Existence and numerical approximation of a solution to frictional contact problem for electro-elastic materials

In this paper,a frictional contact problem between an electro-elastic body and an electrically conductive foundation is studied.The contact is modeled by normal compliance with finite penetration and a version of Coulomb’s law of dry friction in which the coefficient of friction depends on the slip.In addition,the effects of the electrical conductivity of the foundation are taken into account.This model leads to a coupled system of the quasi-variational inequality of the elliptic type for the displacement and the nonlinear variational equation for the electric potential.The existence of a weak solution is proved by using an abstract result for elliptic variational inequalities and a fixed point argument.Then,a finite element approximation of the problem is presented.Under some regularity conditions,an optimal order error estimate of the approximate solution is derived.Finally,a successive iteration technique is used to solve the problem numerically and a convergence result is established.

Contraceptive Continuation, Pregnancy and Abortion Rate Two Years after Post Abortion Counselling

Objectives: To estimate the contraceptive use rate, pregnancy and abortion rate two years after post abortion counselling. Methods: In this current paper we conducted a cross-sectional study from September to December 2011 among women who participated of original randomized trial. In this study 118 women who had been allocated in the group that received the personalized contraceptive counselling and 103 women who had been allocated in the group that received standard counselling service were contacted by phone. The analyzed variables were the use of contraceptive methods, reasons for not using them, satisfaction in used method, and occurrence of pregnancy and abortion. Results: The pregnancy rate was lower in the personalized counselling group (p = 0.022), whereas abortion (p = 0.543) and contraceptive use rate (p = 0.270) had no difference between groups. The overall contraceptive use rate was high in both groups and the injectable method use rate was higher in personalized counselling group (p?= 0.004). Conclusions: Two years after the intervention the pregnancy rate was lower in personalized counselling group. The contraceptive use rate had no difference between the groups, except for the injectable which the use rate was higher in the personalized counselling group. These results could be encouraging because the intervention improved the uptake of one of the long-acting methods of contraception.

Nonsingle-valley Continuous Solutions of p-order Feigenbaum's Functional Equation

The author considers the Feigenbaum's functional equation fp(λx) = λf(x) for each p > 2. The existence of nonsingle-valley continuous solutions to this equation is discussed and a feasible method to construct such solutions is given.

RADIATION EFFECTS ON SOME PHYSICO-BIOCHEMICAL CHANGES IN PISUM SATIVUM

Effect of irradiation treatment (0.5, 1.0, 2.0 and 4.0 kGy) on fresh pea cultivars was investigated. Results indicated that significant decrease in colour (% transmittance) and ascorbic acid occurred due to storage period. Higher irradiation treatments showed a significant difference in colour retention in both the cultivars. Visual observation indicated no sprouting until 6th days after which sprouting started in both the cultivars irrespective of radiation treatments. At higher irradiation dose (4.00 kGy) sprouts died soon after emergence. Peas irradiated at 2.0-4.0 kGy doses showed rottage after 9-12 days of storage in both the varieties. Higher irradiation doses enhanced the rate of rot compared with lower doses, p-8 was more resistant to rottage than Moon cultivar of pea.

Techniques for Determining the Treatment Costs of Cervical Cancer: A Systematic Review

Background: Uterine cervical cancer (UCC) represents a public health problem in many part of the world. The use of new technologies is leading to increased treatment costs, resulting in a substantial economic impact worldwide. Standardization of economic evaluation methods is needed to improve comparisons between jurisdictions. Objective: To identify the methods used to measure the cost of treating invasive UCC, and to search for correlations between cancer treatment expenditures and local economies. Methods: We searched articles in MEDLINE, LILACS, and SciELO with no language restrictions, and included publications from January 01, 2007 to December 31, 2016. Studies were included if they described the annual direct cost of invasive cervical cancer and detailed the costing method. Complete economic evaluations were excluded. Results were described in 2016 international dollars. Results: Of 1581 studies initially reviewed, 13 articles were included in the analysis. Six articles used a bottom-up;six used a top-down approach and one used both. Annual cost per patient varied from I$ 2146.22 (Poland) to 34,351.54 (Sweden). Middle-income countries (MIC) spent median 72.52% of its GDP per capita on the treatment of invasive cervical cancer, while high-income countries (HIC) spent median 30.12% (p = 0.032). No significant difference was found when separated by costing method. Conclusions: We found that, for the treatment costs of invasive UCC, the percentages of GDP per capita were statistically higher in MIC than in HIC. However, no significant difference was found between costing methods, and the top-down approach could be used.

