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In this study, epoxidized natural rubber (ENR-25) in combination with acrylamide and acrylic acid hydrogels with N,N′-methylenebis(acrylamide) as a chemical cross-linking agent was formulated using a free-radical polymerization technique. Different vol % of sodium hydroxide (NaOH) (5, 10, 15, and 20 vol %) was used to prepare the hydrogel electrolyte and labeled as NR/NaOH5, NR/NaOH10, NR/NaOH15, and NR/NaOH20, respectively. The synthesized hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The ionic conductivity was measured using electrochemical impedance spectroscopy (EIS), and it was found that the NR/NaOH20 hydrogel obtained the highest ionic conductivity of 8.72 mS cm–1with the lowest activation energy of 0.1045 eV. Symmetric supercapacitors were fabricated using NR/NaOH5, NR/NaOH10, NR/NaOH15, and NR/NaOH20 as hydrogel electrolytes and electrochemical studies such as cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) analysis were conducted. The electrochemical performance disclosed that the hydrogel containing the highest amount of NaOH (NR/NaOH20) showed maximum specific capacitances of 49.66 F/g at 5 mV/s and 43.24 F/g at 300 mA/g.

NoMix toilets separate urine and feces at the source and are a promising resource recovery technology. However, design issues hamper the transformation from unattractive to aspirational products. Little effort has been done to design toilets that account for physiological differences, leading to adverse effects on user-friendliness and urine separation efficiency. We used infrared recordings to assess gender-specific urination practices. Based on field data, we developed the Urinator, a simple device that allows simulating male and female urine streams. This supports engineers in developing more user- and gender-friendly and reuse-oriented sanitation technologies.

Deep Neural Networks (DNNs) have been extensively used in many areas including image processing, medical diagnostics and autonomous driving. However, DNNs can exhibit erroneous behaviours that may lead to critical errors, especially when used in safety-critical systems. Inspired by testing techniques for traditional software systems, researchers have proposed neuron coverage criteria, as an analogy to source code coverage, to guide the testing of DNNs. Despite very active research on DNN coverage, several recent studies have questioned the usefulness of such criteria in guiding DNN testing. Further, from a practical standpoint, these criteria are white-box as they require access to the internals or training data of DNNs, which is often not feasible or convenient. Measuring such coverage requires executing DNNs with candidate inputs to guide testing, which is not an option in many practical contexts. In this paper, we investigate diversity metrics as an alternative to white-box coverage criteria. For the previously mentioned reasons, we require such metrics to be black-box and not rely on the execution and outputs of DNNs under test. To this end, we first select and adapt three diversity metrics and study, in a controlled manner, their capacity to measure actual diversity in input sets. We then analyze their statistical association with fault detection using four datasets and five DNNs. We further compare diversity with state-of-the-art white-box coverage criteria. As a mechanism to enable such analysis, we also propose a novel way to estimate fault detection in DNNs. Our experiments show that relying on the diversity of image features embedded in test input sets is a more reliable indicator than coverage criteria to effectively guide DNN testing. Indeed, we found that one of our selected black-box diversity metrics far outperforms existing coverage criteria in terms of fault-revealing capability and computational time. Results also confirm the suspicions that state-of-the-art coverage criteria are not adequate to guide the construction of test input sets to detect as many faults as possible using natural inputs.

