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In this work we demonstrate hyperbranched nanostructures, grown by pulsed laser deposition, composed of one-dimensional anatase single crystals assembled in arrays of high aspect ratio hierarchical mesostructures. The proposed growth mechanism relies on a two-step process: self-assembly from the gas phase of amorphous TiO2clusters in a forest of tree-shaped hierarchical mesostructures with high aspect ratio; oriented crystallization of the branches upon thermal treatment. Structural and morphological characteristics can be optimized to achieve both high specific surface area for optimal dye uptake and broadband light scattering thanks to the microscopic feature size. Solid-state dye sensitized solar cells fabricated with arrays of hyperbranched TiO2nanostructures on FTO-glass sensitized with D102 dye showed a significant 66% increase in efficiency with respect to a reference mesoporous photoanode and reached a maximum efficiency of 3.96% (among the highest reported for this system). This result was achieved mainly thanks to an increase in photogenerated current directly resulting from improved light harvesting efficiency of the hierarchical photoanode. The proposed photoanode overcomes typical limitations of 1D TiO2nanostructures applied to ss-DSC and emerges as a promising foundation for next-generation high-efficiency solid-state devices comprosed of dyes, polymers, or quantum dots as sensitizers.

Following the International Law Commission Report on Fragmentation in International Law (IL), scholars have started to question whether such fragmentation could also have affected its subbranches, and, especially, international human rights law (IHRL). Due to the proliferation of both IHRL norms and institutions, especially at the regional level, this appeared to be a real possibility.

ABSTRACTThe International Covenant on Civil and Political Rights (ICCPR) and the regional human rights conventions do not explicitly prohibit discrimination based on sexual orientation, or provide the right to marry and have a family for same-sex couples, thus leaving an open margin of interpretation to their judicial and quasi-judicial enforcement bodies. However, regional courts and the Human Rights Committee (HRC) jurisprudence seems to have followed a path of convergence rather than fragmentation. This article will analyse the case-law of the regional judicial bodies and of the HRC on the matter through the lens of the prohibition of discrimination, assessing how such convergence has been reached and evaluating its nature. The analysis will reveal that beneath a seeming trend of convergence in the case outcomes, there are signs of a strong point of divergence and many threats of future fragmentation. In particular, there is a deep contrast between the European and the Inter-American Court of Human Rights in terms of prohibited discrimination based on sexual orientation. Moreover, the convergence reached among regional human rights bodies and the HRC hides vague and highly debated concepts and definitions on sensitive topics like marriage and adoption.

Understanding a drug candidate’s mechanism of action is crucial for its further development. However, kinetic schemes are often complex and multi-parametric, especially for proteins in oligomerization equilibria. Here, we demonstrate the use of particle swarm optimization (PSO) as a method to select between different sets of parameters that are too far apart in the parameter space to be found by conventional approaches. PSO is based upon the swarming of birds: each bird in the flock assesses multiple landing spots while at the same time sharing that information with its neighbors. We applied this approach to the kinetics of HSD17β13 enzyme inhibitors, which displayed unusually large thermal shifts. Thermal shift data for HSD17β13 indicated that the inhibitor shifted the oligomerization equilibrium toward the dimeric state. Validation of the PSO approach was provided by experimental mass photometry data. These results encourage further exploration of multi-parameter optimization algorithms as tools in drug discovery.

We investigate the loss mechanisms in hybrid photovoltaics based on blends of poly(3-hexylthiophene) with CdSe nanocrystals of various sizes. By combining the spectroscopic and electrical measurements on working devices as well as films, we identify that high trap-mediated recombination is responsible for the loss of photogenerated charge carriers in devices with small nanocrystals. In addition, we demonstrate that the reduced open-circuit voltage for devices with small nanocrystals is also caused by the traps.

Hybrid solar cells based on light absorbing semiconducting polymers infiltrated in nanocrystalline TiO2electrodes, have emerged as an attractive concept, combining benefits of both low material and processing costs with well controlled nano‐scale morphology. However, after over ten years of research effort, power conversion efficiencies remain around 0.5%. Here, a spectroscopic and device based investigation is presented, which leads to a new optimization route where by functionalization of the TiO2surface with a molecular electron acceptor promotes photoinduced electron transfer from a low‐band gap polymer(poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b0]dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadia‐zole)] (PCPDTBT) to the metal oxide. This boosts the infrared response and the power conversion efficiency to over 1%. As a further step, by “co‐functionalizing” the TiO2surface with the electron acceptor and an organic dye‐sensitizer, panchromatic spectral photoresponse is achieved in the visible to near‐IR region. This novel architecture at the heterojunction opens new material design possibilities and represents an exciting route forward for hybrid photovoltaics.

