Performance of FFH/BFSK product combining receiver over aRician-fading channel with partial-band jamming

A theoretical performance evaluation for an FFH/BFSK spread spectrum product combining receiver over a Rician-fading channel in the presence of partial-band jamming and AWGN is presented. The BER of this receiver is better than that of a linear combining receiver for a strong direct signal, and improvement is significant when diversity is increased     

Performance analysis of an FFH/BFSK linear-combining receiveragainst multitone jamming

A computationally efficient bit-error rate (BER) expression for a fast frequency-hopping binary frequency-shift-keying (FFH/BFSK) spread-spectrum system is derived based on Taylor-series expansion of the central differences. The FFH system employs a soft-decision linear-combining receiver against the worst-case band multitone jamming (MTJ) and additive white Gaussian noise. The analytical results are shown to match closely with the BER results based on simulation. This approach allows us to efficiently analyze the performance of the linear-combining receiver with higher diversity levels, which is otherwise mathematically intractable     

Linked genes for calmodulin and E2 ubiquitin-conjugating enzyme in Trichomonas vaginalis

In searching the genomes of early-diverging protists to study whether the possession of calmodulin is ancestral to all eukaryotes, the gene for calmodulin was identified in Trichomonas vaginalis. This flagellate is a member of the Parabasalia, one of the earliest lineages of recognized eukaryotes to have diverged. This sequence was used to isolate a homologous 1.250-kb fragment from the T. vaginalis genome by inverse polymerase chain reaction. This fragment was also completely sequenced and shown to contain the 3' end of the single-copy calmodulin gene and the 3' end of a gene encoding a protein with high similarity to E2 ubiquitin-conjugating enzymes, a family which has previously only been identified in animals, plants, and fungi. Phylogenetic analysis of 50 members of the E2 family distinguishes at least nine separate subfamilies one of which includes the T. vaginalis E2-homologue and an uncharacterized gene from yeast chromosome XII.     

Cigarette smoking and risk of prostate cancer: a population-based case-control study in Ontario and British Columbia, Canada

The relationship between cigarette smoking and risk of prostate cancer was examined in a case-control study conducted in Ontario and British Columbia, Canada. In each centre, cases were men with a histologically confirmed diagnosis of adenocarcinoma of the prostate notified to the provincial cancer registry. In Ontario, controls were selected randomly from assessment lists maintained by the Ontario Ministry of Revenue and were frequency matched to the cases on age. In British Columbia, controls were also frequency matched to the cases on age and were selected randomly from a roster maintained by the Medical Services Plan of British Columbia. The study in Ontario was conducted between April 1990 and April 1992, and that in British Columbia was conducted between January 1989 and December 1991. In all, the study included 408 cases (207 in Ontario and 201 in British Columbia) and 407 controls (207 in Toronto and 200 in British Columbia (one case was unmatched). Overall, there was little variation in risk of prostate cancer with pack-years of cigarette consumption (filter and non-filter cigarettes combined), and there was no evidence for an effect confined to filter or non-filter cigarettes. There was some evidence for a positive association with non-filter cigarettes in British Columbia, but on formal testing for heterogeneity, this finding was not inconsistent with the absence of an association in Ontario. There was also little variation in risk by years since first smoked or (for ex-smokers) by years since quitting. These data provide little support for an association between cigarette smoking and prostate cancer risk.     

Iterative reduced-complexity multiuser detection based on Chase decoding for synchronous turbo-coded CDMA system

The conventional multiuser detector (MUD) based on the a posteriori probability (APP) algorithm has an exponential computational complexity in terms of the number of users. In this paper, we propose a low-complexity iterative multiuser receiver for synchronous turbo-coded code-division multiple-access (CDMA) systems. The proposed receiver is based on the Chase decoding algorithm that was previously used to decode turbo product codes. Simulation results show that the proposed receiver can significantly reduce the computational complexity with slight performance degradation compared with the APP MUD over highly correlated channels. Moreover, in this paper, we develop a numerical approach to analyze the convergence behavior of iteratively decoded CDMA channels based on density evolution technique. Analytical results are presented and shown to provide a reasonable match with what is observed in simulation.     

