bluuebunny/crossref_metadata_2025 huggingface dataset:
Built-Up Cold-Formed Steel Beams with Corrugated Webs Connected with Spot Welding
Authors: Benzar Ştefan , Ungureanu Viorel , Dubină Dan , Burca Mircea
Published: July 2015

Corrugated web girders emerged in the past two decades. Their main advantages consists in the possibility to use slender webs avoiding the risk of premature local buckling. Consequently, higher moment capacity might be obtained increasing the beam depth with really thin webs, which are stiffened by the corrugations. Increased interest for this solution was observed for the main frames of single-storey steel buildings and steel bridges. A new solution was proposed at the Politehnica University of Timisoara, in which the beam is composed by a web of trapezoidal steel sheet and flanges of back-to-back lipped channel steel sections. This solution uses self-drilling screws for connecting flanges to the web and to ensure the continuity of the web as seam fasteners. Starting from this new technological solution the paper extends and investigates the use of spot welding as seam fastening to build the web, in order to increase the degree of automation of fabrication. Experimental work of specimens in shear having two or three layers of steel sheets connected by spot welding will be presented. The results will be implemented on a numerical model in order to study the behaviour of the beams presented above.
Pre-Cambering in Steel and Composite Bridge Structures
Authors: Petzek Edward , Meteş Elena , Grecea Daniel , Băncilă Radu
Published: July 2015

Steel beams are used in the construction of industrial, commercial buildings, bridges and other structures. Deflection in steel and composite beams describes the amount of deformation the beam will incur under the design loads. Pre-cambering reduces the deflection under the loads, being one of the requirements of deflection checking. For usual simple supported girders the problem is relatively simple, more complex is the pre-cambering problem at continuous and frame structures, especially in bridges where different construction phases and also positions of the convoy have to be considered. The present paper describes the calculus of the deflection and the necessity of pre-cambering in structural elements including a case study: a railway composite integral bridge.
Effect of Corrosion and Cracks at the Historical Steel Bridges
Authors: Feier Anamaria
Published: July 2015

Most of the historical steel bridges are still original and have presented a number of defects (strong corrosion, fatigue material). These fractures may be conceptually explained by the presence of irregularities along the elements, the rusted surface that may act as crack initiators and precipitate crack propagation throughout the section.
Damage of Reinforced Concrete Structures due to Steel Corrosion
Authors: Sosdean Corina , Marsavina Liviu , de Schutter Geert
Published: July 2015

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.
Improving a Brazed Joint Structure, with a New Ecological Brass
Authors: Verbiţchi Victor , Botila Lia-Nicoleta , Ciucă Cristian , Kostov Ana , Milosavljević Aleksandra , Todorović Radiša
Published: July 2015

In the frame of the Romania-Republic of Serbia IPA Cross-border Cooperation Programme, in the Project Ecosolder, the National Research & Development Institute for Welding and Material Testing - ISIM Timisoara, Romania, has elaborated a brazing procedure with a new ecological brass of the type B-Cu60ZnSnSiMn, elaborated by the Mining and Metallurgy Institute - MMI Bor, Serbia. The brazing test was carried out according to the standard EN 13134:2000 related to the brazing procedure approval. The applied process is oxygen-acetylene flame brazing of steel sheets, with the sizes of 87 mm x 80 mm, thickness of 1.0 mm and overlap 7 mm. Images of the execution of the brazing procedure are presented, with comments on every phase. The appearance of the joint is adequate, by the visual examination. By the metallographic analysis, the constituents of the deposited filler metal are dendritic solid solution, with fine particles of Sn, Si and Mn. No defects have been revealed. The values of the hardness are 91-133 HV1. The results of the specific shear test comply with the requirements. The technological, ecological, structural and mechanical characteristics of this filler alloy are adequate. Some applications of brazing with the new ecological brass are recommended.
Investigation of a Camshaft Repaired by Welding Using the Vibration Signal Analysis
Authors: Bereteu Liviu , Crâştiu Ion , Nyaguly Eva , Simoiu Dorin
Published: July 2015

Metallic materials are subjected to degradation mechanisms when working in corrosive environments, such as those created by mineral oils and residues of a motor fuel. The camshaft is subjected to multiaxial stresses, creep, fatigue, corrosion and abrasion. As a result of the operation in special conditions of high temperature and high pressure can lead to forming cracks, damages or failure. In such cases it is necessary for these components to be repaired by welding, followed by a rectification process. This paper presents a method for determining the quality of welding repairs and rectification results from the analysis of vibration signals. A Fast Fourier Transform algorithm and an algorithm based on Prony's series method are used for processing the sampled signals.
Shear Strength Variation for PLmT Welded Zn Coated Advanced High Strength Steels Used in Automotive Structures in Overlap Configuration
Authors: Bîrdeanu Aurel Valentin
Published: July 2015

