1,216 research outputs found

    Experimental and Numerical Behavior of Basalt Fiber Reinforced Short Concrete Columns Under Axial Loading

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    This paper presents experimental and numerical investigations to reveal effecting of incorporating basalt fibers into a concrete matrix on the structural behavior and loading capacity of axially loaded short columns. Six volume fractions of chopped basalt fibers are added to the same concrete mixture to prepare six identically reinforced columns. The results illustrate that the bonding forces between microfilaments and matrix increase to provide good internal confinement for concrete ingredients, which enhances compressive strength and column loading capacity. The 0.3 % basalt fiber awarded the best compressive strength, while 0.15 % and 0.3 % awarded the best load capacity to the column. The Addition of basalt fibers delays cracking to increase the cracking load by about 50 % more than no fiber column, which indicates that it needs more energy to overcome the bonding strength between filaments and matrix. At the ultimate state, the loading capacity increases by 15 % and 17 % for 0.15 % and 0.3 % of basalt fibers and by 10 % and 12 % for 0.45% and 0.6% of basalt fiber. The 0.75 % decreased compressive strength by about 6 % but raised the column's ultimate load by 18 %. Therefore, basalt fiber benefits the cracking load more than the maximum load. The finite element showed approaching the peak load in numerical and experimental results. The longitudinal rebars and ties do not yield at the ultimate state. Increasing the reinforcement ratio raises loading capacity while lowering the yield stress of bars minimizes the maximum load

    Aplikasi Fuzzy Linear Programming untuk Produksi Bola Lampu di PT XYZ

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    PT XYZ merupakan Perusahaan yang memproduksi bola lampu. Permintaan pasar yang tinggi menyebabkan Perusahaan tidak dapat memenuhi permintaan tersebut dikarenakan perencanaan produksi yang tidak optimal. Dari data, diketahui bahwa Perusahaan tidak dapat memenuhi permintaan pasar pada produk bola lampu merek Stanlee Star G-20 sebesar 8% dan S-25 sebesar 18,32% sedangkan bola lampu merek Dai-Ichi G40 diproduksi melebihi permintaan pasar sebesar 9,1%. Hal ini menyebabkan Perusahaan kehilangan opportunity profit. Perencanaan produksi bola lampu diteliti dengan tujuan agar Perusahaan dapat memenuhi permintaan pasar sesuai dengan keterbatasan sumber daya yang tersedia. Metode perencanaan produksi yang digunakan adalah metode fuzzy linear programming dengan metode simpleks. Dengan menggunakan Fuzzy Linear Programming dapat diperoleh nilai optimum jumlah produk bola lampu yang diproduksi sesuai permintaan pasar dan sesuai dengan keterbatasan sumber daya produksi. Sumber daya yang diteliti adalah kapasitas produksi, waktu kerja, dan bahan baku. Nilai interval logika fuzzy yang digunakan adalah t = 0 dan t = 1. Penyelesaian metode simpleks dilakukan dengan menggunakan software LINGO 13. Hasil penilitian menunjukkan bahwa permintaan pasar terpenuhi untuk ketiga merek bola lampu. Kapasitas produksi mencukupi sehingga tidak diperlukan penambahan jumlah mesin, sedangkan waktu kerja dan bahan baku tidak mencukupi. Perusahaan dapat menentukan jumlah bahan baku dan waktu kerja yang diperlukan dengan menggunakan nilai λ yaitu sebesar 0,536. Nilai λ digunakan untuk menentukan skala terbesar nilai interval t untuk setiap kendala bahan baku dan waktu kerja yaitu 0,464. Aplikasi fuzzy linear programming meningkatkan keuntungan sebesar 7,39% dari konsep linear programming biasa

    Aktivitas Antioksidan Ekstrak Etanol Buah, Daun, Batang Dan Rimpang Pada Tanaman Wualae (Etlingera Elatior (Jack) R.M Smith): Antioxidant Activity of Ethanol Extract of Fruits, Leaves, Stems and Rhizome of Wualae (Etlingera Elatior (Jack) R.M Smith)

