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Japanese encephalitis virus belongs to the genus Flavivirus. Case fatality averages 30% and almost 50% of the survivors are left with permanent neuropsychiatric sequelae. Japanese encephalitis occurs in nearly all Asian countries including India. Patterns of JE transmission vary within individual countries and from year to year. In endemic areas, sporadic cases occur throughout the year. Japanese encephalitis or AES has been reported from 231 districts of 23 states. The best way to control JE in humans is through vaccination. Currently available vaccines in India are live attenuated, cell culture-derived SA 14-14-2, inactivated SA 14-14-2 vaccine (IC51; IXIARO® by Intercell and JEEV® by Biological Evans India Ltd.) and inactivated Vero cell culture-derived Kolar strain, 821564XY, JE vaccine (JENVAC® by Bharat Biotech). As 2006 position paper of WHO stated that mouse brain derived vaccines should be withdrawn and replaced by newer vaccines due to safety profile and as it is not available in our country now, this vaccine will not be discussed henceforth.

Pleural effusions of diverse aetiologies are encountered in patients with chronic kidney disease (CKD). The objectives of the present study were to examine the frequency of occurrence, causes, clinical features and management strategies of pleural effusion in patients with CKD including renal transplant recipients.A prospective cross-sectional observational analysis of pleural effusion in adult patients with CKD (stages 3 to 5) attending the Departments of Nephrology and Respiratory Medicine of a tertiary care institution in Eastern India was performed over a period of one year (February 2010 to January 2011).Pleural effusion was found in 29 out of 430 patients with CKD (6.7%) and in two out of 34 post-renal transplant recipients (5.9%) evaluated during the study period. The mean age was 37.35 +/- 1.8 (mean +/- SEM [standard error of mean]) with a male to female ratio of 2:1. Exudates and transudates were found in equal frequencies. Heart failure was the single most common cause (41.9%, 13 of 31). Tuberculosis (TB) (n = 8, 25.8%) and uraemic effusions (n = 6, 19.4%) were responsible for the majority of exudates. Unilateral effusion with a normal heart size had a positive predictive value of 83.3% for non-heart failure aetiology.Symptomatic pleural effusion was present in a small proportion of 6.7%; (n = 29) patients with CKD including post-renal transplant recipients. Heart failure, TB and uraemic effusions accounted for most of the cases. Differentiating TB from uraemic effusion requires a combined clinico-pathological approach and this differentiation is absolutely necessary for proper management.

COVID-19 infection and its various signs and symptoms are still causing significant studies across the world. Although relatively less in prevalence and disease severity, children none the less are also affected by this infection. Most of the research in this regard has been focused on the adults, whereas there is a definite lacuna in the published data in the pediatric COVID-19 cases and its prognosis. India being a large country with significant number of population, which has experienced lot of such cases. The present study aims to explore data from 46 patients

ObjectivesThis study aims to describe the demographic and clinical profile and ascertain the determinants of outcome among hospitalized coronavirus disease 2019 (COVID-19) adult patients enrolled in the National Clinical Registry for COVID-19 (NCRC).MethodsNCRC is an on-going data collection platform operational in 42 hospitals across India. Data of hospitalized COVID-19 patients enrolled in NCRC between 1st September 2020 to 26th October 2021 were examined.ResultsAnalysis of 29 509 hospitalized, adult COVID-19 patients [mean (SD) age: 51.1 (16.2) year; male: 18 752 (63.6%)] showed that 15 678 (53.1%) had at least one comorbidity. Among 25 715 (87.1%) symptomatic patients, fever was the commonest symptom (72.3%) followed by shortness of breath (48.9%) and dry cough (45.5%). In-hospital mortality was 14.5% (n = 3957). Adjusted odds of dying were significantly higher in age group ≥60 years, males, with diabetes, chronic kidney diseases, chronic liver disease, malignancy and tuberculosis, presenting with dyspnoea and neurological symptoms. WHO ordinal scale 4 or above at admission carried the highest odds of dying [5.6 (95% CI: 4.6–7.0)]. Patients receiving one [OR: 0.5 (95% CI: 0.4–0.7)] or two doses of anti-SARS CoV-2 vaccine [OR: 0.4 (95% CI: 0.3–0.7)] were protected from in-hospital mortality.ConclusionsWHO ordinal scale at admission is the most important independent predictor for in-hospital death in COVID-19 patients. Anti-SARS-CoV2 vaccination provides significant protection against mortality.

