När orsakerna till brottslighet har studerats har kriminologisk forskning och teori traditionellt fokuserat på individuella egenskaper och på riskfaktorer hos brottslingar, eller på olika socioekonomiska faktorer. Kriminologisk forskning om brottslighetens geografiska fördelning har dock ökat och fått större utrymme och acceptans både bland forskare och bland de samhällsinstanser som arbetar mot brottslighet. Hot spots utgörs av små områden där det sker mycket fler brott än i omgivande områden. Flera studier har visat att några få områden står för merparten av brottsligheten när enskilda brottstyper studeras. Syftet med denna studie var att analysera hur brottsligheten koncentrerar sig geografiskt i Sundsvall, samt att jämföra hur brottslighetens fördelning har förändrats mellan åren 2010 och 2015. Studien bygger på en analys av anmälningar inkomna till polisen i Sundsvall under perioderna 1 januari till 31 december 2010 samt 1 januari till 31 december 2015. Anmälningarna som studerades delades sedan upp i de fyra brottstyperna våldsbrott, narkotikabrott, inbrott samt tillgreppsbrott. Resultatet visade att brottsanmälningarna i Sundsvall koncentrerade sig till hot spots. Var dessa hot spots var placerade geografiskt skiljer sig åt mellan olika brottstyper, men en viss överrepresentation av anmälningar kunde ses på ett antal platser oavsett brottstyp. Varje undersökt brottstyp diskuteras utifrån socialekologisk teori och Crime pattern theory. I diskussionen ges även förslag på i vilka situationer det kan vara effektivt att använda sig av platsbaserat polisiärt arbete och i vilka situationer andra preventiva åtgärder kan vara mer effektiva. / <p>2016-06-01</p>

Inledning: Forskning har visat att miljön där brott sker är avgörande för att förstå kriminalitetsmönster och dess koncentration i och till olika områden, även kallade hot spots. Socialekologisk teori ämnar förklara distributionen av kriminalitet i städer. Syftet med aktuell studie var dels att analysera vilka platser i en stad som har flest anmälningar för misshandelsbrott för individer över 18 år, dels att analysera polisarbetet i och anslutning till dessa platser i Uppsala innerstad under åren 2013 – 2015. I denna studie har Brottsmönsterteorin applicerats för att förklara resultatet. Metod: I denna studie tillämpades både kvalitativ och kvantitativ metod. Materialet som användes var polisregister för misshandelsbrott, dokument som beskriver polisens arbete samt en intervju. Anmälningarna från polisregistret fördes in i ArcGIS, ett datorprogram för visualisering av kartor, för att ta fram hot spots. Vidare analyserades polisens arbete på eller i nära anslutning till dessa platser. Resultat: I studien identifierades fyra hot spots. Resultatet visade att anmälningsfrekvensen hade minskat i två av fyra hot spots (hot spot 2 och 3). Det totala antalet misshandelsanmälningar i Uppsala innerstad hade minskat i förhållande befolkningsmängden i Uppsala kommun. Det problemorienterade polisarbetet fokuserade under treårsperioden på platser med hög alkoholkonsumtion och med en stor omsättning av människor. Slutsats: Kartläggning av olika typer av brott är effektivt för att arbeta brottspreventivt. För vissa typer av brott så som misshandel, kan det för polisen vara väl så effektivt att arbeta problemorienterat i hot spots såsom mot individer. / <p>2016-06-01</p>

För en patient som vårdas inom sluten psykiatrisk vård innebär det en stor påverkan på integriteten. Detta intrång kan resultera i att konflikt mellan patient och vårdare uppstår, och i sin tur att våld eller hot uppstår. Det saknas konsensus kring vad definitionen av våld är och verbala hot ses ibland som del av vardagen. Arbetsmiljön har en betydande roll när det kommer till uppkomsten av hot- och våldssituationer. Det finns tidigare forskning som visar att hot och våld förekommer inom psykiatrisk vård men vår studie syftar till att beskriva i vilken utsträckning hot och våld förekommer inom sluten psykiatrisk vård, samt vad som kännetecknar dessa situationer. Studien är en kvantitativ tvärsnittsstudie som genomfördes med hjälp av en enkät och utfördes med ett bekvämlighetsurval med anledning av genomförbarheten, tidsaspekten och studienivån. Bekvämlighetsurvalet om 49 vårdare som arbetade inom sluten psykiatrisk vård besvarade enkäten, Violent Incident Form. Enkäten bestod av 17 frågor rörande upplevd förekomst av hot eller våld. Resultatet visar att 87,8% hade blivit utsatta för hot och/eller våld på sin nuvarande arbetsplats. Det förekom oftast i dagrummet under undersökning/behandling/omvårdnad och den vanligaste typen av hot och våld var verbala hot. Studiens resultat överensstämmer väl med de tidigare studier som kunnat identifieras från både Sverige och andra länder. Dock kunde inga orsakssamband identifieras. En uppfattning om hur typexemplet på hur en hot- och våldssituation bland de medverkande såg ut kunde bildas. Nya forskningsmöjligheter om hur verbala hot påverkar arbetsmiljön och kliniska implikationer som att öka medvetenheten om kritiska tidpunkter och erbjuda utbildning på arbetsplatsen framhävs.

