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The paper considers elastic contact of rough surfaces and develops a simple analytical expression for the stiffness of the contact under tangential loading, which predicts that the contact stiffness is proportional to normal load and independent of Young's Modulus. The predictions of this model are compared to a full numerical analysis of a rough elastic contact of finite size. The two approaches are found to be in good agreement at low loads, when the asperity spacing is large, but the numerical approach predicts much lower stiffnesses at medium and high loads. It is shown that the overall stiffness cannot exceed that of the equivalent smooth contact, and a simple means of modifying the analytical approach is proposed and validated. [ABSTRACT FROM AUTHOR]

This paper reviews some of the modelling and experimental techniques recently employed by the authors for the analysis of the macro- and mesoscopic behaviour of polycrystalline aggregates. A joined-up approach is used for assessing the deformation behaviour of polycrystalline materials at the macroscopic and grain levels, based on combining modelling using the crystal plasticity finite element (CPFE) method with experimental characterization by in situ loading and continuous lattice strain measurement by diffraction. The complementarity of the two methodologies is emphasized, as it helps to improve understanding of the physics underlying inelastic deformation, damage mechanisms, and fatigue crack initiation. The proposed approach is part of the attempt to develop a general framework that will enable reliable and accurate determination of the inhomogeneous fields of plastic strain, the regions of localized plasticity, and intergranular residual stresses. Examples are given of microscopically calibrated CPFE simulations being used to match the experimentally observed evolution of lattice stresses and strains in advanced structural alloys of industrial interest. [ABSTRACT FROM AUTHOR]

Using the Atzori–Lazzarin criterion, the first author has recently proposed a unified model for fretting fatigue (FF), called the crack-like notch analogue (CLNA) model. Two possible types of behaviour were suggested: either ‘crack-like’ or ‘large blunt notch,’ and these are immediately studied in the typical condition of constant normal load and in phase oscillating tangential and bulk loads. The former condition (‘crack-like’) was treated by approximating the geometry to the perfectly flat one of the crack analogue (CA), improved in some details, reducing all possible geometries to a single contact problem. The latter (‘large blunt notch’), with a simple peak stress condition i.e. a simple notch analogue model. In the present paper, the calculation of the ‘crack-like’ behaviour is improved using the recent asymptotic characterisation developed by Dini, Hills and Sackfield, which extracts the asymptotic singular stress field of the fretting contact. A significant difference is found in the ‘equivalent’ geometric factor obtained for the Hertzian geometry, particularly near full sliding, where the new criterion is more conservative, but still not large enough to permit to find, for example in Nowell's FF experimental data, if the refinement is an improvement of predictive capabilities. In flatter geometries, the difference is expected to be even smaller than in the case of the Hertzian geometry, and in this case, the original CLNA model, for its simplicity, remains a very convenient simple closed form criterion. [ABSTRACT FROM AUTHOR]

Abstract: The problem of indentation of a half-plane by a titled, shallow wedge, under frictionless conditions, is studied, using half-plane theory. The contact law itself, together with the pressure distribution and internal state of stress are found. Particular attention is then given to the nature of the pressure and state of stress at the apex, and an asymptotic form appropriate to all angular features within contacts, and therefore of widespread application, is introduced. [Copyright &y& Elsevier]

The study aimed to know the use of Skit Technique to increase students’ selfconfidence in speaking English. Speaking is one of important skills in English. Self-Confidence is really need to speak in English. Someone needs self-confidence to express their idea and their feelings in a foreign language especially in English. Not all of the people have good self-confidence in using English to express or to share their idea and their opinion. The aim of this study is to know whether the Skit Technique can increase self- confidence in speaking English. In other words Skit Technique can help to increase self-confidence in speaking English. The design of this research is experiment. The population of the research is 46 students at the eight grade students of MTs Darul Ihsan Duri. The sample technique is random sampling. From the data, it can be seen that Ttable < Tvalue (2.101 < 12.466). It means Ha is accepted and Skit Technique done in experiment class.