ObjectivesThis study aims to describe the demographic and clinical profile and ascertain the determinants of outcome among hospitalised COVID-19 adult patients enrolled in the National Clinical Registry for COVID-19 (NCRC).MethodsNCRC is an on-going data collection platform operational in 42 hospitals across India. Data of hospitalized COVID-19 patients enrolled in NCRC between 1st September 2020 to 26th October 2021 were examined.ResultsAnalysis of 29,509 hospitalised, adult COVID-19 patients [mean (SD) age: 51.1 (16.2) year; male: 18752 (63.6%)] showed that 15678 (53.1%) had at least one comorbidity. Among 25715 (87.1%) symptomatic patients, fever was the commonest symptom (72.3%) followed by shortness of breath (48.9%) and dry cough (45.5%). In-hospital mortality was 14.5% (n=3957). Adjusted odds of dying were significantly higher in age-group ≥60 years, males, with diabetes, chronic kidney diseases, chronic liver disease, malignancy, and tuberculosis, presenting with dyspnea and neurological symptoms. WHO ordinal scale 4 or above at admission carried the highest odds of dying [5.6 (95% CI: 4.6, 7.0)]. Patients receiving one [OR: 0.5 (95% CI: 0.4, 0.7)] or two doses of anti-SARS CoV-2 vaccine [OR: 0.4 (95% CI: 0.3, 0.7)] were protected from in-hospital mortality.ConclusionsWHO ordinal scale at admission is the most important independent predictor for in-hospital death in COVID-19 patients. Anti-SARS-CoV2 vaccination provides significant protection against mortality.

BackgroundSevere Corona virus disease (COVID-19) is associated with high mortality. Although single centre intensive care units (ICU) have reported clinical characteristics and outcomes, no large scale multicentric study from India has been published. The present retrospective, multi-centre study was aimed to describe the predictors and outcomes of COVID-19 patients requiring ICU admission from COVID-19 Registry of Indian council of Medical Research (ICMR), India.MethodsProspectively collected data from multiple participating institutions was entered in the electronic National Clinical Registry of COVID 19. We enrolled patients aged>18 years with COVID-19 pneumonia requiring ICU admission between March 2020 and August 2021. Exclusion criteria were negative RT PCR, death within 24 hours of ICU admission, or patients with incomplete data in the registry Their demographic characteristics, laboratory variables, ICU severity indices, treatment strategies and outcomes were analysed.ResultsA total of 5865 patients, with mean age 56±15 years, with 3840/5865 (65.4%) men, were enrolled in the ICMR registry.. Overall mortality was 2535/5865 (43.5%). Non-survivors were older than survivors (58.2±15.4 years vs 53.6 ±14.7 years; P=0.001). Non-survivors had multiple comorbidities (n=1951, 52.9%) with hypertension (47.2%) and diabetes (45.6%) being the most common, higher creatinine (1.6 ± P=0.001, high D-dimer (1.56 vs 1.37, P=0.001), higher CT severity index (16.8±5.2 vs 13.5 ±5.47 ) compared to survivors. Non survivors had longer hospital and ICU stay (P=0.001). On multivariate regression analysis, high NLR (HR 1.017, 95% CI 1.005- 1.029, P=0.001), high CRP (HR 1.008, 95% CI 1.006- 1.010, P=0.001), high D dimer ((HR 1.089, 95% CI 1.065- 1.113, P=0.001) were associated with mechanical ventilation while younger age, (HR 0.974, CI 0.965-0.983, p=0.001), high D dimer (HR-1.014, CI 1.001-1.027, P=0.035) and use of prophylactic LMWH (HR 0.647, CI 0.527-0.794, p=0.001) were independently associated with mortality. ConclusionIn this large retrospective study of 5865 critically ill COVID 19 patients admitted to ICU, overall mortality was 2535/5865 (43.5%). Age, high D dimer, CT Severity score and use of prophylactic LMWH were independently associated with mortality.

