 2013b; Observer Research Foundation 2013; Kornegay 2013a, 2013b, 2013c; Sidaway 2012).UK Department for International Developmen

Pixel Arrangement and Mapping Algorithm for Improving Saturation and Brightness

With the increasing demand for display effects and resolution in the display market, the traditional RGBW permutation has defects such as reduced display saturation and poor image restoration. A new sub-pixel arrangement is designed for these defects, reducing the number of white pixels W and adding yellow pixels Y, which reduces the influence of white pixels on surrounding pixels compared to the conventional RGBW structure. According to the new arrangement method, two new mapping algorithms are designed, and the saturation concept is introduced. The yellow component and the white component are adjusted by the saturation change to effectively improve the image saturation. The simulation shows that the new mapping algorithm (1) has a higher degree of restoration on the image and increases the saturation by 10%. The new mapping algorithm (2) can improve the brightness based on maintaining the high saturation of the original image