The O–H Band in the Vapors of Some Organic Acids and of Tertiary Amyl Alcohol in the Region λ9700

Absorption bands corresponding to the third harmonic of the O–H vibration have been observed in the vapors of formic, acetic, propionic and trichloracetic acids, with centers at about 10202.8, 10242, 10235 and 10250 cm^(‐1), respectively. Formic acid alone gave a band with resolvable fine structure, but this has unusual features and may be described as a hybrid. The simultaneous presence of characteristics similar to those of both "perpendicular" and "parallel" type bands of symmetrical molecules is due to the fact that the change in electric moment produced by the O–H vibration has components along two of the principal axes of the molecule. Rotational constants for the formic acid molecule have been evaluated and the moments of inertia were found to be 85.2, 74.4 and 10.81×10^(‐40) g cm^2. The structures of the organic acid molecules are discussed and a comparison is made with nitric acid. In tert‐amyl alcohol a band with single broad maximum at about 10414 cm^(‐1) was found

The Absorption Spectrum of Methyl Alcohol Vapor in the Photographic Infrared

The absorption of methyl alcohol vapor in the photographic infrared has been explored under low dispersion. Absorption regions were found at lambda9500 and lambda7300, which correspond to two harmonics of the O[Single Bond]H vibration, and at lambda12,000 which is a harmonic of the C[Single Bond]H vibration. The two O[Single Bond]H harmonic bands were investigated under high dispersion and a somewhat complex rotational structure was resolved. The complete interpretation of the spectrum must be postponed until the theory of the torsion oscillator rotator is further developed

Spectroscopic Studies of the Hydrogen Bond. II. The Shift of the O[Single Bond]H Vibrational Frequency in the Formation of the Hydrogen Bond

The association spectra of a number of acids and alcohols in the region lambdalambda9000–11,000 have been observed both in solution and in the pure liquids. In each case a broad band with maximum near lambda10,000 was observed while in the alcohols an additional weaker band near lambda9000 appears to be present. Evidence is presented that the lambda10,000 band is to be identified with the O[Single Bond]H group. This evidence includes the behavior of the association band with change in concentration and temperature and its presence in several substances in which absorption other than that due to the O[Single Bond]H group is practically absent in the region studied. New evidence is given that a weak intermolecular hydrogen bond is formed between acetone and methyl alcohol. It is pointed out that the presence of absorption in the narrow O[Single Bond]H bands is not to be taken as evidence of the absence of hydrogen bonds in case the absorption is weak. The character of the O[Single Bond]H absorption in the case of intermolecular hydrogen bonds is discussed and the probable nature of the spectrum in the case of an intramolecular bond is indicated. A relation between the energy of the hydrogen bond and the shift of the O[Single Bond]H vibrational frequency is pointed out and its use is suggested in the interpretation of certain spectra

A lower bound for the BCS functional with boundary conditions at infinity

We consider a many-body system of fermionic atoms interacting via a local pair potential and subject to an external potential within the framework of BCS theory. We measure the free energy of the whole sample with respect to the free energy of a reference state which allows us to define a BCS functional with boundary conditions at infinity. Our main result is a lower bound for this energy functional in terms of expressions that typically appear in Ginzburg-Landau functionals.Comment: 32 page

Optimized broad-histogram simulations for strong first-order phase transitions: Droplet transitions in the large-Q Potts model

The numerical simulation of strongly first-order phase transitions has remained a notoriously difficult problem even for classical systems due to the exponentially suppressed (thermal) equilibration in the vicinity of such a transition. In the absence of efficient update techniques, a common approach to improve equilibration in Monte Carlo simulations is to broaden the sampled statistical ensemble beyond the bimodal distribution of the canonical ensemble. Here we show how a recently developed feedback algorithm can systematically optimize such broad-histogram ensembles and significantly speed up equilibration in comparison with other extended ensemble techniques such as flat-histogram, multicanonical or Wang-Landau sampling. As a prototypical example of a strong first-order transition we simulate the two-dimensional Potts model with up to Q=250 different states on large systems. The optimized histogram develops a distinct multipeak structure, thereby resolving entropic barriers and their associated phase transitions in the phase coexistence region such as droplet nucleation and annihilation or droplet-strip transitions for systems with periodic boundary conditions. We characterize the efficiency of the optimized histogram sampling by measuring round-trip times tau(N,Q) across the phase transition for samples of size N spins. While we find power-law scaling of tau vs. N for small Q \lesssim 50 and N \lesssim 40^2, we observe a crossover to exponential scaling for larger Q. These results demonstrate that despite the ensemble optimization broad-histogram simulations cannot fully eliminate the supercritical slowing down at strongly first-order transitions.Comment: 11 pages, 12 figure

Internet-based psychoeducation for bipolar disorder: a qualitative analysis of feasibility, acceptability and impact

<p>Background: In a recent exploratory randomised trial we found that a novel, internet-based psychoeducation programme for bipolar disorder (Beating Bipolar) was relatively easy to deliver and had a modest effect on psychological quality of life. We sought to explore the experiences of participants with respect to feasibility, acceptability and impact of Beating Bipolar.</p> <p>Methods: Participants were invited to take part in a semi-structured interview. Thematic analysis techniques were employed; to explore and describe participants’ experiences, the data were analysed for emerging themes which were identified and coded.</p> <p>Results: The programme was feasible to deliver and acceptable to participants where they felt comfortable using a computer. It was found to impact upon insight into illness, health behaviour, personal routines and positive attitudes towards medication. Many participants regarded the programme as likely to be most beneficial for those recently diagnosed.</p> <p>Conclusions: An online psychoeducation package for bipolar disorder, such as Beating Bipolar, is feasible and acceptable to patients, has a positive impact on self-management behaviours and may be particularly suited to early intervention. Alternative (non-internet) formats should also be made available to patients.</p&gt

Further empirical evidence for the non-linearity of the period-luminosity relations as seen in the Large Magellanic Cloud Cepheids

(abridged) Recent studies, using OGLE data for LMC Cepheids in the optical, strongly suggest that the period-luminosity (PL) relation for the Large Magellanic Cloud (LMC) Cepheids shows a break or non-linearity at a period of 10 days. In this paper we apply statistical tests, the chi-square test and the F-test, to the Cepheid data from the MACHO project to test for a non-linearity of the V- and R-band PL relations at 10 days, and extend these tests to the near infrared (JHK-band) PL relations with 2MASS data. We correct the extinction for these data by applying an extinction map towards the LMC. The statistical test we use, the F-test, is able to take account of small numbers of data points and the nature of that data on either side of the period cut at 10 days. With our data, the results we obtained imply that the VRJH-band PL relations are non-linear around a period of 10 days, while the K-band PL relation is (marginally) consistent with a single-line regression. The choice of a period of 10 days, around which this non-linearity occurs, is consistent with the results obtained when this "break" period is estimated from the data. Long period Cepheids are supplemented from the literature to increase our sample size. The photometry of these long period Cepheids is compared with our data and no trend with period is found. Our main results remain unchanged when we supplement our dataset with these long period Cepheids. By examining our data at maximum light, we also suggest arguments why errors in reddening are unlikely to be responsible for our results. The non-linearity of the mean V-band PL relation as seen in both of the OGLE and MACHO data, using different extinction maps, suggests that this non-linearity is real.Comment: 18 pages, 10 tables, 7 figures. MNRAS accepte