664 research outputs found

    Cellulose Ether-Based Liquid Crystal Materials: Review Article

    Get PDF
    The development of liquid crystal materials via nanotechnology has become an interesting subject of research in optical material chemistry. One of the significant nanomaterials is cellulose-based nanoparticles. In this review article, we highlighted the classification of liquid crystal materials (LCs), and types of cellulose-NPs and their characterization as LCs materials. Finally, we present our promising data on the synergistic effect of cellulose-NPs on liquid crystal behavior of ethyl cellulose- and hydroxypropyl cellulose- nanocomposites

    Nutrition Anemia and Physical Endurance Among Civil Construction Workers

    Full text link
    Penyelidikan ini adalah untuk membuktikan suatu hypothesa bahwa ada pengaruh dari keadaan gizi dan kesehatan terhadap kemampuan bekerja para pekerja. Sejumlah 571 pekerja laki-laki telah dipilih dari tiga daerah tempat bekerja yaitu : Rentang, Seladarma (pembuatan canalj Halim Perdanakusuma (pembuatan lapangan terbang) Didapatkan bahwa seluruh pekerja mempunyai nilai gizi yang borderline dan tidak ada perbedaan didalam keadaan fisik mereka, namun masih terdapat rata-rata 30 percent menderita anemia. Anemia banyak disertai dengan rendahnya kadar Iron darah pada pekerja di Rentang dan Seladarma hal ini tidak terdapat pada pekerja di Halim. (Table 4). Mengenai infeksi cacing terutama cacing tambang maka diseluruh pekerja menderita infeksi cacing tersebut tingkat pertama yaitu infeksi ringan yang tidak akan mempengaruhi keadaan fisik kecuali hanya kekurangan Iron didalam darah. Untuk mengetahui kemampuan bekerja maka telah dipakai Harvard Step Test Scores selama 5 menit. Dan ternyata bila pekerja-pekerja tersebut dibagi dua group yaitu yang diatas dan yang dibawah nilai Hb. 11 Gm/100 ml maka terdapat perbedaan yang menyolok sekali atas kemampuan pekerja tersebut didalam melakukan test fisik. Hal ini sesuai dengan penyelidikan Veteri. Perlu juga disini diketahui bahwa pekerja berasal dari Rentang dan Seladarma lebih banyak menggunakan tenaga kaki oleh karena selalu naik dan turun canal. Kesimpulan penyelidikan ini adalah adanya pengaruh yang positip antara faktor makanan dan infeksi cacing dengan kemampuan bekerja yang dewasa ini amat diperlukan didalam pembangunan negara

    A REPEATED MEASURES ANALYSIS OF THE EFFECT OF VEGETATIVE BUFFERS ON CONTAMINANT RUNOFF FROM BERMUDAGRASS TURF

    Get PDF
    A repeated measures analysis was conducted on a set of data from a multi-year study to assess the effect of vegetative buffers on the surface runoff of selected herbicides and nutrients. Multiplicative models describing the observed behavior of runoff concentration over time for buffered and non-buffered plots were fitted on a log-transformed scale using linear mixed models with PROC MIXED in PC SAS version 6.11. A spatial power covariance structure was used. Additional models for contaminant mass flow rates were fitted to evaluate the effect of buffers on total runoff mass

    Measuring the spin of the primary black hole in OJ287

    Full text link
    The compact binary system in OJ287 is modelled to contain a spinning primary black hole with an accretion disk and a non-spinning secondary black hole. Using Post Newtonian (PN) accurate equations that include 2.5PN accurate non-spinning contributions, the leading order general relativistic and classical spin-orbit terms, the orbit of the binary black hole in OJ287 is calculated and as expected it depends on the spin of the primary black hole. Using the orbital solution, the specific times when the orbit of the secondary crosses the accretion disk of the primary are evaluated such that the record of observed outbursts from 1913 up to 2007 is reproduced. The timings of the outbursts are quite sensitive to the spin value. In order to reproduce all the known outbursts, including a newly discovered one in 1957, the Kerr parameter of the primary has to be 0.28±0.080.28 \pm 0.08. The quadrupole-moment contributions to the equations of motion allow us to constrain the `no-hair' parameter to be 1.0 ± 0.31.0\:\pm\:0.3 where 0.3 is the one sigma error. This supports the `black hole no-hair theorem' within the achievable precision. It should be possible to test the present estimate in 2015 when the next outburst is due. The timing of the 2015 outburst is a strong function of the spin: if the spin is 0.36 of the maximal value allowed in general relativity, the outburst begins in early November 2015, while the same event starts in the end of January 2016 if the spin is 0.2Comment: 12 pages, 6 figure