The paper presents the results of applying of a new hybrid welding process, i.e. Pulsed LASER-(micro)TIG (PLmT), for realizing overlap joints for Zn-coated U/AHSS thin sheets materials, used in the automotive industry for realizing car structures.
The statistical influence onto the joint’s shear strength (objective function) of three hybrid welding process parameters was investigated by means of experimental design and weighted. The influence of laser pulse peak power, the average welding TIG current and the laser pulse duration was investigated for two types of Zn coated U/AHSS used in car body realization.
The results revealed that the new process can be applied for the investigated materials and that joints with appropriate shear strength values can be obtained.
Each combination did behave rather different in respect to the investigated process parameters and the results did reveal that rather strong interactions are in place between the influence factors (IF) for CPW 800 material. The determined models can be used to select convenient process parameters combinations in respect to minimum Zn coating damage and proper shear strength of the joints for each of the studied materials.
Structural Hardening of Excavator Teeth Used in Exploitation of Magmatic Rocks
Authors: Pascu Romulus , Buzdugan Ramona Monica , Bîrdeanu Aurel Valentin , Tihanov Daniel , Binchiciu Emilia Florina
Published: July 2015

The teeth of specialized excavators used in exploitation of magmatic rocks are made by forging from alloyed steels having 3.4%Mn, and the value of hardness less than 38HRC. The usual working time is about 15,000 hours.This paper estimates the possibility to make a structural hardening of the excavator teeth using the deposition by welding of hard layers. These hard layers are obtained by using the electrodes type Cr-W-V-Ti, having the hardness between 48 and 50HRC. In these conditions, the austenitic hard structures with complex carbides of W, V, Ti are developed.The presence of the hard layers on the active surfaces of teeth, deposited using an homologated technology, will allow to increase the life time of these components with minimum 30% in usually working conditions.
Chemical Active Coated Rods Used for Brazing
Authors: Binchiciu Emilia Florina , Fleșer Traian , Voiculescu Ionelia
Published: July 2015

Brazing copper or copper-steel structures imposes measurements regarding deposits and base materials, and regarding the gas content, hydrogen and oxygen, that comes from the deoxidizing coat. The deoxidizing coat is made out of complex salts, hydroxides and acids with high hygroscopicity. Research effected in order to improve the deoxidizer capacity of the coat and to reduce its hygroscopicity, taking into account the ratio at coating of the rods, has highlighted the possibility of equipping the material with powders that have chemical active proprieties for deoxidizing processes at brazing. To this end we developed the pre-alloy type 48%Cu–47%Sn–4%P–1%Si, powder, grain size 0,05mm. The product was used, with a participation of 8% of the total coating mass, at manufacturing by extrusion of the new rods for brazing copper semi-products. We executed and characterized deep joints type copper-copper and copper-stainless steel.Brazing process results, have appreciated, detected by melted metal deposition tests, moistening angle and respectively of the mechanical characteristics of the achieved joints.Results have confirmed the above mentioned hypothesis; it highlighted superior values to those obtained with classic rods, at technical and technological proprieties.
Case Study on Failures of Thermoplastics Pipeline Systems
Authors: Cocard Marius , Murariu Alin Constantin , Moldovan Emil , Burian Claudiu
Published: July 2015

The paper presents some of the most significant situations of tests realised on high density polyethylene pipeline networks from Romania, designed for fluids and gases, which failed during 2008-2014. The inspected objects were assemblies or welded components made of pipes and fittings, as parts of the natural gas and potable water pipeline. The inspections on various assemblies and weldments have identified a number of nonconformities, which have led to failures, generally recorded after welding, during operation. Based on the investigation results, a number of comments and recommendations have emerged, useful for manufacturing companies and for the clients, which could ensue increasing the safety in operation of the high density polyethylene pipeline systems.
Structural Analysis for Joining Dissimilar Thin Sheets with CMT (Cold Metal Transfer) Process
Authors: Muncut Elena , Perianu Ion Aurel , Glavan Dan , Sima Gheorghe
Published: July 2015

The work includes work steps for joining thin sheets with a thickness ranging from1.0 mm (according to EN10327-2004). The study presents the following steps: problems arising from joining with CMT weld-brazing process of galvanized low-carbon steel sheets, used as filler material CuSi3. This is due to the fact that copper induces: grain refinement by lowering the transformation temperature and precipitation hardening after rapid cooling and tempering the theoretical and experimental study of these problems leads to the possibility of combining copper with iron. This is an experiment to investigate the formation of interlayer containing intermetallic compounds, inter layer located between the molten material and the base material. An important part of the study was the optimizing of weld-brazing parameters: welding current, welding speed and dynamic correction factor Ina.Keywords: galvanized sheets steel, joining, weld-brazing CMT, preserving the zinc layer, intermetallic layer.
The Influence of the Path of Corner Gussets Weld Seam over the Stress Concentration Factors of the Tubular T Joints
Authors: Dima Gabriel , Balcu Ion
Published: July 2015

The joints of the tubular welded structures are stiffened with gussets in order to decrease the stress concentration factors and to increase the rigidity. The experience from field concluded that the tangent placed gussets bring the biggest improvement to the fatigue and dynamic behaviour as well as the weight saving of joints. The path of the weld seam influences the stress distribution in the joint members, gusset and in the weld itself. The paper proposes different types of weld ending path to investigate the changes in the stress distribution in all components of the joint. Using the FE analysis, the stress concentration factors were determined in three load cases. Both the numerical and preliminary experimental results indicated different joint behaviours according to the loading type. An assessment of the proposed weld paths was done, together with FE model approach and design recommendations.
Physical and Geometrical Quality of X2CrNi18-9 Stainless Steel Surfaces Cut with Abrasive Waterjet - Work Hardening of Marginal Layer
Authors: Perianu Ion Aurel , Mitelea Ion , Şerban Viorel Aurel
Published: July 2015

