Area Spectral Efficiency Analysis and Energy Consumption Minimization in Multi-Antenna Poisson Distributed Networks

This paper aims at answering two fundamental questions: how area spectral efficiency (ASE) behaves with different system parameters; how to design an energy-efficient network. Based on stochastic geometry, we obtain the expression and a tight lower-bound for ASE of Poisson distributed networks considering multi-user MIMO (MU-MIMO) transmission. With the help of the lower-bound, some interesting results are observed. These results are validated via numerical results for the original expression. We find that ASE can be viewed as a concave function with respect to the number of antennas and active users. For the purpose of maximizing ASE, we demonstrate that the optimal number of active users is a fixed portion of the number of antennas. With optimal number of active users, we observe that ASE increases linearly with the number of antennas. Another work of this paper is joint optimization of the base station (BS) density, the number of antennas and active users to minimize the network energy consumption. It is discovered that the optimal combination of the number of antennas and active users is the solution that maximizes the energy-efficiency. Besides the optimal algorithm, we propose a suboptimal algorithm to reduce the computational complexity, which can achieve near optimal performance.Comment: Submitted to IEEE Transactions on Wireless Communications, Major Revisio

Numerical Calculation of Transient Thermal Characteristics in Gas-Insulated Transmission Lines

For further knowledge of the thermal characteristics in gas-insulated transmission lines (GILs) installed above ground, a finite-element model of coupling fluid field and thermal field is established, in which the corresponding assumptions and boundary conditions are given.  Transient temperature rise processes of the GIL under the conditions of variable ambient temperature, wind velocity and solar radiation are respectively investigated. Equivalent of surface convective heat transfer coefficient and heat flux boundary conditions are updated in the analysis process. Unlike the traditional finite element method (FEM), the variability of the thermal properties with temperature is considered. The calculation results are validated by the tests results reported in the literature. The conclusion provides method and theory basis for the knowledge of transient temperature rise characteristics of GILs in open environment

Ursolic Acid Inhibits Proliferation and Induces Apoptosis of Cancer Cells In Vitro and In Vivo

The aims of the study are to explore the effect of ursolic acid (UA) on the growth of gastric cancer cell line BGC-803 and hepatocellular cancer cell H22 xenograft and to understand the mechanism. UA inhibits growth of BGC-803 cells in vitro in dose-dependent and time-dependent manner. Treated with UA in vivo, tumor cells can be arrested to G0/G1 stage. The apoptotic rate was significantly increased in tumor cells treated with UA both in vitro and in vivo. DNA fragmentation was found in BGC-803 cells exposed to UA. UA activated caspase-3, -8, and -9 and down regulated expression of Bcl-2 in BGC-803 cells. The expression of caspase-3 and -8 was elevated in tumor cells from xenograft treated with UA. 18F-FLT PET-CT imaging confirmed tumor model and UA effectiveness. Our results indicated that UA inhibits growth of tumor cells both in vitro and in vivo by decreasing proliferation of cells and inducing apoptosis

Comparison of different mechanical refining technologies on the enzymatic digestibility of low severity acid pretreated corn stover

AbstractThe effect of mechanical refining on the enzymatic digestibility of pretreated corn stover (PCS) was investigated. Low severity, dilute sulfuric acid PCS was subjected to mechanical refining using a bench-scale food processor blender, a PFI mill, a 12-inch laboratory disk refiner, and a 25mm co-rotating twin-screw extruder. Glucose yields from enzymatic hydrolysis were improved by 10–15% after blending and disk refining, while PFI refining and twin-screw extrusion showed a glucose yield improvement of 16–20%. A pilot scale refining test using a Szego mill was performed and showed approximately 10% improvements in biomass digestibility. This suggests the possibility to scale up a mechanical refining technique to obtain similar enzymatic digestibility glucose yield enhancement as achieved by PFI milling and extrusion technologies. Proposed mechanisms of each mechanical refining technology are presented and reasons for improvements in biomass digestibility are discussed in this paper

Recycling of Dilute Deacetylation Black Liquor to Enable Efficient Recovery and Reuse of Spent Chemicals and Biomass Pretreatment Waste

Deacetylation/dilute alkaline pretreatment followed by mechanical refining (DMR) has been proven as an effective process for biomass sugar liberation without severe chemical modification to lignin. Previous research has been focused on optimizing deacetylation conditions, reducing energy consumptions in mechanical refining, and improving sugar yields and titers in enzymatic hydrolysis. To successfully commercialize this process, another critical challenge is to develop a robust process to balance water usage, recover spent chemicals, and utilize waste carbons from the dilute deacetylation waste liquor. In this work, a new process modification and strategy is pioneered to recycle and reuse the weak black liquor (WBL) in order to reduce water, chemical, and energy usage while increasing both inorganic and organic contents in the WBLto facilitate downstream processing. Results suggest that the accumulation did not lower acetyl and lignin removal in alkaline pretreatment, resulting in comparable sugar yields in enzymatic hydrolysis. Sodium and potassium were found to be the two most important inorganic compounds in the recycled WBL. Moreover, the accumulated sodium and phenolic compounds did not inhibit the downstream ethanol fermentation processes. Finally, techno-economic analysis (TEA) showed a decrease in the minimum ethanol selling price (MESP) by ~5 to 15 cents per gallon of ethanol resulting from the inclusion of the recycling of weak black liquor when compared to a conventional non-recycling process

A SWOT Analysis of the Use of Marine, Grain, Terrestrial-Animal and Novel Protein Ingredients in Aquaculture Feeds

A variety of new feed ingredients are emerging in the aquaculture feed sector. While the technology readiness of these options varies across and within the new ingredient classes, it remains important to consider them in terms of the overall feed ingredient spectrum. In this review, the use of marine, grain, terrestrial animal by-product and a range of novel (e.g., bacterial and yeast) resources being considered as potential protein feedstuffs for use in aquafeeds is explored. In comparing the nutritional attributes of each of the ingredient classes, an assessment framework is applied based on understanding the critical knowledge required to be able to accommodate any ingredient in a formulation process. To further examine each of the different ingredient classes a Strength-Weakness-Opportunity-and-Threats (SWOT) analysis is applied, to enable some consideration of what future potential may exist across the spectrum and what risks and opportunities they may bring. It is noted that all ingredients have strengths and weaknesses, and that there is no such thing as the perfect ingredient. By better appreciating the positives and negatives of each ingredient, it becomes possible to increase adaptability in responding to the various opportunities for their use in feeds

A SWOT Analysis of the Use of Marine, Grain, Terrestrial-Animal and Novel Protein Ingredients in Aquaculture Feeds

A variety of new feed ingredients are emerging in the aquaculture feed sector. While the technology readiness of these options varies across and within the new ingredient classes, it remains important to consider them in terms of the overall feed ingredient spectrum. In this review, the use of marine, grain, terrestrial animal by-product and a range of novel (e.g., bacterial and yeast) resources being considered as potential protein feedstuffs for use in aquafeeds is explored. In comparing the nutritional attributes of each of the ingredient classes, an assessment framework is applied based on understanding the critical knowledge required to be able to accommodate any ingredient in a formulation process. To further examine each of the different ingredient classes a Strength-Weakness-Opportunity-and-Threats (SWOT) analysis is applied, to enable some consideration of what future potential may exist across the spectrum and what risks and opportunities they may bring. It is noted that all ingredients have strengths and weaknesses, and that there is no such thing as the perfect ingredient. By better appreciating the positives and negatives of each ingredient, it becomes possible to increase adaptability in responding to the various opportunities for their use in feeds

A Role for a Dioxygenase in Auxin Metabolism and Reproductive Development in Rice

SummaryIndole-3-acetic acid (IAA), the natural auxin in plants, regulates many aspects of plant growth and development. Extensive analyses have elucidated the components of auxin biosynthesis, transport, and signaling, but the physiological roles and molecular mechanisms of auxin degradation remain elusive. Here, we demonstrate that the dioxygenase for auxin oxidation (DAO) gene, encoding a putative 2-oxoglutarate-dependent-Fe (II) dioxygenase, is essential for anther dehiscence, pollen fertility, and seed initiation in rice. Rice mutant lines lacking a functional DAO display increased levels of free IAA in anthers and ovaries. Furthermore, exogenous application of IAA or overexpression of the auxin biosynthesis gene OsYUCCA1 phenocopies the dao mutants. We show that recombinant DAO converts the active IAA into biologically inactive 2-oxoindole-3-acetic acid (OxIAA) in vitro. Collectively, these data support a key role of DAO in auxin catabolism and maintenance of auxin homeostasis central to plant reproductive development