Electrophoretic Deposition (EPD) of Multi-Walled Carbon Nanotubes (Mwcnts) Onto Carbon Fiber (CF) Fabric

The Fiber Reinforced Polymer Composite (FRPC) has been widely employed in structural applications. However, adding nanoparticles such as multi-walled carbon nanotubes (MWCNTs) can be used to improve the composites' mechanical properties substantially. The purpose of this study is to investigate the stability of MWCNTs in distilled water (DW) and dimethylformamide (DMF). Electrophoretic deposition (EPD) was chosen as the method for depositing MWCNTs onto carbon fiber (CF) fabric because of the advantages of simple equipment and inexpensive cost. Thus, the effect of voltage and deposition time were examined to attain the ideal condition for the EPD of MWCNTs onto CF fabric. The stability of dispersed MWCNTs in various dispersing mediums was explored as the importance of the MWCNTs to remain stable in the medium is essential to achieve homogeneous deposition. The UV-Vis and colloidal stability test revealed that MWCNTs dispersed in DMF have greater stability than DW. Scanning Electrode Microscopy (SEM) images exhibited that 10 minutes and a 20 V voltage were the optimal conditions for the deposition of MWCNTs onto CF fabric.   &nbsp

Electrophoretic Deposition (EPD) of Multi-Walled Carbon Nanotubes (Mwcnts) Onto Carbon Fiber (CF) Fabric

The Fiber Reinforced Polymer Composite (FRPC) has been widely employed in structural applications. However, adding nanoparticles such as multi-walled carbon nanotubes (MWCNTs) can be used to improve the composites' mechanical properties substantially. The purpose of this study is to investigate the stability of MWCNTs in distilled water (DW) and dimethylformamide (DMF). Electrophoretic deposition (EPD) was chosen as the method for depositing MWCNTs onto carbon fiber (CF) fabric because of the advantages of simple equipment and inexpensive cost. Thus, the effect of voltage and deposition time were examined to attain the ideal condition for the EPD of MWCNTs onto CF fabric. The stability of dispersed MWCNTs in various dispersing mediums was explored as the importance of the MWCNTs to remain stable in the medium is essential to achieve homogeneous deposition. The UV-Vis and colloidal stability test revealed that MWCNTs dispersed in DMF have greater stability than DW. Scanning Electrode Microscopy (SEM) images exhibited that 10 minutes and a 20 V voltage were the optimal conditions for the deposition of MWCNTs onto CF fabric.   &nbsp

Analisis Perbandingan Material Slab Beton pada Perkerasan Apron dengan Menggunakan Program Bantu Elemen Hingga

Kekuatan slab beton sangat dipengaruhi oleh jenis material yang dipakai. Jenis material yang dimaksud adalah material beton dengan menggunakan PC (Portland Cement) dan penggunaan geopolimer dalam komposisi campuran slab beton. Beton geopolimer merupakan beton yang ramah lingkungan. Permasalahan lain yang timbul adalah letak roda pesawat tidak selalu berada pada titik yang sama disuatu permukaan slab beton apron. Pada tugas akhir ini dimaksudkan untuk menganalisis suatu slab beton yang dibebani roda pesawat dengan campuran variasi material beton dan variasi letak roda pesawat pada slab beton dengan program bantu metode elemen hingga. Dengan data pergerakan pesawat, spesifikasi apron bandara Juanda kondisi eksisting. Dilakukan perhitungan tebal slab beton menggunakan software FAARFIELD dan diperoleh tebal slab beton sebesar 442,5 mm. Dari analisis program bantu elemen hingga dapat diperoleh tegangan pada slab beton yang ditimbulkan oleh pembebanan roda pesawat. Hasil validasi dari analisis tegangan menggunakan program bantu elemen hingga dengan analisis Westergaard yaitu memiliki nilai tegangan yang hampir sama pada ketebalan slab beton 450mm. Nilai tegangan tiap-tiap material beton menunjukan nilai tebal slab beton yang diijinkan untuk tipe pesawat tertentu. Dari analisis menggunakan program bantu elemen hingga tebal slab beton yang diijinkan untuk material slab beton PC yaitu sebesar 425mm. Sedangkan untuk material beton geopolimer yaitu sebesar 415 mm

Optimization of water extract of Cinnamomum burmannii bark to ascertain its in vitro antidiabetic and antioxidant activities

