Nuorten johtajien johtamiskäytänteet asiantuntijaorganisaatioissa

Johtajasukupolvet ovat vaihtumassa ja tulevaisuudessa tarvitaan yhä useampia nuoria johtajia täyttämään johtajien paikkoja. Tämä tutkimus osallistuu nuorista johtajista ja tällä hetkellä työelämässä olevasta nuorimmasta sukupolvesta käytävään tieteelliseen ja yhteiskunnalliseen keskusteluun. Tutkimuksen tavoitteena on kuvata ja ymmärtää nuorten johtajien johtamiskäytänteitä asiantuntijaorganisaatioissa. Tutkimuksen on luonteeltaan kvalitatiivinen ja sen pääasiallinen aineisto koostuu kymmenen nuoren johtajan haastatteluista. Tutkimuksen mukaan nuoret johtajat ovat eettisiä ja autenttisia johtajia, jotka arvostavat johtamisessaan yhä enemmän niin sanottuja pehmeitä arvoja, kuten oikeudenmukaisuutta, avoimuutta, ihmisten kehittämistä, kuuntelutaitoa ja muiden huomioon ottamista sekä kykyä inspiroida. Nuoren johtajan tapa johtaa on valmentavaa ja esimerkillä johtamista, joka perustuu ennen kaikkea valtuuttamiselle ja yhteistyölle alaisten kanssa.

Potential of biogas production from swine manure supplemented with glycerine waste

In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

Alueellinen energiatasemalli

Kiinnostus energia-asioiden käsittelemiseen alueellisesti yksittäisen rakennuksen asioiden käsittelyn sijaan on lisääntynyt voimakkaasti viime vuosina. Keskustelu alueellisesta ener-gia-asioista on kuitenkin vasta alussa ja alueellisiin energiatarkasteluihin tarvitaan työväli-neitä. Tämän työn päätavoitteena oli luoda alueellinen energiatasemalli, jolla voidaan laskea alueen rakennuskannan energiankulutusta ja -tuotantoa sekä energiantuotannon hiilidi-oksidipäästöjä helposti ja nopeasti. Työssä perehdyttiin alueellisten energiatarkasteluiden tämän hetken tasoon, työvälineisiin ja ohjeistukseen. Myös Suomen rakentamismääräyskokoelman rakennusten energiatehok-kuusmääräyksiin tutustuttiin. Alueellisen energiatasemallin perustana käytettiin uusien rakentamismääräysten E-lukulaskennan ohjeistusta. Mallin toimivuutta testattiin Helsingin Salmenkallioon rakennettavaan uudisrakennusalueeseen. Testattaessa mallilla laskettiin kyseisen alueen energiankulutus sekä erilaisia energiantuo-tantovaihtoehtoja ja todettiin, että erityisesti energiankulutuksen laskenta on hyvin helppoa, kun alueen rakennusten kerrosalat ovat tiedossa. Tuotantopuolen uusiutuvan energian laskeminen luotettavasti vaatii hiukan enemmän taustatyötä, mutta varsinainen mallin käyt-täminen on helppoa ja tulokset saadaan suoraan selkeinä kuvaajina. Työssä onnistuttiin luomaan tavoitteiden mukainen malli, jota voidaan soveltaa erilaisissa alueellisissa energiatarkasteluissa. Tarkasteltaessa energia-asioita alueellisesti, saadaan esimerkiksi alueen huipputehon tarvetta pienennettyä ja energiantuotantoa optimoitua. Malli ei kuitenkaan ole vielä valmis laskentatyökalu, vaan vaatii jatkokehitystä, mikäli sitä halutaan hyödyntää laajemmin.

Pk-yritysten ja korkeakoulujen (teknologia) T&K&I yhteistyön kehittäminen teollisuuden toimialoilla

