Ympäristökasvatus alakoulukontekstissa

Tiivistelmä. Kandidaatintutkielman aiheena on ympäristökasvatus alakoulukontekstissa. Aluksi käsitellään teoreettista viitekehystä, joka määrittelee tutkielman suunnan. Katsauksen tavoitteena on saada vastaus tutkimuskysymykseen mitä ympäristökasvatus alakoulussa sisältää? Teoreettisena lähtökohtana tutkielmalle on opetussuunnitelmissa esiintyvä ympäristökasvatus. Tutkielmassa käsitellään Opetushallituksen perusopetuksen opetussuunnitelman perusteita vuodelta 2014 sekä muita aiheen kannalta tietoteoreettisesti relevantteja lähteitä. Tutkimusongelman asettelu on syntynyt ilmastonmuutoksesta johtuvasta ympäristöhuolesta. Tutkielma on toteutettu kuvailevana kirjallisuuskatsauksena. Aineistoa on kerätty lukuisista kansallisista ja kansainvälisistä lähteistä. Lähteinä tutkielmassa on pyritty käyttämään vertaisarvioituja kirjoja, artikkeleita, nettisivustoja ja muita teoksia. Aineiston analyysi- ja tulkintaprosessi on tehty ajankuvaan sopivalla tunneherkällä ja kriittisellä lähestymistavalla. Monipuoliset lähteet haastavat ja tukevat toisiaan. Sitä kautta kirjoittaja voi tutkia aihetta tasapuolisesti. Tutkielman tulokseksi saatiin paljon alakoulukontekstin kannalta olennaista tietoa. Ympäristökasvatusta alakoulussa on hyvin paljon. Perusopetuksen opetussuunnitelma määrittelee opetuksen suomalaisissa kouluissa ja luo sitä kautta raamit myös ympäristökasvatukselle. Alakoulukontekstissa ympäristökasvatusta toteuttaa eri oppiaineet, pääasiassa kuitenkin ympäristöoppi. Ympäristöopin oppiaineessa vuosiluokilla 1–2 ja 3–6 käsitellään ympäristökasvatusta erilaisten tavoitteiden kautta. Näitä ovat esimerkiksi kierrättäminen, muovin oikeanlainen käyttö ja erilaisiin elinympäristöihin tutustuminen. Katsauksen tuloksina nähtiin myös tunteiden runsas kirjo ympäristökasvatuksessa. Ympäristökasvatus on ajatuksia herättävä ja jopa pelottava aihe, joten aihetta käsiteltäessä tulee olla erityisen sensitiivinen. Ympäristökasvatuksen aiheuttamia tunteita saa kokea, mutta kasvattajien vastuulla on toivon näköalan luominen. Tutkielma on toteutettu tiedekunnan ohjeiden mukaisesti soveltaen eettisiä periaatteita. Lähteet, jotka kirjallisuuskatsauksessa ovat suuressa roolissa, ovat monipuolisia ja luotettavia. Tutkielma on toteutettu kriittisesti ja objektiivisesti. Tämä lisää tutkimuksen luotettavuutta, tulosten yleistettävyyttä ja käytännön sovellusmahdollisuuksia, esimerkiksi alakoulumaailmassa

Comparison of 'shallow' and 'deep' junction architectures for MBE-grown InAs/GaAs quantum dot solar cells

We report on the fabrication of InAs/GaAs quantum dot solar cells with high open circuit voltage by molecular beam epitaxy. `Shallow' and `deep' junction architectures were compared. The highest open circuit voltage of 0.94 V was obtained for the `shallow' junction configuration. The open circuit voltage of InAs quantum dot solar cells decreased only by ~40 mV compared to GaAs reference cells for both junction architectures indicating high quality quantum dots. The open circuit voltage of InAs/GaAs quantum dot solar cells was also found to be dependent on the size of quantum dots

Back Reflector with Diffractive Gratings for Light-Trapping in Thin-Film III-V Solar Cells

We report on the development of light-Trapping architectures applied to thin-film solar cells. In particular, we focus on enhancing the absorption at 1-eV spectral range for dilute nitride and quantum dot materials and report on the influence of planar back reflectors on the photovoltaic properties. Moreover, we discuss the properties of polymer diffraction gratings with enhanced light-Trapping capability pointing to advantageous properties of pyramidal gratings. In order to understand the suitability of these polymer grating architectures for space applications, we have performed an electron irradiation study (1 MeV) revealing the absence of reflectance changes up to doses of 1×1015 e-/cm

