A Comparison of the Oxidation and Nitridation Properties of Selected Chromia- and Alumina-Forming Alloys at 800 degrees C

Three FeCrAl alloys and two chromia-formers (a stainless steel, and a Ni-base alloy) have been exposed in four environments (dry air, air + 20% H2O, 20% H-2 + 20% H2O + Ar and 95% N-2 + 5% H-2) for 168 h at 800 degrees C. The corroded samples were investigated by SEM/EDS, XRD and gravimetry, and the formation of CrO2(OH)(2)(g) was measured as a function of time using a denuder technique. The Fe-base alloy formed a Cr-rich protective oxide scale in dry air and wet air but suffered break-away oxidation in 20% H-2 + 20% H2O + Ar. In contrast, the Ni-base alloy suffered extensive NiO formation and internal oxidation in dry air and wet air but formed a protective chromia scale in 20% H-2 + 20% H2O. All three FeCrAl alloys formed protective alumina scales in dry air, wet air and 20% H-2 + 20% H2O + Ar. The FeCrAl alloy Kanthal APMT was severely nitrided in the 95% N-2 + 5% H-2 environment due to defects in the oxide scale associated with RE-rich inclusions which allowed nitrogen to enter the alloy. In contrast, the two Cr-lean FeCrAl alloys Kanthal EF101 and Kanthal EF100 did not suffer nitridation at all

Exploring the Effect of Silicon on the High Temperature Corrosion of Lean FeCrAl Alloys in Humid Air

A new approach to reduce the chromium and aluminium concentrations in FeCrAl alloys without significantly impairing corrosion resistance is to alloy with 1-2 wt.% silicon. This paper investigates the "silicon effect" on oxidation by comparing the oxidation behavior and scale microstructure of two FeCrAl alloys, one alloyed with silicon and the other not, in dry and wet air at 600 degrees C and 800 degrees C. Both alloys formed thin protective oxide scales and the Cr-evaporation rates were small. In wet air at 800 degrees C the Si-alloyed FeCrAl formed an oxide scale containing mullite and tridymite together with alpha- and gamma-alumina. It is suggested that the reported improvement of the corrosion resistance of Al- and Cr-lean FeCrAl\u27s by silicon alloying is caused by the appearance of Si-rich phases in the scale

Efficacy of an external chromia layer in reducing nitridation of high temperature alloys

Six high temperature alloys have been exposed in N2/H2 environments at 900 \ub0C. In order to study the efficacy of a chromia barrier layer against nitrogen ingress, experiments were performed in two environments having the same N2/H2 ratio but slightly different water content, chromia formation being spontaneous in one case only. The samples were evaluated by SEM/STEM/EDX, XRD, gravimetry and GD-OES. The presence of an external chromia scale reduced nitridation of the alloy by 50–95%. Furthermore, in the presence of a continuous alumina layer no nitridation of the alloy was detected

Tanezumab: a selective humanized mAb for chronic lower back pain

Chronic lower back pain is a significant disease that affects nearly 20% of the worldwide population. Along with hindering patients’ quality of life, chronic lower back pain is considered to be the second most common cause of disability among Americans. Treating chronic lower back pain is often a challenge for providers, especially in light of our current opioid epidemic. With this epidemic and an increased aging population, there is an imminent need for development of new pharmacologic therapeutic options, which are not only effective but also pose minimal adverse effects to the patient. With these considerations, a novel therapeutic agent called tanezumab has been developed and studied. Tanezumab is a humanized monoclonal immunoglobulin G2 antibody that works by inhibiting the binding of NGF to its receptors. NGF is involved in the function of sensory neurons and fibers involved in nociceptive transduction. It is commonly seen in excess in inflammatory joint conditions and in chronic pain patients. Nociceptors are dependent on NGF for growth and ongoing function. The inhibition of NGF binding to its receptors is a mechanism by which pain pathways can be interrupted. In this article, a number of recent randomized controlled trials are examined relating to the efficacy and safety of tanezumab in the treatment of chronic lower back pain. Although tanezumab was shown to be an effective pain modulator in major trials, several adverse effects were seen among different doses of the medication, one of which led to a clinical hold placed by the US Food and Drug Administration. In summary, tanezumab is a promising agent that warrants further investigation into its analgesic properties and safety profile

