Low-quality Films Research Articles

Enhanced the thermoelectric power factor of n-type Bi2Te3 thin film via energy filtering effect

In recent years, Bi2Te3 thin films have gained interest in the field of thermoelectric power generation due to their promising thermoelectric performance. However, the poor performance of Bi2Te3 has limited its widespread applicability. To address this, we deposited Bi2Te3 films on soda lime glass substrates via thermal evaporation and annealed them at different temperature ranges between 100 and 350 °C. Our X-ray diffraction analysis showed that the best quality film was produced at a post-annealing temperature of 350 °C, while the as-deposited sample yielded a low-quality film. We then analyzed the surface morphology of the prepared sample using scanning electron microscopy and found that the grains were highly intact with a uniformly aligned granular surface morphology and no porosity. By controlling the density and grain size, we were able to improve the Seebeck coefficient and electrical conductivity. Specifically, the Seebeck coefficient value increased up to 135 μV/°C due to the energy filtering effect at small grain boundaries, while the electrical conductivity improved by raising the charge carrier mobility and reducing grain size, thus increasing the conductivity of the tiny domain. Consequently, the Bi2Te3 thin film with a small grain size exhibited the highest thermoelectric power factor of 15.30 μW cm−1 C−2 at room temperature. Our findings suggest that the thermal evaporation technique is an effective method for growing Bi2Te3 thin films with improved thermoelectric properties.

Специфіка контенту рубрики «Весела сторінка» у журналі «Кіно» за 1928 рік

The article aims to determine the specifics of the content of the «Funny Page» column published in the «Kino» magazine for 1928. Methodology. Descriptive, systematic methods, methods of analysis, synthesis, statistical, and hermeneutic methods were used during the research. Using the descriptive method, the information necessary to cover the topic of the scientific article was recorded. The hermeneutic method made it possible to propose an interpretation of the analyzed texts. Thanks to the statistical method, the frequency of use of creolized texts and texts without creolization in the «Funny Page» section was found. Research results. In the magazine «Kino» for the year 1928, on the sixteenth page, the editors of the publication placed creolized texts (18 – 72 %): poetic sketches (6 – 24 %), illustrated poems (2 – 8 %), illustrated dialogues (3 – 12 %), cartoons (2 blocks in two issues – 8%), cartoons (1 – 4%), caricatures (1+1 block in two issues – 8%), bikt (bipolar creolized text – 1 – 4%), creolized game (1 – 4%). Conclusions. The specificity of the content of the «Funny Page» section in the magazine «Kino» for 1928 is the genre diversity of creolized texts and texts without creolization, the use of illustrations that correlate with the verbal part and sometimes significantly complement it, detailing the psychological states of the main characters, performing a character-building function, expressing extreme situations, reminiscent of the films shown, reveal the outlined problems more deeply. The texts posted in the «Funny Page» section raise the problem of the Soviet cinema screens being filled with militants, their negative impact on the viewer (loss of self-identification, the emergence of suicidal thoughts), the problem of filming a sensation with a risk to life, the script crisis, the problem of the moral degradation of people, in particular mental callousness, due to the pursuit of an interesting frame, the problem of movie mania, the unprofessionalism of film directors, actors, the fleetingness of cinematic fame, the problem of a superficial perception of the object of filming, low-quality film advertising, the problem of a low-quality film product. Keywords: creolized texts, «Kino» magazine, texts without creolization, illustrations, «Funny Page» section.