The antidiabetic and antioxidant activity of water extract of Cinnamomum burmannii bark is well documented. This research aimed to optimize cinnamon water extraction process and verify active components instigating its in vitro antidiabetic activity. The study employed Design Expert 7.0 program to derive factorial design and optimization conditions. The extraction step comprised of three factors (temperature, concentration and time of extraction) and two levels (low and high), with four responses observed (yield, total phenolic content, IC50DPPH antioxidant activity, and IC50 α-glucosidase inhibition). The polynomial equations revealed influence and interaction among the selected factors to the responses and obtained overlay optimization of factors to responses. The results indicated that optimal temperature, concentration, and extraction time were 98 °C, 30% and 20 min, respectively. Corresponding DPPH, α-glucosidase, TPC, and yield values were 3.45 μg/ml, 0.50 μg/ml, 259.08 μg GAE/mg of sample, 6.28%, respectively. LCMS analysis of the optimum extract confirmed typical characteristic of C. burmanii contents (coumarins, polymers of proanthocyanidins A-type and protonated heterodimer of flavan-3-ol group). The optimized water extract of C.burmannii has the potency to assist in complementary therapy to modulate diabetes mellitus

Peningkatan Hasil Belajar Melalui Pembelajaran Kooperatif Tipe Jigsaw Dalam Materi Bilangan Bulat Kelas IV Semester II SD Negeri Sumberejo I Kecamatan Mranggen Kabupaten Demak Tahun Ajaran 2011/2012

Di SDN Sumberejo I terdapat di daerah pedesaan, oleh karena itu mempengaruhi pola pikir dan perilaku siswanya. Dalam pembelajaran matematika oleh guru dan siswanya tidak aktif. Dikarenakan guru tidak menggunakan model pembelajaran, sehingga pembelajaran menjadi membosankan. Tujuan penelitian yaitu siswa dapat mencapai Kriteria Ketuntasan Minimal (KKM) dengan model pembelajaran Jigsaw, hasil belajar siswa dapat meningkat melalui model pembelajaran Jigsaw, dan siswa dapat terlibat aktif dalam pembelajaran matematika melalui model pembelajaran Jigsaw. Metodologi Penelitian meliputi subyek penelitian yaitu siswa kelas IV SDN Sumberejo I Kecamatan Mranggen Kabupaten Demak Tahun Ajaran 2011/ 2012, tempat penelitian di kelas IV SDN Sumberejo I Kecamatan Mranggen Kabupaten Demak, variabel penelitian ada dua yaitu variabel bebas adalah pembelajaran matematika dengan Kooperatif tipe Jigsaw dan variabel terikatnya adalah hasil belajar siswa, teknik pengumpulan data meliputi observasi, dokumentasi, dan tes formatif siswa, metode analisis data meliputi analisis instrumen tes dengan uji validitas, reliabilitas, dan tingkat kesukaran tes, sedangkan teknik analisis data dengan cara menghitung ketuntasan individu dan kelompok, hasil belajar siswa, dan keaktifan siswa dalam pembelajaran matematika. Dari analisis hasil belajar yang dicapai oleh siswa, pada pembelajaran siklus I diketahui nilai terendah 10 dan nilai tertinggi 100, dengan nilai rata-rata kelas 56,67. Siswa yang tuntas dengan nilai KKM 65 ada 11 siswa atau 36,7% dan siswa yang tidak tuntas ada 19 siswa atau 63,3%. Berdasarkan data pengamatan yang telah dilakukan pada siklus I perlu adanya perbaikan pembelajaran pada siklus II. Dari analisis hasil belajar yang dicapai oleh siswa, pada proses perbaikan pembelajaran pada siklus II diketahui nilai terendah 50 dan nilai tertinggi 100 dengan nilai rata-rata kelas 70. Siswa yang tuntas dengan nilai KKM 65 ada 19 siswa atau 63,3% dan siswa yang tidak tuntas ada 11 siswa atau 36,7%. Berdasarkan data pengamatan yang telah dilakukan pada siklus II perlu adanya perbaikan pembelajaran pada siklus III. Dari analisis hasil belajar yang dicapai oleh siswa diketahui nilai terendah adalah 60 dan nilai tertinggi adalah 100 dengan nilai rata-rata kelas adalah 78,33. Siswa yang tuntas dengan nilai KKM 65 ada 27 siswa atau 90% dan siswa yang tidak tuntas ada 3 siswa atau 10%. Berdasarkan data pengamatan yang telah dilakukan pada siklus III diketahui bahwa siswa siswa dapat mencapai KKM, hasil belajar siswa dapat meningkat, dan siswa dapat terlibat aktif dalam pembelajaran matematika melalui model pembelajaran Jigsaw

