Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\nu_1+\nu_2+\nu_3+\nu_4^1+\nu_5^{-1}$ in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) $\text{cm}^{-1}$, the rotational parameter $B$ was 1.162222 $\text{cm}^{-1}$, and the quartic centrifugal distortion parameter $D$ was 3.998(62)$\times 10^{-6} \text{cm}^{-1}$, where the numbers in the parenthesis are one-standard errors in the least significant digits

Wave function engineering in quantum dot-ring nanostructures

Modern nanotechnology allows producing, depending on application, various quantum nanostructures with the desired properties. These properties are strongly influenced by the confinement potential which can be modified, e.g., by electrical gating. In this paper we analyze a nanostructure composed of a quantum dot surrounded by a quantum ring. We show that depending on the details of the confining potential the electron wave functions can be located in different parts of the structure. Since the properties of such a nanostructure strongly depend on the distribution of the wave functions, varying the applied gate voltage one can easily control them. In particular, we illustrate the high controllability of the nanostructure by demonstrating how its coherent, optical, and conducting properties can be drastically changed by a small modification of the confining potential.Comment: 8 pages, 10 figures, 2 tables, revte

Change in Job Strain as a Predictor of Change in Insomnia Symptoms: Analyzing Observational Data as a Non-randomized Pseudo-Trial

Study objectives: To examine whether change in job strain leads to change in insomnia symptoms. Methods: Among 24873 adults (82% women, mean age 44 years) who participated in a minimum of three consecutive study waves (2000–2012), job strain was assessed at the first and second wave and insomnia symptoms at all three waves. We analyzed observational data as a “pseudo-trial” including participants with no job strain in the first wave and no insomnia symptoms in the first and second wave (n = 7354) to examine whether the onset of job strain between the first and second waves predicted the onset of insomnia symptoms in the third wave. We used a corresponding approach, including those with job strain in the first wave and insomnia symptoms in the first and second wave (n = 2332), to examine whether the disappearance of job strain between the first two waves predicted remission of insomnia symptoms in the third wave. Results: The onset of job strain predicted the onset of subsequent insomnia symptoms after adjustment for sex, age, marital status, education, smoking, physical activity, alcohol consumption, body mass index, and comorbidities (odds ratio compared to no onset of job strain 1.32, 95% CI 1.16–1.51). The disappearance of job strain was associated with lower odds of repeated insomnia symptoms (odds ratio compared to no disappearance of job strain 0.78, 95% CI 0.65–0.94). Further adjustment for shift work or sleep apnea did not change these associations. Conclusions: These results suggest that job strain is a modifiable risk factor for insomnia symptoms

Change in neighborhood disadvantage and change in smoking behaviors in adults: a longitudinal, within-individual study

BACKGROUND: Evidence for an association between neighborhood disadvantage and smoking is mixed and mainly based on cross-sectional studies. To shed light on the causality of this association we examined whether change in neighborhood socioeconomic disadvantage is associated with within-individual change in smoking behaviors. METHODS: The study population comprised participants of the Finnish Public Sector study who reported a change in their smoking behavior between surveys in 2008/09 and 2012/13. We linked participants' residential addresses to a total population database on neighborhood disadvantage with 250 × 250m resolution. The outcome variables were changes in smoking status (being a smoker vs. not) as well as the intensity (heavy/moderate vs. light smoker). We used longitudinal case-crossover design, a method that accounts for time-invariant confounders by design. We adjusted models for time-varying covariates. RESULTS: Of the 3443 participants, 1714 quit while 967 began to smoke between surveys. Smoking intensity increased among 398 and decreased among 364 participants. The level of neighborhood disadvantage changed for 1078 participants because they moved residence. Increased disadvantage was associated with increased odds of being a smoker (odds ratio (OR) of taking up smoking 1.23 (95% CI 1.04-1.47) per 1 standard deviation (SD) increase in standardized national disadvantage score). OR for being a heavy/moderate (vs. light) smoker was 1.14 (95% CI 0.85-1.52) when disadvantage increased by 1 SD. CONCLUSIONS: These within-individual results link an increase in neighborhood socioeconomic disadvantage, due to move in residence, with subsequent smoking behaviors