Tree-Based Ensemble Learning Models for Wall Temperature Predictions in Post-Critical Heat Flux Flow Regimes at Subcooled and Low-Quality Conditions

Abstract Accurately predicting post-critical heat flux (CHF) heat transfer is an important but challenging task in water-cooled reactor design and safety analysis. Although numerous heat transfer correlations have been developed to predict post-CHF heat transfer, these correlations are only applicable to relatively narrow ranges of flow conditions due to the complex physical nature of the post-CHF heat transfer regimes. In this paper, a large quantity of experimental data is collected and summarized from the literature for steady-state subcooled and low-quality film boiling regimes with water as the working fluid in vertical tubular test sections. A low-quality water film boiling (LWFB) database is consolidated with a total of 22,813 experimental data points, which cover a wide flow range of the system pressure from 0.1 to 9.0 MPa, mass flux from 25 to 2750 kg/m2 s, and inlet subcooling from 1 to 70 °C. Two machine learning (ML) models, based on random forest (RF) and gradient boosted decision tree (GBDT), are trained and validated to predict wall temperatures in post-CHF flow regimes. The trained ML models demonstrate significantly improved accuracies compared to conventional empirical correlations. To further evaluate the performance of these two ML models from a statistical perspective, three criteria are investigated and three metrics are calculated to quantitatively assess the accuracy of these two ML models. For the full LWFB database, the root-mean-square errors between the measured and predicted wall temperatures by the GBDT and RF models are 5.7% and 6.2%, respectively, confirming the accuracy of the two ML models.

Investigation of structural and electrical properties of ITO thin films and correlation to optical parameters extracted using novel method based on PSO algorithm

Thermally annealed DC sputtered indium tin oxide (ITO) thin films were investigated for improvement in properties. The structural and optoelectronic characteristics of as-grown and air annealed films were studied and correlated to the film deposition time. Raman spectroscopy analysis showed low crystalline quality films for as-grown films and were significantly improved after annealing. X-ray diffraction analysis confirmed the crystallinity of samples with (222) preferential orientation. The 30-min ITO films showed a peak at (400). The films optical study shows an increased transmittance (in the transparency region) with decreasing deposition time, yielding a high transparency of 90% for the 5- and 15-min ITO films annealed at 400°C. The films thickness and optical constants were determined from optical transmission only without interference fringe using a novel method based on particle swarm optimization (PSO) algorithm. The absorption coefficient and calculated refractive index decreased with increasing deposition time and their value reduced further after annealing treatment. The 30-min ITO films showed a comparable low resistivity of 4 × 10−3 Ω cm before and after annealing as determined by Hall effect measurements. This observation confirms their non-sensitivity to the oxygen post-contamination that resulted from (400) orientation. A shift of the absorption edge towards shorter wavelengths accompanied with an increase in the optical bandgap before and after annealing with decreasing thickness were observed. We have demonstrated that the optical parameters such as the optical gap depend mainly on the electrical parameters such as the carrier concentration.

Machine learning with knowledge constraints for process optimization of open-air perovskite solar cell manufacturing

Machine learning with knowledge constraints for process optimization of open-air perovskite solar cell manufacturing

Facile tuning of PbI2 porosity via additive engineering for humid air processable perovskite solar cells

Fabrication of perovskite solar cells (PSC) in ambient environment or high relative humidity (RH) condition may assist in reducing the production cost and simplifying the fabrication process. However, processing PSC in high-humidity faces major challenges related to degradation of perovskite material and formation of low-quality film. To this end, we focus on improving the perovskite film quality by introducing 4-tert-butylpyridine (TBP) as additive to manipulate the morphology of PbI2 for fabricating efficient PSC in ambient air with RH30–40%. The amount of TBP is varied between 0 and 15 vol%. It is found that increasing the amount of TBP gradually transforms the compact PbI2 layer to porous structure. This allows methylammonium iodide solution to penetrate deep into the layer even after volume expansion of perovskite crystals. As a result, high-quality perovskite layer with low defect and appropriate amount of PbI2 phase passivation layer is produced. Such feature enhances the light absorption, improves the charge separation and reduces the charge recombination. By increasing the TBP content to 10 vol%, a best efficiency of 15.1% has been acquired and the device also exhibits better ambient stability. The additive engineering approach developed in this work may offer a new insight for the development of efficient and stable PSC under humid atmosphere.