Deep Reinforcement Learning (DRL) algorithms have been increasingly employed during the last decade to solve various decision-making problems such as autonomous driving, trading decisions, and robotics. However, these algorithms have faced great challenges when deployed in safety-critical environments since they often exhibit erroneous behaviors that can lead to potentially critical errors. One of the ways to assess the safety of DRL agents is to test them to detect possible faults leading to critical failures during their execution. This raises the question of how we can efficiently test DRL policies to ensure their correctness and adherence to safety requirements. Most existing works on testing DRL agents use adversarial attacks that perturb states or actions of the agent. However, such attacks often lead to unrealistic states of the environment. Furthermore, their main goal is to test the robustness of DRL agents rather than testing the compliance of the agents’ policies with respect to requirements. Due to the huge state space of DRL environments, the high cost of test execution, and the black-box nature of DRL algorithms, exhaustive testing of DRL agents is impossible. In this paper, we propose a Search-based Testing Approach of Reinforcement Learning Agents (STARLA) to test the policy of a DRL agent by effectively searching for failing executions of the agent within a limited testing budget. We rely on machine learning models and a dedicated genetic algorithm to narrow the search toward faulty episodes (i.e., sequences of states and actions produced by the DRL agent). We apply STARLA on Deep-Q-Learning agents trained on two different RL problems widely used as benchmarks and show that STARLA significantly outperforms Random Testing by detecting more faults related to the agent's policy. We also investigate how to extract rules that characterize faulty episodes of the DRL agent using our search results. Such rules can be used to understand the conditions under which the agent fails and thus assess the risks of deploying it.

In an interference channel, IA (interference alignment) yields exquisite channel state data and uncorrelated channel components and gains high DoF (degrees of freedom). This paper proposes the clustering predicated interference alignment with the neural network. Here Adam Optimizer utilized for signal optimization and K-means clustering in which it is utilized in clustering the minuscule cells with the base station and utilizer in the heterogeneous network based on MIMO mmWave. The neural network used here is a convolutional neural network (CNN) which is integrated with the Adam optimizer. The experimental results consider the parameters particularly DoF, spectral efficiency, energy efficiency, signal to interference noise ratio (SINR), and computational complexity. While considering energy efficiency, spectral efficiency, and maximum DoF, simulation results betoken proposed method procures better performance when compared to classical methodology.

Mechanically alloyed Al-5083 powders with different milling times are consolidated by equal channel angular pressing (ECAP) at room temperature (RT), at high temperature (HT), up to two passes in Route A and their mechanical and physical properties are studied in this paper. Microstructural and tensile tests of RT ECAPed samples reveal weaker bonds between the particles which result in poor tensile strength and ductility. Furthermore, the fractograph of RT ECAPed samples shows that the failure is due to particle pull-out as a result of poor metallurgical bonding. Unmilled (0 h) powder is found to have achieved 99.22% of its theoretical density and 45 HRB after the first pass in HT ECAP. However, microstructural studies and tensile tests revealed good metallurgical bonds between the particles. Furthermore, the fractured surface of compacts shows that the failure surface is dominated by the ductile fracture mode. HT ECAP followed by sintering is a suitable method for achieving metallurgical bonding between microparticles.

The fall armyworm (FAW), Spodoptera frugiperda(J.E. Smith), a polyphagous lepidopteran pest that is native to tropical and sub-tropical America has recently invaded the African and Asian countries. Presently, the mitochondrial Cytochrome Oxidase SubunitI (COI)—gene-based molecular characterization of FAW samples from the maize fields of Southern Rajasthan has revealed the occurrence of corn and rice strains there. The occurrence of such S. frugiperdapopulation in the Rajasthan region could be traced to its origin in the Florida-Caribbean region or African region. Further, the Tpigene region analysis showed that the S. frugiperdaforms found in the maize fields are only the corn strains. In the Indian Rajasthan populations of FAW, the Tpi-variant2 category is the highest one and is then followed by the Tpi-variant1 and Tpi-variant3 was unique with C and T at Tpie4192and Tpie4198, respectively. Further research is needed towards the confirmation of these tentatively identified strains of S. frugiperdathat would in turn be helpful for the proper monitoring, host-plant identification and the effective management of such pests.