不同上部刚度对木框架剪力墙受力性能影响的试验研究

木框架剪力墙试验研究时,荷载传递梁的刚度对木框架剪力墙的破坏模式以及侧向荷载承载力有直接的影响,当木框架剪力墙墙端以及墙中洞口边未采用墙端锚栓时,这种影响更甚。当墙顶连接铰接荷载传递梁时,在水平荷载作用下,木框架剪力墙的墙端易于被上拔而与墙基础分离,此时试验所得到的木框架剪力墙的侧向荷载承载力接近于下限值;反之,刚性荷载传递梁所得到的木框架剪力墙的侧向荷载承载力接近于上限值。主要通过22片墙体的试验研究来了解上层墙体、楼盖刚度对下层木框架剪力墙受力性能的影响。其中16片为6m长2.44m高的单层足尺木框架剪力墙,墙顶一半采用铰接荷载传递梁一半采用刚性荷载传递梁,4片为足尺典型二层墙体,另外2片为增加了墙端锚栓的单层足尺木框架剪力墙。对试验结果从初始刚度、极限荷载、极限位移、能量耗散以及锚栓内力等方面进行分析,最后形成了采用刚性荷载传递梁和二层墙体均能增加墙体侧向荷载承载力的结论。

生物质甲醛捕捉剂的应用与进展

甲醛捕捉剂是人造板生产和应用中的一种重要助剂,使用甲醛捕捉剂可以有效降低游离甲醛释放而提高人造板品质。本文详细介绍了国内外以树皮、茶叶、蛋白质、某些中药材、天然樟科植物提取物等物质为主剂,制备的生物质基甲醛捕捉剂的研究、应用状况,概述了生物质甲醛捕捉剂的主要活性成分以及甲醛捕捉机制。

苯酚液化落叶松全树皮胶粘剂的制备

树皮是一种丰富的可再生天然高分子材料,随着石油资源的日趋短缺,研究并合理利用树皮制备高分子材料具有积极意义。首先在复合酸存在下采用高温苯酚液化法将落叶松全树皮进行液化处理,然后以此作为部分苯酚的替代物,制备耐水环保型树皮胶(即苯酚液化落叶松全树皮-甲醛胶粘剂)。重点研究了不同加碱次数对树皮胶主要性能的影响。结果表明:加碱次数对树皮胶的理化性能影响较大;采用2次加碱工艺制成的树皮胶具有相对最好的综合性能,其胶接性能及游离甲醛释放量均与纯酚醛树脂(PF)胶相当;苯酚液化落叶松全树皮对苯酚的替代量达到30%,但所得系列树皮胶的储存期较短。

热磨条件对麦秸中密度纤维板性能的影响

在不同的热磨条件下(蒸汽压力为0.4、0.6、0.8、1.0MPa,磨盘转数为2 500r/min和3 000r/min),将麦秸原料分离成纤维,并试制了相应的麦秸中密度纤维板,对比分析了不同的热磨条件对麦秸中密度纤维板的内结合强度、弯曲性能、吸水性能、表面硬度和边部握螺钉力的影响。结果表明,不同的热磨条件下分离得到的麦秸纤维形态存在差异,纤维的强度和形态对麦秸中密度纤维板的物理力学性能影响较大。当蒸汽压力为0.8MPa,磨盘转数为3 000r/min,麦秸中密度纤维板的各项性能得刮改善。

