Identification of the thermal phases in firing of kaolinite to mullite by using micro-Raman spectroscopy and curve-fitting

Firing of kaolinite to mullite is an important process in ceramic industry. In the present study, Raman spectroscopy and curve-fitting are utilized for identification of the thermal phases in progressive firing of kaolinite to mullite up to 1300 °C. The results are compared to that observed by XRD. Many natural kaolinites consist of accessory anatase, and this mineral has strong Raman bands. Therefore, the spectra of anatase-free and anatase-containing kaolinites were analyzed. The Raman response is sensitive to the degree of the structural order of the thermal phases. Dehydroxylated kaolinite is detected at 500 °C by the disappearance of the Raman bands of the kaolinite. The metakaolinite at 700 °C and the spinel-type phase at 1000 °C have broad and weak Raman bands due to their short-range and poorly-order structure, respectively. Amorphous silica is observed at 1000 °C by the development of diagnostic broad and weak Raman bands. Mullite and cristobalite are detected at 1300 °C by the appearance of characteristic Raman bands. In firing of anatase-containing kaolinite, progressive thermal transform from anatase to rutile is observed at 1100–1300 °C by the appearance of Raman bands of rutile and by the decreasing of the anatase bands. The results can be applied in using micro-Raman spectroscopy as a non-destructive method for identification of thermal phases in the composition of modern and ancient ceramic.     

LDPC coded MIMO multiple access with iterative joint decoding

An efficient scheme for the multiple-access multiple-input multiple-output (MIMO) channel is proposed, which operates well also in the single user regime, as well as in a direct-sequence spread-spectrum (DS-CDMA) setting. The design features scalability and is of limited complexity. The system employs optimized low-density parity-check (LDPC) codes and an efficient iterative (belief propagation-BP) detection which combines linear minimum mean-square error (LMMSE) detection and iterative interference cancellation (IC). This combination is found to be necessary for efficient operation in high system loads /spl alpha/>1. An asymptotic density evolution (DE) is used to optimize the degree polynomials of the underlining LDPC code, and thresholds as close as 0.77 dB to the channel capacity are evident for a system load of 2. Replacing the LMMSE with the complex individually optimal multiuser detector (IO-MUD) further improves the performance up to 0.14 dB from the capacity. Comparing the thresholds of a good single-user LDPC code to the multiuser optimized LDPC code, both over the above multiuser channel, reveals a surprising 8-dB difference, emphasizing thus the necessity of optimizing the code. The asymptotic analysis of the proposed scheme is verified by simulations of finite systems, which reveal meaningful differences between the performances of MIMO systems with single and multiple users and demonstrate performance similar to previously reported techniques, but with higher system loads, and significantly lower receiver complexity.     

The mental health of men with a psychiatric disorder or traumatic brain injury: Wives' labeling and husbands' perceived control.

Objective: To investigate the relations among wives' labeling of their husbands' psychiatric disorder or brain injury as an organic illness, the husbands' perceived control over their disabilities, and the husbands' mental health. Participants: 57 male clients of the Department of Rehabilitation, Israel's Ministry of Defence (26 with a psychiatric disorder and 31 with a traumatic brain injury) and their wives. Measures: Illness Labeling Questionnaire, the Perceived Control Over Illness Questionnaire, and the Mental Health Inventory. Results: Husbands' mental health was low but did not differ according to disability; wives' labeling of husbands' condition was negatively related to the husbands' mental health; husbands' perceived control was positively related to their mental health for both disabilities. Conclusion: Organic illness labels, even when adopted by the wives of the persons with the disability, seem to be negatively related to that person's mental health, whereas perceived control over a mental disorder or a brain injury seems to contribute positively to mental health, independently of how the disorder or injury is labeled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Path-Based Algorithm for the Cross-Nested Logit Stochastic User Equilibrium Traffic Assignment

Abstract:   This article investigates the single-class static stochastic user equilibrium (SUE) problem with separable and additive link costs. A SUE assignment based on the Cross-Nested Logit (CNL) route choice model is presented. The CNL model can better represent route choice behavior compared to the Multinomial Logit (MNL) model, while keeping a closed form equation. The article uses a specific optimization formulation developed for the CNL model, and develops a path-based algorithm for the solution of the CNL-SUE problem based on adaptation of the disaggregate simplicial decomposition (DSD) method. The article illustrates the algorithmic implementation on a real size network and discusses the trade-offs between MNL-SUE and CNL-SUE assignment .     