Responsible, Safe, and Effective Use of Biologics in the Management of Low Back Pain: American Society of Interventional Pain Physicians (ASIPP) Guidelines

BACKGROUND: Regenerative medicine is a medical subspecialty that seeks to recruit and enhance the body\u27s own inherent healing armamentarium in the treatment of patient pathology. This therapy\u27s intention is to assist in the repair, and to potentially replace or restore damaged tissue through the use of autologous or allogenic biologics. This field is rising like a Phoenix from the ashes of underperforming conventional therapy midst the hopes and high expectations of patients and medical personnel alike. But, because this is a relatively new area of medicine that has yet to substantiate its outcomes, care must be taken in its public presentation and promises as well as in its use. OBJECTIVE: To provide guidance for the responsible, safe, and effective use of biologic therapy in the lumbar spine. To present a template on which to build standardized therapies using biologics. To ground potential administrators of biologics in the knowledge of the current outcome statistics and to stimulate those interested in providing biologic therapy to participate in high quality research that will ultimately promote and further advance this area of medicine. METHODS: The methodology used has included the development of objectives and key questions. A panel of experts from various medical specialties and subspecialties as well as differing regions collaborated in the formation of these guidelines and submitted (if any) their appropriate disclosures of conflicts of interest. Trustworthy standards were employed in the creation of these guidelines. The literature pertaining to regenerative medicine, its effectiveness, and adverse consequences was thoroughly reviewed using a best evidence synthesis of the available literature. The grading for recommendation was provided as described by the Agency for Healthcare Research and Quality (AHRQ). SUMMARY OF EVIDENCE: Lumbar Disc Injections: Based on the available evidence regarding the use of platelet-rich plasma (PRP), including one high-quality randomized controlled trial (RCT), multiple moderate-quality observational studies, a single-arm meta-analysis and evidence from a systematic review, the qualitative evidence has been assessed as Level III (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best-evidence synthesis. Based on the available evidence regarding the use of medicinal signaling/ mesenchymal stem cell (MSCs) with a high-quality RCT, multiple moderate-quality observational studies, a single-arm meta-analysis, and 2 systematic reviews, the qualitative evidence has been assessed as Level III (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Lumbar Epidural Injections Based on one high-quality RCT, multiple relevant moderate-quality observational studies and a single-arm meta-analysis, the qualitative evidence has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Lumbar Facet Joint Injections Based on one high-quality RCT and 2 moderate-quality observational studies, the qualitative evidence for facet joint injections with PRP has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Sacroiliac Joint Injection Based on one high-quality RCT, one moderate-quality observational study, and one low-quality case report, the qualitative evidence has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. CONCLUSION: Based on the evidence synthesis summarized above, there is Level III evidence for intradiscal injections of PRP and MSCs, whereas the evidence is considered Level IV for lumbar facet joint, lumbar epidural, and sacroiliac joint injections of PRP, (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis.Regenerative therapy should be provided to patients following diagnostic evidence of a need for biologic therapy, following a thorough discussion of the patient\u27s needs and expectations, after properly educating the patient on the use and administration of biologics and in full light of the patient\u27s medical history. Regenerative therapy may be provided independently or in conjunction with other modalities of treatment including a structured exercise program, physical therapy, behavioral therapy, and along with the appropriate conventional medical therapy as necessary. Appropriate precautions should be taken into consideration and followed prior to performing biologic therapy. Multiple guidelines from the Food and Drug Administration (FDA), potential limitations in the use of biologic therapy and the appropriate requirements for compliance with the FDA have been detailed in these guidelines. KEY WORDS: Regenerative medicine, platelet-rich plasma, medicinal signaling cells, mesenchymal stem cells, stromal vascular fraction, bone marrow concentrate, chronic low back pain, discogenic pain, facet joint pain, Food and Drug Administration, minimal manipulation, evidence synthesis