A high-performance non-noble metal-based electrode is the need of the hour to resolve the challenge of huge energy demand. Energy conversion and storage devices are the two ways to tackle this challenge. In this context, porous and non-noble metal-based electrodes NiCo2O4(NCO), NiCo2O4/NiO (CNO) and NiCo2O4/NiO/rGO (CNOG) are developed as a bifunctional electrode for supercapacitor and methanol fuel cell applications. The binary composite of NiCo2O4with NiO increases the redox sites and enhances its electrochemical activity. The low conductivity and problem of aggregation of transition metal oxides are overcome by developing a hybrid nanocomposite of NiCo2O4/NiO with reduced graphene oxide (rGO). The layer-on-layer morphology of CNOG, and the interfacial interactions among NiCo2O4nanoflakes, NiO nanoparticles and rGO nanosheets increase the specific surface area of the hybrid, which leads to enhanced ion penetration into the active sites. CNOG acts as a potential anode catalyst for methanol oxidation with excellent structural stability. It exhibits a high methanol oxidation current density with low onset potential and faster kinetics. Symmetric supercapacitor CNOG//CNOG delivers specific capacitance of 59.4989 F/g, energy and power density of 6.69 Wh/kg and 698 W/kg respectively at 3 M KOH aqueous electrolyte. The solid-state symmetric supercapacitor (SSSC) using PVA/KOH electrolyte allows broader potential window, thereby outperforming the aqueous electrolyte. The SSSC exhibits specific capacitance of 88.8 F/g, energy and power density 20.84 Wh/kg and 1003 W/kg respectively at the same current density.

Insitu AlB2 particles with Al6061 combination system increase its hardness strength and abatement in density. Al6061-AlB2 insitu composites were created by exothermic response utilizing premixed halide salt KBF4 and Na3AlF6 (for refining aluminium matrix) by liquid strategy with distinct weight rates of AlB2 particles. The as cast matrix combination and the related insitu are exposed to heat treatment at a required temperature of 535°C for one hour followed by quenching in various media like ice, oil, and water. Then the specimens are exposed to an artificial ageing for 175°C for around 10 hours. Microstructural study was directed on as cast and insitu composite to determine the dissemination of AlB2 particles in the base matrix. The reinforced composite showed improvement in hardness when contrasted with as cast alloy. There has also been some improvement in hardness with increasing AlB2 content. The Al6061-AlB2 particulate composites showed critical improvement in hardness when quenched in ice.

Exo-Skeleton is a wearable robotic device which was emerged in later 1960s that has a multitude of applications ranging from weightlifting to wearer’s stability improvement. This paper makes a novel approach in reviewing the various exo-skeleton models that are available at the present. The idea of this paper is to study and compare the models in terms of medical applicability like gait rehabilitation, physiotherapy, human strength augmentation, various control strategies of exo-skeleton, ergonomic study, and need for exo-skeleton system for enhancing the life of humans. Since exo-skeletons are wearable devices, it requires precise controlling of the actuators and repeatability, and accuracy plays a vital role. The paper elucidated with a detailed analysis, reviewed and summarized the core essence of 300 research papers and patents in the field of exo-skeleton with the aforesaid aspects of application and drive system with their control methodologies from 2007 to 2022 and shown a trend with year-wise data from which it is clear that the future of industrial work will become a collaborative activity involving the exo-skeleton system with human labours. Human – robot interaction is vital and must for enabling an integration which can be achieved with the amelioration in the control and actuation techniques for precise control. With the furtherance in the technology the exo-skeletons can be purpose built that can be of rigid or flexible structures with active, passive, or quasi-passive controls based on the user needs. Joint handed operation of Exo-skeleton with the alternative treatment methodologies will yield a plethora of benefits in the near future in comparison with the present conventional treatment modes that could result in reduction of surgeries.