Fabrication of flexible electrochromic film based on amorphous isopolytungstate by low-temperature inkjet-printed process with a solution crystallization kinetic-controlled strategy

Polyoxometalate (POM) is a promising functional material in the area of electrochromic device due to its good solution processable characteristic, but the low-quality film formation limits its application. Here, a crystallization kinetic-controlled strategy is suggested to form the amorphous isopolytungstate (IPT) film. By controlling the solution alkalinity, metatungstate clusters are dissociated into tiny tungstate monomers, inhibiting spontaneous crystallization nucleation and crystal growth. The amorphous IPT film is prepared using inkjet print technology with a series of low-temperature process (<70 °C), and it shows crack-free and smooth morphology, which results in a lower haze than crystalline IPT film. The electrochromic optical modulation ability of IPT film is enhanced from 14.8% to 46.2% after amorphous transformation. The coloring and bleaching response time of IPT film reaches 2.8 s and 10.4 s, respectively. The cyclic voltammetry test demonstrates that amorphous IPT film owns more excellent cyclic voltammetry stability (1800 cycles without capacity degradation) than crystalline IPT film (200 cycles with > 93% capacity degradation), which is attributed to its high-quality film structure. Additionally, the amorphous IPT film also shows more excellent flexibility than crystal IPT film due to eliminating the rigid lattice structure of salt crystal. The flexible IPT electrochromic device can maintain electrochromic modulation well after 1000 times bending with a radius of 10 mm, which is attributed to the excellent flexibility of amorphous IPT film.

Study on interfacial friction in the inverted annular film boiling regime

The interfacial friction factor is an important closure model in the two-fluid model for the inverted annular film boiling (IAFB) regime. Almost all the interfacial friction factor correlations used in IAFB modeling were obtained based on experimental data from annular two-phase flows. This paper first reviews the interfacial friction factor models/correlations used in IAFB modeling. A laminar vapor film model is then derived for the smooth IAFB region based on a laminar flow assumption. Experimental data obtained from subcooled and low-quality film boiling experiments in the literature are reduced to calculate the interfacial friction factor by solving one-dimensional two-fluid momentum equations for the liquid and vapor phases. The trend of the interfacial friction factor indicates that the transition from the smooth to wavy IAFB regions occurs at a void fraction range of 0.2 to 0.4. Comparisons between the laminar vapor film model and corresponding experimental data and nine correlations in the literature indicate that the laminar vapor film model appears to provide the lower bound of the interfacial friction factor in the smooth IAFB region. Two interfacial friction factor correlations from the literature are recommended for the smooth and wavy IAFB regions based on the analysis. It can be concluded that the interfacial friction factor in the smooth IAFB region is dependent on the gas Reynolds number and vapor film thickness, while in the wavy IAFB region, it is primarily dependent on the amplitude of the interfacial waves.

Investigating the level of Safety Considerations in Radiology Centers (North of Iran): Cross –Sectional Study