The aim of this work is to develop entrepreneurship in university technology side. The means of SMEs is made in collaboration with the research development and innovation projects. At the same time supporting and enabling the growth of SMEs, the internationalization of higher education and increase student’s employability in SMEs. The aim is to create new startup companies with the help of co-operation both SMEs and universities, especially assist companies find the successor generation of change by improving interaction between the parties. The new growth oriented entrepreneurial business creation with help of SMEs will be seen more business supporting and opening more opportunities. Portfolio Entrepreneurship is a form of the company’s growth, even the size of company does not change so much. Portfolio Entrepreneurship is an alternative for entrepreneurs which do have possibilities to expand, but they do like keep it as family business. Variety can be seen in expansion if the SMEs have common interest to do so. Co-made projects, between SMEs and universities, are seen to be significantly affecting the wellbeing of society as a whole, and eve international level. Co-operation is considered to be also affected the quality of learning and teachers’ professional development. higher education supports the change of the supports to innovation when it is done with SMEs. Research material has been collected by interviewing the experts, who have already distinguished themselves in their field. Problem focused interviews as method gave the ways how the university students and SMEs can proceed and promote on industrial sector.

Developing Service-based Solutions for Water Treatment in Finnish Mining Industry

The aim of this master’s thesis is to analyze the mining industry customers' current and future needs for the water treatment services and discover new business development opportunities in the context of mine water treatment. In addition, the study focuses on specifying service offerings needed and evaluate suitable revenue generation models for them. The main research question of the study is: What kind of service needs related to water treatment can be identified in the Finnish mining industry? The literature examined in the study focused on industrial service classification and new service development process as well as the revenue generation of services. A qualitative research approach employing a case study method was chosen for the study. The present study uses customer and expert interviews as primary data source, complemented by archival data. The primary data was gathered by organizing total of 13 interviews, and the interviews were analyzed by using qualitative content analysis. The abductive-logic was chosen as the way of conducting scientific reasoning in this study. As a result, new service proposals were developed for Finnish mine industry suppliers. The main areas of development were on asset efficiency services and process support services. The service needs were strongly associated with suppliers’ know-how of water treatment process optimization, cost-effectiveness as well as on alternative technologies. The study provides an insight for managers that wish to pursue a water treatment services as a part of their business offering.

Research and development of III-V semiconductor surfaces for improved device interfaces

This thesis is devoted to understanding and improving technologically important III-V compound semiconductor (e.g. GaAs, InAs, and InSb) surfaces and interfaces for devices. The surfaces and interfaces of crystalline III-V materials have a crucial role in the operation of field-effect-transistors (FET) and highefficiency solar-cells, for instance. However, the surfaces are also the most defective part of the semiconductor material and it is essential to decrease the amount of harmful surface or interface defects for the next-generation III-V semiconductor device applications. Any improvement in the crystal ordering at the semiconductor surface reduces the amount of defects and increases the material homogeneity. This is becoming more and more important when the semiconductor device structures decrease to atomic-scale dimensions. Toward that target, the effects of different adsorbates (i.e., Sn, In, and O) on the III-V surface structures and properties have been investigated in this work. Furthermore, novel thin-films have been synthesized, which show beneficial properties regarding the passivation of the reactive III-V surfaces. The work comprises ultra-high-vacuum (UHV) environment for the controlled fabrication of atomically ordered III-V(100) surfaces. The surface sensitive experimental methods [low energy electron diffraction (LEED), scanning tunneling microscopy/spectroscopy (STM/STS), and synchrotron radiation photoelectron spectroscopy (SRPES)] and computational density-functionaltheory (DFT) calculations are utilized for elucidating the atomic and electronic properties of the crucial III-V surfaces. The basic research results are also transferred to actual device tests by fabricating metal-oxide-semiconductor capacitors and utilizing the interface sensitive measurement techniques [capacitance voltage (CV) profiling, and photoluminescence (PL) spectroscopy] for the characterization. This part of the thesis includes the instrumentation of home-made UHV-compatible atomic-layer-deposition (ALD) reactor for growing good quality insulator layers. The results of this thesis elucidate the atomic structures of technologically promising Sn- and In-stabilized III-V compound semiconductor surfaces. It is shown that the Sn adsorbate induces an atomic structure with (1×2)/(1×4) surface symmetry which is characterized by Sn-group III dimers. Furthermore, the stability of peculiar ζa structure is demonstrated for the GaAs(100)-In surface. The beneficial effects of these surface structures regarding the crucial III-V oxide interface are demonstrated. Namely, it is found that it is possible to passivate the III-V surface by a careful atomic-scale engineering of the III-V surface prior to the gate-dielectric deposition. The thin (1×2)/(1×4)-Sn layer is found to catalyze the removal of harmful amorphous III-V oxides. Also, novel crystalline III-V-oxide structures are synthesized and it is shown that these structures improve the device characteristics. The finding of crystalline oxide structures is exploited by solving the atomic structure of InSb(100)(1×2) and elucidating the electronic structure of oxidized InSb(100) for the first time.