In this paper, nanocomposites of poly(ethylene-co-vinyl acetate) (PEVA)/polyurethane acrylate(PUA)/clay (Cl25A) (PEVA/PUA/Cl25A) are synthesized through a novel in situ method of polymerization. Isophorone-diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA) are mixed with Cloisite 25A (Cl25A) nanofiller, at different percentage of weights. Organo modified montmorillonite clay like Cl25A are used with PEVA/PUA matrix for their liberal compatibility. The main characteristic peaks of the nanocomposite materials are observed in FT-IR spectra. The changes in the intensity and the position validate the strong interaction between clay and polymer. The nanocomposites were investigated by thermogravimetric analysis (TGA) and have exhibited a better thermal stability than the pure pristine PEVA/PUA. Thermal stability in the sample with 5wt.% of PEVA/PUA/Cl25A matrix has improved up to ∼60°C. The morphology of the nanocomposites is studied by scanning electron microscope (SEM) and X-ray diffraction (XRD). The XRD results have confirmed the penetration of clay into the PEVA/PUA matrix, as the d-spacing (2θ=4.79°) increases with the increase in different weight percentage of clay. The dispersion of nanoclay in PEVA/PUA nanocomposites was investigated by scanning electron microscope. The mechanical property associated with tensile strength, elongation at break and Young's modulus has showed a dramatic increase by varying Cloisite 25A, the filler loading, when compared to the pure PEVA/PUA matrix polymer. The barrier properties of the PEVA/PUA/Cl25A nanocomposite membrane with 5wt.% of Cloisite 25A loading has decreased by 51%. The results have suggested that these nanocomposite materials have great potential for applications in packing materials films with superior properties.

This work, Seamless Austenitic 213 tube is welded with Seamless Austenitic 387 tube plate through friction welding of tube to tube plate using an external tool (FWTPET) method in presence of backing block by using clearance fit method. Further, the analysis of microstructural features on the interface of weld exhibit that the FWTPET is able to generate flawless welds. In all nine various work specimen which welded under the various circumstances, the hardness value, tensile strength have taken. In this work, two type of specimen has taken where one kind is the tube which contains no hole and another one is with the hole in the circumference. 806.28 MPa and 746.5 MPa were the optimum strength for the workpiece which is not a having a hole and having the hole on the circumference.

Plasma Arc Welding (PAW) is more tolerant to joint misalignment than Laser Beam Welding (LBW) at a lower cost [1]. The present study deals with the assessment of mechanical and metallurgical properties of butt welded 1.6 mm thick austenitic stainless steel similar (SS304 and SS304) by using plasma arc welding technique. Similar butt-Welded joints were analyzed by using mechanical (Bend test, Erichsen cup test, tensile test) and metallurgical (Optical macroscopic and microscopic images) characterization methods. The bead width and depth of the butt welded 1.6mm thick butt joined SS304 was analyzed by macroscopic and microscopic images [2]. The Erichsen cup test was conducted on the weld specimens. The indentation was made on the weld specimens. In the similar metal joint the depth of indentation is high, which shows that the similar metal joint has better formability. This makes them appropriate for practicing in the aircraft industries (engine parts), automotive sector (engine-parts and assemblies) chemical processing, food processing, turbine buckets, pumps and valve parts [3]. Keywords: SS304, PAW, Butt weld, Erichsen Cup Test, Microstructure

Titanium is a hard metal with good mechanical properties, corrosion resistant and biocompatibility which makes it have a wide range of applications (biomedical and aerospace). Severe plastic deformation (SPD) is employed to produce Ultrafine Grained (UFG) structures. UFG structures have better mechanical properties due to their compaction. Equal Channel Angular Pressing (ECAP) is adapted to produce a UFG structure in Titanium. In this process, titanium sponge powder is filled in the aluminium shell by intermediate tapping to fill the volume of the shell. The shell is then closed with an Al cap and ECAP is done with continuous back pressure at 300°C. The test specimen has undergone four passes in route BC at different back pressure (50, 100 and 150 MPa) where titanium is consolidated without any crack. Titanium showed decreased grain size and porosity with increasing backpressure. In particular, it is seen that the sample ECAPed by 100 MPa backpressure showed a relative density of about 98% with a hardness of 37 HRC. It is seen that ECAP is more economical and the product obtained by the ECAP process has better properties.

Plasma Arc Welding (PAW) is one of the important arc welding processes used in electronics, medical, automotive and aerospace industries due its high accuracy and ability of welding any hard materials which is more tolerant to joint misalignment than Laser Beam Welding (LBW) at a lower cost. Thickness of 1.6mm plates were used to obtain full penetration and a strong joint with a very narrow Heat Affected Zone. The present study deals with the effect of mechanical and corrosion resistance properties of butt welded 1.6 mm thick martensitic stainless steel-similar (SS410 and SS410) joints made by plasma arc welding technique. Similar butt Welded joints were analyzed by using mechanical (Bend test, Erichsen cup test, Tensile test) characterization methods. Their corresponding corrosion resistance properties were also investigated by potentiodynamic polarization corrosion testing technique. The tensile strength was found to be 341 MPa for similar SS410 weld. During tensile test the failure occurred on the base metal on both similar joints Keywords: SS304; SS410; PAW; Butt weld; Erichsen Cup Test; Microstructure.