This study presents investigations regarding processing X2CrNi18-9 stainless steel sheet with 2 mm thickness using abrasive waterjet cutting.By variation of base technological parameters (water pressure, travelling speed, abrasive rate and focusing tube inner diameter) the shape together with size of the kerf were analyzed.Roughness measurements from the entrance to exit of cut surfaces in correlation with the analysis carried out using an optical microscope highlights work hardening of the marginal layer. This phenomenon is less accentuated in the higher area which is in the vicinity of the focusing tube and intensifies towards the lower area of cut material.
Nondestructive Method for the Determination of the Elastic Properties of Welded Aluminum Plates
Authors: Perescu Alexandru , Bereteu Liviu , Simoiu Dorin , Nyaguly Eva
Published: July 2015

The development of modern technologies requires new materials and technologies prepared for specific technical applications. Aluminum is one of these materials, it can be welded and anodized, which gives them anticorrosive characteristics. The determination of mechanical properties (Young’s modulus and shear modulus) is of great importance from both scientific and practical points of view. Most of the known methods for determination of the Young’s modulus and shear modulus are sample destructive and base on measuring a force (energy) necessary for break the sample. This paper presents a nondestructive method for the determination of the elastic properties of welded aluminum plates by vibration tests and laser measurements using Doppler velocimeter. A Fast Fourier Transform algorithm is used for processing the sampled signals.
Investigation on the Flash Butt Welding of 51CrV4 Steels for Saw Blades
Authors: Bodea Marius , Sechel Argentina Niculina , Popa Florin
Published: July 2015

The band saw steel must present a good balance between strength, toughness and materials elasticity in the weld joint, respectively in the HAZ. Those areas are affected by the heat welding cycle that is changing the material microstructure and consequently the overall mechanical properties of the saw blade. Minor changes in the chemical compositions of the saw blade material, in welding parameters or in the post-welding treatment can cause semnificative changes in the saw blade durability and performance. A SMEs from Cluj-Napoca had encountered a problem after the welding operation of the 51CrV4 QT steels, bought from two different European manufacturers. It was observed a different welding behavior for the same steel bought from one of the steel manufacturer compared to the other one. The SMEs requested a study in order to find out what went wrong during welding operation, because the bending test has shown an insufficient toughness in the welded joint. As result, we have conducted a research in the quest of the causes for the embrittlement phenomena observed in the welded joint. Chemical analysis, mechanical testing, SEM and EDX and XRD analysis have been used to investigate the material properties in the parent material, weld and HAZ.
Effect of Heat Treatment on the Surfaces Topography Tested at the Cavitation Erosion from Steel 16MnCr5
Authors: Ghera Cristian , Mitelea Ion , Bordeasu Ilare , Crăciunescu Corneliu Marius
Published: July 2015

This paper analyzes, by comparison, the changes appeared in surface topography, for 16MnCr5 steel tested at cavitation erosion, subjected to different type of the heat treatments.
The purpose of research, aimed at establishing a correlation between resistance to cavitation erosions and the surface roughness parameters, for various types of heat treatment (annealing, carburizing, Duplex treatment of carburizing, followed by the surface hardening by induction).
Cavitation tests were conducted on a vibrator device with piezoceramic crystals, which fully complies with the requirements imposed by the ASTM G32 - 2010.
Roughness parameters were measured using a Mitutoyo apparatus.
Influence of some Oxide Coating Layers on the Mechanical Properties of Steel Plates
Authors: Bereteu Liviu , Vodă Mircea , Pascu Romulus , Nyaguly Eva
Published: July 2015

The paper presents a vibroacoustic method to determining the stiffness of coated steel with various materials such as metal oxides, metallic paints, polymers etc and Young's modulus for coating materials. The method consists in measuring the dynamic response of the steel in the form of a rectangular bar subjected to external impulse. One of the latest non-destructive experimental techniques in this field is based on the analysis of vibrating signal response recorded with a condenser microphone. A Fast Fourier Transform algorithm is used for processing the sampled signals. Knowing the mechanical properties of steel plates prior to coating with metal oxides, and determining the same properties after coating, can be obtained the mechanical properties of metal oxides and their influence on the properties of the ensemble.
Circulating Human CD27−IgA+ Memory B Cells Recognize Bacteria with Polyreactive Igs
Authors: Berkowska Magdalena A. , Schickel Jean-Nicolas , Grosserichter-Wagener Christina , de Ridder Dick , Ng Yen Shing , van Dongen Jacques J. M. , Meffre Eric , van Zelm Menno C.
Published: July 2015