Readout Electronics for Gas Electron Multiplier Detectors

The European Organization for Nuclear Research (CERN) operates the largest particle collider in the world. This particle collider is called the Large Hadron Collider (LHC) and it will undergo a maintenance break sometime in 2017 or 2018. During the break, the particle detectors, which operate around the particle collider, will be serviced and upgraded. Following the improvement in performance of the particle collider, the requirements for the detector electronics will be more demanding. In particular, the high amount of radiation during the operation of the particle collider sets requirements for the electronics that are uncommon in commercial electronics. Electronics that are built to function in the challenging environment of the collider have been designed at CERN. In order to meet the future challenges of data transmission, a GigaBit Transceiver data transmission module and an E-Link data bus have been developed. The next generation of readout electronics is designed to benefit from these technologies. However, the current readout electronics chips are not compatible with these technologies. As a result, in addition to new Gas Electron Multiplier (GEM) detectors and other technology, a new compatible chip is developed to function within the GEMs for the Compact Muon Solenoid (CMS) project. In this thesis, the objective was to study a data transmission interface that will be located on the readout chip between the E-Link bus and the control logic of the chip. The function of the module is to handle data transmission between the chip and the E-Link. In the study, a model of the interface was implemented with the Verilog hardware description language. This process was simulated by using chip design software by Cadence. State machines and operating principles with alternative possibilities for implementation are introduced in the E-Link interface design procedure. The functionality of the designed logic is demonstrated in simulation results, in which the implemented model is proven to be suitable for its task. Finally, suggestions that should be considered for improving the design have been presented.

Metsäteollisuuden ympäristöstrategia hallinnon näkökulmasta : Metsäteollisuuden kehitysskenaariot vuoteen 2020

Suomen metsäteollisuus elää voimakasta uusiutumis- ja murrosvaihetta, joka ilmenee muutoksina yksittäisten tehtaiden ja tehdasintegraattien toiminnassa. Monia yksikköjä on poistunut tuotannosta ja tuotannon painotusta on muutettu. Toisaalta metsäteollisuus on suuntaamassa uusille aloille, jolloin tuotteina voivat olla esimerkiksi erilaiset biopolttoaineet, kemianteollisuuden raaka-aineet ja uuden sukupolven paperi- ja kartonkituotteet. Metsäteollisuuden muuttuminen ja laitosten monimutkaistuminen sekä jatkuvasti lisääntyvä tiedontarve asettavat yhä suurempia vaatimuksia sekä toiminnanharjoittajien ympäristövastaaville että viranomaisille. Hallinnon jatkuva muutos ja niukkenevat voimavarat voivat johtaa siihen, että käytännön lupa- ja valvontatyöhön jää yhä vähemmän aikaa. Kaakkois-Suomen ELY-keskuksen koordinoima hanke ”Metsäteollisuuden ympäristöstrategia vuoteen 2020 – hallinnon näkökulma” pyrkii vastaamaan edellä mainittuihin haasteisiin strategiatyön avulla. Hankkeen tarkoituksena oli tarkastella metsäteollisuuden ympäristönäkökohtia niistä lähtökohdista, joihin yritys voi vaikuttaa raaka-aineen tulosta tehtaalle ja tuotteen lähdöstä tehtaalta sekä tehtaan perustamisesta sulkemiseen ja jälkihoitoon asti. Tavoitteena oli määritellä toiminnoille toimiva ympäristöstrategia. Strategiassa pyrittiin löytämään yhteisymmärrys toiminnanharjoittajan ja viranomaisen kanssa mm. siitä, miten otetaan käyttöön parhaat käytännöt niin teollisuudessa kuin hallinnossakin, toimitaan uusien BAT-, IED- ja vesienhoitoperiaatteiden mukaisesti sekä edistetään kestävän kehityksen mukaisten tuotteiden markkinoille tuloa ja otetaan ennakointi tavaksi -lähtökohta käyttöön kaikessa toiminnassa. Hanketyössä esille nousseet haasteet ryhmiteltiin aihealueittain kolmeksi pääkohdaksi tärkeysjärjestyksessä: viranomaisen ja teollisuuden tiedonkulun ja tietämyksen parantaminen, lupa-, valvonta- ja hallintoprosessien parantaminen sekä uusien haasteiden kartoittaminen ja niihin reagointi. Haasteiden ratkaisukeinoiksi etsittiin käytännön toimenpiteitä sekä määriteltiin niille vastuutahot. Toimenpiteiksi esitettiin mm. viranomaisen ja teollisuuden yhteisiä koulutuspäiviä, asiantuntijapaneelin perustamista sekä lupamääräysten antamista myös tehtaan tai tuotantoyksikön sulkemisen tai muuttamisen varalle. Riittävien resurssien ja tietotaidon turvaaminen niin hallinnossa kuin teollisuudessa on ehdoton edellytys toimenpiteiden onnistumiselle.