Thin-film InAs/GaAs quantum dot solar cell with planar and pyramidal back reflectors

Quantum dot solar cells are promising for next-generation photovoltaics owing to their potential for improved device efficiency related to bandgap tailoring and quantum confinement of charge carriers. Yet implementing effective photon management to increase the absorptivity of the quantum dots is instrumental. To this end, the performance of thin-film InAs/GaAs quantum dot solar cells with planar and structured back reflectors is reported. The experimental thin-film solar cells with planar reflectors exhibited a bandgap-voltage offset of 0.3 V with an open circuit voltage of 0.884 V, which is one of the highest values reported for quantum dot solar cells grown by molecular beam epitaxy to our knowledge. Using measured external quantum efficiency and current-voltage characteristics, we parametrize a simulation model that was used to design an advanced reflector with diffractive pyramidal gratings revealing a 12-fold increase of the photocurrent generation in the quantum dot layers

Comparison of metal/polymer back reflectors with half-sphere, blazed, and pyramid gratings for light trapping in III-V solar cells

We report on the fabrication of diffraction gratings for application as back contact reflectors. The gratings are designed for thin-film solar cells incorporating absorbers with bandgap slightly lower than GaAs, i.e. InAs quantum dot or GaInNAs solar cells. Light trapping in the solar cells enables the increase of the absorption leading to higher short circuit current densities and higher efficiencies. We study metal/polymer back reflectors with half-sphere, blazed, and pyramid gratings, which were fabricated either by photolithography or by nanoimprint lithography. The gratings are compared in terms of the total and the specular reflectance, which determine their diffraction capabilities, i.e. the feature responsible for increasing the absorption. The pyramid grating showed the highest diffuse reflection of light compared to the half-sphere structure and the blazed grating. The diffraction efficiency measurements were in agreement with the numerical simulations. The validated model enables designing such metal/polymer back reflectors for other type of solar cells by refining the optimal dimensions of the gratings for different wavelength ranges

Effects of Recurrent Acute Otitis Media on Cortical Speech-Sound Processing in 2-Year Old Children

Objectives: To investigate at the age of 2 years the effects of childhood recurrent acute otitis media (RAOM) on central auditory processing by using cortical event-related potentials elicited by syllable stimuli. Design: During a 1-year period, 22- to 26-month-old children fulfilling the criteria for tympanostomy tube insertion in Oulu University Hospital, Oulu, Finland, were recruited to the RAOM group (N = 20). The control group (N = 19) was matched by age, sex, and mother&rsquo;s educational level. In both groups, children were typically developing and had no family history of language disorder or developmental language problems. Finnish syllables /ke:/ and /pi:/ as standards and their variants with changes in frequency, intensity, vowel, consonant, and vowel duration as deviants were used to record P1, N2, and mismatch negativity (MMN) responses in the multifeature paradigm. The clinically healthy ears at the time of registration were a prerequisite for the participation. Results: Children with RAOM and their controls showed the age-typical P1 and N2 responses with no differences in the amplitudes or latencies between the groups, which suggests unaffected basic encoding of sound features and sound representation formation. However, the groups showed different auditory discrimination profiles. In children with RAOM, frequency and vowel MMN amplitudes were increased. Furthermore, the MMN latency for the frequency change was shorter and the frequency MMN amplitude lateralized to the left hemisphere in the RAOM group instead of an adult-like right-hemispheric lateralization observed in the controls. The children with RAOM had a more anterior MMN amplitude scalp distribution for the intensity change than control children. In addition, the MMN amplitude elicited by consonant change was evenly distributed unlike in controls, who had a left-side preponderant lateralization. Taken together, these results suggest an elevated responsiveness for frequency, vowel, and intensity changes, and an immature pattern of discriminating small speech sound contrasts in children with RAOM. Conclusions: The results suggest that childhood RAOM does not affect the central auditory pathway integrity or sound encoding. However, RAOM may lead to aberrant preattentive discrimination of sound features even when the peripheral auditory input is normal. These results are clinically significant because even transient problems with auditory processing may delay language development.</div