Heat and mass transfer studies of palm kernel cake (PKC) in fluidized bed fermenter

Solid state fermentation (SSF) which involves the growth of microorganism on moist solid substrates in the absence of free flowing water, has gained renewed attention over submerged fermentation for specific applications. During the SSF process in fermenter, there are three main engineering problems encountered such as the removal of metabolic heat from the substrate, diffusion of O2 and moisture through the substrate, and heterogeneity of the substrate and inoculum. A fluidized bed fermenter in which the particles move independently like a fluid was proposed to conduct the study. Throughout the study, rapid heat transfer from PKC to air was experimentally observed within the first 150 s with a temperature drop of 30 °C. This indicated that the excellent heat transfer between palm kernel cake and air allows solid state fermentation of PKC without accumulation of metabolic heat in the fermenter. Apart from heat removal, water adsorption study on PKC from air to bed was carried out. It showed that the increase of adsorbed water in PKC was proportional to air relative humidity and inversely proportional to superficial air velocity. The maximum moisture content adsorbed by PKC under fluidization conditions was around 10% (on dry basis). Finally, mathematical models for heat and mass transfer were proposed which can predict the experimental data quite satisfactorily

Study of aqueous and non-aqueous phase liquid in fractured double-porosity soil using digital image processing

The leakage and spillage of non-aqueous phase liquids (NAPLs) and aqueous phase liquids (APLs) contribute to groundwater contamination, resulting in groundwater pollution and rendering the quality of groundwater unsafe for drinking and agriculture. Ensuring the availability and sustainable management of water and sanitation for all was the goal and target of the 2030 United Nations agenda for sustainable development, consisting of a plan of action for the population, the planet and general prosperity. This paper is intended to investigate the aqueous and non-aqueous phase liquid migrations in a deformable double-porosity soil, which has become important for both sustainable groundwater use and the comprehensive understanding of the behaviour of liquid migration into groundwater. A modelling experiment was conducted in an attempt to study the pattern and behaviour of aqueous and non-aqueous phase liquid migration in fractured double-porosity soil using a digital image processing technique. The results of the experiments show that the flow of the APL and NAPL migration was not uniformly downward. Faster migration occurred where the soil surface was cracked compared to other locations where the soil surface was not cracked, even when liquids such as toluene were not used. It was concluded that the factors that significantly influenced the APL and NAPL migration were the structure of the soil sample, fracture pattern of the soil sample, physical interaction i.e. bonding between the liquid and soil sample, and the capillary pressure of the fluid. This study indicates that digital image analysis can provide detailed information to help researchers better understand and be able to simulate the pattern and characteristics of liquid migration that have an influence on groundwater resources

TIM3+FOXP3+ regulatory T cells are tissue-specific promoters of T-cell dysfunction in cancer

T-cell immunoglobulin mucin 3 (TIM3) is an inhibitory molecule that has emerged as a key regulator of dysfunctional or exhausted CD8+ T cells arising in chronic diseases such as cancer. In addition to exhausted CD8+ T cells, highly suppressive regulatory T cells (Tregs) represent a significant barrier against the induction of antitumor immunity. We have found that the majority of intratumoral FOXP3+ Tregs express TIM3. TIM3+ Tregs co-express PD-1, are highly suppressive and comprise a specialized subset of tissue Tregs that are rarely observed in the peripheral tissues or blood of tumor-bearing mice. The co-blockade of the TIM3 and PD-1 signaling pathways in vivo results in the downregulation of molecules associated with TIM3+ Treg suppressor functions. This suggests that the potent clinical efficacy of co-blocking TIM3 and PD-1 signal transduction cascades likely stems from the reversal of T-cell exhaustion combined with the inhibition of regulatory T-cell function in tumor tissues. Interestingly, we find that TIM3+ Tregs accumulate in the tumor tissue prior to the appearance of exhausted CD8+ T cells, and that the depletion of Tregs at this stage interferes with the development of the exhausted phenotype by CD8+ T cells. Collectively, our data indicate that TIM3 marks highly suppressive tissue-resident Tregs that play an important role in shaping the antitumor immune response in situ, increasing the value of TIM3-targeting therapeutic strategies against cancer

Vibration effect influence upon non-aqueous phase liqumigration in double-porosity soil

Natural disasters such as earthquakes, El-Nino, tsunamis and water pollution have a negative impact on human health and living environment. Some of these may give rise to subsurface vibrations that can potentially increase groundwater pollution risks in double-porosity systems. The more complicated situation was where underground storage tanks and petroleum pipeline damage have caused the leakage of non-aqueous phase liquids (NAPLs) which migrated into the groundwater resources. These problems need to be addressed by both professionals and researchers worldwide to ensure the sustainability of groundwater utilization. This paper aims to investigate and understand NAPL migration in vibrated double-porosity soils. To do so it was necessary to study the phenomena and characteristic of soil structure and the pattern of NAPL migration to identify cost-effective remediation schemes. A laboratory experiment was conducted to study the phenomena and characteristics of vibration response and NAPL migration in double-porosity soil deformation under vibration effect using a digital image processing technique (DIPT). The outcomes of the experiment show that the gradual increase of vibration table excitation frequency yielded different vibration responses from the respective soils. This indicated that soil surface acceleration depended significantly on the soil conditions, soil water content, soil structure and the pattern of soil fracturing. NAPL migration was faster in sample 2 with 150ml toluene than sample 1 with 70ml toluene and this could be because the greater amount of toluene in sample 2 exerted an extra entry force on top of the soil sample that had yet to migrate through the sample surface. Finally, it was concluded that the DIPT may provide detailed information, and can be used to understand and identify the remediation method as well as to ensure the sustainable consumption of groundwater

