Kapearailotekniikan käyttö jauhekaarihitsauksessa

Diplomityössä tavoitteena oli tutkia kapearailojauhekaaritekniikan soveltuvuutta konepajakäyttöön ja sen vaikutusta hitsauksen tuottavuuteen sekä hitsin mekaanisiin ominaisuuksiin. Työ tehtiin vertailukokeilla, jossa koehitsaukset suoritettiin eri aineenpaksuuksille siten, että jokaiselle tutkimuksen kohteena olleelle materiaalille tehtiin yksi hitsaus käytössä olevalla jauhekaaritekniikalla, jolloin saatiin vertailukohde, johon uutta kapearailotekniikkaa verrattiin. Tulokset osoittivat, että kapearailotekniikalla 1 palko/palkokerros aineenpaksuudeltaan Pl. 60 mm koekappale saatiin hitsattua n. 39 % nopeammin verrattuna perinteiseen tandem -hitsaukseen. Kyseisellä aineenpaksuudella lisäainelangan kulutus oli n. 41 % ja jauheen kulutus n. 71 % pienempi verrattuna perinteiseen X- railohitsaukseen tandem -menetelmällä. Lisäksi tuli esille, että ”palkoa palonpäälle” -tekniikka on kapearailotekniikoista tehokkain, sillä 2 palkoa/palkokerros menetelmässä railon leveyttä jouduttiin leventämään, jolloin kapearailotekniikan pieni railotilavuus menetettiin. Lisäaineen kulutus tälläkin menetelmällä jäi pienemmäksi verrattuna X- railohitsaukseen. Ennalta pelättyä kuonan irtoamisongelmaa ei kapearailohitsauksessa havaittu, vaan kuona irtosi ongelmitta railon kyljistä. Lisäksi kapearailotekniikalla hitsattujen hitsien lujuudet olivat vertailukelpoiset tandem- ja yksilankamenetelmällä hitsattujen hitsien kanssa.

Falling behind : the growing income gap in America : Democratic staff study of the Joint Economic Committee, Congress of the United States.

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Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 3-Hole 4.5 mm locking compression plate and 3-hole 4.5 mm narrow dynamic compression plate, with two transarticular 5.5 mm cortex screws

Objectives To compare the biomechanical characteristics of 2 arthrodesis techniques for the equine proximal interphalangeal joint (PIP) using either a 3-hole 4.5 mm locking compression plate (LCP) or 3-hole 4.5 mm narrow dynamic compression plate (DCP), both with 2 transarticular 5.5 mm cortex screws. Study Design Experimental. Sample Population Cadaveric adult equine forelimbs (*n=6 pairs). Methods For each forelimb pair, 1 limb was randomly assigned to 1 of 2 treatment groups and the contralateral limb by default to the other treatment group. Construct stiffness, gap formation across the PIP joint, and rotation about the PIP joint were determined for each construct before cyclic axial loading and after each of four, 5000 cycle loading regimens. After the 20,000 cycle axial loading regimen, each construct was loaded to failure. Results There were no significant differences in construct stiffness, gap formation, or sagittal plane rotation between the LCP and DCP treatment groups at any of the measured time points. Conclusion Biomechanically, fixation of the equine PIP joint with a 3-hole 4.5 mm LCP is equivalent to fixation with a 3-hole 4.5 mm narrow DCP under the test conditions used.