Penelitian ini menunjukkan bahwa ada perbedaan kemampuan berbicara siswa antara kelompok kontrol engan kelompok eksperimen.Sebelum menggunakan Power Teaching Strategy nilai rata-rata siswa adalah 53.64 setelah menggunakan Power Teaching Strategy nilai rata-rata siswa adalah 78.00. Dapat disimpulkan bahwa t-diperoleh 2.73 pada tingkat signifikansi α = 0.05 dan derajat kebebasan (df) 94 yang diperoleh dari N-1,t-kritis adalah 1.98. T-diperoleh lebih tinggi dari t-kritis. Dengan demikian dapat disimpulkan bahwa ada efek yang signifikan antara kemampuan berbicara siswa kelas delapan M.Ts Hubbulwathan Duri setelah menggunakan Power Teaching Strategy.

Currently, the practices of mafia of law in Indonesia is getting more rampant. Law enforcement is very slow, many cases of corruption offenses as crimes extra ordinary crime are addressed will slow grind lower law. Ineffective of law in Indonesia is also dependent on these factors. Primarily extraordinary people. Several law enforcement officials are easily bribed by corrupt actors with the aim to escape punishment, or lighten their sentences. Laws are formulated to deal with corruption seem barren. Factually Indonesia show that is still ranked below Malaysia, Singapore, and Hong Kong, as well as Vietnam and the Philippines. Outcome in the form of impacts and benefits of combating corruption unclear to this day. This paper will to describe that law enforcement combating corruption will be support by extra ordinary measure and extra ordinary people. Especially, Indonesia, a majority Muslim country in fact the largest Muslim country in the world, a large number of Islam is really potential become a leader in the combating corruption. *** Praktek mafia hukum di Indonesia saat ini lebih merajalela. Penegakan hukum saat ini sangat lambat, banyak kasus tindak pidana korupsi sebagai ke­jahatan extra ordinary ditangani lambat laun akan menggiring hukum yang lebih rendah. Tidak efektifnya hukum di Indonesia tergantung juga pada faktor-faktor ini: pejabat penegak hukum yang mudah disuap oleh pelaku korupsi dengan tujuan untuk menghindari hukuman, atau meringankan hukuman mereka; hukum yang diformulasikan untuk menangani korupsi tampaknya mandul. Secara faktual Indonesia masih berada di bawah peringkat Malaysia, Singapura, dan Hong Kong, serta Vietnam dan Filipina dalam hal penanganan korupsi. Tulisan ini akan menjelaskan bahwa penegakan hukum dalam pemberantasan korupsi mem­butuhkan dukungan dengan tindakan luar biasa dan orang luar biasa. Terutama Indonesia, yang mayoritas penduduknya Muslim benar-benar potensial bagi kelahiran pemimpin yang mampu memerangi korupsi.

Motivasi merupakan faktor yang sangat penting dalam proses pembelajaran bahasa Inggris, karena bagi sebagian siswa bahasa Inggris merupakan pelajaran yang tidak penting dan juga menakutkan sehingga mereka tidak memiliki keinginana atau kesadaran untuk belajar bahasa Inggris. Pada dasarnya bahasa Inggris merupakan pelajaran yang sangat bermanfaat bagi setiap individu khususnya peserta didik. oleh karena itu sangat diperlukan motivasi agar siswa tersebut menyadari bahwa setiap mereka memilki potensi untuk memiliki kemampuan bahkan menguasai bahasa Inggris.

Background: Low back pain is one of the global health issues which prevalence is high among productive ages. It oftentimes corresponds with one’s physical activity during work . The purpose of this study was to determine theprevalence and characteristics of low back pain among productive age population in Jatinangor, West Java, Indonesia. Methods: This study was a cross-sectional descriptive study conducted during the period of August to October 2014 in the three villages in Jatinangor, West Java, Indonesia. In order to determine the demographic data and history of low back pain in the last three months, about 1075 productive age populations were selected through validated questionnaire as the secondary data. These data consisting of 310 subjects were then described according to the pain characteristics and physical activity during work. Results: During three months of examination, s the prevalence of low back pain was 38.4%, with the average age 50–59 years old. Furthermore, about 22.3% subjects were indicated chronic low back pain. The most prevalent qseverity of the pain was dull pain (29.4%), followed with pins and needles pain (23.1%), As the intensity of the pain increased, there was a tendency of increasing interference in daily activities. Static posture was also the most frequent physical activity during work (53.2%). Conclusions: The prevalence of low back pain is more than one third (38.4%) among productive age populations in Jatinangor, West Java, Indonesia.