Ant Colony Optimization for the Design of Water Distribution Systems

During the last decade, evolutionary methods such as genetic algorithms have been developed for the optimal design and operation of water distribution systems. More recently, ant colony optimization algorithms (ACOAs), which are evolutionary methods based on the foraging behavior of ants, been successfully applied to a number of benchmark combinatorial optimization problems. For example, when applied to the traveling salesman problem, ACOAs have been shown to outperform genetic algorithms. In this paper, a formulation is developed which enables ACOAs to be used for the optimal design of water distribution systems. This formulation is applied to a benchmark water distribution system optimization problem and the results are compared with those obtained using genetic algorithms. The findings of this study indicate that the performance of ACOAs is comparable with that of GAs for the case study considered. The GA performed slightly better in terms of finding the optimal solution from different starting positions in the search space, whereas the ACOA perfomed better in terms of the number of evaluations needed to reach the optimum.Holger R. Maier, Angus R. Simpson, W. K. Foong, K. Y. Phang, H. Y. Seah, and C. L. Ta

Statistical distribution of quantum entanglement for a random bipartite state

We compute analytically the statistics of the Renyi and von Neumann entropies (standard measures of entanglement), for a random pure state in a large bipartite quantum system. The full probability distribution is computed by first mapping the problem to a random matrix model and then using a Coulomb gas method. We identify three different regimes in the entropy distribution, which correspond to two phase transitions in the associated Coulomb gas. The two critical points correspond to sudden changes in the shape of the Coulomb charge density: the appearance of an integrable singularity at the origin for the first critical point, and the detachement of the rightmost charge (largest eigenvalue) from the sea of the other charges at the second critical point. Analytical results are verified by Monte Carlo numerical simulations. A short account of some of these results appeared recently in Phys. Rev. Lett. {\bf 104}, 110501 (2010).Comment: 7 figure

Power plant maintenance scheduling using ant colony optimization: an improved formulation

Abstract It is common practice in the hydropower industry to either shorten the maintenance duration or to postpone maintenance tasks in a hydropower system when there is expected unserved energy based on current water storage levels and forecast storage inflows. It is therefore essential that a maintenance scheduling optimizer can incorporate the options of shortening the maintenance duration and/or deferring maintenance tasks in the search for practical maintenance schedules. In this article, an improved ant colony optimization-power plant maintenance scheduling optimization (ACO-PPMSO) formulation that considers such options in the optimization process is introduced. As a result, both the optimum commencement time and the optimum outage duration are determined for each of the maintenance tasks that need to be scheduled. In addition, a local search strategy is presented in this article to boost the robustness of the algorithm. When tested on a five-station hydropower system problem, the improved formulation is shown to be capable of allowing shortening of maintenance duration in the event of expected demand shortfalls. In addition, the new local search strategy is also shown to have significantly improved the optimization ability of the ACO-PPMSO algorithm

Using Tracker as a Pedagogical Tool for Understanding Projectile Motion

This paper reports the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When computer model building learning processes is supported and driven by video analysis data, this free Open Source Physics (OSP) tool can provide opportunities for students to engage in active inquiry-based learning. We discuss the pedagogical use of Tracker to address some common misconceptions of projectile motion by allowing students to test their hypothesis by juxtaposing their mental models against the analysis of real life videos. Initial research findings suggest that allowing learners to relate abstract physics concepts to real life through coupling computer modeling with traditional video analysis could be an innovative and effective way to learn projectile motion. 2015 Resources: http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/01-kinematics/174-projectile-motionComment: 9 pages, 9 figures; http://iopscience.iop.org/0031-9120/47/4/44

Many body physics from a quantum information perspective

The quantum information approach to many body physics has been very successful in giving new insight and novel numerical methods. In these lecture notes we take a vertical view of the subject, starting from general concepts and at each step delving into applications or consequences of a particular topic. We first review some general quantum information concepts like entanglement and entanglement measures, which leads us to entanglement area laws. We then continue with one of the most famous examples of area-law abiding states: matrix product states, and tensor product states in general. Of these, we choose one example (classical superposition states) to introduce recent developments on a novel quantum many body approach: quantum kinetic Ising models. We conclude with a brief outlook of the field.Comment: Lectures from the Les Houches School on "Modern theories of correlated electron systems". Improved version new references adde

Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16

Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP