Electrostatic image effects for counter-ions between charged planar walls

We study the effect of dielectric inhomogeneities on the interaction between two planparallel charged surfaces with oppositely charged mobile charges in between. The dielectric constant between the surfaces is assumed to be different from the dielectric constant of the two semiinfinite regions bounded by the surfaces, giving rise to electrostatic image interactions. We show that on the weak coupling level the image charge effects are generally small, making their mark only in the second order fluctuation term. However, in the strong coupling limit, the image effects are large and fundamental. They modify the interactions between the two surfaces in an essential way. Our calculations are particularly useful in the regime of parameters where computer simulations would be difficult and extremely time consuming due to the complicated nature of the long range image potentials.Comment: 21 pages, 8 figure

Counterion-mediated Electrostatic Interactions between Helical Molecules

We study the interaction of two cylinders with helical charge distribution mediated by neutralizing counterions, by analyzing the separation as well as the azimuthal angle dependence of the interaction force in the weak and strong coupling limit. While the azimuthal dependence of the interaction in the weak coupling limit is overall small and mostly negligible, the strong coupling limit leads to qualitatively new features of the interaction, among others also to an orientationally dependent optimal configuration that is driven by angular dependence of the correlation attraction. We investigate the properties of this azimuthal ordering in detail and compare it to existing results.Comment: 11 pages, 12 figure

Dates of birth and seasonal changes in well-being among 4904 subjects completing the seasonal pattern assessment questionnaire

Background: Abnormal distributions of birthdates, suggesting intrauterine aetiological factors, have been found in several psychiatric disorders, including one study of out-patients with Seasonal Affective Disorder (S.A.D.). We investigated birthdate distribution in relation to seasonal changes in well-being among a cohort who had completed the Seasonal Pattern Assessment Questionnaire (SPAQ). Method: A sample of 4904 subjects, aged 16 to 64, completed the SPAQ. 476 were cases of S.A.D. on the SPAQ and 580 were cases of sub-syndromal S.A.D. (S-S.A.D.). 92 were interview confirmed cases of S.A.D. Months and dates of birth were compared between S.A.D. cases and all others, between S.A.D. and S-S.A.D. cases combined and all others, and between interview confirmed cases and all others. Seasonality, as measured through seasonal fluctuations in well-being on the Global Seasonality Scores (GSS) of the SPAQ, was compared for all subjects by month and season of birth. Results: There was no evidence of an atypical pattern of birthdates for subjects fulfilling criteria for S.A.D., for the combined S.A.D. / S-S.A.D. group or for interview confirmed cases. There was also no relationship between seasonality on the GSS and month or season of birth. Limitations: Diagnoses of S.A.D. made by SPAQ criteria are likely to be overinclusive. Conclusion: Our findings differ from studies of patients with more severe mood disorders, including psychiatric out-patients with S.A.D. The lack of association between seasonality and birthdates in our study adds credence to the view that the aetiology of S.A.D. relates to separable factors predisposing to affective disorders and to seasonality

Sustainable sorbitol dehydration to isosorbide using solid acid catalysts: transition from batch reactor to continuous flow system

Isosorbide is one of the most interesting cellulosic-derived molecules with great potential to be implemented in wide range of products that shaping our daily life. This minireview describes the recent developments in the production of isosorbide from sorbitol in batch and continuous flow systems under hydrothermal conditions using solid acid catalysts. Moreover, we are summarizing the current hurdles and challenges that facing the synthesis of isosorbide from cellulosic biomass in continuous flow process using solid acid catalysts, as well as the scaling up of this process into pilot level, which will lead to an established industrial process with high sustainability metrics

A Novel Cooperative Controller for Inverters of Smart Hybrid AC/DC Microgrids

This paper presents a novel cooperative control technique concerning fully-distributed AC/DC microgrids. Distributed generation based on inverters has two types, i.e., Current Source Inverter (CSI), also referred to as PQ inverter, and Voltage Source Inverter (VSI). Both inverter forms have a two-layer coordination mechanism. This paper proposes a design method for the digital Proportional-Resonant (PR) controller that regulates the current inside an inverter. The inverters will improve the voltage quality of the microgrid while maintaining the average voltage of buses at the same desired level. There is comprehensive detail on the computations specific to resonant and proportional gains and digital resonance path coefficients. The paper includes a digital PR controller design and its analysis in the frequency domain. The analysis is based on the w-domain. The main contribution of this paper is the proposed method, which not only focuses on the transient response but also improves the steady-state response which smoothens the voltage; furthermore, all inverters are effectively involved to increase the capacity of the microgrid for better power management. The suggested cooperative control technique is used on an IEEE 14-bus system having fully distributed communication. The convincing outcomes indicate that the suggested control technique is an effectual means of regulating the microgrid’s voltage to obtain an evener and steady voltage profile. The microgrid comprises distributed resources and is used as the primary element to analyse power flow and quality indicators associated with a smart grid. Lastly, numerical simulation observations are utilised for substantiating the recommended algorithm

Controlled lignosulfonate depolymerization via solvothermal fragmentation coupled with catalytic hydrogenolysis/hydrogenation in continuous flow reactor

Sodium lignosulfonate (LS) was valorized to low molecular weight (Mw) fractions by combining solvothermal (SF) and catalytic hydrogenolysis/hydrogenation fragmentation (SHF) in continuous flow system. This achieved in either alcohol/water (EtOH2O or MeOH/H2O) as a solvent and Ni on nitrogen-doped carbon as a catalyst. The tunability according to temperature of both SF and catalytic SHF of LS has been separately investigated at 150°C, 200°C and 250°C. In SF, the minimal Mw was 2994 g mol-1 at 250°C with a dispersity (Đ) of 5.3 using MeOH/H2O. In catalytic SHF using MeOH/water, extremely low Mw was found (433 mg gLS-1) with Đ of 1.2 combined with 34 mg gLS-1. The monomer yield was improved to 42 mg gLS-1 using dual catalytic beds. These results is a direct evident that lignin is an unstable polymer at elevated temperature and could be efficiently deconstructed in hydrothermal conditions with and without catalyst

Text Classification for Arabic Words Using Rep-Tree

The amount of text data mining in the world and in our life seems ever increasing and there’s no end to it. The concept (Text Data Mining) defined as the process of deriving high-quality information from text. It has been applied on different fields including: Pattern mining, opinion mining, and web mining. The concept of Text Data Mining is based around the global Stemming of different forms of Arabic words. Stemming is defined like the method of reducing inflected (or typically derived) words to their word stem, base or root kind typically a word kind. We use the REP-Tree to improve text representation. In addition, test new combinations of weighting schemes to be applied on Arabic text data for classification purposes. For processing, WEKA workbench is used. The results in the paper on data set of BBC-Arabic website also show the efficiency and accuracy of REP-TREE in Arabic text classification

On Existence and Uniqueness Theorem Concerning Time–Dependent Heat Transfer Model

In this article we consider a physical model describing time-dependent heat transfer by conduction and radiation. This model contains two conducting and opaque materials which are in contact by radiation through a transparent medium bounded by diffuse-grey surfaces. The aim of this work is to present a reliable framework to prove the existence and the uniqueness of a weak solution for this problem. The existence of the solution can be proved by solving an auxiliary problem by the Galerkin-based approximation method and Moser-type arguments which implies the existence of solution to the original problem. The uniqueness of the solution will be proved by using the same approach in our previous work for the stationary heat transfer model and some ideas from nonlinear heat conduction analysis

Counterions at Charged Cylinders: Criticality and universality beyond mean-field

The counterion-condensation transition at charged cylinders is studied using Monte-Carlo simulation methods. Employing logarithmically rescaled radial coordinates, large system sizes are tractable and the critical behavior is determined by a combined finite-size and finite-ion-number analysis. Critical counterion localization exponents are introduced and found to be in accord with mean-field theory both in 2 and 3 dimensions. In 3D the heat capacity shows a universal jump at the transition, while in 2D, it consists of discrete peaks where single counterions successively condense.Comment: 4 pages, 3 figures; submitted to Phys. Rev. Lett. (2005

The effects of phytoestrogens Matricaria recutita on growth, maturation of oocytes in the three spot gourami (Trichogaster trichopterus)

Chamomile is a rich source of phytoestrogens; these compounds have antioxidant, anticancer. In this study, the effects of chamomile on growing oocytes in immature female gourami fish were examined. Thus 60 immature female gourami fish with an average weight of 2-3 g of 6-treated group were analyzed. Treatments in a completely randomized experimental design with a dose of chamomile (10-20-30-50 mg/kg fish) along with control (no injection) and ethanol control (solvent injection) and with three replicates were tested. The fish adaptation to the environment lasted 3 days. The extract injections were done for 20 days, in 10 periods, every other day. In order to histological study, three days after end of the experiment, the ovarian tissue was removed and weighed, tissue processing and staining steps done with hematoxylin- eosin. At last the histological structure of the ovaries and the average percentage of treated fish gonadal indices were compared with the control group. According to our results of gonadal index, there was no significant difference between the control groups with receiving Ethanol (p>0.05). Histological results showed that increasing the dose of chamomile extract accelerate oocyte maturation in three spot gourami. This is the fourth treatment (dose, mg / kg 50) to show its obvious. The difference between oocyte diameter was observed with increasing doses of Chamomile and in comparison with the control group, the difference was significant (p <0.05). Histological results showed that increasing the dose of Chamomile accelerate oocyte maturation in three spot gourami