Temporomandibular Joint Ankylosis in an Infant: A Rare Cause of Difficult Airway

1.Pre-assessment data of the patient A 2-year-old boy, weighing 15 kg was admitted with a history of limited mouth opening(inter-incisor distance of 6 mm), hypoplastic and retrognathic mandible (bird face deformity) and facial asymmetry from left temporomandibular joint ankylosis (TMJA). He was born at term, after an uneventful pregnancy, and there was no report of trauma during caesarean section. No other possible aetiologies were identified. He was scheduled for mandibular osteotomy. Preoperative ENT examination revealed adenotonsillar hypertrophy. 2. Anaesthetic Plan A fiberoptic nasal intubation was performed under deep inhalation anaesthesia with sevoflurane, with the patient breathing spontaneously. Midazolam (0.05 mg.kg-1) and alfentanil (0.03 mg.kg-1) were given and anaesthesia was maintained with O2/air and sevoflurane. No neuromuscular blocking agent was administered since the surgical team needed facial nerve monitoring. 3. Description of incident During surgery an accidental extubation occurred and an attempt was made to reintubate the trachea by direct laryngoscopy. Although the osteotomy was nearly completed, the vocal cords could not be visualized (Cormack-Lehane grade IV laryngoscopic view). 4. Solving the problem Re-intubation was finally accomplished with the flexible fiberscope and the procedure was concluded without any more incidents. Extubation was performed 24 hours postoperatively with the patient fully awake. After surgery mouth opening improved to inter-incisor gap of 15 mm. 5. Lessons learned and take home message Two airways issues present in this case can lead to difficultventilation and intubation: TMJA and adenotonsillar hypertrophy. These difficulties were anticipated and managed accordingly. The accidental extubation brought to our attention the fact that, even after surgical correction, this airway remains challenging. Even with intensive jaw stretchingexercises there is a high incidence of re-ankylosis, especially in younger patients. One should bear that in mind when anaesthetizing patients with TMJA.

Joint Experimental and Theoretical Analysis of Order Disorder Effects in Cubic BaZrO(3) Assembled Nanoparticles under Decaoctahedral Shape

Periodic first-principles calculations based on density functional theory at the B3LYP level has been carried out to investigate the photoluminescence (PL) emission of BaZrO(3) assembled nanoparticles at room temperature. The defect created in the nanocrystals and their resultant electronic features lead to a diversification of electronic recombination within the BaZrO(3) band gap. Its optical phenomena are discussed in the light of photoluminescence emission at the green-yellow region around 570 nm. The theoretical model for displaced atoms and/or angular changes leads to the breaking of the local symmetry, which is based on the refined structure provided by Rietveld methodology. For each situation a band structure, charge mapping, and density of states were built and analyzed. X-ray diffraction (XRD) patterns, UV-vis measurements, and field emission scanning electron microscopy (FE-SEM) images are essential for a full evaluation of the crystal structure and morphology.

Joint Experimental and Theoretical Analysis of Order Disorder Effects in Cubic BaZrO3 Assembled Nanoparticles under Decaoctahedral Shape

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A joint experimental and theoretical study on the electronic structure and photoluminescence properties of Al-2(WO4)(3) powders

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Approximate Analytical Model for the Squeeze-Film Lubrication of the Human Ankle Joint with Synovial Fluid Filtrated by Articular Cartilage

The aim of this article is to propose an analytical approximate squeeze-film lubrication model of the human ankle joint for a quick assessment of the synovial pressure field and the load carrying due to the squeeze motion. The model starts from the theory of boosted lubrication for the human articular joints lubrication (Walker et al., Rheum Dis 27:512–520, 1968; Maroudas, Lubrication and wear in joints. Sector, London, 1969) and takes into account the fluid transport across the articular cartilage using Darcy’s equation to depict the synovial fluid motion through a porous cartilage matrix. The human ankle joint is assumed to be cylindrical enabling motion in the sagittal plane only. The proposed model is based on a modified Reynolds equation; its integration allows to obtain a quick assessment on the synovial pressure field showing a good agreement with those obtained numerically (Hlavacek, J Biomech 33:1415–1422, 2000). The analytical integration allows the closed form description of the synovial fluid film force and the calculation of the unsteady gap thickness.

Antecedents and consequences of market orientation : an examination in the joint ventures' relational context

Market oriented behaviours have been found to be important predictors of business success across a wide array of studies. Despite their potential importance, research into market oriented behaviours in the joint venture (JV) context is very scarce. This study represents a novel attempt to address this gap by examining a set of antecedent factors which arises from sources outside a traditional firm’s boundary. An extensive review and synthesis of the market orientation and JV literature yielded a set of context-specific antecedent factors relevant to the JV’s relational context. In accordance with the perspective offered by the transaction cost theory, a system of hypotheses about the effects of these antecedent factors on JV’s market oriented behaviours was developed. In order to test these hypotheses, empirical evidence was collected by means of a mail survey to international joint ventures operating in the coastal regions of mainland China. A sample of 191 JV firms was collected as a result. Following well established procedures for scale development and purification as recommended in the methodology literature, the scales were critically trimmed and reviewed for their psychometric properties. The conceptual model was tested with a structural equation model. Results suggested that a number of context-specific antecedents are in fact important determinants of JVs’ level of market oriented behaviours. In addition, the linkage between market oriented behaviours and market performance was also successfully established.