Mechanistic microstructural models have been developed to capture the effect of isothermal aging on time dependent viscoplastic response of Sn3.0Ag0.5Cu (SAC305) solders. SnAgCu (SAC) solders undergo continuous microstructural coarsening during both storage and service because of their high homologous temperature. The microstructures of these low melting point alloys continuously evolve during service. This results in evolution of creep properties of the joint over time, thereby influencing the long term reliability of microelectronic packages. It is well documented that isothermal aging degrades the creep resistance of SAC solder. SAC305 alloy is aged for (24–1000) h at (25–100)°C (~0.6–0.8 × Tmelt). Cross-sectioning and image processing techniques were used to periodically quantify the effect of isothermal aging on phase coarsening and evolution. The parameters monitored during isothermal aging include size, area fraction, and inter-particle spacing of nanoscale Ag3Sn intermetallic compounds (IMCs) and the volume fraction of micronscale Cu6Sn5 IMCs, as well as the area fraction of pure tin dendrites. Effects of microstructural evolution on secondary creep constitutive response of SAC305 solder joints were then modeled using a mechanistic multiscale creep model. The mechanistic phenomena modeled include: (1) dispersion strengthening by coarsened nanoscale Ag3Sn IMCs in the eutectic phase; and (2) load sharing between pro-eutectic Sn dendrites and the surrounding coarsened eutectic Sn-Ag phase and microscale Cu6Sn5 IMCs. The coarse-grained polycrystalline Sn microstructure in SAC305 solder was not captured in the above model because isothermal aging does not cause any significant change in the initial grain size and orientation of SAC305 solder joints. The above mechanistic model can successfully capture the drop in creep resistance due to the influence of isothermal aging on SAC305 single crystals. Contribution of grain boundary sliding to the creep strain of coarse grained joints has not been modeled in this study.

The lack of statistical homogeneity in functional SnAgCu (SAC) solder joints due to their coarse grained microstructure, in conjunction with the severe anisotropy exhibited by single crystal Sn, renders each joint unique in terms of mechanical behavior. A mechanistic multi-scale modeling framework is proposed in this study to predict the influence of composition and microstructure on the anisotropic transient creep response of single crystal SnAgCu (SAC) solder. Tier I consist of single-crystal eutectic Sn–Ag alloy, with nanoscale Ag 3 Sn particles embedded in a single-crystal Sn matrix. Tier II consists of single crystal SAC solder which is composed of Sn dendrites surrounded by the eutectic Sn–Ag phase of Tier I. The Tier I anisotropic transient creep model is based on dislocation mechanics. The Tier II model uses the results of Tier I as an input and is based on anisotropic composite micro-mechanics. In Tier I, creep deformation is governed by dislocation impediment and recovery at nanoscale Ag 3 Sn particles, with recovery being the rate controlling mechanism. Dislocation climb and dislocation detachment at the Ag 3 Sn particles are proposed to be the competing rate controlling recovery mechanisms. Line tension and mobility of dislocations in dominant slip systems of single crystal Sn are estimated based on the elastic crystal anisotropy of body centered tetragonal (BCT) Sn. The anisotropic transient creep rate of the eutectic Sn–Ag phase of Tier I is then modeled using above inputs and the evolving dislocation density calculated for dominant glide systems during the transient stage of creep. The dominant slip systems are determined based on the dislocation mobility and on the orientation angle between the crystal principal axes and the loading direction. The creep response of the eutectic phase (from Tier 1) is combined with the creep response of Sn lobes at Tier 2, using the anisotropic Mori-Tanaka homogenization theory, to obtain the transient creep response of a SAC305 single crystal along global specimen directions. This model has been calibrated using experimentally obtained transient creep response of a SAC305 single crystal specimen. The above multiscale calibrated model is then used to predict (i) the transient creep response of another SAC305 single crystal specimen and (ii) the effect of orientation (by changing one of the Euler angles) on the transient creep response of SAC305 single crystal. The grain orientation of above two SAC single crystal specimens (with respect to loading direction) were identified with orientation image mapping and then utilized in the model to estimate the resolved shear stress along the dominant slip directions. Parametric studies have also been conducted to predict the effects of the volume fraction, aspect ratio, and orientation of ellipsoidal Sn inclusions on the anisotropic transient creep response of SAC single crystals.