Uses for virtual reality in the early stages of the product development process for modular products

There is an ongoing technological shift with electromobility, automation and connectivity, which affects the development of heavy vehicles such as excavators, wheel loaders and pavers. These vehicles can be referred to as cyber-physical systems (CPS). The development entails changes for companies' product development, which leads to higher complexity which is a challenge to manage. To develop heavy cyber-physical vehicles, the company uses an X-methodology in the product development process (referred to as X by confidentiality). The challenge for the company is to develop the X-methodology to combine systematic working methods where modularization and Virtual Reality (VR) are combined in early phases of product development. The purpose of this thesis was to develop the company's work processes in the early phases of product development utilizing modularization with the support of VR. This is to find improvement potential in their existing modularization methodology to achieve improved efficiency and complexity management in the product development process. To answer this, two research questions were formed: RQ1: What can modularization combined with VR be used for in early phases of product development? RQ2: How can the development of a modular cyber-physical subsystem be improved with the help of VR in the early phases of the product development process? Due to the lack of VR in the early phases of product development in the X-methodology, a literature study and a case study were conducted around a specific subsystem. The early phases of the company correspond to the literature’s Planning- and Concept Development phase. For this study, interviews, internal documents, and physical artifacts were used as empirical evidence and then compared with the found literature. In the analysis of data, it was noted that the literature's findings estimated a reduction of 50% of the product development time, a time reduction of 65% in sketch production and a 95% cost reduction for prototypes. The data found in the case study argued that lead times and costs for prototypes in scale 1:1 can be reduced with the help of virtual prototypes. The reduction in lead times was 95–97.5% of the current value, while the cost reduction was 100% for virtual prototypes in 1:1 scale compared to physical prototypes in 1:1 scale. Limited to the case study’s subsystem, it was estimated that it is possible to reduce physical location required for reviewing the subsystems, reach infinite workspace, increase visibility of the product architecture, allow more degrees of freedom for interaction with the subsystems, and infinite size scale. The study's data for research question 1 suggest that the combination between VR and modularization forms a synergic improvement of the early phases in the product development process. VR supports complexity reduction by evaluating the modularization. VR has the ability in early phases to reduce costs and time. This is achieved by working with VR early on with cross-functional feedback together with virtual models that reflects the final product. The study's data for research question 2 suggest that VR has the potential to improve the product development of modular cyber-physical systems by reducing time and costs, as well as providing access to reference architecture. With delimitation to a subsystem and its variants, it was demonstrated that VR can reduce the physical space required for prototypes and facilitate/ease visualization and interaction with the prototypes.Det pågår ett teknikskifte med elektromobilitet, automation och uppkoppling vilket påverkar utvecklingen av tunga fordon så som grävmaskiner, hjullastare och asfaltläggare. Dessa fordon kan benämnas som cyberfysiska system (CPS). Utvecklingen medför förändringar för företagens produktutveckling vilket leder till högre komplexitet som är en utmaning att hantera. För att utveckla tunga cyberfysiska fordon använder företaget en X-metodik i produktutvecklingsprocessen (benämns X av sekretess). Utmaningen för företaget är att utveckla X-metodiken för att kombinera systematiska arbetssätt där modularisering och Virtuell Verklighet (VR) kombineras i tidiga faser av produktutveckling. Syftet med detta examensarbete var att utveckla företagets arbetsprocesser i tidiga faser av produktutveckling gällande modularisering med stöd av VR. Detta för att finna förbättringspotential i deras befintliga modulariseringsmetodik för att nå en förbättrad effektivitet och komplexitetshantering i produktutvecklingsprocessen. Specifikt kommer dessa forskningsfrågor att undersökas: FF1: Vad kan modularisering kombinerat med VR användas för i tidiga faser av produktutvecklingen? FF2: Hur kan utvecklingen av ett modulärt cyberfysiskt delsystem förbättras med hjälp av VR i tidiga faser av produktutvecklingsprocessen? På grund av avsaknaden av VR i tidiga faser av produktutvecklingen i X-metodiken genomfördes en litteraturstudie och en empirisk fallstudie kring ett avgränsat delsystem. Företagets tidiga faser motsvarar litteraturens Planering- och Konceptutveckling-faser. Till denna studie användes intervjuer, interna dokument och fysiska artefakter som empiri och jämfördes med den funna litteraturen. I analysen av all data framkom det att litteraturens fynd uppskattade en reduktion med 50% av produktutvecklingstiden, en tidreduktion med 65% i skissframtagning och 95% kostnadsreduktion för prototyper. Fallstudien menade att ledtider och kostnader för prototyper i skala 1:1 kan reduceras med hjälp av virtuella prototyper. Reduktionen av ledtider var 95–97,5% av det nuvarande värdet, medan kostnadsreduktionen var 100% för virtuella prototyper i skala 1:1 jämfört med fysiska prototyper i skala 1:1. Avgränsat till fallstudiens delsystem uppskattades en reducerad fysisk plats som krävs för granskning av delsystemen, oändlig arbetsyta, ökad synlighet för produktarkitekturen, fler frihetsgrader för interaktion med delsystemen och oändlig storleksskala. Slutsats till forskningsfråga 1 från studiens data var att kombinationen mellan VR och modularisering bildar en synergi för en förbättring av tidiga faser i produktutvecklingsprocessen. VR stödjer komplexitetreduktion vid utvärdering av modularisering. VR har möjlighet i tidiga faser att reducera kostnader och tid. Vilket grundar sig att jobba tidigt med VR för tvärfunktionell feedback tillsammans med virtuella modeller som återspeglar slutprodukten. Studiens data till forskningsfråga 2 föreslår att VR har möjligheten att förbättra produktutvecklingen av modulära cyberfysiska system genom att reducera tid och kostnader samt ge tillgång till referensarkitektur. Med avgränsning till ett delsystem och dess varianter påvisades det att VR kan reducera fysiskt utrymme som krävs för prototyper och underlätta visualisering samt interaktion med dem.