Background and Purpose Providing health care is the basic right of people(1). Diagnostic radiology is one of the main procedures in health care services and proper benefiting from this technology is brought only under well planning and management(1). Supervision of the available condition and its comparison with the recommended standards is a key role in assessing assurance from the benefit of these instruments (2). Data show that more than 80% of patients referring to these hospitals need radiology image (3).Improper service causes repetition of radiography and even wrong diagnosis, as a results threatening health of the patients (3) lack of protective barrier leads to the exposure of the staff to X-ray which is obviously carcinogen us (4). It happens that the instruments are not working properly, like of symmetry in X-ray field, defects in collimators, lack of adjusting ray field and X-ray, low quality or defective developing machine, lack of proper protective barrier, using low quality film and drugs, lack of protective barrier for children, all of which cause severe hazards for the patients and staff (4). Materials and Methods The crucial aim of medical services is to provide the public with their needs which are very important. The sensitivity of such services is to such an extent that in case of lack of care, the hazards are too high. In evaluation of health services, the first thing is to evaluate the device used. Methods, efficiency, profits and their combination for prevention and eradication of diseases are also important. Therefore to gain this goal, it is necessary the obtain results comparable with recommended standards. The purpose of this study was to access the conditions of radiology units at Mazandaran University hospitals and compare them with the standards of ICRU NCRP and ICRP. Radiology unit is the most expensive section of any hospital for its instruments, manpower and space provided. In a study conducted in 51centers on radiology staff, radiography room and protective barrier, ray leakage, the outcome were 89%, 82%, 77% and 37% respectively. It was found that the condition of these centers regarding the protective barriers is very unsuitable due to unawareness of the leakage (5, 6).Considering the mentioned necessities, in this study, the condition of radiography centers affiliated to the Mazandaran University of Medical Sciences was studied for the type and the rate of problem, in order to provide a proper solving method. Results Data were collected through, observation, interviewing and filling questionnaire. Results show that, the situations of the radiology units are for from international standard, to such an extent that it is matched clout 50%. Conclusion The results showed that, none of the dark rooms are standard, and do not have proper alarm signal. In 63% of these units there no tiling system about staff protection from radiation. Defects in radiography room, protective barrier and lack looking rays were 60%, 51% and 47% respectively. Referring to the obtained data, periodic supervision, and obeying of the standards are necessary.

Printable CsPbI3 Perovskite Solar Cells with PCE of 19% via an Additive Strategy.

All-inorganic CsPbI3 holds promise for efficient tandem solar cells, but reported fabrication techniques are not transferrable to scalable manufacturing methods. Herein, printable CsPbI3 solar cells are reported, in which the charge transporting layers and photoactive layer are deposited by fast blade-coating at a low temperature (≤100 °C)in ambient conditions. High-quality CsPbI3 films are grown via introducing a low concentration of the multifunctional molecular additive Zn(C6 F5 )2 , which reconciles the conflict between air-flow-assisted fast drying and low-quality film including energy misalignment and trap formation. Material analysis reveals a preferential accumulation of the additive close to the perovskite/SnO2 interface and strong chemisorption on the perovskite surface, which leads to the formation of energy gradients and suppressed trap formation within the perovskite film, as well as a 150 meV improvement of the energetic alignment at the perovskite/SnO2 interface. The combined benefits translate into significant enhancement of the power conversion efficiency to 19% for printable solar cells. The devices without encapsulation degrade only by ≈2% after 700 h in air conditions.

Pulsed laser deposition of antimony selenosulfide thin film for efficient solar cells

Antimony selenosulfide, Sb2(SxSe1−x)3, has been considered as a promising light harvesting material for low-cost, non-toxic, and stable solar cell applications. However, current preparation methods of Sb2(SxSe1−x)3 suffer from low-quality films, which hampers the performance improvement in Sb2(SxSe1−x)3-based solar cells. Herein, we develop a pulsed laser deposition technique to fabricate antimony selenosulfide films with flat and compact surface morphology and high crystallinity. The composition of the as-obtained films can be conveniently tuned via varying molar ratios of Sb2S3 and Se in targets. At optimized conditions, we fabricate planar heterojunction solar cells and then obtain a significantly improved power conversion efficiency of 7.05%. Our research offers a facile and robust preparation method for Sb2(SxSe1−x)3 films with enhanced photovoltaic properties.

Almost Famous: How Wealth Shocks Impact Career Choices

Using a novel data set of career histories in the film industry, we study the effect of housing wealth shocks on the quality of jobs that individuals pursue. Homeowners facing greater declines in local house price reduce their participation in high-quality projects, such as big-budget films and productions with award-winning talent, while increasing their involvement in low-quality films. Importantly, renters are not affected by these shocks. Consistent with individuals using home equity during job searches, these negative shocks have a greater impact on lower-equity and less-wealthy homeowners. Moreover, house price declines from the housing crisis also affect long-term career outcomes.

