| 1. |
- Ballem, Mohamed A., et al.
(författare)
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Low Temperature Nanocasting of Ultrafine Hematite Nanoparticles using Mesoporous Silica Molds
- 2012
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Ingår i: Powder Technology. - : Elsevier. - 0032-5910 .- 1873-328X. ; 217, s. 269-273
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Tidskriftsartikel (refereegranskat)abstract
- Iron oxide (α-Fe2O3) nanoparticles with very small size, high crystallinity, and narrow size distribution were synthesized by infiltration of Fe(NO3)3.9H2O as an oxide precursor into mesoporous silica (SBA-15 and SBA-16) molds using a wetimpregnation technique. High resolution transmission electron microscopy shows that during the hydrothermal treatment of the precursor at 140 °C for 2 days, stable α-Fe2O3 nanoparticles inside the silica pores are formed. Subsequent leaching out of the silica template by NaOH resulted in well dispersed nanoparticles with an average diameter of ~ 4 nm.
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| 2. |
- Ehnström, Karl-Ivar, et al.
(författare)
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Luftsolfångares termiska prestanda
- 1993
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Luftuppvärmning är ett utbrett sätt att använda solenergi,bl a i husuppvärmning, luftkonditionering och torkning av jordbruksprodukter. I denna rapport framläggs ett nytt sätt att beräkna värmeprocessen i en luftsolfångare, vilket ger möjlighet till riktigare simulering av icke symmetrisk luftuppvärmning i luftsolfångarens kanaler. En bearbetad analytisk-numerisk metod av tvådimensionell icke stationär temperaturfältsberäkning presenteras, vilket ger möjlighet att göra kompletteringar till simuleringsprogrammet TRNSYS, speciellt avpassat för det sätt som luftsolfångare uppvärmer luften. Vid sidan om den teoretiska analysen av luftsolfångare, framläggs i denna rapport, medodik för experimentella undersökningar av luftsolfångare. Vidare diskuteras krav på mätutrustning vid experimentella mätningar av luftsolfångares termiska prestanda.
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| 6. |
- Jonsdottir, Ingibjörg H, 1966, et al.
(författare)
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Duration and mechanisms of the increased natural cytotoxicity seen after chronic voluntary exercise in rats.
- 1997
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Ingår i: Acta physiologica Scandinavica. - 0001-6772. ; 160:4, s. 333-9
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Tidskriftsartikel (refereegranskat)abstract
- We have recently shown that in vivo natural cytotoxicity is enhanced after chronic exercise in spontaneously hypertensive rats (SHRs). In the present report, we have studied the duration of this augmentation and some possible mechanisms involved. Exercise consisted of voluntary running for 4-5 weeks, with the running distance ranging from 2.7-15.6 km day(-1) during the last week of running. In vivo cytotoxicity was measured as clearance of injected 51Cr-labelled YAC-1 lymphoma cells from the lungs. The in vivo natural cytotoxicity was increased in running SHRs, and also in SHRs that had their running wheel locked for 24 and 48 h prior to the experiment, and was still present after 96 h. The enhancement of in vivo cytotoxicity after 5 weeks of exercise was abolished after an acute injection of the beta-adrenergic receptor antagonist timolol (0.5 mg kg(-1) i.v.), indicating that catecholamines are involved in this augmentation. Interestingly, 24 h after the last exercise bout, the increased natural cytotoxicity could be blocked by timolol. The opioid receptor antagonist naloxone given subcutaneously for 7 days by osmotic pumps (6 mg kg(-1) h(-1)) could not reverse the increased in vivo cytotoxicity seen in the running SHRs, suggesting that opioid receptor mechanisms are not involved, or at least not the naloxone-sensitive mu-receptor. Natural immunity was not influenced by the histamine H2 receptor antagonist ranitidine, either in controls or in runners, indicating that the natural killer cell-regulatory effect of histamine is not present in SHRs and does not seem to be involved in the exercise-induced changes in natural immune function. We conclude that the augmentation of in vivo natural cytotoxicity after voluntary chronic exercise in rats is long-lasting and that the augmentation is partly mediated by beta-adrenergic receptors.
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| 7. |
- Levi-Bliech, Michal, et al.
(författare)
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Mobile apps and employee behavior : An empirical investigation of the implementation of a fleet-management app
- 2019
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Ingår i: International Journal of Information Management. - : Elsevier. - 0268-4012 .- 1873-4707. ; 49, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- Whereas implementing a mobile application (app) in support of organizational processes is quite common in contemporary organizations, only few empirical studies have investigated the impact of app implementation in an organizational context. This study explores the association between the driving behavior of employed drivers and pre-driving app use of a fleet-management app. Users can get from the app not only real-time notifications while driving but can also take advantage of a unique app capability, that more traditional driving technologies do not provide, and receive feedback about their driving before their next drive. We hypothesize that pre-driving app use is associated with reduced risky driving behavior, and that this association is mitigated by real-time notifications and enhanced by experience with the app. The supportive results of the study confirm the organizational impact of implementing a fleet-management app via better driving behavior of employees who engage in pre-driving app use.