A theory of ultradeep hydrodesulfurization of diesel in stacked‐bed reactors

Hydrodesulfurization catalysts have two types of active sites for hydrogenation and hydrogenolysis reactions. While hydrogenation sites are more active for desulfurizing refractory sulfur species, they are more susceptible to organonitrogen inhibition than hydrogenolysis sites. In contrast, hydrogenolysis sites are more resistant to organonitrogen inhibition but are less active for desulfurizing refractory sulfur species. This dichotomy is exploited to develop an ultradeep hydrodesulfurization stacked‐bed reactor comprising two catalysts of different characteristics. The performance of such a catalyst system can be superior or inferior to that of either catalyst alone. A mathematical model is constructed to predict the optimum stacking configuration for maximum synergies between the two catalysts. The best configuration provides the precise environment for the catalysts to reach their full potentials, resulting in the smallest reactor and minimum hydrogen consumption. Model predictions are consistent with experimental results. A selectivity‐activity diagram is developed for guiding the development of stacked‐bed catalyst systems. © 2017 American Institute of Chemical Engineers AIChE J, 64: 595–605, 2018     

A new method for obtaining ultra-low sulfur diesel fuel via ultrasound assisted oxidative desulfurization☆

Due to the requirement of stringent rules for ultra-low sulfur content of diesel fuels, it is necessary to develop alternative methods for desulfurization of fossil fuel derived oil. Using appropriate oxidants and catalysts with the assistance of ultrasound irradiation, model compounds such as dibenzothiophene can be quantitatively oxidized in minutes. For diesel fuels containing various levels of sulfur content, and through the use of catalytic oxidation and ultrasonication followed by solvent extraction, removal efficiency of sulfur-bearing compounds can reach or exceed 99% in a short contact time at ambient temperature and atmospheric pressure. This simple approach can be the basis for obtaining ultra-low sulfur-containing diesel oil. GC-PFPD, GC-MS, and GC-SIMDIS were used to monitor the change of organic sulfur compounds and hydrocarbons in diesels during the process.     

Keratin K15 as a Biomarker of Epidermal Stem Cells

Keratin 15 (K15) is type I keratin protein co-expressed with the K5/K14 pair present in the basal keratinocytes of all stratified epithelia. Although it is a minor component of the cytoskeleton with a variable expression pattern, nonetheless its expression has been reported as a stem cell marker in the bulge of hair follicles. Conversely, suprabasal expression of K15 has also been reported in both normal and diseased tissues, which is inconsistent with its role as a stem cell marker. Our recently published work has given evidence of the molecular pathways that seem to control the expression of K15 in undifferentiated and differentiated cells. In this article, we have critically reviewed the published work to establish the reliability of K15 as an epidermal stem cell marker.     

Material flow analysis of cadmium applied to review MSW treatment in Taiwan

Abstract

This study applies the material flow analysis (MFA) of Cadmium to evaluate municipal solid waste (MSW) management policy in Taiwan.

In 2002, the Cd flow in Taiwan was approximately 441.2 tons, mainly contributed by the Cd in nickel‐cadmium batteries (60.15%) and plastics (33.45%). 415.6 tons of Cd entered the MSW treatment system from consumers. However, aside from the Cd emitted into the atmosphere (0.4 tons) and the Cd in incinerator ash (15.1 tons), the recycled Cd was 5.2 tons, representing a recycling rate of 1.2%. Moreover, instead of being effectively used, the recycled Cd is often casually deposited in the environment. Currently, Taiwan's Cd MFA data indicates that the MSW treatment is mainly performed by incineration, which does not conform to the main principles of sustainable development. To achieve a more sustainable policy, recycling and/or restriction of nickel‐cadmium batteries and plastics turn out to be important issues.