Dye‐sensitized solar cells (DSSC) are a realistic option for converting light to electrical energy. Hybrid architectures offer a vast materials library for device optimization, including a variety of metal oxides, organic and inorganic sensitizers, molecular, polymeric and electrolytic hole‐transporter materials. In order to further improve the efficiency of solid‐state dye‐sensitized solar cells, recent attention has focused on using light absorbing polymers such as poly(3‐hexylthiophene) (P3HT), to replace the more commonly used “transparent” 2,2′,7,7′‐tetrakis‐(N,N‐di‐p‐methoxyphenyl‐amine)9,9′spiro‐bifluorene (spiro‐OMeTAD), in order to enhance the light absorption within thin films. As is the case with spiro‐OMeTAD based solid‐state DSSC, the P3HT‐based devices improve significantly with the addition of lithium bis(trifluoromethylsulfonyl)imide salts (Li‐TFSI), although the precise role of these additives has not yet been clarified in solid‐state DSCs. Here, we present a thorough study on the effect of Li‐TFSI in P3HT based solid‐state DSSC incorporating an indolene‐based organic sensitizer termed D102. Employing ultrafast transient absorption and cw‐emission spectroscopy together with electronic measurements, we demonstrate a fine tuning of the energetic landscape of the active cell components by the local Coulomb field induced by the ions. This increases the charge transfer nature of the excited state on the dye, significantly accelerating electron injection into the TiO2. We demonstrate that this ionic influence on the excited state energy is the primary reason for enhanced charge generation with the addition of ionic additives. The deepening of the relative position of the TiO2conduction band, which has previously been thought to be the cause for enhanced charge generation in dye sensitized solar cells with the addition of lithium salts, appears to be of minor importance in this system.

The use of photocatalytic titania nanoparticles in the development of self-cleaning and depolluting paints and microbiological surfaces is demonstrated. In the former case surface erosion and sensitised photooxidation is shown to be controlled by the use of catalytic grades of anatase nanoparticles. For environmental applications in the development of coatings and cementitious materials for destroying atmospheric pollutants such as nitrogen oxides (NOX) stable substrates are also illustrated with photocatalytic nanoparticles. Here porosity of the coatings through calcium carbonate doping is shown to be crucial in the control of the effective destruction of atmospheric NOX gases. Good environmental stability of the coatings is also crucial for long term durability and this aspect is examined for a variety of material substrates. For the development of microbiological substrates for the destruction of harmful bacteria/fungi effective nanoparticle anatase titania is shown to be important with hydrated high surface area particles giving the greatest activity. Data from commercial pilot studies is used to signify the important practicalities of this type of new technology.

Here, studies on the evolution of photophysics and device performance with annealing of blends of poly(3‐hexylthiophene) with the two polyfluorene copolymers poly((9,9‐dioctylfluorene)‐2,7‐diyl‐alt‐[4,7‐bis(3‐hexylthien‐5‐yl)‐2,1,3‐benzothiadiazole]‐2′,2′′‐diyl) (F8TBT) and poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) are reported. In blends with F8TBT, P3HT is found to reorganize at low annealing temperatures (100 °C or below), evidenced by a redshift of both absorption and photoluminescence (PL), and by a decrease in PL lifetime. Annealing to 140 °C, however, is found to optimize device performance, accompanied by an increase in PL efficiency and lifetime. Grazing‐incidence small‐angle X‐ray scattering is also performed to study the evolution in film nanomorphology with annealing, with the 140 °C‐annealed film showing enhanced phase separation. It is concluded that reorganization of P3HT alone is not sufficient to optimize device performance but must also be accompanied by a coarsening of the morphology to promote charge separation. The shape of the photocurrent action spectra of P3HT:F8TBT devices is also studied, aided by optical modeling of the absorption spectrum of the blend in a device structure. Changes in the shape of the photocurrent action spectra with annealing are observed, and these are attributed to changes in the relative contribution of each polymer to photocurrent as morphology and polymer conformation evolve. In particular, in as‐spun films from xylene, photocurrent is preferentially generated from ordered P3HT segments attributed to the increased charge separation efficiency in ordered P3HT compared to disordered P3HT. For optimized devices, photocurrent is efficiently generated from both P3HT and F8TBT. In contrast to blends with F8TBT, P3HT is only found to reorganize in blends with F8BT at annealing temperatures of over 200 °C. The low efficiency of the P3HT:F8BT system can then be attributed to poor charge generation and separation efficiencies that result from the failure of P3HT to reorganize.