The vast majority of IgA production occurs in mucosal tissue following T cell–dependent and T cell–independent Ag responses. To study the nature of each of these responses, we analyzed the gene-expression and Ig-reactivity profiles of T cell–dependent CD27+IgA+ and T cell–independent CD27−IgA+ circulating memory B cells. Gene-expression profiles of IgA+ subsets were highly similar to each other and to IgG+ memory B cell subsets, with typical upregulation of activation markers and downregulation of inhibitory receptors. However, we identified the mucosa-associated CCR9 and RUNX2 genes to be specifically upregulated in CD27−IgA+ B cells. We also found that CD27−IgA+ B cells expressed Abs with distinct Ig repertoire and reactivity compared with those from CD27+IgA+ B cells. Indeed, Abs from CD27−IgA+ B cells were weakly mutated, often used Igλ chain, and were enriched in polyreactive clones recognizing various bacterial species. Hence, T cell–independent IgA responses are likely involved in the maintenance of gut homeostasis through the production of polyreactive mutated IgA Abs with cross-reactive anti-commensal reactivity.
Antigenic Stimulation of Kv1.3-Deficient Th Cells Gives Rise to a Population of Foxp3-Independent T Cells with Suppressive Properties
Authors: Grishkan Inna V. , Tosi Dominique M. , Bowman Melissa D. , Harary Maya , Calabresi Peter A. , Gocke Anne R.
Published: July 2015

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the CNS that has been linked with defects in regulatory T cell function. Therefore, strategies to selectively target pathogenic cells via enhanced regulatory T cell activity may provide therapeutic benefit. Kv1.3 is a voltage-gated potassium channel expressed on myelin-reactive T cells from MS patients. Kv1.3-knockout (KO) mice are protected from experimental autoimmune encephalomyelitis, an animal model of MS, and Kv1.3-KO Th cells display suppressive capacity associated with increased IL-10. In this article, we demonstrate that myelin oligodendrocyte glycoprotein–specific Kv1.3-KO Th cells exhibit a unique regulatory phenotype characterized by high CD25, CTLA4, pSTAT5, FoxO1, and GATA1 expression without a corresponding increase in Foxp3. These phenotypic changes result from increased signaling through IL-2R. Moreover, myelin oligodendrocyte glycoprotein–specific Kv1.3-KO Th cells can ameliorate experimental autoimmune encephalomyelitis following transfer to wild-type recipients in a manner that is partially dependent on IL-2R and STAT5 signaling. The present study identifies a population of Foxp3− T cells with suppressive properties that arises in the absence of Kv1.3 and enhances the understanding of the molecular mechanism by which these cells are generated. This increased understanding could contribute to the development of novel therapies for MS patients that promote heightened immune regulation.
Incremental detection of pulmonary tuberculosis among presumptive patients by GeneXpert MTB/RIF® over fluorescent microscopy in Mwanza, Tanzania: an operational study
Authors: Seni Jeremiah , Kidenya Benson R. , Anga Mercy , Kapesa Anthony , Meda John R. , Mutakyawa Richard , Mkomwa Zahra H. , Marcel Fidelis , Changalucha John M. , Mshana Stephen E.
Published: July 2015

Laboratory confirmation among presumptive tuberculosis (PTB) patients is pivotal in ensuring prompt management. Limited information exists in Tanzania regarding the performance of GeneXpert MTB/RIF® in comparison with conventional methods. An operational study was conducted involving 806 PTB patients at Sekou Toure Hospital in Mwanza, Tanzania from June to November 2013. Patients’ information was obtained and their respective sputum samples analyzed by lightemitting diode fluorescent microscopy (LED FM) and GeneXpert MTB/RIF®. The mean age of study participants was 39.6±16.0 years, with males accounting for 50.5%. The majority of patients (97.5%) were new cases. The proportions of PTB patients confirmed by LED FM and GeneXpert MTB/RIF® were 14.1% (114/806) and 23.7% (191/806) respectively, resulting into a 9.6% incremental detection rate by GeneXpert MTB/RIF® over LED FM. The detection rate among HIV positive individuals was also higher [23.6% (63/267) vs 14.2% (38/267), respectively], with an incremental detection of 9.4%. The incremental detection of PTB by GeneXpert MTB/RIF® over LED FM calls for expansion of its use to increase detection of smear negative PTB among people living with HIV.
Effect of five desiccants applied alone and in combination with glyphosate in dry edible bean (Phaseolus vulgaris L.)
Authors: McNaughton Kristen E. , Blackshaw Robert E. , Waddell Kristine A. , Gulden Robert H. , Sikkema Peter H. , Gillard Chris L.
Published: July 2015

