The Futures Pricing Puzzle

This paper models commodity futures in a rational expectations equilibrium specifically (i) incorporating the conflict of interests between Hedgers (Producers-Consumers) and Speculators and (ii) superimposing constraints to immunize the real sector of the economy from shocks of excessive futures contracting. We extend the framework of Newbery and Stiglitz (1981), Anderson and Danthine (1983) and Britto (1984) to attribute the conflicting and puzzling results in the empirical literature to the presence of multiple equilibria ranked in a pecking order of decreasing pareto-efficiency. Thus, we caution empirical researchers on making inferences on data embedded with moving equilibria, as it can render their analysis of asset pricing mechanism incomprehensible. Finally, we rationalize the imposition of position limits by policy makers to help steer the equilibria to pareto-inferior ones, which make the real sector of the economy more resilient to shocks from the financial sectorContango, Expectations, Normal Backwardations

A Hybrid Technique of Energy Harvesting from Mechanical Vibration and Ambient Illumination

Hybrid energy harvesting is a concept applied for improving the performance of the conventional stand-alone energy harvesters. The thesis presents the analytical formulations and characterization of a hybrid energy harvester that incorporates photovoltaic, piezoelectric, electromagnetic, and electrostatic mechanisms. The initial voltage required for electrostatic mechanism is obtained by the photovoltaic technique. Other mechanisms are embedded into a bimorph piezoelectric cantilever beam having a tip magnet and two sets of comb electrodes on two sides of its substructure. All the segments are interconnected by an electric circuit to generate combined output when subjected to vibration and solar illumination. Results for power output have been obtained at resonance frequency using an optimum load resistance. As the power transduced by each of the mechanisms is combined, more power is generated than those obtained by stand-alone mechanisms. The synergistic feature of this research is further promoted by adding fatigue analysis using finite element method

Thermo-Fluid Characterizations of the Powder-Bed Fusion Additive Manufacturing Processes using Laser and Electron Beam

The powder-bed fusion (PBF) process is a subdivision of Additive Manufacturing (AM) technology where a heat source at a controlled speed selectively fuses regions of a powder-bed material to form three-dimensional (3-D) parts. Two of the most effective PBF processes are selective laser melting (SLM) and electron beam additive manufacturing (EBAM), which can fabricate full-density metallic parts in a layer-by-layer fashion. In this study, thermal behavior and melt-pool dynamics in the PBF process are investigated by developing 3-D multiphysics-based thermo-fluid models for both SLM and EBAM, containing Ti-6Al-4V alloy as a powder-bed material. The laser and electron beams are modeled as conical volumetric heat sources having the Gaussian distribution. The temperature-dependent properties of Ti-6Al-4V and the heat source parameters are incorporated in the models as the user-defined functions. The melt-pool geometry and its thermo-fluid behavior are investigated numerically using computational fluid dynamics, and results for temperature profile, variation in thermo-physical properties, the melt-pool velocity and geometry, and cooling rate are obtained under various heat source specifications. The modeling results for SLM and EBAM under the same irradiation conditions are compared to describe their deterministic features to be considered for industrial applications. The comparison shows that under the same energy density and beam interaction time, the SLM process gives a smaller melt-pool volume but a faster average cooling rate than those in the EBAM process. The thermo-fluid models are validated by comparing the simulation results for the melt-pool geometry with experimental results and resembling the numerical melt-front position with the analytical solution for the classical Stephan problem of melting of a phase-change material

Tests on a subset of regression parameters for factorial experimental data with uncertain higher order interactions

The data generated by many factorial experiments are analyzed by linear regression models. Often the higher order interaction terms of such models are negligible (e.g., R. Mead, The Design of Experiments, Cambridge University Press, Cambridge, 1988, p. 368) although there is uncertainty around it. This kind of nonsample prior information (NSPI) can be presented by null hypotheses (cf. T.A. Bancroft, Ann. Math. Stat. 15 (1944), 190–204), and its uncertainty removed through appropriate statistical test. Depending on the level of the NSPI the unrestricted, restricted, and pretest (PTT) tests are defined. The sampling distributions of test statistics and power functions of the three tests are derived. The graphical and analytical comparisons of powers reveal that the PTT dominates over the other tests

Investigation on white spot syndrome virus (WSSV) in Penaeus monodon brood, nauplii, post larvae and cultured shrimp in Cox’s Bazar, Bangladesh by using nested PCR techniques

Investigations were carried out between April 2014 to June 2016 for detecting white spot syndrome virus (WSV) in tiger shrimp, Penaeus monodon broods, nauplii, post larvae and cultured shrimp by using nested PCR techniques. The presence viral DNA was observed in shrimp culture farms in Cox’s Bazar. Of 558 grow out shrimp samples tested, 239 (42.83%) were found to be positive for WSSV by PCR assay. Of 91 post larvae collected in adjacent river and canal, 41 (45.05%) were infected with WSSV and 70 juvenile shrimps collected, 45 (64%) of the samples were positive for WSSV infection. Selected shrimp hatcheries in the region also showed continual occurrence of WSSV infection and 149 nauplii were tested, 39(26.17%) were positive for WSSV by PCR assay. In hatcheries, 248 nos. P. monodon broods collected, 125(50.40%) were found positive for WSSB. The average WSSV infection in brood shrimps were increased as 32%, 34% and 69% for the years 2014, 2015 and 2016, respectively. P. monodon broods collected from the deep sea zone, WSSV prevalence was 57% in summer (May), falling to 0% during winter month (November). Many of the brooders and juveniles did not exhibit any external symptoms of WSSV infection, however, following PCR amplification with WSSV detection primers clear products were revealed, indicating the presence of latent infection. Thus, effective prevention and control measures are urgently needed to control the spread of the WSSV disease in the shrimp industry. Diagnostic PCR can be applied to screen for carrier brood stock and shrimp larvae used for shrimp culture