Human mucosal associated invariant T cells detect bacterially infected cells

Control of infection with Mycobacterium tuberculosis (Mtb) requires Th1-type immunity, of which CD8+ T cells play a unique role. High frequency Mtb-reactive CD8+ T cells are present in both Mtb-infected and uninfected humans. We show by limiting dilution analysis that nonclassically restricted CD8+ T cells are universally present, but predominate in Mtbuninfected individuals. Interestingly, these Mtb-reactive cells expressed the Va7.2 T-cell receptor (TCR), were restricted by the nonclassical MHC (HLA-Ib) molecule MR1, and were activated in a transporter associated with antigen processing and presentation (TAP) independent manner. These properties are all characteristics of mucosal associated invariant T cells (MAIT), an "innate" T-cell population of previously unknown function. These MAIT cells also detect cells infected with other bacteria. Direct ex vivo analysis demonstrates that Mtb-reactive MAIT cells are decreased in peripheral blood mononuclear cells (PBMCs) from individuals with active tuberculosis, are enriched in human lung, and respond to Mtb-infected MR1-expressing lung epithelial cells. Overall, these findings suggest a generalized role for MAIT cells in the detection of bacterially infected cells, and potentially in the control of bacterial infection. © 2010 Gold et al

The ability of analysts’ recommendations to predict optimistic and pessimistic forecasts

Previous researches show that buy (growth) companies conduct income increasing earnings management in order to meet forecasts and generate positive forecast Errors (FEs). This behavior however, is not inherent in sell (non-growth) companies. Using the aforementioned background, this research hypothesizes that since sell companies are pressured to avoid income increasing earnings management, they are capable, and in fact more inclined, to pursue income decreasing Forecast Management (FM) with the purpose of generating positive FEs. Using a sample of 6553 firm-years of companies that are listed in the NYSE between the years 2005–2010, the study determines that sell companies conduct income decreasing FM to generate positive FEs. However, the frequency of positive FEs of sell companies does not exceed that of buy companies. Using the efficiency perspective, the study suggests that even though buy and sell companies have immense motivation in avoiding negative FEs, they exploit different but efficient strategies, respectively, in order to meet forecasts. Furthermore, the findings illuminated the complexities behind informative and opportunistic forecasts that falls under the efficiency versus opportunistic theories in literature

Microstructural evolution of 96.5Sn–3Ag–0.5Cu lead free solder reinforced with nickel-coated graphene reinforcements under large temperature gradient

This is an Open Access Article. It is published by Springer under the Creative Commons Attribution 4.0 International Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/In this study, 96.5Sn–3Ag–0.5Cu (SAC305) lead-free composite solder containing graphene nanosheets (GNS) decorated with Ni nanoparticles (Ni-GNS) was prepared using a powder metallurgy method. A lab-made set-up and a corresponding Cu/solder/Cu sample design for assessing thermo-migration (TM) was established. The feasibility of this setup for TM stressing using an infrared thermal imaging method was verified; a temperature gradient in a solder joint was observed at 1240 K/cm. Microstructural evolution and diffusion of Cu in both plain and composite solder joints were then studied under TM stressing conditions. Compared to unreinforced SAC305 solder, the process of diffusion of Cu atoms in the composite solder joint was significantly reduced. The interfacial intermetallic compounds (IMCs) present in the composite solder joint also provide a more stable morphology after the TM test for 600 h. Furthermore, during the TM test, the Ni-GNS reinforcement affects the formation, migration and distribution of Ni–Cu–Sn and Cu–Sn IMCs by influencing the dissolution rate of Cu atoms

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Colloidal stability of water-based carbon nanotube suspensions in electrophoretic deposition process: Effect of applied voltage and deposition time

The addition of nanoparticles as reinforcement to conventional fiber reinforced plastics shows great promise to be used as advanced structural materials. The aim of this study is to produce a hierarchical carbon fiber (CF)-multi-walled carbon nanotubes (MWCNTs) using electrophoretic deposition (EPD) method. Realizing the benefits of the water-based EPD method, the effect of voltages and deposition times on the MWCNTs stability in distilled water (DW) were investigated. The UV–Vis and stability test observations demonstrated better dispersion and higher colloidal stability of MWCNTs in DW suspension within a short time. With the presence of an applied voltage, MWCNTs-DW suspension was well dispersed with minimal sedimentation. Flexural properties of laminate composites and Field Emission Scanning Electron Microscopy (FESEM) images revealed the best EPD condition for the deposition of the MWCNTs onto the CF was determined to be a deposition time of 5 min and applied voltage of 20 V. © 2018 Elsevier Lt