The study presents the results of the examination on the effect of soaking time on the Microstructure, Grain shape and hardness properties of annealed EN-47 Spring Steel. The EN-47 Spring Steel samples were heated at 860 °C for soaking times of 60, 120, 240, 480 minutes. Optical Microscopy and Rockwell Hardness were carried out to determine the morphology, grain shape and hardness of the material with increasing soaking time. EN-47 Spring Steel samples showed up a decreased value in hardness with the extent of soaking time. Pearlite colonies expand with the increase in soaking time. The linear relationship between the soaking time and other factors were also observed. Keywords: EN-47, Annealing, Microstructure, Rockwell Hardness.

The goal of this research work is to study the role of equal channel angular pressing on consolidation behavior of machined chips of CP Al through ECAP. The chips are collected by orthogonal cutting with cutting edge angle 75° and depth of cut 0.2 mm. The ECAP die with Φ = 90° (channel angle) and Ψ = 20° (corner angle) is used for consolidation of machined chips. The consolidation is done by pre-heating the chips at 200°C upto four passes through processing route BC. The maximum density of 99% and hardness of 94 HV was obtained after 4 ECAP passes. Tribological properties is evaluated by Pin-on-disc dry wear testing for three different loads at a constant sliding speed 750 RPM and distance of 5 kms. Chip consolidated CP Al is inferior in wear resistance with as-received CP Al owed to localised debonding of chips with the sliding disc.

The study presents the results of the investigation on the effect of soaking time on the, Crystalline structure and morphological properties of annealed EN-47 Spring Steel. The EN-47 Spring Steel samples were heated at 860 °C for soaking times of 60, 120, 240, 480 minutes. SEM analysis and XRD analysis were carried out to determine the morphology and crystalline phase of the material with increasing soaking time. Interatomic Distances also decreased with increased in soaking time. The sample with the Soaking time of 480 minutes exhibits a higher Interatomic Distance because of Formation of bigger grains. Through X-ray Diffraction transformation of the crystalline structure were analyzed, in that it is observed that Iron did not undergo any crystalline structure transformation with respect to soaking time whereas other elements changed their structure. Keywords: EN-47, Annealing, XRD, Crystalline Structure, SEM.

This research primarily focuses on improving the strength of Al 5083 alloy by both the ECAP and Cryo ECAP methodology. Equal Channel Angular Pressing (ECAP) is one of the best technologies that enable the direct transformation of conventional macro grained metals into sub-micron, ultra-fine and nano grained materials. Fine grain size increases the strength and the fracture toughness of the material and provides the potential for super plastic deformation at moderate temperatures and at high strain rates. The microstructure evolution in Al 5083, subjected to Room Temperature ECAP and Cryo ECAP were analysed. ECAP was carried out using an optimized die with Channel angle ‘ϕ’ = 90°and corner angle ‘Ψ’ = 20° through processing route A and C up to four passes. The results were thoroughly studied using TEM, SEM, and optical microscopic images. Initially the annealed sample had the grain size of 80 µm with the equi-axed grains. In Room Temperature, the hardness values and the mechanical strength were found to be increased from 88 to 410 HV and 306 to 453 MPa after four passes in route A and in route C the strength increased from 390 to 416 MPa after four ECAP passes. Moreover, in Cryo Condition, the sample was processed up to four ECAP passes at route A and route C. The hardness of 153 HV was obtained after four passes in route C and 164 HV obtained after four passes on route A. Additionally, fracture behaviour using SEM, grain size using TEM and crystallite size by X-ray diffraction studies were analyzed. It was observed that the Cryo ECAP showed marginal improvements in mechanical properties relative to the RT ECAP in case of Al 5083.

