465 research outputs found

    EFEK PERKUATAN GLASS FIBER REINFORCE POLYMER-SHEET PADA BALOK BETON BERTULANG DENGAN TULANGAN KOROSI

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    Abstrak Artikel ini menyajikan tentang balok beton bertulang yang tulangannya telah korosi kemudian diberi perkuatan ekternal berupa serat glass tipe lembaran atau Glass Fiber reinforced Polymer-Sheet (GFRP-S). Pada studi ini variabel berdasarkan variasi tingkat korosi pada tulangan. Lima macam benda uji yang digunakan berbentuk balok dengan dimensi 15x20 cm panjang 160 cm. Tulangan utama yang digunakan besi f12 dan tulangan sengkang f8-100. Mutu beton digunakan 25 MPa. Balok beton bertulangan normal tanpa perkuatan sebagai balok kontrol (BN), balok beton bertulangan normal dengan perkuatan GFRP-S (BP), balok beton bertulangan korosi dengan perkuatan GFRP-S (BPK), variasi waktu pengkorosian tulangan selama 2 minggu (BPK2), 4 minggu (BPK4) dan 6 minggu (BPK6) dengan metode perendaman pada larutan asam sulfat 2,0%. Balok diperkuat GFRP-S pada daerah Tarik di bagian bawah balok. Pengujian lentur dengan twopoint load. Hasil penelitian menunjukkan bahwa balok beton bertulang yang diperkuat dengan GFRP-S mempunyai kapasitas lebih besar dibandingkan dengan balok normal sebesar 12,07%. Balok beton bertulang dengan tulangan tingkat korosi lebih besar (pengkorosian 6 minggu) cenderung menurunkan kapasitas balok namun kapasitasnya masih lebih besar dari balok normal sebesar 1,38%. Kata kunci: balok beton, tulangan korosi, asam sulfat, GFRP-S  Abstract This article presents about reinforced concrete beams whose reinforcement has been corroded and then externally reinforced in the form of sheet type glass fiber or Glass Fiber Reinfroced Polymer-Sheet (GFRP-S). In this study, the variables are based on variations in the level of corrosion on the reinforcement. Five kinds of test objects used in the form of blocks with dimensions of 15x20 cm and length of 160 cm. The main reinforcement used is f12 and f8-100 stirrup reinforcement. The quality of the concrete used is 25 MPa. Normal reinforced concrete beams without reinforcement as control beams (BN), normal reinforced concrete beams with GFRP-S reinforcement (BP), corrosion reinforced concrete beams with GFRP-S reinforcement (BPK), variations in reinforcement corrosion time for 2 weeks (BPK2), 4 weeks (BPK4)and 6 weeks (BPK6) by immersion method in 2.0% sulfuric acid solution. The beam is reinforced with GFRP-S in the Tensile region at the bottom of the beam. Flexural test with two point load. The results showed that reinforced concrete beams reinforced with GFRP-S had a larger capacity than normal beams by 12.70%. Reinforced concrete beams with reinforcement with a higher corrosion rate (6 weeks corrosion) tend to reduce the capacity of the beam but its capacity is still larger than normal beams by 1.38%. Keywords: concrete beam, corrosion reinforcement, sulfuric acid, GFRP-S

    Penggunaan Media Kreasi Puzzle Tubol dalam Mengembangkan Kemampuan Kognitif Anak Usia Dini

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    Media pembelajaran yang baik dapatmembantu penyerapan pembelajaran menjadi lebih optimal. Selaras dengan itu, pembelajaran yang baik dapat meningkatkan kemampuan kognitif anak. Kemampuan kognitif tersebut sangat penting dikuasai agar siswa mendapat pengetahuan dan nilai yang baik pada setiap pembelajaran. Penelitian ini bertujuan untuk menganalisis perkembangan kognitif anak melalui penggunaan media kreasi puzzle tubol di PAUD Mutiara Ummi Candi Sidoarjo. Penelitian deskriptif kualitatif ini menemukan bahwa dengan menggunakan media kreasi puzzle tubol, tingkat dalam kemampuan kognitif siswa kelas A menujukkan hasil akhir yaitu BSB (berkembang sangat Baik). Namun, perlu digarisbawahi, sebelum menggunakan media ini, guru perlu menyiapkan langkah-langkah tutorialnya. Karena, setelah menggunakan media tersebut, guru harus memberi kesempatan kepada siswa untuk mengaplikasikannya

    TITANIUM NANOPARTICLES CONJUGATED WITH STREPTOKINASE AS A MODIFIED THROMBOLYTIC AGENT

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    Objective: Blood clots are the main cause of death worldwide by stroke and myocardial infarction. Streptokinase a thrombolytic agent that is used in the treatment of circulatory disorders. Methods: Titanium Nanoparticles was supplied from Changsha Santech Co. Its characterized were studied using (FT-IR, XRD, AFM, FE-SEM). Streptokinase at concentration 0.1 mg/ml was conjugated with Titanium nanoparticles using PH equal to 5.2 with continuous stirring. Formation of Streptokinase loading Titanium nanoparticles confirmed using FT-IR, Ninhydrine’s test and Bradford protein assay. Physicochemical Properties were studied in vitro. Thrombolytic activity in vitro was determined using d–dimer indicator and weight of blood clot after treatment as indicators of thrombolytic activity. Results: Titanium nanoparticles show particle size at range 31 nm. The thrombolytic activity of streptokinase loading Titanium nanoparticles shows significant value in d-dimer and weight of blood clot compared with the control group and non-significant compared with an equivalent amount of streptokinase alone. Conclusion: Titanium nanoparticles conjugated with streptokinase show high thrombolytic activity against blood clots in vitro