El proyecto de compresas calientes son productos para rehabilitación en caliente que propone una forma de negocio innovadora, que se basa en un producto reutilizable que complementa el tratamiento para lesiones, problemas musculares y alivio de dolor para deportistas y personas que sufran alguna lesión muscular. En este negocio se propone aliviar, combatir las lesiones causadas por diferentes funciones y acciones durante el día a día, lo cual ocasiona que todos tengan cansancio, dolores y contracciones en el cuerpo, tomando esto como un factor de reducción de movimientos. Ante estos problemas se presenta el producto de compresas calientes, que tienen la ventaja de no detener las actividades de las personas y sean adaptables a la zona afectada, generando una satisfacción de alivio y mantenimiento muscular positivo. El producto está elaborado en PCV Termo plástico material que se ablanda mediante el calor y se endurece a la hora de enfriarse, siendo un producto reutilizable de fácil uso para el cliente. Este producto está dirigido a las personas de 18 a 50 años, de los sectores A, B y C1 que realizan deporte y actividades físicas de Lima metropolitana, por ser la zona de operación de la empresa. Respecto a la evaluación financiera, se proyectaron los flujos de caja para cinco años y se concluyó que el negocio será viable y rentable para sus inversionistas por sus resultados VAN de S/27,259 y TIR de 79%. Así mismo, se determinó la inversión inicial de S/69,733 para poner en marcha a la empresa. / The project of hot compresses are products for hot rehabilitation that proposes an innovative form of business, which is based on a reusable product that complements the treatment for injuries, muscle problems and pain relief for athletes and people suffering from any muscle injury. In this business it is proposed to alleviate, fight injuries caused by different functions and actions during the day to day, which causes everyone to have fatigue, pains and contractions in the body, taking this as a factor of movement reduction. Faced with these problems, the product of hot compresses is presented, which has the advantage of not stopping the activities of the people and being adaptable to the affected area, generating a satisfaction of relief and positive muscular maintenance. The product is made of PCV Termo plastic material that is softened by heat and hardens when it cools, being a user-friendly reusable product. This product is aimed at people from 18 to 50 years of age, sectors A, B and C1 that carry out sport and physical activities in metropolitan Lima, as it is the area of operation of the company. Regarding the financial evaluation, cash flows were projected for five years and it was concluded that the business will be viable and profitable for its investors due to its NPV results of S / 27,259 and TIR of 79%. Likewise, the initial investment of S / 69,733 was determined to start up the company. / Trabajo de investigación

The goal of this PhD thesis was to develop dense aluminium compound-cubic boron nitride composites with a high cBN content. To achieve this goal, two different strategies were used: infiltration of cBN preforms and hot pressing of cBN-Al mixtures. The particle size of the cBN and the amount of aluminium were systematically varied and the influence of these parameters on densification and selected properties was evaluated. A basic understanding of the product that was formed over certain temperatures and times provides information that can be used in optimizing the infiltration and hot pressing of cBN with Al. For this reason, the reaction kinetics between Al and cBN was initially investigated. The reaction kinetics of the chemical interactions between Al and cBN was investigated in detail using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The reaction was studied using samples containing 50 volume percent of Al and 50 volume percent of cBN (12 μm) hot pressed at 800 oC. The prepared samples were allowed to react isothermally at temperatures between 1 000 oC and 1 400 oC under nitrogen (N2) and argon (Ar) atmospheres. It was found that the degree and rate of the reactions increased with increasing temperature in both N2 and Ar atmospheres. The degree of aluminium nitride (AlN) formation was considerably higher under N2 than under Ar. The difference in the formation of AlN between the two atmospheres was attributed to the reaction of N2 gas with the sample due to the open porosity. The infiltration of partially hexagonalized cBN matrix with molten Al was studied. The samples were found to have a density higher than 97% of the theoretical density. It was found that the amount of soft hBN phase present in the sample (due to hexagonalization) increases at temperatures higher than 1 300 oC, resulting in a hardness of the final material of Hv10 = 6.5 ± 4.8 GPa. Because of thie poor hardness this route was abandoned. Cubic boron nitride powder (12 μm) without hexagonal boron nitride (hBN) was also infiltrated with aluminium. The infiltrated samples were found to exhibit a density higher than 96% of the