McNaughton, K. E., Blackshaw, R. E., Waddell, K. A., Gulden, R. H., Sikkema, P. H. and Gillard, C. L. 2015. Effect of five desiccants applied alone and in combination with glyphosate in dry edible bean (Phaseolus vulgaris L.). Can. J. Plant Sci. 95: 1235–1242. Application of dry bean desiccants just prior to crop maturity is common practice by Canadian producers. As dry beans are grown for human consumption it is critical that producers pick desiccants that do not affect crop yield, seed quality, or result in desiccant seed residue levels above accepted levels. In this study the efficacy of glyphosate, diquat, glufosinate, carfentrazone, flumioxazin, and saflufenacil as desiccants was examined for navy, cranberry, pinto, and great northern dry bean. Seed herbicide residues were also tested for each of the dry bean classes tested. Navy, cranberry, pinto, and great northern dry bean yields were not impacted by use of the desiccants diquat, carfentrazone, flumioxazin, or saflufenacil when applied at labelled rates and application timings. Additionally, herbicide residues in seed following application remained lower than maximum residue limits (MRL) established by primary Canadian dry bean export partners. Generally, dry bean colour, irrespective of class, was not altered by desiccant use; diquat and flumioxazin caused minor increases in the degree of red and yellow seed pigmentation for cranberry bean only. Although colour differences were noted using a Chroma meter the differences were slight and would not likely be of economic importance. Application of glyphosate did not affect crop yield, and seed residue levels were below MRLs for navy, pinto, and great northern bean. However, seed glyphosate residue levels were above the MRL for cranberry bean when glyphosate was applied alone or tankmixed with carfentrazone, flumioxazin, or saflufenacil. Seed residue levels were also above listed MRLs for some export countries when glufosinate was applied to navy, cranberry, and pinto bean, although crop yield and seed quality remained unaffected. These findings suggest that growers and contractors should avoid using glufosinate as a dry bean desiccant at least for some markets and that care should be taken when selecting glyphosate as a desiccant, especially for cranberry bean. Across all market classes desiccation progress of bean leaf, stem, and pod tissue was slowest when glyphosate and carfentrazone were used.
Quantifying herbicide dose–response and resistance in Echinochloa spp. by measuring root length in growth pouches
Authors: Zhang C. J. , Lim S. H. , Kim J. W. , Song J. S. , Yook M. J. , Nah G. , Valverde B. E. , Kim D. S.
Published: July 2015

Zhang, C. J., Lim, S. H., Kim, J. W., Song, J. S., Yook, M. J., Nah, G., Valverde, N. E. and Kim, D. S. 2015. Quantifying herbicide dose–response and resistance in Echinochloa spp. by measuring root length in growth pouches. Can. J. Plant Sci. 95: 1181–1192. The aim of the presented study was to develop a bioassay for rapid diagnosis of herbicide dose–response and resistance in Echinochloa. Pre-germinated seeds of Echinochloa spp. were incubated in growth pouches (18 cm×16.5 cm) containing herbicide solutions in a range of concentrations. Shoot and root lengths were measured after 6 d of incubation. Dose–responses estimated by measuring root lengths in the growth pouches were well-described by the log-logistic dose–response model and similar to those estimated by a whole-plant assay. Accurate dose–response curves were successfully generated for several herbicides with different modes of action, suggesting that the growth pouch method can be used for herbicide bioassays. The suitability of the growth pouch method for rapid diagnosis of acetyl coenzyme-A carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor resistance in Echinochloa spp. was also tested. For cyhalofop-butyl, resistant and susceptible biotypes were discriminated at 180–300 mg a.i. L−1 and 80–120 mg a.i. L−1 for barnyardgrass (E. crus-galli) and late watergrass (E. oryzicola), respectively. For penoxsulam, the discriminatory dosage was 350–500 mg a.i. L−1 for barnyardgrass and 650–1000 mg a.i. L−1 for late watergrass. The method was further used to identify late watergrass biotypes resistant and susceptible to two other ALS inhibitors, azimsulfuron and bispyribac-sodium. Our results show that the growth pouch method can be reliably used in herbicide dose–response studies and to diagnose herbicide resistance in Echinochloa spp., with significant time and cost savings compared with conventional whole-plant assays.
Unicompartmental Arthroplasty of the knee
Authors: Varghese Mathew , Chakrabarty Gautam , Thambapillay Sivaharan
Published: July 2015

Unicompartmental knee arthroplasty (UKA) is now well-established as a treatment option for isolated compartment osteoarthritis (OA) of the knee. Improvements in surgical technique, instrumentation, component design, and rapid rehabilitation has resulted good long-term survivorship and in the wider acceptance for UKA. The experiences from several centers have been key in the education of surgeons with regards to patient selection, technical considerations, and importantly avoiding common pitfalls can lead to early failure of the components. A younger patient may require revision in their lifetime, but modern UKA design allows this to be performed with minimal surgical difficulties and with good outcome.

How to cite this article

Chakrabarty G, Varghese M, Thambapillay S. Unicompartmental Arthroplasty of the knee. J Postgrad Med Edu Res 2015;49(2):74-78.
Dual Ectopic Thyroid: An Uncommon Imaging Diagnosis
Authors: Khandelwal Niranjan , Prabhakar Nidhi , Gupta Vivek , Panda Naresh
Published: July 2015

Ectopic thyroid means presence of thyroid gland tissue in abnormal position. Dual ectopic thyroid is the presence of thyroid gland tissue in two different abnormal locations. It is a rare entity. We report a case of 17-year-old girl who presented with a gradually increasing swelling in the upper neck. Her thyroid tests were abnormal, with mildly reduced T3 and T4 levels and increased TSH levels. Ultrasound revealed an isoechoic homogenous lesion in the intermuscular planes, in the infrahyoid neck. Contrast-enhanced computed tomography (CECT) of neck was performed which showed two similarly homogenously enhancing lesions, one in the base of tongue and another in the infrahyoid neck. Thyroid gland was not seen in its normal location. On the basis of these findings, diagnosis of dual ectopic thyroid was made. Patient was managed with thyroid hormone replacement therapy to manage hypothyroidism and decrease the size of swelling.