Bridging the gap? Corruption, knowledge and foreign ownership

We argue that in addition to host corruption per se, as accounted for by the existing literature, an explanation of inter-country variation in FDI needs to account for the distance between the host and home corruption, which we call relative corruption. We use a large matched home-host firm-level panel data-set for 1998-2006 from CEE transition countries. Year-specific selectivity corrected estimates suggest that, ceteris paribus, higher relative ‘grand’ corruption lowers foreign ownership as the returns to investment tends to be lower in more corrupt environment. However, after controlling for the selectivity bias, knowledge-intensive parent firms are found to hold controlling ownership, as the difficulty of successful joint venture looms large in more corrupt environment. Results are robust to alternative specifications.

15-deoxy-Δ12,14-prostaglandin J2 Reduces Albumin-induced Arthritis In Temporomandibular Joint Of Rats.

The aim of this study was to evaluate the peripheral effect of 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) in albumin-induced arthritis in temporomandibular joint (TMJ) of rats. Antigen-induced arthritis (AIA) was generated in rats with methylated bovine serum albumin (mBSA) diluted in complete Freund׳s adjuvant. Pretreatment with an intra-articular injection of 15d-PGJ2 (100 ng/TMJ) before mBSA intra-articular injection (10 µg/TMJ) (challenge) in immunized rats significantly reduced the albumin-induced arthritis inflammation. The results demonstrated that 15d-PGJ2 was able to inhibit plasma extravasation, leukocyte migration and the release of inflammatory cytokines IL-6, IL-12, IL-18 and the chemokine CINC-1 in the TMJ tissues. In addition, 15d-PGJ2 was able to increase the expression of the anti-adhesive molecule CD55 and the anti-inflammatory cytokine IL-10. Taken together, it is possible to suggest that 15d-PGJ2 inhibit leukocyte infiltration and subsequently inflammatory process, through a shift in the balance of the pro- and anti-adhesive properties. Thus, 15d-PGJ2 might be used as a potential anti-inflammatory drug to treat arthritis-induced inflammation of the temporomandibular joint.

Gonadal Hormones Modulate The Responsiveness To Local β-blocker-induced Antinociception In The Temporomandibular Joint Of Male And Female Rats.

We have previously demonstrated that blockade of β-adrenoreceptors (β-AR) located in the temporomandibular joint (TMJ) of rats suppresses formalin-induced TMJ nociceptive behaviour in both male and female rats, but female rats are more responsive. In this study, we investigated whether gonadal hormones modulate the responsiveness to local β-blocker-induced antinociception in the TMJ of rats. Co-administration of each of the selective β1 (atenolol), β2 (ICI 118.551) and β3 (SR59230A)-AR antagonists with equi-nociceptive concentrations of formalin in the TMJ of intact, gonadectomized and hormone-treated gonadectomized male and female rats. Atenolol, ICI 118.551 and SR59230A significantly reduced formalin-induced TMJ nociception in a dose response fashion in all groups tested. However, a lower dose of each β-AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and testosterone-treated gonadectomized male rats. In the female groups, a lower dose of β1 -AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact or gonadectomized rats treated with progesterone or a high dose of oestradiol; a lower dose of β2 -AR antagonist was sufficient to significantly reduce nociceptive responses in gonadectomized but not in intact and gonadectomized rats treated with low or high dose of oestradiol. Gonadal hormones may reduce the responsiveness to local β-blocker-induced antinociception in the TMJ of male and female rats. However, their effect depends upon their plasma level, the subtype of β-AR and the dose of β-blockers used.

Characterization Of Cumulative Joint Damage Patterns In Patients With Rheumatoid Arthritis: A Clinical, Serological, And Gene Polymorphism Perspective.