Biovoimalaitoksen energiatehokkuuden parantaminen ja osakuorma-ajon optimointi

Energiatehokkuus on nykyaikana yksi tärkeimmistä energiataloudellisista tekijöistä voimalaitosten sähköntuotannossa. Varsinkin yhteistuotantolaitoksissa joissa sähkö on lämpöenergian lisänä saatava sivutuote, sähkön tuotannon optimointi voi merkitä laitostalouden ja yrityksen kannalta huomattavia lisätuloja tai -säästöjä. Kaukaan Voima Oy:n biovoimalaitos on vuonna 2009 kaupalliseen käyttöön valmistunut moderni yhteistuotantolaitos, joka sijaitsee Lappeenrannassa UPM Kaukas sellutehtaan tehdasalueella. Voimalaitos tuottaa kaukolämpöä ja sähköä Lappeenrannan kaupungille sekä prosessihöyryä ja sähköä UPM Kaukaan tehtaille. Tämän työn tavoitteena on tarkastella biovoimalaitoksen omakäyttösähkön kulutusta kuukausitasolla verrattuna laitoksella tuotettavan höyryn määrään sekä etsiä voimalaitokselta kohteita, joiden omakäyttösähkön kulutusta voidaan vähentää vaikuttamatta höyryntuotantoon ja näin parantaa laitoksen energiatehokkuutta ja hyötysuhdetta. Työ rajataan käsittelemään voimalaitoksen apulaitteiden ja -järjestelmien omakäyttösähkön kulutusta. Työssä tarkastellaan vuodenaikojen vaihtelun ja kaukolämmön sekä prosessihöyryn tarpeen muutoksen vaikutusta voimalaitoksen ajomalliin sekä höyryntuotannon ja omakäyttösähkön kulutuksen suhteisiin. Työssä esiin nousseiden kohteiden potentiaaliset sähköenergian säästöt ovat noin 2500 MWh vuodessa joka tarkoittaa keskimäärin 3,7 % vähennystä voimalaitoksen kuukausittaiseen omakäyttösähkön kulutukseen. Kohteet eivät käytännössä vaadi minkaanlaista investointirahaa, vaan uusia ajojärjestelyitä. Keskeisimmiksi säästökohteiksi valikoitui laitoksen pumppausjärjestelmien paineenalennukset.

„Und frei erklär' ich alle meine Knechte“ : Höflichkeit als Ausdruck sozialer Utopie in Schillers Drama Wilhelm Tell.