How to cite this article

Prabhakar N, Gupta V, Panda N, Khandelwal N. Dual Ectopic Thyroid: An Uncommon Imaging Diagnosis. J Postgrad Med Edu Res 2015;49(2):83-84.
Successful Treatment of a Complicated Case of Neuroleptic Malignant Syndrome with a Higher Dose of Bromocriptine and Lorazepam
Authors: Kashyap Rajesh , Kashyap Ravi
Published: July 2015

A 53-year-old patient of schizoaffective disorder developed neuroleptic malignant syndrome (NMS) following treatment with haloperidol, clozapine and parenteral fluphenazine. He showed full recovery with immediate discontinuation of potential offenders and prompt treatment with a higher dose of bromocriptine and lorazepam along with management of aspiration pneumonia. Need for early recognition of NMS and treatment by a multidisciplinary team is discussed.

How to cite this article

Sharma R, Kashyap R. Successful Treatment of a Complicated Case of Neuroleptic Malignant Syndrome with a Higher Dose of Bromocriptine and Lorazepam. J Postgrad Med Edu Res 2015;49(2):88-90.
Role of Perioperative Echocardiography Leadership in a Tertiary University Hospital
Authors: Subramaniam Balachundhur
Published: July 2015

Echocardiography has been shown to improve the perioperative outcomes of surgical and critically ill patients. Several modalities of echocardiography (transthoracic, transesophageal, epicardial and epiaortic) are being utilized clinically for the hemodynamic management of surgical patients. They can be collectively described as perioperative echocardiography (PEC). Because of such a wider scope of practice in perioperative echocardiography, there is a need for leadership to maintain equipment, good clinical practice, education, research, quality, documentation, billing and reimbursement. American Society of Echocardiography (ASE) and Society of Cardiovascular Anesthesiologists (SCA) published guidelines for performance, reporting, education and quality improvement in PEC. The major role of echocardiography leadership is to ensure PEC team follows the guidelines published by ASE/SCA in their practice and utilize the potential of the various modalities to the benefit and safety of their patients. This article explores the key roles of the director for perioperative echocardiography service at a tertiary university hospital.

How to cite this article

Subramaniam K, Subramaniam B. Role of Perioperative Echocardiography Leadership in a Tertiary University Hospital. J Perioper Echocardiogr 2015;3(1):4-16.
Unanticipated Ruptured Sinus of Valsalva Aneurysm in a Patient with Subpulmonic Ventricular Septum Defect: Suspected by Intraoperative Transthoracic Echo; Confirmed by Intraoperative Transesophageal Echo
Authors: Raj Ravi , Bhat Imran Hussain
Published: July 2015

A sinus of valsalva (SOV) aneurysm is a rare cardiac anomaly that may be congenital or acquired and may be associated with other cardiac lesions. If the aneurysm ruptures, it causes acute symptoms of dyspnea. Echocardiography is a useful diagnostic tool that can guide in proper management of these patients. We present a case of subpulmonic ventricular septal defect (VSD) in which ruptured SOV was detected by intraoperative transthoracic echocardiography and confirmed by transesophageal echocardiography (TEE) which helped in adequate surgical repair and good outcome for the patient. This case report emphasizes the importance of routine transthoracic and TEE in operating room by cardiac anesthesiologist to confirm the original diagnosis and look for new unanticipated findings, especially in a patient with strong clinical suspicion.

How to cite this article

Bhat IH, Raj R, Puri GD. Unanticipated Ruptured Sinus of Valsalva Aneurysm in a Patient with Subpulmonic Ventricular Septum Defect: Suspected by Intraoperative Transthoracic Echo; Confirmed by Intraoperative Transesophageal Echo. J Perioper Echocardiogr 2015;3(1): 25-28.
Role of Transesophageal Echocardiography in Detection of Residual Tumor in Renal Cell Carcinoma Extending into Right Atrium
Authors: Madhavan, Sethu , Mohan Ravi
Published: July 2015

Renal cell carcinoma (RCC) has a tendency to invade inferior vena cava and thereby reach the right heart. This may necessitate a combined surgical procedure. These procedures impose a challenge to the anesthesiologist and may require the use of veno-venous or cardiopulmonary bypass (CPB). Among the serious and feared complication is embolization of the thrombus during mobilization of the tumor causing a massive pulmonary embolism. Transesophageal echocardiography (TEE) not only provide accurate identification and definition of the cranial extent of the tumor, but may also provide continuous monitoring of the hemodynamic status and cardiac complications during surgical manipulation of tumor. In this case report, we have described TEE helped in recognizing not only the extent of the tumor but also (the adequacy of removal of the tumor thrombus) diagnose the residual tumor after removal during right radical nephrectomy.

