520 research outputs found
Lattice thermal conductivity of graphene with conventionally isotopic defects
The thermal conductivity of doped graphene flake of finite size is
investigated with emphasis on the influence of mass of substituting atoms on
this property. It is shown that the graphene doping by small concentrations of
relatively heavy atoms results in a disproportionately impressive drop of
lattice thermal conductivity.Comment: 12 pages, 3 figure
AN ANALYSIS ON THE VIOLATION OF COOPERATIVE PRINCIPLES IN THE FILM AVENGERS
This research is an analysis on the violation of cooperative principles in the movie Avengers that also describes the type of violation of cooperative principle contained in every conversation in the movie. The research is conducted by using descriptive qualitative method. The subject of this research is the conversation that occurs in the movie Avengers, whilst the object of this research is the data containing forms of every conversation violations of the cooperative principle in the movie Avengers. The technique used in collecting data is called note technique. The data obtained is classified based on the form of violation of cooperative principles. The result of the research shows that the form of violation of the cooperative principle that occurs in the Avengers movie consists of four maxims: the maxim of quantity, the maxim of quality, the maxim of relevance, and the maxim of manner. The violation on the maxim of cooperation occurs because of the same knowledge held by the speech participants and the speech partners in discussing a problem, clarifying information, and changing the subject.Keywords: Violations of cooperative principles, maxim, movie, avengers
The Sandwich Generation Diner: Development of a Web-Based Health Intervention for Intergenerational Caregivers
Background: Women are disproportionately likely to assist aging family members; approximately 53 million in the United States are involved with the health care of aging parents, in-laws, or other relatives. The busy schedules of “sandwich generation” women who care for older relatives require accessible and flexible health education, including Web-based approaches. Objective: This paper describes the development and implementation of a Web-based health education intervention, The Sandwich Generation Diner, as a tool for intergenerational caregivers of older adults with physical and cognitive impairments. Methods: We used Bartholomew’s Intervention Mapping (IM) process to develop our theory-based health education program. Bandura’s (1997) self-efficacy theory provided the overarching theoretical model. Results: The Sandwich Generation Diner website features four modules that address specific health care concerns. Our research involves randomly assigning caregiver participants to one of two experimental conditions that are identical in the type of information provided, but vary significantly in the presentation. In addition to structured Web-based assessments, specific website usage data are recorded. Conclusions: The Sandwich Generation Diner was developed to address some of the informational and self-efficacy needs of intergenerational female caregivers. The next step is to demonstrate that this intervention is: (1) attractive and effective with families assisting older adults, and (2) feasible to embed within routine home health services for older adults
Low-temperature thermal conductivity in polycrystalline graphene
The low-temperature thermal conductivity in polycrystalline graphene is
theoretically studied. The contributions from three branches of acoustic
phonons are calculated by taking into account scattering on sample borders,
point defects and grain boundaries. Phonon scattering due to sample borders and
grain boundaries is shown to result in a -behaviour in the thermal
conductivity where varies between 1 and 2. This behaviour is found to
be more pronounced for nanosized grain boundaries.
PACS: 65.80.Ck, 81.05.ue, 73.43.C
Phonons and thermal transport in Si/SiO multishell nanotubes: Atomistic study
Thermal transport in the Si/SiO multishell nanotubes is investigated
theoretically. The phonon energy spectra are obtained using the atomistic
Lattice Dynamics approach. Thermal conductivity is calculated using the
Boltzmann transport equation within the relaxation time approximation.
Redistribution of the vibrational spectra in multishell nanotubes leads to a
decrease of the phonon group velocity and the thermal conductivity as compared
to homogeneous Si nanowires. Phonon scattering on the Si/SiO interfaces is
another key factor of strong reduction of the thermal conductivity in these
structures (down to 0.2 W/mK at room temperature). We demonstrate that phonon
thermal transport in Si/SiO nanotubes can be efficiently suppressed by a
proper choice of nanotube's geometrical parameters: lateral cross-section,
thickness and number of shells.Comment: 14 pages, 4 figure
Excitons in the wurtzite AlGaN/GaN quantum-well heterostructures
We have theoretically studied exciton states and photoluminescence spectra of
strained wurtzite AlGaN/GaN quantum-well heterostructures. The electron and
hole energy spectra are obtained by numerically solving the Schr\"odinger
equation, both for a single-band Hamiltonian and for a non-symmetrical 6-band
Hamiltonian. The deformation potential and spin-orbit interaction are taken
into account. For increasing built-in field, generated by the piezoelectric
polarization and by the spontaneous polarization, the energy of size
quantization rises and the number of size quantized electron and hole levels in
a quantum well decreases. The exciton energy spectrum is obtained using
electron and hole wave functions and two-dimensional Coulomb wave functions as
a basis. We have calculated the exciton oscillator strengths and identified the
exciton states active in optical absorption. For different values of the Al
content x, a quantitative interpretation, in a good agreement with experiment,
is provided for (i) the red shift of the zero-phonon photoluminescence peaks
for increasing the quantum-well width, (ii) the relative intensities of the
zero-phonon and one-phonon photoluminescence peaks, found within the
non-adiabatic approach, and (iii) the values of the photoluminescence decay
time as a function of the quantum-well width.Comment: 32 pages, 9 figure
Prarancangan Pabrik Bioetanol Dari Jerami Padi Dengan Proses Hidrolisis Dan Fermentasi Kapasitas 64.000 Kilo Liter/Tahun
Pabrik ini menggunakan jerami padi sebagai bahan baku. Emisi karbon dari bahan bakar alternatif ini yaitu lebih rendah daripada premium sehingga lebih ramah lingkungan.