To characterize cumulative joint damage (CJD) patterns in rheumatoid arthritis (RA) and determine their associations with demographic/clinical features and HLA-DRB1 gene polymorphism. Hand and foot radiographs were obtained from 404 patients with RA. CJD patterns were determined by 3 derivations from Sharp/van der Heijde scores, obtained by the mathematical division of scores for hands/feet (Sharp-h/f score), fingers/wrists (Sharp-f/w score), and erosion/space narrowing (Sharp-e/sn score), respectively. DNA and serum were obtained for determination of HLA-DRB1 polymorphism, rheumatoid factor (RF), and anticitrullinated protein antibodies (ACPA). Patients with wrist-dominant CJD pattern were more likely to have severe RA than those with finger-dominant pattern (68.4% vs 46.0%; p = 0.036) as were those with foot-dominant vs hand-dominant CJD pattern (76.5% vs 56.4%; p = 0.044). HLA-DRB1 shared epitope (SE) alleles were associated with erosion-dominant CJD pattern (p = 0.021). Patients with erosion-dominant CJD pattern had higher levels of RF and ACPA than those with space-narrowing-dominant CJD pattern (median RF 71.35 U/ml vs 22.05 U/ml, respectively; p = 0.003; median ACPA 187.9 U/ml vs 143.2 U/ml, respectively; p < 0.001). The majority of triple-positive patients (SE+, RF+, ACPA+) had erosion-dominant CJD pattern (62.3%) while the majority of triple-negative patients (SE-, FR-, ACPA-) had space narrowing-dominant CJD pattern (75%; p = 0.017). ACPA was associated with HLA-DRB1 SE alleles (p < 0.05). Patients with foot-dominant CJD pattern were taller than those with hand-dominant CJD pattern (p = 0.002); those with erosion-dominant CJD pattern had higher weight and body mass index than those with space narrowing-dominant CJD pattern (p = 0.014, p = 0.001). CJD patterns were associated with disease severity, HLA-DRB1 SE status, presence and titer of ACPA and RF, and morphometric features.

Osteochondroma of the temporomandibular joint: a case report

Osteochondroma of the mandibular condyle has been found in the oral and maxillofacial region rarely. This paper describes a case of osteochondroma of the mandibular condyle in a 20-year-old woman, who was referred to our service with facial asymmetry, prognathic deviation of chin, cross-bite to the contralateral side, changes in condylar morphology, limited mouth opening, and malocclusion. Computed tomography (CT) was performed for better evaluation to the pathological conditions on the temporomandibular joint. Based on the clinical examination, patient history, and complementary exams, the hypothesis of osteochondroma was established. Condylectomy was performed using a preauricular approach with total removal of the lesion. After 3 years of postoperative follow up and orthodontic therapy, the patient is symptom-free, and has normal mouth opening with no deviation in the opening pattern.

Juvenile idiopathic arthritis with involvement of the temporomandibular joint: the role of image examinations

PURPOSE: Juvenile idiopathic arthritis (JIA) has unknown etiology, and the involvement of the temporomandibular joint (TMJ) is rare in the early phase of the disease. The present article describes the use of computed tomography (CT) and magnetic resonance (MRI) images for the diagnosis of affected TMJ in JIA. CASE DESCRIPTION: A 12-year-old, female, Caucasian patient, with systemic rheumathoid arthritis and involvement of multiple joints was referred to the Imaging Center for TMJ assessment. The patient reported TMJ pain and limited opening of the mouth. The helical CT examination of the TMJ region showed asymmetric mandibular condyles, erosion of the right condyle and osteophyte-like formation. The MRI examination showed erosion of the right mandibular condyle, osteophytes, displacement without reduction and disruption of the articular disc. CONCLUSION: The disorders of the TMJ as a consequence of JIA must be carefully assessed by modern imaging methods such as CT and MRI. CT is very useful for the evaluation of discrete bone changes, which are not identified by conventional radiographs in the early phase of JIA. MRI allows the evaluation of soft tissues, the identification of acute articular inflammation and the differentiation between pannus and synovial hypertrophy.