Uses for virtual reality in the early stages of the product development process for modular products

There is an ongoing technological shift with electromobility, automation and connectivity, which affects the development of heavy vehicles such as excavators, wheel loaders and pavers. These vehicles can be referred to as cyber-physical systems (CPS). The development entails changes for companies' product development, which leads to higher complexity which is a challenge to manage. To develop heavy cyber-physical vehicles, the company uses an X-methodology in the product development process (referred to as X by confidentiality). The challenge for the company is to develop the X-methodology to combine systematic working methods where modularization and Virtual Reality (VR) are combined in early phases of product development. The purpose of this thesis was to develop the company's work processes in the early phases of product development utilizing modularization with the support of VR. This is to find improvement potential in their existing modularization methodology to achieve improved efficiency and complexity management in the product development process. To answer this, two research questions were formed: RQ1: What can modularization combined with VR be used for in early phases of product development? RQ2: How can the development of a modular cyber-physical subsystem be improved with the help of VR in the early phases of the product development process? Due to the lack of VR in the early phases of product development in the X-methodology, a literature study and a case study were conducted around a specific subsystem. The early phases of the company correspond to the literature’s Planning- and Concept Development phase. For this study, interviews, internal documents, and physical artifacts were used as empirical evidence and then compared with the found literature. In the analysis of data, it was noted that the literature's findings estimated a reduction of 50% of the product development time, a time reduction of 65% in sketch production and a 95% cost reduction for prototypes. The data found in the case study argued that lead times and costs for prototypes in scale 1:1 can be reduced with the help of virtual prototypes. The reduction in lead times was 95–97.5% of the current value, while the cost reduction was 100% for virtual prototypes in 1:1 scale compared to physical prototypes in 1:1 scale. Limited to the case study’s subsystem, it was estimated that it is possible to reduce physical location required for reviewing the subsystems, reach infinite workspace, increase visibility of the product architecture, allow more degrees of freedom for interaction with the subsystems, and infinite size scale. The study's data for research question 1 suggest that the combination between VR and modularization forms a synergic improvement of the early phases in the product development process. VR supports complexity reduction by evaluating the modularization. VR has the ability in early phases to reduce costs and time. This is achieved by working with VR early on with cross-functional feedback together with virtual models that reflects the final product. The study's data for research question 2 suggest that VR has the potential to improve the product development of modular cyber-physical systems by reducing time and costs, as well as providing access to reference architecture. With delimitation to a subsystem and its