Surface relief grating recording in azobenzene epoxy films

This work has been supported by National research program IMIS2. I would like to thank Larisa Grigorjeva and Aleksejs Zolotarjovs from Institute of Solid state physics, University of Latvia for FTIR measurements.In this work the direct one step formation of surface relief gratings (SRG) in azo-epoxy polymer films during holographic recording was studied. In this material azo-compound is covalently attached to epoxy forming polymer. The main advantages of azo-epoxy polymers are simple and cheap synthesis, low polymerization degree, thus the photo-induced mass transport process has been facilitated. The dependence of SRG formation efficiency in AAB:BADGE films on sample preparation conditions, film content, recording parameters and possibility of reversible recording and SRG self-enhancement process was studied.National research program IMIS2; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Photo-Induced Mass Transport in Thin Films of Amorphous As2S3

AbstractIn this report direct photo-induced formation of surface relief gratings (SRG) in thin layers of arsenic sulfide (As2S3) are shown. This anisotropic light-induced mass transfer phenomenon has been discussed with the special attention focused on the polarization and intensity of the corresponding light. The experimental setup for the SRG recording is straight-forward consisting of ~10μm optical slit through which an unfocused beam of light is projected on the surface of sample. The evolution of surface relief in dependence from the recording time and polarization has been investigated in detail. The processes of SRG formation and mass transfer which are based on the photo-induced plasticity have discussed

Enhancement of photosensitivity in azo-epoxy resists for direct holographic recording

Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/7 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged”Azo-epoxy resist is promising material for direct holographic recording due to good photosensitivity and possibility to modify structure of molecule during synthesis – obtained polymer polymerization index easily can be changed by varying curing temperature and curing time. Produced photoresist had properties similar to low-weight molecular glasses. In this work 4-Aminoazobenze, Disperse Orange 2 and epoxy resin bisphenol A diglycidyl ether were used. Surface relief grating formation by direct holographic method was performed in obtained resi sts. Surface relief grating post-recording self-enhancement process was investigated. It allows to increase a depth of surface relief grating after holographic recording, using physical method – uniform light illumination. It decreases time and required exposure for recording, making holographic recording more effective because grating formation is less affected by vibrations and noises.ISSP UL Scientific Research Project for Students and Young Researchers No. SJZ/2017/7; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

A Problem of Attrition: The Impact of a Complainant's Mental Health on the Investigation and Prosecution of a Rape Allegation

PhDThis thesis addresses the relevance and impact of a complainant’s mental health on the investigation and prosecution of a rape allegation. There is evidence to suggest that an allegation made by a complainant with a mental health condition is more likely to drop out of the criminal justice process than one without a mental health condition.1 In light of this occurrence, the thesis considers the extent to which there is a connection between the presence of a mental health issue and the likelihood of the allegation being withdrawn – a decision which is made by either by the police, the Crown Prosecution Service or the complainant herself – or discontinued. The thesis examines the relevance and impact of a mental health condition as it arises in key investigative and prosecutorial stages: the initial reporting of the allegation, the complainant’s interview with the police, the process of pre-trial disclosure and the deployment of material relating to the complainant’s mental health at trial. It considers how mental health can influence the assessment of the complainant’s credibility, the quality of the account of the offence, and ability to participate in the judicial process. The thesis finds that mental health is influential in its connection to the attrition of rape cases, with potential ramifications for the complainant, the allegation, and attrition both within and across the key procedural stages. Ultimately, the influence of mental health on the case is cumulative

Luminescence study of detergent optical brighteners in the context of developing optical environmental sensors for water quality control