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| 8. |
- Moskowitz, Robert, et al.
(författare)
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Trustworthy Device Identifiers For Unmanned Aircraft and Other Mobile Things
- 2024
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Ingår i: 2024 2ND INTERNATIONAL CONFERENCE ON UNMANNED VEHICLE SYSTEMS-OMAN, UVS. - : IEEE. - 9798350372557 - 9798350372564
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Konferensbidrag (refereegranskat)abstract
- The US FAA regulations and regulations from other global Civil Aviation Authorities impose significant limitations on secure Broadcast Remote ID strategies for Unmanned Aircraft Systems (UAS). One of the most challenging constraints is configuring messaging within Bluetooth 4 broadcast frames, seemingly limiting the capacity for a reliable Remote ID and trust in UAS communications. However, the Internet Engineering Task Force (IETF) Drone Remote ID Protocol (DRIP) workgroup has adeptly navigated these constraints. They have developed a provably secure Remote ID that authenticates all its messages and can be independently validated without needing an external, internet-based verification service. Remarkably, they achieve this within the stringent message length confines set by Broadcast Remote ID regulations and American Society for Testing and Materials (ASTM) standards. This novel solution, the DRIP Entity Tag (DET), doubles as a legitimate yet non-routable IPv6 address. Beyond its primary application, the DET has promising potential for adoption in broader mobile device ecosystems, fostering interdevice trust. In this paper, we explain the DRIP initiative and its implementation in real-world scenarios and examine its potential use on various mobile devices.
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| 9. |
- Mu, W. H., et al.
(författare)
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Photoperiod drives cessation of wood formation in northern conifers
- 2023
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 32:4, s. 603-617
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Tidskriftsartikel (refereegranskat)abstract
- AimsShifts in xylem phenology directly determine the forest capacity for carbon sequestration. However, a systematic understanding of the spatial patterns and the underpinning drivers in determining the cessation of wood formation (C-cw) is lacking at a pan-continental scale. Here, we addressed this knowledge gap by compiling a new dataset of multiple xylem phenology timings for northern conifers. LocationsSixty-two study sites, Northern Hemisphere (25-55 degrees N). Time period2003-2018 (16 years). TaxaThirty-three conifer species. MethodsA generalized additive model was fitted to characterize the latitudinal pattern in C-cw. Structural equation modelling and a linear mixed-effects model were applied to determine the main drivers underlying the latitudinal pattern in C-cw. ResultsThe C-cw followed a flat S-shaped pattern with increasing latitude. Photoperiod was the dominant determinant of the latitudinal pattern of C-cw, and a longer photoperiod was associated with an earlier C-cw. Both mean growing-season temperature and total growing-season precipitation exhibited significantly positive relationships to the cessation of cell elongation and thus the C-cw across all study sites. In arid regions, the pre-growing-season temperature had a significantly negative effect on C-cw. In humid regions, C-cw was negatively affected by the mean growing-season temperature. The onset of wood formation showed significantly positive coupling with C-cw at arid sites but not at humid sites. Early successional species were sensitive to hydrothermal variations during the pre-growing season. Main conclusionsWe reveal the dominant role of photoperiod in determining the cessation of wood formation for northern conifers and highlight differentiated interactive effects between photoperiod and seasonal climatic factors and the preceding xylem phenophases in determining C-cw among ecoregions and tree species. These insights provide evidence to reduce uncertainty in prediction of the forest carbon uptake potential and the consequent biophysical feedbacks of northern forests.
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| 10. |
- Reid, J M, et al.
(författare)
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Inbreeding effects on immune response in free-living song sparrows (Melospiza melodia)
- 2007
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 274:1610, s. 697-706
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Tidskriftsartikel (refereegranskat)abstract
- The consequences of inbreeding for host immunity to parasitic infection have broad implications for the evolutionary and dynamical impacts of parasites on populations where inbreeding occurs. To rigorously assess the magnitude and the prevalence of inbreeding effects on immunity, multiple components of host immune response should be related to inbreeding coefficient (f) in free-living individuals. We used a pedigreed, free-living population of song sparrows (Melospiza melodia) to test whether individual responses to widely used experimental immune challenges varied consistently with f. The patagial swelling response to phytohaemagglutinin declined markedly with f in both females and males in both 2002 and 2003, although overall inbreeding depression was greater in males. The primary antibody response to tetanus toxoid declined with f in females but not in males in both 2004 and 2005. Primary antibody responses to diphtheria toxoid were low but tended to decline with f in 2004. Overall inbreeding depression did not solely reflect particularly strong immune responses in outbred offspring of immigrant-native pairings or weak responses in highly inbred individuals. These data indicate substantial and apparently sex-specific inbreeding effects on immune response, implying that inbred hosts may be relatively susceptible to parasitic infection to differing degrees in males and females.
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