Thermal hydraulic performance analysis of a post-CHF heat transfer test facility

Post critical heat flux (post-CHF) heat transfer may occur in loss of coolant accidents (LOCAs) in water-cooled nuclear reactors when makeup water quenches the uncovered fuel rods in the reactor core. The post-CHF regimes are characterized by low heat transfer coefficient and high wall temperature due to the vapor-wall contact. A good understanding of the hydrodynamics and heat transfer process in the post-CHF regimes, especially low-quality film boiling, such as inverted annular film boiling (IAFB) and inverted slug film boiling (ISFB), is imperative for accurately modeling the post-CHF phenomena and predicting the fuel rod cladding temperature and void fraction during accidents. This paper first discusses limitations of existing post-CHF hydrodynamics and heat transfer models/correlations and then identifies needs of post-CHF experimental data under high-flow and high-pressure conditions for model improvement. To narrow down the gap in the available experimental data, a Post-CHF Heat Transfer (PCHT) test facility is designed to perform quasi-steady-state low-quality film boiling experiments under high-pressure (ranging from 0.14 to 3.45 MPa), high-flow (ranging from 150 to 2000 kg/m2-s), and high inlet subcooling (up to 50 °C) conditions. In addition to the experimental study, a numerical model using COMSOL Multiphysics tool is developed to inform the test section design and to investigate wall heat flux and wall temperature distributions in the post-CHF regimes. The COMSOL Multiphysics simulation results show that quasi-steady-state post-CHF phenomena can be achieved in the PCHT test section. Considering thermal non-equilibrium conditions in the post-CHF regimes, a one-dimensional two-fluid model is implemented into a computer code to predict the void fraction using the wall temperature information obtained from the COMSOL simulation results. A correlation for the liquid-side Nusselt number is obtained for the IAFB regime based on previous experimental data and is implemented into the code, which results in an improvement in the agreement between the calculated void fraction and corresponding experimental data. With the new Nusselt number correlation, a parametric study of the effects of the heat flux, pressure, mass flux, and inlet subcooling on the liquid-side Nusselt number is studied. In addition, flow regime transition in the post-CHF regimes is studied by comparing the existing correlation and experimental data. Furthermore, the Weber number and liquid-side Nusselt number are calculated to examine whether there exists any correlation between these two non-dimensional numbers and the flow regime transition. The simulation results provide insights for design improvement of the PCHT test section and assist the development of a test plan for future IAFB and ISFB tests under high-pressure, high-flow, and high-subcooling conditions in the PCHT test facility.

Vapor transport deposition of antimony selenide thin film solar cells with 7.6% efficiency

Antimony selenide is an emerging promising thin film photovoltaic material thanks to its binary composition, suitable bandgap, high absorption coefficient, inert grain boundaries and earth-abundant constituents. However, current devices produced from rapid thermal evaporation strategy suffer from low-quality film and unsatisfactory performance. Herein, we develop a vapor transport deposition technique to fabricate antimony selenide films, a technique that enables continuous and low-cost manufacturing of cadmium telluride solar cells. We improve the crystallinity of antimony selenide films and then successfully produce superstrate cadmium sulfide/antimony selenide solar cells with a certified power conversion efficiency of 7.6%, a net 2% improvement over previous 5.6% record of the same device configuration. We analyze the deep defects in antimony selenide solar cells, and find that the density of the dominant deep defects is reduced by one order of magnitude using vapor transport deposition process.

Physical and electrical characteristics of NiFe thin films using ultrasonic assisted pulse electrodeposition

Nickel iron (NiFe) thin films were prepared on the copper substrate by ultrasonic assisted pulse electrodeposition under galvanostatic mode. Careful control of the thin films deposition is essential as the electrical properties of the films could be greatly affected, particularly if low quality films are produced. The preparation of NiFe/Cu thin films was aimed to reduce the grain size of NiFe particles, surface roughness and electrical resistivity of the copper substrates. Various parameters were systematically studied including current magnitude, deposition time and ultrasonic bath temperature. The optimized conditions to obtain NiFe permalloy, which subsequently applied to all investigated samples, were found at a current magnitude of 70mA deposited for a duration of 2min under ultrasonic bath temperature of 27°C. The composition of NiFe permalloy was as close as Ni 80.71% and Fe 19.29% and the surface roughness was reduced from 12.76nm to 2.25nm. The films electrical resistivity was decreased nearly sevenfold from an initial value of 67.32μΩcm to 9.46μΩcm.