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    Wualae (Etlingera elatior (Jack) R.M Smith) is one of the plants in the Zingiberaceae family, widely used in medicine ranging from rhizomes, fruits, and flowers. Empirically Wualae are usually used by people for treating skin diseases, flavoring food, a natural soap, and in Southeast Sulawesi, it is used to treat typhoid fever. This study aims to examine the antioxidant activity of Wualae (Etlingera elatior) plant. The plant extracts were extracted by maceration method, antioxidant activity test was performed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method. The results showed that ethanol extracts of fruits, leaves, stems and rhizomes of Wualae (Etlingera elatior) has the potential antioxidant activity with the IC50 values of 72.518 mg/L, 99.890 mg/L, 52.345 mg/L and 58.638 mg/L, respectively. and Vitamin C has IC50 value of 3,787 mg/L

    Petrogenesis of Rinjani Post-1257-Caldera-Forming-Eruption Lava Flows

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    DOI:10.17014/ijog.3.2.107-126After the catastrophic 1257 caldera-forming eruption, a new chapter of Old Rinjani volcanic activity beganwith the appearance of Rombongan and Barujari Volcanoes within the caldera. However, no published petrogeneticstudy focuses mainly on these products. The Rombongan eruption in 1944 and Barujari eruptions in pre-1944, 1966,1994, 2004, and 2009 produced basaltic andesite pyroclastic materials and lava flows. A total of thirty-one sampleswere analyzed, including six samples for each period of eruption except from 2004 (only one sample). The sampleswere used for petrography, whole-rock geochemistry, and trace and rare earth element analyses. The Rombonganand Barujari lavas are composed of calc-alkaline and high K calc-alkaline porphyritic basaltic andesite. The magmashows narrow variation of SiO2 content that implies small changes during its generation. The magma that formedRombongan and Barujari lavas is island-arc alkaline basalt. Generally, data show that the rocks are enriched in LargeIon Lithophile Elements (LILE: K, Rb, Ba, Sr, and Ba) and depleted in High Field Strength Elements (HFSE: Y, Ti,and Nb) which are typically a suite from a subduction zone. The pattern shows a medium enrichment in Light REEand relatively depleted in Heavy REE. The processes are dominantly controlled by fractional crystallization andmagma mixing. All of the Barujari and Rombongan lavas would have been produced by the same source of magmawith little variation in composition caused by host rock filter process. New flux of magma would likely have occurredfrom pre-1944 until 2009 period that indicates slightly decrease and increase of SiO2 content. The Rombongan andBarujari lava generations show an arc magma differentiation trend

    Lowering virus attack with improved yield and fiber quality in different cotton genotypes by early sown cotton (Gossypium hirsutum L.)

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    A three year study with the objective of exploring the possible role of different sowing dates and cotton genotypes on seed cotton yield, fiber quality and virus attack was conducted at the Cotton Research Station (CRS), Multan, Pakistan during three consecutive years (2006, 2007 and 2008). Two cotton genotypes namely: MNH-6070 and CIM-496 were sown on five different sowing dates (15th April, 1st May, 15th May, 1st June and 15th June) during the three consecutive years (2006, 2007 and 2008). The analyzed data indicated that early sown cotton (15th April) resulted in low virus attack (21.06%) and enhanced seed cotton yield (1575%), together with yield components (number of bolls per plant and boll weight), and improved fiber quality (staple length and micronaire) during all the three years as compared with late sown crop (15th June). Likewise, MNH-6070 also resulted in low virus attack (45.79%) and higher seed cotton yield (117.19%), as well as yield components. Regarding fiber quality, MNH-6070 resulted in higher micronarie, while CIM-496 resulted in higher staple length. Early sowing and cotton genotype MNH-6070 also resulted in maximum ginning out turn (GOT). Nonetheless, seed cotton yield and fiber quality were both negatively affected due to late sowing (1st and 15th of June) in both cotton genotypes. In crux, early sowing enhanced seed cotton yield due to increased number of bolls per plant, boll weight and low virus attack. Similarly, cotton genotype MNH-6070 also resulted to higher seed cotton yield, GOT and more resistance against virus attack due to its better genetic makeup. In summary, cotton genotype MNH-6070 should be sown on 15th April in order to obtain maximum seed cotton yield under agro-climatic conditions of Multan, Pakistan.Key words: Sowing time, seed cotton yield, staple length, micronaire