Dalam pendidikan kedudukan Ilmu pengetahuan, Moral dan Agama merupakan faktor-faktor yang saling mempengaruhi berhasil atau tidaknya pendidikan. Hal ini disebabkan karena setiap point memiliki kedudukan masing-masing dan nilai-nilai yang tidak dapat dipisahkan satu sama lain.

In this work we study the influence of fluid viscoelasticity on the performance of lubricated contacts in the presence of cavitation. Several studies of viscoelastic lubricants have been carried out, but none of them have considered the possibility of the presence of cavitation. To describe the effect of viscoelasticity, we use the Oldroyd-B model. By assuming that the product between ϵ , i.e. the ratio between vertical and horizontal length scales, and the Weissenberg number (Wi), i.e. the ratio between polymer relaxation time and flow time scale, is small, we can linearise the viscoelastic thin film equations, following the approach pioneered by "Tichy, J., 1996, Non-Newtonian lubrication with the convected Maxwell model." Consequently, the zeroth-order in ϵWi corresponds to a Reynolds equation modified to describe also the film cavitation through the mass-conserving Elrod-Adams model. We consider the flow of viscoelastic lubricants using: (i) a cosine profile representing a journal bearing unwrapped geometry, and (ii) a pocketed profile to model a textured surface in lubricated contacts. The introduction of viscoelasticity decreases the length of cavitated region in the cosine profile due to the increasing pressure distribution within the film. Consequently, the load carrying capacity increases with Wi by up to 50% in the most favorable condition, confirming the beneficial influence of the polymers in bearings. On the other hand for the pocketed profile, results show that the load can increase or decrease at higher Wi depending on the texture position in the contact. The squeeze flow problem between two plates is also modeled for viscoelastic lubricants considering an oscillating top surface. For this configuration a load reduction is observed with increasing Wi due to the additional time needed to reform the film at high Wi. Furthermore, if viscoelastic effects increase, the cavitation region widens until reaching a value of Wi for which a full-film reformation does not occur after the initial film rupture. • First attempt to introduce cavitation in models of viscoelastic lubricants. • Viscoelasticity diminishes the non-active region enhancing the load in bearings. • Viscoelasticity can improve the performance of textured surfaces. • In oscillatory squeezing viscoelasticity hinders the film reformation. [ABSTRACT FROM AUTHOR]

Brain tissue is a heterogeneous material, constituted by a soft matrix filled with cerebrospinal fluid. The interactions between, and the complexity of each of these components are responsible for the non-linear rate-dependent behaviour that characterises what is one of the most complex tissue in nature. Here, we investigate the influence of the cutting rate on the fracture properties of brain, through wire cutting experiments. We also present a computational model for the rate-dependent behaviour of fracture propagation in soft materials, which comprises the effects of fluid interaction through a poro-hyperelastic formulation. The method is developed in the framework of finite strain continuum mechanics, implemented in a commercial finite element code, and applied to the case of an edge-crack remotely loaded by a controlled displacement. Experimental and numerical results both show a toughening effect with increasing rates, which is linked to the energy dissipated by the fluid–solid interactions in the region surrounding the crack tip. [ABSTRACT FROM AUTHOR]

Penelitian ini bertujuan untuk mengurangi kecemasan siswa berbahasa Inggris; Penulis melakukan penelitian survei yang desain akan digunakan untuk menlihat tentang kecemasan siswa dalam berbahasa Inggris. penelitian ini di lakukan pada semester VI STAI Hubbulwathan pada bulan April sampai September. Masalah yang ditemukan di dalam penelitian ini adalah mahasiswa kecemasan mahasiswa untuk berbicara bahasa Inggris di dalam kelas. Untuk menjawab permasalahan penulis memberikan kuesioner dan wawancara untuk mengetahui adakah penyebab kecemasan tersebut. Hasil penelitian menunjukkan bahwa (1) siswa dapat berbicara bahasa Inggris di dalam kelas. (2) Para siswa mendapatkan informasi tentang masalah kecemasan mereka untuk berbicara bahasa Inggris di dalam kelas. Kesimpulan dari penelitian ini adalah guru dapat memberikan sebagai stimulus untuk merangsang motivasi siswa untuk terlibat dalam pelajaran. sehingga guru dapat mengembangkan kegiatan belajar yang menyenangkan dan mempromosikan siswa percaya diri.