低n_F/n_M三聚氰胺-甲醛低聚物对脲醛树脂性能的影响

采用自制的可溶性三聚氰胺-甲醛低聚物作为脲醛树脂的添加剂,通过DSC及压制胶合板等方法评价该低聚物对脲醛树脂的固化特性、游离甲醛释放量和胶合强度的影响。结果表明,对于nF/nU为1.1的脲醛树脂UF1,随着三聚氰胺-甲醛低聚物加入量的增加,树脂固化活化能和胶合板的甲醛释放量都呈现先降低后增加的趋势,而胶合强度变化趋势不明显。对于nF/nU为1.2的脲醛树脂UF2,随着三聚氰胺-甲醛低聚物加入量的增多,树脂固化活化能先增加后降低;胶合板甲醛释放量逐渐降低;干强度变化趋势不明显,湿强度先降低后增加。方差分析表明,脲醛树脂的物质量比对胶合板性能的影响更为明显。

木材加工用耐水性苯酚液化树皮-甲醛胶粘剂的研制

树皮是一种来源丰富可再生的天然高分子材料。本文采用高温苯酚液化的方法,在复合酸存在下将落叶松全树皮液化成为木材胶粘剂的原料。研究了树皮液化产物制备木材胶粘剂的合成工艺,特别是碱用量对苯酚液化落叶松全树皮-甲醛胶粘剂各主要性能的影响。结果表明,增加碱用量会缩短树皮胶的贮存期,但可降低胶中的游离甲醛;通过降低树皮胶合成时的终点黏度,并在合成末期用水稀释,可有效提高树皮胶的适用期,并可确保树皮胶具有很好的胶接强度和耐水性、较快的固化速率以及很低的游离甲醛释放量。

氟碳丙烯酸合成树脂乳液在外墙涂料中的应用

简述了氟碳丙烯酸乳液的发展趋势 ,提出设计构想 ,分析了不同氟含量的丙烯酸乳液的性能 ,指出抗沾污性涂层是近期市场发展的需求。

全球生活用纸市场发展现状及未来趋势

生活用纸市场在全球造纸工业市场中连续多年持续平稳发展,据统计,2020年全球生活用纸消费量约为4,296万t,较2019年增长6.1%[1]。2021年生活用纸的行业市值约为765.2亿美元,预计2022年为809.9亿美元,到2029年增长为1,247.4亿美元,2022~2029年间生活用纸市场年均增长率为6.4%。生活用纸市场的增长得益于新兴国家经济体的快速发展,人民生活水平的提高使得丰富多样的生活用纸产品广泛涌入人们的日常生活中。另外,世界人口以每年略高于1%的速度增长,从2022年到2025年世界人口将增加近10亿,预计生活用纸市场也会实现同步增长[2]。

Exponential Dichotomy and Eberlein-Weak Almost Periodic Solutions

We give sufficient conditions ensuring the existence and uniqueness of an Eberlein-weakly almost periodic solution to the following linear equation dx/dt(t) = A(t)x(t) + f(t) in a Banach space X, where (A(t)) t ∈□ is a family of infinitesimal generators such that for all t ∈□, A(t + T) = A(t) for some T > 0, for which the homogeneuous linear equation dx/dt(t) = A(t)x(t) is well posed, stable and has an exponential dichotomy, and f:□ →X is Eberlein-weakly amost periodic.

RADIATION OR WAXING EFFECT ON SHELF LIFE OF GUAVA FRUIT

Red and white guavas were treated with wax emulsion or irradiation (0.25-2.0 kGy) and kept for 12 days at room temperature. Initiation of rot attack occurred after 3 days which increased significantly during further storage. In the waxed fruits rottage, weight loss and vitamin loss were significantly less than controls and irradiated ones. Sensory scores decreased with storage time and they ranged 3.7-4.5, 2.1-3.9 and 2.3-2.7 in waxed, radiated and untreated controls respectively, after 12 days storage. Waxing was found to increase the. shelf life of this fruit for 3-4 d while irradiation exhibited no beneficial effects.

