469 research outputs found
Does the Boltzmann principle need a dynamical correction?
In an attempt to derive thermodynamics from classical mechanics, an
approximate expression for the equilibrium temperature of a finite system has
been derived [M. Bianucci, R. Mannella, B. J. West, and P. Grigolini, Phys.
Rev. E 51, 3002 (1995)] which differs from the one that follows from the
Boltzmann principle S = k log (Omega(E)) via the thermodynamic relation 1/T=
dS/dE by additional terms of "dynamical" character, which are argued to correct
and generalize the Boltzmann principle for small systems (here Omega(E) is the
area of the constant-energy surface). In the present work, the underlying
definition of temperature in the Fokker-Planck formalism of Bianucci et al. is
investigated and shown to coincide with an approximate form of the
equipartition temperature. Its exact form, however, is strictly related to the
"volume" entropy S = k log (Phi(E)) via the thermodynamic relation above for
systems of any number of degrees of freedom (Phi(E) is the phase space volume
enclosed by the constant-energy surface). This observation explains and
clarifies the numerical results of Bianucci et al. and shows that a dynamical
correction for either the temperature or the entropy is unnecessary, at least
within the class of systems considered by those authors. Explicit analytical
and numerical results for a particle coupled to a small chain (N~10) of quartic
oscillators are also provided to further illustrate these facts.Comment: REVTeX 4, 10 pages, 2 figures. Accepted to J. Stat. Phy
Perancangan Buku Wisata Kuliner Pulau Lombok Dan Promosinya
Pulau Lombok merupakan sebuah Pulau di Provinsi Nusa Tenggara Barat yang memiliki banyak potensi wisata. Mulai dari potensi wisata alamnya yang indah serta potensi wisata kuliner khasnya yang nikmat dan berbeda dengan kuliner-kuliner di tempat lain. Namun, banyak masyarakat dan wisatawan yang masih belum mengetahui ragam jenis kuliner khas yang terdapat di Lombok. Oleh karena itu dibuat satu perancangan buku mengenai aneka kuliner yang ada di Pulau Lombok sekaligus menjadi media promosi untuk memperkenalkan kuliner khas Pulau Lombok
Uji Kefektifan Atraktan oryza sativa, capsicum annum, trachisperum roxburgianum pada Trapping nyamuk Aedes Aegypti
Nyamuk Aedes aegypti merupakan vector penularan demam berdarah dengue. Sampai saat ini belum ada cara yang efektif untuk mengatasi penyakit DBD karena belum ditemukan obat anti virus dengue. Penanggulangan penyakit DBD saat ini yaitu dengan menurunkan kepadatan populasi nyamuk Aedesa egypti salah satunya dengan alat penjebak nnyamuk (Trapping) dengan media atraktan. Namun, saat ini belum diketahui konsentrasi yang paling efektif dari atraktan oryza sativa (jerami), capsicum annum(cabe merah), dan trachisperum roxburgianum (jinten) untuk menjebak nyamuk. Untuk itu perlu diketahui berapa konsentrasi yang paling efektif dari atraktan oryza sativa (jerami), capsicum annum (cabai merah), dan trachysperum roxburgianum (jinten) untuk menjebak nyamuk. Metode penelitian dilakukan dengan melakukan uji efektifitas ketiga jenis atraktan dengan konsenstrasi 2,5 %, 5%, 10%, 15%, dan 20%, dengan melakukan lima kali pengulangan. Berdasarkan uji beda didapatkan bahwa, konsentrasi 15 % pada atraktan capsicum annum (cabai merah) p-value 0,009 dan konsentrasi 20% pada oryza sativa (jerami) p-value 0,020 paling baik memerangkap nyamuk Aedes Aegypti pada trapping. Konsentrasi atraktan trachysperum roxburgianum tidak berbeda nyata dengan kontrol p-value 0,250 dalam memerangkap nyamuk Aedes aegypti. Kata Kunci : Atraktan, Trapping, Aedes aegypt
Adiabatic invariance with first integrals of motion
The construction of a microthermodynamic formalism for isolated systems based
on the concept of adiabatic invariance is an old but seldom appreciated effort
in the literature, dating back at least to P. Hertz [Ann. Phys. (Leipzig) 33,
225 (1910)]. An apparently independent extension of such formalism for systems
bearing additional first integrals of motion was recently proposed by Hans H.
Rugh [Phys. Rev. E 64, 055101 (2001)], establishing the concept of adiabatic
invariance even in such singular cases. After some remarks in connection with
the formalism pioneered by Hertz, it will be suggested that such an extension
can incidentally explain the success of a dynamical method for computing the
entropy of classical interacting fluids, at least in some potential
applications where the presence of additional first integrals cannot be
ignored.Comment: 2 pages, no figures (REVTeX 4
Controlled Interference Generation for Wireless Coexistence Research
In recent years, we have witnessed a proliferation of wireless technologies and devices operating in the unlicensed bands. The resulting escalation of wireless demand has put enor-mous pressure on available spectrum. This raises a unique set of communication challenges, notably co-existence, Cross Technology Interference (CTI), and fairness amidst high un-certainty and scarcity of interference-free channels. Conse-quently, there is a strong need for understanding and debug-ging the performance of existing wireless protocols and sys-tems under various patterns of interference. Therefore, we need to augment testbeds with tools that can enable repeat-able generation of realistic interference patterns. This would primarily facilitate wireless coexistence research experimen-tation. The heterogeneity of the existing wireless devices and protocols operating in the unlicensed bands makes in-terference hard to model. Meanwhile, researchers working on wireless coexistence generally use interference generated from various radio appliances. The lack of a systematic way of controlling these appliances makes it inconvenient to run experiments, particularly in remote testbeds. In this pa-per, we present a Controlled Interference Generator (CIG) framework for wireless networks. In the design of CIG, we consider a unified approach that incorporates a careful se-lection of interferer technologies (implemented in software), to expose networks to realistic interference patterns. We validate the resemblance of interference generated by CIG and interference from represented RF devices, by showing the accuracy in temporal and spectral domains
Grapevine leafroll-associated virus 3.
Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management
UV-Light-Tunable p-/n-Type Chemiresistive Gas Sensors Based on Quasi-1D TiS\u3csub\u3e3\u3c/sub\u3e Nanoribbons: Detection of Isopropanol at ppm Concentrations
The growing demand of society for gas sensors for energy-efficient environmental sensing stimulates studies of new electronic materials. Here, we investigated quasi-one-dimensional titanium trisulfide (TiS3) crystals for possible applications in chemiresistors and on-chip multisensor arrays. TiS3 nanoribbons were placed as a mat over a multielectrode chip to form an array of chemiresistive gas sensors. These sensors were exposed to isopropanol as a model analyte, which was mixed with air at low concentrations of 1–100 ppm that are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit. The tests were performed at room temperature (RT), as well as with heating up to 110 oC, and under an ultraviolet (UV) radiation at λ = 345 nm. We found that the RT/UV conditions result in a n-type chemiresistive response to isopropanol, which seems to be governed by its redox reactions with chemisorbed oxygen species. In contrast, the RT conditions without a UV exposure produced a p-type response that is possibly caused by the enhancement of the electron transport scattering due to the analyte adsorption. By analyzing the vector signal from the entire on-chip multisensor array, we could distinguish isopropanol from benzene, both of which produced similar responses on individual sensors. We found that the heating up to 110 oC reduces both the sensitivity and selectivity of the sensor array
UV-Light-Tunable p-/n-Type Chemiresistive Gas Sensors Based on Quasi-1D TiS3 Nanoribbons: Detection of Isopropanol at ppm Concentrations
The growing demand of society for gas sensors for energy-efficient environmental sensing stimulates studies of new electronic materials. Here, we investigated quasi-one-dimensional titanium trisulfide (TiS(3)) crystals for possible applications in chemiresistors and on-chip multisensor arrays. TiS(3) nanoribbons were placed as a mat over a multielectrode chip to form an array of chemiresistive gas sensors. These sensors were exposed to isopropanol as a model analyte, which was mixed with air at low concentrations of 1–100 ppm that are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit. The tests were performed at room temperature (RT), as well as with heating up to 110 °C, and under an ultraviolet (UV) radiation at λ = 345 nm. We found that the RT/UV conditions result in a n-type chemiresistive response to isopropanol, which seems to be governed by its redox reactions with chemisorbed oxygen species. In contrast, the RT conditions without a UV exposure produced a p-type response that is possibly caused by the enhancement of the electron transport scattering due to the analyte adsorption. By analyzing the vector signal from the entire on-chip multisensor array, we could distinguish isopropanol from benzene, both of which produced similar responses on individual sensors. We found that the heating up to 110 °C reduces both the sensitivity and selectivity of the sensor array
An experimental and numerical investigation on the process efficiency of the focused TIG welding of Inconel 718 thick plates
A combined experimental and numerical approach was adopted to investigate the focused tungsten inert gas (TIG) welding process by producing bead-on-plate welds in Inconel 718 plates. Experimental investigations were carried out by means of thermocouple measurements and optical macrographs of the weld cross-section. Three dimensional finite element (FE) simulations were conducted using the commercial specialized FE software Sysweld in order to predict the thermal field induced by the process in the plates. The work presents an approach to investigate the process efficiency and calibrate the heat source model in order to produce a full thermal characterization the plasmatron welding apparatus
The use of biomedicine, complementary and alternative medicine, and ethnomedicine for the treatment of epilepsy among people of South Asian origin in the UK
Studies have shown that a significant proportion of people with epilepsy use complementary and alternative medicine (CAM). CAM use is known to vary between different ethnic groups and cultural contexts; however, little attention has been devoted to inter-ethnic differences within the UK population. We studied the use of biomedicine, complementary and alternative medicine, and ethnomedicine in a sample of people with epilepsy of South Asian origin living in the north of England.
Interviews were conducted with 30 people of South Asian origin and 16 carers drawn from a sampling frame of patients over 18 years old with epilepsy, compiled from epilepsy registers and hospital databases. All interviews were tape-recorded, translated if required and transcribed. A framework approach was adopted to analyse the data.
All those interviewed were taking conventional anti-epileptic drugs. Most had also sought help from traditional South Asian practitioners, but only two people had tried conventional CAM. Decisions to consult a traditional healer were taken by families rather than by individuals with epilepsy. Those who made the decision to consult a traditional healer were usually older family members and their motivations and perceptions of safety and efficacy often differed from those of the recipients of the treatment. No-one had discussed the use of traditional therapies with their doctor. The patterns observed in the UK mirrored those reported among people with epilepsy in India and Pakistan.
The health care-seeking behaviour of study participants, although mainly confined within the ethnomedicine sector, shared much in common with that of people who use global CAM. The appeal of traditional therapies lay in their religious and moral legitimacy within the South Asian community, especially to the older generation who were disproportionately influential in the determination of treatment choices. As a second generation made up of people of Pakistani origin born in the UK reach the age when they are the influential decision makers in their families, resort to traditional therapies may decline. People had long experience of navigating plural systems of health care and avoided potential conflict by maintaining strict separation between different sectors. Health care practitioners need to approach these issues with sensitivity and to regard traditional healers as potential allies, rather than competitors or quacks
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