How to cite this article

Negi SL, Dutta V, Puri GD, Madhavan S, Mohan R. Role of Transesophageal Echocardiography in Detection of Residual Thrombus in Renal Cell Carcinoma extending into Right Atrium. J Perioper Echocardiogr 2015;3(1):35-38.
Multinational versus National Firms on Capital Adjustment Costs: A Structural Approach
Authors: Lapatinas Athanasios
Published: July 2015

This paper provides an alternative perspective on the firm-level empirical analysis of the relation between foreign ownership and capital demand adjustment in host countries. The author estimates a dynamic structural model of investment on a sample of 4672 Belgian firms for the period 2003-2010, permitting him to distinguish the ‘ownership status’ of firms. He considers a dynamic discrete choice model of a general specification of adjustment costs including convex and non-convex components. The author uses the method of simulated moments in order to estimate the structural parameters. His results indicate that multinationals’ affiliates face lower capital adjustment costs than national firms.
Reducing Severance Costs or Subsidizing Permanent Job Creation: Which Policy Is More Effective to Reduce Duality?
Authors: Osuna Victoria
Published: July 2015

This paper introduces endogenous on-the-job training in the job creation and destruction model of the search and matching type by García-Pérez and Osuna (Dual labour markets and the tenure distribution: Reducing severance pay or introducing a single contract, 2014). The objective is to compare the effects of subsidizing permanent job creation with that of reducing the severance cost gap between permanent contracts (PCs) and temporary contracts (TCs) as a strategy to reduce labour market duality between PCs and TCs. The 2006 and 2012 Spanish labour market reforms are used as a benchmark. The results point to fact that subsidizing permanent job creation may not be the best option from a fiscal point of view to reduce labour market segmentation between PCs and TCs. In particular, the results of introducing the subsidized “entrepreneurs’ permanent contract” (EPC) in the 2012 labour market reform may have involved substantial deadweight effects. In fact, the reduction of the severance cost gap to a number close to 15 days of wages per year of service (p.y.o.s.) may generate the same effects, provided dismissals for objective reasons are effectively made easier to justify and firms make use of that option instead of agreeing to an indemnity closer to the amount paid for unfair dismissals. Finally, the model also shows the relevance of designing appropriate penalties for those firms that do not comply with the obligations that subsidies involve.
Personal Consumption by Family Type and Household Income
Authors: Krueger Kurt V.
Published: July 2015

Using Consumer Expenditure Survey data, this paper presents a unified approach in estimating adult personal consumption across five family types: married wage earners living together by themselves, married wage earners living together with their minor children, married retirees living together by themselves, single wage earning parents living together with their minor children, and single wage earners living alone. In addition to advancing the literature with a unified analysis of family traits, this paper uses over 700 microdata expenditure classifications instead of the approximate 30 summary expenditure classifications which have been relied on in other personal consumption studies. Microdata expenditure classification reduces problems of allocating expenses among family members. The paper begins with an overview of the Consumer Expenditure Survey, the federal data source that is most appropriate for estimating personal consumption. Next presented are the allocation rules to separate personal from survivor and household expenditures. The data are then identified followed by empirical estimation.
Real Earnings of Full-Time Workers by Education, Age Group and Sex, 1974–2012
Authors: Foster Edward
Published: July 2015

This note rearranges the data from Census Bureau Personal Income (PINC) tables 32–35 showing earnings of full-time, year-round workers from 1974 to 2012 to display the 39-year time series for average real earnings by education, age group, and sex. Aggregated data show strong upward trends for all males and all females combined, for males and females with a bachelor's degree or more and for those with less than a bachelor's degree. However, all trends have flattened or become negative since 2000. Shifts in the composition of the work force over time mean that trends in aggregated earnings incorporate those shifts, so may not be useful for projecting earnings growth for any individual plaintiff of a specific age and educational background. The note addresses that problem in two ways: First it re-weights the aggregate statistics to remove some effects of shifts in composition of the workforce. Second it gives summary statistics for log-linear regressions of real earnings on time for all education-age-sex combinations for the period 1974–1999 and for 2000–2012. Growth for the latter period is negative for most of those combinations. Supplemental material for a Microsoft Excel workbook contains the underlying data and several figures and is accessible from the Journal of Forensic Economics website.
Are Mexican Net Discount Rates Stationary? An Application for Lost Earnings Damages Involving Undocumented Workers
Authors: Avalos Antonio , Alley R. Sean
Published: July 2015

This paper provides empirical evidence on the behavior of various Mexican Net Discount Rates (NDRs) by examining the time series properties of several yields on Mexican government securities and annual wages for nine industrial sectors. Results indicate that NDRs are characterized as a stationary series around a shift in its mean. The forecast for the mean of the NDRs should be based on the period after the time of the shift, which took place in 1994. The discussion addresses relevant case law and the application of the NDR approach to the calculation of damages for Mexican undocumented workers as an effort to equip forensic economists with the tools to conduct such estimates.
Dinitrogen fixation and dissolved organic nitrogen fueled primary production and particulate export during the VAHINE mesocosm experiment (New Caledonia lagoon)
Authors: Berthelot H. , Moutin T. , L'Helguen S. , Leblanc K. , Hélias S. , Grosso O. , Leblond N. , Charrière B. , Bonnet S.
Published: July 2015