Introduction: Tuberculosis is continuing to be a significant burden in the developing world and tubercular empyema thoracis still remains a common entity with significant morbidity and mortality. Clinical course of tubercular empyema is often accompanied by bronchopleural fistula, concomitant pulmonary tuberculosis and unfavourable outcome. Aim: A prospective study was conducted to assess the clinical presentation of tubercular empyema with special emphasis on evaluating diagnostic role of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) and outcome issues. Materials and Methods: A prospective study was carried out consisting of adult cases of tubercular empyema admitted in the department of Respiratory Medicine in a teaching hospital in eastern India over a period of 18 months. Tubercular empyema cases were analysed on the basis of clinicoradiological features, diagnostic challenges with special interest on role of newer molecular diagnostic test like CBNAAT, management and outcome issues. Results: A total of 40 cases of tubercular empyema were encountered during the study period. Tubercular empyema frequently affected young population (mean age 31.5 years) with a male preponderance (72.5%). Thirty five (87.5%) patients had a duration of illness of more than one month on presentation. There was frequent accompaniment of concomitant pulmonary tuberculosis (60%) and bronchopleural fistula (42.5%). Sputum smear for acid fast bacilli (55%) and CBNAAT (57.5%) were positive in good number of cases. Pleural fluid smear for acid fast bacilli and CBNAAT yield were also very high (72.5% and 92.5% respectively). Pleural fluid CBNAAT had a sensitivity of 92.5% (95% CI: 79.61-98.43) and specificity of 100% (95% CI: 93.51-100) in diagnosis of tubercular empyema. Mean duration of Intercostal tube drainage was 45.6 days and eighteen patients needed decortication. Conclusion: Tubercular empyema is a disease affecting the young population most commonly, has a chronicity in clinical course and is commonly complicated by presence of associated pulmonary tuberculosis, bronchopleural fistula and unfavourable outcome. Pleural fluid and sputum CBNAAT have good yield in diagnosis.

This study investigates the time-dependent viscoplastic response of two relatively new SAC105-X solders—SAC105-05Mn (Sn1.0Ag0.5Cu (SAC105) doped with 0.05 wt.% Mn), and SAC105-55Sb (SAC105 doped with 0.55 wt.% Sb). The results showed that the addition of Mn or Sb increases the creep resistance of SAC105 solder by one to two orders of magnitude at the tested stress levels of 2–20 MPa. The addition of Mn as a fourth alloying element promotes homogeneous distribution of micron-scale Cu6Sn5 intermetallic compounds (IMCs), thereby reducing their interparticle spacing as compared to that of SAC105. On the other hand, addition of Sb does not change the spacing of the Cu6Sn5 particle, but promotes the formation of uniformly sized Sn dendritic lobes, homogeneously distributed in the whole solder joint. Moreover, Sb also forms a solid solution with Sn and strengthens the Sn matrix in SAC105-55Sb itself. The effects of these microstructural changes (obtained using image processing) on the secondary creep constitutive response of SAC105 solder interconnects were then modeled using a mechanistic multiscale creep model. The mechanistic model was able to accurately capture the trends in the secondary creep constitutive response of the alloys and to explain the improvement in creep resistance of SAC105 due to the addition of Mn and Sb.