theoretical density. The Al reacted with cBN and no hBN was observed at temperatures below 1 400 oC. The resulting product showed a Vickers hardness of Hv10 = 14.4 ± 1.6 GPa compared with Hv10 = 6.5 ± 4.8 GPa obtained with the partially hexagonalized cBN matrix. Infiltration of 3 μm cubic boron nitride increased the Vickers hardness to 22.0 ± 0.6 GPa. However, this infiltration was not very reproducible. Al-cBN cermets were hot pressed at temperatures between 800 oC and 1 750 oC and at a pressure of 50 MPa in vacuum. The effect of the particle size of the starting powders, as well as the effect of the starting compositions and temperature, was investigated. The materials could only densify up to 80 – 92% of the theoretical density. After hot pressing at 800 oC, only Al and cBN could be observed by XRD, whereas higher hot-pressing temperatures resulted in the formation of AlN and AlB2 which retard the densification. The microstructure of the hot-pressed materials was studied using SEM. It was observed that there are oxide layers at the interface between the Al and cBN phases. The presence of these oxide layers prevented the Al from spreading, thereby preventing full densification.

La fissuration à chaud par liquation peut se produire dans la zone affectée thermiquement lors du soudage. Deux facteurs influent ce phénomène : les contraintes thermiques dues au gradient de température et la perte potentielle de ductilité due à la présence d'un film liquide aux joints de grains en fonction de leur composition chimique. Des essais de ductilité à chaud (Gleeble) ont été utilisés pour étudier l'effet combiné de la teneur en bore et du temps de maintien sur la chute de la ductilité dans la plage de température de liquation pour l’acier inoxydable austénitique de type 316L. Il est démontré que les teneurs en bore élevées et les temps de maintien courts favorisent la perte de ductilité dans cette plage de température. En complément la spectrométrie de masse à ionisation secondaire a été utilisée pour tenter de corréler les variations de ductilité à la distribution du bore aux joints de grains. D'autres essais de fissuration à chaud en soudage (Varestraint, PVR) ont été effectués pour confirmer l'influence de la teneur en bore sur la sensibilité à la fissuration de l’acier 316L. Les résultats indiquent que des fissures apparaissent sur toutes les éprouvettes et que le chargement mécanique externe minimal pour créer les fissures de liquation diminue avec la teneur en bore. Plus la teneur en bore est élevée, plus le matériau est donc sensible à la fissuration à chaud par liquation. Un critère de fissuration à chaud par liquation a été déterminé en se basant sur les résultats des essais de ductilité à chaud et la simulation des essais de soudage. / Liquation cracking may occur in the heat-affected zone during welding. Two factors influence this phenomenon: the tensile stresses generated during welding and the potential loss of ductility due to the presence of a liquid film at grain boundaries depending on their chemical composition. Gleeble hot ductility tests have been used to study the combined effect of boron content and holding time on ductility drop in the liquation temperature range of a 316L type austenitic stainless steel. It is shown that high boron contents and short holding times promote the loss of ductility in this temperature range. Secondary ion mass spectrometry has been used inattempt to correlate mechanical results to boron distribution either at grain boundaries or in the bulk. Other hot cracking tests (Varestraint, PVR) have been performed to confirm the influence of boron content on hot cracking sensitivity of AISI 316L stainless steels during welding. Results indicate that cracks appear on all specimens and that the minimum external mechanical loading for liquation cracking decreases with boron content. The higher the boron content is, the more the specimen exhibits tendency to hot cracking. A liquation hot cracking criterion has been determined, based on the results of the hot ductility tests and the simulation of welding tests.

O processo de estampagem à quente é um dos métodos possíveis para a conformação de aços de alta resistência. Para isso é necessário o estudo das propriedades termomecânicas para obtenção de parâmetros ótimos para a construção de uma linha de estampagem eficiente. Neste trabalho, foram realizados ensaios para determinar os parâmetros para a estampagem a quente do aço 22MnB5, e posteriormente a construção de uma linha de estampagem a quente completa. Obteve-se ao fim do processo, uma microestrutura martensitica com dureza de 430 HV com resistência à tração de aproximadamente 1365 MPa. / The hot stamping process is one of the possible ways to high strenght steel conformation. In this work, study of 22MnB5 steel thermomechanical properties was performed in order to obtain optimum parameters to hot stamping process. After, a complete hot stamping line was built. At the end of hot stamping process it was possible to obtain a martensitic microstructure with 1365 MPa strenght resistance and 430 HV.