    Measuring Black Hole Spin in OJ287

    Full text link
    We model the binary black hole system OJ287 as a spinning primary and a non-spinning secondary. It is assumed that the primary has an accretion disk which is impacted by the secondary at specific times. These times are identified as major outbursts in the light curve of OJ287. This identification allows an exact solution of the orbit, with very tight error limits. Nine outbursts from both the historical photographic records as well as from recent photometric measurements have been used as fixed points of the solution: 1913, 1947, 1957, 1973, 1983, 1984, 1995, 2005 and 2007 outbursts. This allows the determination of eight parameters of the orbit. Most interesting of these are the primary mass of 1.84⋅1010M⊙1.84\cdot 10^{10} M_\odot, the secondary mass 1.46⋅108M⊙1.46\cdot 10^{8} M_\odot, major axis precession rate 39∘.139^\circ.1 per period, and the eccentricity of the orbit 0.70. The dimensionless spin parameter is 0.28 ± 0.010.28\:\pm\:0.01 (1 sigma). The last parameter will be more tightly constrained in 2015 when the next outburst is due. The outburst should begin on 15 December 2015 if the spin value is in the middle of this range, on 3 January 2016 if the spin is 0.25, and on 26 November 2015 if the spin is 0.31. We have also tested the possibility that the quadrupole term in the Post Newtonian equations of motion does not exactly follow Einstein's theory: a parameter qq is introduced as one of the 8 parameters. Its value is within 30% (1 sigma) of the Einstein's value q=1q = 1. This supports the no−hairtheoremno-hair theorem of black holes within the achievable precision. We have also measured the loss of orbital energy due to gravitational waves. The loss rate is found to agree with Einstein's value with the accuracy of 2% (1 sigma).Comment: 12 pages, 4 figures, IAU26

    Germline 16p11.2 Microdeletion Predisposes to Neuroblastoma

    Get PDF
    Neuroblastoma is a cancer of the developing sympathetic nervous system. It is diagnosed in 600–700 children per year in the United States and accounts for 12% of pediatric cancer deaths. Despite recent advances in our understanding of this malignancy's complex genetic architecture, the contribution of rare germline variants remains undefined. Here, we conducted a genome-wide analysis of large (>500 kb), rare (<1%) germline copy number variants (CNVs) in two independent, multi-ethnic cohorts totaling 5,585 children with neuroblastoma and 23,505 cancer-free control children. We identified a 550-kb deletion on chromosome 16p11.2 significantly enriched in neuroblastoma cases (0.39% of cases and 0.03% of controls; p = 3.34 × 10−9). Notably, this CNV corresponds to a known microdeletion syndrome that affects approximately one in 3,000 children and confers risk for diverse developmental phenotypes including autism spectrum disorder and other neurodevelopmental disorders. The CNV had a substantial impact on neuroblastoma risk, with an odds ratio of 13.9 (95% confidence interval = 5.8–33.4). The association remained significant when we restricted our analysis to individuals of European ancestry in order to mitigate potential confounding by population stratification (0.42% of cases and 0.03% of controls; p = 4.10 × 10−8). We used whole-genome sequencing (WGS) to validate the deletion in paired germline and tumor DNA from 12 cases. Finally, WGS of four parent-child trios revealed that the deletion primarily arose de novo without maternal or paternal bias. This finding expands the clinical phenotypes associated with 16p11.2 microdeletion syndrome to include cancer, and it suggests that disruption of the 16p11.2 region may dysregulate neurodevelopmental pathways that influence both neurological phenotypes and neuroblastoma

    Preparation and Evaluation of Rice Bran-Modified Urea Formaldehyde as Environmental Friendly Wood Adhesive

    Get PDF
    In this study, defatted rice bran (RB) is used to prepare an environmentally friendly adhesive through chemical modifications. The RB is mixed with distilled water with ratios of 1:5 and 1:4 to prepare Type A and Type B adhesives, respectively having pH of 6, 8 and 10. Type A adhesive is prepared by treating RB with 1% potassium permanganate and 4% poly(vinyl alcohol), whereas Type B is formulated by adding 17.3% formaldehyde and 5.7% urea to RB. Viscosity, gel time, solid content, shear strength, Fourier transform infrared (FTIR) spectroscopy is carried out, and glass transition temperature (T-g), and activation energy (E-a) are determined to evaluate the performance of the adhesives. E-a data reveal that adhesives prepared at mild alkaline (pH 8) form long-chain polymers. Gel time is higher in the fabricated adhesives than that of the commercial urea formaldehyde (UF). FTIR data suggest that functional groups of the raw RB are chemically modified, which enhances the bondability of the adhesives. Shear strength data indicates that bonding strength increases with increasing pH. Similar results are also observed for physical and mechanical properties of fabricated particleboards with the adhesives. The results demonstrate that RB-based adhesives can be used as a potential alternative to currently used UF-based resin
    • …
    corecore