We investigate photovoltaic devices based on a red-absorbing conjugated polymer poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4‘,7‘-di-2-thienyl-2‘,1‘,3‘-benzothiadiazole)) (APFO-3). We show that the polymer acts as an electron donor when blended with ZnO nanoparticles, giving a short-circuit quantum efficiency of 28%. When blended with poly(3-hexylthiophene) (P3HT), however, the APFO-3 acts as an electron acceptor, giving a short-circuit quantum efficiency of 12%. We study this charge-transfer process by comparing photoinduced absorption spectra of the hybrid blends with the absorption spectra of chemically doped APFO-3, which allows us to distinguish features due to positive and negative polarons. We also present dark current measurements of single-carrier devices which demonstrate that APFO-3 has similar mobilities for electrons and holes, consistent with ambipolar behavior in photovoltaic devices.

Intramolecular charge-transfer fluorescent probes have been used as physical enhancers of chemiluminescence. PET exhibits low chemiluminescence emission; however, in the presence of Coumarin 337, the energy transfer from thermally generated excited carbonyl to ground-state probe molecule takes place, giving rise to the fluorescence emission from coumarin. Employing this method, the chemiluminescence emissions of several poly(ethylene terephthalate)s, initial and annealed at different temperatures, were studied. The observed emission has been proved to be sensitive to the morphology of polymer sample. The CL intensity increased in the temperature range 75−130 °C, and at higher temperature a decrease was detected. It was associated with exothermic recrystallization during heating, which would restrain the peroxyl radicals recombination, which originates the chemiluminescence emission. A lower chemiluminescence emission for annealed samples was observed. It was due to their enhanced crystallinity, which would affect both the mobility of hydroperoxides to recombine themselves and the energy transfer from excited donor to the acceptor fluorescent probe which occurs through a diffusion-controlled process. The CL results correlate with those obtained by means of other techniques also employed in this work:  differential scanning calorimetry, dynamic mechanical analysis, and fluorescence spectroscopy. This result confirms that chemiluminescence emission studies can be used to sense temperature-dependent morphological changes, i.e., annealing processes, and to determine relaxation temperatures and exothermic recrystallization peaks. The use of fluorescent sensor to amplify the chemiluminescence emission allows to apply the innovative method, developed in this work, to all types of polymers, including those with low intensity emission.

The linear logic introduced in [3] by J.-Y. Girard keeps one of the so-called structural rulesof the sequent calculus: the exchange rule. In a one-sided sequent calculus this rule can be formulated asThe exchange rule allows one to disregard the order of the assumptions and the order of the conclusions of a proof, and this means, when the proof corresponds to a logically correct program, to disregard the order in which the inputs and the outputs occur in a program.In the linear logic introduced in [3], the exchange rule allows one to prove the commutativity of the multiplicative connectives, conjunction (?) and disjunction (?). Due to the presence of the exchange rule in linear logic, in the phase semantics for linear logic one starts with a commutative monoid. So, the usual linear logic may be called commutative linear logic.The aim of the investigations underlying this paper was to see, first, what happens when we remove the exchange rule from the sequent calculus for the linear propositional logic at all, and then, how to recover the strength of the exchange rule by means of exponential connectives (in the same way as by means of the exponential connectives ! and ? we recover the strength of the weakening and contraction rules).

AbstractWe study increasing F-sequences, where Fis a dilator: an increasing F-sequence is a sequence (indexed by ordinal numbers) of ordinal numbers, starting with 0 and terminating at the first step xwhere F(x)is reached (at every step x+ 1 we use the same process as in decreasing F-sequences, cf. [2], but with “+ 1” instead of “-1”). By induction on dilators, we shall prove that every increasing F-sequence terminates and moreover we can determine for every dilator Fthe point where the increasing F-sequence terminates.We apply these results to inverse Goodstein sequences, i.e. increasing (1 + Id)(?)-sequences. We show that the theoremevery inverse Goodstein sequence terminates(a combinatorial theorem about ordinal numbers) is not provable in ID1.For a general presentation of the results stated in this paper, see [1].We use notions and results concerning the category ON (ordinal numbers), dilators and bilators, summarized in [2, pp. 25–31].