Weakly supervised motion segmentation with particle matching

Motion segmentation refers to the task of segmenting moving objects subject to their motion in order to distinguish and track them in a video. This is a challenging task in situations where different objects share similar movement patterns, or in cases where one object is occluded by others in part of the scene. In such cases, unsupervised motion segmentation fails and additional information is needed to boost the performance. Based on a formulation of the clustering task as an optimization problem using a multi-labeled Markov Random Field, we develop a semi-supervised motion segmentation algorithm by setting up a framework for incorporating prior knowledge into the segmentation algorithm. Prior knowledge is given in the form of manually labelling trajectories that belong to the various objects in one or more frames of the video. Clearly, one wishes to limit the amount of manual labelling in order for the algorithm to be as autonomous as possible. Towards that end, we propose a particle matching procedure that extends the prior knowledge by automatically matching particles in frames over which fast motion or occlusion occur. The performance of the proposed method is studied through a variety of experiments on videos involving fast and complicated motion, occlusion and re-appearance, and low quality film. The qualitative and quantitative results confirm reliable performance on the types of applications our method is designed for.

Inside view

Gallium arsenide finds use in a great number of electronics applications, and one of these is antireflection components in optoelectronic devices. Professor Douglas Hall of the University Of Notre Dame in the US tells us a bit more about his group's latest work in this field. Yuan Tian, Jinyang Li, and Doug Hall outside the Notre Dame Nanofabrication Facility, where the processing and some of the characterisation work was performed Gallium arsenide (GaAs) is widely used for optoelectronic devices such as photodetectors, solar cells, and red through amber LEDs. Uncoated GaAs has a reflectance of ∼33-47% across the visible spectrum. All of these devices can benefit from an antireflection layer on the surface to improve light collection or extraction efficiency. Many researchers (dating back to Henry Minden at General Electric in 1962) have tried a wide variety of methods to form a useful, insulating dielectric layer on the III-V compound semiconductor GaAs, akin to silicon dioxide grown on silicon. However, similar thermal oxidation processes do not readily work for GaAs because the material decomposes (i.e., Ga and As atoms “dissociate”) at the temperatures over 800°C typically used with silicon. We have recently discovered a means to directly oxidise GaAs at the relatively low temperature of 420°C. In this Letter, we show that the GaAs oxide films formed have a suitable refractive index and sufficiently smooth interfaces to form a useful antireflection (AR) layer on GaAs. The thermal oxidation methods previously reported for GaAs have typically used temperatures in the 510-700°C range and often resulted in low quality films with poor adhesion and rough surfaces and interfaces due to extensive pitting caused by dissociation. Most prior work doesn't report surface or interface roughness for these reasons. To form a high-performance AR layer based on thin-film interference effects, very smooth top and bottom oxide interfaces are absolutely essential so that two highly specular reflections are able to interfere destructively (when a relative phase shift of 180° is obtained for a given thickness and refractive index). In addition to our reported atomic force microscopy measurements of roughness, the close match between modelled and measured reflectance for the GaAs oxide AR layers realised in this work demonstrates the excellent interface quality of the oxides obtained through our process. When conventional wet-thermal oxidation of aluminum gallium arsenide (AlGaAs) was discovered by John Dallesasse et al. at the University of Illinois in 1990, it was found to be widely applicable only to alloys containing higher Al/Ga ratios, given the much greater chemical reactivity of Al. Around 2001, we found that oxidation rates of lower Al content alloys could be significantly enhanced (an order of magnitude or more) by mixing dilute amounts of oxygen into the water vapor process gas. In subsequent studies, we have learned that even Al-free alloys like GaAs and InGaAs can be oxidised, but the gas mixture must be carefully optimised and precisely controlled within a quite narrow “sweet spot”, a range of ∼0.1-0.2% oxygen flow rates relative to our nitrogen carrier gas. If too high or too low, or if small amounts of air leak into the system, surface quality and uniformity degrade, or no oxide grows at all. Even in 1962, Minden mixed water vapor with oxygen in the first reported study on GaAs oxidation, but concluded that it had no effect for temperatures under 800°C! This indicates that finding the proper O2/H2O ratio is critically important, and not just any mixture of these gases will do. We have elucidated the “why and how” details of the chemistry involved in some of our group's earlier papers on this subject. Optical microscope image of three oxidised GaAs samples on top of an unoxidised GaAs wafer We have recently been working to further enhance several aspects of the process control in our III-V compound semiconductor oxidation furnace, especially to more precisely regulate and monitor the optimal mixed gas ratios. Our wider research interests include applications of these native oxides to improve optical waveguides for semiconductor lasers and photonic integration, and we are currently actively exploring the extension of our process to telecommunications-wavelength InP-based materials and devices. As much as oxides of high-Al content alloys have found very widespread use for current apertures in commercial vertical cavity surface emitting lasers over the past 10-20 years, we would like to see the enhanced performance of other optoelectronic and photonic devices through the incorporation of oxidised low-Al content, Al-free, and InP-based alloys enabled by the mixed-gas oxidation process demonstrated in this work.