My dissertation is an interdisciplinary study of the relationship between the Swiss peasants and nobles in Friedrich Schiller’s play Wilhelm Tell (1804). Changes to this relationship are of particular interest. Communication in the play is examined via a micro-analysis based on Penelope Brown’s and Stephen C. Levinson’s theoretical framework Politeness: Some universals in language usage. (1978, 1987). Brown and Levinson distinguish between positivepoliteness and negative-politeness strategies and their distinction is useful for my argument, since they claim that the use of positive-politeness strategies reflects the speaker’s intention to minimize the distance between the interlocutors (Brown and Levinson 1987: 103). Negative-politeness strategies, by contrast, result in social distancing (Brown and Levinson 1987: 130). In accordance with Brown’s and Levinson’s theory, it can be argued that the distribution of positive-politeness and negative-politeness strategies reflects changes in the distance between the fictional interlocutors as representatives of their social classes in Wilhelm Tell. The analysis of the communication in the play highlights that existing conflicts within the social groups are resolved and replaced with solidarity (cf. ‘Claim ’common ground’ and ‘Claim in-group membership with H’) before the peasants and noblemen appear on stage simultaneously in III, 3. In the scene in question, Geßler forces Tell to shoot the apple off his son’s head. Although both nobles and peasants are present, they do not communicate with each other. Thus, communication between the social classes occurs for the first time in IV, 2. This scene is crucial with regard to the changes in the relationship between the social classes in the play. The younger generation, with Rudenz as a representative of the nobility and Melchthal as a representative of the peasants, break with the prevailing conventions and initiate a new type of cooperation based on mutual helping and equality in the right and the duty to protect the country from the violent oppressors representing Habsburg (cf. ‘Convey that S and H are cooperators’, ‘Claim reflexivity’ and ‘Claim reciprocity’). The linguistic analysis reveals the crucial role of the Swiss nobility in the development of the social utopia, as well as the non-contribution of Wilhelm Tell. In fact, Tell never communicates with the Swiss noblemen. The role of the nobility and the role of Wilhelm Tell are further investigated in a comparison between Schiller’s Wilhelm Tell and four of Schiller’s historical sources. These sources, which contain earlier, non-dramatic versions of the establishment of the Swiss Confederation, are the following: Kronica von der loblichen Eydtgnoschaft compiled by Petermann Etterlin (1507), Gemeiner loblicher Eydgnoschafft Stetten Landen vnd Völckeren Chronik wirdiger thaaten beschreybung (1548) written by Johann Stumpf, Chronicon Helveticum of Aegidius Tschudi (the publication of Iselin from 1734 and 1736) and Johannes von Müller’s Geschichten schweizerischer Eidgenossenschaft (1786). Thecomparison sheds light on the fact that both Tschudi and von Müller emphasize unity among the Swiss and cooperation in their attempt to defeat the enemy. However, Schiller has reinforced the role of the nobility in the cooperation. In addition, the comparison between Schiller’s play and the historical sources reveals profound differences with regard to the role of Wilhelm Tell. In all of Schiller’s sources, Tell is present at Rütli, whereas he is absent from Rütli in Schiller’s play. In the play in general, Tell is conspicuously separated from the other peasants. Explanations of my linguistic results, which correspond to the above mentioned differences between the roles of the figures in Wilhelm Tell and the depictions in Schiller’s sources, are found by comparing the path of Schiller’s Swiss towards an egalitarian perspective with the kind of social evolution depicted by the German philosopher Johann Benjamin Erhard in his essay Über das Recht des Volks zu einer Revolution (1795). Aiming at considering Schiller’s social utopia within the larger cultural framework of the German response to the French Revolution, the comparison suggests that both authors depict the need for social change in terms of a change in social hierarchies (Erhard 1970: 95-96, cf. Foi 2005: 225). Erhard’s essay thus helps explain the political intention of Schiller’s play to keep the ideals of the French Revolution as crucial aims but profoundly change the means towards freedom and equality. In his attempt to claim the political resistance of the nobles and peasants as just, however, Schiller sacrificed the figure of Wilhelm Tell. Guilty of the murder of Geßler, Tell was no longer suitable for the righteous revolution imagined by Schiller (cf. Bloch 2008: 215 and Schulz 2005: 228). This explains Tell’s absence in the Rütli scene, his isolation in the plot, as well as his non-contribution to the social utopia. Together, the linguistic analysis and contextualisation of Schiller’s play support my hypothesis that Wilhelm Tell describes a process of change in the relationship between peasants and nobles. The interdisciplinary approach to the topic proved to be fruitful for all areas of the research involved.