    Complexity of Bradley-Manna-Sipma Lexicographic Ranking Functions

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    In this paper we turn the spotlight on a class of lexicographic ranking functions introduced by Bradley, Manna and Sipma in a seminal CAV 2005 paper, and establish for the first time the complexity of some problems involving the inference of such functions for linear-constraint loops (without precondition). We show that finding such a function, if one exists, can be done in polynomial time in a way which is sound and complete when the variables range over the rationals (or reals). We show that when variables range over the integers, the problem is harder -- deciding the existence of a ranking function is coNP-complete. Next, we study the problem of minimizing the number of components in the ranking function (a.k.a. the dimension). This number is interesting in contexts like computing iteration bounds and loop parallelization. Surprisingly, and unlike the situation for some other classes of lexicographic ranking functions, we find that even deciding whether a two-component ranking function exists is harder than the unrestricted problem: NP-complete over the rationals and Σ2P\Sigma^P_2-complete over the integers.Comment: Technical report for a corresponding CAV'15 pape

    Transformasi Pesantren (Studi terhadap Dialektika Kurikulum dan Kelembagaan Pondok Pesantren Rifaiyah Pati)

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    Penelitian ini bermaksud menganalisis perubahan kurikulum pesantren yang kini menjadi diskursus disebabkan dinamika kebijakan pengembangan kurikulum pendidikan nasional. Pada saat yang sama, dinamika pesantren dalam mengembangkan kurikulum, dengan mendirikan lembaga pendidikan formal yang menyerap substansi kurikulum yang diperlukan oleh masyarakat. Penulis menjadikan pondok pesantren Rifaiyah Pati sebagai objek penelitian mengingat pesantren ini survive dengan pengembangan kurikulum yang dialektis. Dengan menggunakan pendekatan kualitatif, data yang dikumpulkan dianalisis dengan narasi induktif, kemudian disajikan secara kronologis-analitis. Temuan penelitian ini adalah bahwa perkembangan pesantren Rifaiyah mempunyai beberapa kasus yang unik dan dinamis, mulai pergeseran orientasi pengembangan kurikulum, tradisi intelektual, hingga pada pertentangan yang disebabkan oleh ketidaksepemahaman mengenai arah ideologis pesantren. Kasus-kasus spesifik ini tentu saja berpengaruh terhadap kebijakan kelembagaan yang dijalankan oleh pesantren Rifaiyah dalam mewujudkan visi, misi dan tujuanya ke depan. Dari hal ini, penulis menarik benang merah bahwa perubahan pondok pesantren kerap dimulai dari kurikulum, kemudian merambah ke aspek yang lain seperti kelembagaan.Penelitian ini bermaksud menganalisis perubahan kurikulum pesantren yang kini menjadi diskursus disebabkan dinamika kebijakan pengembangan kurikulum pendidikan nasional. Pada saat yang sama, dinamika pesantren dalam mengembangkan kurikulum, dengan mendirikan lembaga pendidikan formal yang menyerap substansi kurikulum yang diperlukan oleh masyarakat. Penulis menjadikan pondok pesantren Rifaiyah Pati sebagai objek penelitian mengingat pesantren ini survive dengan pengembangan kurikulum yang dialektis. Dengan menggunakan pendekatan kualitatif, data yang dikumpulkan dianalisis dengan narasi induktif, kemudian disajikan secara kronologis-analitis. Temuan penelitian ini adalah bahwa perkembangan pesantren Rifaiyah mempunyai beberapa kasus yang unik dan dinamis, mulai pergeseran orientasi pengembangan kurikulum, tradisi intelektual, hingga pada pertentangan yang disebabkan oleh ketidaksepemahaman mengenai arah ideologis pesantren. Kasus-kasus spesifik ini tentu saja berpengaruh terhadap kebijakan kelembagaan yang dijalankan oleh pesantren Rifaiyah dalam mewujudkan visi, misi dan tujuanya ke depan. Dari hal ini, penulis menarik benang merah bahwa perubahan pondok pesantren kerap dimulai dari kurikulum, kemudian merambah ke aspek yang lain seperti kelembagaan

    Tidal dynamics and mangrove carbon sequestration during the Oligo–Miocene in the South China Sea