Fermi resonance-algebraic model for molecular vibrational spectra

A Fermi resonance-algebraic model is proposed for molecular vibrations, where a U(2) algebra is used for describing the vibrations of each bond, and Fermi resonances between stretching and bending modes are taken into account. The model for a bent molecule XY_2 and a molecule XY_3 is successfully applied to fit the recently observed vibrational spectrum of the water molecule and arsine (AsH_3), respectively, and results are compared with those of other models. Calculations show that algebraic approaches can be used as an effective method for describing molecular vibrations with small standard deviations

Association Between Distance From Home to Tobacco Outlet and Smoking Cessation and Relapse

IMPORTANCE: Reduced availability of tobacco outlets is hypothesized to reduce smoking, but longitudinal evidence on this issue is scarce. OBJECTIVE: To examine whether changes in distance from home to tobacco outlet are associated with changes in smoking behaviors. DESIGN, SETTING, AND PARTICIPANTS: The data from 2 prospective cohort studies included geocoded residential addresses, addresses of tobacco outlets, and responses to smoking surveys in 2008 and 2012 (the Finnish Public Sector [FPS] study, n = 53 755) or 2003 and 2012 (the Health and Social Support [HeSSup] study, n = 11 924). All participants were smokers or ex-smokers at baseline. We used logistic regression in between-individual analyses and conditional logistic regression in case-crossover design analyses to examine change in walking distance from home to the nearest tobacco outlet as a predictor of quitting smoking in smokers and smoking relapse in ex-smokers. Study-specific estimates were pooled using fixed-effect meta-analysis. EXPOSURES: Walking distance from home to the nearest tobacco outlet. MAIN OUTCOMES AND MEASURES: Quitting smoking and smoking relapse as indicated by self-reported current and previous smoking at baseline and follow-up. RESULTS: Overall, 20 729 men and women (age range 18-75 years) were recruited. Of the 6259 and 2090 baseline current smokers, 1744 (28%) and 818 (39%) quit, and of the 8959 and 3421 baseline ex-smokers, 617 (7%) and 205 (6%) relapsed in the FPS and HeSSup studies, respectively. Among the baseline smokers, a 500-m increase in distance from home to the nearest tobacco outlet was associated with a 16% increase in odds of quitting smoking in the between-individual analysis (pooled odds ratio, 1.16; 95% CI, 1.05-1.28) and 57% increase in within-individual analysis (pooled odds ratio, 1.57; 95% CI, 1.32-1.86), after adjusting for changes in self-reported marital and working status, substantial worsening of financial situation, illness in the family, and own health status. Increase in distance to the nearest tobacco outlet was not associated with smoking relapse among the ex-smokers. CONCLUSIONS AND RELEVANCE: These data suggest that increase in distance from home to the nearest tobacco outlet may increase quitting among smokers. No effect of change in distance on relapse in ex-smokers was observed

Magnetic field dependence of the exciton energy in a quantum disk

The groundstate energy and binding energy of an exciton, confined in a^M quantum disk, are calculated as a function of an external magnetic field. The confinement potential is a hard wall of finite height. The diamagnetic shift is investigated for magnetic fields up to 40$T$. Our results are applied to $In_{y}Al_{1-y}As/Al_{x}Ga_{1-x}As$ self-assembled quantum dots and very good agreement with experiments is obtained. Furthermore, we investigated the influence of the dot size on the diamagnetic shift by changing the disk radius. The exciton excited states are found as a function of the magnetic field. The relative angular momentum is not a quantum number and changes with the magnetic field strength.Comment: 10 pages, 17 figure

Donor Centers and Absorption Spectra in Quantum Dots

We have studied the electronic properties and optical absorption spectra of three different cases of donor centers, D^{0}, D^{-} and D^{2-}, which are subjected to a perpendicular magnetic field, using the exact diagonalization method. The energies of the lowest lying states are obtained as function of the applied magnetic field strength B and the distance zeta between the positive ion and the confinement xy-plane. Our calculations indicate that the positive ion induces transitions in the ground-state, which can be observed clearly in the absorption spectra, but as zeta goes to 0 the strength of the applied magnetic field needed for a transition to occur tends to infinity.Comment: 5 pages, 4 figures, REVTeX 4, gzipped tar fil