Save Consumers Time and Money: Thou Shall Not Forget Digital Native Big Data Consumers

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Etologian suuria nimiä

Kirjallisuusarvostelu

Employees’ continuous learning and job satisfaction - effects on productivity

In today’s knowledge intense economy the human capital is a source for competitive advantage for organizations. Continuous learning and sharing the knowledge within the organization are important to enhance and utilize this human capital in order to maximize the productivity. The new generation with different views and expectations of work is coming to work life giving its own characteristics on learning and sharing. Work should offer satisfaction so that the new generation employees would commit to organizations. At the same time organizations have to be able to focus on productivity to survive in the competitive market. The objective of this thesis is to construct a theory based framework of productivity, continuous learning and job satisfaction and further examine this framework and its applications in a global organization operating in process industry. Suggestions for future actions are presented for this case organization. The research is a qualitative case study and the empiric material was gathered by personal interviews concluding 15 employee and one supervisor interview. Results showed that more face to face interaction is needed between employees for learning because much of the knowledge of the process is tacit and so difficult to share in other ways. Offering these sharing possibilities can also impact positively to job satisfaction because they will increase the sense of community among employees which was found to be lacking. New employees demand more feedback to improve their learning and confidence. According to the literature continuous learning and job satisfaction have a relative strong relationship on productivity. The employee’s job description in the case organization has moved towards knowledge work due to continuous automation and expansion of the production process. This emphasizes the importance of continuous learning and means that productivity can be seen also from quality perspective. The normal productivity output in the case organization is stable and by focusing on the quality of work by improving continuous learning and job satisfaction the upsets in production can be handled and prevented more effectively. Continuous learning increases also the free human capital input and utilization of it and this can breed output increasing innovations that can increase productivity in long term. Also job satisfaction can increase productivity output in the end because employees will work more efficiently, not doing only the minimum tasks required. Satisfied employees are also found participating more in learning activities.

Multivariate genetic divergence and hybrid performance of cacao (Theobroma cacao L.)

Genetic distances among cacao cultivars were calculated through multivariate analysis, using the D2 statistic, to examine racial group classification and to assess heterotic hybrids. A 5 x 5 complete diallel was evaluated. Over a five-year period (1986-1990), five cultivars of the S1 generation, pertaining to the Lower Amazon Forastero and Trinitario racial groups and 20 crosses between the corresponding S0 parents were analyzed, based upon five yield components - number of healthy and collected fruits per plant (NHFP and NCFP), wet seed weight per plant and per fruit (WSWP and WSWF), and percentage of diseased fruits per plant (PDFP). The diversity analysis suggested a close relationship between the Trinitario and Lower Amazon Forastero groups. A correlation coefficient (r) was calculated to determine the association between genetic diversity and heterosis. Genetic distance of parents by D2 was found to be linearly related to average performance of hybrids for WSWP and WSWF (r = 0.68, P < 0.05 and r = 0.76, P < 0.05, respectively). The heterotic performance for the same components was also correlated with D2, both with r = 0.66 (P < 0.05). A relationship between genetic divergence and combining ability effects was suggested because the most divergent cultivar exhibited a high general combining ability, generating the best performing hybrids. Results indicated that genetic diversity estimates can be useful in selecting parents for crosses and in assessing relationships among cacao racial groups.

Photochemistry and photobiology of actinic erythema: defensive and reparative cutaneous mechanisms

Sunlight is part of our everyday life and most people accept it as beneficial to our health. With the advance of our knowledge in cutaneous photochemistry, photobiology and photomedicine over the past four decades, the terrestrial solar radiation has become a concern of dermatologists and is considered to be a major damaging environmental factor for our skin. Most photobiological effects (e.g., sunburn, suntanning, local and systemic immunosuppression, photoaging or dermatoheliosis, skin cancer and precancer, etc.) are attributed to ultraviolet radiation (UVR) and more particularly to UVB radiation (290-320 nm). UVA radiation (320-400 nm) also plays an important role in the induction of erythema by the photosensitized generation of reactive oxygen species (singlet oxygen (1O2), superoxide (O2.-) and hydroxyl radicals (.OH)) that damage DNA and cellular membranes, and promote carcinogenesis and the changes associated with photoaging. Therefore, research efforts have been directed at a better photochemical and photobiological understanding of the so-called sunburn reaction, actinic or solar erythema. To survive the insults of actinic damage, the skin appears to have different intrinsic defensive mechanisms, among which antioxidants (enzymatic and non-enzymatic systems) play a pivotal role. In this paper, we will review the basic aspects of the action of UVR on the skin: a) photochemical reactions resulting from photon absorption by endogenous chromophores; b) the lipid peroxidation phenomenon, and c) intrinsic defensive cutaneous mechanisms (antioxidant systems). The last section will cover the inflammatory response including mediator release after cutaneous UVR exposure and adhesion molecule expression