A 52-year-old female was diagnosed with rheumatoid arthritis and was on methotrexate and prednisolone. She developed fever, cough, hemoptysis, and cavitary lesion on chest skiagram. She was put on antitubercular therapy without any improvement, meanwhile she developed painful right foot drop. Clinicoradiology and C-ANCA study confirmed the diagnosis of granulomatosis with polyangitis (GPA). She was started on cyclophosphamide, corticosteroid, and co-trimoxazole. While her treatment was being continued she showed significant improvement of pulmonary manifestations. About 1 year later, there was reappearance of fever, cough, and radiological opacity with oropharyngeal candidiasis. She became very ill with disseminated intravascular coagulation (DIC)-like features. Immunological markers were negative but bronchoalveolar lavage fluid study showed growth of Aspergillus spp. The patient was promptly put on intravenous voriconazole but unfortunately she succumbed to her illness.

A 28-year-old male presented with fever with right-sided chest pain for 2 weeks. Clinicoradiological picture was suggestive of right-sided pleural effusion. He had history of polytrauma following a road traffic accident and had to undergo emergency laparotomy a month ago. Microscopic and culture examination of the pleural fluid showed neutrophilia, high bilirubin content and presence of gram-negative bacilli. Ultrasound of the abdomen showed the presence of biloma in the liver and right subdiaphragmatic space with fistulous communication into the right thoracic cavity. The patient was managed successfully with complete recovery.

Introduction Anxiety and depression are important but often under-diagnosed co-morbid conditions in patients with Chronic Obstructive Pulmonary Disease (COPD) which may affect the functional capacity of the patients. Aim To find out the proportion of depression and anxiety among stable COPD patients using a validated questionnaire suitable for use in clinic and the factors affecting their reduced functional capability as assessed by six-minute walk test. Materials and methods This was a descriptive cross-sectional study. Seventy five patients diagnosed with stable COPD in outpatient Department of Pulmonary Medicine in a tertiary care hospital, satisfying all inclusion criteria, were included in the study. They were examined clinically, categorized as per Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity assessment guideline and interviewed by designated interviewer using validated questionnaire for depression (Hamilton depression rating scale, HAM-D) and anxiety (State Trait Anxiety Inventory, STAI). The functional exercise capacity of the patient was assessed by six-minute walk test. Statistical analysis was performed using Minitab software (version16.1). Results Among 75 stable COPD patients (68 male, 7 female), majority (32 out of 75) had both depression and anxiety, while only anxiety or depression was present in 9 each. The patients with depression had no significant difference in six-minute walk distance, change in heart rate and respiratory rate (p = 0.4186, 0.219 and 0.41 respectively) as compared to those without depression, but were found to be more dyspnoeic at the end of the test (p= 0.003). There was also no significant difference in walk distance in patients with high STAI score as compared to those with low STAI score (p= 0.276). Conclusion Both anxiety and depression were present in majority of the stable COPD patients. The presence of these co-morbid conditions had no significant effect on the functional status of the patients in the form of reduced six-minute walk distance, though they were more symptomatic than those without these co-morbidities.

BiAgX is one of the potential lead-free substitutes for lead-rich solders for high temperature interconnections, with a melting temperature above 533K after reflow. This study focuses on the mechanical properties of a particular BiAgX solder alloy. These properties are compared to a selected lead-rich solder for reference. The paste for this solder is in the form of mixed solder powder alloys and the reflow process is done in a vacuum oven to prevent oxidation and to minimize voids. The mechanical constitutive tests conducted in this study include: (i) monotonic elastic-plastic stress-strain response at constant strain rates and constant temperatures; and (ii) isothermal, viscoplastic creep strain response at several constant stress levels and different temperatures. The sensitivities of the material viscoplastic constitutive response to temperature and stress level were systematically studied, so that the mechanical performance of this lead-free BiAgX solder can be compared with those of other solders, at similar test conditions. At temperatures above 373K, BiAgX solder paste is found to strain harden more than the selected lead-rich reference solder in monotonic displacement-controlled tests. In isothermal constant-force creep tests, BiAgX is found to be 1-2 orders of magnitude more creep resistant than the selected lead-rich reference solder. The Ramberg-Osgood model is used to represent the elastic-plastic behavior of this BiAgX solder paste and the corresponding model constants are presented in this paper.