Transmitting to colocated users in wireless ad hoc and sensor networks

We consider wireless ad hoc networks and sensor networks where a remotely located source is transmitting information to a destined user embedded within a group of K densely packed physically colocated users enjoying favorable signal-to-noise ratio (SNR) conditions among themselves, but suffering from quasi-static flat Rayleigh fading with respect to the source. Stringent delay constraints require that information, once available, be transmitted immediately and delivered reliably to its destination during a period of one fading block, precluding waiting until the destined user enjoys favorable fading conditions with respect to the source. A cooperative transmission strategy is proposed for this scenario and its expected throughput is investigated. The strategy exhibits a substantial gain in throughput, especially when the colocation gain factor is high. In addition, a broadcast approach is incorporated into the transmission strategy suggesting further throughput benefits.     

Mutual Information and Conditional Mean Estimation in Poisson Channels

Following the discovery of a fundamental connection between information measures and estimation measures in Gaussian channels, this paper explores the counterpart of those results in Poisson channels. In the continuous-time setting, the received signal is a doubly stochastic Poisson point process whose rate is equal to the input signal plus a dark current. It is found that, regardless of the statistics of the input, the derivative of the input-output mutual information with respect to the intensity of the additive dark current can be expressed as the expected difference between the logarithm of the input and the logarithm of its noncausal conditional mean estimate. The same holds for the derivative with respect to input scaling, but with the logarithmic function replaced by x log x. Similar relationships hold for discrete-time versions of the channel where the outputs are Poisson random variables conditioned on the input symbols.     

Efficiency of phenol biodegradation by planktonic Pseudomonas pseudoalcaligenes (a constructed wetland isolate) vs. root and gravel biofilm

In the last two decades, constructed wetland systems gained increasing interest in wastewater treatment and as such have been intensively studied around the world. While most of the studies showed excellent removal of various pollutants, the exact contribution, in kinetic terms, of its particular components (such as: root, gravel and water) combined with bacteria is almost nonexistent.In the present study, a phenol degrader bacterium identified as Pseudomonas pseudoalcaligenes was isolated from a constructed wetland, and used in an experimental set-up containing: plants and gravel. Phenol removal rate by planktonic and biofilm bacteria (on sterile Zea mays roots and gravel surfaces) was studied. Specific phenol removal rates revealed significant advantage of planktonic cells (1.04 × 10⁻⁹ mg phenol/CFU/h) compared to root and gravel biofilms: 4.59 × 10⁻¹¹-2.04 × 10⁻¹⁰ and 8.04 × 10⁻¹¹-4.39 × 10⁻¹⁰ (mg phenol/CFU/h), respectively.In batch cultures, phenol biodegradation kinetic parameters were determined by biomass growth rates and phenol removal as a function of time. Based on Haldane equation, kinetic constants such as μ_max = 1.15/h, K_s = 35.4 mg/L and K_i = 198.6 mg/L fit well phenol removal by P. pseudoalcaligenes.Although P. pseudoalcaligenes planktonic cells showed the highest phenol removal rate, in constructed wetland systems and especially in those with sub-surface flow, it is expected that surface associated microorganisms (biofilms) will provide a much higher contribution in phenol and other organics removal, due to greater bacterial biomass.Factors affecting the performance of planktonic vs. biofilm bacteria in sub-surface flow constructed wetlands are further discussed.     

Synergistic activity between a spinach-derived natural antioxidant (NAO) and commercial antioxidants in a variety of oxidation systems

Recently, there has been great interest in the potential health benefits of foods containing polyphenols, especially from plants, due to their antioxidant content. Natural antioxidant (NAO) is a unique, powerful antioxidant which was isolated in our lab from spinach leaves. The main goal of this study was to examine potential synergistic activity in combinations of NAO and commercial antioxidants. The antioxidant activity was tested in several in vitro systems including fatty acid and fat oxidation and also in cancer cell lines. We used the unique optical live cell array (LCA) technology to monitor the generation of reactive oxygen species (ROS) in single cells over time. NAO was combined with selected commercial antioxidants, and synergistic activity that reduced ROS generation was found with three polyphenols – ferulic acid, caffeic acid, and epigallocatechin-3-gallate (EGCG). These findings demonstrate the importance of using antioxidant ‘cocktails’ which may enhance medical effects in many kinds of diseases, including cardiovascular diseases and cancer.     

Authorship attribution in the wild

Most previous work on authorship attribution has focused on the case in which we need to attribute an anonymous document to one of a small set of candidate authors. In this paper, we consider authorship attribution as found in the wild: the set of known candidates is extremely large (possibly many thousands) and might not even include the actual author. Moreover, the known texts and the anonymous texts might be of limited length. We show that even in these difficult cases, we can use similarity-based methods along with multiple randomized feature sets to achieve high precision. Moreover, we show the precise relationship between attribution precision and four parameters: the size of the candidate set, the quantity of known-text by the candidates, the length of the anonymous text and a certain robustness score associated with a attribution.