Nasopharyngeal malignancy is the most commonly found among head and neck malignancies. Generally, nasopharyngeal cancer, has a good prognosis if it is detected as soon as possible. It is very important to diagnose it earlier because survival rate can be longer if therapy is given early. This study aims to determine the diagnostic value of clinical scores compared with histopathology biopsy to diagnose nasopharyngeal carcinoma in patients of RSUD Ulin Banjarmasin in the period 2012-2014. Subjects of this study were patients of RSUD Ulin Banjarmasin Hospital which is suspected nasopharyngeal carcinoma, who have examined the clinical symptoms by history and physical examination, had been registered in the medical record, and had been examined with histopathology biopsy. Data of clinical examination and histopathology biopsy from each sampel were collected for clinical symptom scores were analyzed according to get sensitivity value, specifity value, positif predictive value, and negative predictive value.Total subject of this research was 30. In this study, a minimum clinical score to lead to a nasopharyngeal malignancy that if found clinical score of 4, with a sensitivity, specifity, positive predictive value , and negative predictive value of 75%, 83.33%, 94.74%, 45.45% respectively. Clinical characteristics have high sensitivity and specifity to diagnose nasopharyngeal carcinoma. Keywords: diagnostic value, clinical scores, nasopharyngeal carcinoma

Penelitian ini bertujuan untuk meningkatkan aktivitas guru, kinerja, dan kemampuan berpikir kritis siswa pada materi Sistem Ekskresi di kelas XIIPA3 SMA Negeri 1 Kota Bengkulu dengan menerapkan model Pembelajaran Berbasis Masalah. Penelitian ini merupakan penelitian tindakan kelas yang dilakukan dalam dua siklus. Masing-masing siklus terdiri dari 4 tahap yaitu : tahap perencanaan, pelaksanaan, pengamatan dan refleksi. Subjek penelitian ini adalah guru dan seluruh siswa kelas XIIPA3 SMA Negeri 1 Kota Bengkulu yang berjumlah 33 orang. Metode yang digunakan adalah metode deskriptif. Teknik pengumpulan data aktivitas guru dan kinerja siswa adalah teknik observasi, menggunakan lembar observasi aktivitas guru dan lembar observasi penilaian kinerja. Adapun teknik yang digunakan untuk mengumpulkan data kemampuan berpikir kritis yaitu tes tertulis menggunakan lembar tes berpikir kritis. Hasil penelitian menunjukkan adanya peningkatan aktivitas guru, kinerja dan kemampuan berpikir kritis siswa. Rata-rata skor aktivitas guru pada siklus I yaitu 28 (baik) meningkat di siklus II menjadi 30 (baik). Kinerja siswa mengalami peningkatan yaitu pada siklus I 57,25% dengan kriteria cukup pada siklus II meningkat menjadi 72,5% dengan kriteria baik. Hasil kemampuan berpikir kritis pada siswa di siklus I memperoleh persentase klasikal 59,39% dengan kriteria cukup kritis, di siklus II meningkat menjadi 73,33% dengan kriteria kritis. Dapat disimpulkan bahwa penerapan model pembelajaran berbasis masalah dapat meningkatkan aktivitas guru, kinerja dan kemampuan berpikir kritis siswa pada materi sistem ekskresi di kelas XIIPA3 SMA Negeri 1 Kota Bengkulu. Kata kunci: Pembelajaran Berbasis Masalah, Kinerja dan Kemampuan berpikir kritis, Biologi SMA