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    Modern mangroves are among the most carbon-rich biomes on Earth, but their long-term (≥106 yr) impact on the global carbon cycle is unknown. The extent, productivity and preservation of mangroves are controlled by the interplay of tectonics, global sea level and sedimentation, including tide, wave and fluvial processes. The impact of these processes on mangrove-bearing successions in the Oligo–Miocene of the South China Sea (SCS) is evaluated herein. Palaeogeographic reconstructions, palaeotidal modelling, and facies analysis suggest that elevated tidal range and bed shear stress optimised mangrove development along tide-influenced tropical coastlines. Preservation of mangrove organic carbon (OC) was promoted by high tectonic subsidence and fluvial sediment supply. Lithospheric storage of OC in peripheral SCS basins potentially exceeded 4000 Gt (equivalent to 2000 ppm of atmospheric CO2). These results highlight the crucial impact of tectonic and oceanographic processes on mangrove OC sequestration within the global carbon cycle on geological timescales

    Parental recommendations and exercise attitudes in congenital hearts.

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    BACKGROUND: Children and young people with CHD benefit from regular physical activity. Parents are reported as facilitators and barriers to their children's physical activity. The aim of this study was to explore parental factors, child factors, and their clinical experience on physical activity participation in young people with CHD. METHODS: An online questionnaire was co-developed with parents (n = 3) who have children with CHD. The survey was then distributed in the United Kingdom by social media and CHD networks, between October 2021 and February 2022. Data were analysed using mixed methods. RESULTS: Eighty-three parents/guardians responded (94% mothers). Young people with CHD were 7.3 ± 5.0 years old (range 0-20 years; 53% female) and 84% performed activity. Parental participation in activity (X2(1) = 6.9, P < 0.05) and perceiving activity as important for their child were positively associated with activity (Fisher's Exact, P < 0.05). Some parents (∼15%) were unsure of the safety of activity, and most (∼70%) were unsure where to access further information about activity. Fifty-two parents (72%) had never received activity advice in clinic, and of the 20 who received advice, 10 said it was inconsistent. Qualitative analysis produced the theme "Knowledge is power and comfort." Parents described not knowing what activity was appropriate or the impact of it on their child. CONCLUSION: Parental participation and attitudes towards activity potentially influence their child's activity. A large proportion of young people performed activity despite a lack and inconsistency of activity advice offered by CHD clinics. Young people with CHD would benefit from activity advice with their families in clinics

    Massive retroperitoneal tubercular abscess mimicking a leaking abdominal aortic aneurysm: a case report

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    In spite of being a common diagnosis in the patients of Asian origin, atypical presentations of tuberculosis may pose diagnostic challenges. We report a huge prevertebral abscess in a 30-year-old female, mimicking a leaking aortic aneurysm. The patient was managed successfully by emergency decompression and stabilization. The issues related to poor patient compliance to chemotherapy and management of atypical presentations of spinal tuberculosis are discussed here

    Gravitational collapse with tachyon field and barotropic fluid

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    A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of inverse square form i.e., V(\phi) \sim \phi^{-2}. Our purpose, by making use of the specific kinematical features of the tachyon, which are rather different from a standard scalar field, is to establish the several types of asymptotic behavior that our matter content induces. Employing a dynamical system analysis, complemented by a thorough numerical study, we find classical solutions corresponding to a naked singularity or a black hole formation. In particular, there is a subset where the fluid and tachyon participate in an interesting tracking behaviour, depending sensitively on the initial conditions for the energy densities of the tachyon field and barotropic fluid. Two other classes of solutions are present, corresponding respectively, to either a tachyon or a barotropic fluid regime. Which of these emerges as dominant, will depend on the choice of the barotropic parameter, \gamma. Furthermore, these collapsing scenarios both have as final state the formation of a black hole.Comment: 18 pages, 7 figures. v3: minor changes. Final version to appear in GR

    Tumor innate immunity primed by specific interferon-stimulated endogenous retroviruses.

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    Mesenchymal tumor subpopulations secrete pro-tumorigenic cytokines and promote treatment resistance1-4. This phenomenon has been implicated in chemorefractory small cell lung cancer and resistance to targeted therapies5-8, but remains incompletely defined. Here, we identify a subclass of endogenous retroviruses (ERVs) that engages innate immune signaling in these cells. Stimulated 3 prime antisense retroviral coding sequences (SPARCS) are oriented inversely in 3' untranslated regions of specific genes enriched for regulation by STAT1 and EZH2. Derepression of these loci results in double-stranded RNA generation following IFN-γ exposure due to bi-directional transcription from the STAT1-activated gene promoter and the 5' long terminal repeat of the antisense ERV. Engagement of MAVS and STING activates downstream TBK1, IRF3, and STAT1 signaling, sustaining a positive feedback loop. SPARCS induction in human tumors is tightly associated with major histocompatibility complex class 1 expression, mesenchymal markers, and downregulation of chromatin modifying enzymes, including EZH2. Analysis of cell lines with high inducible SPARCS expression reveals strong association with an AXL/MET-positive mesenchymal cell state. While SPARCS-high tumors are immune infiltrated, they also exhibit multiple features of an immune-suppressed microenviroment. Together, these data unveil a subclass of ERVs whose derepression triggers pathologic innate immune signaling in cancer, with important implications for cancer immunotherapy
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