Thesis advisor: Zhifeng Ren / Solid state cooling and power generation based on thermoelectric principles are regarded as one of the technologies with the potential of solving the current energy crisis. Thermoelectric devices could be widely used in waste heat recovery, small scale power generation and refrigeration. It has no moving parts and is environmental friendly. The limitation to its application is due to its low efficiency. Most of the current commercialized thermoelectric materials have figure of merit (ZT) around 1. To be comparable with kitchen refrigerator, ZT is required at room temperature. Skutterudites have emerged as member of the novel materials, which potentially have a higher ZT. In the dissertation, my investigation will be focused on the optimization of CoSb₃ &ndash based skutterudites. Starting with Co and Sb elements, CoSb₃ will form through a high energy ball mill. Unfortunately, even after 20 hours, only a small percentage of the powders have transformed in into CoSb₃. Then the powders will be compacted into bulk samples by DC-controlled hot press. CoSb₃ single phase will form after press. Characterization of the structure and thermoelectric properties will be presented with details. The effects of synthesis conditions on thermoelectric properties of skutterudites were studied and discussed. Several possible methods of improving the ZT of N type skutterudites were applied. The highest obtained ZT thus far is about 1.2 from Yb doped CoSb₃. For a group of samples with nominal composition Yb_xCo₄Sb₁₂, the increased Yb concentration in our samples not only enhanced the power factor due to electron doping effect but also decreased the thermal conductivity due to a stronger rattling effect. In addition, the increased grain boundary density per unit volume due to the small grains in our bulk skutterudite materials may have also helped to enhance the phonon scattering and thus to reduce the thermal conductivity. Single and double doping methods with different combinations were also tried. So far, none of them have surpassed ZT of 1.2. Mixing different materials with Yb_0.35Co₄Sb₁₂ so far to increase the phonon scattering was also performed. No dramatic thermal conductivity reduction was observed. Small amounts of Fe/Mn substitution on Co sites will decrease the power factor to undesired degrees. Some results with Nd filled P type sample will be briefly introduced. P type samples are also obtained through substitution on Sb site. Preliminary work on preparing the electrode for CoSb₃ will be presented in the dissertation. CoSi₂ has low resistivity, and a similar coefficient of thermal expansion (CTE) as of doped CoSb₃. It is good electrode candidate. DC controlled hot press is used to make the contact. Thermal stability of the contact was tested. Small cracks will form in the contact area, further improvement is necessary. Finally, my previous work on ZnO nanowire growth is briefly introduced. Large throughput of ZnO nanowire could be obtained with NaCl as the support to promote the conversion of Zn powder to ZnO. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Thesis advisor: Zhifeng Ren / Thermoelectric (TE) technology is an environment-friendly one due to reduction of carbon emission, which can be widely used either for power generation or for refrigeration. Basically applications of TEs are based on TE effects, which involve the transition between heat and electricity. Despite the superior advantages of being solid state and providing a clean form of energy, TE technology so far only finds its niche area of application due to the relatively less efficiency compared to traditional methods. The efficiency of a thermoelectric device is solely determined by the dimensionless figure-of-merit (ZT) of thermoelectric materials. According to the definition, ZT is equal to square of Seebeck coefficient times electrical conductivity times absolute temperature divided by thermal conductivity. Therefore, a good thermoelectric material should possess high Seebeck coefficient and electrical conductivity while low thermal conductivity, so called phonon glass electron crystal (PGEC). In bulk materials, it is challenging to further improve ZT or independently vary individual parameters without affecting others, mainly due to the interrelated relationships among these three parameters. Fortunately, nano approach gives us some independent control in parameters adjustment. One important aspect of nano idea lies in the fact that enhanced boundary scattering due to the increased intensities of interfaces arising from nano-sized grains could reduce the thermal conductivity more than the electrical conductivity, which is practically realized in our material system. Since the introduction of nano idea, large ZT as high as above two has been achieved in the superlattice system. Due to the high fabrication cost of superlattices, they are not scalable for mass production. Theoretical calculations indicate that thermal boundary resistance is the main mechanism for the low thermal conductivity in