Our sense of fine touch deteriorates as we age, a phenomenon typically associated with neurological changes to the skin. However, geometric and material changes to the skin may also play an important role on tactile perception and have not been studied in detail. Here, a finite element model is utilised to assess the extent to which age-related structural changes to the skin influence the tactile stimuli experienced by the mechanoreceptors. A numerical, hyperelastic, four-layered skin model was developed to simulate sliding of the finger against a rigid surface. The strain, deviatoric stress and strain energy density were recorded at the sites of the Merkel and Meissner receptors, whilst parameters of the model were systematically varied to simulate age-related geometric and material skin changes. The simulations comprise changes in skin layer stiffness, flattening of the dermal-epidermal junction and thinning of the dermis. It was found that the stiffness of the skin layers has a substantial effect on the stimulus magnitudes recorded at mechanoreceptors. Additionally, reducing the thickness of the dermis has a substantial effect on the Merkel disc whilst the Meissner corpuscle is particularly affected by flattening of the dermal epidermal junction. In order to represent aged skin, a model comprising a combination of ageing manifestations revealed a decrease in stimulus magnitudes at both mechanoreceptor sites. The result from the combined model differed from the sum of effects of the individually tested ageing manifestations, indicating that the individual effects of ageing cannot be linearly superimposed. Each manifestation of ageing results in a decreased stimulation intensity at the Meissner Corpuscle site, suggesting that ageing reduces the proportion of stimuli meeting the receptor amplitude detection threshold. This model therefore offers an additional biomechanical explanation for tactile perceptive degradation amongst the elderly. Applications of the developed model are in the evaluation of cosmetics products aimed at mitigating the effects of ageing, e.g. through skin hydration and administration of antioxidants, as well as in the design of products with improved tactile sensation, e.g. through the optimisation of materials and surface textures. [ABSTRACT FROM AUTHOR]

• Deformable substrate thickness affects adjacent peeling fronts elastic interactions. • Load controlled critical detached length exists able to prevent abrupt peeling. • Non-monotonic effect of substrate thickness on critical detached length is reported. • Peeling load can be minimized by tuning substrate thickness and peeling spacing. In this paper, we investigate the periodic peeling behavior of opposing symmetric peeling fronts involving an elastic tape peeled off from a deformable substrate of finite thickness, backed onto a rigid foundation. We treat the problem by means of an energetic formulation, and we found that, depending on the values of the initial detached length l , substrate thickness h , and peeling periodicity λ , the translational invariance of the peeling process is lost and restored, as the elastic interaction between the peeling fronts is limited by the substrate thickness. Indeed, given h and λ , a critical value of the detached length can be found, which is able to prevent unstable peeling of the tape under a fixed applied load, thus resulting in enhanced adhesion strength, with respect to the classical Kendall's solution for peeling from a rigid substrate. On the other hand, given the geometrical system configuration (i.e. the detached length l) the load necessary to trigger the peeling can be minimized by conveniently tuning the ratio h / λ. This feature might be of interest for the development of innovative designs for future biomedical devices, such as Transdermal Drug Delivery Systems or wound dressing, requiring low peel adhesion for safe successive removals. [ABSTRACT FROM AUTHOR]

The phase behavior of a confined liquid at high pressure and shear rate, such as is found in elastohydrodynamic lubrication, can influence the traction characteristics in machine operation. Generic aspects of this behavior are investigated here using Non-equilibrium Molecular Dynamics (NEMD) simulations of confined Lennard-Jones (LJ) films under load with a recently proposed wall-driven shearing method without wall atom tethering [C. Gattinoni et al., Phys. Rev. E 90, 043302 (2014)]. The focus is on thick films in which the nonequilibrium phases formed in the confined region impact on the traction properties. The nonequilibrium phase and tribological diagrams are mapped out in detail as a function of load, wall sliding speed, and atomic scale surface roughness, which is shown can have a significant effect. The transition between these phases is typically not sharp as the external conditions are varied. The magnitude of the friction coefficient depends strongly on the nonequilibrium phase adopted by the confined region of molecules, and in general does not follow the classical friction relations between macroscopic bodies, e.g., the frictional force can decrease with increasing load in the Plug-Slip (PS) region of the phase diagram owing to structural changes induced in the confined film. The friction coefficient can be extremely low (~0.01) in the PS region as a result of incommensurate alignment between a (100) face-centered cubic wall plane and reconstructed (111) layers of the confined region near the wall. It is possible to exploit hysteresis to retain low friction PS states well into the central localization high wall speed region of the phase diagram. Stick-slip behavior due to periodic in-plane melting of layers in the confined region and subsequent annealing is observed at low wall speeds and moderate external loads. At intermediate wall speeds and pressure values (at least) the friction coefficient decreases with increasing well depth of the LJ potential between the wall atoms, but increases when the attractive part of the potential between wall atoms and confined molecules is made larger. [ABSTRACT FROM AUTHOR]