A 30-year-old male, carpenter by profession, presented with a history of dry cough and progressive shortness of breath for two months along with right-sided chest pain for one and a half months. The clinico-radiological picture was suggestive of right-sided massive pleural effusion. Computed tomography (CT) scan of the thorax showed a huge mediastinal mass occupying the entire right hemithorax with very small amount of pleural effusion. CT-guided fine needle aspiration cytology and tru-cut biopsy from the mass both revealed small round-cell tumour, possibly small cell carcinoma of the lung. However, on immunohistochemistry tumour cells expressed Mic-2 and it was consistent with a diagnosis of primitive neuroectodermal tumour.

Background: Thoracic empyema is a disease of significant morbidity and mortality, especially in the developing world where tuberculosis remains a common cause. Clinical outcomes in tuberculous empyema are complicated by the presence of concomitant fibrocavitary parenchymal disease and frequent bronchopleural fistulae. We performed a prospective study over a one-and-a-half-year period with the objective of comparing the clinical profiles and outcomes of patients with tuberculous and nontuberculous empyema. Materials and Methods: A prospective study of adult cases of nonsurgical thoracic empyema admitted in a tertiary care hospital in eastern India was performed over a period of 18 months. A comparative analysis of clinical characteristics, treatment modalities, and outcomes of patients with tuberculous and nontuberculous empyema was carried out. Results: Seventy-five cases of empyema were seen during the study period, of which 46 (61.3%) were of nontuberculous etiology while tuberculosis constituted 29 (38.7%) cases. Among the nontuberculous empyema patients, Staphylococcus aureus (11, 23.93%) was the most frequent pathogen isolated, followed by Gram-negative bacilli. Tuberculous empyema was more frequent in younger population compared to nontuberculous empyema (mean age of 32.7 years vs. 46.5 years). Duration of illness and mean duration of chest tube drainage were longer (48.7 vs. 23.2 days) in patients with tuberculous empyema. Also the presence of parenchymal lesions and bronchopleural fistula often requiring surgical drainage procedures was more in tuberculous empyema patients. Conclusion: Tuberculous empyema remains a common cause of empyema thoracis in a country like India. Tuberculous empyema differs from nontuberculous empyema in the age profile, clinical presentation, management issues, and has a significantly poorer outcome.

This study focuses on the mechanical properties of two kinds of solders for high temperature interconnections (melting temperature above 280 °C after reflow). They are both lead-rich solders in wire form: 93.5Pb/5Sn/1.5Ag and 92.5Pb/5Sn/2.5Ag. The mechanical constitutive tests conducted in this study include: (i) monotonic elastic-plastic stress-strain response at constant strain rates and constant temperatures; and (ii) isothermal, viscoplastic creep strain response at several constant stress levels and different temperatures. The sensitivities of the material viscoplastic constitutive response to temperature, loading rate and stress level were systematically studied, so that the mechanical performance of these two solders could be compared with those of other solders, at similar test conditions. Both the Pb-rich solders studied had statistically similar behavior at the tested stress levels and temperatures in creep tests. The Ramberg-Osgood model and the Garofalo model were used to represent the elastic-plastic and creep behavior, respectively, of each solder and the corresponding model constants are presented in the paper.Copyright © 2015 by ASME