Program analysis of automotive software has several unique challenges, including that the code base is ultra large, comprising over a hundred million lines of code running on a single vehicle; the code is structured as a software product line (SPL) for managing a familyof related software products from a common set of artifacts; and the analysis results (despite being numerous and despite being variable) need to be presented to the engineer in a way that is manageable. In previous work, we reported on liftingdeclarative analyses to apply to a software product line, rather than to an individual product variant. This paper reports on milestone results from applying lifted declarative analyses (behaviour alteration, recursion analysis, simplifiable global variable analysis, and two of their variants) to automotive software product lines from General Motors and assessing the scalability of the analyses and the effectiveness of reporting to engineers conditional analysis results (i.e., results conditioned on SPL program variants). We also reflect on some of the lessons learned throughout this project.

Superplasticity is the ability of the material to produce neck free elongations within a material before fracture. For the past three decades superplastic forming has gained a major development in many industries to produce complex shapes. To perform the superplastic forming at elevated temperatures, the material parameters such as strain rate and strain rate sensitivity index has to be determined. These parameters affect the formability in such a way that higher the strain rate during deformation, lesser will be the percentage elongation and which in turn increases the flow stress of the material there by limiting the formability. Similarly, the strain rate sensitivity index is a measure of resistance to neck formation during deformation. Lesser the strain rate sensitivity value, more will be the neck formation thereby limiting the formability. Hence in this work, an experimental setup is designed to perform the uniaxial tensile testing at elevated temperatures to determine the flow stress, percentage elongation, strain rate and strain rate sensitivity. The determination of these parameters will be helpful in executing the forming at certain temperature and pressure to attain maximum formability. Also the SEM photographs of the fractured specimen were analysed to determine at what temperature and strain rate, the cavitation density increases.

This paper presents the dynamic modeling of 210MW Industrial Coal Fired Boiler which is used commonly in thermal power plants. The goal of developing the first principle model is to capture the key dynamical properties of the boiler over a wide operating range. The model describes the complicated dynamics of the various components of Industrial coal fired boiler such as furnace, boiler drum, primary superheater attemperator and secondary superheater. The model is developed based on the physical principles, and is characterized by a few physical parameters. The parameters are determined from the construction data, and a few of them from the field test data. A strong effort has been made to strike a balance between fidelity and simplicity. From the modeling point of view, the boiler is divided into five subsystems and for each subsystem, the first principle models are developed using the mass and energy balance equations. The subsystem models are then integrated to obtain the integrated boiler model. Simulation studies are carried out based on the nominal values of the system variables and the parameters collected from a power plant. The integrated boiler model obtained is tested for its dynamic and steady state characteristics and the results of which are described. The model is validated against the unique plant data and the results are presented. The model describes the behaviour of the system over a wide operating range. A good agreement is found between the simulation and actual parameters of the boiler.

ABSTRACTThe objective of this report was to study the pharmacokinetics of rifampin (RMP), isoniazid (INH), and pyrazinamide (PZA) in HIV-infected children with tuberculosis (TB) treated with a thrice-weekly anti-TB regimen in the government program in India. Seventy-seven HIV-infected children with TB aged 1 to 15 years from six hospitals in India were recruited. During the intensive phase of TB treatment with directly observed administration of the drugs, a complete pharmacokinetic study was performed. Drug concentrations were measured by high-performance liquid chromatography. A multivariable regression analysis was done to explore the factors impacting drug levels and treatment outcomes. The proportions of children with subnormal peak concentrations (Cmax) of RMP, INH, and PZA were 97%, 28%, and 33%, respectively. Children less than 5 years old had a lower median Cmaxand lower exposure (area under the time-concentration curve from 0 to 8 h [AUC0–8]) of INH (Cmax, 2.5 versus 5.1 μg/ml, respectively [P= 0.016]; AUC0–8, 11.1 versus 22.0 μg/ml · h, respectively [P= 0.047[) and PZA (Cmax, 34.1 versus 42.3 μg/ml, respectively [P= 0.055]; AUC0–8, 177.9 versus 221.7 μg/ml · h, respectively [P= 0.05]) than those more than 5 years old. In children with unfavorable versus favorable outcomes, the median Cmaxof RMP (1.0 versus 2.8 μg/ml, respectively; P= 0.002) and PZA (31.9 versus 44.4 μg/ml, respectively; P= 0.045) were significantly lower. Among all factors studied, the PZA Cmaxinfluenced TB treatment outcome (P= 0.011; adjusted odds ratio, 1.094; 95% confidence interval, 1.021 to 1.173). A high proportion of children with HIV and TB had a subnormal RMP Cmax. The PZA Cmaxsignificantly influenced treatment outcome. These findings have important clinical implications and emphasize that drug doses in HIV-infected children with TB have to be optimized.

