Energy yield analysis of textured perovskite silicon tandem solar cells and modules.

Perovskite silicon tandem solar cells combine potentially low production costs with the ability to surpass the efficiency limit of silicon single junction solar cells. Optical modeling and optimization are crucial to achieve this ambitious goal in the near future. The optimization should seek to maximize the energy yield based on realistic environmental conditions. This work analyzes the energy yield of perovskite silicon tandem solar cells and modules based on realistic experimental data, with a special focus on the investigation of surface textures at the front and rear side of the solar cell and its implication for reflection as well as parasitic absorption properties. The investigation reveals a 7.3%rel higher energy yield for an encapsulated tandem cell with a textured front side compared with an encapsulated high efficiency single junction solar cell with 24.3% harvesting efficiency for irradiance data of the year 2014 in Freiburg/Germany.

Comparison between periodic and stochastic parabolic light trapping structures for thin-film microcrystalline Silicon solar cells.

Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized by an atomic force microscope. This structure is used for light trapping in thin-film microcrystalline silicon solar cells. Very good agreement is found in a first comparison between simulation and experimental results. The geometrical parameters of the stochastic structure are varied and it is found that the light trapping mainly depends on the aspect ratio (length/height). Furthermore, the maximum possible light trapping with this kind of stochastic structure geometry is investigated. In a second step, the stochastic structure is analysed and typical geometrical features are extracted, which are then arranged in a periodic structure. Investigating the light trapping properties of the periodic structure, we find that it performs very similar to the stochastic structure, in agreement with reports in literature. From the obtained results we conclude that a potential advantage of periodic structures for PV applications will very likely not be found in the absorption enhancement in the solar cell material. However, uniformity and higher definition in production of these structures can lead to potential improvements concerning electrical characteristics and parasitic absorption, e.g. in a back reflector.

Red blood cell storage and cell morphology.

AIM: In this study, we performed weekly assessment of morphology-related parameters through monitoring of CPD-SAGM leuco-filtered erythrocyte concentrates from blood withdrawal until the 42nd day of storage. BACKGROUND: Liquid storage of red blood cells (RBCs) delivers a blood-derived therapeutic, which is safe, available, effective and affordable for most patients who need transfusion therapy in developed countries. However, a growing body of accumulating controversial evidences, from either biochemical or retrospective clinical studies, prompted safety concerns about longer stored RBCs. METHODS: Statistical image analysis through scanning electron microscope was coupled to osmotic fragility and erythrocyte sedimentation rate. RESULTS: We could observe that by day 21 more than 50% of RBCs displayed non-discocyte phenotypes. This observation was related to an increase in osmotic fragility, which was totally overlapped in day 0 controls and day 7 RBCs while only slightly augmented in day 14 samples. Cation dysregulation (pH internal/external alteration and potassium) might both reflect and trigger a negative feedback loop with metabolic fluxes and membrane cation pumps. CONCLUSION: Morphology parameters suggest that significant alterations to RBC morphology over storage duration occur soon after the 14th day of storage, as to become significant enough within the 21st day.

[Risk of accidents to hospital personnel]. / Rischio infortunistico del personale ospedaliero.

The industrial accident phenomenon among personnel on duty in the hospital ambit requires further studies, also for the distinctive aspects that it presents as regards that may be found in the factory. The authors, for this end, have conducted an analysis about industrial accidents happened in the hospitals of Parma in 1977 and in 1978, with reference to the different working qualifications, the sex and the age of the staff, the kind of the suffered lesion, the affected bodily seat and the traumatic event on the occasion of which the injury happened. Moreover distribution per hour of industrial accidents, in relation to shifts as well, their monthly and weekly incidence, compatibly with the difficulties of treatment of the analysis in connection with the heterogeneity, chronological too, of various working services, have been calculated. The above-mentioned survey indicates that the factors that cause a bigger risk of accident are individual factors - sex, age and job - and factors connected both with the kind of internal organization of work and with the structures of working place.

[Clinico-criminological aspects of tattoo removal]. / Aspetti clinico-criminologici in un caso di detatuaggio.

The desire to remove one's tattooes in prison surroundings is unanimously recognized as a positive sign of maturity and rehabilitation. A case of attempted tattoo removal serves to draw attention to some aspects of the motives which underlie such behaviour in order to determine a correct forecast of the real possibilities of the prisoner's recovery. The behavioural and psychological analysis of the case under study confirms the predictive value of the act in that it was coupled with a real request for help on the part of the subject regarding his personal wants and needs. Tattoo removal carried out surgically is concluded to be a useful therapeutic operation with the aim of safeguarding the mental health and rehabilitation of the prisoner.