Detection of the recurrence of superficial urothelial carcinoma of urinary bladder by combined urine cytology and cystoscopy

The study was aimed to evaluate the accuracy of combined urine cytology and cystoscopy for the detection of the recurrence of superficial urothelial carcinoma of urinary bladder without bladder biopsy. A total 60 patients [males 48, females 12; age range 41-80 years (mean age- 63.15 years)] were included. Urine cytology as well as cystoscopy were done with a targeted biopsy taken from any apparently visible growth in the bladder. The systematic biopsy was taken where there was no growth. Reports of the cytology and cystoscopy were compared with the histopathology reports. It was found that 18 patients were cytology positive (false positive 2) and 42 patients were cytology negative (false negative 10) with sensitivity 61.5% and specificity 94%. During cystoscopy 24 patients were found recurrent growth in the bladder (false positive 3) and 36 patients were negative (false negative 5) with sensitivity 80.7% and specificity 91%. But when combined urine cytology and cystoscopic findings evaluated, the sensitivity and specificity were found 100% and 91% respectively. In conclusion, combined urine cytology and cystoscopy can be used for the detection of recurrence of superficial urothelial carcinoma of urinary bladder

Relation between serum vitamin B12 level and duration of treatment with carbamazepine in epilepsy patients

Vitamin B12 levels in the serum of 58 epileptic patients receiving only carbamazepine for at least 6 months were measured. Same number of epilepsy patients with no history of taking antiepileptic medicine were taken as control. The mean level of vitamin B12 in carbamazepine-treated epileptic patients was 265.5 pg/mL whereas it was 478.3 pg/mL in control. Increased duration of treatment of carbamazepine in epilepsy caused significantly decreased level of serum vitamin B12 (Pearson correlation coefficient, r = -0.9, p<0.0001). In conclusion, serum vitamin B12 level significantly decreased in relation to duration of carbamazepine treatment in epileptic patients

Mechanical, thermal and morphological studies of microfibrillated jute/PLA biocomposites

In the present study, biocomposites based on microfibrillated jute (MFJ) fibre and polylactic acid (PLA) have been prepared by solvent-assisted compression moulding techniques. The MFJ is obtained by a sequence of alkali, chlorite and acid treatments of jute fibre. The biocomposites are fabricated by loading of 10, 20 and 30 wt% of MFJ fibre into the PLA matrix. The effect of MFJ fibre loading on the mechanical, thermal, and morphological properties of the composites is also studied. Among these composites, it is observed that 10 wt% fibre-filled biocomposite shows improved tensile strength andtensile modulus compared to virgin PLA film. Similarly, storage modulus and loss modulus are also found improved for the composites. These composites exhibit higher water absorption capacity and lower thermal stability than virgin PLA. The fibre-matrix adhesion is evaluated by scanning electron microscopy. The results are attributed to the improved interfacial adhesion between MFJ and PLA matrix for 10 wt% fibre-filled biocomposites

Micronutrients and Anaemia

Micronutrient deficiencies and anaemia remain as major health concerns for children in Bangladesh. Among the micronutrient interventions, supplementation with vitamin A to children aged less than five years has been the most successful, especially after distribution of vitamin A was combined with National Immunization Days. Although salt sold in Bangladesh is intended to contain iodine, much of the salt does not contain iodine, and iodine deficiency continues to be common. Anaemia similarly is common among all population groups and has shown no sign of improvement even when iron-supplementation programmes have been attempted. It appears that many other causes contribute to anaemia in addition to iron deficiency. Zinc deficiency is a key micronutrient deficiency and is covered in a separate paper because of its importance among new child-health interventions

Vaginoplasty in vaginal agenesis associated with MRKH syndrome with tabularized peritoneal pull-through

In this paper, a 16 year old girl who was  diagnosed as a case of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, underwent a combined laparotomy-peritoneal approach to create a neovagina by using tubularized peritoneal graft with uneventful postoperative period. Vaginal dilation was maintained with a vaginal mould daily for six months and three to four times weekly thereafter. She was followed-up after 2 and 4 weeks in the first month and three monthly for a duration of six months. On second follow-up, adequate vaginal length of 6-7 cm and width of 2.5-3 cm were achieved with healthy vaginal tissue. Hence, the laparotomy-peritoneal approach of using a peritoneal graft for creations of a neovagina can be  an effective approach  with  minimal  surgical morbidity to  create  a passageway for satisfactory intercourse