A multiscale modeling framework is proposed in this study to capture the influence of the inherent elastic anisotropy of single crystal Sn and the inherent heterogeneous microstructure of a single crystal SnAgCu (SAC) solder grain on the secondary creep response of the grain. The modeling framework treats the SAC microstructure as having several distinct length scales. The smallest length scale (Tier 0) consists of the Sn BCT lattice. The eutectic Sn-Ag micro-constituent, consisting of nanoscale Ag3Sn IMC particles embedded in the single crystal BCT Sn matrix, is termed Tier 1. The single-crystal SAC microstructure, consisting of Sn dendrites and surrounding eutectic Sn-Ag phase, is termed Tier 2. Dislocation recovery mechanisms, such as Orowan climb and detachment from nanoscale Ag3Sn particles, are found to be the rate controlling mechanisms for creep deformation in the eutectic Sn-Ag phase (Tier 1) of a SAC single crystal. The anisotropic secondary creep rate of eutectic Sn-Ag phase (Tier 1), is then modeled using the above inputs and the saturated dislocation density calculated for dominant glide systems during secondary stage of creep. Saturated dislocation density is estimated as the equilibrium saturation between three competing processes: (1) dislocation generation; (2) dislocation impediment caused by back stress from pinning of dislocations at IMCs; and (3) dislocation recovery due to climb/detachment from IMCs. Secondary creep strain rate of eutectic Sn-Ag phase in three most facile slip systems is calculated and compared against the isotropic prediction. At low stress level secondary steady state creep rate along (110)[001] system is predicted to be ten times the creep rate along (100)[0-11] system. However, at high stress level, secondary steady state creep rate along (110)[001] system is predicted to be ten thousand times the creep rate along (100)[0-11] system. The above predictions are in strong agreement with (1–4) orders of magnitude of anisotropy observed in steady state secondary creep response in SAC305 solder joints tested under identical loading conditions in experiments conducted by several authors. The above model is then combined with Eigen-strain methods and average matrix stress concepts to homogenize the load sharing between the Sn dendrites and the surrounding eutectic Ag-Sn matrix. The resulting steady state creep rates are predicted for a few discrete single crystal SAC305 specimens. Very good agreement is observed between the predicted steady state creep rate and the measured creep rates for two SAC305 single crystal specimens.Copyright © 2015 by ASME

This paper provides fundamental mechanistic insights into the significant piece-to-piece variability that many researchers have reported in the creep response of micron-scale high-Sn SAC solder joints in the as-fabricated state, due to coarse-grained microstructure and the anisotropy of Sn. A multiscale mechanistic creep modeling approach is proposed, by combining the individual contributions of the eutectic Sn-Ag phase and the pro-eutectic Sn dendritic phase. The anisotropic transient creep deformation in the eutectic Sn-Ag phase is termed Tier 1 and is modeled with dislocation mechanics. The creep rate of the pure Sn dendritic phase is similarly modeled with dislocation mechanics and combined with that of the eutectic phase, in Tier 2, using an anisotropic load-sharing scheme that utilizes Eshelby methods and Mori-Tanaka homogenization. The creep rate calculations are performed along the dominant slip systems of the Sn grain in a single crystal of SAC solder material, to obtain the transient creep response of a SAC305 single crystal along global loading directions. This model has been calibrated using experimentally obtained transient creep response of a SAC305 single crystal specimen of a particular orientation and then verified against a second SAC305 single crystal specimen of a different orientation. The effect of grain orientation () on the transient creep response of SAC305 single crystal is parametrically demonstrated by varying one of the Euler angles of the grain.