Chemically modified carbon-based electrodes for the determination of paracetamol in drugs and biological samples

Paracetamol is a non-steroidal, anti-inflammatory drug widely used in pharmaceutical applications for its sturdy, antipyretic and analgesic action. However, an overdose of paracetamol can cause fulminant hepatic necrosis and other toxic effects. Thus, the development of advantageous analytical tools to detect and determine paracetamol is required. Due to simplicity, higher sensitivity and selectivity as well as costefficiency, electrochemical sensors were fully investigated in last decades. This review describes the advancements made in the development of electrochemical sensors for the paracetamol detection and quantification in pharmaceutical and biological samples. The progress made in electrochemical sensors for the selective detection of paracetamol in the last 10 years was examined, with a special focus on highly innovative features introduced by nanotechnology. As the literature is rather extensive, we tried to simplify this work by summarizing and grouping electrochemical sensors according to the by which manner their substrates were chemically modified and the analytical performances obtained.

Stretchable Strain Sensors Fabricated by Screen Printing of Silver Paste on the Surface Modified Transparent Elastomeric Polyurethane Films

Strain sensors for human-motion detection must offer high stretchability, high sensitivity, fast response, and high recovery speed. In this study, we choose silver paste as a sensing material and use a screen printing method to fabricate the strain sensor based upon an electrical-resistance mechanism. After curing elastomeric polyurethane film with a thickness of 150 μm on PET film, the polyester resin mixed with blocked isocyanate curing agent was coated as a masking layer to reduce the film’s stickiness. The effect of the polyester masking layer upon the silver paste screen printing process was examined using a rolling-ball-tack test, TGA analysis of polyester resins, and cured silver-electrode films. The cost-effective strain sensor fabricated by using silver paste and screen printing processes on the stretchable-polyurethane-substrate film showed high sensitivity and fast response in a strain range of up to 100%.

Deep Learning Enabled Disease Diagnosis for Secure Internet of Medical Things

In recent times,Internet of Medical Things(IoMT)gained much attention in medical services and healthcare management domain.Since healthcare sector generates massive volumes of data like personal details,historical medical data,hospitalization records,and discharging records,IoMT devices too evolved with potentials to handle such high quantities of data.Privacy and security of the data,gathered by IoMT gadgets,are major issues while transmitting or saving it in cloud.The advancements made in Artificial Intelligence(AI)and encryption techniques find a way to handle massive quantities of medical data and achieve security.In this view,the current study presents a new Optimal Privacy Preserving and Deep Learning(DL)-based Disease Diagnosis(OPPDL-DD)in IoMT environment.Initially,the proposed model enables IoMT devices to collect patient data which is then preprocessed to optimize quality.In order to decrease the computational difficulty during diagnosis,Radix Tree structure is employed.In addition,ElGamal public key cryptosystem with Rat Swarm Optimizer(EIG-RSO)is applied to encrypt the data.Upon the transmission of encrypted data to cloud,respective decryption process occurs and the actual data gets reconstructed.Finally,a hybridized methodology combining Gated Recurrent Unit(GRU)with Convolution Neural Network(CNN)is exploited as a classification model to diagnose the disease.Extensive sets of simulations were conducted to highlight the performance of the proposed model on benchmark dataset.The experimental outcomes ensure that the proposed model is superior to existing methods under different measures.

Hidden Information, Energy Dispersion and Disorder: Does Entropy Really Measure Disorder?

Despite its appearance in physics around the 1850th, the second law of thermodynamics is still attracting more efforts to be clarified. More specifically, fifteen years later (1865) after its definition and introduction, entropy has been the subject of various interpretations. Hence, in physical sciences and notably in different education levels, its concept seems to be relatively tough to unambiguous decipher. In this work, we re-introduce the notion of entropy from classical, quantum and information theories viewpoints. The controversial over entropy and a measure of disorder misconception, stated by many scientists, is addressed as well to come up with less confusing physical interpretation of entropy. Hence, over time, an increase of entropy, a quantitative quantity, is most often associated to a rising of disorder, a non-quantitative quantity and no value-returning mathematical equation, rather than a continuously increasing of hidden data. In other words, linking disorder to hidden data is typically raising more confusion than clarification. Here, we shed more light on both concepts to find out an acceptable interpretation of entropy.

p-order Feigenbaum's Maps

A continuous map f from the unit closed interval into itself is called a p-order Feigenbaum's map if fp(λx) = λf(x),f(O)=1 and f|[λ,1] is univallecular. In this paper, some characterizations of p order Feigenbaum's maps are discussed and the existence for both types of such maps is proven.