Bioetanol dapat digunakan sebagai bahan baku industri turunan alkohol, bahan dasar industri farmasi, campuran bahan bakar untuk kendaraan dan lain-lain. Bioetanol yang dimanfaatkan sebagai campuran bahan bakar untuk kendaraan harus betul-betul kering dan anhydrous supaya tidak korosif, sehingga etanol/bioetanol harus mempunyai grade sebesar 99,5-100%-vol. Produksi jerami padi di Jawa Timur berkisar antara 10 juta ton pertahun. Dengan jumlah yang cukup besar tersebut, jerami padi yang merupakan limbah sisa saat padi dipanen, dapat menjadi salah satu alternatif bahan baku bioetanol yang cukup bagus di Indonesia.
Bioetanol dapat diperoleh melalui proses fermentasi yang melibatkan mikroorganisme. Mikroorganisme yang digunakan adalah Trichordema Reesei yang menghasilkan enzim selulase yang dapat memecah selulosa. Digunakan juga Zymomonas Mobilis yang dapat mengkorversi glukosa menjadi bioetanol. Sebelum proses fermentasi, umpan berupa jerami padi dimasukkan ke dalam tangki hidrolisis untuk memecah lignin. Proses yang dipilih adalah hidrolisis enzim. Setelah proses hidrolisis, masuk ke dalam proses fermentasi. Setelah kurun waktu tertentu dan proses fermentasi selesai, dilanjutkan dengan proses distilasi yang kemudian menuju proses adsorbsi menggunakan molecular sieve sehingga diperoleh bioetanol dengan kadar 99,5%.
Proses pembuatan bioetanol ini berlangsung selama 24 jam/hari, selama 330 hari/tahun dengan perencanaan sebagai berikut:
Kapasitas produksi : 64.000 kL/tahun
Bahan baku jerami padi : 4.077.921,29 ton/tahun
Pabrik bioetanol ini akan didirikan pada tahun 2018 di Kabupaten Malang, Jawa Timur. Karena berdekatan dengan bahan baku, dan adanya kemudahan dalam memenuhi kebutuhan air. Dari segi analisa ekonomi diperoleh hasil-hasil sebagai berikut :
Modal Tetap (FCI) : Rp. 100.517.092.113,88
Modal Kerja (WCI) : Rp. 17.738.310.373,04
Total Investasi (TCI) : Rp. 118.255.402.486,91
Internal Rate of Return : 62,84 %
Pay Out Time : 1,37 tahun
BEP : 42,32 %
Dari uraian di atas, secara teknis dan ekonomis, pabrik ini layak untuk didirikan
Exact summation of leading infrared logarithms in 2D effective field theories
A method of exact all-order summation of leading infrared logarithms in two
dimensional massless -type non-renormalizable effective field theories
(EFTs) is developed. The method is applied to the -symmetric EFT,
which is a two-dimensional sibling of the four dimensional sigma-model. For the first time the exact all-order summation of the
contributions (chiral logarithms) for the scattering amplitudes is performed in closed analytical form. The cases
when the resulting amplitudes turn to be meromorphic functions with an infinite
number of poles (Landau poles) are identified. This provides the first explicit
example of quasi-renormalizable field theories.Comment: 22 pages, 2 figure
Expecting the unexpected : Temporal expectation increases the flash-grab effect
Acknowledgments EvH, TB, KC, and HH were supported by the Australian Government through the Australian Research Council's Discovery Projects funding scheme (project DP180102268). PC was supported by grants from Dartmouth College and from Natural Sciences and Engineering Research Council Canada.Peer reviewedPublisher PD
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