Layer by layer H-bonded assembly of P4VP with various hydroxylated PPFS: impact of the donor strength on growth mechanism and surface features.

Hydrogen bond mediated films made by step by step deposition of poly(4-vinylpyridine) (P4VP) and hydroxylated poly(2,3,4,5,6-pentafluorostyrene) (PPFS) copolymers prepared by thiol para-fluoro coupling, bearing either one (PPFSME) or two (PPFSMPD) hydrogenated hydroxyl groups or a (poly)fluorinated hydroxyl (PPFSOH), respectively, were successfully constructed. The influence of the structural parameters, such as the hydroxyl environment (which dictates the H-bond strength) was in-depth investigated in terms of their impact on (i) growth mechanism, (ii) internal organization, and (iii) surface features. The use of the weaker H-bond donor partner (PPFSME) leads to low quality films composed of irregularly distributed aggregates. While [PPFSMPD/P4VP] multilayer films are comparatively thick and composed of stratified layers with smooth topology, the use of PPFSOH with P4VP yields thin films made of mixed and interpenetrated polymer layers. Playing on the interaction strength appears as a powerful tool to elaborate tailored multilayer films with molecularly tunable properties.

Semi-Legibility and Visual Evidence: An Initial Exploration

This essay names and examines an often-used but little discussed category of legal evidence: semi-legible visual evidence. Semi-legible visual evidence can take many forms, including blurry photographs; low-quality films shot by police dashboard cameras, surveillance cameras, or iphones; fingerprints; x-rays; MRIs and PET scans, to name just a few of the many types of visual display introduced in court that are only partly decipherable to a (lay) viewer. Semi-legible images cannot be said simply to speak for themselves; they must be made to speak, through the exertion of effort, expertise, or both. I argue that thinking about these different kinds of visual evidence together has the effect, not only of highlighting semi-legibility as a meaningful evidentiary category, but also of suggesting important but often-unnoticed connections between expertise and visual legibility. In addition, this essay offers a basic taxonomy of semi-legible visual evidence, examining, in turn, blurry images; interpretively ambiguous images; ‘jigsaw’ images, in which an important piece is missing; images semi-legible to laypeople but readily decipherable by those with relevant expertise; and images semi-legible even to experts. For each category, I describe its parameters, focus on strategies by which it may be made more (or less) legible, and discuss particular challenges it offers as evidence. This essay thus aims to contribute to our understanding of the complex methods by which we produce, wield, enhance, read and interpret visual evidence in court.

Management Insights

Management Insights