Water quality and anthropogenic loads in many, but not all, cases are related. Some water quality monitoring programs analyse samples for the presence of Escherichia coli. These bacteria can come from humans and animals. Human‐attributable effluent contains optical brighteners (OBs) from detergents. A convenient and affordable optical quantitative method giving a linear luminescence outcome over several orders of detergent concentrations in the water solution is demonstrated. The proposed method uses the common presence of OBs in detergents. Detergent concentration in water can be used as a surrogate indicator of resultant anthropogenic loads in water bodies. The proposed optical method with linear outcome over several ranges of detergent water concentrations is described. Optinių baliklių skalbimo priemonėse liuminescencijos tyrimas siekiant sukurti optinius aplinkosauginius vandens kokybės kontrolės jutiklius Santrauka Vandens kokybė ir jo antropogeninis turinys daugeliu atvejų, nors ir ne visada, yra susiję. Kai kurios vandens kokybės stebėsenos sistemos analizuoja mėginius ir nustato, ar juose yra Escherichia coli bakterijų. Šios bakterijos gali būti žmogiškosios ir gyvūninės kilmės. Nuotekose, kurios susidaro dėl žmonių veiklos, esti optinių baliklių (OB) iš skalbimo priemonių. Pateiktas patogus ir nebrangiai atsieinantis optinis kvantinis metodas, kurį taikant gaunami tiesiniai liuminescencijos įverčiai, esant skirtingoms skalbimo priemonių koncentracijoms vandenyje. Siūlomas metodas taikomas skalbimo priemonėse naudojant OB. Skalbimo priemonių koncentracijos vandenyje duomenis galima panaudoti kaip pakaitinį vandens telkinių užterštumo rodiklį. Aprašomas optinio metodo taikymas bei tiesiniai įverčiai, gauti tiriant įvairias skalbimo priemonių koncentracijas vandenyje. Reikšminiai žodžiai: vandens kokybė, optiniai aplinkos taršos tyrimai, antropogeninio turinio vandenyje kontrolė ir mažinimas, nuotekų stebėsena, optiniai balikliai, skalbimo priemonės. Исследование концентрации оптических отбеливателей в растворах моющих средств по спектрам люминесценции для контроля качества воды Резюме Качество воды и культурные отложения во многих случаях взаимосвязаны. Иногда при анализе качества воды проводятся исследования на наличие бактерий Escherichia coli, которые могут появляться в отходах, связанных с человеческой жизнедеятельностью, и в отходах животных. Сточные отходы, связанные с жизнедеятельностью человека, содержат оптические отбеливатели из моющих веществ. В настоящей работе описывается практичный и удобный оптический метод для количественной оценки концентрации моющего вещества в водном растворе по линейному выходу люминесценции оптических отбеливателей. Концентрация моющих веществ может быть использована в качестве непрямого индикатора наличия отходов человеческой жизнедеятельности в сточных водах. Ключевые слова: качество воды, оптические измерения загрязнения окружающей среды, мониторинг сточных загрязнений, оптические отбеливатели, флюоресцирующие отбеливающие реагенты, моющие средства, токсикология окружающей среды. Firstd Published Online: 14 Oct 201

Driving Performance while Engaged in MP-3 Player Interaction: Effects of Practice and Task Difficulty on PRT and Eye Movements

The purpose of this study was to examine the effects of iPod interactions on driver performance over several sessions to determine the distraction effect of iPods on driver performance, as well as to see if performance decrements declined with practice. Nineteen younger drivers (mean age = 19.4, range 18 to 22) participated in a seven-session study in the University of Calgary Driving Simulator. Drivers encountered a number of critical events such as pedestrian incursions, lead vehicle braking, and pullout vehicle events, on the roadways. These events were encountered both while driving alone and when performing iPod tasks of varying difficulty. Participants’ hazard response, frequency of collisions and eye movement measures were examined to determine if there were any changes in performance related to iPod distraction and practice effects. Increases in perception response time (PRT) and frequency of collisions were found during the difficult iPod interactions. The number and duration of glances made into the vehicle increased significantly while performing the difficult iPod interactions, reducing the number of glances made to the roadway. Over the course of the sessions, performance improved significantly in all secondary task conditions, but performance decrements still remained in the difficult iPod condition compared to the baseline

Luminescence properties of chlorine molecules in glassy SiO2 and optical fibre waveguides

The support from Latvian Research Program IMIS 2, project “Photonics and materials for photonics” is acknowledged. K.K. was partially supported by the Collaborative Research Project of Materials and Structures Laboratory, Tokyo Institute of Technology. The publication costs of this article were covered by the Estonian Academy of Sciences and the University of Tartu.Glassy SiO2 is the basic material for optical fibre waveguides and manufacturing-induced Cl impurities reduce their transparency in UV spectral range. This work reports in-depth study/spectroscopic parameters of the near-infrared (1.23 eV) low-temperature photo-luminescence (PL) of interstitial Cl2 molecules in SiO2. The zero-phonon line position was estimated at 2.075 eV on the basis of anharmonicity of Cl2 PL vibronic data. The vibronic sub-bands are broadened by coupling to phonons and by an additional contribution from the glassy disorder. The Huang‒Rhys factor is ≈13. The PL decay time is between 1 and 10 ms in the temperature range 100 K‒13 K and can be reproduced by 3 exponents. Cl2 PL retains relatively high quantum yield and its characteristic structured shape, when the temperature is increased from 13 K to the liquid nitrogen temperature. This allows using it conveniently as a high-sensitivity diagnostic tool for detecting Cl2 impurities in optical fibre waveguides. Time-resolved measurements of optical fibre waveguides indicate that the lower detection limit is below 1010 Cl2/cm3.Tokyo Institute of Technology, MSD K.K.,Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²