Selection and sizing of the instrumentation in process industries

Abstract. Instrumentation engineering, that is selections and sizing of measuring and control instruments and methods, as well as the selection and design of their installation, is an important aspect of plant automation engineering. The aim of this master’s thesis was to produce a generally applicable, concise, and clear engineering guide for instrumentation that could be used in all industrial sectors. The research objectives were to explore factors influencing instrumentation, the selection and procurement process, as well as commonly used devices and methods and their properties. To achieve the objectives of the study, in addition to theoretical literature based research, and empirical research was conducted by interviewing professionals in the field. The selection of instrumentation is a sum of many factors, but by prioritizing these factors based on their flexibility and significance, the selection process can be rationalized. The selection and procurement process can be carried out either based on detailed process information in the final stages of design, or by establishing framework contracts with device suppliers in the early phases of the project, relying on preliminary design information and reference projects. Based on the results, it was concluded that instrumentation technology is continuously evolving but the associated literature stands the test of time. The physical phenomena behind the techniques remain the same. Research is not directly suitable for a project engineering guide, but it can be used as support for design work and as educational material.Instrumentoinnin valinta ja mitoitus prosessiteollisuudessa. Tiivistelmä. Instrumentointisuunnittelu, joka kattaa mittaus- ja säätöinstrumenttien valinnan ja mitoituksen, sekä niiden asennuksen valinnan ja suunnittelun, on tärkeä osa laitosautomaatiosuunnittelua. Tämän diplomityön tavoitteena oli tuottaa yleisesti soveltuva, tiivis ja selkeä suunnitteluohje instrumentointiin, jota voitaisiin käyttää kaikilla teollisuuden aloilla. Tutkimuksen tavoitteina oli selvittää instrumentointiin vaikuttavia tekijöitä, laitteiden valinta ja hankintaprosessia, sekä yleisesti käytettyjä laitteita ja menetelmiä, sekä niiden ominaisuuksia. Tutkimustavoitteiden saavuttamiseksi, teoreettisen kirjallisuuteen perustuvan tutkimuksen lisäksi toteutettiin empiirinen tutkimus haastattelemalla alan ammattilaisia. Instrumenttien valinta on monen tekijän summa, mutta priorisoimalla nämä tekijät niiden joustavuuden ja tärkeyden perusteella valintaprosessia voidaan järkeistää. Valinta- ja hankintaprosessi voidaan toteuttaa joko yksityiskohtaisten prosessitietojen perusteella suunnittelun loppuvaiheessa tai tekemällä raamisopimuksia laitetoimittajien kanssa projektin alkuvaiheessa esisuunnittelutietoihin ja referenssiprojekteihin perustuen. Tulosten perusteella voidaan päätellä instrumentointiteknologian kehittyvän jatkuvasti, mutta siihen liittyvän kirjallisuuden kestävän aikaa. Fysikaaliset ilmiöt, joihin tekniikat perustuvat, eivät muutu. Tämä tutkimus ei sovellu suoraan projektien suunnitteluohjeeksi, mutta sitä voidaan käyttää suunnittelutyön tukena ja opetusmateriaalin

Effect of Subband Landau Level Coupling to the Linearly Dispersing Collective Mode in a Quantum Hall Ferromagnet

In a recent experiment (Phys. Rev. Lett. {\bf 87}, 036903 (2001)), Spielman et al observed a linearly dispersing collective mode in quantum Hall ferromagnet. While it qualitatively agrees with the Goldstone mode dispersion at small wave vector, the experimental mode velocity is slower than that calculated by previous theories by a factor about 0.55. A better agreement with the experimental data may possibly be achieved by taking the subband Landau level coupling into account due to the finiteness of the layer thickness. A novel coupling of quantum fluctuation to the tunneling is briefly discussed.Comment: 4 pages; published versio