Objective: To evaluate the clinical spectrum of diffuse parenchymal lung diseases (DPLD) encountered in the Indian setting and to compare idiopathic pulmonary fibrosis (IPF) and connective tissue disease associated DPLD (CTD-DPLD), the two commonest aetiologies. Materials and Methods: A prospective study of clinical, imaging and laboratory parameters of patients diagnosed as DPLD and followed up in the Pulmonary Medicine Department of a tertiary-care teaching institution in eastern India was conducted over a period of one year. Results: 92 patients of DPLD were diagnosed in the study period with IPF (n = 35, 38.04%), CTD-DPLD (n = 29, 31.5%), hypersensitivity pneumonitis (n = 10, 10.9%), sarcoidosis (n = 5, 5.4%) and silicosis (n = 5, 5.4%) being the common causes. The CTD-DPLD group had a lower mean age (39.5 ± 1.86 vs 56.9 ± 1.12 years), a longer duration of symptoms (3.5 ± 0.27 vs 2.5 ± 0.26 years), more extra pulmonary manifestations, significantly more base line FVC and 6-minute-walk-distance than the IPF patients. 19 patients of IPF (54%) opted for treatment. All the IPF patients had a significant fall in FVC after six months (mean change -0.203 ± 0.01 litres) compared to the CTD-DPLD group (mean change - 0.05 ± 0.04 litres.) Conclusion: CTD-DPLD patients belong to a younger age group, with longer duration of symptoms, more extrapulmonary features, better physiological parameters and better response to therapy than IPF patients. Larger prospective epidemiological studies and enrolment in clinical trials are necessary for better understanding of the spectrum of diffuse parenchymal lung disorders and their therapeutic options.

Electroplated Ni/Au over Cu is a popular metallization for printed circuit board (PCB) finish as well as for component leads, especially for wire-bondable high frequency packages, where the gold thickness requirement is high (≥ 20 µinches) for wire bonding. This study examines the effect of redeposition of bulk AuSn4 IMC as a function of varying gold content (2–5 nominal weight-%) in the solder joint and copper access (by presence or absence of nickel barrier layer on top of Cu plating) on the cyclic mechanical durability of isothermally aged SAC305 solder joints. The specimens are divided into two batches: i] in the first batch (Type I), both the copper platens to be soldered are electroplated with Au and Ni. Ni barrier layers are used to completely stop the solder from accessing the Cu in the substrate; ii] in the second batch (Type II), one Cu platen is electroplated with Au and Ni barrier layer but the other platen is electroplated only with copper (no nickel layer), to allow access to Cu from the substrate. The first phase to form at the interface of type I specimens after initial reflow is Ni 3 Sn 4 / (Ni,Cu) 3 Sn 4 and type II specimens is (Cu,Ni,Au) 6 Sn 5 / (Cu,Au) 6 Sn 5 . During the subsequent solid-state annealing for 1 month at 120°C, AuSn4 IMCs redeposited on top of initial IMC formed after reflow in type I joints, whereas there is no redeposition observed in type II specimens up to solder joints containing nominal 4 wt-% of Au. Next, the effect of redeposition on cyclic mechanical durability of three different configurations (type I joints with 4 wt-% of Au and type II joints with 3 & 4 wt-% of Au) are characterized at room temperature at a strain rate of approx. 5.5E-2/s using a custom-built thermo-mechanical micro-scale (TMM) test system. Type II joints are found to be more durable than type I joints and within type II specimens, joints containing 3 wt-% of Au are more durable.

Many inventory models have been developed for various deteriorating items with constant demand rate. It is a common experience that, for perishable consumer goods, the age of inventory has a negative impact on the demand due to the loss of consumer confidence on such product. Consumers tend to keep off perishable items which have reached closer to their expiry dates. This paper describes an inventory model in which the demand is considered as a composite function consisting of a constant component, and a variable component which is proportional to the inventory level in the periods when there is a positive inventory buildup. The rate of production is considered finite and the decay rate as exponential. The total cost function is composed of four cost components of all phases of the cycle (backorder replenishment, inventory buildup, inventory depletion and shortage). This cost function is later reduced to a two-variable function using boundary relations to determine iteratively the set of values of the variables that resulted in minimum cost per cycle. The optimum lot-size and order-level were then obtained with relations established previously. Results are demonstrated for an instance of the model.