    The FGF-21 genetic variants rs838133 and rs838145 are associated with high salt intake in the Emirati population

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    Food predilection is linked to variants in the hepatokine “Fibroblast Growth Factor-21” gene (FGF21); with rs838133 linked to the sweet tooth in Caucasians. The effect of FGF21 variants on food intake is still unclear in other populations. A cohort of 196 healthy Emirati subjects was investigated [age: 30.34 ± 9.75yrs (44.4% males)]. The FGF21 rs838133 and rs838145 were genotyped. The daily intake was calculated based on a 61-item food frequency questionnaire. Multivariate analysis was performed using in house R script that implements two-way unsupervised hierarchical clustering to detect the association of the studied single-nucleotide polymorphisms (SNPs) and related SNPs in linkage disequilibrium, using data from the 1000 genome project. Both SNPs were in Hardy-Weinberg Equilaribium (HWE). BMI positively correlated with age (p = 0.002), but not with caloric intake. Salt intake was significantly higher in subjects homozygous (A: rs838133) and (G:rs838145),(p = 0.03 and 0.01, respectively). An interaction was observed between both SNPs; significantly associated with high salt intake. Using publicly available data, both SNPs fall within a region transmitted in Iberians which has a profile closely similar to Caucasians, but far from Chinese population. In conclusion, the minor alleles of FGF21 rs838145 and rs838133 are associated with high salt intake in Emiratis and may suggest neuro-metabolic link to dietary preference across different populations

    Whole-organism phenotypic screening methods used in early-phase anthelmintic drug discovery

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    Diseases caused by parasitic helminths (worms) represent a major global health burden in both humans and animals. As vaccines against helminths have yet to achieve a prominent role in worm control, anthelmintics are the primary tool to limit production losses and disease due to helminth infections in both human and veterinary medicine. However, the excessive and often uncontrolled use of these drugs has led to widespread anthelmintic resistance in these worms - particularly of animals - to almost all commercially available anthelmintics, severely compromising control. Thus, there is a major demand for the discovery and development of new classes of anthelmintics. A key component of the discovery process is screening libraries of compounds for anthelmintic activity. Given the need for, and major interest by the pharmaceutical industry in, novel anthelmintics, we considered it both timely and appropriate to re-examine screening methods used for anthelmintic discovery. Thus, we reviewed current literature (1977-2021) on whole-worm phenotypic screening assays developed and used in academic laboratories, with a particular focus on those employed to discover nematocides. This review reveals that at least 50 distinct phenotypic assays with low-, medium- or high-throughput capacity were developed over this period, with more recently developed methods being quantitative, semi-automated and higher throughput. The main features assessed or measured in these assays include worm motility, growth/development, morphological changes, viability/lethality, pharyngeal pumping, egg hatching, larval migration, CO2- or ATP-production and/or enzyme activity. Recent progress in assay development has led to the routine application of practical, cost-effective, medium- to high-throughput whole-worm screening assays in academic or public-private partnership (PPP) contexts, and major potential for novel high-content, high-throughput platforms in the near future. Complementing this progress are major advances in the molecular data sciences, computational biology and informatics, which are likely to further enable and accelerate anthelmintic drug discovery and development