Abstract. In the oligotrophic ocean characterized by nitrate (NO3−) depletion in surface waters, dinitrogen (N2) fixation and dissolved organic nitrogen (DON) can represent significant nitrogen (N) sources for the ecosystem. In this study, we deployed large in situ mesocosms in New Caledonia in order to investigate (1) the contribution of N2 fixation and DON use to primary production (PP) and particle export and (2) the fate of the freshly produced particulate organic N (PON), i.e., whether it is preferentially accumulated and recycled in the water column or exported out of the system. The mesocosms were fertilized with phosphate (PO43-) in order to prevent phosphorus (P) limitation and promote N2 fixation. The diazotrophic community was dominated by diatom–diazotroph associations (DDAs) during the first part of the experiment for 10 days (P1) followed by the unicellular N2-fixing cyanobacteria UCYN-C for the last 9 days (P2) of the experiment. N2 fixation rates averaged 9.8 ± 4.0 and 27.7 ± 8.6 nmol L−1 d−1 during P1 and P2, respectively. NO3− concentrations (< 0.04 μmol L−1) in the mesocosms were a negligible source of N, indicating that N2 fixation was the main driver of new production throughout the experiment. The contribution of N2 fixation to PP was not significantly different (p > 0.05) during P1 (9.0 ± 3.3 %) and P2 (12.6 ± 6.1 %). However, the e ratio that quantifies the efficiency of a system to export particulate organic carbon (POCexport) compared to PP (e ratio = POCexport/PP) was significantly higher (p < 0.05) during P2 (39.7 ± 24.9 %) than during P1 (23.9 ± 20.2 %), indicating that the production sustained by UCYN-C was more efficient at promoting C export than the production sustained by DDAs. During P1, PON was stable and the total amount of N provided by N2 fixation (0.10 ± 0.02 μmol L−1) was not significantly different (p > 0.05) from the total amount of PON exported (0.10 ± 0.04 μmol L−1), suggesting a rapid and probably direct export of the recently fixed N2 by the DDAs. During P2, both PON concentrations and PON export increased in the mesocosms by a factor 1.5–2. Unlike in P1, this PON production was not totally explained by the new N provided by N2 fixation. The use of DON, whose concentrations decreased significantly (p < 0.05) from 5.3 ± 0.5 μmol L−1 to 4.4 ± 0.5 μmol L−1, appeared to be the missing N source. The DON consumption (~ 0.9 μmol L−1) during P2 is higher than the total amount of new N brought by N2 fixation (~ 0.25 μmol L−1) during the same period. These results suggest that while DDAs mainly rely on N2 fixation for their N requirements, both N2 fixation and DON can be significant N sources for primary production and particulate export following UCYN-C blooms in the New Caledonia lagoon and by extension in the N-limited oceans where similar events are likely to occur.
Annual litterfall dynamics and nutrient deposition depending on elevation and land use at Mt. Kilimanjaro
Authors: Becker J. , Pabst H. , Mnyonga J. , Kuzyakov Y.
Published: July 2015

Abstract. Litterfall is one of the major pathways connecting above- and belowground processes. The effects of climate and land-use change on carbon (C) and nutrient inputs by litterfall are poorly known. We quantified and analyzed annual patterns of C and nutrient deposition via litterfall in natural forests and agroforestry systems along the unique elevation gradient of Mt. Kilimanjaro. Tree litter in three natural (lower montane, Ocotea and Podocarpus forests), two sustainably used (homegardens) and one intensively managed (shaded coffee plantation) was collected on a biweekly basis from May 2012 to July 2013. Leaves, branches and remaining residues were separated and analyzed for C and nutrient contents. The annual pattern of litterfall was closely related to rainfall seasonality, exhibiting a large peak towards the end of the dry season (August–October). This peak decreased at higher elevations with decreasing rainfall seasonality. Macronutrients (N, P, K) in leaf litter increased at mid elevation (2100 m a.s.l.) and with land-use intensity. Carbon content and micronutrients (Al, Fe, Mn, Na) however, were unaffected or decreased with land-use intensity. On the southern slope of Mt. Kilimanjaro, the annual pattern of litterfall depends on seasonal climatic conditions. While leaf litterfall decreased with elevation, total annual input was independent of climate. Compared to natural forests, the nutrient cycles in agroforestry ecosystems were accelerated by fertilization and the associated changes in dominant tree species.
History of the Munich–Maisach–Fürstenfeldbruck Geomagnetic Observatory
Authors: Soffel H. C.
Published: July 2015

Abstract. The Munich–Maisach–Fürstenfeldbruck Geomagnetic Observatory is one of the observatories with the longest recordings of the geomagnetic field. It started with hourly measurements on 1 August 1840. The founder of the observatory in Munich was Johann von Lamont (1805–1879), the Director of the Royal Bavarian Astronomical Observatory. He had been stimulated to build his own observatory by the initiative of the Göttingen Magnetic Union founded in 1834 by Alexander von Humboldt (1769–1859) and Carl Friedrich Gauss (1777–1855). Before 1840 fewer than five observatories existed; the most prominent ones were those in London and Paris. At the beginning Lamont used equipment delivered by Gauss in Göttingen, but soon started to build instruments of his own design. Among them was a nonmagnetic theodolite which allowed precise geomagnetic measurements to be made also in the field. During the 1850s Lamont carried out geomagnetic surveys and produced geomagnetic maps for Germany and many other European countries. At the end of the nineteenth century accurate geomagnetic measurements in Munich became more and more disturbed by the magnetic stray fields from electric tramways and industry. During this period the quality of the data suffered and the measurements had to be interrupted several times. After a provisional solution in Maisach, a village 25 km west of Munich, a final solution could be found in the vicinity of the nearby city of Fürstenfeldbruck. Here the measurements started again on 1 January 1939. Since the 1980s the observatory has been part of INTERMAGNET, an organization providing almost real-time geomagnetic data of the highest quality.