variants, it was demonstrated that VR can reduce the physical space required for prototypes and facilitate/ease visualization and interaction with the prototypes.Det pågår ett teknikskifte med elektromobilitet, automation och uppkoppling vilket påverkar utvecklingen av tunga fordon så som grävmaskiner, hjullastare och asfaltläggare. Dessa fordon kan benämnas som cyberfysiska system (CPS). Utvecklingen medför förändringar för företagens produktutveckling vilket leder till högre komplexitet som är en utmaning att hantera. För att utveckla tunga cyberfysiska fordon använder företaget en X-metodik i produktutvecklingsprocessen (benämns X av sekretess). Utmaningen för företaget är att utveckla X-metodiken för att kombinera systematiska arbetssätt där modularisering och Virtuell Verklighet (VR) kombineras i tidiga faser av produktutveckling. Syftet med detta examensarbete var att utveckla företagets arbetsprocesser i tidiga faser av produktutveckling gällande modularisering med stöd av VR. Detta för att finna förbättringspotential i deras befintliga modulariseringsmetodik för att nå en förbättrad effektivitet och komplexitetshantering i produktutvecklingsprocessen. Specifikt kommer dessa forskningsfrågor att undersökas: FF1: Vad kan modularisering kombinerat med VR användas för i tidiga faser av produktutvecklingen? FF2: Hur kan utvecklingen av ett modulärt cyberfysiskt delsystem förbättras med hjälp av VR i tidiga faser av produktutvecklingsprocessen? På grund av avsaknaden av VR i tidiga faser av produktutvecklingen i X-metodiken genomfördes en litteraturstudie och en empirisk fallstudie kring ett avgränsat delsystem. Företagets tidiga faser motsvarar litteraturens Planering- och Konceptutveckling-faser. Till denna studie användes intervjuer, interna dokument och fysiska artefakter som empiri och jämfördes med den funna litteraturen. I analysen av all data framkom det att litteraturens fynd uppskattade en reduktion med 50% av produktutvecklingstiden, en tidreduktion med 65% i skissframtagning och 95% kostnadsreduktion för prototyper. Fallstudien menade att ledtider och kostnader för prototyper i skala 1:1 kan reduceras med hjälp av virtuella prototyper. Reduktionen av ledtider var 95–97,5% av det nuvarande värdet, medan kostnadsreduktionen var 100% för virtuella prototyper i skala 1:1 jämfört med fysiska prototyper i skala 1:1. Avgränsat till fallstudiens delsystem uppskattades en reducerad fysisk plats som krävs för granskning av delsystemen, oändlig arbetsyta, ökad synlighet för produktarkitekturen, fler frihetsgrader för interaktion med delsystemen och oändlig storleksskala. Slutsats till forskningsfråga 1 från studiens data var att kombinationen mellan VR och modularisering bildar en synergi för en förbättring av tidiga faser i produktutvecklingsprocessen. VR stödjer komplexitetreduktion vid utvärdering av modularisering. VR har möjlighet i tidiga faser att reducera kostnader och tid. Vilket grundar sig att jobba tidigt med VR för tvärfunktionell feedback tillsammans med virtuella modeller som återspeglar slutprodukten. Studiens data till forskningsfråga 2 föreslår att VR har möjligheten att förbättra produktutvecklingen av modulära cyberfysiska system genom att reducera tid och kostnader samt ge tillgång till referensarkitektur. Med avgränsning till ett delsystem och dess varianter påvisades det att VR kan reducera fysiskt utrymme som krävs för prototyper och underlätta visualisering samt interaktion med dem.