    Dynamic Clustering and Management of Mobile Wireless Sensor Networks

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    In Wireless Sensor Networks (WSNs), routing data towards the sink leads to unbalanced energy consumption among intermediate nodes resulting in high data loss rate. The use of multiple Mobile Data Collectors (MDCs) has been proposed in the literature to mitigate such problems. MDCs help to achieve uniform energy-consumption across the network, fill coverage gaps, and reduce end-to-end communication delays, amongst others. However, mechanisms to support MDCs such as location advertisement and route maintenance introduce significant overhead in terms of energy consumption and packet delays. In this paper, we propose a self-organizing and adaptive Dynamic Clustering (DCMDC) solution to maintain MDC-relay networks. This solution is based on dividing the network into well-delimited clusters called Service Zones (SZs). Localizing mobility management traffic to a SZ reduces signaling overhead, route setup delay and bandwidth utilization. Network clustering also helps to achieve scalability and load balancing. Smaller network clusters make buffer overflows and energy depletion less of a problem. These performance gains are expected to support achieving higher information completeness and availability as well as maximizing the network lifetime. Moreover, maintaining continuous connectivity between the MDC and sensor nodes increases information availability and validity. Performance experiments show that DCMDC outperforms its rival in the literature. Besides the improved quality of information, the proposed approach improves the packet delivery ratio by up to 10%, end-to-end delay by up to 15%, energy consumption by up to 53%, energy balancing by up to 51%, and prolongs the network lifetime by up to 53%

    Enhancing hexavalent chromium removal from textile effluent with low-cost adsorbent: simulation and a techno-economic study

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    This paper simulated hexavalent chromium (Cr(VI)) adsorption using cocoa pod husk biosorbent in a fixed bed column using Aspen Adsorption. This study was designed to show the effectiveness of computational methods in designing, optimising and evaluating the scaled-up adsorption process using low-cost adsorbents. To the best of our knowledge, the economic analysis of Cr(VI) removal using biosorbent adsorption columns with the assistance of Aspen Adsorption and response-surface methodology (RSM) has not been performed previously. Design Expert and RSM were used to optimise and describe the effect of flow rate and initial concentration on breakthrough and saturation times. The breakthrough time was improved by a higher bed height (2.0 m), a wider diameter (2.0 m), and lowering the flow rate (0.010 L/s). The initial concentration had no effect (1.00 mol/L). The predicted breakthrough and saturation time were 29,360 s and 313,351 s, respectively. Two scenarios were economically compared over 20 years. Scenario 1 (1-day breakthrough time) costs 746,585andScenario2(4weekbreakthroughtime)costs746,585 and Scenario 2 (4-week breakthrough time) costs 1,538,319. This is because Scenario 2 used a taller, wider column which required a greater amount of adsorbent, and 387,873 m3 of water were processed, respectively. Processed water was dependent on the flow rate and breakthrough time. It was concluded that cocoa pod husk could be an efficient adsorbent and the adsorption process can be successfully simulated and optimised. The use of alternative low-cost adsorbents should be encouraged. The economic study showed that simulation and RSM data could successfully be used for economic analysis

    Quantum Tricritical Points in NbFe2_2

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    Quantum critical points (QCPs) emerge when a 2nd order phase transition is suppressed to zero temperature. In metals the quantum fluctuations at such a QCP can give rise to new phases including unconventional superconductivity. Whereas antiferromagnetic QCPs have been studied in considerable detail ferromagnetic (FM) QCPs are much harder to access. In almost all metals FM QCPs are avoided through either a change to 1st order transitions or through an intervening spin-density-wave (SDW) phase. Here, we study the prototype of the second case, NbFe2_2. We demonstrate that the phase diagram can be modelled using a two-order-parameter theory in which the putative FM QCP is buried within a SDW phase. We establish the presence of quantum tricritical points (QTCPs) at which both the uniform and finite qq susceptibility diverge. The universal nature of our model suggests that such QTCPs arise naturally from the interplay between SDW and FM order and exist generally near a buried FM QCP of this type. Our results promote NbFe2_2 as the first example of a QTCP, which has been proposed as a key concept in a range of narrow-band metals, including the prominent heavy-fermion compound YbRh2_2Si2_2.Comment: 21 pages including S
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