In the present study AA5083 and AA6061 were welded using friction stir welding process by controlling the various welding parameters viz. rotational speed, welding speed and Tool axial force for two different tool profiles. Aluminum alloys 5083 and 6061 have similar properties and they both are widely used in marine industries and other transportation industries. In this work the effect of various parameters on the mechanical properties viz. tensile strength and impact strength were studied. In this study the Taguchi approach was used as a design of experiment to set optimum parameters. The experiments were done using Taguchi’s L9 orthogonal array. Analysis of variance test was also performed to obtain the effect of the parameters on the weld strength. Both DOE and ANOVA were performed using MINITAB software.

The article discusses a study on the House Crow Corvus splendens bird species that use pylons supporting high-tension powerlines for nesting purposes in Kutch district, Gujarat, India. A total of 71 pylons were surveyed and information on pylon type, number of nests and vegetation were recorded. Although House Crows usually construct nests on large well-branched trees close to human settlements, using pylons in the study may reportedly be due to lack of natural nest sites.

Friction stir processing (FSP) is an emerging surface modification technology for enhancing the sheet metal properties through microstructural refinement at a particular region which might undergo severe plastic deformation. The extruded AZ31B magnesium alloy used in this investigation exhibits very limited ductility accompanied by brittle like behavior at room temperature because of hexagonal packed structure and severe mechanical twinning. Hence, an attempt was made to study the effect of processing parameters such as tool rotational speed and tool traversing speed on tensile properties of friction stir processed AZ31B magnesium alloy. It is found that the friction stir processing of the Magnesium alloy improved the ductility of the material when compared to the base material and also produced an ultrafine equiaxed grain in the processed zone, an ideal condition for the material to exhibit superplasticity.

AbstractThe frequency of Y chromosome microdeletions was studied on idiopathic infertile males with normal karyotype. Genomic DNA was isolated from peripheral blood and PCR analysis was carried out with STS markers – SY 158 and SY 254 to detect the AZFc mutations. Out of 50 infertile males analyzed, four males exhibited AZFc deletions. The SY 158 deletions were observed in three males, viz., azoospermic, severe oligozoospermic and oligozoospermic males. In one azoospermic male SY 254 deletion was observed.

We present a proof of correctness of an algorithm for directly constructing a deterministic finite automaton (DFA) from a regular expression. We do this in a functional framework by introducing a structure called dot annotated regular expression (dare). A dare acts as an implicit representation of a state in a DFA. State transitions in a DFA correspond to dot movements in a dare. We investigate and identify certain algebraic properties of dares which are then used to prove the correctness of the algorithm. The proof is algebraic and presented in the same framework as that of the algorithm itself.

AbstractAdenosine deaminase (ADA) levels show the activity of stimulated T - lymphocytes and its levels are elevated whenever cell mediated immunity is stimulated. Scrum ADA activity, a measure of CMI response was determined in 70 male tobacco factory workers in the age group of 25 -55 years and 70 healthy males not exposed to any hazardous physical or chemical agents for control values. The mean ADA activity was raised in the factory workers. The increase in ADA activity in the workers was found to be statistically significant. The results clearly indicate the cell mediated immunity is impaired in factory workers as a result of exposure to toxic constituents of tobacco.