superlattices, rather than the periodicity. Basically, we hope to achieve the supplattice-like ZT in the less costly bulk nanograined materials, based on the idea that reduction of thermal conductivity which is responsible for ZT enhancement in superlattices can be realized in bulk materials with embedded nanostructures as well. Inspired by the nanocomposite idea, in my thesis work I applied the technique of ball milling and then hot press to various thermoelectric materials, from low temperature to high temperature, demonstrating the feasibility of the approach. By ball milling alloyed ingot into nanopowders and DC hot pressing them, we have achieved a 62-89% ZT improvement for p-type half-Heusler samples, mainly due to the significantly enhanced Seebeck coefficient and partially due to the moderately reduced thermal conductivity. Microstructure studies indicated that increased boundaries due to smaller nano-sized grains is the cause for change of parameters. For our ball milled samples, the trend of decreasing thermal conductivities with increasing ball milling time is observed, further substantiating our nano-approach idea because longer ball milling time gives rise to smaller grain sizes and thus stronger boundary scattering. By applying the same technique to n-type half-Heuslers, we also successfully obtained pronounced enhancement in ZT especially at medium and low temperature ranges, which might be useful in medium temperature power generation. By ball milling a mixture of individual constituent elements into alloyed nanopowders and then DC hot pressing them, we did not gain improvement in ZT initially for n-type BiTeSe system mainly due to the simultaneous reduced power factor with the thermal conductivity. Considering anisotropic properties of the n-type BiTeSe single crystal and randomization effect of ball milling process, we repressed the as-pressed bulk samples in a bigger diameter die, during which lateral flow took place, resulting in preferred grain orientation. As a result, a 22% improvement in the peak ZT from 0.85 to 1.04 at 125 oC in n-type Bi₂Te_2.7Se_0.3 has been successfully achieved, arising from the more enhanced power factor than the thermal conductivity. Compared with single crystal, we benefit from the small nano-sized grains in bulk materials. Taking into account the in-plane power factor of single crystal, we still have much room for further ZT improvement if more ab orientation is promoted into the disk plane and/or the crystal plate size and thickness are reduced. By applying our technique of ball milling and then hot press to p-type skutterudites system, we have achieved a peak ZT of 0.95 at 450 <super>o</super>C in NdFe_3.5Co_0.5Sb₁₂, which is comparable to that of the state-of-the-art ingot. Our approach has the advantage of being less costly and more time-efficient compared to traditional fabrication methods. Besides, even lower thermal conductivity and hence higher ZT can be expected, provided that the nanosize of the precursor powder is preserved during hot press. The nanocomposite idea has been substantiated and the feasibility and generality of our ball milling and then hot press approach has been demonstrated, based on the thermoelectric properties data we obtained and the microstructure studies we carried out from various thermoelectric material systems, from low temperature to high temperature. We believe that continued effort in the area of thermoelectrics by our approach should be paid with superlattice-like ZT if ingenious methods are devised to control the grain growth during consolidation. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Bakgrund: Hot och våld är ett växande problem på akutmottagningar och kan innebära en mer utsatt position för sjuksköterskor och annan personal i jämförelse med situationer på andra avdelningar. Akutmottagningen som arbetsplats innebär dessutom ett högt arbetstempo och ofta krav på snabba beslut under akuta situationer. Dessa nämnda förhållanden på akutmottagnigne påverkar i högsta grad sjuksköterskans arbetssituation, möjligheten att utöva sin profession och att ge säker vård. Syfte: Att beskriva sjuksköterskans upplevelse av hot och våld på akutmottagningen. Metod: En litteraturöversikt med kvalitativa artiklar och ett induktivt förhållningssätt genomfördes. Resultat Hot och våld kan förekomma verbalt eller fysiskt, eller både och. Sjuksköterskornas upplevelse av hot och våld på akutmottagningen skilde sig mellan olika individer. De hotfulla situationerna var nästan dagligen återkommande, vilket ledde till att sjuksköterskor anpassade sig till att hot och våld var en del av omvårdnadsarbetet på akutmottagningen. Konsekvenserna kan vara fysiska, psykiska, existentiella och sociala men även riskera att påverka det professionella utförandet av sjuksköterskans omvårdnadsarbete. Slutsats: Sjuksköterskor på akutmottagningen arbetar i en utsatt miljö där hot och våld är förekommande. Genom att aktivt förebygga, utbilda och arbeta för nolltoleransen mot hot och våld kan en säker vård för sjuksköterskor och patienter uppnås.