Ungas organisering och politiska deltagande : En kunskapsöversikt

Medborgarnas frivilliga deltagande i politiken uppfattas som centralt för en levande demokrati. Baserat på fler än 300 färska studier visar den här rapporten att ungas politiska deltagande blivit allt svårare att definiera och avgränsa. Ett skäl är att ungdomar hela tiden utvecklar nya vägar för att försöka påverka, som reaktion på sociala, samhälleliga, teknologiska och politiska förändringar. Ett annat är att vissa handlingar motiveras av traditionella medborgarplikter, medan andra utformas mer utifrån en strävan efter ett individualiserat och uttrycksfullt självförverkligande

How to handle boil-off gases from LNG trucks

This master thesis project aims to investigate the circumstances of boil-off for heavy vehicle transports, using LNG as fuel, and suggest possible ways of handling these gases otherwise released into the atmosphere. LNG, Liquefied Natural Gas, is when natural gas is cooled below its vaporisation point, turning it into liquid phase which is a much more dense way of storing and transporting the fuel. Trucks running on LNG store their fuel in super insulated tanks, but some heat are transferred to the fuel anyway, causing it to vaporise at a steady rate. During driving of these trucks, this vaporised gas is consumed and the pressure are kept at a certain level of 10 bar. Once the truck is turned off, consumption stops and the pressure starts to increase. After a period of standstill, normally several days, the pressure within the tank has increased to 16 bar where a valve opens to release gas from the tank. This is a safety feature, causing the pressure not to increase further creating hazards. While natural gas, mostly containing methane, is released, fuel is lost and an environmentally unfriendly substance is let out into the atmosphere. This should be avoided, to improve the environmental aspects of using LNG as a fuel for trucks, which most likely will be regulated by laws yet to come. Since the release of boil-off gases rarely should happen during the regular use of these trucks, but a system handling these gases should work at any time and place, a cheap and lightweight unit are to be fitted to these trucks. Equipment already on the truck should be used as much as possible, keeping additional costs and weight low. The only practical way of storing this gas, which is the most resource efficient way of handling these boil-off gases, is to re-liquefy it and transferring it back to the usual LNG tank on the vehicle. The second best option is to consume the gas, making it less environmentally unfriendly. While consuming the gas, as much as possible of its energy should be utilised as electricity and heat. Preferably, electricity should be produced as much as possible, charging the batteries on the truck, decreasing the fuel consumption while running and increasing the lifespan of the batteries. The most efficient way of managing the heat generated is to distribute it to the coolant system on the truck, providing it to the engine and several other components. Distributing the energy is also a matter of safety, as very hot areas otherwise might cause risks of fire. The most simple concept, that is easiest to implement in the near future, is to use a burner similar to the auxiliary diesel heaters fitted to some trucks today. This consumes fuel, generating heat to the coolant system. An additional cooler is needed, to cool of excess heat from the system keeping the temperatures to a certain level. Using this system for an extensive period of time needs an external power supply, since no electricity is generated from consuming the gas. Other technologies that could be used in the future, also generating electricity, is thermoelectric generators and solid oxide fuel cells. These are technologies now being further developed and adapted to the industry of vehicles. These technologies are especially interesting when they are implemented to these trucks for use within other systems as well, for instance utilisation of the heat within exhaust gases. A small scale re-liquefaction unit mounted to the truck is however seen as the most resource efficient solution, making it possible to keep using the gas for it intended purpose of propelling the trucks forward. This technology has to be made more compact, adapting it to the use on a truck